Changeset 6e1e2d0 for src

Timestamp:

May 1, 2023, 4:19:09 PM (2 years ago)

Author:

caparsons <caparson@…>

Branches:

ADT, ast-experimental, master

Children:

c083c3d

Parents:

a50fdfb (diff), 985b624 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

resolved merge conflicts

Location:

src

Files:

• AST/Attribute.hpp (modified) (1 diff)
• AST/Convert.cpp (modified) (4 diffs)
• AST/Decl.cpp (modified) (2 diffs)
• AST/Decl.hpp (modified) (6 diffs)
• AST/Expr.hpp (modified) (4 diffs)
• AST/Init.hpp (modified) (1 diff)
• AST/Inspect.cpp (modified) (2 diffs)
• AST/Inspect.hpp (modified) (2 diffs)
• AST/Pass.impl.hpp (modified) (1 diff)
• AST/Print.cpp (modified) (1 diff)
• AST/Stmt.hpp (modified) (6 diffs)
• AST/SymbolTable.cpp (modified) (4 diffs)
• AST/SymbolTable.hpp (modified) (1 diff)
• AST/Type.cpp (modified) (2 diffs)
• AST/Type.hpp (modified) (3 diffs)
• Common/CodeLocationTools.cpp (modified) (2 diffs)
• Common/Iterate.hpp (modified) (4 diffs)
• CompilationState.cc (modified) (2 diffs)
• CompilationState.h (modified) (2 diffs)
• Concurrency/KeywordsNew.cpp (modified) (1 diff)
• InitTweak/FixInitNew.cpp (modified) (9 diffs)
• InitTweak/GenInit.cc (modified) (1 diff)
• Parser/DeclarationNode.cc (modified) (7 diffs)
• Parser/DeclarationNode.h (added)
• Parser/ExpressionNode.cc (modified) (3 diffs)
• Parser/ExpressionNode.h (added)
• Parser/InitializerNode.cc (modified) (2 diffs)
• Parser/InitializerNode.h (added)
• Parser/ParseNode.h (modified) (3 diffs)
• Parser/RunParser.cpp (modified) (1 diff)
• Parser/StatementNode.cc (modified) (16 diffs)
• Parser/StatementNode.h (added)
• Parser/TypeData.cc (modified) (2 diffs)
• Parser/TypeData.h (modified) (1 diff)
• Parser/TypedefTable.cc (modified) (2 diffs)
• Parser/TypedefTable.h (modified) (2 diffs)
• Parser/lex.ll (modified) (1 diff)
• Parser/module.mk (modified) (2 diffs)
• Parser/parser.yy (modified) (24 diffs)
• Parser/parserutility.h (modified) (1 diff)
• ResolvExpr/CandidateFinder.cpp (modified) (3 diffs)
• ResolvExpr/CurrentObject.cc (modified) (8 diffs)
• ResolvExpr/CurrentObject.h (modified) (2 diffs)
• ResolvExpr/ExplodedArg.hpp (modified) (1 diff)
• SymTab/Autogen.cc (modified) (4 diffs)
• SymTab/Autogen.h (modified) (8 diffs)
• SymTab/GenImplicitCall.cpp (added)
• SymTab/GenImplicitCall.hpp (added)
• SymTab/module.mk (modified) (1 diff)
• Validate/Autogen.cpp (modified) (3 diffs)
• main.cc (modified) (13 diffs)

src/AST/Attribute.hpp

@@ -27 +27 @@
 class Expr;
 
+/// An entry in an attribute list: `__attribute__(( ... ))`
 class Attribute final : public Node {
 public:

src/AST/Convert.cpp

@@ -559 +559 @@
                 auto stmt = new SuspendStmt();
                 stmt->then   = get<CompoundStmt>().accept1( node->then   );
-                switch(node->type) {
+                switch (node->kind) {
                         case ast::SuspendStmt::None     : stmt->type = SuspendStmt::None     ; break;
                         case ast::SuspendStmt::Coroutine: stmt->type = SuspendStmt::Coroutine; break;
@@ -1695 +1695 @@
                         GET_ACCEPT_V(attributes, Attribute),
                         { old->get_funcSpec().val },
-                        old->type->isVarArgs
+                        (old->type->isVarArgs) ? ast::VariableArgs : ast::FixedArgs
                 };
 
@@ -2001 +2001 @@
                         GET_ACCEPT_1(else_, Stmt),
                         GET_ACCEPT_V(initialization, Stmt),
-                        old->isDoWhile,
+                        (old->isDoWhile) ? ast::DoWhile : ast::While,
                         GET_LABELS_V(old->labels)
                 );
@@ -2143 +2143 @@
         virtual void visit( const SuspendStmt * old ) override final {
                 if ( inCache( old ) ) return;
-                ast::SuspendStmt::Type type;
+                ast::SuspendStmt::Kind type;
                 switch (old->type) {
                         case SuspendStmt::Coroutine: type = ast::SuspendStmt::Coroutine; break;

src/AST/Decl.cpp

@@ -57 +57 @@
         std::vector<ptr<DeclWithType>>&& params, std::vector<ptr<DeclWithType>>&& returns,
         CompoundStmt * stmts, Storage::Classes storage, Linkage::Spec linkage,
-        std::vector<ptr<Attribute>>&& attrs, Function::Specs fs, bool isVarArgs)
+        std::vector<ptr<Attribute>>&& attrs, Function::Specs fs, ArgumentFlag isVarArgs )
 : DeclWithType( loc, name, storage, linkage, std::move(attrs), fs ),
         type_params(std::move(forall)), assertions(),
         params(std::move(params)), returns(std::move(returns)), stmts( stmts ) {
-        FunctionType * ftype = new FunctionType(static_cast<ArgumentFlag>(isVarArgs));
+        FunctionType * ftype = new FunctionType( isVarArgs );
         for (auto & param : this->params) {
                 ftype->params.emplace_back(param->get_type());
@@ -81 +81 @@
         std::vector<ptr<DeclWithType>>&& params, std::vector<ptr<DeclWithType>>&& returns,
         CompoundStmt * stmts, Storage::Classes storage, Linkage::Spec linkage,
-        std::vector<ptr<Attribute>>&& attrs, Function::Specs fs, bool isVarArgs)
+        std::vector<ptr<Attribute>>&& attrs, Function::Specs fs, ArgumentFlag isVarArgs )
 : DeclWithType( location, name, storage, linkage, std::move(attrs), fs ),
                 type_params( std::move( forall) ), assertions( std::move( assertions ) ),
                 params( std::move(params) ), returns( std::move(returns) ),
                 type( nullptr ), stmts( stmts ) {
-        FunctionType * type = new FunctionType( (isVarArgs) ? VariableArgs : FixedArgs );
+        FunctionType * type = new FunctionType( isVarArgs );
         for ( auto & param : this->params ) {
                 type->params.emplace_back( param->get_type() );

src/AST/Decl.hpp

@@ -10 +10 @@
 // Created On       : Thu May 9 10:00:00 2019
 // Last Modified By : Andrew Beach
-// Last Modified On : Thu Nov 24  9:44:00 2022
-// Update Count     : 34
+// Last Modified On : Wed Apr  5 10:42:00 2023
+// Update Count     : 35
 //
 
@@ -122 +122 @@
 };
 
+/// Function variable arguments flag
+enum ArgumentFlag { FixedArgs, VariableArgs };
+
 /// Object declaration `int foo()`
 class FunctionDecl : public DeclWithType {
@@ -144 +147 @@
                 std::vector<ptr<DeclWithType>>&& params, std::vector<ptr<DeclWithType>>&& returns,
                 CompoundStmt * stmts, Storage::Classes storage = {}, Linkage::Spec linkage = Linkage::Cforall,
-                std::vector<ptr<Attribute>>&& attrs = {}, Function::Specs fs = {}, bool isVarArgs = false);
+                std::vector<ptr<Attribute>>&& attrs = {}, Function::Specs fs = {}, ArgumentFlag isVarArgs = FixedArgs );
 
         FunctionDecl( const CodeLocation & location, const std::string & name,
@@ -150 +153 @@
                 std::vector<ptr<DeclWithType>>&& params, std::vector<ptr<DeclWithType>>&& returns,
                 CompoundStmt * stmts, Storage::Classes storage = {}, Linkage::Spec linkage = Linkage::Cforall,
-                std::vector<ptr<Attribute>>&& attrs = {}, Function::Specs fs = {}, bool isVarArgs = false);
+                std::vector<ptr<Attribute>>&& attrs = {}, Function::Specs fs = {}, ArgumentFlag isVarArgs = FixedArgs );
 
         const Type * get_type() const override;
@@ -313 +316 @@
 public:
         bool isTyped; // isTyped indicated if the enum has a declaration like:
-        // enum (type_optional) Name {...} 
+        // enum (type_optional) Name {...}
         ptr<Type> base; // if isTyped == true && base.get() == nullptr, it is a "void" type enum
         enum class EnumHiding { Visible, Hide } hide;
@@ -371 +374 @@
 };
 
+/// Assembly declaration: `asm ... ( "..." : ... )`
 class AsmDecl : public Decl {
 public:

src/AST/Expr.hpp

@@ -254 +254 @@
 };
 
+/// A name qualified by a namespace or type.
 class QualifiedNameExpr final : public Expr {
 public:
@@ -259 +260 @@
         std::string name;
 
-        QualifiedNameExpr( const CodeLocation & loc, const Decl * d, const std::string & n ) 
+        QualifiedNameExpr( const CodeLocation & loc, const Decl * d, const std::string & n )
         : Expr( loc ), type_decl( d ), name( n ) {}
 
@@ -621 +622 @@
 };
 
+/// A name that refers to a generic dimension parameter.
 class DimensionExpr final : public Expr {
 public:
@@ -910 +912 @@
 };
 
-
 }
 

src/AST/Init.hpp

@@ -117 +117 @@
         ptr<Init> init;
 
-        ConstructorInit( 
+        ConstructorInit(
                 const CodeLocation & loc, const Stmt * ctor, const Stmt * dtor, const Init * init )
         : Init( loc, MaybeConstruct ), ctor( ctor ), dtor( dtor ), init( init ) {}

src/AST/Inspect.cpp

@@ -10 +10 @@
 // Created On       : Fri Jun 24 13:16:31 2022
 // Last Modified By : Andrew Beach
-// Last Modified On : Mon Oct  3 11:04:00 2022
-// Update Count     : 3
+// Last Modified On : Fri Apr 14 15:09:00 2023
+// Update Count     : 4
 //
 
@@ -168 +168 @@
 }
 
+bool isUnnamedBitfield( const ast::ObjectDecl * obj ) {
+        return obj && obj->name.empty() && obj->bitfieldWidth;
+}
+
 } // namespace ast

src/AST/Inspect.hpp

@@ -10 +10 @@
 // Created On       : Fri Jun 24 13:16:31 2022
 // Last Modified By : Andrew Beach
-// Last Modified On : Thr Sep 22 13:44:00 2022
-// Update Count     : 2
+// Last Modified On : Fri Apr 14 15:09:00 2023
+// Update Count     : 3
 //
 
@@ -38 +38 @@
 const ApplicationExpr * isIntrinsicCallExpr( const Expr * expr );
 
+/// Returns true if obj's name is the empty string and it has a bitfield width.
+bool isUnnamedBitfield( const ObjectDecl * obj );
+
 }

src/AST/Pass.impl.hpp

@@ -2075 +2075 @@
         if ( __visit_children() ) {
                 maybe_accept( node, &TupleType::types );
-                maybe_accept( node, &TupleType::members );
         }
 

src/AST/Print.cpp

@@ -766 +766 @@
         virtual const ast::Stmt * visit( const ast::SuspendStmt * node ) override final {
                 os << "Suspend Statement";
-                switch (node->type) {
-                        case ast::SuspendStmt::None     : os << " with implicit target"; break;
-                        case ast::SuspendStmt::Generator: os << " for generator"; break;
-                        case ast::SuspendStmt::Coroutine: os << " for coroutine"; break;
+                switch (node->kind) {
+                case ast::SuspendStmt::None     : os << " with implicit target"; break;
+                case ast::SuspendStmt::Generator: os << " for generator"; break;
+                case ast::SuspendStmt::Coroutine: os << " for coroutine"; break;
                 }
                 os << endl;

src/AST/Stmt.hpp

@@ -10 +10 @@
 // Created On       : Wed May  8 13:00:00 2019
 // Last Modified By : Andrew Beach
-// Last Modified On : Wed Apr 20 14:34:00 2022
-// Update Count     : 36
+// Last Modified On : Wed Apr  5 10:34:00 2023
+// Update Count     : 37
 //
 
@@ -205 +205 @@
 };
 
+// A while loop or a do-while loop:
+enum WhileDoKind { While, DoWhile };
+
 // While loop: while (...) ... else ... or do ... while (...) else ...;
 class WhileDoStmt final : public Stmt {
@@ -212 +215 @@
         ptr<Stmt> else_;
         std::vector<ptr<Stmt>> inits;
-        bool isDoWhile;
+        WhileDoKind isDoWhile;
 
         WhileDoStmt( const CodeLocation & loc, const Expr * cond, const Stmt * body,
-                                 const std::vector<ptr<Stmt>> && inits, bool isDoWhile = false, const std::vector<Label> && labels = {} )
+                                 const std::vector<ptr<Stmt>> && inits, WhileDoKind isDoWhile = While, const std::vector<Label> && labels = {} )
                 : Stmt(loc, std::move(labels)), cond(cond), body(body), else_(nullptr), inits(std::move(inits)), isDoWhile(isDoWhile) {}
 
         WhileDoStmt( const CodeLocation & loc, const Expr * cond, const Stmt * body, const Stmt * else_,
-                                 const std::vector<ptr<Stmt>> && inits, bool isDoWhile = false, const std::vector<Label> && labels = {} )
+                                 const std::vector<ptr<Stmt>> && inits, WhileDoKind isDoWhile = While, const std::vector<Label> && labels = {} )
                 : Stmt(loc, std::move(labels)), cond(cond), body(body), else_(else_), inits(std::move(inits)), isDoWhile(isDoWhile) {}
 
@@ -364 +367 @@
   public:
         ptr<CompoundStmt> then;
-        enum Type { None, Coroutine, Generator } type = None;
-
-        SuspendStmt( const CodeLocation & loc, const CompoundStmt * then, Type type, const std::vector<Label> && labels = {} )
-                : Stmt(loc, std::move(labels)), then(then), type(type) {}
+        enum Kind { None, Coroutine, Generator } kind = None;
+
+        SuspendStmt( const CodeLocation & loc, const CompoundStmt * then, Kind kind, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), then(then), kind(kind) {}
 
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
@@ -424 +427 @@
 };
 
+// Clause in a waitfor statement: waitfor (..., ...) ...
 class WaitForClause final : public WhenClause {
   public:
@@ -527 +531 @@
         MUTATE_FRIEND
 };
+
 } // namespace ast
 

src/AST/SymbolTable.cpp

@@ -260 +260 @@
 void SymbolTable::addId( const DeclWithType * decl, const Expr * baseExpr ) {
         // default handling of conflicts is to raise an error
-        addId( decl, OnConflict::error(), baseExpr, decl->isDeleted ? decl : nullptr );
+        addIdCommon( decl, OnConflict::error(), baseExpr, decl->isDeleted ? decl : nullptr );
 }
 
 void SymbolTable::addDeletedId( const DeclWithType * decl, const Decl * deleter ) {
         // default handling of conflicts is to raise an error
-        addId( decl, OnConflict::error(), nullptr, deleter );
+        addIdCommon( decl, OnConflict::error(), nullptr, deleter );
 }
 
@@ -677 +677 @@
 }
 
-void SymbolTable::addId(
-                const DeclWithType * decl, SymbolTable::OnConflict handleConflicts, const Expr * baseExpr,
-                const Decl * deleter ) {
+void SymbolTable::addIdCommon(
+                const DeclWithType * decl, SymbolTable::OnConflict handleConflicts,
+                const Expr * baseExpr, const Decl * deleter ) {
         SpecialFunctionKind kind = getSpecialFunctionKind(decl->name);
         if (kind == NUMBER_OF_KINDS) { // not a special decl
-                addId(decl, decl->name, idTable, handleConflicts, baseExpr, deleter);
+                addIdToTable(decl, decl->name, idTable, handleConflicts, baseExpr, deleter);
         }
         else {
@@ -695 +695 @@
                         assertf(false, "special decl with non-function type");
                 }
-                addId(decl, key, specialFunctionTable[kind], handleConflicts, baseExpr, deleter);
-        }
-}
-
-void SymbolTable::addId(
-                const DeclWithType * decl, const std::string & lookupKey, IdTable::Ptr & table, SymbolTable::OnConflict handleConflicts, const Expr * baseExpr,
-                const Decl * deleter ) {
+                addIdToTable(decl, key, specialFunctionTable[kind], handleConflicts, baseExpr, deleter);
+        }
+}
+
+void SymbolTable::addIdToTable(
+                const DeclWithType * decl, const std::string & lookupKey,
+                IdTable::Ptr & table, SymbolTable::OnConflict handleConflicts,
+                const Expr * baseExpr, const Decl * deleter ) {
         ++*stats().add_calls;
         const std::string &name = decl->name;
@@ -778 +779 @@
 void SymbolTable::addMembers(
                 const AggregateDecl * aggr, const Expr * expr, SymbolTable::OnConflict handleConflicts ) {
-        for ( const Decl * decl : aggr->members ) {
-                if ( auto dwt = dynamic_cast< const DeclWithType * >( decl ) ) {
-                        addId( dwt, handleConflicts, expr );
-                        if ( dwt->name == "" ) {
-                                const Type * t = dwt->get_type()->stripReferences();
-                                if ( auto rty = dynamic_cast<const BaseInstType *>( t ) ) {
-                                        if ( ! dynamic_cast<const StructInstType *>(rty)
-                                                && ! dynamic_cast<const UnionInstType *>(rty) ) continue;
-                                        ResolvExpr::Cost cost = ResolvExpr::Cost::zero;
-                                        ast::ptr<ast::TypeSubstitution> tmp = expr->env;
-                                        expr = mutate_field(expr, &Expr::env, nullptr);
-                                        const Expr * base = ResolvExpr::referenceToRvalueConversion( expr, cost );
-                                        base = mutate_field(base, &Expr::env, tmp);
-
-                                        addMembers(
-                                                rty->aggr(), new MemberExpr{ base->location, dwt, base }, handleConflicts );
-                                }
-                        }
+        for ( const ptr<Decl> & decl : aggr->members ) {
+                auto dwt = decl.as<DeclWithType>();
+                if ( nullptr == dwt ) continue;
+                addIdCommon( dwt, handleConflicts, expr );
+                // Inline through unnamed struct/union members.
+                if ( "" != dwt->name ) continue;
+                const Type * t = dwt->get_type()->stripReferences();
+                if ( auto rty = dynamic_cast<const BaseInstType *>( t ) ) {
+                        if ( ! dynamic_cast<const StructInstType *>(rty)
+                                && ! dynamic_cast<const UnionInstType *>(rty) ) continue;
+                        ResolvExpr::Cost cost = ResolvExpr::Cost::zero;
+                        ast::ptr<ast::TypeSubstitution> tmp = expr->env;
+                        expr = mutate_field(expr, &Expr::env, nullptr);
+                        const Expr * base = ResolvExpr::referenceToRvalueConversion( expr, cost );
+                        base = mutate_field(base, &Expr::env, tmp);
+
+                        addMembers(
+                                rty->aggr(), new MemberExpr{ base->location, dwt, base }, handleConflicts );
                 }
         }

src/AST/SymbolTable.hpp

@@ -192 +192 @@
 
         /// common code for addId, addDeletedId, etc.
-        void addId(
-                const DeclWithType * decl, OnConflict handleConflicts, const Expr * baseExpr = nullptr,
-                const Decl * deleter = nullptr );
+        void addIdCommon(
+                const DeclWithType * decl, OnConflict handleConflicts,
+                const Expr * baseExpr = nullptr, const Decl * deleter = nullptr );
 
         /// common code for addId when special decls are placed into separate tables
-        void addId(
-                const DeclWithType * decl, const std::string & lookupKey, IdTable::Ptr & idTable, OnConflict handleConflicts, 
+        void addIdToTable(
+                const DeclWithType * decl, const std::string & lookupKey,
+                IdTable::Ptr & idTable, OnConflict handleConflicts,
                 const Expr * baseExpr = nullptr, const Decl * deleter = nullptr);
-        
+
         /// adds all of the members of the Aggregate (addWith helper)
         void addMembers( const AggregateDecl * aggr, const Expr * expr, OnConflict handleConflicts );

src/AST/Type.cpp

@@ -10 +10 @@
 // Created On       : Mon May 13 15:00:00 2019
 // Last Modified By : Andrew Beach
-// Last Modified On : Thu Nov 24  9:49:00 2022
-// Update Count     : 6
+// Last Modified On : Thu Apr  6 15:59:00 2023
+// Update Count     : 7
 //
 
@@ -199 +199 @@
 
 TupleType::TupleType( std::vector<ptr<Type>> && ts, CV::Qualifiers q )
-: Type( q ), types( std::move(ts) ), members() {
-        // This constructor is awkward. `TupleType` needs to contain objects so that members can be
-        // named, but members without initializer nodes end up getting constructors, which breaks
-        // things. This happens because the object decls have to be visited so that their types are
-        // kept in sync with the types listed here. Ultimately, the types listed here should perhaps
-        // be eliminated and replaced with a list-view over members. The temporary solution is to
-        // make a `ListInit` with `maybeConstructed = false`, so when the object is visited it is not
-        // constructed. Potential better solutions include:
-        //   a) Separate `TupleType` from its declarations, into `TupleDecl` and `Tuple{Inst?}Type`,
-        //      similar to the aggregate types.
-        //   b) Separate initializer nodes better, e.g. add a `MaybeConstructed` node that is replaced
-        //      by `genInit`, rather than the current boolean flag.
-        members.reserve( types.size() );
-        for ( const Type * ty : types ) {
-                members.emplace_back( new ObjectDecl{
-                        CodeLocation(), "", ty, new ListInit( CodeLocation(), {}, {}, NoConstruct ),
-                        Storage::Classes{}, Linkage::Cforall } );
-        }
-}
+: Type( q ), types( std::move(ts) ) {}
 
 bool isUnboundType(const Type * type) {

src/AST/Type.hpp

@@ -10 +10 @@
 // Created On       : Thu May 9 10:00:00 2019
 // Last Modified By : Andrew Beach
-// Last Modified On : Thu Nov 24  9:47:00 2022
-// Update Count     : 8
+// Last Modified On : Thu Apr  6 15:58:00 2023
+// Update Count     : 9
 //
 
@@ -265 +265 @@
 };
 
-/// Function variable arguments flag
-enum ArgumentFlag { FixedArgs, VariableArgs };
-
 /// Type of a function `[R1, R2](*)(P1, P2, P3)`
 class FunctionType final : public Type {
@@ -460 +457 @@
 public:
         std::vector<ptr<Type>> types;
-        std::vector<ptr<Decl>> members;
 
         TupleType( std::vector<ptr<Type>> && ts, CV::Qualifiers q = {} );

src/Common/CodeLocationTools.cpp

@@ -210 +210 @@
 
 struct LeafKindVisitor : public ast::Visitor {
-        LeafKind kind;
+        LeafKind result;
 
 #define VISIT(node_type, return_type) \
         const ast::return_type * visit( const ast::node_type * ) final { \
-                kind = LeafKind::node_type; \
+                result = LeafKind::node_type; \
                 return nullptr; \
         }
@@ -224 +224 @@
 
 LeafKind get_leaf_kind( ast::Node const * node ) {
-        LeafKindVisitor visitor;
-        node->accept( visitor );
-        return visitor.kind;
+        return ast::Pass<LeafKindVisitor>::read( node );
 }
 

src/Common/Iterate.hpp

@@ -20 +20 @@
 #include <iterator>
 
-// it's nice to actually be able to increment iterators by an arbitrary amount
+// Returns an iterator that is it advanced n times.
 template< class InputIt, class Distance >
 InputIt operator+( InputIt it, Distance n ) {
@@ -50 +50 @@
 
 // -----------------------------------------------------------------------------
+// Helper struct and function to support
+// for ( val_and_index : enumerate( container ) ) {}
+// which iterates through the container and tracks the index as well.
+
 template< typename T >
 struct enumerate_t {
@@ -109 +113 @@
 
 // -----------------------------------------------------------------------------
+// Helper function to transform one iterable container into another.
+
 template< typename OutType, typename Range, typename Functor >
 OutType map_range( const Range& range, Functor&& functor ) {
@@ -206 +212 @@
 // Helper struct and function to support
 // for ( val : lazy_map( container1, f ) ) {}
-// syntax to have a for each that iterates a container, mapping each element by applying f
+// syntax to have a for each that iterates a container,
+// mapping each element by applying f.
+
 template< typename T, typename Func >
 struct lambda_iterate_t {

src/CompilationState.cc

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Mon Ju1 30 10:47:01 2018
-// Last Modified By : Henry Xue
-// Last Modified On : Tue Jul 20 04:27:35 2021
-// Update Count     : 5
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Mon Apr 10 19:12:50 2023
+// Update Count     : 6
 //
 
@@ -27 +27 @@
         expraltp = false,
         genericsp = false,
+        invariant = false,
         libcfap = false,
         nopreludep = false,

src/CompilationState.h

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Mon Ju1 30 10:47:01 2018
-// Last Modified By : Henry Xue
-// Last Modified On : Tue Jul 20 04:27:35 2021
-// Update Count     : 5
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Mon Apr 10 19:12:53 2023
+// Update Count     : 6
 //
 
@@ -26 +26 @@
         expraltp,
         genericsp,
+        invariant,
         libcfap,
         nopreludep,

src/Concurrency/KeywordsNew.cpp

@@ -779 +779 @@
 
 const ast::Stmt * SuspendKeyword::postvisit( const ast::SuspendStmt * stmt ) {
-        switch ( stmt->type ) {
+        switch ( stmt->kind ) {
         case ast::SuspendStmt::None:
                 // Use the context to determain the implicit target.

src/InitTweak/FixInitNew.cpp

@@ -14 +14 @@
 #include <utility>                     // for pair
 
+#include "AST/DeclReplacer.hpp"
+#include "AST/Expr.hpp"
 #include "AST/Inspect.hpp"             // for getFunction, getPointerBase, g...
+#include "AST/Node.hpp"
+#include "AST/Pass.hpp"
+#include "AST/Print.hpp"
+#include "AST/SymbolTable.hpp"
+#include "AST/Type.hpp"
 #include "CodeGen/GenType.h"           // for genPrettyType
 #include "CodeGen/OperatorTable.h"
-#include "Common/CodeLocationTools.hpp"
 #include "Common/PassVisitor.h"        // for PassVisitor, WithStmtsToAdd
 #include "Common/SemanticError.h"      // for SemanticError
@@ -28 +34 @@
 #include "ResolvExpr/Unify.h"          // for typesCompatible
 #include "SymTab/Autogen.h"            // for genImplicitCall
+#include "SymTab/GenImplicitCall.hpp"  // for genImplicitCall
 #include "SymTab/Indexer.h"            // for Indexer
 #include "SymTab/Mangler.h"            // for Mangler
@@ -45 +52 @@
 #include "Validate/FindSpecialDecls.h" // for dtorStmt, dtorStructDestroy
 
-#include "AST/Expr.hpp"
-#include "AST/Node.hpp"
-#include "AST/Pass.hpp"
-#include "AST/Print.hpp"
-#include "AST/SymbolTable.hpp"
-#include "AST/Type.hpp"
-#include "AST/DeclReplacer.hpp"
-
 extern bool ctordtorp; // print all debug
 extern bool ctorp; // print ctor debug
@@ -63 +62 @@
 namespace InitTweak {
 namespace {
+
+        // Shallow copy the pointer list for return.
+        std::vector<ast::ptr<ast::TypeDecl>> getGenericParams( const ast::Type * t ) {
+                if ( auto inst = dynamic_cast<const ast::StructInstType *>( t ) ) {
+                        return inst->base->params;
+                }
+                if ( auto inst = dynamic_cast<const ast::UnionInstType *>( t ) ) {
+                        return inst->base->params;
+                }
+                return {};
+        }
+
+        /// Given type T, generate type of default ctor/dtor, i.e. function type void (*) (T &).
+        ast::FunctionDecl * genDefaultFunc(
+                        const CodeLocation loc,
+                        const std::string fname,
+                        const ast::Type * paramType,
+                        bool maybePolymorphic = true) {
+                std::vector<ast::ptr<ast::TypeDecl>> typeParams;
+                if ( maybePolymorphic ) typeParams = getGenericParams( paramType );
+                auto dstParam = new ast::ObjectDecl( loc,
+                        "_dst",
+                        new ast::ReferenceType( paramType ),
+                        nullptr,
+                        {},
+                        ast::Linkage::Cforall
+                );
+                return new ast::FunctionDecl( loc,
+                        fname,
+                        std::move(typeParams),
+                        {dstParam},
+                        {},
+                        new ast::CompoundStmt(loc),
+                        {},
+                        ast::Linkage::Cforall
+                );
+        }
+
         struct SelfAssignChecker {
                 void previsit( const ast::ApplicationExpr * appExpr );
@@ -121 +158 @@
                 void previsit( const ast::FunctionDecl * ) { visit_children = false; }
 
-          protected:
+        protected:
                 ObjectSet curVars;
         };
@@ -202 +239 @@
 
                 SemanticErrorException errors;
-          private:
+        private:
                 template< typename... Params >
                 void emit( CodeLocation, const Params &... params );
@@ -288 +325 @@
                 static UniqueName dtorNamer( "__cleanup_dtor" );
                 std::string name = dtorNamer.newName();
-                ast::FunctionDecl * dtorFunc = SymTab::genDefaultFunc( loc, name, objDecl->type->stripReferences(), false );
+                ast::FunctionDecl * dtorFunc = genDefaultFunc( loc, name, objDecl->type->stripReferences(), false );
                 stmtsToAdd.push_back( new ast::DeclStmt(loc, dtorFunc ) );
 
@@ -1080 +1117 @@
         void InsertDtors::previsit( const ast::BranchStmt * stmt ) {
                 switch( stmt->kind ) {
-                  case ast::BranchStmt::Continue:
-                  case ast::BranchStmt::Break:
+                case ast::BranchStmt::Continue:
+                case ast::BranchStmt::Break:
                         // could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
                         // always be empty), but it serves as a small sanity check.
-                  case ast::BranchStmt::Goto:
+                case ast::BranchStmt::Goto:
                         handleGoto( stmt );
                         break;
-                  default:
+                default:
                         assert( false );
                 } // switch
@@ -1312 +1349 @@
                 // xxx - functions returning ast::ptr seems wrong...
                 auto res = ResolvExpr::findVoidExpression( untypedExpr, { symtab, transUnit().global } );
-                // Fix CodeLocation (at least until resolver is fixed).
-                auto fix = localFillCodeLocations( untypedExpr->location, res.release() );
-                return strict_dynamic_cast<const ast::Expr *>( fix );
+                return res.release();
         }
 

src/InitTweak/GenInit.cc

@@ -39 +39 @@
 #include "ResolvExpr/Resolver.h"
 #include "SymTab/Autogen.h"            // for genImplicitCall
+#include "SymTab/GenImplicitCall.hpp"  // for genImplicitCall
 #include "SymTab/Mangler.h"            // for Mangler
 #include "SynTree/LinkageSpec.h"       // for isOverridable, C

src/Parser/DeclarationNode.cc

@@ -10 +10 @@
 // Created On       : Sat May 16 12:34:05 2015
 // Last Modified By : Andrew Beach
-// Last Modified On : Tue Apr  4 10:28:00 2023
-// Update Count     : 1392
+// Last Modified On : Thr Apr 20 11:46:00 2023
+// Update Count     : 1393
 //
+
+#include "DeclarationNode.h"
 
 #include <cassert>                 // for assert, assertf, strict_dynamic_cast
@@ -34 +36 @@
 #include "Common/UniqueName.h"     // for UniqueName
 #include "Common/utility.h"        // for maybeClone
-#include "Parser/ParseNode.h"      // for DeclarationNode, ExpressionNode
+#include "Parser/ExpressionNode.h" // for ExpressionNode
+#include "Parser/InitializerNode.h"// for InitializerNode
+#include "Parser/StatementNode.h"  // for StatementNode
 #include "TypeData.h"              // for TypeData, TypeData::Aggregate_t
 #include "TypedefTable.h"          // for TypedefTable
@@ -999 +1003 @@
 }
 
-void buildList( const DeclarationNode * firstNode,
+// If a typedef wraps an anonymous declaration, name the inner declaration
+// so it has a consistent name across translation units.
+static void nameTypedefedDecl(
+                DeclarationNode * innerDecl,
+                const DeclarationNode * outerDecl ) {
+        TypeData * outer = outerDecl->type;
+        assert( outer );
+        // First make sure this is a typedef:
+        if ( outer->kind != TypeData::Symbolic || !outer->symbolic.isTypedef ) {
+                return;
+        }
+        TypeData * inner = innerDecl->type;
+        assert( inner );
+        // Always clear any CVs associated with the aggregate:
+        inner->qualifiers.reset();
+        // Handle anonymous aggregates: typedef struct { int i; } foo
+        if ( inner->kind == TypeData::Aggregate && inner->aggregate.anon ) {
+                delete inner->aggregate.name;
+                inner->aggregate.name = new string( "__anonymous_" + *outerDecl->name );
+                inner->aggregate.anon = false;
+                assert( outer->base );
+                delete outer->base->aggInst.aggregate->aggregate.name;
+                outer->base->aggInst.aggregate->aggregate.name = new string( "__anonymous_" + *outerDecl->name );
+                outer->base->aggInst.aggregate->aggregate.anon = false;
+                outer->base->aggInst.aggregate->qualifiers.reset();
+        // Handle anonymous enumeration: typedef enum { A, B, C } foo
+        } else if ( inner->kind == TypeData::Enum && inner->enumeration.anon ) {
+                delete inner->enumeration.name;
+                inner->enumeration.name = new string( "__anonymous_" + *outerDecl->name );
+                inner->enumeration.anon = false;
+                assert( outer->base );
+                delete outer->base->aggInst.aggregate->enumeration.name;
+                outer->base->aggInst.aggregate->enumeration.name = new string( "__anonymous_" + *outerDecl->name );
+                outer->base->aggInst.aggregate->enumeration.anon = false;
+                // No qualifiers.reset() here.
+        }
+}
+
+// This code handles a special issue with the attribute transparent_union.
+//
+//    typedef union U { int i; } typedef_name __attribute__(( aligned(16) )) __attribute__(( transparent_union ))
+//
+// Here the attribute aligned goes with the typedef_name, so variables declared of this type are
+// aligned.  However, the attribute transparent_union must be moved from the typedef_name to
+// alias union U.  Currently, this is the only know attribute that must be moved from typedef to
+// alias.
+static void moveUnionAttribute( ast::Decl * decl, ast::UnionDecl * unionDecl ) {
+        if ( auto typedefDecl = dynamic_cast<ast::TypedefDecl *>( decl ) ) {
+                // Is the typedef alias a union aggregate?
+                if ( nullptr == unionDecl ) return;
+
+                // If typedef is an alias for a union, then its alias type was hoisted above and remembered.
+                if ( auto unionInstType = typedefDecl->base.as<ast::UnionInstType>() ) {
+                        auto instType = ast::mutate( unionInstType );
+                        // Remove all transparent_union attributes from typedef and move to alias union.
+                        for ( auto attr = instType->attributes.begin() ; attr != instType->attributes.end() ; ) {
+                                assert( *attr );
+                                if ( (*attr)->name == "transparent_union" || (*attr)->name == "__transparent_union__" ) {
+                                        unionDecl->attributes.emplace_back( attr->release() );
+                                        attr = instType->attributes.erase( attr );
+                                } else {
+                                        attr++;
+                                }
+                        }
+                        typedefDecl->base = instType;
+                }
+        }
+}
+
+// Get the non-anonymous name of the instance type of the declaration,
+// if one exists.
+static const std::string * getInstTypeOfName( ast::Decl * decl ) {
+        if ( auto dwt = dynamic_cast<ast::DeclWithType *>( decl ) ) {
+                if ( auto aggr = dynamic_cast<ast::BaseInstType const *>( dwt->get_type() ) ) {
+                        if ( aggr->name.find("anonymous") == std::string::npos ) {
+                                return &aggr->name;
+                        }
+                }
+        }
+        return nullptr;
+}
+
+void buildList( DeclarationNode * firstNode,
                 std::vector<ast::ptr<ast::Decl>> & outputList ) {
         SemanticErrorException errors;
         std::back_insert_iterator<std::vector<ast::ptr<ast::Decl>>> out( outputList );
 
-        for ( const DeclarationNode * cur = firstNode; cur; cur = dynamic_cast< DeclarationNode * >( cur->get_next() ) ) {
+        for ( const DeclarationNode * cur = firstNode ; cur ; cur = strict_next( cur ) ) {
                 try {
-                        bool extracted = false, anon = false;
-                        ast::AggregateDecl * unionDecl = nullptr;
+                        bool extracted_named = false;
+                        ast::UnionDecl * unionDecl = nullptr;
 
                         if ( DeclarationNode * extr = cur->extractAggregate() ) {
-                                // Handle the case where a SUE declaration is contained within an object or type declaration.
-
                                 assert( cur->type );
-                                // Replace anonymous SUE name with typedef name to prevent anonymous naming problems across translation units.
-                                if ( cur->type->kind == TypeData::Symbolic && cur->type->symbolic.isTypedef ) {
-                                        assert( extr->type );
-                                        // Handle anonymous aggregates: typedef struct { int i; } foo
-                                        extr->type->qualifiers.reset();         // clear any CVs associated with the aggregate
-                                        if ( extr->type->kind == TypeData::Aggregate && extr->type->aggregate.anon ) {
-                                                delete extr->type->aggregate.name;
-                                                extr->type->aggregate.name = new string( "__anonymous_" + *cur->name );
-                                                extr->type->aggregate.anon = false;
-                                                assert( cur->type->base );
-                                                if ( cur->type->base ) {
-                                                        delete cur->type->base->aggInst.aggregate->aggregate.name;
-                                                        cur->type->base->aggInst.aggregate->aggregate.name = new string( "__anonymous_" + *cur->name );
-                                                        cur->type->base->aggInst.aggregate->aggregate.anon = false;
-                                                        cur->type->base->aggInst.aggregate->qualifiers.reset();
-                                                } // if
-                                        } // if
-                                        // Handle anonymous enumeration: typedef enum { A, B, C } foo
-                                        if ( extr->type->kind == TypeData::Enum && extr->type->enumeration.anon ) {
-                                                delete extr->type->enumeration.name;
-                                                extr->type->enumeration.name = new string( "__anonymous_" + *cur->name );
-                                                extr->type->enumeration.anon = false;
-                                                assert( cur->type->base );
-                                                if ( cur->type->base ) {
-                                                        delete cur->type->base->aggInst.aggregate->enumeration.name;
-                                                        cur->type->base->aggInst.aggregate->enumeration.name = new string( "__anonymous_" + *cur->name );
-                                                        cur->type->base->aggInst.aggregate->enumeration.anon = false;
-                                                } // if
-                                        } // if
-                                } // if
-
-                                ast::Decl * decl = extr->build();
-                                if ( decl ) {
+                                nameTypedefedDecl( extr, cur );
+
+                                if ( ast::Decl * decl = extr->build() ) {
                                         // Remember the declaration if it is a union aggregate ?
                                         unionDecl = dynamic_cast<ast::UnionDecl *>( decl );
 
-                                        decl->location = cur->location;
                                         *out++ = decl;
 
                                         // need to remember the cases where a declaration contains an anonymous aggregate definition
-                                        extracted = true;
                                         assert( extr->type );
                                         if ( extr->type->kind == TypeData::Aggregate ) {
                                                 // typedef struct { int A } B is the only case?
-                                                anon = extr->type->aggregate.anon;
+                                                extracted_named = !extr->type->aggregate.anon;
                                         } else if ( extr->type->kind == TypeData::Enum ) {
                                                 // typedef enum { A } B is the only case?
-                                                anon = extr->type->enumeration.anon;
+                                                extracted_named = !extr->type->enumeration.anon;
+                                        } else {
+                                                extracted_named = true;
                                         }
                                 } // if
@@ -1066 +1120 @@
                         } // if
 
-                        ast::Decl * decl = cur->build();
-                        if ( decl ) {
-                                if ( auto typedefDecl = dynamic_cast<ast::TypedefDecl *>( decl ) ) {
-                                        if ( unionDecl ) {                                      // is the typedef alias a union aggregate ?
-                                                // This code handles a special issue with the attribute transparent_union.
-                                                //
-                                                //    typedef union U { int i; } typedef_name __attribute__(( aligned(16) )) __attribute__(( transparent_union ))
-                                                //
-                                                // Here the attribute aligned goes with the typedef_name, so variables declared of this type are
-                                                // aligned.  However, the attribute transparent_union must be moved from the typedef_name to
-                                                // alias union U.  Currently, this is the only know attribute that must be moved from typedef to
-                                                // alias.
-
-                                                // If typedef is an alias for a union, then its alias type was hoisted above and remembered.
-                                                if ( auto unionInstType = typedefDecl->base.as<ast::UnionInstType>() ) {
-                                                        auto instType = ast::mutate( unionInstType );
-                                                        // Remove all transparent_union attributes from typedef and move to alias union.
-                                                        for ( auto attr = instType->attributes.begin() ; attr != instType->attributes.end() ; ) { // forward order
-                                                                assert( *attr );
-                                                                if ( (*attr)->name == "transparent_union" || (*attr)->name == "__transparent_union__" ) {
-                                                                        unionDecl->attributes.emplace_back( attr->release() );
-                                                                        attr = instType->attributes.erase( attr );
-                                                                } else {
-                                                                        attr++;
-                                                                } // if
-                                                        } // for
-                                                        typedefDecl->base = instType;
-                                                } // if
-                                        } // if
+                        if ( ast::Decl * decl = cur->build() ) {
+                                moveUnionAttribute( decl, unionDecl );
+
+                                if ( "" == decl->name && !cur->get_inLine() ) {
+                                        // Don't include anonymous declaration for named aggregates,
+                                        // but do include them for anonymous aggregates, e.g.:
+                                        // struct S {
+                                        //   struct T { int x; }; // no anonymous member
+                                        //   struct { int y; };   // anonymous member
+                                        //   struct T;            // anonymous member
+                                        // };
+                                        if ( extracted_named ) {
+                                                continue;
+                                        }
+
+                                        if ( auto name = getInstTypeOfName( decl ) ) {
+                                                // Temporary: warn about anonymous member declarations of named types, since
+                                                // this conflicts with the syntax for the forward declaration of an anonymous type.
+                                                SemanticWarning( cur->location, Warning::AggrForwardDecl, name->c_str() );
+                                        }
                                 } // if
-
-                                // don't include anonymous declaration for named aggregates, but do include them for anonymous aggregates, e.g.:
-                                // struct S {
-                                //   struct T { int x; }; // no anonymous member
-                                //   struct { int y; };   // anonymous member
-                                //   struct T;            // anonymous member
-                                // };
-                                if ( ! (extracted && decl->name == "" && ! anon && ! cur->get_inLine()) ) {
-                                        if ( decl->name == "" ) {
-                                                if ( auto dwt = dynamic_cast<ast::DeclWithType *>( decl ) ) {
-                                                        if ( auto aggr = dynamic_cast<ast::BaseInstType const *>( dwt->get_type() ) ) {
-                                                                if ( aggr->name.find("anonymous") == std::string::npos ) {
-                                                                        if ( ! cur->get_inLine() ) {
-                                                                                // temporary: warn about anonymous member declarations of named types, since
-                                                                                // this conflicts with the syntax for the forward declaration of an anonymous type
-                                                                                SemanticWarning( cur->location, Warning::AggrForwardDecl, aggr->name.c_str() );
-                                                                        } // if
-                                                                } // if
-                                                        } // if
-                                                } // if
-                                        } // if
-                                        decl->location = cur->location;
-                                        *out++ = decl;
-                                } // if
+                                *out++ = decl;
                         } // if
-                } catch( SemanticErrorException & e ) {
+                } catch ( SemanticErrorException & e ) {
                         errors.append( e );
                 } // try
@@ -1132 +1154 @@
 
 // currently only builds assertions, function parameters, and return values
-void buildList( const DeclarationNode * firstNode, std::vector<ast::ptr<ast::DeclWithType>> & outputList ) {
+void buildList( DeclarationNode * firstNode, std::vector<ast::ptr<ast::DeclWithType>> & outputList ) {
         SemanticErrorException errors;
         std::back_insert_iterator<std::vector<ast::ptr<ast::DeclWithType>>> out( outputList );
 
-        for ( const DeclarationNode * cur = firstNode; cur; cur = dynamic_cast< DeclarationNode * >( cur->get_next() ) ) {
+        for ( const DeclarationNode * cur = firstNode; cur; cur = strict_next( cur ) ) {
                 try {
                         ast::Decl * decl = cur->build();
-                        assert( decl );
+                        assertf( decl, "buildList: build for ast::DeclWithType." );
                         if ( ast::DeclWithType * dwt = dynamic_cast<ast::DeclWithType *>( decl ) ) {
                                 dwt->location = cur->location;
@@ -1168 +1190 @@
                                 );
                                 *out++ = obj;
+                        } else {
+                                assertf( false, "buildList: Could not convert to ast::DeclWithType." );
                         } // if
-                } catch( SemanticErrorException & e ) {
+                } catch ( SemanticErrorException & e ) {
                         errors.append( e );
                 } // try
@@ -1183 +1207 @@
         SemanticErrorException errors;
         std::back_insert_iterator<std::vector<ast::ptr<ast::Type>>> out( outputList );
-        const DeclarationNode * cur = firstNode;
-
-        while ( cur ) {
+
+        for ( const DeclarationNode * cur = firstNode ; cur ; cur = strict_next( cur ) ) {
                 try {
                         * out++ = cur->buildType();
-                } catch( SemanticErrorException & e ) {
+                } catch ( SemanticErrorException & e ) {
                         errors.append( e );
                 } // try
-                cur = dynamic_cast< DeclarationNode * >( cur->get_next() );
-        } // while
+        } // for
 
         if ( ! errors.isEmpty() ) {

src/Parser/ExpressionNode.cc

@@ -13 +13 @@
 // Update Count     : 1083
 //
+
+#include "ExpressionNode.h"
 
 #include <cassert>                 // for assert
@@ -25 +27 @@
 #include "Common/SemanticError.h"  // for SemanticError
 #include "Common/utility.h"        // for maybeMoveBuild, maybeBuild, CodeLo...
-#include "ParseNode.h"             // for ExpressionNode, maybeMoveBuildType
+#include "DeclarationNode.h"       // for DeclarationNode
+#include "InitializerNode.h"       // for InitializerNode
 #include "parserutility.h"         // for notZeroExpr
 
@@ -699 +702 @@
 } // build_binary_val
 
-ast::Expr * build_binary_ptr( const CodeLocation & location,
-                OperKinds op,
-                ExpressionNode * expr_node1,
-                ExpressionNode * expr_node2 ) {
-        return build_binary_val( location, op, expr_node1, expr_node2 );
-} // build_binary_ptr
-
 ast::Expr * build_cond( const CodeLocation & location,
                 ExpressionNode * expr_node1,

src/Parser/InitializerNode.cc

@@ -14 +14 @@
 //
 
+#include "InitializerNode.h"
+
 #include <iostream>                // for operator<<, ostream, basic_ostream
 #include <list>                    // for list
 #include <string>                  // for operator<<, string
-
-using namespace std;
 
 #include "AST/Expr.hpp"            // for Expr
@@ -24 +24 @@
 #include "Common/SemanticError.h"  // for SemanticError
 #include "Common/utility.h"        // for maybeBuild
-#include "ParseNode.h"             // for InitializerNode, ExpressionNode
+#include "ExpressionNode.h"        // for ExpressionNode
+#include "DeclarationNode.h"       // for buildList
+
+using namespace std;
 
 static ast::ConstructFlag toConstructFlag( bool maybeConstructed ) {

src/Parser/ParseNode.h

@@ -38 +38 @@
 class DeclarationWithType;
 class Initializer;
+class InitializerNode;
 class ExpressionNode;
 struct StatementNode;
@@ -80 +81 @@
 }; // ParseNode
 
-//##############################################################################
-
-class InitializerNode : public ParseNode {
-  public:
-        InitializerNode( ExpressionNode *, bool aggrp = false, ExpressionNode * des = nullptr );
-        InitializerNode( InitializerNode *, bool aggrp = false, ExpressionNode * des = nullptr );
-        InitializerNode( bool isDelete );
-        ~InitializerNode();
-        virtual InitializerNode * clone() const { assert( false ); return nullptr; }
-
-        ExpressionNode * get_expression() const { return expr; }
-
-        InitializerNode * set_designators( ExpressionNode * des ) { designator = des; return this; }
-        ExpressionNode * get_designators() const { return designator; }
-
-        InitializerNode * set_maybeConstructed( bool value ) { maybeConstructed = value; return this; }
-        bool get_maybeConstructed() const { return maybeConstructed; }
-
-        bool get_isDelete() const { return isDelete; }
-
-        InitializerNode * next_init() const { return kids; }
-
-        void print( std::ostream & os, int indent = 0 ) const;
-        void printOneLine( std::ostream & ) const;
-
-        virtual ast::Init * build() const;
-  private:
-        ExpressionNode * expr;
-        bool aggregate;
-        ExpressionNode * designator;                                            // may be list
-        InitializerNode * kids;
-        bool maybeConstructed;
-        bool isDelete;
-}; // InitializerNode
-
-//##############################################################################
-
-class ExpressionNode final : public ParseNode {
-  public:
-        ExpressionNode( ast::Expr * expr = nullptr ) : expr( expr ) {}
-        virtual ~ExpressionNode() {}
-        virtual ExpressionNode * clone() const override {
-                if ( nullptr == expr ) return nullptr;
-                return static_cast<ExpressionNode*>(
-                        (new ExpressionNode( ast::shallowCopy( expr.get() ) ))->set_next( maybeCopy( get_next() ) ));
-        }
-
-        bool get_extension() const { return extension; }
-        ExpressionNode * set_extension( bool exten ) { extension = exten; return this; }
-
-        virtual void print( std::ostream & os, __attribute__((unused)) int indent = 0 ) const override {
-                os << expr.get();
-        }
-        void printOneLine( __attribute__((unused)) std::ostream & os, __attribute__((unused)) int indent = 0 ) const {}
-
-        template<typename T>
-        bool isExpressionType() const { return nullptr != dynamic_cast<T>(expr.get()); }
-
-        ast::Expr * build() const {
-                ast::Expr * node = const_cast<ExpressionNode *>(this)->expr.release();
-                node->set_extension( this->get_extension() );
-                node->location = this->location;
-                return node;
-        }
-
-        // Public because of lifetime implications (what lifetime implications?)
-        std::unique_ptr<ast::Expr> expr;
-  private:
-        bool extension = false;
-}; // ExpressionNode
-
 // Must harmonize with OperName.
 enum class OperKinds {
@@ -169 +99 @@
 };
 
-// These 4 routines modify the string:
-ast::Expr * build_constantInteger( const CodeLocation &, std::string & );
-ast::Expr * build_constantFloat( const CodeLocation &, std::string & );
-ast::Expr * build_constantChar( const CodeLocation &, std::string & );
-ast::Expr * build_constantStr( const CodeLocation &, std::string & );
-ast::Expr * build_field_name_FLOATING_FRACTIONconstant( const CodeLocation &, const std::string & str );
-ast::Expr * build_field_name_FLOATING_DECIMALconstant( const CodeLocation &, const std::string & str );
-ast::Expr * build_field_name_FLOATINGconstant( const CodeLocation &, const std::string & str );
-ast::Expr * build_field_name_fraction_constants( const CodeLocation &, ast::Expr * fieldName, ExpressionNode * fracts );
-
-ast::NameExpr * build_varref( const CodeLocation &, const std::string * name );
-ast::QualifiedNameExpr * build_qualified_expr( const CodeLocation &, const DeclarationNode * decl_node, const ast::NameExpr * name );
-ast::QualifiedNameExpr * build_qualified_expr( const CodeLocation &, const ast::EnumDecl * decl, const ast::NameExpr * name );
-ast::DimensionExpr * build_dimensionref( const CodeLocation &, const std::string * name );
-
-ast::Expr * build_cast( const CodeLocation &, DeclarationNode * decl_node, ExpressionNode * expr_node );
-ast::Expr * build_keyword_cast( const CodeLocation &, ast::AggregateDecl::Aggregate target, ExpressionNode * expr_node );
-ast::Expr * build_virtual_cast( const CodeLocation &, DeclarationNode * decl_node, ExpressionNode * expr_node );
-ast::Expr * build_fieldSel( const CodeLocation &, ExpressionNode * expr_node, ast::Expr * member );
-ast::Expr * build_pfieldSel( const CodeLocation &, ExpressionNode * expr_node, ast::Expr * member );
-ast::Expr * build_offsetOf( const CodeLocation &, DeclarationNode * decl_node, ast::NameExpr * member );
-ast::Expr * build_and( const CodeLocation &, ExpressionNode * expr_node1, ExpressionNode * expr_node2 );
-ast::Expr * build_and_or( const CodeLocation &, ExpressionNode * expr_node1, ExpressionNode * expr_node2, ast::LogicalFlag flag );
-ast::Expr * build_unary_val( const CodeLocation &, OperKinds op, ExpressionNode * expr_node );
-ast::Expr * build_binary_val( const CodeLocation &, OperKinds op, ExpressionNode * expr_node1, ExpressionNode * expr_node2 );
-ast::Expr * build_binary_ptr( const CodeLocation &, OperKinds op, ExpressionNode * expr_node1, ExpressionNode * expr_node2 );
-ast::Expr * build_cond( const CodeLocation &, ExpressionNode * expr_node1, ExpressionNode * expr_node2, ExpressionNode * expr_node3 );
-ast::Expr * build_tuple( const CodeLocation &, ExpressionNode * expr_node = nullptr );
-ast::Expr * build_func( const CodeLocation &, ExpressionNode * function, ExpressionNode * expr_node );
-ast::Expr * build_compoundLiteral( const CodeLocation &, DeclarationNode * decl_node, InitializerNode * kids );
-
-//##############################################################################
-
-struct TypeData;
-
-struct DeclarationNode : public ParseNode {
-        // These enumerations must harmonize with their names in DeclarationNode.cc.
-        enum BasicType {
-                Void, Bool, Char, Int, Int128,
-                Float, Double, LongDouble, uuFloat80, uuFloat128,
-                uFloat16, uFloat32, uFloat32x, uFloat64, uFloat64x, uFloat128, uFloat128x,
-                NoBasicType
-        };
-        static const char * basicTypeNames[];
-        enum ComplexType { Complex, NoComplexType, Imaginary }; // Imaginary unsupported => parse, but make invisible and print error message
-        static const char * complexTypeNames[];
-        enum Signedness { Signed, Unsigned, NoSignedness };
-        static const char * signednessNames[];
-        enum Length { Short, Long, LongLong, NoLength };
-        static const char * lengthNames[];
-        enum BuiltinType { Valist, AutoType, Zero, One, NoBuiltinType };
-        static const char * builtinTypeNames[];
-
-        static DeclarationNode * newStorageClass( ast::Storage::Classes );
-        static DeclarationNode * newFuncSpecifier( ast::Function::Specs );
-        static DeclarationNode * newTypeQualifier( ast::CV::Qualifiers );
-        static DeclarationNode * newBasicType( BasicType );
-        static DeclarationNode * newComplexType( ComplexType );
-        static DeclarationNode * newSignedNess( Signedness );
-        static DeclarationNode * newLength( Length );
-        static DeclarationNode * newBuiltinType( BuiltinType );
-        static DeclarationNode * newForall( DeclarationNode * );
-        static DeclarationNode * newFromTypedef( const std::string * );
-        static DeclarationNode * newFromGlobalScope();
-        static DeclarationNode * newQualifiedType( DeclarationNode *, DeclarationNode * );
-        static DeclarationNode * newFunction( const std::string * name, DeclarationNode * ret, DeclarationNode * param, StatementNode * body );
-        static DeclarationNode * newAggregate( ast::AggregateDecl::Aggregate kind, const std::string * name, ExpressionNode * actuals, DeclarationNode * fields, bool body );
-        static DeclarationNode * newEnum( const std::string * name, DeclarationNode * constants, bool body, bool typed, DeclarationNode * base = nullptr, EnumHiding hiding = EnumHiding::Visible );
-        static DeclarationNode * newEnumConstant( const std::string * name, ExpressionNode * constant );
-        static DeclarationNode * newEnumValueGeneric( const std::string * name, InitializerNode * init );
-        static DeclarationNode * newEnumInLine( const std::string name );
-        static DeclarationNode * newName( const std::string * );
-        static DeclarationNode * newFromTypeGen( const std::string *, ExpressionNode * params );
-        static DeclarationNode * newTypeParam( ast::TypeDecl::Kind, const std::string * );
-        static DeclarationNode * newTrait( const std::string * name, DeclarationNode * params, DeclarationNode * asserts );
-        static DeclarationNode * newTraitUse( const std::string * name, ExpressionNode * params );
-        static DeclarationNode * newTypeDecl( const std::string * name, DeclarationNode * typeParams );
-        static DeclarationNode * newPointer( DeclarationNode * qualifiers, OperKinds kind );
-        static DeclarationNode * newArray( ExpressionNode * size, DeclarationNode * qualifiers, bool isStatic );
-        static DeclarationNode * newVarArray( DeclarationNode * qualifiers );
-        static DeclarationNode * newBitfield( ExpressionNode * size );
-        static DeclarationNode * newTuple( DeclarationNode * members );
-        static DeclarationNode * newTypeof( ExpressionNode * expr, bool basetypeof = false );
-        static DeclarationNode * newVtableType( DeclarationNode * expr );
-        static DeclarationNode * newAttribute( const std::string *, ExpressionNode * expr = nullptr ); // gcc attributes
-        static DeclarationNode * newDirectiveStmt( StatementNode * stmt ); // gcc external directive statement
-        static DeclarationNode * newAsmStmt( StatementNode * stmt ); // gcc external asm statement
-        static DeclarationNode * newStaticAssert( ExpressionNode * condition, ast::Expr * message );
-
-        DeclarationNode();
-        ~DeclarationNode();
-        DeclarationNode * clone() const override;
-
-        DeclarationNode * addQualifiers( DeclarationNode * );
-        void checkQualifiers( const TypeData *, const TypeData * );
-        void checkSpecifiers( DeclarationNode * );
-        DeclarationNode * copySpecifiers( DeclarationNode * );
-        DeclarationNode * addType( DeclarationNode * );
-        DeclarationNode * addTypedef();
-        DeclarationNode * addEnumBase( DeclarationNode * );
-        DeclarationNode * addAssertions( DeclarationNode * );
-        DeclarationNode * addName( std::string * );
-        DeclarationNode * addAsmName( DeclarationNode * );
-        DeclarationNode * addBitfield( ExpressionNode * size );
-        DeclarationNode * addVarArgs();
-        DeclarationNode * addFunctionBody( StatementNode * body, ExpressionNode * with = nullptr );
-        DeclarationNode * addOldDeclList( DeclarationNode * list );
-        DeclarationNode * setBase( TypeData * newType );
-        DeclarationNode * copyAttribute( DeclarationNode * attr );
-        DeclarationNode * addPointer( DeclarationNode * qualifiers );
-        DeclarationNode * addArray( DeclarationNode * array );
-        DeclarationNode * addNewPointer( DeclarationNode * pointer );
-        DeclarationNode * addNewArray( DeclarationNode * array );
-        DeclarationNode * addParamList( DeclarationNode * list );
-        DeclarationNode * addIdList( DeclarationNode * list ); // old-style functions
-        DeclarationNode * addInitializer( InitializerNode * init );
-        DeclarationNode * addTypeInitializer( DeclarationNode * init );
-
-        DeclarationNode * cloneType( std::string * newName );
-        DeclarationNode * cloneBaseType( DeclarationNode * newdecl );
-
-        DeclarationNode * appendList( DeclarationNode * node ) {
-                return (DeclarationNode *)set_last( node );
-        }
-
-        virtual void print( __attribute__((unused)) std::ostream & os, __attribute__((unused)) int indent = 0 ) const override;
-        virtual void printList( __attribute__((unused)) std::ostream & os, __attribute__((unused)) int indent = 0 ) const override;
-
-        ast::Decl * build() const;
-        ast::Type * buildType() const;
-
-        ast::Linkage::Spec get_linkage() const { return linkage; }
-        DeclarationNode * extractAggregate() const;
-        bool has_enumeratorValue() const { return (bool)enumeratorValue; }
-        ExpressionNode * consume_enumeratorValue() const { return const_cast<DeclarationNode *>(this)->enumeratorValue.release(); }
-
-        bool get_extension() const { return extension; }
-        DeclarationNode * set_extension( bool exten ) { extension = exten; return this; }
-
-        bool get_inLine() const { return inLine; }
-        DeclarationNode * set_inLine( bool inL ) { inLine = inL; return this; }
-
-        DeclarationNode * get_last() { return (DeclarationNode *)ParseNode::get_last(); }
-
-        struct Variable_t {
-//              const std::string * name;
-                ast::TypeDecl::Kind tyClass;
-                DeclarationNode * assertions;
-                DeclarationNode * initializer;
-        };
-        Variable_t variable;
-
-        struct StaticAssert_t {
-                ExpressionNode * condition;
-                ast::Expr * message;
-        };
-        StaticAssert_t assert;
-
-        BuiltinType builtin = NoBuiltinType;
-
-        TypeData * type = nullptr;
-
-        bool inLine = false;
-        bool enumInLine = false;
-        ast::Function::Specs funcSpecs;
-        ast::Storage::Classes storageClasses;
-
-        ExpressionNode * bitfieldWidth = nullptr;
-        std::unique_ptr<ExpressionNode> enumeratorValue;
-        bool hasEllipsis = false;
-        ast::Linkage::Spec linkage;
-        ast::Expr * asmName = nullptr;
-        std::vector<ast::ptr<ast::Attribute>> attributes;
-        InitializerNode * initializer = nullptr;
-        bool extension = false;
-        std::string error;
-        StatementNode * asmStmt = nullptr;
-        StatementNode * directiveStmt = nullptr;
-
-        static UniqueName anonymous;
-}; // DeclarationNode
-
-ast::Type * buildType( TypeData * type );
-
-static inline ast::Type * maybeMoveBuildType( const DeclarationNode * orig ) {
-        ast::Type * ret = orig ? orig->buildType() : nullptr;
-        delete orig;
-        return ret;
-}
-
-//##############################################################################
-
-struct StatementNode final : public ParseNode {
-        StatementNode() :
-                stmt( nullptr ), clause( nullptr ) {}
-        StatementNode( ast::Stmt * stmt ) :
-                stmt( stmt ), clause( nullptr ) {}
-        StatementNode( ast::StmtClause * clause ) :
-                stmt( nullptr ), clause( clause ) {}
-        StatementNode( DeclarationNode * decl );
-        virtual ~StatementNode() {}
-
-        virtual StatementNode * clone() const final { assert( false ); return nullptr; }
-        ast::Stmt * build() const { return const_cast<StatementNode *>(this)->stmt.release(); }
-
-        virtual StatementNode * add_label(
-                        const CodeLocation & location,
-                        const std::string * name,
-                        DeclarationNode * attr = nullptr ) {
-                stmt->labels.emplace_back( location,
-                        *name,
-                        attr ? std::move( attr->attributes )
-                                : std::vector<ast::ptr<ast::Attribute>>{} );
-                delete attr;
-                delete name;
-                return this;
-        }
-
-        virtual StatementNode * append_last_case( StatementNode * );
-
-        virtual void print( std::ostream & os, __attribute__((unused)) int indent = 0 ) const override {
-                os << stmt.get() << std::endl;
-        }
-
-        std::unique_ptr<ast::Stmt> stmt;
-        std::unique_ptr<ast::StmtClause> clause;
-}; // StatementNode
-
-ast::Stmt * build_expr( CodeLocation const &, ExpressionNode * ctl );
-
-struct CondCtl {
-        CondCtl( DeclarationNode * decl, ExpressionNode * condition ) :
-                init( decl ? new StatementNode( decl ) : nullptr ), condition( condition ) {}
-
-        StatementNode * init;
-        ExpressionNode * condition;
-};
-
-struct ForCtrl {
-        ForCtrl( StatementNode * stmt, ExpressionNode * condition, ExpressionNode * change ) :
-                init( stmt ), condition( condition ), change( change ) {}
-
-        StatementNode * init;
-        ExpressionNode * condition;
-        ExpressionNode * change;
-};
-
-ast::Stmt * build_if( const CodeLocation &, CondCtl * ctl, StatementNode * then, StatementNode * else_ );
-ast::Stmt * build_switch( const CodeLocation &, bool isSwitch, ExpressionNode * ctl, StatementNode * stmt );
-ast::CaseClause * build_case( ExpressionNode * ctl );
-ast::CaseClause * build_default( const CodeLocation & );
-ast::Stmt * build_while( const CodeLocation &, CondCtl * ctl, StatementNode * stmt, StatementNode * else_ = nullptr );
-ast::Stmt * build_do_while( const CodeLocation &, ExpressionNode * ctl, StatementNode * stmt, StatementNode * else_ = nullptr );
-ast::Stmt * build_for( const CodeLocation &, ForCtrl * forctl, StatementNode * stmt, StatementNode * else_ = nullptr );
-ast::Stmt * build_branch( const CodeLocation &, ast::BranchStmt::Kind kind );
-ast::Stmt * build_branch( const CodeLocation &, std::string * identifier, ast::BranchStmt::Kind kind );
-ast::Stmt * build_computedgoto( ExpressionNode * ctl );
-ast::Stmt * build_return( const CodeLocation &, ExpressionNode * ctl );
-ast::Stmt * build_throw( const CodeLocation &, ExpressionNode * ctl );
-ast::Stmt * build_resume( const CodeLocation &, ExpressionNode * ctl );
-ast::Stmt * build_resume_at( ExpressionNode * ctl , ExpressionNode * target );
-ast::Stmt * build_try( const CodeLocation &, StatementNode * try_, StatementNode * catch_, StatementNode * finally_ );
-ast::CatchClause * build_catch( const CodeLocation &, ast::ExceptionKind kind, DeclarationNode * decl, ExpressionNode * cond, StatementNode * body );
-ast::FinallyClause * build_finally( const CodeLocation &, StatementNode * stmt );
-ast::Stmt * build_compound( const CodeLocation &, StatementNode * first );
-StatementNode * maybe_build_compound( const CodeLocation &, StatementNode * first );
-ast::Stmt * build_asm( const CodeLocation &, bool voltile, ast::Expr * instruction, ExpressionNode * output = nullptr, ExpressionNode * input = nullptr, ExpressionNode * clobber = nullptr, LabelNode * gotolabels = nullptr );
-ast::Stmt * build_directive( const CodeLocation &, std::string * directive );
-ast::SuspendStmt * build_suspend( const CodeLocation &, StatementNode *, ast::SuspendStmt::Type );
-ast::WaitForStmt * build_waitfor( const CodeLocation &, ast::WaitForStmt * existing, ExpressionNode * when, ExpressionNode * targetExpr, StatementNode * stmt );
-ast::WaitForStmt * build_waitfor_else( const CodeLocation &, ast::WaitForStmt * existing, ExpressionNode * when, StatementNode * stmt );
-ast::WaitForStmt * build_waitfor_timeout( const CodeLocation &, ast::WaitForStmt * existing, ExpressionNode * when, ExpressionNode * timeout, StatementNode * stmt );
-ast::WaitUntilStmt::ClauseNode * build_waituntil_clause( const CodeLocation &, ExpressionNode * when, ExpressionNode * targetExpr, StatementNode * stmt );
-ast::WaitUntilStmt::ClauseNode * build_waituntil_else( const CodeLocation &, ExpressionNode * when, StatementNode * stmt );
-ast::WaitUntilStmt::ClauseNode * build_waituntil_timeout( const CodeLocation &, ExpressionNode * when, ExpressionNode * timeout, StatementNode * stmt );
-ast::WaitUntilStmt * build_waituntil_stmt( const CodeLocation &, ast::WaitUntilStmt::ClauseNode * root );
-ast::Stmt * build_with( const CodeLocation &, ExpressionNode * exprs, StatementNode * stmt );
-ast::Stmt * build_mutex( const CodeLocation &, ExpressionNode * exprs, StatementNode * stmt );
-
-//##############################################################################
-
-template<typename AstType, typename NodeType,
-        template<typename, typename...> class Container, typename... Args>
-void buildList( const NodeType * firstNode,
-                Container<ast::ptr<AstType>, Args...> & output ) {
-        SemanticErrorException errors;
-        std::back_insert_iterator<Container<ast::ptr<AstType>, Args...>> out( output );
-        const NodeType * cur = firstNode;
-
-        while ( cur ) {
-                try {
-                        if ( auto result = dynamic_cast<AstType *>( maybeBuild( cur ) ) ) {
-                                *out++ = result;
-                        } else {
-                                assertf(false, __PRETTY_FUNCTION__ );
-                                SemanticError( cur->location, "type specifier declaration in forall clause is currently unimplemented." );
-                        } // if
-                } catch( SemanticErrorException & e ) {
-                        errors.append( e );
-                } // try
-                const ParseNode * temp = cur->get_next();
-                // Should not return nullptr, then it is non-homogeneous:
-                cur = dynamic_cast<const NodeType *>( temp );
-                if ( !cur && temp ) {
-                        SemanticError( temp->location, "internal error, non-homogeneous nodes founds in buildList processing." );
-                } // if
-        } // while
-        if ( ! errors.isEmpty() ) {
-                throw errors;
-        } // if
-}
-
-// in DeclarationNode.cc
-void buildList( const DeclarationNode * firstNode, std::vector<ast::ptr<ast::Decl>> & outputList );
-void buildList( const DeclarationNode * firstNode, std::vector<ast::ptr<ast::DeclWithType>> & outputList );
-void buildTypeList( const DeclarationNode * firstNode, std::vector<ast::ptr<ast::Type>> & outputList );
-
-template<typename AstType, typename NodeType,
-        template<typename, typename...> class Container, typename... Args>
-void buildMoveList( const NodeType * firstNode,
-                Container<ast::ptr<AstType>, Args...> & output ) {
-        buildList<AstType, NodeType, Container, Args...>( firstNode, output );
-        delete firstNode;
-}
-
-// in ParseNode.cc
 std::ostream & operator<<( std::ostream & out, const ParseNode * node );
 

src/Parser/RunParser.cpp

@@ -20 +20 @@
 #include "CodeTools/TrackLoc.h"             // for fillLocations
 #include "Common/CodeLocationTools.hpp"     // for forceFillCodeLocations
-#include "Parser/ParseNode.h"               // for DeclarationNode, buildList
+#include "Parser/DeclarationNode.h"         // for DeclarationNode, buildList
 #include "Parser/TypedefTable.h"            // for TypedefTable
 

src/Parser/StatementNode.cc

@@ -11 +11 @@
 // Created On       : Sat May 16 14:59:41 2015
 // Last Modified By : Andrew Beach
-// Last Modified On : Tue Apr  4 11:40:00 2023
-// Update Count     : 427
+// Last Modified On : Tue Apr 11 10:16:00 2023
+// Update Count     : 428
 //
+
+#include "StatementNode.h"
 
 #include <cassert>                 // for assert, strict_dynamic_cast, assertf
@@ -23 +25 @@
 #include "Common/SemanticError.h"  // for SemanticError
 #include "Common/utility.h"        // for maybeMoveBuild, maybeBuild
-#include "ParseNode.h"             // for StatementNode, ExpressionNode, bui...
+#include "DeclarationNode.h"       // for DeclarationNode
+#include "ExpressionNode.h"        // for ExpressionNode
 #include "parserutility.h"         // for notZeroExpr
 
@@ -29 +32 @@
 
 using namespace std;
+
+// Some helpers for cases that really want a single node but check for lists.
+static const ast::Stmt * buildMoveSingle( StatementNode * node ) {
+        std::vector<ast::ptr<ast::Stmt>> list;
+        buildMoveList( node, list );
+        assertf( list.size() == 1, "CFA Internal Error: Extra/Missing Nodes" );
+        return list.front().release();
+}
+
+static const ast::Stmt * buildMoveOptional( StatementNode * node ) {
+        std::vector<ast::ptr<ast::Stmt>> list;
+        buildMoveList( node, list );
+        assertf( list.size() <= 1, "CFA Internal Error: Extra Nodes" );
+        return list.empty() ? nullptr : list.front().release();
+}
 
 StatementNode::StatementNode( DeclarationNode * decl ) {
@@ -53 +71 @@
 } // StatementNode::StatementNode
 
-StatementNode * StatementNode::append_last_case( StatementNode * stmt ) {
-        StatementNode * prev = this;
+StatementNode * StatementNode::add_label(
+                const CodeLocation & location,
+                const std::string * name,
+                DeclarationNode * attr ) {
+        stmt->labels.emplace_back( location,
+                *name,
+                attr ? std::move( attr->attributes )
+                        : std::vector<ast::ptr<ast::Attribute>>{} );
+        delete attr;
+        delete name;
+        return this;
+}
+
+ClauseNode * ClauseNode::append_last_case( StatementNode * stmt ) {
+        ClauseNode * prev = this;
         // find end of list and maintain previous pointer
-        for ( StatementNode * curr = prev; curr != nullptr; curr = (StatementNode *)curr->get_next() ) {
-                StatementNode * node = strict_dynamic_cast< StatementNode * >(curr);
-                assert( nullptr == node->stmt.get() );
+        for ( ClauseNode * curr = prev; curr != nullptr; curr = (ClauseNode *)curr->get_next() ) {
+                ClauseNode * node = strict_dynamic_cast< ClauseNode * >(curr);
                 assert( dynamic_cast<ast::CaseClause *>( node->clause.get() ) );
                 prev = curr;
         } // for
+        ClauseNode * node = dynamic_cast< ClauseNode * >(prev);
         // convert from StatementNode list to Statement list
-        StatementNode * node = dynamic_cast< StatementNode * >(prev);
         std::vector<ast::ptr<ast::Stmt>> stmts;
         buildMoveList( stmt, stmts );
@@ -73 +103 @@
         stmts.clear();
         return this;
-} // StatementNode::append_last_case
+} // ClauseNode::append_last_case
 
 ast::Stmt * build_expr( CodeLocation const & location, ExpressionNode * ctl ) {
@@ -97 +127 @@
                 for ( ast::ptr<ast::Stmt> & stmt : inits ) {
                         // build the && of all of the declared variables compared against 0
-                        //auto declStmt = strict_dynamic_cast<ast::DeclStmt *>( stmt );
                         auto declStmt = stmt.strict_as<ast::DeclStmt>();
-                        //ast::DeclWithType * dwt = strict_dynamic_cast<ast::DeclWithType *>( declStmt->decl );
                         auto dwt = declStmt->decl.strict_as<ast::DeclWithType>();
                         ast::Expr * nze = notZeroExpr( new ast::VariableExpr( dwt->location, dwt ) );
@@ -113 +141 @@
         ast::Expr * astcond = build_if_control( ctl, astinit ); // ctl deleted, cond/init set
 
-        std::vector<ast::ptr<ast::Stmt>> aststmt;
-        buildMoveList( then, aststmt );
-        assert( aststmt.size() == 1 );
-        ast::Stmt const * astthen = aststmt.front().release();
-
-        ast::Stmt const * astelse = nullptr;
-        if ( else_ ) {
-                std::vector<ast::ptr<ast::Stmt>> aststmt;
-                buildMoveList( else_, aststmt );
-                assert( aststmt.size() == 1 );
-                astelse = aststmt.front().release();
-        } // if
+        ast::Stmt const * astthen = buildMoveSingle( then );
+        ast::Stmt const * astelse = buildMoveOptional( else_ );
 
         return new ast::IfStmt( location, astcond, astthen, astelse,
@@ -131 +149 @@
 } // build_if
 
-// Temporary work around. Split StmtClause off from StatementNode.
-template<typename clause_t>
-static void buildMoveClauseList( StatementNode * firstNode,
-                std::vector<ast::ptr<clause_t>> & output ) {
-        SemanticErrorException errors;
-        std::back_insert_iterator<std::vector<ast::ptr<clause_t>>>
-                out( output );
-        StatementNode * cur = firstNode;
-
-        while ( cur ) {
-                try {
-                        auto clause = cur->clause.release();
-                        if ( auto result = dynamic_cast<clause_t *>( clause ) ) {
-                                *out++ = result;
-                        } else {
-                                assertf(false, __PRETTY_FUNCTION__ );
-                                SemanticError( cur->location, "type specifier declaration in forall clause is currently unimplemented." );
-                        } // if
-                } catch( SemanticErrorException & e ) {
-                        errors.append( e );
-                } // try
-                ParseNode * temp = cur->get_next();
-                // Should not return nullptr, then it is non-homogeneous:
-                cur = dynamic_cast<StatementNode *>( temp );
-                if ( !cur && temp ) {
-                        SemanticError( temp->location, "internal error, non-homogeneous nodes founds in buildList processing." );
-                } // if
-        } // while
-        if ( ! errors.isEmpty() ) {
-                throw errors;
-        } // if
-        // Usually in the wrapper.
-        delete firstNode;
-}
-
-ast::Stmt * build_switch( const CodeLocation & location, bool isSwitch, ExpressionNode * ctl, StatementNode * stmt ) {
+ast::Stmt * build_switch( const CodeLocation & location, bool isSwitch, ExpressionNode * ctl, ClauseNode * stmt ) {
         std::vector<ast::ptr<ast::CaseClause>> aststmt;
-        buildMoveClauseList( stmt, aststmt );
+        buildMoveList( stmt, aststmt );
         // If it is not a switch it is a choose statement.
         if ( ! isSwitch ) {
@@ -190 +173 @@
 } // build_switch
 
-ast::CaseClause * build_case( ExpressionNode * ctl ) {
+ast::CaseClause * build_case( const CodeLocation & location, ExpressionNode * ctl ) {
         // stmt starts empty and then added to
         auto expr = maybeMoveBuild( ctl );
-        return new ast::CaseClause( expr->location, expr, {} );
+        return new ast::CaseClause( location, expr, {} );
 } // build_case
 
@@ -205 +188 @@
         ast::Expr * astcond = build_if_control( ctl, astinit ); // ctl deleted, cond/init set
 
-        std::vector<ast::ptr<ast::Stmt>> aststmt;                                               // loop body, compound created if empty
-        buildMoveList( stmt, aststmt );
-        assert( aststmt.size() == 1 );
-
-        std::vector<ast::ptr<ast::Stmt>> astelse;                                               // else clause, maybe empty
-        buildMoveList( else_, astelse );
-        assert( astelse.size() <= 1 );
-
         return new ast::WhileDoStmt( location,
                 astcond,
-                aststmt.front(),
-                astelse.empty() ? nullptr : astelse.front().release(),
+                buildMoveSingle( stmt ),
+                buildMoveOptional( else_ ),
                 std::move( astinit ),
-                false
+                ast::While
         );
 } // build_while
 
 ast::Stmt * build_do_while( const CodeLocation & location, ExpressionNode * ctl, StatementNode * stmt, StatementNode * else_ ) {
-        std::vector<ast::ptr<ast::Stmt>> aststmt;                                               // loop body, compound created if empty
-        buildMoveList( stmt, aststmt );
-        assert( aststmt.size() == 1 );                                          // compound created if empty
-
-        std::vector<ast::ptr<ast::Stmt>> astelse;                                               // else clause, maybe empty
-        buildMoveList( else_, astelse );
-        assert( astelse.size() <= 1 );
-
         // do-while cannot have declarations in the contitional, so init is always empty
         return new ast::WhileDoStmt( location,
                 notZeroExpr( maybeMoveBuild( ctl ) ),
-                aststmt.front(),
-                astelse.empty() ? nullptr : astelse.front().release(),
+                buildMoveSingle( stmt ),
+                buildMoveOptional( else_ ),
                 {},
-                true
+                ast::DoWhile
         );
 } // build_do_while
@@ -251 +218 @@
         astincr = maybeMoveBuild( forctl->change );
         delete forctl;
-
-        std::vector<ast::ptr<ast::Stmt>> aststmt;                                               // loop body, compound created if empty
-        buildMoveList( stmt, aststmt );
-        assert( aststmt.size() == 1 );
-
-        std::vector<ast::ptr<ast::Stmt>> astelse;                                               // else clause, maybe empty
-        buildMoveList( else_, astelse );
-        assert( astelse.size() <= 1 );
 
         return new ast::ForStmt( location,
@@ -264 +223 @@
                 astcond,
                 astincr,
-                aststmt.front(),
-                astelse.empty() ? nullptr : astelse.front().release()
+                buildMoveSingle( stmt ),
+                buildMoveOptional( else_ )
         );
 } // build_for
@@ -326 +285 @@
 } // build_resume_at
 
-ast::Stmt * build_try( const CodeLocation & location, StatementNode * try_, StatementNode * catch_, StatementNode * finally_ ) {
+ast::Stmt * build_try( const CodeLocation & location, StatementNode * try_, ClauseNode * catch_, ClauseNode * finally_ ) {
         std::vector<ast::ptr<ast::CatchClause>> aststmt;
-        buildMoveClauseList( catch_, aststmt );
+        buildMoveList( catch_, aststmt );
         ast::CompoundStmt * tryBlock = strict_dynamic_cast<ast::CompoundStmt *>( maybeMoveBuild( try_ ) );
         ast::FinallyClause * finallyBlock = nullptr;
@@ -342 +301 @@
 
 ast::CatchClause * build_catch( const CodeLocation & location, ast::ExceptionKind kind, DeclarationNode * decl, ExpressionNode * cond, StatementNode * body ) {
-        std::vector<ast::ptr<ast::Stmt>> aststmt;
-        buildMoveList( body, aststmt );
-        assert( aststmt.size() == 1 );
         return new ast::CatchClause( location,
                 kind,
                 maybeMoveBuild( decl ),
                 maybeMoveBuild( cond ),
-                aststmt.front().release()
+                buildMoveSingle( body )
         );
 } // build_catch
 
 ast::FinallyClause * build_finally( const CodeLocation & location, StatementNode * stmt ) {
-        std::vector<ast::ptr<ast::Stmt>> aststmt;
-        buildMoveList( stmt, aststmt );
-        assert( aststmt.size() == 1 );
         return new ast::FinallyClause( location,
-                aststmt.front().strict_as<ast::CompoundStmt>()
+                strict_dynamic_cast<const ast::CompoundStmt *>(
+                        buildMoveSingle( stmt )
+                )
         );
 } // build_finally
 
-ast::SuspendStmt * build_suspend( const CodeLocation & location, StatementNode * then, ast::SuspendStmt::Type type ) {
-        std::vector<ast::ptr<ast::Stmt>> stmts;
-        buildMoveList( then, stmts );
-        ast::CompoundStmt const * then2 = nullptr;
-        if(!stmts.empty()) {
-                assert( stmts.size() == 1 );
-                then2 = stmts.front().strict_as<ast::CompoundStmt>();
-        }
-        auto node = new ast::SuspendStmt( location, then2, ast::SuspendStmt::None );
-        node->type = type;
-        return node;
+ast::SuspendStmt * build_suspend( const CodeLocation & location, StatementNode * then, ast::SuspendStmt::Kind kind ) {
+        return new ast::SuspendStmt( location,
+                strict_dynamic_cast<const ast::CompoundStmt *, nullptr>(
+                        buildMoveOptional( then )
+                ),
+                kind
+        );
 } // build_suspend
 
@@ -525 +476 @@
 
 // Question
-ast::Stmt * build_asm( const CodeLocation & location, bool voltile, ast::Expr * instruction, ExpressionNode * output, ExpressionNode * input, ExpressionNode * clobber, LabelNode * gotolabels ) {
+ast::Stmt * build_asm( const CodeLocation & location, bool is_volatile, ExpressionNode * instruction, ExpressionNode * output, ExpressionNode * input, ExpressionNode * clobber, LabelNode * gotolabels ) {
         std::vector<ast::ptr<ast::Expr>> out, in;
         std::vector<ast::ptr<ast::ConstantExpr>> clob;
@@ -533 +484 @@
         buildMoveList( clobber, clob );
         return new ast::AsmStmt( location,
-                voltile,
-                instruction,
+                is_volatile,
+                maybeMoveBuild( instruction ),
                 std::move( out ),
                 std::move( in ),

src/Parser/TypeData.cc

@@ -24 +24 @@
 #include "Common/SemanticError.h"  // for SemanticError
 #include "Common/utility.h"        // for splice, spliceBegin
-#include "Parser/parserutility.h"  // for maybeCopy, maybeBuild, maybeMoveB...
-#include "Parser/ParseNode.h"      // for DeclarationNode, ExpressionNode
+#include "Parser/ExpressionNode.h" // for ExpressionNode
+#include "Parser/StatementNode.h"  // for StatementNode
 
 class Attribute;
@@ -1397 +1397 @@
                 std::move( attributes ),
                 funcSpec,
-                isVarArgs
+                (isVarArgs) ? ast::VariableArgs : ast::FixedArgs
         );
         buildList( td->function.withExprs, decl->withExprs );

src/Parser/TypeData.h

@@ -16 +16 @@
 #pragma once
 
-#include <iosfwd>                                                                               // for ostream
-#include <list>                                                                                 // for list
-#include <string>                                                                               // for string
+#include <iosfwd>                                   // for ostream
+#include <list>                                     // for list
+#include <string>                                   // for string
 
-#include "AST/Type.hpp"                                                                 // for Type
-#include "ParseNode.h"                                                                  // for DeclarationNode, DeclarationNode::Ag...
+#include "AST/Type.hpp"                             // for Type
+#include "DeclarationNode.h"                        // for DeclarationNode
 
 struct TypeData {

src/Parser/TypedefTable.cc

@@ -16 +16 @@
 
 #include "TypedefTable.h"
-#include <cassert>                                                                              // for assert
-#include <iostream>
+
+#include <cassert>                                // for assert
+#include <string>                                 // for string
+#include <iostream>                               // for iostream
+
+#include "ExpressionNode.h"                       // for LabelNode
+#include "ParserTypes.h"                          // for Token
+#include "StatementNode.h"                        // for CondCtl, ForCtrl
+// This (generated) header must come late as it is missing includes.
+#include "parser.hh"              // for IDENTIFIER, TYPEDEFname, TYPEGENname
+
 using namespace std;
 
 #if 0
 #define debugPrint( code ) code
+
+static const char *kindName( int kind ) {
+        switch ( kind ) {
+        case IDENTIFIER: return "identifier";
+        case TYPEDIMname: return "typedim";
+        case TYPEDEFname: return "typedef";
+        case TYPEGENname: return "typegen";
+        default:
+                cerr << "Error: cfa-cpp internal error, invalid kind of identifier" << endl;
+                abort();
+        } // switch
+} // kindName
 #else
 #define debugPrint( code )
 #endif
-
-using namespace std;                                                                    // string, iostream
-
-debugPrint(
-        static const char *kindName( int kind ) {
-                switch ( kind ) {
-                case IDENTIFIER: return "identifier";
-                case TYPEDIMname: return "typedim";
-                case TYPEDEFname: return "typedef";
-                case TYPEGENname: return "typegen";
-                default:
-                        cerr << "Error: cfa-cpp internal error, invalid kind of identifier" << endl;
-                        abort();
-                } // switch
-        } // kindName
-);
 
 TypedefTable::~TypedefTable() {
@@ -78 +83 @@
                 typedefTable.addToEnclosingScope( name, kind, "MTD" );
         } // if
+} // TypedefTable::makeTypedef
+
+void TypedefTable::makeTypedef( const string & name ) {
+        return makeTypedef( name, TYPEDEFname );
 } // TypedefTable::makeTypedef
 

src/Parser/TypedefTable.h

@@ -19 +19 @@
 
 #include "Common/ScopedMap.h"                                                   // for ScopedMap
-#include "ParserTypes.h"
-#include "parser.hh"                                                                    // for IDENTIFIER, TYPEDEFname, TYPEGENname
 
 class TypedefTable {
         struct Note { size_t level; bool forall; };
         typedef ScopedMap< std::string, int, Note > KindTable;
-        KindTable kindTable;    
+        KindTable kindTable;
         unsigned int level = 0;
   public:
@@ -33 +31 @@
         bool existsCurr( const std::string & identifier ) const;
         int isKind( const std::string & identifier ) const;
-        void makeTypedef( const std::string & name, int kind = TYPEDEFname );
+        void makeTypedef( const std::string & name, int kind );
+        void makeTypedef( const std::string & name );
         void addToScope( const std::string & identifier, int kind, const char * );
         void addToEnclosingScope( const std::string & identifier, int kind, const char * );

src/Parser/lex.ll

@@ -44 +44 @@
 
 #include "config.h"                                                                             // configure info
+#include "DeclarationNode.h"                            // for DeclarationNode
+#include "ExpressionNode.h"                             // for LabelNode
+#include "InitializerNode.h"                            // for InitializerNode
 #include "ParseNode.h"
+#include "ParserTypes.h"                                // for Token
+#include "StatementNode.h"                              // for CondCtl, ForCtrl
 #include "TypedefTable.h"
+// This (generated) header must come late as it is missing includes.
+#include "parser.hh"                                    // generated info
 
 string * build_postfix_name( string * name );

src/Parser/module.mk

@@ -21 +21 @@
 SRC += \
        Parser/DeclarationNode.cc \
+       Parser/DeclarationNode.h \
        Parser/ExpressionNode.cc \
+       Parser/ExpressionNode.h \
        Parser/InitializerNode.cc \
+       Parser/InitializerNode.h \
        Parser/lex.ll \
        Parser/ParseNode.cc \
@@ -33 +36 @@
        Parser/RunParser.hpp \
        Parser/StatementNode.cc \
+       Parser/StatementNode.h \
        Parser/TypeData.cc \
        Parser/TypeData.h \

src/Parser/parser.yy

@@ -9 +9 @@
 // Author           : Peter A. Buhr
 // Created On       : Sat Sep  1 20:22:55 2001
-// Last Modified By : Andrew Beach
-// Last Modified On : Tue Apr  4 14:02:00 2023
-// Update Count     : 6329
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Wed Apr 26 16:45:37 2023
+// Update Count     : 6330
 //
 
@@ -48 +48 @@
 using namespace std;
 
-#include "SynTree/Declaration.h"
-#include "ParseNode.h"
+#include "SynTree/Type.h"                               // for Type
+#include "DeclarationNode.h"                            // for DeclarationNode, ...
+#include "ExpressionNode.h"                             // for ExpressionNode, ...
+#include "InitializerNode.h"                            // for InitializerNode, ...
+#include "ParserTypes.h"
+#include "StatementNode.h"                              // for build_...
 #include "TypedefTable.h"
 #include "TypeData.h"
-#include "SynTree/LinkageSpec.h"
 #include "Common/SemanticError.h"                                               // error_str
 #include "Common/utility.h"                                                             // for maybeMoveBuild, maybeBuild, CodeLo...
@@ -297 +300 @@
 %union {
         Token tok;
-        ParseNode * pn;
-        ExpressionNode * en;
+        ExpressionNode * expr;
         DeclarationNode * decl;
         ast::AggregateDecl::Aggregate aggKey;
         ast::TypeDecl::Kind tclass;
-        StatementNode * sn;
+        StatementNode * stmt;
+        ClauseNode * clause;
         ast::WaitForStmt * wfs;
-    ast::WaitUntilStmt::ClauseNode * wuscn;
-        ast::Expr * constant;
+    ast::WaitUntilStmt::ClauseNode * wucn;
         CondCtl * ifctl;
-        ForCtrl * fctl;
-        OperKinds compop;
-        LabelNode * label;
-        InitializerNode * in;
-        OperKinds op;
+        ForCtrl * forctl;
+        LabelNode * labels;
+        InitializerNode * init;
+        OperKinds oper;
         std::string * str;
-        bool flag;
-        EnumHiding hide;
-        ast::ExceptionKind catch_kind;
+        bool is_volatile;
+        EnumHiding enum_hiding;
+        ast::ExceptionKind except_kind;
         ast::GenericExpr * genexpr;
 }
@@ -381 +382 @@
 %type<tok> identifier                                   identifier_at                           identifier_or_type_name         attr_name
 %type<tok> quasi_keyword
-%type<constant> string_literal
+%type<expr> string_literal
 %type<str> string_literal_list
 
-%type<hide> hide_opt                                    visible_hide_opt
+%type<enum_hiding> hide_opt                                     visible_hide_opt
 
 // expressions
-%type<en> constant
-%type<en> tuple                                                 tuple_expression_list
-%type<op> ptrref_operator                               unary_operator                          assignment_operator                     simple_assignment_operator      compound_assignment_operator
-%type<en> primary_expression                    postfix_expression                      unary_expression
-%type<en> cast_expression_list                  cast_expression                         exponential_expression          multiplicative_expression       additive_expression
-%type<en> shift_expression                              relational_expression           equality_expression
-%type<en> AND_expression                                exclusive_OR_expression         inclusive_OR_expression
-%type<en> logical_AND_expression                logical_OR_expression
-%type<en> conditional_expression                constant_expression                     assignment_expression           assignment_expression_opt
-%type<en> comma_expression                              comma_expression_opt
-%type<en> argument_expression_list_opt  argument_expression_list        argument_expression                     default_initializer_opt
+%type<expr> constant
+%type<expr> tuple                                                       tuple_expression_list
+%type<oper> ptrref_operator                             unary_operator                          assignment_operator                     simple_assignment_operator      compound_assignment_operator
+%type<expr> primary_expression                  postfix_expression                      unary_expression
+%type<expr> cast_expression_list                        cast_expression                         exponential_expression          multiplicative_expression       additive_expression
+%type<expr> shift_expression                            relational_expression           equality_expression
+%type<expr> AND_expression                              exclusive_OR_expression         inclusive_OR_expression
+%type<expr> logical_AND_expression              logical_OR_expression
+%type<expr> conditional_expression              constant_expression                     assignment_expression           assignment_expression_opt
+%type<expr> comma_expression                            comma_expression_opt
+%type<expr> argument_expression_list_opt        argument_expression_list        argument_expression                     default_initializer_opt
 %type<ifctl> conditional_declaration
-%type<fctl> for_control_expression              for_control_expression_list
-%type<compop> upupeq updown updowneq downupdowneq
-%type<en> subrange
+%type<forctl> for_control_expression            for_control_expression_list
+%type<oper> upupeq updown updowneq downupdowneq
+%type<expr> subrange
 %type<decl> asm_name_opt
-%type<en> asm_operands_opt                              asm_operands_list                       asm_operand
-%type<label> label_list
-%type<en> asm_clobbers_list_opt
-%type<flag> asm_volatile_opt
-%type<en> handler_predicate_opt
+%type<expr> asm_operands_opt                            asm_operands_list                       asm_operand
+%type<labels> label_list
+%type<expr> asm_clobbers_list_opt
+%type<is_volatile> asm_volatile_opt
+%type<expr> handler_predicate_opt
 %type<genexpr> generic_association              generic_assoc_list
 
 // statements
-%type<sn> statement                                             labeled_statement                       compound_statement
-%type<sn> statement_decl                                statement_decl_list                     statement_list_nodecl
-%type<sn> selection_statement                   if_statement
-%type<sn> switch_clause_list_opt                switch_clause_list
-%type<en> case_value
-%type<sn> case_clause                                   case_value_list                         case_label                                      case_label_list
-%type<sn> iteration_statement                   jump_statement
-%type<sn> expression_statement                  asm_statement
-%type<sn> with_statement
-%type<en> with_clause_opt
-%type<sn> exception_statement                   handler_clause                          finally_clause
-%type<catch_kind> handler_key
-%type<sn> mutex_statement
-%type<en> when_clause                                   when_clause_opt                         waitfor         waituntil               timeout
-%type<sn> waitfor_statement                             waituntil_statement
+%type<stmt> statement                                           labeled_statement                       compound_statement
+%type<stmt> statement_decl                              statement_decl_list                     statement_list_nodecl
+%type<stmt> selection_statement                 if_statement
+%type<clause> switch_clause_list_opt            switch_clause_list
+%type<expr> case_value
+%type<clause> case_clause                               case_value_list                         case_label                                      case_label_list
+%type<stmt> iteration_statement                 jump_statement
+%type<stmt> expression_statement                        asm_statement
+%type<stmt> with_statement
+%type<expr> with_clause_opt
+%type<stmt> exception_statement
+%type<clause> handler_clause                    finally_clause
+%type<except_kind> handler_key
+%type<stmt> mutex_statement
+%type<expr> when_clause                                 when_clause_opt                         waitfor         waituntil               timeout
+%type<stmt> waitfor_statement                           waituntil_statement
 %type<wfs> wor_waitfor_clause
-%type<wuscn> waituntil_clause                   wand_waituntil_clause       wor_waituntil_clause
+%type<wucn> waituntil_clause                    wand_waituntil_clause       wor_waituntil_clause
 
 // declarations
@@ -439 +441 @@
 %type<decl> assertion assertion_list assertion_list_opt
 
-%type<en> bit_subrange_size_opt bit_subrange_size
+%type<expr> bit_subrange_size_opt bit_subrange_size
 
 %type<decl> basic_declaration_specifier basic_type_name basic_type_specifier direct_type indirect_type
@@ -452 +454 @@
 
 %type<decl> enumerator_list enum_type enum_type_nobody
-%type<in> enumerator_value_opt
+%type<init> enumerator_value_opt
 
 %type<decl> external_definition external_definition_list external_definition_list_opt
@@ -459 +461 @@
 
 %type<decl> field_declaration_list_opt field_declaration field_declaring_list_opt field_declarator field_abstract_list_opt field_abstract
-%type<en> field field_name_list field_name fraction_constants_opt
+%type<expr> field field_name_list field_name fraction_constants_opt
 
 %type<decl> external_function_definition function_definition function_array function_declarator function_no_ptr function_ptr
@@ -508 +510 @@
 %type<decl> type_parameter type_parameter_list type_initializer_opt
 
-%type<en> type_parameters_opt type_list array_type_list
+%type<expr> type_parameters_opt type_list array_type_list
 
 %type<decl> type_qualifier type_qualifier_name forall type_qualifier_list_opt type_qualifier_list
@@ -519 +521 @@
 
 // initializers
-%type<in>  initializer initializer_list_opt initializer_opt
+%type<init>  initializer initializer_list_opt initializer_opt
 
 // designators
-%type<en>  designator designator_list designation
+%type<expr>  designator designator_list designation
 
 
@@ -644 +646 @@
 
 string_literal:
-        string_literal_list                                                     { $$ = build_constantStr( yylloc, *$1 ); }
+        string_literal_list                                                     { $$ = new ExpressionNode( build_constantStr( yylloc, *$1 ) ); }
         ;
 
@@ -739 +741 @@
                 { $$ = new ExpressionNode( build_binary_val( yylloc, OperKinds::Index, $1, $3 ) ); }
         | string_literal '[' assignment_expression ']'          // "abc"[3], 3["abc"]
-                { $$ = new ExpressionNode( build_binary_val( yylloc, OperKinds::Index, new ExpressionNode( $1 ), $3 ) ); }
+                { $$ = new ExpressionNode( build_binary_val( yylloc, OperKinds::Index, $1, $3 ) ); }
         | postfix_expression '{' argument_expression_list_opt '}' // CFA, constructor call
                 {
@@ -757 +759 @@
                 { $$ = new ExpressionNode( build_func( yylloc, new ExpressionNode( build_varref( yylloc, build_postfix_name( $3 ) ) ), $1 ) ); }
         | string_literal '`' identifier                                         // CFA, postfix call
-                { $$ = new ExpressionNode( build_func( yylloc, new ExpressionNode( build_varref( yylloc, build_postfix_name( $3 ) ) ), new ExpressionNode( $1 ) ) ); }
+                { $$ = new ExpressionNode( build_func( yylloc, new ExpressionNode( build_varref( yylloc, build_postfix_name( $3 ) ) ), $1 ) ); }
         | postfix_expression '.' identifier
                 { $$ = new ExpressionNode( build_fieldSel( yylloc, $1, build_varref( yylloc, $3 ) ) ); }
@@ -857 +859 @@
         | constant
         | string_literal
-                { $$ = new ExpressionNode( $1 ); }
+                { $$ = $1; }
         | EXTENSION cast_expression                                                     // GCC
                 { $$ = $2->set_extension( true ); }
@@ -1260 +1262 @@
 
 case_value_list:                                                                                // CFA
-        case_value                                                                      { $$ = new StatementNode( build_case( $1 ) ); }
+        case_value                                                                      { $$ = new ClauseNode( build_case( yylloc, $1 ) ); }
                 // convert case list, e.g., "case 1, 3, 5:" into "case 1: case 3: case 5"
-        | case_value_list ',' case_value                        { $$ = (StatementNode *)($1->set_last( new StatementNode( build_case( $3 ) ) ) ); }
+        | case_value_list ',' case_value                        { $$ = $1->set_last( new ClauseNode( build_case( yylloc, $3 ) ) ); }
         ;
 
@@ -1271 +1273 @@
         | CASE case_value_list error                                            // syntax error
                 { SemanticError( yylloc, "Missing colon after case list." ); $$ = nullptr; }
-        | DEFAULT ':'                                                           { $$ = new StatementNode( build_default( yylloc ) ); }
+        | DEFAULT ':'                                                           { $$ = new ClauseNode( build_default( yylloc ) ); }
                 // A semantic check is required to ensure only one default clause per switch/choose statement.
         | DEFAULT error                                                                         //  syntax error
@@ -1279 +1281 @@
 case_label_list:                                                                                // CFA
         case_label
-        | case_label_list case_label                            { $$ = (StatementNode *)( $1->set_last( $2 )); }
+        | case_label_list case_label                            { $$ = $1->set_last( $2 ); }
         ;
 
@@ -1296 +1298 @@
                 { $$ = $1->append_last_case( new StatementNode( build_compound( yylloc, $2 ) ) ); }
         | switch_clause_list case_label_list statement_list_nodecl
-                { $$ = (StatementNode *)( $1->set_last( $2->append_last_case( new StatementNode( build_compound( yylloc, $3 ) ) ) ) ); }
+                { $$ = $1->set_last( $2->append_last_case( new StatementNode( build_compound( yylloc, $3 ) ) ) ); }
         ;
 
@@ -1679 +1681 @@
 
 waituntil:
-        WAITUNTIL '(' cast_expression ')'
+        WAITUNTIL '(' comma_expression ')'
                 { $$ = $3; }
         ;
@@ -1736 +1738 @@
 handler_clause:
         handler_key '(' push exception_declaration pop handler_predicate_opt ')' compound_statement
-                { $$ = new StatementNode( build_catch( yylloc, $1, $4, $6, $8 ) ); }
+                { $$ = new ClauseNode( build_catch( yylloc, $1, $4, $6, $8 ) ); }
         | handler_clause handler_key '(' push exception_declaration pop handler_predicate_opt ')' compound_statement
-                { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( yylloc, $2, $5, $7, $9 ) ) ); }
+                { $$ = $1->set_last( new ClauseNode( build_catch( yylloc, $2, $5, $7, $9 ) ) ); }
         ;
 
@@ -1755 +1757 @@
 
 finally_clause:
-        FINALLY compound_statement                                      { $$ = new StatementNode( build_finally( yylloc, $2 ) ); }
+        FINALLY compound_statement                                      { $$ = new ClauseNode( build_finally( yylloc, $2 ) ); }
         ;
 
@@ -1813 +1815 @@
 asm_operand:                                                                                    // GCC
         string_literal '(' constant_expression ')'
-                { $$ = new ExpressionNode( new ast::AsmExpr( yylloc, "", $1, maybeMoveBuild( $3 ) ) ); }
+                { $$ = new ExpressionNode( new ast::AsmExpr( yylloc, "", maybeMoveBuild( $1 ), maybeMoveBuild( $3 ) ) ); }
         | '[' IDENTIFIER ']' string_literal '(' constant_expression ')'
                 {
-                        $$ = new ExpressionNode( new ast::AsmExpr( yylloc, *$2.str, $4, maybeMoveBuild( $6 ) ) );
+                        $$ = new ExpressionNode( new ast::AsmExpr( yylloc, *$2.str, maybeMoveBuild( $4 ), maybeMoveBuild( $6 ) ) );
                         delete $2.str;
                 }
@@ -1825 +1827 @@
                 { $$ = nullptr; }                                                               // use default argument
         | string_literal
-                { $$ = new ExpressionNode( $1 ); }
+                { $$ = $1; }
         | asm_clobbers_list_opt ',' string_literal
-                { $$ = (ExpressionNode *)($1->set_last( new ExpressionNode( $3 ) )); }
+                { $$ = (ExpressionNode *)( $1->set_last( $3 ) ); }
         ;
 
@@ -1899 +1901 @@
 static_assert:
         STATICASSERT '(' constant_expression ',' string_literal ')' ';' // C11
-                { $$ = DeclarationNode::newStaticAssert( $3, $5 ); }
+                { $$ = DeclarationNode::newStaticAssert( $3, maybeMoveBuild( $5 ) ); }
         | STATICASSERT '(' constant_expression ')' ';'          // CFA
                 { $$ = DeclarationNode::newStaticAssert( $3, build_constantStr( yylloc, *new string( "\"\"" ) ) ); }
@@ -3329 +3331 @@
                 {
                         DeclarationNode * name = new DeclarationNode();
-                        name->asmName = $3;
+                        name->asmName = maybeMoveBuild( $3 );
                         $$ = name->addQualifiers( $5 );
                 }

src/Parser/parserutility.h

@@ -24 +24 @@
 
 template< typename T >
-static inline auto maybeBuild( const T *orig ) -> decltype(orig->build()) {
+static inline auto maybeBuild( T * orig ) -> decltype(orig->build()) {
         return (orig) ? orig->build() : nullptr;
 }
 
 template< typename T >
-static inline auto maybeMoveBuild( const T *orig ) -> decltype(orig->build()) {
+static inline auto maybeMoveBuild( T * orig ) -> decltype(orig->build()) {
         auto ret = maybeBuild<T>(orig);
         delete orig;

src/ResolvExpr/CandidateFinder.cpp

@@ -55 +55 @@
 namespace ResolvExpr {
 
+/// Unique identifier for matching expression resolutions to their requesting expression
+UniqueId globalResnSlot = 0;
+
+namespace {
+        /// First index is which argument, second is which alternative, third is which exploded element
+        using ExplodedArgs_new = std::deque< std::vector< ExplodedArg > >;
+
+        /// Returns a list of alternatives with the minimum cost in the given list
+        CandidateList findMinCost( const CandidateList & candidates ) {
+                CandidateList out;
+                Cost minCost = Cost::infinity;
+                for ( const CandidateRef & r : candidates ) {
+                        if ( r->cost < minCost ) {
+                                minCost = r->cost;
+                                out.clear();
+                                out.emplace_back( r );
+                        } else if ( r->cost == minCost ) {
+                                out.emplace_back( r );
+                        }
+                }
+                return out;
+        }
+
+        /// Computes conversion cost for a given expression to a given type
+        const ast::Expr * computeExpressionConversionCost(
+                const ast::Expr * arg, const ast::Type * paramType, const ast::SymbolTable & symtab, const ast::TypeEnvironment & env, Cost & outCost
+        ) {
+                Cost convCost = computeConversionCost(
+                                arg->result, paramType, arg->get_lvalue(), symtab, env );
+                outCost += convCost;
+
+                // If there is a non-zero conversion cost, ignoring poly cost, then the expression requires
+                // conversion. Ignore poly cost for now, since this requires resolution of the cast to
+                // infer parameters and this does not currently work for the reason stated below
+                Cost tmpCost = convCost;
+                tmpCost.incPoly( -tmpCost.get_polyCost() );
+                if ( tmpCost != Cost::zero ) {
+                        ast::ptr< ast::Type > newType = paramType;
+                        env.apply( newType );
+                        return new ast::CastExpr{ arg, newType };
+
+                        // xxx - *should* be able to resolve this cast, but at the moment pointers are not
+                        // castable to zero_t, but are implicitly convertible. This is clearly inconsistent,
+                        // once this is fixed it should be possible to resolve the cast.
+                        // xxx - this isn't working, it appears because type1 (parameter) is seen as widenable,
+                        // but it shouldn't be because this makes the conversion from DT* to DT* since
+                        // commontype(zero_t, DT*) is DT*, rather than nothing
+
+                        // CandidateFinder finder{ symtab, env };
+                        // finder.find( arg, ResolvMode::withAdjustment() );
+                        // assertf( finder.candidates.size() > 0,
+                        //      "Somehow castable expression failed to find alternatives." );
+                        // assertf( finder.candidates.size() == 1,
+                        //      "Somehow got multiple alternatives for known cast expression." );
+                        // return finder.candidates.front()->expr;
+                }
+
+                return arg;
+        }
+
+        /// Computes conversion cost for a given candidate
+        Cost computeApplicationConversionCost(
+                CandidateRef cand, const ast::SymbolTable & symtab
+        ) {
+                auto appExpr = cand->expr.strict_as< ast::ApplicationExpr >();
+                auto pointer = appExpr->func->result.strict_as< ast::PointerType >();
+                auto function = pointer->base.strict_as< ast::FunctionType >();
+
+                Cost convCost = Cost::zero;
+                const auto & params = function->params;
+                auto param = params.begin();
+                auto & args = appExpr->args;
+
+                for ( unsigned i = 0; i < args.size(); ++i ) {
+                        const ast::Type * argType = args[i]->result;
+                        PRINT(
+                                std::cerr << "arg expression:" << std::endl;
+                                ast::print( std::cerr, args[i], 2 );
+                                std::cerr << "--- results are" << std::endl;
+                                ast::print( std::cerr, argType, 2 );
+                        )
+
+                        if ( param == params.end() ) {
+                                if ( function->isVarArgs ) {
+                                        convCost.incUnsafe();
+                                        PRINT( std::cerr << "end of params with varargs function: inc unsafe: "
+                                                << convCost << std::endl; ; )
+                                        // convert reference-typed expressions into value-typed expressions
+                                        cand->expr = ast::mutate_field_index(
+                                                appExpr, &ast::ApplicationExpr::args, i,
+                                                referenceToRvalueConversion( args[i], convCost ) );
+                                        continue;
+                                } else return Cost::infinity;
+                        }
+
+                        if ( auto def = args[i].as< ast::DefaultArgExpr >() ) {
+                                // Default arguments should be free - don't include conversion cost.
+                                // Unwrap them here because they are not relevant to the rest of the system
+                                cand->expr = ast::mutate_field_index(
+                                        appExpr, &ast::ApplicationExpr::args, i, def->expr );
+                                ++param;
+                                continue;
+                        }
+
+                        // mark conversion cost and also specialization cost of param type
+                        // const ast::Type * paramType = (*param)->get_type();
+                        cand->expr = ast::mutate_field_index(
+                                appExpr, &ast::ApplicationExpr::args, i,
+                                computeExpressionConversionCost(
+                                        args[i], *param, symtab, cand->env, convCost ) );
+                        convCost.decSpec( specCost( *param ) );
+                        ++param;  // can't be in for-loop update because of the continue
+                }
+
+                if ( param != params.end() ) return Cost::infinity;
+
+                // specialization cost of return types can't be accounted for directly, it disables
+                // otherwise-identical calls, like this example based on auto-newline in the I/O lib:
+                //
+                //   forall(otype OS) {
+                //     void ?|?(OS&, int);  // with newline
+                //     OS&  ?|?(OS&, int);  // no newline, always chosen due to more specialization
+                //   }
+
+                // mark type variable and specialization cost of forall clause
+                convCost.incVar( function->forall.size() );
+                convCost.decSpec( function->assertions.size() );
+
+                return convCost;
+        }
+
+        void makeUnifiableVars(
+                const ast::FunctionType * type, ast::OpenVarSet & unifiableVars,
+                ast::AssertionSet & need
+        ) {
+                for ( auto & tyvar : type->forall ) {
+                        unifiableVars[ *tyvar ] = ast::TypeData{ tyvar->base };
+                }
+                for ( auto & assn : type->assertions ) {
+                        need[ assn ].isUsed = true;
+                }
+        }
+
+        /// Gets a default value from an initializer, nullptr if not present
+        const ast::ConstantExpr * getDefaultValue( const ast::Init * init ) {
+                if ( auto si = dynamic_cast< const ast::SingleInit * >( init ) ) {
+                        if ( auto ce = si->value.as< ast::CastExpr >() ) {
+                                return ce->arg.as< ast::ConstantExpr >();
+                        } else {
+                                return si->value.as< ast::ConstantExpr >();
+                        }
+                }
+                return nullptr;
+        }
+
+        /// State to iteratively build a match of parameter expressions to arguments
+        struct ArgPack {
+                std::size_t parent;          ///< Index of parent pack
+                ast::ptr< ast::Expr > expr;  ///< The argument stored here
+                Cost cost;                   ///< The cost of this argument
+                ast::TypeEnvironment env;    ///< Environment for this pack
+                ast::AssertionSet need;      ///< Assertions outstanding for this pack
+                ast::AssertionSet have;      ///< Assertions found for this pack
+                ast::OpenVarSet open;        ///< Open variables for this pack
+                unsigned nextArg;            ///< Index of next argument in arguments list
+                unsigned tupleStart;         ///< Number of tuples that start at this index
+                unsigned nextExpl;           ///< Index of next exploded element
+                unsigned explAlt;            ///< Index of alternative for nextExpl > 0
+
+                ArgPack()
+                : parent( 0 ), expr(), cost( Cost::zero ), env(), need(), have(), open(), nextArg( 0 ),
+                  tupleStart( 0 ), nextExpl( 0 ), explAlt( 0 ) {}
+
+                ArgPack(
+                        const ast::TypeEnvironment & env, const ast::AssertionSet & need,
+                        const ast::AssertionSet & have, const ast::OpenVarSet & open )
+                : parent( 0 ), expr(), cost( Cost::zero ), env( env ), need( need ), have( have ),
+                  open( open ), nextArg( 0 ), tupleStart( 0 ), nextExpl( 0 ), explAlt( 0 ) {}
+
+                ArgPack(
+                        std::size_t parent, const ast::Expr * expr, ast::TypeEnvironment && env,
+                        ast::AssertionSet && need, ast::AssertionSet && have, ast::OpenVarSet && open,
+                        unsigned nextArg, unsigned tupleStart = 0, Cost cost = Cost::zero,
+                        unsigned nextExpl = 0, unsigned explAlt = 0 )
+                : parent(parent), expr( expr ), cost( cost ), env( std::move( env ) ), need( std::move( need ) ),
+                  have( std::move( have ) ), open( std::move( open ) ), nextArg( nextArg ), tupleStart( tupleStart ),
+                  nextExpl( nextExpl ), explAlt( explAlt ) {}
+
+                ArgPack(
+                        const ArgPack & o, ast::TypeEnvironment && env, ast::AssertionSet && need,
+                        ast::AssertionSet && have, ast::OpenVarSet && open, unsigned nextArg, Cost added )
+                : parent( o.parent ), expr( o.expr ), cost( o.cost + added ), env( std::move( env ) ),
+                  need( std::move( need ) ), have( std::move( have ) ), open( std::move( open ) ), nextArg( nextArg ),
+                  tupleStart( o.tupleStart ), nextExpl( 0 ), explAlt( 0 ) {}
+
+                /// true if this pack is in the middle of an exploded argument
+                bool hasExpl() const { return nextExpl > 0; }
+
+                /// Gets the list of exploded candidates for this pack
+                const ExplodedArg & getExpl( const ExplodedArgs_new & args ) const {
+                        return args[ nextArg-1 ][ explAlt ];
+                }
+
+                /// Ends a tuple expression, consolidating the appropriate args
+                void endTuple( const std::vector< ArgPack > & packs ) {
+                        // add all expressions in tuple to list, summing cost
+                        std::deque< const ast::Expr * > exprs;
+                        const ArgPack * pack = this;
+                        if ( expr ) { exprs.emplace_front( expr ); }
+                        while ( pack->tupleStart == 0 ) {
+                                pack = &packs[pack->parent];
+                                exprs.emplace_front( pack->expr );
+                                cost += pack->cost;
+                        }
+                        // reset pack to appropriate tuple
+                        std::vector< ast::ptr< ast::Expr > > exprv( exprs.begin(), exprs.end() );
+                        expr = new ast::TupleExpr{ expr->location, std::move( exprv ) };
+                        tupleStart = pack->tupleStart - 1;
+                        parent = pack->parent;
+                }
+        };
+
+        /// Instantiates an argument to match a parameter, returns false if no matching results left
+        bool instantiateArgument(
+                const CodeLocation & location,
+                const ast::Type * paramType, const ast::Init * init, const ExplodedArgs_new & args,
+                std::vector< ArgPack > & results, std::size_t & genStart, const ast::SymbolTable & symtab,
+                unsigned nTuples = 0
+        ) {
+                if ( auto tupleType = dynamic_cast< const ast::TupleType * >( paramType ) ) {
+                        // paramType is a TupleType -- group args into a TupleExpr
+                        ++nTuples;
+                        for ( const ast::Type * type : *tupleType ) {
+                                // xxx - dropping initializer changes behaviour from previous, but seems correct
+                                // ^^^ need to handle the case where a tuple has a default argument
+                                if ( ! instantiateArgument( location,
+                                        type, nullptr, args, results, genStart, symtab, nTuples ) ) return false;
+                                nTuples = 0;
+                        }
+                        // re-constitute tuples for final generation
+                        for ( auto i = genStart; i < results.size(); ++i ) {
+                                results[i].endTuple( results );
+                        }
+                        return true;
+                } else if ( const ast::TypeInstType * ttype = Tuples::isTtype( paramType ) ) {
+                        // paramType is a ttype, consumes all remaining arguments
+
+                        // completed tuples; will be spliced to end of results to finish
+                        std::vector< ArgPack > finalResults{};
+
+                        // iterate until all results completed
+                        std::size_t genEnd;
+                        ++nTuples;
+                        do {
+                                genEnd = results.size();
+
+                                // add another argument to results
+                                for ( std::size_t i = genStart; i < genEnd; ++i ) {
+                                        unsigned nextArg = results[i].nextArg;
+
+                                        // use next element of exploded tuple if present
+                                        if ( results[i].hasExpl() ) {
+                                                const ExplodedArg & expl = results[i].getExpl( args );
+
+                                                unsigned nextExpl = results[i].nextExpl + 1;
+                                                if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
+
+                                                results.emplace_back(
+                                                        i, expl.exprs[ results[i].nextExpl ], copy( results[i].env ),
+                                                        copy( results[i].need ), copy( results[i].have ),
+                                                        copy( results[i].open ), nextArg, nTuples, Cost::zero, nextExpl,
+                                                        results[i].explAlt );
+
+                                                continue;
+                                        }
+
+                                        // finish result when out of arguments
+                                        if ( nextArg >= args.size() ) {
+                                                ArgPack newResult{
+                                                        results[i].env, results[i].need, results[i].have, results[i].open };
+                                                newResult.nextArg = nextArg;
+                                                const ast::Type * argType = nullptr;
+
+                                                if ( nTuples > 0 || ! results[i].expr ) {
+                                                        // first iteration or no expression to clone,
+                                                        // push empty tuple expression
+                                                        newResult.parent = i;
+                                                        newResult.expr = new ast::TupleExpr( location, {} );
+                                                        argType = newResult.expr->result;
+                                                } else {
+                                                        // clone result to collect tuple
+                                                        newResult.parent = results[i].parent;
+                                                        newResult.cost = results[i].cost;
+                                                        newResult.tupleStart = results[i].tupleStart;
+                                                        newResult.expr = results[i].expr;
+                                                        argType = newResult.expr->result;
+
+                                                        if ( results[i].tupleStart > 0 && Tuples::isTtype( argType ) ) {
+                                                                // the case where a ttype value is passed directly is special,
+                                                                // e.g. for argument forwarding purposes
+                                                                // xxx - what if passing multiple arguments, last of which is
+                                                                //       ttype?
+                                                                // xxx - what would happen if unify was changed so that unifying
+                                                                //       tuple
+                                                                // types flattened both before unifying lists? then pass in
+                                                                // TupleType (ttype) below.
+                                                                --newResult.tupleStart;
+                                                        } else {
+                                                                // collapse leftover arguments into tuple
+                                                                newResult.endTuple( results );
+                                                                argType = newResult.expr->result;
+                                                        }
+                                                }
+
+                                                // check unification for ttype before adding to final
+                                                if (
+                                                        unify(
+                                                                ttype, argType, newResult.env, newResult.need, newResult.have,
+                                                                newResult.open, symtab )
+                                                ) {
+                                                        finalResults.emplace_back( std::move( newResult ) );
+                                                }
+
+                                                continue;
+                                        }
+
+                                        // add each possible next argument
+                                        for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
+                                                const ExplodedArg & expl = args[nextArg][j];
+
+                                                // fresh copies of parent parameters for this iteration
+                                                ast::TypeEnvironment env = results[i].env;
+                                                ast::OpenVarSet open = results[i].open;
+
+                                                env.addActual( expl.env, open );
+
+                                                // skip empty tuple arguments by (nearly) cloning parent into next gen
+                                                if ( expl.exprs.empty() ) {
+                                                        results.emplace_back(
+                                                                results[i], std::move( env ), copy( results[i].need ),
+                                                                copy( results[i].have ), std::move( open ), nextArg + 1, expl.cost );
+
+                                                        continue;
+                                                }
+
+                                                // add new result
+                                                results.emplace_back(
+                                                        i, expl.exprs.front(), std::move( env ), copy( results[i].need ),
+                                                        copy( results[i].have ), std::move( open ), nextArg + 1, nTuples,
+                                                        expl.cost, expl.exprs.size() == 1 ? 0 : 1, j );
+                                        }
+                                }
+
+                                // reset for next round
+                                genStart = genEnd;
+                                nTuples = 0;
+                        } while ( genEnd != results.size() );
+
+                        // splice final results onto results
+                        for ( std::size_t i = 0; i < finalResults.size(); ++i ) {
+                                results.emplace_back( std::move( finalResults[i] ) );
+                        }
+                        return ! finalResults.empty();
+                }
+
+                // iterate each current subresult
+                std::size_t genEnd = results.size();
+                for ( std::size_t i = genStart; i < genEnd; ++i ) {
+                        unsigned nextArg = results[i].nextArg;
+
+                        // use remainder of exploded tuple if present
+                        if ( results[i].hasExpl() ) {
+                                const ExplodedArg & expl = results[i].getExpl( args );
+                                const ast::Expr * expr = expl.exprs[ results[i].nextExpl ];
+
+                                ast::TypeEnvironment env = results[i].env;
+                                ast::AssertionSet need = results[i].need, have = results[i].have;
+                                ast::OpenVarSet open = results[i].open;
+
+                                const ast::Type * argType = expr->result;
+
+                                PRINT(
+                                        std::cerr << "param type is ";
+                                        ast::print( std::cerr, paramType );
+                                        std::cerr << std::endl << "arg type is ";
+                                        ast::print( std::cerr, argType );
+                                        std::cerr << std::endl;
+                                )
+
+                                if ( unify( paramType, argType, env, need, have, open, symtab ) ) {
+                                        unsigned nextExpl = results[i].nextExpl + 1;
+                                        if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
+
+                                        results.emplace_back(
+                                                i, expr, std::move( env ), std::move( need ), std::move( have ), std::move( open ), nextArg,
+                                                nTuples, Cost::zero, nextExpl, results[i].explAlt );
+                                }
+
+                                continue;
+                        }
+
+                        // use default initializers if out of arguments
+                        if ( nextArg >= args.size() ) {
+                                if ( const ast::ConstantExpr * cnst = getDefaultValue( init ) ) {
+                                        ast::TypeEnvironment env = results[i].env;
+                                        ast::AssertionSet need = results[i].need, have = results[i].have;
+                                        ast::OpenVarSet open = results[i].open;
+
+                                        if ( unify( paramType, cnst->result, env, need, have, open, symtab ) ) {
+                                                results.emplace_back(
+                                                        i, new ast::DefaultArgExpr{ cnst->location, cnst }, std::move( env ),
+                                                        std::move( need ), std::move( have ), std::move( open ), nextArg, nTuples );
+                                        }
+                                }
+
+                                continue;
+                        }
+
+                        // Check each possible next argument
+                        for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
+                                const ExplodedArg & expl = args[nextArg][j];
+
+                                // fresh copies of parent parameters for this iteration
+                                ast::TypeEnvironment env = results[i].env;
+                                ast::AssertionSet need = results[i].need, have = results[i].have;
+                                ast::OpenVarSet open = results[i].open;
+
+                                env.addActual( expl.env, open );
+
+                                // skip empty tuple arguments by (nearly) cloning parent into next gen
+                                if ( expl.exprs.empty() ) {
+                                        results.emplace_back(
+                                                results[i], std::move( env ), std::move( need ), std::move( have ), std::move( open ),
+                                                nextArg + 1, expl.cost );
+
+                                        continue;
+                                }
+
+                                // consider only first exploded arg
+                                const ast::Expr * expr = expl.exprs.front();
+                                const ast::Type * argType = expr->result;
+
+                                PRINT(
+                                        std::cerr << "param type is ";
+                                        ast::print( std::cerr, paramType );
+                                        std::cerr << std::endl << "arg type is ";
+                                        ast::print( std::cerr, argType );
+                                        std::cerr << std::endl;
+                                )
+
+                                // attempt to unify types
+                                if ( unify( paramType, argType, env, need, have, open, symtab ) ) {
+                                        // add new result
+                                        results.emplace_back(
+                                                i, expr, std::move( env ), std::move( need ), std::move( have ), std::move( open ),
+                                                nextArg + 1, nTuples, expl.cost, expl.exprs.size() == 1 ? 0 : 1, j );
+                                }
+                        }
+                }
+
+                // reset for next parameter
+                genStart = genEnd;
+
+                return genEnd != results.size();  // were any new results added?
+        }
+
+        /// Generate a cast expression from `arg` to `toType`
+        const ast::Expr * restructureCast(
+                ast::ptr< ast::Expr > & arg, const ast::Type * toType, ast::GeneratedFlag isGenerated = ast::GeneratedCast
+        ) {
+                if (
+                        arg->result->size() > 1
+                        && ! toType->isVoid()
+                        && ! dynamic_cast< const ast::ReferenceType * >( toType )
+                ) {
+                        // Argument is a tuple and the target type is neither void nor a reference. Cast each
+                        // member of the tuple to its corresponding target type, producing the tuple of those
+                        // cast expressions. If there are more components of the tuple than components in the
+                        // target type, then excess components do not come out in the result expression (but
+                        // UniqueExpr ensures that the side effects will still be produced)
+                        if ( Tuples::maybeImpureIgnoreUnique( arg ) ) {
+                                // expressions which may contain side effects require a single unique instance of
+                                // the expression
+                                arg = new ast::UniqueExpr{ arg->location, arg };
+                        }
+                        std::vector< ast::ptr< ast::Expr > > components;
+                        for ( unsigned i = 0; i < toType->size(); ++i ) {
+                                // cast each component
+                                ast::ptr< ast::Expr > idx = new ast::TupleIndexExpr{ arg->location, arg, i };
+                                components.emplace_back(
+                                        restructureCast( idx, toType->getComponent( i ), isGenerated ) );
+                        }
+                        return new ast::TupleExpr{ arg->location, std::move( components ) };
+                } else {
+                        // handle normally
+                        return new ast::CastExpr{ arg->location, arg, toType, isGenerated };
+                }
+        }
+
+        /// Gets the name from an untyped member expression (must be NameExpr)
+        const std::string & getMemberName( const ast::UntypedMemberExpr * memberExpr ) {
+                if ( memberExpr->member.as< ast::ConstantExpr >() ) {
+                        SemanticError( memberExpr, "Indexed access to struct fields unsupported: " );
+                }
+
+                return memberExpr->member.strict_as< ast::NameExpr >()->name;
+        }
+
+        /// Actually visits expressions to find their candidate interpretations
+        class Finder final : public ast::WithShortCircuiting {
+                const ResolveContext & context;
+                const ast::SymbolTable & symtab;
+        public:
+                // static size_t traceId;
+                CandidateFinder & selfFinder;
+                CandidateList & candidates;
+                const ast::TypeEnvironment & tenv;
+                ast::ptr< ast::Type > & targetType;
+
+                enum Errors {
+                        NotFound,
+                        NoMatch,
+                        ArgsToFew,
+                        ArgsToMany,
+                        RetsToFew,
+                        RetsToMany,
+                        NoReason
+                };
+
+                struct {
+                        Errors code = NotFound;
+                } reason;
+
+                Finder( CandidateFinder & f )
+                : context( f.context ), symtab( context.symtab ), selfFinder( f ),
+                  candidates( f.candidates ), tenv( f.env ), targetType( f.targetType ) {}
+
+                void previsit( const ast::Node * ) { visit_children = false; }
+
+                /// Convenience to add candidate to list
+                template<typename... Args>
+                void addCandidate( Args &&... args ) {
+                        candidates.emplace_back( new Candidate{ std::forward<Args>( args )... } );
+                        reason.code = NoReason;
+                }
+
+                void postvisit( const ast::ApplicationExpr * applicationExpr ) {
+                        addCandidate( applicationExpr, tenv );
+                }
+
+                /// Set up candidate assertions for inference
+                void inferParameters( CandidateRef & newCand, CandidateList & out );
+
+                /// Completes a function candidate with arguments located
+                void validateFunctionCandidate(
+                        const CandidateRef & func, ArgPack & result, const std::vector< ArgPack > & results,
+                        CandidateList & out );
+
+                /// Builds a list of candidates for a function, storing them in out
+                void makeFunctionCandidates(
+                        const CodeLocation & location,
+                        const CandidateRef & func, const ast::FunctionType * funcType,
+                        const ExplodedArgs_new & args, CandidateList & out );
+
+                /// Adds implicit struct-conversions to the alternative list
+                void addAnonConversions( const CandidateRef & cand );
+
+                /// Adds aggregate member interpretations
+                void addAggMembers(
+                        const ast::BaseInstType * aggrInst, const ast::Expr * expr,
+                        const Candidate & cand, const Cost & addedCost, const std::string & name
+                );
+
+                /// Adds tuple member interpretations
+                void addTupleMembers(
+                        const ast::TupleType * tupleType, const ast::Expr * expr, const Candidate & cand,
+                        const Cost & addedCost, const ast::Expr * member
+                );
+
+                /// true if expression is an lvalue
+                static bool isLvalue( const ast::Expr * x ) {
+                        return x->result && ( x->get_lvalue() || x->result.as< ast::ReferenceType >() );
+                }
+
+                void postvisit( const ast::UntypedExpr * untypedExpr );
+                void postvisit( const ast::VariableExpr * variableExpr );
+                void postvisit( const ast::ConstantExpr * constantExpr );
+                void postvisit( const ast::SizeofExpr * sizeofExpr );
+                void postvisit( const ast::AlignofExpr * alignofExpr );
+                void postvisit( const ast::AddressExpr * addressExpr );
+                void postvisit( const ast::LabelAddressExpr * labelExpr );
+                void postvisit( const ast::CastExpr * castExpr );
+                void postvisit( const ast::VirtualCastExpr * castExpr );
+                void postvisit( const ast::KeywordCastExpr * castExpr );
+                void postvisit( const ast::UntypedMemberExpr * memberExpr );
+                void postvisit( const ast::MemberExpr * memberExpr );
+                void postvisit( const ast::NameExpr * nameExpr );
+                void postvisit( const ast::UntypedOffsetofExpr * offsetofExpr );
+                void postvisit( const ast::OffsetofExpr * offsetofExpr );
+                void postvisit( const ast::OffsetPackExpr * offsetPackExpr );
+                void postvisit( const ast::LogicalExpr * logicalExpr );
+                void postvisit( const ast::ConditionalExpr * conditionalExpr );
+                void postvisit( const ast::CommaExpr * commaExpr );
+                void postvisit( const ast::ImplicitCopyCtorExpr * ctorExpr );
+                void postvisit( const ast::ConstructorExpr * ctorExpr );
+                void postvisit( const ast::RangeExpr * rangeExpr );
+                void postvisit( const ast::UntypedTupleExpr * tupleExpr );
+                void postvisit( const ast::TupleExpr * tupleExpr );
+                void postvisit( const ast::TupleIndexExpr * tupleExpr );
+                void postvisit( const ast::TupleAssignExpr * tupleExpr );
+                void postvisit( const ast::UniqueExpr * unqExpr );
+                void postvisit( const ast::StmtExpr * stmtExpr );
+                void postvisit( const ast::UntypedInitExpr * initExpr );
+
+                void postvisit( const ast::InitExpr * ) {
+                        assertf( false, "CandidateFinder should never see a resolved InitExpr." );
+                }
+
+                void postvisit( const ast::DeletedExpr * ) {
+                        assertf( false, "CandidateFinder should never see a DeletedExpr." );
+                }
+
+                void postvisit( const ast::GenericExpr * ) {
+                        assertf( false, "_Generic is not yet supported." );
+                }
+        };
+
+        /// Set up candidate assertions for inference
+        void Finder::inferParameters( CandidateRef & newCand, CandidateList & out ) {
+                // Set need bindings for any unbound assertions
+                UniqueId crntResnSlot = 0; // matching ID for this expression's assertions
+                for ( auto & assn : newCand->need ) {
+                        // skip already-matched assertions
+                        if ( assn.second.resnSlot != 0 ) continue;
+                        // assign slot for expression if needed
+                        if ( crntResnSlot == 0 ) { crntResnSlot = ++globalResnSlot; }
+                        // fix slot to assertion
+                        assn.second.resnSlot = crntResnSlot;
+                }
+                // pair slot to expression
+                if ( crntResnSlot != 0 ) {
+                        newCand->expr.get_and_mutate()->inferred.resnSlots().emplace_back( crntResnSlot );
+                }
+
+                // add to output list; assertion satisfaction will occur later
+                out.emplace_back( newCand );
+        }
+
+        /// Completes a function candidate with arguments located
+        void Finder::validateFunctionCandidate(
+                const CandidateRef & func, ArgPack & result, const std::vector< ArgPack > & results,
+                CandidateList & out
+        ) {
+                ast::ApplicationExpr * appExpr =
+                        new ast::ApplicationExpr{ func->expr->location, func->expr };
+                // sum cost and accumulate arguments
+                std::deque< const ast::Expr * > args;
+                Cost cost = func->cost;
+                const ArgPack * pack = &result;
+                while ( pack->expr ) {
+                        args.emplace_front( pack->expr );
+                        cost += pack->cost;
+                        pack = &results[pack->parent];
+                }
+                std::vector< ast::ptr< ast::Expr > > vargs( args.begin(), args.end() );
+                appExpr->args = std::move( vargs );
+                // build and validate new candidate
+                auto newCand =
+                        std::make_shared<Candidate>( appExpr, result.env, result.open, result.need, cost );
+                PRINT(
+                        std::cerr << "instantiate function success: " << appExpr << std::endl;
+                        std::cerr << "need assertions:" << std::endl;
+                        ast::print( std::cerr, result.need, 2 );
+                )
+                inferParameters( newCand, out );
+        }
+
+        /// Builds a list of candidates for a function, storing them in out
+        void Finder::makeFunctionCandidates(
+                const CodeLocation & location,
+                const CandidateRef & func, const ast::FunctionType * funcType,
+                const ExplodedArgs_new & args, CandidateList & out
+        ) {
+                ast::OpenVarSet funcOpen;
+                ast::AssertionSet funcNeed, funcHave;
+                ast::TypeEnvironment funcEnv{ func->env };
+                makeUnifiableVars( funcType, funcOpen, funcNeed );
+                // add all type variables as open variables now so that those not used in the
+                // parameter list are still considered open
+                funcEnv.add( funcType->forall );
+
+                if ( targetType && ! targetType->isVoid() && ! funcType->returns.empty() ) {
+                        // attempt to narrow based on expected target type
+                        const ast::Type * returnType = funcType->returns.front();
+                        if ( ! unify(
+                                returnType, targetType, funcEnv, funcNeed, funcHave, funcOpen, symtab )
+                        ) {
+                                // unification failed, do not pursue this candidate
+                                return;
+                        }
+                }
+
+                // iteratively build matches, one parameter at a time
+                std::vector< ArgPack > results;
+                results.emplace_back( funcEnv, funcNeed, funcHave, funcOpen );
+                std::size_t genStart = 0;
+
+                // xxx - how to handle default arg after change to ftype representation?
+                if (const ast::VariableExpr * varExpr = func->expr.as<ast::VariableExpr>()) {
+                        if (const ast::FunctionDecl * funcDecl = varExpr->var.as<ast::FunctionDecl>()) {
+                                // function may have default args only if directly calling by name
+                                // must use types on candidate however, due to RenameVars substitution
+                                auto nParams = funcType->params.size();
+
+                                for (size_t i=0; i<nParams; ++i) {
+                                        auto obj = funcDecl->params[i].strict_as<ast::ObjectDecl>();
+                                        if (!instantiateArgument( location,
+                                                funcType->params[i], obj->init, args, results, genStart, symtab)) return;
+                                }
+                                goto endMatch;
+                        }
+                }
+                for ( const auto & param : funcType->params ) {
+                        // Try adding the arguments corresponding to the current parameter to the existing
+                        // matches
+                        // no default args for indirect calls
+                        if ( ! instantiateArgument( location,
+                                param, nullptr, args, results, genStart, symtab ) ) return;
+                }
+
+                endMatch:
+                if ( funcType->isVarArgs ) {
+                        // append any unused arguments to vararg pack
+                        std::size_t genEnd;
+                        do {
+                                genEnd = results.size();
+
+                                // iterate results
+                                for ( std::size_t i = genStart; i < genEnd; ++i ) {
+                                        unsigned nextArg = results[i].nextArg;
+
+                                        // use remainder of exploded tuple if present
+                                        if ( results[i].hasExpl() ) {
+                                                const ExplodedArg & expl = results[i].getExpl( args );
+
+                                                unsigned nextExpl = results[i].nextExpl + 1;
+                                                if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
+
+                                                results.emplace_back(
+                                                        i, expl.exprs[ results[i].nextExpl ], copy( results[i].env ),
+                                                        copy( results[i].need ), copy( results[i].have ),
+                                                        copy( results[i].open ), nextArg, 0, Cost::zero, nextExpl,
+                                                        results[i].explAlt );
+
+                                                continue;
+                                        }
+
+                                        // finish result when out of arguments
+                                        if ( nextArg >= args.size() ) {
+                                                validateFunctionCandidate( func, results[i], results, out );
+
+                                                continue;
+                                        }
+
+                                        // add each possible next argument
+                                        for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
+                                                const ExplodedArg & expl = args[nextArg][j];
+
+                                                // fresh copies of parent parameters for this iteration
+                                                ast::TypeEnvironment env = results[i].env;
+                                                ast::OpenVarSet open = results[i].open;
+
+                                                env.addActual( expl.env, open );
+
+                                                // skip empty tuple arguments by (nearly) cloning parent into next gen
+                                                if ( expl.exprs.empty() ) {
+                                                        results.emplace_back(
+                                                                results[i], std::move( env ), copy( results[i].need ),
+                                                                copy( results[i].have ), std::move( open ), nextArg + 1,
+                                                                expl.cost );
+
+                                                        continue;
+                                                }
+
+                                                // add new result
+                                                results.emplace_back(
+                                                        i, expl.exprs.front(), std::move( env ), copy( results[i].need ),
+                                                        copy( results[i].have ), std::move( open ), nextArg + 1, 0, expl.cost,
+                                                        expl.exprs.size() == 1 ? 0 : 1, j );
+                                        }
+                                }
+
+                                genStart = genEnd;
+                        } while( genEnd != results.size() );
+                } else {
+                        // filter out the results that don't use all the arguments
+                        for ( std::size_t i = genStart; i < results.size(); ++i ) {
+                                ArgPack & result = results[i];
+                                if ( ! result.hasExpl() && result.nextArg >= args.size() ) {
+                                        validateFunctionCandidate( func, result, results, out );
+                                }
+                        }
+                }
+        }
+
+        /// Adds implicit struct-conversions to the alternative list
+        void Finder::addAnonConversions( const CandidateRef & cand ) {
+                // adds anonymous member interpretations whenever an aggregate value type is seen.
+                // it's okay for the aggregate expression to have reference type -- cast it to the
+                // base type to treat the aggregate as the referenced value
+                ast::ptr< ast::Expr > aggrExpr( cand->expr );
+                ast::ptr< ast::Type > & aggrType = aggrExpr.get_and_mutate()->result;
+                cand->env.apply( aggrType );
+
+                if ( aggrType.as< ast::ReferenceType >() ) {
+                        aggrExpr = new ast::CastExpr{ aggrExpr, aggrType->stripReferences() };
+                }
+
+                if ( auto structInst = aggrExpr->result.as< ast::StructInstType >() ) {
+                        addAggMembers( structInst, aggrExpr, *cand, Cost::safe, "" );
+                } else if ( auto unionInst = aggrExpr->result.as< ast::UnionInstType >() ) {
+                        addAggMembers( unionInst, aggrExpr, *cand, Cost::safe, "" );
+                }
+        }
+
+        /// Adds aggregate member interpretations
+        void Finder::addAggMembers(
+                const ast::BaseInstType * aggrInst, const ast::Expr * expr,
+                const Candidate & cand, const Cost & addedCost, const std::string & name
+        ) {
+                for ( const ast::Decl * decl : aggrInst->lookup( name ) ) {
+                        auto dwt = strict_dynamic_cast< const ast::DeclWithType * >( decl );
+                        CandidateRef newCand = std::make_shared<Candidate>(
+                                cand, new ast::MemberExpr{ expr->location, dwt, expr }, addedCost );
+                        // add anonymous member interpretations whenever an aggregate value type is seen
+                        // as a member expression
+                        addAnonConversions( newCand );
+                        candidates.emplace_back( std::move( newCand ) );
+                }
+        }
+
+        /// Adds tuple member interpretations
+        void Finder::addTupleMembers(
+                const ast::TupleType * tupleType, const ast::Expr * expr, const Candidate & cand,
+                const Cost & addedCost, const ast::Expr * member
+        ) {
+                if ( auto constantExpr = dynamic_cast< const ast::ConstantExpr * >( member ) ) {
+                        // get the value of the constant expression as an int, must be between 0 and the
+                        // length of the tuple to have meaning
+                        long long val = constantExpr->intValue();
+                        if ( val >= 0 && (unsigned long long)val < tupleType->size() ) {
+                                addCandidate(
+                                        cand, new ast::TupleIndexExpr{ expr->location, expr, (unsigned)val },
+                                        addedCost );
+                        }
+                }
+        }
+
+        void Finder::postvisit( const ast::UntypedExpr * untypedExpr ) {
+                std::vector< CandidateFinder > argCandidates =
+                        selfFinder.findSubExprs( untypedExpr->args );
+
+                // take care of possible tuple assignments
+                // if not tuple assignment, handled as normal function call
+                Tuples::handleTupleAssignment( selfFinder, untypedExpr, argCandidates );
+
+                CandidateFinder funcFinder( context, tenv );
+                if (auto nameExpr = untypedExpr->func.as<ast::NameExpr>()) {
+                        auto kind = ast::SymbolTable::getSpecialFunctionKind(nameExpr->name);
+                        if (kind != ast::SymbolTable::SpecialFunctionKind::NUMBER_OF_KINDS) {
+                                assertf(!argCandidates.empty(), "special function call without argument");
+                                for (auto & firstArgCand: argCandidates[0]) {
+                                        ast::ptr<ast::Type> argType = firstArgCand->expr->result;
+                                        firstArgCand->env.apply(argType);
+                                        // strip references
+                                        // xxx - is this correct?
+                                        while (argType.as<ast::ReferenceType>()) argType = argType.as<ast::ReferenceType>()->base;
+
+                                        // convert 1-tuple to plain type
+                                        if (auto tuple = argType.as<ast::TupleType>()) {
+                                                if (tuple->size() == 1) {
+                                                        argType = tuple->types[0];
+                                                }
+                                        }
+
+                                        // if argType is an unbound type parameter, all special functions need to be searched.
+                                        if (isUnboundType(argType)) {
+                                                funcFinder.otypeKeys.clear();
+                                                break;
+                                        }
+
+                                        if (argType.as<ast::PointerType>()) funcFinder.otypeKeys.insert(Mangle::Encoding::pointer);                                             
+                                        // else if (const ast::EnumInstType * enumInst = argType.as<ast::EnumInstType>()) {
+                                        //      const ast::EnumDecl * enumDecl = enumInst->base; // Here
+                                        //      if ( const ast::Type* enumType = enumDecl->base ) {
+                                        //              // instance of enum (T) is a instance of type (T)
+                                        //              funcFinder.otypeKeys.insert(Mangle::mangle(enumType, Mangle::NoGenericParams | Mangle::Type));
+                                        //      } else {
+                                        //              // instance of an untyped enum is techically int
+                                        //              funcFinder.otypeKeys.insert(Mangle::mangle(enumDecl, Mangle::NoGenericParams | Mangle::Type));
+                                        //      }
+                                        // }
+                                        else funcFinder.otypeKeys.insert(Mangle::mangle(argType, Mangle::NoGenericParams | Mangle::Type));
+                                }
+                        }
+                }
+                // if candidates are already produced, do not fail
+                // xxx - is it possible that handleTupleAssignment and main finder both produce candidates?
+                // this means there exists ctor/assign functions with a tuple as first parameter.
+                ResolvMode mode = {
+                        true, // adjust
+                        !untypedExpr->func.as<ast::NameExpr>(), // prune if not calling by name
+                        selfFinder.candidates.empty() // failfast if other options are not found
+                };
+                funcFinder.find( untypedExpr->func, mode );
+                // short-circuit if no candidates
+                // if ( funcFinder.candidates.empty() ) return;
+
+                reason.code = NoMatch;
+
+                // find function operators
+                ast::ptr< ast::Expr > opExpr = new ast::NameExpr{ untypedExpr->location, "?()" }; // ??? why not ?{}
+                CandidateFinder opFinder( context, tenv );
+                // okay if there aren't any function operations
+                opFinder.find( opExpr, ResolvMode::withoutFailFast() );
+                PRINT(
+                        std::cerr << "known function ops:" << std::endl;
+                        print( std::cerr, opFinder.candidates, 1 );
+                )
+
+                // pre-explode arguments
+                ExplodedArgs_new argExpansions;
+                for ( const CandidateFinder & args : argCandidates ) {
+                        argExpansions.emplace_back();
+                        auto & argE = argExpansions.back();
+                        for ( const CandidateRef & arg : args ) { argE.emplace_back( *arg, symtab ); }
+                }
+
+                // Find function matches
+                CandidateList found;
+                SemanticErrorException errors;
+                for ( CandidateRef & func : funcFinder ) {
+                        try {
+                                PRINT(
+                                        std::cerr << "working on alternative:" << std::endl;
+                                        print( std::cerr, *func, 2 );
+                                )
+
+                                // check if the type is a pointer to function
+                                const ast::Type * funcResult = func->expr->result->stripReferences();
+                                if ( auto pointer = dynamic_cast< const ast::PointerType * >( funcResult ) ) {
+                                        if ( auto function = pointer->base.as< ast::FunctionType >() ) {
+                                                CandidateRef newFunc{ new Candidate{ *func } };
+                                                newFunc->expr =
+                                                        referenceToRvalueConversion( newFunc->expr, newFunc->cost );
+                                                makeFunctionCandidates( untypedExpr->location,
+                                                        newFunc, function, argExpansions, found );
+                                        }
+                                } else if (
+                                        auto inst = dynamic_cast< const ast::TypeInstType * >( funcResult )
+                                ) {
+                                        if ( const ast::EqvClass * clz = func->env.lookup( *inst ) ) {
+                                                if ( auto function = clz->bound.as< ast::FunctionType >() ) {
+                                                        CandidateRef newFunc{ new Candidate{ *func } };
+                                                        newFunc->expr =
+                                                                referenceToRvalueConversion( newFunc->expr, newFunc->cost );
+                                                        makeFunctionCandidates( untypedExpr->location,
+                                                                newFunc, function, argExpansions, found );
+                                                }
+                                        }
+                                }
+                        } catch ( SemanticErrorException & e ) { errors.append( e ); }
+                }
+
+                // Find matches on function operators `?()`
+                if ( ! opFinder.candidates.empty() ) {
+                        // add exploded function alternatives to front of argument list
+                        std::vector< ExplodedArg > funcE;
+                        funcE.reserve( funcFinder.candidates.size() );
+                        for ( const CandidateRef & func : funcFinder ) {
+                                funcE.emplace_back( *func, symtab );
+                        }
+                        argExpansions.emplace_front( std::move( funcE ) );
+
+                        for ( const CandidateRef & op : opFinder ) {
+                                try {
+                                        // check if type is pointer-to-function
+                                        const ast::Type * opResult = op->expr->result->stripReferences();
+                                        if ( auto pointer = dynamic_cast< const ast::PointerType * >( opResult ) ) {
+                                                if ( auto function = pointer->base.as< ast::FunctionType >() ) {
+                                                        CandidateRef newOp{ new Candidate{ *op} };
+                                                        newOp->expr =
+                                                                referenceToRvalueConversion( newOp->expr, newOp->cost );
+                                                        makeFunctionCandidates( untypedExpr->location,
+                                                                newOp, function, argExpansions, found );
+                                                }
+                                        }
+                                } catch ( SemanticErrorException & e ) { errors.append( e ); }
+                        }
+                }
+
+                // Implement SFINAE; resolution errors are only errors if there aren't any non-error
+                // candidates
+                if ( found.empty() && ! errors.isEmpty() ) { throw errors; }
+
+                // Compute conversion costs
+                for ( CandidateRef & withFunc : found ) {
+                        Cost cvtCost = computeApplicationConversionCost( withFunc, symtab );
+
+                        PRINT(
+                                auto appExpr = withFunc->expr.strict_as< ast::ApplicationExpr >();
+                                auto pointer = appExpr->func->result.strict_as< ast::PointerType >();
+                                auto function = pointer->base.strict_as< ast::FunctionType >();
+
+                                std::cerr << "Case +++++++++++++ " << appExpr->func << std::endl;
+                                std::cerr << "parameters are:" << std::endl;
+                                ast::printAll( std::cerr, function->params, 2 );
+                                std::cerr << "arguments are:" << std::endl;
+                                ast::printAll( std::cerr, appExpr->args, 2 );
+                                std::cerr << "bindings are:" << std::endl;
+                                ast::print( std::cerr, withFunc->env, 2 );
+                                std::cerr << "cost is: " << withFunc->cost << std::endl;
+                                std::cerr << "cost of conversion is:" << cvtCost << std::endl;
+                        )
+
+                        if ( cvtCost != Cost::infinity ) {
+                                withFunc->cvtCost = cvtCost;
+                                candidates.emplace_back( std::move( withFunc ) );
+                        }
+                }
+                found = std::move( candidates );
+
+                // use a new list so that candidates are not examined by addAnonConversions twice
+                CandidateList winners = findMinCost( found );
+                promoteCvtCost( winners );
+
+                // function may return a struct/union value, in which case we need to add candidates
+                // for implicit conversions to each of the anonymous members, which must happen after
+                // `findMinCost`, since anon conversions are never the cheapest
+                for ( const CandidateRef & c : winners ) {
+                        addAnonConversions( c );
+                }
+                spliceBegin( candidates, winners );
+
+                if ( candidates.empty() && targetType && ! targetType->isVoid() ) {
+                        // If resolution is unsuccessful with a target type, try again without, since it
+                        // will sometimes succeed when it wouldn't with a target type binding.
+                        // For example:
+                        //   forall( otype T ) T & ?[]( T *, ptrdiff_t );
+                        //   const char * x = "hello world";
+                        //   unsigned char ch = x[0];
+                        // Fails with simple return type binding (xxx -- check this!) as follows:
+                        // * T is bound to unsigned char
+                        // * (x: const char *) is unified with unsigned char *, which fails
+                        // xxx -- fix this better
+                        targetType = nullptr;
+                        postvisit( untypedExpr );
+                }
+        }
+
+        void Finder::postvisit( const ast::AddressExpr * addressExpr ) {
+                CandidateFinder finder( context, tenv );
+                finder.find( addressExpr->arg );
+
+                if ( finder.candidates.empty() ) return;
+
+                reason.code = NoMatch;
+
+                for ( CandidateRef & r : finder.candidates ) {
+                        if ( ! isLvalue( r->expr ) ) continue;
+                        addCandidate( *r, new ast::AddressExpr{ addressExpr->location, r->expr } );
+                }
+        }
+
+        void Finder::postvisit( const ast::LabelAddressExpr * labelExpr ) {
+                addCandidate( labelExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::CastExpr * castExpr ) {
+                ast::ptr< ast::Type > toType = castExpr->result;
+                assert( toType );
+                toType = resolveTypeof( toType, context );
+                toType = adjustExprType( toType, tenv, symtab );
+
+                CandidateFinder finder( context, tenv, toType );
+                finder.find( castExpr->arg, ResolvMode::withAdjustment() );
+
+                if ( !finder.candidates.empty() ) reason.code = NoMatch;
+
+                CandidateList matches;
+                for ( CandidateRef & cand : finder.candidates ) {
+                        ast::AssertionSet need( cand->need.begin(), cand->need.end() ), have;
+                        ast::OpenVarSet open( cand->open );
+
+                        cand->env.extractOpenVars( open );
+
+                        // It is possible that a cast can throw away some values in a multiply-valued
+                        // expression, e.g. cast-to-void, one value to zero. Figure out the prefix of the
+                        // subexpression results that are cast directly. The candidate is invalid if it
+                        // has fewer results than there are types to cast to.
+                        int discardedValues = cand->expr->result->size() - toType->size();
+                        if ( discardedValues < 0 ) continue;
+
+                        // unification run for side-effects
+                        unify( toType, cand->expr->result, cand->env, need, have, open, symtab );
+                        Cost thisCost =
+                                (castExpr->isGenerated == ast::GeneratedFlag::GeneratedCast)
+                                        ? conversionCost( cand->expr->result, toType, cand->expr->get_lvalue(), symtab, cand->env )
+                                        : castCost( cand->expr->result, toType, cand->expr->get_lvalue(), symtab, cand->env );
+
+                        PRINT(
+                                std::cerr << "working on cast with result: " << toType << std::endl;
+                                std::cerr << "and expr type: " << cand->expr->result << std::endl;
+                                std::cerr << "env: " << cand->env << std::endl;
+                        )
+                        if ( thisCost != Cost::infinity ) {
+                                PRINT(
+                                        std::cerr << "has finite cost." << std::endl;
+                                )
+                                // count one safe conversion for each value that is thrown away
+                                thisCost.incSafe( discardedValues );
+                                CandidateRef newCand = std::make_shared<Candidate>(
+                                        restructureCast( cand->expr, toType, castExpr->isGenerated ),
+                                        copy( cand->env ), std::move( open ), std::move( need ), cand->cost,
+                                        cand->cost + thisCost );
+                                inferParameters( newCand, matches );
+                        }
+                }
+
+                // select first on argument cost, then conversion cost
+                CandidateList minArgCost = findMinCost( matches );
+                promoteCvtCost( minArgCost );
+                candidates = findMinCost( minArgCost );
+        }
+
+        void Finder::postvisit( const ast::VirtualCastExpr * castExpr ) {
+                assertf( castExpr->result, "Implicit virtual cast targets not yet supported." );
+                CandidateFinder finder( context, tenv );
+                // don't prune here, all alternatives guaranteed to have same type
+                finder.find( castExpr->arg, ResolvMode::withoutPrune() );
+                for ( CandidateRef & r : finder.candidates ) {
+                        addCandidate(
+                                *r,
+                                new ast::VirtualCastExpr{ castExpr->location, r->expr, castExpr->result } );
+                }
+        }
+
+        void Finder::postvisit( const ast::KeywordCastExpr * castExpr ) {
+                const auto & loc = castExpr->location;
+                assertf( castExpr->result, "Cast target should have been set in Validate." );
+                auto ref = castExpr->result.strict_as<ast::ReferenceType>();
+                auto inst = ref->base.strict_as<ast::StructInstType>();
+                auto target = inst->base.get();
+
+                CandidateFinder finder( context, tenv );
+
+                auto pick_alternatives = [target, this](CandidateList & found, bool expect_ref) {
+                        for (auto & cand : found) {
+                                const ast::Type * expr = cand->expr->result.get();
+                                if (expect_ref) {
+                                        auto res = dynamic_cast<const ast::ReferenceType*>(expr);
+                                        if (!res) { continue; }
+                                        expr = res->base.get();
+                                }
+
+                                if (auto insttype = dynamic_cast<const ast::TypeInstType*>(expr)) {
+                                        auto td = cand->env.lookup(*insttype);
+                                        if (!td) { continue; }
+                                        expr = td->bound.get();
+                                }
+
+                                if (auto base = dynamic_cast<const ast::StructInstType*>(expr)) {
+                                        if (base->base == target) {
+                                                candidates.push_back( std::move(cand) );
+                                                reason.code = NoReason;
+                                        }
+                                }
+                        }
+                };
+
+                try {
+                        // Attempt 1 : turn (thread&)X into (thread$&)X.__thrd
+                        // Clone is purely for memory management
+                        std::unique_ptr<const ast::Expr> tech1 { new ast::UntypedMemberExpr(loc, new ast::NameExpr(loc, castExpr->concrete_target.field), castExpr->arg) };
+
+                        // don't prune here, since it's guaranteed all alternatives will have the same type
+                        finder.find( tech1.get(), ResolvMode::withoutPrune() );
+                        pick_alternatives(finder.candidates, false);
+
+                        return;
+                } catch(SemanticErrorException & ) {}
+
+                // Fallback : turn (thread&)X into (thread$&)get_thread(X)
+                std::unique_ptr<const ast::Expr> fallback { ast::UntypedExpr::createDeref(loc,  new ast::UntypedExpr(loc, new ast::NameExpr(loc, castExpr->concrete_target.getter), { castExpr->arg })) };
+                // don't prune here, since it's guaranteed all alternatives will have the same type
+                finder.find( fallback.get(), ResolvMode::withoutPrune() );
+
+                pick_alternatives(finder.candidates, true);
+
+                // Whatever happens here, we have no more fallbacks
+        }
+
+        void Finder::postvisit( const ast::UntypedMemberExpr * memberExpr ) {
+                CandidateFinder aggFinder( context, tenv );
+                aggFinder.find( memberExpr->aggregate, ResolvMode::withAdjustment() );
+                for ( CandidateRef & agg : aggFinder.candidates ) {
+                        // it's okay for the aggregate expression to have reference type -- cast it to the
+                        // base type to treat the aggregate as the referenced value
+                        Cost addedCost = Cost::zero;
+                        agg->expr = referenceToRvalueConversion( agg->expr, addedCost );
+
+                        // find member of the given type
+                        if ( auto structInst = agg->expr->result.as< ast::StructInstType >() ) {
+                                addAggMembers(
+                                        structInst, agg->expr, *agg, addedCost, getMemberName( memberExpr ) );
+                        } else if ( auto unionInst = agg->expr->result.as< ast::UnionInstType >() ) {
+                                addAggMembers(
+                                        unionInst, agg->expr, *agg, addedCost, getMemberName( memberExpr ) );
+                        } else if ( auto tupleType = agg->expr->result.as< ast::TupleType >() ) {
+                                addTupleMembers( tupleType, agg->expr, *agg, addedCost, memberExpr->member );
+                        }
+                }
+        }
+
+        void Finder::postvisit( const ast::MemberExpr * memberExpr ) {
+                addCandidate( memberExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::NameExpr * nameExpr ) {
+                std::vector< ast::SymbolTable::IdData > declList;
+                if (!selfFinder.otypeKeys.empty()) {
+                        auto kind = ast::SymbolTable::getSpecialFunctionKind(nameExpr->name);
+                        assertf(kind != ast::SymbolTable::SpecialFunctionKind::NUMBER_OF_KINDS, "special lookup with non-special target: %s", nameExpr->name.c_str());
+
+                        for (auto & otypeKey: selfFinder.otypeKeys) {
+                                auto result = symtab.specialLookupId(kind, otypeKey);
+                                declList.insert(declList.end(), std::make_move_iterator(result.begin()), std::make_move_iterator(result.end()));
+                        }
+                } else {
+                        declList = symtab.lookupId( nameExpr->name );
+                }
+                PRINT( std::cerr << "nameExpr is " << nameExpr->name << std::endl; )
+
+                if ( declList.empty() ) return;
+
+                reason.code = NoMatch;
+
+                for ( auto & data : declList ) {
+                        Cost cost = Cost::zero;
+                        ast::Expr * newExpr = data.combine( nameExpr->location, cost );
+
+                        CandidateRef newCand = std::make_shared<Candidate>(
+                                newExpr, copy( tenv ), ast::OpenVarSet{}, ast::AssertionSet{}, Cost::zero,
+                                cost );
+
+                        if (newCand->expr->env) {
+                                newCand->env.add(*newCand->expr->env);
+                                auto mutExpr = newCand->expr.get_and_mutate();
+                                mutExpr->env  = nullptr;
+                                newCand->expr = mutExpr;
+                        }
+
+                        PRINT(
+                                std::cerr << "decl is ";
+                                ast::print( std::cerr, data.id );
+                                std::cerr << std::endl;
+                                std::cerr << "newExpr is ";
+                                ast::print( std::cerr, newExpr );
+                                std::cerr << std::endl;
+                        )
+                        newCand->expr = ast::mutate_field(
+                                newCand->expr.get(), &ast::Expr::result,
+                                renameTyVars( newCand->expr->result ) );
+                        // add anonymous member interpretations whenever an aggregate value type is seen
+                        // as a name expression
+                        addAnonConversions( newCand );
+                        candidates.emplace_back( std::move( newCand ) );
+                }
+        }
+
+        void Finder::postvisit( const ast::VariableExpr * variableExpr ) {
+                // not sufficient to just pass `variableExpr` here, type might have changed since
+                // creation
+                addCandidate(
+                        new ast::VariableExpr{ variableExpr->location, variableExpr->var }, tenv );
+        }
+
+        void Finder::postvisit( const ast::ConstantExpr * constantExpr ) {
+                addCandidate( constantExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::SizeofExpr * sizeofExpr ) {
+                if ( sizeofExpr->type ) {
+                        addCandidate(
+                                new ast::SizeofExpr{
+                                        sizeofExpr->location, resolveTypeof( sizeofExpr->type, context ) },
+                                tenv );
+                } else {
+                        // find all candidates for the argument to sizeof
+                        CandidateFinder finder( context, tenv );
+                        finder.find( sizeofExpr->expr );
+                        // find the lowest-cost candidate, otherwise ambiguous
+                        CandidateList winners = findMinCost( finder.candidates );
+                        if ( winners.size() != 1 ) {
+                                SemanticError(
+                                        sizeofExpr->expr.get(), "Ambiguous expression in sizeof operand: " );
+                        }
+                        // return the lowest-cost candidate
+                        CandidateRef & choice = winners.front();
+                        choice->expr = referenceToRvalueConversion( choice->expr, choice->cost );
+                        choice->cost = Cost::zero;
+                        addCandidate( *choice, new ast::SizeofExpr{ sizeofExpr->location, choice->expr } );
+                }
+        }
+
+        void Finder::postvisit( const ast::AlignofExpr * alignofExpr ) {
+                if ( alignofExpr->type ) {
+                        addCandidate(
+                                new ast::AlignofExpr{
+                                        alignofExpr->location, resolveTypeof( alignofExpr->type, context ) },
+                                tenv );
+                } else {
+                        // find all candidates for the argument to alignof
+                        CandidateFinder finder( context, tenv );
+                        finder.find( alignofExpr->expr );
+                        // find the lowest-cost candidate, otherwise ambiguous
+                        CandidateList winners = findMinCost( finder.candidates );
+                        if ( winners.size() != 1 ) {
+                                SemanticError(
+                                        alignofExpr->expr.get(), "Ambiguous expression in alignof operand: " );
+                        }
+                        // return the lowest-cost candidate
+                        CandidateRef & choice = winners.front();
+                        choice->expr = referenceToRvalueConversion( choice->expr, choice->cost );
+                        choice->cost = Cost::zero;
+                        addCandidate(
+                                *choice, new ast::AlignofExpr{ alignofExpr->location, choice->expr } );
+                }
+        }
+
+        void Finder::postvisit( const ast::UntypedOffsetofExpr * offsetofExpr ) {
+                const ast::BaseInstType * aggInst;
+                if (( aggInst = offsetofExpr->type.as< ast::StructInstType >() )) ;
+                else if (( aggInst = offsetofExpr->type.as< ast::UnionInstType >() )) ;
+                else return;
+
+                for ( const ast::Decl * member : aggInst->lookup( offsetofExpr->member ) ) {
+                        auto dwt = strict_dynamic_cast< const ast::DeclWithType * >( member );
+                        addCandidate(
+                                new ast::OffsetofExpr{ offsetofExpr->location, aggInst, dwt }, tenv );
+                }
+        }
+
+        void Finder::postvisit( const ast::OffsetofExpr * offsetofExpr ) {
+                addCandidate( offsetofExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::OffsetPackExpr * offsetPackExpr ) {
+                addCandidate( offsetPackExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::LogicalExpr * logicalExpr ) {
+                CandidateFinder finder1( context, tenv );
+                finder1.find( logicalExpr->arg1, ResolvMode::withAdjustment() );
+                if ( finder1.candidates.empty() ) return;
+
+                CandidateFinder finder2( context, tenv );
+                finder2.find( logicalExpr->arg2, ResolvMode::withAdjustment() );
+                if ( finder2.candidates.empty() ) return;
+
+                reason.code = NoMatch;
+
+                for ( const CandidateRef & r1 : finder1.candidates ) {
+                        for ( const CandidateRef & r2 : finder2.candidates ) {
+                                ast::TypeEnvironment env{ r1->env };
+                                env.simpleCombine( r2->env );
+                                ast::OpenVarSet open{ r1->open };
+                                mergeOpenVars( open, r2->open );
+                                ast::AssertionSet need;
+                                mergeAssertionSet( need, r1->need );
+                                mergeAssertionSet( need, r2->need );
+
+                                addCandidate(
+                                        new ast::LogicalExpr{
+                                                logicalExpr->location, r1->expr, r2->expr, logicalExpr->isAnd },
+                                        std::move( env ), std::move( open ), std::move( need ), r1->cost + r2->cost );
+                        }
+                }
+        }
+
+        void Finder::postvisit( const ast::ConditionalExpr * conditionalExpr ) {
+                // candidates for condition
+                CandidateFinder finder1( context, tenv );
+                finder1.find( conditionalExpr->arg1, ResolvMode::withAdjustment() );
+                if ( finder1.candidates.empty() ) return;
+
+                // candidates for true result
+                CandidateFinder finder2( context, tenv );
+                finder2.find( conditionalExpr->arg2, ResolvMode::withAdjustment() );
+                if ( finder2.candidates.empty() ) return;
+
+                // candidates for false result
+                CandidateFinder finder3( context, tenv );
+                finder3.find( conditionalExpr->arg3, ResolvMode::withAdjustment() );
+                if ( finder3.candidates.empty() ) return;
+
+                reason.code = NoMatch;
+
+                for ( const CandidateRef & r1 : finder1.candidates ) {
+                        for ( const CandidateRef & r2 : finder2.candidates ) {
+                                for ( const CandidateRef & r3 : finder3.candidates ) {
+                                        ast::TypeEnvironment env{ r1->env };
+                                        env.simpleCombine( r2->env );
+                                        env.simpleCombine( r3->env );
+                                        ast::OpenVarSet open{ r1->open };
+                                        mergeOpenVars( open, r2->open );
+                                        mergeOpenVars( open, r3->open );
+                                        ast::AssertionSet need;
+                                        mergeAssertionSet( need, r1->need );
+                                        mergeAssertionSet( need, r2->need );
+                                        mergeAssertionSet( need, r3->need );
+                                        ast::AssertionSet have;
+
+                                        // unify true and false results, then infer parameters to produce new
+                                        // candidates
+                                        ast::ptr< ast::Type > common;
+                                        if (
+                                                unify(
+                                                        r2->expr->result, r3->expr->result, env, need, have, open, symtab,
+                                                        common )
+                                        ) {
+                                                // generate typed expression
+                                                ast::ConditionalExpr * newExpr = new ast::ConditionalExpr{
+                                                        conditionalExpr->location, r1->expr, r2->expr, r3->expr };
+                                                newExpr->result = common ? common : r2->expr->result;
+                                                // convert both options to result type
+                                                Cost cost = r1->cost + r2->cost + r3->cost;
+                                                newExpr->arg2 = computeExpressionConversionCost(
+                                                        newExpr->arg2, newExpr->result, symtab, env, cost );
+                                                newExpr->arg3 = computeExpressionConversionCost(
+                                                        newExpr->arg3, newExpr->result, symtab, env, cost );
+                                                // output candidate
+                                                CandidateRef newCand = std::make_shared<Candidate>(
+                                                        newExpr, std::move( env ), std::move( open ), std::move( need ), cost );
+                                                inferParameters( newCand, candidates );
+                                        }
+                                }
+                        }
+                }
+        }
+
+        void Finder::postvisit( const ast::CommaExpr * commaExpr ) {
+                ast::TypeEnvironment env{ tenv };
+                ast::ptr< ast::Expr > arg1 = resolveInVoidContext( commaExpr->arg1, context, env );
+
+                CandidateFinder finder2( context, env );
+                finder2.find( commaExpr->arg2, ResolvMode::withAdjustment() );
+
+                for ( const CandidateRef & r2 : finder2.candidates ) {
+                        addCandidate( *r2, new ast::CommaExpr{ commaExpr->location, arg1, r2->expr } );
+                }
+        }
+
+        void Finder::postvisit( const ast::ImplicitCopyCtorExpr * ctorExpr ) {
+                addCandidate( ctorExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::ConstructorExpr * ctorExpr ) {
+                CandidateFinder finder( context, tenv );
+                finder.find( ctorExpr->callExpr, ResolvMode::withoutPrune() );
+                for ( CandidateRef & r : finder.candidates ) {
+                        addCandidate( *r, new ast::ConstructorExpr{ ctorExpr->location, r->expr } );
+                }
+        }
+
+        void Finder::postvisit( const ast::RangeExpr * rangeExpr ) {
+                // resolve low and high, accept candidates where low and high types unify
+                CandidateFinder finder1( context, tenv );
+                finder1.find( rangeExpr->low, ResolvMode::withAdjustment() );
+                if ( finder1.candidates.empty() ) return;
+
+                CandidateFinder finder2( context, tenv );
+                finder2.find( rangeExpr->high, ResolvMode::withAdjustment() );
+                if ( finder2.candidates.empty() ) return;
+
+                reason.code = NoMatch;
+
+                for ( const CandidateRef & r1 : finder1.candidates ) {
+                        for ( const CandidateRef & r2 : finder2.candidates ) {
+                                ast::TypeEnvironment env{ r1->env };
+                                env.simpleCombine( r2->env );
+                                ast::OpenVarSet open{ r1->open };
+                                mergeOpenVars( open, r2->open );
+                                ast::AssertionSet need;
+                                mergeAssertionSet( need, r1->need );
+                                mergeAssertionSet( need, r2->need );
+                                ast::AssertionSet have;
+
+                                ast::ptr< ast::Type > common;
+                                if (
+                                        unify(
+                                                r1->expr->result, r2->expr->result, env, need, have, open, symtab,
+                                                common )
+                                ) {
+                                        // generate new expression
+                                        ast::RangeExpr * newExpr =
+                                                new ast::RangeExpr{ rangeExpr->location, r1->expr, r2->expr };
+                                        newExpr->result = common ? common : r1->expr->result;
+                                        // add candidate
+                                        CandidateRef newCand = std::make_shared<Candidate>(
+                                                newExpr, std::move( env ), std::move( open ), std::move( need ),
+                                                r1->cost + r2->cost );
+                                        inferParameters( newCand, candidates );
+                                }
+                        }
+                }
+        }
+
+        void Finder::postvisit( const ast::UntypedTupleExpr * tupleExpr ) {
+                std::vector< CandidateFinder > subCandidates =
+                        selfFinder.findSubExprs( tupleExpr->exprs );
+                std::vector< CandidateList > possibilities;
+                combos( subCandidates.begin(), subCandidates.end(), back_inserter( possibilities ) );
+
+                for ( const CandidateList & subs : possibilities ) {
+                        std::vector< ast::ptr< ast::Expr > > exprs;
+                        exprs.reserve( subs.size() );
+                        for ( const CandidateRef & sub : subs ) { exprs.emplace_back( sub->expr ); }
+
+                        ast::TypeEnvironment env;
+                        ast::OpenVarSet open;
+                        ast::AssertionSet need;
+                        for ( const CandidateRef & sub : subs ) {
+                                env.simpleCombine( sub->env );
+                                mergeOpenVars( open, sub->open );
+                                mergeAssertionSet( need, sub->need );
+                        }
+
+                        addCandidate(
+                                new ast::TupleExpr{ tupleExpr->location, std::move( exprs ) },
+                                std::move( env ), std::move( open ), std::move( need ), sumCost( subs ) );
+                }
+        }
+
+        void Finder::postvisit( const ast::TupleExpr * tupleExpr ) {
+                addCandidate( tupleExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::TupleIndexExpr * tupleExpr ) {
+                addCandidate( tupleExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::TupleAssignExpr * tupleExpr ) {
+                addCandidate( tupleExpr, tenv );
+        }
+
+        void Finder::postvisit( const ast::UniqueExpr * unqExpr ) {
+                CandidateFinder finder( context, tenv );
+                finder.find( unqExpr->expr, ResolvMode::withAdjustment() );
+                for ( CandidateRef & r : finder.candidates ) {
+                        // ensure that the the id is passed on so that the expressions are "linked"
+                        addCandidate( *r, new ast::UniqueExpr{ unqExpr->location, r->expr, unqExpr->id } );
+                }
+        }
+
+        void Finder::postvisit( const ast::StmtExpr * stmtExpr ) {
+                addCandidate( resolveStmtExpr( stmtExpr, context ), tenv );
+        }
+
+        void Finder::postvisit( const ast::UntypedInitExpr * initExpr ) {
+                // handle each option like a cast
+                CandidateList matches;
+                PRINT(
+                        std::cerr << "untyped init expr: " << initExpr << std::endl;
+                )
+                // O(n^2) checks of d-types with e-types
+                for ( const ast::InitAlternative & initAlt : initExpr->initAlts ) {
+                        // calculate target type
+                        const ast::Type * toType = resolveTypeof( initAlt.type, context );
+                        toType = adjustExprType( toType, tenv, symtab );
+                        // The call to find must occur inside this loop, otherwise polymorphic return
+                        // types are not bound to the initialization type, since return type variables are
+                        // only open for the duration of resolving the UntypedExpr.
+                        CandidateFinder finder( context, tenv, toType );
+                        finder.find( initExpr->expr, ResolvMode::withAdjustment() );
+                        for ( CandidateRef & cand : finder.candidates ) {
+                                if (reason.code == NotFound) reason.code = NoMatch;
+
+                                ast::TypeEnvironment env{ cand->env };
+                                ast::AssertionSet need( cand->need.begin(), cand->need.end() ), have;
+                                ast::OpenVarSet open{ cand->open };
+
+                                PRINT(
+                                        std::cerr << "  @ " << toType << " " << initAlt.designation << std::endl;
+                                )
+
+                                // It is possible that a cast can throw away some values in a multiply-valued
+                                // expression, e.g. cast-to-void, one value to zero. Figure out the prefix of
+                                // the subexpression results that are cast directly. The candidate is invalid
+                                // if it has fewer results than there are types to cast to.
+                                int discardedValues = cand->expr->result->size() - toType->size();
+                                if ( discardedValues < 0 ) continue;
+
+                                // unification run for side-effects
+                                bool canUnify = unify( toType, cand->expr->result, env, need, have, open, symtab );
+                                (void) canUnify;
+                                Cost thisCost = computeConversionCost( cand->expr->result, toType, cand->expr->get_lvalue(),
+                                        symtab, env );
+                                PRINT(
+                                        Cost legacyCost = castCost( cand->expr->result, toType, cand->expr->get_lvalue(),
+                                                symtab, env );
+                                        std::cerr << "Considering initialization:";
+                                        std::cerr << std::endl << "  FROM: " << cand->expr->result << std::endl;
+                                        std::cerr << std::endl << "  TO: "   << toType             << std::endl;
+                                        std::cerr << std::endl << "  Unification " << (canUnify ? "succeeded" : "failed");
+                                        std::cerr << std::endl << "  Legacy cost " << legacyCost;
+                                        std::cerr << std::endl << "  New cost " << thisCost;
+                                        std::cerr << std::endl;
+                                )
+                                if ( thisCost != Cost::infinity ) {
+                                        // count one safe conversion for each value that is thrown away
+                                        thisCost.incSafe( discardedValues );
+                                        CandidateRef newCand = std::make_shared<Candidate>(
+                                                new ast::InitExpr{
+                                                        initExpr->location, restructureCast( cand->expr, toType ),
+                                                        initAlt.designation },
+                                                std::move(env), std::move( open ), std::move( need ), cand->cost, thisCost );
+                                        inferParameters( newCand, matches );
+                                }
+                        }
+                }
+
+                // select first on argument cost, then conversion cost
+                CandidateList minArgCost = findMinCost( matches );
+                promoteCvtCost( minArgCost );
+                candidates = findMinCost( minArgCost );
+        }
+
+        // size_t Finder::traceId = Stats::Heap::new_stacktrace_id("Finder");
+        /// Prunes a list of candidates down to those that have the minimum conversion cost for a given
+        /// return type. Skips ambiguous candidates.
+
+} // anonymous namespace
+
+bool CandidateFinder::pruneCandidates( CandidateList & candidates, CandidateList & out, std::vector<std::string> & errors ) {
+        struct PruneStruct {
+                CandidateRef candidate;
+                bool ambiguous;
+
+                PruneStruct() = default;
+                PruneStruct( const CandidateRef & c ) : candidate( c ), ambiguous( false ) {}
+        };
+
+        // find lowest-cost candidate for each type
+        std::unordered_map< std::string, PruneStruct > selected;
+        // attempt to skip satisfyAssertions on more expensive alternatives if better options have been found
+        std::sort(candidates.begin(), candidates.end(), [](const CandidateRef & x, const CandidateRef & y){return x->cost < y->cost;});
+        for ( CandidateRef & candidate : candidates ) {
+                std::string mangleName;
+                {
+                        ast::ptr< ast::Type > newType = candidate->expr->result;
+                        assertf(candidate->expr->result, "Result of expression %p for candidate is null", candidate->expr.get());
+                        candidate->env.apply( newType );
+                        mangleName = Mangle::mangle( newType );
+                }
+
+                auto found = selected.find( mangleName );
+                if (found != selected.end() && found->second.candidate->cost < candidate->cost) {
+                        PRINT(
+                                std::cerr << "cost " << candidate->cost << " loses to "
+                                        << found->second.candidate->cost << std::endl;
+                        )
+                        continue;
+                }
+
+                // xxx - when do satisfyAssertions produce more than 1 result?
+                // this should only happen when initial result type contains
+                // unbound type parameters, then it should never be pruned by
+                // the previous step, since renameTyVars guarantees the mangled name
+                // is unique.
+                CandidateList satisfied;
+                bool needRecomputeKey = false;
+                if (candidate->need.empty()) {
+                        satisfied.emplace_back(candidate);
+                }
+                else {
+                        satisfyAssertions(candidate, context.symtab, satisfied, errors);
+                        needRecomputeKey = true;
+                }
+
+                for (auto & newCand : satisfied) {
+                        // recomputes type key, if satisfyAssertions changed it
+                        if (needRecomputeKey)
+                        {
+                                ast::ptr< ast::Type > newType = newCand->expr->result;
+                                assertf(newCand->expr->result, "Result of expression %p for candidate is null", newCand->expr.get());
+                                newCand->env.apply( newType );
+                                mangleName = Mangle::mangle( newType );
+                        }
+                        auto found = selected.find( mangleName );
+                        if ( found != selected.end() ) {
+                                if ( newCand->cost < found->second.candidate->cost ) {
+                                        PRINT(
+                                                std::cerr << "cost " << newCand->cost << " beats "
+                                                        << found->second.candidate->cost << std::endl;
+                                        )
+
+                                        found->second = PruneStruct{ newCand };
+                                } else if ( newCand->cost == found->second.candidate->cost ) {
+                                        // if one of the candidates contains a deleted identifier, can pick the other,
+                                        // since deleted expressions should not be ambiguous if there is another option
+                                        // that is at least as good
+                                        if ( findDeletedExpr( newCand->expr ) ) {
+                                                // do nothing
+                                                PRINT( std::cerr << "candidate is deleted" << std::endl; )
+                                        } else if ( findDeletedExpr( found->second.candidate->expr ) ) {
+                                                PRINT( std::cerr << "current is deleted" << std::endl; )
+                                                found->second = PruneStruct{ newCand };
+                                        } else {
+                                                PRINT( std::cerr << "marking ambiguous" << std::endl; )
+                                                found->second.ambiguous = true;
+                                        }
+                                } else {
+                                        // xxx - can satisfyAssertions increase the cost?
+                                        PRINT(
+                                                std::cerr << "cost " << newCand->cost << " loses to "
+                                                        << found->second.candidate->cost << std::endl;
+                                        )
+                                }
+                        } else {
+                                selected.emplace_hint( found, mangleName, newCand );
+                        }
+                }
+        }
+
+        // report unambiguous min-cost candidates
+        // CandidateList out;
+        for ( auto & target : selected ) {
+                if ( target.second.ambiguous ) continue;
+
+                CandidateRef cand = target.second.candidate;
+
+                ast::ptr< ast::Type > newResult = cand->expr->result;
+                cand->env.applyFree( newResult );
+                cand->expr = ast::mutate_field(
+                        cand->expr.get(), &ast::Expr::result, std::move( newResult ) );
+
+                out.emplace_back( cand );
+        }
+        // if everything is lost in satisfyAssertions, report the error
+        return !selected.empty();
+}
+
+void CandidateFinder::find( const ast::Expr * expr, ResolvMode mode ) {
+        // Find alternatives for expression
+        ast::Pass<Finder> finder{ *this };
+        expr->accept( finder );
+
+        if ( mode.failFast && candidates.empty() ) {
+                switch(finder.core.reason.code) {
+                case Finder::NotFound:
+                        { SemanticError( expr, "No alternatives for expression " ); break; }
+                case Finder::NoMatch:
+                        { SemanticError( expr, "Invalid application of existing declaration(s) in expression " ); break; }
+                case Finder::ArgsToFew:
+                case Finder::ArgsToMany:
+                case Finder::RetsToFew:
+                case Finder::RetsToMany:
+                case Finder::NoReason:
+                default:
+                        { SemanticError( expr->location, "No reasonable alternatives for expression : reasons unkown" ); }
+                }
+        }
+
+        /*
+        if ( mode.satisfyAssns || mode.prune ) {
+                // trim candidates to just those where the assertions are satisfiable
+                // - necessary pre-requisite to pruning
+                CandidateList satisfied;
+                std::vector< std::string > errors;
+                for ( CandidateRef & candidate : candidates ) {
+                        satisfyAssertions( candidate, localSyms, satisfied, errors );
+                }
+
+                // fail early if none such
+                if ( mode.failFast && satisfied.empty() ) {
+                        std::ostringstream stream;
+                        stream << "No alternatives with satisfiable assertions for " << expr << "\n";
+                        for ( const auto& err : errors ) {
+                                stream << err;
+                        }
+                        SemanticError( expr->location, stream.str() );
+                }
+
+                // reset candidates
+                candidates = move( satisfied );
+        }
+        */
+
+        if ( mode.prune ) {
+                // trim candidates to single best one
+                PRINT(
+                        std::cerr << "alternatives before prune:" << std::endl;
+                        print( std::cerr, candidates );
+                )
+
+                CandidateList pruned;
+                std::vector<std::string> errors;
+                bool found = pruneCandidates( candidates, pruned, errors );
+
+                if ( mode.failFast && pruned.empty() ) {
+                        std::ostringstream stream;
+                        if (found) {
+                                CandidateList winners = findMinCost( candidates );
+                                stream << "Cannot choose between " << winners.size() << " alternatives for "
+                                        "expression\n";
+                                ast::print( stream, expr );
+                                stream << " Alternatives are:\n";
+                                print( stream, winners, 1 );
+                                SemanticError( expr->location, stream.str() );
+                        }
+                        else {
+                                stream << "No alternatives with satisfiable assertions for " << expr << "\n";
+                                for ( const auto& err : errors ) {
+                                        stream << err;
+                                }
+                                SemanticError( expr->location, stream.str() );
+                        }
+                }
+
+                auto oldsize = candidates.size();
+                candidates = std::move( pruned );
+
+                PRINT(
+                        std::cerr << "there are " << oldsize << " alternatives before elimination" << std::endl;
+                )
+                PRINT(
+                        std::cerr << "there are " << candidates.size() << " alternatives after elimination"
+                                << std::endl;
+                )
+        }
+
+        // adjust types after pruning so that types substituted by pruneAlternatives are correctly
+        // adjusted
+        if ( mode.adjust ) {
+                for ( CandidateRef & r : candidates ) {
+                        r->expr = ast::mutate_field(
+                                r->expr.get(), &ast::Expr::result,
+                                adjustExprType( r->expr->result, r->env, context.symtab ) );
+                }
+        }
+
+        // Central location to handle gcc extension keyword, etc. for all expressions
+        for ( CandidateRef & r : candidates ) {
+                if ( r->expr->extension != expr->extension ) {
+                        r->expr.get_and_mutate()->extension = expr->extension;
+                }
+        }
+}
+
+std::vector< CandidateFinder > CandidateFinder::findSubExprs(
+        const std::vector< ast::ptr< ast::Expr > > & xs
+) {
+        std::vector< CandidateFinder > out;
+
+        for ( const auto & x : xs ) {
+                out.emplace_back( context, env );
+                out.back().find( x, ResolvMode::withAdjustment() );
+
+                PRINT(
+                        std::cerr << "findSubExprs" << std::endl;
+                        print( std::cerr, out.back().candidates );
+                )
+        }
+
+        return out;
+}
+
 const ast::Expr * referenceToRvalueConversion( const ast::Expr * expr, Cost & cost ) {
         if ( expr->result.as< ast::ReferenceType >() ) {
@@ -64 +1942 @@
         return expr;
 }
-
-/// Unique identifier for matching expression resolutions to their requesting expression
-UniqueId globalResnSlot = 0;
 
 Cost computeConversionCost(
@@ -93 +1968 @@
 }
 
-namespace {
-        /// First index is which argument, second is which alternative, third is which exploded element
-        using ExplodedArgs_new = std::deque< std::vector< ExplodedArg > >;
-
-        /// Returns a list of alternatives with the minimum cost in the given list
-        CandidateList findMinCost( const CandidateList & candidates ) {
-                CandidateList out;
-                Cost minCost = Cost::infinity;
-                for ( const CandidateRef & r : candidates ) {
-                        if ( r->cost < minCost ) {
-                                minCost = r->cost;
-                                out.clear();
-                                out.emplace_back( r );
-                        } else if ( r->cost == minCost ) {
-                                out.emplace_back( r );
-                        }
-                }
-                return out;
-        }
-
-        /// Computes conversion cost for a given expression to a given type
-        const ast::Expr * computeExpressionConversionCost(
-                const ast::Expr * arg, const ast::Type * paramType, const ast::SymbolTable & symtab, const ast::TypeEnvironment & env, Cost & outCost
-        ) {
-                Cost convCost = computeConversionCost(
-                                arg->result, paramType, arg->get_lvalue(), symtab, env );
-                outCost += convCost;
-
-                // If there is a non-zero conversion cost, ignoring poly cost, then the expression requires
-                // conversion. Ignore poly cost for now, since this requires resolution of the cast to
-                // infer parameters and this does not currently work for the reason stated below
-                Cost tmpCost = convCost;
-                tmpCost.incPoly( -tmpCost.get_polyCost() );
-                if ( tmpCost != Cost::zero ) {
-                        ast::ptr< ast::Type > newType = paramType;
-                        env.apply( newType );
-                        return new ast::CastExpr{ arg, newType };
-
-                        // xxx - *should* be able to resolve this cast, but at the moment pointers are not
-                        // castable to zero_t, but are implicitly convertible. This is clearly inconsistent,
-                        // once this is fixed it should be possible to resolve the cast.
-                        // xxx - this isn't working, it appears because type1 (parameter) is seen as widenable,
-                        // but it shouldn't be because this makes the conversion from DT* to DT* since
-                        // commontype(zero_t, DT*) is DT*, rather than nothing
-
-                        // CandidateFinder finder{ symtab, env };
-                        // finder.find( arg, ResolvMode::withAdjustment() );
-                        // assertf( finder.candidates.size() > 0,
-                        //      "Somehow castable expression failed to find alternatives." );
-                        // assertf( finder.candidates.size() == 1,
-                        //      "Somehow got multiple alternatives for known cast expression." );
-                        // return finder.candidates.front()->expr;
-                }
-
-                return arg;
-        }
-
-        /// Computes conversion cost for a given candidate
-        Cost computeApplicationConversionCost(
-                CandidateRef cand, const ast::SymbolTable & symtab
-        ) {
-                auto appExpr = cand->expr.strict_as< ast::ApplicationExpr >();
-                auto pointer = appExpr->func->result.strict_as< ast::PointerType >();
-                auto function = pointer->base.strict_as< ast::FunctionType >();
-
-                Cost convCost = Cost::zero;
-                const auto & params = function->params;
-                auto param = params.begin();
-                auto & args = appExpr->args;
-
-                for ( unsigned i = 0; i < args.size(); ++i ) {
-                        const ast::Type * argType = args[i]->result;
-                        PRINT(
-                                std::cerr << "arg expression:" << std::endl;
-                                ast::print( std::cerr, args[i], 2 );
-                                std::cerr << "--- results are" << std::endl;
-                                ast::print( std::cerr, argType, 2 );
-                        )
-
-                        if ( param == params.end() ) {
-                                if ( function->isVarArgs ) {
-                                        convCost.incUnsafe();
-                                        PRINT( std::cerr << "end of params with varargs function: inc unsafe: "
-                                                << convCost << std::endl; ; )
-                                        // convert reference-typed expressions into value-typed expressions
-                                        cand->expr = ast::mutate_field_index(
-                                                appExpr, &ast::ApplicationExpr::args, i,
-                                                referenceToRvalueConversion( args[i], convCost ) );
-                                        continue;
-                                } else return Cost::infinity;
-                        }
-
-                        if ( auto def = args[i].as< ast::DefaultArgExpr >() ) {
-                                // Default arguments should be free - don't include conversion cost.
-                                // Unwrap them here because they are not relevant to the rest of the system
-                                cand->expr = ast::mutate_field_index(
-                                        appExpr, &ast::ApplicationExpr::args, i, def->expr );
-                                ++param;
-                                continue;
-                        }
-
-                        // mark conversion cost and also specialization cost of param type
-                        // const ast::Type * paramType = (*param)->get_type();
-                        cand->expr = ast::mutate_field_index(
-                                appExpr, &ast::ApplicationExpr::args, i,
-                                computeExpressionConversionCost(
-                                        args[i], *param, symtab, cand->env, convCost ) );
-                        convCost.decSpec( specCost( *param ) );
-                        ++param;  // can't be in for-loop update because of the continue
-                }
-
-                if ( param != params.end() ) return Cost::infinity;
-
-                // specialization cost of return types can't be accounted for directly, it disables
-                // otherwise-identical calls, like this example based on auto-newline in the I/O lib:
-                //
-                //   forall(otype OS) {
-                //     void ?|?(OS&, int);  // with newline
-                //     OS&  ?|?(OS&, int);  // no newline, always chosen due to more specialization
-                //   }
-
-                // mark type variable and specialization cost of forall clause
-                convCost.incVar( function->forall.size() );
-                convCost.decSpec( function->assertions.size() );
-
-                return convCost;
-        }
-
-        void makeUnifiableVars(
-                const ast::FunctionType * type, ast::OpenVarSet & unifiableVars,
-                ast::AssertionSet & need
-        ) {
-                for ( auto & tyvar : type->forall ) {
-                        unifiableVars[ *tyvar ] = ast::TypeData{ tyvar->base };
-                }
-                for ( auto & assn : type->assertions ) {
-                        need[ assn ].isUsed = true;
-                }
-        }
-
-        /// Gets a default value from an initializer, nullptr if not present
-        const ast::ConstantExpr * getDefaultValue( const ast::Init * init ) {
-                if ( auto si = dynamic_cast< const ast::SingleInit * >( init ) ) {
-                        if ( auto ce = si->value.as< ast::CastExpr >() ) {
-                                return ce->arg.as< ast::ConstantExpr >();
-                        } else {
-                                return si->value.as< ast::ConstantExpr >();
-                        }
-                }
-                return nullptr;
-        }
-
-        /// State to iteratively build a match of parameter expressions to arguments
-        struct ArgPack {
-                std::size_t parent;          ///< Index of parent pack
-                ast::ptr< ast::Expr > expr;  ///< The argument stored here
-                Cost cost;                   ///< The cost of this argument
-                ast::TypeEnvironment env;    ///< Environment for this pack
-                ast::AssertionSet need;      ///< Assertions outstanding for this pack
-                ast::AssertionSet have;      ///< Assertions found for this pack
-                ast::OpenVarSet open;        ///< Open variables for this pack
-                unsigned nextArg;            ///< Index of next argument in arguments list
-                unsigned tupleStart;         ///< Number of tuples that start at this index
-                unsigned nextExpl;           ///< Index of next exploded element
-                unsigned explAlt;            ///< Index of alternative for nextExpl > 0
-
-                ArgPack()
-                : parent( 0 ), expr(), cost( Cost::zero ), env(), need(), have(), open(), nextArg( 0 ),
-                  tupleStart( 0 ), nextExpl( 0 ), explAlt( 0 ) {}
-
-                ArgPack(
-                        const ast::TypeEnvironment & env, const ast::AssertionSet & need,
-                        const ast::AssertionSet & have, const ast::OpenVarSet & open )
-                : parent( 0 ), expr(), cost( Cost::zero ), env( env ), need( need ), have( have ),
-                  open( open ), nextArg( 0 ), tupleStart( 0 ), nextExpl( 0 ), explAlt( 0 ) {}
-
-                ArgPack(
-                        std::size_t parent, const ast::Expr * expr, ast::TypeEnvironment && env,
-                        ast::AssertionSet && need, ast::AssertionSet && have, ast::OpenVarSet && open,
-                        unsigned nextArg, unsigned tupleStart = 0, Cost cost = Cost::zero,
-                        unsigned nextExpl = 0, unsigned explAlt = 0 )
-                : parent(parent), expr( expr ), cost( cost ), env( std::move( env ) ), need( std::move( need ) ),
-                  have( std::move( have ) ), open( std::move( open ) ), nextArg( nextArg ), tupleStart( tupleStart ),
-                  nextExpl( nextExpl ), explAlt( explAlt ) {}
-
-                ArgPack(
-                        const ArgPack & o, ast::TypeEnvironment && env, ast::AssertionSet && need,
-                        ast::AssertionSet && have, ast::OpenVarSet && open, unsigned nextArg, Cost added )
-                : parent( o.parent ), expr( o.expr ), cost( o.cost + added ), env( std::move( env ) ),
-                  need( std::move( need ) ), have( std::move( have ) ), open( std::move( open ) ), nextArg( nextArg ),
-                  tupleStart( o.tupleStart ), nextExpl( 0 ), explAlt( 0 ) {}
-
-                /// true if this pack is in the middle of an exploded argument
-                bool hasExpl() const { return nextExpl > 0; }
-
-                /// Gets the list of exploded candidates for this pack
-                const ExplodedArg & getExpl( const ExplodedArgs_new & args ) const {
-                        return args[ nextArg-1 ][ explAlt ];
-                }
-
-                /// Ends a tuple expression, consolidating the appropriate args
-                void endTuple( const std::vector< ArgPack > & packs ) {
-                        // add all expressions in tuple to list, summing cost
-                        std::deque< const ast::Expr * > exprs;
-                        const ArgPack * pack = this;
-                        if ( expr ) { exprs.emplace_front( expr ); }
-                        while ( pack->tupleStart == 0 ) {
-                                pack = &packs[pack->parent];
-                                exprs.emplace_front( pack->expr );
-                                cost += pack->cost;
-                        }
-                        // reset pack to appropriate tuple
-                        std::vector< ast::ptr< ast::Expr > > exprv( exprs.begin(), exprs.end() );
-                        expr = new ast::TupleExpr{ expr->location, std::move( exprv ) };
-                        tupleStart = pack->tupleStart - 1;
-                        parent = pack->parent;
-                }
-        };
-
-        /// Instantiates an argument to match a parameter, returns false if no matching results left
-        bool instantiateArgument(
-                const ast::Type * paramType, const ast::Init * init, const ExplodedArgs_new & args,
-                std::vector< ArgPack > & results, std::size_t & genStart, const ast::SymbolTable & symtab,
-                unsigned nTuples = 0
-        ) {
-                if ( auto tupleType = dynamic_cast< const ast::TupleType * >( paramType ) ) {
-                        // paramType is a TupleType -- group args into a TupleExpr
-                        ++nTuples;
-                        for ( const ast::Type * type : *tupleType ) {
-                                // xxx - dropping initializer changes behaviour from previous, but seems correct
-                                // ^^^ need to handle the case where a tuple has a default argument
-                                if ( ! instantiateArgument(
-                                        type, nullptr, args, results, genStart, symtab, nTuples ) ) return false;
-                                nTuples = 0;
-                        }
-                        // re-constitute tuples for final generation
-                        for ( auto i = genStart; i < results.size(); ++i ) {
-                                results[i].endTuple( results );
-                        }
-                        return true;
-                } else if ( const ast::TypeInstType * ttype = Tuples::isTtype( paramType ) ) {
-                        // paramType is a ttype, consumes all remaining arguments
-
-                        // completed tuples; will be spliced to end of results to finish
-                        std::vector< ArgPack > finalResults{};
-
-                        // iterate until all results completed
-                        std::size_t genEnd;
-                        ++nTuples;
-                        do {
-                                genEnd = results.size();
-
-                                // add another argument to results
-                                for ( std::size_t i = genStart; i < genEnd; ++i ) {
-                                        unsigned nextArg = results[i].nextArg;
-
-                                        // use next element of exploded tuple if present
-                                        if ( results[i].hasExpl() ) {
-                                                const ExplodedArg & expl = results[i].getExpl( args );
-
-                                                unsigned nextExpl = results[i].nextExpl + 1;
-                                                if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
-
-                                                results.emplace_back(
-                                                        i, expl.exprs[ results[i].nextExpl ], copy( results[i].env ),
-                                                        copy( results[i].need ), copy( results[i].have ),
-                                                        copy( results[i].open ), nextArg, nTuples, Cost::zero, nextExpl,
-                                                        results[i].explAlt );
-
-                                                continue;
-                                        }
-
-                                        // finish result when out of arguments
-                                        if ( nextArg >= args.size() ) {
-                                                ArgPack newResult{
-                                                        results[i].env, results[i].need, results[i].have, results[i].open };
-                                                newResult.nextArg = nextArg;
-                                                const ast::Type * argType = nullptr;
-
-                                                if ( nTuples > 0 || ! results[i].expr ) {
-                                                        // first iteration or no expression to clone,
-                                                        // push empty tuple expression
-                                                        newResult.parent = i;
-                                                        newResult.expr = new ast::TupleExpr{ CodeLocation{}, {} };
-                                                        argType = newResult.expr->result;
-                                                } else {
-                                                        // clone result to collect tuple
-                                                        newResult.parent = results[i].parent;
-                                                        newResult.cost = results[i].cost;
-                                                        newResult.tupleStart = results[i].tupleStart;
-                                                        newResult.expr = results[i].expr;
-                                                        argType = newResult.expr->result;
-
-                                                        if ( results[i].tupleStart > 0 && Tuples::isTtype( argType ) ) {
-                                                                // the case where a ttype value is passed directly is special,
-                                                                // e.g. for argument forwarding purposes
-                                                                // xxx - what if passing multiple arguments, last of which is
-                                                                //       ttype?
-                                                                // xxx - what would happen if unify was changed so that unifying
-                                                                //       tuple
-                                                                // types flattened both before unifying lists? then pass in
-                                                                // TupleType (ttype) below.
-                                                                --newResult.tupleStart;
-                                                        } else {
-                                                                // collapse leftover arguments into tuple
-                                                                newResult.endTuple( results );
-                                                                argType = newResult.expr->result;
-                                                        }
-                                                }
-
-                                                // check unification for ttype before adding to final
-                                                if (
-                                                        unify(
-                                                                ttype, argType, newResult.env, newResult.need, newResult.have,
-                                                                newResult.open, symtab )
-                                                ) {
-                                                        finalResults.emplace_back( std::move( newResult ) );
-                                                }
-
-                                                continue;
-                                        }
-
-                                        // add each possible next argument
-                                        for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
-                                                const ExplodedArg & expl = args[nextArg][j];
-
-                                                // fresh copies of parent parameters for this iteration
-                                                ast::TypeEnvironment env = results[i].env;
-                                                ast::OpenVarSet open = results[i].open;
-
-                                                env.addActual( expl.env, open );
-
-                                                // skip empty tuple arguments by (nearly) cloning parent into next gen
-                                                if ( expl.exprs.empty() ) {
-                                                        results.emplace_back(
-                                                                results[i], std::move( env ), copy( results[i].need ),
-                                                                copy( results[i].have ), std::move( open ), nextArg + 1, expl.cost );
-
-                                                        continue;
-                                                }
-
-                                                // add new result
-                                                results.emplace_back(
-                                                        i, expl.exprs.front(), std::move( env ), copy( results[i].need ),
-                                                        copy( results[i].have ), std::move( open ), nextArg + 1, nTuples,
-                                                        expl.cost, expl.exprs.size() == 1 ? 0 : 1, j );
-                                        }
-                                }
-
-                                // reset for next round
-                                genStart = genEnd;
-                                nTuples = 0;
-                        } while ( genEnd != results.size() );
-
-                        // splice final results onto results
-                        for ( std::size_t i = 0; i < finalResults.size(); ++i ) {
-                                results.emplace_back( std::move( finalResults[i] ) );
-                        }
-                        return ! finalResults.empty();
-                }
-
-                // iterate each current subresult
-                std::size_t genEnd = results.size();
-                for ( std::size_t i = genStart; i < genEnd; ++i ) {
-                        unsigned nextArg = results[i].nextArg;
-
-                        // use remainder of exploded tuple if present
-                        if ( results[i].hasExpl() ) {
-                                const ExplodedArg & expl = results[i].getExpl( args );
-                                const ast::Expr * expr = expl.exprs[ results[i].nextExpl ];
-
-                                ast::TypeEnvironment env = results[i].env;
-                                ast::AssertionSet need = results[i].need, have = results[i].have;
-                                ast::OpenVarSet open = results[i].open;
-
-                                const ast::Type * argType = expr->result;
-
-                                PRINT(
-                                        std::cerr << "param type is ";
-                                        ast::print( std::cerr, paramType );
-                                        std::cerr << std::endl << "arg type is ";
-                                        ast::print( std::cerr, argType );
-                                        std::cerr << std::endl;
-                                )
-
-                                if ( unify( paramType, argType, env, need, have, open, symtab ) ) {
-                                        unsigned nextExpl = results[i].nextExpl + 1;
-                                        if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
-
-                                        results.emplace_back(
-                                                i, expr, std::move( env ), std::move( need ), std::move( have ), std::move( open ), nextArg,
-                                                nTuples, Cost::zero, nextExpl, results[i].explAlt );
-                                }
-
-                                continue;
-                        }
-
-                        // use default initializers if out of arguments
-                        if ( nextArg >= args.size() ) {
-                                if ( const ast::ConstantExpr * cnst = getDefaultValue( init ) ) {
-                                        ast::TypeEnvironment env = results[i].env;
-                                        ast::AssertionSet need = results[i].need, have = results[i].have;
-                                        ast::OpenVarSet open = results[i].open;
-
-                                        if ( unify( paramType, cnst->result, env, need, have, open, symtab ) ) {
-                                                results.emplace_back(
-                                                        i, new ast::DefaultArgExpr{ cnst->location, cnst }, std::move( env ),
-                                                        std::move( need ), std::move( have ), std::move( open ), nextArg, nTuples );
-                                        }
-                                }
-
-                                continue;
-                        }
-
-                        // Check each possible next argument
-                        for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
-                                const ExplodedArg & expl = args[nextArg][j];
-
-                                // fresh copies of parent parameters for this iteration
-                                ast::TypeEnvironment env = results[i].env;
-                                ast::AssertionSet need = results[i].need, have = results[i].have;
-                                ast::OpenVarSet open = results[i].open;
-
-                                env.addActual( expl.env, open );
-
-                                // skip empty tuple arguments by (nearly) cloning parent into next gen
-                                if ( expl.exprs.empty() ) {
-                                        results.emplace_back(
-                                                results[i], std::move( env ), std::move( need ), std::move( have ), std::move( open ),
-                                                nextArg + 1, expl.cost );
-
-                                        continue;
-                                }
-
-                                // consider only first exploded arg
-                                const ast::Expr * expr = expl.exprs.front();
-                                const ast::Type * argType = expr->result;
-
-                                PRINT(
-                                        std::cerr << "param type is ";
-                                        ast::print( std::cerr, paramType );
-                                        std::cerr << std::endl << "arg type is ";
-                                        ast::print( std::cerr, argType );
-                                        std::cerr << std::endl;
-                                )
-
-                                // attempt to unify types
-                                if ( unify( paramType, argType, env, need, have, open, symtab ) ) {
-                                        // add new result
-                                        results.emplace_back(
-                                                i, expr, std::move( env ), std::move( need ), std::move( have ), std::move( open ),
-                                                nextArg + 1, nTuples, expl.cost, expl.exprs.size() == 1 ? 0 : 1, j );
-                                }
-                        }
-                }
-
-                // reset for next parameter
-                genStart = genEnd;
-
-                return genEnd != results.size();  // were any new results added?
-        }
-
-        /// Generate a cast expression from `arg` to `toType`
-        const ast::Expr * restructureCast(
-                ast::ptr< ast::Expr > & arg, const ast::Type * toType, ast::GeneratedFlag isGenerated = ast::GeneratedCast
-        ) {
-                if (
-                        arg->result->size() > 1
-                        && ! toType->isVoid()
-                        && ! dynamic_cast< const ast::ReferenceType * >( toType )
-                ) {
-                        // Argument is a tuple and the target type is neither void nor a reference. Cast each
-                        // member of the tuple to its corresponding target type, producing the tuple of those
-                        // cast expressions. If there are more components of the tuple than components in the
-                        // target type, then excess components do not come out in the result expression (but
-                        // UniqueExpr ensures that the side effects will still be produced)
-                        if ( Tuples::maybeImpureIgnoreUnique( arg ) ) {
-                                // expressions which may contain side effects require a single unique instance of
-                                // the expression
-                                arg = new ast::UniqueExpr{ arg->location, arg };
-                        }
-                        std::vector< ast::ptr< ast::Expr > > components;
-                        for ( unsigned i = 0; i < toType->size(); ++i ) {
-                                // cast each component
-                                ast::ptr< ast::Expr > idx = new ast::TupleIndexExpr{ arg->location, arg, i };
-                                components.emplace_back(
-                                        restructureCast( idx, toType->getComponent( i ), isGenerated ) );
-                        }
-                        return new ast::TupleExpr{ arg->location, std::move( components ) };
-                } else {
-                        // handle normally
-                        return new ast::CastExpr{ arg->location, arg, toType, isGenerated };
-                }
-        }
-
-        /// Gets the name from an untyped member expression (must be NameExpr)
-        const std::string & getMemberName( const ast::UntypedMemberExpr * memberExpr ) {
-                if ( memberExpr->member.as< ast::ConstantExpr >() ) {
-                        SemanticError( memberExpr, "Indexed access to struct fields unsupported: " );
-                }
-
-                return memberExpr->member.strict_as< ast::NameExpr >()->name;
-        }
-
-        /// Actually visits expressions to find their candidate interpretations
-        class Finder final : public ast::WithShortCircuiting {
-                const ResolveContext & context;
-                const ast::SymbolTable & symtab;
-        public:
-                // static size_t traceId;
-                CandidateFinder & selfFinder;
-                CandidateList & candidates;
-                const ast::TypeEnvironment & tenv;
-                ast::ptr< ast::Type > & targetType;
-
-                enum Errors {
-                        NotFound,
-                        NoMatch,
-                        ArgsToFew,
-                        ArgsToMany,
-                        RetsToFew,
-                        RetsToMany,
-                        NoReason
-                };
-
-                struct {
-                        Errors code = NotFound;
-                } reason;
-
-                Finder( CandidateFinder & f )
-                : context( f.context ), symtab( context.symtab ), selfFinder( f ),
-                  candidates( f.candidates ), tenv( f.env ), targetType( f.targetType ) {}
-
-                void previsit( const ast::Node * ) { visit_children = false; }
-
-                /// Convenience to add candidate to list
-                template<typename... Args>
-                void addCandidate( Args &&... args ) {
-                        candidates.emplace_back( new Candidate{ std::forward<Args>( args )... } );
-                        reason.code = NoReason;
-                }
-
-                void postvisit( const ast::ApplicationExpr * applicationExpr ) {
-                        addCandidate( applicationExpr, tenv );
-                }
-
-                /// Set up candidate assertions for inference
-                void inferParameters( CandidateRef & newCand, CandidateList & out ) {
-                        // Set need bindings for any unbound assertions
-                        UniqueId crntResnSlot = 0; // matching ID for this expression's assertions
-                        for ( auto & assn : newCand->need ) {
-                                // skip already-matched assertions
-                                if ( assn.second.resnSlot != 0 ) continue;
-                                // assign slot for expression if needed
-                                if ( crntResnSlot == 0 ) { crntResnSlot = ++globalResnSlot; }
-                                // fix slot to assertion
-                                assn.second.resnSlot = crntResnSlot;
-                        }
-                        // pair slot to expression
-                        if ( crntResnSlot != 0 ) {
-                                newCand->expr.get_and_mutate()->inferred.resnSlots().emplace_back( crntResnSlot );
-                        }
-
-                        // add to output list; assertion satisfaction will occur later
-                        out.emplace_back( newCand );
-                }
-
-                /// Completes a function candidate with arguments located
-                void validateFunctionCandidate(
-                        const CandidateRef & func, ArgPack & result, const std::vector< ArgPack > & results,
-                        CandidateList & out
-                ) {
-                        ast::ApplicationExpr * appExpr =
-                                new ast::ApplicationExpr{ func->expr->location, func->expr };
-                        // sum cost and accumulate arguments
-                        std::deque< const ast::Expr * > args;
-                        Cost cost = func->cost;
-                        const ArgPack * pack = &result;
-                        while ( pack->expr ) {
-                                args.emplace_front( pack->expr );
-                                cost += pack->cost;
-                                pack = &results[pack->parent];
-                        }
-                        std::vector< ast::ptr< ast::Expr > > vargs( args.begin(), args.end() );
-                        appExpr->args = std::move( vargs );
-                        // build and validate new candidate
-                        auto newCand =
-                                std::make_shared<Candidate>( appExpr, result.env, result.open, result.need, cost );
-                        PRINT(
-                                std::cerr << "instantiate function success: " << appExpr << std::endl;
-                                std::cerr << "need assertions:" << std::endl;
-                                ast::print( std::cerr, result.need, 2 );
-                        )
-                        inferParameters( newCand, out );
-                }
-
-                /// Builds a list of candidates for a function, storing them in out
-                void makeFunctionCandidates(
-                        const CandidateRef & func, const ast::FunctionType * funcType,
-                        const ExplodedArgs_new & args, CandidateList & out
-                ) {
-                        ast::OpenVarSet funcOpen;
-                        ast::AssertionSet funcNeed, funcHave;
-                        ast::TypeEnvironment funcEnv{ func->env };
-                        makeUnifiableVars( funcType, funcOpen, funcNeed );
-                        // add all type variables as open variables now so that those not used in the
-                        // parameter list are still considered open
-                        funcEnv.add( funcType->forall );
-
-                        if ( targetType && ! targetType->isVoid() && ! funcType->returns.empty() ) {
-                                // attempt to narrow based on expected target type
-                                const ast::Type * returnType = funcType->returns.front();
-                                if ( ! unify(
-                                        returnType, targetType, funcEnv, funcNeed, funcHave, funcOpen, symtab )
-                                ) {
-                                        // unification failed, do not pursue this candidate
-                                        return;
-                                }
-                        }
-
-                        // iteratively build matches, one parameter at a time
-                        std::vector< ArgPack > results;
-                        results.emplace_back( funcEnv, funcNeed, funcHave, funcOpen );
-                        std::size_t genStart = 0;
-
-                        // xxx - how to handle default arg after change to ftype representation?
-                        if (const ast::VariableExpr * varExpr = func->expr.as<ast::VariableExpr>()) {
-                                if (const ast::FunctionDecl * funcDecl = varExpr->var.as<ast::FunctionDecl>()) {
-                                        // function may have default args only if directly calling by name
-                                        // must use types on candidate however, due to RenameVars substitution
-                                        auto nParams = funcType->params.size();
-
-                                        for (size_t i=0; i<nParams; ++i) {
-                                                auto obj = funcDecl->params[i].strict_as<ast::ObjectDecl>();
-                                                if (!instantiateArgument(
-                                                        funcType->params[i], obj->init, args, results, genStart, symtab)) return;
-                                        }
-                                        goto endMatch;
-                                }
-                        }
-                        for ( const auto & param : funcType->params ) {
-                                // Try adding the arguments corresponding to the current parameter to the existing
-                                // matches
-                                // no default args for indirect calls
-                                if ( ! instantiateArgument(
-                                        param, nullptr, args, results, genStart, symtab ) ) return;
-                        }
-
-                        endMatch:
-                        if ( funcType->isVarArgs ) {
-                                // append any unused arguments to vararg pack
-                                std::size_t genEnd;
-                                do {
-                                        genEnd = results.size();
-
-                                        // iterate results
-                                        for ( std::size_t i = genStart; i < genEnd; ++i ) {
-                                                unsigned nextArg = results[i].nextArg;
-
-                                                // use remainder of exploded tuple if present
-                                                if ( results[i].hasExpl() ) {
-                                                        const ExplodedArg & expl = results[i].getExpl( args );
-
-                                                        unsigned nextExpl = results[i].nextExpl + 1;
-                                                        if ( nextExpl == expl.exprs.size() ) { nextExpl = 0; }
-
-                                                        results.emplace_back(
-                                                                i, expl.exprs[ results[i].nextExpl ], copy( results[i].env ),
-                                                                copy( results[i].need ), copy( results[i].have ),
-                                                                copy( results[i].open ), nextArg, 0, Cost::zero, nextExpl,
-                                                                results[i].explAlt );
-
-                                                        continue;
-                                                }
-
-                                                // finish result when out of arguments
-                                                if ( nextArg >= args.size() ) {
-                                                        validateFunctionCandidate( func, results[i], results, out );
-
-                                                        continue;
-                                                }
-
-                                                // add each possible next argument
-                                                for ( std::size_t j = 0; j < args[nextArg].size(); ++j ) {
-                                                        const ExplodedArg & expl = args[nextArg][j];
-
-                                                        // fresh copies of parent parameters for this iteration
-                                                        ast::TypeEnvironment env = results[i].env;
-                                                        ast::OpenVarSet open = results[i].open;
-
-                                                        env.addActual( expl.env, open );
-
-                                                        // skip empty tuple arguments by (nearly) cloning parent into next gen
-                                                        if ( expl.exprs.empty() ) {
-                                                                results.emplace_back(
-                                                                        results[i], std::move( env ), copy( results[i].need ),
-                                                                        copy( results[i].have ), std::move( open ), nextArg + 1,
-                                                                        expl.cost );
-
-                                                                continue;
-                                                        }
-
-                                                        // add new result
-                                                        results.emplace_back(
-                                                                i, expl.exprs.front(), std::move( env ), copy( results[i].need ),
-                                                                copy( results[i].have ), std::move( open ), nextArg + 1, 0, expl.cost,
-                                                                expl.exprs.size() == 1 ? 0 : 1, j );
-                                                }
-                                        }
-
-                                        genStart = genEnd;
-                                } while( genEnd != results.size() );
-                        } else {
-                                // filter out the results that don't use all the arguments
-                                for ( std::size_t i = genStart; i < results.size(); ++i ) {
-                                        ArgPack & result = results[i];
-                                        if ( ! result.hasExpl() && result.nextArg >= args.size() ) {
-                                                validateFunctionCandidate( func, result, results, out );
-                                        }
-                                }
-                        }
-                }
-
-                /// Adds implicit struct-conversions to the alternative list
-                void addAnonConversions( const CandidateRef & cand ) {
-                        // adds anonymous member interpretations whenever an aggregate value type is seen.
-                        // it's okay for the aggregate expression to have reference type -- cast it to the
-                        // base type to treat the aggregate as the referenced value
-                        ast::ptr< ast::Expr > aggrExpr( cand->expr );
-                        ast::ptr< ast::Type > & aggrType = aggrExpr.get_and_mutate()->result;
-                        cand->env.apply( aggrType );
-
-                        if ( aggrType.as< ast::ReferenceType >() ) {
-                                aggrExpr = new ast::CastExpr{ aggrExpr, aggrType->stripReferences() };
-                        }
-
-                        if ( auto structInst = aggrExpr->result.as< ast::StructInstType >() ) {
-                                addAggMembers( structInst, aggrExpr, *cand, Cost::safe, "" );
-                        } else if ( auto unionInst = aggrExpr->result.as< ast::UnionInstType >() ) {
-                                addAggMembers( unionInst, aggrExpr, *cand, Cost::safe, "" );
-                        }
-                }
-
-                /// Adds aggregate member interpretations
-                void addAggMembers(
-                        const ast::BaseInstType * aggrInst, const ast::Expr * expr,
-                        const Candidate & cand, const Cost & addedCost, const std::string & name
-                ) {
-                        for ( const ast::Decl * decl : aggrInst->lookup( name ) ) {
-                                auto dwt = strict_dynamic_cast< const ast::DeclWithType * >( decl );
-                                CandidateRef newCand = std::make_shared<Candidate>(
-                                        cand, new ast::MemberExpr{ expr->location, dwt, expr }, addedCost );
-                                // add anonymous member interpretations whenever an aggregate value type is seen
-                                // as a member expression
-                                addAnonConversions( newCand );
-                                candidates.emplace_back( std::move( newCand ) );
-                        }
-                }
-
-                /// Adds tuple member interpretations
-                void addTupleMembers(
-                        const ast::TupleType * tupleType, const ast::Expr * expr, const Candidate & cand,
-                        const Cost & addedCost, const ast::Expr * member
-                ) {
-                        if ( auto constantExpr = dynamic_cast< const ast::ConstantExpr * >( member ) ) {
-                                // get the value of the constant expression as an int, must be between 0 and the
-                                // length of the tuple to have meaning
-                                long long val = constantExpr->intValue();
-                                if ( val >= 0 && (unsigned long long)val < tupleType->size() ) {
-                                        addCandidate(
-                                                cand, new ast::TupleIndexExpr{ expr->location, expr, (unsigned)val },
-                                                addedCost );
-                                }
-                        }
-                }
-
-                void postvisit( const ast::UntypedExpr * untypedExpr ) {
-                        std::vector< CandidateFinder > argCandidates =
-                                selfFinder.findSubExprs( untypedExpr->args );
-
-                        // take care of possible tuple assignments
-                        // if not tuple assignment, handled as normal function call
-                        Tuples::handleTupleAssignment( selfFinder, untypedExpr, argCandidates );
-
-                        CandidateFinder funcFinder( context, tenv );
-                        if (auto nameExpr = untypedExpr->func.as<ast::NameExpr>()) {
-                                auto kind = ast::SymbolTable::getSpecialFunctionKind(nameExpr->name);
-                                if (kind != ast::SymbolTable::SpecialFunctionKind::NUMBER_OF_KINDS) {
-                                        assertf(!argCandidates.empty(), "special function call without argument");
-                                        for (auto & firstArgCand: argCandidates[0]) {
-                                                ast::ptr<ast::Type> argType = firstArgCand->expr->result;
-                                                firstArgCand->env.apply(argType);
-                                                // strip references
-                                                // xxx - is this correct?
-                                                while (argType.as<ast::ReferenceType>()) argType = argType.as<ast::ReferenceType>()->base;
-
-                                                // convert 1-tuple to plain type
-                                                if (auto tuple = argType.as<ast::TupleType>()) {
-                                                        if (tuple->size() == 1) {
-                                                                argType = tuple->types[0];
-                                                        }
-                                                }
-
-                                                // if argType is an unbound type parameter, all special functions need to be searched.
-                                                if (isUnboundType(argType)) {
-                                                        funcFinder.otypeKeys.clear();
-                                                        break;
-                                                }
-
-                                                if (argType.as<ast::PointerType>()) funcFinder.otypeKeys.insert(Mangle::Encoding::pointer);                                             
-                                                // else if (const ast::EnumInstType * enumInst = argType.as<ast::EnumInstType>()) {
-                                                //      const ast::EnumDecl * enumDecl = enumInst->base; // Here
-                                                //      if ( const ast::Type* enumType = enumDecl->base ) {
-                                                //              // instance of enum (T) is a instance of type (T) 
-                                                //              funcFinder.otypeKeys.insert(Mangle::mangle(enumType, Mangle::NoGenericParams | Mangle::Type));
-                                                //      } else {
-                                                //              // instance of an untyped enum is techically int
-                                                //              funcFinder.otypeKeys.insert(Mangle::mangle(enumDecl, Mangle::NoGenericParams | Mangle::Type));
-                                                //      }
-                                                // }
-                                                else funcFinder.otypeKeys.insert(Mangle::mangle(argType, Mangle::NoGenericParams | Mangle::Type));
-                                        }
-                                }
-                        }
-                        // if candidates are already produced, do not fail
-                        // xxx - is it possible that handleTupleAssignment and main finder both produce candidates?
-                        // this means there exists ctor/assign functions with a tuple as first parameter.
-                        ResolvMode mode = {
-                                true, // adjust
-                                !untypedExpr->func.as<ast::NameExpr>(), // prune if not calling by name
-                                selfFinder.candidates.empty() // failfast if other options are not found
-                        };
-                        funcFinder.find( untypedExpr->func, mode );
-                        // short-circuit if no candidates
-                        // if ( funcFinder.candidates.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        // find function operators
-                        ast::ptr< ast::Expr > opExpr = new ast::NameExpr{ untypedExpr->location, "?()" }; // ??? why not ?{}
-                        CandidateFinder opFinder( context, tenv );
-                        // okay if there aren't any function operations
-                        opFinder.find( opExpr, ResolvMode::withoutFailFast() );
-                        PRINT(
-                                std::cerr << "known function ops:" << std::endl;
-                                print( std::cerr, opFinder.candidates, 1 );
-                        )
-
-                        // pre-explode arguments
-                        ExplodedArgs_new argExpansions;
-                        for ( const CandidateFinder & args : argCandidates ) {
-                                argExpansions.emplace_back();
-                                auto & argE = argExpansions.back();
-                                for ( const CandidateRef & arg : args ) { argE.emplace_back( *arg, symtab ); }
-                        }
-
-                        // Find function matches
-                        CandidateList found;
-                        SemanticErrorException errors;
-                        for ( CandidateRef & func : funcFinder ) {
-                                try {
-                                        PRINT(
-                                                std::cerr << "working on alternative:" << std::endl;
-                                                print( std::cerr, *func, 2 );
-                                        )
-
-                                        // check if the type is a pointer to function
-                                        const ast::Type * funcResult = func->expr->result->stripReferences();
-                                        if ( auto pointer = dynamic_cast< const ast::PointerType * >( funcResult ) ) {
-                                                if ( auto function = pointer->base.as< ast::FunctionType >() ) {
-                                                        CandidateRef newFunc{ new Candidate{ *func } };
-                                                        newFunc->expr =
-                                                                referenceToRvalueConversion( newFunc->expr, newFunc->cost );
-                                                        makeFunctionCandidates( newFunc, function, argExpansions, found );
-                                                }
-                                        } else if (
-                                                auto inst = dynamic_cast< const ast::TypeInstType * >( funcResult )
-                                        ) {
-                                                if ( const ast::EqvClass * clz = func->env.lookup( *inst ) ) {
-                                                        if ( auto function = clz->bound.as< ast::FunctionType >() ) {
-                                                                CandidateRef newFunc{ new Candidate{ *func } };
-                                                                newFunc->expr =
-                                                                        referenceToRvalueConversion( newFunc->expr, newFunc->cost );
-                                                                makeFunctionCandidates( newFunc, function, argExpansions, found );
-                                                        }
-                                                }
-                                        }
-                                } catch ( SemanticErrorException & e ) { errors.append( e ); }
-                        }
-
-                        // Find matches on function operators `?()`
-                        if ( ! opFinder.candidates.empty() ) {
-                                // add exploded function alternatives to front of argument list
-                                std::vector< ExplodedArg > funcE;
-                                funcE.reserve( funcFinder.candidates.size() );
-                                for ( const CandidateRef & func : funcFinder ) {
-                                        funcE.emplace_back( *func, symtab );
-                                }
-                                argExpansions.emplace_front( std::move( funcE ) );
-
-                                for ( const CandidateRef & op : opFinder ) {
-                                        try {
-                                                // check if type is pointer-to-function
-                                                const ast::Type * opResult = op->expr->result->stripReferences();
-                                                if ( auto pointer = dynamic_cast< const ast::PointerType * >( opResult ) ) {
-                                                        if ( auto function = pointer->base.as< ast::FunctionType >() ) {
-                                                                CandidateRef newOp{ new Candidate{ *op} };
-                                                                newOp->expr =
-                                                                        referenceToRvalueConversion( newOp->expr, newOp->cost );
-                                                                makeFunctionCandidates( newOp, function, argExpansions, found );
-                                                        }
-                                                }
-                                        } catch ( SemanticErrorException & e ) { errors.append( e ); }
-                                }
-                        }
-
-                        // Implement SFINAE; resolution errors are only errors if there aren't any non-error
-                        // candidates
-                        if ( found.empty() && ! errors.isEmpty() ) { throw errors; }
-
-                        // Compute conversion costs
-                        for ( CandidateRef & withFunc : found ) {
-                                Cost cvtCost = computeApplicationConversionCost( withFunc, symtab );
-
-                                PRINT(
-                                        auto appExpr = withFunc->expr.strict_as< ast::ApplicationExpr >();
-                                        auto pointer = appExpr->func->result.strict_as< ast::PointerType >();
-                                        auto function = pointer->base.strict_as< ast::FunctionType >();
-
-                                        std::cerr << "Case +++++++++++++ " << appExpr->func << std::endl;
-                                        std::cerr << "parameters are:" << std::endl;
-                                        ast::printAll( std::cerr, function->params, 2 );
-                                        std::cerr << "arguments are:" << std::endl;
-                                        ast::printAll( std::cerr, appExpr->args, 2 );
-                                        std::cerr << "bindings are:" << std::endl;
-                                        ast::print( std::cerr, withFunc->env, 2 );
-                                        std::cerr << "cost is: " << withFunc->cost << std::endl;
-                                        std::cerr << "cost of conversion is:" << cvtCost << std::endl;
-                                )
-
-                                if ( cvtCost != Cost::infinity ) {
-                                        withFunc->cvtCost = cvtCost;
-                                        candidates.emplace_back( std::move( withFunc ) );
-                                }
-                        }
-                        found = std::move( candidates );
-
-                        // use a new list so that candidates are not examined by addAnonConversions twice
-                        CandidateList winners = findMinCost( found );
-                        promoteCvtCost( winners );
-
-                        // function may return a struct/union value, in which case we need to add candidates
-                        // for implicit conversions to each of the anonymous members, which must happen after
-                        // `findMinCost`, since anon conversions are never the cheapest
-                        for ( const CandidateRef & c : winners ) {
-                                addAnonConversions( c );
-                        }
-                        spliceBegin( candidates, winners );
-
-                        if ( candidates.empty() && targetType && ! targetType->isVoid() ) {
-                                // If resolution is unsuccessful with a target type, try again without, since it
-                                // will sometimes succeed when it wouldn't with a target type binding.
-                                // For example:
-                                //   forall( otype T ) T & ?[]( T *, ptrdiff_t );
-                                //   const char * x = "hello world";
-                                //   unsigned char ch = x[0];
-                                // Fails with simple return type binding (xxx -- check this!) as follows:
-                                // * T is bound to unsigned char
-                                // * (x: const char *) is unified with unsigned char *, which fails
-                                // xxx -- fix this better
-                                targetType = nullptr;
-                                postvisit( untypedExpr );
-                        }
-                }
-
-                /// true if expression is an lvalue
-                static bool isLvalue( const ast::Expr * x ) {
-                        return x->result && ( x->get_lvalue() || x->result.as< ast::ReferenceType >() );
-                }
-
-                void postvisit( const ast::AddressExpr * addressExpr ) {
-                        CandidateFinder finder( context, tenv );
-                        finder.find( addressExpr->arg );
-
-                        if( finder.candidates.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        for ( CandidateRef & r : finder.candidates ) {
-                                if ( ! isLvalue( r->expr ) ) continue;
-                                addCandidate( *r, new ast::AddressExpr{ addressExpr->location, r->expr } );
-                        }
-                }
-
-                void postvisit( const ast::LabelAddressExpr * labelExpr ) {
-                        addCandidate( labelExpr, tenv );
-                }
-
-                void postvisit( const ast::CastExpr * castExpr ) {
-                        ast::ptr< ast::Type > toType = castExpr->result;
-                        assert( toType );
-                        toType = resolveTypeof( toType, context );
-                        toType = adjustExprType( toType, tenv, symtab );
-
-                        CandidateFinder finder( context, tenv, toType );
-                        finder.find( castExpr->arg, ResolvMode::withAdjustment() );
-
-                        if( !finder.candidates.empty() ) reason.code = NoMatch;
-
-                        CandidateList matches;
-                        for ( CandidateRef & cand : finder.candidates ) {
-                                ast::AssertionSet need( cand->need.begin(), cand->need.end() ), have;
-                                ast::OpenVarSet open( cand->open );
-
-                                cand->env.extractOpenVars( open );
-
-                                // It is possible that a cast can throw away some values in a multiply-valued
-                                // expression, e.g. cast-to-void, one value to zero. Figure out the prefix of the
-                                // subexpression results that are cast directly. The candidate is invalid if it
-                                // has fewer results than there are types to cast to.
-                                int discardedValues = cand->expr->result->size() - toType->size();
-                                if ( discardedValues < 0 ) continue;
-
-                                // unification run for side-effects
-                                unify( toType, cand->expr->result, cand->env, need, have, open, symtab );
-                                Cost thisCost =
-                                        (castExpr->isGenerated == ast::GeneratedFlag::GeneratedCast)
-                            ? conversionCost( cand->expr->result, toType, cand->expr->get_lvalue(), symtab, cand->env )
-                            : castCost( cand->expr->result, toType, cand->expr->get_lvalue(), symtab, cand->env );
-
-                                PRINT(
-                                        std::cerr << "working on cast with result: " << toType << std::endl;
-                                        std::cerr << "and expr type: " << cand->expr->result << std::endl;
-                                        std::cerr << "env: " << cand->env << std::endl;
-                                )
-                                if ( thisCost != Cost::infinity ) {
-                                        PRINT(
-                                                std::cerr << "has finite cost." << std::endl;
-                                        )
-                                        // count one safe conversion for each value that is thrown away
-                                        thisCost.incSafe( discardedValues );
-                                        CandidateRef newCand = std::make_shared<Candidate>(
-                                                restructureCast( cand->expr, toType, castExpr->isGenerated ),
-                                                copy( cand->env ), std::move( open ), std::move( need ), cand->cost,
-                                                cand->cost + thisCost );
-                                        inferParameters( newCand, matches );
-                                }
-                        }
-
-                        // select first on argument cost, then conversion cost
-                        CandidateList minArgCost = findMinCost( matches );
-                        promoteCvtCost( minArgCost );
-                        candidates = findMinCost( minArgCost );
-                }
-
-                void postvisit( const ast::VirtualCastExpr * castExpr ) {
-                        assertf( castExpr->result, "Implicit virtual cast targets not yet supported." );
-                        CandidateFinder finder( context, tenv );
-                        // don't prune here, all alternatives guaranteed to have same type
-                        finder.find( castExpr->arg, ResolvMode::withoutPrune() );
-                        for ( CandidateRef & r : finder.candidates ) {
-                                addCandidate(
-                                        *r,
-                                        new ast::VirtualCastExpr{ castExpr->location, r->expr, castExpr->result } );
-                        }
-                }
-
-                void postvisit( const ast::KeywordCastExpr * castExpr ) {
-                        const auto & loc = castExpr->location;
-                        assertf( castExpr->result, "Cast target should have been set in Validate." );
-                        auto ref = castExpr->result.strict_as<ast::ReferenceType>();
-                        auto inst = ref->base.strict_as<ast::StructInstType>();
-                        auto target = inst->base.get();
-
-                        CandidateFinder finder( context, tenv );
-
-                        auto pick_alternatives = [target, this](CandidateList & found, bool expect_ref) {
-                                for(auto & cand : found) {
-                                        const ast::Type * expr = cand->expr->result.get();
-                                        if(expect_ref) {
-                                                auto res = dynamic_cast<const ast::ReferenceType*>(expr);
-                                                if(!res) { continue; }
-                                                expr = res->base.get();
-                                        }
-
-                                        if(auto insttype = dynamic_cast<const ast::TypeInstType*>(expr)) {
-                                                auto td = cand->env.lookup(*insttype);
-                                                if(!td) { continue; }
-                                                expr = td->bound.get();
-                                        }
-
-                                        if(auto base = dynamic_cast<const ast::StructInstType*>(expr)) {
-                                                if(base->base == target) {
-                                                        candidates.push_back( std::move(cand) );
-                                                        reason.code = NoReason;
-                                                }
-                                        }
-                                }
-                        };
-
-                        try {
-                                // Attempt 1 : turn (thread&)X into (thread$&)X.__thrd
-                                // Clone is purely for memory management
-                                std::unique_ptr<const ast::Expr> tech1 { new ast::UntypedMemberExpr(loc, new ast::NameExpr(loc, castExpr->concrete_target.field), castExpr->arg) };
-
-                                // don't prune here, since it's guaranteed all alternatives will have the same type
-                                finder.find( tech1.get(), ResolvMode::withoutPrune() );
-                                pick_alternatives(finder.candidates, false);
-
-                                return;
-                        } catch(SemanticErrorException & ) {}
-
-                        // Fallback : turn (thread&)X into (thread$&)get_thread(X)
-                        std::unique_ptr<const ast::Expr> fallback { ast::UntypedExpr::createDeref(loc,  new ast::UntypedExpr(loc, new ast::NameExpr(loc, castExpr->concrete_target.getter), { castExpr->arg })) };
-                        // don't prune here, since it's guaranteed all alternatives will have the same type
-                        finder.find( fallback.get(), ResolvMode::withoutPrune() );
-
-                        pick_alternatives(finder.candidates, true);
-
-                        // Whatever happens here, we have no more fallbacks
-                }
-
-                void postvisit( const ast::UntypedMemberExpr * memberExpr ) {
-                        CandidateFinder aggFinder( context, tenv );
-                        aggFinder.find( memberExpr->aggregate, ResolvMode::withAdjustment() );
-                        for ( CandidateRef & agg : aggFinder.candidates ) {
-                                // it's okay for the aggregate expression to have reference type -- cast it to the
-                                // base type to treat the aggregate as the referenced value
-                                Cost addedCost = Cost::zero;
-                                agg->expr = referenceToRvalueConversion( agg->expr, addedCost );
-
-                                // find member of the given type
-                                if ( auto structInst = agg->expr->result.as< ast::StructInstType >() ) {
-                                        addAggMembers(
-                                                structInst, agg->expr, *agg, addedCost, getMemberName( memberExpr ) );
-                                } else if ( auto unionInst = agg->expr->result.as< ast::UnionInstType >() ) {
-                                        addAggMembers(
-                                                unionInst, agg->expr, *agg, addedCost, getMemberName( memberExpr ) );
-                                } else if ( auto tupleType = agg->expr->result.as< ast::TupleType >() ) {
-                                        addTupleMembers( tupleType, agg->expr, *agg, addedCost, memberExpr->member );
-                                }
-                        }
-                }
-
-                void postvisit( const ast::MemberExpr * memberExpr ) {
-                        addCandidate( memberExpr, tenv );
-                }
-
-                void postvisit( const ast::NameExpr * nameExpr ) {
-                        std::vector< ast::SymbolTable::IdData > declList;
-                        if (!selfFinder.otypeKeys.empty()) {
-                                auto kind = ast::SymbolTable::getSpecialFunctionKind(nameExpr->name);
-                                assertf(kind != ast::SymbolTable::SpecialFunctionKind::NUMBER_OF_KINDS, "special lookup with non-special target: %s", nameExpr->name.c_str());
-
-                                for (auto & otypeKey: selfFinder.otypeKeys) {
-                                        auto result = symtab.specialLookupId(kind, otypeKey);
-                                        declList.insert(declList.end(), std::make_move_iterator(result.begin()), std::make_move_iterator(result.end()));
-                                }
-                        }
-                        else {
-                                declList = symtab.lookupId( nameExpr->name );
-                        }
-                        PRINT( std::cerr << "nameExpr is " << nameExpr->name << std::endl; )
-
-                        if( declList.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        for ( auto & data : declList ) {
-                                Cost cost = Cost::zero;
-                                ast::Expr * newExpr = data.combine( nameExpr->location, cost );
-
-                                CandidateRef newCand = std::make_shared<Candidate>(
-                                        newExpr, copy( tenv ), ast::OpenVarSet{}, ast::AssertionSet{}, Cost::zero,
-                                        cost );
-
-                                if (newCand->expr->env) {
-                                        newCand->env.add(*newCand->expr->env);
-                                        auto mutExpr = newCand->expr.get_and_mutate();
-                                        mutExpr->env  = nullptr;
-                                        newCand->expr = mutExpr;
-                                }
-
-                                PRINT(
-                                        std::cerr << "decl is ";
-                                        ast::print( std::cerr, data.id );
-                                        std::cerr << std::endl;
-                                        std::cerr << "newExpr is ";
-                                        ast::print( std::cerr, newExpr );
-                                        std::cerr << std::endl;
-                                )
-                                newCand->expr = ast::mutate_field(
-                                        newCand->expr.get(), &ast::Expr::result,
-                                        renameTyVars( newCand->expr->result ) );
-                                // add anonymous member interpretations whenever an aggregate value type is seen
-                                // as a name expression
-                                addAnonConversions( newCand );
-                                candidates.emplace_back( std::move( newCand ) );
-                        }
-                }
-
-                void postvisit( const ast::VariableExpr * variableExpr ) {
-                        // not sufficient to just pass `variableExpr` here, type might have changed since
-                        // creation
-                        addCandidate(
-                                new ast::VariableExpr{ variableExpr->location, variableExpr->var }, tenv );
-                }
-
-                void postvisit( const ast::ConstantExpr * constantExpr ) {
-                        addCandidate( constantExpr, tenv );
-                }
-
-                void postvisit( const ast::SizeofExpr * sizeofExpr ) {
-                        if ( sizeofExpr->type ) {
-                                addCandidate(
-                                        new ast::SizeofExpr{
-                                                sizeofExpr->location, resolveTypeof( sizeofExpr->type, context ) },
-                                        tenv );
-                        } else {
-                                // find all candidates for the argument to sizeof
-                                CandidateFinder finder( context, tenv );
-                                finder.find( sizeofExpr->expr );
-                                // find the lowest-cost candidate, otherwise ambiguous
-                                CandidateList winners = findMinCost( finder.candidates );
-                                if ( winners.size() != 1 ) {
-                                        SemanticError(
-                                                sizeofExpr->expr.get(), "Ambiguous expression in sizeof operand: " );
-                                }
-                                // return the lowest-cost candidate
-                                CandidateRef & choice = winners.front();
-                                choice->expr = referenceToRvalueConversion( choice->expr, choice->cost );
-                                choice->cost = Cost::zero;
-                                addCandidate( *choice, new ast::SizeofExpr{ sizeofExpr->location, choice->expr } );
-                        }
-                }
-
-                void postvisit( const ast::AlignofExpr * alignofExpr ) {
-                        if ( alignofExpr->type ) {
-                                addCandidate(
-                                        new ast::AlignofExpr{
-                                                alignofExpr->location, resolveTypeof( alignofExpr->type, context ) },
-                                        tenv );
-                        } else {
-                                // find all candidates for the argument to alignof
-                                CandidateFinder finder( context, tenv );
-                                finder.find( alignofExpr->expr );
-                                // find the lowest-cost candidate, otherwise ambiguous
-                                CandidateList winners = findMinCost( finder.candidates );
-                                if ( winners.size() != 1 ) {
-                                        SemanticError(
-                                                alignofExpr->expr.get(), "Ambiguous expression in alignof operand: " );
-                                }
-                                // return the lowest-cost candidate
-                                CandidateRef & choice = winners.front();
-                                choice->expr = referenceToRvalueConversion( choice->expr, choice->cost );
-                                choice->cost = Cost::zero;
-                                addCandidate(
-                                        *choice, new ast::AlignofExpr{ alignofExpr->location, choice->expr } );
-                        }
-                }
-
-                void postvisit( const ast::UntypedOffsetofExpr * offsetofExpr ) {
-                        const ast::BaseInstType * aggInst;
-                        if (( aggInst = offsetofExpr->type.as< ast::StructInstType >() )) ;
-                        else if (( aggInst = offsetofExpr->type.as< ast::UnionInstType >() )) ;
-                        else return;
-
-                        for ( const ast::Decl * member : aggInst->lookup( offsetofExpr->member ) ) {
-                                auto dwt = strict_dynamic_cast< const ast::DeclWithType * >( member );
-                                addCandidate(
-                                        new ast::OffsetofExpr{ offsetofExpr->location, aggInst, dwt }, tenv );
-                        }
-                }
-
-                void postvisit( const ast::OffsetofExpr * offsetofExpr ) {
-                        addCandidate( offsetofExpr, tenv );
-                }
-
-                void postvisit( const ast::OffsetPackExpr * offsetPackExpr ) {
-                        addCandidate( offsetPackExpr, tenv );
-                }
-
-                void postvisit( const ast::LogicalExpr * logicalExpr ) {
-                        CandidateFinder finder1( context, tenv );
-                        finder1.find( logicalExpr->arg1, ResolvMode::withAdjustment() );
-                        if ( finder1.candidates.empty() ) return;
-
-                        CandidateFinder finder2( context, tenv );
-                        finder2.find( logicalExpr->arg2, ResolvMode::withAdjustment() );
-                        if ( finder2.candidates.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        for ( const CandidateRef & r1 : finder1.candidates ) {
-                                for ( const CandidateRef & r2 : finder2.candidates ) {
-                                        ast::TypeEnvironment env{ r1->env };
-                                        env.simpleCombine( r2->env );
-                                        ast::OpenVarSet open{ r1->open };
-                                        mergeOpenVars( open, r2->open );
-                                        ast::AssertionSet need;
-                                        mergeAssertionSet( need, r1->need );
-                                        mergeAssertionSet( need, r2->need );
-
-                                        addCandidate(
-                                                new ast::LogicalExpr{
-                                                        logicalExpr->location, r1->expr, r2->expr, logicalExpr->isAnd },
-                                                std::move( env ), std::move( open ), std::move( need ), r1->cost + r2->cost );
-                                }
-                        }
-                }
-
-                void postvisit( const ast::ConditionalExpr * conditionalExpr ) {
-                        // candidates for condition
-                        CandidateFinder finder1( context, tenv );
-                        finder1.find( conditionalExpr->arg1, ResolvMode::withAdjustment() );
-                        if ( finder1.candidates.empty() ) return;
-
-                        // candidates for true result
-                        CandidateFinder finder2( context, tenv );
-                        finder2.find( conditionalExpr->arg2, ResolvMode::withAdjustment() );
-                        if ( finder2.candidates.empty() ) return;
-
-                        // candidates for false result
-                        CandidateFinder finder3( context, tenv );
-                        finder3.find( conditionalExpr->arg3, ResolvMode::withAdjustment() );
-                        if ( finder3.candidates.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        for ( const CandidateRef & r1 : finder1.candidates ) {
-                                for ( const CandidateRef & r2 : finder2.candidates ) {
-                                        for ( const CandidateRef & r3 : finder3.candidates ) {
-                                                ast::TypeEnvironment env{ r1->env };
-                                                env.simpleCombine( r2->env );
-                                                env.simpleCombine( r3->env );
-                                                ast::OpenVarSet open{ r1->open };
-                                                mergeOpenVars( open, r2->open );
-                                                mergeOpenVars( open, r3->open );
-                                                ast::AssertionSet need;
-                                                mergeAssertionSet( need, r1->need );
-                                                mergeAssertionSet( need, r2->need );
-                                                mergeAssertionSet( need, r3->need );
-                                                ast::AssertionSet have;
-
-                                                // unify true and false results, then infer parameters to produce new
-                                                // candidates
-                                                ast::ptr< ast::Type > common;
-                                                if (
-                                                        unify(
-                                                                r2->expr->result, r3->expr->result, env, need, have, open, symtab,
-                                                                common )
-                                                ) {
-                                                        // generate typed expression
-                                                        ast::ConditionalExpr * newExpr = new ast::ConditionalExpr{
-                                                                conditionalExpr->location, r1->expr, r2->expr, r3->expr };
-                                                        newExpr->result = common ? common : r2->expr->result;
-                                                        // convert both options to result type
-                                                        Cost cost = r1->cost + r2->cost + r3->cost;
-                                                        newExpr->arg2 = computeExpressionConversionCost(
-                                                                newExpr->arg2, newExpr->result, symtab, env, cost );
-                                                        newExpr->arg3 = computeExpressionConversionCost(
-                                                                newExpr->arg3, newExpr->result, symtab, env, cost );
-                                                        // output candidate
-                                                        CandidateRef newCand = std::make_shared<Candidate>(
-                                                                newExpr, std::move( env ), std::move( open ), std::move( need ), cost );
-                                                        inferParameters( newCand, candidates );
-                                                }
-                                        }
-                                }
-                        }
-                }
-
-                void postvisit( const ast::CommaExpr * commaExpr ) {
-                        ast::TypeEnvironment env{ tenv };
-                        ast::ptr< ast::Expr > arg1 = resolveInVoidContext( commaExpr->arg1, context, env );
-
-                        CandidateFinder finder2( context, env );
-                        finder2.find( commaExpr->arg2, ResolvMode::withAdjustment() );
-
-                        for ( const CandidateRef & r2 : finder2.candidates ) {
-                                addCandidate( *r2, new ast::CommaExpr{ commaExpr->location, arg1, r2->expr } );
-                        }
-                }
-
-                void postvisit( const ast::ImplicitCopyCtorExpr * ctorExpr ) {
-                        addCandidate( ctorExpr, tenv );
-                }
-
-                void postvisit( const ast::ConstructorExpr * ctorExpr ) {
-                        CandidateFinder finder( context, tenv );
-                        finder.find( ctorExpr->callExpr, ResolvMode::withoutPrune() );
-                        for ( CandidateRef & r : finder.candidates ) {
-                                addCandidate( *r, new ast::ConstructorExpr{ ctorExpr->location, r->expr } );
-                        }
-                }
-
-                void postvisit( const ast::RangeExpr * rangeExpr ) {
-                        // resolve low and high, accept candidates where low and high types unify
-                        CandidateFinder finder1( context, tenv );
-                        finder1.find( rangeExpr->low, ResolvMode::withAdjustment() );
-                        if ( finder1.candidates.empty() ) return;
-
-                        CandidateFinder finder2( context, tenv );
-                        finder2.find( rangeExpr->high, ResolvMode::withAdjustment() );
-                        if ( finder2.candidates.empty() ) return;
-
-                        reason.code = NoMatch;
-
-                        for ( const CandidateRef & r1 : finder1.candidates ) {
-                                for ( const CandidateRef & r2 : finder2.candidates ) {
-                                        ast::TypeEnvironment env{ r1->env };
-                                        env.simpleCombine( r2->env );
-                                        ast::OpenVarSet open{ r1->open };
-                                        mergeOpenVars( open, r2->open );
-                                        ast::AssertionSet need;
-                                        mergeAssertionSet( need, r1->need );
-                                        mergeAssertionSet( need, r2->need );
-                                        ast::AssertionSet have;
-
-                                        ast::ptr< ast::Type > common;
-                                        if (
-                                                unify(
-                                                        r1->expr->result, r2->expr->result, env, need, have, open, symtab,
-                                                        common )
-                                        ) {
-                                                // generate new expression
-                                                ast::RangeExpr * newExpr =
-                                                        new ast::RangeExpr{ rangeExpr->location, r1->expr, r2->expr };
-                                                newExpr->result = common ? common : r1->expr->result;
-                                                // add candidate
-                                                CandidateRef newCand = std::make_shared<Candidate>(
-                                                        newExpr, std::move( env ), std::move( open ), std::move( need ),
-                                                        r1->cost + r2->cost );
-                                                inferParameters( newCand, candidates );
-                                        }
-                                }
-                        }
-                }
-
-                void postvisit( const ast::UntypedTupleExpr * tupleExpr ) {
-                        std::vector< CandidateFinder > subCandidates =
-                                selfFinder.findSubExprs( tupleExpr->exprs );
-                        std::vector< CandidateList > possibilities;
-                        combos( subCandidates.begin(), subCandidates.end(), back_inserter( possibilities ) );
-
-                        for ( const CandidateList & subs : possibilities ) {
-                                std::vector< ast::ptr< ast::Expr > > exprs;
-                                exprs.reserve( subs.size() );
-                                for ( const CandidateRef & sub : subs ) { exprs.emplace_back( sub->expr ); }
-
-                                ast::TypeEnvironment env;
-                                ast::OpenVarSet open;
-                                ast::AssertionSet need;
-                                for ( const CandidateRef & sub : subs ) {
-                                        env.simpleCombine( sub->env );
-                                        mergeOpenVars( open, sub->open );
-                                        mergeAssertionSet( need, sub->need );
-                                }
-
-                                addCandidate(
-                                        new ast::TupleExpr{ tupleExpr->location, std::move( exprs ) },
-                                        std::move( env ), std::move( open ), std::move( need ), sumCost( subs ) );
-                        }
-                }
-
-                void postvisit( const ast::TupleExpr * tupleExpr ) {
-                        addCandidate( tupleExpr, tenv );
-                }
-
-                void postvisit( const ast::TupleIndexExpr * tupleExpr ) {
-                        addCandidate( tupleExpr, tenv );
-                }
-
-                void postvisit( const ast::TupleAssignExpr * tupleExpr ) {
-                        addCandidate( tupleExpr, tenv );
-                }
-
-                void postvisit( const ast::UniqueExpr * unqExpr ) {
-                        CandidateFinder finder( context, tenv );
-                        finder.find( unqExpr->expr, ResolvMode::withAdjustment() );
-                        for ( CandidateRef & r : finder.candidates ) {
-                                // ensure that the the id is passed on so that the expressions are "linked"
-                                addCandidate( *r, new ast::UniqueExpr{ unqExpr->location, r->expr, unqExpr->id } );
-                        }
-                }
-
-                void postvisit( const ast::StmtExpr * stmtExpr ) {
-                        addCandidate( resolveStmtExpr( stmtExpr, context ), tenv );
-                }
-
-                void postvisit( const ast::UntypedInitExpr * initExpr ) {
-                        // handle each option like a cast
-                        CandidateList matches;
-                        PRINT(
-                                std::cerr << "untyped init expr: " << initExpr << std::endl;
-                        )
-                        // O(n^2) checks of d-types with e-types
-                        for ( const ast::InitAlternative & initAlt : initExpr->initAlts ) {
-                                // calculate target type
-                                const ast::Type * toType = resolveTypeof( initAlt.type, context );
-                                toType = adjustExprType( toType, tenv, symtab );
-                                // The call to find must occur inside this loop, otherwise polymorphic return
-                                // types are not bound to the initialization type, since return type variables are
-                                // only open for the duration of resolving the UntypedExpr.
-                                CandidateFinder finder( context, tenv, toType );
-                                finder.find( initExpr->expr, ResolvMode::withAdjustment() );
-                                for ( CandidateRef & cand : finder.candidates ) {
-                                        if(reason.code == NotFound) reason.code = NoMatch;
-
-                                        ast::TypeEnvironment env{ cand->env };
-                                        ast::AssertionSet need( cand->need.begin(), cand->need.end() ), have;
-                                        ast::OpenVarSet open{ cand->open };
-
-                                        PRINT(
-                                                std::cerr << "  @ " << toType << " " << initAlt.designation << std::endl;
-                                        )
-
-                                        // It is possible that a cast can throw away some values in a multiply-valued
-                                        // expression, e.g. cast-to-void, one value to zero. Figure out the prefix of
-                                        // the subexpression results that are cast directly. The candidate is invalid
-                                        // if it has fewer results than there are types to cast to.
-                                        int discardedValues = cand->expr->result->size() - toType->size();
-                                        if ( discardedValues < 0 ) continue;
-
-                                        // unification run for side-effects
-                                        bool canUnify = unify( toType, cand->expr->result, env, need, have, open, symtab );
-                                        (void) canUnify;
-                                        Cost thisCost = computeConversionCost( cand->expr->result, toType, cand->expr->get_lvalue(),
-                                                symtab, env );
-                                        PRINT(
-                                                Cost legacyCost = castCost( cand->expr->result, toType, cand->expr->get_lvalue(),
-                                                        symtab, env );
-                                                std::cerr << "Considering initialization:";
-                                                std::cerr << std::endl << "  FROM: " << cand->expr->result << std::endl;
-                                                std::cerr << std::endl << "  TO: "   << toType             << std::endl;
-                                                std::cerr << std::endl << "  Unification " << (canUnify ? "succeeded" : "failed");
-                                                std::cerr << std::endl << "  Legacy cost " << legacyCost;
-                                                std::cerr << std::endl << "  New cost " << thisCost;
-                                                std::cerr << std::endl;
-                                        )
-                                        if ( thisCost != Cost::infinity ) {
-                                                // count one safe conversion for each value that is thrown away
-                                                thisCost.incSafe( discardedValues );
-                                                CandidateRef newCand = std::make_shared<Candidate>(
-                                                        new ast::InitExpr{
-                                                                initExpr->location, restructureCast( cand->expr, toType ),
-                                                                initAlt.designation },
-                                                        std::move(env), std::move( open ), std::move( need ), cand->cost, thisCost );
-                                                inferParameters( newCand, matches );
-                                        }
-                                }
-
-                        }
-
-                        // select first on argument cost, then conversion cost
-                        CandidateList minArgCost = findMinCost( matches );
-                        promoteCvtCost( minArgCost );
-                        candidates = findMinCost( minArgCost );
-                }
-
-                void postvisit( const ast::InitExpr * ) {
-                        assertf( false, "CandidateFinder should never see a resolved InitExpr." );
-                }
-
-                void postvisit( const ast::DeletedExpr * ) {
-                        assertf( false, "CandidateFinder should never see a DeletedExpr." );
-                }
-
-                void postvisit( const ast::GenericExpr * ) {
-                        assertf( false, "_Generic is not yet supported." );
-                }
-        };
-
-        // size_t Finder::traceId = Stats::Heap::new_stacktrace_id("Finder");
-        /// Prunes a list of candidates down to those that have the minimum conversion cost for a given
-        /// return type. Skips ambiguous candidates.
-
-} // anonymous namespace
-
-bool CandidateFinder::pruneCandidates( CandidateList & candidates, CandidateList & out, std::vector<std::string> & errors ) {
-        struct PruneStruct {
-                CandidateRef candidate;
-                bool ambiguous;
-
-                PruneStruct() = default;
-                PruneStruct( const CandidateRef & c ) : candidate( c ), ambiguous( false ) {}
-        };
-
-        // find lowest-cost candidate for each type
-        std::unordered_map< std::string, PruneStruct > selected;
-        // attempt to skip satisfyAssertions on more expensive alternatives if better options have been found
-        std::sort(candidates.begin(), candidates.end(), [](const CandidateRef & x, const CandidateRef & y){return x->cost < y->cost;});
-        for ( CandidateRef & candidate : candidates ) {
-                std::string mangleName;
-                {
-                        ast::ptr< ast::Type > newType = candidate->expr->result;
-                        assertf(candidate->expr->result, "Result of expression %p for candidate is null", candidate->expr.get());
-                        candidate->env.apply( newType );
-                        mangleName = Mangle::mangle( newType );
-                }
-
-                auto found = selected.find( mangleName );
-                if (found != selected.end() && found->second.candidate->cost < candidate->cost) {
-                        PRINT(
-                                std::cerr << "cost " << candidate->cost << " loses to "
-                                        << found->second.candidate->cost << std::endl;
-                        )
-                        continue;
-                }
-
-                // xxx - when do satisfyAssertions produce more than 1 result?
-                // this should only happen when initial result type contains
-                // unbound type parameters, then it should never be pruned by
-                // the previous step, since renameTyVars guarantees the mangled name
-                // is unique.
-                CandidateList satisfied;
-                bool needRecomputeKey = false;
-                if (candidate->need.empty()) {
-                        satisfied.emplace_back(candidate);
-                }
-                else {
-                        satisfyAssertions(candidate, context.symtab, satisfied, errors);
-                        needRecomputeKey = true;
-                }
-
-                for (auto & newCand : satisfied) {
-                        // recomputes type key, if satisfyAssertions changed it
-                        if (needRecomputeKey)
-                        {
-                                ast::ptr< ast::Type > newType = newCand->expr->result;
-                                assertf(newCand->expr->result, "Result of expression %p for candidate is null", newCand->expr.get());
-                                newCand->env.apply( newType );
-                                mangleName = Mangle::mangle( newType );
-                        }
-                        auto found = selected.find( mangleName );
-                        if ( found != selected.end() ) {
-                                if ( newCand->cost < found->second.candidate->cost ) {
-                                        PRINT(
-                                                std::cerr << "cost " << newCand->cost << " beats "
-                                                        << found->second.candidate->cost << std::endl;
-                                        )
-
-                                        found->second = PruneStruct{ newCand };
-                                } else if ( newCand->cost == found->second.candidate->cost ) {
-                                        // if one of the candidates contains a deleted identifier, can pick the other,
-                                        // since deleted expressions should not be ambiguous if there is another option
-                                        // that is at least as good
-                                        if ( findDeletedExpr( newCand->expr ) ) {
-                                                // do nothing
-                                                PRINT( std::cerr << "candidate is deleted" << std::endl; )
-                                        } else if ( findDeletedExpr( found->second.candidate->expr ) ) {
-                                                PRINT( std::cerr << "current is deleted" << std::endl; )
-                                                found->second = PruneStruct{ newCand };
-                                        } else {
-                                                PRINT( std::cerr << "marking ambiguous" << std::endl; )
-                                                found->second.ambiguous = true;
-                                        }
-                                } else {
-                                        // xxx - can satisfyAssertions increase the cost?
-                                        PRINT(
-                                                std::cerr << "cost " << newCand->cost << " loses to "
-                                                        << found->second.candidate->cost << std::endl;
-                                        )
-                                }
-                        } else {
-                                selected.emplace_hint( found, mangleName, newCand );
-                        }
-                }
-        }
-
-        // report unambiguous min-cost candidates
-        // CandidateList out;
-        for ( auto & target : selected ) {
-                if ( target.second.ambiguous ) continue;
-
-                CandidateRef cand = target.second.candidate;
-
-                ast::ptr< ast::Type > newResult = cand->expr->result;
-                cand->env.applyFree( newResult );
-                cand->expr = ast::mutate_field(
-                        cand->expr.get(), &ast::Expr::result, std::move( newResult ) );
-
-                out.emplace_back( cand );
-        }
-        // if everything is lost in satisfyAssertions, report the error
-        return !selected.empty();
-}
-
-void CandidateFinder::find( const ast::Expr * expr, ResolvMode mode ) {
-        // Find alternatives for expression
-        ast::Pass<Finder> finder{ *this };
-        expr->accept( finder );
-
-        if ( mode.failFast && candidates.empty() ) {
-                switch(finder.core.reason.code) {
-                case Finder::NotFound:
-                        { SemanticError( expr, "No alternatives for expression " ); break; }
-                case Finder::NoMatch:
-                        { SemanticError( expr, "Invalid application of existing declaration(s) in expression " ); break; }
-                case Finder::ArgsToFew:
-                case Finder::ArgsToMany:
-                case Finder::RetsToFew:
-                case Finder::RetsToMany:
-                case Finder::NoReason:
-                default:
-                        { SemanticError( expr->location, "No reasonable alternatives for expression : reasons unkown" ); }
-                }
-        }
-
-        /*
-        if ( mode.satisfyAssns || mode.prune ) {
-                // trim candidates to just those where the assertions are satisfiable
-                // - necessary pre-requisite to pruning
-                CandidateList satisfied;
-                std::vector< std::string > errors;
-                for ( CandidateRef & candidate : candidates ) {
-                        satisfyAssertions( candidate, localSyms, satisfied, errors );
-                }
-
-                // fail early if none such
-                if ( mode.failFast && satisfied.empty() ) {
-                        std::ostringstream stream;
-                        stream << "No alternatives with satisfiable assertions for " << expr << "\n";
-                        for ( const auto& err : errors ) {
-                                stream << err;
-                        }
-                        SemanticError( expr->location, stream.str() );
-                }
-
-                // reset candidates
-                candidates = move( satisfied );
-        }
-        */
-
-        if ( mode.prune ) {
-                // trim candidates to single best one
-                PRINT(
-                        std::cerr << "alternatives before prune:" << std::endl;
-                        print( std::cerr, candidates );
-                )
-
-                CandidateList pruned;
-                std::vector<std::string> errors;
-                bool found = pruneCandidates( candidates, pruned, errors );
-
-                if ( mode.failFast && pruned.empty() ) {
-                        std::ostringstream stream;
-                        if (found) {
-                                CandidateList winners = findMinCost( candidates );
-                                stream << "Cannot choose between " << winners.size() << " alternatives for "
-                                        "expression\n";
-                                ast::print( stream, expr );
-                                stream << " Alternatives are:\n";
-                                print( stream, winners, 1 );
-                                SemanticError( expr->location, stream.str() );
-                        }
-                        else {
-                                stream << "No alternatives with satisfiable assertions for " << expr << "\n";
-                                for ( const auto& err : errors ) {
-                                        stream << err;
-                                }
-                                SemanticError( expr->location, stream.str() );
-                        }
-                }
-
-                auto oldsize = candidates.size();
-                candidates = std::move( pruned );
-
-                PRINT(
-                        std::cerr << "there are " << oldsize << " alternatives before elimination" << std::endl;
-                )
-                PRINT(
-                        std::cerr << "there are " << candidates.size() << " alternatives after elimination"
-                                << std::endl;
-                )
-        }
-
-        // adjust types after pruning so that types substituted by pruneAlternatives are correctly
-        // adjusted
-        if ( mode.adjust ) {
-                for ( CandidateRef & r : candidates ) {
-                        r->expr = ast::mutate_field(
-                                r->expr.get(), &ast::Expr::result,
-                                adjustExprType( r->expr->result, r->env, context.symtab ) );
-                }
-        }
-
-        // Central location to handle gcc extension keyword, etc. for all expressions
-        for ( CandidateRef & r : candidates ) {
-                if ( r->expr->extension != expr->extension ) {
-                        r->expr.get_and_mutate()->extension = expr->extension;
-                }
-        }
-}
-
-std::vector< CandidateFinder > CandidateFinder::findSubExprs(
-        const std::vector< ast::ptr< ast::Expr > > & xs
-) {
-        std::vector< CandidateFinder > out;
-
-        for ( const auto & x : xs ) {
-                out.emplace_back( context, env );
-                out.back().find( x, ResolvMode::withAdjustment() );
-
-                PRINT(
-                        std::cerr << "findSubExprs" << std::endl;
-                        print( std::cerr, out.back().candidates );
-                )
-        }
-
-        return out;
-}
-
 } // namespace ResolvExpr
 

src/ResolvExpr/CurrentObject.cc

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Tue Jun 13 15:28:32 2017
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Jul  1 09:16:01 2022
-// Update Count     : 15
+// Last Modified By : Andrew Beach
+// Last Modified On : Mon Apr 10  9:40:00 2023
+// Update Count     : 18
 //
 
@@ -593 +593 @@
 
 namespace ast {
+        /// Iterates members of a type by initializer.
+        class MemberIterator {
+        public:
+                virtual ~MemberIterator() {}
+
+                /// Internal set position based on iterator ranges.
+                virtual void setPosition(
+                        std::deque< ptr< Expr > >::const_iterator it,
+                        std::deque< ptr< Expr > >::const_iterator end ) = 0;
+
+                /// Walks the current object using the given designators as a guide.
+                void setPosition( const std::deque< ptr< Expr > > & designators ) {
+                        setPosition( designators.begin(), designators.end() );
+                }
+
+                /// Retrieve the list of possible (Type,Designation) pairs for the
+                /// current position in the current object.
+                virtual std::deque< InitAlternative > operator* () const = 0;
+
+                /// True if the iterator is not currently at the end.
+                virtual operator bool() const = 0;
+
+                /// Moves the iterator by one member in the current object.
+                virtual MemberIterator & bigStep() = 0;
+
+                /// Moves the iterator by one member in the current subobject.
+                virtual MemberIterator & smallStep() = 0;
+
+                /// The type of the current object.
+                virtual const Type * getType() = 0;
+
+                /// The type of the current subobject.
+                virtual const Type * getNext() = 0;
+
+                /// Helper for operator*; aggregates must add designator to each init
+                /// alternative, but adding designators in operator* creates duplicates.
+                virtual std::deque< InitAlternative > first() const = 0;
+        };
+
         /// create a new MemberIterator that traverses a type correctly
         MemberIterator * createMemberIterator( const CodeLocation & loc, const Type * type );
@@ -632 +671 @@
         };
 
-        /// Iterates array types
-        class ArrayIterator final : public MemberIterator {
+        /// Iterates over an indexed type:
+        class IndexIterator : public MemberIterator {
+        protected:
                 CodeLocation location;
-                const ArrayType * array = nullptr;
-                const Type * base = nullptr;
                 size_t index = 0;
                 size_t size = 0;
-                std::unique_ptr< MemberIterator > memberIter;
-
-                void setSize( const Expr * expr ) {
-                        auto res = eval( expr );
-                        if ( ! res.second ) {
-                                SemanticError( location, toString( "Array designator must be a constant expression: ", expr ) );
-                        }
-                        size = res.first;
-                }
-
-        public:
-                ArrayIterator( const CodeLocation & loc, const ArrayType * at ) : location( loc ), array( at ), base( at->base ) {
-                        PRINT( std::cerr << "Creating array iterator: " << at << std::endl; )
-                        memberIter.reset( createMemberIterator( loc, base ) );
-                        if ( at->isVarLen ) {
-                                SemanticError( location, at, "VLA initialization does not support @=: " );
-                        }
-                        setSize( at->dimension );
-                }
+                std::unique_ptr<MemberIterator> memberIter;
+        public:
+                IndexIterator( const CodeLocation & loc, size_t size ) :
+                        location( loc ), size( size )
+                {}
 
                 void setPosition( const Expr * expr ) {
@@ -666 +690 @@
                         auto arg = eval( expr );
                         index = arg.first;
-                        return;
 
                         // if ( auto constExpr = dynamic_cast< const ConstantExpr * >( expr ) ) {
@@ -684 +707 @@
 
                 void setPosition(
-                        std::deque< ptr< Expr > >::const_iterator begin,
-                        std::deque< ptr< Expr > >::const_iterator end
+                        std::deque<ast::ptr<ast::Expr>>::const_iterator begin,
+                        std::deque<ast::ptr<ast::Expr>>::const_iterator end
                 ) override {
                         if ( begin == end ) return;
@@ -696 +719 @@
 
                 operator bool() const override { return index < size; }
+        };
+
+        /// Iterates over the members of array types:
+        class ArrayIterator final : public IndexIterator {
+                const ArrayType * array = nullptr;
+                const Type * base = nullptr;
+
+                size_t getSize( const Expr * expr ) {
+                        auto res = eval( expr );
+                        if ( !res.second ) {
+                                SemanticError( location, toString( "Array designator must be a constant expression: ", expr ) );
+                        }
+                        return res.first;
+                }
+
+        public:
+                ArrayIterator( const CodeLocation & loc, const ArrayType * at ) :
+                                IndexIterator( loc, getSize( at->dimension) ),
+                                array( at ), base( at->base ) {
+                        PRINT( std::cerr << "Creating array iterator: " << at << std::endl; )
+                        memberIter.reset( createMemberIterator( loc, base ) );
+                        if ( at->isVarLen ) {
+                                SemanticError( location, at, "VLA initialization does not support @=: " );
+                        }
+                }
 
                 ArrayIterator & bigStep() override {
@@ -834 +882 @@
 
                 const Type * getNext() final {
-                        return ( memberIter && *memberIter ) ? memberIter->getType() : nullptr;
+                        bool hasMember = memberIter && *memberIter;
+                        return hasMember ? memberIter->getType() : nullptr;
                 }
 
@@ -898 +947 @@
         };
 
-        class TupleIterator final : public AggregateIterator {
-        public:
-                TupleIterator( const CodeLocation & loc, const TupleType * inst )
-                : AggregateIterator(
-                        loc, "TupleIterator", toString("Tuple", inst->size()), inst, inst->members
-                ) {}
-
-                operator bool() const override {
-                        return curMember != members.end() || (memberIter && *memberIter);
+        /// Iterates across the positions in a tuple:
+        class TupleIterator final : public IndexIterator {
+                ast::TupleType const * const tuple;
+
+                const ast::Type * typeAtIndex() const {
+                        assert( index < size );
+                        return tuple->types[ index ].get();
+                }
+
+        public:
+                TupleIterator( const CodeLocation & loc, const TupleType * type )
+                : IndexIterator( loc, type->size() ), tuple( type ) {
+                        PRINT( std::cerr << "Creating tuple iterator: " << type << std::endl; )
+                        memberIter.reset( createMemberIterator( loc, typeAtIndex() ) );
                 }
 
                 TupleIterator & bigStep() override {
-                        PRINT( std::cerr << "bigStep in " << kind << std::endl; )
-                        atbegin = false;
-                        memberIter = nullptr;
-                        curType = nullptr;
-                        while ( curMember != members.end() ) {
-                                ++curMember;
-                                if ( init() ) return *this;
-                        }
+                        ++index;
+                        memberIter.reset( index < size ?
+                                createMemberIterator( location, typeAtIndex() ) : nullptr );
                         return *this;
+                }
+
+                TupleIterator & smallStep() override {
+                        if ( memberIter ) {
+                                PRINT( std::cerr << "has member iter: " << *memberIter << std::endl; )
+                                memberIter->smallStep();
+                                if ( !memberIter ) {
+                                        PRINT( std::cerr << "has valid member iter" << std::endl; )
+                                        return *this;
+                                }
+                        }
+                        return bigStep();
+                }
+
+                const ast::Type * getType() override {
+                        return tuple;
+                }
+
+                const ast::Type * getNext() override {
+                        bool hasMember = memberIter && *memberIter;
+                        return hasMember ? memberIter->getType() : nullptr;
+                }
+
+                std::deque< InitAlternative > first() const override {
+                        PRINT( std::cerr << "first in TupleIterator (" << index << "/" << size << ")" << std::endl; )
+                        if ( memberIter && *memberIter ) {
+                                std::deque< InitAlternative > ret = memberIter->first();
+                                for ( InitAlternative & alt : ret ) {
+                                        alt.designation.get_and_mutate()->designators.emplace_front(
+                                                ConstantExpr::from_ulong( location, index ) );
+                                }
+                                return ret;
+                        }
+                        return {};
                 }
         };

src/ResolvExpr/CurrentObject.h

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Thu Jun  8 11:07:25 2017
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Sat Jul 22 09:36:48 2017
-// Update Count     : 3
+// Last Modified By : Andrew Beach
+// Last Modified On : Thu Apr  6 16:14:00 2023
+// Update Count     : 4
 //
 
@@ -65 +65 @@
 
         /// Iterates members of a type by initializer
-        class MemberIterator {
-        public:
-                virtual ~MemberIterator() {}
-
-                /// Internal set position based on iterator ranges
-                virtual void setPosition( 
-                        std::deque< ptr< Expr > >::const_iterator it, 
-                        std::deque< ptr< Expr > >::const_iterator end ) = 0;
-
-                /// walks the current object using the given designators as a guide
-                void setPosition( const std::deque< ptr< Expr > > & designators ) {
-                        setPosition( designators.begin(), designators.end() );
-                }
-
-                /// retrieve the list of possible (Type,Designation) pairs for the current position in the 
-                /// current object
-                virtual std::deque< InitAlternative > operator* () const = 0;
-
-                /// true if the iterator is not currently at the end
-                virtual operator bool() const = 0;
-
-                /// moves the iterator by one member in the current object
-                virtual MemberIterator & bigStep() = 0;
-
-                /// moves the iterator by one member in the current subobject
-                virtual MemberIterator & smallStep() = 0;
-
-                /// the type of the current object
-                virtual const Type * getType() = 0;
-
-                /// the type of the current subobject
-                virtual const Type * getNext() = 0;
-        
-                /// helper for operator*; aggregates must add designator to each init alternative, but 
-                /// adding designators in operator* creates duplicates
-                virtual std::deque< InitAlternative > first() const = 0;
-        };
+        class MemberIterator;
 
         /// Builds initializer lists in resolution

src/ResolvExpr/ExplodedArg.hpp

@@ -35 +35 @@
         ExplodedArg() : env(), cost( Cost::zero ), exprs() {}
         ExplodedArg( const Candidate & arg, const ast::SymbolTable & symtab );
-        
+
         ExplodedArg( ExplodedArg && ) = default;
         ExplodedArg & operator= ( ExplodedArg && ) = default;

src/SymTab/Autogen.cc

@@ -10 +10 @@
 // Created On       : Thu Mar 03 15:45:56 2016
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Apr 27 14:39:06 2018
-// Update Count     : 63
+// Last Modified On : Fri Apr 14 15:03:00 2023
+// Update Count     : 64
 //
 
@@ -211 +211 @@
         }
 
-        bool isUnnamedBitfield( const ast::ObjectDecl * obj ) {
-                return obj && obj->name.empty() && obj->bitfieldWidth;
-        }
-
         /// inserts a forward declaration for functionDecl into declsToAdd
         void addForwardDecl( FunctionDecl * functionDecl, std::list< Declaration * > & declsToAdd ) {
@@ -234 +230 @@
         }
 
-        // shallow copy the pointer list for return
-        std::vector<ast::ptr<ast::TypeDecl>> getGenericParams (const ast::Type * t) {
-                if (auto structInst = dynamic_cast<const ast::StructInstType*>(t)) {
-                        return structInst->base->params;
-                }
-                if (auto unionInst = dynamic_cast<const ast::UnionInstType*>(t)) {
-                        return unionInst->base->params;
-                }
-                return {};
-        }
-
         /// given type T, generate type of default ctor/dtor, i.e. function type void (*) (T *)
         FunctionType * genDefaultType( Type * paramType, bool maybePolymorphic ) {
@@ -256 +241 @@
                 ftype->parameters.push_back( dstParam );
                 return ftype;
-        }
-
-        /// Given type T, generate type of default ctor/dtor, i.e. function type void (*) (T &).
-        ast::FunctionDecl * genDefaultFunc(const CodeLocation loc, const std::string fname, const ast::Type * paramType, bool maybePolymorphic) {
-                std::vector<ast::ptr<ast::TypeDecl>> typeParams;
-                if (maybePolymorphic) typeParams = getGenericParams(paramType);
-                auto dstParam = new ast::ObjectDecl(loc, "_dst", new ast::ReferenceType(paramType), nullptr, {}, ast::Linkage::Cforall);
-                return new ast::FunctionDecl(loc, fname, std::move(typeParams), {dstParam}, {}, new ast::CompoundStmt(loc), {}, ast::Linkage::Cforall);
         }
 

src/SymTab/Autogen.h

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Sun May 17 21:53:34 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Dec 13 16:38:06 2019
-// Update Count     : 16
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Apr 14 15:06:00 2023
+// Update Count     : 17
 //
 
@@ -45 +45 @@
         /// returns true if obj's name is the empty string and it has a bitfield width
         bool isUnnamedBitfield( ObjectDecl * obj );
-        bool isUnnamedBitfield( const ast::ObjectDecl * obj );
 
         /// generate the type of an assignment function for paramType.
@@ -55 +54 @@
         FunctionType * genDefaultType( Type * paramType, bool maybePolymorphic = true );
 
-        ast::FunctionDecl * genDefaultFunc(const CodeLocation loc, const std::string fname, const ast::Type * paramType, bool maybePolymorphic = true);
-
         /// generate the type of a copy constructor for paramType.
         /// maybePolymorphic is true if the resulting FunctionType is allowed to be polymorphic
@@ -67 +64 @@
         template< typename OutputIterator >
         Statement * genCall( InitTweak::InitExpander_old & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, Type * type, Type * addCast = nullptr, bool forward = true );
-
-        template< typename OutIter >
-        ast::ptr< ast::Stmt > genCall(
-                InitTweak::InitExpander_new & srcParam, const ast::Expr * dstParam,
-                const CodeLocation & loc, const std::string & fname, OutIter && out,
-                const ast::Type * type, const ast::Type * addCast, LoopDirection forward = LoopForward );
 
         /// inserts into out a generated call expression to function fname with arguments dstParam and srcParam. Should only be called with non-array types.
@@ -121 +112 @@
 
                 *out++ = new ExprStmt( fExpr );
-
-                srcParam.clearArrayIndices();
-
-                return listInit;
-        }
-
-        /// inserts into out a generated call expression to function fname with arguments dstParam and
-        /// srcParam. Should only be called with non-array types.
-        /// optionally returns a statement which must be inserted prior to the containing loop, if
-        /// there is one
-        template< typename OutIter >
-        ast::ptr< ast::Stmt > genScalarCall(
-                InitTweak::InitExpander_new & srcParam, const ast::Expr * dstParam,
-                const CodeLocation & loc, std::string fname, OutIter && out, const ast::Type * type,
-                const ast::Type * addCast = nullptr
-        ) {
-                bool isReferenceCtorDtor = false;
-                if ( dynamic_cast< const ast::ReferenceType * >( type ) && CodeGen::isCtorDtor( fname ) ) {
-                        // reference constructors are essentially application of the rebind operator.
-                        // apply & to both arguments, do not need a cast
-                        fname = "?=?";
-                        dstParam = new ast::AddressExpr{ dstParam };
-                        addCast = nullptr;
-                        isReferenceCtorDtor = true;
-                }
-
-                // want to be able to generate assignment, ctor, and dtor generically, so fname is one of
-                // "?=?", "?{}", or "^?{}"
-                ast::UntypedExpr * fExpr = new ast::UntypedExpr{ loc, new ast::NameExpr{ loc, fname } };
-
-                if ( addCast ) {
-                        // cast to T& with qualifiers removed, so that qualified objects can be constructed and
-                        // destructed with the same functions as non-qualified objects. Unfortunately, lvalue
-                        // is considered a qualifier - for AddressExpr to resolve, its argument must have an
-                        // lvalue-qualified type, so remove all qualifiers except lvalue.
-                        // xxx -- old code actually removed lvalue too...
-                        ast::ptr< ast::Type > guard = addCast;  // prevent castType from mutating addCast
-                        ast::ptr< ast::Type > castType = addCast;
-                        ast::remove_qualifiers(
-                                castType,
-                                ast::CV::Const | ast::CV::Volatile | ast::CV::Restrict | ast::CV::Atomic );
-                        dstParam = new ast::CastExpr{ dstParam, new ast::ReferenceType{ castType } };
-                }
-                fExpr->args.emplace_back( dstParam );
-
-                ast::ptr<ast::Stmt> listInit = srcParam.buildListInit( fExpr );
-
-                // fetch next set of arguments
-                ++srcParam;
-
-                // return if adding reference fails -- will happen on default ctor and dtor
-                if ( isReferenceCtorDtor && ! srcParam.addReference() ) return listInit;
-
-                std::vector< ast::ptr< ast::Expr > > args = *srcParam;
-                splice( fExpr->args, args );
-
-                *out++ = new ast::ExprStmt{ loc, fExpr };
 
                 srcParam.clearArrayIndices();
@@ -248 +182 @@
         }
 
-        /// Store in out a loop which calls fname on each element of the array with srcParam and
-        /// dstParam as arguments. If forward is true, loop goes from 0 to N-1, else N-1 to 0
-        template< typename OutIter >
-        void genArrayCall(
-                InitTweak::InitExpander_new & srcParam, const ast::Expr * dstParam,
-                const CodeLocation & loc, const std::string & fname, OutIter && out,
-                const ast::ArrayType * array, const ast::Type * addCast = nullptr,
-                LoopDirection forward = LoopForward
-        ) {
-                static UniqueName indexName( "_index" );
-
-                // for a flexible array member nothing is done -- user must define own assignment
-                if ( ! array->dimension ) return;
-
-                if ( addCast ) {
-                        // peel off array layer from cast
-                        addCast = strict_dynamic_cast< const ast::ArrayType * >( addCast )->base;
-                }
-
-                ast::ptr< ast::Expr > begin, end;
-                std::string cmp, update;
-
-                if ( forward ) {
-                        // generate: for ( int i = 0; i < N; ++i )
-                        begin = ast::ConstantExpr::from_int( loc, 0 );
-                        end = array->dimension;
-                        cmp = "?<?";
-                        update = "++?";
-                } else {
-                        // generate: for ( int i = N-1; i >= 0; --i )
-                        begin = ast::UntypedExpr::createCall( loc, "?-?",
-                                { array->dimension, ast::ConstantExpr::from_int( loc, 1 ) } );
-                        end = ast::ConstantExpr::from_int( loc, 0 );
-                        cmp = "?>=?";
-                        update = "--?";
-                }
-
-                ast::ptr< ast::DeclWithType > index = new ast::ObjectDecl{
-                        loc, indexName.newName(), new ast::BasicType{ ast::BasicType::SignedInt },
-                        new ast::SingleInit{ loc, begin } };
-                ast::ptr< ast::Expr > indexVar = new ast::VariableExpr{ loc, index };
-
-                ast::ptr< ast::Expr > cond = ast::UntypedExpr::createCall(
-                        loc, cmp, { indexVar, end } );
-
-                ast::ptr< ast::Expr > inc = ast::UntypedExpr::createCall(
-                        loc, update, { indexVar } );
-
-                ast::ptr< ast::Expr > dstIndex = ast::UntypedExpr::createCall(
-                        loc, "?[?]", { dstParam, indexVar } );
-
-                // srcParam must keep track of the array indices to build the source parameter and/or
-                // array list initializer
-                srcParam.addArrayIndex( indexVar, array->dimension );
-
-                // for stmt's body, eventually containing call
-                ast::CompoundStmt * body = new ast::CompoundStmt{ loc };
-                ast::ptr< ast::Stmt > listInit = genCall(
-                        srcParam, dstIndex, loc, fname, std::back_inserter( body->kids ), array->base, addCast,
-                        forward );
-
-                // block containing the stmt and index variable
-                ast::CompoundStmt * block = new ast::CompoundStmt{ loc };
-                block->push_back( new ast::DeclStmt{ loc, index } );
-                if ( listInit ) { block->push_back( listInit ); }
-                block->push_back( new ast::ForStmt{ loc, {}, cond, inc, body } );
-
-                *out++ = block;
-        }
-
         template< typename OutputIterator >
         Statement * genCall( InitTweak::InitExpander_old & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, Type * type, Type * addCast, bool forward ) {
@@ -325 +189 @@
                 } else {
                         return genScalarCall( srcParam, dstParam, fname, out, type, addCast );
-                }
-        }
-
-        template< typename OutIter >
-        ast::ptr< ast::Stmt > genCall(
-                InitTweak::InitExpander_new & srcParam, const ast::Expr * dstParam,
-                const CodeLocation & loc, const std::string & fname, OutIter && out,
-                const ast::Type * type, const ast::Type * addCast, LoopDirection forward
-        ) {
-                if ( auto at = dynamic_cast< const ast::ArrayType * >( type ) ) {
-                        genArrayCall(
-                                srcParam, dstParam, loc, fname, std::forward< OutIter >(out), at, addCast,
-                                forward );
-                        return {};
-                } else {
-                        return genScalarCall(
-                                srcParam, dstParam, loc, fname, std::forward< OutIter >( out ), type, addCast );
                 }
         }
@@ -379 +226 @@
         }
 
-        static inline ast::ptr< ast::Stmt > genImplicitCall(
-                InitTweak::InitExpander_new & srcParam, const ast::Expr * dstParam,
-                const CodeLocation & loc, const std::string & fname, const ast::ObjectDecl * obj,
-                LoopDirection forward = LoopForward
-        ) {
-                // unnamed bit fields are not copied as they cannot be accessed
-                if ( isUnnamedBitfield( obj ) ) return {};
-
-                ast::ptr< ast::Type > addCast;
-                if ( (fname == "?{}" || fname == "^?{}") && ( ! obj || ( obj && ! obj->bitfieldWidth ) ) ) {
-                        assert( dstParam->result );
-                        addCast = dstParam->result;
-                }
-
-                std::vector< ast::ptr< ast::Stmt > > stmts;
-                genCall(
-                        srcParam, dstParam, loc, fname, back_inserter( stmts ), obj->type, addCast, forward );
-
-                if ( stmts.empty() ) {
-                        return {};
-                } else if ( stmts.size() == 1 ) {
-                        const ast::Stmt * callStmt = stmts.front();
-                        if ( addCast ) {
-                                // implicitly generated ctor/dtor calls should be wrapped so that later passes are
-                                // aware they were generated.
-                                callStmt = new ast::ImplicitCtorDtorStmt{ callStmt->location, callStmt };
-                        }
-                        return callStmt;
-                } else {
-                        assert( false );
-                        return {};
-                }
-        }
 } // namespace SymTab
 

src/SymTab/module.mk

@@ -20 +20 @@
         SymTab/FixFunction.cc \
         SymTab/FixFunction.h \
+        SymTab/GenImplicitCall.cpp \
+        SymTab/GenImplicitCall.hpp \
         SymTab/Indexer.cc \
         SymTab/Indexer.h \

src/Validate/Autogen.cpp

@@ -39 +39 @@
 #include "InitTweak/GenInit.h"     // for fixReturnStatements
 #include "InitTweak/InitTweak.h"   // for isAssignment, isCopyConstructor
+#include "SymTab/GenImplicitCall.hpp"  // for genImplicitCall
 #include "SymTab/Mangler.h"        // for Mangler
 #include "CompilationState.h"
@@ -423 +424 @@
         for ( unsigned int index = 0 ; index < fields ; ++index ) {
                 auto member = aggr->members[index].strict_as<ast::DeclWithType>();
-                if ( SymTab::isUnnamedBitfield(
+                if ( ast::isUnnamedBitfield(
                                 dynamic_cast<const ast::ObjectDecl *>( member ) ) ) {
                         if ( index == fields - 1 ) {
@@ -599 +600 @@
                 // Not sure why it could be null.
                 // Don't make a function for a parameter that is an unnamed bitfield.
-                if ( nullptr == field || SymTab::isUnnamedBitfield( field ) ) {
+                if ( nullptr == field || ast::isUnnamedBitfield( field ) ) {
                         continue;
                 // Matching Parameter: Initialize the field by copy.

src/main.cc

@@ -9 +9 @@
 // Author           : Peter Buhr and Rob Schluntz
 // Created On       : Fri May 15 23:12:02 2015
-// Last Modified By : Andrew Beach
-// Last Modified On : Thr Feb 16 10:08:00 2023
-// Update Count     : 680
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Mon Apr 10 21:12:17 2023
+// Update Count     : 682
 //
 
@@ -32 +32 @@
 
 #include "AST/Convert.hpp"
+#include "AST/Util.hpp"                     // for checkInvariants
 #include "CompilationState.h"
 #include "../config.h"                      // for CFA_LIBDIR
@@ -102 +103 @@
 }
 
-#define PASS( name, pass )                  \
+// Helpers for checkInvariant:
+void checkInvariants( std::list< Declaration * > & ) {}
+using ast::checkInvariants;
+
+#define PASS( name, pass, unit, ... )       \
         if ( errorp ) { cerr << name << endl; } \
         NewPass(name);                          \
         Stats::Time::StartBlock(name);          \
-        pass;                                   \
-        Stats::Time::StopBlock();
+        pass(unit,##__VA_ARGS__);               \
+        Stats::Time::StopBlock();               \
+        if ( invariant ) {                      \
+                checkInvariants(unit);              \
+        }
+
+#define DUMP( cond, unit )                  \
+        if ( cond ) {                           \
+                dump(unit);                         \
+                return EXIT_SUCCESS;                \
+        }
 
 static bool waiting_for_gdb = false;                                    // flag to set cfa-cpp to wait for gdb on start
@@ -298 +312 @@
                 transUnit = buildUnit();
 
-                if ( astp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
+                DUMP( astp, std::move( transUnit ) );
 
                 Stats::Time::StopBlock();
@@ -310 +321 @@
                 }
 
-                PASS( "Hoist Type Decls", Validate::hoistTypeDecls( transUnit ) );
-                // Hoist Type Decls pulls some declarations out of contexts where
-                // locations are not tracked. Perhaps they should be, but for now
-                // the full fill solves it.
-                forceFillCodeLocations( transUnit );
-
-                PASS( "Translate Exception Declarations", ControlStruct::translateExcept( transUnit ) );
-                if ( exdeclp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                }
-
-                PASS( "Verify Ctor, Dtor & Assign", Validate::verifyCtorDtorAssign( transUnit ) );
-                PASS( "Replace Typedefs", Validate::replaceTypedef( transUnit ) );
-                PASS( "Fix Return Types", Validate::fixReturnTypes( transUnit ) );
-                PASS( "Enum and Pointer Decay", Validate::decayEnumsAndPointers( transUnit ) );
-
-                PASS( "Link Reference To Types", Validate::linkReferenceToTypes( transUnit ) );
-
-                PASS( "Fix Qualified Types", Validate::fixQualifiedTypes( transUnit ) );
-                PASS( "Hoist Struct", Validate::hoistStruct( transUnit ) );
-                PASS( "Eliminate Typedef", Validate::eliminateTypedef( transUnit ) );
-                PASS( "Validate Generic Parameters", Validate::fillGenericParameters( transUnit ) );
-                PASS( "Translate Dimensions", Validate::translateDimensionParameters( transUnit ) );
-                PASS( "Check Function Returns", Validate::checkReturnStatements( transUnit ) );
-                PASS( "Fix Return Statements", InitTweak::fixReturnStatements( transUnit ) );
-                PASS( "Implement Concurrent Keywords", Concurrency::implementKeywords( transUnit ) );
-                PASS( "Forall Pointer Decay", Validate::decayForallPointers( transUnit ) );
-        PASS( "Implement Waituntil", Concurrency::generateWaitUntil( transUnit ) );
-                PASS( "Hoist Control Declarations", ControlStruct::hoistControlDecls( transUnit ) );
-
-                PASS( "Generate Autogen Routines", Validate::autogenerateRoutines( transUnit ) );
-
-                PASS( "Implement Actors", Concurrency::implementActors( transUnit ) );
-        PASS( "Implement Virtual Destructors", Virtual::implementVirtDtors(transUnit) );
-                PASS( "Implement Mutex", Concurrency::implementMutex( transUnit ) );
-                PASS( "Implement Thread Start", Concurrency::implementThreadStarter( transUnit ) );
-                PASS( "Compound Literal", Validate::handleCompoundLiterals( transUnit ) );
-                PASS( "Set Length From Initializer", Validate::setLengthFromInitializer( transUnit ) );
-                PASS( "Find Global Decls", Validate::findGlobalDecls( transUnit ) );
-                PASS( "Fix Label Address", Validate::fixLabelAddresses( transUnit ) );
+                PASS( "Hoist Type Decls", Validate::hoistTypeDecls, transUnit );
+
+                PASS( "Translate Exception Declarations", ControlStruct::translateExcept, transUnit );
+                DUMP( exdeclp, std::move( transUnit ) );
+                PASS( "Verify Ctor, Dtor & Assign", Validate::verifyCtorDtorAssign, transUnit );
+                PASS( "Replace Typedefs", Validate::replaceTypedef, transUnit );
+                PASS( "Fix Return Types", Validate::fixReturnTypes, transUnit );
+                PASS( "Enum and Pointer Decay", Validate::decayEnumsAndPointers, transUnit );
+
+                PASS( "Link Reference To Types", Validate::linkReferenceToTypes, transUnit );
+
+                PASS( "Fix Qualified Types", Validate::fixQualifiedTypes, transUnit );
+                PASS( "Hoist Struct", Validate::hoistStruct, transUnit );
+                PASS( "Eliminate Typedef", Validate::eliminateTypedef, transUnit );
+                PASS( "Validate Generic Parameters", Validate::fillGenericParameters, transUnit );
+                PASS( "Translate Dimensions", Validate::translateDimensionParameters, transUnit );
+                PASS( "Check Function Returns", Validate::checkReturnStatements, transUnit );
+                PASS( "Fix Return Statements", InitTweak::fixReturnStatements, transUnit );
+                PASS( "Implement Concurrent Keywords", Concurrency::implementKeywords, transUnit );
+                PASS( "Forall Pointer Decay", Validate::decayForallPointers, transUnit );
+        PASS( "Implement Waituntil", Concurrency::generateWaitUntil, transUnit  );
+                PASS( "Hoist Control Declarations", ControlStruct::hoistControlDecls, transUnit );
+
+                PASS( "Generate Autogen Routines", Validate::autogenerateRoutines, transUnit );
+
+                PASS( "Implement Actors", Concurrency::implementActors, transUnit );
+                PASS( "Implement Virtual Destructors", Virtual::implementVirtDtors, transUnit );
+                PASS( "Implement Mutex", Concurrency::implementMutex, transUnit );
+                PASS( "Implement Thread Start", Concurrency::implementThreadStarter, transUnit );
+                PASS( "Compound Literal", Validate::handleCompoundLiterals, transUnit );
+                PASS( "Set Length From Initializer", Validate::setLengthFromInitializer, transUnit );
+                PASS( "Find Global Decls", Validate::findGlobalDecls, transUnit );
+                PASS( "Fix Label Address", Validate::fixLabelAddresses, transUnit );
 
                 if ( symtabp ) {
@@ -361 +364 @@
                 } // if
 
-                if ( validp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
-
-                PASS( "Translate Throws", ControlStruct::translateThrows( transUnit ) );
-                PASS( "Fix Labels", ControlStruct::fixLabels( transUnit ) );
-                PASS( "Fix Names", CodeGen::fixNames( transUnit ) );
-                PASS( "Gen Init", InitTweak::genInit( transUnit ) );
-                PASS( "Expand Member Tuples" , Tuples::expandMemberTuples( transUnit ) );
+                DUMP( validp, std::move( transUnit ) );
+
+                PASS( "Translate Throws", ControlStruct::translateThrows, transUnit );
+                PASS( "Fix Labels", ControlStruct::fixLabels, transUnit );
+                PASS( "Fix Names", CodeGen::fixNames, transUnit );
+                PASS( "Gen Init", InitTweak::genInit, transUnit );
+                PASS( "Expand Member Tuples" , Tuples::expandMemberTuples, transUnit );
 
                 if ( libcfap ) {
@@ -382 +382 @@
                 } // if
 
-                if ( bresolvep ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
+                DUMP( bresolvep, std::move( transUnit ) );
 
                 if ( resolvprotop ) {
@@ -392 +389 @@
                 } // if
 
-                PASS( "Resolve", ResolvExpr::resolve( transUnit ) );
-                if ( exprp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
-
-                forceFillCodeLocations( transUnit );
-
-                PASS( "Fix Init", InitTweak::fix(transUnit, buildingLibrary()));
+                PASS( "Resolve", ResolvExpr::resolve, transUnit );
+                DUMP( exprp, std::move( transUnit ) );
+
+                PASS( "Fix Init", InitTweak::fix, transUnit, buildingLibrary() );
 
                 // fix ObjectDecl - replaces ConstructorInit nodes
-                if ( ctorinitp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
+                DUMP( ctorinitp, std::move( transUnit ) );
 
                 // Currently not working due to unresolved issues with UniqueExpr
-                PASS( "Expand Unique Expr", Tuples::expandUniqueExpr( transUnit ) ); // xxx - is this the right place for this? want to expand ASAP so tha, sequent passes don't need to worry about double-visiting a unique expr - needs to go after InitTweak::fix so that copy constructed return declarations are reused
-
-                PASS( "Translate Tries", ControlStruct::translateTries( transUnit ) );
-                PASS( "Gen Waitfor", Concurrency::generateWaitFor( transUnit ) );
+                PASS( "Expand Unique Expr", Tuples::expandUniqueExpr, transUnit ); // xxx - is this the right place for this? want to expand ASAP so tha, sequent passes don't need to worry about double-visiting a unique expr - needs to go after InitTweak::fix so that copy constructed return declarations are reused
+
+                PASS( "Translate Tries", ControlStruct::translateTries, transUnit );
+                PASS( "Gen Waitfor", Concurrency::generateWaitFor, transUnit );
 
                 // Needs to happen before tuple types are expanded.
-                PASS( "Convert Specializations",  GenPoly::convertSpecializations( transUnit ) );
-
-                PASS( "Expand Tuples", Tuples::expandTuples( transUnit ) );
-
-                if ( tuplep ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
+                PASS( "Convert Specializations",  GenPoly::convertSpecializations, transUnit );
+
+                PASS( "Expand Tuples", Tuples::expandTuples, transUnit );
+                DUMP( tuplep, std::move( transUnit ) );
 
                 // Must come after Translate Tries.
-                PASS( "Virtual Expand Casts", Virtual::expandCasts( transUnit ) );
-
-                PASS( "Instantiate Generics", GenPoly::instantiateGeneric( transUnit ) );
-                if ( genericsp ) {
-                        dump( std::move( transUnit ) );
-                        return EXIT_SUCCESS;
-                } // if
-
-                PASS( "Convert L-Value", GenPoly::convertLvalue( transUnit ) );
+                PASS( "Virtual Expand Casts", Virtual::expandCasts, transUnit );
+
+                PASS( "Instantiate Generics", GenPoly::instantiateGeneric, transUnit );
+                DUMP( genericsp, std::move( transUnit ) );
+
+                PASS( "Convert L-Value", GenPoly::convertLvalue, transUnit );
 
                 translationUnit = convert( std::move( transUnit ) );
 
-                if ( bboxp ) {
-                        dump( translationUnit );
-                        return EXIT_SUCCESS;
-                } // if
-                PASS( "Box", GenPoly::box( translationUnit ) );
-
-                PASS( "Link-Once", CodeGen::translateLinkOnce( translationUnit ) );
+                DUMP( bboxp, translationUnit );
+                PASS( "Box", GenPoly::box, translationUnit );
+
+                PASS( "Link-Once", CodeGen::translateLinkOnce, translationUnit );
 
                 // Code has been lowered to C, now we can start generation.
 
-                if ( bcodegenp ) {
-                        dump( translationUnit );
-                        return EXIT_SUCCESS;
-                } // if
+                DUMP( bcodegenp, translationUnit );
 
                 if ( optind < argc ) {                                                  // any commands after the flags and input file ? => output file name
@@ -457 +433 @@
 
                 CodeTools::fillLocations( translationUnit );
-                PASS( "Code Gen", CodeGen::generate( translationUnit, *output, ! genproto, prettycodegenp, true, linemarks ) );
+                PASS( "Code Gen", CodeGen::generate, translationUnit, *output, ! genproto, prettycodegenp, true, linemarks );
 
                 CodeGen::FixMain::fix( translationUnit, *output,
@@ -505 +481 @@
 
 
-static const char optstring[] = ":c:ghlLmNnpdP:S:twW:D:";
+static const char optstring[] = ":c:ghilLmNnpdP:S:twW:D:";
 
 enum { PreludeDir = 128 };
@@ -512 +488 @@
         { "gdb", no_argument, nullptr, 'g' },
         { "help", no_argument, nullptr, 'h' },
+        { "invariant", no_argument, nullptr, 'i' },
         { "libcfa", no_argument, nullptr, 'l' },
         { "linemarks", no_argument, nullptr, 'L' },
-        { "no-main", no_argument, 0, 'm' },
+        { "no-main", no_argument, nullptr, 'm' },
         { "no-linemarks", no_argument, nullptr, 'N' },
         { "no-prelude", no_argument, nullptr, 'n' },
@@ -533 +510 @@
         "wait for gdb to attach",                                                       // -g
         "print translator help message",                                        // -h
+        "invariant checking during AST passes",                         // -i
         "generate libcfa.c",                                                            // -l
         "generate line marks",                                                          // -L
@@ -626 +604 @@
                         usage( argv );                                                          // no return
                         break;
+                  case 'i':                                                                             // invariant checking
+                        invariant = true;
+                        break;
                   case 'l':                                                                             // generate libcfa.c
                         libcfap = true;