Changeset c1ed2ee

Timestamp:

Jun 21, 2019, 3:41:36 PM (5 years ago)

Author:

Aaron Moss <a3moss@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

8d61d620

Parents:

9af00d23

Message:

Continued resolver porting

• mostly initialization and validation
• added move() and copy() to utility.h

Location:

src

Files:

• AST/Stmt.hpp (modified) (1 diff)
• Common/utility.h (modified) (1 diff)
• InitTweak/InitTweak.cc (modified) (8 diffs)
• InitTweak/InitTweak.h (modified) (1 diff)
• ResolvExpr/AlternativeFinder.cc (modified) (1 diff)
• ResolvExpr/CandidateFinder.cpp (modified) (2 diffs)
• SymTab/FixFunction.cc (modified) (4 diffs)
• SymTab/FixFunction.h (modified) (1 diff)
• SymTab/Validate.cc (modified) (27 diffs)

src/AST/Stmt.hpp

@@ -143 +143 @@
 
         IfStmt( const CodeLocation & loc, const Expr * cond, const Stmt * thenPart,
-                Stmt * const elsePart, std::vector<ptr<Stmt>> && inits,
+                const Stmt * elsePart = nullptr, std::vector<ptr<Stmt>> && inits = {},
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), cond(cond), thenPart(thenPart), elsePart(elsePart),

src/Common/utility.h

@@ -34 +34 @@
 class Expression;
 
+/// bring std::move into global scope
+using std::move;
+
+/// partner to move that copies any copyable type
+template<typename T>
+T copy( const T & x ) { return x; }
+
 template< typename T >
 static inline T * maybeClone( const T *orig ) {

src/InitTweak/InitTweak.cc

@@ -22 +22 @@
 
 #include "AST/Expr.hpp"
+#include "AST/Init.hpp"
 #include "AST/Node.hpp"
+#include "AST/Pass.hpp"
 #include "AST/Stmt.hpp"
 #include "AST/Type.hpp"
@@ -85 +87 @@
                 };
 
-                struct InitFlattener : public WithShortCircuiting {
+                struct InitFlattener_old : public WithShortCircuiting {
                         void previsit( SingleInit * singleInit ) {
                                 visit_children = false;
@@ -93 +95 @@
                 };
 
-        }
+                struct InitFlattener_new : public ast::WithShortCircuiting {
+                        std::vector< ast::ptr< ast::Expr > > argList;
+
+                        void previsit( const ast::SingleInit * singleInit ) {
+                                visit_children = false;
+                                argList.emplace_back( singleInit->value );
+                        }
+                };
+
+        } // anonymous namespace
 
         std::list< Expression * > makeInitList( Initializer * init ) {
-                PassVisitor<InitFlattener> flattener;
+                PassVisitor<InitFlattener_old> flattener;
                 maybeAccept( init, flattener );
                 return flattener.pass.argList;
@@ -114 +125 @@
 
 std::vector< ast::ptr< ast::Expr > > makeInitList( const ast::Init * init ) {
-        #warning unimplmented
-        (void)init;
-        assert(false);
-        return {};
+        ast::Pass< InitFlattener_new > flattener;
+        maybe_accept( init, flattener );
+        return std::move( flattener.pass.argList );
 }
 
@@ -309 +319 @@
         virtual std::vector< ast::ptr< ast::Expr > > next( IndexList & indices ) = 0;
         virtual ast::ptr< ast::Stmt > buildListInit( 
-                const ast::UntypedExpr * callExpr, IndexList & indices ) = 0;
+                ast::UntypedExpr * callExpr, IndexList & indices ) = 0;
 };
 
 namespace {
+        template< typename Out >
+        void buildCallExpr( 
+                ast::UntypedExpr * callExpr, const ast::Expr * index, const ast::Expr * dimension, 
+                const ast::Init * init, Out & out
+        ) {
+                const CodeLocation & loc = init->location;
+
+                auto cond = new ast::UntypedExpr{ 
+                        loc, new ast::NameExpr{ loc, "?<?" }, { index, dimension } };
+                
+                std::vector< ast::ptr< ast::Expr > > args = makeInitList( init );
+                splice( callExpr->args, args );
+
+                out.emplace_back( new ast::IfStmt{ loc, cond, new ast::ExprStmt{ loc, callExpr } } );
+
+                out.emplace_back( new ast::ExprStmt{ 
+                        loc, new ast::UntypedExpr{ loc, new ast::NameExpr{ loc, "++?" }, { index } } } );
+        }
+
+        template< typename Out >
+        void build(
+                ast::UntypedExpr * callExpr, const InitExpander_new::IndexList & indices, 
+                const ast::Init * init, Out & out
+        ) {
+                if ( indices.empty() ) return;
+
+                unsigned idx = 0;
+
+                const ast::Expr * index = indices[idx++];
+                assert( idx != indices.size() );
+                const ast::Expr * dimension = indices[idx++];
+
+                if ( idx == indices.size() ) {
+                        if ( auto listInit = dynamic_cast< const ast::ListInit * >( init ) ) {
+                                for ( const ast::Init * init : *listInit ) {
+                                        buildCallExpr( callExpr, index, dimension, init, out );
+                                }
+                        } else {
+                                buildCallExpr( callExpr, index, dimension, init, out );
+                        }
+                } else {
+                        const CodeLocation & loc = init->location;
+
+                        unsigned long cond = 0;
+                        auto listInit = dynamic_cast< const ast::ListInit * >( init );
+                        if ( ! listInit ) { SemanticError( loc, "unbalanced list initializers" ); }
+
+                        static UniqueName targetLabel( "L__autogen__" );
+                        ast::Label switchLabel{ 
+                                loc, targetLabel.newName(), { new ast::Attribute{ "unused" } } };
+                        
+                        std::vector< ast::ptr< ast::Stmt > > branches;
+                        for ( const ast::Init * init : *listInit ) {
+                                auto condition = ast::ConstantExpr::from_ulong( loc, cond );
+                                ++cond;
+
+                                std::vector< ast::ptr< ast::Stmt > > stmts;
+                                build( callExpr, indices, init, stmts );
+                                stmts.emplace_back( 
+                                        new ast::BranchStmt{ loc, ast::BranchStmt::Break, switchLabel } );
+                                branches.emplace_back( new ast::CaseStmt{ loc, condition, std::move( stmts ) } );
+                        }
+                        out.emplace_back( new ast::SwitchStmt{ loc, index, std::move( branches ) } );
+                        out.emplace_back( new ast::NullStmt{ loc, { switchLabel } } );
+                }
+        }
+
         class InitImpl_new final : public InitExpander_new::ExpanderImpl {
                 ast::ptr< ast::Init > init;
@@ -323 +400 @@
                 
                 ast::ptr< ast::Stmt > buildListInit( 
-                        const ast::UntypedExpr * callExpr, InitExpander_new::IndexList & indices 
+                        ast::UntypedExpr * callExpr, InitExpander_new::IndexList & indices 
                 ) override {
-                        #warning unimplemented
-                        (void)callExpr; (void)indices;
-                        assert(false);
-                        return {};
+                        // If array came with an initializer list, initialize each element. We may have more 
+                        // initializers than elements of the array; need to check at each index that we have 
+                        // not exceeded size. We may have fewer initializers than elements in the array; need 
+                        // to default-construct remaining elements. To accomplish this, generate switch 
+                        // statement consuming all of expander's elements
+
+                        if ( ! init ) return {};
+
+                        std::list< ast::ptr< ast::Stmt > > stmts;
+                        build( callExpr, indices, init, stmts );
+                        if ( stmts.empty() ) {
+                                return {};
+                        } else {
+                                auto block = new ast::CompoundStmt{ init->location, std::move( stmts ) };
+                                init = nullptr;  // consumed in creating the list init
+                                return block;
+                        }
                 }
         };
@@ -340 +430 @@
                         InitExpander_new::IndexList & indices 
                 ) override {
-                        #warning unimplemented
-                        (void)indices;
-                        assert(false);
-                        return {};
+                        if ( ! arg ) return {};
+
+                        const CodeLocation & loc = arg->location;
+                        const ast::Expr * expr = arg;
+                        for ( auto it = indices.rbegin(); it != indices.rend(); ++it ) {
+                                // go through indices and layer on subscript exprs ?[?]
+                                ++it;
+                                expr = new ast::UntypedExpr{ 
+                                        loc, new ast::NameExpr{ loc, "?[?]" }, { expr, *it } };
+                        }
+                        return { expr };
                 }
                 
                 ast::ptr< ast::Stmt > buildListInit( 
-                        const ast::UntypedExpr *, InitExpander_new::IndexList & 
+                        ast::UntypedExpr *, InitExpander_new::IndexList & 
                 ) override { 
                         return {};
@@ -369 +466 @@
 /// builds statement which has the same semantics as a C-style list initializer (for array 
 /// initializers) using callExpr as the base expression to perform initialization
-ast::ptr< ast::Stmt > InitExpander_new::buildListInit( const ast::UntypedExpr * callExpr ) {
+ast::ptr< ast::Stmt > InitExpander_new::buildListInit( ast::UntypedExpr * callExpr ) {
         return expander->buildListInit( callExpr, indices );
 }

src/InitTweak/InitTweak.h

@@ -154 +154 @@
 
                 /// builds statement which has the same semantics as a C-style list initializer (for array 
-                /// initializers) using callExpr as the base expression to perform initialization
-                ast::ptr< ast::Stmt > buildListInit( const ast::UntypedExpr * callExpr );
+                /// initializers) using callExpr as the base expression to perform initialization. 
+                /// Mutates callExpr
+                ast::ptr< ast::Stmt > buildListInit( ast::UntypedExpr * callExpr );
 
                 void addArrayIndex( const ast::Expr * index, const ast::Expr * dimension );

src/ResolvExpr/AlternativeFinder.cc

@@ -56 +56 @@
 #define PRINT( text ) if ( resolvep ) { text }
 //#define DEBUG_COST
-
-using std::move;
-
-/// copies any copyable type
-template<typename T>
-T copy(const T& x) { return x; }
 
 namespace ResolvExpr {

src/ResolvExpr/CandidateFinder.cpp

@@ -39 +39 @@
 #include "AST/SymbolTable.hpp"
 #include "AST/Type.hpp"
+#include "Common/utility.h"       // for move, copy
 #include "SymTab/Mangler.h"
 #include "SymTab/Validate.h"      // for validateType
@@ -46 +47 @@
 
 namespace ResolvExpr {
-
-using std::move;
-
-/// partner to move that copies any copyable type
-template<typename T>
-T copy( const T & x ) { return x; }
 
 const ast::Expr * referenceToRvalueConversion( const ast::Expr * expr, Cost & cost ) {

src/SymTab/FixFunction.cc

@@ -18 +18 @@
 #include <list>                   // for list
 
-#include "Common/utility.h"       // for maybeClone
+#include "AST/Decl.hpp"
+#include "AST/Pass.hpp"
+#include "AST/Type.hpp"
+#include "Common/utility.h"       // for maybeClone, copy
 #include "SynTree/Declaration.h"  // for FunctionDecl, ObjectDecl, Declarati...
 #include "SynTree/Expression.h"   // for Expression
@@ -24 +27 @@
 
 namespace SymTab {
-        FixFunction::FixFunction() : isVoid( false ) {}
+        class FixFunction_old : public WithShortCircuiting {
+                typedef Mutator Parent;
+          public:
+                FixFunction_old() : isVoid( false ) {}
 
+                void premutate(FunctionDecl *functionDecl);
+                DeclarationWithType* postmutate(FunctionDecl *functionDecl);
 
-        DeclarationWithType * FixFunction::postmutate(FunctionDecl *functionDecl) {
+                Type * postmutate(ArrayType * arrayType);
+
+                void premutate(ArrayType * arrayType);
+                void premutate(VoidType * voidType);
+                void premutate(BasicType * basicType);
+                void premutate(PointerType * pointerType);
+                void premutate(StructInstType * aggregateUseType);
+                void premutate(UnionInstType * aggregateUseType);
+                void premutate(EnumInstType * aggregateUseType);
+                void premutate(TraitInstType * aggregateUseType);
+                void premutate(TypeInstType * aggregateUseType);
+                void premutate(TupleType * tupleType);
+                void premutate(VarArgsType * varArgsType);
+                void premutate(ZeroType * zeroType);
+                void premutate(OneType * oneType);
+
+                bool isVoid;
+        };
+
+        DeclarationWithType * FixFunction_old::postmutate(FunctionDecl *functionDecl) {
                 // can't delete function type because it may contain assertions, so transfer ownership to new object
                 ObjectDecl *pointer = new ObjectDecl( functionDecl->name, functionDecl->get_storageClasses(), functionDecl->linkage, nullptr, new PointerType( Type::Qualifiers(), functionDecl->type ), nullptr, functionDecl->attributes );
@@ -41 +68 @@
         // does not cause an error
 
-        Type * FixFunction::postmutate(ArrayType *arrayType) {
+        Type * FixFunction_old::postmutate(ArrayType *arrayType) {
                 // need to recursively mutate the base type in order for multi-dimensional arrays to work.
                 PointerType *pointerType = new PointerType( arrayType->get_qualifiers(), arrayType->base, arrayType->dimension, arrayType->isVarLen, arrayType->isStatic );
@@ -51 +78 @@
         }
 
-        void FixFunction::premutate(VoidType *) {
+        void FixFunction_old::premutate(VoidType *) {
                 isVoid = true;
         }
 
-        void FixFunction::premutate(FunctionDecl *) { visit_children = false; }
-        void FixFunction::premutate(ArrayType *) { visit_children = false; }
-        void FixFunction::premutate(BasicType *) { visit_children = false; }
-        void FixFunction::premutate(PointerType *) { visit_children = false; }
-        void FixFunction::premutate(StructInstType *) { visit_children = false; }
-        void FixFunction::premutate(UnionInstType *) { visit_children = false; }
-        void FixFunction::premutate(EnumInstType *) { visit_children = false; }
-        void FixFunction::premutate(TraitInstType *) { visit_children = false; }
-        void FixFunction::premutate(TypeInstType *) { visit_children = false; }
-        void FixFunction::premutate(TupleType *) { visit_children = false; }
-        void FixFunction::premutate(VarArgsType *) { visit_children = false; }
-        void FixFunction::premutate(ZeroType *) { visit_children = false; }
-        void FixFunction::premutate(OneType *) { visit_children = false; }
+        void FixFunction_old::premutate(FunctionDecl *) { visit_children = false; }
+        void FixFunction_old::premutate(ArrayType *) { visit_children = false; }
+        void FixFunction_old::premutate(BasicType *) { visit_children = false; }
+        void FixFunction_old::premutate(PointerType *) { visit_children = false; }
+        void FixFunction_old::premutate(StructInstType *) { visit_children = false; }
+        void FixFunction_old::premutate(UnionInstType *) { visit_children = false; }
+        void FixFunction_old::premutate(EnumInstType *) { visit_children = false; }
+        void FixFunction_old::premutate(TraitInstType *) { visit_children = false; }
+        void FixFunction_old::premutate(TypeInstType *) { visit_children = false; }
+        void FixFunction_old::premutate(TupleType *) { visit_children = false; }
+        void FixFunction_old::premutate(VarArgsType *) { visit_children = false; }
+        void FixFunction_old::premutate(ZeroType *) { visit_children = false; }
+        void FixFunction_old::premutate(OneType *) { visit_children = false; }
 
         bool fixFunction( DeclarationWithType *& dwt ) {
-                PassVisitor<FixFunction> fixer;
+                PassVisitor<FixFunction_old> fixer;
                 dwt = dwt->acceptMutator( fixer );
                 return fixer.pass.isVoid;
         }
+
+namespace {
+        struct FixFunction_new final : public ast::WithShortCircuiting {
+                bool isVoid = false;
+
+                void premutate( const ast::FunctionDecl * ) { visit_children = false; }
+
+                const ast::DeclWithType * postmutate( const ast::FunctionDecl * func ) {
+                        return new ast::ObjectDecl{ 
+                                func->location, func->name, new ast::PointerType{ func->type }, nullptr, 
+                                func->storage, func->linkage, nullptr, copy( func->attributes ) };
+                }
+
+                void premutate( const ast::ArrayType * ) { visit_children = false; }
+
+                const ast::Type * postmutate( const ast::ArrayType * array ) {
+                        return new ast::PointerType{ 
+                                array->base, array->dimension, array->isVarLen, array->isStatic, 
+                                array->qualifiers };
+                }
+
+                void premutate( const ast::VoidType * ) { isVoid = true; }
+
+                void premutate( const ast::BasicType * ) { visit_children = false; }
+                void premutate( const ast::PointerType * ) { visit_children = false; }
+                void premutate( const ast::StructInstType * ) { visit_children = false; }
+                void premutate( const ast::UnionInstType * ) { visit_children = false; }
+                void premutate( const ast::EnumInstType * ) { visit_children = false; }
+                void premutate( const ast::TraitInstType * ) { visit_children = false; }
+                void premutate( const ast::TypeInstType * ) { visit_children = false; }
+                void premutate( const ast::TupleType * ) { visit_children = false; }
+                void premutate( const ast::VarArgsType * ) { visit_children = false; }
+                void premutate( const ast::ZeroType * ) { visit_children = false; }
+                void premutate( const ast::OneType * ) { visit_children = false; }
+        };
+} // anonymous namespace
+
+const ast::DeclWithType * fixFunction( const ast::DeclWithType * dwt, bool & isVoid ) {
+        ast::Pass< FixFunction_new > fixer;
+        dwt = dwt->accept( fixer );
+        isVoid |= fixer.pass.isVoid;
+        return dwt;
+}
+
 } // namespace SymTab
 

src/SymTab/FixFunction.h

@@ -19 +19 @@
 #include "SynTree/SynTree.h"    // for Types
 
+namespace ast {
+        class DeclWithType;
+}
+
 namespace SymTab {
-        /// Replaces function and array types by equivalent pointer types.
-        class FixFunction : public WithShortCircuiting {
-                typedef Mutator Parent;
-          public:
-                FixFunction();
+        /// Replaces function and array types by equivalent pointer types. Returns true if type is 
+        /// void
+        bool fixFunction( DeclarationWithType *& );
 
-                void premutate(FunctionDecl *functionDecl);
-                DeclarationWithType* postmutate(FunctionDecl *functionDecl);
-
-                Type * postmutate(ArrayType * arrayType);
-
-                void premutate(ArrayType * arrayType);
-                void premutate(VoidType * voidType);
-                void premutate(BasicType * basicType);
-                void premutate(PointerType * pointerType);
-                void premutate(StructInstType * aggregateUseType);
-                void premutate(UnionInstType * aggregateUseType);
-                void premutate(EnumInstType * aggregateUseType);
-                void premutate(TraitInstType * aggregateUseType);
-                void premutate(TypeInstType * aggregateUseType);
-                void premutate(TupleType * tupleType);
-                void premutate(VarArgsType * varArgsType);
-                void premutate(ZeroType * zeroType);
-                void premutate(OneType * oneType);
-
-                bool isVoid;
-        };
-
-        bool fixFunction( DeclarationWithType *& );
+        /// Returns declaration with function and array types replaced by equivalent pointer types.
+        /// Sets isVoid to true if type is void
+        const ast::DeclWithType * fixFunction( const ast::DeclWithType * dwt, bool & isVoid );
 } // namespace SymTab
 

src/SymTab/Validate.cc

@@ -46 +46 @@
 #include <utility>                     // for pair
 
+#include "AST/Decl.hpp"
+#include "AST/Node.hpp"
+#include "AST/Pass.hpp"
+#include "AST/SymbolTable.hpp"
+#include "AST/Type.hpp"
 #include "CodeGen/CodeGenerator.h"     // for genName
 #include "CodeGen/OperatorTable.h"     // for isCtorDtor, isCtorDtorAssign
@@ -124 +129 @@
 
         /// Replaces enum types by int, and function or array types in function parameter and return lists by appropriate pointers.
-        struct EnumAndPointerDecay {
+        struct EnumAndPointerDecay_old {
                 void previsit( EnumDecl *aggregateDecl );
                 void previsit( FunctionType *func );
@@ -130 +135 @@
 
         /// Associates forward declarations of aggregates with their definitions
-        struct LinkReferenceToTypes final : public WithIndexer, public WithGuards, public WithVisitorRef<LinkReferenceToTypes>, public WithShortCircuiting {
-                LinkReferenceToTypes( const Indexer *indexer );
+        struct LinkReferenceToTypes_old final : public WithIndexer, public WithGuards, public WithVisitorRef<LinkReferenceToTypes_old>, public WithShortCircuiting {
+                LinkReferenceToTypes_old( const Indexer *indexer );
                 void postvisit( TypeInstType *typeInst );
 
@@ -165 +170 @@
 
         /// Replaces array and function types in forall lists by appropriate pointer type and assigns each Object and Function declaration a unique ID.
-        struct ForallPointerDecay final {
+        struct ForallPointerDecay_old final {
                 void previsit( ObjectDecl * object );
                 void previsit( FunctionDecl * func );
@@ -290 +295 @@
 
         void validate( std::list< Declaration * > &translationUnit, __attribute__((unused)) bool doDebug ) {
-                PassVisitor<EnumAndPointerDecay> epc;
-                PassVisitor<LinkReferenceToTypes> lrt( nullptr );
-                PassVisitor<ForallPointerDecay> fpd;
+                PassVisitor<EnumAndPointerDecay_old> epc;
+                PassVisitor<LinkReferenceToTypes_old> lrt( nullptr );
+                PassVisitor<ForallPointerDecay_old> fpd;
                 PassVisitor<CompoundLiteral> compoundliteral;
                 PassVisitor<ValidateGenericParameters> genericParams;
@@ -305 +310 @@
                         ReplaceTypedef::replaceTypedef( translationUnit );
                         ReturnTypeFixer::fix( translationUnit ); // must happen before autogen
-                        acceptAll( translationUnit, epc ); // must happen before VerifyCtorDtorAssign, because void return objects should not exist; before LinkReferenceToTypes because it is an indexer and needs correct types for mangling
+                        acceptAll( translationUnit, epc ); // must happen before VerifyCtorDtorAssign, because void return objects should not exist; before LinkReferenceToTypes_old because it is an indexer and needs correct types for mangling
                 }
                 {
@@ -314 +319 @@
                         });
                         Stats::Time::TimeBlock("Fix Qualified Types", [&]() {
-                                mutateAll( translationUnit, fixQual ); // must happen after LinkReferenceToTypes, because aggregate members are accessed
+                                mutateAll( translationUnit, fixQual ); // must happen after LinkReferenceToTypes_old, because aggregate members are accessed
                         });
                         Stats::Time::TimeBlock("Hoist Structs", [&]() {
@@ -326 +331 @@
                         Stats::Heap::newPass("validate-C");
                         Stats::Time::BlockGuard guard("validate-C");
-                        acceptAll( translationUnit, genericParams );  // check as early as possible - can't happen before LinkReferenceToTypes
+                        acceptAll( translationUnit, genericParams );  // check as early as possible - can't happen before LinkReferenceToTypes_old
                         VerifyCtorDtorAssign::verify( translationUnit );  // must happen before autogen, because autogen examines existing ctor/dtors
                         ReturnChecker::checkFunctionReturns( translationUnit );
@@ -344 +349 @@
                         });
                         Stats::Time::TimeBlock("Generate Autogen routines", [&]() {
-                                autogenerateRoutines( translationUnit ); // moved up, used to be below compoundLiteral - currently needs EnumAndPointerDecay
+                                autogenerateRoutines( translationUnit ); // moved up, used to be below compoundLiteral - currently needs EnumAndPointerDecay_old
                         });
                 }
@@ -385 +390 @@
 
         void validateType( Type *type, const Indexer *indexer ) {
-                PassVisitor<EnumAndPointerDecay> epc;
-                PassVisitor<LinkReferenceToTypes> lrt( indexer );
-                PassVisitor<ForallPointerDecay> fpd;
+                PassVisitor<EnumAndPointerDecay_old> epc;
+                PassVisitor<LinkReferenceToTypes_old> lrt( indexer );
+                PassVisitor<ForallPointerDecay_old> fpd;
                 type->accept( epc );
                 type->accept( lrt );
@@ -586 +591 @@
         }
 
-        void EnumAndPointerDecay::previsit( EnumDecl *enumDecl ) {
+        void EnumAndPointerDecay_old::previsit( EnumDecl *enumDecl ) {
                 // Set the type of each member of the enumeration to be EnumConstant
                 for ( std::list< Declaration * >::iterator i = enumDecl->members.begin(); i != enumDecl->members.end(); ++i ) {
@@ -618 +623 @@
         }
 
-        void EnumAndPointerDecay::previsit( FunctionType *func ) {
+        void EnumAndPointerDecay_old::previsit( FunctionType *func ) {
                 // Fix up parameters and return types
                 fixFunctionList( func->parameters, func->isVarArgs, func );
@@ -624 +629 @@
         }
 
-        LinkReferenceToTypes::LinkReferenceToTypes( const Indexer *other_indexer ) {
+        LinkReferenceToTypes_old::LinkReferenceToTypes_old( const Indexer *other_indexer ) {
                 if ( other_indexer ) {
                         local_indexer = other_indexer;
@@ -632 +637 @@
         }
 
-        void LinkReferenceToTypes::postvisit( EnumInstType *enumInst ) {
+        void LinkReferenceToTypes_old::postvisit( EnumInstType *enumInst ) {
                 EnumDecl *st = local_indexer->lookupEnum( enumInst->name );
                 // it's not a semantic error if the enum is not found, just an implicit forward declaration
@@ -652 +657 @@
         }
 
-        void LinkReferenceToTypes::postvisit( StructInstType *structInst ) {
+        void LinkReferenceToTypes_old::postvisit( StructInstType *structInst ) {
                 StructDecl *st = local_indexer->lookupStruct( structInst->name );
                 // it's not a semantic error if the struct is not found, just an implicit forward declaration
@@ -665 +670 @@
         }
 
-        void LinkReferenceToTypes::postvisit( UnionInstType *unionInst ) {
+        void LinkReferenceToTypes_old::postvisit( UnionInstType *unionInst ) {
                 UnionDecl *un = local_indexer->lookupUnion( unionInst->name );
                 // it's not a semantic error if the union is not found, just an implicit forward declaration
@@ -678 +683 @@
         }
 
-        void LinkReferenceToTypes::previsit( QualifiedType * ) {
+        void LinkReferenceToTypes_old::previsit( QualifiedType * ) {
                 visit_children = false;
         }
 
-        void LinkReferenceToTypes::postvisit( QualifiedType * qualType ) {
+        void LinkReferenceToTypes_old::postvisit( QualifiedType * qualType ) {
                 // linking only makes sense for the 'oldest ancestor' of the qualified type
                 qualType->parent->accept( *visitor );
@@ -729 +734 @@
         }
 
-        void LinkReferenceToTypes::postvisit( TraitDecl * traitDecl ) {
+        void LinkReferenceToTypes_old::postvisit( TraitDecl * traitDecl ) {
                 if ( traitDecl->name == "sized" ) {
                         // "sized" is a special trait - flick the sized status on for the type variable
@@ -751 +756 @@
         }
 
-        void LinkReferenceToTypes::postvisit( TraitInstType * traitInst ) {
+        void LinkReferenceToTypes_old::postvisit( TraitInstType * traitInst ) {
                 // handle other traits
                 TraitDecl *traitDecl = local_indexer->lookupTrait( traitInst->name );
@@ -777 +782 @@
         }
 
-        void LinkReferenceToTypes::postvisit( EnumDecl *enumDecl ) {
+        void LinkReferenceToTypes_old::postvisit( EnumDecl *enumDecl ) {
                 // visit enum members first so that the types of self-referencing members are updated properly
                 if ( enumDecl->body ) {
@@ -799 +804 @@
         }
 
-        void LinkReferenceToTypes::renameGenericParams( std::list< TypeDecl * > & params ) {
+        void LinkReferenceToTypes_old::renameGenericParams( std::list< TypeDecl * > & params ) {
                 // rename generic type parameters uniquely so that they do not conflict with user-defined function forall parameters, e.g.
                 //   forall(otype T)
@@ -817 +822 @@
         }
 
-        void LinkReferenceToTypes::previsit( StructDecl * structDecl ) {
+        void LinkReferenceToTypes_old::previsit( StructDecl * structDecl ) {
                 renameGenericParams( structDecl->parameters );
         }
 
-        void LinkReferenceToTypes::previsit( UnionDecl * unionDecl ) {
+        void LinkReferenceToTypes_old::previsit( UnionDecl * unionDecl ) {
                 renameGenericParams( unionDecl->parameters );
         }
 
-        void LinkReferenceToTypes::postvisit( StructDecl *structDecl ) {
+        void LinkReferenceToTypes_old::postvisit( StructDecl *structDecl ) {
                 // visit struct members first so that the types of self-referencing members are updated properly
                 // xxx - need to ensure that type parameters match up between forward declarations and definition (most importantly, number of type parameters and their defaults)
@@ -839 +844 @@
         }
 
-        void LinkReferenceToTypes::postvisit( UnionDecl *unionDecl ) {
+        void LinkReferenceToTypes_old::postvisit( UnionDecl *unionDecl ) {
                 if ( unionDecl->body ) {
                         ForwardUnionsType::iterator fwds = forwardUnions.find( unionDecl->name );
@@ -851 +856 @@
         }
 
-        void LinkReferenceToTypes::postvisit( TypeInstType *typeInst ) {
+        void LinkReferenceToTypes_old::postvisit( TypeInstType *typeInst ) {
                 // ensure generic parameter instances are renamed like the base type
                 if ( inGeneric && typeInst->baseType ) typeInst->name = typeInst->baseType->name;
@@ -888 +893 @@
         }
 
-        void ForallPointerDecay::previsit( ObjectDecl *object ) {
+        void ForallPointerDecay_old::previsit( ObjectDecl *object ) {
                 // ensure that operator names only apply to functions or function pointers
                 if ( CodeGen::isOperator( object->name ) && ! dynamic_cast< FunctionType * >( object->type->stripDeclarator() ) ) {
@@ -896 +901 @@
         }
 
-        void ForallPointerDecay::previsit( FunctionDecl *func ) {
+        void ForallPointerDecay_old::previsit( FunctionDecl *func ) {
                 func->fixUniqueId();
         }
 
-        void ForallPointerDecay::previsit( FunctionType * ftype ) {
+        void ForallPointerDecay_old::previsit( FunctionType * ftype ) {
                 forallFixer( ftype->forall, ftype );
         }
 
-        void ForallPointerDecay::previsit( StructDecl * aggrDecl ) {
+        void ForallPointerDecay_old::previsit( StructDecl * aggrDecl ) {
                 forallFixer( aggrDecl->parameters, aggrDecl );
         }
 
-        void ForallPointerDecay::previsit( UnionDecl * aggrDecl ) {
+        void ForallPointerDecay_old::previsit( UnionDecl * aggrDecl ) {
                 forallFixer( aggrDecl->parameters, aggrDecl );
         }
@@ -1368 +1373 @@
         }
 
-        const ast::Type * validateType( const ast::Type * type, const ast::SymbolTable & symtab ) {
-                #warning unimplemented
-                (void)type; (void)symtab;
-                assert(false);
-                return nullptr;
-        }
+namespace {
+        /// Replaces enum types by int, and function/array types in function parameter and return 
+        /// lists by appropriate pointers
+        struct EnumAndPointerDecay_new {
+                const ast::EnumDecl * previsit( const ast::EnumDecl * enumDecl ) {
+                        // set the type of each member of the enumeration to be EnumConstant
+                        for ( unsigned i = 0; i < enumDecl->members.size(); ++i ) {
+                                // build new version of object with EnumConstant
+                                ast::ptr< ast::ObjectDecl > obj = 
+                                        enumDecl->members[i].strict_as< ast::ObjectDecl >();
+                                obj.get_and_mutate()->type = 
+                                        new ast::EnumInstType{ enumDecl->name, ast::CV::Const };
+                                
+                                // set into decl
+                                ast::EnumDecl * mut = mutate( enumDecl );
+                                mut->members[i] = obj.get();
+                                enumDecl = mut;
+                        }
+                        return enumDecl;
+                }
+
+                static const ast::FunctionType * fixFunctionList(
+                        const ast::FunctionType * func, 
+                        std::vector< ast::ptr< ast::DeclWithType > > ast::FunctionType::* field,
+                        ast::ArgumentFlag isVarArgs = ast::FixedArgs
+                ) {
+                        const auto & dwts = func->*field;
+                        unsigned nvals = dwts.size();
+                        bool hasVoid = false;
+                        for ( unsigned i = 0; i < nvals; ++i ) {
+                                func = ast::mutate_field_index( func, field, i, fixFunction( dwts[i], hasVoid ) );
+                        }
+                        
+                        // the only case in which "void" is valid is where it is the only one in the list
+                        if ( hasVoid && ( nvals > 1 || isVarArgs ) ) {
+                                SemanticError( 
+                                        dwts.front()->location, func, "invalid type void in function type" );
+                        }
+
+                        // one void is the only thing in the list, remove it
+                        if ( hasVoid ) {
+                                func = ast::mutate_field( 
+                                        func, field, std::vector< ast::ptr< ast::DeclWithType > >{} );
+                        }
+
+                        return func;
+                }
+
+                const ast::FunctionType * previsit( const ast::FunctionType * func ) {
+                        func = fixFunctionList( func, &ast::FunctionType::params, func->isVarArgs );
+                        return fixFunctionList( func, &ast::FunctionType::returns );
+                }
+        };
+
+        /// Associates forward declarations of aggregates with their definitions
+        struct LinkReferenceToTypes_new final 
+        : public ast::WithSymbolTable, public ast::WithGuards, public 
+          ast::WithVisitorRef<LinkReferenceToTypes_new>, public ast::WithShortCircuiting {
+                
+                const ast::SymbolTable * localSyms;
+
+                LinkReferenceToTypes_new( const ast::SymbolTable & syms ) : localSyms( &syms ) {}
+
+                #warning incomplete
+        };
+
+        /// Replaces array and function types in forall lists by appropriate pointer type and assigns 
+        /// each object and function declaration a unique ID
+        struct ForallPointerDecay_new {
+                #warning incomplete
+        };
+} // anonymous namespace
+
+const ast::Type * validateType( const ast::Type * type, const ast::SymbolTable & symtab ) {
+        ast::Pass< EnumAndPointerDecay_new > epc;
+        ast::Pass< LinkReferenceToTypes_new > lrt{ symtab };
+        ast::Pass< ForallPointerDecay_new > fpd;
+
+        return type->accept( epc )->accept( lrt )->accept( fpd );
+}
+
 } // namespace SymTab