Changeset 54dd994 for src/SymTab

Timestamp:

Jun 24, 2019, 10:30:47 AM (7 years ago)

Author:

Thierry Delisle <tdelisle@…>

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, stuck-waitfor-destruct

Children:

84917e2

Parents:

3c6e417 (diff), 9e0a360 (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:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

Location:

src/SymTab

Files:

• Autogen.cc (modified) (3 diffs)
• Autogen.h (modified) (8 diffs)
• FixFunction.cc (modified) (4 diffs)
• FixFunction.h (modified) (1 diff)
• Validate.cc (modified) (27 diffs)

src/SymTab/Autogen.cc

@@ -24 +24 @@
 #include <vector>                  // for vector
 
+#include "AST/Decl.hpp"
 #include "CodeGen/OperatorTable.h" // for isCtorDtor, isCtorDtorAssign
 #include "Common/PassVisitor.h"    // for PassVisitor
@@ -209 +210 @@
         }
 
+        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 ) {
@@ -388 +393 @@
 
         void StructFuncGenerator::makeMemberOp( ObjectDecl * dstParam, Expression * src, DeclarationWithType * field, FunctionDecl * func, bool forward ) {
-                InitTweak::InitExpander srcParam( src );
+                InitTweak::InitExpander_old srcParam( src );
 
                 // assign to destination

src/SymTab/Autogen.h

@@ -17 +17 @@
 
 #include <cassert>                // for assert
+#include <iterator>               // for back_inserter
 #include <string>                 // for string
 
+#include "AST/Decl.hpp"
+#include "AST/Expr.hpp"
+#include "AST/Init.hpp"
+#include "AST/Node.hpp"
+#include "AST/Stmt.hpp"
+#include "AST/Type.hpp"
 #include "CodeGen/OperatorTable.h"
 #include "Common/UniqueName.h"    // for UniqueName
+#include "Common/utility.h"       // for splice
 #include "InitTweak/InitTweak.h"  // for InitExpander
 #include "SynTree/Constant.h"     // for Constant
@@ -36 +44 @@
         /// 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.
@@ -49 +58 @@
         FunctionType * genCopyType( Type * paramType, bool maybePolymorphic = true );
 
+        /// Enum for loop direction
+        enum LoopDirection { LoopBackward, LoopForward };
+
         /// inserts into out a generated call expression to function fname with arguments dstParam and srcParam. Intended to be used with generated ?=?, ?{}, and ^?{} calls.
         template< typename OutputIterator >
-        Statement * genCall( InitTweak::InitExpander & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, Type * type, Type * addCast = nullptr, bool forward = true );
+        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.
         /// optionally returns a statement which must be inserted prior to the containing loop, if there is one
         template< typename OutputIterator >
-        Statement * genScalarCall( InitTweak::InitExpander & srcParam, Expression * dstParam, std::string fname, OutputIterator out, Type * type, Type * addCast = nullptr ) {
+        Statement * genScalarCall( InitTweak::InitExpander_old & srcParam, Expression * dstParam, std::string fname, OutputIterator out, Type * type, Type * addCast = nullptr ) {
                 bool isReferenceCtorDtor = false;
                 if ( dynamic_cast< ReferenceType * >( type ) && CodeGen::isCtorDtor( fname ) ) {
@@ -106 +124 @@
         }
 
+        /// 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 );
+
+                const 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();
+                
+                return listInit;
+        }
+
         /// 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 OutputIterator >
-        void genArrayCall( InitTweak::InitExpander & srcParam, Expression *dstParam, const std::string & fname, OutputIterator out, ArrayType *array, Type * addCast = nullptr, bool forward = true ) {
+        void genArrayCall( InitTweak::InitExpander_old & srcParam, Expression *dstParam, const std::string & fname, OutputIterator out, ArrayType *array, Type * addCast = nullptr, bool forward = true ) {
                 static UniqueName indexName( "_index" );
 
@@ -170 +245 @@
         }
 
+        /// 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, cmp, update;
+
+                if ( forward ) {
+                        // generate: for ( int i = 0; i < N; ++i )
+                        begin = ast::ConstantExpr::from_int( loc, 0 );
+                        end = array->dimension;
+                        cmp = new ast::NameExpr{ loc, "?<?" };
+                        update = new ast::NameExpr{ loc, "++?" };
+                } else {
+                        // generate: for ( int i = N-1; i >= 0; --i )
+                        begin = new ast::UntypedExpr{ 
+                                loc, new ast::NameExpr{ loc, "?-?" }, 
+                                { array->dimension, ast::ConstantExpr::from_int( loc, 1 ) } };
+                        end = ast::ConstantExpr::from_int( loc, 0 );
+                        cmp = new ast::NameExpr{ loc, "?>=?" };
+                        update = new ast::NameExpr{ loc, "--?" };
+                }
+
+                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 > cond = new ast::UntypedExpr{
+                        loc, cmp, { new ast::VariableExpr{ loc, index }, end } };
+                
+                ast::ptr< ast::Expr > inc = new ast::UntypedExpr{
+                        loc, update, { new ast::VariableExpr{ loc, index } } };
+                
+                ast::ptr< ast::Expr > dstIndex = new ast::UntypedExpr{
+                        loc, new ast::NameExpr{ loc, "?[?]" }, 
+                        { dstParam, new ast::VariableExpr{ loc, index } } };
+                
+                // srcParam must keep track of the array indices to build the source parameter and/or 
+                // array list initializer
+                srcParam.addArrayIndex( new ast::VariableExpr{ loc, index }, 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 & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, Type * type, Type * addCast, bool forward ) {
+        Statement * genCall( InitTweak::InitExpander_old & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, Type * type, Type * addCast, bool forward ) {
                 if ( ArrayType * at = dynamic_cast< ArrayType * >( type ) ) {
                         genArrayCall( srcParam, dstParam, fname, out, at, addCast, forward );
@@ -180 +325 @@
         }
 
+        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 );
+                }
+        }
+
         /// inserts into out a generated call expression to function fname with arguments dstParam
         /// and srcParam. Intended to be used with generated ?=?, ?{}, and ^?{} calls. decl is the
@@ -185 +347 @@
         /// ImplicitCtorDtorStmt node.
         template< typename OutputIterator >
-        void genImplicitCall( InitTweak::InitExpander & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, DeclarationWithType * decl, bool forward = true ) {
+        void genImplicitCall( InitTweak::InitExpander_old & srcParam, Expression * dstParam, const std::string & fname, OutputIterator out, DeclarationWithType * decl, bool forward = true ) {
                 ObjectDecl *obj = dynamic_cast<ObjectDecl *>( decl );
                 assert( obj );
@@ -213 +375 @@
                 }
         }
+
+        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 = nullptr;
+                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/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