Changeset 90152a4 for src/SymTab/Validate.cc

Timestamp:

Aug 27, 2018, 4:40:34 PM (7 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

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

Children:

b7c89aa

Parents:

f9feab8 (diff), 305581d (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' into cleanup-dtors

File:

• src/SymTab/Validate.cc (modified) (44 diffs)

src/SymTab/Validate.cc

@@ -48 +48 @@
 #include "CodeGen/CodeGenerator.h"     // for genName
 #include "CodeGen/OperatorTable.h"     // for isCtorDtor, isCtorDtorAssign
+#include "ControlStruct/Mutate.h"      // for ForExprMutator
 #include "Common/PassVisitor.h"        // for PassVisitor, WithDeclsToAdd
 #include "Common/ScopedMap.h"          // for ScopedMap
@@ -60 +61 @@
 #include "Parser/LinkageSpec.h"        // for C
 #include "ResolvExpr/typeops.h"        // for typesCompatible
-#include "SymTab/AddVisit.h"           // for addVisit
+#include "ResolvExpr/Resolver.h"       // for findSingleExpression
+#include "ResolvExpr/ResolveTypeof.h"  // for resolveTypeof
 #include "SymTab/Autogen.h"            // for SizeType
 #include "SynTree/Attribute.h"         // for noAttributes, Attribute
@@ -72 +74 @@
 #include "SynTree/TypeSubstitution.h"  // for TypeSubstitution
 #include "SynTree/Visitor.h"           // for Visitor
+#include "Validate/HandleAttributes.h" // for handleAttributes
 
 class CompoundStmt;
@@ -77 +80 @@
 class SwitchStmt;
 
-
-#define debugPrint( x ) if ( doDebug ) { std::cout << x; }
+#define debugPrint( x ) if ( doDebug ) x
 
 namespace SymTab {
+        /// hoists declarations that are difficult to hoist while parsing
+        struct HoistTypeDecls final : public WithDeclsToAdd {
+                void previsit( SizeofExpr * );
+                void previsit( AlignofExpr * );
+                void previsit( UntypedOffsetofExpr * );
+                void previsit( CompoundLiteralExpr * );
+                void handleType( Type * );
+        };
+
+        struct FixQualifiedTypes final : public WithIndexer {
+                Type * postmutate( QualifiedType * );
+        };
+
         struct HoistStruct final : public WithDeclsToAdd, public WithGuards {
                 /// Flattens nested struct types
                 static void hoistStruct( std::list< Declaration * > &translationUnit );
 
-                void previsit( EnumInstType * enumInstType );
-                void previsit( StructInstType * structInstType );
-                void previsit( UnionInstType * unionInstType );
                 void previsit( StructDecl * aggregateDecl );
                 void previsit( UnionDecl * aggregateDecl );
+                void previsit( StaticAssertDecl * assertDecl );
+                void previsit( StructInstType * type );
+                void previsit( UnionInstType * type );
+                void previsit( EnumInstType * type );
 
           private:
                 template< typename AggDecl > void handleAggregate( AggDecl *aggregateDecl );
 
-                bool inStruct = false;
+                AggregateDecl * parentAggr = nullptr;
         };
 
@@ -112 +128 @@
 
         /// Associates forward declarations of aggregates with their definitions
-        struct LinkReferenceToTypes final : public WithIndexer, public WithGuards {
+        struct LinkReferenceToTypes final : public WithIndexer, public WithGuards, public WithVisitorRef<LinkReferenceToTypes>, public WithShortCircuiting {
                 LinkReferenceToTypes( const Indexer *indexer );
                 void postvisit( TypeInstType *typeInst );
@@ -120 +136 @@
                 void postvisit( UnionInstType *unionInst );
                 void postvisit( TraitInstType *traitInst );
+                void previsit( QualifiedType * qualType );
+                void postvisit( QualifiedType * qualType );
 
                 void postvisit( EnumDecl *enumDecl );
@@ -148 +166 @@
                 void previsit( ObjectDecl * object );
                 void previsit( FunctionDecl * func );
+                void previsit( FunctionType * ftype );
                 void previsit( StructDecl * aggrDecl );
                 void previsit( UnionDecl * aggrDecl );
@@ -164 +183 @@
         };
 
-        struct EliminateTypedef final : public WithVisitorRef<EliminateTypedef>, public WithGuards {
-                EliminateTypedef() : scopeLevel( 0 ) {}
+        struct ReplaceTypedef final : public WithVisitorRef<ReplaceTypedef>, public WithGuards, public WithShortCircuiting, public WithDeclsToAdd {
+                ReplaceTypedef() : scopeLevel( 0 ) {}
                 /// Replaces typedefs by forward declarations
-                static void eliminateTypedef( std::list< Declaration * > &translationUnit );
-
+                static void replaceTypedef( std::list< Declaration * > &translationUnit );
+
+                void premutate( QualifiedType * );
+                Type * postmutate( QualifiedType * qualType );
                 Type * postmutate( TypeInstType * aggregateUseType );
                 Declaration * postmutate( TypedefDecl * typeDecl );
@@ -179 +200 @@
 
                 void premutate( CompoundStmt * compoundStmt );
-                CompoundStmt * postmutate( CompoundStmt * compoundStmt );
 
                 void premutate( StructDecl * structDecl );
-                Declaration * postmutate( StructDecl * structDecl );
                 void premutate( UnionDecl * unionDecl );
-                Declaration * postmutate( UnionDecl * unionDecl );
                 void premutate( EnumDecl * enumDecl );
-                Declaration * postmutate( EnumDecl * enumDecl );
-                Declaration * postmutate( TraitDecl * contextDecl );
+                void premutate( TraitDecl * );
 
                 void premutate( FunctionType * ftype );
@@ -193 +210 @@
           private:
                 template<typename AggDecl>
-                AggDecl *handleAggregate( AggDecl * aggDecl );
-
-                template<typename AggDecl>
                 void addImplicitTypedef( AggDecl * aggDecl );
+                template< typename AggDecl >
+                void handleAggregate( AggDecl * aggr );
 
                 typedef std::unique_ptr<TypedefDecl> TypedefDeclPtr;
                 typedef ScopedMap< std::string, std::pair< TypedefDeclPtr, int > > TypedefMap;
-                typedef std::map< std::string, TypeDecl * > TypeDeclMap;
+                typedef ScopedMap< std::string, TypeDecl * > TypeDeclMap;
                 TypedefMap typedefNames;
                 TypeDeclMap typedeclNames;
                 int scopeLevel;
                 bool inFunctionType = false;
+        };
+
+        struct EliminateTypedef {
+                /// removes TypedefDecls from the AST
+                static void eliminateTypedef( std::list< Declaration * > &translationUnit );
+
+                template<typename AggDecl>
+                void handleAggregate( AggDecl *aggregateDecl );
+
+                void previsit( StructDecl * aggregateDecl );
+                void previsit( UnionDecl * aggregateDecl );
+                void previsit( CompoundStmt * compoundStmt );
         };
 
@@ -222 +250 @@
         };
 
-        struct ArrayLength {
+        struct FixObjectType : public WithIndexer {
+                /// resolves typeof type in object, function, and type declarations
+                static void fix( std::list< Declaration * > & translationUnit );
+
+                void previsit( ObjectDecl * );
+                void previsit( FunctionDecl * );
+                void previsit( TypeDecl * );
+        };
+
+        struct ArrayLength : public WithIndexer {
                 /// for array types without an explicit length, compute the length and store it so that it
                 /// is known to the rest of the phases. For example,
@@ -233 +270 @@
 
                 void previsit( ObjectDecl * objDecl );
+                void previsit( ArrayType * arrayType );
         };
 
@@ -262 +300 @@
                 PassVisitor<FindSpecialDeclarations> finder;
                 PassVisitor<LabelAddressFixer> labelAddrFixer;
-
-                EliminateTypedef::eliminateTypedef( translationUnit );
-                HoistStruct::hoistStruct( translationUnit ); // must happen after EliminateTypedef, so that aggregate typedefs occur in the correct order
+                PassVisitor<HoistTypeDecls> hoistDecls;
+                PassVisitor<FixQualifiedTypes> fixQual;
+
+                acceptAll( translationUnit, hoistDecls );
+                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, lrt ); // must happen before autogen, because sized flag needs to propagate to generated functions
+                mutateAll( translationUnit, fixQual ); // must happen after LinkReferenceToTypes, because aggregate members are accessed
+                HoistStruct::hoistStruct( translationUnit ); // must happen after EliminateTypedef, so that aggregate typedefs occur in the correct order
+                EliminateTypedef::eliminateTypedef( translationUnit ); //
                 acceptAll( translationUnit, genericParams );  // check as early as possible - can't happen before LinkReferenceToTypes
                 VerifyCtorDtorAssign::verify( translationUnit );  // must happen before autogen, because autogen examines existing ctor/dtors
@@ -274 +317 @@
                 Concurrency::applyKeywords( translationUnit );
                 acceptAll( translationUnit, fpd ); // must happen before autogenerateRoutines, after Concurrency::applyKeywords because uniqueIds must be set on declaration before resolution
+                ControlStruct::hoistControlDecls( translationUnit );  // hoist initialization out of for statements; must happen before autogenerateRoutines
                 autogenerateRoutines( translationUnit ); // moved up, used to be below compoundLiteral - currently needs EnumAndPointerDecay
                 Concurrency::implementMutexFuncs( translationUnit );
                 Concurrency::implementThreadStarter( translationUnit );
                 mutateAll( translationUnit, compoundliteral );
+                ResolvExpr::resolveWithExprs( translationUnit ); // must happen before FixObjectType because user-code is resolved and may contain with variables
+                FixObjectType::fix( translationUnit );
                 ArrayLength::computeLength( translationUnit );
                 acceptAll( translationUnit, finder ); // xxx - remove this pass soon
                 mutateAll( translationUnit, labelAddrFixer );
+                Validate::handleAttributes( translationUnit );
         }
 
@@ -292 +339 @@
         }
 
+
+        void HoistTypeDecls::handleType( Type * type ) {
+                // some type declarations are buried in expressions and not easy to hoist during parsing; hoist them here
+                AggregateDecl * aggr = nullptr;
+                if ( StructInstType * inst = dynamic_cast< StructInstType * >( type ) ) {
+                        aggr = inst->baseStruct;
+                } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( type ) ) {
+                        aggr = inst->baseUnion;
+                } else if ( EnumInstType * inst = dynamic_cast< EnumInstType * >( type ) ) {
+                        aggr = inst->baseEnum;
+                }
+                if ( aggr && aggr->body ) {
+                        declsToAddBefore.push_front( aggr );
+                }
+        }
+
+        void HoistTypeDecls::previsit( SizeofExpr * expr ) {
+                handleType( expr->type );
+        }
+
+        void HoistTypeDecls::previsit( AlignofExpr * expr ) {
+                handleType( expr->type );
+        }
+
+        void HoistTypeDecls::previsit( UntypedOffsetofExpr * expr ) {
+                handleType( expr->type );
+        }
+
+        void HoistTypeDecls::previsit( CompoundLiteralExpr * expr ) {
+                handleType( expr->result );
+        }
+
+
+        Type * FixQualifiedTypes::postmutate( QualifiedType * qualType ) {
+                Type * parent = qualType->parent;
+                Type * child = qualType->child;
+                if ( dynamic_cast< GlobalScopeType * >( qualType->parent ) ) {
+                        // .T => lookup T at global scope
+                        if ( TypeInstType * inst = dynamic_cast< TypeInstType * >( child ) ) {
+                                auto td = indexer.globalLookupType( inst->name );
+                                if ( ! td ) {
+                                        SemanticError( qualType->location, toString("Use of undefined global type ", inst->name) );
+                                }
+                                auto base = td->base;
+                                assert( base );
+                                Type * ret = base->clone();
+                                ret->get_qualifiers() = qualType->get_qualifiers();
+                                return ret;
+                        } else {
+                                // .T => T is not a type name
+                                assertf( false, "unhandled global qualified child type: %s", toCString(child) );
+                        }
+                } else {
+                        // S.T => S must be an aggregate type, find the declaration for T in S.
+                        AggregateDecl * aggr = nullptr;
+                        if ( StructInstType * inst = dynamic_cast< StructInstType * >( parent ) ) {
+                                aggr = inst->baseStruct;
+                        } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * > ( parent ) ) {
+                                aggr = inst->baseUnion;
+                        } else {
+                                SemanticError( qualType->location, toString("Qualified type requires an aggregate on the left, but has: ", parent) );
+                        }
+                        assert( aggr ); // TODO: need to handle forward declarations
+                        for ( Declaration * member : aggr->members ) {
+                                if ( StructInstType * inst = dynamic_cast< StructInstType * >( child ) ) {
+                                        if ( StructDecl * aggr = dynamic_cast< StructDecl * >( member ) ) {
+                                                if ( aggr->name == inst->name ) {
+                                                        // TODO: is this case, and other non-TypeInstType cases, necessary?
+                                                        return new StructInstType( qualType->get_qualifiers(), aggr );
+                                                }
+                                        }
+                                } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( child ) ) {
+                                        if ( UnionDecl * aggr = dynamic_cast< UnionDecl * > ( member ) ) {
+                                                if ( aggr->name == inst->name ) {
+                                                        return new UnionInstType( qualType->get_qualifiers(), aggr );
+                                                }
+                                        }
+                                } else if ( EnumInstType * inst = dynamic_cast< EnumInstType * >( child ) ) {
+                                        if ( EnumDecl * aggr = dynamic_cast< EnumDecl * > ( member ) ) {
+                                                if ( aggr->name == inst->name ) {
+                                                        return new EnumInstType( qualType->get_qualifiers(), aggr );
+                                                }
+                                        }
+                                } else if ( TypeInstType * inst = dynamic_cast< TypeInstType * >( child ) ) {
+                                        // name on the right is a typedef
+                                        if ( NamedTypeDecl * aggr = dynamic_cast< NamedTypeDecl * > ( member ) ) {
+                                                if ( aggr->name == inst->name ) {
+                                                        assert( aggr->base );
+                                                        Type * ret = aggr->base->clone();
+                                                        ret->get_qualifiers() = qualType->get_qualifiers();
+                                                        return ret;
+                                                }
+                                        }
+                                } else {
+                                        // S.T - S is not an aggregate => error
+                                        assertf( false, "unhandled qualified child type: %s", toCString(qualType) );
+                                }
+                        }
+                        // failed to find a satisfying definition of type
+                        SemanticError( qualType->location, toString("Undefined type in qualified type: ", qualType) );
+                }
+
+                // ... may want to link canonical SUE definition to each forward decl so that it becomes easier to lookup?
+        }
+
+
         void HoistStruct::hoistStruct( std::list< Declaration * > &translationUnit ) {
                 PassVisitor<HoistStruct> hoister;
@@ -297 +450 @@
         }
 
-        bool isStructOrUnion( Declaration *decl ) {
-                return dynamic_cast< StructDecl * >( decl ) || dynamic_cast< UnionDecl * >( decl );
+        bool shouldHoist( Declaration *decl ) {
+                return dynamic_cast< StructDecl * >( decl ) || dynamic_cast< UnionDecl * >( decl ) || dynamic_cast< StaticAssertDecl * >( decl );
+        }
+
+        namespace {
+                void qualifiedName( AggregateDecl * aggr, std::ostringstream & ss ) {
+                        if ( aggr->parent ) qualifiedName( aggr->parent, ss );
+                        ss << "__" << aggr->name;
+                }
+
+                // mangle nested type names using entire parent chain
+                std::string qualifiedName( AggregateDecl * aggr ) {
+                        std::ostringstream ss;
+                        qualifiedName( aggr, ss );
+                        return ss.str();
+                }
         }
 
         template< typename AggDecl >
         void HoistStruct::handleAggregate( AggDecl *aggregateDecl ) {
-                if ( inStruct ) {
+                if ( parentAggr ) {
+                        aggregateDecl->parent = parentAggr;
+                        aggregateDecl->name = qualifiedName( aggregateDecl );
                         // Add elements in stack order corresponding to nesting structure.
                         declsToAddBefore.push_front( aggregateDecl );
                 } else {
-                        GuardValue( inStruct );
-                        inStruct = true;
+                        GuardValue( parentAggr );
+                        parentAggr = aggregateDecl;
                 } // if
                 // Always remove the hoisted aggregate from the inner structure.
-                GuardAction( [aggregateDecl]() { filter( aggregateDecl->members, isStructOrUnion, false ); } );
-        }
-
-        void HoistStruct::previsit( EnumInstType * inst ) {
-                if ( inst->baseEnum ) {
-                        declsToAddBefore.push_front( inst->baseEnum );
-                }
-        }
-
-        void HoistStruct::previsit( StructInstType * inst ) {
-                if ( inst->baseStruct ) {
-                        declsToAddBefore.push_front( inst->baseStruct );
-                }
-        }
-
-        void HoistStruct::previsit( UnionInstType * inst ) {
-                if ( inst->baseUnion ) {
-                        declsToAddBefore.push_front( inst->baseUnion );
+                GuardAction( [aggregateDecl]() { filter( aggregateDecl->members, shouldHoist, false ); } );
+        }
+
+        void HoistStruct::previsit( StaticAssertDecl * assertDecl ) {
+                if ( parentAggr ) {
+                        declsToAddBefore.push_back( assertDecl );
                 }
         }
@@ -340 +497 @@
         }
 
+        void HoistStruct::previsit( StructInstType * type ) {
+                // need to reset type name after expanding to qualified name
+                assert( type->baseStruct );
+                type->name = type->baseStruct->name;
+        }
+
+        void HoistStruct::previsit( UnionInstType * type ) {
+                assert( type->baseUnion );
+                type->name = type->baseUnion->name;
+        }
+
+        void HoistStruct::previsit( EnumInstType * type ) {
+                assert( type->baseEnum );
+                type->name = type->baseEnum->name;
+        }
+
+
+        bool isTypedef( Declaration *decl ) {
+                return dynamic_cast< TypedefDecl * >( decl );
+        }
+
+        void EliminateTypedef::eliminateTypedef( std::list< Declaration * > &translationUnit ) {
+                PassVisitor<EliminateTypedef> eliminator;
+                acceptAll( translationUnit, eliminator );
+                filter( translationUnit, isTypedef, true );
+        }
+
+        template< typename AggDecl >
+        void EliminateTypedef::handleAggregate( AggDecl *aggregateDecl ) {
+                filter( aggregateDecl->members, isTypedef, true );
+        }
+
+        void EliminateTypedef::previsit( StructDecl * aggregateDecl ) {
+                handleAggregate( aggregateDecl );
+        }
+
+        void EliminateTypedef::previsit( UnionDecl * aggregateDecl ) {
+                handleAggregate( aggregateDecl );
+        }
+
+        void EliminateTypedef::previsit( CompoundStmt * compoundStmt ) {
+                // remove and delete decl stmts
+                filter( compoundStmt->kids, [](Statement * stmt) {
+                        if ( DeclStmt *declStmt = dynamic_cast< DeclStmt * >( stmt ) ) {
+                                if ( dynamic_cast< TypedefDecl * >( declStmt->decl ) ) {
+                                        return true;
+                                } // if
+                        } // if
+                        return false;
+                }, true);
+        }
+
         void EnumAndPointerDecay::previsit( EnumDecl *enumDecl ) {
                 // Set the type of each member of the enumeration to be EnumConstant
-                for ( std::list< Declaration * >::iterator i = enumDecl->get_members().begin(); i != enumDecl->get_members().end(); ++i ) {
+                for ( std::list< Declaration * >::iterator i = enumDecl->members.begin(); i != enumDecl->members.end(); ++i ) {
                         ObjectDecl * obj = dynamic_cast< ObjectDecl * >( *i );
                         assert( obj );
-                        obj->set_type( new EnumInstType( Type::Qualifiers( Type::Const ), enumDecl->get_name() ) );
+                        obj->set_type( new EnumInstType( Type::Qualifiers( Type::Const ), enumDecl->name ) );
                 } // for
         }
@@ -351 +560 @@
         namespace {
                 template< typename DWTList >
-                void fixFunctionList( DWTList & dwts, FunctionType * func ) {
-                        // the only case in which "void" is valid is where it is the only one in the list; then it should be removed
-                        // entirely. other fix ups are handled by the FixFunction class
-                        typedef typename DWTList::iterator DWTIterator;
-                        DWTIterator begin( dwts.begin() ), end( dwts.end() );
-                        if ( begin == end ) return;
-                        PassVisitor<FixFunction> fixer;
-                        DWTIterator i = begin;
-                        *i = (*i)->acceptMutator( fixer );
-                        if ( fixer.pass.isVoid ) {
-                                DWTIterator j = i;
-                                ++i;
-                                delete *j;
-                                dwts.erase( j );
-                                if ( i != end ) {
-                                        throw SemanticError( "invalid type void in function type ", func );
-                                } // if
-                        } else {
-                                ++i;
-                                for ( ; i != end; ++i ) {
-                                        PassVisitor<FixFunction> fixer;
-                                        *i = (*i)->acceptMutator( fixer );
-                                        if ( fixer.pass.isVoid ) {
-                                                throw SemanticError( "invalid type void in function type ", func );
-                                        } // if
-                                } // for
-                        } // if
+                void fixFunctionList( DWTList & dwts, bool isVarArgs, FunctionType * func ) {
+                        auto nvals = dwts.size();
+                        bool containsVoid = false;
+                        for ( auto & dwt : dwts ) {
+                                // fix each DWT and record whether a void was found
+                                containsVoid |= fixFunction( dwt );
+                        }
+
+                        // the only case in which "void" is valid is where it is the only one in the list
+                        if ( containsVoid && ( nvals > 1 || isVarArgs ) ) {
+                                SemanticError( func, "invalid type void in function type " );
+                        }
+
+                        // one void is the only thing in the list; remove it.
+                        if ( containsVoid ) {
+                                delete dwts.front();
+                                dwts.clear();
+                        }
                 }
         }
@@ -383 +583 @@
         void EnumAndPointerDecay::previsit( FunctionType *func ) {
                 // Fix up parameters and return types
-                fixFunctionList( func->get_parameters(), func );
-                fixFunctionList( func->get_returnVals(), func );
+                fixFunctionList( func->parameters, func->isVarArgs, func );
+                fixFunctionList( func->returnVals, false, func );
         }
 
@@ -396 +596 @@
 
         void LinkReferenceToTypes::postvisit( EnumInstType *enumInst ) {
-                EnumDecl *st = local_indexer->lookupEnum( enumInst->get_name() );
+                EnumDecl *st = local_indexer->lookupEnum( enumInst->name );
                 // it's not a semantic error if the enum is not found, just an implicit forward declaration
                 if ( st ) {
-                        //assert( ! enumInst->get_baseEnum() || enumInst->get_baseEnum()->get_members().empty() || ! st->get_members().empty() );
-                        enumInst->set_baseEnum( st );
-                } // if
-                if ( ! st || st->get_members().empty() ) {
+                        enumInst->baseEnum = st;
+                } // if
+                if ( ! st || ! st->body ) {
                         // use of forward declaration
-                        forwardEnums[ enumInst->get_name() ].push_back( enumInst );
+                        forwardEnums[ enumInst->name ].push_back( enumInst );
                 } // if
         }
@@ -411 +610 @@
                 for ( Expression * param : inst->parameters ) {
                         if ( ! dynamic_cast< TypeExpr * >( param ) ) {
-                                throw SemanticError( "Expression parameters for generic types are currently unsupported: ", inst );
+                                SemanticError( inst, "Expression parameters for generic types are currently unsupported: " );
                         }
                 }
@@ -417 +616 @@
 
         void LinkReferenceToTypes::postvisit( StructInstType *structInst ) {
-                StructDecl *st = local_indexer->lookupStruct( structInst->get_name() );
+                StructDecl *st = local_indexer->lookupStruct( structInst->name );
                 // it's not a semantic error if the struct is not found, just an implicit forward declaration
                 if ( st ) {
-                        //assert( ! structInst->get_baseStruct() || structInst->get_baseStruct()->get_members().empty() || ! st->get_members().empty() );
-                        structInst->set_baseStruct( st );
-                } // if
-                if ( ! st || st->get_members().empty() ) {
+                        structInst->baseStruct = st;
+                } // if
+                if ( ! st || ! st->body ) {
                         // use of forward declaration
-                        forwardStructs[ structInst->get_name() ].push_back( structInst );
+                        forwardStructs[ structInst->name ].push_back( structInst );
                 } // if
                 checkGenericParameters( structInst );
@@ -431 +629 @@
 
         void LinkReferenceToTypes::postvisit( UnionInstType *unionInst ) {
-                UnionDecl *un = local_indexer->lookupUnion( unionInst->get_name() );
+                UnionDecl *un = local_indexer->lookupUnion( unionInst->name );
                 // it's not a semantic error if the union is not found, just an implicit forward declaration
                 if ( un ) {
-                        unionInst->set_baseUnion( un );
-                } // if
-                if ( ! un || un->get_members().empty() ) {
+                        unionInst->baseUnion = un;
+                } // if
+                if ( ! un || ! un->body ) {
                         // use of forward declaration
-                        forwardUnions[ unionInst->get_name() ].push_back( unionInst );
+                        forwardUnions[ unionInst->name ].push_back( unionInst );
                 } // if
                 checkGenericParameters( unionInst );
+        }
+
+        void LinkReferenceToTypes::previsit( QualifiedType * ) {
+                visit_children = false;
+        }
+
+        void LinkReferenceToTypes::postvisit( QualifiedType * qualType ) {
+                // linking only makes sense for the 'oldest ancestor' of the qualified type
+                qualType->parent->accept( *visitor );
         }
 
@@ -451 +658 @@
                         DeclarationWithType * dwt2 = dynamic_cast<DeclarationWithType *>( d2 );
                         if ( dwt1 && dwt2 ) {
-                                if ( dwt1->get_name() == dwt2->get_name() && ResolvExpr::typesCompatible( dwt1->get_type(), dwt2->get_type(), SymTab::Indexer() ) ) {
+                                if ( dwt1->name == dwt2->name && ResolvExpr::typesCompatible( dwt1->get_type(), dwt2->get_type(), SymTab::Indexer() ) ) {
                                         // std::cerr << "=========== equal:" << std::endl;
                                         // std::cerr << "d1: " << d1 << std::endl;
@@ -476 +683 @@
         template< typename Iterator >
         void expandAssertions( TraitInstType * inst, Iterator out ) {
-                assertf( inst->baseTrait, "Trait instance not linked to base trait: %s", toString( inst ).c_str() );
+                assertf( inst->baseTrait, "Trait instance not linked to base trait: %s", toCString( inst ) );
                 std::list< DeclarationWithType * > asserts;
                 for ( Declaration * decl : inst->baseTrait->members ) {
@@ -511 +718 @@
                 TraitDecl *traitDecl = local_indexer->lookupTrait( traitInst->name );
                 if ( ! traitDecl ) {
-                        throw SemanticError( "use of undeclared trait " + traitInst->name );
-                } // if
-                if ( traitDecl->get_parameters().size() != traitInst->get_parameters().size() ) {
-                        throw SemanticError( "incorrect number of trait parameters: ", traitInst );
+                        SemanticError( traitInst->location, "use of undeclared trait " + traitInst->name );
+                } // if
+                if ( traitDecl->parameters.size() != traitInst->parameters.size() ) {
+                        SemanticError( traitInst, "incorrect number of trait parameters: " );
                 } // if
                 traitInst->baseTrait = traitDecl;
 
                 // need to carry over the 'sized' status of each decl in the instance
-                for ( auto p : group_iterate( traitDecl->get_parameters(), traitInst->get_parameters() ) ) {
+                for ( auto p : group_iterate( traitDecl->parameters, traitInst->parameters ) ) {
                         TypeExpr * expr = dynamic_cast< TypeExpr * >( std::get<1>(p) );
                         if ( ! expr ) {
-                                throw SemanticError( "Expression parameters for trait instances are currently unsupported: ", std::get<1>(p) );
+                                SemanticError( std::get<1>(p), "Expression parameters for trait instances are currently unsupported: " );
                         }
                         if ( TypeInstType * inst = dynamic_cast< TypeInstType * >( expr->get_type() ) ) {
                                 TypeDecl * formalDecl = std::get<0>(p);
-                                TypeDecl * instDecl = inst->get_baseType();
+                                TypeDecl * instDecl = inst->baseType;
                                 if ( formalDecl->get_sized() ) instDecl->set_sized( true );
                         }
@@ -535 +742 @@
         void LinkReferenceToTypes::postvisit( EnumDecl *enumDecl ) {
                 // visit enum members first so that the types of self-referencing members are updated properly
-                if ( ! enumDecl->get_members().empty() ) {
-                        ForwardEnumsType::iterator fwds = forwardEnums.find( enumDecl->get_name() );
+                if ( enumDecl->body ) {
+                        ForwardEnumsType::iterator fwds = forwardEnums.find( enumDecl->name );
                         if ( fwds != forwardEnums.end() ) {
                                 for ( std::list< EnumInstType * >::iterator inst = fwds->second.begin(); inst != fwds->second.end(); ++inst ) {
-                                        (*inst )->set_baseEnum( enumDecl );
+                                        (*inst)->baseEnum = enumDecl;
                                 } // for
                                 forwardEnums.erase( fwds );
                         } // if
+
+                        for ( Declaration * member : enumDecl->members ) {
+                                ObjectDecl * field = strict_dynamic_cast<ObjectDecl *>( member );
+                                if ( field->init ) {
+                                        // need to resolve enumerator initializers early so that other passes that determine if an expression is constexpr have the appropriate information.
+                                        SingleInit * init = strict_dynamic_cast<SingleInit *>( field->init );
+                                        ResolvExpr::findSingleExpression( init->value, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), indexer );
+                                }
+                        }
                 } // if
         }
@@ -575 +791 @@
                 // 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)
-                if ( ! structDecl->get_members().empty() ) {
-                        ForwardStructsType::iterator fwds = forwardStructs.find( structDecl->get_name() );
+                if ( structDecl->body ) {
+                        ForwardStructsType::iterator fwds = forwardStructs.find( structDecl->name );
                         if ( fwds != forwardStructs.end() ) {
                                 for ( std::list< StructInstType * >::iterator inst = fwds->second.begin(); inst != fwds->second.end(); ++inst ) {
-                                        (*inst )->set_baseStruct( structDecl );
+                                        (*inst)->baseStruct = structDecl;
                                 } // for
                                 forwardStructs.erase( fwds );
@@ -587 +803 @@
 
         void LinkReferenceToTypes::postvisit( UnionDecl *unionDecl ) {
-                if ( ! unionDecl->get_members().empty() ) {
-                        ForwardUnionsType::iterator fwds = forwardUnions.find( unionDecl->get_name() );
+                if ( unionDecl->body ) {
+                        ForwardUnionsType::iterator fwds = forwardUnions.find( unionDecl->name );
                         if ( fwds != forwardUnions.end() ) {
                                 for ( std::list< UnionInstType * >::iterator inst = fwds->second.begin(); inst != fwds->second.end(); ++inst ) {
-                                        (*inst )->set_baseUnion( unionDecl );
+                                        (*inst)->baseUnion = unionDecl;
                                 } // for
                                 forwardUnions.erase( fwds );
@@ -601 +817 @@
                 // ensure generic parameter instances are renamed like the base type
                 if ( inGeneric && typeInst->baseType ) typeInst->name = typeInst->baseType->name;
-                if ( NamedTypeDecl *namedTypeDecl = local_indexer->lookupType( typeInst->get_name() ) ) {
+                if ( NamedTypeDecl *namedTypeDecl = local_indexer->lookupType( typeInst->name ) ) {
                         if ( TypeDecl *typeDecl = dynamic_cast< TypeDecl * >( namedTypeDecl ) ) {
                                 typeInst->set_isFtype( typeDecl->get_kind() == TypeDecl::Ftype );
@@ -626 +842 @@
                         // apply FixFunction to every assertion to check for invalid void type
                         for ( DeclarationWithType *& assertion : type->assertions ) {
-                                PassVisitor<FixFunction> fixer;
-                                assertion = assertion->acceptMutator( fixer );
-                                if ( fixer.pass.isVoid ) {
-                                        throw SemanticError( "invalid type void in assertion of function ", node );
+                                bool isVoid = fixFunction( assertion );
+                                if ( isVoid ) {
+                                        SemanticError( node, "invalid type void in assertion of function " );
                                 } // if
                         } // for
@@ -637 +852 @@
 
         void ForallPointerDecay::previsit( ObjectDecl *object ) {
-                forallFixer( object->type->forall, object );
-                if ( PointerType *pointer = dynamic_cast< PointerType * >( object->type ) ) {
-                        forallFixer( pointer->base->forall, object );
-                } // if
+                // ensure that operator names only apply to functions or function pointers
+                if ( CodeGen::isOperator( object->name ) && ! dynamic_cast< FunctionType * >( object->type->stripDeclarator() ) ) {
+                        SemanticError( object->location, toCString( "operator ", object->name.c_str(), " is not a function or function pointer." )  );
+                }
                 object->fixUniqueId();
         }
 
         void ForallPointerDecay::previsit( FunctionDecl *func ) {
-                forallFixer( func->type->forall, func );
                 func->fixUniqueId();
+        }
+
+        void ForallPointerDecay::previsit( FunctionType * ftype ) {
+                forallFixer( ftype->forall, ftype );
         }
 
@@ -673 +891 @@
                 // were cast to void.
                 if ( ! returnStmt->get_expr() && returnVals.size() != 0 ) {
-                        throw SemanticError( "Non-void function returns no values: " , returnStmt );
-                }
-        }
-
-
-        bool isTypedef( Declaration *decl ) {
-                return dynamic_cast< TypedefDecl * >( decl );
-        }
-
-        void EliminateTypedef::eliminateTypedef( std::list< Declaration * > &translationUnit ) {
-                PassVisitor<EliminateTypedef> eliminator;
+                        SemanticError( returnStmt, "Non-void function returns no values: " );
+                }
+        }
+
+
+        void ReplaceTypedef::replaceTypedef( std::list< Declaration * > &translationUnit ) {
+                PassVisitor<ReplaceTypedef> eliminator;
                 mutateAll( translationUnit, eliminator );
                 if ( eliminator.pass.typedefNames.count( "size_t" ) ) {
                         // grab and remember declaration of size_t
-                        SizeType = eliminator.pass.typedefNames["size_t"].first->get_base()->clone();
+                        SizeType = eliminator.pass.typedefNames["size_t"].first->base->clone();
                 } else {
                         // xxx - missing global typedef for size_t - default to long unsigned int, even though that may be wrong
@@ -693 +907 @@
                         SizeType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );
                 }
-                filter( translationUnit, isTypedef, true );
-        }
-
-        Type * EliminateTypedef::postmutate( TypeInstType * typeInst ) {
+        }
+
+        void ReplaceTypedef::premutate( QualifiedType * ) {
+                visit_children = false;
+        }
+
+        Type * ReplaceTypedef::postmutate( QualifiedType * qualType ) {
+                // replacing typedefs only makes sense for the 'oldest ancestor' of the qualified type
+                qualType->parent = qualType->parent->acceptMutator( *visitor );
+                return qualType;
+        }
+
+        Type * ReplaceTypedef::postmutate( TypeInstType * typeInst ) {
                 // instances of typedef types will come here. If it is an instance
                 // of a typdef type, link the instance to its actual type.
-                TypedefMap::const_iterator def = typedefNames.find( typeInst->get_name() );
+                TypedefMap::const_iterator def = typedefNames.find( typeInst->name );
                 if ( def != typedefNames.end() ) {
                         Type *ret = def->second.first->base->clone();
+                        ret->location = typeInst->location;
                         ret->get_qualifiers() |= typeInst->get_qualifiers();
                         // attributes are not carried over from typedef to function parameters/return values
@@ -714 +938 @@
                                 ReferenceToType *rtt = dynamic_cast<ReferenceToType*>(ret);
                                 if ( ! rtt ) {
-                                        throw SemanticError("Cannot apply type parameters to base type of " + typeInst->name);
+                                        SemanticError( typeInst->location, "Cannot apply type parameters to base type of " + typeInst->name );
                                 }
-                                rtt->get_parameters().clear();
+                                rtt->parameters.clear();
                                 cloneAll( typeInst->parameters, rtt->parameters );
                                 mutateAll( rtt->parameters, *visitor );  // recursively fix typedefs on parameters
@@ -723 +947 @@
                         return ret;
                 } else {
-                        TypeDeclMap::const_iterator base = typedeclNames.find( typeInst->get_name() );
-                        assertf( base != typedeclNames.end(), "Cannot find typedecl name %s", typeInst->name.c_str() );
+                        TypeDeclMap::const_iterator base = typedeclNames.find( typeInst->name );
+                        if ( base == typedeclNames.end() ) {
+                                SemanticError( typeInst->location, toString("Use of undefined type ", typeInst->name) );
+                        }
                         typeInst->set_baseType( base->second );
-                } // if
-                return typeInst;
+                        return typeInst;
+                } // if
+                assert( false );
         }
 
@@ -744 +971 @@
         }
 
-        Declaration *EliminateTypedef::postmutate( TypedefDecl * tyDecl ) {
-                if ( typedefNames.count( tyDecl->get_name() ) == 1 && typedefNames[ tyDecl->get_name() ].second == scopeLevel ) {
+        Declaration * ReplaceTypedef::postmutate( TypedefDecl * tyDecl ) {
+                if ( typedefNames.count( tyDecl->name ) == 1 && typedefNames[ tyDecl->name ].second == scopeLevel ) {
                         // typedef to the same name from the same scope
                         // must be from the same type
 
-                        Type * t1 = tyDecl->get_base();
-                        Type * t2 = typedefNames[ tyDecl->get_name() ].first->get_base();
+                        Type * t1 = tyDecl->base;
+                        Type * t2 = typedefNames[ tyDecl->name ].first->base;
                         if ( ! ResolvExpr::typesCompatible( t1, t2, Indexer() ) ) {
-                                throw SemanticError( "Cannot redefine typedef: " + tyDecl->name );
-                        }
-                        // cannot redefine VLA typedefs
+                                SemanticError( tyDecl->location, "Cannot redefine typedef: " + tyDecl->name );
+                        }
+                        // Cannot redefine VLA typedefs. Note: this is slightly incorrect, because our notion of VLAs
+                        // at this point in the translator is imprecise. In particular, this will disallow redefining typedefs
+                        // with arrays whose dimension is an enumerator or a cast of a constant/enumerator. The effort required
+                        // to fix this corner case likely outweighs the utility of allowing it.
                         if ( isVariableLength( t1 ) || isVariableLength( t2 ) ) {
-                                throw SemanticError( "Cannot redefine typedef: " + tyDecl->name );
+                                SemanticError( tyDecl->location, "Cannot redefine typedef: " + tyDecl->name );
                         }
                 } else {
-                        typedefNames[ tyDecl->get_name() ] = std::make_pair( TypedefDeclPtr( tyDecl ), scopeLevel );
+                        typedefNames[ tyDecl->name ] = std::make_pair( TypedefDeclPtr( tyDecl ), scopeLevel );
                 } // if
 
@@ -771 +1001 @@
                 // Note, qualifiers on the typedef are superfluous for the forward declaration.
 
-                Type *designatorType = tyDecl->get_base()->stripDeclarator();
+                Type *designatorType = tyDecl->base->stripDeclarator();
                 if ( StructInstType *aggDecl = dynamic_cast< StructInstType * >( designatorType ) ) {
-                        return new StructDecl( aggDecl->get_name(), DeclarationNode::Struct, noAttributes, tyDecl->get_linkage() );
+                        declsToAddBefore.push_back( new StructDecl( aggDecl->name, DeclarationNode::Struct, noAttributes, tyDecl->linkage ) );
                 } else if ( UnionInstType *aggDecl = dynamic_cast< UnionInstType * >( designatorType ) ) {
-                        return new UnionDecl( aggDecl->get_name(), noAttributes, tyDecl->get_linkage() );
+                        declsToAddBefore.push_back( new UnionDecl( aggDecl->name, noAttributes, tyDecl->linkage ) );
                 } else if ( EnumInstType *enumDecl = dynamic_cast< EnumInstType * >( designatorType ) ) {
-                        return new EnumDecl( enumDecl->get_name(), noAttributes, tyDecl->get_linkage() );
-                } else {
-                        return tyDecl->clone();
-                } // if
-        }
-
-        void EliminateTypedef::premutate( TypeDecl * typeDecl ) {
-                TypedefMap::iterator i = typedefNames.find( typeDecl->get_name() );
+                        declsToAddBefore.push_back( new EnumDecl( enumDecl->name, noAttributes, tyDecl->linkage ) );
+                } // if
+                return tyDecl->clone();
+        }
+
+        void ReplaceTypedef::premutate( TypeDecl * typeDecl ) {
+                TypedefMap::iterator i = typedefNames.find( typeDecl->name );
                 if ( i != typedefNames.end() ) {
                         typedefNames.erase( i ) ;
                 } // if
 
-                typedeclNames[ typeDecl->get_name() ] = typeDecl;
-        }
-
-        void EliminateTypedef::premutate( FunctionDecl * ) {
+                typedeclNames.insert( typeDecl->name, typeDecl );
+        }
+
+        void ReplaceTypedef::premutate( FunctionDecl * ) {
                 GuardScope( typedefNames );
-        }
-
-        void EliminateTypedef::premutate( ObjectDecl * ) {
+                GuardScope( typedeclNames );
+        }
+
+        void ReplaceTypedef::premutate( ObjectDecl * ) {
                 GuardScope( typedefNames );
-        }
-
-        DeclarationWithType *EliminateTypedef::postmutate( ObjectDecl * objDecl ) {
-                if ( FunctionType *funtype = dynamic_cast<FunctionType *>( objDecl->get_type() ) ) { // function type?
+                GuardScope( typedeclNames );
+        }
+
+        DeclarationWithType * ReplaceTypedef::postmutate( ObjectDecl * objDecl ) {
+                if ( FunctionType *funtype = dynamic_cast<FunctionType *>( objDecl->type ) ) { // function type?
                         // replace the current object declaration with a function declaration
-                        FunctionDecl * newDecl = new FunctionDecl( objDecl->get_name(), objDecl->get_storageClasses(), objDecl->get_linkage(), funtype, 0, objDecl->get_attributes(), objDecl->get_funcSpec() );
-                        objDecl->get_attributes().clear();
+                        FunctionDecl * newDecl = new FunctionDecl( objDecl->name, objDecl->get_storageClasses(), objDecl->linkage, funtype, 0, objDecl->attributes, objDecl->get_funcSpec() );
+                        objDecl->attributes.clear();
                         objDecl->set_type( nullptr );
                         delete objDecl;
@@ -812 +1043 @@
         }
 
-        void EliminateTypedef::premutate( CastExpr * ) {
+        void ReplaceTypedef::premutate( CastExpr * ) {
                 GuardScope( typedefNames );
-        }
-
-        void EliminateTypedef::premutate( CompoundStmt * ) {
+                GuardScope( typedeclNames );
+        }
+
+        void ReplaceTypedef::premutate( CompoundStmt * ) {
                 GuardScope( typedefNames );
+                GuardScope( typedeclNames );
                 scopeLevel += 1;
                 GuardAction( [this](){ scopeLevel -= 1; } );
         }
 
-        CompoundStmt *EliminateTypedef::postmutate( CompoundStmt * compoundStmt ) {
-                // remove and delete decl stmts
-                filter( compoundStmt->kids, [](Statement * stmt) {
-                        if ( DeclStmt *declStmt = dynamic_cast< DeclStmt * >( stmt ) ) {
-                                if ( dynamic_cast< TypedefDecl * >( declStmt->get_decl() ) ) {
-                                        return true;
-                                } // if
-                        } // if
-                        return false;
-                }, true);
-                return compoundStmt;
-        }
-
-        // there may be typedefs nested within aggregates. in order for everything to work properly, these should be removed
-        // as well
         template<typename AggDecl>
-        AggDecl *EliminateTypedef::handleAggregate( AggDecl * aggDecl ) {
-                filter( aggDecl->members, isTypedef, true );
-                return aggDecl;
-        }
-
-        template<typename AggDecl>
-        void EliminateTypedef::addImplicitTypedef( AggDecl * aggDecl ) {
+        void ReplaceTypedef::addImplicitTypedef( AggDecl * aggDecl ) {
                 if ( typedefNames.count( aggDecl->get_name() ) == 0 ) {
                         Type *type = nullptr;
@@ -854 +1066 @@
                                 type = new EnumInstType( Type::Qualifiers(), newDeclEnumDecl->get_name() );
                         } // if
-                        TypedefDeclPtr tyDecl( new TypedefDecl( aggDecl->get_name(), Type::StorageClasses(), type, aggDecl->get_linkage() ) );
+                        TypedefDeclPtr tyDecl( new TypedefDecl( aggDecl->get_name(), aggDecl->location, Type::StorageClasses(), type, aggDecl->get_linkage() ) );
                         typedefNames[ aggDecl->get_name() ] = std::make_pair( std::move( tyDecl ), scopeLevel );
-                } // if
-        }
-
-        void EliminateTypedef::premutate( StructDecl * structDecl ) {
+                        // add the implicit typedef to the AST
+                        declsToAddBefore.push_back( new TypedefDecl( aggDecl->get_name(), aggDecl->location, Type::StorageClasses(), type->clone(), aggDecl->get_linkage() ) );
+                } // if
+        }
+
+        template< typename AggDecl >
+        void ReplaceTypedef::handleAggregate( AggDecl * aggr ) {
+                SemanticErrorException errors;
+
+                ValueGuard< std::list<Declaration * > > oldBeforeDecls( declsToAddBefore );
+                ValueGuard< std::list<Declaration * > > oldAfterDecls ( declsToAddAfter  );
+                declsToAddBefore.clear();
+                declsToAddAfter.clear();
+
+                GuardScope( typedefNames );
+                GuardScope( typedeclNames );
+                mutateAll( aggr->parameters, *visitor );
+
+                // unroll mutateAll for aggr->members so that implicit typedefs for nested types are added to the aggregate body.
+                for ( std::list< Declaration * >::iterator i = aggr->members.begin(); i != aggr->members.end(); ++i ) {
+                        if ( !declsToAddAfter.empty() ) { aggr->members.splice( i, declsToAddAfter ); }
+
+                        try {
+                                *i = maybeMutate( *i, *visitor );
+                        } catch ( SemanticErrorException &e ) {
+                                errors.append( e );
+                        }
+
+                        if ( !declsToAddBefore.empty() ) { aggr->members.splice( i, declsToAddBefore ); }
+                }
+
+                if ( !declsToAddAfter.empty() ) { aggr->members.splice( aggr->members.end(), declsToAddAfter ); }
+                if ( !errors.isEmpty() ) { throw errors; }
+        }
+
+        void ReplaceTypedef::premutate( StructDecl * structDecl ) {
+                visit_children = false;
                 addImplicitTypedef( structDecl );
-        }
-
-
-        Declaration *EliminateTypedef::postmutate( StructDecl * structDecl ) {
-                return handleAggregate( structDecl );
-        }
-
-        void EliminateTypedef::premutate( UnionDecl * unionDecl ) {
+                handleAggregate( structDecl );
+        }
+
+        void ReplaceTypedef::premutate( UnionDecl * unionDecl ) {
+                visit_children = false;
                 addImplicitTypedef( unionDecl );
-        }
-
-        Declaration *EliminateTypedef::postmutate( UnionDecl * unionDecl ) {
-                return handleAggregate( unionDecl );
-        }
-
-        void EliminateTypedef::premutate( EnumDecl * enumDecl ) {
+                handleAggregate( unionDecl );
+        }
+
+        void ReplaceTypedef::premutate( EnumDecl * enumDecl ) {
                 addImplicitTypedef( enumDecl );
         }
 
-        Declaration *EliminateTypedef::postmutate( EnumDecl * enumDecl ) {
-                return handleAggregate( enumDecl );
-        }
-
-        Declaration *EliminateTypedef::postmutate( TraitDecl * traitDecl ) {
-                return handleAggregate( traitDecl );
-        }
-
-        void EliminateTypedef::premutate( FunctionType * ) {
+        void ReplaceTypedef::premutate( FunctionType * ) {
                 GuardValue( inFunctionType );
                 inFunctionType = true;
+        }
+
+        void ReplaceTypedef::premutate( TraitDecl * ) {
+                GuardScope( typedefNames );
+                GuardScope( typedeclNames);
         }
 
@@ -905 +1141 @@
                 if ( CodeGen::isCtorDtorAssign( funcDecl->get_name() ) ) { // TODO: also check /=, etc.
                         if ( params.size() == 0 ) {
-                                throw SemanticError( "Constructors, destructors, and assignment functions require at least one parameter ", funcDecl );
+                                SemanticError( funcDecl, "Constructors, destructors, and assignment functions require at least one parameter " );
                         }
                         ReferenceType * refType = dynamic_cast< ReferenceType * >( params.front()->get_type() );
                         if ( ! refType ) {
-                                throw SemanticError( "First parameter of a constructor, destructor, or assignment function must be a reference ", funcDecl );
+                                SemanticError( funcDecl, "First parameter of a constructor, destructor, or assignment function must be a reference " );
                         }
                         if ( CodeGen::isCtorDtor( funcDecl->get_name() ) && returnVals.size() != 0 ) {
-                                throw SemanticError( "Constructors and destructors cannot have explicit return values ", funcDecl );
+                                SemanticError( funcDecl, "Constructors and destructors cannot have explicit return values " );
                         }
                 }
@@ -947 +1183 @@
 
                         sub.apply( inst );
-                        if ( args.size() < params->size() ) throw SemanticError( "Too few type arguments in generic type ", inst );
-                        if ( args.size() > params->size() ) throw SemanticError( "Too many type arguments in generic type ", inst );
+                        if ( args.size() < params->size() ) SemanticError( inst, "Too few type arguments in generic type " );
+                        if ( args.size() > params->size() ) SemanticError( inst, "Too many type arguments in generic type " );
                 }
         }
@@ -1014 +1250 @@
         }
 
+        void FixObjectType::fix( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<FixObjectType> fixer;
+                acceptAll( translationUnit, fixer );
+        }
+
+        void FixObjectType::previsit( ObjectDecl * objDecl ) {
+                Type *new_type = ResolvExpr::resolveTypeof( objDecl->get_type(), indexer );
+                new_type->get_qualifiers() -= Type::Lvalue; // even if typeof is lvalue, variable can never have lvalue-qualified type
+                objDecl->set_type( new_type );
+        }
+
+        void FixObjectType::previsit( FunctionDecl * funcDecl ) {
+                Type *new_type = ResolvExpr::resolveTypeof( funcDecl->type, indexer );
+                new_type->get_qualifiers() -= Type::Lvalue; // even if typeof is lvalue, variable can never have lvalue-qualified type
+                funcDecl->set_type( new_type );
+        }
+
+        void FixObjectType::previsit( TypeDecl *typeDecl ) {
+                if ( typeDecl->get_base() ) {
+                        Type *new_type = ResolvExpr::resolveTypeof( typeDecl->get_base(), indexer );
+                        new_type->get_qualifiers() -= Type::Lvalue; // even if typeof is lvalue, variable can never have lvalue-qualified type
+                        typeDecl->set_base( new_type );
+                } // if
+        }
+
         void ArrayLength::computeLength( std::list< Declaration * > & translationUnit ) {
                 PassVisitor<ArrayLength> len;
@@ -1020 +1281 @@
 
         void ArrayLength::previsit( ObjectDecl * objDecl ) {
-                if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->get_type() ) ) {
-                        if ( at->get_dimension() ) return;
-                        if ( ListInit * init = dynamic_cast< ListInit * >( objDecl->get_init() ) ) {
-                                at->set_dimension( new ConstantExpr( Constant::from_ulong( init->get_initializers().size() ) ) );
-                        }
+                if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->type ) ) {
+                        if ( at->dimension ) return;
+                        if ( ListInit * init = dynamic_cast< ListInit * >( objDecl->init ) ) {
+                                at->dimension = new ConstantExpr( Constant::from_ulong( init->initializers.size() ) );
+                        }
+                }
+        }
+
+        void ArrayLength::previsit( ArrayType * type ) {
+                if ( type->dimension ) {
+                        // need to resolve array dimensions early so that constructor code can correctly determine
+                        // if a type is a VLA (and hence whether its elements need to be constructed)
+                        ResolvExpr::findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
+
+                        // must re-evaluate whether a type is a VLA, now that more information is available
+                        // (e.g. the dimension may have been an enumerator, which was unknown prior to this step)
+                        type->isVarLen = ! InitTweak::isConstExpr( type->dimension );
                 }
         }