source: src/GenPoly/Box.cc@ d75038c

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Box.cc --
//
// Author           : Richard C. Bilson
// Created On       : Mon May 18 07:44:20 2015
// Last Modified By : Peter A. Buhr
// Last Modified On : Fri Feb  5 16:45:07 2016
// Update Count     : 286
//

#include <algorithm>
#include <iterator>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#include <cassert>

#include "Box.h"
#include "DeclMutator.h"
#include "PolyMutator.h"
#include "FindFunction.h"
#include "ScopedMap.h"
#include "ScopedSet.h"
#include "ScrubTyVars.h"

#include "Parser/ParseNode.h"

#include "SynTree/Constant.h"
#include "SynTree/Declaration.h"
#include "SynTree/Expression.h"
#include "SynTree/Initializer.h"
#include "SynTree/Mutator.h"
#include "SynTree/Statement.h"
#include "SynTree/Type.h"
#include "SynTree/TypeSubstitution.h"

#include "ResolvExpr/TypeEnvironment.h"
#include "ResolvExpr/TypeMap.h"
#include "ResolvExpr/typeops.h"

#include "SymTab/Indexer.h"
#include "SymTab/Mangler.h"

#include "Common/SemanticError.h"
#include "Common/UniqueName.h"
#include "Common/utility.h"

#include <ext/functional> // temporary

namespace GenPoly {
        namespace {
                const std::list<Label> noLabels;

                FunctionType *makeAdapterType( FunctionType *adaptee, const TyVarMap &tyVars );

                /// Abstracts type equality for a list of parameter types
                struct TypeList {
                        TypeList() : params() {}
                        TypeList( const std::list< Type* > &_params ) : params() { cloneAll(_params, params); }
                        TypeList( std::list< Type* > &&_params ) : params( _params ) {}

                        TypeList( const TypeList &that ) : params() { cloneAll(that.params, params); }
                        TypeList( TypeList &&that ) : params( std::move( that.params ) ) {}

                        /// Extracts types from a list of TypeExpr*
                        TypeList( const std::list< TypeExpr* >& _params ) : params() {
                                for ( std::list< TypeExpr* >::const_iterator param = _params.begin(); param != _params.end(); ++param ) {
                                        params.push_back( (*param)->get_type()->clone() );
                                }
                        }

                        TypeList& operator= ( const TypeList &that ) {
                                deleteAll( params );

                                params.clear();
                                cloneAll( that.params, params );

                                return *this;
                        }

                        TypeList& operator= ( TypeList &&that ) {
                                deleteAll( params );

                                params = std::move( that.params );

                                return *this;
                        }

                        ~TypeList() { deleteAll( params ); }

                        bool operator== ( const TypeList& that ) const {
                                if ( params.size() != that.params.size() ) return false;

                                SymTab::Indexer dummy;
                                for ( std::list< Type* >::const_iterator it = params.begin(), jt = that.params.begin(); it != params.end(); ++it, ++jt ) {
                                        if ( ! ResolvExpr::typesCompatible( *it, *jt, dummy ) ) return false;
                                }
                                return true;
                        }

                        std::list< Type* > params;  ///< Instantiation parameters
                };

                /// Maps a key and a TypeList to the some value, accounting for scope
                template< typename Key, typename Value >
                class InstantiationMap {
                        /// Wraps value for a specific (Key, TypeList) combination
                        typedef std::pair< TypeList, Value* > Instantiation;
                        /// List of TypeLists paired with their appropriate values
                        typedef std::vector< Instantiation > ValueList;
                        /// Underlying map type; maps keys to a linear list of corresponding TypeLists and values
                        typedef ScopedMap< Key*, ValueList > InnerMap;

                        InnerMap instantiations;  ///< instantiations

                public:
                        /// Starts a new scope
                        void beginScope() { instantiations.beginScope(); }

                        /// Ends a scope
                        void endScope() { instantiations.endScope(); }

                        /// Gets the value for the (key, typeList) pair, returns NULL on none such.
                        Value *lookup( Key *key, const std::list< TypeExpr* >& params ) const {
                                TypeList typeList( params );
                                
                                // scan scopes for matches to the key
                                for ( typename InnerMap::const_iterator insts = instantiations.find( key ); insts != instantiations.end(); insts = instantiations.findNext( insts, key ) ) {
                                        for ( typename ValueList::const_reverse_iterator inst = insts->second.rbegin(); inst != insts->second.rend(); ++inst ) {
                                                if ( inst->first == typeList ) return inst->second;
                                        }
                                }
                                // no matching instantiations found
                                return 0;
                        }

                        /// Adds a value for a (key, typeList) pair to the current scope
                        void insert( Key *key, const std::list< TypeExpr* > &params, Value *value ) {
                                instantiations[ key ].push_back( Instantiation( TypeList( params ), value ) );
                        }
                };

                /// Adds layout-generation functions to polymorphic types
                class LayoutFunctionBuilder : public DeclMutator {
                        unsigned int functionNesting;  // current level of nested functions
                public:
                        LayoutFunctionBuilder() : functionNesting( 0 ) {}

                        virtual DeclarationWithType *mutate( FunctionDecl *functionDecl );
                        virtual Declaration *mutate( StructDecl *structDecl );
                        virtual Declaration *mutate( UnionDecl *unionDecl );
                };
                
                /// Replaces polymorphic return types with out-parameters, replaces calls to polymorphic functions with adapter calls as needed, and adds appropriate type variables to the function call
                class Pass1 : public PolyMutator {
                  public:
                        Pass1();
                        virtual Expression *mutate( ApplicationExpr *appExpr );
                        virtual Expression *mutate( AddressExpr *addrExpr );
                        virtual Expression *mutate( UntypedExpr *expr );
                        virtual DeclarationWithType* mutate( FunctionDecl *functionDecl );
                        virtual TypeDecl *mutate( TypeDecl *typeDecl );
                        virtual Expression *mutate( CommaExpr *commaExpr );
                        virtual Expression *mutate( ConditionalExpr *condExpr );
                        virtual Statement * mutate( ReturnStmt *returnStmt );
                        virtual Type *mutate( PointerType *pointerType );
                        virtual Type * mutate( FunctionType *functionType );

                        virtual void doBeginScope();
                        virtual void doEndScope();
                  private:
                        /// Pass the extra type parameters from polymorphic generic arguments or return types into a function application
                        void passArgTypeVars( ApplicationExpr *appExpr, Type *parmType, Type *argBaseType, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars, std::set< std::string > &seenTypes );
                        /// passes extra type parameters into a polymorphic function application
                        void passTypeVars( ApplicationExpr *appExpr, ReferenceToType *polyRetType, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars );
                        /// wraps a function application with a new temporary for the out-parameter return value
                        Expression *addRetParam( ApplicationExpr *appExpr, FunctionType *function, Type *retType, std::list< Expression *>::iterator &arg );
                        /// Replaces all the type parameters of a generic type with their concrete equivalents under the current environment
                        void replaceParametersWithConcrete( ApplicationExpr *appExpr, std::list< Expression* >& params );
                        /// Replaces a polymorphic type with its concrete equivalant under the current environment (returns itself if concrete).
                        /// If `doClone` is set to false, will not clone interior types
                        Type *replaceWithConcrete( ApplicationExpr *appExpr, Type *type, bool doClone = true );
                        /// wraps a function application returning a polymorphic type with a new temporary for the out-parameter return value
                        Expression *addPolyRetParam( ApplicationExpr *appExpr, FunctionType *function, ReferenceToType *polyType, std::list< Expression *>::iterator &arg );
                        Expression *applyAdapter( ApplicationExpr *appExpr, FunctionType *function, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars );
                        void boxParam( Type *formal, Expression *&arg, const TyVarMap &exprTyVars );
                        void boxParams( ApplicationExpr *appExpr, FunctionType *function, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars );
                        void addInferredParams( ApplicationExpr *appExpr, FunctionType *functionType, std::list< Expression *>::iterator &arg, const TyVarMap &tyVars );
                        /// Stores assignment operators from assertion list in local map of assignment operations
                        void findAssignOps( const std::list< TypeDecl *> &forall );
                        void passAdapters( ApplicationExpr *appExpr, FunctionType *functionType, const TyVarMap &exprTyVars );
                        FunctionDecl *makeAdapter( FunctionType *adaptee, FunctionType *realType, const std::string &mangleName, const TyVarMap &tyVars );
                        /// Replaces intrinsic operator functions with their arithmetic desugaring
                        Expression *handleIntrinsics( ApplicationExpr *appExpr );
                        /// Inserts a new temporary variable into the current scope with an auto-generated name
                        ObjectDecl *makeTemporary( Type *type );

                        std::map< std::string, DeclarationWithType *> assignOps;     ///< Currently known type variable assignment operators
                        ResolvExpr::TypeMap< DeclarationWithType > scopedAssignOps;  ///< Currently known assignment operators
                        ScopedMap< std::string, DeclarationWithType* > adapters;     ///< Set of adapter functions in the current scope
                        
                        DeclarationWithType *retval;
                        bool useRetval;
                        UniqueName tempNamer;
                };

                /// * Moves polymorphic returns in function types to pointer-type parameters
                /// * adds type size and assertion parameters to parameter lists
                /// * does dynamic calculation of type layouts
                class Pass2 : public PolyMutator {
                  public:
                        template< typename DeclClass >
                        DeclClass *handleDecl( DeclClass *decl, Type *type );
                        virtual DeclarationWithType *mutate( FunctionDecl *functionDecl );
                        virtual ObjectDecl *mutate( ObjectDecl *objectDecl );
                        virtual TypeDecl *mutate( TypeDecl *typeDecl );
                        virtual TypedefDecl *mutate( TypedefDecl *typedefDecl );
                        virtual Type *mutate( PointerType *pointerType );
                        virtual Type *mutate( FunctionType *funcType );
                        virtual Expression *mutate( SizeofExpr *sizeofExpr );
                        virtual Expression *mutate( AlignofExpr *alignofExpr );
                        virtual Expression *mutate( OffsetofExpr *offsetofExpr );
                        virtual Expression *mutate( OffsetPackExpr *offsetPackExpr );

                        virtual void doBeginScope();
                        virtual void doEndScope();
                  private:
                        void addAdapters( FunctionType *functionType );
                        /// Makes a new variable in the current scope with the given name, type & optional initializer
                        ObjectDecl *makeVar( const std::string &name, Type *type, Initializer *init = 0 );
                        /// returns true if the type has a dynamic layout; such a layout will be stored in appropriately-named local variables when the function returns
                        bool findGeneric( Type *ty );
                        /// adds type parameters to the layout call; will generate the appropriate parameters if needed
                        void addOtypeParamsToLayoutCall( UntypedExpr *layoutCall, const std::list< Type* > &otypeParams );

                        std::map< UniqueId, std::string > adapterName;
                        ScopedSet< std::string > knownLayouts;          ///< Set of generic type layouts known in the current scope, indexed by sizeofName
                        ScopedSet< std::string > knownOffsets;          ///< Set of non-generic types for which the offset array exists in the current scope, indexed by offsetofName
                };

                /// Mutator pass that replaces concrete instantiations of generic types with actual struct declarations, scoped appropriately
                class GenericInstantiator : public DeclMutator {
                        /// Map of (generic type, parameter list) pairs to concrete type instantiations
                        InstantiationMap< AggregateDecl, AggregateDecl > instantiations;
                        /// Namer for concrete types
                        UniqueName typeNamer;

                public:
                        GenericInstantiator() : DeclMutator(), instantiations(), typeNamer("_conc_") {}

                        virtual Type* mutate( StructInstType *inst );
                        virtual Type* mutate( UnionInstType *inst );

        //              virtual Expression* mutate( MemberExpr *memberExpr );

                        virtual void doBeginScope();
                        virtual void doEndScope();
                private:
                        /// Wrap instantiation lookup for structs
                        StructDecl* lookup( StructInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (StructDecl*)instantiations.lookup( inst->get_baseStruct(), typeSubs ); }
                        /// Wrap instantiation lookup for unions
                        UnionDecl* lookup( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (UnionDecl*)instantiations.lookup( inst->get_baseUnion(), typeSubs ); }
                        /// Wrap instantiation insertion for structs
                        void insert( StructInstType *inst, const std::list< TypeExpr* > &typeSubs, StructDecl *decl ) { instantiations.insert( inst->get_baseStruct(), typeSubs, decl ); }
                        /// Wrap instantiation insertion for unions
                        void insert( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs, UnionDecl *decl ) { instantiations.insert( inst->get_baseUnion(), typeSubs, decl ); }
                };

                /// Replaces member expressions for polymorphic types with calculated add-field-offset-and-dereference;
                /// also fixes offsetof expressions.
                class MemberExprFixer : public PolyMutator {
                  public:
                        template< typename DeclClass >
                        DeclClass *handleDecl( DeclClass *decl, Type *type );
                        virtual DeclarationWithType *mutate( FunctionDecl *functionDecl );
                        virtual ObjectDecl *mutate( ObjectDecl *objectDecl );
                        virtual TypedefDecl *mutate( TypedefDecl *objectDecl );
                        virtual TypeDecl *mutate( TypeDecl *objectDecl );
                        virtual Statement *mutate( DeclStmt *declStmt );
                        virtual Type *mutate( PointerType *pointerType );
                        virtual Type *mutate( FunctionType *funcType );
                        virtual Expression *mutate( MemberExpr *memberExpr );
                        virtual Expression *mutate( OffsetofExpr *offsetofExpr );
                };

                /// Replaces initialization of polymorphic values with alloca, declaration of dtype/ftype with appropriate void expression, and sizeof expressions of polymorphic types with the proper variable
                class Pass3 : public PolyMutator {
                  public:
                        template< typename DeclClass >
                        DeclClass *handleDecl( DeclClass *decl, Type *type );
                        virtual DeclarationWithType *mutate( FunctionDecl *functionDecl );
                        virtual ObjectDecl *mutate( ObjectDecl *objectDecl );
                        virtual TypedefDecl *mutate( TypedefDecl *objectDecl );
                        virtual TypeDecl *mutate( TypeDecl *objectDecl );
                        virtual Type *mutate( PointerType *pointerType );
                        virtual Type *mutate( FunctionType *funcType );
                  private:
                };

        } // anonymous namespace

        /// version of mutateAll with special handling for translation unit so you can check the end of the prelude when debugging
        template< typename MutatorType >
        inline void mutateTranslationUnit( std::list< Declaration* > &translationUnit, MutatorType &mutator ) {
                bool seenIntrinsic = false;
                SemanticError errors;
                for ( typename std::list< Declaration* >::iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
                        try {
                                if ( *i ) {
                                        if ( (*i)->get_linkage() == LinkageSpec::Intrinsic ) {
                                                seenIntrinsic = true;
                                        } else if ( seenIntrinsic ) {
                                                seenIntrinsic = false; // break on this line when debugging for end of prelude
                                        }

                                        *i = dynamic_cast< Declaration* >( (*i)->acceptMutator( mutator ) );
                                        assert( *i );
                                } // if
                        } catch( SemanticError &e ) {
                                errors.append( e );
                        } // try
                } // for
                if ( ! errors.isEmpty() ) {
                        throw errors;
                } // if
        }

        void box( std::list< Declaration *>& translationUnit ) {
                LayoutFunctionBuilder layoutBuilder;
                Pass1 pass1;
                Pass2 pass2;
                GenericInstantiator instantiator;
                MemberExprFixer memberFixer;
                Pass3 pass3;
                
                layoutBuilder.mutateDeclarationList( translationUnit );
                mutateTranslationUnit/*All*/( translationUnit, pass1 );
                mutateTranslationUnit/*All*/( translationUnit, pass2 );
                instantiator.mutateDeclarationList( translationUnit );
                mutateTranslationUnit/*All*/( translationUnit, memberFixer );
                mutateTranslationUnit/*All*/( translationUnit, pass3 );
        }

        ////////////////////////////////// LayoutFunctionBuilder ////////////////////////////////////////////

        DeclarationWithType *LayoutFunctionBuilder::mutate( FunctionDecl *functionDecl ) {
                functionDecl->set_functionType( maybeMutate( functionDecl->get_functionType(), *this ) );
                mutateAll( functionDecl->get_oldDecls(), *this );
                ++functionNesting;
                functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
                --functionNesting;
                return functionDecl;
        }
        
        /// Get a list of type declarations that will affect a layout function
        std::list< TypeDecl* > takeOtypeOnly( std::list< TypeDecl* > &decls ) {
                std::list< TypeDecl * > otypeDecls;

                for ( std::list< TypeDecl* >::const_iterator decl = decls.begin(); decl != decls.end(); ++decl ) {
                        if ( (*decl)->get_kind() == TypeDecl::Any ) {
                                otypeDecls.push_back( *decl );
                        }
                }
                
                return otypeDecls;
        }

        /// Adds parameters for otype layout to a function type
        void addOtypeParams( FunctionType *layoutFnType, std::list< TypeDecl* > &otypeParams ) {
                BasicType sizeAlignType( Type::Qualifiers(), BasicType::LongUnsignedInt );
                
                for ( std::list< TypeDecl* >::const_iterator param = otypeParams.begin(); param != otypeParams.end(); ++param ) {
                        TypeInstType paramType( Type::Qualifiers(), (*param)->get_name(), *param );
                        layoutFnType->get_parameters().push_back( new ObjectDecl( sizeofName( &paramType ), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignType.clone(), 0 ) );
                        layoutFnType->get_parameters().push_back( new ObjectDecl( alignofName( &paramType ), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignType.clone(), 0 ) );
                }
        }

        /// Builds a layout function declaration
        FunctionDecl *buildLayoutFunctionDecl( const std::string &typeName, unsigned int functionNesting, FunctionType *layoutFnType ) {
                // Routines at global scope marked "static" to prevent multiple definitions is separate translation units
                // because each unit generates copies of the default routines for each aggregate.
                FunctionDecl *layoutDecl = new FunctionDecl(
                        "__layoutof_" + typeName, functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, layoutFnType, new CompoundStmt( noLabels ), true, false );
                layoutDecl->fixUniqueId();
                return layoutDecl;
        }

        /// Makes a unary operation
        Expression *makeOp( const std::string &name, Expression *arg ) {
                UntypedExpr *expr = new UntypedExpr( new NameExpr( name ) );
                expr->get_args().push_back( arg );
                return expr;
        }

        /// Makes a binary operation
        Expression *makeOp( const std::string &name, Expression *lhs, Expression *rhs ) {
                UntypedExpr *expr = new UntypedExpr( new NameExpr( name ) );
                expr->get_args().push_back( lhs );
                expr->get_args().push_back( rhs );
                return expr;
        }

        /// Returns the dereference of a local pointer variable
        Expression *derefVar( ObjectDecl *var ) {
                return makeOp( "*?", new VariableExpr( var ) );
        }

        /// makes an if-statement with a single-expression if-block and no then block
        Statement *makeCond( Expression *cond, Expression *ifPart ) {
                return new IfStmt( noLabels, cond, new ExprStmt( noLabels, ifPart ), 0 );
        }

        /// makes a statement that assigns rhs to lhs if lhs < rhs
        Statement *makeAssignMax( Expression *lhs, Expression *rhs ) {
                return makeCond( makeOp( "?<?", lhs, rhs ), makeOp( "?=?", lhs->clone(), rhs->clone() ) );
        }

        /// makes a statement that aligns lhs to rhs (rhs should be an integer power of two)
        Statement *makeAlignTo( Expression *lhs, Expression *rhs ) {
                // check that the lhs is zeroed out to the level of rhs
                Expression *ifCond = makeOp( "?&?", lhs, makeOp( "?-?", rhs, new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), "1" ) ) ) );
                // if not aligned, increment to alignment
                Expression *ifExpr = makeOp( "?+=?", lhs->clone(), makeOp( "?-?", rhs->clone(), ifCond->clone() ) );
                return makeCond( ifCond, ifExpr );
        }
        
        /// adds an expression to a compound statement
        void addExpr( CompoundStmt *stmts, Expression *expr ) {
                stmts->get_kids().push_back( new ExprStmt( noLabels, expr ) );
        }

        /// adds a statement to a compound statement
        void addStmt( CompoundStmt *stmts, Statement *stmt ) {
                stmts->get_kids().push_back( stmt );
        }
        
        Declaration *LayoutFunctionBuilder::mutate( StructDecl *structDecl ) {
                // do not generate layout function for "empty" tag structs
                if ( structDecl->get_members().empty() ) return structDecl;

                // get parameters that can change layout, exiting early if none
                std::list< TypeDecl* > otypeParams = takeOtypeOnly( structDecl->get_parameters() );
                if ( otypeParams.empty() ) return structDecl;

                // build layout function signature
                FunctionType *layoutFnType = new FunctionType( Type::Qualifiers(), false );
                BasicType *sizeAlignType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );
                PointerType *sizeAlignOutType = new PointerType( Type::Qualifiers(), sizeAlignType );
                
                ObjectDecl *sizeParam = new ObjectDecl( "__sizeof_" + structDecl->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignOutType, 0 );
                layoutFnType->get_parameters().push_back( sizeParam );
                ObjectDecl *alignParam = new ObjectDecl( "__alignof_" + structDecl->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignOutType->clone(), 0 );
                layoutFnType->get_parameters().push_back( alignParam );
                ObjectDecl *offsetParam = new ObjectDecl( "__offsetof_" + structDecl->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignOutType->clone(), 0 );
                layoutFnType->get_parameters().push_back( offsetParam );
                addOtypeParams( layoutFnType, otypeParams );

                // build function decl
                FunctionDecl *layoutDecl = buildLayoutFunctionDecl( structDecl->get_name(), functionNesting, layoutFnType );

                // calculate struct layout in function body

                // initialize size and alignment to 0 and 1 (will have at least one member to re-edit size
                addExpr( layoutDecl->get_statements(), makeOp( "?=?", derefVar( sizeParam ), new ConstantExpr( Constant( sizeAlignType->clone(), "0" ) ) ) );
                addExpr( layoutDecl->get_statements(), makeOp( "?=?", derefVar( alignParam ), new ConstantExpr( Constant( sizeAlignType->clone(), "1" ) ) ) );
                unsigned long n_members = 0;
                bool firstMember = true;
                for ( std::list< Declaration* >::const_iterator member = structDecl->get_members().begin(); member != structDecl->get_members().end(); ++member ) {
                        DeclarationWithType *dwt = dynamic_cast< DeclarationWithType * >( *member );
                        assert( dwt );
                        Type *memberType = dwt->get_type();

                        if ( firstMember ) {
                                firstMember = false;
                        } else {
                                // make sure all members after the first (automatically aligned at 0) are properly padded for alignment
                                addStmt( layoutDecl->get_statements(), makeAlignTo( derefVar( sizeParam ), new AlignofExpr( memberType->clone() ) ) );
                        }
                        
                        // place current size in the current offset index
                        addExpr( layoutDecl->get_statements(), makeOp( "?=?", makeOp( "?[?]", new VariableExpr( offsetParam ), new ConstantExpr( Constant::from( n_members ) ) ),
                                                                              derefVar( sizeParam ) ) );
                        ++n_members;

                        // add member size to current size
                        addExpr( layoutDecl->get_statements(), makeOp( "?+=?", derefVar( sizeParam ), new SizeofExpr( memberType->clone() ) ) );
                        
                        // take max of member alignment and global alignment
                        addStmt( layoutDecl->get_statements(), makeAssignMax( derefVar( alignParam ), new AlignofExpr( memberType->clone() ) ) );
                }
                // make sure the type is end-padded to a multiple of its alignment
                addStmt( layoutDecl->get_statements(), makeAlignTo( derefVar( sizeParam ), derefVar( alignParam ) ) );

                addDeclarationAfter( layoutDecl );
                return structDecl;
        }
        
        Declaration *LayoutFunctionBuilder::mutate( UnionDecl *unionDecl ) {
                // do not generate layout function for "empty" tag unions
                if ( unionDecl->get_members().empty() ) return unionDecl;
                
                // get parameters that can change layout, exiting early if none
                std::list< TypeDecl* > otypeParams = takeOtypeOnly( unionDecl->get_parameters() );
                if ( otypeParams.empty() ) return unionDecl;

                // build layout function signature
                FunctionType *layoutFnType = new FunctionType( Type::Qualifiers(), false );
                BasicType *sizeAlignType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );
                PointerType *sizeAlignOutType = new PointerType( Type::Qualifiers(), sizeAlignType );
                
                ObjectDecl *sizeParam = new ObjectDecl( "__sizeof_" + unionDecl->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignOutType, 0 );
                layoutFnType->get_parameters().push_back( sizeParam );
                ObjectDecl *alignParam = new ObjectDecl( "__alignof_" + unionDecl->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, sizeAlignOutType->clone(), 0 );
                layoutFnType->get_parameters().push_back( alignParam );
                addOtypeParams( layoutFnType, otypeParams );

                // build function decl
                FunctionDecl *layoutDecl = buildLayoutFunctionDecl( unionDecl->get_name(), functionNesting, layoutFnType );

                // calculate union layout in function body
                addExpr( layoutDecl->get_statements(), makeOp( "?=?", derefVar( sizeParam ), new ConstantExpr( Constant( sizeAlignType->clone(), "1" ) ) ) );
                addExpr( layoutDecl->get_statements(), makeOp( "?=?", derefVar( alignParam ), new ConstantExpr( Constant( sizeAlignType->clone(), "1" ) ) ) );
                for ( std::list< Declaration* >::const_iterator member = unionDecl->get_members().begin(); member != unionDecl->get_members().end(); ++member ) {
                        DeclarationWithType *dwt = dynamic_cast< DeclarationWithType * >( *member );
                        assert( dwt );
                        Type *memberType = dwt->get_type();
                        
                        // take max member size and global size
                        addStmt( layoutDecl->get_statements(), makeAssignMax( derefVar( sizeParam ), new SizeofExpr( memberType->clone() ) ) );
                        
                        // take max of member alignment and global alignment
                        addStmt( layoutDecl->get_statements(), makeAssignMax( derefVar( alignParam ), new AlignofExpr( memberType->clone() ) ) );
                }
                // make sure the type is end-padded to a multiple of its alignment
                addStmt( layoutDecl->get_statements(), makeAlignTo( derefVar( sizeParam ), derefVar( alignParam ) ) );

                addDeclarationAfter( layoutDecl );
                return unionDecl;
        }
        
        ////////////////////////////////////////// Pass1 ////////////////////////////////////////////////////

        namespace {
                std::string makePolyMonoSuffix( FunctionType * function, const TyVarMap &tyVars ) {
                        std::stringstream name;

                        // NOTE: this function previously used isPolyObj, which failed to produce
                        // the correct thing in some situations. It's not clear to me why this wasn't working.

                        // if the return type or a parameter type involved polymorphic types, then the adapter will need
                        // to take those polymorphic types as pointers. Therefore, there can be two different functions
                        // with the same mangled name, so we need to further mangle the names.
                        for ( std::list< DeclarationWithType *>::iterator retval = function->get_returnVals().begin(); retval != function->get_returnVals().end(); ++retval ) {
                                if ( isPolyType( (*retval)->get_type(), tyVars ) ) {
                                        name << "P";
                                } else {
                                        name << "M";
                                }
                        }
                        name << "_";
                        std::list< DeclarationWithType *> &paramList = function->get_parameters();
                        for ( std::list< DeclarationWithType *>::iterator arg = paramList.begin(); arg != paramList.end(); ++arg ) {
                                if ( isPolyType( (*arg)->get_type(), tyVars ) ) {
                                        name << "P";
                                } else {
                                        name << "M";
                                }
                        } // for
                        return name.str();
                }

                std::string mangleAdapterName( FunctionType * function, const TyVarMap &tyVars ) {
                        return SymTab::Mangler::mangle( function ) + makePolyMonoSuffix( function, tyVars );
                }

                std::string makeAdapterName( const std::string &mangleName ) {
                        return "_adapter" + mangleName;
                }

                Pass1::Pass1() : useRetval( false ), tempNamer( "_temp" ) {}

                /// Returns T if the given declaration is (*?=?)(T *, T) for some TypeInstType T (return not checked, but maybe should be), NULL otherwise
                TypeInstType *isTypeInstAssignment( DeclarationWithType *decl ) {
                        if ( decl->get_name() == "?=?" ) {
                                if ( FunctionType *funType = getFunctionType( decl->get_type() ) ) {
                                        if ( funType->get_parameters().size() == 2 ) {
                                                if ( PointerType *pointer = dynamic_cast< PointerType *>( funType->get_parameters().front()->get_type() ) ) {
                                                        if ( TypeInstType *refType = dynamic_cast< TypeInstType *>( pointer->get_base() ) ) {
                                                                if ( TypeInstType *refType2 = dynamic_cast< TypeInstType *>( funType->get_parameters().back()->get_type() ) ) {
                                                                        if ( refType->get_name() == refType2->get_name() ) {
                                                                                return refType;
                                                                        } // if
                                                                } // if
                                                        } // if
                                                } // if
                                        } // if
                                } // if
                        } // if
                        return 0;
                }
                
                /// returns T if the given declaration is: (*?=?)(T *, T) for some type T (return not checked, but maybe should be), NULL otherwise
                /// Only picks assignments where neither parameter is cv-qualified
                Type *isAssignment( DeclarationWithType *decl ) {
                        if ( decl->get_name() == "?=?" ) {
                                if ( FunctionType *funType = getFunctionType( decl->get_type() ) ) {
                                        if ( funType->get_parameters().size() == 2 ) {
                                                Type::Qualifiers defaultQualifiers;
                                                Type *paramType1 = funType->get_parameters().front()->get_type();
                                                if ( paramType1->get_qualifiers() != defaultQualifiers ) return 0;
                                                Type *paramType2 = funType->get_parameters().back()->get_type();
                                                if ( paramType2->get_qualifiers() != defaultQualifiers ) return 0;
                                                
                                                if ( PointerType *pointerType = dynamic_cast< PointerType* >( paramType1 ) ) {
                                                        Type *baseType1 = pointerType->get_base();
                                                        if ( baseType1->get_qualifiers() != defaultQualifiers ) return 0;
                                                        SymTab::Indexer dummy;
                                                        if ( ResolvExpr::typesCompatible( baseType1, paramType2, dummy ) ) {
                                                                return baseType1;
                                                        } // if
                                                } // if
                                        } // if
                                } // if
                        } // if
                        return 0;
                }

                void Pass1::findAssignOps( const std::list< TypeDecl *> &forall ) {
                        // what if a nested function uses an assignment operator?
                        // assignOps.clear();
                        for ( std::list< TypeDecl *>::const_iterator i = forall.begin(); i != forall.end(); ++i ) {
                                for ( std::list< DeclarationWithType *>::const_iterator assert = (*i)->get_assertions().begin(); assert != (*i)->get_assertions().end(); ++assert ) {
                                        std::string typeName;
                                        if ( TypeInstType *typeInst = isTypeInstAssignment( *assert ) ) {
                                                assignOps[ typeInst->get_name() ] = *assert;
                                        } // if
                                } // for
                        } // for
                }

                DeclarationWithType *Pass1::mutate( FunctionDecl *functionDecl ) {
                        // if this is a assignment function, put it in the map for this scope
                        if ( Type *assignedType = isAssignment( functionDecl ) ) {
                                if ( ! dynamic_cast< TypeInstType* >( assignedType ) ) {
                                        scopedAssignOps.insert( assignedType, functionDecl );
                                }
                        }

                        if ( functionDecl->get_statements() ) {         // empty routine body ?
                                doBeginScope();
                                TyVarMap oldtyVars = scopeTyVars;
                                std::map< std::string, DeclarationWithType *> oldassignOps = assignOps;
                                DeclarationWithType *oldRetval = retval;
                                bool oldUseRetval = useRetval;

                                // process polymorphic return value
                                retval = 0;
                                if ( isPolyRet( functionDecl->get_functionType() ) && functionDecl->get_linkage() == LinkageSpec::Cforall ) {
                                        retval = functionDecl->get_functionType()->get_returnVals().front();

                                        // give names to unnamed return values
                                        if ( retval->get_name() == "" ) {
                                                retval->set_name( "_retparm" );
                                                retval->set_linkage( LinkageSpec::C );
                                        } // if
                                } // if

                                FunctionType *functionType = functionDecl->get_functionType();
                                makeTyVarMap( functionDecl->get_functionType(), scopeTyVars );
                                findAssignOps( functionDecl->get_functionType()->get_forall() );

                                std::list< DeclarationWithType *> &paramList = functionType->get_parameters();
                                std::list< FunctionType *> functions;
                                for ( std::list< TypeDecl *>::iterator tyVar = functionType->get_forall().begin(); tyVar != functionType->get_forall().end(); ++tyVar ) {
                                        for ( std::list< DeclarationWithType *>::iterator assert = (*tyVar)->get_assertions().begin(); assert != (*tyVar)->get_assertions().end(); ++assert ) {
                                                findFunction( (*assert)->get_type(), functions, scopeTyVars, needsAdapter );
                                        } // for
                                } // for
                                for ( std::list< DeclarationWithType *>::iterator arg = paramList.begin(); arg != paramList.end(); ++arg ) {
                                        findFunction( (*arg)->get_type(), functions, scopeTyVars, needsAdapter );
                                } // for

                                for ( std::list< FunctionType *>::iterator funType = functions.begin(); funType != functions.end(); ++funType ) {
                                        std::string mangleName = mangleAdapterName( *funType, scopeTyVars );
                                        if ( adapters.find( mangleName ) == adapters.end() ) {
                                                std::string adapterName = makeAdapterName( mangleName );
                                                adapters.insert( std::pair< std::string, DeclarationWithType *>( mangleName, new ObjectDecl( adapterName, DeclarationNode::NoStorageClass, LinkageSpec::C, 0, new PointerType( Type::Qualifiers(), makeAdapterType( *funType, scopeTyVars ) ), 0 ) ) );
                                        } // if
                                } // for

                                functionDecl->set_statements( functionDecl->get_statements()->acceptMutator( *this ) );

                                scopeTyVars = oldtyVars;
                                assignOps = oldassignOps;
                                // std::cerr << "end FunctionDecl: ";
                                // for ( TyVarMap::iterator i = scopeTyVars.begin(); i != scopeTyVars.end(); ++i ) {
                                //      std::cerr << i->first << " ";
                                // }
                                // std::cerr << "\n";
                                retval = oldRetval;
                                useRetval = oldUseRetval;
                                doEndScope();
                        } // if
                        return functionDecl;
                }

                TypeDecl *Pass1::mutate( TypeDecl *typeDecl ) {
                        scopeTyVars[ typeDecl->get_name() ] = typeDecl->get_kind();
                        return Mutator::mutate( typeDecl );
                }

                Expression *Pass1::mutate( CommaExpr *commaExpr ) {
                        bool oldUseRetval = useRetval;
                        useRetval = false;
                        commaExpr->set_arg1( maybeMutate( commaExpr->get_arg1(), *this ) );
                        useRetval = oldUseRetval;
                        commaExpr->set_arg2( maybeMutate( commaExpr->get_arg2(), *this ) );
                        return commaExpr;
                }

                Expression *Pass1::mutate( ConditionalExpr *condExpr ) {
                        bool oldUseRetval = useRetval;
                        useRetval = false;
                        condExpr->set_arg1( maybeMutate( condExpr->get_arg1(), *this ) );
                        useRetval = oldUseRetval;
                        condExpr->set_arg2( maybeMutate( condExpr->get_arg2(), *this ) );
                        condExpr->set_arg3( maybeMutate( condExpr->get_arg3(), *this ) );
                        return condExpr;

                }

                void Pass1::passArgTypeVars( ApplicationExpr *appExpr, Type *parmType, Type *argBaseType, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars, std::set< std::string > &seenTypes ) {
                        Type *polyBase = hasPolyBase( parmType, exprTyVars );
                        if ( polyBase && ! dynamic_cast< TypeInstType* >( polyBase ) ) {
                                std::string sizeName = sizeofName( polyBase );
                                if ( seenTypes.count( sizeName ) ) return;

                                arg = appExpr->get_args().insert( arg, new SizeofExpr( argBaseType->clone() ) );
                                arg++;
                                arg = appExpr->get_args().insert( arg, new AlignofExpr( argBaseType->clone() ) );
                                arg++;
                                if ( dynamic_cast< StructInstType* >( polyBase ) ) {
                                        if ( StructInstType *argBaseStructType = dynamic_cast< StructInstType* >( argBaseType ) ) {
                                                // zero-length arrays are forbidden by C, so don't pass offset for empty struct
                                                if ( ! argBaseStructType->get_baseStruct()->get_members().empty() ) {
                                                        arg = appExpr->get_args().insert( arg, new OffsetPackExpr( argBaseStructType->clone() ) );
                                                        arg++;
                                                }
                                        } else {
                                                throw SemanticError( "Cannot pass non-struct type for generic struct" );
                                        }
                                }

                                seenTypes.insert( sizeName );
                        }
                }

                void Pass1::passTypeVars( ApplicationExpr *appExpr, ReferenceToType *polyRetType, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars ) {
                        // pass size/align for type variables
                        for ( TyVarMap::const_iterator tyParm = exprTyVars.begin(); tyParm != exprTyVars.end(); ++tyParm ) {
                                ResolvExpr::EqvClass eqvClass;
                                assert( env );
                                if ( tyParm->second == TypeDecl::Any ) {
                                        Type *concrete = env->lookup( tyParm->first );
                                        if ( concrete ) {
                                                arg = appExpr->get_args().insert( arg, new SizeofExpr( concrete->clone() ) );
                                                arg++;
                                                arg = appExpr->get_args().insert( arg, new AlignofExpr( concrete->clone() ) );
                                                arg++;
                                        } else {
                                                throw SemanticError( "unbound type variable in application ", appExpr );
                                        } // if
                                } // if
                        } // for

                        // add size/align for generic types to parameter list
                        if ( appExpr->get_function()->get_results().empty() ) return;
                        FunctionType *funcType = getFunctionType( appExpr->get_function()->get_results().front() );
                        assert( funcType );

                        std::list< DeclarationWithType* >::const_iterator fnParm = funcType->get_parameters().begin();
                        std::list< Expression* >::const_iterator fnArg = arg;
                        std::set< std::string > seenTypes; //< names for generic types we've seen

                        // a polymorphic return type may need to be added to the argument list
                        if ( polyRetType ) {
                                Type *concRetType = replaceWithConcrete( appExpr, polyRetType );
                                passArgTypeVars( appExpr, polyRetType, concRetType, arg, exprTyVars, seenTypes );
                        }
                        
                        // add type information args for presently unseen types in parameter list
                        for ( ; fnParm != funcType->get_parameters().end() && fnArg != appExpr->get_args().end(); ++fnParm, ++fnArg ) {
                                VariableExpr *fnArgBase = getBaseVar( *fnArg );
                                if ( ! fnArgBase || fnArgBase->get_results().empty() ) continue;
                                passArgTypeVars( appExpr, (*fnParm)->get_type(), fnArgBase->get_results().front(), arg, exprTyVars, seenTypes );
                        }
                }

                ObjectDecl *Pass1::makeTemporary( Type *type ) {
                        ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, type, 0 );
                        stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
                        return newObj;
                }

                Expression *Pass1::addRetParam( ApplicationExpr *appExpr, FunctionType *function, Type *retType, std::list< Expression *>::iterator &arg ) {
                        // ***** Code Removal ***** After introducing a temporary variable for all return expressions, the following code appears superfluous.
                        // if ( useRetval ) {
                        //      assert( retval );
                        //      arg = appExpr->get_args().insert( arg, new VariableExpr( retval ) );
                        //      arg++;
                        // } else {

                        // Create temporary to hold return value of polymorphic function and produce that temporary as a result
                        // using a comma expression.  Possibly change comma expression into statement expression "{}" for multiple
                        // return values.
                        ObjectDecl *newObj = makeTemporary( retType->clone() );
                        Expression *paramExpr = new VariableExpr( newObj );

                        // If the type of the temporary is not polymorphic, box temporary by taking its address;
                        // otherwise the temporary is already boxed and can be used directly.
                        if ( ! isPolyType( newObj->get_type(), scopeTyVars, env ) ) {
                                paramExpr = new AddressExpr( paramExpr );
                        } // if
                        arg = appExpr->get_args().insert( arg, paramExpr ); // add argument to function call
                        arg++;
                        // Build a comma expression to call the function and emulate a normal return.
                        CommaExpr *commaExpr = new CommaExpr( appExpr, new VariableExpr( newObj ) );
                        commaExpr->set_env( appExpr->get_env() );
                        appExpr->set_env( 0 );
                        return commaExpr;
                        // } // if
                        // return appExpr;
                }

                void Pass1::replaceParametersWithConcrete( ApplicationExpr *appExpr, std::list< Expression* >& params ) {
                        for ( std::list< Expression* >::iterator param = params.begin(); param != params.end(); ++param ) {
                                TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
                                assert(paramType && "Aggregate parameters should be type expressions");
                                paramType->set_type( replaceWithConcrete( appExpr, paramType->get_type(), false ) );
                        }
                }

                Type *Pass1::replaceWithConcrete( ApplicationExpr *appExpr, Type *type, bool doClone ) {
                        if ( TypeInstType *typeInst = dynamic_cast< TypeInstType * >( type ) ) {
                                Type *concrete = env->lookup( typeInst->get_name() );
                                if ( concrete == 0 ) {
                                        throw SemanticError( "Unbound type variable " + typeInst->get_name() + " in ", appExpr );
                                } // if
                                return concrete;
                        } else if ( StructInstType *structType = dynamic_cast< StructInstType* >( type ) ) {
                                if ( doClone ) {
                                        structType = structType->clone();
                                }
                                replaceParametersWithConcrete( appExpr, structType->get_parameters() );
                                return structType;
                        } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( type ) ) {
                                if ( doClone ) {
                                        unionType = unionType->clone();
                                }
                                replaceParametersWithConcrete( appExpr, unionType->get_parameters() );
                                return unionType;
                        }
                        return type;
                }

                Expression *Pass1::addPolyRetParam( ApplicationExpr *appExpr, FunctionType *function, ReferenceToType *polyType, std::list< Expression *>::iterator &arg ) {
                        assert( env );
                        Type *concrete = replaceWithConcrete( appExpr, polyType );
                        // add out-parameter for return value   
                        return addRetParam( appExpr, function, concrete, arg );
                }

                Expression *Pass1::applyAdapter( ApplicationExpr *appExpr, FunctionType *function, std::list< Expression *>::iterator &arg, const TyVarMap &tyVars ) {
                        Expression *ret = appExpr;
                        if ( ! function->get_returnVals().empty() && isPolyType( function->get_returnVals().front()->get_type(), tyVars ) ) {
                                ret = addRetParam( appExpr, function, function->get_returnVals().front()->get_type(), arg );
                        } // if
                        std::string mangleName = mangleAdapterName( function, tyVars );
                        std::string adapterName = makeAdapterName( mangleName );

                        // cast adaptee to void (*)(), since it may have any type inside a polymorphic function
                        Type * adapteeType = new PointerType( Type::Qualifiers(), new FunctionType( Type::Qualifiers(), true ) );
                        appExpr->get_args().push_front( new CastExpr( appExpr->get_function(), adapteeType ) );
                        appExpr->set_function( new NameExpr( adapterName ) );

                        return ret;
                }

                void Pass1::boxParam( Type *param, Expression *&arg, const TyVarMap &exprTyVars ) {
                        assert( ! arg->get_results().empty() );
                        if ( isPolyType( param, exprTyVars ) ) {
                                if ( isPolyType( arg->get_results().front() ) ) {
                                        // if the argument's type is polymorphic, we don't need to box again!
                                        return;
                                } else if ( arg->get_results().front()->get_isLvalue() ) {
                                        // VariableExpr and MemberExpr are lvalues
                                        arg = new AddressExpr( arg );
                                } else {
                                        // use type computed in unification to declare boxed variables
                                        Type * newType = param->clone();
                                        if ( env ) env->apply( newType );
                                        ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, newType, 0 );
                                        newObj->get_type()->get_qualifiers() = Type::Qualifiers(); // TODO: is this right???
                                        stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
                                        UntypedExpr *assign = new UntypedExpr( new NameExpr( "?=?" ) );
                                        assign->get_args().push_back( new VariableExpr( newObj ) );
                                        assign->get_args().push_back( arg );
                                        stmtsToAdd.push_back( new ExprStmt( noLabels, assign ) );
                                        arg = new AddressExpr( new VariableExpr( newObj ) );
                                } // if
                        } // if
                }

                /// cast parameters to polymorphic functions so that types are replaced with
                /// void * if they are type parameters in the formal type.
                /// this gets rid of warnings from gcc.
                void addCast( Expression *&actual, Type *formal, const TyVarMap &tyVars ) {
                        Type * newType = formal->clone();
                        if ( getFunctionType( newType ) ) {
                                newType = ScrubTyVars::scrub( newType, tyVars );
                                actual = new CastExpr( actual, newType );
                        } // if
                }

                void Pass1::boxParams( ApplicationExpr *appExpr, FunctionType *function, std::list< Expression *>::iterator &arg, const TyVarMap &exprTyVars ) {
                        for ( std::list< DeclarationWithType *>::const_iterator param = function->get_parameters().begin(); param != function->get_parameters().end(); ++param, ++arg ) {
                                assert( arg != appExpr->get_args().end() );
                                addCast( *arg, (*param)->get_type(), exprTyVars );
                                boxParam( (*param)->get_type(), *arg, exprTyVars );
                        } // for
                }

                void Pass1::addInferredParams( ApplicationExpr *appExpr, FunctionType *functionType, std::list< Expression *>::iterator &arg, const TyVarMap &tyVars ) {
                        std::list< Expression *>::iterator cur = arg;
                        for ( std::list< TypeDecl *>::iterator tyVar = functionType->get_forall().begin(); tyVar != functionType->get_forall().end(); ++tyVar ) {
                                for ( std::list< DeclarationWithType *>::iterator assert = (*tyVar)->get_assertions().begin(); assert != (*tyVar)->get_assertions().end(); ++assert ) {
                                        InferredParams::const_iterator inferParam = appExpr->get_inferParams().find( (*assert)->get_uniqueId() );
                                        assert( inferParam != appExpr->get_inferParams().end() && "NOTE: Explicit casts of polymorphic functions to compatible monomorphic functions are currently unsupported" );
                                        Expression *newExpr = inferParam->second.expr->clone();
                                        addCast( newExpr, (*assert)->get_type(), tyVars );
                                        boxParam( (*assert)->get_type(), newExpr, tyVars );
                                        appExpr->get_args().insert( cur, newExpr );
                                } // for
                        } // for
                }

                void makeRetParm( FunctionType *funcType ) {
                        DeclarationWithType *retParm = funcType->get_returnVals().front();

                        // make a new parameter that is a pointer to the type of the old return value
                        retParm->set_type( new PointerType( Type::Qualifiers(), retParm->get_type() ) );
                        funcType->get_parameters().push_front( retParm );

                        // we don't need the return value any more
                        funcType->get_returnVals().clear();
                }

                FunctionType *makeAdapterType( FunctionType *adaptee, const TyVarMap &tyVars ) {
                        // actually make the adapter type
                        FunctionType *adapter = adaptee->clone();
                        if ( ! adapter->get_returnVals().empty() && isPolyType( adapter->get_returnVals().front()->get_type(), tyVars ) ) {
                                makeRetParm( adapter );
                        } // if
                        adapter->get_parameters().push_front( new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::C, 0, new PointerType( Type::Qualifiers(), new FunctionType( Type::Qualifiers(), true ) ), 0 ) );
                        return adapter;
                }

                Expression *makeAdapterArg( DeclarationWithType *param, DeclarationWithType *arg, DeclarationWithType *realParam, const TyVarMap &tyVars ) {
                        assert( param );
                        assert( arg );
                        if ( isPolyType( realParam->get_type(), tyVars ) ) {
                                if ( ! isPolyType( arg->get_type() ) ) {
                                        UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) );
                                        deref->get_args().push_back( new CastExpr( new VariableExpr( param ), new PointerType( Type::Qualifiers(), arg->get_type()->clone() ) ) );
                                        deref->get_results().push_back( arg->get_type()->clone() );
                                        return deref;
                                } // if
                        } // if
                        return new VariableExpr( param );
                }

                void addAdapterParams( ApplicationExpr *adapteeApp, std::list< DeclarationWithType *>::iterator arg, std::list< DeclarationWithType *>::iterator param, std::list< DeclarationWithType *>::iterator paramEnd, std::list< DeclarationWithType *>::iterator realParam, const TyVarMap &tyVars ) {
                        UniqueName paramNamer( "_p" );
                        for ( ; param != paramEnd; ++param, ++arg, ++realParam ) {
                                if ( (*param)->get_name() == "" ) {
                                        (*param)->set_name( paramNamer.newName() );
                                        (*param)->set_linkage( LinkageSpec::C );
                                } // if
                                adapteeApp->get_args().push_back( makeAdapterArg( *param, *arg, *realParam, tyVars ) );
                        } // for
                }



                FunctionDecl *Pass1::makeAdapter( FunctionType *adaptee, FunctionType *realType, const std::string &mangleName, const TyVarMap &tyVars ) {
                        FunctionType *adapterType = makeAdapterType( adaptee, tyVars );
                        adapterType = ScrubTyVars::scrub( adapterType, tyVars );
                        DeclarationWithType *adapteeDecl = adapterType->get_parameters().front();
                        adapteeDecl->set_name( "_adaptee" );
                        ApplicationExpr *adapteeApp = new ApplicationExpr( new CastExpr( new VariableExpr( adapteeDecl ), new PointerType( Type::Qualifiers(), realType ) ) );
                        Statement *bodyStmt;

                        std::list< TypeDecl *>::iterator tyArg = realType->get_forall().begin();
                        std::list< TypeDecl *>::iterator tyParam = adapterType->get_forall().begin();
                        std::list< TypeDecl *>::iterator realTyParam = adaptee->get_forall().begin();
                        for ( ; tyParam != adapterType->get_forall().end(); ++tyArg, ++tyParam, ++realTyParam ) {
                                assert( tyArg != realType->get_forall().end() );
                                std::list< DeclarationWithType *>::iterator assertArg = (*tyArg)->get_assertions().begin();
                                std::list< DeclarationWithType *>::iterator assertParam = (*tyParam)->get_assertions().begin();
                                std::list< DeclarationWithType *>::iterator realAssertParam = (*realTyParam)->get_assertions().begin();
                                for ( ; assertParam != (*tyParam)->get_assertions().end(); ++assertArg, ++assertParam, ++realAssertParam ) {
                                        assert( assertArg != (*tyArg)->get_assertions().end() );
                                        adapteeApp->get_args().push_back( makeAdapterArg( *assertParam, *assertArg, *realAssertParam, tyVars ) );
                                } // for
                        } // for

                        std::list< DeclarationWithType *>::iterator arg = realType->get_parameters().begin();
                        std::list< DeclarationWithType *>::iterator param = adapterType->get_parameters().begin();
                        std::list< DeclarationWithType *>::iterator realParam = adaptee->get_parameters().begin();
                        param++;                // skip adaptee parameter
                        if ( realType->get_returnVals().empty() ) {
                                addAdapterParams( adapteeApp, arg, param, adapterType->get_parameters().end(), realParam, tyVars );
                                bodyStmt = new ExprStmt( noLabels, adapteeApp );
                        } else if ( isPolyType( adaptee->get_returnVals().front()->get_type(), tyVars ) ) {
                                if ( (*param)->get_name() == "" ) {
                                        (*param)->set_name( "_ret" );
                                        (*param)->set_linkage( LinkageSpec::C );
                                } // if
                                UntypedExpr *assign = new UntypedExpr( new NameExpr( "?=?" ) );
                                UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) );
                                deref->get_args().push_back( new CastExpr( new VariableExpr( *param++ ), new PointerType( Type::Qualifiers(), realType->get_returnVals().front()->get_type()->clone() ) ) );
                                assign->get_args().push_back( deref );
                                addAdapterParams( adapteeApp, arg, param, adapterType->get_parameters().end(), realParam, tyVars );
                                assign->get_args().push_back( adapteeApp );
                                bodyStmt = new ExprStmt( noLabels, assign );
                        } else {
                                // adapter for a function that returns a monomorphic value
                                addAdapterParams( adapteeApp, arg, param, adapterType->get_parameters().end(), realParam, tyVars );
                                bodyStmt = new ReturnStmt( noLabels, adapteeApp );
                        } // if
                        CompoundStmt *adapterBody = new CompoundStmt( noLabels );
                        adapterBody->get_kids().push_back( bodyStmt );
                        std::string adapterName = makeAdapterName( mangleName );
                        return new FunctionDecl( adapterName, DeclarationNode::NoStorageClass, LinkageSpec::C, adapterType, adapterBody, false, false );
                }

                void Pass1::passAdapters( ApplicationExpr * appExpr, FunctionType * functionType, const TyVarMap & exprTyVars ) {
                        // collect a list of function types passed as parameters or implicit parameters (assertions)
                        std::list< DeclarationWithType *> &paramList = functionType->get_parameters();
                        std::list< FunctionType *> functions;
                        for ( std::list< TypeDecl *>::iterator tyVar = functionType->get_forall().begin(); tyVar != functionType->get_forall().end(); ++tyVar ) {
                                for ( std::list< DeclarationWithType *>::iterator assert = (*tyVar)->get_assertions().begin(); assert != (*tyVar)->get_assertions().end(); ++assert ) {
                                        findFunction( (*assert)->get_type(), functions, exprTyVars, needsAdapter );
                                } // for
                        } // for
                        for ( std::list< DeclarationWithType *>::iterator arg = paramList.begin(); arg != paramList.end(); ++arg ) {
                                findFunction( (*arg)->get_type(), functions, exprTyVars, needsAdapter );
                        } // for

                        // parameter function types for which an appropriate adapter has been generated.  we cannot use the types
                        // after applying substitutions, since two different parameter types may be unified to the same type
                        std::set< std::string > adaptersDone;

                        for ( std::list< FunctionType *>::iterator funType = functions.begin(); funType != functions.end(); ++funType ) {
                                FunctionType *originalFunction = (*funType)->clone();
                                FunctionType *realFunction = (*funType)->clone();
                                std::string mangleName = SymTab::Mangler::mangle( realFunction );

                                // only attempt to create an adapter or pass one as a parameter if we haven't already done so for this
                                // pre-substitution parameter function type.
                                if ( adaptersDone.find( mangleName ) == adaptersDone.end() ) {
                                        adaptersDone.insert( adaptersDone.begin(), mangleName );

                                        // apply substitution to type variables to figure out what the adapter's type should look like
                                        assert( env );
                                        env->apply( realFunction );
                                        mangleName = SymTab::Mangler::mangle( realFunction );
                                        mangleName += makePolyMonoSuffix( originalFunction, exprTyVars );

                                        typedef ScopedMap< std::string, DeclarationWithType* >::iterator AdapterIter;
                                        AdapterIter adapter = adapters.find( mangleName );
                                        if ( adapter == adapters.end() ) {
                                                // adapter has not been created yet in the current scope, so define it
                                                FunctionDecl *newAdapter = makeAdapter( *funType, realFunction, mangleName, exprTyVars );
                                                std::pair< AdapterIter, bool > answer = adapters.insert( std::pair< std::string, DeclarationWithType *>( mangleName, newAdapter ) );
                                                adapter = answer.first;
                                                stmtsToAdd.push_back( new DeclStmt( noLabels, newAdapter ) );
                                        } // if
                                        assert( adapter != adapters.end() );

                                        // add the appropriate adapter as a parameter
                                        appExpr->get_args().push_front( new VariableExpr( adapter->second ) );
                                } // if
                        } // for
                } // passAdapters

                Expression *makeIncrDecrExpr( ApplicationExpr *appExpr, Type *polyType, bool isIncr ) {
                        NameExpr *opExpr;
                        if ( isIncr ) {
                                opExpr = new NameExpr( "?+=?" );
                        } else {
                                opExpr = new NameExpr( "?-=?" );
                        } // if
                        UntypedExpr *addAssign = new UntypedExpr( opExpr );
                        if ( AddressExpr *address = dynamic_cast< AddressExpr *>( appExpr->get_args().front() ) ) {
                                addAssign->get_args().push_back( address->get_arg() );
                        } else {
                                addAssign->get_args().push_back( appExpr->get_args().front() );
                        } // if
                        addAssign->get_args().push_back( new NameExpr( sizeofName( polyType ) ) );
                        addAssign->get_results().front() = appExpr->get_results().front()->clone();
                        if ( appExpr->get_env() ) {
                                addAssign->set_env( appExpr->get_env() );
                                appExpr->set_env( 0 );
                        } // if
                        appExpr->get_args().clear();
                        delete appExpr;
                        return addAssign;
                }

                Expression *Pass1::handleIntrinsics( ApplicationExpr *appExpr ) {
                        if ( VariableExpr *varExpr = dynamic_cast< VariableExpr *>( appExpr->get_function() ) ) {
                                if ( varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic ) {
                                        if ( varExpr->get_var()->get_name() == "?[?]" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( appExpr->get_args().size() == 2 );
                                                Type *baseType1 = isPolyPtr( appExpr->get_args().front()->get_results().front(), scopeTyVars, env );
                                                Type *baseType2 = isPolyPtr( appExpr->get_args().back()->get_results().front(), scopeTyVars, env );
                                                assert( ! baseType1 || ! baseType2 ); // the arguments cannot both be polymorphic pointers
                                                UntypedExpr *ret = 0;
                                                if ( baseType1 || baseType2 ) { // one of the arguments is a polymorphic pointer
                                                        ret = new UntypedExpr( new NameExpr( "?+?" ) );
                                                } // if
                                                if ( baseType1 ) {
                                                        UntypedExpr *multiply = new UntypedExpr( new NameExpr( "?*?" ) );
                                                        multiply->get_args().push_back( appExpr->get_args().back() );
                                                        multiply->get_args().push_back( new NameExpr( sizeofName( baseType1 ) ) );
                                                        ret->get_args().push_back( appExpr->get_args().front() );
                                                        ret->get_args().push_back( multiply );
                                                } else if ( baseType2 ) {
                                                        UntypedExpr *multiply = new UntypedExpr( new NameExpr( "?*?" ) );
                                                        multiply->get_args().push_back( appExpr->get_args().front() );
                                                        multiply->get_args().push_back( new NameExpr( sizeofName( baseType2 ) ) );
                                                        ret->get_args().push_back( multiply );
                                                        ret->get_args().push_back( appExpr->get_args().back() );
                                                } // if
                                                if ( baseType1 || baseType2 ) {
                                                        ret->get_results().push_front( appExpr->get_results().front()->clone() );
                                                        if ( appExpr->get_env() ) {
                                                                ret->set_env( appExpr->get_env() );
                                                                appExpr->set_env( 0 );
                                                        } // if
                                                        appExpr->get_args().clear();
                                                        delete appExpr;
                                                        return ret;
                                                } // if
                                        } else if ( varExpr->get_var()->get_name() == "*?" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( ! appExpr->get_args().empty() );
                                                if ( isPolyType( appExpr->get_results().front(), scopeTyVars, env ) ) {
                                                        Expression *ret = appExpr->get_args().front();
                                                        delete ret->get_results().front();
                                                        ret->get_results().front() = appExpr->get_results().front()->clone();
                                                        if ( appExpr->get_env() ) {
                                                                ret->set_env( appExpr->get_env() );
                                                                appExpr->set_env( 0 );
                                                        } // if
                                                        appExpr->get_args().clear();
                                                        delete appExpr;
                                                        return ret;
                                                } // if
                                        } else if ( varExpr->get_var()->get_name() == "?++" || varExpr->get_var()->get_name() == "?--" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( appExpr->get_args().size() == 1 );
                                                if ( Type *baseType = isPolyPtr( appExpr->get_results().front(), scopeTyVars, env ) ) {
                                                        Type *tempType = appExpr->get_results().front()->clone();
                                                        if ( env ) {
                                                                env->apply( tempType );
                                                        } // if
                                                        ObjectDecl *newObj = makeTemporary( tempType );
                                                        VariableExpr *tempExpr = new VariableExpr( newObj );
                                                        UntypedExpr *assignExpr = new UntypedExpr( new NameExpr( "?=?" ) );
                                                        assignExpr->get_args().push_back( tempExpr->clone() );
                                                        if ( AddressExpr *address = dynamic_cast< AddressExpr *>( appExpr->get_args().front() ) ) {
                                                                assignExpr->get_args().push_back( address->get_arg()->clone() );
                                                        } else {
                                                                assignExpr->get_args().push_back( appExpr->get_args().front()->clone() );
                                                        } // if
                                                        CommaExpr *firstComma = new CommaExpr( assignExpr, makeIncrDecrExpr( appExpr, baseType, varExpr->get_var()->get_name() == "?++" ) );
                                                        return new CommaExpr( firstComma, tempExpr );
                                                } // if
                                        } else if ( varExpr->get_var()->get_name() == "++?" || varExpr->get_var()->get_name() == "--?" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( appExpr->get_args().size() == 1 );
                                                if ( Type *baseType = isPolyPtr( appExpr->get_results().front(), scopeTyVars, env ) ) {
                                                        return makeIncrDecrExpr( appExpr, baseType, varExpr->get_var()->get_name() == "++?" );
                                                } // if
                                        } else if ( varExpr->get_var()->get_name() == "?+?" || varExpr->get_var()->get_name() == "?-?" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( appExpr->get_args().size() == 2 );
                                                Type *baseType1 = isPolyPtr( appExpr->get_args().front()->get_results().front(), scopeTyVars, env );
                                                Type *baseType2 = isPolyPtr( appExpr->get_args().back()->get_results().front(), scopeTyVars, env );
                                                if ( baseType1 && baseType2 ) {
                                                        UntypedExpr *divide = new UntypedExpr( new NameExpr( "?/?" ) );
                                                        divide->get_args().push_back( appExpr );
                                                        divide->get_args().push_back( new NameExpr( sizeofName( baseType1 ) ) );
                                                        divide->get_results().push_front( appExpr->get_results().front()->clone() );
                                                        if ( appExpr->get_env() ) {
                                                                divide->set_env( appExpr->get_env() );
                                                                appExpr->set_env( 0 );
                                                        } // if
                                                        return divide;
                                                } else if ( baseType1 ) {
                                                        UntypedExpr *multiply = new UntypedExpr( new NameExpr( "?*?" ) );
                                                        multiply->get_args().push_back( appExpr->get_args().back() );
                                                        multiply->get_args().push_back( new NameExpr( sizeofName( baseType1 ) ) );
                                                        appExpr->get_args().back() = multiply;
                                                } else if ( baseType2 ) {
                                                        UntypedExpr *multiply = new UntypedExpr( new NameExpr( "?*?" ) );
                                                        multiply->get_args().push_back( appExpr->get_args().front() );
                                                        multiply->get_args().push_back( new NameExpr( sizeofName( baseType2 ) ) );
                                                        appExpr->get_args().front() = multiply;
                                                } // if
                                        } else if ( varExpr->get_var()->get_name() == "?+=?" || varExpr->get_var()->get_name() == "?-=?" ) {
                                                assert( ! appExpr->get_results().empty() );
                                                assert( appExpr->get_args().size() == 2 );
                                                Type *baseType = isPolyPtr( appExpr->get_results().front(), scopeTyVars, env );
                                                if ( baseType ) {
                                                        UntypedExpr *multiply = new UntypedExpr( new NameExpr( "?*?" ) );
                                                        multiply->get_args().push_back( appExpr->get_args().back() );
                                                        multiply->get_args().push_back( new NameExpr( sizeofName( baseType ) ) );
                                                        appExpr->get_args().back() = multiply;
                                                } // if
                                        } // if
                                        return appExpr;
                                } // if
                        } // if
                        return 0;
                }

                Expression *Pass1::mutate( ApplicationExpr *appExpr ) {
                        // std::cerr << "mutate appExpr: ";
                        // for ( TyVarMap::iterator i = scopeTyVars.begin(); i != scopeTyVars.end(); ++i ) {
                        //      std::cerr << i->first << " ";
                        // }
                        // std::cerr << "\n";
                        bool oldUseRetval = useRetval;
                        useRetval = false;
                        appExpr->get_function()->acceptMutator( *this );
                        mutateAll( appExpr->get_args(), *this );
                        useRetval = oldUseRetval;

                        assert( ! appExpr->get_function()->get_results().empty() );
                        PointerType *pointer = dynamic_cast< PointerType *>( appExpr->get_function()->get_results().front() );
                        assert( pointer );
                        FunctionType *function = dynamic_cast< FunctionType *>( pointer->get_base() );
                        assert( function );

                        if ( Expression *newExpr = handleIntrinsics( appExpr ) ) {
                                return newExpr;
                        } // if

                        Expression *ret = appExpr;

                        std::list< Expression *>::iterator arg = appExpr->get_args().begin();
                        std::list< Expression *>::iterator paramBegin = appExpr->get_args().begin();

                        TyVarMap exprTyVars;
                        makeTyVarMap( function, exprTyVars );
                        ReferenceToType *polyRetType = isPolyRet( function );

                        if ( polyRetType ) {
                                ret = addPolyRetParam( appExpr, function, polyRetType, arg );
                        } else if ( needsAdapter( function, scopeTyVars ) ) {
                                // std::cerr << "needs adapter: ";
                                // for ( TyVarMap::iterator i = scopeTyVars.begin(); i != scopeTyVars.end(); ++i ) {
                                //      std::cerr << i->first << " ";
                                // }
                                // std::cerr << "\n";
                                // change the application so it calls the adapter rather than the passed function
                                ret = applyAdapter( appExpr, function, arg, scopeTyVars );
                        } // if
                        arg = appExpr->get_args().begin();

                        passTypeVars( appExpr, polyRetType, arg, exprTyVars );
                        addInferredParams( appExpr, function, arg, exprTyVars );

                        arg = paramBegin;

                        boxParams( appExpr, function, arg, exprTyVars );

                        passAdapters( appExpr, function, exprTyVars );

                        return ret;
                }

                Expression *Pass1::mutate( UntypedExpr *expr ) {
                        if ( ! expr->get_results().empty() && isPolyType( expr->get_results().front(), scopeTyVars, env ) ) {
                                if ( NameExpr *name = dynamic_cast< NameExpr *>( expr->get_function() ) ) {
                                        if ( name->get_name() == "*?" ) {
                                                Expression *ret = expr->get_args().front();
                                                expr->get_args().clear();
                                                delete expr;
                                                return ret->acceptMutator( *this );
                                        } // if
                                } // if
                        } // if
                        return PolyMutator::mutate( expr );
                }

                Expression *Pass1::mutate( AddressExpr *addrExpr ) {
                        assert( ! addrExpr->get_arg()->get_results().empty() );

                        bool needs = false;
                        if ( UntypedExpr *expr = dynamic_cast< UntypedExpr *>( addrExpr->get_arg() ) ) {
                                if ( ! expr->get_results().empty() && isPolyType( expr->get_results().front(), scopeTyVars, env ) ) {
                                        if ( NameExpr *name = dynamic_cast< NameExpr *>( expr->get_function() ) ) {
                                                if ( name->get_name() == "*?" ) {
                                                        if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr->get_args().front() ) ) {
                                                                assert( ! appExpr->get_function()->get_results().empty() );
                                                                PointerType *pointer = dynamic_cast< PointerType *>( appExpr->get_function()->get_results().front() );
                                                                assert( pointer );
                                                                FunctionType *function = dynamic_cast< FunctionType *>( pointer->get_base() );
                                                                assert( function );
                                                                needs = needsAdapter( function, scopeTyVars );
                                                        } // if
                                                } // if
                                        } // if
                                } // if
                        } // if
                        addrExpr->set_arg( mutateExpression( addrExpr->get_arg() ) );
                        if ( isPolyType( addrExpr->get_arg()->get_results().front(), scopeTyVars, env ) || needs ) {
                                Expression *ret = addrExpr->get_arg();
                                delete ret->get_results().front();
                                ret->get_results().front() = addrExpr->get_results().front()->clone();
                                addrExpr->set_arg( 0 );
                                delete addrExpr;
                                return ret;
                        } else {
                                return addrExpr;
                        } // if
                }

                /// Wraps a function declaration in a new pointer-to-function variable expression
                VariableExpr *wrapFunctionDecl( DeclarationWithType *functionDecl ) {
                        // line below cloned from FixFunction.cc
                        ObjectDecl *functionObj = new ObjectDecl( functionDecl->get_name(), functionDecl->get_storageClass(), functionDecl->get_linkage(), 0,
                                                                  new PointerType( Type::Qualifiers(), functionDecl->get_type()->clone() ), 0 );
                        functionObj->set_mangleName( functionDecl->get_mangleName() );
                        return new VariableExpr( functionObj );
                }
                
                Statement * Pass1::mutate( ReturnStmt *returnStmt ) {
                        if ( retval && returnStmt->get_expr() ) {
                                assert( ! returnStmt->get_expr()->get_results().empty() );
                                // ***** Code Removal ***** After introducing a temporary variable for all return expressions, the following code appears superfluous.
                                // if ( returnStmt->get_expr()->get_results().front()->get_isLvalue() ) {
                                // by this point, a cast expr on a polymorphic return value is redundant
                                while ( CastExpr *castExpr = dynamic_cast< CastExpr *>( returnStmt->get_expr() ) ) {
                                        returnStmt->set_expr( castExpr->get_arg() );
                                        returnStmt->get_expr()->set_env( castExpr->get_env() );
                                        castExpr->set_env( 0 );
                                        castExpr->set_arg( 0 );
                                        delete castExpr;
                                } //while

                                // find assignment operator for (polymorphic) return type
                                ApplicationExpr *assignExpr = 0;
                                if ( TypeInstType *typeInst = dynamic_cast< TypeInstType *>( retval->get_type() ) ) {
                                        // find assignment operator for type variable
                                        std::map< std::string, DeclarationWithType *>::const_iterator assignIter = assignOps.find( typeInst->get_name() );
                                        if ( assignIter == assignOps.end() ) {
                                                throw SemanticError( "Attempt to return dtype or ftype object in ", returnStmt->get_expr() );
                                        } // if
                                        assignExpr = new ApplicationExpr( new VariableExpr( assignIter->second ) );
                                } else if ( ReferenceToType *refType = dynamic_cast< ReferenceToType *>( retval->get_type() ) ) {
                                        // find assignment operator for generic type
                                        DeclarationWithType *functionDecl = scopedAssignOps.find( refType );
                                        if ( ! functionDecl ) {
                                                throw SemanticError( "Attempt to return dtype or ftype generic object in ", returnStmt->get_expr() );
                                        }

                                        // wrap it up in an application expression
                                        assignExpr = new ApplicationExpr( wrapFunctionDecl( functionDecl ) );
                                        assignExpr->set_env( env->clone() );

                                        // find each of its needed secondary assignment operators
                                        std::list< Expression* > &tyParams = refType->get_parameters();
                                        std::list< TypeDecl* > &forallParams = functionDecl->get_type()->get_forall();
                                        std::list< Expression* >::const_iterator tyIt = tyParams.begin();
                                        std::list< TypeDecl* >::const_iterator forallIt = forallParams.begin();
                                        for ( ; tyIt != tyParams.end() && forallIt != forallParams.end(); ++tyIt, ++forallIt ) {
                                                if ( (*forallIt)->get_kind() != TypeDecl::Any ) continue; // skip types with no assign op (ftype/dtype)

                                                std::list< DeclarationWithType* > &asserts = (*forallIt)->get_assertions();
                                                assert( ! asserts.empty() && "Type param needs assignment operator assertion" );
                                                DeclarationWithType *actualDecl = asserts.front();
                                                TypeInstType *actualType = isTypeInstAssignment( actualDecl );
                                                assert( actualType && "First assertion of type with assertions should be assignment operator" );
                                                TypeExpr *formalTypeExpr = dynamic_cast< TypeExpr* >( *tyIt );
                                                assert( formalTypeExpr && "type parameters must be type expressions" );
                                                Type *formalType = formalTypeExpr->get_type();
                                                assignExpr->get_env()->add( actualType->get_name(), formalType );
                                                
                                                DeclarationWithType *assertAssign = 0;
                                                if ( TypeInstType *formalTypeInstType = dynamic_cast< TypeInstType* >( formalType ) ) {
                                                        std::map< std::string, DeclarationWithType *>::const_iterator assertAssignIt = assignOps.find( formalTypeInstType->get_name() );
                                                        if ( assertAssignIt == assignOps.end() ) {
                                                                throw SemanticError( "No assignment operation found for ", formalTypeInstType );
                                                        }
                                                        assertAssign = assertAssignIt->second;
                                                } else {
                                                        assertAssign = scopedAssignOps.find( formalType );
                                                        if ( ! assertAssign ) {
                                                                throw SemanticError( "No assignment operation found for ", formalType );
                                                        }
                                                }
                                                

                                                assignExpr->get_inferParams()[ actualDecl->get_uniqueId() ]
                                                        = ParamEntry( assertAssign->get_uniqueId(), assertAssign->get_type()->clone(), actualDecl->get_type()->clone(), wrapFunctionDecl( assertAssign ) );
                                        }
                                }
                                assert( assignExpr );

                                // replace return statement with appropriate assignment to out parameter
                                Expression *retParm = new NameExpr( retval->get_name() );
                                retParm->get_results().push_back( new PointerType( Type::Qualifiers(), retval->get_type()->clone() ) );
                                assignExpr->get_args().push_back( retParm );
                                assignExpr->get_args().push_back( returnStmt->get_expr() );
                                stmtsToAdd.push_back( new ExprStmt( noLabels, mutateExpression( assignExpr ) ) );
                                // } else {
                                //      useRetval = true;
                                //      stmtsToAdd.push_back( new ExprStmt( noLabels, mutateExpression( returnStmt->get_expr() ) ) );
                                //      useRetval = false;
                                // } // if
                                returnStmt->set_expr( 0 );
                        } else {
                                returnStmt->set_expr( mutateExpression( returnStmt->get_expr() ) );
                        } // if
                        return returnStmt;
                }

                Type * Pass1::mutate( PointerType *pointerType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( pointerType, scopeTyVars );

                        Type *ret = Mutator::mutate( pointerType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                Type * Pass1::mutate( FunctionType *functionType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( functionType, scopeTyVars );

                        Type *ret = Mutator::mutate( functionType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                void Pass1::doBeginScope() {
                        adapters.beginScope();
                        scopedAssignOps.beginScope();
                }

                void Pass1::doEndScope() {
                        adapters.endScope();
                        scopedAssignOps.endScope();
                }

////////////////////////////////////////// Pass2 ////////////////////////////////////////////////////

                void Pass2::addAdapters( FunctionType *functionType ) {
                        std::list< DeclarationWithType *> &paramList = functionType->get_parameters();
                        std::list< FunctionType *> functions;
                        for ( std::list< DeclarationWithType *>::iterator arg = paramList.begin(); arg != paramList.end(); ++arg ) {
                                Type *orig = (*arg)->get_type();
                                findAndReplaceFunction( orig, functions, scopeTyVars, needsAdapter );
                                (*arg)->set_type( orig );
                        }
                        std::set< std::string > adaptersDone;
                        for ( std::list< FunctionType *>::iterator funType = functions.begin(); funType != functions.end(); ++funType ) {
                                std::string mangleName = mangleAdapterName( *funType, scopeTyVars );
                                if ( adaptersDone.find( mangleName ) == adaptersDone.end() ) {
                                        std::string adapterName = makeAdapterName( mangleName );
                                        paramList.push_front( new ObjectDecl( adapterName, DeclarationNode::NoStorageClass, LinkageSpec::C, 0, new PointerType( Type::Qualifiers(), makeAdapterType( *funType, scopeTyVars ) ), 0 ) );
                                        adaptersDone.insert( adaptersDone.begin(), mangleName );
                                }
                        }
//  deleteAll( functions );
                }

                template< typename DeclClass >
                DeclClass * Pass2::handleDecl( DeclClass *decl, Type *type ) {
                        DeclClass *ret = static_cast< DeclClass *>( Mutator::mutate( decl ) );

                        return ret;
                }

                DeclarationWithType * Pass2::mutate( FunctionDecl *functionDecl ) {
                        return handleDecl( functionDecl, functionDecl->get_functionType() );
                }

                ObjectDecl * Pass2::mutate( ObjectDecl *objectDecl ) {
                        return handleDecl( objectDecl, objectDecl->get_type() );
                }

                TypeDecl * Pass2::mutate( TypeDecl *typeDecl ) {
                        scopeTyVars[ typeDecl->get_name() ] = typeDecl->get_kind();
                        if ( typeDecl->get_base() ) {
                                return handleDecl( typeDecl, typeDecl->get_base() );
                        } else {
                                return Mutator::mutate( typeDecl );
                        }
                }

                TypedefDecl * Pass2::mutate( TypedefDecl *typedefDecl ) {
                        return handleDecl( typedefDecl, typedefDecl->get_base() );
                }

                Type * Pass2::mutate( PointerType *pointerType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( pointerType, scopeTyVars );

                        Type *ret = Mutator::mutate( pointerType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                Type *Pass2::mutate( FunctionType *funcType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( funcType, scopeTyVars );

                        // move polymorphic return type to parameter list
                        if ( isPolyRet( funcType ) ) {
                                DeclarationWithType *ret = funcType->get_returnVals().front();
                                ret->set_type( new PointerType( Type::Qualifiers(), ret->get_type() ) );
                                funcType->get_parameters().push_front( ret );
                                funcType->get_returnVals().pop_front();
                        }

                        // add size/align and assertions for type parameters to parameter list
                        std::list< DeclarationWithType *>::iterator last = funcType->get_parameters().begin();
                        std::list< DeclarationWithType *> inferredParams;
                        ObjectDecl newObj( "", DeclarationNode::NoStorageClass, LinkageSpec::C, 0, new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), 0 );
                        ObjectDecl newPtr( "", DeclarationNode::NoStorageClass, LinkageSpec::C, 0,
                                           new PointerType( Type::Qualifiers(), new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ) ), 0 );
                        for ( std::list< TypeDecl *>::const_iterator tyParm = funcType->get_forall().begin(); tyParm != funcType->get_forall().end(); ++tyParm ) {
                                ObjectDecl *sizeParm, *alignParm;
                                // add all size and alignment parameters to parameter list
                                if ( (*tyParm)->get_kind() == TypeDecl::Any ) {
                                        TypeInstType parmType( Type::Qualifiers(), (*tyParm)->get_name(), *tyParm );

                                        sizeParm = newObj.clone();
                                        sizeParm->set_name( sizeofName( &parmType ) );
                                        last = funcType->get_parameters().insert( last, sizeParm );
                                        ++last;

                                        alignParm = newObj.clone();
                                        alignParm->set_name( alignofName( &parmType ) );
                                        last = funcType->get_parameters().insert( last, alignParm );
                                        ++last;
                                }
                                // move all assertions into parameter list
                                for ( std::list< DeclarationWithType *>::iterator assert = (*tyParm)->get_assertions().begin(); assert != (*tyParm)->get_assertions().end(); ++assert ) {
//      *assert = (*assert)->acceptMutator( *this );
                                        inferredParams.push_back( *assert );
                                }
                                (*tyParm)->get_assertions().clear();
                        }

                        // add size/align for generic parameter types to parameter list
                        std::set< std::string > seenTypes; // sizeofName for generic types we've seen
                        for ( std::list< DeclarationWithType* >::const_iterator fnParm = last; fnParm != funcType->get_parameters().end(); ++fnParm ) {
                                Type *polyBase = hasPolyBase( (*fnParm)->get_type(), scopeTyVars );
                                if ( polyBase && ! dynamic_cast< TypeInstType* >( polyBase ) ) {
                                        std::string sizeName = sizeofName( polyBase );
                                        if ( seenTypes.count( sizeName ) ) continue;

                                        ObjectDecl *sizeParm, *alignParm, *offsetParm;
                                        sizeParm = newObj.clone();
                                        sizeParm->set_name( sizeName );
                                        last = funcType->get_parameters().insert( last, sizeParm );
                                        ++last;

                                        alignParm = newObj.clone();
                                        alignParm->set_name( alignofName( polyBase ) );
                                        last = funcType->get_parameters().insert( last, alignParm );
                                        ++last;

                                        if ( StructInstType *polyBaseStruct = dynamic_cast< StructInstType* >( polyBase ) ) {
                                                // NOTE zero-length arrays are illegal in C, so empty structs have no offset array
                                                if ( ! polyBaseStruct->get_baseStruct()->get_members().empty() ) {
                                                        offsetParm = newPtr.clone();
                                                        offsetParm->set_name( offsetofName( polyBase ) );
                                                        last = funcType->get_parameters().insert( last, offsetParm );
                                                        ++last;
                                                }
                                        }

                                        seenTypes.insert( sizeName );
                                        knownLayouts.insert( sizeName );  // make sure that any type information passed into the function is accounted for
                                }
                        }

                        // splice assertion parameters into parameter list
                        funcType->get_parameters().splice( last, inferredParams );
                        addAdapters( funcType );
                        mutateAll( funcType->get_returnVals(), *this );
                        mutateAll( funcType->get_parameters(), *this );

                        scopeTyVars = oldtyVars;
                        return funcType;
                }

                ObjectDecl *Pass2::makeVar( const std::string &name, Type *type, Initializer *init ) {
                        ObjectDecl *newObj = new ObjectDecl( name, DeclarationNode::NoStorageClass, LinkageSpec::C, 0, type, init );
                        stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
                        return newObj;
                }

                void Pass2::addOtypeParamsToLayoutCall( UntypedExpr *layoutCall, const std::list< Type* > &otypeParams ) {
                        for ( std::list< Type* >::const_iterator param = otypeParams.begin(); param != otypeParams.end(); ++param ) {
                                if ( findGeneric( *param ) ) {
                                        // push size/align vars for a generic parameter back
                                        layoutCall->get_args().push_back( new NameExpr( sizeofName( *param ) ) );
                                        layoutCall->get_args().push_back( new NameExpr( alignofName( *param ) ) );
                                } else {
                                        layoutCall->get_args().push_back( new SizeofExpr( (*param)->clone() ) );
                                        layoutCall->get_args().push_back( new AlignofExpr( (*param)->clone() ) );
                                }
                        }
                }

                /// returns true if any of the otype parameters have a dynamic layout and puts all otype parameters in the output list
                bool findGenericParams( std::list< TypeDecl* > &baseParams, std::list< Expression* > &typeParams, std::list< Type* > &out ) {
                        bool hasDynamicLayout = false;

                        std::list< TypeDecl* >::const_iterator baseParam = baseParams.begin();
                        std::list< Expression* >::const_iterator typeParam = typeParams.begin();
                        for ( ; baseParam != baseParams.end() && typeParam != typeParams.end(); ++baseParam, ++typeParam ) {
                                // skip non-otype parameters
                                if ( (*baseParam)->get_kind() != TypeDecl::Any ) continue;
                                TypeExpr *typeExpr = dynamic_cast< TypeExpr* >( *typeParam );
                                assert( typeExpr && "all otype parameters should be type expressions" );

                                Type *type = typeExpr->get_type();
                                out.push_back( type );
                                if ( isPolyType( type ) ) hasDynamicLayout = true;
                        }
                        assert( baseParam == baseParams.end() && typeParam == typeParams.end() );

                        return hasDynamicLayout;
                }
                
                bool Pass2::findGeneric( Type *ty ) {
                        if ( dynamic_cast< TypeInstType* >( ty ) ) {
                                // NOTE this assumes that all type variables will be properly bound, and thus have their layouts in scope
                                return true;
                        } else if ( StructInstType *structTy = dynamic_cast< StructInstType* >( ty ) ) {
                                // check if this type already has a layout generated for it
                                std::string sizeName = sizeofName( ty );
                                if ( knownLayouts.find( sizeName ) != knownLayouts.end() ) return true;
                                
                                // check if any of the type parameters have dynamic layout; if none do, this type is (or will be) monomorphized
                                std::list< Type* > otypeParams;
                                if ( ! findGenericParams( *structTy->get_baseParameters(), structTy->get_parameters(), otypeParams ) ) return false;

                                // insert local variables for layout and generate call to layout function
                                knownLayouts.insert( sizeName );  // done early so as not to interfere with the later addition of parameters to the layout call
                                Type *layoutType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );

                                int n_members = structTy->get_baseStruct()->get_members().size();
                                if ( n_members == 0 ) {
                                        // all empty structs have the same layout - size 1, align 1
                                        makeVar( sizeName, layoutType, new SingleInit( new ConstantExpr( Constant::from( (unsigned long)1 ) ) ) );
                                        makeVar( alignofName( ty ), layoutType->clone(), new SingleInit( new ConstantExpr( Constant::from( (unsigned long)1 ) ) ) );
                                        // NOTE zero-length arrays are forbidden in C, so empty structs have no offsetof array
                                } else {
                                        ObjectDecl *sizeVar = makeVar( sizeName, layoutType );
                                        ObjectDecl *alignVar = makeVar( alignofName( ty ), layoutType->clone() );
                                        ObjectDecl *offsetVar = makeVar( offsetofName( ty ), new ArrayType( Type::Qualifiers(), layoutType->clone(), new ConstantExpr( Constant::from( n_members ) ), false, false ) );

                                        // generate call to layout function
                                        UntypedExpr *layoutCall = new UntypedExpr( new NameExpr( "__layoutof_" + structTy->get_baseStruct()->get_name() ) );
                                        layoutCall->get_args().push_back( new AddressExpr( new VariableExpr( sizeVar ) ) );
                                        layoutCall->get_args().push_back( new AddressExpr( new VariableExpr( alignVar ) ) );
                                        layoutCall->get_args().push_back( new VariableExpr( offsetVar ) );
                                        addOtypeParamsToLayoutCall( layoutCall, otypeParams );

                                        stmtsToAdd.push_back( new ExprStmt( noLabels, layoutCall ) );
                                }
                                
                                return true;
                        } else if ( UnionInstType *unionTy = dynamic_cast< UnionInstType* >( ty ) ) {
                                // check if this type already has a layout generated for it
                                std::string sizeName = sizeofName( ty );
                                if ( knownLayouts.find( sizeName ) != knownLayouts.end() ) return true;
                                
                                // check if any of the type parameters have dynamic layout; if none do, this type is (or will be) monomorphized
                                std::list< Type* > otypeParams;
                                if ( ! findGenericParams( *unionTy->get_baseParameters(), unionTy->get_parameters(), otypeParams ) ) return false;

                                // insert local variables for layout and generate call to layout function
                                knownLayouts.insert( sizeName );  // done early so as not to interfere with the later addition of parameters to the layout call
                                Type *layoutType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );

                                ObjectDecl *sizeVar = makeVar( sizeName, layoutType );
                                ObjectDecl *alignVar = makeVar( alignofName( ty ), layoutType->clone() );
                                
                                // generate call to layout function
                                UntypedExpr *layoutCall = new UntypedExpr( new NameExpr( "__layoutof_" + unionTy->get_baseUnion()->get_name() ) );
                                layoutCall->get_args().push_back( new AddressExpr( new VariableExpr( sizeVar ) ) );
                                layoutCall->get_args().push_back( new AddressExpr( new VariableExpr( alignVar ) ) );
                                addOtypeParamsToLayoutCall( layoutCall, otypeParams );

                                stmtsToAdd.push_back( new ExprStmt( noLabels, layoutCall ) );

                                return true;
                        }
                        
                        return false;
                }
                
                Expression *Pass2::mutate( SizeofExpr *sizeofExpr ) {
                        Type *ty = sizeofExpr->get_type();
                        if ( findGeneric( ty ) ) {
                                Expression *ret = new NameExpr( sizeofName( ty ) );
                                delete sizeofExpr;
                                return ret;
                        }
                        return sizeofExpr;
                }

                Expression *Pass2::mutate( AlignofExpr *alignofExpr ) {
                        Type *ty = alignofExpr->get_type();
                        if ( findGeneric( ty ) ) {
                                Expression *ret = new NameExpr( alignofName( ty ) );
                                delete alignofExpr;
                                return ret;
                        }
                        return alignofExpr;
                }

                Expression *Pass2::mutate( OffsetofExpr *offsetofExpr ) {
                        findGeneric( offsetofExpr->get_type() );
                        return offsetofExpr;
                }

                Expression *Pass2::mutate( OffsetPackExpr *offsetPackExpr ) {
                        StructInstType *ty = offsetPackExpr->get_type();

                        Expression *ret = 0;
                        if ( findGeneric( ty ) ) {
                                // pull offset back from generated type information
                                ret = new NameExpr( offsetofName( ty ) );
                        } else {
                                std::string offsetName = offsetofName( ty );
                                if ( knownOffsets.find( offsetName ) != knownOffsets.end() ) {
                                        // use the already-generated offsets for this type
                                        ret = new NameExpr( offsetName );
                                } else {
                                        std::list< Declaration* > &baseMembers = ty->get_baseStruct()->get_members();
                                        Type *offsetType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );

                                        // build initializer list for offset array
                                        std::list< Initializer* > inits;
                                        for ( std::list< Declaration* >::const_iterator member = baseMembers.begin(); member != baseMembers.end(); ++member ) {
                                                DeclarationWithType *memberDecl;
                                                if ( DeclarationWithType *origMember = dynamic_cast< DeclarationWithType* >( *member ) ) {
                                                        memberDecl = origMember->clone();
                                                } else {
                                                        memberDecl = new ObjectDecl( (*member)->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, offsetType->clone(), 0 );
                                                }
                                                inits.push_back( new SingleInit( new OffsetofExpr( ty->clone(), memberDecl ) ) );
                                        }

                                        // build the offset array and replace the pack with a reference to it
                                        ObjectDecl *offsetArray = makeVar( offsetName, new ArrayType( Type::Qualifiers(), offsetType, new ConstantExpr( Constant::from( baseMembers.size() ) ), false, false ),
                                                        new ListInit( inits ) );
                                        ret = new VariableExpr( offsetArray );
                                }
                        }

                        delete offsetPackExpr;
                        return ret;
                }

                void Pass2::doBeginScope() {
                        knownLayouts.beginScope();
                        knownOffsets.beginScope();
                }
                
                void Pass2::doEndScope() {
                        knownLayouts.endScope();
                        knownOffsets.beginScope();
                }

//////////////////////////////////////// GenericInstantiator //////////////////////////////////////////////////

                /// Makes substitutions of params into baseParams; returns true if all parameters substituted for a concrete type
                bool makeSubstitutions( const std::list< TypeDecl* >& baseParams, const std::list< Expression* >& params, std::list< TypeExpr* >& out ) {
                        bool allConcrete = true;  // will finish the substitution list even if they're not all concrete

                        // substitute concrete types for given parameters, and incomplete types for placeholders
                        std::list< TypeDecl* >::const_iterator baseParam = baseParams.begin();
                        std::list< Expression* >::const_iterator param = params.begin();
                        for ( ; baseParam != baseParams.end() && param != params.end(); ++baseParam, ++param ) {
        //                      switch ( (*baseParam)->get_kind() ) {
        //                      case TypeDecl::Any: {   // any type is a valid substitution here; complete types can be used to instantiate generics
                                        TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
                                        assert(paramType && "Aggregate parameters should be type expressions");
                                        out.push_back( paramType->clone() );
                                        // check that the substituted type isn't a type variable itself
                                        if ( dynamic_cast< TypeInstType* >( paramType->get_type() ) ) {
                                                allConcrete = false;
                                        }
        //                              break;
        //                      }
        //                      case TypeDecl::Dtype:  // dtype can be consistently replaced with void [only pointers, which become void*]
        //                              out.push_back( new TypeExpr( new VoidType( Type::Qualifiers() ) ) );
        //                              break;
        //                      case TypeDecl::Ftype:  // pointer-to-ftype can be consistently replaced with void (*)(void) [similar to dtype]
        //                              out.push_back( new TypeExpr( new FunctionType( Type::Qualifiers(), false ) ) );
        //                              break;
        //                      }
                        }

                        // if any parameters left over, not done
                        if ( baseParam != baseParams.end() ) return false;
        //              // if not enough parameters given, substitute remaining incomplete types for placeholders
        //              for ( ; baseParam != baseParams.end(); ++baseParam ) {
        //                      switch ( (*baseParam)->get_kind() ) {
        //                      case TypeDecl::Any:    // no more substitutions here, fail early
        //                              return false;
        //                      case TypeDecl::Dtype:  // dtype can be consistently replaced with void [only pointers, which become void*]
        //                              out.push_back( new TypeExpr( new VoidType( Type::Qualifiers() ) ) );
        //                              break;
        //                      case TypeDecl::Ftype:  // pointer-to-ftype can be consistently replaced with void (*)(void) [similar to dtype]
        //                              out.push_back( new TypeExpr( new FunctionType( Type::Qualifiers(), false ) ) );
        //                              break;
        //                      }
        //              }

                        return allConcrete;
                }

                /// Substitutes types of members of in according to baseParams => typeSubs, appending the result to out
                void substituteMembers( const std::list< Declaration* >& in, const std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs,
                                                                std::list< Declaration* >& out ) {
                        // substitute types into new members
                        TypeSubstitution subs( baseParams.begin(), baseParams.end(), typeSubs.begin() );
                        for ( std::list< Declaration* >::const_iterator member = in.begin(); member != in.end(); ++member ) {
                                Declaration *newMember = (*member)->clone();
                                subs.apply(newMember);
                                out.push_back( newMember );
                        }
                }

                Type* GenericInstantiator::mutate( StructInstType *inst ) {
                        // mutate subtypes
                        Type *mutated = Mutator::mutate( inst );
                        inst = dynamic_cast< StructInstType* >( mutated );
                        if ( ! inst ) return mutated;

                        // exit early if no need for further mutation
                        if ( inst->get_parameters().empty() ) return inst;
                        assert( inst->get_baseParameters() && "Base struct has parameters" );

                        // check if type can be concretely instantiated; put substitutions into typeSubs
                        std::list< TypeExpr* > typeSubs;
                        if ( ! makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs ) ) {
                                deleteAll( typeSubs );
                                return inst;
                        }

                        // make concrete instantiation of generic type
                        StructDecl *concDecl = lookup( inst, typeSubs );
                        if ( ! concDecl ) {
                                // set concDecl to new type, insert type declaration into statements to add
                                concDecl = new StructDecl( typeNamer.newName( inst->get_name() ) );
                                substituteMembers( inst->get_baseStruct()->get_members(), *inst->get_baseParameters(), typeSubs,        concDecl->get_members() );
                                DeclMutator::addDeclaration( concDecl );
                                insert( inst, typeSubs, concDecl );
                        }
                        StructInstType *newInst = new StructInstType( inst->get_qualifiers(), concDecl->get_name() );
                        newInst->set_baseStruct( concDecl );

                        deleteAll( typeSubs );
                        delete inst;
                        return newInst;
                }

                Type* GenericInstantiator::mutate( UnionInstType *inst ) {
                        // mutate subtypes
                        Type *mutated = Mutator::mutate( inst );
                        inst = dynamic_cast< UnionInstType* >( mutated );
                        if ( ! inst ) return mutated;

                        // exit early if no need for further mutation
                        if ( inst->get_parameters().empty() ) return inst;
                        assert( inst->get_baseParameters() && "Base union has parameters" );

                        // check if type can be concretely instantiated; put substitutions into typeSubs
                        std::list< TypeExpr* > typeSubs;
                        if ( ! makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs ) ) {
                                deleteAll( typeSubs );
                                return inst;
                        }

                        // make concrete instantiation of generic type
                        UnionDecl *concDecl = lookup( inst, typeSubs );
                        if ( ! concDecl ) {
                                // set concDecl to new type, insert type declaration into statements to add
                                concDecl = new UnionDecl( typeNamer.newName( inst->get_name() ) );
                                substituteMembers( inst->get_baseUnion()->get_members(), *inst->get_baseParameters(), typeSubs, concDecl->get_members() );
                                DeclMutator::addDeclaration( concDecl );
                                insert( inst, typeSubs, concDecl );
                        }
                        UnionInstType *newInst = new UnionInstType( inst->get_qualifiers(), concDecl->get_name() );
                        newInst->set_baseUnion( concDecl );

                        deleteAll( typeSubs );
                        delete inst;
                        return newInst;
                }

        //      /// Gets the base struct or union declaration for a member expression; NULL if not applicable
        //      AggregateDecl* getMemberBaseDecl( MemberExpr *memberExpr ) {
        //              // get variable for member aggregate
        //              VariableExpr *varExpr = dynamic_cast< VariableExpr* >( memberExpr->get_aggregate() );
        //              if ( ! varExpr ) return NULL;
        //
        //              // get object for variable
        //              ObjectDecl *objectDecl = dynamic_cast< ObjectDecl* >( varExpr->get_var() );
        //              if ( ! objectDecl ) return NULL;
        //
        //              // get base declaration from object type
        //              Type *objectType = objectDecl->get_type();
        //              StructInstType *structType = dynamic_cast< StructInstType* >( objectType );
        //              if ( structType ) return structType->get_baseStruct();
        //              UnionInstType *unionType = dynamic_cast< UnionInstType* >( objectType );
        //              if ( unionType ) return unionType->get_baseUnion();
        //
        //              return NULL;
        //      }
        //
        //      /// Finds the declaration with the given name, returning decls.end() if none such
        //      std::list< Declaration* >::const_iterator findDeclNamed( const std::list< Declaration* > &decls, const std::string &name ) {
        //              for( std::list< Declaration* >::const_iterator decl = decls.begin(); decl != decls.end(); ++decl ) {
        //                      if ( (*decl)->get_name() == name ) return decl;
        //              }
        //              return decls.end();
        //      }
        //
        //      Expression* Instantiate::mutate( MemberExpr *memberExpr ) {
        //              // mutate, exiting early if no longer MemberExpr
        //              Expression *expr = Mutator::mutate( memberExpr );
        //              memberExpr = dynamic_cast< MemberExpr* >( expr );
        //              if ( ! memberExpr ) return expr;
        //
        //              // get declaration of member and base declaration of member, exiting early if not found
        //              AggregateDecl *memberBase = getMemberBaseDecl( memberExpr );
        //              if ( ! memberBase ) return memberExpr;
        //              DeclarationWithType *memberDecl = memberExpr->get_member();
        //              std::list< Declaration* >::const_iterator baseIt = findDeclNamed( memberBase->get_members(), memberDecl->get_name() );
        //              if ( baseIt == memberBase->get_members().end() ) return memberExpr;
        //              DeclarationWithType *baseDecl = dynamic_cast< DeclarationWithType* >( *baseIt );
        //              if ( ! baseDecl ) return memberExpr;
        //
        //              // check if stated type of the member is not the type of the member's declaration; if so, need a cast
        //              // this *SHOULD* be safe, I don't think anything but the void-replacements I put in for dtypes would make it past the typechecker
        //              SymTab::Indexer dummy;
        //              if ( ResolvExpr::typesCompatible( memberDecl->get_type(), baseDecl->get_type(), dummy ) ) return memberExpr;
        //              else return new CastExpr( memberExpr, memberDecl->get_type() );
        //      }

                void GenericInstantiator::doBeginScope() {
                        DeclMutator::doBeginScope();
                        instantiations.beginScope();
                }

                void GenericInstantiator::doEndScope() {
                        DeclMutator::doEndScope();
                        instantiations.endScope();
                }

////////////////////////////////////////// MemberExprFixer ////////////////////////////////////////////////////

                template< typename DeclClass >
                DeclClass * MemberExprFixer::handleDecl( DeclClass *decl, Type *type ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( type, scopeTyVars );

                        DeclClass *ret = static_cast< DeclClass *>( Mutator::mutate( decl ) );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                ObjectDecl * MemberExprFixer::mutate( ObjectDecl *objectDecl ) {
                        return handleDecl( objectDecl, objectDecl->get_type() );
                }

                DeclarationWithType * MemberExprFixer::mutate( FunctionDecl *functionDecl ) {
                        return handleDecl( functionDecl, functionDecl->get_functionType() );
                }

                TypedefDecl * MemberExprFixer::mutate( TypedefDecl *typedefDecl ) {
                        return handleDecl( typedefDecl, typedefDecl->get_base() );
                }

                TypeDecl * MemberExprFixer::mutate( TypeDecl *typeDecl ) {
                        scopeTyVars[ typeDecl->get_name() ] = typeDecl->get_kind();
                        return Mutator::mutate( typeDecl );
                }

                Type * MemberExprFixer::mutate( PointerType *pointerType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( pointerType, scopeTyVars );

                        Type *ret = Mutator::mutate( pointerType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                Type * MemberExprFixer::mutate( FunctionType *functionType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( functionType, scopeTyVars );

                        Type *ret = Mutator::mutate( functionType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                Statement *MemberExprFixer::mutate( DeclStmt *declStmt ) {
                        if ( ObjectDecl *objectDecl = dynamic_cast< ObjectDecl *>( declStmt->get_decl() ) ) {
                                if ( isPolyType( objectDecl->get_type(), scopeTyVars ) ) {
                                        // change initialization of a polymorphic value object
                                        // to allocate storage with alloca
                                        Type *declType = objectDecl->get_type();
                                        UntypedExpr *alloc = new UntypedExpr( new NameExpr( "__builtin_alloca" ) );
                                        alloc->get_args().push_back( new NameExpr( sizeofName( declType ) ) );

                                        delete objectDecl->get_init();

                                        std::list<Expression*> designators;
                                        objectDecl->set_init( new SingleInit( alloc, designators ) );
                                }
                        }
                        return Mutator::mutate( declStmt );
                }

                /// Finds the member in the base list that matches the given declaration; returns its index, or -1 if not present
                long findMember( DeclarationWithType *memberDecl, std::list< Declaration* > &baseDecls ) {
                        long i = 0;
                        for(std::list< Declaration* >::const_iterator decl = baseDecls.begin(); decl != baseDecls.end(); ++decl, ++i ) {
                                if ( memberDecl->get_name() != (*decl)->get_name() ) continue;

                                if ( DeclarationWithType *declWithType = dynamic_cast< DeclarationWithType* >( *decl ) ) {
                                        if ( memberDecl->get_mangleName().empty() || declWithType->get_mangleName().empty()
                                             || memberDecl->get_mangleName() == declWithType->get_mangleName() ) return i;
                                        else continue;
                                } else return i;
                        }
                        return -1;
                }

                /// Returns an index expression into the offset array for a type
                Expression *makeOffsetIndex( Type *objectType, long i ) {
                        std::stringstream offset_namer;
                        offset_namer << i;
                        ConstantExpr *fieldIndex = new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), offset_namer.str() ) );
                        UntypedExpr *fieldOffset = new UntypedExpr( new NameExpr( "?[?]" ) );
                        fieldOffset->get_args().push_back( new NameExpr( offsetofName( objectType ) ) );
                        fieldOffset->get_args().push_back( fieldIndex );
                        return fieldOffset;
                }

                /// Returns an expression dereferenced n times
                Expression *makeDerefdVar( Expression *derefdVar, long n ) {
                        for ( int i = 1; i < n; ++i ) {
                                UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
                                derefExpr->get_args().push_back( derefdVar );
                                derefdVar = derefExpr;
                        }
                        return derefdVar;
                }
                
                Expression *MemberExprFixer::mutate( MemberExpr *memberExpr ) {
                        // mutate, exiting early if no longer MemberExpr
                        Expression *expr = Mutator::mutate( memberExpr );
                        memberExpr = dynamic_cast< MemberExpr* >( expr );
                        if ( ! memberExpr ) return expr;

                        // get declaration for base struct, exiting early if not found
                        int varDepth;
                        VariableExpr *varExpr = getBaseVar( memberExpr->get_aggregate(), &varDepth );
                        if ( ! varExpr ) return memberExpr;
                        ObjectDecl *objectDecl = dynamic_cast< ObjectDecl* >( varExpr->get_var() );
                        if ( ! objectDecl ) return memberExpr;

                        // only mutate member expressions for polymorphic types
                        int tyDepth;
                        Type *objectType = hasPolyBase( objectDecl->get_type(), scopeTyVars, &tyDepth );
                        if ( ! objectType ) return memberExpr;

                        Expression *newMemberExpr = 0;
                        if ( StructInstType *structType = dynamic_cast< StructInstType* >( objectType ) ) {
                                // look up offset index
                                long i = findMember( memberExpr->get_member(), structType->get_baseStruct()->get_members() );
                                if ( i == -1 ) return memberExpr;

                                // replace member expression with pointer to base plus offset
                                UntypedExpr *fieldLoc = new UntypedExpr( new NameExpr( "?+?" ) );
                                fieldLoc->get_args().push_back( makeDerefdVar( varExpr->clone(), varDepth ) );
                                fieldLoc->get_args().push_back( makeOffsetIndex( objectType, i ) );
                                newMemberExpr = fieldLoc;
                        } else if ( dynamic_cast< UnionInstType* >( objectType ) ) {
                                // union members are all at offset zero, so build appropriately-dereferenced variable
                                newMemberExpr = makeDerefdVar( varExpr->clone(), varDepth );
                        } else return memberExpr;
                        assert( newMemberExpr );

                        Type *memberType = memberExpr->get_member()->get_type();
                        if ( ! isPolyType( memberType, scopeTyVars ) ) {
                                // Not all members of a polymorphic type are themselves of polymorphic type; in this case the member expression should be wrapped and dereferenced to form an lvalue
                                CastExpr *ptrCastExpr = new CastExpr( newMemberExpr, new PointerType( Type::Qualifiers(), memberType->clone() ) );
                                UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
                                derefExpr->get_args().push_back( ptrCastExpr );
                                newMemberExpr = derefExpr;
                        }

                        delete memberExpr;
                        return newMemberExpr;
                }

                Expression *MemberExprFixer::mutate( OffsetofExpr *offsetofExpr ) {
                        // mutate, exiting early if no longer OffsetofExpr
                        Expression *expr = Mutator::mutate( offsetofExpr );
                        offsetofExpr = dynamic_cast< OffsetofExpr* >( expr );
                        if ( ! offsetofExpr ) return expr;

                        // only mutate expressions for polymorphic structs/unions
                        Type *ty = isPolyType( offsetofExpr->get_type(), scopeTyVars );
                        if ( ! ty ) return offsetofExpr;

                        if ( StructInstType *structType = dynamic_cast< StructInstType* >( ty ) ) {
                                // replace offsetof expression by index into offset array
                                long i = findMember( offsetofExpr->get_member(), structType->get_baseStruct()->get_members() );
                                if ( i == -1 ) return offsetofExpr;

                                Expression *offsetInd = makeOffsetIndex( ty, i );
                                delete offsetofExpr;
                                return offsetInd;
                        } else if ( dynamic_cast< UnionInstType* >( ty ) ) {
                                // all union members are at offset zero
                                delete offsetofExpr;
                                return new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), std::string("0") ) );
                        } else return offsetofExpr;
                }

////////////////////////////////////////// Pass3 ////////////////////////////////////////////////////

                template< typename DeclClass >
                DeclClass * Pass3::handleDecl( DeclClass *decl, Type *type ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( type, scopeTyVars );

                        DeclClass *ret = static_cast< DeclClass *>( Mutator::mutate( decl ) );
                        ScrubTyVars::scrub( decl, scopeTyVars );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                ObjectDecl * Pass3::mutate( ObjectDecl *objectDecl ) {
                        return handleDecl( objectDecl, objectDecl->get_type() );
                }

                DeclarationWithType * Pass3::mutate( FunctionDecl *functionDecl ) {
                        return handleDecl( functionDecl, functionDecl->get_functionType() );
                }

                TypedefDecl * Pass3::mutate( TypedefDecl *typedefDecl ) {
                        return handleDecl( typedefDecl, typedefDecl->get_base() );
                }

                TypeDecl * Pass3::mutate( TypeDecl *typeDecl ) {
//   Initializer *init = 0;
//   std::list< Expression *> designators;
//   scopeTyVars[ typeDecl->get_name() ] = typeDecl->get_kind();
//   if ( typeDecl->get_base() ) {
//     init = new SimpleInit( new SizeofExpr( handleDecl( typeDecl, typeDecl->get_base() ) ), designators );
//   }
//   return new ObjectDecl( typeDecl->get_name(), Declaration::Extern, LinkageSpec::C, 0, new BasicType( Type::Qualifiers(), BasicType::UnsignedInt ), init );

                        scopeTyVars[ typeDecl->get_name() ] = typeDecl->get_kind();
                        return Mutator::mutate( typeDecl );
                }

                Type * Pass3::mutate( PointerType *pointerType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( pointerType, scopeTyVars );

                        Type *ret = Mutator::mutate( pointerType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }

                Type * Pass3::mutate( FunctionType *functionType ) {
                        TyVarMap oldtyVars = scopeTyVars;
                        makeTyVarMap( functionType, scopeTyVars );

                        Type *ret = Mutator::mutate( functionType );

                        scopeTyVars = oldtyVars;
                        return ret;
                }
        } // anonymous namespace
} // namespace GenPoly

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //