source: src/GenPoly/Box.cc @ 567bb17

//
// 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 : Rob Schluntz
// Last Modified On : Fri Dec 18 14:53:08 2015
// Update Count     : 217
//

#include <set>
#include <stack>
#include <string>
#include <iterator>
#include <algorithm>
#include <cassert>

#include "Box.h"
#include "InstantiateGeneric.h"
#include "PolyMutator.h"
#include "FindFunction.h"
#include "ScopedMap.h"
#include "ScrubTyVars.h"

#include "Parser/ParseNode.h"

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

#include "ResolvExpr/TypeEnvironment.h"

#include "SymTab/Mangler.h"

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

#include <ext/functional> // temporary

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

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

                /// 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:
                        /// Makes a new temporary array holding the offsets of the fields of `type`, and returns a new variable expression referencing it
                        Expression *makeOffsetArray( StructInstType *type );
                        /// passes extra type parameters into a polymorphic function application
                        void passTypeVars( ApplicationExpr *appExpr, 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 );

                        typedef std::map< std::string, DeclarationWithType *> AdapterMap;
                        std::map< std::string, DeclarationWithType *> assignOps;
                        ScopedMap< std::string, DeclarationWithType *> scopedAssignOps;
                        std::stack< AdapterMap > adapters;
                        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 as well
                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 );
                  private:
                        void addAdapters( FunctionType *functionType );

                        std::map< UniqueId, std::string > adapterName;
                };

                /// Replaces member expressions for polymorphic types with calculated add-field-offset-and-dereference
                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 );
                };
                
                /// 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

        void printAllNotBuiltin( const std::list< Declaration *>& translationUnit, std::ostream &os ) {
                for ( std::list< Declaration *>::const_iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
                        if ( ! LinkageSpec::isBuiltin( (*i)->get_linkage() ) ) {
                                (*i)->print( os );
                                os << std::endl;
                        } // if
                } // for
        }

        /// 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 ) {
                Pass1 pass1;
                Pass2 pass2;
                MemberExprFixer memberFixer;
                Pass3 pass3;
                mutateTranslationUnit/*All*/( translationUnit, pass1 );
                mutateTranslationUnit/*All*/( translationUnit, pass2 );
                instantiateGeneric( translationUnit );
                mutateTranslationUnit/*All*/( translationUnit, memberFixer );
                mutateTranslationUnit/*All*/( translationUnit, pass3 );
        }

        ////////////////////////////////////////// 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" ) {
                        adapters.push(AdapterMap());
                }

                /// returns T if the given declaration is: (*?=?)(T *, T) for some T (return not checked, but maybe should be), NULL otherwise
                ReferenceToType *isAssignment( 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 ( ReferenceToType *refType = dynamic_cast< ReferenceToType *>( pointer->get_base() ) ) {
                                                                if ( ReferenceToType *refType2 = dynamic_cast< ReferenceToType *>( funType->get_parameters().back()->get_type() ) ) {
                                                                        if ( refType->get_name() == refType2->get_name() ) {
                                                                                return refType;
                                                                        } // if
                                                                } // if
                                                        } // 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 = dynamic_cast< TypeInstType* >( isAssignment( *assert ) ) ) {
                                                assignOps[ typeInst->get_name() ] = *assert;
                                        } // if
                                } // for
                        } // for
                }

                DeclarationWithType *Pass1::mutate( FunctionDecl *functionDecl ) {
                        // if this is a polymorphic assignment function, put it in the map for this scope
                        if ( ReferenceToType *refType = isAssignment( functionDecl ) ) {
                                if ( ! dynamic_cast< TypeInstType* >( refType ) ) {
                                        scopedAssignOps.insert( refType->get_name(), 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
                                
                                AdapterMap & adapters = Pass1::adapters.top();
                                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;

                }

                Expression *Pass1::makeOffsetArray( StructInstType *ty ) {
                        // make a new temporary array
                        Type *offsetType = new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt );
                        ObjectDecl *arrayTemp = makeTemporary( new PointerType( Type::Qualifiers(), offsetType ) );

                        // build initializer list for temporary
                        std::list< Initializer* > inits;
                        StructDecl *tyBase = ty->get_baseStruct();
                        for ( std::list< Declaration* >::const_iterator member = tyBase->get_members().begin(); member != tyBase->get_members().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 ) ) );
                        }
                        arrayTemp->set_init( new ListInit( inits ) );

                        // return variable pointing to temporary
                        return new VariableExpr( arrayTemp );
                }
                
                void Pass1::passTypeVars( ApplicationExpr *appExpr, 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
                        for ( ; fnParm != funcType->get_parameters().end() && fnArg != appExpr->get_args().end(); ++fnParm, ++fnArg ) {
                                Type *parmType = (*fnParm)->get_type();
                                if ( ! dynamic_cast< TypeInstType* >( parmType ) && isPolyType( parmType, exprTyVars ) ) {
                                        std::string sizeName = sizeofName( parmType );
                                        if ( seenTypes.count( sizeName ) ) continue;

                                        assert( ! (*fnArg)->get_results().empty() );
                                        Type *argType = (*fnArg)->get_results().front();
                                        arg = appExpr->get_args().insert( arg, new SizeofExpr( argType->clone() ) );
                                        arg++;
                                        arg = appExpr->get_args().insert( arg, new AlignofExpr( argType->clone() ) );
                                        arg++;
                                        if ( dynamic_cast< StructInstType* >( parmType ) ) {
                                                if ( StructInstType *argStructType = dynamic_cast< StructInstType* >( argType ) ) {
                                                        arg = appExpr->get_args().insert( arg, makeOffsetArray( argStructType ) );
                                                        arg++;
                                                } else {
                                                        throw SemanticError( "Cannot pass non-struct type for generic struct" );
                                                }
                                        }

                                        seenTypes.insert( sizeName );
                                }
                        }
                }

                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 );
                        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 );

                        appExpr->get_args().push_front( appExpr->get_function() );
                        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 ( dynamic_cast< TypeInstType *>( arg->get_results().front() ) ) {
                                        // if the argument's type is a type parameter, 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 {
                                        ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, arg->get_results().front()->clone(), 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
                }

                void addCast( Expression *&actual, Type *formal, const TyVarMap &tyVars ) {
                        Type *newType = formal->clone();
                        std::list< FunctionType *> functions;
                        // instead of functions needing adapters, this really ought to look for
                        // any function mentioning a polymorphic type
                        findAndReplaceFunction( newType, functions, tyVars, needsAdapter );
                        if ( ! functions.empty() ) {
                                actual = new CastExpr( actual, newType );
                        } else {
                                delete 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 ( dynamic_cast<TypeInstType *>(arg->get_type()) == NULL ) {
                                        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 );

                                        AdapterMap & adapters = Pass1::adapters.top();
                                        AdapterMap::iterator 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 );
                                                adapter = adapters.insert( adapters.begin(), std::pair< std::string, DeclarationWithType *>( mangleName, newAdapter ) );
                                                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();

                        if ( ReferenceToType *polyType = isPolyRet( function ) ) {
                                ret = addPolyRetParam( appExpr, function, polyType, 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();

                        TyVarMap exprTyVars;
                        makeTyVarMap( function, exprTyVars );

                        passTypeVars( appExpr, 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
                }

                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
                                DeclarationWithType *assignDecl = 0;
                                if ( TypeInstType *typeInst = dynamic_cast< TypeInstType *>( retval->get_type() ) ) {
                                        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
                                        assignDecl = assignIter->second;
                                } else if ( ReferenceToType *refType = dynamic_cast< ReferenceToType *>( retval->get_type() ) ) {
                                        ScopedMap< std::string, DeclarationWithType *>::const_iterator assignIter = scopedAssignOps.find( refType->get_name() );
                                        if ( assignIter == scopedAssignOps.end() ) {
                                                throw SemanticError( "Attempt to return dtype or ftype generic object in ", returnStmt->get_expr() );
                                        }
                                        DeclarationWithType *functionDecl = assignIter->second;
                                        // line below cloned from FixFunction.cc
                                        assignDecl = new ObjectDecl( functionDecl->get_name(), functionDecl->get_storageClass(), functionDecl->get_linkage(), 0,
                                                                     new PointerType( Type::Qualifiers(), functionDecl->get_type()->clone() ), 0 );
                                        assignDecl->set_mangleName( functionDecl->get_mangleName() );
                                }
                                assert( assignDecl );

                                // replace return statement with appropriate assignment to out parameter
                                ApplicationExpr *assignExpr = new ApplicationExpr( new VariableExpr( assignDecl ) );
                                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() {
                        // push a copy of the current map
                        adapters.push(adapters.top());
                        scopedAssignOps.beginScope();
                }

                void Pass1::doEndScope() {
                        adapters.pop();
                        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 );
//   ObjectDecl *newFunPtr = new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), new FunctionType( Type::Qualifiers(), true ) ), 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 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 *parmType = (*fnParm)->get_type();
                                if ( ! dynamic_cast< TypeInstType* >( parmType ) && isPolyType( parmType, scopeTyVars ) ) {
                                        std::string sizeName = sizeofName( parmType );
                                        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( parmType ) );
                                        last = funcType->get_parameters().insert( last, alignParm );
                                        ++last;

                                        if ( dynamic_cast< StructInstType* >( parmType ) ) {
                                                offsetParm = newPtr.clone();
                                                offsetParm->set_name( offsetofName( parmType ) );
                                                last = funcType->get_parameters().insert( last, offsetParm );
                                                ++last;
                                        }

                                        seenTypes.insert( sizeName );
                                }
                        }

                        // 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;
                }

////////////////////////////////////////// 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 );
                }

                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
                        VariableExpr *varExpr = getBaseVar( memberExpr->get_aggregate() );
                        if ( ! varExpr ) return memberExpr;
                        ObjectDecl *objectDecl = dynamic_cast< ObjectDecl* >( varExpr->get_var() );
                        if ( ! objectDecl ) return memberExpr;

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

                        // get base aggregate for type so members can be looked up
                        AggregateDecl *memberBase = 0;
                        if ( StructInstType *structType = dynamic_cast< StructInstType* >( objectType ) ) {
                                memberBase = structType->get_baseStruct();
                        } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( objectType ) ) {
                                memberBase = unionType->get_baseUnion();
                        } else return memberExpr;

                        // look up numeric index of member in base aggregate
                        DeclarationWithType *memberDecl = memberExpr->get_member();
                        std::list< Declaration* > &baseDecls = memberBase->get_members();
                        std::list< Declaration* >::const_iterator decl = baseDecls.begin();
                        unsigned long i = 0;
                        for( ; decl != baseDecls.end(); ++decl, ++i ) {
                                if ( memberDecl->get_name() != (*decl)->get_name() ) continue;

                                if ( DeclarationWithType *declWithType = dynamic_cast< DeclarationWithType* >( *decl ) ) {
                                        if ( memberDecl->get_mangleName() == declWithType->get_mangleName() ) break;
                                        else continue;
                                } else break;
                        }
                        if ( decl == baseDecls.end() ) return memberExpr;

                        // replace member expression with pointer to base plus offset
                        // this is in a polymorphic context, so maybe keeping it as a void* is fine?
                        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 );
                        UntypedExpr *fieldLoc = new UntypedExpr( new NameExpr( "?+?" ) );
                        fieldLoc->get_args().push_back( memberExpr->get_aggregate() );
                        fieldLoc->get_args().push_back( fieldOffset );

                        memberExpr->set_aggregate( 0 );
                        delete memberExpr;
                        return fieldLoc;
                }

////////////////////////////////////////// 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: //