//
// 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.
//
// Autogen.cc --
//
// Author           : Rob Schluntz
// Created On       : Thu Mar 03 15:45:56 2016
// Last Modified By : Peter A. Buhr
// Last Modified On : Tue Jul 12 17:47:17 2016
// Update Count     : 2
//

#include <list>
#include <iterator>
#include "SynTree/Visitor.h"
#include "SynTree/Type.h"
#include "SynTree/Statement.h"
#include "SynTree/TypeSubstitution.h"
#include "Common/utility.h"
#include "AddVisit.h"
#include "MakeLibCfa.h"
#include "Autogen.h"

namespace SymTab {
	Type * SizeType = 0;

	class AutogenerateRoutines : public Visitor {
		public:
		std::list< Declaration * > &get_declsToAdd() { return declsToAdd; }

		virtual void visit( EnumDecl *enumDecl );
		virtual void visit( StructDecl *structDecl );
		virtual void visit( UnionDecl *structDecl );
		virtual void visit( TypeDecl *typeDecl );
		virtual void visit( TraitDecl *ctxDecl );
		virtual void visit( FunctionDecl *functionDecl );

		virtual void visit( FunctionType *ftype );
		virtual void visit( PointerType *ftype );

		virtual void visit( CompoundStmt *compoundStmt );
		virtual void visit( SwitchStmt *switchStmt );

		AutogenerateRoutines() : functionNesting( 0 ) {}
		private:
		template< typename StmtClass > void visitStatement( StmtClass *stmt );

		std::list< Declaration * > declsToAdd;
		std::set< std::string > structsDone;
		unsigned int functionNesting;     // current level of nested functions
	};

	void autogenerateRoutines( std::list< Declaration * > &translationUnit ) {
		AutogenerateRoutines visitor;
		acceptAndAdd( translationUnit, visitor, false );
	}

	bool isUnnamedBitfield( ObjectDecl * obj ) {
		return obj != NULL && obj->get_name() == "" && obj->get_bitfieldWidth() != NULL;
	}

	template< typename OutputIterator >
	void makeUnionFieldsAssignment( ObjectDecl *srcParam, ObjectDecl *dstParam, UnionInstType *unionType, OutputIterator out ) {
		UntypedExpr *copy = new UntypedExpr( new NameExpr( "__builtin_memcpy" ) );
		copy->get_args().push_back( new VariableExpr( dstParam ) );
		copy->get_args().push_back( new AddressExpr( new VariableExpr( srcParam ) ) );
		copy->get_args().push_back( new SizeofExpr( srcParam->get_type()->clone() ) );

		*out++ = new ExprStmt( noLabels, copy );
	}

	//E ?=?(E volatile*, int),
	//  ?=?(E _Atomic volatile*, int);
	void makeEnumFunctions( EnumDecl *enumDecl, EnumInstType *refType, unsigned int functionNesting, std::list< Declaration * > &declsToAdd ) {
		FunctionType *assignType = new FunctionType( Type::Qualifiers(), false );

		ObjectDecl *dstParam = new ObjectDecl( "_dst", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), refType ), 0 );
		assignType->get_parameters().push_back( dstParam );

		// void ?{}(E *); void ^?{}(E *);
		FunctionType * ctorType = assignType->clone();
		FunctionType * dtorType = assignType->clone();

		ObjectDecl *srcParam = new ObjectDecl( "_src", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, refType->clone(), 0 );
		assignType->get_parameters().push_back( srcParam );
		// void ?{}(E *, E);
		FunctionType *copyCtorType = assignType->clone();

		// T ?=?(E *, E);
		ObjectDecl *returnVal = new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, refType->clone(), 0 );
		assignType->get_returnVals().push_back( returnVal );

		// xxx - should we also generate void ?{}(E *, int) and E ?{}(E *, E)?
		// right now these cases work, but that might change.

		// Routines at global scope marked "static" to prevent multiple definitions is separate translation units
		// because each unit generates copies of the default routines for each aggregate.
		// xxx - Temporary: make these functions intrinsic so they codegen as C assignment.
		// Really they're something of a cross between instrinsic and autogen, so should
		// probably make a new linkage type
		FunctionDecl *assignDecl = new FunctionDecl( "?=?", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::Intrinsic, assignType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *ctorDecl = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::Intrinsic, ctorType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *copyCtorDecl = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::Intrinsic, copyCtorType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *dtorDecl = new FunctionDecl( "^?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::Intrinsic, dtorType, new CompoundStmt( noLabels ), true, false );
		assignDecl->fixUniqueId();
		ctorDecl->fixUniqueId();
		copyCtorDecl->fixUniqueId();
		dtorDecl->fixUniqueId();

		// enum copy construct and assignment is just C-style assignment.
		// this looks like a bad recursive call, but code gen will turn it into
		// a C-style assignment.
		// This happens before function pointer type conversion, so need to do it manually here
		VariableExpr * assignVarExpr = new VariableExpr( assignDecl );
		Type *& assignVarExprType = assignVarExpr->get_results().front();
		assignVarExprType = new PointerType( Type::Qualifiers(), assignVarExprType );
		ApplicationExpr * assignExpr = new ApplicationExpr( assignVarExpr );
		assignExpr->get_args().push_back( new VariableExpr( dstParam ) );
		assignExpr->get_args().push_back( new VariableExpr( srcParam ) );

		// body is either return stmt or expr stmt
		assignDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, assignExpr ) );
		copyCtorDecl->get_statements()->get_kids().push_back( new ExprStmt( noLabels, assignExpr->clone() ) );

		declsToAdd.push_back( assignDecl );
		declsToAdd.push_back( ctorDecl );
		declsToAdd.push_back( copyCtorDecl );
		declsToAdd.push_back( dtorDecl );
	}

	/// Clones a reference type, replacing any parameters it may have with a clone of the provided list
	template< typename GenericInstType >
	GenericInstType *cloneWithParams( GenericInstType *refType, const std::list< Expression* >& params ) {
		GenericInstType *clone = refType->clone();
		clone->get_parameters().clear();
		cloneAll( params, clone->get_parameters() );
		return clone;
	}

	/// Creates a new type decl that's the same as src, but renamed and with only the ?=?, ?{} (default and copy), and ^?{} assertions (for complete types only)
	TypeDecl *cloneAndRename( TypeDecl *src, const std::string &name ) {
		// TypeDecl *dst = new TypeDecl( name, src->get_storageClass(), 0, src->get_kind() );

		// if ( src->get_kind() == TypeDecl::Any ) {
		// 	TypeInstType *opParamType = new TypeInstType( Type::Qualifiers(), name, dst );
		// 	FunctionType *opFunctionType = new FunctionType( Type::Qualifiers(), false );
		// 	opFunctionType->get_parameters().push_back(
		// 		new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), opParamType->clone() ), 0 ) );
		// 	FunctionDecl *ctorAssert = new FunctionDecl( "?{}", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, opFunctionType->clone(), 0, false, false );
		// 	FunctionDecl *dtorAssert = new FunctionDecl( "^?{}", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, opFunctionType->clone(), 0, false, false );

		// 	opFunctionType->get_parameters().push_back(
		// 		new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, opParamType, 0 ) );
		// 	FunctionDecl *copyCtorAssert = new FunctionDecl( "?{}", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, opFunctionType->clone(), 0, false, false );

		// 	opFunctionType->get_returnVals().push_back(
		// 		new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, opParamType->clone(), 0 ) );
		// 	FunctionDecl *assignAssert = new FunctionDecl( "?=?", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, opFunctionType, 0, false, false );


		// 	dst->get_assertions().push_back( assignAssert );
		// 	dst->get_assertions().push_back( ctorAssert );
		// 	dst->get_assertions().push_back( dtorAssert );
		// 	dst->get_assertions().push_back( copyCtorAssert );
		// }

		TypeDecl *dst = new TypeDecl( src->get_name(), src->get_storageClass(), 0, src->get_kind() );
		cloneAll(src->get_assertions(), dst->get_assertions());
		return dst;
	}

	void makeStructMemberOp( ObjectDecl * dstParam, Expression * src, DeclarationWithType * field, FunctionDecl * func, TypeSubstitution & genericSubs, bool isDynamicLayout, bool forward = true ) {
// 		if ( isDynamicLayout && src ) {
// 			genericSubs.apply( src );
// 		}

		ObjectDecl * returnVal = NULL;
		if ( ! func->get_functionType()->get_returnVals().empty() ) {
			returnVal = dynamic_cast<ObjectDecl*>( func->get_functionType()->get_returnVals().front() );
		}

		InitTweak::InitExpander srcParam( src );

		// assign to destination (and return value if generic)
		UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
		derefExpr->get_args().push_back( new VariableExpr( dstParam ) );
		Expression *dstselect = new MemberExpr( field, derefExpr );
		genImplicitCall( srcParam, dstselect, func->get_name(), back_inserter( func->get_statements()->get_kids() ), field, forward );

		if ( isDynamicLayout && returnVal ) {
			UntypedExpr *derefRet = new UntypedExpr( new NameExpr( "*?" ) );
			derefRet->get_args().push_back( new VariableExpr( returnVal ) );
			Expression *retselect = new MemberExpr( field, derefRet );
			genImplicitCall( srcParam, retselect, func->get_name(), back_inserter( func->get_statements()->get_kids() ), field, forward );
		} // if
	}

	template<typename Iterator>
	void makeStructFunctionBody( Iterator member, Iterator end, FunctionDecl * func, TypeSubstitution & genericSubs, bool isDynamicLayout, bool forward = true ) {
		for ( ; member != end; ++member ) {
			if ( DeclarationWithType *field = dynamic_cast< DeclarationWithType * >( *member ) ) { // otherwise some form of type declaration, e.g. Aggregate
				// query the type qualifiers of this field and skip assigning it if it is marked const.
				// If it is an array type, we need to strip off the array layers to find its qualifiers.
				Type * type = field->get_type();
				while ( ArrayType * at = dynamic_cast< ArrayType * >( type ) ) {
					type = at->get_base();
				}

				if ( type->get_qualifiers().isConst && func->get_name() == "?=?" ) {
					// don't assign const members, but do construct/destruct
					continue;
				}

				if ( field->get_name() == "" ) {
					// don't assign to anonymous members
					// xxx - this is a temporary fix. Anonymous members tie into
					// our inheritance model. I think the correct way to handle this is to
					// cast the structure to the type of the member and let the resolver
					// figure out whether it's valid and have a pass afterwards that fixes
					// the assignment to use pointer arithmetic with the offset of the
					// member, much like how generic type members are handled.
					continue;
				}

				assert( ! func->get_functionType()->get_parameters().empty() );
				ObjectDecl * dstParam = dynamic_cast<ObjectDecl*>( func->get_functionType()->get_parameters().front() );
				ObjectDecl * srcParam = NULL;
				if ( func->get_functionType()->get_parameters().size() == 2 ) {
					srcParam = dynamic_cast<ObjectDecl*>( func->get_functionType()->get_parameters().back() );
				}
				// srcParam may be NULL, in which case we have default ctor/dtor
				assert( dstParam );

				Expression *srcselect = srcParam ? new MemberExpr( field, new VariableExpr( srcParam ) ) : NULL;
				makeStructMemberOp( dstParam, srcselect, field, func, genericSubs, isDynamicLayout, forward );
			} // if
		} // for
	} // makeStructFunctionBody

	/// generate the body of a constructor which takes parameters that match fields, e.g.
	/// void ?{}(A *, int) and void?{}(A *, int, int) for a struct A which has two int fields.
	template<typename Iterator>
	void makeStructFieldCtorBody( Iterator member, Iterator end, FunctionDecl * func, TypeSubstitution & genericSubs, bool isDynamicLayout ) {
		FunctionType * ftype = func->get_functionType();
		std::list<DeclarationWithType*> & params = ftype->get_parameters();
		assert( params.size() >= 2 );  // should not call this function for default ctor, etc.

		// skip 'this' parameter
		ObjectDecl * dstParam = dynamic_cast<ObjectDecl*>( params.front() );
		assert( dstParam );
		std::list<DeclarationWithType*>::iterator parameter = params.begin()+1;
		for ( ; member != end; ++member ) {
			if ( DeclarationWithType * field = dynamic_cast<DeclarationWithType*>( *member ) ) {
				if ( isUnnamedBitfield( dynamic_cast< ObjectDecl * > ( field ) ) ) {
					// don't make a function whose parameter is an unnamed bitfield
					continue;
				} else if ( field->get_name() == "" ) {
					// don't assign to anonymous members
					// xxx - this is a temporary fix. Anonymous members tie into
					// our inheritance model. I think the correct way to handle this is to
					// cast the structure to the type of the member and let the resolver
					// figure out whether it's valid and have a pass afterwards that fixes
					// the assignment to use pointer arithmetic with the offset of the
					// member, much like how generic type members are handled.
					continue;
				} else if ( parameter != params.end() ) {
					// matching parameter, initialize field with copy ctor
					Expression *srcselect = new VariableExpr(*parameter);
					makeStructMemberOp( dstParam, srcselect, field, func, genericSubs, isDynamicLayout );
					++parameter;
				} else {
					// no matching parameter, initialize field with default ctor
					makeStructMemberOp( dstParam, NULL, field, func, genericSubs, isDynamicLayout );
				}
			}
		}
	}

	void makeStructFunctions( StructDecl *aggregateDecl, StructInstType *refType, unsigned int functionNesting, std::list< Declaration * > & declsToAdd ) {
		FunctionType *assignType = new FunctionType( Type::Qualifiers(), false );

		// Make function polymorphic in same parameters as generic struct, if applicable
		bool isDynamicLayout = false;  // NOTE this flag is an incredibly ugly kludge; we should fix the assignment signature instead (ditto for union)
		std::list< TypeDecl* >& genericParams = aggregateDecl->get_parameters();
		std::list< Expression* > structParams;  // List of matching parameters to put on types
		TypeSubstitution genericSubs; // Substitutions to make to member types of struct
		for ( std::list< TypeDecl* >::const_iterator param = genericParams.begin(); param != genericParams.end(); ++param ) {
			if ( (*param)->get_kind() == TypeDecl::Any ) isDynamicLayout = true;
			TypeDecl *typeParam = cloneAndRename( *param, "_autoassign_" + aggregateDecl->get_name() + "_" + (*param)->get_name() );
			assignType->get_forall().push_back( typeParam );
			TypeInstType *newParamType = new TypeInstType( Type::Qualifiers(), typeParam->get_name(), typeParam );
			genericSubs.add( (*param)->get_name(), newParamType );
			structParams.push_back( new TypeExpr( newParamType ) );
		}

		ObjectDecl *dstParam = new ObjectDecl( "_dst", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), cloneWithParams( refType, structParams ) ), 0 );
		assignType->get_parameters().push_back( dstParam );

		// void ?{}(T *); void ^?{}(T *);
		FunctionType *ctorType = assignType->clone();
		FunctionType *dtorType = assignType->clone();

		ObjectDecl *srcParam = new ObjectDecl( "_src", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, cloneWithParams( refType, structParams ), 0 );
		assignType->get_parameters().push_back( srcParam );

		// void ?{}(T *, T);
		FunctionType *copyCtorType = assignType->clone();

		// T ?=?(T *, T);
		ObjectDecl *returnVal = new ObjectDecl( "_ret", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, cloneWithParams( refType, structParams ), 0 );
		assignType->get_returnVals().push_back( returnVal );

		// Routines at global scope marked "static" to prevent multiple definitions is separate translation units
		// because each unit generates copies of the default routines for each aggregate.
		FunctionDecl *assignDecl = new FunctionDecl( "?=?", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, assignType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *ctorDecl = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, ctorType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *copyCtorDecl = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, copyCtorType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *dtorDecl = new FunctionDecl( "^?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, dtorType, new CompoundStmt( noLabels ), true, false );
		assignDecl->fixUniqueId();
		ctorDecl->fixUniqueId();
		copyCtorDecl->fixUniqueId();
		dtorDecl->fixUniqueId();

		// create constructors which take each member type as a parameter.
		// for example, for struct A { int x, y; }; generate
		// void ?{}(A *, int) and void ?{}(A *, int, int)
		std::list<Declaration *> memCtors;
		FunctionType * memCtorType = ctorType->clone();
		for ( std::list<Declaration *>::iterator i = aggregateDecl->get_members().begin(); i != aggregateDecl->get_members().end(); ++i ) {
			DeclarationWithType * member = dynamic_cast<DeclarationWithType *>( *i );
			assert( member );
			if ( isUnnamedBitfield( dynamic_cast< ObjectDecl * > ( member ) ) ) {
				// don't make a function whose parameter is an unnamed bitfield
				continue;
			} else if ( member->get_name() == "" ) {
				// don't assign to anonymous members
				// xxx - this is a temporary fix. Anonymous members tie into
				// our inheritance model. I think the correct way to handle this is to
				// cast the structure to the type of the member and let the resolver
				// figure out whether it's valid and have a pass afterwards that fixes
				// the assignment to use pointer arithmetic with the offset of the
				// member, much like how generic type members are handled.
				continue;
			}
			memCtorType->get_parameters().push_back( new ObjectDecl( member->get_name(), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, member->get_type()->clone(), 0 ) );
			FunctionDecl * ctor = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, memCtorType->clone(), new CompoundStmt( noLabels ), true, false );
			ctor->fixUniqueId();
			makeStructFieldCtorBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), ctor, genericSubs, isDynamicLayout );
			memCtors.push_back( ctor );
		}
		delete memCtorType;

		// generate appropriate calls to member ctor, assignment
		makeStructFunctionBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), assignDecl, genericSubs, isDynamicLayout );
		makeStructFunctionBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), ctorDecl, genericSubs, isDynamicLayout );
		makeStructFunctionBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), copyCtorDecl, genericSubs, isDynamicLayout );
		// needs to do everything in reverse, so pass "forward" as false
		makeStructFunctionBody( aggregateDecl->get_members().rbegin(), aggregateDecl->get_members().rend(), dtorDecl, genericSubs, isDynamicLayout, false );

		if ( ! isDynamicLayout ) assignDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );

		declsToAdd.push_back( assignDecl );
		declsToAdd.push_back( ctorDecl );
		declsToAdd.push_back( copyCtorDecl );
		declsToAdd.push_back( dtorDecl );
		declsToAdd.splice( declsToAdd.end(), memCtors );
	}

	void makeUnionFunctions( UnionDecl *aggregateDecl, UnionInstType *refType, unsigned int functionNesting, std::list< Declaration * > & declsToAdd ) {
		FunctionType *assignType = new FunctionType( Type::Qualifiers(), false );

		// Make function polymorphic in same parameters as generic union, if applicable
		bool isDynamicLayout = false; // NOTE this flag is an incredibly ugly kludge; we should fix the assignment signature instead (ditto for struct)
		std::list< TypeDecl* >& genericParams = aggregateDecl->get_parameters();
		std::list< Expression* > unionParams;  // List of matching parameters to put on types
		for ( std::list< TypeDecl* >::const_iterator param = genericParams.begin(); param != genericParams.end(); ++param ) {
			if ( (*param)->get_kind() == TypeDecl::Any ) isDynamicLayout = true;
			TypeDecl *typeParam = cloneAndRename( *param, "_autoassign_" + aggregateDecl->get_name() + "_" + (*param)->get_name() );
			assignType->get_forall().push_back( typeParam );
			unionParams.push_back( new TypeExpr( new TypeInstType( Type::Qualifiers(), typeParam->get_name(), typeParam ) ) );
		}

		ObjectDecl *dstParam = new ObjectDecl( "_dst", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), cloneWithParams( refType, unionParams ) ), 0 );
		assignType->get_parameters().push_back( dstParam );

		// default ctor/dtor need only first parameter
		FunctionType * ctorType = assignType->clone();
		FunctionType * dtorType = assignType->clone();

		ObjectDecl *srcParam = new ObjectDecl( "_src", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, cloneWithParams( refType, unionParams ), 0 );
		assignType->get_parameters().push_back( srcParam );

		// copy ctor needs both parameters
		FunctionType * copyCtorType = assignType->clone();

		// assignment needs both and return value
		ObjectDecl *returnVal = new ObjectDecl( "_ret", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, cloneWithParams( refType, unionParams ), 0 );
		assignType->get_returnVals().push_back( returnVal );

		// Routines at global scope marked "static" to prevent multiple definitions is separate translation units
		// because each unit generates copies of the default routines for each aggregate.
		FunctionDecl *assignDecl = new FunctionDecl( "?=?",  functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, assignType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *ctorDecl = new FunctionDecl( "?{}",  functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, ctorType, new CompoundStmt( noLabels ), true, false );
		FunctionDecl *copyCtorDecl = new FunctionDecl( "?{}",  functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, copyCtorType, NULL, true, false );
		FunctionDecl *dtorDecl = new FunctionDecl( "^?{}",  functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, dtorType, new CompoundStmt( noLabels ), true, false );

		assignDecl->fixUniqueId();
		ctorDecl->fixUniqueId();
		copyCtorDecl->fixUniqueId();
		dtorDecl->fixUniqueId();

		makeUnionFieldsAssignment( srcParam, dstParam, cloneWithParams( refType, unionParams ), back_inserter( assignDecl->get_statements()->get_kids() ) );
		if ( isDynamicLayout ) makeUnionFieldsAssignment( srcParam, returnVal, cloneWithParams( refType, unionParams ), back_inserter( assignDecl->get_statements()->get_kids() ) );
		else assignDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );

		// body of assignment and copy ctor is the same
		copyCtorDecl->set_statements( assignDecl->get_statements()->clone() );

		// create a constructor which takes the first member type as a parameter.
		// for example, for Union A { int x; double y; }; generate
		// void ?{}(A *, int)
		// This is to mimic C's behaviour which initializes the first member of the union.
		std::list<Declaration *> memCtors;
		for ( Declaration * member : aggregateDecl->get_members() ) {
			if ( DeclarationWithType * field = dynamic_cast< DeclarationWithType * >( member ) ) {
				ObjectDecl * srcParam = new ObjectDecl( "src", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, field->get_type()->clone(), 0 );

				FunctionType * memCtorType = ctorType->clone();
				memCtorType->get_parameters().push_back( srcParam );
				FunctionDecl * ctor = new FunctionDecl( "?{}", functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static, LinkageSpec::AutoGen, memCtorType, new CompoundStmt( noLabels ), true, false );
				ctor->fixUniqueId();

				makeUnionFieldsAssignment( srcParam, dstParam, cloneWithParams( refType, unionParams ), back_inserter( ctor->get_statements()->get_kids() ) );
				memCtors.push_back( ctor );
				// only generate a ctor for the first field
				break;
			}
		}

		declsToAdd.push_back( assignDecl );
		declsToAdd.push_back( ctorDecl );
		declsToAdd.push_back( copyCtorDecl );
		declsToAdd.push_back( dtorDecl );
		declsToAdd.splice( declsToAdd.end(), memCtors );
	}

	void AutogenerateRoutines::visit( EnumDecl *enumDecl ) {
		if ( ! enumDecl->get_members().empty() ) {
			EnumInstType *enumInst = new EnumInstType( Type::Qualifiers(), enumDecl->get_name() );
			// enumInst->set_baseEnum( enumDecl );
			// declsToAdd.push_back(
			makeEnumFunctions( enumDecl, enumInst, functionNesting, declsToAdd );
		}
	}

	void AutogenerateRoutines::visit( StructDecl *structDecl ) {
		if ( ! structDecl->get_members().empty() && structsDone.find( structDecl->get_name() ) == structsDone.end() ) {
			StructInstType structInst( Type::Qualifiers(), structDecl->get_name() );
			structInst.set_baseStruct( structDecl );
			makeStructFunctions( structDecl, &structInst, functionNesting, declsToAdd );
			structsDone.insert( structDecl->get_name() );
		} // if
	}

	void AutogenerateRoutines::visit( UnionDecl *unionDecl ) {
		if ( ! unionDecl->get_members().empty() ) {
			UnionInstType unionInst( Type::Qualifiers(), unionDecl->get_name() );
			unionInst.set_baseUnion( unionDecl );
			makeUnionFunctions( unionDecl, &unionInst, functionNesting, declsToAdd );
		} // if
	}

	void AutogenerateRoutines::visit( TypeDecl *typeDecl ) {
		CompoundStmt *stmts = 0;
		TypeInstType *typeInst = new TypeInstType( Type::Qualifiers(), typeDecl->get_name(), false );
		typeInst->set_baseType( typeDecl );
		ObjectDecl *src = new ObjectDecl( "_src", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, typeInst->clone(), 0 );
		ObjectDecl *dst = new ObjectDecl( "_dst", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), typeInst->clone() ), 0 );
		if ( typeDecl->get_base() ) {
			// xxx - generate ctor/dtors for typedecls, e.g.
			// otype T = int *;
			stmts = new CompoundStmt( std::list< Label >() );
			UntypedExpr *assign = new UntypedExpr( new NameExpr( "?=?" ) );
			assign->get_args().push_back( new CastExpr( new VariableExpr( dst ), new PointerType( Type::Qualifiers(), typeDecl->get_base()->clone() ) ) );
			assign->get_args().push_back( new CastExpr( new VariableExpr( src ), typeDecl->get_base()->clone() ) );
			stmts->get_kids().push_back( new ReturnStmt( std::list< Label >(), assign ) );
		} // if
		FunctionType *type = new FunctionType( Type::Qualifiers(), false );
		type->get_returnVals().push_back( new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::Cforall, 0, typeInst, 0 ) );
		type->get_parameters().push_back( dst );
		type->get_parameters().push_back( src );
		FunctionDecl *func = new FunctionDecl( "?=?", DeclarationNode::NoStorageClass, LinkageSpec::AutoGen, type, stmts, true, false );
		declsToAdd.push_back( func );
	}

	void addDecls( std::list< Declaration * > &declsToAdd, std::list< Statement * > &statements, std::list< Statement * >::iterator i ) {
		for ( std::list< Declaration * >::iterator decl = declsToAdd.begin(); decl != declsToAdd.end(); ++decl ) {
			statements.insert( i, new DeclStmt( noLabels, *decl ) );
		} // for
		declsToAdd.clear();
	}

	void AutogenerateRoutines::visit( FunctionType *) {
		// ensure that we don't add assignment ops for types defined as part of the function
	}

	void AutogenerateRoutines::visit( PointerType *) {
		// ensure that we don't add assignment ops for types defined as part of the pointer
	}

	void AutogenerateRoutines::visit( TraitDecl *) {
		// ensure that we don't add assignment ops for types defined as part of the trait
	}

	template< typename StmtClass >
	inline void AutogenerateRoutines::visitStatement( StmtClass *stmt ) {
		std::set< std::string > oldStructs = structsDone;
		addVisit( stmt, *this );
		structsDone = oldStructs;
	}

	void AutogenerateRoutines::visit( FunctionDecl *functionDecl ) {
		maybeAccept( functionDecl->get_functionType(), *this );
		acceptAll( functionDecl->get_oldDecls(), *this );
		functionNesting += 1;
		maybeAccept( functionDecl->get_statements(), *this );
		functionNesting -= 1;
	}

	void AutogenerateRoutines::visit( CompoundStmt *compoundStmt ) {
		visitStatement( compoundStmt );
	}

	void AutogenerateRoutines::visit( SwitchStmt *switchStmt ) {
		visitStatement( switchStmt );
	}
} // SymTab