//
// 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 : Andrew Beach
// Last Modified On : Wed Jun 28 15:30:00 2017
// Update Count     : 61
//

#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"
#include "GenPoly/ScopedSet.h"
#include "Common/ScopedMap.h"
#include "SymTab/Mangler.h"
#include "GenPoly/DeclMutator.h"

namespace SymTab {
	Type * SizeType = 0;
	typedef ScopedMap< std::string, bool > TypeMap;

	/// Data used to generate functions generically. Specifically, the name of the generated function, a function which generates the routine protoype, and a map which contains data to determine whether a function should be generated.
	struct FuncData {
		typedef FunctionType * (*TypeGen)( Type * );
		FuncData( const std::string & fname, const TypeGen & genType, TypeMap & map ) : fname( fname ), genType( genType ), map( map ) {}
		std::string fname;
		TypeGen genType;
		TypeMap & map;
	};

	class AutogenerateRoutines final : public Visitor {
	    template< typename Visitor >
	    friend void acceptAndAdd( std::list< Declaration * > &translationUnit, Visitor &visitor );
	    template< typename Visitor >
	    friend void addVisitStatementList( std::list< Statement* > &stmts, Visitor &visitor );
	  public:
		std::list< Declaration * > &get_declsToAdd() { return declsToAdd; }

		typedef Visitor Parent;
		using Parent::visit;

		AutogenerateRoutines();

		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 );

	  private:
		template< typename StmtClass > void visitStatement( StmtClass *stmt );

		std::list< Declaration * > declsToAdd, declsToAddAfter;
		std::set< std::string > structsDone;
		unsigned int functionNesting = 0;     // current level of nested functions
		/// Note: the following maps could be ScopedSets, but it should be easier to work
		/// deleted functions in if they are maps, since the value false can be inserted
		/// at the current scope without affecting outer scopes or requiring copies.
		TypeMap copyable, assignable, constructable, destructable;
		std::vector< FuncData > data;
	};

	/// generates routines for tuple types.
	/// Doesn't really need to be a mutator, but it's easier to reuse DeclMutator than it is to use AddVisit
	/// or anything we currently have that supports adding new declarations for visitors
	class AutogenTupleRoutines : public GenPoly::DeclMutator {
	  public:
		typedef GenPoly::DeclMutator Parent;
		using Parent::mutate;

		virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );

		virtual Type * mutate( TupleType *tupleType );

		virtual CompoundStmt * mutate( CompoundStmt *compoundStmt );

	  private:
		unsigned int functionNesting = 0;     // current level of nested functions
		GenPoly::ScopedSet< std::string > seenTuples;
	};

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

		// needs to be done separately because AutogenerateRoutines skips types that appear as function arguments, etc.
		// AutogenTupleRoutines tupleGenerator;
		// tupleGenerator.mutateDeclarationList( translationUnit );
	}

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

	/// inserts a forward declaration for functionDecl into declsToAdd
	void addForwardDecl( FunctionDecl * functionDecl, std::list< Declaration * > & declsToAdd ) {
		FunctionDecl * decl = functionDecl->clone();
		delete decl->get_statements();
		decl->set_statements( NULL );
		declsToAdd.push_back( decl );
		decl->fixUniqueId();
	}

	/// given type T, generate type of default ctor/dtor, i.e. function type void (*) (T *)
	FunctionType * genDefaultType( Type * paramType ) {
		FunctionType *ftype = new FunctionType( Type::Qualifiers(), false );
		ObjectDecl *dstParam = new ObjectDecl( "_dst", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, new PointerType( Type::Qualifiers(), paramType->clone() ), nullptr );
		ftype->get_parameters().push_back( dstParam );

		return ftype;
	}

	/// given type T, generate type of copy ctor, i.e. function type void (*) (T *, T)
	FunctionType * genCopyType( Type * paramType ) {
		FunctionType *ftype = genDefaultType( paramType );
		ObjectDecl *srcParam = new ObjectDecl( "_src", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, paramType->clone(), nullptr );
		ftype->get_parameters().push_back( srcParam );
		return ftype;
	}

	/// given type T, generate type of assignment, i.e. function type T (*) (T *, T)
	FunctionType * genAssignType( Type * paramType ) {
		FunctionType *ftype = genCopyType( paramType );
		ObjectDecl *returnVal = new ObjectDecl( "_ret", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, paramType->clone(), nullptr );
		ftype->get_returnVals().push_back( returnVal );
		return ftype;
	}

	/// true if the aggregate's layout is dynamic
	template< typename AggrDecl >
	bool hasDynamicLayout( AggrDecl * aggregateDecl ) {
		for ( TypeDecl * param : aggregateDecl->get_parameters() ) {
			if ( param->isComplete() ) return true;
		}
		return false;
	}

	/// generate a function decl from a name and type. Nesting depth determines whether
	/// the declaration is static or not; optional paramter determines if declaration is intrinsic
	FunctionDecl * genFunc( const std::string & fname, FunctionType * ftype, unsigned int functionNesting, bool isIntrinsic = false  ) {
		// Routines at global scope marked "static" to prevent multiple definitions in separate translation units
		// because each unit generates copies of the default routines for each aggregate.
//		DeclarationNode::StorageClass sc = functionNesting > 0 ? DeclarationNode::NoStorageClass : DeclarationNode::Static;
		Type::StorageClasses scs = functionNesting > 0 ? Type::StorageClasses() : Type::StorageClasses( Type::Static );
		LinkageSpec::Spec spec = isIntrinsic ? LinkageSpec::Intrinsic : LinkageSpec::AutoGen;
		FunctionDecl * decl = new FunctionDecl( fname, scs, spec, ftype, new CompoundStmt( noLabels ),
												std::list< Attribute * >(), Type::FuncSpecifiers( Type::Inline ) );
		decl->fixUniqueId();
		return decl;
	}

	/// inserts base type of first argument into map if pred(funcDecl) is true
	void insert( FunctionDecl *funcDecl, TypeMap & map, FunctionDecl * (*pred)(Declaration *) ) {
		// insert type into constructable, etc. map if appropriate
		if ( pred( funcDecl ) ) {
			FunctionType * ftype = funcDecl->get_functionType();
			assert( ! ftype->get_parameters().empty() );
			Type * t = safe_dynamic_cast< PointerType * >( ftype->get_parameters().front()->get_type() )->get_base();
			map.insert( Mangler::mangleType( t ), true );
		}
	}

	/// using map and t, determines if is constructable, etc.
	bool lookup( const TypeMap & map, Type * t ) {
		if ( dynamic_cast< PointerType * >( t ) ) {
			// will need more complicated checking if we want this to work with pointer types, since currently
			return true;
		} else if ( ArrayType * at = dynamic_cast< ArrayType * >( t ) ) {
			// an array's constructor, etc. is generated on the fly based on the base type's constructor, etc.
			return lookup( map, at->get_base() );
		}
		TypeMap::const_iterator it = map.find( Mangler::mangleType( t ) );
		if ( it != map.end() ) return it->second;
		// something that does not appear in the map is by default not constructable, etc.
		return false;
	}

	/// using map and aggr, examines each member to determine if constructor, etc. should be generated
	template<typename AggrDecl>
	bool shouldGenerate( const TypeMap & map, AggrDecl * aggr ) {
		for ( Declaration * dcl : aggr->get_members() ) {
			if ( DeclarationWithType * dwt = dynamic_cast< DeclarationWithType * >( dcl ) ) {
				if ( ! lookup( map, dwt->get_type() ) ) return false;
			}
		}
		return true;
	}

	/// data structure for abstracting the generation of special functions
	template< typename OutputIterator >
	struct FuncGenerator {
		StructDecl *aggregateDecl;
		StructInstType *refType;
		unsigned int functionNesting;
		const std::list< TypeDecl* > & typeParams;
		OutputIterator out;
		FuncGenerator( StructDecl *aggregateDecl, StructInstType *refType, unsigned int functionNesting, const std::list< TypeDecl* > & typeParams, OutputIterator out ) : aggregateDecl( aggregateDecl ), refType( refType ), functionNesting( functionNesting ), typeParams( typeParams ), out( out ) {}

		/// generates a function (?{}, ?=?, ^?{}) based on the data argument and members. If function is generated, inserts the type into the map.
		void gen( const FuncData & data, bool concurrent_type ) {
			if ( ! shouldGenerate( data.map, aggregateDecl ) ) return;
			FunctionType * ftype = data.genType( refType );

			if(concurrent_type && InitTweak::isDestructor( data.fname )) {
				ftype->get_parameters().front()->get_type()->set_mutex( true );
			}

			cloneAll( typeParams, ftype->get_forall() );
			*out++ = genFunc( data.fname, ftype, functionNesting );
			data.map.insert( Mangler::mangleType( refType ), true );
		}
	};

	template< typename OutputIterator >
	FuncGenerator<OutputIterator> makeFuncGenerator( StructDecl *aggregateDecl, StructInstType *refType, unsigned int functionNesting, const std::list< TypeDecl* > & typeParams, OutputIterator out ) {
		return FuncGenerator<OutputIterator>( aggregateDecl, refType, functionNesting, typeParams, out );
	}

	/// generates a single enumeration assignment expression
	ApplicationExpr * genEnumAssign( FunctionType * ftype, FunctionDecl * assignDecl ) {
		// 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
		// NOTE: ftype is not necessarily the functionType belonging to assignDecl - ftype is the
		// type of the function that this expression is being generated for (so that the correct
		// parameters) are using in the variable exprs
		assert( ftype->get_parameters().size() == 2 );
		ObjectDecl * dstParam = safe_dynamic_cast< ObjectDecl * >( ftype->get_parameters().front() );
		ObjectDecl * srcParam = safe_dynamic_cast< ObjectDecl * >( ftype->get_parameters().back() );

		VariableExpr * assignVarExpr = new VariableExpr( assignDecl );
		Type * assignVarExprType = assignVarExpr->get_result();
		assignVarExprType = new PointerType( Type::Qualifiers(), assignVarExprType );
		assignVarExpr->set_result( assignVarExprType );
		ApplicationExpr * assignExpr = new ApplicationExpr( assignVarExpr );
		assignExpr->get_args().push_back( new VariableExpr( dstParam ) );
		assignExpr->get_args().push_back( new VariableExpr( srcParam ) );
		return assignExpr;
	}

	// E ?=?(E volatile*, int),
	//   ?=?(E _Atomic volatile*, int);
	void makeEnumFunctions( EnumInstType *refType, unsigned int functionNesting, std::list< Declaration * > &declsToAdd ) {

		// T ?=?(E *, E);
		FunctionType *assignType = genAssignType( refType );

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

		// void ?{}(E *, E);
		FunctionType *copyCtorType = genCopyType( refType->clone() );

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

		// 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 = genFunc( "?=?", assignType, functionNesting, true );
		FunctionDecl *ctorDecl = genFunc( "?{}", ctorType, functionNesting, true );
		FunctionDecl *copyCtorDecl = genFunc( "?{}", copyCtorType, functionNesting, true );
		FunctionDecl *dtorDecl = genFunc( "^?{}", dtorType, functionNesting, true );

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

		declsToAdd.push_back( ctorDecl );
		declsToAdd.push_back( copyCtorDecl );
		declsToAdd.push_back( dtorDecl );
		declsToAdd.push_back( assignDecl ); // assignment should come last since it uses copy constructor in return
	}

	/// generates a single struct member operation (constructor call, destructor call, assignment call)
	void makeStructMemberOp( ObjectDecl * dstParam, Expression * src, DeclarationWithType * field, FunctionDecl * func, bool isDynamicLayout, bool forward = true ) {
		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 = UntypedExpr::createDeref( 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 ) {
			// xxx - there used to be a dereference on returnVal, but this seems to have been wrong?
			Expression *retselect = new MemberExpr( field, new VariableExpr( returnVal ) );
			genImplicitCall( srcParam, retselect, func->get_name(), back_inserter( func->get_statements()->get_kids() ), field, forward );
		} // if
	}

	/// generates the body of a struct function by iterating the struct members (via parameters) - generates default ctor, copy ctor, assignment, and dtor bodies, but NOT field ctor bodies
	template<typename Iterator>
	void makeStructFunctionBody( Iterator member, Iterator end, FunctionDecl * func, 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_const() && 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, 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, 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, isDynamicLayout );
					++parameter;
				} else {
					// no matching parameter, initialize field with default ctor
					makeStructMemberOp( dstParam, NULL, field, func, isDynamicLayout );
				}
			}
		}
	}

	/// generates struct constructors, destructor, and assignment functions
	void makeStructFunctions( StructDecl *aggregateDecl, StructInstType *refType, unsigned int functionNesting, std::list< Declaration * > & declsToAdd, const std::vector< FuncData > & data ) {
		// Builtins do not use autogeneration.
		if ( aggregateDecl->get_linkage() == LinkageSpec::Builtin ||
			 aggregateDecl->get_linkage() == LinkageSpec::BuiltinC ) {
			return;
		}

		// Make function polymorphic in same parameters as generic struct, if applicable
		const std::list< TypeDecl* > & typeParams = aggregateDecl->get_parameters(); // List of type variables to be placed on the generated functions
		bool isDynamicLayout = hasDynamicLayout( aggregateDecl );  // NOTE this flag is an incredibly ugly kludge; we should fix the assignment signature instead (ditto for union)

		// generate each of the functions based on the supplied FuncData objects
		std::list< FunctionDecl * > newFuncs;
		auto generator = makeFuncGenerator( aggregateDecl, refType, functionNesting, typeParams, back_inserter( newFuncs ) );
		for ( const FuncData & d : data ) {
			generator.gen( d, aggregateDecl->is_thread() || aggregateDecl->is_monitor() );
		}

		// field ctors are only generated if default constructor and copy constructor are both generated
		unsigned numCtors = std::count_if( newFuncs.begin(), newFuncs.end(), [](FunctionDecl * dcl) { return InitTweak::isConstructor( dcl->get_name() ); } );

		if ( functionNesting == 0 ) {
			// forward declare if top-level struct, so that
			// type is complete as soon as its body ends
			// Note: this is necessary if we want structs which contain
			// generic (otype) structs as members.
			for ( FunctionDecl * dcl : newFuncs ) {
				addForwardDecl( dcl, declsToAdd );
			}
		}

		for ( FunctionDecl * dcl : newFuncs ) {
			// generate appropriate calls to member ctor, assignment
			// destructor needs to do everything in reverse, so pass "forward" based on whether the function is a destructor
			if ( ! InitTweak::isDestructor( dcl->get_name() ) ) {
				makeStructFunctionBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), dcl, isDynamicLayout );
			} else {
				makeStructFunctionBody( aggregateDecl->get_members().rbegin(), aggregateDecl->get_members().rend(), dcl, isDynamicLayout, false );
			}
			if ( InitTweak::isAssignment( dcl->get_name() ) ) {
				// assignment needs to return a value
				FunctionType * assignType = dcl->get_functionType();
				assert( assignType->get_parameters().size() == 2 );
				ObjectDecl * srcParam = safe_dynamic_cast< ObjectDecl * >( assignType->get_parameters().back() );
				dcl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );
			}
			declsToAdd.push_back( dcl );
		}

		// 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)
		// Field constructors are only generated if default and copy constructor
		// are generated, since they need access to both
		if ( numCtors == 2 ) {
			FunctionType * memCtorType = genDefaultType( refType );
			cloneAll( typeParams, memCtorType->get_forall() );
			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(), Type::StorageClasses(), LinkageSpec::Cforall, 0, member->get_type()->clone(), 0 ) );
				FunctionDecl * ctor = genFunc( "?{}", memCtorType->clone(), functionNesting );
				makeStructFieldCtorBody( aggregateDecl->get_members().begin(), aggregateDecl->get_members().end(), ctor, isDynamicLayout );
				declsToAdd.push_back( ctor );
			}
			delete memCtorType;
		}
	}

	/// generate a single union assignment expression (using memcpy)
	template< typename OutputIterator >
	void makeUnionFieldsAssignment( ObjectDecl * srcParam, ObjectDecl * dstParam, 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 );
	}

	/// generates the body of a union assignment/copy constructor/field constructor
	void makeUnionAssignBody( FunctionDecl * funcDecl ) {
		FunctionType * ftype = funcDecl->get_functionType();
		assert( ftype->get_parameters().size() == 2 );
		ObjectDecl * dstParam = safe_dynamic_cast< ObjectDecl * >( ftype->get_parameters().front() );
		ObjectDecl * srcParam = safe_dynamic_cast< ObjectDecl * >( ftype->get_parameters().back() );
		ObjectDecl * returnVal = nullptr;
		if ( ! ftype->get_returnVals().empty() ) {
			returnVal = safe_dynamic_cast< ObjectDecl * >( ftype->get_returnVals().front() );
		}

		makeUnionFieldsAssignment( srcParam, dstParam, back_inserter( funcDecl->get_statements()->get_kids() ) );
		if ( returnVal ) {
			funcDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );
		}
	}

	/// generates union constructors, destructors, and assignment operator
	void makeUnionFunctions( UnionDecl *aggregateDecl, UnionInstType *refType, unsigned int functionNesting, std::list< Declaration * > & declsToAdd ) {
		// Make function polymorphic in same parameters as generic union, if applicable
		const std::list< TypeDecl* > & typeParams = aggregateDecl->get_parameters(); // List of type variables to be placed on the generated functions
		
		// default ctor/dtor need only first parameter
		// void ?{}(T *); void ^?{}(T *);
		FunctionType *ctorType = genDefaultType( refType );
		FunctionType *dtorType = genDefaultType( refType );

		// copy ctor needs both parameters
		// void ?{}(T *, T);
		FunctionType *copyCtorType = genCopyType( refType );

		// assignment needs both and return value
		// T ?=?(T *, T);
		FunctionType *assignType = genAssignType( refType );

		cloneAll( typeParams, ctorType->get_forall() );
		cloneAll( typeParams, dtorType->get_forall() );
		cloneAll( typeParams, copyCtorType->get_forall() );
		cloneAll( typeParams, assignType->get_forall() );

		// 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 = genFunc( "?=?", assignType, functionNesting );
		FunctionDecl *ctorDecl = genFunc( "?{}",  ctorType, functionNesting );
		FunctionDecl *copyCtorDecl = genFunc( "?{}", copyCtorType, functionNesting );
		FunctionDecl *dtorDecl = genFunc( "^?{}", dtorType, functionNesting );

		makeUnionAssignBody( assignDecl );

		// body of assignment and copy ctor is the same
		makeUnionAssignBody( copyCtorDecl );

		// 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", Type::StorageClasses(), LinkageSpec::Cforall, 0, field->get_type()->clone(), 0 );

				FunctionType * memCtorType = ctorType->clone();
				memCtorType->get_parameters().push_back( srcParam );
				FunctionDecl * ctor = genFunc( "?{}", memCtorType, functionNesting );

				makeUnionAssignBody( ctor );
				memCtors.push_back( ctor );
				// only generate a ctor for the first field
				break;
			}
		}

		declsToAdd.push_back( ctorDecl );
		declsToAdd.push_back( copyCtorDecl );
		declsToAdd.push_back( dtorDecl );
		declsToAdd.push_back( assignDecl ); // assignment should come last since it uses copy constructor in return
		declsToAdd.splice( declsToAdd.end(), memCtors );
	}

	AutogenerateRoutines::AutogenerateRoutines() {
		// the order here determines the order that these functions are generated.
		// assignment should come last since it uses copy constructor in return.
		data.push_back( FuncData( "?{}", genDefaultType, constructable ) );
		data.push_back( FuncData( "?{}", genCopyType, copyable ) );
		data.push_back( FuncData( "^?{}", genDefaultType, destructable ) );
		data.push_back( FuncData( "?=?", genAssignType, assignable ) );
	}

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

	void AutogenerateRoutines::visit( StructDecl *structDecl ) {
		if ( structDecl->has_body() && structsDone.find( structDecl->get_name() ) == structsDone.end() ) {
			StructInstType structInst( Type::Qualifiers(), structDecl->get_name() );
			for ( TypeDecl * typeDecl : structDecl->get_parameters() ) {
				// need to visit assertions so that they are added to the appropriate maps
				acceptAll( typeDecl->get_assertions(), *this );
				structInst.get_parameters().push_back( new TypeExpr( new TypeInstType( Type::Qualifiers(), typeDecl->get_name(), typeDecl ) ) );
			}
			structInst.set_baseStruct( structDecl );
			makeStructFunctions( structDecl, &structInst, functionNesting, declsToAddAfter, data );
			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 );
			for ( TypeDecl * typeDecl : unionDecl->get_parameters() ) {
				unionInst.get_parameters().push_back( new TypeExpr( new TypeInstType( Type::Qualifiers(), typeDecl->get_name(), typeDecl ) ) );
			}
			makeUnionFunctions( unionDecl, &unionInst, functionNesting, declsToAddAfter );
		} // if
	}

	void AutogenerateRoutines::visit( TypeDecl *typeDecl ) {
		TypeInstType *typeInst = new TypeInstType( Type::Qualifiers(), typeDecl->get_name(), false );
		typeInst->set_baseType( typeDecl );
		ObjectDecl *src = new ObjectDecl( "_src", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, typeInst->clone(), nullptr );
		ObjectDecl *dst = new ObjectDecl( "_dst", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, new PointerType( Type::Qualifiers(), typeInst->clone() ), nullptr );

		std::list< Statement * > stmts;
		if ( typeDecl->get_base() ) {
			// xxx - generate ctor/dtors for typedecls, e.g.
			// otype T = int *;
			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.push_back( new ReturnStmt( std::list< Label >(), assign ) );
		} // if
		FunctionType *type = new FunctionType( Type::Qualifiers(), false );
		type->get_returnVals().push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::Cforall, 0, typeInst, 0 ) );
		type->get_parameters().push_back( dst );
		type->get_parameters().push_back( src );
		FunctionDecl *func = genFunc( "?=?", type, functionNesting );
		func->get_statements()->get_kids() = stmts;
		declsToAddAfter.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 ) {
		// record the existence of this function as appropriate
		insert( functionDecl, constructable, InitTweak::isDefaultConstructor );
		insert( functionDecl, assignable, InitTweak::isAssignment );
		insert( functionDecl, copyable, InitTweak::isCopyConstructor );
		insert( functionDecl, destructable, InitTweak::isDestructor );

		maybeAccept( functionDecl->get_functionType(), *this );
		functionNesting += 1;
		maybeAccept( functionDecl->get_statements(), *this );
		functionNesting -= 1;
	}

	void AutogenerateRoutines::visit( CompoundStmt *compoundStmt ) {
		constructable.beginScope();
		assignable.beginScope();
		copyable.beginScope();
		destructable.beginScope();
		visitStatement( compoundStmt );
		constructable.endScope();
		assignable.endScope();
		copyable.endScope();
		destructable.endScope();
	}

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

	void makeTupleFunctionBody( FunctionDecl * function ) {
		FunctionType * ftype = function->get_functionType();
		assertf( ftype->get_parameters().size() == 1 || ftype->get_parameters().size() == 2, "too many parameters in generated tuple function" );

		UntypedExpr * untyped = new UntypedExpr( new NameExpr( function->get_name() ) );

		/// xxx - &* is used to make this easier for later passes to handle
		untyped->get_args().push_back( new AddressExpr( UntypedExpr::createDeref( new VariableExpr( ftype->get_parameters().front() ) ) ) );
		if ( ftype->get_parameters().size() == 2 ) {
			untyped->get_args().push_back( new VariableExpr( ftype->get_parameters().back() ) );
		}
		function->get_statements()->get_kids().push_back( new ExprStmt( noLabels, untyped ) );
		function->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, UntypedExpr::createDeref( new VariableExpr( ftype->get_parameters().front() ) ) ) );
	}

	Type * AutogenTupleRoutines::mutate( TupleType * tupleType ) {
		tupleType = safe_dynamic_cast< TupleType * >( Parent::mutate( tupleType ) );
		std::string mangleName = SymTab::Mangler::mangleType( tupleType );
		if ( seenTuples.find( mangleName ) != seenTuples.end() ) return tupleType;
		seenTuples.insert( mangleName );

		// T ?=?(T *, T);
		FunctionType *assignType = genAssignType( tupleType );

		// void ?{}(T *); void ^?{}(T *);
		FunctionType *ctorType = genDefaultType( tupleType );
		FunctionType *dtorType = genDefaultType( tupleType );

		// void ?{}(T *, T);
		FunctionType *copyCtorType = genCopyType( tupleType );

		std::set< TypeDecl* > done;
		std::list< TypeDecl * > typeParams;
		for ( Type * t : *tupleType ) {
			if ( TypeInstType * ty = dynamic_cast< TypeInstType * >( t ) ) {
				if ( ! done.count( ty->get_baseType() ) ) {
					TypeDecl * newDecl = new TypeDecl( ty->get_baseType()->get_name(), Type::StorageClasses(), nullptr, TypeDecl::Any );
					TypeInstType * inst = new TypeInstType( Type::Qualifiers(), newDecl->get_name(), newDecl );
					newDecl->get_assertions().push_back( new FunctionDecl( "?=?", Type::StorageClasses(), LinkageSpec::Cforall, genAssignType( inst ), nullptr,
																		   std::list< Attribute * >(), Type::FuncSpecifiers( Type::Inline ) ) );
					newDecl->get_assertions().push_back( new FunctionDecl( "?{}", Type::StorageClasses(), LinkageSpec::Cforall, genDefaultType( inst ), nullptr,
																		   std::list< Attribute * >(), Type::FuncSpecifiers( Type::Inline ) ) );
					newDecl->get_assertions().push_back( new FunctionDecl( "?{}", Type::StorageClasses(), LinkageSpec::Cforall, genCopyType( inst ), nullptr,
																		   std::list< Attribute * >(), Type::FuncSpecifiers( Type::Inline ) ) );
					newDecl->get_assertions().push_back( new FunctionDecl( "^?{}", Type::StorageClasses(), LinkageSpec::Cforall, genDefaultType( inst ), nullptr,
																		   std::list< Attribute * >(), Type::FuncSpecifiers( Type::Inline ) ) );
					typeParams.push_back( newDecl );
					done.insert( ty->get_baseType() );
				}
			}
		}
		cloneAll( typeParams, ctorType->get_forall() );
		cloneAll( typeParams, dtorType->get_forall() );
		cloneAll( typeParams, copyCtorType->get_forall() );
		cloneAll( typeParams, assignType->get_forall() );

		FunctionDecl *assignDecl = genFunc( "?=?", assignType, functionNesting );
		FunctionDecl *ctorDecl = genFunc( "?{}", ctorType, functionNesting );
		FunctionDecl *copyCtorDecl = genFunc( "?{}", copyCtorType, functionNesting );
		FunctionDecl *dtorDecl = genFunc( "^?{}", dtorType, functionNesting );

		makeTupleFunctionBody( assignDecl );
		makeTupleFunctionBody( ctorDecl );
		makeTupleFunctionBody( copyCtorDecl );
		makeTupleFunctionBody( dtorDecl );

		addDeclaration( ctorDecl );
		addDeclaration( copyCtorDecl );
		addDeclaration( dtorDecl );
		addDeclaration( assignDecl ); // assignment should come last since it uses copy constructor in return

		return tupleType;
	}

	DeclarationWithType * AutogenTupleRoutines::mutate( FunctionDecl *functionDecl ) {
		functionDecl->set_functionType( maybeMutate( functionDecl->get_functionType(), *this ) );
		functionNesting += 1;
		functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
		functionNesting -= 1;
		return functionDecl;
	}

	CompoundStmt * AutogenTupleRoutines::mutate( CompoundStmt *compoundStmt ) {
		seenTuples.beginScope();
		compoundStmt = safe_dynamic_cast< CompoundStmt * >( Parent::mutate( compoundStmt ) );
		seenTuples.endScope();
		return compoundStmt;
	}
} // SymTab

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