//
// 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.
//
// FixInit.h --
//
// Author           : Rob Schluntz
// Created On       : Wed Jan 13 16:29:30 2016
// Last Modified By : Peter A. Buhr
// Last Modified On : Wed Jul  6 17:34:46 2016
// Update Count     : 33
//

#include <stack>
#include <list>
#include <iterator>
#include <algorithm>
#include "FixInit.h"
#include "InitTweak.h"
#include "ResolvExpr/Resolver.h"
#include "ResolvExpr/typeops.h"
#include "SynTree/Declaration.h"
#include "SynTree/Type.h"
#include "SynTree/Expression.h"
#include "SynTree/Statement.h"
#include "SynTree/Initializer.h"
#include "SynTree/Mutator.h"
#include "SymTab/Indexer.h"
#include "GenPoly/PolyMutator.h"
#include "SynTree/AddStmtVisitor.h"

bool ctordtorp = false;
bool ctorp = false;
bool cpctorp = false;
bool dtorp = false;
#define PRINT( text ) if ( ctordtorp ) { text }
#define CP_CTOR_PRINT( text ) if ( ctordtorp || cpctorp ) { text }
#define DTOR_PRINT( text ) if ( ctordtorp || dtorp ) { text }

namespace InitTweak {
	namespace {
		const std::list<Label> noLabels;
		const std::list<Expression*> noDesignators;

		class InsertImplicitCalls : public GenPoly::PolyMutator {
		public:
			/// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
			/// function calls need their parameters to be copy constructed
			static void insert( std::list< Declaration * > & translationUnit );

			virtual Expression * mutate( ApplicationExpr * appExpr );
		};

		class ResolveCopyCtors : public SymTab::Indexer {
		public:
			/// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr,
			/// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
			/// arguments and return value temporaries
			static void resolveImplicitCalls( std::list< Declaration * > & translationUnit );

			virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr );

			/// create and resolve ctor/dtor expression: fname(var, [cpArg])
			ApplicationExpr * makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg = NULL );
			/// true if type does not need to be copy constructed to ensure correctness
			bool skipCopyConstruct( Type * );
		private:
			TypeSubstitution * env;
		};

		/// collects constructed object decls - used as a base class
		class ObjDeclCollector : public AddStmtVisitor {
		  public:
			typedef AddStmtVisitor Parent;
			using Parent::visit;
			typedef std::set< ObjectDecl * > ObjectSet;
			virtual void visit( CompoundStmt *compoundStmt );
			virtual void visit( DeclStmt *stmt );
		  protected:
			ObjectSet curVars;
		};

		struct printSet {
			typedef ObjDeclCollector::ObjectSet ObjectSet;
			printSet( const ObjectSet & objs ) : objs( objs ) {}
			const ObjectSet & objs;
		};
		std::ostream & operator<<( std::ostream & out, const printSet & set) {
			out << "{ ";
			for ( ObjectDecl * obj : set.objs ) {
				out << obj->get_name() << ", " ;
			} // for
			out << " }";
			return out;
		}

		class LabelFinder : public ObjDeclCollector {
		  public:
			typedef ObjDeclCollector Parent;
			typedef std::map< Label, ObjectSet > LabelMap;
			// map of Label -> live variables at that label
			LabelMap vars;

			void handleStmt( Statement * stmt );

			// xxx - This needs to be done better.
			// allow some generalization among different kinds of nodes with with similar parentage (e.g. all
			// expressions, all statements, etc.)  important to have this to provide a single entry point so that as new
			// subclasses are added, there is only one place that the code has to be updated, rather than ensure that
			// every specialized class knows about every new kind of statement that might be added.
			virtual void visit( CompoundStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( ExprStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( AsmStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( IfStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( WhileStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( ForStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( SwitchStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( ChooseStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( FallthruStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( CaseStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( BranchStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( ReturnStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( TryStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( CatchStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( FinallyStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( NullStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( DeclStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
			virtual void visit( ImplicitCtorDtorStmt *stmt ) { handleStmt( stmt ); return Parent::visit( stmt ); }
		};

		class InsertDtors : public ObjDeclCollector {
		public:
			/// insert destructor calls at the appropriate places.  must happen before CtorInit nodes are removed
			/// (currently by FixInit)
			static void insert( std::list< Declaration * > & translationUnit );

			typedef ObjDeclCollector Parent;
			typedef std::list< ObjectDecl * > OrderedDecls;
			typedef std::list< OrderedDecls > OrderedDeclsStack;

			InsertDtors( LabelFinder & finder ) : labelVars( finder.vars ) {}

			virtual void visit( ObjectDecl * objDecl );

			virtual void visit( CompoundStmt * compoundStmt );
			virtual void visit( ReturnStmt * returnStmt );
			virtual void visit( BranchStmt * stmt );
		private:
			void handleGoto( BranchStmt * stmt );

			LabelFinder::LabelMap & labelVars;
			OrderedDeclsStack reverseDeclOrder;
		};

		class FixInit : public GenPoly::PolyMutator {
		  public:
			/// expand each object declaration to use its constructor after it is declared.
			static void fixInitializers( std::list< Declaration * > &translationUnit );

			virtual DeclarationWithType * mutate( ObjectDecl *objDecl );
		};

		class FixCopyCtors : public GenPoly::PolyMutator {
		  public:
			/// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
			/// and destructors
			static void fixCopyCtors( std::list< Declaration * > &translationUnit );

			virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr );
		};
	} // namespace

	void fix( std::list< Declaration * > & translationUnit ) {
		InsertImplicitCalls::insert( translationUnit );
		ResolveCopyCtors::resolveImplicitCalls( translationUnit );
		InsertDtors::insert( translationUnit );
		FixInit::fixInitializers( translationUnit );

		// FixCopyCtors must happen after FixInit, so that destructors are placed correctly
		FixCopyCtors::fixCopyCtors( translationUnit );
	}

	namespace {
		void InsertImplicitCalls::insert( std::list< Declaration * > & translationUnit ) {
			InsertImplicitCalls inserter;
			mutateAll( translationUnit, inserter );
		}

		void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit ) {
			ResolveCopyCtors resolver;
			acceptAll( translationUnit, resolver );
		}

		void FixInit::fixInitializers( std::list< Declaration * > & translationUnit ) {
			FixInit fixer;
			mutateAll( translationUnit, fixer );
		}

		void InsertDtors::insert( std::list< Declaration * > & translationUnit ) {
			LabelFinder finder;
			InsertDtors inserter( finder );
			acceptAll( translationUnit, finder );
			acceptAll( translationUnit, inserter );
		}

		void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit ) {
			FixCopyCtors fixer;
			mutateAll( translationUnit, fixer );
		}

		Expression * InsertImplicitCalls::mutate( ApplicationExpr * appExpr ) {
			appExpr = dynamic_cast< ApplicationExpr * >( Mutator::mutate( appExpr ) );
			assert( appExpr );

			if ( VariableExpr * function = dynamic_cast< VariableExpr * > ( appExpr->get_function() ) ) {
				if ( function->get_var()->get_linkage() == LinkageSpec::Intrinsic ) {
					// optimization: don't need to copy construct in order to call intrinsic functions
					return appExpr;
				} else if ( DeclarationWithType * funcDecl = dynamic_cast< DeclarationWithType * > ( function->get_var() ) ) {
					FunctionType * ftype = dynamic_cast< FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
					assert( ftype );
					if ( (funcDecl->get_name() == "?{}" || funcDecl->get_name() == "?=?") && ftype->get_parameters().size() == 2 ) {
						Type * t1 = ftype->get_parameters().front()->get_type();
						Type * t2 = ftype->get_parameters().back()->get_type();
						PointerType * ptrType = dynamic_cast< PointerType * > ( t1 );
						assert( ptrType );

						if ( ResolvExpr::typesCompatible( ptrType->get_base(), t2, SymTab::Indexer() ) ) {
							// optimization: don't need to copy construct in order to call a copy constructor or
							// assignment operator
							return appExpr;
						} // if
					} else if ( funcDecl->get_name() == "^?{}" ) {
						// correctness: never copy construct arguments to a destructor
						return appExpr;
					} // if
				} // if
			} // if
			CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; )

			// wrap each function call so that it is easy to identify nodes that have to be copy constructed
			ImplicitCopyCtorExpr * expr = new ImplicitCopyCtorExpr( appExpr );
			// save the type substitution onto the new node so that it is easy to find.
			// Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion.
			// The substitution is needed to obtain the type of temporary variables so that copy constructor
			// calls can be resolved. Normally this is what PolyMutator is for, but the pass that resolves
			// copy constructor calls must be an Indexer. We could alternatively make a PolyIndexer which
			// saves the environment, or compute the types of temporaries here, but it's much simpler to
			// save the environment here, and more cohesive to compute temporary variables and resolve copy
			// constructor calls together.
			assert( env );
			expr->set_env( env );
			return expr;
		}

		bool ResolveCopyCtors::skipCopyConstruct( Type * type ) {
			return dynamic_cast< VarArgsType * >( type ) || GenPoly::getFunctionType( type );
		}

		ApplicationExpr * ResolveCopyCtors::makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg ) {
			assert( var );
			UntypedExpr * untyped = new UntypedExpr( new NameExpr( fname ) );
			untyped->get_args().push_back( new AddressExpr( new VariableExpr( var ) ) );
			if (cpArg) untyped->get_args().push_back( cpArg );

			// resolve copy constructor
			// should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed
			// (VariableExpr and already resolved expression)
			CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; )
			ApplicationExpr * resolved = dynamic_cast< ApplicationExpr * >( ResolvExpr::findVoidExpression( untyped, *this ) );
			if ( resolved->get_env() ) {
				env->add( *resolved->get_env() );
			} // if

			assert( resolved );
			delete untyped;
			return resolved;
		}

		void ResolveCopyCtors::visit( ImplicitCopyCtorExpr *impCpCtorExpr ) {
			static UniqueName tempNamer("_tmp_cp");
			static UniqueName retNamer("_tmp_cp_ret");

			CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
			Visitor::visit( impCpCtorExpr );
			env = impCpCtorExpr->get_env(); // xxx - maybe we really should just have a PolyIndexer...

			ApplicationExpr * appExpr = impCpCtorExpr->get_callExpr();

			// take each argument and attempt to copy construct it.
			for ( Expression * & arg : appExpr->get_args() ) {
				CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *impCpCtorExpr->get_env() << std::endl; )
				// xxx - need to handle tuple arguments
				assert( ! arg->get_results().empty() );
				Type * result = arg->get_results().front();
				if ( skipCopyConstruct( result ) ) continue; // skip certain non-copyable types
				// type may involve type variables, so apply type substitution to get temporary variable's actual type
				result = result->clone();
				impCpCtorExpr->get_env()->apply( result );
				ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
				tmp->get_type()->set_isConst( false );

				// create and resolve copy constructor
				CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
				ApplicationExpr * cpCtor = makeCtorDtor( "?{}", tmp, arg );

				// if the chosen constructor is intrinsic, the copy is unnecessary, so
				// don't create the temporary and don't call the copy constructor
				VariableExpr * function = dynamic_cast< VariableExpr * >( cpCtor->get_function() );
				assert( function );
				if ( function->get_var()->get_linkage() != LinkageSpec::Intrinsic ) {
					// replace argument to function call with temporary
					arg = new CommaExpr( cpCtor, new VariableExpr( tmp ) );
					impCpCtorExpr->get_tempDecls().push_back( tmp );
					impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", tmp ) );
				} // if
			} // for

			// each return value from the call needs to be connected with an ObjectDecl at the call site, which is
			// initialized with the return value and is destructed later
			// xxx - handle multiple return values
			ApplicationExpr * callExpr = impCpCtorExpr->get_callExpr();
			// xxx - is this right? callExpr may not have the right environment, because it was attached at a higher
			// level. Trying to pass that environment along.
			callExpr->set_env( impCpCtorExpr->get_env()->clone() );
			for ( Type * result : appExpr->get_results() ) {
				result = result->clone();
				impCpCtorExpr->get_env()->apply( result );
				ObjectDecl * ret = new ObjectDecl( retNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
				ret->get_type()->set_isConst( false );
				impCpCtorExpr->get_returnDecls().push_back( ret );
				CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
				impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
			} // for
			CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
		}


		Expression * FixCopyCtors::mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) {
			CP_CTOR_PRINT( std::cerr << "FixCopyCtors: " << impCpCtorExpr << std::endl; )

			impCpCtorExpr = dynamic_cast< ImplicitCopyCtorExpr * >( Mutator::mutate( impCpCtorExpr ) );
			assert( impCpCtorExpr );

			std::list< ObjectDecl * > & tempDecls = impCpCtorExpr->get_tempDecls();
			std::list< ObjectDecl * > & returnDecls = impCpCtorExpr->get_returnDecls();
			std::list< Expression * > & dtors = impCpCtorExpr->get_dtors();

			// add all temporary declarations and their constructors
			for ( ObjectDecl * obj : tempDecls ) {
				stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
			} // for
			for ( ObjectDecl * obj : returnDecls ) {
				stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
			} // for

			// add destructors after current statement
			for ( Expression * dtor : dtors ) {
				stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
			} // for

			// xxx - update to work with multiple return values
			ObjectDecl * returnDecl = returnDecls.empty() ? NULL : returnDecls.front();
			Expression * callExpr = impCpCtorExpr->get_callExpr();

			CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; )

			// detach fields from wrapper node so that it can be deleted without deleting too much
			dtors.clear();
			tempDecls.clear();
			returnDecls.clear();
			impCpCtorExpr->set_callExpr( NULL );
			impCpCtorExpr->set_env( NULL );
			delete impCpCtorExpr;

			if ( returnDecl ) {
				UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
				assign->get_args().push_back( new VariableExpr( returnDecl ) );
				assign->get_args().push_back( callExpr );
				// know the result type of the assignment is the type of the LHS (minus the pointer), so
				// add that onto the assignment expression so that later steps have the necessary information
				assign->add_result( returnDecl->get_type()->clone() );

				Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
				if ( callExpr->get_results().front()->get_isLvalue() ) {
					// lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
					// non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
					// type of the return temporary from T to T* to properly capture the return value. Then dereference
					// the result of the comma expression, since the lvalue returning call was originally wrapped with
					// an AddressExpr.  Effectively, this turns
					//   lvalue T f();
					//   &*f()
					// into
					//   T * tmp_cp_retN;
					//   tmp_cp_ret_N = &*(tmp_cp_ret_N = &*f(), tmp_cp_ret);
					// which work out in terms of types, but is pretty messy. It would be nice to find a better way.
					assign->get_args().back() = new AddressExpr( assign->get_args().back() );

					Type * resultType = returnDecl->get_type()->clone();
					returnDecl->set_type( new PointerType( Type::Qualifiers(), returnDecl->get_type() ) );
					UntypedExpr * deref = new UntypedExpr( new NameExpr( "*?" ) );
					deref->get_args().push_back( retExpr );
					deref->add_result( resultType );
					retExpr = deref;
				} // if
				// xxx - might need to set env on retExpr...
				// retExpr->set_env( env->clone() );
				return retExpr;
			} else {
				return callExpr;
			} // if
		}

		DeclarationWithType *FixInit::mutate( ObjectDecl *objDecl ) {
			// first recursively handle pieces of ObjectDecl so that they aren't missed by other visitors when the init
			// is removed from the ObjectDecl
			objDecl = dynamic_cast< ObjectDecl * >( Mutator::mutate( objDecl ) );

			if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
				// a decision should have been made by the resolver, so ctor and init are not both non-NULL
				assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
				if ( Statement * ctor = ctorInit->get_ctor() ) {
					if ( objDecl->get_storageClass() == DeclarationNode::Static ) {
						// generate:
						// static bool __objName_uninitialized = true;
						// if (__objName_uninitialized) {
						//   __ctor(__objName);
						//   void dtor_atexit() {
						//     __dtor(__objName);
						//   }
						//   on_exit(dtorOnExit, &__objName);
						//   __objName_uninitialized = false;
						// }

						// generate first line
						BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
						SingleInit * boolInitExpr = new SingleInit( new ConstantExpr( Constant( boolType->clone(), "1" ) ), noDesignators );
						ObjectDecl * isUninitializedVar = new ObjectDecl( objDecl->get_mangleName() + "_uninitialized", DeclarationNode::Static, LinkageSpec::Cforall, 0, boolType, boolInitExpr );
						isUninitializedVar->fixUniqueId();

						// void dtor_atexit(...) {...}
						FunctionDecl * dtorCaller = new FunctionDecl( objDecl->get_mangleName() + "_dtor_atexit", DeclarationNode::NoStorageClass, LinkageSpec::C, new FunctionType( Type::Qualifiers(), false ), new CompoundStmt( noLabels ), false, false );
						dtorCaller->fixUniqueId();
						dtorCaller->get_statements()->get_kids().push_back( ctorInit->get_dtor()->clone() );

						// on_exit(dtor_atexit);
						UntypedExpr * callAtexit = new UntypedExpr( new NameExpr( "atexit" ) );
						callAtexit->get_args().push_back( new VariableExpr( dtorCaller ) );

						// __objName_uninitialized = false;
						UntypedExpr * setTrue = new UntypedExpr( new NameExpr( "?=?" ) );
						setTrue->get_args().push_back( new VariableExpr( isUninitializedVar ) );
						setTrue->get_args().push_back( new ConstantExpr( Constant( boolType->clone(), "0" ) ) );

						// generate body of if
						CompoundStmt * initStmts = new CompoundStmt( noLabels );
						std::list< Statement * > & body = initStmts->get_kids();
						body.push_back( ctor );
						body.push_back( new DeclStmt( noLabels, dtorCaller ) );
						body.push_back( new ExprStmt( noLabels, callAtexit ) );
						body.push_back( new ExprStmt( noLabels, setTrue ) );

						// put it all together
						IfStmt * ifStmt = new IfStmt( noLabels, new VariableExpr( isUninitializedVar ), initStmts, 0 );
						stmtsToAddAfter.push_back( new DeclStmt( noLabels, isUninitializedVar ) );
						stmtsToAddAfter.push_back( ifStmt );
					} else {
						stmtsToAddAfter.push_back( ctor );
					} // if
					objDecl->set_init( NULL );
					ctorInit->set_ctor( NULL );
				} else if ( Initializer * init = ctorInit->get_init() ) {
					objDecl->set_init( init );
					ctorInit->set_init( NULL );
				} else {
					// no constructor and no initializer, which is okay
					objDecl->set_init( NULL );
				} // if
				delete ctorInit;
			} // if
			return objDecl;
		}

		void ObjDeclCollector::visit( CompoundStmt *compoundStmt ) {
			std::set< ObjectDecl * > prevVars = curVars;
			Parent::visit( compoundStmt );
			curVars = prevVars;
		}

		void ObjDeclCollector::visit( DeclStmt *stmt ) {
			// keep track of all variables currently in scope
			if ( ObjectDecl * objDecl = dynamic_cast< ObjectDecl * > ( stmt->get_decl() ) ) {
				curVars.insert( objDecl );
			} // if
			Parent::visit( stmt );
		}

		void LabelFinder::handleStmt( Statement * stmt ) {
			// for each label, remember the variables in scope at that label.
			for ( Label l : stmt->get_labels() ) {
				vars[l] = curVars;
			} // for
		}

		template<typename Iterator, typename OutputIterator>
		void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
			for ( Iterator it = begin ; it != end ; ++it ) {
				// extract destructor statement from the object decl and insert it into the output. Note that this is
				// only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
				// calls an intrinsic dtor then the call must (and will) still be generated since the argument may
				// contain side effects.
				ObjectDecl * objDecl = *it;
				ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
				assert( ctorInit && ctorInit->get_dtor() );
				*out++ = ctorInit->get_dtor()->clone();
			} // for
		}

		void InsertDtors::visit( ObjectDecl * objDecl ) {
			// remember non-static destructed objects so that their destructors can be inserted later
			if ( objDecl->get_storageClass() != DeclarationNode::Static ) {
				if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
					// a decision should have been made by the resolver, so ctor and init are not both non-NULL
					assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
					Statement * dtor = ctorInit->get_dtor();
					if ( dtor && ! isInstrinsicSingleArgCallStmt( dtor ) ) {
						// don't need to call intrinsic dtor, because it does nothing, but
						// non-intrinsic dtors must be called
						reverseDeclOrder.front().push_front( objDecl );
					} // if
				} // if
			} // if
			Parent::visit( objDecl );
		}

		void InsertDtors::visit( CompoundStmt * compoundStmt ) {
			// visit statements - this will also populate reverseDeclOrder list.  don't want to dump all destructors
			// when block is left, just the destructors associated with variables defined in this block, so push a new
			// list to the top of the stack so that we can differentiate scopes
			reverseDeclOrder.push_front( OrderedDecls() );
			Parent::visit( compoundStmt );

			// add destructors for the current scope that we're exiting
			std::list< Statement * > & statements = compoundStmt->get_kids();
			insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
			reverseDeclOrder.pop_front();
		}

		void InsertDtors::visit( ReturnStmt * returnStmt ) {
			// return exits all scopes, so dump destructors for all scopes
			for ( OrderedDecls & od : reverseDeclOrder ) {
				insertDtors( od.begin(), od.end(), back_inserter( stmtsToAdd ) );
			} // for
		}

		// Handle break/continue/goto in the same manner as C++.  Basic idea: any objects that are in scope at the
		// BranchStmt but not at the labelled (target) statement must be destructed.  If there are any objects in scope
		// at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user
		// of the error.  See C++ Reference 6.6 Jump Statements for details.
		void InsertDtors::handleGoto( BranchStmt * stmt ) {
			assert( stmt->get_target() != "" && "BranchStmt missing a label" );
			// S_L = lvars = set of objects in scope at label definition
			// S_G = curVars = set of objects in scope at goto statement
			ObjectSet & lvars = labelVars[ stmt->get_target() ];

			DTOR_PRINT(
				std::cerr << "at goto label: " << stmt->get_target().get_name() << std::endl;
				std::cerr << "S_G = " << printSet( curVars ) << std::endl;
				std::cerr << "S_L = " << printSet( lvars ) << std::endl;
			)

			ObjectSet diff;
			// S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty
			std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) );
			DTOR_PRINT(
				std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl;
			)
			if ( ! diff.empty() ) {
				throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
			} // if
			// S_G-S_L results in set of objects that must be destructed
			diff.clear();
			std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
			DTOR_PRINT(
				std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
			)
			if ( ! diff.empty() ) {
				// go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
				OrderedDecls ordered;
				for ( OrderedDecls & rdo : reverseDeclOrder ) {
					// add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
					copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return diff.count( objDecl ); } );
				} // for
				insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAdd ) );
			} // if
		}

		void InsertDtors::visit( BranchStmt * stmt ) {
			switch( stmt->get_type() ) {
			  case BranchStmt::Continue:
			  case BranchStmt::Break:
				// could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
				// always be empty), but it serves as a small sanity check.
			  case BranchStmt::Goto:
				handleGoto( stmt );
				break;
			  default:
				assert( false );
			} // switch
		}
	} // namespace
} // namespace InitTweak

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