Index: libcfa/src/concurrency/clib/cfathread.cfa
===================================================================
--- libcfa/src/concurrency/clib/cfathread.cfa	(revision 51e7583fdb45808075dc046654f4243e2cb2e109)
+++ libcfa/src/concurrency/clib/cfathread.cfa	(revision f7136f783580d39320d5c60029508f18953c397a)
@@ -59,5 +59,5 @@
 	void cfathread_setproccnt( int ncnt ) {
 		assert( ncnt >= 1 );
-		adelete(proc_cnt, procs);
+		adelete( procs );
 
 		proc_cnt = ncnt - 1;
Index: libcfa/src/stdlib.cfa
===================================================================
--- libcfa/src/stdlib.cfa	(revision 51e7583fdb45808075dc046654f4243e2cb2e109)
+++ libcfa/src/stdlib.cfa	(revision f7136f783580d39320d5c60029508f18953c397a)
@@ -58,6 +58,7 @@
 
 forall( dtype T | sized(T) | { void ^?{}( T & ); } )
-void adelete( size_t dim, T arr[] ) {
+void adelete( T arr[] ) {
 	if ( arr ) {										// ignore null
+		size_t dim = malloc_size( arr ) / sizeof( T );
 		for ( int i = dim - 1; i >= 0; i -= 1 ) {		// reverse allocation order, must be unsigned
 			^(arr[i]){};								// run destructor
@@ -68,6 +69,7 @@
 
 forall( dtype T | sized(T) | { void ^?{}( T & ); }, ttype Params | { void adelete( Params ); } )
-void adelete( size_t dim, T arr[], Params rest ) {
+void adelete( T arr[], Params rest ) {
 	if ( arr ) {										// ignore null
+		size_t dim = malloc_size( arr ) / sizeof( T );
 		for ( int i = dim - 1; i >= 0; i -= 1 ) {		// reverse allocation order, must be unsigned
 			^(arr[i]){};								// run destructor
Index: libcfa/src/stdlib.hfa
===================================================================
--- libcfa/src/stdlib.hfa	(revision 51e7583fdb45808075dc046654f4243e2cb2e109)
+++ libcfa/src/stdlib.hfa	(revision f7136f783580d39320d5c60029508f18953c397a)
@@ -263,6 +263,6 @@
 // Cforall allocation/deallocation and constructor/destructor, array types
 forall( dtype T | sized(T), ttype Params | { void ?{}( T &, Params ); } ) T * anew( size_t dim, Params p );
-forall( dtype T | sized(T) | { void ^?{}( T & ); } ) void adelete( size_t dim, T arr[] );
-forall( dtype T | sized(T) | { void ^?{}( T & ); }, ttype Params | { void adelete( Params ); } ) void adelete( size_t dim, T arr[], Params rest );
+forall( dtype T | sized(T) | { void ^?{}( T & ); } ) void adelete( T arr[] );
+forall( dtype T | sized(T) | { void ^?{}( T & ); }, ttype Params | { void adelete( Params ); } ) void adelete( T arr[], Params rest );
 
 //---------------------------------------
Index: src/InitTweak/FixInitNew.cpp
===================================================================
--- src/InitTweak/FixInitNew.cpp	(revision 51e7583fdb45808075dc046654f4243e2cb2e109)
+++ src/InitTweak/FixInitNew.cpp	(revision f7136f783580d39320d5c60029508f18953c397a)
@@ -61,1374 +61,1319 @@
 
 namespace InitTweak {
-	namespace {
-		struct SelfAssignChecker {
-			void previsit( const ast::ApplicationExpr * appExpr );
-		};
-
-		struct StmtExprResult {
-			static void link( std::list<ast::ptr<ast::Decl> > & translationUnit );
-
-			const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr );
-		};
-
-		struct InsertImplicitCalls : public ast::WithConstTypeSubstitution, public ast::WithShortCircuiting {
-			/// 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<ast::ptr<ast::Decl> > & translationUnit );
-
-			const ast::Expr * postvisit( const ast::ApplicationExpr * appExpr );
-
-			// only handles each UniqueExpr once
-			// if order of visit does not change, this should be safe
-			void previsit (const ast::UniqueExpr *);
-
-			std::unordered_set<decltype(ast::UniqueExpr::id)> visitedIds;
-		};
-
-		struct ResolveCopyCtors final : public ast::WithGuards, public ast::WithStmtsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting, public ast::WithVisitorRef<ResolveCopyCtors> {
-			/// 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<ast::ptr<ast::Decl> > & translationUnit );
-
-			const ast::Expr * postvisit( const ast::ImplicitCopyCtorExpr * impCpCtorExpr );
-			const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr );
-			const ast::UniqueExpr * previsit( const ast::UniqueExpr * unqExpr );
-
-			/// handles distant mutations of environment manually. 
-			/// WithConstTypeSubstitution cannot remember where the environment is from
-
-			/// MUST be called at start of overload previsit
-			void previsit( const ast::Expr * expr);
-			/// MUST be called at return of overload postvisit
-			const ast::Expr * postvisit(const ast::Expr * expr);
-
-			/// create and resolve ctor/dtor expression: fname(var, [cpArg])
-			const ast::Expr * makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg = nullptr );
-			/// true if type does not need to be copy constructed to ensure correctness
-			bool skipCopyConstruct( const ast::Type * type );
-			ast::ptr< ast::Expr > copyConstructArg( const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal );
-			ast::Expr * destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg );
-		private:
-			/// hack to implement WithTypeSubstitution while conforming to mutation safety.
-			ast::TypeSubstitution * env;
-			bool                    envModified;
-		};
-
-		/// collects constructed object decls - used as a base class
-		struct ObjDeclCollector : public ast::WithGuards, public ast::WithShortCircuiting {
-			// use ordered data structure to maintain ordering for set_difference and for consistent error messages
-			typedef std::list< const ast::ObjectDecl * > ObjectSet;
-			void previsit( const ast::CompoundStmt *compoundStmt );
-			void previsit( const ast::DeclStmt *stmt );
-
-			// don't go into other functions
-			void previsit( const ast::FunctionDecl * ) { visit_children = false; }
-
-		  protected:
-			ObjectSet curVars;
-		};
-
-		// debug
-		template<typename ObjectSet>
-		struct PrintSet {
-			PrintSet( const ObjectSet & objs ) : objs( objs ) {}
-			const ObjectSet & objs;
-		};
-		template<typename ObjectSet>
-		PrintSet<ObjectSet> printSet( const ObjectSet & objs ) { return PrintSet<ObjectSet>( objs ); }
-		template<typename ObjectSet>
-		std::ostream & operator<<( std::ostream & out, const PrintSet<ObjectSet> & set) {
-			out << "{ ";
-			for ( auto & obj : set.objs ) {
-				out << obj->name << ", " ;
-			} // for
-			out << " }";
-			return out;
-		}
-
-		struct LabelFinder final : public ObjDeclCollector {
-			typedef std::map< std::string, ObjectSet > LabelMap;
-			// map of Label -> live variables at that label
-			LabelMap vars;
-
-			typedef ObjDeclCollector Parent;
-			using Parent::previsit;
-			void previsit( const ast::Stmt * stmt );
-
-			void previsit( const ast::CompoundStmt *compoundStmt );
-			void previsit( const ast::DeclStmt *stmt );
-		};
-
-		struct InsertDtors final : public ObjDeclCollector, public ast::WithStmtsToAdd<> {
-			/// insert destructor calls at the appropriate places.  must happen before CtorInit nodes are removed
-			/// (currently by FixInit)
-			static void insert( std::list< ast::ptr<ast::Decl> > & translationUnit );
-
-			typedef std::list< ObjectDecl * > OrderedDecls;
-			typedef std::list< OrderedDecls > OrderedDeclsStack;
-
-			InsertDtors( ast::Pass<LabelFinder> & finder ) : finder( finder ), labelVars( finder.core.vars ) {}
-
-			typedef ObjDeclCollector Parent;
-			using Parent::previsit;
-
-			void previsit( const ast::FunctionDecl * funcDecl );
-
-			void previsit( const ast::BranchStmt * stmt );
-		private:
-			void handleGoto( const ast::BranchStmt * stmt );
-
-			ast::Pass<LabelFinder> & finder;
-			LabelFinder::LabelMap & labelVars;
-			OrderedDeclsStack reverseDeclOrder;
-		};
-
-		class FixInit : public ast::WithStmtsToAdd<> {
-		  public:
-			/// expand each object declaration to use its constructor after it is declared.
-			static void fixInitializers( std::list< ast::ptr<ast::Decl> > &translationUnit );
-
-			const ast::DeclWithType * postvisit( const ast::ObjectDecl *objDecl );
-
-			std::list< ast::ptr< ast::Decl > > staticDtorDecls;
-		};
-
-		struct GenStructMemberCalls final : public ast::WithGuards, public ast::WithShortCircuiting, public ast::WithSymbolTable, public ast::WithVisitorRef<GenStructMemberCalls> {
-			/// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
-			/// for any member that is missing a corresponding ctor/dtor call.
-			/// error if a member is used before constructed
-			static void generate( std::list< ast::ptr<ast::Decl> > & translationUnit );
-
-			void previsit( const ast::FunctionDecl * funcDecl );
-			const ast::DeclWithType * postvisit( const ast::FunctionDecl * funcDecl );
-
-			void previsit( const ast::MemberExpr * memberExpr );
-			void previsit( const ast::ApplicationExpr * appExpr );
-
-			/// Note: this post mutate used to be in a separate visitor. If this pass breaks, one place to examine is whether it is
-			/// okay for this part of the recursion to occur alongside the rest.
-			const ast::Expr * postvisit( const ast::UntypedExpr * expr );
-
-			SemanticErrorException errors;
-		  private:
-			template< typename... Params >
-			void emit( CodeLocation, const Params &... params );
-
-			ast::FunctionDecl * function = nullptr;
-			std::set< const ast::DeclWithType * > unhandled;
-			std::map< const ast::DeclWithType *, CodeLocation > usedUninit;
-			const ast::ObjectDecl * thisParam = nullptr;
-			bool isCtor = false; // true if current function is a constructor
-			const ast::StructDecl * structDecl = nullptr;
-		};
-
-		struct FixCtorExprs final : public ast::WithDeclsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting {
-			/// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
-			static void fix( std::list< ast::ptr<ast::Decl> > & translationUnit );
-
-			const ast::Expr * postvisit( const ast::ConstructorExpr * ctorExpr );
-		};
-
-		struct SplitExpressions : public ast::WithShortCircuiting {
-			/// add CompoundStmts around top-level expressions so that temporaries are destroyed in the correct places.
-			static void split( std::list<ast::ptr<ast::Decl> > & translationUnit );
-
-			ast::Stmt * postvisit( const ast::ExprStmt * stmt );
-			void previsit( const ast::TupleAssignExpr * expr );
-		};
-	} // namespace
-
-	void fix( std::list< ast::ptr<ast::Decl> > & translationUnit, bool inLibrary ) {
-		ast::Pass<SelfAssignChecker> checker;
-		accept_all( translationUnit, checker );
-
-		// fixes StmtExpr to properly link to their resulting expression
-		StmtExprResult::link( translationUnit );
-
-		// fixes ConstructorInit for global variables. should happen before fixInitializers.
-		InitTweak::fixGlobalInit( translationUnit, inLibrary );
-
-		// must happen before ResolveCopyCtors because temporaries have to be inserted into the correct scope
-		SplitExpressions::split( translationUnit );
-
-		InsertImplicitCalls::insert( translationUnit );
-
-		// Needs to happen before ResolveCopyCtors, because argument/return temporaries should not be considered in
-		// error checking branch statements
-		InsertDtors::insert( translationUnit );
-
-		ResolveCopyCtors::resolveImplicitCalls( translationUnit );
-		FixInit::fixInitializers( translationUnit );
-		GenStructMemberCalls::generate( translationUnit );
-
-		// Needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
-		// don't have the correct form, and a member can be constructed more than once.
-		FixCtorExprs::fix( translationUnit );
-	}
-
-	namespace {
-		/// find and return the destructor used in `input`. If `input` is not a simple destructor call, generate a thunk
-		/// that wraps the destructor, insert it into `stmtsToAdd` and return the new function declaration
-		const ast::DeclWithType * getDtorFunc( const ast::ObjectDecl * objDecl, const ast::Stmt * input, std::list< ast::ptr<ast::Stmt> > & stmtsToAdd ) {
-			const CodeLocation loc = input->location;
-			// unwrap implicit statement wrapper
-			// Statement * dtor = input;
-			assert( input );
-			// std::list< const ast::Expr * > matches;
-			auto matches = collectCtorDtorCalls( input );
-
-			if ( dynamic_cast< const ast::ExprStmt * >( input ) ) {
-				// only one destructor call in the expression
-				if ( matches.size() == 1 ) {
-					auto func = getFunction( matches.front() );
-					assertf( func, "getFunction failed to find function in %s", toString( matches.front() ).c_str() );
-
-					// cleanup argument must be a function, not an object (including function pointer)
-					if ( auto dtorFunc = dynamic_cast< const ast::FunctionDecl * > ( func ) ) {
-						if ( dtorFunc->type->forall.empty() ) {
-							// simple case where the destructor is a monomorphic function call - can simply
-							// use that function as the cleanup function.
-							return func;
-						}
+namespace {
+	struct SelfAssignChecker {
+		void previsit( const ast::ApplicationExpr * appExpr );
+	};
+
+	struct StmtExprResult {
+		const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr );
+	};
+
+	/// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
+	/// function calls need their parameters to be copy constructed
+	struct InsertImplicitCalls : public ast::WithConstTypeSubstitution, public ast::WithShortCircuiting {
+		const ast::Expr * postvisit( const ast::ApplicationExpr * appExpr );
+
+		// only handles each UniqueExpr once
+		// if order of visit does not change, this should be safe
+		void previsit (const ast::UniqueExpr *);
+
+		std::unordered_set<decltype(ast::UniqueExpr::id)> visitedIds;
+	};
+
+	/// 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
+	struct ResolveCopyCtors final : public ast::WithGuards, public ast::WithStmtsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting, public ast::WithVisitorRef<ResolveCopyCtors> {
+		const ast::Expr * postvisit( const ast::ImplicitCopyCtorExpr * impCpCtorExpr );
+		const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr );
+		const ast::UniqueExpr * previsit( const ast::UniqueExpr * unqExpr );
+
+		/// handles distant mutations of environment manually.
+		/// WithConstTypeSubstitution cannot remember where the environment is from
+
+		/// MUST be called at start of overload previsit
+		void previsit( const ast::Expr * expr);
+		/// MUST be called at return of overload postvisit
+		const ast::Expr * postvisit(const ast::Expr * expr);
+
+		/// create and resolve ctor/dtor expression: fname(var, [cpArg])
+		const ast::Expr * makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg = nullptr );
+		/// true if type does not need to be copy constructed to ensure correctness
+		bool skipCopyConstruct( const ast::Type * type );
+		ast::ptr< ast::Expr > copyConstructArg( const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal );
+		ast::Expr * destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg );
+	private:
+		/// hack to implement WithTypeSubstitution while conforming to mutation safety.
+		ast::TypeSubstitution * env;
+		bool                    envModified;
+	};
+
+	/// collects constructed object decls - used as a base class
+	struct ObjDeclCollector : public ast::WithGuards, public ast::WithShortCircuiting {
+		// use ordered data structure to maintain ordering for set_difference and for consistent error messages
+		typedef std::list< const ast::ObjectDecl * > ObjectSet;
+		void previsit( const ast::CompoundStmt *compoundStmt );
+		void previsit( const ast::DeclStmt *stmt );
+
+		// don't go into other functions
+		void previsit( const ast::FunctionDecl * ) { visit_children = false; }
+
+	  protected:
+		ObjectSet curVars;
+	};
+
+	// debug
+	template<typename ObjectSet>
+	struct PrintSet {
+		PrintSet( const ObjectSet & objs ) : objs( objs ) {}
+		const ObjectSet & objs;
+	};
+	template<typename ObjectSet>
+	PrintSet<ObjectSet> printSet( const ObjectSet & objs ) { return PrintSet<ObjectSet>( objs ); }
+	template<typename ObjectSet>
+	std::ostream & operator<<( std::ostream & out, const PrintSet<ObjectSet> & set) {
+		out << "{ ";
+		for ( auto & obj : set.objs ) {
+			out << obj->name << ", " ;
+		} // for
+		out << " }";
+		return out;
+	}
+
+	struct LabelFinder final : public ObjDeclCollector {
+		typedef std::map< std::string, ObjectSet > LabelMap;
+		// map of Label -> live variables at that label
+		LabelMap vars;
+
+		typedef ObjDeclCollector Parent;
+		using Parent::previsit;
+		void previsit( const ast::Stmt * stmt );
+
+		void previsit( const ast::CompoundStmt *compoundStmt );
+		void previsit( const ast::DeclStmt *stmt );
+	};
+
+	/// insert destructor calls at the appropriate places.  must happen before CtorInit nodes are removed
+	/// (currently by FixInit)
+	struct InsertDtors final : public ObjDeclCollector, public ast::WithStmtsToAdd<> {
+		typedef std::list< ObjectDecl * > OrderedDecls;
+		typedef std::list< OrderedDecls > OrderedDeclsStack;
+
+		InsertDtors( ast::Pass<LabelFinder> & finder ) : finder( finder ), labelVars( finder.core.vars ) {}
+
+		typedef ObjDeclCollector Parent;
+		using Parent::previsit;
+
+		void previsit( const ast::FunctionDecl * funcDecl );
+
+		void previsit( const ast::BranchStmt * stmt );
+	private:
+		void handleGoto( const ast::BranchStmt * stmt );
+
+		ast::Pass<LabelFinder> & finder;
+		LabelFinder::LabelMap & labelVars;
+		OrderedDeclsStack reverseDeclOrder;
+	};
+
+	/// expand each object declaration to use its constructor after it is declared.
+	struct FixInit : public ast::WithStmtsToAdd<> {
+		static void fixInitializers( std::list< ast::ptr<ast::Decl> > &translationUnit );
+
+		const ast::DeclWithType * postvisit( const ast::ObjectDecl *objDecl );
+
+		std::list< ast::ptr< ast::Decl > > staticDtorDecls;
+	};
+
+	/// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
+	/// for any member that is missing a corresponding ctor/dtor call.
+	/// error if a member is used before constructed
+	struct GenStructMemberCalls final : public ast::WithGuards, public ast::WithShortCircuiting, public ast::WithSymbolTable, public ast::WithVisitorRef<GenStructMemberCalls> {
+		void previsit( const ast::FunctionDecl * funcDecl );
+		const ast::DeclWithType * postvisit( const ast::FunctionDecl * funcDecl );
+
+		void previsit( const ast::MemberExpr * memberExpr );
+		void previsit( const ast::ApplicationExpr * appExpr );
+
+		/// Note: this post mutate used to be in a separate visitor. If this pass breaks, one place to examine is whether it is
+		/// okay for this part of the recursion to occur alongside the rest.
+		const ast::Expr * postvisit( const ast::UntypedExpr * expr );
+
+		SemanticErrorException errors;
+	  private:
+		template< typename... Params >
+		void emit( CodeLocation, const Params &... params );
+
+		ast::FunctionDecl * function = nullptr;
+		std::set< const ast::DeclWithType * > unhandled;
+		std::map< const ast::DeclWithType *, CodeLocation > usedUninit;
+		const ast::ObjectDecl * thisParam = nullptr;
+		bool isCtor = false; // true if current function is a constructor
+		const ast::StructDecl * structDecl = nullptr;
+	};
+
+	/// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
+	struct FixCtorExprs final : public ast::WithDeclsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting {
+		const ast::Expr * postvisit( const ast::ConstructorExpr * ctorExpr );
+	};
+
+	/// add CompoundStmts around top-level expressions so that temporaries are destroyed in the correct places.
+	struct SplitExpressions : public ast::WithShortCircuiting {
+		ast::Stmt * postvisit( const ast::ExprStmt * stmt );
+		void previsit( const ast::TupleAssignExpr * expr );
+	};
+} // namespace
+
+void fix( std::list< ast::ptr<ast::Decl> > & translationUnit, bool inLibrary ) {
+	ast::Pass<SelfAssignChecker>::run( translationUnit );
+
+	// fixes StmtExpr to properly link to their resulting expression
+	ast::Pass<StmtExprResult>::run( translationUnit );
+
+	// fixes ConstructorInit for global variables. should happen before fixInitializers.
+	InitTweak::fixGlobalInit( translationUnit, inLibrary );
+
+	// must happen before ResolveCopyCtors because temporaries have to be inserted into the correct scope
+	ast::Pass<SplitExpressions>::run( translationUnit );
+
+	ast::Pass<InsertImplicitCalls>::run( translationUnit );
+
+	// Needs to happen before ResolveCopyCtors, because argument/return temporaries should not be considered in
+	// error checking branch statements
+	{
+		ast::Pass<LabelFinder> finder;
+		ast::Pass<InsertDtors>::run( translationUnit, finder );
+	}
+
+	ast::Pass<ResolveCopyCtors>::run( translationUnit );
+	FixInit::fixInitializers( translationUnit );
+	ast::Pass<GenStructMemberCalls>::run( translationUnit );
+
+	// Needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
+	// don't have the correct form, and a member can be constructed more than once.
+	ast::Pass<FixCtorExprs>::run( translationUnit );
+}
+
+namespace {
+	/// find and return the destructor used in `input`. If `input` is not a simple destructor call, generate a thunk
+	/// that wraps the destructor, insert it into `stmtsToAdd` and return the new function declaration
+	const ast::DeclWithType * getDtorFunc( const ast::ObjectDecl * objDecl, const ast::Stmt * input, std::list< ast::ptr<ast::Stmt> > & stmtsToAdd ) {
+		const CodeLocation loc = input->location;
+		// unwrap implicit statement wrapper
+		// Statement * dtor = input;
+		assert( input );
+		// std::list< const ast::Expr * > matches;
+		auto matches = collectCtorDtorCalls( input );
+
+		if ( dynamic_cast< const ast::ExprStmt * >( input ) ) {
+			// only one destructor call in the expression
+			if ( matches.size() == 1 ) {
+				auto func = getFunction( matches.front() );
+				assertf( func, "getFunction failed to find function in %s", toString( matches.front() ).c_str() );
+
+				// cleanup argument must be a function, not an object (including function pointer)
+				if ( auto dtorFunc = dynamic_cast< const ast::FunctionDecl * > ( func ) ) {
+					if ( dtorFunc->type->forall.empty() ) {
+						// simple case where the destructor is a monomorphic function call - can simply
+						// use that function as the cleanup function.
+						return func;
 					}
 				}
 			}
-
-			// otherwise the cleanup is more complicated - need to build a single argument cleanup function that
-			// wraps the more complicated code.
-			static UniqueName dtorNamer( "__cleanup_dtor" );
-			std::string name = dtorNamer.newName();
-			ast::FunctionDecl * dtorFunc = SymTab::genDefaultFunc( loc, name, objDecl->type->stripReferences(), false );
-			stmtsToAdd.push_back( new ast::DeclStmt(loc, dtorFunc ) );
-
-			// the original code contains uses of objDecl - replace them with the newly generated 'this' parameter.
-			const ast::ObjectDecl * thisParam = getParamThis( dtorFunc );
-			const ast::Expr * replacement = new ast::VariableExpr( loc, thisParam );
-
-			auto base = replacement->result->stripReferences();
-			if ( dynamic_cast< const ast::ArrayType * >( base ) || dynamic_cast< const ast::TupleType * > ( base ) ) {
-				// need to cast away reference for array types, since the destructor is generated without the reference type,
-				// and for tuple types since tuple indexing does not work directly on a reference
-				replacement = new ast::CastExpr( replacement, base );
-			}
-			auto dtor = ast::DeclReplacer::replace( input, ast::DeclReplacer::ExprMap{ std::make_pair( objDecl, replacement ) } );
-			auto mutStmts = dtorFunc->stmts.get_and_mutate();
-			mutStmts->push_back(strict_dynamic_cast<const ast::Stmt *>( dtor ));
-			dtorFunc->stmts = mutStmts;
-
-			return dtorFunc;
-		}
-
-		void StmtExprResult::link( std::list<ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<StmtExprResult> linker;
-			accept_all( translationUnit, linker );
-		}
-
-		void SplitExpressions::split( std::list<ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<SplitExpressions> splitter;
-			accept_all( translationUnit, splitter );
-		}
-
-		void InsertImplicitCalls::insert( std::list<ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<InsertImplicitCalls> inserter;
-			accept_all( translationUnit, inserter );
-		}
-
-		void ResolveCopyCtors::resolveImplicitCalls( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<ResolveCopyCtors> resolver;
-			accept_all( translationUnit, resolver );
-		}
-
-		void FixInit::fixInitializers( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<FixInit> fixer;
-
-			// can't use mutateAll, because need to insert declarations at top-level
-			// can't use DeclMutator, because sometimes need to insert IfStmt, etc.
-			SemanticErrorException errors;
-			for ( auto i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
-				try {
-					// maybeAccept( *i, fixer ); translationUnit should never contain null
-					*i = (*i)->accept(fixer);
-					translationUnit.splice( i, fixer.core.staticDtorDecls );
-				} catch( SemanticErrorException &e ) {
-					errors.append( e );
-				} // try
-			} // for
-			if ( ! errors.isEmpty() ) {
-				throw errors;
+		}
+
+		// otherwise the cleanup is more complicated - need to build a single argument cleanup function that
+		// wraps the more complicated code.
+		static UniqueName dtorNamer( "__cleanup_dtor" );
+		std::string name = dtorNamer.newName();
+		ast::FunctionDecl * dtorFunc = SymTab::genDefaultFunc( loc, name, objDecl->type->stripReferences(), false );
+		stmtsToAdd.push_back( new ast::DeclStmt(loc, dtorFunc ) );
+
+		// the original code contains uses of objDecl - replace them with the newly generated 'this' parameter.
+		const ast::ObjectDecl * thisParam = getParamThis( dtorFunc );
+		const ast::Expr * replacement = new ast::VariableExpr( loc, thisParam );
+
+		auto base = replacement->result->stripReferences();
+		if ( dynamic_cast< const ast::ArrayType * >( base ) || dynamic_cast< const ast::TupleType * > ( base ) ) {
+			// need to cast away reference for array types, since the destructor is generated without the reference type,
+			// and for tuple types since tuple indexing does not work directly on a reference
+			replacement = new ast::CastExpr( replacement, base );
+		}
+		auto dtor = ast::DeclReplacer::replace( input, ast::DeclReplacer::ExprMap{ std::make_pair( objDecl, replacement ) } );
+		auto mutStmts = dtorFunc->stmts.get_and_mutate();
+		mutStmts->push_back(strict_dynamic_cast<const ast::Stmt *>( dtor ));
+		dtorFunc->stmts = mutStmts;
+
+		return dtorFunc;
+	}
+
+	void FixInit::fixInitializers( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
+		ast::Pass<FixInit> fixer;
+
+		// can't use mutateAll, because need to insert declarations at top-level
+		// can't use DeclMutator, because sometimes need to insert IfStmt, etc.
+		SemanticErrorException errors;
+		for ( auto i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
+			try {
+				// maybeAccept( *i, fixer ); translationUnit should never contain null
+				*i = (*i)->accept(fixer);
+				translationUnit.splice( i, fixer.core.staticDtorDecls );
+			} catch( SemanticErrorException &e ) {
+				errors.append( e );
+			} // try
+		} // for
+		if ( ! errors.isEmpty() ) {
+			throw errors;
+		} // if
+	}
+
+	const ast::StmtExpr * StmtExprResult::previsit( const ast::StmtExpr * stmtExpr ) {
+		// we might loose the result expression here so add a pointer to trace back
+		assert( stmtExpr->result );
+		const ast::Type * result = stmtExpr->result;
+		if ( ! result->isVoid() ) {
+			auto mutExpr = mutate(stmtExpr);
+			const ast::CompoundStmt * body = mutExpr->stmts;
+			assert( ! body->kids.empty() );
+			mutExpr->resultExpr = body->kids.back().strict_as<ast::ExprStmt>();
+			return mutExpr;
+		}
+		return stmtExpr;
+	}
+
+	ast::Stmt * SplitExpressions::postvisit( const ast::ExprStmt * stmt ) {
+		// wrap each top-level ExprStmt in a block so that destructors for argument and return temporaries are destroyed
+		// in the correct places
+		ast::CompoundStmt * ret = new ast::CompoundStmt( stmt->location, { stmt } );
+		return ret;
+	}
+
+	void SplitExpressions::previsit( const ast::TupleAssignExpr * ) {
+		// don't do this within TupleAssignExpr, since it is already broken up into multiple expressions
+		visit_children = false;
+	}
+
+	// Relatively simple structural comparison for expressions, needed to determine
+	// if two expressions are "the same" (used to determine if self assignment occurs)
+	struct StructuralChecker {
+		// Strip all casts and then dynamic_cast.
+		template<typename T>
+		static const T * cast( const ast::Expr * expr ) {
+			// this might be too permissive. It's possible that only particular casts are relevant.
+			while ( auto cast = dynamic_cast< const ast::CastExpr * >( expr ) ) {
+				expr = cast->arg;
+			}
+			return dynamic_cast< const T * >( expr );
+		}
+
+		void previsit( const ast::Expr * ) {
+			// anything else does not qualify
+			result = false;
+		}
+
+		// ignore casts
+		void previsit( const ast::CastExpr * ) {}
+
+		void previsit( const ast::MemberExpr * memExpr ) {
+			if ( auto otherMember = cast< ast::MemberExpr >( other ) ) {
+				if ( otherMember->member == memExpr->member ) {
+					other = otherMember->aggregate;
+					return;
+				}
+			}
+			result = false;
+		}
+
+		void previsit( const ast::VariableExpr * varExpr ) {
+			if ( auto otherVar = cast< ast::VariableExpr >( other ) ) {
+				if ( otherVar->var == varExpr->var ) {
+					return;
+				}
+			}
+			result = false;
+		}
+
+		void previsit( const ast::AddressExpr * ) {
+			if ( auto addrExpr = cast< ast::AddressExpr >( other ) ) {
+				other = addrExpr->arg;
+				return;
+			}
+			result = false;
+		}
+
+		const ast::Expr * other;
+		bool result = true;
+		StructuralChecker( const ast::Expr * other ) : other(other) {}
+	};
+
+	bool structurallySimilar( const ast::Expr * e1, const ast::Expr * e2 ) {
+		return ast::Pass<StructuralChecker>::read( e1, e2 );
+	}
+
+	void SelfAssignChecker::previsit( const ast::ApplicationExpr * appExpr ) {
+		auto function = getFunction( appExpr );
+		if ( function->name == "?=?" ) { // doesn't use isAssignment, because ?+=?, etc. should not count as self-assignment
+			if ( appExpr->args.size() == 2 ) {
+				// check for structural similarity (same variable use, ignore casts, etc. - but does not look too deeply, anything looking like a function is off limits)
+				if ( structurallySimilar( appExpr->args.front(), appExpr->args.back() ) ) {
+					SemanticWarning( appExpr->location, Warning::SelfAssignment, toCString( appExpr->args.front() ) );
+				}
+			}
+		}
+	}
+
+	const ast::Expr * InsertImplicitCalls::postvisit( const ast::ApplicationExpr * appExpr ) {
+		if ( auto function = appExpr->func.as<ast::VariableExpr>() ) {
+			if ( function->var->linkage.is_builtin ) {
+				// optimization: don't need to copy construct in order to call intrinsic functions
+				return appExpr;
+			} else if ( auto funcDecl = function->var.as<ast::DeclWithType>() ) {
+				auto ftype = dynamic_cast< const ast::FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
+				assertf( ftype, "Function call without function type: %s", toString( funcDecl ).c_str() );
+				if ( CodeGen::isConstructor( funcDecl->name ) && ftype->params.size() == 2 ) {
+					auto t1 = getPointerBase( ftype->params.front() );
+					auto t2 = ftype->params.back();
+					assert( t1 );
+
+					if ( ResolvExpr::typesCompatible( t1, t2 ) ) {
+						// optimization: don't need to copy construct in order to call a copy constructor
+						return appExpr;
+					} // if
+				} else if ( CodeGen::isDestructor( funcDecl->name ) ) {
+					// correctness: never copy construct arguments to a destructor
+					return appExpr;
+				} // if
 			} // if
-		}
-
-		void InsertDtors::insert( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<LabelFinder> finder;
-			ast::Pass<InsertDtors> inserter( finder );
-			accept_all( translationUnit, inserter );
-		}
-
-		void GenStructMemberCalls::generate( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<GenStructMemberCalls> warner;
-			accept_all( translationUnit, warner );
-		}
-
-		void FixCtorExprs::fix( std::list< ast::ptr<ast::Decl> > & translationUnit ) {
-			ast::Pass<FixCtorExprs> fixer;
-			accept_all( translationUnit, fixer );
-		}
-
-		const ast::StmtExpr * StmtExprResult::previsit( const ast::StmtExpr * stmtExpr ) {
-			// we might loose the result expression here so add a pointer to trace back
-			assert( stmtExpr->result );
-			const ast::Type * result = stmtExpr->result;
-			if ( ! result->isVoid() ) {
-				auto mutExpr = mutate(stmtExpr);
-				const ast::CompoundStmt * body = mutExpr->stmts;
-				assert( ! body->kids.empty() );
-				mutExpr->resultExpr = body->kids.back().strict_as<ast::ExprStmt>();
+		} // 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
+		ast::ptr<ast::TypeSubstitution> tmp = appExpr->env;
+		auto mutExpr = mutate(appExpr);
+		mutExpr->env = nullptr;
+
+		auto expr = new ast::ImplicitCopyCtorExpr( appExpr->location, mutExpr );
+		// Move the type substitution to the new top-level, if it is attached to the appExpr.
+		// 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.
+		assert( typeSubs );
+		// assert (mutExpr->env);
+		expr->env = tmp;
+		// mutExpr->env = nullptr;
+		//std::swap( expr->env, appExpr->env );
+		return expr;
+	}
+
+	void ResolveCopyCtors::previsit(const ast::Expr * expr) {
+		if (expr->env) {
+			GuardValue(env);
+			GuardValue(envModified);
+			env = expr->env->clone();
+			envModified = false;
+		}
+	}
+
+	const ast::Expr * ResolveCopyCtors::postvisit(const ast::Expr * expr) {
+		if (expr->env) {
+			if (envModified) {
+				auto mutExpr = mutate(expr);
+				mutExpr->env = env;
 				return mutExpr;
 			}
-			return stmtExpr;
-		}
-
-		ast::Stmt * SplitExpressions::postvisit( const ast::ExprStmt * stmt ) {
-			// wrap each top-level ExprStmt in a block so that destructors for argument and return temporaries are destroyed
-			// in the correct places
-			ast::CompoundStmt * ret = new ast::CompoundStmt( stmt->location, { stmt } );
-			return ret;
-		}
-
-		void SplitExpressions::previsit( const ast::TupleAssignExpr * ) {
-			// don't do this within TupleAssignExpr, since it is already broken up into multiple expressions
-			visit_children = false;
-		}
-
-		// Relatively simple structural comparison for expressions, needed to determine
-		// if two expressions are "the same" (used to determine if self assignment occurs)
-		struct StructuralChecker {
-			const ast::Expr * stripCasts( const ast::Expr * expr ) {
-				// this might be too permissive. It's possible that only particular casts are relevant.
-				while ( auto cast = dynamic_cast< const ast::CastExpr * >( expr ) ) {
-					expr = cast->arg;
+			else {
+				// env was not mutated, skip and delete the shallow copy
+				delete env;
+				return expr;
+			}
+		}
+		else {
+			return expr;
+		}
+	}
+
+	bool ResolveCopyCtors::skipCopyConstruct( const ast::Type * type ) { return ! isConstructable( type ); }
+
+	const ast::Expr * ResolveCopyCtors::makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg ) {
+		assert( var );
+		assert (var->isManaged());
+		assert (!cpArg || cpArg->isManaged());
+		// arrays are not copy constructed, so this should always be an ExprStmt
+		ast::ptr< ast::Stmt > stmt = genCtorDtor(var->location, fname, var, cpArg );
+		assertf( stmt, "ResolveCopyCtors: genCtorDtor returned nullptr: %s / %s / %s", fname.c_str(), toString( var ).c_str(), toString( cpArg ).c_str() );
+		auto exprStmt = stmt.strict_as<ast::ImplicitCtorDtorStmt>()->callStmt.strict_as<ast::ExprStmt>();
+		ast::ptr<ast::Expr> untyped = exprStmt->expr; // take ownership of expr
+		// exprStmt->expr = nullptr;
+
+		// 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; )
+		ast::ptr<ast::Expr> resolved = ResolvExpr::findVoidExpression(untyped, symtab);
+		assert( resolved );
+		if ( resolved->env ) {
+			// Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
+			env->add( *resolved->env );
+			envModified = true;
+			// delete resolved->env;
+			auto mut = mutate(resolved.get());
+			assertf(mut == resolved.get(), "newly resolved expression must be unique");
+			mut->env = nullptr;
+		} // if
+		// delete stmt;
+		if ( auto assign = resolved.as<ast::TupleAssignExpr>() ) {
+			// fix newly generated StmtExpr
+			previsit( assign->stmtExpr );
+		}
+		return resolved.release();
+	}
+
+	ast::ptr<ast::Expr> ResolveCopyCtors::copyConstructArg(
+		const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal )
+	{
+		static UniqueName tempNamer("_tmp_cp");
+		assert( env );
+		const CodeLocation loc = impCpCtorExpr->location;
+		// CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
+		assert( arg->result );
+		ast::ptr<ast::Type> result = arg->result;
+		if ( skipCopyConstruct( result ) ) return arg; // skip certain non-copyable types
+
+		// type may involve type variables, so apply type substitution to get temporary variable's actual type,
+		// since result type may not be substituted (e.g., if the type does not appear in the parameter list)
+		// Use applyFree so that types bound in function pointers are not substituted, e.g. in forall(dtype T) void (*)(T).
+
+		// xxx - this originally mutates arg->result in place. is it correct?
+		result = env->applyFree( result.get() ).node;
+		auto mutResult = result.get_and_mutate();
+		mutResult->set_const(false);
+
+		auto mutArg = mutate(arg);
+		mutArg->result = mutResult;
+
+		ast::ptr<ast::Expr> guard = mutArg;
+
+		ast::ptr<ast::ObjectDecl> tmp = new ast::ObjectDecl({}, "__tmp", mutResult, nullptr );
+
+		// create and resolve copy constructor
+		CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
+		auto cpCtor = makeCtorDtor( "?{}", tmp, mutArg );
+
+		if ( auto appExpr = dynamic_cast< const ast::ApplicationExpr * >( cpCtor ) ) {
+			// if the chosen constructor is intrinsic, the copy is unnecessary, so
+			// don't create the temporary and don't call the copy constructor
+			auto function = appExpr->func.strict_as<ast::VariableExpr>();
+			if ( function->var->linkage == ast::Linkage::Intrinsic ) {
+				// arguments that need to be boxed need a temporary regardless of whether the copy constructor is intrinsic,
+				// so that the object isn't changed inside of the polymorphic function
+				if ( ! GenPoly::needsBoxing( formal, result, impCpCtorExpr->callExpr, env ) ) {
+					// xxx - should arg->result be mutated? see comment above.
+					return guard;
 				}
-				return expr;
-			}
-
-			void previsit( const ast::Expr * ) {
-				// anything else does not qualify
-				isSimilar = false;
-			}
-
-			template<typename T>
-			T * cast( const ast::Expr * node ) {
-				// all expressions need to ignore casts, so this bit has been factored out
-				return dynamic_cast< T * >( stripCasts( node ) );
-			}
-
-			// ignore casts
-			void previsit( const ast::CastExpr * ) {}
-
-			void previsit( const ast::MemberExpr * memExpr ) {
-				if ( auto otherMember = cast< const ast::MemberExpr >( other ) ) {
-					if ( otherMember->member == memExpr->member ) {
-						other = otherMember->aggregate;
-						return;
+			}
+		}
+
+		// set a unique name for the temporary once it's certain the call is necessary
+		auto mut = tmp.get_and_mutate();
+		assertf (mut == tmp, "newly created ObjectDecl must be unique");
+		mut->name = tempNamer.newName();
+
+		// replace argument to function call with temporary
+		stmtsToAddBefore.push_back( new ast::DeclStmt(loc, tmp ) );
+		arg = cpCtor;
+		return destructRet( tmp, arg );
+
+		// impCpCtorExpr->dtors.push_front( makeCtorDtor( "^?{}", tmp ) );
+	}
+
+	ast::Expr * ResolveCopyCtors::destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ) {
+		// TODO: refactor code for generating cleanup attribute, since it's common and reused in ~3-4 places
+		// check for existing cleanup attribute before adding another(?)
+		// need to add __Destructor for _tmp_cp variables as well
+
+		assertf( ast::dtorStruct && ast::dtorStruct->members.size() == 2, "Destructor generation requires __Destructor definition." );
+		assertf( ast::dtorStructDestroy, "Destructor generation requires __destroy_Destructor." );
+
+		const CodeLocation loc = ret->location;
+
+		// generate a __Destructor for ret that calls the destructor
+		auto res = makeCtorDtor( "^?{}", ret );
+		auto dtor = mutate(res);
+
+		// if the chosen destructor is intrinsic, elide the generated dtor handler
+		if ( arg && isIntrinsicCallExpr( dtor ) ) {
+			return new ast::CommaExpr(loc, arg, new ast::VariableExpr(loc, ret ) );
+			// return;
+		}
+
+		if ( ! dtor->env ) dtor->env = maybeClone( env );
+		auto dtorFunc = getDtorFunc( ret, new ast::ExprStmt(loc, dtor ), stmtsToAddBefore );
+
+		auto dtorStructType = new ast::StructInstType(ast::dtorStruct);
+
+		// what does this do???
+		dtorStructType->params.push_back( new ast::TypeExpr(loc, new ast::VoidType() ) );
+
+		// cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings
+		auto dtorFtype = new ast::FunctionType();
+		dtorFtype->params.push_back( new ast::PointerType(new ast::VoidType( ) ) );
+		auto dtorType = new ast::PointerType( dtorFtype );
+
+		static UniqueName namer( "_ret_dtor" );
+		auto retDtor = new ast::ObjectDecl(loc, namer.newName(), dtorStructType, new ast::ListInit(loc, { new ast::SingleInit(loc, ast::ConstantExpr::null(loc) ), new ast::SingleInit(loc, new ast::CastExpr( new ast::VariableExpr(loc, dtorFunc ), dtorType ) ) } ) );
+		retDtor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, ast::dtorStructDestroy ) } ) );
+		stmtsToAddBefore.push_back( new ast::DeclStmt(loc, retDtor ) );
+
+		if ( arg ) {
+			auto member = new ast::MemberExpr(loc, ast::dtorStruct->members.front().strict_as<ast::DeclWithType>(), new ast::VariableExpr(loc, retDtor ) );
+			auto object = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, ret ) ), new ast::PointerType(new ast::VoidType() ) );
+			ast::Expr * assign = createBitwiseAssignment( member, object );
+			return new ast::CommaExpr(loc, new ast::CommaExpr(loc, arg, assign ), new ast::VariableExpr(loc, ret ) );
+		}
+		return nullptr;
+		// impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
+	}
+
+	const ast::Expr * ResolveCopyCtors::postvisit( const ast::ImplicitCopyCtorExpr *impCpCtorExpr ) {
+		CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
+
+		ast::ApplicationExpr * appExpr = mutate(impCpCtorExpr->callExpr.get());
+		const ast::ObjectDecl * returnDecl = nullptr;
+		const CodeLocation loc = appExpr->location;
+
+		// take each argument and attempt to copy construct it.
+		auto ftype = GenPoly::getFunctionType( appExpr->func->result );
+		assert( ftype );
+		auto & params = ftype->params;
+		auto iter = params.begin();
+		for ( auto & arg : appExpr->args ) {
+			const ast::Type * formal = nullptr;
+			if ( iter != params.end() ) { // does not copy construct C-style variadic arguments
+				// DeclarationWithType * param = *iter++;
+				formal = *iter++;
+			}
+
+			arg = copyConstructArg( arg, impCpCtorExpr, formal );
+		} // 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 named return values?
+		const ast::Type * result = appExpr->result;
+		if ( ! result->isVoid() ) {
+			static UniqueName retNamer("_tmp_cp_ret");
+			// result = result->clone();
+			auto subResult = env->apply( result ).node;
+			auto ret = new ast::ObjectDecl(loc, retNamer.newName(), subResult, nullptr );
+			auto mutType = mutate(ret->type.get());
+			mutType->set_const( false );
+			ret->type = mutType;
+			returnDecl = ret;
+			stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) );
+			CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
+		} // for
+		CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
+		// ------------------------------------------------------
+
+		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
+
+		// xxx - actual env might be somewhere else, need to keep invariant
+
+		// deletion of wrapper should be handled by pass template now
+
+		// impCpCtorExpr->callExpr = nullptr;
+		assert (appExpr->env == nullptr);
+		appExpr->env = impCpCtorExpr->env;
+		// std::swap( impCpCtorExpr->env, appExpr->env );
+		// assert( impCpCtorExpr->env == nullptr );
+		// delete impCpCtorExpr;
+
+		if ( returnDecl ) {
+			ast::Expr * assign = createBitwiseAssignment( new ast::VariableExpr(loc, returnDecl ), appExpr );
+			if ( ! dynamic_cast< const ast::ReferenceType * >( result ) ) {
+				// destructing reference returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
+				assign = destructRet( returnDecl, assign );
+				assert(assign);
+			} else {
+				assign = new ast::CommaExpr(loc, assign, new ast::VariableExpr(loc, returnDecl ) );
+			}
+			// move env from appExpr to retExpr
+			// std::swap( assign->env, appExpr->env );
+			assign->env = appExpr->env;
+			// actual env is handled by common routine that replaces WithTypeSubstitution
+			return postvisit((const ast::Expr *)assign);
+		} else {
+			return postvisit((const ast::Expr *)appExpr);
+		} // if
+	}
+
+	const ast::StmtExpr * ResolveCopyCtors::previsit( const ast::StmtExpr * _stmtExpr ) {
+		// function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression,
+		// since temporaries can be shared across sub-expressions, e.g.
+		//   [A, A] f();       // decl
+		//   g([A] x, [A] y);  // decl
+		//   g(f());           // call
+		// f is executed once, so the return temporary is shared across the tuple constructors for x and y.
+		// Explicitly mutating children instead of mutating the inner compound statement forces the temporaries to be added
+		// to the outer context, rather than inside of the statement expression.
+
+		// call the common routine that replaces WithTypeSubstitution
+		previsit((const ast::Expr *) _stmtExpr);
+
+		visit_children = false;
+		const CodeLocation loc = _stmtExpr->location;
+
+		assert( env );
+
+		symtab.enterScope();
+		// visit all statements
+		auto stmtExpr = mutate(_stmtExpr);
+		auto mutStmts = mutate(stmtExpr->stmts.get());
+
+		auto & stmts = mutStmts->kids;
+		for ( auto & stmt : stmts ) {
+			stmt = stmt->accept( *visitor );
+		} // for
+		stmtExpr->stmts = mutStmts;
+		symtab.leaveScope();
+
+		assert( stmtExpr->result );
+		// const ast::Type * result = stmtExpr->result;
+		if ( ! stmtExpr->result->isVoid() ) {
+			static UniqueName retNamer("_tmp_stmtexpr_ret");
+
+			// result = result->clone();
+			auto result = env->apply( stmtExpr->result.get() ).node;
+			if ( ! InitTweak::isConstructable( result ) ) {
+				// delete result;
+				return stmtExpr;
+			}
+			auto mutResult = result.get_and_mutate();
+			mutResult->set_const(false);
+
+			// create variable that will hold the result of the stmt expr
+			auto ret = new ast::ObjectDecl(loc, retNamer.newName(), mutResult, nullptr );
+			stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) );
+
+			assertf(
+				stmtExpr->resultExpr,
+				"Statement-Expression should have a resulting expression at %s:%d",
+				stmtExpr->location.filename.c_str(),
+				stmtExpr->location.first_line
+			);
+
+			const ast::ExprStmt * last = stmtExpr->resultExpr;
+			// xxx - if this is non-unique, need to copy while making resultExpr ref
+			assertf(last->unique(), "attempt to modify weakly shared statement");
+			auto mutLast = mutate(last);
+			// above assertion means in-place mutation is OK
+			try {
+				mutLast->expr = makeCtorDtor( "?{}", ret, mutLast->expr );
+			} catch(...) {
+				std::cerr << "*CFA internal error: ";
+				std::cerr << "can't resolve implicit constructor";
+				std::cerr << " at " << stmtExpr->location.filename;
+				std::cerr << ":" << stmtExpr->location.first_line << std::endl;
+
+				abort();
+			}
+
+			// add destructors after current statement
+			stmtsToAddAfter.push_back( new ast::ExprStmt(loc, makeCtorDtor( "^?{}", ret ) ) );
+
+			// must have a non-empty body, otherwise it wouldn't have a result
+			assert( ! stmts.empty() );
+
+			// if there is a return decl, add a use as the last statement; will not have return decl on non-constructable returns
+			stmts.push_back( new ast::ExprStmt(loc, new ast::VariableExpr(loc, ret ) ) );
+		} // if
+
+		assert( stmtExpr->returnDecls.empty() );
+		assert( stmtExpr->dtors.empty() );
+
+		return stmtExpr;
+	}
+
+	// to prevent warnings ('_unq0' may be used uninitialized in this function),
+	// insert an appropriate zero initializer for UniqueExpr temporaries.
+	ast::Init * makeInit( const ast::Type * t ) {
+		if ( auto inst = dynamic_cast< const ast::StructInstType * >( t ) ) {
+			// initizer for empty struct must be empty
+			if ( inst->base->members.empty() ) return new ast::ListInit({}, {});
+		} else if ( auto inst = dynamic_cast< const ast::UnionInstType * >( t ) ) {
+			// initizer for empty union must be empty
+			if ( inst->base->members.empty() ) return new ast::ListInit({}, {});
+		}
+
+		return new ast::ListInit( {}, { new ast::SingleInit( {}, ast::ConstantExpr::from_int({}, 0) ) } );
+	}
+
+	const ast::UniqueExpr * ResolveCopyCtors::previsit( const ast::UniqueExpr * unqExpr ) {
+		visit_children = false;
+		// xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
+		static std::unordered_map< int, const ast::UniqueExpr * > unqMap;
+		auto mutExpr = mutate(unqExpr);
+		if ( ! unqMap.count( unqExpr->id ) ) {
+			// resolve expr and find its
+
+			auto impCpCtorExpr = mutExpr->expr.as<ast::ImplicitCopyCtorExpr>();
+			// PassVisitor<ResolveCopyCtors> fixer;
+
+			mutExpr->expr = mutExpr->expr->accept( *visitor );
+			// it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
+			assert( unqExpr->result );
+			if ( impCpCtorExpr ) {
+				auto comma = unqExpr->expr.strict_as<ast::CommaExpr>();
+				auto var = comma->arg2.strict_as<ast::VariableExpr>();
+				// note the variable used as the result from the call
+				mutExpr->var = var;
+			} else {
+				// expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
+				mutExpr->object = new ast::ObjectDecl( mutExpr->location, toString("_unq", mutExpr->id), mutExpr->result, makeInit( mutExpr->result ) );
+				mutExpr->var = new ast::VariableExpr( mutExpr->location, mutExpr->object );
+			}
+
+			// stmtsToAddBefore.splice( stmtsToAddBefore.end(), fixer.pass.stmtsToAddBefore );
+			// stmtsToAddAfter.splice( stmtsToAddAfter.end(), fixer.pass.stmtsToAddAfter );
+			unqMap[mutExpr->id] = mutExpr;
+		} else {
+			// take data from other UniqueExpr to ensure consistency
+			// delete unqExpr->get_expr();
+			mutExpr->expr = unqMap[mutExpr->id]->expr;
+			// delete unqExpr->result;
+			mutExpr->result = mutExpr->expr->result;
+		}
+		return mutExpr;
+	}
+
+	const ast::DeclWithType * FixInit::postvisit( const ast::ObjectDecl *_objDecl ) {
+		const CodeLocation loc = _objDecl->location;
+
+		// since this removes the init field from objDecl, it must occur after children are mutated (i.e. postvisit)
+		if ( ast::ptr<ast::ConstructorInit> ctorInit = _objDecl->init.as<ast::ConstructorInit>() ) {
+			auto objDecl = mutate(_objDecl);
+
+			// could this be non-unique?
+			if (objDecl != _objDecl) {
+				std::cerr << "FixInit: non-unique object decl " << objDecl->location << objDecl->name << std::endl;
+			}
+			// a decision should have been made by the resolver, so ctor and init are not both non-NULL
+			assert( ! ctorInit->ctor || ! ctorInit->init );
+			if ( const ast::Stmt * ctor = ctorInit->ctor ) {
+				if ( objDecl->storage.is_static ) {
+					// originally wanted to take advantage of gcc nested functions, but
+					// we get memory errors with this approach. To remedy this, the static
+					// variable is hoisted when the destructor needs to be called.
+					//
+					// generate:
+					// static T __objName_static_varN;
+					// void __objName_dtor_atexitN() {
+					//   __dtor__...;
+					// }
+					// int f(...) {
+					//   ...
+					//   static bool __objName_uninitialized = true;
+					//   if (__objName_uninitialized) {
+					//     __ctor(__objName);
+					//     __objName_uninitialized = false;
+					//     atexit(__objName_dtor_atexitN);
+					//   }
+					//   ...
+					// }
+
+					static UniqueName dtorCallerNamer( "_dtor_atexit" );
+
+					// static bool __objName_uninitialized = true
+					auto boolType = new ast::BasicType( ast::BasicType::Kind::Bool );
+					auto boolInitExpr = new ast::SingleInit(loc, ast::ConstantExpr::from_int(loc, 1 ) );
+					auto isUninitializedVar = new ast::ObjectDecl(loc, objDecl->mangleName + "_uninitialized", boolType, boolInitExpr, ast::Storage::Static, ast::Linkage::Cforall);
+					isUninitializedVar->fixUniqueId();
+
+					// __objName_uninitialized = false;
+					auto setTrue = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ) );
+					setTrue->args.push_back( new ast::VariableExpr(loc, isUninitializedVar ) );
+					setTrue->args.push_back( ast::ConstantExpr::from_int(loc, 0 ) );
+
+					// generate body of if
+					auto initStmts = new ast::CompoundStmt(loc);
+					auto & body = initStmts->kids;
+					body.push_back( ctor );
+					body.push_back( new ast::ExprStmt(loc, setTrue ) );
+
+					// put it all together
+					auto ifStmt = new ast::IfStmt(loc, new ast::VariableExpr(loc, isUninitializedVar ), initStmts, 0 );
+					stmtsToAddAfter.push_back( new ast::DeclStmt(loc, isUninitializedVar ) );
+					stmtsToAddAfter.push_back( ifStmt );
+
+					const ast::Stmt * dtor = ctorInit->dtor;
+
+					// these should be automatically managed once reassigned
+					// objDecl->set_init( nullptr );
+					// ctorInit->set_ctor( nullptr );
+					// ctorInit->set_dtor( nullptr );
+					if ( dtor ) {
+						// if the object has a non-trivial destructor, have to
+						// hoist it and the object into the global space and
+						// call the destructor function with atexit.
+
+						// Statement * dtorStmt = dtor->clone();
+
+						// void __objName_dtor_atexitN(...) {...}
+						ast::FunctionDecl * dtorCaller = new ast::FunctionDecl(loc, objDecl->mangleName + dtorCallerNamer.newName(), {}, {}, {}, new ast::CompoundStmt(loc, {dtor}), ast::Storage::Static, ast::Linkage::C );
+						dtorCaller->fixUniqueId();
+						// dtorCaller->stmts->push_back( dtor );
+
+						// atexit(dtor_atexit);
+						auto callAtexit = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "atexit" ) );
+						callAtexit->args.push_back( new ast::VariableExpr(loc, dtorCaller ) );
+
+						body.push_back( new ast::ExprStmt(loc, callAtexit ) );
+
+						// hoist variable and dtor caller decls to list of decls that will be added into global scope
+						staticDtorDecls.push_back( objDecl );
+						staticDtorDecls.push_back( dtorCaller );
+
+						// need to rename object uniquely since it now appears
+						// at global scope and there could be multiple function-scoped
+						// static variables with the same name in different functions.
+						// Note: it isn't sufficient to modify only the mangleName, because
+						// then subsequent Indexer passes can choke on seeing the object's name
+						// if another object has the same name and type. An unfortunate side-effect
+						// of renaming the object is that subsequent NameExprs may fail to resolve,
+						// but there shouldn't be any remaining past this point.
+						static UniqueName staticNamer( "_static_var" );
+						objDecl->name = objDecl->name + staticNamer.newName();
+						objDecl->mangleName = Mangle::mangle( objDecl );
+
+						// xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
+						// create a new object which is never used
+						static UniqueName dummyNamer( "_dummy" );
+						auto dummy = new ast::ObjectDecl(loc, dummyNamer.newName(), new ast::PointerType(new ast::VoidType()), nullptr, ast::Storage::Static, ast::Linkage::Cforall, 0, { new ast::Attribute("unused") } );
+						// delete ctorInit;
+						return dummy;
+					} else {
+						objDecl->init = nullptr;
+						return objDecl;
+					}
+				} else {
+					auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * > ( ctor );
+					auto ctorStmt = implicit->callStmt.as<ast::ExprStmt>();
+					const ast::ApplicationExpr * ctorCall = nullptr;
+					if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->expr )) && ctorCall->args.size() == 2 ) {
+						// clean up intrinsic copy constructor calls by making them into SingleInits
+						const ast::Expr * ctorArg = ctorCall->args.back();
+						// ctorCall should be gone afterwards
+						auto mutArg = mutate(ctorArg);
+						mutArg->env = ctorCall->env;
+						// std::swap( ctorArg->env, ctorCall->env );
+						objDecl->init = new ast::SingleInit(loc, mutArg );
+
+						// ctorCall->args.pop_back();
+					} else {
+						stmtsToAddAfter.push_back( ctor );
+						objDecl->init = nullptr;
+						// ctorInit->ctor = nullptr;
+					}
+
+					const ast::Stmt * dtor = ctorInit->dtor;
+					if ( dtor ) {
+						auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * >( dtor );
+						const ast::Stmt * dtorStmt = implicit->callStmt;
+
+						// don't need to call intrinsic dtor, because it does nothing, but
+						// non-intrinsic dtors must be called
+						if ( ! isIntrinsicSingleArgCallStmt( dtorStmt ) ) {
+							// set dtor location to the object's location for error messages
+							auto dtorFunc = getDtorFunc( objDecl, dtorStmt, stmtsToAddBefore );
+							objDecl->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, dtorFunc ) } ) );
+							// ctorInit->dtor = nullptr;
+						} // if
+					}
+				} // if
+			} else if ( const ast::Init * init = ctorInit->init ) {
+				objDecl->init = init;
+				// ctorInit->init = nullptr;
+			} else {
+				// no constructor and no initializer, which is okay
+				objDecl->init = nullptr;
+			} // if
+			// delete ctorInit;
+			return objDecl;
+		} // if
+		return _objDecl;
+	}
+
+	void ObjDeclCollector::previsit( const ast::CompoundStmt * ) {
+		GuardValue( curVars );
+	}
+
+	void ObjDeclCollector::previsit( const ast::DeclStmt * stmt ) {
+		// keep track of all variables currently in scope
+		if ( auto objDecl = stmt->decl.as<ast::ObjectDecl>() ) {
+			curVars.push_back( objDecl );
+		} // if
+	}
+
+	void LabelFinder::previsit( const ast::Stmt * stmt ) {
+		// for each label, remember the variables in scope at that label.
+		for ( auto l : stmt->labels ) {
+			vars[l] = curVars;
+		} // for
+	}
+
+	void LabelFinder::previsit( const ast::CompoundStmt * stmt ) {
+		previsit( (const ast::Stmt *) stmt );
+		Parent::previsit( stmt );
+	}
+
+	void LabelFinder::previsit( const ast::DeclStmt * stmt ) {
+		previsit( (const ast::Stmt *)stmt );
+		Parent::previsit( stmt );
+	}
+
+
+	void InsertDtors::previsit( const ast::FunctionDecl * funcDecl ) {
+		// each function needs to have its own set of labels
+		GuardValue( labelVars );
+		labelVars.clear();
+		// LabelFinder does not recurse into FunctionDecl, so need to visit
+		// its children manually.
+		if (funcDecl->type) funcDecl->type->accept(finder);
+		// maybeAccept( funcDecl->type, finder );
+		if (funcDecl->stmts) funcDecl->stmts->accept(finder) ;
+
+		// all labels for this function have been collected, insert destructors as appropriate via implicit recursion.
+	}
+
+	// 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( const ast::BranchStmt * stmt ) {
+		// can't do anything for computed goto
+		if ( stmt->computedTarget ) return;
+
+		assertf( stmt->target.name != "", "BranchStmt missing a label: %s", toString( stmt ).c_str() );
+		// 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->target ];
+
+		DTOR_PRINT(
+			std::cerr << "at goto label: " << stmt->target.name << std::endl;
+			std::cerr << "S_G = " << printSet( curVars ) << std::endl;
+			std::cerr << "S_L = " << printSet( lvars ) << std::endl;
+		)
+
+
+		// std::set_difference requires that the inputs be sorted.
+		lvars.sort();
+		curVars.sort();
+
+		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() ) {
+			SemanticError( stmt, std::string("jump to label '") + stmt->target.name + "' crosses initialization of " + (*diff.begin())->name + " " );
+		} // if
+	}
+
+	void InsertDtors::previsit( const ast::BranchStmt * stmt ) {
+		switch( stmt->kind ) {
+		  case ast::BranchStmt::Continue:
+		  case ast::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 ast::BranchStmt::Goto:
+			handleGoto( stmt );
+			break;
+		  default:
+			assert( false );
+		} // switch
+	}
+
+	bool checkWarnings( const ast::FunctionDecl * funcDecl ) {
+		// only check for warnings if the current function is a user-defined
+		// constructor or destructor
+		if ( ! funcDecl ) return false;
+		if ( ! funcDecl->stmts ) return false;
+		return CodeGen::isCtorDtor( funcDecl->name ) && ! funcDecl->linkage.is_overrideable;
+	}
+
+	void GenStructMemberCalls::previsit( const ast::FunctionDecl * funcDecl ) {
+		GuardValue( function );
+		GuardValue( unhandled );
+		GuardValue( usedUninit );
+		GuardValue( thisParam );
+		GuardValue( isCtor );
+		GuardValue( structDecl );
+		errors = SemanticErrorException();  // clear previous errors
+
+		// need to start with fresh sets
+		unhandled.clear();
+		usedUninit.clear();
+
+		function = mutate(funcDecl);
+		// could this be non-unique?
+		if (function != funcDecl) {
+			std::cerr << "GenStructMemberCalls: non-unique FunctionDecl " << funcDecl->location << funcDecl->name << std::endl;
+		}
+
+		isCtor = CodeGen::isConstructor( function->name );
+		if ( checkWarnings( function ) ) {
+			// const ast::FunctionType * type = function->type;
+			// assert( ! type->params.empty() );
+			thisParam = function->params.front().strict_as<ast::ObjectDecl>();
+			auto thisType = getPointerBase( thisParam->get_type() );
+			auto structType = dynamic_cast< const ast::StructInstType * >( thisType );
+			if ( structType ) {
+				structDecl = structType->base;
+				for ( auto & member : structDecl->members ) {
+					if ( auto field = member.as<ast::ObjectDecl>() ) {
+						// record all of the struct type's members that need to be constructed or
+						// destructed by the end of the function
+						unhandled.insert( field );
 					}
 				}
-				isSimilar = false;
-			}
-
-			void previsit( const ast::VariableExpr * varExpr ) {
-				if ( auto otherVar = cast< const ast::VariableExpr >( other ) ) {
-					if ( otherVar->var == varExpr->var ) {
-						return;
+			}
+		}
+	}
+
+	const ast::DeclWithType * GenStructMemberCalls::postvisit( const ast::FunctionDecl * funcDecl ) {
+		// remove the unhandled objects from usedUninit, because a call is inserted
+		// to handle them - only objects that are later constructed are used uninitialized.
+		std::map< const ast::DeclWithType *, CodeLocation > diff;
+		// need the comparator since usedUninit and unhandled have different types
+		struct comp_t {
+			typedef decltype(usedUninit)::value_type usedUninit_t;
+			typedef decltype(unhandled)::value_type unhandled_t;
+			bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; }
+			bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; }
+		} comp;
+		std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp );
+		for ( auto p : diff ) {
+			auto member = p.first;
+			auto loc = p.second;
+			// xxx - make error message better by also tracking the location that the object is constructed at?
+			emit( loc, "in ", function->name, ", field ", member->name, " used before being constructed" );
+		}
+
+		const CodeLocation loc = funcDecl->location;
+
+		if ( ! unhandled.empty() ) {
+			auto mutStmts = function->stmts.get_and_mutate();
+			// need to explicitly re-add function parameters to the indexer in order to resolve copy constructors
+			auto guard = makeFuncGuard( [this]() { symtab.enterScope(); }, [this]() { symtab.leaveScope(); } );
+			symtab.addFunction( function );
+
+			// need to iterate through members in reverse in order for
+			// ctor/dtor statements to come out in the right order
+			for ( auto & member : reverseIterate( structDecl->members ) ) {
+				auto field = member.as<ast::ObjectDecl>();
+				// skip non-DWT members
+				if ( ! field ) continue;
+				// skip non-constructable members
+				if ( ! tryConstruct( field ) ) continue;
+				// skip handled members
+				if ( ! unhandled.count( field ) ) continue;
+
+				// insert and resolve default/copy constructor call for each field that's unhandled
+				// std::list< const ast::Stmt * > stmt;
+				ast::Expr * arg2 = nullptr;
+				if ( function->name == "?{}" && isCopyFunction( function ) ) {
+					// if copy ctor, need to pass second-param-of-this-function.field
+					// std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
+					assert( function->params.size() == 2 );
+					arg2 = new ast::MemberExpr(funcDecl->location, field, new ast::VariableExpr(funcDecl->location, function->params.back() ) );
+				}
+				InitExpander_new srcParam( arg2 );
+				// cast away reference type and construct field.
+				ast::Expr * thisExpr = new ast::CastExpr(funcDecl->location, new ast::VariableExpr(funcDecl->location, thisParam ), thisParam->get_type()->stripReferences());
+				ast::Expr * memberDest = new ast::MemberExpr(funcDecl->location, field, thisExpr );
+				ast::ptr<ast::Stmt> callStmt = SymTab::genImplicitCall( srcParam, memberDest, loc, function->name, field, static_cast<SymTab::LoopDirection>(isCtor) );
+
+				if ( callStmt ) {
+					// auto & callStmt = stmt.front();
+
+					try {
+						callStmt = callStmt->accept( *visitor );
+						if ( isCtor ) {
+							mutStmts->push_front( callStmt );
+						} else { // TODO: don't generate destructor function/object for intrinsic calls
+							// destructor statements should be added at the end
+							// function->get_statements()->push_back( callStmt );
+
+							// Optimization: do not need to call intrinsic destructors on members
+							if ( isIntrinsicSingleArgCallStmt( callStmt ) ) continue;
+
+							// __Destructor _dtor0 = { (void *)&b.a1, (void (*)(void *)_destroy_A };
+							std::list< ast::ptr<ast::Stmt> > stmtsToAdd;
+
+							static UniqueName memberDtorNamer = { "__memberDtor" };
+							assertf( Validate::dtorStruct, "builtin __Destructor not found." );
+							assertf( Validate::dtorStructDestroy, "builtin __destroy_Destructor not found." );
+
+							ast::Expr * thisExpr = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, thisParam ) ), new ast::PointerType( new ast::VoidType(), ast::CV::Qualifiers() ) );
+							ast::Expr * dtorExpr = new ast::VariableExpr(loc, getDtorFunc( thisParam, callStmt, stmtsToAdd ) );
+
+							// cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings
+							auto dtorFtype = new ast::FunctionType();
+							dtorFtype->params.emplace_back( new ast::PointerType( new ast::VoidType() ) );
+							auto dtorType = new ast::PointerType( dtorFtype );
+
+							auto destructor = new ast::ObjectDecl(loc, memberDtorNamer.newName(), new ast::StructInstType( ast::dtorStruct ), new ast::ListInit(loc, { new ast::SingleInit(loc, thisExpr ), new ast::SingleInit(loc, new ast::CastExpr( dtorExpr, dtorType ) ) } ) );
+							destructor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr({}, ast::dtorStructDestroy ) } ) );
+							mutStmts->push_front( new ast::DeclStmt(loc, destructor ) );
+							mutStmts->kids.splice( mutStmts->kids.begin(), stmtsToAdd );
+						}
+					} catch ( SemanticErrorException & error ) {
+						emit( funcDecl->location, "in ", function->name , ", field ", field->name, " not explicitly ", isCtor ? "constructed" : "destructed",  " and no ", isCtor ? "default constructor" : "destructor", " found" );
 					}
 				}
-				isSimilar = false;
-			}
-
-			void previsit( const ast::AddressExpr * ) {
-				if ( auto addrExpr = cast< const ast::AddressExpr >( other ) ) {
-					other = addrExpr->arg;
-					return;
+			}
+			function->stmts = mutStmts;
+		}
+		if (! errors.isEmpty()) {
+			throw errors;
+		}
+		// return funcDecl;
+		return function;
+	}
+
+	/// true if expr is effectively just the 'this' parameter
+	bool isThisExpression( const ast::Expr * expr, const ast::DeclWithType * thisParam ) {
+		// TODO: there are more complicated ways to pass 'this' to a constructor, e.g. &*, *&, etc.
+		if ( auto varExpr = dynamic_cast< const ast::VariableExpr * >( expr ) ) {
+			return varExpr->var == thisParam;
+		} else if ( auto castExpr = dynamic_cast< const ast::CastExpr * > ( expr ) ) {
+			return isThisExpression( castExpr->arg, thisParam );
+		}
+		return false;
+	}
+
+	/// returns a MemberExpr if expr is effectively just member access on the 'this' parameter, else nullptr
+	const ast::MemberExpr * isThisMemberExpr( const ast::Expr * expr, const ast::DeclWithType * thisParam ) {
+		if ( auto memberExpr = dynamic_cast< const ast::MemberExpr * >( expr ) ) {
+			if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
+				return memberExpr;
+			}
+		} else if ( auto castExpr = dynamic_cast< const ast::CastExpr * >( expr ) ) {
+			return isThisMemberExpr( castExpr->arg, thisParam );
+		}
+		return nullptr;
+	}
+
+	void GenStructMemberCalls::previsit( const ast::ApplicationExpr * appExpr ) {
+		if ( ! checkWarnings( function ) ) {
+			visit_children = false;
+			return;
+		}
+
+		std::string fname = getFunctionName( appExpr );
+		if ( fname == function->name ) {
+			// call to same kind of function
+			const ast::Expr * firstParam = appExpr->args.front();
+
+			if ( isThisExpression( firstParam, thisParam ) ) {
+				// if calling another constructor on thisParam, assume that function handles
+				// all members - if it doesn't a warning will appear in that function.
+				unhandled.clear();
+			} else if ( auto memberExpr = isThisMemberExpr( firstParam, thisParam ) ) {
+				// if first parameter is a member expression on the this parameter,
+				// then remove the member from unhandled set.
+				if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
+					unhandled.erase( memberExpr->member );
 				}
-				isSimilar = false;
-			}
-
-			const ast::Expr * other = nullptr;
-			bool isSimilar = true;
-		};
-
-		bool structurallySimilar( const ast::Expr * e1, const ast::Expr * e2 ) {
-			ast::Pass<StructuralChecker> checker;
-			checker.core.other = e2;
-			e1->accept( checker );
-			return checker.core.isSimilar;
-		}
-
-		void SelfAssignChecker::previsit( const ast::ApplicationExpr * appExpr ) {
-			auto function = getFunction( appExpr );
-			if ( function->name == "?=?" ) { // doesn't use isAssignment, because ?+=?, etc. should not count as self-assignment
-				if ( appExpr->args.size() == 2 ) {
-					// check for structural similarity (same variable use, ignore casts, etc. - but does not look too deeply, anything looking like a function is off limits)
-					if ( structurallySimilar( appExpr->args.front(), appExpr->args.back() ) ) {
-						SemanticWarning( appExpr->location, Warning::SelfAssignment, toCString( appExpr->args.front() ) );
-					}
-				}
-			}
-		}
-
-		const ast::Expr * InsertImplicitCalls::postvisit( const ast::ApplicationExpr * appExpr ) {
-			if ( auto function = appExpr->func.as<ast::VariableExpr>() ) {
-				if ( function->var->linkage.is_builtin ) {
-					// optimization: don't need to copy construct in order to call intrinsic functions
-					return appExpr;
-				} else if ( auto funcDecl = function->var.as<ast::DeclWithType>() ) {
-					auto ftype = dynamic_cast< const ast::FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
-					assertf( ftype, "Function call without function type: %s", toString( funcDecl ).c_str() );
-					if ( CodeGen::isConstructor( funcDecl->name ) && ftype->params.size() == 2 ) {
-						auto t1 = getPointerBase( ftype->params.front() );
-						auto t2 = ftype->params.back();
-						assert( t1 );
-
-						if ( ResolvExpr::typesCompatible( t1, t2 ) ) {
-							// optimization: don't need to copy construct in order to call a copy constructor
-							return appExpr;
-						} // if
-					} else if ( CodeGen::isDestructor( funcDecl->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
-			ast::ptr<ast::TypeSubstitution> tmp = appExpr->env;
-			auto mutExpr = mutate(appExpr);
-			mutExpr->env = nullptr;
-
-			auto expr = new ast::ImplicitCopyCtorExpr( appExpr->location, mutExpr );
-			// Move the type substitution to the new top-level, if it is attached to the appExpr.
-			// 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.
-			assert( typeSubs );
-			// assert (mutExpr->env);
-			expr->env = tmp;
-			// mutExpr->env = nullptr;
-			//std::swap( expr->env, appExpr->env );
-			return expr;
-		}
-
-		void ResolveCopyCtors::previsit(const ast::Expr * expr) {
-			if (expr->env) {
-				GuardValue(env);
-				GuardValue(envModified);
-				env = expr->env->clone();
-				envModified = false;
-			}
-		}
-
-		const ast::Expr * ResolveCopyCtors::postvisit(const ast::Expr * expr) {
-			if (expr->env) {
-				if (envModified) {
-					auto mutExpr = mutate(expr);
-					mutExpr->env = env;
-					return mutExpr;
-				}
-				else {
-					// env was not mutated, skip and delete the shallow copy
-					delete env;
-					return expr;
-				}
-			}
-			else {
-				return expr;
-			}
-		}
-
-		bool ResolveCopyCtors::skipCopyConstruct( const ast::Type * type ) { return ! isConstructable( type ); }
-
-		const ast::Expr * ResolveCopyCtors::makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg ) {
-			assert( var );
-			assert (var->isManaged());
-			assert (!cpArg || cpArg->isManaged());
-			// arrays are not copy constructed, so this should always be an ExprStmt
-			ast::ptr< ast::Stmt > stmt = genCtorDtor(var->location, fname, var, cpArg );
-			assertf( stmt, "ResolveCopyCtors: genCtorDtor returned nullptr: %s / %s / %s", fname.c_str(), toString( var ).c_str(), toString( cpArg ).c_str() );
-			auto exprStmt = stmt.strict_as<ast::ImplicitCtorDtorStmt>()->callStmt.strict_as<ast::ExprStmt>();
-			ast::ptr<ast::Expr> untyped = exprStmt->expr; // take ownership of expr
-			// exprStmt->expr = nullptr; 
-
-			// 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; )
-			ast::ptr<ast::Expr> resolved = ResolvExpr::findVoidExpression(untyped, symtab);
-			assert( resolved );
-			if ( resolved->env ) {
-				// Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
-				env->add( *resolved->env );
-				envModified = true;
-				// delete resolved->env;
-				auto mut = mutate(resolved.get());
-				assertf(mut == resolved.get(), "newly resolved expression must be unique");
-				mut->env = nullptr;
-			} // if
-			// delete stmt;
-			if ( auto assign = resolved.as<ast::TupleAssignExpr>() ) {
-				// fix newly generated StmtExpr
-				previsit( assign->stmtExpr );
-			}
-			return resolved.release();
-		}
-
-		ast::ptr<ast::Expr> ResolveCopyCtors::copyConstructArg( 
-			const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal )
-		{
-			static UniqueName tempNamer("_tmp_cp");
-			assert( env );
-			const CodeLocation loc = impCpCtorExpr->location;
-			// CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
-			assert( arg->result );
-			ast::ptr<ast::Type> result = arg->result;
-			if ( skipCopyConstruct( result ) ) return arg; // skip certain non-copyable types
-
-			// type may involve type variables, so apply type substitution to get temporary variable's actual type,
-			// since result type may not be substituted (e.g., if the type does not appear in the parameter list)
-			// Use applyFree so that types bound in function pointers are not substituted, e.g. in forall(dtype T) void (*)(T).
-			
-			// xxx - this originally mutates arg->result in place. is it correct?
-			result = env->applyFree( result.get() ).node;
-			auto mutResult = result.get_and_mutate();
-			mutResult->set_const(false);
-
-			auto mutArg = mutate(arg);
-			mutArg->result = mutResult;
-
-			ast::ptr<ast::Expr> guard = mutArg;
-
-			ast::ptr<ast::ObjectDecl> tmp = new ast::ObjectDecl({}, "__tmp", mutResult, nullptr );
-
-			// create and resolve copy constructor
-			CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
-			auto cpCtor = makeCtorDtor( "?{}", tmp, mutArg );
-
-			if ( auto appExpr = dynamic_cast< const ast::ApplicationExpr * >( cpCtor ) ) {
-				// if the chosen constructor is intrinsic, the copy is unnecessary, so
-				// don't create the temporary and don't call the copy constructor
-				auto function = appExpr->func.strict_as<ast::VariableExpr>();
-				if ( function->var->linkage == ast::Linkage::Intrinsic ) {
-					// arguments that need to be boxed need a temporary regardless of whether the copy constructor is intrinsic,
-					// so that the object isn't changed inside of the polymorphic function
-					if ( ! GenPoly::needsBoxing( formal, result, impCpCtorExpr->callExpr, env ) ) {
-						// xxx - should arg->result be mutated? see comment above.
-						return guard;
-					}
-				}
-			}
-
-			// set a unique name for the temporary once it's certain the call is necessary
-			auto mut = tmp.get_and_mutate();
-			assertf (mut == tmp, "newly created ObjectDecl must be unique");
-			mut->name = tempNamer.newName();
-
-			// replace argument to function call with temporary
-			stmtsToAddBefore.push_back( new ast::DeclStmt(loc, tmp ) );
-			arg = cpCtor;
-			return destructRet( tmp, arg );
-
-			// impCpCtorExpr->dtors.push_front( makeCtorDtor( "^?{}", tmp ) );
-		}
-
-		ast::Expr * ResolveCopyCtors::destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ) {
-			// TODO: refactor code for generating cleanup attribute, since it's common and reused in ~3-4 places
-			// check for existing cleanup attribute before adding another(?)
-			// need to add __Destructor for _tmp_cp variables as well
-
-			assertf( ast::dtorStruct && ast::dtorStruct->members.size() == 2, "Destructor generation requires __Destructor definition." );
-			assertf( ast::dtorStructDestroy, "Destructor generation requires __destroy_Destructor." );
-
-			const CodeLocation loc = ret->location;
-
-			// generate a __Destructor for ret that calls the destructor
-			auto res = makeCtorDtor( "^?{}", ret );
-			auto dtor = mutate(res);
-
-			// if the chosen destructor is intrinsic, elide the generated dtor handler
-			if ( arg && isIntrinsicCallExpr( dtor ) ) {
-				return new ast::CommaExpr(loc, arg, new ast::VariableExpr(loc, ret ) );
-				// return;
-			}
-
-			if ( ! dtor->env ) dtor->env = maybeClone( env );
-			auto dtorFunc = getDtorFunc( ret, new ast::ExprStmt(loc, dtor ), stmtsToAddBefore );
-
-			auto dtorStructType = new ast::StructInstType(ast::dtorStruct);
-
-			// what does this do???
-			dtorStructType->params.push_back( new ast::TypeExpr(loc, new ast::VoidType() ) );
-
-			// cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings
-			auto dtorFtype = new ast::FunctionType();
-			dtorFtype->params.push_back( new ast::PointerType(new ast::VoidType( ) ) );
-			auto dtorType = new ast::PointerType( dtorFtype );
-
-			static UniqueName namer( "_ret_dtor" );
-			auto retDtor = new ast::ObjectDecl(loc, namer.newName(), dtorStructType, new ast::ListInit(loc, { new ast::SingleInit(loc, ast::ConstantExpr::null(loc) ), new ast::SingleInit(loc, new ast::CastExpr( new ast::VariableExpr(loc, dtorFunc ), dtorType ) ) } ) );
-			retDtor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, ast::dtorStructDestroy ) } ) );
-			stmtsToAddBefore.push_back( new ast::DeclStmt(loc, retDtor ) );
-
-			if ( arg ) {
-				auto member = new ast::MemberExpr(loc, ast::dtorStruct->members.front().strict_as<ast::DeclWithType>(), new ast::VariableExpr(loc, retDtor ) );
-				auto object = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, ret ) ), new ast::PointerType(new ast::VoidType() ) );
-				ast::Expr * assign = createBitwiseAssignment( member, object );
-				return new ast::CommaExpr(loc, new ast::CommaExpr(loc, arg, assign ), new ast::VariableExpr(loc, ret ) );
-			}
-			return nullptr;
-			// impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
-		}
-
-		const ast::Expr * ResolveCopyCtors::postvisit( const ast::ImplicitCopyCtorExpr *impCpCtorExpr ) {
-			CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
-
-			ast::ApplicationExpr * appExpr = mutate(impCpCtorExpr->callExpr.get());
-			const ast::ObjectDecl * returnDecl = nullptr;
-			const CodeLocation loc = appExpr->location;
-
-			// take each argument and attempt to copy construct it.
-			auto ftype = GenPoly::getFunctionType( appExpr->func->result );
-			assert( ftype );
-			auto & params = ftype->params;
-			auto iter = params.begin();
-			for ( auto & arg : appExpr->args ) {
-				const ast::Type * formal = nullptr;
-				if ( iter != params.end() ) { // does not copy construct C-style variadic arguments
-					// DeclarationWithType * param = *iter++;
-					formal = *iter++;
-				}
-
-				arg = copyConstructArg( arg, impCpCtorExpr, formal );
-			} // 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 named return values?
-			const ast::Type * result = appExpr->result;
-			if ( ! result->isVoid() ) {
-				static UniqueName retNamer("_tmp_cp_ret");
-				// result = result->clone();
-				auto subResult = env->apply( result ).node;
-				auto ret = new ast::ObjectDecl(loc, retNamer.newName(), subResult, nullptr );
-				auto mutType = mutate(ret->type.get());
-				mutType->set_const( false );
-				ret->type = mutType;
-				returnDecl = ret;
-				stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) );
-				CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
-			} // for
-			CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
-			// ------------------------------------------------------
-
-			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
-
-			// xxx - actual env might be somewhere else, need to keep invariant
-
-			// deletion of wrapper should be handled by pass template now
-			
-			// impCpCtorExpr->callExpr = nullptr;
-			assert (appExpr->env == nullptr);
-			appExpr->env = impCpCtorExpr->env;
-			// std::swap( impCpCtorExpr->env, appExpr->env );
-			// assert( impCpCtorExpr->env == nullptr );
-			// delete impCpCtorExpr;
-
-			if ( returnDecl ) {
-				ast::Expr * assign = createBitwiseAssignment( new ast::VariableExpr(loc, returnDecl ), appExpr );
-				if ( ! dynamic_cast< const ast::ReferenceType * >( result ) ) {
-					// destructing reference returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
-					assign = destructRet( returnDecl, assign );
-					assert(assign);
-				} else {
-					assign = new ast::CommaExpr(loc, assign, new ast::VariableExpr(loc, returnDecl ) );
-				}
-				// move env from appExpr to retExpr
-				// std::swap( assign->env, appExpr->env );
-				assign->env = appExpr->env;
-				// actual env is handled by common routine that replaces WithTypeSubstitution
-				return postvisit((const ast::Expr *)assign);
-			} else {
-				return postvisit((const ast::Expr *)appExpr);
-			} // if
-		}
-
-		const ast::StmtExpr * ResolveCopyCtors::previsit( const ast::StmtExpr * _stmtExpr ) {
-			// function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression,
-			// since temporaries can be shared across sub-expressions, e.g.
-			//   [A, A] f();       // decl
-			//   g([A] x, [A] y);  // decl
-			//   g(f());           // call
-			// f is executed once, so the return temporary is shared across the tuple constructors for x and y.
-			// Explicitly mutating children instead of mutating the inner compound statement forces the temporaries to be added
-			// to the outer context, rather than inside of the statement expression.
-
-			// call the common routine that replaces WithTypeSubstitution
-			previsit((const ast::Expr *) _stmtExpr);
-
+			}
+		}
+	}
+
+	void GenStructMemberCalls::previsit( const ast::MemberExpr * memberExpr ) {
+		if ( ! checkWarnings( function ) || ! isCtor ) {
 			visit_children = false;
-			const CodeLocation loc = _stmtExpr->location;
-
-			assert( env );
-
-			symtab.enterScope();
-			// visit all statements
-			auto stmtExpr = mutate(_stmtExpr);
-			auto mutStmts = mutate(stmtExpr->stmts.get());
-
-			auto & stmts = mutStmts->kids;
-			for ( auto & stmt : stmts ) {
-				stmt = stmt->accept( *visitor );
-			} // for
-			stmtExpr->stmts = mutStmts;
-			symtab.leaveScope();
-
-			assert( stmtExpr->result );
-			// const ast::Type * result = stmtExpr->result;
-			if ( ! stmtExpr->result->isVoid() ) {
-				static UniqueName retNamer("_tmp_stmtexpr_ret");
-
-				// result = result->clone();
-				auto result = env->apply( stmtExpr->result.get() ).node;
-				if ( ! InitTweak::isConstructable( result ) ) {
-					// delete result;
-					return stmtExpr;
-				}
-				auto mutResult = result.get_and_mutate();
-				mutResult->set_const(false);
-
-				// create variable that will hold the result of the stmt expr
-				auto ret = new ast::ObjectDecl(loc, retNamer.newName(), mutResult, nullptr );
-				stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) );
-
-				assertf(
-					stmtExpr->resultExpr,
-					"Statement-Expression should have a resulting expression at %s:%d",
-					stmtExpr->location.filename.c_str(),
-					stmtExpr->location.first_line
-				);
-
-				const ast::ExprStmt * last = stmtExpr->resultExpr;
-				// xxx - if this is non-unique, need to copy while making resultExpr ref
-				assertf(last->unique(), "attempt to modify weakly shared statement");
-				auto mutLast = mutate(last);
-				// above assertion means in-place mutation is OK
-				try {
-					mutLast->expr = makeCtorDtor( "?{}", ret, mutLast->expr );
-				} catch(...) {
-					std::cerr << "*CFA internal error: ";
-					std::cerr << "can't resolve implicit constructor";
-					std::cerr << " at " << stmtExpr->location.filename;
-					std::cerr << ":" << stmtExpr->location.first_line << std::endl;
-
-					abort();
-				}
-
-				// add destructors after current statement
-				stmtsToAddAfter.push_back( new ast::ExprStmt(loc, makeCtorDtor( "^?{}", ret ) ) );
-
-				// must have a non-empty body, otherwise it wouldn't have a result
-				assert( ! stmts.empty() );
-
-				// if there is a return decl, add a use as the last statement; will not have return decl on non-constructable returns
-				stmts.push_back( new ast::ExprStmt(loc, new ast::VariableExpr(loc, ret ) ) );
-			} // if
-
-			assert( stmtExpr->returnDecls.empty() );
-			assert( stmtExpr->dtors.empty() );
-
-			return stmtExpr;
-		}
-
-		// to prevent warnings ('_unq0' may be used uninitialized in this function),
-		// insert an appropriate zero initializer for UniqueExpr temporaries.
-		ast::Init * makeInit( const ast::Type * t ) {
-			if ( auto inst = dynamic_cast< const ast::StructInstType * >( t ) ) {
-				// initizer for empty struct must be empty
-				if ( inst->base->members.empty() ) return new ast::ListInit({}, {});
-			} else if ( auto inst = dynamic_cast< const ast::UnionInstType * >( t ) ) {
-				// initizer for empty union must be empty
-				if ( inst->base->members.empty() ) return new ast::ListInit({}, {});
-			}
-
-			return new ast::ListInit( {}, { new ast::SingleInit( {}, ast::ConstantExpr::from_int({}, 0) ) } );
-		}
-
-		const ast::UniqueExpr * ResolveCopyCtors::previsit( const ast::UniqueExpr * unqExpr ) {
-			visit_children = false;
-			// xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
-			static std::unordered_map< int, const ast::UniqueExpr * > unqMap;
-			auto mutExpr = mutate(unqExpr);
-			if ( ! unqMap.count( unqExpr->id ) ) {
-				// resolve expr and find its
-
-				auto impCpCtorExpr = mutExpr->expr.as<ast::ImplicitCopyCtorExpr>();
-				// PassVisitor<ResolveCopyCtors> fixer;
-				
-				mutExpr->expr = mutExpr->expr->accept( *visitor );
-				// it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
-				assert( unqExpr->result );
-				if ( impCpCtorExpr ) {
-					auto comma = unqExpr->expr.strict_as<ast::CommaExpr>();
-					auto var = comma->arg2.strict_as<ast::VariableExpr>();
-					// note the variable used as the result from the call
-					mutExpr->var = var;
-				} else {
-					// expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
-					mutExpr->object = new ast::ObjectDecl( mutExpr->location, toString("_unq", mutExpr->id), mutExpr->result, makeInit( mutExpr->result ) );
-					mutExpr->var = new ast::VariableExpr( mutExpr->location, mutExpr->object );
-				}
-
-				// stmtsToAddBefore.splice( stmtsToAddBefore.end(), fixer.pass.stmtsToAddBefore );
-				// stmtsToAddAfter.splice( stmtsToAddAfter.end(), fixer.pass.stmtsToAddAfter );
-				unqMap[mutExpr->id] = mutExpr;
-			} else {
-				// take data from other UniqueExpr to ensure consistency
-				// delete unqExpr->get_expr();
-				mutExpr->expr = unqMap[mutExpr->id]->expr;
-				// delete unqExpr->result;
-				mutExpr->result = mutExpr->expr->result;
-			}
-			return mutExpr;
-		}
-
-		const ast::DeclWithType * FixInit::postvisit( const ast::ObjectDecl *_objDecl ) {
-			const CodeLocation loc = _objDecl->location;
-
-			// since this removes the init field from objDecl, it must occur after children are mutated (i.e. postvisit)
-			if ( ast::ptr<ast::ConstructorInit> ctorInit = _objDecl->init.as<ast::ConstructorInit>() ) {
-				auto objDecl = mutate(_objDecl);
-
-				// could this be non-unique?
-				if (objDecl != _objDecl) {
-					std::cerr << "FixInit: non-unique object decl " << objDecl->location << objDecl->name << std::endl;
-				}
-				// a decision should have been made by the resolver, so ctor and init are not both non-NULL
-				assert( ! ctorInit->ctor || ! ctorInit->init );
-				if ( const ast::Stmt * ctor = ctorInit->ctor ) {
-					if ( objDecl->storage.is_static ) {
-						// originally wanted to take advantage of gcc nested functions, but
-						// we get memory errors with this approach. To remedy this, the static
-						// variable is hoisted when the destructor needs to be called.
-						//
-						// generate:
-						// static T __objName_static_varN;
-						// void __objName_dtor_atexitN() {
-						//   __dtor__...;
-						// }
-						// int f(...) {
-						//   ...
-						//   static bool __objName_uninitialized = true;
-						//   if (__objName_uninitialized) {
-						//     __ctor(__objName);
-						//     __objName_uninitialized = false;
-						//     atexit(__objName_dtor_atexitN);
-						//   }
-						//   ...
-						// }
-
-						static UniqueName dtorCallerNamer( "_dtor_atexit" );
-
-						// static bool __objName_uninitialized = true
-						auto boolType = new ast::BasicType( ast::BasicType::Kind::Bool );
-						auto boolInitExpr = new ast::SingleInit(loc, ast::ConstantExpr::from_int(loc, 1 ) );
-						auto isUninitializedVar = new ast::ObjectDecl(loc, objDecl->mangleName + "_uninitialized", boolType, boolInitExpr, ast::Storage::Static, ast::Linkage::Cforall);
-						isUninitializedVar->fixUniqueId();
-
-						// __objName_uninitialized = false;
-						auto setTrue = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ) );
-						setTrue->args.push_back( new ast::VariableExpr(loc, isUninitializedVar ) );
-						setTrue->args.push_back( ast::ConstantExpr::from_int(loc, 0 ) );
-
-						// generate body of if
-						auto initStmts = new ast::CompoundStmt(loc);
-						auto & body = initStmts->kids;
-						body.push_back( ctor );
-						body.push_back( new ast::ExprStmt(loc, setTrue ) );
-
-						// put it all together
-						auto ifStmt = new ast::IfStmt(loc, new ast::VariableExpr(loc, isUninitializedVar ), initStmts, 0 );
-						stmtsToAddAfter.push_back( new ast::DeclStmt(loc, isUninitializedVar ) );
-						stmtsToAddAfter.push_back( ifStmt );
-
-						const ast::Stmt * dtor = ctorInit->dtor;
-
-						// these should be automatically managed once reassigned
-						// objDecl->set_init( nullptr );
-						// ctorInit->set_ctor( nullptr );
-						// ctorInit->set_dtor( nullptr );
-						if ( dtor ) {
-							// if the object has a non-trivial destructor, have to
-							// hoist it and the object into the global space and
-							// call the destructor function with atexit.
-
-							// Statement * dtorStmt = dtor->clone();
-
-							// void __objName_dtor_atexitN(...) {...}
-							ast::FunctionDecl * dtorCaller = new ast::FunctionDecl(loc, objDecl->mangleName + dtorCallerNamer.newName(), {}, {}, {}, new ast::CompoundStmt(loc, {dtor}), ast::Storage::Static, ast::Linkage::C );
-							dtorCaller->fixUniqueId();
-							// dtorCaller->stmts->push_back( dtor );
-
-							// atexit(dtor_atexit);
-							auto callAtexit = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "atexit" ) );
-							callAtexit->args.push_back( new ast::VariableExpr(loc, dtorCaller ) );
-
-							body.push_back( new ast::ExprStmt(loc, callAtexit ) );
-
-							// hoist variable and dtor caller decls to list of decls that will be added into global scope
-							staticDtorDecls.push_back( objDecl );
-							staticDtorDecls.push_back( dtorCaller );
-
-							// need to rename object uniquely since it now appears
-							// at global scope and there could be multiple function-scoped
-							// static variables with the same name in different functions.
-							// Note: it isn't sufficient to modify only the mangleName, because
-							// then subsequent Indexer passes can choke on seeing the object's name
-							// if another object has the same name and type. An unfortunate side-effect
-							// of renaming the object is that subsequent NameExprs may fail to resolve,
-							// but there shouldn't be any remaining past this point.
-							static UniqueName staticNamer( "_static_var" );
-							objDecl->name = objDecl->name + staticNamer.newName();
-							objDecl->mangleName = Mangle::mangle( objDecl );
-
-							// xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
-							// create a new object which is never used
-							static UniqueName dummyNamer( "_dummy" );
-							auto dummy = new ast::ObjectDecl(loc, dummyNamer.newName(), new ast::PointerType(new ast::VoidType()), nullptr, ast::Storage::Static, ast::Linkage::Cforall, 0, { new ast::Attribute("unused") } );
-							// delete ctorInit;
-							return dummy;
-						} else {
-							objDecl->init = nullptr;
-							return objDecl;
-						}
-					} else {
-						auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * > ( ctor );
-						auto ctorStmt = implicit->callStmt.as<ast::ExprStmt>();
-						const ast::ApplicationExpr * ctorCall = nullptr;
-						if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->expr )) && ctorCall->args.size() == 2 ) {
-							// clean up intrinsic copy constructor calls by making them into SingleInits
-							const ast::Expr * ctorArg = ctorCall->args.back();
-							// ctorCall should be gone afterwards
-							auto mutArg = mutate(ctorArg);
-							mutArg->env = ctorCall->env;
-							// std::swap( ctorArg->env, ctorCall->env );
-							objDecl->init = new ast::SingleInit(loc, mutArg );
-
-							// ctorCall->args.pop_back();
-						} else {
-							stmtsToAddAfter.push_back( ctor );
-							objDecl->init = nullptr;
-							// ctorInit->ctor = nullptr;
-						}
-
-						const ast::Stmt * dtor = ctorInit->dtor;
-						if ( dtor ) {
-							auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * >( dtor );
-							const ast::Stmt * dtorStmt = implicit->callStmt;
-
-							// don't need to call intrinsic dtor, because it does nothing, but
-							// non-intrinsic dtors must be called
-							if ( ! isIntrinsicSingleArgCallStmt( dtorStmt ) ) {
-								// set dtor location to the object's location for error messages
-								auto dtorFunc = getDtorFunc( objDecl, dtorStmt, stmtsToAddBefore );
-								objDecl->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, dtorFunc ) } ) );
-								// ctorInit->dtor = nullptr;
-							} // if
-						}
-					} // if
-				} else if ( const ast::Init * init = ctorInit->init ) {
-					objDecl->init = init;
-					// ctorInit->init = nullptr;
-				} else {
-					// no constructor and no initializer, which is okay
-					objDecl->init = nullptr;
-				} // if
-				// delete ctorInit;
-				return objDecl;
-			} // if
-			return _objDecl;
-		}
-
-		void ObjDeclCollector::previsit( const ast::CompoundStmt * ) {
-			GuardValue( curVars );
-		}
-
-		void ObjDeclCollector::previsit( const ast::DeclStmt * stmt ) {
-			// keep track of all variables currently in scope
-			if ( auto objDecl = stmt->decl.as<ast::ObjectDecl>() ) {
-				curVars.push_back( objDecl );
-			} // if
-		}
-
-		void LabelFinder::previsit( const ast::Stmt * stmt ) {
-			// for each label, remember the variables in scope at that label.
-			for ( auto l : stmt->labels ) {
-				vars[l] = curVars;
-			} // for
-		}
-
-		void LabelFinder::previsit( const ast::CompoundStmt * stmt ) {
-			previsit( (const ast::Stmt *) stmt );
-			Parent::previsit( stmt );
-		}
-
-		void LabelFinder::previsit( const ast::DeclStmt * stmt ) {
-			previsit( (const ast::Stmt *)stmt );
-			Parent::previsit( stmt );
-		}
-
-
-		void InsertDtors::previsit( const ast::FunctionDecl * funcDecl ) {
-			// each function needs to have its own set of labels
-			GuardValue( labelVars );
-			labelVars.clear();
-			// LabelFinder does not recurse into FunctionDecl, so need to visit
-			// its children manually.
-			if (funcDecl->type) funcDecl->type->accept(finder);
-			// maybeAccept( funcDecl->type, finder );
-			if (funcDecl->stmts) funcDecl->stmts->accept(finder) ;
-
-			// all labels for this function have been collected, insert destructors as appropriate via implicit recursion.
-		}
-
-		// 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( const ast::BranchStmt * stmt ) {
-			// can't do anything for computed goto
-			if ( stmt->computedTarget ) return;
-
-			assertf( stmt->target.name != "", "BranchStmt missing a label: %s", toString( stmt ).c_str() );
-			// 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->target ];
-
-			DTOR_PRINT(
-				std::cerr << "at goto label: " << stmt->target.name << std::endl;
-				std::cerr << "S_G = " << printSet( curVars ) << std::endl;
-				std::cerr << "S_L = " << printSet( lvars ) << std::endl;
-			)
-
-
-			// std::set_difference requires that the inputs be sorted.
-			lvars.sort();
-			curVars.sort();
-
-			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() ) {
-				SemanticError( stmt, std::string("jump to label '") + stmt->target.name + "' crosses initialization of " + (*diff.begin())->name + " " );
-			} // if
-		}
-
-		void InsertDtors::previsit( const ast::BranchStmt * stmt ) {
-			switch( stmt->kind ) {
-			  case ast::BranchStmt::Continue:
-			  case ast::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 ast::BranchStmt::Goto:
-				handleGoto( stmt );
-				break;
-			  default:
-				assert( false );
-			} // switch
-		}
-
-		bool checkWarnings( const ast::FunctionDecl * funcDecl ) {
-			// only check for warnings if the current function is a user-defined
-			// constructor or destructor
-			if ( ! funcDecl ) return false;
-			if ( ! funcDecl->stmts ) return false;
-			return CodeGen::isCtorDtor( funcDecl->name ) && ! funcDecl->linkage.is_overrideable;
-		}
-
-		void GenStructMemberCalls::previsit( const ast::FunctionDecl * funcDecl ) {
-			GuardValue( function );
-			GuardValue( unhandled );
-			GuardValue( usedUninit );
-			GuardValue( thisParam );
-			GuardValue( isCtor );
-			GuardValue( structDecl );
-			errors = SemanticErrorException();  // clear previous errors
-
-			// need to start with fresh sets
-			unhandled.clear();
-			usedUninit.clear();
-
-			function = mutate(funcDecl);
-			// could this be non-unique?
-			if (function != funcDecl) {
-				std::cerr << "GenStructMemberCalls: non-unique FunctionDecl " << funcDecl->location << funcDecl->name << std::endl;
-			}
-
-			isCtor = CodeGen::isConstructor( function->name );
-			if ( checkWarnings( function ) ) {
-				// const ast::FunctionType * type = function->type;
-				// assert( ! type->params.empty() );
-				thisParam = function->params.front().strict_as<ast::ObjectDecl>();
-				auto thisType = getPointerBase( thisParam->get_type() );
-				auto structType = dynamic_cast< const ast::StructInstType * >( thisType );
-				if ( structType ) {
-					structDecl = structType->base;
-					for ( auto & member : structDecl->members ) {
-						if ( auto field = member.as<ast::ObjectDecl>() ) {
-							// record all of the struct type's members that need to be constructed or
-							// destructed by the end of the function
-							unhandled.insert( field );
-						}
-					}
-				}
-			}
-		}
-
-		const ast::DeclWithType * GenStructMemberCalls::postvisit( const ast::FunctionDecl * funcDecl ) {
-			// remove the unhandled objects from usedUninit, because a call is inserted
-			// to handle them - only objects that are later constructed are used uninitialized.
-			std::map< const ast::DeclWithType *, CodeLocation > diff;
-			// need the comparator since usedUninit and unhandled have different types
-			struct comp_t {
-				typedef decltype(usedUninit)::value_type usedUninit_t;
-				typedef decltype(unhandled)::value_type unhandled_t;
-				bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; }
-				bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; }
-			} comp;
-			std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp );
-			for ( auto p : diff ) {
-				auto member = p.first;
-				auto loc = p.second;
-				// xxx - make error message better by also tracking the location that the object is constructed at?
-				emit( loc, "in ", function->name, ", field ", member->name, " used before being constructed" );
-			}
-
-			const CodeLocation loc = funcDecl->location;
-
-			if ( ! unhandled.empty() ) {
-				auto mutStmts = function->stmts.get_and_mutate();
-				// need to explicitly re-add function parameters to the indexer in order to resolve copy constructors
-				auto guard = makeFuncGuard( [this]() { symtab.enterScope(); }, [this]() { symtab.leaveScope(); } );
-				symtab.addFunction( function );
-
-				// need to iterate through members in reverse in order for
-				// ctor/dtor statements to come out in the right order
-				for ( auto & member : reverseIterate( structDecl->members ) ) {
-					auto field = member.as<ast::ObjectDecl>();
-					// skip non-DWT members
-					if ( ! field ) continue;
-					// skip non-constructable members
-					if ( ! tryConstruct( field ) ) continue;
-					// skip handled members
-					if ( ! unhandled.count( field ) ) continue;
-
-					// insert and resolve default/copy constructor call for each field that's unhandled
-					// std::list< const ast::Stmt * > stmt;
-					ast::Expr * arg2 = nullptr;
-					if ( function->name == "?{}" && isCopyFunction( function ) ) {
-						// if copy ctor, need to pass second-param-of-this-function.field
-						// std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
-						assert( function->params.size() == 2 );
-						arg2 = new ast::MemberExpr(funcDecl->location, field, new ast::VariableExpr(funcDecl->location, function->params.back() ) );
-					}
-					InitExpander_new srcParam( arg2 );
-					// cast away reference type and construct field.
-					ast::Expr * thisExpr = new ast::CastExpr(funcDecl->location, new ast::VariableExpr(funcDecl->location, thisParam ), thisParam->get_type()->stripReferences());
-					ast::Expr * memberDest = new ast::MemberExpr(funcDecl->location, field, thisExpr );
-					ast::ptr<ast::Stmt> callStmt = SymTab::genImplicitCall( srcParam, memberDest, loc, function->name, field, static_cast<SymTab::LoopDirection>(isCtor) );
-
-					if ( callStmt ) {
-						// auto & callStmt = stmt.front();
-
-						try {
-							callStmt = callStmt->accept( *visitor );
-							if ( isCtor ) {
-								mutStmts->push_front( callStmt );
-							} else { // TODO: don't generate destructor function/object for intrinsic calls
-								// destructor statements should be added at the end
-								// function->get_statements()->push_back( callStmt );
-
-								// Optimization: do not need to call intrinsic destructors on members
-								if ( isIntrinsicSingleArgCallStmt( callStmt ) ) continue;
-
-								// __Destructor _dtor0 = { (void *)&b.a1, (void (*)(void *)_destroy_A };
-								std::list< ast::ptr<ast::Stmt> > stmtsToAdd;
-
-								static UniqueName memberDtorNamer = { "__memberDtor" };
-								assertf( Validate::dtorStruct, "builtin __Destructor not found." );
-								assertf( Validate::dtorStructDestroy, "builtin __destroy_Destructor not found." );
-
-								ast::Expr * thisExpr = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, thisParam ) ), new ast::PointerType( new ast::VoidType(), ast::CV::Qualifiers() ) );
-								ast::Expr * dtorExpr = new ast::VariableExpr(loc, getDtorFunc( thisParam, callStmt, stmtsToAdd ) );
-
-								// cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings
-								auto dtorFtype = new ast::FunctionType();
-								dtorFtype->params.emplace_back( new ast::PointerType( new ast::VoidType() ) );
-								auto dtorType = new ast::PointerType( dtorFtype );
-
-								auto destructor = new ast::ObjectDecl(loc, memberDtorNamer.newName(), new ast::StructInstType( ast::dtorStruct ), new ast::ListInit(loc, { new ast::SingleInit(loc, thisExpr ), new ast::SingleInit(loc, new ast::CastExpr( dtorExpr, dtorType ) ) } ) );
-								destructor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr({}, ast::dtorStructDestroy ) } ) );
-								mutStmts->push_front( new ast::DeclStmt(loc, destructor ) );
-								mutStmts->kids.splice( mutStmts->kids.begin(), stmtsToAdd );
-							}
-						} catch ( SemanticErrorException & error ) {
-							emit( funcDecl->location, "in ", function->name , ", field ", field->name, " not explicitly ", isCtor ? "constructed" : "destructed",  " and no ", isCtor ? "default constructor" : "destructor", " found" );
-						}
-					}
-				}
-				function->stmts = mutStmts;
-			}
-			if (! errors.isEmpty()) {
-				throw errors;
-			}
-			// return funcDecl;
-			return function;
-		}
-
-		/// true if expr is effectively just the 'this' parameter
-		bool isThisExpression( const ast::Expr * expr, const ast::DeclWithType * thisParam ) {
-			// TODO: there are more complicated ways to pass 'this' to a constructor, e.g. &*, *&, etc.
-			if ( auto varExpr = dynamic_cast< const ast::VariableExpr * >( expr ) ) {
-				return varExpr->var == thisParam;
-			} else if ( auto castExpr = dynamic_cast< const ast::CastExpr * > ( expr ) ) {
-				return isThisExpression( castExpr->arg, thisParam );
-			}
-			return false;
-		}
-
-		/// returns a MemberExpr if expr is effectively just member access on the 'this' parameter, else nullptr
-		const ast::MemberExpr * isThisMemberExpr( const ast::Expr * expr, const ast::DeclWithType * thisParam ) {
-			if ( auto memberExpr = dynamic_cast< const ast::MemberExpr * >( expr ) ) {
-				if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
-					return memberExpr;
-				}
-			} else if ( auto castExpr = dynamic_cast< const ast::CastExpr * >( expr ) ) {
-				return isThisMemberExpr( castExpr->arg, thisParam );
-			}
-			return nullptr;
-		}
-
-		void GenStructMemberCalls::previsit( const ast::ApplicationExpr * appExpr ) {
-			if ( ! checkWarnings( function ) ) {
-				visit_children = false;
-				return;
-			}
-
-			std::string fname = getFunctionName( appExpr );
-			if ( fname == function->name ) {
-				// call to same kind of function
-				const ast::Expr * firstParam = appExpr->args.front();
-
-				if ( isThisExpression( firstParam, thisParam ) ) {
-					// if calling another constructor on thisParam, assume that function handles
-					// all members - if it doesn't a warning will appear in that function.
-					unhandled.clear();
-				} else if ( auto memberExpr = isThisMemberExpr( firstParam, thisParam ) ) {
-					// if first parameter is a member expression on the this parameter,
-					// then remove the member from unhandled set.
-					if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
-						unhandled.erase( memberExpr->member );
-					}
-				}
-			}
-		}
-
-		void GenStructMemberCalls::previsit( const ast::MemberExpr * memberExpr ) {
-			if ( ! checkWarnings( function ) || ! isCtor ) {
-				visit_children = false;
-				return;
-			}
-
-			if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
-				if ( unhandled.count( memberExpr->member ) ) {
-					// emit a warning because a member was used before it was constructed
-					usedUninit.insert( { memberExpr->member, memberExpr->location } );
-				}
-			}
-		}
-
-		template< typename Visitor, typename... Params >
-		void error( Visitor & v, CodeLocation loc, const Params &... params ) {
-			SemanticErrorException err( loc, toString( params... ) );
-			v.errors.append( err );
-		}
-
-		template< typename... Params >
-		void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) {
-			// toggle warnings vs. errors here.
-			// warn( params... );
-			error( *this, loc, params... );
-		}
-
-		const ast::Expr * GenStructMemberCalls::postvisit( const ast::UntypedExpr * untypedExpr ) {
-			// Expression * newExpr = untypedExpr;
-			// xxx - functions returning ast::ptr seems wrong...
-			auto res = ResolvExpr::findVoidExpression( untypedExpr, symtab );
-			return res.release();
-			// return newExpr;
-		}
-
-		void InsertImplicitCalls::previsit(const ast::UniqueExpr * unqExpr) {
-			if (visitedIds.count(unqExpr->id)) visit_children = false;
-			else visitedIds.insert(unqExpr->id);
-		}
-
-		const ast::Expr * FixCtorExprs::postvisit( const ast::ConstructorExpr * ctorExpr ) {
-			const CodeLocation loc = ctorExpr->location;
-			static UniqueName tempNamer( "_tmp_ctor_expr" );
-			// xxx - is the size check necessary?
-			assert( ctorExpr->result && ctorExpr->result->size() == 1 );
-
-			// xxx - this can be TupleAssignExpr now. Need to properly handle this case.
-			// take possession of expr and env
-			ast::ptr<ast::ApplicationExpr> callExpr = ctorExpr->callExpr.strict_as<ast::ApplicationExpr>();
-			ast::ptr<ast::TypeSubstitution> env = ctorExpr->env;
-			// ctorExpr->set_callExpr( nullptr );
-			// ctorExpr->set_env( nullptr );
-
-			// xxx - ideally we would reuse the temporary generated from the copy constructor passes from within firstArg if it exists and not generate a temporary if it's unnecessary.
-			auto tmp = new ast::ObjectDecl(loc, tempNamer.newName(), callExpr->args.front()->result );
-			declsToAddBefore.push_back( tmp );
-			// delete ctorExpr;
-
-			// build assignment and replace constructor's first argument with new temporary
-			auto mutCallExpr = callExpr.get_and_mutate();
-			const ast::Expr * firstArg = callExpr->args.front();
-			ast::Expr * assign = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ), { new ast::AddressExpr(loc, new ast::VariableExpr(loc, tmp ) ), new ast::AddressExpr( firstArg ) } );
-			firstArg = new ast::VariableExpr(loc, tmp );
-			mutCallExpr->args.front() = firstArg;
-
-			// resolve assignment and dispose of new env
-			auto resolved = ResolvExpr::findVoidExpression( assign, symtab );
-			auto mut = resolved.get_and_mutate();
-			assertf(resolved.get() == mut, "newly resolved expression must be unique");
-			mut->env = nullptr;
-
-			// for constructor expr:
-			//   T x;
-			//   x{};
-			// results in:
-			//   T x;
-			//   T & tmp;
-			//   &tmp = &x, ?{}(tmp), tmp
-			ast::CommaExpr * commaExpr = new ast::CommaExpr(loc, resolved, new ast::CommaExpr(loc, mutCallExpr, new ast::VariableExpr(loc, tmp ) ) );
-			commaExpr->env = env;
-			return commaExpr;
-		}
-	} // namespace
+			return;
+		}
+
+		if ( isThisExpression( memberExpr->aggregate, thisParam ) ) {
+			if ( unhandled.count( memberExpr->member ) ) {
+				// emit a warning because a member was used before it was constructed
+				usedUninit.insert( { memberExpr->member, memberExpr->location } );
+			}
+		}
+	}
+
+	template< typename Visitor, typename... Params >
+	void error( Visitor & v, CodeLocation loc, const Params &... params ) {
+		SemanticErrorException err( loc, toString( params... ) );
+		v.errors.append( err );
+	}
+
+	template< typename... Params >
+	void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) {
+		// toggle warnings vs. errors here.
+		// warn( params... );
+		error( *this, loc, params... );
+	}
+
+	const ast::Expr * GenStructMemberCalls::postvisit( const ast::UntypedExpr * untypedExpr ) {
+		// Expression * newExpr = untypedExpr;
+		// xxx - functions returning ast::ptr seems wrong...
+		auto res = ResolvExpr::findVoidExpression( untypedExpr, symtab );
+		return res.release();
+		// return newExpr;
+	}
+
+	void InsertImplicitCalls::previsit(const ast::UniqueExpr * unqExpr) {
+		if (visitedIds.count(unqExpr->id)) visit_children = false;
+		else visitedIds.insert(unqExpr->id);
+	}
+
+	const ast::Expr * FixCtorExprs::postvisit( const ast::ConstructorExpr * ctorExpr ) {
+		const CodeLocation loc = ctorExpr->location;
+		static UniqueName tempNamer( "_tmp_ctor_expr" );
+		// xxx - is the size check necessary?
+		assert( ctorExpr->result && ctorExpr->result->size() == 1 );
+
+		// xxx - this can be TupleAssignExpr now. Need to properly handle this case.
+		// take possession of expr and env
+		ast::ptr<ast::ApplicationExpr> callExpr = ctorExpr->callExpr.strict_as<ast::ApplicationExpr>();
+		ast::ptr<ast::TypeSubstitution> env = ctorExpr->env;
+		// ctorExpr->set_callExpr( nullptr );
+		// ctorExpr->set_env( nullptr );
+
+		// xxx - ideally we would reuse the temporary generated from the copy constructor passes from within firstArg if it exists and not generate a temporary if it's unnecessary.
+		auto tmp = new ast::ObjectDecl(loc, tempNamer.newName(), callExpr->args.front()->result );
+		declsToAddBefore.push_back( tmp );
+		// delete ctorExpr;
+
+		// build assignment and replace constructor's first argument with new temporary
+		auto mutCallExpr = callExpr.get_and_mutate();
+		const ast::Expr * firstArg = callExpr->args.front();
+		ast::Expr * assign = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ), { new ast::AddressExpr(loc, new ast::VariableExpr(loc, tmp ) ), new ast::AddressExpr( firstArg ) } );
+		firstArg = new ast::VariableExpr(loc, tmp );
+		mutCallExpr->args.front() = firstArg;
+
+		// resolve assignment and dispose of new env
+		auto resolved = ResolvExpr::findVoidExpression( assign, symtab );
+		auto mut = resolved.get_and_mutate();
+		assertf(resolved.get() == mut, "newly resolved expression must be unique");
+		mut->env = nullptr;
+
+		// for constructor expr:
+		//   T x;
+		//   x{};
+		// results in:
+		//   T x;
+		//   T & tmp;
+		//   &tmp = &x, ?{}(tmp), tmp
+		ast::CommaExpr * commaExpr = new ast::CommaExpr(loc, resolved, new ast::CommaExpr(loc, mutCallExpr, new ast::VariableExpr(loc, tmp ) ) );
+		commaExpr->env = env;
+		return commaExpr;
+	}
+} // namespace
 } // namespace InitTweak
 
Index: tests/alloc.cfa
===================================================================
--- tests/alloc.cfa	(revision 51e7583fdb45808075dc046654f4243e2cb2e109)
+++ tests/alloc.cfa	(revision f7136f783580d39320d5c60029508f18953c397a)
@@ -342,5 +342,5 @@
 	for ( i; dim ) { printf( "%d %g, ", stp1[i].x, stp1[i].y ); }
 	printf( "\n" );
-	adelete( dim, stp, dim, stp1 );
+	adelete( stp, stp1 );
 
 	// extras
