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source: src/InitTweak/FixInit.cc @ ad6343e

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsdeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since ad6343e was 092528b, checked in by Rob Schluntz <rschlunt@…>, 8 years ago
fix copy constructing/destructing qualified argument/return temporaries
Property mode set to `100644`
File size: 48.5 KB

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1	//
2	// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3	//
4	// The contents of this file are covered under the licence agreement in the
5	// file "LICENCE" distributed with Cforall.
6	//
7	// FixInit.h --
8	//
9	// Author : Rob Schluntz
10	// Created On : Wed Jan 13 16:29:30 2016
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Tue Jul 12 17:41:15 2016
13	// Update Count : 34
14	//
15
16	#include <stack>
17	#include <list>
18	#include <iterator>
19	#include <algorithm>
20	#include <unordered_map>
21	#include <unordered_set>
22	#include "InitTweak.h"
23	#include "GenInit.h"
24	#include "FixInit.h"
25	#include "FixGlobalInit.h"
26	#include "ResolvExpr/Resolver.h"
27	#include "ResolvExpr/typeops.h"
28	#include "SynTree/Declaration.h"
29	#include "SynTree/Type.h"
30	#include "SynTree/Expression.h"
31	#include "SynTree/Attribute.h"
32	#include "SynTree/Statement.h"
33	#include "SynTree/Initializer.h"
34	#include "SynTree/Mutator.h"
35	#include "SymTab/Indexer.h"
36	#include "SymTab/Autogen.h"
37	#include "GenPoly/PolyMutator.h"
38	#include "GenPoly/DeclMutator.h"
39	#include "SynTree/AddStmtVisitor.h"
40	#include "CodeGen/GenType.h" // for warning/error messages
41	#include "Tuples/Tuples.h"
42
43	bool ctordtorp = false; // print all debug
44	bool ctorp = false; // print ctor debug
45	bool cpctorp = false; // print copy ctor debug
46	bool dtorp = false; // print dtor debug
47	#define PRINT( text ) if ( ctordtorp ) { text }
48	#define CP_CTOR_PRINT( text ) if ( ctordtorp \|\| cpctorp ) { text }
49	#define DTOR_PRINT( text ) if ( ctordtorp \|\| dtorp ) { text }
50
51	namespace InitTweak {
52	namespace {
53	typedef std::unordered_map< Expression , TypeSubstitution > EnvMap;
54
55	class InsertImplicitCalls final : public GenPoly::PolyMutator {
56	public:
57	/// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
58	/// function calls need their parameters to be copy constructed
59	static void insert( std::list< Declaration * > & translationUnit, EnvMap & envMap );
60
61	InsertImplicitCalls( EnvMap & envMap ) : envMap( envMap ) {}
62	typedef GenPoly::PolyMutator Parent;
63	using Parent::mutate;
64	virtual Expression * mutate( ApplicationExpr * appExpr ) override;
65	virtual Expression * mutate( StmtExpr * stmtExpr ) override;
66
67	// collects environments for relevant nodes
68	EnvMap & envMap;
69	};
70
71	class ResolveCopyCtors final : public SymTab::Indexer {
72	public:
73	/// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr,
74	/// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
75	/// arguments and return value temporaries
76	static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap );
77
78	typedef SymTab::Indexer Parent;
79	using Parent::visit;
80
81	ResolveCopyCtors( const EnvMap & envMap ) : envMap( envMap ) {}
82
83	virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
84	virtual void visit( UniqueExpr * unqExpr ) override;
85	virtual void visit( StmtExpr * stmtExpr ) override;
86
87	/// create and resolve ctor/dtor expression: fname(var, [cpArg])
88	Expression * makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg = NULL );
89	/// true if type does not need to be copy constructed to ensure correctness
90	bool skipCopyConstruct( Type * type );
91	void copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr );
92	void destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr );
93
94	TypeSubstitution * env;
95	const EnvMap & envMap;
96	};
97
98	/// collects constructed object decls - used as a base class
99	class ObjDeclCollector : public AddStmtVisitor {
100	public:
101	typedef AddStmtVisitor Parent;
102	using Parent::visit;
103	typedef std::set< ObjectDecl * > ObjectSet;
104	virtual void visit( CompoundStmt *compoundStmt ) override;
105	virtual void visit( DeclStmt *stmt ) override;
106	protected:
107	ObjectSet curVars;
108	};
109
110	// debug
111	struct printSet {
112	typedef ObjDeclCollector::ObjectSet ObjectSet;
113	printSet( const ObjectSet & objs ) : objs( objs ) {}
114	const ObjectSet & objs;
115	};
116	std::ostream & operator<<( std::ostream & out, const printSet & set) {
117	out << "{ ";
118	for ( ObjectDecl * obj : set.objs ) {
119	out << obj->get_name() << ", " ;
120	} // for
121	out << " }";
122	return out;
123	}
124
125	class LabelFinder final : public ObjDeclCollector {
126	public:
127	typedef ObjDeclCollector Parent;
128	typedef std::map< Label, ObjectSet > LabelMap;
129	// map of Label -> live variables at that label
130	LabelMap vars;
131
132	void handleStmt( Statement * stmt );
133
134	// xxx - This needs to be done better.
135	// allow some generalization among different kinds of nodes with with similar parentage (e.g. all
136	// expressions, all statements, etc.) important to have this to provide a single entry point so that as new
137	// subclasses are added, there is only one place that the code has to be updated, rather than ensure that
138	// every specialized class knows about every new kind of statement that might be added.
139	using Parent::visit;
140	virtual void visit( CompoundStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
141	virtual void visit( ExprStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
142	virtual void visit( AsmStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
143	virtual void visit( IfStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
144	virtual void visit( WhileStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
145	virtual void visit( ForStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
146	virtual void visit( SwitchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
147	virtual void visit( CaseStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
148	virtual void visit( BranchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
149	virtual void visit( ReturnStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
150	virtual void visit( TryStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
151	virtual void visit( CatchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
152	virtual void visit( FinallyStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
153	virtual void visit( NullStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
154	virtual void visit( DeclStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
155	virtual void visit( ImplicitCtorDtorStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
156	};
157
158	class InsertDtors final : public ObjDeclCollector {
159	public:
160	/// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed
161	/// (currently by FixInit)
162	static void insert( std::list< Declaration * > & translationUnit );
163
164	typedef ObjDeclCollector Parent;
165	typedef std::list< ObjectDecl * > OrderedDecls;
166	typedef std::list< OrderedDecls > OrderedDeclsStack;
167
168	InsertDtors( LabelFinder & finder ) : labelVars( finder.vars ) {}
169
170	using Parent::visit;
171
172	virtual void visit( ObjectDecl * objDecl ) override;
173
174	virtual void visit( CompoundStmt * compoundStmt ) override;
175	virtual void visit( ReturnStmt * returnStmt ) override;
176	virtual void visit( BranchStmt * stmt ) override;
177	private:
178	void handleGoto( BranchStmt * stmt );
179
180	LabelFinder::LabelMap & labelVars;
181	OrderedDeclsStack reverseDeclOrder;
182	};
183
184	class FixInit final : public GenPoly::PolyMutator {
185	public:
186	/// expand each object declaration to use its constructor after it is declared.
187	static void fixInitializers( std::list< Declaration * > &translationUnit );
188
189	typedef GenPoly::PolyMutator Parent;
190	using Parent::mutate;
191	virtual DeclarationWithType * mutate( ObjectDecl *objDecl ) override;
192
193	std::list< Declaration * > staticDtorDecls;
194	};
195
196	class FixCopyCtors final : public GenPoly::PolyMutator {
197	public:
198	/// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
199	/// and destructors
200	static void fixCopyCtors( std::list< Declaration * > &translationUnit );
201
202	typedef GenPoly::PolyMutator Parent;
203	using Parent::mutate;
204	virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
205	virtual Expression * mutate( UniqueExpr * unqExpr ) override;
206	virtual Expression * mutate( StmtExpr * stmtExpr ) override;
207	};
208
209	class GenStructMemberCalls final : public SymTab::Indexer {
210	public:
211	typedef Indexer Parent;
212	/// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
213	/// for any member that is missing a corresponding ctor/dtor call.
214	/// error if a member is used before constructed
215	static void generate( std::list< Declaration * > & translationUnit );
216
217	using Parent::visit;
218
219	virtual void visit( FunctionDecl * funcDecl ) override;
220
221	virtual void visit( MemberExpr * memberExpr ) override;
222	virtual void visit( ApplicationExpr * appExpr ) override;
223
224	SemanticError errors;
225	private:
226	void handleFirstParam( Expression * firstParam );
227	template< typename... Params >
228	void emit( const Params &... params );
229
230	FunctionDecl * function = 0;
231	std::set< DeclarationWithType * > unhandled, usedUninit;
232	ObjectDecl * thisParam = 0;
233	bool isCtor = false; // true if current function is a constructor
234	StructDecl * structDecl = 0;
235	};
236
237	// very simple resolver-like mutator class - used to
238	// resolve UntypedExprs that are found within newly
239	// generated constructor/destructor calls
240	class MutatingResolver final : public Mutator {
241	public:
242	MutatingResolver( SymTab::Indexer & indexer ) : indexer( indexer ) {}
243
244	using Mutator::mutate;
245	virtual DeclarationWithType* mutate( ObjectDecl *objectDecl ) override;
246	virtual Expression* mutate( UntypedExpr *untypedExpr ) override;
247
248	private:
249	SymTab::Indexer & indexer;
250	};
251
252	class FixCtorExprs final : public GenPoly::DeclMutator {
253	public:
254	/// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
255	static void fix( std::list< Declaration * > & translationUnit );
256
257	using GenPoly::DeclMutator::mutate;
258	virtual Expression * mutate( ConstructorExpr * ctorExpr ) override;
259	};
260	} // namespace
261
262	void fix( std::list< Declaration * > & translationUnit, const std::string & filename, bool inLibrary ) {
263	// fixes ConstructorInit for global variables. should happen before fixInitializers.
264	InitTweak::fixGlobalInit( translationUnit, filename, inLibrary );
265
266	EnvMap envMap;
267
268	InsertImplicitCalls::insert( translationUnit, envMap );
269	ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap );
270	InsertDtors::insert( translationUnit );
271	FixInit::fixInitializers( translationUnit );
272
273	// FixCopyCtors must happen after FixInit, so that destructors are placed correctly
274	FixCopyCtors::fixCopyCtors( translationUnit );
275
276	GenStructMemberCalls::generate( translationUnit );
277	// xxx - ctor expansion currently has to be after FixCopyCtors, because there is currently a
278	// hack in the way untyped assignments are generated, where the first argument cannot have
279	// its address taken because of the way codegeneration handles UntypedExpr vs. ApplicationExpr.
280	// Thus such assignment exprs must never pushed through expression resolution (and thus should
281	// not go through the FixCopyCtors pass), otherwise they will fail -- guaranteed.
282	// Also needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
283	// don't look right, and a member can be constructed more than once.
284	FixCtorExprs::fix( translationUnit );
285	}
286
287	namespace {
288	void InsertImplicitCalls::insert( std::list< Declaration * > & translationUnit, EnvMap & envMap ) {
289	InsertImplicitCalls inserter( envMap );
290	mutateAll( translationUnit, inserter );
291	}
292
293	void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap ) {
294	ResolveCopyCtors resolver( envMap );
295	acceptAll( translationUnit, resolver );
296	}
297
298	void FixInit::fixInitializers( std::list< Declaration * > & translationUnit ) {
299	FixInit fixer;
300
301	// can't use mutateAll, because need to insert declarations at top-level
302	// can't use DeclMutator, because sometimes need to insert IfStmt, etc.
303	SemanticError errors;
304	for ( std::list< Declaration * >::iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
305	try {
306	i = maybeMutate( i, fixer );
307	translationUnit.splice( i, fixer.staticDtorDecls );
308	} catch( SemanticError &e ) {
309	errors.append( e );
310	} // try
311	} // for
312	if ( ! errors.isEmpty() ) {
313	throw errors;
314	} // if
315	}
316
317	void InsertDtors::insert( std::list< Declaration * > & translationUnit ) {
318	LabelFinder finder;
319	InsertDtors inserter( finder );
320	acceptAll( translationUnit, finder );
321	acceptAll( translationUnit, inserter );
322	}
323
324	void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit ) {
325	FixCopyCtors fixer;
326	mutateAll( translationUnit, fixer );
327	}
328
329	void GenStructMemberCalls::generate( std::list< Declaration * > & translationUnit ) {
330	GenStructMemberCalls warner;
331	acceptAll( translationUnit, warner );
332
333	// visitor doesn't throw so that it can collect all errors
334	if ( ! warner.errors.isEmpty() ) {
335	throw warner.errors;
336	}
337	}
338
339	void FixCtorExprs::fix( std::list< Declaration * > & translationUnit ) {
340	FixCtorExprs fixer;
341	fixer.mutateDeclarationList( translationUnit );
342	}
343
344	Expression * InsertImplicitCalls::mutate( ApplicationExpr * appExpr ) {
345	appExpr = dynamic_cast< ApplicationExpr * >( Parent::mutate( appExpr ) );
346	assert( appExpr );
347
348	if ( VariableExpr * function = dynamic_cast< VariableExpr * > ( appExpr->get_function() ) ) {
349	if ( LinkageSpec::isBuiltin( function->get_var()->get_linkage() ) ) {
350	// optimization: don't need to copy construct in order to call intrinsic functions
351	return appExpr;
352	} else if ( DeclarationWithType * funcDecl = dynamic_cast< DeclarationWithType * > ( function->get_var() ) ) {
353	FunctionType * ftype = dynamic_cast< FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
354	assert( ftype );
355	if ( (isConstructor( funcDecl->get_name() ) \|\| funcDecl->get_name() == "?=?") && ftype->get_parameters().size() == 2 ) {
356	Type * t1 = ftype->get_parameters().front()->get_type();
357	Type * t2 = ftype->get_parameters().back()->get_type();
358	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( t1 );
359
360	if ( ResolvExpr::typesCompatible( ptrType->get_base(), t2, SymTab::Indexer() ) ) {
361	// optimization: don't need to copy construct in order to call a copy constructor or
362	// assignment operator
363	return appExpr;
364	} // if
365	} else if ( isDestructor( funcDecl->get_name() ) ) {
366	// correctness: never copy construct arguments to a destructor
367	return appExpr;
368	} // if
369	} // if
370	} // if
371	CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; )
372
373	// wrap each function call so that it is easy to identify nodes that have to be copy constructed
374	ImplicitCopyCtorExpr * expr = new ImplicitCopyCtorExpr( appExpr );
375	// save the type substitution into the envMap so that it is easy to find.
376	// Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion.
377	// The substitution is needed to obtain the type of temporary variables so that copy constructor
378	// calls can be resolved. Normally this is what PolyMutator is for, but the pass that resolves
379	// copy constructor calls must be an Indexer. We could alternatively make a PolyIndexer which
380	// saves the environment, or compute the types of temporaries here, but it's much simpler to
381	// save the environment here, and more cohesive to compute temporary variables and resolve copy
382	// constructor calls together.
383	assert( env );
384	envMap[expr] = env;
385	return expr;
386	}
387
388	Expression * InsertImplicitCalls::mutate( StmtExpr * stmtExpr ) {
389	assert( env );
390	envMap[stmtExpr] = env;
391	return Parent::mutate( stmtExpr );
392	}
393
394	bool ResolveCopyCtors::skipCopyConstruct( Type * type ) {
395	return dynamic_cast< VarArgsType * >( type ) \|\| GenPoly::getFunctionType( type ) \|\| Tuples::isTtype( type );
396	}
397
398	Expression * ResolveCopyCtors::makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg ) {
399	assert( var );
400	// arrays are not copy constructed, so this should always be an ExprStmt
401	ImplicitCtorDtorStmt * stmt = genCtorDtor( fname, var, cpArg );
402	ExprStmt * exprStmt = safe_dynamic_cast< ExprStmt * >( stmt->get_callStmt() );
403	Expression * untyped = exprStmt->get_expr();
404
405	// resolve copy constructor
406	// should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed
407	// (VariableExpr and already resolved expression)
408	CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; )
409	Expression * resolved = ResolvExpr::findVoidExpression( untyped, *this );
410	assert( resolved );
411	if ( resolved->get_env() ) {
412	// Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
413	env->add( *resolved->get_env() );
414	delete resolved->get_env();
415	resolved->set_env( nullptr );
416	} // if
417
418	delete stmt;
419	return resolved;
420	}
421
422	void ResolveCopyCtors::copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr ) {
423	static UniqueName tempNamer("_tmp_cp");
424	assert( env );
425	CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
426	assert( arg->has_result() );
427	Type * result = arg->get_result();
428	if ( skipCopyConstruct( result ) ) return; // skip certain non-copyable types
429
430	// type may involve type variables, so apply type substitution to get temporary variable's actual type
431	result = result->clone();
432	env->apply( result );
433	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
434	tmp->get_type()->set_isConst( false );
435
436	// create and resolve copy constructor
437	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
438	Expression * cpCtor = makeCtorDtor( "?{}", tmp, arg );
439
440	if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( cpCtor ) ) {
441	// if the chosen constructor is intrinsic, the copy is unnecessary, so
442	// don't create the temporary and don't call the copy constructor
443	VariableExpr * function = dynamic_cast< VariableExpr * >( appExpr->get_function() );
444	assert( function );
445	if ( function->get_var()->get_linkage() == LinkageSpec::Intrinsic ) return;
446	}
447
448	// replace argument to function call with temporary
449	arg = new CommaExpr( cpCtor, new VariableExpr( tmp ) );
450	impCpCtorExpr->get_tempDecls().push_back( tmp );
451	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", tmp ) );
452	}
453
454	void ResolveCopyCtors::destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr ) {
455	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
456	}
457
458	void ResolveCopyCtors::visit( ImplicitCopyCtorExpr *impCpCtorExpr ) {
459	CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
460	Parent::visit( impCpCtorExpr );
461	env = envMap.at(impCpCtorExpr);
462	assert( env );
463
464	ApplicationExpr * appExpr = impCpCtorExpr->get_callExpr();
465
466	// take each argument and attempt to copy construct it.
467	for ( Expression * & arg : appExpr->get_args() ) {
468	copyConstructArg( arg, impCpCtorExpr );
469	} // for
470
471	// each return value from the call needs to be connected with an ObjectDecl at the call site, which is
472	// initialized with the return value and is destructed later
473	// xxx - handle named return values?
474	Type * result = appExpr->get_result();
475	if ( ! result->isVoid() ) {
476	static UniqueName retNamer("_tmp_cp_ret");
477	result = result->clone();
478	env->apply( result );
479	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
480	ret->get_type()->set_isConst( false );
481	impCpCtorExpr->get_returnDecls().push_back( ret );
482	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
483	if ( ! result->get_isLvalue() ) {
484	// destructing lvalue returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
485	destructRet( ret, impCpCtorExpr );
486	}
487	} // for
488	CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
489	}
490
491	void ResolveCopyCtors::visit( StmtExpr * stmtExpr ) {
492	Parent::visit( stmtExpr );
493	env = envMap.at(stmtExpr);
494	assert( stmtExpr->get_result() );
495	Type * result = stmtExpr->get_result();
496	if ( ! result->isVoid() ) {
497	static UniqueName retNamer("_tmp_stmtexpr_ret");
498
499	// create variable that will hold the result of the stmt expr
500	result = result->clone();
501	env->apply( result );
502	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
503	ret->get_type()->set_isConst( false );
504	stmtExpr->get_returnDecls().push_front( ret );
505
506	// must have a non-empty body, otherwise it wouldn't have a result
507	CompoundStmt * body = stmtExpr->get_statements();
508	assert( ! body->get_kids().empty() );
509	// must be an ExprStmt, otherwise it wouldn't have a result
510	ExprStmt * last = safe_dynamic_cast< ExprStmt * >( body->get_kids().back() );
511	last->set_expr( makeCtorDtor( "?{}", ret, last->get_expr() ) );
512
513	stmtExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
514	} // if
515
516	}
517
518	void ResolveCopyCtors::visit( UniqueExpr * unqExpr ) {
519	static std::unordered_set< int > vars;
520	if ( vars.count( unqExpr->get_id() ) ) {
521	// xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
522	return;
523	}
524
525	Parent::visit( unqExpr );
526	// it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
527	assert( unqExpr->get_result() );
528	if ( ImplicitCopyCtorExpr * impCpCtorExpr = dynamic_cast<ImplicitCopyCtorExpr*>( unqExpr->get_expr() ) ) {
529	// note the variable used as the result from the call
530	assert( impCpCtorExpr->get_result() && impCpCtorExpr->get_returnDecls().size() == 1 );
531	unqExpr->set_var( new VariableExpr( impCpCtorExpr->get_returnDecls().front() ) );
532	} else {
533	// expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
534	unqExpr->set_object( new ObjectDecl( toString("_unq_expr_", unqExpr->get_id()), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, unqExpr->get_result()->clone(), nullptr ) );
535	unqExpr->set_var( new VariableExpr( unqExpr->get_object() ) );
536	}
537	vars.insert( unqExpr->get_id() );
538	}
539
540	Expression * FixCopyCtors::mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) {
541	CP_CTOR_PRINT( std::cerr << "FixCopyCtors: " << impCpCtorExpr << std::endl; )
542
543	impCpCtorExpr = safe_dynamic_cast< ImplicitCopyCtorExpr * >( Parent::mutate( impCpCtorExpr ) );
544	std::list< ObjectDecl * > & tempDecls = impCpCtorExpr->get_tempDecls();
545	std::list< ObjectDecl * > & returnDecls = impCpCtorExpr->get_returnDecls();
546	std::list< Expression * > & dtors = impCpCtorExpr->get_dtors();
547
548	// add all temporary declarations and their constructors
549	for ( ObjectDecl * obj : tempDecls ) {
550	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
551	} // for
552	for ( ObjectDecl * obj : returnDecls ) {
553	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
554	} // for
555
556	// add destructors after current statement
557	for ( Expression * dtor : dtors ) {
558	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
559	} // for
560
561	// xxx - update to work with multiple return values
562	ObjectDecl * returnDecl = returnDecls.empty() ? NULL : returnDecls.front();
563	Expression * callExpr = impCpCtorExpr->get_callExpr();
564
565	CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; )
566
567	// detach fields from wrapper node so that it can be deleted without deleting too much
568	dtors.clear();
569	tempDecls.clear();
570	returnDecls.clear();
571	impCpCtorExpr->set_callExpr( NULL );
572	impCpCtorExpr->set_env( NULL );
573	delete impCpCtorExpr;
574
575	if ( returnDecl ) {
576	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
577	assign->get_args().push_back( new VariableExpr( returnDecl ) );
578	assign->get_args().push_back( callExpr );
579	// know the result type of the assignment is the type of the LHS (minus the pointer), so
580	// add that onto the assignment expression so that later steps have the necessary information
581	assign->set_result( returnDecl->get_type()->clone() );
582
583	Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
584	if ( callExpr->get_result()->get_isLvalue() ) {
585	// lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
586	// non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
587	// type of the return temporary from T to T* to properly capture the return value. Then dereference
588	// the result of the comma expression, since the lvalue returning call was originally wrapped with
589	// an AddressExpr. Effectively, this turns
590	// lvalue T f();
591	// &*f();
592	// into
593	// T * f();
594	// T * tmp_cp_retN;
595	// &(tmp_cp_retN = &f(), tmp_cp_retN); // the first * and second & are generated here
596	// which work out in terms of types, but is pretty messy. It would be nice to find a better way.
597	assign->get_args().back() = new AddressExpr( assign->get_args().back() );
598
599	returnDecl->set_type( new PointerType( Type::Qualifiers(), returnDecl->get_type() ) );
600	retExpr->set_result( new PointerType( Type::Qualifiers(), retExpr->get_result() ) );
601	retExpr = UntypedExpr::createDeref( retExpr );
602	} // if
603	// move env from callExpr to retExpr
604	retExpr->set_env( callExpr->get_env() );
605	callExpr->set_env( nullptr );
606	return retExpr;
607	} else {
608	return callExpr;
609	} // if
610	}
611
612	Expression * FixCopyCtors::mutate( StmtExpr * stmtExpr ) {
613	stmtExpr = safe_dynamic_cast< StmtExpr * >( Parent::mutate( stmtExpr ) );
614	assert( stmtExpr->get_result() );
615	Type * result = stmtExpr->get_result();
616	if ( ! result->isVoid() ) {
617	for ( ObjectDecl * obj : stmtExpr->get_returnDecls() ) {
618	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
619	} // for
620	// add destructors after current statement
621	for ( Expression * dtor : stmtExpr->get_dtors() ) {
622	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
623	} // for
624	// must have a non-empty body, otherwise it wouldn't have a result
625	CompoundStmt * body = stmtExpr->get_statements();
626	assert( ! body->get_kids().empty() );
627	assert( ! stmtExpr->get_returnDecls().empty() );
628	body->get_kids().push_back( new ExprStmt( noLabels, new VariableExpr( stmtExpr->get_returnDecls().front() ) ) );
629	}
630	stmtExpr->get_returnDecls().clear();
631	stmtExpr->get_dtors().clear();
632	return stmtExpr;
633	}
634
635	Expression * FixCopyCtors::mutate( UniqueExpr * unqExpr ) {
636	static std::unordered_map< int, UniqueExpr * > unqMap;
637	static std::unordered_set< int > addDeref;
638	// has to be done to clean up ImplicitCopyCtorExpr nodes, even when this node was skipped in previous passes
639	if ( unqMap.count( unqExpr->get_id() ) ) {
640	// take data from other UniqueExpr to ensure consistency
641	delete unqExpr->get_expr();
642	unqExpr->set_expr( unqMap[unqExpr->get_id()]->get_expr()->clone() );
643	delete unqExpr->get_result();
644	unqExpr->set_result( maybeClone( unqExpr->get_expr()->get_result() ) );
645	if ( addDeref.count( unqExpr->get_id() ) ) {
646	// other UniqueExpr was dereferenced because it was an lvalue return, so this one should be too
647	return UntypedExpr::createDeref( unqExpr );
648	}
649	return unqExpr;
650	}
651	unqExpr = safe_dynamic_cast< UniqueExpr * >( Parent::mutate( unqExpr ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
652	unqMap[unqExpr->get_id()] = unqExpr;
653	if ( UntypedExpr * deref = dynamic_cast< UntypedExpr * >( unqExpr->get_expr() ) ) {
654	// unique expression is now a dereference, because the inner expression is an lvalue returning function call.
655	// Normalize the expression by dereferencing the unique expression, rather than the inner expression
656	// (i.e. move the dereference out a level)
657	assert( getFunctionName( deref ) == "*?" );
658	unqExpr->set_expr( getCallArg( deref, 0 ) );
659	getCallArg( deref, 0 ) = unqExpr;
660	addDeref.insert( unqExpr->get_id() );
661	return deref;
662	}
663	return unqExpr;
664	}
665
666	DeclarationWithType FixInit::mutate( ObjectDecl objDecl ) {
667	// first recursively handle pieces of ObjectDecl so that they aren't missed by other visitors when the init
668	// is removed from the ObjectDecl
669	objDecl = dynamic_cast< ObjectDecl * >( Parent::mutate( objDecl ) );
670	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
671	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
672	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
673	if ( Statement * ctor = ctorInit->get_ctor() ) {
674	if ( objDecl->get_storageClass() == DeclarationNode::Static ) {
675	// originally wanted to take advantage of gcc nested functions, but
676	// we get memory errors with this approach. To remedy this, the static
677	// variable is hoisted when the destructor needs to be called.
678	//
679	// generate:
680	// static T __objName_static_varN;
681	// void __objName_dtor_atexitN() {
682	// __dtor__...;
683	// }
684	// int f(...) {
685	// ...
686	// static bool __objName_uninitialized = true;
687	// if (__objName_uninitialized) {
688	// __ctor(__objName);
689	// __objName_uninitialized = false;
690	// atexit(__objName_dtor_atexitN);
691	// }
692	// ...
693	// }
694
695	static UniqueName dtorCallerNamer( "_dtor_atexit" );
696
697	// static bool __objName_uninitialized = true
698	BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
699	SingleInit * boolInitExpr = new SingleInit( new ConstantExpr( Constant( boolType->clone(), "1" ) ), noDesignators );
700	ObjectDecl * isUninitializedVar = new ObjectDecl( objDecl->get_mangleName() + "_uninitialized", DeclarationNode::Static, LinkageSpec::Cforall, 0, boolType, boolInitExpr );
701	isUninitializedVar->fixUniqueId();
702
703	// __objName_uninitialized = false;
704	UntypedExpr * setTrue = new UntypedExpr( new NameExpr( "?=?" ) );
705	setTrue->get_args().push_back( new VariableExpr( isUninitializedVar ) );
706	setTrue->get_args().push_back( new ConstantExpr( Constant( boolType->clone(), "0" ) ) );
707
708	// generate body of if
709	CompoundStmt * initStmts = new CompoundStmt( noLabels );
710	std::list< Statement * > & body = initStmts->get_kids();
711	body.push_back( ctor );
712	body.push_back( new ExprStmt( noLabels, setTrue ) );
713
714	// put it all together
715	IfStmt * ifStmt = new IfStmt( noLabels, new VariableExpr( isUninitializedVar ), initStmts, 0 );
716	stmtsToAddAfter.push_back( new DeclStmt( noLabels, isUninitializedVar ) );
717	stmtsToAddAfter.push_back( ifStmt );
718
719	if ( ctorInit->get_dtor() ) {
720	// if the object has a non-trivial destructor, have to
721	// hoist it and the object into the global space and
722	// call the destructor function with atexit.
723
724	Statement * dtorStmt = ctorInit->get_dtor()->clone();
725
726	// void __objName_dtor_atexitN(...) {...}
727	FunctionDecl * dtorCaller = new FunctionDecl( objDecl->get_mangleName() + dtorCallerNamer.newName(), DeclarationNode::Static, LinkageSpec::C, new FunctionType( Type::Qualifiers(), false ), new CompoundStmt( noLabels ), false, false );
728	dtorCaller->fixUniqueId();
729	dtorCaller->get_statements()->push_back( dtorStmt );
730
731	// atexit(dtor_atexit);
732	UntypedExpr * callAtexit = new UntypedExpr( new NameExpr( "atexit" ) );
733	callAtexit->get_args().push_back( new VariableExpr( dtorCaller ) );
734
735	body.push_back( new ExprStmt( noLabels, callAtexit ) );
736
737	// hoist variable and dtor caller decls to list of decls that will be added into global scope
738	staticDtorDecls.push_back( objDecl );
739	staticDtorDecls.push_back( dtorCaller );
740
741	// need to rename object uniquely since it now appears
742	// at global scope and there could be multiple function-scoped
743	// static variables with the same name in different functions.
744	// Note: it isn't sufficient to modify only the mangleName, because
745	// then subsequent Indexer passes can choke on seeing the object's name
746	// if another object has the same name and type. An unfortunate side-effect
747	// of renaming the object is that subsequent NameExprs may fail to resolve,
748	// but there shouldn't be any remaining past this point.
749	static UniqueName staticNamer( "_static_var" );
750	objDecl->set_name( objDecl->get_name() + staticNamer.newName() );
751	objDecl->set_mangleName( SymTab::Mangler::mangle( objDecl ) );
752
753	objDecl->set_init( NULL );
754	ctorInit->set_ctor( NULL );
755	delete ctorInit;
756
757	// xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
758	// create a new object which is never used
759	static UniqueName dummyNamer( "_dummy" );
760	ObjectDecl * dummy = new ObjectDecl( dummyNamer.newName(), DeclarationNode::Static, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), 0, std::list< Attribute * >{ new Attribute("unused") } );
761	return dummy;
762	}
763	} else {
764	stmtsToAddAfter.push_back( ctor );
765	} // if
766	objDecl->set_init( NULL );
767	ctorInit->set_ctor( NULL );
768	} else if ( Initializer * init = ctorInit->get_init() ) {
769	objDecl->set_init( init );
770	ctorInit->set_init( NULL );
771	} else {
772	// no constructor and no initializer, which is okay
773	objDecl->set_init( NULL );
774	} // if
775	delete ctorInit;
776	} // if
777	return objDecl;
778	}
779
780	void ObjDeclCollector::visit( CompoundStmt *compoundStmt ) {
781	std::set< ObjectDecl * > prevVars = curVars;
782	Parent::visit( compoundStmt );
783	curVars = prevVars;
784	}
785
786	void ObjDeclCollector::visit( DeclStmt *stmt ) {
787	// keep track of all variables currently in scope
788	if ( ObjectDecl * objDecl = dynamic_cast< ObjectDecl * > ( stmt->get_decl() ) ) {
789	curVars.insert( objDecl );
790	} // if
791	Parent::visit( stmt );
792	}
793
794	void LabelFinder::handleStmt( Statement * stmt ) {
795	// for each label, remember the variables in scope at that label.
796	for ( Label l : stmt->get_labels() ) {
797	vars[l] = curVars;
798	} // for
799	}
800
801	template<typename Iterator, typename OutputIterator>
802	void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
803	for ( Iterator it = begin ; it != end ; ++it ) {
804	// extract destructor statement from the object decl and insert it into the output. Note that this is
805	// only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
806	// calls an intrinsic dtor then the call must (and will) still be generated since the argument may
807	// contain side effects.
808	ObjectDecl * objDecl = *it;
809	ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
810	assert( ctorInit && ctorInit->get_dtor() );
811	*out++ = ctorInit->get_dtor()->clone();
812	} // for
813	}
814
815	void InsertDtors::visit( ObjectDecl * objDecl ) {
816	// remember non-static destructed objects so that their destructors can be inserted later
817	if ( objDecl->get_storageClass() != DeclarationNode::Static ) {
818	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
819	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
820	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
821	Statement * dtor = ctorInit->get_dtor();
822	if ( dtor && ! isIntrinsicSingleArgCallStmt( dtor ) ) {
823	// don't need to call intrinsic dtor, because it does nothing, but
824	// non-intrinsic dtors must be called
825	reverseDeclOrder.front().push_front( objDecl );
826	} // if
827	} // if
828	} // if
829	Parent::visit( objDecl );
830	}
831
832	void InsertDtors::visit( CompoundStmt * compoundStmt ) {
833	// visit statements - this will also populate reverseDeclOrder list. don't want to dump all destructors
834	// when block is left, just the destructors associated with variables defined in this block, so push a new
835	// list to the top of the stack so that we can differentiate scopes
836	reverseDeclOrder.push_front( OrderedDecls() );
837	Parent::visit( compoundStmt );
838
839	// add destructors for the current scope that we're exiting
840	std::list< Statement * > & statements = compoundStmt->get_kids();
841	insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
842	reverseDeclOrder.pop_front();
843	}
844
845	void InsertDtors::visit( ReturnStmt * returnStmt ) {
846	// return exits all scopes, so dump destructors for all scopes
847	for ( OrderedDecls & od : reverseDeclOrder ) {
848	insertDtors( od.begin(), od.end(), back_inserter( stmtsToAdd ) );
849	} // for
850	}
851
852	// Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the
853	// BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope
854	// at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user
855	// of the error. See C++ Reference 6.6 Jump Statements for details.
856	void InsertDtors::handleGoto( BranchStmt * stmt ) {
857	assert( stmt->get_target() != "" && "BranchStmt missing a label" );
858	// S_L = lvars = set of objects in scope at label definition
859	// S_G = curVars = set of objects in scope at goto statement
860	ObjectSet & lvars = labelVars[ stmt->get_target() ];
861
862	DTOR_PRINT(
863	std::cerr << "at goto label: " << stmt->get_target().get_name() << std::endl;
864	std::cerr << "S_G = " << printSet( curVars ) << std::endl;
865	std::cerr << "S_L = " << printSet( lvars ) << std::endl;
866	)
867
868	ObjectSet diff;
869	// S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty
870	std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) );
871	DTOR_PRINT(
872	std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl;
873	)
874	if ( ! diff.empty() ) {
875	throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
876	} // if
877	// S_G-S_L results in set of objects that must be destructed
878	diff.clear();
879	std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
880	DTOR_PRINT(
881	std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
882	)
883	if ( ! diff.empty() ) {
884	// go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
885	OrderedDecls ordered;
886	for ( OrderedDecls & rdo : reverseDeclOrder ) {
887	// add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
888	copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return diff.count( objDecl ); } );
889	} // for
890	insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAdd ) );
891	} // if
892	}
893
894	void InsertDtors::visit( BranchStmt * stmt ) {
895	switch( stmt->get_type() ) {
896	case BranchStmt::Continue:
897	case BranchStmt::Break:
898	// could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
899	// always be empty), but it serves as a small sanity check.
900	case BranchStmt::Goto:
901	handleGoto( stmt );
902	break;
903	default:
904	assert( false );
905	} // switch
906	}
907
908	bool checkWarnings( FunctionDecl * funcDecl ) {
909	// only check for warnings if the current function is a user-defined
910	// constructor or destructor
911	if ( ! funcDecl ) return false;
912	if ( ! funcDecl->get_statements() ) return false;
913	return isCtorDtor( funcDecl->get_name() ) && ! LinkageSpec::isOverridable( funcDecl->get_linkage() );
914	}
915
916	void GenStructMemberCalls::visit( FunctionDecl * funcDecl ) {
917	ValueGuard< FunctionDecl * > oldFunction( funcDecl );
918	ValueGuard< std::set< DeclarationWithType * > > oldUnhandled( unhandled );
919	ValueGuard< std::set< DeclarationWithType * > > oldUsedUninit( usedUninit );
920	ValueGuard< ObjectDecl * > oldThisParam( thisParam );
921	ValueGuard< bool > oldIsCtor( isCtor );
922	ValueGuard< StructDecl * > oldStructDecl( structDecl );
923
924	// need to start with fresh sets
925	unhandled.clear();
926	usedUninit.clear();
927
928	function = funcDecl;
929	isCtor = isConstructor( function->get_name() );
930	if ( checkWarnings( function ) ) {
931	FunctionType * type = function->get_functionType();
932	assert( ! type->get_parameters().empty() );
933	thisParam = safe_dynamic_cast< ObjectDecl * >( type->get_parameters().front() );
934	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( thisParam->get_type() );
935	StructInstType * structType = dynamic_cast< StructInstType * >( ptrType->get_base() );
936	if ( structType ) {
937	structDecl = structType->get_baseStruct();
938	for ( Declaration * member : structDecl->get_members() ) {
939	if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
940	// record all of the struct type's members that need to be constructed or
941	// destructed by the end of the function
942	unhandled.insert( field );
943	}
944	}
945	}
946	}
947	Parent::visit( function );
948
949	// remove the unhandled objects from usedUninit, because a call is inserted
950	// to handle them - only objects that are later constructed are used uninitialized.
951	std::set< DeclarationWithType * > diff;
952	std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ) );
953	for ( DeclarationWithType * member : diff ) {
954	emit( "in ", CodeGen::genType( function->get_functionType(), function->get_name(), false ), ", field ", member->get_name(), " used before being constructed" );
955	}
956
957	if ( ! unhandled.empty() ) {
958	// need to explicitly re-add function parameters in order to resolve copy constructors
959	enterScope();
960	maybeAccept( function->get_functionType(), *this );
961
962	// need to iterate through members in reverse in order for
963	// ctor/dtor statements to come out in the right order
964	for ( Declaration * member : reverseIterate( structDecl->get_members() ) ) {
965	DeclarationWithType * field = dynamic_cast< DeclarationWithType * >( member );
966	// skip non-DWT members
967	if ( ! field ) continue;
968	// skip handled members
969	if ( ! unhandled.count( field ) ) continue;
970
971	// insert and resolve default/copy constructor call for each field that's unhandled
972	std::list< Statement * > stmt;
973	UntypedExpr * deref = UntypedExpr::createDeref( new VariableExpr( thisParam ) );
974
975	Expression * arg2 = 0;
976	if ( isCopyConstructor( function ) ) {
977	// if copy ctor, need to pass second-param-of-this-function.field
978	std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
979	assert( params.size() == 2 );
980	arg2 = new MemberExpr( field, new VariableExpr( params.back() ) );
981	}
982	InitExpander srcParam( arg2 );
983	SymTab::genImplicitCall( srcParam, new MemberExpr( field, deref ), function->get_name(), back_inserter( stmt ), field, isCtor );
984
985	assert( stmt.size() <= 1 );
986	if ( stmt.size() == 1 ) {
987	Statement * callStmt = stmt.front();
988
989	MutatingResolver resolver( *this );
990	try {
991	callStmt->acceptMutator( resolver );
992	if ( isCtor ) {
993	function->get_statements()->push_front( callStmt );
994	} else {
995	// destructor statements should be added at the end
996	function->get_statements()->push_back( callStmt );
997	}
998	} catch ( SemanticError & error ) {
999	emit( "in ", CodeGen::genType( function->get_functionType(), function->get_name(), false ), ", field ", field->get_name(), " not explicitly ", isCtor ? "constructed" : "destructed", " and no ", isCtor ? "default constructor" : "destructor", " found" );
1000	}
1001	}
1002	}
1003	leaveScope();
1004	}
1005	}
1006
1007	void GenStructMemberCalls::visit( ApplicationExpr * appExpr ) {
1008	if ( ! checkWarnings( function ) ) return;
1009
1010	std::string fname = getFunctionName( appExpr );
1011	if ( fname == function->get_name() ) {
1012	// call to same kind of function
1013	Expression * firstParam = appExpr->get_args().front();
1014
1015	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( firstParam ) ) {
1016	// if calling another constructor on thisParam, assume that function handles
1017	// all members - if it doesn't a warning will appear in that function.
1018	if ( varExpr->get_var() == thisParam ) {
1019	unhandled.clear();
1020	}
1021	} else {
1022	// if first parameter is a member expression then
1023	// remove the member from unhandled set.
1024	handleFirstParam( firstParam );
1025	}
1026	}
1027
1028	Parent::visit( appExpr );
1029	}
1030
1031	void GenStructMemberCalls::handleFirstParam( Expression * firstParam ) {
1032	using namespace std;
1033	if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( firstParam ) ) {
1034	if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( addrExpr->get_arg() ) ) {
1035	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1036	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1037	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1038	if ( varExpr->get_var() == thisParam ) {
1039	unhandled.erase( memberExpr->get_member() );
1040	}
1041	}
1042	}
1043	}
1044	}
1045	}
1046	}
1047
1048	void GenStructMemberCalls::visit( MemberExpr * memberExpr ) {
1049	if ( ! checkWarnings( function ) ) return;
1050	if ( ! isCtor ) return;
1051
1052	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1053	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1054	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1055	if ( varExpr->get_var() == thisParam ) {
1056	if ( unhandled.count( memberExpr->get_member() ) ) {
1057	// emit a warning because a member was used before it was constructed
1058	usedUninit.insert( memberExpr->get_member() );
1059	}
1060	}
1061	}
1062	}
1063	}
1064	Parent::visit( memberExpr );
1065	}
1066
1067	template< typename Visitor, typename... Params >
1068	void error( Visitor & v, const Params &... params ) {
1069	v.errors.append( toString( params... ) );
1070	}
1071
1072	template< typename... Params >
1073	void GenStructMemberCalls::emit( const Params &... params ) {
1074	// toggle warnings vs. errors here.
1075	// warn( params... );
1076	error( *this, params... );
1077	}
1078
1079	DeclarationWithType * MutatingResolver::mutate( ObjectDecl *objectDecl ) {
1080	// add object to the indexer assumes that there will be no name collisions
1081	// in generated code. If this changes, add mutate methods for entities with
1082	// scope and call {enter,leave}Scope explicitly.
1083	objectDecl->accept( indexer );
1084	return objectDecl;
1085	}
1086
1087	Expression* MutatingResolver::mutate( UntypedExpr *untypedExpr ) {
1088	return safe_dynamic_cast< ApplicationExpr * >( ResolvExpr::findVoidExpression( untypedExpr, indexer ) );
1089	}
1090
1091	Expression * FixCtorExprs::mutate( ConstructorExpr * ctorExpr ) {
1092	static UniqueName tempNamer( "_tmp_ctor_expr" );
1093	// xxx - is the size check necessary?
1094	assert( ctorExpr->has_result() && ctorExpr->get_result()->size() == 1 );
1095	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, ctorExpr->get_result()->clone(), nullptr );
1096	addDeclaration( tmp );
1097
1098	// xxx - this can be TupleAssignExpr now. Need to properly handle this case.
1099	ApplicationExpr * callExpr = safe_dynamic_cast< ApplicationExpr * > ( ctorExpr->get_callExpr() );
1100	TypeSubstitution * env = ctorExpr->get_env();
1101	ctorExpr->set_callExpr( nullptr );
1102	ctorExpr->set_env( nullptr );
1103
1104	Expression *& firstArg = callExpr->get_args().front();
1105	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
1106	assign->get_args().push_back( new VariableExpr( tmp ) );
1107	assign->get_args().push_back( firstArg );
1108	assign->set_result( ctorExpr->get_result()->clone() );
1109	firstArg = assign;
1110
1111	CommaExpr * commaExpr = new CommaExpr( callExpr, new VariableExpr( tmp ) );
1112	commaExpr->set_env( env );
1113	delete ctorExpr;
1114	return commaExpr;
1115	}
1116	} // namespace
1117	} // namespace InitTweak
1118
1119	// Local Variables: //
1120	// tab-width: 4 //
1121	// mode: c++ //
1122	// compile-command: "make install" //
1123	// End: //

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