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FixInit.cc @ 66f8528

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Last change on this file since 66f8528 was 66f8528, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Merge branch 'master' into tuples

Conflicts:

src/ResolvExpr/CommonType.cc
src/tests/.expect/32/extension.txt
src/tests/.expect/32/gccExtensions.txt
src/tests/.expect/64/declarationSpecifier.txt
src/tests/.expect/64/extension.txt
src/tests/.expect/64/gccExtensions.txt
src/tests/.expect/castError.txt
src/tests/Makefile.am

Property mode set to 100644

File size: 48.7 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 "FixInit.h"
24	#include "FixGlobalInit.h"
25	#include "ResolvExpr/Resolver.h"
26	#include "ResolvExpr/typeops.h"
27	#include "SynTree/Declaration.h"
28	#include "SynTree/Type.h"
29	#include "SynTree/Expression.h"
30	#include "SynTree/Attribute.h"
31	#include "SynTree/Statement.h"
32	#include "SynTree/Initializer.h"
33	#include "SynTree/Mutator.h"
34	#include "SymTab/Indexer.h"
35	#include "SymTab/Autogen.h"
36	#include "GenPoly/PolyMutator.h"
37	#include "GenPoly/DeclMutator.h"
38	#include "SynTree/AddStmtVisitor.h"
39	#include "CodeGen/GenType.h" // for warning/error messages
40
41	bool ctordtorp = false; // print all debug
42	bool ctorp = false; // print ctor debug
43	bool cpctorp = false; // print copy ctor debug
44	bool dtorp = false; // print dtor debug
45	#define PRINT( text ) if ( ctordtorp ) { text }
46	#define CP_CTOR_PRINT( text ) if ( ctordtorp \|\| cpctorp ) { text }
47	#define DTOR_PRINT( text ) if ( ctordtorp \|\| dtorp ) { text }
48
49	namespace InitTweak {
50	namespace {
51	typedef std::unordered_map< Expression , TypeSubstitution > EnvMap;
52
53	class InsertImplicitCalls final : public GenPoly::PolyMutator {
54	public:
55	/// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
56	/// function calls need their parameters to be copy constructed
57	static void insert( std::list< Declaration * > & translationUnit, EnvMap & envMap );
58
59	InsertImplicitCalls( EnvMap & envMap ) : envMap( envMap ) {}
60	typedef GenPoly::PolyMutator Parent;
61	using Parent::mutate;
62	virtual Expression * mutate( ApplicationExpr * appExpr ) override;
63	virtual Expression * mutate( StmtExpr * stmtExpr ) override;
64
65	// collects environments for relevant nodes
66	EnvMap & envMap;
67	};
68
69	class ResolveCopyCtors final : public SymTab::Indexer {
70	public:
71	/// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr,
72	/// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
73	/// arguments and return value temporaries
74	static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap );
75
76	typedef SymTab::Indexer Parent;
77	using Parent::visit;
78
79	ResolveCopyCtors( const EnvMap & envMap ) : envMap( envMap ) {}
80
81	virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
82	virtual void visit( UniqueExpr * unqExpr ) override;
83	virtual void visit( StmtExpr * stmtExpr ) override;
84
85	/// create and resolve ctor/dtor expression: fname(var, [cpArg])
86	Expression * makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg = NULL );
87	Expression * makeCtorDtor( const std::string & fname, Expression * thisArg, Expression * cpArg = NULL );
88	/// true if type does not need to be copy constructed to ensure correctness
89	bool skipCopyConstruct( Type * type );
90	void copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr );
91	void destructRet( Expression * ret, ImplicitCopyCtorExpr * impCpCtorExpr );
92
93	TypeSubstitution * env;
94	const EnvMap & envMap;
95	};
96
97	/// collects constructed object decls - used as a base class
98	class ObjDeclCollector : public AddStmtVisitor {
99	public:
100	typedef AddStmtVisitor Parent;
101	using Parent::visit;
102	typedef std::set< ObjectDecl * > ObjectSet;
103	virtual void visit( CompoundStmt *compoundStmt ) override;
104	virtual void visit( DeclStmt *stmt ) override;
105	protected:
106	ObjectSet curVars;
107	};
108
109	// debug
110	struct printSet {
111	typedef ObjDeclCollector::ObjectSet ObjectSet;
112	printSet( const ObjectSet & objs ) : objs( objs ) {}
113	const ObjectSet & objs;
114	};
115	std::ostream & operator<<( std::ostream & out, const printSet & set) {
116	out << "{ ";
117	for ( ObjectDecl * obj : set.objs ) {
118	out << obj->get_name() << ", " ;
119	} // for
120	out << " }";
121	return out;
122	}
123
124	class LabelFinder final : public ObjDeclCollector {
125	public:
126	typedef ObjDeclCollector Parent;
127	typedef std::map< Label, ObjectSet > LabelMap;
128	// map of Label -> live variables at that label
129	LabelMap vars;
130
131	void handleStmt( Statement * stmt );
132
133	// xxx - This needs to be done better.
134	// allow some generalization among different kinds of nodes with with similar parentage (e.g. all
135	// expressions, all statements, etc.) important to have this to provide a single entry point so that as new
136	// subclasses are added, there is only one place that the code has to be updated, rather than ensure that
137	// every specialized class knows about every new kind of statement that might be added.
138	using Parent::visit;
139	virtual void visit( CompoundStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
140	virtual void visit( ExprStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
141	virtual void visit( AsmStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
142	virtual void visit( IfStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
143	virtual void visit( WhileStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
144	virtual void visit( ForStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
145	virtual void visit( SwitchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
146	virtual void visit( CaseStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
147	virtual void visit( BranchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
148	virtual void visit( ReturnStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
149	virtual void visit( TryStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
150	virtual void visit( CatchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
151	virtual void visit( FinallyStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
152	virtual void visit( NullStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
153	virtual void visit( DeclStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
154	virtual void visit( ImplicitCtorDtorStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
155	};
156
157	class InsertDtors final : public ObjDeclCollector {
158	public:
159	/// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed
160	/// (currently by FixInit)
161	static void insert( std::list< Declaration * > & translationUnit );
162
163	typedef ObjDeclCollector Parent;
164	typedef std::list< ObjectDecl * > OrderedDecls;
165	typedef std::list< OrderedDecls > OrderedDeclsStack;
166
167	InsertDtors( LabelFinder & finder ) : labelVars( finder.vars ) {}
168
169	using Parent::visit;
170
171	virtual void visit( ObjectDecl * objDecl ) override;
172
173	virtual void visit( CompoundStmt * compoundStmt ) override;
174	virtual void visit( ReturnStmt * returnStmt ) override;
175	virtual void visit( BranchStmt * stmt ) override;
176	private:
177	void handleGoto( BranchStmt * stmt );
178
179	LabelFinder::LabelMap & labelVars;
180	OrderedDeclsStack reverseDeclOrder;
181	};
182
183	class FixInit final : public GenPoly::PolyMutator {
184	public:
185	/// expand each object declaration to use its constructor after it is declared.
186	static void fixInitializers( std::list< Declaration * > &translationUnit );
187
188	typedef GenPoly::PolyMutator Parent;
189	using Parent::mutate;
190	virtual DeclarationWithType * mutate( ObjectDecl *objDecl ) override;
191
192	std::list< Declaration * > staticDtorDecls;
193	};
194
195	class FixCopyCtors final : public GenPoly::PolyMutator {
196	public:
197	/// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
198	/// and destructors
199	static void fixCopyCtors( std::list< Declaration * > &translationUnit );
200
201	typedef GenPoly::PolyMutator Parent;
202	using Parent::mutate;
203	virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
204	virtual Expression * mutate( UniqueExpr * unqExpr ) override;
205	virtual Expression * mutate( StmtExpr * stmtExpr ) override;
206	};
207
208	class GenStructMemberCalls final : public SymTab::Indexer {
209	public:
210	typedef Indexer Parent;
211	/// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
212	/// for any member that is missing a corresponding ctor/dtor call.
213	/// error if a member is used before constructed
214	static void generate( std::list< Declaration * > & translationUnit );
215
216	using Parent::visit;
217
218	virtual void visit( FunctionDecl * funcDecl ) override;
219
220	virtual void visit( MemberExpr * memberExpr ) override;
221	virtual void visit( ApplicationExpr * appExpr ) override;
222
223	SemanticError errors;
224	private:
225	void handleFirstParam( Expression * firstParam );
226	template< typename... Params >
227	void emit( const Params &... params );
228
229	FunctionDecl * function = 0;
230	std::set< DeclarationWithType * > unhandled, usedUninit;
231	ObjectDecl * thisParam = 0;
232	bool isCtor = false; // true if current function is a constructor
233	StructDecl * structDecl = 0;
234	};
235
236	// very simple resolver-like mutator class - used to
237	// resolve UntypedExprs that are found within newly
238	// generated constructor/destructor calls
239	class MutatingResolver final : public Mutator {
240	public:
241	MutatingResolver( SymTab::Indexer & indexer ) : indexer( indexer ) {}
242
243	using Mutator::mutate;
244	virtual DeclarationWithType* mutate( ObjectDecl *objectDecl ) override;
245	virtual Expression* mutate( UntypedExpr *untypedExpr ) override;
246
247	private:
248	SymTab::Indexer & indexer;
249	};
250
251	class FixCtorExprs final : public GenPoly::DeclMutator {
252	public:
253	/// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
254	static void fix( std::list< Declaration * > & translationUnit );
255
256	using GenPoly::DeclMutator::mutate;
257	virtual Expression * mutate( ConstructorExpr * ctorExpr ) override;
258	};
259	} // namespace
260
261	void fix( std::list< Declaration * > & translationUnit, const std::string & filename, bool inLibrary ) {
262	// fixes ConstructorInit for global variables. should happen before fixInitializers.
263	InitTweak::fixGlobalInit( translationUnit, filename, inLibrary );
264
265	EnvMap envMap;
266
267	InsertImplicitCalls::insert( translationUnit, envMap );
268	ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap );
269	InsertDtors::insert( translationUnit );
270	FixInit::fixInitializers( translationUnit );
271
272	// FixCopyCtors must happen after FixInit, so that destructors are placed correctly
273	FixCopyCtors::fixCopyCtors( translationUnit );
274
275	GenStructMemberCalls::generate( translationUnit );
276	// xxx - ctor expansion currently has to be after FixCopyCtors, because there is currently a
277	// hack in the way untyped assignments are generated, where the first argument cannot have
278	// its address taken because of the way codegeneration handles UntypedExpr vs. ApplicationExpr.
279	// Thus such assignment exprs must never pushed through expression resolution (and thus should
280	// not go through the FixCopyCtors pass), otherwise they will fail -- guaranteed.
281	// Also needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
282	// don't look right, and a member can be constructed more than once.
283	FixCtorExprs::fix( translationUnit );
284	}
285
286	namespace {
287	void InsertImplicitCalls::insert( std::list< Declaration * > & translationUnit, EnvMap & envMap ) {
288	InsertImplicitCalls inserter( envMap );
289	mutateAll( translationUnit, inserter );
290	}
291
292	void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap ) {
293	ResolveCopyCtors resolver( envMap );
294	acceptAll( translationUnit, resolver );
295	}
296
297	void FixInit::fixInitializers( std::list< Declaration * > & translationUnit ) {
298	FixInit fixer;
299
300	// can't use mutateAll, because need to insert declarations at top-level
301	// can't use DeclMutator, because sometimes need to insert IfStmt, etc.
302	SemanticError errors;
303	for ( std::list< Declaration * >::iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
304	try {
305	i = maybeMutate( i, fixer );
306	translationUnit.splice( i, fixer.staticDtorDecls );
307	} catch( SemanticError &e ) {
308	errors.append( e );
309	} // try
310	} // for
311	if ( ! errors.isEmpty() ) {
312	throw errors;
313	} // if
314	}
315
316	void InsertDtors::insert( std::list< Declaration * > & translationUnit ) {
317	LabelFinder finder;
318	InsertDtors inserter( finder );
319	acceptAll( translationUnit, finder );
320	acceptAll( translationUnit, inserter );
321	}
322
323	void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit ) {
324	FixCopyCtors fixer;
325	mutateAll( translationUnit, fixer );
326	}
327
328	void GenStructMemberCalls::generate( std::list< Declaration * > & translationUnit ) {
329	GenStructMemberCalls warner;
330	acceptAll( translationUnit, warner );
331
332	// visitor doesn't throw so that it can collect all errors
333	if ( ! warner.errors.isEmpty() ) {
334	throw warner.errors;
335	}
336	}
337
338	void FixCtorExprs::fix( std::list< Declaration * > & translationUnit ) {
339	FixCtorExprs fixer;
340	fixer.mutateDeclarationList( translationUnit );
341	}
342
343	Expression * InsertImplicitCalls::mutate( ApplicationExpr * appExpr ) {
344	appExpr = dynamic_cast< ApplicationExpr * >( Parent::mutate( appExpr ) );
345	assert( appExpr );
346
347	if ( VariableExpr * function = dynamic_cast< VariableExpr * > ( appExpr->get_function() ) ) {
348	if ( LinkageSpec::isBuiltin( function->get_var()->get_linkage() ) ) {
349	// optimization: don't need to copy construct in order to call intrinsic functions
350	return appExpr;
351	} else if ( DeclarationWithType * funcDecl = dynamic_cast< DeclarationWithType * > ( function->get_var() ) ) {
352	FunctionType * ftype = dynamic_cast< FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
353	assert( ftype );
354	if ( (isConstructor( funcDecl->get_name() ) \|\| funcDecl->get_name() == "?=?") && ftype->get_parameters().size() == 2 ) {
355	Type * t1 = ftype->get_parameters().front()->get_type();
356	Type * t2 = ftype->get_parameters().back()->get_type();
357	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( t1 );
358
359	if ( ResolvExpr::typesCompatible( ptrType->get_base(), t2, SymTab::Indexer() ) ) {
360	// optimization: don't need to copy construct in order to call a copy constructor or
361	// assignment operator
362	return appExpr;
363	} // if
364	} else if ( isDestructor( funcDecl->get_name() ) ) {
365	// correctness: never copy construct arguments to a destructor
366	return appExpr;
367	} // if
368	} // if
369	} // if
370	CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; )
371
372	// wrap each function call so that it is easy to identify nodes that have to be copy constructed
373	ImplicitCopyCtorExpr * expr = new ImplicitCopyCtorExpr( appExpr );
374	// save the type substitution into the envMap so that it is easy to find.
375	// Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion.
376	// The substitution is needed to obtain the type of temporary variables so that copy constructor
377	// calls can be resolved. Normally this is what PolyMutator is for, but the pass that resolves
378	// copy constructor calls must be an Indexer. We could alternatively make a PolyIndexer which
379	// saves the environment, or compute the types of temporaries here, but it's much simpler to
380	// save the environment here, and more cohesive to compute temporary variables and resolve copy
381	// constructor calls together.
382	assert( env );
383	envMap[expr] = env;
384	return expr;
385	}
386
387	Expression * InsertImplicitCalls::mutate( StmtExpr * stmtExpr ) {
388	assert( env );
389	envMap[stmtExpr] = env;
390	return Parent::mutate( stmtExpr );
391	}
392
393	bool ResolveCopyCtors::skipCopyConstruct( Type * type ) {
394	return dynamic_cast< VarArgsType * >( type ) \|\| GenPoly::getFunctionType( type );
395	}
396
397	Expression * ResolveCopyCtors::makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg ) {
398	assert( var );
399	return makeCtorDtor( fname, new AddressExpr( new VariableExpr( var ) ), cpArg );
400	}
401
402	Expression * ResolveCopyCtors::makeCtorDtor( const std::string & fname, Expression * thisArg, Expression * cpArg ) {
403	assert( thisArg );
404	UntypedExpr * untyped = new UntypedExpr( new NameExpr( fname ) );
405	untyped->get_args().push_back( thisArg );
406	if (cpArg) untyped->get_args().push_back( cpArg->clone() );
407
408	// resolve copy constructor
409	// should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed
410	// (VariableExpr and already resolved expression)
411	CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; )
412	Expression * resolved = ResolvExpr::findVoidExpression( untyped, *this );
413	assert( resolved );
414	if ( resolved->get_env() ) {
415	// Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
416	env->add( *resolved->get_env() );
417	delete resolved->get_env();
418	resolved->set_env( nullptr );
419	} // if
420
421	delete untyped;
422	return resolved;
423	}
424
425	void ResolveCopyCtors::copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr ) {
426	static UniqueName tempNamer("_tmp_cp");
427	assert( env );
428	CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
429	assert( arg->has_result() );
430	Type * result = arg->get_result();
431	if ( skipCopyConstruct( result ) ) return; // skip certain non-copyable types
432
433	// type may involve type variables, so apply type substitution to get temporary variable's actual type
434	result = result->clone();
435	env->apply( result );
436	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
437	tmp->get_type()->set_isConst( false );
438
439	// create and resolve copy constructor
440	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
441	Expression * cpCtor = makeCtorDtor( "?{}", tmp, arg );
442
443	if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( cpCtor ) ) {
444	// if the chosen constructor is intrinsic, the copy is unnecessary, so
445	// don't create the temporary and don't call the copy constructor
446	VariableExpr * function = dynamic_cast< VariableExpr * >( appExpr->get_function() );
447	assert( function );
448	if ( function->get_var()->get_linkage() == LinkageSpec::Intrinsic ) return;
449	}
450
451	// replace argument to function call with temporary
452	arg = new CommaExpr( cpCtor, new VariableExpr( tmp ) );
453	impCpCtorExpr->get_tempDecls().push_back( tmp );
454	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", tmp ) );
455	}
456
457	void ResolveCopyCtors::destructRet( Expression * ret, ImplicitCopyCtorExpr * impCpCtorExpr ) {
458	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", new AddressExpr( ret ) ) );
459	}
460
461	void ResolveCopyCtors::visit( ImplicitCopyCtorExpr *impCpCtorExpr ) {
462	CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
463	Parent::visit( impCpCtorExpr );
464	env = envMap.at(impCpCtorExpr);
465	assert( env );
466
467	ApplicationExpr * appExpr = impCpCtorExpr->get_callExpr();
468
469	// take each argument and attempt to copy construct it.
470	for ( Expression * & arg : appExpr->get_args() ) {
471	copyConstructArg( arg, impCpCtorExpr );
472	} // for
473
474	// each return value from the call needs to be connected with an ObjectDecl at the call site, which is
475	// initialized with the return value and is destructed later
476	// xxx - handle named return values?
477	Type * result = appExpr->get_result();
478	if ( ! result->isVoid() ) {
479	static UniqueName retNamer("_tmp_cp_ret");
480	result = result->clone();
481	env->apply( result );
482	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
483	ret->get_type()->set_isConst( false );
484	impCpCtorExpr->get_returnDecls().push_back( ret );
485	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
486	if ( ! result->get_isLvalue() ) {
487	// destructing lvalue returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
488	destructRet( new VariableExpr( ret ), impCpCtorExpr );
489	}
490	} // for
491	CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
492	}
493
494	void ResolveCopyCtors::visit( StmtExpr * stmtExpr ) {
495	Parent::visit( stmtExpr );
496	env = envMap.at(stmtExpr);
497	assert( stmtExpr->get_result() );
498	Type * result = stmtExpr->get_result();
499	if ( ! result->isVoid() ) {
500	static UniqueName retNamer("_tmp_stmtexpr_ret");
501
502	// create variable that will hold the result of the stmt expr
503	result = result->clone();
504	env->apply( result );
505	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, result, 0 );
506	ret->get_type()->set_isConst( false );
507	stmtExpr->get_returnDecls().push_front( ret );
508
509	// must have a non-empty body, otherwise it wouldn't have a result
510	CompoundStmt * body = stmtExpr->get_statements();
511	assert( ! body->get_kids().empty() );
512	// must be an ExprStmt, otherwise it wouldn't have a result
513	ExprStmt * last = safe_dynamic_cast< ExprStmt * >( body->get_kids().back() );
514	last->set_expr( makeCtorDtor( "?{}", ret, last->get_expr() ) );
515
516	stmtExpr->get_dtors().push_front( makeCtorDtor( "^?{}", new AddressExpr( new VariableExpr( ret ) ) ) );
517	} // if
518
519	}
520
521	void ResolveCopyCtors::visit( UniqueExpr * unqExpr ) {
522	static std::unordered_set< int > vars;
523	if ( vars.count( unqExpr->get_id() ) ) {
524	// xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
525	return;
526	}
527
528	Parent::visit( unqExpr );
529	// it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
530	assert( unqExpr->get_result() );
531	if ( ImplicitCopyCtorExpr * impCpCtorExpr = dynamic_cast<ImplicitCopyCtorExpr*>( unqExpr->get_expr() ) ) {
532	// note the variable used as the result from the call
533	assert( impCpCtorExpr->get_result() && impCpCtorExpr->get_returnDecls().size() == 1 );
534	unqExpr->set_var( new VariableExpr( impCpCtorExpr->get_returnDecls().front() ) );
535	} else {
536	// expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
537	unqExpr->set_object( new ObjectDecl( toString("_unq_expr_", unqExpr->get_id()), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, unqExpr->get_result()->clone(), nullptr ) );
538	unqExpr->set_var( new VariableExpr( unqExpr->get_object() ) );
539	}
540	vars.insert( unqExpr->get_id() );
541	}
542
543	Expression * FixCopyCtors::mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) {
544	CP_CTOR_PRINT( std::cerr << "FixCopyCtors: " << impCpCtorExpr << std::endl; )
545
546	impCpCtorExpr = safe_dynamic_cast< ImplicitCopyCtorExpr * >( Parent::mutate( impCpCtorExpr ) );
547	std::list< ObjectDecl * > & tempDecls = impCpCtorExpr->get_tempDecls();
548	std::list< ObjectDecl * > & returnDecls = impCpCtorExpr->get_returnDecls();
549	std::list< Expression * > & dtors = impCpCtorExpr->get_dtors();
550
551	// add all temporary declarations and their constructors
552	for ( ObjectDecl * obj : tempDecls ) {
553	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
554	} // for
555	for ( ObjectDecl * obj : returnDecls ) {
556	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
557	} // for
558
559	// add destructors after current statement
560	for ( Expression * dtor : dtors ) {
561	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
562	} // for
563
564	// xxx - update to work with multiple return values
565	ObjectDecl * returnDecl = returnDecls.empty() ? NULL : returnDecls.front();
566	Expression * callExpr = impCpCtorExpr->get_callExpr();
567
568	CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; )
569
570	// detach fields from wrapper node so that it can be deleted without deleting too much
571	dtors.clear();
572	tempDecls.clear();
573	returnDecls.clear();
574	impCpCtorExpr->set_callExpr( NULL );
575	impCpCtorExpr->set_env( NULL );
576	delete impCpCtorExpr;
577
578	if ( returnDecl ) {
579	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
580	assign->get_args().push_back( new VariableExpr( returnDecl ) );
581	assign->get_args().push_back( callExpr );
582	// know the result type of the assignment is the type of the LHS (minus the pointer), so
583	// add that onto the assignment expression so that later steps have the necessary information
584	assign->set_result( returnDecl->get_type()->clone() );
585
586	Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
587	if ( callExpr->get_result()->get_isLvalue() ) {
588	// lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
589	// non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
590	// type of the return temporary from T to T* to properly capture the return value. Then dereference
591	// the result of the comma expression, since the lvalue returning call was originally wrapped with
592	// an AddressExpr. Effectively, this turns
593	// lvalue T f();
594	// &*f();
595	// into
596	// T * f();
597	// T * tmp_cp_retN;
598	// &(tmp_cp_retN = &f(), tmp_cp_retN); // the first * and second & are generated here
599	// which work out in terms of types, but is pretty messy. It would be nice to find a better way.
600	assign->get_args().back() = new AddressExpr( assign->get_args().back() );
601
602	returnDecl->set_type( new PointerType( Type::Qualifiers(), returnDecl->get_type() ) );
603	retExpr->set_result( new PointerType( Type::Qualifiers(), retExpr->get_result() ) );
604	retExpr = UntypedExpr::createDeref( retExpr );
605	} // if
606	// move env from callExpr to retExpr
607	retExpr->set_env( callExpr->get_env() );
608	callExpr->set_env( nullptr );
609	return retExpr;
610	} else {
611	return callExpr;
612	} // if
613	}
614
615	Expression * FixCopyCtors::mutate( StmtExpr * stmtExpr ) {
616	stmtExpr = safe_dynamic_cast< StmtExpr * >( Parent::mutate( stmtExpr ) );
617	assert( stmtExpr->get_result() );
618	Type * result = stmtExpr->get_result();
619	if ( ! result->isVoid() ) {
620	for ( ObjectDecl * obj : stmtExpr->get_returnDecls() ) {
621	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
622	} // for
623	// add destructors after current statement
624	for ( Expression * dtor : stmtExpr->get_dtors() ) {
625	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
626	} // for
627	// must have a non-empty body, otherwise it wouldn't have a result
628	CompoundStmt * body = stmtExpr->get_statements();
629	assert( ! body->get_kids().empty() );
630	assert( ! stmtExpr->get_returnDecls().empty() );
631	body->get_kids().push_back( new ExprStmt( noLabels, new VariableExpr( stmtExpr->get_returnDecls().front() ) ) );
632	}
633	stmtExpr->get_returnDecls().clear();
634	stmtExpr->get_dtors().clear();
635	return stmtExpr;
636	}
637
638	Expression * FixCopyCtors::mutate( UniqueExpr * unqExpr ) {
639	static std::unordered_map< int, UniqueExpr * > unqMap;
640	static std::unordered_set< int > addDeref;
641	// has to be done to clean up ImplicitCopyCtorExpr nodes, even when this node was skipped in previous passes
642	if ( unqMap.count( unqExpr->get_id() ) ) {
643	// take data from other UniqueExpr to ensure consistency
644	delete unqExpr->get_expr();
645	unqExpr->set_expr( unqMap[unqExpr->get_id()]->get_expr()->clone() );
646	delete unqExpr->get_result();
647	unqExpr->set_result( maybeClone( unqExpr->get_expr()->get_result() ) );
648	if ( addDeref.count( unqExpr->get_id() ) ) {
649	// other UniqueExpr was dereferenced because it was an lvalue return, so this one should be too
650	return UntypedExpr::createDeref( unqExpr );
651	}
652	return unqExpr;
653	}
654	unqExpr = safe_dynamic_cast< UniqueExpr * >( Parent::mutate( unqExpr ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
655	unqMap[unqExpr->get_id()] = unqExpr;
656	if ( UntypedExpr * deref = dynamic_cast< UntypedExpr * >( unqExpr->get_expr() ) ) {
657	// unique expression is now a dereference, because the inner expression is an lvalue returning function call.
658	// Normalize the expression by dereferencing the unique expression, rather than the inner expression
659	// (i.e. move the dereference out a level)
660	assert( getFunctionName( deref ) == "*?" );
661	unqExpr->set_expr( getCallArg( deref, 0 ) );
662	getCallArg( deref, 0 ) = unqExpr;
663	addDeref.insert( unqExpr->get_id() );
664	return deref;
665	}
666	return unqExpr;
667	}
668
669	DeclarationWithType FixInit::mutate( ObjectDecl objDecl ) {
670	// first recursively handle pieces of ObjectDecl so that they aren't missed by other visitors when the init
671	// is removed from the ObjectDecl
672	objDecl = dynamic_cast< ObjectDecl * >( Parent::mutate( objDecl ) );
673	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
674	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
675	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
676	if ( Statement * ctor = ctorInit->get_ctor() ) {
677	if ( objDecl->get_storageClass() == DeclarationNode::Static ) {
678	// originally wanted to take advantage of gcc nested functions, but
679	// we get memory errors with this approach. To remedy this, the static
680	// variable is hoisted when the destructor needs to be called.
681	//
682	// generate:
683	// static T __objName_static_varN;
684	// void __objName_dtor_atexitN() {
685	// __dtor__...;
686	// }
687	// int f(...) {
688	// ...
689	// static bool __objName_uninitialized = true;
690	// if (__objName_uninitialized) {
691	// __ctor(__objName);
692	// __objName_uninitialized = false;
693	// atexit(__objName_dtor_atexitN);
694	// }
695	// ...
696	// }
697
698	static UniqueName dtorCallerNamer( "_dtor_atexit" );
699
700	// static bool __objName_uninitialized = true
701	BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
702	SingleInit * boolInitExpr = new SingleInit( new ConstantExpr( Constant( boolType->clone(), "1" ) ), noDesignators );
703	ObjectDecl * isUninitializedVar = new ObjectDecl( objDecl->get_mangleName() + "_uninitialized", DeclarationNode::Static, LinkageSpec::Cforall, 0, boolType, boolInitExpr );
704	isUninitializedVar->fixUniqueId();
705
706	// __objName_uninitialized = false;
707	UntypedExpr * setTrue = new UntypedExpr( new NameExpr( "?=?" ) );
708	setTrue->get_args().push_back( new VariableExpr( isUninitializedVar ) );
709	setTrue->get_args().push_back( new ConstantExpr( Constant( boolType->clone(), "0" ) ) );
710
711	// generate body of if
712	CompoundStmt * initStmts = new CompoundStmt( noLabels );
713	std::list< Statement * > & body = initStmts->get_kids();
714	body.push_back( ctor );
715	body.push_back( new ExprStmt( noLabels, setTrue ) );
716
717	// put it all together
718	IfStmt * ifStmt = new IfStmt( noLabels, new VariableExpr( isUninitializedVar ), initStmts, 0 );
719	stmtsToAddAfter.push_back( new DeclStmt( noLabels, isUninitializedVar ) );
720	stmtsToAddAfter.push_back( ifStmt );
721
722	if ( ctorInit->get_dtor() ) {
723	// if the object has a non-trivial destructor, have to
724	// hoist it and the object into the global space and
725	// call the destructor function with atexit.
726
727	Statement * dtorStmt = ctorInit->get_dtor()->clone();
728
729	// void __objName_dtor_atexitN(...) {...}
730	FunctionDecl * dtorCaller = new FunctionDecl( objDecl->get_mangleName() + dtorCallerNamer.newName(), DeclarationNode::Static, LinkageSpec::C, new FunctionType( Type::Qualifiers(), false ), new CompoundStmt( noLabels ), false, false );
731	dtorCaller->fixUniqueId();
732	dtorCaller->get_statements()->push_back( dtorStmt );
733
734	// atexit(dtor_atexit);
735	UntypedExpr * callAtexit = new UntypedExpr( new NameExpr( "atexit" ) );
736	callAtexit->get_args().push_back( new VariableExpr( dtorCaller ) );
737
738	body.push_back( new ExprStmt( noLabels, callAtexit ) );
739
740	// hoist variable and dtor caller decls to list of decls that will be added into global scope
741	staticDtorDecls.push_back( objDecl );
742	staticDtorDecls.push_back( dtorCaller );
743
744	// need to rename object uniquely since it now appears
745	// at global scope and there could be multiple function-scoped
746	// static variables with the same name in different functions.
747	// Note: it isn't sufficient to modify only the mangleName, because
748	// then subsequent Indexer passes can choke on seeing the object's name
749	// if another object has the same name and type. An unfortunate side-effect
750	// of renaming the object is that subsequent NameExprs may fail to resolve,
751	// but there shouldn't be any remaining past this point.
752	static UniqueName staticNamer( "_static_var" );
753	objDecl->set_name( objDecl->get_name() + staticNamer.newName() );
754	objDecl->set_mangleName( SymTab::Mangler::mangle( objDecl ) );
755
756	objDecl->set_init( NULL );
757	ctorInit->set_ctor( NULL );
758	delete ctorInit;
759
760	// xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
761	// create a new object which is never used
762	static UniqueName dummyNamer( "_dummy" );
763	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") } );
764	return dummy;
765	}
766	} else {
767	stmtsToAddAfter.push_back( ctor );
768	} // if
769	objDecl->set_init( NULL );
770	ctorInit->set_ctor( NULL );
771	} else if ( Initializer * init = ctorInit->get_init() ) {
772	objDecl->set_init( init );
773	ctorInit->set_init( NULL );
774	} else {
775	// no constructor and no initializer, which is okay
776	objDecl->set_init( NULL );
777	} // if
778	delete ctorInit;
779	} // if
780	return objDecl;
781	}
782
783	void ObjDeclCollector::visit( CompoundStmt *compoundStmt ) {
784	std::set< ObjectDecl * > prevVars = curVars;
785	Parent::visit( compoundStmt );
786	curVars = prevVars;
787	}
788
789	void ObjDeclCollector::visit( DeclStmt *stmt ) {
790	// keep track of all variables currently in scope
791	if ( ObjectDecl * objDecl = dynamic_cast< ObjectDecl * > ( stmt->get_decl() ) ) {
792	curVars.insert( objDecl );
793	} // if
794	Parent::visit( stmt );
795	}
796
797	void LabelFinder::handleStmt( Statement * stmt ) {
798	// for each label, remember the variables in scope at that label.
799	for ( Label l : stmt->get_labels() ) {
800	vars[l] = curVars;
801	} // for
802	}
803
804	template<typename Iterator, typename OutputIterator>
805	void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
806	for ( Iterator it = begin ; it != end ; ++it ) {
807	// extract destructor statement from the object decl and insert it into the output. Note that this is
808	// only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
809	// calls an intrinsic dtor then the call must (and will) still be generated since the argument may
810	// contain side effects.
811	ObjectDecl * objDecl = *it;
812	ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
813	assert( ctorInit && ctorInit->get_dtor() );
814	*out++ = ctorInit->get_dtor()->clone();
815	} // for
816	}
817
818	void InsertDtors::visit( ObjectDecl * objDecl ) {
819	// remember non-static destructed objects so that their destructors can be inserted later
820	if ( objDecl->get_storageClass() != DeclarationNode::Static ) {
821	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
822	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
823	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
824	Statement * dtor = ctorInit->get_dtor();
825	if ( dtor && ! isIntrinsicSingleArgCallStmt( dtor ) ) {
826	// don't need to call intrinsic dtor, because it does nothing, but
827	// non-intrinsic dtors must be called
828	reverseDeclOrder.front().push_front( objDecl );
829	} // if
830	} // if
831	} // if
832	Parent::visit( objDecl );
833	}
834
835	void InsertDtors::visit( CompoundStmt * compoundStmt ) {
836	// visit statements - this will also populate reverseDeclOrder list. don't want to dump all destructors
837	// when block is left, just the destructors associated with variables defined in this block, so push a new
838	// list to the top of the stack so that we can differentiate scopes
839	reverseDeclOrder.push_front( OrderedDecls() );
840	Parent::visit( compoundStmt );
841
842	// add destructors for the current scope that we're exiting
843	std::list< Statement * > & statements = compoundStmt->get_kids();
844	insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
845	reverseDeclOrder.pop_front();
846	}
847
848	void InsertDtors::visit( ReturnStmt * returnStmt ) {
849	// return exits all scopes, so dump destructors for all scopes
850	for ( OrderedDecls & od : reverseDeclOrder ) {
851	insertDtors( od.begin(), od.end(), back_inserter( stmtsToAdd ) );
852	} // for
853	}
854
855	// Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the
856	// BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope
857	// at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user
858	// of the error. See C++ Reference 6.6 Jump Statements for details.
859	void InsertDtors::handleGoto( BranchStmt * stmt ) {
860	assert( stmt->get_target() != "" && "BranchStmt missing a label" );
861	// S_L = lvars = set of objects in scope at label definition
862	// S_G = curVars = set of objects in scope at goto statement
863	ObjectSet & lvars = labelVars[ stmt->get_target() ];
864
865	DTOR_PRINT(
866	std::cerr << "at goto label: " << stmt->get_target().get_name() << std::endl;
867	std::cerr << "S_G = " << printSet( curVars ) << std::endl;
868	std::cerr << "S_L = " << printSet( lvars ) << std::endl;
869	)
870
871	ObjectSet diff;
872	// S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty
873	std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) );
874	DTOR_PRINT(
875	std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl;
876	)
877	if ( ! diff.empty() ) {
878	throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
879	} // if
880	// S_G-S_L results in set of objects that must be destructed
881	diff.clear();
882	std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
883	DTOR_PRINT(
884	std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
885	)
886	if ( ! diff.empty() ) {
887	// go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
888	OrderedDecls ordered;
889	for ( OrderedDecls & rdo : reverseDeclOrder ) {
890	// add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
891	copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return diff.count( objDecl ); } );
892	} // for
893	insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAdd ) );
894	} // if
895	}
896
897	void InsertDtors::visit( BranchStmt * stmt ) {
898	switch( stmt->get_type() ) {
899	case BranchStmt::Continue:
900	case BranchStmt::Break:
901	// could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
902	// always be empty), but it serves as a small sanity check.
903	case BranchStmt::Goto:
904	handleGoto( stmt );
905	break;
906	default:
907	assert( false );
908	} // switch
909	}
910
911	bool checkWarnings( FunctionDecl * funcDecl ) {
912	// only check for warnings if the current function is a user-defined
913	// constructor or destructor
914	if ( ! funcDecl ) return false;
915	if ( ! funcDecl->get_statements() ) return false;
916	return isCtorDtor( funcDecl->get_name() ) && ! LinkageSpec::isOverridable( funcDecl->get_linkage() );
917	}
918
919	void GenStructMemberCalls::visit( FunctionDecl * funcDecl ) {
920	ValueGuard< FunctionDecl * > oldFunction( funcDecl );
921	ValueGuard< std::set< DeclarationWithType * > > oldUnhandled( unhandled );
922	ValueGuard< std::set< DeclarationWithType * > > oldUsedUninit( usedUninit );
923	ValueGuard< ObjectDecl * > oldThisParam( thisParam );
924	ValueGuard< bool > oldIsCtor( isCtor );
925	ValueGuard< StructDecl * > oldStructDecl( structDecl );
926
927	// need to start with fresh sets
928	unhandled.clear();
929	usedUninit.clear();
930
931	function = funcDecl;
932	isCtor = isConstructor( function->get_name() );
933	if ( checkWarnings( function ) ) {
934	FunctionType * type = function->get_functionType();
935	assert( ! type->get_parameters().empty() );
936	thisParam = safe_dynamic_cast< ObjectDecl * >( type->get_parameters().front() );
937	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( thisParam->get_type() );
938	StructInstType * structType = dynamic_cast< StructInstType * >( ptrType->get_base() );
939	if ( structType ) {
940	structDecl = structType->get_baseStruct();
941	for ( Declaration * member : structDecl->get_members() ) {
942	if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
943	// record all of the struct type's members that need to be constructed or
944	// destructed by the end of the function
945	unhandled.insert( field );
946	}
947	}
948	}
949	}
950	Parent::visit( function );
951
952	// remove the unhandled objects from usedUninit, because a call is inserted
953	// to handle them - only objects that are later constructed are used uninitialized.
954	std::set< DeclarationWithType * > diff;
955	std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ) );
956	for ( DeclarationWithType * member : diff ) {
957	emit( "in ", CodeGen::genType( function->get_functionType(), function->get_name(), false ), ", field ", member->get_name(), " used before being constructed" );
958	}
959
960	if ( ! unhandled.empty() ) {
961	// need to explicitly re-add function parameters in order to resolve copy constructors
962	enterScope();
963	maybeAccept( function->get_functionType(), *this );
964
965	// need to iterate through members in reverse in order for
966	// ctor/dtor statements to come out in the right order
967	for ( Declaration * member : reverseIterate( structDecl->get_members() ) ) {
968	DeclarationWithType * field = dynamic_cast< DeclarationWithType * >( member );
969	// skip non-DWT members
970	if ( ! field ) continue;
971	// skip handled members
972	if ( ! unhandled.count( field ) ) continue;
973
974	// insert and resolve default/copy constructor call for each field that's unhandled
975	std::list< Statement * > stmt;
976	UntypedExpr * deref = UntypedExpr::createDeref( new VariableExpr( thisParam ) );
977
978	Expression * arg2 = 0;
979	if ( isCopyConstructor( function ) ) {
980	// if copy ctor, need to pass second-param-of-this-function.field
981	std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
982	assert( params.size() == 2 );
983	arg2 = new MemberExpr( field, new VariableExpr( params.back() ) );
984	}
985	InitExpander srcParam( arg2 );
986	SymTab::genImplicitCall( srcParam, new MemberExpr( field, deref ), function->get_name(), back_inserter( stmt ), field, isCtor );
987
988	assert( stmt.size() <= 1 );
989	if ( stmt.size() == 1 ) {
990	Statement * callStmt = stmt.front();
991
992	MutatingResolver resolver( *this );
993	try {
994	callStmt->acceptMutator( resolver );
995	if ( isCtor ) {
996	function->get_statements()->push_front( callStmt );
997	} else {
998	// destructor statements should be added at the end
999	function->get_statements()->push_back( callStmt );
1000	}
1001	} catch ( SemanticError & error ) {
1002	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" );
1003	}
1004	}
1005	}
1006	leaveScope();
1007	}
1008	}
1009
1010	void GenStructMemberCalls::visit( ApplicationExpr * appExpr ) {
1011	if ( ! checkWarnings( function ) ) return;
1012
1013	std::string fname = getFunctionName( appExpr );
1014	if ( fname == function->get_name() ) {
1015	// call to same kind of function
1016	Expression * firstParam = appExpr->get_args().front();
1017
1018	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( firstParam ) ) {
1019	// if calling another constructor on thisParam, assume that function handles
1020	// all members - if it doesn't a warning will appear in that function.
1021	if ( varExpr->get_var() == thisParam ) {
1022	unhandled.clear();
1023	}
1024	} else {
1025	// if first parameter is a member expression then
1026	// remove the member from unhandled set.
1027	handleFirstParam( firstParam );
1028	}
1029	}
1030
1031	Parent::visit( appExpr );
1032	}
1033
1034	void GenStructMemberCalls::handleFirstParam( Expression * firstParam ) {
1035	using namespace std;
1036	if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( firstParam ) ) {
1037	if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( addrExpr->get_arg() ) ) {
1038	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1039	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1040	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1041	if ( varExpr->get_var() == thisParam ) {
1042	unhandled.erase( memberExpr->get_member() );
1043	}
1044	}
1045	}
1046	}
1047	}
1048	}
1049	}
1050
1051	void GenStructMemberCalls::visit( MemberExpr * memberExpr ) {
1052	if ( ! checkWarnings( function ) ) return;
1053	if ( ! isCtor ) return;
1054
1055	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1056	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1057	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1058	if ( varExpr->get_var() == thisParam ) {
1059	if ( unhandled.count( memberExpr->get_member() ) ) {
1060	// emit a warning because a member was used before it was constructed
1061	usedUninit.insert( memberExpr->get_member() );
1062	}
1063	}
1064	}
1065	}
1066	}
1067	Parent::visit( memberExpr );
1068	}
1069
1070	template< typename Visitor, typename... Params >
1071	void error( Visitor & v, const Params &... params ) {
1072	v.errors.append( toString( params... ) );
1073	}
1074
1075	template< typename... Params >
1076	void GenStructMemberCalls::emit( const Params &... params ) {
1077	// toggle warnings vs. errors here.
1078	// warn( params... );
1079	error( *this, params... );
1080	}
1081
1082	DeclarationWithType * MutatingResolver::mutate( ObjectDecl *objectDecl ) {
1083	// add object to the indexer assumes that there will be no name collisions
1084	// in generated code. If this changes, add mutate methods for entities with
1085	// scope and call {enter,leave}Scope explicitly.
1086	objectDecl->accept( indexer );
1087	return objectDecl;
1088	}
1089
1090	Expression* MutatingResolver::mutate( UntypedExpr *untypedExpr ) {
1091	return safe_dynamic_cast< ApplicationExpr * >( ResolvExpr::findVoidExpression( untypedExpr, indexer ) );
1092	}
1093
1094	Expression * FixCtorExprs::mutate( ConstructorExpr * ctorExpr ) {
1095	static UniqueName tempNamer( "_tmp_ctor_expr" );
1096	// xxx - is the size check necessary?
1097	assert( ctorExpr->has_result() && ctorExpr->get_result()->size() == 1 );
1098	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, ctorExpr->get_result()->clone(), nullptr );
1099	addDeclaration( tmp );
1100
1101	ApplicationExpr * callExpr = safe_dynamic_cast< ApplicationExpr * > ( ctorExpr->get_callExpr() );
1102	TypeSubstitution * env = ctorExpr->get_env();
1103	ctorExpr->set_callExpr( nullptr );
1104	ctorExpr->set_env( nullptr );
1105
1106	Expression *& firstArg = callExpr->get_args().front();
1107	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
1108	assign->get_args().push_back( new VariableExpr( tmp ) );
1109	assign->get_args().push_back( firstArg );
1110	assign->set_result( ctorExpr->get_result()->clone() );
1111	firstArg = assign;
1112
1113	CommaExpr * commaExpr = new CommaExpr( callExpr, new VariableExpr( tmp ) );
1114	commaExpr->set_env( env );
1115	delete ctorExpr;
1116	return commaExpr;
1117	}
1118	} // namespace
1119	} // namespace InitTweak
1120
1121	// Local Variables: //
1122	// tab-width: 4 //
1123	// mode: c++ //
1124	// compile-command: "make install" //
1125	// End: //

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source: src/InitTweak/FixInit.cc @ 66f8528

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