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source: src/ResolvExpr/Resolver.cc @ 0588d8c

ADTarm-ehast-experimentalcleanup-dtorsenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum

Last change on this file since 0588d8c was 5170d95, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago
fix implict void cast problem
Property mode set to `100644`
File size: 34.4 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	// Resolver.cc --
8	//
9	// Author : Richard C. Bilson
10	// Created On : Sun May 17 12:17:01 2015
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Tue Feb 19 18:09:56 2019
13	// Update Count : 240
14	//
15
16	#include <cassert> // for strict_dynamic_cast, assert
17	#include <memory> // for allocator, allocator_traits<...
18	#include <tuple> // for get
19	#include <vector> // for vector
20
21	#include "Alternative.h" // for Alternative, AltList
22	#include "AlternativeFinder.h" // for AlternativeFinder, resolveIn...
23	#include "Common/PassVisitor.h" // for PassVisitor
24	#include "Common/SemanticError.h" // for SemanticError
25	#include "Common/utility.h" // for ValueGuard, group_iterate
26	#include "CurrentObject.h" // for CurrentObject
27	#include "InitTweak/GenInit.h"
28	#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
29	#include "RenameVars.h" // for RenameVars, global_renamer
30	#include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment
31	#include "Resolver.h"
32	#include "ResolvMode.h" // for ResolvMode
33	#include "SymTab/Autogen.h" // for SizeType
34	#include "SymTab/Indexer.h" // for Indexer
35	#include "SynTree/Declaration.h" // for ObjectDecl, TypeDecl, Declar...
36	#include "SynTree/Expression.h" // for Expression, CastExpr, InitExpr
37	#include "SynTree/Initializer.h" // for ConstructorInit, SingleInit
38	#include "SynTree/Statement.h" // for ForStmt, Statement, BranchStmt
39	#include "SynTree/Type.h" // for Type, BasicType, PointerType
40	#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
41	#include "SynTree/Visitor.h" // for acceptAll, maybeAccept
42	#include "Tuples/Tuples.h"
43	#include "typeops.h" // for extractResultType
44	#include "Unify.h" // for unify
45
46	using namespace std;
47
48	namespace ResolvExpr {
49	struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
50	Resolver() {}
51	Resolver( const SymTab::Indexer & other ) {
52	indexer = other;
53	}
54
55	void previsit( FunctionDecl * functionDecl );
56	void postvisit( FunctionDecl * functionDecl );
57	void previsit( ObjectDecl * objectDecll );
58	void previsit( EnumDecl * enumDecl );
59	void previsit( StaticAssertDecl * assertDecl );
60
61	void previsit( ArrayType * at );
62	void previsit( PointerType * at );
63
64	void previsit( ExprStmt * exprStmt );
65	void previsit( AsmExpr * asmExpr );
66	void previsit( AsmStmt * asmStmt );
67	void previsit( IfStmt * ifStmt );
68	void previsit( WhileStmt * whileStmt );
69	void previsit( ForStmt * forStmt );
70	void previsit( SwitchStmt * switchStmt );
71	void previsit( CaseStmt * caseStmt );
72	void previsit( BranchStmt * branchStmt );
73	void previsit( ReturnStmt * returnStmt );
74	void previsit( ThrowStmt * throwStmt );
75	void previsit( CatchStmt * catchStmt );
76	void previsit( WaitForStmt * stmt );
77
78	void previsit( SingleInit * singleInit );
79	void previsit( ListInit * listInit );
80	void previsit( ConstructorInit * ctorInit );
81	private:
82	typedef std::list< Initializer * >::iterator InitIterator;
83
84	template< typename PtrType >
85	void handlePtrType( PtrType * type );
86
87	void fallbackInit( ConstructorInit * ctorInit );
88
89	Type * functionReturn = nullptr;
90	CurrentObject currentObject = nullptr;
91	bool inEnumDecl = false;
92	};
93
94	struct ResolveWithExprs : public WithIndexer, public WithGuards, public WithVisitorRef<ResolveWithExprs>, public WithShortCircuiting, public WithStmtsToAdd {
95	void previsit( FunctionDecl * );
96	void previsit( WithStmt * );
97
98	void resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts );
99	};
100
101	void resolve( std::list< Declaration * > translationUnit ) {
102	PassVisitor<Resolver> resolver;
103	acceptAll( translationUnit, resolver );
104	}
105
106	void resolveDecl( Declaration * decl, const SymTab::Indexer & indexer ) {
107	PassVisitor<Resolver> resolver( indexer );
108	maybeAccept( decl, resolver );
109	}
110
111	namespace {
112	struct DeleteFinder : public WithShortCircuiting {
113	DeletedExpr * delExpr = nullptr;
114	void previsit( DeletedExpr * expr ) {
115	if ( delExpr ) visit_children = false;
116	else delExpr = expr;
117	}
118
119	void previsit( Expression * ) {
120	if ( delExpr ) visit_children = false;
121	}
122	};
123	}
124
125	DeletedExpr * findDeletedExpr( Expression * expr ) {
126	PassVisitor<DeleteFinder> finder;
127	expr->accept( finder );
128	return finder.pass.delExpr;
129	}
130
131	namespace {
132	struct StripCasts {
133	Expression * postmutate( CastExpr * castExpr ) {
134	if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
135	// generated cast is to the same type as its argument, so it's unnecessary -- remove it
136	Expression * expr = castExpr->arg;
137	castExpr->arg = nullptr;
138	std::swap( expr->env, castExpr->env );
139	return expr;
140	}
141	return castExpr;
142	}
143
144	static void strip( Expression *& expr ) {
145	PassVisitor<StripCasts> stripper;
146	expr = expr->acceptMutator( stripper );
147	}
148	};
149
150	void finishExpr( Expression & expr, const TypeEnvironment & env, TypeSubstitution oldenv = nullptr ) {
151	expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
152	env.makeSubstitution( *expr->env );
153	StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
154	}
155
156	void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
157	if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
158	if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
159	// cast is to the same type as its argument, so it's unnecessary -- remove it
160	expr = castExpr->arg;
161	castExpr->arg = nullptr;
162	std::swap( expr->env, castExpr->env );
163	delete castExpr;
164	}
165	}
166	}
167	} // namespace
168
169	namespace {
170	void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{} ) {
171	assertf( untyped, "expected a non-null expression." );
172
173	// xxx - this isn't thread-safe, but should work until we parallelize the resolver
174	static unsigned recursion_level = 0;
175
176	++recursion_level;
177	TypeEnvironment env;
178	AlternativeFinder finder( indexer, env );
179	finder.find( untyped, recursion_level == 1 ? mode.atTopLevel() : mode );
180	--recursion_level;
181
182	#if 0
183	if ( finder.get_alternatives().size() != 1 ) {
184	std::cerr << "untyped expr is ";
185	untyped->print( std::cerr );
186	std::cerr << std::endl << "alternatives are:";
187	for ( const Alternative & alt : finder.get_alternatives() ) {
188	alt.print( std::cerr );
189	} // for
190	} // if
191	#endif
192
193	// produce filtered list of alternatives
194	AltList candidates;
195	for ( Alternative & alt : finder.get_alternatives() ) {
196	if ( pred( alt ) ) {
197	candidates.push_back( std::move( alt ) );
198	}
199	}
200
201	// produce invalid error if no candidates
202	if ( candidates.empty() ) {
203	SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
204	}
205
206	// search for cheapest candidate
207	AltList winners;
208	bool seen_undeleted = false;
209	for ( unsigned i = 0; i < candidates.size(); ++i ) {
210	int c = winners.empty() ? -1 : candidates[i].cost.compare( winners.front().cost );
211
212	if ( c > 0 ) continue; // skip more expensive than winner
213
214	if ( c < 0 ) {
215	// reset on new cheapest
216	seen_undeleted = ! findDeletedExpr( candidates[i].expr );
217	winners.clear();
218	} else /* if ( c == 0 ) */ {
219	if ( findDeletedExpr( candidates[i].expr ) ) {
220	// skip deleted expression if already seen one equivalent-cost not
221	if ( seen_undeleted ) continue;
222	} else if ( ! seen_undeleted ) {
223	// replace list of equivalent-cost deleted expressions with one non-deleted
224	winners.clear();
225	seen_undeleted = true;
226	}
227	}
228
229	winners.emplace_back( std::move( candidates[i] ) );
230	}
231
232	// promote alternative.cvtCost to .cost
233	// xxx - I don't know why this is done, but I'm keeping the behaviour from findMinCost
234	for ( Alternative& winner : winners ) {
235	winner.cost = winner.cvtCost;
236	}
237
238	// produce ambiguous errors, if applicable
239	if ( winners.size() != 1 ) {
240	std::ostringstream stream;
241	stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
242	untyped->print( stream );
243	stream << " Alternatives are:\n";
244	printAlts( winners, stream, 1 );
245	SemanticError( untyped->location, stream.str() );
246	}
247
248	// single selected choice
249	Alternative& choice = winners.front();
250
251	// fail on only expression deleted
252	if ( ! seen_undeleted ) {
253	SemanticError( untyped->location, choice.expr, "Unique best alternative includes deleted identifier in " );
254	}
255
256	// xxx - check for ambiguous expressions
257
258	// output selected choice
259	alt = std::move( choice );
260	}
261
262	/// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
263	void findKindExpression(Expression *& untyped, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{}) {
264	if ( ! untyped ) return;
265	Alternative choice;
266	findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, mode );
267	finishExpr( choice.expr, choice.env, untyped->env );
268	delete untyped;
269	untyped = choice.expr;
270	choice.expr = nullptr;
271	}
272
273	bool standardAlternativeFilter( const Alternative & ) {
274	// currently don't need to filter, under normal circumstances.
275	// in the future, this may be useful for removing deleted expressions
276	return true;
277	}
278	} // namespace
279
280	// used in resolveTypeof
281	Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer ) {
282	TypeEnvironment env;
283	return resolveInVoidContext( expr, indexer, env );
284	}
285
286	Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer, TypeEnvironment & env ) {
287	// it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
288	// interpretations, an exception has already been thrown.
289	assertf( expr, "expected a non-null expression." );
290
291	CastExpr * untyped = new CastExpr( expr ); // cast to void
292	untyped->location = expr->location;
293
294	// set up and resolve expression cast to void
295	Alternative choice;
296	findUnfinishedKindExpression( untyped, choice, indexer, "", standardAlternativeFilter, ResolvMode::withAdjustment() );
297	CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
298	assert( castExpr );
299	env = std::move( choice.env );
300
301	// clean up resolved expression
302	Expression * ret = castExpr->arg;
303	castExpr->arg = nullptr;
304
305	// unlink the arg so that it isn't deleted twice at the end of the program
306	untyped->arg = nullptr;
307	return ret;
308	}
309
310	void findVoidExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
311	resetTyVarRenaming();
312	TypeEnvironment env;
313	Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
314	finishExpr( newExpr, env, untyped->env );
315	delete untyped;
316	untyped = newExpr;
317	}
318
319	void findSingleExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
320	findKindExpression( untyped, indexer, "", standardAlternativeFilter );
321	}
322
323	void findSingleExpression( Expression & untyped, Type type, const SymTab::Indexer & indexer ) {
324	assert( untyped && type );
325	// transfer location to generated cast for error purposes
326	CodeLocation location = untyped->location;
327	untyped = new CastExpr( untyped, type );
328	untyped->location = location;
329	findSingleExpression( untyped, indexer );
330	removeExtraneousCast( untyped, indexer );
331	}
332
333	namespace {
334	bool isIntegralType( const Alternative & alt ) {
335	Type * type = alt.expr->result;
336	if ( dynamic_cast< EnumInstType * >( type ) ) {
337	return true;
338	} else if ( BasicType * bt = dynamic_cast< BasicType * >( type ) ) {
339	return bt->isInteger();
340	} else if ( dynamic_cast< ZeroType* >( type ) != nullptr \|\| dynamic_cast< OneType* >( type ) != nullptr ) {
341	return true;
342	} else {
343	return false;
344	} // if
345	}
346
347	void findIntegralExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
348	findKindExpression( untyped, indexer, "condition", isIntegralType );
349	}
350	}
351
352
353	bool isStructOrUnion( const Alternative & alt ) {
354	Type * t = alt.expr->result->stripReferences();
355	return dynamic_cast< StructInstType * >( t ) \|\| dynamic_cast< UnionInstType * >( t );
356	}
357
358	void resolveWithExprs( std::list< Declaration * > & translationUnit ) {
359	PassVisitor<ResolveWithExprs> resolver;
360	acceptAll( translationUnit, resolver );
361	}
362
363	void ResolveWithExprs::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
364	for ( Expression *& expr : withExprs ) {
365	// only struct- and union-typed expressions are viable candidates
366	findKindExpression( expr, indexer, "with statement", isStructOrUnion );
367
368	// if with expression might be impure, create a temporary so that it is evaluated once
369	if ( Tuples::maybeImpure( expr ) ) {
370	static UniqueName tmpNamer( "_with_tmp_" );
371	ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
372	expr = new VariableExpr( tmp );
373	newStmts.push_back( new DeclStmt( tmp ) );
374	if ( InitTweak::isConstructable( tmp->type ) ) {
375	// generate ctor/dtor and resolve them
376	tmp->init = InitTweak::genCtorInit( tmp );
377	tmp->accept( *visitor );
378	}
379	}
380	}
381	}
382
383	void ResolveWithExprs::previsit( WithStmt * withStmt ) {
384	resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
385	}
386
387	void ResolveWithExprs::previsit( FunctionDecl * functionDecl ) {
388	{
389	// resolve with-exprs with parameters in scope and add any newly generated declarations to the
390	// front of the function body.
391	auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
392	indexer.addFunctionType( functionDecl->type );
393	std::list< Statement * > newStmts;
394	resolveWithExprs( functionDecl->withExprs, newStmts );
395	if ( functionDecl->statements ) {
396	functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
397	} else {
398	assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
399	}
400	}
401	}
402
403	void Resolver::previsit( ObjectDecl * objectDecl ) {
404	// To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that
405	// class-variable initContext is changed multiple time because the LHS is analysed twice.
406	// The second analysis changes initContext because of a function type can contain object
407	// declarations in the return and parameter types. So each value of initContext is
408	// retained, so the type on the first analysis is preserved and used for selecting the RHS.
409	GuardValue( currentObject );
410	currentObject = CurrentObject( objectDecl->get_type() );
411	if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
412	// enumerator initializers should not use the enum type to initialize, since
413	// the enum type is still incomplete at this point. Use signed int instead.
414	currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
415	}
416	}
417
418	template< typename PtrType >
419	void Resolver::handlePtrType( PtrType * type ) {
420	if ( type->get_dimension() ) {
421	findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
422	}
423	}
424
425	void Resolver::previsit( ArrayType * at ) {
426	handlePtrType( at );
427	}
428
429	void Resolver::previsit( PointerType * pt ) {
430	handlePtrType( pt );
431	}
432
433	void Resolver::previsit( FunctionDecl * functionDecl ) {
434	#if 0
435	std::cerr << "resolver visiting functiondecl ";
436	functionDecl->print( std::cerr );
437	std::cerr << std::endl;
438	#endif
439	GuardValue( functionReturn );
440	functionReturn = ResolvExpr::extractResultType( functionDecl->type );
441	}
442
443	void Resolver::postvisit( FunctionDecl * functionDecl ) {
444	// default value expressions have an environment which shouldn't be there and trips up
445	// later passes.
446	// xxx - it might be necessary to somehow keep the information from this environment, but I
447	// can't currently see how it's useful.
448	for ( Declaration * d : functionDecl->type->parameters ) {
449	if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
450	if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
451	delete init->value->env;
452	init->value->env = nullptr;
453	}
454	}
455	}
456	}
457
458	void Resolver::previsit( EnumDecl * ) {
459	// in case we decide to allow nested enums
460	GuardValue( inEnumDecl );
461	inEnumDecl = true;
462	}
463
464	void Resolver::previsit( StaticAssertDecl * assertDecl ) {
465	findIntegralExpression( assertDecl->condition, indexer );
466	}
467
468	void Resolver::previsit( ExprStmt * exprStmt ) {
469	visit_children = false;
470	assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
471	findVoidExpression( exprStmt->expr, indexer );
472	}
473
474	void Resolver::previsit( AsmExpr * asmExpr ) {
475	visit_children = false;
476	findVoidExpression( asmExpr->operand, indexer );
477	if ( asmExpr->get_inout() ) {
478	findVoidExpression( asmExpr->inout, indexer );
479	} // if
480	}
481
482	void Resolver::previsit( AsmStmt * asmStmt ) {
483	visit_children = false;
484	acceptAll( asmStmt->get_input(), *visitor );
485	acceptAll( asmStmt->get_output(), *visitor );
486	}
487
488	void Resolver::previsit( IfStmt * ifStmt ) {
489	findIntegralExpression( ifStmt->condition, indexer );
490	}
491
492	void Resolver::previsit( WhileStmt * whileStmt ) {
493	findIntegralExpression( whileStmt->condition, indexer );
494	}
495
496	void Resolver::previsit( ForStmt * forStmt ) {
497	if ( forStmt->condition ) {
498	findIntegralExpression( forStmt->condition, indexer );
499	} // if
500
501	if ( forStmt->increment ) {
502	findVoidExpression( forStmt->increment, indexer );
503	} // if
504	}
505
506	void Resolver::previsit( SwitchStmt * switchStmt ) {
507	GuardValue( currentObject );
508	findIntegralExpression( switchStmt->condition, indexer );
509
510	currentObject = CurrentObject( switchStmt->condition->result );
511	}
512
513	void Resolver::previsit( CaseStmt * caseStmt ) {
514	if ( caseStmt->condition ) {
515	std::list< InitAlternative > initAlts = currentObject.getOptions();
516	assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
517	// must remove cast from case statement because RangeExpr cannot be cast.
518	Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
519	findSingleExpression( newExpr, indexer );
520	// case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
521	// Ideally we would perform the conversion internally here.
522	if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
523	newExpr = castExpr->arg;
524	castExpr->arg = nullptr;
525	std::swap( newExpr->env, castExpr->env );
526	delete castExpr;
527	}
528	caseStmt->condition = newExpr;
529	}
530	}
531
532	void Resolver::previsit( BranchStmt * branchStmt ) {
533	visit_children = false;
534	// must resolve the argument for a computed goto
535	if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
536	if ( branchStmt->computedTarget ) {
537	// computed goto argument is void *
538	findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
539	} // if
540	} // if
541	}
542
543	void Resolver::previsit( ReturnStmt * returnStmt ) {
544	visit_children = false;
545	if ( returnStmt->expr ) {
546	findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
547	} // if
548	}
549
550	void Resolver::previsit( ThrowStmt * throwStmt ) {
551	visit_children = false;
552	// TODO: Replace *exception type with &exception type.
553	if ( throwStmt->get_expr() ) {
554	StructDecl * exception_decl =
555	indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
556	assert( exception_decl );
557	Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
558	findSingleExpression( throwStmt->expr, exceptType, indexer );
559	}
560	}
561
562	void Resolver::previsit( CatchStmt * catchStmt ) {
563	if ( catchStmt->cond ) {
564	findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
565	}
566	}
567
568	template< typename iterator_t >
569	inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
570	while( it != end && !(*it)->get_type()->get_mutex() ) {
571	it++;
572	}
573
574	return it != end;
575	}
576
577	void Resolver::previsit( WaitForStmt * stmt ) {
578	visit_children = false;
579
580	// Resolve all clauses first
581	for( auto& clause : stmt->clauses ) {
582
583	TypeEnvironment env;
584	AlternativeFinder funcFinder( indexer, env );
585
586	// Find all alternatives for a function in canonical form
587	funcFinder.findWithAdjustment( clause.target.function );
588
589	if ( funcFinder.get_alternatives().empty() ) {
590	stringstream ss;
591	ss << "Use of undeclared indentifier '";
592	ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
593	ss << "' in call to waitfor";
594	SemanticError( stmt->location, ss.str() );
595	}
596
597	if(clause.target.arguments.empty()) {
598	SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
599	}
600
601	// Find all alternatives for all arguments in canonical form
602	std::vector< AlternativeFinder > argAlternatives;
603	funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
604
605	// List all combinations of arguments
606	std::vector< AltList > possibilities;
607	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
608
609	AltList func_candidates;
610	std::vector< AltList > args_candidates;
611
612	// For every possible function :
613	// try matching the arguments to the parameters
614	// not the other way around because we have more arguments than parameters
615	SemanticErrorException errors;
616	for ( Alternative & func : funcFinder.get_alternatives() ) {
617	try {
618	PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
619	if( !pointer ) {
620	SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
621	}
622
623	FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
624	if( !function ) {
625	SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
626	}
627
628
629	{
630	auto param = function->parameters.begin();
631	auto param_end = function->parameters.end();
632
633	if( !advance_to_mutex( param, param_end ) ) {
634	SemanticError(function, "candidate function not viable: no mutex parameters\n");
635	}
636	}
637
638	Alternative newFunc( func );
639	// Strip reference from function
640	referenceToRvalueConversion( newFunc.expr, newFunc.cost );
641
642	// For all the set of arguments we have try to match it with the parameter of the current function alternative
643	for ( auto & argsList : possibilities ) {
644
645	try {
646	// Declare data structures need for resolution
647	OpenVarSet openVars;
648	AssertionSet resultNeed, resultHave;
649	TypeEnvironment resultEnv( func.env );
650	makeUnifiableVars( function, openVars, resultNeed );
651	// add all type variables as open variables now so that those not used in the parameter
652	// list are still considered open.
653	resultEnv.add( function->forall );
654
655	// Load type variables from arguemnts into one shared space
656	simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
657
658	// Make sure we don't widen any existing bindings
659	resultEnv.forbidWidening();
660
661	// Find any unbound type variables
662	resultEnv.extractOpenVars( openVars );
663
664	auto param = function->parameters.begin();
665	auto param_end = function->parameters.end();
666
667	int n_mutex_param = 0;
668
669	// For every arguments of its set, check if it matches one of the parameter
670	// The order is important
671	for( auto & arg : argsList ) {
672
673	// Ignore non-mutex arguments
674	if( !advance_to_mutex( param, param_end ) ) {
675	// We ran out of parameters but still have arguments
676	// this function doesn't match
677	SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_param, "\n" ));
678	}
679
680	n_mutex_param++;
681
682	// Check if the argument matches the parameter type in the current scope
683	if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
684	// Type doesn't match
685	stringstream ss;
686	ss << "candidate function not viable: no known convertion from '";
687	(*param)->get_type()->print( ss );
688	ss << "' to '";
689	arg.expr->get_result()->print( ss );
690	ss << "' with env '";
691	resultEnv.print(ss);
692	ss << "'\n";
693	SemanticError( function, ss.str() );
694	}
695
696	param++;
697	}
698
699	// All arguments match !
700
701	// Check if parameters are missing
702	if( advance_to_mutex( param, param_end ) ) {
703	do {
704	n_mutex_param++;
705	param++;
706	} while( advance_to_mutex( param, param_end ) );
707
708	// We ran out of arguments but still have parameters left
709	// this function doesn't match
710	SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_param, "\n" ));
711	}
712
713	// All parameters match !
714
715	// Finish the expressions to tie in the proper environments
716	finishExpr( newFunc.expr, resultEnv );
717	for( Alternative & alt : argsList ) {
718	finishExpr( alt.expr, resultEnv );
719	}
720
721	// This is a match store it and save it for later
722	func_candidates.push_back( newFunc );
723	args_candidates.push_back( argsList );
724
725	}
726	catch( SemanticErrorException & e ) {
727	errors.append( e );
728	}
729	}
730	}
731	catch( SemanticErrorException & e ) {
732	errors.append( e );
733	}
734	}
735
736	// Make sure we got the right number of arguments
737	if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
738	if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
739	if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
740	if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
741	// TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
742
743	// Swap the results from the alternative with the unresolved values.
744	// Alternatives will handle deletion on destruction
745	std::swap( clause.target.function, func_candidates.front().expr );
746	for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
747	std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
748	}
749
750	// Resolve the conditions as if it were an IfStmt
751	// Resolve the statments normally
752	findSingleExpression( clause.condition, this->indexer );
753	clause.statement->accept( *visitor );
754	}
755
756
757	if( stmt->timeout.statement ) {
758	// Resolve the timeout as an size_t for now
759	// Resolve the conditions as if it were an IfStmt
760	// Resolve the statments normally
761	findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
762	findSingleExpression( stmt->timeout.condition, this->indexer );
763	stmt->timeout.statement->accept( *visitor );
764	}
765
766	if( stmt->orelse.statement ) {
767	// Resolve the conditions as if it were an IfStmt
768	// Resolve the statments normally
769	findSingleExpression( stmt->orelse.condition, this->indexer );
770	stmt->orelse.statement->accept( *visitor );
771	}
772	}
773
774	template< typename T >
775	bool isCharType( T t ) {
776	if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
777	return bt->get_kind() == BasicType::Char \|\| bt->get_kind() == BasicType::SignedChar \|\|
778	bt->get_kind() == BasicType::UnsignedChar;
779	}
780	return false;
781	}
782
783	void Resolver::previsit( SingleInit * singleInit ) {
784	visit_children = false;
785	// resolve initialization using the possibilities as determined by the currentObject cursor
786	Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
787	findSingleExpression( newExpr, indexer );
788	InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
789
790	// move cursor to the object that is actually initialized
791	currentObject.setNext( initExpr->get_designation() );
792
793	// discard InitExpr wrapper and retain relevant pieces
794	newExpr = initExpr->expr;
795	initExpr->expr = nullptr;
796	std::swap( initExpr->env, newExpr->env );
797	// InitExpr may have inferParams in the case where the expression specializes a function
798	// pointer, and newExpr may already have inferParams of its own, so a simple swap is not
799	// sufficient.
800	newExpr->spliceInferParams( initExpr );
801	delete initExpr;
802
803	// get the actual object's type (may not exactly match what comes back from the resolver
804	// due to conversions)
805	Type * initContext = currentObject.getCurrentType();
806
807	removeExtraneousCast( newExpr, indexer );
808
809	// check if actual object's type is char[]
810	if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
811	if ( isCharType( at->get_base() ) ) {
812	// check if the resolved type is char *
813	if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
814	if ( isCharType( pt->get_base() ) ) {
815	if ( CastExpr * ce = dynamic_cast< CastExpr * >( newExpr ) ) {
816	// strip cast if we're initializing a char[] with a char *,
817	// e.g. char x[] = "hello";
818	newExpr = ce->get_arg();
819	ce->set_arg( nullptr );
820	std::swap( ce->env, newExpr->env );
821	delete ce;
822	}
823	}
824	}
825	}
826	}
827
828	// set initializer expr to resolved express
829	singleInit->value = newExpr;
830
831	// move cursor to next object in preparation for next initializer
832	currentObject.increment();
833	}
834
835	void Resolver::previsit( ListInit * listInit ) {
836	visit_children = false;
837	// move cursor into brace-enclosed initializer-list
838	currentObject.enterListInit();
839	// xxx - fix this so that the list isn't copied, iterator should be used to change current
840	// element
841	std::list<Designation *> newDesignations;
842	for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
843	// iterate designations and initializers in pairs, moving the cursor to the current
844	// designated object and resolving the initializer against that object.
845	Designation * des = std::get<0>(p);
846	Initializer * init = std::get<1>(p);
847	newDesignations.push_back( currentObject.findNext( des ) );
848	init->accept( *visitor );
849	}
850	// set the set of 'resolved' designations and leave the brace-enclosed initializer-list
851	listInit->get_designations() = newDesignations; // xxx - memory management
852	currentObject.exitListInit();
853
854	// xxx - this part has not be folded into CurrentObject yet
855	// } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
856	// Type * base = tt->get_baseType()->get_base();
857	// if ( base ) {
858	// // know the implementation type, so try using that as the initContext
859	// ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
860	// currentObject = &tmpObj;
861	// visit( listInit );
862	// } else {
863	// // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
864	// Parent::visit( listInit );
865	// }
866	// } else {
867	}
868
869	// ConstructorInit - fall back on C-style initializer
870	void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
871	// could not find valid constructor, or found an intrinsic constructor
872	// fall back on C-style initializer
873	delete ctorInit->get_ctor();
874	ctorInit->set_ctor( nullptr );
875	delete ctorInit->get_dtor();
876	ctorInit->set_dtor( nullptr );
877	maybeAccept( ctorInit->get_init(), *visitor );
878	}
879
880	// needs to be callable from outside the resolver, so this is a standalone function
881	void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
882	assert( ctorInit );
883	PassVisitor<Resolver> resolver( indexer );
884	ctorInit->accept( resolver );
885	}
886
887	void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
888	assert( stmtExpr );
889	PassVisitor<Resolver> resolver( indexer );
890	stmtExpr->accept( resolver );
891	stmtExpr->computeResult();
892	// xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
893	}
894
895	void Resolver::previsit( ConstructorInit * ctorInit ) {
896	visit_children = false;
897	// xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
898	maybeAccept( ctorInit->ctor, *visitor );
899	maybeAccept( ctorInit->dtor, *visitor );
900
901	// found a constructor - can get rid of C-style initializer
902	delete ctorInit->init;
903	ctorInit->init = nullptr;
904
905	// intrinsic single parameter constructors and destructors do nothing. Since this was
906	// implicitly generated, there's no way for it to have side effects, so get rid of it
907	// to clean up generated code.
908	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
909	delete ctorInit->ctor;
910	ctorInit->ctor = nullptr;
911	}
912
913	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
914	delete ctorInit->dtor;
915	ctorInit->dtor = nullptr;
916	}
917
918	// xxx - todo -- what about arrays?
919	// if ( dtor == nullptr && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
920	// // can reduce the constructor down to a SingleInit using the
921	// // second argument from the ctor call, since
922	// delete ctorInit->get_ctor();
923	// ctorInit->set_ctor( nullptr );
924
925	// Expression * arg =
926	// ctorInit->set_init( new SingleInit( arg ) );
927	// }
928	}
929	} // namespace ResolvExpr
930
931	// Local Variables: //
932	// tab-width: 4 //
933	// mode: c++ //
934	// compile-command: "make install" //
935	// End: //

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