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source: src/ResolvExpr/Resolver.cc @ 043a5b6

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

Last change on this file since 043a5b6 was 933f32f, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Merge branch 'master' into cleanup-dtors
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	#include "Validate/FindSpecialDecls.h" // for SizeType
46
47	using namespace std;
48
49	namespace ResolvExpr {
50	struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
51	Resolver() {}
52	Resolver( const SymTab::Indexer & other ) {
53	indexer = other;
54	}
55
56	void previsit( FunctionDecl * functionDecl );
57	void postvisit( FunctionDecl * functionDecl );
58	void previsit( ObjectDecl * objectDecll );
59	void previsit( EnumDecl * enumDecl );
60	void previsit( StaticAssertDecl * assertDecl );
61
62	void previsit( ArrayType * at );
63	void previsit( PointerType * at );
64
65	void previsit( ExprStmt * exprStmt );
66	void previsit( AsmExpr * asmExpr );
67	void previsit( AsmStmt * asmStmt );
68	void previsit( IfStmt * ifStmt );
69	void previsit( WhileStmt * whileStmt );
70	void previsit( ForStmt * forStmt );
71	void previsit( SwitchStmt * switchStmt );
72	void previsit( CaseStmt * caseStmt );
73	void previsit( BranchStmt * branchStmt );
74	void previsit( ReturnStmt * returnStmt );
75	void previsit( ThrowStmt * throwStmt );
76	void previsit( CatchStmt * catchStmt );
77	void previsit( WaitForStmt * stmt );
78
79	void previsit( SingleInit * singleInit );
80	void previsit( ListInit * listInit );
81	void previsit( ConstructorInit * ctorInit );
82	private:
83	typedef std::list< Initializer * >::iterator InitIterator;
84
85	template< typename PtrType >
86	void handlePtrType( PtrType * type );
87
88	void fallbackInit( ConstructorInit * ctorInit );
89
90	Type * functionReturn = nullptr;
91	CurrentObject currentObject = nullptr;
92	bool inEnumDecl = false;
93	};
94
95	struct ResolveWithExprs : public WithIndexer, public WithGuards, public WithVisitorRef<ResolveWithExprs>, public WithShortCircuiting, public WithStmtsToAdd {
96	void previsit( FunctionDecl * );
97	void previsit( WithStmt * );
98
99	void resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts );
100	};
101
102	void resolve( std::list< Declaration * > translationUnit ) {
103	PassVisitor<Resolver> resolver;
104	acceptAll( translationUnit, resolver );
105	}
106
107	void resolveDecl( Declaration * decl, const SymTab::Indexer & indexer ) {
108	PassVisitor<Resolver> resolver( indexer );
109	maybeAccept( decl, resolver );
110	}
111
112	namespace {
113	struct DeleteFinder : public WithShortCircuiting {
114	DeletedExpr * delExpr = nullptr;
115	void previsit( DeletedExpr * expr ) {
116	if ( delExpr ) visit_children = false;
117	else delExpr = expr;
118	}
119
120	void previsit( Expression * ) {
121	if ( delExpr ) visit_children = false;
122	}
123	};
124	}
125
126	DeletedExpr * findDeletedExpr( Expression * expr ) {
127	PassVisitor<DeleteFinder> finder;
128	expr->accept( finder );
129	return finder.pass.delExpr;
130	}
131
132	namespace {
133	struct StripCasts {
134	Expression * postmutate( CastExpr * castExpr ) {
135	if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
136	// generated cast is to the same type as its argument, so it's unnecessary -- remove it
137	Expression * expr = castExpr->arg;
138	castExpr->arg = nullptr;
139	std::swap( expr->env, castExpr->env );
140	return expr;
141	}
142	return castExpr;
143	}
144
145	static void strip( Expression *& expr ) {
146	PassVisitor<StripCasts> stripper;
147	expr = expr->acceptMutator( stripper );
148	}
149	};
150
151	void finishExpr( Expression & expr, const TypeEnvironment & env, TypeSubstitution oldenv = nullptr ) {
152	expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
153	env.makeSubstitution( *expr->env );
154	StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
155	}
156
157	void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
158	if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
159	if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
160	// cast is to the same type as its argument, so it's unnecessary -- remove it
161	expr = castExpr->arg;
162	castExpr->arg = nullptr;
163	std::swap( expr->env, castExpr->env );
164	delete castExpr;
165	}
166	}
167	}
168	} // namespace
169
170	namespace {
171	void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{} ) {
172	assertf( untyped, "expected a non-null expression." );
173
174	// xxx - this isn't thread-safe, but should work until we parallelize the resolver
175	static unsigned recursion_level = 0;
176
177	++recursion_level;
178	TypeEnvironment env;
179	AlternativeFinder finder( indexer, env );
180	finder.find( untyped, recursion_level == 1 ? mode.atTopLevel() : mode );
181	--recursion_level;
182
183	#if 0
184	if ( finder.get_alternatives().size() != 1 ) {
185	std::cerr << "untyped expr is ";
186	untyped->print( std::cerr );
187	std::cerr << std::endl << "alternatives are:";
188	for ( const Alternative & alt : finder.get_alternatives() ) {
189	alt.print( std::cerr );
190	} // for
191	} // if
192	#endif
193
194	// produce filtered list of alternatives
195	AltList candidates;
196	for ( Alternative & alt : finder.get_alternatives() ) {
197	if ( pred( alt ) ) {
198	candidates.push_back( std::move( alt ) );
199	}
200	}
201
202	// produce invalid error if no candidates
203	if ( candidates.empty() ) {
204	SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
205	}
206
207	// search for cheapest candidate
208	AltList winners;
209	bool seen_undeleted = false;
210	for ( unsigned i = 0; i < candidates.size(); ++i ) {
211	int c = winners.empty() ? -1 : candidates[i].cost.compare( winners.front().cost );
212
213	if ( c > 0 ) continue; // skip more expensive than winner
214
215	if ( c < 0 ) {
216	// reset on new cheapest
217	seen_undeleted = ! findDeletedExpr( candidates[i].expr );
218	winners.clear();
219	} else /* if ( c == 0 ) */ {
220	if ( findDeletedExpr( candidates[i].expr ) ) {
221	// skip deleted expression if already seen one equivalent-cost not
222	if ( seen_undeleted ) continue;
223	} else if ( ! seen_undeleted ) {
224	// replace list of equivalent-cost deleted expressions with one non-deleted
225	winners.clear();
226	seen_undeleted = true;
227	}
228	}
229
230	winners.emplace_back( std::move( candidates[i] ) );
231	}
232
233	// promote alternative.cvtCost to .cost
234	// xxx - I don't know why this is done, but I'm keeping the behaviour from findMinCost
235	for ( Alternative& winner : winners ) {
236	winner.cost = winner.cvtCost;
237	}
238
239	// produce ambiguous errors, if applicable
240	if ( winners.size() != 1 ) {
241	std::ostringstream stream;
242	stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
243	untyped->print( stream );
244	stream << " Alternatives are:\n";
245	printAlts( winners, stream, 1 );
246	SemanticError( untyped->location, stream.str() );
247	}
248
249	// single selected choice
250	Alternative& choice = winners.front();
251
252	// fail on only expression deleted
253	if ( ! seen_undeleted ) {
254	SemanticError( untyped->location, choice.expr, "Unique best alternative includes deleted identifier in " );
255	}
256
257	// xxx - check for ambiguous expressions
258
259	// output selected choice
260	alt = std::move( choice );
261	}
262
263	/// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
264	void findKindExpression(Expression *& untyped, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{}) {
265	if ( ! untyped ) return;
266	Alternative choice;
267	findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, mode );
268	finishExpr( choice.expr, choice.env, untyped->env );
269	delete untyped;
270	untyped = choice.expr;
271	choice.expr = nullptr;
272	}
273
274	bool standardAlternativeFilter( const Alternative & ) {
275	// currently don't need to filter, under normal circumstances.
276	// in the future, this may be useful for removing deleted expressions
277	return true;
278	}
279	} // namespace
280
281	// used in resolveTypeof
282	Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer ) {
283	TypeEnvironment env;
284	return resolveInVoidContext( expr, indexer, env );
285	}
286
287	Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer, TypeEnvironment & env ) {
288	// it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
289	// interpretations, an exception has already been thrown.
290	assertf( expr, "expected a non-null expression." );
291
292	CastExpr * untyped = new CastExpr( expr ); // cast to void
293	untyped->location = expr->location;
294
295	// set up and resolve expression cast to void
296	Alternative choice;
297	findUnfinishedKindExpression( untyped, choice, indexer, "", standardAlternativeFilter, ResolvMode::withAdjustment() );
298	CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
299	assert( castExpr );
300	env = std::move( choice.env );
301
302	// clean up resolved expression
303	Expression * ret = castExpr->arg;
304	castExpr->arg = nullptr;
305
306	// unlink the arg so that it isn't deleted twice at the end of the program
307	untyped->arg = nullptr;
308	return ret;
309	}
310
311	void findVoidExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
312	resetTyVarRenaming();
313	TypeEnvironment env;
314	Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
315	finishExpr( newExpr, env, untyped->env );
316	delete untyped;
317	untyped = newExpr;
318	}
319
320	void findSingleExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
321	findKindExpression( untyped, indexer, "", standardAlternativeFilter );
322	}
323
324	void findSingleExpression( Expression & untyped, Type type, const SymTab::Indexer & indexer ) {
325	assert( untyped && type );
326	// transfer location to generated cast for error purposes
327	CodeLocation location = untyped->location;
328	untyped = new CastExpr( untyped, type );
329	untyped->location = location;
330	findSingleExpression( untyped, indexer );
331	removeExtraneousCast( untyped, indexer );
332	}
333
334	namespace {
335	bool isIntegralType( const Alternative & alt ) {
336	Type * type = alt.expr->result;
337	if ( dynamic_cast< EnumInstType * >( type ) ) {
338	return true;
339	} else if ( BasicType * bt = dynamic_cast< BasicType * >( type ) ) {
340	return bt->isInteger();
341	} else if ( dynamic_cast< ZeroType* >( type ) != nullptr \|\| dynamic_cast< OneType* >( type ) != nullptr ) {
342	return true;
343	} else {
344	return false;
345	} // if
346	}
347
348	void findIntegralExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
349	findKindExpression( untyped, indexer, "condition", isIntegralType );
350	}
351	}
352
353
354	bool isStructOrUnion( const Alternative & alt ) {
355	Type * t = alt.expr->result->stripReferences();
356	return dynamic_cast< StructInstType * >( t ) \|\| dynamic_cast< UnionInstType * >( t );
357	}
358
359	void resolveWithExprs( std::list< Declaration * > & translationUnit ) {
360	PassVisitor<ResolveWithExprs> resolver;
361	acceptAll( translationUnit, resolver );
362	}
363
364	void ResolveWithExprs::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
365	for ( Expression *& expr : withExprs ) {
366	// only struct- and union-typed expressions are viable candidates
367	findKindExpression( expr, indexer, "with statement", isStructOrUnion );
368
369	// if with expression might be impure, create a temporary so that it is evaluated once
370	if ( Tuples::maybeImpure( expr ) ) {
371	static UniqueName tmpNamer( "_with_tmp_" );
372	ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
373	expr = new VariableExpr( tmp );
374	newStmts.push_back( new DeclStmt( tmp ) );
375	if ( InitTweak::isConstructable( tmp->type ) ) {
376	// generate ctor/dtor and resolve them
377	tmp->init = InitTweak::genCtorInit( tmp );
378	tmp->accept( *visitor );
379	}
380	}
381	}
382	}
383
384	void ResolveWithExprs::previsit( WithStmt * withStmt ) {
385	resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
386	}
387
388	void ResolveWithExprs::previsit( FunctionDecl * functionDecl ) {
389	{
390	// resolve with-exprs with parameters in scope and add any newly generated declarations to the
391	// front of the function body.
392	auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
393	indexer.addFunctionType( functionDecl->type );
394	std::list< Statement * > newStmts;
395	resolveWithExprs( functionDecl->withExprs, newStmts );
396	if ( functionDecl->statements ) {
397	functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
398	} else {
399	assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
400	}
401	}
402	}
403
404	void Resolver::previsit( ObjectDecl * objectDecl ) {
405	// To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that
406	// class-variable initContext is changed multiple time because the LHS is analysed twice.
407	// The second analysis changes initContext because of a function type can contain object
408	// declarations in the return and parameter types. So each value of initContext is
409	// retained, so the type on the first analysis is preserved and used for selecting the RHS.
410	GuardValue( currentObject );
411	currentObject = CurrentObject( objectDecl->get_type() );
412	if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
413	// enumerator initializers should not use the enum type to initialize, since
414	// the enum type is still incomplete at this point. Use signed int instead.
415	currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
416	}
417	}
418
419	template< typename PtrType >
420	void Resolver::handlePtrType( PtrType * type ) {
421	if ( type->get_dimension() ) {
422	findSingleExpression( type->dimension, Validate::SizeType->clone(), indexer );
423	}
424	}
425
426	void Resolver::previsit( ArrayType * at ) {
427	handlePtrType( at );
428	}
429
430	void Resolver::previsit( PointerType * pt ) {
431	handlePtrType( pt );
432	}
433
434	void Resolver::previsit( FunctionDecl * functionDecl ) {
435	#if 0
436	std::cerr << "resolver visiting functiondecl ";
437	functionDecl->print( std::cerr );
438	std::cerr << std::endl;
439	#endif
440	GuardValue( functionReturn );
441	functionReturn = ResolvExpr::extractResultType( functionDecl->type );
442	}
443
444	void Resolver::postvisit( FunctionDecl * functionDecl ) {
445	// default value expressions have an environment which shouldn't be there and trips up
446	// later passes.
447	// xxx - it might be necessary to somehow keep the information from this environment, but I
448	// can't currently see how it's useful.
449	for ( Declaration * d : functionDecl->type->parameters ) {
450	if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
451	if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
452	delete init->value->env;
453	init->value->env = nullptr;
454	}
455	}
456	}
457	}
458
459	void Resolver::previsit( EnumDecl * ) {
460	// in case we decide to allow nested enums
461	GuardValue( inEnumDecl );
462	inEnumDecl = true;
463	}
464
465	void Resolver::previsit( StaticAssertDecl * assertDecl ) {
466	findIntegralExpression( assertDecl->condition, indexer );
467	}
468
469	void Resolver::previsit( ExprStmt * exprStmt ) {
470	visit_children = false;
471	assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
472	findVoidExpression( exprStmt->expr, indexer );
473	}
474
475	void Resolver::previsit( AsmExpr * asmExpr ) {
476	visit_children = false;
477	findVoidExpression( asmExpr->operand, indexer );
478	if ( asmExpr->get_inout() ) {
479	findVoidExpression( asmExpr->inout, indexer );
480	} // if
481	}
482
483	void Resolver::previsit( AsmStmt * asmStmt ) {
484	visit_children = false;
485	acceptAll( asmStmt->get_input(), *visitor );
486	acceptAll( asmStmt->get_output(), *visitor );
487	}
488
489	void Resolver::previsit( IfStmt * ifStmt ) {
490	findIntegralExpression( ifStmt->condition, indexer );
491	}
492
493	void Resolver::previsit( WhileStmt * whileStmt ) {
494	findIntegralExpression( whileStmt->condition, indexer );
495	}
496
497	void Resolver::previsit( ForStmt * forStmt ) {
498	if ( forStmt->condition ) {
499	findIntegralExpression( forStmt->condition, indexer );
500	} // if
501
502	if ( forStmt->increment ) {
503	findVoidExpression( forStmt->increment, indexer );
504	} // if
505	}
506
507	void Resolver::previsit( SwitchStmt * switchStmt ) {
508	GuardValue( currentObject );
509	findIntegralExpression( switchStmt->condition, indexer );
510
511	currentObject = CurrentObject( switchStmt->condition->result );
512	}
513
514	void Resolver::previsit( CaseStmt * caseStmt ) {
515	if ( caseStmt->condition ) {
516	std::list< InitAlternative > initAlts = currentObject.getOptions();
517	assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
518	// must remove cast from case statement because RangeExpr cannot be cast.
519	Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
520	findSingleExpression( newExpr, indexer );
521	// case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
522	// Ideally we would perform the conversion internally here.
523	if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
524	newExpr = castExpr->arg;
525	castExpr->arg = nullptr;
526	std::swap( newExpr->env, castExpr->env );
527	delete castExpr;
528	}
529	caseStmt->condition = newExpr;
530	}
531	}
532
533	void Resolver::previsit( BranchStmt * branchStmt ) {
534	visit_children = false;
535	// must resolve the argument for a computed goto
536	if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
537	if ( branchStmt->computedTarget ) {
538	// computed goto argument is void *
539	findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
540	} // if
541	} // if
542	}
543
544	void Resolver::previsit( ReturnStmt * returnStmt ) {
545	visit_children = false;
546	if ( returnStmt->expr ) {
547	findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
548	} // if
549	}
550
551	void Resolver::previsit( ThrowStmt * throwStmt ) {
552	visit_children = false;
553	// TODO: Replace *exception type with &exception type.
554	if ( throwStmt->get_expr() ) {
555	StructDecl * exception_decl =
556	indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
557	assert( exception_decl );
558	Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
559	findSingleExpression( throwStmt->expr, exceptType, indexer );
560	}
561	}
562
563	void Resolver::previsit( CatchStmt * catchStmt ) {
564	if ( catchStmt->cond ) {
565	findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
566	}
567	}
568
569	template< typename iterator_t >
570	inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
571	while( it != end && !(*it)->get_type()->get_mutex() ) {
572	it++;
573	}
574
575	return it != end;
576	}
577
578	void Resolver::previsit( WaitForStmt * stmt ) {
579	visit_children = false;
580
581	// Resolve all clauses first
582	for( auto& clause : stmt->clauses ) {
583
584	TypeEnvironment env;
585	AlternativeFinder funcFinder( indexer, env );
586
587	// Find all alternatives for a function in canonical form
588	funcFinder.findWithAdjustment( clause.target.function );
589
590	if ( funcFinder.get_alternatives().empty() ) {
591	stringstream ss;
592	ss << "Use of undeclared indentifier '";
593	ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
594	ss << "' in call to waitfor";
595	SemanticError( stmt->location, ss.str() );
596	}
597
598	if(clause.target.arguments.empty()) {
599	SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
600	}
601
602	// Find all alternatives for all arguments in canonical form
603	std::vector< AlternativeFinder > argAlternatives;
604	funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
605
606	// List all combinations of arguments
607	std::vector< AltList > possibilities;
608	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
609
610	AltList func_candidates;
611	std::vector< AltList > args_candidates;
612
613	// For every possible function :
614	// try matching the arguments to the parameters
615	// not the other way around because we have more arguments than parameters
616	SemanticErrorException errors;
617	for ( Alternative & func : funcFinder.get_alternatives() ) {
618	try {
619	PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
620	if( !pointer ) {
621	SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
622	}
623
624	FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
625	if( !function ) {
626	SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
627	}
628
629
630	{
631	auto param = function->parameters.begin();
632	auto param_end = function->parameters.end();
633
634	if( !advance_to_mutex( param, param_end ) ) {
635	SemanticError(function, "candidate function not viable: no mutex parameters\n");
636	}
637	}
638
639	Alternative newFunc( func );
640	// Strip reference from function
641	referenceToRvalueConversion( newFunc.expr, newFunc.cost );
642
643	// For all the set of arguments we have try to match it with the parameter of the current function alternative
644	for ( auto & argsList : possibilities ) {
645
646	try {
647	// Declare data structures need for resolution
648	OpenVarSet openVars;
649	AssertionSet resultNeed, resultHave;
650	TypeEnvironment resultEnv( func.env );
651	makeUnifiableVars( function, openVars, resultNeed );
652	// add all type variables as open variables now so that those not used in the parameter
653	// list are still considered open.
654	resultEnv.add( function->forall );
655
656	// Load type variables from arguemnts into one shared space
657	simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
658
659	// Make sure we don't widen any existing bindings
660	resultEnv.forbidWidening();
661
662	// Find any unbound type variables
663	resultEnv.extractOpenVars( openVars );
664
665	auto param = function->parameters.begin();
666	auto param_end = function->parameters.end();
667
668	int n_mutex_param = 0;
669
670	// For every arguments of its set, check if it matches one of the parameter
671	// The order is important
672	for( auto & arg : argsList ) {
673
674	// Ignore non-mutex arguments
675	if( !advance_to_mutex( param, param_end ) ) {
676	// We ran out of parameters but still have arguments
677	// this function doesn't match
678	SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_param, "\n" ));
679	}
680
681	n_mutex_param++;
682
683	// Check if the argument matches the parameter type in the current scope
684	if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
685	// Type doesn't match
686	stringstream ss;
687	ss << "candidate function not viable: no known convertion from '";
688	(*param)->get_type()->print( ss );
689	ss << "' to '";
690	arg.expr->get_result()->print( ss );
691	ss << "' with env '";
692	resultEnv.print(ss);
693	ss << "'\n";
694	SemanticError( function, ss.str() );
695	}
696
697	param++;
698	}
699
700	// All arguments match !
701
702	// Check if parameters are missing
703	if( advance_to_mutex( param, param_end ) ) {
704	do {
705	n_mutex_param++;
706	param++;
707	} while( advance_to_mutex( param, param_end ) );
708
709	// We ran out of arguments but still have parameters left
710	// this function doesn't match
711	SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_param, "\n" ));
712	}
713
714	// All parameters match !
715
716	// Finish the expressions to tie in the proper environments
717	finishExpr( newFunc.expr, resultEnv );
718	for( Alternative & alt : argsList ) {
719	finishExpr( alt.expr, resultEnv );
720	}
721
722	// This is a match store it and save it for later
723	func_candidates.push_back( newFunc );
724	args_candidates.push_back( argsList );
725
726	}
727	catch( SemanticErrorException & e ) {
728	errors.append( e );
729	}
730	}
731	}
732	catch( SemanticErrorException & e ) {
733	errors.append( e );
734	}
735	}
736
737	// Make sure we got the right number of arguments
738	if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
739	if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
740	if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
741	if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
742	// TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
743
744	// Swap the results from the alternative with the unresolved values.
745	// Alternatives will handle deletion on destruction
746	std::swap( clause.target.function, func_candidates.front().expr );
747	for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
748	std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
749	}
750
751	// Resolve the conditions as if it were an IfStmt
752	// Resolve the statments normally
753	findSingleExpression( clause.condition, this->indexer );
754	clause.statement->accept( *visitor );
755	}
756
757
758	if( stmt->timeout.statement ) {
759	// Resolve the timeout as an size_t for now
760	// Resolve the conditions as if it were an IfStmt
761	// Resolve the statments normally
762	findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
763	findSingleExpression( stmt->timeout.condition, this->indexer );
764	stmt->timeout.statement->accept( *visitor );
765	}
766
767	if( stmt->orelse.statement ) {
768	// Resolve the conditions as if it were an IfStmt
769	// Resolve the statments normally
770	findSingleExpression( stmt->orelse.condition, this->indexer );
771	stmt->orelse.statement->accept( *visitor );
772	}
773	}
774
775	template< typename T >
776	bool isCharType( T t ) {
777	if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
778	return bt->get_kind() == BasicType::Char \|\| bt->get_kind() == BasicType::SignedChar \|\|
779	bt->get_kind() == BasicType::UnsignedChar;
780	}
781	return false;
782	}
783
784	void Resolver::previsit( SingleInit * singleInit ) {
785	visit_children = false;
786	// resolve initialization using the possibilities as determined by the currentObject cursor
787	Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
788	findSingleExpression( newExpr, indexer );
789	InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
790
791	// move cursor to the object that is actually initialized
792	currentObject.setNext( initExpr->get_designation() );
793
794	// discard InitExpr wrapper and retain relevant pieces
795	newExpr = initExpr->expr;
796	initExpr->expr = nullptr;
797	std::swap( initExpr->env, newExpr->env );
798	// InitExpr may have inferParams in the case where the expression specializes a function
799	// pointer, and newExpr may already have inferParams of its own, so a simple swap is not
800	// sufficient.
801	newExpr->spliceInferParams( initExpr );
802	delete initExpr;
803
804	// get the actual object's type (may not exactly match what comes back from the resolver
805	// due to conversions)
806	Type * initContext = currentObject.getCurrentType();
807
808	removeExtraneousCast( newExpr, indexer );
809
810	// check if actual object's type is char[]
811	if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
812	if ( isCharType( at->get_base() ) ) {
813	// check if the resolved type is char *
814	if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
815	if ( isCharType( pt->get_base() ) ) {
816	if ( CastExpr * ce = dynamic_cast< CastExpr * >( newExpr ) ) {
817	// strip cast if we're initializing a char[] with a char *,
818	// e.g. char x[] = "hello";
819	newExpr = ce->get_arg();
820	ce->set_arg( nullptr );
821	std::swap( ce->env, newExpr->env );
822	delete ce;
823	}
824	}
825	}
826	}
827	}
828
829	// set initializer expr to resolved express
830	singleInit->value = newExpr;
831
832	// move cursor to next object in preparation for next initializer
833	currentObject.increment();
834	}
835
836	void Resolver::previsit( ListInit * listInit ) {
837	visit_children = false;
838	// move cursor into brace-enclosed initializer-list
839	currentObject.enterListInit();
840	// xxx - fix this so that the list isn't copied, iterator should be used to change current
841	// element
842	std::list<Designation *> newDesignations;
843	for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
844	// iterate designations and initializers in pairs, moving the cursor to the current
845	// designated object and resolving the initializer against that object.
846	Designation * des = std::get<0>(p);
847	Initializer * init = std::get<1>(p);
848	newDesignations.push_back( currentObject.findNext( des ) );
849	init->accept( *visitor );
850	}
851	// set the set of 'resolved' designations and leave the brace-enclosed initializer-list
852	listInit->get_designations() = newDesignations; // xxx - memory management
853	currentObject.exitListInit();
854
855	// xxx - this part has not be folded into CurrentObject yet
856	// } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
857	// Type * base = tt->get_baseType()->get_base();
858	// if ( base ) {
859	// // know the implementation type, so try using that as the initContext
860	// ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
861	// currentObject = &tmpObj;
862	// visit( listInit );
863	// } else {
864	// // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
865	// Parent::visit( listInit );
866	// }
867	// } else {
868	}
869
870	// ConstructorInit - fall back on C-style initializer
871	void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
872	// could not find valid constructor, or found an intrinsic constructor
873	// fall back on C-style initializer
874	delete ctorInit->get_ctor();
875	ctorInit->set_ctor( nullptr );
876	delete ctorInit->get_dtor();
877	ctorInit->set_dtor( nullptr );
878	maybeAccept( ctorInit->get_init(), *visitor );
879	}
880
881	// needs to be callable from outside the resolver, so this is a standalone function
882	void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
883	assert( ctorInit );
884	PassVisitor<Resolver> resolver( indexer );
885	ctorInit->accept( resolver );
886	}
887
888	void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
889	assert( stmtExpr );
890	PassVisitor<Resolver> resolver( indexer );
891	stmtExpr->accept( resolver );
892	stmtExpr->computeResult();
893	// xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
894	}
895
896	void Resolver::previsit( ConstructorInit * ctorInit ) {
897	visit_children = false;
898	// xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
899	maybeAccept( ctorInit->ctor, *visitor );
900	maybeAccept( ctorInit->dtor, *visitor );
901
902	// found a constructor - can get rid of C-style initializer
903	delete ctorInit->init;
904	ctorInit->init = nullptr;
905
906	// intrinsic single parameter constructors and destructors do nothing. Since this was
907	// implicitly generated, there's no way for it to have side effects, so get rid of it
908	// to clean up generated code.
909	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
910	delete ctorInit->ctor;
911	ctorInit->ctor = nullptr;
912	}
913
914	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
915	delete ctorInit->dtor;
916	ctorInit->dtor = nullptr;
917	}
918
919	// xxx - todo -- what about arrays?
920	// if ( dtor == nullptr && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
921	// // can reduce the constructor down to a SingleInit using the
922	// // second argument from the ctor call, since
923	// delete ctorInit->get_ctor();
924	// ctorInit->set_ctor( nullptr );
925
926	// Expression * arg =
927	// ctorInit->set_init( new SingleInit( arg ) );
928	// }
929	}
930	} // namespace ResolvExpr
931
932	// Local Variables: //
933	// tab-width: 4 //
934	// mode: c++ //
935	// compile-command: "make install" //
936	// End: //

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