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source: src/ResolvExpr/Resolver.cc @ 6d2f993

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Last change on this file since 6d2f993 was 3ca540f, checked in by Rob Schluntz <rschlunt@…>, 6 years ago
Merge branch 'master' into with-statement
Property mode set to `100644`
File size: 28.0 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 : Andrew Beach
12	// Last Modified On : Tus Aug 8 16:06:00 2017
13	// Update Count : 212
14	//
15
16	#include <stddef.h> // for NULL
17	#include <cassert> // for strict_dynamic_cast, assert
18	#include <memory> // for allocator, allocator_traits<...
19	#include <tuple> // for get
20	#include <vector>
21
22	#include "Alternative.h" // for Alternative, AltList
23	#include "AlternativeFinder.h" // for AlternativeFinder, resolveIn...
24	#include "Common/PassVisitor.h" // for PassVisitor
25	#include "Common/SemanticError.h" // for SemanticError
26	#include "Common/utility.h" // for ValueGuard, group_iterate
27	#include "CurrentObject.h" // for CurrentObject
28	#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
29	#include "RenameVars.h" // for RenameVars, global_renamer
30	#include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment
31	#include "ResolveTypeof.h" // for resolveTypeof
32	#include "Resolver.h"
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 "typeops.h" // for extractResultType
43	#include "Unify.h" // for unify
44
45	using namespace std;
46
47	namespace ResolvExpr {
48	struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting {
49	Resolver() {}
50	Resolver( const SymTab::Indexer & other ) {
51	indexer = other;
52	}
53
54	void previsit( FunctionDecl *functionDecl );
55	void postvisit( FunctionDecl *functionDecl );
56	void previsit( ObjectDecl *objectDecll );
57	void previsit( TypeDecl *typeDecl );
58	void previsit( EnumDecl * enumDecl );
59
60	void previsit( ArrayType * at );
61	void previsit( PointerType * at );
62
63	void previsit( ExprStmt *exprStmt );
64	void previsit( AsmExpr *asmExpr );
65	void previsit( AsmStmt *asmStmt );
66	void previsit( IfStmt *ifStmt );
67	void previsit( WhileStmt *whileStmt );
68	void previsit( ForStmt *forStmt );
69	void previsit( SwitchStmt *switchStmt );
70	void previsit( CaseStmt *caseStmt );
71	void previsit( BranchStmt *branchStmt );
72	void previsit( ReturnStmt *returnStmt );
73	void previsit( ThrowStmt *throwStmt );
74	void previsit( CatchStmt *catchStmt );
75	void previsit( WaitForStmt * stmt );
76	void previsit( WithStmt * withStmt );
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 resolveAggrInit( ReferenceToType *, InitIterator &, InitIterator & );
88	void resolveSingleAggrInit( Declaration *, InitIterator &, InitIterator &, TypeSubstitution sub );
89	void fallbackInit( ConstructorInit * ctorInit );
90
91	Type * functionReturn = nullptr;
92	CurrentObject currentObject = nullptr;
93	bool inEnumDecl = false;
94	};
95
96	void resolve( std::list< Declaration * > translationUnit ) {
97	PassVisitor<Resolver> resolver;
98	acceptAll( translationUnit, resolver );
99	}
100
101	void resolveDecl( Declaration * decl, const SymTab::Indexer &indexer ) {
102	PassVisitor<Resolver> resolver( indexer );
103	maybeAccept( decl, resolver );
104	}
105
106	// used in resolveTypeof
107	Expression resolveInVoidContext( Expression expr, const SymTab::Indexer &indexer ) {
108	TypeEnvironment env;
109	return resolveInVoidContext( expr, indexer, env );
110	}
111
112	namespace {
113	void finishExpr( Expression expr, const TypeEnvironment &env, TypeSubstitution oldenv = nullptr ) {
114	expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
115	env.makeSubstitution( *expr->get_env() );
116	}
117
118	void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
119	if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
120	if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
121	// cast is to the same type as its argument, so it's unnecessary -- remove it
122	expr = castExpr->arg;
123	castExpr->arg = nullptr;
124	std::swap( expr->env, castExpr->env );
125	delete castExpr;
126	}
127	}
128	}
129	} // namespace
130
131	void findVoidExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
132	global_renamer.reset();
133	TypeEnvironment env;
134	Expression *newExpr = resolveInVoidContext( untyped, indexer, env );
135	finishExpr( newExpr, env, untyped->env );
136	delete untyped;
137	untyped = newExpr;
138	}
139
140	void findSingleExpression( Expression *&untyped, const SymTab::Indexer &indexer ) {
141	if ( ! untyped ) return;
142	TypeEnvironment env;
143	AlternativeFinder finder( indexer, env );
144	finder.find( untyped );
145	#if 0
146	if ( finder.get_alternatives().size() != 1 ) {
147	std::cerr << "untyped expr is ";
148	untyped->print( std::cerr );
149	std::cerr << std::endl << "alternatives are:";
150	for ( const Alternative & alt : finder.get_alternatives() ) {
151	alt.print( std::cerr );
152	} // for
153	} // if
154	#endif
155	assertf( finder.get_alternatives().size() == 1, "findSingleExpression: must have exactly one alternative at the end." );
156	Alternative &choice = finder.get_alternatives().front();
157	Expression *newExpr = choice.expr->clone();
158	finishExpr( newExpr, choice.env, untyped->env );
159	delete untyped;
160	untyped = newExpr;
161	}
162
163	void findSingleExpression( Expression & untyped, Type type, const SymTab::Indexer & indexer ) {
164	assert( untyped && type );
165	untyped = new CastExpr( untyped, type );
166	findSingleExpression( untyped, indexer );
167	removeExtraneousCast( untyped, indexer );
168	}
169
170	namespace {
171	bool isIntegralType( Type *type ) {
172	if ( dynamic_cast< EnumInstType * >( type ) ) {
173	return true;
174	} else if ( BasicType bt = dynamic_cast< BasicType >( type ) ) {
175	return bt->isInteger();
176	} else if ( dynamic_cast< ZeroType* >( type ) != nullptr \|\| dynamic_cast< OneType* >( type ) != nullptr ) {
177	return true;
178	} else {
179	return false;
180	} // if
181	}
182
183	void findIntegralExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
184	TypeEnvironment env;
185	AlternativeFinder finder( indexer, env );
186	finder.find( untyped );
187	#if 0
188	if ( finder.get_alternatives().size() != 1 ) {
189	std::cout << "untyped expr is ";
190	untyped->print( std::cout );
191	std::cout << std::endl << "alternatives are:";
192	for ( std::list< Alternative >::const_iterator i = finder.get_alternatives().begin(); i != finder.get_alternatives().end(); ++i ) {
193	i->print( std::cout );
194	} // for
195	} // if
196	#endif
197	Expression *newExpr = 0;
198	const TypeEnvironment *newEnv = 0;
199	for ( AltList::const_iterator i = finder.get_alternatives().begin(); i != finder.get_alternatives().end(); ++i ) {
200	if ( i->expr->get_result()->size() == 1 && isIntegralType( i->expr->get_result() ) ) {
201	if ( newExpr ) {
202	throw SemanticError( "Too many interpretations for case control expression", untyped );
203	} else {
204	newExpr = i->expr->clone();
205	newEnv = &i->env;
206	} // if
207	} // if
208	} // for
209	if ( ! newExpr ) {
210	throw SemanticError( "No interpretations for case control expression", untyped );
211	} // if
212	finishExpr( newExpr, *newEnv, untyped->env );
213	delete untyped;
214	untyped = newExpr;
215	}
216
217	}
218
219	void Resolver::previsit( ObjectDecl *objectDecl ) {
220	Type *new_type = resolveTypeof( objectDecl->get_type(), indexer );
221	objectDecl->set_type( new_type );
222	// To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
223	// initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
224	// initContext because of a function type can contain object declarations in the return and parameter types. So
225	// each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
226	// the RHS.
227	GuardValue( currentObject );
228	currentObject = CurrentObject( objectDecl->get_type() );
229	if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
230	// enumerator initializers should not use the enum type to initialize, since
231	// the enum type is still incomplete at this point. Use signed int instead.
232	currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
233	}
234	}
235
236	template< typename PtrType >
237	void Resolver::handlePtrType( PtrType * type ) {
238	if ( type->get_dimension() ) {
239	findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
240	}
241	}
242
243	void Resolver::previsit( ArrayType * at ) {
244	handlePtrType( at );
245	}
246
247	void Resolver::previsit( PointerType * pt ) {
248	handlePtrType( pt );
249	}
250
251	void Resolver::previsit( TypeDecl *typeDecl ) {
252	if ( typeDecl->get_base() ) {
253	Type *new_type = resolveTypeof( typeDecl->get_base(), indexer );
254	typeDecl->set_base( new_type );
255	} // if
256	}
257
258	void Resolver::previsit( FunctionDecl *functionDecl ) {
259	#if 0
260	std::cerr << "resolver visiting functiondecl ";
261	functionDecl->print( std::cerr );
262	std::cerr << std::endl;
263	#endif
264	Type *new_type = resolveTypeof( functionDecl->get_type(), indexer );
265	functionDecl->set_type( new_type );
266	GuardValue( functionReturn );
267	functionReturn = ResolvExpr::extractResultType( functionDecl->get_functionType() );
268	}
269
270	void Resolver::postvisit( FunctionDecl *functionDecl ) {
271	// default value expressions have an environment which shouldn't be there and trips up later passes.
272	// xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
273	// see how it's useful.
274	for ( Declaration * d : functionDecl->get_functionType()->get_parameters() ) {
275	if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
276	if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->get_init() ) ) {
277	delete init->get_value()->get_env();
278	init->get_value()->set_env( nullptr );
279	}
280	}
281	}
282	}
283
284	void Resolver::previsit( EnumDecl * ) {
285	// in case we decide to allow nested enums
286	GuardValue( inEnumDecl );
287	inEnumDecl = true;
288	}
289
290	void Resolver::previsit( ExprStmt *exprStmt ) {
291	visit_children = false;
292	assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
293	findVoidExpression( exprStmt->expr, indexer );
294	}
295
296	void Resolver::previsit( AsmExpr *asmExpr ) {
297	visit_children = false;
298	findVoidExpression( asmExpr->operand, indexer );
299	if ( asmExpr->get_inout() ) {
300	findVoidExpression( asmExpr->inout, indexer );
301	} // if
302	}
303
304	void Resolver::previsit( AsmStmt *asmStmt ) {
305	visit_children = false;
306	acceptAll( asmStmt->get_input(), *visitor );
307	acceptAll( asmStmt->get_output(), *visitor );
308	}
309
310	void Resolver::previsit( IfStmt *ifStmt ) {
311	findSingleExpression( ifStmt->condition, indexer );
312	}
313
314	void Resolver::previsit( WhileStmt *whileStmt ) {
315	findSingleExpression( whileStmt->condition, indexer );
316	}
317
318	void Resolver::previsit( ForStmt *forStmt ) {
319	if ( forStmt->condition ) {
320	findSingleExpression( forStmt->condition, indexer );
321	} // if
322
323	if ( forStmt->increment ) {
324	findVoidExpression( forStmt->increment, indexer );
325	} // if
326	}
327
328	void Resolver::previsit( SwitchStmt *switchStmt ) {
329	GuardValue( currentObject );
330	findIntegralExpression( switchStmt->condition, indexer );
331
332	currentObject = CurrentObject( switchStmt->condition->result );
333	}
334
335	void Resolver::previsit( CaseStmt *caseStmt ) {
336	if ( caseStmt->get_condition() ) {
337	std::list< InitAlternative > initAlts = currentObject.getOptions();
338	assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
339	// must remove cast from case statement because RangeExpr cannot be cast.
340	Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
341	findSingleExpression( newExpr, indexer );
342	CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( newExpr );
343	caseStmt->condition = castExpr->arg;
344	castExpr->arg = nullptr;
345	delete castExpr;
346	}
347	}
348
349	void Resolver::previsit( BranchStmt *branchStmt ) {
350	visit_children = false;
351	// must resolve the argument for a computed goto
352	if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
353	if ( branchStmt->computedTarget ) {
354	// computed goto argument is void *
355	findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
356	} // if
357	} // if
358	}
359
360	void Resolver::previsit( ReturnStmt *returnStmt ) {
361	visit_children = false;
362	if ( returnStmt->expr ) {
363	findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
364	} // if
365	}
366
367	void Resolver::previsit( ThrowStmt *throwStmt ) {
368	visit_children = false;
369	// TODO: Replace *exception type with &exception type.
370	if ( throwStmt->get_expr() ) {
371	StructDecl * exception_decl =
372	indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
373	assert( exception_decl );
374	Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
375	findSingleExpression( throwStmt->expr, exceptType, indexer );
376	}
377	}
378
379	void Resolver::previsit( CatchStmt *catchStmt ) {
380	if ( catchStmt->cond ) {
381	findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
382	}
383	}
384
385	template< typename iterator_t >
386	inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
387	while( it != end && !(*it)->get_type()->get_mutex() ) {
388	it++;
389	}
390
391	return it != end;
392	}
393
394	void Resolver::previsit( WaitForStmt * stmt ) {
395	visit_children = false;
396
397	// Resolve all clauses first
398	for( auto& clause : stmt->clauses ) {
399
400	TypeEnvironment env;
401	AlternativeFinder funcFinder( indexer, env );
402
403	// Find all alternatives for a function in canonical form
404	funcFinder.findWithAdjustment( clause.target.function );
405
406	if ( funcFinder.get_alternatives().empty() ) {
407	stringstream ss;
408	ss << "Use of undeclared indentifier '";
409	ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
410	ss << "' in call to waitfor";
411	throw SemanticError( ss.str() );
412	}
413
414	// Find all alternatives for all arguments in canonical form
415	std::vector< AlternativeFinder > argAlternatives;
416	funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
417
418	// List all combinations of arguments
419	std::vector< AltList > possibilities;
420	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
421
422	AltList func_candidates;
423	std::vector< AltList > args_candidates;
424
425	// For every possible function :
426	// try matching the arguments to the parameters
427	// not the other way around because we have more arguments than parameters
428	SemanticError errors;
429	for ( Alternative & func : funcFinder.get_alternatives() ) {
430	try {
431	PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
432	if( !pointer ) {
433	throw SemanticError( "candidate not viable: not a pointer type\n", func.expr->get_result() );
434	}
435
436	FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
437	if( !function ) {
438	throw SemanticError( "candidate not viable: not a function type\n", pointer->get_base() );
439	}
440
441
442	{
443	auto param = function->parameters.begin();
444	auto param_end = function->parameters.end();
445
446	if( !advance_to_mutex( param, param_end ) ) {
447	throw SemanticError("candidate function not viable: no mutex parameters\n", function);
448	}
449	}
450
451	Alternative newFunc( func );
452	// Strip reference from function
453	referenceToRvalueConversion( newFunc.expr );
454
455	// For all the set of arguments we have try to match it with the parameter of the current function alternative
456	for ( auto & argsList : possibilities ) {
457
458	try {
459	// Declare data structures need for resolution
460	OpenVarSet openVars;
461	AssertionSet resultNeed, resultHave;
462	TypeEnvironment resultEnv;
463
464	// Load type variables from arguemnts into one shared space
465	simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
466
467	// Make sure we don't widen any existing bindings
468	for ( auto & i : resultEnv ) {
469	i.allowWidening = false;
470	}
471
472	// Find any unbound type variables
473	resultEnv.extractOpenVars( openVars );
474
475	auto param = function->parameters.begin();
476	auto param_end = function->parameters.end();
477
478	// For every arguments of its set, check if it matches one of the parameter
479	// The order is important
480	for( auto & arg : argsList ) {
481
482	// Ignore non-mutex arguments
483	if( !advance_to_mutex( param, param_end ) ) {
484	// We ran out of parameters but still have arguments
485	// this function doesn't match
486	throw SemanticError("candidate function not viable: too many mutex arguments\n", function);
487	}
488
489	// Check if the argument matches the parameter type in the current scope
490	if( ! unify( (*param)->get_type(), arg.expr->get_result(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
491	// Type doesn't match
492	stringstream ss;
493	ss << "candidate function not viable: no known convertion from '";
494	arg.expr->get_result()->print( ss );
495	ss << "' to '";
496	(*param)->get_type()->print( ss );
497	ss << "'\n";
498	throw SemanticError(ss.str(), function);
499	}
500
501	param++;
502	}
503
504	// All arguments match !
505
506	// Check if parameters are missing
507	if( advance_to_mutex( param, param_end ) ) {
508	// We ran out of arguments but still have parameters left
509	// this function doesn't match
510	throw SemanticError("candidate function not viable: too few mutex arguments\n", function);
511	}
512
513	// All parameters match !
514
515	// Finish the expressions to tie in the proper environments
516	finishExpr( newFunc.expr, resultEnv );
517	for( Alternative & alt : argsList ) {
518	finishExpr( alt.expr, resultEnv );
519	}
520
521	// This is a match store it and save it for later
522	func_candidates.push_back( newFunc );
523	args_candidates.push_back( argsList );
524
525	}
526	catch( SemanticError &e ) {
527	errors.append( e );
528	}
529	}
530	}
531	catch( SemanticError &e ) {
532	errors.append( e );
533	}
534	}
535
536	// Make sure we got the right number of arguments
537	if( func_candidates.empty() ) { SemanticError top( "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
538	if( args_candidates.empty() ) { SemanticError top( "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
539	if( func_candidates.size() > 1 ) { SemanticError top( "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
540	if( args_candidates.size() > 1 ) { SemanticError top( "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
541
542
543	// Swap the results from the alternative with the unresolved values.
544	// Alternatives will handle deletion on destruction
545	std::swap( clause.target.function, func_candidates.front().expr );
546	for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
547	std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
548	}
549
550	// Resolve the conditions as if it were an IfStmt
551	// Resolve the statments normally
552	findSingleExpression( clause.condition, this->indexer );
553	clause.statement->accept( *visitor );
554	}
555
556
557	if( stmt->timeout.statement ) {
558	// Resolve the timeout as an size_t for now
559	// Resolve the conditions as if it were an IfStmt
560	// Resolve the statments normally
561	findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
562	findSingleExpression( stmt->timeout.condition, this->indexer );
563	stmt->timeout.statement->accept( *visitor );
564	}
565
566	if( stmt->orelse.statement ) {
567	// Resolve the conditions as if it were an IfStmt
568	// Resolve the statments normally
569	findSingleExpression( stmt->orelse.condition, this->indexer );
570	stmt->orelse.statement->accept( *visitor );
571	}
572	}
573
574	bool isStructOrUnion( Type * t ) {
575	t = t->stripReferences();
576	return dynamic_cast< StructInstType * >( t ) \|\| dynamic_cast< UnionInstType * >( t );
577	}
578
579	void Resolver::previsit( WithStmt * withStmt ) {
580	for ( Expression *& expr : withStmt->exprs ) {
581	TypeEnvironment env;
582	AlternativeFinder finder( indexer, env );
583	finder.findWithAdjustment( expr );
584
585	// only struct- and union-typed expressions are viable candidates
586	AltList candidates;
587	for ( Alternative & alt : finder.get_alternatives() ) {
588	if ( isStructOrUnion( alt.expr->result ) ) {
589	candidates.push_back( std::move( alt ) );
590	}
591	}
592
593	// choose the lowest cost expression among the candidates
594	AltList winners;
595	findMinCost( candidates.begin(), candidates.end(), back_inserter( winners ) );
596	if ( winners.size() == 0 ) {
597	throw SemanticError( "No reasonable alternatives for with statement expression: ", expr );
598	} else if ( winners.size() != 1 ) {
599	std::ostringstream stream;
600	stream << "Cannot choose between " << winners.size() << " alternatives for with statement expression\n";
601	expr->print( stream );
602	stream << "Alternatives are:\n";
603	printAlts( winners, stream, 1 );
604	throw SemanticError( stream.str() );
605	}
606
607	// there is one unambiguous interpretation - move the expression into the with statement
608	Alternative & alt = winners.front();
609	finishExpr( alt.expr, alt.env, expr->env );
610	delete expr;
611	expr = alt.expr;
612	alt.expr = nullptr;
613	}
614	}
615
616	template< typename T >
617	bool isCharType( T t ) {
618	if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
619	return bt->get_kind() == BasicType::Char \|\| bt->get_kind() == BasicType::SignedChar \|\|
620	bt->get_kind() == BasicType::UnsignedChar;
621	}
622	return false;
623	}
624
625	void Resolver::previsit( SingleInit *singleInit ) {
626	visit_children = false;
627	// resolve initialization using the possibilities as determined by the currentObject cursor
628	Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
629	findSingleExpression( newExpr, indexer );
630	InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
631
632	// move cursor to the object that is actually initialized
633	currentObject.setNext( initExpr->get_designation() );
634
635	// discard InitExpr wrapper and retain relevant pieces
636	newExpr = initExpr->expr;
637	initExpr->expr = nullptr;
638	std::swap( initExpr->env, newExpr->env );
639	std::swap( initExpr->inferParams, newExpr->inferParams ) ;
640	delete initExpr;
641
642	// get the actual object's type (may not exactly match what comes back from the resolver due to conversions)
643	Type * initContext = currentObject.getCurrentType();
644
645	removeExtraneousCast( newExpr, indexer );
646
647	// check if actual object's type is char[]
648	if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
649	if ( isCharType( at->get_base() ) ) {
650	// check if the resolved type is char *
651	if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
652	if ( isCharType( pt->get_base() ) ) {
653	if ( CastExpr ce = dynamic_cast< CastExpr >( newExpr ) ) {
654	// strip cast if we're initializing a char[] with a char *, e.g. char x[] = "hello";
655	newExpr = ce->get_arg();
656	ce->set_arg( nullptr );
657	std::swap( ce->env, newExpr->env );
658	delete ce;
659	}
660	}
661	}
662	}
663	}
664
665	// set initializer expr to resolved express
666	singleInit->value = newExpr;
667
668	// move cursor to next object in preparation for next initializer
669	currentObject.increment();
670	}
671
672	void Resolver::previsit( ListInit * listInit ) {
673	visit_children = false;
674	// move cursor into brace-enclosed initializer-list
675	currentObject.enterListInit();
676	// xxx - fix this so that the list isn't copied, iterator should be used to change current element
677	std::list<Designation *> newDesignations;
678	for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
679	// iterate designations and initializers in pairs, moving the cursor to the current designated object and resolving
680	// the initializer against that object.
681	Designation * des = std::get<0>(p);
682	Initializer * init = std::get<1>(p);
683	newDesignations.push_back( currentObject.findNext( des ) );
684	init->accept( *visitor );
685	}
686	// set the set of 'resolved' designations and leave the brace-enclosed initializer-list
687	listInit->get_designations() = newDesignations; // xxx - memory management
688	currentObject.exitListInit();
689
690	// xxx - this part has not be folded into CurrentObject yet
691	// } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
692	// Type * base = tt->get_baseType()->get_base();
693	// if ( base ) {
694	// // know the implementation type, so try using that as the initContext
695	// ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
696	// currentObject = &tmpObj;
697	// visit( listInit );
698	// } else {
699	// // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
700	// Parent::visit( listInit );
701	// }
702	// } else {
703	}
704
705	// ConstructorInit - fall back on C-style initializer
706	void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
707	// could not find valid constructor, or found an intrinsic constructor
708	// fall back on C-style initializer
709	delete ctorInit->get_ctor();
710	ctorInit->set_ctor( NULL );
711	delete ctorInit->get_dtor();
712	ctorInit->set_dtor( NULL );
713	maybeAccept( ctorInit->get_init(), *visitor );
714	}
715
716	// needs to be callable from outside the resolver, so this is a standalone function
717	void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
718	assert( ctorInit );
719	PassVisitor<Resolver> resolver( indexer );
720	ctorInit->accept( resolver );
721	}
722
723	void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
724	assert( stmtExpr );
725	PassVisitor<Resolver> resolver( indexer );
726	stmtExpr->accept( resolver );
727	}
728
729	void Resolver::previsit( ConstructorInit *ctorInit ) {
730	visit_children = false;
731	// xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
732	maybeAccept( ctorInit->get_ctor(), *visitor );
733	maybeAccept( ctorInit->get_dtor(), *visitor );
734
735	// found a constructor - can get rid of C-style initializer
736	delete ctorInit->get_init();
737	ctorInit->set_init( NULL );
738
739	// intrinsic single parameter constructors and destructors do nothing. Since this was
740	// implicitly generated, there's no way for it to have side effects, so get rid of it
741	// to clean up generated code.
742	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->get_ctor() ) ) {
743	delete ctorInit->get_ctor();
744	ctorInit->set_ctor( NULL );
745	}
746
747	if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->get_dtor() ) ) {
748	delete ctorInit->get_dtor();
749	ctorInit->set_dtor( NULL );
750	}
751
752	// xxx - todo -- what about arrays?
753	// if ( dtor == NULL && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
754	// // can reduce the constructor down to a SingleInit using the
755	// // second argument from the ctor call, since
756	// delete ctorInit->get_ctor();
757	// ctorInit->set_ctor( NULL );
758
759	// Expression * arg =
760	// ctorInit->set_init( new SingleInit( arg ) );
761	// }
762	}
763	} // namespace ResolvExpr
764
765	// Local Variables: //
766	// tab-width: 4 //
767	// mode: c++ //
768	// compile-command: "make install" //
769	// End: //

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