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source: src/ResolvExpr/AlternativeFinder.cc @ c8c03683

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsctordeferred_resndemanglerenumforall-pointer-decaygc_noraiijacob/cs343-translationjenkins-sandboxmemorynew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since c8c03683 was c8c03683, checked in by Peter A. Buhr <pabuhr@…>, 8 years ago
Merge branch 'master' of plg2:software/cfa/cfa-cc
Property mode set to `100644`
File size: 41.1 KB

Line
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	// AlternativeFinder.cc --
8	//
9	// Author : Richard C. Bilson
10	// Created On : Sat May 16 23:52:08 2015
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Mon Jun 13 16:13:54 2016
13	// Update Count : 25
14	//
15
16	#include <list>
17	#include <iterator>
18	#include <algorithm>
19	#include <functional>
20	#include <cassert>
21
22	#include "AlternativeFinder.h"
23	#include "Alternative.h"
24	#include "Cost.h"
25	#include "typeops.h"
26	#include "Unify.h"
27	#include "RenameVars.h"
28	#include "SynTree/Type.h"
29	#include "SynTree/Declaration.h"
30	#include "SynTree/Expression.h"
31	#include "SynTree/Initializer.h"
32	#include "SynTree/Visitor.h"
33	#include "SymTab/Indexer.h"
34	#include "SymTab/Mangler.h"
35	#include "SynTree/TypeSubstitution.h"
36	#include "SymTab/Validate.h"
37	#include "Designators/Processor.h"
38	#include "Tuples/TupleAssignment.h"
39	#include "Tuples/NameMatcher.h"
40	#include "Common/utility.h"
41	#include "InitTweak/InitTweak.h"
42
43	extern bool resolvep;
44	#define PRINT( text ) if ( resolvep ) { text }
45	//#define DEBUG_COST
46
47	namespace ResolvExpr {
48	Expression resolveInVoidContext( Expression expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
49	CastExpr *castToVoid = new CastExpr( expr );
50
51	AlternativeFinder finder( indexer, env );
52	finder.findWithAdjustment( castToVoid );
53
54	// it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
55	// interpretations, an exception has already been thrown.
56	assert( finder.get_alternatives().size() == 1 );
57	CastExpr newExpr = dynamic_cast< CastExpr >( finder.get_alternatives().front().expr );
58	assert( newExpr );
59	env = finder.get_alternatives().front().env;
60	return newExpr->get_arg()->clone();
61	}
62
63	namespace {
64	void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
65	for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
66	i->print( os, indent );
67	os << std::endl;
68	}
69	}
70
71	void makeExprList( const AltList &in, std::list< Expression* > &out ) {
72	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
73	out.push_back( i->expr->clone() );
74	}
75	}
76
77	Cost sumCost( const AltList &in ) {
78	Cost total;
79	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
80	total += i->cost;
81	}
82	return total;
83	}
84
85	struct PruneStruct {
86	bool isAmbiguous;
87	AltList::iterator candidate;
88	PruneStruct() {}
89	PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
90	};
91
92	/// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
93	template< typename InputIterator, typename OutputIterator >
94	void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
95	// select the alternatives that have the minimum conversion cost for a particular set of result types
96	std::map< std::string, PruneStruct > selected;
97	for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
98	PruneStruct current( candidate );
99	std::string mangleName;
100	for ( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
101	Type newType = (retType)->clone();
102	candidate->env.apply( newType );
103	mangleName += SymTab::Mangler::mangle( newType );
104	delete newType;
105	}
106	std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
107	if ( mapPlace != selected.end() ) {
108	if ( candidate->cost < mapPlace->second.candidate->cost ) {
109	PRINT(
110	std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
111	)
112	selected[ mangleName ] = current;
113	} else if ( candidate->cost == mapPlace->second.candidate->cost ) {
114	PRINT(
115	std::cerr << "marking ambiguous" << std::endl;
116	)
117	mapPlace->second.isAmbiguous = true;
118	}
119	} else {
120	selected[ mangleName ] = current;
121	}
122	}
123
124	PRINT(
125	std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
126	)
127
128	// accept the alternatives that were unambiguous
129	for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
130	if ( ! target->second.isAmbiguous ) {
131	Alternative &alt = *target->second.candidate;
132	for ( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
133	alt.env.applyFree( *result );
134	}
135	*out++ = alt;
136	}
137	}
138
139	}
140
141	template< typename InputIterator, typename OutputIterator >
142	void findMinCost( InputIterator begin, InputIterator end, OutputIterator out ) {
143	AltList alternatives;
144
145	// select the alternatives that have the minimum parameter cost
146	Cost minCost = Cost::infinity;
147	for ( AltList::iterator i = begin; i != end; ++i ) {
148	if ( i->cost < minCost ) {
149	minCost = i->cost;
150	i->cost = i->cvtCost;
151	alternatives.clear();
152	alternatives.push_back( *i );
153	} else if ( i->cost == minCost ) {
154	i->cost = i->cvtCost;
155	alternatives.push_back( *i );
156	}
157	}
158	std::copy( alternatives.begin(), alternatives.end(), out );
159	}
160
161	template< typename InputIterator >
162	void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
163	while ( begin != end ) {
164	result.simpleCombine( (*begin++).env );
165	}
166	}
167
168	void renameTypes( Expression *expr ) {
169	for ( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
170	(*i)->accept( global_renamer );
171	}
172	}
173	}
174
175	template< typename InputIterator, typename OutputIterator >
176	void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
177	while ( begin != end ) {
178	AlternativeFinder finder( indexer, env );
179	finder.findWithAdjustment( *begin );
180	// XXX either this
181	//Designators::fixDesignations( finder, (*begin++)->get_argName() );
182	// or XXX this
183	begin++;
184	PRINT(
185	std::cerr << "findSubExprs" << std::endl;
186	printAlts( finder.alternatives, std::cerr );
187	)
188	*out++ = finder;
189	}
190	}
191
192	AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
193	: indexer( indexer ), env( env ) {
194	}
195
196	void AlternativeFinder::find( Expression *expr, bool adjust ) {
197	expr->accept( *this );
198	if ( alternatives.empty() ) {
199	throw SemanticError( "No reasonable alternatives for expression ", expr );
200	}
201	for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
202	if ( adjust ) {
203	adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
204	}
205	}
206	PRINT(
207	std::cerr << "alternatives before prune:" << std::endl;
208	printAlts( alternatives, std::cerr );
209	)
210	AltList::iterator oldBegin = alternatives.begin();
211	pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
212	if ( alternatives.begin() == oldBegin ) {
213	std::ostringstream stream;
214	stream << "Can't choose between alternatives for expression ";
215	expr->print( stream );
216	stream << "Alternatives are:";
217	AltList winners;
218	findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
219	printAlts( winners, stream, 8 );
220	throw SemanticError( stream.str() );
221	}
222	alternatives.erase( oldBegin, alternatives.end() );
223	PRINT(
224	std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
225	)
226	}
227
228	void AlternativeFinder::findWithAdjustment( Expression *expr ) {
229	find( expr, true );
230	}
231
232	template< typename StructOrUnionType >
233	void AlternativeFinder::addAggMembers( StructOrUnionType aggInst, Expression expr, const Cost &newCost, const std::string &name ) {
234	std::list< Declaration* > members;
235	aggInst->lookup( name, members );
236	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
237	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
238	alternatives.push_back( Alternative( new MemberExpr( dwt->clone(), expr->clone() ), env, newCost ) );
239	renameTypes( alternatives.back().expr );
240	} else {
241	assert( false );
242	}
243	}
244	}
245
246	void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
247	alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
248	}
249
250	Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
251	ApplicationExpr appExpr = dynamic_cast< ApplicationExpr >( alt.expr );
252	assert( appExpr );
253	PointerType pointer = dynamic_cast< PointerType >( appExpr->get_function()->get_results().front() );
254	assert( pointer );
255	FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() );
256	assert( function );
257
258	Cost convCost( 0, 0, 0 );
259	std::list< DeclarationWithType* >& formals = function->get_parameters();
260	std::list< DeclarationWithType* >::iterator formal = formals.begin();
261	std::list< Expression* >& actuals = appExpr->get_args();
262	for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
263	PRINT(
264	std::cerr << "actual expression:" << std::endl;
265	(*actualExpr)->print( std::cerr, 8 );
266	std::cerr << "--- results are" << std::endl;
267	printAll( (*actualExpr)->get_results(), std::cerr, 8 );
268	)
269	std::list< DeclarationWithType* >::iterator startFormal = formal;
270	Cost actualCost;
271	for ( std::list< Type* >::iterator actual = (actualExpr)->get_results().begin(); actual != (actualExpr)->get_results().end(); ++actual ) {
272	if ( formal == formals.end() ) {
273	if ( function->get_isVarArgs() ) {
274	convCost += Cost( 1, 0, 0 );
275	break;
276	} else {
277	return Cost::infinity;
278	}
279	}
280	PRINT(
281	std::cerr << std::endl << "converting ";
282	(*actual)->print( std::cerr, 8 );
283	std::cerr << std::endl << " to ";
284	(*formal)->get_type()->print( std::cerr, 8 );
285	)
286	Cost newCost = conversionCost( actual, (formal)->get_type(), indexer, alt.env );
287	PRINT(
288	std::cerr << std::endl << "cost is" << newCost << std::endl;
289	)
290
291	if ( newCost == Cost::infinity ) {
292	return newCost;
293	}
294	convCost += newCost;
295	actualCost += newCost;
296
297	convCost += Cost( 0, polyCost( (formal)->get_type(), alt.env, indexer ) + polyCost( actual, alt.env, indexer ), 0 );
298
299	formal++;
300	}
301	if ( actualCost != Cost( 0, 0, 0 ) ) {
302	std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
303	startFormalPlusOne++;
304	if ( formal == startFormalPlusOne ) {
305	// not a tuple type
306	Type newType = (startFormal)->get_type()->clone();
307	alt.env.apply( newType );
308	actualExpr = new CastExpr( actualExpr, newType );
309	} else {
310	TupleType *newType = new TupleType( Type::Qualifiers() );
311	for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
312	newType->get_types().push_back( (*i)->get_type()->clone() );
313	}
314	alt.env.apply( newType );
315	actualExpr = new CastExpr( actualExpr, newType );
316	}
317	}
318
319	}
320	if ( formal != formals.end() ) {
321	return Cost::infinity;
322	}
323
324	for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
325	PRINT(
326	std::cerr << std::endl << "converting ";
327	assert->second.actualType->print( std::cerr, 8 );
328	std::cerr << std::endl << " to ";
329	assert->second.formalType->print( std::cerr, 8 );
330	)
331	Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
332	PRINT(
333	std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
334	)
335	if ( newCost == Cost::infinity ) {
336	return newCost;
337	}
338	convCost += newCost;
339
340	convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
341	}
342
343	return convCost;
344	}
345
346	/// Adds type variables to the open variable set and marks their assertions
347	void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
348	for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
349	unifiableVars[ (tyvar)->get_name() ] = (tyvar)->get_kind();
350	for ( std::list< DeclarationWithType* >::iterator assert = (tyvar)->get_assertions().begin(); assert != (tyvar)->get_assertions().end(); ++assert ) {
351	needAssertions[ *assert ] = true;
352	}
353	/// needAssertions.insert( needAssertions.end(), (tyvar)->get_assertions().begin(), (tyvar)->get_assertions().end() );
354	}
355	}
356
357	bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /const/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
358	simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
359	// make sure we don't widen any existing bindings
360	for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
361	i->allowWidening = false;
362	}
363	resultEnv.extractOpenVars( openVars );
364
365	/*
366	Tuples::NameMatcher matcher( formals );
367	try {
368	matcher.match( actuals );
369	} catch ( Tuples::NoMatch &e ) {
370	std::cerr << "Alternative doesn't match: " << e.message << std::endl;
371	}
372	*/
373	std::list< DeclarationWithType* >::iterator formal = formals.begin();
374	for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
375	for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
376	if ( formal == formals.end() ) {
377	return isVarArgs;
378	}
379	PRINT(
380	std::cerr << "formal type is ";
381	(*formal)->get_type()->print( std::cerr );
382	std::cerr << std::endl << "actual type is ";
383	(*actual)->print( std::cerr );
384	std::cerr << std::endl;
385	)
386	if ( ! unify( (formal)->get_type(), actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
387	return false;
388	}
389	formal++;
390	}
391	}
392	// Handling of default values
393	while ( formal != formals.end() ) {
394	if ( ObjectDecl od = dynamic_cast<ObjectDecl >( *formal ) )
395	if ( SingleInit si = dynamic_cast<SingleInit >( od->get_init() ))
396	// so far, only constant expressions are accepted as default values
397	if ( ConstantExpr cnstexpr = dynamic_cast<ConstantExpr >( si->get_value()) )
398	if ( Constant cnst = dynamic_cast<Constant >( cnstexpr->get_constant() ) )
399	if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
400	// XXX Don't know if this is right
401	actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
402	formal++;
403	if ( formal == formals.end()) break;
404	}
405	return false;
406	}
407	return true;
408	}
409
410	static const int recursionLimit = 10;
411
412	void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
413	for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
414	if ( i->second == true ) {
415	i->first->accept( indexer );
416	}
417	}
418	}
419
420	template< typename ForwardIterator, typename OutputIterator >
421	void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, int level, const SymTab::Indexer &indexer, OutputIterator out ) {
422	if ( begin == end ) {
423	if ( newNeed.empty() ) {
424	*out++ = newAlt;
425	return;
426	} else if ( level >= recursionLimit ) {
427	throw SemanticError( "Too many recursive assertions" );
428	} else {
429	AssertionSet newerNeed;
430	PRINT(
431	std::cerr << "recursing with new set:" << std::endl;
432	printAssertionSet( newNeed, std::cerr, 8 );
433	)
434	inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, level+1, indexer, out );
435	return;
436	}
437	}
438
439	ForwardIterator cur = begin++;
440	if ( ! cur->second ) {
441	inferRecursive( begin, end, newAlt, openVars, decls, newNeed, level, indexer, out );
442	}
443	DeclarationWithType *curDecl = cur->first;
444	PRINT(
445	std::cerr << "inferRecursive: assertion is ";
446	curDecl->print( std::cerr );
447	std::cerr << std::endl;
448	)
449	std::list< DeclarationWithType* > candidates;
450	decls.lookupId( curDecl->get_name(), candidates );
451	/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
452	for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
453	PRINT(
454	std::cerr << "inferRecursive: candidate is ";
455	(*candidate)->print( std::cerr );
456	std::cerr << std::endl;
457	)
458	AssertionSet newHave, newerNeed( newNeed );
459	TypeEnvironment newEnv( newAlt.env );
460	OpenVarSet newOpenVars( openVars );
461	Type adjType = (candidate)->get_type()->clone();
462	adjustExprType( adjType, newEnv, indexer );
463	adjType->accept( global_renamer );
464	PRINT(
465	std::cerr << "unifying ";
466	curDecl->get_type()->print( std::cerr );
467	std::cerr << " with ";
468	adjType->print( std::cerr );
469	std::cerr << std::endl;
470	)
471	if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
472	PRINT(
473	std::cerr << "success!" << std::endl;
474	)
475	SymTab::Indexer newDecls( decls );
476	addToIndexer( newHave, newDecls );
477	Alternative newerAlt( newAlt );
478	newerAlt.env = newEnv;
479	assert( (*candidate)->get_uniqueId() );
480	Expression varExpr = new VariableExpr( static_cast< DeclarationWithType >( Declaration::declFromId( (*candidate)->get_uniqueId() ) ) );
481	deleteAll( varExpr->get_results() );
482	varExpr->get_results().clear();
483	varExpr->get_results().push_front( adjType->clone() );
484	PRINT(
485	std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
486	curDecl->print( std::cerr );
487	std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
488	(*candidate)->print( std::cerr );
489	std::cerr << std::endl;
490	)
491	ApplicationExpr appExpr = static_cast< ApplicationExpr >( newerAlt.expr );
492	// XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
493	appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
494	inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, level, indexer, out );
495	} else {
496	delete adjType;
497	}
498	}
499	}
500
501	template< typename OutputIterator >
502	void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
503	// PRINT(
504	// std::cerr << "inferParameters: assertions needed are" << std::endl;
505	// printAll( need, std::cerr, 8 );
506	// )
507	SymTab::Indexer decls( indexer );
508	PRINT(
509	std::cerr << "============= original indexer" << std::endl;
510	indexer.print( std::cerr );
511	std::cerr << "============= new indexer" << std::endl;
512	decls.print( std::cerr );
513	)
514	addToIndexer( have, decls );
515	AssertionSet newNeed;
516	inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, 0, indexer, out );
517	// PRINT(
518	// std::cerr << "declaration 14 is ";
519	// Declaration::declFromId
520	// *out++ = newAlt;
521	// )
522	}
523
524	template< typename OutputIterator >
525	void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
526	OpenVarSet openVars;
527	AssertionSet resultNeed, resultHave;
528	TypeEnvironment resultEnv;
529	makeUnifiableVars( funcType, openVars, resultNeed );
530	if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
531	ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
532	Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
533	makeExprList( actualAlt, appExpr->get_args() );
534	PRINT(
535	std::cerr << "need assertions:" << std::endl;
536	printAssertionSet( resultNeed, std::cerr, 8 );
537	)
538	inferParameters( resultNeed, resultHave, newAlt, openVars, out );
539	}
540	}
541
542	void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
543	bool doneInit = false;
544	AlternativeFinder funcOpFinder( indexer, env );
545
546	AlternativeFinder funcFinder( indexer, env );
547
548	{
549	std::string fname = InitTweak::getFunctionName( untypedExpr );
550	if ( fname == "&&" ) {
551	VoidType v = Type::Qualifiers(); // resolve to type void *
552	PointerType pt( Type::Qualifiers(), v.clone() );
553	UntypedExpr *vexpr = untypedExpr->clone();
554	vexpr->get_results().push_front( pt.clone() );
555	alternatives.push_back( Alternative( vexpr, env, Cost()) );
556	return;
557	}
558	}
559
560	funcFinder.findWithAdjustment( untypedExpr->get_function() );
561	std::list< AlternativeFinder > argAlternatives;
562	findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
563
564	std::list< AltList > possibilities;
565	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
566
567	Tuples::TupleAssignSpotter tassign( this );
568	if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
569	// take care of possible tuple assignments, or discard expression
570	return;
571	} // else ...
572
573	AltList candidates;
574	SemanticError errors;
575
576	for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
577	try {
578	PRINT(
579	std::cerr << "working on alternative: " << std::endl;
580	func->print( std::cerr, 8 );
581	)
582	// check if the type is pointer to function
583	PointerType *pointer;
584	if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
585	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
586	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
587	// XXX
588	//Designators::check_alternative( function, *actualAlt );
589	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
590	}
591	} else if ( TypeInstType typeInst = dynamic_cast< TypeInstType >( pointer->get_base() ) ) {
592	EqvClass eqvClass;
593	if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
594	if ( FunctionType function = dynamic_cast< FunctionType >( eqvClass.type ) ) {
595	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
596	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
597	} // for
598	} // if
599	} // if
600	} // if
601	} else {
602	// seek a function operator that's compatible
603	if ( ! doneInit ) {
604	doneInit = true;
605	NameExpr *opExpr = new NameExpr( "?()" );
606	try {
607	funcOpFinder.findWithAdjustment( opExpr );
608	} catch( SemanticError &e ) {
609	// it's ok if there aren't any defined function ops
610	}
611	PRINT(
612	std::cerr << "known function ops:" << std::endl;
613	printAlts( funcOpFinder.alternatives, std::cerr, 8 );
614	)
615	}
616
617	for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
618	// check if the type is pointer to function
619	PointerType *pointer;
620	if ( funcOp->expr->get_results().size() == 1
621	&& ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
622	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
623	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
624	AltList currentAlt;
625	currentAlt.push_back( *func );
626	currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
627	makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
628	} // for
629	} // if
630	} // if
631	} // for
632	} // if
633	} catch ( SemanticError &e ) {
634	errors.append( e );
635	}
636	} // for
637
638	// Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
639	if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
640
641	for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
642	Cost cvtCost = computeConversionCost( *withFunc, indexer );
643
644	PRINT(
645	ApplicationExpr appExpr = dynamic_cast< ApplicationExpr >( withFunc->expr );
646	assert( appExpr );
647	PointerType pointer = dynamic_cast< PointerType >( appExpr->get_function()->get_results().front() );
648	assert( pointer );
649	FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() );
650	assert( function );
651	std::cerr << "Case +++++++++++++" << std::endl;
652	std::cerr << "formals are:" << std::endl;
653	printAll( function->get_parameters(), std::cerr, 8 );
654	std::cerr << "actuals are:" << std::endl;
655	printAll( appExpr->get_args(), std::cerr, 8 );
656	std::cerr << "bindings are:" << std::endl;
657	withFunc->env.print( std::cerr, 8 );
658	std::cerr << "cost of conversion is:" << cvtCost << std::endl;
659	)
660	if ( cvtCost != Cost::infinity ) {
661	withFunc->cvtCost = cvtCost;
662	alternatives.push_back( *withFunc );
663	} // if
664	} // for
665	candidates.clear();
666	candidates.splice( candidates.end(), alternatives );
667
668	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
669	}
670
671	bool isLvalue( Expression *expr ) {
672	for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
673	if ( !(*i)->get_isLvalue() ) return false;
674	} // for
675	return true;
676	}
677
678	void AlternativeFinder::visit( AddressExpr *addressExpr ) {
679	AlternativeFinder finder( indexer, env );
680	finder.find( addressExpr->get_arg() );
681	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
682	if ( isLvalue( i->expr ) ) {
683	alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
684	} // if
685	} // for
686	}
687
688	void AlternativeFinder::visit( CastExpr *castExpr ) {
689	for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
690	SymTab::validateType( *i, &indexer );
691	adjustExprType( *i, env, indexer );
692	} // for
693
694	AlternativeFinder finder( indexer, env );
695	finder.findWithAdjustment( castExpr->get_arg() );
696
697	AltList candidates;
698	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
699	AssertionSet needAssertions, haveAssertions;
700	OpenVarSet openVars;
701
702	// It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
703	// cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
704	// that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
705	// to.
706	int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
707	if ( discardedValues < 0 ) continue;
708	std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
709	std::advance( candidate_end, castExpr->get_results().size() );
710	// unification run for side-effects
711	unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
712	(*i).expr->get_results().begin(), candidate_end,
713	i->env, needAssertions, haveAssertions, openVars, indexer );
714	Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
715	castExpr->get_results().begin(), castExpr->get_results().end(),
716	indexer, i->env );
717	if ( thisCost != Cost::infinity ) {
718	// count one safe conversion for each value that is thrown away
719	thisCost += Cost( 0, 0, discardedValues );
720	CastExpr *newExpr = castExpr->clone();
721	newExpr->set_arg( i->expr->clone() );
722	candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
723	} // if
724	} // for
725
726	// findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
727	// cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
728	// selects first based on argument cost, then on conversion cost.
729	AltList minArgCost;
730	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
731	findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
732	}
733
734	void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
735	AlternativeFinder funcFinder( indexer, env );
736	funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
737
738	for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
739	if ( agg->expr->get_results().size() == 1 ) {
740	if ( StructInstType structInst = dynamic_cast< StructInstType >( agg->expr->get_results().front() ) ) {
741	addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
742	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( agg->expr->get_results().front() ) ) {
743	addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
744	} // if
745	} // if
746	} // for
747	}
748
749	void AlternativeFinder::visit( MemberExpr *memberExpr ) {
750	alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
751	}
752
753	void AlternativeFinder::visit( NameExpr *nameExpr ) {
754	std::list< DeclarationWithType* > declList;
755	indexer.lookupId( nameExpr->get_name(), declList );
756	PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
757	for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
758	VariableExpr newExpr( *i, nameExpr->get_argName() );
759	newExpr.set_extension( nameExpr->get_extension() );
760	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
761	PRINT(
762	std::cerr << "decl is ";
763	(*i)->print( std::cerr );
764	std::cerr << std::endl;
765	std::cerr << "newExpr is ";
766	newExpr.print( std::cerr );
767	std::cerr << std::endl;
768	)
769	renameTypes( alternatives.back().expr );
770	if ( StructInstType structInst = dynamic_cast< StructInstType >( (*i)->get_type() ) ) {
771	addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
772	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( (*i)->get_type() ) ) {
773	addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
774	} // if
775	} // for
776	}
777
778	void AlternativeFinder::visit( VariableExpr *variableExpr ) {
779	alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
780	}
781
782	void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
783	alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
784	}
785
786	void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
787	if ( sizeofExpr->get_isType() ) {
788	alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
789	} else {
790	// find all alternatives for the argument to sizeof
791	AlternativeFinder finder( indexer, env );
792	finder.find( sizeofExpr->get_expr() );
793	// find the lowest cost alternative among the alternatives, otherwise ambiguous
794	AltList winners;
795	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
796	if ( winners.size() != 1 ) {
797	throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
798	} // if
799	// return the lowest cost alternative for the argument
800	Alternative &choice = winners.front();
801	alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
802	} // if
803	}
804
805	void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
806	if ( alignofExpr->get_isType() ) {
807	alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
808	} else {
809	// find all alternatives for the argument to sizeof
810	AlternativeFinder finder( indexer, env );
811	finder.find( alignofExpr->get_expr() );
812	// find the lowest cost alternative among the alternatives, otherwise ambiguous
813	AltList winners;
814	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
815	if ( winners.size() != 1 ) {
816	throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
817	} // if
818	// return the lowest cost alternative for the argument
819	Alternative &choice = winners.front();
820	alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
821	} // if
822	}
823
824	template< typename StructOrUnionType >
825	void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
826	std::list< Declaration* > members;
827	aggInst->lookup( name, members );
828	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
829	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
830	alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt->clone() ), env, Cost::zero ) );
831	renameTypes( alternatives.back().expr );
832	} else {
833	assert( false );
834	}
835	}
836	}
837
838	void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
839	AlternativeFinder funcFinder( indexer, env );
840	if ( StructInstType structInst = dynamic_cast< StructInstType >( offsetofExpr->get_type() ) ) {
841	addOffsetof( structInst, offsetofExpr->get_member() );
842	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( offsetofExpr->get_type() ) ) {
843	addOffsetof( unionInst, offsetofExpr->get_member() );
844	}
845	}
846
847	void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
848	alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
849	}
850
851	void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
852	alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
853	}
854
855	void AlternativeFinder::resolveAttr( DeclarationWithType funcDecl, FunctionType function, Type *argType, const TypeEnvironment &env ) {
856	// assume no polymorphism
857	// assume no implicit conversions
858	assert( function->get_parameters().size() == 1 );
859	PRINT(
860	std::cerr << "resolvAttr: funcDecl is ";
861	funcDecl->print( std::cerr );
862	std::cerr << " argType is ";
863	argType->print( std::cerr );
864	std::cerr << std::endl;
865	)
866	if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
867	alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
868	for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
869	alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
870	} // for
871	} // if
872	}
873
874	void AlternativeFinder::visit( AttrExpr *attrExpr ) {
875	// assume no 'pointer-to-attribute'
876	NameExpr nameExpr = dynamic_cast< NameExpr >( attrExpr->get_attr() );
877	assert( nameExpr );
878	std::list< DeclarationWithType* > attrList;
879	indexer.lookupId( nameExpr->get_name(), attrList );
880	if ( attrExpr->get_isType() \|\| attrExpr->get_expr() ) {
881	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
882	// check if the type is function
883	if ( FunctionType function = dynamic_cast< FunctionType >( (*i)->get_type() ) ) {
884	// assume exactly one parameter
885	if ( function->get_parameters().size() == 1 ) {
886	if ( attrExpr->get_isType() ) {
887	resolveAttr( *i, function, attrExpr->get_type(), env );
888	} else {
889	AlternativeFinder finder( indexer, env );
890	finder.find( attrExpr->get_expr() );
891	for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
892	if ( choice->expr->get_results().size() == 1 ) {
893	resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
894	} // fi
895	} // for
896	} // if
897	} // if
898	} // if
899	} // for
900	} else {
901	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
902	VariableExpr newExpr( *i );
903	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
904	renameTypes( alternatives.back().expr );
905	} // for
906	} // if
907	}
908
909	void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
910	AlternativeFinder firstFinder( indexer, env );
911	firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
912	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
913	AlternativeFinder secondFinder( indexer, first->env );
914	secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
915	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
916	LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
917	alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
918	}
919	}
920	}
921
922	void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
923	AlternativeFinder firstFinder( indexer, env );
924	firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
925	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
926	AlternativeFinder secondFinder( indexer, first->env );
927	secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
928	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
929	AlternativeFinder thirdFinder( indexer, second->env );
930	thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
931	for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
932	OpenVarSet openVars;
933	AssertionSet needAssertions, haveAssertions;
934	Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
935	std::list< Type* > commonTypes;
936	if ( unifyList( second->expr->get_results().begin(), second->expr->get_results().end(), third->expr->get_results().begin(), third->expr->get_results().end(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
937	ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
938	std::list< Type* >::const_iterator original = second->expr->get_results().begin();
939	std::list< Type* >::const_iterator commonType = commonTypes.begin();
940	for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
941	if ( *commonType ) {
942	newExpr->get_results().push_back( *commonType );
943	} else {
944	newExpr->get_results().push_back( (*original)->clone() );
945	} // if
946	} // for
947	newAlt.expr = newExpr;
948	inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
949	} // if
950	} // for
951	} // for
952	} // for
953	}
954
955	void AlternativeFinder::visit( CommaExpr *commaExpr ) {
956	TypeEnvironment newEnv( env );
957	Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
958	AlternativeFinder secondFinder( indexer, newEnv );
959	secondFinder.findWithAdjustment( commaExpr->get_arg2() );
960	for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
961	alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
962	} // for
963	delete newFirstArg;
964	}
965
966	void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
967	std::list< AlternativeFinder > subExprAlternatives;
968	findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
969	std::list< AltList > possibilities;
970	combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
971	for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
972	TupleExpr *newExpr = new TupleExpr;
973	makeExprList( *i, newExpr->get_exprs() );
974	for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
975	for ( std::list< Type* >::const_iterator resultType = (resultExpr)->get_results().begin(); resultType != (resultExpr)->get_results().end(); ++resultType ) {
976	newExpr->get_results().push_back( (*resultType)->clone() );
977	} // for
978	} // for
979
980	TypeEnvironment compositeEnv;
981	simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
982	alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
983	} // for
984	}
985
986	void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
987	alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
988	}
989	} // namespace ResolvExpr
990
991	// Local Variables: //
992	// tab-width: 4 //
993	// mode: c++ //
994	// compile-command: "make install" //
995	// End: //

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