Context Navigation

source: src/ResolvExpr/AlternativeFinder.cc @ aefcc3b

aaron-thesisarm-ehcleanup-dtorsdeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since aefcc3b was aefcc3b, checked in by Rob Schluntz <rschlunt@…>, 7 years ago
major change to instantiateFunction to match arguments against the formal parameter's structure rather than the reverse
Property mode set to `100644`
File size: 44.2 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 Jul 4 17:02:51 2016
13	// Update Count : 29
14	//
15
16	#include <list>
17	#include <iterator>
18	#include <algorithm>
19	#include <functional>
20	#include <cassert>
21	#include <unordered_map>
22	#include <utility>
23	#include <vector>
24
25	#include "AlternativeFinder.h"
26	#include "Alternative.h"
27	#include "Cost.h"
28	#include "typeops.h"
29	#include "Unify.h"
30	#include "RenameVars.h"
31	#include "SynTree/Type.h"
32	#include "SynTree/Declaration.h"
33	#include "SynTree/Expression.h"
34	#include "SynTree/Initializer.h"
35	#include "SynTree/Visitor.h"
36	#include "SymTab/Indexer.h"
37	#include "SymTab/Mangler.h"
38	#include "SynTree/TypeSubstitution.h"
39	#include "SymTab/Validate.h"
40	#include "Tuples/Tuples.h"
41	#include "Common/utility.h"
42	#include "InitTweak/InitTweak.h"
43	#include "ResolveTypeof.h"
44
45	extern bool resolvep;
46	#define PRINT( text ) if ( resolvep ) { text }
47	//#define DEBUG_COST
48
49	namespace ResolvExpr {
50	Expression resolveInVoidContext( Expression expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
51	CastExpr *castToVoid = new CastExpr( expr );
52
53	AlternativeFinder finder( indexer, env );
54	finder.findWithAdjustment( castToVoid );
55
56	// it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
57	// interpretations, an exception has already been thrown.
58	assert( finder.get_alternatives().size() == 1 );
59	CastExpr newExpr = dynamic_cast< CastExpr >( finder.get_alternatives().front().expr );
60	assert( newExpr );
61	env = finder.get_alternatives().front().env;
62	return newExpr->get_arg()->clone();
63	}
64
65	Cost sumCost( const AltList &in ) {
66	Cost total;
67	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
68	total += i->cost;
69	}
70	return total;
71	}
72
73	namespace {
74	void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
75	for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
76	i->print( os, indent );
77	os << std::endl;
78	}
79	}
80
81	void makeExprList( const AltList &in, std::list< Expression* > &out ) {
82	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
83	out.push_back( i->expr->clone() );
84	}
85	}
86
87	struct PruneStruct {
88	bool isAmbiguous;
89	AltList::iterator candidate;
90	PruneStruct() {}
91	PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
92	};
93
94	/// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
95	template< typename InputIterator, typename OutputIterator >
96	void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
97	// select the alternatives that have the minimum conversion cost for a particular set of result types
98	std::map< std::string, PruneStruct > selected;
99	for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
100	PruneStruct current( candidate );
101	std::string mangleName;
102	{
103	Type * newType = candidate->expr->get_result()->clone();
104	candidate->env.apply( newType );
105	mangleName = SymTab::Mangler::mangle( newType );
106	delete newType;
107	}
108	std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
109	if ( mapPlace != selected.end() ) {
110	if ( candidate->cost < mapPlace->second.candidate->cost ) {
111	PRINT(
112	std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
113	)
114	selected[ mangleName ] = current;
115	} else if ( candidate->cost == mapPlace->second.candidate->cost ) {
116	PRINT(
117	std::cerr << "marking ambiguous" << std::endl;
118	)
119	mapPlace->second.isAmbiguous = true;
120	}
121	} else {
122	selected[ mangleName ] = current;
123	}
124	}
125
126	PRINT(
127	std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
128	)
129
130	// accept the alternatives that were unambiguous
131	for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
132	if ( ! target->second.isAmbiguous ) {
133	Alternative &alt = *target->second.candidate;
134	alt.env.applyFree( alt.expr->get_result() );
135	*out++ = alt;
136	}
137	}
138	}
139
140	template< typename InputIterator >
141	void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
142	while ( begin != end ) {
143	result.simpleCombine( (*begin++).env );
144	}
145	}
146
147	void renameTypes( Expression *expr ) {
148	expr->get_result()->accept( global_renamer );
149	}
150	}
151
152	template< typename InputIterator, typename OutputIterator >
153	void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
154	while ( begin != end ) {
155	AlternativeFinder finder( indexer, env );
156	finder.findWithAdjustment( *begin );
157	// XXX either this
158	//Designators::fixDesignations( finder, (*begin++)->get_argName() );
159	// or XXX this
160	begin++;
161	PRINT(
162	std::cerr << "findSubExprs" << std::endl;
163	printAlts( finder.alternatives, std::cerr );
164	)
165	*out++ = finder;
166	}
167	}
168
169	AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
170	: indexer( indexer ), env( env ) {
171	}
172
173	void AlternativeFinder::find( Expression *expr, bool adjust, bool prune ) {
174	expr->accept( *this );
175	if ( alternatives.empty() ) {
176	throw SemanticError( "No reasonable alternatives for expression ", expr );
177	}
178	for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
179	if ( adjust ) {
180	adjustExprType( i->expr->get_result(), i->env, indexer );
181	}
182	}
183	if ( prune ) {
184	PRINT(
185	std::cerr << "alternatives before prune:" << std::endl;
186	printAlts( alternatives, std::cerr );
187	)
188	AltList::iterator oldBegin = alternatives.begin();
189	pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
190	if ( alternatives.begin() == oldBegin ) {
191	std::ostringstream stream;
192	stream << "Can't choose between alternatives for expression ";
193	expr->print( stream );
194	stream << "Alternatives are:";
195	AltList winners;
196	findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
197	printAlts( winners, stream, 8 );
198	throw SemanticError( stream.str() );
199	}
200	alternatives.erase( oldBegin, alternatives.end() );
201	PRINT(
202	std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
203	)
204	}
205
206	// Central location to handle gcc extension keyword for all expression types.
207	for ( Alternative &iter: alternatives ) {
208	iter.expr->set_extension( expr->get_extension() );
209	} // for
210	}
211
212	void AlternativeFinder::findWithAdjustment( Expression *expr, bool prune ) {
213	find( expr, true, prune );
214	}
215
216	template< typename StructOrUnionType >
217	void AlternativeFinder::addAggMembers( StructOrUnionType aggInst, Expression expr, const Cost &newCost, const TypeEnvironment & env, Expression * member ) {
218
219	// // member must be either a tuple expression or a name expr
220	// if ( NameExpr * nameExpr = dynamic_cast< NameExpr * >( memberExpr->get_member() ) ) {
221	// addAggMembers( structInst, agg->expr, agg->cost, nameExpr->get_name() );
222	// } else {
223	// TupleExpr * tupleExpr = safe_dynamic_cast< TupleExpr * >( memberExpr->get_member() );
224	// // xxx - ...
225	// assert( false );
226	// }
227	// if ( TupleExpr * tupleExpr = dynamic_cast< TupleExpr * >( memberExpr->get_member() ) ) {
228
229	// }
230	NameExpr * nameExpr = safe_dynamic_cast< NameExpr * >( member );
231	const std::string & name = nameExpr->get_name();
232	std::list< Declaration* > members;
233	aggInst->lookup( name, members );
234	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
235	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
236	alternatives.push_back( Alternative( new MemberExpr( dwt, expr->clone() ), env, newCost ) );
237	renameTypes( alternatives.back().expr );
238	} else {
239	assert( false );
240	}
241	}
242	}
243
244	void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
245	alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
246	}
247
248	Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
249	ApplicationExpr appExpr = safe_dynamic_cast< ApplicationExpr >( alt.expr );
250	PointerType pointer = safe_dynamic_cast< PointerType >( appExpr->get_function()->get_result() );
251	FunctionType function = safe_dynamic_cast< FunctionType >( pointer->get_base() );
252
253	Cost convCost( 0, 0, 0 );
254	std::list< DeclarationWithType* >& formals = function->get_parameters();
255	std::list< DeclarationWithType* >::iterator formal = formals.begin();
256	std::list< Expression* >& actuals = appExpr->get_args();
257
258	std::list< Type * > formalTypes;
259	std::list< Type * >::iterator formalType = formalTypes.end();
260
261	for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
262
263	PRINT(
264	std::cerr << "actual expression:" << std::endl;
265	(*actualExpr)->print( std::cerr, 8 );
266	std::cerr << "--- results are" << std::endl;
267	(*actualExpr)->get_result()->print( std::cerr, 8 );
268	)
269	std::list< DeclarationWithType* >::iterator startFormal = formal;
270	Cost actualCost;
271	std::list< Type * > flatActualTypes;
272	flatten( (*actualExpr)->get_result(), back_inserter( flatActualTypes ) );
273	for ( std::list< Type* >::iterator actualType = flatActualTypes.begin(); actualType != flatActualTypes.end(); ++actualType ) {
274
275
276	// tuple handling code
277	if ( formalType == formalTypes.end() ) {
278	// the type of the formal parameter may be a tuple type. To make this easier to work with,
279	// flatten the tuple type and traverse the resulting list of types, incrementing the formal
280	// iterator once its types have been extracted. Once a particular formal parameter's type has
281	// been exhausted load the next formal parameter's type.
282	if ( formal == formals.end() ) {
283	if ( function->get_isVarArgs() ) {
284	convCost += Cost( 1, 0, 0 );
285	break;
286	} else {
287	return Cost::infinity;
288	}
289	}
290	formalTypes.clear();
291	flatten( (*formal)->get_type(), back_inserter( formalTypes ) );
292	formalType = formalTypes.begin();
293	++formal;
294	}
295
296	PRINT(
297	std::cerr << std::endl << "converting ";
298	(*actualType)->print( std::cerr, 8 );
299	std::cerr << std::endl << " to ";
300	(*formal)->get_type()->print( std::cerr, 8 );
301	)
302	Cost newCost = conversionCost( actualType, formalType, indexer, alt.env );
303	PRINT(
304	std::cerr << std::endl << "cost is" << newCost << std::endl;
305	)
306
307	if ( newCost == Cost::infinity ) {
308	return newCost;
309	}
310	convCost += newCost;
311	actualCost += newCost;
312
313	convCost += Cost( 0, polyCost( formalType, alt.env, indexer ) + polyCost( actualType, alt.env, indexer ), 0 );
314
315	formalType++;
316	}
317	if ( actualCost != Cost( 0, 0, 0 ) ) {
318	std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
319	startFormalPlusOne++;
320	if ( formal == startFormalPlusOne ) {
321	// not a tuple type
322	Type newType = (startFormal)->get_type()->clone();
323	alt.env.apply( newType );
324	actualExpr = new CastExpr( actualExpr, newType );
325	} else {
326	TupleType *newType = new TupleType( Type::Qualifiers() );
327	for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
328	newType->get_types().push_back( (*i)->get_type()->clone() );
329	}
330	alt.env.apply( newType );
331	actualExpr = new CastExpr( actualExpr, newType );
332	}
333	}
334
335	}
336	if ( formal != formals.end() ) {
337	return Cost::infinity;
338	}
339
340	for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
341	PRINT(
342	std::cerr << std::endl << "converting ";
343	assert->second.actualType->print( std::cerr, 8 );
344	std::cerr << std::endl << " to ";
345	assert->second.formalType->print( std::cerr, 8 );
346	)
347	Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
348	PRINT(
349	std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
350	)
351	if ( newCost == Cost::infinity ) {
352	return newCost;
353	}
354	convCost += newCost;
355
356	convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
357	}
358
359	return convCost;
360	}
361
362	/// Adds type variables to the open variable set and marks their assertions
363	void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
364	for ( Type::ForallList::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
365	unifiableVars[ (tyvar)->get_name() ] = (tyvar)->get_kind();
366	for ( std::list< DeclarationWithType* >::iterator assert = (tyvar)->get_assertions().begin(); assert != (tyvar)->get_assertions().end(); ++assert ) {
367	needAssertions[ *assert ] = true;
368	}
369	/// needAssertions.insert( needAssertions.end(), (tyvar)->get_assertions().begin(), (tyvar)->get_assertions().end() );
370	}
371	}
372
373	/// instantiate a single argument by matching actuals from [actualIt, actualEnd) against formalType,
374	/// producing expression(s) in out and their total cost in cost.
375	template< typename AltIterator, typename OutputIterator >
376	bool instantiateArgument( Type * formalType, Initializer * defaultValue, AltIterator & actualIt, AltIterator actualEnd, OpenVarSet & openVars, TypeEnvironment & resultEnv, AssertionSet & resultNeed, AssertionSet & resultHave, const SymTab::Indexer & indexer, Cost & cost, OutputIterator out ) {
377	if ( TupleType * tupleType = dynamic_cast< TupleType * >( formalType ) ) {
378	// formalType is a TupleType - group actuals into a TupleExpr whose type unifies with the TupleType
379	TupleExpr * tupleExpr = new TupleExpr();
380	for ( Type * type : *tupleType ) {
381	if ( ! instantiateArgument( type, defaultValue, actualIt, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( tupleExpr->get_exprs() ) ) ) {
382	delete tupleExpr;
383	return false;
384	}
385	}
386	tupleExpr->set_result( Tuples::makeTupleType( tupleExpr->get_exprs() ) );
387	*out++ = tupleExpr;
388	} else if ( actualIt != actualEnd ) {
389	// both actualType and formalType are atomic (non-tuple) types - if they unify
390	// then accept actual as an argument, otherwise return false (fail to instantiate argument)
391	Expression * actual = actualIt->expr;
392	Type * actualType = actual->get_result();
393	PRINT(
394	std::cerr << "formal type is ";
395	formalType->print( std::cerr );
396	std::cerr << std::endl << "actual type is ";
397	actualType->print( std::cerr );
398	std::cerr << std::endl;
399	)
400	if ( ! unify( formalType, actualType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
401	return false;
402	}
403	// move the expression from the alternative to the output iterator
404	*out++ = actual;
405	actualIt->expr = nullptr;
406	cost += actualIt->cost;
407	++actualIt;
408	} else {
409	// End of actuals - Handle default values
410	if ( SingleInit si = dynamic_cast<SingleInit >( defaultValue )) {
411	// so far, only constant expressions are accepted as default values
412	if ( ConstantExpr cnstexpr = dynamic_cast<ConstantExpr >( si->get_value()) ) {
413	if ( Constant cnst = dynamic_cast<Constant >( cnstexpr->get_constant() ) ) {
414	if ( unify( formalType, cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
415	// xxx - Don't know if this is right
416	*out++ = cnstexpr->clone();
417	return true;
418	} // if
419	} // if
420	} // if
421	} // if
422	return false;
423	} // if
424	return true;
425	}
426
427	bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, const AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave, AltList & out ) {
428	simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
429	// make sure we don't widen any existing bindings
430	for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
431	i->allowWidening = false;
432	}
433	resultEnv.extractOpenVars( openVars );
434
435	// flatten actuals so that each actual has an atomic (non-tuple) type
436	AltList exploded;
437	explode( actuals, back_inserter( exploded ) );
438
439	AltList::iterator actualExpr = exploded.begin();
440	AltList::iterator actualEnd = exploded.end();
441	for ( DeclarationWithType * formal : formals ) {
442	// match flattened actuals with formal parameters - actuals will be grouped to match
443	// with formals as appropriate
444	Cost cost;
445	std::list< Expression * > newExprs;
446	ObjectDecl * obj = safe_dynamic_cast< ObjectDecl * >( formal );
447	if ( ! instantiateArgument( obj->get_type(), obj->get_init(), actualExpr, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( newExprs ) ) ) {
448	deleteAll( newExprs );
449	return false;
450	}
451	// success - produce argument as a new alternative
452	assert( newExprs.size() == 1 );
453	out.push_back( Alternative( newExprs.front(), resultEnv, cost ) );
454	}
455	if ( actualExpr != actualEnd ) {
456	// there are still actuals remaining, but we've run out of formal parameters to match against
457	// this is okay only if the function is variadic
458	if ( ! isVarArgs ) {
459	return false;
460	}
461	out.splice( out.end(), exploded, actualExpr, actualEnd );
462	}
463	return true;
464	}
465
466	// /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
467	//typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
468
469	static const int recursionLimit = /10/ 4; ///< Limit to depth of recursion satisfaction
470	//static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
471
472	void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
473	for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
474	if ( i->second == true ) {
475	i->first->accept( indexer );
476	}
477	}
478	}
479
480	template< typename ForwardIterator, typename OutputIterator >
481	void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /const AssertionParentSet &needParents,/
482	int level, const SymTab::Indexer &indexer, OutputIterator out ) {
483	if ( begin == end ) {
484	if ( newNeed.empty() ) {
485	*out++ = newAlt;
486	return;
487	} else if ( level >= recursionLimit ) {
488	throw SemanticError( "Too many recursive assertions" );
489	} else {
490	AssertionSet newerNeed;
491	PRINT(
492	std::cerr << "recursing with new set:" << std::endl;
493	printAssertionSet( newNeed, std::cerr, 8 );
494	)
495	inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /needParents,/ level+1, indexer, out );
496	return;
497	}
498	}
499
500	ForwardIterator cur = begin++;
501	if ( ! cur->second ) {
502	inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /needParents,/ level, indexer, out );
503	}
504	DeclarationWithType *curDecl = cur->first;
505	PRINT(
506	std::cerr << "inferRecursive: assertion is ";
507	curDecl->print( std::cerr );
508	std::cerr << std::endl;
509	)
510	std::list< DeclarationWithType* > candidates;
511	decls.lookupId( curDecl->get_name(), candidates );
512	/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
513	for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
514	PRINT(
515	std::cerr << "inferRecursive: candidate is ";
516	(*candidate)->print( std::cerr );
517	std::cerr << std::endl;
518	)
519
520	AssertionSet newHave, newerNeed( newNeed );
521	TypeEnvironment newEnv( newAlt.env );
522	OpenVarSet newOpenVars( openVars );
523	Type adjType = (candidate)->get_type()->clone();
524	adjustExprType( adjType, newEnv, indexer );
525	adjType->accept( global_renamer );
526	PRINT(
527	std::cerr << "unifying ";
528	curDecl->get_type()->print( std::cerr );
529	std::cerr << " with ";
530	adjType->print( std::cerr );
531	std::cerr << std::endl;
532	)
533	if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
534	PRINT(
535	std::cerr << "success!" << std::endl;
536	)
537	SymTab::Indexer newDecls( decls );
538	addToIndexer( newHave, newDecls );
539	Alternative newerAlt( newAlt );
540	newerAlt.env = newEnv;
541	assert( (*candidate)->get_uniqueId() );
542	DeclarationWithType candDecl = static_cast< DeclarationWithType >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
543	//AssertionParentSet newNeedParents( needParents );
544	// skip repeatingly-self-recursive assertion satisfaction
545	// DOESN'T WORK: grandchild nodes conflict with their cousins
546	//if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
547	Expression *varExpr = new VariableExpr( candDecl );
548	delete varExpr->get_result();
549	varExpr->set_result( adjType->clone() );
550	PRINT(
551	std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
552	curDecl->print( std::cerr );
553	std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
554	(*candidate)->print( std::cerr );
555	std::cerr << std::endl;
556	)
557	ApplicationExpr appExpr = static_cast< ApplicationExpr >( newerAlt.expr );
558	// XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
559	appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
560	inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /newNeedParents,/ level, indexer, out );
561	} else {
562	delete adjType;
563	}
564	}
565	}
566
567	template< typename OutputIterator >
568	void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
569	// PRINT(
570	// std::cerr << "inferParameters: assertions needed are" << std::endl;
571	// printAll( need, std::cerr, 8 );
572	// )
573	SymTab::Indexer decls( indexer );
574	PRINT(
575	std::cerr << "============= original indexer" << std::endl;
576	indexer.print( std::cerr );
577	std::cerr << "============= new indexer" << std::endl;
578	decls.print( std::cerr );
579	)
580	addToIndexer( have, decls );
581	AssertionSet newNeed;
582	//AssertionParentSet needParents;
583	inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /needParents,/ 0, indexer, out );
584	// PRINT(
585	// std::cerr << "declaration 14 is ";
586	// Declaration::declFromId
587	// *out++ = newAlt;
588	// )
589	}
590
591	template< typename OutputIterator >
592	void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, const AltList &actualAlt, OutputIterator out ) {
593	OpenVarSet openVars;
594	AssertionSet resultNeed, resultHave;
595	TypeEnvironment resultEnv;
596	makeUnifiableVars( funcType, openVars, resultNeed );
597	AltList instantiatedActuals; // filled by instantiate function
598	if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave, instantiatedActuals ) ) {
599	ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
600	Alternative newAlt( appExpr, resultEnv, sumCost( instantiatedActuals ) );
601	makeExprList( instantiatedActuals, appExpr->get_args() );
602	PRINT(
603	std::cerr << "need assertions:" << std::endl;
604	printAssertionSet( resultNeed, std::cerr, 8 );
605	)
606	inferParameters( resultNeed, resultHave, newAlt, openVars, out );
607	}
608	}
609
610	void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
611	bool doneInit = false;
612	AlternativeFinder funcOpFinder( indexer, env );
613
614	AlternativeFinder funcFinder( indexer, env );
615
616	{
617	std::string fname = InitTweak::getFunctionName( untypedExpr );
618	if ( fname == "&&" ) {
619	VoidType v = Type::Qualifiers(); // resolve to type void *
620	PointerType pt( Type::Qualifiers(), v.clone() );
621	UntypedExpr *vexpr = untypedExpr->clone();
622	vexpr->set_result( pt.clone() );
623	alternatives.push_back( Alternative( vexpr, env, Cost()) );
624	return;
625	}
626	}
627
628	funcFinder.findWithAdjustment( untypedExpr->get_function() );
629	std::list< AlternativeFinder > argAlternatives;
630	findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
631
632	std::list< AltList > possibilities;
633	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
634
635	// take care of possible tuple assignments
636	// if not tuple assignment, assignment is taken care of as a normal function call
637	Tuples::handleTupleAssignment( *this, untypedExpr, possibilities );
638
639	AltList candidates;
640	SemanticError errors;
641
642	for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
643	try {
644	PRINT(
645	std::cerr << "working on alternative: " << std::endl;
646	func->print( std::cerr, 8 );
647	)
648	// check if the type is pointer to function
649	PointerType *pointer;
650	if ( ( pointer = dynamic_cast< PointerType* >( func->expr->get_result() ) ) ) {
651	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
652	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
653	// XXX
654	//Designators::check_alternative( function, *actualAlt );
655	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
656	}
657	} else if ( TypeInstType typeInst = dynamic_cast< TypeInstType >( pointer->get_base() ) ) {
658	EqvClass eqvClass;
659	if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
660	if ( FunctionType function = dynamic_cast< FunctionType >( eqvClass.type ) ) {
661	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
662	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
663	} // for
664	} // if
665	} // if
666	} // if
667	} else {
668	// seek a function operator that's compatible
669	if ( ! doneInit ) {
670	doneInit = true;
671	NameExpr *opExpr = new NameExpr( "?()" );
672	try {
673	funcOpFinder.findWithAdjustment( opExpr );
674	} catch( SemanticError &e ) {
675	// it's ok if there aren't any defined function ops
676	}
677	PRINT(
678	std::cerr << "known function ops:" << std::endl;
679	printAlts( funcOpFinder.alternatives, std::cerr, 8 );
680	)
681	}
682
683	for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
684	// check if the type is pointer to function
685	PointerType *pointer;
686	if ( ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_result() ) ) ) {
687	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
688	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
689	AltList currentAlt;
690	currentAlt.push_back( *func );
691	currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
692	makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
693	} // for
694	} // if
695	} // if
696	} // for
697	} // if
698	} catch ( SemanticError &e ) {
699	errors.append( e );
700	}
701	} // for
702
703	// Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
704	if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
705
706	for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
707	Cost cvtCost = computeConversionCost( *withFunc, indexer );
708
709	PRINT(
710	ApplicationExpr appExpr = safe_dynamic_cast< ApplicationExpr >( withFunc->expr );
711	PointerType pointer = safe_dynamic_cast< PointerType >( appExpr->get_function()->get_result() );
712	FunctionType function = safe_dynamic_cast< FunctionType >( pointer->get_base() );
713	std::cerr << "Case +++++++++++++" << std::endl;
714	std::cerr << "formals are:" << std::endl;
715	printAll( function->get_parameters(), std::cerr, 8 );
716	std::cerr << "actuals are:" << std::endl;
717	printAll( appExpr->get_args(), std::cerr, 8 );
718	std::cerr << "bindings are:" << std::endl;
719	withFunc->env.print( std::cerr, 8 );
720	std::cerr << "cost of conversion is:" << cvtCost << std::endl;
721	)
722	if ( cvtCost != Cost::infinity ) {
723	withFunc->cvtCost = cvtCost;
724	alternatives.push_back( *withFunc );
725	} // if
726	} // for
727	candidates.clear();
728	candidates.splice( candidates.end(), alternatives );
729
730	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
731	}
732
733	bool isLvalue( Expression *expr ) {
734	// xxx - recurse into tuples?
735	return expr->has_result() && expr->get_result()->get_isLvalue();
736	}
737
738	void AlternativeFinder::visit( AddressExpr *addressExpr ) {
739	AlternativeFinder finder( indexer, env );
740	finder.find( addressExpr->get_arg() );
741	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
742	if ( isLvalue( i->expr ) ) {
743	alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
744	} // if
745	} // for
746	}
747
748	void AlternativeFinder::visit( CastExpr *castExpr ) {
749	Type *& toType = castExpr->get_result();
750	toType = resolveTypeof( toType, indexer );
751	SymTab::validateType( toType, &indexer );
752	adjustExprType( toType, env, indexer );
753
754	AlternativeFinder finder( indexer, env );
755	finder.findWithAdjustment( castExpr->get_arg() );
756
757	AltList candidates;
758	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
759	AssertionSet needAssertions, haveAssertions;
760	OpenVarSet openVars;
761
762	// It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
763	// cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
764	// that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
765	// to.
766	int discardedValues = (*i).expr->get_result()->size() - castExpr->get_result()->size();
767	if ( discardedValues < 0 ) continue;
768	// xxx - may need to go into tuple types and extract relavent types and use unifyList
769	// unification run for side-effects
770	unify( castExpr->get_result(), (*i).expr->get_result(), i->env, needAssertions, haveAssertions, openVars, indexer );
771	Cost thisCost = castCost( (*i).expr->get_result(), castExpr->get_result(), indexer, i->env );
772	if ( thisCost != Cost::infinity ) {
773	// count one safe conversion for each value that is thrown away
774	thisCost += Cost( 0, 0, discardedValues );
775	CastExpr *newExpr = castExpr->clone();
776	newExpr->set_arg( i->expr->clone() );
777	candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
778	} // if
779	} // for
780
781	// findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
782	// cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
783	// selects first based on argument cost, then on conversion cost.
784	AltList minArgCost;
785	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
786	findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
787	}
788
789	void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
790	AlternativeFinder funcFinder( indexer, env );
791	funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
792
793	for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
794	if ( StructInstType structInst = dynamic_cast< StructInstType >( agg->expr->get_result() ) ) {
795	addAggMembers( structInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
796	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( agg->expr->get_result() ) ) {
797	addAggMembers( unionInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
798	} // if
799	} // for
800	}
801
802	void AlternativeFinder::visit( MemberExpr *memberExpr ) {
803	alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
804	}
805
806	void AlternativeFinder::visit( NameExpr *nameExpr ) {
807	std::list< DeclarationWithType* > declList;
808	indexer.lookupId( nameExpr->get_name(), declList );
809	PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
810	for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
811	VariableExpr newExpr( *i, nameExpr->get_argName() );
812	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
813	PRINT(
814	std::cerr << "decl is ";
815	(*i)->print( std::cerr );
816	std::cerr << std::endl;
817	std::cerr << "newExpr is ";
818	newExpr.print( std::cerr );
819	std::cerr << std::endl;
820	)
821	renameTypes( alternatives.back().expr );
822	if ( StructInstType structInst = dynamic_cast< StructInstType >( (*i)->get_type() ) ) {
823	NameExpr nameExpr( "" );
824	addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
825	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( (*i)->get_type() ) ) {
826	NameExpr nameExpr( "" );
827	addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
828	} // if
829	} // for
830	}
831
832	void AlternativeFinder::visit( VariableExpr *variableExpr ) {
833	// not sufficient to clone here, because variable's type may have changed
834	// since the VariableExpr was originally created.
835	alternatives.push_back( Alternative( new VariableExpr( variableExpr->get_var() ), env, Cost::zero ) );
836	}
837
838	void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
839	alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
840	}
841
842	void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
843	if ( sizeofExpr->get_isType() ) {
844	// xxx - resolveTypeof?
845	alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
846	} else {
847	// find all alternatives for the argument to sizeof
848	AlternativeFinder finder( indexer, env );
849	finder.find( sizeofExpr->get_expr() );
850	// find the lowest cost alternative among the alternatives, otherwise ambiguous
851	AltList winners;
852	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
853	if ( winners.size() != 1 ) {
854	throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
855	} // if
856	// return the lowest cost alternative for the argument
857	Alternative &choice = winners.front();
858	alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
859	} // if
860	}
861
862	void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
863	if ( alignofExpr->get_isType() ) {
864	// xxx - resolveTypeof?
865	alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
866	} else {
867	// find all alternatives for the argument to sizeof
868	AlternativeFinder finder( indexer, env );
869	finder.find( alignofExpr->get_expr() );
870	// find the lowest cost alternative among the alternatives, otherwise ambiguous
871	AltList winners;
872	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
873	if ( winners.size() != 1 ) {
874	throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
875	} // if
876	// return the lowest cost alternative for the argument
877	Alternative &choice = winners.front();
878	alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
879	} // if
880	}
881
882	template< typename StructOrUnionType >
883	void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
884	std::list< Declaration* > members;
885	aggInst->lookup( name, members );
886	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
887	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
888	alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt ), env, Cost::zero ) );
889	renameTypes( alternatives.back().expr );
890	} else {
891	assert( false );
892	}
893	}
894	}
895
896	void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
897	AlternativeFinder funcFinder( indexer, env );
898	// xxx - resolveTypeof?
899	if ( StructInstType structInst = dynamic_cast< StructInstType >( offsetofExpr->get_type() ) ) {
900	addOffsetof( structInst, offsetofExpr->get_member() );
901	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( offsetofExpr->get_type() ) ) {
902	addOffsetof( unionInst, offsetofExpr->get_member() );
903	}
904	}
905
906	void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
907	alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
908	}
909
910	void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
911	alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
912	}
913
914	void AlternativeFinder::resolveAttr( DeclarationWithType funcDecl, FunctionType function, Type *argType, const TypeEnvironment &env ) {
915	// assume no polymorphism
916	// assume no implicit conversions
917	assert( function->get_parameters().size() == 1 );
918	PRINT(
919	std::cerr << "resolvAttr: funcDecl is ";
920	funcDecl->print( std::cerr );
921	std::cerr << " argType is ";
922	argType->print( std::cerr );
923	std::cerr << std::endl;
924	)
925	if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
926	alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
927	for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
928	alternatives.back().expr->set_result( (*i)->get_type()->clone() );
929	} // for
930	} // if
931	}
932
933	void AlternativeFinder::visit( AttrExpr *attrExpr ) {
934	// assume no 'pointer-to-attribute'
935	NameExpr nameExpr = dynamic_cast< NameExpr >( attrExpr->get_attr() );
936	assert( nameExpr );
937	std::list< DeclarationWithType* > attrList;
938	indexer.lookupId( nameExpr->get_name(), attrList );
939	if ( attrExpr->get_isType() \|\| attrExpr->get_expr() ) {
940	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
941	// check if the type is function
942	if ( FunctionType function = dynamic_cast< FunctionType >( (*i)->get_type() ) ) {
943	// assume exactly one parameter
944	if ( function->get_parameters().size() == 1 ) {
945	if ( attrExpr->get_isType() ) {
946	resolveAttr( *i, function, attrExpr->get_type(), env );
947	} else {
948	AlternativeFinder finder( indexer, env );
949	finder.find( attrExpr->get_expr() );
950	for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
951	if ( choice->expr->get_result()->size() == 1 ) {
952	resolveAttr(*i, function, choice->expr->get_result(), choice->env );
953	} // fi
954	} // for
955	} // if
956	} // if
957	} // if
958	} // for
959	} else {
960	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
961	VariableExpr newExpr( *i );
962	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
963	renameTypes( alternatives.back().expr );
964	} // for
965	} // if
966	}
967
968	void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
969	AlternativeFinder firstFinder( indexer, env );
970	firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
971	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
972	AlternativeFinder secondFinder( indexer, first->env );
973	secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
974	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
975	LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
976	alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
977	}
978	}
979	}
980
981	void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
982	AlternativeFinder firstFinder( indexer, env );
983	firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
984	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
985	AlternativeFinder secondFinder( indexer, first->env );
986	secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
987	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
988	AlternativeFinder thirdFinder( indexer, second->env );
989	thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
990	for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
991	OpenVarSet openVars;
992	AssertionSet needAssertions, haveAssertions;
993	Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
994	Type* commonType;
995	if ( unify( second->expr->get_result(), third->expr->get_result(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
996	ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
997	newExpr->set_result( commonType ? commonType : second->expr->get_result()->clone() );
998	newAlt.expr = newExpr;
999	inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
1000	} // if
1001	} // for
1002	} // for
1003	} // for
1004	}
1005
1006	void AlternativeFinder::visit( CommaExpr *commaExpr ) {
1007	TypeEnvironment newEnv( env );
1008	Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
1009	AlternativeFinder secondFinder( indexer, newEnv );
1010	secondFinder.findWithAdjustment( commaExpr->get_arg2() );
1011	for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
1012	alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
1013	} // for
1014	delete newFirstArg;
1015	}
1016
1017	void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
1018	std::list< AlternativeFinder > subExprAlternatives;
1019	findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
1020	std::list< AltList > possibilities;
1021	combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
1022	for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
1023	TupleExpr *newExpr = new TupleExpr;
1024	makeExprList( *i, newExpr->get_exprs() );
1025	newExpr->set_result( Tuples::makeTupleType( newExpr->get_exprs() ) );
1026
1027	TypeEnvironment compositeEnv;
1028	simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1029	alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1030	} // for
1031	}
1032
1033	void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1034	alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1035	}
1036
1037	void AlternativeFinder::visit( ConstructorExpr * ctorExpr ) {
1038	AlternativeFinder finder( indexer, env );
1039	// don't prune here, since it's guaranteed all alternatives will have the same type
1040	// (giving the alternatives different types is half of the point of ConstructorExpr nodes)
1041	finder.findWithAdjustment( ctorExpr->get_callExpr(), false );
1042	for ( Alternative & alt : finder.alternatives ) {
1043	alternatives.push_back( Alternative( new ConstructorExpr( alt.expr->clone() ), alt.env, alt.cost ) );
1044	}
1045	}
1046
1047	void AlternativeFinder::visit( TupleIndexExpr *tupleExpr ) {
1048	alternatives.push_back( Alternative( tupleExpr->clone(), env, Cost::zero ) );
1049	}
1050
1051	void AlternativeFinder::visit( TupleAssignExpr *tupleAssignExpr ) {
1052	alternatives.push_back( Alternative( tupleAssignExpr->clone(), env, Cost::zero ) );
1053	}
1054	} // namespace ResolvExpr
1055
1056	// Local Variables: //
1057	// tab-width: 4 //
1058	// mode: c++ //
1059	// compile-command: "make install" //
1060	// End: //

Note: See TracBrowser for help on using the repository browser.

Download in other formats: