source: src/ResolvExpr/AlternativeFinder.cc@ 1ced874

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since 1ced874 was 1ced874, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

Merge branch 'master' into tuples
  • Property mode set to 100644
File size: 43.6 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/TupleAssignment.h"
41#include "Tuples/NameMatcher.h"
42#include "Common/utility.h"
43#include "InitTweak/InitTweak.h"
44#include "ResolveTypeof.h"
45
46extern bool resolvep;
47#define PRINT( text ) if ( resolvep ) { text }
48//#define DEBUG_COST
49
50namespace ResolvExpr {
51 Expression *resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
52 CastExpr *castToVoid = new CastExpr( expr );
53
54 AlternativeFinder finder( indexer, env );
55 finder.findWithAdjustment( castToVoid );
56
57 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
58 // interpretations, an exception has already been thrown.
59 assert( finder.get_alternatives().size() == 1 );
60 CastExpr *newExpr = dynamic_cast< CastExpr* >( finder.get_alternatives().front().expr );
61 assert( newExpr );
62 env = finder.get_alternatives().front().env;
63 return newExpr->get_arg()->clone();
64 }
65
66 namespace {
67 void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
68 for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
69 i->print( os, indent );
70 os << std::endl;
71 }
72 }
73
74 void makeExprList( const AltList &in, std::list< Expression* > &out ) {
75 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
76 out.push_back( i->expr->clone() );
77 }
78 }
79
80 Cost sumCost( const AltList &in ) {
81 Cost total;
82 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
83 total += i->cost;
84 }
85 return total;
86 }
87
88 struct PruneStruct {
89 bool isAmbiguous;
90 AltList::iterator candidate;
91 PruneStruct() {}
92 PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
93 };
94
95 /// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
96 template< typename InputIterator, typename OutputIterator >
97 void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
98 // select the alternatives that have the minimum conversion cost for a particular set of result types
99 std::map< std::string, PruneStruct > selected;
100 for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
101 PruneStruct current( candidate );
102 std::string mangleName;
103 for ( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
104 Type *newType = (*retType)->clone();
105 candidate->env.apply( newType );
106 mangleName += SymTab::Mangler::mangle( newType );
107 delete newType;
108 }
109 std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
110 if ( mapPlace != selected.end() ) {
111 if ( candidate->cost < mapPlace->second.candidate->cost ) {
112 PRINT(
113 std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
114 )
115 selected[ mangleName ] = current;
116 } else if ( candidate->cost == mapPlace->second.candidate->cost ) {
117 PRINT(
118 std::cerr << "marking ambiguous" << std::endl;
119 )
120 mapPlace->second.isAmbiguous = true;
121 }
122 } else {
123 selected[ mangleName ] = current;
124 }
125 }
126
127 PRINT(
128 std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
129 )
130
131 // accept the alternatives that were unambiguous
132 for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
133 if ( ! target->second.isAmbiguous ) {
134 Alternative &alt = *target->second.candidate;
135 for ( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
136 alt.env.applyFree( *result );
137 }
138 *out++ = alt;
139 }
140 }
141
142 }
143
144 template< typename InputIterator, typename OutputIterator >
145 void findMinCost( InputIterator begin, InputIterator end, OutputIterator out ) {
146 AltList alternatives;
147
148 // select the alternatives that have the minimum parameter cost
149 Cost minCost = Cost::infinity;
150 for ( AltList::iterator i = begin; i != end; ++i ) {
151 if ( i->cost < minCost ) {
152 minCost = i->cost;
153 i->cost = i->cvtCost;
154 alternatives.clear();
155 alternatives.push_back( *i );
156 } else if ( i->cost == minCost ) {
157 i->cost = i->cvtCost;
158 alternatives.push_back( *i );
159 }
160 }
161 std::copy( alternatives.begin(), alternatives.end(), out );
162 }
163
164 template< typename InputIterator >
165 void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
166 while ( begin != end ) {
167 result.simpleCombine( (*begin++).env );
168 }
169 }
170
171 void renameTypes( Expression *expr ) {
172 for ( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
173 (*i)->accept( global_renamer );
174 }
175 }
176 }
177
178 template< typename InputIterator, typename OutputIterator >
179 void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
180 while ( begin != end ) {
181 AlternativeFinder finder( indexer, env );
182 finder.findWithAdjustment( *begin );
183 // XXX either this
184 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
185 // or XXX this
186 begin++;
187 PRINT(
188 std::cerr << "findSubExprs" << std::endl;
189 printAlts( finder.alternatives, std::cerr );
190 )
191 *out++ = finder;
192 }
193 }
194
195 AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
196 : indexer( indexer ), env( env ) {
197 }
198
199 void AlternativeFinder::find( Expression *expr, bool adjust ) {
200 expr->accept( *this );
201 if ( alternatives.empty() ) {
202 throw SemanticError( "No reasonable alternatives for expression ", expr );
203 }
204 for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
205 if ( adjust ) {
206 adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
207 }
208 }
209 PRINT(
210 std::cerr << "alternatives before prune:" << std::endl;
211 printAlts( alternatives, std::cerr );
212 )
213 AltList::iterator oldBegin = alternatives.begin();
214 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
215 if ( alternatives.begin() == oldBegin ) {
216 std::ostringstream stream;
217 stream << "Can't choose between alternatives for expression ";
218 expr->print( stream );
219 stream << "Alternatives are:";
220 AltList winners;
221 findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
222 printAlts( winners, stream, 8 );
223 throw SemanticError( stream.str() );
224 }
225 alternatives.erase( oldBegin, alternatives.end() );
226 PRINT(
227 std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
228 )
229
230 // Central location to handle gcc extension keyword for all expression types.
231 for ( Alternative &iter: alternatives ) {
232 iter.expr->set_extension( expr->get_extension() );
233 } // for
234 }
235
236 void AlternativeFinder::findWithAdjustment( Expression *expr ) {
237 find( expr, true );
238 }
239
240 template< typename StructOrUnionType >
241 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const std::string &name ) {
242 std::list< Declaration* > members;
243 aggInst->lookup( name, members );
244 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
245 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
246 alternatives.push_back( Alternative( new MemberExpr( dwt, expr->clone() ), env, newCost ) );
247 renameTypes( alternatives.back().expr );
248 } else {
249 assert( false );
250 }
251 }
252 }
253
254 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
255 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
256 }
257
258 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
259 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( alt.expr );
260 assert( appExpr );
261 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
262 assert( pointer );
263 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
264 assert( function );
265
266 Cost convCost( 0, 0, 0 );
267 std::list< DeclarationWithType* >& formals = function->get_parameters();
268 std::list< DeclarationWithType* >::iterator formal = formals.begin();
269 std::list< Expression* >& actuals = appExpr->get_args();
270
271 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
272 PRINT(
273 std::cerr << "actual expression:" << std::endl;
274 (*actualExpr)->print( std::cerr, 8 );
275 std::cerr << "--- results are" << std::endl;
276 printAll( (*actualExpr)->get_results(), std::cerr, 8 );
277 )
278 std::list< DeclarationWithType* >::iterator startFormal = formal;
279 Cost actualCost;
280 for ( std::list< Type* >::iterator actualType = (*actualExpr)->get_results().begin(); actualType != (*actualExpr)->get_results().end(); ++actualType ) {
281 // xxx - need tuple handling code here
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 PRINT(
291 std::cerr << std::endl << "converting ";
292 (*actualType)->print( std::cerr, 8 );
293 std::cerr << std::endl << " to ";
294 (*formal)->get_type()->print( std::cerr, 8 );
295 )
296 Cost newCost = conversionCost( *actualType, (*formal)->get_type(), indexer, alt.env );
297 PRINT(
298 std::cerr << std::endl << "cost is" << newCost << std::endl;
299 )
300
301 if ( newCost == Cost::infinity ) {
302 return newCost;
303 }
304 convCost += newCost;
305 actualCost += newCost;
306
307 convCost += Cost( 0, polyCost( (*formal)->get_type(), alt.env, indexer ) + polyCost( *actualType, alt.env, indexer ), 0 );
308
309 formal++;
310 }
311 if ( actualCost != Cost( 0, 0, 0 ) ) {
312 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
313 startFormalPlusOne++;
314 if ( formal == startFormalPlusOne ) {
315 // not a tuple type
316 Type *newType = (*startFormal)->get_type()->clone();
317 alt.env.apply( newType );
318 *actualExpr = new CastExpr( *actualExpr, newType );
319 } else {
320 TupleType *newType = new TupleType( Type::Qualifiers() );
321 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
322 newType->get_types().push_back( (*i)->get_type()->clone() );
323 }
324 alt.env.apply( newType );
325 *actualExpr = new CastExpr( *actualExpr, newType );
326 }
327 }
328
329 }
330 if ( formal != formals.end() ) {
331 return Cost::infinity;
332 }
333
334 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
335 PRINT(
336 std::cerr << std::endl << "converting ";
337 assert->second.actualType->print( std::cerr, 8 );
338 std::cerr << std::endl << " to ";
339 assert->second.formalType->print( std::cerr, 8 );
340 )
341 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
342 PRINT(
343 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
344 )
345 if ( newCost == Cost::infinity ) {
346 return newCost;
347 }
348 convCost += newCost;
349
350 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
351 }
352
353 return convCost;
354 }
355
356 /// Adds type variables to the open variable set and marks their assertions
357 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
358 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
359 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
360 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
361 needAssertions[ *assert ] = true;
362 }
363/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
364 }
365 }
366
367 template< typename OutputIterator >
368 void flatten( Type * type, OutputIterator out ) {
369 if ( TupleType * tupleType = dynamic_cast< TupleType * >( type ) ) {
370 for ( Type * t : *tupleType ) {
371 flatten( t, out );
372 }
373 } else {
374 *out++ = type;
375 }
376 }
377
378 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
379 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
380 // make sure we don't widen any existing bindings
381 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
382 i->allowWidening = false;
383 }
384 resultEnv.extractOpenVars( openVars );
385
386 /*
387 Tuples::NameMatcher matcher( formals );
388 try {
389 matcher.match( actuals );
390 } catch ( Tuples::NoMatch &e ) {
391 std::cerr << "Alternative doesn't match: " << e.message << std::endl;
392 }
393 */
394 std::list< DeclarationWithType* >::iterator formal = formals.begin();
395
396 std::list< Type * > formalTypes;
397 std::list< Type * >::iterator formalType = formalTypes.end();
398
399 for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
400 std::list< Type* > & actualTypes = actualExpr->expr->get_results();
401 for ( std::list< Type* >::iterator actualType = actualTypes.begin(); actualType != actualTypes.end(); ++actualType ) {
402 if ( formalType == formalTypes.end() ) {
403 // the type of the formal parameter may be a tuple type. To make this easier to work with,
404 // flatten the tuple type and traverse the resulting list of types, incrementing the formal
405 // iterator once its types have been extracted. Once a particular formal parameter's type has
406 // been exhausted load the next formal parameter's type.
407 if ( formal == formals.end() ) {
408 return isVarArgs;
409 }
410 formalTypes.clear();
411 flatten( (*formal)->get_type(), back_inserter( formalTypes ) );
412 formalType = formalTypes.begin();
413 ++formal;
414 }
415 PRINT(
416 std::cerr << "formal type is ";
417 (*formal)->get_type()->print( std::cerr );
418 std::cerr << std::endl << "actual type is ";
419 (*actualType)->print( std::cerr );
420 std::cerr << std::endl;
421 )
422 if ( ! unify( *formalType, *actualType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
423 return false;
424 }
425 ++formalType;
426 }
427 }
428
429 // xxx - a tuple type was not completely matched
430 // partially handle the tuple with default arguments??
431 if ( formalType != formalTypes.end() ) return false;
432
433 // Handling of default values
434 while ( formal != formals.end() ) {
435 if ( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
436 if ( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
437 // so far, only constant expressions are accepted as default values
438 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) )
439 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
440 if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
441 // XXX Don't know if this is right
442 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
443 formal++;
444 if ( formal == formals.end()) break;
445 }
446 return false;
447 }
448 return true;
449 }
450
451 // /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
452 //typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
453
454 static const int recursionLimit = /*10*/ 4; ///< Limit to depth of recursion satisfaction
455 //static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
456
457 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
458 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
459 if ( i->second == true ) {
460 i->first->accept( indexer );
461 }
462 }
463 }
464
465 template< typename ForwardIterator, typename OutputIterator >
466 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /*const AssertionParentSet &needParents,*/
467 int level, const SymTab::Indexer &indexer, OutputIterator out ) {
468 if ( begin == end ) {
469 if ( newNeed.empty() ) {
470 *out++ = newAlt;
471 return;
472 } else if ( level >= recursionLimit ) {
473 throw SemanticError( "Too many recursive assertions" );
474 } else {
475 AssertionSet newerNeed;
476 PRINT(
477 std::cerr << "recursing with new set:" << std::endl;
478 printAssertionSet( newNeed, std::cerr, 8 );
479 )
480 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /*needParents,*/ level+1, indexer, out );
481 return;
482 }
483 }
484
485 ForwardIterator cur = begin++;
486 if ( ! cur->second ) {
487 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /*needParents,*/ level, indexer, out );
488 }
489 DeclarationWithType *curDecl = cur->first;
490 PRINT(
491 std::cerr << "inferRecursive: assertion is ";
492 curDecl->print( std::cerr );
493 std::cerr << std::endl;
494 )
495 std::list< DeclarationWithType* > candidates;
496 decls.lookupId( curDecl->get_name(), candidates );
497/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
498 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
499 PRINT(
500 std::cerr << "inferRecursive: candidate is ";
501 (*candidate)->print( std::cerr );
502 std::cerr << std::endl;
503 )
504
505 AssertionSet newHave, newerNeed( newNeed );
506 TypeEnvironment newEnv( newAlt.env );
507 OpenVarSet newOpenVars( openVars );
508 Type *adjType = (*candidate)->get_type()->clone();
509 adjustExprType( adjType, newEnv, indexer );
510 adjType->accept( global_renamer );
511 PRINT(
512 std::cerr << "unifying ";
513 curDecl->get_type()->print( std::cerr );
514 std::cerr << " with ";
515 adjType->print( std::cerr );
516 std::cerr << std::endl;
517 )
518 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
519 PRINT(
520 std::cerr << "success!" << std::endl;
521 )
522 SymTab::Indexer newDecls( decls );
523 addToIndexer( newHave, newDecls );
524 Alternative newerAlt( newAlt );
525 newerAlt.env = newEnv;
526 assert( (*candidate)->get_uniqueId() );
527 DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
528 //AssertionParentSet newNeedParents( needParents );
529 // skip repeatingly-self-recursive assertion satisfaction
530 // DOESN'T WORK: grandchild nodes conflict with their cousins
531 //if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
532 Expression *varExpr = new VariableExpr( candDecl );
533 deleteAll( varExpr->get_results() );
534 varExpr->get_results().clear();
535 varExpr->get_results().push_front( adjType->clone() );
536 PRINT(
537 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
538 curDecl->print( std::cerr );
539 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
540 (*candidate)->print( std::cerr );
541 std::cerr << std::endl;
542 )
543 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
544 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
545 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
546 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /*newNeedParents,*/ level, indexer, out );
547 } else {
548 delete adjType;
549 }
550 }
551 }
552
553 template< typename OutputIterator >
554 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
555// PRINT(
556// std::cerr << "inferParameters: assertions needed are" << std::endl;
557// printAll( need, std::cerr, 8 );
558// )
559 SymTab::Indexer decls( indexer );
560 PRINT(
561 std::cerr << "============= original indexer" << std::endl;
562 indexer.print( std::cerr );
563 std::cerr << "============= new indexer" << std::endl;
564 decls.print( std::cerr );
565 )
566 addToIndexer( have, decls );
567 AssertionSet newNeed;
568 //AssertionParentSet needParents;
569 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /*needParents,*/ 0, indexer, out );
570// PRINT(
571// std::cerr << "declaration 14 is ";
572// Declaration::declFromId
573// *out++ = newAlt;
574// )
575 }
576
577 template< typename OutputIterator >
578 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
579 OpenVarSet openVars;
580 AssertionSet resultNeed, resultHave;
581 TypeEnvironment resultEnv;
582 makeUnifiableVars( funcType, openVars, resultNeed );
583 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
584 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
585 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
586 makeExprList( actualAlt, appExpr->get_args() );
587 PRINT(
588 std::cerr << "need assertions:" << std::endl;
589 printAssertionSet( resultNeed, std::cerr, 8 );
590 )
591 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
592 }
593 }
594
595 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
596 bool doneInit = false;
597 AlternativeFinder funcOpFinder( indexer, env );
598
599 AlternativeFinder funcFinder( indexer, env );
600
601 {
602 std::string fname = InitTweak::getFunctionName( untypedExpr );
603 if ( fname == "&&" ) {
604 VoidType v = Type::Qualifiers(); // resolve to type void *
605 PointerType pt( Type::Qualifiers(), v.clone() );
606 UntypedExpr *vexpr = untypedExpr->clone();
607 vexpr->get_results().push_front( pt.clone() );
608 alternatives.push_back( Alternative( vexpr, env, Cost()) );
609 return;
610 }
611 }
612
613 funcFinder.findWithAdjustment( untypedExpr->get_function() );
614 std::list< AlternativeFinder > argAlternatives;
615 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
616
617 std::list< AltList > possibilities;
618 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
619
620 Tuples::TupleAssignSpotter tassign( this );
621 if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
622 // take care of possible tuple assignments, or discard expression
623 return;
624 } // else ...
625
626 AltList candidates;
627 SemanticError errors;
628
629 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
630 try {
631 PRINT(
632 std::cerr << "working on alternative: " << std::endl;
633 func->print( std::cerr, 8 );
634 )
635 // check if the type is pointer to function
636 PointerType *pointer;
637 if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
638 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
639 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
640 // XXX
641 //Designators::check_alternative( function, *actualAlt );
642 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
643 }
644 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
645 EqvClass eqvClass;
646 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
647 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
648 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
649 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
650 } // for
651 } // if
652 } // if
653 } // if
654 } else {
655 // seek a function operator that's compatible
656 if ( ! doneInit ) {
657 doneInit = true;
658 NameExpr *opExpr = new NameExpr( "?()" );
659 try {
660 funcOpFinder.findWithAdjustment( opExpr );
661 } catch( SemanticError &e ) {
662 // it's ok if there aren't any defined function ops
663 }
664 PRINT(
665 std::cerr << "known function ops:" << std::endl;
666 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
667 )
668 }
669
670 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
671 // check if the type is pointer to function
672 PointerType *pointer;
673 if ( funcOp->expr->get_results().size() == 1
674 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
675 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
676 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
677 AltList currentAlt;
678 currentAlt.push_back( *func );
679 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
680 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
681 } // for
682 } // if
683 } // if
684 } // for
685 } // if
686 } catch ( SemanticError &e ) {
687 errors.append( e );
688 }
689 } // for
690
691 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
692 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
693
694 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
695 Cost cvtCost = computeConversionCost( *withFunc, indexer );
696
697 PRINT(
698 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
699 assert( appExpr );
700 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
701 assert( pointer );
702 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
703 assert( function );
704 std::cerr << "Case +++++++++++++" << std::endl;
705 std::cerr << "formals are:" << std::endl;
706 printAll( function->get_parameters(), std::cerr, 8 );
707 std::cerr << "actuals are:" << std::endl;
708 printAll( appExpr->get_args(), std::cerr, 8 );
709 std::cerr << "bindings are:" << std::endl;
710 withFunc->env.print( std::cerr, 8 );
711 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
712 )
713 if ( cvtCost != Cost::infinity ) {
714 withFunc->cvtCost = cvtCost;
715 alternatives.push_back( *withFunc );
716 } // if
717 } // for
718 candidates.clear();
719 candidates.splice( candidates.end(), alternatives );
720
721 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
722 }
723
724 bool isLvalue( Expression *expr ) {
725 for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
726 if ( !(*i)->get_isLvalue() ) return false;
727 } // for
728 return true;
729 }
730
731 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
732 AlternativeFinder finder( indexer, env );
733 finder.find( addressExpr->get_arg() );
734 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
735 if ( isLvalue( i->expr ) ) {
736 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
737 } // if
738 } // for
739 }
740
741 void AlternativeFinder::visit( CastExpr *castExpr ) {
742 for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
743 *i = resolveTypeof( *i, indexer );
744 SymTab::validateType( *i, &indexer );
745 adjustExprType( *i, env, indexer );
746 } // for
747
748 AlternativeFinder finder( indexer, env );
749 finder.findWithAdjustment( castExpr->get_arg() );
750
751 AltList candidates;
752 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
753 AssertionSet needAssertions, haveAssertions;
754 OpenVarSet openVars;
755
756 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
757 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
758 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
759 // to.
760 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
761 if ( discardedValues < 0 ) continue;
762 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
763 std::advance( candidate_end, castExpr->get_results().size() );
764 // unification run for side-effects
765 unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
766 (*i).expr->get_results().begin(), candidate_end,
767 i->env, needAssertions, haveAssertions, openVars, indexer );
768 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
769 castExpr->get_results().begin(), castExpr->get_results().end(),
770 indexer, i->env );
771 if ( thisCost != Cost::infinity ) {
772 // count one safe conversion for each value that is thrown away
773 thisCost += Cost( 0, 0, discardedValues );
774 CastExpr *newExpr = castExpr->clone();
775 newExpr->set_arg( i->expr->clone() );
776 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
777 } // if
778 } // for
779
780 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
781 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
782 // selects first based on argument cost, then on conversion cost.
783 AltList minArgCost;
784 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
785 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
786 }
787
788 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
789 AlternativeFinder funcFinder( indexer, env );
790 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
791
792 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
793 if ( agg->expr->get_results().size() == 1 ) {
794 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
795 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
796 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
797 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
798 } // if
799 } // if
800 } // for
801 }
802
803 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
804 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
805 }
806
807 void AlternativeFinder::visit( NameExpr *nameExpr ) {
808 std::list< DeclarationWithType* > declList;
809 indexer.lookupId( nameExpr->get_name(), declList );
810 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
811 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
812 VariableExpr newExpr( *i, nameExpr->get_argName() );
813 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
814 PRINT(
815 std::cerr << "decl is ";
816 (*i)->print( std::cerr );
817 std::cerr << std::endl;
818 std::cerr << "newExpr is ";
819 newExpr.print( std::cerr );
820 std::cerr << std::endl;
821 )
822 renameTypes( alternatives.back().expr );
823 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
824 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
825 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
826 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
827 } // if
828 } // for
829 }
830
831 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
832 // not sufficient to clone here, because variable's type may have changed
833 // since the VariableExpr was originally created.
834 alternatives.push_back( Alternative( new VariableExpr( variableExpr->get_var() ), env, Cost::zero ) );
835 }
836
837 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
838 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
839 }
840
841 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
842 if ( sizeofExpr->get_isType() ) {
843 // xxx - resolveTypeof?
844 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
845 } else {
846 // find all alternatives for the argument to sizeof
847 AlternativeFinder finder( indexer, env );
848 finder.find( sizeofExpr->get_expr() );
849 // find the lowest cost alternative among the alternatives, otherwise ambiguous
850 AltList winners;
851 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
852 if ( winners.size() != 1 ) {
853 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
854 } // if
855 // return the lowest cost alternative for the argument
856 Alternative &choice = winners.front();
857 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
858 } // if
859 }
860
861 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
862 if ( alignofExpr->get_isType() ) {
863 // xxx - resolveTypeof?
864 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
865 } else {
866 // find all alternatives for the argument to sizeof
867 AlternativeFinder finder( indexer, env );
868 finder.find( alignofExpr->get_expr() );
869 // find the lowest cost alternative among the alternatives, otherwise ambiguous
870 AltList winners;
871 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
872 if ( winners.size() != 1 ) {
873 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
874 } // if
875 // return the lowest cost alternative for the argument
876 Alternative &choice = winners.front();
877 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
878 } // if
879 }
880
881 template< typename StructOrUnionType >
882 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
883 std::list< Declaration* > members;
884 aggInst->lookup( name, members );
885 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
886 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
887 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt ), env, Cost::zero ) );
888 renameTypes( alternatives.back().expr );
889 } else {
890 assert( false );
891 }
892 }
893 }
894
895 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
896 AlternativeFinder funcFinder( indexer, env );
897 // xxx - resolveTypeof?
898 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
899 addOffsetof( structInst, offsetofExpr->get_member() );
900 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
901 addOffsetof( unionInst, offsetofExpr->get_member() );
902 }
903 }
904
905 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
906 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
907 }
908
909 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
910 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
911 }
912
913 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
914 // assume no polymorphism
915 // assume no implicit conversions
916 assert( function->get_parameters().size() == 1 );
917 PRINT(
918 std::cerr << "resolvAttr: funcDecl is ";
919 funcDecl->print( std::cerr );
920 std::cerr << " argType is ";
921 argType->print( std::cerr );
922 std::cerr << std::endl;
923 )
924 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
925 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
926 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
927 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
928 } // for
929 } // if
930 }
931
932 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
933 // assume no 'pointer-to-attribute'
934 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
935 assert( nameExpr );
936 std::list< DeclarationWithType* > attrList;
937 indexer.lookupId( nameExpr->get_name(), attrList );
938 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
939 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
940 // check if the type is function
941 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
942 // assume exactly one parameter
943 if ( function->get_parameters().size() == 1 ) {
944 if ( attrExpr->get_isType() ) {
945 resolveAttr( *i, function, attrExpr->get_type(), env );
946 } else {
947 AlternativeFinder finder( indexer, env );
948 finder.find( attrExpr->get_expr() );
949 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
950 if ( choice->expr->get_results().size() == 1 ) {
951 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
952 } // fi
953 } // for
954 } // if
955 } // if
956 } // if
957 } // for
958 } else {
959 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
960 VariableExpr newExpr( *i );
961 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
962 renameTypes( alternatives.back().expr );
963 } // for
964 } // if
965 }
966
967 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
968 AlternativeFinder firstFinder( indexer, env );
969 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
970 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
971 AlternativeFinder secondFinder( indexer, first->env );
972 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
973 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
974 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
975 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
976 }
977 }
978 }
979
980 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
981 AlternativeFinder firstFinder( indexer, env );
982 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
983 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
984 AlternativeFinder secondFinder( indexer, first->env );
985 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
986 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
987 AlternativeFinder thirdFinder( indexer, second->env );
988 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
989 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
990 OpenVarSet openVars;
991 AssertionSet needAssertions, haveAssertions;
992 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
993 std::list< Type* > commonTypes;
994 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 ) ) {
995 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
996 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
997 std::list< Type* >::const_iterator commonType = commonTypes.begin();
998 for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
999 if ( *commonType ) {
1000 newExpr->get_results().push_back( *commonType );
1001 } else {
1002 newExpr->get_results().push_back( (*original)->clone() );
1003 } // if
1004 } // for
1005 newAlt.expr = newExpr;
1006 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
1007 } // if
1008 } // for
1009 } // for
1010 } // for
1011 }
1012
1013 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
1014 TypeEnvironment newEnv( env );
1015 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
1016 AlternativeFinder secondFinder( indexer, newEnv );
1017 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
1018 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
1019 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
1020 } // for
1021 delete newFirstArg;
1022 }
1023
1024 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
1025 std::list< AlternativeFinder > subExprAlternatives;
1026 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
1027 std::list< AltList > possibilities;
1028 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
1029 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
1030 TupleExpr *newExpr = new TupleExpr;
1031 makeExprList( *i, newExpr->get_exprs() );
1032 for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
1033 for ( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
1034 newExpr->get_results().push_back( (*resultType)->clone() );
1035 } // for
1036 } // for
1037
1038 TypeEnvironment compositeEnv;
1039 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1040 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1041 } // for
1042 }
1043
1044 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1045 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1046 }
1047} // namespace ResolvExpr
1048
1049// Local Variables: //
1050// tab-width: 4 //
1051// mode: c++ //
1052// compile-command: "make install" //
1053// End: //
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