source: src/ResolvExpr/AlternativeFinder.cc@ fa463f1

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors ctor 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 fa463f1 was 31468a2, checked in by Thierry Delisle <tdelisle@…>, 9 years ago

Removed unused Designators folder
  • Property mode set to 100644
File size: 42.2 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/TupleAssignment.h"
41#include "Tuples/NameMatcher.h"
42#include "Common/utility.h"
43#include "InitTweak/InitTweak.h"
44
45extern bool resolvep;
46#define PRINT( text ) if ( resolvep ) { text }
47//#define DEBUG_COST
48
49namespace 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 namespace {
66 void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
67 for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
68 i->print( os, indent );
69 os << std::endl;
70 }
71 }
72
73 void makeExprList( const AltList &in, std::list< Expression* > &out ) {
74 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
75 out.push_back( i->expr->clone() );
76 }
77 }
78
79 Cost sumCost( const AltList &in ) {
80 Cost total;
81 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
82 total += i->cost;
83 }
84 return total;
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 for ( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
103 Type *newType = (*retType)->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 for ( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
135 alt.env.applyFree( *result );
136 }
137 *out++ = alt;
138 }
139 }
140
141 }
142
143 template< typename InputIterator, typename OutputIterator >
144 void findMinCost( InputIterator begin, InputIterator end, OutputIterator out ) {
145 AltList alternatives;
146
147 // select the alternatives that have the minimum parameter cost
148 Cost minCost = Cost::infinity;
149 for ( AltList::iterator i = begin; i != end; ++i ) {
150 if ( i->cost < minCost ) {
151 minCost = i->cost;
152 i->cost = i->cvtCost;
153 alternatives.clear();
154 alternatives.push_back( *i );
155 } else if ( i->cost == minCost ) {
156 i->cost = i->cvtCost;
157 alternatives.push_back( *i );
158 }
159 }
160 std::copy( alternatives.begin(), alternatives.end(), out );
161 }
162
163 template< typename InputIterator >
164 void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
165 while ( begin != end ) {
166 result.simpleCombine( (*begin++).env );
167 }
168 }
169
170 void renameTypes( Expression *expr ) {
171 for ( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
172 (*i)->accept( global_renamer );
173 }
174 }
175 }
176
177 template< typename InputIterator, typename OutputIterator >
178 void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
179 while ( begin != end ) {
180 AlternativeFinder finder( indexer, env );
181 finder.findWithAdjustment( *begin );
182 // XXX either this
183 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
184 // or XXX this
185 begin++;
186 PRINT(
187 std::cerr << "findSubExprs" << std::endl;
188 printAlts( finder.alternatives, std::cerr );
189 )
190 *out++ = finder;
191 }
192 }
193
194 AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
195 : indexer( indexer ), env( env ) {
196 }
197
198 void AlternativeFinder::find( Expression *expr, bool adjust ) {
199 expr->accept( *this );
200 if ( alternatives.empty() ) {
201 throw SemanticError( "No reasonable alternatives for expression ", expr );
202 }
203 for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
204 if ( adjust ) {
205 adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
206 }
207 }
208 PRINT(
209 std::cerr << "alternatives before prune:" << std::endl;
210 printAlts( alternatives, std::cerr );
211 )
212 AltList::iterator oldBegin = alternatives.begin();
213 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
214 if ( alternatives.begin() == oldBegin ) {
215 std::ostringstream stream;
216 stream << "Can't choose between alternatives for expression ";
217 expr->print( stream );
218 stream << "Alternatives are:";
219 AltList winners;
220 findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
221 printAlts( winners, stream, 8 );
222 throw SemanticError( stream.str() );
223 }
224 alternatives.erase( oldBegin, alternatives.end() );
225 PRINT(
226 std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
227 )
228
229 // Central location to handle gcc extension keyword for all expression types.
230 for ( Alternative &iter: alternatives ) {
231 iter.expr->set_extension( expr->get_extension() );
232 } // for
233 }
234
235 void AlternativeFinder::findWithAdjustment( Expression *expr ) {
236 find( expr, true );
237 }
238
239 template< typename StructOrUnionType >
240 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const std::string &name ) {
241 std::list< Declaration* > members;
242 aggInst->lookup( name, members );
243 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
244 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
245 alternatives.push_back( Alternative( new MemberExpr( dwt, expr->clone() ), env, newCost ) );
246 renameTypes( alternatives.back().expr );
247 } else {
248 assert( false );
249 }
250 }
251 }
252
253 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
254 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
255 }
256
257 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
258 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( alt.expr );
259 assert( appExpr );
260 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
261 assert( pointer );
262 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
263 assert( function );
264
265 Cost convCost( 0, 0, 0 );
266 std::list< DeclarationWithType* >& formals = function->get_parameters();
267 std::list< DeclarationWithType* >::iterator formal = formals.begin();
268 std::list< Expression* >& actuals = appExpr->get_args();
269 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
270 PRINT(
271 std::cerr << "actual expression:" << std::endl;
272 (*actualExpr)->print( std::cerr, 8 );
273 std::cerr << "--- results are" << std::endl;
274 printAll( (*actualExpr)->get_results(), std::cerr, 8 );
275 )
276 std::list< DeclarationWithType* >::iterator startFormal = formal;
277 Cost actualCost;
278 for ( std::list< Type* >::iterator actual = (*actualExpr)->get_results().begin(); actual != (*actualExpr)->get_results().end(); ++actual ) {
279 if ( formal == formals.end() ) {
280 if ( function->get_isVarArgs() ) {
281 convCost += Cost( 1, 0, 0 );
282 break;
283 } else {
284 return Cost::infinity;
285 }
286 }
287 PRINT(
288 std::cerr << std::endl << "converting ";
289 (*actual)->print( std::cerr, 8 );
290 std::cerr << std::endl << " to ";
291 (*formal)->get_type()->print( std::cerr, 8 );
292 )
293 Cost newCost = conversionCost( *actual, (*formal)->get_type(), indexer, alt.env );
294 PRINT(
295 std::cerr << std::endl << "cost is" << newCost << std::endl;
296 )
297
298 if ( newCost == Cost::infinity ) {
299 return newCost;
300 }
301 convCost += newCost;
302 actualCost += newCost;
303
304 convCost += Cost( 0, polyCost( (*formal)->get_type(), alt.env, indexer ) + polyCost( *actual, alt.env, indexer ), 0 );
305
306 formal++;
307 }
308 if ( actualCost != Cost( 0, 0, 0 ) ) {
309 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
310 startFormalPlusOne++;
311 if ( formal == startFormalPlusOne ) {
312 // not a tuple type
313 Type *newType = (*startFormal)->get_type()->clone();
314 alt.env.apply( newType );
315 *actualExpr = new CastExpr( *actualExpr, newType );
316 } else {
317 TupleType *newType = new TupleType( Type::Qualifiers() );
318 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
319 newType->get_types().push_back( (*i)->get_type()->clone() );
320 }
321 alt.env.apply( newType );
322 *actualExpr = new CastExpr( *actualExpr, newType );
323 }
324 }
325
326 }
327 if ( formal != formals.end() ) {
328 return Cost::infinity;
329 }
330
331 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
332 PRINT(
333 std::cerr << std::endl << "converting ";
334 assert->second.actualType->print( std::cerr, 8 );
335 std::cerr << std::endl << " to ";
336 assert->second.formalType->print( std::cerr, 8 );
337 )
338 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
339 PRINT(
340 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
341 )
342 if ( newCost == Cost::infinity ) {
343 return newCost;
344 }
345 convCost += newCost;
346
347 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
348 }
349
350 return convCost;
351 }
352
353 /// Adds type variables to the open variable set and marks their assertions
354 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
355 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
356 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
357 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
358 needAssertions[ *assert ] = true;
359 }
360/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
361 }
362 }
363
364 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
365 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
366 // make sure we don't widen any existing bindings
367 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
368 i->allowWidening = false;
369 }
370 resultEnv.extractOpenVars( openVars );
371
372 /*
373 Tuples::NameMatcher matcher( formals );
374 try {
375 matcher.match( actuals );
376 } catch ( Tuples::NoMatch &e ) {
377 std::cerr << "Alternative doesn't match: " << e.message << std::endl;
378 }
379 */
380 std::list< DeclarationWithType* >::iterator formal = formals.begin();
381 for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
382 for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
383 if ( formal == formals.end() ) {
384 return isVarArgs;
385 }
386 PRINT(
387 std::cerr << "formal type is ";
388 (*formal)->get_type()->print( std::cerr );
389 std::cerr << std::endl << "actual type is ";
390 (*actual)->print( std::cerr );
391 std::cerr << std::endl;
392 )
393 if ( ! unify( (*formal)->get_type(), *actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
394 return false;
395 }
396 formal++;
397 }
398 }
399 // Handling of default values
400 while ( formal != formals.end() ) {
401 if ( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
402 if ( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
403 // so far, only constant expressions are accepted as default values
404 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) )
405 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
406 if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
407 // XXX Don't know if this is right
408 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
409 formal++;
410 if ( formal == formals.end()) break;
411 }
412 return false;
413 }
414 return true;
415 }
416
417 // /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
418 //typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
419
420 static const int recursionLimit = /*10*/ 4; ///< Limit to depth of recursion satisfaction
421 //static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
422
423 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
424 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
425 if ( i->second == true ) {
426 i->first->accept( indexer );
427 }
428 }
429 }
430
431 template< typename ForwardIterator, typename OutputIterator >
432 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /*const AssertionParentSet &needParents,*/
433 int level, const SymTab::Indexer &indexer, OutputIterator out ) {
434 if ( begin == end ) {
435 if ( newNeed.empty() ) {
436 *out++ = newAlt;
437 return;
438 } else if ( level >= recursionLimit ) {
439 throw SemanticError( "Too many recursive assertions" );
440 } else {
441 AssertionSet newerNeed;
442 PRINT(
443 std::cerr << "recursing with new set:" << std::endl;
444 printAssertionSet( newNeed, std::cerr, 8 );
445 )
446 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /*needParents,*/ level+1, indexer, out );
447 return;
448 }
449 }
450
451 ForwardIterator cur = begin++;
452 if ( ! cur->second ) {
453 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /*needParents,*/ level, indexer, out );
454 }
455 DeclarationWithType *curDecl = cur->first;
456 PRINT(
457 std::cerr << "inferRecursive: assertion is ";
458 curDecl->print( std::cerr );
459 std::cerr << std::endl;
460 )
461 std::list< DeclarationWithType* > candidates;
462 decls.lookupId( curDecl->get_name(), candidates );
463/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
464 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
465 PRINT(
466 std::cerr << "inferRecursive: candidate is ";
467 (*candidate)->print( std::cerr );
468 std::cerr << std::endl;
469 )
470
471 AssertionSet newHave, newerNeed( newNeed );
472 TypeEnvironment newEnv( newAlt.env );
473 OpenVarSet newOpenVars( openVars );
474 Type *adjType = (*candidate)->get_type()->clone();
475 adjustExprType( adjType, newEnv, indexer );
476 adjType->accept( global_renamer );
477 PRINT(
478 std::cerr << "unifying ";
479 curDecl->get_type()->print( std::cerr );
480 std::cerr << " with ";
481 adjType->print( std::cerr );
482 std::cerr << std::endl;
483 )
484 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
485 PRINT(
486 std::cerr << "success!" << std::endl;
487 )
488 SymTab::Indexer newDecls( decls );
489 addToIndexer( newHave, newDecls );
490 Alternative newerAlt( newAlt );
491 newerAlt.env = newEnv;
492 assert( (*candidate)->get_uniqueId() );
493 DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
494 //AssertionParentSet newNeedParents( needParents );
495 // skip repeatingly-self-recursive assertion satisfaction
496 // DOESN'T WORK: grandchild nodes conflict with their cousins
497 //if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
498 Expression *varExpr = new VariableExpr( candDecl );
499 deleteAll( varExpr->get_results() );
500 varExpr->get_results().clear();
501 varExpr->get_results().push_front( adjType->clone() );
502 PRINT(
503 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
504 curDecl->print( std::cerr );
505 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
506 (*candidate)->print( std::cerr );
507 std::cerr << std::endl;
508 )
509 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
510 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
511 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
512 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /*newNeedParents,*/ level, indexer, out );
513 } else {
514 delete adjType;
515 }
516 }
517 }
518
519 template< typename OutputIterator >
520 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
521// PRINT(
522// std::cerr << "inferParameters: assertions needed are" << std::endl;
523// printAll( need, std::cerr, 8 );
524// )
525 SymTab::Indexer decls( indexer );
526 PRINT(
527 std::cerr << "============= original indexer" << std::endl;
528 indexer.print( std::cerr );
529 std::cerr << "============= new indexer" << std::endl;
530 decls.print( std::cerr );
531 )
532 addToIndexer( have, decls );
533 AssertionSet newNeed;
534 //AssertionParentSet needParents;
535 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /*needParents,*/ 0, indexer, out );
536// PRINT(
537// std::cerr << "declaration 14 is ";
538// Declaration::declFromId
539// *out++ = newAlt;
540// )
541 }
542
543 template< typename OutputIterator >
544 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
545 OpenVarSet openVars;
546 AssertionSet resultNeed, resultHave;
547 TypeEnvironment resultEnv;
548 makeUnifiableVars( funcType, openVars, resultNeed );
549 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
550 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
551 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
552 makeExprList( actualAlt, appExpr->get_args() );
553 PRINT(
554 std::cerr << "need assertions:" << std::endl;
555 printAssertionSet( resultNeed, std::cerr, 8 );
556 )
557 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
558 }
559 }
560
561 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
562 bool doneInit = false;
563 AlternativeFinder funcOpFinder( indexer, env );
564
565 AlternativeFinder funcFinder( indexer, env );
566
567 {
568 std::string fname = InitTweak::getFunctionName( untypedExpr );
569 if ( fname == "&&" ) {
570 VoidType v = Type::Qualifiers(); // resolve to type void *
571 PointerType pt( Type::Qualifiers(), v.clone() );
572 UntypedExpr *vexpr = untypedExpr->clone();
573 vexpr->get_results().push_front( pt.clone() );
574 alternatives.push_back( Alternative( vexpr, env, Cost()) );
575 return;
576 }
577 }
578
579 funcFinder.findWithAdjustment( untypedExpr->get_function() );
580 std::list< AlternativeFinder > argAlternatives;
581 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
582
583 std::list< AltList > possibilities;
584 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
585
586 Tuples::TupleAssignSpotter tassign( this );
587 if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
588 // take care of possible tuple assignments, or discard expression
589 return;
590 } // else ...
591
592 AltList candidates;
593 SemanticError errors;
594
595 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
596 try {
597 PRINT(
598 std::cerr << "working on alternative: " << std::endl;
599 func->print( std::cerr, 8 );
600 )
601 // check if the type is pointer to function
602 PointerType *pointer;
603 if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
604 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
605 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
606 // XXX
607 //Designators::check_alternative( function, *actualAlt );
608 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
609 }
610 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
611 EqvClass eqvClass;
612 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
613 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
614 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
615 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
616 } // for
617 } // if
618 } // if
619 } // if
620 } else {
621 // seek a function operator that's compatible
622 if ( ! doneInit ) {
623 doneInit = true;
624 NameExpr *opExpr = new NameExpr( "?()" );
625 try {
626 funcOpFinder.findWithAdjustment( opExpr );
627 } catch( SemanticError &e ) {
628 // it's ok if there aren't any defined function ops
629 }
630 PRINT(
631 std::cerr << "known function ops:" << std::endl;
632 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
633 )
634 }
635
636 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
637 // check if the type is pointer to function
638 PointerType *pointer;
639 if ( funcOp->expr->get_results().size() == 1
640 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
641 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
642 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
643 AltList currentAlt;
644 currentAlt.push_back( *func );
645 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
646 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
647 } // for
648 } // if
649 } // if
650 } // for
651 } // if
652 } catch ( SemanticError &e ) {
653 errors.append( e );
654 }
655 } // for
656
657 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
658 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
659
660 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
661 Cost cvtCost = computeConversionCost( *withFunc, indexer );
662
663 PRINT(
664 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
665 assert( appExpr );
666 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
667 assert( pointer );
668 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
669 assert( function );
670 std::cerr << "Case +++++++++++++" << std::endl;
671 std::cerr << "formals are:" << std::endl;
672 printAll( function->get_parameters(), std::cerr, 8 );
673 std::cerr << "actuals are:" << std::endl;
674 printAll( appExpr->get_args(), std::cerr, 8 );
675 std::cerr << "bindings are:" << std::endl;
676 withFunc->env.print( std::cerr, 8 );
677 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
678 )
679 if ( cvtCost != Cost::infinity ) {
680 withFunc->cvtCost = cvtCost;
681 alternatives.push_back( *withFunc );
682 } // if
683 } // for
684 candidates.clear();
685 candidates.splice( candidates.end(), alternatives );
686
687 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
688 }
689
690 bool isLvalue( Expression *expr ) {
691 for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
692 if ( !(*i)->get_isLvalue() ) return false;
693 } // for
694 return true;
695 }
696
697 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
698 AlternativeFinder finder( indexer, env );
699 finder.find( addressExpr->get_arg() );
700 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
701 if ( isLvalue( i->expr ) ) {
702 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
703 } // if
704 } // for
705 }
706
707 void AlternativeFinder::visit( CastExpr *castExpr ) {
708 for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
709 SymTab::validateType( *i, &indexer );
710 adjustExprType( *i, env, indexer );
711 } // for
712
713 AlternativeFinder finder( indexer, env );
714 finder.findWithAdjustment( castExpr->get_arg() );
715
716 AltList candidates;
717 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
718 AssertionSet needAssertions, haveAssertions;
719 OpenVarSet openVars;
720
721 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
722 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
723 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
724 // to.
725 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
726 if ( discardedValues < 0 ) continue;
727 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
728 std::advance( candidate_end, castExpr->get_results().size() );
729 // unification run for side-effects
730 unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
731 (*i).expr->get_results().begin(), candidate_end,
732 i->env, needAssertions, haveAssertions, openVars, indexer );
733 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
734 castExpr->get_results().begin(), castExpr->get_results().end(),
735 indexer, i->env );
736 if ( thisCost != Cost::infinity ) {
737 // count one safe conversion for each value that is thrown away
738 thisCost += Cost( 0, 0, discardedValues );
739 CastExpr *newExpr = castExpr->clone();
740 newExpr->set_arg( i->expr->clone() );
741 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
742 } // if
743 } // for
744
745 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
746 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
747 // selects first based on argument cost, then on conversion cost.
748 AltList minArgCost;
749 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
750 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
751 }
752
753 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
754 AlternativeFinder funcFinder( indexer, env );
755 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
756
757 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
758 if ( agg->expr->get_results().size() == 1 ) {
759 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
760 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
761 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
762 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
763 } // if
764 } // if
765 } // for
766 }
767
768 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
769 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
770 }
771
772 void AlternativeFinder::visit( NameExpr *nameExpr ) {
773 std::list< DeclarationWithType* > declList;
774 indexer.lookupId( nameExpr->get_name(), declList );
775 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
776 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
777 VariableExpr newExpr( *i, nameExpr->get_argName() );
778 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
779 PRINT(
780 std::cerr << "decl is ";
781 (*i)->print( std::cerr );
782 std::cerr << std::endl;
783 std::cerr << "newExpr is ";
784 newExpr.print( std::cerr );
785 std::cerr << std::endl;
786 )
787 renameTypes( alternatives.back().expr );
788 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
789 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
790 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
791 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
792 } // if
793 } // for
794 }
795
796 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
797 alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
798 }
799
800 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
801 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
802 }
803
804 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
805 if ( sizeofExpr->get_isType() ) {
806 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
807 } else {
808 // find all alternatives for the argument to sizeof
809 AlternativeFinder finder( indexer, env );
810 finder.find( sizeofExpr->get_expr() );
811 // find the lowest cost alternative among the alternatives, otherwise ambiguous
812 AltList winners;
813 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
814 if ( winners.size() != 1 ) {
815 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
816 } // if
817 // return the lowest cost alternative for the argument
818 Alternative &choice = winners.front();
819 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
820 } // if
821 }
822
823 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
824 if ( alignofExpr->get_isType() ) {
825 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
826 } else {
827 // find all alternatives for the argument to sizeof
828 AlternativeFinder finder( indexer, env );
829 finder.find( alignofExpr->get_expr() );
830 // find the lowest cost alternative among the alternatives, otherwise ambiguous
831 AltList winners;
832 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
833 if ( winners.size() != 1 ) {
834 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
835 } // if
836 // return the lowest cost alternative for the argument
837 Alternative &choice = winners.front();
838 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
839 } // if
840 }
841
842 template< typename StructOrUnionType >
843 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
844 std::list< Declaration* > members;
845 aggInst->lookup( name, members );
846 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
847 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
848 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt ), env, Cost::zero ) );
849 renameTypes( alternatives.back().expr );
850 } else {
851 assert( false );
852 }
853 }
854 }
855
856 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
857 AlternativeFinder funcFinder( indexer, env );
858 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
859 addOffsetof( structInst, offsetofExpr->get_member() );
860 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
861 addOffsetof( unionInst, offsetofExpr->get_member() );
862 }
863 }
864
865 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
866 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
867 }
868
869 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
870 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
871 }
872
873 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
874 // assume no polymorphism
875 // assume no implicit conversions
876 assert( function->get_parameters().size() == 1 );
877 PRINT(
878 std::cerr << "resolvAttr: funcDecl is ";
879 funcDecl->print( std::cerr );
880 std::cerr << " argType is ";
881 argType->print( std::cerr );
882 std::cerr << std::endl;
883 )
884 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
885 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
886 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
887 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
888 } // for
889 } // if
890 }
891
892 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
893 // assume no 'pointer-to-attribute'
894 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
895 assert( nameExpr );
896 std::list< DeclarationWithType* > attrList;
897 indexer.lookupId( nameExpr->get_name(), attrList );
898 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
899 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
900 // check if the type is function
901 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
902 // assume exactly one parameter
903 if ( function->get_parameters().size() == 1 ) {
904 if ( attrExpr->get_isType() ) {
905 resolveAttr( *i, function, attrExpr->get_type(), env );
906 } else {
907 AlternativeFinder finder( indexer, env );
908 finder.find( attrExpr->get_expr() );
909 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
910 if ( choice->expr->get_results().size() == 1 ) {
911 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
912 } // fi
913 } // for
914 } // if
915 } // if
916 } // if
917 } // for
918 } else {
919 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
920 VariableExpr newExpr( *i );
921 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
922 renameTypes( alternatives.back().expr );
923 } // for
924 } // if
925 }
926
927 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
928 AlternativeFinder firstFinder( indexer, env );
929 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
930 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
931 AlternativeFinder secondFinder( indexer, first->env );
932 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
933 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
934 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
935 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
936 }
937 }
938 }
939
940 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
941 AlternativeFinder firstFinder( indexer, env );
942 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
943 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
944 AlternativeFinder secondFinder( indexer, first->env );
945 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
946 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
947 AlternativeFinder thirdFinder( indexer, second->env );
948 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
949 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
950 OpenVarSet openVars;
951 AssertionSet needAssertions, haveAssertions;
952 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
953 std::list< Type* > commonTypes;
954 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 ) ) {
955 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
956 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
957 std::list< Type* >::const_iterator commonType = commonTypes.begin();
958 for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
959 if ( *commonType ) {
960 newExpr->get_results().push_back( *commonType );
961 } else {
962 newExpr->get_results().push_back( (*original)->clone() );
963 } // if
964 } // for
965 newAlt.expr = newExpr;
966 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
967 } // if
968 } // for
969 } // for
970 } // for
971 }
972
973 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
974 TypeEnvironment newEnv( env );
975 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
976 AlternativeFinder secondFinder( indexer, newEnv );
977 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
978 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
979 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
980 } // for
981 delete newFirstArg;
982 }
983
984 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
985 std::list< AlternativeFinder > subExprAlternatives;
986 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
987 std::list< AltList > possibilities;
988 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
989 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
990 TupleExpr *newExpr = new TupleExpr;
991 makeExprList( *i, newExpr->get_exprs() );
992 for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
993 for ( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
994 newExpr->get_results().push_back( (*resultType)->clone() );
995 } // for
996 } // for
997
998 TypeEnvironment compositeEnv;
999 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1000 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1001 } // for
1002 }
1003
1004 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1005 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1006 }
1007} // namespace ResolvExpr
1008
1009// Local Variables: //
1010// tab-width: 4 //
1011// mode: c++ //
1012// compile-command: "make install" //
1013// End: //
Note: See TracBrowser for help on using the repository browser.