source: src/ResolvExpr/AlternativeFinder.cc@ e04ef3a

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors ctor deferred_resn demangler enum forall-pointer-decay gc_noraii jacob/cs343-translation jenkins-sandbox memory 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 e04ef3a was e04ef3a, checked in by Peter A. Buhr <pabuhr@…>, 9 years ago

add gcc extension, first attempt, not done yet
  • Property mode set to 100644
File size: 41.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// AlternativeFinder.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sat May 16 23:52:08 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Jun 13 16:13:54 2016
13// Update Count : 25
14//
15
16#include <list>
17#include <iterator>
18#include <algorithm>
19#include <functional>
20#include <cassert>
21
22#include "AlternativeFinder.h"
23#include "Alternative.h"
24#include "Cost.h"
25#include "typeops.h"
26#include "Unify.h"
27#include "RenameVars.h"
28#include "SynTree/Type.h"
29#include "SynTree/Declaration.h"
30#include "SynTree/Expression.h"
31#include "SynTree/Initializer.h"
32#include "SynTree/Visitor.h"
33#include "SymTab/Indexer.h"
34#include "SymTab/Mangler.h"
35#include "SynTree/TypeSubstitution.h"
36#include "SymTab/Validate.h"
37#include "Designators/Processor.h"
38#include "Tuples/TupleAssignment.h"
39#include "Tuples/NameMatcher.h"
40#include "Common/utility.h"
41
42extern bool resolvep;
43#define PRINT( text ) if ( resolvep ) { text }
44//#define DEBUG_COST
45
46namespace ResolvExpr {
47 Expression *resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
48 CastExpr *castToVoid = new CastExpr( expr );
49
50 AlternativeFinder finder( indexer, env );
51 finder.findWithAdjustment( castToVoid );
52
53 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
54 // interpretations, an exception has already been thrown.
55 assert( finder.get_alternatives().size() == 1 );
56 CastExpr *newExpr = dynamic_cast< CastExpr* >( finder.get_alternatives().front().expr );
57 assert( newExpr );
58 env = finder.get_alternatives().front().env;
59 return newExpr->get_arg()->clone();
60 }
61
62 namespace {
63 void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
64 for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
65 i->print( os, indent );
66 os << std::endl;
67 }
68 }
69
70 void makeExprList( const AltList &in, std::list< Expression* > &out ) {
71 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
72 out.push_back( i->expr->clone() );
73 }
74 }
75
76 Cost sumCost( const AltList &in ) {
77 Cost total;
78 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
79 total += i->cost;
80 }
81 return total;
82 }
83
84 struct PruneStruct {
85 bool isAmbiguous;
86 AltList::iterator candidate;
87 PruneStruct() {}
88 PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
89 };
90
91 /// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
92 template< typename InputIterator, typename OutputIterator >
93 void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
94 // select the alternatives that have the minimum conversion cost for a particular set of result types
95 std::map< std::string, PruneStruct > selected;
96 for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
97 PruneStruct current( candidate );
98 std::string mangleName;
99 for ( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
100 Type *newType = (*retType)->clone();
101 candidate->env.apply( newType );
102 mangleName += SymTab::Mangler::mangle( newType );
103 delete newType;
104 }
105 std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
106 if ( mapPlace != selected.end() ) {
107 if ( candidate->cost < mapPlace->second.candidate->cost ) {
108 PRINT(
109 std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
110 )
111 selected[ mangleName ] = current;
112 } else if ( candidate->cost == mapPlace->second.candidate->cost ) {
113 PRINT(
114 std::cerr << "marking ambiguous" << std::endl;
115 )
116 mapPlace->second.isAmbiguous = true;
117 }
118 } else {
119 selected[ mangleName ] = current;
120 }
121 }
122
123 PRINT(
124 std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
125 )
126
127 // accept the alternatives that were unambiguous
128 for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
129 if ( ! target->second.isAmbiguous ) {
130 Alternative &alt = *target->second.candidate;
131 for ( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
132 alt.env.applyFree( *result );
133 }
134 *out++ = alt;
135 }
136 }
137
138 }
139
140 template< typename InputIterator, typename OutputIterator >
141 void findMinCost( InputIterator begin, InputIterator end, OutputIterator out ) {
142 AltList alternatives;
143
144 // select the alternatives that have the minimum parameter cost
145 Cost minCost = Cost::infinity;
146 for ( AltList::iterator i = begin; i != end; ++i ) {
147 if ( i->cost < minCost ) {
148 minCost = i->cost;
149 i->cost = i->cvtCost;
150 alternatives.clear();
151 alternatives.push_back( *i );
152 } else if ( i->cost == minCost ) {
153 i->cost = i->cvtCost;
154 alternatives.push_back( *i );
155 }
156 }
157 std::copy( alternatives.begin(), alternatives.end(), out );
158 }
159
160 template< typename InputIterator >
161 void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
162 while ( begin != end ) {
163 result.simpleCombine( (*begin++).env );
164 }
165 }
166
167 void renameTypes( Expression *expr ) {
168 for ( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
169 (*i)->accept( global_renamer );
170 }
171 }
172 }
173
174 template< typename InputIterator, typename OutputIterator >
175 void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
176 while ( begin != end ) {
177 AlternativeFinder finder( indexer, env );
178 finder.findWithAdjustment( *begin );
179 // XXX either this
180 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
181 // or XXX this
182 begin++;
183 PRINT(
184 std::cerr << "findSubExprs" << std::endl;
185 printAlts( finder.alternatives, std::cerr );
186 )
187 *out++ = finder;
188 }
189 }
190
191 AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
192 : indexer( indexer ), env( env ) {
193 }
194
195 void AlternativeFinder::find( Expression *expr, bool adjust ) {
196 expr->accept( *this );
197 if ( alternatives.empty() ) {
198 throw SemanticError( "No reasonable alternatives for expression ", expr );
199 }
200 for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
201 if ( adjust ) {
202 adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
203 }
204 }
205 PRINT(
206 std::cerr << "alternatives before prune:" << std::endl;
207 printAlts( alternatives, std::cerr );
208 )
209 AltList::iterator oldBegin = alternatives.begin();
210 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
211 if ( alternatives.begin() == oldBegin ) {
212 std::ostringstream stream;
213 stream << "Can't choose between alternatives for expression ";
214 expr->print( stream );
215 stream << "Alternatives are:";
216 AltList winners;
217 findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
218 printAlts( winners, stream, 8 );
219 throw SemanticError( stream.str() );
220 }
221 alternatives.erase( oldBegin, alternatives.end() );
222 PRINT(
223 std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
224 )
225 }
226
227 void AlternativeFinder::findWithAdjustment( Expression *expr ) {
228 find( expr, true );
229 }
230
231 template< typename StructOrUnionType >
232 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const std::string &name ) {
233 std::list< Declaration* > members;
234 aggInst->lookup( name, members );
235 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
236 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
237 alternatives.push_back( Alternative( new MemberExpr( dwt->clone(), expr->clone() ), env, newCost ) );
238 renameTypes( alternatives.back().expr );
239 } else {
240 assert( false );
241 }
242 }
243 }
244
245 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
246 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
247 }
248
249 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
250 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( alt.expr );
251 assert( appExpr );
252 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
253 assert( pointer );
254 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
255 assert( function );
256
257 Cost convCost( 0, 0, 0 );
258 std::list< DeclarationWithType* >& formals = function->get_parameters();
259 std::list< DeclarationWithType* >::iterator formal = formals.begin();
260 std::list< Expression* >& actuals = appExpr->get_args();
261 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
262 PRINT(
263 std::cerr << "actual expression:" << std::endl;
264 (*actualExpr)->print( std::cerr, 8 );
265 std::cerr << "--- results are" << std::endl;
266 printAll( (*actualExpr)->get_results(), std::cerr, 8 );
267 )
268 std::list< DeclarationWithType* >::iterator startFormal = formal;
269 Cost actualCost;
270 for ( std::list< Type* >::iterator actual = (*actualExpr)->get_results().begin(); actual != (*actualExpr)->get_results().end(); ++actual ) {
271 if ( formal == formals.end() ) {
272 if ( function->get_isVarArgs() ) {
273 convCost += Cost( 1, 0, 0 );
274 break;
275 } else {
276 return Cost::infinity;
277 }
278 }
279 PRINT(
280 std::cerr << std::endl << "converting ";
281 (*actual)->print( std::cerr, 8 );
282 std::cerr << std::endl << " to ";
283 (*formal)->get_type()->print( std::cerr, 8 );
284 )
285 Cost newCost = conversionCost( *actual, (*formal)->get_type(), indexer, alt.env );
286 PRINT(
287 std::cerr << std::endl << "cost is" << newCost << std::endl;
288 )
289
290 if ( newCost == Cost::infinity ) {
291 return newCost;
292 }
293 convCost += newCost;
294 actualCost += newCost;
295
296 convCost += Cost( 0, polyCost( (*formal)->get_type(), alt.env, indexer ) + polyCost( *actual, alt.env, indexer ), 0 );
297
298 formal++;
299 }
300 if ( actualCost != Cost( 0, 0, 0 ) ) {
301 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
302 startFormalPlusOne++;
303 if ( formal == startFormalPlusOne ) {
304 // not a tuple type
305 Type *newType = (*startFormal)->get_type()->clone();
306 alt.env.apply( newType );
307 *actualExpr = new CastExpr( *actualExpr, newType );
308 } else {
309 TupleType *newType = new TupleType( Type::Qualifiers() );
310 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
311 newType->get_types().push_back( (*i)->get_type()->clone() );
312 }
313 alt.env.apply( newType );
314 *actualExpr = new CastExpr( *actualExpr, newType );
315 }
316 }
317
318 }
319 if ( formal != formals.end() ) {
320 return Cost::infinity;
321 }
322
323 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
324 PRINT(
325 std::cerr << std::endl << "converting ";
326 assert->second.actualType->print( std::cerr, 8 );
327 std::cerr << std::endl << " to ";
328 assert->second.formalType->print( std::cerr, 8 );
329 )
330 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
331 PRINT(
332 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
333 )
334 if ( newCost == Cost::infinity ) {
335 return newCost;
336 }
337 convCost += newCost;
338
339 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
340 }
341
342 return convCost;
343 }
344
345 /// Adds type variables to the open variable set and marks their assertions
346 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
347 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
348 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
349 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
350 needAssertions[ *assert ] = true;
351 }
352/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
353 }
354 }
355
356 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
357 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
358 // make sure we don't widen any existing bindings
359 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
360 i->allowWidening = false;
361 }
362 resultEnv.extractOpenVars( openVars );
363
364 /*
365 Tuples::NameMatcher matcher( formals );
366 try {
367 matcher.match( actuals );
368 } catch ( Tuples::NoMatch &e ) {
369 std::cerr << "Alternative doesn't match: " << e.message << std::endl;
370 }
371 */
372 std::list< DeclarationWithType* >::iterator formal = formals.begin();
373 for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
374 for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
375 if ( formal == formals.end() ) {
376 return isVarArgs;
377 }
378 PRINT(
379 std::cerr << "formal type is ";
380 (*formal)->get_type()->print( std::cerr );
381 std::cerr << std::endl << "actual type is ";
382 (*actual)->print( std::cerr );
383 std::cerr << std::endl;
384 )
385 if ( ! unify( (*formal)->get_type(), *actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
386 return false;
387 }
388 formal++;
389 }
390 }
391 // Handling of default values
392 while ( formal != formals.end() ) {
393 if ( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
394 if ( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
395 // so far, only constant expressions are accepted as default values
396 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) )
397 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
398 if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
399 // XXX Don't know if this is right
400 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
401 formal++;
402 if ( formal == formals.end()) break;
403 }
404 return false;
405 }
406 return true;
407 }
408
409 static const int recursionLimit = 10;
410
411 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
412 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
413 if ( i->second == true ) {
414 i->first->accept( indexer );
415 }
416 }
417 }
418
419 template< typename ForwardIterator, typename OutputIterator >
420 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, int level, const SymTab::Indexer &indexer, OutputIterator out ) {
421 if ( begin == end ) {
422 if ( newNeed.empty() ) {
423 *out++ = newAlt;
424 return;
425 } else if ( level >= recursionLimit ) {
426 throw SemanticError( "Too many recursive assertions" );
427 } else {
428 AssertionSet newerNeed;
429 PRINT(
430 std::cerr << "recursing with new set:" << std::endl;
431 printAssertionSet( newNeed, std::cerr, 8 );
432 )
433 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, level+1, indexer, out );
434 return;
435 }
436 }
437
438 ForwardIterator cur = begin++;
439 if ( ! cur->second ) {
440 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, level, indexer, out );
441 }
442 DeclarationWithType *curDecl = cur->first;
443 PRINT(
444 std::cerr << "inferRecursive: assertion is ";
445 curDecl->print( std::cerr );
446 std::cerr << std::endl;
447 )
448 std::list< DeclarationWithType* > candidates;
449 decls.lookupId( curDecl->get_name(), candidates );
450/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
451 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
452 PRINT(
453 std::cerr << "inferRecursive: candidate is ";
454 (*candidate)->print( std::cerr );
455 std::cerr << std::endl;
456 )
457 AssertionSet newHave, newerNeed( newNeed );
458 TypeEnvironment newEnv( newAlt.env );
459 OpenVarSet newOpenVars( openVars );
460 Type *adjType = (*candidate)->get_type()->clone();
461 adjustExprType( adjType, newEnv, indexer );
462 adjType->accept( global_renamer );
463 PRINT(
464 std::cerr << "unifying ";
465 curDecl->get_type()->print( std::cerr );
466 std::cerr << " with ";
467 adjType->print( std::cerr );
468 std::cerr << std::endl;
469 )
470 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
471 PRINT(
472 std::cerr << "success!" << std::endl;
473 )
474 SymTab::Indexer newDecls( decls );
475 addToIndexer( newHave, newDecls );
476 Alternative newerAlt( newAlt );
477 newerAlt.env = newEnv;
478 assert( (*candidate)->get_uniqueId() );
479 Expression *varExpr = new VariableExpr( static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) ) );
480 deleteAll( varExpr->get_results() );
481 varExpr->get_results().clear();
482 varExpr->get_results().push_front( adjType->clone() );
483 PRINT(
484 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
485 curDecl->print( std::cerr );
486 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
487 (*candidate)->print( std::cerr );
488 std::cerr << std::endl;
489 )
490 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
491 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
492 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
493 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, level, indexer, out );
494 } else {
495 delete adjType;
496 }
497 }
498 }
499
500 template< typename OutputIterator >
501 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
502// PRINT(
503// std::cerr << "inferParameters: assertions needed are" << std::endl;
504// printAll( need, std::cerr, 8 );
505// )
506 SymTab::Indexer decls( indexer );
507 PRINT(
508 std::cerr << "============= original indexer" << std::endl;
509 indexer.print( std::cerr );
510 std::cerr << "============= new indexer" << std::endl;
511 decls.print( std::cerr );
512 )
513 addToIndexer( have, decls );
514 AssertionSet newNeed;
515 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, 0, indexer, out );
516// PRINT(
517// std::cerr << "declaration 14 is ";
518// Declaration::declFromId
519// *out++ = newAlt;
520// )
521 }
522
523 template< typename OutputIterator >
524 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
525 OpenVarSet openVars;
526 AssertionSet resultNeed, resultHave;
527 TypeEnvironment resultEnv;
528 makeUnifiableVars( funcType, openVars, resultNeed );
529 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
530 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
531 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
532 makeExprList( actualAlt, appExpr->get_args() );
533 PRINT(
534 std::cerr << "need assertions:" << std::endl;
535 printAssertionSet( resultNeed, std::cerr, 8 );
536 )
537 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
538 }
539 }
540
541 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
542 bool doneInit = false;
543 AlternativeFinder funcOpFinder( indexer, env );
544
545 AlternativeFinder funcFinder( indexer, env );
546
547 {
548 NameExpr *fname = 0;;
549 if ( ( fname = dynamic_cast<NameExpr *>( untypedExpr->get_function()))
550 && ( fname->get_name() == std::string("&&")) ) {
551 VoidType v = Type::Qualifiers(); // resolve to type void *
552 PointerType pt( Type::Qualifiers(), v.clone() );
553 UntypedExpr *vexpr = untypedExpr->clone();
554 vexpr->get_results().push_front( pt.clone() );
555 alternatives.push_back( Alternative( vexpr, env, Cost()) );
556 return;
557 }
558 }
559
560 funcFinder.findWithAdjustment( untypedExpr->get_function() );
561 std::list< AlternativeFinder > argAlternatives;
562 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
563
564 std::list< AltList > possibilities;
565 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
566
567 Tuples::TupleAssignSpotter tassign( this );
568 if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
569 // take care of possible tuple assignments, or discard expression
570 return;
571 } // else ...
572
573 AltList candidates;
574 SemanticError errors;
575
576 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
577 try {
578 PRINT(
579 std::cerr << "working on alternative: " << std::endl;
580 func->print( std::cerr, 8 );
581 )
582 // check if the type is pointer to function
583 PointerType *pointer;
584 if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
585 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
586 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
587 // XXX
588 //Designators::check_alternative( function, *actualAlt );
589 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
590 }
591 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
592 EqvClass eqvClass;
593 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
594 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
595 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
596 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
597 } // for
598 } // if
599 } // if
600 } // if
601 } else {
602 // seek a function operator that's compatible
603 if ( ! doneInit ) {
604 doneInit = true;
605 NameExpr *opExpr = new NameExpr( "?()" );
606 try {
607 funcOpFinder.findWithAdjustment( opExpr );
608 } catch( SemanticError &e ) {
609 // it's ok if there aren't any defined function ops
610 }
611 PRINT(
612 std::cerr << "known function ops:" << std::endl;
613 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
614 )
615 }
616
617 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
618 // check if the type is pointer to function
619 PointerType *pointer;
620 if ( funcOp->expr->get_results().size() == 1
621 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
622 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
623 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
624 AltList currentAlt;
625 currentAlt.push_back( *func );
626 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
627 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
628 } // for
629 } // if
630 } // if
631 } // for
632 } // if
633 } catch ( SemanticError &e ) {
634 errors.append( e );
635 }
636 } // for
637
638 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
639 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
640
641 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
642 Cost cvtCost = computeConversionCost( *withFunc, indexer );
643
644 PRINT(
645 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
646 assert( appExpr );
647 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
648 assert( pointer );
649 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
650 assert( function );
651 std::cerr << "Case +++++++++++++" << std::endl;
652 std::cerr << "formals are:" << std::endl;
653 printAll( function->get_parameters(), std::cerr, 8 );
654 std::cerr << "actuals are:" << std::endl;
655 printAll( appExpr->get_args(), std::cerr, 8 );
656 std::cerr << "bindings are:" << std::endl;
657 withFunc->env.print( std::cerr, 8 );
658 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
659 )
660 if ( cvtCost != Cost::infinity ) {
661 withFunc->cvtCost = cvtCost;
662 alternatives.push_back( *withFunc );
663 } // if
664 } // for
665 candidates.clear();
666 candidates.splice( candidates.end(), alternatives );
667
668 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
669 }
670
671 bool isLvalue( Expression *expr ) {
672 for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
673 if ( !(*i)->get_isLvalue() ) return false;
674 } // for
675 return true;
676 }
677
678 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
679 AlternativeFinder finder( indexer, env );
680 finder.find( addressExpr->get_arg() );
681 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
682 if ( isLvalue( i->expr ) ) {
683 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
684 } // if
685 } // for
686 }
687
688 void AlternativeFinder::visit( CastExpr *castExpr ) {
689 for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
690 SymTab::validateType( *i, &indexer );
691 adjustExprType( *i, env, indexer );
692 } // for
693
694 AlternativeFinder finder( indexer, env );
695 finder.findWithAdjustment( castExpr->get_arg() );
696
697 AltList candidates;
698 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
699 AssertionSet needAssertions, haveAssertions;
700 OpenVarSet openVars;
701
702 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
703 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
704 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
705 // to.
706 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
707 if ( discardedValues < 0 ) continue;
708 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
709 std::advance( candidate_end, castExpr->get_results().size() );
710 // unification run for side-effects
711 unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
712 (*i).expr->get_results().begin(), candidate_end,
713 i->env, needAssertions, haveAssertions, openVars, indexer );
714 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
715 castExpr->get_results().begin(), castExpr->get_results().end(),
716 indexer, i->env );
717 if ( thisCost != Cost::infinity ) {
718 // count one safe conversion for each value that is thrown away
719 thisCost += Cost( 0, 0, discardedValues );
720 CastExpr *newExpr = castExpr->clone();
721 newExpr->set_arg( i->expr->clone() );
722 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
723 } // if
724 } // for
725
726 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
727 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
728 // selects first based on argument cost, then on conversion cost.
729 AltList minArgCost;
730 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
731 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
732 }
733
734 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
735 AlternativeFinder funcFinder( indexer, env );
736 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
737
738 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
739 if ( agg->expr->get_results().size() == 1 ) {
740 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
741 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
742 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
743 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
744 } // if
745 } // if
746 } // for
747 }
748
749 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
750 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
751 }
752
753 void AlternativeFinder::visit( NameExpr *nameExpr ) {
754 std::list< DeclarationWithType* > declList;
755 indexer.lookupId( nameExpr->get_name(), declList );
756 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
757 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
758 VariableExpr newExpr( *i, nameExpr->get_argName() );
759 newExpr.set_extension( nameExpr->get_extension() );
760 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
761 PRINT(
762 std::cerr << "decl is ";
763 (*i)->print( std::cerr );
764 std::cerr << std::endl;
765 std::cerr << "newExpr is ";
766 newExpr.print( std::cerr );
767 std::cerr << std::endl;
768 )
769 renameTypes( alternatives.back().expr );
770 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
771 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
772 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
773 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
774 } // if
775 } // for
776 }
777
778 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
779 alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
780 }
781
782 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
783 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
784 }
785
786 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
787 if ( sizeofExpr->get_isType() ) {
788 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
789 } else {
790 // find all alternatives for the argument to sizeof
791 AlternativeFinder finder( indexer, env );
792 finder.find( sizeofExpr->get_expr() );
793 // find the lowest cost alternative among the alternatives, otherwise ambiguous
794 AltList winners;
795 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
796 if ( winners.size() != 1 ) {
797 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
798 } // if
799 // return the lowest cost alternative for the argument
800 Alternative &choice = winners.front();
801 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
802 } // if
803 }
804
805 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
806 if ( alignofExpr->get_isType() ) {
807 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
808 } else {
809 // find all alternatives for the argument to sizeof
810 AlternativeFinder finder( indexer, env );
811 finder.find( alignofExpr->get_expr() );
812 // find the lowest cost alternative among the alternatives, otherwise ambiguous
813 AltList winners;
814 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
815 if ( winners.size() != 1 ) {
816 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
817 } // if
818 // return the lowest cost alternative for the argument
819 Alternative &choice = winners.front();
820 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
821 } // if
822 }
823
824 template< typename StructOrUnionType >
825 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
826 std::list< Declaration* > members;
827 aggInst->lookup( name, members );
828 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
829 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
830 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt->clone() ), env, Cost::zero ) );
831 renameTypes( alternatives.back().expr );
832 } else {
833 assert( false );
834 }
835 }
836 }
837
838 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
839 AlternativeFinder funcFinder( indexer, env );
840 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
841 addOffsetof( structInst, offsetofExpr->get_member() );
842 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
843 addOffsetof( unionInst, offsetofExpr->get_member() );
844 }
845 }
846
847 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
848 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
849 }
850
851 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
852 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
853 }
854
855 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
856 // assume no polymorphism
857 // assume no implicit conversions
858 assert( function->get_parameters().size() == 1 );
859 PRINT(
860 std::cerr << "resolvAttr: funcDecl is ";
861 funcDecl->print( std::cerr );
862 std::cerr << " argType is ";
863 argType->print( std::cerr );
864 std::cerr << std::endl;
865 )
866 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
867 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
868 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
869 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
870 } // for
871 } // if
872 }
873
874 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
875 // assume no 'pointer-to-attribute'
876 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
877 assert( nameExpr );
878 std::list< DeclarationWithType* > attrList;
879 indexer.lookupId( nameExpr->get_name(), attrList );
880 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
881 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
882 // check if the type is function
883 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
884 // assume exactly one parameter
885 if ( function->get_parameters().size() == 1 ) {
886 if ( attrExpr->get_isType() ) {
887 resolveAttr( *i, function, attrExpr->get_type(), env );
888 } else {
889 AlternativeFinder finder( indexer, env );
890 finder.find( attrExpr->get_expr() );
891 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
892 if ( choice->expr->get_results().size() == 1 ) {
893 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
894 } // fi
895 } // for
896 } // if
897 } // if
898 } // if
899 } // for
900 } else {
901 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
902 VariableExpr newExpr( *i );
903 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
904 renameTypes( alternatives.back().expr );
905 } // for
906 } // if
907 }
908
909 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
910 AlternativeFinder firstFinder( indexer, env );
911 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
912 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
913 AlternativeFinder secondFinder( indexer, first->env );
914 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
915 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
916 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
917 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
918 }
919 }
920 }
921
922 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
923 AlternativeFinder firstFinder( indexer, env );
924 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
925 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
926 AlternativeFinder secondFinder( indexer, first->env );
927 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
928 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
929 AlternativeFinder thirdFinder( indexer, second->env );
930 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
931 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
932 OpenVarSet openVars;
933 AssertionSet needAssertions, haveAssertions;
934 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
935 std::list< Type* > commonTypes;
936 if ( unifyList( second->expr->get_results().begin(), second->expr->get_results().end(), third->expr->get_results().begin(), third->expr->get_results().end(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
937 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
938 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
939 std::list< Type* >::const_iterator commonType = commonTypes.begin();
940 for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
941 if ( *commonType ) {
942 newExpr->get_results().push_back( *commonType );
943 } else {
944 newExpr->get_results().push_back( (*original)->clone() );
945 } // if
946 } // for
947 newAlt.expr = newExpr;
948 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
949 } // if
950 } // for
951 } // for
952 } // for
953 }
954
955 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
956 TypeEnvironment newEnv( env );
957 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
958 AlternativeFinder secondFinder( indexer, newEnv );
959 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
960 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
961 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
962 } // for
963 delete newFirstArg;
964 }
965
966 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
967 std::list< AlternativeFinder > subExprAlternatives;
968 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
969 std::list< AltList > possibilities;
970 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
971 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
972 TupleExpr *newExpr = new TupleExpr;
973 makeExprList( *i, newExpr->get_exprs() );
974 for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
975 for ( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
976 newExpr->get_results().push_back( (*resultType)->clone() );
977 } // for
978 } // for
979
980 TypeEnvironment compositeEnv;
981 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
982 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
983 } // for
984 }
985
986 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
987 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
988 }
989} // namespace ResolvExpr
990
991// Local Variables: //
992// tab-width: 4 //
993// mode: c++ //
994// compile-command: "make install" //
995// End: //
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