source: src/ResolvExpr/AlternativeFinder.cc@ d06010a

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 d06010a was 22cad76, checked in by Aaron Moss <a3moss@…>, 9 years ago

Second attempt to break resolver loop
  • Property mode set to 100644
File size: 42.0 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#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 "Designators/Processor.h"
41#include "Tuples/TupleAssignment.h"
42#include "Tuples/NameMatcher.h"
43#include "Common/utility.h"
44#include "InitTweak/InitTweak.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
231 void AlternativeFinder::findWithAdjustment( Expression *expr ) {
232 find( expr, true );
233 }
234
235 template< typename StructOrUnionType >
236 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const std::string &name ) {
237 std::list< Declaration* > members;
238 aggInst->lookup( name, members );
239 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
240 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
241 alternatives.push_back( Alternative( new MemberExpr( dwt->clone(), expr->clone() ), env, newCost ) );
242 renameTypes( alternatives.back().expr );
243 } else {
244 assert( false );
245 }
246 }
247 }
248
249 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
250 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
251 }
252
253 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
254 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( alt.expr );
255 assert( appExpr );
256 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
257 assert( pointer );
258 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
259 assert( function );
260
261 Cost convCost( 0, 0, 0 );
262 std::list< DeclarationWithType* >& formals = function->get_parameters();
263 std::list< DeclarationWithType* >::iterator formal = formals.begin();
264 std::list< Expression* >& actuals = appExpr->get_args();
265 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
266 PRINT(
267 std::cerr << "actual expression:" << std::endl;
268 (*actualExpr)->print( std::cerr, 8 );
269 std::cerr << "--- results are" << std::endl;
270 printAll( (*actualExpr)->get_results(), std::cerr, 8 );
271 )
272 std::list< DeclarationWithType* >::iterator startFormal = formal;
273 Cost actualCost;
274 for ( std::list< Type* >::iterator actual = (*actualExpr)->get_results().begin(); actual != (*actualExpr)->get_results().end(); ++actual ) {
275 if ( formal == formals.end() ) {
276 if ( function->get_isVarArgs() ) {
277 convCost += Cost( 1, 0, 0 );
278 break;
279 } else {
280 return Cost::infinity;
281 }
282 }
283 PRINT(
284 std::cerr << std::endl << "converting ";
285 (*actual)->print( std::cerr, 8 );
286 std::cerr << std::endl << " to ";
287 (*formal)->get_type()->print( std::cerr, 8 );
288 )
289 Cost newCost = conversionCost( *actual, (*formal)->get_type(), indexer, alt.env );
290 PRINT(
291 std::cerr << std::endl << "cost is" << newCost << std::endl;
292 )
293
294 if ( newCost == Cost::infinity ) {
295 return newCost;
296 }
297 convCost += newCost;
298 actualCost += newCost;
299
300 convCost += Cost( 0, polyCost( (*formal)->get_type(), alt.env, indexer ) + polyCost( *actual, alt.env, indexer ), 0 );
301
302 formal++;
303 }
304 if ( actualCost != Cost( 0, 0, 0 ) ) {
305 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
306 startFormalPlusOne++;
307 if ( formal == startFormalPlusOne ) {
308 // not a tuple type
309 Type *newType = (*startFormal)->get_type()->clone();
310 alt.env.apply( newType );
311 *actualExpr = new CastExpr( *actualExpr, newType );
312 } else {
313 TupleType *newType = new TupleType( Type::Qualifiers() );
314 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
315 newType->get_types().push_back( (*i)->get_type()->clone() );
316 }
317 alt.env.apply( newType );
318 *actualExpr = new CastExpr( *actualExpr, newType );
319 }
320 }
321
322 }
323 if ( formal != formals.end() ) {
324 return Cost::infinity;
325 }
326
327 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
328 PRINT(
329 std::cerr << std::endl << "converting ";
330 assert->second.actualType->print( std::cerr, 8 );
331 std::cerr << std::endl << " to ";
332 assert->second.formalType->print( std::cerr, 8 );
333 )
334 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
335 PRINT(
336 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
337 )
338 if ( newCost == Cost::infinity ) {
339 return newCost;
340 }
341 convCost += newCost;
342
343 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
344 }
345
346 return convCost;
347 }
348
349 /// Adds type variables to the open variable set and marks their assertions
350 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
351 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
352 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
353 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
354 needAssertions[ *assert ] = true;
355 }
356/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
357 }
358 }
359
360 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
361 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
362 // make sure we don't widen any existing bindings
363 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
364 i->allowWidening = false;
365 }
366 resultEnv.extractOpenVars( openVars );
367
368 /*
369 Tuples::NameMatcher matcher( formals );
370 try {
371 matcher.match( actuals );
372 } catch ( Tuples::NoMatch &e ) {
373 std::cerr << "Alternative doesn't match: " << e.message << std::endl;
374 }
375 */
376 std::list< DeclarationWithType* >::iterator formal = formals.begin();
377 for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
378 for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
379 if ( formal == formals.end() ) {
380 return isVarArgs;
381 }
382 PRINT(
383 std::cerr << "formal type is ";
384 (*formal)->get_type()->print( std::cerr );
385 std::cerr << std::endl << "actual type is ";
386 (*actual)->print( std::cerr );
387 std::cerr << std::endl;
388 )
389 if ( ! unify( (*formal)->get_type(), *actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
390 return false;
391 }
392 formal++;
393 }
394 }
395 // Handling of default values
396 while ( formal != formals.end() ) {
397 if ( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
398 if ( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
399 // so far, only constant expressions are accepted as default values
400 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) )
401 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
402 if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
403 // XXX Don't know if this is right
404 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
405 formal++;
406 if ( formal == formals.end()) break;
407 }
408 return false;
409 }
410 return true;
411 }
412
413 /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
414 typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
415
416 static const int recursionLimit = 10; ///< Limit to depth of recursion satisfaction
417 static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
418
419 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
420 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
421 if ( i->second == true ) {
422 i->first->accept( indexer );
423 }
424 }
425 }
426
427 template< typename ForwardIterator, typename OutputIterator >
428 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, const AssertionParentSet &needParents,
429 int level, const SymTab::Indexer &indexer, OutputIterator out ) {
430 if ( begin == end ) {
431 if ( newNeed.empty() ) {
432 *out++ = newAlt;
433 return;
434 } else if ( level >= recursionLimit ) {
435 throw SemanticError( "Too many recursive assertions" );
436 } else {
437 AssertionSet newerNeed;
438 PRINT(
439 std::cerr << "recursing with new set:" << std::endl;
440 printAssertionSet( newNeed, std::cerr, 8 );
441 )
442 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, needParents, level+1, indexer, out );
443 return;
444 }
445 }
446
447 ForwardIterator cur = begin++;
448 if ( ! cur->second ) {
449 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, needParents, level, indexer, out );
450 }
451 DeclarationWithType *curDecl = cur->first;
452 PRINT(
453 std::cerr << "inferRecursive: assertion is ";
454 curDecl->print( std::cerr );
455 std::cerr << std::endl;
456 )
457 std::list< DeclarationWithType* > candidates;
458 decls.lookupId( curDecl->get_name(), candidates );
459/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
460 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
461 PRINT(
462 std::cerr << "inferRecursive: candidate is ";
463 (*candidate)->print( std::cerr );
464 std::cerr << std::endl;
465 )
466
467 AssertionSet newHave, newerNeed( newNeed );
468 TypeEnvironment newEnv( newAlt.env );
469 OpenVarSet newOpenVars( openVars );
470 Type *adjType = (*candidate)->get_type()->clone();
471 adjustExprType( adjType, newEnv, indexer );
472 adjType->accept( global_renamer );
473 PRINT(
474 std::cerr << "unifying ";
475 curDecl->get_type()->print( std::cerr );
476 std::cerr << " with ";
477 adjType->print( std::cerr );
478 std::cerr << std::endl;
479 )
480 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
481 PRINT(
482 std::cerr << "success!" << std::endl;
483 )
484 SymTab::Indexer newDecls( decls );
485 addToIndexer( newHave, newDecls );
486 Alternative newerAlt( newAlt );
487 newerAlt.env = newEnv;
488 assert( (*candidate)->get_uniqueId() );
489 DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
490 AssertionParentSet newNeedParents( needParents );
491 // skip repeatingly-self-recursive assertion satisfaction
492 if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
493 Expression *varExpr = new VariableExpr( candDecl );
494 deleteAll( varExpr->get_results() );
495 varExpr->get_results().clear();
496 varExpr->get_results().push_front( adjType->clone() );
497 PRINT(
498 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
499 curDecl->print( std::cerr );
500 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
501 (*candidate)->print( std::cerr );
502 std::cerr << std::endl;
503 )
504 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
505 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
506 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
507 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, newNeedParents, level, indexer, out );
508 } else {
509 delete adjType;
510 }
511 }
512 }
513
514 template< typename OutputIterator >
515 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
516// PRINT(
517// std::cerr << "inferParameters: assertions needed are" << std::endl;
518// printAll( need, std::cerr, 8 );
519// )
520 SymTab::Indexer decls( indexer );
521 PRINT(
522 std::cerr << "============= original indexer" << std::endl;
523 indexer.print( std::cerr );
524 std::cerr << "============= new indexer" << std::endl;
525 decls.print( std::cerr );
526 )
527 addToIndexer( have, decls );
528 AssertionSet newNeed;
529 AssertionParentSet needParents;
530 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, needParents, 0, indexer, out );
531// PRINT(
532// std::cerr << "declaration 14 is ";
533// Declaration::declFromId
534// *out++ = newAlt;
535// )
536 }
537
538 template< typename OutputIterator >
539 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
540 OpenVarSet openVars;
541 AssertionSet resultNeed, resultHave;
542 TypeEnvironment resultEnv;
543 makeUnifiableVars( funcType, openVars, resultNeed );
544 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
545 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
546 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
547 makeExprList( actualAlt, appExpr->get_args() );
548 PRINT(
549 std::cerr << "need assertions:" << std::endl;
550 printAssertionSet( resultNeed, std::cerr, 8 );
551 )
552 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
553 }
554 }
555
556 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
557 bool doneInit = false;
558 AlternativeFinder funcOpFinder( indexer, env );
559
560 AlternativeFinder funcFinder( indexer, env );
561
562 {
563 std::string fname = InitTweak::getFunctionName( untypedExpr );
564 if ( fname == "&&" ) {
565 VoidType v = Type::Qualifiers(); // resolve to type void *
566 PointerType pt( Type::Qualifiers(), v.clone() );
567 UntypedExpr *vexpr = untypedExpr->clone();
568 vexpr->get_results().push_front( pt.clone() );
569 alternatives.push_back( Alternative( vexpr, env, Cost()) );
570 return;
571 }
572 }
573
574 funcFinder.findWithAdjustment( untypedExpr->get_function() );
575 std::list< AlternativeFinder > argAlternatives;
576 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
577
578 std::list< AltList > possibilities;
579 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
580
581 Tuples::TupleAssignSpotter tassign( this );
582 if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
583 // take care of possible tuple assignments, or discard expression
584 return;
585 } // else ...
586
587 AltList candidates;
588 SemanticError errors;
589
590 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
591 try {
592 PRINT(
593 std::cerr << "working on alternative: " << std::endl;
594 func->print( std::cerr, 8 );
595 )
596 // check if the type is pointer to function
597 PointerType *pointer;
598 if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
599 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
600 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
601 // XXX
602 //Designators::check_alternative( function, *actualAlt );
603 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
604 }
605 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
606 EqvClass eqvClass;
607 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
608 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
609 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
610 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
611 } // for
612 } // if
613 } // if
614 } // if
615 } else {
616 // seek a function operator that's compatible
617 if ( ! doneInit ) {
618 doneInit = true;
619 NameExpr *opExpr = new NameExpr( "?()" );
620 try {
621 funcOpFinder.findWithAdjustment( opExpr );
622 } catch( SemanticError &e ) {
623 // it's ok if there aren't any defined function ops
624 }
625 PRINT(
626 std::cerr << "known function ops:" << std::endl;
627 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
628 )
629 }
630
631 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
632 // check if the type is pointer to function
633 PointerType *pointer;
634 if ( funcOp->expr->get_results().size() == 1
635 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
636 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
637 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
638 AltList currentAlt;
639 currentAlt.push_back( *func );
640 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
641 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
642 } // for
643 } // if
644 } // if
645 } // for
646 } // if
647 } catch ( SemanticError &e ) {
648 errors.append( e );
649 }
650 } // for
651
652 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
653 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
654
655 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
656 Cost cvtCost = computeConversionCost( *withFunc, indexer );
657
658 PRINT(
659 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
660 assert( appExpr );
661 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
662 assert( pointer );
663 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
664 assert( function );
665 std::cerr << "Case +++++++++++++" << std::endl;
666 std::cerr << "formals are:" << std::endl;
667 printAll( function->get_parameters(), std::cerr, 8 );
668 std::cerr << "actuals are:" << std::endl;
669 printAll( appExpr->get_args(), std::cerr, 8 );
670 std::cerr << "bindings are:" << std::endl;
671 withFunc->env.print( std::cerr, 8 );
672 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
673 )
674 if ( cvtCost != Cost::infinity ) {
675 withFunc->cvtCost = cvtCost;
676 alternatives.push_back( *withFunc );
677 } // if
678 } // for
679 candidates.clear();
680 candidates.splice( candidates.end(), alternatives );
681
682 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
683 }
684
685 bool isLvalue( Expression *expr ) {
686 for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
687 if ( !(*i)->get_isLvalue() ) return false;
688 } // for
689 return true;
690 }
691
692 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
693 AlternativeFinder finder( indexer, env );
694 finder.find( addressExpr->get_arg() );
695 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
696 if ( isLvalue( i->expr ) ) {
697 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
698 } // if
699 } // for
700 }
701
702 void AlternativeFinder::visit( CastExpr *castExpr ) {
703 for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
704 SymTab::validateType( *i, &indexer );
705 adjustExprType( *i, env, indexer );
706 } // for
707
708 AlternativeFinder finder( indexer, env );
709 finder.findWithAdjustment( castExpr->get_arg() );
710
711 AltList candidates;
712 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
713 AssertionSet needAssertions, haveAssertions;
714 OpenVarSet openVars;
715
716 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
717 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
718 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
719 // to.
720 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
721 if ( discardedValues < 0 ) continue;
722 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
723 std::advance( candidate_end, castExpr->get_results().size() );
724 // unification run for side-effects
725 unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
726 (*i).expr->get_results().begin(), candidate_end,
727 i->env, needAssertions, haveAssertions, openVars, indexer );
728 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
729 castExpr->get_results().begin(), castExpr->get_results().end(),
730 indexer, i->env );
731 if ( thisCost != Cost::infinity ) {
732 // count one safe conversion for each value that is thrown away
733 thisCost += Cost( 0, 0, discardedValues );
734 CastExpr *newExpr = castExpr->clone();
735 newExpr->set_arg( i->expr->clone() );
736 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
737 } // if
738 } // for
739
740 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
741 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
742 // selects first based on argument cost, then on conversion cost.
743 AltList minArgCost;
744 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
745 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
746 }
747
748 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
749 AlternativeFinder funcFinder( indexer, env );
750 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
751
752 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
753 if ( agg->expr->get_results().size() == 1 ) {
754 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
755 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
756 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
757 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
758 } // if
759 } // if
760 } // for
761 }
762
763 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
764 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
765 }
766
767 void AlternativeFinder::visit( NameExpr *nameExpr ) {
768 std::list< DeclarationWithType* > declList;
769 indexer.lookupId( nameExpr->get_name(), declList );
770 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
771 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
772 VariableExpr newExpr( *i, nameExpr->get_argName() );
773 newExpr.set_extension( nameExpr->get_extension() );
774 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
775 PRINT(
776 std::cerr << "decl is ";
777 (*i)->print( std::cerr );
778 std::cerr << std::endl;
779 std::cerr << "newExpr is ";
780 newExpr.print( std::cerr );
781 std::cerr << std::endl;
782 )
783 renameTypes( alternatives.back().expr );
784 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
785 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
786 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
787 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
788 } // if
789 } // for
790 }
791
792 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
793 alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
794 }
795
796 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
797 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
798 }
799
800 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
801 if ( sizeofExpr->get_isType() ) {
802 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
803 } else {
804 // find all alternatives for the argument to sizeof
805 AlternativeFinder finder( indexer, env );
806 finder.find( sizeofExpr->get_expr() );
807 // find the lowest cost alternative among the alternatives, otherwise ambiguous
808 AltList winners;
809 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
810 if ( winners.size() != 1 ) {
811 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
812 } // if
813 // return the lowest cost alternative for the argument
814 Alternative &choice = winners.front();
815 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
816 } // if
817 }
818
819 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
820 if ( alignofExpr->get_isType() ) {
821 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
822 } else {
823 // find all alternatives for the argument to sizeof
824 AlternativeFinder finder( indexer, env );
825 finder.find( alignofExpr->get_expr() );
826 // find the lowest cost alternative among the alternatives, otherwise ambiguous
827 AltList winners;
828 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
829 if ( winners.size() != 1 ) {
830 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
831 } // if
832 // return the lowest cost alternative for the argument
833 Alternative &choice = winners.front();
834 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
835 } // if
836 }
837
838 template< typename StructOrUnionType >
839 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
840 std::list< Declaration* > members;
841 aggInst->lookup( name, members );
842 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
843 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
844 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt->clone() ), env, Cost::zero ) );
845 renameTypes( alternatives.back().expr );
846 } else {
847 assert( false );
848 }
849 }
850 }
851
852 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
853 AlternativeFinder funcFinder( indexer, env );
854 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
855 addOffsetof( structInst, offsetofExpr->get_member() );
856 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
857 addOffsetof( unionInst, offsetofExpr->get_member() );
858 }
859 }
860
861 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
862 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
863 }
864
865 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
866 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
867 }
868
869 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
870 // assume no polymorphism
871 // assume no implicit conversions
872 assert( function->get_parameters().size() == 1 );
873 PRINT(
874 std::cerr << "resolvAttr: funcDecl is ";
875 funcDecl->print( std::cerr );
876 std::cerr << " argType is ";
877 argType->print( std::cerr );
878 std::cerr << std::endl;
879 )
880 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
881 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
882 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
883 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
884 } // for
885 } // if
886 }
887
888 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
889 // assume no 'pointer-to-attribute'
890 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
891 assert( nameExpr );
892 std::list< DeclarationWithType* > attrList;
893 indexer.lookupId( nameExpr->get_name(), attrList );
894 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
895 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
896 // check if the type is function
897 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
898 // assume exactly one parameter
899 if ( function->get_parameters().size() == 1 ) {
900 if ( attrExpr->get_isType() ) {
901 resolveAttr( *i, function, attrExpr->get_type(), env );
902 } else {
903 AlternativeFinder finder( indexer, env );
904 finder.find( attrExpr->get_expr() );
905 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
906 if ( choice->expr->get_results().size() == 1 ) {
907 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
908 } // fi
909 } // for
910 } // if
911 } // if
912 } // if
913 } // for
914 } else {
915 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
916 VariableExpr newExpr( *i );
917 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
918 renameTypes( alternatives.back().expr );
919 } // for
920 } // if
921 }
922
923 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
924 AlternativeFinder firstFinder( indexer, env );
925 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
926 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
927 AlternativeFinder secondFinder( indexer, first->env );
928 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
929 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
930 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
931 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
932 }
933 }
934 }
935
936 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
937 AlternativeFinder firstFinder( indexer, env );
938 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
939 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
940 AlternativeFinder secondFinder( indexer, first->env );
941 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
942 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
943 AlternativeFinder thirdFinder( indexer, second->env );
944 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
945 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
946 OpenVarSet openVars;
947 AssertionSet needAssertions, haveAssertions;
948 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
949 std::list< Type* > commonTypes;
950 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 ) ) {
951 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
952 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
953 std::list< Type* >::const_iterator commonType = commonTypes.begin();
954 for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
955 if ( *commonType ) {
956 newExpr->get_results().push_back( *commonType );
957 } else {
958 newExpr->get_results().push_back( (*original)->clone() );
959 } // if
960 } // for
961 newAlt.expr = newExpr;
962 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
963 } // if
964 } // for
965 } // for
966 } // for
967 }
968
969 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
970 TypeEnvironment newEnv( env );
971 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
972 AlternativeFinder secondFinder( indexer, newEnv );
973 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
974 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
975 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
976 } // for
977 delete newFirstArg;
978 }
979
980 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
981 std::list< AlternativeFinder > subExprAlternatives;
982 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
983 std::list< AltList > possibilities;
984 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
985 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
986 TupleExpr *newExpr = new TupleExpr;
987 makeExprList( *i, newExpr->get_exprs() );
988 for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
989 for ( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
990 newExpr->get_results().push_back( (*resultType)->clone() );
991 } // for
992 } // for
993
994 TypeEnvironment compositeEnv;
995 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
996 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
997 } // for
998 }
999
1000 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1001 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1002 }
1003} // namespace ResolvExpr
1004
1005// Local Variables: //
1006// tab-width: 4 //
1007// mode: c++ //
1008// compile-command: "make install" //
1009// End: //
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