source: src/ResolvExpr/AlternativeFinder.cc@ 5aa708c

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 string with_gc
Last change on this file since 5aa708c was 2871210, checked in by Peter A. Buhr <pabuhr@…>, 10 years ago

include file with keywords, fix type of label address expressions, fix computed goto to any expressions, generic types first attempt
  • Property mode set to 100644
File size: 38.3 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 : Fri Jul 3 17:58:39 2015
13// Update Count : 22
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 "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::cout << "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::cout << "marking ambiguous" << std::endl;
115 )
116 mapPlace->second.isAmbiguous = true;
117 }
118 } else {
119 selected[ mangleName ] = current;
120 }
121 }
122
123 PRINT(
124 std::cout << "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::cout << "findSubExprs" << std::endl;
185 printAlts( finder.alternatives, std::cout );
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::cout << "alternatives before prune:" << std::endl;
207 printAlts( alternatives, std::cout );
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::cout << "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::cout << "actual expression:" << std::endl;
264 (*actualExpr)->print( std::cout, 8 );
265 std::cout << "--- results are" << std::endl;
266 printAll( (*actualExpr)->get_results(), std::cout, 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::cout << std::endl << "converting ";
281 (*actual)->print( std::cout, 8 );
282 std::cout << std::endl << " to ";
283 (*formal)->get_type()->print( std::cout, 8 );
284 )
285 Cost newCost = conversionCost( *actual, (*formal)->get_type(), indexer, alt.env );
286 PRINT(
287 std::cout << 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::cout << std::endl << "converting ";
326 assert->second.actualType->print( std::cout, 8 );
327 std::cout << std::endl << " to ";
328 assert->second.formalType->print( std::cout, 8 );
329 )
330 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
331 PRINT(
332 std::cout << 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 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
346 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
347 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
348 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
349 needAssertions[ *assert ] = true;
350 }
351/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
352 }
353 }
354
355 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
356 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
357 // make sure we don't widen any existing bindings
358 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
359 i->allowWidening = false;
360 }
361 resultEnv.extractOpenVars( openVars );
362
363 /*
364 Tuples::NameMatcher matcher( formals );
365 try {
366 matcher.match( actuals );
367 } catch ( Tuples::NoMatch &e ) {
368 std::cerr << "Alternative doesn't match: " << e.message << std::endl;
369 }
370 */
371 std::list< DeclarationWithType* >::iterator formal = formals.begin();
372 for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
373 for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
374 if ( formal == formals.end() ) {
375 return isVarArgs;
376 }
377 PRINT(
378 std::cerr << "formal type is ";
379 (*formal)->get_type()->print( std::cerr );
380 std::cerr << std::endl << "actual type is ";
381 (*actual)->print( std::cerr );
382 std::cerr << std::endl;
383 )
384 if ( ! unify( (*formal)->get_type(), *actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
385 return false;
386 }
387 formal++;
388 }
389 }
390 // Handling of default values
391 while ( formal != formals.end() ) {
392 if ( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
393 if ( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
394 // so far, only constant expressions are accepted as default values
395 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) )
396 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
397 if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
398 // XXX Don't know if this is right
399 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
400 formal++;
401 if ( formal == formals.end()) break;
402 }
403 return false;
404 }
405 return true;
406 }
407
408 static const int recursionLimit = 10;
409
410 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
411 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
412 if ( i->second == true ) {
413 i->first->accept( indexer );
414 }
415 }
416 }
417
418 template< typename ForwardIterator, typename OutputIterator >
419 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 ) {
420 if ( begin == end ) {
421 if ( newNeed.empty() ) {
422 *out++ = newAlt;
423 return;
424 } else if ( level >= recursionLimit ) {
425 throw SemanticError( "Too many recursive assertions" );
426 } else {
427 AssertionSet newerNeed;
428 PRINT(
429 std::cerr << "recursing with new set:" << std::endl;
430 printAssertionSet( newNeed, std::cerr, 8 );
431 )
432 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, level+1, indexer, out );
433 return;
434 }
435 }
436
437 ForwardIterator cur = begin++;
438 if ( ! cur->second ) {
439 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, level, indexer, out );
440 }
441 DeclarationWithType *curDecl = cur->first;
442 PRINT(
443 std::cerr << "inferRecursive: assertion is ";
444 curDecl->print( std::cerr );
445 std::cerr << std::endl;
446 )
447 std::list< DeclarationWithType* > candidates;
448 decls.lookupId( curDecl->get_name(), candidates );
449/// if ( candidates.empty() ) { std::cout << "no candidates!" << std::endl; }
450 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
451 PRINT(
452 std::cout << "inferRecursive: candidate is ";
453 (*candidate)->print( std::cout );
454 std::cout << std::endl;
455 )
456 AssertionSet newHave, newerNeed( newNeed );
457 TypeEnvironment newEnv( newAlt.env );
458 OpenVarSet newOpenVars( openVars );
459 Type *adjType = (*candidate)->get_type()->clone();
460 adjustExprType( adjType, newEnv, indexer );
461 adjType->accept( global_renamer );
462 PRINT(
463 std::cerr << "unifying ";
464 curDecl->get_type()->print( std::cerr );
465 std::cerr << " with ";
466 adjType->print( std::cerr );
467 std::cerr << std::endl;
468 )
469 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
470 PRINT(
471 std::cerr << "success!" << std::endl;
472 )
473 SymTab::Indexer newDecls( decls );
474 addToIndexer( newHave, newDecls );
475 Alternative newerAlt( newAlt );
476 newerAlt.env = newEnv;
477 assert( (*candidate)->get_uniqueId() );
478 Expression *varExpr = new VariableExpr( static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) ) );
479 deleteAll( varExpr->get_results() );
480 varExpr->get_results().clear();
481 varExpr->get_results().push_front( adjType->clone() );
482 PRINT(
483 std::cout << "satisfying assertion " << curDecl->get_uniqueId() << " ";
484 curDecl->print( std::cout );
485 std::cout << " with declaration " << (*candidate)->get_uniqueId() << " ";
486 (*candidate)->print( std::cout );
487 std::cout << std::endl;
488 )
489 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
490 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
491 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
492 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, level, indexer, out );
493 } else {
494 delete adjType;
495 }
496 }
497 }
498
499 template< typename OutputIterator >
500 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
501// PRINT(
502// std::cout << "inferParameters: assertions needed are" << std::endl;
503// printAll( need, std::cout, 8 );
504// )
505 SymTab::Indexer decls( indexer );
506 PRINT(
507 std::cout << "============= original indexer" << std::endl;
508 indexer.print( std::cout );
509 std::cout << "============= new indexer" << std::endl;
510 decls.print( std::cout );
511 )
512 addToIndexer( have, decls );
513 AssertionSet newNeed;
514 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, 0, indexer, out );
515// PRINT(
516// std::cout << "declaration 14 is ";
517// Declaration::declFromId
518// *out++ = newAlt;
519// )
520 }
521
522 template< typename OutputIterator >
523 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
524 OpenVarSet openVars;
525 AssertionSet resultNeed, resultHave;
526 TypeEnvironment resultEnv;
527 makeUnifiableVars( funcType, openVars, resultNeed );
528 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
529 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
530 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
531 makeExprList( actualAlt, appExpr->get_args() );
532 PRINT(
533 std::cout << "need assertions:" << std::endl;
534 printAssertionSet( resultNeed, std::cout, 8 );
535 )
536 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
537 }
538 }
539
540 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
541 bool doneInit = false;
542 AlternativeFinder funcOpFinder( indexer, env );
543
544 AlternativeFinder funcFinder( indexer, env ); {
545 NameExpr *fname = 0;;
546 if ( ( fname = dynamic_cast<NameExpr *>( untypedExpr->get_function()))
547 && ( fname->get_name() == std::string("&&")) ) {
548 VoidType v = Type::Qualifiers(); // resolve to type void *
549 PointerType pt( Type::Qualifiers(), v.clone() );
550 UntypedExpr *vexpr = untypedExpr->clone();
551 vexpr->get_results().push_front( pt.clone() );
552 alternatives.push_back( Alternative( vexpr, env, Cost()) );
553 return;
554 }
555 }
556
557 funcFinder.findWithAdjustment( untypedExpr->get_function() );
558 std::list< AlternativeFinder > argAlternatives;
559 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
560
561 std::list< AltList > possibilities;
562 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
563
564 Tuples::TupleAssignSpotter tassign( this );
565 if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
566 // take care of possible tuple assignments, or discard expression
567 return;
568 } // else ...
569
570 AltList candidates;
571
572 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
573 PRINT(
574 std::cout << "working on alternative: " << std::endl;
575 func->print( std::cout, 8 );
576 )
577 // check if the type is pointer to function
578 PointerType *pointer;
579 if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
580 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
581 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
582 // XXX
583 //Designators::check_alternative( function, *actualAlt );
584 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
585 }
586 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
587 EqvClass eqvClass;
588 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
589 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
590 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
591 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
592 } // for
593 } // if
594 } // if
595 } // if
596 } else {
597 // seek a function operator that's compatible
598 if ( ! doneInit ) {
599 doneInit = true;
600 NameExpr *opExpr = new NameExpr( "?()" );
601 try {
602 funcOpFinder.findWithAdjustment( opExpr );
603 } catch( SemanticError &e ) {
604 // it's ok if there aren't any defined function ops
605 }
606 PRINT(
607 std::cout << "known function ops:" << std::endl;
608 printAlts( funcOpFinder.alternatives, std::cout, 8 );
609 )
610 }
611
612 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
613 // check if the type is pointer to function
614 PointerType *pointer;
615 if ( funcOp->expr->get_results().size() == 1
616 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
617 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
618 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
619 AltList currentAlt;
620 currentAlt.push_back( *func );
621 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
622 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
623 } // for
624 } // if
625 } // if
626 } // for
627 } // if
628 } // for
629
630 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
631 Cost cvtCost = computeConversionCost( *withFunc, indexer );
632
633 PRINT(
634 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
635 assert( appExpr );
636 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
637 assert( pointer );
638 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
639 assert( function );
640 std::cout << "Case +++++++++++++" << std::endl;
641 std::cout << "formals are:" << std::endl;
642 printAll( function->get_parameters(), std::cout, 8 );
643 std::cout << "actuals are:" << std::endl;
644 printAll( appExpr->get_args(), std::cout, 8 );
645 std::cout << "bindings are:" << std::endl;
646 withFunc->env.print( std::cout, 8 );
647 std::cout << "cost of conversion is:" << cvtCost << std::endl;
648 )
649 if ( cvtCost != Cost::infinity ) {
650 withFunc->cvtCost = cvtCost;
651 alternatives.push_back( *withFunc );
652 } // if
653 } // for
654 candidates.clear();
655 candidates.splice( candidates.end(), alternatives );
656
657 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
658 }
659
660 bool isLvalue( Expression *expr ) {
661 for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
662 if ( !(*i)->get_isLvalue() ) return false;
663 } // for
664 return true;
665 }
666
667 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
668 AlternativeFinder finder( indexer, env );
669 finder.find( addressExpr->get_arg() );
670 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
671 if ( isLvalue( i->expr ) ) {
672 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
673 } // if
674 } // for
675 }
676
677 void AlternativeFinder::visit( CastExpr *castExpr ) {
678 for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
679 SymTab::validateType( *i, &indexer );
680 adjustExprType( *i, env, indexer );
681 } // for
682
683 AlternativeFinder finder( indexer, env );
684 finder.findWithAdjustment( castExpr->get_arg() );
685
686 AltList candidates;
687 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
688 AssertionSet needAssertions, haveAssertions;
689 OpenVarSet openVars;
690
691 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
692 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
693 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
694 // to.
695 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
696 if ( discardedValues < 0 ) continue;
697 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
698 std::advance( candidate_end, castExpr->get_results().size() );
699 if ( ! unifyList( (*i).expr->get_results().begin(), candidate_end,
700 castExpr->get_results().begin(), castExpr->get_results().end(), i->env, needAssertions, haveAssertions, openVars, indexer ) ) continue;
701 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
702 castExpr->get_results().begin(), castExpr->get_results().end(), indexer, i->env );
703 if ( thisCost != Cost::infinity ) {
704 // count one safe conversion for each value that is thrown away
705 thisCost += Cost( 0, 0, discardedValues );
706 CastExpr *newExpr = castExpr->clone();
707 newExpr->set_arg( i->expr->clone() );
708 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
709 } // if
710 } // for
711
712 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
713 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
714 // selects first based on argument cost, then on conversion cost.
715 AltList minArgCost;
716 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
717 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
718 }
719
720 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
721 AlternativeFinder funcFinder( indexer, env );
722 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
723
724 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
725 if ( agg->expr->get_results().size() == 1 ) {
726 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
727 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
728 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
729 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
730 } // if
731 } // if
732 } // for
733 }
734
735 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
736 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
737 }
738
739 void AlternativeFinder::visit( NameExpr *nameExpr ) {
740 std::list< DeclarationWithType* > declList;
741 indexer.lookupId( nameExpr->get_name(), declList );
742 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
743 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
744 VariableExpr newExpr( *i, nameExpr->get_argName() );
745 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
746 PRINT(
747 std::cerr << "decl is ";
748 (*i)->print( std::cerr );
749 std::cerr << std::endl;
750 std::cerr << "newExpr is ";
751 newExpr.print( std::cerr );
752 std::cerr << std::endl;
753 )
754 renameTypes( alternatives.back().expr );
755 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
756 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
757 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
758 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
759 } // if
760 } // for
761 }
762
763 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
764 alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
765 }
766
767 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
768 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
769 }
770
771 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
772 if ( sizeofExpr->get_isType() ) {
773 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
774 } else {
775 // find all alternatives for the argument to sizeof
776 AlternativeFinder finder( indexer, env );
777 finder.find( sizeofExpr->get_expr() );
778 // find the lowest cost alternative among the alternatives, otherwise ambiguous
779 AltList winners;
780 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
781 if ( winners.size() != 1 ) {
782 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
783 } // if
784 // return the lowest cost alternative for the argument
785 Alternative &choice = winners.front();
786 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
787 } // if
788 }
789
790 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
791 // assume no polymorphism
792 // assume no implicit conversions
793 assert( function->get_parameters().size() == 1 );
794 PRINT(
795 std::cout << "resolvAttr: funcDecl is ";
796 funcDecl->print( std::cout );
797 std::cout << " argType is ";
798 argType->print( std::cout );
799 std::cout << std::endl;
800 )
801 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
802 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
803 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
804 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
805 } // for
806 } // if
807 }
808
809 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
810 // assume no 'pointer-to-attribute'
811 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
812 assert( nameExpr );
813 std::list< DeclarationWithType* > attrList;
814 indexer.lookupId( nameExpr->get_name(), attrList );
815 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
816 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
817 // check if the type is function
818 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
819 // assume exactly one parameter
820 if ( function->get_parameters().size() == 1 ) {
821 if ( attrExpr->get_isType() ) {
822 resolveAttr( *i, function, attrExpr->get_type(), env );
823 } else {
824 AlternativeFinder finder( indexer, env );
825 finder.find( attrExpr->get_expr() );
826 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
827 if ( choice->expr->get_results().size() == 1 ) {
828 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
829 } // fi
830 } // for
831 } // if
832 } // if
833 } // if
834 } // for
835 } else {
836 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
837 VariableExpr newExpr( *i );
838 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
839 renameTypes( alternatives.back().expr );
840 } // for
841 } // if
842 }
843
844 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
845 AlternativeFinder firstFinder( indexer, env );
846 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
847 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
848 AlternativeFinder secondFinder( indexer, first->env );
849 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
850 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
851 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
852 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
853 }
854 }
855 }
856
857 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
858 AlternativeFinder firstFinder( indexer, env );
859 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
860 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
861 AlternativeFinder secondFinder( indexer, first->env );
862 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
863 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
864 AlternativeFinder thirdFinder( indexer, second->env );
865 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
866 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
867 OpenVarSet openVars;
868 AssertionSet needAssertions, haveAssertions;
869 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
870 std::list< Type* > commonTypes;
871 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 ) ) {
872 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
873 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
874 std::list< Type* >::const_iterator commonType = commonTypes.begin();
875 for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
876 if ( *commonType ) {
877 newExpr->get_results().push_back( *commonType );
878 } else {
879 newExpr->get_results().push_back( (*original)->clone() );
880 } // if
881 } // for
882 newAlt.expr = newExpr;
883 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
884 } // if
885 } // for
886 } // for
887 } // for
888 }
889
890 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
891 TypeEnvironment newEnv( env );
892 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
893 AlternativeFinder secondFinder( indexer, newEnv );
894 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
895 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
896 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
897 } // for
898 delete newFirstArg;
899 }
900
901 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
902 std::list< AlternativeFinder > subExprAlternatives;
903 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
904 std::list< AltList > possibilities;
905 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
906 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
907 TupleExpr *newExpr = new TupleExpr;
908 makeExprList( *i, newExpr->get_exprs() );
909 for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
910 for ( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
911 newExpr->get_results().push_back( (*resultType)->clone() );
912 } // for
913 } // for
914
915 TypeEnvironment compositeEnv;
916 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
917 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
918 } // for
919 }
920} // namespace ResolvExpr
921
922// Local Variables: //
923// tab-width: 4 //
924// mode: c++ //
925// compile-command: "make install" //
926// End: //
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