source: translator/ResolvExpr/AlternativeFinder.cc@ c8ffe20b

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 c8ffe20b was 51b73452, checked in by Peter A. Buhr <pabuhr@…>, 11 years ago

initial commit
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1/*
2 * This file is part of the Cforall project
3 *
4 * $Id: AlternativeFinder.cc,v 1.36 2005/08/29 20:14:15 rcbilson Exp $
5 *
6 */
7
8#include <list>
9#include <iterator>
10#include <algorithm>
11#include <functional>
12#include <cassert>
13
14#include "AlternativeFinder.h"
15#include "Alternative.h"
16#include "Cost.h"
17#include "typeops.h"
18#include "Unify.h"
19#include "RenameVars.h"
20#include "SynTree/Type.h"
21#include "SynTree/Declaration.h"
22#include "SynTree/Expression.h"
23#include "SynTree/Initializer.h"
24#include "SynTree/Visitor.h"
25#include "SymTab/Indexer.h"
26#include "SymTab/Mangler.h"
27#include "SynTree/TypeSubstitution.h"
28#include "SymTab/Validate.h"
29#include "Designators/Processor.h"
30#include "Tuples/TupleAssignment.h"
31#include "Tuples/NameMatcher.h"
32#include "utility.h"
33
34
35//#define DEBUG_COST
36
37namespace ResolvExpr {
38
39Expression *
40resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env )
41{
42 CastExpr *castToVoid = new CastExpr( expr );
43
44 AlternativeFinder finder( indexer, env );
45 finder.findWithAdjustment( castToVoid );
46
47 // it's a property of the language that a cast expression has either 1 or 0 interpretations;
48 // if it has 0 interpretations, an exception has already been thrown.
49 assert( finder.get_alternatives().size() == 1 );
50 CastExpr *newExpr = dynamic_cast< CastExpr* >( finder.get_alternatives().front().expr );
51 assert( newExpr );
52 env = finder.get_alternatives().front().env;
53 return newExpr->get_arg()->clone();
54}
55
56namespace {
57
58 void
59 printAlts( const AltList &list, std::ostream &os, int indent = 0 )
60 {
61 for( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
62 i->print( os, indent );
63 os << std::endl;
64 }
65 }
66
67 void
68 makeExprList( const AltList &in, std::list< Expression* > &out )
69 {
70 for( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
71 out.push_back( i->expr->clone() );
72 }
73 }
74
75 Cost
76 sumCost( const AltList &in )
77 {
78 Cost total;
79 for( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
80 total += i->cost;
81 }
82 return total;
83 }
84
85 struct PruneStruct
86 {
87 bool isAmbiguous;
88 AltList::iterator candidate;
89 PruneStruct() {}
90 PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
91 };
92
93 template< typename InputIterator, typename OutputIterator >
94 void
95 pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer )
96 {
97 // select the alternatives that have the minimum conversion cost for a particular set of result types
98 std::map< std::string, PruneStruct > selected;
99 for( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
100 PruneStruct current( candidate );
101 std::string mangleName;
102 for( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
103 Type *newType = (*retType)->clone();
104 candidate->env.apply( newType );
105 mangleName += SymTab::Mangler::mangle( newType );
106 delete newType;
107 }
108 std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
109 if( mapPlace != selected.end() ) {
110 if( candidate->cost < mapPlace->second.candidate->cost ) {
111/// std::cout << "cost " << candidate->cost << " beats " << target->second.cost << std::endl;
112 selected[ mangleName ] = current;
113 } else if( candidate->cost == mapPlace->second.candidate->cost ) {
114/// std::cout << "marking ambiguous" << std::endl;
115 mapPlace->second.isAmbiguous = true;
116 }
117 } else {
118 selected[ mangleName ] = current;
119 }
120 }
121
122/// std::cout << "there are " << selected.size() << " alternatives before elimination" << std::endl;
123
124 // accept the alternatives that were unambiguous
125 for( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target) {
126 if( !target->second.isAmbiguous ) {
127 Alternative &alt = *target->second.candidate;
128 for( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
129 alt.env.applyFree( *result );
130 }
131 *out++ = alt;
132 }
133 }
134
135 }
136
137 template< typename InputIterator, typename OutputIterator >
138 void
139 findMinCost( InputIterator begin, InputIterator end, OutputIterator out )
140 {
141 AltList alternatives;
142
143 // select the alternatives that have the minimum parameter cost
144 Cost minCost = Cost::infinity;
145 for( AltList::iterator i = begin; i != end; ++i ) {
146 if( i->cost < minCost ) {
147 minCost = i->cost;
148 i->cost = i->cvtCost;
149 alternatives.clear();
150 alternatives.push_back( *i );
151 } else if( i->cost == minCost ) {
152 i->cost = i->cvtCost;
153 alternatives.push_back( *i );
154 }
155 }
156 std::copy( alternatives.begin(), alternatives.end(), out );
157 }
158
159 template< typename InputIterator >
160 void
161 simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result )
162 {
163 while( begin != end ) {
164 result.simpleCombine( (*begin++).env );
165 }
166 }
167
168 void
169 renameTypes( Expression *expr )
170 {
171 for( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
172 (*i)->accept( global_renamer );
173 }
174 }
175}
176
177template< typename InputIterator, typename OutputIterator >
178void
179AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out )
180{
181 while( begin != end ) {
182 AlternativeFinder finder( indexer, env );
183 finder.findWithAdjustment( *begin );
184 // XXX either this
185 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
186 // or XXX this
187 begin++;
188/// std::cout << "findSubExprs" << std::endl;
189/// printAlts( finder.alternatives, std::cout );
190 *out++ = finder;
191 }
192}
193
194AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
195 : indexer( indexer ), env( env )
196{
197}
198
199void
200AlternativeFinder::find( Expression *expr, bool adjust )
201{
202 expr->accept( *this );
203 if( alternatives.empty() ) {
204 throw SemanticError( "No reasonable alternatives for expression ", expr );
205 }
206 for( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
207 if( adjust ) {
208 adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
209 }
210 }
211/// std::cout << "alternatives before prune:" << std::endl;
212/// printAlts( alternatives, std::cout );
213 AltList::iterator oldBegin = alternatives.begin();
214 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
215 if( alternatives.begin() == oldBegin ) {
216 std::ostrstream 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( std::string( stream.str(), stream.pcount() ) );
224 }
225 alternatives.erase( oldBegin, alternatives.end() );
226/// std::cout << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
227}
228
229void
230AlternativeFinder::findWithAdjustment( Expression *expr )
231{
232 find( expr, true );
233}
234
235template< typename StructOrUnionType >
236void
237AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const std::string &name )
238{
239 std::list< Declaration* > members;
240 aggInst->lookup( name, members );
241 for( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
242 if( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
243 alternatives.push_back( Alternative( new MemberExpr( dwt->clone(), expr->clone() ), env, newCost ) );
244 renameTypes( alternatives.back().expr );
245 } else {
246 assert( false );
247 }
248 }
249}
250
251void
252AlternativeFinder::visit(ApplicationExpr *applicationExpr)
253{
254 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
255}
256
257Cost
258computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer )
259{
260 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( alt.expr );
261 assert( appExpr );
262 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
263 assert( pointer );
264 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
265 assert( function );
266
267 Cost convCost( 0, 0, 0 );
268 std::list< DeclarationWithType* >& formals = function->get_parameters();
269 std::list< DeclarationWithType* >::iterator formal = formals.begin();
270 std::list< Expression* >& actuals = appExpr->get_args();
271 for( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
272/// std::cout << "actual expression:" << std::endl;
273/// (*actualExpr)->print( std::cout, 8 );
274/// std::cout << "--- results are" << std::endl;
275/// printAll( (*actualExpr)->get_results(), std::cout, 8 );
276 std::list< DeclarationWithType* >::iterator startFormal = formal;
277 Cost actualCost;
278 for( std::list< Type* >::iterator actual = (*actualExpr)->get_results().begin(); actual != (*actualExpr)->get_results().end(); ++actual ) {
279 if( formal == formals.end() ) {
280 if( function->get_isVarArgs() ) {
281 convCost += Cost( 1, 0, 0 );
282 break;
283 } else {
284 return Cost::infinity;
285 }
286 }
287/// std::cout << std::endl << "converting ";
288/// (*actual)->print( std::cout, 8 );
289/// std::cout << std::endl << " to ";
290/// (*formal)->get_type()->print( std::cout, 8 );
291 Cost newCost = conversionCost( *actual, (*formal)->get_type(), indexer, alt.env );
292/// std::cout << std::endl << "cost is" << newCost << std::endl;
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/// std::cout << std::endl << "converting ";
329/// assert->second.actualType->print( std::cout, 8 );
330/// std::cout << std::endl << " to ";
331/// assert->second.formalType->print( std::cout, 8 );
332 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
333/// std::cout << std::endl << "cost of conversion is " << newCost << std::endl;
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
345void
346makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions )
347{
348 for( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
349 unifiableVars[ (*tyvar)->get_name() ] = (*tyvar)->get_kind();
350 for( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
351 needAssertions[ *assert ] = true;
352 }
353/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
354 }
355}
356
357bool
358AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /*const*/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave )
359{
360 std::list< TypeEnvironment > toBeDone;
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/// std::cerr << "formal type is ";
383/// (*formal)->get_type()->print( std::cerr );
384/// std::cerr << std::endl << "actual type is ";
385/// (*actual)->print( std::cerr );
386/// std::cerr << std::endl;
387 if( !unify( (*formal)->get_type(), *actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
388 return false;
389 }
390 formal++;
391 }
392 }
393 // Handling of default values
394 while( formal != formals.end() ) {
395 if( ObjectDecl *od = dynamic_cast<ObjectDecl *>( *formal ) )
396 if( SingleInit *si = dynamic_cast<SingleInit *>( od->get_init() ))
397 // so far, only constant expressions are accepted as default values
398 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>(si->get_value()) )
399 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) )
400 if( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
401 // XXX Don't know if this is right
402 actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
403 formal++;
404 if (formal == formals.end()) break;
405 }
406 return false;
407 }
408 return true;
409}
410
411static const int recursionLimit = 10;
412
413void
414addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer )
415{
416 for( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
417 if( i->second == true ) {
418 i->first->accept( indexer );
419 }
420 }
421}
422
423template< typename ForwardIterator, typename OutputIterator >
424void
425inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, int level, const SymTab::Indexer &indexer, OutputIterator out )
426{
427 if( begin == end ) {
428 if( newNeed.empty() ) {
429 *out++ = newAlt;
430 return;
431 } else if( level >= recursionLimit ) {
432 throw SemanticError( "Too many recursive assertions" );
433 } else {
434 AssertionSet newerNeed;
435/// std::cerr << "recursing with new set:" << std::endl;
436/// printAssertionSet( newNeed, std::cerr, 8 );
437 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, level+1, indexer, out );
438 return;
439 }
440 }
441
442 ForwardIterator cur = begin++;
443 if( !cur->second ) {
444 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, level, indexer, out );
445 }
446 DeclarationWithType *curDecl = cur->first;
447/// std::cerr << "inferRecursive: assertion is ";
448/// curDecl->print( std::cerr );
449/// std::cerr << std::endl;
450 std::list< DeclarationWithType* > candidates;
451 decls.lookupId( curDecl->get_name(), candidates );
452/// if( candidates.empty() ) { std::cout << "no candidates!" << std::endl; }
453 for( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
454/// std::cout << "inferRecursive: candidate is ";
455/// (*candidate)->print( std::cout );
456/// std::cout << std::endl;
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/// 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 if( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
469/// std::cerr << "success!" << std::endl;
470 SymTab::Indexer newDecls( decls );
471 addToIndexer( newHave, newDecls );
472 Alternative newerAlt( newAlt );
473 newerAlt.env = newEnv;
474 assert( (*candidate)->get_uniqueId() );
475 Expression *varExpr = new VariableExpr( static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) ) );
476 deleteAll( varExpr->get_results() );
477 varExpr->get_results().clear();
478 varExpr->get_results().push_front( adjType->clone() );
479/// std::cout << "satisfying assertion " << curDecl->get_uniqueId() << " ";
480/// curDecl->print( std::cout );
481/// std::cout << " with declaration " << (*candidate)->get_uniqueId() << " ";
482/// (*candidate)->print( std::cout );
483/// std::cout << std::endl;
484 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
485 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
486 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
487 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, level, indexer, out );
488 } else {
489 delete adjType;
490 }
491 }
492}
493
494template< typename OutputIterator >
495void
496AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out )
497{
498/// std::cout << "inferParameters: assertions needed are" << std::endl;
499/// printAll( need, std::cout, 8 );
500 SymTab::Indexer decls( indexer );
501/// std::cout << "============= original indexer" << std::endl;
502/// indexer.print( std::cout );
503/// std::cout << "============= new indexer" << std::endl;
504/// decls.print( std::cout );
505 addToIndexer( have, decls );
506 AssertionSet newNeed;
507 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, 0, indexer, out );
508/// std::cout << "declaration 14 is ";
509/// Declaration::declFromId
510/// *out++ = newAlt;
511}
512
513template< typename OutputIterator >
514void
515AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out )
516{
517 OpenVarSet openVars;
518 AssertionSet resultNeed, resultHave;
519 TypeEnvironment resultEnv;
520 makeUnifiableVars( funcType, openVars, resultNeed );
521 if( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
522 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
523 Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
524 makeExprList( actualAlt, appExpr->get_args() );
525/// std::cout << "need assertions:" << std::endl;
526/// printAssertionSet( resultNeed, std::cout, 8 );
527 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
528 }
529}
530
531void
532AlternativeFinder::visit(UntypedExpr *untypedExpr)
533{
534 bool doneInit = false;
535 AlternativeFinder funcOpFinder( indexer, env );
536
537 AlternativeFinder funcFinder( indexer, env );
538 {
539 NameExpr *fname;
540 if ( (fname = dynamic_cast<NameExpr *>(untypedExpr->get_function()))
541 && ( fname->get_name() == std::string("LabAddress")) ) {
542 alternatives.push_back( Alternative(untypedExpr, env, Cost()) );
543 return;
544 }
545 }
546
547 funcFinder.findWithAdjustment( untypedExpr->get_function() );
548 std::list< AlternativeFinder > argAlternatives;
549 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
550
551 std::list< AltList > possibilities;
552 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
553
554 Tuples::TupleAssignSpotter tassign(this);
555 if ( tassign.isTupleAssignment(untypedExpr, possibilities) ) {
556 // take care of possible tuple assignments, or discard expression
557 return;
558 } // else ...
559
560 AltList candidates;
561
562 for( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
563/// std::cout << "working on alternative: " << std::endl;
564/// func->print( std::cout, 8 );
565 // check if the type is pointer to function
566 PointerType *pointer;
567 if( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
568 if( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
569 for( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
570 // XXX
571 //Designators::check_alternative( function, *actualAlt );
572 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
573 }
574 } else if( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
575 EqvClass eqvClass;
576 if( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
577 if( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
578 for( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
579 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
580 }
581 }
582 }
583 }
584 } else {
585 // seek a function operator that's compatible
586 if( !doneInit ) {
587 doneInit = true;
588 NameExpr *opExpr = new NameExpr( "?()" );
589 try {
590 funcOpFinder.findWithAdjustment( opExpr );
591 } catch( SemanticError &e ) {
592 // it's ok if there aren't any defined function ops
593 }
594/// std::cout << "known function ops:" << std::endl;
595/// printAlts( funcOpFinder.alternatives, std::cout, 8 );
596 }
597
598 for( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
599 // check if the type is pointer to function
600 PointerType *pointer;
601 if( funcOp->expr->get_results().size() == 1
602 && ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
603 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
604 for( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
605 AltList currentAlt;
606 currentAlt.push_back( *func );
607 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
608 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
609 }
610 }
611 }
612 }
613 }
614 }
615
616 for( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
617 Cost cvtCost = computeConversionCost( *withFunc, indexer );
618
619#ifdef DEBUG_COST
620 ApplicationExpr *appExpr = dynamic_cast< ApplicationExpr* >( withFunc->expr );
621 assert( appExpr );
622 PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
623 assert( pointer );
624 FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
625 assert( function );
626 std::cout << "Case +++++++++++++" << std::endl;
627 std::cout << "formals are:" << std::endl;
628 printAll( function->get_parameters(), std::cout, 8 );
629 std::cout << "actuals are:" << std::endl;
630 printAll( appExpr->get_args(), std::cout, 8 );
631 std::cout << "bindings are:" << std::endl;
632 withFunc->env.print( std::cout, 8 );
633 std::cout << "cost of conversion is:" << cvtCost << std::endl;
634#endif
635
636 if( cvtCost != Cost::infinity ) {
637 withFunc->cvtCost = cvtCost;
638 alternatives.push_back( *withFunc );
639 }
640 }
641 candidates.clear();
642 candidates.splice( candidates.end(), alternatives );
643
644 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
645}
646
647bool
648isLvalue( Expression *expr ) {
649 for( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
650 if( !(*i)->get_isLvalue() ) return false;
651 }
652 return true;
653}
654
655void
656AlternativeFinder::visit(AddressExpr *addressExpr)
657{
658 AlternativeFinder finder( indexer, env );
659 finder.find( addressExpr->get_arg() );
660 for( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
661 if( isLvalue( i->expr ) ) {
662 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
663 }
664 }
665}
666
667void
668AlternativeFinder::visit(CastExpr *castExpr)
669{
670 for( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
671 SymTab::validateType( *i, &indexer );
672 adjustExprType( *i, env, indexer );
673 }
674
675 AlternativeFinder finder( indexer, env );
676 finder.findWithAdjustment( castExpr->get_arg() );
677
678 AltList candidates;
679 for( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
680 AssertionSet needAssertions, haveAssertions;
681 OpenVarSet openVars;
682
683 // It's possible that a cast can throw away some values in a multiply-valued expression.
684 // (An example is a cast-to-void, which casts from one value to zero.)
685 // Figure out the prefix of the subexpression results that are cast directly.
686 // The candidate is invalid if it has fewer results than there are types to cast to.
687 int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
688 if( discardedValues < 0 ) continue;
689 std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
690 std::advance( candidate_end, castExpr->get_results().size() );
691 if( !unifyList( (*i).expr->get_results().begin(), candidate_end,
692 castExpr->get_results().begin(), castExpr->get_results().end(), i->env, needAssertions, haveAssertions, openVars, indexer ) ) continue;
693 Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
694 castExpr->get_results().begin(), castExpr->get_results().end(), indexer, i->env );
695 if( thisCost != Cost::infinity ) {
696 // count one safe conversion for each value that is thrown away
697 thisCost += Cost( 0, 0, discardedValues );
698 CastExpr *newExpr = castExpr->clone();
699 newExpr->set_arg( i->expr->clone() );
700 candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
701 }
702 }
703
704 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect
705 // of copying the cvtCost member to the cost member (since the old cost is now irrelevant).
706 // Thus, calling findMinCost twice selects first based on argument cost, then on conversion cost.
707 AltList minArgCost;
708 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
709 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
710}
711
712void
713AlternativeFinder::visit(UntypedMemberExpr *memberExpr)
714{
715 AlternativeFinder funcFinder( indexer, env );
716 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
717
718 for( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
719 if( agg->expr->get_results().size() == 1 ) {
720 if( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_results().front() ) ) {
721 addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
722 } else if( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_results().front() ) ) {
723 addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
724 }
725 }
726 }
727}
728
729void
730AlternativeFinder::visit(MemberExpr *memberExpr)
731{
732 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
733}
734
735void
736AlternativeFinder::visit(NameExpr *nameExpr)
737{
738 std::list< DeclarationWithType* > declList;
739 indexer.lookupId( nameExpr->get_name(), declList );
740/// std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl;
741 for( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
742 VariableExpr newExpr( *i, nameExpr->get_argName() );
743 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
744/// std::cerr << "decl is ";
745/// (*i)->print( std::cerr );
746/// std::cerr << std::endl;
747/// std::cerr << "newExpr is ";
748/// newExpr.print( std::cerr );
749/// std::cerr << std::endl;
750 renameTypes( alternatives.back().expr );
751 if( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
752 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
753 } else if( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
754 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
755 }
756 }
757}
758
759void
760AlternativeFinder::visit(VariableExpr *variableExpr)
761{
762 alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
763}
764
765void
766AlternativeFinder::visit(ConstantExpr *constantExpr)
767{
768 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
769}
770
771void
772AlternativeFinder::visit(SizeofExpr *sizeofExpr)
773{
774 if( sizeofExpr->get_isType() ) {
775 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
776 } else {
777 AlternativeFinder finder( indexer, env );
778 finder.find( sizeofExpr->get_expr() );
779 if( finder.alternatives.size() != 1 ) {
780 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
781 }
782 Alternative &choice = finder.alternatives.front();
783 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
784 }
785}
786
787void
788AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env )
789{
790 // assume no polymorphism
791 // assume no implicit conversions
792 assert( function->get_parameters().size() == 1 );
793/// std::cout << "resolvAttr: funcDecl is ";
794/// funcDecl->print( std::cout );
795/// std::cout << " argType is ";
796/// argType->print( std::cout );
797/// std::cout << std::endl;
798 if( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
799 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
800 for( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
801 alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
802 }
803 }
804}
805
806void
807AlternativeFinder::visit(AttrExpr *attrExpr)
808{
809 // assume no 'pointer-to-attribute'
810 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
811 assert( nameExpr );
812 std::list< DeclarationWithType* > attrList;
813 indexer.lookupId( nameExpr->get_name(), attrList );
814 if( attrExpr->get_isType() || attrExpr->get_expr() ) {
815 for( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
816 // check if the type is function
817 if( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
818 // assume exactly one parameter
819 if( function->get_parameters().size() == 1 ) {
820 if( attrExpr->get_isType() ) {
821 resolveAttr( *i, function, attrExpr->get_type(), env );
822 } else {
823 AlternativeFinder finder( indexer, env );
824 finder.find( attrExpr->get_expr() );
825 for( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
826 if( choice->expr->get_results().size() == 1 ) {
827 resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
828 }
829 }
830 }
831 }
832 }
833 }
834 } else {
835 for( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
836 VariableExpr newExpr( *i );
837 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
838 renameTypes( alternatives.back().expr );
839 }
840 }
841}
842
843void
844AlternativeFinder::visit(LogicalExpr *logicalExpr)
845{
846 AlternativeFinder firstFinder( indexer, env );
847 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
848 for( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
849 AlternativeFinder secondFinder( indexer, first->env );
850 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
851 for( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
852 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
853 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
854 }
855 }
856}
857
858void
859AlternativeFinder::visit(ConditionalExpr *conditionalExpr)
860{
861 AlternativeFinder firstFinder( indexer, env );
862 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
863 for( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
864 AlternativeFinder secondFinder( indexer, first->env );
865 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
866 for( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
867 AlternativeFinder thirdFinder( indexer, second->env );
868 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
869 for( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
870 OpenVarSet openVars;
871 AssertionSet needAssertions, haveAssertions;
872 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
873 std::list< Type* > commonTypes;
874 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 ) ) {
875 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
876 std::list< Type* >::const_iterator original = second->expr->get_results().begin();
877 std::list< Type* >::const_iterator commonType = commonTypes.begin();
878 for( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
879 if( *commonType ) {
880 newExpr->get_results().push_back( *commonType );
881 } else {
882 newExpr->get_results().push_back( (*original)->clone() );
883 }
884 }
885 newAlt.expr = newExpr;
886 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
887 }
888 }
889 }
890 }
891}
892
893void
894AlternativeFinder::visit(CommaExpr *commaExpr)
895{
896 TypeEnvironment newEnv( env );
897 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
898 AlternativeFinder secondFinder( indexer, newEnv );
899 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
900 for( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
901 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
902 }
903 delete newFirstArg;
904}
905
906void
907AlternativeFinder::visit(TupleExpr *tupleExpr)
908{
909 std::list< AlternativeFinder > subExprAlternatives;
910 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
911 std::list< AltList > possibilities;
912 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
913 for( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
914 TupleExpr *newExpr = new TupleExpr;
915 makeExprList( *i, newExpr->get_exprs() );
916 for( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
917 for( std::list< Type* >::const_iterator resultType = (*resultExpr)->get_results().begin(); resultType != (*resultExpr)->get_results().end(); ++resultType ) {
918 newExpr->get_results().push_back( (*resultType)->clone() );
919 }
920 }
921
922 TypeEnvironment compositeEnv;
923 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
924 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
925 }
926}
927
928} // namespace ResolvExpr
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