source: src/ResolvExpr/AlternativeFinder.cc@ e33f321

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since e33f321 was 722617d, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

resolve StmtExprs
  • Property mode set to 100644
File size: 48.6 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// AlternativeFinder.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sat May 16 23:52:08 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Jul 4 17:02:51 2016
13// Update Count : 29
14//
15
16#include <list>
17#include <iterator>
18#include <algorithm>
19#include <functional>
20#include <cassert>
21#include <unordered_map>
22#include <utility>
23#include <vector>
24
25#include "AlternativeFinder.h"
26#include "Alternative.h"
27#include "Cost.h"
28#include "typeops.h"
29#include "Unify.h"
30#include "RenameVars.h"
31#include "SynTree/Type.h"
32#include "SynTree/Declaration.h"
33#include "SynTree/Expression.h"
34#include "SynTree/Initializer.h"
35#include "SynTree/Visitor.h"
36#include "SymTab/Indexer.h"
37#include "SymTab/Mangler.h"
38#include "SynTree/TypeSubstitution.h"
39#include "SymTab/Validate.h"
40#include "Tuples/Tuples.h"
41#include "Tuples/Explode.h"
42#include "Common/utility.h"
43#include "InitTweak/InitTweak.h"
44#include "InitTweak/GenInit.h"
45#include "ResolveTypeof.h"
46#include "Resolver.h"
47
48extern bool resolvep;
49#define PRINT( text ) if ( resolvep ) { text }
50//#define DEBUG_COST
51
52namespace ResolvExpr {
53 Expression *resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
54 CastExpr *castToVoid = new CastExpr( expr );
55
56 AlternativeFinder finder( indexer, env );
57 finder.findWithAdjustment( castToVoid );
58
59 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
60 // interpretations, an exception has already been thrown.
61 assert( finder.get_alternatives().size() == 1 );
62 CastExpr *newExpr = dynamic_cast< CastExpr* >( finder.get_alternatives().front().expr );
63 assert( newExpr );
64 env = finder.get_alternatives().front().env;
65 return newExpr->get_arg()->clone();
66 }
67
68 Cost sumCost( const AltList &in ) {
69 Cost total;
70 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
71 total += i->cost;
72 }
73 return total;
74 }
75
76 namespace {
77 void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
78 for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
79 i->print( os, indent );
80 os << std::endl;
81 }
82 }
83
84 void makeExprList( const AltList &in, std::list< Expression* > &out ) {
85 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
86 out.push_back( i->expr->clone() );
87 }
88 }
89
90 struct PruneStruct {
91 bool isAmbiguous;
92 AltList::iterator candidate;
93 PruneStruct() {}
94 PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
95 };
96
97 /// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
98 template< typename InputIterator, typename OutputIterator >
99 void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
100 // select the alternatives that have the minimum conversion cost for a particular set of result types
101 std::map< std::string, PruneStruct > selected;
102 for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
103 PruneStruct current( candidate );
104 std::string mangleName;
105 {
106 Type * newType = candidate->expr->get_result()->clone();
107 candidate->env.apply( newType );
108 mangleName = SymTab::Mangler::mangle( newType );
109 delete newType;
110 }
111 std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
112 if ( mapPlace != selected.end() ) {
113 if ( candidate->cost < mapPlace->second.candidate->cost ) {
114 PRINT(
115 std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
116 )
117 selected[ mangleName ] = current;
118 } else if ( candidate->cost == mapPlace->second.candidate->cost ) {
119 PRINT(
120 std::cerr << "marking ambiguous" << std::endl;
121 )
122 mapPlace->second.isAmbiguous = true;
123 }
124 } else {
125 selected[ mangleName ] = current;
126 }
127 }
128
129 PRINT(
130 std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
131 )
132
133 // accept the alternatives that were unambiguous
134 for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
135 if ( ! target->second.isAmbiguous ) {
136 Alternative &alt = *target->second.candidate;
137 alt.env.applyFree( alt.expr->get_result() );
138 *out++ = alt;
139 }
140 }
141 }
142
143 void renameTypes( Expression *expr ) {
144 expr->get_result()->accept( global_renamer );
145 }
146 }
147
148 template< typename InputIterator, typename OutputIterator >
149 void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
150 while ( begin != end ) {
151 AlternativeFinder finder( indexer, env );
152 finder.findWithAdjustment( *begin );
153 // XXX either this
154 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
155 // or XXX this
156 begin++;
157 PRINT(
158 std::cerr << "findSubExprs" << std::endl;
159 printAlts( finder.alternatives, std::cerr );
160 )
161 *out++ = finder;
162 }
163 }
164
165 AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
166 : indexer( indexer ), env( env ) {
167 }
168
169 void AlternativeFinder::find( Expression *expr, bool adjust, bool prune ) {
170 expr->accept( *this );
171 if ( alternatives.empty() ) {
172 throw SemanticError( "No reasonable alternatives for expression ", expr );
173 }
174 for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
175 if ( adjust ) {
176 adjustExprType( i->expr->get_result(), i->env, indexer );
177 }
178 }
179 if ( prune ) {
180 PRINT(
181 std::cerr << "alternatives before prune:" << std::endl;
182 printAlts( alternatives, std::cerr );
183 )
184 AltList::iterator oldBegin = alternatives.begin();
185 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
186 if ( alternatives.begin() == oldBegin ) {
187 std::ostringstream stream;
188 stream << "Can't choose between " << alternatives.size() << " alternatives for expression ";
189 expr->print( stream );
190 stream << "Alternatives are:";
191 AltList winners;
192 findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
193 printAlts( winners, stream, 8 );
194 throw SemanticError( stream.str() );
195 }
196 alternatives.erase( oldBegin, alternatives.end() );
197 PRINT(
198 std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
199 )
200 }
201
202 // Central location to handle gcc extension keyword for all expression types.
203 for ( Alternative &iter: alternatives ) {
204 iter.expr->set_extension( expr->get_extension() );
205 } // for
206 }
207
208 void AlternativeFinder::findWithAdjustment( Expression *expr, bool prune ) {
209 find( expr, true, prune );
210 }
211
212 // std::unordered_map< Expression *, UniqueExpr * > ;
213
214 template< typename StructOrUnionType >
215 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const TypeEnvironment & env, Expression * member ) {
216 // by this point, member must be a name expr
217 NameExpr * nameExpr = safe_dynamic_cast< NameExpr * >( member );
218 const std::string & name = nameExpr->get_name();
219 std::list< Declaration* > members;
220 aggInst->lookup( name, members );
221 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
222 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
223 alternatives.push_back( Alternative( new MemberExpr( dwt, expr->clone() ), env, newCost ) );
224 renameTypes( alternatives.back().expr );
225 } else {
226 assert( false );
227 }
228 }
229 }
230
231 void AlternativeFinder::addTupleMembers( TupleType * tupleType, Expression *expr, const Cost &newCost, const TypeEnvironment & env, Expression * member ) {
232 if ( ConstantExpr * constantExpr = dynamic_cast< ConstantExpr * >( member ) ) {
233 // get the value of the constant expression as an int, must be between 0 and the length of the tuple type to have meaning
234 // xxx - this should be improved by memoizing the value of constant exprs
235 // during parsing and reusing that information here.
236 std::stringstream ss( constantExpr->get_constant()->get_value() );
237 int val;
238 std::string tmp;
239 if ( ss >> val && ! (ss >> tmp) ) {
240 if ( val >= 0 && (unsigned int)val < tupleType->size() ) {
241 alternatives.push_back( Alternative( new TupleIndexExpr( expr->clone(), val ), env, newCost ) );
242 } // if
243 } // if
244 } else if ( NameExpr * nameExpr = dynamic_cast< NameExpr * >( member ) ) {
245 // xxx - temporary hack until 0/1 are int constants
246 if ( nameExpr->get_name() == "0" || nameExpr->get_name() == "1" ) {
247 std::stringstream ss( nameExpr->get_name() );
248 int val;
249 ss >> val;
250 alternatives.push_back( Alternative( new TupleIndexExpr( expr->clone(), val ), env, newCost ) );
251 }
252 } // if
253 }
254
255 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
256 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
257 }
258
259 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
260 ApplicationExpr *appExpr = safe_dynamic_cast< ApplicationExpr* >( alt.expr );
261 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
262 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
263
264 Cost convCost( 0, 0, 0 );
265 std::list< DeclarationWithType* >& formals = function->get_parameters();
266 std::list< DeclarationWithType* >::iterator formal = formals.begin();
267 std::list< Expression* >& actuals = appExpr->get_args();
268
269 std::list< Type * > formalTypes;
270 std::list< Type * >::iterator formalType = formalTypes.end();
271
272 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
273
274 PRINT(
275 std::cerr << "actual expression:" << std::endl;
276 (*actualExpr)->print( std::cerr, 8 );
277 std::cerr << "--- results are" << std::endl;
278 (*actualExpr)->get_result()->print( std::cerr, 8 );
279 )
280 std::list< DeclarationWithType* >::iterator startFormal = formal;
281 Cost actualCost;
282 std::list< Type * > flatActualTypes;
283 flatten( (*actualExpr)->get_result(), back_inserter( flatActualTypes ) );
284 for ( std::list< Type* >::iterator actualType = flatActualTypes.begin(); actualType != flatActualTypes.end(); ++actualType ) {
285
286
287 // tuple handling code
288 if ( formalType == formalTypes.end() ) {
289 // the type of the formal parameter may be a tuple type. To make this easier to work with,
290 // flatten the tuple type and traverse the resulting list of types, incrementing the formal
291 // iterator once its types have been extracted. Once a particular formal parameter's type has
292 // been exhausted load the next formal parameter's type.
293 if ( formal == formals.end() ) {
294 if ( function->get_isVarArgs() ) {
295 convCost += Cost( 1, 0, 0 );
296 break;
297 } else {
298 return Cost::infinity;
299 }
300 }
301 formalTypes.clear();
302 flatten( (*formal)->get_type(), back_inserter( formalTypes ) );
303 formalType = formalTypes.begin();
304 ++formal;
305 }
306
307 PRINT(
308 std::cerr << std::endl << "converting ";
309 (*actualType)->print( std::cerr, 8 );
310 std::cerr << std::endl << " to ";
311 (*formalType)->print( std::cerr, 8 );
312 )
313 Cost newCost = conversionCost( *actualType, *formalType, indexer, alt.env );
314 PRINT(
315 std::cerr << std::endl << "cost is" << newCost << std::endl;
316 )
317
318 if ( newCost == Cost::infinity ) {
319 return newCost;
320 }
321 convCost += newCost;
322 actualCost += newCost;
323
324 convCost += Cost( 0, polyCost( *formalType, alt.env, indexer ) + polyCost( *actualType, alt.env, indexer ), 0 );
325
326 formalType++;
327 }
328 if ( actualCost != Cost( 0, 0, 0 ) ) {
329 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
330 startFormalPlusOne++;
331 if ( formal == startFormalPlusOne ) {
332 // not a tuple type
333 Type *newType = (*startFormal)->get_type()->clone();
334 alt.env.apply( newType );
335 *actualExpr = new CastExpr( *actualExpr, newType );
336 } else {
337 TupleType *newType = new TupleType( Type::Qualifiers() );
338 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
339 newType->get_types().push_back( (*i)->get_type()->clone() );
340 }
341 alt.env.apply( newType );
342 *actualExpr = new CastExpr( *actualExpr, newType );
343 }
344 }
345
346 }
347 if ( formal != formals.end() ) {
348 return Cost::infinity;
349 }
350
351 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
352 PRINT(
353 std::cerr << std::endl << "converting ";
354 assert->second.actualType->print( std::cerr, 8 );
355 std::cerr << std::endl << " to ";
356 assert->second.formalType->print( std::cerr, 8 );
357 )
358 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
359 PRINT(
360 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
361 )
362 if ( newCost == Cost::infinity ) {
363 return newCost;
364 }
365 convCost += newCost;
366
367 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
368 }
369
370 return convCost;
371 }
372
373 /// Adds type variables to the open variable set and marks their assertions
374 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
375 for ( Type::ForallList::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
376 unifiableVars[ (*tyvar)->get_name() ] = TypeDecl::Data{ *tyvar };
377 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
378 needAssertions[ *assert ] = true;
379 }
380/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
381 }
382 }
383
384 /// instantiate a single argument by matching actuals from [actualIt, actualEnd) against formalType,
385 /// producing expression(s) in out and their total cost in cost.
386 template< typename AltIterator, typename OutputIterator >
387 bool instantiateArgument( Type * formalType, Initializer * defaultValue, AltIterator & actualIt, AltIterator actualEnd, OpenVarSet & openVars, TypeEnvironment & resultEnv, AssertionSet & resultNeed, AssertionSet & resultHave, const SymTab::Indexer & indexer, Cost & cost, OutputIterator out ) {
388 if ( TupleType * tupleType = dynamic_cast< TupleType * >( formalType ) ) {
389 // formalType is a TupleType - group actuals into a TupleExpr whose type unifies with the TupleType
390 TupleExpr * tupleExpr = new TupleExpr();
391 for ( Type * type : *tupleType ) {
392 if ( ! instantiateArgument( type, defaultValue, actualIt, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( tupleExpr->get_exprs() ) ) ) {
393 delete tupleExpr;
394 return false;
395 }
396 }
397 tupleExpr->set_result( Tuples::makeTupleType( tupleExpr->get_exprs() ) );
398 *out++ = tupleExpr;
399 } else if ( actualIt != actualEnd ) {
400 // both actualType and formalType are atomic (non-tuple) types - if they unify
401 // then accept actual as an argument, otherwise return false (fail to instantiate argument)
402 Expression * actual = actualIt->expr;
403 Type * actualType = actual->get_result();
404 PRINT(
405 std::cerr << "formal type is ";
406 formalType->print( std::cerr );
407 std::cerr << std::endl << "actual type is ";
408 actualType->print( std::cerr );
409 std::cerr << std::endl;
410 )
411 if ( ! unify( formalType, actualType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
412 return false;
413 }
414 // move the expression from the alternative to the output iterator
415 *out++ = actual;
416 actualIt->expr = nullptr;
417 cost += actualIt->cost;
418 ++actualIt;
419 } else {
420 // End of actuals - Handle default values
421 if ( SingleInit *si = dynamic_cast<SingleInit *>( defaultValue )) {
422 // so far, only constant expressions are accepted as default values
423 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) ) {
424 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) ) {
425 if ( unify( formalType, cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
426 // xxx - Don't know if this is right
427 *out++ = cnstexpr->clone();
428 return true;
429 } // if
430 } // if
431 } // if
432 } // if
433 return false;
434 } // if
435 return true;
436 }
437
438 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, const AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave, AltList & out ) {
439 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
440 // make sure we don't widen any existing bindings
441 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
442 i->allowWidening = false;
443 }
444 resultEnv.extractOpenVars( openVars );
445
446 // flatten actuals so that each actual has an atomic (non-tuple) type
447 AltList exploded;
448 Tuples::explode( actuals, indexer, back_inserter( exploded ) );
449
450 AltList::iterator actualExpr = exploded.begin();
451 AltList::iterator actualEnd = exploded.end();
452 for ( DeclarationWithType * formal : formals ) {
453 // match flattened actuals with formal parameters - actuals will be grouped to match
454 // with formals as appropriate
455 Cost cost;
456 std::list< Expression * > newExprs;
457 ObjectDecl * obj = safe_dynamic_cast< ObjectDecl * >( formal );
458 if ( ! instantiateArgument( obj->get_type(), obj->get_init(), actualExpr, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( newExprs ) ) ) {
459 deleteAll( newExprs );
460 return false;
461 }
462 // success - produce argument as a new alternative
463 assert( newExprs.size() == 1 );
464 out.push_back( Alternative( newExprs.front(), resultEnv, cost ) );
465 }
466 if ( actualExpr != actualEnd ) {
467 // there are still actuals remaining, but we've run out of formal parameters to match against
468 // this is okay only if the function is variadic
469 if ( ! isVarArgs ) {
470 return false;
471 }
472 out.splice( out.end(), exploded, actualExpr, actualEnd );
473 }
474 return true;
475 }
476
477 // /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
478 //typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
479
480 static const int recursionLimit = /*10*/ 4; ///< Limit to depth of recursion satisfaction
481 //static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
482
483 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
484 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
485 if ( i->second == true ) {
486 i->first->accept( indexer );
487 }
488 }
489 }
490
491 template< typename ForwardIterator, typename OutputIterator >
492 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /*const AssertionParentSet &needParents,*/
493 int level, const SymTab::Indexer &indexer, OutputIterator out ) {
494 if ( begin == end ) {
495 if ( newNeed.empty() ) {
496 *out++ = newAlt;
497 return;
498 } else if ( level >= recursionLimit ) {
499 throw SemanticError( "Too many recursive assertions" );
500 } else {
501 AssertionSet newerNeed;
502 PRINT(
503 std::cerr << "recursing with new set:" << std::endl;
504 printAssertionSet( newNeed, std::cerr, 8 );
505 )
506 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /*needParents,*/ level+1, indexer, out );
507 return;
508 }
509 }
510
511 ForwardIterator cur = begin++;
512 if ( ! cur->second ) {
513 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /*needParents,*/ level, indexer, out );
514 return; // xxx - should this continue? previously this wasn't here, and it looks like it should be
515 }
516 DeclarationWithType *curDecl = cur->first;
517
518 PRINT(
519 std::cerr << "inferRecursive: assertion is ";
520 curDecl->print( std::cerr );
521 std::cerr << std::endl;
522 )
523 std::list< DeclarationWithType* > candidates;
524 decls.lookupId( curDecl->get_name(), candidates );
525/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
526 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
527 PRINT(
528 std::cerr << "inferRecursive: candidate is ";
529 (*candidate)->print( std::cerr );
530 std::cerr << std::endl;
531 )
532
533 AssertionSet newHave, newerNeed( newNeed );
534 TypeEnvironment newEnv( newAlt.env );
535 OpenVarSet newOpenVars( openVars );
536 Type *adjType = (*candidate)->get_type()->clone();
537 adjustExprType( adjType, newEnv, indexer );
538 adjType->accept( global_renamer );
539 PRINT(
540 std::cerr << "unifying ";
541 curDecl->get_type()->print( std::cerr );
542 std::cerr << " with ";
543 adjType->print( std::cerr );
544 std::cerr << std::endl;
545 )
546 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
547 PRINT(
548 std::cerr << "success!" << std::endl;
549 )
550 SymTab::Indexer newDecls( decls );
551 addToIndexer( newHave, newDecls );
552 Alternative newerAlt( newAlt );
553 newerAlt.env = newEnv;
554 assert( (*candidate)->get_uniqueId() );
555 DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
556 //AssertionParentSet newNeedParents( needParents );
557 // skip repeatingly-self-recursive assertion satisfaction
558 // DOESN'T WORK: grandchild nodes conflict with their cousins
559 //if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
560 Expression *varExpr = new VariableExpr( candDecl );
561 delete varExpr->get_result();
562 varExpr->set_result( adjType->clone() );
563 PRINT(
564 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
565 curDecl->print( std::cerr );
566 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
567 (*candidate)->print( std::cerr );
568 std::cerr << std::endl;
569 )
570 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
571 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
572 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
573 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /*newNeedParents,*/ level, indexer, out );
574 } else {
575 delete adjType;
576 }
577 }
578 }
579
580 template< typename OutputIterator >
581 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
582// PRINT(
583// std::cerr << "inferParameters: assertions needed are" << std::endl;
584// printAll( need, std::cerr, 8 );
585// )
586 SymTab::Indexer decls( indexer );
587 PRINT(
588 std::cerr << "============= original indexer" << std::endl;
589 indexer.print( std::cerr );
590 std::cerr << "============= new indexer" << std::endl;
591 decls.print( std::cerr );
592 )
593 addToIndexer( have, decls );
594 AssertionSet newNeed;
595 //AssertionParentSet needParents;
596 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /*needParents,*/ 0, indexer, out );
597// PRINT(
598// std::cerr << "declaration 14 is ";
599// Declaration::declFromId
600// *out++ = newAlt;
601// )
602 }
603
604 template< typename OutputIterator >
605 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, const AltList &actualAlt, OutputIterator out ) {
606 OpenVarSet openVars;
607 AssertionSet resultNeed, resultHave;
608 TypeEnvironment resultEnv;
609 makeUnifiableVars( funcType, openVars, resultNeed );
610 AltList instantiatedActuals; // filled by instantiate function
611 if ( targetType && ! targetType->isVoid() ) {
612 // attempt to narrow based on expected target type
613 Type * returnType = funcType->get_returnVals().front()->get_type();
614 if ( ! unify( returnType, targetType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
615 // unification failed, don't pursue this alternative
616 return;
617 }
618 }
619
620 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave, instantiatedActuals ) ) {
621 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
622 Alternative newAlt( appExpr, resultEnv, sumCost( instantiatedActuals ) );
623 makeExprList( instantiatedActuals, appExpr->get_args() );
624 PRINT(
625 std::cerr << "need assertions:" << std::endl;
626 printAssertionSet( resultNeed, std::cerr, 8 );
627 )
628 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
629 }
630 }
631
632 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
633 bool doneInit = false;
634 AlternativeFinder funcOpFinder( indexer, env );
635
636 AlternativeFinder funcFinder( indexer, env );
637
638 {
639 std::string fname = InitTweak::getFunctionName( untypedExpr );
640 if ( fname == "&&" ) {
641 VoidType v = Type::Qualifiers(); // resolve to type void *
642 PointerType pt( Type::Qualifiers(), v.clone() );
643 UntypedExpr *vexpr = untypedExpr->clone();
644 vexpr->set_result( pt.clone() );
645 alternatives.push_back( Alternative( vexpr, env, Cost()) );
646 return;
647 }
648 }
649
650 funcFinder.findWithAdjustment( untypedExpr->get_function() );
651 std::list< AlternativeFinder > argAlternatives;
652 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
653
654 std::list< AltList > possibilities;
655 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
656
657 // take care of possible tuple assignments
658 // if not tuple assignment, assignment is taken care of as a normal function call
659 Tuples::handleTupleAssignment( *this, untypedExpr, possibilities );
660
661 AltList candidates;
662 SemanticError errors;
663 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
664 try {
665 PRINT(
666 std::cerr << "working on alternative: " << std::endl;
667 func->print( std::cerr, 8 );
668 )
669 // check if the type is pointer to function
670 PointerType *pointer;
671 if ( ( pointer = dynamic_cast< PointerType* >( func->expr->get_result() ) ) ) {
672 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
673 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
674 // XXX
675 //Designators::check_alternative( function, *actualAlt );
676 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
677 }
678 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
679 EqvClass eqvClass;
680 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
681 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
682 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
683 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
684 } // for
685 } // if
686 } // if
687 } // if
688 } else {
689 // seek a function operator that's compatible
690 if ( ! doneInit ) {
691 doneInit = true;
692 NameExpr *opExpr = new NameExpr( "?()" );
693 try {
694 funcOpFinder.findWithAdjustment( opExpr );
695 } catch( SemanticError &e ) {
696 // it's ok if there aren't any defined function ops
697 }
698 PRINT(
699 std::cerr << "known function ops:" << std::endl;
700 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
701 )
702 }
703
704 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
705 // check if the type is pointer to function
706 PointerType *pointer;
707 if ( ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_result() ) ) ) {
708 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
709 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
710 AltList currentAlt;
711 currentAlt.push_back( *func );
712 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
713 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
714 } // for
715 } // if
716 } // if
717 } // for
718 } // if
719 } catch ( SemanticError &e ) {
720 errors.append( e );
721 }
722 } // for
723
724 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
725 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
726
727 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
728 Cost cvtCost = computeConversionCost( *withFunc, indexer );
729
730 PRINT(
731 ApplicationExpr *appExpr = safe_dynamic_cast< ApplicationExpr* >( withFunc->expr );
732 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
733 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
734 std::cerr << "Case +++++++++++++" << std::endl;
735 std::cerr << "formals are:" << std::endl;
736 printAll( function->get_parameters(), std::cerr, 8 );
737 std::cerr << "actuals are:" << std::endl;
738 printAll( appExpr->get_args(), std::cerr, 8 );
739 std::cerr << "bindings are:" << std::endl;
740 withFunc->env.print( std::cerr, 8 );
741 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
742 )
743 if ( cvtCost != Cost::infinity ) {
744 withFunc->cvtCost = cvtCost;
745 alternatives.push_back( *withFunc );
746 } // if
747 } // for
748 candidates.clear();
749 candidates.splice( candidates.end(), alternatives );
750
751 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
752
753 if ( alternatives.empty() && targetType && ! targetType->isVoid() ) {
754 // xxx - this is a temporary hack. If resolution is unsuccessful with a target type, try again without a
755 // target type, since it will sometimes succeed when it wouldn't easily with target type binding. For example,
756 // forall( otype T ) lvalue T ?[?]( T *, ptrdiff_t );
757 // const char * x = "hello world";
758 // unsigned char ch = x[0];
759 // Fails with simple return type binding. First, T is bound to unsigned char, then (x: const char *) is unified
760 // with unsigned char *, which fails because pointer base types must be unified exactly. The new resolver should
761 // fix this issue in a more robust way.
762 targetType = nullptr;
763 visit( untypedExpr );
764 }
765 }
766
767 bool isLvalue( Expression *expr ) {
768 // xxx - recurse into tuples?
769 return expr->has_result() && expr->get_result()->get_isLvalue();
770 }
771
772 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
773 AlternativeFinder finder( indexer, env );
774 finder.find( addressExpr->get_arg() );
775 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
776 if ( isLvalue( i->expr ) ) {
777 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
778 } // if
779 } // for
780 }
781
782 void AlternativeFinder::visit( CastExpr *castExpr ) {
783 Type *& toType = castExpr->get_result();
784 assert( toType );
785 toType = resolveTypeof( toType, indexer );
786 SymTab::validateType( toType, &indexer );
787 adjustExprType( toType, env, indexer );
788
789 AlternativeFinder finder( indexer, env );
790 finder.targetType = toType;
791 finder.findWithAdjustment( castExpr->get_arg() );
792
793 AltList candidates;
794 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
795 AssertionSet needAssertions, haveAssertions;
796 OpenVarSet openVars;
797
798 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
799 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
800 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
801 // to.
802 int discardedValues = (*i).expr->get_result()->size() - castExpr->get_result()->size();
803 if ( discardedValues < 0 ) continue;
804 // xxx - may need to go into tuple types and extract relevant types and use unifyList. Note that currently, this does not
805 // allow casting a tuple to an atomic type (e.g. (int)([1, 2, 3]))
806 // unification run for side-effects
807 unify( castExpr->get_result(), (*i).expr->get_result(), i->env, needAssertions, haveAssertions, openVars, indexer );
808 Cost thisCost = castCost( (*i).expr->get_result(), castExpr->get_result(), indexer, i->env );
809 if ( thisCost != Cost::infinity ) {
810 // count one safe conversion for each value that is thrown away
811 thisCost += Cost( 0, 0, discardedValues );
812
813 Expression * argExpr = i->expr->clone();
814 if ( argExpr->get_result()->size() > 1 && ! castExpr->get_result()->isVoid() ) {
815 // Argument expression is a tuple and the target type is not void. Cast each member of the tuple
816 // to its corresponding target type, producing the tuple of those cast expressions. If there are
817 // more components of the tuple than components in the target type, then excess components do not
818 // come out in the result expression (but UniqueExprs ensure that side effects will still be done).
819 if ( Tuples::maybeImpure( argExpr ) && ! dynamic_cast< UniqueExpr * >( argExpr ) ) {
820 // expressions which may contain side effects require a single unique instance of the expression.
821 argExpr = new UniqueExpr( argExpr );
822 }
823 std::list< Expression * > componentExprs;
824 for ( unsigned int i = 0; i < castExpr->get_result()->size(); i++ ) {
825 // cast each component
826 TupleIndexExpr * idx = new TupleIndexExpr( argExpr->clone(), i );
827 componentExprs.push_back( new CastExpr( idx, castExpr->get_result()->getComponent( i )->clone() ) );
828 }
829 delete argExpr;
830 assert( componentExprs.size() > 0 );
831 // produce the tuple of casts
832 candidates.push_back( Alternative( new TupleExpr( componentExprs ), i->env, i->cost, thisCost ) );
833 } else {
834 // handle normally
835 candidates.push_back( Alternative( new CastExpr( argExpr->clone(), toType->clone() ), i->env, i->cost, thisCost ) );
836 }
837 } // if
838 } // for
839
840 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
841 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
842 // selects first based on argument cost, then on conversion cost.
843 AltList minArgCost;
844 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
845 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
846 }
847
848 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
849 AlternativeFinder funcFinder( indexer, env );
850 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
851 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
852 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_result() ) ) {
853 addAggMembers( structInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
854 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_result() ) ) {
855 addAggMembers( unionInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
856 } else if ( TupleType * tupleType = dynamic_cast< TupleType * >( agg->expr->get_result() ) ) {
857 addTupleMembers( tupleType, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
858 } // if
859 } // for
860 }
861
862 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
863 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
864 }
865
866 void AlternativeFinder::visit( NameExpr *nameExpr ) {
867 std::list< DeclarationWithType* > declList;
868 indexer.lookupId( nameExpr->get_name(), declList );
869 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
870 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
871 VariableExpr newExpr( *i, nameExpr->get_argName() );
872 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
873 PRINT(
874 std::cerr << "decl is ";
875 (*i)->print( std::cerr );
876 std::cerr << std::endl;
877 std::cerr << "newExpr is ";
878 newExpr.print( std::cerr );
879 std::cerr << std::endl;
880 )
881 renameTypes( alternatives.back().expr );
882 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
883 NameExpr nameExpr( "" );
884 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
885 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
886 NameExpr nameExpr( "" );
887 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
888 } // if
889 } // for
890 }
891
892 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
893 // not sufficient to clone here, because variable's type may have changed
894 // since the VariableExpr was originally created.
895 alternatives.push_back( Alternative( new VariableExpr( variableExpr->get_var() ), env, Cost::zero ) );
896 }
897
898 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
899 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
900 }
901
902 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
903 if ( sizeofExpr->get_isType() ) {
904 // xxx - resolveTypeof?
905 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
906 } else {
907 // find all alternatives for the argument to sizeof
908 AlternativeFinder finder( indexer, env );
909 finder.find( sizeofExpr->get_expr() );
910 // find the lowest cost alternative among the alternatives, otherwise ambiguous
911 AltList winners;
912 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
913 if ( winners.size() != 1 ) {
914 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
915 } // if
916 // return the lowest cost alternative for the argument
917 Alternative &choice = winners.front();
918 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
919 } // if
920 }
921
922 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
923 if ( alignofExpr->get_isType() ) {
924 // xxx - resolveTypeof?
925 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
926 } else {
927 // find all alternatives for the argument to sizeof
928 AlternativeFinder finder( indexer, env );
929 finder.find( alignofExpr->get_expr() );
930 // find the lowest cost alternative among the alternatives, otherwise ambiguous
931 AltList winners;
932 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
933 if ( winners.size() != 1 ) {
934 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
935 } // if
936 // return the lowest cost alternative for the argument
937 Alternative &choice = winners.front();
938 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
939 } // if
940 }
941
942 template< typename StructOrUnionType >
943 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
944 std::list< Declaration* > members;
945 aggInst->lookup( name, members );
946 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
947 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
948 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt ), env, Cost::zero ) );
949 renameTypes( alternatives.back().expr );
950 } else {
951 assert( false );
952 }
953 }
954 }
955
956 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
957 AlternativeFinder funcFinder( indexer, env );
958 // xxx - resolveTypeof?
959 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
960 addOffsetof( structInst, offsetofExpr->get_member() );
961 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
962 addOffsetof( unionInst, offsetofExpr->get_member() );
963 }
964 }
965
966 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
967 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
968 }
969
970 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
971 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
972 }
973
974 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
975 // assume no polymorphism
976 // assume no implicit conversions
977 assert( function->get_parameters().size() == 1 );
978 PRINT(
979 std::cerr << "resolvAttr: funcDecl is ";
980 funcDecl->print( std::cerr );
981 std::cerr << " argType is ";
982 argType->print( std::cerr );
983 std::cerr << std::endl;
984 )
985 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
986 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
987 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
988 alternatives.back().expr->set_result( (*i)->get_type()->clone() );
989 } // for
990 } // if
991 }
992
993 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
994 // assume no 'pointer-to-attribute'
995 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
996 assert( nameExpr );
997 std::list< DeclarationWithType* > attrList;
998 indexer.lookupId( nameExpr->get_name(), attrList );
999 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
1000 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
1001 // check if the type is function
1002 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
1003 // assume exactly one parameter
1004 if ( function->get_parameters().size() == 1 ) {
1005 if ( attrExpr->get_isType() ) {
1006 resolveAttr( *i, function, attrExpr->get_type(), env );
1007 } else {
1008 AlternativeFinder finder( indexer, env );
1009 finder.find( attrExpr->get_expr() );
1010 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
1011 if ( choice->expr->get_result()->size() == 1 ) {
1012 resolveAttr(*i, function, choice->expr->get_result(), choice->env );
1013 } // fi
1014 } // for
1015 } // if
1016 } // if
1017 } // if
1018 } // for
1019 } else {
1020 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
1021 VariableExpr newExpr( *i );
1022 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
1023 renameTypes( alternatives.back().expr );
1024 } // for
1025 } // if
1026 }
1027
1028 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
1029 AlternativeFinder firstFinder( indexer, env );
1030 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
1031 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
1032 AlternativeFinder secondFinder( indexer, first->env );
1033 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
1034 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
1035 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
1036 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
1037 }
1038 }
1039 }
1040
1041 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
1042 AlternativeFinder firstFinder( indexer, env );
1043 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
1044 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
1045 AlternativeFinder secondFinder( indexer, first->env );
1046 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
1047 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
1048 AlternativeFinder thirdFinder( indexer, second->env );
1049 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
1050 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
1051 OpenVarSet openVars;
1052 AssertionSet needAssertions, haveAssertions;
1053 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
1054 Type* commonType = nullptr;
1055 if ( unify( second->expr->get_result(), third->expr->get_result(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
1056 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
1057 newExpr->set_result( commonType ? commonType : second->expr->get_result()->clone() );
1058 newAlt.expr = newExpr;
1059 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
1060 } // if
1061 } // for
1062 } // for
1063 } // for
1064 }
1065
1066 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
1067 TypeEnvironment newEnv( env );
1068 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
1069 AlternativeFinder secondFinder( indexer, newEnv );
1070 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
1071 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
1072 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
1073 } // for
1074 delete newFirstArg;
1075 }
1076
1077 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
1078 std::list< AlternativeFinder > subExprAlternatives;
1079 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
1080 std::list< AltList > possibilities;
1081 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
1082 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
1083 TupleExpr *newExpr = new TupleExpr;
1084 makeExprList( *i, newExpr->get_exprs() );
1085 newExpr->set_result( Tuples::makeTupleType( newExpr->get_exprs() ) );
1086
1087 TypeEnvironment compositeEnv;
1088 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1089 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1090 } // for
1091 }
1092
1093 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1094 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1095 }
1096
1097 void AlternativeFinder::visit( ConstructorExpr * ctorExpr ) {
1098 AlternativeFinder finder( indexer, env );
1099 // don't prune here, since it's guaranteed all alternatives will have the same type
1100 // (giving the alternatives different types is half of the point of ConstructorExpr nodes)
1101 finder.findWithAdjustment( ctorExpr->get_callExpr(), false );
1102 for ( Alternative & alt : finder.alternatives ) {
1103 alternatives.push_back( Alternative( new ConstructorExpr( alt.expr->clone() ), alt.env, alt.cost ) );
1104 }
1105 }
1106
1107 void AlternativeFinder::visit( TupleIndexExpr *tupleExpr ) {
1108 alternatives.push_back( Alternative( tupleExpr->clone(), env, Cost::zero ) );
1109 }
1110
1111 void AlternativeFinder::visit( TupleAssignExpr *tupleAssignExpr ) {
1112 alternatives.push_back( Alternative( tupleAssignExpr->clone(), env, Cost::zero ) );
1113 }
1114
1115 void AlternativeFinder::visit( UniqueExpr *unqExpr ) {
1116 AlternativeFinder finder( indexer, env );
1117 finder.findWithAdjustment( unqExpr->get_expr() );
1118 for ( Alternative & alt : finder.alternatives ) {
1119 // ensure that the id is passed on to the UniqueExpr alternative so that the expressions are "linked"
1120 UniqueExpr * newUnqExpr = new UniqueExpr( alt.expr->clone(), unqExpr->get_id() );
1121 alternatives.push_back( Alternative( newUnqExpr, alt.env, alt.cost ) );
1122 }
1123 }
1124
1125 void AlternativeFinder::visit( StmtExpr *stmtExpr ) {
1126 StmtExpr * newStmtExpr = stmtExpr->clone();
1127 ResolvExpr::resolveStmtExpr( newStmtExpr, indexer );
1128 // xxx - this env is almost certainly wrong, and needs to somehow contain the combined environments from all of the statements in the stmtExpr...
1129 alternatives.push_back( Alternative( newStmtExpr, env, Cost::zero ) );
1130 }
1131
1132} // namespace ResolvExpr
1133
1134// Local Variables: //
1135// tab-width: 4 //
1136// mode: c++ //
1137// compile-command: "make install" //
1138// End: //
Note: See TracBrowser for help on using the repository browser.