source: src/ResolvExpr/AlternativeFinder.cc@ ea83e00a

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 stuck-waitfor-destruct with_gc
Last change on this file since ea83e00a was ea83e00a, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

attempt to narrow resolution of function calls based on return type if a cast is applied
  • Property mode set to 100644
File size: 48.2 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
47extern bool resolvep;
48#define PRINT( text ) if ( resolvep ) { text }
49//#define DEBUG_COST
50
51namespace ResolvExpr {
52 Expression *resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
53 CastExpr *castToVoid = new CastExpr( expr );
54
55 AlternativeFinder finder( indexer, env );
56 finder.findWithAdjustment( castToVoid );
57
58 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
59 // interpretations, an exception has already been thrown.
60 assert( finder.get_alternatives().size() == 1 );
61 CastExpr *newExpr = dynamic_cast< CastExpr* >( finder.get_alternatives().front().expr );
62 assert( newExpr );
63 env = finder.get_alternatives().front().env;
64 return newExpr->get_arg()->clone();
65 }
66
67 Cost sumCost( const AltList &in ) {
68 Cost total;
69 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
70 total += i->cost;
71 }
72 return total;
73 }
74
75 namespace {
76 void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
77 for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
78 i->print( os, indent );
79 os << std::endl;
80 }
81 }
82
83 void makeExprList( const AltList &in, std::list< Expression* > &out ) {
84 for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
85 out.push_back( i->expr->clone() );
86 }
87 }
88
89 struct PruneStruct {
90 bool isAmbiguous;
91 AltList::iterator candidate;
92 PruneStruct() {}
93 PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
94 };
95
96 /// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
97 template< typename InputIterator, typename OutputIterator >
98 void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
99 // select the alternatives that have the minimum conversion cost for a particular set of result types
100 std::map< std::string, PruneStruct > selected;
101 for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
102 PruneStruct current( candidate );
103 std::string mangleName;
104 {
105 Type * newType = candidate->expr->get_result()->clone();
106 candidate->env.apply( newType );
107 mangleName = SymTab::Mangler::mangle( newType );
108 delete newType;
109 }
110 std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
111 if ( mapPlace != selected.end() ) {
112 if ( candidate->cost < mapPlace->second.candidate->cost ) {
113 PRINT(
114 std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
115 )
116 selected[ mangleName ] = current;
117 } else if ( candidate->cost == mapPlace->second.candidate->cost ) {
118 PRINT(
119 std::cerr << "marking ambiguous" << std::endl;
120 )
121 mapPlace->second.isAmbiguous = true;
122 }
123 } else {
124 selected[ mangleName ] = current;
125 }
126 }
127
128 PRINT(
129 std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
130 )
131
132 // accept the alternatives that were unambiguous
133 for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
134 if ( ! target->second.isAmbiguous ) {
135 Alternative &alt = *target->second.candidate;
136 alt.env.applyFree( alt.expr->get_result() );
137 *out++ = alt;
138 }
139 }
140 }
141
142 void renameTypes( Expression *expr ) {
143 expr->get_result()->accept( global_renamer );
144 }
145 }
146
147 template< typename InputIterator, typename OutputIterator >
148 void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
149 while ( begin != end ) {
150 AlternativeFinder finder( indexer, env );
151 finder.findWithAdjustment( *begin );
152 // XXX either this
153 //Designators::fixDesignations( finder, (*begin++)->get_argName() );
154 // or XXX this
155 begin++;
156 PRINT(
157 std::cerr << "findSubExprs" << std::endl;
158 printAlts( finder.alternatives, std::cerr );
159 )
160 *out++ = finder;
161 }
162 }
163
164 AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
165 : indexer( indexer ), env( env ) {
166 }
167
168 void AlternativeFinder::find( Expression *expr, bool adjust, bool prune ) {
169 expr->accept( *this );
170 if ( alternatives.empty() ) {
171 throw SemanticError( "No reasonable alternatives for expression ", expr );
172 }
173 for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
174 if ( adjust ) {
175 adjustExprType( i->expr->get_result(), i->env, indexer );
176 }
177 }
178 if ( prune ) {
179 PRINT(
180 std::cerr << "alternatives before prune:" << std::endl;
181 printAlts( alternatives, std::cerr );
182 )
183 AltList::iterator oldBegin = alternatives.begin();
184 pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
185 if ( alternatives.begin() == oldBegin ) {
186 std::ostringstream stream;
187 stream << "Can't choose between " << alternatives.size() << " alternatives for expression ";
188 expr->print( stream );
189 stream << "Alternatives are:";
190 AltList winners;
191 findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
192 printAlts( winners, stream, 8 );
193 throw SemanticError( stream.str() );
194 }
195 alternatives.erase( oldBegin, alternatives.end() );
196 PRINT(
197 std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
198 )
199 }
200
201 // Central location to handle gcc extension keyword for all expression types.
202 for ( Alternative &iter: alternatives ) {
203 iter.expr->set_extension( expr->get_extension() );
204 } // for
205 }
206
207 void AlternativeFinder::findWithAdjustment( Expression *expr, bool prune ) {
208 find( expr, true, prune );
209 }
210
211 // std::unordered_map< Expression *, UniqueExpr * > ;
212
213 template< typename StructOrUnionType >
214 void AlternativeFinder::addAggMembers( StructOrUnionType *aggInst, Expression *expr, const Cost &newCost, const TypeEnvironment & env, Expression * member ) {
215 // by this point, member must be a name expr
216 NameExpr * nameExpr = safe_dynamic_cast< NameExpr * >( member );
217 const std::string & name = nameExpr->get_name();
218 std::list< Declaration* > members;
219 aggInst->lookup( name, members );
220 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
221 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
222 alternatives.push_back( Alternative( new MemberExpr( dwt, expr->clone() ), env, newCost ) );
223 renameTypes( alternatives.back().expr );
224 } else {
225 assert( false );
226 }
227 }
228 }
229
230 void AlternativeFinder::addTupleMembers( TupleType * tupleType, Expression *expr, const Cost &newCost, const TypeEnvironment & env, Expression * member ) {
231 if ( ConstantExpr * constantExpr = dynamic_cast< ConstantExpr * >( member ) ) {
232 // get the value of the constant expression as an int, must be between 0 and the length of the tuple type to have meaning
233 // xxx - this should be improved by memoizing the value of constant exprs
234 // during parsing and reusing that information here.
235 std::stringstream ss( constantExpr->get_constant()->get_value() );
236 int val;
237 std::string tmp;
238 if ( ss >> val && ! (ss >> tmp) ) {
239 if ( val >= 0 && (unsigned int)val < tupleType->size() ) {
240 alternatives.push_back( Alternative( new TupleIndexExpr( expr->clone(), val ), env, newCost ) );
241 } // if
242 } // if
243 } else if ( NameExpr * nameExpr = dynamic_cast< NameExpr * >( member ) ) {
244 // xxx - temporary hack until 0/1 are int constants
245 if ( nameExpr->get_name() == "0" || nameExpr->get_name() == "1" ) {
246 std::stringstream ss( nameExpr->get_name() );
247 int val;
248 ss >> val;
249 alternatives.push_back( Alternative( new TupleIndexExpr( expr->clone(), val ), env, newCost ) );
250 }
251 } // if
252 }
253
254 void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
255 alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
256 }
257
258 Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
259 ApplicationExpr *appExpr = safe_dynamic_cast< ApplicationExpr* >( alt.expr );
260 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
261 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
262
263 Cost convCost( 0, 0, 0 );
264 std::list< DeclarationWithType* >& formals = function->get_parameters();
265 std::list< DeclarationWithType* >::iterator formal = formals.begin();
266 std::list< Expression* >& actuals = appExpr->get_args();
267
268 std::list< Type * > formalTypes;
269 std::list< Type * >::iterator formalType = formalTypes.end();
270
271 for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
272
273 PRINT(
274 std::cerr << "actual expression:" << std::endl;
275 (*actualExpr)->print( std::cerr, 8 );
276 std::cerr << "--- results are" << std::endl;
277 (*actualExpr)->get_result()->print( std::cerr, 8 );
278 )
279 std::list< DeclarationWithType* >::iterator startFormal = formal;
280 Cost actualCost;
281 std::list< Type * > flatActualTypes;
282 flatten( (*actualExpr)->get_result(), back_inserter( flatActualTypes ) );
283 for ( std::list< Type* >::iterator actualType = flatActualTypes.begin(); actualType != flatActualTypes.end(); ++actualType ) {
284
285
286 // tuple handling code
287 if ( formalType == formalTypes.end() ) {
288 // the type of the formal parameter may be a tuple type. To make this easier to work with,
289 // flatten the tuple type and traverse the resulting list of types, incrementing the formal
290 // iterator once its types have been extracted. Once a particular formal parameter's type has
291 // been exhausted load the next formal parameter's type.
292 if ( formal == formals.end() ) {
293 if ( function->get_isVarArgs() ) {
294 convCost += Cost( 1, 0, 0 );
295 break;
296 } else {
297 return Cost::infinity;
298 }
299 }
300 formalTypes.clear();
301 flatten( (*formal)->get_type(), back_inserter( formalTypes ) );
302 formalType = formalTypes.begin();
303 ++formal;
304 }
305
306 PRINT(
307 std::cerr << std::endl << "converting ";
308 (*actualType)->print( std::cerr, 8 );
309 std::cerr << std::endl << " to ";
310 (*formalType)->print( std::cerr, 8 );
311 )
312 Cost newCost = conversionCost( *actualType, *formalType, indexer, alt.env );
313 PRINT(
314 std::cerr << std::endl << "cost is" << newCost << std::endl;
315 )
316
317 if ( newCost == Cost::infinity ) {
318 return newCost;
319 }
320 convCost += newCost;
321 actualCost += newCost;
322
323 convCost += Cost( 0, polyCost( *formalType, alt.env, indexer ) + polyCost( *actualType, alt.env, indexer ), 0 );
324
325 formalType++;
326 }
327 if ( actualCost != Cost( 0, 0, 0 ) ) {
328 std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
329 startFormalPlusOne++;
330 if ( formal == startFormalPlusOne ) {
331 // not a tuple type
332 Type *newType = (*startFormal)->get_type()->clone();
333 alt.env.apply( newType );
334 *actualExpr = new CastExpr( *actualExpr, newType );
335 } else {
336 TupleType *newType = new TupleType( Type::Qualifiers() );
337 for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
338 newType->get_types().push_back( (*i)->get_type()->clone() );
339 }
340 alt.env.apply( newType );
341 *actualExpr = new CastExpr( *actualExpr, newType );
342 }
343 }
344
345 }
346 if ( formal != formals.end() ) {
347 return Cost::infinity;
348 }
349
350 for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
351 PRINT(
352 std::cerr << std::endl << "converting ";
353 assert->second.actualType->print( std::cerr, 8 );
354 std::cerr << std::endl << " to ";
355 assert->second.formalType->print( std::cerr, 8 );
356 )
357 Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
358 PRINT(
359 std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
360 )
361 if ( newCost == Cost::infinity ) {
362 return newCost;
363 }
364 convCost += newCost;
365
366 convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
367 }
368
369 return convCost;
370 }
371
372 /// Adds type variables to the open variable set and marks their assertions
373 void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
374 for ( Type::ForallList::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
375 unifiableVars[ (*tyvar)->get_name() ] = TypeDecl::Data{ *tyvar };
376 for ( std::list< DeclarationWithType* >::iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
377 needAssertions[ *assert ] = true;
378 }
379/// needAssertions.insert( needAssertions.end(), (*tyvar)->get_assertions().begin(), (*tyvar)->get_assertions().end() );
380 }
381 }
382
383 /// instantiate a single argument by matching actuals from [actualIt, actualEnd) against formalType,
384 /// producing expression(s) in out and their total cost in cost.
385 template< typename AltIterator, typename OutputIterator >
386 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 ) {
387 if ( TupleType * tupleType = dynamic_cast< TupleType * >( formalType ) ) {
388 // formalType is a TupleType - group actuals into a TupleExpr whose type unifies with the TupleType
389 TupleExpr * tupleExpr = new TupleExpr();
390 for ( Type * type : *tupleType ) {
391 if ( ! instantiateArgument( type, defaultValue, actualIt, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( tupleExpr->get_exprs() ) ) ) {
392 delete tupleExpr;
393 return false;
394 }
395 }
396 tupleExpr->set_result( Tuples::makeTupleType( tupleExpr->get_exprs() ) );
397 *out++ = tupleExpr;
398 } else if ( actualIt != actualEnd ) {
399 // both actualType and formalType are atomic (non-tuple) types - if they unify
400 // then accept actual as an argument, otherwise return false (fail to instantiate argument)
401 Expression * actual = actualIt->expr;
402 Type * actualType = actual->get_result();
403 PRINT(
404 std::cerr << "formal type is ";
405 formalType->print( std::cerr );
406 std::cerr << std::endl << "actual type is ";
407 actualType->print( std::cerr );
408 std::cerr << std::endl;
409 )
410 if ( ! unify( formalType, actualType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
411 return false;
412 }
413 // move the expression from the alternative to the output iterator
414 *out++ = actual;
415 actualIt->expr = nullptr;
416 cost += actualIt->cost;
417 ++actualIt;
418 } else {
419 // End of actuals - Handle default values
420 if ( SingleInit *si = dynamic_cast<SingleInit *>( defaultValue )) {
421 // so far, only constant expressions are accepted as default values
422 if ( ConstantExpr *cnstexpr = dynamic_cast<ConstantExpr *>( si->get_value()) ) {
423 if ( Constant *cnst = dynamic_cast<Constant *>( cnstexpr->get_constant() ) ) {
424 if ( unify( formalType, cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
425 // xxx - Don't know if this is right
426 *out++ = cnstexpr->clone();
427 return true;
428 } // if
429 } // if
430 } // if
431 } // if
432 return false;
433 } // if
434 return true;
435 }
436
437 bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, const AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave, AltList & out ) {
438 simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
439 // make sure we don't widen any existing bindings
440 for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
441 i->allowWidening = false;
442 }
443 resultEnv.extractOpenVars( openVars );
444
445 // flatten actuals so that each actual has an atomic (non-tuple) type
446 AltList exploded;
447 Tuples::explode( actuals, indexer, back_inserter( exploded ) );
448
449 AltList::iterator actualExpr = exploded.begin();
450 AltList::iterator actualEnd = exploded.end();
451 for ( DeclarationWithType * formal : formals ) {
452 // match flattened actuals with formal parameters - actuals will be grouped to match
453 // with formals as appropriate
454 Cost cost;
455 std::list< Expression * > newExprs;
456 ObjectDecl * obj = safe_dynamic_cast< ObjectDecl * >( formal );
457 if ( ! instantiateArgument( obj->get_type(), obj->get_init(), actualExpr, actualEnd, openVars, resultEnv, resultNeed, resultHave, indexer, cost, back_inserter( newExprs ) ) ) {
458 deleteAll( newExprs );
459 return false;
460 }
461 // success - produce argument as a new alternative
462 assert( newExprs.size() == 1 );
463 out.push_back( Alternative( newExprs.front(), resultEnv, cost ) );
464 }
465 if ( actualExpr != actualEnd ) {
466 // there are still actuals remaining, but we've run out of formal parameters to match against
467 // this is okay only if the function is variadic
468 if ( ! isVarArgs ) {
469 return false;
470 }
471 out.splice( out.end(), exploded, actualExpr, actualEnd );
472 }
473 return true;
474 }
475
476 // /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
477 //typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
478
479 static const int recursionLimit = /*10*/ 4; ///< Limit to depth of recursion satisfaction
480 //static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
481
482 void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
483 for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
484 if ( i->second == true ) {
485 i->first->accept( indexer );
486 }
487 }
488 }
489
490 template< typename ForwardIterator, typename OutputIterator >
491 void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /*const AssertionParentSet &needParents,*/
492 int level, const SymTab::Indexer &indexer, OutputIterator out ) {
493 if ( begin == end ) {
494 if ( newNeed.empty() ) {
495 *out++ = newAlt;
496 return;
497 } else if ( level >= recursionLimit ) {
498 throw SemanticError( "Too many recursive assertions" );
499 } else {
500 AssertionSet newerNeed;
501 PRINT(
502 std::cerr << "recursing with new set:" << std::endl;
503 printAssertionSet( newNeed, std::cerr, 8 );
504 )
505 inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /*needParents,*/ level+1, indexer, out );
506 return;
507 }
508 }
509
510 ForwardIterator cur = begin++;
511 if ( ! cur->second ) {
512 inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /*needParents,*/ level, indexer, out );
513 return; // xxx - should this continue? previously this wasn't here, and it looks like it should be
514 }
515 DeclarationWithType *curDecl = cur->first;
516
517 PRINT(
518 std::cerr << "inferRecursive: assertion is ";
519 curDecl->print( std::cerr );
520 std::cerr << std::endl;
521 )
522 std::list< DeclarationWithType* > candidates;
523 decls.lookupId( curDecl->get_name(), candidates );
524/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
525 for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
526 PRINT(
527 std::cerr << "inferRecursive: candidate is ";
528 (*candidate)->print( std::cerr );
529 std::cerr << std::endl;
530 )
531
532 AssertionSet newHave, newerNeed( newNeed );
533 TypeEnvironment newEnv( newAlt.env );
534 OpenVarSet newOpenVars( openVars );
535 Type *adjType = (*candidate)->get_type()->clone();
536 adjustExprType( adjType, newEnv, indexer );
537 adjType->accept( global_renamer );
538 PRINT(
539 std::cerr << "unifying ";
540 curDecl->get_type()->print( std::cerr );
541 std::cerr << " with ";
542 adjType->print( std::cerr );
543 std::cerr << std::endl;
544 )
545 if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
546 PRINT(
547 std::cerr << "success!" << std::endl;
548 )
549 SymTab::Indexer newDecls( decls );
550 addToIndexer( newHave, newDecls );
551 Alternative newerAlt( newAlt );
552 newerAlt.env = newEnv;
553 assert( (*candidate)->get_uniqueId() );
554 DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
555 //AssertionParentSet newNeedParents( needParents );
556 // skip repeatingly-self-recursive assertion satisfaction
557 // DOESN'T WORK: grandchild nodes conflict with their cousins
558 //if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
559 Expression *varExpr = new VariableExpr( candDecl );
560 delete varExpr->get_result();
561 varExpr->set_result( adjType->clone() );
562 PRINT(
563 std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
564 curDecl->print( std::cerr );
565 std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
566 (*candidate)->print( std::cerr );
567 std::cerr << std::endl;
568 )
569 ApplicationExpr *appExpr = static_cast< ApplicationExpr* >( newerAlt.expr );
570 // XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
571 appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
572 inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /*newNeedParents,*/ level, indexer, out );
573 } else {
574 delete adjType;
575 }
576 }
577 }
578
579 template< typename OutputIterator >
580 void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
581// PRINT(
582// std::cerr << "inferParameters: assertions needed are" << std::endl;
583// printAll( need, std::cerr, 8 );
584// )
585 SymTab::Indexer decls( indexer );
586 PRINT(
587 std::cerr << "============= original indexer" << std::endl;
588 indexer.print( std::cerr );
589 std::cerr << "============= new indexer" << std::endl;
590 decls.print( std::cerr );
591 )
592 addToIndexer( have, decls );
593 AssertionSet newNeed;
594 //AssertionParentSet needParents;
595 inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /*needParents,*/ 0, indexer, out );
596// PRINT(
597// std::cerr << "declaration 14 is ";
598// Declaration::declFromId
599// *out++ = newAlt;
600// )
601 }
602
603 template< typename OutputIterator >
604 void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, const AltList &actualAlt, OutputIterator out ) {
605 OpenVarSet openVars;
606 AssertionSet resultNeed, resultHave;
607 TypeEnvironment resultEnv;
608 makeUnifiableVars( funcType, openVars, resultNeed );
609 AltList instantiatedActuals; // filled by instantiate function
610 if ( targetType && ! targetType->isVoid() ) {
611 // attempt to narrow based on expected target type
612 Type * returnType = funcType->get_returnVals().front()->get_type();
613 if ( ! unify( returnType, targetType, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
614 // unification failed, don't pursue this alternative
615 return;
616 }
617 }
618
619 if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave, instantiatedActuals ) ) {
620 ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
621 Alternative newAlt( appExpr, resultEnv, sumCost( instantiatedActuals ) );
622 makeExprList( instantiatedActuals, appExpr->get_args() );
623 PRINT(
624 std::cerr << "need assertions:" << std::endl;
625 printAssertionSet( resultNeed, std::cerr, 8 );
626 )
627 inferParameters( resultNeed, resultHave, newAlt, openVars, out );
628 }
629 }
630
631 void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
632 bool doneInit = false;
633 AlternativeFinder funcOpFinder( indexer, env );
634
635 AlternativeFinder funcFinder( indexer, env );
636
637 {
638 std::string fname = InitTweak::getFunctionName( untypedExpr );
639 if ( fname == "&&" ) {
640 VoidType v = Type::Qualifiers(); // resolve to type void *
641 PointerType pt( Type::Qualifiers(), v.clone() );
642 UntypedExpr *vexpr = untypedExpr->clone();
643 vexpr->set_result( pt.clone() );
644 alternatives.push_back( Alternative( vexpr, env, Cost()) );
645 return;
646 }
647 }
648
649 funcFinder.findWithAdjustment( untypedExpr->get_function() );
650 std::list< AlternativeFinder > argAlternatives;
651 findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
652
653 std::list< AltList > possibilities;
654 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
655
656 // take care of possible tuple assignments
657 // if not tuple assignment, assignment is taken care of as a normal function call
658 Tuples::handleTupleAssignment( *this, untypedExpr, possibilities );
659
660 AltList candidates;
661 SemanticError errors;
662 for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
663 try {
664 PRINT(
665 std::cerr << "working on alternative: " << std::endl;
666 func->print( std::cerr, 8 );
667 )
668 // check if the type is pointer to function
669 PointerType *pointer;
670 if ( ( pointer = dynamic_cast< PointerType* >( func->expr->get_result() ) ) ) {
671 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
672 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
673 // XXX
674 //Designators::check_alternative( function, *actualAlt );
675 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
676 }
677 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( pointer->get_base() ) ) {
678 EqvClass eqvClass;
679 if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
680 if ( FunctionType *function = dynamic_cast< FunctionType* >( eqvClass.type ) ) {
681 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
682 makeFunctionAlternatives( *func, function, *actualAlt, std::back_inserter( candidates ) );
683 } // for
684 } // if
685 } // if
686 } // if
687 } else {
688 // seek a function operator that's compatible
689 if ( ! doneInit ) {
690 doneInit = true;
691 NameExpr *opExpr = new NameExpr( "?()" );
692 try {
693 funcOpFinder.findWithAdjustment( opExpr );
694 } catch( SemanticError &e ) {
695 // it's ok if there aren't any defined function ops
696 }
697 PRINT(
698 std::cerr << "known function ops:" << std::endl;
699 printAlts( funcOpFinder.alternatives, std::cerr, 8 );
700 )
701 }
702
703 for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
704 // check if the type is pointer to function
705 PointerType *pointer;
706 if ( ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_result() ) ) ) {
707 if ( FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() ) ) {
708 for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
709 AltList currentAlt;
710 currentAlt.push_back( *func );
711 currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
712 makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
713 } // for
714 } // if
715 } // if
716 } // for
717 } // if
718 } catch ( SemanticError &e ) {
719 errors.append( e );
720 }
721 } // for
722
723 // Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
724 if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
725
726 for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
727 Cost cvtCost = computeConversionCost( *withFunc, indexer );
728
729 PRINT(
730 ApplicationExpr *appExpr = safe_dynamic_cast< ApplicationExpr* >( withFunc->expr );
731 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
732 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
733 std::cerr << "Case +++++++++++++" << std::endl;
734 std::cerr << "formals are:" << std::endl;
735 printAll( function->get_parameters(), std::cerr, 8 );
736 std::cerr << "actuals are:" << std::endl;
737 printAll( appExpr->get_args(), std::cerr, 8 );
738 std::cerr << "bindings are:" << std::endl;
739 withFunc->env.print( std::cerr, 8 );
740 std::cerr << "cost of conversion is:" << cvtCost << std::endl;
741 )
742 if ( cvtCost != Cost::infinity ) {
743 withFunc->cvtCost = cvtCost;
744 alternatives.push_back( *withFunc );
745 } // if
746 } // for
747 candidates.clear();
748 candidates.splice( candidates.end(), alternatives );
749
750 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
751
752 if ( alternatives.empty() && targetType && ! targetType->isVoid() ) {
753 // xxx - this is a temporary hack. If resolution is unsuccessful with a target type, try again without a
754 // target type, since it will sometimes succeed when it wouldn't easily with target type binding. For example,
755 // forall( otype T ) lvalue T ?[?]( T *, ptrdiff_t );
756 // const char * x = "hello world";
757 // unsigned char ch = x[0];
758 // Fails with simple return type binding. First, T is bound to unsigned char, then (x: const char *) is unified
759 // with unsigned char *, which fails because pointer base types must be unified exactly. The new resolver should
760 // fix this issue in a more robust way.
761 targetType = nullptr;
762 visit( untypedExpr );
763 }
764 }
765
766 bool isLvalue( Expression *expr ) {
767 // xxx - recurse into tuples?
768 return expr->has_result() && expr->get_result()->get_isLvalue();
769 }
770
771 void AlternativeFinder::visit( AddressExpr *addressExpr ) {
772 AlternativeFinder finder( indexer, env );
773 finder.find( addressExpr->get_arg() );
774 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
775 if ( isLvalue( i->expr ) ) {
776 alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
777 } // if
778 } // for
779 }
780
781 void AlternativeFinder::visit( CastExpr *castExpr ) {
782 Type *& toType = castExpr->get_result();
783 assert( toType );
784 toType = resolveTypeof( toType, indexer );
785 SymTab::validateType( toType, &indexer );
786 adjustExprType( toType, env, indexer );
787
788 AlternativeFinder finder( indexer, env );
789 finder.targetType = toType;
790 finder.findWithAdjustment( castExpr->get_arg() );
791
792 AltList candidates;
793 for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
794 AssertionSet needAssertions, haveAssertions;
795 OpenVarSet openVars;
796
797 // It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
798 // cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
799 // that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
800 // to.
801 int discardedValues = (*i).expr->get_result()->size() - castExpr->get_result()->size();
802 if ( discardedValues < 0 ) continue;
803 // xxx - may need to go into tuple types and extract relevant types and use unifyList. Note that currently, this does not
804 // allow casting a tuple to an atomic type (e.g. (int)([1, 2, 3]))
805 // unification run for side-effects
806 unify( castExpr->get_result(), (*i).expr->get_result(), i->env, needAssertions, haveAssertions, openVars, indexer );
807 Cost thisCost = castCost( (*i).expr->get_result(), castExpr->get_result(), indexer, i->env );
808 if ( thisCost != Cost::infinity ) {
809 // count one safe conversion for each value that is thrown away
810 thisCost += Cost( 0, 0, discardedValues );
811
812 Expression * argExpr = i->expr->clone();
813 if ( argExpr->get_result()->size() > 1 && ! castExpr->get_result()->isVoid() ) {
814 // Argument expression is a tuple and the target type is not void. Cast each member of the tuple
815 // to its corresponding target type, producing the tuple of those cast expressions. If there are
816 // more components of the tuple than components in the target type, then excess components do not
817 // come out in the result expression (but UniqueExprs ensure that side effects will still be done).
818 if ( Tuples::maybeImpure( argExpr ) && ! dynamic_cast< UniqueExpr * >( argExpr ) ) {
819 // expressions which may contain side effects require a single unique instance of the expression.
820 argExpr = new UniqueExpr( argExpr );
821 }
822 std::list< Expression * > componentExprs;
823 for ( unsigned int i = 0; i < castExpr->get_result()->size(); i++ ) {
824 // cast each component
825 TupleIndexExpr * idx = new TupleIndexExpr( argExpr->clone(), i );
826 componentExprs.push_back( new CastExpr( idx, castExpr->get_result()->getComponent( i )->clone() ) );
827 }
828 delete argExpr;
829 assert( componentExprs.size() > 0 );
830 // produce the tuple of casts
831 candidates.push_back( Alternative( new TupleExpr( componentExprs ), i->env, i->cost, thisCost ) );
832 } else {
833 // handle normally
834 candidates.push_back( Alternative( new CastExpr( argExpr->clone(), toType->clone() ), i->env, i->cost, thisCost ) );
835 }
836 } // if
837 } // for
838
839 // findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
840 // cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
841 // selects first based on argument cost, then on conversion cost.
842 AltList minArgCost;
843 findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
844 findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
845 }
846
847 void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
848 AlternativeFinder funcFinder( indexer, env );
849 funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
850 for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
851 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( agg->expr->get_result() ) ) {
852 addAggMembers( structInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
853 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( agg->expr->get_result() ) ) {
854 addAggMembers( unionInst, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
855 } else if ( TupleType * tupleType = dynamic_cast< TupleType * >( agg->expr->get_result() ) ) {
856 addTupleMembers( tupleType, agg->expr, agg->cost, agg->env, memberExpr->get_member() );
857 } // if
858 } // for
859 }
860
861 void AlternativeFinder::visit( MemberExpr *memberExpr ) {
862 alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
863 }
864
865 void AlternativeFinder::visit( NameExpr *nameExpr ) {
866 std::list< DeclarationWithType* > declList;
867 indexer.lookupId( nameExpr->get_name(), declList );
868 PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
869 for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
870 VariableExpr newExpr( *i, nameExpr->get_argName() );
871 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
872 PRINT(
873 std::cerr << "decl is ";
874 (*i)->print( std::cerr );
875 std::cerr << std::endl;
876 std::cerr << "newExpr is ";
877 newExpr.print( std::cerr );
878 std::cerr << std::endl;
879 )
880 renameTypes( alternatives.back().expr );
881 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( (*i)->get_type() ) ) {
882 NameExpr nameExpr( "" );
883 addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
884 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( (*i)->get_type() ) ) {
885 NameExpr nameExpr( "" );
886 addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), env, &nameExpr );
887 } // if
888 } // for
889 }
890
891 void AlternativeFinder::visit( VariableExpr *variableExpr ) {
892 // not sufficient to clone here, because variable's type may have changed
893 // since the VariableExpr was originally created.
894 alternatives.push_back( Alternative( new VariableExpr( variableExpr->get_var() ), env, Cost::zero ) );
895 }
896
897 void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
898 alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
899 }
900
901 void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
902 if ( sizeofExpr->get_isType() ) {
903 // xxx - resolveTypeof?
904 alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
905 } else {
906 // find all alternatives for the argument to sizeof
907 AlternativeFinder finder( indexer, env );
908 finder.find( sizeofExpr->get_expr() );
909 // find the lowest cost alternative among the alternatives, otherwise ambiguous
910 AltList winners;
911 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
912 if ( winners.size() != 1 ) {
913 throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
914 } // if
915 // return the lowest cost alternative for the argument
916 Alternative &choice = winners.front();
917 alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
918 } // if
919 }
920
921 void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
922 if ( alignofExpr->get_isType() ) {
923 // xxx - resolveTypeof?
924 alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
925 } else {
926 // find all alternatives for the argument to sizeof
927 AlternativeFinder finder( indexer, env );
928 finder.find( alignofExpr->get_expr() );
929 // find the lowest cost alternative among the alternatives, otherwise ambiguous
930 AltList winners;
931 findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
932 if ( winners.size() != 1 ) {
933 throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
934 } // if
935 // return the lowest cost alternative for the argument
936 Alternative &choice = winners.front();
937 alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
938 } // if
939 }
940
941 template< typename StructOrUnionType >
942 void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
943 std::list< Declaration* > members;
944 aggInst->lookup( name, members );
945 for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
946 if ( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i ) ) {
947 alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt ), env, Cost::zero ) );
948 renameTypes( alternatives.back().expr );
949 } else {
950 assert( false );
951 }
952 }
953 }
954
955 void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
956 AlternativeFinder funcFinder( indexer, env );
957 // xxx - resolveTypeof?
958 if ( StructInstType *structInst = dynamic_cast< StructInstType* >( offsetofExpr->get_type() ) ) {
959 addOffsetof( structInst, offsetofExpr->get_member() );
960 } else if ( UnionInstType *unionInst = dynamic_cast< UnionInstType* >( offsetofExpr->get_type() ) ) {
961 addOffsetof( unionInst, offsetofExpr->get_member() );
962 }
963 }
964
965 void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
966 alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
967 }
968
969 void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
970 alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
971 }
972
973 void AlternativeFinder::resolveAttr( DeclarationWithType *funcDecl, FunctionType *function, Type *argType, const TypeEnvironment &env ) {
974 // assume no polymorphism
975 // assume no implicit conversions
976 assert( function->get_parameters().size() == 1 );
977 PRINT(
978 std::cerr << "resolvAttr: funcDecl is ";
979 funcDecl->print( std::cerr );
980 std::cerr << " argType is ";
981 argType->print( std::cerr );
982 std::cerr << std::endl;
983 )
984 if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
985 alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
986 for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
987 alternatives.back().expr->set_result( (*i)->get_type()->clone() );
988 } // for
989 } // if
990 }
991
992 void AlternativeFinder::visit( AttrExpr *attrExpr ) {
993 // assume no 'pointer-to-attribute'
994 NameExpr *nameExpr = dynamic_cast< NameExpr* >( attrExpr->get_attr() );
995 assert( nameExpr );
996 std::list< DeclarationWithType* > attrList;
997 indexer.lookupId( nameExpr->get_name(), attrList );
998 if ( attrExpr->get_isType() || attrExpr->get_expr() ) {
999 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
1000 // check if the type is function
1001 if ( FunctionType *function = dynamic_cast< FunctionType* >( (*i)->get_type() ) ) {
1002 // assume exactly one parameter
1003 if ( function->get_parameters().size() == 1 ) {
1004 if ( attrExpr->get_isType() ) {
1005 resolveAttr( *i, function, attrExpr->get_type(), env );
1006 } else {
1007 AlternativeFinder finder( indexer, env );
1008 finder.find( attrExpr->get_expr() );
1009 for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
1010 if ( choice->expr->get_result()->size() == 1 ) {
1011 resolveAttr(*i, function, choice->expr->get_result(), choice->env );
1012 } // fi
1013 } // for
1014 } // if
1015 } // if
1016 } // if
1017 } // for
1018 } else {
1019 for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
1020 VariableExpr newExpr( *i );
1021 alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
1022 renameTypes( alternatives.back().expr );
1023 } // for
1024 } // if
1025 }
1026
1027 void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
1028 AlternativeFinder firstFinder( indexer, env );
1029 firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
1030 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
1031 AlternativeFinder secondFinder( indexer, first->env );
1032 secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
1033 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
1034 LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
1035 alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
1036 }
1037 }
1038 }
1039
1040 void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
1041 AlternativeFinder firstFinder( indexer, env );
1042 firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
1043 for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
1044 AlternativeFinder secondFinder( indexer, first->env );
1045 secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
1046 for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
1047 AlternativeFinder thirdFinder( indexer, second->env );
1048 thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
1049 for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
1050 OpenVarSet openVars;
1051 AssertionSet needAssertions, haveAssertions;
1052 Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
1053 Type* commonType = nullptr;
1054 if ( unify( second->expr->get_result(), third->expr->get_result(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
1055 ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
1056 newExpr->set_result( commonType ? commonType : second->expr->get_result()->clone() );
1057 newAlt.expr = newExpr;
1058 inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
1059 } // if
1060 } // for
1061 } // for
1062 } // for
1063 }
1064
1065 void AlternativeFinder::visit( CommaExpr *commaExpr ) {
1066 TypeEnvironment newEnv( env );
1067 Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
1068 AlternativeFinder secondFinder( indexer, newEnv );
1069 secondFinder.findWithAdjustment( commaExpr->get_arg2() );
1070 for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
1071 alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
1072 } // for
1073 delete newFirstArg;
1074 }
1075
1076 void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
1077 std::list< AlternativeFinder > subExprAlternatives;
1078 findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
1079 std::list< AltList > possibilities;
1080 combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
1081 for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
1082 TupleExpr *newExpr = new TupleExpr;
1083 makeExprList( *i, newExpr->get_exprs() );
1084 newExpr->set_result( Tuples::makeTupleType( newExpr->get_exprs() ) );
1085
1086 TypeEnvironment compositeEnv;
1087 simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1088 alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1089 } // for
1090 }
1091
1092 void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1093 alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1094 }
1095
1096 void AlternativeFinder::visit( ConstructorExpr * ctorExpr ) {
1097 AlternativeFinder finder( indexer, env );
1098 // don't prune here, since it's guaranteed all alternatives will have the same type
1099 // (giving the alternatives different types is half of the point of ConstructorExpr nodes)
1100 finder.findWithAdjustment( ctorExpr->get_callExpr(), false );
1101 for ( Alternative & alt : finder.alternatives ) {
1102 alternatives.push_back( Alternative( new ConstructorExpr( alt.expr->clone() ), alt.env, alt.cost ) );
1103 }
1104 }
1105
1106 void AlternativeFinder::visit( TupleIndexExpr *tupleExpr ) {
1107 alternatives.push_back( Alternative( tupleExpr->clone(), env, Cost::zero ) );
1108 }
1109
1110 void AlternativeFinder::visit( TupleAssignExpr *tupleAssignExpr ) {
1111 alternatives.push_back( Alternative( tupleAssignExpr->clone(), env, Cost::zero ) );
1112 }
1113
1114 void AlternativeFinder::visit( UniqueExpr *unqExpr ) {
1115 AlternativeFinder finder( indexer, env );
1116 finder.findWithAdjustment( unqExpr->get_expr() );
1117 for ( Alternative & alt : finder.alternatives ) {
1118 // ensure that the id is passed on to the UniqueExpr alternative so that the expressions are "linked"
1119 UniqueExpr * newUnqExpr = new UniqueExpr( alt.expr->clone(), unqExpr->get_id() );
1120 alternatives.push_back( Alternative( newUnqExpr, alt.env, alt.cost ) );
1121 }
1122 }
1123
1124} // namespace ResolvExpr
1125
1126// Local Variables: //
1127// tab-width: 4 //
1128// mode: c++ //
1129// compile-command: "make install" //
1130// End: //
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