source: src/ResolvExpr/AlternativeFinder.cc@ 4c8621ac

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 4c8621ac was 4c8621ac, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

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