source: src/ResolvExpr/Resolver.cc@ 342146e1

ADT arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 342146e1 was 5170d95, checked in by Peter A. Buhr <pabuhr@…>, 7 years ago

fix implict void cast problem
  • Property mode set to 100644
File size: 34.4 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// Resolver.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:17:01 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Tue Feb 19 18:09:56 2019
13// Update Count : 240
14//
15
16#include <cassert> // for strict_dynamic_cast, assert
17#include <memory> // for allocator, allocator_traits<...
18#include <tuple> // for get
19#include <vector> // for vector
20
21#include "Alternative.h" // for Alternative, AltList
22#include "AlternativeFinder.h" // for AlternativeFinder, resolveIn...
23#include "Common/PassVisitor.h" // for PassVisitor
24#include "Common/SemanticError.h" // for SemanticError
25#include "Common/utility.h" // for ValueGuard, group_iterate
26#include "CurrentObject.h" // for CurrentObject
27#include "InitTweak/GenInit.h"
28#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
29#include "RenameVars.h" // for RenameVars, global_renamer
30#include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment
31#include "Resolver.h"
32#include "ResolvMode.h" // for ResolvMode
33#include "SymTab/Autogen.h" // for SizeType
34#include "SymTab/Indexer.h" // for Indexer
35#include "SynTree/Declaration.h" // for ObjectDecl, TypeDecl, Declar...
36#include "SynTree/Expression.h" // for Expression, CastExpr, InitExpr
37#include "SynTree/Initializer.h" // for ConstructorInit, SingleInit
38#include "SynTree/Statement.h" // for ForStmt, Statement, BranchStmt
39#include "SynTree/Type.h" // for Type, BasicType, PointerType
40#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
41#include "SynTree/Visitor.h" // for acceptAll, maybeAccept
42#include "Tuples/Tuples.h"
43#include "typeops.h" // for extractResultType
44#include "Unify.h" // for unify
45
46using namespace std;
47
48namespace ResolvExpr {
49 struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
50 Resolver() {}
51 Resolver( const SymTab::Indexer & other ) {
52 indexer = other;
53 }
54
55 void previsit( FunctionDecl * functionDecl );
56 void postvisit( FunctionDecl * functionDecl );
57 void previsit( ObjectDecl * objectDecll );
58 void previsit( EnumDecl * enumDecl );
59 void previsit( StaticAssertDecl * assertDecl );
60
61 void previsit( ArrayType * at );
62 void previsit( PointerType * at );
63
64 void previsit( ExprStmt * exprStmt );
65 void previsit( AsmExpr * asmExpr );
66 void previsit( AsmStmt * asmStmt );
67 void previsit( IfStmt * ifStmt );
68 void previsit( WhileStmt * whileStmt );
69 void previsit( ForStmt * forStmt );
70 void previsit( SwitchStmt * switchStmt );
71 void previsit( CaseStmt * caseStmt );
72 void previsit( BranchStmt * branchStmt );
73 void previsit( ReturnStmt * returnStmt );
74 void previsit( ThrowStmt * throwStmt );
75 void previsit( CatchStmt * catchStmt );
76 void previsit( WaitForStmt * stmt );
77
78 void previsit( SingleInit * singleInit );
79 void previsit( ListInit * listInit );
80 void previsit( ConstructorInit * ctorInit );
81 private:
82 typedef std::list< Initializer * >::iterator InitIterator;
83
84 template< typename PtrType >
85 void handlePtrType( PtrType * type );
86
87 void fallbackInit( ConstructorInit * ctorInit );
88
89 Type * functionReturn = nullptr;
90 CurrentObject currentObject = nullptr;
91 bool inEnumDecl = false;
92 };
93
94 struct ResolveWithExprs : public WithIndexer, public WithGuards, public WithVisitorRef<ResolveWithExprs>, public WithShortCircuiting, public WithStmtsToAdd {
95 void previsit( FunctionDecl * );
96 void previsit( WithStmt * );
97
98 void resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts );
99 };
100
101 void resolve( std::list< Declaration * > translationUnit ) {
102 PassVisitor<Resolver> resolver;
103 acceptAll( translationUnit, resolver );
104 }
105
106 void resolveDecl( Declaration * decl, const SymTab::Indexer & indexer ) {
107 PassVisitor<Resolver> resolver( indexer );
108 maybeAccept( decl, resolver );
109 }
110
111 namespace {
112 struct DeleteFinder : public WithShortCircuiting {
113 DeletedExpr * delExpr = nullptr;
114 void previsit( DeletedExpr * expr ) {
115 if ( delExpr ) visit_children = false;
116 else delExpr = expr;
117 }
118
119 void previsit( Expression * ) {
120 if ( delExpr ) visit_children = false;
121 }
122 };
123 }
124
125 DeletedExpr * findDeletedExpr( Expression * expr ) {
126 PassVisitor<DeleteFinder> finder;
127 expr->accept( finder );
128 return finder.pass.delExpr;
129 }
130
131 namespace {
132 struct StripCasts {
133 Expression * postmutate( CastExpr * castExpr ) {
134 if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
135 // generated cast is to the same type as its argument, so it's unnecessary -- remove it
136 Expression * expr = castExpr->arg;
137 castExpr->arg = nullptr;
138 std::swap( expr->env, castExpr->env );
139 return expr;
140 }
141 return castExpr;
142 }
143
144 static void strip( Expression *& expr ) {
145 PassVisitor<StripCasts> stripper;
146 expr = expr->acceptMutator( stripper );
147 }
148 };
149
150 void finishExpr( Expression *& expr, const TypeEnvironment & env, TypeSubstitution * oldenv = nullptr ) {
151 expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
152 env.makeSubstitution( *expr->env );
153 StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
154 }
155
156 void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
157 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
158 if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
159 // cast is to the same type as its argument, so it's unnecessary -- remove it
160 expr = castExpr->arg;
161 castExpr->arg = nullptr;
162 std::swap( expr->env, castExpr->env );
163 delete castExpr;
164 }
165 }
166 }
167 } // namespace
168
169 namespace {
170 void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{} ) {
171 assertf( untyped, "expected a non-null expression." );
172
173 // xxx - this isn't thread-safe, but should work until we parallelize the resolver
174 static unsigned recursion_level = 0;
175
176 ++recursion_level;
177 TypeEnvironment env;
178 AlternativeFinder finder( indexer, env );
179 finder.find( untyped, recursion_level == 1 ? mode.atTopLevel() : mode );
180 --recursion_level;
181
182 #if 0
183 if ( finder.get_alternatives().size() != 1 ) {
184 std::cerr << "untyped expr is ";
185 untyped->print( std::cerr );
186 std::cerr << std::endl << "alternatives are:";
187 for ( const Alternative & alt : finder.get_alternatives() ) {
188 alt.print( std::cerr );
189 } // for
190 } // if
191 #endif
192
193 // produce filtered list of alternatives
194 AltList candidates;
195 for ( Alternative & alt : finder.get_alternatives() ) {
196 if ( pred( alt ) ) {
197 candidates.push_back( std::move( alt ) );
198 }
199 }
200
201 // produce invalid error if no candidates
202 if ( candidates.empty() ) {
203 SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
204 }
205
206 // search for cheapest candidate
207 AltList winners;
208 bool seen_undeleted = false;
209 for ( unsigned i = 0; i < candidates.size(); ++i ) {
210 int c = winners.empty() ? -1 : candidates[i].cost.compare( winners.front().cost );
211
212 if ( c > 0 ) continue; // skip more expensive than winner
213
214 if ( c < 0 ) {
215 // reset on new cheapest
216 seen_undeleted = ! findDeletedExpr( candidates[i].expr );
217 winners.clear();
218 } else /* if ( c == 0 ) */ {
219 if ( findDeletedExpr( candidates[i].expr ) ) {
220 // skip deleted expression if already seen one equivalent-cost not
221 if ( seen_undeleted ) continue;
222 } else if ( ! seen_undeleted ) {
223 // replace list of equivalent-cost deleted expressions with one non-deleted
224 winners.clear();
225 seen_undeleted = true;
226 }
227 }
228
229 winners.emplace_back( std::move( candidates[i] ) );
230 }
231
232 // promote alternative.cvtCost to .cost
233 // xxx - I don't know why this is done, but I'm keeping the behaviour from findMinCost
234 for ( Alternative& winner : winners ) {
235 winner.cost = winner.cvtCost;
236 }
237
238 // produce ambiguous errors, if applicable
239 if ( winners.size() != 1 ) {
240 std::ostringstream stream;
241 stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
242 untyped->print( stream );
243 stream << " Alternatives are:\n";
244 printAlts( winners, stream, 1 );
245 SemanticError( untyped->location, stream.str() );
246 }
247
248 // single selected choice
249 Alternative& choice = winners.front();
250
251 // fail on only expression deleted
252 if ( ! seen_undeleted ) {
253 SemanticError( untyped->location, choice.expr, "Unique best alternative includes deleted identifier in " );
254 }
255
256 // xxx - check for ambiguous expressions
257
258 // output selected choice
259 alt = std::move( choice );
260 }
261
262 /// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
263 void findKindExpression(Expression *& untyped, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{}) {
264 if ( ! untyped ) return;
265 Alternative choice;
266 findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, mode );
267 finishExpr( choice.expr, choice.env, untyped->env );
268 delete untyped;
269 untyped = choice.expr;
270 choice.expr = nullptr;
271 }
272
273 bool standardAlternativeFilter( const Alternative & ) {
274 // currently don't need to filter, under normal circumstances.
275 // in the future, this may be useful for removing deleted expressions
276 return true;
277 }
278 } // namespace
279
280 // used in resolveTypeof
281 Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer ) {
282 TypeEnvironment env;
283 return resolveInVoidContext( expr, indexer, env );
284 }
285
286 Expression * resolveInVoidContext( Expression * expr, const SymTab::Indexer & indexer, TypeEnvironment & env ) {
287 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
288 // interpretations, an exception has already been thrown.
289 assertf( expr, "expected a non-null expression." );
290
291 CastExpr * untyped = new CastExpr( expr ); // cast to void
292 untyped->location = expr->location;
293
294 // set up and resolve expression cast to void
295 Alternative choice;
296 findUnfinishedKindExpression( untyped, choice, indexer, "", standardAlternativeFilter, ResolvMode::withAdjustment() );
297 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
298 assert( castExpr );
299 env = std::move( choice.env );
300
301 // clean up resolved expression
302 Expression * ret = castExpr->arg;
303 castExpr->arg = nullptr;
304
305 // unlink the arg so that it isn't deleted twice at the end of the program
306 untyped->arg = nullptr;
307 return ret;
308 }
309
310 void findVoidExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
311 resetTyVarRenaming();
312 TypeEnvironment env;
313 Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
314 finishExpr( newExpr, env, untyped->env );
315 delete untyped;
316 untyped = newExpr;
317 }
318
319 void findSingleExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
320 findKindExpression( untyped, indexer, "", standardAlternativeFilter );
321 }
322
323 void findSingleExpression( Expression *& untyped, Type * type, const SymTab::Indexer & indexer ) {
324 assert( untyped && type );
325 // transfer location to generated cast for error purposes
326 CodeLocation location = untyped->location;
327 untyped = new CastExpr( untyped, type );
328 untyped->location = location;
329 findSingleExpression( untyped, indexer );
330 removeExtraneousCast( untyped, indexer );
331 }
332
333 namespace {
334 bool isIntegralType( const Alternative & alt ) {
335 Type * type = alt.expr->result;
336 if ( dynamic_cast< EnumInstType * >( type ) ) {
337 return true;
338 } else if ( BasicType * bt = dynamic_cast< BasicType * >( type ) ) {
339 return bt->isInteger();
340 } else if ( dynamic_cast< ZeroType* >( type ) != nullptr || dynamic_cast< OneType* >( type ) != nullptr ) {
341 return true;
342 } else {
343 return false;
344 } // if
345 }
346
347 void findIntegralExpression( Expression *& untyped, const SymTab::Indexer & indexer ) {
348 findKindExpression( untyped, indexer, "condition", isIntegralType );
349 }
350 }
351
352
353 bool isStructOrUnion( const Alternative & alt ) {
354 Type * t = alt.expr->result->stripReferences();
355 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
356 }
357
358 void resolveWithExprs( std::list< Declaration * > & translationUnit ) {
359 PassVisitor<ResolveWithExprs> resolver;
360 acceptAll( translationUnit, resolver );
361 }
362
363 void ResolveWithExprs::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
364 for ( Expression *& expr : withExprs ) {
365 // only struct- and union-typed expressions are viable candidates
366 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
367
368 // if with expression might be impure, create a temporary so that it is evaluated once
369 if ( Tuples::maybeImpure( expr ) ) {
370 static UniqueName tmpNamer( "_with_tmp_" );
371 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
372 expr = new VariableExpr( tmp );
373 newStmts.push_back( new DeclStmt( tmp ) );
374 if ( InitTweak::isConstructable( tmp->type ) ) {
375 // generate ctor/dtor and resolve them
376 tmp->init = InitTweak::genCtorInit( tmp );
377 tmp->accept( *visitor );
378 }
379 }
380 }
381 }
382
383 void ResolveWithExprs::previsit( WithStmt * withStmt ) {
384 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
385 }
386
387 void ResolveWithExprs::previsit( FunctionDecl * functionDecl ) {
388 {
389 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
390 // front of the function body.
391 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
392 indexer.addFunctionType( functionDecl->type );
393 std::list< Statement * > newStmts;
394 resolveWithExprs( functionDecl->withExprs, newStmts );
395 if ( functionDecl->statements ) {
396 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
397 } else {
398 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
399 }
400 }
401 }
402
403 void Resolver::previsit( ObjectDecl * objectDecl ) {
404 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that
405 // class-variable initContext is changed multiple time because the LHS is analysed twice.
406 // The second analysis changes initContext because of a function type can contain object
407 // declarations in the return and parameter types. So each value of initContext is
408 // retained, so the type on the first analysis is preserved and used for selecting the RHS.
409 GuardValue( currentObject );
410 currentObject = CurrentObject( objectDecl->get_type() );
411 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
412 // enumerator initializers should not use the enum type to initialize, since
413 // the enum type is still incomplete at this point. Use signed int instead.
414 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
415 }
416 }
417
418 template< typename PtrType >
419 void Resolver::handlePtrType( PtrType * type ) {
420 if ( type->get_dimension() ) {
421 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
422 }
423 }
424
425 void Resolver::previsit( ArrayType * at ) {
426 handlePtrType( at );
427 }
428
429 void Resolver::previsit( PointerType * pt ) {
430 handlePtrType( pt );
431 }
432
433 void Resolver::previsit( FunctionDecl * functionDecl ) {
434#if 0
435 std::cerr << "resolver visiting functiondecl ";
436 functionDecl->print( std::cerr );
437 std::cerr << std::endl;
438#endif
439 GuardValue( functionReturn );
440 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
441 }
442
443 void Resolver::postvisit( FunctionDecl * functionDecl ) {
444 // default value expressions have an environment which shouldn't be there and trips up
445 // later passes.
446 // xxx - it might be necessary to somehow keep the information from this environment, but I
447 // can't currently see how it's useful.
448 for ( Declaration * d : functionDecl->type->parameters ) {
449 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
450 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
451 delete init->value->env;
452 init->value->env = nullptr;
453 }
454 }
455 }
456 }
457
458 void Resolver::previsit( EnumDecl * ) {
459 // in case we decide to allow nested enums
460 GuardValue( inEnumDecl );
461 inEnumDecl = true;
462 }
463
464 void Resolver::previsit( StaticAssertDecl * assertDecl ) {
465 findIntegralExpression( assertDecl->condition, indexer );
466 }
467
468 void Resolver::previsit( ExprStmt * exprStmt ) {
469 visit_children = false;
470 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
471 findVoidExpression( exprStmt->expr, indexer );
472 }
473
474 void Resolver::previsit( AsmExpr * asmExpr ) {
475 visit_children = false;
476 findVoidExpression( asmExpr->operand, indexer );
477 if ( asmExpr->get_inout() ) {
478 findVoidExpression( asmExpr->inout, indexer );
479 } // if
480 }
481
482 void Resolver::previsit( AsmStmt * asmStmt ) {
483 visit_children = false;
484 acceptAll( asmStmt->get_input(), *visitor );
485 acceptAll( asmStmt->get_output(), *visitor );
486 }
487
488 void Resolver::previsit( IfStmt * ifStmt ) {
489 findIntegralExpression( ifStmt->condition, indexer );
490 }
491
492 void Resolver::previsit( WhileStmt * whileStmt ) {
493 findIntegralExpression( whileStmt->condition, indexer );
494 }
495
496 void Resolver::previsit( ForStmt * forStmt ) {
497 if ( forStmt->condition ) {
498 findIntegralExpression( forStmt->condition, indexer );
499 } // if
500
501 if ( forStmt->increment ) {
502 findVoidExpression( forStmt->increment, indexer );
503 } // if
504 }
505
506 void Resolver::previsit( SwitchStmt * switchStmt ) {
507 GuardValue( currentObject );
508 findIntegralExpression( switchStmt->condition, indexer );
509
510 currentObject = CurrentObject( switchStmt->condition->result );
511 }
512
513 void Resolver::previsit( CaseStmt * caseStmt ) {
514 if ( caseStmt->condition ) {
515 std::list< InitAlternative > initAlts = currentObject.getOptions();
516 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
517 // must remove cast from case statement because RangeExpr cannot be cast.
518 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
519 findSingleExpression( newExpr, indexer );
520 // case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
521 // Ideally we would perform the conversion internally here.
522 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
523 newExpr = castExpr->arg;
524 castExpr->arg = nullptr;
525 std::swap( newExpr->env, castExpr->env );
526 delete castExpr;
527 }
528 caseStmt->condition = newExpr;
529 }
530 }
531
532 void Resolver::previsit( BranchStmt * branchStmt ) {
533 visit_children = false;
534 // must resolve the argument for a computed goto
535 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
536 if ( branchStmt->computedTarget ) {
537 // computed goto argument is void *
538 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
539 } // if
540 } // if
541 }
542
543 void Resolver::previsit( ReturnStmt * returnStmt ) {
544 visit_children = false;
545 if ( returnStmt->expr ) {
546 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
547 } // if
548 }
549
550 void Resolver::previsit( ThrowStmt * throwStmt ) {
551 visit_children = false;
552 // TODO: Replace *exception type with &exception type.
553 if ( throwStmt->get_expr() ) {
554 StructDecl * exception_decl =
555 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
556 assert( exception_decl );
557 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
558 findSingleExpression( throwStmt->expr, exceptType, indexer );
559 }
560 }
561
562 void Resolver::previsit( CatchStmt * catchStmt ) {
563 if ( catchStmt->cond ) {
564 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
565 }
566 }
567
568 template< typename iterator_t >
569 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
570 while( it != end && !(*it)->get_type()->get_mutex() ) {
571 it++;
572 }
573
574 return it != end;
575 }
576
577 void Resolver::previsit( WaitForStmt * stmt ) {
578 visit_children = false;
579
580 // Resolve all clauses first
581 for( auto& clause : stmt->clauses ) {
582
583 TypeEnvironment env;
584 AlternativeFinder funcFinder( indexer, env );
585
586 // Find all alternatives for a function in canonical form
587 funcFinder.findWithAdjustment( clause.target.function );
588
589 if ( funcFinder.get_alternatives().empty() ) {
590 stringstream ss;
591 ss << "Use of undeclared indentifier '";
592 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
593 ss << "' in call to waitfor";
594 SemanticError( stmt->location, ss.str() );
595 }
596
597 if(clause.target.arguments.empty()) {
598 SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
599 }
600
601 // Find all alternatives for all arguments in canonical form
602 std::vector< AlternativeFinder > argAlternatives;
603 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
604
605 // List all combinations of arguments
606 std::vector< AltList > possibilities;
607 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
608
609 AltList func_candidates;
610 std::vector< AltList > args_candidates;
611
612 // For every possible function :
613 // try matching the arguments to the parameters
614 // not the other way around because we have more arguments than parameters
615 SemanticErrorException errors;
616 for ( Alternative & func : funcFinder.get_alternatives() ) {
617 try {
618 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
619 if( !pointer ) {
620 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
621 }
622
623 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
624 if( !function ) {
625 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
626 }
627
628
629 {
630 auto param = function->parameters.begin();
631 auto param_end = function->parameters.end();
632
633 if( !advance_to_mutex( param, param_end ) ) {
634 SemanticError(function, "candidate function not viable: no mutex parameters\n");
635 }
636 }
637
638 Alternative newFunc( func );
639 // Strip reference from function
640 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
641
642 // For all the set of arguments we have try to match it with the parameter of the current function alternative
643 for ( auto & argsList : possibilities ) {
644
645 try {
646 // Declare data structures need for resolution
647 OpenVarSet openVars;
648 AssertionSet resultNeed, resultHave;
649 TypeEnvironment resultEnv( func.env );
650 makeUnifiableVars( function, openVars, resultNeed );
651 // add all type variables as open variables now so that those not used in the parameter
652 // list are still considered open.
653 resultEnv.add( function->forall );
654
655 // Load type variables from arguemnts into one shared space
656 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
657
658 // Make sure we don't widen any existing bindings
659 resultEnv.forbidWidening();
660
661 // Find any unbound type variables
662 resultEnv.extractOpenVars( openVars );
663
664 auto param = function->parameters.begin();
665 auto param_end = function->parameters.end();
666
667 int n_mutex_param = 0;
668
669 // For every arguments of its set, check if it matches one of the parameter
670 // The order is important
671 for( auto & arg : argsList ) {
672
673 // Ignore non-mutex arguments
674 if( !advance_to_mutex( param, param_end ) ) {
675 // We ran out of parameters but still have arguments
676 // this function doesn't match
677 SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_param, "\n" ));
678 }
679
680 n_mutex_param++;
681
682 // Check if the argument matches the parameter type in the current scope
683 if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
684 // Type doesn't match
685 stringstream ss;
686 ss << "candidate function not viable: no known convertion from '";
687 (*param)->get_type()->print( ss );
688 ss << "' to '";
689 arg.expr->get_result()->print( ss );
690 ss << "' with env '";
691 resultEnv.print(ss);
692 ss << "'\n";
693 SemanticError( function, ss.str() );
694 }
695
696 param++;
697 }
698
699 // All arguments match !
700
701 // Check if parameters are missing
702 if( advance_to_mutex( param, param_end ) ) {
703 do {
704 n_mutex_param++;
705 param++;
706 } while( advance_to_mutex( param, param_end ) );
707
708 // We ran out of arguments but still have parameters left
709 // this function doesn't match
710 SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_param, "\n" ));
711 }
712
713 // All parameters match !
714
715 // Finish the expressions to tie in the proper environments
716 finishExpr( newFunc.expr, resultEnv );
717 for( Alternative & alt : argsList ) {
718 finishExpr( alt.expr, resultEnv );
719 }
720
721 // This is a match store it and save it for later
722 func_candidates.push_back( newFunc );
723 args_candidates.push_back( argsList );
724
725 }
726 catch( SemanticErrorException & e ) {
727 errors.append( e );
728 }
729 }
730 }
731 catch( SemanticErrorException & e ) {
732 errors.append( e );
733 }
734 }
735
736 // Make sure we got the right number of arguments
737 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
738 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
739 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
740 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
741 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
742
743 // Swap the results from the alternative with the unresolved values.
744 // Alternatives will handle deletion on destruction
745 std::swap( clause.target.function, func_candidates.front().expr );
746 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
747 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
748 }
749
750 // Resolve the conditions as if it were an IfStmt
751 // Resolve the statments normally
752 findSingleExpression( clause.condition, this->indexer );
753 clause.statement->accept( *visitor );
754 }
755
756
757 if( stmt->timeout.statement ) {
758 // Resolve the timeout as an size_t for now
759 // Resolve the conditions as if it were an IfStmt
760 // Resolve the statments normally
761 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
762 findSingleExpression( stmt->timeout.condition, this->indexer );
763 stmt->timeout.statement->accept( *visitor );
764 }
765
766 if( stmt->orelse.statement ) {
767 // Resolve the conditions as if it were an IfStmt
768 // Resolve the statments normally
769 findSingleExpression( stmt->orelse.condition, this->indexer );
770 stmt->orelse.statement->accept( *visitor );
771 }
772 }
773
774 template< typename T >
775 bool isCharType( T t ) {
776 if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
777 return bt->get_kind() == BasicType::Char || bt->get_kind() == BasicType::SignedChar ||
778 bt->get_kind() == BasicType::UnsignedChar;
779 }
780 return false;
781 }
782
783 void Resolver::previsit( SingleInit * singleInit ) {
784 visit_children = false;
785 // resolve initialization using the possibilities as determined by the currentObject cursor
786 Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
787 findSingleExpression( newExpr, indexer );
788 InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
789
790 // move cursor to the object that is actually initialized
791 currentObject.setNext( initExpr->get_designation() );
792
793 // discard InitExpr wrapper and retain relevant pieces
794 newExpr = initExpr->expr;
795 initExpr->expr = nullptr;
796 std::swap( initExpr->env, newExpr->env );
797 // InitExpr may have inferParams in the case where the expression specializes a function
798 // pointer, and newExpr may already have inferParams of its own, so a simple swap is not
799 // sufficient.
800 newExpr->spliceInferParams( initExpr );
801 delete initExpr;
802
803 // get the actual object's type (may not exactly match what comes back from the resolver
804 // due to conversions)
805 Type * initContext = currentObject.getCurrentType();
806
807 removeExtraneousCast( newExpr, indexer );
808
809 // check if actual object's type is char[]
810 if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
811 if ( isCharType( at->get_base() ) ) {
812 // check if the resolved type is char *
813 if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
814 if ( isCharType( pt->get_base() ) ) {
815 if ( CastExpr * ce = dynamic_cast< CastExpr * >( newExpr ) ) {
816 // strip cast if we're initializing a char[] with a char *,
817 // e.g. char x[] = "hello";
818 newExpr = ce->get_arg();
819 ce->set_arg( nullptr );
820 std::swap( ce->env, newExpr->env );
821 delete ce;
822 }
823 }
824 }
825 }
826 }
827
828 // set initializer expr to resolved express
829 singleInit->value = newExpr;
830
831 // move cursor to next object in preparation for next initializer
832 currentObject.increment();
833 }
834
835 void Resolver::previsit( ListInit * listInit ) {
836 visit_children = false;
837 // move cursor into brace-enclosed initializer-list
838 currentObject.enterListInit();
839 // xxx - fix this so that the list isn't copied, iterator should be used to change current
840 // element
841 std::list<Designation *> newDesignations;
842 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
843 // iterate designations and initializers in pairs, moving the cursor to the current
844 // designated object and resolving the initializer against that object.
845 Designation * des = std::get<0>(p);
846 Initializer * init = std::get<1>(p);
847 newDesignations.push_back( currentObject.findNext( des ) );
848 init->accept( *visitor );
849 }
850 // set the set of 'resolved' designations and leave the brace-enclosed initializer-list
851 listInit->get_designations() = newDesignations; // xxx - memory management
852 currentObject.exitListInit();
853
854 // xxx - this part has not be folded into CurrentObject yet
855 // } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
856 // Type * base = tt->get_baseType()->get_base();
857 // if ( base ) {
858 // // know the implementation type, so try using that as the initContext
859 // ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
860 // currentObject = &tmpObj;
861 // visit( listInit );
862 // } else {
863 // // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
864 // Parent::visit( listInit );
865 // }
866 // } else {
867 }
868
869 // ConstructorInit - fall back on C-style initializer
870 void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
871 // could not find valid constructor, or found an intrinsic constructor
872 // fall back on C-style initializer
873 delete ctorInit->get_ctor();
874 ctorInit->set_ctor( nullptr );
875 delete ctorInit->get_dtor();
876 ctorInit->set_dtor( nullptr );
877 maybeAccept( ctorInit->get_init(), *visitor );
878 }
879
880 // needs to be callable from outside the resolver, so this is a standalone function
881 void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
882 assert( ctorInit );
883 PassVisitor<Resolver> resolver( indexer );
884 ctorInit->accept( resolver );
885 }
886
887 void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
888 assert( stmtExpr );
889 PassVisitor<Resolver> resolver( indexer );
890 stmtExpr->accept( resolver );
891 stmtExpr->computeResult();
892 // xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
893 }
894
895 void Resolver::previsit( ConstructorInit * ctorInit ) {
896 visit_children = false;
897 // xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
898 maybeAccept( ctorInit->ctor, *visitor );
899 maybeAccept( ctorInit->dtor, *visitor );
900
901 // found a constructor - can get rid of C-style initializer
902 delete ctorInit->init;
903 ctorInit->init = nullptr;
904
905 // intrinsic single parameter constructors and destructors do nothing. Since this was
906 // implicitly generated, there's no way for it to have side effects, so get rid of it
907 // to clean up generated code.
908 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
909 delete ctorInit->ctor;
910 ctorInit->ctor = nullptr;
911 }
912
913 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
914 delete ctorInit->dtor;
915 ctorInit->dtor = nullptr;
916 }
917
918 // xxx - todo -- what about arrays?
919 // if ( dtor == nullptr && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
920 // // can reduce the constructor down to a SingleInit using the
921 // // second argument from the ctor call, since
922 // delete ctorInit->get_ctor();
923 // ctorInit->set_ctor( nullptr );
924
925 // Expression * arg =
926 // ctorInit->set_init( new SingleInit( arg ) );
927 // }
928 }
929} // namespace ResolvExpr
930
931// Local Variables: //
932// tab-width: 4 //
933// mode: c++ //
934// compile-command: "make install" //
935// End: //
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