source: src/ResolvExpr/Resolver.cc@ 25fcb84

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 with_gc
Last change on this file since 25fcb84 was cdb990a, checked in by Rob Schluntz <rschlunt@…>, 7 years ago

Strip redundant casts after every resolution
  • Property mode set to 100644
File size: 32.9 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 : Sat Feb 17 11:19:40 2018
13// Update Count : 213
14//
15
16#include <stddef.h> // for NULL
17#include <cassert> // for strict_dynamic_cast, assert
18#include <memory> // for allocator, allocator_traits<...
19#include <tuple> // for get
20#include <vector>
21
22#include "Alternative.h" // for Alternative, AltList
23#include "AlternativeFinder.h" // for AlternativeFinder, resolveIn...
24#include "Common/PassVisitor.h" // for PassVisitor
25#include "Common/SemanticError.h" // for SemanticError
26#include "Common/utility.h" // for ValueGuard, group_iterate
27#include "CurrentObject.h" // for CurrentObject
28#include "InitTweak/GenInit.h"
29#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
30#include "RenameVars.h" // for RenameVars, global_renamer
31#include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment
32#include "ResolveTypeof.h" // for resolveTypeof
33#include "Resolver.h"
34#include "SymTab/Autogen.h" // for SizeType
35#include "SymTab/Indexer.h" // for Indexer
36#include "SynTree/Declaration.h" // for ObjectDecl, TypeDecl, Declar...
37#include "SynTree/Expression.h" // for Expression, CastExpr, InitExpr
38#include "SynTree/Initializer.h" // for ConstructorInit, SingleInit
39#include "SynTree/Statement.h" // for ForStmt, Statement, BranchStmt
40#include "SynTree/Type.h" // for Type, BasicType, PointerType
41#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
42#include "SynTree/Visitor.h" // for acceptAll, maybeAccept
43#include "Tuples/Tuples.h"
44#include "typeops.h" // for extractResultType
45#include "Unify.h" // for unify
46
47using namespace std;
48
49namespace ResolvExpr {
50 struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
51 Resolver() {}
52 Resolver( const SymTab::Indexer & other ) {
53 indexer = other;
54 }
55
56 void previsit( FunctionDecl *functionDecl );
57 void postvisit( FunctionDecl *functionDecl );
58 void previsit( ObjectDecl *objectDecll );
59 void previsit( TypeDecl *typeDecl );
60 void previsit( EnumDecl * enumDecl );
61 void previsit( StaticAssertDecl * assertDecl );
62
63 void previsit( ArrayType * at );
64 void previsit( PointerType * at );
65
66 void previsit( ExprStmt *exprStmt );
67 void previsit( AsmExpr *asmExpr );
68 void previsit( AsmStmt *asmStmt );
69 void previsit( IfStmt *ifStmt );
70 void previsit( WhileStmt *whileStmt );
71 void previsit( ForStmt *forStmt );
72 void previsit( SwitchStmt *switchStmt );
73 void previsit( CaseStmt *caseStmt );
74 void previsit( BranchStmt *branchStmt );
75 void previsit( ReturnStmt *returnStmt );
76 void previsit( ThrowStmt *throwStmt );
77 void previsit( CatchStmt *catchStmt );
78 void previsit( WaitForStmt * stmt );
79 void previsit( WithStmt * withStmt );
80
81 void previsit( SingleInit *singleInit );
82 void previsit( ListInit *listInit );
83 void previsit( ConstructorInit *ctorInit );
84 private:
85 typedef std::list< Initializer * >::iterator InitIterator;
86
87 template< typename PtrType >
88 void handlePtrType( PtrType * type );
89
90 void resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts );
91 void fallbackInit( ConstructorInit * ctorInit );
92
93 Type * functionReturn = nullptr;
94 CurrentObject currentObject = nullptr;
95 bool inEnumDecl = false;
96 };
97
98 void resolve( std::list< Declaration * > translationUnit ) {
99 PassVisitor<Resolver> resolver;
100 acceptAll( translationUnit, resolver );
101 }
102
103 void resolveDecl( Declaration * decl, const SymTab::Indexer &indexer ) {
104 PassVisitor<Resolver> resolver( indexer );
105 maybeAccept( decl, resolver );
106 }
107
108 namespace {
109 struct DeleteFinder : public WithShortCircuiting {
110 DeletedExpr * delExpr = nullptr;
111 void previsit( DeletedExpr * expr ) {
112 if ( delExpr ) visit_children = false;
113 else delExpr = expr;
114 }
115
116 void previsit( Expression * ) {
117 if ( delExpr ) visit_children = false;
118 }
119 };
120 }
121
122 DeletedExpr * findDeletedExpr( Expression * expr ) {
123 PassVisitor<DeleteFinder> finder;
124 expr->accept( finder );
125 return finder.pass.delExpr;
126 }
127
128 namespace {
129 struct StripCasts {
130 Expression * postmutate( CastExpr * castExpr ) {
131 if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
132 // generated cast is to the same type as its argument, so it's unnecessary -- remove it
133 Expression * expr = castExpr->arg;
134 castExpr->arg = nullptr;
135 std::swap( expr->env, castExpr->env );
136 return expr;
137 }
138 return castExpr;
139 }
140
141 static void strip( Expression *& expr ) {
142 PassVisitor<StripCasts> stripper;
143 expr = expr->acceptMutator( stripper );
144 }
145 };
146
147 void finishExpr( Expression *&expr, const TypeEnvironment &env, TypeSubstitution * oldenv = nullptr ) {
148 expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
149 env.makeSubstitution( *expr->env );
150 StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
151 }
152
153 void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
154 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
155 if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
156 // cast is to the same type as its argument, so it's unnecessary -- remove it
157 expr = castExpr->arg;
158 castExpr->arg = nullptr;
159 std::swap( expr->env, castExpr->env );
160 delete castExpr;
161 }
162 }
163 }
164 } // namespace
165
166 namespace {
167 void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, bool adjust = false, bool prune = true, bool failFast = true) {
168 assertf( untyped, "expected a non-null expression." );
169 TypeEnvironment env;
170 AlternativeFinder finder( indexer, env );
171 finder.find( untyped, adjust, prune, failFast );
172
173 #if 0
174 if ( finder.get_alternatives().size() != 1 ) {
175 std::cerr << "untyped expr is ";
176 untyped->print( std::cerr );
177 std::cerr << std::endl << "alternatives are:";
178 for ( const Alternative & alt : finder.get_alternatives() ) {
179 alt.print( std::cerr );
180 } // for
181 } // if
182 #endif
183
184 AltList candidates;
185 for ( Alternative & alt : finder.get_alternatives() ) {
186 if ( pred( alt ) ) {
187 candidates.push_back( std::move( alt ) );
188 }
189 }
190
191 // xxx - if > 1 alternative with same cost, ignore deleted and pick from remaining
192 // choose the lowest cost expression among the candidates
193 AltList winners;
194 findMinCost( candidates.begin(), candidates.end(), back_inserter( winners ) );
195 if ( winners.size() == 0 ) {
196 SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
197 } else if ( winners.size() != 1 ) {
198 std::ostringstream stream;
199 stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
200 untyped->print( stream );
201 stream << " Alternatives are:\n";
202 printAlts( winners, stream, 1 );
203 SemanticError( untyped->location, stream.str() );
204 }
205
206 // there is one unambiguous interpretation - move the expression into the with statement
207 Alternative & choice = winners.front();
208 if ( findDeletedExpr( choice.expr ) ) {
209 SemanticError( choice.expr, "Unique best alternative includes deleted identifier in " );
210 }
211 alt = std::move( choice );
212 }
213
214 /// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
215 void findKindExpression(Expression *& untyped, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, bool adjust = false, bool prune = true, bool failFast = true) {
216 if ( ! untyped ) return;
217 Alternative choice;
218 findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, adjust, prune, failFast );
219 finishExpr( choice.expr, choice.env, untyped->env );
220 delete untyped;
221 untyped = choice.expr;
222 choice.expr = nullptr;
223 }
224
225 bool standardAlternativeFilter( const Alternative & ) {
226 // currently don't need to filter, under normal circumstances.
227 // in the future, this may be useful for removing deleted expressions
228 return true;
229 }
230 } // namespace
231
232 // used in resolveTypeof
233 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer ) {
234 TypeEnvironment env;
235 return resolveInVoidContext( expr, indexer, env );
236 }
237
238 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
239 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
240 // interpretations, an exception has already been thrown.
241 assertf( expr, "expected a non-null expression." );
242
243 static CastExpr untyped( nullptr ); // cast to void
244
245 // set up and resolve expression cast to void
246 untyped.arg = expr;
247 Alternative choice;
248 findUnfinishedKindExpression( &untyped, choice, indexer, "", standardAlternativeFilter, true );
249 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
250 env = std::move( choice.env );
251
252 // clean up resolved expression
253 Expression * ret = castExpr->arg;
254 castExpr->arg = nullptr;
255
256 // unlink the arg so that it isn't deleted twice at the end of the program
257 untyped.arg = nullptr;
258 return ret;
259 }
260
261 void findVoidExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
262 resetTyVarRenaming();
263 TypeEnvironment env;
264 Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
265 finishExpr( newExpr, env, untyped->env );
266 delete untyped;
267 untyped = newExpr;
268 }
269
270 void findSingleExpression( Expression *&untyped, const SymTab::Indexer &indexer ) {
271 findKindExpression( untyped, indexer, "", standardAlternativeFilter );
272 }
273
274 void findSingleExpression( Expression *& untyped, Type * type, const SymTab::Indexer & indexer ) {
275 assert( untyped && type );
276 untyped = new CastExpr( untyped, type );
277 findSingleExpression( untyped, indexer );
278 removeExtraneousCast( untyped, indexer );
279 }
280
281 namespace {
282 bool isIntegralType( const Alternative & alt ) {
283 Type * type = alt.expr->result;
284 if ( dynamic_cast< EnumInstType * >( type ) ) {
285 return true;
286 } else if ( BasicType *bt = dynamic_cast< BasicType * >( type ) ) {
287 return bt->isInteger();
288 } else if ( dynamic_cast< ZeroType* >( type ) != nullptr || dynamic_cast< OneType* >( type ) != nullptr ) {
289 return true;
290 } else {
291 return false;
292 } // if
293 }
294
295 void findIntegralExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
296 findKindExpression( untyped, indexer, "condition", isIntegralType );
297 }
298 }
299
300 void Resolver::previsit( ObjectDecl *objectDecl ) {
301 Type *new_type = resolveTypeof( objectDecl->get_type(), indexer );
302 objectDecl->set_type( new_type );
303 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
304 // initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
305 // initContext because of a function type can contain object declarations in the return and parameter types. So
306 // each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
307 // the RHS.
308 GuardValue( currentObject );
309 currentObject = CurrentObject( objectDecl->get_type() );
310 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
311 // enumerator initializers should not use the enum type to initialize, since
312 // the enum type is still incomplete at this point. Use signed int instead.
313 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
314 }
315 }
316
317 template< typename PtrType >
318 void Resolver::handlePtrType( PtrType * type ) {
319 if ( type->get_dimension() ) {
320 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
321 }
322 }
323
324 void Resolver::previsit( ArrayType * at ) {
325 handlePtrType( at );
326 }
327
328 void Resolver::previsit( PointerType * pt ) {
329 handlePtrType( pt );
330 }
331
332 void Resolver::previsit( TypeDecl *typeDecl ) {
333 if ( typeDecl->get_base() ) {
334 Type *new_type = resolveTypeof( typeDecl->get_base(), indexer );
335 typeDecl->set_base( new_type );
336 } // if
337 }
338
339 void Resolver::previsit( FunctionDecl *functionDecl ) {
340#if 0
341 std::cerr << "resolver visiting functiondecl ";
342 functionDecl->print( std::cerr );
343 std::cerr << std::endl;
344#endif
345 Type *new_type = resolveTypeof( functionDecl->type, indexer );
346 functionDecl->set_type( new_type );
347 GuardValue( functionReturn );
348 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
349
350 {
351 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
352 // front of the function body.
353 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
354 indexer.addFunctionType( functionDecl->type );
355 std::list< Statement * > newStmts;
356 resolveWithExprs( functionDecl->withExprs, newStmts );
357 if ( functionDecl->statements ) {
358 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
359 } else {
360 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
361 }
362 }
363 }
364
365 void Resolver::postvisit( FunctionDecl *functionDecl ) {
366 // default value expressions have an environment which shouldn't be there and trips up later passes.
367 // xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
368 // see how it's useful.
369 for ( Declaration * d : functionDecl->type->parameters ) {
370 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
371 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
372 delete init->value->env;
373 init->value->env = nullptr;
374 }
375 }
376 }
377 }
378
379 void Resolver::previsit( EnumDecl * ) {
380 // in case we decide to allow nested enums
381 GuardValue( inEnumDecl );
382 inEnumDecl = true;
383 }
384
385 void Resolver::previsit( StaticAssertDecl * assertDecl ) {
386 findIntegralExpression( assertDecl->condition, indexer );
387 }
388
389 void Resolver::previsit( ExprStmt *exprStmt ) {
390 visit_children = false;
391 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
392 findVoidExpression( exprStmt->expr, indexer );
393 }
394
395 void Resolver::previsit( AsmExpr *asmExpr ) {
396 visit_children = false;
397 findVoidExpression( asmExpr->operand, indexer );
398 if ( asmExpr->get_inout() ) {
399 findVoidExpression( asmExpr->inout, indexer );
400 } // if
401 }
402
403 void Resolver::previsit( AsmStmt *asmStmt ) {
404 visit_children = false;
405 acceptAll( asmStmt->get_input(), *visitor );
406 acceptAll( asmStmt->get_output(), *visitor );
407 }
408
409 void Resolver::previsit( IfStmt *ifStmt ) {
410 findIntegralExpression( ifStmt->condition, indexer );
411 }
412
413 void Resolver::previsit( WhileStmt *whileStmt ) {
414 findIntegralExpression( whileStmt->condition, indexer );
415 }
416
417 void Resolver::previsit( ForStmt *forStmt ) {
418 if ( forStmt->condition ) {
419 findIntegralExpression( forStmt->condition, indexer );
420 } // if
421
422 if ( forStmt->increment ) {
423 findVoidExpression( forStmt->increment, indexer );
424 } // if
425 }
426
427 void Resolver::previsit( SwitchStmt *switchStmt ) {
428 GuardValue( currentObject );
429 findIntegralExpression( switchStmt->condition, indexer );
430
431 currentObject = CurrentObject( switchStmt->condition->result );
432 }
433
434 void Resolver::previsit( CaseStmt *caseStmt ) {
435 if ( caseStmt->condition ) {
436 std::list< InitAlternative > initAlts = currentObject.getOptions();
437 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
438 // must remove cast from case statement because RangeExpr cannot be cast.
439 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
440 findSingleExpression( newExpr, indexer );
441 // case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
442 // Ideally we would perform the conversion internally here.
443 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
444 newExpr = castExpr->arg;
445 castExpr->arg = nullptr;
446 std::swap( newExpr->env, castExpr->env );
447 delete castExpr;
448 }
449 caseStmt->condition = newExpr;
450 }
451 }
452
453 void Resolver::previsit( BranchStmt *branchStmt ) {
454 visit_children = false;
455 // must resolve the argument for a computed goto
456 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
457 if ( branchStmt->computedTarget ) {
458 // computed goto argument is void *
459 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
460 } // if
461 } // if
462 }
463
464 void Resolver::previsit( ReturnStmt *returnStmt ) {
465 visit_children = false;
466 if ( returnStmt->expr ) {
467 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
468 } // if
469 }
470
471 void Resolver::previsit( ThrowStmt *throwStmt ) {
472 visit_children = false;
473 // TODO: Replace *exception type with &exception type.
474 if ( throwStmt->get_expr() ) {
475 StructDecl * exception_decl =
476 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
477 assert( exception_decl );
478 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
479 findSingleExpression( throwStmt->expr, exceptType, indexer );
480 }
481 }
482
483 void Resolver::previsit( CatchStmt *catchStmt ) {
484 if ( catchStmt->cond ) {
485 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
486 }
487 }
488
489 template< typename iterator_t >
490 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
491 while( it != end && !(*it)->get_type()->get_mutex() ) {
492 it++;
493 }
494
495 return it != end;
496 }
497
498 void Resolver::previsit( WaitForStmt * stmt ) {
499 visit_children = false;
500
501 // Resolve all clauses first
502 for( auto& clause : stmt->clauses ) {
503
504 TypeEnvironment env;
505 AlternativeFinder funcFinder( indexer, env );
506
507 // Find all alternatives for a function in canonical form
508 funcFinder.findWithAdjustment( clause.target.function );
509
510 if ( funcFinder.get_alternatives().empty() ) {
511 stringstream ss;
512 ss << "Use of undeclared indentifier '";
513 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
514 ss << "' in call to waitfor";
515 SemanticError( stmt->location, ss.str() );
516 }
517
518 if(clause.target.arguments.empty()) {
519 SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
520 }
521
522 // Find all alternatives for all arguments in canonical form
523 std::vector< AlternativeFinder > argAlternatives;
524 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
525
526 // List all combinations of arguments
527 std::vector< AltList > possibilities;
528 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
529
530 AltList func_candidates;
531 std::vector< AltList > args_candidates;
532
533 // For every possible function :
534 // try matching the arguments to the parameters
535 // not the other way around because we have more arguments than parameters
536 SemanticErrorException errors;
537 for ( Alternative & func : funcFinder.get_alternatives() ) {
538 try {
539 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
540 if( !pointer ) {
541 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
542 }
543
544 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
545 if( !function ) {
546 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
547 }
548
549
550 {
551 auto param = function->parameters.begin();
552 auto param_end = function->parameters.end();
553
554 if( !advance_to_mutex( param, param_end ) ) {
555 SemanticError(function, "candidate function not viable: no mutex parameters\n");
556 }
557 }
558
559 Alternative newFunc( func );
560 // Strip reference from function
561 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
562
563 // For all the set of arguments we have try to match it with the parameter of the current function alternative
564 for ( auto & argsList : possibilities ) {
565
566 try {
567 // Declare data structures need for resolution
568 OpenVarSet openVars;
569 AssertionSet resultNeed, resultHave;
570 TypeEnvironment resultEnv( func.env );
571 makeUnifiableVars( function, openVars, resultNeed );
572 // add all type variables as open variables now so that those not used in the parameter
573 // list are still considered open.
574 resultEnv.add( function->forall );
575
576 // Load type variables from arguemnts into one shared space
577 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
578
579 // Make sure we don't widen any existing bindings
580 for ( auto & i : resultEnv ) {
581 i.allowWidening = false;
582 }
583
584 // Find any unbound type variables
585 resultEnv.extractOpenVars( openVars );
586
587 auto param = function->parameters.begin();
588 auto param_end = function->parameters.end();
589
590 int n_mutex_arg = 0;
591
592 // For every arguments of its set, check if it matches one of the parameter
593 // The order is important
594 for( auto & arg : argsList ) {
595
596 // Ignore non-mutex arguments
597 if( !advance_to_mutex( param, param_end ) ) {
598 // We ran out of parameters but still have arguments
599 // this function doesn't match
600 SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_arg, "\n" ));
601 }
602
603 n_mutex_arg++;
604
605 // Check if the argument matches the parameter type in the current scope
606 if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
607 // Type doesn't match
608 stringstream ss;
609 ss << "candidate function not viable: no known convertion from '";
610 (*param)->get_type()->print( ss );
611 ss << "' to '";
612 arg.expr->get_result()->print( ss );
613 ss << "' with env '";
614 resultEnv.print(ss);
615 ss << "'\n";
616 SemanticError( function, ss.str() );
617 }
618
619 param++;
620 }
621
622 // All arguments match !
623
624 // Check if parameters are missing
625 if( advance_to_mutex( param, param_end ) ) {
626 // We ran out of arguments but still have parameters left
627 // this function doesn't match
628 SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_arg, "\n" ));
629 }
630
631 // All parameters match !
632
633 // Finish the expressions to tie in the proper environments
634 finishExpr( newFunc.expr, resultEnv );
635 for( Alternative & alt : argsList ) {
636 finishExpr( alt.expr, resultEnv );
637 }
638
639 // This is a match store it and save it for later
640 func_candidates.push_back( newFunc );
641 args_candidates.push_back( argsList );
642
643 }
644 catch( SemanticErrorException &e ) {
645 errors.append( e );
646 }
647 }
648 }
649 catch( SemanticErrorException &e ) {
650 errors.append( e );
651 }
652 }
653
654 // Make sure we got the right number of arguments
655 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
656 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
657 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
658 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
659 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
660
661 // Swap the results from the alternative with the unresolved values.
662 // Alternatives will handle deletion on destruction
663 std::swap( clause.target.function, func_candidates.front().expr );
664 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
665 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
666 }
667
668 // Resolve the conditions as if it were an IfStmt
669 // Resolve the statments normally
670 findSingleExpression( clause.condition, this->indexer );
671 clause.statement->accept( *visitor );
672 }
673
674
675 if( stmt->timeout.statement ) {
676 // Resolve the timeout as an size_t for now
677 // Resolve the conditions as if it were an IfStmt
678 // Resolve the statments normally
679 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
680 findSingleExpression( stmt->timeout.condition, this->indexer );
681 stmt->timeout.statement->accept( *visitor );
682 }
683
684 if( stmt->orelse.statement ) {
685 // Resolve the conditions as if it were an IfStmt
686 // Resolve the statments normally
687 findSingleExpression( stmt->orelse.condition, this->indexer );
688 stmt->orelse.statement->accept( *visitor );
689 }
690 }
691
692 bool isStructOrUnion( const Alternative & alt ) {
693 Type * t = alt.expr->result->stripReferences();
694 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
695 }
696
697 void Resolver::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
698 for ( Expression *& expr : withExprs ) {
699 // only struct- and union-typed expressions are viable candidates
700 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
701
702 // if with expression might be impure, create a temporary so that it is evaluated once
703 if ( Tuples::maybeImpure( expr ) ) {
704 static UniqueName tmpNamer( "_with_tmp_" );
705 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
706 expr = new VariableExpr( tmp );
707 newStmts.push_back( new DeclStmt( tmp ) );
708 if ( InitTweak::isConstructable( tmp->type ) ) {
709 // generate ctor/dtor and resolve them
710 tmp->init = InitTweak::genCtorInit( tmp );
711 tmp->accept( *visitor );
712 }
713 }
714 }
715 }
716
717 void Resolver::previsit( WithStmt * withStmt ) {
718 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
719 }
720
721 template< typename T >
722 bool isCharType( T t ) {
723 if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
724 return bt->get_kind() == BasicType::Char || bt->get_kind() == BasicType::SignedChar ||
725 bt->get_kind() == BasicType::UnsignedChar;
726 }
727 return false;
728 }
729
730 void Resolver::previsit( SingleInit *singleInit ) {
731 visit_children = false;
732 // resolve initialization using the possibilities as determined by the currentObject cursor
733 Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
734 findSingleExpression( newExpr, indexer );
735 InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
736
737 // move cursor to the object that is actually initialized
738 currentObject.setNext( initExpr->get_designation() );
739
740 // discard InitExpr wrapper and retain relevant pieces
741 newExpr = initExpr->expr;
742 initExpr->expr = nullptr;
743 std::swap( initExpr->env, newExpr->env );
744 // InitExpr may have inferParams in the case where the expression specializes a function pointer,
745 // and newExpr may already have inferParams of its own, so a simple swap is not sufficient.
746 newExpr->spliceInferParams( initExpr );
747 delete initExpr;
748
749 // get the actual object's type (may not exactly match what comes back from the resolver due to conversions)
750 Type * initContext = currentObject.getCurrentType();
751
752 removeExtraneousCast( newExpr, indexer );
753
754 // check if actual object's type is char[]
755 if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
756 if ( isCharType( at->get_base() ) ) {
757 // check if the resolved type is char *
758 if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
759 if ( isCharType( pt->get_base() ) ) {
760 if ( CastExpr *ce = dynamic_cast< CastExpr * >( newExpr ) ) {
761 // strip cast if we're initializing a char[] with a char *, e.g. char x[] = "hello";
762 newExpr = ce->get_arg();
763 ce->set_arg( nullptr );
764 std::swap( ce->env, newExpr->env );
765 delete ce;
766 }
767 }
768 }
769 }
770 }
771
772 // set initializer expr to resolved express
773 singleInit->value = newExpr;
774
775 // move cursor to next object in preparation for next initializer
776 currentObject.increment();
777 }
778
779 void Resolver::previsit( ListInit * listInit ) {
780 visit_children = false;
781 // move cursor into brace-enclosed initializer-list
782 currentObject.enterListInit();
783 // xxx - fix this so that the list isn't copied, iterator should be used to change current element
784 std::list<Designation *> newDesignations;
785 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
786 // iterate designations and initializers in pairs, moving the cursor to the current designated object and resolving
787 // the initializer against that object.
788 Designation * des = std::get<0>(p);
789 Initializer * init = std::get<1>(p);
790 newDesignations.push_back( currentObject.findNext( des ) );
791 init->accept( *visitor );
792 }
793 // set the set of 'resolved' designations and leave the brace-enclosed initializer-list
794 listInit->get_designations() = newDesignations; // xxx - memory management
795 currentObject.exitListInit();
796
797 // xxx - this part has not be folded into CurrentObject yet
798 // } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
799 // Type * base = tt->get_baseType()->get_base();
800 // if ( base ) {
801 // // know the implementation type, so try using that as the initContext
802 // ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
803 // currentObject = &tmpObj;
804 // visit( listInit );
805 // } else {
806 // // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
807 // Parent::visit( listInit );
808 // }
809 // } else {
810 }
811
812 // ConstructorInit - fall back on C-style initializer
813 void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
814 // could not find valid constructor, or found an intrinsic constructor
815 // fall back on C-style initializer
816 delete ctorInit->get_ctor();
817 ctorInit->set_ctor( NULL );
818 delete ctorInit->get_dtor();
819 ctorInit->set_dtor( NULL );
820 maybeAccept( ctorInit->get_init(), *visitor );
821 }
822
823 // needs to be callable from outside the resolver, so this is a standalone function
824 void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
825 assert( ctorInit );
826 PassVisitor<Resolver> resolver( indexer );
827 ctorInit->accept( resolver );
828 }
829
830 void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
831 assert( stmtExpr );
832 PassVisitor<Resolver> resolver( indexer );
833 stmtExpr->accept( resolver );
834 stmtExpr->computeResult();
835 // xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
836 }
837
838 void Resolver::previsit( ConstructorInit *ctorInit ) {
839 visit_children = false;
840 // xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
841 maybeAccept( ctorInit->ctor, *visitor );
842 maybeAccept( ctorInit->dtor, *visitor );
843
844 // found a constructor - can get rid of C-style initializer
845 delete ctorInit->init;
846 ctorInit->init = nullptr;
847
848 // intrinsic single parameter constructors and destructors do nothing. Since this was
849 // implicitly generated, there's no way for it to have side effects, so get rid of it
850 // to clean up generated code.
851 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
852 delete ctorInit->ctor;
853 ctorInit->ctor = nullptr;
854 }
855
856 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
857 delete ctorInit->dtor;
858 ctorInit->dtor = nullptr;
859 }
860
861 // xxx - todo -- what about arrays?
862 // if ( dtor == NULL && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
863 // // can reduce the constructor down to a SingleInit using the
864 // // second argument from the ctor call, since
865 // delete ctorInit->get_ctor();
866 // ctorInit->set_ctor( NULL );
867
868 // Expression * arg =
869 // ctorInit->set_init( new SingleInit( arg ) );
870 // }
871 }
872} // namespace ResolvExpr
873
874// Local Variables: //
875// tab-width: 4 //
876// mode: c++ //
877// compile-command: "make install" //
878// End: //
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