source: src/ResolvExpr/Resolver.cc@ 59cf83b

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr no_list persistent-indexer pthread-emulation qualifiedEnum
Last change on this file since 59cf83b was 59cf83b, checked in by Aaron Moss <a3moss@…>, 7 years ago

Switch resolution flags to packed struct
  • Property mode set to 100644
File size: 33.1 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 : Aaron B. Moss
12// Last Modified On : Fri Oct 05 09:43:00 2018
13// Update Count : 214
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 "Resolver.h"
33#include "ResolvMode.h" // for ResolvMode
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( EnumDecl * enumDecl );
60 void previsit( StaticAssertDecl * assertDecl );
61
62 void previsit( ArrayType * at );
63 void previsit( PointerType * at );
64
65 void previsit( ExprStmt *exprStmt );
66 void previsit( AsmExpr *asmExpr );
67 void previsit( AsmStmt *asmStmt );
68 void previsit( IfStmt *ifStmt );
69 void previsit( WhileStmt *whileStmt );
70 void previsit( ForStmt *forStmt );
71 void previsit( SwitchStmt *switchStmt );
72 void previsit( CaseStmt *caseStmt );
73 void previsit( BranchStmt *branchStmt );
74 void previsit( ReturnStmt *returnStmt );
75 void previsit( ThrowStmt *throwStmt );
76 void previsit( CatchStmt *catchStmt );
77 void previsit( WaitForStmt * stmt );
78
79 void previsit( SingleInit *singleInit );
80 void previsit( ListInit *listInit );
81 void previsit( ConstructorInit *ctorInit );
82 private:
83 typedef std::list< Initializer * >::iterator InitIterator;
84
85 template< typename PtrType >
86 void handlePtrType( PtrType * type );
87
88 void fallbackInit( ConstructorInit * ctorInit );
89
90 Type * functionReturn = nullptr;
91 CurrentObject currentObject = nullptr;
92 bool inEnumDecl = false;
93 };
94
95 struct ResolveWithExprs : public WithIndexer, public WithGuards, public WithVisitorRef<ResolveWithExprs>, public WithShortCircuiting, public WithStmtsToAdd {
96 void previsit( FunctionDecl * );
97 void previsit( WithStmt * );
98
99 void resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts );
100 };
101
102 void resolve( std::list< Declaration * > translationUnit ) {
103 PassVisitor<Resolver> resolver;
104 acceptAll( translationUnit, resolver );
105 }
106
107 void resolveDecl( Declaration * decl, const SymTab::Indexer &indexer ) {
108 PassVisitor<Resolver> resolver( indexer );
109 maybeAccept( decl, resolver );
110 }
111
112 namespace {
113 struct DeleteFinder : public WithShortCircuiting {
114 DeletedExpr * delExpr = nullptr;
115 void previsit( DeletedExpr * expr ) {
116 if ( delExpr ) visit_children = false;
117 else delExpr = expr;
118 }
119
120 void previsit( Expression * ) {
121 if ( delExpr ) visit_children = false;
122 }
123 };
124 }
125
126 DeletedExpr * findDeletedExpr( Expression * expr ) {
127 PassVisitor<DeleteFinder> finder;
128 expr->accept( finder );
129 return finder.pass.delExpr;
130 }
131
132 namespace {
133 struct StripCasts {
134 Expression * postmutate( CastExpr * castExpr ) {
135 if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
136 // generated cast is to the same type as its argument, so it's unnecessary -- remove it
137 Expression * expr = castExpr->arg;
138 castExpr->arg = nullptr;
139 std::swap( expr->env, castExpr->env );
140 return expr;
141 }
142 return castExpr;
143 }
144
145 static void strip( Expression *& expr ) {
146 PassVisitor<StripCasts> stripper;
147 expr = expr->acceptMutator( stripper );
148 }
149 };
150
151 void finishExpr( Expression *&expr, const TypeEnvironment &env, TypeSubstitution * oldenv = nullptr ) {
152 expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
153 env.makeSubstitution( *expr->env );
154 StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
155 }
156
157 void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
158 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
159 if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
160 // cast is to the same type as its argument, so it's unnecessary -- remove it
161 expr = castExpr->arg;
162 castExpr->arg = nullptr;
163 std::swap( expr->env, castExpr->env );
164 delete castExpr;
165 }
166 }
167 }
168 } // namespace
169
170 namespace {
171 void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{} ) {
172 assertf( untyped, "expected a non-null expression." );
173 TypeEnvironment env;
174 AlternativeFinder finder( indexer, env );
175 finder.find( untyped, mode );
176
177 #if 0
178 if ( finder.get_alternatives().size() != 1 ) {
179 std::cerr << "untyped expr is ";
180 untyped->print( std::cerr );
181 std::cerr << std::endl << "alternatives are:";
182 for ( const Alternative & alt : finder.get_alternatives() ) {
183 alt.print( std::cerr );
184 } // for
185 } // if
186 #endif
187
188 AltList candidates;
189 for ( Alternative & alt : finder.get_alternatives() ) {
190 if ( pred( alt ) ) {
191 candidates.push_back( std::move( alt ) );
192 }
193 }
194
195 // xxx - if > 1 alternative with same cost, ignore deleted and pick from remaining
196 // choose the lowest cost expression among the candidates
197 AltList winners;
198 findMinCost( candidates.begin(), candidates.end(), back_inserter( winners ) );
199 if ( winners.size() == 0 ) {
200 SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
201 } else if ( winners.size() != 1 ) {
202 std::ostringstream stream;
203 stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
204 untyped->print( stream );
205 stream << " Alternatives are:\n";
206 printAlts( winners, stream, 1 );
207 SemanticError( untyped->location, stream.str() );
208 }
209
210 // there is one unambiguous interpretation - move the expression into the with statement
211 Alternative & choice = winners.front();
212 if ( findDeletedExpr( choice.expr ) ) {
213 SemanticError( untyped->location, choice.expr, "Unique best alternative includes deleted identifier in " );
214 }
215 alt = std::move( choice );
216 }
217
218 /// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
219 void findKindExpression(Expression *& untyped, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, ResolvMode mode = ResolvMode{}) {
220 if ( ! untyped ) return;
221 Alternative choice;
222 findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, mode );
223 finishExpr( choice.expr, choice.env, untyped->env );
224 delete untyped;
225 untyped = choice.expr;
226 choice.expr = nullptr;
227 }
228
229 bool standardAlternativeFilter( const Alternative & ) {
230 // currently don't need to filter, under normal circumstances.
231 // in the future, this may be useful for removing deleted expressions
232 return true;
233 }
234 } // namespace
235
236 // used in resolveTypeof
237 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer ) {
238 TypeEnvironment env;
239 return resolveInVoidContext( expr, indexer, env );
240 }
241
242 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
243 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
244 // interpretations, an exception has already been thrown.
245 assertf( expr, "expected a non-null expression." );
246
247 static CastExpr untyped( nullptr ); // cast to void
248 untyped.location = expr->location;
249
250 // set up and resolve expression cast to void
251 untyped.arg = expr;
252 Alternative choice;
253 findUnfinishedKindExpression( &untyped, choice, indexer, "", standardAlternativeFilter, ResolvMode::withAdjustment() );
254 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
255 env = std::move( choice.env );
256
257 // clean up resolved expression
258 Expression * ret = castExpr->arg;
259 castExpr->arg = nullptr;
260
261 // unlink the arg so that it isn't deleted twice at the end of the program
262 untyped.arg = nullptr;
263 return ret;
264 }
265
266 void findVoidExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
267 resetTyVarRenaming();
268 TypeEnvironment env;
269 Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
270 finishExpr( newExpr, env, untyped->env );
271 delete untyped;
272 untyped = newExpr;
273 }
274
275 void findSingleExpression( Expression *&untyped, const SymTab::Indexer &indexer ) {
276 findKindExpression( untyped, indexer, "", standardAlternativeFilter );
277 }
278
279 void findSingleExpression( Expression *& untyped, Type * type, const SymTab::Indexer & indexer ) {
280 assert( untyped && type );
281 // transfer location to generated cast for error purposes
282 CodeLocation location = untyped->location;
283 untyped = new CastExpr( untyped, type );
284 untyped->location = location;
285 findSingleExpression( untyped, indexer );
286 removeExtraneousCast( untyped, indexer );
287 }
288
289 namespace {
290 bool isIntegralType( const Alternative & alt ) {
291 Type * type = alt.expr->result;
292 if ( dynamic_cast< EnumInstType * >( type ) ) {
293 return true;
294 } else if ( BasicType *bt = dynamic_cast< BasicType * >( type ) ) {
295 return bt->isInteger();
296 } else if ( dynamic_cast< ZeroType* >( type ) != nullptr || dynamic_cast< OneType* >( type ) != nullptr ) {
297 return true;
298 } else {
299 return false;
300 } // if
301 }
302
303 void findIntegralExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
304 findKindExpression( untyped, indexer, "condition", isIntegralType );
305 }
306 }
307
308
309 bool isStructOrUnion( const Alternative & alt ) {
310 Type * t = alt.expr->result->stripReferences();
311 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
312 }
313
314 void resolveWithExprs( std::list< Declaration * > & translationUnit ) {
315 PassVisitor<ResolveWithExprs> resolver;
316 acceptAll( translationUnit, resolver );
317 }
318
319 void ResolveWithExprs::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
320 for ( Expression *& expr : withExprs ) {
321 // only struct- and union-typed expressions are viable candidates
322 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
323
324 // if with expression might be impure, create a temporary so that it is evaluated once
325 if ( Tuples::maybeImpure( expr ) ) {
326 static UniqueName tmpNamer( "_with_tmp_" );
327 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
328 expr = new VariableExpr( tmp );
329 newStmts.push_back( new DeclStmt( tmp ) );
330 if ( InitTweak::isConstructable( tmp->type ) ) {
331 // generate ctor/dtor and resolve them
332 tmp->init = InitTweak::genCtorInit( tmp );
333 tmp->accept( *visitor );
334 }
335 }
336 }
337 }
338
339 void ResolveWithExprs::previsit( WithStmt * withStmt ) {
340 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
341 }
342
343 void ResolveWithExprs::previsit( FunctionDecl * functionDecl ) {
344 {
345 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
346 // front of the function body.
347 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
348 indexer.addFunctionType( functionDecl->type );
349 std::list< Statement * > newStmts;
350 resolveWithExprs( functionDecl->withExprs, newStmts );
351 if ( functionDecl->statements ) {
352 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
353 } else {
354 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
355 }
356 }
357 }
358
359 void Resolver::previsit( ObjectDecl *objectDecl ) {
360 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
361 // initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
362 // initContext because of a function type can contain object declarations in the return and parameter types. So
363 // each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
364 // the RHS.
365 GuardValue( currentObject );
366 currentObject = CurrentObject( objectDecl->get_type() );
367 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
368 // enumerator initializers should not use the enum type to initialize, since
369 // the enum type is still incomplete at this point. Use signed int instead.
370 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
371 }
372 }
373
374 template< typename PtrType >
375 void Resolver::handlePtrType( PtrType * type ) {
376 if ( type->get_dimension() ) {
377 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
378 }
379 }
380
381 void Resolver::previsit( ArrayType * at ) {
382 handlePtrType( at );
383 }
384
385 void Resolver::previsit( PointerType * pt ) {
386 handlePtrType( pt );
387 }
388
389 void Resolver::previsit( FunctionDecl *functionDecl ) {
390#if 0
391 std::cerr << "resolver visiting functiondecl ";
392 functionDecl->print( std::cerr );
393 std::cerr << std::endl;
394#endif
395 GuardValue( functionReturn );
396 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
397 }
398
399 void Resolver::postvisit( FunctionDecl *functionDecl ) {
400 // default value expressions have an environment which shouldn't be there and trips up later passes.
401 // xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
402 // see how it's useful.
403 for ( Declaration * d : functionDecl->type->parameters ) {
404 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
405 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
406 delete init->value->env;
407 init->value->env = nullptr;
408 }
409 }
410 }
411 }
412
413 void Resolver::previsit( EnumDecl * ) {
414 // in case we decide to allow nested enums
415 GuardValue( inEnumDecl );
416 inEnumDecl = true;
417 }
418
419 void Resolver::previsit( StaticAssertDecl * assertDecl ) {
420 findIntegralExpression( assertDecl->condition, indexer );
421 }
422
423 void Resolver::previsit( ExprStmt *exprStmt ) {
424 visit_children = false;
425 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
426 findVoidExpression( exprStmt->expr, indexer );
427 }
428
429 void Resolver::previsit( AsmExpr *asmExpr ) {
430 visit_children = false;
431 findVoidExpression( asmExpr->operand, indexer );
432 if ( asmExpr->get_inout() ) {
433 findVoidExpression( asmExpr->inout, indexer );
434 } // if
435 }
436
437 void Resolver::previsit( AsmStmt *asmStmt ) {
438 visit_children = false;
439 acceptAll( asmStmt->get_input(), *visitor );
440 acceptAll( asmStmt->get_output(), *visitor );
441 }
442
443 void Resolver::previsit( IfStmt *ifStmt ) {
444 findIntegralExpression( ifStmt->condition, indexer );
445 }
446
447 void Resolver::previsit( WhileStmt *whileStmt ) {
448 findIntegralExpression( whileStmt->condition, indexer );
449 }
450
451 void Resolver::previsit( ForStmt *forStmt ) {
452 if ( forStmt->condition ) {
453 findIntegralExpression( forStmt->condition, indexer );
454 } // if
455
456 if ( forStmt->increment ) {
457 findVoidExpression( forStmt->increment, indexer );
458 } // if
459 }
460
461 void Resolver::previsit( SwitchStmt *switchStmt ) {
462 GuardValue( currentObject );
463 findIntegralExpression( switchStmt->condition, indexer );
464
465 currentObject = CurrentObject( switchStmt->condition->result );
466 }
467
468 void Resolver::previsit( CaseStmt *caseStmt ) {
469 if ( caseStmt->condition ) {
470 std::list< InitAlternative > initAlts = currentObject.getOptions();
471 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
472 // must remove cast from case statement because RangeExpr cannot be cast.
473 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
474 findSingleExpression( newExpr, indexer );
475 // case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
476 // Ideally we would perform the conversion internally here.
477 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
478 newExpr = castExpr->arg;
479 castExpr->arg = nullptr;
480 std::swap( newExpr->env, castExpr->env );
481 delete castExpr;
482 }
483 caseStmt->condition = newExpr;
484 }
485 }
486
487 void Resolver::previsit( BranchStmt *branchStmt ) {
488 visit_children = false;
489 // must resolve the argument for a computed goto
490 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
491 if ( branchStmt->computedTarget ) {
492 // computed goto argument is void *
493 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
494 } // if
495 } // if
496 }
497
498 void Resolver::previsit( ReturnStmt *returnStmt ) {
499 visit_children = false;
500 if ( returnStmt->expr ) {
501 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
502 } // if
503 }
504
505 void Resolver::previsit( ThrowStmt *throwStmt ) {
506 visit_children = false;
507 // TODO: Replace *exception type with &exception type.
508 if ( throwStmt->get_expr() ) {
509 StructDecl * exception_decl =
510 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
511 assert( exception_decl );
512 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
513 findSingleExpression( throwStmt->expr, exceptType, indexer );
514 }
515 }
516
517 void Resolver::previsit( CatchStmt *catchStmt ) {
518 if ( catchStmt->cond ) {
519 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
520 }
521 }
522
523 template< typename iterator_t >
524 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
525 while( it != end && !(*it)->get_type()->get_mutex() ) {
526 it++;
527 }
528
529 return it != end;
530 }
531
532 void Resolver::previsit( WaitForStmt * stmt ) {
533 visit_children = false;
534
535 // Resolve all clauses first
536 for( auto& clause : stmt->clauses ) {
537
538 TypeEnvironment env;
539 AlternativeFinder funcFinder( indexer, env );
540
541 // Find all alternatives for a function in canonical form
542 funcFinder.findWithAdjustment( clause.target.function );
543
544 if ( funcFinder.get_alternatives().empty() ) {
545 stringstream ss;
546 ss << "Use of undeclared indentifier '";
547 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
548 ss << "' in call to waitfor";
549 SemanticError( stmt->location, ss.str() );
550 }
551
552 if(clause.target.arguments.empty()) {
553 SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
554 }
555
556 // Find all alternatives for all arguments in canonical form
557 std::vector< AlternativeFinder > argAlternatives;
558 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
559
560 // List all combinations of arguments
561 std::vector< AltList > possibilities;
562 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
563
564 AltList func_candidates;
565 std::vector< AltList > args_candidates;
566
567 // For every possible function :
568 // try matching the arguments to the parameters
569 // not the other way around because we have more arguments than parameters
570 SemanticErrorException errors;
571 for ( Alternative & func : funcFinder.get_alternatives() ) {
572 try {
573 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
574 if( !pointer ) {
575 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
576 }
577
578 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
579 if( !function ) {
580 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
581 }
582
583
584 {
585 auto param = function->parameters.begin();
586 auto param_end = function->parameters.end();
587
588 if( !advance_to_mutex( param, param_end ) ) {
589 SemanticError(function, "candidate function not viable: no mutex parameters\n");
590 }
591 }
592
593 Alternative newFunc( func );
594 // Strip reference from function
595 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
596
597 // For all the set of arguments we have try to match it with the parameter of the current function alternative
598 for ( auto & argsList : possibilities ) {
599
600 try {
601 // Declare data structures need for resolution
602 OpenVarSet openVars;
603 AssertionSet resultNeed, resultHave;
604 TypeEnvironment resultEnv( func.env );
605 makeUnifiableVars( function, openVars, resultNeed );
606 // add all type variables as open variables now so that those not used in the parameter
607 // list are still considered open.
608 resultEnv.add( function->forall );
609
610 // Load type variables from arguemnts into one shared space
611 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
612
613 // Make sure we don't widen any existing bindings
614 resultEnv.forbidWidening();
615
616 // Find any unbound type variables
617 resultEnv.extractOpenVars( openVars );
618
619 auto param = function->parameters.begin();
620 auto param_end = function->parameters.end();
621
622 int n_mutex_param = 0;
623
624 // For every arguments of its set, check if it matches one of the parameter
625 // The order is important
626 for( auto & arg : argsList ) {
627
628 // Ignore non-mutex arguments
629 if( !advance_to_mutex( param, param_end ) ) {
630 // We ran out of parameters but still have arguments
631 // this function doesn't match
632 SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_param, "\n" ));
633 }
634
635 n_mutex_param++;
636
637 // Check if the argument matches the parameter type in the current scope
638 if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
639 // Type doesn't match
640 stringstream ss;
641 ss << "candidate function not viable: no known convertion from '";
642 (*param)->get_type()->print( ss );
643 ss << "' to '";
644 arg.expr->get_result()->print( ss );
645 ss << "' with env '";
646 resultEnv.print(ss);
647 ss << "'\n";
648 SemanticError( function, ss.str() );
649 }
650
651 param++;
652 }
653
654 // All arguments match !
655
656 // Check if parameters are missing
657 if( advance_to_mutex( param, param_end ) ) {
658 do {
659 n_mutex_param++;
660 param++;
661 } while( advance_to_mutex( param, param_end ) );
662
663 // We ran out of arguments but still have parameters left
664 // this function doesn't match
665 SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_param, "\n" ));
666 }
667
668 // All parameters match !
669
670 // Finish the expressions to tie in the proper environments
671 finishExpr( newFunc.expr, resultEnv );
672 for( Alternative & alt : argsList ) {
673 finishExpr( alt.expr, resultEnv );
674 }
675
676 // This is a match store it and save it for later
677 func_candidates.push_back( newFunc );
678 args_candidates.push_back( argsList );
679
680 }
681 catch( SemanticErrorException &e ) {
682 errors.append( e );
683 }
684 }
685 }
686 catch( SemanticErrorException &e ) {
687 errors.append( e );
688 }
689 }
690
691 // Make sure we got the right number of arguments
692 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
693 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
694 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
695 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
696 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
697
698 // Swap the results from the alternative with the unresolved values.
699 // Alternatives will handle deletion on destruction
700 std::swap( clause.target.function, func_candidates.front().expr );
701 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
702 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
703 }
704
705 // Resolve the conditions as if it were an IfStmt
706 // Resolve the statments normally
707 findSingleExpression( clause.condition, this->indexer );
708 clause.statement->accept( *visitor );
709 }
710
711
712 if( stmt->timeout.statement ) {
713 // Resolve the timeout as an size_t for now
714 // Resolve the conditions as if it were an IfStmt
715 // Resolve the statments normally
716 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
717 findSingleExpression( stmt->timeout.condition, this->indexer );
718 stmt->timeout.statement->accept( *visitor );
719 }
720
721 if( stmt->orelse.statement ) {
722 // Resolve the conditions as if it were an IfStmt
723 // Resolve the statments normally
724 findSingleExpression( stmt->orelse.condition, this->indexer );
725 stmt->orelse.statement->accept( *visitor );
726 }
727 }
728
729 template< typename T >
730 bool isCharType( T t ) {
731 if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
732 return bt->get_kind() == BasicType::Char || bt->get_kind() == BasicType::SignedChar ||
733 bt->get_kind() == BasicType::UnsignedChar;
734 }
735 return false;
736 }
737
738 void Resolver::previsit( SingleInit *singleInit ) {
739 visit_children = false;
740 // resolve initialization using the possibilities as determined by the currentObject cursor
741 Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
742 findSingleExpression( newExpr, indexer );
743 InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
744
745 // move cursor to the object that is actually initialized
746 currentObject.setNext( initExpr->get_designation() );
747
748 // discard InitExpr wrapper and retain relevant pieces
749 newExpr = initExpr->expr;
750 initExpr->expr = nullptr;
751 std::swap( initExpr->env, newExpr->env );
752 // InitExpr may have inferParams in the case where the expression specializes a function pointer,
753 // and newExpr may already have inferParams of its own, so a simple swap is not sufficient.
754 newExpr->spliceInferParams( initExpr );
755 delete initExpr;
756
757 // get the actual object's type (may not exactly match what comes back from the resolver due to conversions)
758 Type * initContext = currentObject.getCurrentType();
759
760 removeExtraneousCast( newExpr, indexer );
761
762 // check if actual object's type is char[]
763 if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
764 if ( isCharType( at->get_base() ) ) {
765 // check if the resolved type is char *
766 if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
767 if ( isCharType( pt->get_base() ) ) {
768 if ( CastExpr *ce = dynamic_cast< CastExpr * >( newExpr ) ) {
769 // strip cast if we're initializing a char[] with a char *, e.g. char x[] = "hello";
770 newExpr = ce->get_arg();
771 ce->set_arg( nullptr );
772 std::swap( ce->env, newExpr->env );
773 delete ce;
774 }
775 }
776 }
777 }
778 }
779
780 // set initializer expr to resolved express
781 singleInit->value = newExpr;
782
783 // move cursor to next object in preparation for next initializer
784 currentObject.increment();
785 }
786
787 void Resolver::previsit( ListInit * listInit ) {
788 visit_children = false;
789 // move cursor into brace-enclosed initializer-list
790 currentObject.enterListInit();
791 // xxx - fix this so that the list isn't copied, iterator should be used to change current element
792 std::list<Designation *> newDesignations;
793 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
794 // iterate designations and initializers in pairs, moving the cursor to the current designated object and resolving
795 // the initializer against that object.
796 Designation * des = std::get<0>(p);
797 Initializer * init = std::get<1>(p);
798 newDesignations.push_back( currentObject.findNext( des ) );
799 init->accept( *visitor );
800 }
801 // set the set of 'resolved' designations and leave the brace-enclosed initializer-list
802 listInit->get_designations() = newDesignations; // xxx - memory management
803 currentObject.exitListInit();
804
805 // xxx - this part has not be folded into CurrentObject yet
806 // } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
807 // Type * base = tt->get_baseType()->get_base();
808 // if ( base ) {
809 // // know the implementation type, so try using that as the initContext
810 // ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
811 // currentObject = &tmpObj;
812 // visit( listInit );
813 // } else {
814 // // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
815 // Parent::visit( listInit );
816 // }
817 // } else {
818 }
819
820 // ConstructorInit - fall back on C-style initializer
821 void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
822 // could not find valid constructor, or found an intrinsic constructor
823 // fall back on C-style initializer
824 delete ctorInit->get_ctor();
825 ctorInit->set_ctor( NULL );
826 delete ctorInit->get_dtor();
827 ctorInit->set_dtor( NULL );
828 maybeAccept( ctorInit->get_init(), *visitor );
829 }
830
831 // needs to be callable from outside the resolver, so this is a standalone function
832 void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
833 assert( ctorInit );
834 PassVisitor<Resolver> resolver( indexer );
835 ctorInit->accept( resolver );
836 }
837
838 void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
839 assert( stmtExpr );
840 PassVisitor<Resolver> resolver( indexer );
841 stmtExpr->accept( resolver );
842 stmtExpr->computeResult();
843 // xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
844 }
845
846 void Resolver::previsit( ConstructorInit *ctorInit ) {
847 visit_children = false;
848 // xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
849 maybeAccept( ctorInit->ctor, *visitor );
850 maybeAccept( ctorInit->dtor, *visitor );
851
852 // found a constructor - can get rid of C-style initializer
853 delete ctorInit->init;
854 ctorInit->init = nullptr;
855
856 // intrinsic single parameter constructors and destructors do nothing. Since this was
857 // implicitly generated, there's no way for it to have side effects, so get rid of it
858 // to clean up generated code.
859 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
860 delete ctorInit->ctor;
861 ctorInit->ctor = nullptr;
862 }
863
864 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
865 delete ctorInit->dtor;
866 ctorInit->dtor = nullptr;
867 }
868
869 // xxx - todo -- what about arrays?
870 // if ( dtor == NULL && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
871 // // can reduce the constructor down to a SingleInit using the
872 // // second argument from the ctor call, since
873 // delete ctorInit->get_ctor();
874 // ctorInit->set_ctor( NULL );
875
876 // Expression * arg =
877 // ctorInit->set_init( new SingleInit( arg ) );
878 // }
879 }
880} // namespace ResolvExpr
881
882// Local Variables: //
883// tab-width: 4 //
884// mode: c++ //
885// compile-command: "make install" //
886// End: //
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