source: src/ResolvExpr/Resolver.cc@ 51fcdbc7

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 stuck-waitfor-destruct
Last change on this file since 51fcdbc7 was 51fcdbc7, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Remove lvalue qualifier from objects of typeof type after resolving [fixes #103]
  • Property mode set to 100644
File size: 33.3 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( untyped->location, 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 untyped.location = expr->location;
245
246 // set up and resolve expression cast to void
247 untyped.arg = expr;
248 Alternative choice;
249 findUnfinishedKindExpression( &untyped, choice, indexer, "", standardAlternativeFilter, true );
250 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
251 env = std::move( choice.env );
252
253 // clean up resolved expression
254 Expression * ret = castExpr->arg;
255 castExpr->arg = nullptr;
256
257 // unlink the arg so that it isn't deleted twice at the end of the program
258 untyped.arg = nullptr;
259 return ret;
260 }
261
262 void findVoidExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
263 resetTyVarRenaming();
264 TypeEnvironment env;
265 Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
266 finishExpr( newExpr, env, untyped->env );
267 delete untyped;
268 untyped = newExpr;
269 }
270
271 void findSingleExpression( Expression *&untyped, const SymTab::Indexer &indexer ) {
272 findKindExpression( untyped, indexer, "", standardAlternativeFilter );
273 }
274
275 void findSingleExpression( Expression *& untyped, Type * type, const SymTab::Indexer & indexer ) {
276 assert( untyped && type );
277 // transfer location to generated cast for error purposes
278 CodeLocation location = untyped->location;
279 untyped = new CastExpr( untyped, type );
280 untyped->location = location;
281 findSingleExpression( untyped, indexer );
282 removeExtraneousCast( untyped, indexer );
283 }
284
285 namespace {
286 bool isIntegralType( const Alternative & alt ) {
287 Type * type = alt.expr->result;
288 if ( dynamic_cast< EnumInstType * >( type ) ) {
289 return true;
290 } else if ( BasicType *bt = dynamic_cast< BasicType * >( type ) ) {
291 return bt->isInteger();
292 } else if ( dynamic_cast< ZeroType* >( type ) != nullptr || dynamic_cast< OneType* >( type ) != nullptr ) {
293 return true;
294 } else {
295 return false;
296 } // if
297 }
298
299 void findIntegralExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
300 findKindExpression( untyped, indexer, "condition", isIntegralType );
301 }
302 }
303
304 void Resolver::previsit( ObjectDecl *objectDecl ) {
305 Type *new_type = resolveTypeof( objectDecl->get_type(), indexer );
306 new_type->get_qualifiers() -= Type::Lvalue; // even if typeof is lvalue, variable can never have lvalue-qualified type
307 objectDecl->set_type( new_type );
308 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
309 // initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
310 // initContext because of a function type can contain object declarations in the return and parameter types. So
311 // each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
312 // the RHS.
313 GuardValue( currentObject );
314 currentObject = CurrentObject( objectDecl->get_type() );
315 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
316 // enumerator initializers should not use the enum type to initialize, since
317 // the enum type is still incomplete at this point. Use signed int instead.
318 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
319 }
320 }
321
322 template< typename PtrType >
323 void Resolver::handlePtrType( PtrType * type ) {
324 if ( type->get_dimension() ) {
325 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
326 }
327 }
328
329 void Resolver::previsit( ArrayType * at ) {
330 handlePtrType( at );
331 }
332
333 void Resolver::previsit( PointerType * pt ) {
334 handlePtrType( pt );
335 }
336
337 void Resolver::previsit( TypeDecl *typeDecl ) {
338 if ( typeDecl->get_base() ) {
339 Type *new_type = resolveTypeof( typeDecl->get_base(), indexer );
340 typeDecl->set_base( new_type );
341 } // if
342 }
343
344 void Resolver::previsit( FunctionDecl *functionDecl ) {
345#if 0
346 std::cerr << "resolver visiting functiondecl ";
347 functionDecl->print( std::cerr );
348 std::cerr << std::endl;
349#endif
350 Type *new_type = resolveTypeof( functionDecl->type, indexer );
351 functionDecl->set_type( new_type );
352 GuardValue( functionReturn );
353 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
354
355 {
356 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
357 // front of the function body.
358 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
359 indexer.addFunctionType( functionDecl->type );
360 std::list< Statement * > newStmts;
361 resolveWithExprs( functionDecl->withExprs, newStmts );
362 if ( functionDecl->statements ) {
363 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
364 } else {
365 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
366 }
367 }
368 }
369
370 void Resolver::postvisit( FunctionDecl *functionDecl ) {
371 // default value expressions have an environment which shouldn't be there and trips up later passes.
372 // xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
373 // see how it's useful.
374 for ( Declaration * d : functionDecl->type->parameters ) {
375 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
376 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
377 delete init->value->env;
378 init->value->env = nullptr;
379 }
380 }
381 }
382 }
383
384 void Resolver::previsit( EnumDecl * ) {
385 // in case we decide to allow nested enums
386 GuardValue( inEnumDecl );
387 inEnumDecl = true;
388 }
389
390 void Resolver::previsit( StaticAssertDecl * assertDecl ) {
391 findIntegralExpression( assertDecl->condition, indexer );
392 }
393
394 void Resolver::previsit( ExprStmt *exprStmt ) {
395 visit_children = false;
396 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
397 findVoidExpression( exprStmt->expr, indexer );
398 }
399
400 void Resolver::previsit( AsmExpr *asmExpr ) {
401 visit_children = false;
402 findVoidExpression( asmExpr->operand, indexer );
403 if ( asmExpr->get_inout() ) {
404 findVoidExpression( asmExpr->inout, indexer );
405 } // if
406 }
407
408 void Resolver::previsit( AsmStmt *asmStmt ) {
409 visit_children = false;
410 acceptAll( asmStmt->get_input(), *visitor );
411 acceptAll( asmStmt->get_output(), *visitor );
412 }
413
414 void Resolver::previsit( IfStmt *ifStmt ) {
415 findIntegralExpression( ifStmt->condition, indexer );
416 }
417
418 void Resolver::previsit( WhileStmt *whileStmt ) {
419 findIntegralExpression( whileStmt->condition, indexer );
420 }
421
422 void Resolver::previsit( ForStmt *forStmt ) {
423 if ( forStmt->condition ) {
424 findIntegralExpression( forStmt->condition, indexer );
425 } // if
426
427 if ( forStmt->increment ) {
428 findVoidExpression( forStmt->increment, indexer );
429 } // if
430 }
431
432 void Resolver::previsit( SwitchStmt *switchStmt ) {
433 GuardValue( currentObject );
434 findIntegralExpression( switchStmt->condition, indexer );
435
436 currentObject = CurrentObject( switchStmt->condition->result );
437 }
438
439 void Resolver::previsit( CaseStmt *caseStmt ) {
440 if ( caseStmt->condition ) {
441 std::list< InitAlternative > initAlts = currentObject.getOptions();
442 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
443 // must remove cast from case statement because RangeExpr cannot be cast.
444 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
445 findSingleExpression( newExpr, indexer );
446 // case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
447 // Ideally we would perform the conversion internally here.
448 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
449 newExpr = castExpr->arg;
450 castExpr->arg = nullptr;
451 std::swap( newExpr->env, castExpr->env );
452 delete castExpr;
453 }
454 caseStmt->condition = newExpr;
455 }
456 }
457
458 void Resolver::previsit( BranchStmt *branchStmt ) {
459 visit_children = false;
460 // must resolve the argument for a computed goto
461 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
462 if ( branchStmt->computedTarget ) {
463 // computed goto argument is void *
464 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
465 } // if
466 } // if
467 }
468
469 void Resolver::previsit( ReturnStmt *returnStmt ) {
470 visit_children = false;
471 if ( returnStmt->expr ) {
472 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
473 } // if
474 }
475
476 void Resolver::previsit( ThrowStmt *throwStmt ) {
477 visit_children = false;
478 // TODO: Replace *exception type with &exception type.
479 if ( throwStmt->get_expr() ) {
480 StructDecl * exception_decl =
481 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
482 assert( exception_decl );
483 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
484 findSingleExpression( throwStmt->expr, exceptType, indexer );
485 }
486 }
487
488 void Resolver::previsit( CatchStmt *catchStmt ) {
489 if ( catchStmt->cond ) {
490 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
491 }
492 }
493
494 template< typename iterator_t >
495 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
496 while( it != end && !(*it)->get_type()->get_mutex() ) {
497 it++;
498 }
499
500 return it != end;
501 }
502
503 void Resolver::previsit( WaitForStmt * stmt ) {
504 visit_children = false;
505
506 // Resolve all clauses first
507 for( auto& clause : stmt->clauses ) {
508
509 TypeEnvironment env;
510 AlternativeFinder funcFinder( indexer, env );
511
512 // Find all alternatives for a function in canonical form
513 funcFinder.findWithAdjustment( clause.target.function );
514
515 if ( funcFinder.get_alternatives().empty() ) {
516 stringstream ss;
517 ss << "Use of undeclared indentifier '";
518 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
519 ss << "' in call to waitfor";
520 SemanticError( stmt->location, ss.str() );
521 }
522
523 if(clause.target.arguments.empty()) {
524 SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
525 }
526
527 // Find all alternatives for all arguments in canonical form
528 std::vector< AlternativeFinder > argAlternatives;
529 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
530
531 // List all combinations of arguments
532 std::vector< AltList > possibilities;
533 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
534
535 AltList func_candidates;
536 std::vector< AltList > args_candidates;
537
538 // For every possible function :
539 // try matching the arguments to the parameters
540 // not the other way around because we have more arguments than parameters
541 SemanticErrorException errors;
542 for ( Alternative & func : funcFinder.get_alternatives() ) {
543 try {
544 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
545 if( !pointer ) {
546 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
547 }
548
549 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
550 if( !function ) {
551 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
552 }
553
554
555 {
556 auto param = function->parameters.begin();
557 auto param_end = function->parameters.end();
558
559 if( !advance_to_mutex( param, param_end ) ) {
560 SemanticError(function, "candidate function not viable: no mutex parameters\n");
561 }
562 }
563
564 Alternative newFunc( func );
565 // Strip reference from function
566 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
567
568 // For all the set of arguments we have try to match it with the parameter of the current function alternative
569 for ( auto & argsList : possibilities ) {
570
571 try {
572 // Declare data structures need for resolution
573 OpenVarSet openVars;
574 AssertionSet resultNeed, resultHave;
575 TypeEnvironment resultEnv( func.env );
576 makeUnifiableVars( function, openVars, resultNeed );
577 // add all type variables as open variables now so that those not used in the parameter
578 // list are still considered open.
579 resultEnv.add( function->forall );
580
581 // Load type variables from arguemnts into one shared space
582 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
583
584 // Make sure we don't widen any existing bindings
585 resultEnv.forbidWidening();
586
587 // Find any unbound type variables
588 resultEnv.extractOpenVars( openVars );
589
590 auto param = function->parameters.begin();
591 auto param_end = function->parameters.end();
592
593 int n_mutex_param = 0;
594
595 // For every arguments of its set, check if it matches one of the parameter
596 // The order is important
597 for( auto & arg : argsList ) {
598
599 // Ignore non-mutex arguments
600 if( !advance_to_mutex( param, param_end ) ) {
601 // We ran out of parameters but still have arguments
602 // this function doesn't match
603 SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_param, "\n" ));
604 }
605
606 n_mutex_param++;
607
608 // Check if the argument matches the parameter type in the current scope
609 if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
610 // Type doesn't match
611 stringstream ss;
612 ss << "candidate function not viable: no known convertion from '";
613 (*param)->get_type()->print( ss );
614 ss << "' to '";
615 arg.expr->get_result()->print( ss );
616 ss << "' with env '";
617 resultEnv.print(ss);
618 ss << "'\n";
619 SemanticError( function, ss.str() );
620 }
621
622 param++;
623 }
624
625 // All arguments match !
626
627 // Check if parameters are missing
628 if( advance_to_mutex( param, param_end ) ) {
629 do {
630 n_mutex_param++;
631 param++;
632 } while( advance_to_mutex( param, param_end ) );
633
634 // We ran out of arguments but still have parameters left
635 // this function doesn't match
636 SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_param, "\n" ));
637 }
638
639 // All parameters match !
640
641 // Finish the expressions to tie in the proper environments
642 finishExpr( newFunc.expr, resultEnv );
643 for( Alternative & alt : argsList ) {
644 finishExpr( alt.expr, resultEnv );
645 }
646
647 // This is a match store it and save it for later
648 func_candidates.push_back( newFunc );
649 args_candidates.push_back( argsList );
650
651 }
652 catch( SemanticErrorException &e ) {
653 errors.append( e );
654 }
655 }
656 }
657 catch( SemanticErrorException &e ) {
658 errors.append( e );
659 }
660 }
661
662 // Make sure we got the right number of arguments
663 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
664 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
665 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
666 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
667 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
668
669 // Swap the results from the alternative with the unresolved values.
670 // Alternatives will handle deletion on destruction
671 std::swap( clause.target.function, func_candidates.front().expr );
672 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
673 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
674 }
675
676 // Resolve the conditions as if it were an IfStmt
677 // Resolve the statments normally
678 findSingleExpression( clause.condition, this->indexer );
679 clause.statement->accept( *visitor );
680 }
681
682
683 if( stmt->timeout.statement ) {
684 // Resolve the timeout as an size_t for now
685 // Resolve the conditions as if it were an IfStmt
686 // Resolve the statments normally
687 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
688 findSingleExpression( stmt->timeout.condition, this->indexer );
689 stmt->timeout.statement->accept( *visitor );
690 }
691
692 if( stmt->orelse.statement ) {
693 // Resolve the conditions as if it were an IfStmt
694 // Resolve the statments normally
695 findSingleExpression( stmt->orelse.condition, this->indexer );
696 stmt->orelse.statement->accept( *visitor );
697 }
698 }
699
700 bool isStructOrUnion( const Alternative & alt ) {
701 Type * t = alt.expr->result->stripReferences();
702 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
703 }
704
705 void Resolver::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
706 for ( Expression *& expr : withExprs ) {
707 // only struct- and union-typed expressions are viable candidates
708 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
709
710 // if with expression might be impure, create a temporary so that it is evaluated once
711 if ( Tuples::maybeImpure( expr ) ) {
712 static UniqueName tmpNamer( "_with_tmp_" );
713 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
714 expr = new VariableExpr( tmp );
715 newStmts.push_back( new DeclStmt( tmp ) );
716 if ( InitTweak::isConstructable( tmp->type ) ) {
717 // generate ctor/dtor and resolve them
718 tmp->init = InitTweak::genCtorInit( tmp );
719 tmp->accept( *visitor );
720 }
721 }
722 }
723 }
724
725 void Resolver::previsit( WithStmt * withStmt ) {
726 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
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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