source: src/ResolvExpr/Resolver.cc@ d286cf68

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 d286cf68 was d286cf68, checked in by Aaron Moss <a3moss@…>, 7 years ago

Fix TypeEnvironment bind algorithms
  • 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 : 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 objectDecl->set_type( new_type );
307 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
308 // initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
309 // initContext because of a function type can contain object declarations in the return and parameter types. So
310 // each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
311 // the RHS.
312 GuardValue( currentObject );
313 currentObject = CurrentObject( objectDecl->get_type() );
314 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
315 // enumerator initializers should not use the enum type to initialize, since
316 // the enum type is still incomplete at this point. Use signed int instead.
317 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
318 }
319 }
320
321 template< typename PtrType >
322 void Resolver::handlePtrType( PtrType * type ) {
323 if ( type->get_dimension() ) {
324 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
325 }
326 }
327
328 void Resolver::previsit( ArrayType * at ) {
329 handlePtrType( at );
330 }
331
332 void Resolver::previsit( PointerType * pt ) {
333 handlePtrType( pt );
334 }
335
336 void Resolver::previsit( TypeDecl *typeDecl ) {
337 if ( typeDecl->get_base() ) {
338 Type *new_type = resolveTypeof( typeDecl->get_base(), indexer );
339 typeDecl->set_base( new_type );
340 } // if
341 }
342
343 void Resolver::previsit( FunctionDecl *functionDecl ) {
344#if 0
345 std::cerr << "resolver visiting functiondecl ";
346 functionDecl->print( std::cerr );
347 std::cerr << std::endl;
348#endif
349 Type *new_type = resolveTypeof( functionDecl->type, indexer );
350 functionDecl->set_type( new_type );
351 GuardValue( functionReturn );
352 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
353
354 {
355 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
356 // front of the function body.
357 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
358 indexer.addFunctionType( functionDecl->type );
359 std::list< Statement * > newStmts;
360 resolveWithExprs( functionDecl->withExprs, newStmts );
361 if ( functionDecl->statements ) {
362 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
363 } else {
364 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
365 }
366 }
367 }
368
369 void Resolver::postvisit( FunctionDecl *functionDecl ) {
370 // default value expressions have an environment which shouldn't be there and trips up later passes.
371 // xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
372 // see how it's useful.
373 for ( Declaration * d : functionDecl->type->parameters ) {
374 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
375 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
376 delete init->value->env;
377 init->value->env = nullptr;
378 }
379 }
380 }
381 }
382
383 void Resolver::previsit( EnumDecl * ) {
384 // in case we decide to allow nested enums
385 GuardValue( inEnumDecl );
386 inEnumDecl = true;
387 }
388
389 void Resolver::previsit( StaticAssertDecl * assertDecl ) {
390 findIntegralExpression( assertDecl->condition, indexer );
391 }
392
393 void Resolver::previsit( ExprStmt *exprStmt ) {
394 visit_children = false;
395 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
396 findVoidExpression( exprStmt->expr, indexer );
397 }
398
399 void Resolver::previsit( AsmExpr *asmExpr ) {
400 visit_children = false;
401 findVoidExpression( asmExpr->operand, indexer );
402 if ( asmExpr->get_inout() ) {
403 findVoidExpression( asmExpr->inout, indexer );
404 } // if
405 }
406
407 void Resolver::previsit( AsmStmt *asmStmt ) {
408 visit_children = false;
409 acceptAll( asmStmt->get_input(), *visitor );
410 acceptAll( asmStmt->get_output(), *visitor );
411 }
412
413 void Resolver::previsit( IfStmt *ifStmt ) {
414 findIntegralExpression( ifStmt->condition, indexer );
415 }
416
417 void Resolver::previsit( WhileStmt *whileStmt ) {
418 findIntegralExpression( whileStmt->condition, indexer );
419 }
420
421 void Resolver::previsit( ForStmt *forStmt ) {
422 if ( forStmt->condition ) {
423 findIntegralExpression( forStmt->condition, indexer );
424 } // if
425
426 if ( forStmt->increment ) {
427 findVoidExpression( forStmt->increment, indexer );
428 } // if
429 }
430
431 void Resolver::previsit( SwitchStmt *switchStmt ) {
432 GuardValue( currentObject );
433 findIntegralExpression( switchStmt->condition, indexer );
434
435 currentObject = CurrentObject( switchStmt->condition->result );
436 }
437
438 void Resolver::previsit( CaseStmt *caseStmt ) {
439 if ( caseStmt->condition ) {
440 std::list< InitAlternative > initAlts = currentObject.getOptions();
441 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
442 // must remove cast from case statement because RangeExpr cannot be cast.
443 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
444 findSingleExpression( newExpr, indexer );
445 // case condition cannot have a cast in C, so it must be removed, regardless of whether it performs a conversion.
446 // Ideally we would perform the conversion internally here.
447 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( newExpr ) ) {
448 newExpr = castExpr->arg;
449 castExpr->arg = nullptr;
450 std::swap( newExpr->env, castExpr->env );
451 delete castExpr;
452 }
453 caseStmt->condition = newExpr;
454 }
455 }
456
457 void Resolver::previsit( BranchStmt *branchStmt ) {
458 visit_children = false;
459 // must resolve the argument for a computed goto
460 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
461 if ( branchStmt->computedTarget ) {
462 // computed goto argument is void *
463 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
464 } // if
465 } // if
466 }
467
468 void Resolver::previsit( ReturnStmt *returnStmt ) {
469 visit_children = false;
470 if ( returnStmt->expr ) {
471 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
472 } // if
473 }
474
475 void Resolver::previsit( ThrowStmt *throwStmt ) {
476 visit_children = false;
477 // TODO: Replace *exception type with &exception type.
478 if ( throwStmt->get_expr() ) {
479 StructDecl * exception_decl =
480 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
481 assert( exception_decl );
482 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
483 findSingleExpression( throwStmt->expr, exceptType, indexer );
484 }
485 }
486
487 void Resolver::previsit( CatchStmt *catchStmt ) {
488 if ( catchStmt->cond ) {
489 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
490 }
491 }
492
493 template< typename iterator_t >
494 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
495 while( it != end && !(*it)->get_type()->get_mutex() ) {
496 it++;
497 }
498
499 return it != end;
500 }
501
502 void Resolver::previsit( WaitForStmt * stmt ) {
503 visit_children = false;
504
505 // Resolve all clauses first
506 for( auto& clause : stmt->clauses ) {
507
508 TypeEnvironment env;
509 AlternativeFinder funcFinder( indexer, env );
510
511 // Find all alternatives for a function in canonical form
512 funcFinder.findWithAdjustment( clause.target.function );
513
514 if ( funcFinder.get_alternatives().empty() ) {
515 stringstream ss;
516 ss << "Use of undeclared indentifier '";
517 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
518 ss << "' in call to waitfor";
519 SemanticError( stmt->location, ss.str() );
520 }
521
522 if(clause.target.arguments.empty()) {
523 SemanticError( stmt->location, "Waitfor clause must have at least one mutex parameter");
524 }
525
526 // Find all alternatives for all arguments in canonical form
527 std::vector< AlternativeFinder > argAlternatives;
528 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
529
530 // List all combinations of arguments
531 std::vector< AltList > possibilities;
532 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
533
534 AltList func_candidates;
535 std::vector< AltList > args_candidates;
536
537 // For every possible function :
538 // try matching the arguments to the parameters
539 // not the other way around because we have more arguments than parameters
540 SemanticErrorException errors;
541 for ( Alternative & func : funcFinder.get_alternatives() ) {
542 try {
543 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
544 if( !pointer ) {
545 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
546 }
547
548 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
549 if( !function ) {
550 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
551 }
552
553
554 {
555 auto param = function->parameters.begin();
556 auto param_end = function->parameters.end();
557
558 if( !advance_to_mutex( param, param_end ) ) {
559 SemanticError(function, "candidate function not viable: no mutex parameters\n");
560 }
561 }
562
563 Alternative newFunc( func );
564 // Strip reference from function
565 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
566
567 // For all the set of arguments we have try to match it with the parameter of the current function alternative
568 for ( auto & argsList : possibilities ) {
569
570 try {
571 // Declare data structures need for resolution
572 OpenVarSet openVars;
573 AssertionSet resultNeed, resultHave;
574 TypeEnvironment resultEnv( func.env );
575 makeUnifiableVars( function, openVars, resultNeed );
576 // add all type variables as open variables now so that those not used in the parameter
577 // list are still considered open.
578 resultEnv.add( function->forall );
579
580 // Load type variables from arguemnts into one shared space
581 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
582
583 // Make sure we don't widen any existing bindings
584 resultEnv.forbidWidening();
585
586 // Find any unbound type variables
587 resultEnv.extractOpenVars( openVars );
588
589 auto param = function->parameters.begin();
590 auto param_end = function->parameters.end();
591
592 int n_mutex_arg = 0;
593
594 // For every arguments of its set, check if it matches one of the parameter
595 // The order is important
596 for( auto & arg : argsList ) {
597
598 // Ignore non-mutex arguments
599 if( !advance_to_mutex( param, param_end ) ) {
600 // We ran out of parameters but still have arguments
601 // this function doesn't match
602 SemanticError( function, toString("candidate function not viable: too many mutex arguments, expected ", n_mutex_arg, "\n" ));
603 }
604
605 n_mutex_arg++;
606
607 // Check if the argument matches the parameter type in the current scope
608 if( ! unify( arg.expr->get_result(), (*param)->get_type(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
609 // Type doesn't match
610 stringstream ss;
611 ss << "candidate function not viable: no known convertion from '";
612 (*param)->get_type()->print( ss );
613 ss << "' to '";
614 arg.expr->get_result()->print( ss );
615 ss << "' with env '";
616 resultEnv.print(ss);
617 ss << "'\n";
618 SemanticError( function, ss.str() );
619 }
620
621 param++;
622 }
623
624 // All arguments match !
625
626 // Check if parameters are missing
627 if( advance_to_mutex( param, param_end ) ) {
628 // We ran out of arguments but still have parameters left
629 // this function doesn't match
630 SemanticError( function, toString("candidate function not viable: too few mutex arguments, expected ", n_mutex_arg, "\n" ));
631 }
632
633 // All parameters match !
634
635 // Finish the expressions to tie in the proper environments
636 finishExpr( newFunc.expr, resultEnv );
637 for( Alternative & alt : argsList ) {
638 finishExpr( alt.expr, resultEnv );
639 }
640
641 // This is a match store it and save it for later
642 func_candidates.push_back( newFunc );
643 args_candidates.push_back( argsList );
644
645 }
646 catch( SemanticErrorException &e ) {
647 errors.append( e );
648 }
649 }
650 }
651 catch( SemanticErrorException &e ) {
652 errors.append( e );
653 }
654 }
655
656 // Make sure we got the right number of arguments
657 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
658 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
659 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
660 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
661 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
662
663 // Swap the results from the alternative with the unresolved values.
664 // Alternatives will handle deletion on destruction
665 std::swap( clause.target.function, func_candidates.front().expr );
666 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
667 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
668 }
669
670 // Resolve the conditions as if it were an IfStmt
671 // Resolve the statments normally
672 findSingleExpression( clause.condition, this->indexer );
673 clause.statement->accept( *visitor );
674 }
675
676
677 if( stmt->timeout.statement ) {
678 // Resolve the timeout as an size_t for now
679 // Resolve the conditions as if it were an IfStmt
680 // Resolve the statments normally
681 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
682 findSingleExpression( stmt->timeout.condition, this->indexer );
683 stmt->timeout.statement->accept( *visitor );
684 }
685
686 if( stmt->orelse.statement ) {
687 // Resolve the conditions as if it were an IfStmt
688 // Resolve the statments normally
689 findSingleExpression( stmt->orelse.condition, this->indexer );
690 stmt->orelse.statement->accept( *visitor );
691 }
692 }
693
694 bool isStructOrUnion( const Alternative & alt ) {
695 Type * t = alt.expr->result->stripReferences();
696 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
697 }
698
699 void Resolver::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
700 for ( Expression *& expr : withExprs ) {
701 // only struct- and union-typed expressions are viable candidates
702 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
703
704 // if with expression might be impure, create a temporary so that it is evaluated once
705 if ( Tuples::maybeImpure( expr ) ) {
706 static UniqueName tmpNamer( "_with_tmp_" );
707 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
708 expr = new VariableExpr( tmp );
709 newStmts.push_back( new DeclStmt( tmp ) );
710 if ( InitTweak::isConstructable( tmp->type ) ) {
711 // generate ctor/dtor and resolve them
712 tmp->init = InitTweak::genCtorInit( tmp );
713 tmp->accept( *visitor );
714 }
715 }
716 }
717 }
718
719 void Resolver::previsit( WithStmt * withStmt ) {
720 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
721 }
722
723 template< typename T >
724 bool isCharType( T t ) {
725 if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
726 return bt->get_kind() == BasicType::Char || bt->get_kind() == BasicType::SignedChar ||
727 bt->get_kind() == BasicType::UnsignedChar;
728 }
729 return false;
730 }
731
732 void Resolver::previsit( SingleInit *singleInit ) {
733 visit_children = false;
734 // resolve initialization using the possibilities as determined by the currentObject cursor
735 Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
736 findSingleExpression( newExpr, indexer );
737 InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
738
739 // move cursor to the object that is actually initialized
740 currentObject.setNext( initExpr->get_designation() );
741
742 // discard InitExpr wrapper and retain relevant pieces
743 newExpr = initExpr->expr;
744 initExpr->expr = nullptr;
745 std::swap( initExpr->env, newExpr->env );
746 // InitExpr may have inferParams in the case where the expression specializes a function pointer,
747 // and newExpr may already have inferParams of its own, so a simple swap is not sufficient.
748 newExpr->spliceInferParams( initExpr );
749 delete initExpr;
750
751 // get the actual object's type (may not exactly match what comes back from the resolver due to conversions)
752 Type * initContext = currentObject.getCurrentType();
753
754 removeExtraneousCast( newExpr, indexer );
755
756 // check if actual object's type is char[]
757 if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
758 if ( isCharType( at->get_base() ) ) {
759 // check if the resolved type is char *
760 if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
761 if ( isCharType( pt->get_base() ) ) {
762 if ( CastExpr *ce = dynamic_cast< CastExpr * >( newExpr ) ) {
763 // strip cast if we're initializing a char[] with a char *, e.g. char x[] = "hello";
764 newExpr = ce->get_arg();
765 ce->set_arg( nullptr );
766 std::swap( ce->env, newExpr->env );
767 delete ce;
768 }
769 }
770 }
771 }
772 }
773
774 // set initializer expr to resolved express
775 singleInit->value = newExpr;
776
777 // move cursor to next object in preparation for next initializer
778 currentObject.increment();
779 }
780
781 void Resolver::previsit( ListInit * listInit ) {
782 visit_children = false;
783 // move cursor into brace-enclosed initializer-list
784 currentObject.enterListInit();
785 // xxx - fix this so that the list isn't copied, iterator should be used to change current element
786 std::list<Designation *> newDesignations;
787 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
788 // iterate designations and initializers in pairs, moving the cursor to the current designated object and resolving
789 // the initializer against that object.
790 Designation * des = std::get<0>(p);
791 Initializer * init = std::get<1>(p);
792 newDesignations.push_back( currentObject.findNext( des ) );
793 init->accept( *visitor );
794 }
795 // set the set of 'resolved' designations and leave the brace-enclosed initializer-list
796 listInit->get_designations() = newDesignations; // xxx - memory management
797 currentObject.exitListInit();
798
799 // xxx - this part has not be folded into CurrentObject yet
800 // } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
801 // Type * base = tt->get_baseType()->get_base();
802 // if ( base ) {
803 // // know the implementation type, so try using that as the initContext
804 // ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
805 // currentObject = &tmpObj;
806 // visit( listInit );
807 // } else {
808 // // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
809 // Parent::visit( listInit );
810 // }
811 // } else {
812 }
813
814 // ConstructorInit - fall back on C-style initializer
815 void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
816 // could not find valid constructor, or found an intrinsic constructor
817 // fall back on C-style initializer
818 delete ctorInit->get_ctor();
819 ctorInit->set_ctor( NULL );
820 delete ctorInit->get_dtor();
821 ctorInit->set_dtor( NULL );
822 maybeAccept( ctorInit->get_init(), *visitor );
823 }
824
825 // needs to be callable from outside the resolver, so this is a standalone function
826 void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
827 assert( ctorInit );
828 PassVisitor<Resolver> resolver( indexer );
829 ctorInit->accept( resolver );
830 }
831
832 void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
833 assert( stmtExpr );
834 PassVisitor<Resolver> resolver( indexer );
835 stmtExpr->accept( resolver );
836 stmtExpr->computeResult();
837 // xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
838 }
839
840 void Resolver::previsit( ConstructorInit *ctorInit ) {
841 visit_children = false;
842 // xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
843 maybeAccept( ctorInit->ctor, *visitor );
844 maybeAccept( ctorInit->dtor, *visitor );
845
846 // found a constructor - can get rid of C-style initializer
847 delete ctorInit->init;
848 ctorInit->init = nullptr;
849
850 // intrinsic single parameter constructors and destructors do nothing. Since this was
851 // implicitly generated, there's no way for it to have side effects, so get rid of it
852 // to clean up generated code.
853 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
854 delete ctorInit->ctor;
855 ctorInit->ctor = nullptr;
856 }
857
858 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
859 delete ctorInit->dtor;
860 ctorInit->dtor = nullptr;
861 }
862
863 // xxx - todo -- what about arrays?
864 // if ( dtor == NULL && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
865 // // can reduce the constructor down to a SingleInit using the
866 // // second argument from the ctor call, since
867 // delete ctorInit->get_ctor();
868 // ctorInit->set_ctor( NULL );
869
870 // Expression * arg =
871 // ctorInit->set_init( new SingleInit( arg ) );
872 // }
873 }
874} // namespace ResolvExpr
875
876// Local Variables: //
877// tab-width: 4 //
878// mode: c++ //
879// compile-command: "make install" //
880// End: //
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