source: src/ResolvExpr/Resolver.cc@ 24de7b1

new-env with_gc
Last change on this file since 24de7b1 was f229fc2, checked in by Aaron Moss <a3moss@…>, 8 years ago

Modify resolver to use young-generation collection per-top-level expression
  • Property mode set to 100644
File size: 31.0 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/GC.h" // for new_generation, collect_young
25#include "Common/PassVisitor.h" // for PassVisitor
26#include "Common/SemanticError.h" // for SemanticError
27#include "Common/utility.h" // for ValueGuard, group_iterate
28#include "CurrentObject.h" // for CurrentObject
29#include "InitTweak/GenInit.h"
30#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
31#include "RenameVars.h" // for RenameVars, global_renamer
32#include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment
33#include "ResolveTypeof.h" // for resolveTypeof
34#include "Resolver.h"
35#include "SymTab/Autogen.h" // for SizeType
36#include "SymTab/Indexer.h" // for Indexer
37#include "SynTree/Declaration.h" // for ObjectDecl, TypeDecl, Declar...
38#include "SynTree/Expression.h" // for Expression, CastExpr, InitExpr
39#include "SynTree/Initializer.h" // for ConstructorInit, SingleInit
40#include "SynTree/Statement.h" // for ForStmt, Statement, BranchStmt
41#include "SynTree/Type.h" // for Type, BasicType, PointerType
42#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
43#include "SynTree/Visitor.h" // for acceptAll, maybeAccept
44#include "Tuples/Tuples.h"
45#include "typeops.h" // for extractResultType
46#include "Unify.h" // for unify
47
48using namespace std;
49
50namespace ResolvExpr {
51 struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
52 Resolver() {}
53 Resolver( const SymTab::Indexer & other ) {
54 indexer = other;
55 }
56
57 void previsit( FunctionDecl *functionDecl );
58 void postvisit( FunctionDecl *functionDecl );
59 void previsit( ObjectDecl *objectDecll );
60 void previsit( TypeDecl *typeDecl );
61 void previsit( EnumDecl * enumDecl );
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 void finishExpr( Expression *expr, const TypeEnvironment &env, TypeSubstitution * oldenv = nullptr ) {
130 expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
131 env.makeSubstitution( *expr->get_env() );
132 }
133
134 void removeExtraneousCast( Expression *& expr, const SymTab::Indexer & indexer ) {
135 if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
136 if ( ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, indexer ) ) {
137 // cast is to the same type as its argument, so it's unnecessary -- remove it
138 expr = castExpr->arg;
139 castExpr->arg = nullptr;
140 std::swap( expr->env, castExpr->env );
141 }
142 }
143 }
144 } // namespace
145
146 namespace {
147 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) {
148 assertf( untyped, "expected a non-null expression." );
149
150 new_generation(); // set up GC young generation for this top-level expression
151
152 TypeEnvironment env;
153 AlternativeFinder finder( indexer, env );
154 finder.find( untyped, adjust, prune, failFast );
155
156 #if 0
157 if ( finder.get_alternatives().size() != 1 ) {
158 std::cerr << "untyped expr is ";
159 untyped->print( std::cerr );
160 std::cerr << std::endl << "alternatives are:";
161 for ( const Alternative & alt : finder.get_alternatives() ) {
162 alt.print( std::cerr );
163 } // for
164 } // if
165 #endif
166
167 AltList candidates;
168 for ( Alternative & alt : finder.get_alternatives() ) {
169 if ( pred( alt ) ) {
170 candidates.push_back( std::move( alt ) );
171 }
172 }
173
174 // xxx - if > 1 alternative with same cost, ignore deleted and pick from remaining
175 // choose the lowest cost expression among the candidates
176 AltList winners;
177 findMinCost( candidates.begin(), candidates.end(), back_inserter( winners ) );
178 if ( winners.size() == 0 ) {
179 collect_young();
180 SemanticError( untyped, toString(
181 "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""),
182 "expression: ") );
183 } else if ( winners.size() != 1 ) {
184 std::ostringstream stream;
185 stream << "Cannot choose between " << winners.size() << " alternatives for "
186 << kindStr << (kindStr != "" ? " " : "") << "expression\n";
187 untyped->print( stream );
188 stream << " Alternatives are:\n";
189 printAlts( winners, stream, 1 );
190
191 collect_young();
192 SemanticError( untyped->location, stream.str() );
193 }
194
195 // there is one unambiguous interpretation - move the expression into the with statement
196 Alternative & choice = winners.front();
197 if ( findDeletedExpr( choice.expr ) ) {
198 collect_young( choice.expr );
199 SemanticError( choice.expr,
200 "Unique best alternative includes deleted identifier in " );
201 }
202 alt = std::move( choice );
203 collect_young( alt );
204 }
205
206 /// resolve `untyped` to the expression whose alternative satisfies `pred` with the lowest cost; kindStr is used for providing better error messages
207 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) {
208 if ( ! untyped ) return;
209 Alternative choice;
210 findUnfinishedKindExpression( untyped, choice, indexer, kindStr, pred, adjust, prune, failFast );
211 finishExpr( choice.expr, choice.env, untyped->env );
212 untyped = choice.expr;
213 choice.expr = nullptr;
214 }
215
216 bool standardAlternativeFilter( const Alternative & ) {
217 // currently don't need to filter, under normal circumstances.
218 // in the future, this may be useful for removing deleted expressions
219 return true;
220 }
221 } // namespace
222
223 // used in resolveTypeof
224 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer ) {
225 TypeEnvironment env;
226 return resolveInVoidContext( expr, indexer, env );
227 }
228
229 Expression * resolveInVoidContext( Expression *expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
230 // it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
231 // interpretations, an exception has already been thrown.
232 assertf( expr, "expected a non-null expression." );
233
234 auto untyped = new CastExpr{ expr }; // cast to void
235
236 // set up and resolve expression cast to void
237 Alternative choice;
238 findUnfinishedKindExpression( untyped, choice, indexer, "", standardAlternativeFilter, true );
239 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( choice.expr );
240 env = std::move( choice.env );
241
242 // clean up resolved expression
243 return castExpr->arg;
244 }
245
246 void findVoidExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
247 resetTyVarRenaming();
248 TypeEnvironment env;
249 Expression * newExpr = resolveInVoidContext( untyped, indexer, env );
250 finishExpr( newExpr, env, untyped->env );
251 untyped = newExpr;
252 }
253
254 void findSingleExpression( Expression *&untyped, const SymTab::Indexer &indexer ) {
255 findKindExpression( untyped, indexer, "", standardAlternativeFilter );
256 }
257
258 void findSingleExpression( Expression *& untyped, Type * type, const SymTab::Indexer & indexer ) {
259 assert( untyped && type );
260 untyped = new CastExpr( untyped, type );
261 findSingleExpression( untyped, indexer );
262 removeExtraneousCast( untyped, indexer );
263 }
264
265 namespace {
266 bool isIntegralType( const Alternative & alt ) {
267 Type * type = alt.expr->result;
268 if ( dynamic_cast< EnumInstType * >( type ) ) {
269 return true;
270 } else if ( BasicType *bt = dynamic_cast< BasicType * >( type ) ) {
271 return bt->isInteger();
272 } else if ( dynamic_cast< ZeroType* >( type ) != nullptr || dynamic_cast< OneType* >( type ) != nullptr ) {
273 return true;
274 } else {
275 return false;
276 } // if
277 }
278
279 void findIntegralExpression( Expression *& untyped, const SymTab::Indexer &indexer ) {
280 findKindExpression( untyped, indexer, "condition", isIntegralType );
281 }
282 }
283
284 void Resolver::previsit( ObjectDecl *objectDecl ) {
285 Type *new_type = resolveTypeof( objectDecl->get_type(), indexer );
286 objectDecl->set_type( new_type );
287 // To handle initialization of routine pointers, e.g., int (*fp)(int) = foo(), means that class-variable
288 // initContext is changed multiple time because the LHS is analysed twice. The second analysis changes
289 // initContext because of a function type can contain object declarations in the return and parameter types. So
290 // each value of initContext is retained, so the type on the first analysis is preserved and used for selecting
291 // the RHS.
292 GuardValue( currentObject );
293 currentObject = CurrentObject( objectDecl->get_type() );
294 if ( inEnumDecl && dynamic_cast< EnumInstType * >( objectDecl->get_type() ) ) {
295 // enumerator initializers should not use the enum type to initialize, since
296 // the enum type is still incomplete at this point. Use signed int instead.
297 currentObject = CurrentObject( new BasicType( Type::Qualifiers(), BasicType::SignedInt ) );
298 }
299 }
300
301 template< typename PtrType >
302 void Resolver::handlePtrType( PtrType * type ) {
303 if ( type->get_dimension() ) {
304 findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
305 }
306 }
307
308 void Resolver::previsit( ArrayType * at ) {
309 handlePtrType( at );
310 }
311
312 void Resolver::previsit( PointerType * pt ) {
313 handlePtrType( pt );
314 }
315
316 void Resolver::previsit( TypeDecl *typeDecl ) {
317 if ( typeDecl->get_base() ) {
318 Type *new_type = resolveTypeof( typeDecl->get_base(), indexer );
319 typeDecl->set_base( new_type );
320 } // if
321 }
322
323 void Resolver::previsit( FunctionDecl *functionDecl ) {
324#if 0
325 std::cerr << "resolver visiting functiondecl ";
326 functionDecl->print( std::cerr );
327 std::cerr << std::endl;
328#endif
329 Type *new_type = resolveTypeof( functionDecl->type, indexer );
330 functionDecl->set_type( new_type );
331 GuardValue( functionReturn );
332 functionReturn = ResolvExpr::extractResultType( functionDecl->type );
333
334 {
335 // resolve with-exprs with parameters in scope and add any newly generated declarations to the
336 // front of the function body.
337 auto guard = makeFuncGuard( [this]() { indexer.enterScope(); }, [this](){ indexer.leaveScope(); } );
338 indexer.addFunctionType( functionDecl->type );
339 std::list< Statement * > newStmts;
340 resolveWithExprs( functionDecl->withExprs, newStmts );
341 if ( functionDecl->statements ) {
342 functionDecl->statements->kids.splice( functionDecl->statements->kids.begin(), newStmts );
343 } else {
344 assertf( functionDecl->withExprs.empty() && newStmts.empty(), "Function %s without a body has with-clause and/or generated with declarations.", functionDecl->name.c_str() );
345 }
346 }
347 }
348
349 void Resolver::postvisit( FunctionDecl *functionDecl ) {
350 // default value expressions have an environment which shouldn't be there and trips up later passes.
351 // xxx - it might be necessary to somehow keep the information from this environment, but I can't currently
352 // see how it's useful.
353 for ( Declaration * d : functionDecl->type->parameters ) {
354 if ( ObjectDecl * obj = dynamic_cast< ObjectDecl * >( d ) ) {
355 if ( SingleInit * init = dynamic_cast< SingleInit * >( obj->init ) ) {
356 delete init->value->env;
357 init->value->env = nullptr;
358 }
359 }
360 }
361 }
362
363 void Resolver::previsit( EnumDecl * ) {
364 // in case we decide to allow nested enums
365 GuardValue( inEnumDecl );
366 inEnumDecl = true;
367 }
368
369 void Resolver::previsit( ExprStmt *exprStmt ) {
370 visit_children = false;
371 assertf( exprStmt->expr, "ExprStmt has null Expression in resolver" );
372 findVoidExpression( exprStmt->expr, indexer );
373 }
374
375 void Resolver::previsit( AsmExpr *asmExpr ) {
376 visit_children = false;
377 findVoidExpression( asmExpr->operand, indexer );
378 if ( asmExpr->get_inout() ) {
379 findVoidExpression( asmExpr->inout, indexer );
380 } // if
381 }
382
383 void Resolver::previsit( AsmStmt *asmStmt ) {
384 visit_children = false;
385 acceptAll( asmStmt->get_input(), *visitor );
386 acceptAll( asmStmt->get_output(), *visitor );
387 }
388
389 void Resolver::previsit( IfStmt *ifStmt ) {
390 findIntegralExpression( ifStmt->condition, indexer );
391 }
392
393 void Resolver::previsit( WhileStmt *whileStmt ) {
394 findIntegralExpression( whileStmt->condition, indexer );
395 }
396
397 void Resolver::previsit( ForStmt *forStmt ) {
398 if ( forStmt->condition ) {
399 findIntegralExpression( forStmt->condition, indexer );
400 } // if
401
402 if ( forStmt->increment ) {
403 findVoidExpression( forStmt->increment, indexer );
404 } // if
405 }
406
407 void Resolver::previsit( SwitchStmt *switchStmt ) {
408 GuardValue( currentObject );
409 findIntegralExpression( switchStmt->condition, indexer );
410
411 currentObject = CurrentObject( switchStmt->condition->result );
412 }
413
414 void Resolver::previsit( CaseStmt *caseStmt ) {
415 if ( caseStmt->get_condition() ) {
416 std::list< InitAlternative > initAlts = currentObject.getOptions();
417 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral expression." );
418 // must remove cast from case statement because RangeExpr cannot be cast.
419 Expression * newExpr = new CastExpr( caseStmt->condition, initAlts.front().type->clone() );
420 findSingleExpression( newExpr, indexer );
421 CastExpr * castExpr = strict_dynamic_cast< CastExpr * >( newExpr );
422 caseStmt->condition = castExpr->arg;
423 castExpr->arg = nullptr;
424 }
425 }
426
427 void Resolver::previsit( BranchStmt *branchStmt ) {
428 visit_children = false;
429 // must resolve the argument for a computed goto
430 if ( branchStmt->get_type() == BranchStmt::Goto ) { // check for computed goto statement
431 if ( branchStmt->computedTarget ) {
432 // computed goto argument is void *
433 findSingleExpression( branchStmt->computedTarget, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), indexer );
434 } // if
435 } // if
436 }
437
438 void Resolver::previsit( ReturnStmt *returnStmt ) {
439 visit_children = false;
440 if ( returnStmt->expr ) {
441 findSingleExpression( returnStmt->expr, functionReturn->clone(), indexer );
442 } // if
443 }
444
445 void Resolver::previsit( ThrowStmt *throwStmt ) {
446 visit_children = false;
447 // TODO: Replace *exception type with &exception type.
448 if ( throwStmt->get_expr() ) {
449 StructDecl * exception_decl =
450 indexer.lookupStruct( "__cfaabi_ehm__base_exception_t" );
451 assert( exception_decl );
452 Type * exceptType = new PointerType( noQualifiers, new StructInstType( noQualifiers, exception_decl ) );
453 findSingleExpression( throwStmt->expr, exceptType, indexer );
454 }
455 }
456
457 void Resolver::previsit( CatchStmt *catchStmt ) {
458 if ( catchStmt->cond ) {
459 findSingleExpression( catchStmt->cond, new BasicType( noQualifiers, BasicType::Bool ), indexer );
460 }
461 }
462
463 template< typename iterator_t >
464 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
465 while( it != end && !(*it)->get_type()->get_mutex() ) {
466 it++;
467 }
468
469 return it != end;
470 }
471
472 void Resolver::previsit( WaitForStmt * stmt ) {
473 visit_children = false;
474
475 // Resolve all clauses first
476 for( auto& clause : stmt->clauses ) {
477
478 TypeEnvironment env;
479 AlternativeFinder funcFinder( indexer, env );
480
481 // Find all alternatives for a function in canonical form
482 funcFinder.findWithAdjustment( clause.target.function );
483
484 if ( funcFinder.get_alternatives().empty() ) {
485 stringstream ss;
486 ss << "Use of undeclared indentifier '";
487 ss << strict_dynamic_cast<NameExpr*>( clause.target.function )->name;
488 ss << "' in call to waitfor";
489 SemanticError( stmt->location, ss.str() );
490 }
491
492 // Find all alternatives for all arguments in canonical form
493 std::vector< AlternativeFinder > argAlternatives;
494 funcFinder.findSubExprs( clause.target.arguments.begin(), clause.target.arguments.end(), back_inserter( argAlternatives ) );
495
496 // List all combinations of arguments
497 std::vector< AltList > possibilities;
498 combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
499
500 AltList func_candidates;
501 std::vector< AltList > args_candidates;
502
503 // For every possible function :
504 // try matching the arguments to the parameters
505 // not the other way around because we have more arguments than parameters
506 SemanticErrorException errors;
507 for ( Alternative & func : funcFinder.get_alternatives() ) {
508 try {
509 PointerType * pointer = dynamic_cast< PointerType* >( func.expr->get_result()->stripReferences() );
510 if( !pointer ) {
511 SemanticError( func.expr->get_result(), "candidate not viable: not a pointer type\n" );
512 }
513
514 FunctionType * function = dynamic_cast< FunctionType* >( pointer->get_base() );
515 if( !function ) {
516 SemanticError( pointer->get_base(), "candidate not viable: not a function type\n" );
517 }
518
519
520 {
521 auto param = function->parameters.begin();
522 auto param_end = function->parameters.end();
523
524 if( !advance_to_mutex( param, param_end ) ) {
525 SemanticError(function, "candidate function not viable: no mutex parameters\n");
526 }
527 }
528
529 Alternative newFunc( func );
530 // Strip reference from function
531 referenceToRvalueConversion( newFunc.expr, newFunc.cost );
532
533 // For all the set of arguments we have try to match it with the parameter of the current function alternative
534 for ( auto & argsList : possibilities ) {
535
536 try {
537 // Declare data structures need for resolution
538 OpenVarSet openVars;
539 AssertionSet resultNeed, resultHave;
540 TypeEnvironment resultEnv;
541
542 // Load type variables from arguemnts into one shared space
543 simpleCombineEnvironments( argsList.begin(), argsList.end(), resultEnv );
544
545 // Make sure we don't widen any existing bindings
546 for ( auto & i : resultEnv ) {
547 i.allowWidening = false;
548 }
549
550 // Find any unbound type variables
551 resultEnv.extractOpenVars( openVars );
552
553 auto param = function->parameters.begin();
554 auto param_end = function->parameters.end();
555
556 // For every arguments of its set, check if it matches one of the parameter
557 // The order is important
558 for( auto & arg : argsList ) {
559
560 // Ignore non-mutex arguments
561 if( !advance_to_mutex( param, param_end ) ) {
562 // We ran out of parameters but still have arguments
563 // this function doesn't match
564 SemanticError( function, "candidate function not viable: too many mutex arguments\n" );
565 }
566
567 // Check if the argument matches the parameter type in the current scope
568 if( ! unify( (*param)->get_type(), arg.expr->get_result(), resultEnv, resultNeed, resultHave, openVars, this->indexer ) ) {
569 // Type doesn't match
570 stringstream ss;
571 ss << "candidate function not viable: no known convertion from '";
572 arg.expr->get_result()->print( ss );
573 ss << "' to '";
574 (*param)->get_type()->print( ss );
575 ss << "'\n";
576 SemanticError( function, ss.str() );
577 }
578
579 param++;
580 }
581
582 // All arguments match !
583
584 // Check if parameters are missing
585 if( advance_to_mutex( param, param_end ) ) {
586 // We ran out of arguments but still have parameters left
587 // this function doesn't match
588 SemanticError( function, "candidate function not viable: too few mutex arguments\n" );
589 }
590
591 // All parameters match !
592
593 // Finish the expressions to tie in the proper environments
594 finishExpr( newFunc.expr, resultEnv );
595 for( Alternative & alt : argsList ) {
596 finishExpr( alt.expr, resultEnv );
597 }
598
599 // This is a match store it and save it for later
600 func_candidates.push_back( newFunc );
601 args_candidates.push_back( argsList );
602
603 }
604 catch( SemanticErrorException &e ) {
605 errors.append( e );
606 }
607 }
608 }
609 catch( SemanticErrorException &e ) {
610 errors.append( e );
611 }
612 }
613
614 // Make sure we got the right number of arguments
615 if( func_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for function in call to waitfor" ); top.append( errors ); throw top; }
616 if( args_candidates.empty() ) { SemanticErrorException top( stmt->location, "No alternatives for arguments in call to waitfor" ); top.append( errors ); throw top; }
617 if( func_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous function in call to waitfor" ); top.append( errors ); throw top; }
618 if( args_candidates.size() > 1 ) { SemanticErrorException top( stmt->location, "Ambiguous arguments in call to waitfor" ); top.append( errors ); throw top; }
619 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
620
621 // Swap the results from the alternative with the unresolved values.
622 // Alternatives will handle deletion on destruction
623 std::swap( clause.target.function, func_candidates.front().expr );
624 for( auto arg_pair : group_iterate( clause.target.arguments, args_candidates.front() ) ) {
625 std::swap ( std::get<0>( arg_pair), std::get<1>( arg_pair).expr );
626 }
627
628 // Resolve the conditions as if it were an IfStmt
629 // Resolve the statments normally
630 findSingleExpression( clause.condition, this->indexer );
631 clause.statement->accept( *visitor );
632 }
633
634
635 if( stmt->timeout.statement ) {
636 // Resolve the timeout as an size_t for now
637 // Resolve the conditions as if it were an IfStmt
638 // Resolve the statments normally
639 findSingleExpression( stmt->timeout.time, new BasicType( noQualifiers, BasicType::LongLongUnsignedInt ), this->indexer );
640 findSingleExpression( stmt->timeout.condition, this->indexer );
641 stmt->timeout.statement->accept( *visitor );
642 }
643
644 if( stmt->orelse.statement ) {
645 // Resolve the conditions as if it were an IfStmt
646 // Resolve the statments normally
647 findSingleExpression( stmt->orelse.condition, this->indexer );
648 stmt->orelse.statement->accept( *visitor );
649 }
650 }
651
652 bool isStructOrUnion( const Alternative & alt ) {
653 Type * t = alt.expr->result->stripReferences();
654 return dynamic_cast< StructInstType * >( t ) || dynamic_cast< UnionInstType * >( t );
655 }
656
657 void Resolver::resolveWithExprs( std::list< Expression * > & withExprs, std::list< Statement * > & newStmts ) {
658 for ( Expression *& expr : withExprs ) {
659 // only struct- and union-typed expressions are viable candidates
660 findKindExpression( expr, indexer, "with statement", isStructOrUnion );
661
662 // if with expression might be impure, create a temporary so that it is evaluated once
663 if ( Tuples::maybeImpure( expr ) ) {
664 static UniqueName tmpNamer( "_with_tmp_" );
665 ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
666 expr = new VariableExpr( tmp );
667 newStmts.push_back( new DeclStmt( tmp ) );
668 if ( InitTweak::isConstructable( tmp->type ) ) {
669 // generate ctor/dtor and resolve them
670 tmp->init = InitTweak::genCtorInit( tmp );
671 tmp->accept( *visitor );
672 }
673 }
674 }
675 }
676
677 void Resolver::previsit( WithStmt * withStmt ) {
678 resolveWithExprs( withStmt->exprs, stmtsToAddBefore );
679 }
680
681 template< typename T >
682 bool isCharType( T t ) {
683 if ( BasicType * bt = dynamic_cast< BasicType * >( t ) ) {
684 return bt->get_kind() == BasicType::Char || bt->get_kind() == BasicType::SignedChar ||
685 bt->get_kind() == BasicType::UnsignedChar;
686 }
687 return false;
688 }
689
690 void Resolver::previsit( SingleInit *singleInit ) {
691 visit_children = false;
692 // resolve initialization using the possibilities as determined by the currentObject cursor
693 Expression * newExpr = new UntypedInitExpr( singleInit->value, currentObject.getOptions() );
694 findSingleExpression( newExpr, indexer );
695 InitExpr * initExpr = strict_dynamic_cast< InitExpr * >( newExpr );
696
697 // move cursor to the object that is actually initialized
698 currentObject.setNext( initExpr->get_designation() );
699
700 // discard InitExpr wrapper and retain relevant pieces
701 newExpr = initExpr->expr;
702 initExpr->expr = nullptr;
703 std::swap( initExpr->env, newExpr->env );
704 std::swap( initExpr->inferParams, newExpr->inferParams ) ;
705
706 // get the actual object's type (may not exactly match what comes back from the resolver due to conversions)
707 Type * initContext = currentObject.getCurrentType();
708
709 removeExtraneousCast( newExpr, indexer );
710
711 // check if actual object's type is char[]
712 if ( ArrayType * at = dynamic_cast< ArrayType * >( initContext ) ) {
713 if ( isCharType( at->get_base() ) ) {
714 // check if the resolved type is char *
715 if ( PointerType * pt = dynamic_cast< PointerType *>( newExpr->get_result() ) ) {
716 if ( isCharType( pt->get_base() ) ) {
717 if ( CastExpr *ce = dynamic_cast< CastExpr * >( newExpr ) ) {
718 // strip cast if we're initializing a char[] with a char *, e.g. char x[] = "hello";
719 newExpr = ce->get_arg();
720 ce->set_arg( nullptr );
721 std::swap( ce->env, newExpr->env );
722 }
723 }
724 }
725 }
726 }
727
728 // set initializer expr to resolved express
729 singleInit->value = newExpr;
730
731 // move cursor to next object in preparation for next initializer
732 currentObject.increment();
733 }
734
735 void Resolver::previsit( ListInit * listInit ) {
736 visit_children = false;
737 // move cursor into brace-enclosed initializer-list
738 currentObject.enterListInit();
739 // xxx - fix this so that the list isn't copied, iterator should be used to change current element
740 std::list<Designation *> newDesignations;
741 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
742 // iterate designations and initializers in pairs, moving the cursor to the current designated object and resolving
743 // the initializer against that object.
744 Designation * des = std::get<0>(p);
745 Initializer * init = std::get<1>(p);
746 newDesignations.push_back( currentObject.findNext( des ) );
747 init->accept( *visitor );
748 }
749 // set the set of 'resolved' designations and leave the brace-enclosed initializer-list
750 listInit->get_designations() = newDesignations; // xxx - memory management
751 currentObject.exitListInit();
752
753 // xxx - this part has not be folded into CurrentObject yet
754 // } else if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( initContext ) ) {
755 // Type * base = tt->get_baseType()->get_base();
756 // if ( base ) {
757 // // know the implementation type, so try using that as the initContext
758 // ObjectDecl tmpObj( "", Type::StorageClasses(), LinkageSpec::Cforall, nullptr, base->clone(), nullptr );
759 // currentObject = &tmpObj;
760 // visit( listInit );
761 // } else {
762 // // missing implementation type -- might be an unknown type variable, so try proceeding with the current init context
763 // Parent::visit( listInit );
764 // }
765 // } else {
766 }
767
768 // ConstructorInit - fall back on C-style initializer
769 void Resolver::fallbackInit( ConstructorInit * ctorInit ) {
770 // could not find valid constructor, or found an intrinsic constructor
771 // fall back on C-style initializer
772 ctorInit->set_ctor( nullptr );
773 ctorInit->set_dtor( nullptr );
774 maybeAccept( ctorInit->get_init(), *visitor );
775 }
776
777 // needs to be callable from outside the resolver, so this is a standalone function
778 void resolveCtorInit( ConstructorInit * ctorInit, const SymTab::Indexer & indexer ) {
779 assert( ctorInit );
780 PassVisitor<Resolver> resolver( indexer );
781 ctorInit->accept( resolver );
782 }
783
784 void resolveStmtExpr( StmtExpr * stmtExpr, const SymTab::Indexer & indexer ) {
785 assert( stmtExpr );
786 PassVisitor<Resolver> resolver( indexer );
787 stmtExpr->accept( resolver );
788 stmtExpr->computeResult();
789 // xxx - aggregate the environments from all statements? Possibly in AlternativeFinder instead?
790 }
791
792 void Resolver::previsit( ConstructorInit *ctorInit ) {
793 visit_children = false;
794 // xxx - fallback init has been removed => remove fallbackInit function and remove complexity from FixInit and remove C-init from ConstructorInit
795 maybeAccept( ctorInit->ctor, *visitor );
796 maybeAccept( ctorInit->dtor, *visitor );
797
798 // found a constructor - can get rid of C-style initializer
799 ctorInit->init = nullptr;
800
801 // intrinsic single parameter constructors and destructors do nothing. Since this was
802 // implicitly generated, there's no way for it to have side effects, so get rid of it
803 // to clean up generated code.
804 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
805 ctorInit->ctor = nullptr;
806 }
807
808 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
809 ctorInit->dtor = nullptr;
810 }
811
812 // xxx - todo -- what about arrays?
813 // if ( dtor == NULL && InitTweak::isIntrinsicCallStmt( ctorInit->get_ctor() ) ) {
814 // // can reduce the constructor down to a SingleInit using the
815 // // second argument from the ctor call, since
816 // delete ctorInit->get_ctor();
817 // ctorInit->set_ctor( NULL );
818
819 // Expression * arg =
820 // ctorInit->set_init( new SingleInit( arg ) );
821 // }
822 }
823} // namespace ResolvExpr
824
825// Local Variables: //
826// tab-width: 4 //
827// mode: c++ //
828// compile-command: "make install" //
829// End: //
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