source: src/ResolvExpr/Resolver.cc@ 77d46c7

Last change on this file since 77d46c7 was 2345ab3, checked in by Andrew Beach <ajbeach@…>, 22 months ago

Clean-up of the chain mutator. Seems like it is underused.
  • Property mode set to 100644
File size: 44.8 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 : Aaron B. Moss
10// Created On : Sun May 17 12:17:01 2015
11// Last Modified By : Andrew Beach
12// Last Modified On : Wed Apr 20 10:41:00 2022
13// Update Count : 248
14//
15
16#include <cassert> // for strict_dynamic_cast, assert
17#include <memory> // for allocator, allocator_traits<...
18#include <tuple> // for get
19#include <vector> // for vector
20
21#include "Candidate.hpp"
22#include "CandidateFinder.hpp"
23#include "CurrentObject.h" // for CurrentObject
24#include "RenameVars.h" // for RenameVars, global_renamer
25#include "Resolver.h"
26#include "ResolveTypeof.h"
27#include "ResolveMode.hpp" // for ResolveMode
28#include "typeops.h" // for extractResultType
29#include "Unify.h" // for unify
30#include "CompilationState.h"
31#include "AST/Decl.hpp"
32#include "AST/Init.hpp"
33#include "AST/Pass.hpp"
34#include "AST/Print.hpp"
35#include "AST/SymbolTable.hpp"
36#include "AST/Type.hpp"
37#include "Common/Eval.h" // for eval
38#include "Common/Iterate.hpp" // for group_iterate
39#include "Common/SemanticError.h" // for SemanticError
40#include "Common/Stats/ResolveTime.h" // for ResolveTime::start(), ResolveTime::stop()
41#include "Common/ToString.hpp" // for toCString
42#include "Common/UniqueName.h" // for UniqueName
43#include "InitTweak/GenInit.h"
44#include "InitTweak/InitTweak.h" // for isIntrinsicSingleArgCallStmt
45#include "SymTab/Mangler.h" // for Mangler
46#include "Tuples/Tuples.h"
47#include "Validate/FindSpecialDecls.h" // for SizeType
48
49using namespace std;
50
51namespace ResolvExpr {
52 template< typename iterator_t >
53 inline bool advance_to_mutex( iterator_t & it, const iterator_t & end ) {
54 while( it != end && !(*it)->get_type()->get_mutex() ) {
55 it++;
56 }
57
58 return it != end;
59 }
60
61 namespace {
62 /// Finds deleted expressions in an expression tree
63 struct DeleteFinder final : public ast::WithShortCircuiting, public ast::WithVisitorRef<DeleteFinder> {
64 const ast::DeletedExpr * result = nullptr;
65
66 void previsit( const ast::DeletedExpr * expr ) {
67 if ( result ) { visit_children = false; }
68 else { result = expr; }
69 }
70
71 void previsit( const ast::Expr * expr ) {
72 if ( result ) { visit_children = false; }
73 if (expr->inferred.hasParams()) {
74 for (auto & imp : expr->inferred.inferParams() ) {
75 imp.second.expr->accept(*visitor);
76 }
77 }
78 }
79 };
80
81 struct ResolveDesignators final : public ast::WithShortCircuiting {
82 ResolveContext& context;
83 bool result = false;
84
85 ResolveDesignators( ResolveContext& _context ): context{_context} {};
86
87 void previsit( const ast::Node * ) {
88 // short circuit if we already know there are designations
89 if ( result ) visit_children = false;
90 }
91
92 void previsit( const ast::Designation * des ) {
93 if ( result ) visit_children = false;
94 else if ( ! des->designators.empty() ) {
95 if ( (des->designators.size() == 1) ) {
96 const ast::Expr * designator = des->designators.at(0);
97 if ( const ast::NameExpr * designatorName = dynamic_cast<const ast::NameExpr *>(designator) ) {
98 auto candidates = context.symtab.lookupId(designatorName->name);
99 for ( auto candidate : candidates ) {
100 if ( dynamic_cast<const ast::EnumInstType *>(candidate.id->get_type()) ) {
101 result = true;
102 break;
103 }
104 }
105 }
106 }
107 visit_children = false;
108 }
109 }
110 };
111 } // anonymous namespace
112 /// Check if this expression is or includes a deleted expression
113 const ast::DeletedExpr * findDeletedExpr( const ast::Expr * expr ) {
114 return ast::Pass<DeleteFinder>::read( expr );
115 }
116
117 namespace {
118 /// always-accept candidate filter
119 bool anyCandidate( const Candidate & ) { return true; }
120
121 /// Calls the CandidateFinder and finds the single best candidate
122 CandidateRef findUnfinishedKindExpression(
123 const ast::Expr * untyped, const ResolveContext & context, const std::string & kind,
124 std::function<bool(const Candidate &)> pred = anyCandidate, ResolveMode mode = {}
125 ) {
126 if ( ! untyped ) return nullptr;
127
128 // xxx - this isn't thread-safe, but should work until we parallelize the resolver
129 static unsigned recursion_level = 0;
130
131 ++recursion_level;
132 ast::TypeEnvironment env;
133 CandidateFinder finder( context, env );
134 finder.allowVoid = true;
135 finder.find( untyped, recursion_level == 1 ? mode.atTopLevel() : mode );
136 --recursion_level;
137
138 // produce a filtered list of candidates
139 CandidateList candidates;
140 for ( auto & cand : finder.candidates ) {
141 if ( pred( *cand ) ) { candidates.emplace_back( cand ); }
142 }
143
144 // produce invalid error if no candidates
145 if ( candidates.empty() ) {
146 SemanticError( untyped,
147 toString( "No reasonable alternatives for ", kind, (kind != "" ? " " : ""),
148 "expression: ") );
149 }
150
151 // search for cheapest candidate
152 CandidateList winners;
153 bool seen_undeleted = false;
154 for ( CandidateRef & cand : candidates ) {
155 int c = winners.empty() ? -1 : cand->cost.compare( winners.front()->cost );
156
157 if ( c > 0 ) continue; // skip more expensive than winner
158
159 if ( c < 0 ) {
160 // reset on new cheapest
161 seen_undeleted = ! findDeletedExpr( cand->expr );
162 winners.clear();
163 } else /* if ( c == 0 ) */ {
164 if ( findDeletedExpr( cand->expr ) ) {
165 // skip deleted expression if already seen one equivalent-cost not
166 if ( seen_undeleted ) continue;
167 } else if ( ! seen_undeleted ) {
168 // replace list of equivalent-cost deleted expressions with one non-deleted
169 winners.clear();
170 seen_undeleted = true;
171 }
172 }
173
174 winners.emplace_back( std::move( cand ) );
175 }
176
177 // promote candidate.cvtCost to .cost
178 // promoteCvtCost( winners );
179
180 // produce ambiguous errors, if applicable
181 if ( winners.size() != 1 ) {
182 std::ostringstream stream;
183 stream << "Cannot choose between " << winners.size() << " alternatives for "
184 << kind << (kind != "" ? " " : "") << "expression\n";
185 ast::print( stream, untyped );
186 stream << " Alternatives are:\n";
187 print( stream, winners, 1 );
188 SemanticError( untyped->location, stream.str() );
189 }
190
191 // single selected choice
192 CandidateRef & choice = winners.front();
193
194 // fail on only expression deleted
195 if ( ! seen_undeleted ) {
196 SemanticError( untyped->location, choice->expr.get(), "Unique best alternative "
197 "includes deleted identifier in " );
198 }
199
200 return std::move( choice );
201 }
202
203 /// Strips extraneous casts out of an expression
204 struct StripCasts final {
205 const ast::Expr * postvisit( const ast::CastExpr * castExpr ) {
206 if (
207 castExpr->isGenerated == ast::GeneratedCast
208 && typesCompatible( castExpr->arg->result, castExpr->result )
209 ) {
210 // generated cast is the same type as its argument, remove it after keeping env
211 return ast::mutate_field(
212 castExpr->arg.get(), &ast::Expr::env, castExpr->env );
213 }
214 return castExpr;
215 }
216
217 static void strip( ast::ptr< ast::Expr > & expr ) {
218 ast::Pass< StripCasts > stripper;
219 expr = expr->accept( stripper );
220 }
221 };
222
223 /// Swaps argument into expression pointer, saving original environment
224 void swap_and_save_env( ast::ptr< ast::Expr > & expr, const ast::Expr * newExpr ) {
225 ast::ptr< ast::TypeSubstitution > env = expr->env;
226 expr.set_and_mutate( newExpr )->env = env;
227 }
228
229 /// Removes cast to type of argument (unlike StripCasts, also handles non-generated casts)
230 void removeExtraneousCast( ast::ptr<ast::Expr> & expr ) {
231 if ( const ast::CastExpr * castExpr = expr.as< ast::CastExpr >() ) {
232 if ( typesCompatible( castExpr->arg->result, castExpr->result ) ) {
233 // cast is to the same type as its argument, remove it
234 swap_and_save_env( expr, castExpr->arg );
235 }
236 }
237 }
238
239
240 } // anonymous namespace
241/// Establish post-resolver invariants for expressions
242 void finishExpr(
243 ast::ptr< ast::Expr > & expr, const ast::TypeEnvironment & env,
244 const ast::TypeSubstitution * oldenv = nullptr
245 ) {
246 // set up new type substitution for expression
247 ast::ptr< ast::TypeSubstitution > newenv =
248 oldenv ? oldenv : new ast::TypeSubstitution{};
249 env.writeToSubstitution( *newenv.get_and_mutate() );
250 expr.get_and_mutate()->env = std::move( newenv );
251 // remove unncecessary casts
252 StripCasts::strip( expr );
253 }
254
255 ast::ptr< ast::Expr > resolveInVoidContext(
256 const ast::Expr * expr, const ResolveContext & context,
257 ast::TypeEnvironment & env
258 ) {
259 assertf( expr, "expected a non-null expression" );
260
261 // set up and resolve expression cast to void
262 ast::ptr< ast::CastExpr > untyped = new ast::CastExpr{ expr };
263 CandidateRef choice = findUnfinishedKindExpression(
264 untyped, context, "", anyCandidate, ResolveMode::withAdjustment() );
265
266 // a cast expression has either 0 or 1 interpretations (by language rules);
267 // if 0, an exception has already been thrown, and this code will not run
268 const ast::CastExpr * castExpr = choice->expr.strict_as< ast::CastExpr >();
269 env = std::move( choice->env );
270
271 return castExpr->arg;
272 }
273
274 /// Resolve `untyped` to the expression whose candidate is the best match for a `void`
275 /// context.
276 ast::ptr< ast::Expr > findVoidExpression(
277 const ast::Expr * untyped, const ResolveContext & context
278 ) {
279 ast::TypeEnvironment env;
280 ast::ptr< ast::Expr > newExpr = resolveInVoidContext( untyped, context, env );
281 finishExpr( newExpr, env, untyped->env );
282 return newExpr;
283 }
284
285 namespace {
286
287
288 /// resolve `untyped` to the expression whose candidate satisfies `pred` with the
289 /// lowest cost, returning the resolved version
290 ast::ptr< ast::Expr > findKindExpression(
291 const ast::Expr * untyped, const ResolveContext & context,
292 std::function<bool(const Candidate &)> pred = anyCandidate,
293 const std::string & kind = "", ResolveMode mode = {}
294 ) {
295 if ( ! untyped ) return {};
296 CandidateRef choice =
297 findUnfinishedKindExpression( untyped, context, kind, pred, mode );
298 ResolvExpr::finishExpr( choice->expr, choice->env, untyped->env );
299 return std::move( choice->expr );
300 }
301
302 /// Resolve `untyped` to the single expression whose candidate is the best match
303 ast::ptr< ast::Expr > findSingleExpression(
304 const ast::Expr * untyped, const ResolveContext & context
305 ) {
306 Stats::ResolveTime::start( untyped );
307 auto res = findKindExpression( untyped, context );
308 Stats::ResolveTime::stop();
309 return res;
310 }
311 } // anonymous namespace
312
313 ast::ptr< ast::Expr > findSingleExpression(
314 const ast::Expr * untyped, const ast::Type * type,
315 const ResolveContext & context
316 ) {
317 assert( untyped && type );
318 ast::ptr< ast::Expr > castExpr = new ast::CastExpr{ untyped, type };
319 ast::ptr< ast::Expr > newExpr = findSingleExpression( castExpr, context );
320 removeExtraneousCast( newExpr );
321 return newExpr;
322 }
323
324 namespace {
325 bool structOrUnion( const Candidate & i ) {
326 const ast::Type * t = i.expr->result->stripReferences();
327 return dynamic_cast< const ast::StructInstType * >( t ) || dynamic_cast< const ast::UnionInstType * >( t );
328 }
329 /// Predicate for "Candidate has integral type"
330 bool hasIntegralType( const Candidate & i ) {
331 const ast::Type * type = i.expr->result;
332
333 if ( auto bt = dynamic_cast< const ast::BasicType * >( type ) ) {
334 return bt->isInteger();
335 } else if (
336 dynamic_cast< const ast::EnumInstType * >( type )
337 || dynamic_cast< const ast::ZeroType * >( type )
338 || dynamic_cast< const ast::OneType * >( type )
339 ) {
340 return true;
341 } else return false;
342 }
343
344 /// Resolve `untyped` as an integral expression, returning the resolved version
345 ast::ptr< ast::Expr > findIntegralExpression(
346 const ast::Expr * untyped, const ResolveContext & context
347 ) {
348 return findKindExpression( untyped, context, hasIntegralType, "condition" );
349 }
350
351 /// check if a type is a character type
352 bool isCharType( const ast::Type * t ) {
353 if ( auto bt = dynamic_cast< const ast::BasicType * >( t ) ) {
354 return bt->kind == ast::BasicType::Char
355 || bt->kind == ast::BasicType::SignedChar
356 || bt->kind == ast::BasicType::UnsignedChar;
357 }
358 return false;
359 }
360
361 /// Advance a type itertor to the next mutex parameter
362 template<typename Iter>
363 inline bool nextMutex( Iter & it, const Iter & end ) {
364 while ( it != end && ! (*it)->is_mutex() ) { ++it; }
365 return it != end;
366 }
367 }
368
369 class Resolver final
370 : public ast::WithSymbolTable, public ast::WithGuards,
371 public ast::WithVisitorRef<Resolver>, public ast::WithShortCircuiting,
372 public ast::WithStmtsToAdd<> {
373
374 ast::ptr< ast::Type > functionReturn = nullptr;
375 ast::CurrentObject currentObject;
376 // for work previously in GenInit
377 static InitTweak::ManagedTypes managedTypes;
378 ResolveContext context;
379
380 bool inEnumDecl = false;
381
382 public:
383 static size_t traceId;
384 Resolver( const ast::TranslationGlobal & global ) :
385 ast::WithSymbolTable(ast::SymbolTable::ErrorDetection::ValidateOnAdd),
386 context{ symtab, global } {}
387 Resolver( const ResolveContext & context ) :
388 ast::WithSymbolTable{ context.symtab },
389 context{ symtab, context.global } {}
390
391 const ast::FunctionDecl * previsit( const ast::FunctionDecl * );
392 const ast::FunctionDecl * postvisit( const ast::FunctionDecl * );
393 const ast::ObjectDecl * previsit( const ast::ObjectDecl * );
394 void previsit( const ast::AggregateDecl * );
395 void previsit( const ast::StructDecl * );
396 void previsit( const ast::EnumDecl * );
397 const ast::StaticAssertDecl * previsit( const ast::StaticAssertDecl * );
398
399 const ast::ArrayType * previsit( const ast::ArrayType * );
400 const ast::PointerType * previsit( const ast::PointerType * );
401
402 const ast::ExprStmt * previsit( const ast::ExprStmt * );
403 const ast::AsmExpr * previsit( const ast::AsmExpr * );
404 const ast::AsmStmt * previsit( const ast::AsmStmt * );
405 const ast::IfStmt * previsit( const ast::IfStmt * );
406 const ast::WhileDoStmt * previsit( const ast::WhileDoStmt * );
407 const ast::ForStmt * previsit( const ast::ForStmt * );
408 const ast::SwitchStmt * previsit( const ast::SwitchStmt * );
409 const ast::CaseClause * previsit( const ast::CaseClause * );
410 const ast::BranchStmt * previsit( const ast::BranchStmt * );
411 const ast::ReturnStmt * previsit( const ast::ReturnStmt * );
412 const ast::ThrowStmt * previsit( const ast::ThrowStmt * );
413 const ast::CatchClause * previsit( const ast::CatchClause * );
414 const ast::CatchClause * postvisit( const ast::CatchClause * );
415 const ast::WaitForStmt * previsit( const ast::WaitForStmt * );
416 const ast::WithStmt * previsit( const ast::WithStmt * );
417
418 const ast::SingleInit * previsit( const ast::SingleInit * );
419 const ast::ListInit * previsit( const ast::ListInit * );
420 const ast::ConstructorInit * previsit( const ast::ConstructorInit * );
421
422 void resolveWithExprs(std::vector<ast::ptr<ast::Expr>> & exprs, std::list<ast::ptr<ast::Stmt>> & stmtsToAdd);
423
424 void beginScope() { managedTypes.beginScope(); }
425 void endScope() { managedTypes.endScope(); }
426 bool on_error(ast::ptr<ast::Decl> & decl);
427 };
428 // size_t Resolver::traceId = Stats::Heap::new_stacktrace_id("Resolver");
429
430 InitTweak::ManagedTypes Resolver::managedTypes;
431
432 void resolve( ast::TranslationUnit& translationUnit ) {
433 ast::Pass< Resolver >::run( translationUnit, translationUnit.global );
434 }
435
436 ast::ptr< ast::Init > resolveCtorInit(
437 const ast::ConstructorInit * ctorInit, const ResolveContext & context
438 ) {
439 assert( ctorInit );
440 ast::Pass< Resolver > resolver( context );
441 return ctorInit->accept( resolver );
442 }
443
444 const ast::Expr * resolveStmtExpr(
445 const ast::StmtExpr * stmtExpr, const ResolveContext & context
446 ) {
447 assert( stmtExpr );
448 ast::Pass< Resolver > resolver( context );
449 auto ret = mutate(stmtExpr->accept(resolver));
450 strict_dynamic_cast< ast::StmtExpr * >( ret )->computeResult();
451 return ret;
452 }
453
454 namespace {
455 const ast::Attribute * handleAttribute(const CodeLocation & loc, const ast::Attribute * attr, const ResolveContext & context) {
456 std::string name = attr->normalizedName();
457 if (name == "constructor" || name == "destructor") {
458 if (attr->params.size() == 1) {
459 auto arg = attr->params.front();
460 auto resolved = ResolvExpr::findSingleExpression( arg, new ast::BasicType( ast::BasicType::LongLongSignedInt ), context );
461 auto result = eval(arg);
462
463 auto mutAttr = mutate(attr);
464 mutAttr->params.front() = resolved;
465 if (! result.hasKnownValue) {
466 SemanticWarning(loc, Warning::GccAttributes,
467 toCString( name, " priorities must be integers from 0 to 65535 inclusive: ", arg ) );
468 }
469 else {
470 auto priority = result.knownValue;
471 if (priority < 101) {
472 SemanticWarning(loc, Warning::GccAttributes,
473 toCString( name, " priorities from 0 to 100 are reserved for the implementation" ) );
474 } else if (priority < 201 && ! buildingLibrary()) {
475 SemanticWarning(loc, Warning::GccAttributes,
476 toCString( name, " priorities from 101 to 200 are reserved for the implementation" ) );
477 }
478 }
479 return mutAttr;
480 } else if (attr->params.size() > 1) {
481 SemanticWarning(loc, Warning::GccAttributes, toCString( "too many arguments to ", name, " attribute" ) );
482 } else {
483 SemanticWarning(loc, Warning::GccAttributes, toCString( "too few arguments to ", name, " attribute" ) );
484 }
485 }
486 return attr;
487 }
488 }
489
490 const ast::FunctionDecl * Resolver::previsit( const ast::FunctionDecl * functionDecl ) {
491 GuardValue( functionReturn );
492
493 assert (functionDecl->unique());
494 if (!functionDecl->has_body() && !functionDecl->withExprs.empty()) {
495 SemanticError(functionDecl->location, functionDecl, "Function without body has with declarations");
496 }
497
498 if (!functionDecl->isTypeFixed) {
499 auto mutDecl = mutate(functionDecl);
500 auto mutType = mutDecl->type.get_and_mutate();
501
502 for (auto & attr: mutDecl->attributes) {
503 attr = handleAttribute(mutDecl->location, attr, context );
504 }
505
506 // handle assertions
507
508 symtab.enterScope();
509 mutType->forall.clear();
510 mutType->assertions.clear();
511 for (auto & typeParam : mutDecl->type_params) {
512 symtab.addType(typeParam);
513 mutType->forall.emplace_back(new ast::TypeInstType(typeParam));
514 }
515 for (auto & asst : mutDecl->assertions) {
516 asst = fixObjectType(asst.strict_as<ast::ObjectDecl>(), context);
517 symtab.addId(asst);
518 mutType->assertions.emplace_back(new ast::VariableExpr(functionDecl->location, asst));
519 }
520
521 // temporarily adds params to symbol table.
522 // actual scoping rules for params and withexprs differ - see Pass::visit(FunctionDecl)
523
524 std::vector<ast::ptr<ast::Type>> paramTypes;
525 std::vector<ast::ptr<ast::Type>> returnTypes;
526
527 for (auto & param : mutDecl->params) {
528 param = fixObjectType(param.strict_as<ast::ObjectDecl>(), context);
529 symtab.addId(param);
530 paramTypes.emplace_back(param->get_type());
531 }
532 for (auto & ret : mutDecl->returns) {
533 ret = fixObjectType(ret.strict_as<ast::ObjectDecl>(), context);
534 returnTypes.emplace_back(ret->get_type());
535 }
536 // since function type in decl is just a view of param types, need to update that as well
537 mutType->params = std::move(paramTypes);
538 mutType->returns = std::move(returnTypes);
539
540 auto renamedType = strict_dynamic_cast<const ast::FunctionType *>(renameTyVars(mutType, RenameMode::GEN_EXPR_ID));
541
542 std::list<ast::ptr<ast::Stmt>> newStmts;
543 resolveWithExprs (mutDecl->withExprs, newStmts);
544
545 if (mutDecl->stmts) {
546 auto mutStmt = mutDecl->stmts.get_and_mutate();
547 mutStmt->kids.splice(mutStmt->kids.begin(), std::move(newStmts));
548 mutDecl->stmts = mutStmt;
549 }
550
551 symtab.leaveScope();
552
553 mutDecl->type = renamedType;
554 mutDecl->mangleName = Mangle::mangle(mutDecl);
555 mutDecl->isTypeFixed = true;
556 functionDecl = mutDecl;
557 }
558 managedTypes.handleDWT(functionDecl);
559
560 functionReturn = extractResultType( functionDecl->type );
561 return functionDecl;
562 }
563
564 const ast::FunctionDecl * Resolver::postvisit( const ast::FunctionDecl * functionDecl ) {
565 // default value expressions have an environment which shouldn't be there and trips up
566 // later passes.
567 assert( functionDecl->unique() );
568 ast::FunctionType * mutType = mutate( functionDecl->type.get() );
569
570 for ( unsigned i = 0 ; i < mutType->params.size() ; ++i ) {
571 if ( const ast::ObjectDecl * obj = mutType->params[i].as< ast::ObjectDecl >() ) {
572 if ( const ast::SingleInit * init = obj->init.as< ast::SingleInit >() ) {
573 if ( init->value->env == nullptr ) continue;
574 // clone initializer minus the initializer environment
575 auto mutParam = mutate( mutType->params[i].strict_as< ast::ObjectDecl >() );
576 auto mutInit = mutate( mutParam->init.strict_as< ast::SingleInit >() );
577 auto mutValue = mutate( mutInit->value.get() );
578
579 mutValue->env = nullptr;
580 mutInit->value = mutValue;
581 mutParam->init = mutInit;
582 mutType->params[i] = mutParam;
583
584 assert( ! mutType->params[i].strict_as< ast::ObjectDecl >()->init.strict_as< ast::SingleInit >()->value->env);
585 }
586 }
587 }
588 mutate_field(functionDecl, &ast::FunctionDecl::type, mutType);
589 return functionDecl;
590 }
591
592 const ast::ObjectDecl * Resolver::previsit( const ast::ObjectDecl * objectDecl ) {
593 // To handle initialization of routine pointers [e.g. int (*fp)(int) = foo()],
594 // class-variable `initContext` is changed multiple times because the LHS is analyzed
595 // twice. The second analysis changes `initContext` because a function type can contain
596 // object declarations in the return and parameter types. Therefore each value of
597 // `initContext` is retained so the type on the first analysis is preserved and used for
598 // selecting the RHS.
599 GuardValue( currentObject );
600
601 if ( inEnumDecl && dynamic_cast< const ast::EnumInstType * >( objectDecl->get_type() ) ) {
602 // enumerator initializers should not use the enum type to initialize, since the
603 // enum type is still incomplete at this point. Use `int` instead.
604
605 if ( auto enumBase = dynamic_cast< const ast::EnumInstType * >
606 ( objectDecl->get_type() )->base->base ) {
607 objectDecl = fixObjectType( objectDecl, context );
608 currentObject = ast::CurrentObject{
609 objectDecl->location,
610 enumBase
611 };
612 } else {
613 objectDecl = fixObjectType( objectDecl, context );
614 currentObject = ast::CurrentObject{
615 objectDecl->location, new ast::BasicType{ ast::BasicType::SignedInt } };
616 }
617
618 }
619 else {
620 if ( !objectDecl->isTypeFixed ) {
621 auto newDecl = fixObjectType(objectDecl, context);
622 auto mutDecl = mutate(newDecl);
623
624 // generate CtorInit wrapper when necessary.
625 // in certain cases, fixObjectType is called before reaching
626 // this object in visitor pass, thus disabling CtorInit codegen.
627 // this happens on aggregate members and function parameters.
628 if ( InitTweak::tryConstruct( mutDecl ) && ( managedTypes.isManaged( mutDecl ) || ((! isInFunction() || mutDecl->storage.is_static ) && ! InitTweak::isConstExpr( mutDecl->init ) ) ) ) {
629 // constructed objects cannot be designated
630 if ( InitTweak::isDesignated( mutDecl->init ) ) {
631 ast::Pass<ResolveDesignators> res( context );
632 maybe_accept( mutDecl->init.get(), res );
633 if ( !res.core.result ) {
634 SemanticError( mutDecl, "Cannot include designations in the initializer for a managed Object. If this is really what you want, then initialize with @=.\n" );
635 }
636 }
637 // constructed objects should not have initializers nested too deeply
638 if ( ! InitTweak::checkInitDepth( mutDecl ) ) SemanticError( mutDecl, "Managed object's initializer is too deep " );
639
640 mutDecl->init = InitTweak::genCtorInit( mutDecl->location, mutDecl );
641 }
642
643 objectDecl = mutDecl;
644 }
645 currentObject = ast::CurrentObject{ objectDecl->location, objectDecl->get_type() };
646 }
647
648 return objectDecl;
649 }
650
651 void Resolver::previsit( const ast::AggregateDecl * _aggDecl ) {
652 auto aggDecl = mutate(_aggDecl);
653 assertf(aggDecl == _aggDecl, "type declarations must be unique");
654
655 for (auto & member: aggDecl->members) {
656 // nested type decls are hoisted already. no need to do anything
657 if (auto obj = member.as<ast::ObjectDecl>()) {
658 member = fixObjectType(obj, context);
659 }
660 }
661 }
662
663 void Resolver::previsit( const ast::StructDecl * structDecl ) {
664 previsit(static_cast<const ast::AggregateDecl *>(structDecl));
665 managedTypes.handleStruct(structDecl);
666 }
667
668 void Resolver::previsit( const ast::EnumDecl * ) {
669 // in case we decide to allow nested enums
670 GuardValue( inEnumDecl );
671 inEnumDecl = true;
672 // don't need to fix types for enum fields
673 }
674
675 const ast::StaticAssertDecl * Resolver::previsit(
676 const ast::StaticAssertDecl * assertDecl
677 ) {
678 return ast::mutate_field(
679 assertDecl, &ast::StaticAssertDecl::cond,
680 findIntegralExpression( assertDecl->cond, context ) );
681 }
682
683 template< typename PtrType >
684 const PtrType * handlePtrType( const PtrType * type, const ResolveContext & context ) {
685 if ( type->dimension ) {
686 const ast::Type * sizeType = context.global.sizeType.get();
687 ast::ptr< ast::Expr > dimension = findSingleExpression( type->dimension, sizeType, context );
688 assertf(dimension->env->empty(), "array dimension expr has nonempty env");
689 dimension.get_and_mutate()->env = nullptr;
690 ast::mutate_field( type, &PtrType::dimension, dimension );
691 }
692 return type;
693 }
694
695 const ast::ArrayType * Resolver::previsit( const ast::ArrayType * at ) {
696 return handlePtrType( at, context );
697 }
698
699 const ast::PointerType * Resolver::previsit( const ast::PointerType * pt ) {
700 return handlePtrType( pt, context );
701 }
702
703 const ast::ExprStmt * Resolver::previsit( const ast::ExprStmt * exprStmt ) {
704 visit_children = false;
705 assertf( exprStmt->expr, "ExprStmt has null expression in resolver" );
706
707 return ast::mutate_field(
708 exprStmt, &ast::ExprStmt::expr, findVoidExpression( exprStmt->expr, context ) );
709 }
710
711 const ast::AsmExpr * Resolver::previsit( const ast::AsmExpr * asmExpr ) {
712 visit_children = false;
713
714 asmExpr = ast::mutate_field(
715 asmExpr, &ast::AsmExpr::operand, findVoidExpression( asmExpr->operand, context ) );
716
717 return asmExpr;
718 }
719
720 const ast::AsmStmt * Resolver::previsit( const ast::AsmStmt * asmStmt ) {
721 visitor->maybe_accept( asmStmt, &ast::AsmStmt::input );
722 visitor->maybe_accept( asmStmt, &ast::AsmStmt::output );
723 visit_children = false;
724 return asmStmt;
725 }
726
727 const ast::IfStmt * Resolver::previsit( const ast::IfStmt * ifStmt ) {
728 return ast::mutate_field(
729 ifStmt, &ast::IfStmt::cond, findIntegralExpression( ifStmt->cond, context ) );
730 }
731
732 const ast::WhileDoStmt * Resolver::previsit( const ast::WhileDoStmt * whileDoStmt ) {
733 return ast::mutate_field(
734 whileDoStmt, &ast::WhileDoStmt::cond, findIntegralExpression( whileDoStmt->cond, context ) );
735 }
736
737 const ast::ForStmt * Resolver::previsit( const ast::ForStmt * forStmt ) {
738 if ( forStmt->cond ) {
739 forStmt = ast::mutate_field(
740 forStmt, &ast::ForStmt::cond, findIntegralExpression( forStmt->cond, context ) );
741 }
742
743 if ( forStmt->inc ) {
744 forStmt = ast::mutate_field(
745 forStmt, &ast::ForStmt::inc, findVoidExpression( forStmt->inc, context ) );
746 }
747
748 return forStmt;
749 }
750
751 const ast::SwitchStmt * Resolver::previsit( const ast::SwitchStmt * switchStmt ) {
752 GuardValue( currentObject );
753 switchStmt = ast::mutate_field(
754 switchStmt, &ast::SwitchStmt::cond,
755 findIntegralExpression( switchStmt->cond, context ) );
756 currentObject = ast::CurrentObject{ switchStmt->location, switchStmt->cond->result };
757 return switchStmt;
758 }
759
760 const ast::CaseClause * Resolver::previsit( const ast::CaseClause * caseStmt ) {
761 if ( caseStmt->cond ) {
762 std::deque< ast::InitAlternative > initAlts = currentObject.getOptions();
763 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral "
764 "expression." );
765
766 ast::ptr< ast::Expr > untyped =
767 new ast::CastExpr{ caseStmt->location, caseStmt->cond, initAlts.front().type };
768 ast::ptr< ast::Expr > newExpr = findSingleExpression( untyped, context );
769
770 // case condition cannot have a cast in C, so it must be removed here, regardless of
771 // whether it would perform a conversion.
772 if ( const ast::CastExpr * castExpr = newExpr.as< ast::CastExpr >() ) {
773 swap_and_save_env( newExpr, castExpr->arg );
774 }
775
776 caseStmt = ast::mutate_field( caseStmt, &ast::CaseClause::cond, newExpr );
777 }
778 return caseStmt;
779 }
780
781 const ast::BranchStmt * Resolver::previsit( const ast::BranchStmt * branchStmt ) {
782 visit_children = false;
783 // must resolve the argument of a computed goto
784 if ( branchStmt->kind == ast::BranchStmt::Goto && branchStmt->computedTarget ) {
785 // computed goto argument is void*
786 ast::ptr< ast::Type > target = new ast::PointerType{ new ast::VoidType{} };
787 branchStmt = ast::mutate_field(
788 branchStmt, &ast::BranchStmt::computedTarget,
789 findSingleExpression( branchStmt->computedTarget, target, context ) );
790 }
791 return branchStmt;
792 }
793
794 const ast::ReturnStmt * Resolver::previsit( const ast::ReturnStmt * returnStmt ) {
795 visit_children = false;
796 if ( returnStmt->expr ) {
797 returnStmt = ast::mutate_field(
798 returnStmt, &ast::ReturnStmt::expr,
799 findSingleExpression( returnStmt->expr, functionReturn, context ) );
800 }
801 return returnStmt;
802 }
803
804 const ast::ThrowStmt * Resolver::previsit( const ast::ThrowStmt * throwStmt ) {
805 visit_children = false;
806 if ( throwStmt->expr ) {
807 const ast::StructDecl * exceptionDecl =
808 symtab.lookupStruct( "__cfaehm_base_exception_t" );
809 assert( exceptionDecl );
810 ast::ptr< ast::Type > exceptType =
811 new ast::PointerType{ new ast::StructInstType{ exceptionDecl } };
812 throwStmt = ast::mutate_field(
813 throwStmt, &ast::ThrowStmt::expr,
814 findSingleExpression( throwStmt->expr, exceptType, context ) );
815 }
816 return throwStmt;
817 }
818
819 const ast::CatchClause * Resolver::previsit( const ast::CatchClause * catchClause ) {
820 // Until we are very sure this invarent (ifs that move between passes have then)
821 // holds, check it. This allows a check for when to decode the mangling.
822 if ( auto ifStmt = catchClause->body.as<ast::IfStmt>() ) {
823 assert( ifStmt->then );
824 }
825 // Encode the catchStmt so the condition can see the declaration.
826 if ( catchClause->cond ) {
827 ast::CatchClause * clause = mutate( catchClause );
828 clause->body = new ast::IfStmt( clause->location, clause->cond, nullptr, clause->body );
829 clause->cond = nullptr;
830 return clause;
831 }
832 return catchClause;
833 }
834
835 const ast::CatchClause * Resolver::postvisit( const ast::CatchClause * catchClause ) {
836 // Decode the catchStmt so everything is stored properly.
837 const ast::IfStmt * ifStmt = catchClause->body.as<ast::IfStmt>();
838 if ( nullptr != ifStmt && nullptr == ifStmt->then ) {
839 assert( ifStmt->cond );
840 assert( ifStmt->else_ );
841 ast::CatchClause * clause = ast::mutate( catchClause );
842 clause->cond = ifStmt->cond;
843 clause->body = ifStmt->else_;
844 // ifStmt should be implicately deleted here.
845 return clause;
846 }
847 return catchClause;
848 }
849
850 const ast::WaitForStmt * Resolver::previsit( const ast::WaitForStmt * stmt ) {
851 visit_children = false;
852
853 // Resolve all clauses first
854 for ( unsigned i = 0; i < stmt->clauses.size(); ++i ) {
855 const ast::WaitForClause & clause = *stmt->clauses[i];
856
857 ast::TypeEnvironment env;
858 CandidateFinder funcFinder( context, env );
859
860 // Find all candidates for a function in canonical form
861 funcFinder.find( clause.target, ResolveMode::withAdjustment() );
862
863 if ( funcFinder.candidates.empty() ) {
864 stringstream ss;
865 ss << "Use of undeclared indentifier '";
866 ss << clause.target.strict_as< ast::NameExpr >()->name;
867 ss << "' in call to waitfor";
868 SemanticError( stmt->location, ss.str() );
869 }
870
871 if ( clause.target_args.empty() ) {
872 SemanticError( stmt->location,
873 "Waitfor clause must have at least one mutex parameter");
874 }
875
876 // Find all alternatives for all arguments in canonical form
877 std::vector< CandidateFinder > argFinders =
878 funcFinder.findSubExprs( clause.target_args );
879
880 // List all combinations of arguments
881 std::vector< CandidateList > possibilities;
882 combos( argFinders.begin(), argFinders.end(), back_inserter( possibilities ) );
883
884 // For every possible function:
885 // * try matching the arguments to the parameters, not the other way around because
886 // more arguments than parameters
887 CandidateList funcCandidates;
888 std::vector< CandidateList > argsCandidates;
889 SemanticErrorException errors;
890 for ( CandidateRef & func : funcFinder.candidates ) {
891 try {
892 auto pointerType = dynamic_cast< const ast::PointerType * >(
893 func->expr->result->stripReferences() );
894 if ( ! pointerType ) {
895 SemanticError( stmt->location, func->expr->result.get(),
896 "candidate not viable: not a pointer type\n" );
897 }
898
899 auto funcType = pointerType->base.as< ast::FunctionType >();
900 if ( ! funcType ) {
901 SemanticError( stmt->location, func->expr->result.get(),
902 "candidate not viable: not a function type\n" );
903 }
904
905 {
906 auto param = funcType->params.begin();
907 auto paramEnd = funcType->params.end();
908
909 if( ! nextMutex( param, paramEnd ) ) {
910 SemanticError( stmt->location, funcType,
911 "candidate function not viable: no mutex parameters\n");
912 }
913 }
914
915 CandidateRef func2{ new Candidate{ *func } };
916 // strip reference from function
917 func2->expr = referenceToRvalueConversion( func->expr, func2->cost );
918
919 // Each argument must be matched with a parameter of the current candidate
920 for ( auto & argsList : possibilities ) {
921 try {
922 // Declare data structures needed for resolution
923 ast::OpenVarSet open;
924 ast::AssertionSet need, have;
925 ast::TypeEnvironment resultEnv{ func->env };
926 // Add all type variables as open so that those not used in the
927 // parameter list are still considered open
928 resultEnv.add( funcType->forall );
929
930 // load type variables from arguments into one shared space
931 for ( auto & arg : argsList ) {
932 resultEnv.simpleCombine( arg->env );
933 }
934
935 // Make sure we don't widen any existing bindings
936 resultEnv.forbidWidening();
937
938 // Find any unbound type variables
939 resultEnv.extractOpenVars( open );
940
941 auto param = funcType->params.begin();
942 auto paramEnd = funcType->params.end();
943
944 unsigned n_mutex_param = 0;
945
946 // For every argument of its set, check if it matches one of the
947 // parameters. The order is important
948 for ( auto & arg : argsList ) {
949 // Ignore non-mutex arguments
950 if ( ! nextMutex( param, paramEnd ) ) {
951 // We ran out of parameters but still have arguments.
952 // This function doesn't match
953 SemanticError( stmt->location, funcType,
954 toString("candidate function not viable: too many mutex "
955 "arguments, expected ", n_mutex_param, "\n" ) );
956 }
957
958 ++n_mutex_param;
959
960 // Check if the argument matches the parameter type in the current
961 // scope
962 // ast::ptr< ast::Type > paramType = (*param)->get_type();
963 if (
964 ! unify(
965 arg->expr->result, *param, resultEnv, need, have, open )
966 ) {
967 // Type doesn't match
968 stringstream ss;
969 ss << "candidate function not viable: no known conversion "
970 "from '";
971 ast::print( ss, *param );
972 ss << "' to '";
973 ast::print( ss, arg->expr->result );
974 ss << "' with env '";
975 ast::print( ss, resultEnv );
976 ss << "'\n";
977 SemanticError( stmt->location, funcType, ss.str() );
978 }
979
980 ++param;
981 }
982
983 // All arguments match!
984
985 // Check if parameters are missing
986 if ( nextMutex( param, paramEnd ) ) {
987 do {
988 ++n_mutex_param;
989 ++param;
990 } while ( nextMutex( param, paramEnd ) );
991
992 // We ran out of arguments but still have parameters left; this
993 // function doesn't match
994 SemanticError( stmt->location, funcType,
995 toString( "candidate function not viable: too few mutex "
996 "arguments, expected ", n_mutex_param, "\n" ) );
997 }
998
999 // All parameters match!
1000
1001 // Finish the expressions to tie in proper environments
1002 finishExpr( func2->expr, resultEnv );
1003 for ( CandidateRef & arg : argsList ) {
1004 finishExpr( arg->expr, resultEnv );
1005 }
1006
1007 // This is a match, store it and save it for later
1008 funcCandidates.emplace_back( std::move( func2 ) );
1009 argsCandidates.emplace_back( std::move( argsList ) );
1010
1011 } catch ( SemanticErrorException & e ) {
1012 errors.append( e );
1013 }
1014 }
1015 } catch ( SemanticErrorException & e ) {
1016 errors.append( e );
1017 }
1018 }
1019
1020 // Make sure correct number of arguments
1021 if( funcCandidates.empty() ) {
1022 SemanticErrorException top( stmt->location,
1023 "No alternatives for function in call to waitfor" );
1024 top.append( errors );
1025 throw top;
1026 }
1027
1028 if( argsCandidates.empty() ) {
1029 SemanticErrorException top( stmt->location,
1030 "No alternatives for arguments in call to waitfor" );
1031 top.append( errors );
1032 throw top;
1033 }
1034
1035 if( funcCandidates.size() > 1 ) {
1036 SemanticErrorException top( stmt->location,
1037 "Ambiguous function in call to waitfor" );
1038 top.append( errors );
1039 throw top;
1040 }
1041 if( argsCandidates.size() > 1 ) {
1042 SemanticErrorException top( stmt->location,
1043 "Ambiguous arguments in call to waitfor" );
1044 top.append( errors );
1045 throw top;
1046 }
1047 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
1048
1049 // build new clause
1050 auto clause2 = new ast::WaitForClause( clause.location );
1051
1052 clause2->target = funcCandidates.front()->expr;
1053
1054 clause2->target_args.reserve( clause.target_args.size() );
1055 const ast::StructDecl * decl_monitor = symtab.lookupStruct( "monitor$" );
1056 for ( auto arg : argsCandidates.front() ) {
1057 const auto & loc = stmt->location;
1058
1059 ast::Expr * init = new ast::CastExpr( loc,
1060 new ast::UntypedExpr( loc,
1061 new ast::NameExpr( loc, "get_monitor" ),
1062 { arg->expr }
1063 ),
1064 new ast::PointerType(
1065 new ast::StructInstType(
1066 decl_monitor
1067 )
1068 )
1069 );
1070
1071 clause2->target_args.emplace_back( findSingleExpression( init, context ) );
1072 }
1073
1074 // Resolve the conditions as if it were an IfStmt, statements normally
1075 clause2->when_cond = findSingleExpression( clause.when_cond, context );
1076 clause2->stmt = clause.stmt->accept( *visitor );
1077
1078 // set results into stmt
1079 auto n = mutate( stmt );
1080 n->clauses[i] = clause2;
1081 stmt = n;
1082 }
1083
1084 if ( stmt->timeout_stmt ) {
1085 // resolve the timeout as a size_t, the conditions like IfStmt, and stmts normally
1086 ast::ptr< ast::Type > target =
1087 new ast::BasicType{ ast::BasicType::LongLongUnsignedInt };
1088 auto timeout_time = findSingleExpression( stmt->timeout_time, target, context );
1089 auto timeout_cond = findSingleExpression( stmt->timeout_cond, context );
1090 auto timeout_stmt = stmt->timeout_stmt->accept( *visitor );
1091
1092 // set results into stmt
1093 auto n = mutate( stmt );
1094 n->timeout_time = std::move( timeout_time );
1095 n->timeout_cond = std::move( timeout_cond );
1096 n->timeout_stmt = std::move( timeout_stmt );
1097 stmt = n;
1098 }
1099
1100 if ( stmt->else_stmt ) {
1101 // resolve the condition like IfStmt, stmts normally
1102 auto else_cond = findSingleExpression( stmt->else_cond, context );
1103 auto else_stmt = stmt->else_stmt->accept( *visitor );
1104
1105 // set results into stmt
1106 auto n = mutate( stmt );
1107 n->else_cond = std::move( else_cond );
1108 n->else_stmt = std::move( else_stmt );
1109 stmt = n;
1110 }
1111
1112 return stmt;
1113 }
1114
1115 const ast::WithStmt * Resolver::previsit( const ast::WithStmt * withStmt ) {
1116 auto mutStmt = mutate(withStmt);
1117 resolveWithExprs(mutStmt->exprs, stmtsToAddBefore);
1118 return mutStmt;
1119 }
1120
1121 void Resolver::resolveWithExprs(std::vector<ast::ptr<ast::Expr>> & exprs, std::list<ast::ptr<ast::Stmt>> & stmtsToAdd) {
1122 for (auto & expr : exprs) {
1123 // only struct- and union-typed expressions are viable candidates
1124 expr = findKindExpression( expr, context, structOrUnion, "with expression" );
1125
1126 // if with expression might be impure, create a temporary so that it is evaluated once
1127 if ( Tuples::maybeImpure( expr ) ) {
1128 static UniqueName tmpNamer( "_with_tmp_" );
1129 const CodeLocation loc = expr->location;
1130 auto tmp = new ast::ObjectDecl(loc, tmpNamer.newName(), expr->result, new ast::SingleInit(loc, expr ) );
1131 expr = new ast::VariableExpr( loc, tmp );
1132 stmtsToAdd.push_back( new ast::DeclStmt(loc, tmp ) );
1133 if ( InitTweak::isConstructable( tmp->type ) ) {
1134 // generate ctor/dtor and resolve them
1135 tmp->init = InitTweak::genCtorInit( loc, tmp );
1136 }
1137 // since tmp is freshly created, this should modify tmp in-place
1138 tmp->accept( *visitor );
1139 }
1140 else if (expr->env && expr->env->empty()) {
1141 expr = ast::mutate_field(expr.get(), &ast::Expr::env, nullptr);
1142 }
1143 }
1144 }
1145
1146
1147 const ast::SingleInit * Resolver::previsit( const ast::SingleInit * singleInit ) {
1148 visit_children = false;
1149 // resolve initialization using the possibilities as determined by the `currentObject`
1150 // cursor.
1151 ast::ptr< ast::Expr > untyped = new ast::UntypedInitExpr{
1152 singleInit->location, singleInit->value, currentObject.getOptions() };
1153 ast::ptr<ast::Expr> newExpr = findSingleExpression( untyped, context );
1154 const ast::InitExpr * initExpr = newExpr.strict_as< ast::InitExpr >();
1155
1156 // move cursor to the object that is actually initialized
1157 currentObject.setNext( initExpr->designation );
1158
1159 // discard InitExpr wrapper and retain relevant pieces.
1160 // `initExpr` may have inferred params in the case where the expression specialized a
1161 // function pointer, and newExpr may already have inferParams of its own, so a simple
1162 // swap is not sufficient
1163 ast::Expr::InferUnion inferred = initExpr->inferred;
1164 swap_and_save_env( newExpr, initExpr->expr );
1165 newExpr.get_and_mutate()->inferred.splice( std::move(inferred) );
1166
1167 // get the actual object's type (may not exactly match what comes back from the resolver
1168 // due to conversions)
1169 const ast::Type * initContext = currentObject.getCurrentType();
1170
1171 removeExtraneousCast( newExpr );
1172
1173 // check if actual object's type is char[]
1174 if ( auto at = dynamic_cast< const ast::ArrayType * >( initContext ) ) {
1175 if ( isCharType( at->base ) ) {
1176 // check if the resolved type is char*
1177 if ( auto pt = newExpr->result.as< ast::PointerType >() ) {
1178 if ( isCharType( pt->base ) ) {
1179 // strip cast if we're initializing a char[] with a char*
1180 // e.g. char x[] = "hello"
1181 if ( auto ce = newExpr.as< ast::CastExpr >() ) {
1182 swap_and_save_env( newExpr, ce->arg );
1183 }
1184 }
1185 }
1186 }
1187 }
1188
1189 // move cursor to next object in preparation for next initializer
1190 currentObject.increment();
1191
1192 // set initializer expression to resolved expression
1193 return ast::mutate_field( singleInit, &ast::SingleInit::value, std::move(newExpr) );
1194 }
1195
1196 const ast::ListInit * Resolver::previsit( const ast::ListInit * listInit ) {
1197 // move cursor into brace-enclosed initializer-list
1198 currentObject.enterListInit( listInit->location );
1199
1200 assert( listInit->designations.size() == listInit->initializers.size() );
1201 for ( unsigned i = 0; i < listInit->designations.size(); ++i ) {
1202 // iterate designations and initializers in pairs, moving the cursor to the current
1203 // designated object and resolving the initializer against that object
1204 listInit = ast::mutate_field_index(
1205 listInit, &ast::ListInit::designations, i,
1206 currentObject.findNext( listInit->designations[i] ) );
1207 listInit = ast::mutate_field_index(
1208 listInit, &ast::ListInit::initializers, i,
1209 listInit->initializers[i]->accept( *visitor ) );
1210 }
1211
1212 // move cursor out of brace-enclosed initializer-list
1213 currentObject.exitListInit();
1214
1215 visit_children = false;
1216 return listInit;
1217 }
1218
1219 const ast::ConstructorInit * Resolver::previsit( const ast::ConstructorInit * ctorInit ) {
1220 visitor->maybe_accept( ctorInit, &ast::ConstructorInit::ctor );
1221 visitor->maybe_accept( ctorInit, &ast::ConstructorInit::dtor );
1222
1223 // found a constructor - can get rid of C-style initializer
1224 // xxx - Rob suggests this field is dead code
1225 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::init, nullptr );
1226
1227 // intrinsic single-parameter constructors and destructors do nothing. Since this was
1228 // implicitly generated, there's no way for it to have side effects, so get rid of it to
1229 // clean up generated code
1230 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
1231 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::ctor, nullptr );
1232 }
1233 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
1234 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::dtor, nullptr );
1235 }
1236
1237 return ctorInit;
1238 }
1239
1240 // suppress error on autogen functions and mark invalid autogen as deleted.
1241 bool Resolver::on_error(ast::ptr<ast::Decl> & decl) {
1242 if (auto functionDecl = decl.as<ast::FunctionDecl>()) {
1243 // xxx - can intrinsic gen ever fail?
1244 if (functionDecl->linkage == ast::Linkage::AutoGen) {
1245 auto mutDecl = mutate(functionDecl);
1246 mutDecl->isDeleted = true;
1247 mutDecl->stmts = nullptr;
1248 decl = mutDecl;
1249 return false;
1250 }
1251 }
1252 return true;
1253 }
1254
1255} // namespace ResolvExpr
1256
1257// Local Variables: //
1258// tab-width: 4 //
1259// mode: c++ //
1260// compile-command: "make install" //
1261// End: //
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