source: src/ResolvExpr/Resolver.cc@ d1551a5

Last change on this file since d1551a5 was 59c8dff, checked in by JiadaL <j82liang@…>, 20 months ago

Draft Implementation for enum position pesudo function (posE). EnumPosExpr is mostly irrelevant for now. It is used in development/code probing and will be removed later
  • Property mode set to 100644
File size: 45.0 KB
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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 : Peter A. Buhr
12// Last Modified On : Thu Dec 14 18:44:43 2023
13// Update Count : 251
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 const ast::EnumPosExpr * previsit( const ast::EnumPosExpr * );
423
424 void resolveWithExprs(std::vector<ast::ptr<ast::Expr>> & exprs, std::list<ast::ptr<ast::Stmt>> & stmtsToAdd);
425
426 void beginScope() { managedTypes.beginScope(); }
427 void endScope() { managedTypes.endScope(); }
428 bool on_error(ast::ptr<ast::Decl> & decl);
429 };
430 // size_t Resolver::traceId = Stats::Heap::new_stacktrace_id("Resolver");
431
432 InitTweak::ManagedTypes Resolver::managedTypes;
433
434 void resolve( ast::TranslationUnit& translationUnit ) {
435 ast::Pass< Resolver >::run( translationUnit, translationUnit.global );
436 }
437
438 ast::ptr< ast::Init > resolveCtorInit(
439 const ast::ConstructorInit * ctorInit, const ResolveContext & context
440 ) {
441 assert( ctorInit );
442 ast::Pass< Resolver > resolver( context );
443 return ctorInit->accept( resolver );
444 }
445
446 const ast::Expr * resolveStmtExpr(
447 const ast::StmtExpr * stmtExpr, const ResolveContext & context
448 ) {
449 assert( stmtExpr );
450 ast::Pass< Resolver > resolver( context );
451 auto ret = mutate(stmtExpr->accept(resolver));
452 strict_dynamic_cast< ast::StmtExpr * >( ret )->computeResult();
453 return ret;
454 }
455
456 namespace {
457 const ast::Attribute * handleAttribute(const CodeLocation & loc, const ast::Attribute * attr, const ResolveContext & context) {
458 std::string name = attr->normalizedName();
459 if (name == "constructor" || name == "destructor") {
460 if (attr->params.size() == 1) {
461 auto arg = attr->params.front();
462 auto resolved = ResolvExpr::findSingleExpression( arg, new ast::BasicType( ast::BasicType::LongLongSignedInt ), context );
463 auto result = eval(arg);
464
465 auto mutAttr = mutate(attr);
466 mutAttr->params.front() = resolved;
467 if (! result.hasKnownValue) {
468 SemanticWarning(loc, Warning::GccAttributes,
469 toCString( name, " priorities must be integers from 0 to 65535 inclusive: ", arg ) );
470 }
471 else {
472 auto priority = result.knownValue;
473 if (priority < 101) {
474 SemanticWarning(loc, Warning::GccAttributes,
475 toCString( name, " priorities from 0 to 100 are reserved for the implementation" ) );
476 } else if (priority < 201 && ! buildingLibrary()) {
477 SemanticWarning(loc, Warning::GccAttributes,
478 toCString( name, " priorities from 101 to 200 are reserved for the implementation" ) );
479 }
480 }
481 return mutAttr;
482 } else if (attr->params.size() > 1) {
483 SemanticWarning(loc, Warning::GccAttributes, toCString( "too many arguments to ", name, " attribute" ) );
484 } else {
485 SemanticWarning(loc, Warning::GccAttributes, toCString( "too few arguments to ", name, " attribute" ) );
486 }
487 }
488 return attr;
489 }
490 }
491
492 const ast::FunctionDecl * Resolver::previsit( const ast::FunctionDecl * functionDecl ) {
493 GuardValue( functionReturn );
494
495 assert (functionDecl->unique());
496 if (!functionDecl->has_body() && !functionDecl->withExprs.empty()) {
497 SemanticError(functionDecl->location, functionDecl, "Function without body has with declarations");
498 }
499
500 if (!functionDecl->isTypeFixed) {
501 auto mutDecl = mutate(functionDecl);
502 auto mutType = mutDecl->type.get_and_mutate();
503
504 for (auto & attr: mutDecl->attributes) {
505 attr = handleAttribute(mutDecl->location, attr, context );
506 }
507
508 // handle assertions
509
510 symtab.enterScope();
511 mutType->forall.clear();
512 mutType->assertions.clear();
513 for (auto & typeParam : mutDecl->type_params) {
514 symtab.addType(typeParam);
515 mutType->forall.emplace_back(new ast::TypeInstType(typeParam));
516 }
517 for (auto & asst : mutDecl->assertions) {
518 asst = fixObjectType(asst.strict_as<ast::ObjectDecl>(), context);
519 symtab.addId(asst);
520 mutType->assertions.emplace_back(new ast::VariableExpr(functionDecl->location, asst));
521 }
522
523 // temporarily adds params to symbol table.
524 // actual scoping rules for params and withexprs differ - see Pass::visit(FunctionDecl)
525
526 std::vector<ast::ptr<ast::Type>> paramTypes;
527 std::vector<ast::ptr<ast::Type>> returnTypes;
528
529 for (auto & param : mutDecl->params) {
530 param = fixObjectType(param.strict_as<ast::ObjectDecl>(), context);
531 symtab.addId(param);
532 paramTypes.emplace_back(param->get_type());
533 }
534 for (auto & ret : mutDecl->returns) {
535 ret = fixObjectType(ret.strict_as<ast::ObjectDecl>(), context);
536 returnTypes.emplace_back(ret->get_type());
537 }
538 // since function type in decl is just a view of param types, need to update that as well
539 mutType->params = std::move(paramTypes);
540 mutType->returns = std::move(returnTypes);
541
542 auto renamedType = strict_dynamic_cast<const ast::FunctionType *>(renameTyVars(mutType, RenameMode::GEN_EXPR_ID));
543
544 std::list<ast::ptr<ast::Stmt>> newStmts;
545 resolveWithExprs (mutDecl->withExprs, newStmts);
546
547 if (mutDecl->stmts) {
548 auto mutStmt = mutDecl->stmts.get_and_mutate();
549 mutStmt->kids.splice(mutStmt->kids.begin(), std::move(newStmts));
550 mutDecl->stmts = mutStmt;
551 }
552
553 symtab.leaveScope();
554
555 mutDecl->type = renamedType;
556 mutDecl->mangleName = Mangle::mangle(mutDecl);
557 mutDecl->isTypeFixed = true;
558 functionDecl = mutDecl;
559 }
560 managedTypes.handleDWT(functionDecl);
561
562 functionReturn = extractResultType( functionDecl->type );
563 return functionDecl;
564 }
565
566 const ast::FunctionDecl * Resolver::postvisit( const ast::FunctionDecl * functionDecl ) {
567 // default value expressions have an environment which shouldn't be there and trips up
568 // later passes.
569 assert( functionDecl->unique() );
570 ast::FunctionType * mutType = mutate( functionDecl->type.get() );
571
572 for ( unsigned i = 0 ; i < mutType->params.size() ; ++i ) {
573 if ( const ast::ObjectDecl * obj = mutType->params[i].as< ast::ObjectDecl >() ) {
574 if ( const ast::SingleInit * init = obj->init.as< ast::SingleInit >() ) {
575 if ( init->value->env == nullptr ) continue;
576 // clone initializer minus the initializer environment
577 auto mutParam = mutate( mutType->params[i].strict_as< ast::ObjectDecl >() );
578 auto mutInit = mutate( mutParam->init.strict_as< ast::SingleInit >() );
579 auto mutValue = mutate( mutInit->value.get() );
580
581 mutValue->env = nullptr;
582 mutInit->value = mutValue;
583 mutParam->init = mutInit;
584 mutType->params[i] = mutParam;
585
586 assert( ! mutType->params[i].strict_as< ast::ObjectDecl >()->init.strict_as< ast::SingleInit >()->value->env);
587 }
588 }
589 }
590 mutate_field(functionDecl, &ast::FunctionDecl::type, mutType);
591 return functionDecl;
592 }
593
594 const ast::ObjectDecl * Resolver::previsit( const ast::ObjectDecl * objectDecl ) {
595 // To handle initialization of routine pointers [e.g. int (*fp)(int) = foo()],
596 // class-variable `initContext` is changed multiple times because the LHS is analyzed
597 // twice. The second analysis changes `initContext` because a function type can contain
598 // object declarations in the return and parameter types. Therefore each value of
599 // `initContext` is retained so the type on the first analysis is preserved and used for
600 // selecting the RHS.
601 GuardValue( currentObject );
602
603 if ( inEnumDecl && dynamic_cast< const ast::EnumInstType * >( objectDecl->get_type() ) ) {
604 // enumerator initializers should not use the enum type to initialize, since the
605 // enum type is still incomplete at this point. Use `int` instead.
606
607 if ( auto enumBase = dynamic_cast< const ast::EnumInstType * >
608 ( objectDecl->get_type() )->base->base ) {
609 objectDecl = fixObjectType( objectDecl, context );
610 currentObject = ast::CurrentObject{
611 objectDecl->location,
612 enumBase
613 };
614 } else {
615 objectDecl = fixObjectType( objectDecl, context );
616 currentObject = ast::CurrentObject{
617 objectDecl->location, new ast::BasicType{ ast::BasicType::SignedInt } };
618 }
619
620 }
621 else {
622 if ( !objectDecl->isTypeFixed ) {
623 auto newDecl = fixObjectType(objectDecl, context);
624 auto mutDecl = mutate(newDecl);
625
626 // generate CtorInit wrapper when necessary.
627 // in certain cases, fixObjectType is called before reaching
628 // this object in visitor pass, thus disabling CtorInit codegen.
629 // this happens on aggregate members and function parameters.
630 if ( InitTweak::tryConstruct( mutDecl ) && ( managedTypes.isManaged( mutDecl ) || ((! isInFunction() || mutDecl->storage.is_static ) && ! InitTweak::isConstExpr( mutDecl->init ) ) ) ) {
631 // constructed objects cannot be designated
632 if ( InitTweak::isDesignated( mutDecl->init ) ) {
633 ast::Pass<ResolveDesignators> res( context );
634 maybe_accept( mutDecl->init.get(), res );
635 if ( !res.core.result ) {
636 SemanticError( mutDecl, "Cannot include designations in the initializer for a managed Object.\n"
637 "If this is really what you want, initialize with @=." );
638 }
639 }
640 // constructed objects should not have initializers nested too deeply
641 if ( ! InitTweak::checkInitDepth( mutDecl ) ) SemanticError( mutDecl, "Managed object's initializer is too deep " );
642
643 mutDecl->init = InitTweak::genCtorInit( mutDecl->location, mutDecl );
644 }
645
646 objectDecl = mutDecl;
647 }
648 currentObject = ast::CurrentObject{ objectDecl->location, objectDecl->get_type() };
649 }
650
651 return objectDecl;
652 }
653
654 void Resolver::previsit( const ast::AggregateDecl * _aggDecl ) {
655 auto aggDecl = mutate(_aggDecl);
656 assertf(aggDecl == _aggDecl, "type declarations must be unique");
657
658 for (auto & member: aggDecl->members) {
659 // nested type decls are hoisted already. no need to do anything
660 if (auto obj = member.as<ast::ObjectDecl>()) {
661 member = fixObjectType(obj, context);
662 }
663 }
664 }
665
666 void Resolver::previsit( const ast::StructDecl * structDecl ) {
667 previsit(static_cast<const ast::AggregateDecl *>(structDecl));
668 managedTypes.handleStruct(structDecl);
669 }
670
671 void Resolver::previsit( const ast::EnumDecl * ) {
672 // in case we decide to allow nested enums
673 GuardValue( inEnumDecl );
674 inEnumDecl = true;
675 // don't need to fix types for enum fields
676 }
677
678 const ast::StaticAssertDecl * Resolver::previsit(
679 const ast::StaticAssertDecl * assertDecl
680 ) {
681 return ast::mutate_field(
682 assertDecl, &ast::StaticAssertDecl::cond,
683 findIntegralExpression( assertDecl->cond, context ) );
684 }
685
686 template< typename PtrType >
687 const PtrType * handlePtrType( const PtrType * type, const ResolveContext & context ) {
688 if ( type->dimension ) {
689 const ast::Type * sizeType = context.global.sizeType.get();
690 ast::ptr< ast::Expr > dimension = findSingleExpression( type->dimension, sizeType, context );
691 assertf(dimension->env->empty(), "array dimension expr has nonempty env");
692 dimension.get_and_mutate()->env = nullptr;
693 ast::mutate_field( type, &PtrType::dimension, dimension );
694 }
695 return type;
696 }
697
698 const ast::ArrayType * Resolver::previsit( const ast::ArrayType * at ) {
699 return handlePtrType( at, context );
700 }
701
702 const ast::PointerType * Resolver::previsit( const ast::PointerType * pt ) {
703 return handlePtrType( pt, context );
704 }
705
706 const ast::ExprStmt * Resolver::previsit( const ast::ExprStmt * exprStmt ) {
707 visit_children = false;
708 assertf( exprStmt->expr, "ExprStmt has null expression in resolver" );
709
710 return ast::mutate_field(
711 exprStmt, &ast::ExprStmt::expr, findVoidExpression( exprStmt->expr, context ) );
712 }
713
714 const ast::AsmExpr * Resolver::previsit( const ast::AsmExpr * asmExpr ) {
715 visit_children = false;
716
717 asmExpr = ast::mutate_field(
718 asmExpr, &ast::AsmExpr::operand, findVoidExpression( asmExpr->operand, context ) );
719
720 return asmExpr;
721 }
722
723 const ast::AsmStmt * Resolver::previsit( const ast::AsmStmt * asmStmt ) {
724 visitor->maybe_accept( asmStmt, &ast::AsmStmt::input );
725 visitor->maybe_accept( asmStmt, &ast::AsmStmt::output );
726 visit_children = false;
727 return asmStmt;
728 }
729
730 const ast::IfStmt * Resolver::previsit( const ast::IfStmt * ifStmt ) {
731 return ast::mutate_field(
732 ifStmt, &ast::IfStmt::cond, findIntegralExpression( ifStmt->cond, context ) );
733 }
734
735 const ast::WhileDoStmt * Resolver::previsit( const ast::WhileDoStmt * whileDoStmt ) {
736 return ast::mutate_field(
737 whileDoStmt, &ast::WhileDoStmt::cond, findIntegralExpression( whileDoStmt->cond, context ) );
738 }
739
740 const ast::ForStmt * Resolver::previsit( const ast::ForStmt * forStmt ) {
741 if ( forStmt->cond ) {
742 forStmt = ast::mutate_field(
743 forStmt, &ast::ForStmt::cond, findIntegralExpression( forStmt->cond, context ) );
744 }
745
746 if ( forStmt->inc ) {
747 forStmt = ast::mutate_field(
748 forStmt, &ast::ForStmt::inc, findVoidExpression( forStmt->inc, context ) );
749 }
750
751 return forStmt;
752 }
753
754 const ast::SwitchStmt * Resolver::previsit( const ast::SwitchStmt * switchStmt ) {
755 GuardValue( currentObject );
756 switchStmt = ast::mutate_field(
757 switchStmt, &ast::SwitchStmt::cond,
758 findIntegralExpression( switchStmt->cond, context ) );
759 currentObject = ast::CurrentObject{ switchStmt->location, switchStmt->cond->result };
760 return switchStmt;
761 }
762
763 const ast::CaseClause * Resolver::previsit( const ast::CaseClause * caseStmt ) {
764 if ( caseStmt->cond ) {
765 std::deque< ast::InitAlternative > initAlts = currentObject.getOptions();
766 assertf( initAlts.size() == 1, "SwitchStmt did not correctly resolve an integral "
767 "expression." );
768
769 ast::ptr< ast::Expr > untyped =
770 new ast::CastExpr{ caseStmt->location, caseStmt->cond, initAlts.front().type };
771 ast::ptr< ast::Expr > newExpr = findSingleExpression( untyped, context );
772
773 // case condition cannot have a cast in C, so it must be removed here, regardless of
774 // whether it would perform a conversion.
775 if ( const ast::CastExpr * castExpr = newExpr.as< ast::CastExpr >() ) {
776 swap_and_save_env( newExpr, castExpr->arg );
777 }
778
779 caseStmt = ast::mutate_field( caseStmt, &ast::CaseClause::cond, newExpr );
780 }
781 return caseStmt;
782 }
783
784 const ast::BranchStmt * Resolver::previsit( const ast::BranchStmt * branchStmt ) {
785 visit_children = false;
786 // must resolve the argument of a computed goto
787 if ( branchStmt->kind == ast::BranchStmt::Goto && branchStmt->computedTarget ) {
788 // computed goto argument is void*
789 ast::ptr< ast::Type > target = new ast::PointerType{ new ast::VoidType{} };
790 branchStmt = ast::mutate_field(
791 branchStmt, &ast::BranchStmt::computedTarget,
792 findSingleExpression( branchStmt->computedTarget, target, context ) );
793 }
794 return branchStmt;
795 }
796
797 const ast::ReturnStmt * Resolver::previsit( const ast::ReturnStmt * returnStmt ) {
798 visit_children = false;
799 if ( returnStmt->expr ) {
800 returnStmt = ast::mutate_field(
801 returnStmt, &ast::ReturnStmt::expr,
802 findSingleExpression( returnStmt->expr, functionReturn, context ) );
803 }
804 return returnStmt;
805 }
806
807 const ast::ThrowStmt * Resolver::previsit( const ast::ThrowStmt * throwStmt ) {
808 visit_children = false;
809 if ( throwStmt->expr ) {
810 const ast::StructDecl * exceptionDecl =
811 symtab.lookupStruct( "__cfaehm_base_exception_t" );
812 assert( exceptionDecl );
813 ast::ptr< ast::Type > exceptType =
814 new ast::PointerType{ new ast::StructInstType{ exceptionDecl } };
815 throwStmt = ast::mutate_field(
816 throwStmt, &ast::ThrowStmt::expr,
817 findSingleExpression( throwStmt->expr, exceptType, context ) );
818 }
819 return throwStmt;
820 }
821
822 const ast::CatchClause * Resolver::previsit( const ast::CatchClause * catchClause ) {
823 // Until we are very sure this invarent (ifs that move between passes have then)
824 // holds, check it. This allows a check for when to decode the mangling.
825 if ( auto ifStmt = catchClause->body.as<ast::IfStmt>() ) {
826 assert( ifStmt->then );
827 }
828 // Encode the catchStmt so the condition can see the declaration.
829 if ( catchClause->cond ) {
830 ast::CatchClause * clause = mutate( catchClause );
831 clause->body = new ast::IfStmt( clause->location, clause->cond, nullptr, clause->body );
832 clause->cond = nullptr;
833 return clause;
834 }
835 return catchClause;
836 }
837
838 const ast::CatchClause * Resolver::postvisit( const ast::CatchClause * catchClause ) {
839 // Decode the catchStmt so everything is stored properly.
840 const ast::IfStmt * ifStmt = catchClause->body.as<ast::IfStmt>();
841 if ( nullptr != ifStmt && nullptr == ifStmt->then ) {
842 assert( ifStmt->cond );
843 assert( ifStmt->else_ );
844 ast::CatchClause * clause = ast::mutate( catchClause );
845 clause->cond = ifStmt->cond;
846 clause->body = ifStmt->else_;
847 // ifStmt should be implicately deleted here.
848 return clause;
849 }
850 return catchClause;
851 }
852
853 const ast::WaitForStmt * Resolver::previsit( const ast::WaitForStmt * stmt ) {
854 visit_children = false;
855
856 // Resolve all clauses first
857 for ( unsigned i = 0; i < stmt->clauses.size(); ++i ) {
858 const ast::WaitForClause & clause = *stmt->clauses[i];
859
860 ast::TypeEnvironment env;
861 CandidateFinder funcFinder( context, env );
862
863 // Find all candidates for a function in canonical form
864 funcFinder.find( clause.target, ResolveMode::withAdjustment() );
865
866 if ( funcFinder.candidates.empty() ) {
867 stringstream ss;
868 ss << "Use of undeclared indentifier '";
869 ss << clause.target.strict_as< ast::NameExpr >()->name;
870 ss << "' in call to waitfor";
871 SemanticError( stmt->location, ss.str() );
872 }
873
874 if ( clause.target_args.empty() ) {
875 SemanticError( stmt->location,
876 "Waitfor clause must have at least one mutex parameter");
877 }
878
879 // Find all alternatives for all arguments in canonical form
880 std::vector< CandidateFinder > argFinders =
881 funcFinder.findSubExprs( clause.target_args );
882
883 // List all combinations of arguments
884 std::vector< CandidateList > possibilities;
885 combos( argFinders.begin(), argFinders.end(), back_inserter( possibilities ) );
886
887 // For every possible function:
888 // * try matching the arguments to the parameters, not the other way around because
889 // more arguments than parameters
890 CandidateList funcCandidates;
891 std::vector< CandidateList > argsCandidates;
892 SemanticErrorException errors;
893 for ( CandidateRef & func : funcFinder.candidates ) {
894 try {
895 auto pointerType = dynamic_cast< const ast::PointerType * >(
896 func->expr->result->stripReferences() );
897 if ( ! pointerType ) {
898 SemanticError( stmt->location, func->expr->result.get(),
899 "candidate not viable: not a pointer type\n" );
900 }
901
902 auto funcType = pointerType->base.as< ast::FunctionType >();
903 if ( ! funcType ) {
904 SemanticError( stmt->location, func->expr->result.get(),
905 "candidate not viable: not a function type\n" );
906 }
907
908 {
909 auto param = funcType->params.begin();
910 auto paramEnd = funcType->params.end();
911
912 if( ! nextMutex( param, paramEnd ) ) {
913 SemanticError( stmt->location, funcType,
914 "candidate function not viable: no mutex parameters\n");
915 }
916 }
917
918 CandidateRef func2{ new Candidate{ *func } };
919 // strip reference from function
920 func2->expr = referenceToRvalueConversion( func->expr, func2->cost );
921
922 // Each argument must be matched with a parameter of the current candidate
923 for ( auto & argsList : possibilities ) {
924 try {
925 // Declare data structures needed for resolution
926 ast::OpenVarSet open;
927 ast::AssertionSet need, have;
928 ast::TypeEnvironment resultEnv{ func->env };
929 // Add all type variables as open so that those not used in the
930 // parameter list are still considered open
931 resultEnv.add( funcType->forall );
932
933 // load type variables from arguments into one shared space
934 for ( auto & arg : argsList ) {
935 resultEnv.simpleCombine( arg->env );
936 }
937
938 // Make sure we don't widen any existing bindings
939 resultEnv.forbidWidening();
940
941 // Find any unbound type variables
942 resultEnv.extractOpenVars( open );
943
944 auto param = funcType->params.begin();
945 auto paramEnd = funcType->params.end();
946
947 unsigned n_mutex_param = 0;
948
949 // For every argument of its set, check if it matches one of the
950 // parameters. The order is important
951 for ( auto & arg : argsList ) {
952 // Ignore non-mutex arguments
953 if ( ! nextMutex( param, paramEnd ) ) {
954 // We ran out of parameters but still have arguments.
955 // This function doesn't match
956 SemanticError( stmt->location, funcType,
957 toString("candidate function not viable: too many mutex "
958 "arguments, expected ", n_mutex_param, "\n" ) );
959 }
960
961 ++n_mutex_param;
962
963 // Check if the argument matches the parameter type in the current scope.
964 // ast::ptr< ast::Type > paramType = (*param)->get_type();
965
966 if (
967 ! unify(
968 arg->expr->result, *param, resultEnv, need, have, open )
969 ) {
970 // Type doesn't match
971 stringstream ss;
972 ss << "candidate function not viable: no known conversion "
973 "from '";
974 ast::print( ss, *param );
975 ss << "' to '";
976 ast::print( ss, arg->expr->result );
977 ss << "' with env '";
978 ast::print( ss, resultEnv );
979 ss << "'\n";
980 SemanticError( stmt->location, funcType, ss.str() );
981 }
982
983 ++param;
984 }
985
986 // All arguments match!
987
988 // Check if parameters are missing
989 if ( nextMutex( param, paramEnd ) ) {
990 do {
991 ++n_mutex_param;
992 ++param;
993 } while ( nextMutex( param, paramEnd ) );
994
995 // We ran out of arguments but still have parameters left; this
996 // function doesn't match
997 SemanticError( stmt->location, funcType,
998 toString( "candidate function not viable: too few mutex "
999 "arguments, expected ", n_mutex_param, "\n" ) );
1000 }
1001
1002 // All parameters match!
1003
1004 // Finish the expressions to tie in proper environments
1005 finishExpr( func2->expr, resultEnv );
1006 for ( CandidateRef & arg : argsList ) {
1007 finishExpr( arg->expr, resultEnv );
1008 }
1009
1010 // This is a match, store it and save it for later
1011 funcCandidates.emplace_back( std::move( func2 ) );
1012 argsCandidates.emplace_back( std::move( argsList ) );
1013
1014 } catch ( SemanticErrorException & e ) {
1015 errors.append( e );
1016 }
1017 }
1018 } catch ( SemanticErrorException & e ) {
1019 errors.append( e );
1020 }
1021 }
1022
1023 // Make sure correct number of arguments
1024 if( funcCandidates.empty() ) {
1025 SemanticErrorException top( stmt->location,
1026 "No alternatives for function in call to waitfor" );
1027 top.append( errors );
1028 throw top;
1029 }
1030
1031 if( argsCandidates.empty() ) {
1032 SemanticErrorException top( stmt->location,
1033 "No alternatives for arguments in call to waitfor" );
1034 top.append( errors );
1035 throw top;
1036 }
1037
1038 if( funcCandidates.size() > 1 ) {
1039 SemanticErrorException top( stmt->location,
1040 "Ambiguous function in call to waitfor" );
1041 top.append( errors );
1042 throw top;
1043 }
1044 if( argsCandidates.size() > 1 ) {
1045 SemanticErrorException top( stmt->location,
1046 "Ambiguous arguments in call to waitfor" );
1047 top.append( errors );
1048 throw top;
1049 }
1050 // TODO: need to use findDeletedExpr to ensure no deleted identifiers are used.
1051
1052 // build new clause
1053 auto clause2 = new ast::WaitForClause( clause.location );
1054
1055 clause2->target = funcCandidates.front()->expr;
1056
1057 clause2->target_args.reserve( clause.target_args.size() );
1058 const ast::StructDecl * decl_monitor = symtab.lookupStruct( "monitor$" );
1059 for ( auto arg : argsCandidates.front() ) {
1060 const auto & loc = stmt->location;
1061
1062 ast::Expr * init = new ast::CastExpr( loc,
1063 new ast::UntypedExpr( loc,
1064 new ast::NameExpr( loc, "get_monitor" ),
1065 { arg->expr }
1066 ),
1067 new ast::PointerType(
1068 new ast::StructInstType(
1069 decl_monitor
1070 )
1071 )
1072 );
1073
1074 clause2->target_args.emplace_back( findSingleExpression( init, context ) );
1075 }
1076
1077 // Resolve the conditions as if it were an IfStmt, statements normally
1078 clause2->when_cond = findSingleExpression( clause.when_cond, context );
1079 clause2->stmt = clause.stmt->accept( *visitor );
1080
1081 // set results into stmt
1082 auto n = mutate( stmt );
1083 n->clauses[i] = clause2;
1084 stmt = n;
1085 }
1086
1087 if ( stmt->timeout_stmt ) {
1088 // resolve the timeout as a size_t, the conditions like IfStmt, and stmts normally
1089 ast::ptr< ast::Type > target =
1090 new ast::BasicType{ ast::BasicType::LongLongUnsignedInt };
1091 auto timeout_time = findSingleExpression( stmt->timeout_time, target, context );
1092 auto timeout_cond = findSingleExpression( stmt->timeout_cond, context );
1093 auto timeout_stmt = stmt->timeout_stmt->accept( *visitor );
1094
1095 // set results into stmt
1096 auto n = mutate( stmt );
1097 n->timeout_time = std::move( timeout_time );
1098 n->timeout_cond = std::move( timeout_cond );
1099 n->timeout_stmt = std::move( timeout_stmt );
1100 stmt = n;
1101 }
1102
1103 if ( stmt->else_stmt ) {
1104 // resolve the condition like IfStmt, stmts normally
1105 auto else_cond = findSingleExpression( stmt->else_cond, context );
1106 auto else_stmt = stmt->else_stmt->accept( *visitor );
1107
1108 // set results into stmt
1109 auto n = mutate( stmt );
1110 n->else_cond = std::move( else_cond );
1111 n->else_stmt = std::move( else_stmt );
1112 stmt = n;
1113 }
1114
1115 return stmt;
1116 }
1117
1118 const ast::WithStmt * Resolver::previsit( const ast::WithStmt * withStmt ) {
1119 auto mutStmt = mutate(withStmt);
1120 resolveWithExprs(mutStmt->exprs, stmtsToAddBefore);
1121 return mutStmt;
1122 }
1123
1124 void Resolver::resolveWithExprs(std::vector<ast::ptr<ast::Expr>> & exprs, std::list<ast::ptr<ast::Stmt>> & stmtsToAdd) {
1125 for (auto & expr : exprs) {
1126 // only struct- and union-typed expressions are viable candidates
1127 expr = findKindExpression( expr, context, structOrUnion, "with expression" );
1128
1129 // if with expression might be impure, create a temporary so that it is evaluated once
1130 if ( Tuples::maybeImpure( expr ) ) {
1131 static UniqueName tmpNamer( "_with_tmp_" );
1132 const CodeLocation loc = expr->location;
1133 auto tmp = new ast::ObjectDecl(loc, tmpNamer.newName(), expr->result, new ast::SingleInit(loc, expr ) );
1134 expr = new ast::VariableExpr( loc, tmp );
1135 stmtsToAdd.push_back( new ast::DeclStmt(loc, tmp ) );
1136 if ( InitTweak::isConstructable( tmp->type ) ) {
1137 // generate ctor/dtor and resolve them
1138 tmp->init = InitTweak::genCtorInit( loc, tmp );
1139 }
1140 // since tmp is freshly created, this should modify tmp in-place
1141 tmp->accept( *visitor );
1142 }
1143 else if (expr->env && expr->env->empty()) {
1144 expr = ast::mutate_field(expr.get(), &ast::Expr::env, nullptr);
1145 }
1146 }
1147 }
1148
1149
1150 const ast::SingleInit * Resolver::previsit( const ast::SingleInit * singleInit ) {
1151 visit_children = false;
1152 // resolve initialization using the possibilities as determined by the `currentObject`
1153 // cursor.
1154 ast::ptr< ast::Expr > untyped = new ast::UntypedInitExpr{
1155 singleInit->location, singleInit->value, currentObject.getOptions() };
1156 ast::ptr<ast::Expr> newExpr = findSingleExpression( untyped, context );
1157 const ast::InitExpr * initExpr = newExpr.strict_as< ast::InitExpr >();
1158
1159 // move cursor to the object that is actually initialized
1160 currentObject.setNext( initExpr->designation );
1161
1162 // discard InitExpr wrapper and retain relevant pieces.
1163 // `initExpr` may have inferred params in the case where the expression specialized a
1164 // function pointer, and newExpr may already have inferParams of its own, so a simple
1165 // swap is not sufficient
1166 ast::Expr::InferUnion inferred = initExpr->inferred;
1167 swap_and_save_env( newExpr, initExpr->expr );
1168 newExpr.get_and_mutate()->inferred.splice( std::move(inferred) );
1169
1170 // get the actual object's type (may not exactly match what comes back from the resolver
1171 // due to conversions)
1172 const ast::Type * initContext = currentObject.getCurrentType();
1173
1174 removeExtraneousCast( newExpr );
1175
1176 // check if actual object's type is char[]
1177 if ( auto at = dynamic_cast< const ast::ArrayType * >( initContext ) ) {
1178 if ( isCharType( at->base ) ) {
1179 // check if the resolved type is char*
1180 if ( auto pt = newExpr->result.as< ast::PointerType >() ) {
1181 if ( isCharType( pt->base ) ) {
1182 // strip cast if we're initializing a char[] with a char*
1183 // e.g. char x[] = "hello"
1184 if ( auto ce = newExpr.as< ast::CastExpr >() ) {
1185 swap_and_save_env( newExpr, ce->arg );
1186 }
1187 }
1188 }
1189 }
1190 }
1191
1192 // move cursor to next object in preparation for next initializer
1193 currentObject.increment();
1194
1195 // set initializer expression to resolved expression
1196 return ast::mutate_field( singleInit, &ast::SingleInit::value, std::move(newExpr) );
1197 }
1198
1199 const ast::ListInit * Resolver::previsit( const ast::ListInit * listInit ) {
1200 // move cursor into brace-enclosed initializer-list
1201 currentObject.enterListInit( listInit->location );
1202
1203 assert( listInit->designations.size() == listInit->initializers.size() );
1204 for ( unsigned i = 0; i < listInit->designations.size(); ++i ) {
1205 // iterate designations and initializers in pairs, moving the cursor to the current
1206 // designated object and resolving the initializer against that object
1207 listInit = ast::mutate_field_index(
1208 listInit, &ast::ListInit::designations, i,
1209 currentObject.findNext( listInit->designations[i] ) );
1210 listInit = ast::mutate_field_index(
1211 listInit, &ast::ListInit::initializers, i,
1212 listInit->initializers[i]->accept( *visitor ) );
1213 }
1214
1215 // move cursor out of brace-enclosed initializer-list
1216 currentObject.exitListInit();
1217
1218 visit_children = false;
1219 return listInit;
1220 }
1221
1222 const ast::ConstructorInit * Resolver::previsit( const ast::ConstructorInit * ctorInit ) {
1223 visitor->maybe_accept( ctorInit, &ast::ConstructorInit::ctor );
1224 visitor->maybe_accept( ctorInit, &ast::ConstructorInit::dtor );
1225
1226 // found a constructor - can get rid of C-style initializer
1227 // xxx - Rob suggests this field is dead code
1228 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::init, nullptr );
1229
1230 // intrinsic single-parameter constructors and destructors do nothing. Since this was
1231 // implicitly generated, there's no way for it to have side effects, so get rid of it to
1232 // clean up generated code
1233 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->ctor ) ) {
1234 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::ctor, nullptr );
1235 }
1236 if ( InitTweak::isIntrinsicSingleArgCallStmt( ctorInit->dtor ) ) {
1237 ctorInit = ast::mutate_field( ctorInit, &ast::ConstructorInit::dtor, nullptr );
1238 }
1239
1240 return ctorInit;
1241 }
1242
1243 const ast::EnumPosExpr * Resolver::previsit( const ast::EnumPosExpr * enumPos ) {
1244 visitor->maybe_accept( enumPos, &ast::EnumPosExpr::expr );
1245 return enumPos;
1246 }
1247
1248 // suppress error on autogen functions and mark invalid autogen as deleted.
1249 bool Resolver::on_error(ast::ptr<ast::Decl> & decl) {
1250 if (auto functionDecl = decl.as<ast::FunctionDecl>()) {
1251 // xxx - can intrinsic gen ever fail?
1252 if (functionDecl->linkage == ast::Linkage::AutoGen) {
1253 auto mutDecl = mutate(functionDecl);
1254 mutDecl->isDeleted = true;
1255 mutDecl->stmts = nullptr;
1256 decl = mutDecl;
1257 return false;
1258 }
1259 }
1260 return true;
1261 }
1262
1263} // namespace ResolvExpr
1264
1265// Local Variables: //
1266// tab-width: 4 //
1267// mode: c++ //
1268// compile-command: "make install" //
1269// End: //
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