clang  14.0.0git
SemaLookup.cpp
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1 //===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements name lookup for C, C++, Objective-C, and
10 // Objective-C++.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/DeclLookups.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/DeclTemplate.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/Basic/Builtins.h"
26 #include "clang/Lex/HeaderSearch.h"
27 #include "clang/Lex/ModuleLoader.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Sema/DeclSpec.h"
30 #include "clang/Sema/Lookup.h"
31 #include "clang/Sema/Overload.h"
32 #include "clang/Sema/Scope.h"
33 #include "clang/Sema/ScopeInfo.h"
34 #include "clang/Sema/Sema.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/ADT/SmallPtrSet.h"
40 #include "llvm/ADT/TinyPtrVector.h"
41 #include "llvm/ADT/edit_distance.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include <algorithm>
44 #include <iterator>
45 #include <list>
46 #include <set>
47 #include <utility>
48 #include <vector>
49 
50 #include "OpenCLBuiltins.inc"
51 
52 using namespace clang;
53 using namespace sema;
54 
55 namespace {
56  class UnqualUsingEntry {
57  const DeclContext *Nominated;
58  const DeclContext *CommonAncestor;
59 
60  public:
61  UnqualUsingEntry(const DeclContext *Nominated,
62  const DeclContext *CommonAncestor)
63  : Nominated(Nominated), CommonAncestor(CommonAncestor) {
64  }
65 
66  const DeclContext *getCommonAncestor() const {
67  return CommonAncestor;
68  }
69 
70  const DeclContext *getNominatedNamespace() const {
71  return Nominated;
72  }
73 
74  // Sort by the pointer value of the common ancestor.
75  struct Comparator {
76  bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
77  return L.getCommonAncestor() < R.getCommonAncestor();
78  }
79 
80  bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
81  return E.getCommonAncestor() < DC;
82  }
83 
84  bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
85  return DC < E.getCommonAncestor();
86  }
87  };
88  };
89 
90  /// A collection of using directives, as used by C++ unqualified
91  /// lookup.
92  class UnqualUsingDirectiveSet {
93  Sema &SemaRef;
94 
95  typedef SmallVector<UnqualUsingEntry, 8> ListTy;
96 
97  ListTy list;
99 
100  public:
101  UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {}
102 
103  void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
104  // C++ [namespace.udir]p1:
105  // During unqualified name lookup, the names appear as if they
106  // were declared in the nearest enclosing namespace which contains
107  // both the using-directive and the nominated namespace.
108  DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
109  assert(InnermostFileDC && InnermostFileDC->isFileContext());
110 
111  for (; S; S = S->getParent()) {
112  // C++ [namespace.udir]p1:
113  // A using-directive shall not appear in class scope, but may
114  // appear in namespace scope or in block scope.
115  DeclContext *Ctx = S->getEntity();
116  if (Ctx && Ctx->isFileContext()) {
117  visit(Ctx, Ctx);
118  } else if (!Ctx || Ctx->isFunctionOrMethod()) {
119  for (auto *I : S->using_directives())
120  if (SemaRef.isVisible(I))
121  visit(I, InnermostFileDC);
122  }
123  }
124  }
125 
126  // Visits a context and collect all of its using directives
127  // recursively. Treats all using directives as if they were
128  // declared in the context.
129  //
130  // A given context is only every visited once, so it is important
131  // that contexts be visited from the inside out in order to get
132  // the effective DCs right.
133  void visit(DeclContext *DC, DeclContext *EffectiveDC) {
134  if (!visited.insert(DC).second)
135  return;
136 
137  addUsingDirectives(DC, EffectiveDC);
138  }
139 
140  // Visits a using directive and collects all of its using
141  // directives recursively. Treats all using directives as if they
142  // were declared in the effective DC.
143  void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
145  if (!visited.insert(NS).second)
146  return;
147 
148  addUsingDirective(UD, EffectiveDC);
149  addUsingDirectives(NS, EffectiveDC);
150  }
151 
152  // Adds all the using directives in a context (and those nominated
153  // by its using directives, transitively) as if they appeared in
154  // the given effective context.
155  void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
157  while (true) {
158  for (auto UD : DC->using_directives()) {
160  if (SemaRef.isVisible(UD) && visited.insert(NS).second) {
161  addUsingDirective(UD, EffectiveDC);
162  queue.push_back(NS);
163  }
164  }
165 
166  if (queue.empty())
167  return;
168 
169  DC = queue.pop_back_val();
170  }
171  }
172 
173  // Add a using directive as if it had been declared in the given
174  // context. This helps implement C++ [namespace.udir]p3:
175  // The using-directive is transitive: if a scope contains a
176  // using-directive that nominates a second namespace that itself
177  // contains using-directives, the effect is as if the
178  // using-directives from the second namespace also appeared in
179  // the first.
180  void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
181  // Find the common ancestor between the effective context and
182  // the nominated namespace.
183  DeclContext *Common = UD->getNominatedNamespace();
184  while (!Common->Encloses(EffectiveDC))
185  Common = Common->getParent();
186  Common = Common->getPrimaryContext();
187 
188  list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
189  }
190 
191  void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); }
192 
193  typedef ListTy::const_iterator const_iterator;
194 
195  const_iterator begin() const { return list.begin(); }
196  const_iterator end() const { return list.end(); }
197 
198  llvm::iterator_range<const_iterator>
199  getNamespacesFor(DeclContext *DC) const {
200  return llvm::make_range(std::equal_range(begin(), end(),
201  DC->getPrimaryContext(),
202  UnqualUsingEntry::Comparator()));
203  }
204  };
205 } // end anonymous namespace
206 
207 // Retrieve the set of identifier namespaces that correspond to a
208 // specific kind of name lookup.
209 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
210  bool CPlusPlus,
211  bool Redeclaration) {
212  unsigned IDNS = 0;
213  switch (NameKind) {
219  IDNS = Decl::IDNS_Ordinary;
220  if (CPlusPlus) {
222  if (Redeclaration)
224  }
225  if (Redeclaration)
226  IDNS |= Decl::IDNS_LocalExtern;
227  break;
228 
230  // Operator lookup is its own crazy thing; it is not the same
231  // as (e.g.) looking up an operator name for redeclaration.
232  assert(!Redeclaration && "cannot do redeclaration operator lookup");
234  break;
235 
236  case Sema::LookupTagName:
237  if (CPlusPlus) {
238  IDNS = Decl::IDNS_Type;
239 
240  // When looking for a redeclaration of a tag name, we add:
241  // 1) TagFriend to find undeclared friend decls
242  // 2) Namespace because they can't "overload" with tag decls.
243  // 3) Tag because it includes class templates, which can't
244  // "overload" with tag decls.
245  if (Redeclaration)
247  } else {
248  IDNS = Decl::IDNS_Tag;
249  }
250  break;
251 
252  case Sema::LookupLabel:
253  IDNS = Decl::IDNS_Label;
254  break;
255 
257  IDNS = Decl::IDNS_Member;
258  if (CPlusPlus)
260  break;
261 
264  break;
265 
267  IDNS = Decl::IDNS_Namespace;
268  break;
269 
271  assert(Redeclaration && "should only be used for redecl lookup");
275  break;
276 
279  break;
280 
283  break;
284 
286  IDNS = Decl::IDNS_OMPMapper;
287  break;
288 
289  case Sema::LookupAnyName:
292  | Decl::IDNS_Type;
293  break;
294  }
295  return IDNS;
296 }
297 
298 void LookupResult::configure() {
299  IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
300  isForRedeclaration());
301 
302  // If we're looking for one of the allocation or deallocation
303  // operators, make sure that the implicitly-declared new and delete
304  // operators can be found.
305  switch (NameInfo.getName().getCXXOverloadedOperator()) {
306  case OO_New:
307  case OO_Delete:
308  case OO_Array_New:
309  case OO_Array_Delete:
310  getSema().DeclareGlobalNewDelete();
311  break;
312 
313  default:
314  break;
315  }
316 
317  // Compiler builtins are always visible, regardless of where they end
318  // up being declared.
319  if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
320  if (unsigned BuiltinID = Id->getBuiltinID()) {
321  if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
322  AllowHidden = true;
323  }
324  }
325 }
326 
327 bool LookupResult::sanity() const {
328  // This function is never called by NDEBUG builds.
329  assert(ResultKind != NotFound || Decls.size() == 0);
330  assert(ResultKind != Found || Decls.size() == 1);
331  assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
332  (Decls.size() == 1 &&
333  isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
334  assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
335  assert(ResultKind != Ambiguous || Decls.size() > 1 ||
336  (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
337  Ambiguity == AmbiguousBaseSubobjectTypes)));
338  assert((Paths != nullptr) == (ResultKind == Ambiguous &&
339  (Ambiguity == AmbiguousBaseSubobjectTypes ||
340  Ambiguity == AmbiguousBaseSubobjects)));
341  return true;
342 }
343 
344 // Necessary because CXXBasePaths is not complete in Sema.h
345 void LookupResult::deletePaths(CXXBasePaths *Paths) {
346  delete Paths;
347 }
348 
349 /// Get a representative context for a declaration such that two declarations
350 /// will have the same context if they were found within the same scope.
352  // For function-local declarations, use that function as the context. This
353  // doesn't account for scopes within the function; the caller must deal with
354  // those.
356  if (DC->isFunctionOrMethod())
357  return DC;
358 
359  // Otherwise, look at the semantic context of the declaration. The
360  // declaration must have been found there.
361  return D->getDeclContext()->getRedeclContext();
362 }
363 
364 /// Determine whether \p D is a better lookup result than \p Existing,
365 /// given that they declare the same entity.
367  NamedDecl *D, NamedDecl *Existing) {
368  // When looking up redeclarations of a using declaration, prefer a using
369  // shadow declaration over any other declaration of the same entity.
370  if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
371  !isa<UsingShadowDecl>(Existing))
372  return true;
373 
374  auto *DUnderlying = D->getUnderlyingDecl();
375  auto *EUnderlying = Existing->getUnderlyingDecl();
376 
377  // If they have different underlying declarations, prefer a typedef over the
378  // original type (this happens when two type declarations denote the same
379  // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
380  // might carry additional semantic information, such as an alignment override.
381  // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
382  // declaration over a typedef. Also prefer a tag over a typedef for
383  // destructor name lookup because in some contexts we only accept a
384  // class-name in a destructor declaration.
385  if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
386  assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
387  bool HaveTag = isa<TagDecl>(EUnderlying);
388  bool WantTag =
390  return HaveTag != WantTag;
391  }
392 
393  // Pick the function with more default arguments.
394  // FIXME: In the presence of ambiguous default arguments, we should keep both,
395  // so we can diagnose the ambiguity if the default argument is needed.
396  // See C++ [over.match.best]p3.
397  if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
398  auto *EFD = cast<FunctionDecl>(EUnderlying);
399  unsigned DMin = DFD->getMinRequiredArguments();
400  unsigned EMin = EFD->getMinRequiredArguments();
401  // If D has more default arguments, it is preferred.
402  if (DMin != EMin)
403  return DMin < EMin;
404  // FIXME: When we track visibility for default function arguments, check
405  // that we pick the declaration with more visible default arguments.
406  }
407 
408  // Pick the template with more default template arguments.
409  if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
410  auto *ETD = cast<TemplateDecl>(EUnderlying);
411  unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
412  unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
413  // If D has more default arguments, it is preferred. Note that default
414  // arguments (and their visibility) is monotonically increasing across the
415  // redeclaration chain, so this is a quick proxy for "is more recent".
416  if (DMin != EMin)
417  return DMin < EMin;
418  // If D has more *visible* default arguments, it is preferred. Note, an
419  // earlier default argument being visible does not imply that a later
420  // default argument is visible, so we can't just check the first one.
421  for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
422  I != N; ++I) {
424  ETD->getTemplateParameters()->getParam(I)) &&
426  DTD->getTemplateParameters()->getParam(I)))
427  return true;
428  }
429  }
430 
431  // VarDecl can have incomplete array types, prefer the one with more complete
432  // array type.
433  if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
434  VarDecl *EVD = cast<VarDecl>(EUnderlying);
435  if (EVD->getType()->isIncompleteType() &&
436  !DVD->getType()->isIncompleteType()) {
437  // Prefer the decl with a more complete type if visible.
438  return S.isVisible(DVD);
439  }
440  return false; // Avoid picking up a newer decl, just because it was newer.
441  }
442 
443  // For most kinds of declaration, it doesn't really matter which one we pick.
444  if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
445  // If the existing declaration is hidden, prefer the new one. Otherwise,
446  // keep what we've got.
447  return !S.isVisible(Existing);
448  }
449 
450  // Pick the newer declaration; it might have a more precise type.
451  for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
452  Prev = Prev->getPreviousDecl())
453  if (Prev == EUnderlying)
454  return true;
455  return false;
456 }
457 
458 /// Determine whether \p D can hide a tag declaration.
459 static bool canHideTag(NamedDecl *D) {
460  // C++ [basic.scope.declarative]p4:
461  // Given a set of declarations in a single declarative region [...]
462  // exactly one declaration shall declare a class name or enumeration name
463  // that is not a typedef name and the other declarations shall all refer to
464  // the same variable, non-static data member, or enumerator, or all refer
465  // to functions and function templates; in this case the class name or
466  // enumeration name is hidden.
467  // C++ [basic.scope.hiding]p2:
468  // A class name or enumeration name can be hidden by the name of a
469  // variable, data member, function, or enumerator declared in the same
470  // scope.
471  // An UnresolvedUsingValueDecl always instantiates to one of these.
472  D = D->getUnderlyingDecl();
473  return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
474  isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
475  isa<UnresolvedUsingValueDecl>(D);
476 }
477 
478 /// Resolves the result kind of this lookup.
480  unsigned N = Decls.size();
481 
482  // Fast case: no possible ambiguity.
483  if (N == 0) {
484  assert(ResultKind == NotFound ||
485  ResultKind == NotFoundInCurrentInstantiation);
486  return;
487  }
488 
489  // If there's a single decl, we need to examine it to decide what
490  // kind of lookup this is.
491  if (N == 1) {
492  NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
493  if (isa<FunctionTemplateDecl>(D))
494  ResultKind = FoundOverloaded;
495  else if (isa<UnresolvedUsingValueDecl>(D))
496  ResultKind = FoundUnresolvedValue;
497  return;
498  }
499 
500  // Don't do any extra resolution if we've already resolved as ambiguous.
501  if (ResultKind == Ambiguous) return;
502 
503  llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
504  llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
505 
506  bool Ambiguous = false;
507  bool HasTag = false, HasFunction = false;
508  bool HasFunctionTemplate = false, HasUnresolved = false;
509  NamedDecl *HasNonFunction = nullptr;
510 
511  llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
512 
513  unsigned UniqueTagIndex = 0;
514 
515  unsigned I = 0;
516  while (I < N) {
517  NamedDecl *D = Decls[I]->getUnderlyingDecl();
518  D = cast<NamedDecl>(D->getCanonicalDecl());
519 
520  // Ignore an invalid declaration unless it's the only one left.
521  if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
522  Decls[I] = Decls[--N];
523  continue;
524  }
525 
526  llvm::Optional<unsigned> ExistingI;
527 
528  // Redeclarations of types via typedef can occur both within a scope
529  // and, through using declarations and directives, across scopes. There is
530  // no ambiguity if they all refer to the same type, so unique based on the
531  // canonical type.
532  if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
533  QualType T = getSema().Context.getTypeDeclType(TD);
534  auto UniqueResult = UniqueTypes.insert(
535  std::make_pair(getSema().Context.getCanonicalType(T), I));
536  if (!UniqueResult.second) {
537  // The type is not unique.
538  ExistingI = UniqueResult.first->second;
539  }
540  }
541 
542  // For non-type declarations, check for a prior lookup result naming this
543  // canonical declaration.
544  if (!ExistingI) {
545  auto UniqueResult = Unique.insert(std::make_pair(D, I));
546  if (!UniqueResult.second) {
547  // We've seen this entity before.
548  ExistingI = UniqueResult.first->second;
549  }
550  }
551 
552  if (ExistingI) {
553  // This is not a unique lookup result. Pick one of the results and
554  // discard the other.
555  if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
556  Decls[*ExistingI]))
557  Decls[*ExistingI] = Decls[I];
558  Decls[I] = Decls[--N];
559  continue;
560  }
561 
562  // Otherwise, do some decl type analysis and then continue.
563 
564  if (isa<UnresolvedUsingValueDecl>(D)) {
565  HasUnresolved = true;
566  } else if (isa<TagDecl>(D)) {
567  if (HasTag)
568  Ambiguous = true;
569  UniqueTagIndex = I;
570  HasTag = true;
571  } else if (isa<FunctionTemplateDecl>(D)) {
572  HasFunction = true;
573  HasFunctionTemplate = true;
574  } else if (isa<FunctionDecl>(D)) {
575  HasFunction = true;
576  } else {
577  if (HasNonFunction) {
578  // If we're about to create an ambiguity between two declarations that
579  // are equivalent, but one is an internal linkage declaration from one
580  // module and the other is an internal linkage declaration from another
581  // module, just skip it.
582  if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
583  D)) {
584  EquivalentNonFunctions.push_back(D);
585  Decls[I] = Decls[--N];
586  continue;
587  }
588 
589  Ambiguous = true;
590  }
591  HasNonFunction = D;
592  }
593  I++;
594  }
595 
596  // C++ [basic.scope.hiding]p2:
597  // A class name or enumeration name can be hidden by the name of
598  // an object, function, or enumerator declared in the same
599  // scope. If a class or enumeration name and an object, function,
600  // or enumerator are declared in the same scope (in any order)
601  // with the same name, the class or enumeration name is hidden
602  // wherever the object, function, or enumerator name is visible.
603  // But it's still an error if there are distinct tag types found,
604  // even if they're not visible. (ref?)
605  if (N > 1 && HideTags && HasTag && !Ambiguous &&
606  (HasFunction || HasNonFunction || HasUnresolved)) {
607  NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
608  if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
609  getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
610  getContextForScopeMatching(OtherDecl)) &&
611  canHideTag(OtherDecl))
612  Decls[UniqueTagIndex] = Decls[--N];
613  else
614  Ambiguous = true;
615  }
616 
617  // FIXME: This diagnostic should really be delayed until we're done with
618  // the lookup result, in case the ambiguity is resolved by the caller.
619  if (!EquivalentNonFunctions.empty() && !Ambiguous)
620  getSema().diagnoseEquivalentInternalLinkageDeclarations(
621  getNameLoc(), HasNonFunction, EquivalentNonFunctions);
622 
623  Decls.set_size(N);
624 
625  if (HasNonFunction && (HasFunction || HasUnresolved))
626  Ambiguous = true;
627 
628  if (Ambiguous)
629  setAmbiguous(LookupResult::AmbiguousReference);
630  else if (HasUnresolved)
632  else if (N > 1 || HasFunctionTemplate)
633  ResultKind = LookupResult::FoundOverloaded;
634  else
635  ResultKind = LookupResult::Found;
636 }
637 
638 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
640  for (I = P.begin(), E = P.end(); I != E; ++I)
641  for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE;
642  ++DI)
643  addDecl(*DI);
644 }
645 
647  Paths = new CXXBasePaths;
648  Paths->swap(P);
649  addDeclsFromBasePaths(*Paths);
650  resolveKind();
651  setAmbiguous(AmbiguousBaseSubobjects);
652 }
653 
655  Paths = new CXXBasePaths;
656  Paths->swap(P);
657  addDeclsFromBasePaths(*Paths);
658  resolveKind();
659  setAmbiguous(AmbiguousBaseSubobjectTypes);
660 }
661 
662 void LookupResult::print(raw_ostream &Out) {
663  Out << Decls.size() << " result(s)";
664  if (isAmbiguous()) Out << ", ambiguous";
665  if (Paths) Out << ", base paths present";
666 
667  for (iterator I = begin(), E = end(); I != E; ++I) {
668  Out << "\n";
669  (*I)->print(Out, 2);
670  }
671 }
672 
673 LLVM_DUMP_METHOD void LookupResult::dump() {
674  llvm::errs() << "lookup results for " << getLookupName().getAsString()
675  << ":\n";
676  for (NamedDecl *D : *this)
677  D->dump();
678 }
679 
680 /// Diagnose a missing builtin type.
681 static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass,
682  llvm::StringRef Name) {
683  S.Diag(SourceLocation(), diag::err_opencl_type_not_found)
684  << TypeClass << Name;
685  return S.Context.VoidTy;
686 }
687 
688 /// Lookup an OpenCL enum type.
689 static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) {
690  LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
692  S.LookupName(Result, S.TUScope);
693  if (Result.empty())
694  return diagOpenCLBuiltinTypeError(S, "enum", Name);
695  EnumDecl *Decl = Result.getAsSingle<EnumDecl>();
696  if (!Decl)
697  return diagOpenCLBuiltinTypeError(S, "enum", Name);
698  return S.Context.getEnumType(Decl);
699 }
700 
701 /// Lookup an OpenCL typedef type.
702 static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) {
703  LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
705  S.LookupName(Result, S.TUScope);
706  if (Result.empty())
707  return diagOpenCLBuiltinTypeError(S, "typedef", Name);
708  TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>();
709  if (!Decl)
710  return diagOpenCLBuiltinTypeError(S, "typedef", Name);
711  return S.Context.getTypedefType(Decl);
712 }
713 
714 /// Get the QualType instances of the return type and arguments for an OpenCL
715 /// builtin function signature.
716 /// \param S (in) The Sema instance.
717 /// \param OpenCLBuiltin (in) The signature currently handled.
718 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
719 /// type used as return type or as argument.
720 /// Only meaningful for generic types, otherwise equals 1.
721 /// \param RetTypes (out) List of the possible return types.
722 /// \param ArgTypes (out) List of the possible argument types. For each
723 /// argument, ArgTypes contains QualTypes for the Cartesian product
724 /// of (vector sizes) x (types) .
726  Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt,
727  SmallVector<QualType, 1> &RetTypes,
728  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
729  // Get the QualType instances of the return types.
730  unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
731  OCL2Qual(S, TypeTable[Sig], RetTypes);
732  GenTypeMaxCnt = RetTypes.size();
733 
734  // Get the QualType instances of the arguments.
735  // First type is the return type, skip it.
736  for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
738  OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]],
739  Ty);
740  GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
741  ArgTypes.push_back(std::move(Ty));
742  }
743 }
744 
745 /// Create a list of the candidate function overloads for an OpenCL builtin
746 /// function.
747 /// \param Context (in) The ASTContext instance.
748 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
749 /// type used as return type or as argument.
750 /// Only meaningful for generic types, otherwise equals 1.
751 /// \param FunctionList (out) List of FunctionTypes.
752 /// \param RetTypes (in) List of the possible return types.
753 /// \param ArgTypes (in) List of the possible types for the arguments.
755  ASTContext &Context, unsigned GenTypeMaxCnt,
756  std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes,
757  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
759  Context.getDefaultCallingConvention(false, false, true));
760  PI.Variadic = false;
761 
762  // Do not attempt to create any FunctionTypes if there are no return types,
763  // which happens when a type belongs to a disabled extension.
764  if (RetTypes.size() == 0)
765  return;
766 
767  // Create FunctionTypes for each (gen)type.
768  for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
769  SmallVector<QualType, 5> ArgList;
770 
771  for (unsigned A = 0; A < ArgTypes.size(); A++) {
772  // Bail out if there is an argument that has no available types.
773  if (ArgTypes[A].size() == 0)
774  return;
775 
776  // Builtins such as "max" have an "sgentype" argument that represents
777  // the corresponding scalar type of a gentype. The number of gentypes
778  // must be a multiple of the number of sgentypes.
779  assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
780  "argument type count not compatible with gentype type count");
781  unsigned Idx = IGenType % ArgTypes[A].size();
782  ArgList.push_back(ArgTypes[A][Idx]);
783  }
784 
785  FunctionList.push_back(Context.getFunctionType(
786  RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI));
787  }
788 }
789 
790 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a
791 /// non-null <Index, Len> pair, then the name is referencing an OpenCL
792 /// builtin function. Add all candidate signatures to the LookUpResult.
793 ///
794 /// \param S (in) The Sema instance.
795 /// \param LR (inout) The LookupResult instance.
796 /// \param II (in) The identifier being resolved.
797 /// \param FctIndex (in) Starting index in the BuiltinTable.
798 /// \param Len (in) The signature list has Len elements.
800  IdentifierInfo *II,
801  const unsigned FctIndex,
802  const unsigned Len) {
803  // The builtin function declaration uses generic types (gentype).
804  bool HasGenType = false;
805 
806  // Maximum number of types contained in a generic type used as return type or
807  // as argument. Only meaningful for generic types, otherwise equals 1.
808  unsigned GenTypeMaxCnt;
809 
810  ASTContext &Context = S.Context;
811 
812  for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
813  const OpenCLBuiltinStruct &OpenCLBuiltin =
814  BuiltinTable[FctIndex + SignatureIndex];
815 
816  // Ignore this builtin function if it is not available in the currently
817  // selected language version.
818  if (!isOpenCLVersionContainedInMask(Context.getLangOpts(),
819  OpenCLBuiltin.Versions))
820  continue;
821 
822  // Ignore this builtin function if it carries an extension macro that is
823  // not defined. This indicates that the extension is not supported by the
824  // target, so the builtin function should not be available.
825  StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension];
826  if (!Extensions.empty()) {
828  Extensions.split(ExtVec, " ");
829  bool AllExtensionsDefined = true;
830  for (StringRef Ext : ExtVec) {
831  if (!S.getPreprocessor().isMacroDefined(Ext)) {
832  AllExtensionsDefined = false;
833  break;
834  }
835  }
836  if (!AllExtensionsDefined)
837  continue;
838  }
839 
840  SmallVector<QualType, 1> RetTypes;
842 
843  // Obtain QualType lists for the function signature.
844  GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes,
845  ArgTypes);
846  if (GenTypeMaxCnt > 1) {
847  HasGenType = true;
848  }
849 
850  // Create function overload for each type combination.
851  std::vector<QualType> FunctionList;
852  GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
853  ArgTypes);
854 
855  SourceLocation Loc = LR.getNameLoc();
857  FunctionDecl *NewOpenCLBuiltin;
858 
859  for (const auto &FTy : FunctionList) {
860  NewOpenCLBuiltin = FunctionDecl::Create(
861  Context, Parent, Loc, Loc, II, FTy, /*TInfo=*/nullptr, SC_Extern,
862  S.getCurFPFeatures().isFPConstrained(), false,
863  FTy->isFunctionProtoType());
864  NewOpenCLBuiltin->setImplicit();
865 
866  // Create Decl objects for each parameter, adding them to the
867  // FunctionDecl.
868  const auto *FP = cast<FunctionProtoType>(FTy);
870  for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
872  Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(),
873  nullptr, FP->getParamType(IParm), nullptr, SC_None, nullptr);
874  Parm->setScopeInfo(0, IParm);
875  ParmList.push_back(Parm);
876  }
877  NewOpenCLBuiltin->setParams(ParmList);
878 
879  // Add function attributes.
880  if (OpenCLBuiltin.IsPure)
881  NewOpenCLBuiltin->addAttr(PureAttr::CreateImplicit(Context));
882  if (OpenCLBuiltin.IsConst)
883  NewOpenCLBuiltin->addAttr(ConstAttr::CreateImplicit(Context));
884  if (OpenCLBuiltin.IsConv)
885  NewOpenCLBuiltin->addAttr(ConvergentAttr::CreateImplicit(Context));
886 
887  if (!S.getLangOpts().OpenCLCPlusPlus)
888  NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context));
889 
890  LR.addDecl(NewOpenCLBuiltin);
891  }
892  }
893 
894  // If we added overloads, need to resolve the lookup result.
895  if (Len > 1 || HasGenType)
896  LR.resolveKind();
897 }
898 
899 /// Lookup a builtin function, when name lookup would otherwise
900 /// fail.
902  Sema::LookupNameKind NameKind = R.getLookupKind();
903 
904  // If we didn't find a use of this identifier, and if the identifier
905  // corresponds to a compiler builtin, create the decl object for the builtin
906  // now, injecting it into translation unit scope, and return it.
907  if (NameKind == Sema::LookupOrdinaryName ||
910  if (II) {
911  if (getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
912  if (II == getASTContext().getMakeIntegerSeqName()) {
913  R.addDecl(getASTContext().getMakeIntegerSeqDecl());
914  return true;
915  } else if (II == getASTContext().getTypePackElementName()) {
916  R.addDecl(getASTContext().getTypePackElementDecl());
917  return true;
918  }
919  }
920 
921  // Check if this is an OpenCL Builtin, and if so, insert its overloads.
922  if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) {
923  auto Index = isOpenCLBuiltin(II->getName());
924  if (Index.first) {
925  InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1,
926  Index.second);
927  return true;
928  }
929  }
930 
931  // If this is a builtin on this (or all) targets, create the decl.
932  if (unsigned BuiltinID = II->getBuiltinID()) {
933  // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
934  // library functions like 'malloc'. Instead, we'll just error.
935  if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) &&
936  Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
937  return false;
938 
939  if (NamedDecl *D =
940  LazilyCreateBuiltin(II, BuiltinID, TUScope,
941  R.isForRedeclaration(), R.getNameLoc())) {
942  R.addDecl(D);
943  return true;
944  }
945  }
946  }
947  }
948 
949  return false;
950 }
951 
952 /// Looks up the declaration of "struct objc_super" and
953 /// saves it for later use in building builtin declaration of
954 /// objc_msgSendSuper and objc_msgSendSuper_stret.
956  ASTContext &Context = Sema.Context;
957  LookupResult Result(Sema, &Context.Idents.get("objc_super"), SourceLocation(),
959  Sema.LookupName(Result, S);
960  if (Result.getResultKind() == LookupResult::Found)
961  if (const TagDecl *TD = Result.getAsSingle<TagDecl>())
962  Context.setObjCSuperType(Context.getTagDeclType(TD));
963 }
964 
966  if (ID == Builtin::BIobjc_msgSendSuper)
967  LookupPredefedObjCSuperType(*this, S);
968 }
969 
970 /// Determine whether we can declare a special member function within
971 /// the class at this point.
973  // We need to have a definition for the class.
974  if (!Class->getDefinition() || Class->isDependentContext())
975  return false;
976 
977  // We can't be in the middle of defining the class.
978  return !Class->isBeingDefined();
979 }
980 
983  return;
984 
985  // If the default constructor has not yet been declared, do so now.
986  if (Class->needsImplicitDefaultConstructor())
987  DeclareImplicitDefaultConstructor(Class);
988 
989  // If the copy constructor has not yet been declared, do so now.
990  if (Class->needsImplicitCopyConstructor())
991  DeclareImplicitCopyConstructor(Class);
992 
993  // If the copy assignment operator has not yet been declared, do so now.
994  if (Class->needsImplicitCopyAssignment())
995  DeclareImplicitCopyAssignment(Class);
996 
997  if (getLangOpts().CPlusPlus11) {
998  // If the move constructor has not yet been declared, do so now.
999  if (Class->needsImplicitMoveConstructor())
1000  DeclareImplicitMoveConstructor(Class);
1001 
1002  // If the move assignment operator has not yet been declared, do so now.
1003  if (Class->needsImplicitMoveAssignment())
1004  DeclareImplicitMoveAssignment(Class);
1005  }
1006 
1007  // If the destructor has not yet been declared, do so now.
1008  if (Class->needsImplicitDestructor())
1009  DeclareImplicitDestructor(Class);
1010 }
1011 
1012 /// Determine whether this is the name of an implicitly-declared
1013 /// special member function.
1015  switch (Name.getNameKind()) {
1018  return true;
1019 
1021  return Name.getCXXOverloadedOperator() == OO_Equal;
1022 
1023  default:
1024  break;
1025  }
1026 
1027  return false;
1028 }
1029 
1030 /// If there are any implicit member functions with the given name
1031 /// that need to be declared in the given declaration context, do so.
1033  DeclarationName Name,
1034  SourceLocation Loc,
1035  const DeclContext *DC) {
1036  if (!DC)
1037  return;
1038 
1039  switch (Name.getNameKind()) {
1041  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
1042  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
1043  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
1044  if (Record->needsImplicitDefaultConstructor())
1046  if (Record->needsImplicitCopyConstructor())
1048  if (S.getLangOpts().CPlusPlus11 &&
1049  Record->needsImplicitMoveConstructor())
1051  }
1052  break;
1053 
1055  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
1056  if (Record->getDefinition() && Record->needsImplicitDestructor() &&
1058  S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
1059  break;
1060 
1062  if (Name.getCXXOverloadedOperator() != OO_Equal)
1063  break;
1064 
1065  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
1066  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
1067  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
1068  if (Record->needsImplicitCopyAssignment())
1070  if (S.getLangOpts().CPlusPlus11 &&
1071  Record->needsImplicitMoveAssignment())
1073  }
1074  }
1075  break;
1076 
1078  S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc);
1079  break;
1080 
1081  default:
1082  break;
1083  }
1084 }
1085 
1086 // Adds all qualifying matches for a name within a decl context to the
1087 // given lookup result. Returns true if any matches were found.
1088 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
1089  bool Found = false;
1090 
1091  // Lazily declare C++ special member functions.
1092  if (S.getLangOpts().CPlusPlus)
1094  DC);
1095 
1096  // Perform lookup into this declaration context.
1098  for (NamedDecl *D : DR) {
1099  if ((D = R.getAcceptableDecl(D))) {
1100  R.addDecl(D);
1101  Found = true;
1102  }
1103  }
1104 
1105  if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R))
1106  return true;
1107 
1108  if (R.getLookupName().getNameKind()
1111  !isa<CXXRecordDecl>(DC))
1112  return Found;
1113 
1114  // C++ [temp.mem]p6:
1115  // A specialization of a conversion function template is not found by
1116  // name lookup. Instead, any conversion function templates visible in the
1117  // context of the use are considered. [...]
1118  const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1119  if (!Record->isCompleteDefinition())
1120  return Found;
1121 
1122  // For conversion operators, 'operator auto' should only match
1123  // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
1124  // as a candidate for template substitution.
1125  auto *ContainedDeducedType =
1127  if (R.getLookupName().getNameKind() ==
1129  ContainedDeducedType && ContainedDeducedType->isUndeducedType())
1130  return Found;
1131 
1133  UEnd = Record->conversion_end(); U != UEnd; ++U) {
1134  FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
1135  if (!ConvTemplate)
1136  continue;
1137 
1138  // When we're performing lookup for the purposes of redeclaration, just
1139  // add the conversion function template. When we deduce template
1140  // arguments for specializations, we'll end up unifying the return
1141  // type of the new declaration with the type of the function template.
1142  if (R.isForRedeclaration()) {
1143  R.addDecl(ConvTemplate);
1144  Found = true;
1145  continue;
1146  }
1147 
1148  // C++ [temp.mem]p6:
1149  // [...] For each such operator, if argument deduction succeeds
1150  // (14.9.2.3), the resulting specialization is used as if found by
1151  // name lookup.
1152  //
1153  // When referencing a conversion function for any purpose other than
1154  // a redeclaration (such that we'll be building an expression with the
1155  // result), perform template argument deduction and place the
1156  // specialization into the result set. We do this to avoid forcing all
1157  // callers to perform special deduction for conversion functions.
1159  FunctionDecl *Specialization = nullptr;
1160 
1161  const FunctionProtoType *ConvProto
1162  = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
1163  assert(ConvProto && "Nonsensical conversion function template type");
1164 
1165  // Compute the type of the function that we would expect the conversion
1166  // function to have, if it were to match the name given.
1167  // FIXME: Calling convention!
1169  EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
1170  EPI.ExceptionSpec = EST_None;
1173  None, EPI);
1174 
1175  // Perform template argument deduction against the type that we would
1176  // expect the function to have.
1177  if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
1178  Specialization, Info)
1179  == Sema::TDK_Success) {
1181  Found = true;
1182  }
1183  }
1184 
1185  return Found;
1186 }
1187 
1188 // Performs C++ unqualified lookup into the given file context.
1189 static bool
1191  DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
1192 
1193  assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
1194 
1195  // Perform direct name lookup into the LookupCtx.
1196  bool Found = LookupDirect(S, R, NS);
1197 
1198  // Perform direct name lookup into the namespaces nominated by the
1199  // using directives whose common ancestor is this namespace.
1200  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
1201  if (LookupDirect(S, R, UUE.getNominatedNamespace()))
1202  Found = true;
1203 
1204  R.resolveKind();
1205 
1206  return Found;
1207 }
1208 
1210  if (DeclContext *Ctx = S->getEntity())
1211  return Ctx->isFileContext();
1212  return false;
1213 }
1214 
1215 /// Find the outer declaration context from this scope. This indicates the
1216 /// context that we should search up to (exclusive) before considering the
1217 /// parent of the specified scope.
1219  for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent())
1220  if (DeclContext *DC = OuterS->getLookupEntity())
1221  return DC;
1222  return nullptr;
1223 }
1224 
1225 namespace {
1226 /// An RAII object to specify that we want to find block scope extern
1227 /// declarations.
1228 struct FindLocalExternScope {
1229  FindLocalExternScope(LookupResult &R)
1230  : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1231  Decl::IDNS_LocalExtern) {
1234  }
1235  void restore() {
1236  R.setFindLocalExtern(OldFindLocalExtern);
1237  }
1238  ~FindLocalExternScope() {
1239  restore();
1240  }
1241  LookupResult &R;
1242  bool OldFindLocalExtern;
1243 };
1244 } // end anonymous namespace
1245 
1246 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1247  assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1248 
1249  DeclarationName Name = R.getLookupName();
1250  Sema::LookupNameKind NameKind = R.getLookupKind();
1251 
1252  // If this is the name of an implicitly-declared special member function,
1253  // go through the scope stack to implicitly declare
1255  for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1256  if (DeclContext *DC = PreS->getEntity())
1257  DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1258  }
1259 
1260  // Implicitly declare member functions with the name we're looking for, if in
1261  // fact we are in a scope where it matters.
1262 
1263  Scope *Initial = S;
1265  I = IdResolver.begin(Name),
1266  IEnd = IdResolver.end();
1267 
1268  // First we lookup local scope.
1269  // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1270  // ...During unqualified name lookup (3.4.1), the names appear as if
1271  // they were declared in the nearest enclosing namespace which contains
1272  // both the using-directive and the nominated namespace.
1273  // [Note: in this context, "contains" means "contains directly or
1274  // indirectly".
1275  //
1276  // For example:
1277  // namespace A { int i; }
1278  // void foo() {
1279  // int i;
1280  // {
1281  // using namespace A;
1282  // ++i; // finds local 'i', A::i appears at global scope
1283  // }
1284  // }
1285  //
1286  UnqualUsingDirectiveSet UDirs(*this);
1287  bool VisitedUsingDirectives = false;
1288  bool LeftStartingScope = false;
1289 
1290  // When performing a scope lookup, we want to find local extern decls.
1291  FindLocalExternScope FindLocals(R);
1292 
1293  for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1294  bool SearchNamespaceScope = true;
1295  // Check whether the IdResolver has anything in this scope.
1296  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1297  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1298  if (NameKind == LookupRedeclarationWithLinkage &&
1299  !(*I)->isTemplateParameter()) {
1300  // If it's a template parameter, we still find it, so we can diagnose
1301  // the invalid redeclaration.
1302 
1303  // Determine whether this (or a previous) declaration is
1304  // out-of-scope.
1305  if (!LeftStartingScope && !Initial->isDeclScope(*I))
1306  LeftStartingScope = true;
1307 
1308  // If we found something outside of our starting scope that
1309  // does not have linkage, skip it.
1310  if (LeftStartingScope && !((*I)->hasLinkage())) {
1311  R.setShadowed();
1312  continue;
1313  }
1314  } else {
1315  // We found something in this scope, we should not look at the
1316  // namespace scope
1317  SearchNamespaceScope = false;
1318  }
1319  R.addDecl(ND);
1320  }
1321  }
1322  if (!SearchNamespaceScope) {
1323  R.resolveKind();
1324  if (S->isClassScope())
1325  if (CXXRecordDecl *Record =
1326  dyn_cast_or_null<CXXRecordDecl>(S->getEntity()))
1327  R.setNamingClass(Record);
1328  return true;
1329  }
1330 
1331  if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1332  // C++11 [class.friend]p11:
1333  // If a friend declaration appears in a local class and the name
1334  // specified is an unqualified name, a prior declaration is
1335  // looked up without considering scopes that are outside the
1336  // innermost enclosing non-class scope.
1337  return false;
1338  }
1339 
1340  if (DeclContext *Ctx = S->getLookupEntity()) {
1341  DeclContext *OuterCtx = findOuterContext(S);
1342  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1343  // We do not directly look into transparent contexts, since
1344  // those entities will be found in the nearest enclosing
1345  // non-transparent context.
1346  if (Ctx->isTransparentContext())
1347  continue;
1348 
1349  // We do not look directly into function or method contexts,
1350  // since all of the local variables and parameters of the
1351  // function/method are present within the Scope.
1352  if (Ctx->isFunctionOrMethod()) {
1353  // If we have an Objective-C instance method, look for ivars
1354  // in the corresponding interface.
1355  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1356  if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1357  if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1358  ObjCInterfaceDecl *ClassDeclared;
1359  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1360  Name.getAsIdentifierInfo(),
1361  ClassDeclared)) {
1362  if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1363  R.addDecl(ND);
1364  R.resolveKind();
1365  return true;
1366  }
1367  }
1368  }
1369  }
1370 
1371  continue;
1372  }
1373 
1374  // If this is a file context, we need to perform unqualified name
1375  // lookup considering using directives.
1376  if (Ctx->isFileContext()) {
1377  // If we haven't handled using directives yet, do so now.
1378  if (!VisitedUsingDirectives) {
1379  // Add using directives from this context up to the top level.
1380  for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1381  if (UCtx->isTransparentContext())
1382  continue;
1383 
1384  UDirs.visit(UCtx, UCtx);
1385  }
1386 
1387  // Find the innermost file scope, so we can add using directives
1388  // from local scopes.
1389  Scope *InnermostFileScope = S;
1390  while (InnermostFileScope &&
1391  !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1392  InnermostFileScope = InnermostFileScope->getParent();
1393  UDirs.visitScopeChain(Initial, InnermostFileScope);
1394 
1395  UDirs.done();
1396 
1397  VisitedUsingDirectives = true;
1398  }
1399 
1400  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1401  R.resolveKind();
1402  return true;
1403  }
1404 
1405  continue;
1406  }
1407 
1408  // Perform qualified name lookup into this context.
1409  // FIXME: In some cases, we know that every name that could be found by
1410  // this qualified name lookup will also be on the identifier chain. For
1411  // example, inside a class without any base classes, we never need to
1412  // perform qualified lookup because all of the members are on top of the
1413  // identifier chain.
1414  if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1415  return true;
1416  }
1417  }
1418  }
1419 
1420  // Stop if we ran out of scopes.
1421  // FIXME: This really, really shouldn't be happening.
1422  if (!S) return false;
1423 
1424  // If we are looking for members, no need to look into global/namespace scope.
1425  if (NameKind == LookupMemberName)
1426  return false;
1427 
1428  // Collect UsingDirectiveDecls in all scopes, and recursively all
1429  // nominated namespaces by those using-directives.
1430  //
1431  // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1432  // don't build it for each lookup!
1433  if (!VisitedUsingDirectives) {
1434  UDirs.visitScopeChain(Initial, S);
1435  UDirs.done();
1436  }
1437 
1438  // If we're not performing redeclaration lookup, do not look for local
1439  // extern declarations outside of a function scope.
1440  if (!R.isForRedeclaration())
1441  FindLocals.restore();
1442 
1443  // Lookup namespace scope, and global scope.
1444  // Unqualified name lookup in C++ requires looking into scopes
1445  // that aren't strictly lexical, and therefore we walk through the
1446  // context as well as walking through the scopes.
1447  for (; S; S = S->getParent()) {
1448  // Check whether the IdResolver has anything in this scope.
1449  bool Found = false;
1450  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1451  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1452  // We found something. Look for anything else in our scope
1453  // with this same name and in an acceptable identifier
1454  // namespace, so that we can construct an overload set if we
1455  // need to.
1456  Found = true;
1457  R.addDecl(ND);
1458  }
1459  }
1460 
1461  if (Found && S->isTemplateParamScope()) {
1462  R.resolveKind();
1463  return true;
1464  }
1465 
1466  DeclContext *Ctx = S->getLookupEntity();
1467  if (Ctx) {
1468  DeclContext *OuterCtx = findOuterContext(S);
1469  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1470  // We do not directly look into transparent contexts, since
1471  // those entities will be found in the nearest enclosing
1472  // non-transparent context.
1473  if (Ctx->isTransparentContext())
1474  continue;
1475 
1476  // If we have a context, and it's not a context stashed in the
1477  // template parameter scope for an out-of-line definition, also
1478  // look into that context.
1479  if (!(Found && S->isTemplateParamScope())) {
1480  assert(Ctx->isFileContext() &&
1481  "We should have been looking only at file context here already.");
1482 
1483  // Look into context considering using-directives.
1484  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1485  Found = true;
1486  }
1487 
1488  if (Found) {
1489  R.resolveKind();
1490  return true;
1491  }
1492 
1493  if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1494  return false;
1495  }
1496  }
1497 
1498  if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1499  return false;
1500  }
1501 
1502  return !R.empty();
1503 }
1504 
1506  if (auto *M = getCurrentModule())
1507  Context.mergeDefinitionIntoModule(ND, M);
1508  else
1509  // We're not building a module; just make the definition visible.
1511 
1512  // If ND is a template declaration, make the template parameters
1513  // visible too. They're not (necessarily) within a mergeable DeclContext.
1514  if (auto *TD = dyn_cast<TemplateDecl>(ND))
1515  for (auto *Param : *TD->getTemplateParameters())
1516  makeMergedDefinitionVisible(Param);
1517 }
1518 
1519 /// Find the module in which the given declaration was defined.
1520 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1521  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1522  // If this function was instantiated from a template, the defining module is
1523  // the module containing the pattern.
1524  if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1525  Entity = Pattern;
1526  } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1527  if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1528  Entity = Pattern;
1529  } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1530  if (auto *Pattern = ED->getTemplateInstantiationPattern())
1531  Entity = Pattern;
1532  } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1533  if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1534  Entity = Pattern;
1535  }
1536 
1537  // Walk up to the containing context. That might also have been instantiated
1538  // from a template.
1539  DeclContext *Context = Entity->getLexicalDeclContext();
1540  if (Context->isFileContext())
1541  return S.getOwningModule(Entity);
1542  return getDefiningModule(S, cast<Decl>(Context));
1543 }
1544 
1546  unsigned N = CodeSynthesisContexts.size();
1547  for (unsigned I = CodeSynthesisContextLookupModules.size();
1548  I != N; ++I) {
1549  Module *M = CodeSynthesisContexts[I].Entity ?
1550  getDefiningModule(*this, CodeSynthesisContexts[I].Entity) :
1551  nullptr;
1552  if (M && !LookupModulesCache.insert(M).second)
1553  M = nullptr;
1554  CodeSynthesisContextLookupModules.push_back(M);
1555  }
1556  return LookupModulesCache;
1557 }
1558 
1559 /// Determine whether the module M is part of the current module from the
1560 /// perspective of a module-private visibility check.
1561 static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts) {
1562  // If M is the global module fragment of a module that we've not yet finished
1563  // parsing, then it must be part of the current module.
1564  return M->getTopLevelModuleName() == LangOpts.CurrentModule ||
1565  (M->Kind == Module::GlobalModuleFragment && !M->Parent);
1566 }
1567 
1569  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1570  if (isModuleVisible(Merged))
1571  return true;
1572  return false;
1573 }
1574 
1576  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1577  if (isInCurrentModule(Merged, getLangOpts()))
1578  return true;
1579  return false;
1580 }
1581 
1582 template<typename ParmDecl>
1583 static bool
1584 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1586  if (!D->hasDefaultArgument())
1587  return false;
1588 
1589  while (D) {
1590  auto &DefaultArg = D->getDefaultArgStorage();
1591  if (!DefaultArg.isInherited() && S.isVisible(D))
1592  return true;
1593 
1594  if (!DefaultArg.isInherited() && Modules) {
1595  auto *NonConstD = const_cast<ParmDecl*>(D);
1596  Modules->push_back(S.getOwningModule(NonConstD));
1597  }
1598 
1599  // If there was a previous default argument, maybe its parameter is visible.
1600  D = DefaultArg.getInheritedFrom();
1601  }
1602  return false;
1603 }
1604 
1607  if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1608  return ::hasVisibleDefaultArgument(*this, P, Modules);
1609  if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1610  return ::hasVisibleDefaultArgument(*this, P, Modules);
1611  return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1612  Modules);
1613 }
1614 
1615 template<typename Filter>
1616 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1618  Filter F) {
1619  bool HasFilteredRedecls = false;
1620 
1621  for (auto *Redecl : D->redecls()) {
1622  auto *R = cast<NamedDecl>(Redecl);
1623  if (!F(R))
1624  continue;
1625 
1626  if (S.isVisible(R))
1627  return true;
1628 
1629  HasFilteredRedecls = true;
1630 
1631  if (Modules)
1632  Modules->push_back(R->getOwningModule());
1633  }
1634 
1635  // Only return false if there is at least one redecl that is not filtered out.
1636  if (HasFilteredRedecls)
1637  return false;
1638 
1639  return true;
1640 }
1641 
1643  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1644  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1645  if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1646  return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1647  if (auto *FD = dyn_cast<FunctionDecl>(D))
1648  return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1649  if (auto *VD = dyn_cast<VarDecl>(D))
1650  return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1651  llvm_unreachable("unknown explicit specialization kind");
1652  });
1653 }
1654 
1656  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1657  assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1658  "not a member specialization");
1659  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1660  // If the specialization is declared at namespace scope, then it's a member
1661  // specialization declaration. If it's lexically inside the class
1662  // definition then it was instantiated.
1663  //
1664  // FIXME: This is a hack. There should be a better way to determine this.
1665  // FIXME: What about MS-style explicit specializations declared within a
1666  // class definition?
1667  return D->getLexicalDeclContext()->isFileContext();
1668  });
1669 }
1670 
1671 /// Determine whether a declaration is visible to name lookup.
1672 ///
1673 /// This routine determines whether the declaration D is visible in the current
1674 /// lookup context, taking into account the current template instantiation
1675 /// stack. During template instantiation, a declaration is visible if it is
1676 /// visible from a module containing any entity on the template instantiation
1677 /// path (by instantiating a template, you allow it to see the declarations that
1678 /// your module can see, including those later on in your module).
1679 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1680  assert(!D->isUnconditionallyVisible() &&
1681  "should not call this: not in slow case");
1682 
1683  Module *DeclModule = SemaRef.getOwningModule(D);
1684  assert(DeclModule && "hidden decl has no owning module");
1685 
1686  // If the owning module is visible, the decl is visible.
1687  if (SemaRef.isModuleVisible(DeclModule, D->isModulePrivate()))
1688  return true;
1689 
1690  // Determine whether a decl context is a file context for the purpose of
1691  // visibility. This looks through some (export and linkage spec) transparent
1692  // contexts, but not others (enums).
1693  auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1694  return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1695  isa<ExportDecl>(DC);
1696  };
1697 
1698  // If this declaration is not at namespace scope
1699  // then it is visible if its lexical parent has a visible definition.
1701  if (DC && !IsEffectivelyFileContext(DC)) {
1702  // For a parameter, check whether our current template declaration's
1703  // lexical context is visible, not whether there's some other visible
1704  // definition of it, because parameters aren't "within" the definition.
1705  //
1706  // In C++ we need to check for a visible definition due to ODR merging,
1707  // and in C we must not because each declaration of a function gets its own
1708  // set of declarations for tags in prototype scope.
1709  bool VisibleWithinParent;
1710  if (D->isTemplateParameter()) {
1711  bool SearchDefinitions = true;
1712  if (const auto *DCD = dyn_cast<Decl>(DC)) {
1713  if (const auto *TD = DCD->getDescribedTemplate()) {
1714  TemplateParameterList *TPL = TD->getTemplateParameters();
1715  auto Index = getDepthAndIndex(D).second;
1716  SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D;
1717  }
1718  }
1719  if (SearchDefinitions)
1720  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1721  else
1722  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1723  } else if (isa<ParmVarDecl>(D) ||
1724  (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1725  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1726  else if (D->isModulePrivate()) {
1727  // A module-private declaration is only visible if an enclosing lexical
1728  // parent was merged with another definition in the current module.
1729  VisibleWithinParent = false;
1730  do {
1731  if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1732  VisibleWithinParent = true;
1733  break;
1734  }
1735  DC = DC->getLexicalParent();
1736  } while (!IsEffectivelyFileContext(DC));
1737  } else {
1738  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1739  }
1740 
1741  if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1742  // FIXME: Do something better in this case.
1743  !SemaRef.getLangOpts().ModulesLocalVisibility) {
1744  // Cache the fact that this declaration is implicitly visible because
1745  // its parent has a visible definition.
1747  }
1748  return VisibleWithinParent;
1749  }
1750 
1751  return false;
1752 }
1753 
1754 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1755  // The module might be ordinarily visible. For a module-private query, that
1756  // means it is part of the current module. For any other query, that means it
1757  // is in our visible module set.
1758  if (ModulePrivate) {
1759  if (isInCurrentModule(M, getLangOpts()))
1760  return true;
1761  } else {
1762  if (VisibleModules.isVisible(M))
1763  return true;
1764  }
1765 
1766  // Otherwise, it might be visible by virtue of the query being within a
1767  // template instantiation or similar that is permitted to look inside M.
1768 
1769  // Find the extra places where we need to look.
1770  const auto &LookupModules = getLookupModules();
1771  if (LookupModules.empty())
1772  return false;
1773 
1774  // If our lookup set contains the module, it's visible.
1775  if (LookupModules.count(M))
1776  return true;
1777 
1778  // For a module-private query, that's everywhere we get to look.
1779  if (ModulePrivate)
1780  return false;
1781 
1782  // Check whether M is transitively exported to an import of the lookup set.
1783  return llvm::any_of(LookupModules, [&](const Module *LookupM) {
1784  return LookupM->isModuleVisible(M);
1785  });
1786 }
1787 
1788 bool Sema::isVisibleSlow(const NamedDecl *D) {
1789  return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1790 }
1791 
1792 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1793  // FIXME: If there are both visible and hidden declarations, we need to take
1794  // into account whether redeclaration is possible. Example:
1795  //
1796  // Non-imported module:
1797  // int f(T); // #1
1798  // Some TU:
1799  // static int f(U); // #2, not a redeclaration of #1
1800  // int f(T); // #3, finds both, should link with #1 if T != U, but
1801  // // with #2 if T == U; neither should be ambiguous.
1802  for (auto *D : R) {
1803  if (isVisible(D))
1804  return true;
1805  assert(D->isExternallyDeclarable() &&
1806  "should not have hidden, non-externally-declarable result here");
1807  }
1808 
1809  // This function is called once "New" is essentially complete, but before a
1810  // previous declaration is attached. We can't query the linkage of "New" in
1811  // general, because attaching the previous declaration can change the
1812  // linkage of New to match the previous declaration.
1813  //
1814  // However, because we've just determined that there is no *visible* prior
1815  // declaration, we can compute the linkage here. There are two possibilities:
1816  //
1817  // * This is not a redeclaration; it's safe to compute the linkage now.
1818  //
1819  // * This is a redeclaration of a prior declaration that is externally
1820  // redeclarable. In that case, the linkage of the declaration is not
1821  // changed by attaching the prior declaration, because both are externally
1822  // declarable (and thus ExternalLinkage or VisibleNoLinkage).
1823  //
1824  // FIXME: This is subtle and fragile.
1825  return New->isExternallyDeclarable();
1826 }
1827 
1828 /// Retrieve the visible declaration corresponding to D, if any.
1829 ///
1830 /// This routine determines whether the declaration D is visible in the current
1831 /// module, with the current imports. If not, it checks whether any
1832 /// redeclaration of D is visible, and if so, returns that declaration.
1833 ///
1834 /// \returns D, or a visible previous declaration of D, whichever is more recent
1835 /// and visible. If no declaration of D is visible, returns null.
1837  unsigned IDNS) {
1838  assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1839 
1840  for (auto RD : D->redecls()) {
1841  // Don't bother with extra checks if we already know this one isn't visible.
1842  if (RD == D)
1843  continue;
1844 
1845  auto ND = cast<NamedDecl>(RD);
1846  // FIXME: This is wrong in the case where the previous declaration is not
1847  // visible in the same scope as D. This needs to be done much more
1848  // carefully.
1849  if (ND->isInIdentifierNamespace(IDNS) &&
1850  LookupResult::isVisible(SemaRef, ND))
1851  return ND;
1852  }
1853 
1854  return nullptr;
1855 }
1856 
1859  assert(!isVisible(D) && "not in slow case");
1860  return hasVisibleDeclarationImpl(*this, D, Modules,
1861  [](const NamedDecl *) { return true; });
1862 }
1863 
1864 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1865  if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1866  // Namespaces are a bit of a special case: we expect there to be a lot of
1867  // redeclarations of some namespaces, all declarations of a namespace are
1868  // essentially interchangeable, all declarations are found by name lookup
1869  // if any is, and namespaces are never looked up during template
1870  // instantiation. So we benefit from caching the check in this case, and
1871  // it is correct to do so.
1872  auto *Key = ND->getCanonicalDecl();
1873  if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1874  return Acceptable;
1875  auto *Acceptable = isVisible(getSema(), Key)
1876  ? Key
1877  : findAcceptableDecl(getSema(), Key, IDNS);
1878  if (Acceptable)
1879  getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1880  return Acceptable;
1881  }
1882 
1883  return findAcceptableDecl(getSema(), D, IDNS);
1884 }
1885 
1886 /// Perform unqualified name lookup starting from a given
1887 /// scope.
1888 ///
1889 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1890 /// used to find names within the current scope. For example, 'x' in
1891 /// @code
1892 /// int x;
1893 /// int f() {
1894 /// return x; // unqualified name look finds 'x' in the global scope
1895 /// }
1896 /// @endcode
1897 ///
1898 /// Different lookup criteria can find different names. For example, a
1899 /// particular scope can have both a struct and a function of the same
1900 /// name, and each can be found by certain lookup criteria. For more
1901 /// information about lookup criteria, see the documentation for the
1902 /// class LookupCriteria.
1903 ///
1904 /// @param S The scope from which unqualified name lookup will
1905 /// begin. If the lookup criteria permits, name lookup may also search
1906 /// in the parent scopes.
1907 ///
1908 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1909 /// look up and the lookup kind), and is updated with the results of lookup
1910 /// including zero or more declarations and possibly additional information
1911 /// used to diagnose ambiguities.
1912 ///
1913 /// @returns \c true if lookup succeeded and false otherwise.
1914 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1915  DeclarationName Name = R.getLookupName();
1916  if (!Name) return false;
1917 
1918  LookupNameKind NameKind = R.getLookupKind();
1919 
1920  if (!getLangOpts().CPlusPlus) {
1921  // Unqualified name lookup in C/Objective-C is purely lexical, so
1922  // search in the declarations attached to the name.
1923  if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1924  // Find the nearest non-transparent declaration scope.
1925  while (!(S->getFlags() & Scope::DeclScope) ||
1926  (S->getEntity() && S->getEntity()->isTransparentContext()))
1927  S = S->getParent();
1928  }
1929 
1930  // When performing a scope lookup, we want to find local extern decls.
1931  FindLocalExternScope FindLocals(R);
1932 
1933  // Scan up the scope chain looking for a decl that matches this
1934  // identifier that is in the appropriate namespace. This search
1935  // should not take long, as shadowing of names is uncommon, and
1936  // deep shadowing is extremely uncommon.
1937  bool LeftStartingScope = false;
1938 
1939  for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1940  IEnd = IdResolver.end();
1941  I != IEnd; ++I)
1942  if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1943  if (NameKind == LookupRedeclarationWithLinkage) {
1944  // Determine whether this (or a previous) declaration is
1945  // out-of-scope.
1946  if (!LeftStartingScope && !S->isDeclScope(*I))
1947  LeftStartingScope = true;
1948 
1949  // If we found something outside of our starting scope that
1950  // does not have linkage, skip it.
1951  if (LeftStartingScope && !((*I)->hasLinkage())) {
1952  R.setShadowed();
1953  continue;
1954  }
1955  }
1956  else if (NameKind == LookupObjCImplicitSelfParam &&
1957  !isa<ImplicitParamDecl>(*I))
1958  continue;
1959 
1960  R.addDecl(D);
1961 
1962  // Check whether there are any other declarations with the same name
1963  // and in the same scope.
1964  if (I != IEnd) {
1965  // Find the scope in which this declaration was declared (if it
1966  // actually exists in a Scope).
1967  while (S && !S->isDeclScope(D))
1968  S = S->getParent();
1969 
1970  // If the scope containing the declaration is the translation unit,
1971  // then we'll need to perform our checks based on the matching
1972  // DeclContexts rather than matching scopes.
1974  S = nullptr;
1975 
1976  // Compute the DeclContext, if we need it.
1977  DeclContext *DC = nullptr;
1978  if (!S)
1979  DC = (*I)->getDeclContext()->getRedeclContext();
1980 
1981  IdentifierResolver::iterator LastI = I;
1982  for (++LastI; LastI != IEnd; ++LastI) {
1983  if (S) {
1984  // Match based on scope.
1985  if (!S->isDeclScope(*LastI))
1986  break;
1987  } else {
1988  // Match based on DeclContext.
1989  DeclContext *LastDC
1990  = (*LastI)->getDeclContext()->getRedeclContext();
1991  if (!LastDC->Equals(DC))
1992  break;
1993  }
1994 
1995  // If the declaration is in the right namespace and visible, add it.
1996  if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1997  R.addDecl(LastD);
1998  }
1999 
2000  R.resolveKind();
2001  }
2002 
2003  return true;
2004  }
2005  } else {
2006  // Perform C++ unqualified name lookup.
2007  if (CppLookupName(R, S))
2008  return true;
2009  }
2010 
2011  // If we didn't find a use of this identifier, and if the identifier
2012  // corresponds to a compiler builtin, create the decl object for the builtin
2013  // now, injecting it into translation unit scope, and return it.
2014  if (AllowBuiltinCreation && LookupBuiltin(R))
2015  return true;
2016 
2017  // If we didn't find a use of this identifier, the ExternalSource
2018  // may be able to handle the situation.
2019  // Note: some lookup failures are expected!
2020  // See e.g. R.isForRedeclaration().
2021  return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
2022 }
2023 
2024 /// Perform qualified name lookup in the namespaces nominated by
2025 /// using directives by the given context.
2026 ///
2027 /// C++98 [namespace.qual]p2:
2028 /// Given X::m (where X is a user-declared namespace), or given \::m
2029 /// (where X is the global namespace), let S be the set of all
2030 /// declarations of m in X and in the transitive closure of all
2031 /// namespaces nominated by using-directives in X and its used
2032 /// namespaces, except that using-directives are ignored in any
2033 /// namespace, including X, directly containing one or more
2034 /// declarations of m. No namespace is searched more than once in
2035 /// the lookup of a name. If S is the empty set, the program is
2036 /// ill-formed. Otherwise, if S has exactly one member, or if the
2037 /// context of the reference is a using-declaration
2038 /// (namespace.udecl), S is the required set of declarations of
2039 /// m. Otherwise if the use of m is not one that allows a unique
2040 /// declaration to be chosen from S, the program is ill-formed.
2041 ///
2042 /// C++98 [namespace.qual]p5:
2043 /// During the lookup of a qualified namespace member name, if the
2044 /// lookup finds more than one declaration of the member, and if one
2045 /// declaration introduces a class name or enumeration name and the
2046 /// other declarations either introduce the same object, the same
2047 /// enumerator or a set of functions, the non-type name hides the
2048 /// class or enumeration name if and only if the declarations are
2049 /// from the same namespace; otherwise (the declarations are from
2050 /// different namespaces), the program is ill-formed.
2052  DeclContext *StartDC) {
2053  assert(StartDC->isFileContext() && "start context is not a file context");
2054 
2055  // We have not yet looked into these namespaces, much less added
2056  // their "using-children" to the queue.
2058 
2059  // We have at least added all these contexts to the queue.
2061  Visited.insert(StartDC);
2062 
2063  // We have already looked into the initial namespace; seed the queue
2064  // with its using-children.
2065  for (auto *I : StartDC->using_directives()) {
2066  NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
2067  if (S.isVisible(I) && Visited.insert(ND).second)
2068  Queue.push_back(ND);
2069  }
2070 
2071  // The easiest way to implement the restriction in [namespace.qual]p5
2072  // is to check whether any of the individual results found a tag
2073  // and, if so, to declare an ambiguity if the final result is not
2074  // a tag.
2075  bool FoundTag = false;
2076  bool FoundNonTag = false;
2077 
2079 
2080  bool Found = false;
2081  while (!Queue.empty()) {
2082  NamespaceDecl *ND = Queue.pop_back_val();
2083 
2084  // We go through some convolutions here to avoid copying results
2085  // between LookupResults.
2086  bool UseLocal = !R.empty();
2087  LookupResult &DirectR = UseLocal ? LocalR : R;
2088  bool FoundDirect = LookupDirect(S, DirectR, ND);
2089 
2090  if (FoundDirect) {
2091  // First do any local hiding.
2092  DirectR.resolveKind();
2093 
2094  // If the local result is a tag, remember that.
2095  if (DirectR.isSingleTagDecl())
2096  FoundTag = true;
2097  else
2098  FoundNonTag = true;
2099 
2100  // Append the local results to the total results if necessary.
2101  if (UseLocal) {
2102  R.addAllDecls(LocalR);
2103  LocalR.clear();
2104  }
2105  }
2106 
2107  // If we find names in this namespace, ignore its using directives.
2108  if (FoundDirect) {
2109  Found = true;
2110  continue;
2111  }
2112 
2113  for (auto I : ND->using_directives()) {
2114  NamespaceDecl *Nom = I->getNominatedNamespace();
2115  if (S.isVisible(I) && Visited.insert(Nom).second)
2116  Queue.push_back(Nom);
2117  }
2118  }
2119 
2120  if (Found) {
2121  if (FoundTag && FoundNonTag)
2123  else
2124  R.resolveKind();
2125  }
2126 
2127  return Found;
2128 }
2129 
2130 /// Perform qualified name lookup into a given context.
2131 ///
2132 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
2133 /// names when the context of those names is explicit specified, e.g.,
2134 /// "std::vector" or "x->member", or as part of unqualified name lookup.
2135 ///
2136 /// Different lookup criteria can find different names. For example, a
2137 /// particular scope can have both a struct and a function of the same
2138 /// name, and each can be found by certain lookup criteria. For more
2139 /// information about lookup criteria, see the documentation for the
2140 /// class LookupCriteria.
2141 ///
2142 /// \param R captures both the lookup criteria and any lookup results found.
2143 ///
2144 /// \param LookupCtx The context in which qualified name lookup will
2145 /// search. If the lookup criteria permits, name lookup may also search
2146 /// in the parent contexts or (for C++ classes) base classes.
2147 ///
2148 /// \param InUnqualifiedLookup true if this is qualified name lookup that
2149 /// occurs as part of unqualified name lookup.
2150 ///
2151 /// \returns true if lookup succeeded, false if it failed.
2153  bool InUnqualifiedLookup) {
2154  assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2155 
2156  if (!R.getLookupName())
2157  return false;
2158 
2159  // Make sure that the declaration context is complete.
2160  assert((!isa<TagDecl>(LookupCtx) ||
2161  LookupCtx->isDependentContext() ||
2162  cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
2163  cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
2164  "Declaration context must already be complete!");
2165 
2166  struct QualifiedLookupInScope {
2167  bool oldVal;
2168  DeclContext *Context;
2169  // Set flag in DeclContext informing debugger that we're looking for qualified name
2170  QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2171  oldVal = ctx->setUseQualifiedLookup();
2172  }
2173  ~QualifiedLookupInScope() {
2174  Context->setUseQualifiedLookup(oldVal);
2175  }
2176  } QL(LookupCtx);
2177 
2178  if (LookupDirect(*this, R, LookupCtx)) {
2179  R.resolveKind();
2180  if (isa<CXXRecordDecl>(LookupCtx))
2181  R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2182  return true;
2183  }
2184 
2185  // Don't descend into implied contexts for redeclarations.
2186  // C++98 [namespace.qual]p6:
2187  // In a declaration for a namespace member in which the
2188  // declarator-id is a qualified-id, given that the qualified-id
2189  // for the namespace member has the form
2190  // nested-name-specifier unqualified-id
2191  // the unqualified-id shall name a member of the namespace
2192  // designated by the nested-name-specifier.
2193  // See also [class.mfct]p5 and [class.static.data]p2.
2194  if (R.isForRedeclaration())
2195  return false;
2196 
2197  // If this is a namespace, look it up in the implied namespaces.
2198  if (LookupCtx->isFileContext())
2199  return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2200 
2201  // If this isn't a C++ class, we aren't allowed to look into base
2202  // classes, we're done.
2203  CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2204  if (!LookupRec || !LookupRec->getDefinition())
2205  return false;
2206 
2207  // We're done for lookups that can never succeed for C++ classes.
2208  if (R.getLookupKind() == LookupOperatorName ||
2209  R.getLookupKind() == LookupNamespaceName ||
2210  R.getLookupKind() == LookupObjCProtocolName ||
2211  R.getLookupKind() == LookupLabel)
2212  return false;
2213 
2214  // If we're performing qualified name lookup into a dependent class,
2215  // then we are actually looking into a current instantiation. If we have any
2216  // dependent base classes, then we either have to delay lookup until
2217  // template instantiation time (at which point all bases will be available)
2218  // or we have to fail.
2219  if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2220  LookupRec->hasAnyDependentBases()) {
2222  return false;
2223  }
2224 
2225  // Perform lookup into our base classes.
2226 
2227  DeclarationName Name = R.getLookupName();
2228  unsigned IDNS = R.getIdentifierNamespace();
2229 
2230  // Look for this member in our base classes.
2231  auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier,
2232  CXXBasePath &Path) -> bool {
2233  CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
2234  // Drop leading non-matching lookup results from the declaration list so
2235  // we don't need to consider them again below.
2236  for (Path.Decls = BaseRecord->lookup(Name).begin();
2237  Path.Decls != Path.Decls.end(); ++Path.Decls) {
2238  if ((*Path.Decls)->isInIdentifierNamespace(IDNS))
2239  return true;
2240  }
2241  return false;
2242  };
2243 
2244  CXXBasePaths Paths;
2245  Paths.setOrigin(LookupRec);
2246  if (!LookupRec->lookupInBases(BaseCallback, Paths))
2247  return false;
2248 
2249  R.setNamingClass(LookupRec);
2250 
2251  // C++ [class.member.lookup]p2:
2252  // [...] If the resulting set of declarations are not all from
2253  // sub-objects of the same type, or the set has a nonstatic member
2254  // and includes members from distinct sub-objects, there is an
2255  // ambiguity and the program is ill-formed. Otherwise that set is
2256  // the result of the lookup.
2257  QualType SubobjectType;
2258  int SubobjectNumber = 0;
2259  AccessSpecifier SubobjectAccess = AS_none;
2260 
2261  // Check whether the given lookup result contains only static members.
2262  auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) {
2263  for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I)
2264  if ((*I)->isInIdentifierNamespace(IDNS) && (*I)->isCXXInstanceMember())
2265  return false;
2266  return true;
2267  };
2268 
2269  bool TemplateNameLookup = R.isTemplateNameLookup();
2270 
2271  // Determine whether two sets of members contain the same members, as
2272  // required by C++ [class.member.lookup]p6.
2273  auto HasSameDeclarations = [&](DeclContext::lookup_iterator A,
2275  using Iterator = DeclContextLookupResult::iterator;
2276  using Result = const void *;
2277 
2278  auto Next = [&](Iterator &It, Iterator End) -> Result {
2279  while (It != End) {
2280  NamedDecl *ND = *It++;
2281  if (!ND->isInIdentifierNamespace(IDNS))
2282  continue;
2283 
2284  // C++ [temp.local]p3:
2285  // A lookup that finds an injected-class-name (10.2) can result in
2286  // an ambiguity in certain cases (for example, if it is found in
2287  // more than one base class). If all of the injected-class-names
2288  // that are found refer to specializations of the same class
2289  // template, and if the name is used as a template-name, the
2290  // reference refers to the class template itself and not a
2291  // specialization thereof, and is not ambiguous.
2292  if (TemplateNameLookup)
2293  if (auto *TD = getAsTemplateNameDecl(ND))
2294  ND = TD;
2295 
2296  // C++ [class.member.lookup]p3:
2297  // type declarations (including injected-class-names) are replaced by
2298  // the types they designate
2299  if (const TypeDecl *TD = dyn_cast<TypeDecl>(ND->getUnderlyingDecl())) {
2300  QualType T = Context.getTypeDeclType(TD);
2301  return T.getCanonicalType().getAsOpaquePtr();
2302  }
2303 
2304  return ND->getUnderlyingDecl()->getCanonicalDecl();
2305  }
2306  return nullptr;
2307  };
2308 
2309  // We'll often find the declarations are in the same order. Handle this
2310  // case (and the special case of only one declaration) efficiently.
2311  Iterator AIt = A, BIt = B, AEnd, BEnd;
2312  while (true) {
2313  Result AResult = Next(AIt, AEnd);
2314  Result BResult = Next(BIt, BEnd);
2315  if (!AResult && !BResult)
2316  return true;
2317  if (!AResult || !BResult)
2318  return false;
2319  if (AResult != BResult) {
2320  // Found a mismatch; carefully check both lists, accounting for the
2321  // possibility of declarations appearing more than once.
2322  llvm::SmallDenseMap<Result, bool, 32> AResults;
2323  for (; AResult; AResult = Next(AIt, AEnd))
2324  AResults.insert({AResult, /*FoundInB*/false});
2325  unsigned Found = 0;
2326  for (; BResult; BResult = Next(BIt, BEnd)) {
2327  auto It = AResults.find(BResult);
2328  if (It == AResults.end())
2329  return false;
2330  if (!It->second) {
2331  It->second = true;
2332  ++Found;
2333  }
2334  }
2335  return AResults.size() == Found;
2336  }
2337  }
2338  };
2339 
2340  for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2341  Path != PathEnd; ++Path) {
2342  const CXXBasePathElement &PathElement = Path->back();
2343 
2344  // Pick the best (i.e. most permissive i.e. numerically lowest) access
2345  // across all paths.
2346  SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2347 
2348  // Determine whether we're looking at a distinct sub-object or not.
2349  if (SubobjectType.isNull()) {
2350  // This is the first subobject we've looked at. Record its type.
2351  SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2352  SubobjectNumber = PathElement.SubobjectNumber;
2353  continue;
2354  }
2355 
2356  if (SubobjectType !=
2357  Context.getCanonicalType(PathElement.Base->getType())) {
2358  // We found members of the given name in two subobjects of
2359  // different types. If the declaration sets aren't the same, this
2360  // lookup is ambiguous.
2361  //
2362  // FIXME: The language rule says that this applies irrespective of
2363  // whether the sets contain only static members.
2364  if (HasOnlyStaticMembers(Path->Decls) &&
2365  HasSameDeclarations(Paths.begin()->Decls, Path->Decls))
2366  continue;
2367 
2368  R.setAmbiguousBaseSubobjectTypes(Paths);
2369  return true;
2370  }
2371 
2372  // FIXME: This language rule no longer exists. Checking for ambiguous base
2373  // subobjects should be done as part of formation of a class member access
2374  // expression (when converting the object parameter to the member's type).
2375  if (SubobjectNumber != PathElement.SubobjectNumber) {
2376  // We have a different subobject of the same type.
2377 
2378  // C++ [class.member.lookup]p5:
2379  // A static member, a nested type or an enumerator defined in
2380  // a base class T can unambiguously be found even if an object
2381  // has more than one base class subobject of type T.
2382  if (HasOnlyStaticMembers(Path->Decls))
2383  continue;
2384 
2385  // We have found a nonstatic member name in multiple, distinct
2386  // subobjects. Name lookup is ambiguous.
2387  R.setAmbiguousBaseSubobjects(Paths);
2388  return true;
2389  }
2390  }
2391 
2392  // Lookup in a base class succeeded; return these results.
2393 
2394  for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end();
2395  I != E; ++I) {
2396  AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2397  (*I)->getAccess());
2398  if (NamedDecl *ND = R.getAcceptableDecl(*I))
2399  R.addDecl(ND, AS);
2400  }
2401  R.resolveKind();
2402  return true;
2403 }
2404 
2405 /// Performs qualified name lookup or special type of lookup for
2406 /// "__super::" scope specifier.
2407 ///
2408 /// This routine is a convenience overload meant to be called from contexts
2409 /// that need to perform a qualified name lookup with an optional C++ scope
2410 /// specifier that might require special kind of lookup.
2411 ///
2412 /// \param R captures both the lookup criteria and any lookup results found.
2413 ///
2414 /// \param LookupCtx The context in which qualified name lookup will
2415 /// search.
2416 ///
2417 /// \param SS An optional C++ scope-specifier.
2418 ///
2419 /// \returns true if lookup succeeded, false if it failed.
2421  CXXScopeSpec &SS) {
2422  auto *NNS = SS.getScopeRep();
2423  if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2424  return LookupInSuper(R, NNS->getAsRecordDecl());
2425  else
2426 
2427  return LookupQualifiedName(R, LookupCtx);
2428 }
2429 
2430 /// Performs name lookup for a name that was parsed in the
2431 /// source code, and may contain a C++ scope specifier.
2432 ///
2433 /// This routine is a convenience routine meant to be called from
2434 /// contexts that receive a name and an optional C++ scope specifier
2435 /// (e.g., "N::M::x"). It will then perform either qualified or
2436 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2437 /// respectively) on the given name and return those results. It will
2438 /// perform a special type of lookup for "__super::" scope specifier.
2439 ///
2440 /// @param S The scope from which unqualified name lookup will
2441 /// begin.
2442 ///
2443 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2444 ///
2445 /// @param EnteringContext Indicates whether we are going to enter the
2446 /// context of the scope-specifier SS (if present).
2447 ///
2448 /// @returns True if any decls were found (but possibly ambiguous)
2450  bool AllowBuiltinCreation, bool EnteringContext) {
2451  if (SS && SS->isInvalid()) {
2452  // When the scope specifier is invalid, don't even look for
2453  // anything.
2454  return false;
2455  }
2456 
2457  if (SS && SS->isSet()) {
2458  NestedNameSpecifier *NNS = SS->getScopeRep();
2459  if (NNS->getKind() == NestedNameSpecifier::Super)
2460  return LookupInSuper(R, NNS->getAsRecordDecl());
2461 
2462  if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2463  // We have resolved the scope specifier to a particular declaration
2464  // contex, and will perform name lookup in that context.
2465  if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2466  return false;
2467 
2468  R.setContextRange(SS->getRange());
2469  return LookupQualifiedName(R, DC);
2470  }
2471 
2472  // We could not resolve the scope specified to a specific declaration
2473  // context, which means that SS refers to an unknown specialization.
2474  // Name lookup can't find anything in this case.
2476  R.setContextRange(SS->getRange());
2477  return false;
2478  }
2479 
2480  // Perform unqualified name lookup starting in the given scope.
2481  return LookupName(R, S, AllowBuiltinCreation);
2482 }
2483 
2484 /// Perform qualified name lookup into all base classes of the given
2485 /// class.
2486 ///
2487 /// \param R captures both the lookup criteria and any lookup results found.
2488 ///
2489 /// \param Class The context in which qualified name lookup will
2490 /// search. Name lookup will search in all base classes merging the results.
2491 ///
2492 /// @returns True if any decls were found (but possibly ambiguous)
2494  // The access-control rules we use here are essentially the rules for
2495  // doing a lookup in Class that just magically skipped the direct
2496  // members of Class itself. That is, the naming class is Class, and the
2497  // access includes the access of the base.
2498  for (const auto &BaseSpec : Class->bases()) {
2499  CXXRecordDecl *RD = cast<CXXRecordDecl>(
2500  BaseSpec.getType()->castAs<RecordType>()->getDecl());
2501  LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2502  Result.setBaseObjectType(Context.getRecordType(Class));
2503  LookupQualifiedName(Result, RD);
2504 
2505  // Copy the lookup results into the target, merging the base's access into
2506  // the path access.
2507  for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2508  R.addDecl(I.getDecl(),
2509  CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2510  I.getAccess()));
2511  }
2512 
2513  Result.suppressDiagnostics();
2514  }
2515 
2516  R.resolveKind();
2517  R.setNamingClass(Class);
2518 
2519  return !R.empty();
2520 }
2521 
2522 /// Produce a diagnostic describing the ambiguity that resulted
2523 /// from name lookup.
2524 ///
2525 /// \param Result The result of the ambiguous lookup to be diagnosed.
2527  assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2528 
2529  DeclarationName Name = Result.getLookupName();
2530  SourceLocation NameLoc = Result.getNameLoc();
2531  SourceRange LookupRange = Result.getContextRange();
2532 
2533  switch (Result.getAmbiguityKind()) {
2535  CXXBasePaths *Paths = Result.getBasePaths();
2536  QualType SubobjectType = Paths->front().back().Base->getType();
2537  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2538  << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2539  << LookupRange;
2540 
2541  DeclContext::lookup_iterator Found = Paths->front().Decls;
2542  while (isa<CXXMethodDecl>(*Found) &&
2543  cast<CXXMethodDecl>(*Found)->isStatic())
2544  ++Found;
2545 
2546  Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2547  break;
2548  }
2549 
2551  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2552  << Name << LookupRange;
2553 
2554  CXXBasePaths *Paths = Result.getBasePaths();
2555  std::set<const NamedDecl *> DeclsPrinted;
2556  for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2557  PathEnd = Paths->end();
2558  Path != PathEnd; ++Path) {
2559  const NamedDecl *D = *Path->Decls;
2561  continue;
2562  if (DeclsPrinted.insert(D).second) {
2563  if (const auto *TD = dyn_cast<TypedefNameDecl>(D->getUnderlyingDecl()))
2564  Diag(D->getLocation(), diag::note_ambiguous_member_type_found)
2565  << TD->getUnderlyingType();
2566  else if (const auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
2567  Diag(D->getLocation(), diag::note_ambiguous_member_type_found)
2568  << Context.getTypeDeclType(TD);
2569  else
2570  Diag(D->getLocation(), diag::note_ambiguous_member_found);
2571  }
2572  }
2573  break;
2574  }
2575 
2577  Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2578 
2580 
2581  for (auto *D : Result)
2582  if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2583  TagDecls.insert(TD);
2584  Diag(TD->getLocation(), diag::note_hidden_tag);
2585  }
2586 
2587  for (auto *D : Result)
2588  if (!isa<TagDecl>(D))
2589  Diag(D->getLocation(), diag::note_hiding_object);
2590 
2591  // For recovery purposes, go ahead and implement the hiding.
2592  LookupResult::Filter F = Result.makeFilter();
2593  while (F.hasNext()) {
2594  if (TagDecls.count(F.next()))
2595  F.erase();
2596  }
2597  F.done();
2598  break;
2599  }
2600 
2602  Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2603 
2604  for (auto *D : Result)
2605  Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2606  break;
2607  }
2608  }
2609 }
2610 
2611 namespace {
2612  struct AssociatedLookup {
2613  AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2614  Sema::AssociatedNamespaceSet &Namespaces,
2615  Sema::AssociatedClassSet &Classes)
2616  : S(S), Namespaces(Namespaces), Classes(Classes),
2617  InstantiationLoc(InstantiationLoc) {
2618  }
2619 
2620  bool addClassTransitive(CXXRecordDecl *RD) {
2621  Classes.insert(RD);
2622  return ClassesTransitive.insert(RD);
2623  }
2624 
2625  Sema &S;
2626  Sema::AssociatedNamespaceSet &Namespaces;
2627  Sema::AssociatedClassSet &Classes;
2628  SourceLocation InstantiationLoc;
2629 
2630  private:
2631  Sema::AssociatedClassSet ClassesTransitive;
2632  };
2633 } // end anonymous namespace
2634 
2635 static void
2636 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2637 
2638 // Given the declaration context \param Ctx of a class, class template or
2639 // enumeration, add the associated namespaces to \param Namespaces as described
2640 // in [basic.lookup.argdep]p2.
2642  DeclContext *Ctx) {
2643  // The exact wording has been changed in C++14 as a result of
2644  // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
2645  // to all language versions since it is possible to return a local type
2646  // from a lambda in C++11.
2647  //
2648  // C++14 [basic.lookup.argdep]p2:
2649  // If T is a class type [...]. Its associated namespaces are the innermost
2650  // enclosing namespaces of its associated classes. [...]
2651  //
2652  // If T is an enumeration type, its associated namespace is the innermost
2653  // enclosing namespace of its declaration. [...]
2654 
2655  // We additionally skip inline namespaces. The innermost non-inline namespace
2656  // contains all names of all its nested inline namespaces anyway, so we can
2657  // replace the entire inline namespace tree with its root.
2658  while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
2659  Ctx = Ctx->getParent();
2660 
2661  Namespaces.insert(Ctx->getPrimaryContext());
2662 }
2663 
2664 // Add the associated classes and namespaces for argument-dependent
2665 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
2666 static void
2667 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2668  const TemplateArgument &Arg) {
2669  // C++ [basic.lookup.argdep]p2, last bullet:
2670  // -- [...] ;
2671  switch (Arg.getKind()) {
2673  break;
2674 
2676  // [...] the namespaces and classes associated with the types of the
2677  // template arguments provided for template type parameters (excluding
2678  // template template parameters)
2680  break;
2681 
2684  // [...] the namespaces in which any template template arguments are
2685  // defined; and the classes in which any member templates used as
2686  // template template arguments are defined.
2688  if (ClassTemplateDecl *ClassTemplate
2689  = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2690  DeclContext *Ctx = ClassTemplate->getDeclContext();
2691  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2692  Result.Classes.insert(EnclosingClass);
2693  // Add the associated namespace for this class.
2694  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2695  }
2696  break;
2697  }
2698 
2703  // [Note: non-type template arguments do not contribute to the set of
2704  // associated namespaces. ]
2705  break;
2706 
2708  for (const auto &P : Arg.pack_elements())
2710  break;
2711  }
2712 }
2713 
2714 // Add the associated classes and namespaces for argument-dependent lookup
2715 // with an argument of class type (C++ [basic.lookup.argdep]p2).
2716 static void
2717 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2718  CXXRecordDecl *Class) {
2719 
2720  // Just silently ignore anything whose name is __va_list_tag.
2721  if (Class->getDeclName() == Result.S.VAListTagName)
2722  return;
2723 
2724  // C++ [basic.lookup.argdep]p2:
2725  // [...]
2726  // -- If T is a class type (including unions), its associated
2727  // classes are: the class itself; the class of which it is a
2728  // member, if any; and its direct and indirect base classes.
2729  // Its associated namespaces are the innermost enclosing
2730  // namespaces of its associated classes.
2731 
2732  // Add the class of which it is a member, if any.
2733  DeclContext *Ctx = Class->getDeclContext();
2734  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2735  Result.Classes.insert(EnclosingClass);
2736 
2737  // Add the associated namespace for this class.
2738  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2739 
2740  // -- If T is a template-id, its associated namespaces and classes are
2741  // the namespace in which the template is defined; for member
2742  // templates, the member template's class; the namespaces and classes
2743  // associated with the types of the template arguments provided for
2744  // template type parameters (excluding template template parameters); the
2745  // namespaces in which any template template arguments are defined; and
2746  // the classes in which any member templates used as template template
2747  // arguments are defined. [Note: non-type template arguments do not
2748  // contribute to the set of associated namespaces. ]
2750  = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2751  DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2752  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2753  Result.Classes.insert(EnclosingClass);
2754  // Add the associated namespace for this class.
2755  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2756 
2757  const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2758  for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2759  addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2760  }
2761 
2762  // Add the class itself. If we've already transitively visited this class,
2763  // we don't need to visit base classes.
2764  if (!Result.addClassTransitive(Class))
2765  return;
2766 
2767  // Only recurse into base classes for complete types.
2768  if (!Result.S.isCompleteType(Result.InstantiationLoc,
2769  Result.S.Context.getRecordType(Class)))
2770  return;
2771 
2772  // Add direct and indirect base classes along with their associated
2773  // namespaces.
2775  Bases.push_back(Class);
2776  while (!Bases.empty()) {
2777  // Pop this class off the stack.
2778  Class = Bases.pop_back_val();
2779 
2780  // Visit the base classes.
2781  for (const auto &Base : Class->bases()) {
2782  const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2783  // In dependent contexts, we do ADL twice, and the first time around,
2784  // the base type might be a dependent TemplateSpecializationType, or a
2785  // TemplateTypeParmType. If that happens, simply ignore it.
2786  // FIXME: If we want to support export, we probably need to add the
2787  // namespace of the template in a TemplateSpecializationType, or even
2788  // the classes and namespaces of known non-dependent arguments.
2789  if (!BaseType)
2790  continue;
2791  CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2792  if (Result.addClassTransitive(BaseDecl)) {
2793  // Find the associated namespace for this base class.
2794  DeclContext *BaseCtx = BaseDecl->getDeclContext();
2795  CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2796 
2797  // Make sure we visit the bases of this base class.
2798  if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2799  Bases.push_back(BaseDecl);
2800  }
2801  }
2802  }
2803 }
2804 
2805 // Add the associated classes and namespaces for
2806 // argument-dependent lookup with an argument of type T
2807 // (C++ [basic.lookup.koenig]p2).
2808 static void
2809 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2810  // C++ [basic.lookup.koenig]p2:
2811  //
2812  // For each argument type T in the function call, there is a set
2813  // of zero or more associated namespaces and a set of zero or more
2814  // associated classes to be considered. The sets of namespaces and
2815  // classes is determined entirely by the types of the function
2816  // arguments (and the namespace of any template template
2817  // argument). Typedef names and using-declarations used to specify
2818  // the types do not contribute to this set. The sets of namespaces
2819  // and classes are determined in the following way:
2820 
2822  const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2823 
2824  while (true) {
2825  switch (T->getTypeClass()) {
2826 
2827 #define TYPE(Class, Base)
2828 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2829 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2830 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2831 #define ABSTRACT_TYPE(Class, Base)
2832 #include "clang/AST/TypeNodes.inc"
2833  // T is canonical. We can also ignore dependent types because
2834  // we don't need to do ADL at the definition point, but if we
2835  // wanted to implement template export (or if we find some other
2836  // use for associated classes and namespaces...) this would be
2837  // wrong.
2838  break;
2839 
2840  // -- If T is a pointer to U or an array of U, its associated
2841  // namespaces and classes are those associated with U.
2842  case Type::Pointer:
2843  T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2844  continue;
2845  case Type::ConstantArray:
2846  case Type::IncompleteArray:
2847  case Type::VariableArray:
2848  T = cast<ArrayType>(T)->getElementType().getTypePtr();
2849  continue;
2850 
2851  // -- If T is a fundamental type, its associated sets of
2852  // namespaces and classes are both empty.
2853  case Type::Builtin:
2854  break;
2855 
2856  // -- If T is a class type (including unions), its associated
2857  // classes are: the class itself; the class of which it is
2858  // a member, if any; and its direct and indirect base classes.
2859  // Its associated namespaces are the innermost enclosing
2860  // namespaces of its associated classes.
2861  case Type::Record: {
2862  CXXRecordDecl *Class =
2863  cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2864  addAssociatedClassesAndNamespaces(Result, Class);
2865  break;
2866  }
2867 
2868  // -- If T is an enumeration type, its associated namespace
2869  // is the innermost enclosing namespace of its declaration.
2870  // If it is a class member, its associated class is the
2871  // member’s class; else it has no associated class.
2872  case Type::Enum: {
2873  EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2874 
2875  DeclContext *Ctx = Enum->getDeclContext();
2876  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2877  Result.Classes.insert(EnclosingClass);
2878 
2879  // Add the associated namespace for this enumeration.
2880  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2881 
2882  break;
2883  }
2884 
2885  // -- If T is a function type, its associated namespaces and
2886  // classes are those associated with the function parameter
2887  // types and those associated with the return type.
2888  case Type::FunctionProto: {
2889  const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2890  for (const auto &Arg : Proto->param_types())
2891  Queue.push_back(Arg.getTypePtr());
2892  // fallthrough
2893  LLVM_FALLTHROUGH;
2894  }
2895  case Type::FunctionNoProto: {
2896  const FunctionType *FnType = cast<FunctionType>(T);
2897  T = FnType->getReturnType().getTypePtr();
2898  continue;
2899  }
2900 
2901  // -- If T is a pointer to a member function of a class X, its
2902  // associated namespaces and classes are those associated
2903  // with the function parameter types and return type,
2904  // together with those associated with X.
2905  //
2906  // -- If T is a pointer to a data member of class X, its
2907  // associated namespaces and classes are those associated
2908  // with the member type together with those associated with
2909  // X.
2910  case Type::MemberPointer: {
2911  const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2912 
2913  // Queue up the class type into which this points.
2914  Queue.push_back(MemberPtr->getClass());
2915 
2916  // And directly continue with the pointee type.
2917  T = MemberPtr->getPointeeType().getTypePtr();
2918  continue;
2919  }
2920 
2921  // As an extension, treat this like a normal pointer.
2922  case Type::BlockPointer:
2923  T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2924  continue;
2925 
2926  // References aren't covered by the standard, but that's such an
2927  // obvious defect that we cover them anyway.
2928  case Type::LValueReference:
2929  case Type::RValueReference:
2930  T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2931  continue;
2932 
2933  // These are fundamental types.
2934  case Type::Vector:
2935  case Type::ExtVector:
2936  case Type::ConstantMatrix:
2937  case Type::Complex:
2938  case Type::ExtInt:
2939  break;
2940 
2941  // Non-deduced auto types only get here for error cases.
2942  case Type::Auto:
2943  case Type::DeducedTemplateSpecialization:
2944  break;
2945 
2946  // If T is an Objective-C object or interface type, or a pointer to an
2947  // object or interface type, the associated namespace is the global
2948  // namespace.
2949  case Type::ObjCObject:
2950  case Type::ObjCInterface:
2951  case Type::ObjCObjectPointer:
2952  Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2953  break;
2954 
2955  // Atomic types are just wrappers; use the associations of the
2956  // contained type.
2957  case Type::Atomic:
2958  T = cast<AtomicType>(T)->getValueType().getTypePtr();
2959  continue;
2960  case Type::Pipe:
2961  T = cast<PipeType>(T)->getElementType().getTypePtr();
2962  continue;
2963  }
2964 
2965  if (Queue.empty())
2966  break;
2967  T = Queue.pop_back_val();
2968  }
2969 }
2970 
2971 /// Find the associated classes and namespaces for
2972 /// argument-dependent lookup for a call with the given set of
2973 /// arguments.
2974 ///
2975 /// This routine computes the sets of associated classes and associated
2976 /// namespaces searched by argument-dependent lookup
2977 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2979  SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2980  AssociatedNamespaceSet &AssociatedNamespaces,
2981  AssociatedClassSet &AssociatedClasses) {
2982  AssociatedNamespaces.clear();
2983  AssociatedClasses.clear();
2984 
2985  AssociatedLookup Result(*this, InstantiationLoc,
2986  AssociatedNamespaces, AssociatedClasses);
2987 
2988  // C++ [basic.lookup.koenig]p2:
2989  // For each argument type T in the function call, there is a set
2990  // of zero or more associated namespaces and a set of zero or more
2991  // associated classes to be considered. The sets of namespaces and
2992  // classes is determined entirely by the types of the function
2993  // arguments (and the namespace of any template template
2994  // argument).
2995  for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2996  Expr *Arg = Args[ArgIdx];
2997 
2998  if (Arg->getType() != Context.OverloadTy) {
3000  continue;
3001  }
3002 
3003  // [...] In addition, if the argument is the name or address of a
3004  // set of overloaded functions and/or function templates, its
3005  // associated classes and namespaces are the union of those
3006  // associated with each of the members of the set: the namespace
3007  // in which the function or function template is defined and the
3008  // classes and namespaces associated with its (non-dependent)
3009  // parameter types and return type.
3011 
3012  for (const NamedDecl *D : OE->decls()) {
3013  // Look through any using declarations to find the underlying function.
3014  const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
3015 
3016  // Add the classes and namespaces associated with the parameter
3017  // types and return type of this function.
3018  addAssociatedClassesAndNamespaces(Result, FDecl->getType());
3019  }
3020  }
3021 }
3022 
3024  SourceLocation Loc,
3025  LookupNameKind NameKind,
3026  RedeclarationKind Redecl) {
3027  LookupResult R(*this, Name, Loc, NameKind, Redecl);
3028  LookupName(R, S);
3029  return R.getAsSingle<NamedDecl>();
3030 }
3031 
3032 /// Find the protocol with the given name, if any.
3034  SourceLocation IdLoc,
3035  RedeclarationKind Redecl) {
3036  Decl *D = LookupSingleName(TUScope, II, IdLoc,
3037  LookupObjCProtocolName, Redecl);
3038  return cast_or_null<ObjCProtocolDecl>(D);
3039 }
3040 
3042  UnresolvedSetImpl &Functions) {
3043  // C++ [over.match.oper]p3:
3044  // -- The set of non-member candidates is the result of the
3045  // unqualified lookup of operator@ in the context of the
3046  // expression according to the usual rules for name lookup in
3047  // unqualified function calls (3.4.2) except that all member
3048  // functions are ignored.
3050  LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
3051  LookupName(Operators, S);
3052 
3053  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
3054  Functions.append(Operators.begin(), Operators.end());
3055 }
3056 
3059  bool ConstArg,
3060  bool VolatileArg,
3061  bool RValueThis,
3062  bool ConstThis,
3063  bool VolatileThis) {
3064  assert(CanDeclareSpecialMemberFunction(RD) &&
3065  "doing special member lookup into record that isn't fully complete");
3066  RD = RD->getDefinition();
3067  if (RValueThis || ConstThis || VolatileThis)
3068  assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
3069  "constructors and destructors always have unqualified lvalue this");
3070  if (ConstArg || VolatileArg)
3071  assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
3072  "parameter-less special members can't have qualified arguments");
3073 
3074  // FIXME: Get the caller to pass in a location for the lookup.
3075  SourceLocation LookupLoc = RD->getLocation();
3076 
3077  llvm::FoldingSetNodeID ID;
3078  ID.AddPointer(RD);
3079  ID.AddInteger(SM);
3080  ID.AddInteger(ConstArg);
3081  ID.AddInteger(VolatileArg);
3082  ID.AddInteger(RValueThis);
3083  ID.AddInteger(ConstThis);
3084  ID.AddInteger(VolatileThis);
3085 
3086  void *InsertPoint;
3088  SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
3089 
3090  // This was already cached
3091  if (Result)
3092  return *Result;
3093 
3094  Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3095  Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3096  SpecialMemberCache.InsertNode(Result, InsertPoint);
3097 
3098  if (SM == CXXDestructor) {
3099  if (RD->needsImplicitDestructor()) {
3101  DeclareImplicitDestructor(RD);
3102  });
3103  }
3104  CXXDestructorDecl *DD = RD->getDestructor();
3105  Result->setMethod(DD);
3106  Result->setKind(DD && !DD->isDeleted()
3109  return *Result;
3110  }
3111 
3112  // Prepare for overload resolution. Here we construct a synthetic argument
3113  // if necessary and make sure that implicit functions are declared.
3115  DeclarationName Name;
3116  Expr *Arg = nullptr;
3117  unsigned NumArgs;
3118 
3119  QualType ArgType = CanTy;
3120  ExprValueKind VK = VK_LValue;
3121 
3122  if (SM == CXXDefaultConstructor) {
3124  NumArgs = 0;
3125  if (RD->needsImplicitDefaultConstructor()) {
3127  DeclareImplicitDefaultConstructor(RD);
3128  });
3129  }
3130  } else {
3131  if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
3133  if (RD->needsImplicitCopyConstructor()) {
3135  DeclareImplicitCopyConstructor(RD);
3136  });
3137  }
3140  DeclareImplicitMoveConstructor(RD);
3141  });
3142  }
3143  } else {
3144  Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
3145  if (RD->needsImplicitCopyAssignment()) {
3147  DeclareImplicitCopyAssignment(RD);
3148  });
3149  }
3152  DeclareImplicitMoveAssignment(RD);
3153  });
3154  }
3155  }
3156 
3157  if (ConstArg)
3158  ArgType.addConst();
3159  if (VolatileArg)
3160  ArgType.addVolatile();
3161 
3162  // This isn't /really/ specified by the standard, but it's implied
3163  // we should be working from a PRValue in the case of move to ensure
3164  // that we prefer to bind to rvalue references, and an LValue in the
3165  // case of copy to ensure we don't bind to rvalue references.
3166  // Possibly an XValue is actually correct in the case of move, but
3167  // there is no semantic difference for class types in this restricted
3168  // case.
3170  VK = VK_LValue;
3171  else
3172  VK = VK_PRValue;
3173  }
3174 
3175  OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
3176 
3177  if (SM != CXXDefaultConstructor) {
3178  NumArgs = 1;
3179  Arg = &FakeArg;
3180  }
3181 
3182  // Create the object argument
3183  QualType ThisTy = CanTy;
3184  if (ConstThis)
3185  ThisTy.addConst();
3186  if (VolatileThis)
3187  ThisTy.addVolatile();
3188  Expr::Classification Classification =
3189  OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue)
3190  .Classify(Context);
3191 
3192  // Now we perform lookup on the name we computed earlier and do overload
3193  // resolution. Lookup is only performed directly into the class since there
3194  // will always be a (possibly implicit) declaration to shadow any others.
3196  DeclContext::lookup_result R = RD->lookup(Name);
3197 
3198  if (R.empty()) {
3199  // We might have no default constructor because we have a lambda's closure
3200  // type, rather than because there's some other declared constructor.
3201  // Every class has a copy/move constructor, copy/move assignment, and
3202  // destructor.
3203  assert(SM == CXXDefaultConstructor &&
3204  "lookup for a constructor or assignment operator was empty");
3205  Result->setMethod(nullptr);
3207  return *Result;
3208  }
3209 
3210  // Copy the candidates as our processing of them may load new declarations
3211  // from an external source and invalidate lookup_result.
3212  SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
3213 
3214  for (NamedDecl *CandDecl : Candidates) {
3215  if (CandDecl->isInvalidDecl())
3216  continue;
3217 
3218  DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
3219  auto CtorInfo = getConstructorInfo(Cand);
3220  if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
3222  AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
3223  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3224  else if (CtorInfo)
3225  AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
3226  llvm::makeArrayRef(&Arg, NumArgs), OCS,
3227  /*SuppressUserConversions*/ true);
3228  else
3229  AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
3230  /*SuppressUserConversions*/ true);
3231  } else if (FunctionTemplateDecl *Tmpl =
3232  dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
3235  Tmpl, Cand, RD, nullptr, ThisTy, Classification,
3236  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3237  else if (CtorInfo)
3239  CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
3240  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3241  else
3243  Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3244  } else {
3245  assert(isa<UsingDecl>(Cand.getDecl()) &&
3246  "illegal Kind of operator = Decl");
3247  }
3248  }
3249 
3251  switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
3252  case OR_Success:
3253  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3254  Result->setKind(SpecialMemberOverloadResult::Success);
3255  break;
3256 
3257  case OR_Deleted:
3258  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3260  break;
3261 
3262  case OR_Ambiguous:
3263  Result->setMethod(nullptr);
3264  Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3265  break;
3266 
3267  case OR_No_Viable_Function:
3268  Result->setMethod(nullptr);
3270  break;
3271  }
3272 
3273  return *Result;
3274 }
3275 
3276 /// Look up the default constructor for the given class.
3279  LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3280  false, false);
3281 
3282  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3283 }
3284 
3285 /// Look up the copying constructor for the given class.
3287  unsigned Quals) {
3288  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3289  "non-const, non-volatile qualifiers for copy ctor arg");
3292  Quals & Qualifiers::Volatile, false, false, false);
3293 
3294  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3295 }
3296 
3297 /// Look up the moving constructor for the given class.
3299  unsigned Quals) {
3302  Quals & Qualifiers::Volatile, false, false, false);
3303 
3304  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3305 }
3306 
3307 /// Look up the constructors for the given class.
3309  // If the implicit constructors have not yet been declared, do so now.
3310  if (CanDeclareSpecialMemberFunction(Class)) {
3311  runWithSufficientStackSpace(Class->getLocation(), [&] {
3312  if (Class->needsImplicitDefaultConstructor())
3313  DeclareImplicitDefaultConstructor(Class);
3314  if (Class->needsImplicitCopyConstructor())
3315  DeclareImplicitCopyConstructor(Class);
3316  if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3317  DeclareImplicitMoveConstructor(Class);
3318  });
3319  }
3320 
3323  return Class->lookup(Name);
3324 }
3325 
3326 /// Look up the copying assignment operator for the given class.
3328  unsigned Quals, bool RValueThis,
3329  unsigned ThisQuals) {
3330  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3331  "non-const, non-volatile qualifiers for copy assignment arg");
3332  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3333  "non-const, non-volatile qualifiers for copy assignment this");
3336  Quals & Qualifiers::Volatile, RValueThis,
3337  ThisQuals & Qualifiers::Const,
3338  ThisQuals & Qualifiers::Volatile);
3339 
3340  return Result.getMethod();
3341 }
3342 
3343 /// Look up the moving assignment operator for the given class.
3345  unsigned Quals,
3346  bool RValueThis,
3347  unsigned ThisQuals) {
3348  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3349  "non-const, non-volatile qualifiers for copy assignment this");
3352  Quals & Qualifiers::Volatile, RValueThis,
3353  ThisQuals & Qualifiers::Const,
3354  ThisQuals & Qualifiers::Volatile);
3355 
3356  return Result.getMethod();
3357 }
3358 
3359 /// Look for the destructor of the given class.
3360 ///
3361 /// During semantic analysis, this routine should be used in lieu of
3362 /// CXXRecordDecl::getDestructor().
3363 ///
3364 /// \returns The destructor for this class.
3366  return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3367  false, false, false,
3368  false, false).getMethod());
3369 }
3370 
3371 /// LookupLiteralOperator - Determine which literal operator should be used for
3372 /// a user-defined literal, per C++11 [lex.ext].
3373 ///
3374 /// Normal overload resolution is not used to select which literal operator to
3375 /// call for a user-defined literal. Look up the provided literal operator name,
3376 /// and filter the results to the appropriate set for the given argument types.
3379  ArrayRef<QualType> ArgTys, bool AllowRaw,
3380  bool AllowTemplate, bool AllowStringTemplatePack,
3381  bool DiagnoseMissing, StringLiteral *StringLit) {
3382  LookupName(R, S);
3383  assert(R.getResultKind() != LookupResult::Ambiguous &&
3384  "literal operator lookup can't be ambiguous");
3385 
3386  // Filter the lookup results appropriately.
3388 
3389  bool AllowCooked = true;
3390  bool FoundRaw = false;
3391  bool FoundTemplate = false;
3392  bool FoundStringTemplatePack = false;
3393  bool FoundCooked = false;
3394 
3395  while (F.hasNext()) {
3396  Decl *D = F.next();
3397  if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3398  D = USD->getTargetDecl();
3399 
3400  // If the declaration we found is invalid, skip it.
3401  if (D->isInvalidDecl()) {
3402  F.erase();
3403  continue;
3404  }
3405 
3406  bool IsRaw = false;
3407  bool IsTemplate = false;
3408  bool IsStringTemplatePack = false;
3409  bool IsCooked = false;
3410 
3411  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3412  if (FD->getNumParams() == 1 &&
3413  FD->getParamDecl(0)->getType()->getAs<PointerType>())
3414  IsRaw = true;
3415  else if (FD->getNumParams() == ArgTys.size()) {
3416  IsCooked = true;
3417  for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3418  QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3419  if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3420  IsCooked = false;
3421  break;
3422  }
3423  }
3424  }
3425  }
3426  if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3427  TemplateParameterList *Params = FD->getTemplateParameters();
3428  if (Params->size() == 1) {
3429  IsTemplate = true;
3430  if (!Params->getParam(0)->isTemplateParameterPack() && !StringLit) {
3431  // Implied but not stated: user-defined integer and floating literals
3432  // only ever use numeric literal operator templates, not templates
3433  // taking a parameter of class type.
3434  F.erase();
3435  continue;
3436  }
3437 
3438  // A string literal template is only considered if the string literal
3439  // is a well-formed template argument for the template parameter.
3440  if (StringLit) {
3441  SFINAETrap Trap(*this);
3443  TemplateArgumentLoc Arg(TemplateArgument(StringLit), StringLit);
3444  if (CheckTemplateArgument(Params->getParam(0), Arg, FD,
3445  R.getNameLoc(), R.getNameLoc(), 0,
3446  Checked) ||
3447  Trap.hasErrorOccurred())
3448  IsTemplate = false;
3449  }
3450  } else {
3451  IsStringTemplatePack = true;
3452  }
3453  }
3454 
3455  if (AllowTemplate && StringLit && IsTemplate) {
3456  FoundTemplate = true;
3457  AllowRaw = false;
3458  AllowCooked = false;
3459  AllowStringTemplatePack = false;
3460  if (FoundRaw || FoundCooked || FoundStringTemplatePack) {
3461  F.restart();
3462  FoundRaw = FoundCooked = FoundStringTemplatePack = false;
3463  }
3464  } else if (AllowCooked && IsCooked) {
3465  FoundCooked = true;
3466  AllowRaw = false;
3467  AllowTemplate = StringLit;
3468  AllowStringTemplatePack = false;
3469  if (FoundRaw || FoundTemplate || FoundStringTemplatePack) {
3470  // Go through again and remove the raw and template decls we've
3471  // already found.
3472  F.restart();
3473  FoundRaw = FoundTemplate = FoundStringTemplatePack = false;
3474  }
3475  } else if (AllowRaw && IsRaw) {
3476  FoundRaw = true;
3477  } else if (AllowTemplate && IsTemplate) {
3478  FoundTemplate = true;
3479  } else if (AllowStringTemplatePack && IsStringTemplatePack) {
3480  FoundStringTemplatePack = true;
3481  } else {
3482  F.erase();
3483  }
3484  }
3485 
3486  F.done();
3487 
3488  // Per C++20 [lex.ext]p5, we prefer the template form over the non-template
3489  // form for string literal operator templates.
3490  if (StringLit && FoundTemplate)
3491  return LOLR_Template;
3492 
3493  // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3494  // parameter type, that is used in preference to a raw literal operator
3495  // or literal operator template.
3496  if (FoundCooked)
3497  return LOLR_Cooked;
3498 
3499  // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3500  // operator template, but not both.
3501  if (FoundRaw && FoundTemplate) {
3502  Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3503  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3504  NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3505  return LOLR_Error;
3506  }
3507 
3508  if (FoundRaw)
3509  return LOLR_Raw;
3510 
3511  if (FoundTemplate)
3512  return LOLR_Template;
3513 
3514  if (FoundStringTemplatePack)
3515  return LOLR_StringTemplatePack;
3516 
3517  // Didn't find anything we could use.
3518  if (DiagnoseMissing) {
3519  Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3520  << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3521  << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3522  << (AllowTemplate || AllowStringTemplatePack);
3523  return LOLR_Error;
3524  }
3525 
3526  return LOLR_ErrorNoDiagnostic;
3527 }
3528 
3530  NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3531 
3532  // If we haven't yet seen a decl for this key, or the last decl
3533  // was exactly this one, we're done.
3534  if (Old == nullptr || Old == New) {
3535  Old = New;
3536  return;
3537  }
3538 
3539  // Otherwise, decide which is a more recent redeclaration.
3540  FunctionDecl *OldFD = Old->getAsFunction();
3541  FunctionDecl *NewFD = New->getAsFunction();
3542 
3543  FunctionDecl *Cursor = NewFD;
3544  while (true) {
3546 
3547  // If we got to the end without finding OldFD, OldFD is the newer
3548  // declaration; leave things as they are.
3549  if (!Cursor) return;
3550 
3551  // If we do find OldFD, then NewFD is newer.
3552  if (Cursor == OldFD) break;
3553 
3554  // Otherwise, keep looking.
3555  }
3556 
3557  Old = New;
3558 }
3559 
3561  ArrayRef<Expr *> Args, ADLResult &Result) {
3562  // Find all of the associated namespaces and classes based on the
3563  // arguments we have.
3564  AssociatedNamespaceSet AssociatedNamespaces;
3565  AssociatedClassSet AssociatedClasses;
3567  AssociatedNamespaces,
3568  AssociatedClasses);
3569 
3570  // C++ [basic.lookup.argdep]p3:
3571  // Let X be the lookup set produced by unqualified lookup (3.4.1)
3572  // and let Y be the lookup set produced by argument dependent
3573  // lookup (defined as follows). If X contains [...] then Y is
3574  // empty. Otherwise Y is the set of declarations found in the
3575  // namespaces associated with the argument types as described
3576  // below. The set of declarations found by the lookup of the name
3577  // is the union of X and Y.
3578  //
3579  // Here, we compute Y and add its members to the overloaded
3580  // candidate set.
3581  for (auto *NS : AssociatedNamespaces) {
3582  // When considering an associated namespace, the lookup is the
3583  // same as the lookup performed when the associated namespace is
3584  // used as a qualifier (3.4.3.2) except that:
3585  //
3586  // -- Any using-directives in the associated namespace are
3587  // ignored.
3588  //
3589  // -- Any namespace-scope friend functions declared in
3590  // associated classes are visible within their respective
3591  // namespaces even if they are not visible during an ordinary
3592  // lookup (11.4).
3593  DeclContext::lookup_result R = NS->lookup(Name);
3594  for (auto *D : R) {
3595  auto *Underlying = D;
3596  if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3597  Underlying = USD->getTargetDecl();
3598 
3599  if (!isa<FunctionDecl>(Underlying) &&
3600  !isa<FunctionTemplateDecl>(Underlying))
3601  continue;
3602 
3603  // The declaration is visible to argument-dependent lookup if either
3604  // it's ordinarily visible or declared as a friend in an associated
3605  // class.
3606  bool Visible = false;
3607  for (D = D->getMostRecentDecl(); D;
3608  D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
3610  if (isVisible(D)) {
3611  Visible = true;
3612  break;
3613  }
3614  } else if (D->getFriendObjectKind()) {
3615  auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
3616  if (AssociatedClasses.count(RD) && isVisible(D)) {
3617  Visible = true;
3618  break;
3619  }
3620  }
3621  }
3622 
3623  // FIXME: Preserve D as the FoundDecl.
3624  if (Visible)
3625  Result.insert(Underlying);
3626  }
3627  }
3628 }
3629 
3630 //----------------------------------------------------------------------------
3631 // Search for all visible declarations.
3632 //----------------------------------------------------------------------------
3634 
3635 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3636 
3637 namespace {
3638 
3639 class ShadowContextRAII;
3640 
3641 class VisibleDeclsRecord {
3642 public:
3643  /// An entry in the shadow map, which is optimized to store a
3644  /// single declaration (the common case) but can also store a list
3645  /// of declarations.
3646  typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3647 
3648 private:
3649  /// A mapping from declaration names to the declarations that have
3650  /// this name within a particular scope.
3651  typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3652 
3653  /// A list of shadow maps, which is used to model name hiding.
3654  std::list<ShadowMap> ShadowMaps;
3655 
3656  /// The declaration contexts we have already visited.
3657  llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3658 
3659  friend class ShadowContextRAII;
3660 
3661 public:
3662  /// Determine whether we have already visited this context
3663  /// (and, if not, note that we are going to visit that context now).
3664  bool visitedContext(DeclContext *Ctx) {
3665  return !VisitedContexts.insert(Ctx).second;
3666  }
3667 
3668  bool alreadyVisitedContext(DeclContext *Ctx) {
3669  return VisitedContexts.count(Ctx);
3670  }
3671 
3672  /// Determine whether the given declaration is hidden in the
3673  /// current scope.
3674  ///
3675  /// \returns the declaration that hides the given declaration, or
3676  /// NULL if no such declaration exists.
3677  NamedDecl *checkHidden(NamedDecl *ND);
3678 
3679  /// Add a declaration to the current shadow map.
3680  void add(NamedDecl *ND) {
3681  ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3682  }
3683 };
3684 
3685 /// RAII object that records when we've entered a shadow context.
3686 class ShadowContextRAII {
3687  VisibleDeclsRecord &Visible;
3688 
3689  typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3690 
3691 public:
3692  ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3693  Visible.ShadowMaps.emplace_back();
3694  }
3695 
3696  ~ShadowContextRAII() {
3697  Visible.ShadowMaps.pop_back();
3698  }
3699 };
3700 
3701 } // end anonymous namespace
3702 
3703 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3704  unsigned IDNS = ND->getIdentifierNamespace();
3705  std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3706  for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3707  SM != SMEnd; ++SM) {
3708  ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3709  if (Pos == SM->end())
3710  continue;
3711 
3712  for (auto *D : Pos->second) {
3713  // A tag declaration does not hide a non-tag declaration.
3714  if (D->hasTagIdentifierNamespace() &&
3717  continue;
3718 
3719  // Protocols are in distinct namespaces from everything else.
3721  || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3722  D->getIdentifierNamespace() != IDNS)
3723  continue;
3724 
3725  // Functions and function templates in the same scope overload
3726  // rather than hide. FIXME: Look for hiding based on function
3727  // signatures!
3730  SM == ShadowMaps.rbegin())
3731  continue;
3732 
3733  // A shadow declaration that's created by a resolved using declaration
3734  // is not hidden by the same using declaration.
3735  if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3736  cast<UsingShadowDecl>(ND)->getIntroducer() == D)
3737  continue;
3738 
3739  // We've found a declaration that hides this one.
3740  return D;
3741  }
3742  }
3743 
3744  return nullptr;
3745 }
3746 
3747 namespace {
3748 class LookupVisibleHelper {
3749 public:
3750  LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
3751  bool LoadExternal)
3752  : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
3753  LoadExternal(LoadExternal) {}
3754 
3755  void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind,
3756  bool IncludeGlobalScope) {
3757  // Determine the set of using directives available during
3758  // unqualified name lookup.
3759  Scope *Initial = S;
3760  UnqualUsingDirectiveSet UDirs(SemaRef);
3761  if (SemaRef.getLangOpts().CPlusPlus) {
3762  // Find the first namespace or translation-unit scope.
3763  while (S && !isNamespaceOrTranslationUnitScope(S))
3764  S = S->getParent();
3765 
3766  UDirs.visitScopeChain(Initial, S);
3767  }
3768  UDirs.done();
3769 
3770  // Look for visible declarations.
3771  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3772  Result.setAllowHidden(Consumer.includeHiddenDecls());
3773  if (!IncludeGlobalScope)
3774  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3775  ShadowContextRAII Shadow(Visited);
3776  lookupInScope(Initial, Result, UDirs);
3777  }
3778 
3779  void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
3780  Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
3781  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3782  Result.setAllowHidden(Consumer.includeHiddenDecls());
3783  if (!IncludeGlobalScope)
3784  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3785 
3786  ShadowContextRAII Shadow(Visited);
3787  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
3788  /*InBaseClass=*/false);
3789  }
3790 
3791 private:
3792  void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
3793  bool QualifiedNameLookup, bool InBaseClass) {
3794  if (!Ctx)
3795  return;
3796 
3797  // Make sure we don't visit the same context twice.
3798  if (Visited.visitedContext(Ctx->getPrimaryContext()))
3799  return;
3800 
3801  Consumer.EnteredContext(Ctx);
3802 
3803  // Outside C++, lookup results for the TU live on identifiers.
3804  if (isa<TranslationUnitDecl>(Ctx) &&
3805  !Result.getSema().getLangOpts().CPlusPlus) {
3806  auto &S = Result.getSema();
3807  auto &Idents = S.Context.Idents;
3808 
3809  // Ensure all external identifiers are in the identifier table.
3810  if (LoadExternal)
3811  if (IdentifierInfoLookup *External =
3812  Idents.getExternalIdentifierLookup()) {
3813  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3814  for (StringRef Name = Iter->Next(); !Name.empty();
3815  Name = Iter->Next())
3816  Idents.get(Name);
3817  }
3818 
3819  // Walk all lookup results in the TU for each identifier.
3820  for (const auto &Ident : Idents) {
3821  for (auto I = S.IdResolver.begin(Ident.getValue()),
3822  E = S.IdResolver.end();
3823  I != E; ++I) {
3824  if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3825  if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3826  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3827  Visited.add(ND);
3828  }
3829  }
3830  }
3831  }
3832 
3833  return;
3834  }
3835 
3836  if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3837  Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3838 
3839  llvm::SmallVector<NamedDecl *, 4> DeclsToVisit;
3840  // We sometimes skip loading namespace-level results (they tend to be huge).
3841  bool Load = LoadExternal ||
3842  !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
3843  // Enumerate all of the results in this context.
3844  for (DeclContextLookupResult R :
3845  Load ? Ctx->lookups()
3846  : Ctx->noload_lookups(/*PreserveInternalState=*/false)) {
3847  for (auto *D : R) {
3848  if (auto *ND = Result.getAcceptableDecl(D)) {
3849  // Rather than visit immediately, we put ND into a vector and visit
3850  // all decls, in order, outside of this loop. The reason is that
3851  // Consumer.FoundDecl() may invalidate the iterators used in the two
3852  // loops above.
3853  DeclsToVisit.push_back(ND);
3854  }
3855  }
3856  }
3857 
3858  for (auto *ND : DeclsToVisit) {
3859  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3860  Visited.add(ND);
3861  }
3862  DeclsToVisit.clear();
3863 
3864  // Traverse using directives for qualified name lookup.
3865  if (QualifiedNameLookup) {
3866  ShadowContextRAII Shadow(Visited);
3867  for (auto I : Ctx->using_directives()) {
3868  if (!Result.getSema().isVisible(I))
3869  continue;
3870  lookupInDeclContext(I->getNominatedNamespace(), Result,
3871  QualifiedNameLookup, InBaseClass);
3872  }
3873  }
3874 
3875  // Traverse the contexts of inherited C++ classes.
3876  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3877  if (!Record->hasDefinition())
3878  return;
3879 
3880  for (const auto &B : Record->bases()) {
3881  QualType BaseType = B.getType();
3882 
3883  RecordDecl *RD;
3884  if (BaseType->isDependentType()) {
3885  if (!IncludeDependentBases) {
3886  // Don't look into dependent bases, because name lookup can't look
3887  // there anyway.
3888  continue;
3889  }
3890  const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3891  if (!TST)
3892  continue;
3893  TemplateName TN = TST->getTemplateName();
3894  const auto *TD =
3895  dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3896  if (!TD)
3897  continue;
3898  RD = TD->getTemplatedDecl();
3899  } else {
3900  const auto *Record = BaseType->getAs<RecordType>();
3901  if (!Record)
3902  continue;
3903  RD = Record->getDecl();
3904  }
3905 
3906  // FIXME: It would be nice to be able to determine whether referencing
3907  // a particular member would be ambiguous. For example, given
3908  //
3909  // struct A { int member; };
3910  // struct B { int member; };
3911  // struct C : A, B { };
3912  //
3913  // void f(C *c) { c->### }
3914  //
3915  // accessing 'member' would result in an ambiguity. However, we
3916  // could be smart enough to qualify the member with the base
3917  // class, e.g.,
3918  //
3919  // c->B::member
3920  //
3921  // or
3922  //
3923  // c->A::member
3924 
3925  // Find results in this base class (and its bases).
3926  ShadowContextRAII Shadow(Visited);
3927  lookupInDeclContext(RD, Result, QualifiedNameLookup,
3928  /*InBaseClass=*/true);
3929  }
3930  }
3931 
3932  // Traverse the contexts of Objective-C classes.
3933  if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3934  // Traverse categories.
3935  for (auto *Cat : IFace->visible_categories()) {
3936  ShadowContextRAII Shadow(Visited);
3937  lookupInDeclContext(Cat, Result, QualifiedNameLookup,
3938  /*InBaseClass=*/false);
3939  }
3940 
3941  // Traverse protocols.
3942  for (auto *I : IFace->all_referenced_protocols()) {
3943  ShadowContextRAII Shadow(Visited);
3944  lookupInDeclContext(I, Result, QualifiedNameLookup,
3945  /*InBaseClass=*/false);
3946  }
3947 
3948  // Traverse the superclass.
3949  if (IFace->getSuperClass()) {
3950  ShadowContextRAII Shadow(Visited);
3951  lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup,
3952  /*InBaseClass=*/true);
3953  }
3954 
3955  // If there is an implementation, traverse it. We do this to find
3956  // synthesized ivars.
3957  if (IFace->getImplementation()) {
3958  ShadowContextRAII Shadow(Visited);
3959  lookupInDeclContext(IFace->getImplementation(), Result,
3960  QualifiedNameLookup, InBaseClass);
3961  }
3962  } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3963  for (auto *I : Protocol->protocols()) {
3964  ShadowContextRAII Shadow(Visited);
3965  lookupInDeclContext(I, Result, QualifiedNameLookup,
3966  /*InBaseClass=*/false);
3967  }
3968  } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3969  for (auto *I : Category->protocols()) {
3970  ShadowContextRAII Shadow(Visited);
3971  lookupInDeclContext(I, Result, QualifiedNameLookup,
3972  /*InBaseClass=*/false);
3973  }
3974 
3975  // If there is an implementation, traverse it.
3976  if (Category->getImplementation()) {
3977  ShadowContextRAII Shadow(Visited);
3978  lookupInDeclContext(Category->getImplementation(), Result,
3979  QualifiedNameLookup, /*InBaseClass=*/true);
3980  }
3981  }
3982  }
3983 
3984  void lookupInScope(Scope *S, LookupResult &Result,
3985  UnqualUsingDirectiveSet &UDirs) {
3986  // No clients run in this mode and it's not supported. Please add tests and
3987  // remove the assertion if you start relying on it.
3988  assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
3989 
3990  if (!S)
3991  return;
3992 
3993  if (!S->getEntity() ||
3994  (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) ||
3995  (S->getEntity())->isFunctionOrMethod()) {
3996  FindLocalExternScope FindLocals(Result);
3997  // Walk through the declarations in this Scope. The consumer might add new
3998  // decls to the scope as part of deserialization, so make a copy first.
3999  SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
4000  for (Decl *D : ScopeDecls) {
4001  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
4002  if ((ND = Result.getAcceptableDecl(ND))) {
4003  Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
4004  Visited.add(ND);
4005  }
4006  }
4007  }
4008 
4009  DeclContext *Entity = S->getLookupEntity();
4010  if (Entity) {
4011  // Look into this scope's declaration context, along with any of its
4012  // parent lookup contexts (e.g., enclosing classes), up to the point
4013  // where we hit the context stored in the next outer scope.
4014  DeclContext *OuterCtx = findOuterContext(S);
4015 
4016  for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
4017  Ctx = Ctx->getLookupParent()) {
4018  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
4019  if (Method->isInstanceMethod()) {
4020  // For instance methods, look for ivars in the method's interface.
4021  LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
4022  Result.getNameLoc(),
4024  if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
4025  lookupInDeclContext(IFace, IvarResult,
4026  /*QualifiedNameLookup=*/false,
4027  /*InBaseClass=*/false);
4028  }
4029  }
4030 
4031  // We've already performed all of the name lookup that we need
4032  // to for Objective-C methods; the next context will be the
4033  // outer scope.
4034  break;
4035  }
4036 
4037  if (Ctx->isFunctionOrMethod())
4038  continue;
4039 
4040  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
4041  /*InBaseClass=*/false);
4042  }
4043  } else if (!S->getParent()) {
4044  // Look into the translation unit scope. We walk through the translation
4045  // unit's declaration context, because the Scope itself won't have all of
4046  // the declarations if we loaded a precompiled header.
4047  // FIXME: We would like the translation unit's Scope object to point to
4048  // the translation unit, so we don't need this special "if" branch.
4049  // However, doing so would force the normal C++ name-lookup code to look
4050  // into the translation unit decl when the IdentifierInfo chains would
4051  // suffice. Once we fix that problem (which is part of a more general
4052  // "don't look in DeclContexts unless we have to" optimization), we can
4053  // eliminate this.
4054  Entity = Result.getSema().Context.getTranslationUnitDecl();
4055  lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false,
4056  /*InBaseClass=*/false);
4057  }
4058 
4059  if (Entity) {
4060  // Lookup visible declarations in any namespaces found by using
4061  // directives.
4062  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
4063  lookupInDeclContext(
4064  const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
4065  /*QualifiedNameLookup=*/false,
4066  /*InBaseClass=*/false);
4067  }
4068 
4069  // Lookup names in the parent scope.
4070  ShadowContextRAII Shadow(Visited);
4071  lookupInScope(S->getParent(), Result, UDirs);
4072  }
4073 
4074 private:
4075  VisibleDeclsRecord Visited;
4076  VisibleDeclConsumer &Consumer;
4077  bool IncludeDependentBases;
4078  bool LoadExternal;
4079 };
4080 } // namespace
4081 
4083  VisibleDeclConsumer &Consumer,
4084  bool IncludeGlobalScope, bool LoadExternal) {
4085  LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
4086  LoadExternal);
4087  H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope);
4088 }
4089 
4091  VisibleDeclConsumer &Consumer,
4092  bool IncludeGlobalScope,
4093  bool IncludeDependentBases, bool LoadExternal) {
4094  LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
4095  H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope);
4096 }
4097 
4098 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
4099 /// If GnuLabelLoc is a valid source location, then this is a definition
4100 /// of an __label__ label name, otherwise it is a normal label definition
4101 /// or use.
4103  SourceLocation GnuLabelLoc) {
4104  // Do a lookup to see if we have a label with this name already.
4105  NamedDecl *Res = nullptr;
4106 
4107  if (GnuLabelLoc.isValid()) {
4108  // Local label definitions always shadow existing labels.
4109  Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
4110  Scope *S = CurScope;
4111  PushOnScopeChains(Res, S, true);
4112  return cast<LabelDecl>(Res);
4113  }
4114 
4115  // Not a GNU local label.
4116  Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
4117  // If we found a label, check to see if it is in the same context as us.
4118  // When in a Block, we don't want to reuse a label in an enclosing function.
4119  if (Res && Res->getDeclContext() != CurContext)
4120  Res = nullptr;
4121  if (!Res) {
4122  // If not forward referenced or defined already, create the backing decl.
4123  Res = LabelDecl::Create(Context, CurContext, Loc, II);
4124  Scope *S = CurScope->getFnParent();
4125  assert(S && "Not in a function?");
4126  PushOnScopeChains(Res, S, true);
4127  }
4128  return cast<LabelDecl>(Res);
4129 }
4130 
4131 //===----------------------------------------------------------------------===//
4132 // Typo correction
4133 //===----------------------------------------------------------------------===//
4134 
4136  TypoCorrection &Candidate) {
4137  Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
4138  return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
4139 }
4140 
4141 static void LookupPotentialTypoResult(Sema &SemaRef,
4142  LookupResult &Res,
4143  IdentifierInfo *Name,
4144  Scope *S, CXXScopeSpec *SS,
4145  DeclContext *MemberContext,
4146  bool EnteringContext,
4147  bool isObjCIvarLookup,
4148  bool FindHidden);
4149 
4150 /// Check whether the declarations found for a typo correction are
4151 /// visible. Set the correction's RequiresImport flag to true if none of the
4152 /// declarations are visible, false otherwise.
4153 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4154  TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4155 
4156  for (/**/; DI != DE; ++DI)
4157  if (!LookupResult::isVisible(SemaRef, *DI))
4158  break;
4159  // No filtering needed if all decls are visible.
4160  if (DI == DE) {
4161  TC.setRequiresImport(false);
4162  return;
4163  }
4164 
4165  llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4166  bool AnyVisibleDecls = !NewDecls.empty();
4167 
4168  for (/**/; DI != DE; ++DI) {
4169  if (LookupResult::isVisible(SemaRef, *DI)) {
4170  if (!AnyVisibleDecls) {
4171  // Found a visible decl, discard all hidden ones.
4172  AnyVisibleDecls = true;
4173  NewDecls.clear();
4174  }
4175  NewDecls.push_back(*DI);
4176  } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4177  NewDecls.push_back(*DI);
4178  }
4179 
4180  if (NewDecls.empty())
4181  TC = TypoCorrection();
4182  else {
4183  TC.setCorrectionDecls(NewDecls);
4184  TC.setRequiresImport(!AnyVisibleDecls);
4185  }
4186 }
4187 
4188 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
4189 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4190 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4192  NestedNameSpecifier *NNS,
4194  if (NestedNameSpecifier *Prefix = NNS->getPrefix())
4195  getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
4196  else
4197  Identifiers.clear();
4198 
4199  const IdentifierInfo *II = nullptr;
4200 
4201  switch (NNS->getKind()) {
4203  II = NNS->getAsIdentifier();
4204  break;
4205 
4207  if (NNS->getAsNamespace()->isAnonymousNamespace())
4208  return;
4209  II = NNS->getAsNamespace()->getIdentifier();
4210  break;
4211 
4213  II = NNS->getAsNamespaceAlias()->getIdentifier();
4214  break;
4215 
4218  II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
4219  break;
4220 
4223  return;
4224  }
4225 
4226  if (II)
4227  Identifiers.push_back(II);
4228 }
4229 
4231  DeclContext *Ctx, bool InBaseClass) {
4232  // Don't consider hidden names for typo correction.
4233  if (Hiding)
4234  return;
4235 
4236  // Only consider entities with identifiers for names, ignoring
4237  // special names (constructors, overloaded operators, selectors,
4238  // etc.).
4239  IdentifierInfo *Name = ND->getIdentifier();
4240  if (!Name)
4241  return;
4242 
4243  // Only consider visible declarations and declarations from modules with
4244  // names that exactly match.
4245  if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
4246  return;
4247 
4248  FoundName(Name->getName());
4249 }
4250 
4252  // Compute the edit distance between the typo and the name of this
4253  // entity, and add the identifier to the list of results.
4254  addName(Name, nullptr);
4255 }
4256 
4258  // Compute the edit distance between the typo and this keyword,
4259  // and add the keyword to the list of results.
4260  addName(Keyword, nullptr, nullptr, true);
4261 }
4262 
4263 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4264  NestedNameSpecifier *NNS, bool isKeyword) {
4265  // Use a simple length-based heuristic to determine the minimum possible
4266  // edit distance. If the minimum isn't good enough, bail out early.
4267  StringRef TypoStr = Typo->getName();
4268  unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
4269  if (MinED && TypoStr.size() / MinED < 3)
4270  return;
4271 
4272  // Compute an upper bound on the allowable edit distance, so that the
4273  // edit-distance algorithm can short-circuit.
4274  unsigned UpperBound = (TypoStr.size() + 2) / 3;
4275  unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
4276  if (ED > UpperBound) return;
4277 
4278  TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4279  if (isKeyword) TC.makeKeyword();
4280  TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
4281  addCorrection(TC);
4282 }
4283 
4284 static const unsigned MaxTypoDistanceResultSets = 5;
4285 
4287  StringRef TypoStr = Typo->getName();
4288  StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4289 
4290  // For very short typos, ignore potential corrections that have a different
4291  // base identifier from the typo or which have a normalized edit distance
4292  // longer than the typo itself.
4293  if (TypoStr.size() < 3 &&
4294  (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4295  return;
4296 
4297  // If the correction is resolved but is not viable, ignore it.
4298  if (Correction.isResolved()) {
4299  checkCorrectionVisibility(SemaRef, Correction);
4300  if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4301  return;
4302  }
4303 
4304  TypoResultList &CList =
4305  CorrectionResults[Correction.getEditDistance(false)][Name];
4306 
4307  if (!CList.empty() && !CList.back().isResolved())
4308  CList.pop_back();
4309  if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4310  std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4311  for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4312  RI != RIEnd; ++RI) {
4313  // If the Correction refers to a decl already in the result list,
4314  // replace the existing result if the string representation of Correction
4315  // comes before the current result alphabetically, then stop as there is
4316  // nothing more to be done to add Correction to the candidate set.
4317  if (RI->getCorrectionDecl() == NewND) {
4318  if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4319  *RI = Correction;
4320  return;
4321  }
4322  }
4323  }
4324  if (CList.empty() || Correction.isResolved())
4325  CList.push_back(Correction);
4326 
4327  while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4328  CorrectionResults.erase(std::prev(CorrectionResults.end()));
4329 }
4330 
4332  const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4333  SearchNamespaces = true;
4334 
4335  for (auto KNPair : KnownNamespaces)
4336  Namespaces.addNameSpecifier(KNPair.first);
4337 
4338  bool SSIsTemplate = false;
4339  if (NestedNameSpecifier *NNS =
4340  (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4341  if (const Type *T = NNS->getAsType())
4342  SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4343  }
4344  // Do not transform this into an iterator-based loop. The loop body can
4345  // trigger the creation of further types (through lazy deserialization) and
4346  // invalid iterators into this list.
4347  auto &Types = SemaRef.getASTContext().getTypes();
4348  for (unsigned I = 0; I != Types.size(); ++I) {
4349  const auto *TI = Types[I];
4350  if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4351  CD = CD->getCanonicalDecl();
4352  if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4353  !CD->isUnion() && CD->getIdentifier() &&
4354  (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4355  (CD->isBeingDefined() || CD->isCompleteDefinition()))
4356  Namespaces.addNameSpecifier(CD);
4357  }
4358  }
4359 }
4360 
4362  if (++CurrentTCIndex < ValidatedCorrections.size())
4363  return ValidatedCorrections[CurrentTCIndex];
4364 
4365  CurrentTCIndex = ValidatedCorrections.size();
4366  while (!CorrectionResults.empty()) {
4367  auto DI = CorrectionResults.begin();
4368  if (DI->second.empty()) {
4369  CorrectionResults.erase(DI);
4370  continue;
4371  }
4372 
4373  auto RI = DI->second.begin();
4374  if (RI->second.empty()) {
4375  DI->second.erase(RI);
4376  performQualifiedLookups();
4377  continue;
4378  }
4379 
4380  TypoCorrection TC = RI->second.pop_back_val();
4381  if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4382  ValidatedCorrections.push_back(TC);
4383  return ValidatedCorrections[CurrentTCIndex];
4384  }
4385  }
4386  return ValidatedCorrections[0]; // The empty correction.
4387 }
4388 
4389 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4390  IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4391  DeclContext *TempMemberContext = MemberContext;
4392  CXXScopeSpec *TempSS = SS.get();
4393 retry_lookup:
4394  LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4395  EnteringContext,
4396  CorrectionValidator->IsObjCIvarLookup,
4397  Name == Typo && !Candidate.WillReplaceSpecifier());
4398  switch (Result.getResultKind()) {
4402  if (TempSS) {
4403  // Immediately retry the lookup without the given CXXScopeSpec
4404  TempSS = nullptr;
4405  Candidate.WillReplaceSpecifier(true);
4406  goto retry_lookup;
4407  }
4408  if (TempMemberContext) {
4409  if (SS && !TempSS)
4410  TempSS = SS.get();
4411  TempMemberContext = nullptr;
4412  goto retry_lookup;
4413  }
4414  if (SearchNamespaces)
4415  QualifiedResults.push_back(Candidate);
4416  break;
4417 
4419  // We don't deal with ambiguities.
4420  break;
4421 
4422  case LookupResult::Found:
4424  // Store all of the Decls for overloaded symbols
4425  for (auto *TRD : Result)
4426  Candidate.addCorrectionDecl(TRD);
4427  checkCorrectionVisibility(SemaRef, Candidate);
4428  if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4429  if (SearchNamespaces)
4430  QualifiedResults.push_back(Candidate);
4431  break;
4432  }
4433  Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4434  return true;
4435  }
4436  return false;
4437 }
4438 
4439 void TypoCorrectionConsumer::performQualifiedLookups() {
4440  unsigned TypoLen = Typo->getName().size();
4441  for (const TypoCorrection &QR : QualifiedResults) {
4442  for (const auto &NSI : Namespaces) {
4443  DeclContext *Ctx = NSI.DeclCtx;
4444  const Type *NSType = NSI.NameSpecifier->getAsType();
4445 
4446  // If the current NestedNameSpecifier refers to a class and the
4447  // current correction candidate is the name of that class, then skip
4448  // it as it is unlikely a qualified version of the class' constructor
4449  // is an appropriate correction.
4450  if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4451  nullptr) {
4452  if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4453  continue;
4454  }
4455 
4456  TypoCorrection TC(QR);
4457  TC.ClearCorrectionDecls();
4458  TC.setCorrectionSpecifier(NSI.NameSpecifier);
4459  TC.setQualifierDistance(NSI.EditDistance);
4460  TC.setCallbackDistance(0); // Reset the callback distance
4461 
4462  // If the current correction candidate and namespace combination are
4463  // too far away from the original typo based on the normalized edit
4464  // distance, then skip performing a qualified name lookup.
4465  unsigned TmpED = TC.getEditDistance(true);
4466  if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4467  TypoLen / TmpED < 3)
4468  continue;
4469 
4470  Result.clear();
4471  Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4472  if (!SemaRef.LookupQualifiedName(Result, Ctx))
4473  continue;
4474 
4475  // Any corrections added below will be validated in subsequent
4476  // iterations of the main while() loop over the Consumer's contents.
4477  switch (Result.getResultKind()) {
4478  case LookupResult::Found:
4480  if (SS && SS->isValid()) {
4481  std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4482  std::string OldQualified;
4483  llvm::raw_string_ostream OldOStream(OldQualified);
4484  SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4485  OldOStream << Typo->getName();
4486  // If correction candidate would be an identical written qualified
4487  // identifier, then the existing CXXScopeSpec probably included a
4488  // typedef that didn't get accounted for properly.
4489  if (OldOStream.str() == NewQualified)
4490  break;
4491  }
4492  for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4493  TRD != TRDEnd; ++TRD) {
4494  if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4495  NSType ? NSType->getAsCXXRecordDecl()
4496  : nullptr,
4497  TRD.getPair()) == Sema::AR_accessible)
4498  TC.addCorrectionDecl(*TRD);
4499  }
4500  if (TC.isResolved()) {
4501  TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4502  addCorrection(TC);
4503  }
4504  break;
4505  }
4510  break;
4511  }
4512  }
4513  }
4514  QualifiedResults.clear();
4515 }
4516 
4517 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4518  ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4519  : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4520  if (NestedNameSpecifier *NNS =
4521  CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4522  llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4523  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4524 
4525  getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4526  }
4527  // Build the list of identifiers that would be used for an absolute
4528  // (from the global context) NestedNameSpecifier referring to the current
4529  // context.
4530  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4531  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4532  CurContextIdentifiers.push_back(ND->getIdentifier());
4533  }
4534 
4535  // Add the global context as a NestedNameSpecifier
4536  SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4538  DistanceMap[1].push_back(SI);
4539 }
4540 
4541 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4542  DeclContext *Start) -> DeclContextList {
4543  assert(Start && "Building a context chain from a null context");
4544  DeclContextList Chain;
4545  for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4546  DC = DC->getLookupParent()) {
4547  NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4548  if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4549  !(ND && ND->isAnonymousNamespace()))
4550  Chain.push_back(DC->getPrimaryContext());
4551  }
4552  return Chain;
4553 }
4554 
4555 unsigned
4556 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4557  DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4558  unsigned NumSpecifiers = 0;
4559  for (DeclContext *C : llvm::reverse(DeclChain)) {
4560  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4561  NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4562  ++NumSpecifiers;
4563  } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4564  NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4565  RD->getTypeForDecl());
4566  ++NumSpecifiers;
4567  }
4568  }
4569  return NumSpecifiers;
4570 }
4571 
4572 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4573  DeclContext *Ctx) {
4574  NestedNameSpecifier *NNS = nullptr;
4575  unsigned NumSpecifiers = 0;
4576  DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4577  DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4578 
4579  // Eliminate common elements from the two DeclContext chains.
4580  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4581  if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4582  break;
4583  NamespaceDeclChain.pop_back();
4584  }
4585 
4586  // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4587  NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4588 
4589  // Add an explicit leading '::' specifier if needed.
4590  if (NamespaceDeclChain.empty()) {
4591  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4592  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4593  NumSpecifiers =
4594  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4595  } else if (NamedDecl *ND =
4596  dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4597  IdentifierInfo *Name = ND->getIdentifier();
4598  bool SameNameSpecifier = false;
4599  if (llvm::is_contained(CurNameSpecifierIdentifiers, Name)) {
4600  std::string NewNameSpecifier;
4601  llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4602  SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4603  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4604  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4605  SpecifierOStream.flush();
4606  SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4607  }
4608  if (SameNameSpecifier || llvm::is_contained(CurContextIdentifiers, Name)) {
4609  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4610  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4611  NumSpecifiers =
4612  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4613  }
4614  }
4615 
4616  // If the built NestedNameSpecifier would be replacing an existing
4617  // NestedNameSpecifier, use the number of component identifiers that
4618  // would need to be changed as the edit distance instead of the number
4619  // of components in the built NestedNameSpecifier.
4620  if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4621  SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4622  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4623  NumSpecifiers = llvm::ComputeEditDistance(
4624  llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4625  llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4626  }
4627 
4628  SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4629  DistanceMap[NumSpecifiers].push_back(SI);
4630 }
4631 
4632 /// Perform name lookup for a possible result for typo correction.
4633 static void LookupPotentialTypoResult(Sema &SemaRef,
4634  LookupResult &Res,
4635  IdentifierInfo *Name,
4636  Scope *S, CXXScopeSpec *SS,
4637  DeclContext *MemberContext,
4638  bool EnteringContext,
4639  bool isObjCIvarLookup,
4640  bool FindHidden) {
4641  Res.suppressDiagnostics();
4642  Res.clear();
4643  Res.setLookupName(Name);
4644  Res.setAllowHidden(FindHidden);
4645  if (MemberContext) {
4646  if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4647  if (isObjCIvarLookup) {
4648  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4649  Res.addDecl(Ivar);
4650  Res.resolveKind();
4651  return;
4652  }
4653  }
4654 
4655  if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4657  Res.addDecl(Prop);
4658  Res.resolveKind();
4659  return;
4660  }
4661  }
4662 
4663  SemaRef.LookupQualifiedName(Res, MemberContext);
4664  return;
4665  }
4666 
4667  SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4668  EnteringContext);
4669 
4670  // Fake ivar lookup; this should really be part of
4671  // LookupParsedName.
4672  if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4673  if (Method->isInstanceMethod() && Method->getClassInterface() &&
4674  (Res.empty() ||
4675  (Res.isSingleResult() &&
4677  if (ObjCIvarDecl *IV
4678  = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4679  Res.addDecl(IV);
4680  Res.resolveKind();
4681  }
4682  }
4683  }
4684 }
4685 
4686 /// Add keywords to the consumer as possible typo corrections.
4687 static void AddKeywordsToConsumer(Sema &SemaRef,
4688  TypoCorrectionConsumer &Consumer,
4690  bool AfterNestedNameSpecifier) {
4691  if (AfterNestedNameSpecifier) {
4692  // For 'X::', we know exactly which keywords can appear next.
4693  Consumer.addKeywordResult("template");
4694  if (CCC.WantExpressionKeywords)
4695  Consumer.addKeywordResult("operator");
4696  return;
4697  }
4698 
4699  if (CCC.WantObjCSuper)
4700  Consumer.addKeywordResult("super");
4701 
4702  if (CCC.WantTypeSpecifiers) {
4703  // Add type-specifier keywords to the set of results.
4704  static const char *const CTypeSpecs[] = {
4705  "char", "const", "double", "enum", "float", "int", "long", "short",
4706  "signed", "struct", "union", "unsigned", "void", "volatile",
4707  "_Complex", "_Imaginary",
4708  // storage-specifiers as well
4709  "extern", "inline", "static", "typedef"
4710  };
4711 
4712  const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4713  for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4714  Consumer.addKeywordResult(CTypeSpecs[I]);
4715 
4716  if (SemaRef.getLangOpts().C99)
4717  Consumer.addKeywordResult("restrict");
4718  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4719  Consumer.addKeywordResult("bool");
4720  else if (SemaRef.getLangOpts().C99)
4721  Consumer.addKeywordResult("_Bool");
4722 
4723  if (SemaRef.getLangOpts().CPlusPlus) {
4724  Consumer.addKeywordResult("class");
4725  Consumer.addKeywordResult("typename");
4726  Consumer.addKeywordResult("wchar_t");
4727 
4728  if (SemaRef.getLangOpts().CPlusPlus11) {
4729  Consumer.addKeywordResult("char16_t");
4730  Consumer.addKeywordResult("char32_t");
4731  Consumer.addKeywordResult("constexpr");
4732  Consumer.addKeywordResult("decltype");
4733  Consumer.addKeywordResult("thread_local");
4734  }
4735  }
4736 
4737  if (SemaRef.getLangOpts().GNUKeywords)
4738  Consumer.addKeywordResult("typeof");
4739  } else if (CCC.WantFunctionLikeCasts) {
4740  static const char *const CastableTypeSpecs[] = {
4741  "char", "double", "float", "int", "long", "short",
4742  "signed", "unsigned", "void"
4743  };
4744  for (auto *kw : CastableTypeSpecs)
4745  Consumer.addKeywordResult(kw);
4746  }
4747 
4748  if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4749  Consumer.addKeywordResult("const_cast");
4750  Consumer.addKeywordResult("dynamic_cast");
4751  Consumer.addKeywordResult("reinterpret_cast");
4752  Consumer.addKeywordResult("static_cast");
4753  }
4754 
4755  if (CCC.WantExpressionKeywords) {
4756  Consumer.addKeywordResult("sizeof");
4757  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4758  Consumer.addKeywordResult("false");
4759  Consumer.addKeywordResult("true");
4760  }
4761 
4762  if (SemaRef.getLangOpts().CPlusPlus) {
4763  static const char *const CXXExprs[] = {
4764  "delete", "new", "operator", "throw", "typeid"
4765  };
4766  const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4767  for (unsigned I = 0; I != NumCXXExprs; ++I)
4768  Consumer.addKeywordResult(CXXExprs[I]);
4769 
4770  if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4771  cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4772  Consumer.addKeywordResult("this");
4773 
4774  if (SemaRef.getLangOpts().CPlusPlus11) {
4775  Consumer.addKeywordResult("alignof");
4776  Consumer.addKeywordResult("nullptr");
4777  }
4778  }
4779 
4780  if (SemaRef.getLangOpts().C11) {
4781  // FIXME: We should not suggest _Alignof if the alignof macro
4782  // is present.
4783  Consumer.addKeywordResult("_Alignof");
4784  }
4785  }
4786 
4787  if (CCC.WantRemainingKeywords) {
4788  if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4789  // Statements.
4790  static const char *const CStmts[] = {
4791  "do", "else", "for", "goto", "if", "return", "switch", "while" };
4792  const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4793  for (unsigned I = 0; I != NumCStmts; ++I)
4794  Consumer.addKeywordResult(CStmts[I]);
4795 
4796  if (SemaRef.getLangOpts().CPlusPlus) {
4797  Consumer.addKeywordResult("catch");
4798  Consumer.addKeywordResult("try");
4799  }
4800 
4801  if (S && S->getBreakParent())
4802  Consumer.addKeywordResult("break");
4803 
4804  if (S && S->getContinueParent())
4805  Consumer.addKeywordResult("continue");
4806 
4807  if (SemaRef.getCurFunction() &&
4808  !SemaRef.getCurFunction()->SwitchStack.empty()) {
4809  Consumer.addKeywordResult("case");
4810  Consumer.addKeywordResult("default");
4811  }
4812  } else {
4813  if (SemaRef.getLangOpts().CPlusPlus) {
4814  Consumer.addKeywordResult("namespace");
4815  Consumer.addKeywordResult("template");
4816  }
4817 
4818  if (S && S->isClassScope()) {
4819  Consumer.addKeywordResult("explicit");
4820  Consumer.addKeywordResult("friend");
4821  Consumer.addKeywordResult("mutable");
4822  Consumer.addKeywordResult("private");
4823  Consumer.addKeywordResult("protected");
4824  Consumer.addKeywordResult("public");
4825  Consumer.addKeywordResult("virtual");
4826  }
4827  }
4828 
4829  if (SemaRef.getLangOpts().CPlusPlus) {
4830  Consumer.addKeywordResult("using");
4831 
4832  if (SemaRef.getLangOpts().CPlusPlus11)
4833  Consumer.addKeywordResult("static_assert");
4834  }
4835  }
4836 }
4837 
4838 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4839  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4841  DeclContext *MemberContext, bool EnteringContext,
4842  const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4843 
4844  if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4846  return nullptr;
4847 
4848  // In Microsoft mode, don't perform typo correction in a template member
4849  // function dependent context because it interferes with the "lookup into
4850  // dependent bases of class templates" feature.
4851  if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4852  isa<CXXMethodDecl>(CurContext))
4853  return nullptr;
4854 
4855  // We only attempt to correct typos for identifiers.
4856  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4857  if (!Typo)
4858  return nullptr;
4859 
4860  // If the scope specifier itself was invalid, don't try to correct
4861  // typos.
4862  if (SS && SS->isInvalid())
4863  return nullptr;
4864 
4865  // Never try to correct typos during any kind of code synthesis.
4866  if (!CodeSynthesisContexts.empty())
4867  return nullptr;
4868 
4869  // Don't try to correct 'super'.
4870  if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4871  return nullptr;
4872 
4873  // Abort if typo correction already failed for this specific typo.
4874  IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4875  if (locs != TypoCorrectionFailures.end() &&
4876  locs->second.count(TypoName.getLoc()))
4877  return nullptr;
4878 
4879  // Don't try to correct the identifier "vector" when in AltiVec mode.
4880  // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4881  // remove this workaround.
4882  if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4883  return nullptr;
4884 
4885  // Provide a stop gap for files that are just seriously broken. Trying
4886  // to correct all typos can turn into a HUGE performance penalty, causing
4887  // some files to take minutes to get rejected by the parser.
4888  unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4889  if (Limit && TyposCorrected >= Limit)
4890  return nullptr;
4891  ++TyposCorrected;
4892 
4893  // If we're handling a missing symbol error, using modules, and the
4894  // special search all modules option is used, look for a missing import.
4895  if (ErrorRecovery && getLangOpts().Modules &&
4896  getLangOpts().ModulesSearchAll) {
4897  // The following has the side effect of loading the missing module.
4898  getModuleLoader().lookupMissingImports(Typo->getName(),
4899  TypoName.getBeginLoc());
4900  }
4901 
4902  // Extend the lifetime of the callback. We delayed this until here
4903  // to avoid allocations in the hot path (which is where no typo correction
4904  // occurs). Note that CorrectionCandidateCallback is polymorphic and
4905  // initially stack-allocated.
4906  std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
4907  auto Consumer = std::make_unique<TypoCorrectionConsumer>(
4908  *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext,
4909  EnteringContext);
4910 
4911  // Perform name lookup to find visible, similarly-named entities.
4912  bool IsUnqualifiedLookup = false;
4913  DeclContext *QualifiedDC = MemberContext;
4914  if (MemberContext) {
4915  LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4916 
4917  // Look in qualified interfaces.
4918  if (OPT) {
4919  for (auto *I : OPT->quals())
4920  LookupVisibleDecls(I, LookupKind, *Consumer);
4921  }
4922  } else if (SS && SS->isSet()) {
4923  QualifiedDC = computeDeclContext(*SS, EnteringContext);
4924  if (!QualifiedDC)
4925  return nullptr;
4926 
4927  LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4928  } else {
4929  IsUnqualifiedLookup = true;
4930  }
4931 
4932  // Determine whether we are going to search in the various namespaces for
4933  // corrections.
4934  bool SearchNamespaces
4935  = getLangOpts().CPlusPlus &&
4936  (IsUnqualifiedLookup || (SS && SS->isSet()));
4937 
4938  if (IsUnqualifiedLookup || SearchNamespaces) {
4939  // For unqualified lookup, look through all of the names that we have
4940  // seen in this translation unit.
4941  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4942  for (const auto &I : Context.Idents)
4943  Consumer->FoundName(I.getKey());
4944 
4945  // Walk through identifiers in external identifier sources.
4946  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4947  if (IdentifierInfoLookup *External
4949  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4950  do {
4951  StringRef Name = Iter->Next();
4952  if (Name.empty())
4953  break;
4954 
4955  Consumer->FoundName(Name);
4956  } while (true);
4957  }
4958  }
4959 
4960  AddKeywordsToConsumer(*this, *Consumer, S,
4961  *Consumer->getCorrectionValidator(),
4962  SS && SS->isNotEmpty());
4963 
4964  // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4965  // to search those namespaces.
4966  if (SearchNamespaces) {
4967  // Load any externally-known namespaces.
4968  if (ExternalSource && !LoadedExternalKnownNamespaces) {
4969  SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4970  LoadedExternalKnownNamespaces = true;
4971  ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4972  for (auto *N : ExternalKnownNamespaces)
4973  KnownNamespaces[N] = true;
4974  }
4975 
4976  Consumer->addNamespaces(KnownNamespaces);
4977  }
4978 
4979  return Consumer;
4980 }
4981 
4982 /// Try to "correct" a typo in the source code by finding
4983 /// visible declarations whose names are similar to the name that was
4984 /// present in the source code.
4985 ///
4986 /// \param TypoName the \c DeclarationNameInfo structure that contains
4987 /// the name that was present in the source code along with its location.
4988 ///
4989 /// \param LookupKind the name-lookup criteria used to search for the name.
4990 ///
4991 /// \param S the scope in which name lookup occurs.
4992 ///
4993 /// \param SS the nested-name-specifier that precedes the name we're
4994 /// looking for, if present.
4995 ///
4996 /// \param CCC A CorrectionCandidateCallback object that provides further
4997 /// validation of typo correction candidates. It also provides flags for
4998 /// determining the set of keywords permitted.
4999 ///
5000 /// \param MemberContext if non-NULL, the context in which to look for
5001 /// a member access expression.
5002 ///
5003 /// \param EnteringContext whether we're entering the context described by
5004 /// the nested-name-specifier SS.
5005 ///
5006 /// \param OPT when non-NULL, the search for visible declarations will
5007 /// also walk the protocols in the qualified interfaces of \p OPT.
5008 ///
5009 /// \returns a \c TypoCorrection containing the corrected name if the typo
5010 /// along with information such as the \c NamedDecl where the corrected name
5011 /// was declared, and any additional \c NestedNameSpecifier needed to access
5012 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
5014  Sema::LookupNameKind LookupKind,
5015  Scope *S, CXXScopeSpec *SS,
5017  CorrectTypoKind Mode,
5018  DeclContext *MemberContext,
5019  bool EnteringContext,
5020  const ObjCObjectPointerType *OPT,
5021  bool RecordFailure) {
5022  // Always let the ExternalSource have the first chance at correction, even
5023  // if we would otherwise have given up.
5024  if (ExternalSource) {
5025  if (TypoCorrection Correction =
5026  ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC,
5027  MemberContext, EnteringContext, OPT))
5028  return Correction;
5029  }
5030 
5031  // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
5032  // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
5033  // some instances of CTC_Unknown, while WantRemainingKeywords is true
5034  // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
5035  bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
5036 
5037  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5038  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
5039  MemberContext, EnteringContext,
5040  OPT, Mode == CTK_ErrorRecovery);
5041 
5042  if (!Consumer)
5043  return TypoCorrection();
5044 
5045  // If we haven't found anything, we're done.
5046  if (Consumer->empty())
5047  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5048 
5049  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5050  // is not more that about a third of the length of the typo's identifier.
5051  unsigned ED = Consumer->getBestEditDistance(true);
5052  unsigned TypoLen = Typo->getName().size();
5053  if (ED > 0 && TypoLen / ED < 3)
5054  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5055 
5056  TypoCorrection BestTC = Consumer->getNextCorrection();
5057  TypoCorrection SecondBestTC = Consumer->getNextCorrection();
5058  if (!BestTC)
5059  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5060 
5061  ED = BestTC.getEditDistance();
5062 
5063  if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
5064  // If this was an unqualified lookup and we believe the callback
5065  // object wouldn't have filtered out possible corrections, note
5066  // that no correction was found.
5067  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5068  }
5069 
5070  // If only a single name remains, return that result.
5071  if (!SecondBestTC ||
5072  SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
5073  const TypoCorrection &Result = BestTC;
5074 
5075  // Don't correct to a keyword that's the same as the typo; the keyword
5076  // wasn't actually in scope.
5077  if (ED == 0 && Result.isKeyword())
5078  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5079 
5080  TypoCorrection TC = Result;
5081  TC.setCorrectionRange(SS, TypoName);
5082  checkCorrectionVisibility(*this, TC);
5083  return TC;
5084  } else if (SecondBestTC && ObjCMessageReceiver) {
5085  // Prefer 'super' when we're completing in a message-receiver
5086  // context.
5087 
5088  if (BestTC.getCorrection().getAsString() != "super") {
5089  if (SecondBestTC.getCorrection().getAsString() == "super")
5090  BestTC = SecondBestTC;
5091  else if ((*Consumer)["super"].front().isKeyword())
5092  BestTC = (*Consumer)["super"].front();
5093  }
5094  // Don't correct to a keyword that's the same as the typo; the keyword
5095  // wasn't actually in scope.
5096  if (BestTC.getEditDistance() == 0 ||
5097  BestTC.getCorrection().getAsString() != "super")
5098  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5099 
5100  BestTC.setCorrectionRange(SS, TypoName);
5101  return BestTC;
5102  }
5103 
5104  // Record the failure's location if needed and return an empty correction. If
5105  // this was an unqualified lookup and we believe the callback object did not
5106  // filter out possible corrections, also cache the failure for the typo.
5107  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
5108 }
5109 
5110 /// Try to "correct" a typo in the source code by finding
5111 /// visible declarations whose names are similar to the name that was
5112 /// present in the source code.
5113 ///
5114 /// \param TypoName the \c DeclarationNameInfo structure that contains
5115 /// the name that was present in the source code along with its location.
5116 ///
5117 /// \param LookupKind the name-lookup criteria used to search for the name.
5118 ///
5119 /// \param S the scope in which name lookup occurs.
5120 ///
5121 /// \param SS the nested-name-specifier that precedes the name we're
5122 /// looking for, if present.
5123 ///
5124 /// \param CCC A CorrectionCandidateCallback object that provides further
5125 /// validation of typo correction candidates. It also provides flags for
5126 /// determining the set of keywords permitted.
5127 ///
5128 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
5129 /// diagnostics when the actual typo correction is attempted.
5130 ///
5131 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
5132 /// Expr from a typo correction candidate.
5133 ///
5134 /// \param MemberContext if non-NULL, the context in which to look for
5135 /// a member access expression.
5136 ///
5137 /// \param EnteringContext whether we're entering the context described by
5138 /// the nested-name-specifier SS.
5139 ///
5140 /// \param OPT when non-NULL, the search for visible declarations will
5141 /// also walk the protocols in the qualified interfaces of \p OPT.
5142 ///
5143 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
5144 /// Expr representing the result of performing typo correction, or nullptr if
5145 /// typo correction is not possible. If nullptr is returned, no diagnostics will
5146 /// be emitted and it is the responsibility of the caller to emit any that are
5147 /// needed.
5149  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
5152  DeclContext *MemberContext, bool EnteringContext,
5153  const ObjCObjectPointerType *OPT) {
5154  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
5155  MemberContext, EnteringContext,
5156  OPT, Mode == CTK_ErrorRecovery);
5157 
5158  // Give the external sema source a chance to correct the typo.
5159  TypoCorrection ExternalTypo;
5160  if (ExternalSource && Consumer) {
5161  ExternalTypo = ExternalSource->CorrectTypo(
5162  TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
5163  MemberContext, EnteringContext, OPT);
5164  if (ExternalTypo)
5165  Consumer->addCorrection(ExternalTypo);
5166  }
5167 
5168  if (!Consumer || Consumer->empty())
5169  return nullptr;
5170 
5171  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5172  // is not more that about a third of the length of the typo's identifier.
5173  unsigned ED = Consumer->getBestEditDistance(true);
5174  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5175  if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
5176  return nullptr;
5177  ExprEvalContexts.back().NumTypos++;
5178  return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC),
5179  TypoName.getLoc());
5180 }
5181 
5183  if (!CDecl) return;
5184 
5185  if (isKeyword())
5186  CorrectionDecls.clear();
5187 
5188  CorrectionDecls.push_back(CDecl);
5189 
5190  if (!CorrectionName)
5191  CorrectionName = CDecl->getDeclName();
5192 }
5193 
5195  if (CorrectionNameSpec) {
5196  std::string tmpBuffer;
5197  llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5198  CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
5199  PrefixOStream << CorrectionName;
5200  return PrefixOStream.str();
5201  }
5202 
5203  return CorrectionName.getAsString();
5204 }
5205 
5207  const TypoCorrection &candidate) {
5208  if (!candidate.isResolved())
5209  return true;
5210 
5211  if (candidate.isKeyword())
5214 
5215  bool HasNonType = false;
5216  bool HasStaticMethod = false;
5217  bool HasNonStaticMethod = false;
5218  for (Decl *D : candidate) {
5219  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
5220  D = FTD->getTemplatedDecl();
5221  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
5222  if (Method->isStatic())
5223  HasStaticMethod = true;
5224  else
5225  HasNonStaticMethod = true;
5226  }
5227  if (!isa<TypeDecl>(D))
5228  HasNonType = true;
5229  }
5230 
5231  if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5232  !candidate.getCorrectionSpecifier())
5233  return false;
5234 
5235  return WantTypeSpecifiers || HasNonType;
5236 }
5237 
5239  bool HasExplicitTemplateArgs,
5240  MemberExpr *ME)
5241  : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5242  CurContext(SemaRef.CurContext), MemberFn(ME) {
5243  WantTypeSpecifiers = false;
5244  WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5245  !HasExplicitTemplateArgs && NumArgs == 1;
5246  WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5247  WantRemainingKeywords = false;
5248 }
5249 
5251  if (!candidate.getCorrectionDecl())
5252  return candidate.isKeyword();
5253 
5254  for (auto *C : candidate) {
5255  FunctionDecl *FD = nullptr;
5256  NamedDecl *ND = C->getUnderlyingDecl();
5257  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
5258  FD = FTD->getTemplatedDecl();
5259  if (!HasExplicitTemplateArgs && !FD) {
5260  if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
5261  // If the Decl is neither a function nor a template function,
5262  // determine if it is a pointer or reference to a function. If so,
5263  // check against the number of arguments expected for the pointee.
5264  QualType ValType = cast<ValueDecl>(ND)->getType();
5265  if (ValType.isNull())
5266  continue;
5267  if (ValType->isAnyPointerType() || ValType->isReferenceType())
5268  ValType = ValType->getPointeeType();
5269  if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5270  if (FPT->getNumParams() == NumArgs)
5271  return true;
5272  }
5273  }
5274 
5275  // A typo for a function-style cast can look like a function call in C++.
5276  if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr
5277  : isa<TypeDecl>(ND)) &&
5278  CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5279  // Only a class or class template can take two or more arguments.
5280  return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND);
5281 
5282  // Skip the current candidate if it is not a FunctionDecl or does not accept
5283  // the current number of arguments.
5284  if (!FD || !(FD->getNumParams() >= NumArgs &&
5285  FD->getMinRequiredArguments() <= NumArgs))
5286  continue;
5287 
5288  // If the current candidate is a non-static C++ method, skip the candidate
5289  // unless the method being corrected--or the current DeclContext, if the
5290  // function being corrected is not a method--is a method in the same class
5291  // or a descendent class of the candidate's parent class.
5292  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
5293  if (MemberFn || !MD->isStatic()) {
5294  CXXMethodDecl *CurMD =
5295  MemberFn
5296  ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
5297  : dyn_cast_or_null<CXXMethodDecl>(CurContext);
5298  CXXRecordDecl *CurRD =
5299  CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5300  CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5301  if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5302  continue;
5303  }
5304  }
5305  return true;
5306  }
5307  return false;
5308 }
5309 
5310 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5311  const PartialDiagnostic &TypoDiag,
5312  bool ErrorRecovery) {
5313  diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5314  ErrorRecovery);
5315 }
5316 
5317 /// Find which declaration we should import to provide the definition of
5318 /// the given declaration.
5320  if (VarDecl *VD = dyn_cast<VarDecl>(D))
5321  return VD->getDefinition();
5322  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5323  return FD->getDefinition();
5324  if (TagDecl *TD = dyn_cast<TagDecl>(D))
5325  return TD->getDefinition();
5326  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5327  return ID->getDefinition();
5328  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5329  return PD->getDefinition();
5330  if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5331  if (NamedDecl *TTD = TD->getTemplatedDecl())
5332  return getDefinitionToImport(TTD);
5333  return nullptr;
5334 }
5335 
5337  MissingImportKind MIK, bool Recover) {
5338  // Suggest importing a module providing the definition of this entity, if
5339  // possible.
5341  if (!Def)
5342  Def = Decl;
5343 
5344  Module *Owner = getOwningModule(Def);
5345  assert(Owner && "definition of hidden declaration is not in a module");
5346 
5347  llvm::SmallVector<Module*, 8> OwningModules;
5348  OwningModules.push_back(Owner);
5349  auto Merged = Context.getModulesWithMergedDefinition(Def);
5350  OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5351 
5352  diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
5353  Recover);
5354 }
5355 
5356 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5357 /// suggesting the addition of a #include of the specified file.
5359  llvm::StringRef IncludingFile) {
5360  bool IsSystem = false;
5362  E, IncludingFile, &IsSystem);
5363  return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5364 }
5365 
5367  SourceLocation DeclLoc,
5368  ArrayRef<Module *> Modules,
5369  MissingImportKind MIK, bool Recover) {
5370  assert(!Modules.empty());
5371 
5372  auto NotePrevious = [&] {
5373  // FIXME: Suppress the note backtrace even under
5374  // -fdiagnostics-show-note-include-stack. We don't care how this
5375  // declaration was previously reached.
5376  Diag(DeclLoc, diag::note_unreachable_entity) << (int)MIK;
5377  };
5378 
5379  // Weed out duplicates from module list.
5380  llvm::SmallVector<Module*, 8> UniqueModules;
5381  llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5382  for (auto *M : Modules) {
5383  if (M->Kind == Module::GlobalModuleFragment)
5384  continue;
5385  if (UniqueModuleSet.insert(M).second)
5386  UniqueModules.push_back(M);
5387  }
5388 
5389  // Try to find a suitable header-name to #include.
5390  std::string HeaderName;
5391  if (const FileEntry *Header =
5392  PP.getHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) {
5393  if (const FileEntry *FE =
5395  HeaderName = getHeaderNameForHeader(PP, Header, FE->tryGetRealPathName());
5396  }
5397 
5398  // If we have a #include we should suggest, or if all definition locations
5399  // were in global module fragments, don't suggest an import.
5400  if (!HeaderName.empty() || UniqueModules.empty()) {
5401  // FIXME: Find a smart place to suggest inserting a #include, and add
5402  // a FixItHint there.
5403  Diag(UseLoc, diag::err_module_unimported_use_header)
5404  << (int)MIK << Decl << !HeaderName.empty() << HeaderName;
5405  // Produce a note showing where the entity was declared.
5406  NotePrevious();
5407  if (Recover)
5408  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5409  return;
5410  }
5411 
5412  Modules = UniqueModules;
5413 
5414  if (Modules.size() > 1) {
5415  std::string ModuleList;
5416  unsigned N = 0;
5417  for (Module *M : Modules) {
5418  ModuleList += "\n ";
5419  if (++N == 5 && N != Modules.size()) {
5420  ModuleList += "[...]";
5421  break;
5422  }
5423  ModuleList += M->getFullModuleName();
5424  }
5425 
5426  Diag(UseLoc, diag::err_module_unimported_use_multiple)
5427  << (int)MIK << Decl << ModuleList;
5428  } else {
5429  // FIXME: Add a FixItHint that imports the corresponding module.
5430  Diag(UseLoc, diag::err_module_unimported_use)
5431  << (int)MIK << Decl << Modules[0]->getFullModuleName();
5432  }
5433 
5434  NotePrevious();
5435 
5436  // Try to recover by implicitly importing this module.
5437  if (Recover)
5438  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5439 }
5440 
5441 /// Diagnose a successfully-corrected typo. Separated from the correction
5442 /// itself to allow external validation of the result, etc.
5443 ///
5444 /// \param Correction The result of performing typo correction.
5445 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5446 /// string added to it (and usually also a fixit).
5447 /// \param PrevNote A note to use when indicating the location of the entity to
5448 /// which we are correcting. Will have the correction string added to it.
5449 /// \param ErrorRecovery If \c true (the default), the caller is going to
5450 /// recover from the typo as if the corrected string had been typed.
5451 /// In this case, \c PDiag must be an error, and we will attach a fixit
5452 /// to it.
5453 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5454  const PartialDiagnostic &TypoDiag,
5455  const PartialDiagnostic &PrevNote,
5456  bool ErrorRecovery) {
5457  std::string CorrectedStr = Correction.getAsString(getLangOpts());
5458  std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5460  Correction.getCorrectionRange(), CorrectedStr);
5461 
5462  // Maybe we're just missing a module import.
5463  if (Correction.requiresImport()) {
5464  NamedDecl *Decl = Correction.getFoundDecl();
5465  assert(Decl && "import required but no declaration to import");
5466 
5468  MissingImportKind::Declaration, ErrorRecovery);
5469  return;
5470  }
5471 
5472  Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5473  << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5474 
5475  NamedDecl *ChosenDecl =
5476  Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5477  if (PrevNote.getDiagID() && ChosenDecl)
5478  Diag(ChosenDecl->getLocation(), PrevNote)
5479  << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5480 
5481  // Add any extra diagnostics.
5482  for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5483  Diag(Correction.getCorrectionRange().getBegin(), PD);
5484 }
5485 
5486 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5487  TypoDiagnosticGenerator TDG,
5488  TypoRecoveryCallback TRC,
5489  SourceLocation TypoLoc) {
5490  assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5491  auto TE = new (Context) TypoExpr(Context.DependentTy, TypoLoc);
5492  auto &State = DelayedTypos[TE];
5493  State.Consumer = std::move(TCC);
5494  State.DiagHandler = std::move(TDG);
5495  State.RecoveryHandler = std::move(TRC);
5496  if (TE)
5497  TypoExprs.push_back(TE);
5498  return TE;
5499 }
5500 
5501 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5502  auto Entry = DelayedTypos.find(TE);
5503  assert(Entry != DelayedTypos.end() &&
5504  "Failed to get the state for a TypoExpr!");
5505  return Entry->second;
5506 }
5507 
5509  DelayedTypos.erase(TE);
5510 }
5511 
5513  DeclarationNameInfo Name(II, IILoc);
5515  R.suppressDiagnostics();
5516  R.setHideTags(false);
5517  LookupName(R, S);
5518  R.dump();
5519 }
clang::OpenCL
@ OpenCL
Definition: LangStandard.h:58
clang::Sema::MissingImportKind::Declaration
@ Declaration
clang::NestedNameSpecifier::Create
static NestedNameSpecifier * Create(const ASTContext &Context, NestedNameSpecifier *Prefix, IdentifierInfo *II)
Builds a specifier combining a prefix and an identifier.
Definition: NestedNameSpecifier.cpp:59
clang::TypoCorrection::getCorrectionRange
SourceRange getCorrectionRange() const
Definition: TypoCorrection.h:226
clang::ObjCInterfaceDecl
Represents an ObjC class declaration.
Definition: DeclObjC.h:1151
clang::Sema::SpecialMemberOverloadResult
SpecialMemberOverloadResult - The overloading result for a special member function.
Definition: Sema.h:1341
clang::Sema::CurContext
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:423
clang::ASTContext::getTypedefType
QualType getTypedefType(const TypedefNameDecl *Decl, QualType Underlying=QualType()) const
Return the unique reference to the type for the specified typedef-name decl.
Definition: ASTContext.cpp:4582
clang::LookupResult::setNamingClass
void setNamingClass(CXXRecordDecl *Record)
Sets the 'naming class' for this lookup.
Definition: Lookup.h:408
Builtins.h
clang::LangOptions::CurrentModule
std::string CurrentModule
The name of the current module, of which the main source file is a part.
Definition: LangOptions.h:343
clang::LabelDecl::Create
static LabelDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdentL, IdentifierInfo *II)
Definition: Decl.cpp:4835
clang::Sema::CorrectTypoKind
CorrectTypoKind
Definition: Sema.h:4208
clang::Scope::getFnParent
const Scope * getFnParent() const
getFnParent - Return the closest scope that is a function body.
Definition: Scope.h:238
clang::Sema::CorrectTypoDelayed
TypoExpr * CorrectTypoDelayed(const DeclarationNameInfo &Typo, Sema::LookupNameKind LookupKind, Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, DeclContext *MemberContext=nullptr, bool EnteringContext=false, const ObjCObjectPointerType *OPT=nullptr)
Try to "correct" a typo in the source code by finding visible declarations whose names are similar to...
Definition: SemaLookup.cpp:5148
clang::LookupResult::isForRedeclaration
bool isForRedeclaration() const
True if this lookup is just looking for an existing declaration.
Definition: Lookup.h:258
clang::LookupResult::NotFound
@ NotFound
No entity found met the criteria.
Definition: Lookup.h:50
clang::Sema::makeMergedDefinitionVisible
void makeMergedDefinitionVisible(NamedDecl *ND)
Make a merged definition of an existing hidden definition ND visible at the specified location.
Definition: SemaLookup.cpp:1505
GetOpenCLBuiltinFctOverloads
static void GetOpenCLBuiltinFctOverloads(ASTContext &Context, unsigned GenTypeMaxCnt, std::vector< QualType > &FunctionList, SmallVector< QualType, 1 > &RetTypes, SmallVector< SmallVector< QualType, 1 >, 5 > &ArgTypes)
Create a list of the candidate function overloads for an OpenCL builtin function.
Definition: SemaLookup.cpp:754
clang::Sema::LookupNamespaceName
@ LookupNamespaceName
Look up a namespace name within a C++ using directive or namespace alias definition,...
Definition: Sema.h:3995
clang::CorrectionCandidateCallback::ValidateCandidate
virtual bool ValidateCandidate(const TypoCorrection &candidate)
Simple predicate used by the default RankCandidate to determine whether to return an edit distance of...
Definition: SemaLookup.cpp:5206
clang::Decl::IDNS_Type
@ IDNS_Type
Types, declared with 'struct foo', typedefs, etc.
Definition: DeclBase.h:133
clang::NestedNameSpecifier::Identifier
@ Identifier
An identifier, stored as an IdentifierInfo*.
Definition: NestedNameSpecifier.h:81
clang::Sema::runWithSufficientStackSpace
void runWithSufficientStackSpace(SourceLocation Loc, llvm::function_ref< void()> Fn)
Run some code with "sufficient" stack space.
Definition: Sema.cpp:486
LookupPredefedObjCSuperType
static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S)
Looks up the declaration of "struct objc_super" and saves it for later use in building builtin declar...
Definition: SemaLookup.cpp:955
clang::CorrectionCandidateCallback::WantTypeSpecifiers
bool WantTypeSpecifiers
Definition: TypoCorrection.h:328
clang::CXXConstructorDecl
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2401
clang::NestedNameSpecifier::getAsRecordDecl
CXXRecordDecl * getAsRecordDecl() const
Retrieve the record declaration stored in this nested name specifier.
Definition: NestedNameSpecifier.cpp:185
clang::CXXBaseSpecifier::getType
QualType getType() const
Retrieves the type of the base class.
Definition: DeclCXX.h:246
clang::ASTContext::getTypeDeclType
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h:1538
clang::TypoCorrection::begin
decl_iterator begin()
Definition: TypoCorrection.h:232
clang::DeclContext::getParentASTContext
ASTContext & getParentASTContext() const
Definition: DeclBase.h:1889
clang::TypoCorrection::decl_iterator
SmallVectorImpl< NamedDecl * >::iterator decl_iterator
Definition: TypoCorrection.h:230
clang::index::SymbolKind::Protocol
@ Protocol
clang::FunctionDecl::getNumParams
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3380
clang::NestedNameSpecifier::Super
@ Super
Microsoft's '__super' specifier, stored as a CXXRecordDecl* of the class it appeared in.
Definition: NestedNameSpecifier.h:101
clang::VarDecl::getTemplateInstantiationPattern
VarDecl * getTemplateInstantiationPattern() const
Retrieve the variable declaration from which this variable could be instantiated, if it is an instant...
Definition: Decl.cpp:2565
clang::CorrectionCandidateCallback::RankCandidate
virtual unsigned RankCandidate(const TypoCorrection &candidate)
Method used by Sema::CorrectTypo to assign an "edit distance" rank to a candidate (where a lower valu...
Definition: TypoCorrection.h:309
clang::CXXRecordDecl::hasAnyDependentBases
bool hasAnyDependentBases() const
Determine whether this class has any dependent base classes which are not the current instantiation.
Definition: DeclCXX.cpp:565
clang::FPOptions::isFPConstrained
bool isFPConstrained() const
Definition: LangOptions.h:556
clang::TypoCorrectionConsumer::addNamespaces
void addNamespaces(const llvm::MapVector< NamespaceDecl *, bool > &KnownNamespaces)
Set-up method to add to the consumer the set of namespaces to use in performing corrections to nested...
Definition: SemaLookup.cpp:4331
clang::LookupResult::setAllowHidden
void setAllowHidden(bool AH)
Specify whether hidden declarations are visible, e.g., for recovery reasons.
Definition: Lookup.h:275
DeclLookups.h
clang::Sema::LookupLiteralOperator
LiteralOperatorLookupResult LookupLiteralOperator(Scope *S, LookupResult &R, ArrayRef< QualType > ArgTys, bool AllowRaw, bool AllowTemplate, bool AllowStringTemplate, bool DiagnoseMissing, StringLiteral *StringLit=nullptr)
LookupLiteralOperator - Determine which literal operator should be used for a user-defined literal,...
Definition: SemaLookup.cpp:3378
clang::index::SymbolKind::Class
@ Class
clang::LookupResult::setLookupName
void setLookupName(DeclarationName Name)
Sets the name to look up.
Definition: Lookup.h:248
clang::Sema::LookupLocalFriendName
@ LookupLocalFriendName
Look up a friend of a local class.
Definition: Sema.h:4007
clang::UnresolvedSetImpl
A set of unresolved declarations.
Definition: UnresolvedSet.h:61
clang::Sema::TypoDiagnosticGenerator
std::function< void(const TypoCorrection &)> TypoDiagnosticGenerator
Definition: Sema.h:4076
clang::ExternalSemaSource::ReadKnownNamespaces
virtual void ReadKnownNamespaces(SmallVectorImpl< NamespaceDecl * > &Namespaces)
Load the set of namespaces that are known to the external source, which will be used during typo corr...
Definition: Sema.cpp:2294
clang::Decl::isTemplateDecl
bool isTemplateDecl() const
returns true if this declaration is a template
Definition: DeclBase.cpp:226
clang::SourceRange
A trivial tuple used to represent a source range.
Definition: SourceLocation.h:212
string
string(SUBSTRING ${CMAKE_CURRENT_BINARY_DIR} 0 ${PATH_LIB_START} PATH_HEAD) string(SUBSTRING $
Definition: CMakeLists.txt:22
clang::LookupResult::end
iterator end() const
Definition: Lookup.h:336
clang::DeclContext
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1347
clang::LookupResult::setHideTags
void setHideTags(bool Hide)
Sets whether tag declarations should be hidden by non-tag declarations during resolution.
Definition: Lookup.h:288
clang::Sema::TyposCorrected
unsigned TyposCorrected
The number of typos corrected by CorrectTypo.
Definition: Sema.h:9216
clang::LookupResult::isSingleResult
bool isSingleResult() const
Determines if this names a single result which is not an unresolved value using decl.
Definition: Lookup.h:308
clang::TemplateArgument::getAsTemplateOrTemplatePattern
TemplateName getAsTemplateOrTemplatePattern() const
Retrieve the template argument as a template name; if the argument is a pack expansion,...
Definition: TemplateBase.h:300
clang::TypoCorrection
Simple class containing the result of Sema::CorrectTypo.
Definition: TypoCorrection.h:42
clang::Sema::DeclareImplicitMoveConstructor
CXXConstructorDecl * DeclareImplicitMoveConstructor(CXXRecordDecl *ClassDecl)
Declare the implicit move constructor for the given class.
Definition: SemaDeclCXX.cpp:15046
clang::TemplateArgument::pack_elements
ArrayRef< TemplateArgument > pack_elements() const
Iterator range referencing all of the elements of a template argument pack.
Definition: TemplateBase.h:366
clang::Sema::getASTContext
ASTContext & getASTContext() const
Definition: Sema.h:1576
clang::Sema::LookupCopyingAssignment
CXXMethodDecl * LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals)
Look up the copying assignment operator for the given class.
Definition: SemaLookup.cpp:3327
clang::OverloadCandidateSet::CSK_Normal
@ CSK_Normal
Normal lookup.
Definition: Overload.h:940
clang::Decl::isTemplateParameter
bool isTemplateParameter() const
isTemplateParameter - Determines whether this declaration is a template parameter.
Definition: DeclBase.h:2540
clang::Sema::getCurFunction
sema::FunctionScopeInfo * getCurFunction() const
Definition: Sema.h:1899
clang::Decl::getAsFunction
FunctionDecl * getAsFunction() LLVM_READONLY
Returns the function itself, or the templated function if this is a function template.
Definition: DeclBase.cpp:218
clang::Sema::SourceMgr
SourceManager & SourceMgr
Definition: Sema.h:414
clang::IdentifierResolver::begin
iterator begin(DeclarationName Name)
begin - Returns an iterator for decls with the name 'Name'.
Definition: IdentifierResolver.cpp:230
clang::TemplateArgument::Null
@ Null
Represents an empty template argument, e.g., one that has not been deduced.
Definition: TemplateBase.h:68
clang::LookupResult::FoundOverloaded
@ FoundOverloaded
Name lookup found a set of overloaded functions that met the criteria.
Definition: Lookup.h:63
clang::LookupResult::Filter::next
NamedDecl * next()
Definition: Lookup.h:643
clang::FunctionDecl::isDeleted
bool isDeleted() const
Whether this function has been deleted.
Definition: Decl.h:2338
SemaInternal.h
clang::UsingDirectiveDecl
Represents C++ using-directive.
Definition: DeclCXX.h:2882
clang::Sema::RequireCompleteDeclContext
bool RequireCompleteDeclContext(CXXScopeSpec &SS, DeclContext *DC)
Require that the context specified by SS be complete.
Definition: SemaCXXScopeSpec.cpp:199
clang::DeclarationName::CXXConstructorName
@ CXXConstructorName
Definition: DeclarationName.h:206
clang::ASTContext::VoidTy
CanQualType VoidTy
Definition: ASTContext.h:1075
clang::LookupResult::isTemplateNameLookup
bool isTemplateNameLookup() const
Definition: Lookup.h:299
clang::Sema::LOLR_StringTemplatePack
@ LOLR_StringTemplatePack
The lookup found an overload set of literal operator templates, which expect the character type and c...
Definition: Sema.h:4065
llvm::SmallVector
Definition: LLVM.h:38
clang::NestedNameSpecifier::NamespaceAlias
@ NamespaceAlias
A namespace alias, stored as a NamespaceAliasDecl*.
Definition: NestedNameSpecifier.h:87
Lookup.h
clang::IdentifierTable::get
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
Definition: IdentifierTable.h:592
isInCurrentModule
static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts)
Determine whether the module M is part of the current module from the perspective of a module-private...
Definition: SemaLookup.cpp:1561
clang::if
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T -> getSizeExpr()))
Definition: RecursiveASTVisitor.h:1002
clang::SourceLocation
Encodes a location in the source.
Definition: SourceLocation.h:88
clang::CXXRecordDecl::conversion_begin
conversion_iterator conversion_begin() const
Definition: DeclCXX.h:1076
clang::TypoCorrectionConsumer::addKeywordResult
void addKeywordResult(StringRef Keyword)
Definition: SemaLookup.cpp:4257
clang::Sema::SpecialMemberOverloadResult::NoMemberOrDeleted
@ NoMemberOrDeleted
Definition: Sema.h:1344
clang::Sema::LookupOverloadedOperatorName
void LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, UnresolvedSetImpl &Functions)
Definition: SemaLookup.cpp:3041
clang::NamedDecl
This represents a decl that may have a name.
Definition: Decl.h:249
clang::DeclContext::getPrimaryContext
DeclContext * getPrimaryContext()
getPrimaryContext - There may be many different declarations of the same entity (including forward de...
Definition: DeclBase.cpp:1229
clang::DiagnosticsEngine::getDiagnosticOptions
DiagnosticOptions & getDiagnosticOptions() const
Retrieve the diagnostic options.
Definition: Diagnostic.h:555
clang::ASTContext::BuiltinInfo
Builtin::Context & BuiltinInfo
Definition: ASTContext.h:650
clang::SourceRange::getBegin
SourceLocation getBegin() const
Definition: SourceLocation.h:221
LookupDirect
static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC)
Definition: SemaLookup.cpp:1088
clang::OR_Success
@ OR_Success
Overload resolution succeeded.
Definition: Overload.h:53
clang::NamedDecl::getUnderlyingDecl
NamedDecl * getUnderlyingDecl()
Looks through UsingDecls and ObjCCompatibleAliasDecls for the underlying named decl.
Definition: Decl.h:459
clang::LookupResult::clear
LLVM_ATTRIBUTE_REINITIALIZES void clear()
Clears out any current state.
Definition: Lookup.h:554
CXXInheritance.h
clang::LookupResult::AmbiguousReference
@ AmbiguousReference
Name lookup results in an ambiguity because multiple definitions of entity that meet the lookup crite...
Definition: Lookup.h:118
clang::ASTContext::DeclarationNames
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:652
clang::Sema::CXXDefaultConstructor
@ CXXDefaultConstructor
Definition: Sema.h:1465
clang::CXXRecordDecl::getDefinition
CXXRecordDecl * getDefinition() const
Definition: DeclCXX.h:535
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:673
clang::TypeDecl::getTypeForDecl
const Type * getTypeForDecl() const
Definition: Decl.h:3162
clang::TemplateName::getAsTemplateDecl
TemplateDecl * getAsTemplateDecl() const
Retrieve the underlying template declaration that this template name refers to, if known.
Definition: TemplateName.cpp:101
clang::Sema::LookupAnyName
@ LookupAnyName
Look up any declaration with any name.
Definition: Sema.h:4017
clang::Sema::AR_accessible
@ AR_accessible
Definition: Sema.h:7348
clang::EST_None
@ EST_None
no exception specification
Definition: ExceptionSpecificationType.h:21
clang::Sema::LOLR_ErrorNoDiagnostic
@ LOLR_ErrorNoDiagnostic
The lookup found no match but no diagnostic was issued.
Definition: Sema.h:4051
clang::NestedNameSpecifier
Represents a C++ nested name specifier, such as "\::std::vector<int>::".
Definition: NestedNameSpecifier.h:50
clang::tooling::Filter
llvm::cl::opt< std::string > Filter
Cursor
Cursor
Definition: SerializedDiagnosticReader.cpp:109
clang::Decl::IDNS_Using
@ IDNS_Using
This declaration is a using declaration.
Definition: