clang  10.0.0svn
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;
98  llvm::SmallPtrSet<DeclContext*, 8> visited;
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) {
218  IDNS = Decl::IDNS_Ordinary;
219  if (CPlusPlus) {
221  if (Redeclaration)
223  }
224  if (Redeclaration)
225  IDNS |= Decl::IDNS_LocalExtern;
226  break;
227 
229  // Operator lookup is its own crazy thing; it is not the same
230  // as (e.g.) looking up an operator name for redeclaration.
231  assert(!Redeclaration && "cannot do redeclaration operator lookup");
233  break;
234 
235  case Sema::LookupTagName:
236  if (CPlusPlus) {
237  IDNS = Decl::IDNS_Type;
238 
239  // When looking for a redeclaration of a tag name, we add:
240  // 1) TagFriend to find undeclared friend decls
241  // 2) Namespace because they can't "overload" with tag decls.
242  // 3) Tag because it includes class templates, which can't
243  // "overload" with tag decls.
244  if (Redeclaration)
246  } else {
247  IDNS = Decl::IDNS_Tag;
248  }
249  break;
250 
251  case Sema::LookupLabel:
252  IDNS = Decl::IDNS_Label;
253  break;
254 
256  IDNS = Decl::IDNS_Member;
257  if (CPlusPlus)
259  break;
260 
263  break;
264 
266  IDNS = Decl::IDNS_Namespace;
267  break;
268 
270  assert(Redeclaration && "should only be used for redecl lookup");
274  break;
275 
278  break;
279 
282  break;
283 
285  IDNS = Decl::IDNS_OMPMapper;
286  break;
287 
288  case Sema::LookupAnyName:
291  | Decl::IDNS_Type;
292  break;
293  }
294  return IDNS;
295 }
296 
297 void LookupResult::configure() {
298  IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
299  isForRedeclaration());
300 
301  // If we're looking for one of the allocation or deallocation
302  // operators, make sure that the implicitly-declared new and delete
303  // operators can be found.
304  switch (NameInfo.getName().getCXXOverloadedOperator()) {
305  case OO_New:
306  case OO_Delete:
307  case OO_Array_New:
308  case OO_Array_Delete:
309  getSema().DeclareGlobalNewDelete();
310  break;
311 
312  default:
313  break;
314  }
315 
316  // Compiler builtins are always visible, regardless of where they end
317  // up being declared.
318  if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
319  if (unsigned BuiltinID = Id->getBuiltinID()) {
320  if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
321  AllowHidden = true;
322  }
323  }
324 }
325 
326 bool LookupResult::sanity() const {
327  // This function is never called by NDEBUG builds.
328  assert(ResultKind != NotFound || Decls.size() == 0);
329  assert(ResultKind != Found || Decls.size() == 1);
330  assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
331  (Decls.size() == 1 &&
332  isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
333  assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
334  assert(ResultKind != Ambiguous || Decls.size() > 1 ||
335  (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
336  Ambiguity == AmbiguousBaseSubobjectTypes)));
337  assert((Paths != nullptr) == (ResultKind == Ambiguous &&
338  (Ambiguity == AmbiguousBaseSubobjectTypes ||
339  Ambiguity == AmbiguousBaseSubobjects)));
340  return true;
341 }
342 
343 // Necessary because CXXBasePaths is not complete in Sema.h
344 void LookupResult::deletePaths(CXXBasePaths *Paths) {
345  delete Paths;
346 }
347 
348 /// Get a representative context for a declaration such that two declarations
349 /// will have the same context if they were found within the same scope.
351  // For function-local declarations, use that function as the context. This
352  // doesn't account for scopes within the function; the caller must deal with
353  // those.
355  if (DC->isFunctionOrMethod())
356  return DC;
357 
358  // Otherwise, look at the semantic context of the declaration. The
359  // declaration must have been found there.
360  return D->getDeclContext()->getRedeclContext();
361 }
362 
363 /// Determine whether \p D is a better lookup result than \p Existing,
364 /// given that they declare the same entity.
366  NamedDecl *D, NamedDecl *Existing) {
367  // When looking up redeclarations of a using declaration, prefer a using
368  // shadow declaration over any other declaration of the same entity.
369  if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
370  !isa<UsingShadowDecl>(Existing))
371  return true;
372 
373  auto *DUnderlying = D->getUnderlyingDecl();
374  auto *EUnderlying = Existing->getUnderlyingDecl();
375 
376  // If they have different underlying declarations, prefer a typedef over the
377  // original type (this happens when two type declarations denote the same
378  // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
379  // might carry additional semantic information, such as an alignment override.
380  // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
381  // declaration over a typedef.
382  if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
383  assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
384  bool HaveTag = isa<TagDecl>(EUnderlying);
385  bool WantTag = Kind == Sema::LookupTagName;
386  return HaveTag != WantTag;
387  }
388 
389  // Pick the function with more default arguments.
390  // FIXME: In the presence of ambiguous default arguments, we should keep both,
391  // so we can diagnose the ambiguity if the default argument is needed.
392  // See C++ [over.match.best]p3.
393  if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
394  auto *EFD = cast<FunctionDecl>(EUnderlying);
395  unsigned DMin = DFD->getMinRequiredArguments();
396  unsigned EMin = EFD->getMinRequiredArguments();
397  // If D has more default arguments, it is preferred.
398  if (DMin != EMin)
399  return DMin < EMin;
400  // FIXME: When we track visibility for default function arguments, check
401  // that we pick the declaration with more visible default arguments.
402  }
403 
404  // Pick the template with more default template arguments.
405  if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
406  auto *ETD = cast<TemplateDecl>(EUnderlying);
407  unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
408  unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
409  // If D has more default arguments, it is preferred. Note that default
410  // arguments (and their visibility) is monotonically increasing across the
411  // redeclaration chain, so this is a quick proxy for "is more recent".
412  if (DMin != EMin)
413  return DMin < EMin;
414  // If D has more *visible* default arguments, it is preferred. Note, an
415  // earlier default argument being visible does not imply that a later
416  // default argument is visible, so we can't just check the first one.
417  for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
418  I != N; ++I) {
420  ETD->getTemplateParameters()->getParam(I)) &&
422  DTD->getTemplateParameters()->getParam(I)))
423  return true;
424  }
425  }
426 
427  // VarDecl can have incomplete array types, prefer the one with more complete
428  // array type.
429  if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
430  VarDecl *EVD = cast<VarDecl>(EUnderlying);
431  if (EVD->getType()->isIncompleteType() &&
432  !DVD->getType()->isIncompleteType()) {
433  // Prefer the decl with a more complete type if visible.
434  return S.isVisible(DVD);
435  }
436  return false; // Avoid picking up a newer decl, just because it was newer.
437  }
438 
439  // For most kinds of declaration, it doesn't really matter which one we pick.
440  if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
441  // If the existing declaration is hidden, prefer the new one. Otherwise,
442  // keep what we've got.
443  return !S.isVisible(Existing);
444  }
445 
446  // Pick the newer declaration; it might have a more precise type.
447  for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
448  Prev = Prev->getPreviousDecl())
449  if (Prev == EUnderlying)
450  return true;
451  return false;
452 }
453 
454 /// Determine whether \p D can hide a tag declaration.
455 static bool canHideTag(NamedDecl *D) {
456  // C++ [basic.scope.declarative]p4:
457  // Given a set of declarations in a single declarative region [...]
458  // exactly one declaration shall declare a class name or enumeration name
459  // that is not a typedef name and the other declarations shall all refer to
460  // the same variable, non-static data member, or enumerator, or all refer
461  // to functions and function templates; in this case the class name or
462  // enumeration name is hidden.
463  // C++ [basic.scope.hiding]p2:
464  // A class name or enumeration name can be hidden by the name of a
465  // variable, data member, function, or enumerator declared in the same
466  // scope.
467  // An UnresolvedUsingValueDecl always instantiates to one of these.
468  D = D->getUnderlyingDecl();
469  return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
470  isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
471  isa<UnresolvedUsingValueDecl>(D);
472 }
473 
474 /// Resolves the result kind of this lookup.
476  unsigned N = Decls.size();
477 
478  // Fast case: no possible ambiguity.
479  if (N == 0) {
480  assert(ResultKind == NotFound ||
481  ResultKind == NotFoundInCurrentInstantiation);
482  return;
483  }
484 
485  // If there's a single decl, we need to examine it to decide what
486  // kind of lookup this is.
487  if (N == 1) {
488  NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
489  if (isa<FunctionTemplateDecl>(D))
490  ResultKind = FoundOverloaded;
491  else if (isa<UnresolvedUsingValueDecl>(D))
492  ResultKind = FoundUnresolvedValue;
493  return;
494  }
495 
496  // Don't do any extra resolution if we've already resolved as ambiguous.
497  if (ResultKind == Ambiguous) return;
498 
499  llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
500  llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
501 
502  bool Ambiguous = false;
503  bool HasTag = false, HasFunction = false;
504  bool HasFunctionTemplate = false, HasUnresolved = false;
505  NamedDecl *HasNonFunction = nullptr;
506 
507  llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
508 
509  unsigned UniqueTagIndex = 0;
510 
511  unsigned I = 0;
512  while (I < N) {
513  NamedDecl *D = Decls[I]->getUnderlyingDecl();
514  D = cast<NamedDecl>(D->getCanonicalDecl());
515 
516  // Ignore an invalid declaration unless it's the only one left.
517  if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
518  Decls[I] = Decls[--N];
519  continue;
520  }
521 
522  llvm::Optional<unsigned> ExistingI;
523 
524  // Redeclarations of types via typedef can occur both within a scope
525  // and, through using declarations and directives, across scopes. There is
526  // no ambiguity if they all refer to the same type, so unique based on the
527  // canonical type.
528  if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
529  QualType T = getSema().Context.getTypeDeclType(TD);
530  auto UniqueResult = UniqueTypes.insert(
531  std::make_pair(getSema().Context.getCanonicalType(T), I));
532  if (!UniqueResult.second) {
533  // The type is not unique.
534  ExistingI = UniqueResult.first->second;
535  }
536  }
537 
538  // For non-type declarations, check for a prior lookup result naming this
539  // canonical declaration.
540  if (!ExistingI) {
541  auto UniqueResult = Unique.insert(std::make_pair(D, I));
542  if (!UniqueResult.second) {
543  // We've seen this entity before.
544  ExistingI = UniqueResult.first->second;
545  }
546  }
547 
548  if (ExistingI) {
549  // This is not a unique lookup result. Pick one of the results and
550  // discard the other.
551  if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
552  Decls[*ExistingI]))
553  Decls[*ExistingI] = Decls[I];
554  Decls[I] = Decls[--N];
555  continue;
556  }
557 
558  // Otherwise, do some decl type analysis and then continue.
559 
560  if (isa<UnresolvedUsingValueDecl>(D)) {
561  HasUnresolved = true;
562  } else if (isa<TagDecl>(D)) {
563  if (HasTag)
564  Ambiguous = true;
565  UniqueTagIndex = I;
566  HasTag = true;
567  } else if (isa<FunctionTemplateDecl>(D)) {
568  HasFunction = true;
569  HasFunctionTemplate = true;
570  } else if (isa<FunctionDecl>(D)) {
571  HasFunction = true;
572  } else {
573  if (HasNonFunction) {
574  // If we're about to create an ambiguity between two declarations that
575  // are equivalent, but one is an internal linkage declaration from one
576  // module and the other is an internal linkage declaration from another
577  // module, just skip it.
578  if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
579  D)) {
580  EquivalentNonFunctions.push_back(D);
581  Decls[I] = Decls[--N];
582  continue;
583  }
584 
585  Ambiguous = true;
586  }
587  HasNonFunction = D;
588  }
589  I++;
590  }
591 
592  // C++ [basic.scope.hiding]p2:
593  // A class name or enumeration name can be hidden by the name of
594  // an object, function, or enumerator declared in the same
595  // scope. If a class or enumeration name and an object, function,
596  // or enumerator are declared in the same scope (in any order)
597  // with the same name, the class or enumeration name is hidden
598  // wherever the object, function, or enumerator name is visible.
599  // But it's still an error if there are distinct tag types found,
600  // even if they're not visible. (ref?)
601  if (N > 1 && HideTags && HasTag && !Ambiguous &&
602  (HasFunction || HasNonFunction || HasUnresolved)) {
603  NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
604  if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
605  getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
606  getContextForScopeMatching(OtherDecl)) &&
607  canHideTag(OtherDecl))
608  Decls[UniqueTagIndex] = Decls[--N];
609  else
610  Ambiguous = true;
611  }
612 
613  // FIXME: This diagnostic should really be delayed until we're done with
614  // the lookup result, in case the ambiguity is resolved by the caller.
615  if (!EquivalentNonFunctions.empty() && !Ambiguous)
616  getSema().diagnoseEquivalentInternalLinkageDeclarations(
617  getNameLoc(), HasNonFunction, EquivalentNonFunctions);
618 
619  Decls.set_size(N);
620 
621  if (HasNonFunction && (HasFunction || HasUnresolved))
622  Ambiguous = true;
623 
624  if (Ambiguous)
625  setAmbiguous(LookupResult::AmbiguousReference);
626  else if (HasUnresolved)
628  else if (N > 1 || HasFunctionTemplate)
629  ResultKind = LookupResult::FoundOverloaded;
630  else
631  ResultKind = LookupResult::Found;
632 }
633 
634 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
636  for (I = P.begin(), E = P.end(); I != E; ++I)
637  for (DeclContext::lookup_iterator DI = I->Decls.begin(),
638  DE = I->Decls.end(); DI != DE; ++DI)
639  addDecl(*DI);
640 }
641 
643  Paths = new CXXBasePaths;
644  Paths->swap(P);
645  addDeclsFromBasePaths(*Paths);
646  resolveKind();
647  setAmbiguous(AmbiguousBaseSubobjects);
648 }
649 
651  Paths = new CXXBasePaths;
652  Paths->swap(P);
653  addDeclsFromBasePaths(*Paths);
654  resolveKind();
655  setAmbiguous(AmbiguousBaseSubobjectTypes);
656 }
657 
658 void LookupResult::print(raw_ostream &Out) {
659  Out << Decls.size() << " result(s)";
660  if (isAmbiguous()) Out << ", ambiguous";
661  if (Paths) Out << ", base paths present";
662 
663  for (iterator I = begin(), E = end(); I != E; ++I) {
664  Out << "\n";
665  (*I)->print(Out, 2);
666  }
667 }
668 
669 LLVM_DUMP_METHOD void LookupResult::dump() {
670  llvm::errs() << "lookup results for " << getLookupName().getAsString()
671  << ":\n";
672  for (NamedDecl *D : *this)
673  D->dump();
674 }
675 
676 /// Get the QualType instances of the return type and arguments for an OpenCL
677 /// builtin function signature.
678 /// \param Context (in) The Context instance.
679 /// \param OpenCLBuiltin (in) The signature currently handled.
680 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
681 /// type used as return type or as argument.
682 /// Only meaningful for generic types, otherwise equals 1.
683 /// \param RetTypes (out) List of the possible return types.
684 /// \param ArgTypes (out) List of the possible argument types. For each
685 /// argument, ArgTypes contains QualTypes for the Cartesian product
686 /// of (vector sizes) x (types) .
688  ASTContext &Context, const OpenCLBuiltinStruct &OpenCLBuiltin,
689  unsigned &GenTypeMaxCnt, SmallVector<QualType, 1> &RetTypes,
690  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
691  // Get the QualType instances of the return types.
692  unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
693  OCL2Qual(Context, TypeTable[Sig], RetTypes);
694  GenTypeMaxCnt = RetTypes.size();
695 
696  // Get the QualType instances of the arguments.
697  // First type is the return type, skip it.
698  for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
700  OCL2Qual(Context,
701  TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], Ty);
702  GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
703  ArgTypes.push_back(std::move(Ty));
704  }
705 }
706 
707 /// Create a list of the candidate function overloads for an OpenCL builtin
708 /// function.
709 /// \param Context (in) The ASTContext instance.
710 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
711 /// type used as return type or as argument.
712 /// Only meaningful for generic types, otherwise equals 1.
713 /// \param FunctionList (out) List of FunctionTypes.
714 /// \param RetTypes (in) List of the possible return types.
715 /// \param ArgTypes (in) List of the possible types for the arguments.
717  ASTContext &Context, unsigned GenTypeMaxCnt,
718  std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes,
719  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
721  PI.Variadic = false;
722 
723  // Create FunctionTypes for each (gen)type.
724  for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
725  SmallVector<QualType, 5> ArgList;
726 
727  for (unsigned A = 0; A < ArgTypes.size(); A++) {
728  // Builtins such as "max" have an "sgentype" argument that represents
729  // the corresponding scalar type of a gentype. The number of gentypes
730  // must be a multiple of the number of sgentypes.
731  assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
732  "argument type count not compatible with gentype type count");
733  unsigned Idx = IGenType % ArgTypes[A].size();
734  ArgList.push_back(ArgTypes[A][Idx]);
735  }
736 
737  FunctionList.push_back(Context.getFunctionType(
738  RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI));
739  }
740 }
741 
742 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a
743 /// non-null <Index, Len> pair, then the name is referencing an OpenCL
744 /// builtin function. Add all candidate signatures to the LookUpResult.
745 ///
746 /// \param S (in) The Sema instance.
747 /// \param LR (inout) The LookupResult instance.
748 /// \param II (in) The identifier being resolved.
749 /// \param FctIndex (in) Starting index in the BuiltinTable.
750 /// \param Len (in) The signature list has Len elements.
752  IdentifierInfo *II,
753  const unsigned FctIndex,
754  const unsigned Len) {
755  // The builtin function declaration uses generic types (gentype).
756  bool HasGenType = false;
757 
758  // Maximum number of types contained in a generic type used as return type or
759  // as argument. Only meaningful for generic types, otherwise equals 1.
760  unsigned GenTypeMaxCnt;
761 
762  for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
763  const OpenCLBuiltinStruct &OpenCLBuiltin =
764  BuiltinTable[FctIndex + SignatureIndex];
765  ASTContext &Context = S.Context;
766 
767  // Ignore this BIF if its version does not match the language options.
768  if (Context.getLangOpts().OpenCLVersion < OpenCLBuiltin.MinVersion)
769  continue;
770  if ((OpenCLBuiltin.MaxVersion != 0) &&
771  (Context.getLangOpts().OpenCLVersion >= OpenCLBuiltin.MaxVersion))
772  continue;
773 
774  SmallVector<QualType, 1> RetTypes;
776 
777  // Obtain QualType lists for the function signature.
778  GetQualTypesForOpenCLBuiltin(Context, OpenCLBuiltin, GenTypeMaxCnt,
779  RetTypes, ArgTypes);
780  if (GenTypeMaxCnt > 1) {
781  HasGenType = true;
782  }
783 
784  // Create function overload for each type combination.
785  std::vector<QualType> FunctionList;
786  GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
787  ArgTypes);
788 
789  SourceLocation Loc = LR.getNameLoc();
791  FunctionDecl *NewOpenCLBuiltin;
792 
793  for (unsigned Index = 0; Index < GenTypeMaxCnt; Index++) {
794  NewOpenCLBuiltin = FunctionDecl::Create(
795  Context, Parent, Loc, Loc, II, FunctionList[Index],
796  /*TInfo=*/nullptr, SC_Extern, false,
797  FunctionList[Index]->isFunctionProtoType());
798  NewOpenCLBuiltin->setImplicit();
799 
800  // Create Decl objects for each parameter, adding them to the
801  // FunctionDecl.
802  if (const FunctionProtoType *FP =
803  dyn_cast<FunctionProtoType>(FunctionList[Index])) {
805  for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
807  Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(),
808  nullptr, FP->getParamType(IParm),
809  /*TInfo=*/nullptr, SC_None, nullptr);
810  Parm->setScopeInfo(0, IParm);
811  ParmList.push_back(Parm);
812  }
813  NewOpenCLBuiltin->setParams(ParmList);
814  }
815  if (!S.getLangOpts().OpenCLCPlusPlus) {
816  NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context));
817  }
818  LR.addDecl(NewOpenCLBuiltin);
819  }
820  }
821 
822  // If we added overloads, need to resolve the lookup result.
823  if (Len > 1 || HasGenType)
824  LR.resolveKind();
825 }
826 
827 /// Lookup a builtin function, when name lookup would otherwise
828 /// fail.
830  Sema::LookupNameKind NameKind = R.getLookupKind();
831 
832  // If we didn't find a use of this identifier, and if the identifier
833  // corresponds to a compiler builtin, create the decl object for the builtin
834  // now, injecting it into translation unit scope, and return it.
835  if (NameKind == Sema::LookupOrdinaryName ||
838  if (II) {
839  if (getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
840  if (II == getASTContext().getMakeIntegerSeqName()) {
841  R.addDecl(getASTContext().getMakeIntegerSeqDecl());
842  return true;
843  } else if (II == getASTContext().getTypePackElementName()) {
844  R.addDecl(getASTContext().getTypePackElementDecl());
845  return true;
846  }
847  }
848 
849  // Check if this is an OpenCL Builtin, and if so, insert its overloads.
850  if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) {
851  auto Index = isOpenCLBuiltin(II->getName());
852  if (Index.first) {
853  InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1,
854  Index.second);
855  return true;
856  }
857  }
858 
859  // If this is a builtin on this (or all) targets, create the decl.
860  if (unsigned BuiltinID = II->getBuiltinID()) {
861  // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
862  // library functions like 'malloc'. Instead, we'll just error.
863  if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) &&
864  Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
865  return false;
866 
867  if (NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II,
868  BuiltinID, TUScope,
869  R.isForRedeclaration(),
870  R.getNameLoc())) {
871  R.addDecl(D);
872  return true;
873  }
874  }
875  }
876  }
877 
878  return false;
879 }
880 
881 /// Determine whether we can declare a special member function within
882 /// the class at this point.
884  // We need to have a definition for the class.
885  if (!Class->getDefinition() || Class->isDependentContext())
886  return false;
887 
888  // We can't be in the middle of defining the class.
889  return !Class->isBeingDefined();
890 }
891 
894  return;
895 
896  // If the default constructor has not yet been declared, do so now.
897  if (Class->needsImplicitDefaultConstructor())
898  DeclareImplicitDefaultConstructor(Class);
899 
900  // If the copy constructor has not yet been declared, do so now.
901  if (Class->needsImplicitCopyConstructor())
902  DeclareImplicitCopyConstructor(Class);
903 
904  // If the copy assignment operator has not yet been declared, do so now.
905  if (Class->needsImplicitCopyAssignment())
906  DeclareImplicitCopyAssignment(Class);
907 
908  if (getLangOpts().CPlusPlus11) {
909  // If the move constructor has not yet been declared, do so now.
910  if (Class->needsImplicitMoveConstructor())
911  DeclareImplicitMoveConstructor(Class);
912 
913  // If the move assignment operator has not yet been declared, do so now.
914  if (Class->needsImplicitMoveAssignment())
915  DeclareImplicitMoveAssignment(Class);
916  }
917 
918  // If the destructor has not yet been declared, do so now.
919  if (Class->needsImplicitDestructor())
920  DeclareImplicitDestructor(Class);
921 }
922 
923 /// Determine whether this is the name of an implicitly-declared
924 /// special member function.
926  switch (Name.getNameKind()) {
929  return true;
930 
932  return Name.getCXXOverloadedOperator() == OO_Equal;
933 
934  default:
935  break;
936  }
937 
938  return false;
939 }
940 
941 /// If there are any implicit member functions with the given name
942 /// that need to be declared in the given declaration context, do so.
944  DeclarationName Name,
945  SourceLocation Loc,
946  const DeclContext *DC) {
947  if (!DC)
948  return;
949 
950  switch (Name.getNameKind()) {
952  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
953  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
954  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
955  if (Record->needsImplicitDefaultConstructor())
957  if (Record->needsImplicitCopyConstructor())
959  if (S.getLangOpts().CPlusPlus11 &&
960  Record->needsImplicitMoveConstructor())
962  }
963  break;
964 
966  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
967  if (Record->getDefinition() && Record->needsImplicitDestructor() &&
969  S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
970  break;
971 
973  if (Name.getCXXOverloadedOperator() != OO_Equal)
974  break;
975 
976  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
977  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
978  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
979  if (Record->needsImplicitCopyAssignment())
981  if (S.getLangOpts().CPlusPlus11 &&
982  Record->needsImplicitMoveAssignment())
984  }
985  }
986  break;
987 
990  break;
991 
992  default:
993  break;
994  }
995 }
996 
997 // Adds all qualifying matches for a name within a decl context to the
998 // given lookup result. Returns true if any matches were found.
999 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
1000  bool Found = false;
1001 
1002  // Lazily declare C++ special member functions.
1003  if (S.getLangOpts().CPlusPlus)
1005  DC);
1006 
1007  // Perform lookup into this declaration context.
1009  for (NamedDecl *D : DR) {
1010  if ((D = R.getAcceptableDecl(D))) {
1011  R.addDecl(D);
1012  Found = true;
1013  }
1014  }
1015 
1016  if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R))
1017  return true;
1018 
1019  if (R.getLookupName().getNameKind()
1022  !isa<CXXRecordDecl>(DC))
1023  return Found;
1024 
1025  // C++ [temp.mem]p6:
1026  // A specialization of a conversion function template is not found by
1027  // name lookup. Instead, any conversion function templates visible in the
1028  // context of the use are considered. [...]
1029  const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1030  if (!Record->isCompleteDefinition())
1031  return Found;
1032 
1033  // For conversion operators, 'operator auto' should only match
1034  // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
1035  // as a candidate for template substitution.
1036  auto *ContainedDeducedType =
1038  if (R.getLookupName().getNameKind() ==
1040  ContainedDeducedType && ContainedDeducedType->isUndeducedType())
1041  return Found;
1042 
1044  UEnd = Record->conversion_end(); U != UEnd; ++U) {
1045  FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
1046  if (!ConvTemplate)
1047  continue;
1048 
1049  // When we're performing lookup for the purposes of redeclaration, just
1050  // add the conversion function template. When we deduce template
1051  // arguments for specializations, we'll end up unifying the return
1052  // type of the new declaration with the type of the function template.
1053  if (R.isForRedeclaration()) {
1054  R.addDecl(ConvTemplate);
1055  Found = true;
1056  continue;
1057  }
1058 
1059  // C++ [temp.mem]p6:
1060  // [...] For each such operator, if argument deduction succeeds
1061  // (14.9.2.3), the resulting specialization is used as if found by
1062  // name lookup.
1063  //
1064  // When referencing a conversion function for any purpose other than
1065  // a redeclaration (such that we'll be building an expression with the
1066  // result), perform template argument deduction and place the
1067  // specialization into the result set. We do this to avoid forcing all
1068  // callers to perform special deduction for conversion functions.
1070  FunctionDecl *Specialization = nullptr;
1071 
1072  const FunctionProtoType *ConvProto
1073  = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
1074  assert(ConvProto && "Nonsensical conversion function template type");
1075 
1076  // Compute the type of the function that we would expect the conversion
1077  // function to have, if it were to match the name given.
1078  // FIXME: Calling convention!
1080  EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
1081  EPI.ExceptionSpec = EST_None;
1084  None, EPI);
1085 
1086  // Perform template argument deduction against the type that we would
1087  // expect the function to have.
1088  if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
1089  Specialization, Info)
1090  == Sema::TDK_Success) {
1091  R.addDecl(Specialization);
1092  Found = true;
1093  }
1094  }
1095 
1096  return Found;
1097 }
1098 
1099 // Performs C++ unqualified lookup into the given file context.
1100 static bool
1102  DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
1103 
1104  assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
1105 
1106  // Perform direct name lookup into the LookupCtx.
1107  bool Found = LookupDirect(S, R, NS);
1108 
1109  // Perform direct name lookup into the namespaces nominated by the
1110  // using directives whose common ancestor is this namespace.
1111  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
1112  if (LookupDirect(S, R, UUE.getNominatedNamespace()))
1113  Found = true;
1114 
1115  R.resolveKind();
1116 
1117  return Found;
1118 }
1119 
1121  if (DeclContext *Ctx = S->getEntity())
1122  return Ctx->isFileContext();
1123  return false;
1124 }
1125 
1126 // Find the next outer declaration context from this scope. This
1127 // routine actually returns the semantic outer context, which may
1128 // differ from the lexical context (encoded directly in the Scope
1129 // stack) when we are parsing a member of a class template. In this
1130 // case, the second element of the pair will be true, to indicate that
1131 // name lookup should continue searching in this semantic context when
1132 // it leaves the current template parameter scope.
1133 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
1134  DeclContext *DC = S->getEntity();
1135  DeclContext *Lexical = nullptr;
1136  for (Scope *OuterS = S->getParent(); OuterS;
1137  OuterS = OuterS->getParent()) {
1138  if (OuterS->getEntity()) {
1139  Lexical = OuterS->getEntity();
1140  break;
1141  }
1142  }
1143 
1144  // C++ [temp.local]p8:
1145  // In the definition of a member of a class template that appears
1146  // outside of the namespace containing the class template
1147  // definition, the name of a template-parameter hides the name of
1148  // a member of this namespace.
1149  //
1150  // Example:
1151  //
1152  // namespace N {
1153  // class C { };
1154  //
1155  // template<class T> class B {
1156  // void f(T);
1157  // };
1158  // }
1159  //
1160  // template<class C> void N::B<C>::f(C) {
1161  // C b; // C is the template parameter, not N::C
1162  // }
1163  //
1164  // In this example, the lexical context we return is the
1165  // TranslationUnit, while the semantic context is the namespace N.
1166  if (!Lexical || !DC || !S->getParent() ||
1168  return std::make_pair(Lexical, false);
1169 
1170  // Find the outermost template parameter scope.
1171  // For the example, this is the scope for the template parameters of
1172  // template<class C>.
1173  Scope *OutermostTemplateScope = S->getParent();
1174  while (OutermostTemplateScope->getParent() &&
1175  OutermostTemplateScope->getParent()->isTemplateParamScope())
1176  OutermostTemplateScope = OutermostTemplateScope->getParent();
1177 
1178  // Find the namespace context in which the original scope occurs. In
1179  // the example, this is namespace N.
1180  DeclContext *Semantic = DC;
1181  while (!Semantic->isFileContext())
1182  Semantic = Semantic->getParent();
1183 
1184  // Find the declaration context just outside of the template
1185  // parameter scope. This is the context in which the template is
1186  // being lexically declaration (a namespace context). In the
1187  // example, this is the global scope.
1188  if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1189  Lexical->Encloses(Semantic))
1190  return std::make_pair(Semantic, true);
1191 
1192  return std::make_pair(Lexical, false);
1193 }
1194 
1195 namespace {
1196 /// An RAII object to specify that we want to find block scope extern
1197 /// declarations.
1198 struct FindLocalExternScope {
1199  FindLocalExternScope(LookupResult &R)
1200  : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1204  }
1205  void restore() {
1206  R.setFindLocalExtern(OldFindLocalExtern);
1207  }
1208  ~FindLocalExternScope() {
1209  restore();
1210  }
1211  LookupResult &R;
1212  bool OldFindLocalExtern;
1213 };
1214 } // end anonymous namespace
1215 
1216 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1217  assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1218 
1219  DeclarationName Name = R.getLookupName();
1220  Sema::LookupNameKind NameKind = R.getLookupKind();
1221 
1222  // If this is the name of an implicitly-declared special member function,
1223  // go through the scope stack to implicitly declare
1225  for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1226  if (DeclContext *DC = PreS->getEntity())
1227  DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1228  }
1229 
1230  // Implicitly declare member functions with the name we're looking for, if in
1231  // fact we are in a scope where it matters.
1232 
1233  Scope *Initial = S;
1235  I = IdResolver.begin(Name),
1236  IEnd = IdResolver.end();
1237 
1238  // First we lookup local scope.
1239  // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1240  // ...During unqualified name lookup (3.4.1), the names appear as if
1241  // they were declared in the nearest enclosing namespace which contains
1242  // both the using-directive and the nominated namespace.
1243  // [Note: in this context, "contains" means "contains directly or
1244  // indirectly".
1245  //
1246  // For example:
1247  // namespace A { int i; }
1248  // void foo() {
1249  // int i;
1250  // {
1251  // using namespace A;
1252  // ++i; // finds local 'i', A::i appears at global scope
1253  // }
1254  // }
1255  //
1256  UnqualUsingDirectiveSet UDirs(*this);
1257  bool VisitedUsingDirectives = false;
1258  bool LeftStartingScope = false;
1259  DeclContext *OutsideOfTemplateParamDC = nullptr;
1260 
1261  // When performing a scope lookup, we want to find local extern decls.
1262  FindLocalExternScope FindLocals(R);
1263 
1264  for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1265  DeclContext *Ctx = S->getEntity();
1266  bool SearchNamespaceScope = true;
1267  // Check whether the IdResolver has anything in this scope.
1268  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1269  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1270  if (NameKind == LookupRedeclarationWithLinkage &&
1271  !(*I)->isTemplateParameter()) {
1272  // If it's a template parameter, we still find it, so we can diagnose
1273  // the invalid redeclaration.
1274 
1275  // Determine whether this (or a previous) declaration is
1276  // out-of-scope.
1277  if (!LeftStartingScope && !Initial->isDeclScope(*I))
1278  LeftStartingScope = true;
1279 
1280  // If we found something outside of our starting scope that
1281  // does not have linkage, skip it.
1282  if (LeftStartingScope && !((*I)->hasLinkage())) {
1283  R.setShadowed();
1284  continue;
1285  }
1286  } else {
1287  // We found something in this scope, we should not look at the
1288  // namespace scope
1289  SearchNamespaceScope = false;
1290  }
1291  R.addDecl(ND);
1292  }
1293  }
1294  if (!SearchNamespaceScope) {
1295  R.resolveKind();
1296  if (S->isClassScope())
1297  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1298  R.setNamingClass(Record);
1299  return true;
1300  }
1301 
1302  if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1303  // C++11 [class.friend]p11:
1304  // If a friend declaration appears in a local class and the name
1305  // specified is an unqualified name, a prior declaration is
1306  // looked up without considering scopes that are outside the
1307  // innermost enclosing non-class scope.
1308  return false;
1309  }
1310 
1311  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1312  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1313  // We've just searched the last template parameter scope and
1314  // found nothing, so look into the contexts between the
1315  // lexical and semantic declaration contexts returned by
1316  // findOuterContext(). This implements the name lookup behavior
1317  // of C++ [temp.local]p8.
1318  Ctx = OutsideOfTemplateParamDC;
1319  OutsideOfTemplateParamDC = nullptr;
1320  }
1321 
1322  if (Ctx) {
1323  DeclContext *OuterCtx;
1324  bool SearchAfterTemplateScope;
1325  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1326  if (SearchAfterTemplateScope)
1327  OutsideOfTemplateParamDC = OuterCtx;
1328 
1329  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1330  // We do not directly look into transparent contexts, since
1331  // those entities will be found in the nearest enclosing
1332  // non-transparent context.
1333  if (Ctx->isTransparentContext())
1334  continue;
1335 
1336  // We do not look directly into function or method contexts,
1337  // since all of the local variables and parameters of the
1338  // function/method are present within the Scope.
1339  if (Ctx->isFunctionOrMethod()) {
1340  // If we have an Objective-C instance method, look for ivars
1341  // in the corresponding interface.
1342  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1343  if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1344  if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1345  ObjCInterfaceDecl *ClassDeclared;
1346  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1347  Name.getAsIdentifierInfo(),
1348  ClassDeclared)) {
1349  if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1350  R.addDecl(ND);
1351  R.resolveKind();
1352  return true;
1353  }
1354  }
1355  }
1356  }
1357 
1358  continue;
1359  }
1360 
1361  // If this is a file context, we need to perform unqualified name
1362  // lookup considering using directives.
1363  if (Ctx->isFileContext()) {
1364  // If we haven't handled using directives yet, do so now.
1365  if (!VisitedUsingDirectives) {
1366  // Add using directives from this context up to the top level.
1367  for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1368  if (UCtx->isTransparentContext())
1369  continue;
1370 
1371  UDirs.visit(UCtx, UCtx);
1372  }
1373 
1374  // Find the innermost file scope, so we can add using directives
1375  // from local scopes.
1376  Scope *InnermostFileScope = S;
1377  while (InnermostFileScope &&
1378  !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1379  InnermostFileScope = InnermostFileScope->getParent();
1380  UDirs.visitScopeChain(Initial, InnermostFileScope);
1381 
1382  UDirs.done();
1383 
1384  VisitedUsingDirectives = true;
1385  }
1386 
1387  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1388  R.resolveKind();
1389  return true;
1390  }
1391 
1392  continue;
1393  }
1394 
1395  // Perform qualified name lookup into this context.
1396  // FIXME: In some cases, we know that every name that could be found by
1397  // this qualified name lookup will also be on the identifier chain. For
1398  // example, inside a class without any base classes, we never need to
1399  // perform qualified lookup because all of the members are on top of the
1400  // identifier chain.
1401  if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1402  return true;
1403  }
1404  }
1405  }
1406 
1407  // Stop if we ran out of scopes.
1408  // FIXME: This really, really shouldn't be happening.
1409  if (!S) return false;
1410 
1411  // If we are looking for members, no need to look into global/namespace scope.
1412  if (NameKind == LookupMemberName)
1413  return false;
1414 
1415  // Collect UsingDirectiveDecls in all scopes, and recursively all
1416  // nominated namespaces by those using-directives.
1417  //
1418  // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1419  // don't build it for each lookup!
1420  if (!VisitedUsingDirectives) {
1421  UDirs.visitScopeChain(Initial, S);
1422  UDirs.done();
1423  }
1424 
1425  // If we're not performing redeclaration lookup, do not look for local
1426  // extern declarations outside of a function scope.
1427  if (!R.isForRedeclaration())
1428  FindLocals.restore();
1429 
1430  // Lookup namespace scope, and global scope.
1431  // Unqualified name lookup in C++ requires looking into scopes
1432  // that aren't strictly lexical, and therefore we walk through the
1433  // context as well as walking through the scopes.
1434  for (; S; S = S->getParent()) {
1435  // Check whether the IdResolver has anything in this scope.
1436  bool Found = false;
1437  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1438  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1439  // We found something. Look for anything else in our scope
1440  // with this same name and in an acceptable identifier
1441  // namespace, so that we can construct an overload set if we
1442  // need to.
1443  Found = true;
1444  R.addDecl(ND);
1445  }
1446  }
1447 
1448  if (Found && S->isTemplateParamScope()) {
1449  R.resolveKind();
1450  return true;
1451  }
1452 
1453  DeclContext *Ctx = S->getEntity();
1454  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1455  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1456  // We've just searched the last template parameter scope and
1457  // found nothing, so look into the contexts between the
1458  // lexical and semantic declaration contexts returned by
1459  // findOuterContext(). This implements the name lookup behavior
1460  // of C++ [temp.local]p8.
1461  Ctx = OutsideOfTemplateParamDC;
1462  OutsideOfTemplateParamDC = nullptr;
1463  }
1464 
1465  if (Ctx) {
1466  DeclContext *OuterCtx;
1467  bool SearchAfterTemplateScope;
1468  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1469  if (SearchAfterTemplateScope)
1470  OutsideOfTemplateParamDC = OuterCtx;
1471 
1472  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1473  // We do not directly look into transparent contexts, since
1474  // those entities will be found in the nearest enclosing
1475  // non-transparent context.
1476  if (Ctx->isTransparentContext())
1477  continue;
1478 
1479  // If we have a context, and it's not a context stashed in the
1480  // template parameter scope for an out-of-line definition, also
1481  // look into that context.
1482  if (!(Found && S->isTemplateParamScope())) {
1483  assert(Ctx->isFileContext() &&
1484  "We should have been looking only at file context here already.");
1485 
1486  // Look into context considering using-directives.
1487  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1488  Found = true;
1489  }
1490 
1491  if (Found) {
1492  R.resolveKind();
1493  return true;
1494  }
1495 
1496  if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1497  return false;
1498  }
1499  }
1500 
1501  if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1502  return false;
1503  }
1504 
1505  return !R.empty();
1506 }
1507 
1509  if (auto *M = getCurrentModule())
1510  Context.mergeDefinitionIntoModule(ND, M);
1511  else
1512  // We're not building a module; just make the definition visible.
1514 
1515  // If ND is a template declaration, make the template parameters
1516  // visible too. They're not (necessarily) within a mergeable DeclContext.
1517  if (auto *TD = dyn_cast<TemplateDecl>(ND))
1518  for (auto *Param : *TD->getTemplateParameters())
1519  makeMergedDefinitionVisible(Param);
1520 }
1521 
1522 /// Find the module in which the given declaration was defined.
1523 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1524  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1525  // If this function was instantiated from a template, the defining module is
1526  // the module containing the pattern.
1527  if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1528  Entity = Pattern;
1529  } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1530  if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1531  Entity = Pattern;
1532  } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1533  if (auto *Pattern = ED->getTemplateInstantiationPattern())
1534  Entity = Pattern;
1535  } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1536  if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1537  Entity = Pattern;
1538  }
1539 
1540  // Walk up to the containing context. That might also have been instantiated
1541  // from a template.
1542  DeclContext *Context = Entity->getLexicalDeclContext();
1543  if (Context->isFileContext())
1544  return S.getOwningModule(Entity);
1545  return getDefiningModule(S, cast<Decl>(Context));
1546 }
1547 
1549  unsigned N = CodeSynthesisContexts.size();
1550  for (unsigned I = CodeSynthesisContextLookupModules.size();
1551  I != N; ++I) {
1552  Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1553  if (M && !LookupModulesCache.insert(M).second)
1554  M = nullptr;
1555  CodeSynthesisContextLookupModules.push_back(M);
1556  }
1557  return LookupModulesCache;
1558 }
1559 
1560 /// Determine whether the module M is part of the current module from the
1561 /// perspective of a module-private visibility check.
1562 static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts) {
1563  // If M is the global module fragment of a module that we've not yet finished
1564  // parsing, then it must be part of the current module.
1565  return M->getTopLevelModuleName() == LangOpts.CurrentModule ||
1566  (M->Kind == Module::GlobalModuleFragment && !M->Parent);
1567 }
1568 
1570  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1571  if (isModuleVisible(Merged))
1572  return true;
1573  return false;
1574 }
1575 
1577  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1578  if (isInCurrentModule(Merged, getLangOpts()))
1579  return true;
1580  return false;
1581 }
1582 
1583 template<typename ParmDecl>
1584 static bool
1585 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1587  if (!D->hasDefaultArgument())
1588  return false;
1589 
1590  while (D) {
1591  auto &DefaultArg = D->getDefaultArgStorage();
1592  if (!DefaultArg.isInherited() && S.isVisible(D))
1593  return true;
1594 
1595  if (!DefaultArg.isInherited() && Modules) {
1596  auto *NonConstD = const_cast<ParmDecl*>(D);
1597  Modules->push_back(S.getOwningModule(NonConstD));
1598  }
1599 
1600  // If there was a previous default argument, maybe its parameter is visible.
1601  D = DefaultArg.getInheritedFrom();
1602  }
1603  return false;
1604 }
1605 
1608  if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1609  return ::hasVisibleDefaultArgument(*this, P, Modules);
1610  if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1611  return ::hasVisibleDefaultArgument(*this, P, Modules);
1612  return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1613  Modules);
1614 }
1615 
1616 template<typename Filter>
1617 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1619  Filter F) {
1620  bool HasFilteredRedecls = false;
1621 
1622  for (auto *Redecl : D->redecls()) {
1623  auto *R = cast<NamedDecl>(Redecl);
1624  if (!F(R))
1625  continue;
1626 
1627  if (S.isVisible(R))
1628  return true;
1629 
1630  HasFilteredRedecls = true;
1631 
1632  if (Modules)
1633  Modules->push_back(R->getOwningModule());
1634  }
1635 
1636  // Only return false if there is at least one redecl that is not filtered out.
1637  if (HasFilteredRedecls)
1638  return false;
1639 
1640  return true;
1641 }
1642 
1644  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1645  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1646  if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1647  return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1648  if (auto *FD = dyn_cast<FunctionDecl>(D))
1649  return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1650  if (auto *VD = dyn_cast<VarDecl>(D))
1651  return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1652  llvm_unreachable("unknown explicit specialization kind");
1653  });
1654 }
1655 
1657  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1658  assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1659  "not a member specialization");
1660  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1661  // If the specialization is declared at namespace scope, then it's a member
1662  // specialization declaration. If it's lexically inside the class
1663  // definition then it was instantiated.
1664  //
1665  // FIXME: This is a hack. There should be a better way to determine this.
1666  // FIXME: What about MS-style explicit specializations declared within a
1667  // class definition?
1668  return D->getLexicalDeclContext()->isFileContext();
1669  });
1670 }
1671 
1672 /// Determine whether a declaration is visible to name lookup.
1673 ///
1674 /// This routine determines whether the declaration D is visible in the current
1675 /// lookup context, taking into account the current template instantiation
1676 /// stack. During template instantiation, a declaration is visible if it is
1677 /// visible from a module containing any entity on the template instantiation
1678 /// path (by instantiating a template, you allow it to see the declarations that
1679 /// your module can see, including those later on in your module).
1680 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1681  assert(D->isHidden() && "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.
2060  llvm::SmallPtrSet<DeclContext*, 8> Visited;
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 /// Callback that looks for any member of a class with the given name.
2132  CXXBasePath &Path, DeclarationName Name) {
2133  RecordDecl *BaseRecord = Specifier->getType()->castAs<RecordType>()->getDecl();
2134 
2135  Path.Decls = BaseRecord->lookup(Name);
2136  return !Path.Decls.empty();
2137 }
2138 
2139 /// Determine whether the given set of member declarations contains only
2140 /// static members, nested types, and enumerators.
2141 template<typename InputIterator>
2142 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
2143  Decl *D = (*First)->getUnderlyingDecl();
2144  if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
2145  return true;
2146 
2147  if (isa<CXXMethodDecl>(D)) {
2148  // Determine whether all of the methods are static.
2149  bool AllMethodsAreStatic = true;
2150  for(; First != Last; ++First) {
2151  D = (*First)->getUnderlyingDecl();
2152 
2153  if (!isa<CXXMethodDecl>(D)) {
2154  assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
2155  break;
2156  }
2157 
2158  if (!cast<CXXMethodDecl>(D)->isStatic()) {
2159  AllMethodsAreStatic = false;
2160  break;
2161  }
2162  }
2163 
2164  if (AllMethodsAreStatic)
2165  return true;
2166  }
2167 
2168  return false;
2169 }
2170 
2171 /// Perform qualified name lookup into a given context.
2172 ///
2173 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
2174 /// names when the context of those names is explicit specified, e.g.,
2175 /// "std::vector" or "x->member", or as part of unqualified name lookup.
2176 ///
2177 /// Different lookup criteria can find different names. For example, a
2178 /// particular scope can have both a struct and a function of the same
2179 /// name, and each can be found by certain lookup criteria. For more
2180 /// information about lookup criteria, see the documentation for the
2181 /// class LookupCriteria.
2182 ///
2183 /// \param R captures both the lookup criteria and any lookup results found.
2184 ///
2185 /// \param LookupCtx The context in which qualified name lookup will
2186 /// search. If the lookup criteria permits, name lookup may also search
2187 /// in the parent contexts or (for C++ classes) base classes.
2188 ///
2189 /// \param InUnqualifiedLookup true if this is qualified name lookup that
2190 /// occurs as part of unqualified name lookup.
2191 ///
2192 /// \returns true if lookup succeeded, false if it failed.
2194  bool InUnqualifiedLookup) {
2195  assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2196 
2197  if (!R.getLookupName())
2198  return false;
2199 
2200  // Make sure that the declaration context is complete.
2201  assert((!isa<TagDecl>(LookupCtx) ||
2202  LookupCtx->isDependentContext() ||
2203  cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
2204  cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
2205  "Declaration context must already be complete!");
2206 
2207  struct QualifiedLookupInScope {
2208  bool oldVal;
2209  DeclContext *Context;
2210  // Set flag in DeclContext informing debugger that we're looking for qualified name
2211  QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2212  oldVal = ctx->setUseQualifiedLookup();
2213  }
2214  ~QualifiedLookupInScope() {
2215  Context->setUseQualifiedLookup(oldVal);
2216  }
2217  } QL(LookupCtx);
2218 
2219  if (LookupDirect(*this, R, LookupCtx)) {
2220  R.resolveKind();
2221  if (isa<CXXRecordDecl>(LookupCtx))
2222  R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2223  return true;
2224  }
2225 
2226  // Don't descend into implied contexts for redeclarations.
2227  // C++98 [namespace.qual]p6:
2228  // In a declaration for a namespace member in which the
2229  // declarator-id is a qualified-id, given that the qualified-id
2230  // for the namespace member has the form
2231  // nested-name-specifier unqualified-id
2232  // the unqualified-id shall name a member of the namespace
2233  // designated by the nested-name-specifier.
2234  // See also [class.mfct]p5 and [class.static.data]p2.
2235  if (R.isForRedeclaration())
2236  return false;
2237 
2238  // If this is a namespace, look it up in the implied namespaces.
2239  if (LookupCtx->isFileContext())
2240  return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2241 
2242  // If this isn't a C++ class, we aren't allowed to look into base
2243  // classes, we're done.
2244  CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2245  if (!LookupRec || !LookupRec->getDefinition())
2246  return false;
2247 
2248  // If we're performing qualified name lookup into a dependent class,
2249  // then we are actually looking into a current instantiation. If we have any
2250  // dependent base classes, then we either have to delay lookup until
2251  // template instantiation time (at which point all bases will be available)
2252  // or we have to fail.
2253  if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2254  LookupRec->hasAnyDependentBases()) {
2256  return false;
2257  }
2258 
2259  // Perform lookup into our base classes.
2260  CXXBasePaths Paths;
2261  Paths.setOrigin(LookupRec);
2262 
2263  // Look for this member in our base classes
2264  bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2265  DeclarationName Name) = nullptr;
2266  switch (R.getLookupKind()) {
2267  case LookupObjCImplicitSelfParam:
2268  case LookupOrdinaryName:
2269  case LookupMemberName:
2270  case LookupRedeclarationWithLinkage:
2271  case LookupLocalFriendName:
2272  BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2273  break;
2274 
2275  case LookupTagName:
2276  BaseCallback = &CXXRecordDecl::FindTagMember;
2277  break;
2278 
2279  case LookupAnyName:
2280  BaseCallback = &LookupAnyMember;
2281  break;
2282 
2283  case LookupOMPReductionName:
2284  BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2285  break;
2286 
2287  case LookupOMPMapperName:
2288  BaseCallback = &CXXRecordDecl::FindOMPMapperMember;
2289  break;
2290 
2291  case LookupUsingDeclName:
2292  // This lookup is for redeclarations only.
2293 
2294  case LookupOperatorName:
2295  case LookupNamespaceName:
2296  case LookupObjCProtocolName:
2297  case LookupLabel:
2298  // These lookups will never find a member in a C++ class (or base class).
2299  return false;
2300 
2301  case LookupNestedNameSpecifierName:
2303  break;
2304  }
2305 
2306  DeclarationName Name = R.getLookupName();
2307  if (!LookupRec->lookupInBases(
2308  [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2309  return BaseCallback(Specifier, Path, Name);
2310  },
2311  Paths))
2312  return false;
2313 
2314  R.setNamingClass(LookupRec);
2315 
2316  // C++ [class.member.lookup]p2:
2317  // [...] If the resulting set of declarations are not all from
2318  // sub-objects of the same type, or the set has a nonstatic member
2319  // and includes members from distinct sub-objects, there is an
2320  // ambiguity and the program is ill-formed. Otherwise that set is
2321  // the result of the lookup.
2322  QualType SubobjectType;
2323  int SubobjectNumber = 0;
2324  AccessSpecifier SubobjectAccess = AS_none;
2325 
2326  for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2327  Path != PathEnd; ++Path) {
2328  const CXXBasePathElement &PathElement = Path->back();
2329 
2330  // Pick the best (i.e. most permissive i.e. numerically lowest) access
2331  // across all paths.
2332  SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2333 
2334  // Determine whether we're looking at a distinct sub-object or not.
2335  if (SubobjectType.isNull()) {
2336  // This is the first subobject we've looked at. Record its type.
2337  SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2338  SubobjectNumber = PathElement.SubobjectNumber;
2339  continue;
2340  }
2341 
2342  if (SubobjectType
2343  != Context.getCanonicalType(PathElement.Base->getType())) {
2344  // We found members of the given name in two subobjects of
2345  // different types. If the declaration sets aren't the same, this
2346  // lookup is ambiguous.
2347  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2348  CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2349  DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2350  DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2351 
2352  // Get the decl that we should use for deduplicating this lookup.
2353  auto GetRepresentativeDecl = [&](NamedDecl *D) -> Decl * {
2354  // C++ [temp.local]p3:
2355  // A lookup that finds an injected-class-name (10.2) can result in
2356  // an ambiguity in certain cases (for example, if it is found in
2357  // more than one base class). If all of the injected-class-names
2358  // that are found refer to specializations of the same class
2359  // template, and if the name is used as a template-name, the
2360  // reference refers to the class template itself and not a
2361  // specialization thereof, and is not ambiguous.
2362  if (R.isTemplateNameLookup())
2363  if (auto *TD = getAsTemplateNameDecl(D))
2364  D = TD;
2365  return D->getUnderlyingDecl()->getCanonicalDecl();
2366  };
2367 
2368  while (FirstD != FirstPath->Decls.end() &&
2369  CurrentD != Path->Decls.end()) {
2370  if (GetRepresentativeDecl(*FirstD) !=
2371  GetRepresentativeDecl(*CurrentD))
2372  break;
2373 
2374  ++FirstD;
2375  ++CurrentD;
2376  }
2377 
2378  if (FirstD == FirstPath->Decls.end() &&
2379  CurrentD == Path->Decls.end())
2380  continue;
2381  }
2382 
2384  return true;
2385  }
2386 
2387  if (SubobjectNumber != PathElement.SubobjectNumber) {
2388  // We have a different subobject of the same type.
2389 
2390  // C++ [class.member.lookup]p5:
2391  // A static member, a nested type or an enumerator defined in
2392  // a base class T can unambiguously be found even if an object
2393  // has more than one base class subobject of type T.
2394  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2395  continue;
2396 
2397  // We have found a nonstatic member name in multiple, distinct
2398  // subobjects. Name lookup is ambiguous.
2399  R.setAmbiguousBaseSubobjects(Paths);
2400  return true;
2401  }
2402  }
2403 
2404  // Lookup in a base class succeeded; return these results.
2405 
2406  for (auto *D : Paths.front().Decls) {
2407  AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2408  D->getAccess());
2409  R.addDecl(D, AS);
2410  }
2411  R.resolveKind();
2412  return true;
2413 }
2414 
2415 /// Performs qualified name lookup or special type of lookup for
2416 /// "__super::" scope specifier.
2417 ///
2418 /// This routine is a convenience overload meant to be called from contexts
2419 /// that need to perform a qualified name lookup with an optional C++ scope
2420 /// specifier that might require special kind of lookup.
2421 ///
2422 /// \param R captures both the lookup criteria and any lookup results found.
2423 ///
2424 /// \param LookupCtx The context in which qualified name lookup will
2425 /// search.
2426 ///
2427 /// \param SS An optional C++ scope-specifier.
2428 ///
2429 /// \returns true if lookup succeeded, false if it failed.
2431  CXXScopeSpec &SS) {
2432  auto *NNS = SS.getScopeRep();
2433  if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2434  return LookupInSuper(R, NNS->getAsRecordDecl());
2435  else
2436 
2437  return LookupQualifiedName(R, LookupCtx);
2438 }
2439 
2440 /// Performs name lookup for a name that was parsed in the
2441 /// source code, and may contain a C++ scope specifier.
2442 ///
2443 /// This routine is a convenience routine meant to be called from
2444 /// contexts that receive a name and an optional C++ scope specifier
2445 /// (e.g., "N::M::x"). It will then perform either qualified or
2446 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2447 /// respectively) on the given name and return those results. It will
2448 /// perform a special type of lookup for "__super::" scope specifier.
2449 ///
2450 /// @param S The scope from which unqualified name lookup will
2451 /// begin.
2452 ///
2453 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2454 ///
2455 /// @param EnteringContext Indicates whether we are going to enter the
2456 /// context of the scope-specifier SS (if present).
2457 ///
2458 /// @returns True if any decls were found (but possibly ambiguous)
2460  bool AllowBuiltinCreation, bool EnteringContext) {
2461  if (SS && SS->isInvalid()) {
2462  // When the scope specifier is invalid, don't even look for
2463  // anything.
2464  return false;
2465  }
2466 
2467  if (SS && SS->isSet()) {
2468  NestedNameSpecifier *NNS = SS->getScopeRep();
2469  if (NNS->getKind() == NestedNameSpecifier::Super)
2470  return LookupInSuper(R, NNS->getAsRecordDecl());
2471 
2472  if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2473  // We have resolved the scope specifier to a particular declaration
2474  // contex, and will perform name lookup in that context.
2475  if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2476  return false;
2477 
2478  R.setContextRange(SS->getRange());
2479  return LookupQualifiedName(R, DC);
2480  }
2481 
2482  // We could not resolve the scope specified to a specific declaration
2483  // context, which means that SS refers to an unknown specialization.
2484  // Name lookup can't find anything in this case.
2486  R.setContextRange(SS->getRange());
2487  return false;
2488  }
2489 
2490  // Perform unqualified name lookup starting in the given scope.
2491  return LookupName(R, S, AllowBuiltinCreation);
2492 }
2493 
2494 /// Perform qualified name lookup into all base classes of the given
2495 /// class.
2496 ///
2497 /// \param R captures both the lookup criteria and any lookup results found.
2498 ///
2499 /// \param Class The context in which qualified name lookup will
2500 /// search. Name lookup will search in all base classes merging the results.
2501 ///
2502 /// @returns True if any decls were found (but possibly ambiguous)
2504  // The access-control rules we use here are essentially the rules for
2505  // doing a lookup in Class that just magically skipped the direct
2506  // members of Class itself. That is, the naming class is Class, and the
2507  // access includes the access of the base.
2508  for (const auto &BaseSpec : Class->bases()) {
2509  CXXRecordDecl *RD = cast<CXXRecordDecl>(
2510  BaseSpec.getType()->castAs<RecordType>()->getDecl());
2511  LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2512  Result.setBaseObjectType(Context.getRecordType(Class));
2513  LookupQualifiedName(Result, RD);
2514 
2515  // Copy the lookup results into the target, merging the base's access into
2516  // the path access.
2517  for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2518  R.addDecl(I.getDecl(),
2519  CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2520  I.getAccess()));
2521  }
2522 
2523  Result.suppressDiagnostics();
2524  }
2525 
2526  R.resolveKind();
2527  R.setNamingClass(Class);
2528 
2529  return !R.empty();
2530 }
2531 
2532 /// Produce a diagnostic describing the ambiguity that resulted
2533 /// from name lookup.
2534 ///
2535 /// \param Result The result of the ambiguous lookup to be diagnosed.
2537  assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2538 
2539  DeclarationName Name = Result.getLookupName();
2540  SourceLocation NameLoc = Result.getNameLoc();
2541  SourceRange LookupRange = Result.getContextRange();
2542 
2543  switch (Result.getAmbiguityKind()) {
2545  CXXBasePaths *Paths = Result.getBasePaths();
2546  QualType SubobjectType = Paths->front().back().Base->getType();
2547  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2548  << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2549  << LookupRange;
2550 
2551  DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2552  while (isa<CXXMethodDecl>(*Found) &&
2553  cast<CXXMethodDecl>(*Found)->isStatic())
2554  ++Found;
2555 
2556  Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2557  break;
2558  }
2559 
2561  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2562  << Name << LookupRange;
2563 
2564  CXXBasePaths *Paths = Result.getBasePaths();
2565  std::set<Decl *> DeclsPrinted;
2566  for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2567  PathEnd = Paths->end();
2568  Path != PathEnd; ++Path) {
2569  Decl *D = Path->Decls.front();
2570  if (DeclsPrinted.insert(D).second)
2571  Diag(D->getLocation(), diag::note_ambiguous_member_found);
2572  }
2573  break;
2574  }
2575 
2577  Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2578 
2579  llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
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::Complex:
2937  break;
2938 
2939  // Non-deduced auto types only get here for error cases.
2940  case Type::Auto:
2941  case Type::DeducedTemplateSpecialization:
2942  break;
2943 
2944  // If T is an Objective-C object or interface type, or a pointer to an
2945  // object or interface type, the associated namespace is the global
2946  // namespace.
2947  case Type::ObjCObject:
2948  case Type::ObjCInterface:
2949  case Type::ObjCObjectPointer:
2950  Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2951  break;
2952 
2953  // Atomic types are just wrappers; use the associations of the
2954  // contained type.
2955  case Type::Atomic:
2956  T = cast<AtomicType>(T)->getValueType().getTypePtr();
2957  continue;
2958  case Type::Pipe:
2959  T = cast<PipeType>(T)->getElementType().getTypePtr();
2960  continue;
2961  }
2962 
2963  if (Queue.empty())
2964  break;
2965  T = Queue.pop_back_val();
2966  }
2967 }
2968 
2969 /// Find the associated classes and namespaces for
2970 /// argument-dependent lookup for a call with the given set of
2971 /// arguments.
2972 ///
2973 /// This routine computes the sets of associated classes and associated
2974 /// namespaces searched by argument-dependent lookup
2975 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2977  SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2978  AssociatedNamespaceSet &AssociatedNamespaces,
2979  AssociatedClassSet &AssociatedClasses) {
2980  AssociatedNamespaces.clear();
2981  AssociatedClasses.clear();
2982 
2983  AssociatedLookup Result(*this, InstantiationLoc,
2984  AssociatedNamespaces, AssociatedClasses);
2985 
2986  // C++ [basic.lookup.koenig]p2:
2987  // For each argument type T in the function call, there is a set
2988  // of zero or more associated namespaces and a set of zero or more
2989  // associated classes to be considered. The sets of namespaces and
2990  // classes is determined entirely by the types of the function
2991  // arguments (and the namespace of any template template
2992  // argument).
2993  for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2994  Expr *Arg = Args[ArgIdx];
2995 
2996  if (Arg->getType() != Context.OverloadTy) {
2998  continue;
2999  }
3000 
3001  // [...] In addition, if the argument is the name or address of a
3002  // set of overloaded functions and/or function templates, its
3003  // associated classes and namespaces are the union of those
3004  // associated with each of the members of the set: the namespace
3005  // in which the function or function template is defined and the
3006  // classes and namespaces associated with its (non-dependent)
3007  // parameter types and return type.
3009 
3010  for (const NamedDecl *D : OE->decls()) {
3011  // Look through any using declarations to find the underlying function.
3012  const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
3013 
3014  // Add the classes and namespaces associated with the parameter
3015  // types and return type of this function.
3016  addAssociatedClassesAndNamespaces(Result, FDecl->getType());
3017  }
3018  }
3019 }
3020 
3022  SourceLocation Loc,
3023  LookupNameKind NameKind,
3024  RedeclarationKind Redecl) {
3025  LookupResult R(*this, Name, Loc, NameKind, Redecl);
3026  LookupName(R, S);
3027  return R.getAsSingle<NamedDecl>();
3028 }
3029 
3030 /// Find the protocol with the given name, if any.
3032  SourceLocation IdLoc,
3033  RedeclarationKind Redecl) {
3034  Decl *D = LookupSingleName(TUScope, II, IdLoc,
3035  LookupObjCProtocolName, Redecl);
3036  return cast_or_null<ObjCProtocolDecl>(D);
3037 }
3038 
3040  QualType T1, QualType T2,
3041  UnresolvedSetImpl &Functions) {
3042  // C++ [over.match.oper]p3:
3043  // -- The set of non-member candidates is the result of the
3044  // unqualified lookup of operator@ in the context of the
3045  // expression according to the usual rules for name lookup in
3046  // unqualified function calls (3.4.2) except that all member
3047  // functions are ignored.
3049  LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
3050  LookupName(Operators, S);
3051 
3052  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
3053  Functions.append(Operators.begin(), Operators.end());
3054 }
3055 
3058  bool ConstArg,
3059  bool VolatileArg,
3060  bool RValueThis,
3061  bool ConstThis,
3062  bool VolatileThis) {
3063  assert(CanDeclareSpecialMemberFunction(RD) &&
3064  "doing special member lookup into record that isn't fully complete");
3065  RD = RD->getDefinition();
3066  if (RValueThis || ConstThis || VolatileThis)
3067  assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
3068  "constructors and destructors always have unqualified lvalue this");
3069  if (ConstArg || VolatileArg)
3070  assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
3071  "parameter-less special members can't have qualified arguments");
3072 
3073  // FIXME: Get the caller to pass in a location for the lookup.
3074  SourceLocation LookupLoc = RD->getLocation();
3075 
3076  llvm::FoldingSetNodeID ID;
3077  ID.AddPointer(RD);
3078  ID.AddInteger(SM);
3079  ID.AddInteger(ConstArg);
3080  ID.AddInteger(VolatileArg);
3081  ID.AddInteger(RValueThis);
3082  ID.AddInteger(ConstThis);
3083  ID.AddInteger(VolatileThis);
3084 
3085  void *InsertPoint;
3087  SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
3088 
3089  // This was already cached
3090  if (Result)
3091  return *Result;
3092 
3093  Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3094  Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3095  SpecialMemberCache.InsertNode(Result, InsertPoint);
3096 
3097  if (SM == CXXDestructor) {
3098  if (RD->needsImplicitDestructor()) {
3100  DeclareImplicitDestructor(RD);
3101  });
3102  }
3103  CXXDestructorDecl *DD = RD->getDestructor();
3104  assert(DD && "record without a destructor");
3105  Result->setMethod(DD);
3106  Result->setKind(DD->isDeleted() ?
3107  SpecialMemberOverloadResult::NoMemberOrDeleted :
3108  SpecialMemberOverloadResult::Success);
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.
3114  CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
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) {
3123  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3124  NumArgs = 0;
3125  if (RD->needsImplicitDefaultConstructor()) {
3127  DeclareImplicitDefaultConstructor(RD);
3128  });
3129  }
3130  } else {
3131  if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
3132  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3133  if (RD->needsImplicitCopyConstructor()) {
3135  DeclareImplicitCopyConstructor(RD);
3136  });
3137  }
3138  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) {
3140  DeclareImplicitMoveConstructor(RD);
3141  });
3142  }
3143  } else {
3144  Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
3145  if (RD->needsImplicitCopyAssignment()) {
3147  DeclareImplicitCopyAssignment(RD);
3148  });
3149  }
3150  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) {
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 an RValue 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.
3169  if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
3170  VK = VK_LValue;
3171  else
3172  VK = VK_RValue;
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,
3190  RValueThis ? VK_RValue : VK_LValue).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);
3206  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
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())) {
3221  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
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())) {
3233  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3234  AddMethodTemplateCandidate(
3235  Tmpl, Cand, RD, nullptr, ThisTy, Classification,
3236  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3237  else if (CtorInfo)
3238  AddTemplateOverloadCandidate(
3239  CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
3240  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3241  else
3242  AddTemplateOverloadCandidate(
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));
3259  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
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);
3269  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
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");
3291  LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
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) {
3301  LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
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)) {
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 
3321  CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
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");
3335  LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
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");
3351  LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
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,
3380  bool AllowRaw, bool AllowTemplate,
3381  bool AllowStringTemplate, bool DiagnoseMissing) {
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 FoundRaw = false;
3390  bool FoundTemplate = false;
3391  bool FoundStringTemplate = false;
3392  bool FoundExactMatch = false;
3393 
3394  while (F.hasNext()) {
3395  Decl *D = F.next();
3396  if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3397  D = USD->getTargetDecl();
3398 
3399  // If the declaration we found is invalid, skip it.
3400  if (D->isInvalidDecl()) {
3401  F.erase();
3402  continue;
3403  }
3404 
3405  bool IsRaw = false;
3406  bool IsTemplate = false;
3407  bool IsStringTemplate = false;
3408  bool IsExactMatch = false;
3409 
3410  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3411  if (FD->getNumParams() == 1 &&
3412  FD->getParamDecl(0)->getType()->getAs<PointerType>())
3413  IsRaw = true;
3414  else if (FD->getNumParams() == ArgTys.size()) {
3415  IsExactMatch = true;
3416  for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3417  QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3418  if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3419  IsExactMatch = false;
3420  break;
3421  }
3422  }
3423  }
3424  }
3425  if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3426  TemplateParameterList *Params = FD->getTemplateParameters();
3427  if (Params->size() == 1)
3428  IsTemplate = true;
3429  else
3430  IsStringTemplate = true;
3431  }
3432 
3433  if (IsExactMatch) {
3434  FoundExactMatch = true;
3435  AllowRaw = false;
3436  AllowTemplate = false;
3437  AllowStringTemplate = false;
3438  if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3439  // Go through again and remove the raw and template decls we've
3440  // already found.
3441  F.restart();
3442  FoundRaw = FoundTemplate = FoundStringTemplate = false;
3443  }
3444  } else if (AllowRaw && IsRaw) {
3445  FoundRaw = true;
3446  } else if (AllowTemplate && IsTemplate) {
3447  FoundTemplate = true;
3448  } else if (AllowStringTemplate && IsStringTemplate) {
3449  FoundStringTemplate = true;
3450  } else {
3451  F.erase();
3452  }
3453  }
3454 
3455  F.done();
3456 
3457  // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3458  // parameter type, that is used in preference to a raw literal operator
3459  // or literal operator template.
3460  if (FoundExactMatch)
3461  return LOLR_Cooked;
3462 
3463  // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3464  // operator template, but not both.
3465  if (FoundRaw && FoundTemplate) {
3466  Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3467  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3468  NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3469  return LOLR_Error;
3470  }
3471 
3472  if (FoundRaw)
3473  return LOLR_Raw;
3474 
3475  if (FoundTemplate)
3476  return LOLR_Template;
3477 
3478  if (FoundStringTemplate)
3479  return LOLR_StringTemplate;
3480 
3481  // Didn't find anything we could use.
3482  if (DiagnoseMissing) {
3483  Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3484  << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3485  << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3486  << (AllowTemplate || AllowStringTemplate);
3487  return LOLR_Error;
3488  }
3489 
3490  return LOLR_ErrorNoDiagnostic;
3491 }
3492 
3494  NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3495 
3496  // If we haven't yet seen a decl for this key, or the last decl
3497  // was exactly this one, we're done.
3498  if (Old == nullptr || Old == New) {
3499  Old = New;
3500  return;
3501  }
3502 
3503  // Otherwise, decide which is a more recent redeclaration.
3504  FunctionDecl *OldFD = Old->getAsFunction();
3505  FunctionDecl *NewFD = New->getAsFunction();
3506 
3507  FunctionDecl *Cursor = NewFD;
3508  while (true) {
3509  Cursor = Cursor->getPreviousDecl();
3510 
3511  // If we got to the end without finding OldFD, OldFD is the newer
3512  // declaration; leave things as they are.
3513  if (!Cursor) return;
3514 
3515  // If we do find OldFD, then NewFD is newer.
3516  if (Cursor == OldFD) break;
3517 
3518  // Otherwise, keep looking.
3519  }
3520 
3521  Old = New;
3522 }
3523 
3525  ArrayRef<Expr *> Args, ADLResult &Result) {
3526  // Find all of the associated namespaces and classes based on the
3527  // arguments we have.
3528  AssociatedNamespaceSet AssociatedNamespaces;
3529  AssociatedClassSet AssociatedClasses;
3530  FindAssociatedClassesAndNamespaces(Loc, Args,
3531  AssociatedNamespaces,
3532  AssociatedClasses);
3533 
3534  // C++ [basic.lookup.argdep]p3:
3535  // Let X be the lookup set produced by unqualified lookup (3.4.1)
3536  // and let Y be the lookup set produced by argument dependent
3537  // lookup (defined as follows). If X contains [...] then Y is
3538  // empty. Otherwise Y is the set of declarations found in the
3539  // namespaces associated with the argument types as described
3540  // below. The set of declarations found by the lookup of the name
3541  // is the union of X and Y.
3542  //
3543  // Here, we compute Y and add its members to the overloaded
3544  // candidate set.
3545  for (auto *NS : AssociatedNamespaces) {
3546  // When considering an associated namespace, the lookup is the
3547  // same as the lookup performed when the associated namespace is
3548  // used as a qualifier (3.4.3.2) except that:
3549  //
3550  // -- Any using-directives in the associated namespace are
3551  // ignored.
3552  //
3553  // -- Any namespace-scope friend functions declared in
3554  // associated classes are visible within their respective
3555  // namespaces even if they are not visible during an ordinary
3556  // lookup (11.4).
3557  DeclContext::lookup_result R = NS->lookup(Name);
3558  for (auto *D : R) {
3559  auto *Underlying = D;
3560  if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3561  Underlying = USD->getTargetDecl();
3562 
3563  if (!isa<FunctionDecl>(Underlying) &&
3564  !isa<FunctionTemplateDecl>(Underlying))
3565  continue;
3566 
3567  // The declaration is visible to argument-dependent lookup if either
3568  // it's ordinarily visible or declared as a friend in an associated
3569  // class.
3570  bool Visible = false;
3571  for (D = D->getMostRecentDecl(); D;
3572  D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
3574  if (isVisible(D)) {
3575  Visible = true;
3576  break;
3577  }
3578  } else if (D->getFriendObjectKind()) {
3579  auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
3580  if (AssociatedClasses.count(RD) && isVisible(D)) {
3581  Visible = true;
3582  break;
3583  }
3584  }
3585  }
3586 
3587  // FIXME: Preserve D as the FoundDecl.
3588  if (Visible)
3589  Result.insert(Underlying);
3590  }
3591  }
3592 }
3593 
3594 //----------------------------------------------------------------------------
3595 // Search for all visible declarations.
3596 //----------------------------------------------------------------------------
3598 
3599 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3600 
3601 namespace {
3602 
3603 class ShadowContextRAII;
3604 
3605 class VisibleDeclsRecord {
3606 public:
3607  /// An entry in the shadow map, which is optimized to store a
3608  /// single declaration (the common case) but can also store a list
3609  /// of declarations.
3610  typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3611 
3612 private:
3613  /// A mapping from declaration names to the declarations that have
3614  /// this name within a particular scope.
3615  typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3616 
3617  /// A list of shadow maps, which is used to model name hiding.
3618  std::list<ShadowMap> ShadowMaps;
3619 
3620  /// The declaration contexts we have already visited.
3621  llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3622 
3623  friend class ShadowContextRAII;
3624 
3625 public:
3626  /// Determine whether we have already visited this context
3627  /// (and, if not, note that we are going to visit that context now).
3628  bool visitedContext(DeclContext *Ctx) {
3629  return !VisitedContexts.insert(Ctx).second;
3630  }
3631 
3632  bool alreadyVisitedContext(DeclContext *Ctx) {
3633  return VisitedContexts.count(Ctx);
3634  }
3635 
3636  /// Determine whether the given declaration is hidden in the
3637  /// current scope.
3638  ///
3639  /// \returns the declaration that hides the given declaration, or
3640  /// NULL if no such declaration exists.
3641  NamedDecl *checkHidden(NamedDecl *ND);
3642 
3643  /// Add a declaration to the current shadow map.
3644  void add(NamedDecl *ND) {
3645  ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3646  }
3647 };
3648 
3649 /// RAII object that records when we've entered a shadow context.
3650 class ShadowContextRAII {
3651  VisibleDeclsRecord &Visible;
3652 
3653  typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3654 
3655 public:
3656  ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3657  Visible.ShadowMaps.emplace_back();
3658  }
3659 
3660  ~ShadowContextRAII() {
3661  Visible.ShadowMaps.pop_back();
3662  }
3663 };
3664 
3665 } // end anonymous namespace
3666 
3667 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3668  unsigned IDNS = ND->getIdentifierNamespace();
3669  std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3670  for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3671  SM != SMEnd; ++SM) {
3672  ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3673  if (Pos == SM->end())
3674  continue;
3675 
3676  for (auto *D : Pos->second) {
3677  // A tag declaration does not hide a non-tag declaration.
3678  if (D->hasTagIdentifierNamespace() &&
3681  continue;
3682 
3683  // Protocols are in distinct namespaces from everything else.
3685  || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3686  D->getIdentifierNamespace() != IDNS)
3687  continue;
3688 
3689  // Functions and function templates in the same scope overload
3690  // rather than hide. FIXME: Look for hiding based on function
3691  // signatures!
3694  SM == ShadowMaps.rbegin())
3695  continue;
3696 
3697  // A shadow declaration that's created by a resolved using declaration
3698  // is not hidden by the same using declaration.
3699  if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3700  cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3701  continue;
3702 
3703  // We've found a declaration that hides this one.
3704  return D;
3705  }
3706  }
3707 
3708  return nullptr;
3709 }
3710 
3711 namespace {
3712 class LookupVisibleHelper {
3713 public:
3714  LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
3715  bool LoadExternal)
3716  : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
3717  LoadExternal(LoadExternal) {}
3718 
3719  void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind,
3720  bool IncludeGlobalScope) {
3721  // Determine the set of using directives available during
3722  // unqualified name lookup.
3723  Scope *Initial = S;
3724  UnqualUsingDirectiveSet UDirs(SemaRef);
3725  if (SemaRef.getLangOpts().CPlusPlus) {
3726  // Find the first namespace or translation-unit scope.
3727  while (S && !isNamespaceOrTranslationUnitScope(S))
3728  S = S->getParent();
3729 
3730  UDirs.visitScopeChain(Initial, S);
3731  }
3732  UDirs.done();
3733 
3734  // Look for visible declarations.
3735  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3736  Result.setAllowHidden(Consumer.includeHiddenDecls());
3737  if (!IncludeGlobalScope)
3738  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3739  ShadowContextRAII Shadow(Visited);
3740  lookupInScope(Initial, Result, UDirs);
3741  }
3742 
3743  void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
3744  Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
3745  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3746  Result.setAllowHidden(Consumer.includeHiddenDecls());
3747  if (!IncludeGlobalScope)
3748  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3749 
3750  ShadowContextRAII Shadow(Visited);
3751  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
3752  /*InBaseClass=*/false);
3753  }
3754 
3755 private:
3756  void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
3757  bool QualifiedNameLookup, bool InBaseClass) {
3758  if (!Ctx)
3759  return;
3760 
3761  // Make sure we don't visit the same context twice.
3762  if (Visited.visitedContext(Ctx->getPrimaryContext()))
3763  return;
3764 
3765  Consumer.EnteredContext(Ctx);
3766 
3767  // Outside C++, lookup results for the TU live on identifiers.
3768  if (isa<TranslationUnitDecl>(Ctx) &&
3769  !Result.getSema().getLangOpts().CPlusPlus) {
3770  auto &S = Result.getSema();
3771  auto &Idents = S.Context.Idents;
3772 
3773  // Ensure all external identifiers are in the identifier table.
3774  if (LoadExternal)
3775  if (IdentifierInfoLookup *External =
3776  Idents.getExternalIdentifierLookup()) {
3777  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3778  for (StringRef Name = Iter->Next(); !Name.empty();
3779  Name = Iter->Next())
3780  Idents.get(Name);
3781  }
3782 
3783  // Walk all lookup results in the TU for each identifier.
3784  for (const auto &Ident : Idents) {
3785  for (auto I = S.IdResolver.begin(Ident.getValue()),
3786  E = S.IdResolver.end();
3787  I != E; ++I) {
3788  if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3789  if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3790  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3791  Visited.add(ND);
3792  }
3793  }
3794  }
3795  }
3796 
3797  return;
3798  }
3799 
3800  if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3802 
3803  // We sometimes skip loading namespace-level results (they tend to be huge).
3804  bool Load = LoadExternal ||
3805  !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
3806  // Enumerate all of the results in this context.
3807  for (DeclContextLookupResult R :
3808  Load ? Ctx->lookups()
3809  : Ctx->noload_lookups(/*PreserveInternalState=*/false)) {
3810  for (auto *D : R) {
3811  if (auto *ND = Result.getAcceptableDecl(D)) {
3812  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3813  Visited.add(ND);
3814  }
3815  }
3816  }
3817 
3818  // Traverse using directives for qualified name lookup.
3819  if (QualifiedNameLookup) {
3820  ShadowContextRAII Shadow(Visited);
3821  for (auto I : Ctx->using_directives()) {
3822  if (!Result.getSema().isVisible(I))
3823  continue;
3824  lookupInDeclContext(I->getNominatedNamespace(), Result,
3825  QualifiedNameLookup, InBaseClass);
3826  }
3827  }
3828 
3829  // Traverse the contexts of inherited C++ classes.
3830  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3831  if (!Record->hasDefinition())
3832  return;
3833 
3834  for (const auto &B : Record->bases()) {
3835  QualType BaseType = B.getType();
3836 
3837  RecordDecl *RD;
3838  if (BaseType->isDependentType()) {
3839  if (!IncludeDependentBases) {
3840  // Don't look into dependent bases, because name lookup can't look
3841  // there anyway.
3842  continue;
3843  }
3844  const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3845  if (!TST)
3846  continue;
3847  TemplateName TN = TST->getTemplateName();
3848  const auto *TD =
3849  dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3850  if (!TD)
3851  continue;
3852  RD = TD->getTemplatedDecl();
3853  } else {
3854  const auto *Record = BaseType->getAs<RecordType>();
3855  if (!Record)
3856  continue;
3857  RD = Record->getDecl();
3858  }
3859 
3860  // FIXME: It would be nice to be able to determine whether referencing
3861  // a particular member would be ambiguous. For example, given
3862  //
3863  // struct A { int member; };
3864  // struct B { int member; };
3865  // struct C : A, B { };
3866  //
3867  // void f(C *c) { c->### }
3868  //
3869  // accessing 'member' would result in an ambiguity. However, we
3870  // could be smart enough to qualify the member with the base
3871  // class, e.g.,
3872  //
3873  // c->B::member
3874  //
3875  // or
3876  //
3877  // c->A::member
3878 
3879  // Find results in this base class (and its bases).
3880  ShadowContextRAII Shadow(Visited);
3881  lookupInDeclContext(RD, Result, QualifiedNameLookup,
3882  /*InBaseClass=*/true);
3883  }
3884  }
3885 
3886  // Traverse the contexts of Objective-C classes.
3887  if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3888  // Traverse categories.
3889  for (auto *Cat : IFace->visible_categories()) {
3890  ShadowContextRAII Shadow(Visited);
3891  lookupInDeclContext(Cat, Result, QualifiedNameLookup,
3892  /*InBaseClass=*/false);
3893  }
3894 
3895  // Traverse protocols.
3896  for (auto *I : IFace->all_referenced_protocols()) {
3897  ShadowContextRAII Shadow(Visited);
3898  lookupInDeclContext(I, Result, QualifiedNameLookup,
3899  /*InBaseClass=*/false);
3900  }
3901 
3902  // Traverse the superclass.
3903  if (IFace->getSuperClass()) {
3904  ShadowContextRAII Shadow(Visited);
3905  lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup,
3906  /*InBaseClass=*/true);
3907  }
3908 
3909  // If there is an implementation, traverse it. We do this to find
3910  // synthesized ivars.
3911  if (IFace->getImplementation()) {
3912  ShadowContextRAII Shadow(Visited);
3913  lookupInDeclContext(IFace->getImplementation(), Result,
3914  QualifiedNameLookup, InBaseClass);
3915  }
3916  } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3917  for (auto *I : Protocol->protocols()) {
3918  ShadowContextRAII Shadow(Visited);
3919  lookupInDeclContext(I, Result, QualifiedNameLookup,
3920  /*InBaseClass=*/false);
3921  }
3922  } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3923  for (auto *I : Category->protocols()) {
3924  ShadowContextRAII Shadow(Visited);
3925  lookupInDeclContext(I, Result, QualifiedNameLookup,
3926  /*InBaseClass=*/false);
3927  }
3928 
3929  // If there is an implementation, traverse it.
3930  if (Category->getImplementation()) {
3931  ShadowContextRAII Shadow(Visited);
3932  lookupInDeclContext(Category->getImplementation(), Result,
3933  QualifiedNameLookup, /*InBaseClass=*/true);
3934  }
3935  }
3936  }
3937 
3938  void lookupInScope(Scope *S, LookupResult &Result,
3939  UnqualUsingDirectiveSet &UDirs) {
3940  // No clients run in this mode and it's not supported. Please add tests and
3941  // remove the assertion if you start relying on it.
3942  assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
3943 
3944  if (!S)
3945  return;
3946 
3947  if (!S->getEntity() ||
3948  (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) ||
3949  (S->getEntity())->isFunctionOrMethod()) {
3950  FindLocalExternScope FindLocals(Result);
3951  // Walk through the declarations in this Scope. The consumer might add new
3952  // decls to the scope as part of deserialization, so make a copy first.
3953  SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
3954  for (Decl *D : ScopeDecls) {
3955  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3956  if ((ND = Result.getAcceptableDecl(ND))) {
3957  Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3958  Visited.add(ND);
3959  }
3960  }
3961  }
3962 
3963  // FIXME: C++ [temp.local]p8
3964  DeclContext *Entity = nullptr;
3965  if (S->getEntity()) {
3966  // Look into this scope's declaration context, along with any of its
3967  // parent lookup contexts (e.g., enclosing classes), up to the point
3968  // where we hit the context stored in the next outer scope.
3969  Entity = S->getEntity();
3970  DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3971 
3972  for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3973  Ctx = Ctx->getLookupParent()) {
3974  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3975  if (Method->isInstanceMethod()) {
3976  // For instance methods, look for ivars in the method's interface.
3977  LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3978  Result.getNameLoc(),
3980  if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3981  lookupInDeclContext(IFace, IvarResult,
3982  /*QualifiedNameLookup=*/false,
3983  /*InBaseClass=*/false);
3984  }
3985  }
3986 
3987  // We've already performed all of the name lookup that we need
3988  // to for Objective-C methods; the next context will be the
3989  // outer scope.
3990  break;
3991  }
3992 
3993  if (Ctx->isFunctionOrMethod())
3994  continue;
3995 
3996  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
3997  /*InBaseClass=*/false);
3998  }
3999  } else if (!S->getParent()) {
4000  // Look into the translation unit scope. We walk through the translation
4001  // unit's declaration context, because the Scope itself won't have all of
4002  // the declarations if we loaded a precompiled header.
4003  // FIXME: We would like the translation unit's Scope object to point to
4004  // the translation unit, so we don't need this special "if" branch.
4005  // However, doing so would force the normal C++ name-lookup code to look
4006  // into the translation unit decl when the IdentifierInfo chains would
4007  // suffice. Once we fix that problem (which is part of a more general
4008  // "don't look in DeclContexts unless we have to" optimization), we can
4009  // eliminate this.
4010  Entity = Result.getSema().Context.getTranslationUnitDecl();
4011  lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false,
4012  /*InBaseClass=*/false);
4013  }
4014 
4015  if (Entity) {
4016  // Lookup visible declarations in any namespaces found by using
4017  // directives.
4018  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
4019  lookupInDeclContext(
4020  const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
4021  /*QualifiedNameLookup=*/false,
4022  /*InBaseClass=*/false);
4023  }
4024 
4025  // Lookup names in the parent scope.
4026  ShadowContextRAII Shadow(Visited);
4027  lookupInScope(S->getParent(), Result, UDirs);
4028  }
4029 
4030 private:
4031  VisibleDeclsRecord Visited;
4032  VisibleDeclConsumer &Consumer;
4033  bool IncludeDependentBases;
4034  bool LoadExternal;
4035 };
4036 } // namespace
4037 
4039  VisibleDeclConsumer &Consumer,
4040  bool IncludeGlobalScope, bool LoadExternal) {
4041  LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
4042  LoadExternal);
4043  H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope);
4044 }
4045 
4047  VisibleDeclConsumer &Consumer,
4048  bool IncludeGlobalScope,
4049  bool IncludeDependentBases, bool LoadExternal) {
4050  LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
4051  H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope);
4052 }
4053 
4054 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
4055 /// If GnuLabelLoc is a valid source location, then this is a definition
4056 /// of an __label__ label name, otherwise it is a normal label definition
4057 /// or use.
4059  SourceLocation GnuLabelLoc) {
4060  // Do a lookup to see if we have a label with this name already.
4061  NamedDecl *Res = nullptr;
4062 
4063  if (GnuLabelLoc.isValid()) {
4064  // Local label definitions always shadow existing labels.
4065  Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
4066  Scope *S = CurScope;
4067  PushOnScopeChains(Res, S, true);
4068  return cast<LabelDecl>(Res);
4069  }
4070 
4071  // Not a GNU local label.
4072  Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
4073  // If we found a label, check to see if it is in the same context as us.
4074  // When in a Block, we don't want to reuse a label in an enclosing function.
4075  if (Res && Res->getDeclContext() != CurContext)
4076  Res = nullptr;
4077  if (!Res) {
4078  // If not forward referenced or defined already, create the backing decl.
4079  Res = LabelDecl::Create(Context, CurContext, Loc, II);
4080  Scope *S = CurScope->getFnParent();
4081  assert(S && "Not in a function?");
4082  PushOnScopeChains(Res, S, true);
4083  }
4084  return cast<LabelDecl>(Res);
4085 }
4086 
4087 //===----------------------------------------------------------------------===//
4088 // Typo correction
4089 //===----------------------------------------------------------------------===//
4090 
4092  TypoCorrection &Candidate) {
4093  Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
4094  return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
4095 }
4096 
4097 static void LookupPotentialTypoResult(Sema &SemaRef,
4098  LookupResult &Res,
4099  IdentifierInfo *Name,
4100  Scope *S, CXXScopeSpec *SS,
4102  bool EnteringContext,
4103  bool isObjCIvarLookup,
4104  bool FindHidden);
4105 
4106 /// Check whether the declarations found for a typo correction are
4107 /// visible. Set the correction's RequiresImport flag to true if none of the
4108 /// declarations are visible, false otherwise.
4109 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4110  TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4111 
4112  for (/**/; DI != DE; ++DI)
4113  if (!LookupResult::isVisible(SemaRef, *DI))
4114  break;
4115  // No filtering needed if all decls are visible.
4116  if (DI == DE) {
4117  TC.setRequiresImport(false);
4118  return;
4119  }
4120 
4121  llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4122  bool AnyVisibleDecls = !NewDecls.empty();
4123 
4124  for (/**/; DI != DE; ++DI) {
4125  if (LookupResult::isVisible(SemaRef, *DI)) {
4126  if (!AnyVisibleDecls) {
4127  // Found a visible decl, discard all hidden ones.
4128  AnyVisibleDecls = true;
4129  NewDecls.clear();
4130  }
4131  NewDecls.push_back(*DI);
4132  } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4133  NewDecls.push_back(*DI);
4134  }
4135 
4136  if (NewDecls.empty())
4137  TC = TypoCorrection();
4138  else {
4139  TC.setCorrectionDecls(NewDecls);
4140  TC.setRequiresImport(!AnyVisibleDecls);
4141  }
4142 }
4143 
4144 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
4145 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4146 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4148  NestedNameSpecifier *NNS,
4150  if (NestedNameSpecifier *Prefix = NNS->getPrefix())
4151  getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
4152  else
4153  Identifiers.clear();
4154 
4155  const IdentifierInfo *II = nullptr;
4156 
4157  switch (NNS->getKind()) {
4159  II = NNS->getAsIdentifier();
4160  break;
4161 
4163  if (NNS->getAsNamespace()->isAnonymousNamespace())
4164  return;
4165  II = NNS->getAsNamespace()->getIdentifier();
4166  break;
4167 
4169  II = NNS->getAsNamespaceAlias()->getIdentifier();
4170  break;
4171 
4174  II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
4175  break;
4176 
4179  return;
4180  }
4181 
4182  if (II)
4183  Identifiers.push_back(II);
4184 }
4185 
4187  DeclContext *Ctx, bool InBaseClass) {
4188  // Don't consider hidden names for typo correction.
4189  if (Hiding)
4190  return;
4191 
4192  // Only consider entities with identifiers for names, ignoring
4193  // special names (constructors, overloaded operators, selectors,
4194  // etc.).
4195  IdentifierInfo *Name = ND->getIdentifier();
4196  if (!Name)
4197  return;
4198 
4199  // Only consider visible declarations and declarations from modules with
4200  // names that exactly match.
4201  if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
4202  return;
4203 
4204  FoundName(Name->getName());
4205 }
4206 
4208  // Compute the edit distance between the typo and the name of this
4209  // entity, and add the identifier to the list of results.
4210  addName(Name, nullptr);
4211 }
4212 
4214  // Compute the edit distance between the typo and this keyword,
4215  // and add the keyword to the list of results.
4216  addName(Keyword, nullptr, nullptr, true);
4217 }
4218 
4219 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4220  NestedNameSpecifier *NNS, bool isKeyword) {
4221  // Use a simple length-based heuristic to determine the minimum possible
4222  // edit distance. If the minimum isn't good enough, bail out early.
4223  StringRef TypoStr = Typo->getName();
4224  unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
4225  if (MinED && TypoStr.size() / MinED < 3)
4226  return;
4227 
4228  // Compute an upper bound on the allowable edit distance, so that the
4229  // edit-distance algorithm can short-circuit.
4230  unsigned UpperBound = (TypoStr.size() + 2) / 3;
4231  unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
4232  if (ED > UpperBound) return;
4233 
4234  TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4235  if (isKeyword) TC.makeKeyword();
4236  TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
4237  addCorrection(TC);
4238 }
4239 
4240 static const unsigned MaxTypoDistanceResultSets = 5;
4241 
4243  StringRef TypoStr = Typo->getName();
4244  StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4245 
4246  // For very short typos, ignore potential corrections that have a different
4247  // base identifier from the typo or which have a normalized edit distance
4248  // longer than the typo itself.
4249  if (TypoStr.size() < 3 &&
4250  (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4251  return;
4252 
4253  // If the correction is resolved but is not viable, ignore it.
4254  if (Correction.isResolved()) {
4255  checkCorrectionVisibility(SemaRef, Correction);
4256  if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4257  return;
4258  }
4259 
4260  TypoResultList &CList =
4261  CorrectionResults[Correction.getEditDistance(false)][Name];
4262 
4263  if (!CList.empty() && !CList.back().isResolved())
4264  CList.pop_back();
4265  if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4266  std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4267  for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4268  RI != RIEnd; ++RI) {
4269  // If the Correction refers to a decl already in the result list,
4270  // replace the existing result if the string representation of Correction
4271  // comes before the current result alphabetically, then stop as there is
4272  // nothing more to be done to add Correction to the candidate set.
4273  if (RI->getCorrectionDecl() == NewND) {
4274  if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4275  *RI = Correction;
4276  return;
4277  }
4278  }
4279  }
4280  if (CList.empty() || Correction.isResolved())
4281  CList.push_back(Correction);
4282 
4283  while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4284  CorrectionResults.erase(std::prev(CorrectionResults.end()));
4285 }
4286 
4288  const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4289  SearchNamespaces = true;
4290 
4291  for (auto KNPair : KnownNamespaces)
4292  Namespaces.addNameSpecifier(KNPair.first);
4293 
4294  bool SSIsTemplate = false;
4295  if (NestedNameSpecifier *NNS =
4296  (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4297  if (const Type *T = NNS->getAsType())
4298  SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4299  }
4300  // Do not transform this into an iterator-based loop. The loop body can
4301  // trigger the creation of further types (through lazy deserialization) and
4302  // invalid iterators into this list.
4303  auto &Types = SemaRef.getASTContext().getTypes();
4304  for (unsigned I = 0; I != Types.size(); ++I) {
4305  const auto *TI = Types[I];
4306  if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4307  CD = CD->getCanonicalDecl();
4308  if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4309  !CD->isUnion() && CD->getIdentifier() &&
4310  (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4311  (CD->isBeingDefined() || CD->isCompleteDefinition()))
4312  Namespaces.addNameSpecifier(CD);
4313  }
4314  }
4315 }
4316 
4318  if (++CurrentTCIndex < ValidatedCorrections.size())
4319  return ValidatedCorrections[CurrentTCIndex];
4320 
4321  CurrentTCIndex = ValidatedCorrections.size();
4322  while (!CorrectionResults.empty()) {
4323  auto DI = CorrectionResults.begin();
4324  if (DI->second.empty()) {
4325  CorrectionResults.erase(DI);
4326  continue;
4327  }
4328 
4329  auto RI = DI->second.begin();
4330  if (RI->second.empty()) {
4331  DI->second.erase(RI);
4332  performQualifiedLookups();
4333  continue;
4334  }
4335 
4336  TypoCorrection TC = RI->second.pop_back_val();
4337  if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4338  ValidatedCorrections.push_back(TC);
4339  return ValidatedCorrections[CurrentTCIndex];
4340  }
4341  }
4342  return ValidatedCorrections[0]; // The empty correction.
4343 }
4344 
4345 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4346  IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4347  DeclContext *TempMemberContext = MemberContext;
4348  CXXScopeSpec *TempSS = SS.get();
4349 retry_lookup:
4350  LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4351  EnteringContext,
4352  CorrectionValidator->IsObjCIvarLookup,
4353  Name == Typo && !Candidate.WillReplaceSpecifier());
4354  switch (Result.getResultKind()) {
4358  if (TempSS) {
4359  // Immediately retry the lookup without the given CXXScopeSpec
4360  TempSS = nullptr;
4361  Candidate.WillReplaceSpecifier(true);
4362  goto retry_lookup;
4363  }
4364  if (TempMemberContext) {
4365  if (SS && !TempSS)
4366  TempSS = SS.get();
4367  TempMemberContext = nullptr;
4368  goto retry_lookup;
4369  }
4370  if (SearchNamespaces)
4371  QualifiedResults.push_back(Candidate);
4372  break;
4373 
4375  // We don't deal with ambiguities.
4376  break;
4377 
4378  case LookupResult::Found:
4380  // Store all of the Decls for overloaded symbols
4381  for (auto *TRD : Result)
4382  Candidate.addCorrectionDecl(TRD);
4383  checkCorrectionVisibility(SemaRef, Candidate);
4384  if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4385  if (SearchNamespaces)
4386  QualifiedResults.push_back(Candidate);
4387  break;
4388  }
4389  Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4390  return true;
4391  }
4392  return false;
4393 }
4394 
4395 void TypoCorrectionConsumer::performQualifiedLookups() {
4396  unsigned TypoLen = Typo->getName().size();
4397  for (const TypoCorrection &QR : QualifiedResults) {
4398  for (const auto &NSI : Namespaces) {
4399  DeclContext *Ctx = NSI.DeclCtx;
4400  const Type *NSType = NSI.NameSpecifier->getAsType();
4401 
4402  // If the current NestedNameSpecifier refers to a class and the
4403  // current correction candidate is the name of that class, then skip
4404  // it as it is unlikely a qualified version of the class' constructor
4405  // is an appropriate correction.
4406  if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4407  nullptr) {
4408  if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4409  continue;
4410  }
4411 
4412  TypoCorrection TC(QR);
4413  TC.ClearCorrectionDecls();
4414  TC.setCorrectionSpecifier(NSI.NameSpecifier);
4415  TC.setQualifierDistance(NSI.EditDistance);
4416  TC.setCallbackDistance(0); // Reset the callback distance
4417 
4418  // If the current correction candidate and namespace combination are
4419  // too far away from the original typo based on the normalized edit
4420  // distance, then skip performing a qualified name lookup.
4421  unsigned TmpED = TC.getEditDistance(true);
4422  if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4423  TypoLen / TmpED < 3)
4424  continue;
4425 
4426  Result.clear();
4427  Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4428  if (!SemaRef.LookupQualifiedName(Result, Ctx))
4429  continue;
4430 
4431  // Any corrections added below will be validated in subsequent
4432  // iterations of the main while() loop over the Consumer's contents.
4433  switch (Result.getResultKind()) {
4434  case LookupResult::Found:
4436  if (SS && SS->isValid()) {
4437  std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4438  std::string OldQualified;
4439  llvm::raw_string_ostream OldOStream(OldQualified);
4440  SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4441  OldOStream << Typo->getName();
4442  // If correction candidate would be an identical written qualified
4443  // identifier, then the existing CXXScopeSpec probably included a
4444  // typedef that didn't get accounted for properly.
4445  if (OldOStream.str() == NewQualified)
4446  break;
4447  }
4448  for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4449  TRD != TRDEnd; ++TRD) {
4450  if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4451  NSType ? NSType->getAsCXXRecordDecl()
4452  : nullptr,
4453  TRD.getPair()) == Sema::AR_accessible)
4454  TC.addCorrectionDecl(*TRD);
4455  }
4456  if (TC.isResolved()) {
4457  TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4458  addCorrection(TC);
4459  }
4460  break;
4461  }
4466  break;
4467  }
4468  }
4469  }
4470  QualifiedResults.clear();
4471 }
4472 
4473 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4474  ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4475  : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4476  if (NestedNameSpecifier *NNS =
4477  CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4478  llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4479  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4480 
4481  getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4482  }
4483  // Build the list of identifiers that would be used for an absolute
4484  // (from the global context) NestedNameSpecifier referring to the current
4485  // context.
4486  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4487  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4488  CurContextIdentifiers.push_back(ND->getIdentifier());
4489  }
4490 
4491  // Add the global context as a NestedNameSpecifier
4492  SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4494  DistanceMap[1].push_back(SI);
4495 }
4496 
4497 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4498  DeclContext *Start) -> DeclContextList {
4499  assert(Start && "Building a context chain from a null context");
4500  DeclContextList Chain;
4501  for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4502  DC = DC->getLookupParent()) {
4503  NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4504  if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4505  !(ND && ND->isAnonymousNamespace()))
4506  Chain.push_back(DC->getPrimaryContext());
4507  }
4508  return Chain;
4509 }
4510 
4511 unsigned
4512 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4513  DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4514  unsigned NumSpecifiers = 0;
4515  for (DeclContext *C : llvm::reverse(DeclChain)) {
4516  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4517  NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4518  ++NumSpecifiers;
4519  } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4520  NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4521  RD->getTypeForDecl());
4522  ++NumSpecifiers;
4523  }
4524  }
4525  return NumSpecifiers;
4526 }
4527 
4528 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4529  DeclContext *Ctx) {
4530  NestedNameSpecifier *NNS = nullptr;
4531  unsigned NumSpecifiers = 0;
4532  DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4533  DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4534 
4535  // Eliminate common elements from the two DeclContext chains.
4536  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4537  if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4538  break;
4539  NamespaceDeclChain.pop_back();
4540  }
4541 
4542  // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4543  NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4544 
4545  // Add an explicit leading '::' specifier if needed.
4546  if (NamespaceDeclChain.empty()) {
4547  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4548  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4549  NumSpecifiers =
4550  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4551  } else if (NamedDecl *ND =
4552  dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4553  IdentifierInfo *Name = ND->getIdentifier();
4554  bool SameNameSpecifier = false;
4555  if (std::find(CurNameSpecifierIdentifiers.begin(),
4556  CurNameSpecifierIdentifiers.end(),
4557  Name) != CurNameSpecifierIdentifiers.end()) {
4558  std::string NewNameSpecifier;
4559  llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4560  SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4561  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4562  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4563  SpecifierOStream.flush();
4564  SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4565  }
4566  if (SameNameSpecifier || llvm::find(CurContextIdentifiers, Name) !=
4567  CurContextIdentifiers.end()) {
4568  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4569  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4570  NumSpecifiers =
4571  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4572  }
4573  }
4574 
4575  // If the built NestedNameSpecifier would be replacing an existing
4576  // NestedNameSpecifier, use the number of component identifiers that
4577  // would need to be changed as the edit distance instead of the number
4578  // of components in the built NestedNameSpecifier.
4579  if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4580  SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4581  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4582  NumSpecifiers = llvm::ComputeEditDistance(
4583  llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4584  llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4585  }
4586 
4587  SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4588  DistanceMap[NumSpecifiers].push_back(SI);
4589 }
4590 
4591 /// Perform name lookup for a possible result for typo correction.
4592 static void LookupPotentialTypoResult(Sema &SemaRef,
4593  LookupResult &Res,
4594  IdentifierInfo *Name,
4595  Scope *S, CXXScopeSpec *SS,
4596  DeclContext *MemberContext,
4597  bool EnteringContext,
4598  bool isObjCIvarLookup,
4599  bool FindHidden) {
4600  Res.suppressDiagnostics();
4601  Res.clear();
4602  Res.setLookupName(Name);
4603  Res.setAllowHidden(FindHidden);
4604  if (MemberContext) {
4605  if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4606  if (isObjCIvarLookup) {
4607  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4608  Res.addDecl(Ivar);
4609  Res.resolveKind();
4610  return;
4611  }
4612  }
4613 
4614  if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4616  Res.addDecl(Prop);
4617  Res.resolveKind();
4618  return;
4619  }
4620  }
4621 
4622  SemaRef.LookupQualifiedName(Res, MemberContext);
4623  return;
4624  }
4625 
4626  SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4627  EnteringContext);
4628 
4629  // Fake ivar lookup; this should really be part of
4630  // LookupParsedName.
4631  if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4632  if (Method->isInstanceMethod() && Method->getClassInterface() &&
4633  (Res.empty() ||
4634  (Res.isSingleResult() &&
4636  if (ObjCIvarDecl *IV
4637  = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4638  Res.addDecl(IV);
4639  Res.resolveKind();
4640  }
4641  }
4642  }
4643 }
4644 
4645 /// Add keywords to the consumer as possible typo corrections.
4646 static void AddKeywordsToConsumer(Sema &SemaRef,
4647  TypoCorrectionConsumer &Consumer,
4649  bool AfterNestedNameSpecifier) {
4650  if (AfterNestedNameSpecifier) {
4651  // For 'X::', we know exactly which keywords can appear next.
4652  Consumer.addKeywordResult("template");
4653  if (CCC.WantExpressionKeywords)
4654  Consumer.addKeywordResult("operator");
4655  return;
4656  }
4657 
4658  if (CCC.WantObjCSuper)
4659  Consumer.addKeywordResult("super");
4660 
4661  if (CCC.WantTypeSpecifiers) {
4662  // Add type-specifier keywords to the set of results.
4663  static const char *const CTypeSpecs[] = {
4664  "char", "const", "double", "enum", "float", "int", "long", "short",
4665  "signed", "struct", "union", "unsigned", "void", "volatile",
4666  "_Complex", "_Imaginary",
4667  // storage-specifiers as well
4668  "extern", "inline", "static", "typedef"
4669  };
4670 
4671  const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4672  for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4673  Consumer.addKeywordResult(CTypeSpecs[I]);
4674 
4675  if (SemaRef.getLangOpts().C99)
4676  Consumer.addKeywordResult("restrict");
4677  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4678  Consumer.addKeywordResult("bool");
4679  else if (SemaRef.getLangOpts().C99)
4680  Consumer.addKeywordResult("_Bool");
4681 
4682  if (SemaRef.getLangOpts().CPlusPlus) {
4683  Consumer.addKeywordResult("class");
4684  Consumer.addKeywordResult("typename");
4685  Consumer.addKeywordResult("wchar_t");
4686 
4687  if (SemaRef.getLangOpts().CPlusPlus11) {
4688  Consumer.addKeywordResult("char16_t");
4689  Consumer.addKeywordResult("char32_t");
4690  Consumer.addKeywordResult("constexpr");
4691  Consumer.addKeywordResult("decltype");
4692  Consumer.addKeywordResult("thread_local");
4693  }
4694  }
4695 
4696  if (SemaRef.getLangOpts().GNUKeywords)
4697  Consumer.addKeywordResult("typeof");
4698  } else if (CCC.WantFunctionLikeCasts) {
4699  static const char *const CastableTypeSpecs[] = {
4700  "char", "double", "float", "int", "long", "short",
4701  "signed", "unsigned", "void"
4702  };
4703  for (auto *kw : CastableTypeSpecs)
4704  Consumer.addKeywordResult(kw);
4705  }
4706 
4707  if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4708  Consumer.addKeywordResult("const_cast");
4709  Consumer.addKeywordResult("dynamic_cast");
4710  Consumer.addKeywordResult("reinterpret_cast");
4711  Consumer.addKeywordResult("static_cast");
4712  }
4713 
4714  if (CCC.WantExpressionKeywords) {
4715  Consumer.addKeywordResult("sizeof");
4716  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4717  Consumer.addKeywordResult("false");
4718  Consumer.addKeywordResult("true");
4719  }
4720 
4721  if (SemaRef.getLangOpts().CPlusPlus) {
4722  static const char *const CXXExprs[] = {
4723  "delete", "new", "operator", "throw", "typeid"
4724  };
4725  const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4726  for (unsigned I = 0; I != NumCXXExprs; ++I)
4727  Consumer.addKeywordResult(CXXExprs[I]);
4728 
4729  if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4730  cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4731  Consumer.addKeywordResult("this");
4732 
4733  if (SemaRef.getLangOpts().CPlusPlus11) {
4734  Consumer.addKeywordResult("alignof");
4735  Consumer.addKeywordResult("nullptr");
4736  }
4737  }
4738 
4739  if (SemaRef.getLangOpts().C11) {
4740  // FIXME: We should not suggest _Alignof if the alignof macro
4741  // is present.
4742  Consumer.addKeywordResult("_Alignof");
4743  }
4744  }
4745 
4746  if (CCC.WantRemainingKeywords) {
4747  if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4748  // Statements.
4749  static const char *const CStmts[] = {
4750  "do", "else", "for", "goto", "if", "return", "switch", "while" };
4751  const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4752  for (unsigned I = 0; I != NumCStmts; ++I)
4753  Consumer.addKeywordResult(CStmts[I]);
4754 
4755  if (SemaRef.getLangOpts().CPlusPlus) {
4756  Consumer.addKeywordResult("catch");
4757  Consumer.addKeywordResult("try");
4758  }
4759 
4760  if (S && S->getBreakParent())
4761  Consumer.addKeywordResult("break");
4762 
4763  if (S && S->getContinueParent())
4764  Consumer.addKeywordResult("continue");
4765 
4766  if (SemaRef.getCurFunction() &&
4767  !SemaRef.getCurFunction()->SwitchStack.empty()) {
4768  Consumer.addKeywordResult("case");
4769  Consumer.addKeywordResult("default");
4770  }
4771  } else {
4772  if (SemaRef.getLangOpts().CPlusPlus) {
4773  Consumer.addKeywordResult("namespace");
4774  Consumer.addKeywordResult("template");
4775  }
4776 
4777  if (S && S->isClassScope()) {
4778  Consumer.addKeywordResult("explicit");
4779  Consumer.addKeywordResult("friend");
4780  Consumer.addKeywordResult("mutable");
4781  Consumer.addKeywordResult("private");
4782  Consumer.addKeywordResult("protected");
4783  Consumer.addKeywordResult("public");
4784  Consumer.addKeywordResult("virtual");
4785  }
4786  }
4787 
4788  if (SemaRef.getLangOpts().CPlusPlus) {
4789  Consumer.addKeywordResult("using");
4790 
4791  if (SemaRef.getLangOpts().CPlusPlus11)
4792  Consumer.addKeywordResult("static_assert");
4793  }
4794  }
4795 }
4796 
4797 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4798  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4800  DeclContext *MemberContext, bool EnteringContext,
4801  const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4802 
4803  if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4804  DisableTypoCorrection)
4805  return nullptr;
4806 
4807  // In Microsoft mode, don't perform typo correction in a template member
4808  // function dependent context because it interferes with the "lookup into
4809  // dependent bases of class templates" feature.
4810  if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4811  isa<CXXMethodDecl>(CurContext))
4812  return nullptr;
4813 
4814  // We only attempt to correct typos for identifiers.
4815  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4816  if (!Typo)
4817  return nullptr;
4818 
4819  // If the scope specifier itself was invalid, don't try to correct
4820  // typos.
4821  if (SS && SS->isInvalid())
4822  return nullptr;
4823 
4824  // Never try to correct typos during any kind of code synthesis.
4825  if (!CodeSynthesisContexts.empty())
4826  return nullptr;
4827 
4828  // Don't try to correct 'super'.
4829  if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4830  return nullptr;
4831 
4832  // Abort if typo correction already failed for this specific typo.
4833  IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4834  if (locs != TypoCorrectionFailures.end() &&
4835  locs->second.count(TypoName.getLoc()))
4836  return nullptr;
4837 
4838  // Don't try to correct the identifier "vector" when in AltiVec mode.
4839  // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4840  // remove this workaround.
4841  if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4842  return nullptr;
4843 
4844  // Provide a stop gap for files that are just seriously broken. Trying
4845  // to correct all typos can turn into a HUGE performance penalty, causing
4846  // some files to take minutes to get rejected by the parser.
4847  unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4848  if (Limit && TyposCorrected >= Limit)
4849  return nullptr;
4850  ++TyposCorrected;
4851 
4852  // If we're handling a missing symbol error, using modules, and the
4853  // special search all modules option is used, look for a missing import.
4854  if (ErrorRecovery && getLangOpts().Modules &&
4855  getLangOpts().ModulesSearchAll) {
4856  // The following has the side effect of loading the missing module.
4857  getModuleLoader().lookupMissingImports(Typo->getName(),
4858  TypoName.getBeginLoc());
4859  }
4860 
4861  // Extend the lifetime of the callback. We delayed this until here
4862  // to avoid allocations in the hot path (which is where no typo correction
4863  // occurs). Note that CorrectionCandidateCallback is polymorphic and
4864  // initially stack-allocated.
4865  std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
4866  auto Consumer = std::make_unique<TypoCorrectionConsumer>(
4867  *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext,
4868  EnteringContext);
4869 
4870  // Perform name lookup to find visible, similarly-named entities.
4871  bool IsUnqualifiedLookup = false;
4872  DeclContext *QualifiedDC = MemberContext;
4873  if (MemberContext) {
4874  LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4875 
4876  // Look in qualified interfaces.
4877  if (OPT) {
4878  for (auto *I : OPT->quals())
4879  LookupVisibleDecls(I, LookupKind, *Consumer);
4880  }
4881  } else if (SS && SS->isSet()) {
4882  QualifiedDC = computeDeclContext(*SS, EnteringContext);
4883  if (!QualifiedDC)
4884  return nullptr;
4885 
4886  LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4887  } else {
4888  IsUnqualifiedLookup = true;
4889  }
4890 
4891  // Determine whether we are going to search in the various namespaces for
4892  // corrections.
4893  bool SearchNamespaces
4894  = getLangOpts().CPlusPlus &&
4895  (IsUnqualifiedLookup || (SS && SS->isSet()));
4896 
4897  if (IsUnqualifiedLookup || SearchNamespaces) {
4898  // For unqualified lookup, look through all of the names that we have
4899  // seen in this translation unit.
4900  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4901  for (const auto &I : Context.Idents)
4902  Consumer->FoundName(I.getKey());
4903 
4904  // Walk through identifiers in external identifier sources.
4905  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4906  if (IdentifierInfoLookup *External
4907  = Context.Idents.getExternalIdentifierLookup()) {
4908  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4909  do {
4910  StringRef Name = Iter->Next();
4911  if (Name.empty())
4912  break;
4913 
4914  Consumer->FoundName(Name);
4915  } while (true);
4916  }
4917  }
4918 
4919  AddKeywordsToConsumer(*this, *Consumer, S,
4920  *Consumer->getCorrectionValidator(),
4921  SS && SS->isNotEmpty());
4922 
4923  // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4924  // to search those namespaces.
4925  if (SearchNamespaces) {
4926  // Load any externally-known namespaces.
4927  if (ExternalSource && !LoadedExternalKnownNamespaces) {
4928  SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4929  LoadedExternalKnownNamespaces = true;
4930  ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4931  for (auto *N : ExternalKnownNamespaces)
4932  KnownNamespaces[N] = true;
4933  }
4934 
4935  Consumer->addNamespaces(KnownNamespaces);
4936  }
4937 
4938  return Consumer;
4939 }
4940 
4941 /// Try to "correct" a typo in the source code by finding
4942 /// visible declarations whose names are similar to the name that was
4943 /// present in the source code.
4944 ///
4945 /// \param TypoName the \c DeclarationNameInfo structure that contains
4946 /// the name that was present in the source code along with its location.
4947 ///
4948 /// \param LookupKind the name-lookup criteria used to search for the name.
4949 ///
4950 /// \param S the scope in which name lookup occurs.
4951 ///
4952 /// \param SS the nested-name-specifier that precedes the name we're
4953 /// looking for, if present.
4954 ///
4955 /// \param CCC A CorrectionCandidateCallback object that provides further
4956 /// validation of typo correction candidates. It also provides flags for
4957 /// determining the set of keywords permitted.
4958 ///
4959 /// \param MemberContext if non-NULL, the context in which to look for
4960 /// a member access expression.
4961 ///
4962 /// \param EnteringContext whether we're entering the context described by
4963 /// the nested-name-specifier SS.
4964 ///
4965 /// \param OPT when non-NULL, the search for visible declarations will
4966 /// also walk the protocols in the qualified interfaces of \p OPT.
4967 ///
4968 /// \returns a \c TypoCorrection containing the corrected name if the typo
4969 /// along with information such as the \c NamedDecl where the corrected name
4970 /// was declared, and any additional \c NestedNameSpecifier needed to access
4971 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4973  Sema::LookupNameKind LookupKind,
4974  Scope *S, CXXScopeSpec *SS,
4976  CorrectTypoKind Mode,
4977  DeclContext *MemberContext,
4978  bool EnteringContext,
4979  const ObjCObjectPointerType *OPT,
4980  bool RecordFailure) {
4981  // Always let the ExternalSource have the first chance at correction, even
4982  // if we would otherwise have given up.
4983  if (ExternalSource) {
4984  if (TypoCorrection Correction =
4985  ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC,
4986  MemberContext, EnteringContext, OPT))
4987  return Correction;
4988  }
4989 
4990  // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4991  // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4992  // some instances of CTC_Unknown, while WantRemainingKeywords is true
4993  // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4994  bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
4995 
4996  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4997  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
4998  MemberContext, EnteringContext,
4999  OPT, Mode == CTK_ErrorRecovery);
5000 
5001  if (!Consumer)
5002  return TypoCorrection();
5003 
5004  // If we haven't found anything, we're done.
5005  if (Consumer->empty())
5006  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5007 
5008  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5009  // is not more that about a third of the length of the typo's identifier.
5010  unsigned ED = Consumer->getBestEditDistance(true);
5011  unsigned TypoLen = Typo->getName().size();
5012  if (ED > 0 && TypoLen / ED < 3)
5013  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5014 
5015  TypoCorrection BestTC = Consumer->getNextCorrection();
5016  TypoCorrection SecondBestTC = Consumer->getNextCorrection();
5017  if (!BestTC)
5018  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5019 
5020  ED = BestTC.getEditDistance();
5021 
5022  if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
5023  // If this was an unqualified lookup and we believe the callback
5024  // object wouldn't have filtered out possible corrections, note
5025  // that no correction was found.
5026  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5027  }
5028 
5029  // If only a single name remains, return that result.
5030  if (!SecondBestTC ||
5031  SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
5032  const TypoCorrection &Result = BestTC;
5033 
5034  // Don't correct to a keyword that's the same as the typo; the keyword
5035  // wasn't actually in scope.
5036  if (ED == 0 && Result.isKeyword())
5037  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5038 
5039  TypoCorrection TC = Result;
5040  TC.setCorrectionRange(SS, TypoName);
5041  checkCorrectionVisibility(*this, TC);
5042  return TC;
5043  } else if (SecondBestTC && ObjCMessageReceiver) {
5044  // Prefer 'super' when we're completing in a message-receiver
5045  // context.
5046 
5047  if (BestTC.getCorrection().getAsString() != "super") {
5048  if (SecondBestTC.getCorrection().getAsString() == "super")
5049  BestTC = SecondBestTC;
5050  else if ((*Consumer)["super"].front().isKeyword())
5051  BestTC = (*Consumer)["super"].front();
5052  }
5053  // Don't correct to a keyword that's the same as the typo; the keyword
5054  // wasn't actually in scope.
5055  if (BestTC.getEditDistance() == 0 ||
5056  BestTC.getCorrection().getAsString() != "super")
5057  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5058 
5059  BestTC.setCorrectionRange(SS, TypoName);
5060  return BestTC;
5061  }
5062 
5063  // Record the failure's location if needed and return an empty correction. If
5064  // this was an unqualified lookup and we believe the callback object did not
5065  // filter out possible corrections, also cache the failure for the typo.
5066  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
5067 }
5068 
5069 /// Try to "correct" a typo in the source code by finding
5070 /// visible declarations whose names are similar to the name that was
5071 /// present in the source code.
5072 ///
5073 /// \param TypoName the \c DeclarationNameInfo structure that contains
5074 /// the name that was present in the source code along with its location.
5075 ///
5076 /// \param LookupKind the name-lookup criteria used to search for the name.
5077 ///
5078 /// \param S the scope in which name lookup occurs.
5079 ///
5080 /// \param SS the nested-name-specifier that precedes the name we're
5081 /// looking for, if present.
5082 ///
5083 /// \param CCC A CorrectionCandidateCallback object that provides further
5084 /// validation of typo correction candidates. It also provides flags for
5085 /// determining the set of keywords permitted.
5086 ///
5087 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
5088 /// diagnostics when the actual typo correction is attempted.
5089 ///
5090 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
5091 /// Expr from a typo correction candidate.
5092 ///
5093 /// \param MemberContext if non-NULL, the context in which to look for
5094 /// a member access expression.
5095 ///
5096 /// \param EnteringContext whether we're entering the context described by
5097 /// the nested-name-specifier SS.
5098 ///
5099 /// \param OPT when non-NULL, the search for visible declarations will
5100 /// also walk the protocols in the qualified interfaces of \p OPT.
5101 ///
5102 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
5103 /// Expr representing the result of performing typo correction, or nullptr if
5104 /// typo correction is not possible. If nullptr is returned, no diagnostics will
5105 /// be emitted and it is the responsibility of the caller to emit any that are
5106 /// needed.
5108  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
5111  DeclContext *MemberContext, bool EnteringContext,
5112  const ObjCObjectPointerType *OPT) {
5113  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
5114  MemberContext, EnteringContext,
5115  OPT, Mode == CTK_ErrorRecovery);
5116 
5117  // Give the external sema source a chance to correct the typo.
5118  TypoCorrection ExternalTypo;
5119  if (ExternalSource && Consumer) {
5120  ExternalTypo = ExternalSource->CorrectTypo(
5121  TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
5122  MemberContext, EnteringContext, OPT);
5123  if (ExternalTypo)
5124  Consumer->addCorrection(ExternalTypo);
5125  }
5126 
5127  if (!Consumer || Consumer->empty())
5128  return nullptr;
5129 
5130  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5131  // is not more that about a third of the length of the typo's identifier.
5132  unsigned ED = Consumer->getBestEditDistance(true);
5133  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5134  if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
5135  return nullptr;
5136 
5137  ExprEvalContexts.back().NumTypos++;
5138  return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
5139 }
5140 
5142  if (!CDecl) return;
5143 
5144  if (isKeyword())
5145  CorrectionDecls.clear();
5146 
5147  CorrectionDecls.push_back(CDecl);
5148 
5149  if (!CorrectionName)
5150  CorrectionName = CDecl->getDeclName();
5151 }
5152 
5153 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
5154  if (CorrectionNameSpec) {
5155  std::string tmpBuffer;
5156  llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5157  CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
5158  PrefixOStream << CorrectionName;
5159  return PrefixOStream.str();
5160  }
5161 
5162  return CorrectionName.getAsString();
5163 }
5164 
5166  const TypoCorrection &candidate) {
5167  if (!candidate.isResolved())
5168  return true;
5169 
5170  if (candidate.isKeyword())
5171  return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
5172  WantRemainingKeywords || WantObjCSuper;
5173 
5174  bool HasNonType = false;
5175  bool HasStaticMethod = false;
5176  bool HasNonStaticMethod = false;
5177  for (Decl *D : candidate) {
5178  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
5179  D = FTD->getTemplatedDecl();
5180  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
5181  if (Method->isStatic())
5182  HasStaticMethod = true;
5183  else
5184  HasNonStaticMethod = true;
5185  }
5186  if (!isa<TypeDecl>(D))
5187  HasNonType = true;
5188  }
5189 
5190  if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5191  !candidate.getCorrectionSpecifier())
5192  return false;
5193 
5194  return WantTypeSpecifiers || HasNonType;
5195 }
5196 
5198  bool HasExplicitTemplateArgs,
5199  MemberExpr *ME)
5200  : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5201  CurContext(SemaRef.CurContext), MemberFn(ME) {
5202  WantTypeSpecifiers = false;
5203  WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5204  !HasExplicitTemplateArgs && NumArgs == 1;
5205  WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5206  WantRemainingKeywords = false;
5207 }
5208 
5210  if (!candidate.getCorrectionDecl())
5211  return candidate.isKeyword();
5212 
5213  for (auto *C : candidate) {
5214  FunctionDecl *FD = nullptr;
5215  NamedDecl *ND = C->getUnderlyingDecl();
5216  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
5217  FD = FTD->getTemplatedDecl();
5218  if (!HasExplicitTemplateArgs && !FD) {
5219  if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
5220  // If the Decl is neither a function nor a template function,
5221  // determine if it is a pointer or reference to a function. If so,
5222  // check against the number of arguments expected for the pointee.
5223  QualType ValType = cast<ValueDecl>(ND)->getType();
5224  if (ValType.isNull())
5225  continue;
5226  if (ValType->isAnyPointerType() || ValType->isReferenceType())
5227  ValType = ValType->getPointeeType();
5228  if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5229  if (FPT->getNumParams() == NumArgs)
5230  return true;
5231  }
5232  }
5233 
5234  // A typo for a function-style cast can look like a function call in C++.
5235  if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr
5236  : isa<TypeDecl>(ND)) &&
5237  CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5238  // Only a class or class template can take two or more arguments.
5239  return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND);
5240 
5241  // Skip the current candidate if it is not a FunctionDecl or does not accept
5242  // the current number of arguments.
5243  if (!FD || !(FD->getNumParams() >= NumArgs &&
5244  FD->getMinRequiredArguments() <= NumArgs))
5245  continue;
5246 
5247  // If the current candidate is a non-static C++ method, skip the candidate
5248  // unless the method being corrected--or the current DeclContext, if the
5249  // function being corrected is not a method--is a method in the same class
5250  // or a descendent class of the candidate's parent class.
5251  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
5252  if (MemberFn || !MD->isStatic()) {
5253  CXXMethodDecl *CurMD =
5254  MemberFn
5255  ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
5256  : dyn_cast_or_null<CXXMethodDecl>(CurContext);
5257  CXXRecordDecl *CurRD =
5258  CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5259  CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5260  if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5261  continue;
5262  }
5263  }
5264  return true;
5265  }
5266  return false;
5267 }
5268 
5269 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5270  const PartialDiagnostic &TypoDiag,
5271  bool ErrorRecovery) {
5272  diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5273  ErrorRecovery);
5274 }
5275 
5276 /// Find which declaration we should import to provide the definition of
5277 /// the given declaration.
5279  if (VarDecl *VD = dyn_cast<VarDecl>(D))
5280  return VD->getDefinition();
5281  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5282  return FD->getDefinition();
5283  if (TagDecl *TD = dyn_cast<TagDecl>(D))
5284  return TD->getDefinition();
5285  // The first definition for this ObjCInterfaceDecl might be in the TU
5286  // and not associated with any module. Use the one we know to be complete
5287  // and have just seen in a module.
5288  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5289  return ID;
5290  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5291  return PD->getDefinition();
5292  if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5293  if (NamedDecl *TTD = TD->getTemplatedDecl())
5294  return getDefinitionToImport(TTD);
5295  return nullptr;
5296 }
5297 
5299  MissingImportKind MIK, bool Recover) {
5300  // Suggest importing a module providing the definition of this entity, if
5301  // possible.
5302  NamedDecl *Def = getDefinitionToImport(Decl);
5303  if (!Def)
5304  Def = Decl;
5305 
5306  Module *Owner = getOwningModule(Def);
5307  assert(Owner && "definition of hidden declaration is not in a module");
5308 
5309  llvm::SmallVector<Module*, 8> OwningModules;
5310  OwningModules.push_back(Owner);
5311  auto Merged = Context.getModulesWithMergedDefinition(Def);
5312  OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5313 
5314  diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
5315  Recover);
5316 }
5317 
5318 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5319 /// suggesting the addition of a #include of the specified file.
5321  const FileEntry *E,
5322  llvm::StringRef IncludingFile) {
5323  bool IsSystem = false;
5325  E, IncludingFile, &IsSystem);
5326  return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5327 }
5328 
5330  SourceLocation DeclLoc,
5331  ArrayRef<Module *> Modules,
5332  MissingImportKind MIK, bool Recover) {
5333  assert(!Modules.empty());
5334 
5335  auto NotePrevious = [&] {
5336  unsigned DiagID;
5337  switch (MIK) {
5338  case MissingImportKind::Declaration:
5339  DiagID = diag::note_previous_declaration;
5340  break;
5341  case MissingImportKind::Definition:
5342  DiagID = diag::note_previous_definition;
5343  break;
5344  case MissingImportKind::DefaultArgument:
5345  DiagID = diag::note_default_argument_declared_here;
5346  break;
5347  case MissingImportKind::ExplicitSpecialization:
5348  DiagID = diag::note_explicit_specialization_declared_here;
5349  break;
5350  case MissingImportKind::PartialSpecialization:
5351  DiagID = diag::note_partial_specialization_declared_here;
5352  break;
5353  }
5354  Diag(DeclLoc, DiagID);
5355  };
5356 
5357  // Weed out duplicates from module list.
5358  llvm::SmallVector<Module*, 8> UniqueModules;
5359  llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5360  for (auto *M : Modules) {
5361  if (M->Kind == Module::GlobalModuleFragment)
5362  continue;
5363  if (UniqueModuleSet.insert(M).second)
5364  UniqueModules.push_back(M);
5365  }
5366 
5367  llvm::StringRef IncludingFile;
5368  if (const FileEntry *FE =
5369  SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc)))
5370  IncludingFile = FE->tryGetRealPathName();
5371 
5372  if (UniqueModules.empty()) {
5373  // All candidates were global module fragments. Try to suggest a #include.
5374  const FileEntry *E =
5375  PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, Modules[0], DeclLoc);
5376  // FIXME: Find a smart place to suggest inserting a #include, and add
5377  // a FixItHint there.
5378  Diag(UseLoc, diag::err_module_unimported_use_global_module_fragment)
5379  << (int)MIK << Decl << !!E
5380  << (E ? getIncludeStringForHeader(PP, E, IncludingFile) : "");
5381  // Produce a "previous" note if it will point to a header rather than some
5382  // random global module fragment.
5383  // FIXME: Suppress the note backtrace even under
5384  // -fdiagnostics-show-note-include-stack.
5385  if (E)
5386  NotePrevious();
5387  if (Recover)
5388  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5389  return;
5390  }
5391 
5392  Modules = UniqueModules;
5393 
5394  if (Modules.size() > 1) {
5395  std::string ModuleList;
5396  unsigned N = 0;
5397  for (Module *M : Modules) {
5398  ModuleList += "\n ";
5399  if (++N == 5 && N != Modules.size()) {
5400  ModuleList += "[...]";
5401  break;
5402  }
5403  ModuleList += M->getFullModuleName();
5404  }
5405 
5406  Diag(UseLoc, diag::err_module_unimported_use_multiple)
5407  << (int)MIK << Decl << ModuleList;
5408  } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5409  UseLoc, Modules[0], DeclLoc)) {
5410  // The right way to make the declaration visible is to include a header;
5411  // suggest doing so.
5412  //
5413  // FIXME: Find a smart place to suggest inserting a #include, and add
5414  // a FixItHint there.
5415  Diag(UseLoc, diag::err_module_unimported_use_header)
5416  << (int)MIK << Decl << Modules[0]->getFullModuleName()
5417  << getIncludeStringForHeader(PP, E, IncludingFile);
5418  } else {
5419  // FIXME: Add a FixItHint that imports the corresponding module.
5420  Diag(UseLoc, diag::err_module_unimported_use)
5421  << (int)MIK << Decl << Modules[0]->getFullModuleName();
5422  }
5423 
5424  NotePrevious();
5425 
5426  // Try to recover by implicitly importing this module.
5427  if (Recover)
5428  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5429 }
5430 
5431 /// Diagnose a successfully-corrected typo. Separated from the correction
5432 /// itself to allow external validation of the result, etc.
5433 ///
5434 /// \param Correction The result of performing typo correction.
5435 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5436 /// string added to it (and usually also a fixit).
5437 /// \param PrevNote A note to use when indicating the location of the entity to
5438 /// which we are correcting. Will have the correction string added to it.
5439 /// \param ErrorRecovery If \c true (the default), the caller is going to
5440 /// recover from the typo as if the corrected string had been typed.
5441 /// In this case, \c PDiag must be an error, and we will attach a fixit
5442 /// to it.
5443 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5444  const PartialDiagnostic &TypoDiag,
5445  const PartialDiagnostic &PrevNote,
5446  bool ErrorRecovery) {
5447  std::string CorrectedStr = Correction.getAsString(getLangOpts());
5448  std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5450  Correction.getCorrectionRange(), CorrectedStr);
5451 
5452  // Maybe we're just missing a module import.
5453  if (Correction.requiresImport()) {
5454  NamedDecl *Decl = Correction.getFoundDecl();
5455  assert(Decl && "import required but no declaration to import");
5456 
5457  diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5458  MissingImportKind::Declaration, ErrorRecovery);
5459  return;
5460  }
5461 
5462  Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5463  << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5464 
5465  NamedDecl *ChosenDecl =
5466  Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5467  if (PrevNote.getDiagID() && ChosenDecl)
5468  Diag(ChosenDecl->getLocation(), PrevNote)
5469  << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5470 
5471  // Add any extra diagnostics.
5472  for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5473  Diag(Correction.getCorrectionRange().getBegin(), PD);
5474 }
5475 
5476 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5478  TypoRecoveryCallback TRC) {
5479  assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5480  auto TE = new (Context) TypoExpr(Context.DependentTy);
5481  auto &State = DelayedTypos[TE];
5482  State.Consumer = std::move(TCC);
5483  State.DiagHandler = std::move(TDG);
5484  State.RecoveryHandler = std::move(TRC);
5485  if (TE)
5486  TypoExprs.push_back(TE);
5487  return TE;
5488 }
5489 
5490 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5491  auto Entry = DelayedTypos.find(TE);
5492  assert(Entry != DelayedTypos.end() &&
5493  "Failed to get the state for a TypoExpr!");
5494  return Entry->second;
5495 }
5496 
5498  DelayedTypos.erase(TE);
5499 }
5500 
5502  DeclarationNameInfo Name(II, IILoc);
5503  LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5504  R.suppressDiagnostics();
5505  R.setHideTags(false);
5506  LookupName(R, S);
5507  R.dump();
5508 }
SourceLocation getLoc() const
getLoc - Returns the main location of the declaration name.
Defines the clang::ASTContext interface.
void setScopeInfo(unsigned scopeDepth, unsigned parameterIndex)
Definition: Decl.h:1633
Name lookup results in an ambiguity because multiple definitions of entity that meet the lookup crite...
Definition: Lookup.h:118
void setImplicit(bool I=true)
Definition: DeclBase.h:559
Represents a function declaration or definition.
Definition: Decl.h:1784
FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs, MemberExpr *ME=nullptr)
Name lookup found a set of overloaded functions that met the criteria.
Definition: Lookup.h:63
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
static FunctionDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation NLoc, DeclarationName N, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInlineSpecified=false, bool hasWrittenPrototype=true, ConstexprSpecKind ConstexprKind=CSK_unspecified)
Definition: Decl.h:1931
bool isForRedeclaration() const
True if this lookup is just looking for an existing declaration.
Definition: Lookup.h:258
SourceRange getCorrectionRange() const
bool isPredefinedLibFunction(unsigned ID) const
Determines whether this builtin is a predefined libc/libm function, such as "malloc", where we know the signature a priori.
Definition: Builtins.h:140
void setOrigin(CXXRecordDecl *Rec)
CXXMethodDecl * getMethod() const
Definition: Sema.h:1129
no exception specification
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2585
A (possibly-)qualified type.
Definition: Type.h:643
Simple class containing the result of Sema::CorrectTypo.
base_class_range bases()
Definition: DeclCXX.h:589
ValueDecl * getMemberDecl() const
Retrieve the member declaration to which this expression refers.
Definition: Expr.h:2894
bool hasVisibleDeclarationSlow(const NamedDecl *D, llvm::SmallVectorImpl< Module *> *Modules)
CorrectTypoKind
Definition: Sema.h:3547
virtual unsigned RankCandidate(const TypoCorrection &candidate)
Method used by Sema::CorrectTypo to assign an "edit distance" rank to a candidate (where a lower valu...
Template argument deduction was successful.
Definition: Sema.h:7395
Defines the clang::FileManager interface and associated types.
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3315
DeclarationName getCXXConstructorName(CanQualType Ty)
Returns the name of a C++ constructor for the given Type.
void setLookupName(DeclarationName Name)
Sets the name to look up.
Definition: Lookup.h:248
bool LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation=false)
Perform unqualified name lookup starting from a given scope.
AmbiguityKind getAmbiguityKind() const
Definition: Lookup.h:326
Look up the name of an Objective-C protocol.
Definition: Sema.h:3349
Filter makeFilter()
Create a filter for this result set.
Definition: Lookup.h:682
CXXMethodDecl * LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals)
Look up the moving assignment operator for the given class.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3393
Provides information about an attempted template argument deduction, whose success or failure was des...
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:557
void addConst()
Add the const type qualifier to this QualType.
Definition: Type.h:812
Microsoft&#39;s &#39;__super&#39; specifier, stored as a CXXRecordDecl* of the class it appeared in...
void ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class)
Force the declaration of any implicitly-declared members of this class.
Definition: SemaLookup.cpp:892
The template argument is an expression, and we&#39;ve not resolved it to one of the other forms yet...
Definition: TemplateBase.h:86
unsigned size() const
Retrieve the number of template arguments in this template argument list.
Definition: DeclTemplate.h:284
bool isSingleTagDecl() const
Asks if the result is a single tag decl.
Definition: Lookup.h:530
void erase()
Erase the last element returned from this iterator.
Definition: Lookup.h:654
ConstructorInfo getConstructorInfo(NamedDecl *ND)
Definition: Overload.h:1103
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
__DEVICE__ long long abs(long long __n)
bool isModuleVisible(const Module *M, bool ModulePrivate=false)
NestedNameSpecifier * getPrefix() const
Return the prefix of this nested name specifier.
SmallVectorImpl< NamedDecl * >::iterator decl_iterator
Name lookup results in an ambiguity because multiple nonstatic entities that meet the lookup criteria...
Definition: Lookup.h:103
Defines the C++ template declaration subclasses.
bool LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, bool AllowBuiltinCreation=false, bool EnteringContext=false)
Performs name lookup for a name that was parsed in the source code, and may contain a C++ scope speci...
StringRef P
Classification Classify(ASTContext &Ctx) const
Classify - Classify this expression according to the C++11 expression taxonomy.
Definition: Expr.h:386
OverloadedOperatorKind getCXXOverloadedOperator() const
If this name is the name of an overloadable operator in C++ (e.g., operator+), retrieve the kind of o...
bool isTemplateParamScope() const
isTemplateParamScope - Return true if this scope is a C++ template parameter scope.
Definition: Scope.h:378
void swap(CXXBasePaths &Other)
Swap this data structure&#39;s contents with another CXXBasePaths object.
SmallVector< CodeSynthesisContext, 16 > CodeSynthesisContexts
List of active code synthesis contexts.
Definition: Sema.h:7750
static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D, llvm::SmallVectorImpl< Module *> *Modules, Filter F)
Decl * getPreviousDecl()
Retrieve the previous declaration that declares the same entity as this declaration, or NULL if there is no previous declaration.
Definition: DeclBase.h:960
NamedDecl * getDecl() const
The base class of the type hierarchy.
Definition: Type.h:1436
SourceLocation getBeginLoc() const
getBeginLoc - Retrieve the location of the first token.
MissingImportKind
Kinds of missing import.
Definition: Sema.h:2389
bool isDerivedFrom(const CXXRecordDecl *Base) const
Determine whether this class is derived from the class Base.
The template argument is a declaration that was provided for a pointer, reference, or pointer to member non-type template parameter.
Definition: TemplateBase.h:63
Represent a C++ namespace.
Definition: Decl.h:522
RedeclarationKind
Specifies whether (or how) name lookup is being performed for a redeclaration (vs.
Definition: Sema.h:3362
Ambiguous candidates found.
Definition: Overload.h:59
NamedDecl * getParam(unsigned Idx)
Definition: DeclTemplate.h:132
decl_iterator begin()
AccessSpecifier
A C++ access specifier (public, private, protected), plus the special value "none" which means differ...
Definition: Specifiers.h:113
const NestedNameSpecifier * Specifier
Look up of a name that precedes the &#39;::&#39; scope resolution operator in C++.
Definition: Sema.h:3331
void makeKeyword()
Mark this TypoCorrection as being a keyword.
bool needsImplicitMoveAssignment() const
Determine whether this class should get an implicit move assignment operator or if any existing speci...
Definition: DeclCXX.h:927
Scope * getContinueParent()
getContinueParent - Return the closest scope that a continue statement would be affected by...
Definition: Scope.h:242
void setCorrectionSpecifier(NestedNameSpecifier *NNS)
bool hasNext() const
Definition: Lookup.h:639
Represents a path from a specific derived class (which is not represented as part of the path) to a p...
LiteralOperatorLookupResult
The possible outcomes of name lookup for a literal operator.
Definition: Sema.h:3387
unsigned getIdentifierNamespace() const
Definition: DeclBase.h:799
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2365
LLVM_ATTRIBUTE_REINITIALIZES void clear()
Clears out any current state.
Definition: Lookup.h:554
bool isCompleteDefinition() const
Return true if this decl has its body fully specified.
Definition: Decl.h:3238
lookups_range noload_lookups(bool PreserveInternalState) const
Definition: DeclLookups.h:89
Look up a namespace name within a C++ using directive or namespace alias definition, ignoring non-namespace names (C++ [basic.lookup.udir]p1).
Definition: Sema.h:3335
CXXMethodDecl * DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl)
Declare the implicit move assignment operator for the given class.
Consumes visible declarations found when searching for all visible names within a given scope or cont...
Definition: Lookup.h:765
An identifier, stored as an IdentifierInfo*.
CXXConstructorDecl * LookupMovingConstructor(CXXRecordDecl *Class, unsigned Quals)
Look up the moving constructor for the given class.
std::list< CXXBasePath >::iterator paths_iterator
DeclContext::lookup_result Decls
The set of declarations found inside this base class subobject.
Represents a variable declaration or definition.
Definition: Decl.h:827
CXXMethodDecl * LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals)
Look up the copying assignment operator for the given class.
static NestedNameSpecifier * Create(const ASTContext &Context, NestedNameSpecifier *Prefix, IdentifierInfo *II)
Builds a specifier combining a prefix and an identifier.
DeclarationName getLookupName() const
Gets the name to look up.
Definition: Lookup.h:243
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6858
PrintingPolicy getPrintingPolicy() const
Retrieve a suitable printing policy for diagnostics.
Definition: Sema.h:2422
static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last)
Determine whether the given set of member declarations contains only static members, nested types, and enumerators.
bool isInObjcMethodScope() const
isInObjcMethodScope - Return true if this scope is, or is contained in, an Objective-C method body...
Definition: Scope.h:356
Represents an empty template argument, e.g., one that has not been deduced.
Definition: TemplateBase.h:56
Extra information about a function prototype.
Definition: Type.h:3805
static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class)
Determine whether we can declare a special member function within the class at this point...
Definition: SemaLookup.cpp:883
bool needsImplicitCopyAssignment() const
Determine whether this class needs an implicit copy assignment operator to be lazily declared...
Definition: DeclCXX.h:878
void setNotFoundInCurrentInstantiation()
Note that while no result was found in the current instantiation, there were dependent base classes t...
Definition: Lookup.h:452
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:138
NamedDecl * getUnderlyingDecl()
Looks through UsingDecls and ObjCCompatibleAliasDecls for the underlying named decl.
Definition: Decl.h:439
bool isAmbiguous() const
Definition: Lookup.h:301
static bool FindOMPReductionMember(const CXXBaseSpecifier *Specifier, CXXBasePath &Path, DeclarationName Name)
Base-class lookup callback that determines whether there exists an OpenMP declare reduction member wi...
A namespace, stored as a NamespaceDecl*.
bool isInvalidDecl() const
Definition: DeclBase.h:553
Stores a list of template parameters for a TemplateDecl and its derived classes.
Definition: DeclTemplate.h:67
Describes how types, statements, expressions, and declarations should be printed. ...
Definition: PrettyPrinter.h:37
SpecifierKind getKind() const
Determine what kind of nested name specifier is stored.
Look up an ordinary name that is going to be redeclared as a name with linkage.
Definition: Sema.h:3344
Represents a parameter to a function.
Definition: Decl.h:1600
Defines the clang::Expr interface and subclasses for C++ expressions.
void addKeywordResult(StringRef Keyword)
static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR, IdentifierInfo *II, const unsigned FctIndex, const unsigned Len)
When trying to resolve a function name, if isOpenCLBuiltin() returns a non-null <Index, Len> pair, then the name is referencing an OpenCL builtin function.
Definition: SemaLookup.cpp:751
void setMethod(CXXMethodDecl *MD)
Definition: Sema.h:1130
ModuleKind Kind
The kind of this module.
Definition: Module.h:88
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Types, declared with &#39;struct foo&#39;, typedefs, etc.
Definition: DeclBase.h:132
Represents a struct/union/class.
Definition: Decl.h:3662
bool LookupInSuper(LookupResult &R, CXXRecordDecl *Class)
Perform qualified name lookup into all base classes of the given class.
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:297
bool Encloses(const DeclContext *DC) const
Determine whether this declaration context encloses the declaration context DC.
Definition: DeclBase.cpp:1159
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3806
Represents a class template specialization, which refers to a class template with a given set of temp...
One of these records is kept for each identifier that is lexed.
Name lookup results in an ambiguity; use getAmbiguityKind to figure out what kind of ambiguity we hav...
Definition: Lookup.h:73
bool isStr(const char(&Str)[StrLen]) const
Return true if this is the identifier for the specified string.
std::string getQuoted(const LangOptions &LO) const
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:160
DeclarationName getCorrection() const
Gets the DeclarationName of the typo correction.
The results of name lookup within a DeclContext.
Definition: DeclBase.h:1195
LineState State
The template argument is an integral value stored in an llvm::APSInt that was provided for an integra...
Definition: TemplateBase.h:71
TemplateDecl * getAsTemplateDecl() const
Retrieve the underlying template declaration that this template name refers to, if known...
Base class for callback objects used by Sema::CorrectTypo to check the validity of a potential typo c...
sema::BlockScopeInfo * getCurBlock()
Retrieve the current block, if any.
Definition: Sema.cpp:1800
void setAmbiguousBaseSubobjectTypes(CXXBasePaths &P)
Make these results show that the name was found in base classes of different types.
Definition: SemaLookup.cpp:650
NameKind getNameKind() const
Determine what kind of name this is.
const Type * getAsType() const
Retrieve the type stored in this nested name specifier.
void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx, bool InBaseClass) override
Invoked each time Sema::LookupVisibleDecls() finds a declaration visible from the current scope or co...
This declaration is a friend function.
Definition: DeclBase.h:154
void setVisibleDespiteOwningModule()
Set that this declaration is globally visible, even if it came from a module that is not visible...
Definition: DeclBase.h:780
const DeclarationNameInfo & getLookupNameInfo() const
Gets the name info to look up.
Definition: Lookup.h:233
conversion_iterator conversion_end() const
Definition: DeclCXX.h:1040
bool isReferenceType() const
Definition: Type.h:6403
The iterator over UnresolvedSets.
Definition: UnresolvedSet.h:31
void addCorrectionDecl(NamedDecl *CDecl)
Add the given NamedDecl to the list of NamedDecls that are the declarations associated with the Decla...
bool isDefinedOutsideFunctionOrMethod() const
isDefinedOutsideFunctionOrMethod - This predicate returns true if this scoped decl is defined outside...
Definition: DeclBase.h:855
int Category
Definition: Format.cpp:1810
static std::string getIncludeStringForHeader(Preprocessor &PP, const FileEntry *E, llvm::StringRef IncludingFile)
Get a "quoted.h" or <angled.h> include path to use in a diagnostic suggesting the addition of a #incl...
bool Equals(const DeclContext *DC) const
Determine whether this declaration context is equivalent to the declaration context DC...
Definition: DeclBase.h:1903
bool isExternallyDeclarable() const
Determine whether this declaration can be redeclared in a different translation unit.
Definition: Decl.h:393
LookupResultKind getResultKind() const
Definition: Lookup.h:321
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:49
Scope * getBreakParent()
getBreakParent - Return the closest scope that a break statement would be affected by...
Definition: Scope.h:252
No entity found met the criteria within the current instantiation,, but there were dependent base cla...
Definition: Lookup.h:55
bool requiresImport() const
Returns whether this typo correction is correcting to a declaration that was declared in a module tha...
Describes a module or submodule.
Definition: Module.h:64