clang  9.0.0svn
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 /// When trying to resolve a function name, if the isOpenCLBuiltin function
677 /// defined in "OpenCLBuiltins.inc" returns a non-null <Index, Len>, then the
678 /// identifier is referencing an OpenCL builtin function. Thus, all its
679 /// prototypes are added to the LookUpResult.
680 ///
681 /// \param S The Sema instance
682 /// \param LR The LookupResult instance
683 /// \param II The identifier being resolved
684 /// \param Index The list of prototypes starts at Index in OpenCLBuiltins[]
685 /// \param Len The list of prototypes has Len elements
687  IdentifierInfo *II, unsigned Index,
688  unsigned Len) {
689 
690  for (unsigned i = 0; i < Len; ++i) {
691  const OpenCLBuiltinDecl &Decl = OpenCLBuiltins[Index - 1 + i];
692  ASTContext &Context = S.Context;
693 
694  // Ignore this BIF if the version is incorrect.
695  if (Context.getLangOpts().OpenCLVersion < Decl.Version)
696  continue;
697 
699  PI.Variadic = false;
700 
701  // Defined in "OpenCLBuiltins.inc"
702  QualType RT = OCL2Qual(Context, OpenCLSignature[Decl.ArgTableIndex]);
703 
704  SmallVector<QualType, 5> ArgTypes;
705  for (unsigned I = 1; I < Decl.NumArgs; I++) {
706  QualType Ty = OCL2Qual(Context, OpenCLSignature[Decl.ArgTableIndex + I]);
707  ArgTypes.push_back(Ty);
708  }
709 
710  QualType R = Context.getFunctionType(RT, ArgTypes, PI);
711  SourceLocation Loc = LR.getNameLoc();
712 
713  // TODO: This part is taken from Sema::LazilyCreateBuiltin,
714  // maybe refactor it.
716  FunctionDecl *New = FunctionDecl::Create(Context, Parent, Loc, Loc, II, R,
717  /*TInfo=*/nullptr, SC_Extern,
718  false, R->isFunctionProtoType());
719  New->setImplicit();
720 
721  // Create Decl objects for each parameter, adding them to the
722  // FunctionDecl.
723  if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) {
725  for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
726  ParmVarDecl *Parm =
727  ParmVarDecl::Create(Context, New, SourceLocation(),
728  SourceLocation(), nullptr, FT->getParamType(i),
729  /*TInfo=*/nullptr, SC_None, nullptr);
730  Parm->setScopeInfo(0, i);
731  Params.push_back(Parm);
732  }
733  New->setParams(Params);
734  }
735 
736  New->addAttr(OverloadableAttr::CreateImplicit(Context));
737 
738  if (strlen(Decl.Extension))
739  S.setOpenCLExtensionForDecl(New, Decl.Extension);
740 
741  LR.addDecl(New);
742  }
743 
744  // If we added overloads, need to resolve the lookup result.
745  if (Len > 1)
746  LR.resolveKind();
747 }
748 
749 /// Lookup a builtin function, when name lookup would otherwise
750 /// fail.
751 static bool LookupBuiltin(Sema &S, LookupResult &R) {
752  Sema::LookupNameKind NameKind = R.getLookupKind();
753 
754  // If we didn't find a use of this identifier, and if the identifier
755  // corresponds to a compiler builtin, create the decl object for the builtin
756  // now, injecting it into translation unit scope, and return it.
757  if (NameKind == Sema::LookupOrdinaryName ||
760  if (II) {
761  if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
762  if (II == S.getASTContext().getMakeIntegerSeqName()) {
764  return true;
765  } else if (II == S.getASTContext().getTypePackElementName()) {
767  return true;
768  }
769  }
770 
771  // Check if this is an OpenCL Builtin, and if so, insert its overloads.
772  if (S.getLangOpts().OpenCL && S.getLangOpts().DeclareOpenCLBuiltins) {
773  auto Index = isOpenCLBuiltin(II->getName());
774  if (Index.first) {
775  InsertOCLBuiltinDeclarations(S, R, II, Index.first, Index.second);
776  return true;
777  }
778  }
779 
780  // If this is a builtin on this (or all) targets, create the decl.
781  if (unsigned BuiltinID = II->getBuiltinID()) {
782  // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
783  // library functions like 'malloc'. Instead, we'll just error.
784  if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
786  return false;
787 
789  BuiltinID, S.TUScope,
790  R.isForRedeclaration(),
791  R.getNameLoc())) {
792  R.addDecl(D);
793  return true;
794  }
795  }
796  }
797  }
798 
799  return false;
800 }
801 
802 /// Determine whether we can declare a special member function within
803 /// the class at this point.
805  // We need to have a definition for the class.
806  if (!Class->getDefinition() || Class->isDependentContext())
807  return false;
808 
809  // We can't be in the middle of defining the class.
810  return !Class->isBeingDefined();
811 }
812 
815  return;
816 
817  // If the default constructor has not yet been declared, do so now.
818  if (Class->needsImplicitDefaultConstructor())
819  DeclareImplicitDefaultConstructor(Class);
820 
821  // If the copy constructor has not yet been declared, do so now.
822  if (Class->needsImplicitCopyConstructor())
823  DeclareImplicitCopyConstructor(Class);
824 
825  // If the copy assignment operator has not yet been declared, do so now.
826  if (Class->needsImplicitCopyAssignment())
827  DeclareImplicitCopyAssignment(Class);
828 
829  if (getLangOpts().CPlusPlus11) {
830  // If the move constructor has not yet been declared, do so now.
831  if (Class->needsImplicitMoveConstructor())
832  DeclareImplicitMoveConstructor(Class);
833 
834  // If the move assignment operator has not yet been declared, do so now.
835  if (Class->needsImplicitMoveAssignment())
836  DeclareImplicitMoveAssignment(Class);
837  }
838 
839  // If the destructor has not yet been declared, do so now.
840  if (Class->needsImplicitDestructor())
841  DeclareImplicitDestructor(Class);
842 }
843 
844 /// Determine whether this is the name of an implicitly-declared
845 /// special member function.
847  switch (Name.getNameKind()) {
850  return true;
851 
853  return Name.getCXXOverloadedOperator() == OO_Equal;
854 
855  default:
856  break;
857  }
858 
859  return false;
860 }
861 
862 /// If there are any implicit member functions with the given name
863 /// that need to be declared in the given declaration context, do so.
865  DeclarationName Name,
866  SourceLocation Loc,
867  const DeclContext *DC) {
868  if (!DC)
869  return;
870 
871  switch (Name.getNameKind()) {
873  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
874  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
875  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
876  if (Record->needsImplicitDefaultConstructor())
878  if (Record->needsImplicitCopyConstructor())
880  if (S.getLangOpts().CPlusPlus11 &&
881  Record->needsImplicitMoveConstructor())
883  }
884  break;
885 
887  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
888  if (Record->getDefinition() && Record->needsImplicitDestructor() &&
890  S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
891  break;
892 
894  if (Name.getCXXOverloadedOperator() != OO_Equal)
895  break;
896 
897  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
898  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
899  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
900  if (Record->needsImplicitCopyAssignment())
902  if (S.getLangOpts().CPlusPlus11 &&
903  Record->needsImplicitMoveAssignment())
905  }
906  }
907  break;
908 
911  break;
912 
913  default:
914  break;
915  }
916 }
917 
918 // Adds all qualifying matches for a name within a decl context to the
919 // given lookup result. Returns true if any matches were found.
920 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
921  bool Found = false;
922 
923  // Lazily declare C++ special member functions.
924  if (S.getLangOpts().CPlusPlus)
926  DC);
927 
928  // Perform lookup into this declaration context.
930  for (NamedDecl *D : DR) {
931  if ((D = R.getAcceptableDecl(D))) {
932  R.addDecl(D);
933  Found = true;
934  }
935  }
936 
937  if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
938  return true;
939 
940  if (R.getLookupName().getNameKind()
943  !isa<CXXRecordDecl>(DC))
944  return Found;
945 
946  // C++ [temp.mem]p6:
947  // A specialization of a conversion function template is not found by
948  // name lookup. Instead, any conversion function templates visible in the
949  // context of the use are considered. [...]
950  const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
951  if (!Record->isCompleteDefinition())
952  return Found;
953 
954  // For conversion operators, 'operator auto' should only match
955  // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
956  // as a candidate for template substitution.
957  auto *ContainedDeducedType =
959  if (R.getLookupName().getNameKind() ==
961  ContainedDeducedType && ContainedDeducedType->isUndeducedType())
962  return Found;
963 
965  UEnd = Record->conversion_end(); U != UEnd; ++U) {
966  FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
967  if (!ConvTemplate)
968  continue;
969 
970  // When we're performing lookup for the purposes of redeclaration, just
971  // add the conversion function template. When we deduce template
972  // arguments for specializations, we'll end up unifying the return
973  // type of the new declaration with the type of the function template.
974  if (R.isForRedeclaration()) {
975  R.addDecl(ConvTemplate);
976  Found = true;
977  continue;
978  }
979 
980  // C++ [temp.mem]p6:
981  // [...] For each such operator, if argument deduction succeeds
982  // (14.9.2.3), the resulting specialization is used as if found by
983  // name lookup.
984  //
985  // When referencing a conversion function for any purpose other than
986  // a redeclaration (such that we'll be building an expression with the
987  // result), perform template argument deduction and place the
988  // specialization into the result set. We do this to avoid forcing all
989  // callers to perform special deduction for conversion functions.
991  FunctionDecl *Specialization = nullptr;
992 
993  const FunctionProtoType *ConvProto
994  = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
995  assert(ConvProto && "Nonsensical conversion function template type");
996 
997  // Compute the type of the function that we would expect the conversion
998  // function to have, if it were to match the name given.
999  // FIXME: Calling convention!
1001  EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
1002  EPI.ExceptionSpec = EST_None;
1005  None, EPI);
1006 
1007  // Perform template argument deduction against the type that we would
1008  // expect the function to have.
1009  if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
1010  Specialization, Info)
1011  == Sema::TDK_Success) {
1012  R.addDecl(Specialization);
1013  Found = true;
1014  }
1015  }
1016 
1017  return Found;
1018 }
1019 
1020 // Performs C++ unqualified lookup into the given file context.
1021 static bool
1023  DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
1024 
1025  assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
1026 
1027  // Perform direct name lookup into the LookupCtx.
1028  bool Found = LookupDirect(S, R, NS);
1029 
1030  // Perform direct name lookup into the namespaces nominated by the
1031  // using directives whose common ancestor is this namespace.
1032  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
1033  if (LookupDirect(S, R, UUE.getNominatedNamespace()))
1034  Found = true;
1035 
1036  R.resolveKind();
1037 
1038  return Found;
1039 }
1040 
1042  if (DeclContext *Ctx = S->getEntity())
1043  return Ctx->isFileContext();
1044  return false;
1045 }
1046 
1047 // Find the next outer declaration context from this scope. This
1048 // routine actually returns the semantic outer context, which may
1049 // differ from the lexical context (encoded directly in the Scope
1050 // stack) when we are parsing a member of a class template. In this
1051 // case, the second element of the pair will be true, to indicate that
1052 // name lookup should continue searching in this semantic context when
1053 // it leaves the current template parameter scope.
1054 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
1055  DeclContext *DC = S->getEntity();
1056  DeclContext *Lexical = nullptr;
1057  for (Scope *OuterS = S->getParent(); OuterS;
1058  OuterS = OuterS->getParent()) {
1059  if (OuterS->getEntity()) {
1060  Lexical = OuterS->getEntity();
1061  break;
1062  }
1063  }
1064 
1065  // C++ [temp.local]p8:
1066  // In the definition of a member of a class template that appears
1067  // outside of the namespace containing the class template
1068  // definition, the name of a template-parameter hides the name of
1069  // a member of this namespace.
1070  //
1071  // Example:
1072  //
1073  // namespace N {
1074  // class C { };
1075  //
1076  // template<class T> class B {
1077  // void f(T);
1078  // };
1079  // }
1080  //
1081  // template<class C> void N::B<C>::f(C) {
1082  // C b; // C is the template parameter, not N::C
1083  // }
1084  //
1085  // In this example, the lexical context we return is the
1086  // TranslationUnit, while the semantic context is the namespace N.
1087  if (!Lexical || !DC || !S->getParent() ||
1089  return std::make_pair(Lexical, false);
1090 
1091  // Find the outermost template parameter scope.
1092  // For the example, this is the scope for the template parameters of
1093  // template<class C>.
1094  Scope *OutermostTemplateScope = S->getParent();
1095  while (OutermostTemplateScope->getParent() &&
1096  OutermostTemplateScope->getParent()->isTemplateParamScope())
1097  OutermostTemplateScope = OutermostTemplateScope->getParent();
1098 
1099  // Find the namespace context in which the original scope occurs. In
1100  // the example, this is namespace N.
1101  DeclContext *Semantic = DC;
1102  while (!Semantic->isFileContext())
1103  Semantic = Semantic->getParent();
1104 
1105  // Find the declaration context just outside of the template
1106  // parameter scope. This is the context in which the template is
1107  // being lexically declaration (a namespace context). In the
1108  // example, this is the global scope.
1109  if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1110  Lexical->Encloses(Semantic))
1111  return std::make_pair(Semantic, true);
1112 
1113  return std::make_pair(Lexical, false);
1114 }
1115 
1116 namespace {
1117 /// An RAII object to specify that we want to find block scope extern
1118 /// declarations.
1119 struct FindLocalExternScope {
1120  FindLocalExternScope(LookupResult &R)
1121  : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1125  }
1126  void restore() {
1127  R.setFindLocalExtern(OldFindLocalExtern);
1128  }
1129  ~FindLocalExternScope() {
1130  restore();
1131  }
1132  LookupResult &R;
1133  bool OldFindLocalExtern;
1134 };
1135 } // end anonymous namespace
1136 
1137 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1138  assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1139 
1140  DeclarationName Name = R.getLookupName();
1141  Sema::LookupNameKind NameKind = R.getLookupKind();
1142 
1143  // If this is the name of an implicitly-declared special member function,
1144  // go through the scope stack to implicitly declare
1146  for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1147  if (DeclContext *DC = PreS->getEntity())
1148  DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1149  }
1150 
1151  // Implicitly declare member functions with the name we're looking for, if in
1152  // fact we are in a scope where it matters.
1153 
1154  Scope *Initial = S;
1156  I = IdResolver.begin(Name),
1157  IEnd = IdResolver.end();
1158 
1159  // First we lookup local scope.
1160  // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1161  // ...During unqualified name lookup (3.4.1), the names appear as if
1162  // they were declared in the nearest enclosing namespace which contains
1163  // both the using-directive and the nominated namespace.
1164  // [Note: in this context, "contains" means "contains directly or
1165  // indirectly".
1166  //
1167  // For example:
1168  // namespace A { int i; }
1169  // void foo() {
1170  // int i;
1171  // {
1172  // using namespace A;
1173  // ++i; // finds local 'i', A::i appears at global scope
1174  // }
1175  // }
1176  //
1177  UnqualUsingDirectiveSet UDirs(*this);
1178  bool VisitedUsingDirectives = false;
1179  bool LeftStartingScope = false;
1180  DeclContext *OutsideOfTemplateParamDC = nullptr;
1181 
1182  // When performing a scope lookup, we want to find local extern decls.
1183  FindLocalExternScope FindLocals(R);
1184 
1185  for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1186  DeclContext *Ctx = S->getEntity();
1187  bool SearchNamespaceScope = true;
1188  // Check whether the IdResolver has anything in this scope.
1189  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1190  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1191  if (NameKind == LookupRedeclarationWithLinkage &&
1192  !(*I)->isTemplateParameter()) {
1193  // If it's a template parameter, we still find it, so we can diagnose
1194  // the invalid redeclaration.
1195 
1196  // Determine whether this (or a previous) declaration is
1197  // out-of-scope.
1198  if (!LeftStartingScope && !Initial->isDeclScope(*I))
1199  LeftStartingScope = true;
1200 
1201  // If we found something outside of our starting scope that
1202  // does not have linkage, skip it.
1203  if (LeftStartingScope && !((*I)->hasLinkage())) {
1204  R.setShadowed();
1205  continue;
1206  }
1207  } else {
1208  // We found something in this scope, we should not look at the
1209  // namespace scope
1210  SearchNamespaceScope = false;
1211  }
1212  R.addDecl(ND);
1213  }
1214  }
1215  if (!SearchNamespaceScope) {
1216  R.resolveKind();
1217  if (S->isClassScope())
1218  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1219  R.setNamingClass(Record);
1220  return true;
1221  }
1222 
1223  if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1224  // C++11 [class.friend]p11:
1225  // If a friend declaration appears in a local class and the name
1226  // specified is an unqualified name, a prior declaration is
1227  // looked up without considering scopes that are outside the
1228  // innermost enclosing non-class scope.
1229  return false;
1230  }
1231 
1232  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1233  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1234  // We've just searched the last template parameter scope and
1235  // found nothing, so look into the contexts between the
1236  // lexical and semantic declaration contexts returned by
1237  // findOuterContext(). This implements the name lookup behavior
1238  // of C++ [temp.local]p8.
1239  Ctx = OutsideOfTemplateParamDC;
1240  OutsideOfTemplateParamDC = nullptr;
1241  }
1242 
1243  if (Ctx) {
1244  DeclContext *OuterCtx;
1245  bool SearchAfterTemplateScope;
1246  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1247  if (SearchAfterTemplateScope)
1248  OutsideOfTemplateParamDC = OuterCtx;
1249 
1250  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1251  // We do not directly look into transparent contexts, since
1252  // those entities will be found in the nearest enclosing
1253  // non-transparent context.
1254  if (Ctx->isTransparentContext())
1255  continue;
1256 
1257  // We do not look directly into function or method contexts,
1258  // since all of the local variables and parameters of the
1259  // function/method are present within the Scope.
1260  if (Ctx->isFunctionOrMethod()) {
1261  // If we have an Objective-C instance method, look for ivars
1262  // in the corresponding interface.
1263  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1264  if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1265  if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1266  ObjCInterfaceDecl *ClassDeclared;
1267  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1268  Name.getAsIdentifierInfo(),
1269  ClassDeclared)) {
1270  if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1271  R.addDecl(ND);
1272  R.resolveKind();
1273  return true;
1274  }
1275  }
1276  }
1277  }
1278 
1279  continue;
1280  }
1281 
1282  // If this is a file context, we need to perform unqualified name
1283  // lookup considering using directives.
1284  if (Ctx->isFileContext()) {
1285  // If we haven't handled using directives yet, do so now.
1286  if (!VisitedUsingDirectives) {
1287  // Add using directives from this context up to the top level.
1288  for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1289  if (UCtx->isTransparentContext())
1290  continue;
1291 
1292  UDirs.visit(UCtx, UCtx);
1293  }
1294 
1295  // Find the innermost file scope, so we can add using directives
1296  // from local scopes.
1297  Scope *InnermostFileScope = S;
1298  while (InnermostFileScope &&
1299  !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1300  InnermostFileScope = InnermostFileScope->getParent();
1301  UDirs.visitScopeChain(Initial, InnermostFileScope);
1302 
1303  UDirs.done();
1304 
1305  VisitedUsingDirectives = true;
1306  }
1307 
1308  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1309  R.resolveKind();
1310  return true;
1311  }
1312 
1313  continue;
1314  }
1315 
1316  // Perform qualified name lookup into this context.
1317  // FIXME: In some cases, we know that every name that could be found by
1318  // this qualified name lookup will also be on the identifier chain. For
1319  // example, inside a class without any base classes, we never need to
1320  // perform qualified lookup because all of the members are on top of the
1321  // identifier chain.
1322  if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1323  return true;
1324  }
1325  }
1326  }
1327 
1328  // Stop if we ran out of scopes.
1329  // FIXME: This really, really shouldn't be happening.
1330  if (!S) return false;
1331 
1332  // If we are looking for members, no need to look into global/namespace scope.
1333  if (NameKind == LookupMemberName)
1334  return false;
1335 
1336  // Collect UsingDirectiveDecls in all scopes, and recursively all
1337  // nominated namespaces by those using-directives.
1338  //
1339  // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1340  // don't build it for each lookup!
1341  if (!VisitedUsingDirectives) {
1342  UDirs.visitScopeChain(Initial, S);
1343  UDirs.done();
1344  }
1345 
1346  // If we're not performing redeclaration lookup, do not look for local
1347  // extern declarations outside of a function scope.
1348  if (!R.isForRedeclaration())
1349  FindLocals.restore();
1350 
1351  // Lookup namespace scope, and global scope.
1352  // Unqualified name lookup in C++ requires looking into scopes
1353  // that aren't strictly lexical, and therefore we walk through the
1354  // context as well as walking through the scopes.
1355  for (; S; S = S->getParent()) {
1356  // Check whether the IdResolver has anything in this scope.
1357  bool Found = false;
1358  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1359  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1360  // We found something. Look for anything else in our scope
1361  // with this same name and in an acceptable identifier
1362  // namespace, so that we can construct an overload set if we
1363  // need to.
1364  Found = true;
1365  R.addDecl(ND);
1366  }
1367  }
1368 
1369  if (Found && S->isTemplateParamScope()) {
1370  R.resolveKind();
1371  return true;
1372  }
1373 
1374  DeclContext *Ctx = S->getEntity();
1375  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1376  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1377  // We've just searched the last template parameter scope and
1378  // found nothing, so look into the contexts between the
1379  // lexical and semantic declaration contexts returned by
1380  // findOuterContext(). This implements the name lookup behavior
1381  // of C++ [temp.local]p8.
1382  Ctx = OutsideOfTemplateParamDC;
1383  OutsideOfTemplateParamDC = nullptr;
1384  }
1385 
1386  if (Ctx) {
1387  DeclContext *OuterCtx;
1388  bool SearchAfterTemplateScope;
1389  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1390  if (SearchAfterTemplateScope)
1391  OutsideOfTemplateParamDC = OuterCtx;
1392 
1393  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1394  // We do not directly look into transparent contexts, since
1395  // those entities will be found in the nearest enclosing
1396  // non-transparent context.
1397  if (Ctx->isTransparentContext())
1398  continue;
1399 
1400  // If we have a context, and it's not a context stashed in the
1401  // template parameter scope for an out-of-line definition, also
1402  // look into that context.
1403  if (!(Found && S->isTemplateParamScope())) {
1404  assert(Ctx->isFileContext() &&
1405  "We should have been looking only at file context here already.");
1406 
1407  // Look into context considering using-directives.
1408  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1409  Found = true;
1410  }
1411 
1412  if (Found) {
1413  R.resolveKind();
1414  return true;
1415  }
1416 
1417  if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1418  return false;
1419  }
1420  }
1421 
1422  if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1423  return false;
1424  }
1425 
1426  return !R.empty();
1427 }
1428 
1430  if (auto *M = getCurrentModule())
1431  Context.mergeDefinitionIntoModule(ND, M);
1432  else
1433  // We're not building a module; just make the definition visible.
1435 
1436  // If ND is a template declaration, make the template parameters
1437  // visible too. They're not (necessarily) within a mergeable DeclContext.
1438  if (auto *TD = dyn_cast<TemplateDecl>(ND))
1439  for (auto *Param : *TD->getTemplateParameters())
1440  makeMergedDefinitionVisible(Param);
1441 }
1442 
1443 /// Find the module in which the given declaration was defined.
1444 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1445  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1446  // If this function was instantiated from a template, the defining module is
1447  // the module containing the pattern.
1448  if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1449  Entity = Pattern;
1450  } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1451  if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1452  Entity = Pattern;
1453  } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1454  if (auto *Pattern = ED->getTemplateInstantiationPattern())
1455  Entity = Pattern;
1456  } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1457  if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1458  Entity = Pattern;
1459  }
1460 
1461  // Walk up to the containing context. That might also have been instantiated
1462  // from a template.
1463  DeclContext *Context = Entity->getLexicalDeclContext();
1464  if (Context->isFileContext())
1465  return S.getOwningModule(Entity);
1466  return getDefiningModule(S, cast<Decl>(Context));
1467 }
1468 
1470  unsigned N = CodeSynthesisContexts.size();
1471  for (unsigned I = CodeSynthesisContextLookupModules.size();
1472  I != N; ++I) {
1473  Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1474  if (M && !LookupModulesCache.insert(M).second)
1475  M = nullptr;
1476  CodeSynthesisContextLookupModules.push_back(M);
1477  }
1478  return LookupModulesCache;
1479 }
1480 
1481 /// Determine whether the module M is part of the current module from the
1482 /// perspective of a module-private visibility check.
1483 static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts) {
1484  // If M is the global module fragment of a module that we've not yet finished
1485  // parsing, then it must be part of the current module.
1486  return M->getTopLevelModuleName() == LangOpts.CurrentModule ||
1487  (M->Kind == Module::GlobalModuleFragment && !M->Parent);
1488 }
1489 
1491  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1492  if (isModuleVisible(Merged))
1493  return true;
1494  return false;
1495 }
1496 
1498  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1499  if (isInCurrentModule(Merged, getLangOpts()))
1500  return true;
1501  return false;
1502 }
1503 
1504 template<typename ParmDecl>
1505 static bool
1506 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1508  if (!D->hasDefaultArgument())
1509  return false;
1510 
1511  while (D) {
1512  auto &DefaultArg = D->getDefaultArgStorage();
1513  if (!DefaultArg.isInherited() && S.isVisible(D))
1514  return true;
1515 
1516  if (!DefaultArg.isInherited() && Modules) {
1517  auto *NonConstD = const_cast<ParmDecl*>(D);
1518  Modules->push_back(S.getOwningModule(NonConstD));
1519  }
1520 
1521  // If there was a previous default argument, maybe its parameter is visible.
1522  D = DefaultArg.getInheritedFrom();
1523  }
1524  return false;
1525 }
1526 
1529  if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1530  return ::hasVisibleDefaultArgument(*this, P, Modules);
1531  if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1532  return ::hasVisibleDefaultArgument(*this, P, Modules);
1533  return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1534  Modules);
1535 }
1536 
1537 template<typename Filter>
1538 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1540  Filter F) {
1541  bool HasFilteredRedecls = false;
1542 
1543  for (auto *Redecl : D->redecls()) {
1544  auto *R = cast<NamedDecl>(Redecl);
1545  if (!F(R))
1546  continue;
1547 
1548  if (S.isVisible(R))
1549  return true;
1550 
1551  HasFilteredRedecls = true;
1552 
1553  if (Modules)
1554  Modules->push_back(R->getOwningModule());
1555  }
1556 
1557  // Only return false if there is at least one redecl that is not filtered out.
1558  if (HasFilteredRedecls)
1559  return false;
1560 
1561  return true;
1562 }
1563 
1565  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1566  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1567  if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1568  return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1569  if (auto *FD = dyn_cast<FunctionDecl>(D))
1570  return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1571  if (auto *VD = dyn_cast<VarDecl>(D))
1572  return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1573  llvm_unreachable("unknown explicit specialization kind");
1574  });
1575 }
1576 
1578  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1579  assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1580  "not a member specialization");
1581  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1582  // If the specialization is declared at namespace scope, then it's a member
1583  // specialization declaration. If it's lexically inside the class
1584  // definition then it was instantiated.
1585  //
1586  // FIXME: This is a hack. There should be a better way to determine this.
1587  // FIXME: What about MS-style explicit specializations declared within a
1588  // class definition?
1589  return D->getLexicalDeclContext()->isFileContext();
1590  });
1591 }
1592 
1593 /// Determine whether a declaration is visible to name lookup.
1594 ///
1595 /// This routine determines whether the declaration D is visible in the current
1596 /// lookup context, taking into account the current template instantiation
1597 /// stack. During template instantiation, a declaration is visible if it is
1598 /// visible from a module containing any entity on the template instantiation
1599 /// path (by instantiating a template, you allow it to see the declarations that
1600 /// your module can see, including those later on in your module).
1601 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1602  assert(D->isHidden() && "should not call this: not in slow case");
1603 
1604  Module *DeclModule = SemaRef.getOwningModule(D);
1605  assert(DeclModule && "hidden decl has no owning module");
1606 
1607  // If the owning module is visible, the decl is visible.
1608  if (SemaRef.isModuleVisible(DeclModule, D->isModulePrivate()))
1609  return true;
1610 
1611  // Determine whether a decl context is a file context for the purpose of
1612  // visibility. This looks through some (export and linkage spec) transparent
1613  // contexts, but not others (enums).
1614  auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1615  return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1616  isa<ExportDecl>(DC);
1617  };
1618 
1619  // If this declaration is not at namespace scope
1620  // then it is visible if its lexical parent has a visible definition.
1622  if (DC && !IsEffectivelyFileContext(DC)) {
1623  // For a parameter, check whether our current template declaration's
1624  // lexical context is visible, not whether there's some other visible
1625  // definition of it, because parameters aren't "within" the definition.
1626  //
1627  // In C++ we need to check for a visible definition due to ODR merging,
1628  // and in C we must not because each declaration of a function gets its own
1629  // set of declarations for tags in prototype scope.
1630  bool VisibleWithinParent;
1631  if (D->isTemplateParameter()) {
1632  bool SearchDefinitions = true;
1633  if (const auto *DCD = dyn_cast<Decl>(DC)) {
1634  if (const auto *TD = DCD->getDescribedTemplate()) {
1635  TemplateParameterList *TPL = TD->getTemplateParameters();
1636  auto Index = getDepthAndIndex(D).second;
1637  SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D;
1638  }
1639  }
1640  if (SearchDefinitions)
1641  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1642  else
1643  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1644  } else if (isa<ParmVarDecl>(D) ||
1645  (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1646  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1647  else if (D->isModulePrivate()) {
1648  // A module-private declaration is only visible if an enclosing lexical
1649  // parent was merged with another definition in the current module.
1650  VisibleWithinParent = false;
1651  do {
1652  if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1653  VisibleWithinParent = true;
1654  break;
1655  }
1656  DC = DC->getLexicalParent();
1657  } while (!IsEffectivelyFileContext(DC));
1658  } else {
1659  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1660  }
1661 
1662  if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1663  // FIXME: Do something better in this case.
1664  !SemaRef.getLangOpts().ModulesLocalVisibility) {
1665  // Cache the fact that this declaration is implicitly visible because
1666  // its parent has a visible definition.
1668  }
1669  return VisibleWithinParent;
1670  }
1671 
1672  return false;
1673 }
1674 
1675 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1676  // The module might be ordinarily visible. For a module-private query, that
1677  // means it is part of the current module. For any other query, that means it
1678  // is in our visible module set.
1679  if (ModulePrivate) {
1680  if (isInCurrentModule(M, getLangOpts()))
1681  return true;
1682  } else {
1683  if (VisibleModules.isVisible(M))
1684  return true;
1685  }
1686 
1687  // Otherwise, it might be visible by virtue of the query being within a
1688  // template instantiation or similar that is permitted to look inside M.
1689 
1690  // Find the extra places where we need to look.
1691  const auto &LookupModules = getLookupModules();
1692  if (LookupModules.empty())
1693  return false;
1694 
1695  // If our lookup set contains the module, it's visible.
1696  if (LookupModules.count(M))
1697  return true;
1698 
1699  // For a module-private query, that's everywhere we get to look.
1700  if (ModulePrivate)
1701  return false;
1702 
1703  // Check whether M is transitively exported to an import of the lookup set.
1704  return llvm::any_of(LookupModules, [&](const Module *LookupM) {
1705  return LookupM->isModuleVisible(M);
1706  });
1707 }
1708 
1709 bool Sema::isVisibleSlow(const NamedDecl *D) {
1710  return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1711 }
1712 
1713 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1714  // FIXME: If there are both visible and hidden declarations, we need to take
1715  // into account whether redeclaration is possible. Example:
1716  //
1717  // Non-imported module:
1718  // int f(T); // #1
1719  // Some TU:
1720  // static int f(U); // #2, not a redeclaration of #1
1721  // int f(T); // #3, finds both, should link with #1 if T != U, but
1722  // // with #2 if T == U; neither should be ambiguous.
1723  for (auto *D : R) {
1724  if (isVisible(D))
1725  return true;
1726  assert(D->isExternallyDeclarable() &&
1727  "should not have hidden, non-externally-declarable result here");
1728  }
1729 
1730  // This function is called once "New" is essentially complete, but before a
1731  // previous declaration is attached. We can't query the linkage of "New" in
1732  // general, because attaching the previous declaration can change the
1733  // linkage of New to match the previous declaration.
1734  //
1735  // However, because we've just determined that there is no *visible* prior
1736  // declaration, we can compute the linkage here. There are two possibilities:
1737  //
1738  // * This is not a redeclaration; it's safe to compute the linkage now.
1739  //
1740  // * This is a redeclaration of a prior declaration that is externally
1741  // redeclarable. In that case, the linkage of the declaration is not
1742  // changed by attaching the prior declaration, because both are externally
1743  // declarable (and thus ExternalLinkage or VisibleNoLinkage).
1744  //
1745  // FIXME: This is subtle and fragile.
1746  return New->isExternallyDeclarable();
1747 }
1748 
1749 /// Retrieve the visible declaration corresponding to D, if any.
1750 ///
1751 /// This routine determines whether the declaration D is visible in the current
1752 /// module, with the current imports. If not, it checks whether any
1753 /// redeclaration of D is visible, and if so, returns that declaration.
1754 ///
1755 /// \returns D, or a visible previous declaration of D, whichever is more recent
1756 /// and visible. If no declaration of D is visible, returns null.
1758  unsigned IDNS) {
1759  assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1760 
1761  for (auto RD : D->redecls()) {
1762  // Don't bother with extra checks if we already know this one isn't visible.
1763  if (RD == D)
1764  continue;
1765 
1766  auto ND = cast<NamedDecl>(RD);
1767  // FIXME: This is wrong in the case where the previous declaration is not
1768  // visible in the same scope as D. This needs to be done much more
1769  // carefully.
1770  if (ND->isInIdentifierNamespace(IDNS) &&
1771  LookupResult::isVisible(SemaRef, ND))
1772  return ND;
1773  }
1774 
1775  return nullptr;
1776 }
1777 
1780  assert(!isVisible(D) && "not in slow case");
1781  return hasVisibleDeclarationImpl(*this, D, Modules,
1782  [](const NamedDecl *) { return true; });
1783 }
1784 
1785 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1786  if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1787  // Namespaces are a bit of a special case: we expect there to be a lot of
1788  // redeclarations of some namespaces, all declarations of a namespace are
1789  // essentially interchangeable, all declarations are found by name lookup
1790  // if any is, and namespaces are never looked up during template
1791  // instantiation. So we benefit from caching the check in this case, and
1792  // it is correct to do so.
1793  auto *Key = ND->getCanonicalDecl();
1794  if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1795  return Acceptable;
1796  auto *Acceptable = isVisible(getSema(), Key)
1797  ? Key
1798  : findAcceptableDecl(getSema(), Key, IDNS);
1799  if (Acceptable)
1800  getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1801  return Acceptable;
1802  }
1803 
1804  return findAcceptableDecl(getSema(), D, IDNS);
1805 }
1806 
1807 /// Perform unqualified name lookup starting from a given
1808 /// scope.
1809 ///
1810 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1811 /// used to find names within the current scope. For example, 'x' in
1812 /// @code
1813 /// int x;
1814 /// int f() {
1815 /// return x; // unqualified name look finds 'x' in the global scope
1816 /// }
1817 /// @endcode
1818 ///
1819 /// Different lookup criteria can find different names. For example, a
1820 /// particular scope can have both a struct and a function of the same
1821 /// name, and each can be found by certain lookup criteria. For more
1822 /// information about lookup criteria, see the documentation for the
1823 /// class LookupCriteria.
1824 ///
1825 /// @param S The scope from which unqualified name lookup will
1826 /// begin. If the lookup criteria permits, name lookup may also search
1827 /// in the parent scopes.
1828 ///
1829 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1830 /// look up and the lookup kind), and is updated with the results of lookup
1831 /// including zero or more declarations and possibly additional information
1832 /// used to diagnose ambiguities.
1833 ///
1834 /// @returns \c true if lookup succeeded and false otherwise.
1835 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1836  DeclarationName Name = R.getLookupName();
1837  if (!Name) return false;
1838 
1839  LookupNameKind NameKind = R.getLookupKind();
1840 
1841  if (!getLangOpts().CPlusPlus) {
1842  // Unqualified name lookup in C/Objective-C is purely lexical, so
1843  // search in the declarations attached to the name.
1844  if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1845  // Find the nearest non-transparent declaration scope.
1846  while (!(S->getFlags() & Scope::DeclScope) ||
1847  (S->getEntity() && S->getEntity()->isTransparentContext()))
1848  S = S->getParent();
1849  }
1850 
1851  // When performing a scope lookup, we want to find local extern decls.
1852  FindLocalExternScope FindLocals(R);
1853 
1854  // Scan up the scope chain looking for a decl that matches this
1855  // identifier that is in the appropriate namespace. This search
1856  // should not take long, as shadowing of names is uncommon, and
1857  // deep shadowing is extremely uncommon.
1858  bool LeftStartingScope = false;
1859 
1860  for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1861  IEnd = IdResolver.end();
1862  I != IEnd; ++I)
1863  if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1864  if (NameKind == LookupRedeclarationWithLinkage) {
1865  // Determine whether this (or a previous) declaration is
1866  // out-of-scope.
1867  if (!LeftStartingScope && !S->isDeclScope(*I))
1868  LeftStartingScope = true;
1869 
1870  // If we found something outside of our starting scope that
1871  // does not have linkage, skip it.
1872  if (LeftStartingScope && !((*I)->hasLinkage())) {
1873  R.setShadowed();
1874  continue;
1875  }
1876  }
1877  else if (NameKind == LookupObjCImplicitSelfParam &&
1878  !isa<ImplicitParamDecl>(*I))
1879  continue;
1880 
1881  R.addDecl(D);
1882 
1883  // Check whether there are any other declarations with the same name
1884  // and in the same scope.
1885  if (I != IEnd) {
1886  // Find the scope in which this declaration was declared (if it
1887  // actually exists in a Scope).
1888  while (S && !S->isDeclScope(D))
1889  S = S->getParent();
1890 
1891  // If the scope containing the declaration is the translation unit,
1892  // then we'll need to perform our checks based on the matching
1893  // DeclContexts rather than matching scopes.
1895  S = nullptr;
1896 
1897  // Compute the DeclContext, if we need it.
1898  DeclContext *DC = nullptr;
1899  if (!S)
1900  DC = (*I)->getDeclContext()->getRedeclContext();
1901 
1902  IdentifierResolver::iterator LastI = I;
1903  for (++LastI; LastI != IEnd; ++LastI) {
1904  if (S) {
1905  // Match based on scope.
1906  if (!S->isDeclScope(*LastI))
1907  break;
1908  } else {
1909  // Match based on DeclContext.
1910  DeclContext *LastDC
1911  = (*LastI)->getDeclContext()->getRedeclContext();
1912  if (!LastDC->Equals(DC))
1913  break;
1914  }
1915 
1916  // If the declaration is in the right namespace and visible, add it.
1917  if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1918  R.addDecl(LastD);
1919  }
1920 
1921  R.resolveKind();
1922  }
1923 
1924  return true;
1925  }
1926  } else {
1927  // Perform C++ unqualified name lookup.
1928  if (CppLookupName(R, S))
1929  return true;
1930  }
1931 
1932  // If we didn't find a use of this identifier, and if the identifier
1933  // corresponds to a compiler builtin, create the decl object for the builtin
1934  // now, injecting it into translation unit scope, and return it.
1935  if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1936  return true;
1937 
1938  // If we didn't find a use of this identifier, the ExternalSource
1939  // may be able to handle the situation.
1940  // Note: some lookup failures are expected!
1941  // See e.g. R.isForRedeclaration().
1942  return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1943 }
1944 
1945 /// Perform qualified name lookup in the namespaces nominated by
1946 /// using directives by the given context.
1947 ///
1948 /// C++98 [namespace.qual]p2:
1949 /// Given X::m (where X is a user-declared namespace), or given \::m
1950 /// (where X is the global namespace), let S be the set of all
1951 /// declarations of m in X and in the transitive closure of all
1952 /// namespaces nominated by using-directives in X and its used
1953 /// namespaces, except that using-directives are ignored in any
1954 /// namespace, including X, directly containing one or more
1955 /// declarations of m. No namespace is searched more than once in
1956 /// the lookup of a name. If S is the empty set, the program is
1957 /// ill-formed. Otherwise, if S has exactly one member, or if the
1958 /// context of the reference is a using-declaration
1959 /// (namespace.udecl), S is the required set of declarations of
1960 /// m. Otherwise if the use of m is not one that allows a unique
1961 /// declaration to be chosen from S, the program is ill-formed.
1962 ///
1963 /// C++98 [namespace.qual]p5:
1964 /// During the lookup of a qualified namespace member name, if the
1965 /// lookup finds more than one declaration of the member, and if one
1966 /// declaration introduces a class name or enumeration name and the
1967 /// other declarations either introduce the same object, the same
1968 /// enumerator or a set of functions, the non-type name hides the
1969 /// class or enumeration name if and only if the declarations are
1970 /// from the same namespace; otherwise (the declarations are from
1971 /// different namespaces), the program is ill-formed.
1973  DeclContext *StartDC) {
1974  assert(StartDC->isFileContext() && "start context is not a file context");
1975 
1976  // We have not yet looked into these namespaces, much less added
1977  // their "using-children" to the queue.
1979 
1980  // We have at least added all these contexts to the queue.
1981  llvm::SmallPtrSet<DeclContext*, 8> Visited;
1982  Visited.insert(StartDC);
1983 
1984  // We have already looked into the initial namespace; seed the queue
1985  // with its using-children.
1986  for (auto *I : StartDC->using_directives()) {
1987  NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1988  if (S.isVisible(I) && Visited.insert(ND).second)
1989  Queue.push_back(ND);
1990  }
1991 
1992  // The easiest way to implement the restriction in [namespace.qual]p5
1993  // is to check whether any of the individual results found a tag
1994  // and, if so, to declare an ambiguity if the final result is not
1995  // a tag.
1996  bool FoundTag = false;
1997  bool FoundNonTag = false;
1998 
2000 
2001  bool Found = false;
2002  while (!Queue.empty()) {
2003  NamespaceDecl *ND = Queue.pop_back_val();
2004 
2005  // We go through some convolutions here to avoid copying results
2006  // between LookupResults.
2007  bool UseLocal = !R.empty();
2008  LookupResult &DirectR = UseLocal ? LocalR : R;
2009  bool FoundDirect = LookupDirect(S, DirectR, ND);
2010 
2011  if (FoundDirect) {
2012  // First do any local hiding.
2013  DirectR.resolveKind();
2014 
2015  // If the local result is a tag, remember that.
2016  if (DirectR.isSingleTagDecl())
2017  FoundTag = true;
2018  else
2019  FoundNonTag = true;
2020 
2021  // Append the local results to the total results if necessary.
2022  if (UseLocal) {
2023  R.addAllDecls(LocalR);
2024  LocalR.clear();
2025  }
2026  }
2027 
2028  // If we find names in this namespace, ignore its using directives.
2029  if (FoundDirect) {
2030  Found = true;
2031  continue;
2032  }
2033 
2034  for (auto I : ND->using_directives()) {
2035  NamespaceDecl *Nom = I->getNominatedNamespace();
2036  if (S.isVisible(I) && Visited.insert(Nom).second)
2037  Queue.push_back(Nom);
2038  }
2039  }
2040 
2041  if (Found) {
2042  if (FoundTag && FoundNonTag)
2044  else
2045  R.resolveKind();
2046  }
2047 
2048  return Found;
2049 }
2050 
2051 /// Callback that looks for any member of a class with the given name.
2053  CXXBasePath &Path, DeclarationName Name) {
2054  RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
2055 
2056  Path.Decls = BaseRecord->lookup(Name);
2057  return !Path.Decls.empty();
2058 }
2059 
2060 /// Determine whether the given set of member declarations contains only
2061 /// static members, nested types, and enumerators.
2062 template<typename InputIterator>
2063 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
2064  Decl *D = (*First)->getUnderlyingDecl();
2065  if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
2066  return true;
2067 
2068  if (isa<CXXMethodDecl>(D)) {
2069  // Determine whether all of the methods are static.
2070  bool AllMethodsAreStatic = true;
2071  for(; First != Last; ++First) {
2072  D = (*First)->getUnderlyingDecl();
2073 
2074  if (!isa<CXXMethodDecl>(D)) {
2075  assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
2076  break;
2077  }
2078 
2079  if (!cast<CXXMethodDecl>(D)->isStatic()) {
2080  AllMethodsAreStatic = false;
2081  break;
2082  }
2083  }
2084 
2085  if (AllMethodsAreStatic)
2086  return true;
2087  }
2088 
2089  return false;
2090 }
2091 
2092 /// Perform qualified name lookup into a given context.
2093 ///
2094 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
2095 /// names when the context of those names is explicit specified, e.g.,
2096 /// "std::vector" or "x->member", or as part of unqualified name lookup.
2097 ///
2098 /// Different lookup criteria can find different names. For example, a
2099 /// particular scope can have both a struct and a function of the same
2100 /// name, and each can be found by certain lookup criteria. For more
2101 /// information about lookup criteria, see the documentation for the
2102 /// class LookupCriteria.
2103 ///
2104 /// \param R captures both the lookup criteria and any lookup results found.
2105 ///
2106 /// \param LookupCtx The context in which qualified name lookup will
2107 /// search. If the lookup criteria permits, name lookup may also search
2108 /// in the parent contexts or (for C++ classes) base classes.
2109 ///
2110 /// \param InUnqualifiedLookup true if this is qualified name lookup that
2111 /// occurs as part of unqualified name lookup.
2112 ///
2113 /// \returns true if lookup succeeded, false if it failed.
2115  bool InUnqualifiedLookup) {
2116  assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2117 
2118  if (!R.getLookupName())
2119  return false;
2120 
2121  // Make sure that the declaration context is complete.
2122  assert((!isa<TagDecl>(LookupCtx) ||
2123  LookupCtx->isDependentContext() ||
2124  cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
2125  cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
2126  "Declaration context must already be complete!");
2127 
2128  struct QualifiedLookupInScope {
2129  bool oldVal;
2130  DeclContext *Context;
2131  // Set flag in DeclContext informing debugger that we're looking for qualified name
2132  QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2133  oldVal = ctx->setUseQualifiedLookup();
2134  }
2135  ~QualifiedLookupInScope() {
2136  Context->setUseQualifiedLookup(oldVal);
2137  }
2138  } QL(LookupCtx);
2139 
2140  if (LookupDirect(*this, R, LookupCtx)) {
2141  R.resolveKind();
2142  if (isa<CXXRecordDecl>(LookupCtx))
2143  R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2144  return true;
2145  }
2146 
2147  // Don't descend into implied contexts for redeclarations.
2148  // C++98 [namespace.qual]p6:
2149  // In a declaration for a namespace member in which the
2150  // declarator-id is a qualified-id, given that the qualified-id
2151  // for the namespace member has the form
2152  // nested-name-specifier unqualified-id
2153  // the unqualified-id shall name a member of the namespace
2154  // designated by the nested-name-specifier.
2155  // See also [class.mfct]p5 and [class.static.data]p2.
2156  if (R.isForRedeclaration())
2157  return false;
2158 
2159  // If this is a namespace, look it up in the implied namespaces.
2160  if (LookupCtx->isFileContext())
2161  return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2162 
2163  // If this isn't a C++ class, we aren't allowed to look into base
2164  // classes, we're done.
2165  CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2166  if (!LookupRec || !LookupRec->getDefinition())
2167  return false;
2168 
2169  // If we're performing qualified name lookup into a dependent class,
2170  // then we are actually looking into a current instantiation. If we have any
2171  // dependent base classes, then we either have to delay lookup until
2172  // template instantiation time (at which point all bases will be available)
2173  // or we have to fail.
2174  if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2175  LookupRec->hasAnyDependentBases()) {
2177  return false;
2178  }
2179 
2180  // Perform lookup into our base classes.
2181  CXXBasePaths Paths;
2182  Paths.setOrigin(LookupRec);
2183 
2184  // Look for this member in our base classes
2185  bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2186  DeclarationName Name) = nullptr;
2187  switch (R.getLookupKind()) {
2188  case LookupObjCImplicitSelfParam:
2189  case LookupOrdinaryName:
2190  case LookupMemberName:
2191  case LookupRedeclarationWithLinkage:
2192  case LookupLocalFriendName:
2193  BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2194  break;
2195 
2196  case LookupTagName:
2197  BaseCallback = &CXXRecordDecl::FindTagMember;
2198  break;
2199 
2200  case LookupAnyName:
2201  BaseCallback = &LookupAnyMember;
2202  break;
2203 
2204  case LookupOMPReductionName:
2205  BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2206  break;
2207 
2208  case LookupOMPMapperName:
2209  BaseCallback = &CXXRecordDecl::FindOMPMapperMember;
2210  break;
2211 
2212  case LookupUsingDeclName:
2213  // This lookup is for redeclarations only.
2214 
2215  case LookupOperatorName:
2216  case LookupNamespaceName:
2217  case LookupObjCProtocolName:
2218  case LookupLabel:
2219  // These lookups will never find a member in a C++ class (or base class).
2220  return false;
2221 
2222  case LookupNestedNameSpecifierName:
2224  break;
2225  }
2226 
2227  DeclarationName Name = R.getLookupName();
2228  if (!LookupRec->lookupInBases(
2229  [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2230  return BaseCallback(Specifier, Path, Name);
2231  },
2232  Paths))
2233  return false;
2234 
2235  R.setNamingClass(LookupRec);
2236 
2237  // C++ [class.member.lookup]p2:
2238  // [...] If the resulting set of declarations are not all from
2239  // sub-objects of the same type, or the set has a nonstatic member
2240  // and includes members from distinct sub-objects, there is an
2241  // ambiguity and the program is ill-formed. Otherwise that set is
2242  // the result of the lookup.
2243  QualType SubobjectType;
2244  int SubobjectNumber = 0;
2245  AccessSpecifier SubobjectAccess = AS_none;
2246 
2247  for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2248  Path != PathEnd; ++Path) {
2249  const CXXBasePathElement &PathElement = Path->back();
2250 
2251  // Pick the best (i.e. most permissive i.e. numerically lowest) access
2252  // across all paths.
2253  SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2254 
2255  // Determine whether we're looking at a distinct sub-object or not.
2256  if (SubobjectType.isNull()) {
2257  // This is the first subobject we've looked at. Record its type.
2258  SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2259  SubobjectNumber = PathElement.SubobjectNumber;
2260  continue;
2261  }
2262 
2263  if (SubobjectType
2264  != Context.getCanonicalType(PathElement.Base->getType())) {
2265  // We found members of the given name in two subobjects of
2266  // different types. If the declaration sets aren't the same, this
2267  // lookup is ambiguous.
2268  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2269  CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2270  DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2271  DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2272 
2273  // Get the decl that we should use for deduplicating this lookup.
2274  auto GetRepresentativeDecl = [&](NamedDecl *D) -> Decl * {
2275  // C++ [temp.local]p3:
2276  // A lookup that finds an injected-class-name (10.2) can result in
2277  // an ambiguity in certain cases (for example, if it is found in
2278  // more than one base class). If all of the injected-class-names
2279  // that are found refer to specializations of the same class
2280  // template, and if the name is used as a template-name, the
2281  // reference refers to the class template itself and not a
2282  // specialization thereof, and is not ambiguous.
2283  if (R.isTemplateNameLookup())
2284  if (auto *TD = getAsTemplateNameDecl(D))
2285  D = TD;
2286  return D->getUnderlyingDecl()->getCanonicalDecl();
2287  };
2288 
2289  while (FirstD != FirstPath->Decls.end() &&
2290  CurrentD != Path->Decls.end()) {
2291  if (GetRepresentativeDecl(*FirstD) !=
2292  GetRepresentativeDecl(*CurrentD))
2293  break;
2294 
2295  ++FirstD;
2296  ++CurrentD;
2297  }
2298 
2299  if (FirstD == FirstPath->Decls.end() &&
2300  CurrentD == Path->Decls.end())
2301  continue;
2302  }
2303 
2305  return true;
2306  }
2307 
2308  if (SubobjectNumber != PathElement.SubobjectNumber) {
2309  // We have a different subobject of the same type.
2310 
2311  // C++ [class.member.lookup]p5:
2312  // A static member, a nested type or an enumerator defined in
2313  // a base class T can unambiguously be found even if an object
2314  // has more than one base class subobject of type T.
2315  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2316  continue;
2317 
2318  // We have found a nonstatic member name in multiple, distinct
2319  // subobjects. Name lookup is ambiguous.
2320  R.setAmbiguousBaseSubobjects(Paths);
2321  return true;
2322  }
2323  }
2324 
2325  // Lookup in a base class succeeded; return these results.
2326 
2327  for (auto *D : Paths.front().Decls) {
2328  AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2329  D->getAccess());
2330  R.addDecl(D, AS);
2331  }
2332  R.resolveKind();
2333  return true;
2334 }
2335 
2336 /// Performs qualified name lookup or special type of lookup for
2337 /// "__super::" scope specifier.
2338 ///
2339 /// This routine is a convenience overload meant to be called from contexts
2340 /// that need to perform a qualified name lookup with an optional C++ scope
2341 /// specifier that might require special kind of lookup.
2342 ///
2343 /// \param R captures both the lookup criteria and any lookup results found.
2344 ///
2345 /// \param LookupCtx The context in which qualified name lookup will
2346 /// search.
2347 ///
2348 /// \param SS An optional C++ scope-specifier.
2349 ///
2350 /// \returns true if lookup succeeded, false if it failed.
2352  CXXScopeSpec &SS) {
2353  auto *NNS = SS.getScopeRep();
2354  if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2355  return LookupInSuper(R, NNS->getAsRecordDecl());
2356  else
2357 
2358  return LookupQualifiedName(R, LookupCtx);
2359 }
2360 
2361 /// Performs name lookup for a name that was parsed in the
2362 /// source code, and may contain a C++ scope specifier.
2363 ///
2364 /// This routine is a convenience routine meant to be called from
2365 /// contexts that receive a name and an optional C++ scope specifier
2366 /// (e.g., "N::M::x"). It will then perform either qualified or
2367 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2368 /// respectively) on the given name and return those results. It will
2369 /// perform a special type of lookup for "__super::" scope specifier.
2370 ///
2371 /// @param S The scope from which unqualified name lookup will
2372 /// begin.
2373 ///
2374 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2375 ///
2376 /// @param EnteringContext Indicates whether we are going to enter the
2377 /// context of the scope-specifier SS (if present).
2378 ///
2379 /// @returns True if any decls were found (but possibly ambiguous)
2381  bool AllowBuiltinCreation, bool EnteringContext) {
2382  if (SS && SS->isInvalid()) {
2383  // When the scope specifier is invalid, don't even look for
2384  // anything.
2385  return false;
2386  }
2387 
2388  if (SS && SS->isSet()) {
2389  NestedNameSpecifier *NNS = SS->getScopeRep();
2390  if (NNS->getKind() == NestedNameSpecifier::Super)
2391  return LookupInSuper(R, NNS->getAsRecordDecl());
2392 
2393  if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2394  // We have resolved the scope specifier to a particular declaration
2395  // contex, and will perform name lookup in that context.
2396  if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2397  return false;
2398 
2399  R.setContextRange(SS->getRange());
2400  return LookupQualifiedName(R, DC);
2401  }
2402 
2403  // We could not resolve the scope specified to a specific declaration
2404  // context, which means that SS refers to an unknown specialization.
2405  // Name lookup can't find anything in this case.
2407  R.setContextRange(SS->getRange());
2408  return false;
2409  }
2410 
2411  // Perform unqualified name lookup starting in the given scope.
2412  return LookupName(R, S, AllowBuiltinCreation);
2413 }
2414 
2415 /// Perform qualified name lookup into all base classes of the given
2416 /// class.
2417 ///
2418 /// \param R captures both the lookup criteria and any lookup results found.
2419 ///
2420 /// \param Class The context in which qualified name lookup will
2421 /// search. Name lookup will search in all base classes merging the results.
2422 ///
2423 /// @returns True if any decls were found (but possibly ambiguous)
2425  // The access-control rules we use here are essentially the rules for
2426  // doing a lookup in Class that just magically skipped the direct
2427  // members of Class itself. That is, the naming class is Class, and the
2428  // access includes the access of the base.
2429  for (const auto &BaseSpec : Class->bases()) {
2430  CXXRecordDecl *RD = cast<CXXRecordDecl>(
2431  BaseSpec.getType()->castAs<RecordType>()->getDecl());
2432  LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2433  Result.setBaseObjectType(Context.getRecordType(Class));
2434  LookupQualifiedName(Result, RD);
2435 
2436  // Copy the lookup results into the target, merging the base's access into
2437  // the path access.
2438  for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2439  R.addDecl(I.getDecl(),
2440  CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2441  I.getAccess()));
2442  }
2443 
2444  Result.suppressDiagnostics();
2445  }
2446 
2447  R.resolveKind();
2448  R.setNamingClass(Class);
2449 
2450  return !R.empty();
2451 }
2452 
2453 /// Produce a diagnostic describing the ambiguity that resulted
2454 /// from name lookup.
2455 ///
2456 /// \param Result The result of the ambiguous lookup to be diagnosed.
2458  assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2459 
2460  DeclarationName Name = Result.getLookupName();
2461  SourceLocation NameLoc = Result.getNameLoc();
2462  SourceRange LookupRange = Result.getContextRange();
2463 
2464  switch (Result.getAmbiguityKind()) {
2466  CXXBasePaths *Paths = Result.getBasePaths();
2467  QualType SubobjectType = Paths->front().back().Base->getType();
2468  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2469  << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2470  << LookupRange;
2471 
2472  DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2473  while (isa<CXXMethodDecl>(*Found) &&
2474  cast<CXXMethodDecl>(*Found)->isStatic())
2475  ++Found;
2476 
2477  Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2478  break;
2479  }
2480 
2482  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2483  << Name << LookupRange;
2484 
2485  CXXBasePaths *Paths = Result.getBasePaths();
2486  std::set<Decl *> DeclsPrinted;
2487  for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2488  PathEnd = Paths->end();
2489  Path != PathEnd; ++Path) {
2490  Decl *D = Path->Decls.front();
2491  if (DeclsPrinted.insert(D).second)
2492  Diag(D->getLocation(), diag::note_ambiguous_member_found);
2493  }
2494  break;
2495  }
2496 
2498  Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2499 
2500  llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2501 
2502  for (auto *D : Result)
2503  if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2504  TagDecls.insert(TD);
2505  Diag(TD->getLocation(), diag::note_hidden_tag);
2506  }
2507 
2508  for (auto *D : Result)
2509  if (!isa<TagDecl>(D))
2510  Diag(D->getLocation(), diag::note_hiding_object);
2511 
2512  // For recovery purposes, go ahead and implement the hiding.
2513  LookupResult::Filter F = Result.makeFilter();
2514  while (F.hasNext()) {
2515  if (TagDecls.count(F.next()))
2516  F.erase();
2517  }
2518  F.done();
2519  break;
2520  }
2521 
2523  Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2524 
2525  for (auto *D : Result)
2526  Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2527  break;
2528  }
2529  }
2530 }
2531 
2532 namespace {
2533  struct AssociatedLookup {
2534  AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2535  Sema::AssociatedNamespaceSet &Namespaces,
2536  Sema::AssociatedClassSet &Classes)
2537  : S(S), Namespaces(Namespaces), Classes(Classes),
2538  InstantiationLoc(InstantiationLoc) {
2539  }
2540 
2541  bool addClassTransitive(CXXRecordDecl *RD) {
2542  Classes.insert(RD);
2543  return ClassesTransitive.insert(RD);
2544  }
2545 
2546  Sema &S;
2547  Sema::AssociatedNamespaceSet &Namespaces;
2548  Sema::AssociatedClassSet &Classes;
2549  SourceLocation InstantiationLoc;
2550 
2551  private:
2552  Sema::AssociatedClassSet ClassesTransitive;
2553  };
2554 } // end anonymous namespace
2555 
2556 static void
2557 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2558 
2559 // Given the declaration context \param Ctx of a class, class template or
2560 // enumeration, add the associated namespaces to \param Namespaces as described
2561 // in [basic.lookup.argdep]p2.
2563  DeclContext *Ctx) {
2564  // The exact wording has been changed in C++14 as a result of
2565  // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
2566  // to all language versions since it is possible to return a local type
2567  // from a lambda in C++11.
2568  //
2569  // C++14 [basic.lookup.argdep]p2:
2570  // If T is a class type [...]. Its associated namespaces are the innermost
2571  // enclosing namespaces of its associated classes. [...]
2572  //
2573  // If T is an enumeration type, its associated namespace is the innermost
2574  // enclosing namespace of its declaration. [...]
2575 
2576  // We additionally skip inline namespaces. The innermost non-inline namespace
2577  // contains all names of all its nested inline namespaces anyway, so we can
2578  // replace the entire inline namespace tree with its root.
2579  while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
2580  Ctx = Ctx->getParent();
2581 
2582  Namespaces.insert(Ctx->getPrimaryContext());
2583 }
2584 
2585 // Add the associated classes and namespaces for argument-dependent
2586 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
2587 static void
2588 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2589  const TemplateArgument &Arg) {
2590  // C++ [basic.lookup.argdep]p2, last bullet:
2591  // -- [...] ;
2592  switch (Arg.getKind()) {
2594  break;
2595 
2597  // [...] the namespaces and classes associated with the types of the
2598  // template arguments provided for template type parameters (excluding
2599  // template template parameters)
2601  break;
2602 
2605  // [...] the namespaces in which any template template arguments are
2606  // defined; and the classes in which any member templates used as
2607  // template template arguments are defined.
2609  if (ClassTemplateDecl *ClassTemplate
2610  = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2611  DeclContext *Ctx = ClassTemplate->getDeclContext();
2612  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2613  Result.Classes.insert(EnclosingClass);
2614  // Add the associated namespace for this class.
2615  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2616  }
2617  break;
2618  }
2619 
2624  // [Note: non-type template arguments do not contribute to the set of
2625  // associated namespaces. ]
2626  break;
2627 
2629  for (const auto &P : Arg.pack_elements())
2631  break;
2632  }
2633 }
2634 
2635 // Add the associated classes and namespaces for argument-dependent lookup
2636 // with an argument of class type (C++ [basic.lookup.argdep]p2).
2637 static void
2638 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2639  CXXRecordDecl *Class) {
2640 
2641  // Just silently ignore anything whose name is __va_list_tag.
2642  if (Class->getDeclName() == Result.S.VAListTagName)
2643  return;
2644 
2645  // C++ [basic.lookup.argdep]p2:
2646  // [...]
2647  // -- If T is a class type (including unions), its associated
2648  // classes are: the class itself; the class of which it is a
2649  // member, if any; and its direct and indirect base classes.
2650  // Its associated namespaces are the innermost enclosing
2651  // namespaces of its associated classes.
2652 
2653  // Add the class of which it is a member, if any.
2654  DeclContext *Ctx = Class->getDeclContext();
2655  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2656  Result.Classes.insert(EnclosingClass);
2657 
2658  // Add the associated namespace for this class.
2659  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2660 
2661  // -- If T is a template-id, its associated namespaces and classes are
2662  // the namespace in which the template is defined; for member
2663  // templates, the member template's class; the namespaces and classes
2664  // associated with the types of the template arguments provided for
2665  // template type parameters (excluding template template parameters); the
2666  // namespaces in which any template template arguments are defined; and
2667  // the classes in which any member templates used as template template
2668  // arguments are defined. [Note: non-type template arguments do not
2669  // contribute to the set of associated namespaces. ]
2671  = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2672  DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2673  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2674  Result.Classes.insert(EnclosingClass);
2675  // Add the associated namespace for this class.
2676  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2677 
2678  const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2679  for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2680  addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2681  }
2682 
2683  // Add the class itself. If we've already transitively visited this class,
2684  // we don't need to visit base classes.
2685  if (!Result.addClassTransitive(Class))
2686  return;
2687 
2688  // Only recurse into base classes for complete types.
2689  if (!Result.S.isCompleteType(Result.InstantiationLoc,
2690  Result.S.Context.getRecordType(Class)))
2691  return;
2692 
2693  // Add direct and indirect base classes along with their associated
2694  // namespaces.
2696  Bases.push_back(Class);
2697  while (!Bases.empty()) {
2698  // Pop this class off the stack.
2699  Class = Bases.pop_back_val();
2700 
2701  // Visit the base classes.
2702  for (const auto &Base : Class->bases()) {
2703  const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2704  // In dependent contexts, we do ADL twice, and the first time around,
2705  // the base type might be a dependent TemplateSpecializationType, or a
2706  // TemplateTypeParmType. If that happens, simply ignore it.
2707  // FIXME: If we want to support export, we probably need to add the
2708  // namespace of the template in a TemplateSpecializationType, or even
2709  // the classes and namespaces of known non-dependent arguments.
2710  if (!BaseType)
2711  continue;
2712  CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2713  if (Result.addClassTransitive(BaseDecl)) {
2714  // Find the associated namespace for this base class.
2715  DeclContext *BaseCtx = BaseDecl->getDeclContext();
2716  CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2717 
2718  // Make sure we visit the bases of this base class.
2719  if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2720  Bases.push_back(BaseDecl);
2721  }
2722  }
2723  }
2724 }
2725 
2726 // Add the associated classes and namespaces for
2727 // argument-dependent lookup with an argument of type T
2728 // (C++ [basic.lookup.koenig]p2).
2729 static void
2730 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2731  // C++ [basic.lookup.koenig]p2:
2732  //
2733  // For each argument type T in the function call, there is a set
2734  // of zero or more associated namespaces and a set of zero or more
2735  // associated classes to be considered. The sets of namespaces and
2736  // classes is determined entirely by the types of the function
2737  // arguments (and the namespace of any template template
2738  // argument). Typedef names and using-declarations used to specify
2739  // the types do not contribute to this set. The sets of namespaces
2740  // and classes are determined in the following way:
2741 
2743  const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2744 
2745  while (true) {
2746  switch (T->getTypeClass()) {
2747 
2748 #define TYPE(Class, Base)
2749 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2750 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2751 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2752 #define ABSTRACT_TYPE(Class, Base)
2753 #include "clang/AST/TypeNodes.def"
2754  // T is canonical. We can also ignore dependent types because
2755  // we don't need to do ADL at the definition point, but if we
2756  // wanted to implement template export (or if we find some other
2757  // use for associated classes and namespaces...) this would be
2758  // wrong.
2759  break;
2760 
2761  // -- If T is a pointer to U or an array of U, its associated
2762  // namespaces and classes are those associated with U.
2763  case Type::Pointer:
2764  T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2765  continue;
2766  case Type::ConstantArray:
2767  case Type::IncompleteArray:
2768  case Type::VariableArray:
2769  T = cast<ArrayType>(T)->getElementType().getTypePtr();
2770  continue;
2771 
2772  // -- If T is a fundamental type, its associated sets of
2773  // namespaces and classes are both empty.
2774  case Type::Builtin:
2775  break;
2776 
2777  // -- If T is a class type (including unions), its associated
2778  // classes are: the class itself; the class of which it is
2779  // a member, if any; and its direct and indirect base classes.
2780  // Its associated namespaces are the innermost enclosing
2781  // namespaces of its associated classes.
2782  case Type::Record: {
2783  CXXRecordDecl *Class =
2784  cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2785  addAssociatedClassesAndNamespaces(Result, Class);
2786  break;
2787  }
2788 
2789  // -- If T is an enumeration type, its associated namespace
2790  // is the innermost enclosing namespace of its declaration.
2791  // If it is a class member, its associated class is the
2792  // member’s class; else it has no associated class.
2793  case Type::Enum: {
2794  EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2795 
2796  DeclContext *Ctx = Enum->getDeclContext();
2797  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2798  Result.Classes.insert(EnclosingClass);
2799 
2800  // Add the associated namespace for this enumeration.
2801  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2802 
2803  break;
2804  }
2805 
2806  // -- If T is a function type, its associated namespaces and
2807  // classes are those associated with the function parameter
2808  // types and those associated with the return type.
2809  case Type::FunctionProto: {
2810  const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2811  for (const auto &Arg : Proto->param_types())
2812  Queue.push_back(Arg.getTypePtr());
2813  // fallthrough
2814  LLVM_FALLTHROUGH;
2815  }
2816  case Type::FunctionNoProto: {
2817  const FunctionType *FnType = cast<FunctionType>(T);
2818  T = FnType->getReturnType().getTypePtr();
2819  continue;
2820  }
2821 
2822  // -- If T is a pointer to a member function of a class X, its
2823  // associated namespaces and classes are those associated
2824  // with the function parameter types and return type,
2825  // together with those associated with X.
2826  //
2827  // -- If T is a pointer to a data member of class X, its
2828  // associated namespaces and classes are those associated
2829  // with the member type together with those associated with
2830  // X.
2831  case Type::MemberPointer: {
2832  const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2833 
2834  // Queue up the class type into which this points.
2835  Queue.push_back(MemberPtr->getClass());
2836 
2837  // And directly continue with the pointee type.
2838  T = MemberPtr->getPointeeType().getTypePtr();
2839  continue;
2840  }
2841 
2842  // As an extension, treat this like a normal pointer.
2843  case Type::BlockPointer:
2844  T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2845  continue;
2846 
2847  // References aren't covered by the standard, but that's such an
2848  // obvious defect that we cover them anyway.
2849  case Type::LValueReference:
2850  case Type::RValueReference:
2851  T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2852  continue;
2853 
2854  // These are fundamental types.
2855  case Type::Vector:
2856  case Type::ExtVector:
2857  case Type::Complex:
2858  break;
2859 
2860  // Non-deduced auto types only get here for error cases.
2861  case Type::Auto:
2862  case Type::DeducedTemplateSpecialization:
2863  break;
2864 
2865  // If T is an Objective-C object or interface type, or a pointer to an
2866  // object or interface type, the associated namespace is the global
2867  // namespace.
2868  case Type::ObjCObject:
2869  case Type::ObjCInterface:
2870  case Type::ObjCObjectPointer:
2871  Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2872  break;
2873 
2874  // Atomic types are just wrappers; use the associations of the
2875  // contained type.
2876  case Type::Atomic:
2877  T = cast<AtomicType>(T)->getValueType().getTypePtr();
2878  continue;
2879  case Type::Pipe:
2880  T = cast<PipeType>(T)->getElementType().getTypePtr();
2881  continue;
2882  }
2883 
2884  if (Queue.empty())
2885  break;
2886  T = Queue.pop_back_val();
2887  }
2888 }
2889 
2890 /// Find the associated classes and namespaces for
2891 /// argument-dependent lookup for a call with the given set of
2892 /// arguments.
2893 ///
2894 /// This routine computes the sets of associated classes and associated
2895 /// namespaces searched by argument-dependent lookup
2896 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2898  SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2899  AssociatedNamespaceSet &AssociatedNamespaces,
2900  AssociatedClassSet &AssociatedClasses) {
2901  AssociatedNamespaces.clear();
2902  AssociatedClasses.clear();
2903 
2904  AssociatedLookup Result(*this, InstantiationLoc,
2905  AssociatedNamespaces, AssociatedClasses);
2906 
2907  // C++ [basic.lookup.koenig]p2:
2908  // For each argument type T in the function call, there is a set
2909  // of zero or more associated namespaces and a set of zero or more
2910  // associated classes to be considered. The sets of namespaces and
2911  // classes is determined entirely by the types of the function
2912  // arguments (and the namespace of any template template
2913  // argument).
2914  for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2915  Expr *Arg = Args[ArgIdx];
2916 
2917  if (Arg->getType() != Context.OverloadTy) {
2919  continue;
2920  }
2921 
2922  // [...] In addition, if the argument is the name or address of a
2923  // set of overloaded functions and/or function templates, its
2924  // associated classes and namespaces are the union of those
2925  // associated with each of the members of the set: the namespace
2926  // in which the function or function template is defined and the
2927  // classes and namespaces associated with its (non-dependent)
2928  // parameter types and return type.
2930 
2931  for (const NamedDecl *D : OE->decls()) {
2932  // Look through any using declarations to find the underlying function.
2933  const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2934 
2935  // Add the classes and namespaces associated with the parameter
2936  // types and return type of this function.
2937  addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2938  }
2939  }
2940 }
2941 
2943  SourceLocation Loc,
2944  LookupNameKind NameKind,
2945  RedeclarationKind Redecl) {
2946  LookupResult R(*this, Name, Loc, NameKind, Redecl);
2947  LookupName(R, S);
2948  return R.getAsSingle<NamedDecl>();
2949 }
2950 
2951 /// Find the protocol with the given name, if any.
2953  SourceLocation IdLoc,
2954  RedeclarationKind Redecl) {
2955  Decl *D = LookupSingleName(TUScope, II, IdLoc,
2956  LookupObjCProtocolName, Redecl);
2957  return cast_or_null<ObjCProtocolDecl>(D);
2958 }
2959 
2961  QualType T1, QualType T2,
2962  UnresolvedSetImpl &Functions) {
2963  // C++ [over.match.oper]p3:
2964  // -- The set of non-member candidates is the result of the
2965  // unqualified lookup of operator@ in the context of the
2966  // expression according to the usual rules for name lookup in
2967  // unqualified function calls (3.4.2) except that all member
2968  // functions are ignored.
2970  LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2971  LookupName(Operators, S);
2972 
2973  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2974  Functions.append(Operators.begin(), Operators.end());
2975 }
2976 
2979  bool ConstArg,
2980  bool VolatileArg,
2981  bool RValueThis,
2982  bool ConstThis,
2983  bool VolatileThis) {
2984  assert(CanDeclareSpecialMemberFunction(RD) &&
2985  "doing special member lookup into record that isn't fully complete");
2986  RD = RD->getDefinition();
2987  if (RValueThis || ConstThis || VolatileThis)
2988  assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2989  "constructors and destructors always have unqualified lvalue this");
2990  if (ConstArg || VolatileArg)
2991  assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2992  "parameter-less special members can't have qualified arguments");
2993 
2994  // FIXME: Get the caller to pass in a location for the lookup.
2995  SourceLocation LookupLoc = RD->getLocation();
2996 
2997  llvm::FoldingSetNodeID ID;
2998  ID.AddPointer(RD);
2999  ID.AddInteger(SM);
3000  ID.AddInteger(ConstArg);
3001  ID.AddInteger(VolatileArg);
3002  ID.AddInteger(RValueThis);
3003  ID.AddInteger(ConstThis);
3004  ID.AddInteger(VolatileThis);
3005 
3006  void *InsertPoint;
3008  SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
3009 
3010  // This was already cached
3011  if (Result)
3012  return *Result;
3013 
3014  Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3015  Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3016  SpecialMemberCache.InsertNode(Result, InsertPoint);
3017 
3018  if (SM == CXXDestructor) {
3019  if (RD->needsImplicitDestructor())
3020  DeclareImplicitDestructor(RD);
3021  CXXDestructorDecl *DD = RD->getDestructor();
3022  assert(DD && "record without a destructor");
3023  Result->setMethod(DD);
3024  Result->setKind(DD->isDeleted() ?
3025  SpecialMemberOverloadResult::NoMemberOrDeleted :
3026  SpecialMemberOverloadResult::Success);
3027  return *Result;
3028  }
3029 
3030  // Prepare for overload resolution. Here we construct a synthetic argument
3031  // if necessary and make sure that implicit functions are declared.
3032  CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
3033  DeclarationName Name;
3034  Expr *Arg = nullptr;
3035  unsigned NumArgs;
3036 
3037  QualType ArgType = CanTy;
3038  ExprValueKind VK = VK_LValue;
3039 
3040  if (SM == CXXDefaultConstructor) {
3041  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3042  NumArgs = 0;
3044  DeclareImplicitDefaultConstructor(RD);
3045  } else {
3046  if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
3047  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3048  if (RD->needsImplicitCopyConstructor())
3049  DeclareImplicitCopyConstructor(RD);
3050  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
3051  DeclareImplicitMoveConstructor(RD);
3052  } else {
3053  Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
3054  if (RD->needsImplicitCopyAssignment())
3055  DeclareImplicitCopyAssignment(RD);
3056  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
3057  DeclareImplicitMoveAssignment(RD);
3058  }
3059 
3060  if (ConstArg)
3061  ArgType.addConst();
3062  if (VolatileArg)
3063  ArgType.addVolatile();
3064 
3065  // This isn't /really/ specified by the standard, but it's implied
3066  // we should be working from an RValue in the case of move to ensure
3067  // that we prefer to bind to rvalue references, and an LValue in the
3068  // case of copy to ensure we don't bind to rvalue references.
3069  // Possibly an XValue is actually correct in the case of move, but
3070  // there is no semantic difference for class types in this restricted
3071  // case.
3072  if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
3073  VK = VK_LValue;
3074  else
3075  VK = VK_RValue;
3076  }
3077 
3078  OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
3079 
3080  if (SM != CXXDefaultConstructor) {
3081  NumArgs = 1;
3082  Arg = &FakeArg;
3083  }
3084 
3085  // Create the object argument
3086  QualType ThisTy = CanTy;
3087  if (ConstThis)
3088  ThisTy.addConst();
3089  if (VolatileThis)
3090  ThisTy.addVolatile();
3091  Expr::Classification Classification =
3092  OpaqueValueExpr(LookupLoc, ThisTy,
3093  RValueThis ? VK_RValue : VK_LValue).Classify(Context);
3094 
3095  // Now we perform lookup on the name we computed earlier and do overload
3096  // resolution. Lookup is only performed directly into the class since there
3097  // will always be a (possibly implicit) declaration to shadow any others.
3099  DeclContext::lookup_result R = RD->lookup(Name);
3100 
3101  if (R.empty()) {
3102  // We might have no default constructor because we have a lambda's closure
3103  // type, rather than because there's some other declared constructor.
3104  // Every class has a copy/move constructor, copy/move assignment, and
3105  // destructor.
3106  assert(SM == CXXDefaultConstructor &&
3107  "lookup for a constructor or assignment operator was empty");
3108  Result->setMethod(nullptr);
3109  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3110  return *Result;
3111  }
3112 
3113  // Copy the candidates as our processing of them may load new declarations
3114  // from an external source and invalidate lookup_result.
3115  SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
3116 
3117  for (NamedDecl *CandDecl : Candidates) {
3118  if (CandDecl->isInvalidDecl())
3119  continue;
3120 
3121  DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
3122  auto CtorInfo = getConstructorInfo(Cand);
3123  if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
3124  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3125  AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
3126  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3127  else if (CtorInfo)
3128  AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
3129  llvm::makeArrayRef(&Arg, NumArgs), OCS,
3130  /*SuppressUserConversions*/ true);
3131  else
3132  AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
3133  /*SuppressUserConversions*/ true);
3134  } else if (FunctionTemplateDecl *Tmpl =
3135  dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
3136  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3137  AddMethodTemplateCandidate(
3138  Tmpl, Cand, RD, nullptr, ThisTy, Classification,
3139  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3140  else if (CtorInfo)
3141  AddTemplateOverloadCandidate(
3142  CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
3143  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3144  else
3145  AddTemplateOverloadCandidate(
3146  Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3147  } else {
3148  assert(isa<UsingDecl>(Cand.getDecl()) &&
3149  "illegal Kind of operator = Decl");
3150  }
3151  }
3152 
3154  switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
3155  case OR_Success:
3156  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3157  Result->setKind(SpecialMemberOverloadResult::Success);
3158  break;
3159 
3160  case OR_Deleted:
3161  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3162  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3163  break;
3164 
3165  case OR_Ambiguous:
3166  Result->setMethod(nullptr);
3167  Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3168  break;
3169 
3170  case OR_No_Viable_Function:
3171  Result->setMethod(nullptr);
3172  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3173  break;
3174  }
3175 
3176  return *Result;
3177 }
3178 
3179 /// Look up the default constructor for the given class.
3182  LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3183  false, false);
3184 
3185  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3186 }
3187 
3188 /// Look up the copying constructor for the given class.
3190  unsigned Quals) {
3191  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3192  "non-const, non-volatile qualifiers for copy ctor arg");
3194  LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
3195  Quals & Qualifiers::Volatile, false, false, false);
3196 
3197  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3198 }
3199 
3200 /// Look up the moving constructor for the given class.
3202  unsigned Quals) {
3204  LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
3205  Quals & Qualifiers::Volatile, false, false, false);
3206 
3207  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3208 }
3209 
3210 /// Look up the constructors for the given class.
3212  // If the implicit constructors have not yet been declared, do so now.
3213  if (CanDeclareSpecialMemberFunction(Class)) {
3214  if (Class->needsImplicitDefaultConstructor())
3215  DeclareImplicitDefaultConstructor(Class);
3216  if (Class->needsImplicitCopyConstructor())
3217  DeclareImplicitCopyConstructor(Class);
3218  if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3219  DeclareImplicitMoveConstructor(Class);
3220  }
3221 
3222  CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3224  return Class->lookup(Name);
3225 }
3226 
3227 /// Look up the copying assignment operator for the given class.
3229  unsigned Quals, bool RValueThis,
3230  unsigned ThisQuals) {
3231  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3232  "non-const, non-volatile qualifiers for copy assignment arg");
3233  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3234  "non-const, non-volatile qualifiers for copy assignment this");
3236  LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3237  Quals & Qualifiers::Volatile, RValueThis,
3238  ThisQuals & Qualifiers::Const,
3239  ThisQuals & Qualifiers::Volatile);
3240 
3241  return Result.getMethod();
3242 }
3243 
3244 /// Look up the moving assignment operator for the given class.
3246  unsigned Quals,
3247  bool RValueThis,
3248  unsigned ThisQuals) {
3249  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3250  "non-const, non-volatile qualifiers for copy assignment this");
3252  LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3253  Quals & Qualifiers::Volatile, RValueThis,
3254  ThisQuals & Qualifiers::Const,
3255  ThisQuals & Qualifiers::Volatile);
3256 
3257  return Result.getMethod();
3258 }
3259 
3260 /// Look for the destructor of the given class.
3261 ///
3262 /// During semantic analysis, this routine should be used in lieu of
3263 /// CXXRecordDecl::getDestructor().
3264 ///
3265 /// \returns The destructor for this class.
3267  return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3268  false, false, false,
3269  false, false).getMethod());
3270 }
3271 
3272 /// LookupLiteralOperator - Determine which literal operator should be used for
3273 /// a user-defined literal, per C++11 [lex.ext].
3274 ///
3275 /// Normal overload resolution is not used to select which literal operator to
3276 /// call for a user-defined literal. Look up the provided literal operator name,
3277 /// and filter the results to the appropriate set for the given argument types.
3280  ArrayRef<QualType> ArgTys,
3281  bool AllowRaw, bool AllowTemplate,
3282  bool AllowStringTemplate, bool DiagnoseMissing) {
3283  LookupName(R, S);
3284  assert(R.getResultKind() != LookupResult::Ambiguous &&
3285  "literal operator lookup can't be ambiguous");
3286 
3287  // Filter the lookup results appropriately.
3289 
3290  bool FoundRaw = false;
3291  bool FoundTemplate = false;
3292  bool FoundStringTemplate = false;
3293  bool FoundExactMatch = false;
3294 
3295  while (F.hasNext()) {
3296  Decl *D = F.next();
3297  if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3298  D = USD->getTargetDecl();
3299 
3300  // If the declaration we found is invalid, skip it.
3301  if (D->isInvalidDecl()) {
3302  F.erase();
3303  continue;
3304  }
3305 
3306  bool IsRaw = false;
3307  bool IsTemplate = false;
3308  bool IsStringTemplate = false;
3309  bool IsExactMatch = false;
3310 
3311  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3312  if (FD->getNumParams() == 1 &&
3313  FD->getParamDecl(0)->getType()->getAs<PointerType>())
3314  IsRaw = true;
3315  else if (FD->getNumParams() == ArgTys.size()) {
3316  IsExactMatch = true;
3317  for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3318  QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3319  if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3320  IsExactMatch = false;
3321  break;
3322  }
3323  }
3324  }
3325  }
3326  if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3327  TemplateParameterList *Params = FD->getTemplateParameters();
3328  if (Params->size() == 1)
3329  IsTemplate = true;
3330  else
3331  IsStringTemplate = true;
3332  }
3333 
3334  if (IsExactMatch) {
3335  FoundExactMatch = true;
3336  AllowRaw = false;
3337  AllowTemplate = false;
3338  AllowStringTemplate = false;
3339  if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3340  // Go through again and remove the raw and template decls we've
3341  // already found.
3342  F.restart();
3343  FoundRaw = FoundTemplate = FoundStringTemplate = false;
3344  }
3345  } else if (AllowRaw && IsRaw) {
3346  FoundRaw = true;
3347  } else if (AllowTemplate && IsTemplate) {
3348  FoundTemplate = true;
3349  } else if (AllowStringTemplate && IsStringTemplate) {
3350  FoundStringTemplate = true;
3351  } else {
3352  F.erase();
3353  }
3354  }
3355 
3356  F.done();
3357 
3358  // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3359  // parameter type, that is used in preference to a raw literal operator
3360  // or literal operator template.
3361  if (FoundExactMatch)
3362  return LOLR_Cooked;
3363 
3364  // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3365  // operator template, but not both.
3366  if (FoundRaw && FoundTemplate) {
3367  Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3368  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3369  NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3370  return LOLR_Error;
3371  }
3372 
3373  if (FoundRaw)
3374  return LOLR_Raw;
3375 
3376  if (FoundTemplate)
3377  return LOLR_Template;
3378 
3379  if (FoundStringTemplate)
3380  return LOLR_StringTemplate;
3381 
3382  // Didn't find anything we could use.
3383  if (DiagnoseMissing) {
3384  Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3385  << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3386  << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3387  << (AllowTemplate || AllowStringTemplate);
3388  return LOLR_Error;
3389  }
3390 
3391  return LOLR_ErrorNoDiagnostic;
3392 }
3393 
3395  NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3396 
3397  // If we haven't yet seen a decl for this key, or the last decl
3398  // was exactly this one, we're done.
3399  if (Old == nullptr || Old == New) {
3400  Old = New;
3401  return;
3402  }
3403 
3404  // Otherwise, decide which is a more recent redeclaration.
3405  FunctionDecl *OldFD = Old->getAsFunction();
3406  FunctionDecl *NewFD = New->getAsFunction();
3407 
3408  FunctionDecl *Cursor = NewFD;
3409  while (true) {
3410  Cursor = Cursor->getPreviousDecl();
3411 
3412  // If we got to the end without finding OldFD, OldFD is the newer
3413  // declaration; leave things as they are.
3414  if (!Cursor) return;
3415 
3416  // If we do find OldFD, then NewFD is newer.
3417  if (Cursor == OldFD) break;
3418 
3419  // Otherwise, keep looking.
3420  }
3421 
3422  Old = New;
3423 }
3424 
3426  ArrayRef<Expr *> Args, ADLResult &Result) {
3427  // Find all of the associated namespaces and classes based on the
3428  // arguments we have.
3429  AssociatedNamespaceSet AssociatedNamespaces;
3430  AssociatedClassSet AssociatedClasses;
3431  FindAssociatedClassesAndNamespaces(Loc, Args,
3432  AssociatedNamespaces,
3433  AssociatedClasses);
3434 
3435  // C++ [basic.lookup.argdep]p3:
3436  // Let X be the lookup set produced by unqualified lookup (3.4.1)
3437  // and let Y be the lookup set produced by argument dependent
3438  // lookup (defined as follows). If X contains [...] then Y is
3439  // empty. Otherwise Y is the set of declarations found in the
3440  // namespaces associated with the argument types as described
3441  // below. The set of declarations found by the lookup of the name
3442  // is the union of X and Y.
3443  //
3444  // Here, we compute Y and add its members to the overloaded
3445  // candidate set.
3446  for (auto *NS : AssociatedNamespaces) {
3447  // When considering an associated namespace, the lookup is the
3448  // same as the lookup performed when the associated namespace is
3449  // used as a qualifier (3.4.3.2) except that:
3450  //
3451  // -- Any using-directives in the associated namespace are
3452  // ignored.
3453  //
3454  // -- Any namespace-scope friend functions declared in
3455  // associated classes are visible within their respective
3456  // namespaces even if they are not visible during an ordinary
3457  // lookup (11.4).
3458  DeclContext::lookup_result R = NS->lookup(Name);
3459  for (auto *D : R) {
3460  auto *Underlying = D;
3461  if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3462  Underlying = USD->getTargetDecl();
3463 
3464  if (!isa<FunctionDecl>(Underlying) &&
3465  !isa<FunctionTemplateDecl>(Underlying))
3466  continue;
3467 
3468  // The declaration is visible to argument-dependent lookup if either
3469  // it's ordinarily visible or declared as a friend in an associated
3470  // class.
3471  bool Visible = false;
3472  for (D = D->getMostRecentDecl(); D;
3473  D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
3475  if (isVisible(D)) {
3476  Visible = true;
3477  break;
3478  }
3479  } else if (D->getFriendObjectKind()) {
3480  auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
3481  if (AssociatedClasses.count(RD) && isVisible(D)) {
3482  Visible = true;
3483  break;
3484  }
3485  }
3486  }
3487 
3488  // FIXME: Preserve D as the FoundDecl.
3489  if (Visible)
3490  Result.insert(Underlying);
3491  }
3492  }
3493 }
3494 
3495 //----------------------------------------------------------------------------
3496 // Search for all visible declarations.
3497 //----------------------------------------------------------------------------
3499 
3500 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3501 
3502 namespace {
3503 
3504 class ShadowContextRAII;
3505 
3506 class VisibleDeclsRecord {
3507 public:
3508  /// An entry in the shadow map, which is optimized to store a
3509  /// single declaration (the common case) but can also store a list
3510  /// of declarations.
3511  typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3512 
3513 private:
3514  /// A mapping from declaration names to the declarations that have
3515  /// this name within a particular scope.
3516  typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3517 
3518  /// A list of shadow maps, which is used to model name hiding.
3519  std::list<ShadowMap> ShadowMaps;
3520 
3521  /// The declaration contexts we have already visited.
3522  llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3523 
3524  friend class ShadowContextRAII;
3525 
3526 public:
3527  /// Determine whether we have already visited this context
3528  /// (and, if not, note that we are going to visit that context now).
3529  bool visitedContext(DeclContext *Ctx) {
3530  return !VisitedContexts.insert(Ctx).second;
3531  }
3532 
3533  bool alreadyVisitedContext(DeclContext *Ctx) {
3534  return VisitedContexts.count(Ctx);
3535  }
3536 
3537  /// Determine whether the given declaration is hidden in the
3538  /// current scope.
3539  ///
3540  /// \returns the declaration that hides the given declaration, or
3541  /// NULL if no such declaration exists.
3542  NamedDecl *checkHidden(NamedDecl *ND);
3543 
3544  /// Add a declaration to the current shadow map.
3545  void add(NamedDecl *ND) {
3546  ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3547  }
3548 };
3549 
3550 /// RAII object that records when we've entered a shadow context.
3551 class ShadowContextRAII {
3552  VisibleDeclsRecord &Visible;
3553 
3554  typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3555 
3556 public:
3557  ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3558  Visible.ShadowMaps.emplace_back();
3559  }
3560 
3561  ~ShadowContextRAII() {
3562  Visible.ShadowMaps.pop_back();
3563  }
3564 };
3565 
3566 } // end anonymous namespace
3567 
3568 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3569  unsigned IDNS = ND->getIdentifierNamespace();
3570  std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3571  for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3572  SM != SMEnd; ++SM) {
3573  ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3574  if (Pos == SM->end())
3575  continue;
3576 
3577  for (auto *D : Pos->second) {
3578  // A tag declaration does not hide a non-tag declaration.
3579  if (D->hasTagIdentifierNamespace() &&
3582  continue;
3583 
3584  // Protocols are in distinct namespaces from everything else.
3586  || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3587  D->getIdentifierNamespace() != IDNS)
3588  continue;
3589 
3590  // Functions and function templates in the same scope overload
3591  // rather than hide. FIXME: Look for hiding based on function
3592  // signatures!
3595  SM == ShadowMaps.rbegin())
3596  continue;
3597 
3598  // A shadow declaration that's created by a resolved using declaration
3599  // is not hidden by the same using declaration.
3600  if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3601  cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3602  continue;
3603 
3604  // We've found a declaration that hides this one.
3605  return D;
3606  }
3607  }
3608 
3609  return nullptr;
3610 }
3611 
3612 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3613  bool QualifiedNameLookup,
3614  bool InBaseClass,
3615  VisibleDeclConsumer &Consumer,
3616  VisibleDeclsRecord &Visited,
3617  bool IncludeDependentBases,
3618  bool LoadExternal) {
3619  if (!Ctx)
3620  return;
3621 
3622  // Make sure we don't visit the same context twice.
3623  if (Visited.visitedContext(Ctx->getPrimaryContext()))
3624  return;
3625 
3626  Consumer.EnteredContext(Ctx);
3627 
3628  // Outside C++, lookup results for the TU live on identifiers.
3629  if (isa<TranslationUnitDecl>(Ctx) &&
3630  !Result.getSema().getLangOpts().CPlusPlus) {
3631  auto &S = Result.getSema();
3632  auto &Idents = S.Context.Idents;
3633 
3634  // Ensure all external identifiers are in the identifier table.
3635  if (LoadExternal)
3636  if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3637  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3638  for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3639  Idents.get(Name);
3640  }
3641 
3642  // Walk all lookup results in the TU for each identifier.
3643  for (const auto &Ident : Idents) {
3644  for (auto I = S.IdResolver.begin(Ident.getValue()),
3645  E = S.IdResolver.end();
3646  I != E; ++I) {
3647  if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3648  if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3649  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3650  Visited.add(ND);
3651  }
3652  }
3653  }
3654  }
3655 
3656  return;
3657  }
3658 
3659  if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3661 
3662  // We sometimes skip loading namespace-level results (they tend to be huge).
3663  bool Load = LoadExternal ||
3664  !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
3665  // Enumerate all of the results in this context.
3666  for (DeclContextLookupResult R :
3667  Load ? Ctx->lookups()
3668  : Ctx->noload_lookups(/*PreserveInternalState=*/false)) {
3669  for (auto *D : R) {
3670  if (auto *ND = Result.getAcceptableDecl(D)) {
3671  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3672  Visited.add(ND);
3673  }
3674  }
3675  }
3676 
3677  // Traverse using directives for qualified name lookup.
3678  if (QualifiedNameLookup) {
3679  ShadowContextRAII Shadow(Visited);
3680  for (auto I : Ctx->using_directives()) {
3681  if (!Result.getSema().isVisible(I))
3682  continue;
3683  LookupVisibleDecls(I->getNominatedNamespace(), Result,
3684  QualifiedNameLookup, InBaseClass, Consumer, Visited,
3685  IncludeDependentBases, LoadExternal);
3686  }
3687  }
3688 
3689  // Traverse the contexts of inherited C++ classes.
3690  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3691  if (!Record->hasDefinition())
3692  return;
3693 
3694  for (const auto &B : Record->bases()) {
3695  QualType BaseType = B.getType();
3696 
3697  RecordDecl *RD;
3698  if (BaseType->isDependentType()) {
3699  if (!IncludeDependentBases) {
3700  // Don't look into dependent bases, because name lookup can't look
3701  // there anyway.
3702  continue;
3703  }
3704  const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3705  if (!TST)
3706  continue;
3707  TemplateName TN = TST->getTemplateName();
3708  const auto *TD =
3709  dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3710  if (!TD)
3711  continue;
3712  RD = TD->getTemplatedDecl();
3713  } else {
3714  const auto *Record = BaseType->getAs<RecordType>();
3715  if (!Record)
3716  continue;
3717  RD = Record->getDecl();
3718  }
3719 
3720  // FIXME: It would be nice to be able to determine whether referencing
3721  // a particular member would be ambiguous. For example, given
3722  //
3723  // struct A { int member; };
3724  // struct B { int member; };
3725  // struct C : A, B { };
3726  //
3727  // void f(C *c) { c->### }
3728  //
3729  // accessing 'member' would result in an ambiguity. However, we
3730  // could be smart enough to qualify the member with the base
3731  // class, e.g.,
3732  //
3733  // c->B::member
3734  //
3735  // or
3736  //
3737  // c->A::member
3738 
3739  // Find results in this base class (and its bases).
3740  ShadowContextRAII Shadow(Visited);
3741  LookupVisibleDecls(RD, Result, QualifiedNameLookup, /*InBaseClass=*/true,
3742  Consumer, Visited, IncludeDependentBases,
3743  LoadExternal);
3744  }
3745  }
3746 
3747  // Traverse the contexts of Objective-C classes.
3748  if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3749  // Traverse categories.
3750  for (auto *Cat : IFace->visible_categories()) {
3751  ShadowContextRAII Shadow(Visited);
3752  LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false, Consumer,
3753  Visited, IncludeDependentBases, LoadExternal);
3754  }
3755 
3756  // Traverse protocols.
3757  for (auto *I : IFace->all_referenced_protocols()) {
3758  ShadowContextRAII Shadow(Visited);
3759  LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3760  Visited, IncludeDependentBases, LoadExternal);
3761  }
3762 
3763  // Traverse the superclass.
3764  if (IFace->getSuperClass()) {
3765  ShadowContextRAII Shadow(Visited);
3766  LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3767  true, Consumer, Visited, IncludeDependentBases,
3768  LoadExternal);
3769  }
3770 
3771  // If there is an implementation, traverse it. We do this to find
3772  // synthesized ivars.
3773  if (IFace->getImplementation()) {
3774  ShadowContextRAII Shadow(Visited);
3775  LookupVisibleDecls(IFace->getImplementation(), Result,
3776  QualifiedNameLookup, InBaseClass, Consumer, Visited,
3777  IncludeDependentBases, LoadExternal);
3778  }
3779  } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3780  for (auto *I : Protocol->protocols()) {
3781  ShadowContextRAII Shadow(Visited);
3782  LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3783  Visited, IncludeDependentBases, LoadExternal);
3784  }
3785  } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3786  for (auto *I : Category->protocols()) {
3787  ShadowContextRAII Shadow(Visited);
3788  LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3789  Visited, IncludeDependentBases, LoadExternal);
3790  }
3791 
3792  // If there is an implementation, traverse it.
3793  if (Category->getImplementation()) {
3794  ShadowContextRAII Shadow(Visited);
3795  LookupVisibleDecls(Category->getImplementation(), Result,
3796  QualifiedNameLookup, true, Consumer, Visited,
3797  IncludeDependentBases, LoadExternal);
3798  }
3799  }
3800 }
3801 
3802 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3803  UnqualUsingDirectiveSet &UDirs,
3804  VisibleDeclConsumer &Consumer,
3805  VisibleDeclsRecord &Visited,
3806  bool LoadExternal) {
3807  if (!S)
3808  return;
3809 
3810  if (!S->getEntity() ||
3811  (!S->getParent() &&
3812  !Visited.alreadyVisitedContext(S->getEntity())) ||
3813  (S->getEntity())->isFunctionOrMethod()) {
3814  FindLocalExternScope FindLocals(Result);
3815  // Walk through the declarations in this Scope. The consumer might add new
3816  // decls to the scope as part of deserialization, so make a copy first.
3817  SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
3818  for (Decl *D : ScopeDecls) {
3819  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3820  if ((ND = Result.getAcceptableDecl(ND))) {
3821  Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3822  Visited.add(ND);
3823  }
3824  }
3825  }
3826 
3827  // FIXME: C++ [temp.local]p8
3828  DeclContext *Entity = nullptr;
3829  if (S->getEntity()) {
3830  // Look into this scope's declaration context, along with any of its
3831  // parent lookup contexts (e.g., enclosing classes), up to the point
3832  // where we hit the context stored in the next outer scope.
3833  Entity = S->getEntity();
3834  DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3835 
3836  for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3837  Ctx = Ctx->getLookupParent()) {
3838  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3839  if (Method->isInstanceMethod()) {
3840  // For instance methods, look for ivars in the method's interface.
3841  LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3843  if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3844  LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3845  /*InBaseClass=*/false, Consumer, Visited,
3846  /*IncludeDependentBases=*/false, LoadExternal);
3847  }
3848  }
3849 
3850  // We've already performed all of the name lookup that we need
3851  // to for Objective-C methods; the next context will be the
3852  // outer scope.
3853  break;
3854  }
3855 
3856  if (Ctx->isFunctionOrMethod())
3857  continue;
3858 
3859  LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3860  /*InBaseClass=*/false, Consumer, Visited,
3861  /*IncludeDependentBases=*/false, LoadExternal);
3862  }
3863  } else if (!S->getParent()) {
3864  // Look into the translation unit scope. We walk through the translation
3865  // unit's declaration context, because the Scope itself won't have all of
3866  // the declarations if we loaded a precompiled header.
3867  // FIXME: We would like the translation unit's Scope object to point to the
3868  // translation unit, so we don't need this special "if" branch. However,
3869  // doing so would force the normal C++ name-lookup code to look into the
3870  // translation unit decl when the IdentifierInfo chains would suffice.
3871  // Once we fix that problem (which is part of a more general "don't look
3872  // in DeclContexts unless we have to" optimization), we can eliminate this.
3873  Entity = Result.getSema().Context.getTranslationUnitDecl();
3874  LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3875  /*InBaseClass=*/false, Consumer, Visited,
3876  /*IncludeDependentBases=*/false, LoadExternal);
3877  }
3878 
3879  if (Entity) {
3880  // Lookup visible declarations in any namespaces found by using
3881  // directives.
3882  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3883  LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3884  Result, /*QualifiedNameLookup=*/false,
3885  /*InBaseClass=*/false, Consumer, Visited,
3886  /*IncludeDependentBases=*/false, LoadExternal);
3887  }
3888 
3889  // Lookup names in the parent scope.
3890  ShadowContextRAII Shadow(Visited);
3891  LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited,
3892  LoadExternal);
3893 }
3894 
3896  VisibleDeclConsumer &Consumer,
3897  bool IncludeGlobalScope, bool LoadExternal) {
3898  // Determine the set of using directives available during
3899  // unqualified name lookup.
3900  Scope *Initial = S;
3901  UnqualUsingDirectiveSet UDirs(*this);
3902  if (getLangOpts().CPlusPlus) {
3903  // Find the first namespace or translation-unit scope.
3904  while (S && !isNamespaceOrTranslationUnitScope(S))
3905  S = S->getParent();
3906 
3907  UDirs.visitScopeChain(Initial, S);
3908  }
3909  UDirs.done();
3910 
3911  // Look for visible declarations.
3912  LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3913  Result.setAllowHidden(Consumer.includeHiddenDecls());
3914  VisibleDeclsRecord Visited;
3915  if (!IncludeGlobalScope)
3916  Visited.visitedContext(Context.getTranslationUnitDecl());
3917  ShadowContextRAII Shadow(Visited);
3918  ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited, LoadExternal);
3919 }
3920 
3922  VisibleDeclConsumer &Consumer,
3923  bool IncludeGlobalScope,
3924  bool IncludeDependentBases, bool LoadExternal) {
3925  LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3926  Result.setAllowHidden(Consumer.includeHiddenDecls());
3927  VisibleDeclsRecord Visited;
3928  if (!IncludeGlobalScope)
3929  Visited.visitedContext(Context.getTranslationUnitDecl());
3930  ShadowContextRAII Shadow(Visited);
3931  ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3932  /*InBaseClass=*/false, Consumer, Visited,
3933  IncludeDependentBases, LoadExternal);
3934 }
3935 
3936 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3937 /// If GnuLabelLoc is a valid source location, then this is a definition
3938 /// of an __label__ label name, otherwise it is a normal label definition
3939 /// or use.
3941  SourceLocation GnuLabelLoc) {
3942  // Do a lookup to see if we have a label with this name already.
3943  NamedDecl *Res = nullptr;
3944 
3945  if (GnuLabelLoc.isValid()) {
3946  // Local label definitions always shadow existing labels.
3947  Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3948  Scope *S = CurScope;
3949  PushOnScopeChains(Res, S, true);
3950  return cast<LabelDecl>(Res);
3951  }
3952 
3953  // Not a GNU local label.
3954  Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3955  // If we found a label, check to see if it is in the same context as us.
3956  // When in a Block, we don't want to reuse a label in an enclosing function.
3957  if (Res && Res->getDeclContext() != CurContext)
3958  Res = nullptr;
3959  if (!Res) {
3960  // If not forward referenced or defined already, create the backing decl.
3961  Res = LabelDecl::Create(Context, CurContext, Loc, II);
3962  Scope *S = CurScope->getFnParent();
3963  assert(S && "Not in a function?");
3964  PushOnScopeChains(Res, S, true);
3965  }
3966  return cast<LabelDecl>(Res);
3967 }
3968 
3969 //===----------------------------------------------------------------------===//
3970 // Typo correction
3971 //===----------------------------------------------------------------------===//
3972 
3974  TypoCorrection &Candidate) {
3975  Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3976  return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3977 }
3978 
3979 static void LookupPotentialTypoResult(Sema &SemaRef,
3980  LookupResult &Res,
3981  IdentifierInfo *Name,
3982  Scope *S, CXXScopeSpec *SS,
3984  bool EnteringContext,
3985  bool isObjCIvarLookup,
3986  bool FindHidden);
3987 
3988 /// Check whether the declarations found for a typo correction are
3989 /// visible. Set the correction's RequiresImport flag to true if none of the
3990 /// declarations are visible, false otherwise.
3991 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3992  TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3993 
3994  for (/**/; DI != DE; ++DI)
3995  if (!LookupResult::isVisible(SemaRef, *DI))
3996  break;
3997  // No filtering needed if all decls are visible.
3998  if (DI == DE) {
3999  TC.setRequiresImport(false);
4000  return;
4001  }
4002 
4003  llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4004  bool AnyVisibleDecls = !NewDecls.empty();
4005 
4006  for (/**/; DI != DE; ++DI) {
4007  if (LookupResult::isVisible(SemaRef, *DI)) {
4008  if (!AnyVisibleDecls) {
4009  // Found a visible decl, discard all hidden ones.
4010  AnyVisibleDecls = true;
4011  NewDecls.clear();
4012  }
4013  NewDecls.push_back(*DI);
4014  } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4015  NewDecls.push_back(*DI);
4016  }
4017 
4018  if (NewDecls.empty())
4019  TC = TypoCorrection();
4020  else {
4021  TC.setCorrectionDecls(NewDecls);
4022  TC.setRequiresImport(!AnyVisibleDecls);
4023  }
4024 }
4025 
4026 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
4027 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4028 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4030  NestedNameSpecifier *NNS,
4032  if (NestedNameSpecifier *Prefix = NNS->getPrefix())
4033  getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
4034  else
4035  Identifiers.clear();
4036 
4037  const IdentifierInfo *II = nullptr;
4038 
4039  switch (NNS->getKind()) {
4041  II = NNS->getAsIdentifier();
4042  break;
4043 
4045  if (NNS->getAsNamespace()->isAnonymousNamespace())
4046  return;
4047  II = NNS->getAsNamespace()->getIdentifier();
4048  break;
4049 
4051  II = NNS->getAsNamespaceAlias()->getIdentifier();
4052  break;
4053 
4056  II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
4057  break;
4058 
4061  return;
4062  }
4063 
4064  if (II)
4065  Identifiers.push_back(II);
4066 }
4067 
4069  DeclContext *Ctx, bool InBaseClass) {
4070  // Don't consider hidden names for typo correction.
4071  if (Hiding)
4072  return;
4073 
4074  // Only consider entities with identifiers for names, ignoring
4075  // special names (constructors, overloaded operators, selectors,
4076  // etc.).
4077  IdentifierInfo *Name = ND->getIdentifier();
4078  if (!Name)
4079  return;
4080 
4081  // Only consider visible declarations and declarations from modules with
4082  // names that exactly match.
4083  if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
4084  return;
4085 
4086  FoundName(Name->getName());
4087 }
4088 
4090  // Compute the edit distance between the typo and the name of this
4091  // entity, and add the identifier to the list of results.
4092  addName(Name, nullptr);
4093 }
4094 
4096  // Compute the edit distance between the typo and this keyword,
4097  // and add the keyword to the list of results.
4098  addName(Keyword, nullptr, nullptr, true);
4099 }
4100 
4101 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4102  NestedNameSpecifier *NNS, bool isKeyword) {
4103  // Use a simple length-based heuristic to determine the minimum possible
4104  // edit distance. If the minimum isn't good enough, bail out early.
4105  StringRef TypoStr = Typo->getName();
4106  unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
4107  if (MinED && TypoStr.size() / MinED < 3)
4108  return;
4109 
4110  // Compute an upper bound on the allowable edit distance, so that the
4111  // edit-distance algorithm can short-circuit.
4112  unsigned UpperBound = (TypoStr.size() + 2) / 3;
4113  unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
4114  if (ED > UpperBound) return;
4115 
4116  TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4117  if (isKeyword) TC.makeKeyword();
4118  TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
4119  addCorrection(TC);
4120 }
4121 
4122 static const unsigned MaxTypoDistanceResultSets = 5;
4123 
4125  StringRef TypoStr = Typo->getName();
4126  StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4127 
4128  // For very short typos, ignore potential corrections that have a different
4129  // base identifier from the typo or which have a normalized edit distance
4130  // longer than the typo itself.
4131  if (TypoStr.size() < 3 &&
4132  (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4133  return;
4134 
4135  // If the correction is resolved but is not viable, ignore it.
4136  if (Correction.isResolved()) {
4137  checkCorrectionVisibility(SemaRef, Correction);
4138  if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4139  return;
4140  }
4141 
4142  TypoResultList &CList =
4143  CorrectionResults[Correction.getEditDistance(false)][Name];
4144 
4145  if (!CList.empty() && !CList.back().isResolved())
4146  CList.pop_back();
4147  if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4148  std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4149  for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4150  RI != RIEnd; ++RI) {
4151  // If the Correction refers to a decl already in the result list,
4152  // replace the existing result if the string representation of Correction
4153  // comes before the current result alphabetically, then stop as there is
4154  // nothing more to be done to add Correction to the candidate set.
4155  if (RI->getCorrectionDecl() == NewND) {
4156  if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4157  *RI = Correction;
4158  return;
4159  }
4160  }
4161  }
4162  if (CList.empty() || Correction.isResolved())
4163  CList.push_back(Correction);
4164 
4165  while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4166  CorrectionResults.erase(std::prev(CorrectionResults.end()));
4167 }
4168 
4170  const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4171  SearchNamespaces = true;
4172 
4173  for (auto KNPair : KnownNamespaces)
4174  Namespaces.addNameSpecifier(KNPair.first);
4175 
4176  bool SSIsTemplate = false;
4177  if (NestedNameSpecifier *NNS =
4178  (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4179  if (const Type *T = NNS->getAsType())
4180  SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4181  }
4182  // Do not transform this into an iterator-based loop. The loop body can
4183  // trigger the creation of further types (through lazy deserialization) and
4184  // invalid iterators into this list.
4185  auto &Types = SemaRef.getASTContext().getTypes();
4186  for (unsigned I = 0; I != Types.size(); ++I) {
4187  const auto *TI = Types[I];
4188  if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4189  CD = CD->getCanonicalDecl();
4190  if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4191  !CD->isUnion() && CD->getIdentifier() &&
4192  (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4193  (CD->isBeingDefined() || CD->isCompleteDefinition()))
4194  Namespaces.addNameSpecifier(CD);
4195  }
4196  }
4197 }
4198 
4200  if (++CurrentTCIndex < ValidatedCorrections.size())
4201  return ValidatedCorrections[CurrentTCIndex];
4202 
4203  CurrentTCIndex = ValidatedCorrections.size();
4204  while (!CorrectionResults.empty()) {
4205  auto DI = CorrectionResults.begin();
4206  if (DI->second.empty()) {
4207  CorrectionResults.erase(DI);
4208  continue;
4209  }
4210 
4211  auto RI = DI->second.begin();
4212  if (RI->second.empty()) {
4213  DI->second.erase(RI);
4214  performQualifiedLookups();
4215  continue;
4216  }
4217 
4218  TypoCorrection TC = RI->second.pop_back_val();
4219  if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4220  ValidatedCorrections.push_back(TC);
4221  return ValidatedCorrections[CurrentTCIndex];
4222  }
4223  }
4224  return ValidatedCorrections[0]; // The empty correction.
4225 }
4226 
4227 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4228  IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4229  DeclContext *TempMemberContext = MemberContext;
4230  CXXScopeSpec *TempSS = SS.get();
4231 retry_lookup:
4232  LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4233  EnteringContext,
4234  CorrectionValidator->IsObjCIvarLookup,
4235  Name == Typo && !Candidate.WillReplaceSpecifier());
4236  switch (Result.getResultKind()) {
4240  if (TempSS) {
4241  // Immediately retry the lookup without the given CXXScopeSpec
4242  TempSS = nullptr;
4243  Candidate.WillReplaceSpecifier(true);
4244  goto retry_lookup;
4245  }
4246  if (TempMemberContext) {
4247  if (SS && !TempSS)
4248  TempSS = SS.get();
4249  TempMemberContext = nullptr;
4250  goto retry_lookup;
4251  }
4252  if (SearchNamespaces)
4253  QualifiedResults.push_back(Candidate);
4254  break;
4255 
4257  // We don't deal with ambiguities.
4258  break;
4259 
4260  case LookupResult::Found:
4262  // Store all of the Decls for overloaded symbols
4263  for (auto *TRD : Result)
4264  Candidate.addCorrectionDecl(TRD);
4265  checkCorrectionVisibility(SemaRef, Candidate);
4266  if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4267  if (SearchNamespaces)
4268  QualifiedResults.push_back(Candidate);
4269  break;
4270  }
4271  Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4272  return true;
4273  }
4274  return false;
4275 }
4276 
4277 void TypoCorrectionConsumer::performQualifiedLookups() {
4278  unsigned TypoLen = Typo->getName().size();
4279  for (const TypoCorrection &QR : QualifiedResults) {
4280  for (const auto &NSI : Namespaces) {
4281  DeclContext *Ctx = NSI.DeclCtx;
4282  const Type *NSType = NSI.NameSpecifier->getAsType();
4283 
4284  // If the current NestedNameSpecifier refers to a class and the
4285  // current correction candidate is the name of that class, then skip
4286  // it as it is unlikely a qualified version of the class' constructor
4287  // is an appropriate correction.
4288  if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4289  nullptr) {
4290  if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4291  continue;
4292  }
4293 
4294  TypoCorrection TC(QR);
4295  TC.ClearCorrectionDecls();
4296  TC.setCorrectionSpecifier(NSI.NameSpecifier);
4297  TC.setQualifierDistance(NSI.EditDistance);
4298  TC.setCallbackDistance(0); // Reset the callback distance
4299 
4300  // If the current correction candidate and namespace combination are
4301  // too far away from the original typo based on the normalized edit
4302  // distance, then skip performing a qualified name lookup.
4303  unsigned TmpED = TC.getEditDistance(true);
4304  if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4305  TypoLen / TmpED < 3)
4306  continue;
4307 
4308  Result.clear();
4309  Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4310  if (!SemaRef.LookupQualifiedName(Result, Ctx))
4311  continue;
4312 
4313  // Any corrections added below will be validated in subsequent
4314  // iterations of the main while() loop over the Consumer's contents.
4315  switch (Result.getResultKind()) {
4316  case LookupResult::Found:
4318  if (SS && SS->isValid()) {
4319  std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4320  std::string OldQualified;
4321  llvm::raw_string_ostream OldOStream(OldQualified);
4322  SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4323  OldOStream << Typo->getName();
4324  // If correction candidate would be an identical written qualified
4325  // identifier, then the existing CXXScopeSpec probably included a
4326  // typedef that didn't get accounted for properly.
4327  if (OldOStream.str() == NewQualified)
4328  break;
4329  }
4330  for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4331  TRD != TRDEnd; ++TRD) {
4332  if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4333  NSType ? NSType->getAsCXXRecordDecl()
4334  : nullptr,
4335  TRD.getPair()) == Sema::AR_accessible)
4336  TC.addCorrectionDecl(*TRD);
4337  }
4338  if (TC.isResolved()) {
4339  TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4340  addCorrection(TC);
4341  }
4342  break;
4343  }
4348  break;
4349  }
4350  }
4351  }
4352  QualifiedResults.clear();
4353 }
4354 
4355 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4356  ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4357  : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4358  if (NestedNameSpecifier *NNS =
4359  CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4360  llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4361  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4362 
4363  getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4364  }
4365  // Build the list of identifiers that would be used for an absolute
4366  // (from the global context) NestedNameSpecifier referring to the current
4367  // context.
4368  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4369  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4370  CurContextIdentifiers.push_back(ND->getIdentifier());
4371  }
4372 
4373  // Add the global context as a NestedNameSpecifier
4374  SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4376  DistanceMap[1].push_back(SI);
4377 }
4378 
4379 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4380  DeclContext *Start) -> DeclContextList {
4381  assert(Start && "Building a context chain from a null context");
4382  DeclContextList Chain;
4383  for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4384  DC = DC->getLookupParent()) {
4385  NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4386  if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4387  !(ND && ND->isAnonymousNamespace()))
4388  Chain.push_back(DC->getPrimaryContext());
4389  }
4390  return Chain;
4391 }
4392 
4393 unsigned
4394 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4395  DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4396  unsigned NumSpecifiers = 0;
4397  for (DeclContext *C : llvm::reverse(DeclChain)) {
4398  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4399  NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4400  ++NumSpecifiers;
4401  } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4402  NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4403  RD->getTypeForDecl());
4404  ++NumSpecifiers;
4405  }
4406  }
4407  return NumSpecifiers;
4408 }
4409 
4410 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4411  DeclContext *Ctx) {
4412  NestedNameSpecifier *NNS = nullptr;
4413  unsigned NumSpecifiers = 0;
4414  DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4415  DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4416 
4417  // Eliminate common elements from the two DeclContext chains.
4418  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4419  if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4420  break;
4421  NamespaceDeclChain.pop_back();
4422  }
4423 
4424  // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4425  NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4426 
4427  // Add an explicit leading '::' specifier if needed.
4428  if (NamespaceDeclChain.empty()) {
4429  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4430  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4431  NumSpecifiers =
4432  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4433  } else if (NamedDecl *ND =
4434  dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4435  IdentifierInfo *Name = ND->getIdentifier();
4436  bool SameNameSpecifier = false;
4437  if (std::find(CurNameSpecifierIdentifiers.begin(),
4438  CurNameSpecifierIdentifiers.end(),
4439  Name) != CurNameSpecifierIdentifiers.end()) {
4440  std::string NewNameSpecifier;
4441  llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4442  SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4443  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4444  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4445  SpecifierOStream.flush();
4446  SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4447  }
4448  if (SameNameSpecifier || llvm::find(CurContextIdentifiers, Name) !=
4449  CurContextIdentifiers.end()) {
4450  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4451  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4452  NumSpecifiers =
4453  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4454  }
4455  }
4456 
4457  // If the built NestedNameSpecifier would be replacing an existing
4458  // NestedNameSpecifier, use the number of component identifiers that
4459  // would need to be changed as the edit distance instead of the number
4460  // of components in the built NestedNameSpecifier.
4461  if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4462  SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4463  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4464  NumSpecifiers = llvm::ComputeEditDistance(
4465  llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4466  llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4467  }
4468 
4469  SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4470  DistanceMap[NumSpecifiers].push_back(SI);
4471 }
4472 
4473 /// Perform name lookup for a possible result for typo correction.
4474 static void LookupPotentialTypoResult(Sema &SemaRef,
4475  LookupResult &Res,
4476  IdentifierInfo *Name,
4477  Scope *S, CXXScopeSpec *SS,
4478  DeclContext *MemberContext,
4479  bool EnteringContext,
4480  bool isObjCIvarLookup,
4481  bool FindHidden) {
4482  Res.suppressDiagnostics();
4483  Res.clear();
4484  Res.setLookupName(Name);
4485  Res.setAllowHidden(FindHidden);
4486  if (MemberContext) {
4487  if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4488  if (isObjCIvarLookup) {
4489  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4490  Res.addDecl(Ivar);
4491  Res.resolveKind();
4492  return;
4493  }
4494  }
4495 
4496  if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4498  Res.addDecl(Prop);
4499  Res.resolveKind();
4500  return;
4501  }
4502  }
4503 
4504  SemaRef.LookupQualifiedName(Res, MemberContext);
4505  return;
4506  }
4507 
4508  SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4509  EnteringContext);
4510 
4511  // Fake ivar lookup; this should really be part of
4512  // LookupParsedName.
4513  if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4514  if (Method->isInstanceMethod() && Method->getClassInterface() &&
4515  (Res.empty() ||
4516  (Res.isSingleResult() &&
4518  if (ObjCIvarDecl *IV
4519  = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4520  Res.addDecl(IV);
4521  Res.resolveKind();
4522  }
4523  }
4524  }
4525 }
4526 
4527 /// Add keywords to the consumer as possible typo corrections.
4528 static void AddKeywordsToConsumer(Sema &SemaRef,
4529  TypoCorrectionConsumer &Consumer,
4531  bool AfterNestedNameSpecifier) {
4532  if (AfterNestedNameSpecifier) {
4533  // For 'X::', we know exactly which keywords can appear next.
4534  Consumer.addKeywordResult("template");
4535  if (CCC.WantExpressionKeywords)
4536  Consumer.addKeywordResult("operator");
4537  return;
4538  }
4539 
4540  if (CCC.WantObjCSuper)
4541  Consumer.addKeywordResult("super");
4542 
4543  if (CCC.WantTypeSpecifiers) {
4544  // Add type-specifier keywords to the set of results.
4545  static const char *const CTypeSpecs[] = {
4546  "char", "const", "double", "enum", "float", "int", "long", "short",
4547  "signed", "struct", "union", "unsigned", "void", "volatile",
4548  "_Complex", "_Imaginary",
4549  // storage-specifiers as well
4550  "extern", "inline", "static", "typedef"
4551  };
4552 
4553  const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4554  for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4555  Consumer.addKeywordResult(CTypeSpecs[I]);
4556 
4557  if (SemaRef.getLangOpts().C99)
4558  Consumer.addKeywordResult("restrict");
4559  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4560  Consumer.addKeywordResult("bool");
4561  else if (SemaRef.getLangOpts().C99)
4562  Consumer.addKeywordResult("_Bool");
4563 
4564  if (SemaRef.getLangOpts().CPlusPlus) {
4565  Consumer.addKeywordResult("class");
4566  Consumer.addKeywordResult("typename");
4567  Consumer.addKeywordResult("wchar_t");
4568 
4569  if (SemaRef.getLangOpts().CPlusPlus11) {
4570  Consumer.addKeywordResult("char16_t");
4571  Consumer.addKeywordResult("char32_t");
4572  Consumer.addKeywordResult("constexpr");
4573  Consumer.addKeywordResult("decltype");
4574  Consumer.addKeywordResult("thread_local");
4575  }
4576  }
4577 
4578  if (SemaRef.getLangOpts().GNUKeywords)
4579  Consumer.addKeywordResult("typeof");
4580  } else if (CCC.WantFunctionLikeCasts) {
4581  static const char *const CastableTypeSpecs[] = {
4582  "char", "double", "float", "int", "long", "short",
4583  "signed", "unsigned", "void"
4584  };
4585  for (auto *kw : CastableTypeSpecs)
4586  Consumer.addKeywordResult(kw);
4587  }
4588 
4589  if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4590  Consumer.addKeywordResult("const_cast");
4591  Consumer.addKeywordResult("dynamic_cast");
4592  Consumer.addKeywordResult("reinterpret_cast");
4593  Consumer.addKeywordResult("static_cast");
4594  }
4595 
4596  if (CCC.WantExpressionKeywords) {
4597  Consumer.addKeywordResult("sizeof");
4598  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4599  Consumer.addKeywordResult("false");
4600  Consumer.addKeywordResult("true");
4601  }
4602 
4603  if (SemaRef.getLangOpts().CPlusPlus) {
4604  static const char *const CXXExprs[] = {
4605  "delete", "new", "operator", "throw", "typeid"
4606  };
4607  const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4608  for (unsigned I = 0; I != NumCXXExprs; ++I)
4609  Consumer.addKeywordResult(CXXExprs[I]);
4610 
4611  if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4612  cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4613  Consumer.addKeywordResult("this");
4614 
4615  if (SemaRef.getLangOpts().CPlusPlus11) {
4616  Consumer.addKeywordResult("alignof");
4617  Consumer.addKeywordResult("nullptr");
4618  }
4619  }
4620 
4621  if (SemaRef.getLangOpts().C11) {
4622  // FIXME: We should not suggest _Alignof if the alignof macro
4623  // is present.
4624  Consumer.addKeywordResult("_Alignof");
4625  }
4626  }
4627 
4628  if (CCC.WantRemainingKeywords) {
4629  if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4630  // Statements.
4631  static const char *const CStmts[] = {
4632  "do", "else", "for", "goto", "if", "return", "switch", "while" };
4633  const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4634  for (unsigned I = 0; I != NumCStmts; ++I)
4635  Consumer.addKeywordResult(CStmts[I]);
4636 
4637  if (SemaRef.getLangOpts().CPlusPlus) {
4638  Consumer.addKeywordResult("catch");
4639  Consumer.addKeywordResult("try");
4640  }
4641 
4642  if (S && S->getBreakParent())
4643  Consumer.addKeywordResult("break");
4644 
4645  if (S && S->getContinueParent())
4646  Consumer.addKeywordResult("continue");
4647 
4648  if (SemaRef.getCurFunction() &&
4649  !SemaRef.getCurFunction()->SwitchStack.empty()) {
4650  Consumer.addKeywordResult("case");
4651  Consumer.addKeywordResult("default");
4652  }
4653  } else {
4654  if (SemaRef.getLangOpts().CPlusPlus) {
4655  Consumer.addKeywordResult("namespace");
4656  Consumer.addKeywordResult("template");
4657  }
4658 
4659  if (S && S->isClassScope()) {
4660  Consumer.addKeywordResult("explicit");
4661  Consumer.addKeywordResult("friend");
4662  Consumer.addKeywordResult("mutable");
4663  Consumer.addKeywordResult("private");
4664  Consumer.addKeywordResult("protected");
4665  Consumer.addKeywordResult("public");
4666  Consumer.addKeywordResult("virtual");
4667  }
4668  }
4669 
4670  if (SemaRef.getLangOpts().CPlusPlus) {
4671  Consumer.addKeywordResult("using");
4672 
4673  if (SemaRef.getLangOpts().CPlusPlus11)
4674  Consumer.addKeywordResult("static_assert");
4675  }
4676  }
4677 }
4678 
4679 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4680  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4682  DeclContext *MemberContext, bool EnteringContext,
4683  const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4684 
4685  if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4686  DisableTypoCorrection)
4687  return nullptr;
4688 
4689  // In Microsoft mode, don't perform typo correction in a template member
4690  // function dependent context because it interferes with the "lookup into
4691  // dependent bases of class templates" feature.
4692  if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4693  isa<CXXMethodDecl>(CurContext))
4694  return nullptr;
4695 
4696  // We only attempt to correct typos for identifiers.
4697  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4698  if (!Typo)
4699  return nullptr;
4700 
4701  // If the scope specifier itself was invalid, don't try to correct
4702  // typos.
4703  if (SS && SS->isInvalid())
4704  return nullptr;
4705 
4706  // Never try to correct typos during any kind of code synthesis.
4707  if (!CodeSynthesisContexts.empty())
4708  return nullptr;
4709 
4710  // Don't try to correct 'super'.
4711  if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4712  return nullptr;
4713 
4714  // Abort if typo correction already failed for this specific typo.
4715  IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4716  if (locs != TypoCorrectionFailures.end() &&
4717  locs->second.count(TypoName.getLoc()))
4718  return nullptr;
4719 
4720  // Don't try to correct the identifier "vector" when in AltiVec mode.
4721  // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4722  // remove this workaround.
4723  if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4724  return nullptr;
4725 
4726  // Provide a stop gap for files that are just seriously broken. Trying
4727  // to correct all typos can turn into a HUGE performance penalty, causing
4728  // some files to take minutes to get rejected by the parser.
4729  unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4730  if (Limit && TyposCorrected >= Limit)
4731  return nullptr;
4732  ++TyposCorrected;
4733 
4734  // If we're handling a missing symbol error, using modules, and the
4735  // special search all modules option is used, look for a missing import.
4736  if (ErrorRecovery && getLangOpts().Modules &&
4737  getLangOpts().ModulesSearchAll) {
4738  // The following has the side effect of loading the missing module.
4739  getModuleLoader().lookupMissingImports(Typo->getName(),
4740  TypoName.getBeginLoc());
4741  }
4742 
4743  // Extend the lifetime of the callback. We delayed this until here
4744  // to avoid allocations in the hot path (which is where no typo correction
4745  // occurs). Note that CorrectionCandidateCallback is polymorphic and
4746  // initially stack-allocated.
4747  std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
4748  auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4749  *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext,
4750  EnteringContext);
4751 
4752  // Perform name lookup to find visible, similarly-named entities.
4753  bool IsUnqualifiedLookup = false;
4754  DeclContext *QualifiedDC = MemberContext;
4755  if (MemberContext) {
4756  LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4757 
4758  // Look in qualified interfaces.
4759  if (OPT) {
4760  for (auto *I : OPT->quals())
4761  LookupVisibleDecls(I, LookupKind, *Consumer);
4762  }
4763  } else if (SS && SS->isSet()) {
4764  QualifiedDC = computeDeclContext(*SS, EnteringContext);
4765  if (!QualifiedDC)
4766  return nullptr;
4767 
4768  LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4769  } else {
4770  IsUnqualifiedLookup = true;
4771  }
4772 
4773  // Determine whether we are going to search in the various namespaces for
4774  // corrections.
4775  bool SearchNamespaces
4776  = getLangOpts().CPlusPlus &&
4777  (IsUnqualifiedLookup || (SS && SS->isSet()));
4778 
4779  if (IsUnqualifiedLookup || SearchNamespaces) {
4780  // For unqualified lookup, look through all of the names that we have
4781  // seen in this translation unit.
4782  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4783  for (const auto &I : Context.Idents)
4784  Consumer->FoundName(I.getKey());
4785 
4786  // Walk through identifiers in external identifier sources.
4787  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4788  if (IdentifierInfoLookup *External
4789  = Context.Idents.getExternalIdentifierLookup()) {
4790  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4791  do {
4792  StringRef Name = Iter->Next();
4793  if (Name.empty())
4794  break;
4795 
4796  Consumer->FoundName(Name);
4797  } while (true);
4798  }
4799  }
4800 
4801  AddKeywordsToConsumer(*this, *Consumer, S,
4802  *Consumer->getCorrectionValidator(),
4803  SS && SS->isNotEmpty());
4804 
4805  // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4806  // to search those namespaces.
4807  if (SearchNamespaces) {
4808  // Load any externally-known namespaces.
4809  if (ExternalSource && !LoadedExternalKnownNamespaces) {
4810  SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4811  LoadedExternalKnownNamespaces = true;
4812  ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4813  for (auto *N : ExternalKnownNamespaces)
4814  KnownNamespaces[N] = true;
4815  }
4816 
4817  Consumer->addNamespaces(KnownNamespaces);
4818  }
4819 
4820  return Consumer;
4821 }
4822 
4823 /// Try to "correct" a typo in the source code by finding
4824 /// visible declarations whose names are similar to the name that was
4825 /// present in the source code.
4826 ///
4827 /// \param TypoName the \c DeclarationNameInfo structure that contains
4828 /// the name that was present in the source code along with its location.
4829 ///
4830 /// \param LookupKind the name-lookup criteria used to search for the name.
4831 ///
4832 /// \param S the scope in which name lookup occurs.
4833 ///
4834 /// \param SS the nested-name-specifier that precedes the name we're
4835 /// looking for, if present.
4836 ///
4837 /// \param CCC A CorrectionCandidateCallback object that provides further
4838 /// validation of typo correction candidates. It also provides flags for
4839 /// determining the set of keywords permitted.
4840 ///
4841 /// \param MemberContext if non-NULL, the context in which to look for
4842 /// a member access expression.
4843 ///
4844 /// \param EnteringContext whether we're entering the context described by
4845 /// the nested-name-specifier SS.
4846 ///
4847 /// \param OPT when non-NULL, the search for visible declarations will
4848 /// also walk the protocols in the qualified interfaces of \p OPT.
4849 ///
4850 /// \returns a \c TypoCorrection containing the corrected name if the typo
4851 /// along with information such as the \c NamedDecl where the corrected name
4852 /// was declared, and any additional \c NestedNameSpecifier needed to access
4853 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4855  Sema::LookupNameKind LookupKind,
4856  Scope *S, CXXScopeSpec *SS,
4858  CorrectTypoKind Mode,
4859  DeclContext *MemberContext,
4860  bool EnteringContext,
4861  const ObjCObjectPointerType *OPT,
4862  bool RecordFailure) {
4863  // Always let the ExternalSource have the first chance at correction, even
4864  // if we would otherwise have given up.
4865  if (ExternalSource) {
4866  if (TypoCorrection Correction =
4867  ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC,
4868  MemberContext, EnteringContext, OPT))
4869  return Correction;
4870  }
4871 
4872  // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4873  // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4874  // some instances of CTC_Unknown, while WantRemainingKeywords is true
4875  // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4876  bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
4877 
4878  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4879  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
4880  MemberContext, EnteringContext,
4881  OPT, Mode == CTK_ErrorRecovery);
4882 
4883  if (!Consumer)
4884  return TypoCorrection();
4885 
4886  // If we haven't found anything, we're done.
4887  if (Consumer->empty())
4888  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4889 
4890  // Make sure the best edit distance (prior to adding any namespace qualifiers)
4891  // is not more that about a third of the length of the typo's identifier.
4892  unsigned ED = Consumer->getBestEditDistance(true);
4893  unsigned TypoLen = Typo->getName().size();
4894  if (ED > 0 && TypoLen / ED < 3)
4895  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4896 
4897  TypoCorrection BestTC = Consumer->getNextCorrection();
4898  TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4899  if (!BestTC)
4900  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4901 
4902  ED = BestTC.getEditDistance();
4903 
4904  if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4905  // If this was an unqualified lookup and we believe the callback
4906  // object wouldn't have filtered out possible corrections, note
4907  // that no correction was found.
4908  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4909  }
4910 
4911  // If only a single name remains, return that result.
4912  if (!SecondBestTC ||
4913  SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4914  const TypoCorrection &Result = BestTC;
4915 
4916  // Don't correct to a keyword that's the same as the typo; the keyword
4917  // wasn't actually in scope.
4918  if (ED == 0 && Result.isKeyword())
4919  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4920 
4921  TypoCorrection TC = Result;
4922  TC.setCorrectionRange(SS, TypoName);
4923  checkCorrectionVisibility(*this, TC);
4924  return TC;
4925  } else if (SecondBestTC && ObjCMessageReceiver) {
4926  // Prefer 'super' when we're completing in a message-receiver
4927  // context.
4928 
4929  if (BestTC.getCorrection().getAsString() != "super") {
4930  if (SecondBestTC.getCorrection().getAsString() == "super")
4931  BestTC = SecondBestTC;
4932  else if ((*Consumer)["super"].front().isKeyword())
4933  BestTC = (*Consumer)["super"].front();
4934  }
4935  // Don't correct to a keyword that's the same as the typo; the keyword
4936  // wasn't actually in scope.
4937  if (BestTC.getEditDistance() == 0 ||
4938  BestTC.getCorrection().getAsString() != "super")
4939  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4940 
4941  BestTC.setCorrectionRange(SS, TypoName);
4942  return BestTC;
4943  }
4944 
4945  // Record the failure's location if needed and return an empty correction. If
4946  // this was an unqualified lookup and we believe the callback object did not
4947  // filter out possible corrections, also cache the failure for the typo.
4948  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4949 }
4950 
4951 /// Try to "correct" a typo in the source code by finding
4952 /// visible declarations whose names are similar to the name that was
4953 /// present in the source code.
4954 ///
4955 /// \param TypoName the \c DeclarationNameInfo structure that contains
4956 /// the name that was present in the source code along with its location.
4957 ///
4958 /// \param LookupKind the name-lookup criteria used to search for the name.
4959 ///
4960 /// \param S the scope in which name lookup occurs.
4961 ///
4962 /// \param SS the nested-name-specifier that precedes the name we're
4963 /// looking for, if present.
4964 ///
4965 /// \param CCC A CorrectionCandidateCallback object that provides further
4966 /// validation of typo correction candidates. It also provides flags for
4967 /// determining the set of keywords permitted.
4968 ///
4969 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4970 /// diagnostics when the actual typo correction is attempted.
4971 ///
4972 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4973 /// Expr from a typo correction candidate.
4974 ///
4975 /// \param MemberContext if non-NULL, the context in which to look for
4976 /// a member access expression.
4977 ///
4978 /// \param EnteringContext whether we're entering the context described by
4979 /// the nested-name-specifier SS.
4980 ///
4981 /// \param OPT when non-NULL, the search for visible declarations will
4982 /// also walk the protocols in the qualified interfaces of \p OPT.
4983 ///
4984 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4985 /// Expr representing the result of performing typo correction, or nullptr if
4986 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4987 /// be emitted and it is the responsibility of the caller to emit any that are
4988 /// needed.
4990  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4993  DeclContext *MemberContext, bool EnteringContext,
4994  const ObjCObjectPointerType *OPT) {
4995  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
4996  MemberContext, EnteringContext,
4997  OPT, Mode == CTK_ErrorRecovery);
4998 
4999  // Give the external sema source a chance to correct the typo.
5000  TypoCorrection ExternalTypo;
5001  if (ExternalSource && Consumer) {
5002  ExternalTypo = ExternalSource->CorrectTypo(
5003  TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
5004  MemberContext, EnteringContext, OPT);
5005  if (ExternalTypo)
5006  Consumer->addCorrection(ExternalTypo);
5007  }
5008 
5009  if (!Consumer || Consumer->empty())
5010  return nullptr;
5011 
5012  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5013  // is not more that about a third of the length of the typo's identifier.
5014  unsigned ED = Consumer->getBestEditDistance(true);
5015  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5016  if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
5017  return nullptr;
5018 
5019  ExprEvalContexts.back().NumTypos++;
5020  return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
5021 }
5022 
5024  if (!CDecl) return;
5025 
5026  if (isKeyword())
5027  CorrectionDecls.clear();
5028 
5029  CorrectionDecls.push_back(CDecl);
5030 
5031  if (!CorrectionName)
5032  CorrectionName = CDecl->getDeclName();
5033 }
5034 
5035 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
5036  if (CorrectionNameSpec) {
5037  std::string tmpBuffer;
5038  llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5039  CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
5040  PrefixOStream << CorrectionName;
5041  return PrefixOStream.str();
5042  }
5043 
5044  return CorrectionName.getAsString();
5045 }
5046 
5048  const TypoCorrection &candidate) {
5049  if (!candidate.isResolved())
5050  return true;
5051 
5052  if (candidate.isKeyword())
5053  return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
5054  WantRemainingKeywords || WantObjCSuper;
5055 
5056  bool HasNonType = false;
5057  bool HasStaticMethod = false;
5058  bool HasNonStaticMethod = false;
5059  for (Decl *D : candidate) {
5060  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
5061  D = FTD->getTemplatedDecl();
5062  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
5063  if (Method->isStatic())
5064  HasStaticMethod = true;
5065  else
5066  HasNonStaticMethod = true;
5067  }
5068  if (!isa<TypeDecl>(D))
5069  HasNonType = true;
5070  }
5071 
5072  if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5073  !candidate.getCorrectionSpecifier())
5074  return false;
5075 
5076  return WantTypeSpecifiers || HasNonType;
5077 }
5078 
5080  bool HasExplicitTemplateArgs,
5081  MemberExpr *ME)
5082  : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5083  CurContext(SemaRef.CurContext), MemberFn(ME) {
5084  WantTypeSpecifiers = false;
5085  WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5086  !HasExplicitTemplateArgs && NumArgs == 1;
5087  WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5088  WantRemainingKeywords = false;
5089 }
5090 
5092  if (!candidate.getCorrectionDecl())
5093  return candidate.isKeyword();
5094 
5095  for (auto *C : candidate) {
5096  FunctionDecl *FD = nullptr;
5097  NamedDecl *ND = C->getUnderlyingDecl();
5098  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
5099  FD = FTD->getTemplatedDecl();
5100  if (!HasExplicitTemplateArgs && !FD) {
5101  if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
5102  // If the Decl is neither a function nor a template function,
5103  // determine if it is a pointer or reference to a function. If so,
5104  // check against the number of arguments expected for the pointee.
5105  QualType ValType = cast<ValueDecl>(ND)->getType();
5106  if (ValType.isNull())
5107  continue;
5108  if (ValType->isAnyPointerType() || ValType->isReferenceType())
5109  ValType = ValType->getPointeeType();
5110  if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5111  if (FPT->getNumParams() == NumArgs)
5112  return true;
5113  }
5114  }
5115 
5116  // A typo for a function-style cast can look like a function call in C++.
5117  if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr
5118  : isa<TypeDecl>(ND)) &&
5119  CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5120  // Only a class or class template can take two or more arguments.
5121  return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND);
5122 
5123  // Skip the current candidate if it is not a FunctionDecl or does not accept
5124  // the current number of arguments.
5125  if (!FD || !(FD->getNumParams() >= NumArgs &&
5126  FD->getMinRequiredArguments() <= NumArgs))
5127  continue;
5128 
5129  // If the current candidate is a non-static C++ method, skip the candidate
5130  // unless the method being corrected--or the current DeclContext, if the
5131  // function being corrected is not a method--is a method in the same class
5132  // or a descendent class of the candidate's parent class.
5133  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
5134  if (MemberFn || !MD->isStatic()) {
5135  CXXMethodDecl *CurMD =
5136  MemberFn
5137  ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
5138  : dyn_cast_or_null<CXXMethodDecl>(CurContext);
5139  CXXRecordDecl *CurRD =
5140  CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5141  CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5142  if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5143  continue;
5144  }
5145  }
5146  return true;
5147  }
5148  return false;
5149 }
5150 
5151 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5152  const PartialDiagnostic &TypoDiag,
5153  bool ErrorRecovery) {
5154  diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5155  ErrorRecovery);
5156 }
5157 
5158 /// Find which declaration we should import to provide the definition of
5159 /// the given declaration.
5161  if (VarDecl *VD = dyn_cast<VarDecl>(D))
5162  return VD->getDefinition();
5163  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5164  return FD->getDefinition();
5165  if (TagDecl *TD = dyn_cast<TagDecl>(D))
5166  return TD->getDefinition();
5167  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5168  return ID->getDefinition();
5169  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5170  return PD->getDefinition();
5171  if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5172  if (NamedDecl *TTD = TD->getTemplatedDecl())
5173  return getDefinitionToImport(TTD);
5174  return nullptr;
5175 }
5176 
5178  MissingImportKind MIK, bool Recover) {
5179  // Suggest importing a module providing the definition of this entity, if
5180  // possible.
5181  NamedDecl *Def = getDefinitionToImport(Decl);
5182  if (!Def)
5183  Def = Decl;
5184 
5185  Module *Owner = getOwningModule(Def);
5186  assert(Owner && "definition of hidden declaration is not in a module");
5187 
5188  llvm::SmallVector<Module*, 8> OwningModules;
5189  OwningModules.push_back(Owner);
5190  auto Merged = Context.getModulesWithMergedDefinition(Def);
5191  OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5192 
5193  diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
5194  Recover);
5195 }
5196 
5197 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5198 /// suggesting the addition of a #include of the specified file.
5200  const FileEntry *E,
5201  llvm::StringRef IncludingFile) {
5202  bool IsSystem = false;
5204  E, IncludingFile, &IsSystem);
5205  return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5206 }
5207 
5209  SourceLocation DeclLoc,
5210  ArrayRef<Module *> Modules,
5211  MissingImportKind MIK, bool Recover) {
5212  assert(!Modules.empty());
5213 
5214  auto NotePrevious = [&] {
5215  unsigned DiagID;
5216  switch (MIK) {
5217  case MissingImportKind::Declaration:
5218  DiagID = diag::note_previous_declaration;
5219  break;
5220  case MissingImportKind::Definition:
5221  DiagID = diag::note_previous_definition;
5222  break;
5223  case MissingImportKind::DefaultArgument:
5224  DiagID = diag::note_default_argument_declared_here;
5225  break;
5226  case MissingImportKind::ExplicitSpecialization:
5227  DiagID = diag::note_explicit_specialization_declared_here;
5228  break;
5229  case MissingImportKind::PartialSpecialization:
5230  DiagID = diag::note_partial_specialization_declared_here;
5231  break;
5232  }
5233  Diag(DeclLoc, DiagID);
5234  };
5235 
5236  // Weed out duplicates from module list.
5237  llvm::SmallVector<Module*, 8> UniqueModules;
5238  llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5239  for (auto *M : Modules) {
5240  if (M->Kind == Module::GlobalModuleFragment)
5241  continue;
5242  if (UniqueModuleSet.insert(M).second)
5243  UniqueModules.push_back(M);
5244  }
5245 
5246  llvm::StringRef IncludingFile;
5247  if (const FileEntry *FE =
5248  SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc)))
5249  IncludingFile = FE->tryGetRealPathName();
5250 
5251  if (UniqueModules.empty()) {
5252  // All candidates were global module fragments. Try to suggest a #include.
5253  const FileEntry *E =
5254  PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, Modules[0], DeclLoc);
5255  // FIXME: Find a smart place to suggest inserting a #include, and add
5256  // a FixItHint there.
5257  Diag(UseLoc, diag::err_module_unimported_use_global_module_fragment)
5258  << (int)MIK << Decl << !!E
5259  << (E ? getIncludeStringForHeader(PP, E, IncludingFile) : "");
5260  // Produce a "previous" note if it will point to a header rather than some
5261  // random global module fragment.
5262  // FIXME: Suppress the note backtrace even under
5263  // -fdiagnostics-show-note-include-stack.
5264  if (E)
5265  NotePrevious();
5266  if (Recover)
5267  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5268  return;
5269  }
5270 
5271  Modules = UniqueModules;
5272 
5273  if (Modules.size() > 1) {
5274  std::string ModuleList;
5275  unsigned N = 0;
5276  for (Module *M : Modules) {
5277  ModuleList += "\n ";
5278  if (++N == 5 && N != Modules.size()) {
5279  ModuleList += "[...]";
5280  break;
5281  }
5282  ModuleList += M->getFullModuleName();
5283  }
5284 
5285  Diag(UseLoc, diag::err_module_unimported_use_multiple)
5286  << (int)MIK << Decl << ModuleList;
5287  } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5288  UseLoc, Modules[0], DeclLoc)) {
5289  // The right way to make the declaration visible is to include a header;
5290  // suggest doing so.
5291  //
5292  // FIXME: Find a smart place to suggest inserting a #include, and add
5293  // a FixItHint there.
5294  Diag(UseLoc, diag::err_module_unimported_use_header)
5295  << (int)MIK << Decl << Modules[0]->getFullModuleName()
5296  << getIncludeStringForHeader(PP, E, IncludingFile);
5297  } else {
5298  // FIXME: Add a FixItHint that imports the corresponding module.
5299  Diag(UseLoc, diag::err_module_unimported_use)
5300  << (int)MIK << Decl << Modules[0]->getFullModuleName();
5301  }
5302 
5303  NotePrevious();
5304 
5305  // Try to recover by implicitly importing this module.
5306  if (Recover)
5307  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5308 }
5309 
5310 /// Diagnose a successfully-corrected typo. Separated from the correction
5311 /// itself to allow external validation of the result, etc.
5312 ///
5313 /// \param Correction The result of performing typo correction.
5314 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5315 /// string added to it (and usually also a fixit).
5316 /// \param PrevNote A note to use when indicating the location of the entity to
5317 /// which we are correcting. Will have the correction string added to it.
5318 /// \param ErrorRecovery If \c true (the default), the caller is going to
5319 /// recover from the typo as if the corrected string had been typed.
5320 /// In this case, \c PDiag must be an error, and we will attach a fixit
5321 /// to it.
5322 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5323  const PartialDiagnostic &TypoDiag,
5324  const PartialDiagnostic &PrevNote,
5325  bool ErrorRecovery) {
5326  std::string CorrectedStr = Correction.getAsString(getLangOpts());
5327  std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5329  Correction.getCorrectionRange(), CorrectedStr);
5330 
5331  // Maybe we're just missing a module import.
5332  if (Correction.requiresImport()) {
5333  NamedDecl *Decl = Correction.getFoundDecl();
5334  assert(Decl && "import required but no declaration to import");
5335 
5336  diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5337  MissingImportKind::Declaration, ErrorRecovery);
5338  return;
5339  }
5340 
5341  Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5342  << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5343 
5344  NamedDecl *ChosenDecl =
5345  Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5346  if (PrevNote.getDiagID() && ChosenDecl)
5347  Diag(ChosenDecl->getLocation(), PrevNote)
5348  << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5349 
5350  // Add any extra diagnostics.
5351  for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5352  Diag(Correction.getCorrectionRange().getBegin(), PD);
5353 }
5354 
5355 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5357  TypoRecoveryCallback TRC) {
5358  assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5359  auto TE = new (Context) TypoExpr(Context.DependentTy);
5360  auto &State = DelayedTypos[TE];
5361  State.Consumer = std::move(TCC);
5362  State.DiagHandler = std::move(TDG);
5363  State.RecoveryHandler = std::move(TRC);
5364  return TE;
5365 }
5366 
5367 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5368  auto Entry = DelayedTypos.find(TE);
5369  assert(Entry != DelayedTypos.end() &&
5370  "Failed to get the state for a TypoExpr!");
5371  return Entry->second;
5372 }
5373 
5375  DelayedTypos.erase(TE);
5376 }
5377 
5379  DeclarationNameInfo Name(II, IILoc);
5380  LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5381  R.suppressDiagnostics();
5382  R.setHideTags(false);
5383  LookupName(R, S);
5384  R.dump();
5385 }
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:1597
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:1748
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:1895
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:1128
no exception specification
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2569
A (possibly-)qualified type.
Definition: Type.h:643
Simple class containing the result of Sema::CorrectTypo.
base_class_range bases()
Definition: DeclCXX.h:825
ValueDecl * getMemberDecl() const
Retrieve the member declaration to which this expression refers.
Definition: Expr.h:2890
bool hasVisibleDeclarationSlow(const NamedDecl *D, llvm::SmallVectorImpl< Module *> *Modules)
CorrectTypoKind
Definition: Sema.h:3442
virtual unsigned RankCandidate(const TypoCorrection &candidate)
Method used by Sema::CorrectTypo to assign an "edit distance" rank to a candidate (where a lower valu...
static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, bool QualifiedNameLookup, bool InBaseClass, VisibleDeclConsumer &Consumer, VisibleDeclsRecord &Visited, bool IncludeDependentBases, bool LoadExternal)
Template argument deduction was successful.
Definition: Sema.h:7241
Defines the clang::FileManager interface and associated types.
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3224
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:3258
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:3387
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:505
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:813
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:274
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:1023
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
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:877
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:7584
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:1433
SourceLocation getBeginLoc() const
getBeginLoc - Retrieve the location of the first token.
MissingImportKind
Kinds of missing import.
Definition: Sema.h:2305
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:514
RedeclarationKind
Specifies whether (or how) name lookup is being performed for a redeclaration (vs.
Definition: Sema.h:3271
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:112
const NestedNameSpecifier * Specifier
Look up of a name that precedes the &#39;::&#39; scope resolution operator in C++.
Definition: Sema.h:3240
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:1163
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:3296
unsigned getIdentifierNamespace() const
Definition: DeclBase.h:799
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2566
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:3202
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:3244
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.
static bool LookupBuiltin(Sema &S, LookupResult &R)
Lookup a builtin function, when name lookup would otherwise fail.
Definition: SemaLookup.cpp:751
Represents a variable declaration or definition.
Definition: Decl.h:812
NamedDecl * LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID, Scope *S, bool ForRedeclaration, SourceLocation Loc)
LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope.
Definition: SemaDecl.cpp:1979
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:6851
PrintingPolicy getPrintingPolicy() const
Retrieve a suitable printing policy for diagnostics.
Definition: Sema.h:2338
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:3799
static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class)
Determine whether we can declare a special member function within the class at this point...
Definition: SemaLookup.cpp:804
bool needsImplicitCopyAssignment() const
Determine whether this class needs an implicit copy assignment operator to be lazily declared...
Definition: DeclCXX.h:1114
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:431
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:3253
Represents a parameter to a function.
Definition: Decl.h:1564
Defines the clang::Expr interface and subclasses for C++ expressions.
long i
Definition: xmmintrin.h:1456
void addKeywordResult(StringRef Keyword)
void setMethod(CXXMethodDecl *MD)
Definition: Sema.h:1129
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:3626
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:1152
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3800
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:154
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:1766
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:1272
bool isReferenceType() const
Definition: Type.h:6396
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:1714
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:385
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
IdentifierTable & Idents
Definition: ASTContext.h:569
SpecialMemberOverloadResult - The overloading result for a special member function.
Definition: Sema.h:1112
void setCallbackDistance(unsigned ED)
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:124
static void InsertOCLBuiltinDeclarations(Sema &S, LookupResult &LR, IdentifierInfo *II, unsigned Index, unsigned Len)
When trying to resolve a function name, if the isOpenCLBuiltin function defined in "OpenCLBuiltins...
Definition: SemaLookup.cpp:686
DeclClass * getAsSingle() const
Definition: Lookup.h:507
StringRef getTopLevelModuleName() const
Retrieve the name of the top-level module.
Definition: Module.h:467
CXXBasePaths * getBasePaths() const
Return the base paths structure that&#39;s associated with these results, or null if none is...
Definition: Lookup.h:343
bool isTemplateNameLookup() const
Definition: Lookup.h:299
CXXRecordDecl * getAsRecordDecl() const
Retrieve the record declaration stored in this nested name specifier.
Look up implicit &#39;self&#39; parameter of an objective-c method.
Definition: Sema.h:3260
IdentifierInfo * getAsIdentifier() const
Retrieve the identifier stored in this nested name specifier.
void resolveKind()
Resolves the result kind of the lookup, possibly hiding decls.
Definition: SemaLookup.cpp:475
Represents the results of name lookup.
Definition: Lookup.h:46
void setAmbiguousBaseSubobjects(CXXBasePaths &P)
Make these results show that the name was found in distinct base classes of the same type...
Definition: SemaLookup.cpp:642
static DeclAccessPair make(NamedDecl *D, AccessSpecifier AS)
virtual bool includeHiddenDecls() const
Determine whether hidden declarations (from unimported modules) should be given to this consumer...
ObjCMethodDecl * getCurMethodDecl()
getCurMethodDecl - If inside of a method body, this returns a pointer to the method decl for the meth...
Definition: Sema.cpp:1243
Namespaces, declared with &#39;namespace foo {}&#39;.
Definition: DeclBase.h:142
static void LookupPotentialTypoResult(Sema &SemaRef, LookupResult &Res, IdentifierInfo *Name, Scope *S, CXXScopeSpec *SS, DeclContext *MemberContext, bool EnteringContext, bool isObjCIvarLookup, bool FindHidden)
Perform name lookup for a possible result for typo correction.
HeaderSearch & getHeaderSearchInfo() const
Definition: Preprocessor.h:908
void setQualifierDistance(unsigned ED)
bool hasTagIdentifierNamespace() const
Definition: DeclBase.h:809
Succeeded, but refers to a deleted function.
Definition: Overload.h:62
bool ValidateCandidate(const TypoCorrection &candidate) override
Simple predicate used by the default RankCandidate to determine whether to return an edit distance of...
Module * getOwningModule(Decl *Entity)
Get the module owning an entity.
Definition: Sema.h:1680
CXXConstructorDecl * DeclareImplicitMoveConstructor(CXXRecordDecl *ClassDecl)
Declare the implicit move constructor for the given class.
Look up all declarations in a scope with the given name, including resolved using declarations...
Definition: Sema.h:3248
static NamedDecl * getDefinitionToImport(NamedDecl *D)
Find which declaration we should import to provide the definition of the given declaration.
NamespaceAliasDecl * getAsNamespaceAlias() const
Retrieve the namespace alias stored in this nested name specifier.
TemplateDecl * getAsTypeTemplateDecl(Decl *D)