clang  10.0.0svn
SemaLookup.cpp
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1 //===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements name lookup for C, C++, Objective-C, and
10 // Objective-C++.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/DeclLookups.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/DeclTemplate.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/Basic/Builtins.h"
26 #include "clang/Lex/HeaderSearch.h"
27 #include "clang/Lex/ModuleLoader.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Sema/DeclSpec.h"
30 #include "clang/Sema/Lookup.h"
31 #include "clang/Sema/Overload.h"
32 #include "clang/Sema/Scope.h"
33 #include "clang/Sema/ScopeInfo.h"
34 #include "clang/Sema/Sema.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/ADT/SmallPtrSet.h"
40 #include "llvm/ADT/TinyPtrVector.h"
41 #include "llvm/ADT/edit_distance.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include <algorithm>
44 #include <iterator>
45 #include <list>
46 #include <set>
47 #include <utility>
48 #include <vector>
49 
50 #include "OpenCLBuiltins.inc"
51 
52 using namespace clang;
53 using namespace sema;
54 
55 namespace {
56  class UnqualUsingEntry {
57  const DeclContext *Nominated;
58  const DeclContext *CommonAncestor;
59 
60  public:
61  UnqualUsingEntry(const DeclContext *Nominated,
62  const DeclContext *CommonAncestor)
63  : Nominated(Nominated), CommonAncestor(CommonAncestor) {
64  }
65 
66  const DeclContext *getCommonAncestor() const {
67  return CommonAncestor;
68  }
69 
70  const DeclContext *getNominatedNamespace() const {
71  return Nominated;
72  }
73 
74  // Sort by the pointer value of the common ancestor.
75  struct Comparator {
76  bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
77  return L.getCommonAncestor() < R.getCommonAncestor();
78  }
79 
80  bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
81  return E.getCommonAncestor() < DC;
82  }
83 
84  bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
85  return DC < E.getCommonAncestor();
86  }
87  };
88  };
89 
90  /// A collection of using directives, as used by C++ unqualified
91  /// lookup.
92  class UnqualUsingDirectiveSet {
93  Sema &SemaRef;
94 
95  typedef SmallVector<UnqualUsingEntry, 8> ListTy;
96 
97  ListTy list;
98  llvm::SmallPtrSet<DeclContext*, 8> visited;
99 
100  public:
101  UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {}
102 
103  void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
104  // C++ [namespace.udir]p1:
105  // During unqualified name lookup, the names appear as if they
106  // were declared in the nearest enclosing namespace which contains
107  // both the using-directive and the nominated namespace.
108  DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
109  assert(InnermostFileDC && InnermostFileDC->isFileContext());
110 
111  for (; S; S = S->getParent()) {
112  // C++ [namespace.udir]p1:
113  // A using-directive shall not appear in class scope, but may
114  // appear in namespace scope or in block scope.
115  DeclContext *Ctx = S->getEntity();
116  if (Ctx && Ctx->isFileContext()) {
117  visit(Ctx, Ctx);
118  } else if (!Ctx || Ctx->isFunctionOrMethod()) {
119  for (auto *I : S->using_directives())
120  if (SemaRef.isVisible(I))
121  visit(I, InnermostFileDC);
122  }
123  }
124  }
125 
126  // Visits a context and collect all of its using directives
127  // recursively. Treats all using directives as if they were
128  // declared in the context.
129  //
130  // A given context is only every visited once, so it is important
131  // that contexts be visited from the inside out in order to get
132  // the effective DCs right.
133  void visit(DeclContext *DC, DeclContext *EffectiveDC) {
134  if (!visited.insert(DC).second)
135  return;
136 
137  addUsingDirectives(DC, EffectiveDC);
138  }
139 
140  // Visits a using directive and collects all of its using
141  // directives recursively. Treats all using directives as if they
142  // were declared in the effective DC.
143  void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
145  if (!visited.insert(NS).second)
146  return;
147 
148  addUsingDirective(UD, EffectiveDC);
149  addUsingDirectives(NS, EffectiveDC);
150  }
151 
152  // Adds all the using directives in a context (and those nominated
153  // by its using directives, transitively) as if they appeared in
154  // the given effective context.
155  void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
157  while (true) {
158  for (auto UD : DC->using_directives()) {
160  if (SemaRef.isVisible(UD) && visited.insert(NS).second) {
161  addUsingDirective(UD, EffectiveDC);
162  queue.push_back(NS);
163  }
164  }
165 
166  if (queue.empty())
167  return;
168 
169  DC = queue.pop_back_val();
170  }
171  }
172 
173  // Add a using directive as if it had been declared in the given
174  // context. This helps implement C++ [namespace.udir]p3:
175  // The using-directive is transitive: if a scope contains a
176  // using-directive that nominates a second namespace that itself
177  // contains using-directives, the effect is as if the
178  // using-directives from the second namespace also appeared in
179  // the first.
180  void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
181  // Find the common ancestor between the effective context and
182  // the nominated namespace.
183  DeclContext *Common = UD->getNominatedNamespace();
184  while (!Common->Encloses(EffectiveDC))
185  Common = Common->getParent();
186  Common = Common->getPrimaryContext();
187 
188  list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
189  }
190 
191  void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); }
192 
193  typedef ListTy::const_iterator const_iterator;
194 
195  const_iterator begin() const { return list.begin(); }
196  const_iterator end() const { return list.end(); }
197 
198  llvm::iterator_range<const_iterator>
199  getNamespacesFor(DeclContext *DC) const {
200  return llvm::make_range(std::equal_range(begin(), end(),
201  DC->getPrimaryContext(),
202  UnqualUsingEntry::Comparator()));
203  }
204  };
205 } // end anonymous namespace
206 
207 // Retrieve the set of identifier namespaces that correspond to a
208 // specific kind of name lookup.
209 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
210  bool CPlusPlus,
211  bool Redeclaration) {
212  unsigned IDNS = 0;
213  switch (NameKind) {
218  IDNS = Decl::IDNS_Ordinary;
219  if (CPlusPlus) {
221  if (Redeclaration)
223  }
224  if (Redeclaration)
225  IDNS |= Decl::IDNS_LocalExtern;
226  break;
227 
229  // Operator lookup is its own crazy thing; it is not the same
230  // as (e.g.) looking up an operator name for redeclaration.
231  assert(!Redeclaration && "cannot do redeclaration operator lookup");
233  break;
234 
235  case Sema::LookupTagName:
236  if (CPlusPlus) {
237  IDNS = Decl::IDNS_Type;
238 
239  // When looking for a redeclaration of a tag name, we add:
240  // 1) TagFriend to find undeclared friend decls
241  // 2) Namespace because they can't "overload" with tag decls.
242  // 3) Tag because it includes class templates, which can't
243  // "overload" with tag decls.
244  if (Redeclaration)
246  } else {
247  IDNS = Decl::IDNS_Tag;
248  }
249  break;
250 
251  case Sema::LookupLabel:
252  IDNS = Decl::IDNS_Label;
253  break;
254 
256  IDNS = Decl::IDNS_Member;
257  if (CPlusPlus)
259  break;
260 
263  break;
264 
266  IDNS = Decl::IDNS_Namespace;
267  break;
268 
270  assert(Redeclaration && "should only be used for redecl lookup");
274  break;
275 
278  break;
279 
282  break;
283 
285  IDNS = Decl::IDNS_OMPMapper;
286  break;
287 
288  case Sema::LookupAnyName:
291  | Decl::IDNS_Type;
292  break;
293  }
294  return IDNS;
295 }
296 
297 void LookupResult::configure() {
298  IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
299  isForRedeclaration());
300 
301  // If we're looking for one of the allocation or deallocation
302  // operators, make sure that the implicitly-declared new and delete
303  // operators can be found.
304  switch (NameInfo.getName().getCXXOverloadedOperator()) {
305  case OO_New:
306  case OO_Delete:
307  case OO_Array_New:
308  case OO_Array_Delete:
309  getSema().DeclareGlobalNewDelete();
310  break;
311 
312  default:
313  break;
314  }
315 
316  // Compiler builtins are always visible, regardless of where they end
317  // up being declared.
318  if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
319  if (unsigned BuiltinID = Id->getBuiltinID()) {
320  if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
321  AllowHidden = true;
322  }
323  }
324 }
325 
326 bool LookupResult::sanity() const {
327  // This function is never called by NDEBUG builds.
328  assert(ResultKind != NotFound || Decls.size() == 0);
329  assert(ResultKind != Found || Decls.size() == 1);
330  assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
331  (Decls.size() == 1 &&
332  isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
333  assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
334  assert(ResultKind != Ambiguous || Decls.size() > 1 ||
335  (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
336  Ambiguity == AmbiguousBaseSubobjectTypes)));
337  assert((Paths != nullptr) == (ResultKind == Ambiguous &&
338  (Ambiguity == AmbiguousBaseSubobjectTypes ||
339  Ambiguity == AmbiguousBaseSubobjects)));
340  return true;
341 }
342 
343 // Necessary because CXXBasePaths is not complete in Sema.h
344 void LookupResult::deletePaths(CXXBasePaths *Paths) {
345  delete Paths;
346 }
347 
348 /// Get a representative context for a declaration such that two declarations
349 /// will have the same context if they were found within the same scope.
351  // For function-local declarations, use that function as the context. This
352  // doesn't account for scopes within the function; the caller must deal with
353  // those.
355  if (DC->isFunctionOrMethod())
356  return DC;
357 
358  // Otherwise, look at the semantic context of the declaration. The
359  // declaration must have been found there.
360  return D->getDeclContext()->getRedeclContext();
361 }
362 
363 /// Determine whether \p D is a better lookup result than \p Existing,
364 /// given that they declare the same entity.
366  NamedDecl *D, NamedDecl *Existing) {
367  // When looking up redeclarations of a using declaration, prefer a using
368  // shadow declaration over any other declaration of the same entity.
369  if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
370  !isa<UsingShadowDecl>(Existing))
371  return true;
372 
373  auto *DUnderlying = D->getUnderlyingDecl();
374  auto *EUnderlying = Existing->getUnderlyingDecl();
375 
376  // If they have different underlying declarations, prefer a typedef over the
377  // original type (this happens when two type declarations denote the same
378  // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
379  // might carry additional semantic information, such as an alignment override.
380  // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
381  // declaration over a typedef.
382  if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
383  assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
384  bool HaveTag = isa<TagDecl>(EUnderlying);
385  bool WantTag = Kind == Sema::LookupTagName;
386  return HaveTag != WantTag;
387  }
388 
389  // Pick the function with more default arguments.
390  // FIXME: In the presence of ambiguous default arguments, we should keep both,
391  // so we can diagnose the ambiguity if the default argument is needed.
392  // See C++ [over.match.best]p3.
393  if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
394  auto *EFD = cast<FunctionDecl>(EUnderlying);
395  unsigned DMin = DFD->getMinRequiredArguments();
396  unsigned EMin = EFD->getMinRequiredArguments();
397  // If D has more default arguments, it is preferred.
398  if (DMin != EMin)
399  return DMin < EMin;
400  // FIXME: When we track visibility for default function arguments, check
401  // that we pick the declaration with more visible default arguments.
402  }
403 
404  // Pick the template with more default template arguments.
405  if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
406  auto *ETD = cast<TemplateDecl>(EUnderlying);
407  unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
408  unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
409  // If D has more default arguments, it is preferred. Note that default
410  // arguments (and their visibility) is monotonically increasing across the
411  // redeclaration chain, so this is a quick proxy for "is more recent".
412  if (DMin != EMin)
413  return DMin < EMin;
414  // If D has more *visible* default arguments, it is preferred. Note, an
415  // earlier default argument being visible does not imply that a later
416  // default argument is visible, so we can't just check the first one.
417  for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
418  I != N; ++I) {
420  ETD->getTemplateParameters()->getParam(I)) &&
422  DTD->getTemplateParameters()->getParam(I)))
423  return true;
424  }
425  }
426 
427  // VarDecl can have incomplete array types, prefer the one with more complete
428  // array type.
429  if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
430  VarDecl *EVD = cast<VarDecl>(EUnderlying);
431  if (EVD->getType()->isIncompleteType() &&
432  !DVD->getType()->isIncompleteType()) {
433  // Prefer the decl with a more complete type if visible.
434  return S.isVisible(DVD);
435  }
436  return false; // Avoid picking up a newer decl, just because it was newer.
437  }
438 
439  // For most kinds of declaration, it doesn't really matter which one we pick.
440  if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
441  // If the existing declaration is hidden, prefer the new one. Otherwise,
442  // keep what we've got.
443  return !S.isVisible(Existing);
444  }
445 
446  // Pick the newer declaration; it might have a more precise type.
447  for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
448  Prev = Prev->getPreviousDecl())
449  if (Prev == EUnderlying)
450  return true;
451  return false;
452 }
453 
454 /// Determine whether \p D can hide a tag declaration.
455 static bool canHideTag(NamedDecl *D) {
456  // C++ [basic.scope.declarative]p4:
457  // Given a set of declarations in a single declarative region [...]
458  // exactly one declaration shall declare a class name or enumeration name
459  // that is not a typedef name and the other declarations shall all refer to
460  // the same variable, non-static data member, or enumerator, or all refer
461  // to functions and function templates; in this case the class name or
462  // enumeration name is hidden.
463  // C++ [basic.scope.hiding]p2:
464  // A class name or enumeration name can be hidden by the name of a
465  // variable, data member, function, or enumerator declared in the same
466  // scope.
467  // An UnresolvedUsingValueDecl always instantiates to one of these.
468  D = D->getUnderlyingDecl();
469  return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
470  isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
471  isa<UnresolvedUsingValueDecl>(D);
472 }
473 
474 /// Resolves the result kind of this lookup.
476  unsigned N = Decls.size();
477 
478  // Fast case: no possible ambiguity.
479  if (N == 0) {
480  assert(ResultKind == NotFound ||
481  ResultKind == NotFoundInCurrentInstantiation);
482  return;
483  }
484 
485  // If there's a single decl, we need to examine it to decide what
486  // kind of lookup this is.
487  if (N == 1) {
488  NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
489  if (isa<FunctionTemplateDecl>(D))
490  ResultKind = FoundOverloaded;
491  else if (isa<UnresolvedUsingValueDecl>(D))
492  ResultKind = FoundUnresolvedValue;
493  return;
494  }
495 
496  // Don't do any extra resolution if we've already resolved as ambiguous.
497  if (ResultKind == Ambiguous) return;
498 
499  llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
500  llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
501 
502  bool Ambiguous = false;
503  bool HasTag = false, HasFunction = false;
504  bool HasFunctionTemplate = false, HasUnresolved = false;
505  NamedDecl *HasNonFunction = nullptr;
506 
507  llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
508 
509  unsigned UniqueTagIndex = 0;
510 
511  unsigned I = 0;
512  while (I < N) {
513  NamedDecl *D = Decls[I]->getUnderlyingDecl();
514  D = cast<NamedDecl>(D->getCanonicalDecl());
515 
516  // Ignore an invalid declaration unless it's the only one left.
517  if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
518  Decls[I] = Decls[--N];
519  continue;
520  }
521 
522  llvm::Optional<unsigned> ExistingI;
523 
524  // Redeclarations of types via typedef can occur both within a scope
525  // and, through using declarations and directives, across scopes. There is
526  // no ambiguity if they all refer to the same type, so unique based on the
527  // canonical type.
528  if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
529  QualType T = getSema().Context.getTypeDeclType(TD);
530  auto UniqueResult = UniqueTypes.insert(
531  std::make_pair(getSema().Context.getCanonicalType(T), I));
532  if (!UniqueResult.second) {
533  // The type is not unique.
534  ExistingI = UniqueResult.first->second;
535  }
536  }
537 
538  // For non-type declarations, check for a prior lookup result naming this
539  // canonical declaration.
540  if (!ExistingI) {
541  auto UniqueResult = Unique.insert(std::make_pair(D, I));
542  if (!UniqueResult.second) {
543  // We've seen this entity before.
544  ExistingI = UniqueResult.first->second;
545  }
546  }
547 
548  if (ExistingI) {
549  // This is not a unique lookup result. Pick one of the results and
550  // discard the other.
551  if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
552  Decls[*ExistingI]))
553  Decls[*ExistingI] = Decls[I];
554  Decls[I] = Decls[--N];
555  continue;
556  }
557 
558  // Otherwise, do some decl type analysis and then continue.
559 
560  if (isa<UnresolvedUsingValueDecl>(D)) {
561  HasUnresolved = true;
562  } else if (isa<TagDecl>(D)) {
563  if (HasTag)
564  Ambiguous = true;
565  UniqueTagIndex = I;
566  HasTag = true;
567  } else if (isa<FunctionTemplateDecl>(D)) {
568  HasFunction = true;
569  HasFunctionTemplate = true;
570  } else if (isa<FunctionDecl>(D)) {
571  HasFunction = true;
572  } else {
573  if (HasNonFunction) {
574  // If we're about to create an ambiguity between two declarations that
575  // are equivalent, but one is an internal linkage declaration from one
576  // module and the other is an internal linkage declaration from another
577  // module, just skip it.
578  if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
579  D)) {
580  EquivalentNonFunctions.push_back(D);
581  Decls[I] = Decls[--N];
582  continue;
583  }
584 
585  Ambiguous = true;
586  }
587  HasNonFunction = D;
588  }
589  I++;
590  }
591 
592  // C++ [basic.scope.hiding]p2:
593  // A class name or enumeration name can be hidden by the name of
594  // an object, function, or enumerator declared in the same
595  // scope. If a class or enumeration name and an object, function,
596  // or enumerator are declared in the same scope (in any order)
597  // with the same name, the class or enumeration name is hidden
598  // wherever the object, function, or enumerator name is visible.
599  // But it's still an error if there are distinct tag types found,
600  // even if they're not visible. (ref?)
601  if (N > 1 && HideTags && HasTag && !Ambiguous &&
602  (HasFunction || HasNonFunction || HasUnresolved)) {
603  NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
604  if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
605  getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
606  getContextForScopeMatching(OtherDecl)) &&
607  canHideTag(OtherDecl))
608  Decls[UniqueTagIndex] = Decls[--N];
609  else
610  Ambiguous = true;
611  }
612 
613  // FIXME: This diagnostic should really be delayed until we're done with
614  // the lookup result, in case the ambiguity is resolved by the caller.
615  if (!EquivalentNonFunctions.empty() && !Ambiguous)
616  getSema().diagnoseEquivalentInternalLinkageDeclarations(
617  getNameLoc(), HasNonFunction, EquivalentNonFunctions);
618 
619  Decls.set_size(N);
620 
621  if (HasNonFunction && (HasFunction || HasUnresolved))
622  Ambiguous = true;
623 
624  if (Ambiguous)
625  setAmbiguous(LookupResult::AmbiguousReference);
626  else if (HasUnresolved)
628  else if (N > 1 || HasFunctionTemplate)
629  ResultKind = LookupResult::FoundOverloaded;
630  else
631  ResultKind = LookupResult::Found;
632 }
633 
634 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
636  for (I = P.begin(), E = P.end(); I != E; ++I)
637  for (DeclContext::lookup_iterator DI = I->Decls.begin(),
638  DE = I->Decls.end(); DI != DE; ++DI)
639  addDecl(*DI);
640 }
641 
643  Paths = new CXXBasePaths;
644  Paths->swap(P);
645  addDeclsFromBasePaths(*Paths);
646  resolveKind();
647  setAmbiguous(AmbiguousBaseSubobjects);
648 }
649 
651  Paths = new CXXBasePaths;
652  Paths->swap(P);
653  addDeclsFromBasePaths(*Paths);
654  resolveKind();
655  setAmbiguous(AmbiguousBaseSubobjectTypes);
656 }
657 
658 void LookupResult::print(raw_ostream &Out) {
659  Out << Decls.size() << " result(s)";
660  if (isAmbiguous()) Out << ", ambiguous";
661  if (Paths) Out << ", base paths present";
662 
663  for (iterator I = begin(), E = end(); I != E; ++I) {
664  Out << "\n";
665  (*I)->print(Out, 2);
666  }
667 }
668 
669 LLVM_DUMP_METHOD void LookupResult::dump() {
670  llvm::errs() << "lookup results for " << getLookupName().getAsString()
671  << ":\n";
672  for (NamedDecl *D : *this)
673  D->dump();
674 }
675 
676 /// Get the QualType instances of the return type and arguments for an OpenCL
677 /// builtin function signature.
678 /// \param Context (in) The Context instance.
679 /// \param OpenCLBuiltin (in) The signature currently handled.
680 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
681 /// type used as return type or as argument.
682 /// Only meaningful for generic types, otherwise equals 1.
683 /// \param RetTypes (out) List of the possible return types.
684 /// \param ArgTypes (out) List of the possible argument types. For each
685 /// argument, ArgTypes contains QualTypes for the Cartesian product
686 /// of (vector sizes) x (types) .
688  ASTContext &Context, const OpenCLBuiltinStruct &OpenCLBuiltin,
689  unsigned &GenTypeMaxCnt, SmallVector<QualType, 1> &RetTypes,
690  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
691  // Get the QualType instances of the return types.
692  unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
693  OCL2Qual(Context, TypeTable[Sig], RetTypes);
694  GenTypeMaxCnt = RetTypes.size();
695 
696  // Get the QualType instances of the arguments.
697  // First type is the return type, skip it.
698  for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
700  OCL2Qual(Context,
701  TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], Ty);
702  GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
703  ArgTypes.push_back(std::move(Ty));
704  }
705 }
706 
707 /// Create a list of the candidate function overloads for an OpenCL builtin
708 /// function.
709 /// \param Context (in) The ASTContext instance.
710 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
711 /// type used as return type or as argument.
712 /// Only meaningful for generic types, otherwise equals 1.
713 /// \param FunctionList (out) List of FunctionTypes.
714 /// \param RetTypes (in) List of the possible return types.
715 /// \param ArgTypes (in) List of the possible types for the arguments.
717  ASTContext &Context, unsigned GenTypeMaxCnt,
718  std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes,
719  SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
721  PI.Variadic = false;
722 
723  // Create FunctionTypes for each (gen)type.
724  for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
725  SmallVector<QualType, 5> ArgList;
726 
727  for (unsigned A = 0; A < ArgTypes.size(); A++) {
728  // Builtins such as "max" have an "sgentype" argument that represents
729  // the corresponding scalar type of a gentype. The number of gentypes
730  // must be a multiple of the number of sgentypes.
731  assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
732  "argument type count not compatible with gentype type count");
733  unsigned Idx = IGenType % ArgTypes[A].size();
734  ArgList.push_back(ArgTypes[A][Idx]);
735  }
736 
737  FunctionList.push_back(Context.getFunctionType(
738  RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI));
739  }
740 }
741 
742 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a
743 /// non-null <Index, Len> pair, then the name is referencing an OpenCL
744 /// builtin function. Add all candidate signatures to the LookUpResult.
745 ///
746 /// \param S (in) The Sema instance.
747 /// \param LR (inout) The LookupResult instance.
748 /// \param II (in) The identifier being resolved.
749 /// \param FctIndex (in) Starting index in the BuiltinTable.
750 /// \param Len (in) The signature list has Len elements.
752  IdentifierInfo *II,
753  const unsigned FctIndex,
754  const unsigned Len) {
755  // The builtin function declaration uses generic types (gentype).
756  bool HasGenType = false;
757 
758  // Maximum number of types contained in a generic type used as return type or
759  // as argument. Only meaningful for generic types, otherwise equals 1.
760  unsigned GenTypeMaxCnt;
761 
762  for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
763  const OpenCLBuiltinStruct &OpenCLBuiltin =
764  BuiltinTable[FctIndex + SignatureIndex];
765  ASTContext &Context = S.Context;
766 
767  SmallVector<QualType, 1> RetTypes;
769 
770  // Obtain QualType lists for the function signature.
771  GetQualTypesForOpenCLBuiltin(Context, OpenCLBuiltin, GenTypeMaxCnt,
772  RetTypes, ArgTypes);
773  if (GenTypeMaxCnt > 1) {
774  HasGenType = true;
775  }
776 
777  // Create function overload for each type combination.
778  std::vector<QualType> FunctionList;
779  GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
780  ArgTypes);
781 
782  SourceLocation Loc = LR.getNameLoc();
784  FunctionDecl *NewOpenCLBuiltin;
785 
786  for (unsigned Index = 0; Index < GenTypeMaxCnt; Index++) {
787  NewOpenCLBuiltin = FunctionDecl::Create(
788  Context, Parent, Loc, Loc, II, FunctionList[Index],
789  /*TInfo=*/nullptr, SC_Extern, false,
790  FunctionList[Index]->isFunctionProtoType());
791  NewOpenCLBuiltin->setImplicit();
792 
793  // Create Decl objects for each parameter, adding them to the
794  // FunctionDecl.
795  if (const FunctionProtoType *FP =
796  dyn_cast<FunctionProtoType>(FunctionList[Index])) {
798  for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
800  Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(),
801  nullptr, FP->getParamType(IParm),
802  /*TInfo=*/nullptr, SC_None, nullptr);
803  Parm->setScopeInfo(0, IParm);
804  ParmList.push_back(Parm);
805  }
806  NewOpenCLBuiltin->setParams(ParmList);
807  }
808  if (!S.getLangOpts().OpenCLCPlusPlus) {
809  NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context));
810  }
811  LR.addDecl(NewOpenCLBuiltin);
812  }
813  }
814 
815  // If we added overloads, need to resolve the lookup result.
816  if (Len > 1 || HasGenType)
817  LR.resolveKind();
818 }
819 
820 /// Lookup a builtin function, when name lookup would otherwise
821 /// fail.
822 static bool LookupBuiltin(Sema &S, LookupResult &R) {
823  Sema::LookupNameKind NameKind = R.getLookupKind();
824 
825  // If we didn't find a use of this identifier, and if the identifier
826  // corresponds to a compiler builtin, create the decl object for the builtin
827  // now, injecting it into translation unit scope, and return it.
828  if (NameKind == Sema::LookupOrdinaryName ||
831  if (II) {
832  if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
833  if (II == S.getASTContext().getMakeIntegerSeqName()) {
835  return true;
836  } else if (II == S.getASTContext().getTypePackElementName()) {
838  return true;
839  }
840  }
841 
842  // Check if this is an OpenCL Builtin, and if so, insert its overloads.
843  if (S.getLangOpts().OpenCL && S.getLangOpts().DeclareOpenCLBuiltins) {
844  auto Index = isOpenCLBuiltin(II->getName());
845  if (Index.first) {
846  InsertOCLBuiltinDeclarationsFromTable(S, R, II, Index.first - 1,
847  Index.second);
848  return true;
849  }
850  }
851 
852  // If this is a builtin on this (or all) targets, create the decl.
853  if (unsigned BuiltinID = II->getBuiltinID()) {
854  // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
855  // library functions like 'malloc'. Instead, we'll just error.
856  if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
858  return false;
859 
861  BuiltinID, S.TUScope,
862  R.isForRedeclaration(),
863  R.getNameLoc())) {
864  R.addDecl(D);
865  return true;
866  }
867  }
868  }
869  }
870 
871  return false;
872 }
873 
874 /// Determine whether we can declare a special member function within
875 /// the class at this point.
877  // We need to have a definition for the class.
878  if (!Class->getDefinition() || Class->isDependentContext())
879  return false;
880 
881  // We can't be in the middle of defining the class.
882  return !Class->isBeingDefined();
883 }
884 
887  return;
888 
889  // If the default constructor has not yet been declared, do so now.
890  if (Class->needsImplicitDefaultConstructor())
891  DeclareImplicitDefaultConstructor(Class);
892 
893  // If the copy constructor has not yet been declared, do so now.
894  if (Class->needsImplicitCopyConstructor())
895  DeclareImplicitCopyConstructor(Class);
896 
897  // If the copy assignment operator has not yet been declared, do so now.
898  if (Class->needsImplicitCopyAssignment())
899  DeclareImplicitCopyAssignment(Class);
900 
901  if (getLangOpts().CPlusPlus11) {
902  // If the move constructor has not yet been declared, do so now.
903  if (Class->needsImplicitMoveConstructor())
904  DeclareImplicitMoveConstructor(Class);
905 
906  // If the move assignment operator has not yet been declared, do so now.
907  if (Class->needsImplicitMoveAssignment())
908  DeclareImplicitMoveAssignment(Class);
909  }
910 
911  // If the destructor has not yet been declared, do so now.
912  if (Class->needsImplicitDestructor())
913  DeclareImplicitDestructor(Class);
914 }
915 
916 /// Determine whether this is the name of an implicitly-declared
917 /// special member function.
919  switch (Name.getNameKind()) {
922  return true;
923 
925  return Name.getCXXOverloadedOperator() == OO_Equal;
926 
927  default:
928  break;
929  }
930 
931  return false;
932 }
933 
934 /// If there are any implicit member functions with the given name
935 /// that need to be declared in the given declaration context, do so.
937  DeclarationName Name,
938  SourceLocation Loc,
939  const DeclContext *DC) {
940  if (!DC)
941  return;
942 
943  switch (Name.getNameKind()) {
945  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
946  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
947  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
948  if (Record->needsImplicitDefaultConstructor())
950  if (Record->needsImplicitCopyConstructor())
952  if (S.getLangOpts().CPlusPlus11 &&
953  Record->needsImplicitMoveConstructor())
955  }
956  break;
957 
959  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
960  if (Record->getDefinition() && Record->needsImplicitDestructor() &&
962  S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
963  break;
964 
966  if (Name.getCXXOverloadedOperator() != OO_Equal)
967  break;
968 
969  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
970  if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
971  CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
972  if (Record->needsImplicitCopyAssignment())
974  if (S.getLangOpts().CPlusPlus11 &&
975  Record->needsImplicitMoveAssignment())
977  }
978  }
979  break;
980 
983  break;
984 
985  default:
986  break;
987  }
988 }
989 
990 // Adds all qualifying matches for a name within a decl context to the
991 // given lookup result. Returns true if any matches were found.
992 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
993  bool Found = false;
994 
995  // Lazily declare C++ special member functions.
996  if (S.getLangOpts().CPlusPlus)
998  DC);
999 
1000  // Perform lookup into this declaration context.
1002  for (NamedDecl *D : DR) {
1003  if ((D = R.getAcceptableDecl(D))) {
1004  R.addDecl(D);
1005  Found = true;
1006  }
1007  }
1008 
1009  if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
1010  return true;
1011 
1012  if (R.getLookupName().getNameKind()
1015  !isa<CXXRecordDecl>(DC))
1016  return Found;
1017 
1018  // C++ [temp.mem]p6:
1019  // A specialization of a conversion function template is not found by
1020  // name lookup. Instead, any conversion function templates visible in the
1021  // context of the use are considered. [...]
1022  const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1023  if (!Record->isCompleteDefinition())
1024  return Found;
1025 
1026  // For conversion operators, 'operator auto' should only match
1027  // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
1028  // as a candidate for template substitution.
1029  auto *ContainedDeducedType =
1031  if (R.getLookupName().getNameKind() ==
1033  ContainedDeducedType && ContainedDeducedType->isUndeducedType())
1034  return Found;
1035 
1037  UEnd = Record->conversion_end(); U != UEnd; ++U) {
1038  FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
1039  if (!ConvTemplate)
1040  continue;
1041 
1042  // When we're performing lookup for the purposes of redeclaration, just
1043  // add the conversion function template. When we deduce template
1044  // arguments for specializations, we'll end up unifying the return
1045  // type of the new declaration with the type of the function template.
1046  if (R.isForRedeclaration()) {
1047  R.addDecl(ConvTemplate);
1048  Found = true;
1049  continue;
1050  }
1051 
1052  // C++ [temp.mem]p6:
1053  // [...] For each such operator, if argument deduction succeeds
1054  // (14.9.2.3), the resulting specialization is used as if found by
1055  // name lookup.
1056  //
1057  // When referencing a conversion function for any purpose other than
1058  // a redeclaration (such that we'll be building an expression with the
1059  // result), perform template argument deduction and place the
1060  // specialization into the result set. We do this to avoid forcing all
1061  // callers to perform special deduction for conversion functions.
1063  FunctionDecl *Specialization = nullptr;
1064 
1065  const FunctionProtoType *ConvProto
1066  = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
1067  assert(ConvProto && "Nonsensical conversion function template type");
1068 
1069  // Compute the type of the function that we would expect the conversion
1070  // function to have, if it were to match the name given.
1071  // FIXME: Calling convention!
1073  EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
1074  EPI.ExceptionSpec = EST_None;
1077  None, EPI);
1078 
1079  // Perform template argument deduction against the type that we would
1080  // expect the function to have.
1081  if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
1082  Specialization, Info)
1083  == Sema::TDK_Success) {
1084  R.addDecl(Specialization);
1085  Found = true;
1086  }
1087  }
1088 
1089  return Found;
1090 }
1091 
1092 // Performs C++ unqualified lookup into the given file context.
1093 static bool
1095  DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
1096 
1097  assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
1098 
1099  // Perform direct name lookup into the LookupCtx.
1100  bool Found = LookupDirect(S, R, NS);
1101 
1102  // Perform direct name lookup into the namespaces nominated by the
1103  // using directives whose common ancestor is this namespace.
1104  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
1105  if (LookupDirect(S, R, UUE.getNominatedNamespace()))
1106  Found = true;
1107 
1108  R.resolveKind();
1109 
1110  return Found;
1111 }
1112 
1114  if (DeclContext *Ctx = S->getEntity())
1115  return Ctx->isFileContext();
1116  return false;
1117 }
1118 
1119 // Find the next outer declaration context from this scope. This
1120 // routine actually returns the semantic outer context, which may
1121 // differ from the lexical context (encoded directly in the Scope
1122 // stack) when we are parsing a member of a class template. In this
1123 // case, the second element of the pair will be true, to indicate that
1124 // name lookup should continue searching in this semantic context when
1125 // it leaves the current template parameter scope.
1126 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
1127  DeclContext *DC = S->getEntity();
1128  DeclContext *Lexical = nullptr;
1129  for (Scope *OuterS = S->getParent(); OuterS;
1130  OuterS = OuterS->getParent()) {
1131  if (OuterS->getEntity()) {
1132  Lexical = OuterS->getEntity();
1133  break;
1134  }
1135  }
1136 
1137  // C++ [temp.local]p8:
1138  // In the definition of a member of a class template that appears
1139  // outside of the namespace containing the class template
1140  // definition, the name of a template-parameter hides the name of
1141  // a member of this namespace.
1142  //
1143  // Example:
1144  //
1145  // namespace N {
1146  // class C { };
1147  //
1148  // template<class T> class B {
1149  // void f(T);
1150  // };
1151  // }
1152  //
1153  // template<class C> void N::B<C>::f(C) {
1154  // C b; // C is the template parameter, not N::C
1155  // }
1156  //
1157  // In this example, the lexical context we return is the
1158  // TranslationUnit, while the semantic context is the namespace N.
1159  if (!Lexical || !DC || !S->getParent() ||
1161  return std::make_pair(Lexical, false);
1162 
1163  // Find the outermost template parameter scope.
1164  // For the example, this is the scope for the template parameters of
1165  // template<class C>.
1166  Scope *OutermostTemplateScope = S->getParent();
1167  while (OutermostTemplateScope->getParent() &&
1168  OutermostTemplateScope->getParent()->isTemplateParamScope())
1169  OutermostTemplateScope = OutermostTemplateScope->getParent();
1170 
1171  // Find the namespace context in which the original scope occurs. In
1172  // the example, this is namespace N.
1173  DeclContext *Semantic = DC;
1174  while (!Semantic->isFileContext())
1175  Semantic = Semantic->getParent();
1176 
1177  // Find the declaration context just outside of the template
1178  // parameter scope. This is the context in which the template is
1179  // being lexically declaration (a namespace context). In the
1180  // example, this is the global scope.
1181  if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1182  Lexical->Encloses(Semantic))
1183  return std::make_pair(Semantic, true);
1184 
1185  return std::make_pair(Lexical, false);
1186 }
1187 
1188 namespace {
1189 /// An RAII object to specify that we want to find block scope extern
1190 /// declarations.
1191 struct FindLocalExternScope {
1192  FindLocalExternScope(LookupResult &R)
1193  : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1197  }
1198  void restore() {
1199  R.setFindLocalExtern(OldFindLocalExtern);
1200  }
1201  ~FindLocalExternScope() {
1202  restore();
1203  }
1204  LookupResult &R;
1205  bool OldFindLocalExtern;
1206 };
1207 } // end anonymous namespace
1208 
1209 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1210  assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1211 
1212  DeclarationName Name = R.getLookupName();
1213  Sema::LookupNameKind NameKind = R.getLookupKind();
1214 
1215  // If this is the name of an implicitly-declared special member function,
1216  // go through the scope stack to implicitly declare
1218  for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1219  if (DeclContext *DC = PreS->getEntity())
1220  DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1221  }
1222 
1223  // Implicitly declare member functions with the name we're looking for, if in
1224  // fact we are in a scope where it matters.
1225 
1226  Scope *Initial = S;
1228  I = IdResolver.begin(Name),
1229  IEnd = IdResolver.end();
1230 
1231  // First we lookup local scope.
1232  // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1233  // ...During unqualified name lookup (3.4.1), the names appear as if
1234  // they were declared in the nearest enclosing namespace which contains
1235  // both the using-directive and the nominated namespace.
1236  // [Note: in this context, "contains" means "contains directly or
1237  // indirectly".
1238  //
1239  // For example:
1240  // namespace A { int i; }
1241  // void foo() {
1242  // int i;
1243  // {
1244  // using namespace A;
1245  // ++i; // finds local 'i', A::i appears at global scope
1246  // }
1247  // }
1248  //
1249  UnqualUsingDirectiveSet UDirs(*this);
1250  bool VisitedUsingDirectives = false;
1251  bool LeftStartingScope = false;
1252  DeclContext *OutsideOfTemplateParamDC = nullptr;
1253 
1254  // When performing a scope lookup, we want to find local extern decls.
1255  FindLocalExternScope FindLocals(R);
1256 
1257  for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1258  DeclContext *Ctx = S->getEntity();
1259  bool SearchNamespaceScope = true;
1260  // Check whether the IdResolver has anything in this scope.
1261  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1262  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1263  if (NameKind == LookupRedeclarationWithLinkage &&
1264  !(*I)->isTemplateParameter()) {
1265  // If it's a template parameter, we still find it, so we can diagnose
1266  // the invalid redeclaration.
1267 
1268  // Determine whether this (or a previous) declaration is
1269  // out-of-scope.
1270  if (!LeftStartingScope && !Initial->isDeclScope(*I))
1271  LeftStartingScope = true;
1272 
1273  // If we found something outside of our starting scope that
1274  // does not have linkage, skip it.
1275  if (LeftStartingScope && !((*I)->hasLinkage())) {
1276  R.setShadowed();
1277  continue;
1278  }
1279  } else {
1280  // We found something in this scope, we should not look at the
1281  // namespace scope
1282  SearchNamespaceScope = false;
1283  }
1284  R.addDecl(ND);
1285  }
1286  }
1287  if (!SearchNamespaceScope) {
1288  R.resolveKind();
1289  if (S->isClassScope())
1290  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1291  R.setNamingClass(Record);
1292  return true;
1293  }
1294 
1295  if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1296  // C++11 [class.friend]p11:
1297  // If a friend declaration appears in a local class and the name
1298  // specified is an unqualified name, a prior declaration is
1299  // looked up without considering scopes that are outside the
1300  // innermost enclosing non-class scope.
1301  return false;
1302  }
1303 
1304  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1305  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1306  // We've just searched the last template parameter scope and
1307  // found nothing, so look into the contexts between the
1308  // lexical and semantic declaration contexts returned by
1309  // findOuterContext(). This implements the name lookup behavior
1310  // of C++ [temp.local]p8.
1311  Ctx = OutsideOfTemplateParamDC;
1312  OutsideOfTemplateParamDC = nullptr;
1313  }
1314 
1315  if (Ctx) {
1316  DeclContext *OuterCtx;
1317  bool SearchAfterTemplateScope;
1318  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1319  if (SearchAfterTemplateScope)
1320  OutsideOfTemplateParamDC = OuterCtx;
1321 
1322  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1323  // We do not directly look into transparent contexts, since
1324  // those entities will be found in the nearest enclosing
1325  // non-transparent context.
1326  if (Ctx->isTransparentContext())
1327  continue;
1328 
1329  // We do not look directly into function or method contexts,
1330  // since all of the local variables and parameters of the
1331  // function/method are present within the Scope.
1332  if (Ctx->isFunctionOrMethod()) {
1333  // If we have an Objective-C instance method, look for ivars
1334  // in the corresponding interface.
1335  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1336  if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1337  if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1338  ObjCInterfaceDecl *ClassDeclared;
1339  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1340  Name.getAsIdentifierInfo(),
1341  ClassDeclared)) {
1342  if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1343  R.addDecl(ND);
1344  R.resolveKind();
1345  return true;
1346  }
1347  }
1348  }
1349  }
1350 
1351  continue;
1352  }
1353 
1354  // If this is a file context, we need to perform unqualified name
1355  // lookup considering using directives.
1356  if (Ctx->isFileContext()) {
1357  // If we haven't handled using directives yet, do so now.
1358  if (!VisitedUsingDirectives) {
1359  // Add using directives from this context up to the top level.
1360  for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1361  if (UCtx->isTransparentContext())
1362  continue;
1363 
1364  UDirs.visit(UCtx, UCtx);
1365  }
1366 
1367  // Find the innermost file scope, so we can add using directives
1368  // from local scopes.
1369  Scope *InnermostFileScope = S;
1370  while (InnermostFileScope &&
1371  !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1372  InnermostFileScope = InnermostFileScope->getParent();
1373  UDirs.visitScopeChain(Initial, InnermostFileScope);
1374 
1375  UDirs.done();
1376 
1377  VisitedUsingDirectives = true;
1378  }
1379 
1380  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1381  R.resolveKind();
1382  return true;
1383  }
1384 
1385  continue;
1386  }
1387 
1388  // Perform qualified name lookup into this context.
1389  // FIXME: In some cases, we know that every name that could be found by
1390  // this qualified name lookup will also be on the identifier chain. For
1391  // example, inside a class without any base classes, we never need to
1392  // perform qualified lookup because all of the members are on top of the
1393  // identifier chain.
1394  if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1395  return true;
1396  }
1397  }
1398  }
1399 
1400  // Stop if we ran out of scopes.
1401  // FIXME: This really, really shouldn't be happening.
1402  if (!S) return false;
1403 
1404  // If we are looking for members, no need to look into global/namespace scope.
1405  if (NameKind == LookupMemberName)
1406  return false;
1407 
1408  // Collect UsingDirectiveDecls in all scopes, and recursively all
1409  // nominated namespaces by those using-directives.
1410  //
1411  // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1412  // don't build it for each lookup!
1413  if (!VisitedUsingDirectives) {
1414  UDirs.visitScopeChain(Initial, S);
1415  UDirs.done();
1416  }
1417 
1418  // If we're not performing redeclaration lookup, do not look for local
1419  // extern declarations outside of a function scope.
1420  if (!R.isForRedeclaration())
1421  FindLocals.restore();
1422 
1423  // Lookup namespace scope, and global scope.
1424  // Unqualified name lookup in C++ requires looking into scopes
1425  // that aren't strictly lexical, and therefore we walk through the
1426  // context as well as walking through the scopes.
1427  for (; S; S = S->getParent()) {
1428  // Check whether the IdResolver has anything in this scope.
1429  bool Found = false;
1430  for (; I != IEnd && S->isDeclScope(*I); ++I) {
1431  if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1432  // We found something. Look for anything else in our scope
1433  // with this same name and in an acceptable identifier
1434  // namespace, so that we can construct an overload set if we
1435  // need to.
1436  Found = true;
1437  R.addDecl(ND);
1438  }
1439  }
1440 
1441  if (Found && S->isTemplateParamScope()) {
1442  R.resolveKind();
1443  return true;
1444  }
1445 
1446  DeclContext *Ctx = S->getEntity();
1447  if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1448  S->getParent() && !S->getParent()->isTemplateParamScope()) {
1449  // We've just searched the last template parameter scope and
1450  // found nothing, so look into the contexts between the
1451  // lexical and semantic declaration contexts returned by
1452  // findOuterContext(). This implements the name lookup behavior
1453  // of C++ [temp.local]p8.
1454  Ctx = OutsideOfTemplateParamDC;
1455  OutsideOfTemplateParamDC = nullptr;
1456  }
1457 
1458  if (Ctx) {
1459  DeclContext *OuterCtx;
1460  bool SearchAfterTemplateScope;
1461  std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1462  if (SearchAfterTemplateScope)
1463  OutsideOfTemplateParamDC = OuterCtx;
1464 
1465  for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1466  // We do not directly look into transparent contexts, since
1467  // those entities will be found in the nearest enclosing
1468  // non-transparent context.
1469  if (Ctx->isTransparentContext())
1470  continue;
1471 
1472  // If we have a context, and it's not a context stashed in the
1473  // template parameter scope for an out-of-line definition, also
1474  // look into that context.
1475  if (!(Found && S->isTemplateParamScope())) {
1476  assert(Ctx->isFileContext() &&
1477  "We should have been looking only at file context here already.");
1478 
1479  // Look into context considering using-directives.
1480  if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1481  Found = true;
1482  }
1483 
1484  if (Found) {
1485  R.resolveKind();
1486  return true;
1487  }
1488 
1489  if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1490  return false;
1491  }
1492  }
1493 
1494  if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1495  return false;
1496  }
1497 
1498  return !R.empty();
1499 }
1500 
1502  if (auto *M = getCurrentModule())
1503  Context.mergeDefinitionIntoModule(ND, M);
1504  else
1505  // We're not building a module; just make the definition visible.
1507 
1508  // If ND is a template declaration, make the template parameters
1509  // visible too. They're not (necessarily) within a mergeable DeclContext.
1510  if (auto *TD = dyn_cast<TemplateDecl>(ND))
1511  for (auto *Param : *TD->getTemplateParameters())
1512  makeMergedDefinitionVisible(Param);
1513 }
1514 
1515 /// Find the module in which the given declaration was defined.
1516 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1517  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1518  // If this function was instantiated from a template, the defining module is
1519  // the module containing the pattern.
1520  if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1521  Entity = Pattern;
1522  } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1523  if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1524  Entity = Pattern;
1525  } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1526  if (auto *Pattern = ED->getTemplateInstantiationPattern())
1527  Entity = Pattern;
1528  } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1529  if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1530  Entity = Pattern;
1531  }
1532 
1533  // Walk up to the containing context. That might also have been instantiated
1534  // from a template.
1535  DeclContext *Context = Entity->getLexicalDeclContext();
1536  if (Context->isFileContext())
1537  return S.getOwningModule(Entity);
1538  return getDefiningModule(S, cast<Decl>(Context));
1539 }
1540 
1542  unsigned N = CodeSynthesisContexts.size();
1543  for (unsigned I = CodeSynthesisContextLookupModules.size();
1544  I != N; ++I) {
1545  Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1546  if (M && !LookupModulesCache.insert(M).second)
1547  M = nullptr;
1548  CodeSynthesisContextLookupModules.push_back(M);
1549  }
1550  return LookupModulesCache;
1551 }
1552 
1553 /// Determine whether the module M is part of the current module from the
1554 /// perspective of a module-private visibility check.
1555 static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts) {
1556  // If M is the global module fragment of a module that we've not yet finished
1557  // parsing, then it must be part of the current module.
1558  return M->getTopLevelModuleName() == LangOpts.CurrentModule ||
1559  (M->Kind == Module::GlobalModuleFragment && !M->Parent);
1560 }
1561 
1563  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1564  if (isModuleVisible(Merged))
1565  return true;
1566  return false;
1567 }
1568 
1570  for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1571  if (isInCurrentModule(Merged, getLangOpts()))
1572  return true;
1573  return false;
1574 }
1575 
1576 template<typename ParmDecl>
1577 static bool
1578 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1580  if (!D->hasDefaultArgument())
1581  return false;
1582 
1583  while (D) {
1584  auto &DefaultArg = D->getDefaultArgStorage();
1585  if (!DefaultArg.isInherited() && S.isVisible(D))
1586  return true;
1587 
1588  if (!DefaultArg.isInherited() && Modules) {
1589  auto *NonConstD = const_cast<ParmDecl*>(D);
1590  Modules->push_back(S.getOwningModule(NonConstD));
1591  }
1592 
1593  // If there was a previous default argument, maybe its parameter is visible.
1594  D = DefaultArg.getInheritedFrom();
1595  }
1596  return false;
1597 }
1598 
1601  if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1602  return ::hasVisibleDefaultArgument(*this, P, Modules);
1603  if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1604  return ::hasVisibleDefaultArgument(*this, P, Modules);
1605  return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1606  Modules);
1607 }
1608 
1609 template<typename Filter>
1610 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1612  Filter F) {
1613  bool HasFilteredRedecls = false;
1614 
1615  for (auto *Redecl : D->redecls()) {
1616  auto *R = cast<NamedDecl>(Redecl);
1617  if (!F(R))
1618  continue;
1619 
1620  if (S.isVisible(R))
1621  return true;
1622 
1623  HasFilteredRedecls = true;
1624 
1625  if (Modules)
1626  Modules->push_back(R->getOwningModule());
1627  }
1628 
1629  // Only return false if there is at least one redecl that is not filtered out.
1630  if (HasFilteredRedecls)
1631  return false;
1632 
1633  return true;
1634 }
1635 
1637  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1638  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1639  if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1640  return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1641  if (auto *FD = dyn_cast<FunctionDecl>(D))
1642  return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1643  if (auto *VD = dyn_cast<VarDecl>(D))
1644  return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1645  llvm_unreachable("unknown explicit specialization kind");
1646  });
1647 }
1648 
1650  const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1651  assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1652  "not a member specialization");
1653  return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1654  // If the specialization is declared at namespace scope, then it's a member
1655  // specialization declaration. If it's lexically inside the class
1656  // definition then it was instantiated.
1657  //
1658  // FIXME: This is a hack. There should be a better way to determine this.
1659  // FIXME: What about MS-style explicit specializations declared within a
1660  // class definition?
1661  return D->getLexicalDeclContext()->isFileContext();
1662  });
1663 }
1664 
1665 /// Determine whether a declaration is visible to name lookup.
1666 ///
1667 /// This routine determines whether the declaration D is visible in the current
1668 /// lookup context, taking into account the current template instantiation
1669 /// stack. During template instantiation, a declaration is visible if it is
1670 /// visible from a module containing any entity on the template instantiation
1671 /// path (by instantiating a template, you allow it to see the declarations that
1672 /// your module can see, including those later on in your module).
1673 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1674  assert(D->isHidden() && "should not call this: not in slow case");
1675 
1676  Module *DeclModule = SemaRef.getOwningModule(D);
1677  assert(DeclModule && "hidden decl has no owning module");
1678 
1679  // If the owning module is visible, the decl is visible.
1680  if (SemaRef.isModuleVisible(DeclModule, D->isModulePrivate()))
1681  return true;
1682 
1683  // Determine whether a decl context is a file context for the purpose of
1684  // visibility. This looks through some (export and linkage spec) transparent
1685  // contexts, but not others (enums).
1686  auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1687  return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1688  isa<ExportDecl>(DC);
1689  };
1690 
1691  // If this declaration is not at namespace scope
1692  // then it is visible if its lexical parent has a visible definition.
1694  if (DC && !IsEffectivelyFileContext(DC)) {
1695  // For a parameter, check whether our current template declaration's
1696  // lexical context is visible, not whether there's some other visible
1697  // definition of it, because parameters aren't "within" the definition.
1698  //
1699  // In C++ we need to check for a visible definition due to ODR merging,
1700  // and in C we must not because each declaration of a function gets its own
1701  // set of declarations for tags in prototype scope.
1702  bool VisibleWithinParent;
1703  if (D->isTemplateParameter()) {
1704  bool SearchDefinitions = true;
1705  if (const auto *DCD = dyn_cast<Decl>(DC)) {
1706  if (const auto *TD = DCD->getDescribedTemplate()) {
1707  TemplateParameterList *TPL = TD->getTemplateParameters();
1708  auto Index = getDepthAndIndex(D).second;
1709  SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D;
1710  }
1711  }
1712  if (SearchDefinitions)
1713  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1714  else
1715  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1716  } else if (isa<ParmVarDecl>(D) ||
1717  (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1718  VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1719  else if (D->isModulePrivate()) {
1720  // A module-private declaration is only visible if an enclosing lexical
1721  // parent was merged with another definition in the current module.
1722  VisibleWithinParent = false;
1723  do {
1724  if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1725  VisibleWithinParent = true;
1726  break;
1727  }
1728  DC = DC->getLexicalParent();
1729  } while (!IsEffectivelyFileContext(DC));
1730  } else {
1731  VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1732  }
1733 
1734  if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1735  // FIXME: Do something better in this case.
1736  !SemaRef.getLangOpts().ModulesLocalVisibility) {
1737  // Cache the fact that this declaration is implicitly visible because
1738  // its parent has a visible definition.
1740  }
1741  return VisibleWithinParent;
1742  }
1743 
1744  return false;
1745 }
1746 
1747 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1748  // The module might be ordinarily visible. For a module-private query, that
1749  // means it is part of the current module. For any other query, that means it
1750  // is in our visible module set.
1751  if (ModulePrivate) {
1752  if (isInCurrentModule(M, getLangOpts()))
1753  return true;
1754  } else {
1755  if (VisibleModules.isVisible(M))
1756  return true;
1757  }
1758 
1759  // Otherwise, it might be visible by virtue of the query being within a
1760  // template instantiation or similar that is permitted to look inside M.
1761 
1762  // Find the extra places where we need to look.
1763  const auto &LookupModules = getLookupModules();
1764  if (LookupModules.empty())
1765  return false;
1766 
1767  // If our lookup set contains the module, it's visible.
1768  if (LookupModules.count(M))
1769  return true;
1770 
1771  // For a module-private query, that's everywhere we get to look.
1772  if (ModulePrivate)
1773  return false;
1774 
1775  // Check whether M is transitively exported to an import of the lookup set.
1776  return llvm::any_of(LookupModules, [&](const Module *LookupM) {
1777  return LookupM->isModuleVisible(M);
1778  });
1779 }
1780 
1781 bool Sema::isVisibleSlow(const NamedDecl *D) {
1782  return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1783 }
1784 
1785 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1786  // FIXME: If there are both visible and hidden declarations, we need to take
1787  // into account whether redeclaration is possible. Example:
1788  //
1789  // Non-imported module:
1790  // int f(T); // #1
1791  // Some TU:
1792  // static int f(U); // #2, not a redeclaration of #1
1793  // int f(T); // #3, finds both, should link with #1 if T != U, but
1794  // // with #2 if T == U; neither should be ambiguous.
1795  for (auto *D : R) {
1796  if (isVisible(D))
1797  return true;
1798  assert(D->isExternallyDeclarable() &&
1799  "should not have hidden, non-externally-declarable result here");
1800  }
1801 
1802  // This function is called once "New" is essentially complete, but before a
1803  // previous declaration is attached. We can't query the linkage of "New" in
1804  // general, because attaching the previous declaration can change the
1805  // linkage of New to match the previous declaration.
1806  //
1807  // However, because we've just determined that there is no *visible* prior
1808  // declaration, we can compute the linkage here. There are two possibilities:
1809  //
1810  // * This is not a redeclaration; it's safe to compute the linkage now.
1811  //
1812  // * This is a redeclaration of a prior declaration that is externally
1813  // redeclarable. In that case, the linkage of the declaration is not
1814  // changed by attaching the prior declaration, because both are externally
1815  // declarable (and thus ExternalLinkage or VisibleNoLinkage).
1816  //
1817  // FIXME: This is subtle and fragile.
1818  return New->isExternallyDeclarable();
1819 }
1820 
1821 /// Retrieve the visible declaration corresponding to D, if any.
1822 ///
1823 /// This routine determines whether the declaration D is visible in the current
1824 /// module, with the current imports. If not, it checks whether any
1825 /// redeclaration of D is visible, and if so, returns that declaration.
1826 ///
1827 /// \returns D, or a visible previous declaration of D, whichever is more recent
1828 /// and visible. If no declaration of D is visible, returns null.
1830  unsigned IDNS) {
1831  assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1832 
1833  for (auto RD : D->redecls()) {
1834  // Don't bother with extra checks if we already know this one isn't visible.
1835  if (RD == D)
1836  continue;
1837 
1838  auto ND = cast<NamedDecl>(RD);
1839  // FIXME: This is wrong in the case where the previous declaration is not
1840  // visible in the same scope as D. This needs to be done much more
1841  // carefully.
1842  if (ND->isInIdentifierNamespace(IDNS) &&
1843  LookupResult::isVisible(SemaRef, ND))
1844  return ND;
1845  }
1846 
1847  return nullptr;
1848 }
1849 
1852  assert(!isVisible(D) && "not in slow case");
1853  return hasVisibleDeclarationImpl(*this, D, Modules,
1854  [](const NamedDecl *) { return true; });
1855 }
1856 
1857 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1858  if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1859  // Namespaces are a bit of a special case: we expect there to be a lot of
1860  // redeclarations of some namespaces, all declarations of a namespace are
1861  // essentially interchangeable, all declarations are found by name lookup
1862  // if any is, and namespaces are never looked up during template
1863  // instantiation. So we benefit from caching the check in this case, and
1864  // it is correct to do so.
1865  auto *Key = ND->getCanonicalDecl();
1866  if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1867  return Acceptable;
1868  auto *Acceptable = isVisible(getSema(), Key)
1869  ? Key
1870  : findAcceptableDecl(getSema(), Key, IDNS);
1871  if (Acceptable)
1872  getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1873  return Acceptable;
1874  }
1875 
1876  return findAcceptableDecl(getSema(), D, IDNS);
1877 }
1878 
1879 /// Perform unqualified name lookup starting from a given
1880 /// scope.
1881 ///
1882 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1883 /// used to find names within the current scope. For example, 'x' in
1884 /// @code
1885 /// int x;
1886 /// int f() {
1887 /// return x; // unqualified name look finds 'x' in the global scope
1888 /// }
1889 /// @endcode
1890 ///
1891 /// Different lookup criteria can find different names. For example, a
1892 /// particular scope can have both a struct and a function of the same
1893 /// name, and each can be found by certain lookup criteria. For more
1894 /// information about lookup criteria, see the documentation for the
1895 /// class LookupCriteria.
1896 ///
1897 /// @param S The scope from which unqualified name lookup will
1898 /// begin. If the lookup criteria permits, name lookup may also search
1899 /// in the parent scopes.
1900 ///
1901 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1902 /// look up and the lookup kind), and is updated with the results of lookup
1903 /// including zero or more declarations and possibly additional information
1904 /// used to diagnose ambiguities.
1905 ///
1906 /// @returns \c true if lookup succeeded and false otherwise.
1907 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1908  DeclarationName Name = R.getLookupName();
1909  if (!Name) return false;
1910 
1911  LookupNameKind NameKind = R.getLookupKind();
1912 
1913  if (!getLangOpts().CPlusPlus) {
1914  // Unqualified name lookup in C/Objective-C is purely lexical, so
1915  // search in the declarations attached to the name.
1916  if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1917  // Find the nearest non-transparent declaration scope.
1918  while (!(S->getFlags() & Scope::DeclScope) ||
1919  (S->getEntity() && S->getEntity()->isTransparentContext()))
1920  S = S->getParent();
1921  }
1922 
1923  // When performing a scope lookup, we want to find local extern decls.
1924  FindLocalExternScope FindLocals(R);
1925 
1926  // Scan up the scope chain looking for a decl that matches this
1927  // identifier that is in the appropriate namespace. This search
1928  // should not take long, as shadowing of names is uncommon, and
1929  // deep shadowing is extremely uncommon.
1930  bool LeftStartingScope = false;
1931 
1932  for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1933  IEnd = IdResolver.end();
1934  I != IEnd; ++I)
1935  if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1936  if (NameKind == LookupRedeclarationWithLinkage) {
1937  // Determine whether this (or a previous) declaration is
1938  // out-of-scope.
1939  if (!LeftStartingScope && !S->isDeclScope(*I))
1940  LeftStartingScope = true;
1941 
1942  // If we found something outside of our starting scope that
1943  // does not have linkage, skip it.
1944  if (LeftStartingScope && !((*I)->hasLinkage())) {
1945  R.setShadowed();
1946  continue;
1947  }
1948  }
1949  else if (NameKind == LookupObjCImplicitSelfParam &&
1950  !isa<ImplicitParamDecl>(*I))
1951  continue;
1952 
1953  R.addDecl(D);
1954 
1955  // Check whether there are any other declarations with the same name
1956  // and in the same scope.
1957  if (I != IEnd) {
1958  // Find the scope in which this declaration was declared (if it
1959  // actually exists in a Scope).
1960  while (S && !S->isDeclScope(D))
1961  S = S->getParent();
1962 
1963  // If the scope containing the declaration is the translation unit,
1964  // then we'll need to perform our checks based on the matching
1965  // DeclContexts rather than matching scopes.
1967  S = nullptr;
1968 
1969  // Compute the DeclContext, if we need it.
1970  DeclContext *DC = nullptr;
1971  if (!S)
1972  DC = (*I)->getDeclContext()->getRedeclContext();
1973 
1974  IdentifierResolver::iterator LastI = I;
1975  for (++LastI; LastI != IEnd; ++LastI) {
1976  if (S) {
1977  // Match based on scope.
1978  if (!S->isDeclScope(*LastI))
1979  break;
1980  } else {
1981  // Match based on DeclContext.
1982  DeclContext *LastDC
1983  = (*LastI)->getDeclContext()->getRedeclContext();
1984  if (!LastDC->Equals(DC))
1985  break;
1986  }
1987 
1988  // If the declaration is in the right namespace and visible, add it.
1989  if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1990  R.addDecl(LastD);
1991  }
1992 
1993  R.resolveKind();
1994  }
1995 
1996  return true;
1997  }
1998  } else {
1999  // Perform C++ unqualified name lookup.
2000  if (CppLookupName(R, S))
2001  return true;
2002  }
2003 
2004  // If we didn't find a use of this identifier, and if the identifier
2005  // corresponds to a compiler builtin, create the decl object for the builtin
2006  // now, injecting it into translation unit scope, and return it.
2007  if (AllowBuiltinCreation && LookupBuiltin(*this, R))
2008  return true;
2009 
2010  // If we didn't find a use of this identifier, the ExternalSource
2011  // may be able to handle the situation.
2012  // Note: some lookup failures are expected!
2013  // See e.g. R.isForRedeclaration().
2014  return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
2015 }
2016 
2017 /// Perform qualified name lookup in the namespaces nominated by
2018 /// using directives by the given context.
2019 ///
2020 /// C++98 [namespace.qual]p2:
2021 /// Given X::m (where X is a user-declared namespace), or given \::m
2022 /// (where X is the global namespace), let S be the set of all
2023 /// declarations of m in X and in the transitive closure of all
2024 /// namespaces nominated by using-directives in X and its used
2025 /// namespaces, except that using-directives are ignored in any
2026 /// namespace, including X, directly containing one or more
2027 /// declarations of m. No namespace is searched more than once in
2028 /// the lookup of a name. If S is the empty set, the program is
2029 /// ill-formed. Otherwise, if S has exactly one member, or if the
2030 /// context of the reference is a using-declaration
2031 /// (namespace.udecl), S is the required set of declarations of
2032 /// m. Otherwise if the use of m is not one that allows a unique
2033 /// declaration to be chosen from S, the program is ill-formed.
2034 ///
2035 /// C++98 [namespace.qual]p5:
2036 /// During the lookup of a qualified namespace member name, if the
2037 /// lookup finds more than one declaration of the member, and if one
2038 /// declaration introduces a class name or enumeration name and the
2039 /// other declarations either introduce the same object, the same
2040 /// enumerator or a set of functions, the non-type name hides the
2041 /// class or enumeration name if and only if the declarations are
2042 /// from the same namespace; otherwise (the declarations are from
2043 /// different namespaces), the program is ill-formed.
2045  DeclContext *StartDC) {
2046  assert(StartDC->isFileContext() && "start context is not a file context");
2047 
2048  // We have not yet looked into these namespaces, much less added
2049  // their "using-children" to the queue.
2051 
2052  // We have at least added all these contexts to the queue.
2053  llvm::SmallPtrSet<DeclContext*, 8> Visited;
2054  Visited.insert(StartDC);
2055 
2056  // We have already looked into the initial namespace; seed the queue
2057  // with its using-children.
2058  for (auto *I : StartDC->using_directives()) {
2059  NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
2060  if (S.isVisible(I) && Visited.insert(ND).second)
2061  Queue.push_back(ND);
2062  }
2063 
2064  // The easiest way to implement the restriction in [namespace.qual]p5
2065  // is to check whether any of the individual results found a tag
2066  // and, if so, to declare an ambiguity if the final result is not
2067  // a tag.
2068  bool FoundTag = false;
2069  bool FoundNonTag = false;
2070 
2072 
2073  bool Found = false;
2074  while (!Queue.empty()) {
2075  NamespaceDecl *ND = Queue.pop_back_val();
2076 
2077  // We go through some convolutions here to avoid copying results
2078  // between LookupResults.
2079  bool UseLocal = !R.empty();
2080  LookupResult &DirectR = UseLocal ? LocalR : R;
2081  bool FoundDirect = LookupDirect(S, DirectR, ND);
2082 
2083  if (FoundDirect) {
2084  // First do any local hiding.
2085  DirectR.resolveKind();
2086 
2087  // If the local result is a tag, remember that.
2088  if (DirectR.isSingleTagDecl())
2089  FoundTag = true;
2090  else
2091  FoundNonTag = true;
2092 
2093  // Append the local results to the total results if necessary.
2094  if (UseLocal) {
2095  R.addAllDecls(LocalR);
2096  LocalR.clear();
2097  }
2098  }
2099 
2100  // If we find names in this namespace, ignore its using directives.
2101  if (FoundDirect) {
2102  Found = true;
2103  continue;
2104  }
2105 
2106  for (auto I : ND->using_directives()) {
2107  NamespaceDecl *Nom = I->getNominatedNamespace();
2108  if (S.isVisible(I) && Visited.insert(Nom).second)
2109  Queue.push_back(Nom);
2110  }
2111  }
2112 
2113  if (Found) {
2114  if (FoundTag && FoundNonTag)
2116  else
2117  R.resolveKind();
2118  }
2119 
2120  return Found;
2121 }
2122 
2123 /// Callback that looks for any member of a class with the given name.
2125  CXXBasePath &Path, DeclarationName Name) {
2126  RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
2127 
2128  Path.Decls = BaseRecord->lookup(Name);
2129  return !Path.Decls.empty();
2130 }
2131 
2132 /// Determine whether the given set of member declarations contains only
2133 /// static members, nested types, and enumerators.
2134 template<typename InputIterator>
2135 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
2136  Decl *D = (*First)->getUnderlyingDecl();
2137  if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
2138  return true;
2139 
2140  if (isa<CXXMethodDecl>(D)) {
2141  // Determine whether all of the methods are static.
2142  bool AllMethodsAreStatic = true;
2143  for(; First != Last; ++First) {
2144  D = (*First)->getUnderlyingDecl();
2145 
2146  if (!isa<CXXMethodDecl>(D)) {
2147  assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
2148  break;
2149  }
2150 
2151  if (!cast<CXXMethodDecl>(D)->isStatic()) {
2152  AllMethodsAreStatic = false;
2153  break;
2154  }
2155  }
2156 
2157  if (AllMethodsAreStatic)
2158  return true;
2159  }
2160 
2161  return false;
2162 }
2163 
2164 /// Perform qualified name lookup into a given context.
2165 ///
2166 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
2167 /// names when the context of those names is explicit specified, e.g.,
2168 /// "std::vector" or "x->member", or as part of unqualified name lookup.
2169 ///
2170 /// Different lookup criteria can find different names. For example, a
2171 /// particular scope can have both a struct and a function of the same
2172 /// name, and each can be found by certain lookup criteria. For more
2173 /// information about lookup criteria, see the documentation for the
2174 /// class LookupCriteria.
2175 ///
2176 /// \param R captures both the lookup criteria and any lookup results found.
2177 ///
2178 /// \param LookupCtx The context in which qualified name lookup will
2179 /// search. If the lookup criteria permits, name lookup may also search
2180 /// in the parent contexts or (for C++ classes) base classes.
2181 ///
2182 /// \param InUnqualifiedLookup true if this is qualified name lookup that
2183 /// occurs as part of unqualified name lookup.
2184 ///
2185 /// \returns true if lookup succeeded, false if it failed.
2187  bool InUnqualifiedLookup) {
2188  assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2189 
2190  if (!R.getLookupName())
2191  return false;
2192 
2193  // Make sure that the declaration context is complete.
2194  assert((!isa<TagDecl>(LookupCtx) ||
2195  LookupCtx->isDependentContext() ||
2196  cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
2197  cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
2198  "Declaration context must already be complete!");
2199 
2200  struct QualifiedLookupInScope {
2201  bool oldVal;
2202  DeclContext *Context;
2203  // Set flag in DeclContext informing debugger that we're looking for qualified name
2204  QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2205  oldVal = ctx->setUseQualifiedLookup();
2206  }
2207  ~QualifiedLookupInScope() {
2208  Context->setUseQualifiedLookup(oldVal);
2209  }
2210  } QL(LookupCtx);
2211 
2212  if (LookupDirect(*this, R, LookupCtx)) {
2213  R.resolveKind();
2214  if (isa<CXXRecordDecl>(LookupCtx))
2215  R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2216  return true;
2217  }
2218 
2219  // Don't descend into implied contexts for redeclarations.
2220  // C++98 [namespace.qual]p6:
2221  // In a declaration for a namespace member in which the
2222  // declarator-id is a qualified-id, given that the qualified-id
2223  // for the namespace member has the form
2224  // nested-name-specifier unqualified-id
2225  // the unqualified-id shall name a member of the namespace
2226  // designated by the nested-name-specifier.
2227  // See also [class.mfct]p5 and [class.static.data]p2.
2228  if (R.isForRedeclaration())
2229  return false;
2230 
2231  // If this is a namespace, look it up in the implied namespaces.
2232  if (LookupCtx->isFileContext())
2233  return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2234 
2235  // If this isn't a C++ class, we aren't allowed to look into base
2236  // classes, we're done.
2237  CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2238  if (!LookupRec || !LookupRec->getDefinition())
2239  return false;
2240 
2241  // If we're performing qualified name lookup into a dependent class,
2242  // then we are actually looking into a current instantiation. If we have any
2243  // dependent base classes, then we either have to delay lookup until
2244  // template instantiation time (at which point all bases will be available)
2245  // or we have to fail.
2246  if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2247  LookupRec->hasAnyDependentBases()) {
2249  return false;
2250  }
2251 
2252  // Perform lookup into our base classes.
2253  CXXBasePaths Paths;
2254  Paths.setOrigin(LookupRec);
2255 
2256  // Look for this member in our base classes
2257  bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2258  DeclarationName Name) = nullptr;
2259  switch (R.getLookupKind()) {
2260  case LookupObjCImplicitSelfParam:
2261  case LookupOrdinaryName:
2262  case LookupMemberName:
2263  case LookupRedeclarationWithLinkage:
2264  case LookupLocalFriendName:
2265  BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2266  break;
2267 
2268  case LookupTagName:
2269  BaseCallback = &CXXRecordDecl::FindTagMember;
2270  break;
2271 
2272  case LookupAnyName:
2273  BaseCallback = &LookupAnyMember;
2274  break;
2275 
2276  case LookupOMPReductionName:
2277  BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2278  break;
2279 
2280  case LookupOMPMapperName:
2281  BaseCallback = &CXXRecordDecl::FindOMPMapperMember;
2282  break;
2283 
2284  case LookupUsingDeclName:
2285  // This lookup is for redeclarations only.
2286 
2287  case LookupOperatorName:
2288  case LookupNamespaceName:
2289  case LookupObjCProtocolName:
2290  case LookupLabel:
2291  // These lookups will never find a member in a C++ class (or base class).
2292  return false;
2293 
2294  case LookupNestedNameSpecifierName:
2296  break;
2297  }
2298 
2299  DeclarationName Name = R.getLookupName();
2300  if (!LookupRec->lookupInBases(
2301  [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2302  return BaseCallback(Specifier, Path, Name);
2303  },
2304  Paths))
2305  return false;
2306 
2307  R.setNamingClass(LookupRec);
2308 
2309  // C++ [class.member.lookup]p2:
2310  // [...] If the resulting set of declarations are not all from
2311  // sub-objects of the same type, or the set has a nonstatic member
2312  // and includes members from distinct sub-objects, there is an
2313  // ambiguity and the program is ill-formed. Otherwise that set is
2314  // the result of the lookup.
2315  QualType SubobjectType;
2316  int SubobjectNumber = 0;
2317  AccessSpecifier SubobjectAccess = AS_none;
2318 
2319  for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2320  Path != PathEnd; ++Path) {
2321  const CXXBasePathElement &PathElement = Path->back();
2322 
2323  // Pick the best (i.e. most permissive i.e. numerically lowest) access
2324  // across all paths.
2325  SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2326 
2327  // Determine whether we're looking at a distinct sub-object or not.
2328  if (SubobjectType.isNull()) {
2329  // This is the first subobject we've looked at. Record its type.
2330  SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2331  SubobjectNumber = PathElement.SubobjectNumber;
2332  continue;
2333  }
2334 
2335  if (SubobjectType
2336  != Context.getCanonicalType(PathElement.Base->getType())) {
2337  // We found members of the given name in two subobjects of
2338  // different types. If the declaration sets aren't the same, this
2339  // lookup is ambiguous.
2340  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2341  CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2342  DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2343  DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2344 
2345  // Get the decl that we should use for deduplicating this lookup.
2346  auto GetRepresentativeDecl = [&](NamedDecl *D) -> Decl * {
2347  // C++ [temp.local]p3:
2348  // A lookup that finds an injected-class-name (10.2) can result in
2349  // an ambiguity in certain cases (for example, if it is found in
2350  // more than one base class). If all of the injected-class-names
2351  // that are found refer to specializations of the same class
2352  // template, and if the name is used as a template-name, the
2353  // reference refers to the class template itself and not a
2354  // specialization thereof, and is not ambiguous.
2355  if (R.isTemplateNameLookup())
2356  if (auto *TD = getAsTemplateNameDecl(D))
2357  D = TD;
2358  return D->getUnderlyingDecl()->getCanonicalDecl();
2359  };
2360 
2361  while (FirstD != FirstPath->Decls.end() &&
2362  CurrentD != Path->Decls.end()) {
2363  if (GetRepresentativeDecl(*FirstD) !=
2364  GetRepresentativeDecl(*CurrentD))
2365  break;
2366 
2367  ++FirstD;
2368  ++CurrentD;
2369  }
2370 
2371  if (FirstD == FirstPath->Decls.end() &&
2372  CurrentD == Path->Decls.end())
2373  continue;
2374  }
2375 
2377  return true;
2378  }
2379 
2380  if (SubobjectNumber != PathElement.SubobjectNumber) {
2381  // We have a different subobject of the same type.
2382 
2383  // C++ [class.member.lookup]p5:
2384  // A static member, a nested type or an enumerator defined in
2385  // a base class T can unambiguously be found even if an object
2386  // has more than one base class subobject of type T.
2387  if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2388  continue;
2389 
2390  // We have found a nonstatic member name in multiple, distinct
2391  // subobjects. Name lookup is ambiguous.
2392  R.setAmbiguousBaseSubobjects(Paths);
2393  return true;
2394  }
2395  }
2396 
2397  // Lookup in a base class succeeded; return these results.
2398 
2399  for (auto *D : Paths.front().Decls) {
2400  AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2401  D->getAccess());
2402  R.addDecl(D, AS);
2403  }
2404  R.resolveKind();
2405  return true;
2406 }
2407 
2408 /// Performs qualified name lookup or special type of lookup for
2409 /// "__super::" scope specifier.
2410 ///
2411 /// This routine is a convenience overload meant to be called from contexts
2412 /// that need to perform a qualified name lookup with an optional C++ scope
2413 /// specifier that might require special kind of lookup.
2414 ///
2415 /// \param R captures both the lookup criteria and any lookup results found.
2416 ///
2417 /// \param LookupCtx The context in which qualified name lookup will
2418 /// search.
2419 ///
2420 /// \param SS An optional C++ scope-specifier.
2421 ///
2422 /// \returns true if lookup succeeded, false if it failed.
2424  CXXScopeSpec &SS) {
2425  auto *NNS = SS.getScopeRep();
2426  if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2427  return LookupInSuper(R, NNS->getAsRecordDecl());
2428  else
2429 
2430  return LookupQualifiedName(R, LookupCtx);
2431 }
2432 
2433 /// Performs name lookup for a name that was parsed in the
2434 /// source code, and may contain a C++ scope specifier.
2435 ///
2436 /// This routine is a convenience routine meant to be called from
2437 /// contexts that receive a name and an optional C++ scope specifier
2438 /// (e.g., "N::M::x"). It will then perform either qualified or
2439 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2440 /// respectively) on the given name and return those results. It will
2441 /// perform a special type of lookup for "__super::" scope specifier.
2442 ///
2443 /// @param S The scope from which unqualified name lookup will
2444 /// begin.
2445 ///
2446 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2447 ///
2448 /// @param EnteringContext Indicates whether we are going to enter the
2449 /// context of the scope-specifier SS (if present).
2450 ///
2451 /// @returns True if any decls were found (but possibly ambiguous)
2453  bool AllowBuiltinCreation, bool EnteringContext) {
2454  if (SS && SS->isInvalid()) {
2455  // When the scope specifier is invalid, don't even look for
2456  // anything.
2457  return false;
2458  }
2459 
2460  if (SS && SS->isSet()) {
2461  NestedNameSpecifier *NNS = SS->getScopeRep();
2462  if (NNS->getKind() == NestedNameSpecifier::Super)
2463  return LookupInSuper(R, NNS->getAsRecordDecl());
2464 
2465  if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2466  // We have resolved the scope specifier to a particular declaration
2467  // contex, and will perform name lookup in that context.
2468  if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2469  return false;
2470 
2471  R.setContextRange(SS->getRange());
2472  return LookupQualifiedName(R, DC);
2473  }
2474 
2475  // We could not resolve the scope specified to a specific declaration
2476  // context, which means that SS refers to an unknown specialization.
2477  // Name lookup can't find anything in this case.
2479  R.setContextRange(SS->getRange());
2480  return false;
2481  }
2482 
2483  // Perform unqualified name lookup starting in the given scope.
2484  return LookupName(R, S, AllowBuiltinCreation);
2485 }
2486 
2487 /// Perform qualified name lookup into all base classes of the given
2488 /// class.
2489 ///
2490 /// \param R captures both the lookup criteria and any lookup results found.
2491 ///
2492 /// \param Class The context in which qualified name lookup will
2493 /// search. Name lookup will search in all base classes merging the results.
2494 ///
2495 /// @returns True if any decls were found (but possibly ambiguous)
2497  // The access-control rules we use here are essentially the rules for
2498  // doing a lookup in Class that just magically skipped the direct
2499  // members of Class itself. That is, the naming class is Class, and the
2500  // access includes the access of the base.
2501  for (const auto &BaseSpec : Class->bases()) {
2502  CXXRecordDecl *RD = cast<CXXRecordDecl>(
2503  BaseSpec.getType()->castAs<RecordType>()->getDecl());
2504  LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2505  Result.setBaseObjectType(Context.getRecordType(Class));
2506  LookupQualifiedName(Result, RD);
2507 
2508  // Copy the lookup results into the target, merging the base's access into
2509  // the path access.
2510  for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2511  R.addDecl(I.getDecl(),
2512  CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2513  I.getAccess()));
2514  }
2515 
2516  Result.suppressDiagnostics();
2517  }
2518 
2519  R.resolveKind();
2520  R.setNamingClass(Class);
2521 
2522  return !R.empty();
2523 }
2524 
2525 /// Produce a diagnostic describing the ambiguity that resulted
2526 /// from name lookup.
2527 ///
2528 /// \param Result The result of the ambiguous lookup to be diagnosed.
2530  assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2531 
2532  DeclarationName Name = Result.getLookupName();
2533  SourceLocation NameLoc = Result.getNameLoc();
2534  SourceRange LookupRange = Result.getContextRange();
2535 
2536  switch (Result.getAmbiguityKind()) {
2538  CXXBasePaths *Paths = Result.getBasePaths();
2539  QualType SubobjectType = Paths->front().back().Base->getType();
2540  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2541  << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2542  << LookupRange;
2543 
2544  DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2545  while (isa<CXXMethodDecl>(*Found) &&
2546  cast<CXXMethodDecl>(*Found)->isStatic())
2547  ++Found;
2548 
2549  Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2550  break;
2551  }
2552 
2554  Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2555  << Name << LookupRange;
2556 
2557  CXXBasePaths *Paths = Result.getBasePaths();
2558  std::set<Decl *> DeclsPrinted;
2559  for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2560  PathEnd = Paths->end();
2561  Path != PathEnd; ++Path) {
2562  Decl *D = Path->Decls.front();
2563  if (DeclsPrinted.insert(D).second)
2564  Diag(D->getLocation(), diag::note_ambiguous_member_found);
2565  }
2566  break;
2567  }
2568 
2570  Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2571 
2572  llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2573 
2574  for (auto *D : Result)
2575  if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2576  TagDecls.insert(TD);
2577  Diag(TD->getLocation(), diag::note_hidden_tag);
2578  }
2579 
2580  for (auto *D : Result)
2581  if (!isa<TagDecl>(D))
2582  Diag(D->getLocation(), diag::note_hiding_object);
2583 
2584  // For recovery purposes, go ahead and implement the hiding.
2585  LookupResult::Filter F = Result.makeFilter();
2586  while (F.hasNext()) {
2587  if (TagDecls.count(F.next()))
2588  F.erase();
2589  }
2590  F.done();
2591  break;
2592  }
2593 
2595  Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2596 
2597  for (auto *D : Result)
2598  Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2599  break;
2600  }
2601  }
2602 }
2603 
2604 namespace {
2605  struct AssociatedLookup {
2606  AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2607  Sema::AssociatedNamespaceSet &Namespaces,
2608  Sema::AssociatedClassSet &Classes)
2609  : S(S), Namespaces(Namespaces), Classes(Classes),
2610  InstantiationLoc(InstantiationLoc) {
2611  }
2612 
2613  bool addClassTransitive(CXXRecordDecl *RD) {
2614  Classes.insert(RD);
2615  return ClassesTransitive.insert(RD);
2616  }
2617 
2618  Sema &S;
2619  Sema::AssociatedNamespaceSet &Namespaces;
2620  Sema::AssociatedClassSet &Classes;
2621  SourceLocation InstantiationLoc;
2622 
2623  private:
2624  Sema::AssociatedClassSet ClassesTransitive;
2625  };
2626 } // end anonymous namespace
2627 
2628 static void
2629 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2630 
2631 // Given the declaration context \param Ctx of a class, class template or
2632 // enumeration, add the associated namespaces to \param Namespaces as described
2633 // in [basic.lookup.argdep]p2.
2635  DeclContext *Ctx) {
2636  // The exact wording has been changed in C++14 as a result of
2637  // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
2638  // to all language versions since it is possible to return a local type
2639  // from a lambda in C++11.
2640  //
2641  // C++14 [basic.lookup.argdep]p2:
2642  // If T is a class type [...]. Its associated namespaces are the innermost
2643  // enclosing namespaces of its associated classes. [...]
2644  //
2645  // If T is an enumeration type, its associated namespace is the innermost
2646  // enclosing namespace of its declaration. [...]
2647 
2648  // We additionally skip inline namespaces. The innermost non-inline namespace
2649  // contains all names of all its nested inline namespaces anyway, so we can
2650  // replace the entire inline namespace tree with its root.
2651  while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
2652  Ctx = Ctx->getParent();
2653 
2654  Namespaces.insert(Ctx->getPrimaryContext());
2655 }
2656 
2657 // Add the associated classes and namespaces for argument-dependent
2658 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
2659 static void
2660 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2661  const TemplateArgument &Arg) {
2662  // C++ [basic.lookup.argdep]p2, last bullet:
2663  // -- [...] ;
2664  switch (Arg.getKind()) {
2666  break;
2667 
2669  // [...] the namespaces and classes associated with the types of the
2670  // template arguments provided for template type parameters (excluding
2671  // template template parameters)
2673  break;
2674 
2677  // [...] the namespaces in which any template template arguments are
2678  // defined; and the classes in which any member templates used as
2679  // template template arguments are defined.
2681  if (ClassTemplateDecl *ClassTemplate
2682  = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2683  DeclContext *Ctx = ClassTemplate->getDeclContext();
2684  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2685  Result.Classes.insert(EnclosingClass);
2686  // Add the associated namespace for this class.
2687  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2688  }
2689  break;
2690  }
2691 
2696  // [Note: non-type template arguments do not contribute to the set of
2697  // associated namespaces. ]
2698  break;
2699 
2701  for (const auto &P : Arg.pack_elements())
2703  break;
2704  }
2705 }
2706 
2707 // Add the associated classes and namespaces for argument-dependent lookup
2708 // with an argument of class type (C++ [basic.lookup.argdep]p2).
2709 static void
2710 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2711  CXXRecordDecl *Class) {
2712 
2713  // Just silently ignore anything whose name is __va_list_tag.
2714  if (Class->getDeclName() == Result.S.VAListTagName)
2715  return;
2716 
2717  // C++ [basic.lookup.argdep]p2:
2718  // [...]
2719  // -- If T is a class type (including unions), its associated
2720  // classes are: the class itself; the class of which it is a
2721  // member, if any; and its direct and indirect base classes.
2722  // Its associated namespaces are the innermost enclosing
2723  // namespaces of its associated classes.
2724 
2725  // Add the class of which it is a member, if any.
2726  DeclContext *Ctx = Class->getDeclContext();
2727  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2728  Result.Classes.insert(EnclosingClass);
2729 
2730  // Add the associated namespace for this class.
2731  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2732 
2733  // -- If T is a template-id, its associated namespaces and classes are
2734  // the namespace in which the template is defined; for member
2735  // templates, the member template's class; the namespaces and classes
2736  // associated with the types of the template arguments provided for
2737  // template type parameters (excluding template template parameters); the
2738  // namespaces in which any template template arguments are defined; and
2739  // the classes in which any member templates used as template template
2740  // arguments are defined. [Note: non-type template arguments do not
2741  // contribute to the set of associated namespaces. ]
2743  = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2744  DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2745  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2746  Result.Classes.insert(EnclosingClass);
2747  // Add the associated namespace for this class.
2748  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2749 
2750  const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2751  for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2752  addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2753  }
2754 
2755  // Add the class itself. If we've already transitively visited this class,
2756  // we don't need to visit base classes.
2757  if (!Result.addClassTransitive(Class))
2758  return;
2759 
2760  // Only recurse into base classes for complete types.
2761  if (!Result.S.isCompleteType(Result.InstantiationLoc,
2762  Result.S.Context.getRecordType(Class)))
2763  return;
2764 
2765  // Add direct and indirect base classes along with their associated
2766  // namespaces.
2768  Bases.push_back(Class);
2769  while (!Bases.empty()) {
2770  // Pop this class off the stack.
2771  Class = Bases.pop_back_val();
2772 
2773  // Visit the base classes.
2774  for (const auto &Base : Class->bases()) {
2775  const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2776  // In dependent contexts, we do ADL twice, and the first time around,
2777  // the base type might be a dependent TemplateSpecializationType, or a
2778  // TemplateTypeParmType. If that happens, simply ignore it.
2779  // FIXME: If we want to support export, we probably need to add the
2780  // namespace of the template in a TemplateSpecializationType, or even
2781  // the classes and namespaces of known non-dependent arguments.
2782  if (!BaseType)
2783  continue;
2784  CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2785  if (Result.addClassTransitive(BaseDecl)) {
2786  // Find the associated namespace for this base class.
2787  DeclContext *BaseCtx = BaseDecl->getDeclContext();
2788  CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2789 
2790  // Make sure we visit the bases of this base class.
2791  if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2792  Bases.push_back(BaseDecl);
2793  }
2794  }
2795  }
2796 }
2797 
2798 // Add the associated classes and namespaces for
2799 // argument-dependent lookup with an argument of type T
2800 // (C++ [basic.lookup.koenig]p2).
2801 static void
2802 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2803  // C++ [basic.lookup.koenig]p2:
2804  //
2805  // For each argument type T in the function call, there is a set
2806  // of zero or more associated namespaces and a set of zero or more
2807  // associated classes to be considered. The sets of namespaces and
2808  // classes is determined entirely by the types of the function
2809  // arguments (and the namespace of any template template
2810  // argument). Typedef names and using-declarations used to specify
2811  // the types do not contribute to this set. The sets of namespaces
2812  // and classes are determined in the following way:
2813 
2815  const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2816 
2817  while (true) {
2818  switch (T->getTypeClass()) {
2819 
2820 #define TYPE(Class, Base)
2821 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2822 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2823 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2824 #define ABSTRACT_TYPE(Class, Base)
2825 #include "clang/AST/TypeNodes.def"
2826  // T is canonical. We can also ignore dependent types because
2827  // we don't need to do ADL at the definition point, but if we
2828  // wanted to implement template export (or if we find some other
2829  // use for associated classes and namespaces...) this would be
2830  // wrong.
2831  break;
2832 
2833  // -- If T is a pointer to U or an array of U, its associated
2834  // namespaces and classes are those associated with U.
2835  case Type::Pointer:
2836  T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2837  continue;
2838  case Type::ConstantArray:
2839  case Type::IncompleteArray:
2840  case Type::VariableArray:
2841  T = cast<ArrayType>(T)->getElementType().getTypePtr();
2842  continue;
2843 
2844  // -- If T is a fundamental type, its associated sets of
2845  // namespaces and classes are both empty.
2846  case Type::Builtin:
2847  break;
2848 
2849  // -- If T is a class type (including unions), its associated
2850  // classes are: the class itself; the class of which it is
2851  // a member, if any; and its direct and indirect base classes.
2852  // Its associated namespaces are the innermost enclosing
2853  // namespaces of its associated classes.
2854  case Type::Record: {
2855  CXXRecordDecl *Class =
2856  cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2857  addAssociatedClassesAndNamespaces(Result, Class);
2858  break;
2859  }
2860 
2861  // -- If T is an enumeration type, its associated namespace
2862  // is the innermost enclosing namespace of its declaration.
2863  // If it is a class member, its associated class is the
2864  // member’s class; else it has no associated class.
2865  case Type::Enum: {
2866  EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2867 
2868  DeclContext *Ctx = Enum->getDeclContext();
2869  if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2870  Result.Classes.insert(EnclosingClass);
2871 
2872  // Add the associated namespace for this enumeration.
2873  CollectEnclosingNamespace(Result.Namespaces, Ctx);
2874 
2875  break;
2876  }
2877 
2878  // -- If T is a function type, its associated namespaces and
2879  // classes are those associated with the function parameter
2880  // types and those associated with the return type.
2881  case Type::FunctionProto: {
2882  const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2883  for (const auto &Arg : Proto->param_types())
2884  Queue.push_back(Arg.getTypePtr());
2885  // fallthrough
2886  LLVM_FALLTHROUGH;
2887  }
2888  case Type::FunctionNoProto: {
2889  const FunctionType *FnType = cast<FunctionType>(T);
2890  T = FnType->getReturnType().getTypePtr();
2891  continue;
2892  }
2893 
2894  // -- If T is a pointer to a member function of a class X, its
2895  // associated namespaces and classes are those associated
2896  // with the function parameter types and return type,
2897  // together with those associated with X.
2898  //
2899  // -- If T is a pointer to a data member of class X, its
2900  // associated namespaces and classes are those associated
2901  // with the member type together with those associated with
2902  // X.
2903  case Type::MemberPointer: {
2904  const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2905 
2906  // Queue up the class type into which this points.
2907  Queue.push_back(MemberPtr->getClass());
2908 
2909  // And directly continue with the pointee type.
2910  T = MemberPtr->getPointeeType().getTypePtr();
2911  continue;
2912  }
2913 
2914  // As an extension, treat this like a normal pointer.
2915  case Type::BlockPointer:
2916  T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2917  continue;
2918 
2919  // References aren't covered by the standard, but that's such an
2920  // obvious defect that we cover them anyway.
2921  case Type::LValueReference:
2922  case Type::RValueReference:
2923  T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2924  continue;
2925 
2926  // These are fundamental types.
2927  case Type::Vector:
2928  case Type::ExtVector:
2929  case Type::Complex:
2930  break;
2931 
2932  // Non-deduced auto types only get here for error cases.
2933  case Type::Auto:
2934  case Type::DeducedTemplateSpecialization:
2935  break;
2936 
2937  // If T is an Objective-C object or interface type, or a pointer to an
2938  // object or interface type, the associated namespace is the global
2939  // namespace.
2940  case Type::ObjCObject:
2941  case Type::ObjCInterface:
2942  case Type::ObjCObjectPointer:
2943  Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2944  break;
2945 
2946  // Atomic types are just wrappers; use the associations of the
2947  // contained type.
2948  case Type::Atomic:
2949  T = cast<AtomicType>(T)->getValueType().getTypePtr();
2950  continue;
2951  case Type::Pipe:
2952  T = cast<PipeType>(T)->getElementType().getTypePtr();
2953  continue;
2954  }
2955 
2956  if (Queue.empty())
2957  break;
2958  T = Queue.pop_back_val();
2959  }
2960 }
2961 
2962 /// Find the associated classes and namespaces for
2963 /// argument-dependent lookup for a call with the given set of
2964 /// arguments.
2965 ///
2966 /// This routine computes the sets of associated classes and associated
2967 /// namespaces searched by argument-dependent lookup
2968 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2970  SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2971  AssociatedNamespaceSet &AssociatedNamespaces,
2972  AssociatedClassSet &AssociatedClasses) {
2973  AssociatedNamespaces.clear();
2974  AssociatedClasses.clear();
2975 
2976  AssociatedLookup Result(*this, InstantiationLoc,
2977  AssociatedNamespaces, AssociatedClasses);
2978 
2979  // C++ [basic.lookup.koenig]p2:
2980  // For each argument type T in the function call, there is a set
2981  // of zero or more associated namespaces and a set of zero or more
2982  // associated classes to be considered. The sets of namespaces and
2983  // classes is determined entirely by the types of the function
2984  // arguments (and the namespace of any template template
2985  // argument).
2986  for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2987  Expr *Arg = Args[ArgIdx];
2988 
2989  if (Arg->getType() != Context.OverloadTy) {
2991  continue;
2992  }
2993 
2994  // [...] In addition, if the argument is the name or address of a
2995  // set of overloaded functions and/or function templates, its
2996  // associated classes and namespaces are the union of those
2997  // associated with each of the members of the set: the namespace
2998  // in which the function or function template is defined and the
2999  // classes and namespaces associated with its (non-dependent)
3000  // parameter types and return type.
3002 
3003  for (const NamedDecl *D : OE->decls()) {
3004  // Look through any using declarations to find the underlying function.
3005  const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
3006 
3007  // Add the classes and namespaces associated with the parameter
3008  // types and return type of this function.
3009  addAssociatedClassesAndNamespaces(Result, FDecl->getType());
3010  }
3011  }
3012 }
3013 
3015  SourceLocation Loc,
3016  LookupNameKind NameKind,
3017  RedeclarationKind Redecl) {
3018  LookupResult R(*this, Name, Loc, NameKind, Redecl);
3019  LookupName(R, S);
3020  return R.getAsSingle<NamedDecl>();
3021 }
3022 
3023 /// Find the protocol with the given name, if any.
3025  SourceLocation IdLoc,
3026  RedeclarationKind Redecl) {
3027  Decl *D = LookupSingleName(TUScope, II, IdLoc,
3028  LookupObjCProtocolName, Redecl);
3029  return cast_or_null<ObjCProtocolDecl>(D);
3030 }
3031 
3033  QualType T1, QualType T2,
3034  UnresolvedSetImpl &Functions) {
3035  // C++ [over.match.oper]p3:
3036  // -- The set of non-member candidates is the result of the
3037  // unqualified lookup of operator@ in the context of the
3038  // expression according to the usual rules for name lookup in
3039  // unqualified function calls (3.4.2) except that all member
3040  // functions are ignored.
3042  LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
3043  LookupName(Operators, S);
3044 
3045  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
3046  Functions.append(Operators.begin(), Operators.end());
3047 }
3048 
3051  bool ConstArg,
3052  bool VolatileArg,
3053  bool RValueThis,
3054  bool ConstThis,
3055  bool VolatileThis) {
3056  assert(CanDeclareSpecialMemberFunction(RD) &&
3057  "doing special member lookup into record that isn't fully complete");
3058  RD = RD->getDefinition();
3059  if (RValueThis || ConstThis || VolatileThis)
3060  assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
3061  "constructors and destructors always have unqualified lvalue this");
3062  if (ConstArg || VolatileArg)
3063  assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
3064  "parameter-less special members can't have qualified arguments");
3065 
3066  // FIXME: Get the caller to pass in a location for the lookup.
3067  SourceLocation LookupLoc = RD->getLocation();
3068 
3069  llvm::FoldingSetNodeID ID;
3070  ID.AddPointer(RD);
3071  ID.AddInteger(SM);
3072  ID.AddInteger(ConstArg);
3073  ID.AddInteger(VolatileArg);
3074  ID.AddInteger(RValueThis);
3075  ID.AddInteger(ConstThis);
3076  ID.AddInteger(VolatileThis);
3077 
3078  void *InsertPoint;
3080  SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
3081 
3082  // This was already cached
3083  if (Result)
3084  return *Result;
3085 
3086  Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3087  Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3088  SpecialMemberCache.InsertNode(Result, InsertPoint);
3089 
3090  if (SM == CXXDestructor) {
3091  if (RD->needsImplicitDestructor()) {
3093  DeclareImplicitDestructor(RD);
3094  });
3095  }
3096  CXXDestructorDecl *DD = RD->getDestructor();
3097  assert(DD && "record without a destructor");
3098  Result->setMethod(DD);
3099  Result->setKind(DD->isDeleted() ?
3100  SpecialMemberOverloadResult::NoMemberOrDeleted :
3101  SpecialMemberOverloadResult::Success);
3102  return *Result;
3103  }
3104 
3105  // Prepare for overload resolution. Here we construct a synthetic argument
3106  // if necessary and make sure that implicit functions are declared.
3107  CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
3108  DeclarationName Name;
3109  Expr *Arg = nullptr;
3110  unsigned NumArgs;
3111 
3112  QualType ArgType = CanTy;
3113  ExprValueKind VK = VK_LValue;
3114 
3115  if (SM == CXXDefaultConstructor) {
3116  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3117  NumArgs = 0;
3118  if (RD->needsImplicitDefaultConstructor()) {
3120  DeclareImplicitDefaultConstructor(RD);
3121  });
3122  }
3123  } else {
3124  if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
3125  Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
3126  if (RD->needsImplicitCopyConstructor()) {
3128  DeclareImplicitCopyConstructor(RD);
3129  });
3130  }
3131  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) {
3133  DeclareImplicitMoveConstructor(RD);
3134  });
3135  }
3136  } else {
3137  Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
3138  if (RD->needsImplicitCopyAssignment()) {
3140  DeclareImplicitCopyAssignment(RD);
3141  });
3142  }
3143  if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) {
3145  DeclareImplicitMoveAssignment(RD);
3146  });
3147  }
3148  }
3149 
3150  if (ConstArg)
3151  ArgType.addConst();
3152  if (VolatileArg)
3153  ArgType.addVolatile();
3154 
3155  // This isn't /really/ specified by the standard, but it's implied
3156  // we should be working from an RValue in the case of move to ensure
3157  // that we prefer to bind to rvalue references, and an LValue in the
3158  // case of copy to ensure we don't bind to rvalue references.
3159  // Possibly an XValue is actually correct in the case of move, but
3160  // there is no semantic difference for class types in this restricted
3161  // case.
3162  if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
3163  VK = VK_LValue;
3164  else
3165  VK = VK_RValue;
3166  }
3167 
3168  OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
3169 
3170  if (SM != CXXDefaultConstructor) {
3171  NumArgs = 1;
3172  Arg = &FakeArg;
3173  }
3174 
3175  // Create the object argument
3176  QualType ThisTy = CanTy;
3177  if (ConstThis)
3178  ThisTy.addConst();
3179  if (VolatileThis)
3180  ThisTy.addVolatile();
3181  Expr::Classification Classification =
3182  OpaqueValueExpr(LookupLoc, ThisTy,
3183  RValueThis ? VK_RValue : VK_LValue).Classify(Context);
3184 
3185  // Now we perform lookup on the name we computed earlier and do overload
3186  // resolution. Lookup is only performed directly into the class since there
3187  // will always be a (possibly implicit) declaration to shadow any others.
3189  DeclContext::lookup_result R = RD->lookup(Name);
3190 
3191  if (R.empty()) {
3192  // We might have no default constructor because we have a lambda's closure
3193  // type, rather than because there's some other declared constructor.
3194  // Every class has a copy/move constructor, copy/move assignment, and
3195  // destructor.
3196  assert(SM == CXXDefaultConstructor &&
3197  "lookup for a constructor or assignment operator was empty");
3198  Result->setMethod(nullptr);
3199  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3200  return *Result;
3201  }
3202 
3203  // Copy the candidates as our processing of them may load new declarations
3204  // from an external source and invalidate lookup_result.
3205  SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
3206 
3207  for (NamedDecl *CandDecl : Candidates) {
3208  if (CandDecl->isInvalidDecl())
3209  continue;
3210 
3211  DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
3212  auto CtorInfo = getConstructorInfo(Cand);
3213  if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
3214  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3215  AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
3216  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3217  else if (CtorInfo)
3218  AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
3219  llvm::makeArrayRef(&Arg, NumArgs), OCS,
3220  /*SuppressUserConversions*/ true);
3221  else
3222  AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
3223  /*SuppressUserConversions*/ true);
3224  } else if (FunctionTemplateDecl *Tmpl =
3225  dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
3226  if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3227  AddMethodTemplateCandidate(
3228  Tmpl, Cand, RD, nullptr, ThisTy, Classification,
3229  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3230  else if (CtorInfo)
3231  AddTemplateOverloadCandidate(
3232  CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
3233  llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3234  else
3235  AddTemplateOverloadCandidate(
3236  Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3237  } else {
3238  assert(isa<UsingDecl>(Cand.getDecl()) &&
3239  "illegal Kind of operator = Decl");
3240  }
3241  }
3242 
3244  switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
3245  case OR_Success:
3246  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3247  Result->setKind(SpecialMemberOverloadResult::Success);
3248  break;
3249 
3250  case OR_Deleted:
3251  Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3252  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3253  break;
3254 
3255  case OR_Ambiguous:
3256  Result->setMethod(nullptr);
3257  Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3258  break;
3259 
3260  case OR_No_Viable_Function:
3261  Result->setMethod(nullptr);
3262  Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3263  break;
3264  }
3265 
3266  return *Result;
3267 }
3268 
3269 /// Look up the default constructor for the given class.
3272  LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3273  false, false);
3274 
3275  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3276 }
3277 
3278 /// Look up the copying constructor for the given class.
3280  unsigned Quals) {
3281  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3282  "non-const, non-volatile qualifiers for copy ctor arg");
3284  LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
3285  Quals & Qualifiers::Volatile, false, false, false);
3286 
3287  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3288 }
3289 
3290 /// Look up the moving constructor for the given class.
3292  unsigned Quals) {
3294  LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
3295  Quals & Qualifiers::Volatile, false, false, false);
3296 
3297  return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3298 }
3299 
3300 /// Look up the constructors for the given class.
3302  // If the implicit constructors have not yet been declared, do so now.
3303  if (CanDeclareSpecialMemberFunction(Class)) {
3305  if (Class->needsImplicitDefaultConstructor())
3306  DeclareImplicitDefaultConstructor(Class);
3307  if (Class->needsImplicitCopyConstructor())
3308  DeclareImplicitCopyConstructor(Class);
3309  if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3310  DeclareImplicitMoveConstructor(Class);
3311  });
3312  }
3313 
3314  CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3316  return Class->lookup(Name);
3317 }
3318 
3319 /// Look up the copying assignment operator for the given class.
3321  unsigned Quals, bool RValueThis,
3322  unsigned ThisQuals) {
3323  assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3324  "non-const, non-volatile qualifiers for copy assignment arg");
3325  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3326  "non-const, non-volatile qualifiers for copy assignment this");
3328  LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3329  Quals & Qualifiers::Volatile, RValueThis,
3330  ThisQuals & Qualifiers::Const,
3331  ThisQuals & Qualifiers::Volatile);
3332 
3333  return Result.getMethod();
3334 }
3335 
3336 /// Look up the moving assignment operator for the given class.
3338  unsigned Quals,
3339  bool RValueThis,
3340  unsigned ThisQuals) {
3341  assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3342  "non-const, non-volatile qualifiers for copy assignment this");
3344  LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3345  Quals & Qualifiers::Volatile, RValueThis,
3346  ThisQuals & Qualifiers::Const,
3347  ThisQuals & Qualifiers::Volatile);
3348 
3349  return Result.getMethod();
3350 }
3351 
3352 /// Look for the destructor of the given class.
3353 ///
3354 /// During semantic analysis, this routine should be used in lieu of
3355 /// CXXRecordDecl::getDestructor().
3356 ///
3357 /// \returns The destructor for this class.
3359  return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3360  false, false, false,
3361  false, false).getMethod());
3362 }
3363 
3364 /// LookupLiteralOperator - Determine which literal operator should be used for
3365 /// a user-defined literal, per C++11 [lex.ext].
3366 ///
3367 /// Normal overload resolution is not used to select which literal operator to
3368 /// call for a user-defined literal. Look up the provided literal operator name,
3369 /// and filter the results to the appropriate set for the given argument types.
3372  ArrayRef<QualType> ArgTys,
3373  bool AllowRaw, bool AllowTemplate,
3374  bool AllowStringTemplate, bool DiagnoseMissing) {
3375  LookupName(R, S);
3376  assert(R.getResultKind() != LookupResult::Ambiguous &&
3377  "literal operator lookup can't be ambiguous");
3378 
3379  // Filter the lookup results appropriately.
3381 
3382  bool FoundRaw = false;
3383  bool FoundTemplate = false;
3384  bool FoundStringTemplate = false;
3385  bool FoundExactMatch = false;
3386 
3387  while (F.hasNext()) {
3388  Decl *D = F.next();
3389  if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3390  D = USD->getTargetDecl();
3391 
3392  // If the declaration we found is invalid, skip it.
3393  if (D->isInvalidDecl()) {
3394  F.erase();
3395  continue;
3396  }
3397 
3398  bool IsRaw = false;
3399  bool IsTemplate = false;
3400  bool IsStringTemplate = false;
3401  bool IsExactMatch = false;
3402 
3403  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3404  if (FD->getNumParams() == 1 &&
3405  FD->getParamDecl(0)->getType()->getAs<PointerType>())
3406  IsRaw = true;
3407  else if (FD->getNumParams() == ArgTys.size()) {
3408  IsExactMatch = true;
3409  for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3410  QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3411  if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3412  IsExactMatch = false;
3413  break;
3414  }
3415  }
3416  }
3417  }
3418  if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3419  TemplateParameterList *Params = FD->getTemplateParameters();
3420  if (Params->size() == 1)
3421  IsTemplate = true;
3422  else
3423  IsStringTemplate = true;
3424  }
3425 
3426  if (IsExactMatch) {
3427  FoundExactMatch = true;
3428  AllowRaw = false;
3429  AllowTemplate = false;
3430  AllowStringTemplate = false;
3431  if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3432  // Go through again and remove the raw and template decls we've
3433  // already found.
3434  F.restart();
3435  FoundRaw = FoundTemplate = FoundStringTemplate = false;
3436  }
3437  } else if (AllowRaw && IsRaw) {
3438  FoundRaw = true;
3439  } else if (AllowTemplate && IsTemplate) {
3440  FoundTemplate = true;
3441  } else if (AllowStringTemplate && IsStringTemplate) {
3442  FoundStringTemplate = true;
3443  } else {
3444  F.erase();
3445  }
3446  }
3447 
3448  F.done();
3449 
3450  // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3451  // parameter type, that is used in preference to a raw literal operator
3452  // or literal operator template.
3453  if (FoundExactMatch)
3454  return LOLR_Cooked;
3455 
3456  // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3457  // operator template, but not both.
3458  if (FoundRaw && FoundTemplate) {
3459  Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3460  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3461  NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3462  return LOLR_Error;
3463  }
3464 
3465  if (FoundRaw)
3466  return LOLR_Raw;
3467 
3468  if (FoundTemplate)
3469  return LOLR_Template;
3470 
3471  if (FoundStringTemplate)
3472  return LOLR_StringTemplate;
3473 
3474  // Didn't find anything we could use.
3475  if (DiagnoseMissing) {
3476  Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3477  << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3478  << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3479  << (AllowTemplate || AllowStringTemplate);
3480  return LOLR_Error;
3481  }
3482 
3483  return LOLR_ErrorNoDiagnostic;
3484 }
3485 
3487  NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3488 
3489  // If we haven't yet seen a decl for this key, or the last decl
3490  // was exactly this one, we're done.
3491  if (Old == nullptr || Old == New) {
3492  Old = New;
3493  return;
3494  }
3495 
3496  // Otherwise, decide which is a more recent redeclaration.
3497  FunctionDecl *OldFD = Old->getAsFunction();
3498  FunctionDecl *NewFD = New->getAsFunction();
3499 
3500  FunctionDecl *Cursor = NewFD;
3501  while (true) {
3502  Cursor = Cursor->getPreviousDecl();
3503 
3504  // If we got to the end without finding OldFD, OldFD is the newer
3505  // declaration; leave things as they are.
3506  if (!Cursor) return;
3507 
3508  // If we do find OldFD, then NewFD is newer.
3509  if (Cursor == OldFD) break;
3510 
3511  // Otherwise, keep looking.
3512  }
3513 
3514  Old = New;
3515 }
3516 
3518  ArrayRef<Expr *> Args, ADLResult &Result) {
3519  // Find all of the associated namespaces and classes based on the
3520  // arguments we have.
3521  AssociatedNamespaceSet AssociatedNamespaces;
3522  AssociatedClassSet AssociatedClasses;
3523  FindAssociatedClassesAndNamespaces(Loc, Args,
3524  AssociatedNamespaces,
3525  AssociatedClasses);
3526 
3527  // C++ [basic.lookup.argdep]p3:
3528  // Let X be the lookup set produced by unqualified lookup (3.4.1)
3529  // and let Y be the lookup set produced by argument dependent
3530  // lookup (defined as follows). If X contains [...] then Y is
3531  // empty. Otherwise Y is the set of declarations found in the
3532  // namespaces associated with the argument types as described
3533  // below. The set of declarations found by the lookup of the name
3534  // is the union of X and Y.
3535  //
3536  // Here, we compute Y and add its members to the overloaded
3537  // candidate set.
3538  for (auto *NS : AssociatedNamespaces) {
3539  // When considering an associated namespace, the lookup is the
3540  // same as the lookup performed when the associated namespace is
3541  // used as a qualifier (3.4.3.2) except that:
3542  //
3543  // -- Any using-directives in the associated namespace are
3544  // ignored.
3545  //
3546  // -- Any namespace-scope friend functions declared in
3547  // associated classes are visible within their respective
3548  // namespaces even if they are not visible during an ordinary
3549  // lookup (11.4).
3550  DeclContext::lookup_result R = NS->lookup(Name);
3551  for (auto *D : R) {
3552  auto *Underlying = D;
3553  if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3554  Underlying = USD->getTargetDecl();
3555 
3556  if (!isa<FunctionDecl>(Underlying) &&
3557  !isa<FunctionTemplateDecl>(Underlying))
3558  continue;
3559 
3560  // The declaration is visible to argument-dependent lookup if either
3561  // it's ordinarily visible or declared as a friend in an associated
3562  // class.
3563  bool Visible = false;
3564  for (D = D->getMostRecentDecl(); D;
3565  D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
3567  if (isVisible(D)) {
3568  Visible = true;
3569  break;
3570  }
3571  } else if (D->getFriendObjectKind()) {
3572  auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
3573  if (AssociatedClasses.count(RD) && isVisible(D)) {
3574  Visible = true;
3575  break;
3576  }
3577  }
3578  }
3579 
3580  // FIXME: Preserve D as the FoundDecl.
3581  if (Visible)
3582  Result.insert(Underlying);
3583  }
3584  }
3585 }
3586 
3587 //----------------------------------------------------------------------------
3588 // Search for all visible declarations.
3589 //----------------------------------------------------------------------------
3591 
3592 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3593 
3594 namespace {
3595 
3596 class ShadowContextRAII;
3597 
3598 class VisibleDeclsRecord {
3599 public:
3600  /// An entry in the shadow map, which is optimized to store a
3601  /// single declaration (the common case) but can also store a list
3602  /// of declarations.
3603  typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3604 
3605 private:
3606  /// A mapping from declaration names to the declarations that have
3607  /// this name within a particular scope.
3608  typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3609 
3610  /// A list of shadow maps, which is used to model name hiding.
3611  std::list<ShadowMap> ShadowMaps;
3612 
3613  /// The declaration contexts we have already visited.
3614  llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3615 
3616  friend class ShadowContextRAII;
3617 
3618 public:
3619  /// Determine whether we have already visited this context
3620  /// (and, if not, note that we are going to visit that context now).
3621  bool visitedContext(DeclContext *Ctx) {
3622  return !VisitedContexts.insert(Ctx).second;
3623  }
3624 
3625  bool alreadyVisitedContext(DeclContext *Ctx) {
3626  return VisitedContexts.count(Ctx);
3627  }
3628 
3629  /// Determine whether the given declaration is hidden in the
3630  /// current scope.
3631  ///
3632  /// \returns the declaration that hides the given declaration, or
3633  /// NULL if no such declaration exists.
3634  NamedDecl *checkHidden(NamedDecl *ND);
3635 
3636  /// Add a declaration to the current shadow map.
3637  void add(NamedDecl *ND) {
3638  ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3639  }
3640 };
3641 
3642 /// RAII object that records when we've entered a shadow context.
3643 class ShadowContextRAII {
3644  VisibleDeclsRecord &Visible;
3645 
3646  typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3647 
3648 public:
3649  ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3650  Visible.ShadowMaps.emplace_back();
3651  }
3652 
3653  ~ShadowContextRAII() {
3654  Visible.ShadowMaps.pop_back();
3655  }
3656 };
3657 
3658 } // end anonymous namespace
3659 
3660 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3661  unsigned IDNS = ND->getIdentifierNamespace();
3662  std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3663  for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3664  SM != SMEnd; ++SM) {
3665  ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3666  if (Pos == SM->end())
3667  continue;
3668 
3669  for (auto *D : Pos->second) {
3670  // A tag declaration does not hide a non-tag declaration.
3671  if (D->hasTagIdentifierNamespace() &&
3674  continue;
3675 
3676  // Protocols are in distinct namespaces from everything else.
3678  || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3679  D->getIdentifierNamespace() != IDNS)
3680  continue;
3681 
3682  // Functions and function templates in the same scope overload
3683  // rather than hide. FIXME: Look for hiding based on function
3684  // signatures!
3687  SM == ShadowMaps.rbegin())
3688  continue;
3689 
3690  // A shadow declaration that's created by a resolved using declaration
3691  // is not hidden by the same using declaration.
3692  if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3693  cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3694  continue;
3695 
3696  // We've found a declaration that hides this one.
3697  return D;
3698  }
3699  }
3700 
3701  return nullptr;
3702 }
3703 
3705 public:
3706  LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
3707  bool LoadExternal)
3708  : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
3709  LoadExternal(LoadExternal) {}
3710 
3712  bool IncludeGlobalScope) {
3713  // Determine the set of using directives available during
3714  // unqualified name lookup.
3715  Scope *Initial = S;
3716  UnqualUsingDirectiveSet UDirs(SemaRef);
3717  if (SemaRef.getLangOpts().CPlusPlus) {
3718  // Find the first namespace or translation-unit scope.
3719  while (S && !isNamespaceOrTranslationUnitScope(S))
3720  S = S->getParent();
3721 
3722  UDirs.visitScopeChain(Initial, S);
3723  }
3724  UDirs.done();
3725 
3726  // Look for visible declarations.
3727  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3728  Result.setAllowHidden(Consumer.includeHiddenDecls());
3729  if (!IncludeGlobalScope)
3730  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3731  ShadowContextRAII Shadow(Visited);
3732  lookupInScope(Initial, Result, UDirs);
3733  }
3734 
3735  void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
3736  Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
3737  LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
3738  Result.setAllowHidden(Consumer.includeHiddenDecls());
3739  if (!IncludeGlobalScope)
3740  Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
3741 
3742  ShadowContextRAII Shadow(Visited);
3743  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
3744  /*InBaseClass=*/false);
3745  }
3746 
3747 private:
3748  void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
3749  bool QualifiedNameLookup, bool InBaseClass) {
3750  if (!Ctx)
3751  return;
3752 
3753  // Make sure we don't visit the same context twice.
3754  if (Visited.visitedContext(Ctx->getPrimaryContext()))
3755  return;
3756 
3757  Consumer.EnteredContext(Ctx);
3758 
3759  // Outside C++, lookup results for the TU live on identifiers.
3760  if (isa<TranslationUnitDecl>(Ctx) &&
3761  !Result.getSema().getLangOpts().CPlusPlus) {
3762  auto &S = Result.getSema();
3763  auto &Idents = S.Context.Idents;
3764 
3765  // Ensure all external identifiers are in the identifier table.
3766  if (LoadExternal)
3767  if (IdentifierInfoLookup *External =
3768  Idents.getExternalIdentifierLookup()) {
3769  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3770  for (StringRef Name = Iter->Next(); !Name.empty();
3771  Name = Iter->Next())
3772  Idents.get(Name);
3773  }
3774 
3775  // Walk all lookup results in the TU for each identifier.
3776  for (const auto &Ident : Idents) {
3777  for (auto I = S.IdResolver.begin(Ident.getValue()),
3778  E = S.IdResolver.end();
3779  I != E; ++I) {
3780  if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3781  if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3782  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3783  Visited.add(ND);
3784  }
3785  }
3786  }
3787  }
3788 
3789  return;
3790  }
3791 
3792  if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3794 
3795  // We sometimes skip loading namespace-level results (they tend to be huge).
3796  bool Load = LoadExternal ||
3797  !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
3798  // Enumerate all of the results in this context.
3799  for (DeclContextLookupResult R :
3800  Load ? Ctx->lookups()
3801  : Ctx->noload_lookups(/*PreserveInternalState=*/false)) {
3802  for (auto *D : R) {
3803  if (auto *ND = Result.getAcceptableDecl(D)) {
3804  Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3805  Visited.add(ND);
3806  }
3807  }
3808  }
3809 
3810  // Traverse using directives for qualified name lookup.
3811  if (QualifiedNameLookup) {
3812  ShadowContextRAII Shadow(Visited);
3813  for (auto I : Ctx->using_directives()) {
3814  if (!Result.getSema().isVisible(I))
3815  continue;
3816  lookupInDeclContext(I->getNominatedNamespace(), Result,
3817  QualifiedNameLookup, InBaseClass);
3818  }
3819  }
3820 
3821  // Traverse the contexts of inherited C++ classes.
3822  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3823  if (!Record->hasDefinition())
3824  return;
3825 
3826  for (const auto &B : Record->bases()) {
3827  QualType BaseType = B.getType();
3828 
3829  RecordDecl *RD;
3830  if (BaseType->isDependentType()) {
3831  if (!IncludeDependentBases) {
3832  // Don't look into dependent bases, because name lookup can't look
3833  // there anyway.
3834  continue;
3835  }
3836  const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3837  if (!TST)
3838  continue;
3839  TemplateName TN = TST->getTemplateName();
3840  const auto *TD =
3841  dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3842  if (!TD)
3843  continue;
3844  RD = TD->getTemplatedDecl();
3845  } else {
3846  const auto *Record = BaseType->getAs<RecordType>();
3847  if (!Record)
3848  continue;
3849  RD = Record->getDecl();
3850  }
3851 
3852  // FIXME: It would be nice to be able to determine whether referencing
3853  // a particular member would be ambiguous. For example, given
3854  //
3855  // struct A { int member; };
3856  // struct B { int member; };
3857  // struct C : A, B { };
3858  //
3859  // void f(C *c) { c->### }
3860  //
3861  // accessing 'member' would result in an ambiguity. However, we
3862  // could be smart enough to qualify the member with the base
3863  // class, e.g.,
3864  //
3865  // c->B::member
3866  //
3867  // or
3868  //
3869  // c->A::member
3870 
3871  // Find results in this base class (and its bases).
3872  ShadowContextRAII Shadow(Visited);
3873  lookupInDeclContext(RD, Result, QualifiedNameLookup,
3874  /*InBaseClass=*/true);
3875  }
3876  }
3877 
3878  // Traverse the contexts of Objective-C classes.
3879  if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3880  // Traverse categories.
3881  for (auto *Cat : IFace->visible_categories()) {
3882  ShadowContextRAII Shadow(Visited);
3883  lookupInDeclContext(Cat, Result, QualifiedNameLookup,
3884  /*InBaseClass=*/false);
3885  }
3886 
3887  // Traverse protocols.
3888  for (auto *I : IFace->all_referenced_protocols()) {
3889  ShadowContextRAII Shadow(Visited);
3890  lookupInDeclContext(I, Result, QualifiedNameLookup,
3891  /*InBaseClass=*/false);
3892  }
3893 
3894  // Traverse the superclass.
3895  if (IFace->getSuperClass()) {
3896  ShadowContextRAII Shadow(Visited);
3897  lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup,
3898  /*InBaseClass=*/true);
3899  }
3900 
3901  // If there is an implementation, traverse it. We do this to find
3902  // synthesized ivars.
3903  if (IFace->getImplementation()) {
3904  ShadowContextRAII Shadow(Visited);
3905  lookupInDeclContext(IFace->getImplementation(), Result,
3906  QualifiedNameLookup, InBaseClass);
3907  }
3908  } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3909  for (auto *I : Protocol->protocols()) {
3910  ShadowContextRAII Shadow(Visited);
3911  lookupInDeclContext(I, Result, QualifiedNameLookup,
3912  /*InBaseClass=*/false);
3913  }
3914  } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3915  for (auto *I : Category->protocols()) {
3916  ShadowContextRAII Shadow(Visited);
3917  lookupInDeclContext(I, Result, QualifiedNameLookup,
3918  /*InBaseClass=*/false);
3919  }
3920 
3921  // If there is an implementation, traverse it.
3922  if (Category->getImplementation()) {
3923  ShadowContextRAII Shadow(Visited);
3924  lookupInDeclContext(Category->getImplementation(), Result,
3925  QualifiedNameLookup, /*InBaseClass=*/true);
3926  }
3927  }
3928  }
3929 
3930  void lookupInScope(Scope *S, LookupResult &Result,
3931  UnqualUsingDirectiveSet &UDirs) {
3932  // No clients run in this mode and it's not supported. Please add tests and
3933  // remove the assertion if you start relying on it.
3934  assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
3935 
3936  if (!S)
3937  return;
3938 
3939  if (!S->getEntity() ||
3940  (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) ||
3941  (S->getEntity())->isFunctionOrMethod()) {
3942  FindLocalExternScope FindLocals(Result);
3943  // Walk through the declarations in this Scope. The consumer might add new
3944  // decls to the scope as part of deserialization, so make a copy first.
3945  SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
3946  for (Decl *D : ScopeDecls) {
3947  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3948  if ((ND = Result.getAcceptableDecl(ND))) {
3949  Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3950  Visited.add(ND);
3951  }
3952  }
3953  }
3954 
3955  // FIXME: C++ [temp.local]p8
3956  DeclContext *Entity = nullptr;
3957  if (S->getEntity()) {
3958  // Look into this scope's declaration context, along with any of its
3959  // parent lookup contexts (e.g., enclosing classes), up to the point
3960  // where we hit the context stored in the next outer scope.
3961  Entity = S->getEntity();
3962  DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3963 
3964  for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3965  Ctx = Ctx->getLookupParent()) {
3966  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3967  if (Method->isInstanceMethod()) {
3968  // For instance methods, look for ivars in the method's interface.
3969  LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3970  Result.getNameLoc(),
3972  if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3973  lookupInDeclContext(IFace, IvarResult,
3974  /*QualifiedNameLookup=*/false,
3975  /*InBaseClass=*/false);
3976  }
3977  }
3978 
3979  // We've already performed all of the name lookup that we need
3980  // to for Objective-C methods; the next context will be the
3981  // outer scope.
3982  break;
3983  }
3984 
3985  if (Ctx->isFunctionOrMethod())
3986  continue;
3987 
3988  lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
3989  /*InBaseClass=*/false);
3990  }
3991  } else if (!S->getParent()) {
3992  // Look into the translation unit scope. We walk through the translation
3993  // unit's declaration context, because the Scope itself won't have all of
3994  // the declarations if we loaded a precompiled header.
3995  // FIXME: We would like the translation unit's Scope object to point to
3996  // the translation unit, so we don't need this special "if" branch.
3997  // However, doing so would force the normal C++ name-lookup code to look
3998  // into the translation unit decl when the IdentifierInfo chains would
3999  // suffice. Once we fix that problem (which is part of a more general
4000  // "don't look in DeclContexts unless we have to" optimization), we can
4001  // eliminate this.
4002  Entity = Result.getSema().Context.getTranslationUnitDecl();
4003  lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false,
4004  /*InBaseClass=*/false);
4005  }
4006 
4007  if (Entity) {
4008  // Lookup visible declarations in any namespaces found by using
4009  // directives.
4010  for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
4011  lookupInDeclContext(
4012  const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
4013  /*QualifiedNameLookup=*/false,
4014  /*InBaseClass=*/false);
4015  }
4016 
4017  // Lookup names in the parent scope.
4018  ShadowContextRAII Shadow(Visited);
4019  lookupInScope(S->getParent(), Result, UDirs);
4020  }
4021 
4022 private:
4023  VisibleDeclsRecord Visited;
4024  VisibleDeclConsumer &Consumer;
4025  bool IncludeDependentBases;
4026  bool LoadExternal;
4027 };
4028 
4030  VisibleDeclConsumer &Consumer,
4031  bool IncludeGlobalScope, bool LoadExternal) {
4032  LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
4033  LoadExternal);
4034  H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope);
4035 }
4036 
4038  VisibleDeclConsumer &Consumer,
4039  bool IncludeGlobalScope,
4040  bool IncludeDependentBases, bool LoadExternal) {
4041  LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
4042  H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope);
4043 }
4044 
4045 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
4046 /// If GnuLabelLoc is a valid source location, then this is a definition
4047 /// of an __label__ label name, otherwise it is a normal label definition
4048 /// or use.
4050  SourceLocation GnuLabelLoc) {
4051  // Do a lookup to see if we have a label with this name already.
4052  NamedDecl *Res = nullptr;
4053 
4054  if (GnuLabelLoc.isValid()) {
4055  // Local label definitions always shadow existing labels.
4056  Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
4057  Scope *S = CurScope;
4058  PushOnScopeChains(Res, S, true);
4059  return cast<LabelDecl>(Res);
4060  }
4061 
4062  // Not a GNU local label.
4063  Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
4064  // If we found a label, check to see if it is in the same context as us.
4065  // When in a Block, we don't want to reuse a label in an enclosing function.
4066  if (Res && Res->getDeclContext() != CurContext)
4067  Res = nullptr;
4068  if (!Res) {
4069  // If not forward referenced or defined already, create the backing decl.
4070  Res = LabelDecl::Create(Context, CurContext, Loc, II);
4071  Scope *S = CurScope->getFnParent();
4072  assert(S && "Not in a function?");
4073  PushOnScopeChains(Res, S, true);
4074  }
4075  return cast<LabelDecl>(Res);
4076 }
4077 
4078 //===----------------------------------------------------------------------===//
4079 // Typo correction
4080 //===----------------------------------------------------------------------===//
4081 
4083  TypoCorrection &Candidate) {
4084  Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
4085  return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
4086 }
4087 
4088 static void LookupPotentialTypoResult(Sema &SemaRef,
4089  LookupResult &Res,
4090  IdentifierInfo *Name,
4091  Scope *S, CXXScopeSpec *SS,
4093  bool EnteringContext,
4094  bool isObjCIvarLookup,
4095  bool FindHidden);
4096 
4097 /// Check whether the declarations found for a typo correction are
4098 /// visible. Set the correction's RequiresImport flag to true if none of the
4099 /// declarations are visible, false otherwise.
4100 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4101  TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4102 
4103  for (/**/; DI != DE; ++DI)
4104  if (!LookupResult::isVisible(SemaRef, *DI))
4105  break;
4106  // No filtering needed if all decls are visible.
4107  if (DI == DE) {
4108  TC.setRequiresImport(false);
4109  return;
4110  }
4111 
4112  llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4113  bool AnyVisibleDecls = !NewDecls.empty();
4114 
4115  for (/**/; DI != DE; ++DI) {
4116  if (LookupResult::isVisible(SemaRef, *DI)) {
4117  if (!AnyVisibleDecls) {
4118  // Found a visible decl, discard all hidden ones.
4119  AnyVisibleDecls = true;
4120  NewDecls.clear();
4121  }
4122  NewDecls.push_back(*DI);
4123  } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4124  NewDecls.push_back(*DI);
4125  }
4126 
4127  if (NewDecls.empty())
4128  TC = TypoCorrection();
4129  else {
4130  TC.setCorrectionDecls(NewDecls);
4131  TC.setRequiresImport(!AnyVisibleDecls);
4132  }
4133 }
4134 
4135 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
4136 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4137 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4139  NestedNameSpecifier *NNS,
4141  if (NestedNameSpecifier *Prefix = NNS->getPrefix())
4142  getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
4143  else
4144  Identifiers.clear();
4145 
4146  const IdentifierInfo *II = nullptr;
4147 
4148  switch (NNS->getKind()) {
4150  II = NNS->getAsIdentifier();
4151  break;
4152 
4154  if (NNS->getAsNamespace()->isAnonymousNamespace())
4155  return;
4156  II = NNS->getAsNamespace()->getIdentifier();
4157  break;
4158 
4160  II = NNS->getAsNamespaceAlias()->getIdentifier();
4161  break;
4162 
4165  II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
4166  break;
4167 
4170  return;
4171  }
4172 
4173  if (II)
4174  Identifiers.push_back(II);
4175 }
4176 
4178  DeclContext *Ctx, bool InBaseClass) {
4179  // Don't consider hidden names for typo correction.
4180  if (Hiding)
4181  return;
4182 
4183  // Only consider entities with identifiers for names, ignoring
4184  // special names (constructors, overloaded operators, selectors,
4185  // etc.).
4186  IdentifierInfo *Name = ND->getIdentifier();
4187  if (!Name)
4188  return;
4189 
4190  // Only consider visible declarations and declarations from modules with
4191  // names that exactly match.
4192  if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
4193  return;
4194 
4195  FoundName(Name->getName());
4196 }
4197 
4199  // Compute the edit distance between the typo and the name of this
4200  // entity, and add the identifier to the list of results.
4201  addName(Name, nullptr);
4202 }
4203 
4205  // Compute the edit distance between the typo and this keyword,
4206  // and add the keyword to the list of results.
4207  addName(Keyword, nullptr, nullptr, true);
4208 }
4209 
4210 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4211  NestedNameSpecifier *NNS, bool isKeyword) {
4212  // Use a simple length-based heuristic to determine the minimum possible
4213  // edit distance. If the minimum isn't good enough, bail out early.
4214  StringRef TypoStr = Typo->getName();
4215  unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
4216  if (MinED && TypoStr.size() / MinED < 3)
4217  return;
4218 
4219  // Compute an upper bound on the allowable edit distance, so that the
4220  // edit-distance algorithm can short-circuit.
4221  unsigned UpperBound = (TypoStr.size() + 2) / 3;
4222  unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
4223  if (ED > UpperBound) return;
4224 
4225  TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4226  if (isKeyword) TC.makeKeyword();
4227  TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
4228  addCorrection(TC);
4229 }
4230 
4231 static const unsigned MaxTypoDistanceResultSets = 5;
4232 
4234  StringRef TypoStr = Typo->getName();
4235  StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4236 
4237  // For very short typos, ignore potential corrections that have a different
4238  // base identifier from the typo or which have a normalized edit distance
4239  // longer than the typo itself.
4240  if (TypoStr.size() < 3 &&
4241  (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4242  return;
4243 
4244  // If the correction is resolved but is not viable, ignore it.
4245  if (Correction.isResolved()) {
4246  checkCorrectionVisibility(SemaRef, Correction);
4247  if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4248  return;
4249  }
4250 
4251  TypoResultList &CList =
4252  CorrectionResults[Correction.getEditDistance(false)][Name];
4253 
4254  if (!CList.empty() && !CList.back().isResolved())
4255  CList.pop_back();
4256  if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4257  std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4258  for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4259  RI != RIEnd; ++RI) {
4260  // If the Correction refers to a decl already in the result list,
4261  // replace the existing result if the string representation of Correction
4262  // comes before the current result alphabetically, then stop as there is
4263  // nothing more to be done to add Correction to the candidate set.
4264  if (RI->getCorrectionDecl() == NewND) {
4265  if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4266  *RI = Correction;
4267  return;
4268  }
4269  }
4270  }
4271  if (CList.empty() || Correction.isResolved())
4272  CList.push_back(Correction);
4273 
4274  while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4275  CorrectionResults.erase(std::prev(CorrectionResults.end()));
4276 }
4277 
4279  const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4280  SearchNamespaces = true;
4281 
4282  for (auto KNPair : KnownNamespaces)
4283  Namespaces.addNameSpecifier(KNPair.first);
4284 
4285  bool SSIsTemplate = false;
4286  if (NestedNameSpecifier *NNS =
4287  (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4288  if (const Type *T = NNS->getAsType())
4289  SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4290  }
4291  // Do not transform this into an iterator-based loop. The loop body can
4292  // trigger the creation of further types (through lazy deserialization) and
4293  // invalid iterators into this list.
4294  auto &Types = SemaRef.getASTContext().getTypes();
4295  for (unsigned I = 0; I != Types.size(); ++I) {
4296  const auto *TI = Types[I];
4297  if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4298  CD = CD->getCanonicalDecl();
4299  if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4300  !CD->isUnion() && CD->getIdentifier() &&
4301  (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4302  (CD->isBeingDefined() || CD->isCompleteDefinition()))
4303  Namespaces.addNameSpecifier(CD);
4304  }
4305  }
4306 }
4307 
4309  if (++CurrentTCIndex < ValidatedCorrections.size())
4310  return ValidatedCorrections[CurrentTCIndex];
4311 
4312  CurrentTCIndex = ValidatedCorrections.size();
4313  while (!CorrectionResults.empty()) {
4314  auto DI = CorrectionResults.begin();
4315  if (DI->second.empty()) {
4316  CorrectionResults.erase(DI);
4317  continue;
4318  }
4319 
4320  auto RI = DI->second.begin();
4321  if (RI->second.empty()) {
4322  DI->second.erase(RI);
4323  performQualifiedLookups();
4324  continue;
4325  }
4326 
4327  TypoCorrection TC = RI->second.pop_back_val();
4328  if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4329  ValidatedCorrections.push_back(TC);
4330  return ValidatedCorrections[CurrentTCIndex];
4331  }
4332  }
4333  return ValidatedCorrections[0]; // The empty correction.
4334 }
4335 
4336 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4337  IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4338  DeclContext *TempMemberContext = MemberContext;
4339  CXXScopeSpec *TempSS = SS.get();
4340 retry_lookup:
4341  LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4342  EnteringContext,
4343  CorrectionValidator->IsObjCIvarLookup,
4344  Name == Typo && !Candidate.WillReplaceSpecifier());
4345  switch (Result.getResultKind()) {
4349  if (TempSS) {
4350  // Immediately retry the lookup without the given CXXScopeSpec
4351  TempSS = nullptr;
4352  Candidate.WillReplaceSpecifier(true);
4353  goto retry_lookup;
4354  }
4355  if (TempMemberContext) {
4356  if (SS && !TempSS)
4357  TempSS = SS.get();
4358  TempMemberContext = nullptr;
4359  goto retry_lookup;
4360  }
4361  if (SearchNamespaces)
4362  QualifiedResults.push_back(Candidate);
4363  break;
4364 
4366  // We don't deal with ambiguities.
4367  break;
4368 
4369  case LookupResult::Found:
4371  // Store all of the Decls for overloaded symbols
4372  for (auto *TRD : Result)
4373  Candidate.addCorrectionDecl(TRD);
4374  checkCorrectionVisibility(SemaRef, Candidate);
4375  if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4376  if (SearchNamespaces)
4377  QualifiedResults.push_back(Candidate);
4378  break;
4379  }
4380  Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4381  return true;
4382  }
4383  return false;
4384 }
4385 
4386 void TypoCorrectionConsumer::performQualifiedLookups() {
4387  unsigned TypoLen = Typo->getName().size();
4388  for (const TypoCorrection &QR : QualifiedResults) {
4389  for (const auto &NSI : Namespaces) {
4390  DeclContext *Ctx = NSI.DeclCtx;
4391  const Type *NSType = NSI.NameSpecifier->getAsType();
4392 
4393  // If the current NestedNameSpecifier refers to a class and the
4394  // current correction candidate is the name of that class, then skip
4395  // it as it is unlikely a qualified version of the class' constructor
4396  // is an appropriate correction.
4397  if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4398  nullptr) {
4399  if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4400  continue;
4401  }
4402 
4403  TypoCorrection TC(QR);
4404  TC.ClearCorrectionDecls();
4405  TC.setCorrectionSpecifier(NSI.NameSpecifier);
4406  TC.setQualifierDistance(NSI.EditDistance);
4407  TC.setCallbackDistance(0); // Reset the callback distance
4408 
4409  // If the current correction candidate and namespace combination are
4410  // too far away from the original typo based on the normalized edit
4411  // distance, then skip performing a qualified name lookup.
4412  unsigned TmpED = TC.getEditDistance(true);
4413  if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4414  TypoLen / TmpED < 3)
4415  continue;
4416 
4417  Result.clear();
4418  Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4419  if (!SemaRef.LookupQualifiedName(Result, Ctx))
4420  continue;
4421 
4422  // Any corrections added below will be validated in subsequent
4423  // iterations of the main while() loop over the Consumer's contents.
4424  switch (Result.getResultKind()) {
4425  case LookupResult::Found:
4427  if (SS && SS->isValid()) {
4428  std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4429  std::string OldQualified;
4430  llvm::raw_string_ostream OldOStream(OldQualified);
4431  SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4432  OldOStream << Typo->getName();
4433  // If correction candidate would be an identical written qualified
4434  // identifier, then the existing CXXScopeSpec probably included a
4435  // typedef that didn't get accounted for properly.
4436  if (OldOStream.str() == NewQualified)
4437  break;
4438  }
4439  for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4440  TRD != TRDEnd; ++TRD) {
4441  if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4442  NSType ? NSType->getAsCXXRecordDecl()
4443  : nullptr,
4444  TRD.getPair()) == Sema::AR_accessible)
4445  TC.addCorrectionDecl(*TRD);
4446  }
4447  if (TC.isResolved()) {
4448  TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4449  addCorrection(TC);
4450  }
4451  break;
4452  }
4457  break;
4458  }
4459  }
4460  }
4461  QualifiedResults.clear();
4462 }
4463 
4464 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4465  ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4466  : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4467  if (NestedNameSpecifier *NNS =
4468  CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4469  llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4470  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4471 
4472  getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4473  }
4474  // Build the list of identifiers that would be used for an absolute
4475  // (from the global context) NestedNameSpecifier referring to the current
4476  // context.
4477  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4478  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4479  CurContextIdentifiers.push_back(ND->getIdentifier());
4480  }
4481 
4482  // Add the global context as a NestedNameSpecifier
4483  SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4485  DistanceMap[1].push_back(SI);
4486 }
4487 
4488 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4489  DeclContext *Start) -> DeclContextList {
4490  assert(Start && "Building a context chain from a null context");
4491  DeclContextList Chain;
4492  for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4493  DC = DC->getLookupParent()) {
4494  NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4495  if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4496  !(ND && ND->isAnonymousNamespace()))
4497  Chain.push_back(DC->getPrimaryContext());
4498  }
4499  return Chain;
4500 }
4501 
4502 unsigned
4503 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4504  DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4505  unsigned NumSpecifiers = 0;
4506  for (DeclContext *C : llvm::reverse(DeclChain)) {
4507  if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4508  NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4509  ++NumSpecifiers;
4510  } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4511  NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4512  RD->getTypeForDecl());
4513  ++NumSpecifiers;
4514  }
4515  }
4516  return NumSpecifiers;
4517 }
4518 
4519 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4520  DeclContext *Ctx) {
4521  NestedNameSpecifier *NNS = nullptr;
4522  unsigned NumSpecifiers = 0;
4523  DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4524  DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4525 
4526  // Eliminate common elements from the two DeclContext chains.
4527  for (DeclContext *C : llvm::reverse(CurContextChain)) {
4528  if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4529  break;
4530  NamespaceDeclChain.pop_back();
4531  }
4532 
4533  // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4534  NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4535 
4536  // Add an explicit leading '::' specifier if needed.
4537  if (NamespaceDeclChain.empty()) {
4538  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4539  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4540  NumSpecifiers =
4541  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4542  } else if (NamedDecl *ND =
4543  dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4544  IdentifierInfo *Name = ND->getIdentifier();
4545  bool SameNameSpecifier = false;
4546  if (std::find(CurNameSpecifierIdentifiers.begin(),
4547  CurNameSpecifierIdentifiers.end(),
4548  Name) != CurNameSpecifierIdentifiers.end()) {
4549  std::string NewNameSpecifier;
4550  llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4551  SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4552  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4553  NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4554  SpecifierOStream.flush();
4555  SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4556  }
4557  if (SameNameSpecifier || llvm::find(CurContextIdentifiers, Name) !=
4558  CurContextIdentifiers.end()) {
4559  // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4560  NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4561  NumSpecifiers =
4562  buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4563  }
4564  }
4565 
4566  // If the built NestedNameSpecifier would be replacing an existing
4567  // NestedNameSpecifier, use the number of component identifiers that
4568  // would need to be changed as the edit distance instead of the number
4569  // of components in the built NestedNameSpecifier.
4570  if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4571  SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4572  getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4573  NumSpecifiers = llvm::ComputeEditDistance(
4574  llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4575  llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4576  }
4577 
4578  SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4579  DistanceMap[NumSpecifiers].push_back(SI);
4580 }
4581 
4582 /// Perform name lookup for a possible result for typo correction.
4583 static void LookupPotentialTypoResult(Sema &SemaRef,
4584  LookupResult &Res,
4585  IdentifierInfo *Name,
4586  Scope *S, CXXScopeSpec *SS,
4587  DeclContext *MemberContext,
4588  bool EnteringContext,
4589  bool isObjCIvarLookup,
4590  bool FindHidden) {
4591  Res.suppressDiagnostics();
4592  Res.clear();
4593  Res.setLookupName(Name);
4594  Res.setAllowHidden(FindHidden);
4595  if (MemberContext) {
4596  if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4597  if (isObjCIvarLookup) {
4598  if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4599  Res.addDecl(Ivar);
4600  Res.resolveKind();
4601  return;
4602  }
4603  }
4604 
4605  if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4607  Res.addDecl(Prop);
4608  Res.resolveKind();
4609  return;
4610  }
4611  }
4612 
4613  SemaRef.LookupQualifiedName(Res, MemberContext);
4614  return;
4615  }
4616 
4617  SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4618  EnteringContext);
4619 
4620  // Fake ivar lookup; this should really be part of
4621  // LookupParsedName.
4622  if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4623  if (Method->isInstanceMethod() && Method->getClassInterface() &&
4624  (Res.empty() ||
4625  (Res.isSingleResult() &&
4627  if (ObjCIvarDecl *IV
4628  = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4629  Res.addDecl(IV);
4630  Res.resolveKind();
4631  }
4632  }
4633  }
4634 }
4635 
4636 /// Add keywords to the consumer as possible typo corrections.
4637 static void AddKeywordsToConsumer(Sema &SemaRef,
4638  TypoCorrectionConsumer &Consumer,
4640  bool AfterNestedNameSpecifier) {
4641  if (AfterNestedNameSpecifier) {
4642  // For 'X::', we know exactly which keywords can appear next.
4643  Consumer.addKeywordResult("template");
4644  if (CCC.WantExpressionKeywords)
4645  Consumer.addKeywordResult("operator");
4646  return;
4647  }
4648 
4649  if (CCC.WantObjCSuper)
4650  Consumer.addKeywordResult("super");
4651 
4652  if (CCC.WantTypeSpecifiers) {
4653  // Add type-specifier keywords to the set of results.
4654  static const char *const CTypeSpecs[] = {
4655  "char", "const", "double", "enum", "float", "int", "long", "short",
4656  "signed", "struct", "union", "unsigned", "void", "volatile",
4657  "_Complex", "_Imaginary",
4658  // storage-specifiers as well
4659  "extern", "inline", "static", "typedef"
4660  };
4661 
4662  const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4663  for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4664  Consumer.addKeywordResult(CTypeSpecs[I]);
4665 
4666  if (SemaRef.getLangOpts().C99)
4667  Consumer.addKeywordResult("restrict");
4668  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4669  Consumer.addKeywordResult("bool");
4670  else if (SemaRef.getLangOpts().C99)
4671  Consumer.addKeywordResult("_Bool");
4672 
4673  if (SemaRef.getLangOpts().CPlusPlus) {
4674  Consumer.addKeywordResult("class");
4675  Consumer.addKeywordResult("typename");
4676  Consumer.addKeywordResult("wchar_t");
4677 
4678  if (SemaRef.getLangOpts().CPlusPlus11) {
4679  Consumer.addKeywordResult("char16_t");
4680  Consumer.addKeywordResult("char32_t");
4681  Consumer.addKeywordResult("constexpr");
4682  Consumer.addKeywordResult("decltype");
4683  Consumer.addKeywordResult("thread_local");
4684  }
4685  }
4686 
4687  if (SemaRef.getLangOpts().GNUKeywords)
4688  Consumer.addKeywordResult("typeof");
4689  } else if (CCC.WantFunctionLikeCasts) {
4690  static const char *const CastableTypeSpecs[] = {
4691  "char", "double", "float", "int", "long", "short",
4692  "signed", "unsigned", "void"
4693  };
4694  for (auto *kw : CastableTypeSpecs)
4695  Consumer.addKeywordResult(kw);
4696  }
4697 
4698  if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4699  Consumer.addKeywordResult("const_cast");
4700  Consumer.addKeywordResult("dynamic_cast");
4701  Consumer.addKeywordResult("reinterpret_cast");
4702  Consumer.addKeywordResult("static_cast");
4703  }
4704 
4705  if (CCC.WantExpressionKeywords) {
4706  Consumer.addKeywordResult("sizeof");
4707  if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4708  Consumer.addKeywordResult("false");
4709  Consumer.addKeywordResult("true");
4710  }
4711 
4712  if (SemaRef.getLangOpts().CPlusPlus) {
4713  static const char *const CXXExprs[] = {
4714  "delete", "new", "operator", "throw", "typeid"
4715  };
4716  const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4717  for (unsigned I = 0; I != NumCXXExprs; ++I)
4718  Consumer.addKeywordResult(CXXExprs[I]);
4719 
4720  if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4721  cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4722  Consumer.addKeywordResult("this");
4723 
4724  if (SemaRef.getLangOpts().CPlusPlus11) {
4725  Consumer.addKeywordResult("alignof");
4726  Consumer.addKeywordResult("nullptr");
4727  }
4728  }
4729 
4730  if (SemaRef.getLangOpts().C11) {
4731  // FIXME: We should not suggest _Alignof if the alignof macro
4732  // is present.
4733  Consumer.addKeywordResult("_Alignof");
4734  }
4735  }
4736 
4737  if (CCC.WantRemainingKeywords) {
4738  if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4739  // Statements.
4740  static const char *const CStmts[] = {
4741  "do", "else", "for", "goto", "if", "return", "switch", "while" };
4742  const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4743  for (unsigned I = 0; I != NumCStmts; ++I)
4744  Consumer.addKeywordResult(CStmts[I]);
4745 
4746  if (SemaRef.getLangOpts().CPlusPlus) {
4747  Consumer.addKeywordResult("catch");
4748  Consumer.addKeywordResult("try");
4749  }
4750 
4751  if (S && S->getBreakParent())
4752  Consumer.addKeywordResult("break");
4753 
4754  if (S && S->getContinueParent())
4755  Consumer.addKeywordResult("continue");
4756 
4757  if (SemaRef.getCurFunction() &&
4758  !SemaRef.getCurFunction()->SwitchStack.empty()) {
4759  Consumer.addKeywordResult("case");
4760  Consumer.addKeywordResult("default");
4761  }
4762  } else {
4763  if (SemaRef.getLangOpts().CPlusPlus) {
4764  Consumer.addKeywordResult("namespace");
4765  Consumer.addKeywordResult("template");
4766  }
4767 
4768  if (S && S->isClassScope()) {
4769  Consumer.addKeywordResult("explicit");
4770  Consumer.addKeywordResult("friend");
4771  Consumer.addKeywordResult("mutable");
4772  Consumer.addKeywordResult("private");
4773  Consumer.addKeywordResult("protected");
4774  Consumer.addKeywordResult("public");
4775  Consumer.addKeywordResult("virtual");
4776  }
4777  }
4778 
4779  if (SemaRef.getLangOpts().CPlusPlus) {
4780  Consumer.addKeywordResult("using");
4781 
4782  if (SemaRef.getLangOpts().CPlusPlus11)
4783  Consumer.addKeywordResult("static_assert");
4784  }
4785  }
4786 }
4787 
4788 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4789  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4791  DeclContext *MemberContext, bool EnteringContext,
4792  const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4793 
4794  if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4795  DisableTypoCorrection)
4796  return nullptr;
4797 
4798  // In Microsoft mode, don't perform typo correction in a template member
4799  // function dependent context because it interferes with the "lookup into
4800  // dependent bases of class templates" feature.
4801  if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4802  isa<CXXMethodDecl>(CurContext))
4803  return nullptr;
4804 
4805  // We only attempt to correct typos for identifiers.
4806  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4807  if (!Typo)
4808  return nullptr;
4809 
4810  // If the scope specifier itself was invalid, don't try to correct
4811  // typos.
4812  if (SS && SS->isInvalid())
4813  return nullptr;
4814 
4815  // Never try to correct typos during any kind of code synthesis.
4816  if (!CodeSynthesisContexts.empty())
4817  return nullptr;
4818 
4819  // Don't try to correct 'super'.
4820  if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4821  return nullptr;
4822 
4823  // Abort if typo correction already failed for this specific typo.
4824  IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4825  if (locs != TypoCorrectionFailures.end() &&
4826  locs->second.count(TypoName.getLoc()))
4827  return nullptr;
4828 
4829  // Don't try to correct the identifier "vector" when in AltiVec mode.
4830  // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4831  // remove this workaround.
4832  if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4833  return nullptr;
4834 
4835  // Provide a stop gap for files that are just seriously broken. Trying
4836  // to correct all typos can turn into a HUGE performance penalty, causing
4837  // some files to take minutes to get rejected by the parser.
4838  unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4839  if (Limit && TyposCorrected >= Limit)
4840  return nullptr;
4841  ++TyposCorrected;
4842 
4843  // If we're handling a missing symbol error, using modules, and the
4844  // special search all modules option is used, look for a missing import.
4845  if (ErrorRecovery && getLangOpts().Modules &&
4846  getLangOpts().ModulesSearchAll) {
4847  // The following has the side effect of loading the missing module.
4848  getModuleLoader().lookupMissingImports(Typo->getName(),
4849  TypoName.getBeginLoc());
4850  }
4851 
4852  // Extend the lifetime of the callback. We delayed this until here
4853  // to avoid allocations in the hot path (which is where no typo correction
4854  // occurs). Note that CorrectionCandidateCallback is polymorphic and
4855  // initially stack-allocated.
4856  std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
4857  auto Consumer = std::make_unique<TypoCorrectionConsumer>(
4858  *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext,
4859  EnteringContext);
4860 
4861  // Perform name lookup to find visible, similarly-named entities.
4862  bool IsUnqualifiedLookup = false;
4863  DeclContext *QualifiedDC = MemberContext;
4864  if (MemberContext) {
4865  LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4866 
4867  // Look in qualified interfaces.
4868  if (OPT) {
4869  for (auto *I : OPT->quals())
4870  LookupVisibleDecls(I, LookupKind, *Consumer);
4871  }
4872  } else if (SS && SS->isSet()) {
4873  QualifiedDC = computeDeclContext(*SS, EnteringContext);
4874  if (!QualifiedDC)
4875  return nullptr;
4876 
4877  LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4878  } else {
4879  IsUnqualifiedLookup = true;
4880  }
4881 
4882  // Determine whether we are going to search in the various namespaces for
4883  // corrections.
4884  bool SearchNamespaces
4885  = getLangOpts().CPlusPlus &&
4886  (IsUnqualifiedLookup || (SS && SS->isSet()));
4887 
4888  if (IsUnqualifiedLookup || SearchNamespaces) {
4889  // For unqualified lookup, look through all of the names that we have
4890  // seen in this translation unit.
4891  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4892  for (const auto &I : Context.Idents)
4893  Consumer->FoundName(I.getKey());
4894 
4895  // Walk through identifiers in external identifier sources.
4896  // FIXME: Re-add the ability to skip very unlikely potential corrections.
4897  if (IdentifierInfoLookup *External
4898  = Context.Idents.getExternalIdentifierLookup()) {
4899  std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4900  do {
4901  StringRef Name = Iter->Next();
4902  if (Name.empty())
4903  break;
4904 
4905  Consumer->FoundName(Name);
4906  } while (true);
4907  }
4908  }
4909 
4910  AddKeywordsToConsumer(*this, *Consumer, S,
4911  *Consumer->getCorrectionValidator(),
4912  SS && SS->isNotEmpty());
4913 
4914  // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4915  // to search those namespaces.
4916  if (SearchNamespaces) {
4917  // Load any externally-known namespaces.
4918  if (ExternalSource && !LoadedExternalKnownNamespaces) {
4919  SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4920  LoadedExternalKnownNamespaces = true;
4921  ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4922  for (auto *N : ExternalKnownNamespaces)
4923  KnownNamespaces[N] = true;
4924  }
4925 
4926  Consumer->addNamespaces(KnownNamespaces);
4927  }
4928 
4929  return Consumer;
4930 }
4931 
4932 /// Try to "correct" a typo in the source code by finding
4933 /// visible declarations whose names are similar to the name that was
4934 /// present in the source code.
4935 ///
4936 /// \param TypoName the \c DeclarationNameInfo structure that contains
4937 /// the name that was present in the source code along with its location.
4938 ///
4939 /// \param LookupKind the name-lookup criteria used to search for the name.
4940 ///
4941 /// \param S the scope in which name lookup occurs.
4942 ///
4943 /// \param SS the nested-name-specifier that precedes the name we're
4944 /// looking for, if present.
4945 ///
4946 /// \param CCC A CorrectionCandidateCallback object that provides further
4947 /// validation of typo correction candidates. It also provides flags for
4948 /// determining the set of keywords permitted.
4949 ///
4950 /// \param MemberContext if non-NULL, the context in which to look for
4951 /// a member access expression.
4952 ///
4953 /// \param EnteringContext whether we're entering the context described by
4954 /// the nested-name-specifier SS.
4955 ///
4956 /// \param OPT when non-NULL, the search for visible declarations will
4957 /// also walk the protocols in the qualified interfaces of \p OPT.
4958 ///
4959 /// \returns a \c TypoCorrection containing the corrected name if the typo
4960 /// along with information such as the \c NamedDecl where the corrected name
4961 /// was declared, and any additional \c NestedNameSpecifier needed to access
4962 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4964  Sema::LookupNameKind LookupKind,
4965  Scope *S, CXXScopeSpec *SS,
4967  CorrectTypoKind Mode,
4968  DeclContext *MemberContext,
4969  bool EnteringContext,
4970  const ObjCObjectPointerType *OPT,
4971  bool RecordFailure) {
4972  // Always let the ExternalSource have the first chance at correction, even
4973  // if we would otherwise have given up.
4974  if (ExternalSource) {
4975  if (TypoCorrection Correction =
4976  ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC,
4977  MemberContext, EnteringContext, OPT))
4978  return Correction;
4979  }
4980 
4981  // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4982  // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4983  // some instances of CTC_Unknown, while WantRemainingKeywords is true
4984  // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4985  bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
4986 
4987  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4988  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
4989  MemberContext, EnteringContext,
4990  OPT, Mode == CTK_ErrorRecovery);
4991 
4992  if (!Consumer)
4993  return TypoCorrection();
4994 
4995  // If we haven't found anything, we're done.
4996  if (Consumer->empty())
4997  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4998 
4999  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5000  // is not more that about a third of the length of the typo's identifier.
5001  unsigned ED = Consumer->getBestEditDistance(true);
5002  unsigned TypoLen = Typo->getName().size();
5003  if (ED > 0 && TypoLen / ED < 3)
5004  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5005 
5006  TypoCorrection BestTC = Consumer->getNextCorrection();
5007  TypoCorrection SecondBestTC = Consumer->getNextCorrection();
5008  if (!BestTC)
5009  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5010 
5011  ED = BestTC.getEditDistance();
5012 
5013  if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
5014  // If this was an unqualified lookup and we believe the callback
5015  // object wouldn't have filtered out possible corrections, note
5016  // that no correction was found.
5017  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5018  }
5019 
5020  // If only a single name remains, return that result.
5021  if (!SecondBestTC ||
5022  SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
5023  const TypoCorrection &Result = BestTC;
5024 
5025  // Don't correct to a keyword that's the same as the typo; the keyword
5026  // wasn't actually in scope.
5027  if (ED == 0 && Result.isKeyword())
5028  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5029 
5030  TypoCorrection TC = Result;
5031  TC.setCorrectionRange(SS, TypoName);
5032  checkCorrectionVisibility(*this, TC);
5033  return TC;
5034  } else if (SecondBestTC && ObjCMessageReceiver) {
5035  // Prefer 'super' when we're completing in a message-receiver
5036  // context.
5037 
5038  if (BestTC.getCorrection().getAsString() != "super") {
5039  if (SecondBestTC.getCorrection().getAsString() == "super")
5040  BestTC = SecondBestTC;
5041  else if ((*Consumer)["super"].front().isKeyword())
5042  BestTC = (*Consumer)["super"].front();
5043  }
5044  // Don't correct to a keyword that's the same as the typo; the keyword
5045  // wasn't actually in scope.
5046  if (BestTC.getEditDistance() == 0 ||
5047  BestTC.getCorrection().getAsString() != "super")
5048  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
5049 
5050  BestTC.setCorrectionRange(SS, TypoName);
5051  return BestTC;
5052  }
5053 
5054  // Record the failure's location if needed and return an empty correction. If
5055  // this was an unqualified lookup and we believe the callback object did not
5056  // filter out possible corrections, also cache the failure for the typo.
5057  return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
5058 }
5059 
5060 /// Try to "correct" a typo in the source code by finding
5061 /// visible declarations whose names are similar to the name that was
5062 /// present in the source code.
5063 ///
5064 /// \param TypoName the \c DeclarationNameInfo structure that contains
5065 /// the name that was present in the source code along with its location.
5066 ///
5067 /// \param LookupKind the name-lookup criteria used to search for the name.
5068 ///
5069 /// \param S the scope in which name lookup occurs.
5070 ///
5071 /// \param SS the nested-name-specifier that precedes the name we're
5072 /// looking for, if present.
5073 ///
5074 /// \param CCC A CorrectionCandidateCallback object that provides further
5075 /// validation of typo correction candidates. It also provides flags for
5076 /// determining the set of keywords permitted.
5077 ///
5078 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
5079 /// diagnostics when the actual typo correction is attempted.
5080 ///
5081 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
5082 /// Expr from a typo correction candidate.
5083 ///
5084 /// \param MemberContext if non-NULL, the context in which to look for
5085 /// a member access expression.
5086 ///
5087 /// \param EnteringContext whether we're entering the context described by
5088 /// the nested-name-specifier SS.
5089 ///
5090 /// \param OPT when non-NULL, the search for visible declarations will
5091 /// also walk the protocols in the qualified interfaces of \p OPT.
5092 ///
5093 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
5094 /// Expr representing the result of performing typo correction, or nullptr if
5095 /// typo correction is not possible. If nullptr is returned, no diagnostics will
5096 /// be emitted and it is the responsibility of the caller to emit any that are
5097 /// needed.
5099  const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
5102  DeclContext *MemberContext, bool EnteringContext,
5103  const ObjCObjectPointerType *OPT) {
5104  auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC,
5105  MemberContext, EnteringContext,
5106  OPT, Mode == CTK_ErrorRecovery);
5107 
5108  // Give the external sema source a chance to correct the typo.
5109  TypoCorrection ExternalTypo;
5110  if (ExternalSource && Consumer) {
5111  ExternalTypo = ExternalSource->CorrectTypo(
5112  TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
5113  MemberContext, EnteringContext, OPT);
5114  if (ExternalTypo)
5115  Consumer->addCorrection(ExternalTypo);
5116  }
5117 
5118  if (!Consumer || Consumer->empty())
5119  return nullptr;
5120 
5121  // Make sure the best edit distance (prior to adding any namespace qualifiers)
5122  // is not more that about a third of the length of the typo's identifier.
5123  unsigned ED = Consumer->getBestEditDistance(true);
5124  IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5125  if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
5126  return nullptr;
5127 
5128  ExprEvalContexts.back().NumTypos++;
5129  return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
5130 }
5131 
5133  if (!CDecl) return;
5134 
5135  if (isKeyword())
5136  CorrectionDecls.clear();
5137 
5138  CorrectionDecls.push_back(CDecl);
5139 
5140  if (!CorrectionName)
5141  CorrectionName = CDecl->getDeclName();
5142 }
5143 
5144 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
5145  if (CorrectionNameSpec) {
5146  std::string tmpBuffer;
5147  llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5148  CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
5149  PrefixOStream << CorrectionName;
5150  return PrefixOStream.str();
5151  }
5152 
5153  return CorrectionName.getAsString();
5154 }
5155 
5157  const TypoCorrection &candidate) {
5158  if (!candidate.isResolved())
5159  return true;
5160 
5161  if (candidate.isKeyword())
5162  return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
5163  WantRemainingKeywords || WantObjCSuper;
5164 
5165  bool HasNonType = false;
5166  bool HasStaticMethod = false;
5167  bool HasNonStaticMethod = false;
5168  for (Decl *D : candidate) {
5169  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
5170  D = FTD->getTemplatedDecl();
5171  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
5172  if (Method->isStatic())
5173  HasStaticMethod = true;
5174  else
5175  HasNonStaticMethod = true;
5176  }
5177  if (!isa<TypeDecl>(D))
5178  HasNonType = true;
5179  }
5180 
5181  if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5182  !candidate.getCorrectionSpecifier())
5183  return false;
5184 
5185  return WantTypeSpecifiers || HasNonType;
5186 }
5187 
5189  bool HasExplicitTemplateArgs,
5190  MemberExpr *ME)
5191  : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5192  CurContext(SemaRef.CurContext), MemberFn(ME) {
5193  WantTypeSpecifiers = false;
5194  WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5195  !HasExplicitTemplateArgs && NumArgs == 1;
5196  WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5197  WantRemainingKeywords = false;
5198 }
5199 
5201  if (!candidate.getCorrectionDecl())
5202  return candidate.isKeyword();
5203 
5204  for (auto *C : candidate) {
5205  FunctionDecl *FD = nullptr;
5206  NamedDecl *ND = C->getUnderlyingDecl();
5207  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
5208  FD = FTD->getTemplatedDecl();
5209  if (!HasExplicitTemplateArgs && !FD) {
5210  if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
5211  // If the Decl is neither a function nor a template function,
5212  // determine if it is a pointer or reference to a function. If so,
5213  // check against the number of arguments expected for the pointee.
5214  QualType ValType = cast<ValueDecl>(ND)->getType();
5215  if (ValType.isNull())
5216  continue;
5217  if (ValType->isAnyPointerType() || ValType->isReferenceType())
5218  ValType = ValType->getPointeeType();
5219  if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5220  if (FPT->getNumParams() == NumArgs)
5221  return true;
5222  }
5223  }
5224 
5225  // A typo for a function-style cast can look like a function call in C++.
5226  if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr
5227  : isa<TypeDecl>(ND)) &&
5228  CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5229  // Only a class or class template can take two or more arguments.
5230  return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND);
5231 
5232  // Skip the current candidate if it is not a FunctionDecl or does not accept
5233  // the current number of arguments.
5234  if (!FD || !(FD->getNumParams() >= NumArgs &&
5235  FD->getMinRequiredArguments() <= NumArgs))
5236  continue;
5237 
5238  // If the current candidate is a non-static C++ method, skip the candidate
5239  // unless the method being corrected--or the current DeclContext, if the
5240  // function being corrected is not a method--is a method in the same class
5241  // or a descendent class of the candidate's parent class.
5242  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
5243  if (MemberFn || !MD->isStatic()) {
5244  CXXMethodDecl *CurMD =
5245  MemberFn
5246  ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
5247  : dyn_cast_or_null<CXXMethodDecl>(CurContext);
5248  CXXRecordDecl *CurRD =
5249  CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5250  CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5251  if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5252  continue;
5253  }
5254  }
5255  return true;
5256  }
5257  return false;
5258 }
5259 
5260 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5261  const PartialDiagnostic &TypoDiag,
5262  bool ErrorRecovery) {
5263  diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5264  ErrorRecovery);
5265 }
5266 
5267 /// Find which declaration we should import to provide the definition of
5268 /// the given declaration.
5270  if (VarDecl *VD = dyn_cast<VarDecl>(D))
5271  return VD->getDefinition();
5272  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5273  return FD->getDefinition();
5274  if (TagDecl *TD = dyn_cast<TagDecl>(D))
5275  return TD->getDefinition();
5276  // The first definition for this ObjCInterfaceDecl might be in the TU
5277  // and not associated with any module. Use the one we know to be complete
5278  // and have just seen in a module.
5279  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5280  return ID;
5281  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5282  return PD->getDefinition();
5283  if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5284  if (NamedDecl *TTD = TD->getTemplatedDecl())
5285  return getDefinitionToImport(TTD);
5286  return nullptr;
5287 }
5288 
5290  MissingImportKind MIK, bool Recover) {
5291  // Suggest importing a module providing the definition of this entity, if
5292  // possible.
5293  NamedDecl *Def = getDefinitionToImport(Decl);
5294  if (!Def)
5295  Def = Decl;
5296 
5297  Module *Owner = getOwningModule(Def);
5298  assert(Owner && "definition of hidden declaration is not in a module");
5299 
5300  llvm::SmallVector<Module*, 8> OwningModules;
5301  OwningModules.push_back(Owner);
5302  auto Merged = Context.getModulesWithMergedDefinition(Def);
5303  OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5304 
5305  diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
5306  Recover);
5307 }
5308 
5309 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5310 /// suggesting the addition of a #include of the specified file.
5312  const FileEntry *E,
5313  llvm::StringRef IncludingFile) {
5314  bool IsSystem = false;
5316  E, IncludingFile, &IsSystem);
5317  return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5318 }
5319 
5321  SourceLocation DeclLoc,
5322  ArrayRef<Module *> Modules,
5323  MissingImportKind MIK, bool Recover) {
5324  assert(!Modules.empty());
5325 
5326  auto NotePrevious = [&] {
5327  unsigned DiagID;
5328  switch (MIK) {
5329  case MissingImportKind::Declaration:
5330  DiagID = diag::note_previous_declaration;
5331  break;
5332  case MissingImportKind::Definition:
5333  DiagID = diag::note_previous_definition;
5334  break;
5335  case MissingImportKind::DefaultArgument:
5336  DiagID = diag::note_default_argument_declared_here;
5337  break;
5338  case MissingImportKind::ExplicitSpecialization:
5339  DiagID = diag::note_explicit_specialization_declared_here;
5340  break;
5341  case MissingImportKind::PartialSpecialization:
5342  DiagID = diag::note_partial_specialization_declared_here;
5343  break;
5344  }
5345  Diag(DeclLoc, DiagID);
5346  };
5347 
5348  // Weed out duplicates from module list.
5349  llvm::SmallVector<Module*, 8> UniqueModules;
5350  llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5351  for (auto *M : Modules) {
5352  if (M->Kind == Module::GlobalModuleFragment)
5353  continue;
5354  if (UniqueModuleSet.insert(M).second)
5355  UniqueModules.push_back(M);
5356  }
5357 
5358  llvm::StringRef IncludingFile;
5359  if (const FileEntry *FE =
5360  SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc)))
5361  IncludingFile = FE->tryGetRealPathName();
5362 
5363  if (UniqueModules.empty()) {
5364  // All candidates were global module fragments. Try to suggest a #include.
5365  const FileEntry *E =
5366  PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, Modules[0], DeclLoc);
5367  // FIXME: Find a smart place to suggest inserting a #include, and add
5368  // a FixItHint there.
5369  Diag(UseLoc, diag::err_module_unimported_use_global_module_fragment)
5370  << (int)MIK << Decl << !!E
5371  << (E ? getIncludeStringForHeader(PP, E, IncludingFile) : "");
5372  // Produce a "previous" note if it will point to a header rather than some
5373  // random global module fragment.
5374  // FIXME: Suppress the note backtrace even under
5375  // -fdiagnostics-show-note-include-stack.
5376  if (E)
5377  NotePrevious();
5378  if (Recover)
5379  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5380  return;
5381  }
5382 
5383  Modules = UniqueModules;
5384 
5385  if (Modules.size() > 1) {
5386  std::string ModuleList;
5387  unsigned N = 0;
5388  for (Module *M : Modules) {
5389  ModuleList += "\n ";
5390  if (++N == 5 && N != Modules.size()) {
5391  ModuleList += "[...]";
5392  break;
5393  }
5394  ModuleList += M->getFullModuleName();
5395  }
5396 
5397  Diag(UseLoc, diag::err_module_unimported_use_multiple)
5398  << (int)MIK << Decl << ModuleList;
5399  } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5400  UseLoc, Modules[0], DeclLoc)) {
5401  // The right way to make the declaration visible is to include a header;
5402  // suggest doing so.
5403  //
5404  // FIXME: Find a smart place to suggest inserting a #include, and add
5405  // a FixItHint there.
5406  Diag(UseLoc, diag::err_module_unimported_use_header)
5407  << (int)MIK << Decl << Modules[0]->getFullModuleName()
5408  << getIncludeStringForHeader(PP, E, IncludingFile);
5409  } else {
5410  // FIXME: Add a FixItHint that imports the corresponding module.
5411  Diag(UseLoc, diag::err_module_unimported_use)
5412  << (int)MIK << Decl << Modules[0]->getFullModuleName();
5413  }
5414 
5415  NotePrevious();
5416 
5417  // Try to recover by implicitly importing this module.
5418  if (Recover)
5419  createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5420 }
5421 
5422 /// Diagnose a successfully-corrected typo. Separated from the correction
5423 /// itself to allow external validation of the result, etc.
5424 ///
5425 /// \param Correction The result of performing typo correction.
5426 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5427 /// string added to it (and usually also a fixit).
5428 /// \param PrevNote A note to use when indicating the location of the entity to
5429 /// which we are correcting. Will have the correction string added to it.
5430 /// \param ErrorRecovery If \c true (the default), the caller is going to
5431 /// recover from the typo as if the corrected string had been typed.
5432 /// In this case, \c PDiag must be an error, and we will attach a fixit
5433 /// to it.
5434 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5435  const PartialDiagnostic &TypoDiag,
5436  const PartialDiagnostic &PrevNote,
5437  bool ErrorRecovery) {
5438  std::string CorrectedStr = Correction.getAsString(getLangOpts());
5439  std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5441  Correction.getCorrectionRange(), CorrectedStr);
5442 
5443  // Maybe we're just missing a module import.
5444  if (Correction.requiresImport()) {
5445  NamedDecl *Decl = Correction.getFoundDecl();
5446  assert(Decl && "import required but no declaration to import");
5447 
5448  diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5449  MissingImportKind::Declaration, ErrorRecovery);
5450  return;
5451  }
5452 
5453  Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5454  << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5455 
5456  NamedDecl *ChosenDecl =
5457  Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5458  if (PrevNote.getDiagID() && ChosenDecl)
5459  Diag(ChosenDecl->getLocation(), PrevNote)
5460  << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5461 
5462  // Add any extra diagnostics.
5463  for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5464  Diag(Correction.getCorrectionRange().getBegin(), PD);
5465 }
5466 
5467 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5469  TypoRecoveryCallback TRC) {
5470  assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5471  auto TE = new (Context) TypoExpr(Context.DependentTy);
5472  auto &State = DelayedTypos[TE];
5473  State.Consumer = std::move(TCC);
5474  State.DiagHandler = std::move(TDG);
5475  State.RecoveryHandler = std::move(TRC);
5476  if (TE)
5477  TypoExprs.push_back(TE);
5478  return TE;
5479 }
5480 
5481 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5482  auto Entry = DelayedTypos.find(TE);
5483  assert(Entry != DelayedTypos.end() &&
5484  "Failed to get the state for a TypoExpr!");
5485  return Entry->second;
5486 }
5487 
5489  DelayedTypos.erase(TE);
5490 }
5491 
5493  DeclarationNameInfo Name(II, IILoc);
5494  LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5495  R.suppressDiagnostics();
5496  R.setHideTags(false);
5497  LookupName(R, S);
5498  R.dump();
5499 }
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:1605
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:1756
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:1903
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:1134
no exception specification
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2575
A (possibly-)qualified type.
Definition: Type.h:643
Simple class containing the result of Sema::CorrectTypo.
base_class_range bases()
Definition: DeclCXX.h:779
ValueDecl * getMemberDecl() const
Retrieve the member declaration to which this expression refers.
Definition: Expr.h:2889
bool hasVisibleDeclarationSlow(const NamedDecl *D, llvm::SmallVectorImpl< Module *> *Modules)
CorrectTypoKind
Definition: Sema.h:3472
virtual unsigned RankCandidate(const TypoCorrection &candidate)
Method used by Sema::CorrectTypo to assign an "edit distance" rank to a candidate (where a lower valu...
Template argument deduction was successful.
Definition: Sema.h:7287
Defines the clang::FileManager interface and associated types.
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3254
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:3288
Filter makeFilter()
Create a filter for this result set.
Definition: Lookup.h:682
CXXMethodDecl * LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals)
Look up the moving assignment operator for the given class.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3393
Provides information about an attempted template argument deduction, whose success or failure was des...
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:518
LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases, bool LoadExternal)
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:885
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:883
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:7630
static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D, llvm::SmallVectorImpl< Module *> *Modules, Filter F)
Decl * getPreviousDecl()
Retrieve the previous declaration that declares the same entity as this declaration, or NULL if there is no previous declaration.
Definition: DeclBase.h:960
NamedDecl * getDecl() const
The base class of the type hierarchy.
Definition: Type.h:1436
SourceLocation getBeginLoc() const
getBeginLoc - Retrieve the location of the first token.
MissingImportKind
Kinds of missing import.
Definition: Sema.h:2336
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:3301
Ambiguous candidates found.
Definition: Overload.h:59
NamedDecl * getParam(unsigned Idx)
Definition: DeclTemplate.h:132
decl_iterator begin()
AccessSpecifier
A C++ access specifier (public, private, protected), plus the special value "none" which means differ...
Definition: Specifiers.h:113
const NestedNameSpecifier * Specifier
Look up of a name that precedes the &#39;::&#39; scope resolution operator in C++.
Definition: Sema.h:3270
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:1117
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:3326
unsigned getIdentifierNamespace() const
Definition: DeclBase.h:799
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2528
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:3210
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:3274
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:822
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:6857
PrintingPolicy getPrintingPolicy() const
Retrieve a suitable printing policy for diagnostics.
Definition: Sema.h:2369
static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last)
Determine whether the given set of member declarations contains only static members, nested types, and enumerators.
bool isInObjcMethodScope() const
isInObjcMethodScope - Return true if this scope is, or is contained in, an Objective-C method body...
Definition: Scope.h:356
Represents an empty template argument, e.g., one that has not been deduced.
Definition: TemplateBase.h:56
Extra information about a function prototype.
Definition: Type.h:3805
static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class)
Determine whether we can declare a special member function within the class at this point...
Definition: SemaLookup.cpp:876
bool needsImplicitCopyAssignment() const
Determine whether this class needs an implicit copy assignment operator to be lazily declared...
Definition: DeclCXX.h:1068
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:3283
Represents a parameter to a function.
Definition: Decl.h:1572
Defines the clang::Expr interface and subclasses for C++ expressions.
void addKeywordResult(StringRef Keyword)
static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR, IdentifierInfo *II, const unsigned FctIndex, const unsigned Len)
When trying to resolve a function name, if isOpenCLBuiltin() returns a non-null <Index, Len> pair, then the name is referencing an OpenCL builtin function.
Definition: SemaLookup.cpp:751
void setMethod(CXXMethodDecl *MD)
Definition: Sema.h:1135
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:3634
bool LookupInSuper(LookupResult &R, CXXRecordDecl *Class)
Perform qualified name lookup into all base classes of the given class.
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:297
bool Encloses(const DeclContext *DC) const
Determine whether this declaration context encloses the declaration context DC.
Definition: DeclBase.cpp:1159
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3806
Represents a class template specialization, which refers to a class template with a given set of temp...
One of these records is kept for each identifier that is lexed.
Name lookup results in an ambiguity; use getAmbiguityKind to figure out what kind of ambiguity we hav...
Definition: Lookup.h:73
bool isStr(const char(&Str)[StrLen]) const
Return true if this is the identifier for the specified string.
std::string getQuoted(const LangOptions &LO) const
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:160
DeclarationName getCorrection() const
Gets the DeclarationName of the typo correction.
The results of name lookup within a DeclContext.
Definition: DeclBase.h:1195
LineState State
The template argument is an integral value stored in an llvm::APSInt that was provided for an integra...
Definition: TemplateBase.h:71
TemplateDecl * getAsTemplateDecl() const
Retrieve the underlying template declaration that this template name refers to, if known...
Base class for callback objects used by Sema::CorrectTypo to check the validity of a potential typo c...
sema::BlockScopeInfo * getCurBlock()
Retrieve the current block, if any.
Definition: Sema.cpp:1792
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:1226
bool isReferenceType() const
Definition: Type.h:6402
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:1752
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
void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx, Sema::LookupNameKind Kind, bool IncludeGlobalScope)
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:49