C++ SourceLocation::isValid方法代码示例

/// \brief Build an Objective-C instance message expression.
///
/// This routine takes care of both normal instance messages and
/// instance messages to the superclass instance.
///
/// \param Receiver The expression that computes the object that will
/// receive this message. This may be empty, in which case we are
/// sending to the superclass instance and \p SuperLoc must be a valid
/// source location.
///
/// \param ReceiverType The (static) type of the object receiving the
/// message. When a \p Receiver expression is provided, this is the
/// same type as that expression. For a superclass instance send, this
/// is a pointer to the type of the superclass.
///
/// \param SuperLoc The location of the "super" keyword in a
/// superclass instance message.
///
/// \param Sel The selector to which the message is being sent.
///
/// \param Method The method that this instance message is invoking, if
/// already known.
///
/// \param LBracLoc The location of the opening square bracket ']'.
///
/// \param RBrac The location of the closing square bracket ']'.
///
/// \param Args The message arguments.
Sema::OwningExprResult Sema::BuildInstanceMessage(ExprArg ReceiverE,
                                                  QualType ReceiverType,
                                                  SourceLocation SuperLoc,
                                                  Selector Sel,
                                                  ObjCMethodDecl *Method,
                                                  SourceLocation LBracLoc, 
                                                  SourceLocation RBracLoc,
                                                  MultiExprArg ArgsIn) {
  // If we have a receiver expression, perform appropriate promotions
  // and determine receiver type.
  Expr *Receiver = ReceiverE.takeAs<Expr>();
  if (Receiver) {
    if (Receiver->isTypeDependent()) {
      // If the receiver is type-dependent, we can't type-check anything
      // at this point. Build a dependent expression.
      unsigned NumArgs = ArgsIn.size();
      Expr **Args = reinterpret_cast<Expr **>(ArgsIn.release());
      assert(SuperLoc.isInvalid() && "Message to super with dependent type");
      return Owned(ObjCMessageExpr::Create(Context, Context.DependentTy,
                                           LBracLoc, Receiver, Sel, 
                                           /*Method=*/0, Args, NumArgs, 
                                           RBracLoc));
    }

    // If necessary, apply function/array conversion to the receiver.
    // C99 6.7.5.3p[7,8].
    DefaultFunctionArrayLvalueConversion(Receiver);
    ReceiverType = Receiver->getType();
  }

  // The location of the receiver.
  SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();

  if (!Method) {
    // Handle messages to id.
    bool receiverIsId = ReceiverType->isObjCIdType();
    if (receiverIsId || ReceiverType->isBlockPointerType() ||
        (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
      Method = LookupInstanceMethodInGlobalPool(Sel, 
                                                SourceRange(LBracLoc, RBracLoc),
                                                receiverIsId);
      if (!Method)
        Method = LookupFactoryMethodInGlobalPool(Sel, 
                                                 SourceRange(LBracLoc, RBracLoc),
                                                 receiverIsId);
    } else if (ReceiverType->isObjCClassType() ||
               ReceiverType->isObjCQualifiedClassType()) {
      // Handle messages to Class.
      if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
        if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
          // First check the public methods in the class interface.
          Method = ClassDecl->lookupClassMethod(Sel);

          if (!Method)
            Method = LookupPrivateClassMethod(Sel, ClassDecl);

          // FIXME: if we still haven't found a method, we need to look in
          // protocols (if we have qualifiers).
        }
        if (Method && DiagnoseUseOfDecl(Method, Loc))
          return ExprError();
      }
      if (!Method) {
        // If not messaging 'self', look for any factory method named 'Sel'.
        if (!Receiver || !isSelfExpr(Receiver)) {
          Method = LookupFactoryMethodInGlobalPool(Sel, 
                                               SourceRange(LBracLoc, RBracLoc),
                                                   true);
          if (!Method) {
            // If no class (factory) method was found, check if an _instance_
            // method of the same name exists in the root class only.
            Method = LookupInstanceMethodInGlobalPool(Sel,
//.........这里部分代码省略.........

/// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
/// "TheDeclarator" is the declarator that this will be added to.
DeclaratorChunk DeclaratorChunk::getFunction(bool hasProto,
                                             bool isAmbiguous,
                                             SourceLocation LParenLoc,
                                             ParamInfo *Params,
                                             unsigned NumParams,
                                             SourceLocation EllipsisLoc,
                                             SourceLocation RParenLoc,
                                             unsigned TypeQuals,
                                             bool RefQualifierIsLvalueRef,
                                             SourceLocation RefQualifierLoc,
                                             SourceLocation ConstQualifierLoc,
                                             SourceLocation
                                                 VolatileQualifierLoc,
                                             SourceLocation
                                                 RestrictQualifierLoc,
                                             SourceLocation MutableLoc,
                                             ExceptionSpecificationType
                                                 ESpecType,
                                             SourceLocation ESpecLoc,
                                             ParsedType *Exceptions,
                                             SourceRange *ExceptionRanges,
                                             unsigned NumExceptions,
                                             Expr *NoexceptExpr,
                                             CachedTokens *ExceptionSpecTokens,
                                             SourceLocation LocalRangeBegin,
                                             SourceLocation LocalRangeEnd,
                                             Declarator &TheDeclarator,
                                             TypeResult TrailingReturnType) {
  assert(!(TypeQuals & DeclSpec::TQ_atomic) &&
         "function cannot have _Atomic qualifier");

  DeclaratorChunk I;
  I.Kind                        = Function;
  I.Loc                         = LocalRangeBegin;
  I.EndLoc                      = LocalRangeEnd;
  I.Fun.AttrList                = nullptr;
  I.Fun.hasPrototype            = hasProto;
  I.Fun.isVariadic              = EllipsisLoc.isValid();
  I.Fun.isAmbiguous             = isAmbiguous;
  I.Fun.LParenLoc               = LParenLoc.getRawEncoding();
  I.Fun.EllipsisLoc             = EllipsisLoc.getRawEncoding();
  I.Fun.RParenLoc               = RParenLoc.getRawEncoding();
  I.Fun.DeleteParams            = false;
  I.Fun.TypeQuals               = TypeQuals;
  I.Fun.NumParams               = NumParams;
  I.Fun.Params                  = nullptr;
  I.Fun.RefQualifierIsLValueRef = RefQualifierIsLvalueRef;
  I.Fun.RefQualifierLoc         = RefQualifierLoc.getRawEncoding();
  I.Fun.ConstQualifierLoc       = ConstQualifierLoc.getRawEncoding();
  I.Fun.VolatileQualifierLoc    = VolatileQualifierLoc.getRawEncoding();
  I.Fun.RestrictQualifierLoc    = RestrictQualifierLoc.getRawEncoding();
  I.Fun.MutableLoc              = MutableLoc.getRawEncoding();
  I.Fun.ExceptionSpecType       = ESpecType;
  I.Fun.ExceptionSpecLoc        = ESpecLoc.getRawEncoding();
  I.Fun.NumExceptions           = 0;
  I.Fun.Exceptions              = nullptr;
  I.Fun.NoexceptExpr            = nullptr;
  I.Fun.HasTrailingReturnType   = TrailingReturnType.isUsable() ||
                                  TrailingReturnType.isInvalid();
  I.Fun.TrailingReturnType      = TrailingReturnType.get();

  assert(I.Fun.TypeQuals == TypeQuals && "bitfield overflow");
  assert(I.Fun.ExceptionSpecType == ESpecType && "bitfield overflow");

  // new[] a parameter array if needed.
  if (NumParams) {
    // If the 'InlineParams' in Declarator is unused and big enough, put our
    // parameter list there (in an effort to avoid new/delete traffic).  If it
    // is already used (consider a function returning a function pointer) or too
    // small (function with too many parameters), go to the heap.
    if (!TheDeclarator.InlineParamsUsed &&
        NumParams <= llvm::array_lengthof(TheDeclarator.InlineParams)) {
      I.Fun.Params = TheDeclarator.InlineParams;
      I.Fun.DeleteParams = false;
      TheDeclarator.InlineParamsUsed = true;
    } else {
      I.Fun.Params = new DeclaratorChunk::ParamInfo[NumParams];
      I.Fun.DeleteParams = true;
    }
    memcpy(I.Fun.Params, Params, sizeof(Params[0]) * NumParams);
  }

  // Check what exception specification information we should actually store.
  switch (ESpecType) {
  default: break; // By default, save nothing.
  case EST_Dynamic:
    // new[] an exception array if needed
    if (NumExceptions) {
      I.Fun.NumExceptions = NumExceptions;
      I.Fun.Exceptions = new DeclaratorChunk::TypeAndRange[NumExceptions];
      for (unsigned i = 0; i != NumExceptions; ++i) {
        I.Fun.Exceptions[i].Ty = Exceptions[i];
        I.Fun.Exceptions[i].Range = ExceptionRanges[i];
      }
    }
    break;

  case EST_ComputedNoexcept:
//.........这里部分代码省略.........

// #pragma unused(identifier)
void PragmaUnusedHandler::HandlePragma(Preprocessor &PP, Token &UnusedTok) {
  // FIXME: Should we be expanding macros here? My guess is no.
  SourceLocation UnusedLoc = UnusedTok.getLocation();

  // Lex the left '('.
  Token Tok;
  PP.Lex(Tok);
  if (Tok.isNot(tok::l_paren)) {
    PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_lparen) << "unused";
    return;
  }
  SourceLocation LParenLoc = Tok.getLocation();

  // Lex the declaration reference(s).
  llvm::SmallVector<Token, 5> Identifiers;
  SourceLocation RParenLoc;
  bool LexID = true;

  while (true) {
    PP.Lex(Tok);

    if (LexID) {
      if (Tok.is(tok::identifier)) {
        Identifiers.push_back(Tok);
        LexID = false;
        continue;
      }

      // Illegal token!
      PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_var);
      return;
    }

    // We are execting a ')' or a ','.
    if (Tok.is(tok::comma)) {
      LexID = true;
      continue;
    }

    if (Tok.is(tok::r_paren)) {
      RParenLoc = Tok.getLocation();
      break;
    }

    // Illegal token!
    PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_punc);
    return;
  }

  PP.Lex(Tok);
  if (Tok.isNot(tok::eom)) {
    PP.Diag(Tok.getLocation(), diag::warn_pragma_extra_tokens_at_eol) <<
        "unused";
    return;
  }

  // Verify that we have a location for the right parenthesis.
  assert(RParenLoc.isValid() && "Valid '#pragma unused' must have ')'");
  assert(!Identifiers.empty() && "Valid '#pragma unused' must have arguments");

  // Perform the action to handle the pragma.
  Actions.ActOnPragmaUnused(Identifiers.data(), Identifiers.size(),
                            parser.CurScope, UnusedLoc, LParenLoc, RParenLoc);
}

 void out(const SourceLocation &loc)
 {
     if (!loc.isValid())
         return;
     out(toString(loc), loc);
 }

bool SanitizerBlacklist::isBlacklistedLocation(SourceLocation Loc,
                                               StringRef Category) const {
  return Loc.isValid() &&
         isBlacklistedFile(SM.getFilename(SM.getFileLoc(Loc)), Category);
}

/// \brief Parse a header declaration.
///
///   header-declaration:
///     'umbrella'[opt] 'header' string-literal
void ModuleMapParser::parseHeaderDecl(SourceLocation UmbrellaLoc) {
  assert(Tok.is(MMToken::HeaderKeyword));
  consumeToken();

  bool Umbrella = UmbrellaLoc.isValid();
  
  // Parse the header name.
  if (!Tok.is(MMToken::StringLiteral)) {
    Diags.Report(Tok.getLocation(), diag::err_mmap_expected_header) 
      << "header";
    HadError = true;
    return;
  }
  std::string FileName = Tok.getString();
  SourceLocation FileNameLoc = consumeToken();
  
  // Check whether we already have an umbrella.
  if (Umbrella && ActiveModule->Umbrella) {
    Diags.Report(FileNameLoc, diag::err_mmap_umbrella_clash)
      << ActiveModule->getFullModuleName();
    HadError = true;
    return;
  }

  // Look for this file.
  const FileEntry *File = 0;
  const FileEntry *BuiltinFile = 0;
  SmallString<128> PathName;
  if (llvm::sys::path::is_absolute(FileName)) {
    PathName = FileName;
    File = SourceMgr.getFileManager().getFile(PathName);
  } else if (const DirectoryEntry *Dir = getOverriddenHeaderSearchDir()) {
    PathName = Dir->getName();
    llvm::sys::path::append(PathName, FileName);
    File = SourceMgr.getFileManager().getFile(PathName);
  } else {
    // Search for the header file within the search directory.
    PathName = Directory->getName();
    unsigned PathLength = PathName.size();
    
    if (ActiveModule->isPartOfFramework()) {
      appendSubframeworkPaths(ActiveModule, PathName);
      
      // Check whether this file is in the public headers.
      llvm::sys::path::append(PathName, "Headers");
      llvm::sys::path::append(PathName, FileName);
      File = SourceMgr.getFileManager().getFile(PathName);
      
      if (!File) {
        // Check whether this file is in the private headers.
        PathName.resize(PathLength);
        llvm::sys::path::append(PathName, "PrivateHeaders");
        llvm::sys::path::append(PathName, FileName);
        File = SourceMgr.getFileManager().getFile(PathName);
      }
    } else {
      // Lookup for normal headers.
      llvm::sys::path::append(PathName, FileName);
      File = SourceMgr.getFileManager().getFile(PathName);
      
      // If this is a system module with a top-level header, this header
      // may have a counterpart (or replacement) in the set of headers
      // supplied by Clang. Find that builtin header.
      if (ActiveModule->IsSystem && !Umbrella && BuiltinIncludeDir &&
          BuiltinIncludeDir != Directory && isBuiltinHeader(FileName)) {
        SmallString<128> BuiltinPathName(BuiltinIncludeDir->getName());
        llvm::sys::path::append(BuiltinPathName, FileName);
        BuiltinFile = SourceMgr.getFileManager().getFile(BuiltinPathName);
        
        // If Clang supplies this header but the underlying system does not,
        // just silently swap in our builtin version. Otherwise, we'll end
        // up adding both (later).
        if (!File && BuiltinFile) {
          File = BuiltinFile;
          BuiltinFile = 0;
        }
      }
    }
  }
  
  // FIXME: We shouldn't be eagerly stat'ing every file named in a module map.
  // Come up with a lazy way to do this.
  if (File) {
    if (const Module *OwningModule = Map.Headers[File]) {
      Diags.Report(FileNameLoc, diag::err_mmap_header_conflict)
        << FileName << OwningModule->getFullModuleName();
      HadError = true;
    } else if (Umbrella) {
      const DirectoryEntry *UmbrellaDir = File->getDir();
      if ((OwningModule = Map.UmbrellaDirs[UmbrellaDir])) {
        Diags.Report(UmbrellaLoc, diag::err_mmap_umbrella_clash)
          << OwningModule->getFullModuleName();
        HadError = true;
      } else {
        // Record this umbrella header.
        Map.setUmbrellaHeader(ActiveModule, File);
//.........这里部分代码省略.........

static enum CXChildVisitResult findFileIdRefVisit(CXCursor cursor,
                                                  CXCursor parent,
                                                  CXClientData client_data) {
  CXCursor declCursor = clang_getCursorReferenced(cursor);
  if (!clang_isDeclaration(declCursor.kind))
    return CXChildVisit_Recurse;

  const Decl *D = cxcursor::getCursorDecl(declCursor);
  if (!D)
    return CXChildVisit_Continue;

  FindFileIdRefVisitData *data = (FindFileIdRefVisitData *)client_data;
  if (data->isHit(D)) {
    cursor = cxcursor::getSelectorIdentifierCursor(data->SelectorIdIdx, cursor);

    // We are looking for identifiers to highlight so for objc methods (and
    // not a parameter) we can only highlight the selector identifiers.
    if ((cursor.kind == CXCursor_ObjCClassMethodDecl ||
         cursor.kind == CXCursor_ObjCInstanceMethodDecl) &&
         cxcursor::getSelectorIdentifierIndex(cursor) == -1)
      return CXChildVisit_Recurse;

    if (clang_isExpression(cursor.kind)) {
      if (cursor.kind == CXCursor_DeclRefExpr ||
          cursor.kind == CXCursor_MemberRefExpr) {
        // continue..

      } else if (cursor.kind == CXCursor_ObjCMessageExpr &&
                 cxcursor::getSelectorIdentifierIndex(cursor) != -1) {
        // continue..
                
      } else
        return CXChildVisit_Recurse;
    }

    SourceLocation
      Loc = cxloc::translateSourceLocation(clang_getCursorLocation(cursor));
    SourceLocation SelIdLoc = cxcursor::getSelectorIdentifierLoc(cursor);
    if (SelIdLoc.isValid())
      Loc = SelIdLoc;

    ASTContext &Ctx = data->getASTContext();
    SourceManager &SM = Ctx.getSourceManager();
    bool isInMacroDef = false;
    if (Loc.isMacroID()) {
      bool isMacroArg;
      Loc = getFileSpellingLoc(SM, Loc, isMacroArg);
      isInMacroDef = !isMacroArg;
    }

    // We are looking for identifiers in a specific file.
    std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
    if (LocInfo.first != data->FID)
      return CXChildVisit_Recurse;

    if (isInMacroDef) {
      // FIXME: For a macro definition make sure that all expansions
      // of it expand to the same reference before allowing to point to it.
      return CXChildVisit_Recurse;
    }

    if (data->visitor.visit(data->visitor.context, cursor,
                        cxloc::translateSourceRange(Ctx, Loc)) == CXVisit_Break)
      return CXChildVisit_Break;
  }
  return CXChildVisit_Recurse;
}

/// CheckExceptionSpecSubset - Check whether the second function type's
/// exception specification is a subset (or equivalent) of the first function
/// type. This is used by override and pointer assignment checks.
bool Sema::CheckExceptionSpecSubset(
    const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
    const FunctionProtoType *Superset, SourceLocation SuperLoc,
    const FunctionProtoType *Subset, SourceLocation SubLoc) {

  // Just auto-succeed under -fno-exceptions.
  if (!getLangOptions().Exceptions)
    return false;

  // FIXME: As usual, we could be more specific in our error messages, but
  // that better waits until we've got types with source locations.

  if (!SubLoc.isValid())
    SubLoc = SuperLoc;

  // If superset contains everything, we're done.
  if (!Superset->hasExceptionSpec() || Superset->hasAnyExceptionSpec())
    return CheckParamExceptionSpec(NoteID, Superset, SuperLoc, Subset, SubLoc);

  // It does not. If the subset contains everything, we've failed.
  if (!Subset->hasExceptionSpec() || Subset->hasAnyExceptionSpec()) {
    Diag(SubLoc, DiagID);
    if (NoteID.getDiagID() != 0)
      Diag(SuperLoc, NoteID);
    return true;
  }

  // Neither contains everything. Do a proper comparison.
  for (FunctionProtoType::exception_iterator SubI = Subset->exception_begin(),
       SubE = Subset->exception_end(); SubI != SubE; ++SubI) {
    // Take one type from the subset.
    QualType CanonicalSubT = Context.getCanonicalType(*SubI);
    // Unwrap pointers and references so that we can do checks within a class
    // hierarchy. Don't unwrap member pointers; they don't have hierarchy
    // conversions on the pointee.
    bool SubIsPointer = false;
    if (const ReferenceType *RefTy = CanonicalSubT->getAs<ReferenceType>())
      CanonicalSubT = RefTy->getPointeeType();
    if (const PointerType *PtrTy = CanonicalSubT->getAs<PointerType>()) {
      CanonicalSubT = PtrTy->getPointeeType();
      SubIsPointer = true;
    }
    bool SubIsClass = CanonicalSubT->isRecordType();
    CanonicalSubT = CanonicalSubT.getLocalUnqualifiedType();

    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                       /*DetectVirtual=*/false);

    bool Contained = false;
    // Make sure it's in the superset.
    for (FunctionProtoType::exception_iterator SuperI =
           Superset->exception_begin(), SuperE = Superset->exception_end();
         SuperI != SuperE; ++SuperI) {
      QualType CanonicalSuperT = Context.getCanonicalType(*SuperI);
      // SubT must be SuperT or derived from it, or pointer or reference to
      // such types.
      if (const ReferenceType *RefTy = CanonicalSuperT->getAs<ReferenceType>())
        CanonicalSuperT = RefTy->getPointeeType();
      if (SubIsPointer) {
        if (const PointerType *PtrTy = CanonicalSuperT->getAs<PointerType>())
          CanonicalSuperT = PtrTy->getPointeeType();
        else {
          continue;
        }
      }
      CanonicalSuperT = CanonicalSuperT.getLocalUnqualifiedType();
      // If the types are the same, move on to the next type in the subset.
      if (CanonicalSubT == CanonicalSuperT) {
        Contained = true;
        break;
      }

      // Otherwise we need to check the inheritance.
      if (!SubIsClass || !CanonicalSuperT->isRecordType())
        continue;

      Paths.clear();
      if (!IsDerivedFrom(CanonicalSubT, CanonicalSuperT, Paths))
        continue;

      if (Paths.isAmbiguous(Context.getCanonicalType(CanonicalSuperT)))
        continue;

      // Do this check from a context without privileges.
      switch (CheckBaseClassAccess(SourceLocation(),
                                   CanonicalSuperT, CanonicalSubT,
                                   Paths.front(),
                                   /*Diagnostic*/ 0,
                                   /*ForceCheck*/ true,
                                   /*ForceUnprivileged*/ true)) {
      case AR_accessible: break;
      case AR_inaccessible: continue;
      case AR_dependent:
        llvm_unreachable("access check dependent for unprivileged context");
        break;
      case AR_delayed:
        llvm_unreachable("access check delayed in non-declaration");
//.........这里部分代码省略.........

void UseOverride::check(const MatchFinder::MatchResult &Result) {
  const FunctionDecl *Method = Result.Nodes.getStmtAs<FunctionDecl>("method");
  const SourceManager &Sources = *Result.SourceManager;

  assert(Method != nullptr);
  if (Method->getInstantiatedFromMemberFunction() != nullptr)
    Method = Method->getInstantiatedFromMemberFunction();

  if (Method->isImplicit() || Method->getLocation().isMacroID() ||
      Method->isOutOfLine())
    return;

  bool HasVirtual = Method->isVirtualAsWritten();
  bool HasOverride = Method->getAttr<OverrideAttr>();
  bool HasFinal = Method->getAttr<FinalAttr>();

  bool OnlyVirtualSpecified = HasVirtual && !HasOverride && !HasFinal;
  unsigned KeywordCount = HasVirtual + HasOverride + HasFinal;

  if (!OnlyVirtualSpecified && KeywordCount == 1)
    return; // Nothing to do.

  DiagnosticBuilder Diag = diag(
      Method->getLocation(),
      OnlyVirtualSpecified
          ? "Prefer using 'override' or 'final' instead of 'virtual'"
          : "Use exactly one of 'virtual', 'override' or (rarely) 'final'");

  CharSourceRange FileRange = Lexer::makeFileCharRange(
      CharSourceRange::getTokenRange(Method->getSourceRange()), Sources,
      Result.Context->getLangOpts());

  if (!FileRange.isValid())
    return;

  // FIXME: Instead of re-lexing and looking for specific macros such as
  // 'ABSTRACT', properly store the location of 'virtual' and '= 0' in each
  // FunctionDecl.
  SmallVector<Token, 16> Tokens = ParseTokens(FileRange, Sources,
                                              Result.Context->getLangOpts());

  // Add 'override' on inline declarations that don't already have it.
  if (!HasFinal && !HasOverride) {
    SourceLocation InsertLoc;
    StringRef ReplacementText = "override ";

    if (Method->hasAttrs()) {
      for (const clang::Attr *A : Method->getAttrs()) {
        if (!A->isImplicit()) {
          InsertLoc = Sources.getExpansionLoc(A->getLocation());
          break;
        }
      }
    }

    if (InsertLoc.isInvalid() && Method->doesThisDeclarationHaveABody() &&
        Method->getBody() && !Method->isDefaulted())
      InsertLoc = Method->getBody()->getLocStart();

    if (!InsertLoc.isValid()) {
      if (Tokens.size() > 2 && GetText(Tokens.back(), Sources) == "0" &&
          GetText(Tokens[Tokens.size() - 2], Sources) == "=") {
        InsertLoc = Tokens[Tokens.size() - 2].getLocation();
      } else if (GetText(Tokens.back(), Sources) == "ABSTRACT") {
        InsertLoc = Tokens.back().getLocation();
      }
    }

    if (!InsertLoc.isValid()) {
      InsertLoc = FileRange.getEnd();
      ReplacementText = " override";
    }
    Diag << FixItHint::CreateInsertion(InsertLoc, ReplacementText);
  }

  if (HasFinal && HasOverride) {
    SourceLocation OverrideLoc = Method->getAttr<OverrideAttr>()->getLocation();
    Diag << FixItHint::CreateRemoval(
        CharSourceRange::getTokenRange(OverrideLoc, OverrideLoc));
  }

  if (Method->isVirtualAsWritten()) {
    for (Token Tok : Tokens) {
      if (Tok.is(tok::raw_identifier) && GetText(Tok, Sources) == "virtual") {
        Diag << FixItHint::CreateRemoval(CharSourceRange::getTokenRange(
            Tok.getLocation(), Tok.getLocation()));
        break;
      }
    }
  }
}

/// EvaluateDefined - Process a 'defined(sym)' expression.
static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
                            bool ValueLive, Preprocessor &PP) {
  SourceLocation beginLoc(PeekTok.getLocation());
  Result.setBegin(beginLoc);

  // Get the next token, don't expand it.
  PP.LexUnexpandedNonComment(PeekTok);

  // Two options, it can either be a pp-identifier or a (.
  SourceLocation LParenLoc;
  if (PeekTok.is(tok::l_paren)) {
    // Found a paren, remember we saw it and skip it.
    LParenLoc = PeekTok.getLocation();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  if (PeekTok.is(tok::code_completion)) {
    if (PP.getCodeCompletionHandler())
      PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
    PP.setCodeCompletionReached();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  // If we don't have a pp-identifier now, this is an error.
  if (PP.CheckMacroName(PeekTok, MU_Other))
    return true;

  // Otherwise, we got an identifier, is it defined to something?
  IdentifierInfo *II = PeekTok.getIdentifierInfo();
  MacroDefinition Macro = PP.getMacroDefinition(II);
  Result.Val = !!Macro;
  Result.Val.setIsUnsigned(false); // Result is signed intmax_t.

  // If there is a macro, mark it used.
  if (Result.Val != 0 && ValueLive)
    PP.markMacroAsUsed(Macro.getMacroInfo());

  // Save macro token for callback.
  Token macroToken(PeekTok);

  // If we are in parens, ensure we have a trailing ).
  if (LParenLoc.isValid()) {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexUnexpandedNonComment(PeekTok);

    if (PeekTok.isNot(tok::r_paren)) {
      PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_after)
          << "'defined'" << tok::r_paren;
      PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
      return true;
    }
    // Consume the ).
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  } else {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  }

  // Invoke the 'defined' callback.
  if (PPCallbacks *Callbacks = PP.getPPCallbacks()) {
    Callbacks->Defined(macroToken, Macro,
                       SourceRange(beginLoc, PeekTok.getLocation()));
  }

  // Success, remember that we saw defined(X).
  DT.State = DefinedTracker::DefinedMacro;
  DT.TheMacro = II;
  return false;
}

// #pragma unused(identifier)
void PragmaUnusedHandler::HandlePragma(Preprocessor &PP, Token &UnusedTok) {
  // FIXME: Should we be expanding macros here? My guess is no.
  SourceLocation UnusedLoc = UnusedTok.getLocation();
  
  // Lex the left '('.
  Token Tok;
  PP.Lex(Tok);
  if (Tok.isNot(tok::l_paren)) {
    PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_lparen) << "unused";
    return;
  }
  SourceLocation LParenLoc = Tok.getLocation();
  
  // Lex the declaration reference(s).
  llvm::SmallVector<Action::ExprTy*, 5> Ex;
  SourceLocation RParenLoc;
  bool LexID = true;
  
  while (true) {
    PP.Lex(Tok);
    
    if (LexID) {
      if (Tok.is(tok::identifier)) {            
        Action::OwningExprResult Name = 
          Actions.ActOnIdentifierExpr(parser.CurScope, Tok.getLocation(),
                                      *Tok.getIdentifierInfo(), false);
      
        if (Name.isInvalid()) {
          if (!Ex.empty())
            Action::MultiExprArg Release(Actions, &Ex[0], Ex.size());
          return;
        }
        
        Ex.push_back(Name.release());        
        LexID = false;
        continue;
      }

      // Illegal token! Release the parsed expressions (if any) and emit
      // a warning.
      if (!Ex.empty())
        Action::MultiExprArg Release(Actions, &Ex[0], Ex.size());
      
      PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_var);
      return;
    }
    
    // We are execting a ')' or a ','.
    if (Tok.is(tok::comma)) {
      LexID = true;
      continue;
    }
    
    if (Tok.is(tok::r_paren)) {
      RParenLoc = Tok.getLocation();
      break;
    }
    
    // Illegal token! Release the parsed expressions (if any) and emit
    // a warning.
    if (!Ex.empty())
      Action::MultiExprArg Release(Actions, &Ex[0], Ex.size());
    
    PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_punc);
    return;
  }
  
  // Verify that we have a location for the right parenthesis.
  assert(RParenLoc.isValid() && "Valid '#pragma unused' must have ')'");
  assert(!Ex.empty() && "Valid '#pragma unused' must have arguments");

  // Perform the action to handle the pragma.    
  Actions.ActOnPragmaUnused(&Ex[0], Ex.size(), UnusedLoc, LParenLoc, RParenLoc);
}

/// EvaluateDefined - Process a 'defined(sym)' expression.
static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
                            bool ValueLive, Preprocessor &PP) {
  SourceLocation beginLoc(PeekTok.getLocation());
  Result.setBegin(beginLoc);

  // Get the next token, don't expand it.
  PP.LexUnexpandedNonComment(PeekTok);

  // Two options, it can either be a pp-identifier or a (.
  SourceLocation LParenLoc;
  if (PeekTok.is(tok::l_paren)) {
    // Found a paren, remember we saw it and skip it.
    LParenLoc = PeekTok.getLocation();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  if (PeekTok.is(tok::code_completion)) {
    if (PP.getCodeCompletionHandler())
      PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
    PP.setCodeCompletionReached();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  // If we don't have a pp-identifier now, this is an error.
  if (PP.CheckMacroName(PeekTok, MU_Other))
    return true;

  // Otherwise, we got an identifier, is it defined to something?
  IdentifierInfo *II = PeekTok.getIdentifierInfo();
  MacroDefinition Macro = PP.getMacroDefinition(II);
  Result.Val = !!Macro;
  Result.Val.setIsUnsigned(false); // Result is signed intmax_t.

  // If there is a macro, mark it used.
  if (Result.Val != 0 && ValueLive)
    PP.markMacroAsUsed(Macro.getMacroInfo());

  // Save macro token for callback.
  Token macroToken(PeekTok);

  // If we are in parens, ensure we have a trailing ).
  if (LParenLoc.isValid()) {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexUnexpandedNonComment(PeekTok);

    if (PeekTok.isNot(tok::r_paren)) {
      PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_after)
          << "'defined'" << tok::r_paren;
      PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
      return true;
    }
    // Consume the ).
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  } else {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  }

  // [cpp.cond]p4:
  //   Prior to evaluation, macro invocations in the list of preprocessing
  //   tokens that will become the controlling constant expression are replaced
  //   (except for those macro names modified by the 'defined' unary operator),
  //   just as in normal text. If the token 'defined' is generated as a result
  //   of this replacement process or use of the 'defined' unary operator does
  //   not match one of the two specified forms prior to macro replacement, the
  //   behavior is undefined.
  // This isn't an idle threat, consider this program:
  //   #define FOO
  //   #define BAR defined(FOO)
  //   #if BAR
  //   ...
  //   #else
  //   ...
  //   #endif
  // clang and gcc will pick the #if branch while Visual Studio will take the
  // #else branch.  Emit a warning about this undefined behavior.
  if (beginLoc.isMacroID()) {
    bool IsFunctionTypeMacro =
        PP.getSourceManager()
            .getSLocEntry(PP.getSourceManager().getFileID(beginLoc))
            .getExpansion()
            .isFunctionMacroExpansion();
    // For object-type macros, it's easy to replace
    //   #define FOO defined(BAR)
    // with
    //   #if defined(BAR)
    //   #define FOO 1
    //   #else
    //   #define FOO 0
    //   #endif
    // and doing so makes sense since compilers handle this differently in
    // practice (see example further up).  But for function-type macros,
    // there is no good way to write
    //   # define FOO(x) (defined(M_ ## x) && M_ ## x)
    // in a different way, and compilers seem to agree on how to behave here.
    // So warn by default on object-type macros, but only warn in -pedantic
//.........这里部分代码省略.........

//.........这里部分代码省略.........
            else
              m_Sema->Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
            m_Sema->Diag(PrevTagDecl->getLocation(), diag::note_previous_use);

            if (SafeToContinue)
              Kind = PrevTagDecl->getTagKind();
            else {
              // Recover by making this an anonymous redefinition.
              Name = 0;
              Previous.clear();
              Invalid = true;
            }
          }

          if (Kind == TTK_Enum && PrevTagDecl->getTagKind() == TTK_Enum) {
            const EnumDecl *NewEnum = cast<EnumDecl>(NewTD);
            const EnumDecl *PrevEnum = cast<EnumDecl>(PrevTagDecl);

            // All conflicts with previous declarations are recovered by
            // returning the previous declaration.
            if (NewEnum->isScoped() != PrevEnum->isScoped()) {
              m_Sema->Diag(KWLoc, diag::err_enum_redeclare_scoped_mismatch)
                << PrevEnum->isScoped();
              m_Sema->Diag(PrevTagDecl->getLocation(), diag::note_previous_use);

              NewTD->setInvalidDecl();
              return false;
            }
            else if (PrevEnum->isFixed()) {
              QualType T = NewEnum->getIntegerType();

              if (!m_Context->hasSameUnqualifiedType(T,
                                                  PrevEnum->getIntegerType())) {
                m_Sema->Diag(NameLoc.isValid() ? NameLoc : KWLoc,
                             diag::err_enum_redeclare_type_mismatch)
                  << T
                  << PrevEnum->getIntegerType();
                m_Sema->Diag(PrevTagDecl->getLocation(),
                             diag::note_previous_use);

                NewTD->setInvalidDecl();
                return false;
              }
            }
            else if (NewEnum->isFixed() != PrevEnum->isFixed()) {
              m_Sema->Diag(KWLoc, diag::err_enum_redeclare_fixed_mismatch)
                << PrevEnum->isFixed();
              m_Sema->Diag(PrevTagDecl->getLocation(), diag::note_previous_use);

              NewTD->setInvalidDecl();
              return false;
            }
          }

          if (!Invalid) {
            // If this is a use, just return the declaration we found.

            // Diagnose attempts to redefine a tag.
            if (NewTD->isThisDeclarationADefinition()) {
              if (TagDecl* Def = PrevTagDecl->getDefinition()) {
                // If we're defining a specialization and the previous
                // definition is from an implicit instantiation, don't emit an
                // error here; we'll catch this in the general case below.
                if (!isExplicitSpecialization ||
                    !isa<CXXRecordDecl>(Def) ||
                    cast<CXXRecordDecl>(Def)->getTemplateSpecializationKind()

/// \brief Parse a C++ template template argument.
ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
  if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
      !Tok.is(tok::annot_cxxscope))
    return ParsedTemplateArgument();

  // C++0x [temp.arg.template]p1:
  //   A template-argument for a template template-parameter shall be the name
  //   of a class template or an alias template, expressed as id-expression.
  //   
  // We parse an id-expression that refers to a class template or alias
  // template. The grammar we parse is:
  //
  //   nested-name-specifier[opt] template[opt] identifier ...[opt]
  //
  // followed by a token that terminates a template argument, such as ',', 
  // '>', or (in some cases) '>>'.
  CXXScopeSpec SS; // nested-name-specifier, if present
  ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
                                 /*EnteringContext=*/false);
  
  ParsedTemplateArgument Result;
  SourceLocation EllipsisLoc;
  if (SS.isSet() && Tok.is(tok::kw_template)) {
    // Parse the optional 'template' keyword following the 
    // nested-name-specifier.
    SourceLocation TemplateKWLoc = ConsumeToken();
    
    if (Tok.is(tok::identifier)) {
      // We appear to have a dependent template name.
      UnqualifiedId Name;
      Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
      ConsumeToken(); // the identifier
      
      // Parse the ellipsis.
      if (Tok.is(tok::ellipsis))
        EllipsisLoc = ConsumeToken();
      
      // If the next token signals the end of a template argument,
      // then we have a dependent template name that could be a template
      // template argument.
      TemplateTy Template;
      if (isEndOfTemplateArgument(Tok) &&
          Actions.ActOnDependentTemplateName(getCurScope(),
                                             SS, TemplateKWLoc, Name,
                                             /*ObjectType=*/ ParsedType(),
                                             /*EnteringContext=*/false,
                                             Template))
        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
    }
  } else if (Tok.is(tok::identifier)) {
    // We may have a (non-dependent) template name.
    TemplateTy Template;
    UnqualifiedId Name;
    Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
    ConsumeToken(); // the identifier
    
    // Parse the ellipsis.
    if (Tok.is(tok::ellipsis))
      EllipsisLoc = ConsumeToken();

    if (isEndOfTemplateArgument(Tok)) {
      bool MemberOfUnknownSpecialization;
      TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
                                               /*hasTemplateKeyword=*/false,
                                                    Name,
                                               /*ObjectType=*/ ParsedType(), 
                                                    /*EnteringContext=*/false, 
                                                    Template,
                                                MemberOfUnknownSpecialization);
      if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
        // We have an id-expression that refers to a class template or
        // (C++0x) alias template. 
        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
      }
    }
  }
  
  // If this is a pack expansion, build it as such.
  if (EllipsisLoc.isValid() && !Result.isInvalid())
    Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
  
  return Result;
}

// #pragma unused(identifier)
void PragmaUnusedHandler::HandlePragma(Preprocessor &PP, 
                                       PragmaIntroducerKind Introducer,
                                       Token &UnusedTok) {
  // FIXME: Should we be expanding macros here? My guess is no.
  SourceLocation UnusedLoc = UnusedTok.getLocation();

  // Lex the left '('.
  Token Tok;
  PP.Lex(Tok);
  if (Tok.isNot(tok::l_paren)) {
    PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_lparen) << "unused";
    return;
  }

  // Lex the declaration reference(s).
  SmallVector<Token, 5> Identifiers;
  SourceLocation RParenLoc;
  bool LexID = true;

  while (true) {
    PP.Lex(Tok);

    if (LexID) {
      if (Tok.is(tok::identifier)) {
        Identifiers.push_back(Tok);
        LexID = false;
        continue;
      }

      // Illegal token!
      PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_var);
      return;
    }

    // We are execting a ')' or a ','.
    if (Tok.is(tok::comma)) {
      LexID = true;
      continue;
    }

    if (Tok.is(tok::r_paren)) {
      RParenLoc = Tok.getLocation();
      break;
    }

    // Illegal token!
    PP.Diag(Tok.getLocation(), diag::warn_pragma_unused_expected_punc);
    return;
  }

  PP.Lex(Tok);
  if (Tok.isNot(tok::eod)) {
    PP.Diag(Tok.getLocation(), diag::warn_pragma_extra_tokens_at_eol) <<
        "unused";
    return;
  }

  // Verify that we have a location for the right parenthesis.
  assert(RParenLoc.isValid() && "Valid '#pragma unused' must have ')'");
  assert(!Identifiers.empty() && "Valid '#pragma unused' must have arguments");

  // For each identifier token, insert into the token stream a
  // annot_pragma_unused token followed by the identifier token.
  // This allows us to cache a "#pragma unused" that occurs inside an inline
  // C++ member function.

  Token *Toks = new Token[2*Identifiers.size()];
  for (unsigned i=0; i != Identifiers.size(); i++) {
    Token &pragmaUnusedTok = Toks[2*i], &idTok = Toks[2*i+1];
    pragmaUnusedTok.startToken();
    pragmaUnusedTok.setKind(tok::annot_pragma_unused);
    pragmaUnusedTok.setLocation(UnusedLoc);
    idTok = Identifiers[i];
  }
  PP.EnterTokenStream(Toks, 2*Identifiers.size(), /*DisableMacroExpansion=*/true, /*OwnsTokens=*/true);
}