C++ SmallVector::swap方法代码示例

ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, 
                                 Scope *CurScope, 
                                 bool IsInstantiation) {
  // Collect information from the lambda scope.
  SmallVector<LambdaExpr::Capture, 4> Captures;
  SmallVector<Expr *, 4> CaptureInits;
  LambdaCaptureDefault CaptureDefault;
  CXXRecordDecl *Class;
  CXXMethodDecl *CallOperator;
  SourceRange IntroducerRange;
  bool ExplicitParams;
  bool ExplicitResultType;
  bool LambdaExprNeedsCleanups;
  bool ContainsUnexpandedParameterPack;
  SmallVector<VarDecl *, 4> ArrayIndexVars;
  SmallVector<unsigned, 4> ArrayIndexStarts;
  {
    LambdaScopeInfo *LSI = getCurLambda();
    CallOperator = LSI->CallOperator;
    Class = LSI->Lambda;
    IntroducerRange = LSI->IntroducerRange;
    ExplicitParams = LSI->ExplicitParams;
    ExplicitResultType = !LSI->HasImplicitReturnType;
    LambdaExprNeedsCleanups = LSI->ExprNeedsCleanups;
    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
    ArrayIndexVars.swap(LSI->ArrayIndexVars);
    ArrayIndexStarts.swap(LSI->ArrayIndexStarts);
    
    // Translate captures.
    for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) {
      LambdaScopeInfo::Capture From = LSI->Captures[I];
      assert(!From.isBlockCapture() && "Cannot capture __block variables");
      bool IsImplicit = I >= LSI->NumExplicitCaptures;

      // Handle 'this' capture.
      if (From.isThisCapture()) {
        Captures.push_back(LambdaExpr::Capture(From.getLocation(),
                                               IsImplicit,
                                               LCK_This));
        CaptureInits.push_back(new (Context) CXXThisExpr(From.getLocation(),
                                                         getCurrentThisType(),
                                                         /*isImplicit=*/true));
        continue;
      }

      VarDecl *Var = From.getVariable();
      LambdaCaptureKind Kind = From.isCopyCapture()? LCK_ByCopy : LCK_ByRef;
      Captures.push_back(LambdaExpr::Capture(From.getLocation(), IsImplicit, 
                                             Kind, Var, From.getEllipsisLoc()));
      CaptureInits.push_back(From.getCopyExpr());
    }

    switch (LSI->ImpCaptureStyle) {
    case CapturingScopeInfo::ImpCap_None:
      CaptureDefault = LCD_None;
      break;

    case CapturingScopeInfo::ImpCap_LambdaByval:
      CaptureDefault = LCD_ByCopy;
      break;

    case CapturingScopeInfo::ImpCap_CapturedRegion:
    case CapturingScopeInfo::ImpCap_LambdaByref:
      CaptureDefault = LCD_ByRef;
      break;

    case CapturingScopeInfo::ImpCap_Block:
      llvm_unreachable("block capture in lambda");
      break;
    }

    // C++11 [expr.prim.lambda]p4:
    //   If a lambda-expression does not include a
    //   trailing-return-type, it is as if the trailing-return-type
    //   denotes the following type:
    // FIXME: Assumes current resolution to core issue 975.
    if (LSI->HasImplicitReturnType) {
      deduceClosureReturnType(*LSI);

      //   - if there are no return statements in the
      //     compound-statement, or all return statements return
      //     either an expression of type void or no expression or
      //     braced-init-list, the type void;
      if (LSI->ReturnType.isNull()) {
        LSI->ReturnType = Context.VoidTy;
      }

      // Create a function type with the inferred return type.
      const FunctionProtoType *Proto
        = CallOperator->getType()->getAs<FunctionProtoType>();
      QualType FunctionTy
        = Context.getFunctionType(LSI->ReturnType,
                                  ArrayRef<QualType>(Proto->arg_type_begin(),
                                                     Proto->getNumArgs()),
                                  Proto->getExtProtoInfo());
      CallOperator->setType(FunctionTy);
    }

    // C++ [expr.prim.lambda]p7:
    //   The lambda-expression's compound-statement yields the
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    // Emit the diagnostic at the macro name in case there is a missing ).
    // Emitting it at the , could be far away from the macro name.
    Diag(TooManyArgsLoc, diag::err_too_many_args_in_macro_invoc);
    Diag(MI->getDefinitionLoc(), diag::note_macro_here)
      << MacroName.getIdentifierInfo();

    // Commas from braced initializer lists will be treated as argument
    // separators inside macros.  Attempt to correct for this with parentheses.
    // TODO: See if this can be generalized to angle brackets for templates
    // inside macro arguments.

    SmallVector<Token, 4> FixedArgTokens;
    unsigned FixedNumArgs = 0;
    SmallVector<SourceRange, 4> ParenHints, InitLists;
    if (!GenerateNewArgTokens(*this, ArgTokens, FixedArgTokens, FixedNumArgs,
                              ParenHints, InitLists)) {
      if (!InitLists.empty()) {
        DiagnosticBuilder DB =
            Diag(MacroName,
                 diag::note_init_list_at_beginning_of_macro_argument);
        for (SourceRange Range : InitLists)
          DB << Range;
      }
      return nullptr;
    }
    if (FixedNumArgs != MinArgsExpected)
      return nullptr;

    DiagnosticBuilder DB = Diag(MacroName, diag::note_suggest_parens_for_macro);
    for (SourceRange ParenLocation : ParenHints) {
      DB << FixItHint::CreateInsertion(ParenLocation.getBegin(), "(");
      DB << FixItHint::CreateInsertion(ParenLocation.getEnd(), ")");
    }
    ArgTokens.swap(FixedArgTokens);
    NumActuals = FixedNumArgs;
  }

  // See MacroArgs instance var for description of this.
  bool isVarargsElided = false;


  if (NumActuals < MinArgsExpected) {
    // There are several cases where too few arguments is ok, handle them now.
    if (NumActuals == 0 && MinArgsExpected == 1) {
      // #define A(X)  or  #define A(...)   ---> A()

      // If there is exactly one argument, and that argument is missing,
      // then we have an empty "()" argument empty list.  This is fine, even if
      // the macro expects one argument (the argument is just empty).
      isVarargsElided = MI->isVariadic();
    } else if ((FoundElidedComma || MI->isVariadic()) &&
               (NumActuals+1 == MinArgsExpected ||  // A(x, ...) -> A(X)
                (NumActuals == 0 && MinArgsExpected == 2))) {// A(x,...) -> A()
      // Varargs where the named vararg parameter is missing: OK as extension.
      //   #define A(x, ...)
      //   A("blah")
      //
      // If the macro contains the comma pasting extension, the diagnostic
      // is suppressed; we know we'll get another diagnostic later.
      if (!MI->hasCommaPasting()) {
        Diag(Tok, diag::ext_missing_varargs_arg);
        Diag(MI->getDefinitionLoc(), diag::note_macro_here)
          << MacroName.getIdentifierInfo();
      }

      // Remember this occurred, allowing us to elide the comma when used for