[llvm-branch-commits] [cfe-branch] r196470 - Merging r196454:

NAKAMURA Takumi geek4civic at gmail.com
Fri Dec 6 01:01:05 PST 2013


Bill, it requires merging r196459 to suppress warnings.

2013/12/5 Bill Wendling <isanbard at gmail.com>:
> Author: void
> Date: Wed Dec  4 23:25:04 2013
> New Revision: 196470
>
> URL: http://llvm.org/viewvc/llvm-project?rev=196470&view=rev
> Log:
> Merging r196454:
> ------------------------------------------------------------------------
> r196454 | faisalv | 2013-12-04 17:40:41 -0800 (Wed, 04 Dec 2013) | 43 lines
>
> Fix init-captures for generic lambdas.
>
> For an init capture, process the initialization expression
> right away.  For lambda init-captures such as the following:
> const int x = 10;
>  auto L = [i = x+1](int a) {
>    return [j = x+2,
>           &k = x](char b) { };
>  };
> keep in mind that each lambda init-capture has to have:
>  - its initialization expression executed in the context
>    of the enclosing/parent decl-context.
>  - but the variable itself has to be 'injected' into the
>    decl-context of its lambda's call-operator (which has
>    not yet been created).
> Each init-expression is a full-expression that has to get
> Sema-analyzed (for capturing etc.) before its lambda's
> call-operator's decl-context, scope & scopeinfo are pushed on their
> respective stacks.  Thus if any variable is odr-used in the init-capture
> it will correctly get captured in the enclosing lambda, if one exists.
> The init-variables above are created later once the lambdascope and
> call-operators decl-context is pushed onto its respective stack.
>
> Since the lambda init-capture's initializer expression occurs in the
> context of the enclosing function or lambda, therefore we can not wait
> till a lambda scope has been pushed on before deciding whether the
> variable needs to be captured.  We also need to process all
> lvalue-to-rvalue conversions and discarded-value conversions,
> so that we can avoid capturing certain constant variables.
> For e.g.,
>  void test() {
>   const int x = 10;
>   auto L = [&z = x](char a) { <-- don't capture by the current lambda
>     return [y = x](int i) { <-- don't capture by enclosing lambda
>          return y;
>     }
>   };
> If x was not const, the second use would require 'L' to capture, and
> that would be an error.
> Make sure TranformLambdaExpr is also aware of this.
>
> Patch approved by Richard (Thanks!!)
> http://llvm-reviews.chandlerc.com/D2092
> ------------------------------------------------------------------------
>
> Modified:
>     cfe/branches/release_34/   (props changed)
>     cfe/branches/release_34/include/clang/Sema/DeclSpec.h
>     cfe/branches/release_34/include/clang/Sema/Initialization.h
>     cfe/branches/release_34/include/clang/Sema/Sema.h
>     cfe/branches/release_34/lib/Parse/ParseExprCXX.cpp
>     cfe/branches/release_34/lib/Sema/SemaAccess.cpp
>     cfe/branches/release_34/lib/Sema/SemaExpr.cpp
>     cfe/branches/release_34/lib/Sema/SemaExprCXX.cpp
>     cfe/branches/release_34/lib/Sema/SemaInit.cpp
>     cfe/branches/release_34/lib/Sema/SemaLambda.cpp
>     cfe/branches/release_34/lib/Sema/SemaTemplateInstantiate.cpp
>     cfe/branches/release_34/lib/Sema/TreeTransform.h
>     cfe/branches/release_34/test/SemaCXX/cxx1y-init-captures.cpp
>
> Propchange: cfe/branches/release_34/
> ------------------------------------------------------------------------------
> --- svn:mergeinfo (original)
> +++ svn:mergeinfo Wed Dec  4 23:25:04 2013
> @@ -1,4 +1,4 @@
>  /cfe/branches/type-system-rewrite:134693-134817
> -/cfe/trunk:195126,195128,195135-195136,195146,195149,195154,195158,195163,195168,195174,195249,195268,195283,195303,195326,195329,195367,195384,195409,195420,195422,195501,195547,195556,195558,195587,195620,195635,195669,195687,195693,195710,195713,195716,195756,195760,195768,195777,195789,195792,195804,195827,195843-195844,195877,195887-195888,195897,195903,195905-195906,195932,195936-195943,195970,195983,196045,196048,196050,196058,196114-196115,196153,196206,196215,196370,196423
> +/cfe/trunk:195126,195128,195135-195136,195146,195149,195154,195158,195163,195168,195174,195249,195268,195283,195303,195326,195329,195367,195384,195409,195420,195422,195501,195547,195556,195558,195587,195620,195635,195669,195687,195693,195710,195713,195716,195756,195760,195768,195777,195789,195792,195804,195827,195843-195844,195877,195887-195888,195897,195903,195905-195906,195932,195936-195943,195970,195983,196045,196048,196050,196058,196114-196115,196153,196206,196215,196370,196423,196454
>  /cfe/trunk/test:170344
>  /cfe/trunk/test/SemaTemplate:126920
>
> Modified: cfe/branches/release_34/include/clang/Sema/DeclSpec.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/include/clang/Sema/DeclSpec.h?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/include/clang/Sema/DeclSpec.h (original)
> +++ cfe/branches/release_34/include/clang/Sema/DeclSpec.h Wed Dec  4 23:25:04 2013
> @@ -2166,12 +2166,13 @@ struct LambdaCapture {
>    IdentifierInfo *Id;
>    SourceLocation EllipsisLoc;
>    ExprResult Init;
> -
> +  ParsedType InitCaptureType;
>    LambdaCapture(LambdaCaptureKind Kind, SourceLocation Loc,
> -                IdentifierInfo* Id = 0,
> -                SourceLocation EllipsisLoc = SourceLocation(),
> -                ExprResult Init = ExprResult())
> -    : Kind(Kind), Loc(Loc), Id(Id), EllipsisLoc(EllipsisLoc), Init(Init)
> +                IdentifierInfo* Id,
> +                SourceLocation EllipsisLoc,
> +                ExprResult Init, ParsedType InitCaptureType)
> +    : Kind(Kind), Loc(Loc), Id(Id), EllipsisLoc(EllipsisLoc), Init(Init),
> +        InitCaptureType(InitCaptureType)
>    {}
>  };
>
> @@ -2188,10 +2189,12 @@ struct LambdaIntroducer {
>    /// \brief Append a capture in a lambda introducer.
>    void addCapture(LambdaCaptureKind Kind,
>                    SourceLocation Loc,
> -                  IdentifierInfo* Id = 0,
> -                  SourceLocation EllipsisLoc = SourceLocation(),
> -                  ExprResult Init = ExprResult()) {
> -    Captures.push_back(LambdaCapture(Kind, Loc, Id, EllipsisLoc, Init));
> +                  IdentifierInfo* Id,
> +                  SourceLocation EllipsisLoc,
> +                  ExprResult Init,
> +                  ParsedType InitCaptureType) {
> +    Captures.push_back(LambdaCapture(Kind, Loc, Id, EllipsisLoc, Init,
> +        InitCaptureType));
>    }
>  };
>
>
> Modified: cfe/branches/release_34/include/clang/Sema/Initialization.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/include/clang/Sema/Initialization.h?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/include/clang/Sema/Initialization.h (original)
> +++ cfe/branches/release_34/include/clang/Sema/Initialization.h Wed Dec  4 23:25:04 2013
> @@ -116,8 +116,8 @@ private:
>    };
>
>    struct C {
> -    /// \brief The variable being captured by an EK_LambdaCapture.
> -    VarDecl *Var;
> +    /// \brief The name of the variable being captured by an EK_LambdaCapture.
> +    IdentifierInfo *VarID;
>
>      /// \brief The source location at which the capture occurs.
>      unsigned Location;
> @@ -183,10 +183,10 @@ private:
>                      const InitializedEntity &Parent);
>
>    /// \brief Create the initialization entity for a lambda capture.
> -  InitializedEntity(VarDecl *Var, FieldDecl *Field, SourceLocation Loc)
> -    : Kind(EK_LambdaCapture), Parent(0), Type(Field->getType())
> +  InitializedEntity(IdentifierInfo *VarID, QualType FieldType, SourceLocation Loc)
> +    : Kind(EK_LambdaCapture), Parent(0), Type(FieldType)
>    {
> -    Capture.Var = Var;
> +    Capture.VarID = VarID;
>      Capture.Location = Loc.getRawEncoding();
>    }
>
> @@ -309,10 +309,10 @@ public:
>    }
>
>    /// \brief Create the initialization entity for a lambda capture.
> -  static InitializedEntity InitializeLambdaCapture(VarDecl *Var,
> -                                                   FieldDecl *Field,
> +  static InitializedEntity InitializeLambdaCapture(IdentifierInfo *VarID,
> +                                                   QualType FieldType,
>                                                     SourceLocation Loc) {
> -    return InitializedEntity(Var, Field, Loc);
> +    return InitializedEntity(VarID, FieldType, Loc);
>    }
>
>    /// \brief Create the entity for a compound literal initializer.
> @@ -402,13 +402,11 @@ public:
>             getKind() == EK_ComplexElement);
>      this->Index = Index;
>    }
> -
> -  /// \brief Retrieve the variable for a captured variable in a lambda.
> -  VarDecl *getCapturedVar() const {
> +  /// \brief For a lambda capture, return the capture's name.
> +  StringRef getCapturedVarName() const {
>      assert(getKind() == EK_LambdaCapture && "Not a lambda capture!");
> -    return Capture.Var;
> +    return Capture.VarID->getName();
>    }
> -
>    /// \brief Determine the location of the capture when initializing
>    /// field from a captured variable in a lambda.
>    SourceLocation getCaptureLoc() const {
>
> Modified: cfe/branches/release_34/include/clang/Sema/Sema.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/include/clang/Sema/Sema.h?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/include/clang/Sema/Sema.h (original)
> +++ cfe/branches/release_34/include/clang/Sema/Sema.h Wed Dec  4 23:25:04 2013
> @@ -281,6 +281,12 @@ public:
>    /// element type here is ExprWithCleanups::Object.
>    SmallVector<BlockDecl*, 8> ExprCleanupObjects;
>
> +  /// \brief Store a list of either DeclRefExprs or MemberExprs
> +  ///  that contain a reference to a variable (constant) that may or may not
> +  ///  be odr-used in this Expr, and we won't know until all lvalue-to-rvalue
> +  ///  and discarded value conversions have been applied to all subexpressions
> +  ///  of the enclosing full expression.  This is cleared at the end of each
> +  ///  full expression.
>    llvm::SmallPtrSet<Expr*, 2> MaybeODRUseExprs;
>
>    /// \brief Stack containing information about each of the nested
> @@ -4311,7 +4317,8 @@ public:
>    }
>    ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,
>                                   bool DiscardedValue = false,
> -                                 bool IsConstexpr = false);
> +                                 bool IsConstexpr = false,
> +                                 bool IsLambdaInitCaptureInitializer = false);
>    StmtResult ActOnFinishFullStmt(Stmt *Stmt);
>
>    // Marks SS invalid if it represents an incomplete type.
> @@ -4506,10 +4513,18 @@ public:
>                          bool ExplicitResultType,
>                          bool Mutable);
>
> -  /// \brief Check an init-capture and build the implied variable declaration
> -  /// with the specified name and initializer.
> -  VarDecl *checkInitCapture(SourceLocation Loc, bool ByRef,
> -                            IdentifierInfo *Id, Expr *Init);
> +  /// \brief Perform initialization analysis of the init-capture and perform
> +  /// any implicit conversions such as an lvalue-to-rvalue conversion if
> +  /// not being used to initialize a reference.
> +  QualType performLambdaInitCaptureInitialization(SourceLocation Loc,
> +      bool ByRef, IdentifierInfo *Id, Expr *&Init);
> +  /// \brief Create a dummy variable within the declcontext of the lambda's
> +  ///  call operator, for name lookup purposes for a lambda init capture.
> +  ///
> +  ///  CodeGen handles emission of lambda captures, ignoring these dummy
> +  ///  variables appropriately.
> +  VarDecl *createLambdaInitCaptureVarDecl(SourceLocation Loc,
> +    QualType InitCaptureType, IdentifierInfo *Id, Expr *Init);
>
>    /// \brief Build the implicit field for an init-capture.
>    FieldDecl *buildInitCaptureField(sema::LambdaScopeInfo *LSI, VarDecl *Var);
>
> Modified: cfe/branches/release_34/lib/Parse/ParseExprCXX.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Parse/ParseExprCXX.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Parse/ParseExprCXX.cpp (original)
> +++ cfe/branches/release_34/lib/Parse/ParseExprCXX.cpp Wed Dec  4 23:25:04 2013
> @@ -633,8 +633,7 @@ ExprResult Parser::ParseCXXIdExpression(
>  ExprResult Parser::ParseLambdaExpression() {
>    // Parse lambda-introducer.
>    LambdaIntroducer Intro;
> -
> -  Optional<unsigned> DiagID(ParseLambdaIntroducer(Intro));
> +  Optional<unsigned> DiagID = ParseLambdaIntroducer(Intro);
>    if (DiagID) {
>      Diag(Tok, DiagID.getValue());
>      SkipUntil(tok::r_square, StopAtSemi);
> @@ -674,7 +673,7 @@ ExprResult Parser::TryParseLambdaExpress
>    if (Next.is(tok::identifier) && After.is(tok::identifier)) {
>      return ExprEmpty();
>    }
> -
> +
>    // Here, we're stuck: lambda introducers and Objective-C message sends are
>    // unambiguous, but it requires arbitrary lookhead.  [a,b,c,d,e,f,g] is a
>    // lambda, and [a,b,c,d,e,f,g h] is a Objective-C message send.  Instead of
> @@ -684,6 +683,7 @@ ExprResult Parser::TryParseLambdaExpress
>    LambdaIntroducer Intro;
>    if (TryParseLambdaIntroducer(Intro))
>      return ExprEmpty();
> +
>    return ParseLambdaExpressionAfterIntroducer(Intro);
>  }
>
> @@ -809,6 +809,11 @@ Optional<unsigned> Parser::ParseLambdaIn
>                                              Exprs);
>          }
>        } else if (Tok.is(tok::l_brace) || Tok.is(tok::equal)) {
> +        // Each lambda init-capture forms its own full expression, which clears
> +        // Actions.MaybeODRUseExprs. So create an expression evaluation context
> +        // to save the necessary state, and restore it later.
> +        EnterExpressionEvaluationContext EC(Actions,
> +                                            Sema::PotentiallyEvaluated);
>          if (Tok.is(tok::equal))
>            ConsumeToken();
>
> @@ -862,13 +867,61 @@ Optional<unsigned> Parser::ParseLambdaIn
>        } else if (Tok.is(tok::ellipsis))
>          EllipsisLoc = ConsumeToken();
>      }
> -
> -    Intro.addCapture(Kind, Loc, Id, EllipsisLoc, Init);
> +    // If this is an init capture, process the initialization expression
> +    // right away.  For lambda init-captures such as the following:
> +    // const int x = 10;
> +    //  auto L = [i = x+1](int a) {
> +    //    return [j = x+2,
> +    //           &k = x](char b) { };
> +    //  };
> +    // keep in mind that each lambda init-capture has to have:
> +    //  - its initialization expression executed in the context
> +    //    of the enclosing/parent decl-context.
> +    //  - but the variable itself has to be 'injected' into the
> +    //    decl-context of its lambda's call-operator (which has
> +    //    not yet been created).
> +    // Each init-expression is a full-expression that has to get
> +    // Sema-analyzed (for capturing etc.) before its lambda's
> +    // call-operator's decl-context, scope & scopeinfo are pushed on their
> +    // respective stacks.  Thus if any variable is odr-used in the init-capture
> +    // it will correctly get captured in the enclosing lambda, if one exists.
> +    // The init-variables above are created later once the lambdascope and
> +    // call-operators decl-context is pushed onto its respective stack.
> +
> +    // Since the lambda init-capture's initializer expression occurs in the
> +    // context of the enclosing function or lambda, therefore we can not wait
> +    // till a lambda scope has been pushed on before deciding whether the
> +    // variable needs to be captured.  We also need to process all
> +    // lvalue-to-rvalue conversions and discarded-value conversions,
> +    // so that we can avoid capturing certain constant variables.
> +    // For e.g.,
> +    //  void test() {
> +    //   const int x = 10;
> +    //   auto L = [&z = x](char a) { <-- don't capture by the current lambda
> +    //     return [y = x](int i) { <-- don't capture by enclosing lambda
> +    //          return y;
> +    //     }
> +    //   };
> +    // If x was not const, the second use would require 'L' to capture, and
> +    // that would be an error.
> +
> +    ParsedType InitCaptureParsedType;
> +    if (Init.isUsable()) {
> +      // Get the pointer and store it in an lvalue, so we can use it as an
> +      // out argument.
> +      Expr *InitExpr = Init.get();
> +      // This performs any lvalue-to-rvalue conversions if necessary, which
> +      // can affect what gets captured in the containing decl-context.
> +      QualType InitCaptureType = Actions.performLambdaInitCaptureInitialization(
> +        Loc, Kind == LCK_ByRef, Id, InitExpr);
> +      Init = InitExpr;
> +      InitCaptureParsedType.set(InitCaptureType);
> +    }
> +    Intro.addCapture(Kind, Loc, Id, EllipsisLoc, Init, InitCaptureParsedType);
>    }
>
>    T.consumeClose();
>    Intro.Range.setEnd(T.getCloseLocation());
> -
>    return DiagResult();
>  }
>
>
> Modified: cfe/branches/release_34/lib/Sema/SemaAccess.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaAccess.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaAccess.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaAccess.cpp Wed Dec  4 23:25:04 2013
> @@ -1650,9 +1650,9 @@ Sema::AccessResult Sema::CheckConstructo
>    }
>
>    case InitializedEntity::EK_LambdaCapture: {
> -    const VarDecl *Var = Entity.getCapturedVar();
> +    StringRef VarName = Entity.getCapturedVarName();
>      PD = PDiag(diag::err_access_lambda_capture);
> -    PD << Var->getName() << Entity.getType() << getSpecialMember(Constructor);
> +    PD << VarName << Entity.getType() << getSpecialMember(Constructor);
>      break;
>    }
>
>
> Modified: cfe/branches/release_34/lib/Sema/SemaExpr.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaExpr.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaExpr.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaExpr.cpp Wed Dec  4 23:25:04 2013
> @@ -11688,7 +11688,8 @@ static ExprResult addAsFieldToClosureTyp
>    SmallVector<InitializedEntity, 4> Entities;
>    Entities.reserve(1 + IndexVariables.size());
>    Entities.push_back(
> -    InitializedEntity::InitializeLambdaCapture(Var, Field, Loc));
> +    InitializedEntity::InitializeLambdaCapture(Var->getIdentifier(),
> +        Field->getType(), Loc));
>    for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I)
>      Entities.push_back(InitializedEntity::InitializeElement(S.Context,
>                                                              0,
>
> Modified: cfe/branches/release_34/lib/Sema/SemaExprCXX.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaExprCXX.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaExprCXX.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaExprCXX.cpp Wed Dec  4 23:25:04 2013
> @@ -5929,13 +5929,30 @@ static void CheckLambdaCaptures(Expr *co
>
>  ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC,
>                                       bool DiscardedValue,
> -                                     bool IsConstexpr) {
> +                                     bool IsConstexpr,
> +                                     bool IsLambdaInitCaptureInitializer) {
>    ExprResult FullExpr = Owned(FE);
>
>    if (!FullExpr.get())
>      return ExprError();
> -
> -  if (DiagnoseUnexpandedParameterPack(FullExpr.get()))
> +
> +  // If we are an init-expression in a lambdas init-capture, we should not
> +  // diagnose an unexpanded pack now (will be diagnosed once lambda-expr
> +  // containing full-expression is done).
> +  // template<class ... Ts> void test(Ts ... t) {
> +  //   test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now.
> +  //     return a;
> +  //   }() ...);
> +  // }
> +  // FIXME: This is a hack. It would be better if we pushed the lambda scope
> +  // when we parse the lambda introducer, and teach capturing (but not
> +  // unexpanded pack detection) to walk over LambdaScopeInfos which don't have a
> +  // corresponding class yet (that is, have LambdaScopeInfo either represent a
> +  // lambda where we've entered the introducer but not the body, or represent a
> +  // lambda where we've entered the body, depending on where the
> +  // parser/instantiation has got to).
> +  if (!IsLambdaInitCaptureInitializer &&
> +      DiagnoseUnexpandedParameterPack(FullExpr.get()))
>      return ExprError();
>
>    // Top-level expressions default to 'id' when we're in a debugger.
>
> Modified: cfe/branches/release_34/lib/Sema/SemaInit.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaInit.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaInit.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaInit.cpp Wed Dec  4 23:25:04 2013
> @@ -2506,7 +2506,7 @@ DeclarationName InitializedEntity::getNa
>      return VariableOrMember->getDeclName();
>
>    case EK_LambdaCapture:
> -    return Capture.Var->getDeclName();
> +    return DeclarationName(Capture.VarID);
>
>    case EK_Result:
>    case EK_Exception:
> @@ -2608,7 +2608,7 @@ unsigned InitializedEntity::dumpImpl(raw
>    case EK_BlockElement: OS << "Block"; break;
>    case EK_LambdaCapture:
>      OS << "LambdaCapture ";
> -    getCapturedVar()->printName(OS);
> +    OS << DeclarationName(Capture.VarID);
>      break;
>    }
>
>
> Modified: cfe/branches/release_34/lib/Sema/SemaLambda.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaLambda.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaLambda.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaLambda.cpp Wed Dec  4 23:25:04 2013
> @@ -609,12 +609,20 @@ void Sema::deduceClosureReturnType(Captu
>    }
>  }
>
> -VarDecl *Sema::checkInitCapture(SourceLocation Loc, bool ByRef,
> -                                IdentifierInfo *Id, Expr *Init) {
> -  // C++1y [expr.prim.lambda]p11:
> -  //   An init-capture behaves as if it declares and explicitly captures
> -  //   a variable of the form
> -  //     "auto init-capture;"
> +QualType Sema::performLambdaInitCaptureInitialization(SourceLocation Loc,
> +                                                      bool ByRef,
> +                                                      IdentifierInfo *Id,
> +                                                      Expr *&Init) {
> +
> +  // We do not need to distinguish between direct-list-initialization
> +  // and copy-list-initialization here, because we will always deduce
> +  // std::initializer_list<T>, and direct- and copy-list-initialization
> +  // always behave the same for such a type.
> +  // FIXME: We should model whether an '=' was present.
> +  const bool IsDirectInit = isa<ParenListExpr>(Init) || isa<InitListExpr>(Init);
> +
> +  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
> +  // deduce against.
>    QualType DeductType = Context.getAutoDeductType();
>    TypeLocBuilder TLB;
>    TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
> @@ -625,24 +633,100 @@ VarDecl *Sema::checkInitCapture(SourceLo
>    }
>    TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
>
> +  // Are we a non-list direct initialization?
> +  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
> +
> +  Expr *DeduceInit = Init;
> +  // Initializer could be a C++ direct-initializer. Deduction only works if it
> +  // contains exactly one expression.
> +  if (CXXDirectInit) {
> +    if (CXXDirectInit->getNumExprs() == 0) {
> +      Diag(CXXDirectInit->getLocStart(), diag::err_init_capture_no_expression)
> +          << DeclarationName(Id) << TSI->getType() << Loc;
> +      return QualType();
> +    } else if (CXXDirectInit->getNumExprs() > 1) {
> +      Diag(CXXDirectInit->getExpr(1)->getLocStart(),
> +           diag::err_init_capture_multiple_expressions)
> +          << DeclarationName(Id) << TSI->getType() << Loc;
> +      return QualType();
> +    } else {
> +      DeduceInit = CXXDirectInit->getExpr(0);
> +    }
> +  }
> +
> +  // Now deduce against the initialization expression and store the deduced
> +  // type below.
> +  QualType DeducedType;
> +  if (DeduceAutoType(TSI, DeduceInit, DeducedType) == DAR_Failed) {
> +    if (isa<InitListExpr>(Init))
> +      Diag(Loc, diag::err_init_capture_deduction_failure_from_init_list)
> +          << DeclarationName(Id)
> +          << (DeduceInit->getType().isNull() ? TSI->getType()
> +                                             : DeduceInit->getType())
> +          << DeduceInit->getSourceRange();
> +    else
> +      Diag(Loc, diag::err_init_capture_deduction_failure)
> +          << DeclarationName(Id) << TSI->getType()
> +          << (DeduceInit->getType().isNull() ? TSI->getType()
> +                                             : DeduceInit->getType())
> +          << DeduceInit->getSourceRange();
> +  }
> +  if (DeducedType.isNull())
> +    return QualType();
> +
> +  // Perform initialization analysis and ensure any implicit conversions
> +  // (such as lvalue-to-rvalue) are enforced.
> +  InitializedEntity Entity =
> +      InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
> +  InitializationKind Kind =
> +      IsDirectInit
> +          ? (CXXDirectInit ? InitializationKind::CreateDirect(
> +                                 Loc, Init->getLocStart(), Init->getLocEnd())
> +                           : InitializationKind::CreateDirectList(Loc))
> +          : InitializationKind::CreateCopy(Loc, Init->getLocStart());
> +
> +  MultiExprArg Args = Init;
> +  if (CXXDirectInit)
> +    Args =
> +        MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
> +  QualType DclT;
> +  InitializationSequence InitSeq(*this, Entity, Kind, Args);
> +  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
> +
> +  if (Result.isInvalid())
> +    return QualType();
> +  Init = Result.takeAs<Expr>();
> +
> +  // The init-capture initialization is a full-expression that must be
> +  // processed as one before we enter the declcontext of the lambda's
> +  // call-operator.
> +  Result = ActOnFinishFullExpr(Init, Loc, /*DiscardedValue*/ false,
> +                               /*IsConstexpr*/ false,
> +                               /*IsLambdaInitCaptureInitalizer*/ true);
> +  if (Result.isInvalid())
> +    return QualType();
> +
> +  Init = Result.takeAs<Expr>();
> +  return DeducedType;
> +}
> +
> +VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
> +    QualType InitCaptureType, IdentifierInfo *Id, Expr *Init) {
> +
> +  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType,
> +      Loc);
>    // Create a dummy variable representing the init-capture. This is not actually
>    // used as a variable, and only exists as a way to name and refer to the
>    // init-capture.
>    // FIXME: Pass in separate source locations for '&' and identifier.
>    VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
> -                                   Loc, Id, TSI->getType(), TSI, SC_Auto);
> +                                   Loc, Id, InitCaptureType, TSI, SC_Auto);
>    NewVD->setInitCapture(true);
>    NewVD->setReferenced(true);
>    NewVD->markUsed(Context);
> -
> -  // We do not need to distinguish between direct-list-initialization
> -  // and copy-list-initialization here, because we will always deduce
> -  // std::initializer_list<T>, and direct- and copy-list-initialization
> -  // always behave the same for such a type.
> -  // FIXME: We should model whether an '=' was present.
> -  bool DirectInit = isa<ParenListExpr>(Init) || isa<InitListExpr>(Init);
> -  AddInitializerToDecl(NewVD, Init, DirectInit, /*ContainsAuto*/true);
> +  NewVD->setInit(Init);
>    return NewVD;
> +
>  }
>
>  FieldDecl *Sema::buildInitCaptureField(LambdaScopeInfo *LSI, VarDecl *Var) {
> @@ -816,7 +900,7 @@ void Sema::ActOnStartOfLambdaDefinition(
>      if (C->Init.isInvalid())
>        continue;
>
> -    VarDecl *Var;
> +    VarDecl *Var = 0;
>      if (C->Init.isUsable()) {
>        Diag(C->Loc, getLangOpts().CPlusPlus1y
>                         ? diag::warn_cxx11_compat_init_capture
> @@ -824,9 +908,15 @@ void Sema::ActOnStartOfLambdaDefinition(
>
>        if (C->Init.get()->containsUnexpandedParameterPack())
>          ContainsUnexpandedParameterPack = true;
> -
> -      Var = checkInitCapture(C->Loc, C->Kind == LCK_ByRef,
> -                             C->Id, C->Init.take());
> +      // If the initializer expression is usable, but the InitCaptureType
> +      // is not, then an error has occurred - so ignore the capture for now.
> +      // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
> +      // FIXME: we should create the init capture variable and mark it invalid
> +      // in this case.
> +      if (C->InitCaptureType.get().isNull())
> +        continue;
> +      Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
> +            C->Id, C->Init.take());
>        // C++1y [expr.prim.lambda]p11:
>        //   An init-capture behaves as if it declares and explicitly
>        //   captures a variable [...] whose declarative region is the
>
> Modified: cfe/branches/release_34/lib/Sema/SemaTemplateInstantiate.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/SemaTemplateInstantiate.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/SemaTemplateInstantiate.cpp (original)
> +++ cfe/branches/release_34/lib/Sema/SemaTemplateInstantiate.cpp Wed Dec  4 23:25:04 2013
> @@ -917,7 +917,8 @@ namespace {
>      }
>
>      ExprResult TransformLambdaScope(LambdaExpr *E,
> -                                    CXXMethodDecl *NewCallOperator) {
> +        CXXMethodDecl *NewCallOperator,
> +        ArrayRef<InitCaptureInfoTy> InitCaptureExprsAndTypes) {
>        CXXMethodDecl *const OldCallOperator = E->getCallOperator();
>        // In the generic lambda case, we set the NewTemplate to be considered
>        // an "instantiation" of the OldTemplate.
> @@ -936,7 +937,8 @@ namespace {
>          NewCallOperator->setInstantiationOfMemberFunction(OldCallOperator,
>                                                      TSK_ImplicitInstantiation);
>
> -      return inherited::TransformLambdaScope(E, NewCallOperator);
> +      return inherited::TransformLambdaScope(E, NewCallOperator,
> +          InitCaptureExprsAndTypes);
>      }
>      TemplateParameterList *TransformTemplateParameterList(
>                                TemplateParameterList *OrigTPL)  {
>
> Modified: cfe/branches/release_34/lib/Sema/TreeTransform.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/lib/Sema/TreeTransform.h?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/lib/Sema/TreeTransform.h (original)
> +++ cfe/branches/release_34/lib/Sema/TreeTransform.h Wed Dec  4 23:25:04 2013
> @@ -593,9 +593,11 @@ public:
>
>    StmtResult TransformCompoundStmt(CompoundStmt *S, bool IsStmtExpr);
>    ExprResult TransformCXXNamedCastExpr(CXXNamedCastExpr *E);
> -
> +
> +  typedef std::pair<ExprResult, QualType> InitCaptureInfoTy;
>    /// \brief Transform the captures and body of a lambda expression.
> -  ExprResult TransformLambdaScope(LambdaExpr *E, CXXMethodDecl *CallOperator);
> +  ExprResult TransformLambdaScope(LambdaExpr *E, CXXMethodDecl *CallOperator,
> +       ArrayRef<InitCaptureInfoTy> InitCaptureExprsAndTypes);
>
>    TemplateParameterList *TransformTemplateParameterList(
>          TemplateParameterList *TPL) {
> @@ -8275,7 +8277,40 @@ TreeTransform<Derived>::TransformCXXTemp
>  template<typename Derived>
>  ExprResult
>  TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
> -
> +
> +  // Transform any init-capture expressions before entering the scope of the
> +  // lambda body, because they are not semantically within that scope.
> +  SmallVector<InitCaptureInfoTy, 8> InitCaptureExprsAndTypes;
> +  InitCaptureExprsAndTypes.resize(E->explicit_capture_end() -
> +      E->explicit_capture_begin());
> +
> +  for (LambdaExpr::capture_iterator C = E->capture_begin(),
> +      CEnd = E->capture_end();
> +      C != CEnd; ++C) {
> +    if (!C->isInitCapture())
> +      continue;
> +    EnterExpressionEvaluationContext  EEEC(getSema(),
> +        Sema::PotentiallyEvaluated);
> +    ExprResult NewExprInitResult = getDerived().TransformInitializer(
> +        C->getCapturedVar()->getInit(),
> +        C->getCapturedVar()->getInitStyle() == VarDecl::CallInit);
> +
> +    if (NewExprInitResult.isInvalid())
> +      return ExprError();
> +    Expr *NewExprInit = NewExprInitResult.get();
> +
> +    VarDecl *OldVD = C->getCapturedVar();
> +    QualType NewInitCaptureType =
> +        getSema().performLambdaInitCaptureInitialization(C->getLocation(),
> +            OldVD->getType()->isReferenceType(), OldVD->getIdentifier(),
> +            NewExprInit);
> +    NewExprInitResult = NewExprInit;
> +    VarDecl *NewVD = 0;
> +    InitCaptureExprsAndTypes[C - E->capture_begin()] =
> +        std::make_pair(NewExprInitResult, NewInitCaptureType);
> +
> +  }
> +
>    LambdaScopeInfo *LSI = getSema().PushLambdaScope();
>    // Transform the template parameters, and add them to the current
>    // instantiation scope. The null case is handled correctly.
> @@ -8370,31 +8405,17 @@ TreeTransform<Derived>::TransformLambdaE
>
>    getDerived().transformAttrs(E->getCallOperator(), NewCallOperator);
>
> -  return getDerived().TransformLambdaScope(E, NewCallOperator);
> +  return getDerived().TransformLambdaScope(E, NewCallOperator,
> +      InitCaptureExprsAndTypes);
>  }
>
>  template<typename Derived>
>  ExprResult
>  TreeTransform<Derived>::TransformLambdaScope(LambdaExpr *E,
> -                                             CXXMethodDecl *CallOperator) {
> +    CXXMethodDecl *CallOperator,
> +    ArrayRef<InitCaptureInfoTy> InitCaptureExprsAndTypes) {
>    bool Invalid = false;
>
> -  // Transform any init-capture expressions before entering the scope of the
> -  // lambda.
> -  SmallVector<ExprResult, 8> InitCaptureExprs;
> -  InitCaptureExprs.resize(E->explicit_capture_end() -
> -                          E->explicit_capture_begin());
> -  for (LambdaExpr::capture_iterator C = E->capture_begin(),
> -                                 CEnd = E->capture_end();
> -       C != CEnd; ++C) {
> -    if (!C->isInitCapture())
> -      continue;
> -    InitCaptureExprs[C - E->capture_begin()] =
> -        getDerived().TransformInitializer(
> -            C->getCapturedVar()->getInit(),
> -            C->getCapturedVar()->getInitStyle() == VarDecl::CallInit);
> -  }
> -
>    // Introduce the context of the call operator.
>    Sema::ContextRAII SavedContext(getSema(), CallOperator);
>
> @@ -8427,19 +8448,24 @@ TreeTransform<Derived>::TransformLambdaS
>
>      // Rebuild init-captures, including the implied field declaration.
>      if (C->isInitCapture()) {
> -      ExprResult Init = InitCaptureExprs[C - E->capture_begin()];
> -      if (Init.isInvalid()) {
> +
> +      InitCaptureInfoTy InitExprTypePair =
> +          InitCaptureExprsAndTypes[C - E->capture_begin()];
> +      ExprResult Init = InitExprTypePair.first;
> +      QualType InitQualType = InitExprTypePair.second;
> +      if (Init.isInvalid() || InitQualType.isNull()) {
>          Invalid = true;
>          continue;
>        }
>        VarDecl *OldVD = C->getCapturedVar();
> -      VarDecl *NewVD = getSema().checkInitCapture(
> -          C->getLocation(), OldVD->getType()->isReferenceType(),
> -          OldVD->getIdentifier(), Init.take());
> +      VarDecl *NewVD = getSema().createLambdaInitCaptureVarDecl(
> +          OldVD->getLocation(), InitExprTypePair.second,
> +          OldVD->getIdentifier(), Init.get());
>        if (!NewVD)
>          Invalid = true;
> -      else
> +      else {
>          getDerived().transformedLocalDecl(OldVD, NewVD);
> +      }
>        getSema().buildInitCaptureField(LSI, NewVD);
>        continue;
>      }
>
> Modified: cfe/branches/release_34/test/SemaCXX/cxx1y-init-captures.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_34/test/SemaCXX/cxx1y-init-captures.cpp?rev=196470&r1=196469&r2=196470&view=diff
> ==============================================================================
> --- cfe/branches/release_34/test/SemaCXX/cxx1y-init-captures.cpp (original)
> +++ cfe/branches/release_34/test/SemaCXX/cxx1y-init-captures.cpp Wed Dec  4 23:25:04 2013
> @@ -1,14 +1,169 @@
> -// RUN: %clang_cc1 -std=c++1y %s -verify
> +// RUN: %clang_cc1 -std=c++1y %s -verify -emit-llvm-only
>
> -// expected-no-diagnostics
>  namespace variadic_expansion {
> -  void f(int &, char &);
> -
> -  template <typename ... T> void g(T &... t) {
> +  int f(int &, char &) { return 0; }
> +  template<class ... Ts> char fv(Ts ... ts) { return 0; }
> +  // FIXME: why do we get 2 error messages
> +  template <typename ... T> void g(T &... t) { //expected-note3{{declared here}}
>      f([&a(t)]()->decltype(auto) {
>        return a;
>      }() ...);
> +
> +    auto L = [x = f([&a(t)]()->decltype(auto) { return a; }()...)]() { return x; };
> +    const int y = 10;
> +    auto M = [x = y,
> +                &z = y](T& ... t) { };
> +    auto N = [x = y,
> +                &z = y, n = f(t...),
> +                o = f([&a(t)](T& ... t)->decltype(auto) { return a; }(t...)...), t...](T& ... s) {
> +                  fv([&a(t)]()->decltype(auto) {
> +                    return a;
> +                  }() ...);
> +                };
> +    auto N2 = [x = y,                     //expected-note3{{begins here}}
> +                &z = y, n = f(t...),
> +                o = f([&a(t)](T& ... t)->decltype(auto) { return a; }(t...)...)](T& ... s) {
> +                  fv([&a(t)]()->decltype(auto) { //expected-error 3{{captured}}
> +                    return a;
> +                  }() ...);
> +                };
> +
> +  }
> +
> +  void h(int i, char c) { g(i, c); } //expected-note{{in instantiation}}
> +}
> +
> +namespace odr_use_within_init_capture {
> +
> +int test() {
> +
> +  { // no captures
> +    const int x = 10;
> +    auto L = [z = x + 2](int a) {
> +      auto M = [y = x - 2](char b) {
> +        return y;
> +      };
> +      return M;
> +    };
> +
> +  }
> +  { // should not capture
> +    const int x = 10;
> +    auto L = [&z = x](int a) {
> +      return a;;
> +    };
> +
> +  }
> +  {
> +    const int x = 10;
> +    auto L = [k = x](char a) { //expected-note {{declared}}
> +      return [](int b) { //expected-note {{begins}}
> +        return [j = k](int c) { //expected-error {{cannot be implicitly captured}}
> +          return c;
> +        };
> +      };
> +    };
> +  }
> +  {
> +    const int x = 10;
> +    auto L = [k = x](char a) {
> +      return [=](int b) {
> +        return [j = k](int c) {
> +          return c;
> +        };
> +      };
> +    };
>    }
> +  {
> +    const int x = 10;
> +    auto L = [k = x](char a) {
> +      return [k](int b) {
> +        return [j = k](int c) {
> +          return c;
> +        };
> +      };
> +    };
> +  }
> +
> +  return 0;
> +}
>
> -  void h(int i, char c) { g(i, c); }
> +int run = test();
> +
> +}
> +
> +namespace odr_use_within_init_capture_template {
> +
> +template<class T = int>
> +int test(T t = T{}) {
> +
> +  { // no captures
> +    const T x = 10;
> +    auto L = [z = x](char a) {
> +      auto M = [y = x](T b) {
> +        return y;
> +      };
> +      return M;
> +    };
> +
> +  }
> +  { // should not capture
> +    const T x = 10;
> +    auto L = [&z = x](T a) {
> +      return a;;
> +    };
> +
> +  }
> +  { // will need to capture x in outer lambda
> +    const T x = 10; //expected-note {{declared}}
> +    auto L = [z = x](char a) { //expected-note {{begins}}
> +      auto M = [&y = x](T b) { //expected-error {{cannot be implicitly captured}}
> +        return y;
> +      };
> +      return M;
> +    };
> +
> +  }
> +  { // will need to capture x in outer lambda
> +    const T x = 10;
> +    auto L = [=,z = x](char a) {
> +      auto M = [&y = x](T b) {
> +        return y;
> +      };
> +      return M;
> +    };
> +
> +  }
> +  { // will need to capture x in outer lambda
> +    const T x = 10;
> +    auto L = [x, z = x](char a) {
> +      auto M = [&y = x](T b) {
> +        return y;
> +      };
> +      return M;
> +    };
> +  }
> +  { // will need to capture x in outer lambda
> +    const int x = 10; //expected-note 2{{declared}}
> +    auto L = [z = x](char a) { //expected-note 2{{begins}}
> +      auto M = [&y = x](T b) { //expected-error 2{{cannot be implicitly captured}}
> +        return y;
> +      };
> +      return M;
> +    };
> +  }
> +  {
> +    // no captures
> +    const T x = 10;
> +    auto L = [z =
> +                  [z = x, &y = x](char a) { return z + y; }('a')](char a)
> +      { return z; };
> +
> +  }
> +
> +  return 0;
>  }
> +
> +int run = test(); //expected-note {{instantiation}}
> +
> +}
> \ No newline at end of file
>
>
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