Index: include/clang/Basic/DiagnosticSemaKinds.td =================================================================== --- include/clang/Basic/DiagnosticSemaKinds.td +++ include/clang/Basic/DiagnosticSemaKinds.td @@ -5938,6 +5938,9 @@ def err_bad_lvalue_to_rvalue_cast : Error< "cannot cast from lvalue of type %1 to rvalue reference type %2; types are " "not compatible">; +def err_bad_rvalue_to_rvalue_cast : Error< + "cannot cast from rvalue reference of type %1 to rvalue reference type %2; types are " + "not compatible">; def err_bad_static_cast_pointer_nonpointer : Error< "cannot cast from type %1 to pointer type %2">; def err_bad_static_cast_member_pointer_nonmp : Error< Index: lib/Sema/SemaCast.cpp =================================================================== --- lib/Sema/SemaCast.cpp +++ lib/Sema/SemaCast.cpp @@ -983,7 +983,7 @@ // C++11 [expr.static.cast]p3: // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to cv2 // T2" if "cv2 T2" is reference-compatible with "cv1 T1". - tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind, + tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind, BasePath, msg); if (tcr != TC_NotApplicable) return tcr; @@ -1134,10 +1134,10 @@ } /// Tests whether a conversion according to N2844 is valid. -TryCastResult -TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType, - bool CStyle, CastKind &Kind, CXXCastPath &BasePath, - unsigned &msg) { +TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, + QualType DestType, bool CStyle, + CastKind &Kind, CXXCastPath &BasePath, + unsigned &msg) { // C++11 [expr.static.cast]p3: // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to // cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1". @@ -1160,15 +1160,15 @@ FromType = FromType.getUnqualifiedType(); ToType = ToType.getUnqualifiedType(); } - - if (Self.CompareReferenceRelationship(SrcExpr->getLocStart(), - ToType, FromType, - DerivedToBase, ObjCConversion, - ObjCLifetimeConversion) - != Sema::Ref_Compatible) { - if (CStyle) + + Sema::ReferenceCompareResult RefResult = Self.CompareReferenceRelationship( + SrcExpr->getLocStart(), ToType, FromType, DerivedToBase, ObjCConversion, + ObjCLifetimeConversion); + if (RefResult != Sema::Ref_Compatible) { + if (CStyle || RefResult == Sema::Ref_Incompatible) return TC_NotApplicable; - msg = diag::err_bad_lvalue_to_rvalue_cast; + msg = SrcExpr->isLValue() ? diag::err_bad_lvalue_to_rvalue_cast + : diag::err_bad_rvalue_to_rvalue_cast; return TC_Failed; } Index: test/SemaCXX/rval-references.cpp =================================================================== --- test/SemaCXX/rval-references.cpp +++ test/SemaCXX/rval-references.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify -std=c++11 %s +// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify -std=c++11 %s typedef int&& irr; typedef irr& ilr_c1; // Collapses to int& @@ -30,11 +30,15 @@ int &&virr2 = 0; int &&virr3 = virr2; // expected-error {{rvalue reference to type 'int' cannot bind to lvalue of type 'int'}} int i1 = 0; + const double d1 = 0; + const int ci1 = 1; int &&virr4 = i1; // expected-error {{rvalue reference to type 'int' cannot bind to lvalue of type 'int'}} int &&virr5 = ret_irr(); int &&virr6 = static_cast(i1); - (void)static_cast(i1); // expected-error {{types are not compatible}} - + (void)static_cast(i1); // expected-error {{reference to type 'not_int' could not bind to an lvalue of type 'int'}} + (void)static_cast(static_cast(i1)); // expected-error {{cannot cast from rvalue reference of type 'const int' to rvalue reference type 'int &&'}} + (void)static_cast(ci1); // expected-error {{types are not compatible}} + (void)static_cast(d1); int i2 = over(i1); not_int ni1 = over(0); int i3 = over(virr2);