PR23833, DR2140: an lvalue-to-rvalue conversion on a glvalue of type
nullptr_t does not access memory.
We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.
llvm-svn: 345562
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 038fef1..9844775 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -623,8 +623,11 @@
if (E->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
Cleanup.setExprNeedsCleanups(true);
- ExprResult Res = ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, E,
- nullptr, VK_RValue);
+ // C++ [conv.lval]p3:
+ // If T is cv std::nullptr_t, the result is a null pointer constant.
+ CastKind CK = T->isNullPtrType() ? CK_NullToPointer : CK_LValueToRValue;
+ ExprResult Res =
+ ImplicitCastExpr::Create(Context, T, CK, E, nullptr, VK_RValue);
// C11 6.3.2.1p2:
// ... if the lvalue has atomic type, the value has the non-atomic version
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 29119a7..0bf2578 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -7644,9 +7644,13 @@
case SK_LValueToRValue: {
assert(CurInit.get()->isGLValue() && "cannot load from a prvalue");
- CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
- CK_LValueToRValue, CurInit.get(),
- /*BasePath=*/nullptr, VK_RValue);
+ // C++ [conv.lval]p3:
+ // If T is cv std::nullptr_t, the result is a null pointer constant.
+ CastKind CK =
+ Step->Type->isNullPtrType() ? CK_NullToPointer : CK_LValueToRValue;
+ CurInit =
+ ImplicitCastExpr::Create(S.Context, Step->Type, CK, CurInit.get(),
+ /*BasePath=*/nullptr, VK_RValue);
break;
}