Implement C++11 [conv.prom]p4: an enumeration with a fixed underlying type has
integral promotions to both its underlying type and to its underlying type's
promoted type. This matters now that boolean conversions aren't permitted in
converted constant expressions (a la DR1407): an enumerator with a fixed
underlying type of bool still can be.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163841 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 4dca91d..72701dd 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -2593,8 +2593,16 @@
case ICK_Integral_Promotion:
case ICK_Integral_Conversion:
- From = ImpCastExprToType(From, ToType, CK_IntegralCast,
- VK_RValue, /*BasePath=*/0, CCK).take();
+ if (ToType->isBooleanType()) {
+ assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
+ SCS.Second == ICK_Integral_Promotion &&
+ "only enums with fixed underlying type can promote to bool");
+ From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean,
+ VK_RValue, /*BasePath=*/0, CCK).take();
+ } else {
+ From = ImpCastExprToType(From, ToType, CK_IntegralCast,
+ VK_RValue, /*BasePath=*/0, CCK).take();
+ }
break;
case ICK_Floating_Promotion: