On 04/07/2011 05:41 PM, Jason Merrill wrote:
PR 48450 has to do with SFINAE bugs, but one of them turns out to be a
different sort of bug: we were failing to convert from a non-constant
value of scoped enum type to bool, because that conversion was doing a
!= 0, which requires an implicit conversion to int. So now we explicitly
convert to the underlying integral type first, and prevent c-common from
helpfully removing it again.
...except that if the underlying type is bool, this leads to infinite
recursion. So use build_nop instead of convert.
Tested x86_64-pc-linux-gnu, applying to trunk and 4.6.
commit a2873eda4e9932624a2cd1ec77fb7554206b3574
Author: Jason Merrill <ja...@redhat.com>
Date: Sun Apr 10 08:33:43 2011 -0400
PR c++/48534
* cvt.c (ocp_convert): Use build_nop to convert to underlying type
of scoped enum.
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index 6551de6..de981bc 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -731,7 +731,7 @@ ocp_convert (tree type, tree expr, int convtype, int flags)
/* We can't implicitly convert a scoped enum to bool, so convert
to the underlying type first. */
if (SCOPED_ENUM_P (intype) && (convtype & CONV_STATIC))
- e = convert (ENUM_UNDERLYING_TYPE (intype), e);
+ e = build_nop (ENUM_UNDERLYING_TYPE (intype), e);
return cp_truthvalue_conversion (e);
}
diff --git a/gcc/testsuite/g++.dg/cpp0x/enum10.C
b/gcc/testsuite/g++.dg/cpp0x/enum10.C
new file mode 100644
index 0000000..55a1ab4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/enum10.C
@@ -0,0 +1,9 @@
+// PR c++/48534
+// { dg-options -std=c++0x }
+
+enum class OpSE : bool;
+
+int main()
+{
+ return static_cast<bool>(OpSE());
+}
