On 1/25/19 12:09 PM, Marek Polacek wrote:
On Fri, Jan 25, 2019 at 10:55:55AM -0600, Tim Song wrote:
On Thu, Jan 24, 2019 at 4:14 PM Jason Merrill <ja...@redhat.com> wrote:
On 1/24/19 2:16 PM, Marek Polacek wrote:
This test ICEs since r159006 which added
type = ENUM_UNDERLYING_TYPE (type);
to type_promotes_to. In this test ENUM_UNDERLYING_TYPE is null because we
haven't yet parsed '}' of the enum and the underlying type isn't fixed, and
so checking TYPE_UNSIGNED crashed.
I've added some checks to the test to see if the types seem to be OK; clang++
agrees.
Bootstrapped/regtested on x86_64-linux, ok for trunk/8/7?
2019-01-24 Marek Polacek <pola...@redhat.com>
PR c++/89024 - ICE with incomplete enum type.
* cvt.c (type_promotes_to): Check if prom is non-null.
9.6/6: An enumeration whose underlying type is not fixed is an
incomplete type from its point of declaration to immediately after the
closing } of its enum-specifier, at which point it becomes a complete type.
So the conversion is ill-formed.
Jason
But the conversion in the example (in
decltype(__test_aux<_To1>(declval<_From1>())))
is in a SFINAE context, so shouldn't it gracefully fall back to the
`(...)` overload?
I think so, and clang++ and icc also compile the testcase fine (and we used to
too, before r159006).
Absolutely, the conversion being ill-formed means substitution fails,
and we reject that candidate. I meant that we shouldn't get as far as
type_promotes_to for an incomplete type.
Jason
