On Tue, Mar 22, 2016 at 6:12 PM, Patrick Palka <patrick@parcs.ath.cx> wrote:
On Tue, Mar 22, 2016 at 6:00 PM, Jason Merrill <jason@redhat.com> wrote:
On 03/22/2016 05:35 PM, Patrick Palka wrote:
+ if (cp_unevaluated_operand == 0
Why check this here?
Just so that the change doesn't affect the behavior of tsubst_decl()
when cp_unevaluated_operand != 0. Presumably the existing code (10
lines below) handles that case just fine.
Turns out that without the check we can trigger the cxx_dialect >=
cxx14 assert because in c++11 mode we can reach the assert through
get_defaulted_eh_spec() which increments cp_unevaluated_operand and
then calls get_nsdmi (..., /*in_ctor=*/false) causing
current_class_ref to get set to a PLACEHOLDER_EXPR.
So for example g++.dg/cpp0x/nsdmi-template2.C regresses with an ICE.
So it seems the cp_unevaluated_operand != 0 check is necessary as long
as the assert stays.
There are no regressions if both the cp_unevaluated_operand check and
the assert are removed however.