[Bug c++/84839] [6/7 Regression] ICE (Segmentation fault) when `decltype` is used with parameter pack

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84839

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Mar 23 14:39:36 2018
New Revision: 258810

URL: https://gcc.gnu.org/viewcvs?rev=258810&root=gcc&view=rev
Log:
        PR c++/84839 - ICE with decltype of parameter pack.

        * pt.c (tsubst_pack_expansion): Set cp_unevaluated_operand while
        instantiating dummy parms.

Added:
    branches/gcc-7-branch/gcc/testsuite/g++.dg/cpp0x/variadic-nested2.C
Modified:
    branches/gcc-7-branch/gcc/cp/ChangeLog
    branches/gcc-7-branch/gcc/cp/pt.c