[Bug c++/89481] constexpr function allows writing one active union member and reading another

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89481

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Tue Feb 26 14:37:39 2019
New Revision: 269213

URL: https://gcc.gnu.org/viewcvs?rev=269213&root=gcc&view=rev
Log:
        PR c++/89481
        * constexpr.c (cxx_eval_store_expression): When changing active union
        member, set no_zero_init.

        * g++.dg/cpp1y/constexpr-89481.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/cpp1y/constexpr-89481.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/constexpr.c
    trunk/gcc/testsuite/ChangeLog