[Bug c++/38958] 'unused variable' warning emitted when extending the lifetime of a returned RAII type by holding a reference to const despite delayed destructor side-effects. [dtor]

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38958

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Jan  7 15:18:05 2015
New Revision: 219306

URL: https://gcc.gnu.org/viewcvs?rev=219306&root=gcc&view=rev
Log:
    PR c++/63657
    PR c++/38958
    * call.c (set_up_extended_ref_temp): Set TREE_USED on the reference
    if the temporary has a non-trivial destructor.
    * decl.c (poplevel): Don't look through references.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/warn/Wunused-var-22.C
Modified:
    branches/gcc-4_9-branch/gcc/cp/ChangeLog
    branches/gcc-4_9-branch/gcc/cp/call.c
    branches/gcc-4_9-branch/gcc/cp/decl.c