https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105931
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:5cf4746c3d4e80a360bd15b31136339d6812597e commit r12-8513-g5cf4746c3d4e80a360bd15b31136339d6812597e Author: Patrick Palka <ppa...@redhat.com> Date: Thu Jun 23 16:36:43 2022 -0400 c++: constexpr folding in unevaluated context [PR105931] Changing the type of N from int to unsigned in decltype82.C (from r13-986-g0ecb6b906f215e) reveals another spot where we perform constexpr evaluation in an unevaluated context for sake of warnings, this time from the call to shorten_compare in cp_build_binary_op, which calls fold_for_warn. We could (and probably should) suppress the shorten_compare warnings when in an unevaluated context, but there's probably other callers of fold_for_warn that are similarly affected. So this patch takes the approach of directly suppressing fold_for_warn when in an unevaluated context. PR c++/105931 gcc/cp/ChangeLog: * expr.cc (fold_for_warn): Don't fold when in an unevaluated context. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/decltype82a.C: New test. (cherry picked from commit b00b95198e6720eb23a2618870d67800f6180fdd)
