https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108554
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:2fdfa3768b25c85df39eaf9b850e130e42a4dd6f commit r12-9345-g2fdfa3768b25c85df39eaf9b850e130e42a4dd6f Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Jan 26 10:55:28 2023 +0000 libstdc++: Add returns_nonnull to non-inline std::map detail [PR108554] std::map uses a non-inline function to rebalance its tree and the compiler can't see that it always returns a valid pointer (assuming valid inputs, which is a precondition anyway). This can result in -Wnull-derefernce warnings for valid code, because the compiler thinks there is a path where the function returns null. Adding the returns_nonnull attribute tells the compiler that is can't happen. While we're doing that, we might as well also add a nonnull attribute to the rebalancing functions too. libstdc++-v3/ChangeLog: PR libstdc++/108554 * include/bits/stl_tree.h (_Rb_tree_insert_and_rebalance): Add nonnull attribute. (_Rb_tree_rebalance_for_erase): Add nonnull and returns_nonnull attributes. * testsuite/23_containers/map/modifiers/108554.cc: New test. (cherry picked from commit 3376467ce090aa0966d59ca3aea35db4f17a4b47)
