https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118681
--- Comment #13 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-15 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:2de64a64b41989682dcdc621fd72fe107fec8b95 commit r15-9951-g2de64a64b41989682dcdc621fd72fe107fec8b95 Author: Jonathan Wakely <jwak...@redhat.com> Date: Fri Jul 4 16:44:13 2025 +0100 libstdc++: Ensure pool resources meet alignment requirements [PR118681] For allocations with size > alignment and size % alignment != 0 we were sometimes returning pointers that did not meet the requested aligment. For example, allocate(24, 16) would select the pool for 24-byte objects and the second allocation from that pool (at offset 24 bytes into the pool) is only 8-byte aligned not 16-byte aligned. The pool resources need to round up the requested allocation size to a multiple of the alignment, so that the selected pool will always return allocations that meet the alignment requirement. This backport includes the fixes for the bootstrap error and the tests. libstdc++-v3/ChangeLog: PR libstdc++/118681 * src/c++17/memory_resource.cc (choose_block_size): New function. (synchronized_pool_resource::do_allocate): Use choose_block_size to determine appropriate block size. (synchronized_pool_resource::do_deallocate): Likewise (unsynchronized_pool_resource::do_allocate): Likewise. (unsynchronized_pool_resource::do_deallocate): Likewise * testsuite/20_util/synchronized_pool_resource/118681.cc: New test. * testsuite/20_util/unsynchronized_pool_resource/118681.cc: New test. Reviewed-by: Tomasz KamiÅski <tkami...@redhat.com> (cherry picked from commit ac2fb60a67d6d1de6446c25c5623b8a1389f4770)
