https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126841
--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Longjun Luo <[email protected]>: https://gcc.gnu.org/g:543617c93595e0cb45ff7ee52c635ca30a2fe361 commit r17-4380-g543617c93595e0cb45ff7ee52c635ca30a2fe361 Author: Longjun Luo <[email protected]> Date: Thu Sep 17 03:02:05 2026 +0000 middle-end: Defer section resolution for GIMPLE wrappers [PR126841] Since r167795, cfgexpand has resolved a function's section before RTL expansion. r168624 added resolve_unique_section to the direct thunk emission path, when thunks were still emitted directly as assembly. When r202592 added a GIMPLE thunk path, the call was retained in both paths. The direct assembler path still needs it, but the GIMPLE path later reaches cfgexpand, so its call is redundant. It can also be too early. IPA ICF can turn equivalent functions whose addresses matter into GIMPLE wrappers during WPA, before LTO privatizes their assembler names. The early call records a section based on the old name, and that stale section is streamed into LTRANS. IPA strub has the same problem in the GIMPLE wrapper code added in r14-6201. Remove the early calls for GIMPLE wrappers and let cfgexpand resolve their sections from the final assembler names. Keep the call for directly emitted assembler thunks; during LTO output it is reached only after privatization. Explicit and deliberately inherited section names remain unchanged. This fixes the stale name at its source instead of discarding an already-resolved section only when LTO privatizes a symbol. PR lto/126841 gcc/ChangeLog: * doc/invoke.texi (-ffunction-sections): Document implicit function section names under LTO. * ipa-strub.cc (pass_ipa_strub::execute): Let cfgexpand resolve the GIMPLE wrapper section. * symtab-thunks.cc (expand_thunk): Likewise for generic GIMPLE thunks. Clarify the direct-assembler case. gcc/testsuite/ChangeLog: * gcc.dg/lto/pr126841-strub_0.c: New test. * gcc.dg/lto/pr126841-strub_1.c: New test. * gcc.dg/lto/pr126841_0.c: New test. * gcc.dg/lto/pr126841_1.c: New test. * gcc.dg/lto/pr126841_2.c: New test. * gcc.dg/lto/pr126841_3.c: New test. Signed-off-by: Longjun Luo <[email protected]>
