https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97599
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:7af5ea39232b04cb4a392cc869aaa7d66d9fabf8 commit r9-9393-g7af5ea39232b04cb4a392cc869aaa7d66d9fabf8 Author: Jakub Jelinek <ja...@redhat.com> Date: Sat Nov 14 09:14:19 2020 +0100 dwarf2: Emit DW_TAG_unspecified_parameters even in late DWARF [PR97599] Aldy's PR71855 fix avoided emitting multiple redundant DW_TAG_unspecified_parameters sub-DIEs of a single DIE by restricting it to early dwarf only. That unfortunately means if we need to emit another DIE for the function (whether it is for LTO, or e.g. because of IPA cloning), we don't emit DW_TAG_unspecified_parameters, it remains solely in the DW_AT_abstract_origin's referenced DIE. But DWARF consumers don't really use DW_TAG_unspecified_parameters from there, like we duplicate DW_TAG_formal_parameter sub-DIEs even in the clones because either they have some more specific location, or e.g. a function clone could have fewer or different argument types etc., they need to assume that originally stdarg function isn't later stdarg etc. Unfortunately, while for DW_TAG_formal_parameter sub-DIEs, we can use the hash tabs to look the PARM_DECLs if we already have the DIEs, for DW_TAG_unspecified_parameters we don't have an easy way to look it up. The following patch handles it by trying to figure out if we are creating a fresh new DIE (in that case we add DW_TAG_unspecified_parameters if it is stdarg), or if gen_subprogram_die is called again on an pre-existing DIE to fill in some further details (then it will not touch it). Except for lto, subr_die != old_die would be good enough, but unfortunately for LTO the new DIE that will refer to early dwarf created DIE is created on the fly during lookup_decl_die. So the patch tracks if the DIE has no children before any children are added to it. 2020-11-14 Jakub Jelinek <ja...@redhat.com> PR debug/97599 * dwarf2out.c (gen_subprogram_die): Call gen_unspecified_parameters_die even if not early dwarf, but only if subr_die is a newly created DIE. (cherry picked from commit 812258b07c1a80e8dc79a0beb3ec0e17be62f5e5)
