https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91596
Bug ID: 91596
Summary: IPA cdtor merging should preserve link file ordering
Product: gcc
Version: 9.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: rguenth at gcc dot gnu.org
CC: marxin at gcc dot gnu.org
Target Milestone: ---
See https://bugzilla.suse.com/show_bug.cgi?id=1148217 where using -flto changes
the order of global ctor invocations, breaking programs relying on (undefined)
order of executing them for different TUs (and likely being lucky with link
file order).
IMHO using -flto should not change the order of ctor/dtor invocations and thus
should preserve linker behavior (which we simply assume concatenating in
linker argument order or reverse which we could expose via a flag or try
to detect at configure time).
ipa_cdtor_merge via compare_dtor sorts after DECL_{INIT,FINI}_PRIORITY
and then after DECL_UID where the latter should be changed to first
order after the command-line order of files the definitions come from.
