[Bug debug/113000] New: Generate BTF always in early-finish regardless of CO-RE

[Bug debug/113000] New: Generate BTF always in early-finish regardless of CO-RE

[jemarch at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113000

            Bug ID: 113000
           Summary: Generate BTF always in early-finish regardless of
                    CO-RE
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jemarch at gcc dot gnu.org
  Target Milestone: ---

The BPF CO-RE support requires storing information relevant to the BTF debug
info in the .BTF.ext section.  In particular:

 * The CO-RE relocation strings contain references to BTF types, by type ID.
 * The CO-RE information includes strings that are stored in the BTF string
section.

Because of the above, we are generating BTF (call to ctf_debug_finish) in
dwarf2out's early_finish if no -mco-re is specified, but the call is done in
dwarf2out's finish instead if -mco-re is specified.  This implies that there
are differences in the output (also in CTF) because for example entries for
inlined functions are no longer present at 'finish' time but they are at
'early_finish' time.

We should change GCC so it always calls ctf_debug_finish in early_finish,
regardless of whether CO-RE relocs are being generated or not.

[Bug debug/113000] Generate BTF always in early-finish regardless of CO-RE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113000

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note you then need a way to cope with LTO.