Re: [PATCH dwarves 0/2] dwarf_loader: improve cus__merging_cu()

[Bill Wendling <morbo@google.com>]

On Wed, Mar 31, 2021 at 7:58 PM Yonghong Song <yhs@fb.com> wrote:
>
> Function cus__merging_cu() is introduced in Commit 39227909db3c
> ("dwarf_loader: Permit merging all DWARF CU's for clang LTO built
> binary") to test whether cross-cu references may happen.
> The original implementation anticipates compilation flags
> in dwarf, but later some concerns about binary size surfaced
> and the decision is to scan .debug_abbrev as a faster way
> to check cross-cu references. Also putting a note in vmlinux
> to indicate whether lto is enabled for built or not can
> provide a much faster way.
>
> This patch set implemented this two approaches, first
> checking the note (in Patch #2), if not found, then
> check .debug_abbrev (in Patch #1).
>
> Yonghong Song (2):
>   dwarf_loader: check .debug_abbrev for cross-cu references
>   dwarf_loader: check .notes section for lto build info
>
>  dwarf_loader.c | 76 ++++++++++++++++++++++++++++++++++++--------------
>  1 file changed, 55 insertions(+), 21 deletions(-)
>
With this series of patches, the compilation passes for me with
ThinLTO. You may add this if you like:

Tested-by: Bill Wendling <morbo@google.com>

Thanks!
-bw