[Bug driver/101383] GCC 11 Reproducibility Issue

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101383

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aoliva at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
          Component|debug                       |driver
   Last reconfirmed|                            |2021-07-09
     Ever confirmed|0                           |1

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
I can for example trigger it with

gcc -c t.c -Wa,--gdwarf-5

or also

gcc -c t.c -g -gtoggle

where despite treating -g -gtoggle as -g0 we still end up passing --gdwarf-5 to
the assembler.  So this way will cause different stage2 checksum (since
stage2 is built with -g -gtoggle) and that's re-used for stage3 and thus
causes the difference (in just the checksum).

It looks like debug-level-gt is not affected by -gtoggle
(gcc.c:debug_level_greater_than_spec_func) or too late for the driver to
notice.
In fact it seems to be handled in the compiler only (process_options).