[Bug driver/94491] New: -g2 debugging level is not documented

["slyfox at inbox dot ru" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94491

            Bug ID: 94491
           Summary: -g2 debugging level is not documented
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: driver
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at inbox dot ru
  Target Milestone: ---

A tiny backstory: to profile a program I built it with '-g'. The result did not
fit in my RAM and machine crashed. Looking at the doc I found out '-g' means
'-g2' (and not '-g1').

Worth documenting what -g2 actually do? Others are interested as well:
https://stackoverflow.com/questions/10475040/gcc-g-vs-g3-gdb-flag-what-is-the-difference


'man gcc' covers only 0,1 and 3:

"""
       -glevel
       -ggdblevel
       -gstabslevel
       -gxcofflevel
       -gvmslevel
           Request debugging information and also use level to specify how much
information.  The default level is 2.

           Level 0 produces no debug information at all.  Thus, -g0 negates -g.

           Level 1 produces minimal information, enough for making backtraces
in parts of the program that you don't plan to debug.  This includes
descriptions of functions and external
           variables, and line number tables, but no information about local
variables.

           Level 3 includes extra information, such as all the macro
definitions present in the program.  Some debuggers support macro expansion
when you use -g3.

           If you use multiple -g options, with or without level numbers, the
last such option is the one that is effective.

           -gdwarf does not accept a concatenated debug level, to avoid
confusion with -gdwarf-level.  Instead use an additional -glevel option to
change the debug level for DWARF.
"""