[Bug other/31351] New: gcc -v --help has poor documentation for some shared Ada/C options

["brooks at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

When an option is shared between multiple front ends, the output of gcc -v
--help uses the documentation string from the first front end for which it is
listed.

Ada is listed before C, and thus all of the shared Ada/C options use the Ada
documentation, rather than the C documentation.  Unfortunately, the Ada
lang.opt file doesn't have good documentation for some of these:

---------------------------------------
The Ada front end recognizes the following options:

  -I                          This switch lacks documentation
  -Wall                       This switch lacks documentation
  -Wlong-long                 Do not warn about using "long long" when
-pedantic
  -Wmissing-format-attribute  Warn about functions which might be candidates
                              for format attributes
  -Wmissing-prototypes        Warn about global functions without prototypes
  -Wold-style-definition      Warn if an old-style parameter definition is used
  -Wstrict-prototypes         Warn about unprototyped function declarations
  -Wvariadic-macros           Do not warn about using variadic macros when
                              -pedantic
  -Wwrite-strings             In C++, nonzero means warn about deprecated
                              conversion from string literals to `char *'.  In
                              C, similar warning, except that the conversion is
                              of course not deprecated by the ISO C standard.
  -fRTS=                      This switch lacks documentation
  -gnat<options>              Specify options to GNAT
  -gnatO                      This switch lacks documentation
  -nostdinc                   Do not search standard system include directories
                              (those specified with -isystem will still be
used)
  -nostdlib                   This switch lacks documentation
---------------------------------------

My personal opinion is that this would really be best fixed by listing C and
C++ first in the --help output, since they're much more commonly used. 
However, a workaround would be copying the C documentation to the Ada lang.opt
file.


-- 
           Summary: gcc -v --help has poor documentation for some shared
                    Ada/C options
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: brooks at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31351