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
