[Bug other/62095] New: gcc: error: unrecognized command line option

[dilyan.palauzov at aegee dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62095

            Bug ID: 62095
           Summary: gcc: error: unrecognized command line option
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dilyan.palauzov at aegee dot org

When I type
  gcc -WZ
I get
  gcc: error: unrecognized command line option ‘-WZ’
  gcc: fatal error: no input files
  compilation terminated.

But when I type
  gcc -Wno-Z
I get just
  gcc: fatal error: no input files
  compilation terminated.

I expect in the second case to see "unrecognized command line option "-Wno-Z"

Motivation:
  valgrind uncorrectly detects in configure.ac, if the compiler supports
-Wno-tautological-compare by running gcc -Wno-tautological-compare, which
prints no error => compiler supports -Wno-tautological-compare .  However,
during compiling valgrind, gcc manages to output somehow the message, that
"-Wno-tautological-compare " is not supported, but I cannot write a simple case
where gcc complains about -Wno-tautological-compare .