[Bug bootstrap/50758] [4.7 Regression] Bootstrap fails at stage 2 on x86_64-apple-darwin10: error: variable 'token_no' set but not used

[dodji at seketeli dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50758

--- Comment #5 from dodji at seketeli dot org <dodji at seketeli dot org> 2011-10-17 15:56:05 UTC ---
"dominiq at lps dot ens.fr" <gcc-bugzilla@gcc.gnu.org> a écrit:

> I guess that revision 180090 is a similar fix that should work (I'll
> have the answer in a couple hours;-).

OK, thanks.

> Last question: is the warning bogus or not? If no, why? If yes, I'll
> open a new PR.

The warning is not bogus when you are compiling with --disable-checking
or when your GCC_VERSION is < 2007.  This is because the way
linemap_assert is defined:

    /* Assertion macro to be used in line-map code.  */
    #define linemap_assert(EXPR)            \
      do {                        \
        if (! (EXPR))                \
          abort ();                    \
      } while (0)

    /* Assert that MAP encodes locations of tokens that are not part of
       the replacement-list of a macro expansion.  */
    #define linemap_check_ordinary(LINE_MAP) __extension__        \
      ({linemap_assert (!linemap_macro_expansion_map_p (LINE_MAP)); \
        (LINE_MAP);})
    #else
    #define linemap_assert(EXPR)
    #define linemap_check_ordinary(LINE_MAP) (LINE_MAP)
    #endif

In those cases token_no is not used.  Hence the fix committed to
revision 180090.

Sorry for the inconvenience.