http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60287
Tobias Burnus <burnus at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |burnus at gcc dot gnu.org
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Chengnian Sun from comment #0)
> 1) Besides "-Wformat=2", gcc accepts any option in the form of
> -Wformat=<number>
> Based on the manual, gcc only accepts "-Wformat=2", and others such as
> "-Wformat=0,1, 3-9" should be invalid. Any undocumented behavior?
Well, -Wformat=0 disables all format warnings (not really documented) - and
should be equivalent to -Wno-format; "-Wformat=1" is equivalent to "-Wformat" -
and that is explicitly documented in the manual:
http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wformat-294
And -Wformat=2 is equivalent to -Wformat=1 plus additional warnings.
-Wformat=3 would be equivalent to -Wformat=2 plus additional (nonexisting)
options. And I think it currently acts as -Wformat=2, which should be fine as
well.
(Similar is: -O0, -O1, -O2, -O3; where some other compilers have -O4 - but GCC
doesn't and [I think it] treats it as -O3.)
> 2) Is the warning name "[-Wformat=]" in the warning message intended?
Yes - as one doesn't want to distinguish between "-Wformat=2" and
"-Wformat/-Wformat=1 -Wformat-security". In particular, "-Wformat-security"
requires "-Wformat=1" in addition, otherwise, it doesn't warn at all.
Thus, printing [-Wformat=] is way easier than to re-construct the exact option.
> 3) Is the column number information correct in the warning message? Should
> the warning refer to the location of the problematic argument, or the
> function call?
Well, the column number is correct - but pointing to either to the proper '%'
in the format string or to the argument would be better. - Like always, there
is room for improvement.
