[Python-Dev] what environment variable should contain compiler warning suppression flags?

Brett Cannon brett at python.org
Sun Jun 27 00:30:43 CEST 2010


On Wed, Jun 23, 2010 at 14:53, Brett Cannon <brett at python.org> wrote:
> I finally realized why clang has not been silencing its warnings about
> unused return values: I have -Wno-unused-value set in CFLAGS which
> comes before OPT (which defines -Wall) as set in PY_CFLAGS in
> Makefile.pre.in.
>
> I could obviously set OPT in my environment, but that would override
> the default OPT settings Python uses. I could put it in EXTRA_CFLAGS,
> but the README says that's for stuff that tweak binary compatibility.
>
> So basically what I am asking is what environment variable should I
> use? If CFLAGS is correct then does anyone have any issues if I change
> the order of things for PY_CFLAGS in the Makefile so that CFLAGS comes
> after OPT?
>

Since no one objected I swapped the order in r82259. In case anyone
else uses clang to compile Python, this means that -Wno-unused-value
will now work to silence the warning about unused return values that
is caused by some macros. Probably using -Wno-empty-body is also good
to avoid all the warnings triggered by the UCS4 macros in cjkcodecs.


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