[Qemu-devel] Re: [PATCH] configure: fix breakage of --extra-{cflags, ldflags}

[Jan Kiszka <jan.kiszka@siemens.com>]

Juan Quintela wrote:
> Nathan Froyd <froydnj@codesourcery.com> wrote:
>> On Thu, Jul 23, 2009 at 02:43:26PM +0200, Juan Quintela wrote:
>>> Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>>>> -CFLAGS="$CFLAGS -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls"
>>>>> -LDFLAGS="$LDFLAGS -g"
>>>>> +CFLAGS="$CFLAGS $EXTRA_CFLAGS -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls"
>>>>> +LDFLAGS="$LDFLAGS $EXTRA_LDFLAGS -g"
>>>> ...but now we add the extra flags twice. So please remove the injection
>>>> into the flags for $config_mak.
>>> It is still broken.  Thinking of a solution.
>>> People wanted EXTRA_CFLAGS to be added at the end of CFLAGS, not in the
>>> middle.  Trying to find a way that is consistent for everything.
>>>
>>> Could you told in what test do you need extra_cflags?
>> The particular instance was for detecting zlib in a cross
>> configuration.  But that's not necessarily the only test where
>> --extra-{cflags,ldflags} would be useful: every test that needs external
>> libraries is subject to this bug (zlib, TLS, SASL, SDL, VDE libraries,
>> BrlAPI?, Xen?, bluez?, etc.).
>>
>> If adding EXTRA_{CFLAGS,LDFLAGS} to all such tests is necessary and
>> people feel that's the best solution, then I can do that.
> 
> I think that the solution is the other way around :)
> 
> call configure with:
> 
> CFLAGS="foo bar" ./configure
> 
> and use CFLAGS for all configure script
> 
> That was what I had in mind.
> 
> If we do always in configure:
> 
> CFLAGS="baz goo $CFLAGS"
> 
> We also maintain the propierte that whatever you pass to CFLAGS is the
> last option in CFLAG (i.e. can overwrote whatever found by configure.
> 
> Then we can:
> - kill extra cflags,
> - win your feature,
> -  and have user wrote at the end of CFLAGS variable
> 
> What do you think?

No concerns. My only additional requirement is that configure should not
forget about the provided CFLAGS when going through automatic reconfig,
just like it's currently the case with --extra-* - and like autoconf
behaves, too.

Jan

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