[Xenomai-core] Compiler and linker flags (was: Please remove "-I." in "xeno-config --*-cflags)

[Jan Kiszka <jan.kiszka@domain.hid>]

[-- Attachment #1: Type: text/plain, Size: 2520 bytes --]

Thomas Wiedemann wrote:
>> BTW, providing a patch, even if it's trivial, is always welcome in such
>> cases.
> 
> I had already attached it to the email, but then i thought it was so
> ridiculously small ... and removed it :)
> So here it is again.

The point is if you start a thread like "[PATCH] Remove -I. from
xeno-config" and attach a full patch (including ChangeLog fragment) you
make it more likely to gain full attention and help to get it applied
quickly.

> 
>  
>> Well, -Wall should be considered a reasonable policy to keep code clean.
>> Me feeling is that this switch is fairly appropriate, specifically for
>> real-time applications. But it can easily be relaxed by adding specific
>> -Wno-xxx after the Xenomai flags. And *that* should happen explicitly.
>>
>> -pipe is an optimisation of the build process, something one may
>> discuss, though I don't see an immediate reason why it could fail in the
>> context of Xenomai applications (that should use the GNU toolchain 
> anyway).
> 
> I definitley agree on the use of "-Wall" and "-pipe", but i think these
> optional flags should be set in the main project, and not by external
> libraries or tools. It's not that i think they would conflict with
> other flags or that they are wrong or inappropriate, but just because
> i expect *-config-tools to not specify any flags that affect the
> compiler behaviour. I just don't want every libraries' config-script
> to place the authors favorite compiler-flags into my own flags.

I agree now, for the sake of cleanness and as we are not just discussing
-Wall and -pipe here:

# xeno-config --xeno-cflags
-I. -I<xenomai-inst>/include -O2 -D_GNU_SOURCE -D_REENTRANT -D__XENO__
-Wall -pipe -fstrict-aliasing -Wno-strict-aliasing

# xeno-config --posix-cflags
-I. -I<xenomai-inst>/include -I<xenomai-inst>/include/posix -O2
-D_GNU_SOURCE -D_REENTRANT -D__XENO__ -Wall -pipe -fstrict-aliasing
-Wno-strict-aliasing

# xeno-config --xeno-ldflags
-L<xenomai-inst>/lib -lpthread -rdynamic

# xeno-config --posix-ldflags
-Wl,@<xenomai-inst>/lib/posix.wrappers -L<xenomai-inst>/lib -lpthread_rt
-lpthread -lrt -rdynamic

(all x86, other platforms may vary)

@All: What flags are *really* required to build and link some *user*
application against Xenomai? Beside that -I. at least -O2 can be fairly
problematic I guess - if not even more. Also the debug mode of the
Xenomai build leaks to the user if (s)he wants it or not.

Time for a cleanup?

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 249 bytes --]