[vlc-devel] [PATCH] contrib: disable thumb for packages that use ARM-only asm

[Rafaël Carré]

Le 2012-01-24 02:51, Rémi Denis-Courmont a écrit :
> On Tue, 24 Jan 2012 02:34:06 -0500, Rafaël Carré <funman at videolan.org>
> wrote:
>> Le 2012-01-24 02:07, Rémi Denis-Courmont a écrit :
>>> On Tue, 24 Jan 2012 02:06:07 -0500, Rafaël Carré <funman at videolan.org>
>>> wrote:
>>>> Le 2012-01-24 02:02, Rémi Denis-Courmont a écrit :
>>>>> This will not work if AAPCS is not in use (and if interworking is not
>>>>> otherwise forced system-wide).
>>>>
>>>> I assume people using thumb knows what to do.
>>>
>>> I don't. Precisely if you optimize code for size, you might not want to
>>> support interworking.
>>
>> Currently I can build contribs with -mthumb (obviously skipping faad,
>> mad, speex and tremor), and vlc with -marm and linking will probably not
>> complain but VLC will still crash at runtime.
> 
> Yeah. That is why ARM/Thumb selection belongs in the toolchain defaults or
> OS-specific build tools, not in the VLC build system(s). float-abi is
> another one similar case.
> Basically, anything compiler parameter that affects the ABI, on ARM or any
> other architecture, should be set at the system-wide level. And the VLC
> build system(s) should leave those as is.

I use export CFLAGS=-mthumb\ -mthumb-interwork or similar (so it is
system-level)

> 
> IMHO, if some piece of code, typically assembler, has specific
> requirements, it should deal with them locally.

Porting assembler code is no easy task (though perhaps thumb2 is simpler
than thumb).

In the meantime, that patch helps.