[cfe-dev] [LLVMdev] Integrated ARM assembler

[Greg Fitzgerald]

> Hum, that's bad and should be fixed. Can you create a bug, pls?

Done. http://llvm.org/bugs/show_bug.cgi?id=15172


> In that case, using GAS is always a better options... for now. ;)

I think we are very close to fully supporting inline ARM assembly, no?
 Just need to parse those few ELF-specific directives?


> The main problem with this is that in a large project, with different
flags, some files
> will be compiled with integrated-as, others with GAS, and this could also
change
> in time, creating a good headache for many people. ;)

So I think our options are:

1) warn & use GAS if option is missing.  Renato gives -1.
2) warn that we are ignoring these unsupported options.
3) block integrated-as default until GAS options are implemented.
4) turn on integrated-as by default, leave the error, and expect users to
workaround.  Greg gives -1.

-Greg



On Tue, Feb 5, 2013 at 3:48 PM, Renato Golin <renato.golin at linaro.org>wrote:

> On 5 February 2013 23:21, Greg Fitzgerald <garious at gmail.com> wrote:
>
>> > Is this for inline asm?
>>
>> Yep
>>
>
> In that case, using GAS is always a better options... for now. ;)
>
>
> What I'd prefer to see is if the integrated-as doesn't recognize the
>> option, clang should report a warning and switch to the 'no-integrated-as'
>> path.  Thoughts?
>>
>
> The main problem with this is that in a large project, with different
> flags, some files will be compiled with integrated-as, others with GAS, and
> this could also change in time, creating a good headache for many people. ;)
>
>
> I agree that's the more important question, but shouldn't we be able to
>> throw hand-written assembly files at clang too?
>>
>
> Of course we should, but as long as it's hidden behind a flag, it'll never
> be properly tested and people will never fix the bugs...
>
>
> $ echo "void a(){}" | clang -x c -S - -o - | clang -x assembler -c -
>> -integrated-as
>> <stdin>:2:2: error: unknown directive
>> .eabi_attribute 6, 2
>>
>
> Hum, that's bad and should be fixed. Can you create a bug, pls?
>
>
> I agree, but if you do it today, some builds will certainly choke at
>> compile-time.  Chromium serves as a nice big workload that currently builds
>> with a very recent version of Clang.  As is, that build will go down if you
>> switched the default on them.
>>
>
> I think this is a concern. Not everyone can change to recent versions of
> clang as soon as they come out, but as long as the problems are just
> warnings, I think we can risk a bit more exposure.
>
> Can you compile Chromium entirely, ignoring the warnings and hand-written
> ASM, with integrated-as, for ARM?
>
> In your project configuration, you could add "-no-integrated-as" for the
> parts that do have inline ASM.
>
> cheers,
> --renato
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20130205/c27b9621/attachment.html>