Re: [PATCH] Remove fno-unit-at-a-time make variable

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 05/04/2022 18:15, Adhemerval Zanella wrote:
> 
> 
> On 05/04/2022 17:40, Florian Weimer wrote:
>> * Adhemerval Zanella:
>>
>>> On 05/04/2022 17:26, Florian Weimer wrote:
>>>> * Adhemerval Zanella:
>>>>
>>>>> On 05/04/2022 14:53, Florian Weimer wrote:
>>>>>> * Adhemerval Zanella via Libc-alpha:
>>>>>>
>>>>>>> This is not what I am seeing on my clang branch, where clang with integrated
>>>>>>> moves the global asm directives to the top of the file.  And it makes 
>>>>>>> check-abi fail due the _sys_errlist/sys_errlist being with wrong value.
>>>>>>
>>>>>> You can move the directives to the bottom of the file by creating a
>>>>>> temporary .s file and #include that from a wrapper .S file that
>>>>>> #includes the .s file.
>>>>>
>>>>> Not sure I am following your suggestion here, do you mean get the -S
>>>>> output file from compiler?
>>>>
>>>> Yes, H.J. did that in earlier patches.  But I didn't like it back then. 8-p
>>>
>>> For dl-debug-symbols.S? I might take it as an example.
>>
>> Yes, here's a link to one of the earlier patches:
>>
>>   [PATCH] Extend struct r_debug to support multiple namespaces
>>   <https://sourceware.org/pipermail/libc-alpha/2021-August/130149.html>
> 
> Thanks, I found it on the my local inbox history.
> 
>>
>> In the end, I think it was easier to use a manually written assembler
>> file in that case, with the constants filled in via the .sym expander.
> 
> I think for this case, it would be simpler to use H.J strategy, I really
> don't want to re-implement what compiler might do to lay out a C array
> to assembler.

And so it seems it does not really help clang, the integrated assembler
still reorganizes the global asm directives which breaks the required
ABI size directives.