Re: [PATCH] x86: avoid SORT_BY_INIT_PRIORITY with old GNU ld

[Jan Beulich <jbeulich@suse.com>]

On 07.03.2022 16:05, Roger Pau Monné wrote:
> On Mon, Mar 07, 2022 at 02:49:32PM +0100, Jan Beulich wrote:
>> Support for this construct was added in 2.22 only. Avoid the need to
>> introduce logic to probe for linker script capabilities by (ab)using the
>> probe for a command line option having appeared at about the same time.
>>
>> Fixes: 4b7fd8153ddf ("x86: fold sections in final binaries")
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> ---
>> Obviously this doesn't take care of old LLVM ld yet, if any care is
>> needed there in the first place.
>>
>> --- a/xen/arch/x86/arch.mk
>> +++ b/xen/arch/x86/arch.mk
>> @@ -70,6 +70,11 @@ ifeq ($(CONFIG_UBSAN),y)
>>  $(call cc-option-add,CFLAGS_UBSAN,CC,-fno-sanitize=alignment)
>>  endif
>>  
>> +# While not much better than going by raw GNU ld version, utilize that the
>> +# feature we're after has appeared in the same release as the
>> +# --print-output-format command line option.
>> +AFLAGS-$(call ld-option,--print-output-format) += -DHAVE_LD_SORT_BY_INIT_PRIORITY
> 
> LLVM ld doesn't have --print-output-format:
> 
> % ld --print-output-format
> ld: error: unknown argument '--print-output-format'
> 
> So it would be always defaulting to SORT. I'm not sure what to
> recommend.

Do you know if all versions we support know of SORT_BY_INIT_PRIORITY?

Jan