[PATCH 1/3] gas: sframe: guard block with support_sframe_p

[Indu Bhagat]

On 7/6/25 11:19 PM, Jan Beulich wrote:
> On 07.07.2025 08:10, Indu Bhagat via Binutils wrote:
>> SFrame is generated for ELF targets only.  Guard the block with
>> support_sframe_p like others for consistency.
> 
> The block was guarded already, just not ...
> 
>> @@ -2606,6 +2601,7 @@ cfi_finish (void)
>>   	- .sframe in the .cfi_sections directive.  */
>>     if (flag_gen_sframe || (all_cfi_sections & CFI_EMIT_sframe) != 0)
>>       {
>> +#ifdef support_sframe_p
> 
> ... by a pre-processor conditional, just ...
> 
>>         if (support_sframe_p () && !SUPPORT_FRAME_LINKONCE)
> 
> ... the invocation (plus the stub that you now remove). Hence the
> description doesn't really make clear what the problem as and why a
> change would be needed.
> 

In a later commit, we would like to do a:
   elf_section_type (sframe_seg) = SHT_GNU_SFRAME;

This cannot be done for non-ELF targets, hence the need to guard with 
some pre-processor conditional to enable it for only OBJ_ELF.  Guarding 
with support_sframe_p works for now, because those targets that support 
SFrame define support_sframe_p:
   - x86_64 and aarch64 define support_sframe_p when OBJ_ELF is defined
   - s390x has no non-LEF target.

The other option (B) is to be explicit and say
#if defined(support_sframe_p) && defined(OBJ_ELF)

Also, we can absolutely just use (option C):

#ifdef OBJ_ELF
   if (support_sframe_p ()...)
   {
     ...
   }
   else
#endif

the last one  (option C) has to to be with the initial definition in place:
/* Targets which support SFrame format will define this and return true.  */
#ifndef support_sframe_p
# define support_sframe_p() false
#endif