[PATCH v8 02/19] gas: move code for object attribute parsing into obj-elf-attr.c

[Matthieu Longo]

On 2025-07-31 14:14, Jan Beulich wrote:
> On 15.07.2025 13:39, Matthieu Longo wrote:
>> --- a/gas/configure.ac
>> +++ b/gas/configure.ac
>> @@ -454,6 +454,19 @@ changequote([,])dnl
>>   	;;
>>       esac
>>   
>> +    # Does the target support Object Attributes ?
>> +    case ${cpu_type} in
>> +      arc* | arm* | csky | m68k | mips* | msp430 | powerpc* \
>> +      | riscv* | s390* | sparc* | tic6x)
>> +	for f in config/obj-elf-attr.o; do
>> +	  case " $extra_objects " in
>> +	    *" $f "*) ;;
>> +	    *) extra_objects="$extra_objects $f" ;;
>> +	  esac
>> +	done
>> +	;;
>> +    esac
>> +
>>       # Any other special object files needed ?
>>       case ${cpu_type} in
> 
> Looking at patch 04 I came to wonder: How does this limit addition of the
> extra object file to ELF targets?
> 
> Jan

The code in the C file is surrounded by TC_OBJ_ATTR that is not set for 
targets without no support for object attributes like x86_64. The change 
in gas/configure.ac ensures that the file is not built.

After patch 4,
- for targets with no support for OA, nothing change. obj-elf-attr.c is 
still not built.
- for targets supporting only OAv1, the file is included, TC_OBJ_ATTR is 
set but only TC_OBJ_ATTR_v1 is set. So any OAv2-only code is disabled 
and won't be compiled.
- for targets supporting only OAv2, same thing but TC_OBJ_ATTR_v2 is set 
instead of TC_OBJ_ATTR_v1.
- if any target decides to migrate to OAv2, they can enable both OAv1 
and OAv2 to support both for a transition period.

The addition of the extra object file will always happen when the target 
supports OA. From my perspective, I don't see much benefit of splitting 
OAv1 and OAv2 code in three different files (one for the generic code, 
and the others two for OAv1 and OAv2). The quantity of code seemed too 
small to do so.

Since the result is the same after compilation, it seems that your 
concern is more related to code organization. Please let me know what is 
your concern.

Matthieu