[PATCH v9 04/19] gas: implement parsing of object attributes v2

[Jan Beulich]

On 20.11.2025 16:08, Matthieu Longo wrote:
> On  06/11/2025 17:05, Jan Beulich wrote:
>>>>> +  return true;
>>>>> +}
>>>>> +#endif /* TC_OBJ_ATTR_v2 */
>>>>> +
>>>>> +#if (TC_OBJ_ATTR_v1)
>>>>> +/* Look up attribute tags defined in the backend (object attribute v1).  */
>>>>> +static bool
>>>>> +obj_attr_v1_lookup_known_attr_tag_symbol (const char *identifier,
>>>>> +					  arg_token_t token_type,
>>>>> +					  arg_t *val_out)
>>>>> +{
>>>>> +#ifndef CONVERT_SYMBOLIC_ATTRIBUTE
>>>>> +#define CONVERT_SYMBOLIC_ATTRIBUTE(a) -1
>>>>> +  (void) identifier;
>>>> As indicated in v8 review - the common way is use of ATTRIBUTE_UNUSED.
>>> Fixed but unsure about the formatting (see below).
>>>
>>> diff --git a/gas/config/obj-elf-attr.c b/gas/config/obj-elf-attr.c
>>> index 82ec6a79783..b574d46b80c 100644
>>> --- a/gas/config/obj-elf-attr.c
>>> +++ b/gas/config/obj-elf-attr.c
>>> @@ -354,15 +354,16 @@ resolve_if_matching (const char *identifier,
>>>    #if (TC_OBJ_ATTR_v1)
>>>    /* Look up attribute tags defined in the backend (object attribute
>>> v1).  */
>>>    static bool
>>> -obj_attr_v1_lookup_known_attr_tag_symbol (const char *identifier,
>>> -                                         arg_token_t token_type,
>>> -                                         arg_t *val_out)
>>> -{
>>> +obj_attr_v1_lookup_known_attr_tag_symbol (
>>>    #ifndef CONVERT_SYMBOLIC_ATTRIBUTE
>>> -#define CONVERT_SYMBOLIC_ATTRIBUTE(a) -1
>>> -  (void) identifier;
>>> +  #define CONVERT_SYMBOLIC_ATTRIBUTE(a) -1
>>> +  const char *identifier ATTRIBUTE_UNUSED,
>>> +#else
>>> +  const char *identifier,
>> Well, no. See other uses of ATTRIBUTE_UNUSED: It's applied if any build
>> configuration would leave a parameter unused. No #ifdef-ary like this.
> 
> If you absolutely want me to not use ATTRIBUTE_UNUSED in this case, how am I supposed to do for targets that don't define CONVERT_SYMBOLIC_ATTRIBUTE like m68k ?
Perhaps a misunderstanding? I don't mind the ATTRIBUTE_UNUSED; what I do mind is the
#ifdef-ary trying to avoid its use in certain configurations. What I was trying to
point out is that elsewhere, if in _some_ configuration an item is unused, it'll
have the attribute applied, even if in other configurations it is used.
read.c:s_mri_sect() and read.c:do_parse_cons_expression() may be good examples for
you to look at.

Jan