[PATCH v2 2/2] Enable arch-specific CFI directives and DWARF instructions only when required by the target (part 1)

[Jan Beulich]

On 25.04.2025 16:02, Matthieu Longo wrote:
> On 2025-04-25 14:10, Jan Beulich wrote:
>> On 25.04.2025 13:04, Matthieu Longo wrote:
>>> --- a/gas/dw2gencfi.c
>>> +++ b/gas/dw2gencfi.c
>>> @@ -720,9 +720,16 @@ const pseudo_typeS cfi_pseudo_table[] =
>>>       { "cfi_same_value", dot_cfi, DW_CFA_same_value },
>>>       { "cfi_remember_state", dot_cfi, DW_CFA_remember_state },
>>>       { "cfi_restore_state", dot_cfi, DW_CFA_restore_state },
>>> -    { "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save },
>>> +#if TC_AARCH64
>>> +    /* cfi_window_save is an alias of cfi_negate_ra_state which is kept for
>>> +       backward-compatibility concerns.  */
>>> +    { "cfi_window_save", dot_cfi, DW_CFA_AARCH64_negate_ra_state },
>>
>> Why's this of concern only for Arm64?
> 
> I am not sure that I understand what your question is here.
> cfi_window_save is only used by AArch64 and Sparc.

Arm64 uses .cfi_negate_ra_state. .cfi_window_save was wrongly exposed
everywhere except for Sparc. Hence as I view it either all other
architectures need to retain it for backwards compatibility, or none
of them. Yet perhaps I'm missing some peculiarity here.

Jan