Re: [PATCH v2 1/2] GDB: aarch64-linux: Reorganize gdb/arch/aarch64-gcs-linux.h

[Simon Marchi <simark@simark.ca>]

On 2026-02-17 00:10, Thiago Jung Bauermann wrote:
> Simon Marchi <simark@simark.ca> writes:
> 
>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
>>> index 028de981588b..b2dd192a7b56 100644
>>> --- a/gdb/aarch64-linux-nat.c
>>> +++ b/gdb/aarch64-linux-nat.c
>>> @@ -51,7 +51,7 @@
>>>  #include "gdb_proc_service.h"
>>>  #include "arch-utils.h"
>>>  
>>> -#include "arch/aarch64-gcs-linux.h"
>>> +#include "arch/aarch64-linux.h"
>>>  #include "arch/aarch64-mte-linux.h"
>>>  
>>>  #include "nat/aarch64-mte-linux-ptrace.h"
>>> @@ -1013,7 +1013,7 @@ aarch64_linux_nat_target::read_description ()
>>>       active or not.  */
>>>    features.vq = aarch64_sve_get_vq (tid);
>>>    features.pauth = hwcap & AARCH64_HWCAP_PACA;
>>> -  features.gcs = features.gcs_linux = hwcap & HWCAP_GCS;
>>
>> This one could stay HWCAP_GCS, but I don't have a preference.
> 
> Luis prefers keeping it as HWCAP_GCS (and also renaming
> AARCH64_HWCAP_PACA to HWCAP_PACA), so that's what I'm doing for v3.
> 
>> If we want to ensure / prove they are the same, we could add asserts
>> like this in the nat/ header:
>>
>>   static_assert (AARCH64_HWCAP_GCS == HWCAP_GCS);
>>
>> That assert would only be checked when compiling natively for an aarch64
>> system (where HWCAP_GCS is available), but it's better than nothing.
> 
> I mentioned this concern mostly for completeness, TBH. IMO it's not
> worth adding this assert unless we're actually bitten by this problem
> (which AFAIK hasn't happened yet).

I wouldn't expect it to really catch mistakes, it would be more for
self-documentation.

Simon