On 05/02/2026 15:30, Matthieu Longo wrote:
> On 05/02/2026 15:02, Richard Earnshaw (foss) wrote:
>> On 30/01/2026 16:55, Matthieu Longo wrote:
>>> When branch protections are enabled (see -mbranch-protection), GCC tags
>>> the output object file with metadata describing which security features
>>> are used, allowing the GNU linker to detect incompatibilities between
>>> objects in the same link unit.
>>>
>>> Originally, this metadata was conveyed via GNU properties. GCC emitted a
>>> .note.gnu.property section containing a GNU_PROPERTY_AARCH64_FEATURE_1_AND
>>> entry.
>>> Build Attributes v2 (OAv2) aim at replacing GNU properties, provinding
>>> a more flexible way to express complex metadata and making easier for
>>> tools like linkers to parse them.
>>>
>>> Since the runtime linker only understands GNU properties, the GNU static
>>> linker translates OAv2 attributes into GNU properties. As a result,
>>> emitting both GNU properties and OAv2 in the same object file is redundant.
>>> When GCC detects OAv2 support in GNU binutils, it therefore emits only
>>> OAv2 directives.
>>>
>>> Support for OAv2 was added in [1], along with new tests covering both
>>> the emission/omission of GNU properties/OAv2 directives. However, an older
>>> BTI test that checked for the presence of a GNU properties section was
>>> left unchanged. This test now fails when GNU binutils support OAv2, as no
>>> GNU properties are emitted.
>>>
>>> This patch removes the expectations of the presence of GNU properties from
>>> that BTI test.
>>>
>>> [1]: 98f5547dce2503d9d0f0cd454184d6870a315538
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> * gcc.target/aarch64/bti-1.c: Update.
>>> ---
>>> gcc/testsuite/gcc.target/aarch64/bti-1.c | 2 --
>>> 1 file changed, 2 deletions(-)
>>>
>>> diff --git a/gcc/testsuite/gcc.target/aarch64/bti-1.c
>>> b/gcc/testsuite/gcc.target/aarch64/bti-1.c
>>> index 53dc2d3cd8b..174b62eb05b 100644
>>> --- a/gcc/testsuite/gcc.target/aarch64/bti-1.c
>>> +++ b/gcc/testsuite/gcc.target/aarch64/bti-1.c
>>> @@ -61,5 +61,3 @@ lab2:
>>> }
>>> /* { dg-final { scan-assembler-times "hint\t34 // bti c" 1 } } */
>>> /* { dg-final { scan-assembler-times "hint\t36 // bti j" 12 } } */
>>> -/* { dg-final { scan-assembler "\.section\t\.note\.gnu\.property" { target
>>> *-*-linux* } } } */
>>> -/* { dg-final { scan-assembler "\.word\t0x7\t\/\/
>>> GNU_PROPERTY_AARCH64_FEATURE_1_AND \\(BTI, PAC, GCS\\)" { target *-*-linux*
>>> } } } */
>>
>> Wouldn't it be better to qualify the test for when the assembler lacks this,
>> something like
>> ... { target { *-*-linux* && aarch64_gas_has_build_attributes } } } } */
>>
>
> Not really, because this test is redundant now with the following tests:
> gcc/testsuite/gcc.target/aarch64/build-attributes/no-build-attribute-bti.c
> gcc/testsuite/gcc.target/aarch64/build-attributes/no-build-attribute-gcs.c
> gcc/testsuite/gcc.target/aarch64/build-attributes/no-build-attribute-pac.c
>
> gcc/testsuite/gcc.target/aarch64/build-attributes/no-build-attribute-standard.c
>
> This part in the commit description was supposed to clarify this point.
> > Support for OAv2 was added in [1], along with new tests covering both
> > the emission/omission of GNU properties/OAv2 directives.
>
> To keep things simple and coherent (otherwise, why don't GCS tests also test
> for GCS tag ? or PAC tests PAC tag ?), it seems to me that it is better to
> remove the check.
>
>>> \ No newline at end of file
>>
>> And please fix this as well.
>
> My editor automatically inserts a new line at the end of the file.
> This behavior seems correct to me. Isn't it correct ?
>
Well it seems to have faile then in this case, since that marker indicates one
is missing...
>>
>> R.
>
> Matthieu
>
OK if you fix up that nit.
R.
