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 } } } } */
> \ No newline at end of file
And please fix this as well.
R.
