[3/3] libunwind: fix build when unused sections are garbage collected

poky-tiny uses gcsections.inc to strip unused sections from the
binaries.  However, on qemuarm5/qemuarm64 with poky-tiny this appears to
result in too much being removed and the link fails:

  ld: .libs/Gtest-trace: hidden symbol `__aarch64_cas8_acq_rel' in
  libgcc.a(cas_8_4.o) is referenced by DSO

Work around this by disabling gcsections.inc.

Signed-off-by: Ross Burton <ross.burton@arm.com>
---
 meta/recipes-support/libunwind/libunwind_1.8.1.bb | 4 ++++
 1 file changed, 4 insertions(+)

On Fri, Apr 25, 2025 at 4:23 AM Ross Burton via lists.openembedded.org
<ross.burton=arm.com@lists.openembedded.org> wrote:
>
> poky-tiny uses gcsections.inc to strip unused sections from the
> binaries.  However, on qemuarm5/qemuarm64 with poky-tiny this appears to
> result in too much being removed and the link fails:
>
>   ld: .libs/Gtest-trace: hidden symbol `__aarch64_cas8_acq_rel' in
>   libgcc.a(cas_8_4.o) is referenced by DSO
>
> Work around this by disabling gcsections.inc.
>
> Signed-off-by: Ross Burton <ross.burton@arm.com>
> ---
>  meta/recipes-support/libunwind/libunwind_1.8.1.bb | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/meta/recipes-support/libunwind/libunwind_1.8.1.bb b/meta/recipes-support/libunwind/libunwind_1.8.1.bb
> index 38022569df2..b22cb30646e 100644
> --- a/meta/recipes-support/libunwind/libunwind_1.8.1.bb
> +++ b/meta/recipes-support/libunwind/libunwind_1.8.1.bb
> @@ -32,6 +32,10 @@ EXTRA_OECONF = "--enable-static"
>  ARM_INSTRUCTION_SET:armv4 = "arm"
>  ARM_INSTRUCTION_SET:armv5 = "arm"
>
> +# With qemuarm64 and poky-tiny:
> +# ld: .libs/Gtest-trace: hidden symbol `__aarch64_cas8_acq_rel' in libgcc.a(cas_8_4.o) is referenced by DSO
> +LDFLAGS_SECTION_REMOVAL = ""
> +

While it seems to be fine here, I wonder if it should be in
meta-poky/conf/distro/include/gcsections.inc as well.

>  LDFLAGS += "-Wl,-z,relro,-z,now"
>
>  SECURITY_LDFLAGS:append:libc-musl = " -lssp_nonshared"
> --
> 2.43.0
>
>
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