[PATCH 3/3] ldso: exclude -fasynchronous-unwind-tables from ldso CFLAGS

[Rich Felker]

On Fri, Sep 13, 2013 at 10:31:53AM +0200, Filippo ARCIDIACONO wrote:
> At least on ARM, building the ld.so with -fasynchronous-unwind-tables
> for backtrace is creating a dependencies against libc through libgcc_eh.
> So it needs to exclude this from the ldso cflags.

Have you figured out why this is happening? I think it's a GCC bug
which should be reported; we've had similar problems with bogus
libgcc_eh dependencies on ARM in musl, but fortunately they're much
easier for us to solve.

> Signed-off-by: Carmelo Amoroso <carmelo.amoroso at st.com>
> Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono at st.com>
> ---
>  ldso/ldso/Makefile.in |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/ldso/ldso/Makefile.in b/ldso/ldso/Makefile.in
> index 91165c6..65f9a46 100644
> --- a/ldso/ldso/Makefile.in
> +++ b/ldso/ldso/Makefile.in
> @@ -30,6 +30,8 @@ CFLAGS-ldso/ldso/$(TARGET_ARCH)/ := $(CFLAGS-ldso)
>  
>  CFLAGS-ldso.c := -DLDSO_ELFINTERP=\"$(TARGET_ARCH)/elfinterp.c\" $(CFLAGS-ldso)
>  
> +CFLAGS-OMIT-ldso.c = -fasynchronous-unwind-tables
> +

How does this work? -fasynchronous-unwind-tables is the GCC default.
You need -fno-asynchronous-unwind-tables to turn them off.

Rich