Re: [PATCH] Correctly determine libc.so 'OUTPUT_FORMAT' when cross-compiling.

["Ludovic Courtès" <ludo@gnu.org>]

Hi Carlos,

Carlos O'Donell <carlos@redhat.com> skribis:

> On Thu, Jul 01, 2021 at 11:00:19PM +0200, Ludovic Courtès via Libc-alpha wrote:
>> Commit 87d583c6e8cd0e49f64da76636ebeec033298b4d replaces the sed script
>> with an "objdump -f" invocation to determine the 'OUTPUT_FORMAT' bit of
>> the libc.so linker script.
>> 
>> However, when cross-compiling, for example from x86_64-linux-gnu to
>> aarch64-linux-gnu, "objdump -f" would report the wrong
>> format ("elf64-little").  Conversely, "aarch64-linux-gnu-objdump -f"
>> reports "elf64-littleaarch64" as expected.
>> 
>> This patch changes 'configure.ac' to use AC_CHECK_TOOL rather than
>> '$CC -print-prog-name=objdump' to determine the value of the OBJDUMP
>> variable.  That way, OBJDUMP is set to TRIPLET-objdump when
>> cross-compiling for TRIPLET.
>
> I've been tackling a backlog of old glibc patches, and this one is up
> next. Yes it's been over a year, but this patch still applies and the
> idea is sound. I've tested this with build-many-glibcs (bmg) on x86_64
> and it has no impact because bmg always sets OBJDUMP. My opinion is that
> bmg is the "base standard" for how we build native and cross tooling and
> so it your changes work here, they should work in other instances.
>
> The change looks good to me.
>
> No regresions on x86_64.
>
> Would you like me to commit this? :-)

I don’t have commit access AFAIK so I’ll happily defer to you.  :-)

Thanks for taking the time to look at the backlog!

Ludo’.