[Buildroot] [PATCH 1/1] sdl: fix building on powerpc64 and powerpc64le

[Thomas Petazzoni]

Hello,

On Mon,  7 Nov 2016 14:29:44 +1100, Sam Bobroff wrote:
> Fixes
> http://autobuild.buildroot.net/results/70659eead71faa82ccfd0016d04caed134707c24
> 
> (The problem was detected when building chocolate-doom but the issue
> is in sdl.)
> 
> Old autotools included with SDL fails to detect dynamic linker support
> on powerpc64 and powerpc64le.
> 
> See SDL bug 3481: https://bugzilla.libsdl.org/show_bug.cgi?id=3481
> 
> Signed-off-by: Sam Bobroff <sam.bobroff at au1.ibm.com>

Thanks, but I have some comments, see below.

> ---
> 
>  package/sdl/0003-fix-configure-powerpc64.patch | 30 ++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>  create mode 100644 package/sdl/0003-fix-configure-powerpc64.patch
> 
> diff --git a/package/sdl/0003-fix-configure-powerpc64.patch b/package/sdl/0003-fix-configure-powerpc64.patch
> new file mode 100644
> index 0000000..764a947
> --- /dev/null
> +++ b/package/sdl/0003-fix-configure-powerpc64.patch
> @@ -0,0 +1,30 @@
> +sdl: Add powerpc64 and powerpc64le support to old autotools.
> +
> +Fixes build on powerpc64le which doesn't fail but produces a static library
> +rather than a dynamic one (which causes link errors in some packages using
> +libsdl).
> +
> +Signed-off-by: Sam Bobroff <sam.bobroff at au1.ibm.com>
> +
> +*** a/acinclude/libtool.m4	2016-11-07 14:04:47.444117880 +1100
> +--- b/acinclude/libtool.m4	2016-11-07 14:05:03.652181547 +1100
> +***************
> +*** 1302,1308 ****
> +  	  x86_64-*linux*)
> +  	    LD="${LD-ld} -m elf_x86_64"
> +  	    ;;
> +! 	  ppc*-*linux*|powerpc*-*linux*)
> +  	    LD="${LD-ld} -m elf64ppc"
> +  	    ;;
> +  	  s390*-*linux*|s390*-*tpf*)
> +--- 1302,1311 ----
> +  	  x86_64-*linux*)
> +  	    LD="${LD-ld} -m elf_x86_64"
> +  	    ;;
> +! 	  powerpc64le-*linux*)
> +! 	    LD="${LD-ld} -m elf64lppc"
> +! 	    ;;
> +! 	  powerpc64-*linux*)
> +  	    LD="${LD-ld} -m elf64ppc"
> +  	    ;;
> +  	  s390*-*linux*|s390*-*tpf*)

First, we want all patches formatted as unified diffs, so please use
this format when generating patches. Suggestion: for packages that
don't use Git upstream, use quilt to generate your patches.

Second, this change doesn't make the code look like what libtool.m4 has
in libtool upstream. It has:

          powerpc64le-*linux*)
            LD="${LD-ld} -m elf32lppclinux"
            ;;
          powerpc64-*linux*)
            LD="${LD-ld} -m elf32ppclinux"
            ;;
	[...]
          powerpcle-*linux*)
            LD="${LD-ld} -m elf64lppc"
            ;;

which is not the same as what your patch adds. Why do we have this
difference?

Also, are we going to need to patch libtool.m4 in each and every
package around? libtool.m4 from sdl is from libtool 2.2 which is not
_that_ old (by the standards of libtool upgrade speed, of course), so
we're likely to find many other packages in the same situation, aren't
we?

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com