[Buildroot] [PATCH] toolchain-buildroot: glibc: Remove the default choice of built-in SunRPC

[Arnout Vandecappelle <arnout@mind.be>]

On 11/12/2020 13:12, Veronika Kremneva wrote:
> There is an error present when building lmbench with glibc-2.26 and above:
> ----------------------------->8---------------------------
> Makefile:226: recipe for target '../bin/arc/lib_udp.o' failed
> make[2]: *** [../bin/arc/lib_udp.o] Error 1
> In file included from lib_unix.c:9:
> bench.h:39:10: fatal error: rpc/rpc.h: No such file or directory
>    39 | #include <rpc/rpc.h>
>       |          ^~~~~~~~~~~
> compilation terminated.
> Makefile:228: recipe for target '../bin/arc/lib_unix.o' failed
> make[2]: *** [../bin/arc/lib_unix.o] Error 1
> In file included from lib_timing.c:17:
> bench.h:39:10: fatal error: rpc/rpc.h: No such file or directory
>    39 | #include <rpc/rpc.h>
>       |          ^~~~~~~~~~~
> compilation terminated.
> ----------------------------->8---------------------------
> You can find more details about failed builds here:
> http://autobuild.buildroot.net/?reason=lmbench-3.0-a9
> 
> This happens because native implementation of Sun RPC was removed
> from glibc and moved to a separate library (libtirpc):
> https://fedoraproject.org/wiki/Changes/SunRPCRemoval
> 
> Yet in Buildroot we still assume BR2_TOOLCHAIN_HAS_NATIVE_RPC
> in case of glibc, which is not true.
> 
> The following patch removes the default assumption that glibc
> has a built-in implementation of SunRPC.
> 
> Signed-off-by: Veronika Kremneva <kremneva@synopsys.com>
> ---
>  toolchain/toolchain-buildroot/Config.in | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/toolchain/toolchain-buildroot/Config.in b/toolchain/toolchain-buildroot/Config.in
> index 2058ff1eb9..74aa9abc25 100644
> --- a/toolchain/toolchain-buildroot/Config.in
> +++ b/toolchain/toolchain-buildroot/Config.in
> @@ -59,8 +59,6 @@ config BR2_TOOLCHAIN_BUILDROOT_GLIBC
>  	depends on !BR2_powerpc_SPE
>  	depends on BR2_RISCV_ISA_RVA || !BR2_riscv
>  	select BR2_TOOLCHAIN_USES_GLIBC
> -	# our glibc.mk enables RPC support

 As you see from this comment, we *do* enable rpc support in our glibc build.

 However, this feature is removed in glibc 2.32. In Buildroot, we are still
using glibc 2.31 - except for ARC and RISCV-32. So I guess you're using one of
those. Well, based on your e-mail, probably ARC :-). Please note in the commit
message that it is really removed in glibc 2.32.

 I think this obsolete RPC was a transitory measure for when some versions of
glibc still had RPC bundled. Now, I indeed think we can remove it.

 In addition to this, we should also remove the --enable-obsolete-rpc flag from
glibc.mk. And maybe also check if nsswitch.conf needs to be adapted as well.

 Romain, can you think of anything else that has to change?

 Ideally we should be able to remove BR2_TOOLCHAIN_HAS_NATIVE_RPC completely,
but there are external toolchains that still have it bundled, so we can't do
that yet.

 Thomas, the script that generates the external bootlin toolchain
Config.in.options files will need to be adapted as well.

 Regards,
 Arnout


> -	select BR2_TOOLCHAIN_HAS_NATIVE_RPC
>  	help
>  	  This option selects glibc as the C library for the
>  	  cross-compilation toolchain.
>