[Buildroot] [PATCH] bash: fix linking for static builds with uClibc toolchains

[Vicente Olivert Riera <Vincent.Riera@imgtec.com>]

Dear Arnout Vandecappelle,

On 10/21/2014 09:50 PM, Arnout Vandecappelle wrote:
> On 21/10/14 15:21, Vicente Olivert Riera wrote:
>> ...and also use configure options instead of environment variables.
>>
>> bash fails to link for static builds with uClibc toolchains due to
>> getenv redefinitions. This is caused because bash is unable to check if
>> getenv is already defined when cross-compiling, so it defaults to 'yes':
>>
>> configure:14438: WARNING: cannot check getenv redefinition if cross
>> compiling -- defaulting to yes
>>
>> We can avoid this redefinition by adding bash_cv_getenv_redef=no to the
>> configure options.
>>
>> At the same time, we use configure options instead of environment
>> variables because there is no need to pass those options to the
>> configure script as environment variables. Doing it in this way we
>> avoid the risk of environment variables leaking into places we don't
>> expect.
>
>   That change from _ENV to _OPTS should definitely be a separate patch.
> Especially because I don't see the reason to do it. The environment variables
> will leak into exactly one place: the configure script. And that script will
> just export all assignments passed on the command line into its environment. So
> the effect is exactly the same.
>
>   If you do make this change, then it should probably be done for all packages,
> which means it should probably be done in pkg-autotools.mk.
>
>   So you have a concrete example of where the _ENV causes trouble?

No, I haven't. I just prefer using configure options rather than 
environment variables. Anyway..., no problem, I will send another patch 
without that change.

>>
>> Related:
>> 	http://lists.gnu.org/archive/html/bug-bash/2012-03/msg00052.html
>>
>> Fixes:
>> 	http://autobuild.buildroot.net/results/a20/a2007e6dbcfe53e7cd837ae642869ee26376826a/
>>
>> Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
>> ---
>>   package/bash/bash.mk |    5 ++++-
>>   1 files changed, 4 insertions(+), 1 deletions(-)
>>
>> diff --git a/package/bash/bash.mk b/package/bash/bash.mk
>> index 34a3a73..9a13f69 100644
>> --- a/package/bash/bash.mk
>> +++ b/package/bash/bash.mk
>> @@ -13,7 +13,7 @@ BASH_CONF_OPTS = --with-installed-readline
>>   BASH_LICENSE = GPLv3+
>>   BASH_LICENSE_FILES = COPYING
>>
>> -BASH_CONF_ENV += \
>> +BASH_CONF_OPTS += \
>>   	ac_cv_rl_prefix="$(STAGING_DIR)" \
>>   	ac_cv_rl_version="$(READLINE_VERSION)" \
>>   	bash_cv_job_control_missing=present \
>> @@ -28,6 +28,9 @@ BASH_MAKE = $(MAKE1)
>>   # The static build needs some trickery
>>   ifeq ($(BR2_PREFER_STATIC_LIB),y)
>>   BASH_CONF_OPTS += --enable-static-link --without-bash-malloc
>> +ifeq ($(BR2_TOOLCHAIN_USES_UCLIBC),y)
>> +BASH_CONF_OPTS += bash_cv_getenv_redef=no
>> +endif
>
>   It's probably better to also set it to yes explicitly in the else branch.

No problem.

>   Also, a short comment would be good.

No problem.

>   Also, does musl allow redefining getenv?

Well, I did a test with a static build using the musl toolchain and it 
worked fine. So, yes, it seems that musl is ok with the getenv redefinition.

>
>
>   Regards,
>   Arnout
>
>>   endif
>>
>>   # Make /bin/sh -> bash (no other shell, better than busybox shells)
>>
>
>

Best regards,

-- 
Vicente Olivert Riera
Graduate Software Engineer, MIPS Processor IP
Imagination Technologies Limited
t: +44 (0)113 2429814
www.imgtec.com