[Buildroot] [PATCH] make: requires dynamic libraries

[Ryan Barnett]

Thomas,

On Thu, Sep 17, 2015 at 4:27 PM, Thomas Petazzoni
<thomas.petazzoni at free-electrons.com> wrote:
> Ryan,
>
> On Wed, 16 Sep 2015 19:38:12 -0500, Ryan Barnett wrote:
>> While attempting to build make in a static library only configuration
>> the following error will be shown:
>>
>>  gc_pthread_redirects.h:37:22: fatal error: dlfcn.h: No such file or
>>  directory
>>   #   include <dlfcn.h>
>>
>> Fix this by depending make on !BR2_STATIC_LIBS.
>>
>> Fixes:
>>   http://autobuild.buildroot.net/results/814/8143ae0afac139845e5016058d85c800dc8527ad
>>
>> Signed-off-by: Ryan Barnett <ryanbarnett3 at gmail.com>
>
> Unfortunately, I believe this is not the proper fix. If you use
> http://autobuild.buildroot.org/toolchains/configs/br-arm-full-static.config
> and build just the make package, it builds just fine:
>
> $ file output/target/usr/bin/make
> output/target/usr/bin/make: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, stripped
>
> The file gc_pthread_redirects.h comes, I believe, from bdwgc, which got
> built before make in the autobuild test case you're pointing to. This
> header file is known to incorrectly include <dlfcn.h>, unless
> GC_NO_DLOPEN is specified. See what is done in guile.mk for example to
> pass GC_NO_DLOPEN when BR2_STATIC_LIBS=y.
>
> I believe the chain is that you have bdwgc that gets built, then guile,
> then make. In this case, make detects the availability of guile and
> uses it, which is the reason why gc_pthread_redirects.h gets included
> by make.

Thank you for the detailed explanation! I had quickly seen how this
was addressed in the past via a search of the mailing list.

> So I suggest one of the two options:
>
>  * Make the optional dependency of make on guile explicit in make.mk,
>    and pass GC_NO_DLOPEN when we're building statically.
>
>  * Disable guile support completely in make. I don't think we care
>    about having guile support in make in the context of Buildroot, so
>    this is probably the easiest solution.

I am going to go disabling guile support in a static only
configuration. I ran into an issue with setting GC_NO_DLOPEN define in
that there then becomes multiple definitions of locale_charset between
libintl and libguile and I wasn't sure how to properly fix it. Looking
at what guile is used for in make, it doesn't appear extremely useful
especially in a static only configuration.

Thanks,
-Ryan