package/bluez5_utils: fix build
authorFabrice Fontaine <fontaine.fabrice@gmail.com>
Sun, 12 Sep 2021 12:22:52 +0000 (14:22 +0200)
committerYann E. MORIN <yann.morin.1998@free.fr>
Sun, 12 Sep 2021 20:17:44 +0000 (22:17 +0200)
commita02927b94ae4e8688571536667550853abda7b51
tree7f7968f242a38fe6e968bac8a2598c81833448b3
parent08f935ac45589fd1ac022cf295f6db6e3b677974
package/bluez5_utils: fix build

pause() is defined in glibc since the very early times; it appears in
upstream commit 28f540f45bba (initial import) in 1995 [0].

Bluez has been defining a function named pause() for ages too, since
comit caab74c97542 (media: Implement new callbacks for pass-through
operations) in 2013 [1]

With the recent bump to glibc 2.34.xxx, the build now fails because the
two pause() clash:

    profiles/audio/media.c:1284:13: error: conflicting types for 'pause'
     1284 | static bool pause(void *user_data)
          |             ^~~~~
    In file included from /tmp/instance-0/output-1/per-package/bluez5_utils/host/s390x-buildroot-linux-gnu/sysroot/usr/include/bits/sigstksz.h:24,
                     from /tmp/instance-0/output-1/per-package/bluez5_utils/host/s390x-buildroot-linux-gnu/sysroot/usr/include/signal.h:328,
                     from /tmp/instance-0/output-1/per-package/bluez5_utils/host/bin/../s390x-buildroot-linux-gnu/sysroot/usr/include/glib-2.0/glib/gbacktrace.h:36,
                     from /tmp/instance-0/output-1/per-package/bluez5_utils/host/bin/../s390x-buildroot-linux-gnu/sysroot/usr/include/glib-2.0/glib.h:34,
                     from profiles/audio/media.c:21:
    /tmp/instance-0/output-1/per-package/bluez5_utils/host/s390x-buildroot-linux-gnu/sysroot/usr/include/unistd.h:489:12: note: previous declaration of 'pause' was here
      489 | extern int pause (void);
          |            ^~~~~

The culprit is indeed glibc 2.34, as can be seen in this result matrix:

         \   bluez5_utils
    glibc \  5.60  |  5.61
    -------\-------+--------
    2.33   |  OK   |   OK
    -------+-------+--------
    2.34   |  KO   |   KO

Even though we first bumped to glibc 2.34, then to blues5_utils 5.61,
we did not notice build issues with bluez5_utils 5.60 because the two
bumps were too close to each other for the failure to trigger in the
autobuilders.

The underlying reason that pause() is now causing issues with glibc 2.34
is not obvious: glibc is a big beast, and finding such issues is not
easy. However, we can see that the pause() provided by NPTL has been
dropped in favour of the generic one, so maybe this is causing symbol
visibility or weakness to change or something...

We fix that by renaming the local pause() in bluez5_utils with a
namespace-prefix, like some other functions there already have.

Fixes:
  - http://autobuild.buildroot.org/results/c4f/c4fbface34be8815838fd7201621d7a8fddd32c5/
  - http://autobuild.buildroot.org/results/62b/62b88740f19fbe4a1ad7959dc141d539eb88c1f8/

[0] https://sourceware.org/git/?p=glibc.git;a=commit;h=28f540f45bbacd939bfd07f213bcad2bf730b1bf
[1] https://github.com/bluez/bluez/commit/caab74c97542a56b591f0b16b44ab6ba4b40f0f5

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[yann.morin.1998@free.fr: extend commit log with the glibc culprit]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
package/bluez5_utils/0002-profiles-audio-media.c-rename-pause.patch [new file with mode: 0644]