seccomp-bpf-helpers: Fix undefined reference

seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build

Committed: https://crrev.com/b7865805147f5c616f13adb38448022d12ac97d2
Cr-Commit-Position: refs/heads/master@{#415208}

[Eric Caruso, 2016-08-29 19:42:20]

Description was changed from

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because a copy constructor is invoked on a shared_ptr with
a const template argument, and changing to a move constructor
fixes the issue.

BUG=None
TEST=Build
==========

to

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because a copy constructor is invoked on a shared_ptr with
a const template argument, and changing to a move constructor
fixes the issue.

BUG=None
TEST=Build
==========

[Eric Caruso, 2016-08-29 19:42:20]

ejcaruso@chromium.org changed reviewers:
+ mdempsky@chromium.org

[Eric Caruso, 2016-08-29 19:42:32]

PTAL, thanks.

[mdempsky, 2016-08-29 20:15:50]

As discussed on IM, I think the real problem here is that we're using
SANDBOX_EXPORT for symbols defined within both libseccomp_bpf.so and
libseccomp_bpf_helpers.so.  But if libseccomp_bpf_helpers.so needs exported
symbols from libseccomp_bpf.so, then we're going to have a bad time.  Oddly this
only seems to be problematic for CrOS debug builds, but perhaps the toolchain
there is more aggressive in its component compile flags.

I think the easiest fix is to just merge libseccomp_bpf_helpers.so into
libseccomp_bpf.so.  This won't introduce any new dependencies for
libseccomp_bpf.so and helpers is small anyway.  It also looks like
libseccomp_bpf_helpers is only mentioned in two places outside of sandbox/linux,
both of which already depend explicitly on libseccomp_bpf.

[Eric Caruso, 2016-08-29 23:06:45]

Description was changed from

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because a copy constructor is invoked on a shared_ptr with
a const template argument, and changing to a move constructor
fixes the issue.

BUG=None
TEST=Build
==========

to

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build
==========

[Eric Caruso, 2016-08-29 23:07:56]

ejcaruso@chromium.org changed reviewers:
+ sky@chromium.org

[Eric Caruso, 2016-08-29 23:07:56]

PTAL, thanks.

[mdempsky, 2016-08-29 23:25:27]

LGTM

Can you make the analogous changes to sandbox/linux/sandbox_linux.gypi and
services/shell/shell.gyp too?

[sky, 2016-08-29 23:58:06]

LGTM

[Eric Caruso, 2016-08-30 00:18:23]

Now with gyp changes.

[Eric Caruso, 2016-08-30 00:18:30]

The CQ bit was checked by ejcaruso@chromium.org

[Eric Caruso, 2016-08-30 00:18:31]

The patchset sent to the CQ was uploaded after l-g-t-m from sky@chromium.org,
mdempsky@chromium.org
Link to the patchset: https://codereview.chromium.org/2291783002/#ps40001
(title: "replicating changes in gyp files")

[commit-bot: I haz the power, 2016-08-30 02:13:07]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-30 06:14:46]

Description was changed from

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build
==========

to

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build
==========

[commit-bot: I haz the power, 2016-08-30 06:14:47]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-08-30 06:17:33]

Description was changed from

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build
==========

to

==========
seccomp-bpf-helpers: Fix undefined reference

Compiling a debug build in the chromeos chroot fails because
we can't link libseccomp_bpf_helpers.so. The failure occurs
because both seccomp_bpf and seccomp_bpf_helpers use
SANDBOX_EXPORT but are in different components and so the
symbols are visible but undefined in some circumstances.

BUG=None
TEST=Build

Committed: https://crrev.com/b7865805147f5c616f13adb38448022d12ac97d2
Cr-Commit-Position: refs/heads/master@{#415208}
==========

[commit-bot: I haz the power, 2016-08-30 06:17:33]

Patchset 3 (id:??) landed as
https://crrev.com/b7865805147f5c616f13adb38448022d12ac97d2
Cr-Commit-Position: refs/heads/master@{#415208}