Introduce host_pkg_config variable for cross-compilation

Introduce host_pkg_config variable for cross-compilation

When cross-compiling in the ChromiumOS chroot, it's possible for
host-based compiled_actions targets to pick up libraries in the board 
sysroot which causes linker warnings (converted to errors via
--fatal-warnings). To address this, introduce a host_pkg_config
variable, which can override pkg_config when building tools used on 
the host as part of the build process.

BUG=710841
Review-Url: https://codereview.chromium.org/2818523002
Cr-Commit-Position: refs/heads/master@{#466947}
Committed: https://chromium.googlesource.com/chromium/src/+/0dbb630385d7bd387348b00437e72b611287cb49

[richard.townsend, 2017-04-12 18:16:11]

Description was changed from

==========
Introduce host_pkg_config variable for cross-compilation

When cross-compiling, in the ChromiumOS chroot, it's possible for
host-based compiled_actions to pick up libraries in the board sysroot,
which causes linker warnings (converted to errors via
--fatal-warnings). To address this, introduce a host_pkg_config
variable, which can override pkg_config for tools built to be used on
the host as part of the build process.

BUG=710841
==========

to

==========
Introduce host_pkg_config variable for cross-compilation

When cross-compiling in the ChromiumOS chroot, it's possible for
host-based compiled_actions targets to pick up libraries in the board 
sysroot which causes linker warnings (converted to errors via
--fatal-warnings). To address this, introduce a host_pkg_config
variable, which can override pkg_config when building tools used on 
the host as part of the build process.

BUG=710841
==========

[cavalcantii1, 2017-04-12 18:25:26]

The CQ bit was checked by cavalcantii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-12 18:26:25]

Dry run: 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, 2017-04-12 18:34:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-12 18:34:38]

Dry run: Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_compile_dbg_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_tsan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[gurchetansingh, 2017-04-12 19:21:33]

gurchetansingh@chromium.org changed reviewers:
+ brettw@chromium.org, dpranke@chromium.org, scottmg@chromium.org

[richard.townsend, 2017-04-18 19:43:25]

Patchset #2 (id:20001) has been deleted

[cavalcantii1, 2017-04-20 18:14:18]

The CQ bit was checked by cavalcantii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-20 18:14:57]

Dry run: 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, 2017-04-20 19:18:22]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-20 19:18:23]

Dry run: Try jobs failed on following builders:
  android_compile_dbg on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_comp...)

[cavalcantii1, 2017-04-20 22:00:52]

The CQ bit was checked by cavalcantii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-20 22:01:31]

Dry run: 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, 2017-04-20 23:09:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-20 23:09:47]

Dry run: This issue passed the CQ dry run.

[richard.townsend, 2017-04-20 23:19:47]

richard.townsend@arm.com changed reviewers:
+ gurchetansingh@chromium.org, lgarron@chromium.org, vapier@chromium.org

[richard.townsend, 2017-04-20 23:19:47]

This patch is ready to review, it maintains the existing pkg_config behaviour
across all platforms for now, but a patch which builds on this and corrects the
problematic behaviour displayed in #710841 is available at
https://chromium-review.googlesource.com/c/483342/

[vapier, 2017-04-20 23:27:38]

seems ok, but i'm not a GN expert at all

[Dirk Pranke, 2017-04-21 00:25:25]

Basically looks fine. The comments are slightly more than nits, but only
slightly :).

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
File build/config/linux/pkg_config.gni (right):

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
build/config/linux/pkg_config.gni:88: # Only use the custom libdir when building
with the target sysroot.
Why did this comment move?

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
build/config/linux/pkg_config.gni:93: }
I'd probably move this if down to line 97 and just have

if (current == host) {
  args = host_pkg_config_args + invoker.packages
} else {
  args = pkg_config_args + invoker.packages
}

[richard.townsend, 2017-04-21 17:08:03]

Awaiting someone with permission to check the CQ bit on patchset #4.

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
File build/config/linux/pkg_config.gni (right):

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
build/config/linux/pkg_config.gni:88: # Only use the custom libdir when building
with the target sysroot.
On 2017/04/21 00:25:25, Dirk Pranke wrote:
> Why did this comment move?

Done.

https://codereview.chromium.org/2818523002/diff/60001/build/config/linux/pkg_...
build/config/linux/pkg_config.gni:93: }
On 2017/04/21 00:25:25, Dirk Pranke wrote:
> I'd probably move this if down to line 97 and just have
> 
> if (current == host) {
>   args = host_pkg_config_args + invoker.packages
> } else {
>   args = pkg_config_args + invoker.packages
> }

Done.

[cavalcantii1, 2017-04-21 18:08:23]

The CQ bit was checked by cavalcantii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-21 18:08:54]

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

[Dirk Pranke, 2017-04-21 18:10:58]

lgtm, thanks!

[commit-bot: I haz the power, 2017-04-21 19:30:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-21 19:30:02]

Dry run: This issue passed the CQ dry run.

[richard.townsend, 2017-04-24 10:36:53]

The CQ bit was checked by richard.townsend@arm.com

[commit-bot: I haz the power, 2017-04-24 10:37:06]

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, 2017-04-24 13:21:32]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-24 13:21:33]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[richard.townsend, 2017-04-25 10:44:16]

The CQ bit was checked by richard.townsend@arm.com

[commit-bot: I haz the power, 2017-04-25 10:44:23]

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, 2017-04-25 11:58:47]

CQ is committing da patch.

Bot data: {"patchset_id": 80001, "attempt_start_ts": 1493117056706170,
"parent_rev": "387c2f19a653715fc14e8ee857fba3323fa92ba8", "commit_rev":
"0dbb630385d7bd387348b00437e72b611287cb49"}

[commit-bot: I haz the power, 2017-04-25 11:58:55]

Description was changed from

==========
Introduce host_pkg_config variable for cross-compilation

When cross-compiling in the ChromiumOS chroot, it's possible for
host-based compiled_actions targets to pick up libraries in the board 
sysroot which causes linker warnings (converted to errors via
--fatal-warnings). To address this, introduce a host_pkg_config
variable, which can override pkg_config when building tools used on 
the host as part of the build process.

BUG=710841
==========

to

==========
Introduce host_pkg_config variable for cross-compilation

When cross-compiling in the ChromiumOS chroot, it's possible for
host-based compiled_actions targets to pick up libraries in the board 
sysroot which causes linker warnings (converted to errors via
--fatal-warnings). To address this, introduce a host_pkg_config
variable, which can override pkg_config when building tools used on 
the host as part of the build process.

BUG=710841

Review-Url: https://codereview.chromium.org/2818523002
Cr-Commit-Position: refs/heads/master@{#466947}
Committed:
https://chromium.googlesource.com/chromium/src/+/0dbb630385d7bd387348b00437e7...
==========

[commit-bot: I haz the power, 2017-04-25 11:58:56]

Committed patchset #4 (id:80001) as
https://chromium.googlesource.com/chromium/src/+/0dbb630385d7bd387348b00437e7...