Try to resuscitate the builds needed to do official GN builds.

Try to resuscitate the builds needed to do official GN builds.

R=brettw@chromium.org
BUG=

Committed: https://crrev.com/ea8bc5e5ab38c0cf6e4a67bf78565301c9634e17
Cr-Commit-Position: refs/heads/master@{#302737}

[Dirk Pranke, 2014-11-04 21:59:56]

dpranke@chromium.org changed reviewers:
+ cmasone@chromium.org

[Dirk Pranke, 2014-11-04 21:59:57]

With these fixes, it looks like we can build the GN binaries on all 4 platforms.

Chris, do the ChromeOS changes look correct to you?

[brettw, 2014-11-04 22:32:20]

LGTM assuming Chris is happy with the gconf changes (I don't remember all the
details to be sure this is OK).

[Chris Masone, 2014-11-04 23:33:17]

This doesn't look good to me :-)

What builds are broken that you're trying to resuscitate?

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD.gn
File build/config/linux/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD...
build/config/linux/BUILD.gn:121: if (current_toolchain == default_toolchain) {
So, gconf is required only when compiling _target_ binaries for desktop Linux.
It is not actually required to compile host-side build tools. It's not available
in the CrOS build chroot because we don't need (or want) it.

The problem is that, when building host-side build tools as a part of building
for any other target, GN will also run through with is_linux=true and
is_chromeos=false...which means that  host tool compilation is mostly
indistinguishable from a desktop linux target build, even when you're building
for is_chromeos=true.

The case we'd really like to detect is "Currently building for the target, as
opposed to the host," which is a notion that GYP has but GN doesn't. The proxy
for this that we settled on is "There's no cross-compilation set up, so it's
probably fine to treat host and target builds the same for this".

Hence, checking that the toolchain currently in use is the host toolchain, which
is the same as the target (default) toolchain.

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn
File ui/display/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn#newc...
ui/display/BUILD.gn:58: if (is_chromeos) {
Ozone is pretty much a replacement for X11, so it really doesn't make sense to
have these when ozone's set to be used. What other platform is setting
use_ozone=true that wants these x11-specific files to still be here?

[brettw, 2014-11-04 23:47:52]

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD.gn
File build/config/linux/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD...
build/config/linux/BUILD.gn:121: if (current_toolchain == default_toolchain) {
This is necessary for the 32-bit cross-compile, where the default toolchain is
32-bit, and the host is 64-bit. 

We use the default toolchain as the target toolchain, so I think the new
condition should satisfy your requirements as well.

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn
File ui/display/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn#newc...
ui/display/BUILD.gn:58: if (is_chromeos) {
These are filtered out in the non-chromeos case by virtue of being in a chromeos
directory. Double-filtering is an error in GN, so this condition is required for
them to be filtered out in the chroemos case.

This is being triggered by GN itself, which is compiled with use_ozone = true to
avoid X dependencies. Ozone generally works on desktop Linux as well as
chromeos.

[Chris Masone, 2014-11-05 00:53:32]

LGTM

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD.gn
File build/config/linux/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/build/config/linux/BUILD...
build/config/linux/BUILD.gn:121: if (current_toolchain == default_toolchain) {
On 2014/11/04 23:47:52, brettw wrote:
> This is necessary for the 32-bit cross-compile, where the default toolchain is
> 32-bit, and the host is 64-bit. 
> 
> We use the default toolchain as the target toolchain, so I think the new
> condition should satisfy your requirements as well.

I definitely tried this first, and it didn't work in some case that I can no
longer reproduce :-)

If I run across it again, I'll start a thread explaining the problem to you guys
and we'll see what we can figure out.

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn
File ui/display/BUILD.gn (right):

https://codereview.chromium.org/699263002/diff/20001/ui/display/BUILD.gn#newc...
ui/display/BUILD.gn:58: if (is_chromeos) {
On 2014/11/04 23:47:52, brettw wrote:
> These are filtered out in the non-chromeos case by virtue of being in a
chromeos
> directory. Double-filtering is an error in GN, so this condition is required
for
> them to be filtered out in the chroemos case.
> 
> This is being triggered by GN itself, which is compiled with use_ozone = true
to
> avoid X dependencies. Ozone generally works on desktop Linux as well as
> chromeos.

Acknowledged.

[Dirk Pranke, 2014-11-05 00:57:43]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-11-05 00:59:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/699263002/20001

[commit-bot: I haz the power, 2014-11-05 01:47:23]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-05 01:48:00]

Patchset 2 (id:??) landed as
https://crrev.com/ea8bc5e5ab38c0cf6e4a67bf78565301c9634e17
Cr-Commit-Position: refs/heads/master@{#302737}