Add third_party/elfutils:libelf to the gn build.

Add third_party/elfutils:libelf to the gn build.

Add a build of libelf to gn.  Built for host only, as support for
build-time tools.  Not built for targets.

BUG=

Committed: https://crrev.com/eda109c9306e232edcbd9f46232d440216ea1564
Cr-Commit-Position: refs/heads/master@{#299280}

[simonb (inactive), 2014-10-10 17:43:01]

simonb@chromium.org changed reviewers:
+ brettw@chromium.org

[brettw, 2014-10-10 17:48:04]

https://codereview.chromium.org/647823002/diff/1/BUILD.gn
File BUILD.gn (right):

https://codereview.chromium.org/647823002/diff/1/BUILD.gn#newcode72
BUILD.gn:72: "//third_party/elfutils:libelf($host_toolchain)",
We only want to build this for desktop Linux, which means it probably shouldn't
be in this list. I suspect that this target is one that should only be brought
in "organically" when something else depends on it rather than always being
built. Is something like that coming in a followup?

https://codereview.chromium.org/647823002/diff/1/third_party/elfutils/BUILD.gn
File third_party/elfutils/BUILD.gn (right):

https://codereview.chromium.org/647823002/diff/1/third_party/elfutils/BUILD.g...
third_party/elfutils/BUILD.gn:143: "src/libelf",
You don't need this one since it's in the public config (which also applies to
this target).

[simonb (inactive), 2014-10-10 18:00:47]

Thanks.  Updated in patch set 2.

https://codereview.chromium.org/647823002/diff/1/BUILD.gn
File BUILD.gn (right):

https://codereview.chromium.org/647823002/diff/1/BUILD.gn#newcode72
BUILD.gn:72: "//third_party/elfutils:libelf($host_toolchain)",
On 2014/10/10 17:48:04, brettw wrote:
> We only want to build this for desktop Linux, which means it probably
shouldn't
> be in this list. I suspect that this target is one that should only be brought
> in "organically" when something else depends on it rather than always being
> built. Is something like that coming in a followup?

Gone, then (though this makes it awkward to test with gn gen ...).

The thing that depends on this -- tools/relocation_packer -- doesn't yet build
with gn, but when I have that working then yes, libelf will be drawn in to the
host build via dependencies.

https://codereview.chromium.org/647823002/diff/1/third_party/elfutils/BUILD.gn
File third_party/elfutils/BUILD.gn (right):

https://codereview.chromium.org/647823002/diff/1/third_party/elfutils/BUILD.g...
third_party/elfutils/BUILD.gn:143: "src/libelf",
On 2014/10/10 17:48:04, brettw wrote:
> You don't need this one since it's in the public config (which also applies to
> this target).

Done.

[brettw, 2014-10-10 18:05:20]

Okay, let's just land this not-hooked-up yet and so it's ready to use when we
get to the packer tool. LGTM

[simonb (inactive), 2014-10-13 10:25:50]

The CQ bit was checked by simonb@chromium.org

[commit-bot: I haz the power, 2014-10-13 10:26:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/647823002/90001

[commit-bot: I haz the power, 2014-10-13 10:46:24]

Committed patchset #2 (id:90001)

[commit-bot: I haz the power, 2014-10-13 10:47:11]

Patchset 2 (id:??) landed as
https://crrev.com/eda109c9306e232edcbd9f46232d440216ea1564
Cr-Commit-Position: refs/heads/master@{#299280}