Work on Clang for pure GN build.

Work on Clang for pure GN build.

This hooks up Clang in the pure GN build (not the hybrid GYP mode).

Clang gave some warnings about compiler flags which made me realize that we were giving linker flags to the compiler in some cases. So I enhanced our pkg-config wrapper to to add libraries to the cflags (missing else), return ldflags separately, and also strip out -pthread which was getting included over and over.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=248477

[brettw, 2014-01-29 08:13:33]

A bunch of other stuff like goma is still not hooked up.

[Nico, 2014-01-29 18:45:48]

lgtm

https://codereview.chromium.org/147923010/diff/1/build/toolchain/linux/BUILD.gn
File build/toolchain/linux/BUILD.gn (right):

https://codereview.chromium.org/147923010/diff/1/build/toolchain/linux/BUILD....
build/toolchain/linux/BUILD.gn:50: gcc_toolchain("arm") {
clang can target arm too fwiw (the same clang binary can code for various
architectures, the compiler binary - target code mapping isn't 1-1 like with
gcc)

https://codereview.chromium.org/147923010/diff/1/build/toolchain/linux/BUILD....
build/toolchain/linux/BUILD.gn:70: cxx = "$prefix/clang++"
Will this harmonize with use_goma=1?

[brettw, 2014-01-30 00:24:03]

https://codereview.chromium.org/147923010/diff/1/build/toolchain/linux/BUILD.gn
File build/toolchain/linux/BUILD.gn (right):

https://codereview.chromium.org/147923010/diff/1/build/toolchain/linux/BUILD....
build/toolchain/linux/BUILD.gn:70: cxx = "$prefix/clang++"
On 2014/01/29 18:45:48, Nico wrote:
> Will this harmonize with use_goma=1?

No, I haven't looked at Goma yet.

[brettw, 2014-02-03 09:19:13]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2014-02-03 09:19:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brettw@chromium.org/147923010/1

[commit-bot: I haz the power, 2014-02-03 12:11:40]

Change committed as 248477

[commit-bot: I haz the power, 2014-02-03 12:11:41]

CQ bit was unchecked on CL. Ignoring.

[commit-bot: I haz the power, 2014-02-03 12:11:45]

CQ bit was unchecked on CL. Ignoring.

[Nico, 2014-02-19 05:09:10]

https://codereview.chromium.org/147923010/diff/1/build/config/linux/pkg-confi...
File build/config/linux/pkg-config.py (right):

https://codereview.chromium.org/147923010/diff/1/build/config/linux/pkg-confi...
build/config/linux/pkg-config.py:33: print "[[],[],[],[]]"
I guess this should now read "[[],[],[],[],[]]"?

[Nico, 2014-02-19 05:18:23]

https://codereview.chromium.org/147923010/diff/1/build/config/linux/pkg-confi...
File build/config/linux/pkg-config.py (right):

https://codereview.chromium.org/147923010/diff/1/build/config/linux/pkg-confi...
build/config/linux/pkg-config.py:33: print "[[],[],[],[]]"
On 2014/02/19 05:09:10, Nico wrote:
> I guess this should now read "[[],[],[],[],[]]"?

=> https://codereview.chromium.org/171993002/