clang support

Support for building Chrome using Clang.

To build, set the clang=1 gyp_define.

This patch is the culmination of many months of effort and many
patches.  It contains the minimal changes to Chrome that
are Clang-specific.

With this, I can build the "chrome" target.  Once this patch
is in, we can incrementally fix bits of Chrome and various
tests and remove the Clang-specific workarounds.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=59882

[Evan Martin, 2010-09-17 23:40:50]

I'd like to land this patch now (minus the llvm.sh in it).
What do you think?

I'm only a bit hesitant because of the linked_list change;
I might put it behind #ifdef __clang__.

[Nico, 2010-09-17 23:52:12]

On 2010/09/17 23:40:50, Evan Martin wrote:
> I'd like to land this patch now (minus the llvm.sh in it).
> What do you think?

Awesome! I'm all for it. LG.
 
> I'm only a bit hesitant because of the linked_list change;
> I might put it behind #ifdef __clang__.

Personally, I don't think that's necessary.

[Nico, 2010-09-17 23:52:40]

<reply-doesnt-send-comments-ffffuuu />

http://codereview.chromium.org/522020/diff/97001/98003
File chrome/browser/zygote_main_linux.cc (right):

http://codereview.chromium.org/522020/diff/97001/98003#newcode56
chrome/browser/zygote_main_linux.cc:56: // we aren't using SELinux or clang.
is there a reason for this?

[Evan Martin, 2010-09-17 23:53:58]

http://codereview.chromium.org/522020/diff/97001/98003
File chrome/browser/zygote_main_linux.cc (right):

http://codereview.chromium.org/522020/diff/97001/98003#newcode56
chrome/browser/zygote_main_linux.cc:56: // we aren't using SELinux or clang.
On 2010/09/17 23:52:40, Nico wrote:
> is there a reason for this?

Seccomp is really gcc specific right now.

[hans, 2010-09-20 08:11:48]

Very nice to see this stuff going in!

LGTM

http://codereview.chromium.org/522020/diff/97001/98001
File base/linked_list.h (right):

http://codereview.chromium.org/522020/diff/97001/98001#newcode132
base/linked_list.h:132: previous_ = prev; next_ = next;
Nit: two statements on a single row like this is quite rare in Chromium, I
think?