Support external clang source directory in //tools/clang/CMakeList.txt

Support external clang source directory in //tools/clang/CMakeList.txt

Chromium clang plugins depends on clang headers, and the configuration
file assumes it's checked out in a fixed path in the LLVM source tree.
That is inconvenient to build it out of tree.

This CL adjusts the include path setting for external checkout of clang.

Committed: https://crrev.com/a282d1102e24eeafa4b8525a572884a11c89a9e4
Cr-Commit-Position: refs/heads/master@{#423809}

[tzik, 2016-10-06 16:04:29]

tzik@chromium.org changed reviewers:
+ thakis@chromium.org

[tzik, 2016-10-06 16:04:30]

PTAL.

Don't you mind adding a code to build clang plugins out of chromium tree?
Since the build script replaces //third_party/llvm-build and GOMA doesn't work
it, I want to build clang tools out of chromium tree and want to integrate to my
toolchains.
For it, adjusting the include path by this CL makes it easier.

WDYT?

[Nico, 2016-10-06 16:11:54]

lgtm

In general I feel this script is only for building chromium clang packages and
for downloading them, not for local development. But the patch is small, so if
it helps you I think we can land it.

[dcheng, 2016-10-06 16:33:14]

On 2016/10/06 16:11:54, Nico wrote:
> lgtm
> 
> In general I feel this script is only for building chromium clang packages and
> for downloading them, not for local development. But the patch is small, so if
> it helps you I think we can land it.

Out of curiosity, what's your workflow?

[tzik, 2016-10-07 06:32:57]

On 2016/10/06 16:33:14, dcheng wrote:
> On 2016/10/06 16:11:54, Nico wrote:
> > lgtm
> > 
> > In general I feel this script is only for building chromium clang packages
and
> > for downloading them, not for local development. But the patch is small, so
if
> > it helps you I think we can land it.
> 
> Out of curiosity, what's your workflow?

Are you asking to me or Nico?

When I develop a clang refactoring tool in chromium tree, I run
//tools/clang/scripts/update.py with --tools option (or just run `ninja -C
third_party/llvm-build` for incremental build), and run the tool with
//tools/clang/scripts/run_tool.py.
Though, that clears downloaded clang binary, and the locally built clang doesn't
work with goma, since it's not uploaded.

After this CL, I'll switch to an out-of-chromium tree build of the refactoring
tool. I'll build it and develop it in a collection of my locally build
toolchain, pull back it to the chromium tree.

[tzik, 2016-10-07 06:33:58]

The CQ bit was checked by tzik@chromium.org

[commit-bot: I haz the power, 2016-10-07 06:34:10]

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, 2016-10-07 06:42:26]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-10-07 06:44:25]

Description was changed from

==========
Support external clang source directory in //tools/clang/CMakeList.txt

Chromium clang plugins depends on clang headers, and the configuration
file assumes it's checked out in a fixed path in the LLVM source tree.
That is inconvenient to build it out of tree.

This CL adjusts the include path setting for external checkout of clang.
==========

to

==========
Support external clang source directory in //tools/clang/CMakeList.txt

Chromium clang plugins depends on clang headers, and the configuration
file assumes it's checked out in a fixed path in the LLVM source tree.
That is inconvenient to build it out of tree.

This CL adjusts the include path setting for external checkout of clang.

Committed: https://crrev.com/a282d1102e24eeafa4b8525a572884a11c89a9e4
Cr-Commit-Position: refs/heads/master@{#423809}
==========

[commit-bot: I haz the power, 2016-10-07 06:44:26]

Patchset 2 (id:??) landed as
https://crrev.com/a282d1102e24eeafa4b8525a572884a11c89a9e4
Cr-Commit-Position: refs/heads/master@{#423809}