Linux: add option for building with system re2.

Linux: add option for building with system re2.

Note that Google Chrome will continue to use bundled re2.
The option is off by default, and is intended for Linux distros.

BUG=165264
TEST=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=175227

[battre, 2012-11-02 13:35:24]

LGTM, thanks.

Do we need to modify the gyp files as well?

[Paweł Hajdan Jr., 2013-01-02 23:11:40]

This now uses generated shim headers. Could you take another look?

[battre, 2013-01-02 23:44:16]

Could you please try to find another reviewer? I don't feel qualified to review
this kind of GYP magic.

Thanks,
Dominic

[Paweł Hajdan Jr., 2013-01-03 00:23:05]

Ryan, could you take a look?

[Ryan Sleevi, 2013-01-03 00:38:35]

https://codereview.chromium.org/11366051/diff/4001/third_party/re2/re2.gyp
File third_party/re2/re2.gyp (right):

https://codereview.chromium.org/11366051/diff/4001/third_party/re2/re2.gyp#ne...
third_party/re2/re2.gyp:101: 're2/variadic_function.h',
Can you explain why you do not need to handle prog.h, regexp.h,
prefilter_tree.h, or unicode_groups.h?

I'm just trying to figure out how you determined this set of headers to
represent the 'public' API for shim-ing.

[Paweł Hajdan Jr., 2013-01-03 01:05:42]

https://codereview.chromium.org/11366051/diff/4001/third_party/re2/re2.gyp
File third_party/re2/re2.gyp (right):

https://codereview.chromium.org/11366051/diff/4001/third_party/re2/re2.gyp#ne...
third_party/re2/re2.gyp:101: 're2/variadic_function.h',
On 2013/01/03 00:38:35, Ryan Sleevi wrote:
> Can you explain why you do not need to handle prog.h, regexp.h,
> prefilter_tree.h, or unicode_groups.h?
> 
> I'm just trying to figure out how you determined this set of headers to
> represent the 'public' API for shim-ing.

This is what re2 snapshot I have installed into /usr/include . Chrome might be
using a different snapshot. For now I'm fine with the list in this CL.

[Ryan Sleevi, 2013-01-04 23:08:28]

Er, that was supposed to be LGTM