Add use_system_v8 option to gyp (off by default),...

Add use_system_v8 option to gyp (off by default),
as discussed in http://groups.google.com/group/v8-users/browse_thread/thread/33a69c51d8023ced

This will make it easier for Linux distributions
to ship with system-provided V8 library.

Committed: http://code.google.com/p/v8/source/detail?r=6153

[Paweł Hajdan Jr., 2011-01-04 09:18:07]

I'm not sure who should review this; please add more reviewers if needed.

I've signed the CLA for the Chromium project, and I'm sending this review from
my @chromium.org address. Please let me know if I should do something more.

[Søren Thygesen Gjesse, 2011-01-04 11:39:19]

This change is really confusing the differ, but you only added the new outer
condition, indented 4 chars and added the targets v8 and v8_shell in the else
part, right?

However please format this to be inside the 80 char line length.

[Paweł Hajdan Jr., 2011-01-04 11:56:56]

On 2011/01/04 11:39:19, Søren Gjesse wrote:
> This change is really confusing the differ, but you only added the new outer
> condition, indented 4 chars and added the targets v8 and v8_shell in the else
> part, right?

Yes.

> However please format this to be inside the 80 char line length.

Done where it was trivial. There are two cases where I don't know what to do,
see below.

http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp
File tools/gyp/v8.gyp (right):

http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp#newcode262
tools/gyp/v8.gyp:262:
'<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)mksnapshot<(EXECUTABLE_SUFFIX)',
I'm not sure how to wrap this line.

http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp#newcode801
tools/gyp/v8.gyp:801: ['v8_target_arch=="arm" and host_arch=="x64" and
_toolset=="host"', {
I'm not sure how to wrap this line.

[Søren Thygesen Gjesse, 2011-01-04 12:15:06]

On 2011/01/04 11:56:56, Paweł Hajdan Jr. wrote:
> On 2011/01/04 11:39:19, Søren Gjesse wrote:
> > This change is really confusing the differ, but you only added the new outer
> > condition, indented 4 chars and added the targets v8 and v8_shell in the
else
> > part, right?
> 
> Yes.
> 
> > However please format this to be inside the 80 char line length.
> 
> Done where it was trivial. There are two cases where I don't know what to do,
> see below.
> 
> http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp
> File tools/gyp/v8.gyp (right):
> 
> http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp#newcode262
> tools/gyp/v8.gyp:262:
> '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)mksnapshot<(EXECUTABLE_SUFFIX)',
> I'm not sure how to wrap this line.
> 
> http://codereview.chromium.org/6092006/diff/4001/tools/gyp/v8.gyp#newcode801
> tools/gyp/v8.gyp:801: ['v8_target_arch=="arm" and host_arch=="x64" and
> _toolset=="host"', {
> I'm not sure how to wrap this line.

LGTM, we will leave these lines for now.

Committed: http://code.google.com/p/v8/source/detail?r=6153

Thank you for the patch.