Linux: Detect host g++ version as well as target g++ version.

Linux: Detect host g++ version as well as target g++ version.

BUG=360082
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=265572

[Lei Zhang, 2014-04-22 21:51:49]

I got hit with https://crbug.com/365035 ... how could gcc be 46 when the
gcc_version variable is 48? Turns out the host compiler can be Precise's gcc and
the target compiler can be something set up by the CrOS SDK.

[Nico, 2014-04-22 21:55:56]

Bleh, this is terrible. We'd then also set different compiler flags for host and
target, etc.

Can't really think of anything better though, so lgtm I suppose :-(

[mithro-old, 2014-04-23 02:19:17]

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version.py
File build/compiler_version.py (right):

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:34: tool not in ('assembler', 'compiler', 'linker')):
Could just raise an exception here...

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:41: and finally falling back to a default value."""
Technically the first line description should fit inside the 80 characters.

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:124: # exit. The preferences and fallback order is a
close approximation of
s/exit/exist/

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:131: environments = new_environments
environments = ['CXX_host'] + environments

[Lei Zhang, 2014-04-23 02:33:29]

See patch set 2.

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version.py
File build/compiler_version.py (right):

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:34: tool not in ('assembler', 'compiler', 'linker')):
On 2014/04/23 02:19:17, mithro wrote:
> Could just raise an exception here...

I want main() to be able to run Usage() instead.

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:41: and finally falling back to a default value."""
On 2014/04/23 02:19:17, mithro wrote:
> Technically the first line description should fit inside the 80 characters.

I copied this out of gyp. Shortened the comment a little.

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:124: # exit. The preferences and fallback order is a
close approximation of
On 2014/04/23 02:19:17, mithro wrote:
> s/exit/exist/

Done.

https://codereview.chromium.org/247623003/diff/120001/build/compiler_version....
build/compiler_version.py:131: environments = new_environments
On 2014/04/23 02:19:17, mithro wrote:
> environments = ['CXX_host'] + environments

Done.

[mithro-old, 2014-04-23 02:37:12]

lgtm

[Lei Zhang, 2014-04-23 02:37:29]

The CQ bit was checked by thestig@chromium.org

[commit-bot: I haz the power, 2014-04-23 02:38:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/thestig@chromium.org/247623003/140001

[commit-bot: I haz the power, 2014-04-23 08:20:19]

Change committed as 265572