Don't set up environment for ninja if the compiler is already available

Don't set up environment for ninja if the compiler is already available

Previously when ninja.bat was run from a prompt that already had VS vars
available, it was adding them a second time. Depending on what else the user
had in the path, this could cause the path to become too long and so things at
the end wouldn't be found. To avoid this, check if the compiler is available
first, and don't run the environment set up in that case.

R=maruel@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=133940

[Wez, 2012-04-25 17:48:36]

LGTM, FWIW. :)

[Marc-Antoine Ruel (Google), 2012-04-25 17:55:49]

https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat
File ninja.bat (right):

https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat#newcode34
ninja.bat:34: if %errorlevel% EQU 0 goto no_set_env
back in my days I would have written
if not errorlevel 1 goto :not_set_env

https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat#newcode43
ninja.bat:43: endlocal & set PATH=%PATH% & set INCLUDE=%INCLUDE% & set
LIBPATH=%LIBPATH% & set LIB=%LIB%
nice construct, never thought about doing that. But don't you want to goto <line
53> right after?

[scottmg, 2012-04-25 18:09:40]

On 2012/04/25 17:55:49, Marc-Antoine Ruel (Google) wrote:
> https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat
> File ninja.bat (right):
> 
> https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat#newcode34
> ninja.bat:34: if %errorlevel% EQU 0 goto no_set_env
> back in my days I would have written
> if not errorlevel 1 goto :not_set_env

Done. Better to avoid %errorlevel% I guess? I don't know... batch scripting
makes my head hurt. :)

> 
> https://chromiumcodereview.appspot.com/10222010/diff/1/ninja.bat#newcode43
> ninja.bat:43: endlocal & set PATH=%PATH% & set INCLUDE=%INCLUDE% & set
> LIBPATH=%LIBPATH% & set LIB=%LIB%
> nice construct, never thought about doing that. But don't you want to goto
<line
> 53> right after?

No, I still need to add python and avoid running this script next time. So, if
there's no compiler in the path, we add the compiler, and then add python+ninja.
If the compiler was found, then only add python+ninja.

[M-A Ruel, 2012-04-25 18:14:43]

lgtm

https://chromiumcodereview.appspot.com/10222010/diff/3/ninja.bat
File ninja.bat (right):

https://chromiumcodereview.appspot.com/10222010/diff/3/ninja.bat#newcode51
ninja.bat:51: endlocal & set PATH=%~dp0python_bin;%~dp0ninja-win;%PATH%
Ah, I guess this endlocal is a no-op because there wasn't an equivalent setlocal
for this one when the one at line 43 is executed.

Dirty dirty batch files.

[scottmg, 2012-04-25 18:19:54]

On 2012/04/25 18:14:43, Marc-Antoine Ruel wrote:
> lgtm
> 
> https://chromiumcodereview.appspot.com/10222010/diff/3/ninja.bat
> File ninja.bat (right):
> 
> https://chromiumcodereview.appspot.com/10222010/diff/3/ninja.bat#newcode51
> ninja.bat:51: endlocal & set PATH=%~dp0python_bin;%~dp0ninja-win;%PATH%
> Ah, I guess this endlocal is a no-op because there wasn't an equivalent
setlocal
> for this one when the one at line 43 is executed.
> 
> Dirty dirty batch files.

Yeah, although now that you mention it, there's no reason not to re-open a
setlocal when falling through. Added that.

[M-A Ruel, 2012-04-25 18:22:21]

lgtm

[commit-bot: I haz the power, 2012-04-25 18:22:28]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/10222010/8002

[commit-bot: I haz the power, 2012-04-25 18:22:30]

Can't apply patch for file depot_tools/ninja.bat.
While running patch -p0 --forward --force;
patching file depot_tools/ninja.bat
Hunk #1 FAILED at 25.
1 out of 1 hunk FAILED -- saving rejects to file depot_tools/ninja.bat.rej

[M-A Ruel, 2012-04-25 18:36:36]

On 2012/04/25 18:22:30, I haz the power (commit-bot) wrote:
> Can't apply patch for file depot_tools/ninja.bat.

Ah right, please commit manually.