Enable cmake builds to (optionally) use ninja

Enable cmake builds to (optionally) use ninja

For now just switch libgit2 to ninja.  Hopefully
we can switch to ninja by default at some point.

R=binji@chromium.org

Committed: https://code.google.com/p/naclports/source/detail?r=1647

[Sam Clegg, 2014-09-08 20:18:15]

sbc@chromium.org changed reviewers:
+ binji@chromium.org

[binji, 2014-09-08 20:43:18]

lgtm, I guess.

Why switch to ninja for cmake builds? I thought it was still experimental.

Also, this requires us to have ninja installed and a recent enough cmake. You
should update the README if you go through with this change.

https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh
File build_tools/common.sh (right):

https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh#newcod...
build_tools/common.sh:1109: if [ "${CMAKE_USE_NINJA:-}" = "1" -a -f build.ninja
]; then
Seems like this should fail when using CMAKE_USE_NINJA if build.ninja doesn't
exist. Rather than falling through to running make.

https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh#newcod...
build_tools/common.sh:1113: LogExecute ninja ${NINJA_ARGS:-}
MAKE_TARGETS?

or is it assumed that if you are using CMAKE_USE_NINJA that you'll set
NINJA_ARGS instead? Maybe NINJA_TARGETS instead?

[Sam Clegg, 2014-09-08 20:56:31]

On 2014/09/08 20:43:18, binji wrote:
> lgtm, I guess.
> 
> Why switch to ninja for cmake builds? I thought it was still experimental.

Ok, you are right.  Although I think a lot of large projects rely on the ninja
generator now (at least qt does I think).

I've made it so that we always use the make build by default, but one can use
ninja if you prefer by setting CMAKE_USE_NINJA in your local environment.

> 
> Also, this requires us to have ninja installed and a recent enough cmake. You
> should update the README if you go through with this change.
> 
> https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh
> File build_tools/common.sh (right):
> 
>
https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh#newcod...
> build_tools/common.sh:1109: if [ "${CMAKE_USE_NINJA:-}" = "1" -a -f
build.ninja
> ]; then
> Seems like this should fail when using CMAKE_USE_NINJA if build.ninja doesn't
> exist. Rather than falling through to running make.

Done.

> 
>
https://codereview.chromium.org/553973003/diff/1/build_tools/common.sh#newcod...
> build_tools/common.sh:1113: LogExecute ninja ${NINJA_ARGS:-}
> MAKE_TARGETS?
> 
> or is it assumed that if you are using CMAKE_USE_NINJA that you'll set
> NINJA_ARGS instead? Maybe NINJA_TARGETS instead?

Done.

[binji, 2014-09-08 20:59:19]

On 2014/09/08 20:56:31, Sam Clegg wrote:
> On 2014/09/08 20:43:18, binji wrote:
> > lgtm, I guess.
> > 
> > Why switch to ninja for cmake builds? I thought it was still experimental.
> 
> Ok, you are right.  Although I think a lot of large projects rely on the ninja
> generator now (at least qt does I think).
> 
> I've made it so that we always use the make build by default, but one can use
> ninja if you prefer by setting CMAKE_USE_NINJA in your local environment.

OK, that seems good to me.

[Sam Clegg, 2014-09-09 22:06:24]

Committed patchset #4 (id:60001) manually as 1647 (tree was closed).