android: Add a way to override build system variables.

android: Add a way to override build system variables.

Add a key 'aosp_build_settings' which a target can use to set Android
build system variables in the generated makefile, for edge cases not
directly supported by gyp. aosp_build_settings is a dictionary which
maps variable names to values (values may be integers, strings or lists;
all values will be quoted appropriately for make and lists will be
converted to whitespace-separated form).

BUG=
R=primiano@chromium.org, thakis@chromium.org

Committed: https://code.google.com/p/gyp/source/detail?r=1977

[Torne, 2014-09-12 10:55:27]

torne@chromium.org changed reviewers:
+ primiano@chromium.org

[Torne, 2014-09-12 10:57:22]

This is intended to replace the need for
https://codereview.chromium.org/509383002/ by allowing the chromium gyp files to
just specify which targets should set LOCAL_FDO_SUPPORT in the generated
makefiles. It's similar to xcode_settings or msbuild_settings.

We hopefully won't need to use this mechanism often but it seems preferable to
modifying the generator and adding custom gyp settings for every little thing.

[Primiano Tucci (use gerrit), 2014-09-12 12:22:53]

LGTM

>We hopefully won't need to use this mechanism often but it seems preferable to
modifying the generator and adding custom gyp settings for every little thing.

Totally agree

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android.py
File pylib/gyp/generator/android.py (right):

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android....
pylib/gyp/generator/android.py:854: settings =
spec.get('android_build_settings', {})
Are you deliberately emitting this before all the LOCAL_ ... makefile stuff? I
thought you planned to emit the overrides after.

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android....
pylib/gyp/generator/android.py:856: self.WriteLn('### Manually overridden build
settings')
I'd mention android_build_settings here.
Reading that in a .mk would make me feel as if somebody manually hacked the
makefile.

[Torne, 2014-09-12 13:13:04]

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android.py
File pylib/gyp/generator/android.py (right):

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android....
pylib/gyp/generator/android.py:854: settings =
spec.get('android_build_settings', {})
On 2014/09/12 12:22:52, Primiano Tucci wrote:
> Are you deliberately emitting this before all the LOCAL_ ... makefile stuff? I
> thought you planned to emit the overrides after.

This is at the end; this is the function that emits the final "include
$(BUILD_STATIC_LIBRARY)" or whichever.

https://codereview.chromium.org/565743004/diff/1/pylib/gyp/generator/android....
pylib/gyp/generator/android.py:856: self.WriteLn('### Manually overridden build
settings')
On 2014/09/12 12:22:52, Primiano Tucci wrote:
> I'd mention android_build_settings here.
> Reading that in a .mk would make me feel as if somebody manually hacked the
> makefile.

Yeah, good point, I'll change it.

[Torne, 2014-09-12 13:36:19]

Fixed comment to be more specific.

[Torne, 2014-09-12 15:01:54]

torne@chromium.org changed reviewers:
+ thakis@chromium.org

[Torne, 2014-09-12 15:01:54]

Nico, does this seem like a terrible idea? :)

[Nico, 2014-09-12 15:15:27]

I think this is fine, but I'd give it a different name. Most people will think
that this is for chrome/android with the current name.

[Torne, 2014-09-12 15:20:54]

I'm not sure what name would make that more clear really. The generator has been
called "android" the whole time and that in itself is somewhat confusing :)

Anyone got a suggestion?

[Primiano Tucci (use gerrit), 2014-09-12 15:36:20]

> Most people will think this is for chrome/android with the current name.
Yeah actually that's true if you think to that from the gyp (files) side. Seeing
'android_build_settings' in the gyp files might feel confusing to Chrome for
Android folks.

> Anyone got a suggestion?
What about android_makefile_overrides / android_mk_overrides /
android_generator_overrides? It might make it less ambiguous WDYT?

[Torne, 2014-09-12 15:46:45]

Renamed to "aosp_build_settings". It makes a reasonable amount of sense from the
chromium side as the android_aosp bot builds it. Hopefully we can deprecate this
whole thing before too much longer and not worry about it any more :)

[Nico, 2014-09-12 16:02:05]

lgtm

[Torne, 2014-09-12 16:06:30]

Committed patchset #3 (id:40001) manually as 1977 (presubmit successful).