android: Add a way to override build system variables.

pylib/gyp/generator/android.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Notes:
 #
 # This generates makefiles suitable for inclusion into the Android build system
 # via an Android.mk file. It is based on make.py, the standard makefile
 # generator.
 #
@@ skipping 32 matching lines @@
 }
 
 # Make supports multiple toolsets
 generator_supports_multiple_toolsets = True
 
 
 # Generator-specific gyp specs.
 generator_additional_non_configuration_keys = [
     # Boolean to declare that this target does not want its name mangled.
     'android_unmangled_name',
+    # Map of android build system variables to set.
+    'android_build_settings',
 ]
 generator_additional_path_sections = []
 generator_extra_sources_for_rules = []
 
 
 ALL_MODULES_FOOTER = """\
 # "gyp_all_modules" is a concatenation of the "gyp_all_modules" targets from
 # all the included sub-makefiles. This is just here to clarify.
 gyp_all_modules:
 """
@@ skipping 779 matching lines @@
     deps, link_deps: dependency lists; see ComputeDeps()
     part_of_all: flag indicating this target is part of 'all'
     write_alias_target: flag indicating whether to create short aliases for this
                         target
     """
     self.WriteLn('### Rules for final target.')
 
     if self.type != 'none':
       self.WriteTargetFlags(spec, configs, link_deps)
 
+    settings = spec.get('android_build_settings', {})

[Primiano Tucci (use gerrit), 2014/09/12 12:22:52]

Are you deliberately emitting this before all the LOCAL_ ... makefile stuff? I
thought you planned to emit the overrides after.

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

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

+    if settings:
+      self.WriteLn('### Manually overridden build settings')

[Primiano Tucci (use gerrit), 2014/09/12 12:22:52]

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]

Yeah, good point, I'll change it.

+      for k, v in settings.iteritems():
+        if isinstance(v, list):
+          self.WriteList(v, k)
+        else:
+          self.WriteLn('%s := %s' % (k, make.QuoteIfNecessary(v)))
+      self.WriteLn('')
+
     # Add to the set of targets which represent the gyp 'all' target. We use the
     # name 'gyp_all_modules' as the Android build system doesn't allow the use
     # of the Make target 'all' and because 'all_modules' is the equivalent of
     # the Make target 'all' on Android.
     if part_of_all and write_alias_target:
       self.WriteLn('# Add target alias to "gyp_all_modules" target.')
       self.WriteLn('.PHONY: gyp_all_modules')
       self.WriteLn('gyp_all_modules: %s' % self.android_module)
       self.WriteLn('')
 
@@ skipping 227 matching lines @@
   # Write out the sorted list of includes.
   root_makefile.write('\n')
   for include_file in sorted(include_list):
     root_makefile.write('include $(LOCAL_PATH)/' + include_file + '\n')
   root_makefile.write('\n')
 
   if write_alias_targets:
     root_makefile.write(ALL_MODULES_FOOTER)
 
   root_makefile.close()