Bug 1306021 - Remove unneeded R.java copies to reduce field wastage r=nalexander

MozReview-Commit-ID: GHYCqzaMaGe

--HG--
extra : amend_source : bf65ed253bcc353c7fb77fa5029d85e862695491

mobile/android/base/Makefile.in

@@ -402,21 +402,30 @@ all_resources = \
 
 generated/org/mozilla/gecko/R.java: .aapt.deps ;
 
+# Only add libraries that contain resources here. We (unecessarily) generate an identical R.java which
+# is copied into each of these locations, and each of these files contains thousands of fields.
+# Each unnecessary copy therefore wastes unnecessary fields in the output dex file.
+# Note: usually proguard will help clean this up after the fact, but having too many fields will cause
+# dexing to fail, regardless of any later optimisations proguard could later make to bring us back
+# under the limit.
+# Ideally we would fix our aapt invocations to correctly generate minimal copies of R.java for each
+# package, but that seems redundant since gradle builds are able to correctly generate these files.
+
 # If native devices are enabled, add Google Play Services, build their resources
-generated/android/support/v4/R.java: .aapt.deps ;
+# (no resources) generated/android/support/v4/R.java: .aapt.deps ;
 generated/android/support/v7/appcompat/R.java: .aapt.deps ;
 generated/android/support/v7/cardview/R.java: .aapt.deps ;
 generated/android/support/design/R.java: .aapt.deps ;
 generated/android/support/v7/mediarouter/R.java: .aapt.deps ;
 generated/android/support/v7/recyclerview/R.java: .aapt.deps ;
-generated/android/support/customtabs/R.java: .aapt.deps ;
-generated/android/support/v7/palette/R.java: .aapt.deps ;
+# (no resources) generated/android/support/customtabs/R.java: .aapt.deps ;
+# (no resources) generated/android/support/v7/palette/R.java: .aapt.deps ;
 generated/com/google/android/gms/R.java: .aapt.deps ;
 generated/com/google/android/gms/ads/R.java: .aapt.deps ;
 generated/com/google/android/gms/base/R.java: .aapt.deps ;
 generated/com/google/android/gms/cast/R.java: .aapt.deps ;
-generated/com/google/android/gms/gcm/R.java: .aapt.deps ;
-generated/com/google/android/gms/measurement/R.java: .aapt.deps ;
+# (no resources) generated/com/google/android/gms/gcm/R.java: .aapt.deps ;
+# (no resources) generated/com/google/android/gms/measurement/R.java: .aapt.deps ;
 
 gecko.ap_: .aapt.deps ;
 R.txt: .aapt.deps ;

mobile/android/base/moz.build

@@ -62,7 +62,7 @@ resjar.generated_sources += [
 if CONFIG['ANDROID_SUPPORT_V4_AAR']:
     ANDROID_EXTRA_PACKAGES += ['android.support.v4']
     ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_SUPPORT_V4_AAR_RES']]
-    resjar.generated_sources += ['android/support/v4/R.java']
+# (no resources) resjar.generated_sources += ['android/support/v4/R.java']
 if CONFIG['ANDROID_APPCOMPAT_V7_AAR']:
     ANDROID_EXTRA_PACKAGES += ['android.support.v7.appcompat']
     ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_APPCOMPAT_V7_AAR_RES']]
@@ -82,12 +82,11 @@ if CONFIG['ANDROID_RECYCLERVIEW_V7_AAR']:
 if CONFIG['ANDROID_CUSTOMTABS_AAR']:
     ANDROID_EXTRA_PACKAGES += ['android.support.customtabs']
     ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_CUSTOMTABS_AAR_RES']]
-    resjar.generated_sources += ['android/support/customtabs/R.java']
+# (no resources) resjar.generated_sources += ['android/support/customtabs/R.java']
 if CONFIG['ANDROID_PALETTE_V7_AAR']:
     ANDROID_EXTRA_PACKAGES += ['android.support.v7.palette']
     ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_PALETTE_V7_AAR_RES']]
-    resjar.generated_sources += ['android/support/v7/palette/R.java']
-
+# (no resources) resjar.generated_sources += ['android/support/v7/palette/R.java']
 
 resjar.javac_flags += ['-Xlint:all']
 
@@ -880,12 +879,12 @@ if CONFIG['MOZ_ANDROID_GCM']:
     if CONFIG['ANDROID_PLAY_SERVICES_GCM_AAR']:
         ANDROID_EXTRA_PACKAGES += ['com.google.android.gms.gcm']
         ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_PLAY_SERVICES_GCM_AAR_RES']]
-        resjar.generated_sources += ['com/google/android/gms/gcm/R.java']
+# (no resources) resjar.generated_sources += ['com/google/android/gms/gcm/R.java']
 
     if CONFIG['ANDROID_PLAY_SERVICES_MEASUREMENT_AAR']:
         ANDROID_EXTRA_PACKAGES += ['com.google.android.gms.measurement']
         ANDROID_EXTRA_RES_DIRS += ['%' + CONFIG['ANDROID_PLAY_SERVICES_MEASUREMENT_AAR_RES']]
-        resjar.generated_sources += ['com/google/android/gms/measurement/R.java']
+# (no resources) resjar.generated_sources += ['android/support/v7/palette/R.java']
 
 if CONFIG['MOZ_INSTALL_TRACKING']:
     gbjar.extra_jars += [