Add gyp machinery to build with packed ARM relative relocations.

build/android/pack_arm_relocations.gypi

Index: build/android/pack_arm_relocations.gypi
diff --git a/build/android/pack_arm_relocations.gypi b/build/android/pack_arm_relocations.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..1e387a7c08eb57468191fa827eab3855e3dce094
--- /dev/null
+++ b/build/android/pack_arm_relocations.gypi
@@ -0,0 +1,76 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This file is meant to be included into an action to provide a rule that
+# packs ARM relative relocations in native libraries.
+#
+# To use this, create a gyp target with the following form:
+#  {
+#    'action_name': 'pack_arm_relocations',
+#    'actions': [
+#      'variables': {
+#        'enable_packing': 'pack relocations if 1, plain file copy if 0'
+#        'suppress_packing': 'names of libraries explicitly not packed',

[rmcilroy, 2014/07/01 11:13:03]

nit - 'suppress_packing' sounds like the opposite of the enable_packing flag. 
How about 'exclude_packing_list'?  Update here and in the python tool.

[simonb (inactive), 2014/07/01 14:20:29]

Done.

+#        'ordered_libraries_file': 'file generated by write_ordered_libraries'
+#        'input_paths': 'files to be added to the list of inputs'
+#        'stamp': 'file to touch when the action is complete'
+#        'stripped_libraries_dir': 'directory holding stripped libraries',
+#        'packed_libraries_dir': 'directory holding packed libraries',
+#      'includes': [ '../../build/android/pack_arm_relocations.gypi' ],
+#    ],
+#  },
+#
+
+{
+  'variables': {
+    'input_paths': [],
+  },
+  'inputs': [
+    '<(DEPTH)/build/android/gyp/util/build_utils.py',
+    '<(DEPTH)/build/android/gyp/pack_arm_relocations.py',
+    '<(ordered_libraries_file)',
+    '>@(input_paths)',
+  ],
+  'outputs': [
+    '<(stamp)',
+  ],
+  'conditions': [
+    ['enable_packing == 1', {
+      'message': 'Packing ARM relative relocations for <(_target_name)',
+      'dependencies': [
+        '<(DEPTH)/tools/relocation_packer/relocation_packer.gyp:relocation_packer#host',
+      ],
+      'inputs': [
+        '<(PRODUCT_DIR)/relocation_packer',
+      ],
+      'action': [
+        'python', '<(DEPTH)/build/android/gyp/pack_arm_relocations.py',
+        '--enable-packing=1',
+        '--suppress-packing=<@(suppress_packing)',
+        '--android-pack-relocations=<(PRODUCT_DIR)/relocation_packer',
+        '--android-objcopy=<(android_objcopy)',
+        '--stripped-libraries-dir=<(stripped_libraries_dir)',
+        '--packed-libraries-dir=<(packed_libraries_dir)',
+        '--libraries-file=<(ordered_libraries_file)',
+        '--stamp=<(stamp)',
+      ],
+    }, {
+      'message': 'Copying libraries (no relocation packing) for <(_target_name)',
+      'action': [
+        'python', '<(DEPTH)/build/android/gyp/pack_arm_relocations.py',
+        '--enable-packing=0',
+        '--stripped-libraries-dir=<(stripped_libraries_dir)',
+        '--packed-libraries-dir=<(packed_libraries_dir)',
+        '--libraries-file=<(ordered_libraries_file)',
+        '--stamp=<(stamp)',
+      ],
+    }],
+    ['component == "shared_library"', {
+      # Add a fake output to force the build to always re-run this step. This
+      # is required because the real inputs are not known at gyp-time and
+      # changing base.so may not trigger changes to dependent libraries.
+      'outputs': [ '<(stamp).fake' ]
+    }],
+  ],
+}