GN: make relocation packing work

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 2bb432d4dc888710365a8c4254d65fb5facd5e52..c71ec56adbb939090a91aaafa6e7459d91ab16db 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -8,7 +8,6 @@ import("//tools/grit/grit_rule.gni")
 
 assert(is_android)
 
-
 # Declare a jni target
 #
 # This target generates the native jni bindings for a set of .java files.
@@ -986,19 +985,53 @@ template("android_apk") {
   }
 
   if (_native_libs != []) {
-    copy_ex("${_template_name}__prepare_native") {
-      clear_dir = true
+    action("${_template_name}__prepare_native") {
+      script = "//build/android/gyp/pack_arm_relocations.py"
+      packed_libraries_dir = "$_native_libs_dir/$android_app_abi"
+      depfile = "$target_gen_dir/$target_name.d"
+      outputs = [
+        depfile
+      ]
       inputs = [
         build_config
       ]
-      dest = "$_native_libs_dir/$android_app_abi"
+      relocation_packer_target = "//tools/relocation_packer($host_toolchain)"
+      deps = [
+        relocation_packer_target
+      ]
+      skip_packing_list = [
+        "gdbserver",
+        "libchromium_android_linker.so",
+      ]
+
+      has_relocations_with_addends = 0

[simonb (inactive), 2014/10/17 12:30:20]

Should be 0 for arm, 1 for arm64.

[cjhopman, 2014/10/17 20:55:19]

Done. This is in //tools/relocation_packer/config.gni

+      relocation_packer_dir = get_label_info(
+          "$relocation_packer_target", "root_out_dir")
+      relocation_packer_exe = "${relocation_packer_dir}/relocation_packer"
+      enable_packing = false

[simonb (inactive), 2014/10/17 12:30:20]

Always false?  (How is packing turned on?  It is now on in clank.gyp.)

[cjhopman, 2014/10/17 20:55:19]

Done.

+      enable_packing_arg = 0
+      if (enable_packing) {
+        enable_packing_arg = 1
+      }
+
       args = [
-        "--files=@FileArg(${_rebased_build_config}:native:libraries)",
+        "--depfile", rebase_path(depfile, root_build_dir),
+        "--enable-packing=$enable_packing_arg",
+        "--has-relocations-with-addends=$has_relocations_with_addends",
+        "--exclude-packing-list=$skip_packing_list",
+        "--android-pack-relocations", rebase_path(relocation_packer_exe, root_build_dir),
+        "--android-objcopy", rebase_path(android_objcopy, root_build_dir),
+        "--stripped-libraries-dir", rebase_path(root_build_dir, root_build_dir),
+        "--packed-libraries-dir", rebase_path(packed_libraries_dir, root_build_dir),
+        "--libraries=@FileArg(${_rebased_build_config}:native:libraries)",
+        "--clear-dir"
       ]
+
       if (is_debug) {
-        rebased_gdbserver = rebase_path(android_gdbserver, root_build_dir)
+        rebased_gdbserver = rebase_path([ android_gdbserver ], root_build_dir)

[simonb (inactive), 2014/10/17 12:30:20]

This seems unconnected with relocation packing work.  Part of a different
change?

[cjhopman, 2014/10/17 20:55:19]

We want gdbserver in the native libraries directory for debug builds.
pack_arm_relocations.py sets up that directory for us, and so we tell it to
include gdbserver here. It's in the skip_packing_list above so it will always
just copy it.

+        inputs += [ android_gdbserver ]
         args += [
-          "--files=[\"$rebased_gdbserver\"]"
+          "--libraries=$rebased_gdbserver"
         ]
       }
     }