GN: make relocation packing work

tools/relocation_packer/relocation_packer.gyp

 # 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.
 
 {
   'variables': {
     'target_define%': 'TARGET_UNSUPPORTED',
     'conditions': [
       [ 'target_arch == "arm"', {
         'target_define': 'TARGET_ARM',
       }],
       [ 'target_arch == "arm64"', {
         'target_define': 'TARGET_ARM64',
       }],
     ],
   },
   'targets': [
     {
+      # GN: //tools/relocation_packer:lib_relocation_packer
       'target_name': 'lib_relocation_packer',
       'toolsets': ['host'],
       'type': 'static_library',
       'defines': [
         '<(target_define)',
       ],
       'dependencies': [
         '../../third_party/elfutils/elfutils.gyp:libelf',
       ],
       'sources': [
         'src/debug.cc',
         'src/delta_encoder.cc',
         'src/elf_file.cc',
         'src/leb128.cc',
         'src/packer.cc',
         'src/sleb128.cc',
         'src/run_length_encoder.cc',
       ],
     },
     {
+      # GN: //tools/relocation_packer:relocation_packer
       'target_name': 'relocation_packer',
       'toolsets': ['host'],
       'type': 'executable',
       'defines': [
         '<(target_define)',
       ],
       'dependencies': [
         '../../third_party/elfutils/elfutils.gyp:libelf',
         'lib_relocation_packer',
       ],
       'sources': [
         'src/main.cc',
       ],
     },
     {
+      # GN: //tools/relocation_packer:relocation_packer_unittests
       'target_name': 'relocation_packer_unittests',
       'toolsets': ['host'],
       'type': 'executable',
       'defines': [
         '<(target_define)',
       ],
       'cflags': [
         '-DINTERMEDIATE_DIR="<(INTERMEDIATE_DIR)"',
       ],
       'dependencies': [
@@ skipping 27 matching lines @@
     },
 
     # Targets to build test data.  These participate only in building test
     # data for use with elf_file_unittest.cc, and are not part of the main
     # relocation packer build.  Unit test data files are checked in to the
     # source tree as 'golden' data, and are not generated 'on the fly' by
     # the build.
     #
     # See test_data/generate_elf_file_unittest_relocs.sh for instructions.
     {
+      # GN: //tools/relocation_packer:relocation_packer_test_data
       'target_name': 'relocation_packer_test_data',
       'toolsets': ['target'],
       'type': 'shared_library',
       'cflags': [
         '-O0',
         '-g0',
       ],
       'sources': [
         'test_data/elf_file_unittest_relocs.cc',
       ],
     },
     {
+      # GN: //tools/relocation_packer:relocation_packer_unittests_test_data
       'target_name': 'relocation_packer_unittests_test_data',
       'toolsets': ['target'],
       'type': 'none',
       'actions': [
         {
           'variables': {
             'test_file': '<(SHARED_LIB_DIR)/librelocation_packer_test_data.so',
             'conditions': [
               [ 'target_arch == "arm"', {
                 'added_section': '.android.rel.dyn',
@@ skipping 24 matching lines @@
               '--added-section=<(added_section)',
               '--test-file=<(test_file)',
               '--unpacked-output=<(INTERMEDIATE_DIR)/<(unpacked_output)',
               '--packed-output=<(INTERMEDIATE_DIR)/<(packed_output)',
           ],
         },
       ],
     },
   ],
 }