Mojo: Enable apps built against the chromium env to be built as shared libraries

mojo/mojo.gyp

 # Copyright 2013 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.
 
 {
   'target_defaults': {
     'conditions': [
       ['mojo_shell_debug_url != ""', {
         'defines': [
           'MOJO_SHELL_DEBUG=1',
           'MOJO_SHELL_DEBUG_URL="<(mojo_shell_debug_url)"',
          ],
       }],
     ],
   },
   'variables': {
     'chromium_code': 1,
     'mojo_shell_debug_url%': "",
+    'conditions': [
+      #
+      # The following mojo_system-prefixed variables are used to express a
+      # dependency on the mojo system APIs.
+      #
+      # In a component build, everything can link against mojo_system_impl
+      # because it is built as a shared library. However, in a non-component
+      # build, mojo_system_impl is linked into an executable (e.g.,
+      # mojo_shell), and must be injected into other shared libraries (i.e.,
+      # Mojo Apps) that need the mojo system API.
+      #
+      # When building a component library, add <(mojo_system_for_component) to
+      # your dependencies section.  When building a loadable module (e.g., a
+      # Mojo App), add <(mojo_system_for_loadable_module) to your dependencies
+      # section.
+      #
+      ['component=="shared_library"', {
+        'mojo_system_for_component': "mojo_system_impl",
+        'mojo_system_for_loadable_module': "mojo_system_impl",
+      }, {
+        'mojo_system_for_component': "mojo_none",
+        'mojo_system_for_loadable_module': "mojo_system",
+      }],
+    ],
   },
   'includes': [
     'mojo_apps.gypi',
     'mojo_examples.gypi',
     'mojo_public.gypi',
     'mojo_services.gypi',
   ],
   'targets': [
     {
       'target_name': 'mojo',
@@ skipping 68 matching lines @@
         }],
         ['OS == "linux"', {
           'dependencies': [
             'mojo_dbus_echo',
             'mojo_dbus_echo_service',
           ],
         }],
       ]
     },
     {
+      'target_name': 'mojo_none',
+      'type': 'none',
+    },
+    {
       'target_name': 'mojo_external_service_bindings',
       'type': 'static_library',
       'sources': [
         'shell/external_service.mojom',
       ],
       'includes': [ 'public/tools/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
         'mojo_cpp_bindings',
       ],
       'dependencies': [
@@ skipping 174 matching lines @@
       'dependencies': [
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../gpu/gpu.gyp:command_buffer_client',
         '../gpu/gpu.gyp:command_buffer_common',
         '../gpu/gpu.gyp:gles2_cmd_helper',
         '../gpu/gpu.gyp:gles2_implementation',
         'mojo_gles2',
         'mojo_gles2_bindings',
         'mojo_environment_chromium',
-        'mojo_system_impl',
+        '<(mojo_system_for_component)',
       ],
       'defines': [
         'MOJO_GLES2_IMPL_IMPLEMENTATION',
       ],
       'sources': [
         'gles2/command_buffer_client_impl.cc',
         'gles2/command_buffer_client_impl.h',
         'gles2/gles2_impl_export.h',
         'gles2/gles2_support_impl.cc',
         'gles2/gles2_support_impl.h',
@@ skipping 15 matching lines @@
     {
       # GN version: //mojo/common
       'target_name': 'mojo_common_lib',
       'type': '<(component)',
       'defines': [
         'MOJO_COMMON_IMPLEMENTATION',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
-        'mojo_system_impl',
+        '<(mojo_system_for_component)',
       ],
       'export_dependent_settings': [
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
-        'mojo_system_impl',
       ],
       'sources': [
         'common/common_type_converters.cc',
         'common/common_type_converters.h',
         'common/data_pipe_utils.cc',
         'common/data_pipe_utils.h',
         'common/handle_watcher.cc',
         'common/handle_watcher.h',
         'common/message_pump_mojo.cc',
         'common/message_pump_mojo.h',
@@ skipping 38 matching lines @@
         'common/handle_watcher_unittest.cc',
         'common/message_pump_mojo_unittest.cc',
         'common/test/multiprocess_test_helper_unittest.cc',
       ],
     },
     {
       # GN version: //mojo/environment:chromium
       'target_name': 'mojo_environment_chromium',
       'type': 'static_library',
       'dependencies': [
-        'mojo_common_lib',
         'mojo_environment_chromium_impl',
       ],
       'sources': [
         'environment/environment.cc',
         # TODO(vtl): This is kind of ugly. (See TODO in logging.h.)
         "public/cpp/environment/logging.h",
         "public/cpp/environment/lib/logging.cc",
       ],
       'include_dirs': [
         '..',
       ],
       'export_dependent_settings': [
         'mojo_environment_chromium_impl',
       ],
     },
     {
       # GN version: //mojo/environment:chromium_impl
       'target_name': 'mojo_environment_chromium_impl',
       'type': '<(component)',
       'defines': [
         'MOJO_ENVIRONMENT_IMPL_IMPLEMENTATION',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
-        'mojo_common_lib'
+        'mojo_common_lib',
+        '<(mojo_system_for_component)',
       ],
       'sources': [
         'environment/default_async_waiter_impl.cc',
         'environment/default_async_waiter_impl.h',
         'environment/default_logger_impl.cc',
         'environment/default_logger_impl.h',
       ],
       'include_dirs': [
         '..',
       ],
     },
     {
       # GN version: //mojo/service_manager
       'target_name': 'mojo_service_manager',
       'type': '<(component)',
       'defines': [
         'MOJO_SERVICE_MANAGER_IMPLEMENTATION',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../net/net.gyp:net',
         '../url/url.gyp:url_lib',
         'mojo_common_lib',
         'mojo_environment_chromium',
         'mojo_service_provider_bindings',
-        'mojo_system_impl',
+        '<(mojo_system_for_component)',
       ],
       'sources': [
         'service_manager/background_service_loader.cc',
         'service_manager/background_service_loader.h',
         'service_manager/service_loader.h',
         'service_manager/service_manager.cc',
         'service_manager/service_manager.h',
         'service_manager/service_manager_export.h',
       ],
       'export_dependent_settings': [
@@ skipping 21 matching lines @@
     {
       'target_name': 'mojo_shell_lib',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../base/base.gyp:base_static',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../net/net.gyp:net',
         '../url/url.gyp:url_lib',
         'mojo_application',
+        'mojo_common_lib',
         'mojo_external_service_bindings',
         'mojo_gles2_impl',
         'mojo_native_viewport_service',
         'mojo_network_bindings',
         'mojo_profile_service',
         'mojo_service_manager',
         'mojo_service_provider_bindings',
         'mojo_spy',
         'mojo_system_impl',
       ],
@@ skipping 491 matching lines @@
             'views/views_init_internal.h',
           ],
           'defines': [
             'MOJO_VIEWS_IMPLEMENTATION',
           ],
         },
       ],
     }],
   ],
 }