Build services as standalone executables

services/service_manager/public/cpp/service.gni

 # 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.
 
 import("//build/toolchain/toolchain.gni")
 import("//services/service_manager/public/constants.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
   import("//build/config/zip.gni")
 }
 
 # Generates a Service "package", which includes:
-# . A self-named subdirectory
-# . A binary .library
-# . A resources subdirectory alongside .library that contains the contents of
-#   "resources"
 #
-# The parameters of this template are those of a shared library.
+#   - A self-named subdirectory
+#   - A binary .service executable
+#   - A resources subdirectory alongside the executable, which contains the
+#     contents of "resources"
+#
+# The parameters of this template are those of an executable
 template("service") {
   base_target_name = target_name
   if (defined(invoker.output_name)) {
     base_target_name = invoker.output_name
   }
 
   final_target_name = target_name
 
-  library_deps = []
+  service_deps = []
   if (defined(invoker.deps)) {
-    library_deps += invoker.deps
+    service_deps += invoker.deps
   }
 
-  library_data_deps = []
+  service_data_deps =
+      [ "//services/service_manager/public/cpp/standalone_service:main" ]
 
   if (defined(invoker.resources)) {
     copy_step_name = "${base_target_name}__copy_resources"
     copy(copy_step_name) {
       sources = invoker.resources
       outputs = [
         "${root_out_dir}/${packages_directory}/${base_target_name}/resources/{{source_file_part}}",
       ]
       if (defined(invoker.testonly)) {
         testonly = invoker.testonly
       }
-      deps = library_deps
+      deps = service_deps
     }
-    library_data_deps += [ ":$copy_step_name" ]
+    service_data_deps += [ ":$copy_step_name" ]
   }
 
-  output = base_target_name + ".library"
-  library_target_name = base_target_name + "_library"
-  library_name = "${shlib_prefix}${library_target_name}${shlib_extension}"
+  if (defined(invoker.data_deps)) {
+    service_data_deps += invoker.data_deps
+  }
 
-  shared_library(library_target_name) {
+  executable_target_name = base_target_name + "_executable"
+  executable_name = base_target_name + ".service"
+
+  executable(executable_target_name) {
+    output_name = base_target_name
+    output_extension = "service"
+
     if (defined(invoker.cflags)) {
       cflags = invoker.cflags
     }
     if (defined(invoker.cflags_c)) {
       cflags_c = invoker.cflags_c
     }
     if (defined(invoker.cflags_cc)) {
       cflags_cc = invoker.cflags_cc
     }
     if (defined(invoker.cflags_objc)) {
@@ skipping 11 matching lines @@
     if (defined(invoker.ldflags)) {
       ldflags = invoker.ldflags
     }
     if (defined(invoker.lib_dirs)) {
       lib_dirs = invoker.lib_dirs
     }
     if (defined(invoker.libs)) {
       libs = invoker.libs
     }
 
-    data_deps = []
-    if (!defined(invoker.avoid_runner_cycle) || !invoker.avoid_runner_cycle) {
-      # Give the user an out; as some Services are depended on by the runner.
-      data_deps += [ "//services/service_manager/standalone" ]
-    }
-    if (defined(invoker.data_deps)) {
-      data_deps += invoker.data_deps
-    }
-    data_deps += library_data_deps
+    data_deps = service_data_deps
 
     deps = [
-      "//mojo/public/c/system:set_thunks_for_app",
-      "//services/service_manager/public/cpp:application_support",
+      "//services/service_manager/public/cpp/standalone_service:main",
     ]
 
-    deps += library_deps
+    deps += service_deps
     if (defined(invoker.public_deps)) {
       public_deps = invoker.public_deps
     }
     if (defined(invoker.all_dependent_configs)) {
       all_dependent_configs = invoker.all_dependent_configs
     }
     if (defined(invoker.public_configs)) {
       public_configs = invoker.public_configs
     }
     if (defined(invoker.check_includes)) {
@@ skipping 19 matching lines @@
     }
   }
 
   copy(final_target_name) {
     forward_variables_from(invoker,
                            [
                              "testonly",
                              "visibility",
                            ])
     deps = [
-      ":${library_target_name}",
+      ":${executable_target_name}",
     ]
 
+    # NOTE: We have to explicitly inherit the same data_deps as the executable
+    # target itself, rather than specifying a data depenedency on the executable
+    # target. This avoids needless duplication of service binary artifacts in
+    # test isolates, as the executable is unused in its original location.
+    data_deps = service_data_deps
+
     sources = [
-      "${root_shlib_dir}/${library_name}",
+      "${root_out_dir}/${executable_name}",
     ]
     outputs = [
-      "${root_out_dir}/${packages_directory}/${base_target_name}/${output}",
+      "${root_out_dir}/${packages_directory}/${base_target_name}/${executable_name}",
     ]
   }
 }