GN: Introduce templates.

webrtc/build/webrtc.gni

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/mips.gni")
 import("//build_overrides/webrtc.gni")
+import("//testing/test.gni")
 
 declare_args() {
   # Disable this to avoid building the Opus audio codec.
   rtc_include_opus = true
 
   # Disable to use absolute header paths for some libraries.
   rtc_relative_path = true
 
   # Used to specify an external Jsoncpp include path when not compiling the
   # library that comes with WebRTC (i.e. rtc_build_json == 0).
@@ skipping 114 matching lines @@
 declare_args() {
   # Include the iLBC audio codec?
   rtc_include_ilbc = !(build_with_chromium || build_with_mozilla)
 }
 
 # Make it possible to provide custom locations for some libraries (move these
 # up into declare_args should we need to actually use them for the GN build).
 rtc_libvpx_dir = "//third_party/libvpx"
 rtc_libyuv_dir = "//third_party/libyuv"
 rtc_opus_dir = "//third_party/opus"
+
+###############################################################################
+# Templates
+#
+
+# Points to //webrtc/ in webrtc stand-alone or to //third_party/webrtc/ in
+# chromium.
+# We need absolute paths for all configs in templates as they are shared in
+# different subdirectories.
+webrtc_root = get_path_info("../", "abspath")
+
+# Common configs to remove or add in all rtc targets.
+rtc_remove_configs = []
+rtc_add_configs = []
+
+set_defaults("rtc_test") {
+  configs = []
+  configs_suppressions = []

[kjellander_webrtc, 2016/09/01 19:55:29]

I'm not fully happy with this name, as we're using "suppressions" for all the
memory tools etc to silence errors. What about just calling it 'remove_configs'
instead? Once we've started hunting down all the cases of
//build/config/clang:find_bad_constructs it's going to be rarely used anyway.

If you disagree I can probably be convinced to stick with 'configs_suppressions'
though...

+}
+
+set_defaults("rtc_source_set") {
+  configs = []
+  configs_suppressions = []
+}
+
+set_defaults("rtc_executable") {
+  configs = []
+  configs_suppressions = []
+}
+
+set_defaults("rtc_static_library") {
+  configs = []
+  configs_suppressions = []
+}
+
+template("rtc_test") {
+  test(target_name) {
+    forward_variables_from(invoker,
+                           "*",
+                           [
+                             "configs",
+                             "configs_suppressions",
+                           ])
+    configs += invoker.configs
+    configs += rtc_add_configs
+    configs -= rtc_remove_configs
+    configs -= invoker.configs_suppressions
+  }
+}
+
+template("rtc_source_set") {
+  source_set(target_name) {
+    forward_variables_from(invoker,
+                           "*",
+                           [
+                             "configs",
+                             "configs_suppressions",
+                           ])
+    configs += invoker.configs
+    configs += rtc_add_configs
+    configs -= rtc_remove_configs
+    configs -= invoker.configs_suppressions
+  }
+}
+
+template("rtc_executable") {
+  executable(target_name) {
+    forward_variables_from(invoker,
+                           "*",
+                           [
+                             "configs",
+                             "configs_suppressions",
+                           ])
+    configs += invoker.configs
+    configs += rtc_add_configs
+    configs -= rtc_remove_configs
+    configs -= invoker.configs_suppressions
+  }
+}
+
+template("rtc_static_library") {
+  static_library(target_name) {
+    forward_variables_from(invoker,
+                           "*",
+                           [
+                             "configs",
+                             "configs_suppressions",
+                           ])
+    configs += invoker.configs
+    configs += rtc_add_configs
+    configs -= rtc_remove_configs
+    configs -= invoker.configs_suppressions
+  }
+}