Don't link with audio codecs that we don't use

webrtc/modules/audio_coding/BUILD.gn

 # 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/webrtc.gni")
@@ skipping 49 matching lines @@
 
   if (is_clang) {
     # Suppress warnings from Chrome's Clang plugins.
     # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
     configs -= [ "//build/config/clang:find_bad_constructs" ]
   }
 
   deps = [
     ":cng",
     ":g711",
-    ":g722",
-    ":ilbc",
-    ":isac",
-    ":isac_fix",
     ":neteq",
     ":pcm16b",
-    ":red",
     "../..:rtc_event_log",
     "../..:webrtc_common",
     "../../common_audio",
     "../../system_wrappers",
   ]
 
   if (rtc_include_opus) {
     defines += [ "WEBRTC_CODEC_OPUS" ]
     deps += [ ":webrtc_opus" ]
   }
+  if (!build_with_mozilla) {

[kjellander_webrtc, 2015/09/22 11:01:28]

Since line 82-92 is duplicated below, maybe you can move it to its own config
target and depend on it? I'm not entirely sure it'll end up with the same
behavior, but I think it might.

[kwiberg-webrtc, 2015/09/22 12:05:14]

Will do this in a later CL (see discussion below).

+    if (current_cpu == "arm") {

[kjellander_webrtc, 2015/09/22 11:01:28]

or current_cpu=="arm64" ?

[kwiberg-webrtc, 2015/09/22 12:05:14]

Well, that might make sense. But it won't preserve the current behavior; see the
removed code in engine_configurations.h. There, things are conditional on
WEBRTC_ARCH_ARM, which is set iff current_cpu=="arm" (gn) or target_cpu=="arm".)

So it doesn't seem like a good move to do that in this CL. And since it's
performance needs that made us choose iSAC for arm, it's not obvious (at least
to me) that arm64 should automatically be treated the same without investigating
the pros and cons first.

Other Henrik, what's your opinion?

[kjellander_webrtc, 2015/09/22 12:35:25]

I see. I thought WEBRTC_ARCH_ARM was defined for both. My mistake.

+      defines += [ "WEBRTC_CODEC_ISACFX" ]
+      deps += [ ":isac_fix" ]
+    } else {
+      defines += [ "WEBRTC_CODEC_ISAC" ]
+      deps += [ ":isac" ]
+    }
+    defines += [ "WEBRTC_CODEC_G722" ]
+    deps += [ ":g722" ]
+  }
+  if (!build_with_mozilla && !build_with_chromium) {
+    defines += [
+      "WEBRTC_CODEC_ILBC",
+      "WEBRTC_CODEC_RED",
+    ]
+    deps += [
+      ":ilbc",
+      ":red",
+    ]
+  }
 }
 
 source_set("audio_decoder_interface") {
   sources = [
     "codecs/audio_decoder.cc",
     "codecs/audio_decoder.h",
   ]
   configs += [ "../..:common_config" ]
   public_configs = [ "../..:common_inherited_config" ]
   deps = [
@@ skipping 684 matching lines @@
 
   public_configs = [
     "../..:common_inherited_config",
     ":neteq_config",
   ]
 
   deps = [
     ":audio_decoder_interface",
     ":cng",
     ":g711",
-    ":g722",
-    ":ilbc",
-    ":isac",
-    ":isac_fix",
     ":pcm16b",
     "../..:webrtc_common",
     "../../common_audio",
     "../../system_wrappers",
   ]
 
   defines = []
 
   if (rtc_include_opus) {
     defines += [ "WEBRTC_CODEC_OPUS" ]
     deps += [ ":webrtc_opus" ]
   }
+  if (!build_with_mozilla) {
+    if (current_cpu == "arm") {

[kjellander_webrtc, 2015/09/22 11:01:28]

arm64 as well.

[kwiberg-webrtc, 2015/09/22 12:05:14]

Not in this CL; see above.

[kjellander_webrtc, 2015/09/22 12:35:25]

Fair enough.

+      defines += [ "WEBRTC_CODEC_ISACFX" ]
+      deps += [ ":isac_fix" ]
+    } else {
+      defines += [ "WEBRTC_CODEC_ISAC" ]
+      deps += [ ":isac" ]
+    }
+    defines += [ "WEBRTC_CODEC_G722" ]
+    deps += [ ":g722" ]
+  }
+  if (!build_with_mozilla && !build_with_chromium) {
+    defines += [ "WEBRTC_CODEC_ILBC" ]
+    deps += [ ":ilbc" ]
+  }

[kwiberg-webrtc, 2015/09/22 08:37:15]

This duplication will go away soon; I'm just about to start working on
collecting all the built-in codecs in a single place.

[hlundin-webrtc, 2015/09/22 09:09:17]

Acknowledged.

 }