Modify build scripts for ios .framework to compile metal shaders.

webrtc/sdk/objc/compile_metal_lib.py

Index: webrtc/sdk/objc/compile_metal_lib.py
diff --git a/webrtc/sdk/objc/compile_metal_lib.py b/webrtc/sdk/objc/compile_metal_lib.py
new file mode 100644
index 0000000000000000000000000000000000000000..c04b8a0f5e57135612c22e921262edf3008ee50a
--- /dev/null
+++ b/webrtc/sdk/objc/compile_metal_lib.py
@@ -0,0 +1,45 @@
+# Copyright 2016 The WebRTC project authors. All Rights Reserved.

[kjellander_webrtc, 2017/02/02 12:20:43]

2017

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+#
+# 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 argparse

[kjellander_webrtc, 2017/02/02 12:20:43]

Please add a short module docstring explaining what this script does.
It's worth mentioning it's designed to be run as an GN action.

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+import subprocess
+import sys
+

[kjellander_webrtc, 2017/02/02 12:20:43]

+1 blank line for top-level statements (it's a silly style rule, I know).
https://google.github.io/styleguide/pyguide.html?showone=Blank_Lines#Blank_Lines

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+if __name__ == '__main__':

[kjellander_webrtc, 2017/02/02 12:20:43]

Please use a main() function:
https://google.github.io/styleguide/pyguide.html?showone=Main#Main

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+  parser = argparse.ArgumentParser(
+      description='A script to compile metal shaders.')
+  parser.add_argument('-i', '--input', required=True,
+                      help='Path to input metal shaders.')
+  parser.add_argument('-o', '--output', required=True,
+                      help='Path to output bundle.')
+  args, unknown_args = parser.parse_known_args()
+
+ # TODO(denicija): replace the hardcoded iphoneos with the proper sdk var when we add metal for mac

[kjellander_webrtc, 2017/02/02 12:20:43]

Wrap at column 80.

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+  metal_air_args = [
+    'xcrun',
+    '-sdk',
+    'iphoneos',
+    'metal',
+    args.input,
+    '-o',
+    args.output+'/rtc_shaders.air'
+  ]
+  toolout = subprocess.Popen(metal_air_args)
+  if toolout.wait() == 0:
+    metal_lib_args = [
+      'xcrun',
+      '-sdk',
+      'iphoneos',
+      'metallib',
+      args.output+'/rtc_shaders.air',
+      '-o',
+      args.output+'/rtc_shaders.metallib'
+    ]
+    toolout = subprocess.Popen(metal_lib_args)

[kthelgason, 2017/02/02 12:30:21]

We need to wait for this subproccess to finish as well before looking at
`returncode`. 

[daniela-webrtc, 2017/02/02 15:11:44]

Done.

+
+  sys.exit(toolout.returncode)