Add ndk_missing_symbols.py.

ndk_missing_symbols.py pulls libc.so and libm.so off a running device
or emulator and shows the list of symbols that are in the current
bionic that aren't available on the target.

Change-Id: Ia92c315a6a0ce2e5c33db0b62c8fab41c08a4c31

libc/tools/ndk_missing_symbols.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python2
+#
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import os
+import subprocess
+import tempfile
+
+import symbols
+
+
+def adb_pull(src, dst):
+    with open(os.devnull, 'w') as devnull:
+        subprocess.check_call(['adb', 'pull', src, dst],
+                              stdout=devnull, stderr=devnull)
+
+
+def main():
+    tmp_dir = tempfile.mkdtemp()
+    adb_pull('/system/lib/libc.so', tmp_dir)
+    adb_pull('/system/lib/libm.so', tmp_dir)
+
+    current = symbols.GetFromAndroidSo(['libc.so', 'libm.so'])
+    device = (symbols.GetFromSo(os.path.join(tmp_dir, 'libc.so')) |
+              symbols.GetFromSo(os.path.join(tmp_dir, 'libm.so')))
+
+    for symbol in sorted(current - device):
+        print symbol
+
+
+if __name__ == '__main__':
+    main()