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/symbols.py

@@ -0,0 +1,74 @@
+#
+# 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 glob
+import os
+import re
+import subprocess
+
+
+def GetFromTxt(txt_file):
+    symbols = set()
+    f = open(txt_file, 'r')
+    for line in f.read().splitlines():
+        symbols.add(line)
+    f.close()
+    return symbols
+
+
+def GetFromSo(so_file):
+    # pylint: disable=line-too-long
+    # Example readelf output:
+    #     264: 0001623c         4 FUNC        GLOBAL DEFAULT        8 cabsf
+    #     266: 00016244         4 FUNC        GLOBAL DEFAULT        8 dremf
+    #     267: 00019018         4 OBJECT    GLOBAL DEFAULT     11 __fe_dfl_env
+    #     268: 00000000         0 FUNC        GLOBAL DEFAULT    UND __aeabi_dcmplt
+
+    r = re.compile(
+        r' +\d+: [0-9a-f]+ +\d+ (I?FUNC|OBJECT) +\S+ +\S+ +\d+ (\S+)')
+
+    symbols = set()
+
+    output = subprocess.check_output(['readelf', '--dyn-syms', '-W', so_file])
+    for line in output.split('\n'):
+        if ' HIDDEN ' in line or ' UND ' in line:
+            continue
+        m = r.match(line)
+        if m:
+            symbol = m.group(2)
+            symbol = re.sub('@.*', '', symbol)
+            symbols.add(symbol)
+
+    return symbols
+
+
+def GetFromAndroidSo(files):
+    out_dir = os.environ['ANDROID_PRODUCT_OUT']
+    lib_dir = os.path.join(out_dir, 'system/lib64')
+    if not os.path.isdir(lib_dir):
+        lib_dir = os.path.join(out_dir, 'system/lib')
+
+    results = set()
+    for f in files:
+        results |= GetFromSo(os.path.join(lib_dir, f))
+    return results
+
+
+def GetFromSystemSo(files):
+    lib_dir = '/lib/x86_64-linux-gnu'
+    results = set()
+    for f in files:
+        results |= GetFromSo(glob.glob(os.path.join(lib_dir, f))[-1])
+    return results