Add symbol checking script to libc++ to help manage exported symbols.

Summary:
Add symbol checking scripts for extracting a list of symbols from shared libraries and for comparing symbol lists for differences.



Reviewers: mclow.lists, danalbert, EricWF

Reviewed By: EricWF

Subscribers: majnemer, emaste, cfe-commits

Differential Revision: http://reviews.llvm.org/D4946

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@232855 91177308-0d34-0410-b5e6-96231b3b80d8

utils/sym_check/sym_match.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+"""
+sym_match - Match all symbols in a list against a list of regexes.
+"""
+from argparse import ArgumentParser
+import sys
+from sym_check import util, match, extract
+
+
+def main():
+    parser = ArgumentParser(
+        description='Extract a list of symbols from a shared library.')
+    parser.add_argument(
+        '--blacklist', dest='blacklist',
+        type=str, action='store', default=None)
+    parser.add_argument(
+        'symbol_list', metavar='symbol_list', type=str,
+        help='The file containing the old symbol list')
+    parser.add_argument(
+        'regexes', metavar='regexes', default=[], nargs='*',
+        help='The file containing the new symbol list or a library')
+    args = parser.parse_args()
+
+    if not args.regexes and args.blacklist is None:
+        sys.stderr.write('Either a regex or a blacklist must be specified.\n')
+        sys.exit(1)
+    if args.blacklist:
+        search_list = util.read_blacklist(args.blacklist)
+    else:
+        search_list = args.regexes
+
+    symbol_list = util.extract_or_load(args.symbol_list)
+
+    matching_count, report = match.find_and_report_matching(
+        symbol_list, search_list)
+    sys.stdout.write(report)
+    if matching_count != 0:
+        print('%d matching symbols found...' % matching_count)
+
+
+if __name__ == '__main__':
+    main()