Print suppression hashes for TSan reports

tools/valgrind/tsan_analyze.py

 #!/usr/bin/python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # tsan_analyze.py
 
 ''' Given a ThreadSanitizer output file, parses errors and uniques them.'''
 
 import gdb_helper
 
 import common
+import hashlib
 import logging
 import optparse
 import os
 import re
 import subprocess
 import sys
 import time
 
 # Global symbol table (ugh)
 TheAddressTable = None
@@ skipping 82 matching lines @@
     result = [self.line_]
     if re.search("{{{", self.line_):
       while not re.search('}}}', self.line_):
         self.ReadLine()
         if self.stack_trace_line_ is None:
           result.append(self.line_)
         else:
           result.append(self.stack_trace_line_)
       self.ReadLine()
       if re.match('-+ suppression -+', self.line_):
-        result.append(self.line_)
+        # We need to calculate the suppression hash and prepend a line like
+        # "Suppression (error hash=#0123456789ABCDEF#):" so the buildbot can
+        # extract the suppression snippet.
+        supp = ""
         while not re.match('-+ end suppression -+', self.line_):
           self.ReadLine()
-          result.append(self.line_)
+          supp += self.line_
         self.ReadLine()
+        result.append("Suppression (error hash=#%016X#):\n" % \
+                      (int(hashlib.md5(supp).hexdigest()[:16], 16)))
+        result.append("  For more info on using suppressions see "
+            "http://dev.chromium.org/developers/how-tos/using-valgrind/threadsanitizer#TOC-Suppressing-data-races\n")
+        result.append(supp)
     else:
       self.ReadLine()
 
     return result
 
   def ReadTillTheEnd(self):
     result = [self.line_]
     while self.line_:
       self.ReadLine()
       result.append(self.line_)
@@ skipping 122 matching lines @@
 
   (options, args) = parser.parse_args()
   if not args:
     parser.error("no filename specified")
   filenames = args
 
   analyzer = TsanAnalyzer(options.source_dir, use_gdb=True)
   retcode = analyzer.Report(filenames)
 
   sys.exit(retcode)