Bug 1062709 (part 2) - Clean up stack printing and fixing. r=dbaron.

tools/rb/fix_linux_stack.py

@@ -4,18 +4,9 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-# This script uses addr2line (part of binutils) to process the output of
-# nsTraceRefcnt's Linux stack walking code.  This is useful for two
-# things:
-#  (1) Getting line number information out of
-#      |nsTraceRefcnt::WalkTheStack|'s output in debug builds.
-#  (2) Getting function names out of |nsTraceRefcnt::WalkTheStack|'s
-#      output on optimized builds (where it mostly prints UNKNOWN
-#      because only a handful of symbols are exported from component
-#      libraries).
-#
-# Use the script by piping output containing stacks (such as raw stacks
-# or make-tree.pl balance trees) through this script.
+# This script uses addr2line (part of binutils) to post-process the entries
+# produced by NS_FormatCodeAddress(), which on Linux often lack a function
+# name, a file name and a line number.
 
 import subprocess
 import sys
@@ -296,25 +287,20 @@ def addressToSymbol(file, address):
     cache[address] = result
     return result
 
-line_re = re.compile("^(.*) ?\[([^ ]*) \+(0x[0-9A-F]{1,8})\](.*)$")
-balance_tree_re = re.compile("^([ \|0-9-]*)(.*)$")
+# Matches lines produced by NS_FormatCodeAddress().
+line_re = re.compile("^(.*#\d+: )(.+)\[(.+) \+(0x.+)\](.*)$")
 
 def fixSymbols(line):
     result = line_re.match(line)
     if result is not None:
-        # before allows preservation of balance trees
-        # after allows preservation of counts
-        (before, file, address, after) = result.groups()
+        (before, fn, file, address, after) = result.groups()
 
         if os.path.exists(file) and os.path.isfile(file):
-            # throw away the bad symbol, but keep balance tree structure
-            (before, badsymbol) = balance_tree_re.match(before).groups()
-
             (name, fileline) = addressToSymbol(file, address)
 
             # If addr2line gave us something useless, keep what we had before.
             if name == "??":
-                name = badsymbol
+                name = fn
             if fileline == "??:0" or fileline == "??:?":
                 fileline = file