A tool for mapping runtime addresses to symbol names.

tools/find_runtime_symbols/procedure_boundaries.py

+#!/usr/bin/env python

[M-A Ruel, 2012/07/19 15:21:15]

Remove the shebang on files not executable. 

[Dai Mikurube (NOT FULLTIME), 2012/07/20 04:32:39]

Done.

+
+import bisect
+import os
+import re
+import sys
+
+class ParsingException(Exception):
+  def __init__(self, value):

[M-A Ruel, 2012/07/19 15:21:15]

The __init__ is not strictly necessary. You can use self.args[0] in your __str__
function.

[Dai Mikurube (NOT FULLTIME), 2012/07/20 04:32:39]

Thanks.  Done it.

+    self.value = value
+  def __str__(self):
+    return repr(self.value)
+
+
+class ProcedureBoundary(object):
+  def __init__(self, start, end, name):
+    self.start = start
+    self.end = end
+    self.name = name
+
+
+class ProcedureBoundaryTable(object):
+  def __init__(self):
+    self.sorted_value_list = []
+    self.dictionary = {}
+    self.sorted = True
+
+  def append(self, entry):
+    if self.sorted_value_list:
+      if self.sorted_value_list[-1] > entry.start:
+        self.sorted = False
+      elif self.sorted_value_list[-1] == entry.start:
+        return
+    self.sorted_value_list.append(entry.start)
+    self.dictionary[entry.start] = entry
+
+  def find_procedure(self, address):
+    if not self.sorted:
+      self.sorted_value_list.sort()
+      self.sorted = True
+    found_index = bisect.bisect_left(self.sorted_value_list, address)
+    found_start_address = self.sorted_value_list[found_index - 1]
+    return self.dictionary[found_start_address]
+
+
+_ARGUMENT_TYPE_PATTERN = re.compile('\([^()]*\)(\s*const)?')
+_TEMPLATE_ARGUMENT_PATTERN = re.compile('<[^<>]*>')
+_LEADING_TYPE_PATTERN = re.compile('^.*\s+(\w+::)')
+
+def _get_short_function_name(function):
+  while True:
+    function, number = _ARGUMENT_TYPE_PATTERN.subn('', function)

[M-A Ruel, 2012/07/19 15:21:15]

A constant is not strictly necessary when used only at one place. Remember that
all functions inside module re keep a cache of recently used regexp so when it
is used inside a loop, it's fast enough. 

[Dai Mikurube (NOT FULLTIME), 2012/07/20 04:32:39]

As far as I remember, only one regexp is kept in module re. 
_get_short_function_name() is called very many times, and it loops only once or
twice in most cases.

+    if number == 0:

[M-A Ruel, 2012/07/19 15:21:15]

if not number:
unless you want to differentiate with None.

[Dai Mikurube (NOT FULLTIME), 2012/07/20 04:32:39]

Done.

+      break
+  while True:
+    function, number = _TEMPLATE_ARGUMENT_PATTERN.subn('', function)
+    if number == 0:
+      break
+  function = _LEADING_TYPE_PATTERN.sub('\g<1>', function)
+  return function
+
+
+def get_procedure_boundaries_from_nm_bsd(FILE, mangled=False):
+  """Gets procedure boundaries from a result of nm -n --format bsd.
+
+  Args:
+      FILE: A file object containing a result of nm.  It must be sorted and
+          in BSD-style.  (Use "[eu-]nm -n --format bsd")
+
+  Returns:
+      A result ProcedureBoundaryTable object.
+  """
+  symbol_table = ProcedureBoundaryTable()
+
+  last_start = 0;
+  routine = '';

[M-A Ruel, 2012/07/19 15:21:15]

; ?

[Dai Mikurube (NOT FULLTIME), 2012/07/20 04:32:39]

Wow, removed them.  (I was translating this code from Perl...)

+
+  for line in FILE:
+    symbol_info = line.rstrip().split(None, 2)
+    if len(symbol_info) == 3:
+      if len(symbol_info[0]) == 1:
+        symbol_info = line.split(None, 1)
+        (sym_type, this_routine) = symbol_info
+        sym_value = ''
+      else:
+        (sym_value, sym_type, this_routine) = symbol_info
+    elif len(symbol_info) == 2:
+      if len(symbol_info[0]) == 1:
+        (sym_type, this_routine) = symbol_info
+        sym_value = ''
+      elif len(symbol_info[0]) == 8 or len(symbol_info[0]) == 16:
+        (sym_value, this_routine) = symbol_info
+        sym_type = ' '
+      else:
+        raise ParsingException('Invalid output 1 from (eu-)nm.')
+    else:
+      raise ParsingException('Invalid output 2 from (eu-)nm.')
+
+    if sym_value == '':
+      continue
+
+    start_val = int(sym_value, 16)
+
+    # It's possible for two symbols to share the same address, if
+    # one is a zero-length variable (like __start_google_malloc) or
+    # one symbol is a weak alias to another (like __libc_malloc).
+    # In such cases, we want to ignore all values except for the
+    # actual symbol, which in nm-speak has type "T".  The logic
+    # below does this, though it's a bit tricky: what happens when
+    # we have a series of lines with the same address, is the first
+    # one gets queued up to be processed.  However, it won't
+    # *actually* be processed until later, when we read a line with
+    # a different address.  That means that as long as we're reading
+    # lines with the same address, we have a chance to replace that
+    # item in the queue, which we do whenever we see a 'T' entry --
+    # that is, a line with type 'T'.  If we never see a 'T' entry,
+    # we'll just go ahead and process the first entry (which never
+    # got touched in the queue), and ignore the others.
+    if start_val == last_start and (sym_type == 't' or sym_type == 'T'):
+      # We are the 'T' symbol at this address, replace previous symbol.
+      routine = this_routine
+      continue
+    elif start_val == last_start:
+      # We're not the 'T' symbol at this address, so ignore us.
+      continue
+
+    # Tag this routine with the starting address in case the image
+    # has multiple occurrences of this routine.  We use a syntax
+    # that resembles template paramters that are automatically
+    # stripped out by ShortFunctionName()
+    this_routine += "<%016x>" % start_val;
+
+    if not mangled:
+      routine = _get_short_function_name(routine)
+    symbol_table.append(ProcedureBoundary(last_start, start_val, routine))
+
+    last_start = start_val
+    routine = this_routine
+
+  if not mangled:
+    routine = _get_short_function_name(routine)
+  symbol_table.append(ProcedureBoundary(last_start, last_start, routine))
+  return symbol_table