Refactor the symbolize step of the orderfile generation.

tools/cygprofile/cyglog_to_orderfile.py

Index: tools/cygprofile/cyglog_to_orderfile.py
diff --git a/tools/cygprofile/cyglog_to_orderfile.py b/tools/cygprofile/cyglog_to_orderfile.py
new file mode 100755
index 0000000000000000000000000000000000000000..0213fa49a641a416469a5ba6a1631663932474c5
--- /dev/null
+++ b/tools/cygprofile/cyglog_to_orderfile.py
@@ -0,0 +1,262 @@
+#!/usr/bin/python
+# Copyright 2015 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.
+
+"""Symbolizes a log file produced by cyprofile instrumentation.
+
+Given a log file and the binary being profiled, creates an orderfile.
+"""
+
+import logging
+import multiprocessing
+import optparse
+import os
+import tempfile
+import string
+import sys
+
+import symbol_extractor
+
+
+def _ParseLogLines(log_file_lines):
+  """Parses a merged cyglog produced by mergetraces.py.
+
+  Args:
+    log_file_lines: array of lines in log file produced by profiled run
+    lib_name: library or executable containing symbols
+
+    Below is an example of a small log file:
+    5086e000-52e92000 r-xp 00000000 b3:02 51276      libchromeview.so
+    secs       usecs      pid:threadid    func
+    START
+    1314897086 795828     3587:1074648168 0x509e105c
+    1314897086 795874     3587:1074648168 0x509e0eb4
+    1314897086 796326     3587:1074648168 0x509e0e3c
+    1314897086 796552     3587:1074648168 0x509e07bc
+    END
+
+  Returns:
+    An ordered list of callee offsets.
+  """
+  call_lines = []
+  vm_start = 0
+  line = log_file_lines[0]
+  assert 'r-xp' in line
+  end_index = line.find('-')
+  vm_start = int(line[:end_index], 16)
+  for line in log_file_lines[3:]:
+    fields = line.split()
+    if len(fields) == 4:
+      call_lines.append(fields)
+    else:
+      assert fields[0] == 'END'
+  # Convert strings to int in fields.
+  call_info = []
+  for call_line in call_lines:
+    addr = int(call_line[3], 16)
+    if vm_start < addr:
+      addr -= vm_start
+      call_info.append(addr)
+  return call_info
+
+
+def _GroupLibrarySymbolInfosByOffset(lib_filename):
+  """Returns a dict {offset: [SymbolInfo]} from a library."""
+  symbol_infos = symbol_extractor.SymbolInfosFromBinary(lib_filename)
+  return symbol_extractor.GroupSymbolInfosByOffset(symbol_infos)
+
+
+class SymbolNotFoundException(Exception):
+  def __init__(self, value):
+    super(SymbolNotFoundException, self).__init__(value)
+    self.value = value
+
+  def __str__(self):
+    return repr(self.value)
+
+
+def _FindSymbolInfosAtOffset(offset_to_symbol_infos, offset):
+  """Finds all SymbolInfo at a given offset.
+
+  Args:
+    offset_to_symbol_infos: {offset: [SymbolInfo]}
+    offset: offset to look the symbols at
+
+  Returns:
+    The list of SymbolInfo at the given offset
+
+  Raises:
+    SymbolNotFoundException if the offset doesn't match any symbol.
+  """
+  if offset in offset_to_symbol_infos:
+    return offset_to_symbol_infos[offset]
+  elif offset % 2 and (offset - 1) in offset_to_symbol_infos:
+    # On ARM, odd addresses are used to signal thumb instruction. They are
+    # generated by setting the LSB to 1 (see
+    # http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471e/Babfjhia.html).
+    # TODO(lizeb): Make sure this hack doesn't propagate to other archs.
+    return offset_to_symbol_infos[offset - 1]
+  else:
+    raise SymbolNotFoundException(offset)
+
+
+class WarningCollector(object):
+  """Collect warnings, but limit the number printed to a set value."""
+  def __init__(self, max_warnings):
+    self._warnings = 0
+    self._max_warnings = max_warnings
+
+  def Write(self, message):
+    if self._warnings < self._max_warnings:
+      logging.warning(message)
+    self._warnings += 1
+
+  def WriteEnd(self, message):
+    if self._warnings > self._max_warnings:
+      logging.warning('%d more warnings for: %s' % (
+          self._warnings - self._max_warnings, message))
+
+
+def _GetObjectFileNames(obj_dir):
+  """Returns the list of object files in a directory."""
+  obj_files = []
+  for (dirpath, _, filenames) in os.walk(obj_dir):
+    for file_name in filenames:
+      if file_name.endswith('.o'):
+        obj_files.append(os.path.join(dirpath, file_name))
+  return obj_files
+
+
+def _AllSymbolInfos(object_filenames):
+  """Returns a list of SymbolInfo from an iterable of filenames."""
+  pool = multiprocessing.Pool()
+  # Hopefully the object files are in the page cache at this step, so IO should
+  # not be a problem (hence no concurrency limit on the pool).
+  symbol_infos_nested = pool.map(
+      symbol_extractor.SymbolInfosFromBinary, object_filenames)
+  result = []
+  for symbol_infos in symbol_infos_nested:
+    result += symbol_infos
+  return result
+
+
+def _GetSymbolToSectionMapFromObjectFiles(obj_dir):
+  """ Creates a mapping from symbol to linker section name by scanning all
+      the object files.
+  """
+  object_files = _GetObjectFileNames(obj_dir)
+  symbol_to_section_map = {}
+  symbol_warnings = WarningCollector(300)
+  symbol_infos = _AllSymbolInfos(object_files)
+  for symbol_info in symbol_infos:
+    symbol = symbol_info.name
+    if symbol.startswith('.LTHUNK'):
+      continue
+    section = symbol_info.section
+    if ((symbol in symbol_to_section_map) and
+        (symbol_to_section_map[symbol] != symbol_info.section)):
+      symbol_warnings.Write('Symbol ' + symbol +
+                            ' in conflicting sections ' + section +
+                            ' and ' + symbol_to_section_map[symbol])
+    elif not section.startswith('.text'):
+      symbol_warnings.Write('Symbol ' + symbol +
+                            ' in incorrect section ' + section)
+    else:
+      symbol_to_section_map[symbol] = section
+  symbol_warnings.WriteEnd('bad sections')
+  return symbol_to_section_map
+
+
+def _WarnAboutDuplicates(offsets):
+  """Warns about duplicate offsets.
+
+  Args:
+    offsets: list of offsets to check for duplicates
+
+  Returns:
+    True if there are no duplicates, False otherwise.
+  """
+  seen_offsets = set()
+  ok = True
+  for offset in offsets:
+    if offset not in seen_offsets:
+      seen_offsets.add(offset)
+    else:
+      ok = False
+      logging.warning('Duplicate offset: ' + hex(offset))
+  return ok
+
+
+def _OutputOrderfile(offsets, offset_to_symbol_infos, symbol_to_section_map,
+                     output_file):
+  """Outputs the orderfile to output_file.
+
+  Args:
+    offsets: Iterable of offsets to match to section names
+    offset_to_symbol_infos: {offset: [SymbolInfo]}
+    symbol_to_section_map: {name: section}
+    output_file: file-like object to write the results to
+  """
+  success = True
+  unknown_symbol_warnings = WarningCollector(300)
+  symbol_not_found_warnings = WarningCollector(300)
+  for offset in offsets:
+    try:
+      symbol_infos = _FindSymbolInfosAtOffset(offset_to_symbol_infos, offset)
+      for symbol_info in symbol_infos:
+        if symbol_info.name in symbol_to_section_map:
+          output_file.write(symbol_to_section_map[symbol_info.name] + '\n')
+        else:
+          unknown_symbol_warnings.Write(
+              'No known section for symbol ' + symbol_info.name)
+    except SymbolNotFoundException:
+      symbol_not_found_warnings.Write(
+          'Did not find function in binary. offset: ' + hex(offset))
+      success = False
+  unknown_symbol_warnings.WriteEnd('no known section for symbol.')
+  symbol_not_found_warnings.WriteEnd('symbol not found in the binary.')
+  return success
+
+
+def main():
+  if len(sys.argv) != 4:
+    logging.error('Usage: cyglog_to_orderfile.py <merged_cyglog> '
+                  '<library> <output_filename>')
+    return 1
+  (log_filename, lib_filename, output_filename) = sys.argv[1:]
+
+  obj_dir = os.path.abspath(os.path.join(
+      os.path.dirname(lib_filename), '../obj'))
+
+  log_file_lines = map(string.rstrip, open(log_filename).readlines())
+  offsets = _ParseLogLines(log_file_lines)
+  _WarnAboutDuplicates(offsets)
+
+  offset_to_symbol_infos = _GroupLibrarySymbolInfosByOffset(lib_filename)
+  symbol_to_section_map = _GetSymbolToSectionMapFromObjectFiles(obj_dir)
+
+  success = False
+  temp_filename = None
+  output_file = None
+  try:
+    (fd, temp_filename) = tempfile.mkstemp(dir=os.path.dirname(output_filename))
+    output_file = os.fdopen(fd, 'w')
+    ok = _OutputOrderfile(
+        offsets, offset_to_symbol_infos, symbol_to_section_map, output_file)
+    output_file.close()
+    os.rename(temp_filename, output_filename)
+    temp_filename = None
+    success = ok
+  finally:
+    if output_file:
+      output_file.close()
+    if temp_filename:
+      os.remove(temp_filename)
+
+  return 0 if success else 1
+
+
+if __name__ == '__main__':
+  logging.basicConfig(level=logging.INFO)
+  sys.exit(main())