lldb/examples/python/crashlog.py

#!/usr/bin/python

#----------------------------------------------------------------------
# Be sure to add the python path that points to the LLDB shared library.
#
# To use this in the embedded python interpreter using "lldb":
#
#   cd /path/containing/crashlog.py
#   lldb
#   (lldb) script import crashlog
#   "crashlog" command installed, type "crashlog --help" for detailed help
#   (lldb) crashlog ~/Library/Logs/DiagnosticReports/a.crash
#
# The benefit of running the crashlog command inside lldb in the 
# embedded python interpreter is when the command completes, there 
# will be a target with all of the files loaded at the locations
# described in the crash log. Only the files that have stack frames
# in the backtrace will be loaded unless the "--load-all" option
# has been specified. This allows users to explore the program in the
# state it was in right at crash time. 
#
# On MacOSX csh, tcsh:
#   ( setenv PYTHONPATH /path/to/LLDB.framework/Resources/Python ; ./crashlog.py ~/Library/Logs/DiagnosticReports/a.crash )
#
# On MacOSX sh, bash:
#   PYTHONPATH=/path/to/LLDB.framework/Resources/Python ./crashlog.py ~/Library/Logs/DiagnosticReports/a.crash
#----------------------------------------------------------------------

import commands
import cmd
import datetime
import glob
import optparse
import os
import platform
import plistlib
import pprint # pp = pprint.PrettyPrinter(indent=4); pp.pprint(command_args)
import re
import shlex
import string
import sys
import time
import uuid

try: 
    # Just try for LLDB in case PYTHONPATH is already correctly setup
    import lldb
except ImportError:
    lldb_python_dirs = list()
    # lldb is not in the PYTHONPATH, try some defaults for the current platform
    platform_system = platform.system()
    if platform_system == 'Darwin':
        # On Darwin, try the currently selected Xcode directory
        xcode_dir = commands.getoutput("xcode-select --print-path")
        if xcode_dir:
            lldb_python_dirs.append(os.path.realpath(xcode_dir + '/../SharedFrameworks/LLDB.framework/Resources/Python'))
            lldb_python_dirs.append(xcode_dir + '/Library/PrivateFrameworks/LLDB.framework/Resources/Python')
        lldb_python_dirs.append('/System/Library/PrivateFrameworks/LLDB.framework/Resources/Python')
    success = False
    for lldb_python_dir in lldb_python_dirs:
        if os.path.exists(lldb_python_dir):
            if not (sys.path.__contains__(lldb_python_dir)):
                sys.path.append(lldb_python_dir)
                try: 
                    import lldb
                except ImportError:
                    pass
                else:
                    print 'imported lldb from: "%s"' % (lldb_python_dir)
                    success = True
                    break
    if not success:
        print "error: couldn't locate the 'lldb' module, please set PYTHONPATH correctly"
        sys.exit(1)

from lldb.utils import symbolication

PARSE_MODE_NORMAL = 0
PARSE_MODE_THREAD = 1
PARSE_MODE_IMAGES = 2
PARSE_MODE_THREGS = 3
PARSE_MODE_SYSTEM = 4

class CrashLog(symbolication.Symbolicator):
    """Class that does parses darwin crash logs"""
    parent_process_regex = re.compile('^Parent Process:\s*(.*)\[(\d+)\]');
    thread_state_regex = re.compile('^Thread ([0-9]+) crashed with')
    thread_regex = re.compile('^Thread ([0-9]+)([^:]*):(.*)')
    frame_regex = re.compile('^([0-9]+) +([^ ]+) *\t?(0x[0-9a-fA-F]+) +(.*)')
    image_regex_uuid = re.compile('(0x[0-9a-fA-F]+)[- ]+(0x[0-9a-fA-F]+) +[+]?([^ ]+) +([^<]+)<([-0-9a-fA-F]+)> (.*)');
    image_regex_no_uuid = re.compile('(0x[0-9a-fA-F]+)[- ]+(0x[0-9a-fA-F]+) +[+]?([^ ]+) +([^/]+)/(.*)');
    empty_line_regex = re.compile('^$')
        
    class Thread:
        """Class that represents a thread in a darwin crash log"""
        def __init__(self, index):
            self.index = index
            self.frames = list()
            self.idents = list()
            self.registers = dict()
            self.reason = None
            self.queue = None
        
        def dump(self, prefix):
            print "%sThread[%u] %s" % (prefix, self.index, self.reason)
            if self.frames:
                print "%s  Frames:" % (prefix)
                for frame in self.frames:
                    frame.dump(prefix + '    ')
            if self.registers:
                print "%s  Registers:" % (prefix)
                for reg in self.registers.keys():
                    print "%s    %-5s = %#16.16x" % (prefix, reg, self.registers[reg])
        
        def add_ident(self, ident):
            if not ident in self.idents:
                self.idents.append(ident)
            
        def did_crash(self):
            return self.reason != None
        
        def __str__(self):
            s = "Thread[%u]" % self.index
            if self.reason:
                s += ' %s' % self.reason
            return s
        
    
    class Frame:
        """Class that represents a stack frame in a thread in a darwin crash log"""
        def __init__(self, index, pc, description):
            self.pc = pc
            self.description = description
            self.index = index
        
        def __str__(self):
            if self.description:
                return "[%3u] 0x%16.16x %s" % (self.index, self.pc, self.description)
            else:
                return "[%3u] 0x%16.16x" % (self.index, self.pc)

        def dump(self, prefix):
            print "%s%s" % (prefix, str(self))
    
    class DarwinImage(symbolication.Image):
        """Class that represents a binary images in a darwin crash log"""
        dsymForUUIDBinary = os.path.expanduser('~rc/bin/dsymForUUID')
        if not os.path.exists(dsymForUUIDBinary):
            dsymForUUIDBinary = commands.getoutput('which dsymForUUID')
            
        dwarfdump_uuid_regex = re.compile('UUID: ([-0-9a-fA-F]+) \(([^\(]+)\) .*')
        
        def __init__(self, text_addr_lo, text_addr_hi, identifier, version, uuid, path):
            symbolication.Image.__init__(self, path, uuid);
            self.add_section (symbolication.Section(text_addr_lo, text_addr_hi, "__TEXT"))
            self.identifier = identifier
            self.version = version
        
        def locate_module_and_debug_symbols(self):
            # Don't load a module twice...
            if self.resolved:
                return True
            # Mark this as resolved so we don't keep trying
            self.resolved = True
            uuid_str = self.get_normalized_uuid_string()
            print 'Getting symbols for %s %s...' % (uuid_str, self.path),
            if os.path.exists(self.dsymForUUIDBinary):
                dsym_for_uuid_command = '%s %s' % (self.dsymForUUIDBinary, uuid_str)
                s = commands.getoutput(dsym_for_uuid_command)
                if s:
                    plist_root = plistlib.readPlistFromString (s)
                    if plist_root:
                        plist = plist_root[uuid_str]
                        if plist:
                            if 'DBGArchitecture' in plist:
                                self.arch = plist['DBGArchitecture']
                            if 'DBGDSYMPath' in plist:
                                self.symfile = os.path.realpath(plist['DBGDSYMPath'])
                            if 'DBGSymbolRichExecutable' in plist:
                                self.path = os.path.expanduser (plist['DBGSymbolRichExecutable'])
                                self.resolved_path = self.path
            if not self.resolved_path and os.path.exists(self.path):
                dwarfdump_cmd_output = commands.getoutput('dwarfdump --uuid "%s"' % self.path)
                self_uuid = self.get_uuid()
                for line in dwarfdump_cmd_output.splitlines():
                    match = self.dwarfdump_uuid_regex.search (line)
                    if match:
                        dwarf_uuid_str = match.group(1)
                        dwarf_uuid = uuid.UUID(dwarf_uuid_str)
                        if self_uuid == dwarf_uuid:
                            self.resolved_path = self.path
                            self.arch = match.group(2)
                            break;
                if not self.resolved_path:
                    self.unavailable = True
                    print "error\n    error: unable to locate '%s' with UUID %s" % (self.path, uuid_str)
                    return False
            if (self.resolved_path and os.path.exists(self.resolved_path)) or (self.path and os.path.exists(self.path)):
                print 'ok'
                # if self.resolved_path:
                #     print '  exe = "%s"' % self.resolved_path 
                # if self.symfile:
                #     print ' dsym = "%s"' % self.symfile
                return True
            else:
                self.unavailable = True
            return False
        
    
        
    def __init__(self, path):
        """CrashLog constructor that take a path to a darwin crash log file"""
        symbolication.Symbolicator.__init__(self);
        self.path = os.path.expanduser(path);
        self.info_lines = list()
        self.system_profile = list()
        self.threads = list()
        self.idents = list() # A list of the required identifiers for doing all stack backtraces
        self.crashed_thread_idx = -1
        self.version = -1
        self.error = None
        # With possible initial component of ~ or ~user replaced by that user's home directory.
        try:
            f = open(self.path)
        except IOError:
            self.error = 'error: cannot open "%s"' % self.path
            return

        self.file_lines = f.read().splitlines()
        parse_mode = PARSE_MODE_NORMAL
        thread = None
        for line in self.file_lines:
            # print line
            line_len = len(line)
            if line_len == 0:
                if thread:
                    if parse_mode == PARSE_MODE_THREAD:
                        if thread.index == self.crashed_thread_idx:
                            thread.reason = ''
                            if self.thread_exception:
                                thread.reason += self.thread_exception
                            if self.thread_exception_data:
                                thread.reason += " (%s)" % self.thread_exception_data                                
                        self.threads.append(thread)
                    thread = None
                else:
                    # only append an extra empty line if the previous line 
                    # in the info_lines wasn't empty
                    if len(self.info_lines) > 0 and len(self.info_lines[-1]):
                        self.info_lines.append(line)
                parse_mode = PARSE_MODE_NORMAL
                # print 'PARSE_MODE_NORMAL'
            elif parse_mode == PARSE_MODE_NORMAL:
                if line.startswith ('Process:'):
                    (self.process_name, pid_with_brackets) = line[8:].strip().split(' [')
                    self.process_id = pid_with_brackets.strip('[]')
                elif line.startswith ('Path:'):
                    self.process_path = line[5:].strip()
                elif line.startswith ('Identifier:'):
                    self.process_identifier = line[11:].strip()
                elif line.startswith ('Version:'):
                    version_string = line[8:].strip()
                    matched_pair = re.search("(.+)\((.+)\)", version_string)
                    if matched_pair:
                        self.process_version = matched_pair.group(1)
                        self.process_compatability_version = matched_pair.group(2)
                    else:
                        self.process = version_string
                        self.process_compatability_version = version_string
                elif self.parent_process_regex.search(line):
                    parent_process_match = self.parent_process_regex.search(line)
                    self.parent_process_name = parent_process_match.group(1)
                    self.parent_process_id = parent_process_match.group(2)
                elif line.startswith ('Exception Type:'):
                    self.thread_exception = line[15:].strip()
                    continue
                elif line.startswith ('Exception Codes:'):
                    self.thread_exception_data = line[16:].strip()
                    continue
                elif line.startswith ('Crashed Thread:'):
                    self.crashed_thread_idx = int(line[15:].strip().split()[0])
                    continue
                elif line.startswith ('Report Version:'):
                    self.version = int(line[15:].strip())
                    continue
                elif line.startswith ('System Profile:'):
                    parse_mode = PARSE_MODE_SYSTEM
                    continue
                elif (line.startswith ('Interval Since Last Report:') or
                      line.startswith ('Crashes Since Last Report:') or
                      line.startswith ('Per-App Interval Since Last Report:') or
                      line.startswith ('Per-App Crashes Since Last Report:') or
                      line.startswith ('Sleep/Wake UUID:') or
                      line.startswith ('Anonymous UUID:')):
                    # ignore these
                    continue  
                elif line.startswith ('Thread'):
                    thread_state_match = self.thread_state_regex.search (line)
                    if thread_state_match:
                        thread_state_match = self.thread_regex.search (line)
                        thread_idx = int(thread_state_match.group(1))
                        parse_mode = PARSE_MODE_THREGS
                        thread = self.threads[thread_idx]
                    else:
                        thread_match = self.thread_regex.search (line)
                        if thread_match:
                            # print 'PARSE_MODE_THREAD'
                            parse_mode = PARSE_MODE_THREAD
                            thread_idx = int(thread_match.group(1))
                            thread = CrashLog.Thread(thread_idx)
                    continue
                elif line.startswith ('Binary Images:'):
                    parse_mode = PARSE_MODE_IMAGES
                    continue
                self.info_lines.append(line.strip())
            elif parse_mode == PARSE_MODE_THREAD:
                if line.startswith ('Thread'):
                    continue
                frame_match = self.frame_regex.search(line)
                if frame_match:
                    ident = frame_match.group(2)
                    thread.add_ident(ident)
                    if not ident in self.idents:
                        self.idents.append(ident)
                    thread.frames.append (CrashLog.Frame(int(frame_match.group(1)), int(frame_match.group(3), 0), frame_match.group(4)))
                else:
                    print 'error: frame regex failed for line: "%s"' % line
            elif parse_mode == PARSE_MODE_IMAGES:
                image_match = self.image_regex_uuid.search (line)
                if image_match:
                    image = CrashLog.DarwinImage (int(image_match.group(1),0), 
                                                  int(image_match.group(2),0), 
                                                  image_match.group(3).strip(), 
                                                  image_match.group(4).strip(), 
                                                  uuid.UUID(image_match.group(5)), 
                                                  image_match.group(6))
                    self.images.append (image)
                else:
                    image_match = self.image_regex_no_uuid.search (line)
                    if image_match:
                        image = CrashLog.DarwinImage (int(image_match.group(1),0), 
                                                      int(image_match.group(2),0), 
                                                      image_match.group(3).strip(), 
                                                      image_match.group(4).strip(), 
                                                      None,
                                                      image_match.group(5))
                        self.images.append (image)
                    else:
                        print "error: image regex failed for: %s" % line

            elif parse_mode == PARSE_MODE_THREGS:
                stripped_line = line.strip()
                # "r12: 0x00007fff6b5939c8  r13: 0x0000000007000006  r14: 0x0000000000002a03  r15: 0x0000000000000c00"
                reg_values = re.findall ('([a-zA-Z0-9]+: 0[Xx][0-9a-fA-F]+) *', stripped_line);
                for reg_value in reg_values:
                    #print 'reg_value = "%s"' % reg_value
                    (reg, value) = reg_value.split(': ')
                    #print 'reg = "%s"' % reg
                    #print 'value = "%s"' % value
                    thread.registers[reg.strip()] = int(value, 0)
            elif parse_mode == PARSE_MODE_SYSTEM:
                self.system_profile.append(line)
        f.close()
    
    def dump(self):
        print "Crash Log File: %s" % (self.path)
        print "\nThreads:"
        for thread in self.threads:
            thread.dump('  ')
        print "\nImages:"
        for image in self.images:
            image.dump('  ')
    
    def find_image_with_identifier(self, identifier):
        for image in self.images:
            if image.identifier == identifier:
                return image
        return None
    
    def create_target(self):
        #print 'crashlog.create_target()...'
        target = symbolication.Symbolicator.create_target(self)
        if target:
            return target
        # We weren't able to open the main executable as, but we can still symbolicate
        print 'crashlog.create_target()...2'
        if self.idents:
            for ident in self.idents:
                image = self.find_image_with_identifier (ident)
                if image:
                    target = image.create_target ()
                    if target:
                        return target # success
        print 'crashlog.create_target()...3'
        for image in self.images:
            target = image.create_target ()
            if target:
                return target # success
        print 'crashlog.create_target()...4'
        print 'error: unable to locate any executables from the crash log'
        return None
    

def usage():
    print "Usage: lldb-symbolicate.py [-n name] executable-image"
    sys.exit(0)

class Interactive(cmd.Cmd):
    '''Interactive prompt for analyzing one or more Darwin crash logs, type "help" to see a list of supported commands.'''
    image_option_parser = None
    
    def __init__(self, crash_logs):
        cmd.Cmd.__init__(self)
        self.use_rawinput = False
        self.intro = 'Interactive crashlogs prompt, type "help" to see a list of supported commands.'
        self.crash_logs = crash_logs
        self.prompt = '% '

    def default(self, line):
        '''Catch all for unknown command, which will exit the interpreter.'''
        print "uknown command: %s" % line
        return True

    def do_q(self, line):
        '''Quit command'''
        return True

    def do_quit(self, line):
        '''Quit command'''
        return True

    def do_symbolicate(self, line):
        description='''Symbolicate one or more darwin crash log files by index to provide source file and line information,
        inlined stack frames back to the concrete functions, and disassemble the location of the crash
        for the first frame of the crashed thread.'''
        option_parser = CreateSymbolicateCrashLogOptions ('symbolicate', description, False)
        command_args = shlex.split(line)
        try:
            (options, args) = option_parser.parse_args(command_args)
        except:
            return

        if args:
            # We have arguments, they must valid be crash log file indexes
            for idx_str in args:
                idx = int(idx_str)
                if idx < len(self.crash_logs):
                    SymbolicateCrashLog (self.crash_logs[idx], options)
                else:
                    print 'error: crash log index %u is out of range' % (idx)
        else:
            # No arguments, symbolicate all crash logs using the options provided
            for idx in range(len(self.crash_logs)):
                SymbolicateCrashLog (self.crash_logs[idx], options)                
    
    def do_list(self, line=None):
        '''Dump a list of all crash logs that are currently loaded.
        
        USAGE: list'''
        print '%u crash logs are loaded:' % len(self.crash_logs)
        for (crash_log_idx, crash_log) in enumerate(self.crash_logs):
            print '[%u] = %s' % (crash_log_idx, crash_log.path)

    def do_image(self, line):
        '''Dump information about one or more binary images in the crash log given an image basename, or all images if no arguments are provided.'''
        usage = "usage: %prog [options] <PATH> [PATH ...]"
        description='''Dump information about one or more images in all crash logs. The <PATH> can be a full path, image basename, or partial path. Searches are done in this order.'''
        command_args = shlex.split(line)
        if not self.image_option_parser:
            self.image_option_parser = optparse.OptionParser(description=description, prog='image',usage=usage)
            self.image_option_parser.add_option('-a', '--all', action='store_true', help='show all images', default=False)
        try:
            (options, args) = self.image_option_parser.parse_args(command_args)
        except:
            return
        
        if args:
            for image_path in args:
                fullpath_search = image_path[0] == '/'
                for (crash_log_idx, crash_log) in enumerate(self.crash_logs):
                    matches_found = 0
                    for (image_idx, image) in enumerate(crash_log.images):
                        if fullpath_search:
                            if image.get_resolved_path() == image_path:
                                matches_found += 1
                                print '[%u] ' % (crash_log_idx), image
                        else:
                            image_basename = image.get_resolved_path_basename()
                            if image_basename == image_path:
                                matches_found += 1
                                print '[%u] ' % (crash_log_idx), image
                    if matches_found == 0:
                        for (image_idx, image) in enumerate(crash_log.images):
                            resolved_image_path = image.get_resolved_path()
                            if resolved_image_path and string.find(image.get_resolved_path(), image_path) >= 0:
                                print '[%u] ' % (crash_log_idx), image
        else:
            for crash_log in self.crash_logs:
                for (image_idx, image) in enumerate(crash_log.images):
                    print '[%u] %s' % (image_idx, image)            
        return False


def interactive_crashlogs(options, args):
    crash_log_files = list()
    for arg in args:
        for resolved_path in glob.glob(arg):
            crash_log_files.append(resolved_path)
    
    crash_logs = list();
    for crash_log_file in crash_log_files:
        #print 'crash_log_file = "%s"' % crash_log_file
        crash_log = CrashLog(crash_log_file)
        if crash_log.error:
            print crash_log.error
            continue
        if options.debug:
            crash_log.dump()
        if not crash_log.images:
            print 'error: no images in crash log "%s"' % (crash_log)
            continue
        else:
            crash_logs.append(crash_log)
    
    interpreter = Interactive(crash_logs)
    # List all crash logs that were imported
    interpreter.do_list()
    interpreter.cmdloop()
    

def save_crashlog(debugger, command, result, dict):
    usage = "usage: %prog [options] <output-path>"
    description='''Export the state of current target into a crashlog file'''
    parser = optparse.OptionParser(description=description, prog='save_crashlog',usage=usage)
    parser.add_option('-v', '--verbose', action='store_true', dest='verbose', help='display verbose debug info', default=False)
    try:
        (options, args) = parser.parse_args(shlex.split(command))
    except:
        result.PutCString ("error: invalid options");
        return
    if len(args) != 1:
        result.PutCString ("error: invalid arguments, a single output file is the only valid argument")
        return
    out_file = open(args[0], 'w')
    if not out_file:
        result.PutCString ("error: failed to open file '%s' for writing...", args[0]);
        return
    if lldb.target:
        identifier = lldb.target.executable.basename
        if lldb.process:
            pid = lldb.process.id
            if pid != lldb.LLDB_INVALID_PROCESS_ID:
                out_file.write('Process:         %s [%u]\n' % (identifier, pid))
        out_file.write('Path:            %s\n' % (lldb.target.executable.fullpath))
        out_file.write('Identifier:      %s\n' % (identifier))
        out_file.write('\nDate/Time:       %s\n' % (datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")))
        out_file.write('OS Version:      Mac OS X %s (%s)\n' % (platform.mac_ver()[0], commands.getoutput('sysctl -n kern.osversion')));
        out_file.write('Report Version:  9\n')
        for thread_idx in range(lldb.process.num_threads):
            thread = lldb.process.thread[thread_idx]
            out_file.write('\nThread %u:\n' % (thread_idx))
            for (frame_idx, frame) in enumerate(thread.frames):
                frame_pc = frame.pc
                frame_offset = 0
                if frame.function:
                    block = frame.GetFrameBlock()
                    block_range = block.range[frame.addr]
                    if block_range:
                        block_start_addr = block_range[0]
                        frame_offset = frame_pc - block_start_addr.load_addr
                    else:
                        frame_offset = frame_pc - frame.function.addr.load_addr
                elif frame.symbol:
                    frame_offset = frame_pc - frame.symbol.addr.load_addr
                out_file.write('%-3u %-32s 0x%16.16x %s' % (frame_idx, frame.module.file.basename, frame_pc, frame.name))
                if frame_offset > 0: 
                    out_file.write(' + %u' % (frame_offset))
                line_entry = frame.line_entry
                if line_entry:
                    if options.verbose:
                        # This will output the fullpath + line + column
                        out_file.write(' %s' % (line_entry))
                    else:
                        out_file.write(' %s:%u' % (line_entry.file.basename, line_entry.line))
                        column = line_entry.column
                        if column: 
                            out_file.write(':%u' % (column))
                out_file.write('\n')
                
        out_file.write('\nBinary Images:\n')
        for module in lldb.target.modules:
            text_segment = module.section['__TEXT']
            if text_segment:
                text_segment_load_addr = text_segment.GetLoadAddress(lldb.target)
                if text_segment_load_addr != lldb.LLDB_INVALID_ADDRESS:
                    text_segment_end_load_addr = text_segment_load_addr + text_segment.size
                    identifier = module.file.basename
                    module_version = '???'
                    module_version_array = module.GetVersion()
                    if module_version_array:
                        module_version = '.'.join(map(str,module_version_array))
                    out_file.write ('    0x%16.16x - 0x%16.16x  %s (%s - ???) <%s> %s\n' % (text_segment_load_addr, text_segment_end_load_addr, identifier, module_version, module.GetUUIDString(), module.file.fullpath))
        out_file.close()
    else:
        result.PutCString ("error: invalid target");
        
    
def Symbolicate(debugger, command, result, dict):
    try:
        SymbolicateCrashLogs (shlex.split(command))
    except:
        result.PutCString ("error: python exception %s" % sys.exc_info()[0])

def SymbolicateCrashLog(crash_log, options):
    if crash_log.error:
        print crash_log.error
        return
    if options.debug:
        crash_log.dump()
    if not crash_log.images:
        print 'error: no images in crash log'
        return

    if options.dump_image_list:
        print "Binary Images:"
        for image in crash_log.images:
            if options.verbose:
                print image.debug_dump()
            else:
                print image

    target = crash_log.create_target ()
    if not target:
        return
    exe_module = target.GetModuleAtIndex(0)
    images_to_load = list()
    loaded_images = list()
    if options.load_all_images:
        # --load-all option was specified, load everything up
        for image in crash_log.images:
            images_to_load.append(image)
    else:
        # Only load the images found in stack frames for the crashed threads
        if options.crashed_only:
            for thread in crash_log.threads:
                if thread.did_crash():
                    for ident in thread.idents:
                        images = crash_log.find_images_with_identifier (ident)
                        if images:
                            for image in images:
                                images_to_load.append(image)
                        else:
                            print 'error: can\'t find image for identifier "%s"' % ident
        else:
            for ident in crash_log.idents:
                images = crash_log.find_images_with_identifier (ident)
                if images:
                    for image in images:
                        images_to_load.append(image)
                else:
                    print 'error: can\'t find image for identifier "%s"' % ident

    for image in images_to_load:
        if image in loaded_images:
            print "warning: skipping %s loaded at %#16.16x duplicate entry (probably commpage)" % (image.path, image.text_addr_lo)
        else:
            err = image.add_module (target)
            if err:
                print err
            else:
                #print 'loaded %s' % image
                loaded_images.append(image)

    for thread in crash_log.threads:
        this_thread_crashed = thread.did_crash()
        if options.crashed_only and this_thread_crashed == False:
            continue
        print "%s" % thread
        #prev_frame_index = -1
        display_frame_idx = -1
        for frame_idx, frame in enumerate(thread.frames):
            disassemble = (this_thread_crashed or options.disassemble_all_threads) and frame_idx < options.disassemble_depth;
            if frame_idx == 0:
                symbolicated_frame_addresses = crash_log.symbolicate (frame.pc & crash_log.addr_mask, options.verbose)
            else:
                # Any frame above frame zero and we have to subtract one to get the previous line entry
                symbolicated_frame_addresses = crash_log.symbolicate ((frame.pc & crash_log.addr_mask) - 1, options.verbose)
            
            if symbolicated_frame_addresses:
                symbolicated_frame_address_idx = 0
                for symbolicated_frame_address in symbolicated_frame_addresses:
                    display_frame_idx += 1
                    print '[%3u] %s' % (frame_idx, symbolicated_frame_address)
                    if (options.source_all or thread.did_crash()) and display_frame_idx < options.source_frames and options.source_context:
                        source_context = options.source_context
                        line_entry = symbolicated_frame_address.get_symbol_context().line_entry
                        if line_entry.IsValid():
                            strm = lldb.SBStream()
                            if line_entry:
                                lldb.debugger.GetSourceManager().DisplaySourceLinesWithLineNumbers(line_entry.file, line_entry.line, source_context, source_context, "->", strm)
                            source_text = strm.GetData()
                            if source_text:
                                # Indent the source a bit
                                indent_str = '    '
                                join_str = '\n' + indent_str
                                print '%s%s' % (indent_str, join_str.join(source_text.split('\n')))
                    if symbolicated_frame_address_idx == 0:
                        if disassemble:
                            instructions = symbolicated_frame_address.get_instructions()
                            if instructions:
                                print
                                symbolication.disassemble_instructions (target, 
                                                                        instructions, 
                                                                        frame.pc, 
                                                                        options.disassemble_before, 
                                                                        options.disassemble_after, frame.index > 0)
                                print
                    symbolicated_frame_address_idx += 1
            else:
                print frame
        print                

def CreateSymbolicateCrashLogOptions(command_name, description, add_interactive_options):
    usage = "usage: %prog [options] <FILE> [FILE ...]"
    option_parser = optparse.OptionParser(description=description, prog='crashlog',usage=usage)
    option_parser.add_option('--verbose'       , '-v', action='store_true', dest='verbose', help='display verbose debug info', default=False)
    option_parser.add_option('--debug'         , '-g', action='store_true', dest='debug', help='display verbose debug logging', default=False)
    option_parser.add_option('--load-all'      , '-a', action='store_true', dest='load_all_images', help='load all executable images, not just the images found in the crashed stack frames', default=False)
    option_parser.add_option('--images'        ,       action='store_true', dest='dump_image_list', help='show image list', default=False)
    option_parser.add_option('--debug-delay'   ,       type='int', dest='debug_delay', metavar='NSEC', help='pause for NSEC seconds for debugger', default=0)
    option_parser.add_option('--crashed-only'  , '-c', action='store_true', dest='crashed_only', help='only symbolicate the crashed thread', default=False)
    option_parser.add_option('--disasm-depth'  , '-d', type='int', dest='disassemble_depth', help='set the depth in stack frames that should be disassembled (default is 1)', default=1)
    option_parser.add_option('--disasm-all'    , '-D',  action='store_true', dest='disassemble_all_threads', help='enabled disassembly of frames on all threads (not just the crashed thread)', default=False)
    option_parser.add_option('--disasm-before' , '-B', type='int', dest='disassemble_before', help='the number of instructions to disassemble before the frame PC', default=4)
    option_parser.add_option('--disasm-after'  , '-A', type='int', dest='disassemble_after', help='the number of instructions to disassemble after the frame PC', default=4)
    option_parser.add_option('--source-context', '-C', type='int', metavar='NLINES', dest='source_context', help='show NLINES source lines of source context (default = 4)', default=4)
    option_parser.add_option('--source-frames' ,       type='int', metavar='NFRAMES', dest='source_frames', help='show source for NFRAMES (default = 4)', default=4)
    option_parser.add_option('--source-all'    ,       action='store_true', dest='source_all', help='show source for all threads, not just the crashed thread', default=False)
    if add_interactive_options:
        option_parser.add_option('-i', '--interactive', action='store_true', help='parse all crash logs and enter interactive mode', default=False)
    return option_parser
    
def SymbolicateCrashLogs(command_args):
    description='''Symbolicate one or more darwin crash log files to provide source file and line information,
inlined stack frames back to the concrete functions, and disassemble the location of the crash
for the first frame of the crashed thread.
If this script is imported into the LLDB command interpreter, a "crashlog" command will be added to the interpreter
for use at the LLDB command line. After a crash log has been parsed and symbolicated, a target will have been
created that has all of the shared libraries loaded at the load addresses found in the crash log file. This allows
you to explore the program as if it were stopped at the locations described in the crash log and functions can 
be disassembled and lookups can be performed using the addresses found in the crash log.'''
    option_parser = CreateSymbolicateCrashLogOptions ('crashlog', description, True)
    try:
        (options, args) = option_parser.parse_args(command_args)
    except:
        return
        
    if options.debug:
        print 'command_args = %s' % command_args
        print 'options', options
        print 'args', args
        
    if options.debug_delay > 0:
        print "Waiting %u seconds for debugger to attach..." % options.debug_delay
        time.sleep(options.debug_delay)
    error = lldb.SBError()
        
    if args:
        if options.interactive:
            interactive_crashlogs(options, args)
        else:
            for crash_log_file in args:
                crash_log = CrashLog(crash_log_file)
                SymbolicateCrashLog (crash_log, options)
if __name__ == '__main__':
    # Create a new debugger instance
    lldb.debugger = lldb.SBDebugger.Create()
    SymbolicateCrashLogs (sys.argv[1:])
elif getattr(lldb, 'debugger', None):
    lldb.debugger.HandleCommand('command script add -f lldb.macosx.crashlog.Symbolicate crashlog')
    lldb.debugger.HandleCommand('command script add -f lldb.macosx.crashlog.save_crashlog save_crashlog')
    print '"crashlog" and "save_crashlog" command installed, use the "--help" option for detailed help'