blob: 0b0bc7b1d76458a0dae48204f9d306c94fcde213 [file] [log] [blame]
#!/usr/bin/env python3
# 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.
# Usage: strip_save_dsym <whatever-arguments-you-would-pass-to-strip>
# strip_save_dsym is a wrapper around the standard strip utility. Given an
# input Mach-O file, strip_save_dsym will save a copy of the file in a "fake"
# .dSYM bundle for debugging, and then call strip to strip the Mach-O file.
# Note that the .dSYM file is a "fake" in that it's not a self-contained
# .dSYM bundle, it just contains a copy of the original (unstripped) Mach-O
# file, and therefore contains references to object files on the filesystem.
# The generated .dSYM bundle is therefore unsuitable for debugging in the
# absence of these .o files.
# If a .dSYM already exists and has a newer timestamp than the Mach-O file,
# this utility does nothing. That allows strip_save_dsym to be run on a file
# that has already been stripped without trashing the .dSYM.
# Rationale: the "right" way to generate dSYM bundles, dsymutil, is incredibly
# slow. On the other hand, doing a file copy (which is really all that
# dsymutil does) is comparatively fast. Since we usually just want to strip
# a release-mode executable but still be able to debug it, and we don't care
# so much about generating a hermetic dSYM bundle, we'll prefer the file copy.
# If a real dSYM is ever needed, it's still possible to create one by running
# dsymutil and pointing it at the original Mach-O file inside the "fake"
# bundle, provided that the object files are available.
import errno
import os
import re
import shutil
import subprocess
import sys
import time
# Returns a list of architectures contained in a Mach-O file. The file can be
# a universal (fat) file, in which case there will be one list element for
# each contained architecture, or it can be a thin single-architecture Mach-O
# file, in which case the list will contain a single element identifying the
# architecture. On error, returns an empty list. Determines the architecture
# list by calling file.
def macho_archs(macho):
macho_types = ["executable",
"dynamically linked shared library",
macho_types_re = "Mach-O (?:64-bit )?(?:" + "|".join(macho_types) + ")"
file_cmd = subprocess.Popen(["/usr/bin/file", "-b", "--", macho],
archs = []
type_line = file_cmd.stdout.readline()
type_match = re.match("^%s (.*)$" % macho_types_re, type_line)
if type_match:
return []
type_match = re.match("^Mach-O universal binary with (.*) architectures$",
if type_match:
for i in range(0, int(
arch_line = file_cmd.stdout.readline()
arch_match = re.match(
"^.* \(for architecture (.*)\):\t%s .*$" % macho_types_re,
if arch_match:
if file_cmd.wait() != 0:
archs = []
if len(archs) == 0:
print >> sys.stderr, "No architectures in %s" % macho
return archs
# Returns a dictionary mapping architectures contained in the file as returned
# by macho_archs to the LC_UUID load command for that architecture.
# Architectures with no LC_UUID load command are omitted from the dictionary.
# Determines the UUID value by calling otool.
def macho_uuids(macho):
uuids = {}
archs = macho_archs(macho)
if len(archs) == 0:
return uuids
for arch in archs:
if arch == "":
otool_cmd = subprocess.Popen(["/usr/bin/otool", "-arch", arch, "-l", "-",
# state 0 is when nothing UUID-related has been seen yet. State 1 is
# entered after a load command begins, but it may not be an LC_UUID load
# command. States 2, 3, and 4 are intermediate states while reading an
# LC_UUID command. State 5 is the terminal state for a successful LC_UUID
# read. State 6 is the error state.
state = 0
uuid = ""
for otool_line in otool_cmd.stdout:
if state == 0:
if re.match("^Load command .*$", otool_line):
state = 1
elif state == 1:
if re.match("^ cmd LC_UUID$", otool_line):
state = 2
state = 0
elif state == 2:
if re.match("^ cmdsize 24$", otool_line):
state = 3
state = 6
elif state == 3:
# The UUID display format changed in the version of otool shipping
# with the Xcode 3.2.2 prerelease. The new format is traditional:
# uuid 4D7135B2-9C56-C5F5-5F49-A994258E0955
# and with Xcode 3.2.6, then line is indented one more space:
# uuid 4D7135B2-9C56-C5F5-5F49-A994258E0955
# The old format, from cctools-750 and older's otool, breaks the UUID
# up into a sequence of bytes:
# uuid 0x4d 0x71 0x35 0xb2 0x9c 0x56 0xc5 0xf5
# 0x5f 0x49 0xa9 0x94 0x25 0x8e 0x09 0x55
new_uuid_match = re.match("^ {3,4}uuid (.{8}-.{4}-.{4}-.{4}-.{12})$",
if new_uuid_match:
uuid =
# Skip state 4, there is no second line to read.
state = 5
old_uuid_match = re.match("^ uuid 0x(..) 0x(..) 0x(..) 0x(..) "
"0x(..) 0x(..) 0x(..) 0x(..)$",
if old_uuid_match:
state = 4
uuid = + + \ + + "-" + \ + + "-" + \ + + "-"
state = 6
elif state == 4:
old_uuid_match = re.match("^ 0x(..) 0x(..) 0x(..) 0x(..) "
"0x(..) 0x(..) 0x(..) 0x(..)$",
if old_uuid_match:
state = 5
uuid += + + "-" + \ + + \ + + \ +
state = 6
if otool_cmd.wait() != 0:
state = 6
if state == 5:
uuids[arch] = uuid.upper()
if len(uuids) == 0:
print >> sys.stderr, "No UUIDs in %s" % macho
return uuids
# Given a path to a Mach-O file and possible information from the environment,
# determines the desired path to the .dSYM.
def dsym_path(macho):
# If building a bundle, the .dSYM should be placed next to the bundle. Use
# WRAPPER_NAME to make this determination. If called from xcodebuild,
# WRAPPER_NAME will be set to the name of the bundle.
dsym = ""
if "WRAPPER_NAME" in os.environ:
if "BUILT_PRODUCTS_DIR" in os.environ:
dsym = os.path.join(os.environ["BUILT_PRODUCTS_DIR"],
dsym = os.environ["WRAPPER_NAME"]
dsym = macho
dsym += ".dSYM"
return dsym
# Creates a fake .dSYM bundle at dsym for macho, a Mach-O image with the
# architectures and UUIDs specified by the uuids map.
def make_fake_dsym(macho, dsym):
uuids = macho_uuids(macho)
if len(uuids) == 0:
return False
dwarf_dir = os.path.join(dsym, "Contents", "Resources", "DWARF")
dwarf_file = os.path.join(dwarf_dir, os.path.basename(macho))
except OSError, (err, error_string):
if err != errno.EEXIST:
shutil.copyfile(macho, dwarf_file)
# info_template is the same as what dsymutil would have written, with the
# addition of the fake_dsym key.
info_template = \
'''<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "">
<plist version="1.0">
%(uuid_dict)s </dict>
root_name = os.path.basename(dsym)[:-5] # whatever.dSYM without .dSYM
uuid_dict = ""
for arch in sorted(uuids):
uuid_dict += "\t\t\t<key>" + arch + "</key>\n"\
"\t\t\t<string>" + uuids[arch] + "</string>\n"
info_dict = {
"root_name": root_name,
"uuid_dict": uuid_dict,
info_contents = info_template % info_dict
info_file = os.path.join(dsym, "Contents", "Info.plist")
info_fd = open(info_file, "w")
return True
# For a Mach-O file, determines where the .dSYM bundle should be located. If
# the bundle does not exist or has a modification time older than the Mach-O
# file, calls make_fake_dsym to create a fake .dSYM bundle there, then strips
# the Mach-O file and sets the modification time on the .dSYM bundle and Mach-O
# file to be identical.
def strip_and_make_fake_dsym(macho):
dsym = dsym_path(macho)
macho_stat = os.stat(macho)
dsym_stat = None
dsym_stat = os.stat(dsym)
except OSError, (err, error_string):
if err != errno.ENOENT:
if dsym_stat is None or dsym_stat.st_mtime < macho_stat.st_mtime:
# Make a .dSYM bundle
if not make_fake_dsym(macho, dsym):
return False
# Strip the Mach-O file
remove_dsym = True
strip_cmdline = ['xcrun', 'strip'] + sys.argv[1:]
strip_cmd = subprocess.Popen(strip_cmdline)
if strip_cmd.wait() == 0:
remove_dsym = False
if remove_dsym:
# Update modification time on the Mach-O file and .dSYM bundle
now = time.time()
os.utime(macho, (now, now))
os.utime(dsym, (now, now))
return True
def main(argv=None):
if argv is None:
argv = sys.argv
# This only supports operating on one file at a time. Look at the arguments
# to strip to figure out what the source to be stripped is. Arguments are
# processed in the same way that strip does, although to reduce complexity,
# this doesn't do all of the same checking as strip. For example, strip
# has no -Z switch and would treat -Z on the command line as an error. For
# the purposes this is needed for, that's fine.
macho = None
process_switches = True
ignore_argument = False
for arg in argv[1:]:
if ignore_argument:
ignore_argument = False
if process_switches:
if arg == "-":
process_switches = False
# strip has these switches accept an argument:
if arg in ["-s", "-R", "-d", "-o", "-arch"]:
ignore_argument = True
if arg[0] == "-":
if macho is None:
macho = arg
print >> sys.stderr, "Too many things to strip"
return 1
if macho is None:
print >> sys.stderr, "Nothing to strip"
return 1
if not strip_and_make_fake_dsym(macho):
return 1
return 0
if __name__ == "__main__":