1 #!/usr/bin/env python 2 3 # Copyright (c) 2011 The Chromium Authors. All rights reserved. 4 # Use of this source code is governed by a BSD-style license that can be 5 # found in the LICENSE file. 6 7 # Usage: strip_save_dsym <whatever-arguments-you-would-pass-to-strip> 8 # 9 # strip_save_dsym is a wrapper around the standard strip utility. Given an 10 # input Mach-O file, strip_save_dsym will save a copy of the file in a "fake" 11 # .dSYM bundle for debugging, and then call strip to strip the Mach-O file. 12 # Note that the .dSYM file is a "fake" in that it's not a self-contained 13 # .dSYM bundle, it just contains a copy of the original (unstripped) Mach-O 14 # file, and therefore contains references to object files on the filesystem. 15 # The generated .dSYM bundle is therefore unsuitable for debugging in the 16 # absence of these .o files. 17 # 18 # If a .dSYM already exists and has a newer timestamp than the Mach-O file, 19 # this utility does nothing. That allows strip_save_dsym to be run on a file 20 # that has already been stripped without trashing the .dSYM. 21 # 22 # Rationale: the "right" way to generate dSYM bundles, dsymutil, is incredibly 23 # slow. On the other hand, doing a file copy (which is really all that 24 # dsymutil does) is comparatively fast. Since we usually just want to strip 25 # a release-mode executable but still be able to debug it, and we don't care 26 # so much about generating a hermetic dSYM bundle, we'll prefer the file copy. 27 # If a real dSYM is ever needed, it's still possible to create one by running 28 # dsymutil and pointing it at the original Mach-O file inside the "fake" 29 # bundle, provided that the object files are available. 30 31 import errno 32 import os 33 import re 34 import shutil 35 import subprocess 36 import sys 37 import time 38 39 # Returns a list of architectures contained in a Mach-O file. The file can be 40 # a universal (fat) file, in which case there will be one list element for 41 # each contained architecture, or it can be a thin single-architecture Mach-O 42 # file, in which case the list will contain a single element identifying the 43 # architecture. On error, returns an empty list. Determines the architecture 44 # list by calling file. 45 def macho_archs(macho): 46 macho_types = ["executable", 47 "dynamically linked shared library", 48 "bundle"] 49 macho_types_re = "Mach-O (?:64-bit )?(?:" + "|".join(macho_types) + ")" 50 51 file_cmd = subprocess.Popen(["/usr/bin/file", "-b", "--", macho], 52 stdout=subprocess.PIPE) 53 54 archs = [] 55 56 type_line = file_cmd.stdout.readline() 57 type_match = re.match("^%s (.*)$" % macho_types_re, type_line) 58 if type_match: 59 archs.append(type_match.group(1)) 60 return [type_match.group(1)] 61 else: 62 type_match = re.match("^Mach-O universal binary with (.*) architectures$", 63 type_line) 64 if type_match: 65 for i in range(0, int(type_match.group(1))): 66 arch_line = file_cmd.stdout.readline() 67 arch_match = re.match( 68 "^.* \(for architecture (.*)\):\t%s .*$" % macho_types_re, 69 arch_line) 70 if arch_match: 71 archs.append(arch_match.group(1)) 72 73 if file_cmd.wait() != 0: 74 archs = [] 75 76 if len(archs) == 0: 77 print >> sys.stderr, "No architectures in %s" % macho 78 79 return archs 80 81 # Returns a dictionary mapping architectures contained in the file as returned 82 # by macho_archs to the LC_UUID load command for that architecture. 83 # Architectures with no LC_UUID load command are omitted from the dictionary. 84 # Determines the UUID value by calling otool. 85 def macho_uuids(macho): 86 uuids = {} 87 88 archs = macho_archs(macho) 89 if len(archs) == 0: 90 return uuids 91 92 for arch in archs: 93 if arch == "": 94 continue 95 96 otool_cmd = subprocess.Popen(["/usr/bin/otool", "-arch", arch, "-l", "-", 97 macho], 98 stdout=subprocess.PIPE) 99 # state 0 is when nothing UUID-related has been seen yet. State 1 is 100 # entered after a load command begins, but it may not be an LC_UUID load 101 # command. States 2, 3, and 4 are intermediate states while reading an 102 # LC_UUID command. State 5 is the terminal state for a successful LC_UUID 103 # read. State 6 is the error state. 104 state = 0 105 uuid = "" 106 for otool_line in otool_cmd.stdout: 107 if state == 0: 108 if re.match("^Load command .*$", otool_line): 109 state = 1 110 elif state == 1: 111 if re.match("^ cmd LC_UUID$", otool_line): 112 state = 2 113 else: 114 state = 0 115 elif state == 2: 116 if re.match("^ cmdsize 24$", otool_line): 117 state = 3 118 else: 119 state = 6 120 elif state == 3: 121 # The UUID display format changed in the version of otool shipping 122 # with the Xcode 3.2.2 prerelease. The new format is traditional: 123 # uuid 4D7135B2-9C56-C5F5-5F49-A994258E0955 124 # and with Xcode 3.2.6, then line is indented one more space: 125 # uuid 4D7135B2-9C56-C5F5-5F49-A994258E0955 126 # The old format, from cctools-750 and older's otool, breaks the UUID 127 # up into a sequence of bytes: 128 # uuid 0x4d 0x71 0x35 0xb2 0x9c 0x56 0xc5 0xf5 129 # 0x5f 0x49 0xa9 0x94 0x25 0x8e 0x09 0x55 130 new_uuid_match = re.match("^ {3,4}uuid (.{8}-.{4}-.{4}-.{4}-.{12})$", 131 otool_line) 132 if new_uuid_match: 133 uuid = new_uuid_match.group(1) 134 135 # Skip state 4, there is no second line to read. 136 state = 5 137 else: 138 old_uuid_match = re.match("^ uuid 0x(..) 0x(..) 0x(..) 0x(..) " 139 "0x(..) 0x(..) 0x(..) 0x(..)$", 140 otool_line) 141 if old_uuid_match: 142 state = 4 143 uuid = old_uuid_match.group(1) + old_uuid_match.group(2) + \ 144 old_uuid_match.group(3) + old_uuid_match.group(4) + "-" + \ 145 old_uuid_match.group(5) + old_uuid_match.group(6) + "-" + \ 146 old_uuid_match.group(7) + old_uuid_match.group(8) + "-" 147 else: 148 state = 6 149 elif state == 4: 150 old_uuid_match = re.match("^ 0x(..) 0x(..) 0x(..) 0x(..) " 151 "0x(..) 0x(..) 0x(..) 0x(..)$", 152 otool_line) 153 if old_uuid_match: 154 state = 5 155 uuid += old_uuid_match.group(1) + old_uuid_match.group(2) + "-" + \ 156 old_uuid_match.group(3) + old_uuid_match.group(4) + \ 157 old_uuid_match.group(5) + old_uuid_match.group(6) + \ 158 old_uuid_match.group(7) + old_uuid_match.group(8) 159 else: 160 state = 6 161 162 if otool_cmd.wait() != 0: 163 state = 6 164 165 if state == 5: 166 uuids[arch] = uuid.upper() 167 168 if len(uuids) == 0: 169 print >> sys.stderr, "No UUIDs in %s" % macho 170 171 return uuids 172 173 # Given a path to a Mach-O file and possible information from the environment, 174 # determines the desired path to the .dSYM. 175 def dsym_path(macho): 176 # If building a bundle, the .dSYM should be placed next to the bundle. Use 177 # WRAPPER_NAME to make this determination. If called from xcodebuild, 178 # WRAPPER_NAME will be set to the name of the bundle. 179 dsym = "" 180 if "WRAPPER_NAME" in os.environ: 181 if "BUILT_PRODUCTS_DIR" in os.environ: 182 dsym = os.path.join(os.environ["BUILT_PRODUCTS_DIR"], 183 os.environ["WRAPPER_NAME"]) 184 else: 185 dsym = os.environ["WRAPPER_NAME"] 186 else: 187 dsym = macho 188 189 dsym += ".dSYM" 190 191 return dsym 192 193 # Creates a fake .dSYM bundle at dsym for macho, a Mach-O image with the 194 # architectures and UUIDs specified by the uuids map. 195 def make_fake_dsym(macho, dsym): 196 uuids = macho_uuids(macho) 197 if len(uuids) == 0: 198 return False 199 200 dwarf_dir = os.path.join(dsym, "Contents", "Resources", "DWARF") 201 dwarf_file = os.path.join(dwarf_dir, os.path.basename(macho)) 202 try: 203 os.makedirs(dwarf_dir) 204 except OSError, (err, error_string): 205 if err != errno.EEXIST: 206 raise 207 shutil.copyfile(macho, dwarf_file) 208 209 # info_template is the same as what dsymutil would have written, with the 210 # addition of the fake_dsym key. 211 info_template = \ 212 '''<?xml version="1.0" encoding="UTF-8"?> 213 <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> 214 <plist version="1.0"> 215 <dict> 216 <key>CFBundleDevelopmentRegion</key> 217 <string>English</string> 218 <key>CFBundleIdentifier</key> 219 <string>com.apple.xcode.dsym.%(root_name)s</string> 220 <key>CFBundleInfoDictionaryVersion</key> 221 <string>6.0</string> 222 <key>CFBundlePackageType</key> 223 <string>dSYM</string> 224 <key>CFBundleSignature</key> 225 <string>????</string> 226 <key>CFBundleShortVersionString</key> 227 <string>1.0</string> 228 <key>CFBundleVersion</key> 229 <string>1</string> 230 <key>dSYM_UUID</key> 231 <dict> 232 %(uuid_dict)s </dict> 233 <key>fake_dsym</key> 234 <true/> 235 </dict> 236 </plist> 237 ''' 238 239 root_name = os.path.basename(dsym)[:-5] # whatever.dSYM without .dSYM 240 uuid_dict = "" 241 for arch in sorted(uuids): 242 uuid_dict += "\t\t\t<key>" + arch + "</key>\n"\ 243 "\t\t\t<string>" + uuids[arch] + "</string>\n" 244 info_dict = { 245 "root_name": root_name, 246 "uuid_dict": uuid_dict, 247 } 248 info_contents = info_template % info_dict 249 info_file = os.path.join(dsym, "Contents", "Info.plist") 250 info_fd = open(info_file, "w") 251 info_fd.write(info_contents) 252 info_fd.close() 253 254 return True 255 256 # For a Mach-O file, determines where the .dSYM bundle should be located. If 257 # the bundle does not exist or has a modification time older than the Mach-O 258 # file, calls make_fake_dsym to create a fake .dSYM bundle there, then strips 259 # the Mach-O file and sets the modification time on the .dSYM bundle and Mach-O 260 # file to be identical. 261 def strip_and_make_fake_dsym(macho): 262 dsym = dsym_path(macho) 263 macho_stat = os.stat(macho) 264 dsym_stat = None 265 try: 266 dsym_stat = os.stat(dsym) 267 except OSError, (err, error_string): 268 if err != errno.ENOENT: 269 raise 270 271 if dsym_stat is None or dsym_stat.st_mtime < macho_stat.st_mtime: 272 # Make a .dSYM bundle 273 if not make_fake_dsym(macho, dsym): 274 return False 275 276 # Strip the Mach-O file 277 remove_dsym = True 278 try: 279 strip_cmdline = ['xcrun', 'strip'] + sys.argv[1:] 280 strip_cmd = subprocess.Popen(strip_cmdline) 281 if strip_cmd.wait() == 0: 282 remove_dsym = False 283 finally: 284 if remove_dsym: 285 shutil.rmtree(dsym) 286 287 # Update modification time on the Mach-O file and .dSYM bundle 288 now = time.time() 289 os.utime(macho, (now, now)) 290 os.utime(dsym, (now, now)) 291 292 return True 293 294 def main(argv=None): 295 if argv is None: 296 argv = sys.argv 297 298 # This only supports operating on one file at a time. Look at the arguments 299 # to strip to figure out what the source to be stripped is. Arguments are 300 # processed in the same way that strip does, although to reduce complexity, 301 # this doesn't do all of the same checking as strip. For example, strip 302 # has no -Z switch and would treat -Z on the command line as an error. For 303 # the purposes this is needed for, that's fine. 304 macho = None 305 process_switches = True 306 ignore_argument = False 307 for arg in argv[1:]: 308 if ignore_argument: 309 ignore_argument = False 310 continue 311 if process_switches: 312 if arg == "-": 313 process_switches = False 314 # strip has these switches accept an argument: 315 if arg in ["-s", "-R", "-d", "-o", "-arch"]: 316 ignore_argument = True 317 if arg[0] == "-": 318 continue 319 if macho is None: 320 macho = arg 321 else: 322 print >> sys.stderr, "Too many things to strip" 323 return 1 324 325 if macho is None: 326 print >> sys.stderr, "Nothing to strip" 327 return 1 328 329 if not strip_and_make_fake_dsym(macho): 330 return 1 331 332 return 0 333 334 if __name__ == "__main__": 335 sys.exit(main(sys.argv)) 336
