build/unix/rewrite_asan_dylib.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 import sys
   6 import os
   7 import subprocess
   8 import shutil
   9
  10 '''
  11 Scans the given directories for binaries referencing the AddressSanitizer
  12 runtime library, copies it to the main directory and rewrites binaries to not
  13 reference it with absolute paths but with @executable_path instead.
  14 '''
  15
  16 # This is the dylib we're looking for
  17 DYLIB_NAME='libclang_rt.asan_osx_dynamic.dylib'
  18
  19 def scan_directory(path):
  20     dylibCopied = False
  21
  22     for root, subdirs, files in os.walk(path):
  23         for filename in files:
  24             filename = os.path.join(root, filename)
  25
  26             # Skip all files that aren't either dylibs or executable
  27             if not (filename.endswith('.dylib') or os.access(filename, os.X_OK)):
  28                 continue
  29
  30             try:
  31                 otoolOut = subprocess.check_output(['otool', '-L', filename])
  32             except:
  33                 # Errors are expected on non-mach executables, ignore them and continue
  34                 continue
  35
  36             for line in otoolOut.splitlines():
  37                 if line.find(DYLIB_NAME) != -1:
  38                     absDylibPath = line.split()[0]
  39
  40                     # Don't try to rewrite binaries twice
  41                     if absDylibPath.find('@executable_path/') == 0:
  42                         continue
  43
  44                     if not dylibCopied:
  45                         # Copy the runtime once to the main directory, which is passed
  46                         # as the argument to this function.
  47                         shutil.copy(absDylibPath, path)
  48
  49                         # Now rewrite the library itself
  50                         subprocess.check_call(['install_name_tool', '-id', '@executable_path/' + DYLIB_NAME, os.path.join(path, DYLIB_NAME)])
  51                         dylibCopied = True
  52
  53                     # Now use install_name_tool to rewrite the path in our binary
  54                     subprocess.check_call(['install_name_tool', '-change', absDylibPath, '@executable_path/' + DYLIB_NAME, filename])
  55                     break
  56
  57 if __name__ == '__main__':
  58     for d in sys.argv[1:]:
  59         scan_directory(d)