security/nss/coreconf/werror.py

   1 #!/usr/bin/env python
   2
   3 import os
   4 import subprocess
   5
   6 def main():
   7     cc = os.environ.get('CC', 'cc')
   8     sink = open(os.devnull, 'wb')
   9     try:
  10         cc_is_clang = 'clang' in subprocess.check_output(
  11           [cc, '--version'], universal_newlines=True, stderr=sink)
  12     except OSError:
  13         # We probably just don't have CC/cc.
  14         return
  15
  16     def warning_supported(warning):
  17         return subprocess.call([cc, '-x', 'c', '-E', '-Werror',
  18                                 '-W%s' % warning, os.devnull], stdout=sink, stderr=sink) == 0
  19     def can_enable():
  20         # This would be a problem
  21         if not warning_supported('all'):
  22             return False
  23
  24         # If we aren't clang, make sure we have gcc 4.8 at least
  25         if not cc_is_clang:
  26             try:
  27                 v = subprocess.check_output([cc, '-dumpversion'], stderr=sink).decode("utf-8")
  28                 v = v.strip(' \r\n').split('.')
  29                 v = list(map(int, v))
  30                 if v[0] < 4 or (v[0] == 4 and v[1] < 8):
  31                     # gcc 4.8 minimum
  32                     return False
  33             except OSError:
  34                 return False
  35         return True
  36
  37     if not can_enable():
  38         print('-DNSS_NO_GCC48')
  39         return
  40
  41     print('-Werror')
  42     print('-Wall')
  43
  44     def set_warning(warning, contra=''):
  45         if warning_supported(warning):
  46             print('-W%s%s' % (contra, warning))
  47
  48     if cc_is_clang:
  49         # clang is unable to handle glib's expansion of strcmp and similar for
  50         # optimized builds, so disable the resulting errors.
  51         # See https://llvm.org/bugs/show_bug.cgi?id=20144
  52         for w in ['array-bounds',
  53                   'unevaluated-expression',
  54                   'parentheses-equality',
  55                   'tautological-type-limit-compare',
  56                   'sign-compare',
  57                   'comma',
  58                   'implicit-fallthrough'
  59                   ]:
  60             set_warning(w, 'no-')
  61         for w in ['tautological-constant-in-range-compare',
  62                   'bitfield-enum-conversion',
  63                   'empty-body',
  64                   'format-type-confusion',
  65                   'ignored-qualifiers',
  66                   'pointer-arith',
  67                   'type-limits',
  68                   'unreachable-code',
  69                   'unreachable-code-return',
  70                   'duplicated-cond',
  71                   'logical-op',
  72                   'implicit-function-declaration'
  73                   ]:
  74             set_warning(w,'')
  75         print('-Qunused-arguments')
  76
  77     set_warning('shadow')
  78
  79 if __name__ == '__main__':
  80     main()