sys-devel/llvm/files/wrapper_script_common

from __future__ import print_function

# We need to be very careful about adding imports to this function, as the
# imports will increase execution time, and this is called for every
# compiler invocation.

import os
import sys

WRAPPER_ONLY_OPTIONS = set((
    '-print-cmdline',
    '-nopie',
    '-noccache',
    '-clang-syntax',
))

X86_DISABLE_FLAGS = set(['-mno-movbe'])

# GCC flags to remove from the clang command line.
# TODO: Once clang supports GCC compatibility mode, remove
# these checks.
#
# Use of -Qunused-arguments allows this set to be small, just those
# that clang still warns about.
CLANG_UNSUPPORTED = set((
    '-pass-exit-codes',
    '-Wclobbered',
    '-Wunsafe-loop-optimizations',
    '-Wlogical-op',
    '-Wmissing-parameter-type',
    '-Woverride-init',
    '-Wold-style-declaration',
    '-Wno-psabi',
    '-mno-movbe',
))

# Flags not supported by GCC.
GCC_UNSUPPORTED = set(['-Xcompiler'])

# Flags not supported by sanitizers (ASan etc.)
LINKER_UNSUPPORTED_ASAN_FLAGS = set((
    '-Wl,--no-undefined',
    '-Wl,-z,defs',
))

CLANG_UNSUPPORTED_PREFIXES = ('-Wstrict-aliasing=', '-finline-limit=')

# clang with '-ftrapv' generates 'call __mulodi4', which is only implemented
# in compiler-rt library. However compiler-rt library only has i386/x86_64
# backends (see '/usr/lib/clang/3.7.0/lib/linux/libclang_rt.*'). GCC, on the
# other hand, generate 'call __mulvdi3', which is implemented in libgcc. See
# bug chromium:503229.
CLANG_ARM_OPTIONS_TO_BE_DISCARDED = set(['-ftrapv'])

# Clang may use different options for the same or similar functionality.
GCC_TO_CLANG = {
    '-Wno-error=unused-but-set-variable': '-Wno-error=unused-variable',
    '-Wno-error=maybe-uninitialized': '-Wno-error=uninitialized',
    '-Wno-unused-but-set-variable': '-Wno-unused-variable',
    '-Wunused-but-set-variable': '-Wunused-variable',
    '-Wno-error=cpp': '-Wno-#warnings',
}

def handle_exec_exception(exc, argv0, use_ccache, execargs):
  """Analyze compiler execution errors."""
  import errno

  if use_ccache and exc.errno == errno.ENOENT:
    print('error: make sure you install ccache\n', file=sys.stderr)
  print(
      'error: execution of (%s, %s) failed' % (argv0, execargs),
      file=sys.stderr)
  raise

def has_sanitizer_flags(args):
  """Returns true if ASan/MSan flags are present."""
  if any([x.startswith('-fsanitize') for x in args]):
    return True
  return False

def startswith_i86(s):
  """Returns true if s starts with i.86."""
  return s[0] + s[2:4] == 'i86'

def find_source_file(arg_list):
  """Find c source file in arg list, if it exists."""

  c_endings = ('.c', '.cc', '.cpp', '.C', '.cxx', '.c++')
  num_args = len(arg_list)
  i = 1 # Start with second arg
  while i < num_args:
    arg = arg_list[i]
    for ext in c_endings:
      if arg.endswith(ext) and arg_list[i-1] != '-o':
        return arg
    i += 1

  return ''