unixccompiler.py

"""distutils.unixccompiler

Contains the UnixCCompiler class, a subclass of CCompiler that handles
the "typical" Unix-style command-line C compiler:
  * macros defined with -Dname[=value]
  * macros undefined with -Uname
  * include search directories specified with -Idir
  * libraries specified with -lllib
  * library search directories specified with -Ldir
  * compile handled by 'cc' (or similar) executable with -c option:
    compiles .c to .o
  * link static library handled by 'ar' command (possibly with 'ranlib')
  * link shared library handled by 'cc -shared'
"""

import os, sys

from distutils.dep_util import newer
from distutils.ccompiler import CCompiler, gen_preprocess_options
from distutils.errors import DistutilsExecError, CompileError

# XXX Things not currently handled:
#   * optimization/debug/warning flags; we just use whatever's in Python's
#     Makefile and live with it.  Is this adequate?  If not, we might
#     have to have a bunch of subclasses GNUCCompiler, SGICCompiler,
#     SunCCompiler, and I suspect down that road lies madness.
#   * even if we don't know a warning flag from an optimization flag,
#     we need some way for outsiders to feed preprocessor/compiler/linker
#     flags in to us -- eg. a sysadmin might want to mandate certain flags
#     via a site config file, or a user might want to set something for
#     compiling this module distribution only via the setup.py command
#     line, whatever.  As long as these options come from something on the
#     current system, they can be as system-dependent as they like, and we
#     should just happily stuff them into the preprocessor/compiler/linker
#     options and carry on.


class UnixCCompiler(CCompiler):

    compiler_type = 'unix'

    # These are used by CCompiler in two places: the constructor sets
    # instance attributes 'preprocessor', 'compiler', etc. from them, and
    # 'set_executable()' allows any of these to be set.  The defaults here
    # are pretty generic; they will probably have to be set by an outsider
    # (eg. using information discovered by the sysconfig about building
    # Python extensions).
    executables = {'preprocessor' : None,
                   'compiler'     : ["cc"],
                   'compiler_so'  : ["cc"],
                   'compiler_cxx' : ["cc"],
                   'linker_so'    : ["cc", "-shared"],
                   'linker_exe'   : ["cc"],
                   'archiver'     : ["ar", "-cr"],
                   'ranlib'       : None,
                  }

    if sys.platform[:6] == "darwin":
        executables['ranlib'] = ["ranlib"]

    # Needed for the filename generation methods provided by the base
    # class, CCompiler.  NB. whoever instantiates/uses a particular
    # UnixCCompiler instance should set 'shared_lib_ext' -- we set a
    # reasonable common default here, but it's not necessarily used on all
    # Unices!

    src_extensions = [".c",".C",".cc",".cxx",".cpp",".m"]
    obj_extension = ".o"
    static_lib_extension = ".a"
    shared_lib_extension = ".so"
    dylib_lib_extension = ".dylib"
    xcode_stub_lib_extension = ".tbd"
    static_lib_format = shared_lib_format = dylib_lib_format = "lib%s%s"
    xcode_stub_lib_format = dylib_lib_format
    if sys.platform == "cygwin":
        exe_extension = ".exe"

    def preprocess(self, source, output_file=None, macros=None,
                   include_dirs=None, extra_preargs=None, extra_postargs=None):
        fixed_args = self._fix_compile_args(None, macros, include_dirs)
        ignore, macros, include_dirs = fixed_args
        pp_opts = gen_preprocess_options(macros, include_dirs)
        pp_args = self.preprocessor + pp_opts
        if output_file:
            pp_args.extend(['-o', output_file])
        if extra_preargs:
            pp_args[:0] = extra_preargs
        if extra_postargs:
            pp_args.extend(extra_postargs)
        pp_args.append(source)

        # We need to preprocess: either we're being forced to, or we're
        # generating output to stdout, or there's a target output file and
        # the source file is newer than the target (or the target doesn't
        # exist).
        if self.force or output_file is None or newer(source, output_file):
            if output_file:
                self.mkpath(os.path.dirname(output_file))
            try:
                self.spawn(pp_args)
            except DistutilsExecError as msg:
                raise CompileError(msg)