Lib/distutils/extension.py

   1 """distutils.extension
   2
   3 Provides the Extension class, used to describe C/C++ extension
   4 modules in setup scripts."""
   5
   6 __revision__ = "$Id$"
   7
   8 import os
   9 import warnings
  10
  11 # This class is really only used by the "build_ext" command, so it might
  12 # make sense to put it in distutils.command.build_ext.  However, that
  13 # module is already big enough, and I want to make this class a bit more
  14 # complex to simplify some common cases ("foo" module in "foo.c") and do
  15 # better error-checking ("foo.c" actually exists).
  16 #
  17 # Also, putting this in build_ext.py means every setup script would have to
  18 # import that large-ish module (indirectly, through distutils.core) in
  19 # order to do anything.
  20
  21 class Extension:
  22     """Just a collection of attributes that describes an extension
  23     module and everything needed to build it (hopefully in a portable
  24     way, but there are hooks that let you be as unportable as you need).
  25
  26     Instance attributes:
  27       name : string
  28         the full name of the extension, including any packages -- ie.
  29         *not* a filename or pathname, but Python dotted name
  30       sources : [string]
  31         list of source filenames, relative to the distribution root
  32         (where the setup script lives), in Unix form (slash-separated)
  33         for portability.  Source files may be C, C++, SWIG (.i),
  34         platform-specific resource files, or whatever else is recognized
  35         by the "build_ext" command as source for a Python extension.
  36       include_dirs : [string]
  37         list of directories to search for C/C++ header files (in Unix
  38         form for portability)
  39       define_macros : [(name : string, value : string|None)]
  40         list of macros to define; each macro is defined using a 2-tuple,
  41         where 'value' is either the string to define it to or None to
  42         define it without a particular value (equivalent of "#define
  43         FOO" in source or -DFOO on Unix C compiler command line)
  44       undef_macros : [string]
  45         list of macros to undefine explicitly
  46       library_dirs : [string]
  47         list of directories to search for C/C++ libraries at link time
  48       libraries : [string]
  49         list of library names (not filenames or paths) to link against
  50       runtime_library_dirs : [string]
  51         list of directories to search for C/C++ libraries at run time
  52         (for shared extensions, this is when the extension is loaded)
  53       extra_objects : [string]
  54         list of extra files to link with (eg. object files not implied
  55         by 'sources', static library that must be explicitly specified,
  56         binary resource files, etc.)
  57       extra_compile_args : [string]
  58         any extra platform- and compiler-specific information to use
  59         when compiling the source files in 'sources'.  For platforms and
  60         compilers where "command line" makes sense, this is typically a
  61         list of command-line arguments, but for other platforms it could
  62         be anything.
  63       extra_link_args : [string]
  64         any extra platform- and compiler-specific information to use
  65         when linking object files together to create the extension (or
  66         to create a new static Python interpreter).  Similar
  67         interpretation as for 'extra_compile_args'.
  68       export_symbols : [string]
  69         list of symbols to be exported from a shared extension.  Not
  70         used on all platforms, and not generally necessary for Python
  71         extensions, which typically export exactly one symbol: "init" +
  72         extension_name.
  73       swig_opts : [string]
  74         any extra options to pass to SWIG if a source file has the .i
  75         extension.
  76       depends : [string]
  77         list of files that the extension depends on
  78       language : string
  79         extension language (i.e. "c", "c++", "objc"). Will be detected
  80         from the source extensions if not provided.
  81       optional : boolean
  82         specifies that a build failure in the extension should not abort the
  83         build process, but simply not install the failing extension.
  84     """
  85
  86     # When adding arguments to this constructor, be sure to update
  87     # setup_keywords in core.py.
  88     def __init__ (self, name, sources,
  89                   include_dirs=None,
  90                   define_macros=None,
  91                   undef_macros=None,
  92                   library_dirs=None,
  93                   libraries=None,
  94                   runtime_library_dirs=None,
  95                   extra_objects=None,
  96                   extra_compile_args=None,
  97                   extra_link_args=None,
  98                   export_symbols=None,
  99                   swig_opts = None,
 100                   depends=None,
 101                   language=None,
 102                   optional=None,
 103                   **kw                      # To catch unknown keywords
 104                  ):
 105         if not isinstance(name, str):
 106             raise AssertionError("'name' must be a string")
 107         if not (isinstance(sources, list) and
 108                 all(isinstance(v, str) for v in sources)):
 109             raise AssertionError("'sources' must be a list of strings")
 110
 111         self.name = name
 112         self.sources = sources
 113         self.include_dirs = include_dirs or []
 114         self.define_macros = define_macros or []
 115         self.undef_macros = undef_macros or []
 116         self.library_dirs = library_dirs or []
 117         self.libraries = libraries or []
 118         self.runtime_library_dirs = runtime_library_dirs or []
 119         self.extra_objects = extra_objects or []
 120         self.extra_compile_args = extra_compile_args or []
 121         self.extra_link_args = extra_link_args or []
 122         self.export_symbols = export_symbols or []
 123         self.swig_opts = swig_opts or []
 124         self.depends = depends or []
 125         self.language = language
 126         self.optional = optional
 127
 128         # If there are unknown keyword options, warn about them
 129         if len(kw) > 0:
 130             options = [repr(option) for option in kw]
 131             options = ', '.join(sorted(options))
 132             msg = "Unknown Extension options: %s" % options
 133             warnings.warn(msg)
 134
 135 def read_setup_file(filename):
 136     """Reads a Setup file and returns Extension instances."""
 137     from distutils.sysconfig import (parse_makefile, expand_makefile_vars,
 138                                      _variable_rx)
 139
 140     from distutils.text_file import TextFile
 141     from distutils.util import split_quoted
 142
 143     # First pass over the file to gather "VAR = VALUE" assignments.
 144     vars = parse_makefile(filename)
 145
 146     # Second pass to gobble up the real content: lines of the form
 147     #   <module> ... [<sourcefile> ...] [<cpparg> ...] [<library> ...]
 148     file = TextFile(filename,
 149                     strip_comments=1, skip_blanks=1, join_lines=1,
 150                     lstrip_ws=1, rstrip_ws=1)
 151     extensions = []
 152
 153     while 1:
 154         line = file.readline()
 155         if line is None:                # eof
 156             break
 157         if _variable_rx.match(line):    # VAR=VALUE, handled in first pass
 158             continue
 159
 160         if line[0] == line[-1] == "*":
 161             file.warn("'%s' lines not handled yet" % line)
 162             continue
 163
 164         line = expand_makefile_vars(line, vars)
 165         words = split_quoted(line)
 166
 167         # NB. this parses a slightly different syntax than the old
 168         # makesetup script: here, there must be exactly one extension per
 169         # line, and it must be the first word of the line.  I have no idea
 170         # why the old syntax supported multiple extensions per line, as
 171         # they all wind up being the same.
 172
 173         module = words[0]
 174         ext = Extension(module, [])
 175         append_next_word = None
 176
 177         for word in words[1:]:
 178             if append_next_word is not None:
 179                 append_next_word.append(word)
 180                 append_next_word = None
 181                 continue
 182
 183             suffix = os.path.splitext(word)[1]
 184             switch = word[0:2] ; value = word[2:]
 185
 186             if suffix in (".c", ".cc", ".cpp", ".cxx", ".c++", ".m", ".mm"):
 187                 # hmm, should we do something about C vs. C++ sources?
 188                 # or leave it up to the CCompiler implementation to
 189                 # worry about?
 190                 ext.sources.append(word)
 191             elif switch == "-I":
 192                 ext.include_dirs.append(value)
 193             elif switch == "-D":
 194                 equals = value.find("=")
 195                 if equals == -1:        # bare "-DFOO" -- no value
 196                     ext.define_macros.append((value, None))
 197                 else:                   # "-DFOO=blah"
 198                     ext.define_macros.append((value[0:equals],
 199                                               value[equals+2:]))
 200             elif switch == "-U":
 201                 ext.undef_macros.append(value)
 202             elif switch == "-C":        # only here 'cause makesetup has it!
 203                 ext.extra_compile_args.append(word)
 204             elif switch == "-l":
 205                 ext.libraries.append(value)
 206             elif switch == "-L":
 207                 ext.library_dirs.append(value)
 208             elif switch == "-R":
 209                 ext.runtime_library_dirs.append(value)
 210             elif word == "-rpath":
 211                 append_next_word = ext.runtime_library_dirs
 212             elif word == "-Xlinker":
 213                 append_next_word = ext.extra_link_args
 214             elif word == "-Xcompiler":
 215                 append_next_word = ext.extra_compile_args
 216             elif switch == "-u":
 217                 ext.extra_link_args.append(word)
 218                 if not value:
 219                     append_next_word = ext.extra_link_args
 220             elif suffix in (".a", ".so", ".sl", ".o", ".dylib"):
 221                 # NB. a really faithful emulation of makesetup would
 222                 # append a .o file to extra_objects only if it
 223                 # had a slash in it; otherwise, it would s/.o/.c/
 224                 # and append it to sources.  Hmmmm.
 225                 ext.extra_objects.append(word)
 226             else:
 227                 file.warn("unrecognized argument '%s'" % word)
 228
 229         extensions.append(ext)
 230
 231     return extensions