1"""distutils.extension
2
3Provides the Extension class, used to describe C/C++ extension
4modules in setup scripts."""
5
6import os
7import warnings
8
9# This class is really only used by the "build_ext" command, so it might
10# make sense to put it in distutils.command.build_ext.  However, that
11# module is already big enough, and I want to make this class a bit more
12# complex to simplify some common cases ("foo" module in "foo.c") and do
13# better error-checking ("foo.c" actually exists).
14#
15# Also, putting this in build_ext.py means every setup script would have to
16# import that large-ish module (indirectly, through distutils.core) in
17# order to do anything.
18
19class Extension:
20    """Just a collection of attributes that describes an extension
21    module and everything needed to build it (hopefully in a portable
22    way, but there are hooks that let you be as unportable as you need).
23
24    Instance attributes:
25      name : string
26        the full name of the extension, including any packages -- ie.
27        *not* a filename or pathname, but Python dotted name
28      sources : [string]
29        list of source filenames, relative to the distribution root
30        (where the setup script lives), in Unix form (slash-separated)
31        for portability.  Source files may be C, C++, SWIG (.i),
32        platform-specific resource files, or whatever else is recognized
33        by the "build_ext" command as source for a Python extension.
34      include_dirs : [string]
35        list of directories to search for C/C++ header files (in Unix
36        form for portability)
37      define_macros : [(name : string, value : string|None)]
38        list of macros to define; each macro is defined using a 2-tuple,
39        where 'value' is either the string to define it to or None to
40        define it without a particular value (equivalent of "#define
41        FOO" in source or -DFOO on Unix C compiler command line)
42      undef_macros : [string]
43        list of macros to undefine explicitly
44      library_dirs : [string]
45        list of directories to search for C/C++ libraries at link time
46      libraries : [string]
47        list of library names (not filenames or paths) to link against
48      runtime_library_dirs : [string]
49        list of directories to search for C/C++ libraries at run time
50        (for shared extensions, this is when the extension is loaded)
51      extra_objects : [string]
52        list of extra files to link with (eg. object files not implied
53        by 'sources', static library that must be explicitly specified,
54        binary resource files, etc.)
55      extra_compile_args : [string]
56        any extra platform- and compiler-specific information to use
57        when compiling the source files in 'sources'.  For platforms and
58        compilers where "command line" makes sense, this is typically a
59        list of command-line arguments, but for other platforms it could
60        be anything.
61      extra_link_args : [string]
62        any extra platform- and compiler-specific information to use
63        when linking object files together to create the extension (or
64        to create a new static Python interpreter).  Similar
65        interpretation as for 'extra_compile_args'.
66      export_symbols : [string]
67        list of symbols to be exported from a shared extension.  Not
68        used on all platforms, and not generally necessary for Python
69        extensions, which typically export exactly one symbol: "init" +
70        extension_name.
71      swig_opts : [string]
72        any extra options to pass to SWIG if a source file has the .i
73        extension.
74      depends : [string]
75        list of files that the extension depends on
76      language : string
77        extension language (i.e. "c", "c++", "objc"). Will be detected
78        from the source extensions if not provided.
79      optional : boolean
80        specifies that a build failure in the extension should not abort the
81        build process, but simply not install the failing extension.
82    """
83
84    # When adding arguments to this constructor, be sure to update
85    # setup_keywords in core.py.
86    def __init__(self, name, sources,
87                  include_dirs=None,
88                  define_macros=None,
89                  undef_macros=None,
90                  library_dirs=None,
91                  libraries=None,
92                  runtime_library_dirs=None,
93                  extra_objects=None,
94                  extra_compile_args=None,
95                  extra_link_args=None,
96                  export_symbols=None,
97                  swig_opts = None,
98                  depends=None,
99                  language=None,
100                  optional=None,
101                  **kw                      # To catch unknown keywords
102                 ):
103        if not isinstance(name, str):
104            raise AssertionError("'name' must be a string")
105        if not (isinstance(sources, list) and
106                all(isinstance(v, str) for v in sources)):
107            raise AssertionError("'sources' must be a list of strings")
108
109        self.name = name
110        self.sources = sources
111        self.include_dirs = include_dirs or []
112        self.define_macros = define_macros or []
113        self.undef_macros = undef_macros or []
114        self.library_dirs = library_dirs or []
115        self.libraries = libraries or []
116        self.runtime_library_dirs = runtime_library_dirs or []
117        self.extra_objects = extra_objects or []
118        self.extra_compile_args = extra_compile_args or []
119        self.extra_link_args = extra_link_args or []
120        self.export_symbols = export_symbols or []
121        self.swig_opts = swig_opts or []
122        self.depends = depends or []
123        self.language = language
124        self.optional = optional
125
126        # If there are unknown keyword options, warn about them
127        if len(kw) > 0:
128            options = [repr(option) for option in kw]
129            options = ', '.join(sorted(options))
130            msg = "Unknown Extension options: %s" % options
131            warnings.warn(msg)
132
133    def __repr__(self):
134        return '<%s.%s(%r) at %#x>' % (
135            self.__class__.__module__,
136            self.__class__.__qualname__,
137            self.name,
138            id(self))
139
140
141def read_setup_file(filename):
142    """Reads a Setup file and returns Extension instances."""
143    from distutils.sysconfig import (parse_makefile, expand_makefile_vars,
144                                     _variable_rx)
145
146    from distutils.text_file import TextFile
147    from distutils.util import split_quoted
148
149    # First pass over the file to gather "VAR = VALUE" assignments.
150    vars = parse_makefile(filename)
151
152    # Second pass to gobble up the real content: lines of the form
153    #   <module> ... [<sourcefile> ...] [<cpparg> ...] [<library> ...]
154    file = TextFile(filename,
155                    strip_comments=1, skip_blanks=1, join_lines=1,
156                    lstrip_ws=1, rstrip_ws=1)
157    try:
158        extensions = []
159
160        while True:
161            line = file.readline()
162            if line is None:                # eof
163                break
164            if _variable_rx.match(line):    # VAR=VALUE, handled in first pass
165                continue
166
167            if line[0] == line[-1] == "*":
168                file.warn("'%s' lines not handled yet" % line)
169                continue
170
171            line = expand_makefile_vars(line, vars)
172            words = split_quoted(line)
173
174            # NB. this parses a slightly different syntax than the old
175            # makesetup script: here, there must be exactly one extension per
176            # line, and it must be the first word of the line.  I have no idea
177            # why the old syntax supported multiple extensions per line, as
178            # they all wind up being the same.
179
180            module = words[0]
181            ext = Extension(module, [])
182            append_next_word = None
183
184            for word in words[1:]:
185                if append_next_word is not None:
186                    append_next_word.append(word)
187                    append_next_word = None
188                    continue
189
190                suffix = os.path.splitext(word)[1]
191                switch = word[0:2] ; value = word[2:]
192
193                if suffix in (".c", ".cc", ".cpp", ".cxx", ".c++", ".m", ".mm"):
194                    # hmm, should we do something about C vs. C++ sources?
195                    # or leave it up to the CCompiler implementation to
196                    # worry about?
197                    ext.sources.append(word)
198                elif switch == "-I":
199                    ext.include_dirs.append(value)
200                elif switch == "-D":
201                    equals = value.find("=")
202                    if equals == -1:        # bare "-DFOO" -- no value
203                        ext.define_macros.append((value, None))
204                    else:                   # "-DFOO=blah"
205                        ext.define_macros.append((value[0:equals],
206                                                  value[equals+2:]))
207                elif switch == "-U":
208                    ext.undef_macros.append(value)
209                elif switch == "-C":        # only here 'cause makesetup has it!
210                    ext.extra_compile_args.append(word)
211                elif switch == "-l":
212                    ext.libraries.append(value)
213                elif switch == "-L":
214                    ext.library_dirs.append(value)
215                elif switch == "-R":
216                    ext.runtime_library_dirs.append(value)
217                elif word == "-rpath":
218                    append_next_word = ext.runtime_library_dirs
219                elif word == "-Xlinker":
220                    append_next_word = ext.extra_link_args
221                elif word == "-Xcompiler":
222                    append_next_word = ext.extra_compile_args
223                elif switch == "-u":
224                    ext.extra_link_args.append(word)
225                    if not value:
226                        append_next_word = ext.extra_link_args
227                elif suffix in (".a", ".so", ".sl", ".o", ".dylib"):
228                    # NB. a really faithful emulation of makesetup would
229                    # append a .o file to extra_objects only if it
230                    # had a slash in it; otherwise, it would s/.o/.c/
231                    # and append it to sources.  Hmmmm.
232                    ext.extra_objects.append(word)
233                else:
234                    file.warn("unrecognized argument '%s'" % word)
235
236            extensions.append(ext)
237    finally:
238        file.close()
239
240    return extensions
241