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1"""distutils.extension
2
3Provides the Extension class, used to describe C/C++ extension
4modules in setup scripts."""
5
6import os
7import re
8import warnings
9
10# This class is really only used by the "build_ext" command, so it might
11# make sense to put it in distutils.command.build_ext.  However, that
12# module is already big enough, and I want to make this class a bit more
13# complex to simplify some common cases ("foo" module in "foo.c") and do
14# better error-checking ("foo.c" actually exists).
15#
16# Also, putting this in build_ext.py means every setup script would have to
17# import that large-ish module (indirectly, through distutils.core) in
18# order to do anything.
19
20class Extension:
21    """Just a collection of attributes that describes an extension
22    module and everything needed to build it (hopefully in a portable
23    way, but there are hooks that let you be as unportable as you need).
24
25    Instance attributes:
26      name : string
27        the full name of the extension, including any packages -- ie.
28        *not* a filename or pathname, but Python dotted name
29      sources : [string]
30        list of source filenames, relative to the distribution root
31        (where the setup script lives), in Unix form (slash-separated)
32        for portability.  Source files may be C, C++, SWIG (.i),
33        platform-specific resource files, or whatever else is recognized
34        by the "build_ext" command as source for a Python extension.
35      include_dirs : [string]
36        list of directories to search for C/C++ header files (in Unix
37        form for portability)
38      define_macros : [(name : string, value : string|None)]
39        list of macros to define; each macro is defined using a 2-tuple,
40        where 'value' is either the string to define it to or None to
41        define it without a particular value (equivalent of "#define
42        FOO" in source or -DFOO on Unix C compiler command line)
43      undef_macros : [string]
44        list of macros to undefine explicitly
45      library_dirs : [string]
46        list of directories to search for C/C++ libraries at link time
47      libraries : [string]
48        list of library names (not filenames or paths) to link against
49      runtime_library_dirs : [string]
50        list of directories to search for C/C++ libraries at run time
51        (for shared extensions, this is when the extension is loaded)
52      extra_objects : [string]
53        list of extra files to link with (eg. object files not implied
54        by 'sources', static library that must be explicitly specified,
55        binary resource files, etc.)
56      extra_compile_args : [string]
57        any extra platform- and compiler-specific information to use
58        when compiling the source files in 'sources'.  For platforms and
59        compilers where "command line" makes sense, this is typically a
60        list of command-line arguments, but for other platforms it could
61        be anything.
62      extra_link_args : [string]
63        any extra platform- and compiler-specific information to use
64        when linking object files together to create the extension (or
65        to create a new static Python interpreter).  Similar
66        interpretation as for 'extra_compile_args'.
67      export_symbols : [string]
68        list of symbols to be exported from a shared extension.  Not
69        used on all platforms, and not generally necessary for Python
70        extensions, which typically export exactly one symbol: "init" +
71        extension_name.
72      swig_opts : [string]
73        any extra options to pass to SWIG if a source file has the .i
74        extension.
75      depends : [string]
76        list of files that the extension depends on
77      language : string
78        extension language (i.e. "c", "c++", "objc"). Will be detected
79        from the source extensions if not provided.
80      optional : boolean
81        specifies that a build failure in the extension should not abort the
82        build process, but simply not install the failing extension.
83    """
84
85    # When adding arguments to this constructor, be sure to update
86    # setup_keywords in core.py.
87    def __init__(self, name, sources,
88                  include_dirs=None,
89                  define_macros=None,
90                  undef_macros=None,
91                  library_dirs=None,
92                  libraries=None,
93                  runtime_library_dirs=None,
94                  extra_objects=None,
95                  extra_compile_args=None,
96                  extra_link_args=None,
97                  export_symbols=None,
98                  swig_opts = None,
99                  depends=None,
100                  language=None,
101                  optional=None,
102                  **kw                      # To catch unknown keywords
103                 ):
104        if not isinstance(name, str):
105            raise AssertionError("'name' must be a string")
106        if not (isinstance(sources, list) and
107                all(isinstance(v, str) for v in sources)):
108            raise AssertionError("'sources' must be a list of strings")
109
110        self.name = name
111        self.sources = sources
112        self.include_dirs = include_dirs or []
113        self.define_macros = define_macros or []
114        self.undef_macros = undef_macros or []
115        self.library_dirs = library_dirs or []
116        self.libraries = libraries or []
117        self.runtime_library_dirs = runtime_library_dirs or []
118        self.extra_objects = extra_objects or []
119        self.extra_compile_args = extra_compile_args or []
120        self.extra_link_args = extra_link_args or []
121        self.export_symbols = export_symbols or []
122        self.swig_opts = swig_opts or []
123        self.depends = depends or []
124        self.language = language
125        self.optional = optional
126
127        # If there are unknown keyword options, warn about them
128        if len(kw) > 0:
129            options = [repr(option) for option in kw]
130            options = ', '.join(sorted(options))
131            msg = "Unknown Extension options: %s" % options
132            warnings.warn(msg)
133
134    def __repr__(self):
135        return '<%s.%s(%r) at %#x>' % (
136            self.__class__.__module__,
137            self.__class__.__qualname__,
138            self.name,
139            id(self))
140
141
142def read_setup_file(filename):
143    """Reads a Setup file and returns Extension instances."""
144    from distutils.sysconfig import (parse_makefile, expand_makefile_vars,
145                                     _variable_rx)
146
147    from distutils.text_file import TextFile
148    from distutils.util import split_quoted
149
150    # First pass over the file to gather "VAR = VALUE" assignments.
151    vars = parse_makefile(filename)
152
153    # Second pass to gobble up the real content: lines of the form
154    #   <module> ... [<sourcefile> ...] [<cpparg> ...] [<library> ...]
155    file = TextFile(filename,
156                    strip_comments=1, skip_blanks=1, join_lines=1,
157                    lstrip_ws=1, rstrip_ws=1)
158    try:
159        extensions = []
160
161        while True:
162            line = file.readline()
163            if line is None:                # eof
164                break
165            if re.match(_variable_rx, line):    # VAR=VALUE, handled in first pass
166                continue
167
168            if line[0] == line[-1] == "*":
169                file.warn("'%s' lines not handled yet" % line)
170                continue
171
172            line = expand_makefile_vars(line, vars)
173            words = split_quoted(line)
174
175            # NB. this parses a slightly different syntax than the old
176            # makesetup script: here, there must be exactly one extension per
177            # line, and it must be the first word of the line.  I have no idea
178            # why the old syntax supported multiple extensions per line, as
179            # they all wind up being the same.
180
181            module = words[0]
182            ext = Extension(module, [])
183            append_next_word = None
184
185            for word in words[1:]:
186                if append_next_word is not None:
187                    append_next_word.append(word)
188                    append_next_word = None
189                    continue
190
191                suffix = os.path.splitext(word)[1]
192                switch = word[0:2] ; value = word[2:]
193
194                if suffix in (".c", ".cc", ".cpp", ".cxx", ".c++", ".m", ".mm"):
195                    # hmm, should we do something about C vs. C++ sources?
196                    # or leave it up to the CCompiler implementation to
197                    # worry about?
198                    ext.sources.append(word)
199                elif switch == "-I":
200                    ext.include_dirs.append(value)
201                elif switch == "-D":
202                    equals = value.find("=")
203                    if equals == -1:        # bare "-DFOO" -- no value
204                        ext.define_macros.append((value, None))
205                    else:                   # "-DFOO=blah"
206                        ext.define_macros.append((value[0:equals],
207                                                  value[equals+2:]))
208                elif switch == "-U":
209                    ext.undef_macros.append(value)
210                elif switch == "-C":        # only here 'cause makesetup has it!
211                    ext.extra_compile_args.append(word)
212                elif switch == "-l":
213                    ext.libraries.append(value)
214                elif switch == "-L":
215                    ext.library_dirs.append(value)
216                elif switch == "-R":
217                    ext.runtime_library_dirs.append(value)
218                elif word == "-rpath":
219                    append_next_word = ext.runtime_library_dirs
220                elif word == "-Xlinker":
221                    append_next_word = ext.extra_link_args
222                elif word == "-Xcompiler":
223                    append_next_word = ext.extra_compile_args
224                elif switch == "-u":
225                    ext.extra_link_args.append(word)
226                    if not value:
227                        append_next_word = ext.extra_link_args
228                elif suffix in (".a", ".so", ".sl", ".o", ".dylib"):
229                    # NB. a really faithful emulation of makesetup would
230                    # append a .o file to extra_objects only if it
231                    # had a slash in it; otherwise, it would s/.o/.c/
232                    # and append it to sources.  Hmmmm.
233                    ext.extra_objects.append(word)
234                else:
235                    file.warn("unrecognized argument '%s'" % word)
236
237            extensions.append(ext)
238    finally:
239        file.close()
240
241    return extensions
242