initial import of the packaging package in the standard library
diff --git a/Lib/packaging/compiler/extension.py b/Lib/packaging/compiler/extension.py
new file mode 100644
index 0000000..66f6e9a
--- /dev/null
+++ b/Lib/packaging/compiler/extension.py
@@ -0,0 +1,121 @@
+"""Class representing C/C++ extension modules."""
+
+from packaging import logger
+
+# This class is really only used by the "build_ext" command, so it might
+# make sense to put it in distutils.command.build_ext. However, that
+# module is already big enough, and I want to make this class a bit more
+# complex to simplify some common cases ("foo" module in "foo.c") and do
+# better error-checking ("foo.c" actually exists).
+#
+# Also, putting this in build_ext.py means every setup script would have to
+# import that large-ish module (indirectly, through distutils.core) in
+# order to do anything.
+
+
+class Extension:
+ """Just a collection of attributes that describes an extension
+ module and everything needed to build it (hopefully in a portable
+ way, but there are hooks that let you be as unportable as you need).
+
+ Instance attributes:
+ name : string
+ the full name of the extension, including any packages -- ie.
+ *not* a filename or pathname, but Python dotted name
+ sources : [string]
+ list of source filenames, relative to the distribution root
+ (where the setup script lives), in Unix form (slash-separated)
+ for portability. Source files may be C, C++, SWIG (.i),
+ platform-specific resource files, or whatever else is recognized
+ by the "build_ext" command as source for a Python extension.
+ include_dirs : [string]
+ list of directories to search for C/C++ header files (in Unix
+ form for portability)
+ define_macros : [(name : string, value : string|None)]
+ list of macros to define; each macro is defined using a 2-tuple,
+ where 'value' is either the string to define it to or None to
+ define it without a particular value (equivalent of "#define
+ FOO" in source or -DFOO on Unix C compiler command line)
+ undef_macros : [string]
+ list of macros to undefine explicitly
+ library_dirs : [string]
+ list of directories to search for C/C++ libraries at link time
+ libraries : [string]
+ list of library names (not filenames or paths) to link against
+ runtime_library_dirs : [string]
+ list of directories to search for C/C++ libraries at run time
+ (for shared extensions, this is when the extension is loaded)
+ extra_objects : [string]
+ list of extra files to link with (eg. object files not implied
+ by 'sources', static library that must be explicitly specified,
+ binary resource files, etc.)
+ extra_compile_args : [string]
+ any extra platform- and compiler-specific information to use
+ when compiling the source files in 'sources'. For platforms and
+ compilers where "command line" makes sense, this is typically a
+ list of command-line arguments, but for other platforms it could
+ be anything.
+ extra_link_args : [string]
+ any extra platform- and compiler-specific information to use
+ when linking object files together to create the extension (or
+ to create a new static Python interpreter). Similar
+ interpretation as for 'extra_compile_args'.
+ export_symbols : [string]
+ list of symbols to be exported from a shared extension. Not
+ used on all platforms, and not generally necessary for Python
+ extensions, which typically export exactly one symbol: "init" +
+ extension_name.
+ swig_opts : [string]
+ any extra options to pass to SWIG if a source file has the .i
+ extension.
+ depends : [string]
+ list of files that the extension depends on
+ language : string
+ extension language (i.e. "c", "c++", "objc"). Will be detected
+ from the source extensions if not provided.
+ optional : boolean
+ specifies that a build failure in the extension should not abort the
+ build process, but simply not install the failing extension.
+ """
+
+ # **kwargs are allowed so that a warning is emitted instead of an
+ # exception
+ def __init__(self, name, sources, include_dirs=None, define_macros=None,
+ undef_macros=None, library_dirs=None, libraries=None,
+ runtime_library_dirs=None, extra_objects=None,
+ extra_compile_args=None, extra_link_args=None,
+ export_symbols=None, swig_opts=None, depends=None,
+ language=None, optional=None, **kw):
+ if not isinstance(name, str):
+ raise AssertionError("'name' must be a string")
+
+ if not isinstance(sources, list):
+ raise AssertionError("'sources' must be a list of strings")
+
+ for v in sources:
+ if not isinstance(v, str):
+ raise AssertionError("'sources' must be a list of strings")
+
+ self.name = name
+ self.sources = sources
+ self.include_dirs = include_dirs or []
+ self.define_macros = define_macros or []
+ self.undef_macros = undef_macros or []
+ self.library_dirs = library_dirs or []
+ self.libraries = libraries or []
+ self.runtime_library_dirs = runtime_library_dirs or []
+ self.extra_objects = extra_objects or []
+ self.extra_compile_args = extra_compile_args or []
+ self.extra_link_args = extra_link_args or []
+ self.export_symbols = export_symbols or []
+ self.swig_opts = swig_opts or []
+ self.depends = depends or []
+ self.language = language
+ self.optional = optional
+
+ # If there are unknown keyword options, warn about them
+ if len(kw) > 0:
+ options = [repr(option) for option in kw]
+ options = ', '.join(sorted(options))
+ logger.warning(
+ 'unknown arguments given to Extension: %s', options)