"""distutils.extension

Provides the Extension class, used to describe C/C++ extension
modules in setup scripts."""

import os
import warnings

# 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.
 """

 # When adding arguments to this constructor, be sure to update
 # setup_keywords in core.py.
 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 # To catch unknown keywords
 ):
 if not isinstance(name, str):
 raise AssertionError("'name' must be a string")
 if not (isinstance(sources, list) and
 all(isinstance(v, str) for v in sources)):
 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))
 msg = "Unknown Extension options: %s" % options
 warnings.warn(msg)

 def __repr__(self):
 return '<%s.%s(%r) at %#x>' % (
 self.__class__.__module__,
 self.__class__.__qualname__,
 self.name,
 id(self))


def read_setup_file(filename):
 """Reads a Setup file and returns Extension instances."""
 from distutils.sysconfig import (parse_makefile, expand_makefile_vars,
 _variable_rx)

 from distutils.text_file import TextFile
 from distutils.util import split_quoted

 # First pass over the file to gather "VAR = VALUE" assignments.
 vars = parse_makefile(filename)

 # Second pass to gobble up the real content: lines of the form
 # <module> ... [<sourcefile> ...] [<cpparg> ...] [<library> ...]
 file = TextFile(filename,
 strip_comments=1, skip_blanks=1, join_lines=1,
 lstrip_ws=1, rstrip_ws=1)
 try:
 extensions = []

 while True:
 line = file.readline()
 if line is None: # eof
 break
 if _variable_rx.match(line): # VAR=VALUE, handled in first pass
 continue

 if line[0] == line[-1] == "*":
 file.warn("'%s' lines not handled yet" % line)
 continue

 line = expand_makefile_vars(line, vars)
 words = split_quoted(line)

 # NB. this parses a slightly different syntax than the old
 # makesetup script: here, there must be exactly one extension per
 # line, and it must be the first word of the line. I have no idea
 # why the old syntax supported multiple extensions per line, as
 # they all wind up being the same.

 module = words[0]
 ext = Extension(module, [])
 append_next_word = None

 for word in words[1:]:
 if append_next_word is not None:
 append_next_word.append(word)
 append_next_word = None
 continue

 suffix = os.path.splitext(word)[1]
 switch = word[0:2] ; value = word[2:]

 if suffix in (".c", ".cc", ".cpp", ".cxx", ".c++", ".m", ".mm"):
 # hmm, should we do something about C vs. C++ sources?
 # or leave it up to the CCompiler implementation to
 # worry about?
 ext.sources.append(word)
 elif switch == "-I":
 ext.include_dirs.append(value)
 elif switch == "-D":
 equals = value.find("=")
 if equals == -1: # bare "-DFOO" -- no value
 ext.define_macros.append((value, None))
 else: # "-DFOO=blah"
 ext.define_macros.append((value[0:equals],
 value[equals+2:]))
 elif switch == "-U":
 ext.undef_macros.append(value)
 elif switch == "-C": # only here 'cause makesetup has it!
 ext.extra_compile_args.append(word)
 elif switch == "-l":
 ext.libraries.append(value)
 elif switch == "-L":
 ext.library_dirs.append(value)
 elif switch == "-R":
 ext.runtime_library_dirs.append(value)
 elif word == "-rpath":
 append_next_word = ext.runtime_library_dirs
 elif word == "-Xlinker":
 append_next_word = ext.extra_link_args
 elif word == "-Xcompiler":
 append_next_word = ext.extra_compile_args
 elif switch == "-u":
 ext.extra_link_args.append(word)
 if not value:
 append_next_word = ext.extra_link_args
 elif suffix in (".a", ".so", ".sl", ".o", ".dylib"):
 # NB. a really faithful emulation of makesetup would
 # append a .o file to extra_objects only if it
 # had a slash in it; otherwise, it would s/.o/.c/
 # and append it to sources. Hmmmm.
 ext.extra_objects.append(word)
 else:
 file.warn("unrecognized argument '%s'" % word)

 extensions.append(ext)
 finally:
 file.close()

 return extensions