2 # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 The SCons Foundation
4 # Permission is hereby granted, free of charge, to any person obtaining
5 # a copy of this software and associated documentation files (the
6 # "Software"), to deal in the Software without restriction, including
7 # without limitation the rights to use, copy, modify, merge, publish,
8 # distribute, sublicense, and/or sell copies of the Software, and to
9 # permit persons to whom the Software is furnished to do so, subject to
10 # the following conditions:
12 # The above copyright notice and this permission notice shall be included
13 # in all copies or substantial portions of the Software.
15 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
16 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
17 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 SCons compatibility package for old Python versions
27 This subpackage holds modules that provide backwards-compatible
28 implementations of various things that we'd like to use in SCons but which
29 only show up in later versions of Python than the early, old version(s)
32 Other code will not generally reference things in this package through
33 the SCons.compat namespace. The modules included here add things to
34 the __builtin__ namespace or the global module list so that the rest
35 of our code can use the objects and names imported here regardless of
38 Simply enough, things that go in the __builtin__ name space come from
41 The rest of the things here will be in individual compatibility modules
42 that are either: 1) suitably modified copies of the future modules that
43 we want to use; or 2) backwards compatible re-implementations of the
44 specific portions of a future module's API that we want to use.
46 GENERAL WARNINGS: Implementations of functions in the SCons.compat
47 modules are *NOT* guaranteed to be fully compliant with these functions in
48 later versions of Python. We are only concerned with adding functionality
49 that we actually use in SCons, so be wary if you lift this code for
50 other uses. (That said, making these more nearly the same as later,
51 official versions is still a desirable goal, we just don't need to be
54 We name the compatibility modules with an initial '_scons_' (for example,
55 _scons_subprocess.py is our compatibility module for subprocess) so
56 that we can still try to import the real module name and fall back to
57 our compatibility module if we get an ImportError. The import_as()
58 function defined below loads the module as the "real" name (without the
59 '_scons'), after which all of the "import {module}" statements in the
60 rest of our code will find our pre-loaded compatibility module.
63 __revision__ = "src/engine/SCons/compat/__init__.py 3842 2008/12/20 22:59:52 scons"
65 def import_as(module, name):
67 Imports the specified module (from our local directory) as the
72 dir = os.path.split(__file__)[0]
73 file, filename, suffix_mode_type = imp.find_module(module, [dir])
74 imp.load_module(name, file, filename, suffix_mode_type)
81 # Pre-2.5 Python has no hashlib module.
83 import_as('_scons_hashlib', 'hashlib')
85 # If we failed importing our compatibility module, it probably
86 # means this version of Python has no md5 module. Don't do
87 # anything and let the higher layer discover this fact, so it
88 # can fall back to using timestamp.
94 # Pre-2.4 Python has no native set type
96 # Python 2.2 and 2.3 can use the copy of the 2.[45] sets module
98 import_as('_scons_sets', 'sets')
99 except (ImportError, SyntaxError):
100 # Python 1.5 (ImportError, no __future_ module) and 2.1
101 # (SyntaxError, no generators in __future__) will blow up
102 # trying to import the 2.[45] sets module, so back off to a
103 # custom sets module that can be discarded easily when we
104 # stop supporting those versions.
105 import_as('_scons_sets15', 'sets')
108 __builtin__.set = sets.Set
113 except AttributeError:
114 # Pre-2.2 Python has no fnmatch.filter() function.
115 def filter(names, pat):
116 """Return the subset of the list NAMES that match PAT"""
119 pat = os.path.normcase(pat)
120 if not fnmatch._cache.has_key(pat):
122 res = fnmatch.translate(pat)
123 fnmatch._cache[pat] = re.compile(res)
124 match = fnmatch._cache[pat].match
125 if os.path is posixpath:
126 # normcase on posix is NOP. Optimize it away from the loop.
132 if match(os.path.normcase(name)):
135 fnmatch.filter = filter
141 # Pre-2.3 Python has no itertools module.
142 import_as('_scons_itertools', 'itertools')
144 # If we need the compatibility version of textwrap, it must be imported
145 # before optparse, which uses it.
149 # Pre-2.3 Python has no textwrap module.
150 import_as('_scons_textwrap', 'textwrap')
155 # Pre-2.3 Python has no optparse module.
156 import_as('_scons_optparse', 'optparse')
161 except AttributeError:
162 # Pre-2.4 Python has no os.devnull attribute
164 _names = sys.builtin_module_names
165 if 'posix' in _names:
166 os.devnull = '/dev/null'
169 os.path.devnull = os.devnull
174 except AttributeError:
175 # Pre-2.3 Python has no shlex.split() function.
177 # The full white-space splitting semantics of shlex.split() are
178 # complicated to reproduce by hand, so just use a compatibility
179 # version of the shlex module cribbed from Python 2.5 with some
180 # minor modifications for older Python versions.
182 import_as('_scons_shlex', 'shlex')
188 except AttributeError:
189 # Pre-2.3 Python has no shutil.move() function.
191 # Cribbed from Python 2.5.
195 """Recursively move a file or directory to another location.
197 If the destination is on our current filesystem, then simply use
198 rename. Otherwise, copy src to the dst and then remove src.
199 A lot more could be done here... A look at a mv.c shows a lot of
200 the issues this implementation glosses over.
206 if os.path.isdir(src):
207 if shutil.destinsrc(src, dst):
208 raise Error, "Cannot move a directory '%s' into itself '%s'." % (src, dst)
209 shutil.copytree(src, dst, symlinks=True)
212 shutil.copy2(src,dst)
217 def destinsrc(src, dst):
218 src = os.path.abspath(src)
219 return os.path.abspath(dst)[:len(src)] == src
220 shutil.destinsrc = destinsrc
227 # Pre-2.4 Python has no subprocess module.
228 import_as('_scons_subprocess', 'subprocess')
233 except AttributeError:
234 # Pre-1.6 Python has no sys.version_info
236 version_string = string.split(sys.version)[0]
237 version_ints = map(int, string.split(version_string, '.'))
238 sys.version_info = tuple(version_ints + ['final', 0])
243 # Pre-1.6 Python has no UserString module.
244 import_as('_scons_UserString', 'UserString')