diff options
Diffstat (limited to 'pkg_resources.py')
| -rw-r--r-- | pkg_resources.py | 152 |
1 files changed, 137 insertions, 15 deletions
diff --git a/pkg_resources.py b/pkg_resources.py index 4fae479..efc4475 100644 --- a/pkg_resources.py +++ b/pkg_resources.py @@ -144,7 +144,7 @@ __all__ = [ # Parsing functions and string utilities 'parse_requirements', 'parse_version', 'safe_name', 'safe_version', 'get_platform', 'compatible_platforms', 'yield_lines', 'split_sections', - 'safe_extra', 'to_filename', + 'safe_extra', 'to_filename', 'invalid_marker', 'evaluate_marker', # filesystem utilities 'ensure_directory', 'normalize_path', @@ -1146,6 +1146,129 @@ def to_filename(name): +_marker_names = { + 'os': ['name'], 'sys': ['platform'], + 'platform': ['version','machine','python_implementation'], + 'python_version': [], 'python_full_version': [], 'extra':[], +} + +_marker_values = { + 'os_name': lambda: os.name, + 'sys_platform': lambda: sys.platform, + 'python_full_version': lambda: sys.version.split()[0], + 'python_version': lambda:'%s.%s' % (sys.version_info[0], sys.version_info[1]), + 'platform_version': lambda: _platinfo('version'), + 'platform_machine': lambda: _platinfo('machine'), + 'python_implementation': lambda: _platinfo('python_implementation') or _pyimp(), +} + +def _platinfo(attr): + try: + import platform + except ImportError: + return '' + return getattr(platform, attr, lambda:'')() + +def _pyimp(): + if sys.platform=='cli': + return 'IronPython' + elif sys.platform.startswith('java'): + return 'Jython' + elif '__pypy__' in sys.builtin_module_names: + return 'PyPy' + else: + return 'CPython' + +def invalid_marker(text): + """Validate text as a PEP 426 environment marker; return exception or False""" + try: + evaluate_marker(text) + except SyntaxError: + return sys.exc_info()[1] + return False + +def evaluate_marker(text, extra=None, _ops={}): + """Evaluate a PEP 426 environment marker; SyntaxError if marker is invalid""" + + if not _ops: + + from token import NAME, STRING + import token, symbol, operator + + def and_test(nodelist): + # MUST NOT short-circuit evaluation, or invalid syntax can be skipped! + return reduce(operator.and_, [interpret(nodelist[i]) for i in range(1,len(nodelist),2)]) + + def test(nodelist): + # MUST NOT short-circuit evaluation, or invalid syntax can be skipped! + return reduce(operator.or_, [interpret(nodelist[i]) for i in range(1,len(nodelist),2)]) + + def atom(nodelist): + t = nodelist[1][0] + if t == token.LPAR: + if nodelist[2][0] == token.RPAR: + raise SyntaxError("Empty parentheses") + return interpret(nodelist[2]) + raise SyntaxError("Language feature not supported in environment markers") + + def comparison(nodelist): + if len(nodelist)>4: + raise SyntaxError("Chained comparison not allowed in environment markers") + comp = nodelist[2][1] + cop = comp[1] + if comp[0] == NAME: + if len(nodelist[2]) == 3: + if cop == 'not': + cop = 'not in' + else: + cop = 'is not' + try: + cop = _ops[cop] + except KeyError: + raise SyntaxError(repr(cop)+" operator not allowed in environment markers") + return cop(evaluate(nodelist[1]), evaluate(nodelist[3])) + + _ops.update({ + symbol.test: test, symbol.and_test: and_test, symbol.atom: atom, + symbol.comparison: comparison, 'not in': lambda x,y: x not in y, + 'in': lambda x,y: x in y, '==': operator.eq, '!=': operator.ne, + }) + if hasattr(symbol,'or_test'): + _ops[symbol.or_test] = test + + def interpret(nodelist): + while len(nodelist)==2: nodelist = nodelist[1] + try: + op = _ops[nodelist[0]] + except KeyError: + raise SyntaxError("Comparison or logical expression expected") + raise SyntaxError("Language feature not supported in environment markers: "+symbol.sym_name[nodelist[0]]) + return op(nodelist) + + def evaluate(nodelist): + while len(nodelist)==2: nodelist = nodelist[1] + kind = nodelist[0] + name = nodelist[1] + #while len(name)==2: name = name[1] + if kind==NAME: + try: + op = _marker_values[name] + except KeyError: + raise SyntaxError("Unknown name %r" % name) + return op() + if kind==STRING: + s = nodelist[1] + if s[:1] not in "'\"" or s.startswith('"""') or s.startswith("'''") \ + or '\\' in s: + raise SyntaxError( + "Only plain strings allowed in environment markers") + return s[1:-1] + raise SyntaxError("Language feature not supported in environment markers") + + import parser + return interpret(parser.expr(text).totuple(1)[1]) + + class NullProvider: """Try to implement resources and metadata for arbitrary PEP 302 loaders""" @@ -1843,7 +1966,6 @@ def parse_version(s): parts.pop() parts.append(part) return tuple(parts) - class EntryPoint(object): """Object representing an advertised importable object""" @@ -2057,7 +2179,14 @@ class Distribution(object): dm = self.__dep_map = {None: []} for name in 'requires.txt', 'depends.txt': for extra,reqs in split_sections(self._get_metadata(name)): - if extra: extra = safe_extra(extra) + if extra: + if ':' in extra: + extra, marker = extra.split(':',1) + if invalid_marker(marker): + reqs=[] # XXX warn + elif not evaluate_marker(marker): + reqs=[] + extra = safe_extra(extra) or None dm.setdefault(extra,[]).extend(parse_requirements(reqs)) return dm _dep_map = property(_dep_map) @@ -2081,6 +2210,8 @@ class Distribution(object): for line in self.get_metadata_lines(name): yield line + + def activate(self,path=None): """Ensure distribution is importable on `path` (default=sys.path)""" if path is None: path = sys.path @@ -2119,6 +2250,9 @@ class Distribution(object): raise AttributeError,attr return getattr(self._provider, attr) + + + #@classmethod def from_filename(cls,filename,metadata=None, **kw): return cls.from_location( @@ -2160,18 +2294,6 @@ class Distribution(object): - - - - - - - - - - - - def insert_on(self, path, loc = None): """Insert self.location in path before its nearest parent directory""" |