Python code coverage for Lib/packaging/markers.py

#	count	content
1	n/a	"""Parser for the environment markers micro-language defined in PEP 345."""
2	n/a
3	n/a	import os
4	n/a	import sys
5	n/a	import platform
6	n/a	from io import BytesIO
7	n/a	from tokenize import tokenize, NAME, OP, STRING, ENDMARKER, ENCODING
8	n/a
9	n/a	__all__ = ['interpret']
10	n/a
11	n/a
12	n/a	# allowed operators
13	n/a	_OPERATORS = {'==': lambda x, y: x == y,
14	n/a	'!=': lambda x, y: x != y,
15	n/a	'>': lambda x, y: x > y,
16	n/a	'>=': lambda x, y: x >= y,
17	n/a	'<': lambda x, y: x < y,
18	n/a	'<=': lambda x, y: x <= y,
19	n/a	'in': lambda x, y: x in y,
20	n/a	'not in': lambda x, y: x not in y}
21	n/a
22	n/a
23	n/a	def _operate(operation, x, y):
24	n/a	return _OPERATORS[operation](x, y)
25	n/a
26	n/a
27	n/a	# restricted set of variables
28	n/a	_VARS = {'sys.platform': sys.platform,
29	n/a	'python_version': '%s.%s' % sys.version_info[:2],
30	n/a	# FIXME parsing sys.platform is not reliable, but there is no other
31	n/a	# way to get e.g. 2.7.2+, and the PEP is defined with sys.version
32	n/a	'python_full_version': sys.version.split(' ', 1)[0],
33	n/a	'os.name': os.name,
34	n/a	'platform.version': platform.version(),
35	n/a	'platform.machine': platform.machine(),
36	n/a	'platform.python_implementation': platform.python_implementation(),
37	n/a	}
38	n/a
39	n/a
40	n/a	class _Operation:
41	n/a
42	n/a	def __init__(self, execution_context=None):
43	n/a	self.left = None
44	n/a	self.op = None
45	n/a	self.right = None
46	n/a	if execution_context is None:
47	n/a	execution_context = {}
48	n/a	self.execution_context = execution_context
49	n/a
50	n/a	def _get_var(self, name):
51	n/a	if name in self.execution_context:
52	n/a	return self.execution_context[name]
53	n/a	return _VARS[name]
54	n/a
55	n/a	def __repr__(self):
56	n/a	return '%s %s %s' % (self.left, self.op, self.right)
57	n/a
58	n/a	def _is_string(self, value):
59	n/a	if value is None or len(value) < 2:
60	n/a	return False
61	n/a	for delimiter in '"\'':
62	n/a	if value[0] == value[-1] == delimiter:
63	n/a	return True
64	n/a	return False
65	n/a
66	n/a	def _is_name(self, value):
67	n/a	return value in _VARS
68	n/a
69	n/a	def _convert(self, value):
70	n/a	if value in _VARS:
71	n/a	return self._get_var(value)
72	n/a	return value.strip('"\'')
73	n/a
74	n/a	def _check_name(self, value):
75	n/a	if value not in _VARS:
76	n/a	raise NameError(value)
77	n/a
78	n/a	def _nonsense_op(self):
79	n/a	msg = 'This operation is not supported : "%s"' % self
80	n/a	raise SyntaxError(msg)
81	n/a
82	n/a	def __call__(self):
83	n/a	# make sure we do something useful
84	n/a	if self._is_string(self.left):
85	n/a	if self._is_string(self.right):
86	n/a	self._nonsense_op()
87	n/a	self._check_name(self.right)
88	n/a	else:
89	n/a	if not self._is_string(self.right):
90	n/a	self._nonsense_op()
91	n/a	self._check_name(self.left)
92	n/a
93	n/a	if self.op not in _OPERATORS:
94	n/a	raise TypeError('Operator not supported "%s"' % self.op)
95	n/a
96	n/a	left = self._convert(self.left)
97	n/a	right = self._convert(self.right)
98	n/a	return _operate(self.op, left, right)
99	n/a
100	n/a
101	n/a	class _OR:
102	n/a	def __init__(self, left, right=None):
103	n/a	self.left = left
104	n/a	self.right = right
105	n/a
106	n/a	def filled(self):
107	n/a	return self.right is not None
108	n/a
109	n/a	def __repr__(self):
110	n/a	return 'OR(%r, %r)' % (self.left, self.right)
111	n/a
112	n/a	def __call__(self):
113	n/a	return self.left() or self.right()
114	n/a
115	n/a
116	n/a	class _AND:
117	n/a	def __init__(self, left, right=None):
118	n/a	self.left = left
119	n/a	self.right = right
120	n/a
121	n/a	def filled(self):
122	n/a	return self.right is not None
123	n/a
124	n/a	def __repr__(self):
125	n/a	return 'AND(%r, %r)' % (self.left, self.right)
126	n/a
127	n/a	def __call__(self):
128	n/a	return self.left() and self.right()
129	n/a
130	n/a
131	n/a	def interpret(marker, execution_context=None):
132	n/a	"""Interpret a marker and return a result depending on environment."""
133	n/a	marker = marker.strip().encode()
134	n/a	ops = []
135	n/a	op_starting = True
136	n/a	for token in tokenize(BytesIO(marker).readline):
137	n/a	# Unpack token
138	n/a	toktype, tokval, rowcol, line, logical_line = token
139	n/a	if toktype not in (NAME, OP, STRING, ENDMARKER, ENCODING):
140	n/a	raise SyntaxError('Type not supported "%s"' % tokval)
141	n/a
142	n/a	if op_starting:
143	n/a	op = _Operation(execution_context)
144	n/a	if len(ops) > 0:
145	n/a	last = ops[-1]
146	n/a	if isinstance(last, (_OR, _AND)) and not last.filled():
147	n/a	last.right = op
148	n/a	else:
149	n/a	ops.append(op)
150	n/a	else:
151	n/a	ops.append(op)
152	n/a	op_starting = False
153	n/a	else:
154	n/a	op = ops[-1]
155	n/a
156	n/a	if (toktype == ENDMARKER or
157	n/a	(toktype == NAME and tokval in ('and', 'or'))):
158	n/a	if toktype == NAME and tokval == 'and':
159	n/a	ops.append(_AND(ops.pop()))
160	n/a	elif toktype == NAME and tokval == 'or':
161	n/a	ops.append(_OR(ops.pop()))
162	n/a	op_starting = True
163	n/a	continue
164	n/a
165	n/a	if isinstance(op, (_OR, _AND)) and op.right is not None:
166	n/a	op = op.right
167	n/a
168	n/a	if ((toktype in (NAME, STRING) and tokval not in ('in', 'not'))
169	n/a	or (toktype == OP and tokval == '.')):
170	n/a	if op.op is None:
171	n/a	if op.left is None:
172	n/a	op.left = tokval
173	n/a	else:
174	n/a	op.left += tokval
175	n/a	else:
176	n/a	if op.right is None:
177	n/a	op.right = tokval
178	n/a	else:
179	n/a	op.right += tokval
180	n/a	elif toktype == OP or tokval in ('in', 'not'):
181	n/a	if tokval == 'in' and op.op == 'not':
182	n/a	op.op = 'not in'
183	n/a	else:
184	n/a	op.op = tokval
185	n/a
186	n/a	for op in ops:
187	n/a	if not op():
188	n/a	return False
189	n/a	return True