Mercurial > cpython-lru_cache-weakref

annotate Lib/compiler/future.py @ 25838:8540887bcec6 2.2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Backport of 2.183: Fix memory leak in add_subclass() found by NealN with valgrind.
author Guido van Rossum <guido@python.org>
date Fri, 18 Oct 2002 13:42:21 +0000
parents a12ccdbce8da
children acaa79e73133
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
17346
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
1 """Parser for future statements
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
2
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
3 """
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
4
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
5 from compiler import ast, walk
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
6
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
7 def is_future(stmt):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
8 """Return true if statement is a well-formed future statement"""
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
9 if not isinstance(stmt, ast.From):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
10 return 0
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
11 if stmt.modname == "__future__":
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
12 return 1
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
13 else:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
14 return 0
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
15
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
16 class FutureParser:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
17
19361
9222b6e3b368 Track removal of doc string from Module().nodes[0]
Jeremy Hylton <jeremy@alum.mit.edu>
parents: 17346
diff changeset
18 features = ("nested_scopes", "generators", "division")
20547
a12ccdbce8da Whitespace normalization.
Tim Peters <tim.peters@gmail.com>
parents: 19361
diff changeset
19
17346
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
20 def __init__(self):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
21 self.found = {} # set
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
22
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
23 def visitModule(self, node):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
24 stmt = node.node
19361
9222b6e3b368 Track removal of doc string from Module().nodes[0]
Jeremy Hylton <jeremy@alum.mit.edu>
parents: 17346
diff changeset
25 for s in stmt.nodes:
17346
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
26 if not self.check_stmt(s):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
27 break
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
28
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
29 def check_stmt(self, stmt):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
30 if is_future(stmt):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
31 for name, asname in stmt.names:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
32 if name in self.features:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
33 self.found[name] = 1
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
34 else:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
35 raise SyntaxError, \
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
36 "future feature %s is not defined" % name
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
37 stmt.valid_future = 1
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
38 return 1
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
39 return 0
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
40
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
41 def get_features(self):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
42 """Return list of features enabled by future statements"""
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
43 return self.found.keys()
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
44
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
45 class BadFutureParser:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
46 """Check for invalid future statements"""
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
47
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
48 def visitFrom(self, node):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
49 if hasattr(node, 'valid_future'):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
50 return
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
51 if node.modname != "__future__":
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
52 return
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
53 raise SyntaxError, "invalid future statement"
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
54
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
55 def find_futures(node):
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
56 p1 = FutureParser()
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
57 p2 = BadFutureParser()
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
58 walk(node, p1)
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
59 walk(node, p2)
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
60 return p1.get_features()
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
61
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
62 if __name__ == "__main__":
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
63 import sys
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
64 from compiler import parseFile, walk
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
65
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
66 for file in sys.argv[1:]:
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
67 print file
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
68 tree = parseFile(file)
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
69 v = FutureParser()
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
70 walk(tree, v)
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
71 print v.found
f8fdbeb73667 Add support for future statements
Jeremy Hylton <jeremy@alum.mit.edu>
parents:
diff changeset
72 print