108 lines
3.8 KiB
Python
108 lines
3.8 KiB
Python
|
"""Fixer for 'raise E, V'
|
||
|
|
|
||
|
|
From Armin Ronacher's ``python-modernize``.
|
||
|
|
|
||
|
|
raise -> raise
|
||
|
|
raise E -> raise E
|
||
|
|
raise E, 5 -> raise E(5)
|
||
|
|
raise E, 5, T -> raise E(5).with_traceback(T)
|
||
|
|
raise E, None, T -> raise E.with_traceback(T)
|
||
|
|
|
||
|
|
raise (((E, E'), E''), E'''), 5 -> raise E(5)
|
||
|
|
raise "foo", V, T -> warns about string exceptions
|
||
|
|
|
||
|
|
raise E, (V1, V2) -> raise E(V1, V2)
|
||
|
|
raise E, (V1, V2), T -> raise E(V1, V2).with_traceback(T)
|
||
|
|
|
||
|
|
|
||
|
|
CAVEATS:
|
||
|
|
1) "raise E, V, T" cannot be translated safely in general. If V
|
||
|
|
is not a tuple or a (number, string, None) literal, then:
|
||
|
|
|
||
|
|
raise E, V, T -> from future.utils import raise_
|
||
|
|
raise_(E, V, T)
|
||
|
|
"""
|
||
|
|
# Author: Collin Winter, Armin Ronacher, Mark Huang
|
||
|
|
|
||
|
|
# Local imports
|
||
|
|
from lib2to3 import pytree, fixer_base
|
||
|
|
from lib2to3.pgen2 import token
|
||
|
|
from lib2to3.fixer_util import Name, Call, is_tuple, Comma, Attr, ArgList
|
||
|
|
|
||
|
|
from libfuturize.fixer_util import touch_import_top
|
||
|
|
|
||
|
|
|
||
|
|
class FixRaise(fixer_base.BaseFix):
|
||
|
|
|
||
|
|
BM_compatible = True
|
||
|
|
PATTERN = """
|
||
|
|
raise_stmt< 'raise' exc=any [',' val=any [',' tb=any]] >
|
||
|
|
"""
|
||
|
|
|
||
|
|
def transform(self, node, results):
|
||
|
|
syms = self.syms
|
||
|
|
|
||
|
|
exc = results["exc"].clone()
|
||
|
|
if exc.type == token.STRING:
|
||
|
|
msg = "Python 3 does not support string exceptions"
|
||
|
|
self.cannot_convert(node, msg)
|
||
|
|
return
|
||
|
|
|
||
|
|
# Python 2 supports
|
||
|
|
# raise ((((E1, E2), E3), E4), E5), V
|
||
|
|
# as a synonym for
|
||
|
|
# raise E1, V
|
||
|
|
# Since Python 3 will not support this, we recurse down any tuple
|
||
|
|
# literals, always taking the first element.
|
||
|
|
if is_tuple(exc):
|
||
|
|
while is_tuple(exc):
|
||
|
|
# exc.children[1:-1] is the unparenthesized tuple
|
||
|
|
# exc.children[1].children[0] is the first element of the tuple
|
||
|
|
exc = exc.children[1].children[0].clone()
|
||
|
|
exc.prefix = u" "
|
||
|
|
|
||
|
|
if "tb" in results:
|
||
|
|
tb = results["tb"].clone()
|
||
|
|
else:
|
||
|
|
tb = None
|
||
|
|
|
||
|
|
if "val" in results:
|
||
|
|
val = results["val"].clone()
|
||
|
|
if is_tuple(val):
|
||
|
|
# Assume that exc is a subclass of Exception and call exc(*val).
|
||
|
|
args = [c.clone() for c in val.children[1:-1]]
|
||
|
|
exc = Call(exc, args)
|
||
|
|
elif val.type in (token.NUMBER, token.STRING):
|
||
|
|
# Handle numeric and string literals specially, e.g.
|
||
|
|
# "raise Exception, 5" -> "raise Exception(5)".
|
||
|
|
val.prefix = u""
|
||
|
|
exc = Call(exc, [val])
|
||
|
|
elif val.type == token.NAME and val.value == u"None":
|
||
|
|
# Handle None specially, e.g.
|
||
|
|
# "raise Exception, None" -> "raise Exception".
|
||
|
|
pass
|
||
|
|
else:
|
||
|
|
# val is some other expression. If val evaluates to an instance
|
||
|
|
# of exc, it should just be raised. If val evaluates to None,
|
||
|
|
# a default instance of exc should be raised (as above). If val
|
||
|
|
# evaluates to a tuple, exc(*val) should be called (as
|
||
|
|
# above). Otherwise, exc(val) should be called. We can only
|
||
|
|
# tell what to do at runtime, so defer to future.utils.raise_(),
|
||
|
|
# which handles all of these cases.
|
||
|
|
touch_import_top(u"future.utils", u"raise_", node)
|
||
|
|
exc.prefix = u""
|
||
|
|
args = [exc, Comma(), val]
|
||
|
|
if tb is not None:
|
||
|
|
args += [Comma(), tb]
|
||
|
|
return Call(Name(u"raise_"), args)
|
||
|
|
|
||
|
|
if tb is not None:
|
||
|
|
tb.prefix = ""
|
||
|
|
exc_list = Attr(exc, Name('with_traceback')) + [ArgList([tb])]
|
||
|
|
else:
|
||
|
|
exc_list = [exc]
|
||
|
|
|
||
|
|
return pytree.Node(syms.raise_stmt,
|
||
|
|
[Name(u"raise")] + exc_list,
|
||
|
|
prefix=node.prefix)
|