mirror of https://github.com/python/cpython
83 lines
2.5 KiB
Python
83 lines
2.5 KiB
Python
"""Fixer for 'raise E, V, T'
|
|
|
|
raise -> raise
|
|
raise E -> raise E
|
|
raise E, V -> raise E(V)
|
|
raise E, V, T -> raise E(V).with_traceback(T)
|
|
|
|
raise (((E, E'), E''), E'''), V -> raise E(V)
|
|
raise "foo", V, T -> warns about string exceptions
|
|
|
|
|
|
CAVEATS:
|
|
1) "raise E, V" will be incorrectly translated if V is an exception
|
|
instance. The correct Python 3 idiom is
|
|
|
|
raise E from V
|
|
|
|
but since we can't detect instance-hood by syntax alone and since
|
|
any client code would have to be changed as well, we don't automate
|
|
this.
|
|
"""
|
|
# Author: Collin Winter
|
|
|
|
# Local imports
|
|
from .. import pytree
|
|
from ..pgen2 import token
|
|
from .. import fixer_base
|
|
from ..fixer_util import Name, Call, Attr, ArgList, is_tuple
|
|
|
|
class FixRaise(fixer_base.BaseFix):
|
|
|
|
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 is token.STRING:
|
|
self.cannot_convert(node, "Python 3 does not support string exceptions")
|
|
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 = " "
|
|
|
|
if "val" not in results:
|
|
# One-argument raise
|
|
new = pytree.Node(syms.raise_stmt, [Name(u"raise"), exc])
|
|
new.prefix = node.prefix
|
|
return new
|
|
|
|
val = results["val"].clone()
|
|
if is_tuple(val):
|
|
args = [c.clone() for c in val.children[1:-1]]
|
|
else:
|
|
val.prefix = u""
|
|
args = [val]
|
|
|
|
if "tb" in results:
|
|
tb = results["tb"].clone()
|
|
tb.prefix = u""
|
|
|
|
e = Call(exc, args)
|
|
with_tb = Attr(e, Name(u'with_traceback')) + [ArgList([tb])]
|
|
new = pytree.Node(syms.simple_stmt, [Name(u"raise")] + with_tb)
|
|
new.prefix = node.prefix
|
|
return new
|
|
else:
|
|
return pytree.Node(syms.raise_stmt,
|
|
[Name(u"raise"), Call(exc, args)],
|
|
prefix=node.prefix)
|