| 1 | """Fixer for 'raise E, V, T'
|
|---|
| 2 |
|
|---|
| 3 | raise -> raise
|
|---|
| 4 | raise E -> raise E
|
|---|
| 5 | raise E, V -> raise E(V)
|
|---|
| 6 | raise E, V, T -> raise E(V).with_traceback(T)
|
|---|
| 7 | raise E, None, T -> raise E.with_traceback(T)
|
|---|
| 8 |
|
|---|
| 9 | raise (((E, E'), E''), E'''), V -> raise E(V)
|
|---|
| 10 | raise "foo", V, T -> warns about string exceptions
|
|---|
| 11 |
|
|---|
| 12 |
|
|---|
| 13 | CAVEATS:
|
|---|
| 14 | 1) "raise E, V" will be incorrectly translated if V is an exception
|
|---|
| 15 | instance. The correct Python 3 idiom is
|
|---|
| 16 |
|
|---|
| 17 | raise E from V
|
|---|
| 18 |
|
|---|
| 19 | but since we can't detect instance-hood by syntax alone and since
|
|---|
| 20 | any client code would have to be changed as well, we don't automate
|
|---|
| 21 | this.
|
|---|
| 22 | """
|
|---|
| 23 | # Author: Collin Winter
|
|---|
| 24 |
|
|---|
| 25 | # Local imports
|
|---|
| 26 | from .. import pytree
|
|---|
| 27 | from ..pgen2 import token
|
|---|
| 28 | from .. import fixer_base
|
|---|
| 29 | from ..fixer_util import Name, Call, Attr, ArgList, is_tuple
|
|---|
| 30 |
|
|---|
| 31 | class FixRaise(fixer_base.BaseFix):
|
|---|
| 32 |
|
|---|
| 33 | BM_compatible = True
|
|---|
| 34 | PATTERN = """
|
|---|
| 35 | raise_stmt< 'raise' exc=any [',' val=any [',' tb=any]] >
|
|---|
| 36 | """
|
|---|
| 37 |
|
|---|
| 38 | def transform(self, node, results):
|
|---|
| 39 | syms = self.syms
|
|---|
| 40 |
|
|---|
| 41 | exc = results["exc"].clone()
|
|---|
| 42 | if exc.type == token.STRING:
|
|---|
| 43 | msg = "Python 3 does not support string exceptions"
|
|---|
| 44 | self.cannot_convert(node, msg)
|
|---|
| 45 | return
|
|---|
| 46 |
|
|---|
| 47 | # Python 2 supports
|
|---|
| 48 | # raise ((((E1, E2), E3), E4), E5), V
|
|---|
| 49 | # as a synonym for
|
|---|
| 50 | # raise E1, V
|
|---|
| 51 | # Since Python 3 will not support this, we recurse down any tuple
|
|---|
| 52 | # literals, always taking the first element.
|
|---|
| 53 | if is_tuple(exc):
|
|---|
| 54 | while is_tuple(exc):
|
|---|
| 55 | # exc.children[1:-1] is the unparenthesized tuple
|
|---|
| 56 | # exc.children[1].children[0] is the first element of the tuple
|
|---|
| 57 | exc = exc.children[1].children[0].clone()
|
|---|
| 58 | exc.prefix = u" "
|
|---|
| 59 |
|
|---|
| 60 | if "val" not in results:
|
|---|
| 61 | # One-argument raise
|
|---|
| 62 | new = pytree.Node(syms.raise_stmt, [Name(u"raise"), exc])
|
|---|
| 63 | new.prefix = node.prefix
|
|---|
| 64 | return new
|
|---|
| 65 |
|
|---|
| 66 | val = results["val"].clone()
|
|---|
| 67 | if is_tuple(val):
|
|---|
| 68 | args = [c.clone() for c in val.children[1:-1]]
|
|---|
| 69 | else:
|
|---|
| 70 | val.prefix = u""
|
|---|
| 71 | args = [val]
|
|---|
| 72 |
|
|---|
| 73 | if "tb" in results:
|
|---|
| 74 | tb = results["tb"].clone()
|
|---|
| 75 | tb.prefix = u""
|
|---|
| 76 |
|
|---|
| 77 | e = exc
|
|---|
| 78 | # If there's a traceback and None is passed as the value, then don't
|
|---|
| 79 | # add a call, since the user probably just wants to add a
|
|---|
| 80 | # traceback. See issue #9661.
|
|---|
| 81 | if val.type != token.NAME or val.value != u"None":
|
|---|
| 82 | e = Call(exc, args)
|
|---|
| 83 | with_tb = Attr(e, Name(u'with_traceback')) + [ArgList([tb])]
|
|---|
| 84 | new = pytree.Node(syms.simple_stmt, [Name(u"raise")] + with_tb)
|
|---|
| 85 | new.prefix = node.prefix
|
|---|
| 86 | return new
|
|---|
| 87 | else:
|
|---|
| 88 | return pytree.Node(syms.raise_stmt,
|
|---|
| 89 | [Name(u"raise"), Call(exc, args)],
|
|---|
| 90 | prefix=node.prefix)
|
|---|
