# Copyright 2006 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.

"""Fixer for exec.

This converts usages of the exec statement into calls to a built-in
exec() function.

exec code in ns1, ns2 -> exec(code, ns1, ns2)
"""

# Local imports
from .. import pytree
from .. import fixer_base
from ..fixer_util import Comma, Name, Call


class FixExec(fixer_base.BaseFix):
BM_compatible = True

PATTERN = """
exec_stmt< 'exec' a=any 'in' b=any [',' c=any] >
|
exec_stmt< 'exec' (not atom<'(' [any] ')'>) a=any >
"""

def transform(self, node, results):
assert results
syms = self.syms
a = results["a"]
b = results.get("b")
c = results.get("c")
args = [a.clone()]
args[0].prefix = ""
if b is not None:
args.extend([Comma(), b.clone()])
if c is not None:
args.extend([Comma(), c.clone()])

return Call(Name("exec"), args, prefix=node.prefix)