# 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):

    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].set_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.get_prefix())