def visitAugAssign(self, node, walker):
"""Makes a note that augmented assignment is in use.
Note that although augmented assignment of attributes and
subscripts is disallowed, augmented assignment of names (such
as 'n += 1') is allowed.
This could be a problem if untrusted code got access to a
mutable database object that supports augmented assignment.
"""
if node.node.__class__.__name__ == 'Name':
node = walker.defaultVisitNode(node)
newnode = ast.Assign(
[ast.AssName(node.node.name, OP_ASSIGN)],
ast.CallFunc(_inplacevar_name, [
ast.Const(node.op),
ast.Name(node.node.name),
node.expr,
]),
)
newnode.lineno = node.lineno
return newnode
else:
node.node.in_aug_assign = True
return walker.defaultVisitNode(node)
for child in node.getChildren():
if isinstance(child, ast.Node):
rmLineno(child)
def stmtNode(txt):
"""Make a "clean" statement node."""
node = parse(txt).node.nodes[0]
rmLineno(node)
return node
# The security checks are performed by a set of six functions that
# must be provided by the restricted environment.
_apply_name = ast.Name("_apply_")
_getattr_name = ast.Name("_getattr_")
_getitem_name = ast.Name("_getitem_")
_getiter_name = ast.Name("_getiter_")
_print_target_name = ast.Name("_print")
_write_name = ast.Name("_write_")
_inplacevar_name = ast.Name("_inplacevar_")
# Constants.
_None_const = ast.Const(None)
_write_const = ast.Const("write")
_printed_expr = stmtNode("_print()").expr
_print_target_node = stmtNode("_print = _print_()")