check for assignment to __debug__ during AST generation
Also, give assignment to None a better error message
diff --git a/Python/ast.c b/Python/ast.c
index 29b0e82..6eb3aa4 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -130,7 +130,9 @@
forbidden_check(struct compiling *c, const node *n, const char *x)
{
if (!strcmp(x, "None"))
- return ast_error(n, "assignment to None");
+ return ast_error(n, "cannot assign to None");
+ if (!strcmp(x, "__debug__"))
+ return ast_error(n, "cannot assign to __debug__");
if (Py_Py3kWarningFlag) {
if (!(strcmp(x, "True") && strcmp(x, "False")) &&
!ast_warn(c, n, "assignment to True or False is forbidden in 3.x"))