py/compile: Disallow 'import *' outside module level.

This check follows CPython's behaviour, because 'import *' always populates
the globals with the imported names, not locals.

Since it's safe to do this (doesn't lead to a crash or undefined behaviour)
the check is only enabled for MICROPY_CPYTHON_COMPAT.

Fixes issue #5121.

1 files changed, 13 insertions, 0 deletions

diff --git a/tests/import/import_star_error.py b/tests/import/import_star_error.py
new file mode 100644
index 000000000..17e237b8c
--- /dev/null
+++ b/tests/import/import_star_error.py
@@ -0,0 +1,13 @@
+# test errors with import *
+
+# 'import *' is not allowed in function scope
+try:
+    exec('def foo(): from x import *')
+except SyntaxError as er:
+    print('function', 'SyntaxError')
+
+# 'import *' is not allowed in class scope
+try:
+    exec('class C: from x import *')
+except SyntaxError as er:
+    print('class', 'SyntaxError')