py/compile: Refine SyntaxError for repeated use of global/nonlocal.

2 files changed, 31 insertions, 2 deletions

diff --git a/tests/basics/scope.py b/tests/basics/scope.py
new file mode 100644
index 000000000..3aecc0b8d
--- /dev/null
+++ b/tests/basics/scope.py
@@ -0,0 +1,21 @@
+# test scoping rules
+
+# explicit global variable
+a = 1
+def f():
+    global a
+    global a, a # should be able to redefine as global
+    a = 2
+f()
+print(a)
+
+# explicit nonlocal variable
+def f():
+    a = 1
+    def g():
+        nonlocal a
+        nonlocal a, a # should be able to redefine as nonlocal
+        a = 2
+    g()
+    return a
+print(f())
diff --git a/tests/basics/syntaxerror.py b/tests/basics/syntaxerror.py
index f7ccabcbb..d6a3e3043 100644
--- a/tests/basics/syntaxerror.py
+++ b/tests/basics/syntaxerror.py
@@ -77,8 +77,7 @@ test_syntax("return")
 test_syntax("yield")
 test_syntax("nonlocal a")
 
-# errors on uPy but shouldn't
-#test_syntax("global a; global a")
+# error on uPy, warning on CPy
 #test_syntax("def f():\n a = 1\n global a")
 
 # default except must be last
@@ -109,3 +108,12 @@ test_syntax("def f(a, a): pass")
 
 # nonlocal must exist in outer function/class scope
 test_syntax("def f():\n def g():\n  nonlocal a")
+
+# param can't be redefined as global
+test_syntax('def f(x):\n global x')
+
+# param can't be redefined as nonlocal
+test_syntax('def f(x):\n nonlocal x')
+
+# can define variable to be both nonlocal and global
+test_syntax('def f():\n nonlocal x\n global x')