py: Make all LOAD_FAST ops check for unbound local.

This is necessary to catch all cases where locals are referenced before
assignment.  We still keep the _0, _1, _2 versions of LOAD_FAST to help
reduced the byte code size in RAM.

Addresses issue #457.

1 files changed, 19 insertions, 0 deletions

diff --git a/tests/basics/unboundlocal.py b/tests/basics/unboundlocal.py
new file mode 100644
index 000000000..5573da166
--- /dev/null
+++ b/tests/basics/unboundlocal.py
@@ -0,0 +1,19 @@
+# locals referenced before assignment
+
+def f1():
+    print(x)
+    x = 1
+
+def f2():
+    for i in range(0):
+        print(i)
+    print(i)
+
+def check(f):
+    try:
+        f()
+    except NameError:
+        print("NameError")
+
+check(f1)
+check(f2)