From f4136c2c8d5c2470640d04074c10b9e576c0e4fb Mon Sep 17 00:00:00 2001
From: Amaury Forgeot d'Arc <amauryfa@gmail.com>
Date: Fri, 10 Sep 2010 21:39:53 +0000
Subject: #4617: Previously it was illegal to delete a name from the local
 namespace if it occurs as a free variable in a nested block.  This limitation
 of the compiler has been lifted, and a new opcode introduced (DELETE_DEREF).

This sample was valid in 2.6, but fails to compile in 3.x without this change::

   >>> def f():
   ...     def print_error():
   ...        print(e)
   ...     try:
   ...        something
   ...     except Exception as e:
   ...        print_error()
   ...        # implicit "del e" here


This sample has always been invalid in Python, and now works::

   >>> def outer(x):
   ...     def inner():
   ...        return x
   ...     inner()
   ...     del x

There is no need to bump the PYC magic number: the new opcode is used
for code that did not compile before.
---
 Python/opcode_targets.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'Python/opcode_targets.h')

diff --git a/Python/opcode_targets.h b/Python/opcode_targets.h
index 8b59c2db78..a91da79be6 100644
--- a/Python/opcode_targets.h
+++ b/Python/opcode_targets.h
@@ -137,7 +137,7 @@ static void *opcode_targets[256] = {
     &&TARGET_LOAD_CLOSURE,
     &&TARGET_LOAD_DEREF,
     &&TARGET_STORE_DEREF,
-    &&_unknown_opcode,
+    &&TARGET_DELETE_DEREF,
     &&_unknown_opcode,
     &&TARGET_CALL_FUNCTION_VAR,
     &&TARGET_CALL_FUNCTION_KW,
-- 
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