[ python-Bugs-1501934 ] incorrect LOAD/STORE_GLOBAL generation

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Bugs item #1501934, was opened at 2006-06-07 01:57
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Category: Parser/Compiler
Group: Python 2.5
Status: Open
Resolution: None
Priority: 6
Submitted By: Thomas Wouters (twouters)
Assigned to: Neal Norwitz (nnorwitz)
Summary: incorrect LOAD/STORE_GLOBAL generation

Initial Comment:
Python 2.5 compiles the following piece of code
differently than Python 2.4:

g = 1
def f():
    g += 1

In Python 2.4, this raises an UnboundLocalError. In
current svn trunk, it will increment the global g by 1.
(dis.dis shows that it actually compiles into
LOAD/STORE_GLOBAL opcodes.) It seems the compiler
doesn't treat augmented assignment as assignment for
the purpose of determining locals, as this still fails
correctly:

g = 1
def f():
    g += 1
    g = 5

I can't find where this optimization happens nowadays,
but it feels like a short fix.


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