[Patches] [ python-Patches-1346214 ] Better dead code elimination for the AST compiler

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Patches item #1346214, was opened at 2005-11-02 10:21
Message generated for change (Comment added) made by nnorwitz
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Category: Parser/Compiler
Group: Python 2.5
Status: Open
>Resolution: Accepted
Priority: 5
Submitted By: Rune Holm (titanstar)
>Assigned to: Georg Brandl (gbrandl)
Summary: Better dead code elimination for the AST compiler

Initial Comment:
Here's a patch that adds dead code elimination for if
0: style statements, and improves the current dead code
elimination for while statements by not performing
elimination if the function is a generator.  If the
last yield statement from a generator is removed, the
generator is turned into a regular function, which
changes the semantics of the function.

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>Comment By: Neal Norwitz (nnorwitz)
Date: 2006-06-03 23:07

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It would be nice to make a #define for the error message so
they don't get out of sync.  I wouldn't mind seeing the
variable name spelled out, ste_returns_value or something
like that.

I didn't look closely at the line numbers and verify the
changes were correct.

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Comment By: Brett Cannon (bcannon)
Date: 2006-06-03 16:51

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Replied on python-dev, but for thoroughness, the patch looks
fine from looking at the patch file itself.  Apply the
'return' detection on its own, though, for better tracking
of changes and easier rollback if something does go bad.

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Comment By: Georg Brandl (gbrandl)
Date: 2006-05-26 04:34

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Attaching new patch which does elimination for if 0, if 1
and if __debug__ correctly (visiting else clauses!) and
correctly recognizes functions mixing "return x" and "yield".

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Comment By: Rune Holm (titanstar)
Date: 2005-11-06 12:41

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Sorry, I'm new to the sourceforge patch tracker. The patch should be 
attached now.

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Comment By: Simon Dahlbacka (sdahlbac)
Date: 2005-11-06 11:08

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the actual patch is missing..

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