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Re: [PATCH] Omit frame pointer and fix %ebp by default on x86 (take 3)



On Aug 16, 2004, at 2:51 PM, Andrew Haley wrote:


Roger Sayle writes:

On Mon, 16 Aug 2004, Jakub Jelinek wrote:
Neither do I understand this.

Don't worry about too much. Clearly you're not the only one that's having difficulty grasping these advanced new concepts :>

This patch is not designed to make backtrace work for every frame,
only to stop it from failing.

Well, missing some stack frames is, from the Java point of view, failing. We need stack traces for correct functioning.

We will work around this in Java by using unwinder info to do a
backtrace, but we don't yet do so.  Please do not check in this patch.

When?
It's now been 6 months since the variable tracking stuff necessary to get omit-frame-pointer + debug info going was committed (not to mention that it was on the rtlopt branch for a while before then).
Soon after, a patch to turn on omit-frame-pointer by default was submitted and shot down for the same reason you proffer now.
It would be good to know the timeframe when you plan to have java use unwinder info to do a backtrace, so that people stop submitting this patch (among other obvious reasons).


(I'm really not complaining, i'm just genuinely curious)
Andrew.


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