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Re: gcc: optimizations, and stack traces

Le 09/02/2018 à 12:13, Valery Ushakov a écrit :
[Summoning Krister]

On Fri, Feb 09, 2018 at 11:23:17 +0100, Maxime Villard wrote:

There are also several cases where functions in the call tree can disappear
from the backtrace. In the following call tree:

	A -> B -> C -> D   (and D panics)

if, in B, GCC put the two instructions after the instruction that calls C,
the backtrace will be:

	A -> C -> D

This can make a bug completely undebuggable.

Does gcc actually generates code like that?  I thought that it can
delay frame pointer creation, but only until it needs to make a nested
call, to C in your example, (as in the sample I showed in another mail
to this thread).

Mmh, now I'm not so sure about this. Wait a minute, I'll re-give a look and
try to understand what I was doing.


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