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Re: Designs for better debug info in GCC
On Thu, 8 Nov 2007, Robert Dewar wrote:
> significantly degraded -O1 debugging. I have found for
> instance that debugging the GNAT compiler itself, -O1
> used to be perfectly fine, but now far too many arguments
> and variables disappear.
Yes. That problem is addressed by Alexandre's approach and by ours. If
you want to be really sure no arguments disappear (necessary for instance
for meaningful use of systemtap) you also need to inhibit some
transformations, which can be done under a certain option (which might or
might not be on by default for -O1).
> 3. The quality of code at -O0 is really terrible compared
> to the competition (at least in the case of Ada), and
> large scale programs are just too big at -O0 to be
> practical (there is a big difference between a 50
> megabyte image and a 100 megabyte image).
This is a problem on it's own. We're planning to work on this somewhen
during the next months, i.e. improve code quality at -O0 at least to a
point it was in the 3.x line of GCC.