[Bug c++/71885] Incorrect code generated with -01, memset() function call is missing

[kern at sibbald dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71885

Kern Sibbald <kern at sibbald dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |kern at sibbald dot com

--- Comment #5 from Kern Sibbald <kern at sibbald dot com> ---
I would like to see a precise explanation of what "undefined behavior" is. 
Bacula does zero memory that is passed as a replacement to a new.  This
behavior is desirable and very well defined. I may be wrong, but it seems that
you are assuming that the memory is already zero, which is not a good
assumption. In the case of Bacula memory that is allocated from the heap is
non-zero by explicit programming.  Consequently this seems to me to be an
overly aggressive optimization that should be enabled at a much higher
optimization level than -O2, generally used by Bacula and many other programs.

At some point g++'s tinkering with valid user's programs should stop.  Yes, we
can probably work around the g++ generated bug by explicitly testing for the
g++ compiler version and adding another command line option, but this should be
unnecessary.

Changing g++ in this manner (rather cavalier in my opinion) can create lots of
unnecessary problems for many programs. As you might image, I call this new g++
feature "unreasonable" and "dangerous".  Please remove it or at least make it a
new option that the g++ user must explicitly add.