[Bug middle-end/36296] bogus uninitialized warning (loop representation, VRP missed-optimization)

[vincent-gcc at vinc17 dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36296

--- Comment #20 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> 2013-04-17 11:17:14 UTC ---
(In reply to comment #18)
> In fact, we should have removed the i=i idiom a long time ago. The correct
> thing to do (as Linus says) is to initialize the variable to a sensible value
> to silence the warning: http://lwn.net/Articles/529954/

There is no real sensible value except some trap value. Letting the variable
uninitialized at that point (the declaration) allows some tools, like the
Formalin compiler described in WG14/N1637, to detect potential problems if the
variable is really used uninitialized.

(In reply to comment #19)
> Note that -Wmaybe-uninitialized is available since at least GCC 4.8.0

OK, so a solution would be to add a configure test for projects that don't want
such warnings (while still using -Wall) to see whether -Wno-maybe-uninitialized
is supported.