[Bug fortran/58100] Spurious "DO loop at (1) will be executed zero times" warning

["roland.kaufmann at uni dot no" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58100

--- Comment #5 from Roland Kaufmann <roland.kaufmann at uni dot no> ---
(In reply to Tobias Burnus from comment #3)
> Roland: Is the new warning option -W(no-)zerotrip sufficient for you?

As a general principle: I believe that the compiler should not issue any
warnings if run without options on correct code.

If you are compiling code you didn't write yourself, on a new architecture,
then every warning should be a flag for further checking. Having spurious
warnings erodes this and increases the likelihood of real problems being
"drowned", because no-one pays attention anymore.

That said, I perfectly understand the problem of separating the various
compiler stages and Fortran is not the easiest language to do static analysis
for either.

It seems from r201658 of resolve.c it will not surface with no option anymore,
surface with -Wall and disappear again with -Wall -Wno-zerotrip, so that'll
have to be good enough.