https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90536
--- Comment #12 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Mon, May 20, 2019 at 03:06:32PM +0000, sgk at troutmask dot apl.washington.edu wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90536 > > --- Comment #11 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- > On Mon, May 20, 2019 at 07:32:09AM +0000, tkoenig at gcc dot gnu.org wrote: > > > > what I meant is that > > > > Program main > > Integer(kind=1) :: n > > n = 1 > > End > > > > should not warn with -fno-range-check -Wall, and it does. > > > > The warning technically is correct. It is a warning about the > type conversion not about the value. > Upon further reflection, not only is gfortran's behavior correct, it is desireable. This PR should be closed as INVALID. Why? For the above code, neither gfortran -c -Wconversion a.f90 nor gfortran -c -Wconversion-extra a.f90 emit a warning because gfortran does range checking, determines that the INTEGER(4) '1' on the RHS is within range of an INTEGER(1) 'n' on the LHS when type conversion is done, and so chooses to suppress a conversion warning. When a user uses -fno-range-check, she/he is specifically asking the compiler to not range check. gfortran only knows that the RHS is an INTEGER(1) entity and the LHS is an INTEGER(4) entity. It has no other information upon which to make a decision of whether to emit a warning. So, gfortran informs the user that a conversion occurs. There is no other information without range checking.
