[Bug fortran/82018] -Wextra should imply -Wconversion-extra

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82018

--- Comment #7 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
I expect strong negative feedback if -Wextra starts emitting
lots of warnings about code which is not problematic. This
would diminish the usefulness of -Wextra, and people will
simply remove it from their Makefiles.

Another alternative would be to have three flags:

-Wconversion like now
-Wconversion-extra which catches stuff like i=2.0 (without rounding errors),
 to be enabled by -Wextra
-Wconversion-all which also catches stuff which is always harmless, like
 i8=i4, c4=r4 etc.