[Bug fortran/28399] New: Implement ftnchek-like warnings

["tkoenig at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

There are some useful warnings that gfortran could issue.
Examples:

$ cat chk.f
      program main
      double precision a
      real b
      b = 2.3**(2/3)
      a = 4.3*1d5
      print *,a,b
      b = 1.23456789012345
      print *,4**(-3)
      end
$ ftnchek chk.f

FTNCHEK Version 3.3 November 2004

File chk.f:
      4       b = 2.3**(2/3)
                         ^
Warning near line 4 col 18 file chk.f: integer const expr yields result of 0
                     ^
Warning near line 4 col 14 file chk.f: integer quotient expr (2/3) used in
 exponent
      5       a = 4.3*1d5
                     ^
Warning near line 5 col 14 file chk.f: promotion may not give desired
 precision: real const 4.3 * dble const 1D5
      7       b = 1.23456789012345
                  ^
Warning near line 7 col 11 file chk.f: Single-precision real constant has more
 digits than are stored
      8       print *,4**(-3)
                       ^
Warning near line 8 col 16 file chk.f: integer const expr yields result of 0

 0 syntax errors detected in file chk.f
 5 warnings issued in file chk.f


-- 
           Summary: Implement ftnchek-like warnings
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28399