[Bug fortran/77900] New: Compile time errors/warning for IO statements appear wrong

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77900

            Bug ID: 77900
           Summary: Compile time errors/warning for IO statements appear
                    wrong
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jvdelisle at gcc dot gnu.org
  Target Milestone: ---

While looking at something else I stumbled on this with iomesg_1.f90.

$ gfc -std=gnu iomsg_1.f90 
iomsg_1.f90:25:121:

 sg=ch) ! { dg-warning "STATUS specifier in CLOSE statement.*has invalid value"
}
                                                                               
1
Warning: STATUS specifier in CLOSE statement at (1) has invalid value ‘no_idea’

I think the above should be a compile error no matter what.

The line in questions is:

  close(23,status="no_idea", err=500, iomsg=ch) ! { dg-warning "STATUS
specifier in CLOSE statement.*has invalid value" }

It gives the expected error when changed to:

  close(23,status="no_idea") ! { dg-warning "STATUS specifier in CLOSE
statement.*has invalid value" }

Compile time errors vs warning should have nothing to do with the absence or
presence of err= or iomsg=

The wrong logic is in fortran/io.c. Probably other statements involved here.