[Bug fortran/89185] New: [9 Regression] runtime error: member access within null pointer of type 'struct gfc_ref' since r268092

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89185

            Bug ID: 89185
           Summary: [9 Regression] runtime error: member access within
                    null pointer of type 'struct gfc_ref' since r268092
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: tkoenig at gcc dot gnu.org
  Target Milestone: ---

Following small test-case shows the problem:

$ cat a.f90
  character(20)  a(2)  
  call b(a(:)(:20))
end

$ ./xgcc -B. a.f90 -c
../../gcc/fortran/resolve.c:5059:60: runtime error: member access within null
pointer of type 'struct gfc_ref'
    #0 0xb21c04 in resolve_ref ../../gcc/fortran/resolve.c:5059
    #1 0xb27733 in resolve_variable ../../gcc/fortran/resolve.c:5540
    #2 0xb3486a in gfc_resolve_expr(gfc_expr*) ../../gcc/fortran/resolve.c:6856
    #3 0xb02fd5 in resolve_actual_arglist ../../gcc/fortran/resolve.c:1916
    #4 0xb13466 in resolve_call ../../gcc/fortran/resolve.c:3638
    #5 0xb68654 in gfc_resolve_code(gfc_code*, gfc_namespace*)
../../gcc/fortran/resolve.c:11495
    #6 0xba15d8 in resolve_codes ../../gcc/fortran/resolve.c:16737
    #7 0xba17df in gfc_resolve(gfc_namespace*)
../../gcc/fortran/resolve.c:16772
    #8 0xad4ae4 in resolve_all_program_units ../../gcc/fortran/parse.c:6073
    #9 0xad5dd6 in gfc_parse_file() ../../gcc/fortran/parse.c:6323
    #10 0xc3b836 in gfc_be_parse_file ../../gcc/fortran/f95-lang.c:204
    #11 0x230b1de in compile_file ../../gcc/toplev.c:456
    #12 0x23126d9 in do_compile ../../gcc/toplev.c:2176
    #13 0x2312d07 in toplev::main(int, char**) ../../gcc/toplev.c:2311
    #14 0x469402e in main ../../gcc/main.c:39
    #15 0x7ffff608cfea in __libc_start_main ../csu/libc-start.c:308
    #16 0x875bd9 in _start
(/home/marxin/Programming/gcc2/objdir/gcc/f951+0x875bd9)