[Bug fortran/91960] New: ICE: backend decl for module variable 'j' already exists

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91960

            Bug ID: 91960
           Summary: ICE: backend decl for module variable 'j' already
                    exists
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Affects versions down to at least gfortran-5,
with undefined variable j :


$ cat z1.f90
module m
   integer :: i, j
   integer, parameter :: a(3) = [1, 2, 3]
   integer, parameter :: b(3) = [(a(j), i=1,3)]
end


$ gfortran-10-20190929 -c z1.f90
f951: internal compiler error: backend decl for module variable 'j' already
exists
0x621b49 gfc_report_diagnostic
        ../../gcc/fortran/error.c:776
0x62323a gfc_internal_error(char const*, ...)
        ../../gcc/fortran/error.c:1391
0x6f48f5 gfc_create_module_variable
        ../../gcc/fortran/trans-decl.c:5231
0x6b3f22 do_traverse_symtree
        ../../gcc/fortran/symbol.c:4165
0x6f4e8b gfc_generate_module_vars(gfc_namespace*)
        ../../gcc/fortran/trans-decl.c:5749
0x6cfc4c gfc_generate_module_code(gfc_namespace*)
        ../../gcc/fortran/trans.c:2224
0x67e641 translate_all_program_units
        ../../gcc/fortran/parse.c:6241
0x67e641 gfc_parse_file()
        ../../gcc/fortran/parse.c:6493
0x6c89af gfc_be_parse_file
        ../../gcc/fortran/f95-lang.c:204