[Bug fortran/77643] New: ICE with "character(len=:), pointer :: p => null()"

[mrestelli at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77643

            Bug ID: 77643
           Summary: ICE with "character(len=:), pointer :: p => null()"
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mrestelli at gmail dot com
  Target Milestone: ---

The attached code produces an internal compiler error. It seems that,
in order to trigger the error, both  LEN=:  and  =>NULL()  are
necessary.


module m
 implicit none
 character(len=:), pointer :: r           ! works
 character(len=5), pointer :: s => null() ! works
 character(len=:), pointer :: p => null() ! ICE
end module m



$ gfortran --version
GNU Fortran (GCC) 7.0.0 20160919 (experimental)


$ gfortran -c m.f90 
f951: internal compiler error: in gfc_get_symbol_decl, bei
fortran/trans-decl.c:1695
0x6b1022 gfc_get_symbol_decl(gfc_symbol*)
        gcc/fortran/trans-decl.c:1695
0x6b2e18 gfc_create_module_variable
        gcc/fortran/trans-decl.c:4727
0x67b75b do_traverse_symtree
        gcc/fortran/symbol.c:3939
0x6b57bb gfc_generate_module_vars(gfc_namespace*)
        gcc/fortran/trans-decl.c:5170
0x694319 gfc_generate_module_code(gfc_namespace*)
        gcc/fortran/trans.c:2030
0x64bfcb translate_all_program_units
        gcc/fortran/parse.c:5923
0x64bfcb gfc_parse_file()
        gcc/fortran/parse.c:6142
0x68d7c2 gfc_be_parse_file
        gcc/fortran/f95-lang.c:198