[Bug fortran/78239] New: ICE in char_len_param_value, at fortran/decl.c:926, with -fimplicit-none

[gerhard.steinmetz.fortran@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78239

            Bug ID: 78239
           Summary: ICE in char_len_param_value, at fortran/decl.c:926,
                    with -fimplicit-none
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerhard.steinmetz.fortran@t-online.de
  Target Milestone: ---

Some valid cases flag an ICE with option -fimplicit-none.
Affects version 5, 6 and 7.


$ cat z1.f90
subroutine s(n)
   character(n) :: c
   c = 'c'
end


$ gfortran-7-20161106 -fimplicit-none z1.f90
f951: internal compiler error: Segmentation fault
0xc3a64f crash_signal
        ../../gcc/toplev.c:338
0x6790df char_len_param_value
        ../../gcc/fortran/decl.c:926
0x67b1a4 gfc_match_char_spec(gfc_typespec*)
        ../../gcc/fortran/decl.c:2847
0x680419 gfc_match_decl_type_spec(gfc_typespec*, int)
        ../../gcc/fortran/decl.c:3055
0x681746 gfc_match_data_decl()
        ../../gcc/fortran/decl.c:4819
0x6d7b89 match_word_omp_simd
        ../../gcc/fortran/parse.c:93
0x6daa9e match_word
        ../../gcc/fortran/parse.c:377
0x6daa9e decode_statement
        ../../gcc/fortran/parse.c:377
0x6dc8a4 next_free
        ../../gcc/fortran/parse.c:1149
0x6dc8a4 next_statement
        ../../gcc/fortran/parse.c:1382
0x6de63c parse_spec
        ../../gcc/fortran/parse.c:3551
0x6e05c3 parse_progunit
        ../../gcc/fortran/parse.c:5521
0x6e1e74 gfc_parse_file()
        ../../gcc/fortran/parse.c:6037
0x725822 gfc_be_parse_file
        ../../gcc/fortran/f95-lang.c:198