[Bug fortran/100656] New: ICE in gfc_conv_expr_present, at fortran/trans-expr.c:1934

["gscfq@t-online.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100656

            Bug ID: 100656
           Summary: ICE in gfc_conv_expr_present, at
                    fortran/trans-expr.c:1934
           Product: gcc
           Version: 12.0
            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 r5 :
(with option -fcheck=all or -fcheck=bounds)


$ cat z1.f90
subroutine s(x)
   character(:), allocatable, optional :: x(:)
   if ( present(x) ) then
      if ( allocated(x) ) then
         x = 'a' // x // 'e'
      end if
   end if
end


$ gfortran-12-20210516 -c z1.f90 -fcheck=all
z1.f90:5:28:

    5 |          x = 'a' // x // 'e'
      |                            1
internal compiler error: in gfc_conv_expr_present, at fortran/trans-expr.c:1934
0x767b80 gfc_conv_expr_present(gfc_symbol*, bool)
        ../../gcc/fortran/trans-expr.c:1934
0x745114 gfc_conv_ss_startstride(gfc_loopinfo*)
        ../../gcc/fortran/trans-array.c:4723
0x77b991 gfc_trans_assignment_1
        ../../gcc/fortran/trans-expr.c:11218
0x73dcb7 trans_code
        ../../gcc/fortran/trans.c:1932
0x7aa2f5 gfc_trans_if_1
        ../../gcc/fortran/trans-stmt.c:1475
0x7b1e8a gfc_trans_if(gfc_code*)
        ../../gcc/fortran/trans-stmt.c:1507
0x73ddd7 trans_code
        ../../gcc/fortran/trans.c:2020
0x7aa2f5 gfc_trans_if_1
        ../../gcc/fortran/trans-stmt.c:1475
0x7b1e8a gfc_trans_if(gfc_code*)
        ../../gcc/fortran/trans-stmt.c:1507
0x73ddd7 trans_code
        ../../gcc/fortran/trans.c:2020
0x764314 gfc_generate_function_code(gfc_namespace*)
        ../../gcc/fortran/trans-decl.c:6885
0x6eac86 translate_all_program_units
        ../../gcc/fortran/parse.c:6370
0x6eac86 gfc_parse_file()
        ../../gcc/fortran/parse.c:6639
0x736f7f gfc_be_parse_file
        ../../gcc/fortran/f95-lang.c:212