[Bug fortran/26801] -fbounds-check generates segfault

[fxcoudert at gcc dot gnu dot org]

------- Comment #3 from fxcoudert at gcc dot gnu dot org  2006-05-28 13:23 -------
I tried with the following reduced testcase:

  implicit none

  integer :: i
  logical :: l
  type dt
    integer, pointer :: a => null()
  end type dt
  type(dt), pointer :: obj(:) => null()


  allocate(obj(2))
  i = 1
  l = associated(obj(i)%a)
  print *, l
end


The code generated for the ASSOCIATED statement is the following when
bounds-checking is disabled:
  i = 1;
  l = (*(struct dt[0:] *) obj.data)[obj.dim[0].stride * i + obj.offset].a !=
0B;

When bounds-checking is enabled, it is changed into:
  i = 1;
  {
    int4 D.924;

    l = (*(struct dt[0:] *) obj.data)[obj.dim[0].stride * D.924 + obj.offset].a
!= 0B;
  }

Notice that D.924 is used uninitialized. The -fbounds-check options gives a
special codepath in three occasions:

0x080ad083 in gfc_conv_ss_startstride (loop=0xbfa1813c)
    at ../../../trunk/gcc/fortran/trans-array.c:2456
2456      if (flag_bounds_check)
(gdb) c
Continuing.
Hardware read watchpoint 1: flag_bounds_check

Value = 1
0x080acc2c in gfc_conv_array_ref (se=0xbfa17ab4, ar=0x87222bc)
    at ../../../trunk/gcc/fortran/trans-array.c:1951
1951          if (flag_bounds_check && ar->as->type != AS_ASSUMED_SIZE)
(gdb) 
Continuing.
Hardware read watchpoint 1: flag_bounds_check

Value = 1
0x080acd5c in gfc_conv_array_ref (se=0xbfa17ab4, ar=0x87222bc)
    at ../../../trunk/gcc/fortran/trans-array.c:1980
1980      if (flag_bounds_check)


I don't understand where this D.924 variable is generated.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org
   Last reconfirmed|2006-03-22 21:22:10         |2006-05-28 13:23:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26801