https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66775
Bug ID: 66775
Summary: Allocatable function result type(t) produces segfault
when uninitialized
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: vehre at gcc dot gnu.org
Target Milestone: ---
Created attachment 35917
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35917&action=edit
Full pseudo code of failing example.
The following code produces a segfault:
! { dg-do run }
module test_alloc_func_mod
implicit none
type t
integer :: i = 5
end type
contains
type(t) function t_init() ! { dg-warning "not set" }
allocatable :: t_init
end function
end module test_alloc_func_mod
program test_alloc_func
use test_alloc_func_mod
type(t), allocatable :: temp
temp = t_init() ! <-- This derefs a null-pointer currently
if (allocated (temp)) call abort()
end program
The pseudo code in question is:
t_init ()
{
struct t * __result_t_init;
__result_t_init = 0B; // Setting NULL-pointer.
return __result_t_init;
}
for t_init, and reduced to the essential line (full pseudo code is attached)
struct t * temp;
struct t * D.3388;
temp = (struct t *) __builtin_malloc (4);
D.3388 = t_init ();
*temp = *D.3388; // D.3388 is NULL; dereferencing it here is hazardous.
This error was experienced during patching of pr58586.
