https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100440
--- Comment #12 from anlauf at gcc dot gnu.org ---
A small variation of the testcase in comment#9 suggests that there are
actually two underlying issues: lack of initialization and a missing
temporary.
program p
implicit none
type fm
real, allocatable :: mp(:)
integer :: dummy = 42
end type
type(fm), allocatable :: a(:), b(:)
integer :: n = 1
allocate (a(n))
print *, "main:", n, allocated (a(n)% mp), a(n)% dummy
b = mm (a)
a = mm (b)
a = mm (a)
a = mm (a) ! crashes here with -fsanitize=address
contains
function mm (ma)
type(fm), intent(in) :: ma(:)
type(fm) :: mm(size(ma))
integer :: i
! type(fm) :: z(size(ma))
! mm = z ! Explicit initialization of function result
do i = 1, size(ma)
print *, "in mm:", i, allocated (mm(i)% mp), mm(i)% dummy
end do
end function mm
end program p
This gives:
main: 1 F 42
in mm: 1 F 0
in mm: 1 F 42
in mm: 1 F 0
in mm: 1 T 0
while with -fsanitize=address,undefined :
main: 1 F 42
in mm: 1 F -1094795586
in mm: 1 F 42
in mm: 1 T -1094795586
in mm: 1 T -1094795586
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
Backtrace for this error:
#0 0x14987da6f49f in ???
[...]
#6 0x409669 in p
at /home/anlauf/gcc-bugs/pr100440-red3.f90:14
#7 0x4097d9 in main
at /home/anlauf/gcc-bugs/pr100440-red3.f90:14
