https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128357
Bug ID: 128357
Summary: Parenthesized variable with allocatable components
leaks
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: jvdelisle at gcc dot gnu.org
Target Milestone: ---
Parenthesized variable with allocatable components leaks as actual argument or
ASSOCIATE selector; scalar CLASS one aliases
When a variable whose type has allocatable components is put in parentheses and
used as an actual argument or as an ASSOCIATE selector, gfortran leaks memory.
A parenthesized scalar CLASS variable is not copied at all: the dummy aliases
the variable.
1) Derived array: the temporary array for (ta) is never freed.
module m
implicit none
type :: t
integer :: c = 7
integer, allocatable :: v(:)
end type
contains
subroutine s (x)
type(t), intent(in) :: x(:)
if (x(2)%v(2) /= 2) stop 1
end subroutine
end module
program p
use m
implicit none
type(t) :: ta(2)
ta(1) = t (1, [1])
ta(2) = t (2, [2, 2])
call s ((ta))
end program
$ gfortran -fsanitize=address pr.f90 && ./a.out
SUMMARY: AddressSanitizer: 144 byte(s) leaked in 1 allocation(s).
(allocated in p at the "call s ((ta))" line)
2) CLASS array and scalar CLASS:
module m
implicit none
type :: t
integer :: c = 7
integer, allocatable :: v(:)
end type
contains
subroutine sc (x)
class(t), intent(in) :: x(:)
if (x(2)%v(2) /= 2) stop 3
end subroutine
subroutine sq (x, z)
class(*), intent(in) :: x
complex, intent(inout) :: z
z = (0., 0.)
select type (x)
type is (complex)
if (x /= (5., 6.)) stop 1
end select
end subroutine
end module
program p
use m
implicit none
type(t), target :: ta(2)
class(t), pointer :: qa(:)
complex, target :: zs = (5., 6.)
class(*), pointer :: q
ta(1) = t (1, [1])
ta(2) = t (2, [2, 2])
qa => ta
call sc ((qa))
associate (b => (qa))
if (any (b%c /= [1, 2])) stop 2
end associate
q => zs
call sq ((q), zs)
end program
The element copies made by _copy for (qa) are never freed, both at "call sc
((qa))" and at the ASSOCIATE (ASan reports leaks from __copy_m_T), and the
program stops with STOP 1 because x in sq aliases zs instead of holding a copy
of its value.
