https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114613
Bug ID: 114613
Summary: ALLOCATE with SOURCE forgets to finalize temporary
instances
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: vterzi1996 at gmail dot com
Target Milestone: ---
Consider the following minimal example:
```
module lib
private
type,public::list
contains
final::list_final
end type
interface list
procedure list_new
end interface
contains
function list_new()result(this)
type(list)::this
print*,'list_new'
end
subroutine list_final(this)
type(list),intent(inout)::this
print*,'list_final'
end
end
program prog
use lib
type(list),allocatable::obj
allocate(obj,source=list()) ! obj=list()
end
```
Only `list_new` is printed, since `list_final` is never called to finalize the
temporary `list()` instance after the `allocate` statement, what can lead to a
memory leak. This issue can be fixed by replacing `allocate(obj,source=list())`
with `obj=list()`.
A larger example was already discussed here:
https://stackoverflow.com/questions/78279925/right-way-to-allocate-type-instances-containing-pointers-in-fortran
and one of the experienced Stack Overflow users thinks that it is a bug of
gfortran.
