https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123938
Bug ID: 123938
Summary: [16-regession] Memory leak on assignment
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: abensonca at gcc dot gnu.org
Target Milestone: ---
The following causes a memory leak on assignment with gfortran 16:
module bugMod
private
public :: df1
type, abstract :: t1
end type t1
type, extends(t1) :: t1g
logical, allocatable :: i
end type t1g
type :: df0
private
contains
procedure :: df0Assign
generic :: assignment(=) => df0Assign
end type df0
type, extends(df0) :: df1
private
class(t1), allocatable :: c
end type df1
interface df1
module procedure df1c
end interface df1
contains
subroutine df0Assign(self,from)
implicit none
class(df0), intent(out) :: self
class(df0), intent(in ) :: from
return
end subroutine df0Assign
function df1c() result(self)
type(df1) :: self
allocate(t1g :: self%c)
select type (c => self%c)
type is (t1g)
allocate(c%i) ! this allocation is leaked
end select
return
end function df1c
end module bugMod
program bugProg
use :: bugMod
type(df1) :: d
d=df1()
end program bugProg
> gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/carnegie/nobackup/users/abenson/upstream/libexec/gcc/x86_64-pc-linux-gnu/16.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure
--prefix=/carnegie/nobackup/users/abenson/upstream --disable-multilib
--enable-checking=release --enable-host-shared --with-pic
--enable-languages=c,c++,fortran,jit,lto
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.1 20260130 (experimental) (GCC)
> gfortran bug.F90 -g -fsanitize=leak
> ./a.out
=================================================================
==2829789==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 4 byte(s) in 1 object(s) allocated from:
#0 0x147a3e0f0f4b in malloc
../../../../libsanitizer/lsan/lsan_interceptors.cpp:74
#1 0x000000401e9b in __bugmod_MOD_df1c
/carnegie/scidata/users/abenson/Galacticus/galacticus_finalization/bug.F90:42
#2 0x000000401fbb in bugprog
/carnegie/scidata/users/abenson/Galacticus/galacticus_finalization/bug.F90:52
#3 0x000000402047 in main
/carnegie/scidata/users/abenson/Galacticus/galacticus_finalization/bug.F90:50
#4 0x147a3da2a60f in __libc_start_call_main (/lib64/libc.so.6+0x2a60f)
(BuildId: e650335ac8463e9e58c04e07c6f36c5f826ed953)
SUMMARY: LeakSanitizer: 4 byte(s) leaked in 1 allocation(s).
With ifort, no leak is reported. gfortran-15.2 also reports no leak, so this
seems to be a regression.
