https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123254
Bug ID: 123254
Summary: OpenACC: SIGSEGV in GOACC_parallel_keyed when using
present() clause for derived type dummy argument
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: albert at tugraz dot at
Target Milestone: ---
current trunk; repo base upstream/master at
769041822723208bf85a91ac409b9b0bdae3fff0 (2025-12-22)
COLLECT_GCC=/opt/gcc16/bin/gfortran
COLLECT_LTO_WRAPPER=/opt/gcc16/libexec/gcc/x86_64-pc-linux-gnu/16.0.0/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
Target: x86_64-pc-linux-gnu
Thread model: posix
gcc version 16.0.0 20251222 (experimental) (GCC)
When a derived type is mapped with !$acc enter data copyin(p), then passed to a
subroutine as a dummy argument, using present(s) in the subroutine causes
SIGSEGV
in GOACC_parallel_keyed. The crash occurs in both host and device modes.
Reproducer:
program mre
use, intrinsic :: iso_fortran_env, only: dp => real64
implicit none
type :: params_t
real(dp) :: scale
end type params_t
type(params_t) :: p
real(dp) :: x(100), y(100)
integer :: i
p%scale = 2.0d0
x = [(real(i, dp), i = 1, 100)]
y = 0.0d0
!$acc enter data copyin(p)
call eval(p, x, y)
!$acc exit data delete(p)
print *, "y(1) =", y(1)
contains
subroutine eval(s, xv, yv)
type(params_t), intent(in) :: s
real(dp), intent(in) :: xv(:)
real(dp), intent(inout) :: yv(:)
integer :: j
!$acc parallel loop copy(yv) copyin(xv) present(s)
do j = 1, size(xv)
yv(j) = s%scale * xv(j)
end do
end subroutine
end program mre
Build and run:
gfortran -O2 -fopenacc -foffload=nvptx-none mre.f90 -o mre
ACC_DEVICE_TYPE=host ./mre
Output:
Program received signal SIGSEGV: Segmentation fault - invalid memory
reference.
#2 GOACC_parallel_keyed at ../../../../gcc/libgomp/oacc-parallel.c:201
Expected: Program prints y(1) = 2.0
Actual: SIGSEGV crash
Note: The same code works when the parallel loop is in the main program (not a
subroutine).
The bug is specific to using present() on a derived type dummy argument.
