OffTarget

Observed issues › oop/gcc-polymorphic-dispatch-abort

Appears to behave incorrectlyCrashes or aborts at run time · Fortran · OpenMP · Open

dynamic dispatch of a type-bound procedure in device code aborts

Legality: contested. An independent adjudicating reading finds the result not required: The spec requires only that type-bound procedures accessed in a target region appear in a declare target directive. The specific bindings sq_area, rect_area and area_of carry declare target, so that rule is met. Neither reading finds a rule on making the dynamic type information (descriptor or vtable) of a CLASS dummy usable on the device. q and rr are mapped as non-polymorphic objects whose passed class descriptors point to host data. How this is checked

A declare target function calls a type-bound procedure through a CLASS dummy argument (every bound procedure declare target). GCC 16.2 compiles it and the program aborts at run time. The same program calling the binding on the non-polymorphic objects works. AFAR runs it correctly.

Affected variants

CompilerMI300A gfx942
unified memory (XNACK 1)
MI300A gfx942
copy (XNACK 0)
MI250X gfx90a
copy (XNACK 0)
MI300X gfx942
copy (XNACK 0)
MI350X gfx950
copy (XNACK 0)
A100 sm_80
separate memory
A100 sm_80
managed memory
AFAR 24.3.0correctcorrectunknown
not run
correctcorrectn/an/a
CCE 19.0.0fails another wayfails another wayunknown
not run
unknown
not run
unknown
not run
n/an/a
CCE 20.0.2fails another wayfails another wayunknown
not run
unknown
not run
unknown
not run
n/an/a
CCE 21.0.3fails another wayfails another wayunknown
not run
unknown
not run
unknown
not run
n/an/a
CCE 21.0.4fails another wayfails another wayunknown
not run
unknown
not run
unknown
not run
n/an/a
NVHPC 25.11n/an/an/an/an/afails another wayfails another way
NVHPC 26.9n/an/an/an/an/afails another wayfails another way
GCC 16.2.0fails another waybehaves incorrectlybehaves incorrectlybehaves incorrectlybehaves incorrectlybehaves incorrectlyn/a

"behaves incorrectly" / "not supported": this issue, confirmed in up to four environments (another build directory, another node, a repeat). "fails another way": a different failure, not counted as this issue. "unknown": not run there, or the runs disagree.

Messages

ResultCompiler and GPUMessage
behaves incorrectlyGCC 16.2.0, MI300A copy
show
Memory access fault by GPU node-7 (Agent handle: 0x591bc0) on address 0x401000. Reason: Unknown.
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0  0x15555469662f in ???
#1  0x1555546965af in ???
#2  0x155554669ee4 in ???
#3  0x1555540d6bfe in ???
#4  0x1555540d4288 in ???
behaves incorrectlyGCC 16.2.0, MI250X
show
Memory access fault by GPU node-9 (Agent handle: 0x783070) on address 0x400000. Reason: Unknown.
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0  0x15555469662f in ???
#1  0x1555546965af in ???
#2  0x155554669ee4 in ???
#3  0x1555540d6bfe in ???
#4  0x1555540d4288 in ???
behaves incorrectlyGCC 16.2.0, MI300X
show
Memory access fault by GPU node-1 (Agent handle: 0x1264f00) on address 0x401000. Reason: Unknown.
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0  0x7febe423ebef in ???
#1  0x7febe428bedc in ???
#2  0x7febe423eb45 in ???
#3  0x7febe4228832 in ???
#4  0x7febe3e89a5e in ???
behaves incorrectlyGCC 16.2.0, MI350X
show
Memory access fault by GPU node-1 (Agent handle: 0xafa5c0) on address 0x401000. Reason: Unknown.
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0  0x7f5d3683fc2f in ???
#1  0x7f5d3688d02c in ???
#2  0x7f5d3683fb85 in ???
#3  0x7f5d36829872 in ???
#4  0x7f5d36489a5e in ???
behaves incorrectlyGCC 16.2.0, A100 separate
show
libgomp: cuCtxSynchronize error: an illegal memory access was encountered
libgomp: cuModuleGetFunction (__do_global_dtors__entry) error: an illegal memory access was encountered
libgomp: cuMemFree_v2 error: an illegal memory access was encountered
libgomp: device finalization failed
fails another wayCCE 19.0.0, MI300A unified
CCE 19.0.0, MI300A copy
show
Warning:
 Headers and libraries from cray-libsci/25.03.0 will be ignored because depends on PE_MPICH which is unavailable..
lld: error: undefined symbol: __GET_TYPE_BOUND_PROC
>>> referenced by <dir>:(oop_$ck_L75_2)
>>> referenced by <dir>:(oop_$ck_L75_2)
fails another wayCCE 20.0.2, MI300A unified
CCE 20.0.2, MI300A copy
show
Warning:
 Headers and libraries from cray-libsci/25.09.0 will be ignored because depends on PE_MPICH which is unavailable..
lld: error: undefined symbol: __GET_TYPE_BOUND_PROC
>>> referenced by <dir>:(oop_$ck_L75_2)
>>> referenced by <dir>:(oop_$ck_L75_2)
fails another wayCCE 21.0.3, MI300A unified
CCE 21.0.3, MI300A copy
show
Warning:
 Headers and libraries from cray-libsci/26.03.0 will be ignored because depends on PE_MPICH which is unavailable..
lld: error: undefined symbol: __GET_TYPE_BOUND_PROC
>>> referenced by <dir>//cooltmpdir-jp5qGf/repro-cce-openmppost_lld.amdgpu.lto.o:(oop_$ck_L75_2)
>>> referenced by <dir>//cooltmpdir-jp5qGf/repro-cce-openmppost_lld.amdgpu.lto.o:(oop_$ck_L75_2)
fails another wayCCE 21.0.4, MI300A unified
CCE 21.0.4, MI300A copy
show
Warning:
 Headers and libraries from cray-libsci/26.03.0 will be ignored because depends on PE_MPICH which is unavailable..
lld: error: undefined symbol: __GET_TYPE_BOUND_PROC
>>> referenced by <dir>//cooltmpdir-jjWH3y/repro-cce-openmppost_lld.amdgpu.lto.o:(oop_$ck_L75_2)
>>> referenced by <dir>//cooltmpdir-jjWH3y/repro-cce-openmppost_lld.amdgpu.lto.o:(oop_$ck_L75_2)
fails another wayNVHPC 25.11, A100 separate
NVHPC 25.11, A100 managed
show
NVFORTRAN-W-0155-Compiler failed to translate accelerator region (see -Minfo messages): No device symbol for address reference (site-oop--gcc-polymorphic-dispatch-abort.f90: 80)
NVFORTRAN-F-0704-Compilation aborted due to previous errors. (site-oop--gcc-polymorphic-dispatch-abort.f90)
NVFORTRAN/x86-64 Linux 25.11-0: compilation aborted
fails another wayNVHPC 26.9, A100 separate
NVHPC 26.9, A100 managed
show
NVFORTRAN-W-0155-Compiler failed to translate accelerator region (see -Minfo messages): No device symbol for address reference (site-oop--gcc-polymorphic-dispatch-abort.f90: 80)
NVFORTRAN-F-0704-Compilation aborted due to previous errors. (site-oop--gcc-polymorphic-dispatch-abort.f90)
NVFORTRAN/x86-64 Linux 26.9-0: compilation aborted
fails another wayGCC 16.2.0, MI300A unified
show
RUN_TIMEOUT

Reproduce

GCC 16.2.0, MI300A copy

export LD_LIBRARY_PATH=$GCC_16_2/lib64:/opt/rocm-7.2.1/lib
$GCC_16_2/bin/gfortran -fopenmp -foffload=amdgcn-amdhsa -foffload-options=amdgcn-amdhsa=-march=gfx942 -O2 repro.f90 -o repro
HSA_XNACK=0 OMP_TARGET_OFFLOAD=mandatory ./repro

GCC 16.2.0, A100 separate

export PATH=/usr/local/cuda/bin:$PATH
export LD_LIBRARY_PATH=$GCC_16_2/lib64
$GCC_16_2/bin/gfortran -fopenmp -foffload=nvptx-none -foffload-options=nvptx-none=-march=sm_80 -foffload-options=nvptx-none=-latomic -O2 repro.f90 -o repro
OMP_TARGET_OFFLOAD=mandatory ./repro

AFAR 24.3.0, MI300A unified (runs correctly)

$AFAR/bin/amdflang -fopenmp --offload-arch=gfx942 -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro
Program (89 lines)
! # Finding (fortran-oop): a type-bound call through a CLASS dummy in device code aborts at run time
!
! - toolchains and modes that fail: gcc_g90 (GCC 16.2 (gfx90a): copy), gcc_sm80 (GCC 16.2 (sm_80): copy); -O2
! - build: gfortran -fopenmp -foffload=amdgcn-amdhsa -foffload-options=amdgcn-amdhsa=-march=gfx90a -O2 (gcc_g90);
!   -foffload=nvptx-none -foffload-options=nvptx-none=-march=sm_80 -foffload-options=nvptx-none=-latomic (gcc_sm80)
! - failure: crash (SIGABRT); OMP_TARGET_OFFLOAD=mandatory
! - observed: the program compiles and aborts (SIGABRT, a backtrace without symbols) in every run
! - expected: `r1= 29`
! - rule: 5.2 §1.2.6 p.19 l.1-3 (every type-bound procedure accessed is declare target)
! - same-compiler control: the same program with the region calling the binding on the TYPE objects instead of through area_of's
!   CLASS(shape) dummy (controls/poly-dispatch-static.f90, one change): `r1= 29`, check=pass in the stored run and the gate's four
!   environments a-d on both GPUs (results/oop/probe/ctl2.*.poly-dispatch-static.gcc.jsonl, (c) on another Tioga node;
!   results/oop/probe/ctl2.*.poly-dispatch-static.wt-gcc_sm80.jsonl, (c) on another A100)
! - other families: AFAR correct; CCE fails at the device link (cce-polymorphic-dispatch-device-link.f90)
! - gate and confirmer: 8 cells, 8 confirmed in the gate's four environments (a-d; results/oop/main/gate_reruns*.jsonl); confirmer
!   (results/oop/main/confirm.jsonl): compiler_bug (R20-runtime-bug) 4, needs_human (R22-expected-weak) 4; R22-expected-weak means
!   the expected value has one source, the generator's Python model; the values follow from the program's arithmetic (checked by
!   hand), and AFAR print them on this program
! - programs (4): oop-poly-dispatch, oop-poly-dispatch-loop, oop-poly-parent-call, oop-tbp-nested-call (offload/engine/oop_gen.py;
!   this file is the first one)
! - legality: for the gcc cells: the rules (offload.engine.rules, with the fortran-oop restrictions) and AFAR's flang front end
!   (-fsyntax-only) and a CCE compile and NVHPC 26.9 nvfortran (compile only) (tools/campaigns/oop.py legality,
!   results/oop/main/legality.json)
module oop_m
  implicit none
  integer, parameter :: n = 64
  type, abstract :: shape
    integer :: id = 0
  contains
    procedure(area_if), deferred :: area
  end type shape
  abstract interface
    integer function area_if(s)
      import :: shape
      class(shape), intent(in) :: s
    end function area_if
  end interface
  type, extends(shape) :: sq
    integer :: side = 0
  contains
    procedure :: area => sq_area
  end type sq
  type, extends(shape) :: rect
    integer :: w = 0, h = 0
  contains
    procedure :: area => rect_area
  end type rect
contains
  integer function sq_area(s)
    !$omp declare target
    class(sq), intent(in) :: s
    sq_area = s%side * s%side
  end function sq_area
  integer function rect_area(s)
    !$omp declare target
    class(rect), intent(in) :: s
    rect_area = s%w * s%h
  end function rect_area
  integer function area_of(s)
    !$omp declare target
    class(shape), intent(in) :: s
    area_of = s%area()
  end function area_of
end module oop_m

program oop
  use omp_lib
  use oop_m
  implicit none
  integer :: host_flag
  logical :: ok
  integer :: r1
  type(sq) :: q
  type(rect) :: rr
  host_flag = 1
  !$omp target map(from: host_flag)
  host_flag = merge(1, 0, omp_is_initial_device())
  !$omp end target
  q%side = 3
  rr%w = 4
  rr%h = 5
  !$omp target map(tofrom: q, rr) map(from: r1)
  r1 = area_of(q) + area_of(rr)
  !$omp end target
  ok = .true.
  ok = ok .and. (r1 == 29)
  print '(a,i0)', 'r1= ', r1
  print '(a,i0,a,a)', 'RESULT ran_on_host=', host_flag, ' check=', merge('pass', 'fail', ok)
end program oop

Source in the repository

Something to add? Dispute its legality · Report it fixed in a newer release · Report a mistake on this page

Expected and observed

Observed where it behaves incorrectly

Memory access fault by GPU node-7 (Agent handle: 0x591bc0) on address 0x401000. Reason: Unknown.
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0  0x15555469662f in ???
#1  0x1555546965af in ???
#2  0x155554669ee4 in ???
#3  0x1555540d6bfe in ???
#4  0x1555540d4288 in ???

What the specification requires

The specification text this program relies on and the compiler is expected to support.

OpenMP 5.2 §1.2.6 p.19 l.1-3

Evidence

Same compiler, one change

  • the same program; the binding is called on the TYPE objects (statically resolved) instead of through a CLASS dummy: not run yet
    Control program
    ! control for oop-poly-dispatch: the same program; one change: the region calls the binding on the TYPE objects
    ! (statically resolved) instead of through area_of's CLASS(shape) dummy
    ! fortran-oop poly/dispatch (OpenMP 5.2, free-form Fortran):
    ! dynamic dispatch of a deferred binding (abstract type) through a CLASS(shape) dummy on the
    !   device
    ! spec: OpenMP 5.2 §1.2.6 p.19 l.1-3 (type-bound procedures accessed in a target region appear in a
    !   declare target directive); OpenMP 5.2 §7.8.1 p.205-207 (declare target, procedures)
    ! legality: defined
    ! expected (computed by compliance/oop_gen.py): r1= 29
    module oop_m
      implicit none
      integer, parameter :: n = 64
      type, abstract :: shape
        integer :: id = 0
      contains
        procedure(area_if), deferred :: area
      end type shape
      abstract interface
        integer function area_if(s)
          import :: shape
          class(shape), intent(in) :: s
        end function area_if
      end interface
      type, extends(shape) :: sq
        integer :: side = 0
      contains
        procedure :: area => sq_area
      end type sq
      type, extends(shape) :: rect
        integer :: w = 0, h = 0
      contains
        procedure :: area => rect_area
      end type rect
    contains
      integer function sq_area(s)
        !$omp declare target
        class(sq), intent(in) :: s
        sq_area = s%side * s%side
      end function sq_area
      integer function rect_area(s)
        !$omp declare target
        class(rect), intent(in) :: s
        rect_area = s%w * s%h
      end function rect_area
      integer function area_of(s)
        !$omp declare target
        class(shape), intent(in) :: s
        area_of = s%area()
      end function area_of
    end module oop_m
    
    program oop
      use omp_lib
      use oop_m
      implicit none
      integer :: host_flag
      logical :: ok
      integer :: r1
      type(sq) :: q
      type(rect) :: rr
      host_flag = 1
      !$omp target map(from: host_flag)
      host_flag = merge(1, 0, omp_is_initial_device())
      !$omp end target
      q%side = 3
      rr%w = 4
      rr%h = 5
      !$omp target map(tofrom: q, rr) map(from: r1)
      r1 = q%area() + rr%area()
      !$omp end target
      ok = .true.
      ok = ok .and. (r1 == 29)
      print '(a,i0)', 'r1= ', r1
      print '(a,i0,a,a)', 'RESULT ran_on_host=', host_flag, ' check=', merge('pass', 'fail', ok)
    end program oop
    

Other compilers run it correctly

AFAR 24.3.0