There seems to be a bug involving procedure pointers and OpenMP when using the default(none) clause when starting a parallel region. This means that if there is a procedure pointer inside a parallel region, and a default(none) clause is present, a compile time error will occur. If the default(none) clause is removed, or replaced by default(shared), the program compiles properly.
I think GNU Fortran is confusing whether a procedure pointer is a variable or not. If it is a variable then it must be defined when default(none) is specified. However, it is not allowed as a variable name in a shared clause. Is a procedure pointer a variable or not? FYI the Intel compiler allows all conventions shown below. I know Intel Fortran is often loose on enforcing standard compliance, so I don't know which method is right, but something should be done to allow a default(none) clause with procedure pointers. Best Regards, David Bal P.S. This problem occurs with GFortran 4.6, 4.8 and the latest 4.9 experimental. ! EXAMPLE CODE BELOW module test contains subroutine double(a) integer, intent(in out) :: a a = a * 2 end subroutine double end module test program procedure_pointer_openmp_bug use test implicit none interface subroutine My_Interface(A) integer, intent(in out) :: a end subroutine My_Interface end interface procedure (My_Interface), pointer :: math integer, parameter :: nA = 10 integer, dimension(nA) :: A = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] integer :: i math => double ! ***VERSION 1 - Error: ‘math’ not specified in enclosing parallel ! !$omp parallel do & ! !$omp default(none) & ! !$omp shared(A) ! ***VERSION 2 - Error: Object 'math' is not a variable at (1) ! !$omp parallel do & ! !$omp default(none) & ! !$omp shared(A, math) ! ***VERSION 3 - COMPILES AND RUNS ! !$omp parallel do & ! !$omp default(shared) & ! !$omp shared(A) ! ***VERSION 4 - COMPILES AND RUNS !$omp parallel do & !$omp shared(A) do i = 1, nA call math(A(i)) end do !$omp end parallel do write (*,*) A end program procedure_pointer_openmp_bug ! EXAMPLE CODE ABOVE
