[Bug fortran/40876] New: OpenMP private variable referenced in a statement function

["longb at cray dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Beginning with the OpenMP API Version 2.5, this case should fail at
compile-time.  The gfortran compiler does not reject this case, but gets a
segmentation fault at run-time.

The OpenMP API Version 3.0 (May 2008) lists the following restriction to a
private clause on p 91. lines 29-30:

" * Variables that appear in ... expressions for statement function
definitions, may not appear in a private clause."

Test case:

> cat ISU3136.f90
! derived from OpenMP test omp1/F2_6_2_1_2a.f90
!     According to OpenMP API Ver 2.5 May 2005 p. 75 lines 19/20
!     this is a negative test that should fail at compile-time.
      use omp_lib
      implicit none
      integer, parameter :: NT = 4
      integer :: nThreads(NT)
      integer :: a, st_func, i
      st_func() = a + 1

!$    call omp_set_dynamic(.false.)
!$    call omp_set_num_threads(NT)

!$omp parallel private(a)
      a = omp_get_thread_num()
!$omp barrier
      nThreads(omp_get_thread_num()+1) = st_func()
!$omp end parallel

      do i = 1, NT
          if(nThreads(i) /= i) then
              print*, 'FAIL: non-private copy is used in a statement function.'
          endif
      enddo

      END

> ftn -o x -fopenmp ISU3136.f90
> aprun -n 1 ./x
Application 1190869 exit signals: Segmentation fault
Application 1190869 resources: utime 0, stime 0

Expected output (using the Cray compiler) with a compile-time message:

> module swap PrgEnv-gnu PrgEnv-cray
> ftn -o x -h omp ISU3136.f90

!$omp parallel private(a)
                       ^  
ftn-1760 crayftn: ERROR $MAIN, File = ISU3136.f90, Line = 14, Column = 24 
  "A" is referenced in a statement function expression, so it must not be
specified in the PRIVATE, FIRSTPRIVATE or LASTPRIVATE clause.


-- 
           Summary: OpenMP private variable referenced in a statement
                    function
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: longb at cray dot com
 GCC build triplet: x86_64-suse-linux
  GCC host triplet: x86_64-suse-linux
GCC target triplet: x86_64-suse-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40876