[OpenACC] update fortran nested parallelism error messages

	gcc/fortran/
	* openmp.c (resolve_oacc_loop_blocks):

	gcc/testsuite/
	* gfortran.dg/goacc/nested-parallelism.f90: New test.

From-SVN: r264536

gcc/fortran/ChangeLog

+2018-09-24  Bernhard Reuther-Fischer  <aldot@gcc.gnu.org>
+	    Cesar Philippidis  <cesar@codesourcery.com>
+
+	* openmp.c (resolve_oacc_loop_blocks):
+
 2018-09-23  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/87397

gcc/fortran/openmp.c

@@ -5853,7 +5853,7 @@ resolve_oacc_loop_blocks (gfc_code *code)
 			     &code->loc);
 		if (c->code->ext.omp_clauses->vector)
 		  gfc_error ("Loop parallelized across gangs is not allowed "
-			     "inside loop parallelized across workers at %L",
+			     "inside loop parallelized across vectors at %L",
 			     &code->loc);
 	      }
 	    if (code->ext.omp_clauses->worker)

gcc/testsuite/ChangeLog

+2018-09-24  Cesar Philippidis  <cesar@codesourcery.com>
+
+	* gfortran.dg/goacc/nested-parallelism.f90: New test.
+
 2018-09-24  Ilya Leoshkevich  <iii@linux.ibm.com>
 
 	PR target/80080

gcc/testsuite/gfortran.dg/goacc/nested-parallelism.f90

+! Verify the invalid gang, worker, vector parallelism error messages.
+
+program np
+  integer, parameter :: n = 100
+  integer :: i, j, k
+
+  !$acc parallel loop gang
+  do i = 1, n
+     !$acc loop gang ! { dg-error "gangs is not allowed inside another loop parallelized across gangs" }
+     do j = 1, n
+     end do
+
+     !$acc loop worker
+     do j = 1, n
+     end do
+
+     !$acc loop vector
+     do j = 1, n
+     end do     
+  end do
+  
+  !$acc parallel loop worker
+  do i = 1, n
+     !$acc loop gang ! { dg-error "gangs is not allowed inside loop parallelized across workers" }
+     do j = 1, n
+     end do
+
+     !$acc loop worker ! { dg-error "workers is not allowed inside another loop parallelized across workers" }
+     do j = 1, n
+     end do
+
+     !$acc loop vector
+     do j = 1, n
+     end do     
+  end do
+
+  !$acc parallel loop vector
+  do i = 1, n
+     !$acc loop gang ! { dg-error "gangs is not allowed inside loop parallelized across vectors" }
+     do j = 1, n
+     end do
+
+     !$acc loop worker ! { dg-error "workers is not allowed inside another loop parallelized across vectors" }
+     do j = 1, n
+     end do
+
+     !$acc loop vector ! { dg-error "vectors is not allowed inside another loop parallelized across vectors" }
+     do j = 1, n
+     end do     
+  end do
+end program np