Fortran: Implement OpenMP 5.1 scope construct

Fortran version to commit e45483c7c4badc4bf2d6ced22360ce1ab172967f,
which implemented OpenMP's scope construct for C and C++.
Most testcases are based on the C testcases; it also contains some
testcases which existed previously but had no Fortran equivalent.

gcc/fortran/ChangeLog:

	* dump-parse-tree.c (show_omp_node, show_code_node): Handle
	EXEC_OMP_SCOPE.
	* gfortran.h (enum gfc_statement): Add ST_OMP_(END_)SCOPE.
	(enum gfc_exec_op): Add EXEC_OMP_SCOPE.
	* match.h (gfc_match_omp_scope): New.
	* openmp.c (OMP_SCOPE_CLAUSES): Define
	(gfc_match_omp_scope): New.
	(gfc_match_omp_cancellation_point, gfc_match_omp_end_nowait):
	Improve error diagnostic.
	(omp_code_to_statement): Handle ST_OMP_SCOPE.
	(gfc_resolve_omp_directive): Handle EXEC_OMP_SCOPE.
	* parse.c (decode_omp_directive, next_statement,
	gfc_ascii_statement, parse_omp_structured_block,
	parse_executable): Handle OpenMP's scope construct.
	* resolve.c (gfc_resolve_blocks): Likewise
	* st.c (gfc_free_statement): Likewise
	* trans-openmp.c (gfc_trans_omp_scope): New.
	(gfc_trans_omp_directive): Call it.
	* trans.c (trans_code): handle EXEC_OMP_SCOPE.

libgomp/ChangeLog:

	* testsuite/libgomp.fortran/scope-1.f90: New test.
	* testsuite/libgomp.fortran/task-reduction-16.f90: New test.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/scan-1.f90:
	* gfortran.dg/gomp/cancel-1.f90: New test.
	* gfortran.dg/gomp/cancel-4.f90: New test.
	* gfortran.dg/gomp/loop-4.f90: New test.
	* gfortran.dg/gomp/nesting-1.f90: New test.
	* gfortran.dg/gomp/nesting-2.f90: New test.
	* gfortran.dg/gomp/nesting-3.f90: New test.
	* gfortran.dg/gomp/nowait-1.f90: New test.
	* gfortran.dg/gomp/reduction-task-1.f90: New test.
	* gfortran.dg/gomp/reduction-task-2.f90: New test.
	* gfortran.dg/gomp/reduction-task-2a.f90: New test.
	* gfortran.dg/gomp/reduction-task-3.f90: New test.
	* gfortran.dg/gomp/scope-1.f90: New test.
	* gfortran.dg/gomp/scope-2.f90: New test.

1 files changed, 21 insertions, 2 deletions

diff --git a/gcc/fortran/openmp.c b/gcc/fortran/openmp.c
index 1bce43c..9675b65 100644
--- a/gcc/fortran/openmp.c
+++ b/gcc/fortran/openmp.c
@@ -3150,6 +3150,8 @@ cleanup:
 #define OMP_LOOP_CLAUSES \
   (omp_mask (OMP_CLAUSE_BIND) | OMP_CLAUSE_COLLAPSE | OMP_CLAUSE_ORDER	\
    | OMP_CLAUSE_PRIVATE | OMP_CLAUSE_LASTPRIVATE | OMP_CLAUSE_REDUCTION)
+#define OMP_SCOPE_CLAUSES \
+  (omp_mask (OMP_CLAUSE_PRIVATE) | OMP_CLAUSE_REDUCTION)
 #define OMP_SECTIONS_CLAUSES \
   (omp_mask (OMP_CLAUSE_PRIVATE) | OMP_CLAUSE_FIRSTPRIVATE		\
    | OMP_CLAUSE_LASTPRIVATE | OMP_CLAUSE_REDUCTION)
@@ -4488,6 +4490,13 @@ gfc_match_omp_scan (void)
 
 
 match
+gfc_match_omp_scope (void)
+{
+  return match_omp (EXEC_OMP_SCOPE, OMP_SCOPE_CLAUSES);
+}
+
+
+match
 gfc_match_omp_sections (void)
 {
   return match_omp (EXEC_OMP_SECTIONS, OMP_SECTIONS_CLAUSES);
@@ -4975,7 +4984,11 @@ gfc_match_omp_cancellation_point (void)
   gfc_omp_clauses *c;
   enum gfc_omp_cancel_kind kind = gfc_match_omp_cancel_kind ();
   if (kind == OMP_CANCEL_UNKNOWN)
-    return MATCH_ERROR;
+    {
+      gfc_error ("Expected construct-type PARALLEL, SECTIONS, DO or TASKGROUP "
+		 "in $OMP CANCELLATION POINT statement at %C");
+      return MATCH_ERROR;
+    }
   if (gfc_match_omp_eos () != MATCH_YES)
     {
       gfc_error ("Unexpected junk after $OMP CANCELLATION POINT statement "
@@ -4998,7 +5011,10 @@ gfc_match_omp_end_nowait (void)
     nowait = true;
   if (gfc_match_omp_eos () != MATCH_YES)
     {
-      gfc_error ("Unexpected junk after NOWAIT clause at %C");
+      if (nowait)
+	gfc_error ("Unexpected junk after NOWAIT clause at %C");
+      else
+	gfc_error ("Unexpected junk at %C");
       return MATCH_ERROR;
     }
   new_st.op = EXEC_OMP_END_NOWAIT;
@@ -7448,6 +7464,8 @@ omp_code_to_statement (gfc_code *code)
       return ST_OMP_DO_SIMD;
     case EXEC_OMP_SCAN:
       return ST_OMP_SCAN;
+    case EXEC_OMP_SCOPE:
+      return ST_OMP_SCOPE;
     case EXEC_OMP_SIMD:
       return ST_OMP_SIMD;
     case EXEC_OMP_TARGET:
@@ -7948,6 +7966,7 @@ gfc_resolve_omp_directive (gfc_code *code, gfc_namespace *ns)
     case EXEC_OMP_PARALLEL_MASKED:
     case EXEC_OMP_PARALLEL_MASTER:
     case EXEC_OMP_PARALLEL_SECTIONS:
+    case EXEC_OMP_SCOPE:
     case EXEC_OMP_SECTIONS:
     case EXEC_OMP_SINGLE:
     case EXEC_OMP_TARGET: