openmp: Disallow reduction with var private in containing parallel even on scope...

The standard has a restriction:
"A list item that appears in a reduction clause of a scope construct must be
shared in the parallel region to which a corresponding scope region binds."
similar to the restriction for worksharing constructs, but we were checking
it only on worksharing constructs and not for scope and ICEd later on during
omp expansion.

2021-09-29  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/102504
	* gimplify.c (gimplify_scan_omp_clauses): Use omp_check_private even
	in OMP_SCOPE clauses, not just on worksharing construct clauses.

	* c-c++-common/gomp/scope-4.c: New test.

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 1067113..f4bc649 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -10195,7 +10195,7 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq *pre_p,
          if (outer_ctx)
            omp_notice_variable (outer_ctx, decl, true);
          if (check_non_private
-             && region_type == ORT_WORKSHARE
+             && (region_type == ORT_WORKSHARE || code == OMP_SCOPE)
              && (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_REDUCTION
                  || decl == OMP_CLAUSE_DECL (c)
                  || (TREE_CODE (OMP_CLAUSE_DECL (c)) == MEM_REF

diff --git a/gcc/testsuite/c-c++-common/gomp/scope-4.c b/gcc/testsuite/c-c++-common/gomp/scope-4.c
new file mode 100644 (file)
index 0000000..924ae9c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/scope-4.c
@@ -0,0 +1,11 @@
+/* PR middle-end/102504 */
+/* { dg-do compile } */
+
+int
+foo ()
+{
+  int r = 0;
+  #pragma omp scope reduction(+:r)     /* { dg-error "reduction variable 'r' is private in outer context" } */
+  r++;
+  return r;
+}