openmp: Diagnose threadprivate OpenMP loop iterators

We weren't diagnosing the
The loop iteration variable may not appear in a threadprivate directive.
restriction which used to be in 5.0 just among the Worksharing-Loop
restrictions but in 5.1 it is among Canonical Loop Nest Form restrictions.

This patch diagnoses those.

2021-10-30  Jakub Jelinek  <jakub@redhat.com>

	* gimplify.c (gimplify_omp_for): Diagnose threadprivate iterators.

	* c-c++-common/gomp/loop-10.c: New test.

2 files changed, 53 insertions, 0 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index d8e4b13..8bb54fd 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -12298,6 +12298,24 @@ gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
 	  gimplify_omp_ctxp->loop_iter_var.quick_push (decl);
 	}
 
+      if (for_stmt == orig_for_stmt)
+	{
+	  tree orig_decl = decl;
+	  if (OMP_FOR_ORIG_DECLS (for_stmt))
+	    {
+	      tree orig_decl = TREE_VEC_ELT (OMP_FOR_ORIG_DECLS (for_stmt), i);
+	      if (TREE_CODE (orig_decl) == TREE_LIST)
+		{
+		  orig_decl = TREE_PURPOSE (orig_decl);
+		  if (!orig_decl)
+		    orig_decl = decl;
+		}
+	    }
+	  if (is_global_var (orig_decl) && DECL_THREAD_LOCAL_P (orig_decl))
+	    error_at (EXPR_LOCATION (for_stmt),
+		      "threadprivate iteration variable %qD", orig_decl);
+	}
+
       /* Make sure the iteration variable is private.  */
       tree c = NULL_TREE;
       tree c2 = NULL_TREE;
diff --git a/gcc/testsuite/c-c++-common/gomp/loop-10.c b/gcc/testsuite/c-c++-common/gomp/loop-10.c
new file mode 100644
index 0000000..1229e61
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/loop-10.c
@@ -0,0 +1,35 @@
+int a, b;
+#pragma omp threadprivate (a, b)
+
+void
+foo (void)
+{
+  #pragma omp for				/* { dg-error "threadprivate iteration variable 'a'" } */
+  for (a = 0; a < 32; a++)
+    ;
+  #pragma omp parallel for collapse(2)		/* { dg-error "threadprivate iteration variable 'a'" "" { target c } } */
+  for (a = 0; a < 32; a++)			/* { dg-error "threadprivate iteration variable 'b'" "" { target c } .-1 } */
+    for (b = 0; b < 32; b++)			/* { dg-error "threadprivate iteration variable 'a'" "" { target c++ } .-1 } */
+      ;						/* { dg-error "threadprivate iteration variable 'b'" "" { target c++ } .-2 } */
+  #pragma omp simd				/* { dg-error "threadprivate iteration variable 'a'" } */
+  for (a = 0; a < 32; a++)
+    ;
+  #pragma omp taskloop				/* { dg-error "threadprivate iteration variable 'a'" } */
+  for (a = 0; a < 32; a++)
+    ;
+  #pragma omp loop bind(thread)			/* { dg-error "threadprivate iteration variable 'a'" } */
+  for (a = 0; a < 32; a++)
+    ;
+}
+
+void
+bar (void)
+{
+  #pragma omp distribute collapse(2)		/* { dg-error "threadprivate iteration variable 'a'" } */
+  for (a = 0; a < 32; a++)			/* { dg-error "threadprivate iteration variable 'b'" "" { target *-*-* } .-1 } */
+    for (b = 0; b < a; b++)
+      ;
+  #pragma omp distribute parallel for simd	/* { dg-error "threadprivate iteration variable 'a'" "" { target c } } */
+  for (a = 0; a < 32; a++)			/* { dg-error "threadprivate iteration variable 'a'" "" { target c++ } } */
+    ;
+}