gimplify.c (should_warn_for_implicit_fallthrough): Check for FALLTHROUGH_LABEL_P here...

	* gimplify.c (should_warn_for_implicit_fallthrough): Check for
	FALLTHROUGH_LABEL_P here...
	(warn_implicit_fallthrough_r): ...not here.

	* c-c++-common/Wimplicit-fallthrough-22.c: New test.

From-SVN: r240864

gcc/ChangeLog

+2016-10-07  Marek Polacek  <polacek@redhat.com>
+
+	* gimplify.c (should_warn_for_implicit_fallthrough): Check for
+	FALLTHROUGH_LABEL_P here...
+	(warn_implicit_fallthrough_r): ...not here.
+
 2016-10-07  Bernd Schmidt  <bschmidt@redhat.com>
 
 	PR tree-optimization/77880

gcc/gimplify.c

@@ -1819,6 +1819,10 @@ should_warn_for_implicit_fallthrough (gimple_stmt_iterator *gsi_p, tree label)
 {
   gimple_stmt_iterator gsi = *gsi_p;
 
+  /* Don't warn if the label is marked with a "falls through" comment.  */
+  if (FALLTHROUGH_LABEL_P (label))
+    return false;
+
   /* Don't warn for a non-case label followed by a statement:
        case 0:
 	 foo ();
@@ -1905,7 +1909,6 @@ warn_implicit_fallthrough_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
 	if (gimple_code (next) == GIMPLE_LABEL
 	    && gimple_has_location (next)
 	    && (label = gimple_label_label (as_a <glabel *> (next)))
-	    && !FALLTHROUGH_LABEL_P (label)
 	    && prev != NULL)
 	  {
 	    struct label_entry *l;

gcc/testsuite/ChangeLog

+2016-10-07  Marek Polacek  <polacek@redhat.com>
+
+	* c-c++-common/Wimplicit-fallthrough-22.c: New test.
+
 2016-10-07  Bernd Schmidt  <bschmidt@redhat.com>
 
 	PR c++/69733

gcc/testsuite/c-c++-common/Wimplicit-fallthrough-22.c

+/* { dg-do compile } */
+/* { dg-options "-Wimplicit-fallthrough" } */
+
+void bar (int);
+
+void
+foo (int i)
+{
+  switch (i)
+    {
+    case 1:
+      bar (1);
+      /* FALLTHROUGH */
+    case 2:
+      bar (2); /* { dg-warning "statement may fall through" } */
+    case 3:
+      bar (3); /* { dg-warning "statement may fall through" } */
+    case 4:
+      bar (4);
+    default:
+      break;
+    }
+}