re PR middle-end/79537 (ICE in gimplify_expr, at gimplify.c:12009)

	PR middle-end/79537
	* gimplify.c (gimplify_expr): Handle unused *&&L;.

	* gcc.dg/comp-goto-4.c: New.

From-SVN: r245604

gcc/ChangeLog

+2017-02-20  Marek Polacek  <polacek@redhat.com>
+
+	PR middle-end/79537
+	* gimplify.c (gimplify_expr): Handle unused *&&L;.
+
 2017-02-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/79568

gcc/gimplify.c

@@ -11976,8 +11976,11 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
   if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
     {
       /* We aren't looking for a value, and we don't have a valid
-	 statement.  If it doesn't have side-effects, throw it away.  */
-      if (!TREE_SIDE_EFFECTS (*expr_p))
+	 statement.  If it doesn't have side-effects, throw it away.
+	 We can also get here with code such as "*&&L;", where L is
+	 a LABEL_DECL that is marked as FORCED_LABEL.  */
+      if (TREE_CODE (*expr_p) == LABEL_DECL
+	  || !TREE_SIDE_EFFECTS (*expr_p))
 	*expr_p = NULL;
       else if (!TREE_THIS_VOLATILE (*expr_p))
 	{

gcc/testsuite/ChangeLog

+2017-02-20  Marek Polacek  <polacek@redhat.com>
+
+	PR middle-end/79537
+	* gcc.dg/comp-goto-4.c: New test.
+
 2017-02-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/79568

gcc/testsuite/gcc.dg/comp-goto-4.c

+/* PR middle-end/79537 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+/* { dg-require-effective-target indirect_jumps } */
+/* { dg-require-effective-target label_values } */
+
+void
+f (void)
+{
+L:
+  *&&L;
+}
+
+void
+f2 (void)
+{
+   void *p;
+L:
+   p = &&L;
+   *p; /* { dg-warning "dereferencing 'void \\*' pointer" } */
+}