From patchwork Tue Jul  3 08:04:48 2012
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Subject: [C++] Fix ICE with computed goto (PR c++/53812)
From: Jakub Jelinek <jakub@redhat.com>
X-Patchwork-Id: 168728
Message-Id: <20120703080448.GI20264@tucnak.redhat.com>
To: Jason Merrill <jason@redhat.com>
Cc: gcc-patches@gcc.gnu.org
Date: Tue, 3 Jul 2012 10:04:48 +0200

Hi!

We ICE on this testcase since forever, because the computed goto's operand
needs cleanups and doesn't have corresponding CLEANUP_POINT_EXPR emitted
anywhere.  Given that the operand is void * and only valid values for it are
&& LABEL_DECLs, I think it is ok to perform the cleanups before the actual
goto.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2012-07-03  Jakub Jelinek  <jakub@redhat.com>

	PR c++/53812
	* semantics.c (finish_goto_stmt): Surround computed goto argument
	with CLEANUP_POINT_EXPR if needed.

	* g++.dg/ext/label14.C: New test.


	Jakub


--- gcc/cp/semantics.c.jj	2012-06-27 16:36:03.000000000 +0200
+++ gcc/cp/semantics.c	2012-07-02 10:22:26.377925168 +0200
@@ -571,6 +571,9 @@ finish_goto_stmt (tree destination)
 				    tf_warning_or_error);
 	  if (error_operand_p (destination))
 	    return NULL_TREE;
+	  destination
+	    = fold_build_cleanup_point_expr (TREE_TYPE (destination),
+					     destination);
 	}
     }
 
--- gcc/testsuite/g++.dg/ext/label14.C.jj	2012-07-02 10:28:14.305949165 +0200
+++ gcc/testsuite/g++.dg/ext/label14.C	2012-07-02 10:27:11.000000000 +0200
@@ -0,0 +1,17 @@
+// PR c++/53812
+// { dg-do compile }
+// { dg-options "" }
+
+struct T { T () : t(0) {}; int t; ~T (); };
+struct S { void *operator [] (T); };
+void bar (S &, void *, void *);
+
+void
+foo (S &x, T &y)
+{
+  bar (x, &&l1, &&l2);
+l1:
+  goto *x[y];
+l2:
+  bar (x, &&l1, &&l2);
+}