[C++ PATCH] Fix ICE with computed goto (PR c++/53812)

[Jakub Jelinek]

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  <ja...@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.

--- 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);
+}

        Jakub