[PATCH] fix c++/47589 - backport to 4.4 branch

[Jonathan Wakely]

this patch fixes PR c++/47589 (a 4.3/4.4 ice-on-valid-code regression)
by backporting Jakub's fix for c++/45894, which was caused by the same
problem but only manifested with -std=c++0x -Wsequence-point

Jakub's new test doesn't compile on the 4.4 branch, so this adds a new
test reduced from the original reproducer attached to c++/47589

Tested x86_64-linux, OK for 4.4?

==> cp/ChangeLog <==
2011-02-02  Jonathan Wakely  <jwakely.gcc@gmail.com>

        PR c++/47589
        Backport from mainline
        2010-11-09  Jakub Jelinek  <jakub@redhat.com>

        PR c++/45894
        * tree.c (lvalue_kind): Don't crash if ref has NULL type.

==> testsuite/ChangeLog <==
2011-02-02  Jonathan Wakely  <jwakely.gcc@gmail.com>

        PR c++/47589
        * g++.dg/pr47589.C: New test.


Should I also check the new test into the 4.5 branch and trunk to
avoid future regressions?
-------------- next part --------------
Index: cp/tree.c
===================================================================
--- cp/tree.c	(revision 169769)
+++ cp/tree.c	(working copy)
@@ -72,7 +72,8 @@ lvalue_p_1 (tree ref)
 	  == REFERENCE_TYPE)
     return lvalue_p_1 (TREE_OPERAND (ref, 0));
 
-  if (TREE_CODE (TREE_TYPE (ref)) == REFERENCE_TYPE)
+  if (TREE_TYPE (ref)
+      && TREE_CODE (TREE_TYPE (ref)) == REFERENCE_TYPE)
     {
       /* unnamed rvalue references are rvalues */
       if (TYPE_REF_IS_RVALUE (TREE_TYPE (ref))
Index: testsuite/g++.dg/pr47589.C
===================================================================
--- testsuite/g++.dg/pr47589.C	(revision 0)
+++ testsuite/g++.dg/pr47589.C	(revision 0)
@@ -0,0 +1,26 @@
+// PR c++/47589
+// { dg-do compile }
+
+struct F
+{
+    typedef void(*Cb)();
+
+    F(Cb);
+};
+
+struct C
+{
+    template<class D> static void f();
+};
+
+template<class D>
+struct TF : F
+{
+    TF() : F(C::f<D>) { }
+};
+
+struct DTC : TF<DTC>
+{
+    DTC() { }
+};
+