re PR c++/45908 ([C++0x] ICE involving decltype: in tree_low_cst, at tree.h:4114)

	PR c++/45908
	* typeck.c (cp_build_addr_expr_1): Add check for incomplete types in
	code folding offsetof-like computations.

From-SVN: r165031

gcc/cp/ChangeLog

+2010-10-06  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR c++/45908
+	* typeck.c (cp_build_addr_expr_1): Add check for incomplete types in
+	code folding offsetof-like computations.
+
 2010-10-05  Nicola Pero  <nicola.pero@meta-innovation.com>
 
 	PR objc++/31125

gcc/cp/typeck.c

@@ -4947,6 +4947,7 @@ cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain)
       && TREE_CODE (argtype) != METHOD_TYPE
       && argtype != unknown_type_node
       && (val = get_base_address (arg))
+      && COMPLETE_TYPE_P (TREE_TYPE (val))
       && TREE_CODE (val) == INDIRECT_REF
       && TREE_CONSTANT (TREE_OPERAND (val, 0)))
     {

gcc/testsuite/ChangeLog

 2010-10-06  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* g++.dg/cpp0x/pr45908.C: New test.
+
+2010-10-06  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gnat.dg/opt6.ad[sb]: New test.
 
 2010-10-06  Nicola Pero  <nicola.pero@meta-innovation.com>

gcc/testsuite/g++.dg/cpp0x/pr45908.C

+// PR c++/45908
+// Testcase by Jonathan Wakely <redi@gcc.gnu.org>
+
+// { dg-do compile }
+// { dg-options "-std=c++0x" }
+
+struct vector {
+    struct iterator { };
+    struct const_iterator { };
+    iterator begin();
+    const_iterator begin() const;
+};
+
+class block {
+    vector v;
+    auto end() const -> decltype(v.begin())
+    { return v.begin(); } // { dg-error "conversion" }
+};