re PR middle-end/40502 (crash in cp_diagnostic_starter)

	PR c++/40502
	* error.c (cp_print_error_function): Check for NULL block.

	* g++.dg/ext/strncpy-chk1.C: New test.

From-SVN: r149470

gcc/cp/ChangeLog

+2009-07-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/40502
+	* error.c (cp_print_error_function): Check for NULL block.
+
 2008-07-09  Simon Martin  <simartin@users.sourceforge.net>
-	Jason Merrill  <jason@redhat.com>
+	    Jason Merrill  <jason@redhat.com>
 
 	* pt.c (perform_typedefs_access_check, get_types_needing_access_check,
 	append_type_to_template_for_access_check_1): Use CLASS_TYPE_P.

gcc/cp/error.c

@@ -2603,7 +2603,7 @@ cp_print_error_function (diagnostic_context *context,
 		  while (block && TREE_CODE (block) == BLOCK)
 		    block = BLOCK_SUPERCONTEXT (block);
 
-		  if (TREE_CODE (block) == FUNCTION_DECL)
+		  if (block && TREE_CODE (block) == FUNCTION_DECL)
 		    fndecl = block;
 		  abstract_origin = NULL;
 		}

gcc/testsuite/ChangeLog

+2009-07-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/40502
+	* g++.dg/ext/strncpy-chk1.C: New test.
+
 2009-07-10  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/40496

gcc/testsuite/g++.dg/ext/strncpy-chk1.C

+// PR c++/40502
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct A { char x[12], y[35]; };
+struct B { char z[50]; };
+
+inline void
+foo (char *dest, const char *__restrict src, __SIZE_TYPE__ n)
+{
+  __builtin___strncpy_chk (dest, src, n, __builtin_object_size (dest, 0));	// { dg-warning "will always overflow" }
+}
+
+void bar (const char *, int);
+
+inline void
+baz (int i)
+{
+  char s[128], t[32];
+  bar (s, 0);
+  bar (t, i);
+  A a;
+  B b;
+  foo (a.y, b.z, 36);
+}
+
+void
+test ()
+{
+  baz (0);
+}