re PR c++/31513 (Miscompilation of Function Passing Bit Field Value to Function)

	PR c++/31513
	* call.c (convert_for_arg_passing): Convert bitfields to their
	declared types.

	PR c++/31513
	* g++.dg/expr/bitfield8.C: New test.

From-SVN: r123939

gcc/cp/ChangeLog

+2007-04-17  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/31513
+	* call.c (convert_for_arg_passing): Convert bitfields to their
+	declared types.
+
 2007-04-17  Simon Martin  <simartin@users.sourceforge.net>
 
 	PR c++/31517

gcc/cp/call.c

@@ -4713,6 +4713,7 @@ type_passed_as (tree type)
 tree
 convert_for_arg_passing (tree type, tree val)
 {
+  val = convert_bitfield_to_declared_type (val);
   if (val == error_mark_node)
     ;
   /* Pass classes with copy ctors by invisible reference.  */

gcc/testsuite/ChangeLog

+2007-04-17  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/31513
+	* g++.dg/expr/bitfield8.C: New test.
+
 2007-04-17  Joseph Myers  <joseph@codesourcery.com>
             Richard Sandiford  <richard@codesourcery.com>
 

gcc/testsuite/g++.dg/expr/bitfield8.C

+// PR c++/31513
+// { dg-do run }
+
+extern "C" void abort();
+
+struct tree_type {
+  unsigned int precision : 9;
+};
+
+void bork(unsigned int i) {
+  if (i != 7)
+    abort();
+}
+
+void foo(struct tree_type *t)
+{
+  bork(t->precision);
+}
+
+int main() {
+  tree_type t;
+  t.precision = 7;
+  foo(&t);
+}