re PR c++/44362 (Bogus set-but-not-used warning)

	PR c++/44362
	* call.c (build_conditional_expr): If both arg2 and arg3 are lvalues
	with the same type, call mark_lvalue_use on both.

	* c-c++-common/Wunused-var-10.c: New test.

Co-Authored-By: Jason Merrill <jason@redhat.com>

From-SVN: r160289

gcc/cp/ChangeLog

+2010-06-04  Jakub Jelinek  <jakub@redhat.com>
+	    Jason Merrill  <jason@redhat.com>
+
+	PR c++/44362
+	* call.c (build_conditional_expr): If both arg2 and arg3 are lvalues
+	with the same type, call mark_lvalue_use on both.
+
 2010-06-03  Nathan Froyd  <froydnj@codesourcery.com>
 
 	* class.c (struct vtbl_init_data_s): Remove last_init field.

gcc/cp/call.c

@@ -3839,6 +3839,8 @@ build_conditional_expr (tree arg1, tree arg2, tree arg3,
       && same_type_p (arg2_type, arg3_type))
     {
       result_type = arg2_type;
+      mark_lvalue_use (arg2);
+      mark_lvalue_use (arg3);
       goto valid_operands;
     }
 

gcc/testsuite/ChangeLog

+2010-06-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/44362
+	* c-c++-common/Wunused-var-10.c: New test.
+
 2010-06-04  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR c/25880

gcc/testsuite/c-c++-common/Wunused-var-10.c

+/* PR c++/44362 */
+/* { dg-options "-Wunused" } */
+/* { dg-do compile } */
+
+int
+f1 (int u, int v)
+{
+  int a, b, c, d, e, f, g, h, i;
+  a = u;
+  b = v;
+  c = u;
+  d = v;
+  e = u;
+  f = v;
+  g = u == 6 ? a : b;
+  h = 0 ? c : d;
+  i = 1 ? e : f;
+  return g + h + i;
+}
+
+int
+f2 (int u, int v)
+{
+  int a, b, c, d, e, f, g, h, i;
+  a = u;
+  b = v;
+  c = u;
+  d = v;
+  e = u;
+  f = v;
+  g = u == 6 ? a + 1 : b;
+  h = 0 ? c + 1 : d;
+  i = 1 ? e + 1 : f;
+  return g + h + i;
+}
+
+int
+f3 (int u, int v)
+{
+  int a, b, c, d, e, f, g, h, i;
+  a = u;
+  b = v;
+  c = u;
+  d = v;
+  e = u;
+  f = v;
+  g = u == 6 ? a : b + 1;
+  h = 0 ? c : d + 1;
+  i = 1 ? e : f + 1;
+  return g + h + i;
+}
+
+int
+f4 (int u, int v)
+{
+  int a, c, e, g, h, i;
+  long b, d, f;
+  a = u;
+  b = v;
+  c = u;
+  d = v;
+  e = u;
+  f = v;
+  g = u == 6 ? a : b;
+  h = 0 ? c : d;
+  i = 1 ? e : f;
+  return g + h + i;
+}