call.c (build_over_call): Set TREE_NO_UNUSED_WARNING too.

	* call.c (build_over_call): Set TREE_NO_UNUSED_WARNING too.
	* cvt.c (convert_to_void): Preserve TREE_NO_UNUSED_WARNING.

	* g++.dg/warn/Wunused-1.C: New test.

From-SVN: r50770

gcc/cp/ChangeLog

+2002-03-14  Jakub Jelinek  <jakub@redhat.com>
+
+	* call.c (build_over_call): Set TREE_NO_UNUSED_WARNING too.
+	* cvt.c (convert_to_void): Preserve TREE_NO_UNUSED_WARNING.
+
 2002-03-12  Richard Sandiford  <rsandifo@redhat.com>
 
 	* mangle.c (write_builtin_type): Handle 128-bit integers even if

gcc/cp/call.c

@@ -4305,6 +4305,7 @@ build_over_call (cand, args, flags)
 	     Ideally, the notions of having side-effects and of being
 	     useless would be orthogonal.  */
 	  TREE_SIDE_EFFECTS (val) = 1;
+	  TREE_NO_UNUSED_WARNING (val) = 1;
 	}
       else
 	val = build (MODIFY_EXPR, TREE_TYPE (to), to, arg);

gcc/cp/cvt.c

@@ -852,6 +852,7 @@ convert_to_void (expr, implicit)
 	    tree t = build (COMPOUND_EXPR, TREE_TYPE (new_op1),
 			    TREE_OPERAND (expr, 0), new_op1);
 	    TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
+	    TREE_NO_UNUSED_WARNING (t) = TREE_NO_UNUSED_WARNING (expr);
 	    expr = t;
 	  }
 

gcc/testsuite/ChangeLog

+2002-03-14  Jakub Jelinek  <jakub@redhat.com>
+
+	* g++.dg/warn/Wunused-1.C: New test.
+
 2002-02-13  Richard Sandiford  <rsandifo@redhat.com>
 
 	* g++.dg/abi/mangle6.C: New test.

gcc/testsuite/g++.dg/warn/Wunused-1.C

+// Test whether -Wunused handles empty classes the same as non-empty.
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+struct A {};
+struct B { char c; };
+
+void foo ()
+{
+  struct A a0, a1;
+  struct B b0, b1 = { 25 };
+
+  a0 = a1;	// { dg-bogus "value computed is not used" }
+  b0 = b1;
+}