tree.h (TREE_CODE_LENGTH): New macro.

	* tree.h (TREE_CODE_LENGTH): New macro.
	* c-common.c (c_find_base_decl): Use it.
	* expr.c (safe_from_p): Likewise.
	* print-tree.c (print_node): Likewise.
	* tree.c (make_node, copy_node, get_identifier): Likewie.
	(first_rtl_op, contains_placeholder_p, substitute_in_expr): Likewise.
	(build, build_nt, build_parse_node, simple_cst_equal): Likewise.
	* fold-const.c (make_range): Likewise.
	(fold): Likewise; also use first_rtl_op.
	* c-iterate.c (collect_iterators): Use first_rtl_op.
	* calls.c (calls_function_1): Likewise; also rename TYPE to CLASS.
	Use IS_EXPR_CODE_CLASS.
	(preexpand_calls): Likewise.
	* ggc-common.c (ggc_mark_trees): Rework to use first_rtl_op
	and TREE_CODE_LENGTH.
	* stmt.c (warn_if_unused_value): If no operands, no unused value.
	* ch/lang.c (deep_const_expr): Use first_rtl_op.
	* ch/satisfy.c (satisfy): Use TREE_CODE_LENGTH.
	* cp/method.c (mangle_expression): Use TREE_CODE_LENGTH.
	* cp/tree.c (break_out_calls, build_min_nt): Use TREE_CODE_LENGTH.
	(built_min, cp_tree_equal): Likewise.

From-SVN: r34203

1 files changed, 8 insertions, 0 deletions

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 76dcdc3..a1beb46 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -2004,6 +2004,14 @@ warn_if_unused_value (exp)
 	   || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
 	  && TREE_THIS_VOLATILE (exp))
 	return 0;
+
+      /* If this is an expression which has no operands, there is no value
+	 to be unused.  There are no such language-independent codes,
+	 but front ends may define such.  */
+      if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
+	  && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
+	return 0;
+
     warn:
       warning_with_file_and_line (emit_filename, emit_lineno,
 				  "value computed is not used");