doc: discuss named references after locations.

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index 3ba48db5ea55034fb67541caa77dc8f0adb2b837..7a718a1dd8eef7cb56069d17d6b9846e12d61fb8 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -1,8 +1,8 @@
                                                             -*- Autoconf -*-
 
 # C M4 Macros for Bison.
-# Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009
-# Free Software Foundation, Inc.
+
+# Copyright (C) 2002, 2004-2011 Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -161,7 +161,8 @@ m4_define([b4_int_type_for],
 # --------------------------------------------
 # Without inducing a comparison warning from the compiler, check if the
 # literal value LITERAL equals VALUE from table TABLE, which must have
-# TABLE_min and TABLE_max defined.
+# TABLE_min and TABLE_max defined.  YYID must be defined as an identity
+# function that suppresses warnings about constant conditions.
 m4_define([b4_table_value_equals],
 [m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
                || m4_indir([b4_]$1[_max]) < $3), [1],
@@ -415,6 +416,15 @@ b4_syncline([@oline@], [@ofile@])
     break;])
 
 
+# b4_predicate_case(LABEL, CONDITIONS)
+# ------------------------------------
+m4_define([b4_predicate_case],
+[  case $1:
+    if (! ($2)) YYERROR;
+b4_syncline([@oline@], [@ofile@])
+    break;])
+
+
 # b4_yydestruct_generate(FUNCTION-DECLARATOR)
 # -------------------------------------------
 # Generate the "yydestruct" function, which declaration is issued using