parser: use %empty

[bison.git] / src / symtab.h

diff --git a/src/symtab.h b/src/symtab.h
index a01db247ceff507ec10b32afe476134f402bbcb2..f585fd7b91b47ce22567254c405f09312e0c5f34 100644 (file)
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -1,6 +1,6 @@
 /* Definitions for symtab.c and callers, part of Bison.
 
-   Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2012 Free Software
+   Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2013 Free Software
    Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
@@ -224,6 +224,59 @@ extern symbol *startsymbol;
 extern location startsymbol_location;
 
 
+
+/*-------------------.
+| Symbol Relations.  |
+`-------------------*/
+
+/* The symbol relations are represented by a directed graph. */
+
+/* The id of a node */
+typedef int graphid;
+
+typedef struct symgraphlink symgraphlink;
+
+struct symgraphlink
+{
+  /** The second \c symbol or group of a precedence relation.
+   * See \c symgraph. */
+  graphid id;
+
+  symgraphlink *next;
+};
+
+/* Symbol precedence graph, to store the used precedence relations between
+ * symbols. */
+
+typedef struct symgraph symgraph;
+
+struct symgraph
+{
+  /** Identifier for the node: equal to the number of the symbol. */
+  graphid id;
+
+  /** The list of related symbols that have a smaller precedence. */
+  symgraphlink *succ;
+
+  /** The list of related symbols that have a greater precedence. */
+  symgraphlink *pred;
+};
+
+/** Register a new precedence relation as used. */
+
+void register_precedence (graphid first, graphid snd);
+
+/** Print a warning for each symbol whose precedence and/or associativity
+ * is useless. */
+
+void print_precedence_warnings (void);
+
+/*----------------------.
+| Symbol associativity  |
+`----------------------*/
+
+void register_assoc (graphid i, graphid j);
+
 /*-----------------.
 | Semantic types.  |
 `-----------------*/