parser: use %empty

[bison.git] / src / symtab.h

diff --git a/src/symtab.h b/src/symtab.h
index 9377800801e4d6bc793e6e622545de7d616a1e9a..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.
@@ -46,7 +46,7 @@ typedef enum
 
 /** Internal token numbers. */
 typedef int symbol_number;
-#define SYMBOL_NUMBER_MAXIMUM INT_MAX
+# define SYMBOL_NUMBER_MAXIMUM INT_MAX
 
 
 typedef struct symbol symbol;
@@ -54,13 +54,12 @@ typedef struct symbol symbol;
 /* Declaration status of a symbol.
 
    First, it is "undeclared".  Then, if "undeclared" and used in a
-   %printer/%destructor, it is "used".  If not "declared" by used in a
-   rule, it is "needed".  Finally, if declared (via a rule for
-   nonterminals, or %oken), it is "declared".
+   %printer/%destructor, it is "used".  If not "declared" but used in
+   a rule, it is "needed".  Finally, if declared (via a rule for
+   nonterminals, or %token), it is "declared".
 
    When status are checked at the end, "declared" symbols are fine,
-   "used" symbols trigger warnings, otherwise it's an error.
-*/
+   "used" symbols trigger warnings, otherwise it's an error.  */
 
 typedef enum
   {
@@ -92,8 +91,14 @@ struct symbol
   /** The location of its first occurrence.  */
   location location;
 
-  /** Its \c \%type.  */
+  /** Its \c \%type.
+
+      Beware that this is the type_name as was entered by the user,
+      including silly things such as "]" if she entered "%token <]> t".
+      Therefore, when outputting type_name to M4, be sure to escape it
+      into "@}".  See quoted_output for instance.  */
   uniqstr type_name;
+
   /** Its \c \%type's location.  */
   location type_location;
 
@@ -101,9 +106,9 @@ struct symbol
       symbol.
 
       Access this field only through <tt>symbol</tt>'s interface functions. For
-      Example, if <tt>symbol::destructor = NULL</tt> (resp. <tt>symbol::printer
+      example, if <tt>symbol::destructor = NULL</tt> (resp. <tt>symbol::printer
       = NULL</tt>), a default \c \%destructor (resp. \%printer) or a per-type
-      \c symbol_destructor_printer_get will compute the corect one. */
+      \c symbol_destructor_printer_get will compute the correct one. */
   code_props props[CODE_PROPS_SIZE];
 
   symbol_number number;
@@ -121,16 +126,16 @@ struct symbol
 };
 
 /** Undefined user number.  */
-#define USER_NUMBER_UNDEFINED -1
+# define USER_NUMBER_UNDEFINED -1
 
 /* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
    this symbol has a literal string alias.  For instance, `%token foo
    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
    USER_NUMBER_HAS_STRING_ALIAS.  */
-#define USER_NUMBER_HAS_STRING_ALIAS -9991
+# define USER_NUMBER_HAS_STRING_ALIAS -9991
 
 /* Undefined internal token number.  */
-#define NUMBER_UNDEFINED (-1)
+# define NUMBER_UNDEFINED (-1)
 
 /** Fetch (or create) the symbol associated to KEY.  */
 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
@@ -219,6 +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.  |
 `-----------------*/