* src/gram.h (item_number_t): New, the type of item numbers in

[bison.git] / src / gram.h

diff --git a/src/gram.h b/src/gram.h
index 087583ade78f0a759d2f53018812a39a98465f64..26682913b5cc3629ec44dcf8084d697581c62d30 100644 (file)
--- a/src/gram.h
+++ b/src/gram.h
@@ -1,5 +1,5 @@
 /* Data definitions for internal representation of bison's input,
-   Copyright 1984, 1986, 1989, 1992, 2001, 2002
+   Copyright (C) 1984, 1986, 1989, 1992, 2001, 2002
    Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
@@ -54,23 +54,24 @@
 
    RULES is an array of struct rule_s, which members are:
 
-   RULES[R].lhs -- the symbol number of the left hand side of rule R.
-   If -1, the rule has been thrown out by reduce.c and should be
-   ignored.
+   RULES[R].lhs -- the symbol of the left hand side of rule R.
 
    RULES[R].rhs -- the index in RITEM of the beginning of the portion
    for rule R.
 
-   RULES[R].prec -- the precedence level of R.
+   RULES[R].prec -- the symbol providing the precedence level of R.
 
-   RULES[R].precsym -- the symbol-number of the symbol in %prec for R
-   (if any).
+   RULES[R].precsym -- the symbol attached (via %prec) to give its
+   precedence to R.  Of course, if set, it is equal to `prec', but we
+   need to distinguish one from the other when reducing: a symbol used
+   in a %prec is not useless.
 
    RULES[R].assoc -- the associativity of R.
 
    RULES[R].line -- the line where R was defined.
 
-   RULES[R].useful -- TRUE iff the rule is used.
+   RULES[R].useful -- TRUE iff the rule is used (i.e., FALSE if thrown
+   away by reduce).
 
    The right hand side is stored as symbol numbers in a portion of
    RITEM.
@@ -81,7 +82,7 @@
    says which rule it is for.
 
    The portions of RITEM come in order of increasing rule number and
-   are followed by an element which is zero to mark the end.  nitems
+   are followed by an element which is zero to mark the end.  nritems
    is the total length of ritem, not counting the final zero.  Each
    element of RITEM is called an "item" and its index in RITEM is an
    item number.
@@ -103,48 +104,58 @@
 #define        ISTOKEN(s)      ((s) < ntokens)
 #define        ISVAR(s)        ((s) >= ntokens)
 
-extern int nitems;
 extern int nrules;
 extern int nsyms;
 extern int ntokens;
 extern int nvars;
 
-extern short *ritem;
+#define ITEM_NUMBER_MAX INT_MAX
+typedef int item_number_t;
+extern item_number_t *ritem;
 extern int nritems;
 
 extern int start_symbol;
 
+
 typedef struct rule_s
 {
   /* The number of the rule in the source.  It is usually the index in
      RULES too, except if there are useless rules.  */
+  short user_number;
+
+  /* The index in RULES.  Usually the rule number in the source,
+     except if some rules are useless.  */
   short number;
 
-  bucket *lhs;
-  short *rhs;
-  short prec;
-  short precsym;
-  associativity assoc;
-  short line;
+  symbol_t *lhs;
+  item_number_t *rhs;
+
+  /* This symbol provides both the associativity, and the precedence. */
+  symbol_t *prec;
+
+  /* This symbol was attached to the rule via %prec. */
+  symbol_t *precsym;
+
+  int line;
   bool useful;
 
   const char *action;
-  short action_line;
+  int action_line;
 
   const char *guard;
-  short guard_line;
+  int guard_line;
 } rule_t;
 
 extern struct rule_s *rules;
 
 /* Table of the symbols, indexed by the symbol number. */
-extern struct bucket **symbols;
-
-/* token translation table: indexed by a token number as returned by
-   the user's yylex routine, it yields the internal token number used
-   by the parser and throughout bison.  */
+extern symbol_t **symbols;
 
-extern short *token_translations;
+/* TOKEN_TRANSLATION -- a table indexed by a token number as returned
+   by the user's yylex routine, it yields the internal token number
+   used by the parser and throughout bison.  */
+typedef short token_number_t;
+extern token_number_t *token_translations;
 extern int max_user_token_number;
 
 /* SEMANTIC_PARSER is nonzero if the input file says to use the hairy