X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/bba97eb2c13a632c9a23306a834de312df16e4e0..5504898e82be0ce888fff5a28a48530fa156625f:/src/gram.h

diff --git a/src/gram.h b/src/gram.h
index 087583ad..0a92993c 100644
--- 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.
@@ -47,30 +47,31 @@
    Therefore 0 cannot be used, since it would be both the rule number
    0, and the token EOF).
 
-   Actions and guards are accessed via the rule number.
+   Actions are accessed via the rule number.
 
    The rules themselves are described by several arrays: amongst which
    RITEM, and RULES.
 
    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.
@@ -80,11 +81,9 @@
    contains minus R, which identifies it as the end of a portion and
    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
-   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.
+   The portions of RITEM come in order of increasing rule number.
+   NRITEMS is the total length of RITEM.  Each element of RITEM is
+   called an "item" and its index in RITEM is an item number.
 
    Item numbers are used in the finite state machine to represent
    places that parsing can get to.
@@ -103,65 +102,71 @@
 #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;
-extern int nritems;
+#define ITEM_NUMBER_MAX INT_MAX
+typedef int item_number_t;
+extern item_number_t *ritem;
+extern unsigned int nritems;
+
+/* There is weird relationship between item_number_t and
+   token_number_t: we store token_number_t in item_number_t, but in
+   the latter we also store, as negative numbers, the rule numbers.
+
+   Therefore, an token_number_t must be a valid item_number_t, and we
+   sometimes have to perform the converse transformation.  */
+#define token_number_as_item_number(Tok) ((item_number_t) (Tok))
+#define item_number_as_token_number(Ite) ((token_number_t) (Ite))
+
+extern token_number_t start_symbol;
 
-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;
-
-  const char *guard;
-  short guard_line;
+  int action_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.  */
+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
-   parser that provides for semantic error recovery.  If it is zero,
-   the yacc-compatible simplified parser is used.  */
-
-extern int semantic_parser;
 
 /* PURE_PARSER is nonzero if should generate a parser that is all pure
    and reentrant.  */
 
 extern int pure_parser;
 
-/* ERROR_TOKEN_NUMBER is the token number of the error token.  */
-
-extern int error_token_number;
-
 /* Report the length of the RHS. */
 int rule_rhs_length PARAMS ((rule_t *rule));
 
@@ -171,4 +176,10 @@ void ritem_print PARAMS ((FILE *out));
 /* Return the size of the longest rule RHS.  */
 size_t ritem_longest_rhs PARAMS ((void));
 
+/* Dump the grammar. */
+void grammar_dump PARAMS ((FILE *out, const char *title));
+
+/* Free the packed grammar. */
+void grammar_free PARAMS ((void));
+
 #endif /* !GRAM_H_ */