/* 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.
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.
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.
Associativities are recorded similarly in SYMBOLS[I]->assoc. */
+#include "symtab.h"
#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;
-extern int start_symbol;
+/* 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.
-/* Associativity values for tokens and rules. */
-typedef enum
-{
- right_assoc,
- left_assoc,
- non_assoc
-} associativity;
+ 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;
typedef struct rule_s
{
- short lhs;
- short *rhs;
- short prec;
- short precsym;
- associativity assoc;
- short line;
+ /* 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;
+
+ 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));
/* Dump RITEM for traces. */
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_ */
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