-/* Data definitions for internal representation of bison's input,
- Copyright (C) 1984, 1986, 1989, 1992, 2001, 2002
- Free Software Foundation, Inc.
+/* Data definitions for internal representation of Bison's input.
+
+ Copyright (C) 1984, 1986, 1989, 1992, 2001-2007, 2009-2013 Free
+ Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
- Bison is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- Bison is distributed in the hope that it will be useful,
+ This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with Bison; see the file COPYING. If not, write to
- the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef GRAM_H_
# define GRAM_H_
The rules receive rule numbers 1 to NRULES in the order they are
written. More precisely Bison augments the grammar with the
- initial rule, `$axiom: START-SYMBOL EOF', which is numbered 1, all
- the user rules are 2, 3 etc. Each time a rule number is presented
- to the user, we subtract 1, so *displayed* rule numbers are 0, 1,
- 2...
+ initial rule, '$accept: START-SYMBOL $end', which is numbered 1,
+ all the user rules are 2, 3 etc. Each time a rule number is
+ presented to the user, we subtract 1, so *displayed* rule numbers
+ are 0, 1, 2...
Internally, we cannot use the number 0 for a rule because for
instance RITEM stores both symbol (the RHS) and rule numbers: the
symbols are shorts >= 0, and rule number are stored negative.
Therefore 0 cannot be used, since it would be both the rule number
- 0, and the token EOF).
+ 0, and the token $end).
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 is an array of rules, whose members are:
RULES[R].lhs -- the symbol of the left hand side of rule R.
RULES[R].prec -- the symbol providing the precedence level of R.
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
+ 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].dprec -- the dynamic precedence level of R (for GLR
+ parsing).
+
+ RULES[R].merger -- index of merging function for R (for GLR
+ parsing).
+
RULES[R].line -- the line where R was defined.
- RULES[R].useful -- TRUE iff the rule is used (i.e., FALSE if thrown
+ 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
# include "location.h"
# include "symtab.h"
-# define ISTOKEN(s) ((s) < ntokens)
-# define ISVAR(s) ((s) >= ntokens)
+# define ISTOKEN(i) ((i) < ntokens)
+# define ISVAR(i) ((i) >= ntokens)
-extern int nrules;
extern int nsyms;
extern int ntokens;
extern int nvars;
+typedef int item_number;
# define ITEM_NUMBER_MAX INT_MAX
-typedef int item_number_t;
-extern item_number_t *ritem;
+extern item_number *ritem;
extern unsigned int nritems;
-/* There is weird relationship between item_number_t and
- symbol_number_t: we store symbol_number_t in item_number_t, but in
- the latter we also store, as negative numbers, the rule numbers.
+/* There is weird relationship between OT1H item_number and OTOH
+ symbol_number and rule_number: we store the latter in
+ item_number. symbol_number values are stored as-is, while
+ the negation of (rule_number + 1) is stored.
- Therefore, an symbol_number_t must be a valid item_number_t, and we
+ Therefore, a symbol_number must be a valid item_number, and we
sometimes have to perform the converse transformation. */
-# define symbol_number_as_item_number(Tok) ((item_number_t) (Tok))
-# define item_number_as_symbol_number(Ite) ((symbol_number_t) (Ite))
-extern symbol_number_t start_symbol;
+static inline item_number
+symbol_number_as_item_number (symbol_number sym)
+{
+ return sym;
+}
+static inline symbol_number
+item_number_as_symbol_number (item_number i)
+{
+ return i;
+}
-typedef struct rule_s
+static inline bool
+item_number_is_symbol_number (item_number i)
+{
+ return i >= 0;
+}
+
+/* Rule numbers. */
+typedef int rule_number;
+# define RULE_NUMBER_MAX INT_MAX
+extern rule_number nrules;
+
+static inline item_number
+rule_number_as_item_number (rule_number r)
+{
+ return -1 - r;
+}
+
+static inline rule_number
+item_number_as_rule_number (item_number i)
+{
+ return -1 - i;
+}
+
+static inline bool
+item_number_is_rule_number (item_number i)
+{
+ return i < 0;
+}
+
+/*--------.
+| Rules. |
+`--------*/
+
+typedef struct
{
/* 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;
+ rule_number user_number;
/* The index in RULES. Usually the rule number in the source,
except if some rules are useless. */
- short number;
+ rule_number number;
- symbol_t *lhs;
- item_number_t *rhs;
+ symbol *lhs;
+ item_number *rhs;
/* This symbol provides both the associativity, and the precedence. */
- symbol_t *prec;
+ symbol *prec;
+
+ int dprec;
+ int merger;
/* This symbol was attached to the rule via %prec. */
- symbol_t *precsym;
+ symbol *precsym;
- location_t location;
+ location location;
bool useful;
+ bool is_predicate;
const char *action;
- location_t action_location;
-} rule_t;
+ location action_location;
+} rule;
-extern struct rule_s *rules;
+extern rule *rules;
-/* Table of the symbols, indexed by the symbol number. */
-extern symbol_t **symbols;
+/* A function that selects a rule. */
+typedef bool (*rule_filter) (rule const *);
-/* 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 symbol_number_t *token_translations;
-extern int max_user_token_number;
+/* Return true IFF the rule has a 'number' smaller than NRULES. That is, it is
+ useful in the grammar. */
+bool rule_useful_in_grammar_p (rule const *r);
+/* Return true IFF the rule has a 'number' higher than NRULES. That is, it is
+ useless in the grammar. */
+bool rule_useless_in_grammar_p (rule const *r);
-/* PURE_PARSER is nonzero if should generate a parser that is all pure
- and reentrant. */
+/* Return true IFF the rule is not flagged as useful but is useful in the
+ grammar. In other words, it was discarded because of conflicts. */
+bool rule_useless_in_parser_p (rule const *r);
-extern int pure_parser;
+/* Print this rule's number and lhs on OUT. If a PREVIOUS_LHS was
+ already displayed (by a previous call for another rule), avoid
+ useless repetitions. */
+void rule_lhs_print (rule const *r, symbol const *previous_lhs, FILE *out);
+void rule_lhs_print_xml (rule const *r, FILE *out, int level);
/* Return the length of the RHS. */
-int rule_rhs_length PARAMS ((rule_t *rule));
+size_t rule_rhs_length (rule const *r);
+
+/* Print this rule's RHS on OUT. */
+void rule_rhs_print (rule const *r, FILE *out);
+
+
+
+
+/* Table of the symbols, indexed by the symbol number. */
+extern symbol **symbols;
+
+/* 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 symbol_number *token_translations;
+extern int max_user_token_number;
-/* Print this RULE's RHS on OUT. */
-void rule_rhs_print PARAMS ((rule_t *rule, FILE *out));
-/* Print this RULE on OUT. */
-void rule_print PARAMS ((rule_t *rule, FILE *out));
/* Dump RITEM for traces. */
-void ritem_print PARAMS ((FILE *out));
+void ritem_print (FILE *out);
/* Return the size of the longest rule RHS. */
-size_t ritem_longest_rhs PARAMS ((void));
+size_t ritem_longest_rhs (void);
-/* Print the grammar's rules numbers from BEGIN (inclusive) to END
- (exclusive) on OUT under TITLE. */
-void grammar_rules_partial_print PARAMS ((FILE *out, const char *title,
- int begin, int end));
+/* Print the grammar's rules that match FILTER on OUT under TITLE. */
+void grammar_rules_partial_print (FILE *out, const char *title,
+ rule_filter filter);
-/* Print the grammar's rules on OUT. */
-void grammar_rules_print PARAMS ((FILE *out));
+/* Print the grammar's useful rules on OUT. */
+void grammar_rules_print (FILE *out);
+/* Print all of the grammar's rules with a "usefulness" attribute. */
+void grammar_rules_print_xml (FILE *out, int level);
/* Dump the grammar. */
-void grammar_dump PARAMS ((FILE *out, const char *title));
+void grammar_dump (FILE *out, const char *title);
+
+/* Report on STDERR the rules that are not flagged USEFUL, using the
+ MESSAGE (which can be 'rule useless in grammar' when invoked after grammar
+ reduction, or 'rule useless in parser due to conflicts' after conflicts
+ were taken into account). */
+void grammar_rules_useless_report (const char *message);
/* Free the packed grammar. */
-void grammar_free PARAMS ((void));
+void grammar_free (void);
#endif /* !GRAM_H_ */
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