-/* 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 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 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
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. 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.
+ 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"
+# 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;
-extern short *ritem;
-extern int nritems;
+typedef int item_number;
+# define ITEM_NUMBER_MAX INT_MAX
+extern item_number *ritem;
+extern unsigned int nritems;
+
+/* 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, a symbol_number must be a valid item_number, and we
+ sometimes have to perform the converse transformation. */
+
+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;
+}
+
+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;
+}
-extern int start_symbol;
+/*--------.
+| Rules. |
+`--------*/
-typedef struct rule_s
+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;
- short *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;
- short line;
+ location location;
bool useful;
+ bool is_predicate;
const char *action;
- short action_line;
+ location action_location;
+} rule;
+
+extern rule *rules;
+
+/* A function that selects a rule. */
+typedef bool (*rule_filter) (rule const *);
+
+/* 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);
+
+/* 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);
+
+/* 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. */
+size_t rule_rhs_length (rule const *r);
+
+/* Print this rule's RHS on OUT. */
+void rule_rhs_print (rule const *r, FILE *out);
+
- const char *guard;
- short guard_line;
-} rule_t;
-extern struct rule_s *rules;
/* Table of the symbols, indexed by the symbol number. */
-extern symbol_t **symbols;
+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. */
-typedef short token_number_t;
-extern token_number_t *token_translations;
+extern symbol_number *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. */
+/* Dump RITEM for traces. */
+void ritem_print (FILE *out);
-extern int pure_parser;
+/* Return the size of the longest rule RHS. */
+size_t ritem_longest_rhs (void);
-/* ERROR_TOKEN_NUMBER is the token number of the error token. */
+/* 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);
-extern int error_token_number;
+/* 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);
-/* Report the length of the RHS. */
-int rule_rhs_length PARAMS ((rule_t *rule));
+/* Dump the grammar. */
+void grammar_dump (FILE *out, const char *title);
-/* Dump RITEM for traces. */
-void ritem_print PARAMS ((FILE *out));
+/* 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);
-/* Return the size of the longest rule RHS. */
-size_t ritem_longest_rhs PARAMS ((void));
+/* Free the packed grammar. */
+void grammar_free (void);
#endif /* !GRAM_H_ */
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