build: look for Perl in configure.

[bison.git] / src / gram.h

diff --git a/src/gram.h b/src/gram.h
index d02964ffb825be190a218021d1ba655b8230f87f..3f75dd8f951a9e3ed71397f65c2e181602c08d4e 100644 (file)
--- a/src/gram.h
+++ b/src/gram.h
@@ -1,23 +1,22 @@
-/* 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, 2009-2012 Free
+   Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    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
    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
    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_
 
 #ifndef GRAM_H_
 # define GRAM_H_


@@ -36,23 +35,23 @@
 
    The rules receive rule numbers 1 to NRULES in the order they are
    written.  More precisely Bison augments the grammar with the
 
    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
 
    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.
 
 
    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].lhs -- the symbol of the left hand side of rule R.
 


@@ -68,9 +67,15 @@
 
    RULES[R].assoc -- the associativity of R.
 
 
    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].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
    away by reduce).
 
    The right hand side is stored as symbol numbers in a portion of


@@ -81,11 +86,9 @@
    contains minus R, which identifies it as the end of a portion and
    says which rule it is for.
 
    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.
 
    Item numbers are used in the finite state machine to represent
    places that parsing can get to.


@@ -99,86 +102,174 @@
 
    Associativities are recorded similarly in SYMBOLS[I]->assoc.  */
 
 
    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 int nsyms;
 extern int ntokens;
 extern int nvars;
 

+typedef int item_number;

 #define ITEM_NUMBER_MAX INT_MAX
 #define ITEM_NUMBER_MAX INT_MAX

-typedef int item_number_t;
-extern item_number_t *ritem;
-extern int nritems;
+extern item_number *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.
+/* 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 token_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.  */
    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;
+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.  */
 {
   /* 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.  */
 
   /* 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. */
 
   /* 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. */
 
   /* This symbol was attached to the rule via %prec. */

-  symbol_t *precsym;
+  symbol *precsym;

 
 

-  int line;
+  location location;

   bool useful;
 
   const char *action;
   bool useful;
 
   const char *action;

-  int action_line;
-} rule_t;
+  location action_location;
+} rule;
+
+extern rule *rules;
+
+/* A function that selects a rule.  */
+typedef bool (*rule_filter) (rule *);
+
+/* 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 *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 *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 *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 *r, symbol *previous_lhs, FILE *out);
+void rule_lhs_print_xml (rule *r, FILE *out, int level);
+
+/* Return the length of the RHS.  */
+int rule_rhs_length (rule *r);
+
+/* Print this rule's RHS on OUT.  */
+void rule_rhs_print (rule *r, FILE *out);
+
+/* Print this rule on OUT.  */
+void rule_print (rule *r, FILE *out);
+
+

 
 

-extern struct rule_s *rules;

 
 /* Table of the symbols, indexed by the symbol number. */
 
 /* 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.  */
 
 /* 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 symbol_number *token_translations;

 extern int max_user_token_number;
 
 
 extern int max_user_token_number;
 
 

-/* PURE_PARSER is nonzero if should generate a parser that is all pure
-   and reentrant.  */
-
-extern int pure_parser;
-
-/* Report the length of the RHS. */
-int rule_rhs_length PARAMS ((rule_t *rule));

 
 /* Dump RITEM for traces. */
 
 /* Dump RITEM for traces. */

-void ritem_print PARAMS ((FILE *out));
+void ritem_print (FILE *out);

 
 /* Return the size of the longest rule RHS.  */
 
 /* 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 that match FILTER on OUT under TITLE.  */
+void grammar_rules_partial_print (FILE *out, const char *title,
+                                 rule_filter filter);
+
+/* 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. */
 
 /* 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 (void);

 
 #endif /* !GRAM_H_ */
 
 #endif /* !GRAM_H_ */