X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/640748eecf67130c80b5fd5f5cca19630eddf2b3..93d133c932a4f754172cd8473bfe469975b00023:/src/state.h

diff --git a/src/state.h b/src/state.h
index 32559cef..dfdc49d3 100644
--- a/src/state.h
+++ b/src/state.h
@@ -1,22 +1,22 @@
-/* Type definitions for nondeterministic finite state machine for bison,
-   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
+/* Type definitions for the finite state machine for Bison.
+
+   Copyright (C) 1984, 1989, 2000-2004, 2007, 2009-2012 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/>.  */
 
 
 /* These type definitions are used to represent a nondeterministic
@@ -42,7 +42,7 @@
    ACCESSING_SYMBOL of the core.
 
    Each core contains a vector of NITEMS items which are the indices
-   in the RITEMS vector of the items that are selected in this state.
+   in the RITEM vector of the items that are selected in this state.
 
    The two types of actions are shifts/gotos (push the lookahead token
    and read another/goto to the state designated by a nterm) and
@@ -51,7 +51,7 @@
    lookahead token alone).  When the states are generated, these
    actions are represented in two other lists.
 
-   Each transition_t structure describes the possible transitions out
+   Each transition structure describes the possible transitions out
    of one state, the state whose number is in the number field.  Each
    contains a vector of numbers of the states that transitions can go
    to.  The accessing_symbol fields of those states' cores say what
@@ -61,9 +61,8 @@
    deletes transitions by having them point to zero.
 
    Each reductions structure describes the possible reductions at the
-   state whose number is in the number field.  The data is a list of
-   nreds rules, represented by their rule numbers.  first_reduction
-   points to the list of these structures.
+   state whose number is in the number field.  rules is an array of
+   num rules.  lookahead_tokens is an array of bitsets, one per rule.
 
    Conflict resolution can decide that certain tokens in certain
    states should explicitly be errors (for implementing %nonassoc).
@@ -82,31 +81,38 @@
 #ifndef STATE_H_
 # define STATE_H_
 
-# include "bitsetv.h"
+# include <bitset.h>
+
+# include "gram.h"
+# include "symtab.h"
 
 
 /*-------------------.
 | Numbering states.  |
 `-------------------*/
 
-typedef short state_number_t;
-# define STATE_NUMBER_MAX ((state_number_t) SHRT_MAX)
+typedef int state_number;
+# define STATE_NUMBER_MAXIMUM INT_MAX
 
-/* Be ready to map a state_number_t to an int.  */
-# define state_number_as_int(Tok) ((int) (Tok))
+/* Be ready to map a state_number to an int.  */
+static inline int
+state_number_as_int (state_number s)
+{
+  return s;
+}
 
 
-typedef struct state_s state_t;
+typedef struct state state;
 
 /*--------------.
 | Transitions.  |
 `--------------*/
 
-typedef struct transtion_s
+typedef struct
 {
-  short num;
-  state_t *states[1];
-} transitions_t;
+  int num;
+  state *states[1];
+} transitions;
 
 
 /* What is the symbol labelling the transition to
@@ -151,112 +157,118 @@ typedef struct transtion_s
     if (!TRANSITION_IS_DISABLED (Transitions, Iter))
 
 
-/* Return the state such these TRANSITIONS contain a shift/goto to it on
-   SYMBOL.  Aborts if none found.  */
-struct state_s;
-struct state_s *transitions_to PARAMS ((transitions_t *state,
-					symbol_number_t s));
+/* Return the state such SHIFTS contain a shift/goto to it on SYM.
+   Abort if none found.  */
+struct state *transitions_to (transitions *shifts, symbol_number sym);
 
 
 /*-------.
 | Errs.  |
 `-------*/
 
-typedef struct errs_s
+typedef struct
 {
-  short num;
-  symbol_t *symbols[1];
-} errs_t;
+  int num;
+  symbol *symbols[1];
+} errs;
 
-errs_t *errs_new PARAMS ((int num, symbol_t **tokens));
+errs *errs_new (int num, symbol **tokens);
 
 
 /*-------------.
 | Reductions.  |
 `-------------*/
 
-typedef struct reductions_s
+typedef struct
 {
-  short num;
-  rule_t *rules[1];
-} reductions_t;
+  int num;
+  bitset *lookahead_tokens;
+  /* Sorted ascendingly on rule number.  */
+  rule *rules[1];
+} reductions;
 
 
 
 /*---------.
-| States.  |
+| states.  |
 `---------*/
 
-struct state_s
-{
-  state_number_t number;
-  symbol_number_t accessing_symbol;
-  transitions_t     *transitions;
-  reductions_t *reductions;
-  errs_t       *errs;
+struct state_list;
 
-  /* Nonzero if no lookahead is needed to decide what to do in state S.  */
+struct state
+{
+  state_number number;
+  symbol_number accessing_symbol;
+  transitions *transitions;
+  reductions *reductions;
+  errs *errs;
+
+  /* When an includer (such as ielr.c) needs to store states in a list, the
+     includer can define struct state_list as the list node structure and can
+     store in this member a reference to the node containing each state.  */
+  struct state_list *state_list;
+
+  /* If non-zero, then no lookahead sets on reduce actions are needed to
+     decide what to do in state S.  */
   char consistent;
 
-  /* Used in LALR, not LR(0).
-
-     When a state is not consistent (there is an S/R or R/R conflict),
-     lookaheads are needed to enable the reductions.  NLOOKAHEADS is
-     the number of lookahead guarded reductions of the
-     LOOKAHEADS_RULE.  For each rule LOOKAHEADS_RULE[R], LOOKAHEADS[R]
-     is the bitset of the lookaheads enabling this reduction.  */
-  int nlookaheads;
-  bitsetv lookaheads;
-  rule_t **lookaheads_rule;
-
   /* If some conflicts were solved thanks to precedence/associativity,
      a human readable description of the resolution.  */
   const char *solved_conflicts;
+  const char *solved_conflicts_xml;
 
-  /* Its items.  Must be last, since ITEMS can be arbitrarily large.
-     */
-  unsigned short nitems;
-  item_number_t items[1];
+  /* Its items.  Must be last, since ITEMS can be arbitrarily large.  Sorted
+     ascendingly on item index in RITEM, which is sorted on rule number.  */
+  size_t nitems;
+  item_number items[1];
 };
 
-extern state_number_t nstates;
-extern state_t *final_state;
+extern state_number nstates;
+extern state *final_state;
 
 /* Create a new state with ACCESSING_SYMBOL for those items.  */
-state_t *state_new PARAMS ((symbol_number_t accessing_symbol,
-			    size_t core_size, item_number_t *core));
+state *state_new (symbol_number accessing_symbol,
+		  size_t core_size, item_number *core);
+state *state_new_isocore (state const *s);
 
 /* Set the transitions of STATE.  */
-void state_transitions_set PARAMS ((state_t *state,
-				    int num, state_t **transitions));
+void state_transitions_set (state *s, int num, state **trans);
 
 /* Set the reductions of STATE.  */
-void state_reductions_set PARAMS ((state_t *state,
-				   int num, rule_t **reductions));
+void state_reductions_set (state *s, int num, rule **reds);
+
+int state_reduction_find (state *s, rule *r);
 
 /* Set the errs of STATE.  */
-void state_errs_set PARAMS ((state_t *state,
-			     int num, symbol_t **errs));
+void state_errs_set (state *s, int num, symbol **errors);
 
-/* Print on OUT all the lookaheads such that this STATE wants to
-   reduce this RULE.  */
-void state_rule_lookaheads_print PARAMS ((state_t *state, rule_t *rule,
-					  FILE *out));
+/* Print on OUT all the lookahead tokens such that this STATE wants to
+   reduce R.  */
+void state_rule_lookahead_tokens_print (state *s, rule *r, FILE *out);
+void state_rule_lookahead_tokens_print_xml (state *s, rule *r,
+					    FILE *out, int level);
 
 /* Create/destroy the states hash table.  */
-void state_hash_new PARAMS ((void));
-void state_hash_free PARAMS ((void));
+void state_hash_new (void);
+void state_hash_free (void);
 
 /* Find the state associated to the CORE, and return it.  If it does
    not exist yet, return NULL.  */
-state_t *state_hash_lookup PARAMS ((size_t core_size, item_number_t *core));
+state *state_hash_lookup (size_t core_size, item_number *core);
 
 /* Insert STATE in the state hash table.  */
-void state_hash_insert PARAMS ((state_t *state));
+void state_hash_insert (state *s);
+
+/* Remove unreachable states, renumber remaining states, update NSTATES, and
+   write to OLD_TO_NEW a mapping of old state numbers to new state numbers such
+   that the old value of NSTATES is written as the new state number for removed
+   states.  The size of OLD_TO_NEW must be the old value of NSTATES.  */
+void state_remove_unreachable_states (state_number old_to_new[]);
 
 /* All the states, indexed by the state number.  */
-extern state_t **states;
+extern state **states;
 
 /* Free all the states.  */
-void states_free PARAMS ((void));
+void states_free (void);
+
 #endif /* !STATE_H_ */