Add native Windows binary for bison.

bison/src/bison/2.4.1/bison-2.4.1-src/src/state.h

+/* Type definitions for nondeterministic finite state machine for Bison.
+
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2003, 2004, 2007 Free
+   Software Foundation, Inc.
+
+   This file is part of Bison, the GNU Compiler Compiler.
+
+   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 3 of the License, or
+   (at your option) any later version.
+
+   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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+
+/* These type definitions are used to represent a nondeterministic
+   finite state machine that parses the specified grammar.  This
+   information is generated by the function generate_states in the
+   file LR0.
+
+   Each state of the machine is described by a set of items --
+   particular positions in particular rules -- that are the possible
+   places where parsing could continue when the machine is in this
+   state.  These symbols at these items are the allowable inputs that
+   can follow now.
+
+   A core represents one state.  States are numbered in the NUMBER
+   field.  When generate_states is finished, the starting state is
+   state 0 and NSTATES is the number of states.  (FIXME: This sentence
+   is no longer true: A transition to a state whose state number is
+   NSTATES indicates termination.)  All the cores are chained together
+   and FIRST_STATE points to the first one (state 0).
+
+   For each state there is a particular symbol which must have been
+   the last thing accepted to reach that state.  It is the
+   ACCESSING_SYMBOL of the core.
+
+   Each core contains a vector of NITEMS items which are the indices
+   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
+   reductions (combine the last n things on the stack via a rule,
+   replace them with the symbol that the rule derives, and leave the
+   lookahead token alone).  When the states are generated, these
+   actions are represented in two other lists.
+
+   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
+   kind of input leads to them.
+
+   A transition to state zero should be ignored: conflict resolution
+   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.  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).
+   For each state, the tokens that are errors for this reason are
+   recorded in an errs structure, which holds the token numbers.
+
+   There is at least one goto transition present in state zero.  It
+   leads to a next-to-final state whose accessing_symbol is the
+   grammar's start symbol.  The next-to-final state has one shift to
+   the final state, whose accessing_symbol is zero (end of input).
+   The final state has one shift, which goes to the termination state.
+   The reason for the extra state at the end is to placate the
+   parser's strategy of making all decisions one token ahead of its
+   actions.  */
+
+#ifndef STATE_H_
+# define STATE_H_
+
+# include <bitset.h>
+
+# include "gram.h"
+# include "symtab.h"
+
+
+/*-------------------.
+| Numbering states.  |
+`-------------------*/
+
+typedef int state_number;
+# define STATE_NUMBER_MAXIMUM INT_MAX
+
+/* 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 state;
+
+/*--------------.
+| Transitions.  |
+`--------------*/
+
+typedef struct
+{
+  int num;
+  state *states[1];
+} transitions;
+
+
+/* What is the symbol labelling the transition to
+   TRANSITIONS->states[Num]?  Can be a token (amongst which the error
+   token), or non terminals in case of gotos.  */
+
+#define TRANSITION_SYMBOL(Transitions, Num) \
+  (Transitions->states[Num]->accessing_symbol)
+
+/* Is the TRANSITIONS->states[Num] a shift? (as opposed to gotos).  */
+
+#define TRANSITION_IS_SHIFT(Transitions, Num) \
+  (ISTOKEN (TRANSITION_SYMBOL (Transitions, Num)))
+
+/* Is the TRANSITIONS->states[Num] a goto?. */
+
+#define TRANSITION_IS_GOTO(Transitions, Num) \
+  (!TRANSITION_IS_SHIFT (Transitions, Num))
+
+/* Is the TRANSITIONS->states[Num] labelled by the error token?  */
+
+#define TRANSITION_IS_ERROR(Transitions, Num) \
+  (TRANSITION_SYMBOL (Transitions, Num) == errtoken->number)
+
+/* When resolving a SR conflicts, if the reduction wins, the shift is
+   disabled.  */
+
+#define TRANSITION_DISABLE(Transitions, Num) \
+  (Transitions->states[Num] = NULL)
+
+#define TRANSITION_IS_DISABLED(Transitions, Num) \
+  (Transitions->states[Num] == NULL)
+
+
+/* Iterate over each transition over a token (shifts).  */
+#define FOR_EACH_SHIFT(Transitions, Iter)                       \
+  for (Iter = 0;                                                \
+       Iter < Transitions->num                                  \
+         && (TRANSITION_IS_DISABLED (Transitions, Iter)         \
+             || TRANSITION_IS_SHIFT (Transitions, Iter));       \
+       ++Iter)                                                  \
+    if (!TRANSITION_IS_DISABLED (Transitions, Iter))
+
+
+/* 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
+{
+  int num;
+  symbol *symbols[1];
+} errs;
+
+errs *errs_new (int num, symbol **tokens);
+
+
+/*-------------.
+| Reductions.  |
+`-------------*/
+
+typedef struct
+{
+  int num;
+  bitset *lookahead_tokens;
+  /* Sorted ascendingly on rule number.  */
+  rule *rules[1];
+} reductions;
+
+
+
+/*---------.
+| states.  |
+`---------*/
+
+struct state
+{
+  state_number number;
+  symbol_number accessing_symbol;
+  transitions *transitions;
+  reductions *reductions;
+  errs *errs;
+
+  /* If non-zero, then no lookahead sets on reduce actions are needed to
+     decide what to do in state S.  */
+  char consistent;
+
+  /* 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.  Sorted
+     ascendingly on item index in RITEM, which is sorted on rule number.  */
+  size_t nitems;
+  item_number items[1];
+};
+
+extern state_number nstates;
+extern state *final_state;
+
+/* Create a new state with ACCESSING_SYMBOL for those items.  */
+state *state_new (symbol_number accessing_symbol,
+                  size_t core_size, item_number *core);
+
+/* Set the transitions of STATE.  */
+void state_transitions_set (state *s, int num, state **trans);
+
+/* Set the reductions of STATE.  */
+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 (state *s, int num, symbol **errors);
+
+/* 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 (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 *state_hash_lookup (size_t core_size, item_number *core);
+
+/* Insert STATE in the state hash table.  */
+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 **states;
+
+/* Free all the states.  */
+void states_free (void);
+
+#endif /* !STATE_H_ */