/* Type definitions for nondeterministic finite state machine for bison,
- Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc.
+ Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
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
+ 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.
- The link field is used for chaining buckets that hash states by
+ The link field is used for chaining symbols that hash states by
their itemsets. This is for recognizing equivalent states and
combining them when the states are generated.
#ifndef STATE_H_
# define STATE_H_
-typedef struct core
-{
- struct core *next;
- struct core *link;
- short number;
- short accessing_symbol;
- short nitems;
- short items[1];
-}
-core;
-
+/*---------.
+| Shifts. |
+`---------*/
typedef struct shifts
{
- struct shifts *next;
- short number;
short nshifts;
short shifts[1];
-}
-shifts;
+} shifts;
+
+shifts *shifts_new PARAMS ((int n));
+
+
+/* What is the symbol which is shifted by SHIFTS->shifts[Shift]? Can
+ be a token (amongst which the error token), or non terminals in
+ case of gotos. */
+
+#define SHIFT_SYMBOL(Shifts, Shift) \
+ (states[Shifts->shifts[Shift]]->accessing_symbol)
+
+/* Is the SHIFTS->shifts[Shift] a real shift? (as opposed to gotos.) */
+
+#define SHIFT_IS_SHIFT(Shifts, Shift) \
+ (ISTOKEN (SHIFT_SYMBOL (Shifts, Shift)))
+
+/* Is the SHIFTS->shifts[Shift] a goto?. */
+
+#define SHIFT_IS_GOTO(Shifts, Shift) \
+ (!SHIFT_IS_SHIFT (Shifts, Shift))
+
+/* Is the SHIFTS->shifts[Shift] then handling of the error token?. */
+
+#define SHIFT_IS_ERROR(Shifts, Shift) \
+ (SHIFT_SYMBOL (Shifts, Shift) == errtoken->number)
+
+/* When resolving a SR conflicts, if the reduction wins, the shift is
+ disabled. */
+#define SHIFT_DISABLE(Shifts, Shift) \
+ (Shifts->shifts[Shift] = 0)
+#define SHIFT_IS_DISABLED(Shifts, Shift) \
+ (Shifts->shifts[Shift] == 0)
+
+
+/*-------.
+| Errs. |
+`-------*/
typedef struct errs
{
short nerrs;
short errs[1];
-}
-errs;
+} errs;
+errs *errs_new PARAMS ((int n));
+errs *errs_dup PARAMS ((errs *src));
+/*-------------.
+| Reductions. |
+`-------------*/
+
typedef struct reductions
{
- struct reductions *next;
- short number;
short nreds;
short rules[1];
-}
-reductions;
+} reductions;
+
+reductions *reductions_new PARAMS ((int n));
+
+
+/*----------.
+| State_t. |
+`----------*/
+
+typedef struct state_s
+{
+ struct state_s *next;
+ struct state_s *link;
+
+ short number;
+ short accessing_symbol;
+ shifts *shifts;
+ reductions *reductions;
+ errs *errs;
+
+ /* Nonzero if no lookahead is needed to decide what to do in state S. */
+ char consistent;
+
+ /* Used in LALR, not LR(0). */
+ /* Pseudo pointer into LA. */
+ short lookaheadsp;
+ int nlookaheads;
+
+ /* Its items. */
+ short nitems;
+ item_number_t items[1];
+} state_t;
-extern int nstates;
-extern core *first_state;
-extern shifts *first_shift;
-extern reductions *first_reduction;
+#define STATE_ALLOC(Nitems) \
+ (state_t *) xcalloc ((unsigned) (sizeof (state_t) \
+ + (Nitems - 1) * sizeof (item_number_t)), 1)
#endif /* !STATE_H_ */