/* Type definitions for nondeterministic finite state machine for bison,
- Copyright 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.
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
+ 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. (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).
+ 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.
+ 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.
+ 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;
+# include "bitsetv.h"
-#define CORE_ALLOC(Nitems) \
- (core *) xcalloc ((unsigned) (sizeof (core) \
- + (Nitems - 1) * sizeof (short)), 1)
+/*---------.
+| 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 SHIFTS_ALLOC(Nshifts) \
- (shifts *) xcalloc ((unsigned) (sizeof (shifts) \
- + (Nshifts - 1) * sizeof (short)), 1)
+#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;
-#define ERRS_ALLOC(Nerrs) \
- (errs *) xcalloc ((unsigned) (sizeof (errs) \
- + (Nerrs - 1) * sizeof (short)), 1)
+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));
-#define REDUCTIONS_ALLOC(Nreductions) \
- (reductions *) xcalloc ((unsigned) (sizeof (reductions) \
- + (Nreductions - 1) * sizeof (short)), 1)
+
+/*----------.
+| State_t. |
+`----------*/
+
+typedef struct state_s
+{
+ struct state_s *next;
+ struct state_s *link;
+
+ short number;
+ symbol_number_t 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). */
+ 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;
+
+ /* Its items. Must be last, since ITEMS can be arbitrarily large.
+ */
+ unsigned short nitems;
+ item_number_t items[1];
+} state_t;
+
+#define STATE_ALLOC(Nitems) \
+ (state_t *) xcalloc ((unsigned) (sizeof (state_t) \
+ + (Nitems - 1) * sizeof (item_number_t)), 1)
+
+/* 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));
#endif /* !STATE_H_ */
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