-/* Find and resolve or report look-ahead conflicts for bison,
+/* Find and resolve or report lookahead conflicts for bison,
Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006
Free Software Foundation, Inc.
static struct obstack solved_conflicts_obstack;
static bitset shift_set;
-static bitset look_ahead_set;
+static bitset lookahead_set;
\f
transitions *trans = s->transitions;
int i;
- bitset_reset (look_ahead_set, token);
+ bitset_reset (lookahead_set, token);
for (i = 0; i < trans->num; i++)
if (!TRANSITION_IS_DISABLED (trans, i)
&& TRANSITION_SYMBOL (trans, i) == token)
/*--------------------------------------------------------------------.
| Turn off the reduce recorded for the specified token for the |
-| specified look-ahead. Used when we resolve a shift-reduce conflict |
+| specified lookahead. Used when we resolve a shift-reduce conflict |
| in favor of the shift. |
`--------------------------------------------------------------------*/
static void
-flush_reduce (bitset look_ahead_tokens, int token)
+flush_reduce (bitset lookahead_tokens, int token)
{
- bitset_reset (look_ahead_tokens, token);
+ bitset_reset (lookahead_tokens, token);
}
| rule has a precedence. A conflict is resolved by modifying the |
| shift or reduce tables so that there is no longer a conflict. |
| |
-| RULENO is the number of the look-ahead bitset to consider. |
+| RULENO is the number of the lookahead bitset to consider. |
| |
| ERRORS can be used to store discovered explicit errors. |
`------------------------------------------------------------------*/
/* Find the rule to reduce by to get precedence of reduction. */
rule *redrule = reds->rules[ruleno];
int redprec = redrule->prec->prec;
- bitset look_ahead_tokens = reds->look_ahead_tokens[ruleno];
+ bitset lookahead_tokens = reds->lookahead_tokens[ruleno];
int nerrs = 0;
for (i = 0; i < ntokens; i++)
- if (bitset_test (look_ahead_tokens, i)
- && bitset_test (look_ahead_set, i)
+ if (bitset_test (lookahead_tokens, i)
+ && bitset_test (lookahead_set, i)
&& symbols[i]->prec)
{
/* Shift-reduce conflict occurs for token number i
else if (symbols[i]->prec > redprec)
{
log_resolution (redrule, i, shift_resolution);
- flush_reduce (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
}
else
/* Matching precedence levels.
case right_assoc:
log_resolution (redrule, i, right_resolution);
- flush_reduce (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
break;
case left_assoc:
case non_assoc:
log_resolution (redrule, i, nonassoc_resolution);
flush_shift (s, i);
- flush_reduce (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
/* Record an explicit error for this token. */
errors[nerrs++] = symbols[i];
break;
| Solve the S/R conflicts of state S using the |
| precedence/associativity, and flag it inconsistent if it still has |
| conflicts. ERRORS can be used as storage to compute the list of |
-| look-ahead tokens on which S raises a syntax error (%nonassoc). |
+| lookahead tokens on which S raises a syntax error (%nonassoc). |
`-------------------------------------------------------------------*/
static void
if (s->consistent)
return;
- bitset_zero (look_ahead_set);
+ bitset_zero (lookahead_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (look_ahead_set, TRANSITION_SYMBOL (trans, i));
+ bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, i));
- /* Loop over all rules which require look-ahead in this state. First
+ /* Loop over all rules which require lookahead in this state. First
check for shift-reduce conflict, and try to resolve using
precedence. */
for (i = 0; i < reds->num; ++i)
if (reds->rules[i]->prec && reds->rules[i]->prec->prec
- && !bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
+ && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
resolve_sr_conflict (s, i, errors);
- /* Loop over all rules which require look-ahead in this state. Check
+ /* Loop over all rules which require lookahead in this state. Check
for conflicts not resolved above. */
for (i = 0; i < reds->num; ++i)
{
- if (!bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
+ if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
conflicts[s->number] = 1;
- bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
}
}
conflicts_solve (void)
{
state_number i;
- /* List of look-ahead tokens on which we explicitly raise a syntax error. */
+ /* List of lookahead tokens on which we explicitly raise a syntax error. */
symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
conflicts = xcalloc (nstates, sizeof *conflicts);
shift_set = bitset_create (ntokens, BITSET_FIXED);
- look_ahead_set = bitset_create (ntokens, BITSET_FIXED);
+ lookahead_set = bitset_create (ntokens, BITSET_FIXED);
obstack_init (&solved_conflicts_obstack);
for (i = 0; i < nstates; i++)
if (!trans)
return 0;
- bitset_zero (look_ahead_set);
+ bitset_zero (lookahead_set);
bitset_zero (shift_set);
FOR_EACH_SHIFT (trans, i)
bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
for (i = 0; i < reds->num; ++i)
- bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
- bitset_and (look_ahead_set, look_ahead_set, shift_set);
+ bitset_and (lookahead_set, lookahead_set, shift_set);
- src_count = bitset_count (look_ahead_set);
+ src_count = bitset_count (lookahead_set);
return src_count;
}
int count = 0;
int j;
for (j = 0; j < reds->num; ++j)
- if (bitset_test (reds->look_ahead_tokens[j], i))
+ if (bitset_test (reds->lookahead_tokens[j], i))
count++;
if (count >= 2)
/*--------------------------------------------------------.
| Total the number of S/R and R/R conflicts. Unlike the |
| code in conflicts_output, however, count EACH pair of |
-| reductions for the same state and look-ahead as one |
+| reductions for the same state and lookahead as one |
| conflict. |
`--------------------------------------------------------*/
{
free (conflicts);
bitset_free (shift_set);
- bitset_free (look_ahead_set);
+ bitset_free (lookahead_set);
obstack_free (&solved_conflicts_obstack, NULL);
}
projects / bison.git / blobdiff