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* src/conflicts.c (log_resolution): Accept the rule involved in

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the sr conflicts instead of the lookahead number that points to
that rule.
(flush_reduce): Accept the current lookahead vector as argument,
instead of the index in LA.
(resolve_sr_conflict): Accept the current number of lookahead
bitset to consider for the STATE, instead of the index in LA.
(set_conflicts): Adjust.
* src/lalr.c, src/lalr.h, src/state.h: Comment changes.
This commit is contained in:
Akim Demaille
2002-06-15 18:24:08 +00:00
parent c026349221
commit 9801d40c50
5 changed files with 53 additions and 31 deletions
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51
src/conflicts.c
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@@ -52,8 +52,13 @@ enum conflict_resolution_e
};
/*----------------------------------------------------------------.
| Explain how an SR conflict between TOKEN and RULE was resolved: |
| RESOLUTION. |
`----------------------------------------------------------------*/
static inline void
log_resolution (int lookahead, int token,
log_resolution (rule_t *rule, int token,
enum conflict_resolution_e resolution)
{
if (report_flag & report_solved_conflicts)
@@ -66,7 +71,7 @@ log_resolution (int lookahead, int token,
obstack_fgrow2 (&solved_conflicts_obstack,
_("\
Conflict between rule %d and token %s resolved as shift"),
LArule[lookahead]->number,
rule->number,
symbols[token]->tag);
break;
case reduce_resolution:
@@ -74,14 +79,14 @@ log_resolution (int lookahead, int token,
obstack_fgrow2 (&solved_conflicts_obstack,
_("\
Conflict between rule %d and token %s resolved as reduce"),
LArule[lookahead]->number,
rule->number,
symbols[token]->tag);
break;
case nonassoc_resolution:
obstack_fgrow2 (&solved_conflicts_obstack,
_("\
Conflict between rule %d and token %s resolved as an error"),
LArule[lookahead]->number,
rule->number,
symbols[token]->tag);
break;
}
@@ -92,7 +97,7 @@ log_resolution (int lookahead, int token,
case shift_resolution:
obstack_fgrow2 (&solved_conflicts_obstack,
" (%s < %s)",
LArule[lookahead]->prec->tag,
rule->prec->tag,
symbols[token]->tag);
break;
@@ -100,7 +105,7 @@ log_resolution (int lookahead, int token,
obstack_fgrow2 (&solved_conflicts_obstack,
" (%s < %s)",
symbols[token]->tag,
LArule[lookahead]->prec->tag);
rule->prec->tag);
break;
case left_resolution:
@@ -151,9 +156,9 @@ flush_shift (state_t *state, int token)
`-------------------------------------------------------------------*/
static void
flush_reduce (int lookahead, int token)
flush_reduce (bitset lookaheads, int token)
{
bitset_reset (LA[lookahead], token);
bitset_reset (lookaheads, token);
}
@@ -162,19 +167,23 @@ flush_reduce (int lookahead, int token)
| precedence declarations. It has already been checked that the |
| rule has a precedence. A conflict is resolved by modifying the |
| shift or reduce tables so that there is no longer a conflict. |
| |
| LOOKAHEAD is the number of the lookahead bitset to consider. |
`------------------------------------------------------------------*/
static void
resolve_sr_conflict (state_t *state, int lookahead)
{
int i;
/* find the rule to reduce by to get precedence of reduction */
int redprec = LArule[lookahead]->prec->prec;
/* Find the rule to reduce by to get precedence of reduction. */
rule_t *redrule = state->lookaheads_rule[lookahead];
int redprec = redrule->prec->prec;
bitset lookaheads = state->lookaheads[lookahead];
errs *errp = errs_new (ntokens + 1);
errp->nerrs = 0;
for (i = 0; i < ntokens; i++)
if (bitset_test (LA[lookahead], i)
if (bitset_test (lookaheads, i)
&& bitset_test (lookaheadset, i)
&& symbols[i]->prec)
{
@@ -183,13 +192,13 @@ resolve_sr_conflict (state_t *state, int lookahead)
The precedence of shifting is that of token i. */
if (symbols[i]->prec < redprec)
{
log_resolution (lookahead, i, reduce_resolution);
log_resolution (redrule, i, reduce_resolution);
flush_shift (state, i);
}
else if (symbols[i]->prec > redprec)
{
log_resolution (lookahead, i, shift_resolution);
flush_reduce (lookahead, i);
log_resolution (redrule, i, shift_resolution);
flush_reduce (lookaheads, i);
}
else
/* Matching precedence levels.
@@ -200,19 +209,19 @@ resolve_sr_conflict (state_t *state, int lookahead)
switch (symbols[i]->assoc)
{
case right_assoc:
log_resolution (lookahead, i, right_resolution);
flush_reduce (lookahead, i);
log_resolution (redrule, i, right_resolution);
flush_reduce (lookaheads, i);
break;
case left_assoc:
log_resolution (lookahead, i, left_resolution);
log_resolution (redrule, i, left_resolution);
flush_shift (state, i);
break;
case non_assoc:
log_resolution (lookahead, i, nonassoc_resolution);
log_resolution (redrule, i, nonassoc_resolution);
flush_shift (state, i);
flush_reduce (lookahead, i);
flush_reduce (lookaheads, i);
/* Record an explicit error for this token. */
errp->errs[errp->nerrs++] = i;
break;
@@ -254,13 +263,13 @@ set_conflicts (state_t *state)
/* Loop over all rules which require lookahead in this state. First
check for shift-reduce conflict, and try to resolve using
precedence */
precedence. */
for (i = 0; i < state->nlookaheads; ++i)
if (state->lookaheads_rule[i]->prec
&& state->lookaheads_rule[i]->prec->prec
&& !bitset_disjoint_p (state->lookaheads[i], lookaheadset))
{
resolve_sr_conflict (state, (state->lookaheads - LA) + i);
resolve_sr_conflict (state, i);
break;
}