#include "reader.h"
#include "LR0.h"
-errs **err_table = NULL;
/* -1 stands for not specified. */
int expected_conflicts = -1;
static char *conflicts = NULL;
static inline void
log_resolution (int state, int LAno, int token, char *resolution)
{
- obstack_fgrow4 (&output_obstack,
- _("\
+ if (verbose_flag)
+ obstack_fgrow4 (&output_obstack,
+ _("\
Conflict in state %d between rule %d and token %s resolved as %s.\n"),
- state, LAruleno[LAno], tags[token], resolution);
+ state, LAruleno[LAno], tags[token], resolution);
}
static void
flush_shift (int state, int token)
{
- shifts *shiftp;
- int k, i;
+ shifts *shiftp = state_table[state]->shifts;
+ int i;
- shiftp = state_table[state].shift_table;
+ RESETBIT (lookaheadset, token);
+ for (i = 0; i < shiftp->nshifts; i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i) && SHIFT_SYMBOL (shiftp, i) == token)
+ SHIFT_DISABLE (shiftp, i);
+}
- if (shiftp)
- {
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- if (shiftp->shifts[i]
- && token == state_table[shiftp->shifts[i]].accessing_symbol)
- (shiftp->shifts[i]) = 0;
- }
- }
+
+/*-------------------------------------------------------------------.
+| Turn off the reduce recorded for the specified token for the |
+| specified lookahead. Used when we resolve a shift-reduce conflict |
+| in favor of the shift. |
+`-------------------------------------------------------------------*/
+
+static void
+flush_reduce (int lookahead, int token)
+{
+ RESETBIT (LA (lookahead), token);
}
`------------------------------------------------------------------*/
static void
-resolve_sr_conflict (int state, int lookaheadnum)
+resolve_sr_conflict (int state, int lookahead)
{
int i;
- int mask;
- unsigned *fp1;
- unsigned *fp2;
- int redprec;
+ /* find the rule to reduce by to get precedence of reduction */
+ int redprec = rule_table[LAruleno[lookahead]].prec;
errs *errp = ERRS_ALLOC (ntokens + 1);
short *errtokens = errp->errs;
- /* find the rule to reduce by to get precedence of reduction */
- redprec = rule_table[LAruleno[lookaheadnum]].prec;
-
- mask = 1;
- fp1 = LA (lookaheadnum);
- fp2 = lookaheadset;
for (i = 0; i < ntokens; i++)
- {
- if ((mask & *fp2 & *fp1) && sprec[i])
+ if (BITISSET (LA (lookahead), i)
+ && BITISSET (lookaheadset, i)
+ && sprec[i])
+ {
/* Shift-reduce conflict occurs for token number i
and it has a precedence.
The precedence of shifting is that of token i. */
- {
- if (sprec[i] < redprec)
- {
- log_resolution (state, lookaheadnum, i, _("reduce"));
- *fp2 &= ~mask; /* flush the shift for this token */
- flush_shift (state, i);
- }
- else if (sprec[i] > redprec)
- {
- log_resolution (state, lookaheadnum, i, _("shift"));
- *fp1 &= ~mask; /* flush the reduce for this token */
- }
- else
- {
- /* Matching precedence levels.
- For left association, keep only the reduction.
- For right association, keep only the shift.
- For nonassociation, keep neither. */
-
- switch (sassoc[i])
- {
- case right_assoc:
- log_resolution (state, lookaheadnum, i, _("shift"));
- break;
+ if (sprec[i] < redprec)
+ {
+ log_resolution (state, lookahead, i, _("reduce"));
+ flush_shift (state, i);
+ }
+ else if (sprec[i] > redprec)
+ {
+ log_resolution (state, lookahead, i, _("shift"));
+ flush_reduce (lookahead, i);
+ }
+ else
+ /* Matching precedence levels.
+ For left association, keep only the reduction.
+ For right association, keep only the shift.
+ For nonassociation, keep neither. */
- case left_assoc:
- log_resolution (state, lookaheadnum, i, _("reduce"));
- break;
+ switch (sassoc[i])
+ {
+ case right_assoc:
+ log_resolution (state, lookahead, i, _("shift"));
+ flush_reduce (lookahead, i);
+ break;
- case non_assoc:
- log_resolution (state, lookaheadnum, i, _("an error"));
- break;
- }
+ case left_assoc:
+ log_resolution (state, lookahead, i, _("reduce"));
+ flush_shift (state, i);
+ break;
- if (sassoc[i] != right_assoc)
- {
- *fp2 &= ~mask; /* flush the shift for this token */
- flush_shift (state, i);
- }
- if (sassoc[i] != left_assoc)
- {
- *fp1 &= ~mask; /* flush the reduce for this token */
- }
- if (sassoc[i] == non_assoc)
- {
- /* Record an explicit error for this token. */
- *errtokens++ = i;
- }
+ case non_assoc:
+ log_resolution (state, lookahead, i, _("an error"));
+ flush_shift (state, i);
+ flush_reduce (lookahead, i);
+ /* Record an explicit error for this token. */
+ *errtokens++ = i;
+ break;
}
- }
+ }
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- fp2++;
- fp1++;
- }
- }
errp->nerrs = errtokens - errp->errs;
- if (errp->nerrs)
- {
- /* Some tokens have been explicitly made errors. Allocate
- a permanent errs structure for this state, to record them. */
- i = (char *) errtokens - (char *) errp;
- err_table[state] = ERRS_ALLOC (i + 1);
- bcopy (errp, err_table[state], i);
- }
- else
- err_table[state] = 0;
+ /* Some tokens have been explicitly made errors. Allocate a
+ permanent errs structure for this state, to record them. */
+ i = (char *) errtokens - (char *) errp;
+ state_table[state]->errs = ERRS_ALLOC (i + 1);
+ memcpy (state_table[state]->errs, errp, i);
free (errp);
}
{
int i, j;
shifts *shiftp;
- int symbol;
- if (state_table[state].consistent)
+ if (state_table[state]->consistent)
return;
for (i = 0; i < tokensetsize; i++)
lookaheadset[i] = 0;
- shiftp = state_table[state].shift_table;
- if (shiftp)
- for (i = 0; i < shiftp->nshifts; i++)
- {
- symbol = state_table[shiftp->shifts[i]].accessing_symbol;
- if (ISVAR (symbol))
- break;
- SETBIT (lookaheadset, symbol);
- }
+ shiftp = state_table[state]->shifts;
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
+ SETBIT (lookaheadset, SHIFT_SYMBOL (shiftp, i));
/* Loop over all rules which require lookahead in this state. First
check for shift-reduce conflict, and try to resolve using
precedence */
- for (i = state_table[state].lookaheads;
- i < state_table[state + 1].lookaheads;
+ for (i = state_table[state]->lookaheads;
+ i < state_table[state + 1]->lookaheads;
++i)
if (rule_table[LAruleno[i]].prec)
for (j = 0; j < tokensetsize; ++j)
/* Loop over all rules which require lookahead in this state. Check
for conflicts not resolved above. */
- for (i = state_table[state].lookaheads;
- i < state_table[state + 1].lookaheads;
+ for (i = state_table[state]->lookaheads;
+ i < state_table[state + 1]->lookaheads;
++i)
{
for (j = 0; j < tokensetsize; ++j)
shiftset = XCALLOC (unsigned, tokensetsize);
lookaheadset = XCALLOC (unsigned, tokensetsize);
- err_table = XCALLOC (errs *, nstates);
-
for (i = 0; i < nstates; i++)
set_conflicts (i);
}
static int
count_sr_conflicts (int state)
{
- int i;
- int k;
- int mask;
- shifts *shiftp;
- unsigned *fp1;
- unsigned *fp2;
- unsigned *fp3;
- int symbol;
-
+ int i, k;
int src_count = 0;
+ shifts *shiftp = state_table[state]->shifts;
- shiftp = state_table[state].shift_table;
if (!shiftp)
return 0;
lookaheadset[i] = 0;
}
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- if (!shiftp->shifts[i])
- continue;
- symbol = state_table[shiftp->shifts[i]].accessing_symbol;
- if (ISVAR (symbol))
- break;
- SETBIT (shiftset, symbol);
- }
-
- k = state_table[state + 1].lookaheads;
- fp3 = lookaheadset + tokensetsize;
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
+ SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
- for (i = state_table[state].lookaheads; i < k; i++)
- {
- fp1 = LA (i);
- fp2 = lookaheadset;
-
- while (fp2 < fp3)
- *fp2++ |= *fp1++;
- }
-
- fp1 = shiftset;
- fp2 = lookaheadset;
+ for (i = state_table[state]->lookaheads;
+ i < state_table[state + 1]->lookaheads;
+ ++i)
+ for (k = 0; k < tokensetsize; ++k)
+ lookaheadset[k] |= LA (i)[k];
- while (fp2 < fp3)
- *fp2++ &= *fp1++;
+ for (k = 0; k < tokensetsize; ++k)
+ lookaheadset[k] &= shiftset[k];
- mask = 1;
- fp2 = lookaheadset;
for (i = 0; i < ntokens; i++)
- {
- if (mask & *fp2)
- src_count++;
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- fp2++;
- }
- }
+ if (BITISSET (lookaheadset, i))
+ src_count++;
return src_count;
}
count_rr_conflicts (int state)
{
int i;
- unsigned mask;
- unsigned *baseword;
-
int rrc_count = 0;
- int m = state_table[state].lookaheads;
- int n = state_table[state + 1].lookaheads;
+ int m = state_table[state]->lookaheads;
+ int n = state_table[state + 1]->lookaheads;
if (n - m < 2)
return 0;
- mask = 1;
- baseword = LA (m);
for (i = 0; i < ntokens; i++)
{
- unsigned *wordp = baseword;
-
int count = 0;
int j;
for (j = m; j < n; j++)
- {
- if (mask & *wordp)
- count++;
-
- wordp += tokensetsize;
- }
+ if (BITISSET (LA (m), j))
+ count++;
if (count >= 2)
rrc_count++;
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- baseword++;
- }
}
return rrc_count;
{
int i;
int j;
- int symbol;
- unsigned mask;
- int m;
- int n;
- int default_LA;
- int default_rule = 0;
- int cmax;
- int count;
- shifts *shiftp;
- errs *errp;
+ int m = state_table[state]->lookaheads;
+ int n = state_table[state + 1]->lookaheads;
+ shifts *shiftp = state_table[state]->shifts;
+ errs *errp = state_table[state]->errs;
int nodefault = 0;
for (i = 0; i < tokensetsize; i++)
shiftset[i] = 0;
- shiftp = state_table[state].shift_table;
- if (shiftp)
- for (i = 0; i < shiftp->nshifts; i++)
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
{
- if (!shiftp->shifts[i])
- continue;
- symbol = state_table[shiftp->shifts[i]].accessing_symbol;
- if (ISVAR (symbol))
- break;
- /* if this state has a shift for the error token,
- don't use a default rule. */
- if (symbol == error_token_number)
+ /* if this state has a shift for the error token, don't use a
+ default rule. */
+ if (SHIFT_IS_ERROR (shiftp, i))
nodefault = 1;
- SETBIT (shiftset, symbol);
+ SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
}
- errp = err_table[state];
if (errp)
- {
- for (i = 0; i < errp->nerrs; i++)
- {
- if (!errp->errs[i])
- continue;
- SETBIT (shiftset, errp->errs[i]);
- }
- }
-
- m = state_table[state].lookaheads;
- n = state_table[state + 1].lookaheads;
+ for (i = 0; i < errp->nerrs; i++)
+ if (errp->errs[i])
+ SETBIT (shiftset, errp->errs[i]);
if (n - m == 1 && !nodefault)
{
int k;
- default_rule = LAruleno[m];
+ int default_rule = LAruleno[m];
for (k = 0; k < tokensetsize; ++k)
lookaheadset[k] = LA (m)[k] & shiftset[k];
}
else if (n - m >= 1)
{
- unsigned *fp1, *fp2, *fp3, *fp4;
+ int k;
- cmax = 0;
- default_LA = -1;
- fp4 = lookaheadset + tokensetsize;
+ int cmax = 0;
+ int default_LA = -1;
+ int default_rule = 0;
if (!nodefault)
for (i = m; i < n; i++)
{
- fp1 = LA (i);
- fp2 = shiftset;
- fp3 = lookaheadset;
+ int count = 0;
- while (fp3 < fp4)
- *fp3++ = *fp1++ & (~(*fp2++));
+ for (k = 0; k < tokensetsize; ++k)
+ lookaheadset[k] = LA (i)[k] & ~shiftset[k];
- count = 0;
- mask = 1;
- fp3 = lookaheadset;
for (j = 0; j < ntokens; j++)
- {
- if (mask & *fp3)
- count++;
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- fp3++;
- }
- }
+ if (BITISSET (lookaheadset, j))
+ count++;
if (count > cmax)
{
default_rule = LAruleno[i];
}
- fp2 = shiftset;
- fp3 = lookaheadset;
-
- while (fp3 < fp4)
- *fp2++ |= *fp3++;
+ for (k = 0; k < tokensetsize; ++k)
+ shiftset[k] |= lookaheadset[k];
}
for (i = 0; i < tokensetsize; i++)
shiftset[i] = 0;
- if (shiftp)
- {
- for (i = 0; i < shiftp->nshifts; i++)
- {
- if (!shiftp->shifts[i])
- continue;
- symbol = state_table[shiftp->shifts[i]].accessing_symbol;
- if (ISVAR (symbol))
- break;
- SETBIT (shiftset, symbol);
- }
- }
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
+ SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
- mask = 1;
- fp1 = LA (m);
- fp2 = shiftset;
for (i = 0; i < ntokens; i++)
{
int defaulted = 0;
+ int count = BITISSET (shiftset, i);
- if (mask & *fp2)
- count = 1;
- else
- count = 0;
-
- fp3 = fp1;
for (j = m; j < n; j++)
{
- if (mask & *fp3)
+ if (BITISSET (LA (m), j))
{
if (count == 0)
{
tags[rule_table[LAruleno[j]].lhs]);
}
}
-
- fp3 += tokensetsize;
- }
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- /* We tried incrementing just fp1, and just fp2; both seem wrong.
- It seems necessary to increment both in sync. */
- fp1++;
- fp2++;
}
}
projects / bison.git / blobdiff