/* Find and resolve or report look-ahead conflicts for bison,
- Copyright (C) 1984, 1989, 1992, 2000 Free Software Foundation, Inc.
+ Copyright 1984, 1989, 1992, 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
02111-1307, USA. */
#include "system.h"
+#include "bitset.h"
+#include "complain.h"
#include "getargs.h"
-#include "alloc.h"
+#include "symtab.h"
#include "files.h"
#include "gram.h"
#include "state.h"
#include "reader.h"
#include "LR0.h"
-int any_conflicts = 0;
-errs **err_table;
-int expected_conflicts;
-static char *conflicts;
-
-static unsigned *shiftset;
-static unsigned *lookaheadset;
-static int src_total;
-static int rrc_total;
-static int src_count;
-static int rrc_count;
+/* -1 stands for not specified. */
+int expected_conflicts = -1;
+static char *conflicts = NULL;
+
+static bitset shiftset;
+static bitset lookaheadset;
\f
static inline void
-log_resolution (int state, int LAno, int token, char *resolution)
+log_resolution (state_t *state, int LAno, int token, char *resolution)
{
- if (verboseflag)
- fprintf (foutput,
- _("\
+ 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->number, LAruleno[LAno], symbols[token]->tag,
+ resolution);
}
`------------------------------------------------------------------*/
static void
-flush_shift (int state, int token)
+flush_shift (state_t *state, int token)
{
- shifts *shiftp;
- int k, i;
+ shifts *shiftp = state->shifts;
+ int i;
- shiftp = shift_table[state];
+ bitset_reset (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 == accessing_symbol[shiftp->shifts[i]])
- (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)
+{
+ bitset_reset (LA[lookahead], token);
}
`------------------------------------------------------------------*/
static void
-resolve_sr_conflict (int state, int lookaheadnum)
+resolve_sr_conflict (state_t *state, int lookahead)
{
int i;
- int mask;
- unsigned *fp1;
- unsigned *fp2;
- int redprec;
- errs *errp = (errs *) xmalloc (sizeof (errs) + ntokens * sizeof (short));
- short *errtokens = errp->errs;
-
/* find the rule to reduce by to get precedence of reduction */
- redprec = rprec[LAruleno[lookaheadnum]];
+ int redprec = rules[LAruleno[lookahead]].prec;
+ errs *errp = errs_new (ntokens + 1);
+ errp->nerrs = 0;
- mask = 1;
- fp1 = LA + lookaheadnum * tokensetsize;
- fp2 = lookaheadset;
for (i = 0; i < ntokens; i++)
- {
- if ((mask & *fp2 & *fp1) && sprec[i])
+ if (bitset_test (LA[lookahead], i)
+ && bitset_test (lookaheadset, i)
+ && symbols[i]->prec)
+ {
/* 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)
+ if (symbols[i]->prec < redprec)
+ {
+ log_resolution (state, lookahead, i, _("reduce"));
+ flush_shift (state, i);
+ }
+ else if (symbols[i]->prec > 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. */
+
+ switch (symbols[i]->assoc)
{
- log_resolution (state, lookaheadnum, i, _("reduce"));
- *fp2 &= ~mask; /* flush the shift for this token */
+ case right_assoc:
+ log_resolution (state, lookahead, i, _("shift"));
+ flush_reduce (lookahead, i);
+ break;
+
+ case left_assoc:
+ log_resolution (state, lookahead, i, _("reduce"));
flush_shift (state, i);
+ break;
+
+ 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. */
+ errp->errs[errp->nerrs++] = i;
+ break;
}
- 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;
-
- case LEFT_ASSOC:
- log_resolution (state, lookaheadnum, i, _("reduce"));
- break;
-
- case NON_ASSOC:
- log_resolution (state, lookaheadnum, i, _("an error"));
- 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;
- }
- }
- }
-
- 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 *) xmalloc ((unsigned int) i);
- 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. */
+ state->errs = errs_dup (errp);
free (errp);
}
static void
-set_conflicts (int state)
+set_conflicts (state_t *state)
{
- int i;
- int k;
+ int i, j;
shifts *shiftp;
- unsigned *fp2;
- unsigned *fp3;
- unsigned *fp4;
- unsigned *fp1;
- int symbol;
- if (consistent[state])
+ if (state->consistent)
return;
- for (i = 0; i < tokensetsize; i++)
- lookaheadset[i] = 0;
-
- shiftp = shift_table[state];
- if (shiftp)
- {
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- symbol = accessing_symbol[shiftp->shifts[i]];
- if (ISVAR (symbol))
- break;
- SETBIT (lookaheadset, symbol);
- }
- }
+ bitset_zero (lookaheadset);
- k = lookaheads[state + 1];
- fp4 = lookaheadset + tokensetsize;
+ shiftp = state->shifts;
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
+ bitset_set (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 = lookaheads[state]; i < k; i++)
- if (rprec[LAruleno[i]])
- {
- fp1 = LA + i * tokensetsize;
- fp2 = fp1;
- fp3 = lookaheadset;
-
- while (fp3 < fp4)
+ for (i = 0; i < state->nlookaheads; ++i)
+ if (rules[LAruleno[state->lookaheadsp + i]].prec)
+ for (j = 0; j < ntokens; ++j)
+ if (bitset_test (LA[state->lookaheadsp + i], j)
+ && bitset_test (lookaheadset, j))
{
- if (*fp2++ & *fp3++)
- {
- resolve_sr_conflict (state, i);
- break;
- }
+ resolve_sr_conflict (state, state->lookaheadsp + i);
+ break;
}
- }
/* Loop over all rules which require lookahead in this state. Check
for conflicts not resolved above. */
- for (i = lookaheads[state]; i < k; i++)
+ for (i = 0; i < state->nlookaheads; ++i)
{
- fp1 = LA + i * tokensetsize;
- fp2 = fp1;
- fp3 = lookaheadset;
+ /* FIXME: Here, I need something like `bitset_disjoint_p'. */
+ for (j = 0; j < ntokens; ++j)
+ if (bitset_test (LA[state->lookaheadsp + i], j)
+ && bitset_test (lookaheadset, j))
+ conflicts[state->number] = 1;
- while (fp3 < fp4)
- {
- if (*fp2++ & *fp3++)
- {
- conflicts[state] = 1;
- any_conflicts = 1;
- }
- }
-
- fp2 = fp1;
- fp3 = lookaheadset;
-
- while (fp3 < fp4)
- *fp3++ |= *fp2++;
+ bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]);
}
}
void
-initialize_conflicts (void)
+solve_conflicts (void)
{
- int i;
+ size_t i;
- conflicts = NEW2 (nstates, char);
- shiftset = NEW2 (tokensetsize, unsigned);
- lookaheadset = NEW2 (tokensetsize, unsigned);
-
- err_table = NEW2 (nstates, errs *);
-
- any_conflicts = 0;
+ conflicts = XCALLOC (char, nstates);
+ shiftset = bitset_create (ntokens, BITSET_FIXED);
+ bitset_zero (shiftset);
+ lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+ bitset_zero (lookaheadset);
for (i = 0; i < nstates; i++)
- set_conflicts (i);
+ set_conflicts (states[i]);
}
| Count the number of shift/reduce conflicts. |
`---------------------------------------------*/
-static void
-count_sr_conflicts (int state)
+static int
+count_sr_conflicts (state_t *state)
{
int i;
- int k;
- int mask;
- shifts *shiftp;
- unsigned *fp1;
- unsigned *fp2;
- unsigned *fp3;
- int symbol;
-
- src_count = 0;
+ int src_count = 0;
+ shifts *shiftp = state->shifts;
- shiftp = shift_table[state];
if (!shiftp)
- return;
+ return 0;
- for (i = 0; i < tokensetsize; i++)
- {
- shiftset[i] = 0;
- lookaheadset[i] = 0;
- }
+ bitset_zero (lookaheadset);
+ bitset_zero (shiftset);
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- if (!shiftp->shifts[i])
- continue;
- symbol = accessing_symbol[shiftp->shifts[i]];
- if (ISVAR (symbol))
- break;
- SETBIT (shiftset, symbol);
- }
-
- k = lookaheads[state + 1];
- fp3 = lookaheadset + tokensetsize;
+ for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
+ if (!SHIFT_IS_DISABLED (shiftp, i))
+ bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i));
- for (i = lookaheads[state]; i < k; i++)
- {
- fp1 = LA + i * tokensetsize;
- fp2 = lookaheadset;
-
- while (fp2 < fp3)
- *fp2++ |= *fp1++;
- }
+ for (i = 0; i < state->nlookaheads; ++i)
+ bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]);
- fp1 = shiftset;
- fp2 = lookaheadset;
+ bitset_and (lookaheadset, lookaheadset, shiftset);
- while (fp2 < fp3)
- *fp2++ &= *fp1++;
-
- mask = 1;
- fp2 = lookaheadset;
for (i = 0; i < ntokens; i++)
- {
- if (mask & *fp2)
- src_count++;
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- fp2++;
- }
- }
+ if (bitset_test (lookaheadset, i))
+ src_count++;
+
+ return src_count;
}
| Count the number of reduce/reduce conflicts. |
`----------------------------------------------*/
-static void
-count_rr_conflicts (int state)
+static int
+count_rr_conflicts (state_t *state)
{
int i;
- int j;
- int count;
- unsigned mask;
- unsigned *baseword;
- unsigned *wordp;
- int m;
- int n;
-
- rrc_count = 0;
+ int rrc_count = 0;
- m = lookaheads[state];
- n = lookaheads[state + 1];
-
- if (n - m < 2)
- return;
+ if (state->nlookaheads < 2)
+ return 0;
- mask = 1;
- baseword = LA + m * tokensetsize;
for (i = 0; i < ntokens; i++)
{
- wordp = baseword;
-
- count = 0;
- for (j = m; j < n; j++)
- {
- if (mask & *wordp)
- count++;
-
- wordp += tokensetsize;
- }
+ int count = 0;
+ int j;
+ for (j = 0; j < state->nlookaheads; ++j)
+ if (bitset_test (LA[state->lookaheadsp + j], i))
+ count++;
if (count >= 2)
rrc_count++;
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- baseword++;
- }
}
+
+ return rrc_count;
}
-/*----------------------------------------------------------.
-| Output to OUT a human readable report on shift/reduce and |
-| reduce/reduce conflict numbers (SRC_NUM, RRC_NUM). |
-`----------------------------------------------------------*/
+/*--------------------------------------------------------------.
+| Return a human readable string which reports shift/reduce and |
+| reduce/reduce conflict numbers (SRC_NUM, RRC_NUM). |
+`--------------------------------------------------------------*/
-static void
-conflict_report (FILE *out, int src_num, int rrc_num)
+static const char *
+conflict_report (int src_num, int rrc_num)
{
- if (src_num == 1)
- fprintf (out, _(" 1 shift/reduce conflict"));
- else if (src_num > 1)
- fprintf (out, _(" %d shift/reduce conflicts"), src_num);
+ static char res[4096];
+ char *cp = res;
+
+ if (src_num >= 1)
+ {
+ sprintf (cp, ngettext ("%d shift/reduce conflict",
+ "%d shift/reduce conflicts", src_num), src_num);
+ cp += strlen (cp);
+ }
if (src_num > 0 && rrc_num > 0)
- fprintf (out, _(" and"));
+ {
+ sprintf (cp, " %s ", _("and"));
+ cp += strlen (cp);
+ }
+
+ if (rrc_num >= 1)
+ {
+ sprintf (cp, ngettext ("%d reduce/reduce conflict",
+ "%d reduce/reduce conflicts", rrc_num), rrc_num);
+ cp += strlen (cp);
+ }
- if (rrc_num == 1)
- fprintf (out, _(" 1 reduce/reduce conflict"));
- else if (rrc_num > 1)
- fprintf (out, _(" %d reduce/reduce conflicts"), rrc_num);
+ *cp++ = '.';
+ *cp++ = '\n';
+ *cp++ = '\0';
- putc ('.', out);
- putc ('\n', out);
+ return res;
}
-/*---------------------------------------------.
-| Compute and give a report on the conflicts. |
-`---------------------------------------------*/
+/*-----------------------------------------------------------.
+| Output the detailed description of states with conflicts. |
+`-----------------------------------------------------------*/
void
-print_conflicts (void)
+conflicts_output (FILE *out)
{
- int i;
+ bool printed_sth = FALSE;
+ size_t i;
+ for (i = 0; i < nstates; i++)
+ if (conflicts[i])
+ {
+ fprintf (out, _("State %d contains "), i);
+ fputs (conflict_report (count_sr_conflicts (states[i]),
+ count_rr_conflicts (states[i])), out);
+ printed_sth = TRUE;
+ }
+ if (printed_sth)
+ fputs ("\n\n", out);
+}
+
+
+/*------------------------------------------.
+| Reporting the total number of conflicts. |
+`------------------------------------------*/
- src_total = 0;
- rrc_total = 0;
+void
+conflicts_print (void)
+{
+ size_t i;
+
+ /* Is the number of SR conflicts OK? Either EXPECTED_CONFLICTS is
+ not set, and then we want 0 SR, or else it is specified, in which
+ case we want equality. */
+ int src_ok = 0;
- /* Count the total number of conflicts, and if wanted, give a
- detailed report in FOUTPUT. */
+ int src_total = 0;
+ int rrc_total = 0;
+
+ /* Conflicts by state. */
for (i = 0; i < nstates; i++)
- {
- if (conflicts[i])
- {
- count_sr_conflicts (i);
- count_rr_conflicts (i);
- src_total += src_count;
- rrc_total += rrc_count;
-
- if (verboseflag)
- {
- fprintf (foutput, _("State %d contains"), i);
- conflict_report (foutput, src_count, rrc_count);
- }
- }
- }
+ if (conflicts[i])
+ {
+ src_total += count_sr_conflicts (states[i]);
+ rrc_total += count_rr_conflicts (states[i]);
+ }
+
+ src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
+
+ /* If there are no RR conflicts, and as many SR conflicts as
+ expected, then there is nothing to report. */
+ if (!rrc_total && src_ok)
+ return;
/* Report the total number of conflicts on STDERR. */
- if (fixed_outfiles)
+ if (yacc_flag)
{
/* If invoked with `--yacc', use the output format specified by
POSIX. */
}
else
{
- fprintf (stderr, _("%s contains"), infile);
- conflict_report (stderr, src_total, rrc_total);
+ fprintf (stderr, _("%s contains "), infile);
+ fputs (conflict_report (src_total, rrc_total), stderr);
}
-}
-
-void
-print_reductions (int state)
-{
- int i;
- int j;
- int k;
- unsigned *fp1;
- unsigned *fp2;
- unsigned *fp3;
- unsigned *fp4;
- int rule;
- int symbol;
- unsigned mask;
- int m;
- int n;
- int default_LA;
- int default_rule = 0;
- int cmax;
- int count;
- shifts *shiftp;
- errs *errp;
- int nodefault = 0;
-
- for (i = 0; i < tokensetsize; i++)
- shiftset[i] = 0;
-
- shiftp = shift_table[state];
- if (shiftp)
- {
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- if (!shiftp->shifts[i])
- continue;
- symbol = accessing_symbol[shiftp->shifts[i]];
- 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)
- nodefault = 1;
- SETBIT (shiftset, symbol);
- }
- }
-
- errp = err_table[state];
- if (errp)
- {
- k = errp->nerrs;
- for (i = 0; i < k; i++)
- {
- if (!errp->errs[i])
- continue;
- symbol = errp->errs[i];
- SETBIT (shiftset, symbol);
- }
- }
-
- m = lookaheads[state];
- n = lookaheads[state + 1];
-
- if (n - m == 1 && !nodefault)
+ if (expected_conflicts != -1 && !src_ok)
{
- default_rule = LAruleno[m];
-
- fp1 = LA + m * tokensetsize;
- fp2 = shiftset;
- fp3 = lookaheadset;
- fp4 = lookaheadset + tokensetsize;
-
- while (fp3 < fp4)
- *fp3++ = *fp1++ & *fp2++;
-
- mask = 1;
- fp3 = lookaheadset;
-
- for (i = 0; i < ntokens; i++)
- {
- if (mask & *fp3)
- fprintf (foutput, _(" %-4s\t[reduce using rule %d (%s)]\n"),
- tags[i], default_rule, tags[rlhs[default_rule]]);
-
- mask <<= 1;
- if (mask == 0)
- {
- mask = 1;
- fp3++;
- }
- }
-
- fprintf (foutput, _(" $default\treduce using rule %d (%s)\n\n"),
- default_rule, tags[rlhs[default_rule]]);
- }
- else if (n - m >= 1)
- {
- cmax = 0;
- default_LA = -1;
- fp4 = lookaheadset + tokensetsize;
-
- if (!nodefault)
- for (i = m; i < n; i++)
- {
- fp1 = LA + i * tokensetsize;
- fp2 = shiftset;
- fp3 = lookaheadset;
-
- while (fp3 < fp4)
- *fp3++ = *fp1++ & (~(*fp2++));
-
- 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 (count > cmax)
- {
- cmax = count;
- default_LA = i;
- default_rule = LAruleno[i];
- }
-
- fp2 = shiftset;
- fp3 = lookaheadset;
-
- while (fp3 < fp4)
- *fp2++ |= *fp3++;
- }
-
- for (i = 0; i < tokensetsize; i++)
- shiftset[i] = 0;
-
- if (shiftp)
- {
- k = shiftp->nshifts;
- for (i = 0; i < k; i++)
- {
- if (!shiftp->shifts[i])
- continue;
- symbol = accessing_symbol[shiftp->shifts[i]];
- if (ISVAR (symbol))
- break;
- SETBIT (shiftset, symbol);
- }
- }
-
- mask = 1;
- fp1 = LA + m * tokensetsize;
- fp2 = shiftset;
- for (i = 0; i < ntokens; i++)
- {
- int defaulted = 0;
-
- if (mask & *fp2)
- count = 1;
- else
- count = 0;
-
- fp3 = fp1;
- for (j = m; j < n; j++)
- {
- if (mask & *fp3)
- {
- if (count == 0)
- {
- if (j != default_LA)
- {
- rule = LAruleno[j];
- fprintf (foutput,
- _(" %-4s\treduce using rule %d (%s)\n"),
- tags[i], rule, tags[rlhs[rule]]);
- }
- else
- defaulted = 1;
-
- count++;
- }
- else
- {
- if (defaulted)
- {
- rule = LAruleno[default_LA];
- fprintf (foutput,
- _(" %-4s\treduce using rule %d (%s)\n"),
- tags[i], rule, tags[rlhs[rule]]);
- defaulted = 0;
- }
- rule = LAruleno[j];
- fprintf (foutput,
- _(" %-4s\t[reduce using rule %d (%s)]\n"),
- tags[i], rule, tags[rlhs[rule]]);
- }
- }
-
- 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++;
- }
- }
-
- if (default_LA >= 0)
- {
- fprintf (foutput, _(" $default\treduce using rule %d (%s)\n"),
- default_rule, tags[rlhs[default_rule]]);
- }
-
- putc ('\n', foutput);
+ complain_message_count++;
+ fprintf (stderr, ngettext ("expected %d shift/reduce conflict\n",
+ "expected %d shift/reduce conflicts\n",
+ expected_conflicts),
+ expected_conflicts);
}
}
void
-finalize_conflicts (void)
+free_conflicts (void)
{
- FREE (conflicts);
- FREE (shiftset);
- FREE (lookaheadset);
+ XFREE (conflicts);
+ bitset_free (shiftset);
+ bitset_free (lookaheadset);
}
projects / bison.git / blobdiff