X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/f59c437a25af1e4c028d268cca3819476ef4f725..709ae8c6ee619a2bf89a26ddd7575bdeb5d1896f:/src/conflicts.c diff --git a/src/conflicts.c b/src/conflicts.c index 2ca3cff8..cbd002d5 100644 --- a/src/conflicts.c +++ b/src/conflicts.c @@ -29,7 +29,6 @@ #include "reader.h" #include "LR0.h" -errs **err_table = NULL; /* -1 stands for not specified. */ int expected_conflicts = -1; static char *conflicts = NULL; @@ -41,10 +40,11 @@ static unsigned *lookaheadset = 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); } @@ -57,21 +57,26 @@ Conflict in state %d between rule %d and token %s resolved as %s.\n"), 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); } @@ -83,98 +88,66 @@ flush_shift (int state, int 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); } @@ -182,75 +155,47 @@ resolve_sr_conflict (int state, int lookaheadnum) static void set_conflicts (int state) { - int i; - int k; + int i, j; shifts *shiftp; - unsigned *fp2; - unsigned *fp3; - unsigned *fp4; - unsigned *fp1; - 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) - { - k = shiftp->nshifts; - for (i = 0; i < k; i++) - { - symbol = state_table[shiftp->shifts[i]].accessing_symbol; - if (ISVAR (symbol)) - break; - SETBIT (lookaheadset, symbol); - } - } - - k = state_table[state + 1].lookaheads; - fp4 = lookaheadset + tokensetsize; + 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 < k; i++) + for (i = state_table[state]->lookaheads; + i < state_table[state + 1]->lookaheads; + ++i) if (rule_table[LAruleno[i]].prec) - { - fp1 = LA (i); - fp2 = fp1; - fp3 = lookaheadset; - - while (fp3 < fp4) + for (j = 0; j < tokensetsize; ++j) + if (LA (i)[j] & lookaheadset[j]) { - if (*fp2++ & *fp3++) - { - resolve_sr_conflict (state, i); - break; - } + resolve_sr_conflict (state, i); + break; } - } /* Loop over all rules which require lookahead in this state. Check for conflicts not resolved above. */ - for (i = state_table[state].lookaheads; i < k; i++) + for (i = state_table[state]->lookaheads; + i < state_table[state + 1]->lookaheads; + ++i) { - fp1 = LA (i); - fp2 = fp1; - fp3 = lookaheadset; - - while (fp3 < fp4) - if (*fp2++ & *fp3++) + for (j = 0; j < tokensetsize; ++j) + if (LA (i)[j] & lookaheadset[j]) conflicts[state] = 1; - fp2 = fp1; - fp3 = lookaheadset; - - while (fp3 < fp4) - *fp3++ |= *fp2++; + for (j = 0; j < tokensetsize; ++j) + lookaheadset[j] |= LA (i)[j]; } } @@ -263,8 +208,6 @@ solve_conflicts (void) shiftset = XCALLOC (unsigned, tokensetsize); lookaheadset = XCALLOC (unsigned, tokensetsize); - err_table = XCALLOC (errs *, nstates); - for (i = 0; i < nstates; i++) set_conflicts (i); } @@ -277,18 +220,10 @@ solve_conflicts (void) 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; @@ -298,49 +233,22 @@ count_sr_conflicts (int state) 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 = state_table[state].lookaheads; i < k; i++) - { - fp1 = LA (i); - fp2 = lookaheadset; - - while (fp2 < fp3) - *fp2++ |= *fp1++; - } + for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++) + if (!SHIFT_IS_DISABLED (shiftp, i)) + SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i)); - 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; } @@ -354,42 +262,24 @@ static int 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; @@ -441,6 +331,7 @@ conflict_report (int src_num, int rrc_num) void conflicts_output (FILE *out) { + bool printed_sth = FALSE; int i; for (i = 0; i < nstates; i++) if (conflicts[i]) @@ -448,7 +339,10 @@ conflicts_output (FILE *out) fprintf (out, _("State %d contains "), i); fputs (conflict_report (count_sr_conflicts (i), count_rr_conflicts (i)), out); + printed_sth = TRUE; } + if (printed_sth) + fputs ("\n\n", out); } @@ -461,6 +355,11 @@ conflicts_print (void) { int 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; + int src_total = 0; int rrc_total = 0; @@ -472,35 +371,38 @@ conflicts_print (void) rrc_total += count_rr_conflicts (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 (src_total || rrc_total) + if (yacc_flag) { - if (yacc_flag) - { - /* If invoked with `--yacc', use the output format specified by - POSIX. */ - fprintf (stderr, _("conflicts: ")); - if (src_total > 0) - fprintf (stderr, _(" %d shift/reduce"), src_total); - if (src_total > 0 && rrc_total > 0) - fprintf (stderr, ","); - if (rrc_total > 0) - fprintf (stderr, _(" %d reduce/reduce"), rrc_total); - putc ('\n', stderr); - } - else - { - fprintf (stderr, _("%s contains "), infile); - fputs (conflict_report (src_total, rrc_total), stderr); - } + /* If invoked with `--yacc', use the output format specified by + POSIX. */ + fprintf (stderr, _("conflicts: ")); + if (src_total > 0) + fprintf (stderr, _(" %d shift/reduce"), src_total); + if (src_total > 0 && rrc_total > 0) + fprintf (stderr, ","); + if (rrc_total > 0) + fprintf (stderr, _(" %d reduce/reduce"), rrc_total); + putc ('\n', stderr); + } + else + { + fprintf (stderr, _("%s contains "), infile); + fputs (conflict_report (src_total, rrc_total), stderr); } - if (expected_conflicts != -1 - && src_total != expected_conflicts) + if (expected_conflicts != -1 && !src_ok) { complain_message_count++; - fprintf (stderr, ngettext ("expected %d shift/reduce conflict", - "expected %d shift/reduce conflicts", + fprintf (stderr, ngettext ("expected %d shift/reduce conflict\n", + "expected %d shift/reduce conflicts\n", expected_conflicts), expected_conflicts); } @@ -512,20 +414,8 @@ print_reductions (FILE *out, 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; @@ -533,105 +423,62 @@ print_reductions (FILE *out, int state) for (i = 0; i < tokensetsize; i++) shiftset[i] = 0; - shiftp = state_table[state].shift_table; - if (shiftp) - { - 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; - /* 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); - } - } + shiftp = state_table[state]->shifts; + for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++) + if (!SHIFT_IS_DISABLED (shiftp, i)) + { + /* 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, SHIFT_SYMBOL (shiftp, i)); + } - errp = err_table[state]; + errp = state_table[state]->errs; if (errp) - { - k = errp->nerrs; - for (i = 0; i < k; i++) - { - if (!errp->errs[i]) - continue; - symbol = errp->errs[i]; - SETBIT (shiftset, symbol); - } - } + for (i = 0; i < errp->nerrs; i++) + if (errp->errs[i]) + SETBIT (shiftset, errp->errs[i]); - m = state_table[state].lookaheads; - n = state_table[state + 1].lookaheads; + m = state_table[state]->lookaheads; + n = state_table[state + 1]->lookaheads; if (n - m == 1 && !nodefault) { - default_rule = LAruleno[m]; + int k; + int default_rule = LAruleno[m]; - fp1 = LA (m); - fp2 = shiftset; - fp3 = lookaheadset; - fp4 = lookaheadset + tokensetsize; - - while (fp3 < fp4) - *fp3++ = *fp1++ & *fp2++; - - mask = 1; - fp3 = lookaheadset; + for (k = 0; k < tokensetsize; ++k) + lookaheadset[k] = LA (m)[k] & shiftset[k]; for (i = 0; i < ntokens; i++) - { - if (mask & *fp3) - fprintf (out, _(" %-4s\t[reduce using rule %d (%s)]\n"), - tags[i], default_rule, - tags[rule_table[default_rule].lhs]); - - mask <<= 1; - if (mask == 0) - { - mask = 1; - fp3++; - } - } + if (BITISSET (lookaheadset, i)) + fprintf (out, _(" %-4s\t[reduce using rule %d (%s)]\n"), + tags[i], default_rule, + tags[rule_table[default_rule].lhs]); fprintf (out, _(" $default\treduce using rule %d (%s)\n\n"), default_rule, tags[rule_table[default_rule].lhs]); } else if (n - m >= 1) { - cmax = 0; - default_LA = -1; - fp4 = lookaheadset + tokensetsize; + int k; + + 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) { @@ -640,56 +487,34 @@ print_reductions (FILE *out, int state) 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) - { - 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); - } - } + 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) { if (j != default_LA) - { - rule = LAruleno[j]; - fprintf (out, - _(" %-4s\treduce using rule %d (%s)\n"), - tags[i], rule, tags[rule_table[rule].lhs]); - } + fprintf (out, + _(" %-4s\treduce using rule %d (%s)\n"), + tags[i], + LAruleno[j], + tags[rule_table[LAruleno[j]].lhs]); else defaulted = 1; @@ -698,31 +523,19 @@ print_reductions (FILE *out, int state) else { if (defaulted) - { - rule = LAruleno[default_LA]; - fprintf (out, - _(" %-4s\treduce using rule %d (%s)\n"), - tags[i], rule, tags[rule_table[rule].lhs]); - defaulted = 0; - } - rule = LAruleno[j]; + fprintf (out, + _(" %-4s\treduce using rule %d (%s)\n"), + tags[i], + LAruleno[default_LA], + tags[rule_table[LAruleno[default_LA]].lhs]); + defaulted = 0; fprintf (out, _(" %-4s\t[reduce using rule %d (%s)]\n"), - tags[i], rule, tags[rule_table[rule].lhs]); + tags[i], + LAruleno[j], + 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++; } }