X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/aa7815f5c6e8e07a85e47df9cd7b579468969efb..ec3bc3961dd154cde7a14ce7e6b97b901af1dadb:/src/conflicts.c diff --git a/src/conflicts.c b/src/conflicts.c index 7606ff63..df3c931d 100644 --- a/src/conflicts.c +++ b/src/conflicts.c @@ -1,5 +1,6 @@ /* Find and resolve or report look-ahead conflicts for bison, - Copyright 1984, 1989, 1992, 2000 Free Software Foundation, Inc. + Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002 + Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -19,8 +20,10 @@ 02111-1307, USA. */ #include "system.h" +#include "bitset.h" +#include "complain.h" #include "getargs.h" -#include "xalloc.h" +#include "symtab.h" #include "files.h" #include "gram.h" #include "state.h" @@ -29,27 +32,25 @@ #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; static inline void -log_resolution (int state, int LAno, int token, char *resolution) +log_resolution (state_t *state, int LAno, int token, const char *resolution) { - if (verbose_flag) - fprintf (foutput, - _("\ + if (report_flag & report_states) + 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, + LArule[LAno]->number, + symbols[token]->tag, + resolution); } @@ -60,23 +61,28 @@ Conflict in state %d between rule %d and token %s resolved as %s.\n"), `------------------------------------------------------------------*/ 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); } @@ -88,197 +94,117 @@ flush_shift (int state, int 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 *) xcalloc (sizeof (errs) + ntokens * sizeof (short), 1); - short *errtokens = errp->errs; - /* find the rule to reduce by to get precedence of reduction */ - redprec = rprec[LAruleno[lookaheadnum]]; + int redprec = LArule[lookahead]->prec->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 *) xcalloc ((unsigned int) 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. */ + state->errs = errs_dup (errp); free (errp); } static void -set_conflicts (int state) +set_conflicts (state_t *state) { int i; - int k; 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; + bitset_zero (lookaheadset); - 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); - } - } - - 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]]) + for (i = 0; i < state->nlookaheads; ++i) + if (LArule[state->lookaheadsp + i]->prec + && LArule[state->lookaheadsp + i]->prec->prec + && !bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset)) { - fp1 = LA + i * tokensetsize; - fp2 = fp1; - fp3 = lookaheadset; - - while (fp3 < fp4) - { - 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; + if (!bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset)) + 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 = XCALLOC (char, nstates); - shiftset = XCALLOC (unsigned, tokensetsize); - lookaheadset = XCALLOC (unsigned, tokensetsize); - - err_table = XCALLOC (errs *, nstates); - - any_conflicts = 0; + shiftset = bitset_create (ntokens, BITSET_FIXED); + lookaheadset = bitset_create (ntokens, BITSET_FIXED); for (i = 0; i < nstates; i++) - set_conflicts (i); + set_conflicts (states[i]); } @@ -286,73 +212,31 @@ initialize_conflicts (void) | 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); - } + 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)); - k = lookaheads[state + 1]; - fp3 = lookaheadset + tokensetsize; + for (i = 0; i < state->nlookaheads; ++i) + bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]); - for (i = lookaheads[state]; i < k; i++) - { - fp1 = LA + i * tokensetsize; - fp2 = lookaheadset; - - while (fp2 < fp3) - *fp2++ |= *fp1++; - } + bitset_and (lookaheadset, lookaheadset, shiftset); - fp1 = shiftset; - fp2 = lookaheadset; + src_count = bitset_count (lookaheadset); - 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++; - } - } + return src_count; } @@ -360,109 +244,122 @@ count_sr_conflicts (int state) | 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); +} - src_total = 0; - rrc_total = 0; - /* Count the total number of conflicts, and if wanted, give a - detailed report in FOUTPUT. */ +/*------------------------------------------. +| Reporting the total number of conflicts. | +`------------------------------------------*/ + +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; + + 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 (verbose_flag) - { - 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 (yacc_flag) @@ -480,245 +377,25 @@ print_conflicts (void) } else { - fprintf (stderr, _("%s contains"), infile); - conflict_report (stderr, src_total, rrc_total); - } -} - - -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); - } + fprintf (stderr, _("%s contains "), infile); + fputs (conflict_report (src_total, rrc_total), stderr); } - 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) { XFREE (conflicts); - XFREE (shiftset); - XFREE (lookaheadset); + bitset_free (shiftset); + bitset_free (lookaheadset); }