X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/ec3bc3961dd154cde7a14ce7e6b97b901af1dadb..32e1e0a4865d64946a5497aff057d7be28c1cc3d:/src/conflicts.c diff --git a/src/conflicts.c b/src/conflicts.c index df3c931d..02876817 100644 --- a/src/conflicts.c +++ b/src/conflicts.c @@ -35,22 +35,98 @@ /* -1 stands for not specified. */ int expected_conflicts = -1; static char *conflicts = NULL; +struct obstack solved_conflicts_obstack; static bitset shiftset; static bitset lookaheadset; + +enum conflict_resolution_e + { + shift_resolution, + reduce_resolution, + left_resolution, + right_resolution, + nonassoc_resolution + }; + + +/*----------------------------------------------------------------. +| Explain how an SR conflict between TOKEN and RULE was resolved: | +| RESOLUTION. | +`----------------------------------------------------------------*/ + static inline void -log_resolution (state_t *state, int LAno, int token, const char *resolution) +log_resolution (rule_t *rule, int token, + enum conflict_resolution_e resolution) { - if (report_flag & report_states) - obstack_fgrow4 (&output_obstack, - _("\ -Conflict in state %d between rule %d and token %s resolved as %s.\n"), - state->number, - LArule[LAno]->number, - symbols[token]->tag, - resolution); + if (report_flag & report_solved_conflicts) + { + /* The description of the resolution. */ + switch (resolution) + { + case shift_resolution: + case left_resolution: + obstack_fgrow2 (&solved_conflicts_obstack, + _("\ + Conflict between rule %d and token %s resolved as shift"), + rule->number, + symbols[token]->tag); + break; + case reduce_resolution: + case right_resolution: + obstack_fgrow2 (&solved_conflicts_obstack, + _("\ + Conflict between rule %d and token %s resolved as reduce"), + 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"), + rule->number, + symbols[token]->tag); + break; + } + + /* The reason. */ + switch (resolution) + { + case shift_resolution: + obstack_fgrow2 (&solved_conflicts_obstack, + " (%s < %s)", + rule->prec->tag, + symbols[token]->tag); + break; + + case reduce_resolution: + obstack_fgrow2 (&solved_conflicts_obstack, + " (%s < %s)", + symbols[token]->tag, + rule->prec->tag); + break; + + case left_resolution: + obstack_fgrow1 (&solved_conflicts_obstack, + " (%%left %s)", + symbols[token]->tag); + break; + + case right_resolution: + obstack_fgrow1 (&solved_conflicts_obstack, + " (%%right %s)", + symbols[token]->tag); + break; + case nonassoc_resolution: + obstack_fgrow1 (&solved_conflicts_obstack, + " (%%nonassoc %s)", + symbols[token]->tag); + break; + } + obstack_sgrow (&solved_conflicts_obstack, ".\n"); + } } @@ -63,7 +139,7 @@ Conflict in state %d between rule %d and token %s resolved as %s.\n"), static void flush_shift (state_t *state, int token) { - shifts *shiftp = state->shifts; + shifts_t *shiftp = state->shifts; int i; bitset_reset (lookaheadset, token); @@ -80,9 +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); } @@ -91,19 +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) { @@ -112,13 +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 (state, lookahead, i, _("reduce")); + log_resolution (redrule, i, reduce_resolution); flush_shift (state, i); } else if (symbols[i]->prec > redprec) { - log_resolution (state, lookahead, i, _("shift")); - flush_reduce (lookahead, i); + log_resolution (redrule, i, shift_resolution); + flush_reduce (lookaheads, i); } else /* Matching precedence levels. @@ -129,22 +209,26 @@ resolve_sr_conflict (state_t *state, int lookahead) switch (symbols[i]->assoc) { case right_assoc: - log_resolution (state, lookahead, i, _("shift")); - flush_reduce (lookahead, i); + log_resolution (redrule, i, right_resolution); + flush_reduce (lookaheads, i); break; case left_assoc: - log_resolution (state, lookahead, i, _("reduce")); + log_resolution (redrule, i, left_resolution); flush_shift (state, i); break; case non_assoc: - log_resolution (state, lookahead, i, _("an error")); + 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; + + case undef_assoc: + assert (symbols[i]->assoc != undef_assoc); + break; } } @@ -152,6 +236,12 @@ resolve_sr_conflict (state_t *state, int lookahead) permanent errs structure for this state, to record them. */ state->errs = errs_dup (errp); free (errp); + + if (obstack_object_size (&solved_conflicts_obstack)) + { + obstack_1grow (&solved_conflicts_obstack, '\0'); + state->solved_conflicts = obstack_finish (&solved_conflicts_obstack); + } } @@ -159,7 +249,7 @@ static void set_conflicts (state_t *state) { int i; - shifts *shiftp; + shifts_t *shiftp; if (state->consistent) return; @@ -173,13 +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 (LArule[state->lookaheadsp + i]->prec - && LArule[state->lookaheadsp + i]->prec->prec - && !bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset)) + if (state->lookaheads_rule[i]->prec + && state->lookaheads_rule[i]->prec->prec + && !bitset_disjoint_p (state->lookaheads[i], lookaheadset)) { - resolve_sr_conflict (state, state->lookaheadsp + i); + resolve_sr_conflict (state, i); break; } @@ -187,21 +277,22 @@ set_conflicts (state_t *state) for conflicts not resolved above. */ for (i = 0; i < state->nlookaheads; ++i) { - if (!bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset)) + if (!bitset_disjoint_p (state->lookaheads[i], lookaheadset)) conflicts[state->number] = 1; - bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]); + bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]); } } void -solve_conflicts (void) +conflicts_solve (void) { - size_t i; + state_number_t i; conflicts = XCALLOC (char, nstates); shiftset = bitset_create (ntokens, BITSET_FIXED); lookaheadset = bitset_create (ntokens, BITSET_FIXED); + obstack_init (&solved_conflicts_obstack); for (i = 0; i < nstates; i++) set_conflicts (states[i]); @@ -217,7 +308,7 @@ count_sr_conflicts (state_t *state) { int i; int src_count = 0; - shifts *shiftp = state->shifts; + shifts_t *shiftp = state->shifts; if (!shiftp) return 0; @@ -230,7 +321,7 @@ count_sr_conflicts (state_t *state) bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i)); for (i = 0; i < state->nlookaheads; ++i) - bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]); + bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]); bitset_and (lookaheadset, lookaheadset, shiftset); @@ -240,12 +331,15 @@ count_sr_conflicts (state_t *state) } -/*----------------------------------------------. -| Count the number of reduce/reduce conflicts. | -`----------------------------------------------*/ +/*----------------------------------------------------------------. +| Count the number of reduce/reduce conflicts. If ONE_PER_TOKEN, | +| count one conflict for each token that has any reduce/reduce | +| conflicts. Otherwise, count one conflict for each pair of | +| conflicting reductions. | ++`----------------------------------------------------------------*/ static int -count_rr_conflicts (state_t *state) +count_rr_conflicts (state_t *state, int one_per_token) { int i; int rrc_count = 0; @@ -258,11 +352,11 @@ count_rr_conflicts (state_t *state) int count = 0; int j; for (j = 0; j < state->nlookaheads; ++j) - if (bitset_test (LA[state->lookaheadsp + j], i)) + if (bitset_test (state->lookaheads[j], i)) count++; if (count >= 2) - rrc_count++; + rrc_count += one_per_token ? 1 : count-1; } return rrc_count; @@ -315,19 +409,43 @@ void conflicts_output (FILE *out) { bool printed_sth = FALSE; - size_t i; + state_number_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); + count_rr_conflicts (states[i], TRUE)), out); printed_sth = TRUE; } if (printed_sth) fputs ("\n\n", out); } +/*--------------------------------------------------------. +| Total the number of S/R and R/R conflicts. Unlike the | +| code in conflicts_output, however, count EACH pair of | +| reductions for the same state and lookahead as one | +| conflict. | +`--------------------------------------------------------*/ + +int +conflicts_total_count (void) +{ + state_number_t i; + int count; + + /* Conflicts by state. */ + count = 0; + for (i = 0; i < nstates; i++) + if (conflicts[i]) + { + count += count_sr_conflicts (states[i]); + count += count_rr_conflicts (states[i], FALSE); + } + return count; +} + /*------------------------------------------. | Reporting the total number of conflicts. | @@ -336,8 +454,6 @@ conflicts_output (FILE *out) 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. */ @@ -347,12 +463,16 @@ conflicts_print (void) int rrc_total = 0; /* Conflicts by state. */ - for (i = 0; i < nstates; i++) - if (conflicts[i]) - { - src_total += count_sr_conflicts (states[i]); - rrc_total += count_rr_conflicts (states[i]); - } + { + state_number_t i; + + for (i = 0; i < nstates; i++) + if (conflicts[i]) + { + src_total += count_sr_conflicts (states[i]); + rrc_total += count_rr_conflicts (states[i], TRUE); + } + } src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts); @@ -393,9 +513,10 @@ conflicts_print (void) void -free_conflicts (void) +conflicts_free (void) { XFREE (conflicts); bitset_free (shiftset); bitset_free (lookaheadset); + obstack_free (&solved_conflicts_obstack, NULL); }