X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/69363a9e4d0b8d3b51536434d3395d38519f617b..5422d56a718805a2470558808355e04182a12d65:/src/conflicts.c diff --git a/src/conflicts.c b/src/conflicts.c index 21ea7ce5..d8eddf0b 100644 --- a/src/conflicts.c +++ b/src/conflicts.c @@ -1,25 +1,24 @@ -/* Find and resolve or report look-ahead conflicts for bison, +/* Find and resolve or report lookahead conflicts for bison, - Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003 - Free Software Foundation, Inc. + Copyright (C) 1984, 1989, 1992, 2000-2007, 2009-2011 Free Software + Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. - Bison is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. - Bison is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with Bison; see the file COPYING. If not, write to the Free - Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA - 02111-1307, USA. */ + along with this program. If not, see . */ +#include #include "system.h" #include @@ -31,17 +30,20 @@ #include "getargs.h" #include "gram.h" #include "lalr.h" +#include "print-xml.h" #include "reader.h" #include "state.h" #include "symtab.h" /* -1 stands for not specified. */ -int expected_conflicts = -1; -static char *conflicts = NULL; -struct obstack solved_conflicts_obstack; +int expected_sr_conflicts = -1; +int expected_rr_conflicts = -1; +static char *conflicts; +static struct obstack solved_conflicts_obstack; +static struct obstack solved_conflicts_xml_obstack; -static bitset shiftset; -static bitset lookaheadset; +static bitset shift_set; +static bitset lookahead_set; @@ -72,23 +74,25 @@ log_resolution (rule *r, symbol_number token, case shift_resolution: case right_resolution: obstack_fgrow2 (&solved_conflicts_obstack, - _("\ - Conflict between rule %d and token %s resolved as shift"), + _(" Conflict between rule %d and token %s" + " resolved as shift"), r->number, symbols[token]->tag); break; + case reduce_resolution: case left_resolution: obstack_fgrow2 (&solved_conflicts_obstack, - _("\ - Conflict between rule %d and token %s resolved as reduce"), + _(" Conflict between rule %d and token %s" + " resolved as reduce"), r->number, symbols[token]->tag); break; + case nonassoc_resolution: obstack_fgrow2 (&solved_conflicts_obstack, - _("\ - Conflict between rule %d and token %s resolved as an error"), + _(" Conflict between rule %d and token %s" + " resolved as an error"), r->number, symbols[token]->tag); break; @@ -122,21 +126,95 @@ log_resolution (rule *r, symbol_number token, " (%%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"); } + + /* XML report */ + if (xml_flag) + { + /* The description of the resolution. */ + switch (resolution) + { + case shift_resolution: + case right_resolution: + obstack_fgrow2 (&solved_conflicts_xml_obstack, + " ", + r->number, + xml_escape (symbols[token]->tag)); + break; + + case reduce_resolution: + case left_resolution: + obstack_fgrow2 (&solved_conflicts_xml_obstack, + " ", + r->number, + xml_escape (symbols[token]->tag)); + break; + + case nonassoc_resolution: + obstack_fgrow2 (&solved_conflicts_xml_obstack, + " ", + r->number, + xml_escape (symbols[token]->tag)); + break; + } + + /* The reason. */ + switch (resolution) + { + case shift_resolution: + obstack_fgrow2 (&solved_conflicts_xml_obstack, + "%s < %s", + xml_escape_n (0, r->prec->tag), + xml_escape_n (1, symbols[token]->tag)); + break; + + case reduce_resolution: + obstack_fgrow2 (&solved_conflicts_xml_obstack, + "%s < %s", + xml_escape_n (0, symbols[token]->tag), + xml_escape_n (1, r->prec->tag)); + break; + + case left_resolution: + obstack_fgrow1 (&solved_conflicts_xml_obstack, + "%%left %s", + xml_escape (symbols[token]->tag)); + break; + + case right_resolution: + obstack_fgrow1 (&solved_conflicts_xml_obstack, + "%%right %s", + xml_escape (symbols[token]->tag)); + break; + + case nonassoc_resolution: + obstack_fgrow1 (&solved_conflicts_xml_obstack, + "%%nonassoc %s", + xml_escape (symbols[token]->tag)); + break; + } + + obstack_sgrow (&solved_conflicts_xml_obstack, "\n"); + } } /*------------------------------------------------------------------. | Turn off the shift recorded for the specified token in the | | specified state. Used when we resolve a shift-reduce conflict in | -| favor of the reduction. | +| favor of the reduction or as an error (%nonassoc). | `------------------------------------------------------------------*/ static void @@ -145,7 +223,7 @@ flush_shift (state *s, int token) transitions *trans = s->transitions; int i; - bitset_reset (lookaheadset, token); + bitset_reset (lookahead_set, token); for (i = 0; i < trans->num; i++) if (!TRANSITION_IS_DISABLED (trans, i) && TRANSITION_SYMBOL (trans, i) == token) @@ -153,16 +231,16 @@ flush_shift (state *s, int token) } -/*-------------------------------------------------------------------. -| 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. | -`-------------------------------------------------------------------*/ +/*--------------------------------------------------------------------. +| Turn off the reduce recorded for the specified token in the | +| specified lookahead set. Used when we resolve a shift-reduce | +| conflict in favor of the shift or as an error (%nonassoc). | +`--------------------------------------------------------------------*/ static void -flush_reduce (bitset lookaheads, int token) +flush_reduce (bitset lookahead_tokens, int token) { - bitset_reset (lookaheads, token); + bitset_reset (lookahead_tokens, token); } @@ -172,25 +250,25 @@ flush_reduce (bitset lookaheads, int token) | 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. | +| RULENO is the number of the lookahead bitset to consider. | | | -| ERRORS can be used to store discovered explicit errors. | +| ERRORS and NERRS can be used to store discovered explicit | +| errors. | `------------------------------------------------------------------*/ static void -resolve_sr_conflict (state *s, int ruleno, symbol **errors) +resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs) { symbol_number i; reductions *reds = s->reductions; /* Find the rule to reduce by to get precedence of reduction. */ rule *redrule = reds->rules[ruleno]; int redprec = redrule->prec->prec; - bitset lookaheads = reds->lookaheads[ruleno]; - int nerrs = 0; + bitset lookahead_tokens = reds->lookahead_tokens[ruleno]; for (i = 0; i < ntokens; i++) - if (bitset_test (lookaheads, i) - && bitset_test (lookaheadset, i) + if (bitset_test (lookahead_tokens, i) + && bitset_test (lookahead_set, i) && symbols[i]->prec) { /* Shift-reduce conflict occurs for token number i @@ -204,7 +282,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors) else if (symbols[i]->prec > redprec) { log_resolution (redrule, i, shift_resolution); - flush_reduce (lookaheads, i); + flush_reduce (lookahead_tokens, i); } else /* Matching precedence levels. @@ -214,9 +292,12 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors) switch (symbols[i]->assoc) { + default: + abort (); + case right_assoc: log_resolution (redrule, i, right_resolution); - flush_reduce (lookaheads, i); + flush_reduce (lookahead_tokens, i); break; case left_assoc: @@ -227,25 +308,12 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors) case non_assoc: log_resolution (redrule, i, nonassoc_resolution); flush_shift (s, i); - flush_reduce (lookaheads, i); + flush_reduce (lookahead_tokens, i); /* Record an explicit error for this token. */ - errors[nerrs++] = symbols[i]; + errors[(*nerrs)++] = symbols[i]; break; - - case undef_assoc: - abort (); } } - - /* Some tokens have been explicitly made errors. Allocate a - permanent errs structure for this state, to record them. */ - state_errs_set (s, nerrs, errors); - - if (obstack_object_size (&solved_conflicts_obstack)) - { - obstack_1grow (&solved_conflicts_obstack, '\0'); - s->solved_conflicts = obstack_finish (&solved_conflicts_obstack); - } } @@ -253,7 +321,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors) | Solve the S/R conflicts of state S using the | | precedence/associativity, and flag it inconsistent if it still has | | conflicts. ERRORS can be used as storage to compute the list of | -| lookaheads on which S raises a syntax error (%nonassoc). | +| lookahead tokens on which S raises a syntax error (%nonassoc). | `-------------------------------------------------------------------*/ static void @@ -262,34 +330,48 @@ set_conflicts (state *s, symbol **errors) int i; transitions *trans = s->transitions; reductions *reds = s->reductions; + int nerrs = 0; if (s->consistent) return; - bitset_zero (lookaheadset); + bitset_zero (lookahead_set); FOR_EACH_SHIFT (trans, i) - bitset_set (lookaheadset, TRANSITION_SYMBOL (trans, i)); + bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, 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 = 0; i < reds->num; ++i) if (reds->rules[i]->prec && reds->rules[i]->prec->prec - && !bitset_disjoint_p (reds->lookaheads[i], lookaheadset)) - { - resolve_sr_conflict (s, i, errors); - break; - } + && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set)) + resolve_sr_conflict (s, i, errors, &nerrs); + + if (nerrs) + { + /* Some tokens have been explicitly made errors. Allocate a + permanent errs structure for this state, to record them. */ + state_errs_set (s, nerrs, errors); + } + if (obstack_object_size (&solved_conflicts_obstack)) + { + obstack_1grow (&solved_conflicts_obstack, '\0'); + s->solved_conflicts = obstack_finish (&solved_conflicts_obstack); + } + if (obstack_object_size (&solved_conflicts_xml_obstack)) + { + obstack_1grow (&solved_conflicts_xml_obstack, '\0'); + s->solved_conflicts_xml = obstack_finish (&solved_conflicts_xml_obstack); + } /* Loop over all rules which require lookahead in this state. Check for conflicts not resolved above. */ for (i = 0; i < reds->num; ++i) { - if (!bitset_disjoint_p (reds->lookaheads[i], lookaheadset)) + if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set)) conflicts[s->number] = 1; - - bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]); + bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]); } } @@ -303,13 +385,14 @@ void conflicts_solve (void) { state_number i; - /* List of lookaheads on which we explicitly raise a syntax error. */ - symbol **errors = MALLOC (errors, ntokens + 1); + /* List of lookahead tokens on which we explicitly raise a syntax error. */ + symbol **errors = xnmalloc (ntokens + 1, sizeof *errors); - CALLOC (conflicts, nstates); - shiftset = bitset_create (ntokens, BITSET_FIXED); - lookaheadset = bitset_create (ntokens, BITSET_FIXED); + conflicts = xcalloc (nstates, sizeof *conflicts); + shift_set = bitset_create (ntokens, BITSET_FIXED); + lookahead_set = bitset_create (ntokens, BITSET_FIXED); obstack_init (&solved_conflicts_obstack); + obstack_init (&solved_conflicts_xml_obstack); for (i = 0; i < nstates; i++) { @@ -325,6 +408,17 @@ conflicts_solve (void) } +void +conflicts_update_state_numbers (state_number old_to_new[], + state_number nstates_old) +{ + state_number i; + for (i = 0; i < nstates_old; ++i) + if (old_to_new[i] != nstates_old) + conflicts[old_to_new[i]] = conflicts[i]; +} + + /*---------------------------------------------. | Count the number of shift/reduce conflicts. | `---------------------------------------------*/ @@ -340,18 +434,18 @@ count_sr_conflicts (state *s) if (!trans) return 0; - bitset_zero (lookaheadset); - bitset_zero (shiftset); + bitset_zero (lookahead_set); + bitset_zero (shift_set); FOR_EACH_SHIFT (trans, i) - bitset_set (shiftset, TRANSITION_SYMBOL (trans, i)); + bitset_set (shift_set, TRANSITION_SYMBOL (trans, i)); for (i = 0; i < reds->num; ++i) - bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]); + bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]); - bitset_and (lookaheadset, lookaheadset, shiftset); + bitset_and (lookahead_set, lookahead_set, shift_set); - src_count = bitset_count (lookaheadset); + src_count = bitset_count (lookahead_set); return src_count; } @@ -365,7 +459,7 @@ count_sr_conflicts (state *s) +`----------------------------------------------------------------*/ static int -count_rr_conflicts (state *s, int one_per_token) +count_rr_conflicts (state *s, bool one_per_token) { int i; reductions *reds = s->reductions; @@ -376,7 +470,7 @@ count_rr_conflicts (state *s, int one_per_token) int count = 0; int j; for (j = 0; j < reds->num; ++j) - if (bitset_test (reds->lookaheads[j], i)) + if (bitset_test (reds->lookahead_tokens[j], i)) count++; if (count >= 2) @@ -463,10 +557,13 @@ conflicts_print (void) /* 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; + bool src_ok; + bool rrc_ok; int src_total = 0; int rrc_total = 0; + int src_expected; + int rrc_expected; /* Conflicts by state. */ { @@ -480,27 +577,51 @@ conflicts_print (void) } } - src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts); + if (! glr_parser && rrc_total > 0 && expected_rr_conflicts != -1) + { + warn (_("%%expect-rr applies only to GLR parsers")); + expected_rr_conflicts = -1; + } + + src_expected = expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts; + rrc_expected = expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts; + src_ok = src_total == src_expected; + rrc_ok = rrc_total == rrc_expected; - /* If there are no RR conflicts, and as many SR conflicts as + /* If there are as many RR conflicts and SR conflicts as expected, then there is nothing to report. */ - if (!rrc_total && src_ok) + if (rrc_ok & src_ok) return; /* Report the total number of conflicts on STDERR. */ - if (! yacc_flag) - fprintf (stderr, "%s: ", current_file); - conflict_report (stderr, src_total, rrc_total); + if (expected_sr_conflicts == -1 && expected_rr_conflicts == -1) + { + if (!(warnings_flag & warnings_conflicts_sr)) + src_total = 0; + if (!(warnings_flag & warnings_conflicts_rr)) + rrc_total = 0; + } + if (src_total | rrc_total) + { + if (expected_sr_conflicts == -1 && expected_rr_conflicts == -1) + set_warning_issued (); + if (! yacc_flag) + fprintf (stderr, "%s: ", current_file); + conflict_report (stderr, src_total, rrc_total); + } - if (expected_conflicts != -1) + if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1) { if (! src_ok) - warn (ngettext ("expected %d shift/reduce conflict", - "expected %d shift/reduce conflicts", - expected_conflicts), - expected_conflicts); - if (rrc_total) - warn (_("expected 0 reduce/reduce conflicts")); + complain (ngettext ("expected %d shift/reduce conflict", + "expected %d shift/reduce conflicts", + src_expected), + src_expected); + if (! rrc_ok) + complain (ngettext ("expected %d reduce/reduce conflict", + "expected %d reduce/reduce conflicts", + rrc_expected), + rrc_expected); } } @@ -508,8 +629,9 @@ conflicts_print (void) void conflicts_free (void) { - XFREE (conflicts); - bitset_free (shiftset); - bitset_free (lookaheadset); + free (conflicts); + bitset_free (shift_set); + bitset_free (lookahead_set); obstack_free (&solved_conflicts_obstack, NULL); + obstack_free (&solved_conflicts_xml_obstack, NULL); }