X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/ff5c8b85578372911e9c382ce91112058308b4ef..bb8e56ff67d289d15f1a4dc7f5e1502cd3bbfc24:/src/tables.c diff --git a/src/tables.c b/src/tables.c index 1e65e365..96354b1a 100644 --- a/src/tables.c +++ b/src/tables.c @@ -1,30 +1,27 @@ /* Output the generated parsing program for Bison. - Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002 - Free Software Foundation, Inc. + Copyright (C) 1984, 1986, 1989, 1992, 2000-2006, 2009-2012 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 -#include #include "complain.h" #include "conflicts.h" @@ -32,6 +29,7 @@ #include "getargs.h" #include "gram.h" #include "lalr.h" +#include "muscle-tab.h" #include "reader.h" #include "symtab.h" #include "tables.h" @@ -42,18 +40,20 @@ Of course vector_number_t ought to be wide enough to contain state_number and symbol_number. */ -typedef short vector_number; +typedef int vector_number; +#if 0 /* Not currently used. */ static inline vector_number state_number_to_vector_number (state_number s) { return s; } +#endif static inline vector_number -symbol_number_to_vector_number (symbol_number s) +symbol_number_to_vector_number (symbol_number sym) { - return state_number_as_int (nstates) + s - ntokens; + return state_number_as_int (nstates) + sym - ntokens; } int nvectors; @@ -81,11 +81,11 @@ int nvectors; #define BASE_MAXIMUM INT_MAX #define BASE_MINIMUM INT_MIN -static base_number **froms = NULL; -static base_number **tos = NULL; -static unsigned int **conflict_tos = NULL; -static short *tally = NULL; -static base_number *width = NULL; +static base_number **froms; +static base_number **tos; +static unsigned int **conflict_tos; +static int *tally; +static base_number *width; /* For a given state, N = ACTROW[SYMBOL]: @@ -94,15 +94,15 @@ static base_number *width = NULL; If N = MIN, stands for `raise a syntax error'. If N > 0, stands for `shift SYMBOL and go to n'. If N < 0, stands for `reduce -N'. */ -typedef short action_number; -#define ACTION_NUMBER_MINIMUM SHRT_MIN +typedef int action_number; +#define ACTION_NUMBER_MINIMUM INT_MIN -static action_number *actrow = NULL; +static action_number *actrow; /* FROMS and TOS are reordered to be compressed. ORDER[VECTOR] is the new vector number of VECTOR. We skip `empty' vectors (i.e., TALLY[VECTOR] = 0), and call these `entries'. */ -static vector_number *order = NULL; +static vector_number *order; static int nentries; base_number *base = NULL; @@ -112,9 +112,9 @@ base_number *base = NULL; base_number base_ninf = 0; static base_number *pos = NULL; -static unsigned int *conflrow = NULL; -unsigned int *conflict_table = NULL; -unsigned int *conflict_list = NULL; +static unsigned int *conflrow; +unsigned int *conflict_table; +unsigned int *conflict_list; int conflict_list_cnt; static int conflict_list_free; @@ -122,10 +122,10 @@ static int conflict_list_free; with more or less the original hard-coded value (which was SHRT_MAX). */ static int table_size = 32768; -base_number *table = NULL; -base_number *check = NULL; +base_number *table; +base_number *check; /* The value used in TABLE to denote explicit syntax errors - (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MININUM, + (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MINIMUM, but in order to keep small tables, renumbered as TABLE_ERROR, which is the smallest (non error) value minus 1. */ base_number table_ninf = 0; @@ -151,15 +151,17 @@ table_grow (int desired) if (trace_flag & trace_resource) fprintf (stderr, "growing table and check from: %d to %d\n", - old_size, table_size); + old_size, table_size); - REALLOC (table, table_size); - REALLOC (check, table_size); - REALLOC (conflict_table, table_size); + table = xnrealloc (table, table_size, sizeof *table); + conflict_table = xnrealloc (conflict_table, table_size, + sizeof *conflict_table); + check = xnrealloc (check, table_size, sizeof *check); for (/* Nothing. */; old_size < table_size; ++old_size) { table[old_size] = 0; + conflict_table[old_size] = 0; check[old_size] = -1; } } @@ -169,12 +171,12 @@ table_grow (int desired) /*-------------------------------------------------------------------. | For GLR parsers, for each conflicted token in S, as indicated | -| by non-zero entries in CONFLROW, create a list of possible | -| reductions that are alternatives to the shift or reduction | +| by non-zero entries in CONFLROW, create a list of possible | +| reductions that are alternatives to the shift or reduction | | currently recorded for that token in S. Store the alternative | -| reductions followed by a 0 in CONFLICT_LIST, updating | +| reductions followed by a 0 in CONFLICT_LIST, updating | | CONFLICT_LIST_CNT, and storing an index to the start of the list | -| back into CONFLROW. | +| back into CONFLROW. | `-------------------------------------------------------------------*/ static void @@ -183,46 +185,45 @@ conflict_row (state *s) int i, j; reductions *reds = s->reductions; - if (! glr_parser) + if (!nondeterministic_parser) return; for (j = 0; j < ntokens; j += 1) if (conflrow[j]) { - conflrow[j] = conflict_list_cnt; - - /* Find all reductions for token J, and record all that do not - match ACTROW[J]. */ - for (i = 0; i < reds->num; i += 1) - if (bitset_test (reds->lookaheads[i], j) - && (actrow[j] - != rule_number_as_item_number (reds->rules[i]->number))) - { - if (conflict_list_free <= 0) - abort (); - conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1; - conflict_list_cnt += 1; - conflict_list_free -= 1; - } - - /* Leave a 0 at the end. */ - if (conflict_list_free <= 0) - abort (); - conflict_list_cnt += 1; - conflict_list_free -= 1; + conflrow[j] = conflict_list_cnt; + + /* Find all reductions for token J, and record all that do not + match ACTROW[J]. */ + for (i = 0; i < reds->num; i += 1) + if (bitset_test (reds->lookahead_tokens[i], j) + && (actrow[j] + != rule_number_as_item_number (reds->rules[i]->number))) + { + aver (0 < conflict_list_free); + conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1; + conflict_list_cnt += 1; + conflict_list_free -= 1; + } + + /* Leave a 0 at the end. */ + aver (0 < conflict_list_free); + conflict_list[conflict_list_cnt] = 0; + conflict_list_cnt += 1; + conflict_list_free -= 1; } } /*------------------------------------------------------------------. -| Decide what to do for each type of token if seen as the lookahead | -| token in specified state. The value returned is used as the | +| Decide what to do for each type of token if seen as the | +| lookahead in specified state. The value returned is used as the | | default action (yydefact) for the state. In addition, ACTROW is | | filled with what to do for each kind of token, index by symbol | | number, with zero meaning do the default action. The value | -| ACTION_NUMBER_MINIMUM, a very negative number, means this | -| situation is an error. The parser recognizes this value | -| specially. | +| ACTION_NUMBER_MINIMUM, a very negative number, means this | +| situation is an error. The parser recognizes this value | +| specially. | | | | This is where conflicts are resolved. The loop over lookahead | | rules considered lower-numbered rules last, and the last rule | @@ -238,35 +239,38 @@ static rule * action_row (state *s) { int i; - rule *default_rule = NULL; + rule *default_reduction = NULL; reductions *reds = s->reductions; transitions *trans = s->transitions; errs *errp = s->errs; /* Set to nonzero to inhibit having any default reduction. */ - int nodefault = 0; - int conflicted = 0; + bool nodefault = false; + bool conflicted = false; for (i = 0; i < ntokens; i++) actrow[i] = conflrow[i] = 0; - if (reds->lookaheads) + if (reds->lookahead_tokens) { int j; bitset_iterator biter; /* loop over all the rules available here which require - lookahead (in reverse order to give precedence to the first - rule) */ + lookahead (in reverse order to give precedence to the first + rule) */ for (i = reds->num - 1; i >= 0; --i) - /* and find each token which the rule finds acceptable - to come next */ - BITSET_FOR_EACH (biter, reds->lookaheads[i], j, 0) - { - /* and record this rule as the rule to use if that - token follows. */ - if (actrow[j] != 0) - conflicted = conflrow[j] = 1; - actrow[j] = rule_number_as_item_number (reds->rules[i]->number); - } + /* and find each token which the rule finds acceptable + to come next */ + BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0) + { + /* and record this rule as the rule to use if that + token follows. */ + if (actrow[j] != 0) + { + conflicted = true; + conflrow[j] = 1; + } + actrow[j] = rule_number_as_item_number (reds->rules[i]->number); + } } /* Now see which tokens are allowed for shifts in this state. For @@ -278,13 +282,16 @@ action_row (state *s) state *shift_state = trans->states[i]; if (actrow[sym] != 0) - conflicted = conflrow[sym] = 1; + { + conflicted = true; + conflrow[sym] = 1; + } actrow[sym] = state_number_as_int (shift_state->number); /* Do not use any default reduction if there is a shift for - error */ + error */ if (sym == errtoken->number) - nodefault = 1; + nodefault = true; } /* See which tokens are an explicit error in this state (due to @@ -296,62 +303,74 @@ action_row (state *s) actrow[sym->number] = ACTION_NUMBER_MINIMUM; } + /* Turn off default reductions where requested by the user. See + state_lookahead_tokens_count in lalr.c to understand when states are + labeled as consistent. */ + { + char *default_reductions = + muscle_percent_define_get ("lr.default-reductions"); + if (STRNEQ (default_reductions, "most") && !s->consistent) + nodefault = true; + free (default_reductions); + } + /* Now find the most common reduction and make it the default action for this state. */ if (reds->num >= 1 && !nodefault) { if (s->consistent) - default_rule = reds->rules[0]; + default_reduction = reds->rules[0]; else - { - int max = 0; - for (i = 0; i < reds->num; i++) - { - int count = 0; - rule *r = reds->rules[i]; - symbol_number j; - - for (j = 0; j < ntokens; j++) - if (actrow[j] == rule_number_as_item_number (r->number)) - count++; - - if (count > max) - { - max = count; - default_rule = r; - } - } - - /* GLR parsers need space for conflict lists, so we can't - default conflicted entries. For non-conflicted entries - or as long as we are not building a GLR parser, - actions that match the default are replaced with zero, - which means "use the default". */ - - if (max > 0) - { - int j; - for (j = 0; j < ntokens; j++) - if (actrow[j] == rule_number_as_item_number (default_rule->number) - && ! (glr_parser && conflrow[j])) - actrow[j] = 0; - } - } + { + int max = 0; + for (i = 0; i < reds->num; i++) + { + int count = 0; + rule *r = reds->rules[i]; + symbol_number j; + + for (j = 0; j < ntokens; j++) + if (actrow[j] == rule_number_as_item_number (r->number)) + count++; + + if (count > max) + { + max = count; + default_reduction = r; + } + } + + /* GLR parsers need space for conflict lists, so we can't + default conflicted entries. For non-conflicted entries + or as long as we are not building a GLR parser, + actions that match the default are replaced with zero, + which means "use the default". */ + + if (max > 0) + { + int j; + for (j = 0; j < ntokens; j++) + if (actrow[j] + == rule_number_as_item_number (default_reduction->number) + && ! (nondeterministic_parser && conflrow[j])) + actrow[j] = 0; + } + } } - /* If have no default rule, the default is an error. + /* If have no default reduction, the default is an error. So replace any action which says "error" with "use default". */ - if (!default_rule) + if (!default_reduction) for (i = 0; i < ntokens; i++) if (actrow[i] == ACTION_NUMBER_MINIMUM) - actrow[i] = 0; + actrow[i] = 0; if (conflicted) conflict_row (s); - return default_rule; + return default_reduction; } @@ -367,7 +386,7 @@ save_row (state_number s) base_number *sp; base_number *sp1; base_number *sp2; - unsigned int *sp3 IF_LINT (= NULL); + unsigned int *sp3; /* Number of non default actions in S. */ count = 0; @@ -379,18 +398,19 @@ save_row (state_number s) return; /* Allocate non defaulted actions. */ - froms[s] = sp = CALLOC (sp1, count); - tos[s] = CALLOC (sp2, count); - conflict_tos[s] = glr_parser ? CALLOC (sp3, count) : NULL; + froms[s] = sp = sp1 = xnmalloc (count, sizeof *sp1); + tos[s] = sp2 = xnmalloc (count, sizeof *sp2); + conflict_tos[s] = sp3 = + nondeterministic_parser ? xnmalloc (count, sizeof *sp3) : NULL; /* Store non defaulted actions. */ for (i = 0; i < ntokens; i++) if (actrow[i] != 0) { - *sp1++ = i; - *sp2++ = actrow[i]; - if (glr_parser) - *sp3++ = conflrow[i]; + *sp1++ = i; + *sp2++ = actrow[i]; + if (nondeterministic_parser) + *sp3++ = conflrow[i]; } tally[s] = count; @@ -413,39 +433,39 @@ token_actions (void) symbol_number j; rule_number r; - int nconflict = glr_parser ? conflicts_total_count () : 0; + int nconflict = nondeterministic_parser ? conflicts_total_count () : 0; - CALLOC (yydefact, nstates); + yydefact = xnmalloc (nstates, sizeof *yydefact); - CALLOC (actrow, ntokens); - CALLOC (conflrow, ntokens); + actrow = xnmalloc (ntokens, sizeof *actrow); + conflrow = xnmalloc (ntokens, sizeof *conflrow); - CALLOC (conflict_list, 1 + 2 * nconflict); + conflict_list = xnmalloc (1 + 2 * nconflict, sizeof *conflict_list); conflict_list_free = 2 * nconflict; conflict_list_cnt = 1; /* Find the rules which are reduced. */ - if (!glr_parser) + if (!nondeterministic_parser) for (r = 0; r < nrules; ++r) rules[r].useful = false; for (i = 0; i < nstates; ++i) { - rule *default_rule = action_row (states[i]); - yydefact[i] = default_rule ? default_rule->number + 1 : 0; + rule *default_reduction = action_row (states[i]); + yydefact[i] = default_reduction ? default_reduction->number + 1 : 0; save_row (i); /* Now that the parser was computed, we can find which rules are - really reduced, and which are not because of SR or RR - conflicts. */ - if (!glr_parser) - { - for (j = 0; j < ntokens; ++j) - if (actrow[j] < 0 && actrow[j] != ACTION_NUMBER_MINIMUM) - rules[item_number_as_rule_number (actrow[j])].useful = true; - if (yydefact[i]) - rules[yydefact[i] - 1].useful = true; - } + really reduced, and which are not because of SR or RR + conflicts. */ + if (!nondeterministic_parser) + { + for (j = 0; j < ntokens; ++j) + if (actrow[j] < 0 && actrow[j] != ACTION_NUMBER_MINIMUM) + rules[item_number_as_rule_number (actrow[j])].useful = true; + if (yydefact[i]) + rules[yydefact[i] - 1].useful = true; + } } free (actrow); @@ -465,7 +485,7 @@ token_actions (void) static void save_column (symbol_number sym, state_number default_state) { - int i; + goto_number i; base_number *sp; base_number *sp1; base_number *sp2; @@ -485,15 +505,15 @@ save_column (symbol_number sym, state_number default_state) return; /* Allocate room for non defaulted gotos. */ - froms[symno] = sp = CALLOC (sp1, count); - tos[symno] = CALLOC (sp2, count); + froms[symno] = sp = sp1 = xnmalloc (count, sizeof *sp1); + tos[symno] = sp2 = xnmalloc (count, sizeof *sp2); /* Store the state numbers of the non defaulted gotos. */ for (i = begin; i < end; i++) if (to_state[i] != default_state) { - *sp1++ = from_state[i]; - *sp2++ = to_state[i]; + *sp1++ = from_state[i]; + *sp2++ = to_state[i]; } tally[symno] = count; @@ -506,14 +526,14 @@ save_column (symbol_number sym, state_number default_state) `-------------------------------------------------------------*/ static state_number -default_goto (symbol_number sym, short state_count[]) +default_goto (symbol_number sym, size_t state_count[]) { state_number s; - int i; + goto_number i; goto_number m = goto_map[sym - ntokens]; goto_number n = goto_map[sym - ntokens + 1]; state_number default_state = -1; - int max = 0; + size_t max = 0; if (m == n) return -1; @@ -527,8 +547,8 @@ default_goto (symbol_number sym, short state_count[]) for (s = 0; s < nstates; s++) if (state_count[s] > max) { - max = state_count[s]; - default_state = s; + max = state_count[s]; + default_state = s; } return default_state; @@ -548,8 +568,8 @@ static void goto_actions (void) { symbol_number i; - short *state_count = CALLOC (state_count, nstates); - MALLOC (yydefgoto, nvars); + size_t *state_count = xnmalloc (nstates, sizeof *state_count); + yydefgoto = xnmalloc (nvars, sizeof *yydefgoto); /* For a given nterm I, STATE_COUNT[S] is the number of times there is a GOTO to S on I. */ @@ -578,22 +598,22 @@ sort_actions (void) for (i = 0; i < nvectors; i++) if (tally[i] > 0) { - int k; - int t = tally[i]; - int w = width[i]; - int j = nentries - 1; + int k; + int t = tally[i]; + int w = width[i]; + int j = nentries - 1; - while (j >= 0 && (width[order[j]] < w)) - j--; + while (j >= 0 && (width[order[j]] < w)) + j--; - while (j >= 0 && (width[order[j]] == w) && (tally[order[j]] < t)) - j--; + while (j >= 0 && (width[order[j]] == w) && (tally[order[j]] < t)) + j--; - for (k = nentries - 1; k > j; k--) - order[k + 1] = order[k]; + for (k = nentries - 1; k > j; k--) + order[k + 1] = order[k]; - order[j + 1] = i; - nentries++; + order[j + 1] = i; + nentries++; } } @@ -624,8 +644,8 @@ matching_state (vector_number vector) { int j; for (j = 0; j < t; j += 1) - if (conflict_tos[i][j] != 0) - return -1; + if (conflict_tos[i][j] != 0) + return -1; } for (prev = vector - 1; prev >= 0; prev--) @@ -635,17 +655,17 @@ matching_state (vector_number vector) int match = 1; /* Given how ORDER was computed, if the WIDTH or TALLY is - different, there cannot be a matching state. */ + different, there cannot be a matching state. */ if (width[j] != w || tally[j] != t) - return -1; + return -1; for (k = 0; match && k < t; k++) - if (tos[j][k] != tos[i][k] || froms[j][k] != froms[i][k] - || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0)) - match = 0; + if (tos[j][k] != tos[i][k] || froms[j][k] != froms[i][k] + || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0)) + match = 0; if (match) - return j; + return j; } return -1; @@ -663,52 +683,49 @@ pack_vector (vector_number vector) base_number *to = tos[i]; unsigned int *conflict_to = conflict_tos[i]; - if (! t) - abort (); + aver (t != 0); for (j = lowzero - from[0]; ; j++) { int k; - int ok = 1; + bool ok = true; - if (table_size <= j) - abort (); + aver (j < table_size); for (k = 0; ok && k < t; k++) - { - loc = j + state_number_as_int (from[k]); - if (table_size <= loc) - table_grow (loc); + { + loc = j + state_number_as_int (from[k]); + if (table_size <= loc) + table_grow (loc); - if (table[loc] != 0) - ok = 0; - } + if (table[loc] != 0) + ok = false; + } for (k = 0; ok && k < vector; k++) - if (pos[k] == j) - ok = 0; + if (pos[k] == j) + ok = false; if (ok) - { - for (k = 0; k < t; k++) - { - loc = j + from[k]; - table[loc] = to[k]; - if (glr_parser && conflict_to != NULL) - conflict_table[loc] = conflict_to[k]; - check[loc] = from[k]; - } - - while (table[lowzero] != 0) - lowzero++; - - if (loc > high) - high = loc; - - if (! (BASE_MINIMUM <= j && j <= BASE_MAXIMUM)) - abort (); - return j; - } + { + for (k = 0; k < t; k++) + { + loc = j + from[k]; + table[loc] = to[k]; + if (nondeterministic_parser && conflict_to != NULL) + conflict_table[loc] = conflict_to[k]; + check[loc] = from[k]; + } + + while (table[lowzero] != 0) + lowzero++; + + if (loc > high) + high = loc; + + aver (BASE_MINIMUM <= j && j <= BASE_MAXIMUM); + return j; + } } } @@ -745,11 +762,11 @@ pack_table (void) { int i; - CALLOC (base, nvectors); - CALLOC (pos, nentries); - CALLOC (table, table_size); - CALLOC (conflict_table, table_size); - CALLOC (check, table_size); + base = xnmalloc (nvectors, sizeof *base); + pos = xnmalloc (nentries, sizeof *pos); + table = xcalloc (table_size, sizeof *table); + conflict_table = xcalloc (table_size, sizeof *conflict_table); + check = xnmalloc (table_size, sizeof *check); lowzero = 0; high = 0; @@ -766,11 +783,11 @@ pack_table (void) base_number place; if (s < 0) - /* A new set of state actions, or a nonterminal. */ - place = pack_vector (i); + /* A new set of state actions, or a nonterminal. */ + place = pack_vector (i); else - /* Action of I were already coded for S. */ - place = base[s]; + /* Action of I were already coded for S. */ + place = base[s]; pos[i] = place; base[order[i]] = place; @@ -798,17 +815,16 @@ tables_generate (void) /* This is a poor way to make sure the sizes are properly correlated. In particular the signedness is not taken into account. But it's not useless. */ - verify (sizes_are_properly_correlated, - (sizeof nstates <= sizeof nvectors - && sizeof nvars <= sizeof nvectors)); + verify (sizeof nstates <= sizeof nvectors + && sizeof nvars <= sizeof nvectors); nvectors = state_number_as_int (nstates) + nvars; - CALLOC (froms, nvectors); - CALLOC (tos, nvectors); - CALLOC (conflict_tos, nvectors); - CALLOC (tally, nvectors); - CALLOC (width, nvectors); + froms = xcalloc (nvectors, sizeof *froms); + tos = xcalloc (nvectors, sizeof *tos); + conflict_tos = xcalloc (nvectors, sizeof *conflict_tos); + tally = xcalloc (nvectors, sizeof *tally); + width = xnmalloc (nvectors, sizeof *width); token_actions (); @@ -817,7 +833,7 @@ tables_generate (void) free (from_state); free (to_state); - CALLOC (order, nvectors); + order = xcalloc (nvectors, sizeof *order); sort_actions (); pack_table (); free (order); @@ -829,7 +845,7 @@ tables_generate (void) { free (froms[i]); free (tos[i]); - XFREE (conflict_tos[i]); + free (conflict_tos[i]); } free (froms);