X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/aa2aab3c165a39d7ec65696223479c343731a98e..dbfb6dcd339f9aa3bf2a7ed43521319aaf66f7a5:/src/lalr.c diff --git a/src/lalr.c b/src/lalr.c index e6738bda..150b15e9 100644 --- a/src/lalr.c +++ b/src/lalr.c @@ -36,7 +36,7 @@ /* All the decorated states, indexed by the state number. Warning: there is a state_TABLE in LR0.c, but it is different and static. */ -state_t *state_table = NULL; +state_t **state_table = NULL; int tokensetsize; short *LAruleno; @@ -132,72 +132,6 @@ digraph (short **relation) } -/*--------------------. -| Build STATE_TABLE. | -`--------------------*/ - -static void -set_state_table (void) -{ - /* NSTATES + 1 because lookahead for the pseudo state number NSTATES - might be used (see conflicts.c). It is too opaque for me to - provide a probably less hacky implementation. --akim */ - state_table = XCALLOC (state_t, nstates + 1); - - { - core *sp; - for (sp = first_state; sp; sp = sp->next) - { - state_table[sp->number].state = sp; - state_table[sp->number].accessing_symbol = sp->accessing_symbol; - } - } - - { - shifts *sp; - for (sp = first_shift; sp; sp = sp->next) - state_table[sp->number].shift_table = sp; - } - - { - reductions *rp; - for (rp = first_reduction; rp; rp = rp->next) - state_table[rp->number].reduction_table = rp; - } - - /* Initializing the lookaheads members. Please note that it must be - performed after having set some of the other members which are - used below. Change with extreme caution. */ - { - int i; - int count = 0; - for (i = 0; i < nstates; i++) - { - int k; - reductions *rp = state_table[i].reduction_table; - shifts *sp = state_table[i].shift_table; - - state_table[i].lookaheads = count; - - if (rp - && (rp->nreds > 1 || (sp && SHIFT_IS_SHIFT (sp, 0)))) - count += rp->nreds; - else - state_table[i].consistent = 1; - - if (sp) - for (k = 0; k < sp->nshifts; k++) - if (SHIFT_IS_ERROR (sp, k)) - { - state_table[i].consistent = 0; - break; - } - } - state_table[nstates].lookaheads = count; - } -} - - static void initialize_LA (void) { @@ -206,7 +140,7 @@ initialize_LA (void) short *np; reductions *rp; - size_t nLA = state_table[nstates].lookaheads; + size_t nLA = state_table[nstates]->lookaheads; if (!nLA) nLA = 1; @@ -216,8 +150,8 @@ initialize_LA (void) np = LAruleno; for (i = 0; i < nstates; i++) - if (!state_table[i].consistent) - if ((rp = state_table[i].reduction_table)) + if (!state_table[i]->consistent) + if ((rp = state_table[i]->reductions)) for (j = 0; j < rp->nreds; j++) *np++ = rp->rules[j]; } @@ -226,23 +160,23 @@ initialize_LA (void) static void set_goto_map (void) { - shifts *sp; + int state; int i; int symbol; int k; short *temp_map; int state2; - int state1; goto_map = XCALLOC (short, nvars + 1) - ntokens; temp_map = XCALLOC (short, nvars + 1) - ntokens; ngotos = 0; - for (sp = first_shift; sp; sp = sp->next) + for (state = 0; state < nstates; ++state) { + shifts *sp = state_table[state]->shifts; for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) { - symbol = state_table[sp->shifts[i]].accessing_symbol; + symbol = state_table[sp->shifts[i]]->accessing_symbol; if (ngotos == MAXSHORT) fatal (_("too many gotos (max %d)"), MAXSHORT); @@ -268,17 +202,20 @@ set_goto_map (void) from_state = XCALLOC (short, ngotos); to_state = XCALLOC (short, ngotos); - for (sp = first_shift; sp; sp = sp->next) + for (state = 0; state < nstates; ++state) { - state1 = sp->number; + shifts *sp = state_table[state]->shifts; for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) { - state2 = sp->shifts[i]; - symbol = state_table[state2].accessing_symbol; + for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) + { + state2 = sp->shifts[i]; + symbol = state_table[state2]->accessing_symbol; - k = temp_map[symbol]++; - from_state[k] = state1; - to_state[k] = state2; + k = temp_map[symbol]++; + from_state[k] = state; + to_state[k] = state2; + } } } @@ -334,31 +271,28 @@ initialize_F (void) for (i = 0; i < ngotos; i++) { int stateno = to_state[i]; - shifts *sp = state_table[stateno].shift_table; + shifts *sp = state_table[stateno]->shifts; - if (sp) + int j; + for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++) { - int j; - for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++) - { - int symbol = state_table[sp->shifts[j]].accessing_symbol; - SETBIT (F + i * tokensetsize, symbol); - } + int symbol = state_table[sp->shifts[j]]->accessing_symbol; + SETBIT (F (i), symbol); + } - for (; j < sp->nshifts; j++) - { - int symbol = state_table[sp->shifts[j]].accessing_symbol; - if (nullable[symbol]) - edge[nedges++] = map_goto (stateno, symbol); - } + for (; j < sp->nshifts; j++) + { + int symbol = state_table[sp->shifts[j]]->accessing_symbol; + if (nullable[symbol]) + edge[nedges++] = map_goto (stateno, symbol); + } - if (nedges) - { - reads[i] = XCALLOC (short, nedges + 1); - shortcpy (reads[i], edge, nedges); - reads[i][nedges] = -1; - nedges = 0; - } + if (nedges) + { + reads[i] = XCALLOC (short, nedges + 1); + shortcpy (reads[i], edge, nedges); + reads[i][nedges] = -1; + nedges = 0; } } @@ -380,8 +314,8 @@ add_lookback_edge (int stateno, int ruleno, int gotono) int found; shorts *sp; - i = state_table[stateno].lookaheads; - k = state_table[stateno + 1].lookaheads; + i = state_table[stateno]->lookaheads; + k = state_table[stateno + 1]->lookaheads; found = 0; while (!found && i < k) { @@ -499,7 +433,7 @@ build_relations (void) { int nedges = 0; int state1 = from_state[i]; - int symbol1 = state_table[to_state[i]].accessing_symbol; + int symbol1 = state_table[to_state[i]]->accessing_symbol; short *rulep; for (rulep = derives[symbol1]; *rulep > 0; rulep++) @@ -512,19 +446,19 @@ build_relations (void) for (rp = ritem + rule_table[*rulep].rhs; *rp > 0; rp++) { - shifts *sp = state_table[stateno].shift_table; + shifts *sp = state_table[stateno]->shifts; int j; for (j = 0; j < sp->nshifts; j++) { stateno = sp->shifts[j]; - if (state_table[stateno].accessing_symbol == *rp) + if (state_table[stateno]->accessing_symbol == *rp) break; } states[length++] = stateno; } - if (!state_table[stateno].consistent) + if (!state_table[stateno]->consistent) add_lookback_edge (stateno, *rulep, i); length--; @@ -582,7 +516,7 @@ compute_lookaheads (void) int i; shorts *sp; - for (i = 0; i < state_table[nstates].lookaheads; i++) + for (i = 0; i < state_table[nstates]->lookaheads; i++) for (sp = lookback[i]; sp; sp = sp->next) { int size = LA (i + 1) - LA (i); @@ -592,7 +526,7 @@ compute_lookaheads (void) } /* Free LOOKBACK. */ - for (i = 0; i < state_table[nstates].lookaheads; i++) + for (i = 0; i < state_table[nstates]->lookaheads; i++) LIST_FREE (shorts, lookback[i]); XFREE (lookback); @@ -600,12 +534,48 @@ compute_lookaheads (void) } +/*--------------------------------------. +| Initializing the lookaheads members. | +`--------------------------------------*/ + +static void +initialize_lookaheads (void) +{ + int i; + int count = 0; + for (i = 0; i < nstates; i++) + { + int k; + reductions *rp = state_table[i]->reductions; + shifts *sp = state_table[i]->shifts; + + state_table[i]->lookaheads = count; + + if (rp + && (rp->nreds > 1 || (sp->nshifts && SHIFT_IS_SHIFT (sp, 0)))) + count += rp->nreds; + else + state_table[i]->consistent = 1; + + for (k = 0; k < sp->nshifts; k++) + if (SHIFT_IS_ERROR (sp, k)) + { + state_table[i]->consistent = 0; + break; + } + } + + /* Seems to be needed by conflicts.c. */ + state_table[nstates] = STATE_ALLOC (0); + state_table[nstates]->lookaheads = count; +} + void lalr (void) { tokensetsize = WORDSIZE (ntokens); - set_state_table (); + initialize_lookaheads (); initialize_LA (); set_goto_map (); initialize_F ();