X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/f693ad146e6e4951662d60903b8512d518cb09da..5ee2aaf2fa7f3148d4ae3de6efecdbcd22ac6fc6:/src/lalr.c diff --git a/src/lalr.c b/src/lalr.c index 0b269255..150b15e9 100644 --- a/src/lalr.c +++ b/src/lalr.c @@ -132,80 +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); - - { - state_t *sp; - for (sp = first_state; sp; sp = sp->next) - state_table[sp->number] = sp; - } - - { - shifts *sp; - for (sp = first_shift; sp; sp = sp->next) - state_table[sp->number]->shifts = sp; - } - - { - reductions *rp; - for (rp = first_reduction; rp; rp = rp->next) - state_table[rp->number]->reductions = rp; - } - - /* Pessimization, but simplification of the code: make sure all the - states have a shifts, even if reduced to 0 shifts. */ - { - int i; - for (i = 0; i < nstates; i++) - if (!state_table[i]->shifts) - state_table[i]->shifts = shifts_new (0); - } - - /* 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]->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; - } -} - - static void initialize_LA (void) { @@ -234,29 +160,31 @@ 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 (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) - { - symbol = state_table[sp->shifts[i]]->accessing_symbol; + 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; - if (ngotos == MAXSHORT) - fatal (_("too many gotos (max %d)"), MAXSHORT); + if (ngotos == MAXSHORT) + fatal (_("too many gotos (max %d)"), MAXSHORT); - ngotos++; - goto_map[symbol]++; - } + ngotos++; + goto_map[symbol]++; + } + } k = 0; for (i = ntokens; i < nsyms; i++) @@ -274,17 +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; + } } } @@ -603,12 +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 ();