X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/2c5f66eda72bb8b158bccf0a528d9dbb2c839f0c..eeeb962b:/src/LR0.c diff --git a/src/LR0.c b/src/LR0.c index ab59335d..06ee51f6 100644 --- a/src/LR0.c +++ b/src/LR0.c @@ -1,5 +1,5 @@ /* Generate the nondeterministic finite state machine for bison, - Copyright 1984, 1986, 1989, 2000 Free Software Foundation, Inc. + Copyright 1984, 1986, 1989, 2000, 2001 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -23,6 +23,8 @@ The entry point is generate_states. */ #include "system.h" +#include "getargs.h" +#include "reader.h" #include "gram.h" #include "state.h" #include "complain.h" @@ -48,7 +50,7 @@ static short *redset = NULL; static short *shiftset = NULL; static short **kernel_base = NULL; -static short **kernel_end = NULL; +static int *kernel_size = NULL; static short *kernel_items = NULL; /* hash table for states, to recognize equivalent ones. */ @@ -60,8 +62,6 @@ static core **state_table = NULL; static void allocate_itemsets (void) { - short *itemp = NULL; - int symbol; int i; int count; short *symbol_count = NULL; @@ -69,17 +69,12 @@ allocate_itemsets (void) count = 0; symbol_count = XCALLOC (short, nsyms); - itemp = ritem; - symbol = *itemp++; - while (symbol) - { - if (symbol > 0) - { - count++; - symbol_count[symbol]++; - } - symbol = *itemp++; - } + for (i = 0; ritem[i]; ++i) + if (ritem[i] > 0) + { + count++; + symbol_count[ritem[i]]++; + } /* See comments before new_itemsets. All the vectors of items live inside KERNEL_ITEMS. The number of active items after @@ -99,7 +94,7 @@ allocate_itemsets (void) } shift_symbol = symbol_count; - kernel_end = XCALLOC (short *, nsyms); + kernel_size = XCALLOC (int, nsyms); } @@ -121,7 +116,7 @@ free_storage (void) XFREE (redset); XFREE (shiftset); XFREE (kernel_base); - XFREE (kernel_end); + XFREE (kernel_size); XFREE (kernel_items); XFREE (state_table); } @@ -137,8 +132,7 @@ free_storage (void) | shift_symbol is set to a vector of the symbols that can be | | shifted. For each symbol in the grammar, kernel_base[symbol] | | points to a vector of item numbers activated if that symbol is | -| shifted, and kernel_end[symbol] points after the end of that | -| vector. | +| shifted, and kernel_size[symbol] is their numbers. | `----------------------------------------------------------------*/ static void @@ -146,38 +140,29 @@ new_itemsets (void) { int i; int shiftcount; - short *isp; - short *ksp; - int symbol; -#if TRACE - fprintf (stderr, "Entering new_itemsets, state = %d\n", - this_state->number); -#endif + if (trace_flag) + fprintf (stderr, "Entering new_itemsets, state = %d\n", + this_state->number); for (i = 0; i < nsyms; i++) - kernel_end[i] = NULL; + kernel_size[i] = 0; shiftcount = 0; - isp = itemset; - - while (isp < itemsetend) + for (i = 0; i < itemsetsize; ++i) { - i = *isp++; - symbol = ritem[i]; + int symbol = ritem[itemset[i]]; if (symbol > 0) { - ksp = kernel_end[symbol]; - - if (!ksp) + if (!kernel_size[symbol]) { - shift_symbol[shiftcount++] = symbol; - ksp = kernel_base[symbol]; + shift_symbol[shiftcount] = symbol; + shiftcount++; } - *ksp++ = i + 1; - kernel_end[symbol] = ksp; + kernel_base[symbol][kernel_size[symbol]] = itemset[i] + 1; + kernel_size[symbol]++; } } @@ -194,29 +179,24 @@ new_itemsets (void) static core * new_state (int symbol) { - int n; core *p; -#if TRACE - fprintf (stderr, "Entering new_state, state = %d, symbol = %d\n", - nstates, symbol); -#endif + if (trace_flag) + fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n", + this_state->number, symbol, tags[symbol]); if (nstates >= MAXSHORT) fatal (_("too many states (max %d)"), MAXSHORT); - n = kernel_end[symbol] - kernel_base[symbol]; - - p = CORE_ALLOC (n); + p = CORE_ALLOC (kernel_size[symbol]); p->accessing_symbol = symbol; p->number = nstates; - p->nitems = n; + p->nitems = kernel_size[symbol]; - shortcpy (p->items, kernel_base[symbol], n); + shortcpy (p->items, kernel_base[symbol], kernel_size[symbol]); last_state->next = p; last_state = p; - nstates++; return p; @@ -226,55 +206,39 @@ new_state (int symbol) /*--------------------------------------------------------------. | Find the state number for the state we would get to (from the | | current state) by shifting symbol. Create a new state if no | -| equivalent one exists already. Used by append_states. | +| equivalent one exists already. Used by append_states. | `--------------------------------------------------------------*/ static int get_state (int symbol) { int key; - short *isp1; - short *isp2; - short *iend; + int i; core *sp; - int found; - - int n; - -#if TRACE - fprintf (stderr, "Entering get_state, state = %d, symbol = %d\n", - nstates, symbol); -#endif - isp1 = kernel_base[symbol]; - iend = kernel_end[symbol]; - n = iend - isp1; + if (trace_flag) + fprintf (stderr, "Entering get_state, state = %d, symbol = %d (%s)\n", + this_state->number, symbol, tags[symbol]); - /* add up the target state's active item numbers to get a hash key */ + /* Add up the target state's active item numbers to get a hash key. + */ key = 0; - while (isp1 < iend) - key += *isp1++; - + for (i = 0; i < kernel_size[symbol]; ++i) + key += kernel_base[symbol][i]; key = key % STATE_TABLE_SIZE; - sp = state_table[key]; if (sp) { - found = 0; + int found = 0; while (!found) { - if (sp->nitems == n) + if (sp->nitems == kernel_size[symbol]) { found = 1; - isp1 = kernel_base[symbol]; - isp2 = sp->items; - - while (found && isp1 < iend) - { - if (*isp1++ != *isp2++) - found = 0; - } + for (i = 0; i < kernel_size[symbol]; ++i) + if (kernel_base[symbol][i] != sp->items[i]) + found = 0; } if (!found) @@ -296,6 +260,9 @@ get_state (int symbol) state_table[key] = sp = new_state (symbol); } + if (trace_flag) + fprintf (stderr, "Exiting get_state => %d\n", sp->number); + return sp->number; } @@ -313,9 +280,9 @@ append_states (void) int j; int symbol; -#if TRACE - fprintf (stderr, "Entering append_states\n"); -#endif + if (trace_flag) + fprintf (stderr, "Entering append_states, state = %d\n", + this_state->number); /* first sort shift_symbol into increasing order */ @@ -332,20 +299,14 @@ append_states (void) } for (i = 0; i < nshifts; i++) - { - symbol = shift_symbol[i]; - shiftset[i] = get_state (symbol); - } + shiftset[i] = get_state (shift_symbol[i]); } static void new_states (void) { - core *p; - - p = CORE_ALLOC (0); - first_state = last_state = this_state = p; + first_state = last_state = this_state = CORE_ALLOC (0); nstates = 1; } @@ -353,9 +314,7 @@ new_states (void) static void save_shifts (void) { - shifts *p; - - p = SHIFTS_ALLOC (nshifts); + shifts *p = SHIFTS_ALLOC (nshifts); p->number = this_state->number; p->nshifts = nshifts; @@ -363,15 +322,10 @@ save_shifts (void) shortcpy (p->shifts, shiftset, nshifts); if (last_shift) - { - last_shift->next = p; - last_shift = p; - } + last_shift->next = p; else - { - first_shift = p; - last_shift = p; - } + first_shift = p; + last_shift = p; } @@ -588,19 +542,15 @@ augment_automaton (void) static void save_reductions (void) { - short *isp; - int item; int count; - reductions *p; - - short *rend; + int i; /* Find and count the active items that represent ends of rules. */ count = 0; - for (isp = itemset; isp < itemsetend; isp++) + for (i = 0; i < itemsetsize; ++i) { - item = ritem[*isp]; + int item = ritem[itemset[i]]; if (item < 0) redset[count++] = -item; } @@ -609,7 +559,7 @@ save_reductions (void) if (count) { - p = REDUCTIONS_ALLOC (count); + reductions *p = REDUCTIONS_ALLOC (count); p->number = this_state->number; p->nreds = count; @@ -617,15 +567,10 @@ save_reductions (void) shortcpy (p->rules, redset, count); if (last_reduction) - { - last_reduction->next = p; - last_reduction = p; - } + last_reduction->next = p; else - { - first_reduction = p; - last_reduction = p; - } + first_reduction = p; + last_reduction = p; } }