X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/1a2b5d37e1d44b47cd51220945f4ba29c228a419..05811fd7558459179d1474ee86b72a60d67c3615:/src/lalr.c diff --git a/src/lalr.c b/src/lalr.c index 55986f33..251878a0 100644 --- a/src/lalr.c +++ b/src/lalr.c @@ -1,5 +1,6 @@ /* Compute look-ahead criteria for bison, - Copyright 1984, 1986, 1989, 2000, 2001 Free Software Foundation, Inc. + Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002 + Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -24,142 +25,67 @@ tokens they accept. */ #include "system.h" +#include "bitset.h" +#include "bitsetv.h" +#include "relation.h" +#include "quotearg.h" +#include "symtab.h" +#include "gram.h" #include "reader.h" #include "types.h" #include "LR0.h" -#include "symtab.h" -#include "gram.h" #include "complain.h" #include "lalr.h" #include "nullable.h" #include "derives.h" #include "getargs.h" -/* All the decorated states, indexed by the state number. */ -state_t **state_table = NULL; - -int tokensetsize; -short *LAruleno; -unsigned *LA; +rule_t **LArule = NULL; +bitsetv LA = NULL; size_t nLA; static int ngotos; -short *goto_map; -short *from_state; -short *to_state; +short *goto_map = NULL; +state_number_t *from_state = NULL; +state_number_t *to_state = NULL; /* And for the famous F variable, which name is so descriptive that a comment is hardly needed. . */ -static unsigned *F = NULL; -#define F(Rule) (F + (Rule) * tokensetsize) +static bitsetv F = NULL; static short **includes; static shorts **lookback; -/*---------------------------------------------------------------. -| digraph & traverse. | -| | -| The following variables are used as common storage between the | -| two. | -`---------------------------------------------------------------*/ - -static short **R; -static short *INDEX; -static short *VERTICES; -static int top; -static int infinity; - -static void -traverse (int i) -{ - int j; - size_t k; - int height; - size_t size = F (i + 1) - F(i); - - VERTICES[++top] = i; - INDEX[i] = height = top; - - if (R[i]) - for (j = 0; R[i][j] >= 0; ++j) - { - if (INDEX[R[i][j]] == 0) - traverse (R[i][j]); - - if (INDEX[i] > INDEX[R[i][j]]) - INDEX[i] = INDEX[R[i][j]]; - - for (k = 0; k < size; ++k) - F (i)[k] |= F (R[i][j])[k]; - } - - if (INDEX[i] == height) - for (;;) - { - j = VERTICES[top--]; - INDEX[j] = infinity; - - if (i == j) - break; - - for (k = 0; k < size; ++k) - F (j)[k] = F (i)[k]; - } -} - - -static void -digraph (short **relation) -{ - int i; - - infinity = ngotos + 2; - INDEX = XCALLOC (short, ngotos + 1); - VERTICES = XCALLOC (short, ngotos + 1); - top = 0; - - R = relation; - - for (i = 0; i < ngotos; i++) - INDEX[i] = 0; - - for (i = 0; i < ngotos; i++) - if (INDEX[i] == 0 && R[i]) - traverse (i); - - XFREE (INDEX); - XFREE (VERTICES); -} static void initialize_LA (void) { - int i; + state_number_t i; int j; - short *np; + rule_t **np; /* Avoid having to special case 0. */ if (!nLA) nLA = 1; - LA = XCALLOC (unsigned, nLA * tokensetsize); - LAruleno = XCALLOC (short, nLA); + LA = bitsetv_create (nLA, ntokens, BITSET_FIXED); + LArule = XCALLOC (rule_t *, nLA); lookback = XCALLOC (shorts *, nLA); - np = LAruleno; + np = LArule; for (i = 0; i < nstates; i++) - if (!state_table[i]->consistent) - for (j = 0; j < state_table[i]->reductions->nreds; j++) - *np++ = state_table[i]->reductions->rules[j]; + if (!states[i]->consistent) + for (j = 0; j < states[i]->reductions->nreds; j++) + *np++ = &rules[states[i]->reductions->rules[j]]; } static void set_goto_map (void) { - int state, i; + state_number_t state; short *temp_map; goto_map = XCALLOC (short, nvars + 1) - ntokens; @@ -168,11 +94,12 @@ set_goto_map (void) ngotos = 0; for (state = 0; state < nstates; ++state) { - shifts *sp = state_table[state]->shifts; + shifts_t *sp = states[state]->shifts; + int i; for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) { - if (ngotos == MAXSHORT) - fatal (_("too many gotos (max %d)"), MAXSHORT); + if (ngotos == SHRT_MAX) + fatal (_("too many gotos (max %d)"), SHRT_MAX); ngotos++; goto_map[SHIFT_SYMBOL (sp, i)]++; @@ -181,6 +108,7 @@ set_goto_map (void) { int k = 0; + int i; for (i = ntokens; i < nsyms; i++) { temp_map[i] = k; @@ -194,12 +122,13 @@ set_goto_map (void) temp_map[nsyms] = ngotos; } - from_state = XCALLOC (short, ngotos); - to_state = XCALLOC (short, ngotos); + from_state = XCALLOC (state_number_t, ngotos); + to_state = XCALLOC (state_number_t, ngotos); for (state = 0; state < nstates; ++state) { - shifts *sp = state_table[state]->shifts; + shifts_t *sp = states[state]->shifts; + int i; for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i) { int k = temp_map[SHIFT_SYMBOL (sp, i)]++; @@ -218,12 +147,12 @@ set_goto_map (void) `----------------------------------------------------------*/ static int -map_goto (int state, int symbol) +map_goto (state_number_t state, symbol_number_t symbol) { int high; int low; int middle; - int s; + state_number_t s; low = goto_map[symbol]; high = goto_map[symbol + 1] - 1; @@ -255,20 +184,20 @@ initialize_F (void) int i; - F = XCALLOC (unsigned, ngotos * tokensetsize); + F = bitsetv_create (ngotos, ntokens, BITSET_FIXED); for (i = 0; i < ngotos; i++) { - int stateno = to_state[i]; - shifts *sp = state_table[stateno]->shifts; + state_number_t stateno = to_state[i]; + shifts_t *sp = states[stateno]->shifts; int j; for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++) - SETBIT (F (i), SHIFT_SYMBOL (sp, j)); + bitset_set (F[i], SHIFT_SYMBOL (sp, j)); for (; j < sp->nshifts; j++) { - int symbol = SHIFT_SYMBOL (sp, j); + symbol_number_t symbol = SHIFT_SYMBOL (sp, j); if (nullable[symbol]) edge[nedges++] = map_goto (stateno, symbol); } @@ -276,13 +205,13 @@ initialize_F (void) if (nedges) { reads[i] = XCALLOC (short, nedges + 1); - shortcpy (reads[i], edge, nedges); + memcpy (reads[i], edge, nedges * sizeof (edge[0])); reads[i][nedges] = -1; nedges = 0; } } - digraph (reads); + relation_digraph (reads, ngotos, &F); for (i = 0; i < ngotos; i++) XFREE (reads[i]); @@ -293,115 +222,30 @@ initialize_F (void) static void -add_lookback_edge (state_t *state, int ruleno, int gotono) +add_lookback_edge (state_t *state, rule_number_t ruleno, int gotono) { int i; shorts *sp; for (i = 0; i < state->nlookaheads; ++i) - if (LAruleno[state->lookaheadsp + i] == ruleno) + if (state->lookaheads_rule[i]->number == ruleno) break; - assert (LAruleno[state->lookaheadsp + i] == ruleno); + assert (state->lookaheads_rule[i]->number == ruleno); sp = XCALLOC (shorts, 1); - sp->next = lookback[state->lookaheadsp + i]; + sp->next = lookback[(state->lookaheads - LA) + i]; sp->value = gotono; - lookback[state->lookaheadsp + i] = sp; -} - - -static void -matrix_print (FILE *out, short **matrix, int n) -{ - int i, j; - - for (i = 0; i < n; ++i) - { - fprintf (out, "%3d: ", i); - if (matrix[i]) - for (j = 0; matrix[i][j] != -1; ++j) - fprintf (out, "%3d ", matrix[i][j]); - fputc ('\n', out); - } - fputc ('\n', out); + lookback[(state->lookaheads - LA) + i] = sp; } -/*-------------------------------------------------------------------. -| Return the transpose of R_ARG, of size N. Destroy R_ARG, as it is | -| replaced with the result. | -| | -| R_ARG[I] is NULL or a -1 terminated list of numbers. | -| | -| RESULT[NUM] is NULL or the -1 terminated list of the I such as NUM | -| is in R_ARG[I]. | -`-------------------------------------------------------------------*/ - -static short ** -transpose (short **R_arg, int n) -{ - /* The result. */ - short **new_R = XCALLOC (short *, n); - /* END_R[I] -- next entry of NEW_R[I]. */ - short **end_R = XCALLOC (short *, n); - /* NEDGES[I] -- total size of NEW_R[I]. */ - short *nedges = XCALLOC (short, n); - int i, j; - - if (trace_flag) - { - fputs ("transpose: input\n", stderr); - matrix_print (stderr, R_arg, n); - } - - /* Count. */ - for (i = 0; i < n; i++) - if (R_arg[i]) - for (j = 0; R_arg[i][j] >= 0; ++j) - ++nedges[R_arg[i][j]]; - - /* Allocate. */ - for (i = 0; i < n; i++) - if (nedges[i] > 0) - { - short *sp = XCALLOC (short, nedges[i] + 1); - sp[nedges[i]] = -1; - new_R[i] = sp; - end_R[i] = sp; - } - - /* Store. */ - for (i = 0; i < n; i++) - if (R_arg[i]) - for (j = 0; R_arg[i][j] >= 0; ++j) - { - *end_R[R_arg[i][j]] = i; - ++end_R[R_arg[i][j]]; - } - - free (nedges); - free (end_R); - - /* Free the input: it is replaced with the result. */ - for (i = 0; i < n; i++) - XFREE (R_arg[i]); - free (R_arg); - - if (trace_flag) - { - fputs ("transpose: output\n", stderr); - matrix_print (stderr, new_R, n); - } - - return new_R; -} static void build_relations (void) { short *edge = XCALLOC (short, ngotos + 1); - short *states = XCALLOC (short, ritem_longest_rhs () + 1); + state_number_t *states1 = XCALLOC (state_number_t, ritem_longest_rhs () + 1); int i; includes = XCALLOC (short *, ngotos); @@ -409,29 +253,22 @@ build_relations (void) for (i = 0; i < ngotos; i++) { int nedges = 0; - int symbol1 = state_table[to_state[i]]->accessing_symbol; - short *rulep; + symbol_number_t symbol1 = states[to_state[i]]->accessing_symbol; + rule_number_t *rulep; for (rulep = derives[symbol1]; *rulep > 0; rulep++) { int done; int length = 1; - short *rp; - state_t *state = state_table[from_state[i]]; - states[0] = state->number; + item_number_t *rp; + state_t *state = states[from_state[i]]; + states1[0] = state->number; - for (rp = &ritem[rules[*rulep].rhs]; *rp >= 0; rp++) + for (rp = rules[*rulep].rhs; *rp >= 0; rp++) { - shifts *sp = state->shifts; - int j; - for (j = 0; j < sp->nshifts; j++) - { - state = state_table[sp->shifts[j]]; - if (state->accessing_symbol == *rp) - break; - } - - states[length++] = state->number; + state = shifts_to (state->shifts, + item_number_as_symbol_number (*rp)); + states1[length++] = state->number; } if (!state->consistent) @@ -446,7 +283,9 @@ build_relations (void) /* JF added rp>=ritem && I hope to god its right! */ if (rp >= ritem && ISVAR (*rp)) { - edge[nedges++] = map_goto (states[--length], *rp); + /* Downcasting from item_number_t to symbol_number_t. */ + edge[nedges++] = map_goto (states1[--length], + item_number_as_symbol_number (*rp)); if (nullable[*rp]) done = 0; } @@ -464,9 +303,9 @@ build_relations (void) } XFREE (edge); - XFREE (states); + XFREE (states1); - includes = transpose (includes, ngotos); + relation_transpose (&includes, ngotos); } @@ -476,7 +315,7 @@ compute_FOLLOWS (void) { int i; - digraph (includes); + relation_digraph (includes, ngotos, &F); for (i = 0; i < ngotos; i++) XFREE (includes[i]); @@ -493,37 +332,35 @@ compute_lookaheads (void) for (i = 0; i < nLA; i++) for (sp = lookback[i]; sp; sp = sp->next) - { - int size = LA (i + 1) - LA (i); - int j; - for (j = 0; j < size; ++j) - LA (i)[j] |= F (sp->value)[j]; - } + bitset_or (LA[i], LA[i], F[sp->value]); /* Free LOOKBACK. */ for (i = 0; i < nLA; i++) LIST_FREE (shorts, lookback[i]); XFREE (lookback); - XFREE (F); + bitsetv_free (F); } -/*--------------------------------------. -| Initializing the lookaheads members. | -`--------------------------------------*/ +/*-------------------------------------------------------------. +| Count the number of lookaheads required for each state | +| (NLOOKAHEADS member). Compute the total number of LA, NLA. | +`-------------------------------------------------------------*/ static void -initialize_lookaheads (void) +states_lookaheads_count (void) { - int i; + state_number_t i; nLA = 0; + + /* Count */ for (i = 0; i < nstates; i++) { int k; int nlookaheads = 0; - reductions *rp = state_table[i]->reductions; - shifts *sp = state_table[i]->shifts; + reductions_t *rp = states[i]->reductions; + shifts_t *sp = states[i]->shifts; /* We need a lookahead either to distinguish different reductions (i.e., there are two or more), or to distinguish a @@ -533,22 +370,44 @@ initialize_lookaheads (void) || (rp->nreds == 1 && sp->nshifts && SHIFT_IS_SHIFT (sp, 0))) nlookaheads += rp->nreds; else - state_table[i]->consistent = 1; + states[i]->consistent = 1; for (k = 0; k < sp->nshifts; k++) if (SHIFT_IS_ERROR (sp, k)) { - state_table[i]->consistent = 0; + states[i]->consistent = 0; break; } - state_table[i]->nlookaheads = nlookaheads; - state_table[i]->lookaheadsp = nLA; + states[i]->nlookaheads = nlookaheads; nLA += nlookaheads; } } +/*--------------------------------------. +| Initializing the lookaheads members. | +`--------------------------------------*/ + +static void +states_lookaheads_initialize (void) +{ + state_number_t i; + bitsetv pLA = LA; + rule_t **pLArule = LArule; + + /* Initialize the members LOOKAHEADS and LOOKAHEADS_RULE for each + state. */ + for (i = 0; i < nstates; i++) + { + states[i]->lookaheads = pLA; + states[i]->lookaheads_rule = pLArule; + pLA += states[i]->nlookaheads; + pLArule += states[i]->nlookaheads; + } +} + + /*---------------------------------------. | Output the lookaheads for each state. | `---------------------------------------*/ @@ -556,19 +415,20 @@ initialize_lookaheads (void) static void lookaheads_print (FILE *out) { - int i, j, k; + state_number_t i; + int j, k; fprintf (out, "Lookaheads: BEGIN\n"); for (i = 0; i < nstates; ++i) { fprintf (out, "State %d: %d lookaheads\n", - i, state_table[i]->nlookaheads); + i, states[i]->nlookaheads); - for (j = 0; j < state_table[i]->nlookaheads; ++j) + for (j = 0; j < states[i]->nlookaheads; ++j) for (k = 0; k < ntokens; ++k) - if (BITISSET (LA (state_table[i]->lookaheadsp + j), j)) + if (bitset_test (states[i]->lookaheads[j], k)) fprintf (out, " on %d (%s) -> rule %d\n", - k, symbols[k]->tag, - -LAruleno[state_table[i]->lookaheadsp + j] - 1); + k, symbol_tag_get (symbols[k]), + states[i]->lookaheads_rule[j]->number - 1); } fprintf (out, "Lookaheads: END\n"); } @@ -576,10 +436,9 @@ lookaheads_print (FILE *out) void lalr (void) { - tokensetsize = WORDSIZE (ntokens); - - initialize_lookaheads (); + states_lookaheads_count (); initialize_LA (); + states_lookaheads_initialize (); set_goto_map (); initialize_F (); build_relations ();