/* Compute look-ahead criteria for bison,
- Copyright (C) 1984, 1986, 1989 Free Software Foundation, Inc.
+ Copyright 1984, 1986, 1989, 2000, 2001 Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ 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.
+ 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.
-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.
+ 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.
-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. */
+ 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. */
-/* Compute how to make the finite state machine deterministic;
- find which rules need lookahead in each state, and which lookahead tokens they accept.
+/* Compute how to make the finite state machine deterministic; find
+ which rules need lookahead in each state, and which lookahead
+ tokens they accept. */
-lalr(), the entry point, builds these data structures:
-
-goto_map, from_state and to_state
- record each shift transition which accepts a variable (a nonterminal).
-ngotos is the number of such transitions.
-from_state[t] is the state number which a transition leads from
-and to_state[t] is the state number it leads to.
-All the transitions that accept a particular variable are grouped together and
-goto_map[i - ntokens] is the index in from_state and to_state of the first of them.
-
-consistent[s] is nonzero if no lookahead is needed to decide what to do in state s.
-
-LAruleno is a vector which records the rules that need lookahead in various states.
-The elements of LAruleno that apply to state s are those from
- lookaheads[s] through lookaheads[s+1]-1.
-Each element of LAruleno is a rule number.
-
-If lr is the length of LAruleno, then a number from 0 to lr-1
-can specify both a rule and a state where the rule might be applied.
-
-LA is a lr by ntokens matrix of bits.
-LA[l, i] is 1 if the rule LAruleno[l] is applicable in the appropriate state
- when the next token is symbol i.
-If LA[l, i] and LA[l, j] are both 1 for i != j, it is a conflict.
-*/
-
-#include <stdio.h>
#include "system.h"
-#include "machine.h"
#include "types.h"
-#include "state.h"
-#include "alloc.h"
+#include "LR0.h"
#include "gram.h"
#include "complain.h"
+#include "lalr.h"
+#include "nullable.h"
+#include "derives.h"
-extern short **derives;
-extern char *nullable;
-
+/* 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;
int tokensetsize;
-short *lookaheads;
short *LAruleno;
unsigned *LA;
-short *accessing_symbol;
-char *consistent;
-core **state_table;
-shifts **shift_table;
-reductions **reduction_table;
+
short *goto_map;
short *from_state;
short *to_state;
-void lalr PARAMS((void));
-short **transpose PARAMS((short **, int));
-void set_state_table PARAMS((void));
-void set_accessing_symbol PARAMS((void));
-void set_shift_table PARAMS((void));
-void set_reduction_table PARAMS((void));
-void set_maxrhs PARAMS((void));
-void initialize_LA PARAMS((void));
-void set_goto_map PARAMS((void));
-int map_goto PARAMS((int, int));
-void initialize_F PARAMS((void));
-void build_relations PARAMS((void));
-void add_lookback_edge PARAMS((int, int, int));
-void compute_FOLLOWS PARAMS((void));
-void compute_lookaheads PARAMS((void));
-void digraph PARAMS((short **));
-void traverse PARAMS((register int));
-
-extern void berror PARAMS((char *));
+extern void berror PARAMS ((const char *));
static int infinity;
-static int maxrhs;
static int ngotos;
-static unsigned *F;
+
+/* And for the famous F variable, which named is so descriptive that a
+ comment is hardly needed. <grin>. */
+static unsigned *F = NULL;
+#define F(Rule) (F + (Rule) * tokensetsize)
+
static short **includes;
static shorts **lookback;
static short **R;
static int top;
-void
-lalr (void)
+static void
+traverse (int i)
{
- tokensetsize = WORDSIZE(ntokens);
-
- set_state_table();
- set_accessing_symbol();
- set_shift_table();
- set_reduction_table();
- set_maxrhs();
- initialize_LA();
- set_goto_map();
- initialize_F();
- build_relations();
- compute_FOLLOWS();
- compute_lookaheads();
-}
+ unsigned *fp1;
+ unsigned *fp2;
+ unsigned *fp3;
+ int j;
+ short *rp;
+ int height;
+ unsigned *base;
-void
-set_state_table (void)
-{
- register core *sp;
+ VERTICES[++top] = i;
+ INDEX[i] = height = top;
- state_table = NEW2(nstates, core *);
+ base = F (i);
+ fp3 = F (i + 1);
- for (sp = first_state; sp; sp = sp->next)
- state_table[sp->number] = sp;
-}
+ rp = R[i];
+ if (rp)
+ {
+ while ((j = *rp++) >= 0)
+ {
+ if (INDEX[j] == 0)
+ traverse (j);
+ if (INDEX[i] > INDEX[j])
+ INDEX[i] = INDEX[j];
-void
-set_accessing_symbol (void)
-{
- register core *sp;
+ fp1 = base;
+ fp2 = F (j);
+
+ while (fp1 < fp3)
+ *fp1++ |= *fp2++;
+ }
+ }
+
+ if (INDEX[i] == height)
+ {
+ for (;;)
+ {
+ j = VERTICES[top--];
+ INDEX[j] = infinity;
- accessing_symbol = NEW2(nstates, short);
+ if (i == j)
+ break;
- for (sp = first_state; sp; sp = sp->next)
- accessing_symbol[sp->number] = sp->accessing_symbol;
+ fp1 = base;
+ fp2 = F (j);
+
+ while (fp1 < fp3)
+ *fp2++ = *fp1++;
+ }
+ }
}
-void
-set_shift_table (void)
+static void
+digraph (short **relation)
{
- register shifts *sp;
+ int i;
- shift_table = NEW2(nstates, shifts *);
+ infinity = ngotos + 2;
+ INDEX = XCALLOC (short, ngotos + 1);
+ VERTICES = XCALLOC (short, ngotos + 1);
+ top = 0;
- for (sp = first_shift; sp; sp = sp->next)
- shift_table[sp->number] = sp;
-}
+ R = relation;
+ for (i = 0; i < ngotos; i++)
+ INDEX[i] = 0;
-void
-set_reduction_table (void)
-{
- register reductions *rp;
+ for (i = 0; i < ngotos; i++)
+ if (INDEX[i] == 0 && R[i])
+ traverse (i);
+
+ XFREE (INDEX);
+ XFREE (VERTICES);
+}
- reduction_table = NEW2(nstates, reductions *);
- for (rp = first_reduction; rp; rp = rp->next)
- reduction_table[rp->number] = rp;
+/*--------------------.
+| 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 && !ISVAR (state_table[sp->shifts[0]].accessing_symbol))))
+ count += rp->nreds;
+ else
+ state_table[i].consistent = 1;
+
+ if (sp)
+ for (k = 0; k < sp->nshifts; k++)
+ if (state_table[sp->shifts[k]].accessing_symbol
+ == error_token_number)
+ {
+ state_table[i].consistent = 0;
+ break;
+ }
+ }
+ state_table[nstates].lookaheads = count;
+ }
}
-void
-set_maxrhs (void)
+/* Return the size of the longest ride hand side of the rules. */
+static size_t
+maxrhs (void)
{
- register short *itemp;
- register int length;
- register int max;
+ short *itemp;
+ int length;
+ int max;
length = 0;
max = 0;
}
else
{
- if (length > max) max = length;
+ if (length > max)
+ max = length;
length = 0;
}
}
- maxrhs = max;
+ return max;
}
-void
+static void
initialize_LA (void)
{
- register int i;
- register int j;
- register int count;
- register reductions *rp;
- register shifts *sp;
- register short *np;
-
- consistent = NEW2(nstates, char);
- lookaheads = NEW2(nstates + 1, short);
-
- count = 0;
- for (i = 0; i < nstates; i++)
- {
- register int k;
-
- lookaheads[i] = count;
+ int i;
+ int j;
+ short *np;
+ reductions *rp;
- rp = reduction_table[i];
- sp = shift_table[i];
- if (rp && (rp->nreds > 1
- || (sp && ! ISVAR(accessing_symbol[sp->shifts[0]]))))
- count += rp->nreds;
- else
- consistent[i] = 1;
-
- if (sp)
- for (k = 0; k < sp->nshifts; k++)
- {
- if (accessing_symbol[sp->shifts[k]] == error_token_number)
- {
- consistent[i] = 0;
- break;
- }
- }
- }
+ size_t nLA = state_table[nstates].lookaheads;
+ if (!nLA)
+ nLA = 1;
- lookaheads[nstates] = count;
-
- if (count == 0)
- {
- LA = NEW2(1 * tokensetsize, unsigned);
- LAruleno = NEW2(1, short);
- lookback = NEW2(1, shorts *);
- }
- else
- {
- LA = NEW2(count * tokensetsize, unsigned);
- LAruleno = NEW2(count, short);
- lookback = NEW2(count, shorts *);
- }
+ LA = XCALLOC (unsigned, nLA * tokensetsize);
+ LAruleno = XCALLOC (short, nLA);
+ lookback = XCALLOC (shorts *, nLA);
np = LAruleno;
for (i = 0; i < nstates; i++)
- {
- if (!consistent[i])
- {
- if ((rp = reduction_table[i]))
- for (j = 0; j < rp->nreds; j++)
- *np++ = rp->rules[j];
- }
- }
+ if (!state_table[i].consistent)
+ if ((rp = state_table[i].reduction_table))
+ for (j = 0; j < rp->nreds; j++)
+ *np++ = rp->rules[j];
}
-void
+static void
set_goto_map (void)
{
- register shifts *sp;
- register int i;
- register int symbol;
- register int k;
- register short *temp_map;
- register int state2;
- register int state1;
+ shifts *sp;
+ int i;
+ int symbol;
+ int k;
+ short *temp_map;
+ int state2;
+ int state1;
- goto_map = NEW2(nvars + 1, short) - ntokens;
- temp_map = NEW2(nvars + 1, short) - ntokens;
+ 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; i--)
{
- symbol = accessing_symbol[sp->shifts[i]];
+ symbol = state_table[sp->shifts[i]].accessing_symbol;
- if (ISTOKEN(symbol)) break;
+ if (ISTOKEN (symbol))
+ break;
if (ngotos == MAXSHORT)
fatal (_("too many gotos (max %d)"), MAXSHORT);
ngotos++;
goto_map[symbol]++;
- }
+ }
}
k = 0;
goto_map[nsyms] = ngotos;
temp_map[nsyms] = ngotos;
- from_state = NEW2(ngotos, short);
- to_state = NEW2(ngotos, short);
+ from_state = XCALLOC (short, ngotos);
+ to_state = XCALLOC (short, ngotos);
for (sp = first_shift; sp; sp = sp->next)
{
for (i = sp->nshifts - 1; i >= 0; i--)
{
state2 = sp->shifts[i];
- symbol = accessing_symbol[state2];
+ symbol = state_table[state2].accessing_symbol;
- if (ISTOKEN(symbol)) break;
+ if (ISTOKEN (symbol))
+ break;
k = temp_map[symbol]++;
from_state[k] = state1;
}
}
- FREE(temp_map + ntokens);
+ XFREE (temp_map + ntokens);
}
-/* Map_goto maps a state/symbol pair into its numeric representation. */
+/*----------------------------------------------------------.
+| Map a state/symbol pair into its numeric representation. |
+`----------------------------------------------------------*/
-int
+static int
map_goto (int state, int symbol)
{
- register int high;
- register int low;
- register int middle;
- register int s;
+ int high;
+ int low;
+ int middle;
+ int s;
low = goto_map[symbol];
high = goto_map[symbol + 1] - 1;
middle = (low + high) / 2;
s = from_state[middle];
if (s == state)
- return (middle);
+ return middle;
else if (s < state)
low = middle + 1;
else
high = middle - 1;
}
- berror("map_goto");
-/* NOTREACHED */
+ assert (0);
+ /* NOTREACHED */
return 0;
}
-void
+static void
initialize_F (void)
{
- register int i;
- register int j;
- register int k;
- register shifts *sp;
- register short *edge;
- register unsigned *rowp;
- register short *rp;
- register short **reads;
- register int nedges;
- register int stateno;
- register int symbol;
- register int nwords;
+ int i;
+ int j;
+ int k;
+ shifts *sp;
+ short *edge;
+ unsigned *rowp;
+ short *rp;
+ short **reads;
+ int nedges;
+ int stateno;
+ int symbol;
+ int nwords;
nwords = ngotos * tokensetsize;
- F = NEW2(nwords, unsigned);
+ F = XCALLOC (unsigned, nwords);
- reads = NEW2(ngotos, short *);
- edge = NEW2(ngotos + 1, short);
+ reads = XCALLOC (short *, ngotos);
+ edge = XCALLOC (short, ngotos + 1);
nedges = 0;
rowp = F;
for (i = 0; i < ngotos; i++)
{
stateno = to_state[i];
- sp = shift_table[stateno];
+ sp = state_table[stateno].shift_table;
if (sp)
{
for (j = 0; j < k; j++)
{
- symbol = accessing_symbol[sp->shifts[j]];
- if (ISVAR(symbol))
+ symbol = state_table[sp->shifts[j]].accessing_symbol;
+ if (ISVAR (symbol))
break;
- SETBIT(rowp, symbol);
+ SETBIT (rowp, symbol);
}
for (; j < k; j++)
{
- symbol = accessing_symbol[sp->shifts[j]];
+ symbol = state_table[sp->shifts[j]].accessing_symbol;
if (nullable[symbol])
- edge[nedges++] = map_goto(stateno, symbol);
+ edge[nedges++] = map_goto (stateno, symbol);
}
if (nedges)
{
- reads[i] = rp = NEW2(nedges + 1, short);
+ reads[i] = rp = XCALLOC (short, nedges + 1);
for (j = 0; j < nedges; j++)
rp[j] = edge[j];
rowp += tokensetsize;
}
- digraph(reads);
+ digraph (reads);
for (i = 0; i < ngotos; i++)
- {
- if (reads[i])
- FREE(reads[i]);
- }
+ XFREE (reads[i]);
- FREE(reads);
- FREE(edge);
+ XFREE (reads);
+ XFREE (edge);
}
-void
-build_relations (void)
-{
- register int i;
- register int j;
- register int k;
- register short *rulep;
- register short *rp;
- register shifts *sp;
- register int length;
- register int nedges;
- register int done;
- register int state1;
- register int stateno;
- register int symbol1;
- register int symbol2;
- register short *shortp;
- register short *edge;
- register short *states;
- register short **new_includes;
-
- includes = NEW2(ngotos, short *);
- edge = NEW2(ngotos + 1, short);
- states = NEW2(maxrhs + 1, short);
-
- for (i = 0; i < ngotos; i++)
- {
- nedges = 0;
- state1 = from_state[i];
- symbol1 = accessing_symbol[to_state[i]];
-
- for (rulep = derives[symbol1]; *rulep > 0; rulep++)
- {
- length = 1;
- states[0] = state1;
- stateno = state1;
-
- for (rp = ritem + rrhs[*rulep]; *rp > 0; rp++)
- {
- symbol2 = *rp;
- sp = shift_table[stateno];
- k = sp->nshifts;
-
- for (j = 0; j < k; j++)
- {
- stateno = sp->shifts[j];
- if (accessing_symbol[stateno] == symbol2) break;
- }
-
- states[length++] = stateno;
- }
-
- if (!consistent[stateno])
- add_lookback_edge(stateno, *rulep, i);
-
- length--;
- done = 0;
- while (!done)
- {
- done = 1;
- rp--;
- /* JF added rp>=ritem && I hope to god its right! */
- if (rp>=ritem && ISVAR(*rp))
- {
- stateno = states[--length];
- edge[nedges++] = map_goto(stateno, *rp);
- if (nullable[*rp]) done = 0;
- }
- }
- }
-
- if (nedges)
- {
- includes[i] = shortp = NEW2(nedges + 1, short);
- for (j = 0; j < nedges; j++)
- shortp[j] = edge[j];
- shortp[nedges] = -1;
- }
- }
-
- new_includes = transpose(includes, ngotos);
-
- for (i = 0; i < ngotos; i++)
- if (includes[i])
- FREE(includes[i]);
-
- FREE(includes);
-
- includes = new_includes;
-
- FREE(edge);
- FREE(states);
-}
-
-
-void
+static void
add_lookback_edge (int stateno, int ruleno, int gotono)
{
- register int i;
- register int k;
- register int found;
- register shorts *sp;
+ int i;
+ int k;
+ int found;
+ shorts *sp;
- i = lookaheads[stateno];
- k = lookaheads[stateno + 1];
+ i = state_table[stateno].lookaheads;
+ k = state_table[stateno + 1].lookaheads;
found = 0;
while (!found && i < k)
{
i++;
}
- if (found == 0)
- berror("add_lookback_edge");
+ assert (found);
- sp = NEW(shorts);
+ sp = XCALLOC (shorts, 1);
sp->next = lookback[i];
sp->value = gotono;
lookback[i] = sp;
}
-
-short **
+static short **
transpose (short **R_arg, int n)
{
- register short **new_R;
- register short **temp_R;
- register short *nedges;
- register short *sp;
- register int i;
- register int k;
+ short **new_R;
+ short **temp_R;
+ short *nedges;
+ short *sp;
+ int i;
+ int k;
- nedges = NEW2(n, short);
+ nedges = XCALLOC (short, n);
for (i = 0; i < n; i++)
{
}
}
- new_R = NEW2(n, short *);
- temp_R = NEW2(n, short *);
+ new_R = XCALLOC (short *, n);
+ temp_R = XCALLOC (short *, n);
for (i = 0; i < n; i++)
{
k = nedges[i];
if (k > 0)
{
- sp = NEW2(k + 1, short);
+ sp = XCALLOC (short, k + 1);
new_R[i] = sp;
temp_R[i] = sp;
sp[k] = -1;
}
}
- FREE(nedges);
+ XFREE (nedges);
for (i = 0; i < n; i++)
{
}
}
- FREE(temp_R);
+ XFREE (temp_R);
- return (new_R);
+ return new_R;
}
-void
-compute_FOLLOWS (void)
+static void
+build_relations (void)
{
- register int i;
-
- digraph(includes);
+ int i;
+ int j;
+ int k;
+ short *rulep;
+ short *rp;
+ shifts *sp;
+ int length;
+ int nedges;
+ int done;
+ int state1;
+ int stateno;
+ int symbol1;
+ int symbol2;
+ short *shortp;
+ short *edge;
+ short *states;
+ short **new_includes;
+
+ includes = XCALLOC (short *, ngotos);
+ edge = XCALLOC (short, ngotos + 1);
+ states = XCALLOC (short, maxrhs () + 1);
for (i = 0; i < ngotos; i++)
{
- if (includes[i]) FREE(includes[i]);
- }
-
- FREE(includes);
-}
-
+ nedges = 0;
+ state1 = from_state[i];
+ symbol1 = state_table[to_state[i]].accessing_symbol;
-void
-compute_lookaheads (void)
-{
- register int i;
- register int n;
- register unsigned *fp1;
- register unsigned *fp2;
- register unsigned *fp3;
- register shorts *sp;
- register unsigned *rowp;
-/* register short *rulep; JF unused */
-/* register int count; JF unused */
- register shorts *sptmp;/* JF */
-
- rowp = LA;
- n = lookaheads[nstates];
- for (i = 0; i < n; i++)
- {
- fp3 = rowp + tokensetsize;
- for (sp = lookback[i]; sp; sp = sp->next)
+ for (rulep = derives[symbol1]; *rulep > 0; rulep++)
{
- fp1 = rowp;
- fp2 = F + tokensetsize * sp->value;
- while (fp1 < fp3)
- *fp1++ |= *fp2++;
- }
+ length = 1;
+ states[0] = state1;
+ stateno = state1;
- rowp = fp3;
- }
+ for (rp = ritem + rrhs[*rulep]; *rp > 0; rp++)
+ {
+ symbol2 = *rp;
+ sp = state_table[stateno].shift_table;
+ k = sp->nshifts;
- for (i = 0; i < n; i++)
- {/* JF removed ref to freed storage */
- for (sp = lookback[i]; sp; sp = sptmp) {
- sptmp=sp->next;
- FREE(sp);
- }
- }
+ for (j = 0; j < k; j++)
+ {
+ stateno = sp->shifts[j];
+ if (state_table[stateno].accessing_symbol == symbol2)
+ break;
+ }
- FREE(lookback);
- FREE(F);
-}
+ states[length++] = stateno;
+ }
+ if (!state_table[stateno].consistent)
+ add_lookback_edge (stateno, *rulep, i);
-void
-digraph (short **relation)
-{
- register int i;
+ length--;
+ done = 0;
+ while (!done)
+ {
+ done = 1;
+ rp--;
+ /* JF added rp>=ritem && I hope to god its right! */
+ if (rp >= ritem && ISVAR (*rp))
+ {
+ stateno = states[--length];
+ edge[nedges++] = map_goto (stateno, *rp);
+ if (nullable[*rp])
+ done = 0;
+ }
+ }
+ }
- infinity = ngotos + 2;
- INDEX = NEW2(ngotos + 1, short);
- VERTICES = NEW2(ngotos + 1, short);
- top = 0;
+ if (nedges)
+ {
+ includes[i] = shortp = XCALLOC (short, nedges + 1);
+ for (j = 0; j < nedges; j++)
+ shortp[j] = edge[j];
+ shortp[nedges] = -1;
+ }
+ }
- R = relation;
+ new_includes = transpose (includes, ngotos);
for (i = 0; i < ngotos; i++)
- INDEX[i] = 0;
+ if (includes[i])
+ XFREE (includes[i]);
- for (i = 0; i < ngotos; i++)
- {
- if (INDEX[i] == 0 && R[i])
- traverse(i);
- }
+ XFREE (includes);
- FREE(INDEX);
- FREE(VERTICES);
+ includes = new_includes;
+
+ XFREE (edge);
+ XFREE (states);
}
-void
-traverse (register int i)
-{
- register unsigned *fp1;
- register unsigned *fp2;
- register unsigned *fp3;
- register int j;
- register short *rp;
- int height;
- unsigned *base;
-
- VERTICES[++top] = i;
- INDEX[i] = height = top;
+static void
+compute_FOLLOWS (void)
+{
+ int i;
- base = F + i * tokensetsize;
- fp3 = base + tokensetsize;
+ digraph (includes);
- rp = R[i];
- if (rp)
- {
- while ((j = *rp++) >= 0)
- {
- if (INDEX[j] == 0)
- traverse(j);
+ for (i = 0; i < ngotos; i++)
+ XFREE (includes[i]);
- if (INDEX[i] > INDEX[j])
- INDEX[i] = INDEX[j];
+ XFREE (includes);
+}
- fp1 = base;
- fp2 = F + j * tokensetsize;
- while (fp1 < fp3)
- *fp1++ |= *fp2++;
- }
- }
+static void
+compute_lookaheads (void)
+{
+ int i;
+ shorts *sp;
+
+ for (i = 0; i < state_table[nstates].lookaheads; i++)
+ for (sp = lookback[i]; sp; sp = sp->next)
+ {
+ unsigned *fp1 = LA (i);
+ unsigned *fp2 = F (sp->value);
+ while (fp1 < LA (i + 1))
+ *fp1++ |= *fp2++;
+ }
- if (INDEX[i] == height)
+ /* Free LOOKBACK. */
+ for (i = 0; i < state_table[nstates].lookaheads; i++)
{
- for (;;)
+ shorts *sptmp;
+ for (sp = lookback[i]; sp; sp = sptmp)
{
- j = VERTICES[top--];
- INDEX[j] = infinity;
+ sptmp = sp->next;
+ XFREE (sp);
+ }
+ }
- if (i == j)
- break;
+ XFREE (lookback);
+ XFREE (F);
+}
- fp1 = base;
- fp2 = F + j * tokensetsize;
- while (fp1 < fp3)
- *fp2++ = *fp1++;
- }
- }
+void
+lalr (void)
+{
+ tokensetsize = WORDSIZE (ntokens);
+
+ set_state_table ();
+ initialize_LA ();
+ set_goto_map ();
+ initialize_F ();
+ build_relations ();
+ compute_FOLLOWS ();
+ compute_lookaheads ();
}
projects / bison.git / blobdiff