703 lines
12 KiB
C
703 lines
12 KiB
C
/* $NetBSD: lalr.c,v 1.8 2003/08/07 11:17:53 agc Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1989 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Robert Paul Corbett.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#if defined(__RCSID) && !defined(lint)
|
|
#if 0
|
|
static char sccsid[] = "@(#)lalr.c 5.3 (Berkeley) 6/1/90";
|
|
#else
|
|
__RCSID("$NetBSD: lalr.c,v 1.8 2003/08/07 11:17:53 agc Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
|
|
#include "defs.h"
|
|
|
|
typedef
|
|
struct shorts
|
|
{
|
|
struct shorts *next;
|
|
short value;
|
|
}
|
|
shorts;
|
|
|
|
int tokensetsize;
|
|
short *lookaheads;
|
|
short *LAruleno;
|
|
unsigned *LA;
|
|
short *accessing_symbol;
|
|
core **state_table;
|
|
shifts **shift_table;
|
|
reductions **reduction_table;
|
|
short *goto_map;
|
|
short *from_state;
|
|
short *to_state;
|
|
|
|
short **transpose(short **, int);
|
|
void set_state_table __P((void));
|
|
void set_accessing_symbol __P((void));
|
|
void set_shift_table __P((void));
|
|
void set_reduction_table __P((void));
|
|
void set_maxrhs __P((void));
|
|
void initialize_LA __P((void));
|
|
void set_goto_map __P((void));
|
|
void initialize_F __P((void));
|
|
void build_relations __P((void));
|
|
void compute_FOLLOWS __P((void));
|
|
void compute_lookaheads __P((void));
|
|
|
|
int map_goto __P((int, int));
|
|
void digraph __P((short **));
|
|
void add_lookback_edge __P((int, int, int));
|
|
void traverse __P((int));
|
|
|
|
|
|
static int infinity;
|
|
static int maxrhs;
|
|
static int ngotos;
|
|
static unsigned *F;
|
|
static short **includes;
|
|
static shorts **lookback;
|
|
static short **R;
|
|
static short *INDEX;
|
|
static short *VERTICES;
|
|
static int top;
|
|
|
|
void
|
|
lalr()
|
|
{
|
|
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();
|
|
}
|
|
|
|
|
|
void
|
|
set_state_table()
|
|
{
|
|
core *sp;
|
|
|
|
state_table = NEW2(nstates, core *);
|
|
for (sp = first_state; sp; sp = sp->next)
|
|
state_table[sp->number] = sp;
|
|
}
|
|
|
|
|
|
void
|
|
set_accessing_symbol()
|
|
{
|
|
core *sp;
|
|
|
|
accessing_symbol = NEW2(nstates, short);
|
|
for (sp = first_state; sp; sp = sp->next)
|
|
accessing_symbol[sp->number] = sp->accessing_symbol;
|
|
}
|
|
|
|
|
|
void
|
|
set_shift_table()
|
|
{
|
|
shifts *sp;
|
|
|
|
shift_table = NEW2(nstates, shifts *);
|
|
for (sp = first_shift; sp; sp = sp->next)
|
|
shift_table[sp->number] = sp;
|
|
}
|
|
|
|
|
|
void
|
|
set_reduction_table()
|
|
{
|
|
reductions *rp;
|
|
|
|
reduction_table = NEW2(nstates, reductions *);
|
|
for (rp = first_reduction; rp; rp = rp->next)
|
|
reduction_table[rp->number] = rp;
|
|
}
|
|
|
|
|
|
void
|
|
set_maxrhs()
|
|
{
|
|
short *itemp;
|
|
short *item_end;
|
|
int length;
|
|
int max;
|
|
|
|
length = 0;
|
|
max = 0;
|
|
item_end = ritem + nitems;
|
|
for (itemp = ritem; itemp < item_end; itemp++)
|
|
{
|
|
if (*itemp >= 0)
|
|
{
|
|
length++;
|
|
}
|
|
else
|
|
{
|
|
if (length > max) max = length;
|
|
length = 0;
|
|
}
|
|
}
|
|
|
|
maxrhs = max;
|
|
}
|
|
|
|
|
|
void
|
|
initialize_LA()
|
|
{
|
|
int i, j, k;
|
|
reductions *rp;
|
|
|
|
lookaheads = NEW2(nstates + 1, short);
|
|
|
|
k = 0;
|
|
for (i = 0; i < nstates; i++)
|
|
{
|
|
lookaheads[i] = k;
|
|
rp = reduction_table[i];
|
|
if (rp)
|
|
k += rp->nreds;
|
|
}
|
|
lookaheads[nstates] = k;
|
|
|
|
LA = NEW2(k * tokensetsize, unsigned);
|
|
LAruleno = NEW2(k, short);
|
|
lookback = NEW2(k, shorts *);
|
|
|
|
k = 0;
|
|
for (i = 0; i < nstates; i++)
|
|
{
|
|
rp = reduction_table[i];
|
|
if (rp)
|
|
{
|
|
for (j = 0; j < rp->nreds; j++)
|
|
{
|
|
LAruleno[k] = rp->rules[j];
|
|
k++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
set_goto_map()
|
|
{
|
|
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;
|
|
|
|
ngotos = 0;
|
|
for (sp = first_shift; sp; sp = sp->next)
|
|
{
|
|
for (i = sp->nshifts - 1; i >= 0; i--)
|
|
{
|
|
symbol = accessing_symbol[sp->shift[i]];
|
|
|
|
if (ISTOKEN(symbol)) break;
|
|
|
|
if (ngotos == MAXSHORT)
|
|
fatal("too many gotos");
|
|
|
|
ngotos++;
|
|
goto_map[symbol]++;
|
|
}
|
|
}
|
|
|
|
k = 0;
|
|
for (i = ntokens; i < nsyms; i++)
|
|
{
|
|
temp_map[i] = k;
|
|
k += goto_map[i];
|
|
}
|
|
|
|
for (i = ntokens; i < nsyms; i++)
|
|
goto_map[i] = temp_map[i];
|
|
|
|
goto_map[nsyms] = ngotos;
|
|
temp_map[nsyms] = ngotos;
|
|
|
|
from_state = NEW2(ngotos, short);
|
|
to_state = NEW2(ngotos, short);
|
|
|
|
for (sp = first_shift; sp; sp = sp->next)
|
|
{
|
|
state1 = sp->number;
|
|
for (i = sp->nshifts - 1; i >= 0; i--)
|
|
{
|
|
state2 = sp->shift[i];
|
|
symbol = accessing_symbol[state2];
|
|
|
|
if (ISTOKEN(symbol)) break;
|
|
|
|
k = temp_map[symbol]++;
|
|
from_state[k] = state1;
|
|
to_state[k] = state2;
|
|
}
|
|
}
|
|
|
|
FREE(temp_map + ntokens);
|
|
}
|
|
|
|
|
|
|
|
/* Map_goto maps a state/symbol pair into its numeric representation. */
|
|
|
|
int
|
|
map_goto(state, symbol)
|
|
int state;
|
|
int symbol;
|
|
{
|
|
int high;
|
|
int low;
|
|
int middle;
|
|
int s;
|
|
|
|
low = goto_map[symbol];
|
|
high = goto_map[symbol + 1];
|
|
|
|
for (;;)
|
|
{
|
|
assert(low <= high);
|
|
middle = (low + high) >> 1;
|
|
s = from_state[middle];
|
|
if (s == state)
|
|
return (middle);
|
|
else if (s < state)
|
|
low = middle + 1;
|
|
else
|
|
high = middle - 1;
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
initialize_F()
|
|
{
|
|
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);
|
|
|
|
reads = NEW2(ngotos, short *);
|
|
edge = NEW2(ngotos + 1, short);
|
|
nedges = 0;
|
|
|
|
rowp = F;
|
|
for (i = 0; i < ngotos; i++)
|
|
{
|
|
stateno = to_state[i];
|
|
sp = shift_table[stateno];
|
|
|
|
if (sp)
|
|
{
|
|
k = sp->nshifts;
|
|
|
|
for (j = 0; j < k; j++)
|
|
{
|
|
symbol = accessing_symbol[sp->shift[j]];
|
|
if (ISVAR(symbol))
|
|
break;
|
|
SETBIT(rowp, symbol);
|
|
}
|
|
|
|
for (; j < k; j++)
|
|
{
|
|
symbol = accessing_symbol[sp->shift[j]];
|
|
if (nullable[symbol])
|
|
edge[nedges++] = map_goto(stateno, symbol);
|
|
}
|
|
|
|
if (nedges)
|
|
{
|
|
reads[i] = rp = NEW2(nedges + 1, short);
|
|
|
|
for (j = 0; j < nedges; j++)
|
|
rp[j] = edge[j];
|
|
|
|
rp[nedges] = -1;
|
|
nedges = 0;
|
|
}
|
|
}
|
|
|
|
rowp += tokensetsize;
|
|
}
|
|
|
|
SETBIT(F, 0);
|
|
digraph(reads);
|
|
|
|
for (i = 0; i < ngotos; i++)
|
|
{
|
|
if (reads[i])
|
|
FREE(reads[i]);
|
|
}
|
|
|
|
FREE(reads);
|
|
FREE(edge);
|
|
}
|
|
|
|
|
|
void
|
|
build_relations()
|
|
{
|
|
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 = 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->shift[j];
|
|
if (accessing_symbol[stateno] == symbol2) break;
|
|
}
|
|
|
|
states[length++] = stateno;
|
|
}
|
|
|
|
add_lookback_edge(stateno, *rulep, i);
|
|
|
|
length--;
|
|
done = 0;
|
|
while (!done)
|
|
{
|
|
done = 1;
|
|
rp--;
|
|
if (ISVAR(*rp))
|
|
{
|
|
stateno = states[--length];
|
|
edge[nedges++] = map_goto(stateno, *rp);
|
|
if (nullable[*rp] && length > 0) 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
|
|
add_lookback_edge(stateno, ruleno, gotono)
|
|
int stateno, ruleno, gotono;
|
|
{
|
|
int i, k;
|
|
int found;
|
|
shorts *sp;
|
|
|
|
i = lookaheads[stateno];
|
|
k = lookaheads[stateno + 1];
|
|
found = 0;
|
|
while (!found && i < k)
|
|
{
|
|
if (LAruleno[i] == ruleno)
|
|
found = 1;
|
|
else
|
|
++i;
|
|
}
|
|
assert(found);
|
|
|
|
sp = NEW(shorts);
|
|
sp->next = lookback[i];
|
|
sp->value = gotono;
|
|
lookback[i] = sp;
|
|
}
|
|
|
|
|
|
|
|
short **
|
|
transpose(R, n)
|
|
short **R;
|
|
int n;
|
|
{
|
|
short **new_R;
|
|
short **temp_R;
|
|
short *nedges;
|
|
short *sp;
|
|
int i;
|
|
int k;
|
|
|
|
nedges = NEW2(n, short);
|
|
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
sp = R[i];
|
|
if (sp)
|
|
{
|
|
while (*sp >= 0)
|
|
nedges[*sp++]++;
|
|
}
|
|
}
|
|
|
|
new_R = NEW2(n, short *);
|
|
temp_R = NEW2(n, short *);
|
|
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
k = nedges[i];
|
|
if (k > 0)
|
|
{
|
|
sp = NEW2(k + 1, short);
|
|
new_R[i] = sp;
|
|
temp_R[i] = sp;
|
|
sp[k] = -1;
|
|
}
|
|
}
|
|
|
|
FREE(nedges);
|
|
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
sp = R[i];
|
|
if (sp)
|
|
{
|
|
while (*sp >= 0)
|
|
*temp_R[*sp++]++ = i;
|
|
}
|
|
}
|
|
|
|
FREE(temp_R);
|
|
|
|
return (new_R);
|
|
}
|
|
|
|
|
|
void
|
|
compute_FOLLOWS()
|
|
{
|
|
digraph(includes);
|
|
}
|
|
|
|
|
|
void
|
|
compute_lookaheads()
|
|
{
|
|
int i, n;
|
|
unsigned *fp1, *fp2, *fp3;
|
|
shorts *sp, *next;
|
|
unsigned *rowp;
|
|
|
|
rowp = LA;
|
|
n = lookaheads[nstates];
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
fp3 = rowp + tokensetsize;
|
|
for (sp = lookback[i]; sp; sp = sp->next)
|
|
{
|
|
fp1 = rowp;
|
|
fp2 = F + tokensetsize * sp->value;
|
|
while (fp1 < fp3)
|
|
*fp1++ |= *fp2++;
|
|
}
|
|
rowp = fp3;
|
|
}
|
|
|
|
for (i = 0; i < n; i++)
|
|
for (sp = lookback[i]; sp; sp = next)
|
|
{
|
|
next = sp->next;
|
|
FREE(sp);
|
|
}
|
|
|
|
FREE(lookback);
|
|
FREE(F);
|
|
}
|
|
|
|
|
|
void
|
|
digraph(relation)
|
|
short **relation;
|
|
{
|
|
int i;
|
|
|
|
infinity = ngotos + 2;
|
|
INDEX = NEW2(ngotos + 1, short);
|
|
VERTICES = NEW2(ngotos + 1, short);
|
|
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);
|
|
}
|
|
|
|
FREE(INDEX);
|
|
FREE(VERTICES);
|
|
}
|
|
|
|
|
|
void
|
|
traverse(i)
|
|
int i;
|
|
{
|
|
unsigned *fp1;
|
|
unsigned *fp2;
|
|
unsigned *fp3;
|
|
int j;
|
|
short *rp;
|
|
|
|
int height;
|
|
unsigned *base;
|
|
|
|
VERTICES[++top] = i;
|
|
INDEX[i] = height = top;
|
|
|
|
base = F + i * tokensetsize;
|
|
fp3 = base + tokensetsize;
|
|
|
|
rp = R[i];
|
|
if (rp)
|
|
{
|
|
while ((j = *rp++) >= 0)
|
|
{
|
|
if (INDEX[j] == 0)
|
|
traverse(j);
|
|
|
|
if (INDEX[i] > INDEX[j])
|
|
INDEX[i] = INDEX[j];
|
|
|
|
fp1 = base;
|
|
fp2 = F + j * tokensetsize;
|
|
|
|
while (fp1 < fp3)
|
|
*fp1++ |= *fp2++;
|
|
}
|
|
}
|
|
|
|
if (INDEX[i] == height)
|
|
{
|
|
for (;;)
|
|
{
|
|
j = VERTICES[top--];
|
|
INDEX[j] = infinity;
|
|
|
|
if (i == j)
|
|
break;
|
|
|
|
fp1 = base;
|
|
fp2 = F + j * tokensetsize;
|
|
|
|
while (fp1 < fp3)
|
|
*fp2++ = *fp1++;
|
|
}
|
|
}
|
|
}
|