ack/util/LLgen/lib/rec
1991-11-26 15:38:41 +00:00

292 lines
5.3 KiB
Plaintext

/*
* Some grammar independent code.
* This file is copied into Lpars.c.
*/
#ifndef lint
static char *rcsid = "$Header$";
#endif
unsigned int LLtcnt[LL_NTERMINALS];
unsigned int LLscnt[LL_NSETS];
int LLcsymb, LLsymb;
static int LLlevel;
#if LL_ANSI_C
void LLmessage(int);
#endif
#ifdef LL_USERHOOK
#if LL_ANSI_C
static void LLdoskip(int);
static int LLuserhook(int, int*);
#else
static LLdoskip();
static int LLuserhook();
#endif
#endif
#ifndef LL_FASTER
#if LL_ANSI_C
void LLscan(int t)
#else
LLscan(t)
int t;
#endif
{
/*
* Check if the next symbol is equal to the parameter
*/
if ((LLsymb = LL_LEXI()) == t) {
return;
}
/*
* If we come here, an error has been detected
*/
LLerror(t);
}
#endif
#if LL_ANSI_C
void LLread(void) {
#else
LLread() {
#endif
for (;;) {
if ((LLcsymb = LLindex[(LLsymb = LL_LEXI())]) >= 0) return;
LLmessage(0);
}
/* NOTREACHED */
}
#if LL_ANSI_C
void LLerror(int t)
#else
LLerror(t)
int t;
#endif
{
register int i;
if (t == EOFILE && LLsymb <= 0) return;
#ifdef LL_NEWMESS
if (t == EOFILE) {
#ifdef LL_USERHOOK
static int lst[] = { EOFILE, 0 };
if (LLuserhook(EOFILE, lst)) /* nothing */;
#endif /* LL_USERHOOK */
if (LLsymb != EOFILE && LLsymb > 0) {
LLmessage(-1);
while ((LLsymb = LL_LEXI()) > 0 && LLsymb != EOFILE)
/* nothing */ ;
}
return;
}
#endif
if ((LLcsymb = LLindex[LLsymb]) < 0) {
LLmessage(0);
LLread();
}
i = LLindex[t];
LLtcnt[i]++;
#ifdef LL_USERHOOK
if (LLdoskip(t)) /* nothing */;
#else
if (LLskip()) /* nothing */;
#endif
LLtcnt[i]--;
if (LLsymb != t) LLmessage(t);
}
#ifndef LLNOFIRSTS
#if LL_ANSI_C
int LLfirst(int x, int d) {
#else
int LLfirst(x, d) {
#endif
register int i;
return (i = LLindex[x]) >= 0 &&
(LLsets[d + (i >> 3)] & (1 << (i & 07)));
}
#endif
#if LL_ANSI_C
int LLnext(int n)
#else
int LLnext(n)
int n;
#endif
{
/* returns: 0 if the current symbol is'nt skipped, and it
is'nt a member of "n",
1 if we have a new symbol, but it is'nt a member,
2 if the current symbol is a member,
and 3 if we have a new symbol and it is a member.
So, the low order bit indicates wether we have a new symbol,
and the next bit indicates wether it is a member of "n".
*/
int retval = 0;
if (LLskip()) retval = 1;
if (n <= 0 && LLsets[(LLcsymb >> 3) - n] & (1 << (LLcsymb & 07))) {
retval |= 2;
}
else if (n > 0 && LLcsymb == LLindex[n]) retval |= 2;
return retval;
}
#if LL_ANSI_C
int LLskip(void) {
#else
int LLskip() {
#endif
/* returns 0 if the current symbol is'nt skipped, and
1 if it is, t.i., we have a new symbol
*/
#ifdef LL_USERHOOK
return LLdoskip(0);
}
#if LL_ANSI_C
extern void LL_USERHOOK(int, int *);
static int LLuserhook(int e, int *list)
#else
static int LLuserhook(e, list)
int e;
int *list;
#endif
{
int old = LLsymb;
LL_USERHOOK(e, list);
LLread();
return LLsymb != old;
}
#if LL_ANSI_C
static void LLmklist(register int *list)
#else
static LLmklist(list)
register int *list;
#endif
{
char Xset[LL_SSIZE];
register char *p;
register int i;
for (p = &Xset[0]; p < &Xset[LL_SSIZE]; ) *p++ = 0;
for (i = 0; i < LL_NTERMINALS; i++) {
if (LLtcnt[i] != 0) Xset[i >> 3] |= (1 << (i & 07));
}
for (i = LL_NSETS - 1; i >= 0; i--) if (LLscnt[i] != 0) {
register char *q = &LLsets[LL_SSIZE * i];
p = &Xset[0];
while (p < &Xset[LL_SSIZE]) *p++ |= *q++;
}
for (i = 0; i < LL_NTERMINALS; i++) {
if (Xset[i >> 3] & (1 << (i & 07))) {
*list++ = LLtok[i];
}
}
*list = 0;
}
#if LL_ANSI_C
static int LLdoskip(int e)
#else
static int LLdoskip(e)
int e;
#endif
{
int LLx;
int list[LL_NTERMINALS+1];
#endif /* LL_USERHOOK */
register int i;
int retval;
int LLi, LLb;
retval = 0;
#ifdef LL_USERHOOK
LLmklist(list);
LLx = LLuserhook(e, list);
if (LLx) retval = 1;
#endif /* LL_USERHOOK */
for (;;) {
if (LLtcnt[LLcsymb] != 0) {
#ifdef LL_USERHOOK
if (!e || !LLx || LLcsymb == LLindex[e])
#endif
return retval;
}
LLi = LLcsymb >> 3;
LLb = 1 << (LLcsymb & 07);
for (i = LL_NSETS - 1; i >= 0; i--) {
if (LLscnt[i] != 0) {
if (LLsets[LL_SSIZE*i+LLi] & LLb) {
#ifdef LL_USERHOOK
if (!e || !LLx || LLcsymb == LLindex[e])
#endif
return retval;
}
}
}
#ifdef LL_USERHOOK
if (LLx) {
LLx = LLuserhook(e, list);
continue;
}
#endif /* LL_USERHOOK */
LLmessage(0);
retval = 1;
LLread();
}
/* NOTREACHED */
}
#if LL_ANSI_C
void LLnewlevel(unsigned int *LLsinfo) {
#else
LLnewlevel(LLsinfo) unsigned int *LLsinfo; {
#endif
register int i;
if (LLlevel++) {
LLsinfo[LL_NSETS+LL_NTERMINALS] = (unsigned) LLsymb;
LLsinfo[LL_NSETS+LL_NTERMINALS+1] = (unsigned) LLcsymb;
for (i = LL_NTERMINALS - 1; i >= 0; i--) {
LLsinfo[i] = LLtcnt[i];
LLtcnt[i] = 0;
}
for (i = LL_NSETS - 1; i >= 0; i--) {
LLsinfo[LL_NTERMINALS+i] = LLscnt[i];
LLscnt[i] = 0;
}
}
LLtincr(0);
}
#if LL_ANSI_C
void LLoldlevel(unsigned int *LLsinfo) {
#else
LLoldlevel(LLsinfo) unsigned int *LLsinfo; {
#endif
register int i;
LLtdecr(0);
#ifdef LL_DEBUG
for (i = 0; i < LL_NTERMINALS; i++) LL_assert(LLtcnt[i] == 0);
for (i = 0; i < LL_NSETS; i++) LL_assert(LLscnt[i] == 0);
#endif
if (--LLlevel) {
for (i = LL_NSETS - 1; i >= 0; i--) {
LLscnt[i] = LLsinfo[LL_NTERMINALS+i];
}
for (i = LL_NTERMINALS - 1; i >= 0; i--) {
LLtcnt[i] = LLsinfo[i];
}
LLsymb = (int) LLsinfo[LL_NSETS+LL_NTERMINALS];
LLcsymb = (int) LLsinfo[LL_NSETS+LL_NTERMINALS+1];
}
}