ack/util/LLgen/lib/rec
1987-02-23 10:50:15 +00:00

177 lines
3.2 KiB
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/*
* Some grammar independent code.
* This file is copied into Lpars.c.
*/
# ifndef lint
static char *rcsid = "$Header$";
# endif
# ifdef LL_DEBUG
# include <stdio.h>
# endif
int LLsymb;
unsigned int LLtcnt[LL_NTERMINALS];
unsigned int LLscnt[LL_NSETS];
int LLcsymb, LLsymb;
static int LLlevel;
/* In this file are defined: */
extern LLread();
extern int LLskip();
extern int LLnext();
extern LLscan();
extern LLerror();
# ifndef LLNOFIRSTS
extern int LLfirst();
# endif
extern LLnewlevel();
extern LLoldlevel();
LLscan(t) {
/*
* Check if the next symbol is equal to the parameter
*/
if ((LLsymb = LL_LEXI()) <= 0) LLsymb = EOFILE;
if (LLsymb == t) {
return;
}
/*
* If we come here, an error has been detected
*/
LLerror(t);
}
LLread() {
for (;;) {
if ((LLsymb = LL_LEXI()) <= 0) LLsymb = EOFILE;
if ((LLcsymb = LLindex[LLsymb]) >= 0) return;
LLmessage(0);
}
/* NOTREACHED */
}
LLerror(t) {
register int i;
#ifdef LL_NEWMESS
if (t == EOFILE) {
LLmessage(-1);
while ((LLsymb = LL_LEXI()) > 0) /* 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
LLfirst(x, d) {
register int i;
return (i = LLindex[x]) >= 0 &&
(LLsets[d + (i >> 3)] & (1 << (i & 07)));
}
# endif
LLnext(n) {
if (LLskip()) /* nothing */;
if (n <= 0) return (LLsets[(LLcsymb >> 3) - n] & (1 << (LLcsymb & 07)));
return LLsymb == n;
}
LLskip() {
#ifdef LL_USERHOOK
return LLdoskip(0);
}
LLdoskip(exp) {
#endif LL_USERHOOK
register int i;
int retval;
int LLi, LLb;
retval = 0;
for (;;) {
if (LLtcnt[LLcsymb] != 0) 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) return retval;
}
}
#ifdef LL_USERHOOK
{
int old = LLsymb;
LL_USERHOOK(exp);
LLread();
if (LLsymb != old) continue;
}
#endif LL_USERHOOK
LLmessage(0);
retval = 1;
LLread();
}
/* NOTREACHED */
}
LLnewlevel(LLsinfo) unsigned int *LLsinfo; {
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);
}
LLoldlevel(LLsinfo) unsigned int *LLsinfo; {
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];
}
}
# ifdef LL_DEBUG
LL_badassertion(asstr,file,line) char *asstr, *file; {
fprintf(stderr,"Assertion \"%s\" failed %s(%d)\n",asstr,file,line);
abort();
}
# endif