y1.c

整理 unix v7 的 ya

#include "dextern.h"

/*
 * variables used locally
 * lookahead computations
 */
int tbitset;  /* size of lookahead sets */
struct looksets lkst [LSETSIZE];
int nlset = 0; /* next lookahead set index */
int nolook = 0; /* flag to suppress lookahead computations */
struct looksets clset;  /* temporary storage for lookahead computations */

/*
 * working set computations
 */
struct wset wsets[WSETSIZE];
struct wset *cwp;

/*
 * state information
 */
int nstate = 0;		/* number of states */
struct item *pstate[NSTATES+2];	/* pointers to the descriptions of the states */
int tystate[NSTATES];	/* contains type information about the states */
int indgo[NSTATES];		/* index to the stored goto table */
int tstates[NTERMS]; /* states generated by terminal gotos */
int ntstates[NNONTERM]; /* states generated by nonterminal gotos */
int mstates[NSTATES]; /* chain of overflows of term/nonterm generation lists  */

/*
 * storage for the actions in the parser
 */
int amem[ACTSIZE];	/* action table storage */
int *memp = amem;	/* next free action table position */

/*
 * other storage areas
 */
int temp1[TEMPSIZE]; /* temporary storage, indexed by terms + ntokens or states */
int lineno= 1; /* current input line number */
int fatfl = 1;  	/* if on, error is fatal */
int nerrors = 0;	/* number of errors */

/*
 * storage for information about the nonterminals
 */
int **pres[NNONTERM+2];  /* vector of pointers to productions yielding each nonterminal */
struct looksets *pfirst[NNONTERM+2];  /* vector of pointers to first sets for each nonterminal */
int pempty[NNONTERM+1];  /* vector of nonterminals nontrivially deriving e */

void others(void);
char *chcopy(char *p, char *q);
char *writem(int *pp);
char *symnam(int i);
void summary(void);
void error(char *s, ...);
void aryfil(int *v, int n, int c);
int  setunion(register int *a, register int *b);
void prlook(struct looksets *p);
void cpres(void);
void cpfir(void);
int  state(int c);
void putitem(int *ptr, struct looksets *lptr);
void cempty(void);
void stagen(void);
void closure(int i);
struct looksets *flset(struct looksets *p);

int main(int argc,char *argv[])
{
	setup(argc,argv);
	yyparse(); /* initialize and read productions */
	tbitset = NWORDS(ntokens);
	cpres(); /* make table of which productions yield a given nonterminal */
	cempty(); /* make a table of which nonterminals can match the empty string */
	cpfir(); /* make a table of firsts of nonterminals */
	stagen(); /* generate the states */
	output();  /* write the states and the tables */
	go2out();
	hideprod();
	summary();
	callopt();
	others();
	return 0;
}
/*
 * put out other arrays, copy the parsers
 */
void others(void)
{
	register int c, i, j;

	finput = fopen(PARSER, "r");
	if(finput == NULL)
		error("cannot find parser %s", PARSER);

	warray("yyr1", levprd, nprod);

	aryfil(temp1, nprod, 0);
	PLOOP(1,i)
		temp1[i] = prdptr[i+1]-prdptr[i]-2;
	warray("yyr2", temp1, nprod);

	aryfil(temp1, nstate, -1000);
	TLOOP(i){
		for(j=tstates[i]; j!=0; j=mstates[j]){
			temp1[j] = tokset[i].value;
		}
	}
	NTLOOP(i){
		for(j=ntstates[i]; j!=0; j=mstates[j]){
			temp1[j] = -i;
		}
	}
	warray("yychk", temp1, nstate);

	warray("yydef", defact, nstate);

	/* copy parser text */

	while((c=getc(finput)) != EOF){
		if(c == '$'){
			if((c=getc(finput)) != 'A')
				putc('$', ftable);
			else { /* copy actions */
				faction = fopen(ACTNAME, "r");
				if(faction == NULL)
					error("cannot reopen action tempfile");
				while((c=getc(faction)) != EOF)
					putc(c, ftable);
				fclose(faction);
				ZAPFILE(ACTNAME);
				c = getc(finput);
			}
		}
		putc(c, ftable);
	}

	fclose(ftable);
}
/*
 * copies string q into p, returning next free char ptr
 */
char *chcopy(char *p, char *q)
{

	while((*p = *q++))
		++p;
	return(p);
}

#define ISIZE 400
/*
 * creates output string for item pointed to by pp
 */
char *writem(int *pp)
{
	int i,*p;
	static char sarr[ISIZE];
	char *q;

	for(p=pp; *p>0 ; ++p) ;
	p = prdptr[-*p];
	q = chcopy(sarr, nontrst[*p-NTBASE].name);
	q = chcopy(q, " : ");

	for(;;){
		*q++ = ++p==pp ? '_' : ' ';
		*q = '\0';
		if((i = *p) <= 0)
			break;
		q = chcopy(q, symnam(i));
		if(q> &sarr[ISIZE-30])
			error("item too big");
	}

	if((i = *pp) < 0){ /* an item calling for a reduction */
		q = chcopy(q, "    (");
		sprintf(q, "%d)", -i);
	}

	return(sarr);
}
/*
 * return a pointer to the name of symbol i
 */
char *symnam(int i)
{
	char *cp;

	cp = (i>=NTBASE) ? nontrst[i-NTBASE].name : tokset[i].name ;
	if(*cp == ' ')
		++cp;
	return(cp);
}

struct wset *zzcwp = wsets;
int zzgoent = 0;
int zzgobest = 0;
int zzacent = 0;
int zzexcp = 0;
int zzclose = 0;
int zzsrconf = 0;
int * zzmemsz = mem0;
int zzrrconf = 0;

/*
 * output the summary on the tty
 */
void summary(void)
{

	if(foutput!=NULL){
		fprintf(foutput, "\n%d/%d terminals, %d/%d nonterminals\n", ntokens, NTERMS,
			    nnonter, NNONTERM);
		fprintf(foutput, "%d/%d grammar rules, %d/%d states\n", nprod, NPROD, nstate, NSTATES);
		fprintf(foutput, "%d shift/reduce, %d reduce/reduce conflicts reported\n", zzsrconf, zzrrconf);
		fprintf(foutput, "%d/%d working sets used\n", zzcwp-wsets,  WSETSIZE);
		fprintf(foutput, "memory: states,etc. %d/%d, parser %d/%d\n", zzmemsz-mem0, MEMSIZE,
			    memp-amem, ACTSIZE);
		fprintf(foutput, "%d/%d distinct lookahead sets\n", nlset, LSETSIZE);
		fprintf(foutput, "%d extra closures\n", zzclose - 2*nstate);
		fprintf(foutput, "%d shift entries, %d exceptions\n", zzacent, zzexcp);
		fprintf(foutput, "%d goto entries\n", zzgoent);
		fprintf(foutput, "%d entries saved by goto default\n", zzgobest);
	}
	if(zzsrconf!=0 || zzrrconf!=0){
		fprintf(stdout,"\nconflicts: ");
		if(zzsrconf)
			fprintf(stdout, "%d shift/reduce" , zzsrconf);
		if(zzsrconf && zzrrconf)
			fprintf(stdout, ", ");
		if(zzrrconf)
			fprintf(stdout, "%d reduce/reduce" , zzrrconf);
		fprintf(stdout, "\n");
	}

	fclose(ftemp);
	if(fdefine != NULL)
		fclose(fdefine);
}

/* VARARGS1 */
/*
 * write out error comment
 */
void error(char *s, ...)
{ 
	va_list ap;
	void * a;

	va_start(ap, s);
	++nerrors;
	fprintf(stderr, "\n fatal error: ");
	a=va_arg(ap, void*);
	fprintf(stderr, s, a, va_arg(ap,void*));
	va_end(ap);
	fprintf(stderr, ", line %d\n", lineno);
	if(!fatfl)
		return;
	summary();
	ZAPFILE(ACTNAME);
	ZAPFILE(TEMPNAME);
	ZAPFILE(OFILE);
	if (fdefine != NULL)
		ZAPFILE(FILED);
	exit(1);
}
/*
 * set elements 0 through n-1 to c
 */
void aryfil(int *v, int n, int c)
{
	int i;
	for(i=0; i<n; ++i)
		v[i] = c;
}

/*
 * set a to the union of a and b
 * return 1 if b is not a subset of a, 0 otherwise
 */
int setunion(register int *a, register int *b)
{

	register int i, x, sub;

	sub = 0;
	SETLOOP(i){
		*a = (x = *a)|*b++;
		if(*a++ != x)
			sub = 1;
	}
	return(sub);
}

void prlook(struct looksets *p)
{
	register int j, *pp;
	pp = p->lset;
	if(pp == 0) 
		fprintf(foutput, "\tNULL");
	else {
		fprintf(foutput, " { ");
		TLOOP(j) {
			if(BIT(pp,j))
				fprintf(foutput,  "%s ", symnam(j));
		}
		fprintf(foutput,  "}");
	}
}
/*
 * compute an array with the beginnings of  productions yielding given nonterminals
 * The array pres points to these lists
 * the array pyield has the lists: the total size is only NPROD+1
 */
void cpres(void)
{
	register int **pmem;
	register int c, j, i;
	static int * pyield[NPROD];

	pmem = pyield;

	NTLOOP(i){
		c = i+NTBASE;
		pres[i] = pmem;
		fatfl = 0;  /* make undefined  symbols  nonfatal */
		PLOOP(0,j){
			if (*prdptr[j] == c)
				*pmem++ =  prdptr[j]+1;
		}
		if(pres[i] == pmem){
			error("nonterminal %s not defined!", nontrst[i].name);
		}
	}
	pres[i] = pmem;
	fatfl = 1;
	if(nerrors){
		summary();
		ZAPFILE(ACTNAME);
		ZAPFILE(TEMPNAME);
		ZAPFILE(OFILE);
		if (fdefine != NULL)
			ZAPFILE(FILED);
		exit(1);
	}
	if(pmem != &pyield[nprod])
		error("internal Yacc error: pyield %d", pmem-&pyield[nprod]);
}

int indebug = 0;
/*
 * compute an array with the first of nonterminals
 */
void cpfir(void)
{
	register int *p, **s, i, **t, ch, changes;

	zzcwp = &wsets[nnonter];
	NTLOOP(i){
		aryfil(wsets[i].ws.lset, tbitset, 0);
		t = pres[i+1];
		for(s=pres[i]; s<t; ++s){ /* initially fill the sets */
			for(p = *s; (ch = *p) > 0 ; ++p) {
				if(ch < NTBASE) {
					SETBIT(wsets[i].ws.lset, ch);
					break;
				}
				else if(!pempty[ch-NTBASE]) 
					break;
			}
		}
	}

	/* now, reflect transitivity */

	changes = 1;
	while(changes){
		changes = 0;
		NTLOOP(i){
			t = pres[i+1];
			for(s=pres[i]; s<t; ++s){
				for(p = *s; (ch = (*p-NTBASE)) >= 0; ++p) {
					changes |= setunion(wsets[i].ws.lset, wsets[ch].ws.lset);
					if(!pempty[ch])
						break;
				}
			}
		}
	}

	NTLOOP(i)
		pfirst[i] = flset(&wsets[i].ws);
	if(!indebug)
		return;
	if((foutput!=NULL)){
		NTLOOP(i) {
			fprintf(foutput,  "\n%s: ", nontrst[i].name);
			prlook(pfirst[i]);
			fprintf(foutput,  " %d\n", pempty[i]);