#include <u.h>#include <libc.h>#include <stdio.h>#include "cpp.h" #define	OUTS	16384char	outbuf[OUTS];char	*outp = outbuf;Source	*cursource;int	nerrs;struct	token nltoken = { NL, 0, 0, 0, 1, (uchar*)"\n" };char	*curtime;int	incdepth;int	ifdepth;int	ifsatisfied[NIF];int	skipping; intmain(int argc, char **argv){	Tokenrow tr;	long t;	char ebuf[BUFSIZ]; 	setbuf(stderr, ebuf);	t = time(NULL);	curtime = ctime(t);	maketokenrow(3, &tr);	expandlex();	setup(argc, argv);	iniths();	genline();	process(&tr);	flushout();	fflush(stderr);	exits(nerrs? "errors" : 0);} voidprocess(Tokenrow *trp){	int anymacros = 0; 	for (;;) {		if (trp->tp >= trp->lp) {			trp->tp = trp->lp = trp->bp;			outp = outbuf;			anymacros |= gettokens(trp, 1);			trp->tp = trp->bp;		}		if (trp->tp->type == END) {			if (--incdepth>=0) {				if (cursource->ifdepth)					error(ERROR,					 "Unterminated conditional in #include");				unsetsource();				cursource->line += cursource->lineinc;				trp->tp = trp->lp;				genline();				continue;			}			if (ifdepth)				error(ERROR, "Unterminated #if/#ifdef/#ifndef");			break;		}		if (trp->tp->type==SHARP) {			trp->tp += 1;			control(trp);		} else if (!skipping && anymacros)			expandrow(trp, NULL);		if (skipping)			setempty(trp);		puttokens(trp);		anymacros = 0;		cursource->line += cursource->lineinc;		if (cursource->lineinc>1) {			genline();		}	}}	voidcontrol(Tokenrow *trp){	Nlist *np;	Token *tp;	Dir *d;	Once n; 	tp = trp->tp;	if (tp->type!=NAME) {		if (tp->type==NUMBER)			goto kline;		if (tp->type != NL)			error(ERROR, "Unidentifiable control line");		return;			/* else empty line */	}	if ((np = lookup(tp, 0))==NULL || (np->flag&ISKW)==0 && !skipping) {		error(WARNING, "Unknown preprocessor control %t", tp);		return;	}	if (skipping) {		if ((np->flag&ISKW)==0)			return;		switch (np->val) {		case KENDIF:			if (--ifdepth<skipping)				skipping = 0;			--cursource->ifdepth;			setempty(trp);			return; 		case KIFDEF:		case KIFNDEF:		case KIF:			if (++ifdepth >= NIF)				error(FATAL, "#if too deeply nested");			++cursource->ifdepth;			return; 		case KELIF:		case KELSE:			if (ifdepth<=skipping)				break;			return; 		default:			return;		}	}	switch (np->val) {	case KDEFINE:		dodefine(trp);		break; 	case KUNDEF:		tp += 1;		if (tp->type!=NAME || trp->lp - trp->bp != 4) {			error(ERROR, "Syntax error in #undef");			break;		}		if ((np = lookup(tp, 0))) {			if (np->flag&ISUNCHANGE) {				error(ERROR, "#defined token %t can't be undefined", tp);				return;			}			np->flag &= ~ISDEFINED;		}		break; 	case KPRAGMA:		tp += 1;		if (tp->type!=NAME || tp->len < 4 || memcmp(tp->t, "once", 4) != 0)			return;		if (nblocked >= NONCE)			error(FATAL, "#pragma once list max length exceeded");		d = dirfstat(cursource->fd);		if (d == nil)			error(FATAL, "Out of memory from dirfstat");		n.qid = d->qid;		n.type = d->type;		n.dev = d->dev;		incblocked[nblocked++] = n;		free(d);		break; 	case KIFDEF:	case KIFNDEF:	case KIF:		if (++ifdepth >= NIF)			error(FATAL, "#if too deeply nested");		++cursource->ifdepth;		ifsatisfied[ifdepth] = 0;		if (eval(trp, np->val))			ifsatisfied[ifdepth] = 1;		else			skipping = ifdepth;		break; 	case KELIF:		if (ifdepth==0) {			error(ERROR, "#elif with no #if");			return;		}		if (ifsatisfied[ifdepth]==2)			error(ERROR, "#elif after #else");		if (eval(trp, np->val)) {			if (ifsatisfied[ifdepth])				skipping = ifdepth;			else {				skipping = 0;				ifsatisfied[ifdepth] = 1;			}		} else			skipping = ifdepth;		break; 	case KELSE:		if (ifdepth==0 || cursource->ifdepth==0) {			error(ERROR, "#else with no #if");			return;		}		if (ifsatisfied[ifdepth]==2)			error(ERROR, "#else after #else");		if (trp->lp - trp->bp != 3)			error(ERROR, "Syntax error in #else");		skipping = ifsatisfied[ifdepth]? ifdepth: 0;		ifsatisfied[ifdepth] = 2;		break; 	case KENDIF:		if (ifdepth==0 || cursource->ifdepth==0) {			error(ERROR, "#endif with no #if");			return;		}		--ifdepth;		--cursource->ifdepth;		if (trp->lp - trp->bp != 3)			error(WARNING, "Syntax error in #endif");		break; 	case KERROR:		trp->tp = tp+1;		error(ERROR, "#error directive: %r", trp);		break; 	case KWARNING:		trp->tp = tp+1;		error(WARNING, "#warning directive: %r", trp);		break; 	case KLINE:		trp->tp = tp+1;		expandrow(trp, "<line>");		tp = trp->bp+2;	kline:		if (tp+1>=trp->lp || tp->type!=NUMBER || tp+3<trp->lp		 || (tp+3==trp->lp && ((tp+1)->type!=STRING)||*(tp+1)->t=='L')){			error(ERROR, "Syntax error in #line");			return;		}		cursource->line = atol((char*)tp->t)-1;		if (cursource->line<0 || cursource->line>=32768)			error(WARNING, "#line specifies number out of range");		tp = tp+1;		if (tp+1<trp->lp)			cursource->filename=(char*)newstring(tp->t+1,tp->len-2,0);		return; 	case KDEFINED:		error(ERROR, "Bad syntax for control line");		break; 	case KINCLUDE:		doinclude(trp);		trp->lp = trp->bp;		return; 	case KEVAL:		eval(trp, np->val);		break; 	default:		error(ERROR, "Preprocessor control `%t' not yet implemented", tp);		break;	}	setempty(trp);	return;} void *dorealloc(void *ptr, int size){	void *p = realloc(ptr, size); 	if (p==NULL)		error(FATAL, "Out of memory from realloc");	return p;} void *domalloc(int size){	void *p = malloc(size); 	if (p==NULL)		error(FATAL, "Out of memory from malloc");	return p;} voiddofree(void *p){	free(p);} voiderror(enum errtype type, char *string, ...){	va_list ap;	char *cp, *ep;	Token *tp;	Tokenrow *trp;	Source *s;	int i;	void *p; 	fprintf(stderr, "cpp: ");	for (s=cursource; s; s=s->next)		if (*s->filename)			fprintf(stderr, "%s:%d ", s->filename, s->line);	va_start(ap, string);	for (ep=string; *ep; ep++) {		if (*ep=='%') {			switch (*++ep) { 			case 's':				cp = va_arg(ap, char *);				fprintf(stderr, "%s", cp);				break;			case 'd':				i = va_arg(ap, int);				fprintf(stderr, "%d", i);				break;			case 'p':				p = va_arg(ap, void *);				fprintf(stderr, "%p", p);				break;			case 't':				tp = va_arg(ap, Token *);				fprintf(stderr, "%.*s", tp->len, tp->t);				break; 			case 'r':				trp = va_arg(ap, Tokenrow *);				for (tp=trp->tp; tp<trp->lp&&tp->type!=NL; tp++) {					if (tp>trp->tp && tp->wslen)						fputc(' ', stderr);					fprintf(stderr, "%.*s", tp->len, tp->t);				}				break; 			default:				fputc(*ep, stderr);				break;			}		} else			fputc(*ep, stderr);	}	va_end(ap);	fputc('\n', stderr);	if (type==FATAL)		exits("error");	if (type!=WARNING)		nerrs = 1;	fflush(stderr);}