From e37302c4b99f147f1fd85ca27a2dbd2aa7a4eb41 Mon Sep 17 00:00:00 2001
From: wkj <devnull@localhost>
Date: Wed, 21 Apr 2004 01:22:09 +0000
Subject: Plan 9 lex (to be installed as lex.9, if at all).

---
 src/cmd/lex/sub1.c | 591 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 591 insertions(+)
 create mode 100644 src/cmd/lex/sub1.c

(limited to 'src/cmd/lex/sub1.c')

diff --git a/src/cmd/lex/sub1.c b/src/cmd/lex/sub1.c
new file mode 100644
index 00000000..cb393a46
--- /dev/null
+++ b/src/cmd/lex/sub1.c
@@ -0,0 +1,591 @@
+# include "ldefs.h"
+uchar *
+getl(uchar *p)	/* return next line of input, throw away trailing '\n' */
+	/* returns 0 if eof is had immediately */
+{
+	int c;
+	uchar *s, *t;
+
+	t = s = p;
+	while(((c = gch()) != 0) && c != '\n')
+		*t++ = c;
+	*t = 0;
+	if(c == 0 && s == t) return((uchar *)0);
+	prev = '\n';
+	pres = '\n';
+	return(s);
+}
+
+void
+printerr(char *type, char *fmt, va_list argl)
+{
+	char buf[1024];
+
+	if(!eof)fprint(errorf,"%d: ",yyline);
+	fprint(errorf,"(%s) ", type);
+	vseprint(buf, buf+sizeof(buf), fmt, argl);
+	fprint(errorf, "%s\n", buf);
+}
+
+
+void
+error(char *s,...)
+{
+	va_list argl;
+
+	va_start(argl, s);
+	printerr("Error", s, argl);
+	va_end(argl);
+# ifdef DEBUG
+	if(debug && sect != ENDSECTION) {
+		sect1dump();
+		sect2dump();
+	}
+# endif
+	if(
+# ifdef DEBUG
+		debug ||
+# endif
+		report == 1) statistics();
+	exits("error");	/* error return code */
+}
+
+void
+warning(char *s,...)
+{
+	va_list argl;
+
+	va_start(argl, s);
+	printerr("Warning", s, argl);
+	va_end(argl);
+	Bflush(&fout);
+}
+
+void
+lgate(void)
+{
+	int fd;
+
+	if (lgatflg) return;
+	lgatflg=1;
+	if(foutopen == 0){
+		fd = create("lex.yy.c", OWRITE, 0666);
+		if(fd < 0)
+			error("Can't open lex.yy.c");
+		Binit(&fout, fd, OWRITE);
+		foutopen = 1;
+		}
+	phead1();
+}
+
+void
+cclinter(int sw)
+{
+		/* sw = 1 ==> ccl */
+	int i, j, k;
+	int m;
+	if(!sw){		/* is NCCL */
+		for(i=1;i<NCH;i++)
+			symbol[i] ^= 1;			/* reverse value */
+	}
+	for(i=1;i<NCH;i++)
+		if(symbol[i]) break;
+	if(i >= NCH) return;
+	i = cindex[i];
+	/* see if ccl is already in our table */
+	j = 0;
+	if(i){
+		for(j=1;j<NCH;j++){
+			if((symbol[j] && cindex[j] != i) ||
+			   (!symbol[j] && cindex[j] == i)) break;
+		}
+	}
+	if(j >= NCH) return;		/* already in */
+	m = 0;
+	k = 0;
+	for(i=1;i<NCH;i++)
+		if(symbol[i]){
+			if(!cindex[i]){
+				cindex[i] = ccount;
+				symbol[i] = 0;
+				m = 1;
+			} else k = 1;
+		}
+			/* m == 1 implies last value of ccount has been used */
+	if(m)ccount++;
+	if(k == 0) return;	/* is now in as ccount wholly */
+	/* intersection must be computed */
+	for(i=1;i<NCH;i++){
+		if(symbol[i]){
+			m = 0;
+			j = cindex[i];	/* will be non-zero */
+			for(k=1;k<NCH;k++){
+				if(cindex[k] == j){
+					if(symbol[k]) symbol[k] = 0;
+					else {
+						cindex[k] = ccount;
+						m = 1;
+					}
+				}
+			}
+			if(m)ccount++;
+		}
+	}
+}
+
+int
+usescape(int c)
+{
+	int d;
+	switch(c){
+	case 'n': c = '\n'; break;
+	case 'r': c = '\r'; break;
+	case 't': c = '\t'; break;
+	case 'b': c = '\b'; break;
+	case 'f': c = 014; break;		/* form feed for ascii */
+	case '0': case '1': case '2': case '3':
+	case '4': case '5': case '6': case '7':
+		c -= '0';
+		while('0' <= (d=gch()) && d <= '7'){
+			c = c * 8 + (d-'0');
+			if(!('0' <= peek && peek <= '7')) break;
+			}
+		break;
+	}
+	return(c);
+}
+
+int
+lookup(uchar *s, uchar **t)
+{
+	int i;
+	i = 0;
+	while(*t){
+		if(strcmp((char *)s, *(char **)t) == 0)
+			return(i);
+		i++;
+		t++;
+	}
+	return(-1);
+}
+
+int
+cpyact(void)
+{ /* copy C action to the next ; or closing } */
+	int brac, c, mth;
+	int savline, sw;
+
+	brac = 0;
+	sw = TRUE;
+	savline = 0;
+
+while(!eof){
+	c = gch();
+swt:
+	switch( c ){
+
+case '|':	if(brac == 0 && sw == TRUE){
+			if(peek == '|')gch();		/* eat up an extra '|' */
+			return(0);
+		}
+		break;
+
+case ';':
+		if( brac == 0 ){
+			Bputc(&fout, c);
+			Bputc(&fout, '\n');
+			return(1);
+		}
+		break;
+
+case '{':
+		brac++;
+		savline=yyline;
+		break;
+
+case '}':
+		brac--;
+		if( brac == 0 ){
+			Bputc(&fout, c);
+			Bputc(&fout, '\n');
+			return(1);
+		}
+		break;
+
+case '/':	/* look for comments */
+		Bputc(&fout, c);
+		c = gch();
+		if( c != '*' ) goto swt;
+
+		/* it really is a comment */
+
+		Bputc(&fout, c);
+		savline=yyline;
+		while( c=gch() ){
+			if( c=='*' ){
+				Bputc(&fout, c);
+				if( (c=gch()) == '/' ) goto loop;
+			}
+			Bputc(&fout, c);
+		}
+		yyline=savline;
+		error( "EOF inside comment" );
+
+case '\'':	/* character constant */
+		mth = '\'';
+		goto string;
+
+case '"':	/* character string */
+		mth = '"';
+
+	string:
+
+		Bputc(&fout, c);
+		while( c=gch() ){
+			if( c=='\\' ){
+				Bputc(&fout, c);
+				c=gch();
+			}
+			else if( c==mth ) goto loop;
+			Bputc(&fout, c);
+			if (c == '\n') {
+				yyline--;
+				error( "Non-terminated string or character constant");
+			}
+		}
+		error( "EOF in string or character constant" );
+
+case '\0':
+		yyline = savline;
+		error("Action does not terminate");
+default:
+		break;		/* usual character */
+		}
+loop:
+	if(c != ' ' && c != '\t' && c != '\n') sw = FALSE;
+	Bputc(&fout, c);
+	}
+	error("Premature EOF");
+	return(0);
+}
+
+int
+gch(void){
+	int c;
+	prev = pres;
+	c = pres = peek;
+	peek = pushptr > pushc ? *--pushptr : Bgetc(fin);
+	if(peek == Beof && sargc > 1){
+		Bterm(fin);
+		fin = Bopen(sargv[fptr++],OREAD);
+		if(fin == 0)
+			error("Cannot open file %s",sargv[fptr-1]);
+		peek = Bgetc(fin);
+		sargc--;
+		sargv++;
+	}
+	if(c == Beof) {
+		eof = TRUE;
+		Bterm(fin);
+		return(0);
+	}
+	if(c == '\n')yyline++;
+	return(c);
+}
+
+int
+mn2(int a, int d, int c)
+{
+	name[tptr] = a;
+	left[tptr] = d;
+	right[tptr] = c;
+	parent[tptr] = 0;
+	nullstr[tptr] = 0;
+	switch(a){
+	case RSTR:
+		parent[d] = tptr;
+		break;
+	case BAR:
+	case RNEWE:
+		if(nullstr[d] || nullstr[c]) nullstr[tptr] = TRUE;
+		parent[d] = parent[c] = tptr;
+		break;
+	case RCAT:
+	case DIV:
+		if(nullstr[d] && nullstr[c])nullstr[tptr] = TRUE;
+		parent[d] = parent[c] = tptr;
+		break;
+	case RSCON:
+		parent[d] = tptr;
+		nullstr[tptr] = nullstr[d];
+		break;
+# ifdef DEBUG
+	default:
+		warning("bad switch mn2 %d %d",a,d);
+		break;
+# endif
+		}
+	if(tptr > treesize)
+		error("Parse tree too big %s",(treesize == TREESIZE?"\nTry using %e num":""));
+	return(tptr++);
+}
+
+int
+mn1(int a, int d)
+{
+	name[tptr] = a;
+	left[tptr] = d;
+	parent[tptr] = 0;
+	nullstr[tptr] = 0;
+	switch(a){
+	case RCCL:
+	case RNCCL:
+		if(strlen((char *)d) == 0) nullstr[tptr] = TRUE;
+		break;
+	case STAR:
+	case QUEST:
+		nullstr[tptr] = TRUE;
+		parent[d] = tptr;
+		break;
+	case PLUS:
+	case CARAT:
+		nullstr[tptr] = nullstr[d];
+		parent[d] = tptr;
+		break;
+	case S2FINAL:
+		nullstr[tptr] = TRUE;
+		break;
+# ifdef DEBUG
+	case FINAL:
+	case S1FINAL:
+		break;
+	default:
+		warning("bad switch mn1 %d %d",a,d);
+		break;
+# endif
+	}
+	if(tptr > treesize)
+		error("Parse tree too big %s",(treesize == TREESIZE?"\nTry using %e num":""));
+	return(tptr++);
+}
+
+int
+mn0(int a)
+{
+	name[tptr] = a;
+	parent[tptr] = 0;
+	nullstr[tptr] = 0;
+	if(a >= NCH) switch(a){
+	case RNULLS: nullstr[tptr] = TRUE; break;
+# ifdef DEBUG
+	default:
+		warning("bad switch mn0 %d",a);
+		break;
+# endif
+	}
+	if(tptr > treesize)
+		error("Parse tree too big %s",(treesize == TREESIZE?"\nTry using %e num":""));
+	return(tptr++);
+}
+
+void
+munputc(int p)
+{
+	*pushptr++ = peek;		/* watch out for this */
+	peek = p;
+	if(pushptr >= pushc+TOKENSIZE)
+		error("Too many characters pushed");
+}
+
+void
+munputs(uchar *p)
+{
+	int i,j;
+	*pushptr++ = peek;
+	peek = p[0];
+	i = strlen((char*)p);
+	for(j = i-1; j>=1; j--)
+		*pushptr++ = p[j];
+	if(pushptr >= pushc+TOKENSIZE)
+		error("Too many characters pushed");
+}
+
+int
+dupl(int n)
+{
+	/* duplicate the subtree whose root is n, return ptr to it */
+	int i;
+
+	i = name[n];
+	if(i < NCH) return(mn0(i));
+	switch(i){
+	case RNULLS:
+		return(mn0(i));
+	case RCCL: case RNCCL: case FINAL: case S1FINAL: case S2FINAL:
+		return(mn1(i,left[n]));
+	case STAR: case QUEST: case PLUS: case CARAT:
+		return(mn1(i,dupl(left[n])));
+	case RSTR: case RSCON:
+		return(mn2(i,dupl(left[n]),right[n]));
+	case BAR: case RNEWE: case RCAT: case DIV:
+		return(mn2(i,dupl(left[n]),dupl(right[n])));
+# ifdef DEBUG
+	default:
+		warning("bad switch dupl %d",n);
+# endif
+	}
+	return(0);
+}
+
+# ifdef DEBUG
+void
+allprint(int c)
+{
+	switch(c){
+		case 014:
+			print("\\f");
+			charc++;
+			break;
+		case '\n':
+			print("\\n");
+			charc++;
+			break;
+		case '\t':
+			print("\\t");
+			charc++;
+			break;
+		case '\b':
+			print("\\b");
+			charc++;
+			break;
+		case ' ':
+			print("\\\bb");
+			break;
+		default:
+			if(!isprint(c)){
+				print("\\%-3o",c);
+				charc += 3;
+			} else 
+				print("%c", c);
+			break;
+	}
+	charc++;
+}
+
+void
+strpt(uchar *s)
+{
+	charc = 0;
+	while(*s){
+		allprint(*s++);
+		if(charc > LINESIZE){
+			charc = 0;
+			print("\n\t");
+		}
+	}
+}
+
+void
+sect1dump(void)
+{
+	int i;
+
+	print("Sect 1:\n");
+	if(def[0]){
+		print("str	trans\n");
+		i = -1;
+		while(def[++i])
+			print("%s\t%s\n",def[i],subs[i]);
+	}
+	if(sname[0]){
+		print("start names\n");
+		i = -1;
+		while(sname[++i])
+			print("%s\n",sname[i]);
+	}
+}
+
+void
+sect2dump(void)
+{
+	print("Sect 2:\n");
+	treedump();
+}
+
+void
+treedump(void)
+{
+	int t;
+	uchar *p;
+	print("treedump %d nodes:\n",tptr);
+	for(t=0;t<tptr;t++){
+		print("%4d ",t);
+		parent[t] ? print("p=%4d",parent[t]) : print("      ");
+		print("  ");
+		if(name[t] < NCH)
+				allprint(name[t]);
+		else switch(name[t]){
+			case RSTR:
+				print("%d ",left[t]);
+				allprint(right[t]);
+				break;
+			case RCCL:
+				print("ccl ");
+				strpt(left[t]);
+				break;
+			case RNCCL:
+				print("nccl ");
+				strpt(left[t]);
+				break;
+			case DIV:
+				print("/ %d %d",left[t],right[t]);
+				break;
+			case BAR:
+				print("| %d %d",left[t],right[t]);
+				break;
+			case RCAT:
+				print("cat %d %d",left[t],right[t]);
+				break;
+			case PLUS:
+				print("+ %d",left[t]);
+				break;
+			case STAR:
+				print("* %d",left[t]);
+				break;
+			case CARAT:
+				print("^ %d",left[t]);
+				break;
+			case QUEST:
+				print("? %d",left[t]);
+				break;
+			case RNULLS:
+				print("nullstring");
+				break;
+			case FINAL:
+				print("final %d",left[t]);
+				break;
+			case S1FINAL:
+				print("s1final %d",left[t]);	
+				break;
+			case S2FINAL:
+				print("s2final %d",left[t]);
+				break;
+			case RNEWE:
+				print("new %d %d",left[t],right[t]);
+				break;
+			case RSCON:
+				p = (uchar *)right[t];
+				print("start %s",sname[*p++-1]);
+				while(*p)
+					print(", %s",sname[*p++-1]);
+				print(" %d",left[t]);
+				break;
+			default:
+				print("unknown %d %d %d",name[t],left[t],right[t]);
+				break;
+		}
+		if(nullstr[t])print("\t(null poss.)");
+		print("\n");
+	}
+}
+# endif
-- 
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