shithub: libmujs

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Print error message with line number on lexical errors.

--- a/js-lex.c

+++ b/js-lex.c

@@ -118,6 +118,17 @@

 #define NEXTPEEK() (NEXT(), PEEK())

 #define LOOK(x) (PEEK() == x ? (NEXT(), 1) : 0)

+js_Token js_syntaxerror(js_State *J, const char *fmt, ...)

+{

+	va_list ap;

+	fprintf(stderr, "syntax error: line %d: ", J->yyline);

+	va_start(ap, fmt);

+	vfprintf(stderr, fmt, ap);

+	va_end(ap);

+	fprintf(stderr, "\n");

+	return JS_ERROR;

+}

+

 static void textinit(js_State *J)

 {

 	if (!J->yytext) {

@@ -260,13 +271,13 @@

 	if ((*sp)[0] == '0' && ((*sp)[1] == 'x' || (*sp)[1] == 'X')) {

 		*sp += 2;

 		if (!ishex(PEEK()))

-			return JS_ERROR;

+			return js_syntaxerror(J, "0x not followed by hexademical digit");

 		J->yynumber = lexhex(sp);

 		return JS_NUMBER;

 	}

-	if ((*sp)[0] == '0' && (*sp)[1] == '0')

-		return JS_ERROR;

+	if ((*sp)[0] == '0' && isdec((*sp)[1]))

+		return js_syntaxerror(J, "number with leading zero");

 	n = lexinteger(sp);

 	if (LOOK('.'))

@@ -274,7 +285,7 @@

 	n *= pow(10, lexexponent(sp));

 	if (isidentifierstart(PEEK()))

-		return JS_ERROR;

+		return js_syntaxerror(J, "number with letter suffix");

 	J->yynumber = n;

 	return JS_NUMBER;

@@ -318,7 +329,7 @@

 	while (c != q) {

 		if (c == 0 || isnewline(c))

-			return JS_ERROR;

+			return js_syntaxerror(J, "string not terminated");

 		if (c == '\\')

 			c = lexescape(sp);

@@ -363,12 +374,12 @@

 	c = GET();

 	while (c != '/') {

 		if (c == 0 || isnewline(c)) {

-			return JS_ERROR;

+			return js_syntaxerror(J, "regular expression not terminated");

 		} else if (c == '\\') {

 			textpush(J, c);

 			c = GET();

 			if (c == 0 || isnewline(c))

-				return JS_ERROR;

+				return js_syntaxerror(J, "regular expression not terminated");

 			textpush(J, c);

 			c = GET();

 		} else {

@@ -387,12 +398,12 @@

 		if (c == 'g') J->yyflags.g ++;

 		else if (c == 'i') J->yyflags.i ++;

 		else if (c == 'm') J->yyflags.m ++;

-		else return JS_ERROR;

+		else return js_syntaxerror(J, "illegal flag in regular expression: %c", c);

 		c = NEXTPEEK();

 	}

 	if (J->yyflags.g > 1 || J->yyflags.i > 1 || J->yyflags.m > 1)

-		return JS_ERROR;

+		return js_syntaxerror(J, "duplicated flag in regular expression");

 	return JS_REGEXP;

 }

@@ -404,8 +415,13 @@

 		while (iswhite(c))

 			c = GET();

-		if (isnewline(c))

+		if (isnewline(c)) {

+			/* consume CR LF as one unit */

+			if (c == '\r' && PEEK() == '\n')

+				NEXT();

+			J->yyline++;

 			return JS_NEWLINE;

+		}

 		if (c == '/') {

 			if (LOOK('/')) {

@@ -412,7 +428,7 @@

 				lexlinecomment(sp);

 			} else if (LOOK('*')) {

 				if (lexcomment(sp))

-					return JS_ERROR;

+					return js_syntaxerror(J, "multi-line comment not terminated");

 			} else if (isregexpcontext(J->lasttoken)) {

 				return lexregexp(J, sp);

 			} else if (LOOK('=')) {

@@ -564,4 +580,10 @@

 	js_Token t = js_leximp(J, sp);

 	J->lasttoken = t;

 	return t;

+}

+

+void js_initlex(js_State *J)

+{

+	J->yyline = 1;

+	J->lasttoken = JS_ERROR;

 }

--- a/js-load.c

+++ b/js-load.c

@@ -4,6 +4,8 @@

 {

 	js_Token t;

+	js_initlex(J);

+

 	do {

 		t = js_lex(J, &source);

--- a/js.h

+++ b/js.h

@@ -156,10 +156,13 @@

 	size_t yylen, yycap;

 	double yynumber;

 	struct { int g, i, m; } yyflags;

+	int yyline;

 	js_Token lasttoken;

 };

+void js_initlex(js_State *J);

 js_Token js_lex(js_State *J, const char **sp);

+js_Token js_syntaxerror(js_State *J, const char *fmt, ...);

 const char *js_tokentostring(js_Token t);

 #endif