Backport of chained error messages from experimental branch.

1 files changed, 135 insertions, 45 deletions

diff --git a/stream/obj_parse.c b/stream/obj_parse.c
index 73b761cb..316e8ad4 100644
--- a/stream/obj_parse.c
+++ b/stream/obj_parse.c
@@ -62,6 +62,7 @@ static void parsekeyword(char **sp, char *b, char *eb)
 
 static fz_error *parsename(fz_obj **obj, char **sp)
 {
+	fz_error *error;
 	char buf[64];
 	char *s = *sp;
 	char *p = buf;
@@ -72,11 +73,15 @@ static fz_error *parsename(fz_obj **obj, char **sp)
 	*p++ = 0;
 	*sp = s;
 
-	return fz_newname(obj, buf);
+	error = fz_newname(obj, buf);
+	if (error)
+		return fz_rethrow(error, "cannot create name");
+	return fz_okay;
 }
 
 static fz_error *parsenumber(fz_obj **obj, char **sp)
 {
+	fz_error *error;
 	char buf[32];
 	char *s = *sp;
 	char *p = buf;
@@ -92,8 +97,13 @@ static fz_error *parsenumber(fz_obj **obj, char **sp)
 	*sp = s;
 
 	if (strchr(buf, '.'))
-		return fz_newreal(obj, atof(buf));
-	return fz_newint(obj, atoi(buf));
+		error = fz_newreal(obj, atof(buf));
+	else
+		error = fz_newint(obj, atoi(buf));
+
+	if (error)
+		return fz_rethrow(error, "cannot parse number");
+	return fz_okay;
 }
 
 static fz_error *parsedict(fz_obj **obj, char **sp, struct vap *v)
@@ -105,8 +115,8 @@ static fz_error *parsedict(fz_obj **obj, char **sp, struct vap *v)
 	char *s = *sp;
 
 	error = fz_newdict(&dict, 8);
-	if (error) return error;
-	*obj = dict;
+	if (error)
+		return fz_rethrow(error, "cannot create dict");
 
 	s += 2;	/* skip "<<" */
 
@@ -115,39 +125,55 @@ static fz_error *parsedict(fz_obj **obj, char **sp, struct vap *v)
 		skipwhite(&s);
 
 		/* end-of-dict marker >> */
-		if (*s == '>') {
+		if (*s == '>')
+		{
 			s ++;
-			if (*s == '>') {
+			if (*s == '>')
+			{
 				s ++;
 				break;
 			}
-			error = fz_throw("syntaxerror in parsedict");
+			error = fz_throw("malformed >> marker");
 			goto cleanup;
 		}
 
 		/* non-name as key, bail */
-		if (*s != '/') {
-			error = fz_throw("syntaxerror in parsedict");
+		if (*s != '/')
+		{
+			error = fz_throw("key is not a name");
 			goto cleanup;
 		}
 
 		error = parsename(&key, &s);
-		if (error) goto cleanup;
+		if (error)
+		{
+			error = fz_rethrow(error, "cannot parse key");
+			goto cleanup;
+		}
 
 		skipwhite(&s);
 
 		error = parseobj(&val, &s, v);
-		if (error) goto cleanup;
+		if (error)
+		{
+			error = fz_rethrow(error, "cannot parse value");
+			goto cleanup;
+		}
 
 		error = fz_dictput(dict, key, val);
-		if (error) goto cleanup;
+		if (error)
+		{
+			error = fz_rethrow(error, "cannot insert dict entry");
+			goto cleanup;
+		}
 
 		fz_dropobj(val); val = nil;
 		fz_dropobj(key); key = nil;
 	}
 
+	*obj = dict;
 	*sp = s;
-	return nil;
+	return fz_okay;
 
 cleanup:
 	if (val) fz_dropobj(val);
@@ -166,8 +192,8 @@ static fz_error *parsearray(fz_obj **obj, char **sp, struct vap *v)
 	char *s = *sp;
 
 	error = fz_newarray(&a, 8);
-	if (error) return error;
-	*obj = a;
+	if (error)
+		return fz_rethrow(error, "cannot create array");
 
 	s ++;	/* skip '[' */
 
@@ -175,26 +201,38 @@ static fz_error *parsearray(fz_obj **obj, char **sp, struct vap *v)
 	{
 		skipwhite(&s);
 
-		if (*s == ']') {
+		if (*s == ']')
+		{
 			s ++;
 			break;
 		}
 
 		error = parseobj(&o, &s, v);
-		if (error) { *obj = nil; fz_dropobj(a); return error; }
+		if (error)
+		{
+			fz_dropobj(a);
+			return fz_rethrow(error, "cannot parse item");
+		}
 
 		error = fz_arraypush(a, o);
-		if (error) { fz_dropobj(o); *obj = nil; fz_dropobj(a); return error; }
+		if (error)
+		{
+			fz_dropobj(o);
+			fz_dropobj(a);
+			return fz_rethrow(error, "cannot add item to array");
+		}
 
 		fz_dropobj(o);
 	}
 
+	*obj = a;
 	*sp = s;
-	return nil;
+	return fz_okay;
 }
 
 static fz_error *parsestring(fz_obj **obj, char **sp)
 {
+	fz_error *error;
 	char buf[512];
 	char *s = *sp;
 	char *p = buf;
@@ -236,12 +274,12 @@ static fz_error *parsestring(fz_obj **obj, char **sp)
 			}
 			else switch (*s)
 			{
-				case 'n': *p++ = '\n'; s++; break;
-				case 'r': *p++ = '\r'; s++; break;
-				case 't': *p++ = '\t'; s++; break;
-				case 'b': *p++ = '\b'; s++; break;
-				case 'f': *p++ = '\f'; s++; break;
-				default: *p++ = *s++; break;
+			case 'n': *p++ = '\n'; s++; break;
+			case 'r': *p++ = '\r'; s++; break;
+			case 't': *p++ = '\t'; s++; break;
+			case 'b': *p++ = '\b'; s++; break;
+			case 'f': *p++ = '\f'; s++; break;
+			default: *p++ = *s++; break;
 			}
 		}
 		else
@@ -252,11 +290,16 @@ static fz_error *parsestring(fz_obj **obj, char **sp)
 	}
 
 	*sp = s;
-	return fz_newstring(obj, buf, p - buf - 1);
+
+	error = fz_newstring(obj, buf, p - buf - 1);
+	if (error)
+		return fz_rethrow(error, "cannot create string");
+	return fz_okay;
 }
 
 static fz_error *parsehexstring(fz_obj **obj, char **sp)
 {
+	fz_error *error;
 	char buf[512];
 	char *s = *sp;
 	char *p = buf;
@@ -287,7 +330,10 @@ static fz_error *parsehexstring(fz_obj **obj, char **sp)
 	}
 
 	*sp = s;
-	return fz_newstring(obj, buf, p - buf);
+	error = fz_newstring(obj, buf, p - buf);
+	if (error)
+		return fz_rethrow(error, "cannot create string");
+	return fz_okay;
 }
 
 static fz_error *parseobj(fz_obj **obj, char **sp, struct vap *v)
@@ -299,7 +345,7 @@ static fz_error *parseobj(fz_obj **obj, char **sp, struct vap *v)
 	char *s = *sp;
 
 	if (*s == '\0')
-		return fz_throw("syntaxerror in parseobj: end-of-string");
+		return fz_throw("end of data");
 
 	skipwhite(&s);
 
@@ -308,6 +354,7 @@ static fz_error *parseobj(fz_obj **obj, char **sp, struct vap *v)
 	if (v != nil && *s == '%')
 	{
 		s ++;
+
 		switch (*s)
 		{
 		case 'p': error = fz_newpointer(obj, va_arg(v->ap, void*)); break;
@@ -317,61 +364,102 @@ static fz_error *parseobj(fz_obj **obj, char **sp, struct vap *v)
 		case 'f': error = fz_newreal(obj, (float)va_arg(v->ap, double)); break;
 		case 'n': error = fz_newname(obj, va_arg(v->ap, char*)); break;
 		case 'r':
-			oid = va_arg(v->ap, int);
-			gid = va_arg(v->ap, int);
-			error = fz_newindirect(obj, oid, gid);
-			break;
+			  oid = va_arg(v->ap, int);
+			  gid = va_arg(v->ap, int);
+			  error = fz_newindirect(obj, oid, gid);
+			  break;
 		case 's':
-			tmp = va_arg(v->ap, char*);
-			error = fz_newstring(obj, tmp, strlen(tmp));
-			break;
+			  tmp = va_arg(v->ap, char*);
+			  error = fz_newstring(obj, tmp, strlen(tmp));
+			  break;
 		case '#':
-			tmp = va_arg(v->ap, char*);
-			len = va_arg(v->ap, int);
-			error = fz_newstring(obj, tmp, len);
-			break;
+			  tmp = va_arg(v->ap, char*);
+			  len = va_arg(v->ap, int);
+			  error = fz_newstring(obj, tmp, len);
+			  break;
 		default:
-			error = fz_throw("unknown format specifier in packobj: '%c'", *s);
-			break;
+			  error = fz_throw("unknown format specifier in packobj: '%c'", *s);
+			  break;
 		}
+
+		if (error)
+			error = fz_rethrow(error, "cannot create object for %% format");
+
 		s ++;
 	}
 
 	else if (*s == '/')
+	{
 		error = parsename(obj, &s);
+		if (error)
+			error = fz_rethrow(error, "cannot parse name");
+	}
 
 	else if (*s == '(')
+	{
 		error = parsestring(obj, &s);
+		if (error)
+			error = fz_rethrow(error, "cannot parse string");
+	}
 
-	else if (*s == '<') {
+	else if (*s == '<')
+	{
 		if (s[1] == '<')
+		{
 			error = parsedict(obj, &s, v);
+			if (error)
+				error = fz_rethrow(error, "cannot parse dict");
+		}
 		else
+		{
 			error = parsehexstring(obj, &s);
+			if (error)
+				error = fz_rethrow(error, "cannot parse hex string");
+		}
 	}
 
 	else if (*s == '[')
+	{
 		error = parsearray(obj, &s, v);
+		if (error)
+			error = fz_rethrow(error, "cannot parse array");
+	}
 
 	else if (*s == '-' || *s == '.' || (*s >= '0' && *s <= '9'))
+	{
 		error = parsenumber(obj, &s);
+		if (error)
+			error = fz_rethrow(error, "cannot parse number");
+	}
 
 	else if (isregular(*s))
 	{
 		parsekeyword(&s, buf, buf + sizeof buf);
 
 		if (strcmp("true", buf) == 0)
+		{
 			error = fz_newbool(obj, 1);
+			if (error)
+				error = fz_rethrow(error, "cannot create bool (true)");
+		}
 		else if (strcmp("false", buf) == 0)
+		{
 			error = fz_newbool(obj, 0);
+			if (error)
+				error = fz_rethrow(error, "cannot create bool (false)");
+		}
 		else if (strcmp("null", buf) == 0)
+		{
 			error = fz_newnull(obj);
+			if (error)
+				error = fz_rethrow(error, "cannot create null object");
+		}
 		else
-			error = fz_throw("syntaxerror in parseobj: undefined keyword %s", buf);
+			error = fz_throw("undefined keyword %s", buf);
 	}
 
 	else
-		error = fz_throw("syntaxerror in parseobj");
+		error = fz_throw("syntax error: unknown byte 0x%d", *s);
 
 	*sp = s;
 	return error;
@@ -388,6 +476,8 @@ fz_packobj(fz_obj **op, char *fmt, ...)
 	va_copy(v.ap, ap);
 
 	error = parseobj(op, &fmt, &v);
+	if (error)
+		error = fz_rethrow(error, "cannot parse object");
 
 	va_end(ap);