Re: [PATCH 1/5] strbuf API additions and enhancements.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Edgar Toernig schrieb:
Pierre Habouzit wrote:
+void strbuf_addvf(struct strbuf *sb, const char *fmt, va_list ap)
+{
+	int len;
+
+	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
+	if (len < 0) {
+		len = 0;
+	}
+	if (len > strbuf_avail(sb)) {
+		strbuf_grow(sb, len);
+		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
+		if (len > strbuf_avail(sb)) {
+			die("this should not happen, your snprintf is broken");
+		}
+	}
+	strbuf_setlen(sb, sb->len + len);
+}

The second vsnprintf won't work as the first one consumed all args
from va_list ap.  You need to va_copy the ap.

Your analysis is not correct. The second vsnprintf receives the same argument pointer as the first, and, hence, consumes the same set of arguments.

You have to use va_copy in a variadic function, ie. if you are using va_start+va_end in the same function, but not in a function with a fixed list of arguments like this one.

-- Hannes
-
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Kernel Development]     [Gcc Help]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [V4L]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Fedora Users]

  Powered by Linux