From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Date: Fri, 11 Apr 2025 09:00:51 +0000 (+0200)
Subject: tools/nolibc: add snprintf() and friends
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ed45d24cf23521b12271d95f8e87b839e79dd65e;p=users%2Fhch%2Fmisc.git

tools/nolibc: add snprintf() and friends

Add more of the printf() functions.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index b17b473bd875..46bd90f96d65 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -389,6 +389,61 @@ int dprintf(int fd, const char *fmt, ...)
 	va_start(args, fmt);
 	ret = vdprintf(fd, fmt, args);
 	va_end(args);
+
+	return ret;
+}
+
+static int __nolibc_sprintf_cb(intptr_t _state, const char *buf, size_t size)
+{
+	char **state = (char **)_state;
+
+	memcpy(*state, buf, size);
+	*state += size;
+	return 0;
+}
+
+static __attribute__((unused, format(printf, 3, 0)))
+int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+{
+	char *state = buf;
+	int ret;
+
+	ret = __nolibc_printf(__nolibc_sprintf_cb, (intptr_t)&state, size, fmt, args);
+	if (ret < 0)
+		return ret;
+	buf[(size_t)ret < size ? (size_t)ret : size - 1] = '\0';
+	return ret;
+}
+
+static __attribute__((unused, format(printf, 3, 4)))
+int snprintf(char *buf, size_t size, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vsnprintf(buf, size, fmt, args);
+	va_end(args);
+
+	return ret;
+}
+
+static __attribute__((unused, format(printf, 2, 0)))
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+	return vsnprintf(buf, SIZE_MAX, fmt, args);
+}
+
+static __attribute__((unused, format(printf, 2, 3)))
+int sprintf(char *buf, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vsprintf(buf, fmt, args);
+	va_end(args);
+
 	return ret;
 }