From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Date: Fri, 11 Apr 2025 09:00:52 +0000 (+0200)
Subject: selftests/nolibc: use snprintf() for printf tests
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c685cd6db59cc4557c93538677a8bdaa05f49fbc;p=users%2Fhch%2Fmisc.git

selftests/nolibc: use snprintf() for printf tests

With a proper snprintf() implementation in place, the ugly pipe usage is
not necessary anymore.

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

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 64f88b492029..1874199b2cf6 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1299,27 +1299,14 @@ int run_stdlib(int min, int max)
 
 static int expect_vfprintf(int llen, int c, const char *expected, const char *fmt, ...)
 {
-	int ret, pipefd[2];
-	ssize_t w, r;
 	char buf[100];
-	FILE *memfile;
 	va_list args;
+	ssize_t w;
+	int ret;
 
-	ret = pipe(pipefd);
-	if (ret == -1) {
-		llen += printf(" pipe() != %s", strerror(errno));
-		result(llen, FAIL);
-		return 1;
-	}
-
-	memfile = fdopen(pipefd[1], "w");
-	if (!memfile) {
-		result(llen, FAIL);
-		return 1;
-	}
 
 	va_start(args, fmt);
-	w = vfprintf(memfile, fmt, args);
+	w = vsnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 
 	if (w != c) {
@@ -1328,17 +1315,6 @@ static int expect_vfprintf(int llen, int c, const char *expected, const char *fm
 		return 1;
 	}
 
-	fclose(memfile);
-
-	r = read(pipefd[0], buf, sizeof(buf) - 1);
-
-	if (r != w) {
-		llen += printf(" written(%d) != read(%d)", (int)w, (int)r);
-		result(llen, FAIL);
-		return 1;
-	}
-
-	buf[r] = '\0';
 	llen += printf(" \"%s\" = \"%s\"", expected, buf);
 	ret = strncmp(expected, buf, c);