From: Thomas Weißschuh linux@weissschuh.net

[ Upstream commit f1a58f61d88642ae1e6e97e9d72d73bc70a93cb8 ]

Clang on higher optimization levels detects that NULL is passed to printf("%s") and warns about it. While printf() from nolibc gracefully handles that NULL, it is undefined behavior as per POSIX, so the warning is reasonable. Avoid the warning by transforming NULL into a non-NULL placeholder.

Reviewed-by: Shuah Khan skhan@linuxfoundation.org Acked-by: Willy Tarreau w@1wt.eu Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-8-c20f2f5fc7c2@weissschuh.... Signed-off-by: Thomas Weißschuh linux@weissschuh.net Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/nolibc/nolibc-test.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 093d0512f4c57..8cbb51dca0cd6 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -542,7 +542,7 @@ int expect_strzr(const char *expr, int llen) { int ret = 0;

- llen += printf(" = <%s> ", expr); + llen += printf(" = <%s> ", expr ? expr : "(null)"); if (expr) { ret = 1; result(llen, FAIL); @@ -561,7 +561,7 @@ int expect_strnz(const char *expr, int llen) { int ret = 0;

- llen += printf(" = <%s> ", expr); + llen += printf(" = <%s> ", expr ? expr : "(null)"); if (!expr) { ret = 1; result(llen, FAIL);