[PATCH 2/2] fixup! stdio: stub out basprintf and friends when built for PBL

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

vsprintf: fix false positive about use of uninitialized variable

barebox vasprintf only writes to its strp argument, when a buffer could
be allocated. If out of memory (or in PBL without malloc), -1 is
returned after vsnprintf determines the length.

GCC 13.1.1 seems not able to track use of strp across vsnprintf
correctly though resulting in a bogus warning:

  ./lib/vsprintf.c: In function 'bvasprintf':
  ./lib/vsprintf.c:961:16: warning: 'p' may be used uninitialized
                           [-Wmaybe-uninitialized]
    961 |         return p;
        |                ^

Fix this by adding an explicit early exit for the PBL case.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 lib/vsprintf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index e421a4352a12..edc3f4aa4fe0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -933,6 +933,10 @@ int vasprintf(char **strp, const char *fmt, va_list ap)
 	va_list aq;
 	char *p;
 
+	/* Silence -Wmaybe-uninitialized false positive */
+	if (IN_PBL)
+		return -1;
+
 	va_copy(aq, ap);
 	len = vsnprintf(NULL, 0, fmt, aq);
 	va_end(aq);
-- 
2.39.5