[PATCH] vsprintf: Fix warnings about missing gnu_printf attribute in vsprintf.o

[Petr Mladek]

The following warning is produced by: make W=1 lib/vsprintf.o

lib/vsprintf.c:1770:1: error: multiple storage classes in declaration specifiers
 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
 ^~~~~~
lib/vsprintf.c:1770:14: warning: no previous prototype for ‘va_format’ [-Wmissing-prototypes]
 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
              ^~~~~~~~~

More similar warnings are printed after fixing the 1st one:

lib/vsprintf.c: In function ‘pointer’:
lib/vsprintf.c:2522:3: warning: function ‘pointer’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
   return va_format(buf, end, ptr, spec, fmt);
   ^~~~~~
lib/vsprintf.c: In function ‘vbin_printf’:
lib/vsprintf.c:3213:12: warning: function ‘vbin_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
            spec);
            ^~~~
lib/vsprintf.c: In function ‘bstr_printf’:
lib/vsprintf.c:3398:5: warning: function ‘bstr_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
     str = pointer(fmt, str, end, get_arg(void *), spec);
     ^~~

Add the proposed annotation.

Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
 include/linux/string.h | 3 +++
 lib/vsprintf.c         | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h
index b6572aeca2f5..e37eaecb7906 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -196,8 +196,11 @@ int __sysfs_match_string(const char * const *array, size_t n, const char *s);
 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 
 #ifdef CONFIG_BINARY_PRINTF
+__printf(3, 0)
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
+__printf(3, 0)
 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
+__printf(3, 4)
 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 #endif
 
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3b8129dd374c..981c71da5e3d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1672,6 +1672,7 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 	return buf;
 }
 
+__printf(5, 0)
 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
 		       struct printf_spec spec, const char *fmt)
 {
@@ -2498,6 +2499,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
  * @precision: precision of a number
  * @qualifier: qualifier of a number (long, size_t, ...)
  */
+__printf(1, 0)
 static noinline_for_stack
 int format_decode(const char *fmt, struct printf_spec *spec)
 {
-- 
2.26.2