Enable type-checking of arguments passed to printf() et al.

This patch modifies the declarations of the functions printf() et al.
and adds the right GCC attribute to request the compiler to check
the type of the arguments passed to these functions against the given
format string. This will ensure that the compiler outputs warning
messages like the following whenever it detects an inconsistency:

 file.c:42: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long int’

It also fixes the type mismatch inconsistencies that it revealed
across the code base.

NOTE: THIS PATCH MAY FORCE PLATFORM PORTS OR SP/SPDS THAT USE THE
PRINTF FAMILY OF FUNCTIONS TO FIX ANY TYPE MISMATCH INCONSISTENCIES.

Change-Id: If36bb54ec7d6dd2cb4791d89b02a24ac13fd2df6

1 files changed, 4 insertions, 3 deletions

diff --git a/include/stdlib/stdio.h b/include/stdlib/stdio.h
index 60e081b43..57e5c7fa4 100644
--- a/include/stdlib/stdio.h
+++ b/include/stdlib/stdio.h
@@ -58,12 +58,13 @@ typedef	__ssize_t	ssize_t;
 
 #define	EOF	(-1)
 
-int	 printf(const char * __restrict, ...);
+int	 printf(const char * __restrict, ...) __printflike(1, 2);
 int	 putchar(int);
 int	 puts(const char *);
-int	 sprintf(char * __restrict, const char * __restrict, ...);
+int	 sprintf(char * __restrict, const char * __restrict, ...)
+	__printflike(2, 3);
 int	 vsprintf(char * __restrict, const char * __restrict,
-	   __va_list);
+	   __va_list) __printflike(2, 0);
 
 int	 sscanf(const char *__restrict, char const *__restrict, ...);