From d8aeaa9c625f72cc4c593a9ebeeffd244c76ae16 Mon Sep 17 00:00:00 2001
From: Sam van Kampen <sam@tehsvk.net>
Date: Sat, 16 May 2020 17:02:07 +0200
Subject: [PATCH] Mark the *printf functions with __attribute__((format)).

Using __attribute__((format)) means that compilers supporting the
attribute (GCC, clang, icc, perhaps others) will automatically issue
warnings when printf arguments are incorrectly typed (i.e. inconsistent
with the type specified in the format string).
---
 printf.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/printf.h b/printf.h
index 6104ccfb..508b45e5 100644
--- a/printf.h
+++ b/printf.h
@@ -58,6 +58,9 @@ void _putchar(char character);
  * \return The number of characters that are written into the array, not counting the terminating null character
  */
 #define printf printf_
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 1, 2)))
+#endif
 int printf_(const char* format, ...);
 
 
@@ -69,6 +72,9 @@ int printf_(const char* format, ...);
  * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character
  */
 #define sprintf sprintf_
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 2, 3)))
+#endif
 int sprintf_(char* buffer, const char* format, ...);
 
 
@@ -84,7 +90,14 @@ int sprintf_(char* buffer, const char* format, ...);
  */
 #define snprintf  snprintf_
 #define vsnprintf vsnprintf_
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 3, 4)))
+#endif
 int  snprintf_(char* buffer, size_t count, const char* format, ...);
+
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 3, 0)))
+#endif
 int vsnprintf_(char* buffer, size_t count, const char* format, va_list va);
 
 
@@ -95,6 +108,9 @@ int vsnprintf_(char* buffer, size_t count, const char* format, va_list va);
  * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character
  */
 #define vprintf vprintf_
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 1, 0)))
+#endif
 int vprintf_(const char* format, va_list va);
 
 
@@ -106,6 +122,9 @@ int vprintf_(const char* format, va_list va);
  * \param format A string that specifies the format of the output
  * \return The number of characters that are sent to the output function, not counting the terminating null character
  */
+#ifdef __GNUC__
+__attribute__ ((format (__printf__, 3, 4)))
+#endif
 int fctprintf(void (*out)(char character, void* arg), void* arg, const char* format, ...);