Declare mbedtls_debug_print_msg as printf-like
We were not getting any warnings on printf format errors, as we do not
explicitly use printf anywhere in the code. Thankfully there is a way
to mark a function as having printf behaviour so that its inputs can be
checked in the same way as printf would be.
Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/include/mbedtls/debug.h b/include/mbedtls/debug.h
index ab5b037..cd522f5 100644
--- a/include/mbedtls/debug.h
+++ b/include/mbedtls/debug.h
@@ -80,6 +80,25 @@
#endif /* MBEDTLS_DEBUG_C */
+/**
+ * \def MBEDTLS_PRINTF_ATTRIBUTE
+ *
+ * Mark a function as having printf attributes, and thus enable checking
+ * via -wFormat and other flags. This does nothing in windows builds as the
+ * windows compiler does not support it.
+ *
+ * Module: library/debug.c
+ * Caller:
+ *
+ * This module provides debugging functions.
+ */
+#if (defined(_WIN32) || defined(_WIN64))
+#define MBEDTLS_PRINTF_ATTRIBUTE(string_index, first_to_check)
+#else
+#define MBEDTLS_PRINTF_ATTRIBUTE(string_index, first_to_check) \
+ __attribute__((format (printf, string_index, first_to_check)))
+#endif
+
#ifdef __cplusplus
extern "C" {
#endif
@@ -118,7 +137,7 @@
*/
void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
- const char *format, ... );
+ const char *format, ... ) MBEDTLS_PRINTF_ATTRIBUTE(5, 6);
/**
* \brief Print the return value of a function to the debug output. This
diff --git a/library/debug.c b/library/debug.c
index c3384be..e91d1ad 100644
--- a/library/debug.c
+++ b/library/debug.c
@@ -74,6 +74,7 @@
#endif
}
+MBEDTLS_PRINTF_ATTRIBUTE(5, 6)
void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *format, ... )
