Make MBEDTLS_IGNORE_RETURN configurable
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index dadd8a3..a536612 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3733,6 +3733,14 @@
*/
//#define MBEDTLS_CHECK_RETURN __attribute__((__warn_unused_result__))
+/** \def MBEDTLS_IGNORE_RETURN
+ *
+ * This macro requires one argument, which should be a C function call.
+ * If that function call would cause a #MBEDTLS_CHECK_RETURN warning, this
+ * warning is suppressed.
+ */
+//#define MBEDTLS_IGNORE_RETURN( result ) ((void) !(result))
+
/* PSA options */
/**
* Use HMAC_DRBG with the specified hash algorithm for HMAC_DRBG for the
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 7e8046a..e08644d 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -176,6 +176,9 @@
* #MBEDTLS_CHECK_RETURN is implemented for the compiler in use and
* #MBEDTLS_CHECK_RETURN_WARNING is enabled in the compile-time configuration.
*
+ * You can use #MBEDTLS_IGNORE_RETURN to explicitly ignore the return value
+ * of a function that is annotated with #MBEDTLS_CHECK_RETURN.
+ *
* \note The use of this macro is a work in progress.
* This macro will be added to more functions in the future.
* Eventually this should appear before most functions returning
@@ -203,8 +206,10 @@
/** \def MBEDTLS_IGNORE_RETURN
*
- * Silences warning about unused return value given by functions
- * with \c MBEDTLS_CHECK_RETURN attribute.
+ * Call this macro with one argument, a function call, to suppress a warning
+ * from #MBEDTLS_CHECK_RETURN due to that function call.
+ */
+#if !defined(MBEDTLS_IGNORE_RETURN)
/* GCC doesn't silence the warning with just (void)(result).
* !(void)(result) is known to work up at least up to GCC 10, as well
* as with Clang and MSVC.
@@ -214,6 +219,7 @@
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425#c34
*/
#define MBEDTLS_IGNORE_RETURN(result) ( (void) !( result ) )
+#endif
/**
* \brief Securely zeroize a buffer