Merge pull request #4006 from chris-jones-arm/development

Add macro to check error code additions/combinations

tests/include/test/helpers.h

@@ -278,4 +278,20 @@ void mbedtls_test_mutex_usage_init( void );
 void mbedtls_test_mutex_usage_check( void );
 #endif /* MBEDTLS_TEST_MUTEX_USAGE */
 
+#if defined(MBEDTLS_TEST_HOOKS)
+/**
+ * \brief   Check that only a pure high-level error code is being combined with
+ *          a pure low-level error code as otherwise the resultant error code
+ *          would be corrupted.
+ *
+ * \note    Both high-level and low-level error codes cannot be greater than
+ *          zero however can be zero. If one error code is zero then the
+ *          other error code is returned even if both codes are zero.
+ *
+ * \note    If the check fails, fail the test currently being run.
+ */
+void mbedtls_test_err_add_check( int high, int low,
+                                 const char *file, int line);
+#endif
+
 #endif /* TEST_HELPERS_H */