warn about unused return value for set_logger_level

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

rcl/include/rcl/logging_external_interface.h

@@ -19,6 +19,10 @@
 #include "rcl/types.h"
 #include "rcl/visibility_control.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /// Initialize the external logging library.
 /**
  * \param[in] config_file The location of a config file that the external
@@ -78,6 +82,11 @@ rcl_logging_external_log(int severity, const char * name, const char * msg);
  * \return RCL_RET_ERROR if an unspecified error occurs.
  */
 RCL_PUBLIC
+RCL_WARN_UNUSED
 rcl_ret_t rcl_logging_external_set_logger_level(const char * name, int level);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // RCL__LOGGING_EXTERNAL_INTERFACE_H_

rcl/include/rcl/macros.h

@@ -20,14 +20,10 @@ extern "C"
 {
 #endif
 
-#ifndef _WIN32
 /// Ignored return values of functions with this macro will emit a warning.
-# define RCL_WARN_UNUSED __attribute__((warn_unused_result))
-#else
-# define RCL_WARN_UNUSED _Check_return_
-#endif
+#define RCL_WARN_UNUSED RCUTILS_WARN_UNUSED
 
-#define RCL_UNUSED(x) (void)(x)
+#define RCL_UNUSED(x) RCUTILS_UNUSED(x)
 
 #ifdef __cplusplus
 }