# BNNSGraphCompileOptionsSetMessageLogMask(_:_:) Sets the mask for compile-time messages. ``` func BNNSGraphCompileOptionsSetMessageLogMask(_ options: bnns_graph_compile_options_t, _ log_level_mask: UInt32) ``` ## Parameters `options` The compilation options object. `log_level_mask` The bit mask of levels that BNNS logs. ## Discussion The default log mask is [`BNNSGraphMessageLevelUnsupported`](/documentation/Accelerate/BNNSGraphMessageLevelUnsupported) | [`BNNSGraphMessageLevelWarning`](/documentation/Accelerate/BNNSGraphMessageLevelWarning) | [`BNNSGraphMessageLevelError`](/documentation/Accelerate/BNNSGraphMessageLevelError). The following code adds a custom graph compile-message callback function that prints [`BNNSGraphMessageLevelInfo`](/documentation/Accelerate/BNNSGraphMessageLevelInfo) level messages to the console: ```swift let options = BNNSGraphCompileOptionsMakeDefault() defer { BNNSGraphCompileOptionsDestroy(options) } BNNSGraphCompileOptionsSetMessageLogMask(options, BNNSGraphMessageLevelInfo.rawValue) BNNSGraphCompileOptionsSetMessageLogCallback(options, messageLogCallback, nil) func messageLogCallback(msg_level: BNNSGraphMessageLevel, error_msg: UnsafePointer, source_location: UnsafePointer?, user_message_data_t:UnsafeMutablePointer?) { print(NSString(cString: error_msg, encoding: NSUTF8StringEncoding) ?? "") if let source_location = source_location { print(NSString(cString: source_location, encoding: NSUTF8StringEncoding) ?? "") } } ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)