Xcode #ifdef Debug did not perform the processing

Today, I wrote the following line of code in the. pch file to help me navigate to the line number of the output, and the results did not work, to record:

1 #ifdef DEBUG 2 #define SLog (FMT, ...) NSLog (@ "%s [line%d]" FMT), __pretty_function__, __line__, # #__VA_ARGS__); 3 #else 4 #define SLog (...) 5 #endif

But the use of time at all did not execute to #ifdef debug here, often online to find the answer, finally resolved. The resolution process is as follows:

Find preprocessor Macros This property in build settings, for debug configuration we write to him debug and leave it blank in the release configuration. This allows us to control the output of the nslog by determining whether we compile the debug version or the release version based on this flag.

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Xcode #ifdef Debug did not perform the processing