Objective-C 源碼初探 __attribute__

標籤：

#import <Foundation/Foundation.h>#define onExit\    __strong void (^block)() __attribute__((cleanup(cleanup),unused)) = ^__attribute__((constructor)) void ExecuteBefore_main(){    printf("ExecuteBefore_main\n");}__attribute__((destructor)) void ExecuteAfter_main(){    printf("ExecuteAfter_main\n");}void functionDeprecatedAndObsoleteWarningAndError() __attribute__ ((availability(macosx,introduced=10.4,deprecated=10.10,obsoleted=10.13)));void functionDeprecatedAndObsoleteWarningAndError(void){    }int returnValueNotUnusedWarning() __attribute__ ((warn_unused_result));int returnValueNotUnusedWarning(){    return 1;}void cleanup(__strong void (^*block)()){    (*block)();}int main(int argc, const char * argv[]) {    @autoreleasepool {                printf("Hello, World!\n");                functionDeprecatedAndObsoleteWarningAndError();        returnValueNotUnusedWarning();        onExit{            printf("onExit\n");        };    }    return 0;}

 

Objective-C 源碼初探 __attribute__