如何在Objective-C中挂接Apple的`os_log_with_type`方法

Question

我想挂接"React Native“RCTLog日志方法_RCTLogJavaScriptInternal，源代码是：

void _RCTLogJavaScriptInternal(RCTLogLevel level, NSString *message)
{
  RCTLogFunction logFunction = RCTGetLocalLogFunction();
  BOOL log = RCT_DEBUG || (logFunction != nil);
  if (log && level >= RCTGetLogThreshold()) {
    if (logFunction) {
      logFunction(level, RCTLogSourceJavaScript, nil, nil, message);
    }
  }
}

RCTLogFunction RCTDefaultLogFunction =
    ^(RCTLogLevel level,
      RCTLogSource source,
      __unused NSString *fileName,
      __unused NSNumber *lineNumber,
      NSString *message) {
      os_log_with_type(RCTLogForLogSource(source), RCTLogTypeForLogLevel(level), "%{public}s", message.UTF8String);
    };

因此，如果我只连接苹果的os_log_with_type，我将获得RCTLog日志。这是我的代码，但不起作用。请帮帮我。谢谢！

#import <os/log.h>
#import "fishhook.h"

static void (*original_oslog)((os_log_t log, os_log_type_t type, const char *format, ...));

void hook_oslog(os_log_t log, os_log_type_t type, const char *format, ...) {
    NSLog(@"hook success!");
}

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        struct rebinding oslog_rebinding = { "os_log_with_type", hook_oslog, (void *)&original_oslog };
        rebind_symbols((struct rebinding[1]){oslog_rebinding}, 1);
    });
}

Answer 1

最后，我找到了解决方案。不需要钩子，React Native已经提供了相关接口。

RCTSetLogFunction(^(RCTLogLevel level, RCTLogSource source, NSString *fileName, NSNumber *lineNumber, NSString *message) {
  NSLog(@"%@", message);
});