有没有办法确定method
调用某个代码的行?
12 回答
Stack我希望这会有所帮助:
NSString *sourceString = [[NSThread callStackSymbols] objectAtIndex:1];
// Example: 1 UIKit 0x00540c89 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1163
NSCharacterSet *separatorSet = [NSCharacterSet characterSetWithCharactersInString:@" -[]+?.,"];
NSMutableArray *array = [NSMutableArray arrayWithArray:[sourceString componentsSeparatedByCharactersInSet:separatorSet]];
[array removeObject:@""];
NSLog(@"Stack = %@", [array objectAtIndex:0]);
NSLog(@"Framework = %@", [array objectAtIndex:1]);
NSLog(@"Memory address = %@", [array objectAtIndex:2]);
NSLog(@"Class caller = %@", [array objectAtIndex:3]);
NSLog(@"Function caller = %@", [array objectAtIndex:4]);
在完全优化的代码中,没有 100% 可靠的方法来确定某个方法的调用者。编译器可以使用尾调用优化,而编译器有效地为被调用者重用调用者的堆栈帧。
要查看此示例,请使用 gdb 在任何给定方法上设置断点并查看回溯。请注意,您不会在每次方法调用之前看到 objc_msgSend()。那是因为 objc_msgSend() 对每个方法的实现进行了尾调用。
虽然您可以编译未优化的应用程序,但您需要所有系统库的未优化版本才能避免这一问题。
这只是一个问题;实际上,您是在问“我如何重新发明 CrashTracer 或 gdb?”。一个非常困难的问题,职业生涯是在这个问题上产生的。除非您希望“调试工具”成为您的职业,否则我建议您不要走这条路。
你真正想回答什么问题?
使用intropedro提供的答案,我想出了这个:
#define CALL_ORIGIN NSLog(@"Origin: [%@]", [[[[NSThread callStackSymbols] objectAtIndex:1] componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"[]"]] objectAtIndex:1])
这将简单地返回我原来的类和函数:
2014-02-04 16:49:25.384 testApp[29042:70b] Origin: [LCallView addDataToMapView]
ps - 如果使用 performSelector 调用函数,结果将是:
Origin: [NSObject performSelector:withObject:]
刚刚写了一个方法可以为你做到这一点:
- (NSString *)getCallerStackSymbol {
NSString *callerStackSymbol = @"Could not track caller stack symbol";
NSArray *stackSymbols = [NSThread callStackSymbols];
if(stackSymbols.count >= 2) {
callerStackSymbol = [stackSymbols objectAtIndex:2];
if(callerStackSymbol) {
NSMutableArray *callerStackSymbolDetailsArr = [[NSMutableArray alloc] initWithArray:[callerStackSymbol componentsSeparatedByString:@" "]];
NSUInteger callerStackSymbolIndex = callerStackSymbolDetailsArr.count - 3;
if (callerStackSymbolDetailsArr.count > callerStackSymbolIndex && [callerStackSymbolDetailsArr objectAtIndex:callerStackSymbolIndex]) {
callerStackSymbol = [callerStackSymbolDetailsArr objectAtIndex:callerStackSymbolIndex];
callerStackSymbol = [callerStackSymbol stringByReplacingOccurrencesOfString:@"]" withString:@""];
}
}
}
return callerStackSymbol;
}
@Intropedro 的答案的 Swift 2.0 版本供参考;
let sourceString: String = NSThread.callStackSymbols()[1]
let separatorSet :NSCharacterSet = NSCharacterSet(charactersInString: " -[]+?.,")
let array = NSMutableArray(array: sourceString.componentsSeparatedByCharactersInSet(separatorSet))
array.removeObject("")
print("Stack: \(array[0])")
print("Framework:\(array[1])")
print("Memory Address:\(array[2])")
print("Class Caller:\(array[3])")
print("Method Caller:\(array[4])")
如果是为了调试,养成放一个 NSLog(@"%s", __FUNCTION__);
作为类中每个方法的第一行。然后你总是可以通过查看调试器知道方法调用的顺序。
您可以将self
作为参数之一传递给函数,然后在内部获取调用者对象的类名:
+(void)log:(NSString*)data from:(id)sender{
NSLog(@"[%@]: %@", NSStringFromClass([sender class]), data);
}
//...
-(void)myFunc{
[LoggerClassName log:@"myFunc called" from:self];
}
通过这种方式,您可以将任何可以帮助您确定问题所在的对象传递给它。
@ennukiller
//Add this private instance method to the class you want to trace from
-(void)trace
{
//Go back 2 frames to account for calling this helper method
//If not using a helper method use 1
NSArray* stack = [NSThread callStackSymbols];
if (stack.count > 2)
NSLog(@"Caller: %@", [stack objectAtIndex:2]);
}
//Add this line to the method you want to trace from
[self trace];
在输出窗口中,您将看到类似以下内容。
来电者:2 MyApp 0x0004e8ae -[IINClassroomInit buildMenu] + 86
您还可以解析此字符串以提取有关堆栈帧的更多数据。
2 = Thread id
My App = Your app name
0x0004e8ae = Memory address of caller
-[IINClassroomInit buildMenu] = Class and method name of caller
+86 = Number of bytes from the entry point of the caller that your method was called
它取自iOS 中的识别调用方法。
@Roy Kronenfeld 的奇妙答案的略微优化版本:
- (NSString *)findCallerMethod
{
NSString *callerStackSymbol = nil;
NSArray<NSString *> *callStackSymbols = [NSThread callStackSymbols];
if (callStackSymbols.count >= 2)
{
callerStackSymbol = [callStackSymbols objectAtIndex:2];
if (callerStackSymbol)
{
// Stack: 2 TerribleApp 0x000000010e450b1e -[TALocalDataManager startUp] + 46
NSInteger idxDash = [callerStackSymbol rangeOfString:@"-" options:kNilOptions].location;
NSInteger idxPlus = [callerStackSymbol rangeOfString:@"+" options:NSBackwardsSearch].location;
if (idxDash != NSNotFound && idxPlus != NSNotFound)
{
NSRange range = NSMakeRange(idxDash, (idxPlus - idxDash - 1)); // -1 to remove the trailing space.
callerStackSymbol = [callerStackSymbol substringWithRange:range];
return callerStackSymbol;
}
}
}
return (callerStackSymbol) ?: @"Caller not found! :(";
}
@Geoff H 的 Swift 4 版本的复制和粘贴答案;]
let sourceString: String = Thread.callStackSymbols[1]
let separatorSet :CharacterSet = CharacterSet(charactersIn: " -[]+?.,")
var array = Array(sourceString.components(separatedBy: separatorSet))
array = array.filter { $0 != "" }
print("Stack: \(array[0])")
print("Framework:\(array[1])")
print("Memory Address:\(array[2])")
print("Class Caller:\(array[3])")
print("Method Caller:\(array[4])")
Swift 3 版本的@Geoff H 答案供参考:
let sourceString: String = Thread.callStackSymbols[1]
let separatorSet: CharacterSet = CharacterSet(charactersIn: " -[]+?.,")
let array = NSMutableArray(array: sourceString.components(separatedBy: separatorSet))
array.remove("")
print("Stack: \(array[0])")
print("Framework:\(array[1])")
print("Memory Address:\(array[2])")
print("Class Caller:\(array[3])")
print("Method Caller:\(array[4])")
回到过去,objective-C 中没有点语法,所以现在它看起来像。
#define __UGLY__CALLEE__(idx) fprintf(stderr,"\n%s <- %s",__PRETTY_FUNCTION__,(NSThread.callStackSymbols.count>idx?((NSString*)NSThread.callStackSymbols[idx]).UTF8String:"no callStackSymbol with this index"))
只打印需要的内容,无需额外重新创建 NSArray 或 Mutables。除了要输出的字符和要选择的索引之外,您还可以使用不同的堆栈符号重复并打印没有时间戳。对输出进行额外的格式化不仅会降低性能,直到您了解您需要了解的有关方法调用的信息,它也会使事情变得不灵活。最重要的是不要引入另一个方法调用self只是为了请求最后一个被调用者。
__UGLY__CALLEE__(1);
结果是...
-[Some inspectedMethod] <- 1 Appname 0x00000001000e6cd2 -[SomeCallee method] + 1234
而且因为它不漂亮 - 它被称为丑陋。