.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface LGHookInfo : NSObject
@property (nonatomic, weak) id _Nullable target;
@property (nonatomic, copy) NSString * _Nullable selector;
@property (nonatomic, strong) NSArray * _Nullable args;
@property (nonatomic, assign) id _Nonnull result;
@end
typedef void(^CallBack)(LGHookInfo * _Nullable info);
@interface LGHookBlock : NSObject
+ (void)hookBlock:(id)obj callBack:(CallBack)callBack;
@end
NS_ASSUME_NONNULL_END
.m
#import "LGHookBlock.h"
#import <objc/message.h>
#define LG_MethodHook(selector, func) {Method method = class_getInstanceMethod([NSObject class], selector); \
BOOL success = class_addMethod(cls, selector, (IMP)func, method_getTypeEncoding(method)); \
if (!success) { class_replaceMethod(cls, selector, (IMP)func, method_getTypeEncoding(method));}}
typedef NS_OPTIONS(int, LGBlockFlage) {
LGBLOCK_HAS_COPY_DISPOSE = (1 << 25),
LGBLOCK_HAS_SIGNATURE = (1 << 30)
};
struct LGBlock_descriptor_1{
uintptr_t reserved;
uintptr_t size;
};
struct LGBlock_descriptor_2 {
// requires BLOCK_HAS_COPY_DISPOSE
void (*copy)(void *dst, const void *src);
void (*dispose)(const void *);
};
struct LGBlock_descriptor_3 {
// requires BLOCK_HAS_SIGNATURE
const char *signature;
const char *layout;
};
struct LGBlock_layout {
void *isa;
volatile int32_t flags;
int32_t reserved;
void (*invoke)(void *, ...);
struct LGBlock_descriptor_1 *descriptor;
};
typedef struct LGBlock_layout *LGBlock;
@implementation LGHookBlock
+ (void)hookBlock:(id)obj callBack:(CallBack)callBack{
lg_block_hook(obj);
}
//MARK: - hook 核心
static void lg_block_hook(id obj) {
LGBlock block = (__bridge LGBlock)obj;
struct LGBlock_descriptor_1 *des1 = block->descriptor;
des1->reserved = block->invoke;
struct LGBlock_descriptor_3 *des3 = _lg_Block_descriptor_3(block);
block->invoke = (void *)lg_getMsgForward(des3->signature);
}
//MARK: - lg_getMsgForward
static IMP lg_getMsgForward(const char *methodTypes) {
IMP msgForwardIMP = _objc_msgForward;
#if !defined(__arm64__)
if (methodTypes[0] == '{') {
NSMethodSignature *methodSignature = [NSMethodSignature signatureWithObjCTypes:methodTypes];
if ([methodSignature.debugDescription rangeOfString:@"is special struct return? YES"].location != NSNotFound) {
msgForwardIMP = (IMP)_objc_msgForward_stret;
}
}
#endif
return msgForwardIMP;
}
static void LG_NSBlock_hookOnces() {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class cls = NSClassFromString(@"NSBlock");
#define LG_MethodHook(selector, func) {Method method = class_getInstanceMethod([NSObject class], selector); \
BOOL success = class_addMethod(cls, selector, (IMP)func, method_getTypeEncoding(method)); \
if (!success) { class_replaceMethod(cls, selector, (IMP)func, method_getTypeEncoding(method));}}
LG_MethodHook(@selector(methodSignatureForSelector:), lg_BlockMethodSignatureForSelector);
LG_MethodHook(@selector(forwardInvocation:), lg_BlockforwardInvocation);
});
}
NSMethodSignature *lg_BlockMethodSignatureForSelector(id self, SEL _cmd, SEL aSelector) {
struct LGBlock_descriptor_3 *des3 = _lg_Block_descriptor_3((__bridge void *)self);
return [NSMethodSignature signatureWithObjCTypes:des3->signature];
}
static void lg_BlockforwardInvocation(id self, SEL _cmd, NSInvocation *invo) {
LGBlock block = (__bridge void *)invo.target;
struct LGBlock_descriptor_1 *des1 = block->descriptor;
void (*KCBlock)(void *,...) = des1->reserved;
KCBlock(block);
}
static struct LGBlock_descriptor_3 * _lg_Block_descriptor_3(LGBlock aBlock)
{
if (! (aBlock->flags & LGBLOCK_HAS_SIGNATURE)) return nil;
uint8_t *desc = (uint8_t *)aBlock->descriptor;
desc += sizeof(struct LGBlock_descriptor_1);
if (aBlock->flags & LGBLOCK_HAS_COPY_DISPOSE) {
desc += sizeof(struct LGBlock_descriptor_2);
}
return (struct LGBlock_descriptor_3 *)desc;
}
//MARK: - hook 完毕的信息回调处理
static LGHookInfo *_lg_getCallback(NSInvocation *invocation) {
LGHookInfo *callBack = [[LGHookInfo alloc] init];
callBack.target = invocation.target;
if ([callBack.target isKindOfClass:NSClassFromString(@"NSBlock")]) {
callBack.args = _lg_getArguments(invocation,1);
}
callBack.result = _lg_getReturnValue(invocation);
return callBack;
}
//MARK: - 参数处理
static NSArray *_lg_getArguments(NSInvocation *invocation, NSInteger beginIndex) {
NSMutableArray *args = [NSMutableArray new];
for (NSInteger i = beginIndex; i < [invocation.methodSignature numberOfArguments]; i ++) {
const char *argType = [invocation.methodSignature getArgumentTypeAtIndex:i];
id argBox;
#define IIFish_GetArgumentValueInBox(coding, type) case coding : {\
type arg;\
[invocation getArgument:&arg atIndex:i];\
argBox = @(arg);\
} break;
switch (argType[0]) {
IIFish_GetArgumentValueInBox('c', char)
IIFish_GetArgumentValueInBox('i', int)
IIFish_GetArgumentValueInBox('s', short)
IIFish_GetArgumentValueInBox('l', long)
IIFish_GetArgumentValueInBox('q', long long)
IIFish_GetArgumentValueInBox('^', long long)
IIFish_GetArgumentValueInBox('C', unsigned char)
IIFish_GetArgumentValueInBox('I', unsigned int)
IIFish_GetArgumentValueInBox('S', unsigned short)
IIFish_GetArgumentValueInBox('L', unsigned long)
IIFish_GetArgumentValueInBox('Q', unsigned long long)
IIFish_GetArgumentValueInBox('f', float)
IIFish_GetArgumentValueInBox('d', double)
IIFish_GetArgumentValueInBox('B', BOOL)
case '*': {
char *arg;
[invocation getArgument:&arg atIndex:i];
argBox = [[NSString alloc] initWithUTF8String:arg];
} break;
case '@': {
__autoreleasing id arg;
[invocation getArgument:&arg atIndex:i];
__weak id weakArg = arg;
argBox = ^(){return weakArg;};
} break;
case '#': {
Class arg;
[invocation getArgument:&arg atIndex:i];
argBox = NSStringFromClass(arg);
} break;
case ':': {
SEL arg;
[invocation getArgument:&arg atIndex:i];
argBox = NSStringFromSelector(arg);
} break;
case '{': {
NSUInteger valueSize = 0;
NSGetSizeAndAlignment(argType, &valueSize, NULL);
unsigned char arg[valueSize];
[invocation getArgument:&arg atIndex:i];
argBox = [NSValue value:arg withObjCType:argType];
} break;
default: {
void *arg;
[invocation getArgument:&arg atIndex:i];
argBox = (__bridge id)arg;
}
}
if (argBox) {
[args addObject:argBox];
}
}
return args;
}
//MARK: - 返回值处理
static id _lg_getReturnValue(NSInvocation *invocation) {
const char *argType = [invocation.methodSignature methodReturnType];
id argBox;
#define IIFish_GetReturnValueInBox(coding, type) case coding : {\
type arg;\
[invocation getReturnValue:&arg];\
argBox = @(arg);\
} break;
switch (argType[0]) {
IIFish_GetReturnValueInBox('c', char)
IIFish_GetReturnValueInBox('i', int)
IIFish_GetReturnValueInBox('s', short)
IIFish_GetReturnValueInBox('l', long)
IIFish_GetReturnValueInBox('q', long long)
IIFish_GetReturnValueInBox('^', long long)
IIFish_GetReturnValueInBox('C', unsigned char)
IIFish_GetReturnValueInBox('I', unsigned int)
IIFish_GetReturnValueInBox('S', unsigned short)
IIFish_GetReturnValueInBox('L', unsigned long)
IIFish_GetReturnValueInBox('Q', unsigned long long)
IIFish_GetReturnValueInBox('f', float)
IIFish_GetReturnValueInBox('d', double)
IIFish_GetReturnValueInBox('B', BOOL)
case '*': {
char *arg;
[invocation getReturnValue:&arg];
argBox = [[NSString alloc] initWithUTF8String:arg];
} break;
case '@': {
__autoreleasing id arg;
[invocation getReturnValue:&arg];
__weak id weakArg = arg;
argBox = ^(){return weakArg;};
} break;
case '#': {
Class arg;
[invocation getReturnValue:&arg];
argBox = NSStringFromClass(arg);
} break;
case ':': {
SEL arg;
[invocation getReturnValue:&arg];
argBox = NSStringFromSelector(arg);
} break;
case '{': {
NSUInteger valueSize = 0;
NSGetSizeAndAlignment(argType, &valueSize, NULL);
unsigned char arg[valueSize];
[invocation getReturnValue:&arg];
argBox = [NSValue value:arg withObjCType:argType];
} break;
case 'v':
break;
default: {
void *arg;
[invocation getReturnValue:&arg];
argBox = (__bridge id)arg;
}
}
return argBox;
}
@end
