Hook addGestureRecognizer:

HookAddGestureRecognizer.m

#import "ViewController.h"
#import <objc/runtime.h>

static NSMutableDictionary *_stack;

NSString *LogGesture(UIGestureRecognizer *gestureRecognizer);

@interface UIView (LogGesture)
- (void)exchangedAddGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer;
@end

@implementation ViewController

- (instancetype)initWithCoder:(NSCoder *)coder
{
    self = [super initWithCoder:coder];
    if (self) {
        Class cls = [UIView class];
        Method m1 = class_getInstanceMethod(cls, @selector(addGestureRecognizer:));
        Method m2 = class_getInstanceMethod(cls, @selector(exchangedAddGestureRecognizer:));
        method_exchangeImplementations(m1, m2);
    }
    return self;
}

- (void)viewDidAppear:(BOOL)animated
{
    NSLog(@"%@", _stack);
}

@end

@implementation UIView (LogGesture)

- (void)exchangedAddGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
{
    if (!_stack) {
        _stack = [NSMutableDictionary dictionary];
    }
    
    NSString *key = NSStringFromClass(self.class);
    NSMutableArray *mArray = _stack[key];
    if (!mArray) {
        mArray = [NSMutableArray array];
        _stack[key] = mArray;
    }
    NSString *string = LogGesture(gestureRecognizer);
    [mArray removeObject:string];
    [mArray addObject:string];
    
    [self exchangedAddGestureRecognizer:gestureRecognizer];
}

@end

NSString *LogGesture(UIGestureRecognizer *gestureRecognizer) {
    id object = [[gestureRecognizer valueForKey:@"targets"] firstObject];
    id target = [object valueForKey:@"target"];
    Ivar ivar = class_getInstanceVariable([object class], "_action");
    SEL action = (__bridge void *)object_getIvar(object, ivar);
    NSMutableString *mString = [NSMutableString stringWithFormat:@"%@; action=%@; target=%@;",
                                NSStringFromClass(gestureRecognizer.class),
                                NSStringFromSelector(action),
                                NSStringFromClass([target class])];
    if ([gestureRecognizer respondsToSelector:@selector(numberOfTouchesRequired)]) {
        NSUInteger number = [(id)gestureRecognizer numberOfTouchesRequired];
        if (number != 0) {
            [mString appendFormat:@" numberOfTouchesRequired=%lu;", (unsigned long)number];
        }
    }
    if ([gestureRecognizer respondsToSelector:@selector(numberOfTapsRequired)]) {
        NSUInteger number = [(id)gestureRecognizer numberOfTapsRequired];
        if (number != 0) {
            [mString appendFormat:@" numberOfTapsRequired=%lu;", (unsigned long)number];
        }
    }
    return mString.copy;
}