1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_APPLE_SCOPED_OBJC_CLASS_SWIZZLER_H_
#define BASE_APPLE_SCOPED_OBJC_CLASS_SWIZZLER_H_
#import <objc/runtime.h>
#include "base/base_export.h"
namespace base::apple {
// Within a given scope, swaps method implementations of a class interface, or
// between two class interfaces. The argument and return types must match.
class BASE_EXPORT ScopedObjCClassSwizzler {
public:
// Given two classes that each respond to |selector|, swap the implementations
// of those methods.
ScopedObjCClassSwizzler(Class target, Class source, SEL selector);
// Given two selectors on the same class interface, |target| (e.g. via
// inheritance or categories), swap the implementations of methods |original|
// and |alternate|.
ScopedObjCClassSwizzler(Class target, SEL original, SEL alternate);
ScopedObjCClassSwizzler(const ScopedObjCClassSwizzler&) = delete;
ScopedObjCClassSwizzler& operator=(const ScopedObjCClassSwizzler&) = delete;
~ScopedObjCClassSwizzler();
// Return a callable function pointer for the replaced method. To call this
// from the replacing function, the first two arguments should be |self| and
// |_cmd|. These are followed by the (variadic) method arguments.
IMP GetOriginalImplementation() const;
// Invoke the original function directly, optionally with some arguments.
// Prefer this to hanging onto pointers to the original implementation
// function or to casting the result of GetOriginalImplementation() yourself.
template <typename Ret, typename... Args>
Ret InvokeOriginal(id receiver, SEL selector, Args... args) const {
auto func = reinterpret_cast<Ret (*)(id, SEL, Args...)>(
GetOriginalImplementation());
return func(receiver, selector, args...);
}
private:
// Delegated constructor.
void Init(Class target, Class source, SEL original, SEL alternate);
Method old_selector_impl_;
Method new_selector_impl_;
};
} // namespace base::apple
#endif // BASE_APPLE_SCOPED_OBJC_CLASS_SWIZZLER_H_
|
