1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #import "chrome/browser/ui/cocoa/objc_method_swizzle.h" 6 7 #import "base/logging.h" 8 #import "base/memory/scoped_nsobject.h" 9 #import "chrome/app/breakpad_mac.h" 10 11 namespace ObjcEvilDoers { 12 13 Method GetImplementedInstanceMethod(Class aClass, SEL aSelector) { 14 Method method = NULL; 15 unsigned int methodCount = 0; 16 Method* methodList = class_copyMethodList(aClass, &methodCount); 17 if (methodList) { 18 for (unsigned int i = 0; i < methodCount; ++i) { 19 if (method_getName(methodList[i]) == aSelector) { 20 method = methodList[i]; 21 break; 22 } 23 } 24 free(methodList); 25 } 26 return method; 27 } 28 29 IMP SwizzleImplementedInstanceMethods( 30 Class aClass, const SEL originalSelector, const SEL alternateSelector) { 31 // The methods must both be implemented by the target class, not 32 // inherited from a superclass. 33 Method original = GetImplementedInstanceMethod(aClass, originalSelector); 34 Method alternate = GetImplementedInstanceMethod(aClass, alternateSelector); 35 DCHECK(original); 36 DCHECK(alternate); 37 if (!original || !alternate) { 38 return NULL; 39 } 40 41 // The argument and return types must match exactly. 42 const char* originalTypes = method_getTypeEncoding(original); 43 const char* alternateTypes = method_getTypeEncoding(alternate); 44 DCHECK(originalTypes); 45 DCHECK(alternateTypes); 46 DCHECK(0 == strcmp(originalTypes, alternateTypes)); 47 if (!originalTypes || !alternateTypes || 48 strcmp(originalTypes, alternateTypes)) { 49 return NULL; 50 } 51 52 IMP ret = method_getImplementation(original); 53 if (ret) { 54 method_exchangeImplementations(original, alternate); 55 } 56 return ret; 57 } 58 59 } // namespace ObjcEvilDoers 60
