Add ScopedObjCClassSwizzler in base/mac, absorbs objc_method_swizzle and ScopedClassSwizzler

chrome/browser/chrome_browser_application_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/chrome_browser_application_mac.h"
 
 #import "base/auto_reset.h"
 #include "base/debug/crash_logging.h"
 #include "base/debug/stack_trace.h"
 #import "base/logging.h"
 #import "base/mac/scoped_nsexception_enabler.h"
 #import "base/mac/scoped_nsobject.h"
+#import "base/mac/scoped_objc_class_swizzler.h"
 #import "base/metrics/histogram.h"
 #include "base/strings/stringprintf.h"
 #import "base/strings/sys_string_conversions.h"
 #import "chrome/browser/app_controller_mac.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_iterator.h"
 #include "chrome/common/crash_keys.h"
-#import "chrome/common/mac/objc_method_swizzle.h"
 #import "chrome/common/mac/objc_zombie.h"
 #include "content/public/browser/browser_accessibility_state.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 
 namespace {
 
-// Tracking for cases being hit by -crInitWithName:reason:userInfo:.
+// Tracking for cases being hit by -initWithName:reason:userInfo:.
 enum ExceptionEventType {
   EXCEPTION_ACCESSIBILITY = 0,
   EXCEPTION_MENU_ITEM_BOUNDS_CHECK,
   EXCEPTION_VIEW_NOT_IN_WINDOW,
   EXCEPTION_NSURL_INIT_NIL,
   EXCEPTION_NSDATADETECTOR_NIL_STRING,
 
   // Always keep this at the end.
   EXCEPTION_MAX,
 };
 
 void RecordExceptionEvent(ExceptionEventType event_type) {
   UMA_HISTOGRAM_ENUMERATION("OSX.ExceptionHandlerEvents",
                             event_type, EXCEPTION_MAX);
 }
 
 }  // namespace
 
 // The implementation of NSExceptions break various assumptions in the
-// Chrome code.  This category defines a replacement for
+// Chrome code.  This interface defines a replacement for
 // -initWithName:reason:userInfo: for purposes of forcing a break in
 // the debugger when an exception is raised.  -raise sounds more
 // obvious to intercept, but it doesn't catch the original throw
 // because the objc runtime doesn't use it.
-@interface NSException (CrNSExceptionSwizzle)
-- (id)crInitWithName:(NSString*)aName
-              reason:(NSString*)aReason
-            userInfo:(NSDictionary*)someUserInfo;
+@interface CrNSExceptionInitDonor : NSObject
+- (id)initWithName:(NSString*)aName
+            reason:(NSString*)aReason
+          userInfo:(NSDictionary*)someUserInfo;
 @end
 
 static IMP gOriginalInitIMP = NULL;
 
-@implementation NSException (CrNSExceptionSwizzle)
-- (id)crInitWithName:(NSString*)aName
-              reason:(NSString*)aReason
-            userInfo:(NSDictionary*)someUserInfo {
+@implementation CrNSExceptionInitDonor
+- (id)initWithName:(NSString*)aName
+            reason:(NSString*)aReason
+          userInfo:(NSDictionary*)someUserInfo {
   // Method only called when swizzled.
-  DCHECK(_cmd == @selector(initWithName:reason:userInfo:));
+  DCHECK(gOriginalInitIMP);
 
   // Parts of Cocoa rely on creating and throwing exceptions. These are not
   // worth bugging-out over. It is very important that there be zero chance that
   // any Chromium code is on the stack; these must be created by Apple code and
   // then immediately consumed by Apple code.
   static NSString* const kAcceptableNSExceptionNames[] = {
     // If an object does not support an accessibility attribute, this will
     // get thrown.
     NSAccessibilityException,
   };
 
   BOOL found = NO;
   for (size_t i = 0; i < arraysize(kAcceptableNSExceptionNames); ++i) {
     if (aName == kAcceptableNSExceptionNames[i]) {
       found = YES;
       RecordExceptionEvent(EXCEPTION_ACCESSIBILITY);
       break;
     }
   }
 
   if (!found) {
     // Update breakpad with the exception info.
     std::string value = base::StringPrintf("%s reason %s",
         [aName UTF8String], [aReason UTF8String]);
     base::debug::SetCrashKeyValue(crash_keys::mac::kNSException, value);

[tapted, 2014/07/25 06:59:56]

note

     base::debug::SetCrashKeyToStackTrace(crash_keys::mac::kNSExceptionTrace,
                                          base::debug::StackTrace());
 
     // Force crash for selected exceptions to generate crash dumps.
     BOOL fatal = NO;
     if (aName == NSInternalInconsistencyException) {
       NSString* const kNSMenuItemArrayBoundsCheck =
           @"Invalid parameter not satisfying: (index >= 0) && "
           @"(index < [_itemArray count])";
       if ([aReason isEqualToString:kNSMenuItemArrayBoundsCheck]) {
@@ skipping 127 matching lines @@
 }
 
 }  // namespace chrome_browser_application_mac
 
 namespace {
 
 void SwizzleInit() {
   // Do-nothing wrapper so that we can arrange to only swizzle
   // -[NSException raise] when DCHECK() is turned on (as opposed to
   // replicating the preprocess logic which turns DCHECK() on).
-  gOriginalInitIMP = ObjcEvilDoers::SwizzleImplementedInstanceMethods(
-      [NSException class],
-      @selector(initWithName:reason:userInfo:),
-      @selector(crInitWithName:reason:userInfo:));
+  CR_DEFINE_STATIC_LOCAL(base::mac::ScopedObjCClassSwizzler,
+                         swizzle_exception,
+                         ([NSException class],
+                          [CrNSExceptionInitDonor class],
+                          @selector(initWithName:reason:userInfo:)));
+  gOriginalInitIMP = swizzle_exception.GetOriginalImplementation();
 }
 
 }  // namespace
 
 // These methods are being exposed for the purposes of overriding.
 // Used to determine when a Panel window can become the key window.
 @interface NSApplication (PanelsCanBecomeKey)
 - (void)_cycleWindowsReversed:(BOOL)arg1;
 - (id)_removeWindow:(NSWindow*)window;
 - (id)_setKeyWindow:(NSWindow*)window;
@@ skipping 353 matching lines @@
   std::vector<NSWindow*>::iterator window_iterator =
       std::find(previousKeyWindows_.begin(),
                 previousKeyWindows_.end(),
                 window);
   if (window_iterator != previousKeyWindows_.end()) {
     previousKeyWindows_.erase(window_iterator);
   }
 }
 
 @end