NDVXcodeRemoteDevicePatch.m

/**

 Prevent Xcode 4.1 from using 100% CPU due to a bug while attempting to
 connect to a remote iOS device.
 
 # 1. Compile the patch
 $ gcc -lobjc -fobjc-gc -framework Foundation -bundle -o _patch NDVXcodeRemoteDevicePatch.m
 
 # 2. Find the PID of Xcode
 $ XcodePID=`pidof Xcode`
 
 # 3. Inject the patch
 $ cat <<EOM | gdb -quiet > /dev/null
   attach $XcodePID
   p (void *)dlopen("_patch", 2)
   detach
 EOM
 
**/

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

void inject_init(void) __attribute__((constructor));
void inject_init(void) {
  BOOL (^patchBlock)(id, id, NSError**) = ^(id _self, id cache, NSError** outError) {
    NSLog(@"Patched version of getNeedsToFetchSharedCache:error: called.");

    if (outError != NULL)
      *outError = nil;

    return NO;
  };

  BOOL (*patchIMP)(id, SEL, id, NSError**) = (void*)imp_implementationWithBlock(patchBlock);

  SEL originalSelector = @selector(getNeedsToFetchSharedCache:error:);
  SEL patchedSelector = @selector(patchedGetNeedsToFetchSharedCache:error:);

  Class classToPatch = NSClassFromString(@"DTDKRemoteDeviceToken");
  Method originalMethod = class_getInstanceMethod(classToPatch, originalSelector);

  BOOL patchedMethodAdded = class_addMethod(classToPatch, patchedSelector, (IMP)patchIMP, method_getTypeEncoding(originalMethod));
  NSLog(@"Patched method successfully added: %@", patchedMethodAdded? @"yes" : @"no");

  Method patchedMethod = class_getInstanceMethod(classToPatch, patchedSelector);

  method_exchangeImplementations(originalMethod, patchedMethod);
}