Can preprocessor directives be used to import different header files for Mac and iOS?

Question

I am writing a class library for Mac OS X and iOS to be released as a Cocoa Framework for OS X and a Static Library for iOS. To simplify matters, I intend to use multiple targets in Xcode. However, the classes on Mac OS X link against Cocoa.h whereas on iOS they link against Foundation.h.

My questions basically are:

• Could the Mac OS X framework link against Foundation.framework instead? Classes used within the framework are NSString, NSMutableString, and NSMutableArray.

• Or could I use preprocessor directives within the header files to control framework inclusion, e.g.

  #ifdef MacOSX
      #import <Cocoa/Cocoa.h>
  #else
      #import <Foundation/Foundation.h>
  #endif
  

Answer 1

This works perfectly for me:

#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED
//iOS 
#else
//Mac
#endif

Answer 2

It works like a charm:

#ifdef __APPLE__
  #include "TargetConditionals.h"

  #if TARGET_IPHONE_SIMULATOR  
  // ios simulator

  #elif TARGET_OS_IPHONE
  // ios device

  #elif TARGET_OS_MAC
  // mac os 

  #else
  // Unsupported platform
  #endif
#endif

Answer 3

You can use these to separate platform dependent code (see TargetConditionals.h):

#ifdef TARGET_OS_IPHONE 
    // iOS
#elif defined TARGET_IPHONE_SIMULATOR
    // iOS Simulator
#elif defined TARGET_OS_MAC
    // Other kinds of Mac OS
#else
    // Unsupported platform
#endif

Here's a useful chart.

Answer 4

• Could the Mac OS X framework link against Foundation.framework instead? Classes used within the framework are NSString, NSMutableString, and NSMutableArray.

Try it and see. If the compile fails, no. If it succeeds, yes.

• Or could I use preprocessor directives within the header files to control framework inclusion, e.g.

Yes, you can. In fact, I believe that is the only way to do that.