Objective-C generated code results in module redefinition

[brianquinlan]

If I manually fix the issues in #1269, I get a compilation error:

Lexical or Preprocessor Issue (Xcode): Redefinition of module 'Foundation'
/System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/Sy
stem/Library/Frameworks/Foundation.framework/Modules/module.modulemap:0:17

I think that is because the includes are not generated correctly:

#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSArray.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSData.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSDictionary.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSURLCache.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSURLRequest.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSURLSession.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSURL.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSProgress.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSURLResponse.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSHTTPCookieStorage.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSOperation.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSError.h"
#include "../../../../../../../System/Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Headers/NSDictionary.h"

Objective-C headers don't have header guards so I think that you need import rather than include.

Also, I'm not sure if the compiler will realize that #import "../../foo.h" and #import <foo.h> refer to the same file.

[liamappelbe]

Does it work if you switch them to import?

[brianquinlan]

Does it work if you switch them to import?

No. But changing them to:

#import <Foundation/NSArray.h>

did work. As did removing them completely (because they are transitively included by "CUPHTTPClientDelegate.h").

I would also expect these relative paths to only work on my Mac.