[SR-2250] Include Foundation framework instead of minimal NSObject.h

[maniramezan]

This change is for preventing scenarios like https://bugs.swift.org/projects/SR/issues/SR-2250

As suggested by Jordan, adding Foundation framework as a default instead of NSObject.h to prevent situations when only bridge types are used and Foundation never imports and causes an error on generated -Swift.h file.

Resolves SR-2250

[jrose-apple]

Thanks for working on this, Mani!

[jrose-apple]

Hm, it's kind of weird to be putting this in PrintAsObjC/Inputs/ if tests from other folders are going to be using it too. Maybe it'd be better to put it in the normal "mock SDK" (test/Inputs/clang-importer-sdk/Frameworks/ or something) and have it include <Foundation.h> there?

[maniramezan]

Thank you for reviewing it. Yeah that makes sense, it felt weird to me also to point to this file from other tests. I'll move the file and and have it include <Foundation.h> instead.

[maniramezan]

Thank you for your time to help me through it.

There are currently three tests failing that I can't figure out why or how to get the root cause of it:

• resolve-cross-language.swift -verify

useBaseClass() // expected-error{{missing argument for parameter #1}}
              ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

<unknown>:0: error: unexpected error produced: could not build Objective-C module '_SwiftCoreFoundationOverlayShims'
<unknown>:0: error: fatal error encountered while in -verify mode

• Empty.swift Both compiling with -std=c++98 or -std=c++14 fails with following error:

In file included from /swift-source/build/Ninja-DebugAssert/swift-macosx-x86_64/test-macosx-x86_64/PrintAsObjC/Output/empty.swift.tmp/empty.h:23:
In file included from /swift-source/swift/test/Inputs/clang-importer-sdk/frameworks/Foundation.framework/Headers/Foundation.h:1:
In file included from /swift-source/swift/test/Inputs/clang-importer-sdk/usr/include/Foundation.h:7:
/swift-source/swift/test/Inputs/clang-importer-sdk/usr/include/CoreFoundation.h:6:22: error: default initialization of an object of const type 'const CFAllocatorRef' (aka 'const __CFAllocator *const')
const CFAllocatorRef kCFAllocatorDefault;

[jrose-apple]

Thanks for continuing to work on this! Good catch removing the explicit -include Foundation.h too.

[jrose-apple]

I think since this is always relative to %clang-importer-sdk-path, it's fine not to have a separate substitution for it. Substitutions are additional complexity if we're not actually making use of the flexibility.

[maniramezan]

Aw, didn't know about the complexity of it. The reason added it was that it seems in the swift files, path to clang-importer-sdk is always hardcoded, like %S/../../Inputs/clang-importer-sdk/..., wanted to prevent that. But sounds good. Seems in the lit.cfg I can use clang-importer-sdk-path, but in the files, have to give it a relative path. I'll update the code with these changes.

[jrose-apple]

I would expect %clang-importer-sdk-path/frameworks to work in the individual files. What behavior are you seeing?

[maniramezan]

That's what I also expected. It works fine with lit.local.cfg as '-F %%clang-importer-sdk-path/frameworks ' but for using it in lit use cases like here, -F %clang-importer-sdk-path/frameworks is turnt into -F 'path-to-swift-repo/test/Inputs/clang-importer-sdk/' /frameworks

[jrose-apple]

Hm. I would expect it to be -F 'path-to-swift-repo/test/Inputs/clang-importer-sdk/'/frameworks (no space), which should still work. Are you sure you didn't have a typo? We have other examples of this kind of thing working.

[maniramezan]

You're right, seems I was using different substitution that was causing that behavior. Thanks for the example, I went ahead and update the classes to use this pattern

[jrose-apple]

We didn't really design the fake Foundation to work with C++, but I guess we need to now. For Empty.swift, adding extern at the start of the kCFAllocatorDefault declaration should be sufficient. For resolve-cross-language.swift, I suspect we're in a weird place where the dummy CoreFoundation isn't compatible with the real CoreFoundation overlay. We should be using %clang-importer-sdk instead of %clang-importer-sdk-nosource in that test, by consistency with other files in the directory.

[jrose-apple]

Okay, let's try it!

@swift-ci Please test

[jrose-apple]

@swift-ci Please test source compatibility

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 9df5adb

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 9df5adb

[jrose-apple]

And, merged! Thank you, Mani!

[maniramezan]

Amazing, very excited : ) Thanks for your help during this and look forward to bug you more on other tickets