Fix Redefinition of module error in Xcode ≧ 8.3, Take 2

[vkedwardli]

Second attempt to fix this bug (first failed attempt:#465)

Using dynamic generated modulemap now to avoid the Xcode bug, according to Xcode 8.3 release notes:

When building a framework that has module maps in both the source and the install directories that define the same module, the compiler will show a redefinition message. (28638816)

Reference:
ResearchKit/ResearchKit#922
grpc/grpc#10355

Should can fix the error mentioned by @rhishikeshj in #361 (comment)

[shams-ahmed]

Is this fix ready to be merged?

[vkedwardli]

@shams-ahmed My PR supports the original Xcode project and cocoapods generated project, I think I don't have anything to add, do inform me if you find any bug, thanks

[daltoniam]

This looks cool, Thanks! It would probably be best to test it with all 3 package managers (Swift Package Manager, CocoaPods, and Carthage). It is quite a process to get them to play nicely with the different dependencies (the commonCrypto and zlib) and It would be great if this removes that warning and simplifies all that building a bit 😄.

[vkedwardli]

Sure thing, will double check on the package manager and cart later when I'm free

[bayareahank]

We ran into similar Starscream Carthage module redefinition build errors in ParseLiveQuery:
parse-community/ParseLiveQuery-iOS-OSX#159
Hope this fix can solve the problem.

[vkedwardli]

@bayareahank may be you could help on verifying on Carthage to speed up accepting

[bayareahank]

Sure.

Disclaimer that I only used Carthage to pull directly from github before, if there is some pointers as to how to build with pull request, that would be helpful.

[vkedwardli]

@bayareahank try it from my branch
git "https://github.com/vkedwardli/Starscream.git" "fix-module-redefinition"

[bayareahank]

I tried the change in ParseLiveQuery, the app build still runs into errors, though the detailed error message changed a bit from previous one.

Previously it complains "redefinition of module 'SSCZLib' and module 'SSCommonCrypto',
thus could not build Objective-C module 'Starscream' "
parse-community/ParseLiveQuery-iOS-OSX#159

This time it fails to build Object-C module 'SSCZlib'. The detailed error message is:
~/Library/Caches/org.carthage.CarthageKit/DerivedData/9.3_9E145/Starscream/897f51388f6b1504f1093f2ca7dcd302e2b3128e/Build/Products/Release-iphonesimulator/StarscreamModuleMap/module.modulemap:6:8: error: import of shadowed module 'SSCommonCrypto'
module SSCommonCrypto [system] {
^
~/tmp/liveStarstream/Carthage/Checkouts/ParseLiveQuery-iOS-OSX/Carthage/Checkouts/Starscream/zlib/module.modulemap:6:8: note: previous definition is here
module SSCommonCrypto [system] {
^
~/tmp/liveStarstream/Carthage/Checkouts/ParseLiveQuery-iOS-OSX/Carthage/Checkouts/Starscream/zlib/include.h:2:10: note: submodule of top-level module 'SSCommonCrypto' implicitly imported here
#include <CommonCrypto/CommonCrypto.h>
^
:0: error: could not build Objective-C module 'SSCZLib'

The steps I took are:

1. Forked ParseLiveQuery-iOS-OSX, modify its Cartfile to point to "vkedwardli/Starscream" "fix-module-redefinition"
2. Changed Cartfile of sample app to:
   github "bayareahank/ParseLiveQuery-iOS-OSX" "master"
3. Carthage built fine.
4. Added ParseLiveQuery framework to the sample iOS app.
5. Build the app itself, it failed with error messages listed above.

BTW, my set up is Xcode 9.3, Swift 4.1, Carthage 0.29.0, macOS 10.13.4 High Sierra.

Cartfile:
github "bayareahank/ParseLiveQuery-iOS-OSX" "master"

Cartfile.resolved:

github "BoltsFramework/Bolts-ObjC" "1.9.0"
github "BoltsFramework/Bolts-Swift" "e9baa72d04521c3b25ef4fa6fef12b340953ee02"
github "ParsePlatform/Parse-SDK-iOS-OSX" "1.17.1"
github "bayareahank/ParseLiveQuery-iOS-OSX" "2.4.0"
github "vkedwardli/Starscream" "fix-module-redefinition"
github "facebook/facebook-ios-sdk" "sdk-version-4.32.0"

[bayareahank]

Tried the hack in #445 by Bersaelor, -- manually remove the SSCZLib and SSCommonCrypto module definitions from Carthage/Checkout/Starscream/zlib/module.modulemap file after Carthage build, that solved the problem for me. FYI.

[vkedwardli]

Thanks for the input @bayareahank, I have verified that it is working on Carthage also.

@daltoniam By using SPM's swift package generate-xcodeproj with your master branch, the generated xcodeproj cannot locate the SSCZLib/SSCommonCrypto anyways, while using swift build, both the master branch and my pull request are building successfully (since they are both using your zlib-spm and common-crypto-spm, nothing related to my script)

What is the intended usage for SPM in this project? I thought SPM doesn't support iOS officially?
Thanks

[vkedwardli]

The fix in #520 is more elegant, closing this one.
Would be great if @daltoniam can spend some time to review and accept #520 😁