phatblat / swiftgenwmo

An example of the linker blowing up when WMO is enabled

SwiftGenWMO

An example of the linker blowing up when WMO is enabled.

This project uses SwiftGen to generate enums (UIColor-Name.swift) for a list of color values. It compiles just fine when the SWIFT_OPTIMIZATION_LEVEL is set to "None [-Onone]" or "Fast [-O]". However it breaks with the following ugly messages when Whole Module Optimization (WMO) is enabled (SwiftGenWMO (Release) scheme).

Ld /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/i386/SwiftGenWMO normal i386
    cd /Users/ben/dev/ios/SwiftGenWMO
    export IPHONEOS_DEPLOYMENT_TARGET=9.1
    export PATH="/Applications/Xcode7.1.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode7.1.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Applications/Xcode7.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode7.1.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.1.sdk -L/Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Products/Release-iphonesimulator -F/Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Products/Release-iphonesimulator -filelist /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/i386/SwiftGenWMO.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -mios-simulator-version-min=9.1 -Xlinker -objc_abi_version -Xlinker 2 -L/Applications/Xcode7.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -add_ast_path -Xlinker /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/i386/SwiftGenWMO.swiftmodule -Xlinker -dependency_info -Xlinker /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/i386/SwiftGenWMO_dependency_info.dat -o /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/i386/SwiftGenWMO

Undefined symbols for architecture i386:
  "direct type metadata for ext.SwiftGenWMO.__ObjC.UIColor.Name", referenced from:
      _globalinit_33_9DB38CA9AF8247CBBD097F938D9B20B4_func0 in ViewController.o
      generic specialization <ext.SwiftGenWMO.__ObjC.UIColor.Name with ext.SwiftGenWMO.__ObjC.UIColor.Name : Swift.Hashable in SwiftGenWMO, Swift.UInt32> of static Swift._VariantDictionaryStorage.maybeGetFromCocoaStorage <A, B where A: Swift.Hashable> (Swift._VariantDictionaryStorage<A, B>.Type)(Swift._CocoaDictionaryStorage, forKey : A) -> B? in ViewController.o
      function signature specialization <Arg[1] = Dead> of generic specialization <(ext.SwiftGenWMO.__ObjC.UIColor.Name, Swift.UInt32)> of static Swift.Array._allocateBufferUninitialized <A> ([A].Type)(Swift.Int) -> Swift._ArrayBuffer<A> in ViewController.o
      function signature specialization <Arg[0] = Owned To Guaranteed, Arg[1] = Dead> of generic specialization <ext.SwiftGenWMO.__ObjC.UIColor.Name with ext.SwiftGenWMO.__ObjC.UIColor.Name : Swift.Hashable in SwiftGenWMO, Swift.UInt32> of static Swift._NativeDictionaryStorage.fromArray <A, B where A: Swift.Hashable> (Swift._NativeDictionaryStorage<A, B>.Type)([(A, B)]) -> Swift._NativeDictionaryStorage<A, B> in ViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Ld /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/x86_64/SwiftGenWMO normal x86_64
    cd /Users/ben/dev/ios/SwiftGenWMO
    export IPHONEOS_DEPLOYMENT_TARGET=9.1
    export PATH="/Applications/Xcode7.1.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode7.1.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Applications/Xcode7.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode7.1.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.1.sdk -L/Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Products/Release-iphonesimulator -F/Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Products/Release-iphonesimulator -filelist /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/x86_64/SwiftGenWMO.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -mios-simulator-version-min=9.1 -Xlinker -objc_abi_version -Xlinker 2 -L/Applications/Xcode7.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -add_ast_path -Xlinker /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/x86_64/SwiftGenWMO.swiftmodule -Xlinker -dependency_info -Xlinker /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/x86_64/SwiftGenWMO_dependency_info.dat -o /Users/ben/Library/Developer/Xcode/DerivedData/SwiftGenWMO-cpguaisqqgbnnhabwlwdrmjpjnmy/Build/Intermediates/SwiftGenWMO.build/Release-iphonesimulator/SwiftGenWMO.build/Objects-normal/x86_64/SwiftGenWMO

Undefined symbols for architecture x86_64:
  "direct type metadata for ext.SwiftGenWMO.__ObjC.UIColor.Name", referenced from:
      _globalinit_33_9DB38CA9AF8247CBBD097F938D9B20B4_func0 in ViewController.o
      generic specialization <ext.SwiftGenWMO.__ObjC.UIColor.Name with ext.SwiftGenWMO.__ObjC.UIColor.Name : Swift.Hashable in SwiftGenWMO, Swift.UInt32> of static Swift._VariantDictionaryStorage.maybeGetFromCocoaStorage <A, B where A: Swift.Hashable> (Swift._VariantDictionaryStorage<A, B>.Type)(Swift._CocoaDictionaryStorage, forKey : A) -> B? in ViewController.o
      function signature specialization <Arg[1] = Dead> of generic specialization <(ext.SwiftGenWMO.__ObjC.UIColor.Name, Swift.UInt32)> of static Swift.Array._allocateBufferUninitialized <A> ([A].Type)(Swift.Int) -> Swift._ArrayBuffer<A> in ViewController.o
      function signature specialization <Arg[0] = Owned To Guaranteed, Arg[1] = Dead> of generic specialization <ext.SwiftGenWMO.__ObjC.UIColor.Name with ext.SwiftGenWMO.__ObjC.UIColor.Name : Swift.Hashable in SwiftGenWMO, Swift.UInt32> of static Swift._NativeDictionaryStorage.fromArray <A, B where A: Swift.Hashable> (Swift._NativeDictionaryStorage<A, B>.Type)([(A, B)]) -> Swift._NativeDictionaryStorage<A, B> in ViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Xcode Versions

The following versions of Xcode have all been tested with the project and have this issue with WMO builds:

• 7.1 (7B91b)
• 7.1.1 (7B1005)
• 7.2 beta 3 (7C62)

License

This repo is licensed under the MIT License. See the LICENSE file for rights and limitations.