[SR-15720] Moving extension with custom decoding to separate file causes compiler to crash

[swift-ci]

Previous ID	SR-15720
Radar	None
Original Reporter	trey (JIRA User)
Type	Bug

Attachment: Download

Environment

Xcode 13.2.1

Swift 5

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug
Assignee	None
Priority	Medium

md5: d43e58634755f7d39144b112edb8d1b1

Issue Description:

When the extensions are in the same file as the main declaration, the attached project builds successfully. When the extensions are moved to a separate file, the compiler crashes with:

Global is external, but doesn't have external or weak linkage!
%swift.type_descriptor* @"$s4test11EnvironmentV3MSLV10CodingKeys33_B088AB77345056538C29A4CD9A5C0748LLOMn"
Global is external, but doesn't have external or weak linkage!
%swift.type* @"$s4test11EnvironmentV3MSLV10CodingKeys33_B088AB77345056538C29A4CD9A5C0748LLON"
<unknown>:0: error: fatal error encountered during compilation; please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project
<unknown>:0: note: Broken module found, compilation aborted!
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project and the crash backtrace.
Stack dump:
0.  Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c "/Users/paucoin/Library/Autosave Information/test/Shared/ContentView.swift" -primary-file "/Users/paucoin/Library/Autosave Information/test/Environment.swift" "/Users/paucoin/Library/Autosave Information/test/Shared/testApp.swift" "/Users/paucoin/Library/Autosave Information/test/EnvironmentCoding.swift" -emit-dependencies-path "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/Objects-normal/x86_64/Environment.d" -emit-reference-dependencies-path "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/Objects-normal/x86_64/Environment.swiftdeps" -serialize-diagnostics-path "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/Objects-normal/x86_64/Environment.dia" -target x86_64-apple-ios15.2-simulator -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator15.2.sdk -I /Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Products/Debug-iphonesimulator -F /Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Products/Debug-iphonesimulator -no-color-diagnostics -enable-testing -g -module-cache-path /Users/paucoin/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -emit-localized-strings -emit-localized-strings-path "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/Objects-normal/x86_64" -swift-version 5 -enforce-exclusivity=checked -Onone -D DEBUG -serialize-debugging-options -Xcc -working-directory -Xcc "/Users/paucoin/Library/Autosave Information/test" -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -enable-anonymous-context-mangled-names -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/swift-overrides.hmap" -Xcc -iquote -Xcc "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/test-generated-files.hmap" -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/test-own-target-headers.hmap" -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/test-all-target-headers.hmap" -Xcc -iquote -Xcc "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/test-project-headers.hmap" -Xcc -I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Products/Debug-iphonesimulator/include -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/DerivedSources-normal/x86_64" -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/DerivedSources/x86_64" -Xcc "-I/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/DerivedSources" -Xcc -DDEBUG=1 -module-name test -target-sdk-version 15.2.0 -o "/Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test (iOS).build/Objects-normal/x86_64/Environment.o" -index-store-path /Users/paucoin/Library/Developer/Xcode/DerivedData/test-eyspamhdemkxhkbvhwxcoitxrpxo/Index/DataStore -index-system-modules
1.  Apple Swift version 5.5.2 (swiftlang-1300.0.47.5 clang-1300.0.29.30)
2.  
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010a6cec27 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 39
1  swift-frontend           0x000000010a6cdbb8 llvm::sys::RunSignalHandlers() + 248
2  swift-frontend           0x000000010a6cf236 SignalHandler(int) + 278
3  libsystem_platform.dylib 0x00007fff203e8d7d _sigtramp + 29
4  libsystem_platform.dylib 0x00007ffeea500660 _sigtramp + 18446744072804727040
5  libsystem_c.dylib        0x00007fff202f8406 abort + 125
6  swift-frontend           0x00000001057e0502 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*)::$_2::__invoke(void*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) + 978
7  swift-frontend           0x000000010a61869e llvm::report_fatal_error(llvm::Twine const&, bool) + 286
8  swift-frontend           0x000000010a61857b llvm::report_fatal_error(char const*, bool) + 43
9  swift-frontend           0x000000010a5af0de (anonymous namespace)::VerifierLegacyPass::doFinalization(llvm::Module&) + 174
10 swift-frontend           0x000000010a54fdd2 llvm::FPPassManager::doFinalization(llvm::Module&) + 66
11 swift-frontend           0x000000010a548570 llvm::legacy::FunctionPassManagerImpl::doFinalization(llvm::Module&) + 80
12 swift-frontend           0x0000000105cd5ba1 swift::performLLVMOptimizations(swift::IRGenOptions const&, llvm::Module*, llvm::TargetMachine*) + 1649
13 swift-frontend           0x0000000105cd69c7 swift::performLLVM(swift::IRGenOptions const&, swift::DiagnosticEngine&, llvm::sys::SmartMutex<false>*, llvm::GlobalVariable*, llvm::Module*, llvm::TargetMachine*, llvm::StringRef, swift::UnifiedStatsReporter*) + 2055
14 swift-frontend           0x00000001057eba9d performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 3581
15 swift-frontend           0x00000001057dd346 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 13830
16 swift-frontend           0x000000010571db08 main + 1032
17 libdyld.dylib            0x00007fff203bef3d start + 1
18 libdyld.dylib            0x000000000000004e start + 18446603339975364882
Command SwiftDriverJob-Compile failed with a nonzero exit code