[SR-4286] [Blocker] unhandled param context

[dabrahams]

Previous ID	SR-4286
Radar	None
Original Reporter	@dabrahams
Type	Bug
Status	Closed
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, CompilerCrash
Assignee	@dabrahams
Priority	Medium

md5: 74775e111704e9fe2799b4a67cdd9479

Issue Description:

$ git fetch https://github.com/dabrahams/swift refs/bugs/unhandled-param-context:BUG && git checkout BUG

/Users/Shared/dabrahams/s/swift/utils/build-script --distcc --skip-build-ios-device --skip-build-tvos-device --debug-swift-stdlib --skip-build-benchmarks --release --swift-stdlib-assertions --swift-stdlib-build-type=Debug --

+ mkdir -p /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert
+ env HOST_VARIABLE_macosx_x86_64__SWIFT_BENCHMARK_TARGETS=swift-benchmark-macosx-x86_64 HOST_VARIABLE_macosx_x86_64__SWIFT_RUN_BENCHMARK_TARGETS=check-swift-benchmark-macosx-x86_64 'HOST_VARIABLE_macosx_x86_64__SWIFT_SDKS=IOS IOS_SIMULATOR OSX TVOS TVOS_SIMULATOR WATCHOS WATCHOS_SIMULATOR' HOST_VARIABLE_macosx_x86_64__SWIFT_STDLIB_TARGETS=swift-test-stdlib-macosx-x86_64 HOST_VARIABLE_macosx_x86_64__SWIFT_TEST_TARGETS= caffeinate /Users/Shared/dabrahams/s/swift/utils/build-script-impl --workspace /Users/Shared/dabrahams/s --build-dir /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert --install-prefix /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr --host-target macosx-x86_64 --stdlib-deployment-targets 'macosx-x86_64 iphonesimulator-i386 iphonesimulator-x86_64 appletvsimulator-x86_64 watchsimulator-i386 iphoneos-armv7 iphoneos-armv7s iphoneos-arm64 appletvos-arm64 watchos-armv7k' --host-cc /Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang --host-cxx /Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ --darwin-xcrun-toolchain default --darwin-deployment-version-osx=10.9 --darwin-deployment-version-ios=7.0 --darwin-deployment-version-tvos=9.0 --darwin-deployment-version-watchos=2.0 --cmake /Users/dave/brew/bin/cmake --cmark-build-type Release --llvm-build-type Release --swift-build-type Release --swift-stdlib-build-type Debug --lldb-build-type Release --foundation-build-type Release --libdispatch-build-type Release --libicu-build-type Release --xctest-build-type Release --swiftpm-build-type Release --swift-enable-assertions true --swift-stdlib-enable-assertions true --swift-analyze-code-coverage false --cmake-generator Ninja --build-jobs 8 '--common-cmake-options=-G Ninja -DCMAKE_C_COMPILER:PATH=/Users/dave/brew/bin/distcc -DCMAKE_C_COMPILER_ARG1=/Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -DCMAKE_CXX_COMPILER:PATH=/Users/dave/brew/bin/distcc -DCMAKE_CXX_COMPILER_ARG1=/Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -DCMAKE_MAKE_PROGRAM=/Users/dave/brew/bin/ninja' --build-args=-j20 --cmark-cmake-options= '--llvm-cmake-options=-DLLVM_ENABLE_ASSERTIONS=TRUE -DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;PowerPC;SystemZ' '--swift-cmake-options=-DSWIFT_STDLIB_ENABLE_SIL_OWNERSHIP=FALSE -DCMAKE_EXPORT_COMPILE_COMMANDS=TRUE -DSWIFT_FORCE_OPTIMIZED_TYPECHECKER=FALSE' --build-stdlib-deployment-targets all --ninja-bin=/Users/dave/brew/bin/ninja --distcc --distcc-pump=/Users/dave/brew/bin/pump --skip-build-benchmarks --skip-build-foundation --skip-build-xctest --skip-build-lldb --skip-build-llbuild --skip-build-libdispatch --skip-build-libicu --skip-build-swiftpm --skip-build-playgroundlogger --skip-build-playgroundsupport --build-swift-dynamic-stdlib --build-swift-dynamic-sdk-overlay --skip-build-ios-device --skip-build-ios-simulator --skip-build-tvos-device --skip-build-tvos-simulator --skip-build-watchos-device --skip-build-watchos-simulator --skip-build-android --skip-test-swift --skip-test-cmark --skip-test-lldb --skip-test-llbuild --skip-test-swiftpm --skip-test-xctest --skip-test-foundation --skip-test-libdispatch --skip-test-libicu --skip-test-playgroundlogger --skip-test-playgroundsupport --skip-test-linux --skip-test-freebsd --skip-test-cygwin --skip-test-osx --skip-test-ios-host --skip-test-ios-simulator --skip-test-tvos-host --skip-test-tvos-simulator --skip-test-watchos-host --skip-test-watchos-simulator --skip-test-android-host --skip-test-benchmarks --skip-test-optimized --android-deploy-device-path /data/local/tmp --toolchain-prefix /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain --host-lipo /Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/lipo --host-libtool /Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool --swift-stdlib-build-type=Debug --llvm-lit-args=-sv
Building the standard library for: swift-test-stdlib-macosx-x86_64
cmark: using standard linker
+ /Users/dave/brew/bin/pump /Users/dave/brew/bin/cmake --build /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/cmark-macosx-x86_64 -- -j20 all
__________Using distcc-pump from /Users/dave/brew/bin/../Cellar/distcc-swift/r796/bin
__________Using        2 distcc servers in pump mode
ninja: no work to do.
__________Shutting down distcc-pump include server
llvm: using standard linker
symlinking the system headers (/Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../../usr/include/c++) into the local clang build directory (/Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/llvm-macosx-x86_64/include).
+ ln -s -f /Applications/Xcode-8W109m.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../../usr/include/c++ /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/llvm-macosx-x86_64/include
+ /Users/dave/brew/bin/pump /Users/dave/brew/bin/cmake --build /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/llvm-macosx-x86_64 -- -j20 all
__________Using distcc-pump from /Users/dave/brew/bin/../Cellar/distcc-swift/r796/bin
__________Using        2 distcc servers in pump mode
ninja: no work to do.
__________Shutting down distcc-pump include server
swift: using standard linker
+ /Users/dave/brew/bin/pump /Users/dave/brew/bin/cmake --build /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64 -- -j20 all swift-test-stdlib-macosx-x86_64
__________Using distcc-pump from /Users/dave/brew/bin/../Cellar/distcc-swift/r796/bin
__________Using        2 distcc servers in pump mode
[1/165] Generating UnsafeBufferPointer.swift from UnsafeBufferPointer.swift.gyb with ptr size = 8
[2/165] Generating /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftmodule
FAILED: lib/swift/macosx/x86_64/Swift.swiftmodule lib/swift/macosx/x86_64/Swift.swiftdoc 
cd /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/stdlib/public/core && /Users/dave/brew/Cellar/cmake/3.7.2/bin/cmake -E remove -f /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftmodule && /usr/bin/python /Users/Shared/dabrahams/s/swift/utils/line-directive @/Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/stdlib/public/core/VEZn4.txt -- /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./bin/swiftc -emit-module -o /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftmodule -sdk /Applications/Xcode-8W109m.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -target x86_64-apple-macosx10.9 -resource-dir /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift -F /Applications/Xcode-8W109m.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/../../../Developer/Library/Frameworks -Onone -g -D INTERNAL_CHECKS_ENABLED -I /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64 -module-cache-path /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./module-cache -no-link-objc-runtime -nostdimport -parse-stdlib -module-name Swift -Xfrontend -group-info-path -Xfrontend /Users/Shared/dabrahams/s/swift/stdlib/public/core/GroupInfo.json -Xfrontend -sil-serialize-all -module-link-name swiftCore -force-single-frontend-invocation -Xcc -D__SWIFT_CURRENT_DYLIB=swiftCore -parse-as-library @/Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/stdlib/public/core/VEZn4.txt
/Users/Shared/dabrahams/s/swift/stdlib/public/core/SequenceWrapper.swift:23:29: warning: redundant conformance constraint 'Self.Iterator': 'IteratorProtocol'
  associatedtype Iterator : IteratorProtocol = Base.Iterator
                            ^
/Users/Shared/dabrahams/s/swift/stdlib/public/core/SequenceWrapper.swift:21:29: note: conformance constraint 'Self.Iterator': 'IteratorProtocol' implied here
protocol _SequenceWrapper : Sequence {
                            ^
/Users/Shared/dabrahams/s/swift/stdlib/public/core/AnyUnicode.swift:221:30: warning: redundant conformance constraint 'Self.CodeUnits.Iterator.Element': 'UnsignedInteger'
  CodeUnits.Iterator.Element : UnsignedInteger,
                             ^
/Users/Shared/dabrahams/s/swift/stdlib/public/core/AnyUnicode.swift:222:30: note: conformance constraint 'Self.CodeUnits.Iterator.Element': 'UnsignedInteger' implied here
  CodeUnits.Iterator.Element == UTF16.CodeUnit,
                             ^
/Users/Shared/dabrahams/s/swift/stdlib/public/core/AnyUnicode.swift:169:25: warning: redundant conformance constraint 'Self.CodeUnits.SubSequence': 'Collection'
  CodeUnits.SubSequence : Collection, 
                        ^
unhandled param context
UNREACHABLE executed at /Users/Shared/dabrahams/s/swift/lib/AST/ASTMangler.cpp:374!
0  swift                    0x0000000104aecd48 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1  swift                    0x0000000104aed3f6 SignalHandler(int) + 454
2  libsystem_platform.dylib 0x00007fffa9191bba _sigtramp + 26
3  swift                    0x0000000104be2d47 clang::StringLiteral::outputString(llvm::raw_ostream&) const::Hex + 538551
4  libsystem_c.dylib        0x00007fffa9018420 abort + 129
5  swift                    0x0000000104a8a587 llvm::llvm_unreachable_internal(char const*, char const*, unsigned int) + 471
6  swift                    0x00000001026e07c0 swift::NewMangling::ASTMangler::mangleAccessorEntityAsUSR(swift::AccessorKind, swift::AddressorKind, swift::ValueDecl const*, llvm::StringRef) + 0
7  swift                    0x00000001026dc7bc swift::NewMangling::ASTMangler::appendEntity(swift::ValueDecl const*, llvm::StringRef, bool) + 76
8  swift                    0x00000001026e0029 swift::NewMangling::ASTMangler::mangleDeclAsUSR(swift::ValueDecl*, llvm::StringRef) + 377
9  swift                    0x00000001027d2b5e swift::ide::printDeclUSR(swift::ValueDecl const*, llvm::raw_ostream&) + 1310
10 swift                    0x00000001023ded33 writeDeclCommentTable(llvm::BCRecordLayout<1u, llvm::BCVBR<16u>, llvm::BCBlob> const&, swift::SourceFile const*, swift::ModuleDecl const*, DeclGroupNameContext&)::DeclCommentTableWriter::walkToDeclPre(swift::Decl*) + 499
11 swift                    0x0000000102715d7c (anonymous namespace)::Traversal::doIt(swift::Decl*) + 204
12 swift                    0x00000001027197ff (anonymous namespace)::Traversal::visitParameterList(swift::ParameterList*) + 95
13 swift                    0x00000001027163c3 (anonymous namespace)::Traversal::doIt(swift::Decl*) + 1811
14 swift                    0x000000010271602e (anonymous namespace)::Traversal::doIt(swift::Decl*) + 894
15 swift                    0x0000000102715c9b swift::Decl::walk(swift::ASTWalker&) + 27
16 swift                    0x000000010279323a swift::SourceFile::walk(swift::ASTWalker&) + 170
17 swift                    0x00000001023d7c59 swift::serialization::Serializer::writeDocToStream(llvm::raw_ostream&, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, llvm::StringRef, swift::ASTContext&) + 793
18 swift                    0x00000001024068cc void llvm::function_ref<void (llvm::raw_ostream&)>::callback_fn<swift::serialize(llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::SerializationOptions const&, swift::SILModule const*)::$_6>(long, llvm::raw_ostream&) + 204
19 swift                    0x00000001023d8a7b withOutputFile(swift::ASTContext&, llvm::StringRef, llvm::function_ref<void (llvm::raw_ostream&)>) + 395
20 swift                    0x00000001023d88c0 swift::serialize(llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::SerializationOptions const&, swift::SILModule const*) + 304
21 swift                    0x00000001017fe393 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 14627
22 swift                    0x00000001017b92e0 main + 3312
23 libdyld.dylib            0x00007fffa8f84255 start + 1
Stack dump:
0.  Program arguments: /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/bin/swift -frontend -emit-module -filelist /var/folders/8v/9769m3ps7ds7h9pg23lzcls00000gn/T/sources-c8fe9a -disable-objc-attr-requires-foundation-module -target x86_64-apple-macosx10.9 -enable-objc-interop -sdk /Applications/Xcode-8W109m.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -I /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64 -F /Applications/Xcode-8W109m.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/../../../Developer/Library/Frameworks -g -module-cache-path /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./module-cache -module-link-name swiftCore -nostdimport -parse-stdlib -resource-dir /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift -D INTERNAL_CHECKS_ENABLED -group-info-path /Users/Shared/dabrahams/s/swift/stdlib/public/core/GroupInfo.json -sil-serialize-all -Xcc -D__SWIFT_CURRENT_DYLIB=swiftCore -emit-module-doc-path /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftdoc -Onone -parse-as-library -module-name Swift -o /Users/Shared/dabrahams/s/build/Ninja-ReleaseAssert+stdlib-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftmodule 
1.  While walking into decl extension of _Indexable at /Users/Shared/dabrahams/s/swift/stdlib/public/core/Range.swift.gyb:719:1

Other hashes

clang 1381e50988 Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
cmark d875488 Merge pull request #4 from llvm-beanz/generate-cmark-exports
compiler-rt 572336a0b Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
llbuild c8a84b3 Merge pull request #130 from hughbe/mkdir-windows
lldb 9ca9758f9 Merge pull request #149 from bitjammer/swift-typealias-equal-sourceloc
llvm e69035ecc18 Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
Traceback (most recent call last):

[dabrahams]

Amazingly, this issue is suppressed by naming the unnamed parameters shown here (I used x as the name):

extension _Indexable {
  public subscript(_: UnboundedRange) -> SubSequence {
    return self[startIndex..<endIndex]
  }
}

extension _MutableIndexable {
  public subscript(_: UnboundedRange) -> SubSequence {
    get {
      return self[startIndex...]
    }
    set {
      self[startIndex...] = newValue
    }
  }
}

[dabrahams]

I believe this bug is now a blocker for me. I have a newer reproducer:

$ git fetch https://github.com/dabrahams/swift refs/bugs/SR-4286:BUG && git checkout BUG

which crashes like this when you build the standard library:

unhandled param context
UNREACHABLE executed at /Users/Shared/dabrahams/s/swift/lib/AST/ASTMangler.cpp:397!
0  swift                    0x0000000112dd5d5c llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 60
1  swift                    0x0000000112dd62d9 PrintStackTraceSignalHandler(void*) + 25
2  swift                    0x0000000112dd1fb9 llvm::sys::RunSignalHandlers() + 425
3  swift                    0x0000000112dd6772 SignalHandler(int) + 354
4  libsystem_platform.dylib 0x00007fffb453ab3a _sigtramp + 26
5  libsystem_platform.dylib 0x00007fff53cd30e0 _sigtramp + 2675541440
6  libsystem_c.dylib        0x00007fffb43bf420 abort + 129
7  swift                    0x0000000112ccf430 LLVMInstallFatalErrorHandler + 0
8  swift                    0x000000010e298306 getUnnamedParamIndex(swift::Decl const*) + 198
9  swift                    0x000000010e297cc4 swift::Mangle::ASTMangler::appendDeclName(swift::ValueDecl const*) + 1780
10 swift                    0x000000010e2912ea swift::Mangle::ASTMangler::appendEntity(swift::ValueDecl const*, llvm::StringRef, bool) + 106
11 swift                    0x000000010e28fbd6 swift::Mangle::ASTMangler::appendEntity(swift::ValueDecl const*) + 646
12 swift                    0x000000010e297599 swift::Mangle::ASTMangler::mangleDeclAsUSR(swift::ValueDecl*, llvm::StringRef) + 329
13 swift                    0x000000010e5cfc5a swift::ide::printDeclUSR(swift::ValueDecl const*, llvm::raw_ostream&) + 1050
14 swift                    0x000000010da3c968 writeDeclCommentTable(llvm::BCRecordLayout<1u, llvm::BCVBR<16u>, llvm::BCBlob> const&, swift::SourceFile const*, swift::ModuleDecl const*, DeclGroupNameContext&)::DeclCommentTableWriter::walkToDeclPre(swift::Decl*) + 312
15 swift                    0x000000010e34d99c (anonymous namespace)::Traversal::doIt(swift::Decl*) + 92
16 swift                    0x000000010e351807 (anonymous namespace)::Traversal::visitParameterList(swift::ParameterList*) + 135
17 swift                    0x000000010e351768 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::ParameterList*) + 40
18 swift                    0x000000010e351558 (anonymous namespace)::Traversal::visit(swift::ParameterList*) + 40
19 swift                    0x000000010e35769d (anonymous namespace)::Traversal::visitSubscriptDecl(swift::SubscriptDecl*) + 45
20 swift                    0x000000010e356d2f swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Decl*) + 671
21 swift                    0x000000010e3569a6 (anonymous namespace)::Traversal::visit(swift::Decl*) + 70
22 swift                    0x000000010e34d9ba (anonymous namespace)::Traversal::doIt(swift::Decl*) + 122
23 swift                    0x000000010e357dc5 (anonymous namespace)::Traversal::visitNominalTypeDecl(swift::NominalTypeDecl*) + 997
24 swift                    0x000000010e3575d8 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visitProtocolDecl(swift::ProtocolDecl*) + 40
25 swift                    0x000000010e356cbb swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Decl*) + 555
26 swift                    0x000000010e3569a6 (anonymous namespace)::Traversal::visit(swift::Decl*) + 70
27 swift                    0x000000010e34d9ba (anonymous namespace)::Traversal::doIt(swift::Decl*) + 122
28 swift                    0x000000010e34d930 swift::Decl::walk(swift::ASTWalker&) + 64
29 swift                    0x000000010e513fad swift::SourceFile::walk(swift::ASTWalker&) + 525
30 swift                    0x000000010da20488 writeDeclCommentTable(llvm::BCRecordLayout<1u, llvm::BCVBR<16u>, llvm::BCBlob> const&, swift::SourceFile const*, swift::ModuleDecl const*, DeclGroupNameContext&) + 392
31 swift                    0x000000010da20202 swift::serialization::Serializer::writeDocToStream(llvm::raw_ostream&, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, llvm::StringRef, swift::ASTContext&) + 322
32 swift                    0x000000010da99142 swift::serialize(llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::SerializationOptions const&, swift::SILModule const*)::$_6::operator()(llvm::raw_ostream&) const + 274
33 swift                    0x000000010da99025 void llvm::function_ref<void (llvm::raw_ostream&)>::callback_fn<swift::serialize(llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::SerializationOptions const&, swift::SILModule const*)::$_6>(long, llvm::raw_ostream&) + 37
34 swift                    0x000000010da40f27 llvm::function_ref<void (llvm::raw_ostream&)>::operator()(llvm::raw_ostream&) const + 55
35 swift                    0x000000010da219a2 withOutputFile(swift::ASTContext&, llvm::StringRef, llvm::function_ref<void (llvm::raw_ostream&)>) + 2690
36 swift                    0x000000010da20f0d swift::serialize(llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::SerializationOptions const&, swift::SILModule const*) + 829
37 swift                    0x000000010bffc8ba performCompile(std::__1::unique_ptr<swift::CompilerInstance, std::__1::default_delete<swift::CompilerInstance> >&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*) + 20858
38 swift                    0x000000010bff6a0f swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 13279
39 swift                    0x000000010bf2cae9 main + 4809
40 libdyld.dylib            0x00007fffb432b235 start + 1
Stack dump:
0.  Program arguments: /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/bin/swift -frontend -emit-module -filelist /var/folders/k9/nzq6k4f57xb5vw8wrgk_7cvh0000gn/T/sources-2dadc9 -disable-objc-attr-requires-foundation-module -target x86_64-apple-macosx10.9 -enable-objc-interop -sdk /Applications/Xcode-8E161.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -I /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64 -F /Applications/Xcode-8E161.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/../../../Developer/Library/Frameworks -g -module-cache-path /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/./module-cache -module-link-name swiftCore -nostdimport -parse-stdlib -resource-dir /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/./lib/swift -D INTERNAL_CHECKS_ENABLED -group-info-path /Users/Shared/dabrahams/s/swift/stdlib/public/core/GroupInfo.json -sil-serialize-all -Xcc -D__SWIFT_CURRENT_DYLIB=swiftCore -emit-module-doc-path /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftdoc -Onone -parse-as-library -module-name Swift -o /Users/Shared/dabrahams/s/build/Ninja-DebugAssert/swift-macosx-x86_64/./lib/swift/macosx/x86_64/Swift.swiftmodule
1.  While walking into decl 'AnyUInt16UnicodeView_' at /Users/Shared/dabrahams/s/swift/stdlib/public/core/AnyUnicode.swift.gyb:401:8

you can suppress the assertion by naming the subscript parameter in the protocol declaration (_ x:… instead of _:…), but then compilation just crashes unceremoniously.

Other hashes:

clang                              8f252f88d6 Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
cmark                              d875488 Merge pull request #​4 from llvm-beanz/generate-cmark-exports
compiler-rt                        657d67d7d Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
llbuild                            b696a76 Merge pull request #​134 from hughbe/wsl-expected
lldb                               9ca9758f9 Merge pull request #​149 from bitjammer/swift-typealias-equal-sourceloc
llvm                               f5eaf796665 Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
ninja                              0b0374e Merge pull request #​1255 from tchajed/bind-localhost
swift                              74504d0f76f [stdlib] StringProto: rangeReplacement/uniqueness checking actually work
swift-corelibs-foundation          a6e77b4 Merge pull request #​924 from ianpartridge/nsregularexpression
swift-corelibs-libdispatch         d137aa4 Makes the DispatchIO initializer that accepts a path failable, reflecting the fact that a relative or non-existent path is invalid.
swift-corelibs-xctest              50cc074 XCTestAssertNoThrow (#184)
swift-integration-tests            8ae3586 Merge pull request #​18 from apple/disable-lldb-test
swift-xcode-playground-support     9e980f2 Temporary disable test to get the incremental bot blue again
swiftpm                            d72c4f25 Merge pull request #​1038 from heckj/SR-4327

[slavapestov]

#8335

[dabrahams]

@slavapestov Thanks; did you want to assign to me for closure?

[slavapestov]

Re-assigning to you for closure, continuation and macro.

[dabrahams]

Thanks, Slava!