Assertion failure in importParameterType when importing getKnownFolderLocations on Xcode 16.2

[hamishknight]

This hits an assertion in the Clang importer on Xcode 16.2 when building for iOS:

import FileProvider

func foo(_ x: AnyObject) {
  _ = x.getKnownFolderLocations
}

Assertion failed: (clangEnum.value() ->getIntegerType() ->getCanonicalTypeInternal() == typedefType->getCanonicalTypeInternal()), function importParameterType, file ImportType.cpp, line 2478.
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.      Program arguments: /Users/hamish/src/swift-dev/build/Release/swift-macosx-arm64/bin/swift-frontend -typecheck /Users/hamish/src/swift-test-arena/main.swift -sdk /Users/hamish/src/iPhoneOS.sdk -debug-diagnostic-names -diagnostic-style=llvm -target arm64-apple-ios16.0
1.      Swift version 6.2-dev (LLVM 5de518080964bf3, Swift c6d1060778f3563)
2.      Compiling with effective version 5.10
3.      While evaluating request TypeCheckPrimaryFileRequest(source_file "/Users/hamish/src/swift-test-arena/main.swift")
4.      While evaluating request TypeCheckFunctionBodyRequest(main.(file).foo@/Users/hamish/src/swift-test-arena/main.swift:819:6)
5.      While type-checking statement at [/Users/hamish/src/swift-test-arena/main.swift:819:26 - line:821:1] RangeText="{
  _ = x.getKnownFolderLocations
"
6.      While type-checking expression at [/Users/hamish/src/swift-test-arena/main.swift:820:3 - line:820:9] RangeText="_ = x."
7.      While type-checking-target starting at /Users/hamish/src/swift-test-arena/main.swift:820:3
8.      While evaluating request AnyObjectLookupRequest(0x11e5e7508 AbstractFunctionDecl name=foo(_:) : (AnyObject) -> (), 'getKnownFolderLocations', { NL_ProtocolMembers, NL_IgnoreMissingImports })
9.      /Users/hamish/src/iPhoneOS.sdk/System/Library/Frameworks/FileProvider.framework/Headers/NSFileProviderKnownFolders.h:135:1: importing 'NSFileProviderKnownFolderSupporting::getKnownFolderLocations:completionHandler:'
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           0x0000000107f5aba4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x0000000107f58ec0 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x0000000107f5b220 SignalHandler(int, __siginfo*, void*) + 324
3  libsystem_platform.dylib 0x00000001810b4184 _sigtramp + 56
4  libsystem_pthread.dylib  0x000000018107ef70 pthread_kill + 288
5  libsystem_c.dylib        0x0000000180f8b908 abort + 128
6  libsystem_c.dylib        0x0000000180f8ac1c err + 0
7  swift-frontend           0x0000000107fcebfc swift::ClangImporter::Implementation::inferDefaultArgument(clang::QualType, swift::OptionalTypeKind, swift::DeclBaseName, llvm::StringRef, bool, bool, swift::importer::NameImporter&) (.cold.10) + 0
8  swift-frontend           0x00000001036f2d10 swift::ClangImporter::Implementation::importParameterType(clang::ParmVarDecl const*, swift::OptionalTypeKind, bool, bool, bool, bool, std::__1::optional<unsigned int>, llvm::ArrayRef<swift::GenericTypeParamDecl*>, llvm::function_ref<void (swift::Diagnostic&&)>) + 1792
9  swift-frontend           0x00000001036f4980 swift::ClangImporter::Implementation::importMethodParamsAndReturnType(swift::DeclContext const*, clang::ObjCMethodDecl const*, llvm::ArrayRef<clang::ParmVarDecl const*>, bool, bool, swift::ParameterList**, swift::importer::ImportedName, std::__1::optional<swift::ForeignAsyncConvention>&, std::__1::optional<swift::ForeignErrorConvention>&, swift::SpecialMethodKind) + 2716
10 swift-frontend           0x00000001036c577c (anonymous namespace)::SwiftDeclConverter::importObjCMethodDecl(clang::ObjCMethodDecl const*, swift::DeclContext*, bool, std::__1::optional<(anonymous namespace)::AccessorInfo>) + 2024
11 swift-frontend           0x00000001036c87f0 (anonymous namespace)::SwiftDeclConverter::VisitObjCMethodDecl(clang::ObjCMethodDecl const*) + 308
12 swift-frontend           0x00000001036bb238 swift::ClangImporter::Implementation::importDeclImpl(clang::NamedDecl const*, swift::importer::ImportNameVersion, bool&, bool&) + 816
13 swift-frontend           0x00000001036bc00c swift::ClangImporter::Implementation::importDeclAndCacheImpl(clang::NamedDecl const*, swift::importer::ImportNameVersion, bool, bool) + 484
14 swift-frontend           0x000000010369adac bool llvm::function_ref<bool (swift::importer::ImportedName, swift::importer::ImportNameVersion)>::callback_fn<swift::ClangImporter::Implementation::lookupObjCMembers(swift::SwiftLookupTable&, swift::DeclName, swift::VisibleDeclConsumer&)::$_0>(long, swift::importer::ImportedName, swift::importer::ImportNameVersion) + 60
15 swift-frontend           0x00000001036ee0ac swift::importer::NameImporter::forEachDistinctImportName(clang::NamedDecl const*, swift::importer::ImportNameVersion, llvm::function_ref<bool (swift::importer::ImportedName, swift::importer::ImportNameVersion)>) + 248
16 swift-frontend           0x000000010366bae8 swift::ClangImporter::Implementation::lookupObjCMembers(swift::SwiftLookupTable&, swift::DeclName, swift::VisibleDeclConsumer&) + 252
17 swift-frontend           0x000000010366b978 swift::ClangModuleUnit::lookupClassMember(swift::ImportPath::Access, swift::DeclName, llvm::SmallVectorImpl<swift::ValueDecl*>&) const + 132
18 swift-frontend           0x0000000103a37cf4 swift::ModuleDecl::lookupClassMember(swift::ImportPath::Access, swift::DeclName, llvm::SmallVectorImpl<swift::ValueDecl*>&) const + 228
19 swift-frontend           0x0000000103a74ca4 swift::AnyObjectLookupRequest::evaluate(swift::Evaluator&, swift::DeclContext const*, swift::DeclNameRef, swift::NLOptions) const + 140
20 swift-frontend           0x0000000103a81124 swift::AnyObjectLookupRequest::OutputType swift::Evaluator::getResultUncached<swift::AnyObjectLookupRequest, swift::AnyObjectLookupRequest::OutputType swift::evaluateOrDefault<swift::AnyObjectLookupRequest>(swift::Evaluator&, swift::AnyObjectLookupRequest, swift::AnyObjectLookupRequest::OutputType)::'lambda'()>(swift::AnyObjectLookupRequest const&, swift::AnyObjectLookupRequest::OutputType swift::evaluateOrDefault<swift::AnyObjectLookupRequest>(swift::Evaluator&, swift::AnyObjectLookupRequest, swift::AnyObjectLookupRequest::OutputType)::'lambda'()) + 248
21 swift-frontend           0x0000000103a73cbc swift::AnyObjectLookupRequest::OutputType swift::evaluateOrDefault<swift::AnyObjectLookupRequest>(swift::Evaluator&, swift::AnyObjectLookupRequest, swift::AnyObjectLookupRequest::OutputType) + 160
22 swift-frontend           0x0000000103a73aec swift::DeclContext::lookupQualified(swift::Type, swift::DeclNameRef, swift::SourceLoc, swift::NLOptions, llvm::SmallVectorImpl<swift::ValueDecl*>&) const + 140
23 swift-frontend           0x00000001035c26a4 swift::TypeChecker::lookupMember(swift::DeclContext*, swift::Type, swift::DeclNameRef, swift::SourceLoc, swift::optionset::OptionSet<swift::NameLookupFlags, unsigned int>) + 300
24 swift-frontend           0x0000000103437e48 swift::constraints::ConstraintSystem::lookupMember(swift::Type, swift::DeclNameRef, swift::SourceLoc) + 172
25 swift-frontend           0x000000010338cae0 swift::constraints::ConstraintSystem::performMemberLookup(swift::constraints::ConstraintKind, swift::DeclNameRef, swift::Type, swift::FunctionRefInfo, swift::constraints::ConstraintLocator*, bool) + 2716
26 swift-frontend           0x000000010338f634 swift::constraints::ConstraintSystem::simplifyMemberConstraint(swift::constraints::ConstraintKind, swift::Type, swift::DeclNameRef, swift::Type, swift::DeclContext*, swift::FunctionRefInfo, llvm::ArrayRef<swift::constraints::OverloadChoice>, swift::optionset::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 1424
27 swift-frontend           0x00000001033639d8 swift::constraints::ConstraintSystem::addValueMemberConstraint(swift::Type, swift::DeclNameRef, swift::Type, swift::DeclContext*, swift::FunctionRefInfo, llvm::ArrayRef<swift::constraints::OverloadChoice>, swift::constraints::ConstraintLocatorBuilder) + 212
28 swift-frontend           0x000000010336539c (anonymous namespace)::ConstraintGenerator::addMemberRefConstraints(swift::Expr*, swift::Expr*, swift::DeclNameRef, swift::FunctionRefInfo, llvm::ArrayRef<swift::ValueDecl*>) + 656
29 swift-frontend           0x000000010335ec08 (anonymous namespace)::ConstraintWalker::walkToExprPost(swift::Expr*) + 15232
30 swift-frontend           0x00000001038a7908 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 988
31 swift-frontend           0x00000001038a8adc (anonymous namespace)::Traversal::visitAssignExpr(swift::AssignExpr*) + 60
32 swift-frontend           0x00000001038a7788 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 604
33 swift-frontend           0x00000001038a7520 swift::Expr::walk(swift::ASTWalker&) + 32
34 swift-frontend           0x0000000103357bf8 swift::constraints::ConstraintSystem::generateConstraints(swift::Expr*, swift::DeclContext*) + 164
35 swift-frontend           0x00000001033564a8 swift::constraints::ConstraintSystem::generateConstraints(swift::constraints::SyntacticElementTarget&, swift::FreeTypeVariableBinding) + 508
36 swift-frontend           0x00000001033b2e24 swift::constraints::ConstraintSystem::solveImpl(swift::constraints::SyntacticElementTarget&, swift::FreeTypeVariableBinding) + 392
37 swift-frontend           0x00000001033b2740 swift::constraints::ConstraintSystem::solve(swift::constraints::SyntacticElementTarget&, swift::FreeTypeVariableBinding) + 144
38 swift-frontend           0x000000010353335c swift::TypeChecker::typeCheckTarget(swift::constraints::SyntacticElementTarget&, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::DiagnosticTransaction*) + 284
39 swift-frontend           0x00000001035331e4 swift::TypeChecker::typeCheckExpression(swift::constraints::SyntacticElementTarget&, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::DiagnosticTransaction*) + 196
40 swift-frontend           0x00000001035330ac swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::constraints::ContextualTypeInfo, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 96
41 swift-frontend           0x00000001035f87c0 (anonymous namespace)::StmtChecker::typeCheckASTNode(swift::ASTNode&) + 236
42 swift-frontend           0x00000001035fb9bc swift::ASTVisitor<(anonymous namespace)::StmtChecker, void, swift::Stmt*, void, void, void, void>::visit(swift::Stmt*) + 136
43 swift-frontend           0x00000001035fa1f4 bool (anonymous namespace)::StmtChecker::typeCheckStmt<swift::BraceStmt>(swift::BraceStmt*&) + 136
44 swift-frontend           0x00000001035f9b88 (anonymous namespace)::StmtChecker::typeCheckBody(swift::BraceStmt*&) + 32
45 swift-frontend           0x00000001035f98e0 swift::TypeCheckFunctionBodyRequest::evaluate(swift::Evaluator&, swift::AbstractFunctionDecl*) const + 1100
46 swift-frontend           0x00000001039a3520 swift::TypeCheckFunctionBodyRequest::OutputType swift::Evaluator::getResultUncached<swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckFunctionBodyRequest>(swift::Evaluator&, swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType)::'lambda'()>(swift::TypeCheckFunctionBodyRequest const&, swift::TypeCheckFunctionBodyRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckFunctionBodyRequest>(swift::Evaluator&, swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType)::'lambda'()) + 224
47 swift-frontend           0x00000001039230a4 swift::AbstractFunctionDecl::getTypecheckedBody() const + 112
48 swift-frontend           0x0000000103a43418 swift::SourceFile::typeCheckDelayedFunctions() + 96
49 swift-frontend           0x000000010363f8e4 swift::TypeCheckPrimaryFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 228
50 swift-frontend           0x00000001036410b4 swift::TypeCheckPrimaryFileRequest::OutputType swift::Evaluator::getResultUncached<swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckPrimaryFileRequest>(swift::Evaluator&, swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType)::'lambda'()>(swift::TypeCheckPrimaryFileRequest const&, swift::TypeCheckPrimaryFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckPrimaryFileRequest>(swift::Evaluator&, swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType)::'lambda'()) + 216
51 swift-frontend           0x000000010363f7d8 swift::performTypeChecking(swift::SourceFile&) + 84
52 swift-frontend           0x0000000102690d58 bool llvm::function_ref<bool (swift::SourceFile&)>::callback_fn<swift::CompilerInstance::performSema()::$_0>(long, swift::SourceFile&) + 16
53 swift-frontend           0x00000001026882d4 swift::CompilerInstance::forEachFileToTypeCheck(llvm::function_ref<bool (swift::SourceFile&)>) + 164
54 swift-frontend           0x0000000102688210 swift::CompilerInstance::performSema() + 76
55 swift-frontend           0x000000010244b6bc withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 60
56 swift-frontend           0x0000000102441188 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 700
57 swift-frontend           0x00000001024409e4 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2208
58 swift-frontend           0x0000000102232fa8 swift::mainEntry(int, char const**) + 3052
59 dyld                     0x0000000180cfc274 start + 2840
fish: Job 1, './swift -frontend -typecheck ~/…' terminated by signal SIGABRT (Abort)

This was originally found by the stress tester for the following test case:

import FileProvider
let _ = Array()
// RUN: %sourcekitd-test -req=typecontextinfo -pos=%(line-1):15 main.swift -- main.swift -sdk $(xcrun -sdk iphoneos --show-sdk-path) -target arm64-apple-ios16.0