Nullptr crash in `swift::SynthesizeAccessorRequest::evaluate`

[timsneath]

Swift version

Apple Swift version 6.2-dev (LLVM 84f765b899f6671, Swift 6713168)

Platform

macOS 26 25A5349a

Editor

Visual Studio Code Version: 1.103.2 (Universal) with Swift extension v2.11.20250806, LLDB DAP 0.2.16

Description

VSCode is in an endless SourceKit-LSP restart loop. Logs seem to show a segfault.

Steps to Reproduce

No response

Logging

sourcekit-lsp-diagnose-2025-08-29T11-52-25-07-00.zip

[ahoppen]

sourcekitd crashed and we have compiler crashes from around the same time, which is likely the same cause. Over to the compiler.

[ahoppen]

Stack trace

Thread 0 Crashed:
0   libsystem_kernel.dylib        	       0x19cfa45b0 __pthread_kill + 8
1   libsystem_pthread.dylib       	       0x19cfde848 pthread_kill + 296
2   libsystem_c.dylib             	       0x19ceacd30 raise + 32
3   swift-frontend                	       0x10a7d8c48 SignalHandler(int, __siginfo*, void*) + 348
4   libsystem_platform.dylib      	       0x19cfe8704 _sigtramp + 56
5   swift-frontend                	       0x1062e0f64 swift::SynthesizeAccessorRequest::evaluate(swift::Evaluator&, swift::AbstractStorageDecl*, swift::AccessorKind) const + 1412
6   swift-frontend                	       0x1062e0f64 swift::SynthesizeAccessorRequest::evaluate(swift::Evaluator&, swift::AbstractStorageDecl*, swift::AccessorKind) const + 1412
7   swift-frontend                	       0x106665f64 swift::SynthesizeAccessorRequest::OutputType swift::Evaluator::getResultUncached<swift::SynthesizeAccessorRequest, swift::SynthesizeAccessorRequest::OutputType swift::evaluateOrDefault<swift::SynthesizeAccessorRequest>(swift::Evaluator&, swift::SynthesizeAccessorRequest, swift::SynthesizeAccessorRequest::OutputType)::'lambda'()>(swift::SynthesizeAccessorRequest const&, swift::SynthesizeAccessorRequest::OutputType swift::evaluateOrDefault<swift::SynthesizeAccessorRequest>(swift::Evaluator&, swift::SynthesizeAccessorRequest, swift::SynthesizeAccessorRequest::OutputType)::'lambda'()) + 228
8   swift-frontend                	       0x106634e40 swift::AbstractStorageDecl::getSynthesizedAccessor(swift::AccessorKind) const + 124
9   swift-frontend                	       0x1061cfed0 (anonymous namespace)::ExprAvailabilityWalker::maybeDiagStorageAccess(swift::ValueDecl const*, swift::SourceRange, swift::DeclContext const*) const + 188
10  swift-frontend                	       0x1061ce4c4 (anonymous namespace)::ExprAvailabilityWalker::walkToExprPre(swift::Expr*) + 624
11  swift-frontend                	       0x1065becf0 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 44
12  swift-frontend                	       0x1065becb8 swift::Expr::walk(swift::ASTWalker&) + 32
13  swift-frontend                	       0x1061ceeb4 (anonymous namespace)::ExprAvailabilityWalker::walkToExprPre(swift::Expr*) + 3168
14  swift-frontend                	       0x1065becf0 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 44
15  swift-frontend                	       0x1065becb8 swift::Expr::walk(swift::ASTWalker&) + 32
16  swift-frontend                	       0x1061ce344 (anonymous namespace)::ExprAvailabilityWalker::walkToExprPre(swift::Expr*) + 240
17  swift-frontend                	       0x1065becf0 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 44
18  swift-frontend                	       0x1065bf9dc <deduplicated_symbol> + 32
19  swift-frontend                	       0x1065bee34 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 368
20  swift-frontend                	       0x1065becb8 swift::Expr::walk(swift::ASTWalker&) + 32
21  swift-frontend                	       0x1061c77c0 swift::diagnoseExprAvailability(swift::Expr const*, swift::DeclContext*) + 180
22  swift-frontend                	       0x10613c060 swift::performSyntacticExprDiagnostics(swift::Expr const*, swift::DeclContext const*, bool) + 1772
23  swift-frontend                	       0x106207750 (anonymous namespace)::SyntacticDiagnosticWalker::walkToExprPre(swift::Expr*) + 124
24  swift-frontend                	       0x1065becf0 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 44
25  swift-frontend                	       0x1065becb8 swift::Expr::walk(swift::ASTWalker&) + 32
26  swift-frontend                	       0x1061666e8 swift::constraints::SyntacticElementTarget::walk(swift::ASTWalker&) const + 592
27  swift-frontend                	       0x1062002b4 swift::TypeChecker::typeCheckTarget(swift::constraints::SyntacticElementTarget&, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::DiagnosticTransaction*) + 464
28  swift-frontend                	       0x106200088 swift::TypeChecker::typeCheckExpression(swift::constraints::SyntacticElementTarget&, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::DiagnosticTransaction*) + 196
29  swift-frontend                	       0x1062013c4 swift::TypeChecker::typeCheckBinding(swift::Pattern*&, swift::Expr*&, swift::DeclContext*, swift::Type, swift::PatternBindingDecl*, unsigned int, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 124
30  swift-frontend                	       0x10620160c swift::TypeChecker::typeCheckPatternBinding(swift::PatternBindingDecl*, unsigned int, swift::Type, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 264
31  swift-frontend                	       0x1062df69c swift::PatternBindingEntryRequest::evaluate(swift::Evaluator&, swift::PatternBindingDecl*, unsigned int) const + 1908
32  swift-frontend                	       0x106662990 swift::PatternBindingEntryRequest::OutputType swift::Evaluator::getResultUncached<swift::PatternBindingEntryRequest, swift::PatternBindingEntryRequest::OutputType swift::evaluateOrDefault<swift::PatternBindingEntryRequest>(swift::Evaluator&, swift::PatternBindingEntryRequest, swift::PatternBindingEntryRequest::OutputType)::'lambda'()>(swift::PatternBindingEntryRequest const&, swift::PatternBindingEntryRequest::OutputType swift::evaluateOrDefault<swift::PatternBindingEntryRequest>(swift::Evaluator&, swift::PatternBindingEntryRequest, swift::PatternBindingEntryRequest::OutputType)::'lambda'()) + 228
33  swift-frontend                	       0x106632e80 swift::PatternBindingDecl::getCheckedPatternBindingEntry(unsigned int) const + 124
34  swift-frontend                	       0x10624ad4c (anonymous namespace)::DeclChecker::visit(swift::Decl*) + 2336
35  swift-frontend                	       0x10624a414 swift::TypeChecker::typeCheckDecl(swift::Decl*) + 116
36  swift-frontend                	       0x1062d8120 swift::ASTVisitor<(anonymous namespace)::StmtChecker, void, swift::Stmt*, void, void, void, void>::visit(swift::Stmt*) + 152
37  swift-frontend                	       0x1062d6830 bool (anonymous namespace)::StmtChecker::typeCheckStmt<swift::BraceStmt>(swift::BraceStmt*&) + 136
38  swift-frontend                	       0x1062d617c (anonymous namespace)::StmtChecker::typeCheckBody(swift::BraceStmt*&) + 48
39  swift-frontend                	       0x1062d5e8c swift::TypeCheckFunctionBodyRequest::evaluate(swift::Evaluator&, swift::AbstractFunctionDecl*) const + 1092
40  swift-frontend                	       0x1066d20f0 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'()) + 240
41  swift-frontend                	       0x10664a2fc swift::AbstractFunctionDecl::getTypecheckedBody() const + 112
42  swift-frontend                	       0x10677c2e4 swift::SourceFile::typeCheckDelayedFunctions() + 96
43  swift-frontend                	       0x10631f6a8 swift::TypeCheckPrimaryFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 244
44  swift-frontend                	       0x106320f0c 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'()) + 232
45  swift-frontend                	       0x10631f58c swift::performTypeChecking(swift::SourceFile&) + 84
46  swift-frontend                	       0x1052d5cec bool llvm::function_ref<bool (swift::SourceFile&)>::callback_fn<swift::CompilerInstance::performSema()::$_0>(long, swift::SourceFile&) + 16
47  swift-frontend                	       0x1052ccce4 swift::CompilerInstance::forEachFileToTypeCheck(llvm::function_ref<bool (swift::SourceFile&)>) + 76
48  swift-frontend                	       0x1052ccc78 swift::CompilerInstance::performSema() + 76
49  swift-frontend                	       0x10509808c withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 60
50  swift-frontend                	       0x10508d728 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 716
51  swift-frontend                	       0x10508cee4 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2312
52  swift-frontend                	       0x104e30404 swift::mainEntry(int, char const**) + 3064
53  dyld                          	       0x19cc21924 start + 6400