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Meinersbur
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Nov 13, 2025
…am (llvm#167724) This got exposed by `09262656f32ab3f2e1d82e5342ba37eecac52522`. The underlying stream of `m_os` is referenced by the `TextDiagnostic` member of `TextDiagnosticPrinter`. It got turned into a `llvm::formatted_raw_ostream` in the commit above. When `~TextDiagnosticPrinter` (and thus `~TextDiagnostic`) is invoked, we now call `~formatted_raw_ostream`, which tries to access the underlying stream. But `m_os` was already deleted because it is earlier in the order of destruction in `TextDiagnosticPrinter`. Move the `m_os` member before the `TextDiagnosticPrinter` to avoid a use-after-free. Drive-by: * Also move the `m_output` member which the `m_os` holds a reference to. The fact it's a reference indicates the expectation is most likely that the string outlives the stream. The ASAN macOS bot is currently failing with this: ``` 08:15:39 ================================================================= 08:15:39 ==61103==ERROR: AddressSanitizer: heap-use-after-free on address 0x60600012cf40 at pc 0x00012140d304 bp 0x00016eecc850 sp 0x00016eecc848 08:15:39 READ of size 8 at 0x60600012cf40 thread T0 08:15:39 #0 0x00012140d300 in llvm::formatted_raw_ostream::releaseStream() FormattedStream.h:205 08:15:39 #1 0x00012140d3a4 in llvm::formatted_raw_ostream::~formatted_raw_ostream() FormattedStream.h:145 08:15:39 #2 0x00012604abf8 in clang::TextDiagnostic::~TextDiagnostic() TextDiagnostic.cpp:721 08:15:39 #3 0x00012605dc80 in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:30 08:15:39 #4 0x00012605dd5c in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:27 08:15:39 #5 0x0001231fb210 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47 08:15:39 llvm#6 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47 08:15:39 llvm#7 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91 08:15:39 llvm#8 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103 08:15:39 llvm#9 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93 08:15:39 llvm#10 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93 ... 08:15:39 08:15:39 0x60600012cf40 is located 32 bytes inside of 56-byte region [0x60600012cf20,0x60600012cf58) 08:15:39 freed by thread T0 here: 08:15:39 #0 0x0001018abb88 in _ZdlPv+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4bb88) 08:15:39 #1 0x0001231fb1c0 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47 08:15:39 #2 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47 08:15:39 #3 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91 08:15:39 #4 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103 08:15:39 #5 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93 08:15:39 llvm#6 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93 ... 08:15:39 08:15:39 previously allocated by thread T0 here: 08:15:39 #0 0x0001018ab760 in _Znwm+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4b760) 08:15:39 #1 0x0001231f8dec in lldb_private::ClangModulesDeclVendor::Create(lldb_private::Target&) ClangModulesDeclVendor.cpp:732 08:15:39 #2 0x00012320af58 in lldb_private::ClangPersistentVariables::GetClangModulesDeclVendor() ClangPersistentVariables.cpp:124 08:15:39 #3 0x0001232111f0 in lldb_private::ClangUserExpression::PrepareForParsing(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, bool) ClangUserExpression.cpp:536 08:15:39 #4 0x000123213790 in lldb_private::ClangUserExpression::Parse(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, lldb_private::ExecutionPolicy, bool, bool) ClangUserExpression.cpp:647 08:15:39 #5 0x00012032b258 in lldb_private::UserExpression::Evaluate(lldb_private::ExecutionContext&, lldb_private::EvaluateExpressionOptions const&, llvm::StringRef, llvm::StringRef, std::__1::shared_ptr<lldb_private::ValueObject>&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) UserExpression.cpp:280 08:15:39 llvm#6 0x000120724010 in lldb_private::Target::EvaluateExpression(llvm::StringRef, lldb_private::ExecutionContextScope*, std::__1::shared_ptr<lldb_private::ValueObject>&, lldb_private::EvaluateExpressionOptions const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) Target.cpp:2905 08:15:39 llvm#7 0x00011fc7bde0 in lldb::SBTarget::EvaluateExpression(char const*, lldb::SBExpressionOptions const&) SBTarget.cpp:2305 08:15:39 ==61103==ABORTING ... ```
Meinersbur
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Jan 5, 2026
…lvm#159480) When building rustc std for arm64e, core fails to compile successfully with the error: ``` Constant ValueID not recognized. UNREACHABLE executed at rust/src/llvm-project/llvm/lib/Transforms/Utils/FunctionComparator.cpp:523! ``` This is a result of function merging so I modified FunctionComparator.cpp as the ConstantPtrAuth value would go unchecked in the switch statement. The test case is a reduction from the failure in core and fails on main with: ``` ******************** FAIL: LLVM :: Transforms/MergeFunc/ptrauth-const-compare.ll (59809 of 59995) ******************** TEST 'LLVM :: Transforms/MergeFunc/ptrauth-const-compare.ll' FAILED ******************** Exit Code: 2 Command Output (stdout): -- # RUN: at line 3 /Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc < /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll | /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll # executed command: /Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc # .---command stderr------------ # | Constant ValueID not recognized. # | UNREACHABLE executed at /Users/oskarwirga/llvm-project/llvm/lib/Transforms/Utils/FunctionComparator.cpp:523! # | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug. # | Stack dump: # | 0. Program arguments: /Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc # | 1. Running pass "mergefunc" on module "<stdin>" # | #0 0x0000000103335770 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102651770) # | #1 0x00000001033336bc llvm::sys::RunSignalHandlers() (/Users/oskarwirga/llvm-project/build/bin/opt+0x10264f6bc) # | #2 0x0000000103336218 SignalHandler(int, __siginfo*, void*) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102652218) # | #3 0x000000018e6c16a4 (/usr/lib/system/libsystem_platform.dylib+0x1804ad6a4) # | #4 0x000000018e68788c (/usr/lib/system/libsystem_pthread.dylib+0x18047388c) # | #5 0x000000018e590a3c (/usr/lib/system/libsystem_c.dylib+0x18037ca3c) # | llvm#6 0x00000001032a84bc llvm::install_out_of_memory_new_handler() (/Users/oskarwirga/llvm-project/build/bin/opt+0x1025c44bc) # | llvm#7 0x00000001033b37c0 llvm::FunctionComparator::cmpMDNode(llvm::MDNode const*, llvm::MDNode const*) const (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026cf7c0) # | llvm#8 0x00000001033b4d90 llvm::FunctionComparator::cmpBasicBlocks(llvm::BasicBlock const*, llvm::BasicBlock const*) const (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026d0d90) # | llvm#9 0x00000001033b5234 llvm::FunctionComparator::compare() (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026d1234) # | llvm#10 0x0000000102d6d868 (anonymous namespace)::MergeFunctions::insert(llvm::Function*) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102089868) # | llvm#11 0x0000000102d6bc0c llvm::MergeFunctionsPass::runOnModule(llvm::Module&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102087c0c) # | llvm#12 0x0000000102d6b430 llvm::MergeFunctionsPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102087430) # | llvm#13 0x0000000102b90558 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x101eac558) # | llvm#14 0x0000000103734bc4 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::__1::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool, bool) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102a50bc4) # | llvm#15 0x000000010373cc28 optMain (/Users/oskarwirga/llvm-project/build/bin/opt+0x102a58c28) # | llvm#16 0x000000018e2e6b98 # `----------------------------- # error: command failed with exit status: -6 # executed command: /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll # .---command stderr------------ # | FileCheck error: '<stdin>' is empty. # | FileCheck command line: /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll # `----------------------------- # error: command failed with exit status: 2 ```
Meinersbur
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Jan 5, 2026
CHR builds the merged hot-path predicate with IRBuilder::CreateLogicalAnd. That helper is implemented as a select and can constant-fold to a non- Instruction (e.g. i1 true). The pass then attempted to mark the merged condition as having explicitly unknown branch weights when profile data is present, but it unconditionally did cast<Instruction>(MergedCondition), which can crash in release builds. Guard the metadata update with dyn_cast<Instruction> and pass the containing Function explicitly to avoid calling Instruction::getFunction when the value is not attached yet. Add a regression test that exercises the constant-folding case. Crashing stack: ``` 2. Running pass "chr" on function "repro_crash" #0 0x0000000003be00a4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (bin/opt+0x3be00a4) #1 0x0000000003bdd9e8 llvm::sys::RunSignalHandlers() (bin/opt+0x3bdd9e8) #2 0x0000000003be1300 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0 #3 0x0000ffffa8e1d840 (linux-vdso.so.1+0x840) #4 0x0000000003c815e0 llvm::Instruction::getFunction() const (bin/opt+0x3c815e0) #5 0x0000000003dcd35c llvm::setExplicitlyUnknownBranchWeightsIfProfiled(llvm::Instruction&, llvm::StringRef, llvm::Function const*) (bin/opt+0x3dcd35c) llvm#6 0x0000000004fb3670 (anonymous namespace)::CHR::addToMergedCondition(bool, llvm::Value*, llvm::Instruction*, (anonymous namespace)::CHRScope*, llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>&, llvm::Value*&) ControlHeightReduction.cpp:0:0 llvm#7 0x0000000004fa7d88 (anonymous namespace)::CHR::run() ControlHeightReduction.cpp:0:0 llvm#8 0x0000000004fa3618 llvm::ControlHeightReductionPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (bin/opt+0x4fa3618) ``` Tests: opt < llvm/test/Transforms/PGOProfile/chr-unknown-profdata-crash.ll -passes='require<profile-summary>,function(chr)' -force-chr -chr-merge-threshold=1 -disable-output
Meinersbur
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Jan 5, 2026
…ng destructor (llvm#174082)" This reverts commit 7976ac9. This is causing msan failures. msan-track-origins stack trace: ==9441==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x55c20df74ad3 in clang::interp::Pointer::operator=(clang::interp::Pointer&&) llvm-project/clang/lib/AST/ByteCode/Pointer.cpp:137:7 #1 0x55c20db81010 in bool clang::interp::InitGlobal<(clang::interp::PrimType)13, clang::interp::Pointer>(clang::interp::InterpState&, clang::interp::CodePtr, unsigned int) llvm-project/clang/lib/AST/ByteCode/Interp.h:1478:16 #2 0x55c20db7ec56 in emitInitGlobalPtr blaze-out/k8-fastbuild-msan/bin/llvm-project/clang/_virtual_includes/ast_bytecode_opcodes_gen/Opcodes.inc:26162:10 #3 0x55c20db7ec56 in clang::interp::EvalEmitter::emitInitGlobal(clang::interp::PrimType, unsigned int, clang::interp::SourceInfo) blaze-out/k8-fastbuild-msan/bin/llvm-project/clang/_virtual_includes/ast_bytecode_opcodes_gen/Opcodes.inc:26042:12 #4 0x55c20da58b87 in clang::interp::Compiler<clang::interp::EvalEmitter>::visitVarDecl(clang::VarDecl const*, clang::Expr const*, bool, bool) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4924:20 #5 0x55c20da64a61 in clang::interp::Compiler<clang::interp::EvalEmitter>::visitDeclAndReturn(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4831:14 llvm#6 0x55c20da7f290 in clang::interp::EvalEmitter::interpretDecl(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/EvalEmitter.cpp:66:14 llvm#7 0x55c20d970d23 in clang::interp::Context::evaluateAsInitializer(clang::interp::State&, clang::VarDecl const*, clang::Expr const*, clang::APValue&) llvm-project/clang/lib/AST/ByteCode/Context.cpp:141:16 llvm#8 0x55c20e25b8de in clang::Expr::EvaluateAsInitializer(clang::APValue&, clang::ASTContext const&, clang::VarDecl const*, llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&, bool) const llvm-project/clang/lib/AST/ExprConstant.cpp:20754:20 llvm#9 0x55c20da368d5 in clang::interp::Compiler<clang::interp::EvalEmitter>::visitDeclRef(clang::ValueDecl const*, clang::Expr const*) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:7162:19 llvm#10 0x55c20da34986 in clang::interp::Compiler<clang::interp::EvalEmitter>::VisitDeclRefExpr(clang::DeclRefExpr const*) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:7192:16 llvm#11 0x55c20da66666 in clang::StmtVisitorBase<llvm::make_const_ptr, clang::interp::Compiler<clang::interp::EvalEmitter>, bool>::Visit(clang::Stmt const*) blaze-out/k8-fastbuild-msan/bin/llvm-project/clang/include/clang/AST/StmtNodes.inc:474:1 llvm#12 0x55c20da65d3f in clang::interp::Compiler<clang::interp::EvalEmitter>::visit(clang::Expr const*) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4293:16 llvm#13 0x55c20da57348 in clang::interp::Compiler<clang::interp::EvalEmitter>::VisitCXXTypeidExpr(clang::CXXTypeidExpr const*) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:3893:14 llvm#14 0x55c20da66760 in clang::StmtVisitorBase<llvm::make_const_ptr, clang::interp::Compiler<clang::interp::EvalEmitter>, bool>::Visit(clang::Stmt const*) blaze-out/k8-fastbuild-msan/bin/llvm-project/clang/include/clang/AST/StmtNodes.inc:658:1 llvm#15 0x55c20da65d3f in clang::interp::Compiler<clang::interp::EvalEmitter>::visit(clang::Expr const*) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4293:16 llvm#16 0x55c20da58afc in clang::interp::Compiler<clang::interp::EvalEmitter>::visitVarDecl(clang::VarDecl const*, clang::Expr const*, bool, bool) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4921:18 llvm#17 0x55c20da64a61 in clang::interp::Compiler<clang::interp::EvalEmitter>::visitDeclAndReturn(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4831:14 llvm#18 0x55c20da7f290 in clang::interp::EvalEmitter::interpretDecl(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/EvalEmitter.cpp:66:14 llvm#19 0x55c20d970d23 in clang::interp::Context::evaluateAsInitializer(clang::interp::State&, clang::VarDecl const*, clang::Expr const*, clang::APValue&) llvm-project/clang/lib/AST/ByteCode/Context.cpp:141:16 llvm#20 0x55c20e25b8de in clang::Expr::EvaluateAsInitializer(clang::APValue&, clang::ASTContext const&, clang::VarDecl const*, llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&, bool) const llvm-project/clang/lib/AST/ExprConstant.cpp:20754:20 llvm#21 0x55c20dfdcc38 in clang::VarDecl::evaluateValueImpl(llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&, bool) const llvm-project/clang/lib/AST/Decl.cpp:2608:23 llvm#22 0x55c20dfdd1a2 in clang::VarDecl::checkForConstantInitialization(llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&) const llvm-project/clang/lib/AST/Decl.cpp:2687:7 llvm#23 0x55c20b9154da in clang::Sema::CheckCompleteVariableDeclaration(clang::VarDecl*) llvm-project/clang/lib/Sema/SemaDecl.cpp:14941:27 llvm#24 0x55c20b910f36 in clang::Sema::AddInitializerToDecl(clang::Decl*, clang::Expr*, bool) llvm-project/clang/lib/Sema/SemaDecl.cpp:14280:3 llvm#25 0x55c20ad044ee in clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::ForRangeInit*) llvm-project/clang/lib/Parse/ParseDecl.cpp:2639:17 llvm#26 0x55c20acfe9f8 in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) llvm-project/clang/lib/Parse/ParseDecl.cpp:2356:7 llvm#27 0x55c20abd8a43 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) llvm-project/clang/lib/Parse/Parser.cpp:1181:10 llvm#28 0x55c20abd7654 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) llvm-project/clang/lib/Parse/Parser.cpp:1203:12 llvm#29 0x55c20abd4d9c in clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) llvm-project/clang/lib/Parse/Parser.cpp:1031:14 llvm#30 0x55c20ac96f31 in clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&) llvm-project/clang/lib/Parse/ParseDeclCXX.cpp:240:7 llvm#31 0x55c20ac950c7 in clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) llvm-project/clang/lib/Parse/ParseDeclCXX.cpp:218:3 llvm#32 0x55c20acfb09b in clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) llvm-project/clang/lib/Parse/ParseDecl.cpp:1909:12 llvm#33 0x55c20abd3f88 in clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) llvm-project/clang/lib/Parse/Parser.cpp llvm#34 0x55c20abcfe33 in clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) llvm-project/clang/lib/Parse/Parser.cpp:744:12 llvm#35 0x55c20abb214e in clang::ParseAST(clang::Sema&, bool, bool) llvm-project/clang/lib/Parse/ParseAST.cpp:170:20 llvm#36 0x55c20a90adaa in clang::ASTFrontendAction::ExecuteAction() llvm-project/clang/lib/Frontend/FrontendAction.cpp:1432:3 llvm#37 0x55c20a9095bf in clang::FrontendAction::Execute() llvm-project/clang/lib/Frontend/FrontendAction.cpp:1312:3 llvm#38 0x55c20a76cdc7 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) llvm-project/clang/lib/Frontend/CompilerInstance.cpp:1004:33 llvm#39 0x55c20805aab0 in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) llvm-project/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:310:25 llvm#40 0x55c20802e823 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) llvm-project/clang/tools/driver/cc1_main.cpp:304:15 llvm#41 0x55c2080218ec in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) llvm-project/clang/tools/driver/driver.cpp:225:12 llvm#42 0x55c20801ea91 in clang_main(int, char**, llvm::ToolContext const&) llvm-project/clang/tools/driver/driver.cpp:268:12 llvm#43 0x55c20801a6af in main blaze-out/k8-fastbuild-msan/bin/llvm-project/clang/clang-driver.cpp:17:10 llvm#44 0x7f79c4214351 in __libc_start_main (/usr/libc/lib64/libc.so.6+0x61351) (BuildId: ca23ec6d935352118622ce674a8bb52d) llvm#45 0x55c207f8c2e9 in _start /usr/libc/debug-src/src/csu/../sysdeps/x86_64/start.S:120 Member fields were destroyed #0 0x55c207f9f5fd in __sanitizer_dtor_callback_fields llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1074:5 #1 0x55c20df74380 in ~Pointer llvm-project/clang/lib/AST/ByteCode/Pointer.h:826:12 #2 0x55c20df74380 in clang::interp::Pointer::~Pointer() llvm-project/clang/lib/AST/ByteCode/Pointer.cpp:93:1 #3 0x55c20da7c5ab in void dtorTy<clang::interp::Pointer>(clang::interp::Block*, std::byte*, clang::interp::Descriptor const*) llvm-project/clang/lib/AST/ByteCode/Descriptor.cpp:49:32 #4 0x55c20d976b91 in clang::interp::Block::invokeDtor() llvm-project/clang/lib/AST/ByteCode/InterpBlock.h:149:7 #5 0x55c20da651a1 in clang::interp::Compiler<clang::interp::EvalEmitter>::visitDeclAndReturn(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/Compiler.cpp:4869:22 llvm#6 0x55c20da7f290 in clang::interp::EvalEmitter::interpretDecl(clang::VarDecl const*, clang::Expr const*, bool) llvm-project/clang/lib/AST/ByteCode/EvalEmitter.cpp:66:14 llvm#7 0x55c20d970d23 in clang::interp::Context::evaluateAsInitializer(clang::interp::State&, clang::VarDecl const*, clang::Expr const*, clang::APValue&) llvm-project/clang/lib/AST/ByteCode/Context.cpp:141:16 llvm#8 0x55c20e25b8de in clang::Expr::EvaluateAsInitializer(clang::APValue&, clang::ASTContext const&, clang::VarDecl const*, llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&, bool) const llvm-project/clang/lib/AST/ExprConstant.cpp:20754:20 llvm#9 0x55c20dfdcc38 in clang::VarDecl::evaluateValueImpl(llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&, bool) const llvm-project/clang/lib/AST/Decl.cpp:2608:23 llvm#10 0x55c20dfdd1a2 in clang::VarDecl::checkForConstantInitialization(llvm::SmallVectorImpl<std::__msan::pair<clang::SourceLocation, clang::PartialDiagnostic>>&) const llvm-project/clang/lib/AST/Decl.cpp:2687:7 llvm#11 0x55c20b9154da in clang::Sema::CheckCompleteVariableDeclaration(clang::VarDecl*) llvm-project/clang/lib/Sema/SemaDecl.cpp:14941:27 llvm#12 0x55c20b910f36 in clang::Sema::AddInitializerToDecl(clang::Decl*, clang::Expr*, bool) llvm-project/clang/lib/Sema/SemaDecl.cpp:14280:3 llvm#13 0x55c20ad044ee in clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::ForRangeInit*) llvm-project/clang/lib/Parse/ParseDecl.cpp:2639:17 llvm#14 0x55c20acfe9f8 in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) llvm-project/clang/lib/Parse/ParseDecl.cpp:2356:7 llvm#15 0x55c20abd8a43 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) llvm-project/clang/lib/Parse/Parser.cpp:1181:10 llvm#16 0x55c20abd7654 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) llvm-project/clang/lib/Parse/Parser.cpp:1203:12 llvm#17 0x55c20abd4d9c in clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) llvm-project/clang/lib/Parse/Parser.cpp:1031:14 llvm#18 0x55c20ac96f31 in clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&) llvm-project/clang/lib/Parse/ParseDeclCXX.cpp:240:7 llvm#19 0x55c20ac950c7 in clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) llvm-project/clang/lib/Parse/ParseDeclCXX.cpp:218:3 llvm#20 0x55c20acfb09b in clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) llvm-project/clang/lib/Parse/ParseDecl.cpp:1909:12
Meinersbur
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Jan 19, 2026
… all redeclarations (llvm#176188) Fix handling of `lifetimebound` attributes on implicit `this` parameters across function redeclarations. Previously, the lifetime analysis would miss `lifetimebound` attributes on implicit `this` parameters if they were only present on certain redeclarations of a method. This could lead to false negatives in the lifetime safety analysis. This change ensures that if any redeclaration of a method has the attribute, it will be properly detected and used in the analysis. I can't seem to work around the crash in the earlier attempt llvm#172146. Reproducer of the original crash: ```cpp struct a { a &b() [[_Clang::__lifetimebound__]]; }; a &a::b() {} ``` This only crashes with `-target i686-w64-mingw32`. `bin/clang++ -c a.cpp` works fine. Problematic merging logic: ```cpp // If Old has lifetimebound but New doesn't, add it to New. if (OldLBAttr && !NewLBAttr) { QualType NewMethodType = New->getType(); QualType AttributedType = S.Context.getAttributedType(OldLBAttr, NewMethodType, NewMethodType); TypeLocBuilder TLB; TLB.pushFullCopy(NewTSI->getTypeLoc()); AttributedTypeLoc TyLoc = TLB.push<AttributedTypeLoc>(AttributedType); // Crashes. TyLoc.setAttr(OldLBAttr); New->setType(AttributedType); New->setTypeSourceInfo(TLB.getTypeSourceInfo(S.Context, AttributedType)); } ``` <details> <summary>Crash</summary> ``` clang++: /REDACTED//llvm-project/clang/lib/Sema/TypeLocBuilder.cpp:89: TypeLoc clang::TypeLocBuilder::pushImpl(QualType, size_t, unsigned int): Assertion `TLast == LastTy && "mismatch between last type and new type's inner type"' failed. PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: bin/clang++ -target i686-w64-mingw32 -c /REDACTED//a.cpp 1. /REDACTED//a.cpp:4:11: current parser token '{' #0 0x000055971cfcb838 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /REDACTED//llvm-project/llvm/lib/Support/Unix/Signals.inc:842:13 #1 0x000055971cfc9374 llvm::sys::RunSignalHandlers() /REDACTED//llvm-project/llvm/lib/Support/Signals.cpp:109:18 #2 0x000055971cfcaf0c llvm::sys::CleanupOnSignal(unsigned long) /REDACTED//llvm-project/llvm/lib/Support/Unix/Signals.inc:0:3 #3 0x000055971cf38116 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) /REDACTED//llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:73:5 #4 0x000055971cf38116 CrashRecoverySignalHandler(int) /REDACTED//llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:390:51 #5 0x00007fe9ebe49df0 (/lib/x86_64-linux-gnu/libc.so.6+0x3fdf0) llvm#6 0x00007fe9ebe9e95c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76 llvm#7 0x00007fe9ebe49cc2 raise ./signal/../sysdeps/posix/raise.c:27:6 llvm#8 0x00007fe9ebe324ac abort ./stdlib/abort.c:81:3 llvm#9 0x00007fe9ebe32420 __assert_perror_fail ./assert/assert-perr.c:31:1 llvm#10 0x000055971f969ade clang::TypeLocBuilder::pushImpl(clang::QualType, unsigned long, unsigned int) /REDACTED//llvm-project/clang/lib/Sema/TypeLocBuilder.cpp:93:3 llvm#11 0x000055971f237255 clang::QualType::hasLocalQualifiers() const /REDACTED//llvm-project/clang/include/clang/AST/TypeBase.h:1065:37 llvm#12 0x000055971f237255 clang::ConcreteTypeLoc<clang::UnqualTypeLoc, clang::AttributedTypeLoc, clang::AttributedType, clang::AttributedLocInfo>::isKind(clang::TypeLoc const&) /REDACTED//llvm-project/clang/include/clang/AST/TypeLoc.h:392:26 llvm#13 0x000055971f237255 clang::AttributedTypeLoc clang::TypeLoc::castAs<clang::AttributedTypeLoc>() const /REDACTED//llvm-project/clang/include/clang/AST/TypeLoc.h:79:5 llvm#14 0x000055971f237255 clang::AttributedTypeLoc clang::TypeLocBuilder::push<clang::AttributedTypeLoc>(clang::QualType) /REDACTED//llvm-project/clang/lib/Sema/TypeLocBuilder.h:106:47 llvm#15 0x000055971f280cc8 clang::AttributedTypeLoc::setAttr(clang::Attr const*) /REDACTED//llvm-project/clang/include/clang/AST/TypeLoc.h:1035:30 llvm#16 0x000055971f280cc8 mergeLifetimeBoundAttrOnMethod(clang::Sema&, clang::CXXMethodDecl*, clang::CXXMethodDecl const*) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:4497:11 llvm#17 0x000055971f280cc8 clang::Sema::MergeCompatibleFunctionDecls(clang::FunctionDecl*, clang::FunctionDecl*, clang::Scope*, bool) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:4528:5 llvm#18 0x000055971f27eb1f clang::Sema::MergeFunctionDecl(clang::FunctionDecl*, clang::NamedDecl*&, clang::Scope*, bool, bool) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:0:0 llvm#19 0x000055971f29c256 clang::Sema::CheckFunctionDeclaration(clang::Scope*, clang::FunctionDecl*, clang::LookupResult&, bool, bool) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:12371:9 llvm#20 0x000055971f28dab0 clang::Declarator::setRedeclaration(bool) /REDACTED//llvm-project/clang/include/clang/Sema/DeclSpec.h:2738:51 llvm#21 0x000055971f28dab0 clang::Sema::ActOnFunctionDeclarator(clang::Scope*, clang::Declarator&, clang::DeclContext*, clang::TypeSourceInfo*, clang::LookupResult&, llvm::MutableArrayRef<clang::TemplateParameterList*>, bool&) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:10877:9 llvm#22 0x000055971f2890fc clang::Sema::HandleDeclarator(clang::Scope*, clang::Declarator&, llvm::MutableArrayRef<clang::TemplateParameterList*>) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:0:11 llvm#23 0x000055971f2aab99 clang::Sema::ActOnStartOfFunctionDef(clang::Scope*, clang::Declarator&, llvm::MutableArrayRef<clang::TemplateParameterList*>, clang::SkipBodyInfo*, clang::Sema::FnBodyKind) /REDACTED//llvm-project/clang/lib/Sema/SemaDecl.cpp:15904:15 llvm#24 0x000055971efab286 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) /REDACTED//llvm-project/clang/lib/Parse/Parser.cpp:1364:23 llvm#25 0x000055971f013b40 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) /REDACTED//llvm-project/clang/lib/Parse/ParseDecl.cpp:2268:18 llvm#26 0x000055971efaa54f clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) /REDACTED//llvm-project/clang/lib/Parse/Parser.cpp:0:10 llvm#27 0x000055971efa9e36 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) /REDACTED//llvm-project/clang/lib/Parse/Parser.cpp:1202:12 llvm#28 0x000055971efa8df8 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) /REDACTED//llvm-project/clang/lib/Parse/Parser.cpp:0:14 llvm#29 0x000055971efa7574 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) /REDACTED//llvm-project/clang/lib/Parse/Parser.cpp:743:10 llvm#30 0x000055971ef9c0ee clang::ParseAST(clang::Sema&, bool, bool) /REDACTED//llvm-project/clang/lib/Parse/ParseAST.cpp:169:5 llvm#31 0x000055971dbcdad6 clang::FrontendAction::Execute() /REDACTED//llvm-project/clang/lib/Frontend/FrontendAction.cpp:1317:10 llvm#32 0x000055971db3c5fd llvm::Error::getPtr() const /REDACTED//llvm-project/llvm/include/llvm/Support/Error.h:278:42 llvm#33 0x000055971db3c5fd llvm::Error::operator bool() /REDACTED//llvm-project/llvm/include/llvm/Support/Error.h:241:16 llvm#34 0x000055971db3c5fd clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /REDACTED//llvm-project/clang/lib/Frontend/CompilerInstance.cpp:1006:23 llvm#35 0x000055971dcb4f9c clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /REDACTED//llvm-project/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:310:25 llvm#36 0x000055971a5e655e cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /REDACTED//llvm-project/clang/tools/driver/cc1_main.cpp:304:15 llvm#37 0x000055971a5e29cb ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) /REDACTED//llvm-project/clang/tools/driver/driver.cpp:226:12 llvm#38 0x000055971a5e4c1d clang_main(int, char**, llvm::ToolContext const&)::$_0::operator()(llvm::SmallVectorImpl<char const*>&) const /REDACTED//llvm-project/clang/tools/driver/driver.cpp:0:12 llvm#39 0x000055971a5e4c1d int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::$_0>(long, llvm::SmallVectorImpl<char const*>&) /REDACTED//llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:46:12 llvm#40 0x000055971d9bfe79 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::$_0::operator()() const /REDACTED//llvm-project/clang/lib/Driver/Job.cpp:442:30 llvm#41 0x000055971d9bfe79 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::$_0>(long) /REDACTED//llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:46:12 llvm#42 0x000055971cf37dbe llvm::function_ref<void ()>::operator()() const /REDACTED//llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:0:12 llvm#43 0x000055971cf37dbe llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) /REDACTED//llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:426:3 llvm#44 0x000055971d9bf5ac clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const /REDACTED//llvm-project/clang/lib/Driver/Job.cpp:442:7 llvm#45 0x000055971d98422c clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const /REDACTED//llvm-project/clang/lib/Driver/Compilation.cpp:196:15 llvm#46 0x000055971d984447 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const /REDACTED//llvm-project/clang/lib/Driver/Compilation.cpp:246:13 llvm#47 0x000055971d99ee08 llvm::SmallVectorBase<unsigned int>::empty() const /REDACTED//llvm-project/llvm/include/llvm/ADT/SmallVector.h:83:46 llvm#48 0x000055971d99ee08 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) /REDACTED//llvm-project/clang/lib/Driver/Driver.cpp:2265:23 llvm#49 0x000055971a5e2303 clang_main(int, char**, llvm::ToolContext const&) /REDACTED//llvm-project/clang/tools/driver/driver.cpp:414:21 llvm#50 0x000055971a5f2527 main /usr/local/google/home/usx/build/tools/clang/tools/driver/clang-driver.cpp:17:10 llvm#51 0x00007fe9ebe33ca8 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3 llvm#52 0x00007fe9ebe33d65 call_init ./csu/../csu/libc-start.c:128:20 llvm#53 0x00007fe9ebe33d65 __libc_start_main ./csu/../csu/libc-start.c:347:5 llvm#54 0x000055971a5e0361 _start (bin/clang+++0x6636361) clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation) clang version 23.0.0git (https://github.com/llvm/llvm-project.git 282a065) Target: i686-w64-windows-gnu Thread model: posix InstalledDir: /usr/local/google/home/usx/build/bin Build config: +assertions clang++: note: diagnostic msg: ******************** ``` </details>
Meinersbur
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Jan 27, 2026
This reverts commit 99fab01. llc was crashing in kernel-args.ll after this patch: ``` .---command stderr------------ | LLVM ERROR: Cannot select: t3: f32,ch = load<(non-temporal dereferenceable invariant load (s16), align 4, addrspace 7), sext from f16> t0, Constant:i32<36>, undef:i32 | In function: f16_arg | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug. | Stack dump: | 0. Program arguments: /b/ml-opt-devrel-x86-64-b1/build/bin/llc -mtriple=r600 -mcpu=redwood | 1. Running pass 'Function Pass Manager' on module '<stdin>'. | 2. Running pass 'Unnamed pass: implement Pass::getPassName()' on function '@f16_arg' | #0 0x0000561402607438 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x81a7438) | #1 0x0000561402604b75 llvm::sys::RunSignalHandlers() (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x81a4b75) | #2 0x00005614026081b1 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0 | #3 0x00007f55eb45a050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050) | #4 0x00007f55eb4a8eec (/lib/x86_64-linux-gnu/libc.so.6+0x8aeec) | #5 0x00007f55eb459fb2 raise (/lib/x86_64-linux-gnu/libc.so.6+0x3bfb2) | llvm#6 0x00007f55eb444472 abort (/lib/x86_64-linux-gnu/libc.so.6+0x26472) | llvm#7 0x0000561402567005 llvm::report_fatal_error(llvm::Twine const&, bool) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x8107005) | llvm#8 0x00005614023e7ba7 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f87ba7) | llvm#9 0x00005614023e6a7d llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f86a7d) | llvm#10 0x00005614023dae94 llvm::SelectionDAGISel::DoInstructionSelection() (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f7ae94) | llvm#11 0x00005614023d9e6a llvm::SelectionDAGISel::CodeGenAndEmitDAG() (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f79e6a) | llvm#12 0x00005614023d7b5e llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f77b5e) | llvm#13 0x00005614023d4c30 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f74c30) | llvm#14 0x00005614023d22e0 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7f722e0) | llvm#15 0x0000561401611793 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x71b1793) | llvm#16 0x0000561401b790e5 llvm::FPPassManager::runOnFunction(llvm::Function&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x77190e5) | llvm#17 0x0000561401b80f72 llvm::FPPassManager::runOnModule(llvm::Module&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7720f72) | llvm#18 0x0000561401b79b56 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x7719b56) | llvm#19 0x00005613ff4858f4 compileModule(char**, llvm::SmallVectorImpl<llvm::PassPlugin>&, llvm::LLVMContext&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&) llc.cpp:0:0 | llvm#20 0x00005613ff482ed3 main (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x5022ed3) | llvm#21 0x00007f55eb44524a (/lib/x86_64-linux-gnu/libc.so.6+0x2724a) | llvm#22 0x00007f55eb445305 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x27305) | llvm#23 0x00005613ff47ea21 _start (/b/ml-opt-devrel-x86-64-b1/build/bin/llc+0x501ea21) `----------------------------- ```
Meinersbur
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Feb 2, 2026
…lvm#178069) Kernel panic is a special case, and there is no signal or exception for that so we need to rely on special workaround called `dumptid`. FreeBSDKernel plugin is supposed to find this thread and set it manually through `SetStopInfo()` in `CalculateStopInfo()` like Mach core plugin does. Before (We had to find and select crashed thread list otherwise thread 1 was selected by default): ``` ➜ sudo lldb /boot/panic/kernel -c /var/crash/vmcore.last (lldb) target create "/boot/panic/kernel" --core "/var/crash/vmcore.last" Core file '/var/crash/vmcore.last' (x86_64) was loaded. (lldb) bt * thread #1, name = '(pid 12991) dtrace' * frame #0: 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015882f780, flags=259) at sched_ule.c:2448:26 frame #1: 0xffffffff80bd38d2 kernel`mi_switch(flags=259) at kern_synch.c:530:2 frame #2: 0xffffffff80c29799 kernel`sleepq_switch(wchan=0xfffff8014edff300, pri=0) at subr_sleepqueue.c:608:2 frame #3: 0xffffffff80c29b76 kernel`sleepq_catch_signals(wchan=0xfffff8014edff300, pri=0) at subr_sleepqueue.c:523:3 frame #4: 0xffffffff80c29d32 kernel`sleepq_timedwait_sig(wchan=<unavailable>, pri=<unavailable>) at subr_sleepqueue.c:704:11 frame #5: 0xffffffff80bd2e2d kernel`_sleep(ident=0xfffff8014edff300, lock=0xffffffff81df2880, priority=768, wmesg="uwait", sbt=2573804118162, pr=0, flags=512) at kern_synch.c:215:10 frame llvm#6: 0xffffffff80be8622 kernel`umtxq_sleep(uq=0xfffff8014edff300, wmesg="uwait", timo=0xfffffe0279cb3d20) at kern_umtx.c:843:11 frame llvm#7: 0xffffffff80bef87a kernel`do_wait(td=0xfffff8015882f780, addr=<unavailable>, id=0, timeout=0xfffffe0279cb3d90, compat32=1, is_private=1) at kern_umtx.c:1316:12 frame llvm#8: 0xffffffff80bed264 kernel`__umtx_op_wait_uint_private(td=0xfffff8015882f780, uap=0xfffffe0279cb3dd8, ops=<unavailable>) at kern_umtx.c:3990:10 frame llvm#9: 0xffffffff80beaabe kernel`sys__umtx_op [inlined] kern__umtx_op(td=<unavailable>, obj=<unavailable>, op=<unavailable>, val=<unavailable>, uaddr1=<unavailable>, uaddr2=<unavailable>, ops=<unavailable>) at kern_umtx.c:4999:10 frame llvm#10: 0xffffffff80beaa89 kernel`sys__umtx_op(td=<unavailable>, uap=<unavailable>) at kern_umtx.c:5024:10 frame llvm#11: 0xffffffff81122cd1 kernel`amd64_syscall [inlined] syscallenter(td=0xfffff8015882f780) at subr_syscall.c:165:11 frame llvm#12: 0xffffffff81122c19 kernel`amd64_syscall(td=0xfffff8015882f780, traced=0) at trap.c:1208:2 frame llvm#13: 0xffffffff810f1dbb kernel`fast_syscall_common at exception.S:570 ``` After: ``` ➜ sudo ./build/bin/lldb /boot/panic/kernel -c /var/crash/vmcore.last (lldb) target create "/boot/panic/kernel" --core "/var/crash/vmcore.last" Core file '/var/crash/vmcore.last' (x86_64) was loaded. (lldb) bt * thread llvm#18, name = '(pid 5409) powerd (crashed)', stop reason = kernel panic * frame #0: 0xffffffff80bc6c91 kernel`__curthread at pcpu_aux.h:57:2 [inlined] frame #1: 0xffffffff80bc6c91 kernel`doadump(textdump=0) at kern_shutdown.c:399:2 frame #2: 0xffffffff804b3b7a kernel`db_dump(dummy=<unavailable>, dummy2=<unavailable>, dummy3=<unavailable>, dummy4=<unavailable>) at db_command.c:596:10 frame #3: 0xffffffff804b396d kernel`db_command(last_cmdp=<unavailable>, cmd_table=<unavailable>, dopager=true) at db_command.c:508:3 frame #4: 0xffffffff804b362d kernel`db_command_loop at db_command.c:555:3 frame #5: 0xffffffff804b7026 kernel`db_trap(type=<unavailable>, code=<unavailable>) at db_main.c:267:3 frame llvm#6: 0xffffffff80c16aaf kernel`kdb_trap(type=3, code=0, tf=0xfffffe01b605b930) at subr_kdb.c:790:13 frame llvm#7: 0xffffffff8112154e kernel`trap(frame=<unavailable>) at trap.c:614:8 frame llvm#8: 0xffffffff810f14c8 kernel`calltrap at exception.S:285 frame llvm#9: 0xffffffff81da2290 kernel`cn_devtab + 64 frame llvm#10: 0xfffffe01b605b8b0 frame llvm#11: 0xffffffff84001c43 dtrace.ko`dtrace_panic(format=<unavailable>) at dtrace.c:652:2 frame llvm#12: 0xffffffff84005524 dtrace.ko`dtrace_action_panic(ecb=0xfffff80539cad580) at dtrace.c:7022:2 [inlined] frame llvm#13: 0xffffffff840054de dtrace.ko`dtrace_probe(id=88998, arg0=14343377283488, arg1=<unavailable>, arg2=<unavailable>, arg3=<unavailable>, arg4=<unavailable>) at dtrace.c:7665:6 frame llvm#14: 0xffffffff83e5213d systrace.ko`systrace_probe(sa=<unavailable>, type=<unavailable>, retval=<unavailable>) at systrace.c:226:2 frame llvm#15: 0xffffffff8112318d kernel`syscallenter(td=0xfffff801318d5780) at subr_syscall.c:160:4 [inlined] frame llvm#16: 0xffffffff81123112 kernel`amd64_syscall(td=0xfffff801318d5780, traced=0) at trap.c:1208:2 frame llvm#17: 0xffffffff810f1dbb kernel`fast_syscall_common at exception.S:570 ```
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Feb 7, 2026
…8306) In FreeBSD, allproc is a prepend list and new processes are appended at head. This results in reverse pid order, so we first need to order pid incrementally then print threads according to the correct order. Before: ``` Process 0 stopped * thread #1: tid = 101866, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015882f780, flags=259) at sched_ule.c:2448:26, name = '(pid 12991) dtrace' thread #2: tid = 101915, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80158825780, flags=259) at sched_ule.c:2448:26, name = '(pid 11509) zsh' thread #3: tid = 101942, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80142599000, flags=259) at sched_ule.c:2448:26, name = '(pid 11504) ftcleanup' thread #4: tid = 101545, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80131898000, flags=259) at sched_ule.c:2448:26, name = '(pid 5599) zsh' thread #5: tid = 100905, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80131899000, flags=259) at sched_ule.c:2448:26, name = '(pid 5598) sshd-session' thread llvm#6: tid = 101693, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015886e780, flags=259) at sched_ule.c:2448:26, name = '(pid 5595) sshd-session' thread llvm#7: tid = 101626, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801588be000, flags=259) at sched_ule.c:2448:26, name = '(pid 5592) sh' ... ``` After: ``` (lldb) thread list Process 0 stopped * thread #1: tid = 100000, 0xffffffff80bf9322 kernel`sched_switch(td=0xffffffff81abe840, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel' thread #2: tid = 100035, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d9780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_0' thread #3: tid = 100036, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d9000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_1' thread #4: tid = 100037, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d8780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_2' thread #5: tid = 100038, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d8000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_3' thread llvm#6: tid = 100039, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d7780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_4' thread llvm#7: tid = 100040, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d7000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_5' ... ``` Signed-off-by: Minsoo Choo <minsoochoo0122@proton.me>
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Feb 19, 2026
…er. (llvm#181941) The progress event reporter has a thread that reports events every 250 millisecond. and is destroyed in its destructor. When in event reporter desctructor, the event reporter may have pending event but the call mutex is destroyed leading to the crash. Relevant stack trace from CI. ``` [2026-02-13T17:46:13.577Z] libc++abi: terminating due to uncaught exception of type std::__1::system_error: mutex lock failed: Invalid argument [2026-02-13T17:46:13.577Z] PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash report from ~/Library/Logs/DiagnosticReports/. [2026-02-13T17:46:13.577Z] #0 0x0000000102b6943c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x10008943c) [2026-02-13T17:46:13.577Z] #1 0x0000000102b67368 llvm::sys::RunSignalHandlers() (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x100087368) [2026-02-13T17:46:13.577Z] #2 0x0000000102b69f20 SignalHandler(int, __siginfo*, void*) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x100089f20) [2026-02-13T17:46:13.577Z] #3 0x000000018bbdb744 (/usr/lib/system/libsystem_platform.dylib+0x1804e3744) [2026-02-13T17:46:13.577Z] #4 0x000000018bbd1888 (/usr/lib/system/libsystem_pthread.dylib+0x1804d9888) [2026-02-13T17:46:13.577Z] #5 0x000000018bad6850 (/usr/lib/system/libsystem_c.dylib+0x1803de850) [2026-02-13T17:46:13.577Z] llvm#6 0x000000018bb85858 (/usr/lib/libc++abi.dylib+0x18048d858) [2026-02-13T17:46:13.577Z] llvm#7 0x000000018bb744bc (/usr/lib/libc++abi.dylib+0x18047c4bc) [2026-02-13T17:46:13.577Z] llvm#8 0x000000018b7a0424 (/usr/lib/libobjc.A.dylib+0x1800a8424) [2026-02-13T17:46:13.577Z] llvm#9 0x000000018bb84c2c (/usr/lib/libc++abi.dylib+0x18048cc2c) [2026-02-13T17:46:13.577Z] llvm#10 0x000000018bb88394 (/usr/lib/libc++abi.dylib+0x180490394) [2026-02-13T17:46:13.577Z] llvm#11 0x000000018bb8833c (/usr/lib/libc++abi.dylib+0x18049033c) [2026-02-13T17:46:13.577Z] llvm#12 0x000000018bb01b90 (/usr/lib/libc++.1.dylib+0x180409b90) [2026-02-13T17:46:13.577Z] llvm#13 0x000000018bb01b34 (/usr/lib/libc++.1.dylib+0x180409b34) [2026-02-13T17:46:13.577Z] llvm#14 0x000000018bb038a0 (/usr/lib/libc++.1.dylib+0x18040b8a0) [2026-02-13T17:46:13.577Z] llvm#15 0x0000000102b6fbac lldb_dap::DAP::Send(std::__1::variant<lldb_dap::protocol::Request, lldb_dap::protocol::Response, lldb_dap::protocol::Event> const&) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x10008fbac) [2026-02-13T17:46:13.577Z] llvm#16 0x0000000102b6f890 lldb_dap::DAP::SendJSON(llvm::json::Value const&) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x10008f890) [2026-02-13T17:46:13.577Z] llvm#17 0x0000000102b78788 std::__1::__function::__func<lldb_dap::DAP::DAP(lldb_dap::Log&, lldb_dap::ReplMode, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, bool, llvm::StringRef, lldb_private::transport::JSONTransport<lldb_dap::ProtocolDescriptor>&, lldb_private::MainLoopPosix&)::$_0, std::__1::allocator<lldb_dap::DAP::DAP(lldb_dap::Log&, lldb_dap::ReplMode, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, bool, llvm::StringRef, lldb_private::transport::JSONTransport<lldb_dap::ProtocolDescriptor>&, lldb_private::MainLoopPosix&)::$_0>, void (lldb_dap::ProgressEvent&)>::operator()(lldb_dap::ProgressEvent&) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x100098788) [2026-02-13T17:46:13.577Z] llvm#18 0x0000000102b8939c lldb_dap::ProgressEventManager::ReportIfNeeded() (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x1000a939c) [2026-02-13T17:46:13.577Z] llvm#19 0x0000000102b8982c lldb_dap::ProgressEventReporter::ReportStartEvents() (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x1000a982c) [2026-02-13T17:46:13.577Z] llvm#20 0x0000000102b8a038 void* std::__1::__thread_proxy[abi:nn200100]<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct>>, lldb_dap::ProgressEventReporter::ProgressEventReporter(std::__1::function<void (lldb_dap::ProgressEvent&)>)::$_0>>(void*) (/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake-os-verficiation/lldb-build/bin/lldb-dap+0x1000aa038) [2026-02-13T17:46:13.577Z] llvm#21 0x000000018bbd1c08 (/usr/lib/system/libsystem_pthread.dylib+0x1804d9c08) [2026-02-13T17:46:13.577Z] llvm#22 0x000000018bbccba8 (/usr/lib/system/libsystem_pthread.dylib+0x1804d4ba8) ``` rdar://170331108
Meinersbur
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Feb 19, 2026
I created an issue about this in llvm#179976. Clang's Address Sanitizer installs its own SEH filter which handles some types of uncaught exceptions. Along with register values and some other information, it also generates a stack trace. However, current logic is incomplete. It relies on DbgHelp's SymFunctionTableAccess64 and SymGetModuleBase64 which won't work with machine code that has its RUNTIME_FUNCTION entry registered with Rtl* (e.g. RtlAddFunctionTable) system calls. Most likely, this is because DbgHelp either relies on information in PDB files or considers PDATA and XDATA only from loaded EXE and DLL modules. Either way, consider the following example: ``` #include <windows.h> #include <iostream> #include <vector> typedef union _UNWIND_CODE { struct { BYTE CodeOffset; BYTE UnwindOp : 4; BYTE OpInfo : 4; }; USHORT FrameOffset; } UNWIND_CODE, * PUNWIND_CODE; typedef struct _UNWIND_INFO { BYTE Version : 3; BYTE Flags : 5; BYTE SizeOfProlog; BYTE CountOfCodes; BYTE FrameRegister : 4; BYTE FrameOffset : 4; UNWIND_CODE UnwindCode[1]; // Variable size } UNWIND_INFO, * PUNWIND_INFO; #define UWOP_PUSH_NONVOL 0 #define UWOP_ALLOC_LARGE 1 #define UWOP_ALLOC_SMALL 2 #define UWOP_SET_FPREG 3 #define UWOP_SAVE_NONVOL 4 #define UWOP_SAVE_NONVOL_FAR 5 #define UWOP_SAVE_XMM128 8 #define UWOP_SAVE_XMM128_FAR 9 #define UWOP_PUSH_MACHFRAME 10 int main() { // PUSH RBX (0x53) - Save non-volatile register // SUB RSP, 0x20 (0x48 0x83 0xEC 0x20) - Allocate 32 bytes (shadow space) // XOR RAX, RAX (0x48 0x31 0xC0) - Zero out RAX // MOV RAX, [RAX] (0x48 0x8B 0x00) - Dereference NULL std::vector<unsigned char> code = { 0x53, 0x48, 0x83, 0xEC, 0x20, 0x48, 0x31, 0xC0, 0x48, 0x8B, 0x00 }; size_t codeSize = code.size(); size_t totalSize = 100; LPVOID pMemory = VirtualAlloc(NULL, totalSize, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); BYTE* pCodeBase = (BYTE*)pMemory; PUNWIND_INFO pUnwindInfo = (PUNWIND_INFO)(pCodeBase + codeSize); size_t alignmentPadding = 0; if ((size_t)pUnwindInfo % 4 != 0) { alignmentPadding = 4 - ((size_t)pUnwindInfo % 4); pUnwindInfo = (PUNWIND_INFO)((BYTE*)pUnwindInfo + alignmentPadding); } memcpy(pCodeBase, code.data(), codeSize); pUnwindInfo->Version = 1; pUnwindInfo->Flags = UNW_FLAG_NHANDLER; pUnwindInfo->Flags = 0; pUnwindInfo->SizeOfProlog = 5; pUnwindInfo->CountOfCodes = 2; pUnwindInfo->FrameRegister = 0; pUnwindInfo->FrameOffset = 0; pUnwindInfo->UnwindCode[0].CodeOffset = 5; pUnwindInfo->UnwindCode[0].UnwindOp = UWOP_ALLOC_SMALL; pUnwindInfo->UnwindCode[0].OpInfo = 3; pUnwindInfo->UnwindCode[1].CodeOffset = 1; pUnwindInfo->UnwindCode[1].UnwindOp = UWOP_PUSH_NONVOL; pUnwindInfo->UnwindCode[1].OpInfo = 3; // RBX RUNTIME_FUNCTION tableEntry = {}; tableEntry.BeginAddress = 0; tableEntry.EndAddress = (DWORD)codeSize; tableEntry.UnwindData = (DWORD)((BYTE*)pUnwindInfo - (BYTE*)pMemory); DWORD64 baseAddress = (DWORD64)pMemory; RtlAddFunctionTable(&tableEntry, 1, baseAddress); typedef void(*FuncType)(); FuncType myFunc = (FuncType)pMemory; myFunc(); return 0; } ``` Windows' kernel can propagate hardware exception through that function, so clearly these entries are at least partially correct. Right now, ASan's stack walking produces this (compiled with latest release, clang++): ``` PS D:\Local Projects\cpp-playground> ./a.exe ================================================================= ==14216==ERROR: AddressSanitizer: access-violation on unknown address 0x000000000000 (pc 0x0199561c0008 bp 0x004cf0cffb30 sp 0x004cf0cff970 T0) ==14216==The signal is caused by a READ memory access. ==14216==Hint: address points to the zero page. #0 0x0199561c0007 (<unknown module>) #1 0x000000000000 (<unknown module>) #2 0x000000000000 (<unknown module>) ==14216==Register values: rax = 0 rbx = 4cf0cffaa0 rcx = 7ffcb97b4e28 rdx = 19955dc0000 rdi = 11bf564a0040 rsi = 0 rbp = 4cf0cffb30 rsp = 4cf0cff970 r8 = 7ffffffffffffffc r9 = 1 r10 = 0 r11 = 246 r12 = 0 r13 = 0 r14 = 0 r15 = 0 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: access-violation (<unknown module>) ==14216==ABORTING ``` Frames one and two is just some stack space allocated by that dynamic function. While patched version produces this: ``` PS D:\Local Projects\cpp-playground> ./a.exe ================================================================= ==13660==ERROR: AddressSanitizer: access-violation on unknown address 0x000000000000 (pc 0x01ed5ad70008 bp 0x00d76492f650 sp 0x00d76492f490 T0) ==13660==The signal is caused by a READ memory access. ==13660==Hint: address points to the zero page. #0 0x01ed5ad70007 (<unknown module>) #1 0x7ff732e518a1 in main (D:\Local Projects\cpp-playground\a.exe+0x1400018a1) #2 0x7ff732e56a9b in invoke_main D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78 #3 0x7ff732e56a9b in __scrt_common_main_seh D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288 #4 0x7ffcb878e8d6 (C:\WINDOWS\System32\KERNEL32.DLL+0x18002e8d6) #5 0x7ffcb966c53b (C:\WINDOWS\SYSTEM32\ntdll.dll+0x18008c53b) ==13660==Register values: rax = 0 rbx = d76492f5c0 rcx = 7ffcb97b4e28 rdx = 1ed5a870000 rdi = 12135afa0040 rsi = 0 rbp = d76492f650 rsp = d76492f490 r8 = 7ffffffffffffffc r9 = 1 r10 = 0 r11 = 246 r12 = 0 r13 = 0 r14 = 0 r15 = 0 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: access-violation (<unknown module>) ==13660==ABORTING ``` Now we see that stack walking handled our dynamic function properly. Interestingly enough, it appears that other overloaded version of UnwindSlow procedure that works without CONTEXT structure already has some logic to handle this. Theoretically, symbolizer should also be able to provide some information about these functions, but I don't think that this is necessary. I added SANITIZER_WINDOWS64 check because I am pretty sure Microsoft only mentions these functions for 64 bit version of their OS. I also can't check how this works on ARM.
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Mar 12, 2026
Using code/ideas from the x86 backend to optimize a select on a bitcast integer. The previous aarch64 approach was to individually extract the bits from the mask, which is kind of terrible. https://rust.godbolt.org/z/576sndT66 ```llvm define void @if_then_else8(ptr %out, i8 %mask, ptr %if_true, ptr %if_false) { start: %t = load <8 x i32>, ptr %if_true, align 4 %f = load <8 x i32>, ptr %if_false, align 4 %m = bitcast i8 %mask to <8 x i1> %s = select <8 x i1> %m, <8 x i32> %t, <8 x i32> %f store <8 x i32> %s, ptr %out, align 4 ret void } ``` turned into ```asm if_then_else8: // @if_then_else8 sub sp, sp, llvm#16 ubfx w8, w1, #4, #1 and w11, w1, #0x1 ubfx w9, w1, #5, #1 fmov s1, w11 ubfx w10, w1, #1, #1 fmov s0, w8 ubfx w8, w1, llvm#6, #1 ldp q5, q2, [x3] mov v1.h[1], w10 ldp q4, q3, [x2] mov v0.h[1], w9 ubfx w9, w1, #2, #1 mov v1.h[2], w9 ubfx w9, w1, #3, #1 mov v0.h[2], w8 ubfx w8, w1, llvm#7, #1 mov v1.h[3], w9 mov v0.h[3], w8 ushll v1.4s, v1.4h, #0 ushll v0.4s, v0.4h, #0 shl v1.4s, v1.4s, llvm#31 shl v0.4s, v0.4s, llvm#31 cmlt v1.4s, v1.4s, #0 cmlt v0.4s, v0.4s, #0 bsl v1.16b, v4.16b, v5.16b bsl v0.16b, v3.16b, v2.16b stp q1, q0, [x0] add sp, sp, llvm#16 ret ``` With this PR that instead emits ```asm if_then_else8: adrp x8, .LCPI0_1 dup v0.4s, w1 ldr q1, [x8, :lo12:.LCPI0_1] adrp x8, .LCPI0_0 ldr q2, [x8, :lo12:.LCPI0_0] ldp q4, q3, [x2] and v1.16b, v0.16b, v1.16b and v0.16b, v0.16b, v2.16b ldp q5, q2, [x3] cmeq v1.4s, v1.4s, #0 cmeq v0.4s, v0.4s, #0 bsl v1.16b, v2.16b, v3.16b bsl v0.16b, v5.16b, v4.16b stp q0, q1, [x0] ret ``` So substantially shorter. Instead of building the mask element-by-element, this approach (by virtue of not splitting) instead splats the mask value into all vector lanes, performs a bitwise and with powers of 2, and compares with zero to construct the mask vector. cc rust-lang/rust#122376 cc llvm#175769
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MLIR_INSTALL_TOOLCHAIN_ONLY is a misnormer as MLIR is not part of a compiler toolchain