clangd 13 crash when background indexing source code in xgboost project

[zhwufd]

coredump stacktrace:

#0 0x00000000006834c0 in clang::Expr::getType (this=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/include/clang/AST/Expr.h:141
#1 0x0000000003df9ec9 in checkOpenMPLoop (DKind=llvm::omp::Directive::OMPD_parallel_for, CollapseLoopCountExpr=0x0, OrderedLoopCountExpr=0x0, AStmt=0x7febd65c3a58, SemaRef=..., DSA=..., VarsWithImplicitDSA=..., Built=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Sema/SemaOpenMP.cpp:9037
#2 0x0000000003dff0a8 in clang::Sema::ActOnOpenMPParallelForDirective (this=0x7febd45f09f0, Clauses=..., AStmt=0x7febd65c3a58, StartLoc=..., EndLoc=..., VarsWithImplicitDSA=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Sema/SemaOpenMP.cpp:10014
#3 0x0000000003dea1ed in clang::Sema::ActOnOpenMPExecutableDirective (this=0x7febd45f09f0, Kind=llvm::omp::Directive::OMPD_parallel_for, DirName=..., CancelRegion=llvm::omp::Directive::OMPD_unknown, Clauses=..., AStmt=0x7febd65c3a58, StartLoc=..., EndLoc=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Sema/SemaOpenMP.cpp:5903
#4 0x0000000003351a9a in clang::Parser::ParseOpenMPDeclarativeOrExecutableDirective (this=0x7febd45fb1d0, StmtCtx=clang::Parser::ParsedStmtContext::Compound) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseOpenMP.cpp:2579
#5 0x0000000003380129 in clang::Parser::ParseStatementOrDeclarationAfterAttributes (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::Compound, TrailingElseLoc=0x0, Attrs=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:410
#6 0x000000000337eef9 in clang::Parser::ParseStatementOrDeclaration (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::Compound, TrailingElseLoc=0x0)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:114
#7 0x00000000033829a5 in clang::Parser::ParseCompoundStatementBody (this=0x7febd45fb1d0, isStmtExpr=false) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:1107
#8 0x000000000338204a in clang::Parser::ParseCompoundStatement (this=0x7febd45fb1d0, isStmtExpr=false, ScopeFlags=4194312) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:917
#9 0x0000000003381fca in clang::Parser::ParseCompoundStatement (this=0x7febd45fb1d0, isStmtExpr=false) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:883
#10 0x000000000337f7bd in clang::Parser::ParseStatementOrDeclarationAfterAttributes (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::SubStmt, TrailingElseLoc=0x0, Attrs=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:258
#11 0x000000000337eef9 in clang::Parser::ParseStatementOrDeclaration (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::SubStmt, TrailingElseLoc=0x0)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:114
#12 0x000000000337edf6 in clang::Parser::ParseStatement (this=0x7febd45fb1d0, TrailingElseLoc=0x0, StmtCtx=clang::Parser::ParsedStmtContext::SubStmt) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:41
#13 0x00000000033845d0 in clang::Parser::ParseWhileStatement (this=0x7febd45fb1d0, TrailingElseLoc=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:1649
#14 0x000000000337f86a in clang::Parser::ParseStatementOrDeclarationAfterAttributes (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::Compound, TrailingElseLoc=0x0, Attrs=...)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:270
#15 0x000000000337eef9 in clang::Parser::ParseStatementOrDeclaration (this=0x7febd45fb1d0, Stmts=..., StmtCtx=clang::Parser::ParsedStmtContext::Compound, TrailingElseLoc=0x0)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:114
#16 0x00000000033829a5 in clang::Parser::ParseCompoundStatementBody (this=0x7febd45fb1d0, isStmtExpr=false) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:1107
#17 0x0000000003386fd7 in clang::Parser::ParseFunctionStatementBody (this=0x7febd45fb1d0, Decl=0x7febd65bd2d8, BodyScope=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseStmt.cpp:2276
#18 0x00000000032b0840 in clang::Parser::ParseFunctionDefinition (this=0x7febd45fb1d0, D=..., TemplateInfo=..., LateParsedAttrs=0x7febe67f85c0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:1377
#19 0x00000000032cce74 in clang::Parser::ParseDeclGroup (this=0x7febd45fb1d0, DS=..., Context=clang::DeclaratorContext::File, DeclEnd=0x0, FRI=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDecl.cpp:2030
#20 0x00000000032af83d in clang::Parser::ParseDeclOrFunctionDefInternal (this=0x7febd45fb1d0, attrs=..., DS=..., AS=clang::AS_none) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:1137
#21 0x00000000032af8f8 in clang::Parser::ParseDeclarationOrFunctionDefinition (this=0x7febd45fb1d0, attrs=..., DS=0x0, AS=clang::AS_none) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:1153
#22 0x00000000032aee06 in clang::Parser::ParseExternalDeclaration (this=0x7febd45fb1d0, attrs=..., DS=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:975
#23 0x00000000032ebffa in clang::Parser::ParseInnerNamespace (this=0x7febd45fb1d0, InnerNSs=..., index=0, InlineLoc=..., attrs=..., Tracker=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDeclCXX.cpp:246
#24 0x00000000032ebe2c in clang::Parser::ParseNamespace (this=0x7febd45fb1d0, Context=clang::DeclaratorContext::File, DeclEnd=..., InlineLoc=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDeclCXX.cpp:224
#25 0x00000000032cbfd2 in clang::Parser::ParseDeclaration (this=0x7febd45fb1d0, Context=clang::DeclaratorContext::File, DeclEnd=..., attrs=..., DeclSpecStart=0x0)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDecl.cpp:1731
#26 0x00000000032ae999 in clang::Parser::ParseExternalDeclaration (this=0x7febd45fb1d0, attrs=..., DS=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:909
#27 0x00000000032ebffa in clang::Parser::ParseInnerNamespace (this=0x7febd45fb1d0, InnerNSs=..., index=0, InlineLoc=..., attrs=..., Tracker=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDeclCXX.cpp:246
#28 0x00000000032ebe2c in clang::Parser::ParseNamespace (this=0x7febd45fb1d0, Context=clang::DeclaratorContext::File, DeclEnd=..., InlineLoc=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDeclCXX.cpp:224
#29 0x00000000032cbfd2 in clang::Parser::ParseDeclaration (this=0x7febd45fb1d0, Context=clang::DeclaratorContext::File, DeclEnd=..., attrs=..., DeclSpecStart=0x0)
at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseDecl.cpp:1731
#30 0x00000000032ae999 in clang::Parser::ParseExternalDeclaration (this=0x7febd45fb1d0, attrs=..., DS=0x0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:909
#31 0x00000000032aded9 in clang::Parser::ParseTopLevelDecl (this=0x7febd45fb1d0, Result=..., IsFirstDecl=false) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/Parser.cpp:720
#32 0x00000000032a959f in clang::ParseAST (S=..., PrintStats=false, SkipFunctionBodies=true) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Parse/ParseAST.cpp:158
#33 0x000000000301dd6f in clang::ASTFrontendAction::ExecuteAction (this=0x7febd456dbb0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Frontend/FrontendAction.cpp:1058
#34 0x000000000301d69b in clang::FrontendAction::Execute (this=0x7febd456dbb0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang/lib/Frontend/FrontendAction.cpp:951
--Type for more, q to quit, c to continue without paging--
#35 0x0000000001889c10 in clang::clangd::BackgroundIndex::index (this=0xabd2df0, Cmd=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang-tools-extra/clangd/index/Background.cpp:324
#36 0x0000000001888760 in clang::clangd::BackgroundIndex::<lambda()>::operator()(void) const (__closure=0x7fea50e5ea90) at /data/llvm/llvm-project-llvmorg-13.0.0/clang-tools-extra/clangd/index/Background.cpp:168
#37 0x000000000188b33d in std::_Function_handler<void(), clang::clangd::BackgroundIndex::indexFileTask(std::__cxx11::string)::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...) at /usr/include/c++/8.3.0/bits/std_function.h:297
#38 0x00000000010484c2 in std::function<void ()>::operator()() const (this=0x7febe67fbc90) at /usr/include/c++/8.3.0/bits/std_function.h:687
#39 0x000000000189d76f in clang::clangd::BackgroundQueue::work(std::function<void ()>) (this=0xabd2fc0, OnIdle=...) at /data/llvm/llvm-project-llvmorg-13.0.0/clang-tools-extra/clangd/index/BackgroundQueue.cpp:42
#40 0x0000000001887a9a in clang::clangd::BackgroundIndex::<lambda()>::operator()(void) (__closure=0xabdf600) at /data/llvm/llvm-project-llvmorg-13.0.0/clang-tools-extra/clangd/index/Background.cpp:114
#41 0x000000000188baf7 in llvm::detail::UniqueFunctionBase::CallImpl<clang::clangd::BackgroundIndex::BackgroundIndex(const clang::clangd::ThreadsafeFS&, const clang::clangd::GlobalCompilationDatabase&, clang::clangd::BackgroundIndexStorage::Factory, clang::clangd::BackgroundIndex::Options)::<lambda()> >(void *) (CallableAddr=0xabdf600) at /data/llvm/llvm-project-llvmorg-13.0.0/llvm/include/llvm/ADT/FunctionExtras.h:216
#42 0x0000000001280cc7 in llvm::unique_function<void ()>::operator()() (this=0xabdf600) at /data/llvm/llvm-project-llvmorg-13.0.0/llvm/include/llvm/ADT/FunctionExtras.h:378
#43 0x00000000019581e3 in clang::clangd::AsyncTaskRunner::<lambda()>::operator()(void) (__closure=0xabdf5e0) at /data/llvm/llvm-project-llvmorg-13.0.0/clang-tools-extra/clangd/support/Threading.cpp:93
#44 0x0000000001958d42 in llvm::thread::Apply<clang::clangd::AsyncTaskRunner::runAsync(const llvm::Twine&, llvm::unique_function<void()>)::<lambda()> >(std::tuple<clang::clangd::AsyncTaskRunner::runAsync(const llvm::Twine&, llvm::unique_function<void()>)::<lambda()> > &, std::index_sequence) (Callee=...) at /data/llvm/llvm-project-llvmorg-13.0.0/llvm/include/llvm/Support/thread.h:42
#45 0x0000000001958c10 in llvm::thread::GenericThreadProxy<std::tuple<clang::clangd::AsyncTaskRunner::runAsync(const llvm::Twine&, llvm::unique_function<void()>)::<lambda()> > >(void *) (Ptr=0xabdf5e0)
at /data/llvm/llvm-project-llvmorg-13.0.0/llvm/include/llvm/Support/thread.h:50
#46 0x0000000001958a90 in llvm::thread::ThreadProxy<std::tuple<clang::clangd::AsyncTaskRunner::runAsync(const llvm::Twine&, llvm::unique_function<void()>)::<lambda()> > >(void *) (Ptr=0xabdf5e0)
at /data/llvm/llvm-project-llvmorg-13.0.0/llvm/include/llvm/Support/thread.h:60
#47 0x00007fed0e609ea5 in start_thread () from /lib64/libpthread.so.0
#48 0x00007fed0d2489fd in clone () from /lib64/libc.so.6

source file:
https://github.com/dmlc/xgboost/blob/71eaa26c7bb564d0291a34bbcdcb606b6c299937/src/common/hist_util.cc

llvm-project/clang/lib/Sema/SemaOpenMP.cpp

Line 9036 in d7b669b

N0->IgnoreImpCasts(), N0->getType(),

since N0 in above code is a nullptr, clangd crashed.

[HighCommander4]

Please see clangd/clangd#1731 (comment) for a workaround