<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/108432>108432</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clangd crashes in background indexing
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          andy-yx-chen
      </td>
    </tr>
</table>

<pre>
    I met an issue with our proprietary code that passes GCC compilation but clangd indexing crashes, backtrace is as below,
```
 #0 0x000055d6a82f2358 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/local/llvm/bin/clangd+0x648358)
 #1 0x000055d6a82efb0c SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f7dd89f5730 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12730)
 #3 0x000055d6a863be3e clang::QualType::getAtomicUnqualifiedType() const (/usr/local/llvm/bin/clangd+0x991e3e)
 #4 0x000055d6a863bc72 clang::TypeOfExprType::desugar() const (/usr/local/llvm/bin/clangd+0x991c72)
 #5 0x000055d6a83814b8 clang::ASTContext::getTypeInfoImpl(clang::Type const*) const (/usr/local/llvm/bin/clangd+0x6d74b8)
 #6 0x000055d6a8368af2 clang::ASTContext::getTypeInfo(clang::Type const*) const (/usr/local/llvm/bin/clangd+0x6beaf2)
 #7 0x000055d6a8368ca5 clang::ASTContext::getTypeAlignInChars(clang::QualType) const (/usr/local/llvm/bin/clangd+0x6beca5)
 #8 0x000055d6a8baee08 clang::Sema::CheckArgAlignment(clang::SourceLocation, clang::NamedDecl*, llvm::StringRef, clang::QualType, clang::QualType) (/usr/local/llvm/bin/clangd+0xf04e08)
 #9 0x000055d6a8bd7cd4 clang::Sema::checkCall(clang::NamedDecl*, clang::FunctionProtoType const*, clang::Expr const*, llvm::ArrayRef<clang::Expr const*>, bool, clang::SourceLocation, clang::SourceRange, clang::Sema::VariadicCallType) (/usr/local/llvm/bin/clangd+0xf2dcd4)
#10 0x000055d6a8bd9336 clang::Sema::CheckFunctionCall(clang::FunctionDecl*, clang::CallExpr*, clang::FunctionProtoType const*) (/usr/local/llvm/bin/clangd+0xf2f336)
#11 0x000055d6a89305a1 clang::Sema::BuildCallToMemberFunction(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/usr/local/llvm/bin/clangd+0xc865a1)
#12 0x000055d6a8e52af1 clang::Sema::BuildCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/usr/local/llvm/bin/clangd+0x11a8af1)
#13 0x000055d6a8e5404b clang::Sema::ActOnCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*) (/usr/local/llvm/bin/clangd+0x11aa04b)
#14 0x000055d6aa2477ce clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (/usr/local/llvm/bin/clangd+0x259d7ce)
#15 0x000055d6aa240c09 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/usr/local/llvm/bin/clangd+0x2596c09)
#16 0x000055d6aa244476 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/usr/local/llvm/bin/clangd+0x259a476)
#17 0x000055d6aa244508 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/usr/local/llvm/bin/clangd+0x259a508)
#18 0x000055d6aa246c89 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/usr/local/llvm/bin/clangd+0x259cc89)
#19 0x000055d6aa2b4a77 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/usr/local/llvm/bin/clangd+0x260aa77)
#20 0x000055d6aa2adda6 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x2603da6)
#21 0x000055d6aa2ae72b clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260472b)
#22 0x000055d6aa2aa25e clang::Parser::ParseCompoundStatementBody(bool) (/usr/local/llvm/bin/clangd+0x260025e)
#23 0x000055d6aa2aaaab clang::Parser::ParseCompoundStatement(bool, unsigned int) (/usr/local/llvm/bin/clangd+0x2600aab)
#24 0x000055d6aa2ad5d7 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x26035d7)
#25 0x000055d6aa2ae72b clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260472b)
#26 0x000055d6aa2aef40 clang::Parser::ParseStatement(clang::SourceLocation*, clang::Parser::ParsedStmtContext) (/usr/local/llvm/bin/clangd+0x2604f40)
#27 0x000055d6aa2af46f clang::Parser::ParseIfStatement(clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260546f)
#28 0x000055d6aa2ad0cb clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x26030cb)
#29 0x000055d6aa2ae72b clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260472b)
#30 0x000055d6aa2aa25e clang::Parser::ParseCompoundStatementBody(bool) (/usr/local/llvm/bin/clangd+0x260025e)
#31 0x000055d6aa2aaaab clang::Parser::ParseCompoundStatement(bool, unsigned int) (/usr/local/llvm/bin/clangd+0x2600aab)
#32 0x000055d6aa2ad5d7 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x26035d7)
#33 0x000055d6aa2ae72b clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260472b)
#34 0x000055d6aa2aef40 clang::Parser::ParseStatement(clang::SourceLocation*, clang::Parser::ParsedStmtContext) (/usr/local/llvm/bin/clangd+0x2604f40)
#35 0x000055d6aa2affd5 clang::Parser::ParseForStatement(clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x2605fd5)
#36 0x000055d6aa2ad0b3 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x26030b3)
#37 0x000055d6aa2ae72b clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x260472b)
#38 0x000055d6aa2aa25e clang::Parser::ParseCompoundStatementBody(bool) (/usr/local/llvm/bin/clangd+0x260025e)
#39 0x000055d6aa2aa9c3 clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/usr/local/llvm/bin/clangd+0x26009c3)
#40 0x000055d6aa1f986d clang::Parser::ParseLexedMethodDef(clang::Parser::LexedMethod&) (/usr/local/llvm/bin/clangd+0x254f86d)
#41 0x000055d6aa1f954d clang::Parser::ParseLexedMethodDefs(clang::Parser::ParsingClass&) (/usr/local/llvm/bin/clangd+0x254f54d)
#42 0x000055d6aa239994 clang::Parser::ParseCXXMemberSpecification(clang::SourceLocation, clang::SourceLocation, clang::ParsedAttributes&, unsigned int, clang::Decl*) (/usr/local/llvm/bin/clangd+0x258f994)
#43 0x000055d6aa23b7c6 clang::Parser::ParseClassSpecifier(clang::tok::TokenKind, clang::SourceLocation, clang::DeclSpec&, clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier, bool, clang::Parser::DeclSpecContext, clang::ParsedAttributes&) (/usr/local/llvm/bin/clangd+0x25917c6)
#44 0x000055d6aa21275f clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*, clang::ImplicitTypenameContext) (/usr/local/llvm/bin/clangd+0x256875f)
#45 0x000055d6aa1e57e6 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/usr/local/llvm/bin/clangd+0x253b7e6)
#46 0x000055d6aa1e630e clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/usr/local/llvm/bin/clangd+0x253c30e)
#47 0x000055d6aa1ed612 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/usr/local/llvm/bin/clangd+0x2543612)
#48 0x000055d6aa2306b3 clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&) (/usr/local/llvm/bin/clangd+0x25866b3)
#49 0x000055d6aa233903 clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) (/usr/local/llvm/bin/clangd+0x2589903)
#50 0x000055d6aa220346 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x2576346)
#51 0x000055d6aa1ed3de clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/usr/local/llvm/bin/clangd+0x25433de)
#52 0x000055d6aa2306b3 clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&) (/usr/local/llvm/bin/clangd+0x25866b3)
#53 0x000055d6aa233903 clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) (/usr/local/llvm/bin/clangd+0x2589903)
#54 0x000055d6aa220346 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/usr/local/llvm/bin/clangd+0x2576346)
#55 0x000055d6aa1ed3de clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/usr/local/llvm/bin/clangd+0x25433de)
#56 0x000055d6aa1eec78 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/usr/local/llvm/bin/clangd+0x2544c78)
#57 0x000055d6aa1e187a clang::ParseAST(clang::Sema&, bool, bool) (/usr/local/llvm/bin/clangd+0x253787a)
#58 0x000055d6a9ea8591 clang::FrontendAction::Execute() (/usr/local/llvm/bin/clangd+0x21fe591)
#59 0x000055d6a953b5be clang::clangd::BackgroundIndex::index(clang::tooling::CompileCommand) (/usr/local/llvm/bin/clangd+0x18915be)
#60 0x000055d6a953c8e9 clang::clangd::BackgroundIndex::indexFileTask(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>)::'lambda'()::operator()() const Background.cpp:0:0
#61 0x000055d6a954534c clang::clangd::BackgroundQueue::work(std::function<void ()>) (/usr/local/llvm/bin/clangd+0x189b34c)
#62 0x000055d6a9536390 void llvm::detail::UniqueFunctionBase<void>::CallImpl<clang::clangd::BackgroundIndex::BackgroundIndex(clang::clangd::ThreadsafeFS const&, clang::clangd::GlobalCompilationDatabase const&, llvm::unique_function<clang::clangd::BackgroundIndexStorage* (llvm::StringRef)>, clang::clangd::BackgroundIndex::Options)::'lambda0'()>(void*) Background.cpp:0:0
#63 0x000055d6a95d2755 void* llvm::thread::ThreadProxy<std::tuple<clang::clangd::AsyncTaskRunner::runAsync(llvm::Twine const&, llvm::unique_function<void ()>)::'lambda0'()>>(void*) Threading.cpp:0:0
#64 0x00007f7dd89eafa3 start_thread /build/glibc-6iIyft/glibc-2.28/nptl/pthread_create.c:487:7
#65 0x00007f7dd859e06f __clone /build/glibc-6iIyft/glibc-2.28/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:97:0

```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzsW1lv27gW_jXKi9BAIkUtD3lw3XpucNtpp84M5s2gyCOHNzLpoajW-fcXlLyItOPYbmYP0CI2F-s7H88mkoc2jZhLgJuAvA3Iuyvamnulb6jkj28eV2_YPcirUvHHm9twASakMhRN00L4TZj7ULU6XGq11AIM1Y8hUxxCc09NuKRNA034w3gcMrVYipoaoWRYtiZkNZVzHgrJYSXkPGSaNvfQBGgclpQ9GE0ZhKIJaROWUKtvARoH0bsgGgVptP7XfQ0DhKMwWkVRFBHCU5qjCmGSh3X9dRHgUYBHzWPTf_ishTRTQ9nDnf35AOW7QZp-m6nGaKCLAKUWhpAmQEUYoDxAk7bRAZrUitHa_rXT0KQUMkCTXpIAvY1WaZJjkgeo2GGLXWxQlRELp2Iuaf0fKnkNOkD5-lF9c3PNlssAj6Lu__aH0PqHsirjPC8qkuEonM00NEZpmGmzRlqLMkCTVZ7O0uRNLWS7ejOXbd-xNPcaKL9u1HXUAY5RhiMHL3bwprgEDP1i9Tz91NL67nEJ_bc5mJFRC8F-lr-1tBaVAN71WihFyJRszFkMFkUMGBxEiY-IZWiIyD7vU_V-tdQ7XByadk7198BgGXJgEAcGzuOkzIcwRtO7sZIGVmZLjcVzKyt1u1jWAco9zD2sAI0ug5jyLCldXUtdiGlOK3QixJeHVwKtXAYzHx6j5AR4o1rM5a0c31PduDC3ungpQkaJgzB3EJYUIHLWeAoL2n8a3wN7GOl5B24B1n6HyKaq1Qw-KNY5POtNBp0_0gXwd8DqjtzxwFNNjRZy_gUqb8ZO0Ceaz3NTVZRA5KpO4UrOM8aTw5IzK_mY1p5G-0INuiatZJaGz1oZ5amWM9DasNO3Y2akNX20xODxkxPw-y56KFV7v3t0NfrOL1TOfXp3Mv9CtaBcMCv2RYQjzniyJdyGhcgjvMA4PaJqGw73id_0HObejrcsnbcq50pXYZw60rlRr8ARofFh6d62ouYdr-ojLErQG1yeQTFlaT-kMfut--u9U6SPraFlDU_r006TTtWgAYiN8vV_z6OR5SmhsUMjcmgEgmj1HI09mH8ZdXFMc1q53GGPuyRKysPcjZj5JP_G3J3NFY2S0uHKSbEoSrKMOUnfZ6ob0IPPn1VjKrGyEKBphJLTtqrEyiVv1NnxF2ja2hwWGI1Do1voBD9PCkQKnjFwpCCeFBGLiqNSjGljdiK44IeD7bju-3-F5Pu6mnoLM5xqHaudPjXUwP7Us1cPkSJlUeHInXpyJ0mW_r5y_3HC0iRzI0vmC0vcFG1P2FH3amtTtFNE9kQ4Hy8ZJFYWb-7hTVl-XCn_CJSM5a4KFS7KMqFZ9izK7un7ue_eWD41C7PJ7M8Fm0aUZtkQLIpcsJRzelzft0A_aZslUd2501FlQI-M0aJsDTTObsB0Qev6F2BGaddzWVHWngujtnNcx8z_gPxHHbwfUvr5Q5AHn-aPOJtjzKljZij2OIYMlRdw_Fch9WxCkgw5IRIhjxCKyPEQOVaLpWol3xLzVvHHAOWX5DcojSJEnGiHsA-I0uMrtAdoC2YctrLb_-OXbHpZcJS6bCW-iRJ-3J-8muizJkq46wbJq4m6Spf6hFRJdBohxzdvDq74Cwa4pEoiRxAvx6FVklZHAdxWp4tyNjySpJUDL_eNO2KXKN6rcQ-MO2KuLhevxu0Qgv2k78-Ov9jPkP5K8Rf72cpr_H3x-Iv9BOxfb6J-0vd3jb_Yz6yqipOjACbqqZfhFwnAFScOPj_R4VGJX637OwNwiR2O_RzsX2_dftb3pwdgP0WiBTtuBZuTJR_QYM7hQ7T9te6PBS5RtKhgjqIlbmITV0We8qMP_wAr4B_B3Cv-Dqqn994G4y6BSpIqT7kDNfahkuQcqM3xfUIh5-OaNhcZMEkqkrhgvRQIF0WRHNfXX3_tTyCnS2CiEhvrOflc_2jnE47MTfycGVtdPJeLvCoK57A58VIVXGbsmRMCuxBrHsA7EzPqof9wpx5Abo4GTuXBSmV_-BQPdweLZU1Nd0FlczrtzxoxBg7UZ08pNggO-86XCCekiDPm7KcmXm4Uo4wcf6UfxJCtcM2-s_qdqbycwo0TogZ2lH4Qh6593C6WtWCiu-wj6QIuzeRImmfE2apI3EwuBpLBccW3kn3SuzsV1a00oCWtD_iu89OSvRFCzp9exb31OJcPXGbgqmHq8ZHi6HgQH6ihQ4uQYt87_i6s-Nry_awwHDmZRJJ5rPA0Rs-cfvVK4SZ6fwATZ4dFnMbIkdVL43CUPvPucCsl6B_pApqlf2f2yXx2-CPu_P6u4ThMbJbrOKIjkdAPKOdz-ZbWVDLg76AWC2FA32nKHqz2XODd8zR1XxYSLxXFuIiOkzrk0_PoVp-UPi2x98X0-8-WrCgiRzLibbuhyPqQEx3Gy8r2Eib1_S9GJEtx4vhUEvveA_PjPvVv5D0wdzwl8ZPqV-_x_d6D-Nn5P8d7JK_e4znv4Weo_2Tv4WefwLLjd7fu1PIDfIW6fxUeCvlpSX9r4bPxXIcd-INW7bK7Y3lgG2136_Oj4m0Nt4ul0pt7VJfsOyQscy58ET-ZjPOM7gk5mt55GwsWV4_2ey7CIoKzPKMOICfjK4DmpHAuEU-0tSjJ--uafdv7FbDWbMp4zkIQV0AK5youcdKjguCSlI6Or6evfS17mGvVSn4rOaz6xq5KzN-FULXYfBl3xWUwVosFlfzsG7F5EZPSUdU08iCzHIrzIU9EDXe0eQhQ3pj16NmMrVZx3H8paSPYrOnKPqwm39PutXs72DbMjKbCNJvu_pLwdgStrXjrGLru767T9t0Bymq6KDkNUNavZt-ultB503XbsE5qJ85-IZqlJnapSQhO2PPU_NRCuy7O-qa0w0i1ufGPx1-V4OEG59mXguO8KHHCnIVE3kKmuIjC7jG7TISDoaLuP_8sxW_tdqv4LW1gDasjdrQuqegquhzP86xC-I2ONg9n33U1eg2tYDJ9aqtmOP6HWpW0Hu_qK99RQ0vagDN5J23bSTgbsH6aGFOjNJ1DgEahm8ftipaK_Svsz_LyaWlRNPsaGw1U9n2A8m4R-kD0nIpid9E5yggJ1_MHTPTVkEPWP2u1egzweKubpl3W8DRFo-ZRMmvhX1qbqPaNupVdu8PS3TchT1-RPTs4yo1PTy-LkPPD7CRuJSnQiuKwMVSbWc9IaI2rFTUP0GRei5K9ScXtY2W2X9F1Z5Vyaaw5rqtKZ0wDNXDNAjxK8izAo2z3TOI8kxQQpVU4m7FaSTj1cQvRsABNrq8DNGkeGw7LxroGKVZ9w9euyFW2q239a-celITraYBHRTagwS0lvuI3mBe4oFdwE2cojVNcxNnV_U2VFYgC5WXGkriEKIlLhhBDgDAkRU6uxA2KUBIVMYozkuPsmsQoKzNWYCh4wYskSCJYUFFf2-W-Vnp-1VVO38RRnmB0VdMS6mZTdq1v7Kg3ZTtvgiSqRWOa3TwjTA03vfZtyqVDIbty6d4YttXUV62ub-6NWXaFz2himRTmvi2vmVrsHGj3sKVW_wNmye6AWUrX2L7eoP8HAAD__4hP6w0">