<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/67690>67690</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang] Crash from constexpr-evaluation of structured-binding variable
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:frontend,
            crash
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          hazohelet
      </td>
    </tr>
</table>

<pre>
    The use of `&c` at the end of the following code causes clang ICE.

```c++
using size_t = decltype(sizeof(0));

namespace std {
template <typename T> struct tuple_size;
template <size_t, typename> struct tuple_element;
} // namespace std

template <typename T> struct std::tuple_size<const T> : std::tuple_size<T> {};
template <size_t N, typename T> struct std::tuple_element<N, const T> {
  typedef const typename std::tuple_element<N, T>::type type;
};

struct C {
  template <int> int get() const;
};
template <> struct std::tuple_size<C> {
  static const int value = 1;
};
template <> struct std::tuple_element<0, C> {
 typedef int type;
};

template <const C *p> void f() {
  const auto &[c] = *p;
  &c;
}
```
Live demo: https://godbolt.org/z/918oE41Ke
Backtrace:
```console
clang++: /root/llvm-project/clang/lib/AST/ExprConstant.cpp:3381: bool evaluateVarDeclInit({anonymous}::EvalInfo&, const clang::Expr*, const clang::VarDecl*, {anonymous}::CallStackFrame*, unsigned int, clang::APValue*&):
Assertion `!VD->mightBeUsableInConstantExpressions(Info.Ctx)' 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: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++2b <source>
1.      <source>:25:5: current parser token ';'
2.      <source>:23:32: parsing function body 'f'
3.      <source>:23:32: in compound statement ('{}')
 #0 0x0000000003708fb8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3708fb8)
 #1 0x0000000003706c7c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3706c7c)
 #2 0x000000000364f8d8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f76867d4420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f768629700b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007f7686276859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007f7686276729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007f7686287fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x0000000006f80225 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6f80225)
 #9 0x0000000006fa9b66 (anonymous namespace)::LValueExprEvaluator::VisitVarDecl(clang::Expr const*, clang::VarDecl const*) ExprConstant.cpp:0:0
#10 0x0000000006fe7e9b (anonymous namespace)::LValueExprEvaluator::VisitDeclRefExpr(clang::DeclRefExpr const*) ExprConstant.cpp:0:0
#11 0x0000000006fc4837 clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::LValueExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#12 0x0000000006fe7eb6 (anonymous namespace)::LValueExprEvaluator::VisitDeclRefExpr(clang::DeclRefExpr const*) ExprConstant.cpp:0:0
#13 0x0000000006fc4837 clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::LValueExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#14 0x0000000006fc5d8d EvaluateLValue(clang::Expr const*, (anonymous namespace)::LValue&, (anonymous namespace)::EvalInfo&, bool) ExprConstant.cpp:0:0
#15 0x0000000006f9a14e Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
#16 0x0000000006fb8e42 EvaluateInPlace(clang::APValue&, (anonymous namespace)::EvalInfo&, (anonymous namespace)::LValue const&, clang::Expr const*, bool) ExprConstant.cpp:0:0
#17 0x0000000006ff4208 clang::Expr::EvaluateAsConstantExpr(clang::Expr::EvalResult&, clang::ASTContext const&, clang::Expr::ConstantExprKind) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ff4208)
#18 0x0000000006eaf122 clang::computeDependence(clang::UnaryOperator*, clang::ASTContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6eaf122)
#19 0x0000000006f623f3 clang::UnaryOperator::Create(clang::ASTContext const&, clang::Expr*, clang::UnaryOperatorKind, clang::QualType, clang::ExprValueKind, clang::ExprObjectKind, clang::SourceLocation, bool, clang::FPOptionsOverride) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6f623f3)
#20 0x00000000063ffa0f clang::Sema::CreateBuiltinUnaryOp(clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ffa0f)
#21 0x00000000064004ed clang::Sema::BuildUnaryOp(clang::Scope*, clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64004ed)
#22 0x0000000005ed5bf9 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5ed5bf9)
#23 0x0000000005ed7d8a clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5ed7d8a)
#24 0x0000000005ed7f29 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5ed7f29)
#25 0x0000000005edcc29 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5edcc29)
#26 0x0000000005f57dc7 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f57dc7)
#27 0x0000000005f4e43d clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f4e43d)
#28 0x0000000005f4f278 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f4f278)
#29 0x0000000005f501b9 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f501b9)
#30 0x0000000005f51ada clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f51ada)
#31 0x0000000005e7f1c1 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e7f1c1)
#32 0x0000000005f6b520 clang::Parser::ParseSingleDeclarationAfterTemplate(clang::DeclaratorContext, clang::Parser::ParsedTemplateInfo const&, clang::ParsingDeclRAIIObject&, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f6b520)
#33 0x0000000005f70a18 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (.part.0) ParseTemplate.cpp:0:0
#34 0x0000000005f70cd3 clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f70cd3)
#35 0x0000000005eaea0b clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5eaea0b)
#36 0x0000000005e79814 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e79814)
#37 0x0000000005e7a71d clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e7a71d)
#38 0x0000000005e6ea5a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e6ea5a)
#39 0x00000000049724d8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49724d8)
#40 0x00000000041d6509 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x41d6509)
#41 0x00000000041571ee clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x41571ee)
#42 0x00000000042b584e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x42b584e)
#43 0x0000000000bdcb46 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbdcb46)
#44 0x0000000000bd440a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#45 0x0000000003fb4a69 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::'lambda'()>(long) Job.cpp:0:0
#46 0x000000000364fd84 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x364fd84)
#47 0x0000000003fb505f clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#48 0x0000000003f7d3a5 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f7d3a5)
#49 0x0000000003f7de0d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f7de0d)
#50 0x0000000003f85d35 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f85d35)
#51 0x0000000000bd9fec clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbd9fec)
#52 0x0000000000ad4d61 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xad4d61)
#53 0x00007f7686278083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#54 0x0000000000bd3eee _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbd3eee)
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkW99z46iW_muUF8opCf30Qx4cO7mbudlNtpOZfXQhceSwLYMWUCaZv34LhG0hO07SE3f17r2VvmMbOHzfx-FwQIgoxVYc4CJIL4N0cUY6_STkxRP5SzxBA_qsFPT14vEJUKcAiRoFWRjgrAqyEBGN9BMg4NQUmI-1aBrxJ-MrVAkKqCKdAoWqhvAVuplfnQfhIghn7v-zsP-rAnxp_uyvnTKtFfsLlhoF8QJRqBr92kKAC_OrqANchAGemr_4cmiQkzWollSAlKYoyF2hhnXbEA0oiOfGkKmGHoP4Ciktu0oj3bUNLI3xrcFhmx5LgOdo03qvLTSwBq53ePIFCvB1gK-RB2qI9l1Ypn48C-LZEN-8Elzpvl4Qz96o1Bfnl0G-OEIJ_ceQ1LG-t_zmtskQw0ZlZA1RqF3p1uxxU8aIK35twbYaqjgaYYdu7nU74MWM4SvEuEYr0AEuAjzt8Rw0Omz6rvDzEV2liWaVY2t6fCZNB9Zlo7_R206f0Ogz6nWjsenvHa2G3fUg5yjAs9YYfBaMotrpM-DU1yOdFijAWZBeVkG6sJT6ltuKNgIM-_ZndP_1lj0DorAWxlGftG6VIWqnxUrQUjT6XMhVgK__CvD1NCrEVRL9E_q2l6T6riWpwDQZhQvBlWhcPRtaXPyIZ2bSSSF0gK-b5nk9aaX4b6jMV1fvumFlgK9nD48Bvr56aeXcMCZcn1dtG8SzOC4iY6cUokFgRpRo-IPIBVTNDWfWpfJLwgV_XYtOWdXN2F09k-aG18Kotp0gfZ99-UsrAzw7WObMu-KD5uekaR40qb5fSxN--podt5GbGmewhncmZ_d_GGe0FTMbKJ2IM6VAaiZ4H8ajPxaTIL5as9WTvoTfFSkbuOEbTQxoUIoJrgJcGHrnc_1iQ2-OasIaoC6g399ezR6ukOrKNdOIoLJbIQmtkBppMR56pp-68rwSazdK-4PFlOpAmehJuKFXNR0Fu75UkqgnVG6dA89RK6GVogKlgCIlOtn_bFoSpUTFiAaKZMeRqiRrtYNs5US0W7dbccLzIJzeS7GSZI2IXHVmIirnVqK1biTWLWtATuClbYQEuXGtCdkoqyZadvx7gK9LxneeZzwUTVb0TyLrSYImKzQxk-yatK2x3um20-cKTdZGCzSZvBTZhKj1RL1yTV6CeMG4hgZNHtBksqqqiRaiqZ4I40G8OArPVFactOpJaDSpK9EIOaGMrLhQmlUKTWouJlZY_2cbmBZuccalXTd6eeOrXrDICOb9HM9wGsQz8w9VnZTANWqJVCCRFt-BowDnJm7gvLeAD1mIzUTExoRpatKBuuOV9VqTjBgb9dZCfNwC48iIIjpObcS2wRXZyJe7BRLnxqX7wBbgOEThS7j5X5yHRV0WyPqpnVrqVfUf7iXj2nrRY--Kxa6SJH8uhdISyNpFBDtHp33HX-JLAb4MXxw8D380wp9VeXUI_7wBwrv2jj-wFSdNgIttQGmE6eUUaA0YDy320GZJXdACzY0zfoNKPIN87eH9G-G0MZ0WTkmvzlxwDS-bIB7af9suYtdFXudZkeU0SXCIlksJSgsJS-ncwS0NL0W2zJJJw3j3Mlnxri9o9ZMEQs-VOA8tl8hY8ZgkXjd4modhiSRhCj5gvzKWM2s5icOw9CynvuU8K9IpIqX4EPKBZYyLdOpZzsaW8-2of9hmjn2buW-zyGuafc5mHNc082wWQy_J6iLEOP1q73RmvX6nfr9kWmaWy3aF3qX3bpWNZ7d26TVr51WfPwjp1nmmmN4u9sUoO3BpqssR9rKDQfEUHUhcBj5vYkDoA4ccpuXfA25AfIO6T2SG4AcFnwQZ-SCrpIjzIfUHvda2byEviTI5-C6Mrcl3WNrulq2WNnH6PDs8t4nedgtiO_PZGQyfpIX3tC__ptOcQPv4_6f2yYhWSguKXKdw65Lio1PvQ1Tcov5O3dGmwNL9EIvUZzElUQJbFj7-bab_A4DeluEjIDMfZFlAgrcgb_h90ydFX4T1Q8OyYfAOu88MRe6zrBMcFnsbuy1gQ32mhvunfW_b1f4GqmsOwJ09PLqE5hghl8UN-von43R74PH1y6Plvl0ejTj-sgykjjAewjTddhoW0AKnwMf-8Dsn8vWuBdkHhPHKd1CGL09KHWyP12jZz3Bcx-hN4P04SNifmx8bxz3invl-UL3y_-xI82hPRPeM2WlwoIkpuyvN9vpA4YPdOt2KihjBdvPDq3R9f9daPe-eQUpG4RRj0Us9HAvsZzJxXZOw9sDDmgyH4LJjjWbcaThaUPaIfkL1wVhtwsdX0-_ZefT9HCkJwwToYfqGOD1MuxIt7LvZr65GT9ZTw0utUqBpWU-HqO7tUcPg85yowTGWL8uwsqlnv2-obmZA_9_xvB02NTPRNH_QNgCMm85OII1j7kkTj6TJaUFOK80vpYeh6-mRjPWo8XFXmdkHYWvgH1JlxPIklGrsD3E6olRV71D6RYgYnB4RL3VM6zSnVf4ukYfN6d3bXOxnarYNbt09BZ8erscn9_kkkMT0KJ8tlzu7uSfShuBZrUHOtJas7DQo70TxYU2a5g-obMIxH22SXCCOcWe2U0ej1QGJji4K40Wjbz8EebC3cY0TDINV2RuGYjQMNc6LHxiGX0X3U2hmJPE0m46mYhiV76yo7jR9q92loK8BLk6UBThIQ8z-CX1apxGhx5e6a_f4YIx5dJLyhrd7HtOnUqfxaEvEYxr5ET-voyr6ENMF1IwzfTDyM77aeLvZdr3vtY_uSbLZjr-1kxm2uiUadlHglm0PFb58abGCeIr5GWKdlSkOj48o46sGxlF4Q3nfSXrZDk_iH5fOjcm32c1Nv03brzaOEB-Ku_6GuqpAqYcWKlYzI_gJfNgK7o2In5jWeUii41F5o9lgTO6kRU0a9hfZd-r3huVUyp23ROpzwxZ5wA-eJMXJWIeKxkd1GPB_0ERqxlf_xfTTj7nm_w3vsaJ43jPKeQmQsPyoaj9bofdr_JRVvhfJUzEbrSPTIkreSbg1SE6aN9X8CjUGgc-41ckWCcPWkyMfyUHy6Hi-_ijaW3iGZv_R3V1L_qeDez3KDk3Ff0jRtd-gPpgb7s5t_l3QroGbdSvkZhN2kvSip-np4CfMkAFJ9xMpe1eqGEMfPtI42RGQg-Rh9hLWZJrjhHrLyVxQ-AfwmU2DNmdVUHUa3E_u0tvXInVAhkgTL01NIpqloZdaX0sThzg9APVEIHsMHsjIB5nmEYAvZ9_tjX3M0F_H21f0bVYn8WWH0yPiJX4JLtMiAf_A0kLe8XneRuHiGN-TBCWHzyPg5UlhSasyyVBVRcs1Yf6edCYlebWBZV49kcGTLRNo5sj_Dc_tbc_T8OhRejSSEY0kCQnaiD-PHm2kOLzBvlm3zUFONtbsmhgbh54MUcmeQR7MvhIvj4jrMiHZtL8Gu7O7uWW2lFZbW9rPxO1T6oo0TUmq78ua-wG_79v50Dyai_WacDqe1AfHcHsBWNgHLKTxHrY_aMn4yi0j_QBvGyyX1ctLFPVfSqJYtVS2ulPRq2x-WGpJmFab4pE50jRmTvQnHa7cVJmNTm_dhWrTJMB5Q9al2bbmO6lwsblB9psoD49HNr73RYtkMBSHbnf1Jd86_kBqaF49OY8P3QmusvWIPc_PRy6Whqn3pOpfzkVGe6Q3faHwhctpTNI3hbNjR_ZWzI2aXjAfNTQV3tqEH6k6G93fOMnjdUfbc6jpWBcI6Wd1-U2U6m1RfhPlLVP-4-ljoXnrBy1h0r1v8QkdnbP8HDUh9JLd1L_XWxcpjd_0ssXgs5c4HMgY3hqFn6jm14e3Xh5Pv2i0sE9rqHqsmwxlg9-GlZkLCu8v21-ekxhkHnQvNwwJTWgWIQP6q_vuTXt9x6MrtkVYxGi5bFhpIjGRejkA8tFLt0lYeMck6TjrigEA9fa_Xl9jfNf75rWcM3oR02k8JWdwEWXTdBrhLIvOni4oziipCM5TDIQSnCY0TAucR2md4GlUnLELHOI4nOIiStIojM6LdJrWeUVpGda0nOZBEsKasObcONO5kKsz-4bIRZZn0_CsISU0yr6_iPFm8tRuGxJgHOC5KTAZhfmWLs7khX3hpOxWKkjChimtdqY10419G7I3lS76q-aolmLd-y28tHLiXg5igiNRu3e5Ogl0UjJOGV-hZyIZKRs462Rz8eOvwFiO_xsAAP__69-4dw">