<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/131709>131709</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            ICE on variable template initialized to IILE containing fold expression?
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

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

<pre>
    https://godbolt.org/z/YM7vGETxY

```cpp
constexpr auto call(auto f) { return f(); }

template<int> int zero = 0;

template<int = 0>
int magic = ([](auto) {
        return zero<call([]<int... i> {
                return (0, ..., i);
        })>;
})(0);

int main() { magic<>; }
```

```
clang version 21.0.0git (https://github.com/llvm/llvm-project.git 4b86a7f3860a3cb0368e308494f65c103c02fa18)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-trunk-20250317/bin
Found candidate GCC installation: /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1
Selected GCC installation: /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
 (in-process)
 "/opt/compiler-explorer/clang-trunk-20250317/bin/clang-21" -cc1 -triple x86_64-unknown-linux-gnu -S -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name example.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -fno-verbose-asm -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debug-info-kind=constructor -dwarf-version=4 -debugger-tuning=gdb -fdebug-compilation-dir=/app -v -fcoverage-compilation-dir=/app -resource-dir /opt/compiler-explorer/clang-trunk-20250317/lib/clang/21 -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1 -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/x86_64-linux-gnu -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/backward -internal-isystem /opt/compiler-explorer/clang-trunk-20250317/lib/clang/21/include -internal-isystem /usr/local/include -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -std=c++23 -fdeprecated-macro -ferror-limit 19 -fgnuc-version=4.2.1 -fno-implicit-modules -fskip-odr-check-in-gmf -fcxx-exceptions -fexceptions -fcolor-diagnostics -mllvm --x86-asm-syntax=intel -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /app/output.s -x c++ <source>
clang -cc1 version 21.0.0git based upon LLVM 21.0.0git default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../x86_64-linux-gnu/include"
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1
 /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/x86_64-linux-gnu
 /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/backward
 /opt/compiler-explorer/clang-trunk-20250317/lib/clang/21/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
<source>:12:14: warning: expression result unused [-Wunused-value]
   12 | int main() { magic<>; }
      | ^~~~~~~
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-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++23 -v <source>
1.      <eof> parser at end of file
2.      <source>:6:5: instantiating variable definition 'magic<>'
3.      <source>:6:5: Generating code for declaration 'magic'
 #0 0x0000000003b6ed88 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b6ed88)
 #1 0x0000000003b6cecc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b6cecc)
 #2 0x0000000003abc748 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000791af2842520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000000000354a452 llvm::Type::isIntegerTy(unsigned int) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x354a452)
 #5 0x0000000004136645 clang::CodeGen::CodeGenTypes::ConvertTypeForMem(clang::QualType) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4136645)
 #6 0x0000000003ef1db7 clang::CodeGen::CodeGenModule::EmitNullConstant(clang::QualType) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ef1db7)
 #7 0x00000000040c0f2b clang::CodeGen::CodeGenModule::EmitGlobalVarDefinition(clang::VarDecl const*, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x40c0f2b)
 #8 0x00000000040e07e5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x40e07e5)
 #9 0x00000000040e12e0 clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x40e12e0)
#10 0x00000000040ea7d7 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#11 0x0000000006d1a8e8 clang::Sema::InstantiateVariableDefinition(clang::SourceLocation, clang::VarDecl*, bool, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6d1a8e8)
#12 0x0000000006d1b6a9 clang::Sema::PerformPendingInstantiations(bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6d1b6a9)
#13 0x0000000006269e49 clang::Sema::ActOnEndOfTranslationUnitFragment(clang::Sema::TUFragmentKind) (.part.0) Sema.cpp:0:0
#14 0x000000000626a5dd clang::Sema::ActOnEndOfTranslationUnit() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x626a5dd)
#15 0x00000000060cbdd3 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x60cbdd3)
#16 0x00000000060ba33a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x60ba33a)
#17 0x00000000044ec32d clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x44ec32d)
#18 0x00000000047d0191 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x47d0191)
#19 0x000000000474ebdb clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x474ebdb)
#20 0x00000000048bffc3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x48bffc3)
#21 0x0000000000d638a1 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xd638a1)
#22 0x0000000000d5c09d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#23 0x0000000004539629 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
#24 0x0000000003abcb63 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3abcb63)
#25 0x0000000004539849 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
#26 0x00000000044fcb6d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x44fcb6d)
#27 0x00000000044fdb31 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x44fdb31)
#28 0x0000000004507ecc clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4507ecc)
#29 0x0000000000d60671 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xd60671)
#30 0x0000000000c21cb4 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xc21cb4)
#31 0x0000791af2829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#32 0x0000791af2829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#33 0x0000000000d5bb35 _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xd5bb35)
clang++: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Compiler returned: 139
```

</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzkWk9z27iS_zTwBQUVCervwQdGsvI8m-xkx3559U4qEGjKWIMAFwQVeQ772bcAUKaoSEk8pUylal1OTIKNxq9_aHQ3QLKmkVsNcIsm79BkdcNa92Ts7R3_s4Dnm8KIl9sn5-oGZTmia0TXWyMKo9zI2C2i6z8RXf_742z3_u5x_2-U5P53msRfXtcoybnRjYN9bTFrncGcKYXoPFyXiC4wmr3DFlxrtb-fI7pA2TuMZquozUFVK-YAZUupHcrusNQO_wnWYJStcIKyd-cEDw_vUJL724ptJQ-NfoxgaoeiwxCULDogXj3Klh3WTjzoHY1GWHoUr136XojOE0SXeDQa-T8ymtJJzVbh9q5ribehw6tQB1TqSENgJuBG2TL2PNByYPiEcM-2YnqLd2AbaTSm6SgZJVvpPLaTaZTuqS1G3FSIrpXaHf6Q2pr_Bu5Gvte4mE_ZrMzm04RlvEiy6RyyZD5ejMvphKdJxhNasjRMWpI_MrsFh7Ic7-fTzXRMWv2szRdNlNTtnmx164WeLDCBKyNAedHaNHKPkvxeN44pBWIlrW9HdG1qh-iam6qWCiyBfa2MBevbvJXE2VY_E5rQSZKlM0TXhdQoydem1QJzpoUUzAF-v1xiGbUzJ43-rvYt56TRrG6ejBdRsoiNiK47w3qD6DqdjJJRipL8ARRwB-JvG3D5amLVKid9tyzHI-9O46Saji-KZLSTyehFmf2r0D5IvVp3cSzvY1J7_-HQNNElMKL0r87k4SFNEaWYcJ5i4qysFVz0L0weMBGyYYUCUloATLgCZglrHCmgNBZIwfgzaNHLBa_fgZWlBBuaObOC7JhqgWhWQYOJX5WklCo2YNizqlYw4nWNSWVBGR5mmgS3xrXkmNSSEwU7UJjGG9mQWgImVWlZBaQ2UjuwKFsxpTApK-aeCFirDSZlWRNutLOMO5StjMak1IZY79lSb4mXjU07sIVpgLCmwqQKsda23BlLmJKs8djLVn-RWhDnrW1QtqKYuLBUCa9bzyWZjjFxrYbQsAUN1lsgoGi3ROrSkGepBcpWR_oxEV-YLUkXalC2Gnc9tmC9Mqm3KFttRYFJGTXF-Y9ECb_KV4iumadwh0nJzQ4s28I3xCw0prUcfPNfChBxZYWHiK5pikmYA80Ukc1L46D6CQuVrn0-OP1Paq5aAX4gRN-F367DLwnqjLJfFadf4F-YFW_F94M-0w9_foC28cp8RFDfE_1buDoj_zUo2PsL_rUdPdPfmP4zvd8-BCaNCzEmzijNQtyoLXDmQJCKcesjI1hrLFGykg6nC0zKrW75cRQaUb-EfGyUVa0kl85H5VaFUNg8y5oYYQl_Av5MpCbbqvTBZ78nsOdQ-6jjBQc33ChjiZBsq03jJPcJwWcNTIiPnqypSPOiHdujbOXt9eGcCWEbucVktdm8Xy43_8g_321W_8r_WNPNcn2_yR8-omyVYmJwDG_eH1pXt27UYLLHHQ0YZcsY9GItG-u7kAy_LvIK1oDAbW00_vDh88ejJwJK1iqHY9z_Vn0mt9pYqbdYGw172TjQDgtpwQf9l-_m87_FcT2IH0Q66IFodnA2RGko0ylugFn-hBvHrGvwE1jwNfJQOFt64ezuovCvEPl-DRRnlP0qwA6J4buA3pwJOo1nQ__g2eVwelYsye-0wKY8-J2SjRt53zwOClmeUv_f2FfkX5iNlVeO_Z4bmhAiLDR-9be69QECTd6Rf8XrWOX63W2SY4xTitFsiX90H4rDj--BJnf_G35Qkn_6cJc_3OGmLXyMZrhot9hCbazDzuC37UI9F03TQoPoGjMt8GFJuifA3LLmCftZ9YUy-D13baHbf4DAHUV0GXqypjFc-lyCbatxw62sA5kPjvFnLNqqjms5GaFk8cmarWUVZnbbVqBd85Y96XAD0wVyso0F8xiT7YWo_92kclrwP2BC_Opxxij-5GcsFMs_ttTOJzY_RiB22PxVbt6dZqbU04ayJZjSR8qa2QYsZg5DdGG_e0JJTjuxY_-doiyfeILDrlk7yZyP6ztmpd-z-OwltfTZGCM6O3ZFOkNJnn1L5Xu_m4n6uBGAS2OxAK6YZUOFQRVGNEtwsk8OP1kxBTGf4-CbWY6yvHlp4sUnK7ULzvMY3W_eC1n2ZWMaZ4FViE7DaZB2YS35JfXXvQjRd8m-w_S6w87SE8QcOD-HeKmA6bb-XT_IrfYxat7qcPonsDJ-iKvh8wh6fHSAjxV8Np7jpXeyPyBs-14ioH8wLZQfZt6xNZBZGu1g7_ymG2V5Ev5F_Vmnf7ZIWUnnYzqhSWdJjNln0oiSBR81ZjQNkEOXHvB4AHgyZuMJPSL08aWGeCWbe-1gC_bx5ZjNDn7YLl-H0oihRzg5RjhOs-l0PMGxV5xqI-A96MGNh33wBKN3YJ1vWRv7ESpE50e9_6tlKhh5JY_oAPbwpwOCoUxFMfse_I-hio9Nd5V0_9kqtTQxYvxc-B3AHv5swH7Ck5IWb4X_XpmCqc_Mrl6j29CK8Iir6EWI5j6KFMaoq01KxN1bNR9aBckMvutT5626ZNLhKVfemH5BHbjwtYg39FoGBhN6AxcnBqYUkr9m4GWzrgbdg4vQfYRPTqCzmXjzgnk09QfYQQf02IDYciB-VDPrRkkIwMeaTiKvhzXIPFORsjnMj2E9QMXi1f1raofPXV6_5CUPIY9_6M5Uvad8vSoG6-H073XmoDOnnwN6YmwxZYvzxn4CWxpbfYJwXNubLo1uEJ3_JLQeT482G6Cl0wWML6DNuftd32nxe_lomW7i0es_tXRry7a--D2ZnteOj_88SPyH1OJr7_GSZ5xmfIKMTYR4I7LDzuQaxEUAPXGD1DpNeCFEdgzvU6hsj64vr6vfa_Y_LXxyFmXLk-X23pq2_gPKUMVOT5y8ZyCuvPvKb58eHHMQhK9kebStt3w6tLxgWca-sjx_eDzjD9GEn-LYEUePcph8x8AzKs6Ewpx379589NsDbx10TdfznW70Htswhc5Eki7SY2xr64tYLc6AuyasOHAPa5j4ZmMoxEm9EgeKkYrDedYu23E9n-zAvUKnw8Q3L8qSD1ZjB7K3YPeaN-bfsvCKZUYE1UMeJMVETLM5SzHn6aY7U-nrntxa9hKCwJI_MduXej4oLPGwjS7xzkhxReQRWg-cDoFPeLIQ-EDwMn0Mq_oI_kPFlPoczlvvq1qdtWI6rPS8jm4jd5ALviOs3IH9OlnQQRobT7LFlC4CD0dKy1YHP9zYQGV4eviU5C6KcKZUwfjzptTDWBwH7pxkmS5NVTEtTlfm2SkLZyK-zYQ3BcwTcESOs1Jvuwgf5_O1w2bD9_s0jTcFayTfNEG8o3Ag7Bs2zjLpmsPjE3VMhRfQxh499yJHJVL-uh-NXRCdKVYVgiE666mi88M5wG-mODMZ49ONfDHNjubh3HY9Pvmj1Q-sBPUy4PLb83atzVuE2Xv55NSj5sPC6P-dR5xUbeenfjrMuiUvpuIia_0b_NMgHagcROaTjl7gKDIsvzHGsWg-qECuefTS2dr7z0n9UYoiS9_KxG-maC7T8JspPsjGDWj4VtR9nfaaSdt9KPcG5jrf-Hn8eYZ6_oY10iSZAeeXsK6OrgeZ_kyKv8T738jflQqKyEnP2OKkoEims87jDiXFAXGIFHm3zr-fda9TRHg4r2CHx-cJpykvxuFt0lVGi_r60dLh0S9diMUbj35Dl14hPVUI4wRvNr7PJrz23RzZ8sNDwPhoiOykzCqKbIKj8uvMSNAYxzt-luU4fD3hL-J3BGVXxmPe-XTJpAKBv0j3hGEvXXxnkmbBVdoGMNlhZ3ADgOVRpe1HOlTY3ce84JeU73nygeqNuM3EIluwG7hNZ2NKp_Nkkd483UIxzvikhCkIxgooBfDZZLEYp5yKMUzmN_K2exc7TzKaZsmIFpMkETM6ZWmaTYoSjROomFQj7_gjY7c34d3hbZqls2Rxo1gBqgnfOVOq4QsOTxGlaLK6sbfhtWPRbhs0TpRsXNOrcdIpuL1f3mGj-7dShw-OcTjEYkr-CcKTc3__4c6vMseklp5ko8TRy1iUrW9aq06_qn7Di9DOnt0t_b8AAAD__w98GOo">