<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJy1WFtX4zYQ_jXJi05ybPn-kIcsJC2nuwdKaPvIkWU50a5jubIMob--I9mOLwlZoDTHYFnXb2Y-zYwUi-Rl8bDjJYKHIMmSirIEKVYqSkqGbpCIFeE51D1ztUO07jHBa_rEod1UEqSEQBk5IJ4rJmEsz7c5K0szD5rgUO2IQiLPXhDdMfoDZkuFRCXbpqTKVDnBEXre8YwhJV9gLMzXQIHBjoeDEM8n1vXEWk58q3nMp2L7IiMKujlXNCNlOXFWyBTQN6IkP7gH9-GlYMnE-VKPGFXjUK89rER783l2wSux35M8QRmoZOIsz_aB9UGEGaU2mrE9VzMRf0ezUgGI621eTfAXeOwAzQ6I1h9Hfc9pUZyd87ZSRaVeW3Ew3Fli-LPhDzEphdSFRCtTcZGjbcUTBt8AUhJTo00oKgWqJzzTypdMVTJHCnTxQZ15q9dxBQNg7FAwqmD8BAfaRjhAJAUOAQMKlLEnlh2xwoAPoUGj3xHdSUPLkbuvq-VmhcoqBusBu-NKK6UQUmli7pQqSm0JvIYH2sp5lj3t50Ju4RtpdvCcZhWoWe0Y7BhS7lBM6A9QsN45V6iAyaSgsEEAaikqWVfrkcBcQTnRGpFVjkoqeaEa7m8UTIKSal8ceWBBU3QnxVaSPSJyW-1ZrjQ40OdaQUe81tjgBRzUaHmut-5nENTWS8O2YyLVm64gsgSzwTZnIIZIUQrbudEz7GELWQcLfkHqezGxAhu7DjLQQBRnWb6UdeFOggsxgj7U2gq7TpI8P4pSSUZAIF9rDPpq449lbV88hv-bqtCWg9IfOVACKvg2J1k5ByPBpJ7vaVY6HVR7CNVPvdQ6B_W-yuupfgXDZUyWDRXfiKaFUW-NSG8LO-xQ4LHC_CRFg_VguU-Q37XMyt3CTm9hCs43tl0LPT5qry4ke5TGnx9nP4T-o-_OwG9Uh5nhjm4o1A6slMxLMbeAPdbBdmEWgNot4_aXsTyfxF6EDDFr7d7kXHGS8X-Mk9qwvyuWU9aQhEkIHyBi2BuwYXvS0OLcNCxZ5YorCEAiL9WFjma93ziQuN-zs_-3SpE4Y0spycs9S-vA086yOhRgFyitRtP_XpFMuybdeMZidc-jyYwo5qVhNRQJLV87ddyjqjdQIk7jMHDQWCemtKTqNgcCdOq4Brc61GBd8z58ekyDz8ZRqD280yOT32dxSlIW-7QP8M54jV75ugtMSx0Hro_Of5knSwVePa7AF50CbyLEiV1PVkgempzhJk_Fa2zoj1oLeQ8NTJviTeoxg9t3T0HWyNEEI-UkOAp-qpxfpKiKofi6DeK2bt1AND2VptPPlYAE7aBG7RsTgr4KavRuZPz_tYFt2zOvTiHhQCFxFCU0-alCbuW6yk1uc83SG51_gnc7VRDrsecvyHiMEOcNf1GXS6rjtm7jKddO-F3yyz4VrE7yaCx5QN68TwYKMBtc2_Cz5B9z4XPkB9u7xmU0CSNEXWukgpBG4UUVrA61rXuq-FSxP27YnlT2SKpAC3pJqgdRfNVp76l7vi0IBME7JYch5-gUTDBaNbLFQmQfFCHAfXZqIfDQUbHQd0735XLz8GpArtF8CBVM23LG05mK18EaZCo2Zl6YDBizltrbQdgwm6MN0IwCF15J1YY42vG9Yj3VMWezR4pyh4gCy7b9Xuqwak498GyZ0pasYZgg9FoW15wluoouoTPzzXfaiwb-iHjem6GIgpnY0FjnUg77NiyOweJ3WPxzWHqGgkN1AacFeQNqIMcsrzFVY70BtUaW1SR7hzHHy7X8shyrl19p4MEAuOO5vm_3gTcQuwmfjjE0vCTfW9xLC_jBWGX96lJtOK2Tw972aKNp_YMEHHYIgjPf457oU2DvYNXPZXdEtknRMY0d1EHFk-DJT2RQgBqytHUi-ZOOEut24Raua0jSgxuN4MKZ0UOt1Fd2rYYe6M2eZNmfjAJzbyChO4v9Ii9OINaFBqBjLip6OwpbY4B2kCIt0kdXCMPRCoNgEVmhn1gEjl7AB_oIzJHKaBDN9RKlPmrNu6LuNDOd5vpY51jhcBNiPIRvpW7ooXra5kR3-b7AnOPqYceD3IZt9YVDfY9krvJG11PTZOEkkRORKanUTsjFFqZKeLWfVjJbDG9SthCeq3hORf8IC69ZIcV3sLP2P2VZ6eR_ra8Enelu4QQWCUhsezZ1aBB7Ho6cMEoZCwMrdimeZiRmWbmYeF8mGOfsGZkpoDzxrqf_HQFfYAsSWaACBsK63txz0oDGth0n2E9935m4FoRBnh2viKZyYabU90bQmPFSdfdHU1KWcDpnzAAGhHBizdiidQXNXRIMe99BeWpQLwzkfwFU2bRw>52783</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Frontend crash @clang::InitializationSequence::Perform
        </td>
    </tr>

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

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

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

<pre>
    This is a reduced testcase I obtained with creduce/cvise with a too lax interestingness test (that only checked for segfaults) while trying to reduce #52782.
```
template <class> class Matrix4x4Typed;
Matrix4x4Typed() Matrix4x4Typed matrix
```
Command line:
```
clang -cc1 -emit-obj -std=gnu++17 -x c++ testcase.cpp
```
Output:
```
testcase.cpp:2:1: error: deduction guide declaration without trailing return type
Matrix4x4Typed() Matrix4x4Typed matrix
^
testcase.cpp:2:17: error: expected ';' after top level declarator
Matrix4x4Typed() Matrix4x4Typed matrix
                ^
                ;
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: /tmp/llvm/obj/bin/clang -cc1 -emit-obj -std=gnu++17 -x c++ testcase.cpp
1.      <eof> parser at end of file
 #0 0x00007f65ba071243 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /tmp/llvm/llvm/lib/Support/Unix/Signals.inc:565:13
 #1 0x00007f65ba06f5f0 llvm::sys::RunSignalHandlers() /tmp/llvm/llvm/lib/Support/Signals.cpp:97:18
 #2 0x00007f65ba0716df SignalHandler(int) /tmp/llvm/llvm/lib/Support/Unix/Signals.inc:407:1
 #3 0x00007f65c235b140 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14140)
 #4 0x00007f65c056ab59 clang::InitializationSequence::Perform(clang::Sema&, clang::InitializedEntity const&, clang::InitializationKind const&, llvm::MutableArrayRef<clang::Expr*>, clang::QualType*) /tmp/llvm/clang/lib/Sema/SemaInit.cpp:8061:23
 #5 0x00007f65c02fb873 clang::Sema::ActOnUninitializedDecl(clang::Decl*) /tmp/llvm/clang/lib/Sema/SemaDecl.cpp:12982:31
 #6 0x00007f65bfafeb6c clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::ForRangeInit*) /tmp/llvm/clang/lib/Parse/ParseDecl.cpp:0:13
 #7 0x00007f65bfafd297 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) /tmp/llvm/clang/lib/Parse/ParseDecl.cpp:2115:21
 #8 0x00007f65bfb99dcd clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) /tmp/llvm/clang/lib/Parse/Parser.cpp:0:10
 #9 0x00007f65bfb997ac clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) /tmp/llvm/clang/lib/Parse/Parser.cpp:1154:12
#10 0x00007f65bfb98c98 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) /tmp/llvm/clang/lib/Parse/Parser.cpp:0:12
#11 0x00007f65bfb97310 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, bool) /tmp/llvm/clang/lib/Parse/Parser.cpp:720:10
#12 0x00007f65bfae863d clang::ParseAST(clang::Sema&, bool, bool) /tmp/llvm/clang/lib/Parse/ParseAST.cpp:157:5
#13 0x00007f65c12e58d8 clang::FrontendAction::Execute() /tmp/llvm/clang/lib/Frontend/FrontendAction.cpp:971:10
#14 0x00007f65c1270116 llvm::Error::getPtr() const /tmp/llvm/llvm/include/llvm/Support/Error.h:276:12
#15 0x00007f65c1270116 llvm::Error::operator bool() /tmp/llvm/llvm/include/llvm/Support/Error.h:236:16
#16 0x00007f65c1270116 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /tmp/llvm/clang/lib/Frontend/CompilerInstance.cpp:1030:23
#17 0x00007f65c1354661 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /tmp/llvm/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:261:25
#18 0x00000000004142e5 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /tmp/llvm/clang/tools/driver/cc1_main.cpp:246:15
#19 0x0000000000412305 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) /tmp/llvm/clang/tools/driver/driver.cpp:317:12
#20 0x000000000041217f main /tmp/llvm/clang/tools/driver/driver.cpp:388:12
#21 0x00007f65b9086d0a __libc_start_main ./csu/../csu/libc-start.c:308:16
#22 0x000000000040f485 _start (/tmp/llvm/obj/bin/clang+0x40f485)
Segmentation fault
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy1WFtz6jYQ_jXwooGx5SsPPHASaDM9naSHtH3MyLIMOsdYriQnpL--K9nGF0hOkkkZEhvd9tvdT7srJSJ9Xt7vuULwJUiytKIsRZopTYli6AaJRBNeQNsT13tE6xETvKGPHPptI0FaCJSTI-KFZhLm8mJXMKXsOmiCY70nGokif0Z0z-gPWC0TEim2y0iVazXBC_S05zlDWj7DXFivgQKTvQBHMZ5PnOuJs5qETvO1PzU7lDnRMMy7ojlRauKtkX1BvxMt-dE_-vfPJUsn3pd6xqgZx0b2sBEd7M-LAq_E4UCKFOVgkom3ujgG5IMKM0pdNGMHrmci-Y5mSgOI611RTfAX-LoRmh0RrX-c7D2nZXlxzdtKl5V-SeJgurfC8OfCH2JSCmleUmNMzUWBdhVPGfwGkJLYFuNCUWkwPeG5Mb5kupIF0mCLD9osWL-MKxoAY8eSUQ3zJzgyPsIRIhlwCBhQopw9svyEFSZ8CA0afU7ozjpajtx9Xa-2a6SqBLwH7E4qY5RSSG2Iude6VMYTeANf6FPzPH88zIXcwW9k2MELmldgZr1nsGOI2qOE0B9gYLNzrlAJi0lBYYMAVCUqWTebmcBcQTkxFpFVgRSVvNQN97caFkFpdShPPHCga3EnxU6SAyJyVx1YoQ04sOdGw0C8MdjgARw0aHlhtu5nENQ1omHbMZGZTVcSqcBtsM0ZqCEylMF2buwMe9hBztGBT5SFQUKcyMW-hyw0UMVbqWdVv9xJCCFW0fvaWnE3SJKnB6G0ZAQUCo3FYKxx_ljX9sET-L-tSuM5ePuzAEpAA98VJFdzcBIsGoSBYaXXQXWHUMMsyJxLUL9VRb3Ur-C4nEnVUPGNaFoY9dZYmG3hxh0KPDZYmGZoIA_EfYL-vmMld4K9nmAKwTdxfQc9PJioLiR7kDaen1Y_xuFD6M8gblTHmeWO6Sj1HryUzpWYO8Ae5-j6sApA7cT4fTFOEJIkWCBLzNq6NwXXnOT8XxuktuyfihWUNSRhEtIHqBj3JmzZgTS0uLQMS9eF5hoSkCiUfmWglfcbBxL3R3b-_73SJMnZSkry_I1ldeJpV1kfS_ALvK1Hy_9RkdyEJtN5wWP1yJPLrCr2YWA1FImd0AR13KNqMDAizpI48tDYJvZtRfVtAQTozHENYXVowbrlffjMnAafixexifBej0xhn8UZyVgS0j7AOxs1eu_XXWJamTxwfQr-qyJdaYjqSQWx6Bx4kyHO_HomIb1vaoabIhMvsaE_ayPkN-hgxhVvMo-d3D57BnJGgSYaGSfFi-inxvlFiqocqm_6IG-b3i1k03NtOvtcCSjQjnrUv7Up6Kug1u5Wx__fGth1A_voDBIPDJIsFilNf2qQW7mpClvbXLPsxtSfEN3ODcR67PkbKh6rxGXHv2rLFTV52_TxjJsg_C79ZZ8KTqf5Yqx5RN68TwYGsBvc-PCz9B9z4XP0B9_7NmQ0BSNkXWdkgpgu4ldNsD7Wvu6Z4lPV_rhje1q5I60io-hrWt2L8qspe8_D821JIAneaTlMOaegYJPRutEtESL_oAoR7rPTKIGHgYrFoXe-L1fb-xcTco3mQ6hg2ZYzgalUgg7WoFJxMQvidMCYjTTRDtKG3RxtgmYUuPBCqTbE0c7vvdZLnWo2d2Qof4goclw37JUO6-bUA98d08aTNQybhF6q4pqzRNfQFXR2vfneRNEoHBEveDMUUTKbGxrvvFbDvg2LZ7GEHZbwEpaeo-BQXcJpQd6AGcipymtc1XhvQK2RZw3J3uHMsbiWX47n9OorAzwaAPcCPwzdPvAGYrfg4ymHxq_p95bw0gK-t17ZvCiqTad1cdjbHm02rT9QgMMOQXDmezgQcwrsHaz6teyeyLYoOpWxgzZoeBQ8_YkOGlBDlbZJJX80WWLTCm7h-pYkPbiLEVw4Mwao1frKrc3QA709kDz_i1Fg7g0UdBexv8qLM4j1SwPQsxcVvR2FnTFAN8qQUemjEuJ4JGGQLBZOHKYOgaMX8IE-AHOkthZEcyNCmaPWvHs1g2Z20Nwc6zwnHm5CjIfwncyPA1Qv25zoXr8vsOe4etrpILdlO3PhUN8j2au80fXUNF166cJbkCmcvXK2bEnd3IpMfOd9R75pJfPl8AJmB1m9SuZU9E--8JiVUnwHepiwpVRlzgwbc5PoTfdLwtJ0QcOQ-jgBM2PsUifGMQu8AMeJj6c5SViulpPgywTjgj0huwS8T4LrKV9iB6pX8D8GlvrBPPCyiCaum6Q4zMLQA7Ug9_H8dC80lUsLyVwWQWfOle4ujaZEKTiSM2bFwfqk0nshlzuwTMqrw9TKXlrs_wHSLJ7E">