<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63324>63324</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Crash at -O0 on x86_64-linux_gnu: Assertion `isa<T>(CanonicalType)' failed.
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          shao-hua-li
      </td>
    </tr>
</table>

<pre>
    Compiler explorer: https://godbolt.org/z/jWocx1h8E

Input program:
```C
int printf(const char *, ...);
char a, b, c, f;
int d = -1625723284, h = -1306316094;
signed char *e;
long g;
signed char **i = &e;
char j[] = {077};
long(k)() { return 0; }
int l(char *n) {
  for (;;)
 if (*n <= '9')
      ;
    else
      return 0;
}
static int o() {
  int m;
  c = a - 9;
  for (; c == 0;)
    for (; b;)
      if (k())
        return 0;
  for (; *e + d + (h - -1306316094) - -1625723339 <= 1;) {
    m = 0;
    for (; d + (h - -1306316094) - -1625723285 + m <= 1; m++)
      for (; g <= 1; g++)
 l(j);
    return 0;
  }
  return 7;
}
int main() {
  f = 202;
  *i = &f;
  o();
  printf("%d\n", (int)g);
}
```

```console
% clang-tk -O0 -fsanitize=undefined a.c
clang-17: /zdata/shaoli/compilers/ccbuilder-repos/llvm-project/clang/include/clang/AST/Type.h:7520: const T* clang::Type::castAs() const [with T = clang::FunctionProtoType]: Assertion `isa<T>(CanonicalType)' 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: /zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -main-file-name a.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/zdata/shaoli/realsmith/debug -resource-dir /zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/lib/clang/17 -internal-isystem /zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/11/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O0 -fdebug-compilation-dir=/zdata/shaoli/realsmith/debug -ferror-limit 19 -fsanitize=alignment,array-bounds,bool,builtin,enum,float-cast-overflow,function,integer-divide-by-zero,nonnull-attribute,null,pointer-overflow,return,returns-nonnull-attribute,shift-base,shift-exponent,signed-integer-overflow,unreachable,vla-bound,vptr -fsanitize-recover=alignment,array-bounds,bool,builtin,enum,float-cast-overflow,function,integer-divide-by-zero,nonnull-attribute,null,pointer-overflow,returns-nonnull-attribute,shift-base,shift-exponent,signed-integer-overflow,vla-bound,vptr -fno-sanitize-memory-param-retval -fno-sanitize-address-use-odr-indicator -fgnuc-version=4.2.1 -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/a-28d726.o -x c a.c
1.      a.c:9:1: current parser token 'int'
2.      a.c:8:6: LLVM IR generation of declaration 'k'
3.      a.c:8:6: Generating code for declaration 'k'
 #0 0x0000558777c0d27f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3b4627f)
 #1 0x0000558777c0a9d4 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f0ccd482420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #3 0x00007f0ccced300b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #4 0x00007f0ccceb2859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #5 0x00007f0ccceb2729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #6 0x00007f0cccec3fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #7 0x000055877aee1023 (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x6e1a023)
 #8 0x000055877af1e5e1 clang::ASTContext::getFunctionTypeWithExceptionSpec(clang::QualType, clang::FunctionProtoType::ExceptionSpecInfo const&) const (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x6e575e1)
 #9 0x000055877af1e530 clang::ASTContext::getFunctionTypeWithExceptionSpec(clang::QualType, clang::FunctionProtoType::ExceptionSpecInfo const&) const (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x6e57530)
#10 0x0000558777fa1961 clang::CodeGen::CodeGenFunction::getUBSanFunctionTypeHash(clang::QualType) const (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3eda961)
#11 0x0000558777fb28dc clang::CodeGen::CodeGenFunction::StartFunction(clang::GlobalDecl, clang::QualType, llvm::Function*, clang::CodeGen::CGFunctionInfo const&, clang::CodeGen::FunctionArgList const&, clang::SourceLocation, clang::SourceLocation) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3eeb8dc)
#12 0x0000558777fb64c7 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3eef4c7)
#13 0x000055877801a919 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3f53919)
#14 0x00005587780158c5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3f4e8c5)
#15 0x0000558778016498 clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x3f4f498)
#16 0x000055877801f2d3 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#17 0x0000558778e9f8a6 (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#18 0x0000558778e8fd00 clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x4dc8d00)
#19 0x000055877a019fa4 clang::ParseAST(clang::Sema&, bool, bool) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x5f52fa4)
#20 0x0000558778e9c578 clang::CodeGenAction::ExecuteAction() (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x4dd5578)
#21 0x00005587786ecd79 clang::FrontendAction::Execute() (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x4625d79)
#22 0x0000558778671c86 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x45aac86)
#23 0x00005587787cf326 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x4708326)
#24 0x00005587751280f4 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x10610f4)
#25 0x0000558775123e1a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#26 0x00005587751253ec clang_main(int, char**, llvm::ToolContext const&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x105e3ec)
#27 0x000055877503a165 main (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0xf73165)
#28 0x00007f0ccceb4083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#29 0x000055877511ebfe _start (/zdata/shaoli/compilers/ccbuilder-compilers/clang-assertion/bin/clang-17+0x1057bfe)
clang-tk: error: unable to execute command: Aborted
clang-tk: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 17.0.0 (https://github.com/llvm/llvm-project.git 53d405762219d798286b99c297098a14643440fe)
%
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkWl1v27jS_jXMDUFDor4vcuHYdbdAF2_fTU730qDIkcxGIgWSSpP99QeUZFtyk25bbIJzcBZdRxoOh_M8HA6Hkpi1slYA1yi5Qcn2ivXuoM21PTBNDj0jjbwqtXi63ui2kw0YDI9dow0YFK3xwbnOomiN6A7RXa1FqRu30qZGdPcXorsvf2r-GB7ydyjYomA9_n5QXe9wZ3RtWOs7j21pMP7bjPdSeR2pXIVozrWyDvMDMxjRNaIbvFqtEC1QdDNqD03MN5T-h_uf6tTqbQmMoi0mYUqTjEY0j73KYRJGQRqFaVDEpy4DKeI0JJwaGq1qXL-kh-haDjYRTWHp3ZeR4LE1uwmyDGXbhVlE83sPiuaIFl4HG3C9UThA0Q322ic0jSdlGlNN2mMrxpX24tybjm68vVEuq0FK1wqjaDP6mBWIZmeV4b-TS_4GGgvzxplD07QdvbKOOcmxd06fERz7enE7s8wHGhgmuJhJz56PCl4nWIDAC6Xysg1PKO9HDy7annF_Yc7PM0b0xscK9bf5AZNFdNBiEIwxFEXFkclwdGSOGOMWn_x_zvkfG4TmyaDXzofCLaI3w78FvpnxeqFeX6r78PkyXz8vkHOa3VNr9u3MD3PLpPp21quBARrQucnZCqlm8iloZpLT6keUIpoIlGzUcLnxKKVyiBb1vMvJo1Mumaedk9AnE91MYY1ognnDVE3cPSb_F2BSWaakk38Bira9ElBJv8DZik9reVAOM5_-fJYTzDFEdz5fNhLRHZ_ypPXXvOxlI8AQA532kqZ5aEln9Bfgzit4Y4jupOJNL2AmWd_eIbq7e-pgdUDROkto4EccE-EdouvRa58-o7VXG684s25tp5kYlVFy81W6A74bWJ_12vWKO6nVJ6OdHkwkWz_G2lowvgGjNJCWoWhzh6J3iOYbprSSnDWDtl9fGa6YbECsRnI-fXy3vn2HbV-20mGGy77GHrpx2OnL3UK6Q1-uuG4nXr6lR1rbg6cNMyXwRBJ2B8DcMHvAJeP3zjAOPiY6A53RHKwFga3uzSj2PZm1mkvmQGDTK2y5kZ2bXL51jN9j0bfdaSsKVigoPo37E2am7ltQzv7chC-kQ8iwI62I7kq_WnbHUMKE8xATZ2TXAH7M030ak17dK_1VkUaq_pHUqscEWumILr9g0hpo2CNhTYOJd11IgxnBREjLygZIZQAw4Q0wQ5h1pIRKGyCeL1ACE79cSSUbIIq14IN7tKk58x6SVgtocCc5Jp3kpIEHaDAdb6QlnQRM2sqwFkinpXK-GtgO3lQtcwcCxiiNSVV1hGvlp8ihaKsVJpXSxOheCalq4nUxaYc4NT132hDWSGbBYlL16qtUgjgPyKJoSzFxzNTgCO96zxJJY0xcr2AQ1KDAeIcFlH1dg_FN0sf6thYlJhXXD2BYDdPUjECF9J4_N60GWGNb6Q6I7gaTmBgYw8r3-sdCoZHlbNn7YBj4VKwh0j5ZB-2rDXVOPM8P2lvje2nOmh9UHQaoOUd0N4XxKXz9iCGiO1-3Xf48o_vtaPDoL_i3o56T56Wd7_f--SGmDWIIh18PowqM0YY00ufIsFjuOKyRtfL5BtENM4Y9kdKvFovoptS68X962TifPzag-hbRTdVo5ojP_MSHeNXor146ZXdENx6fXxBCPkgBpHwif4HRiG6UVqpvGsKcM7LsnU-YXoDoZlrWc4tjBXC6sOS57vYgK0dKZs838NhpNSIaq2VydGhmvFcGGD_4xY7o5qFhI25_3Tkz44gYGFbyfwNX_yxFz5CiNDnx0kKrzRPpmGEtMeAeWHOhwYQwYC3pLRAtDJFKSM6c9pZq1XPyAMZ6GqJtvKKrcEiajfZksFpp6yT3idmbsbLGZLvfv99s9r-tP7_bb_9c_7Gj-83uw359-zuKtiEm2i8g13aI7hihuchoutKYPGJ-LqdCv9f6u2hdoGgdDkVObwz44x8zFgx2-h6UP6wMJV829qPnfjmK1qnv9_Hj59_xhz_GrWBYmFhXWABv2HSLaHZ_MhE9Y-L91FXVmGsBQ0n9ogGMaBTg4DEIgiBJ8izLeCBoVuGhmhlqLPtkx4tPvpgdao27sWDJz0qGfd1r6wywFtHUFy1jcTue116j4kD0JniMyjilWXU-FSAahRdwWCFifCtrxZrfmBINmFPpPYntine-dAqG_0-G6GQoqwLORZzTmAZ4vzdgnTawN24CN24Zz2wAjSw7dzDAxMrqVTB4HMYxDRb-RvNhOIgoCEpsmLTwA_a5t5wOlmPfcWE5XlouaZ4UmJX6hzyfWaa-48Jycmk5O031D9vM6NJmurTJo0qkP2cz8l0WNrN5LDCAMKDRK4dkCiELaLRwI1-4UYWQQDg_xqxv7zZaOXh0430N7niy8ceUP6U7vHvk0HnBbQcc0XzW-__742lm8_2z0SBeGPqgKj2esYZVezpvvTJDSZZAuGCo-IahKPgfZyg6pwmf1ZZZumJhkS5iaKMFvAe1uDkCPHH2r5tbpubE_cbs4SWu3gZrBIIVabjAukzhVUlzwX8O661j5hQhS4DvG12yZgu8uQiHeZScd7azkfWF_tKL90fFi4h5ucuxw9rUH6V1L_W5HQ5sH6dz7d80vvqGC1Dmgi9mi17MVhrz7OdmaypZwDd-b7L-uVl5A56qmGcLnqI5T3kQsiIs_o6n37Xom2NeaqUb-TiC2kIlfWH8_RA_szbKP7Omh4G4V2ehSqIiLBYsxBcsJDlPfo2F_3z0MeQ8WaBPLtCncZH_GvqXMb8Briou8gWu9AJXRUX0s7judPcRHmBCMUc3So5TtuqYcb6cLvDC0rdVvPdsUQLmUFQ5G8pKprR6anVvsWIt2G440RQLB31O0uZD2zWjeDw-fN_N90b33R_gjyR4dOtm5Pl57_Kld3klgkXdczM-7txoZft2eGH5C368bjjEguciWBYry3IuCIuKxXNYn_yxeHg_MPf7Flo27X_Tw4_p72tDSKqEViyeQ6DBRdzwJHtupa5n29i7R-C9g_Wx6HgL7kWSZIulSBfFU54CF9lim9kZX0gr8Yznb-NzShORLTYFSpc-ZyHP0yXZ4yAflHVMcXie75dBvsWWHyeM8Txd4Fpu-RmvIrrANSE4w3s4VXL59-C_xfYVZ0Ee0SWexeadhDQPqhhzHu6nl6fnzXZtDHvy-SfaDC_5p9JrPbyF2-CljG7wg5biTWCFQRoG1XKtJxewIggZPs7NJrwbktAM3G3LmuYz8NPu8AzGdFl8eBvTCXZRhgojH17YHGh64VYSwXQMOvI9PMYa2Ry_3PixQV-b4QQiWJwR6GIXToKIhWkyvHF_ZV-qLArTRQlG84tnV3GQR3i_b2TJ99YfG_czv370aZY3shilWM5dCGUFeLT_-vRnZQUnb46fBqBojYfXNv6iV6xsADuNYQxzzHXbMiWGt-elNg7Ed7oPQlxNSfbYd3qRjkU_WLbDw1WPtreAycMgA8ByluXmPuLp2T0Os1WwCobvSn7qdfuqlg4nkYiDJEspDQuRFTnN07IoOC2yoMhZGKdxFMfBjB9Ek4uvK67EdSSKqGBXcB2meZrTuMijq8O1SNIYqpzFFc2DIk0YgyqnpchFxTJRpFfymgY0CtIwCQNaxNFKMF7ykLOyCLIqDSoUB9Ay2ay83ytt6qvhA4HrNIpofNWwEho7fMZGqYKveGhElKJke2WuB6xlX1sUB420zp6tOOkauN4MnxQwN7zk0wrP43bv4_ZXP4246k1z_evfPgzo_h0AAP__HmU4oQ">