<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/153928>153928</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang][bytecode] Assertion `(Base == RootPtrMark || Base % alignof(void *) == 0) && "wrong base"' failed.
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          k-arrows
      </td>
    </tr>
</table>

<pre>
    Reproducer:
https://godbolt.org/z/onbM4oqWf
```cpp
struct S { short t; };

void foo ()
{
  char a[32];
  ((struct S *) &a[2 * sizeof (short) - 1])->t = 0;
}
```

Backtrace:
```console
clang++: /root/llvm-project/llvm/tools/clang/lib/AST/ByteCode/Pointer.cpp:43: clang::interp::Pointer::Pointer(clang::interp::Block*, unsigned int, uint64_t): Assertion `(Base == RootPtrMark || Base % alignof(void *) == 0) && "wrong base"' 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 -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -fexperimental-new-constant-interpreter <source>
1.      <source>:7:1: current parser token '}'
2.      <source>:4:1: parsing function body 'foo'
3.      <source>:4:1: in compound statement ('{}')
 #0 0x00000000040213f8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40213f8)
 #1 0x000000000401e824 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x401e824)
 #2 0x0000000003f63058 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x000074a193042520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000074a1930969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x000074a193042476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x000074a1930287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x000074a19302871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x000074a193039e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x0000000007ba45e3 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7ba45e3)
#10 0x0000000007ba5347 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7ba5347)
#11 0x00000000079bc039 clang::interp::Pointer::atField(unsigned int) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x79bc039)
#12 0x0000000007b1af06 clang::interp::getField(clang::interp::InterpState&, clang::interp::CodePtr, clang::interp::Pointer const&, unsigned int) Interp.cpp:0:0
#13 0x0000000007b1b162 clang::interp::GetPtrFieldPop(clang::interp::InterpState&, clang::interp::CodePtr, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7b1b162)
#14 0x0000000007e387a1 clang::interp::Compiler<clang::interp::EvalEmitter>::VisitMemberExpr(clang::MemberExpr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e387a1)
#15 0x0000000007e32b10 clang::interp::Compiler<clang::interp::EvalEmitter>::visit(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e32b10)
#16 0x0000000007e036b4 clang::interp::Compiler<clang::interp::EvalEmitter>::visitAssignment(clang::Expr const*, clang::Expr const*, clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e036b4)
#17 0x0000000007e360f2 clang::interp::Compiler<clang::interp::EvalEmitter>::VisitBinaryOperator(clang::BinaryOperator const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e360f2)
#18 0x0000000007e32b10 clang::interp::Compiler<clang::interp::EvalEmitter>::visit(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e32b10)
#19 0x0000000007e27aba clang::interp::Compiler<clang::interp::EvalEmitter>::visitExpr(clang::Expr const*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7e27aba)
#20 0x00000000079bd381 clang::interp::EvalEmitter::interpretExpr(clang::Expr const*, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x79bd381)
#21 0x00000000079b09bf clang::interp::Context::evaluateAsRValue(clang::interp::State&, clang::Expr const*, clang::APValue&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x79b09bf)
#22 0x000000000792a3d3 EvaluateAsRValue((anonymous namespace)::EvalInfo&, clang::Expr const*, clang::APValue&) ExprConstant.cpp:0:0
#23 0x000000000792c461 clang::Expr::EvaluateForOverflow(clang::ASTContext const&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x792c461)
#24 0x0000000006927df6 clang::Sema::CheckForIntOverflow(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6927df6)
#25 0x000000000695f81c clang::Sema::CheckCompletedExpr(clang::Expr*, clang::SourceLocation, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x695f81c)
#26 0x0000000006cdf917 clang::Sema::ActOnFinishFullExpr(clang::Expr*, clang::SourceLocation, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6cdf917)
#27 0x0000000006feed5e clang::Sema::ActOnExprStmt(clang::ActionResult<clang::Expr*, true>, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6feed5e)
#28 0x00000000067ec2b4 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67ec2b4)
#29 0x00000000067e3984 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 24u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67e3984)
#30 0x00000000067e47c9 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 24u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67e47c9)
#31 0x00000000067ec92b clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67ec92b)
#32 0x00000000067ed13a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67ed13a)
#33 0x00000000066e334b clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e334b)
#34 0x000000000671971d clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x671971d)
#35 0x00000000066d676e clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66d676e)
#36 0x00000000066d6f0f clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66d6f0f)
#37 0x00000000066de783 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66de783)
#38 0x00000000066df695 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66df695)
#39 0x00000000066d179a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66d179a)
#40 0x00000000049c32f8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49c32f8)
#41 0x0000000004cb7355 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cb7355)
#42 0x0000000004c335ae clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c335ae)
#43 0x0000000004da8971 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4da8971)
#44 0x0000000000daff4f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdaff4f)
#45 0x0000000000da6baa ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#46 0x0000000004a2ad09 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
#47 0x0000000003f634f4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f634f4)
#48 0x0000000004a2b31f 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
#49 0x00000000049ed58d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49ed58d)
#50 0x00000000049ee61e 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+++0x49ee61e)
#51 0x00000000049f60b5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49f60b5)
#52 0x0000000000dac405 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdac405)
#53 0x0000000000c60394 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc60394)
#54 0x000074a193029d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#55 0x000074a193029e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#56 0x0000000000da6655 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda6655)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzkW1tv2zgW_jXMC6FAInV9yIPixLMdtGiQFLOPBiVRjjayqCGpXObXL0jKpilf2kyj7gJTpIAtkYff953DwyOaIkI0647SKxBdg-jmggzykfGrJ49wzl7ERcGqt6t72nNWDSXlAOfAzx-l7IX6iJYALdesKlgrLxlfA7T8C6Al64ovIfvz3zXwcxD75q_se-DnQvKhlPABguQaikfGJZQAX0OQ3AB8rdr7-TNrKlgzBgFKAcrUxUTdgrB8JBwSEF1jBKKxAzTNUmsZ5QBlEKBYtUTqOxTNX5TVqqUeU933YKBsoMwD-FZCgG-gP0JIbvaBG1DXpHySnJTUSGBpsU6wlgI_L1vSrQG6Vn84hwAtOWMSoGXbPm-8nrP_0HL7FaClZKwVAC3Hbsu2KQBa5g_fAFpev0m6YBUFaHnHmk5Sfqnkw3mIlWnTBecA5_pmbz6PTd0vKD3R-rpl5ZPWagGHTkdBBZtO6u9NJ-NwpXRS4-VCUC4b1kHFGaXXRFAlmNLsnjF5J_kXwp8gSBYgWUBzG0WQtM26YzVAqXbp1jGmoz86CaAYAoReOOvWsCCCAoQASmBNmpZWl8DP7z7f5g-3UAzFppGQwGJYQ057HTsMToKxkY9DcVmyjVV6on8jxECV8pB0inHZDhWF8pHCkhPxCIudp9EC9lzFfkmFoBUUbODmsupJhGBlQyStIB86KEre9FLhfZCkfILVsOlNrPiXwM_uOFtzsoGEr4cN7aQYY4T1ClPJNn3TUu7R175lXPnNBIZHttoLT_KhewJoWTSdjRsVbtBbVy-E114IvTX01MRZkr5X1gfZD_JSQG-jVICe95rGHhEbT7x1krwCfKNiooVe3THvmfKCCaruQ-8Bet66LD0Vp-UjaTrlt3N4VWPRkV48Mgm9umQt417VkHXHhGxKYcbQGk8u09ee8kapQlqvoy-emlSSdNIzAcuppBwCvBgdgG-BnwdKVecazhOA80DPkIFz2knYEy4oh5I90Q4ClKipjRLg5-hI73DbW_VqujWsh67UYa-yoOpeM2a643Pdmw4qfdjQVVBIIqliZrJUojKZwaATGwQI-9B_9bf_Qh8FuE6hDl09T8WbGGc0bzqpY-ubic7UNuLkZcWE5JRs9JRamJmcmVE_JMgAuvZfR3gWfOCCD2iKwmPgFy0l3dB_7R6adUdagNJdzmmZGmIGqBqMhYr2oeI6xn6UwoUKx3tasmfK3wy2f5GuanXmHDV02ixYJ-mrHPOxr_8b-3i0n4QkyLAfogj5IymT21_TeBWHXtt0w6u37gZzo7wU7DI2kFUXCzh0DWZxVpewl4-ckmr11LTt-6zr_tZ6NIUbJjFcCy3Be2GHSWwNx65hlCY1hqRQ6fpdZnVHazY5MBsU7zYYFNZg6hrEGc3i9xnUXazBbD_AkoKEEcUfHdWj2bEsQjjwJ4NGOExmGFSZtYM6sz7JitLH2Q9VJUQuG9pW-9N_nGQ65X84cAPNAkeuWgGp_fgU8DXdgT3R4pP-_KBS_Jh1TzRUtdyd5GdajCoZGUZjU4nMcJPMo1jhCasiiNGpgX6jqlzTxO5Y_7HcpoA_PAw1M-vN0OFNcZqQ4DRMMz7AixMtbp9Je7tppA7WW3Ptj0Y08gvdFJTfvvaTatpe37otn4O14WVZRxPWqAj8j2X9rFi7XH8BS8XDsoxdlj6Oi3AGlrl-_lUF2lm-TvS_494MOmklrE7JJBpivz45939iDlw3HeFvX3vKiWSTeeDemzlKFD_LPv1HzAW3sKAoIQWZgeVhhjuI9IKxdhbGmtOOMfInBUaF05OZ3eFjb3L644TmI2agW2LTysnPivq0K_WjhvlCn0k7EElzcf8HaQd6euU-sWafy1r53WgznkcDxdJq4BZhGSK4wvD2kB9AKelY97Zhg4Ad2VDR6-fezPr9U1ezn6GqWi7GzYbDwgrhCdIyjIPpQBaMgr9k_Osz5XXLXlwP5Q_fRn_u1Xizlb0aqVXcKZTiDCVV7ZS9D3RDxph7pOXTkvFPnTzOY-7kN6Kz2CMXe1SnQXkGu8p_LZW0Oj75DwPiQW_hfGYlUfBmzAUjdsvMKXHisqqzIDnOLC_l127ZdI14XA5t-7PUZk97IxlL1alS4prSKqJnqCo6D3IzWXdzvRl3T8XQSnd526Mv-aD342YkZ-Bbck4REie0RG6peqc3Ifc-G3rjxqDL8aBtpXTYrgQzkDFwLZlsQgZn6XkyOyJf-Q0tW8J1sOW1pDyXkjfFIKlwNisfNqRt_6ClKiQdNxqXazeicNBenKb27-hzNvyn08P03wd5dLRpizl8oFTe-cDdEY4TGiZl9jd88P8i-hyCKUmsYMF0BmaoOEtgMe7P74S7ZtUbQOlcKcNAsoDRBHAVYHIW8HL8KWIKeK-P8vyJIHdipWT9TJXeSMTSdOqnOKYYh-f9sqV5Q-uma8YgnnRouvU2yNWT6PeD9Rvd9C2RVBWLzgbbiV6fiaR25n9uZit1jCBWLrdMS4IsCaqz1JQOv3E29CdVeuhpecjW6nd8Ev9gZjyp8mH7H8rFo70l4_ekW9NPXTOX8kZbq7xbZMZVnMT0u8p_5XvhqvdLzS9bP7_EHLQ46828LKkQ6l5TN0qOGSJVK2L1iqd61X79Xb3GZcmR7eQs_3DVDh4Ef4lqtW8ffHEyUY0mKf5OoWiCyl3Uf4FSc2ih2Fot0okWdZxFZ7X4xvrP9Jm2ZpnbF-FrT_4c9G8QTmGzS473tD5a1tiHji-sGlr6adMzLu32yRwiKJpWhGwiQpBkh2WAPhKUTnEbNnM_xxlIO8Che1YhKzGq033AC1bR32hnntS2z2a0HCQdL-kTXR_-U78BYmG6pxLKIsGRE1xLrpa9rjqCcyaEBoNFiFyEGEeEukKaMT_pvSlz6uxQy9OUZonfEadl4dR3YUXSLJnsj2m8lszzrgBIz5GdJQWN-Cx6p9zyK1LXYQ3LMlhtSOM-POWckzedRhb6COJu_8tsNLjX0AI-s6aah4RBaTlEEw5xQQjcyr4Ivum8cPwx8NOmb48S0pnFdlE2jm1dVrx53h1M3Ns1DZ3iICSIVH6mJdkzuj1ateJa1fF8oJ7C298kStK2BSmfVnXnJnYz8Bg6i2DBNhvSVdNZfNR7Qo7tWK9GJ0qAPXEkb7r1uFwY1-46rFbl62sQmC8FEU25Err5KKHTWF1YSU4aKba3J-ZI26qpYB7Gx_uqyd6PEvluf9h0AShpyaaoiD49tpUKpdvzU7-z4ogzkumpp7DeP6B17GyTuXM_dA-kpu2bo-V5v318vI-IbcCnk-AqcOBUnv-44FCKX_aEy0v_dBRk7rpNqyitTqqmvUYOVsatlE7qnnRUDU49Yp9pmjvlzEy_ioy0d6EUTYoZSuOAvleU31khTivyOys-N0I6ipzLxbsI6EmjnD8ex_5REccw-SVSKrGslG7BldWxX0SnYN_sfXYKhCOVwSkX_EIpZ6hWtTxWPDRZw8vQH8XbViJb8DqV5GMi-P4K_eG1h0JmcTvVn1_GPs5CqBB_9MDGtB14cjAWZVX2zpO2uos1GE0N0tCHq5XqsxKScLnao_XDQ9Bwb4h4WqjFUQSN8Y_3kzJuht6_h3NIOVeryvgKCazHhwZYjvFvXrqAL418hPS1UeFUURjgUGEcBIXeM5QMCkphs1fMq5G2RTzkVA68o2r6qZ77L8tcVFe4ynBGLuhVkEQRRiFGwcXjVZQGUZZRvy7qBOMkpDEN0qxOEMZJUMTVRXOFfBT5aRD7sR-h4DLAPi5xlPkFTiqCKAh9uiFNe6mmxSXj6wv9nsdVEOEMpRctKWgr9FtOCG2TwJa-fuNkoW6oash-G5sVb5KW-m0cBKKbC36lXygphrUAod82Qgo7qGxkq1-mMp2jGxBd7_pHN__TV2kuBt5e_f3XZUYln6_QfwMAAP__9MmYqQ">