<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/152983>152983</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
SemaDecl Assertion "Scope shouldn't contain decls!" failed
</td>
</tr>
<tr>
<th>Labels</th>
<td>
clang:frontend,
crash-on-invalid
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
gregbedwell
</td>
</tr>
</table>
<pre>
I happened to notice this while looking at an unrelated LLVM failure.
The following case compiles successfully:
```
// ================================================================
#include <utility>
struct c {
void d() noexcept(std::is_nothrow_swappable_v< int > &&
std::is_nothrow_swappable_v< int >);
};
// ----------------------------------------------------------------
```
However if I remove the include statement then as well as some genuine-looking errors, I also get an assertion failure:
https://godbolt.org/z/b7orMY3jM
```
// ================================================================
//#include <utility>
struct c {
void d() noexcept(std::is_nothrow_swappable_v< int > &&
std::is_nothrow_swappable_v< int >);
};
// ----------------------------------------------------------------
```
```
<source>:4:21: error: use of undeclared identifier 'std'
4 | void d() noexcept(std::is_nothrow_swappable_v< int > &&
| ^
<source>:4:54: error: expected '(' for function-style cast or type construction
4 | void d() noexcept(std::is_nothrow_swappable_v< int > &&
| ~~~ ^
<source>:5:24: error: expected ')'
5 | std::is_nothrow_swappable_v< int >);
| ^
<source>:4:20: note: to match this '('
4 | void d() noexcept(std::is_nothrow_swappable_v< int > &&
| ^
clang-22: /root/llvm-project/llvm/tools/clang/lib/Sema/SemaDecl.cpp:2241: void clang::Sema::ActOnPopScope(clang::SourceLocation, clang::Scope*): Assertion `(S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && "Scope shouldn't contain decls!"' 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-20250811/bin/clang-22 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -dumpdir /app/output.s- -disable-free -clear-ast-before-backend -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 -fcoverage-compilation-dir=/app -resource-dir /opt/compiler-explorer/clang-assertions-trunk-20250811/lib/clang/22 -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../include/c++/16.0.0 -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../include/c++/16.0.0/x86_64-linux-gnu -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../include/c++/16.0.0/backward -internal-isystem /opt/compiler-explorer/clang-assertions-trunk-20250811/lib/clang/22/include -internal-isystem /usr/local/include -internal-isystem /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -ferror-limit 19 -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/example-19df18.o -x c++ <source>
1. <source>:6:2: current parser token ';'
2. <source>:3:1: parsing struct/union/class body 'c'
#0 0x000000000400b248 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x400b248)
#1 0x00000000040080f4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#2 0x00007209a6842520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#3 0x00007209a68969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#4 0x00007209a6842476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#5 0x00007209a68287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#6 0x00007209a682871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#7 0x00007209a6839e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#8 0x0000000006a61cc9 clang::Sema::ActOnPopScope(clang::SourceLocation, clang::Scope*) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x6a61cc9)
#9 0x00000000066ad735 clang::Parser::ExitScope() (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66ad735)
#10 0x00000000066d50d8 clang::Parser::ParseLexedMethodDeclaration(clang::Parser::LateParsedMethodDeclaration&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66d50d8)
#11 0x00000000066ca8fd clang::Parser::ParseLexedMethodDeclarations(clang::Parser::ParsingClass&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66ca8fd)
#12 0x000000000671dff2 clang::Parser::ParseCXXMemberSpecification(clang::SourceLocation, clang::SourceLocation, clang::ParsedAttributes&, unsigned int, clang::Decl*) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x671dff2)
#13 0x0000000006720df0 clang::Parser::ParseClassSpecifier(clang::tok::TokenKind, clang::SourceLocation, clang::DeclSpec&, clang::Parser::ParsedTemplateInfo&, clang::AccessSpecifier, bool, clang::Parser::DeclSpecContext, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x6720df0)
#14 0x00000000066f413e clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*, clang::ImplicitTypenameContext) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66f413e)
#15 0x00000000066af698 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66af698)
#16 0x00000000066b00cf clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66b00cf)
#17 0x00000000066b78a3 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66b78a3)
#18 0x00000000066b87b5 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66b87b5)
#19 0x00000000066b8c70 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66b8c70)
#20 0x00000000066aa983 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x66aa983)
#21 0x00000000049b0c98 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x49b0c98)
#22 0x0000000004ca50a5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x4ca50a5)
#23 0x0000000004c213be clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x4c213be)
#24 0x0000000004d967f1 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0x4d967f1)
#25 0x0000000000daf0bf cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0xdaf0bf)
#26 0x0000000000da5d6a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#27 0x0000000000daa402 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0xdaa402)
#28 0x0000000000c5f604 main (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0xc5f604)
#29 0x00007209a6829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#30 0x00007209a6829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#31 0x0000000000da5815 _start (/opt/compiler-explorer/clang-assertions-trunk-20250811/bin/clang-22+0xda5815)
clang++: error: unable to execute command: Aborted (core dumped)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Compiler returned: 254
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzsWk1z4zbS_jX0BQUVCVIfPPigkazE9Xoqrngqb_akAoEmhRgEuABoy3vIb98CSJmSLGvHk2gqm1qVZkxSQOPppxvdDRDUWlEpgOto_CkaL69o6zbaXFcGqgL4M0h5VWj-cn2LNrRpQAFHTiOlnWCA3EZY9LwREpDU-lGoClGHqEKtMiCpA47u7n75jEoqZGtgFMXzKJ5_2QAqtZT62Xdg1AJium6EBItsyxhYW7ZSvkTpvOsQTeL-G88jsorICkXp8r_76zVJhWKy5YCidNE6IYV7idKbKJ5bZ1rmEEPR9FMUzxF60oIjHpFZRHKkNGwZNC4iM-u4ZymdC7tW2m2Mfl7bZ9o0tJCwforSBRLKoSi9QRGZ-K-X9vbz9XIikkepBxVNl_1FZxH8Bz_Hdo7nP-pneAKDRIlukYFaP3mPA7RjzTrqoAbl_FOFqEXeXf1fq2tAFahWKMA7zwRjtLERWaBbRKXVqILgq9RaME5otXPTV7_bONdYfxc0rDQvtHQjbaqIrP4VkVUx1ebzP9LfPv-93XQVvv9z1rPOenCbLqxuDQMPIZ1nUTonSZTOOxf0F60FpEvUKg5MUgMcCQ7KiVKAQRGZehXJtNc_Q9F0gS7Bq5cbjW9OQx5nB5Bh2wDzEd0D8ximqNQGla1ifvJg614k-GjukDbIvTQ-qqvOOYRW30WXD39-__330wSMvc3OEZAP9hmHsb_BK7_CCCT2QyvtfFTymbemjm26xPtqiO_oJ0xSVWFCPJqIrIzWLiIrKZ9q3Bj9G7DdbURWTmtpI7IKffxjUURk9QA17f8sgckRaxqvJ8nCDAnYuw4BamgdrubM_aTudfPAdAMRme03CqTdaUaDp5HFgYSu_TywPkfz12jv5yqZPeAovanArSStbM9ZRCbI_xR6BiEeabgNVOz98AXqxhc699TQuh8q72V0YkjXz250K7mKyNT5eeGoUMhPfhuRJCIkTCcqJHBfJN3f3cwfbpBti1o4RFHRVshAo43zLnCUloTbtMWI6Xpg_sgewtoWvCUQVfw1ffpUygy1G1RQ9ugMZeCpaww0RvsiDDjq3ZEsQk9qrWYilHWmVcgyIxrn8T44yh4Rb-umy53xKIrze6MrQ2tETdX6LG17n9HeGVd9xWcwbBupDZido-DXfGyxM616xCQm43iWJD7jCvXajhCEGUsQdkY0EtB2NllPMtyqR6WfFZZCtVtcqRZhqIXDuvgNYQ-RCx9iV7RpPJjWNa0bWYwwF9ZPBFwaAISZBGowtQ4XUGoD2JMEiiNcU6FwKSRgRWtAsKV1I8H7McK1Adm7Ia41B4kawRBuBMMSnkAi0t0IixsBCNeloTXgRgvlwETpkkqJcFlTt8FgjNIIl2WDvcMYylyULrVCuFQaG90qLlSFfdvu0ROYQlvA1NYI16_BVxtMpaAWLMJlq56F4th5TW2ULgnCjpoKHGZN6ynEkwxh1yoIDypQYLwGHIq2wkKVGj8KxaN0uScfYf5MTekBWD8B02XW96jAeGHCT8ZlxQuEy05SZ_6OKC685p1JEC6ZfgJDKzjTxkDnmLi35R9xqS4q7WKUd6pgC0UlFvbFOqjPj1Axhq2ijd10oTCIqxiLyKr3yFdPjMgqmYziURyR1Wj09r9-ZvqBIvIpfPsOf0lQJ4T9VXH6yftMDf8ovo-7z4Dk9Fit9XJ9kJD_qel3oe1E-7egYOsv2Fs9BtLPeMKJ3h8fIkSOxgDz6QfXlBkfG0NxhqXwaTLJES4r1bL9ODQiowTh0j6KBmtuMNsAe8RC4aoufazZbnFXH3nreoH7N0xLbTAXtFLaOsH8M8q5saJCeLle_7BYrH-c_3KzXv7__OcVWS9Wt-v5w-coXSYIa6-Cq32S6VMETnJeJrORRniLeidFBzVfPE985jyqAye-PvLJk7XG-OVuQ40Fg5x-BBWqwPRTVwWSE73TKJ2H0sr38uvgLmp7flWolrzzWosKzV-8MNYXlBFJYxRv490ni-OCZDMUSoxQ-9gX213cG6FcqAG-dFXEbGhk6PNaW2eA1qEkCjVmVyDN_tRiICKf4m0P0tdgnQrJkQqzuMzQg6gUlT9SxaUfahYQLZAVlU9waxeqxUWoRbvCse9h-2I1Dv-6AUg_wJTEOZ3MMjImca9bNy1PTDApCjayejTpMPsuA-L0UGA-yUuGGrcxQPn6UUj5Memh_yA9O4abTSeoskG9j8LOppNB8PhQMJlNyxTRwpesHxIbOg5iJ2_EJsWHBSbFIHB6KDDNIZ98TGDoMgic7XvYhE4SxvKLrWAuM2t61INO-YFOE8qn6Xgf0X0IQN31zVa4nUaXQ9hh6BD6aR0fIuTjmM_eQxiu72AL_DO4jebLsOfSMz17p9Ndt6izJztNLqhoUGVQNDlUlNFZyb9BUfu-pvddXlj4LHBZ1QL4QTVyoNo04WVJzqq2-PXXz1AXYB4aYKIU7IQNz8-kcz921p47Z0TROrB9umpVeEHCUZ8l9np4fi86LztOBsbSQ8ZIzMv4PGPeqD1bIdXtNXb6sd_D8HXE__lV3QfYCjsiDbCepXMg-G6T5FaV-m37eXjjswdygQqt5Rmpu7EXWjnYHlvlpB0vZqFgg8FC2eF0LbMkhbPk7M3RVwqOJutFqf52it8ESk_5nbC78mmv_W3dSMGE-_LSgKI1vEq9WKgJxA9mGR8ltHKSn08XXv-fzKrf3F5CedsvVE7E0bcx48MthKret_Ibq10uyXpeBtYmh6wVcczKr3XmA_KEEu9k2z-bu2PP-37cBXYG7qZH3E1nND3L3c22c7Dz1ckF-LocI17ngZHZESOzafFuURmuv-jmDp5Adml2n4qfGvrPFu6didLFUaD8wei2-RnK8J7lWP2hFv-seSvhtm608StXB5etfIKyAxX5MRVsej6Pr4Sx7m_FB5sOWZMcVfOU5rO3k2X-8OWo1Atvkib7BUP393Lx0QMbYB9uLuRFzA6zykJz-AHUvHsB2q-WgLUO-kcXXDH1cAawB9V2xug4pgfTb2V8Ulb8BNqL4uyQDDjTQ5wkSQs4JLUb-VZZRxWD07y-r9gF_bpHO-hyUA1mPJ9My2Rflx71oNKTPrWmeaPyBcN2j3LQ4aB0ijkt46JEjCXrmvree1t9c2PoSwg1C7ahpnv977H60LNAh88O99cuokqHddBkcqTJmE8o2plgkXwJsWNPn4eaSvkLMKeNL2BPqhWiz9DFy-iL21274G7ciCcwR9uHHtP0CBPN4n4NvON3t-zcUBPImn_diBdi1OMbGD1I6TEbl5M4Qx73ZYbvBhiGz482B3Oef3DvNXR5Ffi64f0qELIYrde-z9o6atx6T7mvHgKyvSGSYyecJWPUCb-UzfwQHYD-NVV4O3ZwHEnRQgJyGkE3HRDTdU0VDycmCm26Yy8zpg2E1_zAzwsMz1HZR96dtP6EA-JtGGvYdW4tIPwUngEgsRcG_SC78IcMuNYoCKjIODtxCCueX_HrlOdpTq_gOpmOszzOppPp1ea6TFgCJSN5mTLOytQH5JSkjNIyBZrHV-J6R2ScpySbjrJZzicFSaAk05SWPMpiqKmQIz_7RtpUV-FgxXUyJvksvZK0AGnDOVpCdtF7R0E44rHwPxhqN1grLNQTlSL8MF5emetwZqNoKxtlsRTW2WEYJ5yE692Jmf0jLF95uqQn_qo18vrbT4_0ej5dk38HAAD__4CLZP0">