[analyzer] crashes on structured bindings with _Complex type

[k-arrows]

Reproducer:
https://godbolt.org/z/s1MTG4z45

using E = _Complex int;

template<typename T> T &make();

auto [e1, e2] = make<E>();

int test_globals() {
  return e2;
}

Backtrace:

An unknown case of structured binding encountered!
UNREACHABLE executed at /root/llvm-project/llvm/tools/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp:3314!
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 --analyze <source>
1.	<eof> parser at end of file
2.	While analyzing stack: 
	#0 Calling test_globals()
3.	<source>:8:10: Error evaluating statement
4.	<source>:8:10: Error evaluating statement
 #0 0x0000000003fdb0d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fdb0d8)
 #1 0x0000000003fd8504 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fd8504)
 #2 0x0000000003f1ccf8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007593c0c42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007593c0c969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x00007593c0c42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x00007593c0c287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000000003f284ba (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f284ba)
 #8 0x0000000006543fc6 clang::ento::ExprEngine::VisitCommonDeclRefExpr(clang::Expr const*, clang::NamedDecl const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6543fc6)
 #9 0x00000000065494f1 clang::ento::ExprEngine::Visit(clang::Stmt const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65494f1)
#10 0x000000000654babd clang::ento::ExprEngine::ProcessStmt(clang::Stmt const*, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x654babd)
#11 0x00000000065009fa clang::ento::CoreEngine::HandleBlockEntrance(clang::BlockEntrance const&, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65009fa)
#12 0x0000000006500f72 clang::ento::CoreEngine::dispatchWorkItem(clang::ento::ExplodedNode*, clang::ProgramPoint, clang::ento::WorkListUnit const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6500f72)
#13 0x0000000006501301 clang::ento::CoreEngine::ExecuteWorkList(clang::LocationContext const*, unsigned int, llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6501301)
#14 0x00000000060c83f7 (anonymous namespace)::AnalysisConsumer::HandleCode(clang::Decl*, unsigned int, clang::ento::ExprEngine::InliningModes, llvm::DenseSet<clang::Decl const*, llvm::DenseMapInfo<clang::Decl const*, void>>*) AnalysisConsumer.cpp:0:0
#15 0x00000000060ca02e (anonymous namespace)::AnalysisConsumer::HandleDeclsCallGraph(unsigned int) AnalysisConsumer.cpp:0:0
#16 0x00000000060cba33 (anonymous namespace)::AnalysisConsumer::HandleTranslationUnit(clang::ASTContext&) AnalysisConsumer.cpp:0:0
#17 0x00000000066861fc clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66861fc)
#18 0x0000000004c7aa05 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c7aa05)
#19 0x0000000004bf780e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bf780e)
#20 0x0000000004d6e731 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4d6e731)
#21 0x0000000000daa41f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdaa41f)
#22 0x0000000000da106a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#23 0x00000000049eeaa9 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 0x0000000003f1d194 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f1d194)
#25 0x00000000049ef0bf 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 0x00000000049b16ed clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49b16ed)
#27 0x00000000049b277e 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+++0x49b277e)
#28 0x00000000049ba7b5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49ba7b5)
#29 0x0000000000da68cf clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda68cf)
#30 0x0000000000c5b7d4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc5b7d4)
#31 0x00007593c0c29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#32 0x00007593c0c29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#33 0x0000000000da0b15 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda0b15)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-clang-static-analyzer

Author: None (k-arrows)

Reproducer: https://godbolt.org/z/s1MTG4z45 ```cpp using E = _Complex int;

template<typename T> T &make();

auto [e1, e2] = make<E>();

int test_globals() {
return e2;
}

Backtrace:
```console
An unknown case of structured binding encountered!
UNREACHABLE executed at /root/llvm-project/llvm/tools/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp:3314!
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 --analyze <source>
1.	<eof> parser at end of file
2.	While analyzing stack: 
	#<!-- -->0 Calling test_globals()
3.	&lt;source&gt;:8:10: Error evaluating statement
4.	&lt;source&gt;:8:10: Error evaluating statement
 #<!-- -->0 0x0000000003fdb0d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fdb0d8)
 #<!-- -->1 0x0000000003fd8504 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fd8504)
 #<!-- -->2 0x0000000003f1ccf8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x00007593c0c42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x00007593c0c969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #<!-- -->5 0x00007593c0c42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #<!-- -->6 0x00007593c0c287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #<!-- -->7 0x0000000003f284ba (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f284ba)
 #<!-- -->8 0x0000000006543fc6 clang::ento::ExprEngine::VisitCommonDeclRefExpr(clang::Expr const*, clang::NamedDecl const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6543fc6)
 #<!-- -->9 0x00000000065494f1 clang::ento::ExprEngine::Visit(clang::Stmt const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65494f1)
#<!-- -->10 0x000000000654babd clang::ento::ExprEngine::ProcessStmt(clang::Stmt const*, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x654babd)
#<!-- -->11 0x00000000065009fa clang::ento::CoreEngine::HandleBlockEntrance(clang::BlockEntrance const&amp;, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65009fa)
#<!-- -->12 0x0000000006500f72 clang::ento::CoreEngine::dispatchWorkItem(clang::ento::ExplodedNode*, clang::ProgramPoint, clang::ento::WorkListUnit const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6500f72)
#<!-- -->13 0x0000000006501301 clang::ento::CoreEngine::ExecuteWorkList(clang::LocationContext const*, unsigned int, llvm::IntrusiveRefCntPtr&lt;clang::ento::ProgramState const&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6501301)
#<!-- -->14 0x00000000060c83f7 (anonymous namespace)::AnalysisConsumer::HandleCode(clang::Decl*, unsigned int, clang::ento::ExprEngine::InliningModes, llvm::DenseSet&lt;clang::Decl const*, llvm::DenseMapInfo&lt;clang::Decl const*, void&gt;&gt;*) AnalysisConsumer.cpp:0:0
#<!-- -->15 0x00000000060ca02e (anonymous namespace)::AnalysisConsumer::HandleDeclsCallGraph(unsigned int) AnalysisConsumer.cpp:0:0
#<!-- -->16 0x00000000060cba33 (anonymous namespace)::AnalysisConsumer::HandleTranslationUnit(clang::ASTContext&amp;) AnalysisConsumer.cpp:0:0
#<!-- -->17 0x00000000066861fc clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66861fc)
#<!-- -->18 0x0000000004c7aa05 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c7aa05)
#<!-- -->19 0x0000000004bf780e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bf780e)
#<!-- -->20 0x0000000004d6e731 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4d6e731)
#<!-- -->21 0x0000000000daa41f cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdaa41f)
#<!-- -->22 0x0000000000da106a ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->23 0x00000000049eeaa9 void llvm::function_ref&lt;void ()&gt;::callback_fn&lt;clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const::'lambda'()&gt;(long) Job.cpp:0:0
#<!-- -->24 0x0000000003f1d194 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f1d194)
#<!-- -->25 0x00000000049ef0bf clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const (.part.0) Job.cpp:0:0
#<!-- -->26 0x00000000049b16ed clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49b16ed)
#<!-- -->27 0x00000000049b277e clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49b277e)
#<!-- -->28 0x00000000049ba7b5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49ba7b5)
#<!-- -->29 0x0000000000da68cf clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda68cf)
#<!-- -->30 0x0000000000c5b7d4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc5b7d4)
#<!-- -->31 0x00007593c0c29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->32 0x00007593c0c29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->33 0x0000000000da0b15 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda0b15)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[k-arrows]

Goes back to clang-15.0.0:
https://godbolt.org/z/nocPfP5dv

[NagyDonat]

I looked at the code that triggers llvm_unreachable, but I'm not familiar enough with this area (internal representations of structured bindings and their subtypes) to provide a fix in the foreseeable future. @isuckatcs In the git blame I see that you were the one who implemented support for (other kinds of) structured bindings in the analyzer; do you have time to cover this _Complex case as well?