[analyzer] Assertion `detail::isPresent(Val) && "dyn_cast on a non-existent value"' failed.

[k-arrows]

Reproducer:
https://godbolt.org/z/cvvon9q99

struct S {
  int a;
  operator bool () const { return true; }
};

using size_t = decltype (sizeof 0);

template <typename S>
size_t foo ()
{
  auto [...s] = S { 0 };
  if (s...[0]);
}

int bar ()
{
  if (foo <S> ());
}

Backtrace:

clang++: /root/llvm-project/llvm/include/llvm/Support/Casting.h:662: decltype(auto) llvm::dyn_cast(From*) [with To = clang::MemberExpr; From = clang::Expr]: Assertion `detail::isPresent(Val) && "dyn_cast on a non-existent value"' 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 --analyze <source>
1.	<eof> parser at end of file
2.	While analyzing stack: 
	#0 Calling foo() at line 17
	#1 Calling bar()
3.	<source>:12:7: Error evaluating statement
4.	<source>:12:7: Error evaluating statement
 #0 0x0000000004028478 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4028478)
 #1 0x00000000040258a4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40258a4)
 #2 0x0000000003f6a0d8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x000077a95ba42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000077a95ba969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x000077a95ba42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x000077a95ba287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x000077a95ba2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x000077a95ba39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x000000000659dd85 clang::ento::ExprEngine::VisitCommonDeclRefExpr(clang::Expr const*, clang::NamedDecl const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x659dd85)
#10 0x00000000065a3291 clang::ento::ExprEngine::Visit(clang::Stmt const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65a3291)
#11 0x00000000065a585d clang::ento::ExprEngine::ProcessStmt(clang::Stmt const*, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65a585d)
#12 0x000000000655a5ab clang::ento::CoreEngine::HandlePostStmt(clang::CFGBlock const*, unsigned int, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x655a5ab)
#13 0x000000000655ac98 clang::ento::CoreEngine::dispatchWorkItem(clang::ento::ExplodedNode*, clang::ProgramPoint, clang::ento::WorkListUnit const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x655ac98)
#14 0x000000000655b001 clang::ento::CoreEngine::ExecuteWorkList(clang::LocationContext const*, unsigned int, llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x655b001)
#15 0x000000000612d267 (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
#16 0x000000000612eea6 (anonymous namespace)::AnalysisConsumer::HandleDeclsCallGraph(unsigned int) AnalysisConsumer.cpp:0:0
#17 0x00000000061308b3 (anonymous namespace)::AnalysisConsumer::HandleTranslationUnit(clang::ASTContext&) AnalysisConsumer.cpp:0:0
#18 0x00000000066da71c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66da71c)
#19 0x0000000004cbedb5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cbedb5)
#20 0x0000000004c3af5e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c3af5e)
#21 0x0000000004db06d1 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4db06d1)
#22 0x0000000000db082f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdb082f)
#23 0x0000000000da74da ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#24 0x0000000004a321d9 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
#25 0x0000000003f6a574 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f6a574)
#26 0x0000000004a327ef 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
#27 0x00000000049f4a8d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49f4a8d)
#28 0x00000000049f5b1e 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+++0x49f5b1e)
#29 0x00000000049fd565 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49fd565)
#30 0x0000000000dacce5 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdacce5)
#31 0x0000000000c60ed4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc60ed4)
#32 0x000077a95ba29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#33 0x000077a95ba29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#34 0x0000000000da6f85 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda6f85)
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/cvvon9q99 ```cpp struct S { int a; operator bool () const { return true; } };

using size_t = decltype (sizeof 0);

template <typename S>
size_t foo ()
{
auto [...s] = S { 0 };
if (s...[0]);
}

int bar ()
{
if (foo <S> ());
}

Backtrace:
```console
clang++: /root/llvm-project/llvm/include/llvm/Support/Casting.h:662: decltype(auto) llvm::dyn_cast(From*) [with To = clang::MemberExpr; From = clang::Expr]: Assertion `detail::isPresent(Val) && "dyn_cast on a non-existent value"' 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 --analyze <source>
1.	<eof> parser at end of file
2.	While analyzing stack: 
	#<!-- -->0 Calling foo() at line 17
	#<!-- -->1 Calling bar()
3.	&lt;source&gt;:12:7: Error evaluating statement
4.	&lt;source&gt;:12:7: Error evaluating statement
 #<!-- -->0 0x0000000004028478 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4028478)
 #<!-- -->1 0x00000000040258a4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40258a4)
 #<!-- -->2 0x0000000003f6a0d8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x000077a95ba42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x000077a95ba969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #<!-- -->5 0x000077a95ba42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #<!-- -->6 0x000077a95ba287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #<!-- -->7 0x000077a95ba2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #<!-- -->8 0x000077a95ba39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #<!-- -->9 0x000000000659dd85 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+++0x659dd85)
#<!-- -->10 0x00000000065a3291 clang::ento::ExprEngine::Visit(clang::Stmt const*, clang::ento::ExplodedNode*, clang::ento::ExplodedNodeSet&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65a3291)
#<!-- -->11 0x00000000065a585d clang::ento::ExprEngine::ProcessStmt(clang::Stmt const*, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65a585d)
#<!-- -->12 0x000000000655a5ab clang::ento::CoreEngine::HandlePostStmt(clang::CFGBlock const*, unsigned int, clang::ento::ExplodedNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x655a5ab)
#<!-- -->13 0x000000000655ac98 clang::ento::CoreEngine::dispatchWorkItem(clang::ento::ExplodedNode*, clang::ProgramPoint, clang::ento::WorkListUnit const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x655ac98)
#<!-- -->14 0x000000000655b001 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+++0x655b001)
#<!-- -->15 0x000000000612d267 (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
#<!-- -->16 0x000000000612eea6 (anonymous namespace)::AnalysisConsumer::HandleDeclsCallGraph(unsigned int) AnalysisConsumer.cpp:0:0
#<!-- -->17 0x00000000061308b3 (anonymous namespace)::AnalysisConsumer::HandleTranslationUnit(clang::ASTContext&amp;) AnalysisConsumer.cpp:0:0
#<!-- -->18 0x00000000066da71c clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66da71c)
#<!-- -->19 0x0000000004cbedb5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cbedb5)
#<!-- -->20 0x0000000004c3af5e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c3af5e)
#<!-- -->21 0x0000000004db06d1 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4db06d1)
#<!-- -->22 0x0000000000db082f cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdb082f)
#<!-- -->23 0x0000000000da74da ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->24 0x0000000004a321d9 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
#<!-- -->25 0x0000000003f6a574 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f6a574)
#<!-- -->26 0x0000000004a327ef 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
#<!-- -->27 0x00000000049f4a8d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49f4a8d)
#<!-- -->28 0x00000000049f5b1e 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+++0x49f5b1e)
#<!-- -->29 0x00000000049fd565 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+++0x49fd565)
#<!-- -->30 0x0000000000dacce5 clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdacce5)
#<!-- -->31 0x0000000000c60ed4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc60ed4)
#<!-- -->32 0x000077a95ba29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->33 0x000077a95ba29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->34 0x0000000000da6f85 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda6f85)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[k-arrows]

Crash is trunk only:
https://godbolt.org/z/rqTGdhaxs

[AaronBallman]

CC @Xazax-hun @gribozavr @sgatev seems to be a recent regression

[vidur2]

Can I try taking this?

[steakhal]

Can I try taking this?

Go for it, like always. (We can not urge or discourage people of solving issues of course)

[vidur2]

i might be a bit slow if that's fine