[Clang] [C++20] Crash in special cases

[polarlinda6]

template<typename>
struct A {
  template<typename>
  friend void func(A);
};

template<typename, typename T>
struct B {
  template<typename>
  friend void func(A<int>) {
    T _{};
  }
};

auto main() -> int {
  B<int, int> _{};
  func<int>(A<int>{});
}

error message:

Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-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 -std=c++20 <source> -isystem/opt/compiler-explorer/libs/google-benchmark/trunk/include
1.	<eof> parser at end of file
2.	Per-file LLVM IR generation
3.	<source>:11:15: Generating code for declaration 'func'
 #0 0x00000000038b7b48 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x38b7b48)
 #1 0x00000000038b5cb4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x38b5cb4)
 #2 0x00000000037ffc48 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x000078a9b4c42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00000000072fc220 clang::ASTContext::getTypeInfoImpl(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72fc220)
 #5 0x00000000072e65ab clang::ASTContext::getTypeInfo(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72e65ab)
 #6 0x00000000072fbe2b clang::ASTContext::getPreferredTypeAlign(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72fbe2b)
 #7 0x000000000730517c clang::ASTContext::getDeclAlign(clang::Decl const*, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x730517c)
 #8 0x000000000400580d clang::CodeGen::CodeGenFunction::EmitAutoVarAlloca(clang::VarDecl const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x400580d)
 #9 0x000000000400c1c1 clang::CodeGen::CodeGenFunction::EmitVarDecl(clang::VarDecl const&) (.part.0) CGDecl.cpp:0:0
#10 0x000000000400c298 clang::CodeGen::CodeGenFunction::EmitDecl(clang::Decl const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x400c298)
#11 0x0000000003beb14f clang::CodeGen::CodeGenFunction::EmitDeclStmt(clang::DeclStmt const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3beb14f)
#12 0x0000000003bff53a clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bff53a)
#13 0x0000000003bf8392 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bf8392)
#14 0x0000000003bfefe9 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bfefe9)
#15 0x0000000003c6658a clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c6658a)
#16 0x0000000003c71828 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c71828)
#17 0x0000000003ccd69b clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ccd69b)
#18 0x0000000003cc8ee5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cc8ee5)
#19 0x0000000003cd4001 clang::CodeGen::CodeGenModule::EmitDeferred() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cd4001)
#20 0x0000000003cd5f93 clang::CodeGen::CodeGenModule::Release() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cd5f93)
#21 0x00000000041c8a9e (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&) ModuleBuilder.cpp:0:0
#22 0x00000000041c67f5 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41c67f5)
#23 0x00000000061a544c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x61a544c)
#24 0x00000000041c71e5 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41c71e5)
#25 0x0000000004472741 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4472741)
#26 0x00000000043f493b clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x43f493b)
#27 0x0000000004559193 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4559193)
#28 0x0000000000cc5dfc cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcc5dfc)
#29 0x0000000000cbfd3d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#30 0x0000000004210999 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
#31 0x0000000003800073 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3800073)
#32 0x0000000004210bb9 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
#33 0x00000000041d67f7 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41d67f7)
#34 0x00000000041d71ad clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41d71ad)
#35 0x00000000041e119c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41e119c)
#36 0x0000000000cc30e1 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcc30e1)
#37 0x0000000000b98984 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xb98984)
#38 0x000078a9b4c29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#39 0x000078a9b4c29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#40 0x0000000000cbf7de _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcbf7de)
clang++: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Compiler returned: 139

Additional Information:

Version: clang version 18.1.8
compilation parameters: -std=c++20
Link: godbolt

PS: The code compiles successfully on gcc and msvc.

[shafik]

Assertion: https://godbolt.org/z/79W1qTxzW

clang++: /root/build/tools/clang/include/clang/AST/TypeNodes.inc:79:
clang::TypeInfo clang::ASTContext::getTypeInfoImpl(const clang::Type*) const:
Assertion `!T->isDependentType() && "should not see dependent types here"' failed.

[llvmbot]

@llvm/issue-subscribers-clang-codegen

Author: PolarLinda6 (PolarLinda6)

```cpp template<typename> struct A { template<typename> friend void func(A); };

template<typename, typename T>
struct B {
template<typename>
friend void func(A<int>) {
T _{};
}
};

auto main() -> int {
B<int, int> _{};
func<int>(A<int>{});
}

#### error message:

```txt
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-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 -std=c++20 <source> -isystem/opt/compiler-explorer/libs/google-benchmark/trunk/include
1.	<eof> parser at end of file
2.	Per-file LLVM IR generation
3.	<source>:11:15: Generating code for declaration 'func'
 #<!-- -->0 0x00000000038b7b48 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x38b7b48)
 #<!-- -->1 0x00000000038b5cb4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x38b5cb4)
 #<!-- -->2 0x00000000037ffc48 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x000078a9b4c42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x00000000072fc220 clang::ASTContext::getTypeInfoImpl(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72fc220)
 #<!-- -->5 0x00000000072e65ab clang::ASTContext::getTypeInfo(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72e65ab)
 #<!-- -->6 0x00000000072fbe2b clang::ASTContext::getPreferredTypeAlign(clang::Type const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x72fbe2b)
 #<!-- -->7 0x000000000730517c clang::ASTContext::getDeclAlign(clang::Decl const*, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x730517c)
 #<!-- -->8 0x000000000400580d clang::CodeGen::CodeGenFunction::EmitAutoVarAlloca(clang::VarDecl const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x400580d)
 #<!-- -->9 0x000000000400c1c1 clang::CodeGen::CodeGenFunction::EmitVarDecl(clang::VarDecl const&amp;) (.part.0) CGDecl.cpp:0:0
#<!-- -->10 0x000000000400c298 clang::CodeGen::CodeGenFunction::EmitDecl(clang::Decl const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x400c298)
#<!-- -->11 0x0000000003beb14f clang::CodeGen::CodeGenFunction::EmitDeclStmt(clang::DeclStmt const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3beb14f)
#<!-- -->12 0x0000000003bff53a clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef&lt;clang::Attr const*&gt;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bff53a)
#<!-- -->13 0x0000000003bf8392 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef&lt;clang::Attr const*&gt;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bf8392)
#<!-- -->14 0x0000000003bfefe9 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&amp;, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bfefe9)
#<!-- -->15 0x0000000003c6658a clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c6658a)
#<!-- -->16 0x0000000003c71828 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c71828)
#<!-- -->17 0x0000000003ccd69b clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ccd69b)
#<!-- -->18 0x0000000003cc8ee5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cc8ee5)
#<!-- -->19 0x0000000003cd4001 clang::CodeGen::CodeGenModule::EmitDeferred() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cd4001)
#<!-- -->20 0x0000000003cd5f93 clang::CodeGen::CodeGenModule::Release() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cd5f93)
#<!-- -->21 0x00000000041c8a9e (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&amp;) ModuleBuilder.cpp:0:0
#<!-- -->22 0x00000000041c67f5 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41c67f5)
#<!-- -->23 0x00000000061a544c clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x61a544c)
#<!-- -->24 0x00000000041c71e5 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41c71e5)
#<!-- -->25 0x0000000004472741 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4472741)
#<!-- -->26 0x00000000043f493b clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x43f493b)
#<!-- -->27 0x0000000004559193 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4559193)
#<!-- -->28 0x0000000000cc5dfc cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcc5dfc)
#<!-- -->29 0x0000000000cbfd3d ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->30 0x0000000004210999 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
#<!-- -->31 0x0000000003800073 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3800073)
#<!-- -->32 0x0000000004210bb9 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
#<!-- -->33 0x00000000041d67f7 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x41d67f7)
#<!-- -->34 0x00000000041d71ad 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-trunk/bin/clang+++0x41d71ad)
#<!-- -->35 0x00000000041e119c 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-trunk/bin/clang+++0x41e119c)
#<!-- -->36 0x0000000000cc30e1 clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcc30e1)
#<!-- -->37 0x0000000000b98984 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xb98984)
#<!-- -->38 0x000078a9b4c29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->39 0x000078a9b4c29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->40 0x0000000000cbf7de _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xcbf7de)
clang++: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Compiler returned: 139

Additional Information:

Version: clang version 18.1.8
compilation parameters: -std=c++20
Link: godbolt

PS: The code compiles successfully on gcc and msvc.

[dfszabo]

Seems to work on trunk https://godbolt.org/z/zhhx8b8Tq

[shafik]

Looks like this was fixed in clang-20, although maybe we should add this reproducer as a test case. I am not sure where this was fixed though CC @cor3ntin @AaronBallman @efriedma-quic

[efriedma-quic]

Looks like #125266. Not sure this testcase is really any different from the ones we have.