Clang v15.0.2: crash

[RipleyTom]

Clang v15.0.2 seems to fail to compile rpcs3 ( https://github.com/RPCS3/rpcs3 ):

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: /usr/lib/llvm/15/bin/clang++ -DDATADIR=\"/usr/local/share/rpcs3\" -DGLX_GLXEXT_PROTOTYPES -DGL_GLEXT_PROTOTYPES -DHAVE_FAUDIO -DHAVE_LIBEVDEV -DHAVE_VULKAN -DHAVE_X11 -DLLVM_AVAILABLE -DSOUNDTOUCH_ALLOW_SSE -DSOUNDTOUCH_FLOAT_SAMPLES -DST_NO_EXCEPTION_HANDLING -DUSE_MULTICH_ALWAYS -DWC_NO_HARDEN -I/home/ripley/Repos/rpcs3/rpcs3 -I/home/ripley/Repos/rpcs3 -I/home/ripley/Repos/rpcs3/3rdparty/yaml-cpp/yaml-cpp/include -I/home/ripley/Repos/rpcs3/3rdparty/flatbuffers/include -I/home/ripley/Repos/rpcs3/3rdparty/pugixml/src -I/home/ripley/Repos/rpcs3/3rdparty/FAudio/src -I/home/ripley/Repos/rpcs3/3rdparty/FAudio/include -I/usr/include/AL -I/home/ripley/Repos/rpcs3/3rdparty/cubeb/cubeb/include -I/home/ripley/Repos/rpcs3_build/build_clang/exports -I/home/ripley/Repos/rpcs3/3rdparty/SoundTouch/soundtouch/include -I/home/ripley/Repos/rpcs3/3rdparty/stblib/include -I/home/ripley/Repos/rpcs3_build/build_clang/3rdparty/libpng/libpng -I/home/ripley/Repos/rpcs3/3rdparty/libpng/libpng -I/home/ripley/Repos/rpcs3/llvm/include -I/home/ripley/Repos/rpcs3_build/build_clang/3rdparty/llvm_build/include -I/home/ripley/Repos/rpcs3/3rdparty/asmjit/asmjit/src -I/home/ripley/Repos/rpcs3/3rdparty/ffmpeg/include -I/home/ripley/Repos/rpcs3/3rdparty/GL -I/home/ripley/Repos/rpcs3/3rdparty/glslang/glslang/SPIRV/.. -I/home/ripley/Repos/rpcs3_build/build_clang/include -I/home/ripley/Repos/rpcs3/3rdparty/SPIRV/SPIRV-Tools/include -I/home/ripley/Repos/rpcs3/3rdparty/SPIRV/SPIRV-Headers/include -I/home/ripley/Repos/rpcs3/3rdparty/libusb/libusb/libusb -I/home/ripley/Repos/rpcs3/3rdparty/wolfssl/wolfssl -I/home/ripley/Repos/rpcs3_build/build_clang/3rdparty/wolfssl/wolfssl -I/home/ripley/Repos/rpcs3/3rdparty/xxHash/cmake_unofficial/.. -I/home/ripley/Repos/rpcs3/3rdparty/xxHash -isystem /usr/include/libevdev-1.0 -isystem /usr/include/SDL2 -Wl,--exclude-libs,ALL -O3 -DNDEBUG -pthread -Wall -fno-exceptions -fstack-protector -msse -msse2 -mcx16 -Werror=old-style-cast -Werror=sign-compare -Werror=reorder -Werror=return-type -Werror=overloaded-virtual -Werror=missing-noreturn -Wunused-parameter -Wignored-qualifiers -Wredundant-move -Wcast-qual -Wdeprecated-copy -Wtautological-compare -Wempty-body -Wredundant-decls -Wstrict-aliasing=1 -Werror=inconsistent-missing-override -fconstexpr-steps=16777216 -Wno-unused-lambda-capture -Wno-unused-private-field -Wno-delete-non-virtual-dtor -Wno-unused-command-line-argument -march=native -std=gnu++20 -MD -MT rpcs3/Emu/CMakeFiles/rpcs3_emu.dir/cache_utils.cpp.o -MF CMakeFiles/rpcs3_emu.dir/cache_utils.cpp.o.d -o CMakeFiles/rpcs3_emu.dir/cache_utils.cpp.o -c /home/ripley/Repos/rpcs3/rpcs3/Emu/cache_utils.cpp
1.      <eof> parser at end of file
 #0 0x00007fdf5f2a98a1 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/llvm/15/bin/../lib64/libLLVM-15.so+0xef38a1)
 #1 0x00007fdf5f2a72f4 llvm::sys::RunSignalHandlers() (/usr/lib/llvm/15/bin/../lib64/libLLVM-15.so+0xef12f4)
 #2 0x00007fdf5f1b7bb8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007fdf5dfaec10 __restore_rt libc_sigaction.c:0:0
 #4 0x00007fdf5e00a8c5 cfree@GLIBC_2.2.5 (/lib64/libc.so.6+0x938c5)
 #5 0x00007fdf66d45693 clang::Sema::PopExpressionEvaluationContext() (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x1643693)
 #6 0x00007fdf662aa7e6 clang::ParseAST(clang::Sema&, bool, bool) (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0xba87e6)
 #7 0x00007fdf67dead19 clang::FrontendAction::Execute() (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x26e8d19)
 #8 0x00007fdf67d83e62 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x2681e62)
 #9 0x00007fdf67e5e517 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x275c517)
#10 0x000055e6b2f6e05c cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/lib/llvm/15/bin/clang+++0x1805c)
#11 0x000055e6b2f69661 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#12 0x00007fdf67a55ed5 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#13 0x00007fdf5f1b7cc3 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/usr/lib/llvm/15/bin/../lib64/libLLVM-15.so+0xe01cc3)
#14 0x00007fdf67a57974 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x2355974)
#15 0x00007fdf67a22463 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x2320463)
#16 0x00007fdf67a22bfd clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x2320bfd)
#17 0x00007fdf67a3211c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/usr/lib/llvm/15/bin/../lib64/libclang-cpp.so.15+0x233011c)
#18 0x000055e6b2f6b84c clang_main(int, char**) (/usr/lib/llvm/15/bin/clang+++0x1584c)
#19 0x00007fdf5df9a34a __libc_start_call_main libc-start.c:0:0
#20 0x00007fdf5df9a3fc __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x233fc)
#21 0x000055e6b2f66a41 _start (/usr/lib/llvm/15/bin/clang+++0x10a41)
clang-15: error: clang frontend command failed with exit code 139 (use -v to see invocation)
clang version 15.0.2
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/15/bin
Configuration file: /etc/clang/clang++.cfg
clang-15: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-15: note: diagnostic msg: /tmp/cache_utils-93deb0.cpp
clang-15: note: diagnostic msg: /tmp/cache_utils-93deb0.sh
clang-15: note: diagnostic msg: 

********************
make[2]: *** [rpcs3/Emu/CMakeFiles/rpcs3_emu.dir/build.make:76: rpcs3/Emu/CMakeFiles/rpcs3_emu.dir/cache_utils.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:29773: rpcs3/Emu/CMakeFiles/rpcs3_emu.dir/all] Error 2
make: *** [Makefile:156: all] Error 2

I wish I could give you a small sample but all I can give you are those 5MB preprocessed sources:

cache_utils-93deb0..zip

Clang15 seems to compile all the submodules(including llvm14 itself) just fine but fails on rpcs3 itself.
Of note is that Rpcs3 uses C++20 extensively.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[royjacobson]

Reduced to

struct channel {
    consteval channel(const char* name) noexcept { }
};
consteval const char* make_channel_name(const char* name) { return name;}

channel rsx_log(make_channel_name("rsx_log"));
channel sys_log(make_channel_name("sys_log"));

https://godbolt.org/z/n19hcEPYv

[shafik]

Assertion:

clang++: /root/llvm-project/clang/lib/Sema/SemaExpr.cpp:17866: 
void RemoveNestedImmediateInvocation(clang::Sema&, clang::Sema::ExpressionEvaluationContextRecord&, llvm::SmallVectorTemplateCommon<llvm::PointerIntPair<clang::ConstantExpr*, 1>, void>::reverse_iterator)::ComplexRemove::RemoveImmediateInvocation(clang::ConstantExpr*):
Assertion `It != IISet.rend() && "ConstantExpr marked IsImmediateInvocation should " "be present"' failed.

Backtrace:

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 -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++2b <source>
1.	<eof> parser at end of file
 #0 0x000056318d1625cf llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40d25cf)
 #1 0x000056318d16056c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40d056c)
 #2 0x000056318d0ad248 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f3a77ef8420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f3a779c500b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007f3a779a4859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007f3a779a4729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007f3a779b5fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x000056318fcb4255 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6c24255)
 #9 0x000056318fdd34f2 RemoveNestedImmediateInvocation(clang::Sema&, clang::Sema::ExpressionEvaluationContextRecord&, std::reverse_iterator<llvm::PointerIntPair<clang::ConstantExpr*, 1u, unsigned int, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>, llvm::PointerIntPairInfo<clang::ConstantExpr*, 1u, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>>>*>)::ComplexRemove::TransformInitializer(clang::Expr*, bool) SemaExpr.cpp:0:0
#10 0x000056318fdd375e clang::TreeTransform<RemoveNestedImmediateInvocation(clang::Sema&, clang::Sema::ExpressionEvaluationContextRecord&, std::reverse_iterator<llvm::PointerIntPair<clang::ConstantExpr*, 1u, unsigned int, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>, llvm::PointerIntPairInfo<clang::ConstantExpr*, 1u, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>>>*>)::ComplexRemove>::TransformExprs(clang::Expr* const*, unsigned int, bool, llvm::SmallVectorImpl<clang::Expr*>&, bool*) SemaExpr.cpp:0:0
#11 0x000056318fdd4a9e clang::TreeTransform<RemoveNestedImmediateInvocation(clang::Sema&, clang::Sema::ExpressionEvaluationContextRecord&, std::reverse_iterator<llvm::PointerIntPair<clang::ConstantExpr*, 1u, unsigned int, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>, llvm::PointerIntPairInfo<clang::ConstantExpr*, 1u, llvm::PointerLikeTypeTraits<clang::ConstantExpr*>>>*>)::ComplexRemove>::TransformCXXConstructExpr(clang::CXXConstructExpr*) SemaExpr.cpp:0:0
#12 0x000056318fd45f28 clang::Sema::PopExpressionEvaluationContext() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6cb5f28)
#13 0x000056318f7f2a06 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6762a06)
#14 0x000056318e4e66c8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x54566c8)
#15 0x000056318dd50db9 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4cc0db9)
#16 0x000056318dcd656e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c4656e)
#17 0x000056318de38443 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4da8443)
#18 0x000056318a5e05cd cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x15505cd)
#19 0x000056318a5dc6e7 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#20 0x000056318db3c4d9 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
#21 0x000056318d0ad730 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x401d730)
#22 0x000056318db3cd8f 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
#23 0x000056318db052ec clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4a752ec)
#24 0x000056318db05d6d 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+++0x4a75d6d)
#25 0x000056318db0ef3c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4a7ef3c)
#26 0x000056318a5ded32 clang_main(int, char**) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x154ed32)
#27 0x00007f3a779a6083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#28 0x000056318a5d73ce _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x15473ce)
clang-17: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[DimitryAndric]

This starts appearing after 1c55f05 ("Properly diagnose constant evaluation issues at TU scope") by @AaronBallman.

It looks like this change is pretty minimal, but add a line EnterExpressionEvaluationContext PotentiallyEvaluated(S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated); at a pretty early stage in parsing, so maybe this uncovered a problem in the expression evaluator...

[Fznamznon]

struct channel {
    consteval channel(const char* name) noexcept { }
};
consteval const char* make_channel_name(const char* name) { return name;}

channel rsx_log(make_channel_name("rsx_log"));
channel sys_log(make_channel_name("sys_log"));

I've been looking into this. Looks like when immediate invocations are handled, it it expected that if there was several immediate invocations they all belong to the same expression evaluation context, so the function call below:

llvm-project/clang/lib/Sema/SemaExpr.cpp

Line 17982 in 117db47

RemoveNestedImmediateInvocation(SemaRef, Rec, It);

tries to remove subexpressions and fails to find one. It starts with a call to constructor of channel class, then tries to remove its subexpression which is call to make_channel_name.

The thing is, during parsing of non local variable initializer a new evaluation context is pushed:

llvm-project/clang/lib/Sema/SemaDeclCXX.cpp

Line 17852 in 117db47

ExpressionEvaluationContext::PotentiallyEvaluated, D);

so the call to make_channel_name ends up being attached to another expression evaluation context. Immediate invocations are handled per evaluation context, so we get an assertion since we can't find call make_channel_name in the same context as the constructor call and get an assertion.