Workarounds for Saigo Clang 21

[illwieckz]

Workarounds for latest Saigo

I need that when I build with the current Saigo (based on Clang 21).

[slipher]

PIC is not useful with NaCl under any circumstances. Why not have the condition be simply NOT NACL?

[illwieckz]

We can do that.

[illwieckz]

Now done.

[illwieckz]

I also imported the commit entirely removing GAME_PIE from:

• cmake: make DaemonPlatform, Architecture, Compiler, etc. autonomous and reusable #1641

[illwieckz]

Actually that GAME_PIE thing was a previous attempt to workaround the same limitations, except it's better to just disable PIE completely for NaCl.

For information, here is the Clang crash that happens with Google-built Saigo when building an amd64 cgame:

Unknown TLS model
UNREACHABLE executed at /b/s/w/ir/x/w/native_client/toolchain_build/src/llvm-saigo/llvm/lib/Target/X86/X86ISelLowering.cpp:19173!
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: saigo_newlibsaigo_newlib/bin/x86_64-nacl-clang++ -DDAEMON_ARCH_nacl -DDAEMON_BUILD_RelWithDebInfo -DDAEMON_CXX_COMPILER_Saigo=1 -DDAEMON_C_COMPILER_Saigo=1 -DDAEMON_USE_ARCH_INTRINSICS=1 -DDAEMON_USE_ARCH_INTRINSICS_nacl=1 -DDAEMON_USE_COMPILER_CUSTOMIZATION=1 -DDAEMON_USE_COMPILER_INTRINSICS=1 -DGLM_FORCE_EXPLICIT_CTOR -DLUA_COMPAT_APIINTCASTS -DNACL_BUILD_ARCH=x86 -DNACL_BUILD_SUBARCH=64 -DRC_MAX_LAYERS_DEF=63 -DRC_MAX_NEIS_DEF=16 -DRMLUI_STATIC_LIB @CMakeFiles/srclibs-rmlui.dir/includes_CXX.rsp -std=gnu++14 -fvisibility=hidden -fno-strict-aliasing -pthread -fPIC -fno-strict-overflow -Wstack-protector -O2 -g -DNDEBUG -g3 -D_FORTIFY_SOURCE=2 -MD -MT CMakeFiles/srclibs-rmlui.dir/libs/RmlUi/Source/Core/SystemInterface.cpp.obj -MF CMakeFiles/srclibs-rmlui.dir/libs/RmlUi/Source/Core/SystemInterface.cpp.obj.d -o CMakeFiles/srclibs-rmlui.dir/libs/RmlUi/Source/Core/SystemInterface.cpp.obj -c saigo_newlibUnvanquished/libs/RmlUi/Source/Core/SystemInterface.cpp
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module 'saigo_newlibUnvanquished/libs/RmlUi/Source/Core/SystemInterface.cpp'.
4.	Running pass 'X86 DAG->DAG Instruction Selection' on function '@_ZN3Rml15SystemInterface10LogMessageENS_3Log4TypeERKNSt3__112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEE'
 #0 0x0000775721e5bd97 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x265bd97)
 #1 0x0000775721e598fe llvm::sys::RunSignalHandlers() (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x26598fe)
 #2 0x0000775721e5b153 llvm::sys::CleanupOnSignal(unsigned long) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x265b153)
 #3 0x0000775721d90fa6 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #4 0x000077571f445330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
 #5 0x000077571f49eb2c pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x9eb2c)
 #6 0x000077571f44527e raise (/lib/x86_64-linux-gnu/libc.so.6+0x4527e)
 #7 0x000077571f4288ff abort (/lib/x86_64-linux-gnu/libc.so.6+0x288ff)
 #8 0x0000775721da414f (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x25a414f)
 #9 0x00007757247f43d8 llvm::X86TargetLowering::LowerGlobalTLSAddress(llvm::SDValue, llvm::SelectionDAG&) const X86ISelLowering.cpp:0:0
#10 0x0000775722843b7a (anonymous namespace)::SelectionDAGLegalize::LegalizeOp(llvm::SDNode*) LegalizeDAG.cpp:0:0
#11 0x0000775722842e83 llvm::SelectionDAG::Legalize() (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x3042e83)
#12 0x0000775722a0e81c llvm::SelectionDAGISel::CodeGenAndEmitDAG() (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x320e81c)
#13 0x0000775722a0c5f4 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x320c5f4)
#14 0x0000775722a09abf llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x3209abf)
#15 0x0000775722a072d9 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x32072d9)
#16 0x00007757223af988 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x2baf988)
#17 0x0000775722019e61 llvm::FPPassManager::runOnFunction(llvm::Function&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x2819e61)
#18 0x0000775722022191 llvm::FPPassManager::runOnModule(llvm::Module&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x2822191)
#19 0x000077572201a885 llvm::legacy::PassManagerImpl::run(llvm::Module&) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x281a885)
#20 0x00007757283ec00d clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x2fec00d)
#21 0x00007757288a072f clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x34a072f)
#22 0x0000775726e51997 clang::ParseAST(clang::Sema&, bool, bool) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x1a51997)
#23 0x00007757290c0876 clang::FrontendAction::Execute() (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x3cc0876)
#24 0x000077572902febf clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x3c2febf)
#25 0x000077572916241c clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x3d6241c)
#26 0x00005ff027175a28 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (saigo_newlibsaigo_newlib/bin/x86_64-nacl-clang+++0x14a28)
#27 0x00005ff027171f8d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#28 0x0000775728c77ed9 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::$_1>(long) Job.cpp:0:0
#29 0x0000775721d90ced llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (saigo_newlib/bin/../lib/libLLVM.so.21.0git+0x2590ced)
#30 0x0000775728c775df clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x38775df)
#31 0x0000775728c3285a clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x383285a)
#32 0x0000775728c32b67 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x3832b67)
#33 0x0000775728c52cd9 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (saigo_newlib/bin/../lib/libclang-cpp.so.21.0git+0x3852cd9)
#34 0x00005ff0271715d2 clang_main(int, char**, llvm::ToolContext const&) (saigo_newlibsaigo_newlib/bin/x86_64-nacl-clang+++0x105d2)
#35 0x00005ff027181997 main (saigo_newlibsaigo_newlib/bin/x86_64-nacl-clang+++0x20997)
#36 0x000077571f42a1ca (/lib/x86_64-linux-gnu/libc.so.6+0x2a1ca)
#37 0x000077571f42a28b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28b)
#38 0x00005ff02716fb3a _start (saigo_newlibsaigo_newlib/bin/x86_64-nacl-clang+++0xeb3a)
x86_64-nacl-clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
clang version 21.0.0git (https://chromium.googlesource.com/a/native_client/nacl-llvm-project-v10.git 9c7f0369cfdd591e580c5ccfc1f00fedee58029f)
Target: x86_64-unknown-nacl
Thread model: posix
InstalledDir: saigo_newlib/bin
Build config: +assertions
x86_64-nacl-clang++: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
x86_64-nacl-clang++: note: diagnostic msg: /tmp/SystemInterface-97bdbe.cpp
x86_64-nacl-clang++: note: diagnostic msg: /tmp/SystemInterface-97bdbe.sh
x86_64-nacl-clang++: note: diagnostic msg: 

********************

It doesn't crash when building the amd64 sgame though. As noticed it crashes when building RmlUi, the build errors on arm also happen when building RmlUi. Google-built Saigo has enabled assertions, while self-built one doesn't, that may explain why I didn't get the compiler crash when using my self-built Saigo. That PIE code is likely incomplete for NaCl in Saigo to begin with, hence the UNREACHABLE assertion we hit when compiling the RmlUi code.