[PATCH] D131270: MC: make section classification a bit more thorough

Mon Aug 22 11:09:05 PDT 2022

nathanchance added a comment.

This patch breaks building the Linux kernel for RISC-V. A simplified reproducer:

  enum { true };
  __attribute__((__section__(".init.data"))) char *message;
  _Bool __attribute__((__section__(".init.data"))) initramfs_async = true;

  $ clang --version | head -1
  ClangBuiltLinux clang version 16.0.0 (https://github.com/llvm/llvm-project 73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6)

  $ clang --target=riscv64-linux-gnu -c -o /dev/null initramfs.i
  fatal error: error in backend: unable to write nop sequence of 7 bytes
  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: clang --target=riscv64-linux-gnu -c -o /dev/null initramfs.i
  1.      <eof> parser at end of file
  2.      Code generation
   #0 0x000055b56adaacf3 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3697cf3)
   #1 0x000055b56ada8d6e llvm::sys::RunSignalHandlers() (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3695d6e)
   #2 0x000055b56ad257af (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0
   #3 0x000055b56ad2573f llvm::CrashRecoveryContext::HandleExit(int) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x361273f)
   #4 0x000055b56ada5817 llvm::sys::Process::Exit(int, bool) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3692817)
   #5 0x000055b569a46662 (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x2333662)
   #6 0x000055b56ad2a619 llvm::report_fatal_error(llvm::Twine const&, bool) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3617619)
   #7 0x000055b56aa1a5a4 llvm::MCAssembler::writeSectionData(llvm::raw_ostream&, llvm::MCSection const*, llvm::MCAsmLayout const&) const (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x33075a4)
   #8 0x000055b56aa04c58 (anonymous namespace)::ELFWriter::writeObject(llvm::MCAssembler&, llvm::MCAsmLayout const&) ELFObjectWriter.cpp:0:0
   #9 0x000055b56aa03755 (anonymous namespace)::ELFSingleObjectWriter::writeObject(llvm::MCAssembler&, llvm::MCAsmLayout const&) ELFObjectWriter.cpp:0:0
  #10 0x000055b56aa1b4e6 llvm::MCAssembler::Finish() (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x33084e6)
  #11 0x000055b56aa3adb8 llvm::MCELFStreamer::finishImpl() (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3327db8)
  #12 0x000055b56bb93339 llvm::AsmPrinter::doFinalization(llvm::Module&) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x4480339)
  #13 0x000055b56a690909 llvm::FPPassManager::doFinalization(llvm::Module&) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x2f7d909)
  #14 0x000055b56a689f1c llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x2f76f1c)
  #15 0x000055b56b5f0fbd clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3eddfbd)
  #16 0x000055b56b9ecd1e clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
  #17 0x000055b56c2f1a3a clang::ParseAST(clang::Sema&, bool, bool) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x4bdea3a)
  #18 0x000055b56b92fc60 clang::FrontendAction::Execute() (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x421cc60)
  #19 0x000055b56b8a1b9f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x418eb9f)
  #20 0x000055b56b9e6182 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x42d3182)
  #21 0x000055b569a46138 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x2333138)
  #22 0x000055b569a43e7f ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
  #23 0x000055b56b71e522 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::$_1>(long) Job.cpp:0:0
  #24 0x000055b56ad2562c llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x361262c)
  #25 0x000055b56b71e07f clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x400b07f)
  #26 0x000055b56b6dd64f clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3fca64f)
  #27 0x000055b56b6dd8fe clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3fca8fe)
  #28 0x000055b56b6fa6a0 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x3fe76a0)
  #29 0x000055b569a4354b clang_main(int, char**) (/home/nathan/tmp/tmp.BkODB37lsK/install/llvm/73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6/bin/clang-16+0x233054b)
  #30 0x00007f078dabc2d0 (/usr/lib/libc.so.6+0x232d0)
  #31 0x00007f078dabc38a __libc_start_main (/usr/lib/libc.so.6+0x2338a)
  #32 0x000055b569a40aa5 _start /build/glibc/src/glibc/csu/../sysdeps/x86_64/start.S:117:0
  clang-16: error: clang frontend command failed with exit code 70 (use -v to see invocation)
  ClangBuiltLinux clang version 16.0.0 (https://github.com/llvm/llvm-project 73a9dfcee24df959b59a46d75dcbdc0bcfb50fe6)
  Target: riscv64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: ...
  clang-16: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

There is no issue at the direct parent.

  $ clang --version | head -1
  ClangBuiltLinux clang version 16.0.0 (https://github.com/llvm/llvm-project e41dd0205242af4f8e2a370d0346f24f0b0eb788)

  $ clang --target=riscv64-linux-gnu -c -o /dev/null initramfs.i

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131270/new/

https://reviews.llvm.org/D131270