Can not build lldb15.0.0 on i686 against older kernel (pre-4.1)

[satmandu]

14.x built fine. This might be related to this issue with llvm 13: https://bugs.llvm.org/show_bug.cgi?id=51917

Building llvm 15.0.0 on i686 gives me this error:

[7465/7686] Building CXX object tools/lldb/source/Plugins/Process/Linux/CMakeFiles/lldbPluginProcessLinux.dir/NativeThreadLinux.cpp.o
samu: job failed: CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/local/bin/ccache /usr/local/lib/ccache/bin/clang++ -DHAVE_ROUND -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/usr/local/tmp/crew/llvm.20220906180702.dir/builddir/tools/lldb/source/Plugins/Process/Linux -I/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux -I/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/builddir/tools/lldb/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/builddir/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/llvm/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/llvm/../clang/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/builddir/tools/lldb/../clang/include -I/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source -I/usr/local/tmp/crew/llvm.20220906180702.dir/builddir/tools/lldb/source -isystem /usr/local/include/libxml2 -latomic -fPIC -flto=thin -fvisibility-inlines-hidden -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -fdiagnostics-color -flto=thin -Wno-deprecated-declarations -Wno-unknown-pragmas -Wno-strict-aliasing -Wno-deprecated-register -Wno-vla-extension -O3 -DNDEBUG  -fno-exceptions -std=c++14 -MD -MT tools/lldb/source/Plugins/Process/Linux/CMakeFiles/lldbPluginProcessLinux.dir/Perf.cpp.o -MF tools/lldb/source/Plugins/Process/Linux/CMakeFiles/lldbPluginProcessLinux.dir/Perf.cpp.o.d -o tools/lldb/source/Plugins/Process/Linux/CMakeFiles/lldbPluginProcessLinux.dir/Perf.cpp.o -c /usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp
clang-14: warning: -latomic: 'linker' input unused [-Wunused-command-line-argument]
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:135:17: error: no member named 'aux_offset' in 'perf_event_mmap_page'
  metadata_page.aux_offset =
  ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:136:21: error: no member named 'data_offset' in 'perf_event_mmap_page'
      metadata_page.data_offset + metadata_page.data_size;
      ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:136:49: error: no member named 'data_size' in 'perf_event_mmap_page'
      metadata_page.data_offset + metadata_page.data_size;
                                  ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:137:17: error: no member named 'aux_size' in 'perf_event_mmap_page'
  metadata_page.aux_size = num_aux_pages * getpagesize();
  ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:140:41: error: no member named 'aux_size' in 'perf_event_mmap_page'
          DoMmap(nullptr, metadata_page.aux_size, PROT_READ, MAP_SHARED,
                          ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:141:32: error: no member named 'aux_offset' in 'perf_event_mmap_page'
                 metadata_page.aux_offset, "aux buffer")) {
                 ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:177:29: error: no member named 'data_offset' in 'perf_event_mmap_page'
              mmap_metadata.data_offset,
              ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:178:46: error: no member named 'data_size' in 'perf_event_mmap_page'
           static_cast<size_t>(mmap_metadata.data_size)};
                               ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:184:46: error: no member named 'aux_size' in 'perf_event_mmap_page'
           static_cast<size_t>(mmap_metadata.aux_size)};
                               ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:208:38: error: no member named 'data_size' in 'perf_event_mmap_page'
  uint64_t data_size = mmap_metadata.data_size;
                       ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:244:37: error: no member named 'aux_head' in 'perf_event_mmap_page'
  uint64_t aux_head = mmap_metadata.aux_head;
                      ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:301:47: error: no member named 'data_size' in 'perf_event_mmap_page'
  if (mmap_metadata.data_head < mmap_metadata.data_size)
                                ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:304:26: error: no member named 'data_size' in 'perf_event_mmap_page'
    return mmap_metadata.data_size; // The buffer has wrapped.
           ~~~~~~~~~~~~~ ^
/usr/local/tmp/crew/llvm.20220906180702.dir/lldb/source/Plugins/Process/Linux/Perf.cpp:310:8: warning: unused variable 'log' [-Wunused-variable]

[llvmbot]

@llvm/issue-subscribers-lldb

[labath]

@a20012251

Failures to build on kernels this old aren't completely surprising. We don't have an officially set minimum target version, but I doubt that anybody tests these configurations on a regular basis.

Still, if this is the only failure, then it should be fairly easy to make this work, perhaps by disabling the entire tracing feature in this setups. Could you create patch that does that?

[satmandu]

I'm not a CMake expert, but one way to deal with this might be to add a check for that kernel functionality in https://github.com/llvm/llvm-project/blob/main/lldb/source/Plugins/Process/Linux/CMakeLists.txt to surround the inclusion of https://github.com/llvm/llvm-project/blob/main/lldb/source/Plugins/Process/Linux/Perf.cpp using cmake's CheckStructHasMember functionality?

Something along the lines of using code like this?

CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" aux_head linux/perf_event.h HAVE_PERF_AUX_HEAD)
CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" aux_offset linux/perf_event.h HAVE_PERF_AUX_OFFSET)
CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" aux_size linux/perf_event.h HAVE_PERF_AUX_SIZE)
CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" data_offset linux/perf_event.h HAVE_PERF_DATA_OFFSET)
CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" data_size linux/perf_event.h HAVE_PERF_DATA_SIZE)

[labath]

Yes, that sounds reasonable. You probably don't have to check for every single member that's being used, checking the oldest one would suffice.

[satmandu]

I tried replacing https://github.com/llvm/llvm-project/blob/main/lldb/source/Plugins/Process/Linux/CMakeLists.txt with this:

include(CheckStructHasMember)
CHECK_STRUCT_HAS_MEMBER("struct perf_event_mmap_page" aux_head linux/perf_event.h HAVE_PERF_AUX_HEAD)
if(HAVE_PERF_AUX_HEAD)
add_lldb_library(lldbPluginProcessLinux
  IntelPTCollector.cpp
  IntelPTSingleBufferTrace.cpp
  IntelPTMultiCoreTrace.cpp
  IntelPTPerThreadProcessTrace.cpp
  IntelPTThreadTraceCollection.cpp
  NativeProcessLinux.cpp
  NativeRegisterContextLinux.cpp
  NativeRegisterContextLinux_arm.cpp
  NativeRegisterContextLinux_arm64.cpp
  NativeRegisterContextLinux_ppc64le.cpp
  NativeRegisterContextLinux_riscv64.cpp
  NativeRegisterContextLinux_s390x.cpp
  NativeRegisterContextLinux_x86_64.cpp
  NativeThreadLinux.cpp
  Perf.cpp
  Procfs.cpp
  SingleStepCheck.cpp

  LINK_LIBS
    lldbCore
    lldbHost
    lldbSymbol
    lldbTarget
    lldbUtility
    lldbPluginProcessPOSIX
    lldbPluginProcessUtility
  LINK_COMPONENTS
    Support
  )
else()
  add_lldb_library(lldbPluginProcessLinux
    IntelPTCollector.cpp
    IntelPTSingleBufferTrace.cpp
    IntelPTMultiCoreTrace.cpp
    IntelPTPerThreadProcessTrace.cpp
    IntelPTThreadTraceCollection.cpp
    NativeProcessLinux.cpp
    NativeRegisterContextLinux.cpp
    NativeRegisterContextLinux_arm.cpp
    NativeRegisterContextLinux_arm64.cpp
    NativeRegisterContextLinux_ppc64le.cpp
    NativeRegisterContextLinux_riscv64.cpp
    NativeRegisterContextLinux_s390x.cpp
    NativeRegisterContextLinux_x86_64.cpp
    NativeThreadLinux.cpp
    Procfs.cpp
    SingleStepCheck.cpp
  
    LINK_LIBS
      lldbCore
      lldbHost
      lldbSymbol
      lldbTarget
      lldbUtility
      lldbPluginProcessPOSIX
      lldbPluginProcessUtility
    LINK_COMPONENTS
      Support
    )
endif()

(It looks like aux{head,offset,size} and data{head,offset,size} were introduced together in Linux 4.1.)

[satmandu]

That doesn't appear to fix the issue...

-- Performing Test HAVE_STEADY_CLOCK -- success
-- Configuring incomplete, errors occurred!
See also "/usr/local/tmp/crew/llvm.20220907195444.dir/builddir/CMakeFiles/CMakeOutput.log".
See also "/usr/local/tmp/crew/llvm.20220907195444.dir/builddir/CMakeFiles/CMakeError.log".
�[1;31mllvm failed to build: �[1;31m`CREW_DISABLE_ENV_OPTIONS="1" bash -c LLVM_IAS=1 PATH=/usr/local/lib/ccache/bin:/usr/local/bin:/usr/bin:/bin LD=ld.lld             cmake -G Ninja             -DCMAKE_ASM_COMPILER_TARGET=i686-cros-linux-gnu             -DCMAKE_BUILD_TYPE=Release             -DCMAKE_C_COMPILER=$(which clang)             -DCMAKE_C_COMPILER_TARGET=i686-cros-linux-gnu             -DCMAKE_C_FLAGS='-latomic -fPIC -fuse-ld=mold -flto=thin'             -DCMAKE_CXX_COMPILER=$(which clang++)             -DCMAKE_CXX_FLAGS='-latomic -fPIC -fuse-ld=mold -flto=thin'             -DCMAKE_EXE_LINKER_FLAGS='-Wl,-znotext -flto=thin'             -DCMAKE_INSTALL_PREFIX=/usr/local             -DCMAKE_LINKER=$(which ld.lld)             -D_CMAKE_TOOLCHAIN_PREFIX=llvm-             -DCOMPILER_RT_BUILD_BUILTINS=ON             -DCOMPILER_RT_BUILD_LIBFUZZER=OFF             -DCOMPILER_RT_BUILD_SANITIZERS=OFF             -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON             -DLIBOMP_ENABLE_SHARED=ON             -DLIBOMP_INSTALL_ALIASES=OFF             -DLIBUNWIND_C_FLAGS='-fno-exceptions -funwind-tables'             -DLIBUNWIND_CXX_FLAGS='-fno-exceptions -funwind-tables'             -DLIBUNWIND_SUPPORTS_FNO_EXCEPTIONS_FLAG=ON             -DLIBUNWIND_SUPPORTS_FUNWIND_TABLES_FLAG=ON             -DLLVM_BINUTILS_INCDIR='/usr/local/include'             -DLLVM_BUILD_LLVM_DYLIB=ON             -DLLVM_CCACHE_BUILD=ON             -DLLVM_DEFAULT_TARGET_TRIPLE=i686-cros-linux-gnu             -DLLVM_ENABLE_FFI=ON             -DLLVM_ENABLE_LTO=Thin             -DLLVM_ENABLE_PROJECTS='clang;clang-tools-extra;libcxx;libcxxabi;libunwind;lldb;compiler-rt;lld;polly'             -DLLVM_ENABLE_RTTI=ON             -DLLVM_ENABLE_RUNTIME=openmp             -DLLVM_ENABLE_TERMINFO=ON             -DLLVM_INSTALL_UTILS=ON             -DLLVM_LIBDIR_SUFFIX=''             -DLLVM_LINK_LLVM_DYLIB=ON             -DLLVM_OPTIMIZED_TABLEGEN=ON             -DLLVM_TARGETS_TO_BUILD='all'             -DOPENMP_ENABLE_LIBOMPTARGET=OFF             -DPYTHON_EXECUTABLE=$(which python3)             -Wno-dev             ../llvm` exited with 1�[0m�[0m

[DavidSpickett]

-- Configuring incomplete, errors occurred!

I'm guessing this means there's some issue with your cmake not with the compilation part of it. It can be tricky to make these try_compile sorts of things verbose but the CMakeError.log is a decent place to start.

[satmandu]

Looks like we can't just remove Perf.cpp since then we get complaints during the lldb-server linking:

[7660/7685] Linking CXX executable bin/lldb-server
clang-14: warning: -latomic: 'linker' input unused [-Wunused-command-line-argument]
samu: job failed: : && /usr/local/bin/clang++ -latomic -fPIC -flto=thin -fvisibility-inlines-hidden -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -fdiagnostics-color -flto=thin -Wno-deprecated-declarations -Wno-unknown-pragmas -Wno-strict-aliasing -Wno-deprecated-register -Wno-vla-extension -O3 -DNDEBUG -Wl,-znotext -flto=thin -flto=thin    -Wl,--gc-sections tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/Acceptor.cpp.o tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/lldb-gdbserver.cpp.o tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/lldb-platform.cpp.o tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/lldb-server.cpp.o tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/LLDBServerUtilities.cpp.o tools/lldb/tools/lldb-server/CMakeFiles/lldb-server.dir/SystemInitializerLLGS.cpp.o -o bin/lldb-server  -Wl,-rpath,"\$ORIGIN/../lib"  -lpthread  lib/liblldbHost.a  lib/liblldbInitialization.a  lib/liblldbVersion.a  lib/liblldbPluginProcessLinux.a  lib/liblldbPluginObjectFileELF.a  lib/liblldbPluginInstructionARM.a  lib/liblldbPluginInstructionMIPS.a  lib/liblldbPluginInstructionMIPS64.a  lib/liblldbPluginProcessGDBRemote.a  /usr/local/lib/libz.so  lib/liblldbPluginProcessPOSIX.a  lib/liblldbCore.a  lib/liblldbSymbol.a  lib/liblldbTarget.a  lib/liblldbPluginProcessUtility.a  lib/liblldbInterpreter.a  lib/liblldbBreakpoint.a  lib/liblldbDataFormatters.a  lib/liblldbExpression.a  lib/liblldbPluginCPlusPlusLanguage.a  lib/liblldbPluginObjCLanguage.a  lib/liblldbCommands.a  lib/liblldbPluginObjectFileJIT.a  lib/liblldbPluginClangCommon.a  lib/liblldbPluginCPPRuntime.a  lib/liblldbPluginTypeSystemClang.a  lib/liblldbPluginAppleObjCRuntime.a  lib/liblldbPluginExpressionParserClang.a  lib/liblldbPluginSymbolFileDWARF.a  lib/liblldbPluginSymbolFilePDB.a  lib/liblldbPluginObjCRuntime.a  lib/liblldbPluginRenderScriptRuntime.a  lib/liblldbPluginSymbolFileNativePDB.a  lib/liblldbPluginObjectFilePDB.a  lib/liblldbCore.a  lib/liblldbSymbol.a  lib/liblldbTarget.a  lib/liblldbPluginProcessUtility.a  lib/liblldbInterpreter.a  lib/liblldbBreakpoint.a  lib/liblldbDataFormatters.a  lib/liblldbExpression.a  lib/liblldbPluginCPlusPlusLanguage.a  lib/liblldbPluginObjCLanguage.a  lib/liblldbCommands.a  lib/liblldbPluginObjectFileJIT.a  lib/liblldbPluginClangCommon.a  lib/liblldbPluginCPPRuntime.a  lib/liblldbPluginTypeSystemClang.a  lib/liblldbPluginAppleObjCRuntime.a  lib/liblldbPluginExpressionParserClang.a  lib/liblldbPluginSymbolFileDWARF.a  lib/liblldbPluginSymbolFilePDB.a  lib/liblldbPluginObjCRuntime.a  lib/liblldbPluginRenderScriptRuntime.a  lib/liblldbPluginSymbolFileNativePDB.a  lib/liblldbPluginObjectFilePDB.a  lib/liblldbCore.a  lib/liblldbSymbol.a  lib/liblldbTarget.a  lib/liblldbPluginProcessUtility.a  lib/liblldbInterpreter.a  lib/liblldbBreakpoint.a  lib/liblldbDataFormatters.a  lib/liblldbExpression.a  lib/liblldbPluginCPlusPlusLanguage.a  lib/liblldbPluginObjCLanguage.a  lib/liblldbCommands.a  lib/liblldbPluginObjectFileJIT.a  lib/liblldbPluginClangCommon.a  lib/liblldbPluginCPPRuntime.a  lib/liblldbPluginTypeSystemClang.a  lib/liblldbPluginAppleObjCRuntime.a  lib/liblldbPluginExpressionParserClang.a  lib/liblldbPluginSymbolFileDWARF.a  lib/liblldbPluginSymbolFilePDB.a  lib/liblldbPluginObjCRuntime.a  lib/liblldbPluginRenderScriptRuntime.a  lib/liblldbPluginSymbolFileNativePDB.a  lib/liblldbPluginObjectFilePDB.a  lib/liblldbCore.a  lib/liblldbSymbol.a  lib/liblldbTarget.a  lib/liblldbPluginProcessUtility.a  lib/liblldbInterpreter.a  lib/liblldbBreakpoint.a  lib/liblldbDataFormatters.a  lib/liblldbExpression.a  lib/liblldbPluginCPlusPlusLanguage.a  lib/liblldbPluginObjCLanguage.a  lib/liblldbCommands.a  lib/liblldbPluginObjectFileJIT.a  lib/liblldbPluginClangCommon.a  lib/liblldbPluginCPPRuntime.a  lib/liblldbPluginTypeSystemClang.a  lib/liblldbPluginAppleObjCRuntime.a  lib/liblldbPluginExpressionParserClang.a  lib/liblldbPluginSymbolFileDWARF.a  lib/liblldbPluginSymbolFilePDB.a  lib/liblldbPluginObjCRuntime.a  lib/liblldbPluginRenderScriptRuntime.a  lib/liblldbPluginSymbolFileNativePDB.a  lib/liblldbPluginObjectFilePDB.a  lib/liblldbCore.a  lib/liblldbSymbol.a  lib/liblldbTarget.a  lib/liblldbPluginProcessUtility.a  lib/liblldbInterpreter.a  lib/liblldbBreakpoint.a  lib/liblldbDataFormatters.a  lib/liblldbExpression.a  lib/liblldbPluginCPlusPlusLanguage.a  lib/liblldbPluginObjCLanguage.a  lib/liblldbCommands.a  lib/liblldbPluginObjectFileJIT.a  lib/liblldbPluginClangCommon.a  lib/liblldbPluginCPPRuntime.a  lib/liblldbPluginTypeSystemClang.a  lib/liblldbPluginAppleObjCRuntime.a  lib/liblldbPluginExpressionParserClang.a  lib/liblldbPluginSymbolFileDWARF.a  lib/liblldbPluginSymbolFilePDB.a  lib/liblldbPluginObjCRuntime.a  lib/liblldbPluginRenderScriptRuntime.a  lib/liblldbPluginSymbolFileNativePDB.a  lib/liblldbPluginObjectFilePDB.a  lib/liblldbVersion.a  lib/liblldbHost.a  /usr/local/lib/libxml2.so  /usr/local/lib/libedit.so  /usr/local/lib/liblzma.so  lib/liblldbUtility.a  -lpthread  lib/libclang-cpp.so.15  lib/libLLVM-15.so  -ldl && :
mold: error: undefined symbol: lldb_private::process_linux::LoadPerfTscConversionParameters()
>>> referenced by IntelPTCollector.cpp
>>>               /usr/local/tmp/lto-llvm-adf267.o:(lldb_private::process_linux::IntelPTCollector::FetchPerfTscConversionParameters())
mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::GetAuxBuffer() const
>>> referenced by IntelPTCollector.cpp
>>>               /usr/local/tmp/lto-llvm-adf267.o:(std::_Function_handler<void (unsigned long long, lldb_private::process_linux::IntelPTSingleBufferTrace&), lldb_private::process_linux::IntelPTCollector::GetState()::$_0>::_M_invoke(std::_Any_data const&, unsigned long long&&, lldb_private::process_linux::IntelPTSingleBufferTrace&))>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::_Function_handler<void (unsigned int, lldb_private::process_linux::IntelPTSingleBufferTrace&, lldb_private::process_linux::PerfEvent&), lldb_private::process_linux::IntelPTMultiCoreTrace::GetState()::$_2>::_M_invoke(std::_Any_data const&, unsigned int&&, lldb_private::process_linux::IntelPTSingleBufferTrace&, lldb_private::process_linux::PerfEvent&))>>> referenced by IntelPTPerThreadProcessTrace.cpp
>>>               /usr/local/tmp/lto-llvm-7e25a9.o:(std::_Function_handler<void (unsigned long long, lldb_private::process_linux::IntelPTSingleBufferTrace&), lldb_private::process_linux::IntelPTPerThreadProcessTrace::GetState()::$_0>::_M_invoke(std::_Any_data const&, unsigned long long&&, lldb_private::process_linux::IntelPTSingleBufferTrace&))>>> referenced 1 more times

mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::GetReadOnlyAuxBuffer()
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(lldb_private::process_linux::IntelPTMultiCoreTrace::TryGetBinaryData(lldb_private::TraceGetBinaryDataRequest const&))>>> referenced by IntelPTThreadTraceCollection.cpp
>>>               /usr/local/tmp/lto-llvm-3063fc.o:(lldb_private::process_linux::IntelPTThreadTraceCollection::TryGetBinaryData(lldb_private::TraceGetBinaryDataRequest const&))
mold: error: undefined symbol: lldb_private::process_linux::resource_handle::FileDescriptorDeleter::operator()(long*)
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(lldb_private::process_linux::IntelPTMultiCoreTrace::StartOnAllCores(lldb_private::TraceIntelPTStartRequest const&, lldb_private::NativeProcessProtocol&, llvm::Optional<int>))>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::pair<lldb_private::process_linux::IntelPTSingleBufferTrace, lldb_private::process_linux::PerfEvent>::~pair())>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::pair<lldb_private::process_linux::IntelPTSingleBufferTrace, lldb_private::process_linux::PerfEvent>::~pair())>>> referenced 4 more times

mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::DisableWithIoctl()
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::_Function_handler<void (unsigned int, lldb_private::process_linux::IntelPTSingleBufferTrace&), lldb_private::process_linux::IntelPTMultiCoreTrace::ProcessDidStop()::$_0>::_M_invoke(std::_Any_data const&, unsigned int&&, lldb_private::process_linux::IntelPTSingleBufferTrace&))
mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::GetReadOnlyDataBuffer()
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(lldb_private::process_linux::IntelPTMultiCoreTrace::TryGetBinaryData(lldb_private::TraceGetBinaryDataRequest const&))
mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::EnableWithIoctl()
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::_Function_handler<void (unsigned int, lldb_private::process_linux::IntelPTSingleBufferTrace&), lldb_private::process_linux::IntelPTMultiCoreTrace::ProcessWillResume()::$_1>::_M_invoke(std::_Any_data const&, unsigned int&&, lldb_private::process_linux::IntelPTSingleBufferTrace&))
mold: error: undefined symbol: lldb_private::process_linux::PerfEvent::GetEffectiveDataBufferSize() const
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::_Function_handler<void (unsigned int, lldb_private::process_linux::IntelPTSingleBufferTrace&, lldb_private::process_linux::PerfEvent&), lldb_private::process_linux::IntelPTMultiCoreTrace::GetState()::$_2>::_M_invoke(std::_Any_data const&, unsigned int&&, lldb_private::process_linux::IntelPTSingleBufferTrace&, lldb_private::process_linux::PerfEvent&))
mold: error: undefined symbol: lldb_private::process_linux::resource_handle::MmapDeleter::operator()(void*)
>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(lldb_private::process_linux::IntelPTMultiCoreTrace::StartOnAllCores(lldb_private::TraceIntelPTStartRequest const&, lldb_private::NativeProcessProtocol&, llvm::Optional<int>))>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(lldb_private::process_linux::IntelPTMultiCoreTrace::StartOnAllCores(lldb_private::TraceIntelPTStartRequest const&, lldb_private::NativeProcessProtocol&, llvm::Optional<int>))>>> referenced by IntelPTMultiCoreTrace.cpp
>>>               /usr/local/tmp/lto-llvm-fd2716.o:(std::pair<lldb_private::process_linux::IntelPTSingleBufferTrace, lldb_private::process_linux::PerfEvent>::~pair())>>> referenced 11 more times

Any other suggestions on a cleaner way to handle this?

[DavidSpickett]

I suggest asking the people who wrote that part of the code. It may be that removing that file makes the rest unusable, even if it would link.

Easiest way is to git blame the file then if you look at the commit on github it'll show with their username and you can tag them here.

[satmandu]

Looks like @a20012251 is the person to ask about this. Any ideas on the best way to fix this? A workaround in the code for when perf_event_mmap_page in linux/perf_event.h doesn't have aux_head might be best?

[satmandu]

I guess you can't do that easily in cpp, so is there a good way to bypass building the Perf file without breaking the rest of the build?