18.x: undefined symbol: main for llvm-omp-kernel-replay and llvm-omp-device-info

[liam-clink]

I'm building release/18.x using this invocation:

cmake -S llvm -B build -G Ninja -DLLVM_ENABLE_PROJECTS="bolt;clang;clang-tools-extra;compiler-rt;cross-project-tests;libclc;lld;lldb;mlir;polly;pstl;openmp" -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_LINKER=lld -DLLVM_TARGETS_TO_BUILD="AArch64;AMDGPU;ARM;AVR;WebAssembly;X86" -DLLVM_ENABLE_SPHINX=true -DLLVM_ENABLE_RTTI=true -DLLVM_INSTALL_UTILS=true -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind"

The error I'm getting:

[66/6814] Linking CXX executable bin/llvm-omp-kernel-replay
FAILED: bin/llvm-omp-kernel-replay 
: && /usr/local/gcc-12/bin/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -fno-semantic-interposition -fdata-sections -O3 -DNDEBUG -fuse-ld=lld -Wl,--color-diagnostics    -Wl,--gc-sections  -flto projects/openmp/libomptarget/tools/kernelreplay/CMakeFiles/llvm-omp-kernel-replay.dir/llvm-omp-kernel-replay.cpp.o -o bin/llvm-omp-kernel-replay  -Wl,-rpath,"\$ORIGIN/../lib:/home/liam/repos/llvm-project/build/lib:"  lib/libLLVMSupport.a  lib/libomptarget.so.18.1  lib/libomp.so  -lm  lib/libLLVMObject.a  lib/libLLVMIRReader.a  lib/libLLVMBitReader.a  lib/libLLVMAsmParser.a  lib/libLLVMCore.a  lib/libLLVMRemarks.a  lib/libLLVMBitstreamReader.a  lib/libLLVMMCParser.a  lib/libLLVMMC.a  lib/libLLVMDebugInfoCodeView.a  lib/libLLVMTextAPI.a  lib/libLLVMBinaryFormat.a  lib/libLLVMTargetParser.a  lib/libLLVMSupport.a  -lrt  -ldl  -lm  /usr/lib/x86_64-linux-gnu/libz.so  /usr/lib/x86_64-linux-gnu/libzstd.so  /usr/lib/x86_64-linux-gnu/libtinfo.so  lib/libLLVMDemangle.a && :
ld.lld: error: undefined symbol: main
>>> referenced by /lib/x86_64-linux-gnu/crt1.o:(_start)
collect2: error: ld returned 1 exit status
[72/6814] Linking CXX executable bin/llvm-omp-device-info
FAILED: bin/llvm-omp-device-info 
: && /usr/local/gcc-12/bin/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -fno-semantic-interposition -fdata-sections -O3 -DNDEBUG -fuse-ld=lld -Wl,--color-diagnostics    -Wl,--gc-sections  -flto projects/openmp/libomptarget/tools/deviceinfo/CMakeFiles/llvm-omp-device-info.dir/llvm-omp-device-info.cpp.o -o bin/llvm-omp-device-info  -Wl,-rpath,"\$ORIGIN/../lib:/home/liam/repos/llvm-project/build/lib:"  lib/libomptarget.so.18.1  lib/libomp.so  -lm  lib/libLLVMObject.a  lib/libLLVMIRReader.a  lib/libLLVMBitReader.a  lib/libLLVMAsmParser.a  lib/libLLVMCore.a  lib/libLLVMRemarks.a  lib/libLLVMBitstreamReader.a  lib/libLLVMMCParser.a  lib/libLLVMMC.a  lib/libLLVMDebugInfoCodeView.a  lib/libLLVMTextAPI.a  lib/libLLVMBinaryFormat.a  lib/libLLVMTargetParser.a  lib/libLLVMSupport.a  -lrt  -ldl  -lm  /usr/lib/x86_64-linux-gnu/libz.so  /usr/lib/x86_64-linux-gnu/libzstd.so  /usr/lib/x86_64-linux-gnu/libtinfo.so  lib/libLLVMDemangle.a && :
ld.lld: error: undefined symbol: main
>>> referenced by /lib/x86_64-linux-gnu/crt1.o:(_start)
collect2: error: ld returned 1 exit status
[99/6814] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/MveEmitter.cpp.o
ninja: build stopped: subcommand failed.

Not sure what other info I could give that would help. Just let me know. Funny how I always seem to have a problem building libOMP...

[llvmbot]

@llvm/issue-subscribers-openmp

Author: Liam Clink (liam-clink)

I'm building release/18.x using this invocation:

cmake -S llvm -B build -G Ninja -DLLVM_ENABLE_PROJECTS="bolt;clang;clang-tools-extra;compiler-rt;cross-project-tests;libclc;lld;lldb;mlir;polly;pstl;openmp" -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_LINKER=lld -DLLVM_TARGETS_TO_BUILD="AArch64;AMDGPU;ARM;AVR;WebAssembly;X86" -DLLVM_ENABLE_SPHINX=true -DLLVM_ENABLE_RTTI=true -DLLVM_INSTALL_UTILS=true -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind"

The error I'm getting:

[66/6814] Linking CXX executable bin/llvm-omp-kernel-replay
FAILED: bin/llvm-omp-kernel-replay 
: && /usr/local/gcc-12/bin/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -fno-semantic-interposition -fdata-sections -O3 -DNDEBUG -fuse-ld=lld -Wl,--color-diagnostics    -Wl,--gc-sections  -flto projects/openmp/libomptarget/tools/kernelreplay/CMakeFiles/llvm-omp-kernel-replay.dir/llvm-omp-kernel-replay.cpp.o -o bin/llvm-omp-kernel-replay  -Wl,-rpath,"\$ORIGIN/../lib:/home/liam/repos/llvm-project/build/lib:"  lib/libLLVMSupport.a  lib/libomptarget.so.18.1  lib/libomp.so  -lm  lib/libLLVMObject.a  lib/libLLVMIRReader.a  lib/libLLVMBitReader.a  lib/libLLVMAsmParser.a  lib/libLLVMCore.a  lib/libLLVMRemarks.a  lib/libLLVMBitstreamReader.a  lib/libLLVMMCParser.a  lib/libLLVMMC.a  lib/libLLVMDebugInfoCodeView.a  lib/libLLVMTextAPI.a  lib/libLLVMBinaryFormat.a  lib/libLLVMTargetParser.a  lib/libLLVMSupport.a  -lrt  -ldl  -lm  /usr/lib/x86_64-linux-gnu/libz.so  /usr/lib/x86_64-linux-gnu/libzstd.so  /usr/lib/x86_64-linux-gnu/libtinfo.so  lib/libLLVMDemangle.a && :
ld.lld: error: undefined symbol: main
>>> referenced by /lib/x86_64-linux-gnu/crt1.o:(_start)
collect2: error: ld returned 1 exit status
[72/6814] Linking CXX executable bin/llvm-omp-device-info
FAILED: bin/llvm-omp-device-info 
: && /usr/local/gcc-12/bin/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -fno-semantic-interposition -fdata-sections -O3 -DNDEBUG -fuse-ld=lld -Wl,--color-diagnostics    -Wl,--gc-sections  -flto projects/openmp/libomptarget/tools/deviceinfo/CMakeFiles/llvm-omp-device-info.dir/llvm-omp-device-info.cpp.o -o bin/llvm-omp-device-info  -Wl,-rpath,"\$ORIGIN/../lib:/home/liam/repos/llvm-project/build/lib:"  lib/libomptarget.so.18.1  lib/libomp.so  -lm  lib/libLLVMObject.a  lib/libLLVMIRReader.a  lib/libLLVMBitReader.a  lib/libLLVMAsmParser.a  lib/libLLVMCore.a  lib/libLLVMRemarks.a  lib/libLLVMBitstreamReader.a  lib/libLLVMMCParser.a  lib/libLLVMMC.a  lib/libLLVMDebugInfoCodeView.a  lib/libLLVMTextAPI.a  lib/libLLVMBinaryFormat.a  lib/libLLVMTargetParser.a  lib/libLLVMSupport.a  -lrt  -ldl  -lm  /usr/lib/x86_64-linux-gnu/libz.so  /usr/lib/x86_64-linux-gnu/libzstd.so  /usr/lib/x86_64-linux-gnu/libtinfo.so  lib/libLLVMDemangle.a && :
ld.lld: error: undefined symbol: main
>>> referenced by /lib/x86_64-linux-gnu/crt1.o:(_start)
collect2: error: ld returned 1 exit status
[99/6814] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/MveEmitter.cpp.o
ninja: build stopped: subcommand failed.

Not sure what other info I could give that would help. Just let me know. Funny how I always seem to have a problem building libOMP...

[shiltian]

This should be due to the wrong signature of the main function.

Update: It doesn't look like the case, since TableGen and FileCheck also use the same signature. Can you print the symbol table of the two object files that contains main function?

[shiltian]

Is it still the issue?

[vincentloechner]

I came upon this issue, when I try to compile on my debian (Bookworm) I get the same error. For the two bin/ llvm-omp-kernel-replay and llvm-omp-device-info : undefined symbol main when trying to link.
I tried to build llvm18 (tags/llvmorg-18.1.8) with openmp, cuda, and mlir activated (also tried without cuda it's the same).

$ CC=gcc-10 CXX=g++-10 CUDA_PATH=/usr/local/cuda-11.8 cmake -G Ninja ../llvm -DLLVM_ENABLE_PROJECTS="mlir;clang;openmp" -DLLVM_TARGETS_TO_BUILD="host;NVPTX" -DCMAKE_BUILD_TYPE=Release -DMLIR_ENABLE_BINDINGS_PYTHON=True -DBUILD_SHARED_LIBS=True -DLLVM_USE_LINKER=lld -DCMAKE_INSTALL_PREFIX=$(pwd)/../.. -DLLVM_INSTALL_UTILS=ON -DMLIR_ENABLE_CUDA_RUNNER=True -DCMAKE_CUDA_COMPILER="/usr/local/cuda-11.8/bin/nvcc" -DCMAKE_CUDA_FLAGS_INIT="-ccbin gcc-10"

$ ninja -j 4
[...]

$ /usr/bin/g++-10 -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -fno-semantic-interposition -fdata-sections -O3 -DNDEBUG -fuse-ld=lld     -Wl,--gc-sections  -flto projects/openmp/libomptarget/tools/deviceinfo/CMakeFiles/llvm-omp-device-info.dir/llvm-omp-device-info.cpp.o -o bin/llvm-omp-device-info  -Wl,-rpath,"\$ORIGIN/../lib:"  lib/libomptarget.so.18.1  lib/libomp.so  -lm  -ldl  lib/libLLVMObject.so.18.1  lib/libLLVMSupport.so.18.1  -Wl,-rpath-link,[...]/llvm-project/build_cuda/lib
ld.lld: error: undefined symbol: main
>>> referenced by /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/Scrt1.o:(_start)
collect2: error: ld returned 1 exit status
$ nm projects/openmp/libomptarget/tools/deviceinfo/CMakeFiles/llvm-omp-device-info.dir/llvm-omp-device-info.cpp.o
00000000 T main
         U omp_get_num_devices
         U __tgt_init_all_rtls
         U __tgt_print_device_info
         U __tgt_register_lib
         U __tgt_unregister_lib

The issue remains after applying patch #99733