Link to LLVM failed

[xuantengh]

I'm trying to build comgr from source, with the following cmake config:

cmake -S . -B build \
-DCMAKE_BUILD_TYPE=Release \
-DAMDDeviceLibs_DIR=$HOME/opt/rocm/5.4.3/lib/cmake/AMDDeviceLibs \
-DLLD_DIR=$HOME/opt/llvm/15.0.7/lib/cmake/lld \
-DClang_DIR=$HOME/opt/llvm/15.0.7/lib/cmake/clang \
-DROCM_DIR=$HOME/opt/rocm/5.4.3/share/rocm/cmake \
-DCMAKE_INSTALL_PREFIX=$PWD/install

cmake --build build

There are linking errors reporting undefined references to LLVM library during building:

/usr/bin/ld: CMakeFiles/amd_comgr.dir/src/comgr-metadata.cpp.o: in function `COMGR::metadata::getMetadataRoot(COMGR::DataObject*, C
OMGR::DataMeta*)':
comgr-metadata.cpp:(.text+0x2b5): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x2cf): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x2f9): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x313): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x4ad): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x4c2): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x4ec): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x501): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x715): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x72f): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x759): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x773): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x8fd): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x917): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x941): undefined reference to `llvm::object::object_category()'
/usr/bin/ld: comgr-metadata.cpp:(.text+0x95b): undefined reference to `llvm::StringError::StringError(llvm::Twine const&, std::erro
r_code)'
/usr/bin/ld: CMakeFiles/amd_comgr.dir/src/comgr-metadata.cpp.o: in function `COMGR::metadata::getELFObjectFileBase(COMGR::DataObjec
t*)':

I'm using the latest version AMD LLVM and device libs from the amd-stg-open branch. The full build log is available build.log. Is there any approach to tackle this? Thanks in advance.

[xuantengh]

The AMD LLVM project is config as:

cmake -S llvm -B build -G "Ninja" \
-DCMAKE_BUILD_TYPE=Release \
-DCMAKE_C_COMPILER=gcc \
-DCMAKE_CXX_COMPILER=g++ \
-DBUILD_SHARED_LIBS \
-DLLVM_ENABLE_LIBCXX=ON \
-DLLVM_ENABLE_PROJECTS="llvm;clang;lld" \
-DLLVM_ENABLE_RUNTIMES="compiler-rt;libc;libcxx;libcxxabi" \
-DCMAKE_INSTALL_PREFIX=$HOME/opt/rocm/5.4.3 \
-DLLVM_TARGETS_TO_BUILD="X86;AMDGPU"
cmake --build build
cmake --build build --target install

This issue could be fixed by disabling the shared library support of the AMD LLVM project (i.e., removing the -DBUILD_SHARED_LIBS option). I'm not suring why enabling this option will fail comgr building.

[lamb-j]

Currently building Comgr against an LLVM with -DBUILD_SHARED_LIBS=ON is not supported. There has been an ongoing effort to switch to shared/dynamic libraries, and it is almost but not quite ready.

I will update here once shared library support is ready, but for now you should try building with static LLVM libraries.

[squid-f]

Hi. I am facing a similar issue.
I get undefined symbol errors like:

ld.lld: error: undefined symbol: llvm::cl::ResetAllOptionOccurrences()
>>> referenced by comgr.cpp:366 (/builddir/build/BUILD/ROCm-CompilerSupport-rocm-5.7.1/lib/comgr/src/comgr.cpp:366)
>>>               CMakeFiles/amd_comgr.dir/src/comgr.cpp.o:(COMGR::clearLLVMOptions())

Indeed by setting -DBUILD_SHARED_LIBS=OFF, the build does pass.

The strange thing is the Arch package does NOT use this: https://gitlab.archlinux.org/archlinux/packaging/packages/comgr/-/blob/a673a34303cc87e813784a7a905da539ee92ac06/PKGBUILD

What is the impact of using -DBUILD_SHARED_LIBS=OFF for the rest of the stack build?

[xuantengh]

What is the impact of using -DBUILD_SHARED_LIBS=OFF for the rest of the stack build?

I have not yet faced any issue related to this.

[squid-f]

Thanks @Huangxt57 for your prompt reply.
I have built the stack up to https://github.com/ROCm-Developer-Tools/clr to try to bring OpenCL to my RX6600. and it does not work (yet).
The thing is to build clr, -DBUILD_SHARED_LIBS=OFF is also required. Actually, I start getting a detection issue with clinfo provided by ROCm. As there is no .so created but a .a instead, should I point to this .a in the icd file?

[squid-f]

Hi. The build of rocm-clr with -DBUILD_SHARED_LIBS=OFF fails to provide OpenCL support; reported in ROCm/clr#26

I decided then to patch rocm-clr to be able to get libamdocl64.so :
rocm-compilersupport-5.7.1-allow-lld-undefined.patch.txt

What could be the drawback by doing so?

[lamb-j]

@squid-f What's your final objective here? Are you just trying to get a build of Comgr and CLR working together?

You should be able to build both CLR and Comgr with their default "BUILD_SHARED_LIBS" settings. I don't normally set either when building the two separate projects.

For CLR, I use something like the following to build:

cmake -DCLR_BUILD_HIP=ON -DCLR_BUILD_OCL=ON -DHIP_COMMON_DIR=/path/to/hip -DCMAKE_INSTALL_PREFIX=$PWD/install ..
make -j32
make install

For Comgr:

export LLVM_PROJECT=/path/to/llvm-project/build (AMD LLVM branch)
export DEVICE_LIBS=/path/to/llvm-project/amd/device-libs/build
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="$LLVM_PROJECT;$DEVICE_LIBS" ..

[squid-f]

Hi @lamb-j
My final goal is to bring OpenCL suppor to AMD GPU NAVI architectures to Mageia Linux.
For that, I have followed the Arch packaging strategy and built the following packages: Rocm-llvm, Rocm-cmake, Rocm-core, Hsakmt, Rocm-device-libs, Rocm-compilersupport (comgr), Rocm-runtime (hsa-rocr), Rocminfo, Rocm-clr.

As @Huangxt57 , Comgr doesn't build with -DBUILD_SHARED_LIBS=ON. But, if I use -DBUILD_SHARED_LIBS=OFF, I cannot build CLR later on...
So, I patched Comgr to buid it with -DBUILD_SHARED_LIBS=ON (or, as you, it is equivalent to build without setting it). However, my GPU is not yet detected as a device within the platform (as explained in ROCm/clr#26 ).

Any clue why?

Thanks

[Mystro256]

I'd probably suggest to follow Fedora if you need to stick to shared libs. Fedora uses the upstream LLVM release branches, but RadeonOpenCompute/llvm-project follows llvm-project upstream's trunk ('main" branch), so the API is unstable, defeating the benefit of shared libs. If you want a more stable LLVM experience, I highly recommend following Fedora in this regard.

If you can build with shared libs OFF, then you should be able to use RadeonOpenCompute/llvm-project without issue as long as they are from the same release branch, e.g. "5.7.x".

As for building from amd-stg-open, you'll have more of a mixed bag on what will and will not compile against clr. In theory, you should be able to build clr's develop branch against amd-stg-open, but your millage may vary.

[Mystro256]

-DLLD_DIR=$HOME/opt/llvm/15.0.7/lib/cmake/lld
-DClang_DIR=$HOME/opt/llvm/15.0.7/lib/cmake/clang \

I noticed you're using llvm 15, any reason the distro doesn't have 16 or 17 available?

Either way, I have some forks available if you need to use llvm upstream rather than RadeonOpenCompute/llvm-project:
https://github.com/Mystro256/ROCm-Device-Libs/branches
https://github.com/Mystro256/ROCm-CompilerSupport/branches

Note the llvm 17 branch should be the same as the official RadeonOpenCompute
And these are the branched used by Fedora since LLVM 14.

[squid-f]

Thanks @Mystro256 for stepping in.
The first post you are referring to, is not from me.
I do use LLVM17 from a rocm-llvm package, I have built specifically to build the rest of stack.
I have followed here the Arch approach.
The weird thing is it looks like Arch is able to build with shared libs and I can’t. Despite I use the exact same build flags… hence, the patch I had to develop.

[lamb-j]

I think the shared library issue is orthogonal to your issue. It's fine to build Comgr as a shared library. That's the default currently, and you shouldn't need any patch or BUILD_SHARED_LIBS options to have that working. It's also fine to build CLR as a shared library. Again the default, no patches or CMake variables needed.

The one thing you can't currently do is build LLVM as a shared library and use that when building Comgr. But you'll only hit that issue if you manually set BUILD_SHARED_LIBS=ON in your LLVM build (this is what @Huangxt57 hit in this original issue), because the LLVM default is static libraries.

[squid-f]

The one thing you can't currently do is build LLVM as a shared library and use that when building Comgr. But you'll only hit that issue if you manually set BUILD_SHARED_LIBS=ON in your LLVM build (this is what @Huangxt57 hit in this original issue), because the LLVM default is static libraries.

Hi.

Here are the flags are used to build rocm-llvm 5.7.1:

-G Ninja \
        -B build \
        -S "./llvm" \
        -DCMAKE_BUILD_TYPE=RelWithDebInfo \
        -DCMAKE_INSTALL_PREFIX=%{install_prefix} \
        -DLLVM_HOST_TRIPLE=%{_host} \
        -DLLVM_DEFAULT_TARGET_TRIPLE=%{_host} \
        -DLLVM_ENABLE_PROJECTS='llvm;clang;compiler-rt;lld' \
        -DLLVM_TARGETS_TO_BUILD='AMDGPU;NVPTX;X86' \
        -DCLANG_DEFAULT_LINKER=lld \
        -DLLVM_INSTALL_UTILS=ON \
        -DLLVM_ENABLE_BINDINGS=OFF \
        -DLLVM_LINK_LLVM_DYLIB=OFF \
        -DLLVM_BUILD_LLVM_DYLIB=OFF \
        -DLLVM_LINK_LLVM_DYLIB=OFF \
        -DLLVM_ENABLE_ASSERTIONS=ON \
        -DOCAMLFIND=NO \
        -DLLVM_ENABLE_OCAMLDOC=OFF \
        -DLLVM_INCLUDE_BENCHMARKS=OFF \
        -DLLVM_BUILD_TESTS=ON \
        -DLLVM_INCLUDE_TESTS=ON \
        -DCLANG_INCLUDE_TESTS=ON \
        -DLLVM_BINUTILS_INCDIR=%{_includedir}

However, the log output shows:

/usr/bin/cmake -Wno-dev -S . -B build -DCMAKE_CXX_FLAGS_RELWITHDEBINFO:STRING=-DNDEBUG -DCMAKE_C_FLAGS_RELWITHDEBINFO:STRING=-DNDEBUG -DCMAKE_CXX_FLAGS_RELEASE:STRING=-DNDEBUG -DCMAKE_C_FLAGS_RELEASE:STRING=-DNDEBUG -DCMAKE_INSTALL_DO_STRIP:BOOL=OFF -DCMAKE_INSTALL_LIBDIR:PATH=lib64 -DCMAKE_INSTALL_LIBEXECDIR:PATH=libexec -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_INSTALL_RUNSTATEDIR:PATH=/run -DCMAKE_INSTALL_SYSCONFDIR:PATH=/etc -DINCLUDE_INSTALL_DIR:PATH=/usr/include -DLIB_INSTALL_DIR:PATH=/usr/lib64 -DSYSCONF_INSTALL_DIR:PATH=/etc -DSHARE_INSTALL_PREFIX:PATH=/usr/share -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLIB_SUFFIX=64 -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON '-DCMAKE_MODULE_LINKER_FLAGS=-Wl,--as-needed  -Wl,-z,relro -Wl,-O1 -Wl,--build-id=sha1 -Wl,--enable-new-dtags' -DBUILD_SHARED_LIBS:BOOL=ON -DBUILD_STATIC_LIBS:BOOL=OFF -G Ninja -B build -S ./llvm -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=/usr/lib64/rocm/llvm -DLLVM_HOST_TRIPLE=x86_64-mageia-linux-gnu -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-mageia-linux-gnu '-DLLVM_ENABLE_PROJECTS=llvm;clang;compiler-rt;lld' '-DLLVM_TARGETS_TO_BUILD=AMDGPU;NVPTX;X86' -DCLANG_DEFAULT_LINKER=lld -DLLVM_INSTALL_UTILS=ON -DLLVM_ENABLE_BINDINGS=OFF -DLLVM_LINK_LLVM_DYLIB=OFF -DLLVM_BUILD_LLVM_DYLIB=OFF -DLLVM_LINK_LLVM_DYLIB=OFF -DLLVM_ENABLE_ASSERTIONS=ON -DOCAMLFIND=NO -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_INCLUDE_BENCHMARKS=OFF -DLLVM_BUILD_TESTS=ON -DLLVM_INCLUDE_TESTS=ON -DCLANG_INCLUDE_TESTS=ON -DLLVM_BINUTILS_INCDIR=/usr/include

So, it looks like somethings adds -DBUILD_SHARED_LIBS:BOOL=ON -DBUILD_STATIC_LIBS:BOOL=OFF
I will investigate whether a macro from my Build System does that.

[squid-f]

So, conclusion, indeed, my BS was changing the default setting of rocm-llvm, which was not built with BUILD_SHARED_LIBS=OFF
I fixed that to get rocm-llvm built with static libs.
I was then able to build ROCm-CompilerSupport with BUILD_SHARED_LIBS=ON without any patch.
I can now also build rocm-clr with BUILD_SHARED_LIBS=ON

The issue is solved for me.
Thanks @lamb-j @Mystro256

I might open another report as my GPU gfx1032 (AMD Radeon RX 6600) is not found by OpenCL, still...

[squid-f]

Hi.
I need to correct myself: thanks to rocm-llvm built with BUILD_SHARED_LIBS=OFF, I was able to build rocm-clr with BUILD_SHARED_LIBS=ON, AND, now, my GPU gfx1032 (AMD Radeon RX 6600) is found by OpenCL !
So, there is now a complete ROCm stack available for Mageia Linux.

Thanks again !

[lamb-j]

Nice work with the investigation @squid-f, and thanks for your efforts to port ROCm to Mageia.

Still leaving this ticket open, as @Huangxt57's original issue still exists (can't build Comgr against a shared-lib LLVM)

[lucmann]

Currently building Comgr against an LLVM with -DBUILD_SHARED_LIBS=ON is not supported. There has been an ongoing effort to switch to shared/dynamic libraries, and it is almost but not quite ready.

I will update here once shared library support is ready, but for now you should try building with static LLVM libraries.

Gentle ping, any news on this?

[lamb-j]

This project was shelved for a while, but I've actually recently picked it back up. So hopefully there may be news to share in the near future!

[lucmann]

static LLVM is so fat that I have to buy a bigger SSD before installing it 😭 Really look forward to shared library support

449M    /home/luc/gh/ROCm/llvm-project/clang
972M    /home/luc/gh/ROCm/llvm-project/llvm
1.7G    /home/luc/gh/ROCm/llvm-project/.git
118G    /home/luc/gh/ROCm/llvm-project/build
122G    /home/luc/gh/ROCm/llvm-project

[lamb-j]

What CMake command are you using to build LLVM? I'm guessing you're doing a Debug build? If a Release build is an option, it looks much smaller.

-DCMAKE_BUILD_TYPE=Release
-DLLVM_ENABLE_PROJECTS="clang;lld;clang-tools-extra;compiler-rt"

llvm-project$ du -hs * | sort -h
405M    clang
434M    amd
1.1G    llvm
8.3G    build

-DCMAKE_BUILD_TYPE=Debug
-DLLVM_ENABLE_PROJECTS="clang;lld;clang-tools-extra;compiler-rt"

llvm-project$ du -hs * | sort -h
405M    clang
434M    amd
1.1G    llvm
156G    build

[lucmann]

@lamb-j yeah, I was doing a RelWithDebInfo build. My cmake command was:

cmake -S llvm -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DCMAKE_INSTALL_PREFIX=~/.local/rocm/6.2.0/llvm -DLLVM_ENABLE_PROJECTS="clang;lld;llvm" -DLLVM_TARGETS_TO_BUILD="BPF;AMDGPU;host" -DLLVM_LIBDIR_SUFFIX=64 -DLLVM_BUILD_LLVM_DYLIB=OFF -DBUILD_SHARED_LIBS=OFF -DLLVM_USE_LINKER=gold

I just switch to Release build and the resulting size has become acceptable for me now.

449M    clang
972M    llvm
4.1G    build

TBH, I am a little surprised there is such a substantial difference on size and speed between these two types of build. Anyway thank you very much for the time and hint.

[lamb-j]

@lucmann I was also surprised the difference was that large. There are some other options you could try as well, such as RelWithDebInfo or MinSizeRel: https://llvm.org/docs/CMake.html#frequently-used-cmake-variables

Also to clarify, since you're already building from source, it is possible to build the AMD fork of LLVM with -DBUILD_SHARED_LIBS=ON. The ROCm components that rely on it are set up to handle that.

We have it disabled (and use static LLVM libs) by default because of edge cases/issues when using LLVM as a shared library alongside Mesa or OpenGL.

But if you're application doesn't rely on Mesa/OpenGL, it's likely you could build and use the shared libraries without any issues.