Build issue on Linux (Ubuntu 20)

[buchs]

# cmake .
-- Found LLVM 16.0.4
-- Using LLVMConfig.cmake in: /usr/lib/llvm-16/cmake
-- Building with -fPIC
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
lib_lldb
    linked by target "lldb-mi" in directory /root/lldb-mi/src

-- Configuring incomplete, errors occurred!
See also "/root/lldb-mi/CMakeFiles/CMakeOutput.log".
See also "/root/lldb-mi/CMakeFiles/CMakeError.log".

Note, for my system I have Clang 15 installed along side Clang 16. The former is linked through commands like clang, clang++, cc and c++. So I define these environment variables:

export CMAKE_C_COMPILER_ID='Clang'
export CMAKE_C_COMPILER='/usr/bin/clang-16'
export CMAKE_CXX_COMPILER_ID='Clang'
export CMAKE_CXX_COMPILER='/usr/bin/clang++-16'
export LLDB_DEBUGSERVER_PATH='/usr/lib/llvm-16/lib/liblldb'

[sunshaoce]

When building LLVM, did you build lldb?

 -DLLVM_ENABLE_PROJECTS="clang;lldb"

[buchs]

Yes, lldb was built for the LLVM-16 toolchain. It was not for -15. But, to be clear, I am just using the apt package:

llvm_version='16'
curl -sS https://apt.llvm.org/llvm.sh -o llvm_sh
chmod +x llvm_sh
./llvm_sh $llvm_version all  &> /dev/null  # too much noise
rm llvm_sh
apt-get -qq install clang-format-$llvm_version

[sunshaoce]

I have tested it, and indeed it cannot be done this way. You can only build LLVM manually and then build lldb-mi.

llvm_path='~/llvm'

git clone https://github.com/llvm/llvm-project.git --depth=1 -b release/16.x
cd llvm-project
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=$llvm_path  -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;lldb" -DCMAKE_CXX_COMPILER=clang++-15 -G Ninja ../llvm
ninja install

cd ../..

git clone https://github.com/lldb-tools/lldb-mi.git --depth=1
cd lldb-mi
mkdir build
cd build
cmake -DCMAKE_PREFIX_PATH=$llvm_path -DCMAKE_CXX_COMPILER=clang++-15 -DCMAKE_INSTALL_PREFIX=$llvm_path -GNinja ..
ninja install

[buchs]

OK, thanks for looking into it.

[mikebeaton]

@buchs - On Ubuntu avoiding this error just requires sudo apt install -y liblldb-15-dev, or whatever your correct version is. This avoids needing to build llvm yourself. apt list --installed | grep liblldb to see what version of lldb you have installed.

[vibrys]

I've just compiled lldb-mi on ubuntu.20.04. I happened to use llvm-18.1.8 that was installed through https://apt.llvm.org/llvm.sh script.

I did following steps to compile/install lldb-mi:

  prompt# apt install libcurl4-openssl-dev libedit-dev libzstd-dev
  prompt# apt install liblldb-18-dev
  prompt# mkdir Build-18-a6c8c66 && cd Build-18-a6c8c66
  prompt# /opt/cmake-3.29.3/bin/cmake -DLLVM_DIR=/lib/llvm-18/cmake -DCMAKE_INSTALL_PREFIX=/opt/lldb-18-mi-a6c8c66 ../ 2>&1 | tee cmake.log

unfortunatelly, lldb-mi crashes. Here are the details

As mentioned, although lldb-mi compilation succeeded, the cmake command's log keeps one quite strange line:

  -- Looking for os_signpost_interval_begin - not found
  -- Can't find LLVM shared library, falling back to static linking LLVMSupport    <--- this one
  -- Configuring done (4.4s)
  -- Generating done (0.0s)
  -- Build files have been written to: /usr/src/lldb-mi/Build

I have 2 questions:

1. if you happen to use lldb-mi on ubuntu (preferably 20.04) did you notice such line your configs?
2. which llvm version did you succeed lldb-mi to run against?

[vibrys]

maybe one more technicality:

ldd `which lldb-mi`
	linux-vdso.so.1 (0x00007ffc0a59c000)
	liblldb-18.so.1 => /usr/lib/llvm-18/lib/liblldb-18.so.1 (0x00007f1670039000)
	libtinfo.so.6 => /lib/x86_64-linux-gnu/libtinfo.so.6 (0x00007f166ffee000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f166ffcb000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f166ffc5000)
	libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f166fde3000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f166fc94000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f166fc77000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f166fa85000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f167129c000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f166fa69000)
	libpython3.8.so.1.0 => /lib/x86_64-linux-gnu/libpython3.8.so.1.0 (0x00007f166f513000)
	libcurl.so.4 => /lib/x86_64-linux-gnu/libcurl.so.4 (0x00007f166f480000)
	libpanel.so.6 => /lib/x86_64-linux-gnu/libpanel.so.6 (0x00007f166f479000)
	libncurses.so.6 => /lib/x86_64-linux-gnu/libncurses.so.6 (0x00007f166f44e000)
	libxml2.so.2 => /lib/x86_64-linux-gnu/libxml2.so.2 (0x00007f166f294000)
	libedit.so.2 => /lib/x86_64-linux-gnu/libedit.so.2 (0x00007f166f25c000)
	libclang-cpp.so.18.1 => /usr/lib/llvm-18/lib/../lib/libclang-cpp.so.18.1 (0x00007f166b35d000)
	libLLVM-18.so.18.1 => /lib/x86_64-linux-gnu/libLLVM-18.so.18.1 (0x00007f1663d65000)
	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f1663d35000)
	libutil.so.1 => /lib/x86_64-linux-gnu/libutil.so.1 (0x00007f1663d30000)
	libnghttp2.so.14 => /lib/x86_64-linux-gnu/libnghttp2.so.14 (0x00007f1663d06000)
	libidn2.so.0 => /lib/x86_64-linux-gnu/libidn2.so.0 (0x00007f1663ce5000)
	librtmp.so.1 => /lib/x86_64-linux-gnu/librtmp.so.1 (0x00007f1663cc5000)
	libssh.so.4 => /lib/x86_64-linux-gnu/libssh.so.4 (0x00007f1663c56000)
	libpsl.so.5 => /lib/x86_64-linux-gnu/libpsl.so.5 (0x00007f1663c41000)
	libssl.so.1.1 => /lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f1663bae000)
	libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f16638d7000)
	libgssapi_krb5.so.2 => /lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f166388a000)
	libldap_r-2.4.so.2 => /lib/x86_64-linux-gnu/libldap_r-2.4.so.2 (0x00007f1663834000)
	liblber-2.4.so.2 => /lib/x86_64-linux-gnu/liblber-2.4.so.2 (0x00007f1663823000)
	libbrotlidec.so.1 => /lib/x86_64-linux-gnu/libbrotlidec.so.1 (0x00007f1663813000)
	libicuuc.so.66 => /lib/x86_64-linux-gnu/libicuuc.so.66 (0x00007f166362d000)
	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f1663604000)
	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f16635ea000)
	libffi.so.7 => /lib/x86_64-linux-gnu/libffi.so.7 (0x00007f16635de000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f16635d2000)
	libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007f1663529000)
	libunistring.so.2 => /lib/x86_64-linux-gnu/libunistring.so.2 (0x00007f16633a7000)
	libgnutls.so.30 => /lib/x86_64-linux-gnu/libgnutls.so.30 (0x00007f16631d1000)
	libhogweed.so.5 => /lib/x86_64-linux-gnu/libhogweed.so.5 (0x00007f166319a000)
	libnettle.so.7 => /lib/x86_64-linux-gnu/libnettle.so.7 (0x00007f166315e000)
	libgmp.so.10 => /lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f16630da000)
	libkrb5.so.3 => /lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f1662ffd000)
	libk5crypto.so.3 => /lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f1662fcc000)
	libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f1662fc5000)
	libkrb5support.so.0 => /lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f1662fb6000)
	libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f1662f98000)
	libsasl2.so.2 => /lib/x86_64-linux-gnu/libsasl2.so.2 (0x00007f1662f7b000)
	libgssapi.so.3 => /lib/x86_64-linux-gnu/libgssapi.so.3 (0x00007f1662f36000)
	libbrotlicommon.so.1 => /lib/x86_64-linux-gnu/libbrotlicommon.so.1 (0x00007f1662f13000)
	libicudata.so.66 => /lib/x86_64-linux-gnu/libicudata.so.66 (0x00007f1661452000)
	libp11-kit.so.0 => /lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f166131a000)
	libtasn1.so.6 => /lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f1661304000)
	libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f16612fd000)
	libheimntlm.so.0 => /lib/x86_64-linux-gnu/libheimntlm.so.0 (0x00007f16612f1000)
	libkrb5.so.26 => /lib/x86_64-linux-gnu/libkrb5.so.26 (0x00007f166125e000)
	libasn1.so.8 => /lib/x86_64-linux-gnu/libasn1.so.8 (0x00007f16611b6000)
	libhcrypto.so.4 => /lib/x86_64-linux-gnu/libhcrypto.so.4 (0x00007f166117e000)
	libroken.so.18 => /lib/x86_64-linux-gnu/libroken.so.18 (0x00007f1661165000)
	libwind.so.0 => /lib/x86_64-linux-gnu/libwind.so.0 (0x00007f166113b000)
	libheimbase.so.1 => /lib/x86_64-linux-gnu/libheimbase.so.1 (0x00007f1661129000)
	libhx509.so.5 => /lib/x86_64-linux-gnu/libhx509.so.5 (0x00007f16610d9000)
	libsqlite3.so.0 => /lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f1660fb0000)
	libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f1660f75000)

[vibrys]

using @KonanTheLibrarian 's script from #90 (here), didn't help here unfortunately. Then I've used the same script to compile lldb-mi against llvm-17 and .... it works correct! Also I DO NOT observe following line from cmake tool this time (please see above):

-- Can't find LLVM shared library, falling back to static linking LLVMSupport

[essisore]

using @KonanTheLibrarian 's script from #90 (here), didn't help here unfortunately. Then I've used the same script to compile lldb-mi against llvm-17 and .... it works correct! Also I DO NOT observe following line from cmake tool this time (please see above):

-- Can't find LLVM shared library, falling back to static linking LLVMSupport

In the src/CMakeLists.txt (Line 88) of the lldb-mi project, the current find_library command exclusively searches for a dynamic library named libLLVM.so. This causes build failures in LLVM 18 environments (e.g., Ubuntu/Debian-based systems) where the standard installation path contains versioned library names:

/usr/lib/llvm-18/lib/libLLVM-18.so  # Versioned full name
/usr/lib/llvm-18/lib/libLLVM.so     # Common symlink (may be missing)

Implemented Fix

Explicitly specify the versioned library name for precise matching:

find_library(
    lib_llvm_shared
    NAMES LLVM-18  # Explicit versioned target
    HINTS ${LLVM_LIBRARY_DIRS}
    DOC "Path to LLVM shared library"
)

This modification ensures compatibility with LLVM 18’s default installation pattern by prioritizing libLLVM-18.so.