cmake error encountered when build clang-query

Question

I encountered the following error when I was trying to build clang-query.

parallels@ubuntu18:~/myllvm/llvm/tools/clang/tools/extra/clang-query$ cmake .
-- The C compiler identification is GNU 7.3.0
-- The CXX compiler identification is GNU 7.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:6 (add_clang_library):
Unknown CMake command "add_clang_library".


CMake Warning (dev) in CMakeLists.txt:
No cmake_minimum_required command is present.  A line of code such as

    cmake_minimum_required(VERSION 3.13)

should be added at the top of the file.  The version specified may be lower
if you wish to support older CMake versions for this project.  For more
information run "cmake --help-policy CMP0000".
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Configuring incomplete, errors occurred!
See also "/home/parallels/myllvm/llvm/tools/clang/tools/extra/clang-query/CMakeFiles/CMakeOutput.log".

I'm confused about where should I run cmake cmd.

Answer 1

If you clone llvm-project from GitHub, you can follow LLVM's guide.

git clone https://github.com/llvm/llvm-project.git
cd llvm-project
mkdir build
cd build
cmake -DLLVM_ENABLE_PROJECTS="clang-tools-extra" ../llvm

Then run make clang-query to build it.