Installing LLReve using Cmake. Unknown BISON_TARGET error - cmake

Question

I am getting the following error :
CMake Error at CMakeLists.txt:9 (BISON_TARGET):
Unknown CMake command "BISON_TARGET".
when I run the command :
cmake .. -GNinja
Please tell me what to do. I tried searching on google a lot and thus came up with the additions and finally ran the command :
cmake .. -D LLVM_DIR=/usr/lib/llvm-5.0/cmake/ -D FLEX_EXECUTABLE=/usr/local/Cellar/flex/2.5.37/bin/ -D FLEX_INCLUDE_DIR=/usr/local/Cellar/flex/2.5.37/include/ -D BISON_EXECUTABLE=/usr/bin/bison
but it still shows the same error :(.
Please someone help.

Answer 1

Your error is occurring because the BISON_TARGET function definition has not yet been supplied. This method, as commented, is supplied by FindBISON. The error indicates that either Bison was not found on your system (hopefully, you have it installed), or cmake was ran from the wrong directory. Bison is included in the top-level CMake file via:
find_package(BISON REQUIRED)
This line to include Bison must be called before using the BISON_TARGET CMake function. The LLReve instructions for compiling this repository are explicit about which directory to run the build commands in:
Go to the llreve directory and run
cd reve
mkdir build
cd build
cmake .. -GNinja
ninja
This would run on the CMake file in the llreve/reve directory, not the llreve/reve/reve directory. Please ensure you are running CMake from the correct location, as not running cmake on the top-level CMake file will often yield errors.