Calc is an arithmetic expression language written using LLVM-17
mkdir build
cd build
cmake -GNinja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DLLVM_DIR=<path to llvm installation configuration> ../
ninja
cd build/src
calc "with a: a*3" | llc –filetype=obj -relocation-model=pic –o=expr.o
clang -o expr expr.o rtcalc.c
expr