Could I get one single bc file from multiple files？（which may have a real big amount of files including .c/.h/.hpp）

[mshockwave]

I’m not sure how good is wllvm but Clang already can do this out of the box through LTO + embedded bitcode:

How to use LLVM-test-suite to experiment with alias analysis?

I guess you mean producing a single .bc file for the entire project comprises of potentially thousands of C/C++ files. If that’s the case you definitely need to use LTO (Link-Time Optimization) to produce that kind of “merged” bitcode file. (Theoretically you can use llvm-link but my experiences showed that that tool didn’t scale up really well) Here are the steps: First, add the following compiler flag: -flto. In the case of CMake you can add something like -DCMAKE_C_FLAGS="-flto" / -DCMAKE…