I have no experience with llvm or clang, yet. From what I read clang is said to be easily embeddable Wikipedia-Clang, however, I did not find any tutorials about how to achi
I don't know about Clang but you might want to look at Ch:
http://www.softintegration.com/
This is described as an embeddable or stand-alone c/c++ interpreter. There is a Dr. Dobbs article with examples of embedding it here:
http://www.drdobbs.com/architecture-and-design/212201774
I haven't done more than play with it but it seems to be a stable and mature product. It's commercial, closed-source, but the "standard" version is described as free for both personal and commercial use. However, looking at the license it seems that "commercial" may only include internal company use, not embedding in a product that is then sold or distributed. (I'm not a lawyer, so clearly one should check with SoftIntegration to be certain of the license terms.)