Hi everyone, Earlier this year, when I was working on the Python script interpreter, I thought it would be interesting to see what it would take to support other scripting languages in LLDB. Lua, being designed to be embedded, quickly came to mind. The idea remained in the back of my head, but I never really got around to it, until now.
I was pleasantly surprised to see that it only took me a few hours to create a basic but working prototype. It supports running single commands as well as an interactive interpreter and has access to most of the SB API through bindings generated by SWIG. Of course it's far from complete. Before I invest more time in this, I'm curious to hear what the community thinks about adding support for another scripting language to LLDB. Do we need both Lua and Python? Here are some of the reasons off the top of my head as to why the answer might be "yes": - The cost for having another scripting language is pretty small. The Lua script interpreter is very simple and SWIG can reuse the existing interfaces to generate the bindings. - LLDB is designed to support multiple script interpreters, but in reality we only have one. Actually exercising this property ensures that we don't unintentionally break that design assumptions. - The Python script interpreter is complex. It's hard to figure out what's really needed to support another language. The Lua script interpreter on the other hand is pretty straightforward. Common code can be shared by both. - Currently Python support is disabled for some targets, like Android and iOS. Lua could enable scripting for these environments where having all of Python is overkill or undesirable. Reasons why the answer might be "no": - Are our users going to use this? - Supporting Python is an ongoing pain. Do we really want to risk burdening ourselves with another scripting language? - The Python API is very well tested. We'd need to add test for the Lua bindings as well. It's unlikely this will match the coverage of Python, and probably even undesirable, because what's the point of testing the same thing twice. Also, do we want to risk fragmenting tests across two scripting languages? There's probably a bunch more stuff that I didn't even think of. :-) Personally I lean towards "yes" because I feel the benefits outweigh the costs, but of course that remains to be seen. Please let me know what you think! If you're curious about what this looks like, you can find the patches on my fork on GitHub: https://github.com/JDevlieghere/llvm-project/tree/lua Cheers, Jonas _______________________________________________ lldb-dev mailing list lldb-dev@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
