LLVM IR parser?

[atirut-w]

I want to make a compiler to compile LLVM IR to 6502 assembly and I have no idea how to implement IR's grammar using pyparsing

[ptmcg]

Can you post a link to the grammar you would want to implement?

[atirut-w]

https://llvm.org/docs/LangRef.html

[ptmcg]

Ha, very good! The Google took me there also, but that has lots of descriptive notes with just bits of syntax definitions throughout. So it isn't easy to see where to start.

Googling for "llvm ir bnf", I found this file in GitHub: https://github.com/llir/grammar/blob/master/ll.tm

From this, I would take some small sample bits of LLVM IR source, and then use the BNF to implement in pyparsing the relevant expressions to parse those sample bits. Then add more complexity and features over time.

Given that that BNF is 5000+ lines long, this is not going to be a short project. As I recall, I spent about 8 weeks implementing the Verilog parser, and this is more massive. But an interesting-sounding project.

[ptmcg]

Not meaning to scare you off. I expect you could carve off a useful subset of the grammar and implement that in a few days to a couple of weeks.

[atirut-w]

Going to take it slowly. I could probably get a very bare-bones IR of an empty function working in a day or two.