How to become an expert in compilers the long way?

[allevato (Tony Allevato)]

@Slava_Pestov

One thing I've found is that textbooks about compilers heavily focus on parsing and optimization, but discussion of type checking is often rather minimal and the other areas are barely mentioned at all. It would be nice if someone wrote a "modern compiler frontend design" book that skipped parsing and code generation and did a deep dive on everything in between instead!

This. Going from a compilers textbook to a project like LLVM/Clang/Swift is like building a paper airplane and then working on A320s. Nothing in my undergraduate or graduate compilers courses really prepared me for anything more than toy work. (Those courses predated Clang, so I hope modern courses try to do it a little better, but 15 weeks isn't nearly enough time.)

Compared to similar projects of size and scope, the LLVM and Swift projects are some of the cleanest, better-documented ones that I've experienced. Grab a debugger, sprinkle some breakpoints around, explore, and just start calling the dump() method on literally everything. There's a ton of useful information baked in there to figure out what's going on, and you'll probably be productive faster than you initially expected.