Show HN: A compiler for a small language into x86-64 assembly (opens in new tab)

Nothing wrong with semi-colons. Everyone has a different preference anyway.

Thanks for saying all that. It was a huge amount of work and getting appreciation makes it all worth it!

No hard constraints as of now. But I don't think I want to include meta programming or a pre-processor (don't really like it to be honest). I do want to keep it compatible with C internally, on Assembly level. One thought is, to create a file with function headers/definitions that are then dynamically linked and can just be used.

I used some C std library functions that way for debugging (printf, ...). And as I follow the standard calling conventions, the compiler should automatically generate compatible code.

With this, it would also be possible, to write OpenGL code. That would be really awesome :)

As of usage of my language - Not sure yet. Up until now, the road was more of the goal then the finished language.

Thanks :) That's where I was trying to get to. I did some smaller performance comparisons against C (with -O0), where I was at about 90% speed. But there is a lot of performance to gain, if I optimize the resulting assembly. There are lots of cases where I push and pop directly afterwards because of the general expression code generation (no real knowledge of broader context). So I expect that to help a lot regarding performance. Also things like jump tables for simple switches are on the table.

Yes, I thought about going for LLVM or another representation but decided to do it once myself (no given performance optimizations or the like) with room for improvement.

:) I (now) agree. In fact, each part isn't even really that hard. It's mostly just a lot to work. And then code generation. I had some headaches with multiple return values and keeping the calling conventions intact... And then with structs as well.

That language flow and general simplicity was one of my most important goals. Thanks for noticing :)

No, I had no problems regarding that. What you mention ('+', '(') are all part of simple expressions when parsing. And I strictly parse right recursive and re-order the expressions later (for operator priority). So that was not an issue. Most of these problems I solved, by making my parser a lookahead of >1. In a few cases, there is a lookahead of 3 to determine what exactly should be parsed.

I guess anything, that can run an X86-64 Elf executable? ;) Although there is still a lot missing, for it to be taken serious. Starting with strings, files, input, ... But thats for another time or whenever I need it, I guess.

That is really motivating, thank you for saying that!

Those are some of my currently open tabs :) Lots of Google use on top of that. The parser is actually quite straight forward. The much harder part (for me) was the code generation afterwards (No experience with Assembly so far).

- General compiler design - This was one of the main ressources. https://www.tutorialspoint.com/compiler_design/compiler_desi...

- https://www.lua.org/manual/5.3/manual.html#9

- https://www.godbolt.org/

- Linux system call table: http://blog.rchapman.org/posts/Linux_System_Call_Table_for_x...

- A bit on floating point: https://cs.fit.edu/~mmahoney/cse3101/float.html

- Assembly https://www.cs.yale.edu/flint/cs421/papers/x86-asm/asm.html

- More assembly: https://www.complang.tuwien.ac.at/ubvl/amd64/amd64h.html

It's a bit of pain to implement in some cases, but worth it :)

Let me know, if you have questions or need hints where to find some relevant details in my code.

You both should try "Compiler Construction: Principles and Practice" [0]. Theory is interleaved with substantial examples and exercises. You create an entire compiler for a tiny language called TINY (hah.) You write it in C and generate code for a portable virtual machine -- the book also goes into detail on the VM, with source code.

Lastly, the book's appendix has guidance for writing a compiler for a subset of the C language.

[0] https://www.cs.sjsu.edu/~louden/cmptext/