SectorC: 512바이트 C 컴파일러 (2023)

Thanks! Macroexpanded:

SectorC: A C Compiler in 512 bytes - https://news.ycombinator.com/item?id=36064971 - May 2023 (80 comments)

why? and why "quickly?

I think the same. Really nice project and good trick with hashing tokens.

PS. There left 21 bytes (21 * 0x00 - from 0x01e0 to 0x01fd). Maybe something can be packed there ;)

I actually "shipped" a parser using the symbols' hash(as the only identifier) for a test tool once. Hopefully, the users never used enough symbols to collide 32-bits.

I've had the idea before. Was never quite brave enough to do it. It's elegant until it isn't....

This is very nice. I'm currently writing a minimalist C compiler although my goal isn't fitting in a boot sector, it's more targeted at 8-bit systems with a lot more room than that.

This is a great demonstration of how simple the bare bones of C are, which I think is one reason I and many others find it so appealing despite how Spartan it is. C really evolved from B which was a demake of Fortran, if Ken Thompson is to be trusted.

Would and how much would it shrink when if, while, and for were replaced by the simple goto routine? (after all, in assembly there is only jmp and no other fancy jump instruction (I assume) ).

And PS, it's "chose your own adventure". :-) I love minimalism.

An interesting use case - for the compiler as-is or for the essentiall idea of barely-C - might be in bootstrapping chains, i.e. starting from tiny platform-specific binaries one could verify the disassembly of, and gradually building more complex tools, interpreters, and compiler, so that eventually you get to something like a version of GCC and can then build an entire OS distribution.

Examples:

https://github.com/cosinusoidally/mishmashvm/

and https://github.com/cosinusoidally/tcc_bootstrap_alt/

They're saying the naive implementation was more than 150 lines of C code (300-450 bytes), i.e. too big.

It's a fun comparison, but with the notable difference that that one can compile the Linux kernel and generate code for multiple different architectures, while this one can only compile a small proportion of valid C. It's a great project, but it's not so much a C compiler, as a compiler for a subset of C that allows all programs this compiler can compile to also be compiled by an actual C compiler, but not vice versa.

> when programming was actually fun and showed off your skills

Oh no. Now more people are able to do what I do. I'm not special anymore.

Er, what? The article describes a compiler for a not-quite-C programming language which fits entirely in 512B. Your project, if I see this correctly, can optionally produce code meant to execute as boot sector.

Both interesting projects, but other than the words 'boot sector', 'C' and 'compiler', I don't see a similarity.

you bootstrap it into a library you can include optionally, duh

Weren't structs a fairly late addition to C?

And anyway, isn't that kind of missing the point. 512 bytes isn't much. Your comment is nearly a 5th of that budget.

Too real! LMAO

"you don't have -wTokenHashCollision enabled! it's your own foolish ignorance that triggered UB; the spec is perfectly clear!"

Further Fun fact, that submission was called OTCC. I reverse engineered it and that provided inspiration for SectorC.

https://xorvoid.com/otcc_deobfuscated.html https://github.com/xorvoid/otcc_deobfuscated

Meh, I did an entire awk interpreter in two lines:

  #!/bin/sh
  echo "awk: bailing out" >&2

That would be true of one using a libc, but in a boot sector, you only have the bios, so the atoi being referenced is the one defined in c near the beginning of the article

This kind of comment reminds me of how broad "software development" is.

On other HN posts, they're stating something like "software development is dead", "LLM as a compiler", "Do you read compiled assembly?", and so on.

While some other posts like this contain huge mechanical sympathy and literally r/w the assembly directly.