Writing a C compiler in 500 lines of Python
1–10 of 183 posts
Re: Writing a C compiler in 500 lines of Python
#2Finally, one can have inefficient C.
Re: Writing a C compiler in 500 lines of Python
#3A time-honored approach!
https://www.blackhat.com/presentations/win-usa-04/bh-win-04-...
(minus directly emitting opcodes, and fitting into 500 lines, of course.)
Re: Writing a C compiler in 500 lines of Python
#4I love the graphic - would go see the worlds largest chomsky
Re: Writing a C compiler in 500 lines of Python
#5Finally, one can have inefficient C.
There's always the CINT interpreter for C and C++.
https://root.cern.ch/root/html534/guides/users-guide/CINT.ht...
Re: Writing a C compiler in 500 lines of Python
#6> Instead, we'll be single-pass: code generation happens during parsing
IIRC, C was specifically designed to allow single-pass compilation, right? I.e. in many languages you don't know what needs to be output without parsing the full AST, but in C, syntax directly implies semantics. I think I remember hearing this was because early computers couldn't necessarily fit the AST for an entire code file in memory at once
Re: Writing a C compiler in 500 lines of Python
#7It is interesting to think that 500 lines of code is something one can write in one or two days. But, writing a C compiler in 500 of comprehensible code (even in python) is challenge in itself that may take months after a few years of solid learning.
I wonder if is this a good path to becoming an extremely productive developer. If some one spends time developing projects like this, but for different areas... A kernel, a compressor, renderer, multimedia/network stack, IA/ML... Will that turn a good dev into a 0.1 Bellard?
Re: Writing a C compiler in 500 lines of Python
#8I made similar project in TypeScript[1]. Basically multipass compiler that generates x86 assembly, compiles it to binary and runs it. The worst thing were register allocator, designing IR code and assembler.
Re: Writing a C compiler in 500 lines of Python
#9Is there a C compiler written in Python that aims for maximum readability rather than trying to get as much done under X lines of code?
Re: Writing a C compiler in 500 lines of Python
#10> Instead, we'll be single-pass: code generation happens during parsing IIRC, C was specifically designed to allow single-pass compilation, right? I.e. in many languages you don't know what needs to be output without parsing the full AST, but in C, syntax directly implies semantics. I think I remember hearing this was because early computers couldn't necessarily fit the AST for an entire code file in memory at once
Linked from another thread: http://cm.bell-labs.co/who/dmr/chist.html
It explains the memory limits and what happened :)
> After the TMG version of B was working, Thompson rewrote B in itself (a bootstrapping step). During development, he continually struggled against memory limitations: each language addition inflated the compiler so it could barely fit, but each rewrite taking advantage of the feature reduced its size. For example, B introduced generalized assignment operators, using x=+y to add y to x. The notation came from Algol 68 [Wijngaarden 75] via McIlroy, who had incorporated it into his version of TMG. (In B and early C, the operator was spelled =+ instead of += ; this mistake, repaired in 1976, was induced by a seductively easy way of handling the first form in B's lexical analyzer.)