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Show HN: My C compiler compiled itself

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Re: Show HN: My C compiler compiled itself

#11

Post by __alexander »

yjftsjthsd-h wrote: post #8

> Then run ./build.py. This will use the bootstrapped 30cc-compiler to compile 30cc itself. It then again uses the 30cc-compiled compiler to compile 30cc once again. The final compiler is then stored as ./30cc. Why isn't that also done by the Makefile? The only catch I could see is that you'd need to have it build to different output names, but that seems fine for what it is? --- Also, I'm curious - did you find your…

> Why isn't that also done by the Makefile?

My guess is that some people would rather write Python code than dig into Make’s documentation. That said, ChatGPT is excellent at creating valid make files.

Re: Show HN: My C compiler compiled itself

#12

Post by jheriko »

nice work.

if you want more of a challenge try a compiler compiler that can compile itself... :)

i got pretty far with this myself, although it doesn't work for weirdo languages like Python that need an exceptional lexer. i keep meaning to revisit this problem, since the tools in this space are pretty much non-existent or trash quality.

https://github.com/semiessessi/cp2

Re: Show HN: My C compiler compiled itself

#13

Post by dbcurtis »

yjftsjthsd-h wrote: post #8

> Then run ./build.py. This will use the bootstrapped 30cc-compiler to compile 30cc itself. It then again uses the 30cc-compiled compiler to compile 30cc once again. The final compiler is then stored as ./30cc. Why isn't that also done by the Makefile? The only catch I could see is that you'd need to have it build to different output names, but that seems fine for what it is? --- Also, I'm curious - did you find your…

> Also, I'm curious - did you find yourself having to constrain your use of C in order to make sure that the compiler could compile itself? Or does it implement everything you would use naturally anyways?

That would be the "bootstrapping" process. Nearly a half-century ago I took a compiler lab class where we were given a working, but slightly lame, compiler, and were tasked with adding new, less lame, language features by bootstrapping. That is: 1) implement new feature without using the new feature, 2) using the compiler that results from step 1, re-implement the feature using the new feature, and compile again. 3) Repeat with more features until end of semester for best grade.

Oh, and to the OP, well done!

Re: Show HN: My C compiler compiled itself

#16

Post by anyfoo »

__alexander wrote: post #11
yjftsjthsd-h wrote: post #8

> Then run ./build.py. This will use the bootstrapped 30cc-compiler to compile 30cc itself. It then again uses the 30cc-compiled compiler to compile 30cc once again. The final compiler is then stored as ./30cc. Why isn't that also done by the Makefile? The only catch I could see is that you'd need to have it build to different output names, but that seems fine for what it is? --- Also, I'm curious - did you find your…

> Why isn't that also done by the Makefile? My guess is that some people would rather write Python code than dig into Make’s documentation. That said, ChatGPT is excellent at creating valid make files.

Or just take a few moments to learn the basics about Makefiles.

The thing about Makefiles is that simples ones at least are really easy to write, and read. Much simpler and quicker than a cumbersome python script, that will most likely do less with much more boilerplate code (e.g. dependencies), and be much harder to read.

Of course, you may hit a point where you stretch your Makefile so much beyond its common capabilities that that no longer becomes true, but in my experience that point is pretty far away.

Re: Show HN: My C compiler compiled itself

#17

Post by anyfoo »

jheriko wrote: post #12

nice work. if you want more of a challenge try a compiler compiler that can compile itself... :) i got pretty far with this myself, although it doesn't work for weirdo languages like Python that need an exceptional lexer. i keep meaning to revisit this problem, since the tools in this space are pretty much non-existent or trash quality. https://github.com/semiessessi/cp2

> if you want more of a challenge try a compiler compiler that can compile itself... :)

Is that not what OP did?

Re: Show HN: My C compiler compiled itself

#19

Post by aleph_minus_one »

anyfoo wrote: post #16
__alexander wrote: post #11

Earlier quoted context omitted.

> Why isn't that also done by the Makefile? My guess is that some people would rather write Python code than dig into Make’s documentation. That said, ChatGPT is excellent at creating valid make files.

Or just take a few moments to learn the basics about Makefiles. The thing about Makefiles is that simples ones at least are really easy to write, and read. Much simpler and quicker than a cumbersome python script, that will most likely do less with much more boilerplate code (e.g. dependencies), and be much harder to read. Of course, you may hit a point where you stretch your Makefile so much beyond its common capabi…

> The thing about Makefiles is that simples ones at least are really easy to write, and read. Much simpler and quicker than a cumbersome python script, that will most likely do less with much more boilerplate code (e.g. dependencies), and be much harder to read.

Whether this is true or not depends a lot on from which programming culture/background you come.

Re: Show HN: My C compiler compiled itself

#20

Post by anyfoo »

aleph_minus_one wrote: post #19
anyfoo wrote: post #16

Earlier quoted context omitted.

Or just take a few moments to learn the basics about Makefiles. The thing about Makefiles is that simples ones at least are really easy to write, and read. Much simpler and quicker than a cumbersome python script, that will most likely do less with much more boilerplate code (e.g. dependencies), and be much harder to read. Of course, you may hit a point where you stretch your Makefile so much beyond its common capabi…

> The thing about Makefiles is that simples ones at least are really easy to write, and read. Much simpler and quicker than a cumbersome python script, that will most likely do less with much more boilerplate code (e.g. dependencies), and be much harder to read. Whether this is true or not depends a lot on from which programming culture/background you come.

I honestly don't think so, and I think this is here is a prime example for proving that.

For example, a Makefile that does the same job as the build.py script in this project would be significantly smaller, simpler, and easier to read in several metrics that I'd reasonably call "objective" to a certain degree.

In fact, contrast the Makefile in that project: https://github.com/keyvank/30cc/blob/main/Makefile

With the build.py script: https://github.com/keyvank/30cc/blob/main/build.py

You need to know very little about Makefiles to make immediate sense of what that Makefile is doing, whereas you need to know much more about python to still not immediately see what the build.py script is doing. In fact, you will probably just "guess" that the python script is supposed to do a similar job only from its name before that.

And then the python script still does not do incremental builds at all!

Again, if it gets more complex that can change, but this is far away from that. It takes 10 or so minutes to learn enough about Makefiles to be productive with them, from scratch.

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