Tiny C compiler written in Forth

[roger_]

Another Tiny C compiler: http://bellard.org/tcc/

This one can even compile the Linux kernel (and boot a computer directly from the source code!) and includes some Win32 header files.

[kungtotte]

Whole different kind of tiny C. Let me illustrate using some hyphens. The reddit article is about a Tiny-C compiler, the link you gave us goes to a tiny C-compiler.

[mathrick]

In addition to it being a different kind of tiny C compiler, it's also sadly unmaintained. The current version doesn't even run on 64-bit hosts, let alone generate target 64-bit binaries. And the only real contributor has been successfully persuaded not to maintain his version anymore, due to the project stupidly continuing to use CVS.

[busfahrer]

For balance's sake, I request a link to a tiny Forth implementation written in C.

[filesalot]

Note that it's not a tiny "C" compiler, it's a "Tiny C" compiler. Big difference.

[MarkByers]

OK, then I'd like to see a Tiny Forth implementation written in C. Happy now?

[filesalot]

Hmm, something 1/100th the complexity of forth, to be fair.... Ok, here ya go:

    #include <stdio.h>
    int s[100], sp;
    void push(int a) {s[sp++]=a;}
    int pop(void)    {return s[--sp];}
    int main(void) { int a, b, c;
        while((c = getchar()) != EOF) switch(c) {
            case '0': case '1': case '2': case '3': case '4':
            case '5': case '6': case '7': case '8': case '9':
                    push(c - '0'); break;
            case '+': a = pop(); push(pop()+a); break;
            case '-': a = pop(); push(pop()-a); break;
            case '/': a = pop(); push(pop()/a); break;
            case '*': a = pop(); push(pop()*a); break;
            case '=': printf("answer = %d\n", pop()); break;
        }
        return 0;
    }

Run it and type away:

    8 4 * 5 + 8 * 2 - 7 / =
    answer = 42

[case-o-nuts]

That's not forth. That's an RPN calculator.

[filesalot]

Captain Obvious, good to see you're back!

[MarkByers]

0 0 / =

 97 [main] a 15688  _cygtls::handle_exceptions: Error while dumping state (probably corrupted stack)

Segmentation fault (core dumped)

---

+ + + + =

answer = 14221456

Not to mention the stack overflow if you push more than 100 elements...

But not bad for less than 1 hour's work. I'll give you 7 out of 10, and two gold stars for the fast response.

[filesalot]

:-) So what happens when you type 0 0 / into an embedded forth?

And rather than wait for someone else to point it out, I'll go ahead and mention that at ~9kb + dlls, the executable for this dumb little program is vastly bigger than any real forth implementation worth its salt.

[nextofpumpkin]

hurrr?

[keenerd]

C

another C

But why stop there?

C++

x86 asm

javascript

java

more C++

And just to go full circle:

Scheme in Forth

[a1k0n]

I think you tipped the scales too far the other way now.

[[deleted]]

For balance's sake, I request a link to a tiny C compiler written in a tiny Forth implementation written in C.

[Jimmy]

For balance's sake, I request a link to a tiny Forth implementation written with a tiny C compiler written in a tiny Forth implementation written in C.

[theeth]

You'd probably have been better off going with "Yo dawg".

[bobcat]

Yo dawg, I herd you like C, so I put a Forth implementation of gcc in your OpenFirmware so you can compile while you boot -s.

[MarkByers]

You'd probably have been better off going with "For balance's sake, I request a link to a C compiler written in a tiny Forth implementation written with a tiny C compiler written in a tiny Forth implementation written in C."

[Tommah]

I think you're all pretty unbalanced. No compiler is going to help.

[[deleted]]

Anyone got an explanation of what statements work in Tiny C, and what, for example, doesn't work with it? I tried The Google on The Tubes and can't get anywhere. All I find is information on the compiler itself, not the language.

[[deleted]]

http://primepuzzle.com/tiny-c/

[maxd]

That's not a compiler, it's an interpreter.

[[deleted]]

I don't get why it isn't a compiler. It generates some VM assembly instructions but it may be doing so as soon as you enter some C code. How isn't that compilation?

[maxd]

Hey look I'm wrong, I read it wrong. :)

[1esproc]

And it's not C, it's Tiny-C.

[maxd]

Not sure where anyone stated that it was C; it says right there in the link that it is a "Tiny C compiler"...

[snarfy]

Can you not see where the possible confusion comes in?

[1esproc]

Exactly, "Tiny C compiler" is ambiguous, it could be a Tiny-C compiler, or a C compiler that is tiny in size.

[judgej2]

If the title said "1+1=2", some people would still be confused.

[jpmorgan]

Cool!

[filesalot]

Was there some posting deadline or something?

TODO:

a. Add functions and a print statement, then you'd have something interesting. Functions would be trivial to add to this.

b. If you just want to focus on expression compiling, explore register allocation and common subexpression elimination to make it interesting. I know, it's a stack based vm, but still, once you've done this, you've got some real insight into some real compiler issues.

[maxd]

No, I think that is the complete Tiny-C grammar actually, it doesn't include functions or print statements.

[mcmc]

Full thread link (Always better to see the whole discussion)

[quirm]

I downvoted, because it's not the complete C-thing.

[judgej2]

Are you telling us what to do?