A micro-manual for Lisp implemented in C

nakkaya.com

78 pointspapaf6 comments

Open articleView on HN

Cool article, but his interpreter is broken.

Both repl mode and file mode just spew errors.

gcc version 4.1.2

[briang@ ~]$ gcc lisp.c -o lisp

[briang@ ~]$ ./lisp test.lisp

> Error.

...

It worked fine for me:

$ gcc --version

i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5664)

...

$ gcc lisp.c -o lisp

$ ./lisp test.lisp

> A

> (A B C)

...

Tried clang trunk and ICC 11.0, both give me the same result I originally posted.

I supposed it could be some weird difference between OSX vs Linux.

Verified. Worked fine on my Macbook (i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5493)), broke on a Linux box (gcc (GCC) 4.1.2 20070626 (Red Hat 4.1.2-14)).

This will drive me crazy.

Edit: it has to do with 32-bit and 64-bit. When I compile explicitly as 32 bit on Linux (which is a 64-bit machine), the error goes away. Probably related to how he casts everything to an object, and assumes things will be in certain places.

It's this: http://nakkaya.com/2010/08/24/a-micro-manual-for-lisp-implem...

I suspect Red Hat's gcc is aligning structure members on 64-bit boundaries.

Excellent! I thought name looked suspect.

Reply on news.ycombinator.com