Is 6c expected to "just work" like gcc on Linux?

[arnoldrobbins]

Hi. I'd like to understand the goals. Is the idea that after doing . env.sh so that 6c is in my path I can then build normal Linux software?

I tried this with GNU awk (gawk), and because of the additional binaries in the bin, I could not even run configure. So I tried running configure normally and then running make CC=6c but I got nowhere.

I then tried compiling a standalone program:

$ cat /tmp/hello.c 
#include <stdio.h>

int main(void)
{
	printf("hello, world!\n");
	return 0;
}
$ 6c /tmp/hello.c -o /tmp/hello
/tmp/hello.c:2 6c: No such file or directory: stdio.h

Am I doing something wrong, or are things just not quite fully baked? Thanks.

[aryx]

No, 6c/5c/... are not like gcc. They come from Plan 9 and the Plan 9 designers (who were also the creators of Unix and creators of C) decided to also rethink the C library so they don't use anymore stdio.h, unistd.h, etc. They use libc.h (see demos/hello.c).

That being said, some of the Plan 9 folks also defined APE, the ANSI/Posix environment to provide a backward-compatibility layer, see include/APE/, but it's not enabled by default, so you have to use special flags.

I'll try to add monday a demos/hello_ape.c (or hello_posix.c) showing how to use it. But APE will not be enough for some programs. I managed to compile as is certain Unix/Linux programs but it's not always the case.

[arnoldrobbins]

Thanks. FWIW, I've known about Plan 9 and what you describe for well over 30 years. :-)

If your goals are to compile/cross-compile Plan 9 programs for Linux/MacOS/Windows, that's fine. I just wanted to understand what to expect.

FYI, I maintain GNU awk, so I'm always looking for additional C compilers that I can "drop in" for testing.

In any case, you've done impressive work. Much thanks.

P.S. If you happen to know of a version of ken-cc that will (a) build out of the box on Linux and (b) can be used as a drop-in replacement for GCC, I'd like to hear about it. Thanks.

[aryx]

Yes maybe I should clarify things in the README. The main goal is indeed to be able to cross compile Plan 9 from Linux/MacOS/Windows, mainly to support my other principia softwarica project. But another goal is to slightly compete with gcc and clang to provide an alternative cross compiling toolchains for many architectures. For instance I want to compile the Xv6 teaching OS also with goken, and I also hope (via APE) to be able to compile some regular Unix programs (for example I've used it to compile the OCaml bytecode interpreter, which is a 10 000 LOC C programs where APE was enough). I might try to compile GNU awk using goken/APE but it's almost a non-goal to support GNU programs that often use very complex ifdefs. Actually goken ships with the pcc small program which is a frontend to the 5c/6c/... that internally calls a real C preprocessor because the cpp embeded inside 5c/6c/ has limited ifdef support for example.

You can look at the typesetting/ directory in goken which contains a few programs that are using APE because they are old UNIX programs that were not migrated to the Plan 9 API back in the days.

[aryx]

I'll check how much work it would be to be used as a drop-in replacement ... that's an interesting exercise. I'll try on gawk.

[arnoldrobbins]

Clarifying the README would help. Let me know how your experiment goes. Good luck, and thanks!