OSDev.org

Hello,

that might not be a totally osdev question but I couldn't find the answer on net.

I want to build a compiler ( gcc ) that just does "compiling" i.e. it takes a ( already preprocessed ) source file and produces assembly code for it. nothing more, no assembling, no objects, no linking, no external libraries, no calling of external programs etc... I read the "building cross gcc" tutorial on wiki but no answer there too... How can I ( or can I ) build gcc without binutils? I will use the gcc only with "-S" option ( produce asm code ) if gcc can't do this, can another open source c++ compiler do it?

Thanks, best regards.

You should have put this is the general programming Forum.
-S in the gcc command line, will make it only output assembly, but I have no idea how to remove preprocessing
Jules

As mentioned, -S. There's no need to remove preprocessing because if you've already preprocessed the file, there will be no preprocessor instructions left in it.

Wrong forum.

ok... May be i couldn't tell exactly what i need... I know about the "-S" option as I mentioned.

My OS currently has a minimal ( almost no ) filesystem support. I simulate standard C files ( stdin and stdout ) to memory, so programs are not able to call and execute an external program like gcc. gcc tries to call "cpp (preprocessor)" "as" and "ld". I want to "build" a gcc that only takes an input from stdin and produces the assembly code to stdout. My question is: how can I configure gcc so that it will not include any code which will try to call an external program. How can I exclude this unneeded part of gcc from build?

For the "wrong forum" thing; can an admin move this thread to the appropriate forum?

Thanks, Best regards.

I very much doubt you would find an off the shelf way to do this, it's not a common thing to want to do. The place to start looking would be the help file to ./configure. If there isn't an option in there (and I doubt there will be), then it's time to go off and start hacking the sources. At that stage, you'd want to pick a simple compiler... GCC isn't the most friendly thing, with all it's backends.

There isn't an off-the-shelf way to do it. You'd have to manually run cc1 and collect2, and who knows what cans of worms that will uncover.

All in all, getting a compiler like GCC to run without the proper runtime support is a losing game. Implement a filesystem.

What's the point of a C compiler if there is no filesystem and no way of running programs from a filesystem? Are you going to actually type a program in and then just hope that there are no mistakes?

200,000 lines of code, the most complex God knows what known to man...
*Power failure*
jules

It's a bit like going back to the times when they used punch cards... just hoping that the huge program you've written all at once works.

If you're targeting i386 or ARM, there's tcc, which includes a C preprocessor, compiler, assembler and linker all in one binary.

Thank you very much... this link ( tinycc ) is very helpful...

Totally wasn't paying attention to this thread, but once reading it, Nwcc comes to mind.

Thank you both both links are really helpful...
Both links are really close to what i want: "compiler that just produces asm code from c,c++ code"

tcc? nwcc? how about pcc or tack?

http://pcc.ludd.ltu.se/
http://tack.sourceforge.net/

Virtually every compiler has a switch that only outputs assembly code. That's how I compile things for my console since I use my own tool for assembling and linking.