This is a weird bug that is not localized to even DJGPP.  All recent versions
of CPP (C preprocessor) for every operating system and CPU have this problem.

Problem:
This assembly code does not assemble:
#define asdf $1

    mov asdf,%eax

But this does:
    mov $1,%eax

The command line I'm using is gcc -fassemble-with-cpp asdf.s -o asdf.o and it's
not working.  It gives the error "operands don't match any known 386
instruction."

cpp asdf.s displays this:
# something or other
<blank>
<blank>
    mov $1 ,%eax
          ^
The space is the problem.  As this bug applies to all versions of GCC it should
be reported to the maintainers of the UNIX version.

-- Barubary

I just figured out that the case of the S matters...

gcc -fassemble-with-cpp asdf.S -o asdf.o

works, but

gcc -fassemble-with-cpp asdf.s -o asdf.o

does not.  This should be fixed by having a CPP parameter that forces "assembly
parsing" mode and having -fassemble-with-cpp make GCC call CPP with that
parameter.

-- Barubary

That gcc command line is about 100% wrong.

To start with, there is no '-fassemble-with-cpp' flag. The flag you're
wanting to pass is

	-x assembler-with-cpp

That's what has the exact same effect as calling the file .S instead of
.s

So, in the essence: no bug here, just incorrect use.