Date: Wed, 30 Dec 2009 08:17:52 +0100 From: Oliver Mahmoudi <olivermahmoudi@gmail.com> To: "freebsd-questions@FreeBSD.org" <freebsd-questions@freebsd.org> Subject: how does the C pre-processor interface with make? Message-ID: <6b4b2d2c0912292317h7c4d9bbfo196dcf48396e0afa@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hey folks,
I was wondering how the C pre-processor interfaces with make. Let's suppose
that I have a little C program, something along the lines of:
#include <stdio.h>
int
main()
{
#ifdef FOO
fprintf(stdout, "Hi, my name is foo.\n");
#endif
#ifdef BAR
fprintf(stdout, "Hi, my name is bar.\n");
#endif
fprintf(stdout, "I am always here.\n");
return(1-1);
}
It is easy to control the pre-processor in the above code by defining the
respective terms or leaving them out, however,
I am trying to control the conditionals from out of a makefile.
This is essentially the way in which the kernel sources are compiled.
Any suggestions?
Thanks
Oliver
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6b4b2d2c0912292317h7c4d9bbfo196dcf48396e0afa>