CC in /etc/make.conf and headers in ${WORLDTMP}

[Ian Lepore]

On Wed, 2013-02-27 at 16:02 +0100, deeptech71 wrote:
> Recently, I've posted several build errors that only I seemed to run into. The errors were based on "incompatible/missing declarations". The bottom line of those is actually the following, as I gather:
> 
> I, without any compilers in /usr/bin, was trying to build the world and kernel by setting CC to basically /home/me/my_compilers/bin/clang.
> 
> As the handbook says, the FreeBSD build system uses the compiler in /usr/obj, ie., the one "just built for further purposes". As I can see, that compiler is specifically crafted to use the include files in ${WORLDTMP}, ie., in /usr/obj/usr/src/tmp/usr/include (not /usr/include), where "new" headers are placed in an early phase of the build process. This is required for when the source tree has been "significantly" changed since the last installworld -- the new code won't build with the headers in /usr/include. In such cases, of course compilation breaks when an unaware compiler (eg., /usr/bin/cc, /home/me/my_compilers/bin/clang, etc.) is used.
> 
> I was able to compile the world and kernel by changing CC from /home/me/my_compilers/bin/clang to /usr/obj/usr/src/tmp/usr/bin/cc upon the first compilation error, by which time the latter compiler was available.
> 
> However, after a successful build and install, and no following update of the source tree, an external compiler can be used, because by then, the new headers will have been installed in /usr/include.
> 
> So it appears that specifying an external compiler as CC in /etc/make.conf is not supposed to work in general. Life sux. Is there any intention to remedy this?
> _______________________________________________
> freebsd-current at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe at freebsd.org"

It appears that you may be just slightly ahead of the curve.  You'll
probably be interested in this:

http://lists.freebsd.org/pipermail/freebsd-arch/2013-February/014055.html

-- Ian