Re: kbuild-2.5

Re: kbuild-2.5

[David Howells]

> David Howells <dhowells@redhat.com> wrote:
> >Will kbuild get Makefiles in each subdirectory that allow 
> >it to build just the things in that subdirectory tree?
> 
> Documentation/kbuild/kbuild-2.5.txt, KBUILD TARGETS.

Okay... for users of emacs, here's an elisp function that looks to see if it's
in a subdirectory of a kernel tree (and if so whether it's kbuild or
traditional), and if so invents an appropriate command line for compiling just
in that subdir:-) Otherwise it just falls back to the usual compile function.

This can be put in a .emacs file, and can bound to a key:

	(global-set-key [f5] 'kernel-compile)

David


(defun kernel-compile ()
  "Attempt to compile the current directory as if it's part of a kernel tree,
otherwise default to normal compile."
  (interactive)
  (let ((buffile (buffer-file-name))
	(bufbits)
	(curdir)
	(topdir)
	(subdir)
	(slasher)
	(cmdline)
	(pos))
    (if (not buffile)
	;; no buffer file name
	(progn
	  (setq cmdline (read-from-minibuffer "Compile command: "
					      compile-command nil nil
					      '(compile-history . 1)))
	  (compile cmdline)
	  )
      ;; got a buffer filename, split into directory name chunks
      (progn
	(setq bufbits (split-string (buffer-file-name) "/"))

	;; create a function to interpose slash characters between all the
	;; elements of a string list, but not to add leading of trailing
	;; slashes
	(setq slasher
	      (lambda (lst slasher)
		(if (not (cdr lst))
		    lst
		  (append (list (concat (car lst) "/"))
			  (apply slasher (list (cdr lst) slasher))
			  ))))

	;; iteratively work up the directory tree from the current directory
	;; looking for various marker files
	(setq topdir nil)
	(setq pos (length bufbits))
	(while (and (> pos 1) (not topdir))
	  (setq pos (- pos 1))
	  (setq curdir (subseq bufbits 0 pos))
	  (setq curdir (apply slasher (list curdir slasher)))
	  (setq curdir (eval (append '(concat) (list "/") curdir)))
	  (if (and
	       (file-readable-p (concat curdir "/COPYING"))
	       (file-readable-p (concat curdir "/CREDITS"))
	       (file-readable-p (concat curdir "/README"))
	       (file-readable-p (concat curdir "/MAINTAINERS"))
	       (file-readable-p (concat curdir "/Makefile"))
	       (file-readable-p (concat curdir "/kernel/sched.c"))
	       )
	      (setq topdir curdir)
	      )
	  )

	(if topdir
	    ;; deal with the markers being found
	    (progn
	      (if (not (file-symlink-p (concat curdir "/include/asm")))
		  (error "The %s/include/asm symlink appears to be missing"
			 topdir))

	      (setq subdir (subseq bufbits pos(- (length bufbits) 1)))
	      (setq subdir (apply slasher (list subdir slasher)))
	      (setq subdir (eval (append '(concat) subdir)))

	      ;; determine whether using kbuild or not
	      (if (file-readable-p (concat curdir "/scripts/shadow.pl"))
		  ;; kbuild
		  (setq cmdline (concat "make -C " topdir " " subdir))
		;; traditional
		(setq cmdline (concat "make -C " topdir " SUBDIRS=" subdir))
		)
	      (setq cmdline (read-from-minibuffer "Kernel compile: "
						  cmdline nil nil
						  '(compile-history . 1)))
	      (compile cmdline)
	      )

	  ;; deal with the markers not being found
	  (setq cmdline (read-from-minibuffer "Compile command: "
					      compile-command nil nil
					      '(compile-history . 1)))
	  (compile cmdline)
	  )

	))
    )
  )

Re: kbuild-2.5

[Keith Owens]

On Thu, 01 Nov 2001 11:19:02 +0000, 
David Howells <dhowells@redhat.com> wrote:
>Okay... for users of emacs, here's an elisp function that looks to see if it's
>in a subdirectory of a kernel tree (and if so whether it's kbuild or
>traditional), and if so invents an appropriate command line for compiling just
>in that subdir:-) Otherwise it just falls back to the usual compile function.
>(defun kernel-compile ()
>....
>	  (if (and
>	       (file-readable-p (concat curdir "/COPYING"))

Won't work with separate source and object trees in kbuild 2.5.

  export KBUILD_SRCTREE_000=/build/kaos/2.4.13-kbuild-2.5
  export KBUILD_OBJTREE=/build/kaos/object-2.4.13
  cd /anywhere/you/like
  make -f $KBUILD_SRCTREE_000/Makefile-2.5

If you define the kbuild tree variables then you can be in any
directory when you issue the make command.  If you are using shadow
trees then you can be in a sparse source tree which only contains of
the files.

>	      ;; determine whether using kbuild or not
>	      (if (file-readable-p (concat curdir "/scripts/shadow.pl"))

grep CONFIG_KBUILD_2_5 .config is better, you can still build using
kbuild 2.4 even after applying the 2.5 patch.  The presence of a kbuild
2.5 file is not definitive.  Of course the .config is in $KBUILD_OBJTREE
which might not be the current directory.