Re: Bug when compiling elc code?

[Sven Joachim <svenjoac@gmx.de>]

[Please keep this topic on-list. Thanks.]

Hadron <hadronquark@googlemail.com> writes:

> The problem is that even if personal.elc exists in 600 mode, then a
> recompile puts it back to 644. This is surely a bug?

Maybe, but other compilers (gcc, for instant) behave similarly: they
remove the target before they write to it.  And Emacs has a good
reason to do this, as can be seen from this comment in the
byte-compile-file function in bytecomp.el:

,----
| 		  (when (file-exists-p target-file)
| 		    ;; Remove the target before writing it, so that any
| 		    ;; hard-links continue to point to the old file (this makes
| 		    ;; it possible for installed files to share disk space with
| 		    ;; the build tree, without causing problems when emacs-lisp
| 		    ;; files in the build tree are recompiled).
| 		    (delete-file target-file))
| 		  (write-region (point-min) (point-max) target-file))
`----

Regards,
        Sven