On Tue, 25 Mar 2008 21:42:20 -0700
Mike Mattie <codermattie@gmail.com> wrote:

> On Wed, 26 Mar 2008 06:19:17 +0200
> Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > > From: "Balaji V. Iyer" <bviyer@ncsu.edu>
> > > Date: Tue, 25 Mar 2008 09:09:56 -0400
> > > 
> > >     I use the compile option extenstively in emacs. When I type
> > > "M-x compile" the default line is "make -k" Many times I do not
> > > have a make file
> > 
> > You don't need a Makefile to perform simple tasks, because Make
> > knows a lot of built in rules out of the box.  For example, to
> > compile a .c source file foo.c into a program foo, all you need is
> > say "make -k foo", and Make will do it even without a Makefile.
> > 
> > > thus I would lke the default line to be
> > >  
> > > "gcc -ansi -O4 -Wall <c_source_file>"
> > >  
> > > How do I do this?
> > 
> > Customize the variable compile-command.
> > 
> > > I tried the following command but it doesn't seem to work (If
> > > anyone have a better idea please let me know).
> > >  
> > > (function
> > >  (lambda ()
> > >    (unless (or (file-exists-p "makefile")
> > >                (file-exists-p "Makefile"))
> > >      (setq compile-command
> > >            (concat "gcc -Wall -O3 -o"
> > >                    (file-name-sans-extension
> > > (file-name-nondirectory buffer-file -name))
> > >                    " "
> > >                    (file-name-nondirectory buffer-file-name))))))
> > 
> > Where did you put this and how did you use it?
> > 
> > 
> 
> (defun string-join (prefix list)
>   ;; This is analogous to the perl5 join function.
>   ;; given a <prefix> and a <list> of strings join the
>   ;; strings with <prefix> as a seperator between the
>   ;; list values.
>   ;;
>   ;; The result is a single string value.
>   (apply 'concat
>     (car list)
>     (if (cdr list) (prefix-strings prefix (cdr list))) ))
> 
> 
> (setq my-warnings '("-Wall"))
> (setq my-optimization '("-O2"))
> 
> (defun create-compile-command ( target source )
>   (string-join " " (cons
>                      (or (getenv "CC") "gcc")
>                      (append my-warnings my-optimization (list "-o"
> target source)))))
> 
> (create-compile-command "foo" "foo.c")
> 
> (defun my-compile ()
>   (interactive)
>   (lexical-let*
>     ((source    (file-name-nondirectory buffer-file-name))
>      (target    (file-name-sans-extension source)))
> 
>     (if (file-readable-p (concat (file-name-directory
> buffer-file-name) "Makefile")) (compile)
>       (let
>         (compile-command (create-compile-command))
>         (compile))) ))
> 
> I haven't used compile in a while, but this is a sketch of how I
> would approach it. Hope it helps.

as cute as elisp is why not create a generic Makefile, and supply a -f argument ?
 
> Cheers,
> Mike Mattie