Re: C++ Indentation and access-labels

["Marc Dürner" <marc.duerner@googlemail.com>]

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Hello,

Thank you, Alan. This works much better now. Can you help me out with a few
remaining problems?

1) The inline-methods in a class or struct are not indented to the same
level as topmost-intro

Here is an example how it looks like:

class c
{
    friend class y;

    public:
        c()
        : _n(8)
    { } <=== here

        void meth()
    {} <=== here

    private:
        int _n;
};

2) when I type 'void meth()' after typing ')' eight spaces (two levels of
indentation) are added to the next line with the cursor positioned at the
beginning of the line:

class c
{
    public:
        void method()
X.......

where X is the cursor position and . are trailing whitespace. The same
happens when I close a inline-defun with '}'. When I continue it disappears,
but it is a bit uncomfortable if I would just add a method to a class. Also,
the trailing whitespace stays when I reindent a block with the tab key

3) Another problem is caused by macros before class names. This is something
which is very common:

class MY_API MyClass
{};

MY_API is some macro which expands to compiler specific attributes like
declspec (VC) or __attribute__ (GCC). Many libraries have macros like this.
Somehow it confuses the parser and indentation of access-labels is only two
spaces (half of what it should be, c-basic-offset is 4).Example:

class MY_API c
{
    friend class y;

  public:
    c()
        : _n(8)
    { }

    void meth()
    {}

  private:
    int _n;
};

Maybe there is another way to tell the parser to simply ignore "MY_API".

regards,
Marc

2009/9/25 Alan Mackenzie <acm@muc.de>

> Hi, Marc!
>
> On Mon, Sep 21, 2009 at 04:08:30PM +0200, Marc Dürner wrote:
>
> > > # File ~/duerner.el:
> > >
> #########################################################################
> > > (defsubst md-at-inclass/topmost-intro (sintax)
> > >  (and
> > >   (eq (caar sintax) 'inclass)
> > >   (eq (car (cadr sintax)) 'topmost-intro)))
>
> > > (defun md-ind-prot-class ()
> > >  "Give an extra level of indentation to class thingies under an access
> > > specifier, e.g.:
>
> > >    public
> > >        A();        <========== extra level of indentation.
>
> > > This should really be properly implemented in CC Mode, but it's not."
> > >  (and
> > >   (md-at-inclass/topmost-intro c-syntactic-context)
> > >   (let (m-type)
> > >     (when
> > >         (save-excursion
> > >           (back-to-indentation)
> > >           ;; Go back one "statement" at a time till we reach a label or
> > > something
> > >           ;; which isn't an inclass/topmost-intro
> > >           (while
> > >               (and (eq (setq m-type (c-beginning-of-statement-1))
> > > 'previous)
> > >                    (md-at-inclass/topmost-intro
> (c-guess-basic-syntax))))
> > >           ;; Have we found "private:", "public": or "protected"?
> > >           (and (eq m-type 'label)
> > >                (looking-at
> > >                 (eval-when-compile
> > >                  (c-make-keywords-re nil (c-lang-const
> c-protection-kwds
> > > c++))))))
> > >       (save-excursion
> > >        (back-to-indentation)
> > >        (c-shift-line-indentation c-basic-offset))))))
>
> > > (defun md-add-hook ()
> > >  (add-hook 'c-special-indent-hook 'md-ind-prot-class))
> > > (add-hook 'c++-mode-hook 'md-add-hook)
> > >
> #########################################################################
>
> > > The above is a fairly rough and ready hack.  If it does something
> silly,
> > > please get back to me with a description of the failure.
>
>
> > Thank you for you help!
>
> > The script you wrote seems to have no effect (yet):
>
> Sorry.  I hadn't tested things enough.  Here's what the problem is:
>
> > Here is what I added to my .emacs:
>
> > (require 'cc-mode)
> > (setq c-basic-offset 4)
> > (setq-default c-tab-always-indent nil)
>
> Just an aside: (setq c-basic-offset 4) will set the global value, but
> this will get overridden by the style system.  Either create your own
> style. or set this to c++-mode-hook (see below).  Yes, it's
> overcomplicated.  ;-(
>
> > (add-hook 'c++-mode-hook
> >           '(lambda ()
> >              (c-set-style "ellemtel")
> >              (c-set-offset 'access-label '0)))
>
> The form (c-set-style "ellemtel") in c++-mode-hook wipes clean the
> value of c-special-indent-hook.  :-(  So we need to arrange to do
> "ellemtel" before doing "special-indent".
>
> > (eval-after-load "cc-mode" '(load-file "~/duerner.el"))
>
> So, please change the following:
> (i) in ~/duerner.el, REMOVE the last line, "(add-hook 'c++-mode-hook
>  'md-add-hook)".
>
> (ii) in ~/duerner.el, insert at the top the line "(require 'cc-langs)",
>  to make sure it compiles properly.
>
> (ii) Change your .emacs bit to this:
>
>  (require 'cc-mode)
>  ;; (setq c-basic-offset 4)  ; <===== commented out
>   (setq-default c-tab-always-indent nil)
>
>  (add-hook 'c++-mode-hook
>            '(lambda ()
>               (c-set-style "ellemtel")
>                (add-hook 'c-special-indent-hook 'md-ind-prot-class) ;
> <======
>                (c-set-offset 'access-label '0)
>                (setq c-basic-offset 4)))
>
>  (eval-after-load "cc-mode" '(load-file "~/duerner.el"))
>
> Hope it works now!
>
> > regards,
> > Marc
>
> --
> Alan Mackenzie (Nürnberg).
>

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