Re: Some problems in `add-log-current-defun'

[Masatake YAMATO <jet@gyve.org>]

About II. I'd like to hear a comment from David.

> I. The end of a function
> 
> The point is moved to the start position of a function or an empty
> line (lines consist of only white space characters) with the following
> code.
> 
>     ;; See if we are in the beginning part of a function,
>     ;; before the open brace.  If so, advance forward.
>     (while (not (looking-at "{\\|\\(\\s *$\\)"))
>       (forward-line 1))
> 
> But this is not reliable.  If someone forgets to put a newline after a
> function, `add-log-current-defun' will report wrong name.  Please
> consider the following example:
> 
>     int
>     f1 ()
>     {
>       /* If point is here `add-log-current-defun' gets wrong result.  */
>     }
>     int
>     f2 ()
>     {
>       /* ...  */
>     }
> 
> When the point is inside the body of `f1', invoking
> `add-log-current-defun' will get `f2', rather than `f1'.

Reproduced. I think this is case that `add-log-current-defun' cannot handle
reasonably formatted C++ code.

> III. Different styles
> 
> The function skips typedefs and arglist with the following forms.
> 
>         ;; Skip back over typedefs and arglist.
>         ;; Stop at the function definition itself
>         ;; or at the line that follows end of function doc string.
>         (forward-line -1)
>         (while (and (not (bobp))
>                     (looking-at "[ \t\n]")
>                     (not (looking-back "[*]/)\n" (- (point) 4))))
>           (forward-line -1))
> 
> This is not general: it cannot process programs in some style.  In
> section 7.7 of the 3rd edition of The C++ Programming Language by
> Bjarne Stroustrup, there is a shell sort implementation:
> 
>     void ssort(void * base, size_t n, size_t sz, CFT cmp)
>     /*
>         Sort the "n" elements of vector "base" into increasing order
>         using the comparison function pointed to by "cmp".
>         The elements are of size "sz".
> 
>         Shell sort (Knuth, Vol3, pg84)
>     */
>     {
>         /* ...  */
>     }
> 
> The current implementation cannot handle programs in this style
> correctly.

The book is very famous. However, in my experience this code is not
reasonably formatted. 

> And what I tried to fix is not general too.  My fix is
> 
>     (while (not (looking-back "\\(^\\|[ \t]\\)"))
>       (forward-sexp -1))
> 
> This is not general too: C++ permits the nested name to be put in many
> lines.  For example, the following name is valid:
> 
>     void
>     class_1
>     ::
>     sub_class_2
>     ::
>     method_3 ()
>     {
>       /* ...  */
>     }
> 
> The current implementation cannot handle this name correctly.

I think this is also not reasonably formatted.

Masatake YAMATO