[Geany-devel] Function Definition

Colomban Wendling lists.ban at xxxxx
Wed Apr 14 17:56:45 UTC 2010

Hi Jordan,

jordan a écrit :
> I'm trying to write a plug-in that among other things adds a function
> header.    Unfortunately this is also my first C program so it has been
> more of  a learning experience then anything, but I'm finally at the
> point where it sort of works.
What does your plugin, apart adding a function header? I'm curious.
And hum, I'm working on something similar to this part: a "generic"
documentation generator [1].

> Currently my plug-in reads the current line and
> breaks it down, however it's my understanding that some C programmers
> may break a function definition over several lines, in which case my
> plug-in would not work properly.
Yes. Many programmers (I'm of these) breaks function definition in
multiple line, actually I do something like this:

function_name (type arg1,
               type arg2,

…and of course it is a little harder to naively parse (not so much in
facts, but doesn't allow what you do).

> I would also like to make it so the
> function definition for whatever the current function is would be used.
> So this brings me to my questions, is there an easy way to determine if
> the current position in the editor is part of a function or not?  If so
> is there an easy way to get the function definition?  If not could
> someone maybe point me to some tutorials about parsing text in c.
As Enzo said, there is the scope to determine if a particular line is
part of a function or not, but its is not supported by every tag
generator used by Geany. What I personally chose was to walk the tag
list and find the tag closest to the current line. Tweaking this way a
bit gives quite good results.

And for the function definition, see the tag list, there is everything
you probably want (or almost). One missing thing is the argument list –
I personally chose to fix this with a regular expression, but there
might be better solutions; for example if hard-coded things are
acceptable, a custom argument parser is a somewhat easy task.

> Also currently the header that is generated by my plug-in c style multi
> line hard coded, and I was wondering if at some time more of the methods
> in templates.c would be opened up to the API? 
I don't know exactly your goals, but Geany's templates are not complete.
if I'm right: they are very simple, which is good, but doesn't support
things like loops and so (as far as I know, tell me if I'm wrong).
Since I didn't find any template parser in C, I written my own [2] for
the needs of the plugin I write. It is heavily more complex, but OTOH
more powerful… choice is not easy, is it? :D If you're interested, feel
free to use it.


[1] no it's not dead, you'll see soon (for those who understand ^^)
[2] http://ctpl.tuxfamily.org/ ; but if you're interested, wait for the
upcoming 0.2 release that will be somewhat different in its API. It's
almost ready and can be found in the git master.

More information about the Devel mailing list