ImportC Rox

[Don Allen]

On Tuesday, 21 March 2023 at 22:56:07 UTC, Bowler Hat wrote:
> On Saturday, 12 November 2022 at 15:35:03 UTC, Don Allen wrote:
>> On Wednesday, 9 November 2022 at 15:00:39 UTC, Don Allen wrote:
>>> On Monday, 7 November 2022 at 22:05:38 UTC, Walter Bright 
>>> wrote:
>>>> https://news.ycombinator.com/item?id=33509223
>>>
>>
>> Once I came to that realization, I created a gtk.c file in a 
>> place visible to my source files containing just one line:
>> ```
>> #include <gtk/gtk.h>
>> ```
>> and then arranged for the clang pre-processor to produce a 
>> gtk.i file from it, using the standard pkg-conf method to tell 
>> Clang where all the gtk header-file directories are. The 
>> 'import gtk's in my D source files now see the gtk.i file and 
>> so I am now actually using ImportC, rather than imagining it. 
>> The problem is that it produces many errors, due to the 
>> expansion of gtk.h generating a lot of C that ImportC doesn't 
>> understand.
>>
>> I tried modifying my gtk.c in an attempt to work around some 
>> of the problems, using #defines, a technique suggested in 
>> Walter's documentation. This helped, but ultimately, it just 
>> kicks the can down the road. The fundamental problem is that 
>> the expansion of gtk.h is extremely complex and, crucially, 
>> makes use of gcc and/or clang extensions that I could not work 
>> around; they are just too far from C11 or too difficult to 
>> modify. So to continue to use D, I will have to revert to my 
>> original method for dealing with gtk.
>
> Hi Don,
>
> I've looked at this thread for a while now and made several 
> attempts at getting it to work. Unfortunately, my experience 
> with ImportC follows exactly what you describe.
>
> I'm actually more curious about the details of how you 
> originally worked with gtk in D. I've tried the same method 
> with some success but its not entirely obvious how you deal 
> with certain cases. For example, g_signal_connect is actually a 
> macro for calling another function with specific parameters. 
> That seems to have no direct equivalent in D.

See the message I posted earlier in this thread (on 11/09/2022). 
It describes my general approach to using gtk3 from D without 
ImportC.

As to g_signal_connect -- yes, it's a C macro and you can't use 
it directly in D. But there are signal-connecting functions in 
gtk3, e.g., g_signal_connect_data, that you can use instead. See 
the gtk documentation. The signal-connecting functions live in 
gobject, so you'll need to go to that section of the 
documentation.