Re: [Vala] Incorrect C generated with union containing anonymous struct

[Jan-Jaap van der Geer <jjvdgeer inbox com>]

Evan Nemerson <evan coeus-group com> wrote:

> On Thu, 2011-10-13 at 00:10 +0200, Jan-Jaap van der Geer wrote:
> > (Excuses if this appears twice, but after waiting half an hour my
> > first attempt still hasn't appeared...)

> > I have the following struct:

> > typedef union foobar foobar;

> > union foobar
> >    {  struct
> >       {  char *bar;
> >       }
> >       foo;
> >    };

> > This is represented in the vapi like this:

> > [CCode (cheader_filename = "struct.h")]
> > namespace StructTest
> > {
> >   [CCode (cname = "foo")]
> >   public struct Foo
> >   {
> >     [CCode (cname = "bar")]
> >     public unowned string bar;
> >   }

> >   [CCode (cname = "foobar")]
> >   public struct Foobar
> >   {
> >     [CCode (cname = "foo")]
> >     public unowned Foo foo;
> >   }
> > }

> There are basically two ways to do this... what you usually see
> in vapis is something like this:

> public struct Foobar {
>   [CCode (cname = "foo.bar")]
>   public unowned string foo_bar;
> }

Right! I should have thought of that!

> The other option, which I haven't tested in a while but used to
> work well enough, is something like:

> [CCode (cname = "struct { char *bar; }")]
> public struct Foo {
>   public unowned string bar;
> }

> public struct Foobar {
>   public Foo foo;
> }

As the struct I really am using is a lot more complicated than the
above simplification, I don't think I'll go for this one. It does
have the advantage of keeping the structure though, that is nice.

> > Is this a bug? Is there a workaround? Note that the C-code is
> > beyond my control, so workarounds involving changing the
> > definition of the struct in C will most probably not work...

> No, it's not a bug. The fact that it used to work was a bit of a
> fluke... there are situations where it never did (such as
> assigning Foobar.foo to a variable).

Hm, good point.

Thanks for the explanation! (As well to Luca Bruno!)

Cheers,
Jan-Jaap