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Newsgroups: comp.lang.ada
Date: Mon, 17 Sep 2018 16:06:31 -0700 (PDT)
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Subject: Re: Interface To C Struct That Includes An Array
From: Roger <rogermcm2@gmail.com>
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Xref: reader02.eternal-september.org comp.lang.ada:54352
Date: 2018-09-17T16:06:31-07:00
List-Id: <comp.lang.ada>

On Tuesday, September 18, 2018 at 1:24:09 AM UTC+10, Lucretia wrote:
> On Monday, 17 September 2018 13:01:43 UTC+1, rog...@iinet.net.au  wrote:
> > I'm having problems interfacing the following record to C.
> > 
> >    type API_String is record
> >       Length  : Interfaces.C.size_t := 0;
> >       Data    : API_String_Data_Array := (others => Interfaces.C.char'Val (0));
> >    end record;
> >    pragma Convention (C_Pass_By_Copy, API_String);
> 
> Variable length things in Ada are problematic no matter what really.
> 
> What does the type definition of API_String_Data_Array look like? Is it also Convention => C?

I've replaced API_String_Data_Array with its original declaration which was
subtype API_String_Data_Array is char_array (0 .. Max_Length - 1):= (others => Interfaces.C.char'Val (0));


  --  This declaration has been checked OK for Key data. DON'T CHANGE
   type API_String is record
      Length  : Interfaces.C.size_t := 0;
      Data     : char_array (0 .. Max_Length - 1):= (others => Interfaces.C.char'Val (0));
   end record;
   pragma Convention (C_Pass_By_Copy, API_String);

but the same problem remains