Re: Non byte-aligned components in GNAT rejected

["Marc A. Criley" <mcq95@earthlink.net>]

Peter Richtmyer wrote:
> 
> Using Gnat 3.15p I had the same error you did.
> I found a work-around that might be acceptable to you:
> 
> package NBA is
> 
>    type VMF_Character is new Character range
>      Character'Val(0) .. Character'Val(127);
>    for VMF_Character'Size use 7;
> 
>    type Unit_Name_Type is array (1..64) of VMF_Character;
>    for Unit_Name_Type'Component_Size use 7;
>    for Unit_Name_Type'Size use 448;
> 
>    type un_t is                          -- new
>       record                             -- new
>          un : Unit_Name_Type;            -- new
>       end record;                        -- new
>    -- for un_t'size use 448;             -- bad results!
> 
>    type Unit_Group_Type is record
>       B : Boolean;
>       -- Unit_Name : Unit_Name_Type;     -- deleted
>       Unit_Name : un_t;                  -- new
>    end record;
>    for Unit_Group_Type use record
>       B      at 0 range 0 .. 0;
>       Unit_Name at 0 range 1 .. 448; -- This is OK now
>    end record;
> 
> end NBA;
> 
> As you can see, the Unit_Name is still one variable,
> using th same type definition, but is now a record
> within the record.

I compiled this with GNAT 3.15p on Win2K and 3.13p on Linux and still
got an error, albeit a different one:  "nba.ads:21:07: fields of "un_t"
must start at storage unit boundary".  Line 21 is the "Unit_Name :
un_t;" line.  What GNAT/OS did you use?

Marc