Re: Interfaces.C.Strings.Value(Chars_Ptr,Length)

Re: Interfaces.C.Strings.Value(Chars_Ptr,Length)

[Ted Dennison]

Jan Kroken wrote:

> I have a
>
> struct x {
>         char *dptr;
>         int   dsize;
> }
> in C which I have imported into Ada with

...

>         return c.strings.value(d.dptr,
>                                c.size_t(d.dsize));
> But the only thing it does is to raise an interfaces.c.terminator_error.

The problem is that the Interfaces.C.Strings.Value routine works by
searching through the string until it reaches a terminator. The structure
you list above was clearly designed to not require a terminator. Thus it
would not be shocking if the C routine that filled it in did not terminate
the string.

The problm you have is the definition of C.Strings.Value. It is supposed to
be equivalent to C.To_Ada(C.Strings.Value(d.dptr, c.size_t(d.dsize),
Trim_Nul=>True). But the definition of C.To_Ada says that if Trim_Nul is
true and there is no Nul to trim, it will raise Terminator_Error.

To get around the problem, try doing a C.To_Ada(C.Strings.Value(d.dptr,
c.size_t(d.dsize), Trim_Nul=>False).

--
T.E.D.

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