Re: Raising Prolog exceptions from C code (2nd attempt)

[Joseph Benden]

Hello,

The Prolog exceptions that I am successfully raising from both C and C++ code is based off of the Emit_Syntax_Error call.

Example:

Emit_Syntax_Error("SQL Error", 1, 1, "Some text that failed or another C call returning a textual error message");

Joseph Benden
Systems Development and Network Administrator
AdWriter, Inc.

Professional Member of the Association of Computing Machinery (www.ACM.org)
Professional Member of the Network and System Professionals Association (www.NaSPA.org)

On Fri, 2002-06-07 at 12:43, Roberto Bagnara wrote:
> Hi there,
>
> I am repeating here a question I have already asked on April 10 and that
> remained unanswered (sorry about that, but I am stuck).
> What is the recommended way to raise a Prolog exception from foreign C code?
> Is it
>
>       Pl_Exec_Continuation(Find_Atom("throw"), 1, &t)
>
> where t is any variable of type PlTerm?
> The manual seems to suggest that, but I would like to know for sure.
> Moreover, even though the simple examples work without problems,
> trying to raise an exception this way from a rather complex C++
> library almost always results in segmentation violations or
> illegal instructions being executed.  And gdb does not seem
> to be of much help debugging that.  Perhaps the Pl_Exec_Continuation
> technique works only under certain circumstances, but which ones?
> Is anybody out there raising exceptions from C++ code?
> Thanks a lot
>
>        Roberto
>
> -- 
> Prof. Roberto Bagnara
> Computer Science Group
> Department of Mathematics, University of Parma, Italy
> http://www.cs.unipr.it/~bagnara/
> mailto:address@hidden
>
>
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