From: Simon Strandgaard <0bz63fz3m1qt3001@...>
Date: 2003-07-24T00:05:52+09:00
Subject: Re: Embedding problem - SEGV

On Thu, 24 Jul 2003 00:49:04 +0900, Brian Candler wrote:

> On Wed, Jul 23, 2003 at 10:58:55PM +0900, Brian Candler wrote:
>> If I still want a regular Ruby exception report printed, after catching it,
>> is there a function I can call?

I don't know if this can be useful to you ?
http://metaeditor.sourceforge.net/embed/#id2841406
 
[snip] 
> It looks like I'm going to have to split all these functions into two: one
> to do the Ruby work, and one to call it using rb_protect (and pass a struct*
> between the two if there's more than one argument), purely to prevent the
> coredumps. This is pretty nasty. Before now, it was looking that back-ruby
> was going to be much cleaner than back-perl :-(

You could do like this C++ code:

/* ------------------------------
wrap rb_funcall
------------------------------ */
struct Arguments {
    VALUE recv;
    ID id;
    int n;
    VALUE *argv;
    Arguments(VALUE recv, ID id, int n, VALUE *argv) :
        recv(recv), id(id), n(n), argv(argv) {
    }
};

VALUE FuncallWrap(VALUE arg) {
    Arguments &a = *reinterpret_cast<Arguments*>(arg);
    return rb_funcall2(a.recv, a.id, a.n, a.argv);
}

/*
purpose:
call a ruby function in a safe way.
translate ruby errors into c++ exceptions.


VALUE Unsafe() {
    return rb_funcall(
        self,
        rb_intern("test"),
        1,
        INT2NUM(42)
    );
}

VALUE Safe() {
    return RUBY_CPP::Funcall(
        self,
        rb_intern("test"),
        1,
        INT2NUM(42)
    );
}
*/
VALUE Funcall(VALUE recv, ID id, int n, ...) {
    VALUE *argv = 0;

    if (n > 0) {
        argv = ALLOCA_N(VALUE, n);
        va_list ar;
        va_start(ar, n);
        int i;
        for(i=0;i<n;i++) {
            argv[i] = va_arg(ar, VALUE);
        }
        va_end(ar);
    }

    Arguments arg(recv, id, n, argv);
    int error = 0;
    VALUE result = rb_protect(FuncallWrap, reinterpret_cast<VALUE>(&arg), &error);
    if(error)
        throw RubyError::Create("cannot invoke ruby-function");
    return result;
}


--
Simon Strandgaard