Re: What definition generates the SWIG upcasts in wrappers and what controls it?

You've somehow got SWIG to believe that Handle_Geom_Geometry is a base
class of Handle_Geom_Curve but this can't be valid (as per the compiler's
error message). Given that these seem to be typedefs to a handle template,
I suspect they are smart pointers and Geom_Geometry is actually a base of
Geom_Curve. I suggest using SWIG's shared_ptr support to provide something
similar. See https://github.com/swig/swig/blob/v4.0.2/Lib/shared_ptr.i, in
particular the info at the top of that file:

// This is a helper file for shared_ptr and should not be included directly.

// The main implementation detail in using this smart pointer of a type is
to customise the code generated
// to use a pointer to the smart pointer of the type, rather than the usual
pointer to the underlying type.
// So for some type T, shared_ptr<T> * is used rather than T *.

// Another key part of the implementation is the smartptr feature:
//   %feature("smartptr") T { shared_ptr<T> }
// This feature marks the class T as having a smartptr to it (the
shared_ptr<T> type). This is then used to
// support smart pointers and inheritance. Say class D derives from base B,
then shared_ptr<D> is marked
// with a fake inheritance from shared_ptr<B> in the type system if the
"smartptr" feature is used on both
// B and D. This is to emulate the conversion of shared_ptr<D> to
shared_ptr<B> in the target language.

William

On Sat, 25 Dec 2021 at 11:45, [email protected] <
[email protected]> wrote:

>
> I'm trying to fix OpenCascade SWIG interface.
>
> A bunch of C  wrapper functions like this:
>
> SWIGEXPORT jlong JNICALL
> Java_org_jcae_opencascade_jni_OccJavaJNI_Handle_1Geom_1Curve_1SWIGUpcast(JNIEnv
> *jenv, jclass jcls, jlong jarg1) {
>     jlong baseptr = 0;
>     (void)jenv;
>     (void)jcls;
>     *(Handle_Geom_Geometry **)&baseptr = *(Handle_Geom_Curve **)&jarg1;
>     return baseptr;
> }
> cause errors like this:
>
> /Users/nyholku/jCAE/occjava3/src-java/org/jcae/opencascade/jni/OccJavaJAVA_wrap.cxx:7849:42:
> error: incompatible pointer types assigning to 'Handle_Geom_Geometry *'
> (aka 'handle<Geom_Geometry> *') from 'Handle_Geom_Curve *' (aka
> 'handle<Geom_Curve> *')
>     *(Handle_Geom_Geometry **)&baseptr = *(Handle_Geom_Curve **)&jarg1;
>
> on the otherhand many wrappers like this:
>
> SWIGEXPORT jlong JNICALL
> Java_org_jcae_opencascade_jni_OccJavaJNI_TopoDS_1Vertex_1SWIGUpcast(JNIEnv
> *jenv, jclass jcls, jlong jarg1) {
>     jlong baseptr = 0;
>     (void)jenv;
>     (void)jcls;
>     *(TopoDS_Shape **)&baseptr = *(TopoDS_Vertex **)&jarg1;
>     return baseptr;
> }
>
> compile without a problem.
>
> I've tried to see what is the difference in the .i files for  TopoDS /
> Vertex compared to Geom / Surface but can't figure it out.
>
> What control how those SWIGupcasts are generated?
>
> wbr Kusti
>
>
>
>
> _______________________________________________
> Swig-user mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/swig-user
>

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