Tcl Source Code

 * Forwarded methods have the following extra information.
 */

typedef struct ForwardMethod {
    Tcl_Obj *prefixObj;		/* The list of values to use to replace the
				 * object and method name with. Will be a
				 * non-empty list. */
    int fullyQualified;		/* If 1, the command name is fully qualified
				 * and we should let the default Tcl mechanism
				 * handle the command lookup because it is
				 * more efficient. If 0, we need to do a
				 * specialized lookup based on the current
				 * object's namespace. */
} ForwardMethod;

/*
 * Helper definitions that declare a "list" array. The two varieties are
 * either optimized for simplicity (in the case that the whole array is
 * typically assigned at once) or efficiency (in the case that the array is
 * expected to be expanded over time). These lists are designed to be iterated

	Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_FORWARD", NULL);
	return NULL;
    }

    fmPtr = ckalloc(sizeof(ForwardMethod));
    fmPtr->prefixObj = prefixObj;
    Tcl_ListObjIndex(interp, prefixObj, 0, &cmdObj);
    fmPtr->fullyQualified = (strncmp(TclGetString(cmdObj), "::", 2) == 0);
    Tcl_IncrRefCount(prefixObj);
    return (Method *) Tcl_NewInstanceMethod(interp, (Tcl_Object) oPtr,
	    nameObj, flags, &fwdMethodType, fmPtr);
}

/*
 * ----------------------------------------------------------------------

	Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_FORWARD", NULL);
	return NULL;
    }

    fmPtr = ckalloc(sizeof(ForwardMethod));
    fmPtr->prefixObj = prefixObj;
    Tcl_ListObjIndex(interp, prefixObj, 0, &cmdObj);
    fmPtr->fullyQualified = (strncmp(TclGetString(cmdObj), "::", 2) == 0);
    Tcl_IncrRefCount(prefixObj);
    return (Method *) Tcl_NewMethod(interp, (Tcl_Class) clsPtr, nameObj,
	    flags, &fwdMethodType, fmPtr);
}

/*
 * ----------------------------------------------------------------------

    int objc,			/* Number of arguments. */
    Tcl_Obj *const *objv)	/* Arguments as actually seen. */
{
    CallContext *contextPtr = (CallContext *) context;
    ForwardMethod *fmPtr = clientData;
    Tcl_Obj **argObjs, **prefixObjs;
    int numPrefixes, len, skip = contextPtr->skip;
    Command *cmdPtr;

    /*
     * Build the real list of arguments to use. Note that we know that the
     * prefixObj field of the ForwardMethod structure holds a reference to a
     * non-empty list, so there's a whole class of failures ("not a list") we
     * can ignore here.
     */

    Tcl_ListObjGetElements(NULL, fmPtr->prefixObj, &numPrefixes, &prefixObjs);
    argObjs = InitEnsembleRewrite(interp, objc, objv, skip,
	    numPrefixes, prefixObjs, &len);

    if (fmPtr->fullyQualified) {
	cmdPtr = NULL;
    } else {
	cmdPtr = (Command *) Tcl_FindCommand(interp, TclGetString(argObjs[0]),
		contextPtr->oPtr->namespacePtr, 0 /* normal lookup */);
    }
    Tcl_NRAddCallback(interp, FinalizeForwardCall, argObjs, NULL, NULL, NULL);
    ((Interp *)interp)->lookupNsPtr
	    = (Namespace *) contextPtr->oPtr->namespacePtr;
    return TclNREvalObjv(interp, len, argObjs, TCL_EVAL_INVOKE, cmdPtr);
}

static int
FinalizeForwardCall(
    ClientData data[],
    Tcl_Interp *interp,
    int result)

    ClientData clientData,
    ClientData *newClientData)
{
    ForwardMethod *fmPtr = clientData;
    ForwardMethod *fm2Ptr = ckalloc(sizeof(ForwardMethod));

    fm2Ptr->prefixObj = fmPtr->prefixObj;
    fm2Ptr->fullyQualified = fmPtr->fullyQualified;
    Tcl_IncrRefCount(fm2Ptr->prefixObj);
    *newClientData = fm2Ptr;
    return TCL_OK;
}

/*
 * ----------------------------------------------------------------------