X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=ldk-java;a=blobdiff_plain;f=gen_type_mapping.py;h=4d013c68b34a7ce8f861c2844075a542a84587c9;hp=81bb0f99b8ebcaa5236073fa627514c8d224a212;hb=HEAD;hpb=0d48e557e83ef085cc92c2de63b9c81c061ce78c

diff --git a/gen_type_mapping.py b/gen_type_mapping.py
index 81bb0f99..ba77c087 100644
--- a/gen_type_mapping.py
+++ b/gen_type_mapping.py
@@ -43,44 +43,56 @@ class TypeMappingGenerator:
             else:
                 arr_name = "ret"
                 arr_len = ret_arr_len
-            if ty_info.c_ty == "int8_tArray":
+            if ty_info.c_ty == "int8_tArray" or ty_info.c_ty == "int16_tArray":
                 (set_pfx, set_sfx) = self.consts.set_native_arr_contents(arr_name + "_arr", arr_len, ty_info)
-                ret_conv = ("int8_tArray " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_len, ty_info) + ";\n" + set_pfx, "")
+                ret_conv = (ty_info.c_ty + " " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_len, ty_info) + ";\n" + set_pfx, "")
                 arg_conv_cleanup = None
                 if not arr_len.isdigit():
                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
                     arg_conv = arg_conv + arr_name + "_ref." + arr_len + " = " +  self.consts.get_native_arr_len_call[0] + arr_name + self.consts.get_native_arr_len_call[1] + ";\n"
-                    if (not ty_info.is_ptr or not holds_ref) and ty_info.rust_obj != "LDKu8slice":
+                    if (not ty_info.is_ptr or not holds_ref) and (ty_info.rust_obj != "LDKu8slice" and ty_info.rust_obj != "LDKu16slice"):
                         arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = MALLOC(" + arr_name + "_ref." + arr_len + ", \"" + ty_info.rust_obj + " Bytes\");\n"
                         arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_ref." + ty_info.arr_access, arr_name + "_ref." + arr_len, ty_info, True) + ";"
                     else:
                         arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = " + self.consts.get_native_arr_contents(arr_name, "NO_DEST", arr_name + "_ref." + arr_len, ty_info, False) + ";"
                         arg_conv_cleanup = self.consts.cleanup_native_arr_ref_contents(arr_name, arr_name + "_ref." + ty_info.arr_access, arr_name + "_ref." + arr_len, ty_info)
-                    if ty_info.rust_obj == "LDKTransaction":
+                    if ty_info.rust_obj == "LDKTransaction" or ty_info.rust_obj == "LDKWitness":
                         arg_conv = arg_conv + "\n" + arr_name + "_ref.data_is_owned = " + str(holds_ref).lower() + ";"
                     ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
-                    ret_conv = (ret_conv[0], ";\nint8_tArray " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_name + "_var." + arr_len, ty_info) + ";\n")
+                    ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_name + "_var." + arr_len, ty_info) + ";\n")
                     (pfx, sfx) = self.consts.set_native_arr_contents(arr_name + "_arr", arr_name + "_var." + arr_len, ty_info)
                     ret_conv = (ret_conv[0], ret_conv[1] + pfx + arr_name + "_var." + ty_info.arr_access + sfx + ";")
-                    if not holds_ref and ty_info.rust_obj != "LDKu8slice":
+                    if not holds_ref and (ty_info.rust_obj != "LDKu8slice" and ty_info.rust_obj != "LDKu16slice"):
                         ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
+                    from_hu_conv = self.consts.primitive_arr_from_hu(ty_info, None, arr_name)
+                    to_hu_conv = self.consts.primitive_arr_to_hu(ty_info, None, arr_name, arr_name + "_conv")
                 elif ty_info.rust_obj is not None:
                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
                     arg_conv = arg_conv + "CHECK(" + self.consts.get_native_arr_len_call[0] + arr_name + self.consts.get_native_arr_len_call[1] + " == " + arr_len + ");\n"
                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_ref." + ty_info.arr_access, arr_len, ty_info, True) + ";"
                     ret_conv = (ret_conv[0], "." + ty_info.arr_access + set_sfx + ";")
+                    from_hu_conv = self.consts.primitive_arr_from_hu(ty_info, arr_len, arr_name)
+                    to_hu_conv = self.consts.primitive_arr_to_hu(ty_info, None, arr_name, arr_name + "_conv")
                 else:
-                    arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n"
+                    # Note that we just blindly assume we should be using unsigned integers here.
+                    arg_conv = "u" + ty_info.subty.c_ty + " " + arr_name + "_arr[" + arr_len + "];\n"
                     arg_conv = arg_conv + "CHECK(" + self.consts.get_native_arr_len_call[0] + arr_name + self.consts.get_native_arr_len_call[1] + " == " + arr_len + ");\n"
                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_arr", arr_len, ty_info, True) + ";\n"
-                    arg_conv = arg_conv + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
+                    arg_conv = arg_conv + "u" + ty_info.subty.c_ty + " (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
                     ret_conv = (ret_conv[0] + "*", set_sfx + ";")
+                    from_hu_conv = self.consts.primitive_arr_from_hu(ty_info, arr_len, arr_name)
+                    to_hu_conv = self.consts.primitive_arr_to_hu(ty_info, None, arr_name, arr_name + "_conv")
+                to_hu_conv_name = None
+                if to_hu_conv is not None:
+                    to_hu_conv_name = arr_name + "_conv"
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = arg_conv, arg_conv_name = arr_name + "_ref", arg_conv_cleanup = arg_conv_cleanup,
-                    ret_conv = ret_conv, ret_conv_name = arr_name + "_arr", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+                    ret_conv = ret_conv, ret_conv_name = arr_name + "_arr",
+                    to_hu_conv = to_hu_conv, to_hu_conv_name = to_hu_conv_name,
+                    from_hu_conv = from_hu_conv)
             else:
                 assert not arr_len.isdigit() # fixed length arrays not implemented
-                assert ty_info.java_ty[len(ty_info.java_ty) - 2:] == "[]"
+                assert ty_info.java_hu_ty[len(ty_info.java_hu_ty) - 2:] == "[]"
                 if arr_name == "":
                     arr_name = "ret"
                 conv_name = arr_name + "_conv_" + str(len(ty_info.java_hu_ty))
@@ -176,37 +188,52 @@ class TypeMappingGenerator:
                     if is_nullable:
                         ret_conv = (ret_conv[0], ret_conv[1] + "\n}")
 
-                to_hu_conv = None
-                to_hu_conv_name = None
                 if subty.to_hu_conv is not None:
-                    base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
-                    to_hu_conv = ty_info.java_hu_ty + " " + conv_name + "_arr = new " + base_ty + "[" + arr_name + ".length]"
-                    if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
-                        # Do a bit of a dance to move any excess [] to the end
-                        to_hu_conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
-                    to_hu_conv += ";\nfor (int " + idxc + " = 0; " + idxc + " < " + arr_name + ".length; " + idxc + "++) {\n"
-                    to_hu_conv += "\t" + subty.java_ty + " " + conv_name + " = " + arr_name + "[" + idxc + "];\n"
-                    to_hu_conv += "\t" + subty.to_hu_conv.replace("\n", "\n\t") + "\n"
-                    to_hu_conv += "\t" + conv_name + "_arr[" + idxc + "] = " + subty.to_hu_conv_name + ";\n}"
+                    to_hu_conv = self.consts.var_decl_statement(self.consts.c_type_map["uint32_t"][0], conv_name + "_len", self.consts.get_java_arr_len(arr_name)) + ";\n"
+                    to_hu_conv += self.consts.var_decl_statement(ty_info.java_hu_ty, conv_name + "_arr", self.consts.constr_hu_array(ty_info, conv_name + "_len"))
+                    to_hu_conv += ";\n"
+                    pfx = ""
+                    if is_nullable:
+                        to_hu_conv += "if (" + arr_name + " != null) {\n"
+                        pfx = "\t"
+                    to_hu_conv += pfx + self.consts.for_n_in_range(idxc, "0", conv_name + "_len") + "\n"
+
+                    to_hu_conv += pfx + "\t" + self.consts.var_decl_statement(subty.java_ty, conv_name, self.consts.get_java_arr_elem(subty, arr_name, idxc)) + ";\n"
+                    to_hu_conv += pfx + "\t" + subty.to_hu_conv.replace("\n", "\n\t" + pfx) + "\n"
+                    to_hu_conv += pfx + "\t" + conv_name + "_arr[" + idxc + "] = " + subty.to_hu_conv_name + ";\n"
+                    to_hu_conv += pfx + "}"
+                    if is_nullable:
+                        to_hu_conv += "\n}"
+                    cleanup = self.consts.cleanup_converted_native_array(ty_info, arr_name)
+                    if cleanup is not None:
+                        to_hu_conv += "\n" + cleanup
                     to_hu_conv_name = conv_name + "_arr"
-                from_hu_conv = None
+                else:
+                    to_hu_conv = self.consts.primitive_arr_to_hu(ty_info, None, arr_name, arr_name + "_conv")
+                    if to_hu_conv is not None:
+                        to_hu_conv_name = arr_name + "_conv"
+                    else:
+                        to_hu_conv_name = None
+                from_hu_conv = self.consts.primitive_arr_from_hu(ty_info, None, arr_name)
                 if subty.from_hu_conv is not None:
                     hu_conv_b = ""
                     if subty.from_hu_conv[1] != "":
-                        hu_conv_b = "for (" + subty.java_hu_ty + " " + conv_name + ": " + arr_name + ") { " + subty.from_hu_conv[1] + "; }"
-                    if subty.java_ty == "long" and subty.java_hu_ty != "long":
-                        from_hu_conv = (arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray() : null",
-                            hu_conv_b)
-                    elif subty.java_ty == "long":
-                        from_hu_conv = (arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray() : null", "/* TODO 2 " + subty.java_hu_ty + "  */")
+                        iterator = self.consts.for_n_in_arr(conv_name, arr_name, subty)
+                        if is_nullable:
+                            hu_conv_b = "if (" + arr_name + " != null) { " + iterator[0] + subty.from_hu_conv[1] + ";" + iterator[1] + " }"
+                        else:
+                            hu_conv_b = iterator[0] + subty.from_hu_conv[1] + ";" + iterator[1]
+                    if from_hu_conv is not None:
+                        arr_conv = self.consts.primitive_arr_from_hu(ty_info, None, self.consts.map_hu_array_elems(arr_name, conv_name, ty_info, subty, is_nullable))
+                        assert arr_conv[1] == ""
+                        from_hu_conv = (arr_conv[0], hu_conv_b)
                     else:
-                        from_hu_conv = (arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray(" + ty_info.java_ty + "::new) : null",
-                            hu_conv_b)
+                        from_hu_conv = (self.consts.map_hu_array_elems(arr_name, conv_name, ty_info, subty, is_nullable), hu_conv_b)
 
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = arg_conv_cleanup,
                     ret_conv = ret_conv, ret_conv_name = arr_name + "_arr", to_hu_conv = to_hu_conv, to_hu_conv_name = to_hu_conv_name, from_hu_conv = from_hu_conv)
-        elif ty_info.java_ty == "String":
+        elif ty_info.java_fn_ty_arg == "Ljava/lang/String;":
             assert not is_nullable
             if not is_free:
                 arg_conv = "LDKStr " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_c_call(ty_info.var_name) + ";"
@@ -215,6 +242,7 @@ class TypeMappingGenerator:
                 arg_conv = "LDKStr dummy = { .chars = NULL, .len = 0, .chars_is_owned = false };"
                 arg_conv_name = "dummy"
             if ty_info.arr_access is None:
+                assert False
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
                     ret_conv = ("const char* " + ty_info.var_name + "_str = ",
@@ -225,17 +253,23 @@ class TypeMappingGenerator:
                 free_str = ""
                 if not holds_ref:
                     free_str = "\nStr_free(" + ty_info.var_name + "_str);"
+                to_hu_conv = self.consts.str_to_hu_conv(ty_info.var_name)
+                to_hu_conv_name = None
+                if to_hu_conv is not None:
+                    to_hu_conv_name = ty_info.var_name + "_conv"
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
                     ret_conv = ("LDKStr " + ty_info.var_name + "_str = ",
                         ";\njstring " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_native_call(ty_info.var_name + "_str." + ty_info.arr_access, ty_info.var_name + "_str." + ty_info.arr_len) + ";" + free_str),
-                    ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+                    ret_conv_name = ty_info.var_name + "_conv",
+                    to_hu_conv=to_hu_conv, to_hu_conv_name=to_hu_conv_name,
+                    from_hu_conv = self.consts.str_from_hu_conv(ty_info.var_name))
         elif ty_info.var_name == "" and not print_void:
             # We don't have a parameter name, and want one, just call it arg
             if not ty_info.is_native_primitive:
                 assert(not is_free or ty_info.rust_obj not in self.opaque_structs)
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
+                    arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)untag_ptr(arg);\nFREE(untag_ptr(arg));",
                     arg_conv_name = "arg_conv", arg_conv_cleanup = None,
                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 7", to_hu_conv_name = None, from_hu_conv = None)
             else:
@@ -243,30 +277,43 @@ class TypeMappingGenerator:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = None, arg_conv_name = "arg", arg_conv_cleanup = None,
                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 8", to_hu_conv_name = None, from_hu_conv = None)
-        elif ty_info.is_native_primitive:
+        elif ty_info.is_native_primitive and ty_info.c_ty != "void":
             assert not is_nullable
             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None,
-                ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+                arg_conv = None, arg_conv_name =  ty_info.var_name, arg_conv_cleanup = None,
+                ret_conv = (ty_info.c_ty + " " + ty_info.var_name + "_conv = ", ";"), ret_conv_name = ty_info.var_name + "_conv",
+                to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+        elif ty_info.c_ty == "void":
+            assert ty_info.is_native_primitive
+            assert not is_nullable
+            return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                arg_conv = None, arg_conv_name =  ty_info.var_name, arg_conv_cleanup = None,
+                ret_conv = None, ret_conv_name = ty_info.var_name,
+                to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
         else:
             if ty_info.var_name == "":
                 ty_info.var_name = "ret"
 
             if ty_info.rust_obj in self.opaque_structs:
-                from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr & ~1", "this.ptrs_to.add(" + ty_info.var_name + ")")
+                from_hu_conv = (ty_info.var_name + " == null ? " + self.consts.native_zero_ptr + " : " + self.consts.get_ptr(ty_info.var_name), self.consts.add_ref("this", ty_info.var_name))
                 opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
-                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
-                if ty_info.is_ptr and holds_ref:
-                    opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = false;"
-                else:
-                    opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = untag_ptr(" + ty_info.var_name + ");\n"
+                opaque_arg_conv += ty_info.var_name + "_conv.is_owned = ptr_is_owned(" + ty_info.var_name + ");\n"
+                opaque_arg_conv += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_conv);"
+
                 if not is_free and (not ty_info.is_ptr or not holds_ref or ty_info.requires_clone == True) and ty_info.requires_clone != False:
                     if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
                         # TODO: This is a bit too naive, even with the checks above, we really need to know if rust wants a ref or not, not just if its pass as a ptr.
-                        opaque_arg_conv = opaque_arg_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
-                        from_hu_conv = (from_hu_conv[0], "")
+                        # arg_conv is used when converting a function argument from java normally (with holds_ref set),
+                        # and when converting a java value being returned from a trait method (with holds_ref unset).
+                        # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
+                        # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
+                        if holds_ref:
+                            opaque_arg_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
+                        else:
+                            from_hu_conv = (ty_info.var_name + " == null ? " + self.consts.native_zero_ptr + " : " + ty_info.var_name + ".clone_ptr()", "")
                     elif ty_info.passed_as_ptr:
-                        opaque_arg_conv = opaque_arg_conv + "\n// Warning: we need a move here but no clone is available for " + ty_info.rust_obj
+                        opaque_arg_conv += "\n// WARNING: we need a move here but no clone is available for " + ty_info.rust_obj + "\n"
                         # TODO: Once we support features cloning (which just isn't in C yet), we can make this a compile error instead!
                         from_hu_conv = (from_hu_conv[0], from_hu_conv[1] + ";\n" +
                             "// Due to rust's strict-ownership memory model, in some cases we need to \"move\"\n" +
@@ -275,40 +322,33 @@ class TypeMappingGenerator:
                             "// at the FFI layer, creating a new object which Rust can claim ownership of\n" +
                             "// However, in some cases (eg here), there is no way to clone an object, and thus\n" +
                             "// we actually have to pass full ownership to Rust.\n" +
-                            "// Thus, after this call, " + ty_info.var_name + " is reset to null and is now a dummy object.\n" + ty_info.var_name + ".ptr = 0")
+                            "// Thus, after this call, " + ty_info.var_name + " is reset to null and is now a dummy object.\n" + self.consts.set_null_skip_free(ty_info.var_name))
+                elif not is_free:
+                    opaque_arg_conv += "\n" + ty_info.var_name + "_conv.is_owned = false;"
 
                 opaque_ret_conv_suf = ";\n"
-                opaque_ret_conv_suf += "uint64_t " + ty_info.var_name + "_ref = 0;\n"
-                indent = ""
-                if is_nullable:
-                    opaque_ret_conv_suf += "if ((uint64_t)" + ty_info.var_name + "_var.inner > 4096) {\n"
-                    indent = "\t"
+                opaque_ret_conv_suf += self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = 0;\n"
                 if not holds_ref and ty_info.is_ptr and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns: # is_ptr, not holds_ref implies passing a pointed-to value to java, which needs copied
-                    opaque_ret_conv_suf += indent + ty_info.var_name + "_var = " + ty_info.rust_obj.replace("LDK", "") + "_clone(" + ty_info.var_name + ");\n"
+                    opaque_ret_conv_suf += ty_info.var_name + "_var = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_var);\n"
                 elif not holds_ref and ty_info.is_ptr:
-                    opaque_ret_conv_suf += indent + "// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
+                    opaque_ret_conv_suf += "// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
 
-                opaque_ret_conv_suf += indent + "CHECK((((uint64_t)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
-                opaque_ret_conv_suf += indent + "CHECK((((uint64_t)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
+                opaque_ret_conv_suf += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_var);\n"
                 if holds_ref:
-                    opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_var.inner & ~1;"
+                    opaque_ret_conv_suf += ty_info.var_name + "_ref = tag_ptr(" + ty_info.var_name + "_var.inner, false);"
                 else:
-                    opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_var.inner;\n"
-                    opaque_ret_conv_suf += indent + "if (" + ty_info.var_name + "_var.is_owned) {\n"
-                    opaque_ret_conv_suf += indent + "\t" + ty_info.var_name + "_ref |= 1;\n"
-                    opaque_ret_conv_suf += indent + "}"
-                if is_nullable:
-                    opaque_ret_conv_suf += "\n}"
+                    opaque_ret_conv_suf += ty_info.var_name + "_ref = tag_ptr(" + ty_info.var_name + "_var.inner, " + ty_info.var_name + "_var.is_owned);"
 
                 to_hu_conv_sfx = ""
                 if not ty_info.is_ptr or holds_ref:
-                    to_hu_conv_sfx = "\n" + ty_info.var_name + "_hu_conv.ptrs_to.add(this);"
+                    to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
+                qualified_hu_ty = self.consts.fully_qualified_hu_ty_path(ty_info)
                 if ty_info.is_ptr:
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = *", opaque_ret_conv_suf),
                         ret_conv_name = ty_info.var_name + "_ref",
-                        to_hu_conv = self.consts.to_hu_conv_templates['ptr'].replace('{human_type}', ty_info.java_hu_ty).replace('{var_name}', ty_info.var_name) + to_hu_conv_sfx,
+                        to_hu_conv = self.consts.to_hu_conv_templates['ptr'].replace('{human_type}', qualified_hu_ty).replace('{var_name}', ty_info.var_name) + to_hu_conv_sfx,
                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
                         from_hu_conv = from_hu_conv)
                 else:
@@ -316,7 +356,7 @@ class TypeMappingGenerator:
                         arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", opaque_ret_conv_suf),
                         ret_conv_name = ty_info.var_name + "_ref",
-                        to_hu_conv = self.consts.to_hu_conv_templates['default'].replace('{human_type}', ty_info.java_hu_ty).replace('{var_name}', ty_info.var_name) + to_hu_conv_sfx,
+                        to_hu_conv = self.consts.to_hu_conv_templates['default'].replace('{human_type}', qualified_hu_ty).replace('{var_name}', ty_info.var_name) + to_hu_conv_sfx,
                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
                         from_hu_conv = from_hu_conv)
 
@@ -331,68 +371,93 @@ class TypeMappingGenerator:
                         arg_conv_cleanup = None,
                         ret_conv = (ty_info.c_ty + " " + ty_info.var_name + "_conv = " + ret_pfx, ret_sfx + ";"),
                         ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
-                base_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
+                base_conv = "void* " + ty_info.var_name + "_ptr = untag_ptr(" + ty_info.var_name + ");\n"
                 base_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
                 base_conv += ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)(" + ty_info.var_name + "_ptr);"
+                from_hu_conv = None
                 if ty_info.rust_obj in self.trait_structs:
                     ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_ret = ", ";")
                     if holds_ref:
                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
                             ret_conv = (ret_conv[0] + ty_info.rust_obj.replace("LDK", "") + "_clone(&", ");")
                         else:
-                            ret_conv = (ret_conv[0], ";\n// Warning: We likely need to clone here, but no clone is available, so we just do it for Java instances")
+                            ret_conv = (ret_conv[0], ";\n// WARNING: We likely need to clone here, but no clone is available, so we just do it for Java instances")
                             ret_conv = (ret_conv[0], ret_conv[1] + "" + self.consts.trait_struct_inc_refcnt(ty_info).replace(ty_info.var_name + "_conv", "(*" + ty_info.var_name + "_ret)"))
                     if not is_free:
                         needs_full_clone = not is_free and (not ty_info.is_ptr and not holds_ref or ty_info.requires_clone == True) and ty_info.requires_clone != False
                         if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
-                            base_conv = base_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
+                            # arg_conv is used when converting a function argument from java normally (with holds_ref set),
+                            # and when converting a java value being returned from a trait method (with holds_ref unset).
+                            # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
+                            # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
+                            if holds_ref:
+                                base_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
+                            else:
+                                from_hu_conv = (ty_info.var_name + ".clone_ptr()", "")
+                                base_conv += "\n" + "FREE(untag_ptr(" + ty_info.var_name + "));"
                         else:
                             base_conv = base_conv + self.consts.trait_struct_inc_refcnt(ty_info)
                             if needs_full_clone:
-                                base_conv = base_conv + "// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
+                                base_conv += "// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
                     else:
-                        base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
+                        base_conv = base_conv + "\n" + "FREE(untag_ptr(" + ty_info.var_name + "));"
+                    if from_hu_conv is None:
+                        from_hu_conv = (self.consts.get_ptr(ty_info.var_name), "")
+                    from_hu_conv = (from_hu_conv[0], self.consts.add_ref("this", ty_info.var_name))
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
-                        ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_ret",
-                        to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");\nret_hu_conv.ptrs_to.add(this);",
-                        to_hu_conv_name = "ret_hu_conv",
-                        from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", "this.ptrs_to.add(" + ty_info.var_name + ")"))
+                        ret_conv = ret_conv, ret_conv_name = "tag_ptr(" + ty_info.var_name + "_ret, true)",
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, "ret_hu_conv", "new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ")") + ";\n" + self.consts.add_ref("ret_hu_conv", "this") + ";",
+                        to_hu_conv_name = "ret_hu_conv", from_hu_conv = from_hu_conv)
                 needs_full_clone = not is_free and (not ty_info.is_ptr or ty_info.requires_clone == True) and ty_info.requires_clone != False
                 if needs_full_clone:
                     if "res" in ty_info.var_name: # XXX: This is a stupid hack
                         needs_full_clone = False
                     if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
-                        base_conv = base_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone((" + ty_info.rust_obj + "*)(((uint64_t)" + ty_info.var_name + ") & ~1));"
+                        # arg_conv is used when converting a function argument from java normally (with holds_ref set),
+                        # and when converting a java value being returned from a trait method (with holds_ref unset).
+                        # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
+                        # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
+                        if holds_ref:
+                            base_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone((" + ty_info.rust_obj + "*)untag_ptr(" + ty_info.var_name + "));"
+                        else:
+                            from_hu_conv = (ty_info.var_name + " == null ? " + self.consts.native_zero_ptr + " : " + ty_info.var_name + ".clone_ptr()", "")
+                            base_conv += "\n" + "FREE(untag_ptr(" + ty_info.var_name + "));"
                     elif needs_full_clone:
-                        base_conv = base_conv + "\n// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj
+                        base_conv = base_conv + "\n// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj
                 if not needs_full_clone and ty_info.rust_obj != "LDKu8slice" and (not holds_ref or is_free):
                     # Don't bother free'ing slices passed in - Rust doesn't auto-free the
                     # underlying unlike Vecs, and it gives Java more freedom.
-                    base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");"
+                    base_conv = base_conv + "\nFREE(untag_ptr(" + ty_info.var_name + "));"
                 if ty_info.rust_obj in self.complex_enums:
                     if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
                         # We really need a full clone here, but for now we just implement
                         # a manual clone explicitly for Option<Trait>s
-                        if ty_info.rust_obj.startswith("LDKCOption"):
+                        if ty_info.contains_trait:
+                            assert ty_info.rust_obj.startswith("LDKCOption") # We don't support contained traits for anything else yet
                             optional_ty = ty_info.rust_obj[11:-1]
-                            if "LDK" + optional_ty in self.trait_structs:
-                                base_conv += "\nif (" + ty_info.var_name + "_conv.tag == " + ty_info.rust_obj + "_Some) {"
-                                base_conv += "\n\t// Manually implement clone for Java trait instances"
-                                optional_ty_info = self.java_c_types("LDK" + optional_ty + " " + ty_info.var_name, None)
-                                base_conv += self.consts.trait_struct_inc_refcnt(optional_ty_info).\
-                                    replace("\n", "\n\t").replace(ty_info.var_name + "_conv", ty_info.var_name + "_conv.some")
-                                base_conv += "\n}"
-                    ret_conv = ("uint64_t " + ty_info.var_name + "_ref = ((uint64_t)&", ") | 1;")
+                            assert "LDK" + optional_ty in self.trait_structs # We don't support contained traits for anything else yet
+                            base_conv += "\nif (" + ty_info.var_name + "_conv.tag == " + ty_info.rust_obj + "_Some) {"
+                            base_conv += "\n\t// Manually implement clone for Java trait instances"
+                            optional_ty_info = self.java_c_types("LDK" + optional_ty + " " + ty_info.var_name, None)
+                            base_conv += self.consts.trait_struct_inc_refcnt(optional_ty_info).\
+                                replace("\n", "\n\t").replace(ty_info.var_name + "_conv", ty_info.var_name + "_conv.some")
+                            base_conv += "\n}"
+                    ret_conv = (self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = tag_ptr(&", ", false);")
                     if not holds_ref:
                         ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_copy = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n", "")
                         ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = ", "")
-                        ret_conv = (ret_conv[0], ";\nuint64_t " + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_copy;")
+                        ret_conv = (ret_conv[0], ";\n" + self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = tag_ptr(" + ty_info.var_name + "_copy, true);")
+                    if from_hu_conv is None:
+                        from_hu_conv = (self.consts.get_ptr(ty_info.var_name), "")
+                    from_hu_conv = (from_hu_conv[0], self.consts.add_ref("this", ty_info.var_name))
+                    fully_qualified_ty = self.consts.fully_qualified_hu_ty_path(ty_info)
+                    to_hu_call = fully_qualified_ty + ".constr_from_ptr(" + ty_info.var_name + ")"
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = ret_conv, ret_conv_name = ty_info.var_name + "_ref",
-                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");\n" + ty_info.var_name + "_hu_conv.ptrs_to.add(this);",
-                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))
+                        to_hu_conv = self.consts.var_decl_statement(fully_qualified_ty, ty_info.var_name + "_hu_conv", to_hu_call) + ";\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";",
+                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
                 if ty_info.rust_obj in self.result_types:
                     if holds_ref:
                         # If we're trying to return a ref, we have to clone.
@@ -401,82 +466,101 @@ class TypeMappingGenerator:
                         ret_conv = (ret_conv[0], ret_conv[1] + "\n*" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(" + ty_info.var_name + "_conv);")
                     else:
                         ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_conv = ", ";")
+                    if from_hu_conv is None:
+                        from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : " + self.consts.native_zero_ptr, "")
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
-                        ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_conv",
-                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");",
-                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + " != null ? " + ty_info.var_name + ".ptr : 0", ""))
+                        ret_conv = ret_conv, ret_conv_name = "tag_ptr(" + ty_info.var_name + "_conv, true)",
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_hu_conv", ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ")") + ";",
+                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
                 if ty_info.rust_obj in self.tuple_types:
-                    ret_conv_name = "((uint64_t)" + ty_info.var_name + "_conv)"
+                    ret_conv_name = "tag_ptr(" + ty_info.var_name + "_conv, "
                     if holds_ref:
                         # If we're trying to return a ref, we have to clone.
                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
                             ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = &", "")
-                            ret_conv = (ret_conv[0], ";\n// Warning: we really need to clone here, but no clone is available for " + ty_info.rust_obj)
-                            ret_conv_name += " | 1"
+                            ret_conv = (ret_conv[0], ";\n// WARNING: we really need to clone here, but no clone is available for " + ty_info.rust_obj)
+                            ret_conv_name += "false)"
                         else:
                             ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_conv = ", ";")
                             ret_conv = (ret_conv[0], ret_conv[1] + "\n*" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(" + ty_info.var_name + "_conv);")
+                            ret_conv_name += "true)"
                     else:
                         ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_conv = ", ";")
+                        ret_conv_name += "true)"
                     if not ty_info.is_ptr or holds_ref:
-                        to_hu_conv_sfx = "\n" + ty_info.var_name + "_hu_conv.ptrs_to.add(this);"
+                        to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
                     else:
                         to_hu_conv_sfx = ""
+                    if from_hu_conv is None:
+                        from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : " + self.consts.native_zero_ptr, "")
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = ret_conv, ret_conv_name = ret_conv_name,
-                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");" + to_hu_conv_sfx,
-                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + " != null ? " + ty_info.var_name + ".ptr : 0", ""))
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_hu_conv", "new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ")") + ";" + to_hu_conv_sfx,
+                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
 
-                # The manually-defined types - TxOut and u5
-                if ty_info.rust_obj == "LDKu5":
+                # The manually-defined types - TxIn, TxOut, BigEndianScalar, U5, and Error
+                if ty_info.rust_obj == "LDKError":
+                    assert from_hu_conv is None
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                        arg_conv = "", arg_conv_name = "(LDKu5){ ._0 = " + ty_info.var_name + " }", arg_conv_cleanup = None,
+                        arg_conv = "", arg_conv_name = "(LDKError){ ._dummy = 0 }", arg_conv_cleanup = None,
+                        ret_conv = ("/*", "*/"), ret_conv_name = "0",
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_conv", "new " + ty_info.java_hu_ty + "(" + ty_info.var_name + ")") + ";",
+                        to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = ("0", ""))
+
+                if ty_info.rust_obj == "LDKU5" or ty_info.rust_obj == "LDKWitnessVersion":
+                    assert from_hu_conv is None
+                    return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                        arg_conv = "", arg_conv_name = "(" + ty_info.rust_obj + "){ ._0 = " + ty_info.var_name + " }", arg_conv_cleanup = None,
                         ret_conv = ("uint8_t " + ty_info.var_name + "_val = ", "._0;"), ret_conv_name = ty_info.var_name + "_val",
-                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_conv = new " + ty_info.java_hu_ty + "(" + ty_info.var_name + ");",
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_conv", "new " + ty_info.java_hu_ty + "(" + ty_info.var_name + ")") + ";",
                         to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".getVal()", ""))
 
-                assert ty_info.rust_obj == "LDKTxOut"
+                assert ty_info.rust_obj == "LDKWitnessProgram" or ty_info.rust_obj == "LDKTxOut" or ty_info.rust_obj == "LDKTxIn" or ty_info.rust_obj == "LDKBigEndianScalar"
                 if not ty_info.is_ptr and not holds_ref:
-                    ret_conv = ("LDKTxOut* " + ty_info.var_name + "_ref = MALLOC(sizeof(LDKTxOut), \"LDKTxOut\");\n*" + ty_info.var_name + "_ref = ", ";")
+                    ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_ref = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_ref = ", ";")
+                    ret_conv_name = "tag_ptr(" + ty_info.var_name + "_ref, true)"
                 else:
-                    ret_conv = ("uint64_t " + ty_info.var_name + "_ref = ((uint64_t)&", ") | 1;")
+                    ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_ref = &", ";")
+                    ret_conv_name = "tag_ptr(" + ty_info.var_name + "_ref, false)"
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
-                    ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_ref",
-                    to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_conv = new " +ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");",
-                    to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))
+                    ret_conv = ret_conv, ret_conv_name = ret_conv_name,
+                    to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_conv", "new " +ty_info.java_hu_ty + "(null, " + ty_info.var_name + ")") + ";",
+                    to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (self.consts.get_ptr(ty_info.var_name), ""))
             elif ty_info.is_ptr:
                 assert(not is_free)
                 if ty_info.rust_obj in self.complex_enums:
-                    ret_conv = ("uint64_t ret_" + ty_info.var_name + " = (uint64_t)", " | 1; // Warning: We should clone here!")
-                    from_hu_sfx = "this.ptrs_to.add(" + ty_info.var_name + ")"
+                    ret_conv = (self.consts.ptr_c_ty + " ref_" + ty_info.var_name + " = tag_ptr(", ", false); // WARNING: We should clone here!")
+                    from_hu_sfx = self.consts.add_ref("this", ty_info.var_name)
                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
                         ret_conv_pfx = ty_info.rust_obj + " *ret_" + ty_info.var_name + " = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + " ret conversion\");\n"
                         ret_conv_pfx += "*ret_" + ty_info.var_name + " = " + ty_info.rust_obj.replace("LDK", "") + "_clone("
-                        ret_conv = (ret_conv_pfx, ");")
+                        ret_conv_sfx = ");\n" + self.consts.ptr_c_ty + " ref_" + ty_info.var_name + " = tag_ptr(ret_" + ty_info.var_name + ", true);"
+                        ret_conv = (ret_conv_pfx, ret_conv_sfx)
                         from_hu_sfx = ""
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                        arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
+                        arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)untag_ptr(" + ty_info.var_name + ");",
                         arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
-                        ret_conv = ret_conv, ret_conv_name = "(uint64_t)ret_" + ty_info.var_name,
-                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");",
+                        ret_conv = ret_conv, ret_conv_name = "ref_" + ty_info.var_name,
+                        to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, ty_info.var_name + "_hu_conv", ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ")") + ";",
                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
-                        from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr & ~1", from_hu_sfx))
+                        from_hu_conv = (ty_info.var_name + " == null ? " + self.consts.native_zero_ptr + " : " + self.consts.get_ptr(ty_info.var_name), from_hu_sfx))
                 elif ty_info.rust_obj in self.trait_structs:
                     if ty_info.nonnull_ptr:
-                        arg_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
-                        arg_conv += "if (!(" + ty_info.var_name + " & 1)) { CHECK_ACCESS(" + ty_info.var_name + "_ptr); }\n"
+                        arg_conv = "void* " + ty_info.var_name + "_ptr = untag_ptr(" + ty_info.var_name + ");\n"
+                        arg_conv += "if (ptr_is_owned(" + ty_info.var_name + ")) { CHECK_ACCESS(" + ty_info.var_name + "_ptr); }\n"
                         arg_conv += ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
                         arg_conv_name = ty_info.var_name + "_conv"
+                        from_hu_conv_pfx = self.consts.get_ptr(ty_info.var_name)
                     else:
                         # We map Option<Trait> as *mut Trait, which we can differentiate from &Trait by the NONNULL_PTR annotation.
                         # We handle the Option<Trait> case here.
                         arg_conv = ty_info.rust_obj + " *" + ty_info.var_name + "_conv_ptr = NULL;\n"
                         arg_conv += "if (" + ty_info.var_name + " != 0) {\n"
                         arg_conv += "\t" + ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
-                        arg_conv += "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
+                        arg_conv += "void* " + ty_info.var_name + "_ptr = untag_ptr(" + ty_info.var_name + ");\n"
                         arg_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
                         arg_conv += "\t" + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
                         arg_conv += self.consts.trait_struct_inc_refcnt(ty_info).replace("\n", "\n\t")
@@ -484,26 +568,28 @@ class TypeMappingGenerator:
                         arg_conv += "\t*" + ty_info.var_name + "_conv_ptr = " + ty_info.var_name + "_conv;\n"
                         arg_conv += "}"
                         arg_conv_name = ty_info.var_name + "_conv_ptr"
+                        from_hu_conv_pfx = ty_info.var_name + " == null ? " + self.consts.native_zero_ptr + " : " + self.consts.get_ptr(ty_info.var_name)
                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
                             ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_clone = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n" +
                                 "*" + ty_info.var_name + "_clone = " + ty_info.rust_obj.replace("LDK", "") + "_clone(", ");"),
-                            ret_conv_name = "(uint64_t)" + ty_info.var_name + "_clone",
-                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");\nret_hu_conv.ptrs_to.add(this);",
-                            to_hu_conv_name = "ret_hu_conv",
-                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", ""))
+                            ret_conv_name = "tag_ptr(" + ty_info.var_name + "_clone, true)",
+                            to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, "ret_hu_conv", "new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ")") + ";\n" + self.consts.add_ref("ret_hu_conv", "this") + ";",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = (from_hu_conv_pfx, ""))
                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
-                            ret_conv = ("// WARNING: This object doesn't live past this scope, needs clone!\nuint64_t ret_" + ty_info.var_name + " = ((uint64_t)", ") | 1;"),
+                            ret_conv = ("// WARNING: This object doesn't live past this scope, needs clone!\n" + self.consts.ptr_c_ty + " ret_" + ty_info.var_name + " = tag_ptr(", ", false);"),
                             ret_conv_name = "ret_" + ty_info.var_name,
-                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");\nret_hu_conv.ptrs_to.add(this);",
-                            to_hu_conv_name = "ret_hu_conv",
-                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", "this.ptrs_to.add(" + ty_info.var_name + ")"))
+                            to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, "ret_hu_conv", "new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ")") + ";\n" + self.consts.add_ref("ret_hu_conv", "this") + ";",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = (from_hu_conv_pfx, self.consts.add_ref("this", ty_info.var_name)))
+                ret_conv = (self.consts.ptr_c_ty + " ret_" + ty_info.var_name + " = tag_ptr(", ", true);")
+                if holds_ref:
+                    ret_conv = (ret_conv[0], ", false);")
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)(" + ty_info.var_name + " & ~1);",
+                    arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)untag_ptr(" + ty_info.var_name + ");",
                     arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
-                    ret_conv = ("uint64_t ret_" + ty_info.var_name + " = (uint64_t)", ";"), ret_conv_name = "ret_" + ty_info.var_name,
+                    ret_conv = ret_conv, ret_conv_name = "ret_" + ty_info.var_name,
                     to_hu_conv = "TODO 3", to_hu_conv_name = None, from_hu_conv = None) # its a pointer, no conv needed
             assert False # We should have handled every case by now.