Merge pull request #103 from TheBlueMatt/main
[ldk-java] / gen_type_mapping.py
1 from bindingstypes import ConvInfo
2
3 class TypeMappingGenerator:
4
5     def __init__(self, java_c_types, consts, opaque_structs, clone_fns, unitary_enums, trait_structs, complex_enums, result_types, tuple_types):
6         # trick our way around circular imports
7         self.java_c_types = java_c_types
8         self.consts = consts
9         self.opaque_structs = opaque_structs
10         self.clone_fns = clone_fns
11         self.unitary_enums = unitary_enums
12         self.trait_structs = trait_structs
13         self.complex_enums = complex_enums
14         self.result_types = result_types
15         self.tuple_types = tuple_types
16
17     def map_type(self, fn_arg, print_void, ret_arr_len, is_free, holds_ref):
18         ty_info = self.java_c_types(fn_arg, ret_arr_len)
19         mapped_info = self.map_type_with_info(ty_info, print_void, ret_arr_len, is_free, holds_ref, False)
20         return mapped_info
21
22     def map_nullable_type(self, fn_arg, print_void, ret_arr_len, is_free, holds_ref):
23         ty_info = self.java_c_types(fn_arg, ret_arr_len)
24         mapped_info = self.map_type_with_info(ty_info, print_void, ret_arr_len, is_free, holds_ref, True)
25         return mapped_info
26
27     def map_type_with_info(self, ty_info, print_void, ret_arr_len, is_free, holds_ref, is_nullable):
28         mapped_info = self._do_map_type_with_info(ty_info, print_void, ret_arr_len, is_free, holds_ref, is_nullable)
29         if is_nullable:
30             mapped_info.nullable = True
31         return mapped_info
32
33     def _do_map_type_with_info(self, ty_info, print_void, ret_arr_len, is_free, holds_ref, is_nullable):
34         if ty_info.c_ty == "void":
35             if not print_void:
36                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
37                     arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
38                     ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
39         if ty_info.c_ty.endswith("Array"):
40             arr_len = ty_info.arr_len
41             if arr_len is not None:
42                 arr_name = ty_info.var_name
43             else:
44                 arr_name = "ret"
45                 arr_len = ret_arr_len
46             if ty_info.c_ty == "int8_tArray":
47                 (set_pfx, set_sfx) = self.consts.set_native_arr_contents(arr_name + "_arr", arr_len, ty_info)
48                 ret_conv = ("int8_tArray " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_len, ty_info) + ";\n" + set_pfx, "")
49                 arg_conv_cleanup = None
50                 if not arr_len.isdigit():
51                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
52                     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"
53                     if (not ty_info.is_ptr or not holds_ref) and ty_info.rust_obj != "LDKu8slice":
54                         arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = MALLOC(" + arr_name + "_ref." + arr_len + ", \"" + ty_info.rust_obj + " Bytes\");\n"
55                         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) + ";"
56                     else:
57                         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) + ";"
58                         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)
59                     if ty_info.rust_obj == "LDKTransaction":
60                         arg_conv = arg_conv + "\n" + arr_name + "_ref.data_is_owned = " + str(holds_ref).lower() + ";"
61                     ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
62                     ret_conv = (ret_conv[0], ";\nint8_tArray " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_name + "_var." + arr_len, ty_info) + ";\n")
63                     (pfx, sfx) = self.consts.set_native_arr_contents(arr_name + "_arr", arr_name + "_var." + arr_len, ty_info)
64                     ret_conv = (ret_conv[0], ret_conv[1] + pfx + arr_name + "_var." + ty_info.arr_access + sfx + ";")
65                     if not holds_ref and ty_info.rust_obj != "LDKu8slice":
66                         ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
67                     from_hu_conv = self.consts.primitive_arr_from_hu(ty_info.subty, None, arr_name)
68                     to_hu_conv = self.consts.primitive_arr_to_hu(ty_info.subty, None, arr_name, arr_name + "_conv")
69                 elif ty_info.rust_obj is not None:
70                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
71                     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"
72                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_ref." + ty_info.arr_access, arr_len, ty_info, True) + ";"
73                     ret_conv = (ret_conv[0], "." + ty_info.arr_access + set_sfx + ";")
74                     from_hu_conv = self.consts.primitive_arr_from_hu(ty_info.subty, arr_len, arr_name)
75                     to_hu_conv = self.consts.primitive_arr_to_hu(ty_info.subty, None, arr_name, arr_name + "_conv")
76                 else:
77                     arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n"
78                     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"
79                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_arr", arr_len, ty_info, True) + ";\n"
80                     arg_conv = arg_conv + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
81                     ret_conv = (ret_conv[0] + "*", set_sfx + ";")
82                     from_hu_conv = self.consts.primitive_arr_from_hu(ty_info.subty, arr_len, arr_name)
83                     to_hu_conv = self.consts.primitive_arr_to_hu(ty_info.subty, None, arr_name, arr_name + "_conv")
84                 to_hu_conv_name = None
85                 if to_hu_conv is not None:
86                     to_hu_conv_name = arr_name + "_conv"
87                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
88                     arg_conv = arg_conv, arg_conv_name = arr_name + "_ref", arg_conv_cleanup = arg_conv_cleanup,
89                     ret_conv = ret_conv, ret_conv_name = arr_name + "_arr",
90                     to_hu_conv = to_hu_conv, to_hu_conv_name = to_hu_conv_name,
91                     from_hu_conv = from_hu_conv)
92             else:
93                 assert not arr_len.isdigit() # fixed length arrays not implemented
94                 assert ty_info.java_hu_ty[len(ty_info.java_hu_ty) - 2:] == "[]"
95                 if arr_name == "":
96                     arr_name = "ret"
97                 conv_name = arr_name + "_conv_" + str(len(ty_info.java_hu_ty))
98                 idxc = chr(ord('a') + (len(ty_info.java_hu_ty) % 26))
99                 ty_info.subty.var_name = conv_name
100                 #XXX: We'd really prefer to only ever set to False, avoiding lots of clone, but need smarter free logic
101                 #if ty_info.is_ptr or holds_ref:
102                 #    ty_info.subty.requires_clone = False
103                 ty_info.subty.requires_clone = not ty_info.is_ptr or not holds_ref
104                 if not ty_info.subty.is_native_primitive and ty_info.subty.rust_obj == "LDKChannelMonitor":
105                     # We take a Vec of references to ChannelMonitors as input to ChannelManagerReadArgs, if we clone them,
106                     # we end up freeing the clones after creating the ChannelManagerReadArgs before calling the read
107                     # function itself, resulting in a segfault. Thus, we manually check and ensure we don't clone for
108                     # ChannelMonitors inside of vecs.
109                     ty_info.subty.requires_clone = False
110                 subty = self.map_type_with_info(ty_info.subty, False, None, is_free, holds_ref, False)
111                 arg_conv = ty_info.rust_obj + " " + arr_name + "_constr;\n"
112                 pf = ""
113                 if ty_info.is_ptr:
114                     pf = "\t"
115                     arg_conv += ty_info.rust_obj + " *" + arr_name + "_ptr = NULL;\n"
116                     arg_conv += "if (" + self.consts.is_arr_some_check[0] + arr_name + self.consts.is_arr_some_check[1] + ") {\n"
117                 arg_conv += pf + arr_name + "_constr." + arr_len + " = " + self.consts.get_native_arr_len_call[0] + arr_name + self.consts.get_native_arr_len_call[1] + ";\n"
118                 arg_conv += pf + "if (" + arr_name + "_constr." + arr_len + " > 0)\n"
119                 if subty.is_native_primitive:
120                     szof = subty.c_ty
121                 else:
122                     szof = subty.rust_obj
123                 arg_conv += pf + "\t" + arr_name + "_constr." + ty_info.arr_access + " = MALLOC(" + arr_name + "_constr." + arr_len + " * sizeof(" + szof + "), \"" + ty_info.rust_obj + " Elements\");\n"
124                 arg_conv += pf + "else\n"
125                 arg_conv += pf + "\t" + arr_name + "_constr." + ty_info.arr_access + " = NULL;\n"
126                 get_arr = self.consts.get_native_arr_contents(arr_name, "NO_DEST", arr_name + "_constr." + arr_len, ty_info, False)
127                 if get_arr != None:
128                     arg_conv += pf + subty.c_ty + "* " + arr_name + "_vals = " + get_arr + ";\n"
129                 arg_conv += pf + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_constr." + arr_len + "; " + idxc + "++) {\n"
130                 if get_arr != None:
131                     arg_conv += pf + "\t" + subty.c_ty + " " + conv_name + " = " + arr_name + "_vals[" + idxc + "];"
132                     if subty.arg_conv is not None:
133                         arg_conv += "\n\t" + pf + subty.arg_conv.replace("\n", "\n\t" + pf)
134                 else:
135                     arg_conv += pf + "\t" + subty.c_ty + " " + conv_name + " = " + self.consts.get_native_arr_elem(arr_name, idxc, ty_info) + ";\n"
136                     arg_conv += pf + "\t" + subty.arg_conv.replace("\n", "\n\t" + pf)
137                 arg_conv += "\n\t" + pf + arr_name + "_constr." + ty_info.arr_access + "[" + idxc + "] = " + subty.arg_conv_name + ";\n" + pf + "}"
138                 if get_arr != None:
139                     cleanup = self.consts.cleanup_native_arr_ref_contents(arr_name, arr_name + "_vals", arr_name + "_constr." + arr_len, ty_info)
140                     if cleanup is not None:
141                         arg_conv += "\n" + pf + cleanup + ";"
142                 if ty_info.is_ptr:
143                     arg_conv_name = arr_name + "_ptr"
144                 else:
145                     arg_conv_name = arr_name + "_constr"
146                 arg_conv_cleanup = None
147                 if ty_info.is_ptr:
148                     arg_conv_cleanup = "if (" + arr_name + "_ptr != NULL) { FREE(" + arr_name + "_constr." + ty_info.arr_access + "); }"
149                 if ty_info.is_ptr:
150                     arg_conv += "\n\t" + arr_name + "_ptr = &" + arr_name + "_constr;\n}"
151
152                 if is_nullable:
153                     ret_conv = (ty_info.rust_obj + " *" + arr_name + "_var_ptr = ", "")
154                 else:
155                     ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
156                 if subty.ret_conv is None:
157                     ret_conv = ("DUMMY", "DUMMY")
158                 else:
159                     ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = NULL;\n")
160                     indent = ""
161                     if is_nullable:
162                         ret_conv = (ret_conv[0], ret_conv[1] + "if (" + arr_name + " != NULL) {\n")
163                         ret_conv = (ret_conv[0], ret_conv[1] + "\t" + ty_info.rust_obj + " " + arr_name + "_var = *" + arr_name + "_var_ptr;\n")
164                         indent = "\t"
165                     ret_conv = (ret_conv[0], ret_conv[1] + indent + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_name + "_var." + arr_len, ty_info) + ";\n")
166                     get_ptr_call = self.consts.get_native_arr_ptr_call(ty_info)
167                     if get_ptr_call is not None:
168                         ret_conv = (ret_conv[0], ret_conv[1] + indent + subty.c_ty + " *" + arr_name + "_arr_ptr = " + get_ptr_call[0] + arr_name + "_arr" + get_ptr_call[1] + ";\n")
169                     ret_conv = (ret_conv[0], ret_conv[1] + indent + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_var." + arr_len + "; " + idxc + "++) {\n")
170                     ret_conv = (ret_conv[0], ret_conv[1] + indent + "\t" + subty.ret_conv[0].replace("\n", "\n\t" + indent))
171                     ret_conv = (ret_conv[0], ret_conv[1] + indent + arr_name + "_var." + ty_info.arr_access + "[" + idxc + "]" + subty.ret_conv[1].replace("\n", "\n\t" + indent) + "\n")
172                     if get_ptr_call is not None:
173                         ret_conv = (ret_conv[0], ret_conv[1] + indent + "\t" + arr_name + "_arr_ptr[" + idxc + "] = " + subty.ret_conv_name + ";\n" + indent + "}\n")
174                     else:
175                         ret_conv = (ret_conv[0], ret_conv[1] + indent + "\t" + self.consts.get_native_arr_entry_call(ty_info, arr_name + "_arr", idxc, subty.ret_conv_name) + ";\n" + indent + "}\n")
176                     cleanup = self.consts.release_native_arr_ptr_call(ty_info, arr_name + "_arr", arr_name + "_arr_ptr")
177                     if cleanup is not None:
178                         ret_conv = (ret_conv[0], ret_conv[1] + indent + cleanup + ";")
179                     if not holds_ref and not is_nullable:
180                         # XXX: The commented if's are a bit smarter freeing, but we need to be a nudge smarter still
181                         # Note that we don't drop the full vec here - we're passing ownership to java (or have cloned) or free'd by now!
182                         ret_conv = (ret_conv[0], ret_conv[1] + "\n" + indent + "FREE(" + arr_name + "_var." + ty_info.arr_access + ");")
183                         #if subty.rust_obj is not None and subty.rust_obj in self.opaque_structs:
184                         #    ret_conv = (ret_conv[0], ret_conv[1] + "\nFREE(" + arr_name + "_var." + ty_info.arr_access + ");")
185                         #else:
186                         #    ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
187                     if is_nullable:
188                         ret_conv = (ret_conv[0], ret_conv[1] + "\n}")
189
190                 to_hu_conv = None
191                 to_hu_conv_name = None
192                 if subty.to_hu_conv is not None:
193                     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"
194                     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"))
195                     to_hu_conv += ";\n" + self.consts.for_n_in_range(idxc, "0", conv_name + "_len") + "\n"
196                     to_hu_conv += "\t" + self.consts.var_decl_statement(subty.java_ty, conv_name, self.consts.get_java_arr_elem(subty, arr_name, idxc)) + ";\n"
197                     to_hu_conv += "\t" + subty.to_hu_conv.replace("\n", "\n\t") + "\n"
198                     to_hu_conv += "\t" + conv_name + "_arr[" + idxc + "] = " + subty.to_hu_conv_name + ";\n}"
199                     cleanup = self.consts.cleanup_converted_native_array(ty_info, arr_name)
200                     if cleanup is not None:
201                         to_hu_conv += "\n" + cleanup
202                     to_hu_conv_name = conv_name + "_arr"
203                 from_hu_conv = self.consts.primitive_arr_from_hu(ty_info.subty, None, arr_name)
204                 if subty.from_hu_conv is not None:
205                     hu_conv_b = ""
206                     if subty.from_hu_conv[1] != "":
207                         iterator = self.consts.for_n_in_arr(conv_name, arr_name, subty)
208                         hu_conv_b = iterator[0] + subty.from_hu_conv[1] + ";" + iterator[1]
209                     if from_hu_conv is not None:
210                         arr_conv = self.consts.primitive_arr_from_hu(ty_info.subty, None, self.consts.map_hu_array_elems(arr_name, conv_name, ty_info, subty))
211                         assert arr_conv[1] == ""
212                         from_hu_conv = (arr_conv[0], hu_conv_b)
213                     else:
214                         from_hu_conv = (self.consts.map_hu_array_elems(arr_name, conv_name, ty_info, subty), hu_conv_b)
215
216                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
217                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = arg_conv_cleanup,
218                     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)
219         elif ty_info.java_fn_ty_arg == "Ljava/lang/String;":
220             assert not is_nullable
221             if not is_free:
222                 arg_conv = "LDKStr " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_c_call(ty_info.var_name) + ";"
223                 arg_conv_name = ty_info.var_name + "_conv"
224             else:
225                 arg_conv = "LDKStr dummy = { .chars = NULL, .len = 0, .chars_is_owned = false };"
226                 arg_conv_name = "dummy"
227             if ty_info.arr_access is None:
228                 assert False
229                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
230                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
231                     ret_conv = ("const char* " + ty_info.var_name + "_str = ",
232                         ";\njstring " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_native_call(ty_info.var_name + "_str", "strlen(" + ty_info.var_name + "_str)") + ";"),
233                     ret_conv_name = ty_info.var_name + "_conv",
234                     to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
235             else:
236                 free_str = ""
237                 if not holds_ref:
238                     free_str = "\nStr_free(" + ty_info.var_name + "_str);"
239                 to_hu_conv = self.consts.str_to_hu_conv(ty_info.var_name)
240                 to_hu_conv_name = None
241                 if to_hu_conv is not None:
242                     to_hu_conv_name = ty_info.var_name + "_conv"
243                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
244                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
245                     ret_conv = ("LDKStr " + ty_info.var_name + "_str = ",
246                         ";\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),
247                     ret_conv_name = ty_info.var_name + "_conv",
248                     to_hu_conv=to_hu_conv, to_hu_conv_name=to_hu_conv_name,
249                     from_hu_conv = self.consts.str_from_hu_conv(ty_info.var_name))
250         elif ty_info.var_name == "" and not print_void:
251             # We don't have a parameter name, and want one, just call it arg
252             if not ty_info.is_native_primitive:
253                 assert(not is_free or ty_info.rust_obj not in self.opaque_structs)
254                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
255                     arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
256                     arg_conv_name = "arg_conv", arg_conv_cleanup = None,
257                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 7", to_hu_conv_name = None, from_hu_conv = None)
258             else:
259                 assert(not is_free)
260                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
261                     arg_conv = None, arg_conv_name = "arg", arg_conv_cleanup = None,
262                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 8", to_hu_conv_name = None, from_hu_conv = None)
263         elif ty_info.is_native_primitive and ty_info.c_ty != "void":
264             assert not is_nullable
265             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
266                 arg_conv = None, arg_conv_name =  ty_info.var_name, arg_conv_cleanup = None,
267                 ret_conv = (ty_info.c_ty + " " + ty_info.var_name + "_conv = ", ";"), ret_conv_name = ty_info.var_name + "_conv",
268                 to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
269         elif ty_info.c_ty == "void":
270             assert ty_info.is_native_primitive
271             assert not is_nullable
272             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
273                 arg_conv = None, arg_conv_name =  ty_info.var_name, arg_conv_cleanup = None,
274                 ret_conv = None, ret_conv_name = ty_info.var_name,
275                 to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
276         else:
277             if ty_info.var_name == "":
278                 ty_info.var_name = "ret"
279
280             if ty_info.rust_obj in self.opaque_structs:
281                 from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name) + " & ~1", self.consts.add_ref("this", ty_info.var_name))
282                 opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
283                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
284                 if ty_info.is_ptr and holds_ref:
285                     opaque_arg_conv += ty_info.var_name + "_conv.is_owned = false;\n"
286                 else:
287                     opaque_arg_conv += ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);\n"
288                 opaque_arg_conv += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_conv);"
289                 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:
290                     if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
291                         # 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.
292                         # arg_conv is used when converting a function argument from java normally (with holds_ref set),
293                         # and when converting a java value being returned from a trait method (with holds_ref unset).
294                         # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
295                         # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
296                         if holds_ref:
297                             opaque_arg_conv = opaque_arg_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
298                             from_hu_conv = (from_hu_conv[0], "")
299                         else:
300                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".clone_ptr()", "")
301                     elif ty_info.passed_as_ptr:
302                         opaque_arg_conv = opaque_arg_conv + "\n// WARNING: we need a move here but no clone is available for " + ty_info.rust_obj
303                         # TODO: Once we support features cloning (which just isn't in C yet), we can make this a compile error instead!
304                         from_hu_conv = (from_hu_conv[0], from_hu_conv[1] + ";\n" +
305                             "// Due to rust's strict-ownership memory model, in some cases we need to \"move\"\n" +
306                             "// an object to pass exclusive ownership to the function being called.\n" +
307                             "// In most cases, we avoid this being visible in GC'd languages by cloning the object\n" +
308                             "// at the FFI layer, creating a new object which Rust can claim ownership of\n" +
309                             "// However, in some cases (eg here), there is no way to clone an object, and thus\n" +
310                             "// we actually have to pass full ownership to Rust.\n" +
311                             "// 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))
312
313                 opaque_ret_conv_suf = ";\n"
314                 opaque_ret_conv_suf += self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = 0;\n"
315                 indent = ""
316                 if is_nullable:
317                     opaque_ret_conv_suf += "if ((uintptr_t)" + ty_info.var_name + "_var.inner > 4096) {\n"
318                     indent = "\t"
319                 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
320                     opaque_ret_conv_suf += indent + ty_info.var_name + "_var = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_var);\n"
321                 elif not holds_ref and ty_info.is_ptr:
322                     opaque_ret_conv_suf += indent + "// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
323
324                 opaque_ret_conv_suf += indent + "CHECK((((uintptr_t)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
325                 opaque_ret_conv_suf += indent + "CHECK((((uintptr_t)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
326                 opaque_ret_conv_suf += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_var);\n"
327                 if holds_ref:
328                     opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uintptr_t)" + ty_info.var_name + "_var.inner & ~1;"
329                 else:
330                     opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uintptr_t)" + ty_info.var_name + "_var.inner;\n"
331                     opaque_ret_conv_suf += indent + "if (" + ty_info.var_name + "_var.is_owned) {\n"
332                     opaque_ret_conv_suf += indent + "\t" + ty_info.var_name + "_ref |= 1;\n"
333                     opaque_ret_conv_suf += indent + "}"
334                 if is_nullable:
335                     opaque_ret_conv_suf += "\n}"
336
337                 to_hu_conv_sfx = ""
338                 if not ty_info.is_ptr or holds_ref:
339                     to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
340                 qualified_hu_ty = self.consts.fully_qualified_hu_ty_path(ty_info)
341                 if ty_info.is_ptr:
342                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
343                         arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
344                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = *", opaque_ret_conv_suf),
345                         ret_conv_name = ty_info.var_name + "_ref",
346                         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,
347                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
348                         from_hu_conv = from_hu_conv)
349                 else:
350                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
351                         arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
352                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", opaque_ret_conv_suf),
353                         ret_conv_name = ty_info.var_name + "_ref",
354                         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,
355                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
356                         from_hu_conv = from_hu_conv)
357
358             assert not is_nullable
359             if not ty_info.is_ptr:
360                 if ty_info.rust_obj in self.unitary_enums:
361                     (ret_pfx, ret_sfx) = self.consts.c_unitary_enum_to_native_call(ty_info)
362                     (arg_pfx, arg_sfx) = self.consts.native_unitary_enum_to_c_call(ty_info)
363                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
364                         arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + arg_pfx + ty_info.var_name + arg_sfx + ";",
365                         arg_conv_name = ty_info.var_name + "_conv",
366                         arg_conv_cleanup = None,
367                         ret_conv = (ty_info.c_ty + " " + ty_info.var_name + "_conv = " + ret_pfx, ret_sfx + ";"),
368                         ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
369                 base_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uintptr_t)" + ty_info.var_name + ") & ~1);\n"
370                 base_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
371                 base_conv += ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)(" + ty_info.var_name + "_ptr);"
372                 from_hu_conv = None
373                 if ty_info.rust_obj in self.trait_structs:
374                     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 = ", ";")
375                     if holds_ref:
376                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
377                             ret_conv = (ret_conv[0] + ty_info.rust_obj.replace("LDK", "") + "_clone(&", ");")
378                         else:
379                             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")
380                             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)"))
381                     if not is_free:
382                         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
383                         if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
384                             # arg_conv is used when converting a function argument from java normally (with holds_ref set),
385                             # and when converting a java value being returned from a trait method (with holds_ref unset).
386                             # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
387                             # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
388                             if holds_ref:
389                                 base_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
390                             else:
391                                 from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".clone_ptr()", "")
392                                 base_conv += "\n" + "FREE((void*)" + ty_info.var_name + ");"
393                         else:
394                             base_conv = base_conv + self.consts.trait_struct_inc_refcnt(ty_info)
395                             if needs_full_clone:
396                                 base_conv = base_conv + "// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
397                     else:
398                         base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
399                     if from_hu_conv is None:
400                         from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name), "")
401                     from_hu_conv = (from_hu_conv[0], self.consts.add_ref("this", ty_info.var_name))
402                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
403                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
404                         ret_conv = ret_conv, ret_conv_name = "(" + self.consts.ptr_c_ty + ")" + ty_info.var_name + "_ret",
405                         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") + ";",
406                         to_hu_conv_name = "ret_hu_conv", from_hu_conv = from_hu_conv)
407                 needs_full_clone = not is_free and (not ty_info.is_ptr or ty_info.requires_clone == True) and ty_info.requires_clone != False
408                 if needs_full_clone:
409                     if "res" in ty_info.var_name: # XXX: This is a stupid hack
410                         needs_full_clone = False
411                     if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
412                         # arg_conv is used when converting a function argument from java normally (with holds_ref set),
413                         # and when converting a java value being returned from a trait method (with holds_ref unset).
414                         # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
415                         # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
416                         if holds_ref:
417                             base_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone((" + ty_info.rust_obj + "*)(((uintptr_t)" + ty_info.var_name + ") & ~1));"
418                         else:
419                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".clone_ptr()", "")
420                             base_conv += "\n" + "FREE((void*)" + ty_info.var_name + ");"
421                     elif needs_full_clone:
422                         base_conv = base_conv + "\n// WARNING: we may need a move here but no clone is available for " + ty_info.rust_obj
423                 if not needs_full_clone and ty_info.rust_obj != "LDKu8slice" and (not holds_ref or is_free):
424                     # Don't bother free'ing slices passed in - Rust doesn't auto-free the
425                     # underlying unlike Vecs, and it gives Java more freedom.
426                     base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");"
427                 if ty_info.rust_obj in self.complex_enums:
428                     to_hu_conv_sfx = ""
429                     if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
430                         # We really need a full clone here, but for now we just implement
431                         # a manual clone explicitly for Option<Trait>s
432                         if ty_info.contains_trait:
433                             assert ty_info.rust_obj.startswith("LDKCOption") # We don't support contained traits for anything else yet
434                             optional_ty = ty_info.rust_obj[11:-1]
435                             assert "LDK" + optional_ty in self.trait_structs # We don't support contained traits for anything else yet
436                             to_hu_conv_sfx = self.consts.add_ref("this", ty_info.var_name)
437                             base_conv += "\nif (" + ty_info.var_name + "_conv.tag == " + ty_info.rust_obj + "_Some) {"
438                             base_conv += "\n\t// Manually implement clone for Java trait instances"
439                             optional_ty_info = self.java_c_types("LDK" + optional_ty + " " + ty_info.var_name, None)
440                             base_conv += self.consts.trait_struct_inc_refcnt(optional_ty_info).\
441                                 replace("\n", "\n\t").replace(ty_info.var_name + "_conv", ty_info.var_name + "_conv.some")
442                             base_conv += "\n}"
443                     ret_conv = (self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = ((uintptr_t)&", ") | 1;")
444                     if not holds_ref:
445                         ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_copy = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n", "")
446                         ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = ", "")
447                         ret_conv = (ret_conv[0], ";\n" + self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = (uintptr_t)" + ty_info.var_name + "_copy;")
448                     if from_hu_conv is None:
449                         from_hu_conv = (self.consts.get_ptr(ty_info.var_name), "")
450                     from_hu_conv = (from_hu_conv[0], to_hu_conv_sfx)
451                     fully_qualified_ty = self.consts.fully_qualified_hu_ty_path(ty_info)
452                     to_hu_call = fully_qualified_ty + ".constr_from_ptr(" + ty_info.var_name + ")"
453                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
454                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
455                         ret_conv = ret_conv, ret_conv_name = ty_info.var_name + "_ref",
456                         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") + ";",
457                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
458                 if ty_info.rust_obj in self.result_types:
459                     if holds_ref:
460                         # If we're trying to return a ref, we have to clone.
461                         # We just blindly assume its implemented and let the compiler fail if its not.
462                         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 = ", ";")
463                         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);")
464                     else:
465                         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 = ", ";")
466                     if from_hu_conv is None:
467                         from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : 0", "")
468                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
469                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
470                         ret_conv = ret_conv, ret_conv_name = "(" + self.consts.ptr_c_ty + ")" + ty_info.var_name + "_conv",
471                         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 + ")") + ";",
472                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
473                 if ty_info.rust_obj in self.tuple_types:
474                     ret_conv_name = "((" + self.consts.ptr_c_ty + ")" + ty_info.var_name + "_conv)"
475                     if holds_ref:
476                         # If we're trying to return a ref, we have to clone.
477                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
478                             ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = &", "")
479                             ret_conv = (ret_conv[0], ";\n// WARNING: we really need to clone here, but no clone is available for " + ty_info.rust_obj)
480                             ret_conv_name += " | 1"
481                         else:
482                             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 = ", ";")
483                             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);")
484                     else:
485                         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 = ", ";")
486                     if not ty_info.is_ptr or holds_ref:
487                         to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
488                     else:
489                         to_hu_conv_sfx = ""
490                     if from_hu_conv is None:
491                         from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : 0", "")
492                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
493                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
494                         ret_conv = ret_conv, ret_conv_name = ret_conv_name,
495                         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,
496                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
497
498                 # The manually-defined types - TxOut, u5, and Error
499                 if ty_info.rust_obj == "LDKError":
500                     assert from_hu_conv is None
501                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
502                         arg_conv = "", arg_conv_name = "(LDKError){ ._dummy = 0 }", arg_conv_cleanup = None,
503                         ret_conv = ("/*", "*/"), ret_conv_name = "0",
504                         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 + ")") + ";",
505                         to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = ("0", ""))
506
507                 if ty_info.rust_obj == "LDKu5" or ty_info.rust_obj == "LDKWitnessVersion":
508                     assert from_hu_conv is None
509                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
510                         arg_conv = "", arg_conv_name = "(" + ty_info.rust_obj + "){ ._0 = " + ty_info.var_name + " }", arg_conv_cleanup = None,
511                         ret_conv = ("uint8_t " + ty_info.var_name + "_val = ", "._0;"), ret_conv_name = ty_info.var_name + "_val",
512                         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 + ")") + ";",
513                         to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".getVal()", ""))
514
515                 assert ty_info.rust_obj == "LDKTxOut"
516                 if not ty_info.is_ptr and not holds_ref:
517                     ret_conv = ("LDKTxOut* " + ty_info.var_name + "_ref = MALLOC(sizeof(LDKTxOut), \"LDKTxOut\");\n*" + ty_info.var_name + "_ref = ", ";")
518                 else:
519                     ret_conv = (self.consts.ptr_c_ty + " " + ty_info.var_name + "_ref = ((uintptr_t)&", ") | 1;")
520                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
521                     arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
522                     ret_conv = ret_conv, ret_conv_name = "(" + self.consts.ptr_c_ty + ")" + ty_info.var_name + "_ref",
523                     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 + ")") + ";",
524                     to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (self.consts.get_ptr(ty_info.var_name), ""))
525             elif ty_info.is_ptr:
526                 assert(not is_free)
527                 if ty_info.rust_obj in self.complex_enums:
528                     ret_conv = (self.consts.ptr_c_ty + " ret_" + ty_info.var_name + " = (uintptr_t)", " | 1; // WARNING: We should clone here!")
529                     from_hu_sfx = self.consts.add_ref("this", ty_info.var_name)
530                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
531                         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"
532                         ret_conv_pfx += "*ret_" + ty_info.var_name + " = " + ty_info.rust_obj.replace("LDK", "") + "_clone("
533                         ret_conv = (ret_conv_pfx, ");")
534                         from_hu_sfx = ""
535                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
536                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
537                         arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
538                         ret_conv = ret_conv, ret_conv_name = "(" + self.consts.ptr_c_ty + ")ret_" + ty_info.var_name,
539                         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 + ")") + ";",
540                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
541                         from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name) + " & ~1", from_hu_sfx))
542                 elif ty_info.rust_obj in self.trait_structs:
543                     if ty_info.nonnull_ptr:
544                         arg_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uintptr_t)" + ty_info.var_name + ") & ~1);\n"
545                         arg_conv += "if (!(" + ty_info.var_name + " & 1)) { CHECK_ACCESS(" + ty_info.var_name + "_ptr); }\n"
546                         arg_conv += ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
547                         arg_conv_name = ty_info.var_name + "_conv"
548                     else:
549                         # We map Option<Trait> as *mut Trait, which we can differentiate from &Trait by the NONNULL_PTR annotation.
550                         # We handle the Option<Trait> case here.
551                         arg_conv = ty_info.rust_obj + " *" + ty_info.var_name + "_conv_ptr = NULL;\n"
552                         arg_conv += "if (" + ty_info.var_name + " != 0) {\n"
553                         arg_conv += "\t" + ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
554                         arg_conv += "void* " + ty_info.var_name + "_ptr = (void*)(((uintptr_t)" + ty_info.var_name + ") & ~1);\n"
555                         arg_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
556                         arg_conv += "\t" + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
557                         arg_conv += self.consts.trait_struct_inc_refcnt(ty_info).replace("\n", "\n\t")
558                         arg_conv += "\n\t" + ty_info.var_name + "_conv_ptr = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n"
559                         arg_conv += "\t*" + ty_info.var_name + "_conv_ptr = " + ty_info.var_name + "_conv;\n"
560                         arg_conv += "}"
561                         arg_conv_name = ty_info.var_name + "_conv_ptr"
562                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
563                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
564                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
565                             ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_clone = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n" +
566                                 "*" + ty_info.var_name + "_clone = " + ty_info.rust_obj.replace("LDK", "") + "_clone(", ");"),
567                             ret_conv_name = "(" + self.consts.ptr_c_ty + ")" + ty_info.var_name + "_clone",
568                             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") + ";",
569                             to_hu_conv_name = "ret_hu_conv",
570                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name), ""))
571                     else:
572                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
573                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
574                             ret_conv = ("// WARNING: This object doesn't live past this scope, needs clone!\n" + self.consts.ptr_c_ty + " ret_" + ty_info.var_name + " = ((uintptr_t)", ") | 1;"),
575                             ret_conv_name = "ret_" + ty_info.var_name,
576                             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") + ";",
577                             to_hu_conv_name = "ret_hu_conv",
578                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name), self.consts.add_ref("this", ty_info.var_name)))
579                 ret_conv = (self.consts.ptr_c_ty + " ret_" + ty_info.var_name + " = (uintptr_t)", ";")
580                 if holds_ref:
581                     ret_conv = (ret_conv[0], " | 1;")
582                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
583                     arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)(" + ty_info.var_name + " & ~1);",
584                     arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
585                     ret_conv = ret_conv, ret_conv_name = "ret_" + ty_info.var_name,
586                     to_hu_conv = "TODO 3", to_hu_conv_name = None, from_hu_conv = None) # its a pointer, no conv needed
587             assert False # We should have handled every case by now.