Make array range iteration language-specific
[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                 from_hu_conv = None
51                 if not arr_len.isdigit():
52                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
53                     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"
54                     if (not ty_info.is_ptr or not holds_ref) and ty_info.rust_obj != "LDKu8slice":
55                         arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = MALLOC(" + arr_name + "_ref." + arr_len + ", \"" + ty_info.rust_obj + " Bytes\");\n"
56                         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) + ";"
57                     else:
58                         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) + ";"
59                         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)
60                     if ty_info.rust_obj == "LDKTransaction":
61                         arg_conv = arg_conv + "\n" + arr_name + "_ref.data_is_owned = " + str(holds_ref).lower() + ";"
62                     ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
63                     ret_conv = (ret_conv[0], ";\nint8_tArray " + arr_name + "_arr = " + self.consts.create_native_arr_call(arr_name + "_var." + arr_len, ty_info) + ";\n")
64                     (pfx, sfx) = self.consts.set_native_arr_contents(arr_name + "_arr", arr_name + "_var." + arr_len, ty_info)
65                     ret_conv = (ret_conv[0], ret_conv[1] + pfx + arr_name + "_var." + ty_info.arr_access + sfx + ";")
66                     if not holds_ref and ty_info.rust_obj != "LDKu8slice":
67                         ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
68                 elif ty_info.rust_obj is not None:
69                     arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
70                     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"
71                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_ref." + ty_info.arr_access, arr_len, ty_info, True) + ";"
72                     ret_conv = (ret_conv[0], "." + ty_info.arr_access + set_sfx + ";")
73                     from_hu_conv = ("InternalUtils.check_arr_len(" + arr_name + ", " + arr_len + ")", "")
74                 else:
75                     arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n"
76                     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"
77                     arg_conv = arg_conv + self.consts.get_native_arr_contents(arr_name, arr_name + "_arr", arr_len, ty_info, True) + ";\n"
78                     arg_conv = arg_conv + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
79                     ret_conv = (ret_conv[0] + "*", set_sfx + ";")
80                     from_hu_conv = ("InternalUtils.check_arr_len(" + arr_name + ", " + arr_len + ")", "")
81                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
82                     arg_conv = arg_conv, arg_conv_name = arr_name + "_ref", arg_conv_cleanup = arg_conv_cleanup,
83                     ret_conv = ret_conv, ret_conv_name = arr_name + "_arr", to_hu_conv = None, to_hu_conv_name = None,
84                     from_hu_conv = from_hu_conv)
85             else:
86                 assert not arr_len.isdigit() # fixed length arrays not implemented
87                 assert ty_info.java_ty[len(ty_info.java_ty) - 2:] == "[]"
88                 if arr_name == "":
89                     arr_name = "ret"
90                 conv_name = arr_name + "_conv_" + str(len(ty_info.java_hu_ty))
91                 idxc = chr(ord('a') + (len(ty_info.java_hu_ty) % 26))
92                 ty_info.subty.var_name = conv_name
93                 #XXX: We'd really prefer to only ever set to False, avoiding lots of clone, but need smarter free logic
94                 #if ty_info.is_ptr or holds_ref:
95                 #    ty_info.subty.requires_clone = False
96                 ty_info.subty.requires_clone = not ty_info.is_ptr or not holds_ref
97                 if not ty_info.subty.is_native_primitive and ty_info.subty.rust_obj == "LDKChannelMonitor":
98                     # We take a Vec of references to ChannelMonitors as input to ChannelManagerReadArgs, if we clone them,
99                     # we end up freeing the clones after creating the ChannelManagerReadArgs before calling the read
100                     # function itself, resulting in a segfault. Thus, we manually check and ensure we don't clone for
101                     # ChannelMonitors inside of vecs.
102                     ty_info.subty.requires_clone = False
103                 subty = self.map_type_with_info(ty_info.subty, False, None, is_free, holds_ref, False)
104                 arg_conv = ty_info.rust_obj + " " + arr_name + "_constr;\n"
105                 pf = ""
106                 if ty_info.is_ptr:
107                     pf = "\t"
108                     arg_conv += ty_info.rust_obj + " *" + arr_name + "_ptr = NULL;\n"
109                     arg_conv += "if (" + self.consts.is_arr_some_check[0] + arr_name + self.consts.is_arr_some_check[1] + ") {\n"
110                 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"
111                 arg_conv += pf + "if (" + arr_name + "_constr." + arr_len + " > 0)\n"
112                 if subty.is_native_primitive:
113                     szof = subty.c_ty
114                 else:
115                     szof = subty.rust_obj
116                 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"
117                 arg_conv += pf + "else\n"
118                 arg_conv += pf + "\t" + arr_name + "_constr." + ty_info.arr_access + " = NULL;\n"
119                 get_arr = self.consts.get_native_arr_contents(arr_name, "NO_DEST", arr_name + "_constr." + arr_len, ty_info, False)
120                 if get_arr != None:
121                     arg_conv += pf + subty.c_ty + "* " + arr_name + "_vals = " + get_arr + ";\n"
122                 arg_conv += pf + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_constr." + arr_len + "; " + idxc + "++) {\n"
123                 if get_arr != None:
124                     arg_conv += pf + "\t" + subty.c_ty + " " + conv_name + " = " + arr_name + "_vals[" + idxc + "];"
125                     if subty.arg_conv is not None:
126                         arg_conv += "\n\t" + pf + subty.arg_conv.replace("\n", "\n\t" + pf)
127                 else:
128                     arg_conv += pf + "\t" + subty.c_ty + " " + conv_name + " = " + self.consts.get_native_arr_elem(arr_name, idxc, ty_info) + ";\n"
129                     arg_conv += pf + "\t" + subty.arg_conv.replace("\n", "\n\t" + pf)
130                 arg_conv += "\n\t" + pf + arr_name + "_constr." + ty_info.arr_access + "[" + idxc + "] = " + subty.arg_conv_name + ";\n" + pf + "}"
131                 if get_arr != None:
132                     cleanup = self.consts.cleanup_native_arr_ref_contents(arr_name, arr_name + "_vals", arr_name + "_constr." + arr_len, ty_info)
133                     if cleanup is not None:
134                         arg_conv += "\n" + pf + cleanup + ";"
135                 if ty_info.is_ptr:
136                     arg_conv_name = arr_name + "_ptr"
137                 else:
138                     arg_conv_name = arr_name + "_constr"
139                 arg_conv_cleanup = None
140                 if ty_info.is_ptr:
141                     arg_conv_cleanup = "if (" + arr_name + "_ptr != NULL) { FREE(" + arr_name + "_constr." + ty_info.arr_access + "); }"
142                 if ty_info.is_ptr:
143                     arg_conv += "\n\t" + arr_name + "_ptr = &" + arr_name + "_constr;\n}"
144
145                 if is_nullable:
146                     ret_conv = (ty_info.rust_obj + " *" + arr_name + "_var_ptr = ", "")
147                 else:
148                     ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
149                 if subty.ret_conv is None:
150                     ret_conv = ("DUMMY", "DUMMY")
151                 else:
152                     ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = NULL;\n")
153                     indent = ""
154                     if is_nullable:
155                         ret_conv = (ret_conv[0], ret_conv[1] + "if (" + arr_name + " != NULL) {\n")
156                         ret_conv = (ret_conv[0], ret_conv[1] + "\t" + ty_info.rust_obj + " " + arr_name + "_var = *" + arr_name + "_var_ptr;\n")
157                         indent = "\t"
158                     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")
159                     get_ptr_call = self.consts.get_native_arr_ptr_call(ty_info)
160                     if get_ptr_call is not None:
161                         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")
162                     ret_conv = (ret_conv[0], ret_conv[1] + indent + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_var." + arr_len + "; " + idxc + "++) {\n")
163                     ret_conv = (ret_conv[0], ret_conv[1] + indent + "\t" + subty.ret_conv[0].replace("\n", "\n\t" + indent))
164                     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")
165                     if get_ptr_call is not None:
166                         ret_conv = (ret_conv[0], ret_conv[1] + indent + "\t" + arr_name + "_arr_ptr[" + idxc + "] = " + subty.ret_conv_name + ";\n" + indent + "}\n")
167                     else:
168                         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")
169                     cleanup = self.consts.release_native_arr_ptr_call(ty_info, arr_name + "_arr", arr_name + "_arr_ptr")
170                     if cleanup is not None:
171                         ret_conv = (ret_conv[0], ret_conv[1] + indent + cleanup + ";")
172                     if not holds_ref and not is_nullable:
173                         # XXX: The commented if's are a bit smarter freeing, but we need to be a nudge smarter still
174                         # Note that we don't drop the full vec here - we're passing ownership to java (or have cloned) or free'd by now!
175                         ret_conv = (ret_conv[0], ret_conv[1] + "\n" + indent + "FREE(" + arr_name + "_var." + ty_info.arr_access + ");")
176                         #if subty.rust_obj is not None and subty.rust_obj in self.opaque_structs:
177                         #    ret_conv = (ret_conv[0], ret_conv[1] + "\nFREE(" + arr_name + "_var." + ty_info.arr_access + ");")
178                         #else:
179                         #    ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
180                     if is_nullable:
181                         ret_conv = (ret_conv[0], ret_conv[1] + "\n}")
182
183                 to_hu_conv = None
184                 to_hu_conv_name = None
185                 if subty.to_hu_conv is not None:
186                     base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
187                     to_hu_conv = self.consts.var_decl_statement(ty_info.java_hu_ty, conv_name + "_arr", "new " + base_ty + "[" + arr_name + ".length]")
188                     if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
189                         # Do a bit of a dance to move any excess [] to the end
190                         to_hu_conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
191                     to_hu_conv += ";\n" + self.consts.for_n_in_range(idxc, "0", arr_name + ".length") + "\n"
192                     to_hu_conv += "\t" + self.consts.var_decl_statement(subty.java_ty, conv_name, arr_name + "[" + idxc + "]") + ";\n"
193                     to_hu_conv += "\t" + subty.to_hu_conv.replace("\n", "\n\t") + "\n"
194                     to_hu_conv += "\t" + conv_name + "_arr[" + idxc + "] = " + subty.to_hu_conv_name + ";\n}"
195                     to_hu_conv_name = conv_name + "_arr"
196                 from_hu_conv = None
197                 if subty.from_hu_conv is not None:
198                     hu_conv_b = ""
199                     if subty.from_hu_conv[1] != "":
200                         iterator = self.consts.for_n_in_arr(conv_name, arr_name, subty)
201                         hu_conv_b = iterator[0] + subty.from_hu_conv[1] + ";" + iterator[1]
202                     from_hu_conv = (self.consts.map_hu_array_elems(arr_name, conv_name, ty_info, subty), hu_conv_b)
203
204                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
205                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = arg_conv_cleanup,
206                     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)
207         elif ty_info.java_ty == "String":
208             assert not is_nullable
209             if not is_free:
210                 arg_conv = "LDKStr " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_c_call(ty_info.var_name) + ";"
211                 arg_conv_name = ty_info.var_name + "_conv"
212             else:
213                 arg_conv = "LDKStr dummy = { .chars = NULL, .len = 0, .chars_is_owned = false };"
214                 arg_conv_name = "dummy"
215             if ty_info.arr_access is None:
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 = None,
218                     ret_conv = ("const char* " + ty_info.var_name + "_str = ",
219                         ";\njstring " + ty_info.var_name + "_conv = " + self.consts.str_ref_to_native_call(ty_info.var_name + "_str", "strlen(" + ty_info.var_name + "_str)") + ";"),
220                     ret_conv_name = ty_info.var_name + "_conv",
221                     to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
222             else:
223                 free_str = ""
224                 if not holds_ref:
225                     free_str = "\nStr_free(" + ty_info.var_name + "_str);"
226                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
227                     arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
228                     ret_conv = ("LDKStr " + ty_info.var_name + "_str = ",
229                         ";\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),
230                     ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
231         elif ty_info.var_name == "" and not print_void:
232             # We don't have a parameter name, and want one, just call it arg
233             if not ty_info.is_native_primitive:
234                 assert(not is_free or ty_info.rust_obj not in self.opaque_structs)
235                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
236                     arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
237                     arg_conv_name = "arg_conv", arg_conv_cleanup = None,
238                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 7", to_hu_conv_name = None, from_hu_conv = None)
239             else:
240                 assert(not is_free)
241                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
242                     arg_conv = None, arg_conv_name = "arg", arg_conv_cleanup = None,
243                     ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 8", to_hu_conv_name = None, from_hu_conv = None)
244         elif ty_info.is_native_primitive:
245             assert not is_nullable
246             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
247                 arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None,
248                 ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
249         else:
250             if ty_info.var_name == "":
251                 ty_info.var_name = "ret"
252
253             if ty_info.rust_obj in self.opaque_structs:
254                 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))
255                 opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
256                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
257                 if ty_info.is_ptr and holds_ref:
258                     opaque_arg_conv += ty_info.var_name + "_conv.is_owned = false;\n"
259                 else:
260                     opaque_arg_conv += ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);\n"
261                 opaque_arg_conv += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_conv);"
262                 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:
263                     if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
264                         # 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.
265                         # arg_conv is used when converting a function argument from java normally (with holds_ref set),
266                         # and when converting a java value being returned from a trait method (with holds_ref unset).
267                         # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
268                         # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
269                         if holds_ref:
270                             opaque_arg_conv = opaque_arg_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
271                             from_hu_conv = (from_hu_conv[0], "")
272                         else:
273                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".clone_ptr()", "")
274                     elif ty_info.passed_as_ptr:
275                         opaque_arg_conv = opaque_arg_conv + "\n// Warning: we need a move here but no clone is available for " + ty_info.rust_obj
276                         # TODO: Once we support features cloning (which just isn't in C yet), we can make this a compile error instead!
277                         from_hu_conv = (from_hu_conv[0], from_hu_conv[1] + ";\n" +
278                             "// Due to rust's strict-ownership memory model, in some cases we need to \"move\"\n" +
279                             "// an object to pass exclusive ownership to the function being called.\n" +
280                             "// In most cases, we avoid this being visible in GC'd languages by cloning the object\n" +
281                             "// at the FFI layer, creating a new object which Rust can claim ownership of\n" +
282                             "// However, in some cases (eg here), there is no way to clone an object, and thus\n" +
283                             "// we actually have to pass full ownership to Rust.\n" +
284                             "// 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))
285
286                 opaque_ret_conv_suf = ";\n"
287                 opaque_ret_conv_suf += "uint64_t " + ty_info.var_name + "_ref = 0;\n"
288                 indent = ""
289                 if is_nullable:
290                     opaque_ret_conv_suf += "if ((uint64_t)" + ty_info.var_name + "_var.inner > 4096) {\n"
291                     indent = "\t"
292                 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
293                     opaque_ret_conv_suf += indent + ty_info.var_name + "_var = " + ty_info.rust_obj.replace("LDK", "") + "_clone(" + ty_info.var_name + ");\n"
294                 elif not holds_ref and ty_info.is_ptr:
295                     opaque_ret_conv_suf += indent + "// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
296
297                 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"
298                 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"
299                 opaque_ret_conv_suf += "CHECK_INNER_FIELD_ACCESS_OR_NULL(" + ty_info.var_name + "_var);\n"
300                 if holds_ref:
301                     opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_var.inner & ~1;"
302                 else:
303                     opaque_ret_conv_suf += indent + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_var.inner;\n"
304                     opaque_ret_conv_suf += indent + "if (" + ty_info.var_name + "_var.is_owned) {\n"
305                     opaque_ret_conv_suf += indent + "\t" + ty_info.var_name + "_ref |= 1;\n"
306                     opaque_ret_conv_suf += indent + "}"
307                 if is_nullable:
308                     opaque_ret_conv_suf += "\n}"
309
310                 to_hu_conv_sfx = ""
311                 if not ty_info.is_ptr or holds_ref:
312                     to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
313                 if ty_info.is_ptr:
314                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
315                         arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
316                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = *", opaque_ret_conv_suf),
317                         ret_conv_name = ty_info.var_name + "_ref",
318                         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,
319                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
320                         from_hu_conv = from_hu_conv)
321                 else:
322                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
323                         arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
324                         ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", opaque_ret_conv_suf),
325                         ret_conv_name = ty_info.var_name + "_ref",
326                         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,
327                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
328                         from_hu_conv = from_hu_conv)
329
330             assert not is_nullable
331             if not ty_info.is_ptr:
332                 if ty_info.rust_obj in self.unitary_enums:
333                     (ret_pfx, ret_sfx) = self.consts.c_unitary_enum_to_native_call(ty_info)
334                     (arg_pfx, arg_sfx) = self.consts.native_unitary_enum_to_c_call(ty_info)
335                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
336                         arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + arg_pfx + ty_info.var_name + arg_sfx + ";",
337                         arg_conv_name = ty_info.var_name + "_conv",
338                         arg_conv_cleanup = None,
339                         ret_conv = (ty_info.c_ty + " " + ty_info.var_name + "_conv = " + ret_pfx, ret_sfx + ";"),
340                         ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
341                 base_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
342                 base_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
343                 base_conv += ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)(" + ty_info.var_name + "_ptr);"
344                 from_hu_conv = None
345                 if ty_info.rust_obj in self.trait_structs:
346                     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 = ", ";")
347                     if holds_ref:
348                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
349                             ret_conv = (ret_conv[0] + ty_info.rust_obj.replace("LDK", "") + "_clone(&", ");")
350                         else:
351                             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")
352                             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)"))
353                     if not is_free:
354                         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
355                         if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") in self.clone_fns:
356                             # arg_conv is used when converting a function argument from java normally (with holds_ref set),
357                             # and when converting a java value being returned from a trait method (with holds_ref unset).
358                             # In the second case, we need to clone before returning to C (as once we return the GC can free the object),
359                             # whereas in the first we prefer to clone in C to avoid additional Java code as much as possible.
360                             if holds_ref:
361                                 base_conv += "\n" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
362                             else:
363                                 from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".clone_ptr()", "")
364                                 base_conv += "\n" + "FREE((void*)" + ty_info.var_name + ");"
365                         else:
366                             base_conv = base_conv + self.consts.trait_struct_inc_refcnt(ty_info)
367                             if needs_full_clone:
368                                 base_conv = base_conv + "// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj + "\n"
369                     else:
370                         base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
371                     if from_hu_conv is None:
372                         from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name), "")
373                     from_hu_conv = (from_hu_conv[0], self.consts.add_ref("this", ty_info.var_name))
374                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
375                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
376                         ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_ret",
377                         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") + ";",
378                         to_hu_conv_name = "ret_hu_conv", from_hu_conv = from_hu_conv)
379                 needs_full_clone = not is_free and (not ty_info.is_ptr or ty_info.requires_clone == True) and ty_info.requires_clone != False
380                 if needs_full_clone:
381                     if "res" in ty_info.var_name: # XXX: This is a stupid hack
382                         needs_full_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.rust_obj + "*)(((uint64_t)" + ty_info.var_name + ") & ~1));"
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                     elif needs_full_clone:
394                         base_conv = base_conv + "\n// Warning: we may need a move here but no clone is available for " + ty_info.rust_obj
395                 if not needs_full_clone and ty_info.rust_obj != "LDKu8slice" and (not holds_ref or is_free):
396                     # Don't bother free'ing slices passed in - Rust doesn't auto-free the
397                     # underlying unlike Vecs, and it gives Java more freedom.
398                     base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");"
399                 if ty_info.rust_obj in self.complex_enums:
400                     to_hu_conv_sfx = ""
401                     if needs_full_clone and (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
402                         # We really need a full clone here, but for now we just implement
403                         # a manual clone explicitly for Option<Trait>s
404                         if ty_info.contains_trait:
405                             assert ty_info.rust_obj.startswith("LDKCOption") # We don't support contained traits for anything else yet
406                             optional_ty = ty_info.rust_obj[11:-1]
407                             assert "LDK" + optional_ty in self.trait_structs # We don't support contained traits for anything else yet
408                             to_hu_conv_sfx = self.consts.add_ref("this", ty_info.var_name)
409                             base_conv += "\nif (" + ty_info.var_name + "_conv.tag == " + ty_info.rust_obj + "_Some) {"
410                             base_conv += "\n\t// Manually implement clone for Java trait instances"
411                             optional_ty_info = self.java_c_types("LDK" + optional_ty + " " + ty_info.var_name, None)
412                             base_conv += self.consts.trait_struct_inc_refcnt(optional_ty_info).\
413                                 replace("\n", "\n\t").replace(ty_info.var_name + "_conv", ty_info.var_name + "_conv.some")
414                             base_conv += "\n}"
415                     ret_conv = ("uint64_t " + ty_info.var_name + "_ref = ((uint64_t)&", ") | 1;")
416                     if not holds_ref:
417                         ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_copy = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n", "")
418                         ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = ", "")
419                         ret_conv = (ret_conv[0], ";\nuint64_t " + ty_info.var_name + "_ref = (uint64_t)" + ty_info.var_name + "_copy;")
420                     if from_hu_conv is None:
421                         from_hu_conv = (self.consts.get_ptr(ty_info.var_name), "")
422                     from_hu_conv = (from_hu_conv[0], to_hu_conv_sfx)
423                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
424                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
425                         ret_conv = ret_conv, ret_conv_name = ty_info.var_name + "_ref",
426                         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 + ")") + ";\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";",
427                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
428                 if ty_info.rust_obj in self.result_types:
429                     if holds_ref:
430                         # If we're trying to return a ref, we have to clone.
431                         # We just blindly assume its implemented and let the compiler fail if its not.
432                         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 = ", ";")
433                         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);")
434                     else:
435                         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 = ", ";")
436                     if from_hu_conv is None:
437                         from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : 0", "")
438                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
439                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
440                         ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_conv",
441                         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 + ")") + ";",
442                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
443                 if ty_info.rust_obj in self.tuple_types:
444                     ret_conv_name = "((uint64_t)" + ty_info.var_name + "_conv)"
445                     if holds_ref:
446                         # If we're trying to return a ref, we have to clone.
447                         if (ty_info.rust_obj.replace("LDK", "") + "_clone") not in self.clone_fns:
448                             ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = &", "")
449                             ret_conv = (ret_conv[0], ";\n// Warning: we really need to clone here, but no clone is available for " + ty_info.rust_obj)
450                             ret_conv_name += " | 1"
451                         else:
452                             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 = ", ";")
453                             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);")
454                     else:
455                         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 = ", ";")
456                     if not ty_info.is_ptr or holds_ref:
457                         to_hu_conv_sfx = "\n" + self.consts.add_ref(ty_info.var_name + "_hu_conv", "this") + ";"
458                     else:
459                         to_hu_conv_sfx = ""
460                     if from_hu_conv is None:
461                         from_hu_conv = (ty_info.var_name + " != null ? " + self.consts.get_ptr(ty_info.var_name) + " : 0", "")
462                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
463                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
464                         ret_conv = ret_conv, ret_conv_name = ret_conv_name,
465                         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,
466                         to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = from_hu_conv)
467
468                 # The manually-defined types - TxOut and u5
469                 if ty_info.rust_obj == "LDKu5":
470                     assert from_hu_conv is None
471                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
472                         arg_conv = "", arg_conv_name = "(LDKu5){ ._0 = " + ty_info.var_name + " }", arg_conv_cleanup = None,
473                         ret_conv = ("uint8_t " + ty_info.var_name + "_val = ", "._0;"), ret_conv_name = ty_info.var_name + "_val",
474                         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 + ")") + ";",
475                         to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".getVal()", ""))
476
477                 assert ty_info.rust_obj == "LDKTxOut"
478                 if not ty_info.is_ptr and not holds_ref:
479                     ret_conv = ("LDKTxOut* " + ty_info.var_name + "_ref = MALLOC(sizeof(LDKTxOut), \"LDKTxOut\");\n*" + ty_info.var_name + "_ref = ", ";")
480                 else:
481                     ret_conv = ("uint64_t " + ty_info.var_name + "_ref = ((uint64_t)&", ") | 1;")
482                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
483                     arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
484                     ret_conv = ret_conv, ret_conv_name = "(uint64_t)" + ty_info.var_name + "_ref",
485                     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 + ")") + ";",
486                     to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (self.consts.get_ptr(ty_info.var_name), ""))
487             elif ty_info.is_ptr:
488                 assert(not is_free)
489                 if ty_info.rust_obj in self.complex_enums:
490                     ret_conv = ("uint64_t ret_" + ty_info.var_name + " = (uint64_t)", " | 1; // Warning: We should clone here!")
491                     from_hu_sfx = self.consts.add_ref("this", ty_info.var_name)
492                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
493                         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"
494                         ret_conv_pfx += "*ret_" + ty_info.var_name + " = " + ty_info.rust_obj.replace("LDK", "") + "_clone("
495                         ret_conv = (ret_conv_pfx, ");")
496                         from_hu_sfx = ""
497                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
498                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
499                         arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
500                         ret_conv = ret_conv, ret_conv_name = "(uint64_t)ret_" + ty_info.var_name,
501                         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 + ")") + ";",
502                         to_hu_conv_name = ty_info.var_name + "_hu_conv",
503                         from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name) + " & ~1", from_hu_sfx))
504                 elif ty_info.rust_obj in self.trait_structs:
505                     if ty_info.nonnull_ptr:
506                         arg_conv = "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
507                         arg_conv += "if (!(" + ty_info.var_name + " & 1)) { CHECK_ACCESS(" + ty_info.var_name + "_ptr); }\n"
508                         arg_conv += ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
509                         arg_conv_name = ty_info.var_name + "_conv"
510                     else:
511                         # We map Option<Trait> as *mut Trait, which we can differentiate from &Trait by the NONNULL_PTR annotation.
512                         # We handle the Option<Trait> case here.
513                         arg_conv = ty_info.rust_obj + " *" + ty_info.var_name + "_conv_ptr = NULL;\n"
514                         arg_conv += "if (" + ty_info.var_name + " != 0) {\n"
515                         arg_conv += "\t" + ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
516                         arg_conv += "void* " + ty_info.var_name + "_ptr = (void*)(((uint64_t)" + ty_info.var_name + ") & ~1);\n"
517                         arg_conv += "CHECK_ACCESS(" + ty_info.var_name + "_ptr);\n"
518                         arg_conv += "\t" + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + "_ptr;"
519                         arg_conv += self.consts.trait_struct_inc_refcnt(ty_info).replace("\n", "\n\t")
520                         arg_conv += "\n\t" + ty_info.var_name + "_conv_ptr = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n"
521                         arg_conv += "\t*" + ty_info.var_name + "_conv_ptr = " + ty_info.var_name + "_conv;\n"
522                         arg_conv += "}"
523                         arg_conv_name = ty_info.var_name + "_conv_ptr"
524                     if ty_info.rust_obj.replace("LDK", "") + "_clone" in self.clone_fns:
525                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
526                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
527                             ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_clone = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n" +
528                                 "*" + ty_info.var_name + "_clone = " + ty_info.rust_obj.replace("LDK", "") + "_clone(", ");"),
529                             ret_conv_name = "(uint64_t)" + ty_info.var_name + "_clone",
530                             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") + ";",
531                             to_hu_conv_name = "ret_hu_conv",
532                             from_hu_conv = (ty_info.var_name + " == null ? 0 : " + self.consts.get_ptr(ty_info.var_name), ""))
533                     else:
534                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
535                             arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = None,
536                             ret_conv = ("// WARNING: This object doesn't live past this scope, needs clone!\nuint64_t ret_" + ty_info.var_name + " = ((uint64_t)", ") | 1;"),
537                             ret_conv_name = "ret_" + ty_info.var_name,
538                             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") + ";",
539                             to_hu_conv_name = "ret_hu_conv",
540                             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)))
541                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
542                     arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)(" + ty_info.var_name + " & ~1);",
543                     arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
544                     ret_conv = ("uint64_t ret_" + ty_info.var_name + " = (uint64_t)", ";"), ret_conv_name = "ret_" + ty_info.var_name,
545                     to_hu_conv = "TODO 3", to_hu_conv_name = None, from_hu_conv = None) # its a pointer, no conv needed
546             assert False # We should have handled every case by now.