Provide human versions of trait interfaces, with a bunch of fixes to make it work

[ldk-java] / genbindings.py

diff --git a/genbindings.py b/genbindings.py
index 5ba69e6d09082e262f02ad5889b4fc96e0f234c9..b09d930b4e03992063e579c32f094dc7936c7b3e 100755 (executable)
--- a/genbindings.py
+++ b/genbindings.py
@@ -6,10 +6,22 @@ if len(sys.argv) != 6:
     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 
     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 

+hu_struct_file_prefix = """package org.ldk.structs;
+
+import org.ldk.impl.bindings;
+import org.ldk.enums.*;
+import org.ldk.util.*;
+import java.util.Arrays;
+
+@SuppressWarnings("unchecked") // We correctly assign various generic arrays
+"""
+

 class TypeInfo:
 class TypeInfo:

-    def __init__(self, rust_obj, java_ty, java_fn_ty_arg, c_ty, passed_as_ptr, is_ptr, var_name, arr_len, arr_access):
+    def __init__(self, is_native_primitive, rust_obj, java_ty, java_fn_ty_arg, java_hu_ty, c_ty, passed_as_ptr, is_ptr, var_name, arr_len, arr_access, subty=None):
+        self.is_native_primitive = is_native_primitive

         self.rust_obj = rust_obj
         self.java_ty = java_ty
         self.rust_obj = rust_obj
         self.java_ty = java_ty

+        self.java_hu_ty = java_hu_ty

         self.java_fn_ty_arg = java_fn_ty_arg
         self.c_ty = c_ty
         self.passed_as_ptr = passed_as_ptr
         self.java_fn_ty_arg = java_fn_ty_arg
         self.c_ty = c_ty
         self.passed_as_ptr = passed_as_ptr


@@ -17,9 +29,11 @@ class TypeInfo:
         self.var_name = var_name
         self.arr_len = arr_len
         self.arr_access = arr_access
         self.var_name = var_name
         self.arr_len = arr_len
         self.arr_access = arr_access

+        self.subty = subty
+        self.pass_by_ref = is_ptr

 
 class ConvInfo:
 
 class ConvInfo:

-    def __init__(self, ty_info, arg_name, arg_conv, arg_conv_name, ret_conv, ret_conv_name):
+    def __init__(self, ty_info, arg_name, arg_conv, arg_conv_name, arg_conv_cleanup, ret_conv, ret_conv_name, to_hu_conv, to_hu_conv_name, from_hu_conv):

         assert(ty_info.c_ty is not None)
         assert(ty_info.java_ty is not None)
         assert(arg_name is not None)
         assert(ty_info.c_ty is not None)
         assert(ty_info.java_ty is not None)
         assert(arg_name is not None)


@@ -27,12 +41,17 @@ class ConvInfo:
         self.rust_obj = ty_info.rust_obj
         self.c_ty = ty_info.c_ty
         self.java_ty = ty_info.java_ty
         self.rust_obj = ty_info.rust_obj
         self.c_ty = ty_info.c_ty
         self.java_ty = ty_info.java_ty

+        self.java_hu_ty = ty_info.java_hu_ty

         self.java_fn_ty_arg = ty_info.java_fn_ty_arg
         self.arg_name = arg_name
         self.arg_conv = arg_conv
         self.arg_conv_name = arg_conv_name
         self.java_fn_ty_arg = ty_info.java_fn_ty_arg
         self.arg_name = arg_name
         self.arg_conv = arg_conv
         self.arg_conv_name = arg_conv_name

+        self.arg_conv_cleanup = arg_conv_cleanup

         self.ret_conv = ret_conv
         self.ret_conv_name = ret_conv_name
         self.ret_conv = ret_conv
         self.ret_conv_name = ret_conv_name

+        self.to_hu_conv = to_hu_conv
+        self.to_hu_conv_name = to_hu_conv_name
+        self.from_hu_conv = from_hu_conv

 
     def print_ty(self):
         out_c.write(self.c_ty)
 
     def print_ty(self):
         out_c.write(self.c_ty)


@@ -45,169 +64,317 @@ class ConvInfo:
         else:
             out_java.write(" arg")
             out_c.write(" arg")
         else:
             out_java.write(" arg")
             out_c.write(" arg")

+
+def camel_to_snake(s):
+    # Convert camel case to snake case, in a way that appears to match cbindgen
+    con = "_"
+    ret = ""
+    lastchar = ""
+    lastund = False
+    for char in s:
+        if lastchar.isupper():
+            if not char.isupper() and not lastund:
+                ret = ret + "_"
+                lastund = True
+            else:
+                lastund = False
+            ret = ret + lastchar.lower()
+        else:
+            ret = ret + lastchar
+            if char.isupper() and not lastund:
+                ret = ret + "_"
+                lastund = True
+            else:
+                lastund = False
+        lastchar = char
+        if char.isnumeric():
+            lastund = True
+    return (ret + lastchar.lower()).strip("_")
+
+unitary_enums = set()
+complex_enums = set()
+opaque_structs = set()
+trait_structs = set()
+result_types = set()
+tuple_types = {}
+
+def is_common_base_ext(struct_name):
+    return struct_name in complex_enums or struct_name in opaque_structs or struct_name in trait_structs or struct_name in result_types
+
+var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([a-z0-9]*)\]")
+var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
+java_c_types_none_allowed = True # Unset when we do the real pass that populates the above sets
+def java_c_types(fn_arg, ret_arr_len):
+    fn_arg = fn_arg.strip()
+    if fn_arg.startswith("MUST_USE_RES "):
+        fn_arg = fn_arg[13:]
+    is_const = False
+    if fn_arg.startswith("const "):
+        fn_arg = fn_arg[6:]
+        is_const = True
+
+    is_ptr = False
+    take_by_ptr = False
+    rust_obj = None
+    arr_access = None
+    java_hu_ty = None
+    if fn_arg.startswith("LDKThirtyTwoBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[18:] + ")[32]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKThirtyTwoBytes"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKPublicKey"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[33]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKPublicKey"
+        arr_access = "compressed_form"
+    elif fn_arg.startswith("LDKSecretKey"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[32]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKSecretKey"
+        arr_access = "bytes"
+    elif fn_arg.startswith("LDKSignature"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[64]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKSignature"
+        arr_access = "compact_form"
+    elif fn_arg.startswith("LDKThreeBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[14:] + ")[3]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKThreeBytes"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKFourBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[4]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKFourBytes"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKSixteenBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[16:] + ")[16]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKSixteenBytes"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKTenBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[12:] + ")[10]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKTenBytes"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKu8slice"):
+        fn_arg = "uint8_t (*" + fn_arg[11:] + ")[datalen]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKu8slice"
+        arr_access = "data"
+    elif fn_arg.startswith("LDKCVecTempl_u8") or fn_arg.startswith("LDKCVec_u8Z"):
+        if fn_arg.startswith("LDKCVecTempl_u8"):
+            fn_arg = "uint8_t (*" + fn_arg[16:] + ")[datalen]"
+            rust_obj = "LDKCVecTempl_u8"
+            assert var_is_arr_regex.match(fn_arg[8:])
+        else:
+            fn_arg = "uint8_t (*" + fn_arg[12:] + ")[datalen]"
+            rust_obj = "LDKCVec_u8Z"
+            assert var_is_arr_regex.match(fn_arg[8:])
+        arr_access = "data"
+    elif fn_arg.startswith("LDKCVecTempl_") or fn_arg.startswith("LDKCVec_"):
+        is_ptr = False
+        if "*" in fn_arg:
+            fn_arg = fn_arg.replace("*", "")
+            is_ptr = True
+
+        if fn_arg.startswith("LDKCVec_"):
+            tyn = fn_arg[8:].split(" ")
+            assert tyn[0].endswith("Z")
+            if tyn[0] == "u64Z":
+                new_arg = "uint64_t"
+            else:
+                new_arg = "LDK" + tyn[0][:-1]
+            for a in tyn[1:]:
+                new_arg = new_arg + " " + a
+            res = java_c_types(new_arg, ret_arr_len)
+        else:
+            res = java_c_types("LDK" + fn_arg[13:], ret_arr_len)
+        if res is None:
+            assert java_c_types_none_allowed
+            return None
+        if is_ptr:
+            res.pass_by_ref = True
+        if res.is_native_primitive or res.passed_as_ptr:
+            return TypeInfo(rust_obj=fn_arg.split(" ")[0], java_ty=res.java_ty + "[]", java_hu_ty=res.java_hu_ty + "[]",
+                java_fn_ty_arg="[" + res.java_fn_ty_arg, c_ty=res.c_ty + "Array", passed_as_ptr=False, is_ptr=is_ptr,
+                var_name=res.var_name, arr_len="datalen", arr_access="data", subty=res, is_native_primitive=False)
+        else:
+            return TypeInfo(rust_obj=fn_arg.split(" ")[0], java_ty=res.java_ty + "[]", java_hu_ty=res.java_hu_ty + "[]",
+                java_fn_ty_arg="[" + res.java_fn_ty_arg, c_ty="jobjectArray", passed_as_ptr=False, is_ptr=is_ptr,
+                var_name=res.var_name, arr_len="datalen", arr_access="data", subty=res, is_native_primitive=False)
+
+    is_primitive = False
+    arr_len = None
+    if fn_arg.startswith("void"):
+        java_ty = "void"
+        c_ty = "void"
+        fn_ty_arg = "V"
+        fn_arg = fn_arg[4:].strip()
+        is_primitive = True
+    elif fn_arg.startswith("bool"):
+        java_ty = "boolean"
+        c_ty = "jboolean"
+        fn_ty_arg = "Z"
+        fn_arg = fn_arg[4:].strip()
+        is_primitive = True
+    elif fn_arg.startswith("uint8_t"):
+        java_ty = "byte"
+        c_ty = "jbyte"
+        fn_ty_arg = "B"
+        fn_arg = fn_arg[7:].strip()
+        is_primitive = True
+    elif fn_arg.startswith("uint16_t"):
+        java_ty = "short"
+        c_ty = "jshort"
+        fn_ty_arg = "S"
+        fn_arg = fn_arg[8:].strip()
+        is_primitive = True
+    elif fn_arg.startswith("uint32_t"):
+        java_ty = "int"
+        c_ty = "jint"
+        fn_ty_arg = "I"
+        fn_arg = fn_arg[8:].strip()
+        is_primitive = True
+    elif fn_arg.startswith("uint64_t") or fn_arg.startswith("uintptr_t"):
+        java_ty = "long"
+        c_ty = "jlong"
+        fn_ty_arg = "J"
+        if fn_arg.startswith("uint64_t"):
+            fn_arg = fn_arg[8:].strip()
+        else:
+            fn_arg = fn_arg[9:].strip()
+        is_primitive = True
+    elif is_const and fn_arg.startswith("char *"):
+        java_ty = "String"
+        c_ty = "const char*"
+        fn_ty_arg = "Ljava/lang/String;"
+        fn_arg = fn_arg[6:].strip()
+    elif fn_arg.startswith("LDKStr"):
+        java_ty = "String"
+        c_ty = "jstring"
+        fn_ty_arg = "Ljava/lang/String;"
+        fn_arg = fn_arg[6:].strip()
+        arr_access = "chars"
+        arr_len = "len"
+    else:
+        ma = var_ty_regex.match(fn_arg)
+        if ma.group(1).strip() in unitary_enums:
+            java_ty = ma.group(1).strip()
+            c_ty = "jclass"
+            fn_ty_arg = "Lorg/ldk/enums/" + ma.group(1).strip() + ";"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+        elif ma.group(1).strip().startswith("LDKC2Tuple"):
+            java_ty = "long"
+            java_hu_ty = "TwoTuple<"
+            if not ma.group(1).strip() in tuple_types:
+                assert java_c_types_none_allowed
+                return None
+            for idx, ty_info in enumerate(tuple_types[ma.group(1).strip()][0]):
+                if idx != 0:
+                    java_hu_ty = java_hu_ty + ", "
+                if ty_info.is_native_primitive:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty.title() # If we're a primitive, capitalize the first letter
+                else:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty
+            java_hu_ty = java_hu_ty + ">"
+            c_ty = "jlong"
+            fn_ty_arg = "J"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+        elif ma.group(1).strip().startswith("LDKC3Tuple"):
+            java_ty = "long"
+            java_hu_ty = "ThreeTuple<"
+            if not ma.group(1).strip() in tuple_types:
+                assert java_c_types_none_allowed
+                return None
+            for idx, ty_info in enumerate(tuple_types[ma.group(1).strip()][0]):
+                if idx != 0:
+                    java_hu_ty = java_hu_ty + ", "
+                if ty_info.is_native_primitive:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty.title() # If we're a primitive, capitalize the first letter
+                else:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty
+            java_hu_ty = java_hu_ty + ">"
+            c_ty = "jlong"
+            fn_ty_arg = "J"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+        else:
+            java_ty = "long"
+            java_hu_ty = ma.group(1).strip().replace("LDKCResult", "Result").replace("LDK", "")
+            c_ty = "jlong"
+            fn_ty_arg = "J"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+
+    if fn_arg.startswith(" *") or fn_arg.startswith("*"):
+        fn_arg = fn_arg.replace("*", "").strip()
+        is_ptr = True
+        c_ty = "jlong"
+        java_ty = "long"
+        fn_ty_arg = "J"
+        is_primitive = False
+
+    var_is_arr = var_is_arr_regex.match(fn_arg)
+    if var_is_arr is not None or ret_arr_len is not None:
+        assert(not take_by_ptr)
+        assert(not is_ptr)
+        java_ty = java_ty + "[]"
+        c_ty = c_ty + "Array"
+        if var_is_arr is not None:
+            if var_is_arr.group(1) == "":
+                return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                    passed_as_ptr=False, is_ptr=False, var_name="arg", arr_len=var_is_arr.group(2), arr_access=arr_access, is_native_primitive=False)
+            return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2), arr_access=arr_access, is_native_primitive=False)
+
+    if java_hu_ty is None:
+        java_hu_ty = java_ty
+    return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_hu_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
+        is_ptr=is_ptr, var_name=fn_arg, arr_len=arr_len, arr_access=arr_access, is_native_primitive=is_primitive)
+

 fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
 fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
 reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
 clone_fns = set()
 fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
 fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
 reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
 clone_fns = set()

+constructor_fns = {}

 with open(sys.argv[1]) as in_h:
     for line in in_h:
         reg_fn = reg_fn_regex.match(line)
         if reg_fn is not None:
             if reg_fn.group(2).endswith("_clone"):
                 clone_fns.add(reg_fn.group(2))
 with open(sys.argv[1]) as in_h:
     for line in in_h:
         reg_fn = reg_fn_regex.match(line)
         if reg_fn is not None:
             if reg_fn.group(2).endswith("_clone"):
                 clone_fns.add(reg_fn.group(2))

+            else:
+                rty = java_c_types(reg_fn.group(1), None)
+                if rty is not None and rty.rust_obj is not None and reg_fn.group(2) == rty.java_hu_ty + "_new":
+                    constructor_fns[rty.rust_obj] = reg_fn.group(3)

             continue
         arr_fn = fn_ret_arr_regex.match(line)
         if arr_fn is not None:
             if arr_fn.group(2).endswith("_clone"):
                 clone_fns.add(arr_fn.group(2))
             continue
         arr_fn = fn_ret_arr_regex.match(line)
         if arr_fn is not None:
             if arr_fn.group(2).endswith("_clone"):
                 clone_fns.add(arr_fn.group(2))

+            # No object constructors return arrays, as then they wouldn't be an object constructor

             continue
             continue

+java_c_types_none_allowed = False # C structs created by cbindgen are declared in dependency order

 
 with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[4], "w") as out_c:
 
 with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[4], "w") as out_c:

-    opaque_structs = set()
-    trait_structs = set()
-    unitary_enums = set()
-
-    def camel_to_snake(s):
-        # Convert camel case to snake case, in a way that appears to match cbindgen
-        con = "_"
-        ret = ""
-        lastchar = ""
-        lastund = False
-        for char in s:
-            if lastchar.isupper():
-                if not char.isupper() and not lastund:
-                    ret = ret + "_"
-                    lastund = True
-                else:
-                    lastund = False
-                ret = ret + lastchar.lower()
-            else:
-                ret = ret + lastchar
-                if char.isupper() and not lastund:
-                    ret = ret + "_"
-                    lastund = True
-                else:
-                    lastund = False
-            lastchar = char
-            if char.isnumeric():
-                lastund = True
-        return (ret + lastchar.lower()).strip("_")
-
-    var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([0-9]*)\]")
-    var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
-    def java_c_types(fn_arg, ret_arr_len):
-        fn_arg = fn_arg.strip()
-        if fn_arg.startswith("MUST_USE_RES "):
-            fn_arg = fn_arg[13:]
-        is_const = False
-        if fn_arg.startswith("const "):
-            fn_arg = fn_arg[6:]
-            is_const = True
-
-        is_ptr = False
-        take_by_ptr = False
-        rust_obj = None
-        arr_access = None
-        if fn_arg.startswith("LDKThirtyTwoBytes"):
-            fn_arg = "uint8_t (*" + fn_arg[18:] + ")[32]"
-            assert var_is_arr_regex.match(fn_arg[8:])
-            rust_obj = "LDKThirtyTwoBytes"
-            arr_access = "data"
-        if fn_arg.startswith("LDKPublicKey"):
-            fn_arg = "uint8_t (*" + fn_arg[13:] + ")[33]"
-            assert var_is_arr_regex.match(fn_arg[8:])
-            rust_obj = "LDKPublicKey"
-            arr_access = "compressed_form"
-        #if fn_arg.startswith("LDKSignature"):
-        #    fn_arg = "uint8_t (*" + fn_arg[13:] + ")[64]"
-        #    assert var_is_arr_regex.match(fn_arg[8:])
-        #    rust_obj = "LDKSignature"
-
-        if fn_arg.startswith("void"):
-            java_ty = "void"
-            c_ty = "void"
-            fn_ty_arg = "V"
-            fn_arg = fn_arg[4:].strip()
-        elif fn_arg.startswith("bool"):
-            java_ty = "boolean"
-            c_ty = "jboolean"
-            fn_ty_arg = "Z"
-            fn_arg = fn_arg[4:].strip()
-        elif fn_arg.startswith("uint8_t"):
-            java_ty = "byte"
-            c_ty = "jbyte"
-            fn_ty_arg = "B"
-            fn_arg = fn_arg[7:].strip()
-        elif fn_arg.startswith("uint16_t"):
-            java_ty = "short"
-            c_ty = "jshort"
-            fn_ty_arg = "S"
-            fn_arg = fn_arg[8:].strip()
-        elif fn_arg.startswith("uint32_t"):
-            java_ty = "int"
-            c_ty = "jint"
-            fn_ty_arg = "I"
-            fn_arg = fn_arg[8:].strip()
-        elif fn_arg.startswith("uint64_t") or fn_arg.startswith("uintptr_t"):
-            java_ty = "long"
-            c_ty = "jlong"
-            fn_ty_arg = "J"
-            if fn_arg.startswith("uint64_t"):
-                fn_arg = fn_arg[8:].strip()
-            else:
-                fn_arg = fn_arg[9:].strip()
-        elif is_const and fn_arg.startswith("char *"):
-            java_ty = "String"
-            c_ty = "const char*"
-            fn_ty_arg = "Ljava/lang/String;"
-            fn_arg = fn_arg[6:].strip()
-        else:
-            ma = var_ty_regex.match(fn_arg)
-            if ma.group(1).strip() in unitary_enums:
-                java_ty = ma.group(1).strip()
-                c_ty = "jclass"
-                fn_ty_arg = "Lorg/ldk/enums/" + ma.group(1).strip() + ";"
-                fn_arg = ma.group(2).strip()
-                rust_obj = ma.group(1).strip()
-                take_by_ptr = True
-            else:
-                java_ty = "long"
-                c_ty = "jlong"
-                fn_ty_arg = "J"
-                fn_arg = ma.group(2).strip()
-                rust_obj = ma.group(1).strip()
-                take_by_ptr = True
-
-        if fn_arg.startswith(" *") or fn_arg.startswith("*"):
-            fn_arg = fn_arg.replace("*", "").strip()
-            is_ptr = True
-            c_ty = "jlong"
-            java_ty = "long"
-            fn_ty_arg = "J"
-
-        var_is_arr = var_is_arr_regex.match(fn_arg)
-        if var_is_arr is not None or ret_arr_len is not None:
-            assert(not take_by_ptr)
-            assert(not is_ptr)
-            java_ty = java_ty + "[]"
-            c_ty = c_ty + "Array"
-            if var_is_arr is not None:
-                if var_is_arr.group(1) == "":
-                    return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
-                        passed_as_ptr=False, is_ptr=False, var_name="arg", arr_len=var_is_arr.group(2), arr_access=arr_access)
-                return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
-                    passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2), arr_access=arr_access)
-        return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
-            is_ptr=is_ptr, var_name=fn_arg, arr_len=None, arr_access=None)
-
-    def map_type(fn_arg, print_void, ret_arr_len, is_free):
+    def map_type(fn_arg, print_void, ret_arr_len, is_free, holds_ref):

         ty_info = java_c_types(fn_arg, ret_arr_len)
         ty_info = java_c_types(fn_arg, ret_arr_len)

+        return map_type_with_info(ty_info, print_void, ret_arr_len, is_free, holds_ref)

 
 

+    def map_type_with_info(ty_info, print_void, ret_arr_len, is_free, holds_ref):

         if ty_info.c_ty == "void":
             if not print_void:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
         if ty_info.c_ty == "void":
             if not print_void:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                    arg_conv = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
-
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

         if ty_info.c_ty.endswith("Array"):
             arr_len = ty_info.arr_len
             if arr_len is not None:
         if ty_info.c_ty.endswith("Array"):
             arr_len = ty_info.arr_len
             if arr_len is not None:


@@ -215,20 +382,135 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             else:
                 arr_name = "ret"
                 arr_len = ret_arr_len
             else:
                 arr_name = "ret"
                 arr_len = ret_arr_len

-            assert(ty_info.c_ty == "jbyteArray")
-            if ty_info.rust_obj is not None:
-                arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n" + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_ref." + ty_info.arr_access + ");"
-                arr_access = ("", "." + ty_info.arr_access)
+            if ty_info.c_ty == "jbyteArray":
+                ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" + "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", ", "")
+                arg_conv_cleanup = None
+                if not arr_len.isdigit():
+                    arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
+                    arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = (*_env)->GetByteArrayElements (_env, " + arr_name + ", NULL);\n"
+                    arg_conv = arg_conv + arr_name + "_ref." + arr_len + " = (*_env)->GetArrayLength (_env, " + arr_name + ");"
+                    arg_conv_cleanup = "(*_env)->ReleaseByteArrayElements(_env, " + arr_name + ", (int8_t*)" + arr_name + "_ref." + ty_info.arr_access + ", 0);"
+                    ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
+                    ret_conv = (ret_conv[0], ";\njbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_name + "_var." + arr_len + ");\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_name + "_var." + arr_len + ", " + arr_name + "_var." + ty_info.arr_access + ");")
+                    if not holds_ref and ty_info.rust_obj == "LDKCVec_u8Z":
+                        ret_conv = (ret_conv[0], ret_conv[1] + "\nCVec_u8Z_free(" + arr_name + "_var);")
+                elif ty_info.rust_obj is not None:
+                    arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
+                    arg_conv = arg_conv + "CHECK((*_env)->GetArrayLength (_env, " + arr_name + ") == " + arr_len + ");\n"
+                    arg_conv = arg_conv + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_ref." + ty_info.arr_access + ");"
+                    ret_conv = (ret_conv[0], "." + ty_info.arr_access + ");")
+                else:
+                    arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n"
+                    arg_conv = arg_conv + "CHECK((*_env)->GetArrayLength (_env, " + arr_name + ") == " + arr_len + ");\n"
+                    arg_conv = arg_conv + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
+                    ret_conv = (ret_conv[0] + "*", ");")
+                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                    arg_conv = arg_conv, arg_conv_name = arr_name + "_ref", arg_conv_cleanup = arg_conv_cleanup,
+                    ret_conv = ret_conv, ret_conv_name = arr_name + "_arr", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

             else:
             else:

-                arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n" + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
-                arr_access = ("*", "")
-            return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                arg_conv = arg_conv,
-                arg_conv_name = arr_name + "_ref",
-                ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" +
-                    "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", " + arr_access[0],
-                    arr_access[1] + ");"),
-                ret_conv_name = arr_name + "_arr")
+                assert not arr_len.isdigit() # fixed length arrays not implemented
+                assert ty_info.java_ty[len(ty_info.java_ty) - 2:] == "[]"
+                conv_name = "arr_conv_" + str(len(ty_info.java_hu_ty))
+                idxc = chr(ord('a') + (len(ty_info.java_hu_ty) % 26))
+                ty_info.subty.var_name = conv_name
+                subty = map_type_with_info(ty_info.subty, False, None, is_free, holds_ref)
+                if arr_name == "":
+                    arr_name = "arg"
+                arg_conv = ty_info.rust_obj + " " + arr_name + "_constr;\n"
+                arg_conv = arg_conv + arr_name + "_constr." + arr_len + " = (*_env)->GetArrayLength (_env, " + arr_name + ");\n"
+                arg_conv = arg_conv + "if (" + arr_name + "_constr." + arr_len + " > 0)\n"
+                if subty.rust_obj is None:
+                    szof = subty.c_ty
+                else:
+                    szof = subty.rust_obj
+                arg_conv = arg_conv + "\t" + arr_name + "_constr." + ty_info.arr_access + " = MALLOC(" + arr_name + "_constr." + arr_len + " * sizeof(" + szof + "), \"" + ty_info.rust_obj + " Elements\");\n"
+                arg_conv = arg_conv + "else\n"
+                arg_conv = arg_conv + "\t" + arr_name + "_constr." + ty_info.arr_access + " = NULL;\n"
+                if not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
+                    arg_conv = arg_conv + ty_info.java_ty.strip("[]") + "* " + arr_name + "_vals = (*_env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (_env, " + arr_name + ", NULL);\n"
+                arg_conv = arg_conv + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_constr." + arr_len + "; " + idxc + "++) {\n"
+                if not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
+                    arg_conv = arg_conv + "\t" + ty_info.java_ty.strip("[]") + " " + conv_name + " = " + arr_name + "_vals[" + idxc + "];"
+                    if subty.arg_conv is not None:
+                        arg_conv = arg_conv + "\n\t" + subty.arg_conv.replace("\n", "\n\t")
+                else:
+                    arg_conv = arg_conv + "\tjobject " + conv_name + " = (*_env)->GetObjectArrayElement(_env, " + arr_name + ", " + idxc + ");\n"
+                    arg_conv = arg_conv + "\t" + subty.arg_conv.replace("\n", "\n\t")
+                arg_conv = arg_conv + "\n\t" + arr_name + "_constr." + ty_info.arr_access + "[" + idxc + "] = " + subty.arg_conv_name + ";\n}"
+                if not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
+                    arg_conv = arg_conv + "\n(*_env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements (_env, " + arr_name + ", " + arr_name + "_vals, 0);"
+                if ty_info.is_ptr:
+                    arg_conv_name = "&" + arr_name + "_constr"
+                else:
+                    arg_conv_name = arr_name + "_constr"
+                arg_conv_cleanup = None
+                if ty_info.is_ptr:
+                    arg_conv_cleanup = "FREE(" + arr_name + "_constr." + ty_info.arr_access + ");"
+
+                if arr_name == "arg":
+                    arr_name = "ret"
+                ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
+                if subty.ret_conv is None:
+                    ret_conv = ("DUMMY", "DUMMY")
+                elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
+                    ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = (*_env)->New" + ty_info.java_ty.strip("[]").title() + "Array(_env, " + arr_name + "_var." + arr_len + ");\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + subty.c_ty + " *" + arr_name + "_arr_ptr = (*_env)->GetPrimitiveArrayCritical(_env, " + arr_name + "_arr, NULL);\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_var." + arr_len + "; " + idxc + "++) {\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "\t" + subty.ret_conv[0].replace("\n", "\n\t"))
+                    ret_conv = (ret_conv[0], ret_conv[1] + arr_name + "_var." + ty_info.arr_access + "[" + idxc + "]" + subty.ret_conv[1].replace("\n", "\n\t"))
+                    ret_conv = (ret_conv[0], ret_conv[1] + "\n\t" + arr_name + "_arr_ptr[" + idxc + "] = " + subty.ret_conv_name + ";\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "}\n(*_env)->ReleasePrimitiveArrayCritical(_env, " + arr_name + "_arr, " + arr_name + "_arr_ptr, 0);")
+                else:
+                    ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = (*_env)->NewObjectArray(_env, " + arr_name + "_var." + arr_len + ", NULL, NULL);\n") # XXX: second arg needs to be a clazz!
+                    ret_conv = (ret_conv[0], ret_conv[1] + "for (size_t " + idxc + " = 0; " + idxc + " < " + arr_name + "_var." + arr_len + "; " + idxc + "++) {\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "\t" + subty.ret_conv[0].replace("\n", "\n\t"))
+                    ret_conv = (ret_conv[0], ret_conv[1] + arr_name + "_var." + ty_info.arr_access + "[" + idxc + "]" + subty.ret_conv[1].replace("\n", "\n\t"))
+                    ret_conv = (ret_conv[0], ret_conv[1] + "\n\t(*_env)->SetObjectArrayElement(_env, " + arr_name + "_arr, " + idxc + ", " + subty.ret_conv_name + ");\n")
+                    ret_conv = (ret_conv[0], ret_conv[1] + "}")
+                if not holds_ref:
+                    if subty.rust_obj is not None and subty.rust_obj in opaque_structs:
+                        ret_conv = (ret_conv[0], ret_conv[1] + "\nFREE(" + arr_name + "_var." + ty_info.arr_access + ");")
+                    else:
+                        ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_free(" + arr_name + "_var);")
+
+                to_hu_conv = None
+                to_hu_conv_name = None
+                if subty.to_hu_conv is not None:
+                    to_hu_conv = ty_info.java_hu_ty + " " + conv_name + "_arr = new " + ty_info.subty.java_hu_ty.split("<")[0] + "[" + arr_name + ".length];\n"
+                    to_hu_conv = to_hu_conv + "for (int " + idxc + " = 0; " + idxc + " < " + arr_name + ".length; " + idxc + "++) {\n"
+                    to_hu_conv = to_hu_conv + "\t" + subty.java_ty + " " + conv_name + " = " + arr_name + "[" + idxc + "];\n"
+                    to_hu_conv = to_hu_conv + "\t" + subty.to_hu_conv.replace("\n", "\n\t") + "\n"
+                    to_hu_conv = to_hu_conv + "\t" + conv_name + "_arr[" + idxc + "] = " + subty.to_hu_conv_name + ";\n}"
+                    to_hu_conv_name = conv_name + "_arr"
+                from_hu_conv = None
+                if subty.from_hu_conv is not None:
+                    if subty.java_ty == "long" and subty.java_hu_ty != "long":
+                        from_hu_conv = ("Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray()", "/* TODO 2 " + subty.java_hu_ty + "  */")
+                    elif subty.java_ty == "long":
+                        from_hu_conv = ("Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray()", "/* TODO 2 " + subty.java_hu_ty + "  */")
+                    else:
+                        from_hu_conv = ("(" + ty_info.java_ty + ")Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + subty.from_hu_conv[0] + ").toArray()", "/* TODO 2 " + subty.java_hu_ty + "  */")
+
+                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                    arg_conv = arg_conv, arg_conv_name = arg_conv_name, arg_conv_cleanup = arg_conv_cleanup,
+                    ret_conv = ret_conv, ret_conv_name = arr_name + "_arr", to_hu_conv = to_hu_conv, to_hu_conv_name = to_hu_conv_name, from_hu_conv = from_hu_conv)
+        elif ty_info.java_ty == "String":
+            if ty_info.arr_access is None:
+                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                    ret_conv = ("jstring " + ty_info.var_name + "_conv = (*_env)->NewStringUTF(_env, ", ");"), ret_conv_name = ty_info.var_name + "_conv",
+                    to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+            else:
+                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                    ret_conv = ("LDKStr " + ty_info.var_name + "_str = ",
+                        ";\nchar* " + ty_info.var_name + "_buf = MALLOC(" + ty_info.var_name + "_str." + ty_info.arr_len + " + 1, \"str conv buf\");\n" +
+                        "memcpy(" + ty_info.var_name + "_buf, " + ty_info.var_name + "_str." + ty_info.arr_access + ", " + ty_info.var_name + "_str." + ty_info.arr_len + ");\n" +
+                        ty_info.var_name + "_buf[" + ty_info.var_name + "_str." + ty_info.arr_len + "] = 0;\n" +
+                        "jstring " + ty_info.var_name + "_conv = (*_env)->NewStringUTF(_env, " + ty_info.var_name + "_str." + ty_info.arr_access + ");\n" +
+                        "FREE(" + ty_info.var_name + "_buf);"),
+                    ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

         elif ty_info.var_name != "":
             # If we have a parameter name, print it (noting that it may indicate its a pointer)
             if ty_info.rust_obj is not None:
         elif ty_info.var_name != "":
             # If we have a parameter name, print it (noting that it may indicate its a pointer)
             if ty_info.rust_obj is not None:


@@ -236,30 +518,40 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"
                 opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
                 opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"

-                if (ty_info.rust_obj.replace("LDK", "") + "_clone") in clone_fns and not ty_info.is_ptr and not is_free:
-                    # TODO: This is a bit too naive, even with the checks above, we really need to know if rust wants a ref or not, not just if its pass as a ptr.
-                    opaque_arg_conv = opaque_arg_conv + "\nif (" + ty_info.var_name + "_conv.inner != NULL)\n"
-                    opaque_arg_conv = opaque_arg_conv + "\t" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
+                if not ty_info.is_ptr and not is_free and not ty_info.pass_by_ref:
+                    if (ty_info.java_hu_ty + "_clone") in clone_fns:
+                        # TODO: This is a bit too naive, even with the checks above, we really need to know if rust wants a ref or not, not just if its pass as a ptr.
+                        opaque_arg_conv = opaque_arg_conv + "\nif (" + ty_info.var_name + "_conv.inner != NULL)\n"
+                        opaque_arg_conv = opaque_arg_conv + "\t" + ty_info.var_name + "_conv = " + ty_info.java_hu_ty + "_clone(&" + ty_info.var_name + "_conv);"
+                    elif ty_info.passed_as_ptr:
+                        opaque_arg_conv = opaque_arg_conv + "\n// Warning: we may need a move here but can't clone!"

                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
                             arg_conv_name = ty_info.var_name + "_conv",
                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
                             arg_conv_name = ty_info.var_name + "_conv",

+                            arg_conv_cleanup = None,

                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),

-                            ret_conv_name = ty_info.var_name + "_conv")
+                            ret_conv_name = ty_info.var_name + "_conv", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

                     if ty_info.rust_obj in opaque_structs:
                     if ty_info.rust_obj in opaque_structs:

-                        ret_conv_suf = ";\nDO_ASSERT((((long)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
-                        ret_conv_suf = ret_conv_suf + "DO_ASSERT((((long)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
-                        ret_conv_suf = ret_conv_suf + "long " + ty_info.var_name + "_ref;\n"
-                        ret_conv_suf = ret_conv_suf + "if (" + ty_info.var_name + "_var.is_owned) {\n"
-                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner | 1;\n"
-                        ret_conv_suf = ret_conv_suf + "} else {\n"
-                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)&" + ty_info.var_name + "_var;\n"
-                        ret_conv_suf = ret_conv_suf + "}"
+                        ret_conv_suf = ";\nCHECK((((long)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
+                        ret_conv_suf = ret_conv_suf + "CHECK((((long)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
+                        if holds_ref:
+                            ret_conv_suf = ret_conv_suf + "long " + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner & ~1;"
+                        else:
+                            ret_conv_suf = ret_conv_suf + "long " + ty_info.var_name + "_ref;\n"
+                            ret_conv_suf = ret_conv_suf + "if (" + ty_info.var_name + "_var.is_owned) {\n"
+                            ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner | 1;\n"
+                            ret_conv_suf = ret_conv_suf + "} else {\n"
+                            ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner & ~1;\n"
+                            ret_conv_suf = ret_conv_suf + "}"

                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                            arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv",
+                            arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,

                             ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", ret_conv_suf),
                             ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", ret_conv_suf),

-                            ret_conv_name = ty_info.var_name + "_ref")
+                            ret_conv_name = ty_info.var_name + "_ref",
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_hu_conv",
+                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr & ~1", "this.ptrs_to.add(" + ty_info.var_name + ")"))

                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
                     if ty_info.rust_obj in trait_structs:
                         if not is_free:
                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
                     if ty_info.rust_obj in trait_structs:
                         if not is_free:


@@ -269,57 +561,131 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         else:
                             base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         else:
                             base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                            arg_conv = base_conv,
-                            arg_conv_name = ty_info.var_name + "_conv",
-                            ret_conv = ("CANT PASS TRAIT TO Java?", ""), ret_conv_name = "NO CONV POSSIBLE")
-                    if ty_info.rust_obj != "LDKu8slice":
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = ("CANT PASS TRAIT TO Java?", ""), ret_conv_name = "NO CONV POSSIBLE",
+                            to_hu_conv = "DUMMY", to_hu_conv_name = None,
+                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", "this.ptrs_to.add(" + ty_info.var_name + ")"))
+                    if ty_info.rust_obj != "LDKu8slice" and ty_info.rust_obj != "LDKTransaction":

                         # Don't bother free'ing slices passed in - Rust doesn't auto-free the
                         # underlying unlike Vecs, and it gives Java more freedom.
                         base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";
                         # Don't bother free'ing slices passed in - Rust doesn't auto-free the
                         # underlying unlike Vecs, and it gives Java more freedom.
                         base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";

+                    if ty_info.rust_obj in complex_enums:
+                        ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";")
+                        if not ty_info.is_ptr and not holds_ref and (ty_info.java_hu_ty + "_clone") in clone_fns:
+                            ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_copy = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n", "")
+                            ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = " + ty_info.java_hu_ty + "_clone(&", ");\n")
+                            ret_conv = (ret_conv[0], ret_conv[1] + "long " + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_copy;")
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = ret_conv, ret_conv_name = ty_info.var_name + "_ref",
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))
+                    if ty_info.rust_obj in tuple_types:
+                        from_hu_conv = "bindings." + tuple_types[ty_info.rust_obj][1].replace("LDK", "") + "_new("
+                        to_hu_conv_pfx = ""
+                        to_hu_conv_sfx = ty_info.java_hu_ty + " " + ty_info.var_name + "_conv = new " + ty_info.java_hu_ty + "("
+                        for idx, conv in enumerate(tuple_types[ty_info.rust_obj][0]):
+                            if idx != 0:
+                                to_hu_conv_sfx = to_hu_conv_sfx + ", "
+                                from_hu_conv = from_hu_conv + ", "
+                            conv.var_name = ty_info.var_name + "_" + chr(idx + ord("a"))
+                            conv_map = map_type_with_info(conv, False, None, is_free, holds_ref)
+                            to_hu_conv_pfx = to_hu_conv_pfx + conv.java_ty + " " + ty_info.var_name + "_" + chr(idx + ord("a")) + " = " + "bindings." + tuple_types[ty_info.rust_obj][1] + "_get_" + chr(idx + ord("a")) + "(" + ty_info.var_name + ");\n"
+                            if conv_map.to_hu_conv is not None:
+                                to_hu_conv_pfx = to_hu_conv_pfx + conv_map.to_hu_conv + ";\n"
+                                to_hu_conv_sfx = to_hu_conv_sfx + conv_map.to_hu_conv_name
+                            else:
+                                to_hu_conv_sfx = to_hu_conv_sfx + ty_info.var_name + "_" + chr(idx + ord("a"))
+                            if conv_map.from_hu_conv is not None:
+                                from_hu_conv = from_hu_conv + conv_map.from_hu_conv[0].replace(ty_info.var_name + "_" + chr(idx + ord("a")), ty_info.var_name + "." + chr(idx + ord("a")))
+                                if conv_map.from_hu_conv[1] != "":
+                                    from_hu_conv = from_hu_conv + "/*XXX: Need to call " + conv_map.from_hu_conv[1] + "*/"
+                            else:
+                                from_hu_conv = from_hu_conv + ty_info.var_name + "." + chr(idx + ord("a"))
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref",
+                            to_hu_conv = to_hu_conv_pfx + to_hu_conv_sfx + ");", to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (from_hu_conv + ")", ""))
+
+                    # The manually-defined types - TxOut and Transaction
+                    assert ty_info.rust_obj == "LDKTransaction" or ty_info.rust_obj == "LDKTxOut"
+                    if ty_info.rust_obj == "LDKTransaction":
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = ("LDKTransaction *" + ty_info.var_name + "_copy = MALLOC(sizeof(LDKTransaction), \"LDKTransaction\");\n*" + ty_info.var_name + "_copy = ", ";\nlong " + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_copy;"),
+                            ret_conv_name = ty_info.var_name + "_ref",
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_conv = new " +ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))

                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                        arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv",
-                        ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref",
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_conv = new " +ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))

                 else:
                     assert(not is_free)
                     if ty_info.rust_obj in opaque_structs:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                 else:
                     assert(not is_free)
                     if ty_info.rust_obj in opaque_structs:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                            arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv",
-                            ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
+                            arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = None, ret_conv_name = None,
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = new " + ty_info.java_hu_ty + "(null, " + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_hu_conv",
+                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr & ~1", "this.ptrs_to.add(" + ty_info.var_name + ")")) # its a pointer, no conv needed
+                    elif ty_info.rust_obj in complex_enums:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
+                            arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = None, ret_conv_name = None,
+                            to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");",
+                            to_hu_conv_name = ty_info.var_name + "_hu_conv",
+                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr & ~1", "this.ptrs_to.add(" + ty_info.var_name + ")")) # its a pointer, no conv needed
+                    elif ty_info.rust_obj in trait_structs:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
+                            arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 2.5", to_hu_conv_name = None,
+                            from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", "this.ptrs_to.add(" + ty_info.var_name + ")")) # its a pointer, no conv needed

                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",

-                        arg_conv_name = ty_info.var_name + "_conv",
-                        ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
+                        arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                        ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 3", to_hu_conv_name = None, from_hu_conv = None) # its a pointer, no conv needed

             elif ty_info.is_ptr:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
             elif ty_info.is_ptr:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                    arg_conv = None, arg_conv_name = ty_info.var_name, ret_conv = None, ret_conv_name = None)
-            elif ty_info.java_ty == "String":
-                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = None,
-                    ret_conv = ("jstring " + ty_info.var_name + "_conv = (*_env)->NewStringUTF(_env, ", ");"), ret_conv_name = ty_info.var_name + "_conv")
+                    arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                    arg_conv = None, arg_conv_name = ty_info.var_name, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

         elif not print_void:
             # We don't have a parameter name, and want one, just call it arg
             if ty_info.rust_obj is not None:
         elif not print_void:
             # We don't have a parameter name, and want one, just call it arg
             if ty_info.rust_obj is not None:

-                assert(not is_free or ty_info.rust_obj not in opaque_structs);
+                assert(not is_free or ty_info.rust_obj not in opaque_structs)

                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",

-                    arg_conv_name = "arg_conv",
-                    ret_conv = None, ret_conv_name = None)
+                    arg_conv_name = "arg_conv", arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 7", to_hu_conv_name = None, from_hu_conv = None)

             else:
                 assert(not is_free)
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
             else:
                 assert(not is_free)
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                    arg_conv = None, arg_conv_name = "arg", ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = "arg", arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None, to_hu_conv = "TODO 8", to_hu_conv_name = None, from_hu_conv = None)

         else:
             # We don't have a parameter name, and don't want one (cause we're returning)
             if ty_info.rust_obj is not None:
                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
         else:
             # We don't have a parameter name, and don't want one (cause we're returning)
             if ty_info.rust_obj is not None:
                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                            arg_conv = ty_info.rust_obj + " ret = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
-                            arg_conv_name = "ret",
-                            ret_conv = ("jclass ret = " + ty_info.rust_obj + "_to_java(_env, ", ");"), ret_conv_name = "ret")
+                            arg_conv = ty_info.rust_obj + " ret_conv = " + ty_info.rust_obj + "_from_java(_env, ret);",
+                            arg_conv_name = "ret_conv", arg_conv_cleanup = None,
+                            ret_conv = ("jclass ret = " + ty_info.rust_obj + "_to_java(_env, ", ");"), ret_conv_name = "ret",
+                            to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+                    if ty_info.rust_obj in complex_enums or ty_info.rust_obj in result_types:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
+                            ret_conv_name = "(long)ret",
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(ret);\nret_hu_conv.ptrs_to.add(this);",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = ("ret != null ? ret.ptr : 0", ""))

                     if ty_info.rust_obj in opaque_structs:
                         # If we're returning a newly-allocated struct, we don't want Rust to ever
                         # free, instead relying on the Java GC to lose the ref. We undo this in
                     if ty_info.rust_obj in opaque_structs:
                         # If we're returning a newly-allocated struct, we don't want Rust to ever
                         # free, instead relying on the Java GC to lose the ref. We undo this in


@@ -328,19 +694,46 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             ret_conv = (ty_info.rust_obj + " ret = ", ";"),
                             ret_conv_name = "((long)ret.inner) | (ret.is_owned ? 1 : 0)",
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             ret_conv = (ty_info.rust_obj + " ret = ", ";"),
                             ret_conv_name = "((long)ret.inner) | (ret.is_owned ? 1 : 0)",

-                            arg_conv = None, arg_conv_name = None)
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = None)
+                    elif ty_info.rust_obj in trait_structs:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
+                            ret_conv_name = "(long)ret",
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);\nret_hu_conv.ptrs_to.add(this);",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = ("ret.ptr", ""))
+                    elif ty_info.rust_obj in tuple_types:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
+                            ret_conv_name = "(long)ret",
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);\nret_hu_conv.ptrs_to.add(this);",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = ("bindings." + ty_info.rust_obj.replace("LDK", "") + "_new(ret.a, ret.b)", ""))

                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
                             ret_conv_name = "(long)ret",
                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
                             ret_conv_name = "(long)ret",

-                            arg_conv = None, arg_conv_name = None)
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                            to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);\nret_hu_conv.ptrs_to.add(this);",
+                            to_hu_conv_name = "ret_hu_conv", from_hu_conv = None)
+                elif ty_info.rust_obj in trait_structs:
+                    return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                        ret_conv = ("long ret = (long)", ";"), ret_conv_name = "ret",
+                        arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                        to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);\nret_hu_conv.ptrs_to.add(this);",
+                        to_hu_conv_name = "ret_hu_conv", from_hu_conv = None)

                 else:
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         ret_conv = ("long ret = (long)", ";"), ret_conv_name = "ret",
                 else:
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         ret_conv = ("long ret = (long)", ";"), ret_conv_name = "ret",

-                        arg_conv = None, arg_conv_name = None)
+                        arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                        to_hu_conv = "TODO c", to_hu_conv_name = None, from_hu_conv = None)

             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                    arg_conv = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None,
+                    to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

 
     def map_fn(line, re_match, ret_arr_len, c_call_string):
         out_java.write("\t// " + line)
 
     def map_fn(line, re_match, ret_arr_len, c_call_string):
         out_java.write("\t// " + line)


@@ -350,7 +743,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         is_free = re_match.group(2).endswith("_free")
         struct_meth = re_match.group(2).split("_")[0]
 
         is_free = re_match.group(2).endswith("_free")
         struct_meth = re_match.group(2).split("_")[0]
 

-        ret_info = map_type(re_match.group(1), True, ret_arr_len, False)
+        ret_info = map_type(re_match.group(1), True, ret_arr_len, False, False)

         ret_info.print_ty()
 
         if ret_info.ret_conv is not None:
         ret_info.print_ty()
 
         if ret_info.ret_conv is not None:


@@ -360,53 +753,69 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")
 
         arg_names = []
         out_c.write(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")
 
         arg_names = []

+        default_constructor_args = {}

         takes_self = False
         takes_self = False

-        args_known = not ret_info.passed_as_ptr or ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs
+        args_known = not ret_info.passed_as_ptr or ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs or ret_info.rust_obj in complex_enums or ret_info.rust_obj in result_types

         for idx, arg in enumerate(re_match.group(3).split(',')):
             if idx != 0:
                 out_java.write(", ")
             if arg != "void":
                 out_c.write(", ")
         for idx, arg in enumerate(re_match.group(3).split(',')):
             if idx != 0:
                 out_java.write(", ")
             if arg != "void":
                 out_c.write(", ")

-            arg_conv_info = map_type(arg, False, None, is_free)
+            arg_conv_info = map_type(arg, False, None, is_free, False)

             if arg_conv_info.c_ty != "void":
                 arg_conv_info.print_ty()
                 arg_conv_info.print_name()
             if arg_conv_info.c_ty != "void":
                 arg_conv_info.print_ty()
                 arg_conv_info.print_name()

-            if arg_conv_info.arg_name == "this_arg":
+            if arg_conv_info.arg_name == "this_ptr" or arg_conv_info.arg_name == "this_arg":

                 takes_self = True
             if arg_conv_info.passed_as_ptr and not arg_conv_info.rust_obj in opaque_structs:
                 if not arg_conv_info.rust_obj in trait_structs and not arg_conv_info.rust_obj in unitary_enums:
                 takes_self = True
             if arg_conv_info.passed_as_ptr and not arg_conv_info.rust_obj in opaque_structs:
                 if not arg_conv_info.rust_obj in trait_structs and not arg_conv_info.rust_obj in unitary_enums:

-                    print(re_match.group(2) + " bad - " + arg_conv_info.rust_obj)
+                    args_known = False
+            if arg_conv_info.arg_conv is not None and "Warning" in arg_conv_info.arg_conv:
+                if arg_conv_info.rust_obj in constructor_fns:
+                    assert not is_free
+                    for explode_arg in constructor_fns[arg_conv_info.rust_obj].split(','):
+                        explode_arg_conv = map_type(explode_arg, False, None, False, False)
+                        if explode_arg_conv.c_ty == "void":
+                            # We actually want to handle this case, but for now its only used in NetGraphMsgHandler::new()
+                            # which ends up resulting in a redundant constructor - both without arguments for the NetworkGraph.
+                            args_known = False
+                        assert explode_arg_conv.arg_name != "this_ptr"
+                        assert explode_arg_conv.arg_name != "this_arg"
+                        if explode_arg_conv.passed_as_ptr and not explode_arg_conv.rust_obj in trait_structs:
+                            args_known = False
+                        if not arg_conv_info.arg_name in default_constructor_args:
+                            default_constructor_args[arg_conv_info.arg_name] = []
+                        default_constructor_args[arg_conv_info.arg_name].append(explode_arg_conv)
+                else:

                     args_known = False
             arg_names.append(arg_conv_info)
 
         out_java_struct = None
                     args_known = False
             arg_names.append(arg_conv_info)
 
         out_java_struct = None

-        if "LDK" + struct_meth in opaque_structs and not is_free:
+        if ("LDK" + struct_meth in opaque_structs or "LDK" + struct_meth in trait_structs) and not is_free:

             out_java_struct = open(sys.argv[3] + "/structs/" + struct_meth + ".java", "a")
             if not args_known:
                 out_java_struct.write("\t// Skipped " + re_match.group(2) + "\n")
                 out_java_struct.close()
                 out_java_struct = None
             else:
             out_java_struct = open(sys.argv[3] + "/structs/" + struct_meth + ".java", "a")
             if not args_known:
                 out_java_struct.write("\t// Skipped " + re_match.group(2) + "\n")
                 out_java_struct.close()
                 out_java_struct = None
             else:

-                out_java_struct.write("\tpublic ")

                 meth_n = re_match.group(2)[len(struct_meth) + 1:]
                 if ret_info.rust_obj == "LDK" + struct_meth:
                 meth_n = re_match.group(2)[len(struct_meth) + 1:]
                 if ret_info.rust_obj == "LDK" + struct_meth:

-                    out_java_struct.write(struct_meth + "(")
-                elif ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs:
-                    out_java_struct.write(ret_info.rust_obj.replace("LDK", "") + " " + meth_n + "(")
+                    out_java_struct.write("\tpublic static " + ret_info.java_hu_ty + " constructor_" + meth_n + "(")

                 else:
                 else:

-                    out_java_struct.write(ret_info.java_ty + " " + meth_n + "(")
+                    out_java_struct.write("\tpublic " + ret_info.java_hu_ty + " " + meth_n + "(")

                 for idx, arg in enumerate(arg_names):
                     if idx != 0:
                         if not takes_self or idx > 1:
                             out_java_struct.write(", ")
                 for idx, arg in enumerate(arg_names):
                     if idx != 0:
                         if not takes_self or idx > 1:
                             out_java_struct.write(", ")

-                    if arg.java_ty != "void" and arg.arg_name != "this_arg":
-                        if arg.passed_as_ptr:
-                            if arg.rust_obj in opaque_structs or arg.rust_obj in trait_structs:
-                                out_java_struct.write(arg.rust_obj.replace("LDK", "") + " " + arg.arg_name)
-                            else:
-                                out_java_struct.write(arg.rust_obj + " " + arg.arg_name)
+                    if arg.java_ty != "void" and arg.arg_name != "this_ptr" and arg.arg_name != "this_arg":
+                        if arg.arg_name in default_constructor_args:
+                            for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
+                                if explode_idx != 0:
+                                    out_java_struct.write(", ")
+                                assert explode_arg.rust_obj in opaque_structs or explode_arg.rust_obj in trait_structs
+                                out_java_struct.write(explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)

                         else:
                         else:

-                            out_java_struct.write(arg.java_ty + " " + arg.arg_name)
+                            out_java_struct.write(arg.java_hu_ty + " " + arg.arg_name)

 
 
         out_java.write(");\n")
 
 
         out_java.write(");\n")


@@ -416,12 +825,14 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
 
         for info in arg_names:
             if info.arg_conv is not None:
 
         for info in arg_names:
             if info.arg_conv is not None:

-                out_c.write("\t" + info.arg_conv.replace('\n', "\n\t") + "\n");
+                out_c.write("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")

 
         if ret_info.ret_conv is not None:
 
         if ret_info.ret_conv is not None:

-            out_c.write("\t" + ret_conv_pfx.replace('\n', '\n\t'));
+            out_c.write("\t" + ret_conv_pfx.replace('\n', '\n\t'))
+        elif ret_info.c_ty != "void":
+            out_c.write("\t" + ret_info.c_ty + " ret_val = ")

         else:
         else:

-            out_c.write("\treturn ");
+            out_c.write("\t")

 
         if c_call_string is None:
             out_c.write(re_match.group(2) + "(")
 
         if c_call_string is None:
             out_c.write(re_match.group(2) + "(")


@@ -437,49 +848,58 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write(")")
         if ret_info.ret_conv is not None:
             out_c.write(ret_conv_sfx.replace('\n', '\n\t'))
         out_c.write(")")
         if ret_info.ret_conv is not None:
             out_c.write(ret_conv_sfx.replace('\n', '\n\t'))

-            out_c.write("\n\treturn " + ret_info.ret_conv_name + ";")

         else:
             out_c.write(";")
         else:
             out_c.write(";")

+        for info in arg_names:
+            if info.arg_conv_cleanup is not None:
+                out_c.write("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
+        if ret_info.ret_conv is not None:
+            out_c.write("\n\treturn " + ret_info.ret_conv_name + ";")
+        elif ret_info.c_ty != "void":
+            out_c.write("\n\treturn ret_val;")

         out_c.write("\n}\n\n")
         if out_java_struct is not None:
             out_java_struct.write("\t\t")
         out_c.write("\n}\n\n")
         if out_java_struct is not None:
             out_java_struct.write("\t\t")

-            if ret_info.rust_obj == "LDK" + struct_meth:
-                out_java_struct.write("super(")
-            elif ret_info.java_ty != "void" and not ret_info.passed_as_ptr:
+            if ret_info.java_ty != "void":

                 out_java_struct.write(ret_info.java_ty + " ret = ")
                 out_java_struct.write(ret_info.java_ty + " ret = ")

-            elif ret_info.java_ty != "void":
-                out_java_struct.write(ret_info.rust_obj.replace("LDK", "") + " ret = ")
-                if ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs:
-                    out_java_struct.write("new " + ret_info.rust_obj.replace("LDK", "") + "(null, ")

             out_java_struct.write("bindings." + re_match.group(2) + "(")
             for idx, info in enumerate(arg_names):
                 if idx != 0:
                     out_java_struct.write(", ")
             out_java_struct.write("bindings." + re_match.group(2) + "(")
             for idx, info in enumerate(arg_names):
                 if idx != 0:
                     out_java_struct.write(", ")

-                if info.arg_name == "this_arg":
+                if info.arg_name == "this_ptr" or info.arg_name == "this_arg":

                     out_java_struct.write("this.ptr")
                     out_java_struct.write("this.ptr")

-                elif info.passed_as_ptr and info.rust_obj in opaque_structs:
-                    out_java_struct.write(info.arg_name + ".ptr & ~1")
-                elif info.passed_as_ptr and info.rust_obj in trait_structs:
-                    out_java_struct.write(info.arg_name + ".ptr")
+                elif info.arg_name in default_constructor_args:
+                    out_java_struct.write("bindings." + info.java_hu_ty + "_new(")
+                    for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
+                        if explode_idx != 0:
+                            out_java_struct.write(", ")
+                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
+                        out_java_struct.write(explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
+                    out_java_struct.write(")")
+                elif info.from_hu_conv is not None:
+                    out_java_struct.write(info.from_hu_conv[0])

                 else:
                     out_java_struct.write(info.arg_name)
                 else:
                     out_java_struct.write(info.arg_name)

-            out_java_struct.write(")")
-            if ret_info.rust_obj == "LDK" + struct_meth:
-                out_java_struct.write(");\n")
-            elif ret_info.rust_obj in opaque_structs:
-                out_java_struct.write(");\n")
-            elif ret_info.rust_obj in trait_structs:
-                out_java_struct.write(");\n\t\tret.ptrs_to.add(this);\n")
-            else:
-                out_java_struct.write(";\n")
+            out_java_struct.write(");\n")
+            if ret_info.to_hu_conv is not None:
+                out_java_struct.write("\t\t" + ret_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")

 
             for info in arg_names:
 
             for info in arg_names:

-                if info.arg_name == "this_arg":
+                if info.arg_name == "this_ptr" or info.arg_name == "this_arg":

                     pass
                     pass

-                elif info.passed_as_ptr and (info.rust_obj in opaque_structs or info.rust_obj in trait_structs):
-                    out_java_struct.write("\t\tthis.ptrs_to.add(" + info.arg_name + ");\n")
+                elif info.arg_name in default_constructor_args:
+                    for explode_arg in default_constructor_args[info.arg_name]:
+                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
+                        out_java_struct.write("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name, expl_arg_name).replace("this", ret_info.to_hu_conv_name) + ";\n")
+                elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
+                    if ret_info.rust_obj == "LDK" + struct_meth and ret_info.to_hu_conv_name is not None:
+                        out_java_struct.write("\t\t" + info.from_hu_conv[1].replace("this", ret_info.to_hu_conv_name) + ";\n")
+                    else:
+                        out_java_struct.write("\t\t" + info.from_hu_conv[1] + ";\n")

 
 

-            if ret_info.java_ty != "void" and ret_info.rust_obj != "LDK" + struct_meth:
+            if ret_info.to_hu_conv_name is not None:
+                out_java_struct.write("\t\treturn " + ret_info.to_hu_conv_name + ";\n")
+            elif ret_info.java_ty != "void" and ret_info.rust_obj != "LDK" + struct_meth:

                 out_java_struct.write("\t\treturn ret;\n")
             out_java_struct.write("\t}\n\n")
             out_java_struct.close()
                 out_java_struct.write("\t\treturn ret;\n")
             out_java_struct.write("\t}\n\n")
             out_java_struct.close()


@@ -519,12 +939,12 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     out_c.write("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
             out_c.write("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
             out_c.write("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")
                     out_c.write("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
             out_c.write("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
             out_c.write("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")

-            out_c.write("\tDO_ASSERT(" + struct_name + "_class != NULL);\n")
+            out_c.write("\tCHECK(" + struct_name + "_class != NULL);\n")

             for idx, struct_line in enumerate(field_lines):
                 if idx > 0 and idx < len(field_lines) - 3:
                     variant = struct_line.strip().strip(",")
                     out_c.write("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")
             for idx, struct_line in enumerate(field_lines):
                 if idx > 0 and idx < len(field_lines) - 3:
                     variant = struct_line.strip().strip(",")
                     out_c.write("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")

-                    out_c.write("\tDO_ASSERT(" + struct_name + "_" + variant + " != NULL);\n")
+                    out_c.write("\tCHECK(" + struct_name + "_" + variant + " != NULL);\n")

             out_c.write("}\n")
             out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
             out_c.write("\tswitch (val) {\n")
             out_c.write("}\n")
             out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
             out_c.write("\tswitch (val) {\n")


@@ -539,80 +959,113 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             out_c.write("}\n\n")
 
     def map_complex_enum(struct_name, union_enum_items):
             out_c.write("}\n\n")
 
     def map_complex_enum(struct_name, union_enum_items):

-        tag_field_lines = union_enum_items["field_lines"]
-        init_meth_jty_strs = {}
-        for idx, struct_line in enumerate(tag_field_lines):
-            if idx == 0:
-                out_java.write("\tpublic static class " + struct_name + " {\n")
-                out_java.write("\t\tprivate " + struct_name + "() {}\n")
-            elif idx == len(tag_field_lines) - 3:
-                assert(struct_line.endswith("_Sentinel,"))
-            elif idx == len(tag_field_lines) - 2:
-                out_java.write("\t\tstatic native void init();\n")
-                out_java.write("\t}\n")
-            elif idx == len(tag_field_lines) - 1:
-                assert(struct_line == "")
-            else:
-                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                out_java.write("\t\tpublic final static class " + var_name + " extends " + struct_name + " {\n")
-                out_c.write("static jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
-                out_c.write("static jmethodID " + struct_name + "_" + var_name + "_meth = NULL;\n")
-                init_meth_jty_str = ""
-                init_meth_params = ""
-                init_meth_body = ""
-                if "LDK" + var_name in union_enum_items:
-                    enum_var_lines = union_enum_items["LDK" + var_name]
-                    for idx, field in enumerate(enum_var_lines):
-                        if idx != 0 and idx < len(enum_var_lines) - 2:
-                            field_ty = java_c_types(field.strip(' ;'), None)
-                            out_java.write("\t\t\tpublic " + field_ty.java_ty + " " + field_ty.var_name + ";\n")
-                            init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
-                            if idx > 1:
-                                init_meth_params = init_meth_params + ", "
-                            init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.var_name
-                            init_meth_body = init_meth_body + "this." + field_ty.var_name + " = " + field_ty.var_name + "; "
-                    out_java.write("\t\t\t" + var_name + "(" + init_meth_params + ") { ")
-                    out_java.write(init_meth_body)
-                    out_java.write("}\n")
-                out_java.write("\t\t}\n")
-                init_meth_jty_strs[var_name] = init_meth_jty_str
-        out_java.write("\tstatic { " + struct_name + ".init(); }\n")
-        out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
-
-        out_c.write("JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass _a) {\n")
-        for idx, struct_line in enumerate(tag_field_lines):
-            if idx != 0 and idx < len(tag_field_lines) - 3:
-                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                out_c.write("\t" + struct_name + "_" + var_name + "_class =\n")
-                out_c.write("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
-                out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_class != NULL);\n")
-                out_c.write("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
-                out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_meth != NULL);\n")
-        out_c.write("}\n")
-        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * env, jclass _c, jlong ptr) {\n")
-        out_c.write("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
-        out_c.write("\tswitch(obj->tag) {\n")
-        for idx, struct_line in enumerate(tag_field_lines):
-            if idx != 0 and idx < len(tag_field_lines) - 3:
-                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                out_c.write("\t\tcase " + struct_name + "_" + var_name + ": {\n")
-                c_params_text = ""
-                if "LDK" + var_name in union_enum_items:
-                    enum_var_lines = union_enum_items["LDK" + var_name]
-                    for idx, field in enumerate(enum_var_lines):
-                        if idx != 0 and idx < len(enum_var_lines) - 2:
-                            field_map = map_type(field.strip(' ;'), False, None, False)
-                            if field_map.ret_conv is not None:
-                                out_c.write("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t").replace("_env", "env"))
-                                out_c.write("obj->" + camel_to_snake(var_name) + "." + field_map.arg_name)
-                                out_c.write(field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
-                                c_params_text = c_params_text + ", " + field_map.ret_conv_name
-                            else:
-                                c_params_text = c_params_text + ", obj->" + camel_to_snake(var_name) + "." + field_map.arg_name
-                out_c.write("\t\t\treturn (*env)->NewObject(env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth" + c_params_text + ");\n")
-                out_c.write("\t\t}\n")
-        out_c.write("\t\tdefault: abort();\n")
-        out_c.write("\t}\n}\n")
+        java_hu_type = struct_name.replace("LDK", "")
+        complex_enums.add(struct_name)
+        with open(sys.argv[3] + "/structs/" + java_hu_type + ".java", "w") as out_java_enum:
+            out_java_enum.write(hu_struct_file_prefix)
+            out_java_enum.write("public class " + java_hu_type + " extends CommonBase {\n")
+            out_java_enum.write("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
+            out_java_enum.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
+            out_java_enum.write("\tprotected void finalize() throws Throwable {\n")
+            out_java_enum.write("\t\tsuper.finalize();\n")
+            out_java_enum.write("\t\tif (ptr != 0) { bindings." + java_hu_type + "_free(ptr); }\n")
+            out_java_enum.write("\t}\n")
+            out_java_enum.write("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
+            out_java_enum.write("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
+            java_hu_subclasses = ""
+
+            tag_field_lines = union_enum_items["field_lines"]
+            init_meth_jty_strs = {}
+            for idx, struct_line in enumerate(tag_field_lines):
+                if idx == 0:
+                    out_java.write("\tpublic static class " + struct_name + " {\n")
+                    out_java.write("\t\tprivate " + struct_name + "() {}\n")
+                elif idx == len(tag_field_lines) - 3:
+                    assert(struct_line.endswith("_Sentinel,"))
+                elif idx == len(tag_field_lines) - 2:
+                    out_java.write("\t\tstatic native void init();\n")
+                    out_java.write("\t}\n")
+                elif idx == len(tag_field_lines) - 1:
+                    assert(struct_line == "")
+                else:
+                    var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                    out_java.write("\t\tpublic final static class " + var_name + " extends " + struct_name + " {\n")
+                    java_hu_subclasses = java_hu_subclasses + "\tpublic final static class " + var_name + " extends " + java_hu_type + " {\n"
+                    out_java_enum.write("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var_name + ".class) {\n")
+                    out_java_enum.write("\t\t\treturn new " + var_name + "(ptr, (bindings." + struct_name + "." + var_name + ")raw_val);\n")
+                    out_c.write("static jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
+                    out_c.write("static jmethodID " + struct_name + "_" + var_name + "_meth = NULL;\n")
+                    init_meth_jty_str = ""
+                    init_meth_params = ""
+                    init_meth_body = ""
+                    hu_conv_body = ""
+                    if "LDK" + var_name in union_enum_items:
+                        enum_var_lines = union_enum_items["LDK" + var_name]
+                        for idx, field in enumerate(enum_var_lines):
+                            if idx != 0 and idx < len(enum_var_lines) - 2:
+                                field_ty = map_type(field.strip(' ;'), False, None, False, True)
+                                out_java.write("\t\t\tpublic " + field_ty.java_ty + " " + field_ty.arg_name + ";\n")
+                                java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_ty.java_hu_ty + " " + field_ty.arg_name + ";\n"
+                                if field_ty.to_hu_conv is not None:
+                                    hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
+                                    hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
+                                    hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
+                                else:
+                                    hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
+                                init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
+                                if idx > 1:
+                                    init_meth_params = init_meth_params + ", "
+                                init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.arg_name
+                                init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
+                        out_java.write("\t\t\t" + var_name + "(" + init_meth_params + ") { ")
+                        out_java.write(init_meth_body)
+                        out_java.write("}\n")
+                    out_java.write("\t\t}\n")
+                    out_java_enum.write("\t\t}\n")
+                    java_hu_subclasses = java_hu_subclasses + "\t\tprivate " + var_name + "(long ptr, bindings." + struct_name + "." + var_name + " obj) {\n\t\t\tsuper(null, ptr);\n"
+                    java_hu_subclasses = java_hu_subclasses + hu_conv_body
+                    java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
+                    init_meth_jty_strs[var_name] = init_meth_jty_str
+            out_java_enum.write("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
+            out_java_enum.write(java_hu_subclasses)
+            out_java.write("\tstatic { " + struct_name + ".init(); }\n")
+            out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
+
+            out_c.write("JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass _a) {\n")
+            for idx, struct_line in enumerate(tag_field_lines):
+                if idx != 0 and idx < len(tag_field_lines) - 3:
+                    var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                    out_c.write("\t" + struct_name + "_" + var_name + "_class =\n")
+                    out_c.write("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
+                    out_c.write("\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n")
+                    out_c.write("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
+                    out_c.write("\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n")
+            out_c.write("}\n")
+            out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * _env, jclass _c, jlong ptr) {\n")
+            out_c.write("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
+            out_c.write("\tswitch(obj->tag) {\n")
+            for idx, struct_line in enumerate(tag_field_lines):
+                if idx != 0 and idx < len(tag_field_lines) - 3:
+                    var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                    out_c.write("\t\tcase " + struct_name + "_" + var_name + ": {\n")
+                    c_params_text = ""
+                    if "LDK" + var_name in union_enum_items:
+                        enum_var_lines = union_enum_items["LDK" + var_name]
+                        for idx, field in enumerate(enum_var_lines):
+                            if idx != 0 and idx < len(enum_var_lines) - 2:
+                                field_map = map_type(field.strip(' ;'), False, None, False, True)
+                                if field_map.ret_conv is not None:
+                                    out_c.write("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
+                                    out_c.write("obj->" + camel_to_snake(var_name) + "." + field_map.arg_name)
+                                    out_c.write(field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
+                                    c_params_text = c_params_text + ", " + field_map.ret_conv_name
+                                else:
+                                    c_params_text = c_params_text + ", obj->" + camel_to_snake(var_name) + "." + field_map.arg_name
+                    out_c.write("\t\t\treturn (*_env)->NewObject(_env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth" + c_params_text + ");\n")
+                    out_c.write("\t\t}\n")
+            out_c.write("\t\tdefault: abort();\n")
+            out_c.write("\t}\n}\n")
+            out_java_enum.write("}\n")

 
     def map_trait(struct_name, field_var_lines, trait_fn_lines):
         with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_trait:
 
     def map_trait(struct_name, field_var_lines, trait_fn_lines):
         with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_trait:


@@ -628,11 +1081,11 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
             out_c.write("} " + struct_name + "_JCalls;\n")
 
                     out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
             out_c.write("} " + struct_name + "_JCalls;\n")
 

-            out_java_trait.write("package org.ldk.structs;\n\n")
-            out_java_trait.write("import org.ldk.impl.bindings;\n\n")
+            out_java_trait.write(hu_struct_file_prefix)

             out_java_trait.write("public class " + struct_name.replace("LDK","") + " extends CommonBase {\n")
             out_java_trait.write("public class " + struct_name.replace("LDK","") + " extends CommonBase {\n")

-            out_java_trait.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
-            out_java_trait.write("\tpublic " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg")
+            out_java_trait.write("\tfinal bindings." + struct_name + " bindings_instance;\n")
+            out_java_trait.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n")
+            out_java_trait.write("\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg")

             for var_line in field_var_lines:
                 if var_line.group(1) in trait_structs:
                     out_java_trait.write(", bindings." + var_line.group(1) + " " + var_line.group(2))
             for var_line in field_var_lines:
                 if var_line.group(1) in trait_structs:
                     out_java_trait.write(", bindings." + var_line.group(1) + " " + var_line.group(2))


@@ -643,21 +1096,31 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     out_java_trait.write(", " + var_line.group(2))
             out_java_trait.write("));\n")
             out_java_trait.write("\t\tthis.ptrs_to.add(arg);\n")
                     out_java_trait.write(", " + var_line.group(2))
             out_java_trait.write("));\n")
             out_java_trait.write("\t\tthis.ptrs_to.add(arg);\n")

+            out_java_trait.write("\t\tthis.bindings_instance = arg;\n")

             out_java_trait.write("\t}\n")
             out_java_trait.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
             out_java_trait.write("\tprotected void finalize() throws Throwable {\n")
             out_java_trait.write("\t}\n")
             out_java_trait.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
             out_java_trait.write("\tprotected void finalize() throws Throwable {\n")

-            out_java_trait.write("\t\tbindings." + struct_name.replace("LDK","") + "_free(ptr); super.finalize();\n")
+            out_java_trait.write("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n")

             out_java_trait.write("\t}\n\n")
             out_java_trait.write("\t}\n\n")

-            out_java_trait.write("}\n")

 
 

+            java_trait_constr = "\tpublic " + struct_name.replace("LDK", "") + "(" + struct_name.replace("LDK", "") + "Interface arg"
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    # Ideally we'd be able to take any instance of the interface, but our C code can only represent
+                    # Java-implemented version, so we require users pass a Java implementation here :/
+                    java_trait_constr = java_trait_constr + ", " + var_line.group(1).replace("LDK", "") + "." + var_line.group(1).replace("LDK", "") + "Interface " + var_line.group(2)
+            java_trait_constr = java_trait_constr + ") {\n\t\tthis(new bindings." + struct_name + "() {\n"
+            out_java_trait.write("\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n")

             out_java.write("\tpublic interface " + struct_name + " {\n")
             java_meths = []
             for fn_line in trait_fn_lines:
                 java_meth_descr = "("
                 if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
             out_java.write("\tpublic interface " + struct_name + " {\n")
             java_meths = []
             for fn_line in trait_fn_lines:
                 java_meth_descr = "("
                 if fn_line.group(2) != "free" and fn_line.group(2) != "clone":

-                    ret_ty_info = java_c_types(fn_line.group(1), None)
+                    ret_ty_info = map_type(fn_line.group(1), True, None, False, False)

 
                     out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")
 
                     out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")

+                    java_trait_constr = java_trait_constr + "\t\t\t@Override public " + ret_ty_info.java_ty + " " + fn_line.group(2) + "("
+                    out_java_trait.write("\t\t" + ret_ty_info.java_hu_ty + " " + fn_line.group(2) + "(")

                     is_const = fn_line.group(3) is not None
                     out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
                     if is_const:
                     is_const = fn_line.group(3) is not None
                     out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
                     if is_const:


@@ -671,52 +1134,79 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                             continue
                         if idx >= 2:
                             out_java.write(", ")
                             continue
                         if idx >= 2:
                             out_java.write(", ")

+                            java_trait_constr = java_trait_constr + ", "
+                            out_java_trait.write(", ")

                         out_c.write(", ")
                         out_c.write(", ")

-                        arg_conv_info = map_type(arg, True, None, False)
+                        arg_conv_info = map_type(arg, True, None, False, False)

                         out_c.write(arg.strip())
                         out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
                         out_c.write(arg.strip())
                         out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)

+                        out_java_trait.write(arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name)
+                        java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name

                         arg_names.append(arg_conv_info)
                         java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
                     java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
                     java_meths.append(java_meth_descr)
 
                     out_java.write(");\n")
                         arg_names.append(arg_conv_info)
                         java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
                     java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
                     java_meths.append(java_meth_descr)
 
                     out_java.write(");\n")

+                    out_java_trait.write(");\n")
+                    java_trait_constr = java_trait_constr + ") {\n"

                     out_c.write(") {\n")
                     out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
                     out_c.write(") {\n")
                     out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")

-                    out_c.write("\tJNIEnv *env;\n")
-                    out_c.write("\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
+                    out_c.write("\tJNIEnv *_env;\n")
+                    out_c.write("\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&_env, JNI_VERSION_1_8) == JNI_OK);\n")

 
                     for arg_info in arg_names:
                         if arg_info.ret_conv is not None:
 
                     for arg_info in arg_names:
                         if arg_info.ret_conv is not None:

-                            out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t').replace("_env", "env"));
+                            out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t'));

                             out_c.write(arg_info.arg_name)
                             out_c.write(arg_info.arg_name)

-                            out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
+                            out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t') + "\n")
+                        if arg_info.to_hu_conv is not None:
+                            java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"

 
 

-                    out_c.write("\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tDO_ASSERT(obj != NULL);\n")
+                    out_c.write("\tjobject obj = (*_env)->NewLocalRef(_env, j_calls->o);\n\tCHECK(obj != NULL);\n")

                     if ret_ty_info.c_ty.endswith("Array"):
                     if ret_ty_info.c_ty.endswith("Array"):

-                        assert(ret_ty_info.c_ty == "jbyteArray")
-                        out_c.write("\tjbyteArray jret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                        out_c.write("\t" + ret_ty_info.c_ty + " ret = (*_env)->CallObjectMethod(_env, obj, j_calls->" + fn_line.group(2) + "_meth")

                     elif not ret_ty_info.passed_as_ptr:
                     elif not ret_ty_info.passed_as_ptr:

-                        out_c.write("\treturn (*env)->Call" + ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                        out_c.write("\treturn (*_env)->Call" + ret_ty_info.java_ty.title() + "Method(_env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    else:
+                        out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*_env)->CallLongMethod(_env, obj, j_calls->" + fn_line.group(2) + "_meth");
+                    if ret_ty_info.java_ty != "void":
+                        java_trait_constr = java_trait_constr + "\t\t\t\t" + ret_ty_info.java_hu_ty + " ret = arg." + fn_line.group(2) + "("

                     else:
                     else:

-                        out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*env)->CallLongMethod(env, obj, j_calls->" + fn_line.group(2) + "_meth");
+                        java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.group(2) + "("

 
 

-                    for arg_info in arg_names:
+                    for idx, arg_info in enumerate(arg_names):

                         if arg_info.ret_conv is not None:
                             out_c.write(", " + arg_info.ret_conv_name)
                         else:
                             out_c.write(", " + arg_info.arg_name)
                         if arg_info.ret_conv is not None:
                             out_c.write(", " + arg_info.ret_conv_name)
                         else:
                             out_c.write(", " + arg_info.arg_name)

+                        if idx != 0:
+                            java_trait_constr = java_trait_constr + ", "
+                        if arg_info.to_hu_conv_name is not None:
+                            java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
+                        else:
+                            java_trait_constr = java_trait_constr + arg_info.arg_name

                     out_c.write(");\n");
                     out_c.write(");\n");

-                    if ret_ty_info.c_ty.endswith("Array"):
-                        out_c.write("\t" + ret_ty_info.rust_obj + " ret;\n")
-                        out_c.write("\t(*env)->GetByteArrayRegion(env, jret, 0, " + ret_ty_info.arr_len + ", ret." + ret_ty_info.arr_access + ");\n")
-                        out_c.write("\treturn ret;\n")
+                    if ret_ty_info.arg_conv is not None:
+                        out_c.write("\t" + ret_ty_info.arg_conv.replace("\n", "\n\t").replace("arg", "ret") + "\n\treturn " + ret_ty_info.arg_conv_name.replace("arg", "ret") + ";\n")

 
                     if ret_ty_info.passed_as_ptr:
                         out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
                         out_c.write("\tFREE(ret);\n")
                         out_c.write("\treturn res;\n")
                     out_c.write("}\n")
 
                     if ret_ty_info.passed_as_ptr:
                         out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
                         out_c.write("\tFREE(ret);\n")
                         out_c.write("\treturn res;\n")
                     out_c.write("}\n")

+                    java_trait_constr = java_trait_constr + ");\n"
+                    if ret_ty_info.java_ty != "void":
+                        if ret_ty_info.from_hu_conv is not None:
+                            java_trait_constr = java_trait_constr + "\t\t\t\t" + ret_ty_info.java_ty + " result = " + ret_ty_info.from_hu_conv[0] + ";\n"
+                            if ret_ty_info.from_hu_conv[1] != "":
+                                java_trait_constr = java_trait_constr + "\t\t\t\t" + ret_ty_info.from_hu_conv[1] + "\n"
+                            if is_common_base_ext(ret_ty_info.rust_obj):
+                                java_trait_constr = java_trait_constr + "\t\t\t\tret.ptr = 0;\n"
+                            java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
+                        else:
+                            java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
+                    java_trait_constr = java_trait_constr + "\t\t\t}\n"

                 elif fn_line.group(2) == "free":
                     out_c.write("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
                     out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
                 elif fn_line.group(2) == "free":
                     out_c.write("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
                     out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")


@@ -726,6 +1216,12 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     out_c.write("\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n")
                     out_c.write("\t\tFREE(j_calls);\n")
                     out_c.write("\t}\n}\n")
                     out_c.write("\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n")
                     out_c.write("\t\tFREE(j_calls);\n")
                     out_c.write("\t}\n}\n")

+            java_trait_constr = java_trait_constr + "\t\t}"
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    java_trait_constr = java_trait_constr + ", new " + var_line.group(2) + "(" + var_line.group(2) + ").bindings_instance"
+            out_java_trait.write("\t}\n")
+            out_java_trait.write(java_trait_constr + ");\n\t}\n")

 
             # Write out a clone function whether we need one or not, as we use them in moving to rust
             out_c.write("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
 
             # Write out a clone function whether we need one or not, as we use them in moving to rust
             out_c.write("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")


@@ -749,7 +1245,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             out_c.write(") {\n")
 
             out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
             out_c.write(") {\n")
 
             out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")

-            out_c.write("\tDO_ASSERT(c != NULL);\n")
+            out_c.write("\tCHECK(c != NULL);\n")

             out_c.write("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
             out_c.write("\tatomic_init(&calls->refcnt, 1);\n")
             out_c.write("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")
             out_c.write("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
             out_c.write("\tatomic_init(&calls->refcnt, 1);\n")
             out_c.write("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")


@@ -757,7 +1253,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             for (fn_line, java_meth_descr) in zip(trait_fn_lines, java_meths):
                 if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
                     out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")
             for (fn_line, java_meth_descr) in zip(trait_fn_lines, java_meths):
                 if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
                     out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")

-                    out_c.write("\tDO_ASSERT(calls->" + fn_line.group(2) + "_meth != NULL);\n")
+                    out_c.write("\tCHECK(calls->" + fn_line.group(2) + "_meth != NULL);\n")

             out_c.write("\n\t" + struct_name + " ret = {\n")
             out_c.write("\t\t.this_arg = (void*) calls,\n")
             for fn_line in trait_fn_lines:
             out_c.write("\n\t" + struct_name + " ret = {\n")
             out_c.write("\t\t.this_arg = (void*) calls,\n")
             for fn_line in trait_fn_lines:


@@ -766,6 +1262,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 elif fn_line.group(2) == "free":
                     out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
                 else:
                 elif fn_line.group(2) == "free":
                     out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
                 else:

+                    clone_fns.add(struct_name + "_clone")

                     out_c.write("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
             for var_line in field_var_lines:
                 if var_line.group(1) in trait_structs:
                     out_c.write("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
             for var_line in field_var_lines:
                 if var_line.group(1) in trait_structs:


@@ -794,16 +1291,16 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
             out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
             out_c.write("\tjobject ret = (*env)->NewLocalRef(env, ((" + struct_name + "_JCalls*)val)->o);\n")
             out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
             out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
             out_c.write("\tjobject ret = (*env)->NewLocalRef(env, ((" + struct_name + "_JCalls*)val)->o);\n")

-            out_c.write("\tDO_ASSERT(ret != NULL);\n")
+            out_c.write("\tCHECK(ret != NULL);\n")

             out_c.write("\treturn ret;\n")
             out_c.write("}\n")
 
             out_c.write("\treturn ret;\n")
             out_c.write("}\n")
 

-            for fn_line in trait_fn_lines:
-                # For now, just disable enabling the _call_log - we don't know how to inverse-map String
-                is_log = fn_line.group(2) == "log" and struct_name == "LDKLogger"
-                if fn_line.group(2) != "free" and fn_line.group(2) != "clone" and fn_line.group(2) != "eq" and not is_log:
-                    dummy_line = fn_line.group(1) + struct_name + "_call_" + fn_line.group(2) + " " + struct_name + "* arg" + fn_line.group(4) + "\n"
-                    map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(arg_conv->" + fn_line.group(2) + ")(arg_conv->this_arg")
+        for fn_line in trait_fn_lines:
+            # For now, just disable enabling the _call_log - we don't know how to inverse-map String
+            is_log = fn_line.group(2) == "log" and struct_name == "LDKLogger"
+            if fn_line.group(2) != "free" and fn_line.group(2) != "clone" and fn_line.group(2) != "eq" and not is_log:
+                dummy_line = fn_line.group(1) + struct_name.replace("LDK", "") + "_" + fn_line.group(2) + " " + struct_name + "* this_arg" + fn_line.group(4) + "\n"
+                map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(this_arg_conv->" + fn_line.group(2) + ")(this_arg_conv->this_arg")

 
     out_c.write("""#include \"org_ldk_impl_bindings.h\"
 #include <rust_types.h>
 
     out_c.write("""#include \"org_ldk_impl_bindings.h\"
 #include <rust_types.h>


@@ -814,11 +1311,15 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
 
     if sys.argv[4] == "false":
         out_c.write("#define MALLOC(a, _) malloc(a)\n")
 
     if sys.argv[4] == "false":
         out_c.write("#define MALLOC(a, _) malloc(a)\n")

-        out_c.write("#define FREE free\n")
+        out_c.write("#define FREE(p) if ((p) > 1024) { free(p); }\n")

         out_c.write("#define DO_ASSERT(a) (void)(a)\n")
         out_c.write("#define DO_ASSERT(a) (void)(a)\n")

+        out_c.write("#define CHECK(a)\n")

     else:
         out_c.write("""#include <assert.h>
     else:
         out_c.write("""#include <assert.h>

+// Always run a, then assert it is true:

 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)

+// Assert a is true or do nothing
+#define CHECK(a) DO_ASSERT(a)

 
 // Running a leak check across all the allocations and frees of the JDK is a mess,
 // so instead we implement our own naive leak checker here, relying on the -wrap
 
 // Running a leak check across all the allocations and frees of the JDK is a mess,
 // so instead we implement our own naive leak checker here, relying on the -wrap


@@ -865,13 +1366,20 @@ static void alloc_freed(void* ptr) {
        allocation* p = NULL;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        allocation* it = allocation_ll;
        allocation* p = NULL;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        allocation* it = allocation_ll;

-       while (it->ptr != ptr) { p = it; it = it->next; }
+       while (it->ptr != ptr) {
+               p = it; it = it->next;
+               if (it == NULL) {
+                       fprintf(stderr, "Tried to free unknown pointer %p!\\n", ptr);
+                       return; // addrsan should catch malloc-unknown and print more info than we have
+               }
+       }

        if (p) { p->next = it->next; } else { allocation_ll = it->next; }
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(it->ptr == ptr);
        __real_free(it);
 }
 static void FREE(void* ptr) {
        if (p) { p->next = it->next; } else { allocation_ll = it->next; }
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(it->ptr == ptr);
        __real_free(it);
 }
 static void FREE(void* ptr) {

+       if ((long)ptr < 1024) return; // Rust loves to create pointers to the NULL page for dummys

        alloc_freed(ptr);
        __real_free(ptr);
 }
        alloc_freed(ptr);
        __real_free(ptr);
 }


@@ -937,6 +1445,7 @@ public class bindings {
        public static native byte[] get_u8_slice_bytes(long slice_ptr);
        public static native long bytes_to_u8_vec(byte[] bytes);
        public static native long new_txpointer_copy_data(byte[] txdata);
        public static native byte[] get_u8_slice_bytes(long slice_ptr);
        public static native long bytes_to_u8_vec(byte[] bytes);
        public static native long new_txpointer_copy_data(byte[] txdata);

+       public static native void txpointer_free(long ptr);

        public static native long vec_slice_len(long vec);
        public static native long new_empty_slice_vec();
 
        public static native long vec_slice_len(long vec);
        public static native long new_empty_slice_vec();
 


@@ -947,11 +1456,11 @@ static jmethodID slicedef_meth = NULL;
 static jclass slicedef_cls = NULL;
 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
        ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 static jclass slicedef_cls = NULL;
 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
        ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");

-       DO_ASSERT(ordinal_meth != NULL);
+       CHECK(ordinal_meth != NULL);

        slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
        slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");

-       DO_ASSERT(slicedef_meth != NULL);
+       CHECK(slicedef_meth != NULL);

        slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
        slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);

-       DO_ASSERT(slicedef_cls != NULL);
+       CHECK(slicedef_cls != NULL);

 }
 
 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
 }
 
 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {


@@ -985,12 +1494,18 @@ JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JN
        LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
        txdata->datalen = (*env)->GetArrayLength(env, bytes);
        txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
        LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
        txdata->datalen = (*env)->GetArrayLength(env, bytes);
        txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");

-       txdata->data_is_owned = true;
+       txdata->data_is_owned = false;

        (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
        return (long)txdata;
 }
        (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
        return (long)txdata;
 }

+JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
+       LDKTransaction *tx = (LDKTransaction*)ptr;
+       tx->data_is_owned = true;
+       Transaction_free(*tx);
+       FREE((void*)ptr);
+}

 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {

-        // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
+       // Check offsets of a few Vec types are all consistent as we're meant to be generic across types

        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");


@@ -999,7 +1514,7 @@ JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env
        return (long)vec->datalen;
 }
 JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * _env, jclass _b) {
        return (long)vec->datalen;
 }
 JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * _env, jclass _b) {

-        // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
+       // Check sizes of a few Vec types are all consistent as we're meant to be generic across types

        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
        _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");


@@ -1021,20 +1536,13 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
         out_java_struct.write("""package org.ldk.structs;
 import java.util.LinkedList;
 class CommonBase {
         out_java_struct.write("""package org.ldk.structs;
 import java.util.LinkedList;
 class CommonBase {

-       final long ptr;
+       long ptr;

        LinkedList<Object> ptrs_to = new LinkedList();
        protected CommonBase(long ptr) { this.ptr = ptr; }
        public long _test_only_get_ptr() { return this.ptr; }
 }
 """)
 
        LinkedList<Object> ptrs_to = new LinkedList();
        protected CommonBase(long ptr) { this.ptr = ptr; }
        public long _test_only_get_ptr() { return this.ptr; }
 }
 """)
 

-    # XXX: Temporarily write out a manual SecretKey_new() for testing, we should auto-gen this kind of thing
-    out_java.write("\tpublic static native long LDKSecretKey_new();\n\n") # TODO: rm me
-    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_LDKSecretKey_1new(JNIEnv * _env, jclass _b) {\n") # TODO: rm me
-    out_c.write("\tLDKSecretKey* key = (LDKSecretKey*)MALLOC(sizeof(LDKSecretKey), \"LDKSecretKey\");\n") # TODO: rm me
-    out_c.write("\treturn (long)key;\n") # TODO: rm me
-    out_c.write("}\n") # TODO: rm me
-

     in_block_comment = False
     cur_block_obj = None
 
     in_block_comment = False
     cur_block_obj = None
 


@@ -1125,14 +1633,19 @@ class CommonBase {
                 if is_opaque:
                     opaque_structs.add(struct_name)
                     with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_struct:
                 if is_opaque:
                     opaque_structs.add(struct_name)
                     with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_struct:

-                        out_java_struct.write("package org.ldk.structs;\n\n")
-                        out_java_struct.write("import org.ldk.impl.bindings;\n")
-                        out_java_struct.write("import org.ldk.enums.*;\n\n")
-                        out_java_struct.write("public class " + struct_name.replace("LDK","") + " extends CommonBase {\n")
+                        out_java_struct.write(hu_struct_file_prefix)
+                        out_java_struct.write("public class " + struct_name.replace("LDK","") + " extends CommonBase")
+                        if struct_name.startswith("LDKLocked"):
+                            out_java_struct.write(" implements AutoCloseable")
+                        out_java_struct.write(" {\n")

                         out_java_struct.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
                         out_java_struct.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")

-                        out_java_struct.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
-                        out_java_struct.write("\tprotected void finalize() throws Throwable {\n")
-                        out_java_struct.write("\t\tbindings." + struct_name.replace("LDK","") + "_free(ptr); super.finalize();\n")
+                        if struct_name.startswith("LDKLocked"):
+                            out_java_struct.write("\t@Override public void close() {\n")
+                        else:
+                            out_java_struct.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
+                            out_java_struct.write("\tprotected void finalize() throws Throwable {\n")
+                            out_java_struct.write("\t\tsuper.finalize();\n")
+                        out_java_struct.write("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")

                         out_java_struct.write("\t}\n\n")
                 elif result_contents is not None:
                     result_templ_structs.add(struct_name)
                         out_java_struct.write("\t}\n\n")
                 elif result_contents is not None:
                     result_templ_structs.add(struct_name)


@@ -1147,6 +1660,7 @@ class CommonBase {
                 elif is_tuple:
                     out_java.write("\tpublic static native long " + struct_name + "_new(")
                     out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *_env, jclass _b")
                 elif is_tuple:
                     out_java.write("\tpublic static native long " + struct_name + "_new(")
                     out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *_env, jclass _b")

+                    ty_list = []

                     for idx, line in enumerate(field_lines):
                         if idx != 0 and idx < len(field_lines) - 2:
                             ty_info = java_c_types(line.strip(';'), None)
                     for idx, line in enumerate(field_lines):
                         if idx != 0 and idx < len(field_lines) - 2:
                             ty_info = java_c_types(line.strip(';'), None)


@@ -1155,18 +1669,22 @@ class CommonBase {
                             e = chr(ord('a') + idx - 1)
                             out_java.write(ty_info.java_ty + " " + e)
                             out_c.write(", " + ty_info.c_ty + " " + e)
                             e = chr(ord('a') + idx - 1)
                             out_java.write(ty_info.java_ty + " " + e)
                             out_c.write(", " + ty_info.c_ty + " " + e)

+                            ty_list.append(ty_info)
+                    tuple_types[struct_name] = (ty_list, struct_name)

                     out_java.write(");\n")
                     out_c.write(") {\n")
                     out_c.write("\t" + struct_name + "* ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
                     for idx, line in enumerate(field_lines):
                         if idx != 0 and idx < len(field_lines) - 2:
                     out_java.write(");\n")
                     out_c.write(") {\n")
                     out_c.write("\t" + struct_name + "* ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
                     for idx, line in enumerate(field_lines):
                         if idx != 0 and idx < len(field_lines) - 2:

-                            ty_info = map_type(line.strip(';'), False, None, False)
+                            ty_info = map_type(line.strip(';'), False, None, False, False)

                             e = chr(ord('a') + idx - 1)
                             if ty_info.arg_conv is not None:
                                 out_c.write("\t" + ty_info.arg_conv.replace("\n", "\n\t"))
                                 out_c.write("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
                             else:
                                 out_c.write("\tret->" + e + " = " + e + ";\n")
                             e = chr(ord('a') + idx - 1)
                             if ty_info.arg_conv is not None:
                                 out_c.write("\t" + ty_info.arg_conv.replace("\n", "\n\t"))
                                 out_c.write("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
                             else:
                                 out_c.write("\tret->" + e + " = " + e + ";\n")

+                            if ty_info.arg_conv_cleanup is not None:
+                                out_c.write("\t//TODO: Really need to call " + ty_info.arg_conv_cleanup + " here\n")

                     out_c.write("\treturn (long)ret;\n")
                     out_c.write("}\n")
                 elif vec_ty is not None:
                     out_c.write("\treturn (long)ret;\n")
                     out_c.write("}\n")
                 elif vec_ty is not None:


@@ -1181,7 +1699,7 @@ class CommonBase {
                         out_c.write("\tjlongArray ret = (*env)->NewLongArray(env, vec->datalen);\n")
                         out_c.write("\tjlong *ret_elems = (*env)->GetPrimitiveArrayCritical(env, ret, NULL);\n")
                         out_c.write("\tfor (size_t i = 0; i < vec->datalen; i++) {\n")
                         out_c.write("\tjlongArray ret = (*env)->NewLongArray(env, vec->datalen);\n")
                         out_c.write("\tjlong *ret_elems = (*env)->GetPrimitiveArrayCritical(env, ret, NULL);\n")
                         out_c.write("\tfor (size_t i = 0; i < vec->datalen; i++) {\n")

-                        out_c.write("\t\tDO_ASSERT((((long)vec->data[i].inner) & 1) == 0);\n")
+                        out_c.write("\t\tCHECK((((long)vec->data[i].inner) & 1) == 0);\n")

                         out_c.write("\t\tret_elems[i] = (long)vec->data[i].inner | (vec->data[i].is_owned ? 1 : 0);\n")
                         out_c.write("\t}\n")
                         out_c.write("\t(*env)->ReleasePrimitiveArrayCritical(env, ret, ret_elems, 0);\n")
                         out_c.write("\t\tret_elems[i] = (long)vec->data[i].inner | (vec->data[i].is_owned ? 1 : 0);\n")
                         out_c.write("\t}\n")
                         out_c.write("\t(*env)->ReleasePrimitiveArrayCritical(env, ret, ret_elems, 0);\n")


@@ -1190,7 +1708,7 @@ class CommonBase {
                         out_c.write("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")
                     out_c.write("}\n")
 
                         out_c.write("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")
                     out_c.write("}\n")
 

-                    ty_info = map_type(vec_ty + " arr_elem", False, None, False)
+                    ty_info = map_type(vec_ty + " arr_elem", False, None, False, False)

                     if len(ty_info.java_fn_ty_arg) == 1: # ie we're a primitive of some form
                         out_java.write("\tpublic static native long " + struct_name + "_new(" + ty_info.java_ty + "[] elems);\n")
                         out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *env, jclass _b, j" + ty_info.java_ty + "Array elems){\n")
                     if len(ty_info.java_fn_ty_arg) == 1: # ie we're a primitive of some form
                         out_java.write("\tpublic static native long " + struct_name + "_new(" + ty_info.java_ty + "[] elems);\n")
                         out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *env, jclass _b, j" + ty_info.java_ty + "Array elems){\n")


@@ -1206,6 +1724,7 @@ class CommonBase {
                             out_c.write("\t\t\t" + ty_info.c_ty + " arr_elem = java_elems[i];\n")
                             out_c.write("\t\t\t" + ty_info.arg_conv.replace("\n", "\n\t\t\t") + "\n")
                             out_c.write("\t\t\tret->data[i] = " + ty_info.arg_conv_name + ";\n")
                             out_c.write("\t\t\t" + ty_info.c_ty + " arr_elem = java_elems[i];\n")
                             out_c.write("\t\t\t" + ty_info.arg_conv.replace("\n", "\n\t\t\t") + "\n")
                             out_c.write("\t\t\tret->data[i] = " + ty_info.arg_conv_name + ";\n")

+                            assert ty_info.arg_conv_cleanup is None

                         else:
                             out_c.write("\t\t\tret->data[i] = java_elems[i];\n")
                         out_c.write("\t\t}\n")
                         else:
                             out_c.write("\t\t\tret->data[i] = java_elems[i];\n")
                         out_c.write("\t\t}\n")


@@ -1227,6 +1746,25 @@ class CommonBase {
                 elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)
                 elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)

+                elif struct_name == "LDKTxOut":
+                    with open(sys.argv[3] + "/structs/TxOut.java", "w") as out_java_struct:
+                        out_java_struct.write(hu_struct_file_prefix)
+                        out_java_struct.write("public class TxOut extends CommonBase{\n")
+                        out_java_struct.write("\tTxOut(java.lang.Object _dummy, long ptr) { super(ptr); }\n")
+                        out_java_struct.write("\tlong to_c_ptr() { return 0; }\n")
+                        # TODO: TxOut body
+                        out_java_struct.write("}")
+                elif struct_name == "LDKTransaction":
+                    with open(sys.argv[3] + "/structs/Transaction.java", "w") as out_java_struct:
+                        out_java_struct.write(hu_struct_file_prefix)
+                        out_java_struct.write("public class Transaction extends CommonBase{\n")
+                        out_java_struct.write("\tTransaction(java.lang.Object _dummy, long ptr) { super(ptr); }\n")
+                        out_java_struct.write("\tpublic Transaction(byte[] data) { super(bindings.new_txpointer_copy_data(data)); }\n")
+                        out_java_struct.write("\t@Override public void finalize() throws Throwable { super.finalize(); bindings.txpointer_free(ptr); }\n")
+                        # TODO: Transaction body
+                        out_java_struct.write("}")
+                else:
+                    pass # Everything remaining is a byte[] or some form

                 cur_block_obj = None
         else:
             fn_ptr = fn_ptr_regex.match(line)
                 cur_block_obj = None
         else:
             fn_ptr = fn_ptr_regex.match(line)


@@ -1248,28 +1786,109 @@ class CommonBase {
                 cur_block_obj = line
             elif line.startswith("typedef "):
                 alias_match =  struct_alias_regex.match(line)
                 cur_block_obj = line
             elif line.startswith("typedef "):
                 alias_match =  struct_alias_regex.match(line)

-                if alias_match.group(1) in result_templ_structs:
-                    out_java.write("\tpublic static native boolean " + alias_match.group(2) + "_result_ok(long arg);\n")
-                    out_java.write("\tpublic static native long " + alias_match.group(2) + "_get_inner(long arg);\n")
-                    out_c.write("JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1result_1ok (JNIEnv * env, jclass _a, jlong arg) {\n")
-                    out_c.write("\treturn ((" + alias_match.group(2) + "*)arg)->result_ok;\n")
-                    out_c.write("}\n")
-                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1inner (JNIEnv * env, jclass _a, jlong arg) {\n")
-                    contents_ty = alias_match.group(1).replace("LDKCResultTempl", "LDKCResultPtr")
-                    res_ty, err_ty = result_ptr_struct_items[contents_ty]
-                    out_c.write("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
-                    out_c.write("\tif (val->result_ok) {\n")
-                    if res_ty not in opaque_structs:
-                        out_c.write("\t\treturn (long)val->contents.result;\n")
-                    else:
-                        out_c.write("\t\treturn (long)(val->contents.result->inner) | (val->contents.result->is_owned ? 1 : 0);\n")
-                    out_c.write("\t} else {\n")
-                    if err_ty not in opaque_structs:
-                        out_c.write("\t\treturn (long)val->contents.err;\n")
-                    else:
-                        out_c.write("\t\treturn (long)(val->contents.err->inner) | (val->contents.err->is_owned ? 1 : 0);\n")
-                    out_c.write("\t}\n}\n")
-                pass
+                if alias_match.group(1) in tuple_types:
+                    tuple_types[alias_match.group(2)] = (tuple_types[alias_match.group(1)][0], alias_match.group(2))
+                    tuple_types[alias_match.group(1)] = (tuple_types[alias_match.group(1)][0], alias_match.group(2))
+                    for idx, ty_info in enumerate(tuple_types[alias_match.group(1)][0]):
+                        e = chr(ord('a') + idx)
+                        out_java.write("\tpublic static native " + ty_info.java_ty + " " + alias_match.group(2) + "_get_" + e + "(long ptr);\n")
+                        # XXX: Write C method!
+                elif alias_match.group(1) in result_templ_structs:
+                    result_types.add(alias_match.group(2))
+                    human_ty = alias_match.group(2).replace("LDKCResult", "Result")
+                    with open(sys.argv[3] + "/structs/" + human_ty + ".java", "w") as out_java_struct:
+                        out_java_struct.write(hu_struct_file_prefix)
+                        out_java_struct.write("public class " + human_ty + " extends CommonBase {\n")
+                        out_java_struct.write("\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n")
+                        out_java_struct.write("\tprotected void finalize() throws Throwable {\n")
+                        out_java_struct.write("\t\tif (ptr != 0) { bindings." + alias_match.group(2).replace("LDK","") + "_free(ptr); } super.finalize();\n")
+                        out_java_struct.write("\t}\n\n")
+                        out_java_struct.write("\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n")
+                        out_java_struct.write("\t\tif (bindings." + alias_match.group(2) + "_result_ok(ptr)) {\n")
+                        out_java_struct.write("\t\t\treturn new " + human_ty + "_OK(null, ptr);\n")
+                        out_java_struct.write("\t\t} else {\n")
+                        out_java_struct.write("\t\t\treturn new " + human_ty + "_Err(null, ptr);\n")
+                        out_java_struct.write("\t\t}\n")
+                        out_java_struct.write("\t}\n")
+
+                        contents_ty = alias_match.group(1).replace("LDKCResultTempl", "LDKCResultPtr")
+                        res_ty, err_ty = result_ptr_struct_items[contents_ty]
+                        res_map = map_type(res_ty + " res", True, None, False, True)
+                        err_map = map_type(err_ty + " err", True, None, False, True)
+
+                        out_java.write("\tpublic static native boolean " + alias_match.group(2) + "_result_ok(long arg);\n")
+                        out_c.write("JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1result_1ok (JNIEnv * env, jclass _a, jlong arg) {\n")
+                        out_c.write("\treturn ((" + alias_match.group(2) + "*)arg)->result_ok;\n")
+                        out_c.write("}\n")
+
+                        out_java.write("\tpublic static native " + res_map.java_ty + " " + alias_match.group(2) + "_get_ok(long arg);\n")
+                        out_c.write("JNIEXPORT " + res_map.c_ty + " JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1ok (JNIEnv * _env, jclass _a, jlong arg) {\n")
+                        out_c.write("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
+                        out_c.write("\tCHECK(val->result_ok);\n\t")
+                        out_java_struct.write("\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n")
+                        if res_map.ret_conv is not None:
+                            out_c.write(res_map.ret_conv[0].replace("\n", "\n\t") + "(*val->contents.result)")
+                            out_c.write(res_map.ret_conv[1].replace("\n", "\n\t") + "\n\treturn " + res_map.ret_conv_name)
+                        else:
+                            out_c.write("return *val->contents.result")
+                        out_c.write(";\n}\n")
+
+                        out_java_struct.write("\t\tpublic final " + res_map.java_hu_ty + " res;\n")
+                        out_java_struct.write("\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n")
+                        out_java_struct.write("\t\t\tsuper(_dummy, ptr);\n")
+                        if res_map.to_hu_conv is not None:
+                            out_java_struct.write("\t\t\t" + res_map.java_ty + " res = bindings." + alias_match.group(2) + "_get_ok(ptr);\n")
+                            out_java_struct.write("\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t"))
+                            out_java_struct.write("\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n")
+                        else:
+                            out_java_struct.write("\t\t\tthis.res = bindings." + alias_match.group(2) + "_get_ok(ptr);\n")
+                        out_java_struct.write("\t\t}\n")
+                        if alias_match.group(2).startswith("LDKCResult_None"):
+                            out_java_struct.write("\t\tpublic " + human_ty + "_OK() {\n\t\t\tthis(null, bindings.C" + human_ty + "_ok());\n")
+                        else:
+                            out_java_struct.write("\t\tpublic " + human_ty + "_OK(" + res_map.java_hu_ty + " res) {\n")
+                            if res_map.from_hu_conv is not None:
+                                out_java_struct.write("\t\t\tthis(null, bindings.C" + human_ty + "_ok(" + res_map.from_hu_conv[0] + "));\n")
+                                if res_map.from_hu_conv[1] != "":
+                                    out_java_struct.write("\t\t\t" + res_map.from_hu_conv[1] + ";\n")
+                            else:
+                                out_java_struct.write("\t\t\tthis(null, bindings.C" + human_ty + "_ok(res));\n")
+                        out_java_struct.write("\t\t}\n\t}\n\n")
+
+                        out_java.write("\tpublic static native " + err_map.java_ty + " " + alias_match.group(2) + "_get_err(long arg);\n")
+                        out_c.write("JNIEXPORT " + err_map.c_ty + " JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1err (JNIEnv * _env, jclass _a, jlong arg) {\n")
+                        out_c.write("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
+                        out_c.write("\tCHECK(!val->result_ok);\n\t")
+                        out_java_struct.write("\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n")
+                        if err_map.ret_conv is not None:
+                            out_c.write(err_map.ret_conv[0].replace("\n", "\n\t") + "(*val->contents.err)")
+                            out_c.write(err_map.ret_conv[1].replace("\n", "\n\t") + "\n\treturn " + err_map.ret_conv_name)
+                        else:
+                            out_c.write("return *val->contents.err")
+                        out_c.write(";\n}\n")
+
+                        out_java_struct.write("\t\tpublic final " + err_map.java_hu_ty + " err;\n")
+                        out_java_struct.write("\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n")
+                        out_java_struct.write("\t\t\tsuper(_dummy, ptr);\n")
+                        if err_map.to_hu_conv is not None:
+                            out_java_struct.write("\t\t\t" + err_map.java_ty + " err = bindings." + alias_match.group(2) + "_get_err(ptr);\n")
+                            out_java_struct.write("\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t"))
+                            out_java_struct.write("\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n")
+                        else:
+                            out_java_struct.write("\t\t\tthis.err = bindings." + alias_match.group(2) + "_get_err(ptr);\n")
+                        out_java_struct.write("\t\t}\n")
+
+                        if alias_match.group(2).endswith("NoneZ"):
+                            out_java_struct.write("\t\tpublic " + human_ty + "_Err() {\n\t\t\tthis(null, bindings.C" + human_ty + "_err());\n")
+                        else:
+                            out_java_struct.write("\t\tpublic " + human_ty + "_Err(" + err_map.java_hu_ty + " err) {\n")
+                            if err_map.from_hu_conv is not None:
+                                out_java_struct.write("\t\t\tthis(null, bindings.C" + human_ty + "_err(" + err_map.from_hu_conv[0] + "));\n")
+                                if err_map.from_hu_conv[1] != "":
+                                    out_java_struct.write("\t\t\t" + err_map.from_hu_conv[1] + ";\n")
+                            else:
+                                out_java_struct.write("\t\t\tthis(null, bindings.C" + human_ty + "_err(err));\n")
+                        out_java_struct.write("\t\t}\n\t}\n}\n")

             elif fn_ptr is not None:
                 map_fn(line, fn_ptr, None, None)
             elif fn_ret_arr is not None:
             elif fn_ptr is not None:
                 map_fn(line, fn_ptr, None, None)
             elif fn_ret_arr is not None:


@@ -1286,3 +1905,6 @@ class CommonBase {
     for struct_name in opaque_structs:
         with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "a") as out_java_struct:
             out_java_struct.write("}\n")
     for struct_name in opaque_structs:
         with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "a") as out_java_struct:
             out_java_struct.write("}\n")

+    for struct_name in trait_structs:
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "a") as out_java_struct:
+            out_java_struct.write("}\n")