Drop the _call insertion
[ldk-java] / genbindings.py
index 24d3df5940d47da822e69d352edf28ea879727a8..73ef5f92d42d2360debe5330f1492eb4b21e5de4 100755 (executable)
@@ -2,7 +2,7 @@
 import sys, re
 
 if len(sys.argv) != 6:
-    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/enums/ /path/to/bindings/output.c debug")
+    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/ /path/to/bindings/output.c debug")
     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 
@@ -19,7 +19,7 @@ class TypeInfo:
         self.arr_access = arr_access
 
 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):
         assert(ty_info.c_ty is not None)
         assert(ty_info.java_ty is not None)
         assert(arg_name is not None)
@@ -31,6 +31,7 @@ class ConvInfo:
         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
 
@@ -93,7 +94,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 lastund = True
         return (ret + lastchar.lower()).strip("_")
 
-    var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([0-9]*)\]")
+    var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([a-z0-9]*)\]")
     var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
     def java_c_types(fn_arg, ret_arr_len):
         fn_arg = fn_arg.strip()
@@ -118,10 +119,26 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             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("LDKSecretKey"):
+            fn_arg = "uint8_t (*" + fn_arg[13:] + ")[32]"
+            assert var_is_arr_regex.match(fn_arg[8:])
+            rust_obj = "LDKSecretKey"
+            arr_access = "bytes"
+        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"
+            arr_access = "compact_form"
+        if 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"
+        if 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"
 
         if fn_arg.startswith("void"):
             java_ty = "void"
@@ -206,7 +223,8 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         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)
 
         if ty_info.c_ty.endswith("Array"):
             arr_len = ty_info.arr_len
@@ -216,19 +234,30 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 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)
+            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);"
+                arr_access = "." + ty_info.arr_access
+                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 + ");")
+            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" + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
-                arr_access = ("*", "")
+                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",
-                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")
+                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")
         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:
@@ -236,20 +265,24 @@ 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);"
-                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:
+                    if (ty_info.rust_obj.replace("LDK", "") + "_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.rust_obj.replace("LDK", "") + "_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",
+                            arg_conv_cleanup = None,
                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
                             ret_conv_name = ty_info.var_name + "_conv")
                     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 = ";\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"
                         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"
@@ -257,7 +290,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         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 + "}"
                         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_name = ty_info.var_name + "_ref")
                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
@@ -269,48 +302,47 @@ 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,
-                            arg_conv = base_conv,
-                            arg_conv_name = ty_info.var_name + "_conv",
+                            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")
                     if ty_info.rust_obj != "LDKu8slice":
                         # 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 + ");";
                     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 = 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")
                 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",
+                            arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
                             ret_conv = None, ret_conv_name = None) # 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 + ";",
-                        arg_conv_name = ty_info.var_name + "_conv",
+                        arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
             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)
+                    arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None, 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,
+                    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")
             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)
         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);
                 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",
+                    arg_conv_name = "arg_conv", arg_conv_cleanup = None,
                     ret_conv = None, ret_conv_name = None)
             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)
         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:
@@ -318,7 +350,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     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",
+                            arg_conv_name = "ret", arg_conv_cleanup = None,
                             ret_conv = ("jclass ret = " + ty_info.rust_obj + "_to_java(_env, ", ");"), ret_conv_name = "ret")
                     if ty_info.rust_obj in opaque_structs:
                         # If we're returning a newly-allocated struct, we don't want Rust to ever
@@ -328,27 +360,31 @@ 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)",
-                            arg_conv = None, arg_conv_name = None)
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None)
                     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)
                 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)
             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)
 
     def map_fn(line, re_match, ret_arr_len, c_call_string):
         out_java.write("\t// " + line)
         out_java.write("\tpublic static native ")
         out_c.write("JNIEXPORT ")
 
+        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.print_ty()
+
         if ret_info.ret_conv is not None:
             ret_conv_pfx, ret_conv_sfx = ret_info.ret_conv
 
@@ -356,28 +392,72 @@ 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 = []
+        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
         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, re_match.group(2).endswith("_free"))
+            arg_conv_info = map_type(arg, False, None, is_free)
             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":
+                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:
+                args_known = False
             arg_names.append(arg_conv_info)
 
+        out_java_struct = None
+        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.write("\tpublic ")
+                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 + "(")
+                else:
+                    out_java_struct.write(ret_info.java_ty + " " + meth_n + "(")
+                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)
+                        else:
+                            out_java_struct.write(arg.java_ty + " " + arg.arg_name)
+
+
         out_java.write(");\n")
         out_c.write(") {\n")
+        if out_java_struct is not None:
+            out_java_struct.write(") {\n")
 
         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:
-            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:
-            out_c.write("\treturn ");
+            out_c.write("\t")
 
         if c_call_string is None:
             out_c.write(re_match.group(2) + "(")
@@ -393,13 +473,61 @@ 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("\n\treturn " + ret_info.ret_conv_name + ";")
         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")
+            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:
+                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(", ")
+                if info.arg_name == "this_arg":
+                    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 + " == null ? 0 : " + info.arg_name + ".ptr & ~1")
+                elif info.passed_as_ptr and info.rust_obj in trait_structs:
+                    out_java_struct.write(info.arg_name + " == null ? 0 : " + info.arg_name + ".ptr")
+                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")
+
+            for info in arg_names:
+                if info.arg_name == "this_arg":
+                    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")
+
+            if 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()
 
     def map_unitary_enum(struct_name, field_lines):
-        with open(sys.argv[3] + "/" + struct_name + ".java", "w") as out_java_enum:
+        with open(sys.argv[3] + "/enums/" + struct_name + ".java", "w") as out_java_enum:
             out_java_enum.write("package org.ldk.enums;\n\n")
             unitary_enums.add(struct_name)
             out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
@@ -433,12 +561,12 @@ 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("\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")
-                    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")
@@ -499,9 +627,9 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 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("\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("\tDO_ASSERT(" + struct_name + "_" + var_name + "_meth != NULL);\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")
@@ -529,172 +657,197 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write("\t}\n}\n")
 
     def map_trait(struct_name, field_var_lines, trait_fn_lines):
-        out_c.write("typedef struct " + struct_name + "_JCalls {\n")
-        out_c.write("\tatomic_size_t refcnt;\n")
-        out_c.write("\tJavaVM *vm;\n")
-        out_c.write("\tjweak o;\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
-        for fn_line in trait_fn_lines:
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
-        out_c.write("} " + struct_name + "_JCalls;\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":
-                ret_ty_info = java_c_types(fn_line.group(1), None)
-
-                out_java.write("\t\t " + ret_ty_info.java_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:
-                    out_c.write("const void* this_arg")
-                else:
-                    out_c.write("void* this_arg")
-
-                arg_names = []
-                for idx, arg in enumerate(fn_line.group(4).split(',')):
-                    if arg == "":
-                        continue
-                    if idx >= 2:
-                        out_java.write(", ")
-                    out_c.write(", ")
-                    arg_conv_info = map_type(arg, True, None, False)
-                    out_c.write(arg.strip())
-                    out_java.write(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")
-                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")
-
-                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(arg_info.arg_name)
-                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
-
-                out_c.write("\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tDO_ASSERT(obj != NULL);\n")
-                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")
-                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")
-                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");
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_trait:
+            out_c.write("typedef struct " + struct_name + "_JCalls {\n")
+            out_c.write("\tatomic_size_t refcnt;\n")
+            out_c.write("\tJavaVM *vm;\n")
+            out_c.write("\tjweak o;\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
+            for fn_line in trait_fn_lines:
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    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("import org.ldk.enums.*;\n\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")
+            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))
+            out_java_trait.write(") {\n")
+            out_java_trait.write("\t\tsuper(bindings." + struct_name + "_new(arg")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    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}\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}\n\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":
+                    ret_ty_info = java_c_types(fn_line.group(1), None)
+
+                    out_java.write("\t\t " + ret_ty_info.java_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:
+                        out_c.write("const void* this_arg")
+                    else:
+                        out_c.write("void* this_arg")
+
+                    arg_names = []
+                    for idx, arg in enumerate(fn_line.group(4).split(',')):
+                        if arg == "":
+                            continue
+                        if idx >= 2:
+                            out_java.write(", ")
+                        out_c.write(", ")
+                        arg_conv_info = map_type(arg, True, None, False)
+                        out_c.write(arg.strip())
+                        out_java.write(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)
 
-                for arg_info in arg_names:
-                    if arg_info.ret_conv is not None:
-                        out_c.write(", " + arg_info.ret_conv_name)
+                    out_java.write(");\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")
+
+                    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(arg_info.arg_name)
+                            out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\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"):
+                        assert(ret_ty_info.c_ty == "jbyteArray")
+                        out_c.write("\tjbyteArray jret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    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")
                     else:
-                        out_c.write(", " + arg_info.arg_name)
-                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.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")
-            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")
-                out_c.write("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
-                out_c.write("\t\tJNIEnv *env;\n")
-                out_c.write("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\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")
-
-        # 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")
-        out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
-        out_c.write("\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
-        out_c.write("\treturn (void*) this_arg;\n")
-        out_c.write("}\n")
+                        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");
 
-        out_java.write("\t}\n")
+                    for arg_info in 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)
+                    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("\tCHECK((*env)->GetArrayLength(env, jret) == " + ret_ty_info.arr_len + ");\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")
 
-        out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
-        out_c.write("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
-                out_c.write(", jobject " + var_line.group(2))
-        out_java.write(");\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")
+                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")
+                    out_c.write("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
+                    out_c.write("\t\tJNIEnv *env;\n")
+                    out_c.write("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\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")
 
-        out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
-        out_c.write("\tDO_ASSERT(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("\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\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("\n\t" + struct_name + " ret = {\n")
-        out_c.write("\t\t.this_arg = (void*) calls,\n")
-        for fn_line in trait_fn_lines:
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                out_c.write("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
-            elif fn_line.group(2) == "free":
-                out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
-            else:
-                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." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
-        out_c.write("\t};\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
-        out_c.write("\treturn ret;\n")
-        out_c.write("}\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")
+            out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+            out_c.write("\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
+            out_c.write("\treturn (void*) this_arg;\n")
+            out_c.write("}\n")
 
-        out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write(", jobject " + var_line.group(2))
-        out_c.write(") {\n")
-        out_c.write("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
-        out_c.write("\t*res_ptr = " + struct_name + "_init(env, _a, o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write(", " + var_line.group(2))
-        out_c.write(");\n")
-        out_c.write("\treturn (long)res_ptr;\n")
-        out_c.write("}\n")
+            out_java.write("\t}\n")
+
+            out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
+            out_c.write("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
+                    out_c.write(", jobject " + var_line.group(2))
+            out_java.write(");\n")
+            out_c.write(") {\n")
+
+            out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\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("\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\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("\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:
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    out_c.write("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
+                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." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
+            out_c.write("\t};\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
+            out_c.write("\treturn ret;\n")
+            out_c.write("}\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("\treturn ret;\n")
-        out_c.write("}\n")
+            out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write(", jobject " + var_line.group(2))
+            out_c.write(") {\n")
+            out_c.write("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+            out_c.write("\t*res_ptr = " + struct_name + "_init(env, _a, o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write(", " + var_line.group(2))
+            out_c.write(");\n")
+            out_c.write("\treturn (long)res_ptr;\n")
+            out_c.write("}\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("\tCHECK(ret != NULL);\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")
+                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>
@@ -707,9 +860,13 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write("#define MALLOC(a, _) malloc(a)\n")
         out_c.write("#define FREE free\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>
+// Always run a, then assert it is true:
 #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
@@ -838,11 +995,11 @@ 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");
-       DO_ASSERT(ordinal_meth != NULL);
+       CHECK(ordinal_meth != NULL);
        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);
-       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) {
@@ -908,19 +1065,20 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
 
 """)
 
-    # 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
+    with open(sys.argv[3] + "/structs/CommonBase.java", "a") as out_java_struct:
+        out_java_struct.write("""package org.ldk.structs;
+import java.util.LinkedList;
+class CommonBase {
+       final long ptr;
+       LinkedList<Object> ptrs_to = new LinkedList();
+       protected CommonBase(long ptr) { this.ptr = ptr; }
+       public long _test_only_get_ptr() { return this.ptr; }
+}
+""")
 
     in_block_comment = False
     cur_block_obj = None
 
-    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]*)\((.*)\);$")
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
     line_indicates_result_regex = re.compile("^   (LDKCResultPtr_[A-Za-z_0-9]*) contents;$")
@@ -1007,6 +1165,16 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
 
                 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("\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")
+                        out_java_struct.write("\t}\n\n")
                 elif result_contents is not None:
                     result_templ_structs.add(struct_name)
                     assert result_contents in result_ptr_struct_items
@@ -1040,6 +1208,7 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                                 out_c.write("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
                             else:
                                 out_c.write("\tret->" + e + " = " + e + ";\n")
+                            assert ty_info.arg_conv_cleanup is None
                     out_c.write("\treturn (long)ret;\n")
                     out_c.write("}\n")
                 elif vec_ty is not None:
@@ -1054,7 +1223,7 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                         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")
@@ -1079,6 +1248,7 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                             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")
@@ -1156,3 +1326,9 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                 assert(line == "\n")
 
     out_java.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")