Update Human object test to use SocketDescriptor traits (which worked the first time!)

[ldk-java] / genbindings.py

diff --git a/genbindings.py b/genbindings.py
index 78bb2ad875d8761006b612b13758df3254f1202a..3f7a12ee23d402b00044cd967b4c27c308af2006 100755 (executable)
--- a/genbindings.py
+++ b/genbindings.py
@@ -1,145 +1,515 @@
 #!/usr/bin/env python3
 import sys, re
 
 #!/usr/bin/env python3
 import sys, re
 

-if len(sys.argv) != 5:
-    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/output.c debug")
+if len(sys.argv) != 6:
+    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)
 
     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
+"""
+
+c_file_pfx = """#include \"org_ldk_impl_bindings.h\"
+#include <rust_types.h>
+#include <lightning.h>
+#include <string.h>
+#include <stdatomic.h>
+"""
+
+if sys.argv[5] == "false":
+    c_file_pfx = c_file_pfx + """#define MALLOC(a, _) malloc(a)
+#define FREE(p) if ((long)(p) > 1024) { free(p); }
+#define DO_ASSERT(a) (void)(a)
+#define CHECK(a)
+"""
+else:
+    c_file_pfx = c_file_pfx + """#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
+// linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
+// and free'd in Rust or C across the generated bindings shared library.
+#include <threads.h>
+#include <execinfo.h>
+#include <unistd.h>
+static mtx_t allocation_mtx;
+
+void __attribute__((constructor)) init_mtx() {
+       DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
+}
+
+#define BT_MAX 128
+typedef struct allocation {
+       struct allocation* next;
+       void* ptr;
+       const char* struct_name;
+       void* bt[BT_MAX];
+       int bt_len;
+} allocation;
+static allocation* allocation_ll = NULL;
+
+void* __real_malloc(size_t len);
+void* __real_calloc(size_t nmemb, size_t len);
+static void new_allocation(void* res, const char* struct_name) {
+       allocation* new_alloc = __real_malloc(sizeof(allocation));
+       new_alloc->ptr = res;
+       new_alloc->struct_name = struct_name;
+       new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
+       DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
+       new_alloc->next = allocation_ll;
+       allocation_ll = new_alloc;
+       DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
+}
+static void* MALLOC(size_t len, const char* struct_name) {
+       void* res = __real_malloc(len);
+       new_allocation(res, struct_name);
+       return res;
+}
+void __real_free(void* ptr);
+static void alloc_freed(void* ptr) {
+       allocation* p = NULL;
+       DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
+       allocation* it = allocation_ll;
+       while (it->ptr != ptr) {
+               p = it; it = it->next;
+               if (it == NULL) {
+                       fprintf(stderr, "Tried to free unknown pointer %p at:\\n", ptr);
+                       void* bt[BT_MAX];
+                       int bt_len = backtrace(bt, BT_MAX);
+                       backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
+                       fprintf(stderr, "\\n\\n");
+                       DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
+                       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 ((long)ptr < 1024) return; // Rust loves to create pointers to the NULL page for dummys
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __wrap_malloc(size_t len) {
+       void* res = __real_malloc(len);
+       new_allocation(res, "malloc call");
+       return res;
+}
+void* __wrap_calloc(size_t nmemb, size_t len) {
+       void* res = __real_calloc(nmemb, len);
+       new_allocation(res, "calloc call");
+       return res;
+}
+void __wrap_free(void* ptr) {
+       if (ptr == NULL) return;
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __real_realloc(void* ptr, size_t newlen);
+void* __wrap_realloc(void* ptr, size_t len) {
+       if (ptr != NULL) alloc_freed(ptr);
+       void* res = __real_realloc(ptr, len);
+       new_allocation(res, "realloc call");
+       return res;
+}
+void __wrap_reallocarray(void* ptr, size_t new_sz) {
+       // Rust doesn't seem to use reallocarray currently
+       assert(false);
+}
+
+void __attribute__((destructor)) check_leaks() {
+       for (allocation* a = allocation_ll; a != NULL; a = a->next) {
+               fprintf(stderr, "%s %p remains:\\n", a->struct_name, a->ptr);
+               backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
+               fprintf(stderr, "\\n\\n");
+       }
+       DO_ASSERT(allocation_ll == NULL);
+}
+"""
+
+c_file = ""
+def write_c(s):
+    global c_file
+    c_file += s
+

 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):
+    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.is_ptr = is_ptr
         self.var_name = var_name
         self.arr_len = arr_len
         self.java_fn_ty_arg = java_fn_ty_arg
         self.c_ty = c_ty
         self.passed_as_ptr = passed_as_ptr
         self.is_ptr = is_ptr
         self.var_name = var_name
         self.arr_len = arr_len

+        self.arr_access = arr_access
+        self.subty = subty
+        self.pass_by_ref = is_ptr
+        self.requires_clone = None

 
 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)

+        self.passed_as_ptr = ty_info.passed_as_ptr
+        self.rust_obj = ty_info.rust_obj

         self.c_ty = ty_info.c_ty
         self.java_ty = ty_info.java_ty
         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):
 
     def print_ty(self):

-        out_c.write(self.c_ty)
+        write_c(self.c_ty)

         out_java.write(self.java_ty)
 
     def print_name(self):
         if self.arg_name != "":
             out_java.write(" " + self.arg_name)
         out_java.write(self.java_ty)
 
     def print_name(self):
         if self.arg_name != "":
             out_java.write(" " + self.arg_name)

-            out_c.write(" " + self.arg_name)
+            write_c(" " + self.arg_name)

         else:
             out_java.write(" arg")
         else:
             out_java.write(" arg")

-            out_c.write(" arg")
-
-with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[3], "w") as out_c:
-    opaque_structs = set()
-    trait_structs = set()
-    unitary_enums = set()
-
-    var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
-    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
+            write_c(" 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 = {}
+
+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("LDKTransaction"):
+        fn_arg = "uint8_t (*" + fn_arg[15:] + ")[datalen]"
+        rust_obj = "LDKTransaction"
+        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
         is_ptr = False

-        take_by_ptr = False
-        rust_obj = None
-        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"
+        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()
             fn_arg = fn_arg[8:].strip()

-        elif fn_arg.startswith("uint64_t"):
+        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_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"
             c_ty = "jlong"
             fn_ty_arg = "J"

-            fn_arg = fn_arg[8:].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/impl/bindings$" + 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
+            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"
             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_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()
+constructor_fns = {}
+c_array_class_caches = set()
+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))
+            # No object constructors return arrays, as then they wouldn't be an object constructor
+            continue
+java_c_types_none_allowed = False # C structs created by cbindgen are declared in dependency order

 
 

-        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:
-                return TypeInfo(rust_obj=None, 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))
-        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)
-
-    def map_type(fn_arg, print_void, ret_arr_len, is_free):
+with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java:
+    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:


@@ -147,395 +517,1106 @@ 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")
-            return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                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;",
-                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 + ", *",
-                    ");"),
-                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:
-                assert(ty_info.passed_as_ptr)
-                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",
-                            ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
-                            ret_conv_name = ty_info.var_name + "_conv")
-                    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 = base_conv + "\n" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_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",
-                            ret_conv = None, ret_conv_name = None)
-                    base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";
-                    if ty_info.rust_obj in opaque_structs:
-                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                            arg_conv = base_conv + "\n" + ty_info.var_name + "_conv._underlying_ref = false;",
-                            arg_conv_name = ty_info.var_name + "_conv",
-                            ret_conv = None, ret_conv_name = None)
+            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." + arr_len + " = (*_env)->GetArrayLength (_env, " + arr_name + ");\n"
+                    if (not ty_info.is_ptr or not holds_ref) and ty_info.rust_obj != "LDKu8slice":
+                        arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = MALLOC(" + arr_name + "_ref." + arr_len + ", \"" + ty_info.rust_obj + " Bytes\");\n"
+                        arg_conv = arg_conv + "(*_env)->GetByteArrayRegion(_env, " + arr_name + ", 0, " + arr_name + "_ref." + arr_len + ", " + arr_name + "_ref." + ty_info.arr_access + ");"
+                    else:
+                        arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = (*_env)->GetByteArrayElements (_env, " + arr_name + ", NULL);"
+                        arg_conv_cleanup = "(*_env)->ReleaseByteArrayElements(_env, " + arr_name + ", (int8_t*)" + arr_name + "_ref." + ty_info.arr_access + ", 0);"
+                    if ty_info.rust_obj == "LDKTransaction":
+                        arg_conv = arg_conv + "\n" + arr_name + "_ref.data_is_owned = " + str(holds_ref).lower() + ";"
+                    ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
+                    ret_conv = (ret_conv[0], ";\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 != "LDKu8slice":
+                        ret_conv = (ret_conv[0], ret_conv[1] + "\n" + ty_info.rust_obj.replace("LDK", "") + "_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:
+                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
+                ty_info.subty.requires_clone = not ty_info.is_ptr or not holds_ref
+                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 + ");"

 
 

-                    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 = None, ret_conv_name = None)
+                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:
                 else:

-                    assert(not is_free)
-                    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)
-            elif ty_info.is_ptr:
+                    assert ty_info.java_fn_ty_arg.startswith("[")
+                    clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
+                    c_array_class_caches.add(clz_var)
+                    ret_conv = (ret_conv[0], ";\n" + ty_info.c_ty + " " + arr_name + "_arr = (*_env)->NewObjectArray(_env, " + arr_name + "_var." + arr_len + ", " + clz_var + "_clz, 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(*_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,
                 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":
+                    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,
                 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 = 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,
             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)
-        elif not print_void:
+                    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 == "" and 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:
             # 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)
+        elif ty_info.rust_obj is None:
+            return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None,
+                ret_conv = None, ret_conv_name = None, to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)

         else:
         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")
-                    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
-                        # any _free function.
-                        # To avoid any issues, we first assert that the incoming object is non-ref.
-                        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 = ", ";\nassert(!ret->_underlying_ref);\nret->_underlying_ref = true;"),
-                            ret_conv_name = "(long)ret",
-                            arg_conv = None, arg_conv_name = None)
+            if ty_info.var_name == "":
+                ty_info.var_name = "ret"
+
+            if ty_info.rust_obj in opaque_structs:
+                opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
+                if ty_info.is_ptr and holds_ref:
+                    opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = false;"
+                else:
+                    opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"
+                if not is_free and (not ty_info.is_ptr or not holds_ref or ty_info.requires_clone == True) and ty_info.requires_clone != False:
+                    if (ty_info.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!"
+
+                opaque_ret_conv_suf = ";\n"
+                if not holds_ref and ty_info.is_ptr and (ty_info.java_hu_ty + "_clone") in clone_fns: # is_ptr, not holds_ref implies passing a pointed-to value to java, which needs copied
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "if (" + ty_info.var_name + "->inner != NULL)\n"
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "\t" + ty_info.var_name + "_var = " + ty_info.java_hu_ty + "_clone(" + ty_info.var_name + ");\n"
+                elif not holds_ref and ty_info.is_ptr:
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "// Warning: we may need a move here but can't clone!\n"
+
+                opaque_ret_conv_suf = opaque_ret_conv_suf + "CHECK((((long)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
+                opaque_ret_conv_suf = opaque_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:
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "long " + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner & ~1;"
+                else:
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "long " + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner;\n"
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "if (" + ty_info.var_name + "_var.is_owned) {\n"
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "\t" + ty_info.var_name + "_ref |= 1;\n"
+                    opaque_ret_conv_suf = opaque_ret_conv_suf + "}"
+
+                if ty_info.is_ptr:
+                    return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                        arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                        ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = *", opaque_ret_conv_suf),
+                        ret_conv_name = ty_info.var_name + "_ref",
+                        to_hu_conv = 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 + ")"))
+                else:
+                    return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                        arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                        ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", opaque_ret_conv_suf),
+                        ret_conv_name = ty_info.var_name + "_ref",
+                        to_hu_conv = 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 + ")"))
+
+            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", to_hu_conv = None, to_hu_conv_name = None, from_hu_conv = None)
+                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:
+                        needs_full_clone = not is_free and (not ty_info.is_ptr and not holds_ref or ty_info.requires_clone == True) and ty_info.requires_clone != False
+                        if needs_full_clone and (ty_info.java_hu_ty + "_clone") in clone_fns:
+                            base_conv = base_conv + "\n" + ty_info.var_name + "_conv = " + ty_info.java_hu_ty + "_clone(" + ty_info.var_name + ");"
+                        else:
+                            base_conv = base_conv + "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
+                            base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
+                            base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_arg);\n}"
+                            if needs_full_clone:
+                                base_conv = base_conv + "// Warning: we may need a move here but can't do a full clone!\n"
+

                     else:
                     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_cleanup = None,
+                        ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
+                        ret_conv_name = "(long)ret",
+                        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 = (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":
+                    # 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 holds_ref:
+                        ret_conv = (ty_info.rust_obj + " *" + ty_info.var_name + "_copy = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n", "")
+                        if ty_info.requires_clone == True: # Set in object array mapping
+                            if (ty_info.java_hu_ty + "_clone") in clone_fns:
+                                ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = " + ty_info.java_hu_ty + "_clone(&", ");\n")
+                            else:
+                                ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = ", "; // XXX: We likely need to clone here, but no _clone fn is available!\n")
+                        else:
+                            ret_conv = (ret_conv[0] + "*" + ty_info.var_name + "_copy = ", ";\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 + ");\n" + ty_info.var_name + "_hu_conv.ptrs_to.add(this);",
+                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + ".ptr", ""))
+                if ty_info.rust_obj in result_types:
+                    assert not ty_info.is_ptr and not holds_ref # Otherwise we shouldn't be MALLOC'ing
+                    ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_conv = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_conv = ", ";")
+                    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 = "(long)" + ty_info.var_name + "_conv",
+                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");\n" + ty_info.var_name + "_hu_conv.ptrs_to.add(this);",
+                        to_hu_conv_name = ty_info.var_name + "_hu_conv", from_hu_conv = (ty_info.var_name + " != null ? " + ty_info.var_name + ".ptr : 0", ""))
+                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: " + conv_map.from_hu_conv[1] + "*/"
+                        else:
+                            from_hu_conv = from_hu_conv + ty_info.var_name + "." + chr(idx + ord("a"))
+
+                    if not ty_info.is_ptr and not holds_ref:

                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         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)
-                else:
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+
+                            ret_conv = (ty_info.rust_obj + "* " + ty_info.var_name + "_ref = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*" + ty_info.var_name + "_ref = ", ";"),
+                            ret_conv_name = "(long)" + 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 + ")", ""))

                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     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)
-            else:
+                        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 == "LDKTxOut"

                 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 = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
+                    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", ""))
+            elif ty_info.is_ptr:
+                assert(not is_free)
+                if 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 = ("long ret_" + ty_info.var_name + " = (long)", ";"), ret_conv_name = "ret_" + ty_info.var_name,
+                        to_hu_conv = ty_info.java_hu_ty + " " + ty_info.var_name + "_hu_conv = " + ty_info.java_hu_ty + ".constr_from_ptr(" + ty_info.var_name + ");",
+                        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 + ")"))
+                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 = ("long ret_" + ty_info.var_name + " = (long)", ";"), ret_conv_name = "ret_" + ty_info.var_name,
+                        to_hu_conv = ty_info.java_hu_ty + " ret_hu_conv = new " + ty_info.java_hu_ty + "(null, ret);\nret_hu_conv.ptrs_to.add(this);",
+                        to_hu_conv_name = "ret_hu_conv",
+                        from_hu_conv = (ty_info.var_name + " == null ? 0 : " + ty_info.var_name + ".ptr", "this.ptrs_to.add(" + ty_info.var_name + ")"))
+                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 = ("long ret_" + ty_info.var_name + " = (long)", ";"), ret_conv_name = "ret_" + ty_info.var_name,
+                    to_hu_conv = "TODO 3", to_hu_conv_name = None, from_hu_conv = None) # its a pointer, no conv needed
+            assert False # We should have handled every case by now.

 
 

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

         out_java.write("\tpublic static native ")
         out_java.write("\tpublic static native ")

-        out_c.write("JNIEXPORT ")
+        write_c("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 = map_type(re_match.group(1), True, ret_arr_len, False, False)

         ret_info.print_ty()
         ret_info.print_ty()

+

         if ret_info.ret_conv is not None:
             ret_conv_pfx, ret_conv_sfx = ret_info.ret_conv
 
         out_java.write(" " + re_match.group(2) + "(")
         if ret_info.ret_conv is not None:
             ret_conv_pfx, ret_conv_sfx = ret_info.ret_conv
 
         out_java.write(" " + re_match.group(2) + "(")

-        out_c.write(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")
+        write_c(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")

 
         arg_names = []
 
         arg_names = []

+        default_constructor_args = {}
+        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 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":
         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"))
+                write_c(", ")
+            arg_conv_info = map_type(arg, False, None, is_free, True)

             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_ptr" or arg_conv_info.arg_name == "this_arg":
+                takes_self = True
+            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, True)
+                        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)
 
             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:
+                meth_n = re_match.group(2)[len(struct_meth) + 1:]
+                if ret_info.rust_obj == "LDK" + struct_meth:
+                    out_java_struct.write("\tpublic static " + ret_info.java_hu_ty + " constructor_" + meth_n + "(")
+                else:
+                    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(", ")
+                    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:
+                            out_java_struct.write(arg.java_hu_ty + " " + arg.arg_name)
+
+

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

-        out_c.write(") {\n")
+        write_c(") {\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:
 
         for info in arg_names:
             if info.arg_conv is not None:

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

         else:
         else:

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

 
 

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

         for idx, info in enumerate(arg_names):
             if info.arg_conv_name is not None:
                 if idx != 0:
         for idx, info in enumerate(arg_names):
             if info.arg_conv_name is not None:
                 if idx != 0:

-                    out_c.write(", ")
-                out_c.write(info.arg_conv_name)
-        out_c.write(")")
+                    write_c(", ")
+                elif c_call_string is not None:
+                    continue
+                write_c(info.arg_conv_name)
+        write_c(")")

         if ret_info.ret_conv is not None:
         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 + ";")
+            write_c(ret_conv_sfx.replace('\n', '\n\t'))

         else:
         else:

-            out_c.write(";")
-        out_c.write("\n}\n\n")
+            write_c(";")
+        for info in arg_names:
+            if info.arg_conv_cleanup is not None:
+                write_c("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
+        if ret_info.ret_conv is not None:
+            write_c("\n\treturn " + ret_info.ret_conv_name + ";")
+        elif ret_info.c_ty != "void":
+            write_c("\n\treturn ret_val;")
+        write_c("\n}\n\n")
+        if out_java_struct is not None:
+            out_java_struct.write("\t\t")
+            if ret_info.java_ty != "void":
+                out_java_struct.write(ret_info.java_ty + " ret = ")
+            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_ptr" or info.arg_name == "this_arg":
+                    out_java_struct.write("this.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)
+            out_java_struct.write(");\n")
+            if ret_info.to_hu_conv is not None:
+                if ret_info.rust_obj == "LDK" + struct_meth:
+                    out_java_struct.write("\t\t" + ret_info.to_hu_conv.replace("\n", "\n\t\t").replace("this", ret_info.to_hu_conv_name) + "\n")
+                else:
+                    out_java_struct.write("\t\t" + ret_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
+
+            for info in arg_names:
+                if info.arg_name == "this_ptr" or info.arg_name == "this_arg":
+                    pass
+                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.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()
+
+    def map_unitary_enum(struct_name, field_lines):
+        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)
+            write_c("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
+            write_c("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
+            ord_v = 0
+            for idx, struct_line in enumerate(field_lines):
+                if idx == 0:
+                    out_java_enum.write("public enum " + struct_name + " {\n")
+                elif idx == len(field_lines) - 3:
+                    assert(struct_line.endswith("_Sentinel,"))
+                elif idx == len(field_lines) - 2:
+                    out_java_enum.write("\t; static native void init();\n")
+                    out_java_enum.write("\tstatic { init(); }\n")
+                    out_java_enum.write("}")
+                    out_java.write("\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n")
+                elif idx == len(field_lines) - 1:
+                    assert(struct_line == "")
+                else:
+                    out_java_enum.write(struct_line + "\n")
+                    write_c("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
+                    ord_v = ord_v + 1
+            write_c("\t}\n")
+            write_c("\tabort();\n")
+            write_c("}\n")
+
+            ord_v = 0
+            write_c("static jclass " + 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(",")
+                    write_c("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
+            write_c("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
+            write_c("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")
+            write_c("\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(",")
+                    write_c("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")
+                    write_c("\tCHECK(" + struct_name + "_" + variant + " != NULL);\n")
+            write_c("}\n")
+            write_c("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
+            write_c("\tswitch (val) {\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    write_c("\t\tcase " + variant + ":\n")
+                    write_c("\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + variant + ");\n")
+                    ord_v = ord_v + 1
+            write_c("\t\tdefault: abort();\n")
+            write_c("\t}\n")
+            write_c("}\n\n")
+
+    def map_complex_enum(struct_name, union_enum_items):
+        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")
+                    write_c("static jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
+                    write_c("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");
+
+            write_c("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:]
+                    write_c("\t" + struct_name + "_" + var_name + "_class =\n")
+                    write_c("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
+                    write_c("\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n")
+                    write_c("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
+                    write_c("\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n")
+            write_c("}\n")
+            write_c("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * _env, jclass _c, jlong ptr) {\n")
+            write_c("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
+            write_c("\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:]
+                    write_c("\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:
+                                    write_c("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
+                                    write_c("obj->" + camel_to_snake(var_name) + "." + field_map.arg_name)
+                                    write_c(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
+                    write_c("\t\t\treturn (*_env)->NewObject(_env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth" + c_params_text + ");\n")
+                    write_c("\t\t}\n")
+            write_c("\t\tdefault: abort();\n")
+            write_c("\t}\n}\n")
+            out_java_enum.write("}\n")

 
     def map_trait(struct_name, field_var_lines, trait_fn_lines):
 
     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("\tJNIEnv *env;\n")
-        out_c.write("\tjobject 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")
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_trait:
+            write_c("typedef struct " + struct_name + "_JCalls {\n")
+            write_c("\tatomic_size_t refcnt;\n")
+            write_c("\tJavaVM *vm;\n")
+            write_c("\tjweak o;\n")
+            field_var_convs = []
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    write_c("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
+                    field_var_convs.append(None)
+                else:
+                    field_var_convs.append(map_type(var_line.group(1) + " " + var_line.group(2), False, None, False, False))
+            for fn_line in trait_fn_lines:
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    write_c("\tjmethodID " + fn_line.group(2) + "_meth;\n")
+            write_c("} " + 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")
+            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("\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 idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    out_java_trait.write(", bindings." + var_line.group(1) + " " + var_line.group(2))
+                else:
+                    out_java_trait.write(", " + field_var_convs[idx].java_hu_ty + " " + var_line.group(2))
+            out_java_trait.write(") {\n")
+            out_java_trait.write("\t\tsuper(bindings." + struct_name + "_new(arg")
+            for idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    out_java_trait.write(", " + var_line.group(2))
+                elif field_var_convs[idx].from_hu_conv is not None:
+                    out_java_trait.write(", " + field_var_convs[idx].from_hu_conv[0])

                 else:
                 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")
-
-                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", "j_calls->env"));
-                        out_c.write(arg_info.arg_name)
-                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "j_calls->env") + "\n")
-
-                if not ret_ty_info.passed_as_ptr:
-                    out_c.write("\treturn (*j_calls->env)->Call" + ret_ty_info.java_ty.title() + "Method(j_calls->env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth")
+                    out_java_trait.write(", " + var_line.group(2))
+            out_java_trait.write("));\n")
+            out_java_trait.write("\t\tthis.ptrs_to.add(arg);\n")
+            for idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    out_java_trait.write("\t\tthis.ptrs_to.add(" + var_line.group(2) + ");\n")
+                elif field_var_convs[idx].from_hu_conv is not None and field_var_convs[idx].from_hu_conv[1] != "":
+                    out_java_trait.write("\t\t" + field_var_convs[idx].from_hu_conv[1] + ";\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\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n")
+            out_java_trait.write("\t}\n\n")
+
+            java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
+            java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
+            for idx, var_line in enumerate(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) + "_impl"

                 else:
                 else:

-                    out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*j_calls->env)->CallLongMethod(j_calls->env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth");
+                    java_trait_constr = java_trait_constr + ", " + field_var_convs[idx].java_hu_ty + " " + var_line.group(2)
+            java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
+            java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(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":
+                    ret_ty_info = map_type(fn_line.group(1), True, None, False, False)

 
 

-                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("\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
+                    write_c(fn_line.group(1) + fn_line.group(2) + "_jcall(")
+                    if is_const:
+                        write_c("const void* this_arg")

                     else:
                     else:

-                        out_c.write(", " + arg_info.arg_name)
-                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\t(*j_calls->env)->DeleteGlobalRef(j_calls->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_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("\tassert(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("\tcalls->env = env;\n")
-        out_c.write("\tcalls->o = (*env)->NewGlobalRef(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("\tassert(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")
-
-        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")
+                        write_c("void* this_arg")
+
+                    arg_names = []
+                    for idx, arg in enumerate(fn_line.group(4).split(',')):
+                        if arg == "":
+                            continue
+                        if idx >= 2:
+                            out_java.write(", ")
+                            java_trait_constr = java_trait_constr + ", "
+                            out_java_trait.write(", ")
+                        write_c(", ")
+                        arg_conv_info = map_type(arg, True, None, False, False)
+                        write_c(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")
+                    out_java_trait.write(");\n")
+                    java_trait_constr = java_trait_constr + ") {\n"
+                    write_c(") {\n")
+                    write_c("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+                    write_c("\tJNIEnv *_env;\n")
+                    write_c("\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:
+                            write_c("\t" + arg_info.ret_conv[0].replace('\n', '\n\t'));
+                            write_c(arg_info.arg_name)
+                            write_c(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"

 
 

+                    write_c("\tjobject obj = (*_env)->NewLocalRef(_env, j_calls->o);\n\tCHECK(obj != NULL);\n")
+                    if ret_ty_info.c_ty.endswith("Array"):
+                        write_c("\t" + ret_ty_info.c_ty + " arg = (*_env)->CallObjectMethod(_env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    elif not ret_ty_info.passed_as_ptr:
+                        write_c("\treturn (*_env)->Call" + ret_ty_info.java_ty.title() + "Method(_env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    else:
+                        write_c("\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:
+                        java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.group(2) + "("
+
+                    for idx, arg_info in enumerate(arg_names):
+                        if arg_info.ret_conv is not None:
+                            write_c(", " + arg_info.ret_conv_name)
+                        else:
+                            write_c(", " + 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
+                    write_c(");\n");
+                    if ret_ty_info.arg_conv is not None:
+                        write_c("\t" + ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n\treturn " + ret_ty_info.arg_conv_name + ";\n")
+
+                    write_c("}\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].replace("this", "impl_holder.held") + ";\n"
+                            if ret_ty_info.rust_obj in result_types:
+                                # Avoid double-free by breaking the result - we should learn to clone these and then we can be safe instead
+                                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":
+                    write_c("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
+                    write_c("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+                    write_c("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
+                    write_c("\t\tJNIEnv *env;\n")
+                    write_c("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
+                    write_c("\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n")
+                    write_c("\t\tFREE(j_calls);\n")
+                    write_c("\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 + ", " + var_line.group(2) + ".new_impl(" + var_line.group(2) + "_impl).bindings_instance"
+                else:
+                    java_trait_constr = java_trait_constr + ", " + var_line.group(2)
+            out_java_trait.write("\t}\n")
+            out_java_trait.write(java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n")
+
+            # Write out a clone function whether we need one or not, as we use them in moving to rust
+            write_c("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
+            write_c("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+            write_c("\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:
+                    write_c("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
+            write_c("\treturn (void*) this_arg;\n")
+            write_c("}\n")
+
+            out_java.write("\t}\n")
+
+            out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
+            write_c("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
+            for idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
+                    write_c(", jobject " + var_line.group(2))
+                else:
+                    out_java.write(", " + field_var_convs[idx].java_ty + " " + var_line.group(2))
+                    write_c(", " + field_var_convs[idx].c_ty + " " + var_line.group(2))
+            out_java.write(");\n")
+            write_c(") {\n")
+
+            write_c("\tjclass c = (*env)->GetObjectClass(env, o);\n")
+            write_c("\tCHECK(c != NULL);\n")
+            write_c("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
+            write_c("\tatomic_init(&calls->refcnt, 1);\n")
+            write_c("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")
+            write_c("\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":
+                    write_c("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")
+                    write_c("\tCHECK(calls->" + fn_line.group(2) + "_meth != NULL);\n")
+            for idx, var_line in enumerate(field_var_lines):
+                if field_var_convs[idx] is not None and field_var_convs[idx].arg_conv is not None:
+                    write_c("\n\t" + field_var_convs[idx].arg_conv.replace("\n", "\n\t") +"\n")
+            write_c("\n\t" + struct_name + " ret = {\n")
+            write_c("\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":
+                    write_c("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
+                elif fn_line.group(2) == "free":
+                    write_c("\t\t.free = " + struct_name + "_JCalls_free,\n")
+                else:
+                    write_c("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
+            for idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    write_c("\t\t." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
+                elif field_var_convs[idx].arg_conv_name is not None:
+                    write_c("\t\t." + var_line.group(2) + " = " + field_var_convs[idx].arg_conv_name + ",\n")
+                    write_c("\t\t.set_" + var_line.group(2) + " = NULL,\n")
+                else:
+                    write_c("\t\t." + var_line.group(2) + " = " + var_line.group(2) + ",\n")
+                    write_c("\t\t.set_" + var_line.group(2) + " = NULL,\n")
+            write_c("\t};\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    write_c("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
+            write_c("\treturn ret;\n")
+            write_c("}\n")
+
+            write_c("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
+            for idx, var_line in enumerate(field_var_lines):
+                if var_line.group(1) in trait_structs:
+                    write_c(", jobject " + var_line.group(2))
+                else:
+                    write_c(", " + field_var_convs[idx].c_ty + " " + var_line.group(2))
+            write_c(") {\n")
+            write_c("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+            write_c("\t*res_ptr = " + struct_name + "_init(env, _a, o")
+            for var_line in field_var_lines:
+                write_c(", " + var_line.group(2))
+            write_c(");\n")
+            write_c("\treturn (long)res_ptr;\n")
+            write_c("}\n")
+
+            out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
+            write_c("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
+            write_c("\tjobject ret = (*env)->NewLocalRef(env, ((" + struct_name + "_JCalls*)val)->o);\n")
+            write_c("\tCHECK(ret != NULL);\n")
+            write_c("\treturn ret;\n")
+            write_c("}\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.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")
+        for idx, var_line in enumerate(field_var_lines):
+            if var_line.group(1) not in trait_structs:
+                write_c(var_line.group(1) + " " + struct_name + "_set_get_" + var_line.group(2) + "(" + struct_name + "* this_arg) {\n")
+                write_c("\tif (this_arg->set_" + var_line.group(2) + " != NULL)\n")
+                write_c("\t\tthis_arg->set_" + var_line.group(2) + "(this_arg);\n")
+                write_c("\treturn this_arg->" + var_line.group(2) + ";\n")
+                write_c("}\n")
+                dummy_line = var_line.group(1) + " " + struct_name.replace("LDK", "") + "_get_" + var_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, struct_name + "_set_get_" + var_line.group(2) + "(this_arg_conv")

 
     out_java.write("""package org.ldk.impl;
 
     out_java.write("""package org.ldk.impl;

+import org.ldk.enums.*;

 
 public class bindings {
 
 public class bindings {

-       static native void init(java.lang.Class c);
+       public static class VecOrSliceDef {
+               public long dataptr;
+               public long datalen;
+               public long stride;
+               public VecOrSliceDef(long dataptr, long datalen, long stride) {
+                       this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
+               }
+       }

        static {
                System.loadLibrary(\"lightningjni\");
        static {
                System.loadLibrary(\"lightningjni\");

-               init(java.lang.Enum.class);
+               init(java.lang.Enum.class, VecOrSliceDef.class);
+               init_class_cache();

        }
        }

+       static native void init(java.lang.Class c, java.lang.Class slicedef);
+       static native void init_class_cache();
+
+       public static native boolean deref_bool(long ptr);
+       public static native long deref_long(long ptr);
+       public static native void free_heap_ptr(long ptr);
+       public static native byte[] read_bytes(long ptr, long len);
+       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 byte[] txpointer_get_buffer(long ptr);
+       public static native long vec_slice_len(long vec);
+       public static native long new_empty_slice_vec();

 
 """)
 
 """)

-    out_c.write("#include \"org_ldk_impl_bindings.h\"\n")
-    out_c.write("#include <rust_types.h>\n")
-    out_c.write("#include <lightning.h>\n")
-    out_c.write("#include <assert.h>\n")
-    out_c.write("#include <string.h>\n")
-    out_c.write("#include <stdatomic.h>\n\n")
-
-    out_c.write("jmethodID ordinal_meth = NULL;\n")
-    out_c.write("JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {\n")
-    out_c.write("\tordinal_meth = (*env)->GetMethodID(env, enum_class, \"ordinal\", \"()I\");\n")
-    out_c.write("\tassert(ordinal_meth != NULL);\n")
-    out_c.write("}\n\n")
-
-    if sys.argv[4] == "false":
-        out_c.write("#define MALLOC(a, _) malloc(a)\n")
-        out_c.write("#define FREE free\n\n")
-    else:
-        out_c.write("#include <threads.h>\n")
-        out_c.write("static mtx_t allocation_mtx;\n\n")
-        out_c.write("void __attribute__((constructor)) init_mtx() {\n")
-        out_c.write("\tassert(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);\n")
-        out_c.write("}\n\n")
-        out_c.write("typedef struct allocation {\n")
-        out_c.write("\tstruct allocation* next;\n")
-        out_c.write("\tvoid* ptr;\n")
-        out_c.write("\tconst char* struct_name;\n")
-        out_c.write("} allocation;\n")
-        out_c.write("static allocation* allocation_ll = NULL;\n\n")
-        out_c.write("void* MALLOC(size_t len, const char* struct_name) {\n")
-        out_c.write("\tvoid* res = malloc(len);\n")
-        out_c.write("\tallocation* new_alloc = malloc(sizeof(allocation));\n")
-        out_c.write("\tnew_alloc->ptr = res;\n")
-        out_c.write("\tnew_alloc->struct_name = struct_name;\n")
-        out_c.write("\tassert(mtx_lock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tnew_alloc->next = allocation_ll;\n")
-        out_c.write("\tallocation_ll = new_alloc;\n")
-        out_c.write("\tassert(mtx_unlock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\treturn res;\n")
-        out_c.write("}\n\n")
-        out_c.write("void FREE(void* ptr) {\n")
-        out_c.write("\tallocation* p = NULL;\n")
-        out_c.write("\tassert(mtx_lock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tallocation* it = allocation_ll;\n")
-        out_c.write("\twhile (it->ptr != ptr) { p = it; it = it->next; }\n")
-        out_c.write("\tif (p) { p->next = it->next; } else { allocation_ll = it->next; }\n")
-        out_c.write("\tassert(mtx_unlock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tassert(it->ptr == ptr);\n")
-        out_c.write("\tfree(it);\n")
-        out_c.write("\tfree(ptr);\n")
-        out_c.write("}\n\n")
-        out_c.write("void __attribute__((destructor)) check_leaks() {\n")
-        out_c.write("\tfor (allocation* a = allocation_ll; a != NULL; a = a->next) { fprintf(stderr, \"%s %p remains\\n\", a->struct_name, a->ptr); }\n")
-        out_c.write("\tassert(allocation_ll == NULL);\n")
-        out_c.write("}\n\n")
-
-    # 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
+    write_c("""
+static jmethodID ordinal_meth = NULL;
+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");
+       CHECK(ordinal_meth != NULL);
+       slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
+       CHECK(slicedef_meth != NULL);
+       slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
+       CHECK(slicedef_cls != NULL);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
+       return *((bool*)ptr);
+}
+JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
+       return *((long*)ptr);
+}
+JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
+       FREE((void*)ptr);
+}
+JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * _env, jclass _b, jlong ptr, jlong len) {
+       jbyteArray ret_arr = (*_env)->NewByteArray(_env, len);
+       (*_env)->SetByteArrayRegion(_env, ret_arr, 0, len, (unsigned char*)ptr);
+       return ret_arr;
+}
+JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * _env, jclass _b, jlong slice_ptr) {
+       LDKu8slice *slice = (LDKu8slice*)slice_ptr;
+       jbyteArray ret_arr = (*_env)->NewByteArray(_env, slice->datalen);
+       (*_env)->SetByteArrayRegion(_env, ret_arr, 0, slice->datalen, slice->data);
+       return ret_arr;
+}
+JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_bytes_1to_1u8_1vec (JNIEnv * _env, jclass _b, jbyteArray bytes) {
+       LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
+       vec->datalen = (*_env)->GetArrayLength(_env, bytes);
+       vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
+       (*_env)->GetByteArrayRegion (_env, bytes, 0, vec->datalen, vec->data);
+       return (long)vec;
+}
+JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_txpointer_1get_1buffer (JNIEnv * env, jclass _b, jlong ptr) {
+       LDKTransaction *txdata = (LDKTransaction*)ptr;
+       LDKu8slice slice;
+       slice.data = txdata->data;
+       slice.datalen = txdata->datalen;
+       return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (long)&slice);
+}
+JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray 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 = false;
+       (*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) {
+       // 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_C2Tuple_usizeTransactionZZ, datalen), "Vec<*> needs to be mapped identically");
+       LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
+       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
+       _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_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
+       LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
+       vec->data = NULL;
+       vec->datalen = 0;
+       return (long)vec;
+}
+
+// We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
+_Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
+_Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
+_Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
+
+""")
+
+    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 {
+       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
 
 
     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]*);$")
 
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 

-    line_indicates_opaque_regex = re.compile("^   bool _underlying_ref;$")
+    line_indicates_result_regex = re.compile("^   (LDKCResultPtr_[A-Za-z_0-9]*) contents;$")
+    line_indicates_vec_regex = re.compile("^   ([A-Za-z_0-9]*) \*data;$")
+    line_indicates_opaque_regex = re.compile("^   bool is_owned;$")

     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
     assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))
     assert(line_indicates_trait_regex.match("   LDKCVec_MessageSendEventZ (*get_and_clear_pending_msg_events)(const void *this_arg);"))
     assert(line_indicates_trait_regex.match("   void *(*clone)(const void *this_arg);"))
     line_field_var_regex = re.compile("^   ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
     assert(line_field_var_regex.match("   LDKMessageSendEventsProvider MessageSendEventsProvider;"))
     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
     assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))
     assert(line_indicates_trait_regex.match("   LDKCVec_MessageSendEventZ (*get_and_clear_pending_msg_events)(const void *this_arg);"))
     assert(line_indicates_trait_regex.match("   void *(*clone)(const void *this_arg);"))
     line_field_var_regex = re.compile("^   ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
     assert(line_field_var_regex.match("   LDKMessageSendEventsProvider MessageSendEventsProvider;"))

+    assert(line_field_var_regex.match("   LDKChannelPublicKeys pubkeys;"))

     struct_name_regex = re.compile("^typedef (struct|enum|union) (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
     assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
     assert(struct_name_regex.match("typedef enum LDKNetwork {"))
     struct_name_regex = re.compile("^typedef (struct|enum|union) (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
     assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
     assert(struct_name_regex.match("typedef enum LDKNetwork {"))

+    struct_alias_regex = re.compile("^typedef (LDK[A-Za-z_0-9]*) (LDK[A-Za-z_0-9]*);$")
+    assert(struct_alias_regex.match("typedef LDKCResultTempl_bool__PeerHandleError LDKCResult_boolPeerHandleErrorZ;"))

 
 

+    result_templ_structs = set()
+    union_enum_items = {}
+    result_ptr_struct_items = {}

     for line in in_h:
         if in_block_comment:
     for line in in_h:
         if in_block_comment:

-            #out_java.write("\t" + line)

             if line.endswith("*/\n"):
                 in_block_comment = False
         elif cur_block_obj is not None:
             if line.endswith("*/\n"):
                 in_block_comment = False
         elif cur_block_obj is not None:


@@ -543,11 +1624,14 @@ public class bindings {
             if line.startswith("} "):
                 field_lines = []
                 struct_name = None
             if line.startswith("} "):
                 field_lines = []
                 struct_name = None

+                vec_ty = None

                 obj_lines = cur_block_obj.split("\n")
                 is_opaque = False
                 obj_lines = cur_block_obj.split("\n")
                 is_opaque = False

+                result_contents = None

                 is_unitary_enum = False
                 is_union_enum = False
                 is_union = False
                 is_unitary_enum = False
                 is_union_enum = False
                 is_union = False

+                is_tuple = False

                 trait_fn_lines = []
                 field_var_lines = []
 
                 trait_fn_lines = []
                 field_var_lines = []
 


@@ -570,6 +1654,14 @@ public class bindings {
                                 is_union = True
                         if line_indicates_opaque_regex.match(struct_line):
                             is_opaque = True
                                 is_union = True
                         if line_indicates_opaque_regex.match(struct_line):
                             is_opaque = True

+                        result_match = line_indicates_result_regex.match(struct_line)
+                        if result_match is not None:
+                            result_contents = result_match.group(1)
+                        vec_ty_match = line_indicates_vec_regex.match(struct_line)
+                        if vec_ty_match is not None and struct_name.startswith("LDKCVecTempl_"):
+                            vec_ty = vec_ty_match.group(1)
+                        elif struct_name.startswith("LDKC2TupleTempl_") or struct_name.startswith("LDKC3TupleTempl_"):
+                            is_tuple = True

                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)
                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)


@@ -579,56 +1671,140 @@ public class bindings {
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)

-                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union))
-                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union))
-                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union))
-                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union))
-                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque))
+                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or result_contents is not None or vec_ty is not None))
+                assert(result_contents is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or vec_ty is not None))
+                assert(vec_ty is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or result_contents is not None))
+

                 if is_opaque:
                     opaque_structs.add(struct_name)
                 if is_opaque:
                     opaque_structs.add(struct_name)

-                elif is_unitary_enum:
-                    unitary_enums.add(struct_name)
-                    out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
-                    out_c.write("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
-                    ord_v = 0
-                    for idx, struct_line in enumerate(field_lines):
-                        if idx == 0:
-                            out_java.write("\tpublic enum " + struct_name + " {\n")
-                        elif idx == len(field_lines) - 3:
-                            assert(struct_line.endswith("_Sentinel,"))
-                        elif idx == len(field_lines) - 2:
-                            out_java.write("\t}\n")
-                        elif idx == len(field_lines) - 1:
-                            assert(struct_line == "")
+                    with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_struct:
+                        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")
+                        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)
+                    assert result_contents in result_ptr_struct_items
+                elif struct_name.startswith("LDKCResultPtr_"):
+                    for line in field_lines:
+                        if line.endswith("*result;"):
+                            res_ty = line[:-8].strip()
+                        elif line.endswith("*err;"):
+                            err_ty = line[:-5].strip()
+                    result_ptr_struct_items[struct_name] = (res_ty, err_ty)
+                elif is_tuple:
+                    out_java.write("\tpublic static native long " + struct_name + "_new(")
+                    write_c("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)
+                            if idx != 1:
+                                out_java.write(", ")
+                            e = chr(ord('a') + idx - 1)
+                            out_java.write(ty_info.java_ty + " " + e)
+                            write_c(", " + ty_info.c_ty + " " + e)
+                            ty_list.append(ty_info)
+                    tuple_types[struct_name] = (ty_list, struct_name)
+                    out_java.write(");\n")
+                    write_c(") {\n")
+                    write_c("\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, False)
+                            e = chr(ord('a') + idx - 1)
+                            if ty_info.arg_conv is not None:
+                                write_c("\t" + ty_info.arg_conv.replace("\n", "\n\t"))
+                                write_c("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
+                            else:
+                                write_c("\tret->" + e + " = " + e + ";\n")
+                            if ty_info.arg_conv_cleanup is not None:
+                                write_c("\t//TODO: Really need to call " + ty_info.arg_conv_cleanup + " here\n")
+                    write_c("\treturn (long)ret;\n")
+                    write_c("}\n")
+                elif vec_ty is not None:
+                    if vec_ty in opaque_structs:
+                        out_java.write("\tpublic static native long[] " + struct_name + "_arr_info(long vec_ptr);\n")
+                        write_c("JNIEXPORT jlongArray JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    else:
+                        out_java.write("\tpublic static native VecOrSliceDef " + struct_name + "_arr_info(long vec_ptr);\n")
+                        write_c("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    write_c("\t" + struct_name + " *vec = (" + struct_name + "*)ptr;\n")
+                    if vec_ty in opaque_structs:
+                        write_c("\tjlongArray ret = (*env)->NewLongArray(env, vec->datalen);\n")
+                        write_c("\tjlong *ret_elems = (*env)->GetPrimitiveArrayCritical(env, ret, NULL);\n")
+                        write_c("\tfor (size_t i = 0; i < vec->datalen; i++) {\n")
+                        write_c("\t\tCHECK((((long)vec->data[i].inner) & 1) == 0);\n")
+                        write_c("\t\tret_elems[i] = (long)vec->data[i].inner | (vec->data[i].is_owned ? 1 : 0);\n")
+                        write_c("\t}\n")
+                        write_c("\t(*env)->ReleasePrimitiveArrayCritical(env, ret, ret_elems, 0);\n")
+                        write_c("\treturn ret;\n")
+                    else:
+                        write_c("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")
+                    write_c("}\n")
+
+                    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")
+                        write_c("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")
+                        write_c("\t" + struct_name + " *ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+                        write_c("\tret->datalen = (*env)->GetArrayLength(env, elems);\n")
+                        write_c("\tif (ret->datalen == 0) {\n")
+                        write_c("\t\tret->data = NULL;\n")
+                        write_c("\t} else {\n")
+                        write_c("\t\tret->data = MALLOC(sizeof(" + vec_ty + ") * ret->datalen, \"" + struct_name + " Data\");\n")
+                        write_c("\t\t" + ty_info.c_ty + " *java_elems = (*env)->GetPrimitiveArrayCritical(env, elems, NULL);\n")
+                        write_c("\t\tfor (size_t i = 0; i < ret->datalen; i++) {\n")
+                        if ty_info.arg_conv is not None:
+                            write_c("\t\t\t" + ty_info.c_ty + " arr_elem = java_elems[i];\n")
+                            write_c("\t\t\t" + ty_info.arg_conv.replace("\n", "\n\t\t\t") + "\n")
+                            write_c("\t\t\tret->data[i] = " + ty_info.arg_conv_name + ";\n")
+                            assert ty_info.arg_conv_cleanup is None

                         else:
                         else:

-                            out_java.write("\t" + struct_line + "\n")
-                            out_c.write("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
-                            ord_v = ord_v + 1
-                    out_c.write("\t}\n")
-                    out_c.write("\tassert(false);\n")
-                    out_c.write("}\n")
-
-                    ord_v = 0
-                    out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
-                    out_c.write("\t// TODO: This is pretty inefficient, we really need to cache the field IDs and class\n")
-                    out_c.write("\tjclass enum_class = (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + ";\");\n")
-                    out_c.write("\tassert(enum_class != NULL);\n")
-                    out_c.write("\tswitch (val) {\n")
-                    for idx, struct_line in enumerate(field_lines):
-                        if idx > 0 and idx < len(field_lines) - 3:
-                            variant = struct_line.strip().strip(",")
-                            out_c.write("\t\tcase " + variant + ": {\n")
-                            out_c.write("\t\t\tjfieldID field = (*env)->GetStaticFieldID(env, enum_class, \"" + variant + "\", \"Lorg/ldk/impl/bindings$" + struct_name + ";\");\n")
-                            out_c.write("\t\t\tassert(field != NULL);\n")
-                            out_c.write("\t\t\treturn (*env)->GetStaticObjectField(env, enum_class, field);\n")
-                            out_c.write("\t\t}\n")
-                            ord_v = ord_v + 1
-                    out_c.write("\t\tdefault: assert(false);\n")
-                    out_c.write("\t}\n")
-                    out_c.write("}\n\n")
+                            write_c("\t\t\tret->data[i] = java_elems[i];\n")
+                        write_c("\t\t}\n")
+                        write_c("\t\t(*env)->ReleasePrimitiveArrayCritical(env, elems, java_elems, 0);\n")
+                        write_c("\t}\n")
+                        write_c("\treturn (long)ret;\n")
+                        write_c("}\n")
+                elif is_union_enum:
+                    assert(struct_name.endswith("_Tag"))
+                    struct_name = struct_name[:-4]
+                    union_enum_items[struct_name] = {"field_lines": field_lines}
+                elif struct_name.endswith("_Body") and struct_name.split("_")[0] in union_enum_items:
+                    enum_var_name = struct_name.split("_")
+                    union_enum_items[enum_var_name[0]][enum_var_name[1]] = field_lines
+                elif struct_name in union_enum_items:
+                    map_complex_enum(struct_name, union_enum_items[struct_name])
+                elif is_unitary_enum:
+                    map_unitary_enum(struct_name, field_lines)

                 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("}")
+                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)


@@ -649,13 +1825,124 @@ public class bindings {
             elif line.startswith("typedef union "):
                 cur_block_obj = line
             elif line.startswith("typedef "):
             elif line.startswith("typedef union "):
                 cur_block_obj = line
             elif line.startswith("typedef "):

-                pass
+                alias_match =  struct_alias_regex.match(line)
+                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")
+                        write_c("JNIEXPORT " + ty_info.c_ty + " JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1" + e + "(JNIEnv *_env, jclass _b, jlong ptr) {\n")
+                        write_c("\t" + alias_match.group(1) + " *tuple = (" + alias_match.group(1) + "*)ptr;\n")
+                        conv_info = map_type_with_info(ty_info, False, None, False, True)
+                        if conv_info.ret_conv is not None:
+                            write_c("\t" + conv_info.ret_conv[0].replace("\n", "\n\t") + "tuple->" + e + conv_info.ret_conv[1].replace("\n", "\n\t") + "\n")
+                            write_c("\treturn " + conv_info.ret_conv_name + ";\n")
+                        else:
+                            write_c("\treturn tuple->" + e + ";\n")
+                        write_c("}\n")
+                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")
+                        write_c("JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1result_1ok (JNIEnv * env, jclass _a, jlong arg) {\n")
+                        write_c("\treturn ((" + alias_match.group(2) + "*)arg)->result_ok;\n")
+                        write_c("}\n")
+
+                        out_java.write("\tpublic static native " + res_map.java_ty + " " + alias_match.group(2) + "_get_ok(long arg);\n")
+                        write_c("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")
+                        write_c("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
+                        write_c("\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:
+                            write_c(res_map.ret_conv[0].replace("\n", "\n\t") + "(*val->contents.result)")
+                            write_c(res_map.ret_conv[1].replace("\n", "\n\t") + "\n\treturn " + res_map.ret_conv_name)
+                        else:
+                            write_c("return *val->contents.result")
+                        write_c(";\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")
+                        write_c("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")
+                        write_c("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
+                        write_c("\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:
+                            write_c(err_map.ret_conv[0].replace("\n", "\n\t") + "(*val->contents.err)")
+                            write_c(err_map.ret_conv[1].replace("\n", "\n\t") + "\n\treturn " + err_map.ret_conv_name)
+                        else:
+                            write_c("return *val->contents.err")
+                        write_c(";\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:
             elif fn_ptr is not None:

-                map_fn(fn_ptr, None)
+                map_fn(line, fn_ptr, None, None)

             elif fn_ret_arr is not None:
             elif fn_ret_arr is not None:

-                map_fn(fn_ret_arr, fn_ret_arr.group(4))
+                map_fn(line, fn_ret_arr, fn_ret_arr.group(4), None)

             elif reg_fn is not None:
             elif reg_fn is not None:

-                map_fn(reg_fn, None)
+                map_fn(line, reg_fn, None, None)

             elif const_val_regex is not None:
                 # TODO Map const variables
                 pass
             elif const_val_regex is not None:
                 # TODO Map const variables
                 pass


@@ -663,3 +1950,22 @@ public class bindings {
                 assert(line == "\n")
 
     out_java.write("}\n")
                 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")
+with open(sys.argv[4], "w") as out_c:
+    out_c.write(c_file_pfx)
+    for ty in c_array_class_caches:
+        if ty + "_clz" in c_file:
+            out_c.write("static jclass " + ty + "_clz = NULL;\n")
+    out_c.write("JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass _b) {\n")
+    for ty in c_array_class_caches:
+        if ty + "_clz" in c_file:
+            out_c.write("\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n")
+            out_c.write("\tCHECK(" + ty + "_clz != NULL);\n")
+            out_c.write("\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n")
+    out_c.write("}\n")
+    out_c.write(c_file)