Update Human object test to use SocketDescriptor traits (which worked the first time!)
[ldk-java] / genbindings.py
index 78bb2ad875d8761006b612b13758df3254f1202a..3f7a12ee23d402b00044cd967b4c27c308af2006 100755 (executable)
 #!/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)
 
+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:
-    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.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.arr_access = arr_access
+        self.subty = subty
+        self.pass_by_ref = is_ptr
+        self.requires_clone = None
 
 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)
+        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.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.arg_conv_cleanup = arg_conv_cleanup
         self.ret_conv = ret_conv
         self.ret_conv_name = ret_conv_name
+        self.to_hu_conv = to_hu_conv
+        self.to_hu_conv_name = to_hu_conv_name
+        self.from_hu_conv = from_hu_conv
 
     def print_ty(self):
-        out_c.write(self.c_ty)
+        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_c.write(" " + self.arg_name)
+            write_c(" " + self.arg_name)
         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
-        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()
-        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_hu_ty = "TwoTuple<"
+            if not ma.group(1).strip() in tuple_types:
+                assert java_c_types_none_allowed
+                return None
+            for idx, ty_info in enumerate(tuple_types[ma.group(1).strip()][0]):
+                if idx != 0:
+                    java_hu_ty = java_hu_ty + ", "
+                if ty_info.is_native_primitive:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty.title() # If we're a primitive, capitalize the first letter
+                else:
+                    java_hu_ty = java_hu_ty + ty_info.java_hu_ty
+            java_hu_ty = java_hu_ty + ">"
             c_ty = "jlong"
             fn_ty_arg = "J"
-            fn_arg = 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"
+            fn_ty_arg = "J"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+        else:
             java_ty = "long"
+            java_hu_ty = ma.group(1).strip().replace("LDKCResult", "Result").replace("LDK", "")
+            c_ty = "jlong"
+            fn_ty_arg = "J"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+
+    if fn_arg.startswith(" *") or fn_arg.startswith("*"):
+        fn_arg = fn_arg.replace("*", "").strip()
+        is_ptr = True
+        c_ty = "jlong"
+        java_ty = "long"
+        fn_ty_arg = "J"
+        is_primitive = False
+
+    var_is_arr = var_is_arr_regex.match(fn_arg)
+    if var_is_arr is not None or ret_arr_len is not None:
+        assert(not take_by_ptr)
+        assert(not is_ptr)
+        java_ty = java_ty + "[]"
+        c_ty = c_ty + "Array"
+        if var_is_arr is not None:
+            if var_is_arr.group(1) == "":
+                return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                    passed_as_ptr=False, is_ptr=False, var_name="arg", arr_len=var_is_arr.group(2), arr_access=arr_access, is_native_primitive=False)
+            return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2), arr_access=arr_access, is_native_primitive=False)
+
+    if java_hu_ty is None:
+        java_hu_ty = java_ty
+    return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_hu_ty=java_hu_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
+        is_ptr=is_ptr, var_name=fn_arg, arr_len=arr_len, arr_access=arr_access, is_native_primitive=is_primitive)
+
+fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
+fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
+reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
+clone_fns = set()
+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)
+        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,
-                    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:
@@ -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
-            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:
-                    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,
-                    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,
-                    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,
-                    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:
-                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);",
-                    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,
-                    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:
-            # 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:
+                        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,
-                            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,
-                        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,
-                    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_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()
+
         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 = []
+        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":
-                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.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)
 
+        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_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:
-                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:
-            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:
-            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:
-                    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:
-            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:
-            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):
-        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:
-                    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:
-                    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:
-                        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;
+import org.ldk.enums.*;
 
 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\");
-               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
 
-    fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
-    fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
-    reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
-    line_indicates_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;"))
+    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]*) {$")
     assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
     assert(struct_name_regex.match("typedef enum LDKNetwork {"))
+    struct_alias_regex = re.compile("^typedef (LDK[A-Za-z_0-9]*) (LDK[A-Za-z_0-9]*);$")
+    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:
-            #out_java.write("\t" + line)
             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
+                vec_ty = None
                 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_tuple = False
                 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
+                        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)
@@ -579,56 +1671,140 @@ public class bindings {
                         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)
-                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:
-                            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 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)
@@ -649,13 +1825,124 @@ public class bindings {
             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:
-                map_fn(fn_ptr, None)
+                map_fn(line, fn_ptr, None, 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:
-                map_fn(reg_fn, None)
+                map_fn(line, reg_fn, None, None)
             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")
+    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)