Merge pull request #18 from TheBlueMatt/main
[ldk-java] / java_strings.py
index 16f59b62dcbb940883d6cd6d388bd2a6aa9025c3..e00f513f717a97dc1f76a9f25c8964019b21299d 100644 (file)
@@ -1,8 +1,14 @@
 from bindingstypes import *
+from enum import Enum
 
-class Consts:
-    def __init__(self, DEBUG: bool, **kwargs):
+class Target(Enum):
+    JAVA = 1,
+    ANDROID = 2
 
+class Consts:
+    def __init__(self, DEBUG: bool, target: Target, **kwargs):
+        self.target = target
+        self.c_array_class_caches = set()
         self.c_type_map = dict(
             uint8_t = ['byte'],
             uint16_t = ['short'],
@@ -31,9 +37,21 @@ public class bindings {
                System.loadLibrary(\"lightningjni\");
                init(java.lang.Enum.class, VecOrSliceDef.class);
                init_class_cache();
+               if (!get_lib_version_string().equals(get_ldk_java_bindings_version()))
+                       throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
+               // Fetching the LDK versions from C also checks that the header and binaries match
+               get_ldk_c_bindings_version();
+               get_ldk_version();
        }
        static native void init(java.lang.Class c, java.lang.Class slicedef);
        static native void init_class_cache();
+       static native String get_lib_version_string();
+
+       public static String get_ldk_java_bindings_version() {
+               return "<git_version_ldk_garbagecollected>";
+       }
+       public static native String get_ldk_c_bindings_version();
+       public static native String get_ldk_version();
 
        public static native boolean deref_bool(long ptr);
        public static native long deref_long(long ptr);
@@ -49,6 +67,16 @@ public class bindings {
 
 """
 
+        self.bindings_footer = "}\n"
+
+        self.util_fn_pfx = """package org.ldk.structs;
+import org.ldk.impl.bindings;
+import java.util.Arrays;
+import org.ldk.enums.*;
+
+public class UtilMethods {
+"""
+        self.util_fn_sfx = "}"
         self.common_base = """package org.ldk.structs;
 import java.util.LinkedList;
 class CommonBase {
@@ -60,16 +88,45 @@ class CommonBase {
 """
 
         self.c_file_pfx = """#include \"org_ldk_impl_bindings.h\"
-#include <rust_types.h>
 #include <lightning.h>
 #include <string.h>
 #include <stdatomic.h>
 #include <stdlib.h>
+
+"""
+
+        if self.target == Target.ANDROID:
+            self.c_file_pfx = self.c_file_pfx + """
+#include <android/log.h>
+#define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
+
+#include <unistd.h>
+#include <pthread.h>
+static void* redirect_stderr(void* ignored) {
+       int pipes[2];
+       pipe(pipes);
+       dup2(pipes[1], STDERR_FILENO);
+       char buf[8192];
+       memset(buf, 0, 8192);
+       ssize_t len;
+       while ((len = read(pipes[0], buf, 8191)) > 0) {
+               DEBUG_PRINT("%s\\n", buf);
+               memset(buf, 0, 8192);
+       }
+       DEBUG_PRINT("End of stderr???\\n");
+       return 0;
+}
+void __attribute__((constructor)) spawn_stderr_redirection() {
+       pthread_t thread;
+       pthread_create(&thread, NULL, &redirect_stderr, NULL);
+}
 """
+        else:
+            self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 
         if not DEBUG:
             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
-#define FREE(p) if ((long)(p) > 1024) { free(p); }
+#define FREE(p) if ((uint64_t)(p) > 1024) { free(p); }
 #define DO_ASSERT(a) (void)(a)
 #define CHECK(a)
 """
@@ -80,12 +137,66 @@ class CommonBase {
 // Assert a is true or do nothing
 #define CHECK(a) DO_ASSERT(a)
 
+void __attribute__((constructor)) debug_log_version() {
+       if (check_get_ldk_version() == NULL)
+               DEBUG_PRINT("LDK version did not match the header we built against\\n");
+       if (check_get_ldk_bindings_version() == NULL)
+               DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
+       DEBUG_PRINT("Loaded LDK-Java Bindings with LDK %s and LDK-C-Bindings %s\\n", check_get_ldk_version(), check_get_ldk_bindings_version());
+}
+
 // 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>
+"""
+
+            if self.target == Target.ANDROID:
+                self.c_file_pfx = self.c_file_pfx + """
+#include <unwind.h>
+#include <dlfcn.h>
+
+// Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
+// symbols, so we only use it on Android, where execinfo.h is unavailable.
+
+struct BacktraceState {
+       void** current;
+       void** end;
+};
+static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
+       struct BacktraceState* state = (struct BacktraceState*)arg;
+       uintptr_t pc = _Unwind_GetIP(context);
+       if (pc) {
+               if (state->current == state->end) {
+                       return _URC_END_OF_STACK;
+               } else {
+                       *state->current++ = (void*)(pc);
+               }
+       }
+       return _URC_NO_REASON;
+}
+
+int backtrace(void** buffer, int max) {
+       struct BacktraceState state = { buffer, buffer + max };
+       _Unwind_Backtrace(unwind_callback, &state);
+       return state.current - buffer;
+}
+
+void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
+       for (int idx = 0; idx < count; ++idx) {
+               Dl_info info;
+               if (dladdr(buffer[idx], &info) && info.dli_sname) {
+                       DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
+               } else {
+                       DEBUG_PRINT("%p: ???", buffer[idx]);
+               }
+       }
+}
+"""
+            else:
+                self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
+            self.c_file_pfx = self.c_file_pfx + """
 #include <unistd.h>
 static mtx_t allocation_mtx;
 
@@ -100,16 +211,18 @@ typedef struct allocation {
        const char* struct_name;
        void* bt[BT_MAX];
        int bt_len;
+       unsigned long alloc_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) {
+static void new_allocation(void* res, const char* struct_name, size_t len) {
        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);
+       new_alloc->alloc_len = len;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        new_alloc->next = allocation_ll;
        allocation_ll = new_alloc;
@@ -117,7 +230,7 @@ static void new_allocation(void* res, const char* struct_name) {
 }
 static void* MALLOC(size_t len, const char* struct_name) {
        void* res = __real_malloc(len);
-       new_allocation(res, struct_name);
+       new_allocation(res, struct_name, len);
        return res;
 }
 void __real_free(void* ptr);
@@ -128,11 +241,11 @@ static void alloc_freed(void* ptr) {
        while (it->ptr != ptr) {
                p = it; it = it->next;
                if (it == NULL) {
-                       fprintf(stderr, "Tried to free unknown pointer %p at:\\n", ptr);
+                       DEBUG_PRINT("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");
+                       DEBUG_PRINT("\\n\\n");
                        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
                        return; // addrsan should catch malloc-unknown and print more info than we have
                }
@@ -143,19 +256,19 @@ static void alloc_freed(void* 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
+       if ((uint64_t)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");
+       new_allocation(res, "malloc call", len);
        return res;
 }
 void* __wrap_calloc(size_t nmemb, size_t len) {
        void* res = __real_calloc(nmemb, len);
-       new_allocation(res, "calloc call");
+       new_allocation(res, "calloc call", len);
        return res;
 }
 void __wrap_free(void* ptr) {
@@ -168,7 +281,7 @@ 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");
+       new_allocation(res, "realloc call", len);
        return res;
 }
 void __wrap_reallocarray(void* ptr, size_t new_sz) {
@@ -177,12 +290,21 @@ void __wrap_reallocarray(void* ptr, size_t new_sz) {
 }
 
 void __attribute__((destructor)) check_leaks() {
+       unsigned long alloc_count = 0;
+       unsigned long alloc_size = 0;
+       DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
+       DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
+       DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
        for (allocation* a = allocation_ll; a != NULL; a = a->next) {
-               fprintf(stderr, "%s %p remains:\\n", a->struct_name, a->ptr);
+               DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
                backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
-               fprintf(stderr, "\\n\\n");
+               DEBUG_PRINT("\\n\\n");
+               alloc_count++;
+               alloc_size += a->alloc_len;
        }
-       DO_ASSERT(allocation_ll == NULL);
+       DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
+       DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
+       DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 }
 """
         self.c_file_pfx = self.c_file_pfx + """
@@ -218,27 +340,27 @@ JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (J
        (*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) {
+JNIEXPORT int64_t 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;
+       return (uint64_t)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);
+       return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (uint64_t)&slice);
 }
-JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
+JNIEXPORT int64_t 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;
+       return (uint64_t)txdata;
 }
 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
        LDKTransaction *tx = (LDKTransaction*)ptr;
@@ -253,9 +375,9 @@ JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env
        _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;
+       return (uint64_t)vec->datalen;
 }
-JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * env, jclass _b) {
+JNIEXPORT int64_t 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");
@@ -264,7 +386,7 @@ JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
        vec->data = NULL;
        vec->datalen = 0;
-       return (long)vec;
+       return (uint64_t)vec;
 }
 
 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
@@ -279,6 +401,39 @@ _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 typedef jlongArray int64_tArray;
 typedef jbyteArray int8_tArray;
 
+static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
+       // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
+       char* conv_buf = MALLOC(len + 1, "str conv buf");
+       memcpy(conv_buf, chars, len);
+       conv_buf[len] = 0;
+       jstring ret = (*env)->NewStringUTF(env, conv_buf);
+       FREE(conv_buf);
+       return ret;
+}
+static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
+       uint64_t str_len = (*env)->GetStringUTFLength(env, str);
+       char* newchars = MALLOC(str_len + 1, "String chars");
+       const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
+       memcpy(newchars, jchars, str_len);
+       newchars[str_len] = 0;
+       (*env)->ReleaseStringUTFChars(env, str, jchars);
+       LDKStr res = {
+               .chars = newchars,
+               .len = str_len,
+               .chars_is_owned = true
+       };
+       return res;
+}
+
+JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
+       return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
+}
+JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
+       return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
+}
+JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
+       return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
+}
 """
 
         self.hu_struct_file_prefix = """package org.ldk.structs;
@@ -288,10 +443,8 @@ import org.ldk.enums.*;
 import org.ldk.util.*;
 import java.util.Arrays;
 
-@SuppressWarnings("unchecked") // We correctly assign various generic arrays
 """
         self.c_fn_ty_pfx = "JNIEXPORT "
-        self.c_fn_name_pfx = "JNICALL Java_org_ldk_impl_bindings_"
         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
         self.file_ext = ".java"
         self.ptr_c_ty = "int64_t"
@@ -299,13 +452,33 @@ import java.util.Arrays;
         self.result_c_ty = "jclass"
         self.ptr_arr = "jobjectArray"
         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
-        self.get_native_arr_ptr_call = ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 
-    def release_native_arr_ptr_call(self, arr_var, arr_ptr_var):
-        return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
+    def construct_jenv(self):
+        res =  "JNIEnv *env;\n"
+        res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
+        res += "if (get_jenv_res == JNI_EDETACHED) {\n"
+        res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
+        res += "} else {\n"
+        res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
+        res += "}\n"
+        return res
+    def deconstruct_jenv(self):
+        res = "if (get_jenv_res == JNI_EDETACHED) {\n"
+        res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
+        res += "}\n"
+        return res
+
+    def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
+        if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
+            return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
+        return None
     def create_native_arr_call(self, arr_len, ty_info):
         if ty_info.c_ty == "int8_tArray":
             return "(*env)->NewByteArray(env, " + arr_len + ")"
+        elif ty_info.subty.c_ty.endswith("Array"):
+            clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
+            self.c_array_class_caches.add(clz_var)
+            return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
         else:
             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
@@ -328,32 +501,52 @@ import java.util.Arrays;
             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
         else:
             assert False # Only called if above is None
+    def get_native_arr_ptr_call(self, ty_info):
+        if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
+            return None
+        return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
+    def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
+        if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
+            return None
+        return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
         if ty_info.c_ty == "int8_tArray":
             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
         else:
             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 
-    def init_str(self, c_array_class_caches):
+    def str_ref_to_native_call(self, var_name, str_len):
+        return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
+    def str_ref_to_c_call(self, var_name):
+        return "java_to_owned_str(env, " + var_name + ")"
+
+    def c_fn_name_define_pfx(self, fn_name, has_args):
+        if has_args:
+            return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
+        return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
+
+    def init_str(self):
         res = ""
-        for ty in c_array_class_caches:
+        for ty in sorted(self.c_array_class_caches):
             res = res + "static jclass " + ty + "_clz = NULL;\n"
         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
-        for ty in c_array_class_caches:
+        for ty in sorted(self.c_array_class_caches):
             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
         res = res + "}\n"
         return res
 
-    def native_c_unitary_enum_map(self, struct_name, variants):
+    def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
         out_java_enum = "package org.ldk.enums;\n\n"
         out_java = ""
         out_c = ""
-        out_c = out_c + "static inline " + struct_name + " " + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
+        out_c = out_c + "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
         out_c = out_c + "\tswitch ((*env)->CallIntMethod(env, clz, ordinal_meth)) {\n"
 
-        out_java_enum = out_java_enum + "public enum " + struct_name + " {\n"
+        if enum_doc_comment is not None:
+            out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
+        out_java_enum += "public enum " + struct_name + " {\n"
         ord_v = 0
         for var in variants:
             out_java_enum = out_java_enum + "\t" + var + ",\n"
@@ -377,7 +570,7 @@ import java.util.Arrays;
             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
         out_c = out_c + "}\n"
-        out_c = out_c + "static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n"
+        out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
         out_c = out_c + "\tswitch (val) {\n"
         ord_v = 0
         for var in variants:
@@ -403,7 +596,10 @@ import java.util.Arrays;
         out_c = out_c + self.c_fn_ty_pfx + "void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (" + self.c_fn_args_pfx + ") {\n"
         for var_name in variants:
             out_c = out_c + "\t" + struct_name + "_" + var_name + "_class =\n"
-            out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n"
+            if self.target == Target.ANDROID:
+                out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
+            else:
+                out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n"
             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
             out_c = out_c + "\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n"
             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
@@ -419,24 +615,27 @@ import java.util.Arrays;
             ret = ret + ", " + param
         return ret + ")"
 
-    def native_c_map_trait(self, struct_name, field_vars, field_fns):
+    def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
         out_java_trait = ""
         out_java = ""
 
         # First generate most of the Java code, note that we need information about java method argument strings for C
         out_java_trait = out_java_trait + self.hu_struct_file_prefix
+        if trait_doc_comment is not None:
+            out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
+        out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
             else:
                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
         out_java_trait = out_java_trait + ") {\n"
         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 if var.from_hu_conv is not None:
                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
@@ -446,10 +645,10 @@ import java.util.Arrays;
                 out_java_trait = out_java_trait + ", " + var[1]
         out_java_trait = out_java_trait + "));\n"
         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
-                    out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1] + ";\n"
+                    out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
             else:
                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
@@ -461,7 +660,7 @@ import java.util.Arrays;
 
         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 var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
             else:
@@ -478,6 +677,7 @@ import java.util.Arrays;
             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
+                out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 
                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
@@ -520,9 +720,6 @@ import java.util.Arrays;
                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
                             java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.from_hu_conv[1].replace("this", "impl_holder.held") + ";\n"
                         #if fn_line.ret_ty_info.rust_obj in result_types:
-                        # XXX: We need to handle this in conversion logic so that its cross-language!
-                            # 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"
@@ -532,27 +729,37 @@ import java.util.Arrays;
             if isinstance(var, ConvInfo):
                 java_trait_constr = java_trait_constr + ", " + var.arg_name
             else:
-                java_trait_constr = java_trait_constr + ", " + var[1] + ".new_impl(" + var[1] + "_impl).bindings_instance"
+                java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
+                for suparg in var[2]:
+                    if isinstance(suparg, ConvInfo):
+                        java_trait_constr += ", " + suparg.arg_name
+                    else:
+                        java_trait_constr += ", " + suparg[1]
+                java_trait_constr += ").bindings_instance"
+                for suparg in var[2]:
+                    if isinstance(suparg, ConvInfo):
+                        java_trait_constr += ", " + suparg.arg_name
+                    else:
+                        java_trait_constr += ", " + suparg[1]
         out_java_trait = out_java_trait + "\t}\n"
         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 
         out_java = out_java + "\t}\n"
 
         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
             else:
                 out_java = out_java + ", " + var[0] + " " + var[1]
         out_java = out_java + ");\n"
-        out_java = out_java + "\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n"
 
         # Now that we've written out our java code (and created java_meths), generate C
         out_c = "typedef struct " + struct_name + "_JCalls {\n"
         out_c = out_c + "\tatomic_size_t refcnt;\n"
         out_c = out_c + "\tJavaVM *vm;\n"
         out_c = out_c + "\tjweak o;\n"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 # We're a regular ol' field
                 pass
@@ -569,16 +776,16 @@ import java.util.Arrays;
                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
-                out_c = out_c + "\t\tJNIEnv *env;\n"
-                out_c = out_c + "\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n"
+                out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
+                out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
                 out_c = out_c + "\t\tFREE(j_calls);\n"
                 out_c = out_c + "\t}\n}\n"
 
         for idx, fn_line in enumerate(field_fns):
             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
-                out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_jcall("
+                out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
                 if fn_line.self_is_const:
                     out_c = out_c + "const void* this_arg"
                 else:
@@ -589,8 +796,7 @@ import java.util.Arrays;
 
                 out_c = out_c + ") {\n"
                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
-                out_c = out_c + "\tJNIEnv *env;\n"
-                out_c = out_c + "\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n"
+                out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 
                 for arg_info in fn_line.args_ty:
                     if arg_info.ret_conv is not None:
@@ -600,9 +806,11 @@ import java.util.Arrays;
 
                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
-                    out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " arg = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
+                    out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
+                elif fn_line.ret_ty_info.c_ty == "void":
+                    out_c += "\t(*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
                 elif not fn_line.ret_ty_info.passed_as_ptr:
-                    out_c = out_c + "\treturn (*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
+                    out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
                 else:
                     out_c = out_c + "\t" + fn_line.ret_ty_info.rust_obj + "* ret = (" + fn_line.ret_ty_info.rust_obj + "*)(*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 
@@ -613,7 +821,13 @@ import java.util.Arrays;
                         out_c = out_c + ", " + arg_info.arg_name
                 out_c = out_c + ");\n"
                 if fn_line.ret_ty_info.arg_conv is not None:
-                    out_c = out_c + "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
+                    out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
+                    out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
+                    out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
+                else:
+                    out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
+                    if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
+                        out_c += "\treturn ret;\n"
 
                 out_c = out_c + "}\n"
 
@@ -628,7 +842,7 @@ import java.util.Arrays;
         out_c = out_c + "}\n"
 
         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
             else:
@@ -647,14 +861,14 @@ import java.util.Arrays;
                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
 
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo) and var.arg_conv is not None:
                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
         for fn_line in field_fns:
             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
-                out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_jcall,\n"
+                out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
             elif fn_line.fn_name == "free":
                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
             else:
@@ -668,16 +882,22 @@ import java.util.Arrays;
                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
             else:
-                out_c = out_c + "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1] + "),\n"
+                out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
+                for suparg in var[2]:
+                    if isinstance(suparg, ConvInfo):
+                        out_c = out_c + ", " + suparg.arg_name
+                    else:
+                        out_c = out_c + ", " + suparg[1]
+                out_c += "),\n"
         out_c = out_c + "\t};\n"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if not isinstance(var, ConvInfo):
                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
         out_c = out_c + "\treturn ret;\n"
         out_c = out_c + "}\n"
 
-        out_c = out_c + self.c_fn_ty_pfx + "long " + self.c_fn_name_pfx + struct_name.replace("_", "_1") + "_1new (" + self.c_fn_args_pfx + ", jobject o"
-        for var in field_vars:
+        out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
             else:
@@ -685,19 +905,13 @@ import java.util.Arrays;
         out_c = out_c + ") {\n"
         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
-        for var in field_vars:
+        for var in flattened_field_vars:
             if isinstance(var, ConvInfo):
                 out_c = out_c + ", " + var.arg_name
             else:
                 out_c = out_c + ", " + var[1]
         out_c = out_c + ");\n"
-        out_c = out_c + "\treturn (long)res_ptr;\n"
-        out_c = out_c + "}\n"
-
-        out_c = out_c + self.c_fn_ty_pfx + "jobject " + self.c_fn_name_pfx + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (" + self.c_fn_args_pfx + ", " + self.ptr_c_ty + " val) {\n"
-        out_c = out_c + "\tjobject ret = (*env)->NewLocalRef(env, ((" + struct_name + "_JCalls*)val)->o);\n"
-        out_c = out_c + "\tCHECK(ret != NULL);\n"
-        out_c = out_c + "\treturn ret;\n"
+        out_c = out_c + "\treturn (uint64_t)res_ptr;\n"
         out_c = out_c + "}\n"
 
         return (out_java, out_java_trait, out_c)
@@ -708,19 +922,21 @@ import java.util.Arrays;
         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_arg);\n}"
         return base_conv
 
-    def map_complex_enum(self, struct_name, variant_list, camel_to_snake):
-        java_hu_type = struct_name.replace("LDK", "")
+    def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
+        java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
         out_java_enum = ""
         out_java = ""
         out_c = ""
 
         out_java_enum += (self.hu_struct_file_prefix)
+        out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
+        out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
         out_java_enum += ("\t\tsuper.finalize();\n")
-        out_java_enum += ("\t\tif (ptr != 0) { bindings." + java_hu_type + "_free(ptr); }\n")
+        out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
         out_java_enum += ("\t}\n")
         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
@@ -740,8 +956,19 @@ import java.util.Arrays;
             init_meth_body = ""
             hu_conv_body = ""
             for idx, field_ty in enumerate(var.fields):
-                out_java += ("\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 idx > 0:
+                    init_meth_params = init_meth_params + ", "
+
+                if field_ty.java_hu_ty == var.var_name:
+                    field_path = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
+                    out_java += "\t\t\tpublic " + field_path + " " + field_ty.arg_name + ";\n"
+                    java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_path + " " + field_ty.arg_name + ";\n"
+                    init_meth_params = init_meth_params + field_path + " " + field_ty.arg_name
+                else:
+                    out_java += "\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"
+                    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 + "; "
                 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"
@@ -749,10 +976,6 @@ import java.util.Arrays;
                 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 > 0:
-                    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 +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
             out_java +=  (init_meth_body)
             out_java +=  ("}\n")
@@ -771,8 +994,8 @@ import java.util.Arrays;
 
         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
 
-        out_c += (self.c_fn_ty_pfx + self.c_complex_enum_pass_ty(struct_name) + " " + self.c_fn_name_pfx + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (" + self.c_fn_args_pfx + ", " + self.ptr_c_ty + " ptr) {\n")
-        out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
+        out_c += (self.c_fn_ty_pfx + self.c_complex_enum_pass_ty(struct_name) + " " + self.c_fn_name_define_pfx(struct_name + "_ref_from_ptr", True) + self.ptr_c_ty + " ptr) {\n")
+        out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)(ptr & ~1);\n")
         out_c += ("\tswitch(obj->tag) {\n")
         for var in variant_list:
             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
@@ -780,21 +1003,28 @@ import java.util.Arrays;
             for idx, field_map in enumerate(var.fields):
                 if field_map.ret_conv is not None:
                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
-                    out_c += ("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
+                    if var.tuple_variant:
+                        out_c += "obj->" + camel_to_snake(var.var_name)
+                    else:
+                        out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
                     c_params.append(field_map.ret_conv_name)
                 else:
-                    c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
+                    if var.tuple_variant:
+                        c_params.append("obj->" + camel_to_snake(var.var_name))
+                    else:
+                        c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
             out_c += ("\t\t}\n")
         out_c += ("\t\tdefault: abort();\n")
         out_c += ("\t}\n}\n")
-        out_java_enum += ("}\n")
         return (out_java, out_java_enum, out_c)
 
-    def map_opaque_struct(self, struct_name):
+    def map_opaque_struct(self, struct_name, struct_doc_comment):
         out_opaque_struct_human = ""
         out_opaque_struct_human += self.hu_struct_file_prefix
+        out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
+        out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
         out_opaque_struct_human += ("public class " + struct_name.replace("LDK","") + " extends CommonBase")
         if struct_name.startswith("LDKLocked"):
             out_opaque_struct_human += (" implements AutoCloseable")
@@ -809,3 +1039,157 @@ import java.util.Arrays;
         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
         out_opaque_struct_human += ("\t}\n\n")
         return out_opaque_struct_human
+
+
+    def map_function(self, argument_types, c_call_string, method_name, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
+        out_java = ""
+        out_c = ""
+        out_java_struct = None
+
+        out_java += ("\tpublic static native ")
+        out_c += (self.c_fn_ty_pfx)
+        out_c += (return_type_info.c_ty)
+        out_java += (return_type_info.java_ty)
+        if return_type_info.ret_conv is not None:
+            ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
+        out_java += (" " + method_name + "(")
+        have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
+        out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
+
+        for idx, arg_conv_info in enumerate(argument_types):
+            if idx != 0:
+                out_java += (", ")
+                out_c += (", ")
+            if arg_conv_info.c_ty != "void":
+                out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
+                out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
+
+        out_java_struct = ""
+        if not args_known:
+            out_java_struct += ("\t// Skipped " + method_name + "\n")
+        else:
+            meth_n = method_name[len(struct_meth) + 1 if len(struct_meth) != 0 else 0:].strip("_")
+            if doc_comment is not None:
+                out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
+            if not takes_self:
+                if meth_n == "new":
+                    out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
+                elif meth_n == "default":
+                    out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
+                else:
+                    out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
+            else:
+                out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
+            for idx, arg in enumerate(argument_types):
+                if idx != 0:
+                    if not takes_self or idx > 1:
+                        out_java_struct += ", "
+                elif takes_self:
+                    continue
+                if arg.java_ty != "void":
+                    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 += (", ")
+                            out_java_struct += (
+                                explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
+                    else:
+                        out_java_struct += (arg.java_hu_ty + " " + arg.arg_name)
+        out_java += (");\n")
+        out_c += (") {\n")
+        if out_java_struct is not None:
+            out_java_struct += (") {\n")
+        for info in argument_types:
+            if info.arg_conv is not None:
+                out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
+        if return_type_info.ret_conv is not None:
+            out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
+        elif return_type_info.c_ty != "void":
+            out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
+        else:
+            out_c += ("\t")
+        if c_call_string is None:
+            out_c += (method_name + "(")
+        else:
+            out_c += (c_call_string)
+        for idx, info in enumerate(argument_types):
+            if info.arg_conv_name is not None:
+                if idx != 0:
+                    out_c += (", ")
+                elif c_call_string is not None:
+                    continue
+                out_c += (info.arg_conv_name)
+        out_c += (")")
+        if return_type_info.ret_conv is not None:
+            out_c += (ret_conv_sfx.replace('\n', '\n\t'))
+        else:
+            out_c += (";")
+        for info in argument_types:
+            if info.arg_conv_cleanup is not None:
+                out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
+        if return_type_info.ret_conv is not None:
+            out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
+        elif return_type_info.c_ty != "void":
+            out_c += ("\n\treturn ret_val;")
+        out_c += ("\n}\n\n")
+
+        if args_known:
+            out_java_struct += ("\t\t")
+            if return_type_info.java_ty != "void":
+                out_java_struct += (return_type_info.java_ty + " ret = ")
+            out_java_struct += ("bindings." + method_name + "(")
+            for idx, info in enumerate(argument_types):
+                if idx != 0:
+                    out_java_struct += (", ")
+                if idx == 0 and takes_self:
+                    out_java_struct += ("this.ptr")
+                elif info.arg_name in default_constructor_args:
+                    out_java_struct += ("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 += (", ")
+                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
+                        if explode_arg.from_hu_conv is not None:
+                            out_java_struct += (
+                                explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
+                        else:
+                            out_java_struct += (expl_arg_name)
+                    out_java_struct += (")")
+                elif info.from_hu_conv is not None:
+                    out_java_struct += (info.from_hu_conv[0])
+                else:
+                    out_java_struct += (info.arg_name)
+            out_java_struct += (");\n")
+            if return_type_info.to_hu_conv is not None:
+                if not takes_self:
+                    out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
+                                                                                                               return_type_info.to_hu_conv_name) + "\n")
+                else:
+                    out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
+
+            for idx, info in enumerate(argument_types):
+                if idx == 0 and takes_self:
+                    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
+                        if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
+                            out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
+                                                                                               expl_arg_name).replace(
+                                "this", return_type_info.to_hu_conv_name) + ";\n")
+                elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
+                    if not takes_self and return_type_info.to_hu_conv_name is not None:
+                        out_java_struct += (
+                            "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
+                    else:
+                        out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
+
+            if takes_self and not takes_self_as_ref:
+                out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
+            if return_type_info.to_hu_conv_name is not None:
+                out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
+            elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
+                out_java_struct += ("\t\treturn ret;\n")
+            out_java_struct += ("\t}\n\n")
+
+        return (out_java, out_c, out_java_struct)