_ Git - ldk-java/blob - java_strings.py

   1 from bindingstypes import *
   2 from enum import Enum
   3 import sys
   4
   5 class Target(Enum):
   6     JAVA = 1,
   7     ANDROID = 2
   8
   9 class Consts:
  10     def __init__(self, DEBUG: bool, target: Target, **kwargs):
  11         self.target = target
  12         self.c_array_class_caches = set()
  13         self.c_type_map = dict(
  14             uint8_t = ['byte'],
  15             uint16_t = ['short'],
  16             uint32_t = ['int'],
  17             uint64_t = ['long'],
  18         )
  19
  20         self.to_hu_conv_templates = dict(
  21             ptr = '{human_type} {var_name}_hu_conv = new {human_type}(null, {var_name});',
  22             default = '{human_type} {var_name}_hu_conv = new {human_type}(null, {var_name});'
  23         )
  24
  25         self.bindings_header = """package org.ldk.impl;
  26 import org.ldk.enums.*;
  27
  28 public class bindings {
  29         public static class VecOrSliceDef {
  30                 public long dataptr;
  31                 public long datalen;
  32                 public long stride;
  33                 public VecOrSliceDef(long dataptr, long datalen, long stride) {
  34                         this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
  35                 }
  36         }
  37         static {
  38                 System.loadLibrary(\"lightningjni\");
  39                 init(java.lang.Enum.class, VecOrSliceDef.class);
  40                 init_class_cache();
  41                 if (!get_lib_version_string().equals(get_ldk_java_bindings_version()))
  42                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
  43                 // Fetching the LDK versions from C also checks that the header and binaries match
  44                 get_ldk_c_bindings_version();
  45                 get_ldk_version();
  46         }
  47         static native void init(java.lang.Class c, java.lang.Class slicedef);
  48         static native void init_class_cache();
  49         static native String get_lib_version_string();
  50
  51         public static String get_ldk_java_bindings_version() {
  52                 return "<git_version_ldk_garbagecollected>";
  53         }
  54         public static native String get_ldk_c_bindings_version();
  55         public static native String get_ldk_version();
  56
  57         public static native boolean deref_bool(long ptr);
  58         public static native long deref_long(long ptr);
  59         public static native void free_heap_ptr(long ptr);
  60         public static native byte[] read_bytes(long ptr, long len);
  61         public static native byte[] get_u8_slice_bytes(long slice_ptr);
  62         public static native long bytes_to_u8_vec(byte[] bytes);
  63         public static native long new_txpointer_copy_data(byte[] txdata);
  64         public static native void txpointer_free(long ptr);
  65         public static native byte[] txpointer_get_buffer(long ptr);
  66         public static native long vec_slice_len(long vec);
  67         public static native long new_empty_slice_vec();
  68
  69 """
  70
  71         self.bindings_footer = "}\n"
  72
  73         self.util_fn_pfx = """package org.ldk.structs;
  74 import org.ldk.impl.bindings;
  75 import java.util.Arrays;
  76 import org.ldk.enums.*;
  77
  78 public class UtilMethods {
  79 """
  80         self.util_fn_sfx = "}"
  81         self.common_base = """package org.ldk.structs;
  82 import java.util.LinkedList;
  83 class CommonBase {
  84         long ptr;
  85         LinkedList<Object> ptrs_to = new LinkedList();
  86         protected CommonBase(long ptr) { this.ptr = ptr; }
  87 }
  88 """
  89
  90         self.c_file_pfx = """#include <jni.h>
  91 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
  92 #define int64_t jlong
  93 #include \"org_ldk_impl_bindings.h\"
  94 #include <lightning.h>
  95 #include <string.h>
  96 #include <stdatomic.h>
  97 #include <stdlib.h>
  98
  99 """
 100
 101         if self.target == Target.ANDROID:
 102             self.c_file_pfx = self.c_file_pfx + """
 103 #include <android/log.h>
 104 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
 105
 106 #include <unistd.h>
 107 #include <pthread.h>
 108 static void* redirect_stderr(void* ignored) {
 109         int pipes[2];
 110         pipe(pipes);
 111         dup2(pipes[1], STDERR_FILENO);
 112         char buf[8192];
 113         memset(buf, 0, 8192);
 114         ssize_t len;
 115         while ((len = read(pipes[0], buf, 8191)) > 0) {
 116                 DEBUG_PRINT("%s\\n", buf);
 117                 memset(buf, 0, 8192);
 118         }
 119         DEBUG_PRINT("End of stderr???\\n");
 120         return 0;
 121 }
 122 void __attribute__((constructor)) spawn_stderr_redirection() {
 123         pthread_t thread;
 124         pthread_create(&thread, NULL, &redirect_stderr, NULL);
 125 }
 126 """
 127         else:
 128             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 129
 130         if not DEBUG or sys.platform == "darwin":
 131             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
 132 #define FREE(p) if ((uint64_t)(p) > 1024) { free(p); }
 133 """
 134         if not DEBUG:
 135             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
 136 #define CHECK(a)
 137 """
 138         if DEBUG:
 139             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
 140 // Always run a, then assert it is true:
 141 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 142 // Assert a is true or do nothing
 143 #define CHECK(a) DO_ASSERT(a)
 144
 145 void __attribute__((constructor)) debug_log_version() {
 146         if (check_get_ldk_version() == NULL)
 147                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
 148         if (check_get_ldk_bindings_version() == NULL)
 149                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
 150         DEBUG_PRINT("Loaded LDK-Java Bindings with LDK %s and LDK-C-Bindings %s\\n", check_get_ldk_version(), check_get_ldk_bindings_version());
 151 }
 152 """
 153
 154             if sys.platform != "darwin":
 155                 self.c_file_pfx += """
 156 // Running a leak check across all the allocations and frees of the JDK is a mess,
 157 // so instead we implement our own naive leak checker here, relying on the -wrap
 158 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
 159 // and free'd in Rust or C across the generated bindings shared library.
 160 #include <threads.h>
 161 """
 162
 163                 if self.target == Target.ANDROID:
 164                     self.c_file_pfx = self.c_file_pfx + """
 165 #include <unwind.h>
 166 #include <dlfcn.h>
 167
 168 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
 169 // symbols, so we only use it on Android, where execinfo.h is unavailable.
 170
 171 struct BacktraceState {
 172         void** current;
 173         void** end;
 174 };
 175 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
 176         struct BacktraceState* state = (struct BacktraceState*)arg;
 177         uintptr_t pc = _Unwind_GetIP(context);
 178         if (pc) {
 179                 if (state->current == state->end) {
 180                         return _URC_END_OF_STACK;
 181                 } else {
 182                         *state->current++ = (void*)(pc);
 183                 }
 184         }
 185         return _URC_NO_REASON;
 186 }
 187
 188 int backtrace(void** buffer, int max) {
 189         struct BacktraceState state = { buffer, buffer + max };
 190         _Unwind_Backtrace(unwind_callback, &state);
 191         return state.current - buffer;
 192 }
 193
 194 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
 195         for (int idx = 0; idx < count; ++idx) {
 196                 Dl_info info;
 197                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
 198                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
 199                 } else {
 200                         DEBUG_PRINT("%p: ???", buffer[idx]);
 201                 }
 202         }
 203 }
 204 """
 205                 else:
 206                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
 207                 self.c_file_pfx = self.c_file_pfx + """
 208 #include <unistd.h>
 209 static mtx_t allocation_mtx;
 210
 211 void __attribute__((constructor)) init_mtx() {
 212         DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
 213 }
 214
 215 #define BT_MAX 128
 216 typedef struct allocation {
 217         struct allocation* next;
 218         void* ptr;
 219         const char* struct_name;
 220         void* bt[BT_MAX];
 221         int bt_len;
 222         unsigned long alloc_len;
 223 } allocation;
 224 static allocation* allocation_ll = NULL;
 225
 226 void* __real_malloc(size_t len);
 227 void* __real_calloc(size_t nmemb, size_t len);
 228 static void new_allocation(void* res, const char* struct_name, size_t len) {
 229         allocation* new_alloc = __real_malloc(sizeof(allocation));
 230         new_alloc->ptr = res;
 231         new_alloc->struct_name = struct_name;
 232         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
 233         new_alloc->alloc_len = len;
 234         DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
 235         new_alloc->next = allocation_ll;
 236         allocation_ll = new_alloc;
 237         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
 238 }
 239 static void* MALLOC(size_t len, const char* struct_name) {
 240         void* res = __real_malloc(len);
 241         new_allocation(res, struct_name, len);
 242         return res;
 243 }
 244 void __real_free(void* ptr);
 245 static void alloc_freed(void* ptr) {
 246         allocation* p = NULL;
 247         DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
 248         allocation* it = allocation_ll;
 249         while (it->ptr != ptr) {
 250                 p = it; it = it->next;
 251                 if (it == NULL) {
 252                         DEBUG_PRINT("Tried to free unknown pointer %p at:\\n", ptr);
 253                         void* bt[BT_MAX];
 254                         int bt_len = backtrace(bt, BT_MAX);
 255                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 256                         DEBUG_PRINT("\\n\\n");
 257                         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
 258                         return; // addrsan should catch malloc-unknown and print more info than we have
 259                 }
 260         }
 261         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
 262         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
 263         DO_ASSERT(it->ptr == ptr);
 264         __real_free(it);
 265 }
 266 static void FREE(void* ptr) {
 267         if ((uint64_t)ptr < 1024) return; // Rust loves to create pointers to the NULL page for dummys
 268         alloc_freed(ptr);
 269         __real_free(ptr);
 270 }
 271
 272 void* __wrap_malloc(size_t len) {
 273         void* res = __real_malloc(len);
 274         new_allocation(res, "malloc call", len);
 275         return res;
 276 }
 277 void* __wrap_calloc(size_t nmemb, size_t len) {
 278         void* res = __real_calloc(nmemb, len);
 279         new_allocation(res, "calloc call", len);
 280         return res;
 281 }
 282 void __wrap_free(void* ptr) {
 283         if (ptr == NULL) return;
 284         alloc_freed(ptr);
 285         __real_free(ptr);
 286 }
 287
 288 void* __real_realloc(void* ptr, size_t newlen);
 289 void* __wrap_realloc(void* ptr, size_t len) {
 290         if (ptr != NULL) alloc_freed(ptr);
 291         void* res = __real_realloc(ptr, len);
 292         new_allocation(res, "realloc call", len);
 293         return res;
 294 }
 295 void __wrap_reallocarray(void* ptr, size_t new_sz) {
 296         // Rust doesn't seem to use reallocarray currently
 297         DO_ASSERT(false);
 298 }
 299
 300 void __attribute__((destructor)) check_leaks() {
 301         unsigned long alloc_count = 0;
 302         unsigned long alloc_size = 0;
 303         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
 304         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 305         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 306         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
 307                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
 308                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
 309                 DEBUG_PRINT("\\n\\n");
 310                 alloc_count++;
 311                 alloc_size += a->alloc_len;
 312         }
 313         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
 314         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 315         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 316 }
 317 """
 318         self.c_file_pfx = self.c_file_pfx + """
 319 static jmethodID ordinal_meth = NULL;
 320 static jmethodID slicedef_meth = NULL;
 321 static jclass slicedef_cls = NULL;
 322 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
 323         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 324         CHECK(ordinal_meth != NULL);
 325         slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
 326         CHECK(slicedef_meth != NULL);
 327         slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
 328         CHECK(slicedef_cls != NULL);
 329 }
 330
 331 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
 332         return *((bool*)ptr);
 333 }
 334 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
 335         return *((long*)ptr);
 336 }
 337 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
 338         FREE((void*)ptr);
 339 }
 340 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * env, jclass _b, jlong ptr, jlong len) {
 341         jbyteArray ret_arr = (*env)->NewByteArray(env, len);
 342         (*env)->SetByteArrayRegion(env, ret_arr, 0, len, (unsigned char*)ptr);
 343         return ret_arr;
 344 }
 345 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * env, jclass _b, jlong slice_ptr) {
 346         LDKu8slice *slice = (LDKu8slice*)slice_ptr;
 347         jbyteArray ret_arr = (*env)->NewByteArray(env, slice->datalen);
 348         (*env)->SetByteArrayRegion(env, ret_arr, 0, slice->datalen, slice->data);
 349         return ret_arr;
 350 }
 351 JNIEXPORT int64_t impl_bindings_bytes_1to_1u8_1vec (JNIEnv * env, jclass _b, jbyteArray bytes) {
 352         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
 353         vec->datalen = (*env)->GetArrayLength(env, bytes);
 354         vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
 355         (*env)->GetByteArrayRegion (env, bytes, 0, vec->datalen, vec->data);
 356         return (uint64_t)vec;
 357 }
 358 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_txpointer_1get_1buffer (JNIEnv * env, jclass _b, jlong ptr) {
 359         LDKTransaction *txdata = (LDKTransaction*)ptr;
 360         LDKu8slice slice;
 361         slice.data = txdata->data;
 362         slice.datalen = txdata->datalen;
 363         return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (uint64_t)&slice);
 364 }
 365 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
 366         LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
 367         txdata->datalen = (*env)->GetArrayLength(env, bytes);
 368         txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
 369         txdata->data_is_owned = false;
 370         (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
 371         return (uint64_t)txdata;
 372 }
 373 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
 374         LDKTransaction *tx = (LDKTransaction*)ptr;
 375         tx->data_is_owned = true;
 376         Transaction_free(*tx);
 377         FREE((void*)ptr);
 378 }
 379 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
 380         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
 381         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
 382         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
 383         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");
 384         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_C2Tuple_usizeTransactionZZ, datalen), "Vec<*> needs to be mapped identically");
 385         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
 386         return (uint64_t)vec->datalen;
 387 }
 388 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * env, jclass _b) {
 389         // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
 390         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
 391         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
 392         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
 393         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
 394         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
 395         vec->data = NULL;
 396         vec->datalen = 0;
 397         return (uint64_t)vec;
 398 }
 399
 400 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 401 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 402 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
 403 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
 404
 405 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
 406 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
 407 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 408
 409 typedef jlongArray int64_tArray;
 410 typedef jbyteArray int8_tArray;
 411
 412 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
 413         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
 414         char* conv_buf = MALLOC(len + 1, "str conv buf");
 415         memcpy(conv_buf, chars, len);
 416         conv_buf[len] = 0;
 417         jstring ret = (*env)->NewStringUTF(env, conv_buf);
 418         FREE(conv_buf);
 419         return ret;
 420 }
 421 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
 422         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
 423         char* newchars = MALLOC(str_len + 1, "String chars");
 424         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
 425         memcpy(newchars, jchars, str_len);
 426         newchars[str_len] = 0;
 427         (*env)->ReleaseStringUTFChars(env, str, jchars);
 428         LDKStr res = {
 429                 .chars = newchars,
 430                 .len = str_len,
 431                 .chars_is_owned = true
 432         };
 433         return res;
 434 }
 435
 436 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
 437         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
 438 }
 439 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
 440         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
 441 }
 442 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
 443         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
 444 }
 445 """
 446
 447         self.hu_struct_file_prefix = """package org.ldk.structs;
 448
 449 import org.ldk.impl.bindings;
 450 import org.ldk.enums.*;
 451 import org.ldk.util.*;
 452 import java.util.Arrays;
 453
 454 """
 455         self.c_fn_ty_pfx = "JNIEXPORT "
 456         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
 457         self.file_ext = ".java"
 458         self.ptr_c_ty = "int64_t"
 459         self.ptr_native_ty = "long"
 460         self.result_c_ty = "jclass"
 461         self.ptr_arr = "jobjectArray"
 462         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
 463
 464     def construct_jenv(self):
 465         res =  "JNIEnv *env;\n"
 466         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
 467         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
 468         if self.target == Target.ANDROID:
 469             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
 470         else:
 471             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
 472         res += "} else {\n"
 473         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
 474         res += "}\n"
 475         return res
 476     def deconstruct_jenv(self):
 477         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
 478         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
 479         res += "}\n"
 480         return res
 481
 482     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
 483         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 484             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
 485         return None
 486     def create_native_arr_call(self, arr_len, ty_info):
 487         if ty_info.c_ty == "int8_tArray":
 488             return "(*env)->NewByteArray(env, " + arr_len + ")"
 489         elif ty_info.subty.c_ty.endswith("Array"):
 490             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
 491             self.c_array_class_caches.add(clz_var)
 492             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
 493         else:
 494             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
 495     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
 496         if ty_info.c_ty == "int8_tArray":
 497             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 498         else:
 499             assert False
 500     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
 501         if ty_info.c_ty == "int8_tArray":
 502             if copy:
 503                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
 504             else:
 505                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
 506         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
 507             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
 508         else:
 509             return None
 510     def get_native_arr_elem(self, arr_name, idxc, ty_info):
 511         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
 512             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
 513         else:
 514             assert False # Only called if above is None
 515     def get_native_arr_ptr_call(self, ty_info):
 516         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
 517             return None
 518         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 519     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
 520         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 521             return None
 522         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
 523     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
 524         if ty_info.c_ty == "int8_tArray":
 525             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
 526         else:
 527             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 528
 529     def str_ref_to_native_call(self, var_name, str_len):
 530         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
 531     def str_ref_to_c_call(self, var_name):
 532         return "java_to_owned_str(env, " + var_name + ")"
 533
 534     def c_fn_name_define_pfx(self, fn_name, has_args):
 535         if has_args:
 536             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
 537         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
 538
 539     def init_str(self):
 540         res = ""
 541         for ty in sorted(self.c_array_class_caches):
 542             res = res + "static jclass " + ty + "_clz = NULL;\n"
 543         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
 544         for ty in sorted(self.c_array_class_caches):
 545             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
 546             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
 547             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
 548         res = res + "}\n"
 549         return res
 550
 551     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
 552         out_java_enum = "package org.ldk.enums;\n\n"
 553         out_java = ""
 554         out_c = ""
 555         out_c = out_c + "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
 556         out_c = out_c + "\tswitch ((*env)->CallIntMethod(env, clz, ordinal_meth)) {\n"
 557
 558         if enum_doc_comment is not None:
 559             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 560         out_java_enum += "public enum " + struct_name + " {\n"
 561         ord_v = 0
 562         for var in variants:
 563             out_java_enum = out_java_enum + "\t" + var + ",\n"
 564             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
 565             ord_v = ord_v + 1
 566         out_java_enum = out_java_enum + "\t; static native void init();\n"
 567         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
 568         out_java_enum = out_java_enum + "}"
 569         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
 570         out_c = out_c + "\t}\n"
 571         out_c = out_c + "\tabort();\n"
 572         out_c = out_c + "}\n"
 573
 574         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
 575         for var in variants:
 576             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
 577         out_c = out_c + self.c_fn_ty_pfx + "void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (" + self.c_fn_args_pfx + ") {\n"
 578         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
 579         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
 580         for var in variants:
 581             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
 582             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
 583         out_c = out_c + "}\n"
 584         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
 585         out_c = out_c + "\tswitch (val) {\n"
 586         ord_v = 0
 587         for var in variants:
 588             out_c = out_c + "\t\tcase " + var + ":\n"
 589             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
 590             ord_v = ord_v + 1
 591         out_c = out_c + "\t\tdefault: abort();\n"
 592         out_c = out_c + "\t}\n"
 593         out_c = out_c + "}\n\n"
 594
 595         return (out_c, out_java_enum, out_java)
 596
 597     def c_unitary_enum_to_native_call(self, ty_info):
 598         return (ty_info.rust_obj + "_to_java(env, ", ")")
 599     def native_unitary_enum_to_c_call(self, ty_info):
 600         return (ty_info.rust_obj + "_from_java(env, ", ")")
 601
 602     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
 603         out_c = ""
 604         for var in variants:
 605             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
 606             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
 607         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"
 608         for var_name in variants:
 609             out_c = out_c + "\t" + struct_name + "_" + var_name + "_class =\n"
 610             if self.target == Target.ANDROID:
 611                 out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
 612             else:
 613                 out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n"
 614             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
 615             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"
 616             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
 617         out_c = out_c + "}\n"
 618         return out_c
 619
 620     def c_complex_enum_pass_ty(self, struct_name):
 621         return "jobject"
 622
 623     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
 624         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
 625         for param in c_params:
 626             ret = ret + ", " + param
 627         return ret + ")"
 628
 629     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
 630         out_java_trait = ""
 631         out_java = ""
 632
 633         # First generate most of the Java code, note that we need information about java method argument strings for C
 634         out_java_trait = out_java_trait + self.hu_struct_file_prefix
 635         if trait_doc_comment is not None:
 636             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
 637         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 638         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
 639         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
 640         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
 641         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
 642         for var in flattened_field_vars:
 643             if isinstance(var, ConvInfo):
 644                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
 645             else:
 646                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
 647         out_java_trait = out_java_trait + ") {\n"
 648         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
 649         for var in flattened_field_vars:
 650             if isinstance(var, ConvInfo):
 651                 if var.from_hu_conv is not None:
 652                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
 653                 else:
 654                     out_java_trait = out_java_trait + ", " + var.arg_name
 655             else:
 656                 out_java_trait = out_java_trait + ", " + var[1]
 657         out_java_trait = out_java_trait + "));\n"
 658         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
 659         for var in flattened_field_vars:
 660             if isinstance(var, ConvInfo):
 661                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
 662                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
 663             else:
 664                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
 665         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
 666         out_java_trait = out_java_trait + "\t}\n"
 667         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
 668         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
 669         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
 670         out_java_trait = out_java_trait + "\t}\n\n"
 671
 672         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
 673         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
 674         for var in flattened_field_vars:
 675             if isinstance(var, ConvInfo):
 676                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
 677             else:
 678                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
 679                 # Java-implemented version, so we require users pass a Java implementation here :/
 680                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
 681         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
 682         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
 683         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
 684         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
 685         java_meths = []
 686         for fn_line in field_fns:
 687             java_meth_descr = "("
 688             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
 689                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 690                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 691                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
 692                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 693
 694                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
 695                     if idx >= 1:
 696                         out_java = out_java + ", "
 697                         java_trait_constr = java_trait_constr + ", "
 698                         out_java_trait = out_java_trait + ", "
 699                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 700                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
 701                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 702                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
 703                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
 704                 java_meths.append((fn_line.fn_name, java_meth_descr))
 705
 706                 out_java = out_java + ");\n"
 707                 out_java_trait = out_java_trait + ");\n"
 708                 java_trait_constr = java_trait_constr + ") {\n"
 709
 710                 for arg_info in fn_line.args_ty:
 711                     if arg_info.to_hu_conv is not None:
 712                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
 713
 714                 if fn_line.ret_ty_info.java_ty != "void":
 715                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
 716                 else:
 717                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
 718
 719                 for idx, arg_info in enumerate(fn_line.args_ty):
 720                     if idx != 0:
 721                         java_trait_constr = java_trait_constr + ", "
 722                     if arg_info.to_hu_conv_name is not None:
 723                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
 724                     else:
 725                         java_trait_constr = java_trait_constr + arg_info.arg_name
 726
 727                 java_trait_constr = java_trait_constr + ");\n"
 728                 if fn_line.ret_ty_info.java_ty != "void":
 729                     if fn_line.ret_ty_info.from_hu_conv is not None:
 730                         java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_ty + " result = " + fn_line.ret_ty_info.from_hu_conv[0] + ";\n"
 731                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
 732                             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"
 733                         #if fn_line.ret_ty_info.rust_obj in result_types:
 734                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
 735                     else:
 736                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
 737                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
 738         java_trait_constr = java_trait_constr + "\t\t}"
 739         for var in field_vars:
 740             if isinstance(var, ConvInfo):
 741                 java_trait_constr = java_trait_constr + ", " + var.arg_name
 742             else:
 743                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
 744                 for suparg in var[2]:
 745                     if isinstance(suparg, ConvInfo):
 746                         java_trait_constr += ", " + suparg.arg_name
 747                     else:
 748                         java_trait_constr += ", " + suparg[1]
 749                 java_trait_constr += ").bindings_instance"
 750                 for suparg in var[2]:
 751                     if isinstance(suparg, ConvInfo):
 752                         java_trait_constr += ", " + suparg.arg_name
 753                     else:
 754                         java_trait_constr += ", " + suparg[1]
 755         out_java_trait = out_java_trait + "\t}\n"
 756         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 757
 758         out_java = out_java + "\t}\n"
 759
 760         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
 761         for var in flattened_field_vars:
 762             if isinstance(var, ConvInfo):
 763                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
 764             else:
 765                 out_java = out_java + ", " + var[0] + " " + var[1]
 766         out_java = out_java + ");\n"
 767
 768         # Now that we've written out our java code (and created java_meths), generate C
 769         out_c = "typedef struct " + struct_name + "_JCalls {\n"
 770         out_c = out_c + "\tatomic_size_t refcnt;\n"
 771         out_c = out_c + "\tJavaVM *vm;\n"
 772         out_c = out_c + "\tjweak o;\n"
 773         for var in flattened_field_vars:
 774             if isinstance(var, ConvInfo):
 775                 # We're a regular ol' field
 776                 pass
 777             else:
 778                 # We're a supertrait
 779                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
 780         for fn in field_fns:
 781             if fn.fn_name != "free" and fn.fn_name != "clone":
 782                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
 783         out_c = out_c + "} " + struct_name + "_JCalls;\n"
 784
 785         for fn_line in field_fns:
 786             if fn_line.fn_name == "free":
 787                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
 788                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 789                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
 790                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 791                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
 792                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 793                 out_c = out_c + "\t\tFREE(j_calls);\n"
 794                 out_c = out_c + "\t}\n}\n"
 795
 796         for idx, fn_line in enumerate(field_fns):
 797             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
 798                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
 799                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
 800                 if fn_line.self_is_const:
 801                     out_c = out_c + "const void* this_arg"
 802                 else:
 803                     out_c = out_c + "void* this_arg"
 804
 805                 for idx, arg in enumerate(fn_line.args_ty):
 806                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
 807
 808                 out_c = out_c + ") {\n"
 809                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 810                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 811
 812                 for arg_info in fn_line.args_ty:
 813                     if arg_info.ret_conv is not None:
 814                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
 815                         out_c = out_c + arg_info.arg_name
 816                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
 817
 818                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
 819                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
 820                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 821                 elif fn_line.ret_ty_info.c_ty == "void":
 822                     out_c += "\t(*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 823                 elif not fn_line.ret_ty_info.passed_as_ptr:
 824                     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"
 825                 else:
 826                     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"
 827
 828                 for idx, arg_info in enumerate(fn_line.args_ty):
 829                     if arg_info.ret_conv is not None:
 830                         out_c = out_c + ", " + arg_info.ret_conv_name
 831                     else:
 832                         out_c = out_c + ", " + arg_info.arg_name
 833                 out_c = out_c + ");\n"
 834                 if fn_line.ret_ty_info.arg_conv is not None:
 835                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
 836                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 837                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
 838                 else:
 839                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 840                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
 841                         out_c += "\treturn ret;\n"
 842
 843                 out_c = out_c + "}\n"
 844
 845         # Write out a clone function whether we need one or not, as we use them in moving to rust
 846         out_c = out_c + "static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n"
 847         out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 848         out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
 849         for var in field_vars:
 850             if not isinstance(var, ConvInfo):
 851                 out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
 852         out_c = out_c + "\treturn (void*) this_arg;\n"
 853         out_c = out_c + "}\n"
 854
 855         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
 856         for var in flattened_field_vars:
 857             if isinstance(var, ConvInfo):
 858                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
 859             else:
 860                 out_c = out_c + ", jobject " + var[1]
 861         out_c = out_c + ") {\n"
 862
 863         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
 864         out_c = out_c + "\tCHECK(c != NULL);\n"
 865         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
 866         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
 867         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
 868         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
 869
 870         for (fn_name, java_meth_descr) in java_meths:
 871             if fn_name != "free" and fn_name != "clone":
 872                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
 873                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
 874
 875         for var in flattened_field_vars:
 876             if isinstance(var, ConvInfo) and var.arg_conv is not None:
 877                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
 878         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
 879         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
 880         for fn_line in field_fns:
 881             if fn_line.fn_name != "free" and fn_line.fn_name != "clone":
 882                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
 883             elif fn_line.fn_name == "free":
 884                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
 885             else:
 886                 out_c = out_c + "\t\t.clone = " + struct_name + "_JCalls_clone,\n"
 887         for var in field_vars:
 888             if isinstance(var, ConvInfo):
 889                 if var.arg_conv_name is not None:
 890                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
 891                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
 892                 else:
 893                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
 894                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
 895             else:
 896                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
 897                 for suparg in var[2]:
 898                     if isinstance(suparg, ConvInfo):
 899                         out_c = out_c + ", " + suparg.arg_name
 900                     else:
 901                         out_c = out_c + ", " + suparg[1]
 902                 out_c += "),\n"
 903         out_c = out_c + "\t};\n"
 904         for var in flattened_field_vars:
 905             if not isinstance(var, ConvInfo):
 906                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
 907         out_c = out_c + "\treturn ret;\n"
 908         out_c = out_c + "}\n"
 909
 910         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
 911         for var in flattened_field_vars:
 912             if isinstance(var, ConvInfo):
 913                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
 914             else:
 915                 out_c = out_c + ", jobject " + var[1]
 916         out_c = out_c + ") {\n"
 917         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
 918         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
 919         for var in flattened_field_vars:
 920             if isinstance(var, ConvInfo):
 921                 out_c = out_c + ", " + var.arg_name
 922             else:
 923                 out_c = out_c + ", " + var[1]
 924         out_c = out_c + ");\n"
 925         out_c = out_c + "\treturn (uint64_t)res_ptr;\n"
 926         out_c = out_c + "}\n"
 927
 928         return (out_java, out_java_trait, out_c)
 929
 930     def trait_struct_inc_refcnt(self, ty_info):
 931         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
 932         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
 933         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_arg);\n}"
 934         return base_conv
 935
 936     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
 937         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
 938         out_java_enum = ""
 939         out_java = ""
 940         out_c = ""
 941
 942         out_java_enum += (self.hu_struct_file_prefix)
 943         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 944         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 945         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
 946         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
 947         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
 948         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
 949         out_java_enum += ("\t\tsuper.finalize();\n")
 950         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
 951         out_java_enum += ("\t}\n")
 952         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
 953         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
 954         java_hu_subclasses = ""
 955
 956         init_meth_jty_strs = {}
 957
 958         out_java +=  ("\tpublic static class " + struct_name + " {\n")
 959         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
 960         for var in variant_list:
 961             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
 962             java_hu_subclasses = java_hu_subclasses + "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
 963             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
 964             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
 965             init_meth_jty_str = ""
 966             init_meth_params = ""
 967             init_meth_body = ""
 968             hu_conv_body = ""
 969             for idx, field_ty in enumerate(var.fields):
 970                 if idx > 0:
 971                     init_meth_params = init_meth_params + ", "
 972
 973                 if field_ty.java_hu_ty == var.var_name:
 974                     field_path = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
 975                     out_java += "\t\t\tpublic " + field_path + " " + field_ty.arg_name + ";\n"
 976                     java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_path + " " + field_ty.arg_name + ";\n"
 977                     init_meth_params = init_meth_params + field_path + " " + field_ty.arg_name
 978                 else:
 979                     out_java += "\t\t\tpublic " + field_ty.java_ty + " " + field_ty.arg_name + ";\n"
 980                     java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_ty.java_hu_ty + " " + field_ty.arg_name + ";\n"
 981                     init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.arg_name
 982                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
 983                 if field_ty.to_hu_conv is not None:
 984                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
 985                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
 986                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
 987                 else:
 988                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
 989                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
 990             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
 991             out_java +=  (init_meth_body)
 992             out_java +=  ("}\n")
 993             out_java += ("\t\t}\n")
 994             out_java_enum += ("\t\t}\n")
 995             java_hu_subclasses = java_hu_subclasses + "\t\tprivate " + var.var_name + "(long ptr, bindings." + struct_name + "." + var.var_name + " obj) {\n\t\t\tsuper(null, ptr);\n"
 996             java_hu_subclasses = java_hu_subclasses + hu_conv_body
 997             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
 998             init_meth_jty_strs[var.var_name] = init_meth_jty_str
 999         out_java += ("\t\tstatic native void init();\n")
1000         out_java += ("\t}\n")
1001         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1002         out_java_enum += (java_hu_subclasses)
1003         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1004         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1005
1006         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1007
1008         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")
1009         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)(ptr & ~1);\n")
1010         out_c += ("\tswitch(obj->tag) {\n")
1011         for var in variant_list:
1012             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1013             c_params = []
1014             for idx, field_map in enumerate(var.fields):
1015                 if field_map.ret_conv is not None:
1016                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1017                     if var.tuple_variant:
1018                         out_c += "obj->" + camel_to_snake(var.var_name)
1019                     else:
1020                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1021                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1022                     c_params.append(field_map.ret_conv_name)
1023                 else:
1024                     if var.tuple_variant:
1025                         c_params.append("obj->" + camel_to_snake(var.var_name))
1026                     else:
1027                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1028             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1029             out_c += ("\t\t}\n")
1030         out_c += ("\t\tdefault: abort();\n")
1031         out_c += ("\t}\n}\n")
1032         return (out_java, out_java_enum, out_c)
1033
1034     def map_opaque_struct(self, struct_name, struct_doc_comment):
1035         out_opaque_struct_human = ""
1036         out_opaque_struct_human += self.hu_struct_file_prefix
1037         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1038         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1039         out_opaque_struct_human += ("public class " + struct_name.replace("LDK","") + " extends CommonBase")
1040         if struct_name.startswith("LDKLocked"):
1041             out_opaque_struct_human += (" implements AutoCloseable")
1042         out_opaque_struct_human += (" {\n")
1043         out_opaque_struct_human += ("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
1044         if struct_name.startswith("LDKLocked"):
1045             out_opaque_struct_human += ("\t@Override public void close() {\n")
1046         else:
1047             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1048             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1049             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1050         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1051         out_opaque_struct_human += ("\t}\n\n")
1052         return out_opaque_struct_human
1053
1054
1055     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):
1056         out_java = ""
1057         out_c = ""
1058         out_java_struct = None
1059
1060         out_java += ("\tpublic static native ")
1061         out_c += (self.c_fn_ty_pfx)
1062         out_c += (return_type_info.c_ty)
1063         out_java += (return_type_info.java_ty)
1064         if return_type_info.ret_conv is not None:
1065             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1066         out_java += (" " + method_name + "(")
1067         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1068         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1069
1070         for idx, arg_conv_info in enumerate(argument_types):
1071             if idx != 0:
1072                 out_java += (", ")
1073                 out_c += (", ")
1074             if arg_conv_info.c_ty != "void":
1075                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1076                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1077
1078         out_java_struct = ""
1079         if not args_known:
1080             out_java_struct += ("\t// Skipped " + method_name + "\n")
1081         else:
1082             meth_n = method_name[len(struct_meth) + 1 if len(struct_meth) != 0 else 0:].strip("_")
1083             if doc_comment is not None:
1084                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1085             if not takes_self:
1086                 if meth_n == "new":
1087                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1088                 elif meth_n == "default":
1089                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1090                 else:
1091                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1092             else:
1093                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1094             for idx, arg in enumerate(argument_types):
1095                 if idx != 0:
1096                     if not takes_self or idx > 1:
1097                         out_java_struct += ", "
1098                 elif takes_self:
1099                     continue
1100                 if arg.java_ty != "void":
1101                     if arg.arg_name in default_constructor_args:
1102                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1103                             if explode_idx != 0:
1104                                 out_java_struct += (", ")
1105                             out_java_struct += (
1106                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1107                     else:
1108                         out_java_struct += (arg.java_hu_ty + " " + arg.arg_name)
1109         out_java += (");\n")
1110         out_c += (") {\n")
1111         if out_java_struct is not None:
1112             out_java_struct += (") {\n")
1113         for info in argument_types:
1114             if info.arg_conv is not None:
1115                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1116         if return_type_info.ret_conv is not None:
1117             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1118         elif return_type_info.c_ty != "void":
1119             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1120         else:
1121             out_c += ("\t")
1122         if c_call_string is None:
1123             out_c += (method_name + "(")
1124         else:
1125             out_c += (c_call_string)
1126         for idx, info in enumerate(argument_types):
1127             if info.arg_conv_name is not None:
1128                 if idx != 0:
1129                     out_c += (", ")
1130                 elif c_call_string is not None:
1131                     continue
1132                 out_c += (info.arg_conv_name)
1133         out_c += (")")
1134         if return_type_info.ret_conv is not None:
1135             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1136         else:
1137             out_c += (";")
1138         for info in argument_types:
1139             if info.arg_conv_cleanup is not None:
1140                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1141         if return_type_info.ret_conv is not None:
1142             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1143         elif return_type_info.c_ty != "void":
1144             out_c += ("\n\treturn ret_val;")
1145         out_c += ("\n}\n\n")
1146
1147         if args_known:
1148             out_java_struct += ("\t\t")
1149             if return_type_info.java_ty != "void":
1150                 out_java_struct += (return_type_info.java_ty + " ret = ")
1151             out_java_struct += ("bindings." + method_name + "(")
1152             for idx, info in enumerate(argument_types):
1153                 if idx != 0:
1154                     out_java_struct += (", ")
1155                 if idx == 0 and takes_self:
1156                     out_java_struct += ("this.ptr")
1157                 elif info.arg_name in default_constructor_args:
1158                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1159                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1160                         if explode_idx != 0:
1161                             out_java_struct += (", ")
1162                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1163                         if explode_arg.from_hu_conv is not None:
1164                             out_java_struct += (
1165                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1166                         else:
1167                             out_java_struct += (expl_arg_name)
1168                     out_java_struct += (")")
1169                 elif info.from_hu_conv is not None:
1170                     out_java_struct += (info.from_hu_conv[0])
1171                 else:
1172                     out_java_struct += (info.arg_name)
1173             out_java_struct += (");\n")
1174             if return_type_info.to_hu_conv is not None:
1175                 if not takes_self:
1176                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1177                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1178                 else:
1179                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1180
1181             for idx, info in enumerate(argument_types):
1182                 if idx == 0 and takes_self:
1183                     pass
1184                 elif info.arg_name in default_constructor_args:
1185                     for explode_arg in default_constructor_args[info.arg_name]:
1186                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1187                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1188                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1189                                                                                                expl_arg_name).replace(
1190                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1191                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1192                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1193                         out_java_struct += (
1194                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1195                     else:
1196                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1197
1198             if takes_self and not takes_self_as_ref:
1199                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1200             if return_type_info.to_hu_conv_name is not None:
1201                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1202             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1203                 out_java_struct += ("\t\treturn ret;\n")
1204             out_java_struct += ("\t}\n\n")
1205
1206         return (out_java, out_c, out_java_struct)