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

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