_ 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             bool = ['boolean'],
  15             uint8_t = ['byte'],
  16             uint16_t = ['short'],
  17             uint32_t = ['int'],
  18             uint64_t = ['long'],
  19         )
  20         self.java_type_map = dict(
  21             String = "String"
  22         )
  23         self.java_hu_type_map = dict(
  24             String = "String"
  25         )
  26
  27         self.to_hu_conv_templates = dict(
  28             ptr = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }',
  29             default = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }'
  30         )
  31
  32         self.bindings_header = """package org.ldk.impl;
  33 import org.ldk.enums.*;
  34 import org.ldk.impl.version;
  35 import java.io.File;
  36 import java.io.InputStream;
  37 import java.io.IOException;
  38 import java.nio.file.Files;
  39 import java.nio.file.Path;
  40 import java.nio.file.StandardCopyOption;
  41
  42 public class bindings {
  43         static {
  44                 try {
  45                         // Try to load natively first, this works on Android and in testing.
  46                         System.loadLibrary(\"lightningjni\");
  47                 } catch (UnsatisfiedLinkError system_load_err) {
  48                         // Otherwise try to load from the library jar.
  49                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
  50                         tmpdir.mkdir(); // If it fails to create, assume it was there already
  51                         tmpdir.deleteOnExit();
  52                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
  53                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
  54                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
  55                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
  56                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
  57                                 Runtime.getRuntime().load(libpath.toString());
  58                         } catch (Exception e) {
  59                                 System.err.println("Failed to load LDK native library.");
  60                                 System.err.println("System LDK native library load failed with: " + system_load_err);
  61                                 System.err.println("Resource-based LDK native library load failed with: " + e);
  62                                 throw new IllegalArgumentException(e);
  63                         }
  64                 }
  65                 init(java.lang.Enum.class);
  66                 init_class_cache();
  67                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
  68                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
  69                 // Fetching the LDK versions from C also checks that the header and binaries match
  70                 System.err.println("Loaded LDK-Java Bindings " + version.get_ldk_java_bindings_version() + " with LDK " + get_ldk_version() + " and LDK-C-Bindings " + get_ldk_c_bindings_version());
  71         }
  72         static native void init(java.lang.Class c);
  73         static native void init_class_cache();
  74         static native String get_lib_version_string();
  75
  76         public static native String get_ldk_c_bindings_version();
  77         public static native String get_ldk_version();
  78
  79 """
  80         self.bindings_version_file = """package org.ldk.impl;
  81
  82 public class version {
  83         public static String get_ldk_java_bindings_version() {
  84                 return "<git_version_ldk_garbagecollected>";
  85         }
  86 }"""
  87
  88         self.util_fn_pfx = """package org.ldk.structs;
  89 import org.ldk.impl.bindings;
  90 import org.ldk.enums.*;
  91 import org.ldk.util.*;
  92 import java.util.Arrays;
  93 import java.lang.ref.Reference;
  94 import javax.annotation.Nullable;
  95
  96 public class UtilMethods {
  97 """
  98         self.util_fn_sfx = "}"
  99         self.common_base = """package org.ldk.structs;
 100 import java.util.LinkedList;
 101 class CommonBase {
 102         long ptr;
 103         LinkedList<Object> ptrs_to = new LinkedList();
 104         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
 105 }
 106 """
 107
 108         self.txout_defn = """public class TxOut extends CommonBase {
 109         /** The script_pubkey in this output */
 110         public final byte[] script_pubkey;
 111         /** The value, in satoshis, of this output */
 112         public final long value;
 113
 114         TxOut(java.lang.Object _dummy, long ptr) {
 115                 super(ptr);
 116                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 117                 this.value = bindings.TxOut_get_value(ptr);
 118         }
 119         public TxOut(long value, byte[] script_pubkey) {
 120                 super(bindings.TxOut_new(script_pubkey, value));
 121                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 122                 this.value = bindings.TxOut_get_value(ptr);
 123         }
 124
 125         @Override @SuppressWarnings(\"deprecation\")
 126         protected void finalize() throws Throwable {
 127                 super.finalize();
 128                 if (ptr != 0) { bindings.TxOut_free(ptr); }
 129         }
 130 }"""
 131
 132         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
 133         /** The bytes of the scalar value, in big endian */
 134         public final byte[] scalar_bytes;
 135
 136         BigEndianScalar(java.lang.Object _dummy, long ptr) {
 137                 super(ptr);
 138                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 139         }
 140         public BigEndianScalar(byte[] scalar_bytes) {
 141                 super(bindings.BigEndianScalar_new(scalar_bytes));
 142                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 143         }
 144
 145         @Override @SuppressWarnings(\"deprecation\")
 146         protected void finalize() throws Throwable {
 147                 super.finalize();
 148                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
 149         }
 150 }"""
 151
 152
 153         self.c_file_pfx = """#include <jni.h>
 154 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
 155 #define int64_t jlong
 156 #include \"org_ldk_impl_bindings.h\"
 157 #include <lightning.h>
 158 #include <string.h>
 159 #include <stdatomic.h>
 160 #include <stdlib.h>
 161
 162 #define LIKELY(v) __builtin_expect(!!(v), 1)
 163 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
 164
 165 """
 166
 167         if self.target == Target.ANDROID:
 168             self.c_file_pfx = self.c_file_pfx + """
 169 #include <android/log.h>
 170 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
 171
 172 #include <unistd.h>
 173 #include <pthread.h>
 174 static void* redirect_stderr(void* ignored) {
 175         int pipes[2];
 176         pipe(pipes);
 177         dup2(pipes[1], STDERR_FILENO);
 178         char buf[8192];
 179         memset(buf, 0, 8192);
 180         ssize_t len;
 181         while ((len = read(pipes[0], buf, 8191)) > 0) {
 182                 DEBUG_PRINT("%s\\n", buf);
 183                 memset(buf, 0, 8192);
 184         }
 185         DEBUG_PRINT("End of stderr???\\n");
 186         return 0;
 187 }
 188 void __attribute__((constructor)) spawn_stderr_redirection() {
 189         pthread_t thread;
 190         pthread_create(&thread, NULL, &redirect_stderr, NULL);
 191 }
 192 """
 193         else:
 194             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 195
 196         if not DEBUG or sys.platform == "darwin":
 197             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
 198 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
 199 #define CHECK_ACCESS(p)
 200 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
 201 """
 202         if not DEBUG:
 203             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
 204 #define CHECK(a)
 205 """
 206         if DEBUG:
 207             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
 208 // Always run a, then assert it is true:
 209 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 210 // Assert a is true or do nothing
 211 #define CHECK(a) DO_ASSERT(a)
 212
 213 void __attribute__((constructor)) debug_log_version() {
 214         if (check_get_ldk_version() == NULL)
 215                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
 216         if (check_get_ldk_bindings_version() == NULL)
 217                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
 218 }
 219 """
 220
 221             if sys.platform != "darwin":
 222                 self.c_file_pfx += """
 223 // Running a leak check across all the allocations and frees of the JDK is a mess,
 224 // so instead we implement our own naive leak checker here, relying on the -wrap
 225 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
 226 // and free'd in Rust or C across the generated bindings shared library.
 227 #include <threads.h>
 228 """
 229
 230                 if self.target == Target.ANDROID:
 231                     self.c_file_pfx = self.c_file_pfx + """
 232 #include <unwind.h>
 233 #include <dlfcn.h>
 234
 235 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
 236 // symbols, so we only use it on Android, where execinfo.h is unavailable.
 237
 238 struct BacktraceState {
 239         void** current;
 240         void** end;
 241 };
 242 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
 243         struct BacktraceState* state = (struct BacktraceState*)arg;
 244         uintptr_t pc = _Unwind_GetIP(context);
 245         if (pc) {
 246                 if (state->current == state->end) {
 247                         return _URC_END_OF_STACK;
 248                 } else {
 249                         *state->current++ = (void*)(pc);
 250                 }
 251         }
 252         return _URC_NO_REASON;
 253 }
 254
 255 int backtrace(void** buffer, int max) {
 256         struct BacktraceState state = { buffer, buffer + max };
 257         _Unwind_Backtrace(unwind_callback, &state);
 258         return state.current - buffer;
 259 }
 260
 261 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
 262         for (int idx = 0; idx < count; ++idx) {
 263                 Dl_info info;
 264                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
 265                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
 266                 } else {
 267                         DEBUG_PRINT("%p: ???", buffer[idx]);
 268                 }
 269         }
 270 }
 271 """
 272                 else:
 273                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
 274                 self.c_file_pfx = self.c_file_pfx + """
 275 #include <unistd.h>
 276 #include <pthread.h>
 277 static pthread_mutex_t allocation_mtx;
 278
 279 void __attribute__((constructor)) init_mtx() {
 280         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
 281 }
 282
 283 #define BT_MAX 128
 284 typedef struct allocation {
 285         struct allocation* next;
 286         void* ptr;
 287         const char* struct_name;
 288         void* bt[BT_MAX];
 289         int bt_len;
 290         unsigned long alloc_len;
 291 } allocation;
 292 static allocation* allocation_ll = NULL;
 293
 294 void* __real_malloc(size_t len);
 295 void* __real_calloc(size_t nmemb, size_t len);
 296 static void new_allocation(void* res, const char* struct_name, size_t len) {
 297         allocation* new_alloc = __real_malloc(sizeof(allocation));
 298         new_alloc->ptr = res;
 299         new_alloc->struct_name = struct_name;
 300         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
 301         new_alloc->alloc_len = len;
 302         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 303         new_alloc->next = allocation_ll;
 304         allocation_ll = new_alloc;
 305         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 306 }
 307 static void* MALLOC(size_t len, const char* struct_name) {
 308         void* res = __real_malloc(len);
 309         new_allocation(res, struct_name, len);
 310         return res;
 311 }
 312 void __real_free(void* ptr);
 313 static void alloc_freed(void* ptr) {
 314         allocation* p = NULL;
 315         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 316         allocation* it = allocation_ll;
 317         while (it->ptr != ptr) {
 318                 p = it; it = it->next;
 319                 if (it == NULL) {
 320                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
 321                         void* bt[BT_MAX];
 322                         int bt_len = backtrace(bt, BT_MAX);
 323                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 324                         DEBUG_PRINT("\\n\\n");
 325                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 326                         return; // addrsan should catch malloc-unknown and print more info than we have
 327                 }
 328         }
 329         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
 330         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 331         DO_ASSERT(it->ptr == ptr);
 332         __real_free(it);
 333 }
 334 static void FREE(void* ptr) {
 335         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
 336         alloc_freed(ptr);
 337         __real_free(ptr);
 338 }
 339
 340 void* __wrap_malloc(size_t len) {
 341         void* res = __real_malloc(len);
 342         new_allocation(res, "malloc call", len);
 343         return res;
 344 }
 345 void* __wrap_calloc(size_t nmemb, size_t len) {
 346         void* res = __real_calloc(nmemb, len);
 347         new_allocation(res, "calloc call", len);
 348         return res;
 349 }
 350 void __wrap_free(void* ptr) {
 351         if (ptr == NULL) return;
 352         alloc_freed(ptr);
 353         __real_free(ptr);
 354 }
 355
 356 static void CHECK_ACCESS(const void* ptr) {
 357         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 358         allocation* it = allocation_ll;
 359         while (it->ptr != ptr) {
 360                 it = it->next;
 361                 if (it == NULL) {
 362                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
 363                         void* bt[BT_MAX];
 364                         int bt_len = backtrace(bt, BT_MAX);
 365                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 366                         DEBUG_PRINT("\\n\\n");
 367                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 368                         return; // addrsan should catch and print more info than we have
 369                 }
 370         }
 371         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 372 }
 373 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
 374         if (v.is_owned && v.inner != NULL) { \\
 375                 const void *p = __unmangle_inner_ptr(v.inner); \\
 376                 if (p != NULL) { \\
 377                         CHECK_ACCESS(p); \\
 378                 } \\
 379         }
 380
 381 void* __real_realloc(void* ptr, size_t newlen);
 382 void* __wrap_realloc(void* ptr, size_t len) {
 383         if (ptr != NULL) alloc_freed(ptr);
 384         void* res = __real_realloc(ptr, len);
 385         new_allocation(res, "realloc call", len);
 386         return res;
 387 }
 388 void __wrap_reallocarray(void* ptr, size_t new_sz) {
 389         // Rust doesn't seem to use reallocarray currently
 390         DO_ASSERT(false);
 391 }
 392
 393 void __attribute__((destructor)) check_leaks() {
 394         unsigned long alloc_count = 0;
 395         unsigned long alloc_size = 0;
 396         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
 397         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 398         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 399         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
 400                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
 401                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
 402                 DEBUG_PRINT("\\n\\n");
 403                 alloc_count++;
 404                 alloc_size += a->alloc_len;
 405         }
 406         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
 407         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 408         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 409 }
 410 """
 411         self.c_file_pfx = self.c_file_pfx + """
 412 static jmethodID ordinal_meth = NULL;
 413 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
 414         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 415         CHECK(ordinal_meth != NULL);
 416 }
 417
 418 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 419 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 420 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
 421 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
 422
 423 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
 424 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
 425 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 426
 427 typedef jlongArray int64_tArray;
 428 typedef jbyteArray int8_tArray;
 429 typedef jshortArray int16_tArray;
 430
 431 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
 432         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
 433         char* conv_buf = MALLOC(len + 1, "str conv buf");
 434         memcpy(conv_buf, chars, len);
 435         conv_buf[len] = 0;
 436         jstring ret = (*env)->NewStringUTF(env, conv_buf);
 437         FREE(conv_buf);
 438         return ret;
 439 }
 440 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
 441         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
 442         char* newchars = MALLOC(str_len + 1, "String chars");
 443         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
 444         memcpy(newchars, jchars, str_len);
 445         newchars[str_len] = 0;
 446         (*env)->ReleaseStringUTFChars(env, str, jchars);
 447         LDKStr res = {
 448                 .chars = newchars,
 449                 .len = str_len,
 450                 .chars_is_owned = true
 451         };
 452         return res;
 453 }
 454
 455 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
 456         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
 457 }
 458 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
 459         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
 460 }
 461 #include "version.c"
 462 """
 463         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
 464         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
 465 }"""
 466
 467         self.hu_struct_file_prefix = """package org.ldk.structs;
 468
 469 import org.ldk.impl.bindings;
 470 import org.ldk.enums.*;
 471 import org.ldk.util.*;
 472 import java.util.Arrays;
 473 import java.lang.ref.Reference;
 474 import javax.annotation.Nullable;
 475
 476 """
 477         self.hu_struct_file_suffix = ""
 478         self.c_fn_ty_pfx = "JNIEXPORT "
 479         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
 480         self.file_ext = ".java"
 481         self.ptr_c_ty = "int64_t"
 482         self.ptr_native_ty = "long"
 483         self.u128_native_ty = "UInt128"
 484         self.usize_c_ty = "int64_t"
 485         self.usize_native_ty = "long"
 486         self.native_zero_ptr = "0"
 487         self.result_c_ty = "jclass"
 488         self.ptr_arr = "jobjectArray"
 489         self.is_arr_some_check = ("", " != NULL")
 490         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
 491
 492     def bindings_footer(self):
 493         return "}\n"
 494
 495     def construct_jenv(self):
 496         res =  "JNIEnv *env;\n"
 497         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
 498         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
 499         if self.target == Target.ANDROID:
 500             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
 501         else:
 502             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
 503         res += "} else {\n"
 504         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
 505         res += "}\n"
 506         return res
 507     def deconstruct_jenv(self):
 508         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
 509         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
 510         res += "}\n"
 511         return res
 512
 513     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
 514         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 515             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
 516         return None
 517     def create_native_arr_call(self, arr_len, ty_info):
 518         if ty_info.c_ty == "int8_tArray":
 519             return "(*env)->NewByteArray(env, " + arr_len + ")"
 520         elif ty_info.subty.c_ty.endswith("Array"):
 521             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
 522             self.c_array_class_caches.add(clz_var)
 523             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
 524         else:
 525             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
 526     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
 527         if ty_info.c_ty == "int8_tArray":
 528             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 529         elif ty_info.c_ty == "int16_tArray":
 530             return ("(*env)->SetShortArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 531         else:
 532             assert False
 533     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
 534         if ty_info.c_ty == "int8_tArray" or ty_info.c_ty == "int16_tArray":
 535             fn_ty = "Byte" if ty_info.c_ty == "int8_tArray" else "Short"
 536             if copy:
 537                 return "(*env)->Get" + fn_ty + "ArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
 538             else:
 539                 return "(*env)->Get" + fn_ty + "ArrayElements (env, " + arr_name + ", NULL)"
 540         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
 541             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
 542         else:
 543             return None
 544     def get_native_arr_elem(self, arr_name, idxc, ty_info):
 545         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
 546             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
 547         else:
 548             assert False # Only called if above is None
 549     def get_native_arr_ptr_call(self, ty_info):
 550         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
 551             return None
 552         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 553     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
 554         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 555             return None
 556         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
 557     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
 558         if ty_info.c_ty == "int8_tArray":
 559             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
 560         else:
 561             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 562
 563     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
 564         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
 565             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 566         elif elem_ty.java_ty == "long":
 567             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 568         elif elem_ty.java_hu_ty == "UInt5":
 569             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
 570         elif elem_ty.java_hu_ty == "WitnessVersion":
 571             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
 572         else:
 573             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
 574
 575     def str_ref_to_native_call(self, var_name, str_len):
 576         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
 577     def str_ref_to_c_call(self, var_name):
 578         return "java_to_owned_str(env, " + var_name + ")"
 579     def str_to_hu_conv(self, var_name):
 580         return None
 581     def str_from_hu_conv(self, var_name):
 582         return None
 583
 584     def c_fn_name_define_pfx(self, fn_name, has_args):
 585         if has_args:
 586             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
 587         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
 588
 589     def init_str(self):
 590         res = ""
 591         for ty in sorted(self.c_array_class_caches):
 592             res = res + "static jclass " + ty + "_clz = NULL;\n"
 593         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
 594         for ty in sorted(self.c_array_class_caches):
 595             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
 596             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
 597             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
 598         res = res + "}\n"
 599         return res
 600
 601     def var_decl_statement(self, ty_string, var_name, statement):
 602         return ty_string + " " + var_name + " = " + statement
 603
 604     def get_java_arr_len(self, arr_name):
 605         return arr_name + ".length"
 606     def get_java_arr_elem(self, elem_ty, arr_name, idx):
 607         return arr_name + "[" + idx + "]"
 608     def constr_hu_array(self, ty_info, arr_len):
 609         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
 610         conv = "new " + base_ty + "[" + arr_len + "]"
 611         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
 612             # Do a bit of a dance to move any excess [] to the end
 613             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
 614         return conv
 615     def cleanup_converted_native_array(self, ty_info, arr_name):
 616         return None
 617
 618     def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
 619         mapped_ty = arr_ty.subty
 620         if arr_ty.rust_obj == "LDKU128":
 621             return ("" + arr_name + ".getLEBytes()", "")
 622         if fixed_len is not None:
 623             if mapped_ty.c_ty == "int8_t" or mapped_ty.c_ty == "uint8_t":
 624                 return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
 625             elif mapped_ty.c_ty == "int16_t" or mapped_ty.c_ty == "uint16_t":
 626                 return ("InternalUtils.check_arr_16_len(" + arr_name + ", " + fixed_len + ")", "")
 627             else:
 628                 print(arr_ty.c_ty)
 629                 assert False
 630         return None
 631     def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
 632         if arr_ty.rust_obj == "LDKU128":
 633             return "org.ldk.util.UInt128 " + conv_name + " = new org.ldk.util.UInt128(" + arr_name + ");"
 634         return None
 635
 636     def java_arr_ty_str(self, elem_ty_str):
 637         return elem_ty_str + "[]"
 638
 639     def for_n_in_range(self, n, minimum, maximum):
 640         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
 641     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
 642         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
 643
 644     def get_ptr(self, var):
 645         return var + ".ptr"
 646     def set_null_skip_free(self, var):
 647         return var + ".ptr" + " = 0;"
 648
 649     def add_ref(self, holder, referent):
 650         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
 651
 652     def fully_qualified_hu_ty_path(self, ty):
 653         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
 654             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
 655         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt128" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
 656             return "org.ldk.util." + ty.java_hu_ty
 657         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
 658             return "org.ldk.structs." + ty.java_hu_ty
 659         return ty.java_hu_ty
 660
 661     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
 662         out_java_enum = "package org.ldk.enums;\n\n"
 663         out_java = ""
 664         out_c = ""
 665         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
 666         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
 667         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 668         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 669         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
 670         out_c += "\t}\n"
 671         out_c += "\tswitch (ord) {\n"
 672
 673         if enum_doc_comment is not None:
 674             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 675         out_java_enum += "public enum " + struct_name + " {\n"
 676         ord_v = 0
 677         for var, var_docs in variants:
 678             if var_docs is not None:
 679                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
 680             out_java_enum += "\t" + var + ",\n"
 681             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
 682             ord_v = ord_v + 1
 683         out_java_enum = out_java_enum + "\t; static native void init();\n"
 684         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
 685         out_java_enum = out_java_enum + "}"
 686         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
 687         out_c += "\t}\n"
 688         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
 689         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
 690         out_c += "}\n"
 691
 692         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
 693         for var, _ in variants:
 694             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
 695         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"
 696         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
 697         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
 698         for var, _ in variants:
 699             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
 700             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
 701         out_c = out_c + "}\n"
 702         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
 703         out_c = out_c + "\tswitch (val) {\n"
 704         ord_v = 0
 705         for var, _ in variants:
 706             out_c = out_c + "\t\tcase " + var + ":\n"
 707             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
 708             ord_v = ord_v + 1
 709         out_c = out_c + "\t\tdefault: abort();\n"
 710         out_c = out_c + "\t}\n"
 711         out_c = out_c + "}\n\n"
 712
 713         return (out_c, out_java_enum, out_java)
 714
 715     def c_unitary_enum_to_native_call(self, ty_info):
 716         return (ty_info.rust_obj + "_to_java(env, ", ")")
 717     def native_unitary_enum_to_c_call(self, ty_info):
 718         return (ty_info.rust_obj + "_from_java(env, ", ")")
 719
 720     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
 721         out_c = ""
 722         for var in variants:
 723             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
 724             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
 725         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"
 726         for var_name in variants:
 727             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
 728             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
 729             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
 730             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"
 731             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
 732         out_c = out_c + "}\n"
 733         return out_c
 734
 735     def c_complex_enum_pass_ty(self, struct_name):
 736         return "jobject"
 737
 738     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
 739         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
 740         for param in c_params:
 741             ret = ret + ", " + param
 742         return ret + ")"
 743
 744     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
 745         out_java_trait = ""
 746         out_java = ""
 747
 748         # First generate most of the Java code, note that we need information about java method argument strings for C
 749         out_java_trait = out_java_trait + self.hu_struct_file_prefix
 750         if trait_doc_comment is not None:
 751             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
 752         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 753         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
 754         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
 755         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
 756         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
 757         for var in flattened_field_vars:
 758             if isinstance(var, ConvInfo):
 759                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
 760             else:
 761                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
 762         out_java_trait = out_java_trait + ") {\n"
 763         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
 764         for var in flattened_field_vars:
 765             if isinstance(var, ConvInfo):
 766                 if var.from_hu_conv is not None:
 767                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
 768                 else:
 769                     out_java_trait = out_java_trait + ", " + var.arg_name
 770             else:
 771                 out_java_trait = out_java_trait + ", " + var[1]
 772         out_java_trait = out_java_trait + "));\n"
 773         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
 774         for var in flattened_field_vars:
 775             if isinstance(var, ConvInfo):
 776                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
 777                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
 778             else:
 779                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
 780         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
 781         out_java_trait = out_java_trait + "\t}\n"
 782         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
 783         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
 784         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
 785         out_java_trait = out_java_trait + "\t}\n\n"
 786
 787         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
 788         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
 789         for var in flattened_field_vars:
 790             if isinstance(var, ConvInfo):
 791                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
 792             else:
 793                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
 794                 # Java-implemented version, so we require users pass a Java implementation here :/
 795                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
 796         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
 797         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
 798         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
 799         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
 800         java_meths = []
 801         for fn_line in field_fns:
 802             java_meth_descr = "("
 803             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 804                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 805                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 806                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
 807                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 808
 809                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
 810                     if idx >= 1:
 811                         out_java = out_java + ", "
 812                         java_trait_constr = java_trait_constr + ", "
 813                         out_java_trait = out_java_trait + ", "
 814                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 815                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
 816                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 817                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
 818                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
 819                 java_meths.append((fn_line.fn_name, java_meth_descr))
 820
 821                 out_java = out_java + ");\n"
 822                 out_java_trait = out_java_trait + ");\n"
 823                 java_trait_constr = java_trait_constr + ") {\n"
 824
 825                 for arg_info in fn_line.args_ty:
 826                     if arg_info.to_hu_conv is not None:
 827                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
 828
 829                 if fn_line.ret_ty_info.java_ty != "void":
 830                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
 831                 else:
 832                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
 833
 834                 for idx, arg_info in enumerate(fn_line.args_ty):
 835                     if idx != 0:
 836                         java_trait_constr = java_trait_constr + ", "
 837                     if arg_info.to_hu_conv_name is not None:
 838                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
 839                     else:
 840                         java_trait_constr = java_trait_constr + arg_info.arg_name
 841
 842                 java_trait_constr += ");\n"
 843                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
 844                 if fn_line.ret_ty_info.java_ty != "void":
 845                     if fn_line.ret_ty_info.from_hu_conv is not None:
 846                         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"
 847                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
 848                             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"
 849                         #if fn_line.ret_ty_info.rust_obj in result_types:
 850                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
 851                     else:
 852                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
 853                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
 854         java_trait_constr = java_trait_constr + "\t\t}"
 855         for var in field_vars:
 856             if isinstance(var, ConvInfo):
 857                 java_trait_constr = java_trait_constr + ", " + var.arg_name
 858             else:
 859                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
 860                 for suparg in var[2]:
 861                     if isinstance(suparg, ConvInfo):
 862                         java_trait_constr += ", " + suparg.arg_name
 863                     else:
 864                         java_trait_constr += ", " + suparg[1]
 865                 java_trait_constr += ").bindings_instance"
 866                 for suparg in var[2]:
 867                     if isinstance(suparg, ConvInfo):
 868                         java_trait_constr += ", " + suparg.arg_name
 869                     else:
 870                         java_trait_constr += ", " + suparg[1]
 871         out_java_trait = out_java_trait + "\t}\n"
 872         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 873
 874         out_java = out_java + "\t}\n"
 875
 876         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
 877         for var in flattened_field_vars:
 878             if isinstance(var, ConvInfo):
 879                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
 880             else:
 881                 out_java = out_java + ", " + var[0] + " " + var[1]
 882         out_java = out_java + ");\n"
 883
 884         # Now that we've written out our java code (and created java_meths), generate C
 885         out_c = "typedef struct " + struct_name + "_JCalls {\n"
 886         out_c = out_c + "\tatomic_size_t refcnt;\n"
 887         out_c = out_c + "\tJavaVM *vm;\n"
 888         out_c = out_c + "\tjweak o;\n"
 889         for var in flattened_field_vars:
 890             if isinstance(var, ConvInfo):
 891                 # We're a regular ol' field
 892                 pass
 893             else:
 894                 # We're a supertrait
 895                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
 896         for fn in field_fns:
 897             if fn.fn_name != "free" and fn.fn_name != "cloned":
 898                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
 899         out_c = out_c + "} " + struct_name + "_JCalls;\n"
 900
 901         for fn_line in field_fns:
 902             if fn_line.fn_name == "free":
 903                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
 904                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 905                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
 906                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 907                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
 908                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 909                 out_c = out_c + "\t\tFREE(j_calls);\n"
 910                 out_c = out_c + "\t}\n}\n"
 911
 912         for idx, fn_line in enumerate(field_fns):
 913             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 914                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
 915                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
 916                 if fn_line.self_is_const:
 917                     out_c = out_c + "const void* this_arg"
 918                 else:
 919                     out_c = out_c + "void* this_arg"
 920
 921                 for idx, arg in enumerate(fn_line.args_ty):
 922                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
 923
 924                 out_c = out_c + ") {\n"
 925                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 926                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 927
 928                 for arg_info in fn_line.args_ty:
 929                     if arg_info.ret_conv is not None:
 930                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
 931                         out_c = out_c + arg_info.arg_name
 932                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
 933
 934                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
 935                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
 936                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 937                 elif fn_line.ret_ty_info.c_ty == "void":
 938                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 939                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
 940                     # Manually write out String methods as they're just an Object
 941                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 942                 elif not fn_line.ret_ty_info.passed_as_ptr:
 943                     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"
 944                 else:
 945                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 946
 947                 for idx, arg_info in enumerate(fn_line.args_ty):
 948                     if arg_info.ret_conv is not None:
 949                         out_c = out_c + ", " + arg_info.ret_conv_name
 950                     else:
 951                         out_c = out_c + ", " + arg_info.arg_name
 952                 out_c = out_c + ");\n"
 953
 954                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 955                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 956                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
 957                 out_c += "\t}\n"
 958
 959                 if fn_line.ret_ty_info.arg_conv is not None:
 960                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
 961                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 962                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
 963                 else:
 964                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 965                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
 966                         out_c += "\treturn ret;\n"
 967
 968                 out_c = out_c + "}\n"
 969
 970         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
 971         can_clone_with_ptr = True
 972         for var in field_vars:
 973             if isinstance(var, ConvInfo):
 974                 can_clone_with_ptr = False
 975         if can_clone_with_ptr:
 976             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
 977             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
 978             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
 979             for var in field_vars:
 980                 if not isinstance(var, ConvInfo):
 981                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
 982             out_c = out_c + "}\n"
 983
 984         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
 985         for var in flattened_field_vars:
 986             if isinstance(var, ConvInfo):
 987                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
 988             else:
 989                 out_c = out_c + ", jobject " + var[1]
 990         out_c = out_c + ") {\n"
 991
 992         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
 993         out_c = out_c + "\tCHECK(c != NULL);\n"
 994         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
 995         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
 996         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
 997         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
 998
 999         for (fn_name, java_meth_descr) in java_meths:
1000             if fn_name != "free" and fn_name != "cloned":
1001                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
1002                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
1003
1004         for var in flattened_field_vars:
1005             if isinstance(var, ConvInfo) and var.arg_conv is not None:
1006                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
1007         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
1008         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
1009         for fn_line in field_fns:
1010             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1011                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1012             elif fn_line.fn_name == "free":
1013                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1014             else:
1015                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1016         for var in field_vars:
1017             if isinstance(var, ConvInfo):
1018                 if var.arg_conv_name is not None:
1019                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1020                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1021                 else:
1022                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1023                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1024             else:
1025                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1026                 for suparg in var[2]:
1027                     if isinstance(suparg, ConvInfo):
1028                         out_c = out_c + ", " + suparg.arg_name
1029                     else:
1030                         out_c = out_c + ", " + suparg[1]
1031                 out_c += "),\n"
1032         out_c = out_c + "\t};\n"
1033         for var in flattened_field_vars:
1034             if not isinstance(var, ConvInfo):
1035                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
1036         out_c = out_c + "\treturn ret;\n"
1037         out_c = out_c + "}\n"
1038
1039         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1040         for var in flattened_field_vars:
1041             if isinstance(var, ConvInfo):
1042                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1043             else:
1044                 out_c = out_c + ", jobject " + var[1]
1045         out_c = out_c + ") {\n"
1046         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1047         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1048         for var in flattened_field_vars:
1049             if isinstance(var, ConvInfo):
1050                 out_c = out_c + ", " + var.arg_name
1051             else:
1052                 out_c = out_c + ", " + var[1]
1053         out_c = out_c + ");\n"
1054         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1055         out_c = out_c + "}\n"
1056
1057         for var in flattened_field_vars:
1058             if not isinstance(var, ConvInfo):
1059                 out_java_trait += "\n\t/**\n"
1060                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1061                 out_java_trait += "\t */\n"
1062                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1063                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1064                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1065                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
1066                 out_java_trait += "\t\treturn res;\n"
1067                 out_java_trait += "\t}\n"
1068                 out_java_trait += "\n"
1069
1070                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1071
1072                 out_c += "JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_" + struct_name + "_1get_1" + var[1] + "(JNIEnv *env, jclass clz, int64_t arg) {\n"
1073                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1074                 out_c += "\treturn tag_ptr(&inp->" + var[1] + ", false);\n"
1075                 out_c += "}\n"
1076
1077         return (out_java, out_java_trait, out_c)
1078
1079     def trait_struct_inc_refcnt(self, ty_info):
1080         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1081         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1082         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1083         return base_conv
1084
1085     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1086         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1087         out_java_enum = ""
1088         out_java = ""
1089         out_c = ""
1090
1091         out_java_enum += (self.hu_struct_file_prefix)
1092         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1093         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1094         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1095         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1096         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1097         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1098         out_java_enum += ("\t\tsuper.finalize();\n")
1099         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1100         out_java_enum += ("\t}\n")
1101         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1102         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1103         java_hu_subclasses = ""
1104
1105         init_meth_jty_strs = {}
1106
1107         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1108         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1109         for var in variant_list:
1110             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1111             if var.var_docs is not None:
1112                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1113             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1114             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1115             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1116             init_meth_jty_str = ""
1117             init_meth_params = ""
1118             init_meth_body = ""
1119             hu_conv_body = ""
1120             for idx, (field_ty, field_docs) in enumerate(var.fields):
1121                 if idx > 0:
1122                     init_meth_params = init_meth_params + ", "
1123
1124                 java_ty = field_ty.java_ty
1125                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1126                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1127                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1128                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1129                 if field_docs is not None:
1130                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1131                 java_hu_subclasses += "\t\t"
1132                 if field_ty.nullable:
1133                     java_hu_subclasses += "@Nullable "
1134                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1135                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1136
1137                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1138                 if field_ty.to_hu_conv is not None:
1139                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1140                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1141                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1142                 else:
1143                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1144                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1145             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1146             out_java +=  (init_meth_body)
1147             out_java +=  ("}\n")
1148             out_java += ("\t\t}\n")
1149             out_java_enum += ("\t\t}\n")
1150             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"
1151             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1152             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1153             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1154         out_java += ("\t\tstatic native void init();\n")
1155         out_java += ("\t}\n")
1156         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1157         out_java_enum += (java_hu_subclasses)
1158         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1159         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1160
1161         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1162
1163         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")
1164         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1165         out_c += ("\tswitch(obj->tag) {\n")
1166         for var in variant_list:
1167             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1168             c_params = []
1169             for idx, (field_map, field_docs) in enumerate(var.fields):
1170                 if field_map.ret_conv is not None:
1171                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1172                     if var.tuple_variant:
1173                         out_c += "obj->" + camel_to_snake(var.var_name)
1174                     else:
1175                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1176                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1177                     c_params.append(field_map.ret_conv_name)
1178                 else:
1179                     if var.tuple_variant:
1180                         c_params.append("obj->" + camel_to_snake(var.var_name))
1181                     else:
1182                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1183             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1184             out_c += ("\t\t}\n")
1185         out_c += ("\t\tdefault: abort();\n")
1186         out_c += ("\t}\n}\n")
1187         return (out_java, out_java_enum, out_c)
1188
1189     def map_opaque_struct(self, struct_name, struct_doc_comment):
1190         out_opaque_struct_human = ""
1191         out_opaque_struct_human += self.hu_struct_file_prefix
1192         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1193         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1194         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1195         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1196         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1197             out_opaque_struct_human += (" implements AutoCloseable")
1198         out_opaque_struct_human += (" {\n")
1199         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1200         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1201             out_opaque_struct_human += ("\t@Override public void close() {\n")
1202         else:
1203             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1204             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1205             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1206         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1207         out_opaque_struct_human += ("\t}\n\n")
1208         return out_opaque_struct_human
1209
1210     def map_tuple(self, struct_name):
1211         return self.map_opaque_struct(struct_name, "A Tuple")
1212
1213     def map_result(self, struct_name, res_map, err_map):
1214         human_ty = struct_name.replace("LDKCResult", "Result")
1215         java_hu_struct = ""
1216         java_hu_struct += self.hu_struct_file_prefix
1217         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1218         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1219         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1220         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1221         java_hu_struct += "\t}\n\n"
1222         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1223         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1224         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1225         java_hu_struct += "\t\t} else {\n"
1226         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1227         java_hu_struct += "\t\t}\n"
1228         java_hu_struct += "\t}\n"
1229
1230         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1231
1232         if res_map.java_hu_ty != "void":
1233             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1234         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1235         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1236         if res_map.java_hu_ty == "void":
1237             pass
1238         elif res_map.to_hu_conv is not None:
1239             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1240             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1241             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1242         else:
1243             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1244         java_hu_struct += "\t\t}\n"
1245         java_hu_struct += "\t}\n\n"
1246
1247         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1248         if err_map.java_hu_ty != "void":
1249             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1250         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1251         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1252         if err_map.java_hu_ty == "void":
1253             pass
1254         elif err_map.to_hu_conv is not None:
1255             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1256             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1257             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1258         else:
1259             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1260         java_hu_struct += "\t\t}\n"
1261
1262         java_hu_struct += "\t}\n\n"
1263         return java_hu_struct
1264
1265     def map_function(self, argument_types, c_call_string, method_name, meth_n, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
1266         out_java = ""
1267         out_c = ""
1268         out_java_struct = None
1269
1270         out_java += ("\tpublic static native ")
1271         out_c += (self.c_fn_ty_pfx)
1272         out_c += (return_type_info.c_ty)
1273         out_java += (return_type_info.java_ty)
1274         if return_type_info.ret_conv is not None:
1275             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1276         out_java += (" " + method_name + "(")
1277         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1278         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1279
1280         for idx, arg_conv_info in enumerate(argument_types):
1281             if idx != 0:
1282                 out_java += (", ")
1283                 out_c += (", ")
1284             if arg_conv_info.c_ty != "void":
1285                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1286                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1287
1288         out_java_struct = ""
1289         extra_java_struct_out = ""
1290         if not args_known:
1291             out_java_struct += ("\t// Skipped " + method_name + "\n")
1292         else:
1293             if doc_comment is not None:
1294                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1295             if return_type_info.nullable:
1296                 out_java_struct += "\t@Nullable\n"
1297             if not takes_self:
1298                 if meth_n == "new":
1299                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1300                 elif meth_n == "default":
1301                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1302                 else:
1303                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1304             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1305                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1306             else:
1307                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1308                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1309                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1310                     extra_java_struct_out += "\t}\n"
1311                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1312                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1313                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1314                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1315                     extra_java_struct_out += "\t}\n"
1316                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1317             for idx, arg in enumerate(argument_types):
1318                 if idx != 0:
1319                     if not takes_self or idx > 1:
1320                         out_java_struct += ", "
1321                 elif takes_self:
1322                     continue
1323                 if arg.java_ty != "void":
1324                     if arg.arg_name in default_constructor_args:
1325                         assert not arg.nullable
1326                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1327                             if explode_idx != 0:
1328                                 out_java_struct += (", ")
1329                             out_java_struct += (
1330                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1331                     else:
1332                         if arg.nullable:
1333                             out_java_struct += "@Nullable "
1334                         ty_string = self.fully_qualified_hu_ty_path(arg)
1335                         out_java_struct += ty_string + " " + arg.arg_name
1336         out_java += (");\n")
1337         out_c += (") {\n")
1338         if out_java_struct is not None:
1339             out_java_struct += (") {\n")
1340         for info in argument_types:
1341             if info.arg_conv is not None:
1342                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1343         if return_type_info.ret_conv is not None:
1344             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1345         elif return_type_info.c_ty != "void":
1346             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1347         else:
1348             out_c += ("\t")
1349         if c_call_string is None:
1350             out_c += (method_name + "(")
1351         else:
1352             out_c += (c_call_string)
1353         for idx, info in enumerate(argument_types):
1354             if info.arg_conv_name is not None:
1355                 if idx != 0:
1356                     out_c += (", ")
1357                 elif c_call_string is not None:
1358                     continue
1359                 out_c += (info.arg_conv_name)
1360         out_c += (")")
1361         if return_type_info.ret_conv is not None:
1362             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1363         else:
1364             out_c += (";")
1365         for info in argument_types:
1366             if info.arg_conv_cleanup is not None:
1367                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1368         if return_type_info.ret_conv is not None:
1369             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1370         elif return_type_info.c_ty != "void":
1371             out_c += ("\n\treturn ret_val;")
1372         out_c += ("\n}\n\n")
1373
1374         if args_known:
1375             out_java_struct += ("\t\t")
1376             if return_type_info.java_ty != "void":
1377                 out_java_struct += (return_type_info.java_ty + " ret = ")
1378             out_java_struct += ("bindings." + method_name + "(")
1379             for idx, info in enumerate(argument_types):
1380                 if idx != 0:
1381                     out_java_struct += (", ")
1382                 if idx == 0 and takes_self:
1383                     out_java_struct += ("this.ptr")
1384                 elif info.arg_name in default_constructor_args:
1385                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1386                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1387                         if explode_idx != 0:
1388                             out_java_struct += (", ")
1389                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1390                         if explode_arg.from_hu_conv is not None:
1391                             out_java_struct += (
1392                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1393                         else:
1394                             out_java_struct += (expl_arg_name)
1395                     out_java_struct += (")")
1396                 elif info.from_hu_conv is not None:
1397                     out_java_struct += (info.from_hu_conv[0])
1398                 else:
1399                     out_java_struct += (info.arg_name)
1400             out_java_struct += (");\n")
1401
1402             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1403             # the stack, calling its finalizer immediately even if member methods are *actively
1404             # executing* on the same object, as long as said object is on the stack. There is no
1405             # concrete specification for when the optimizer is allowed to do this, and when it is
1406             # not, so there is absolutely no way to be certain that this fix suffices.
1407             #
1408             # Instead, the "Java Language Specification" says only that an object is reachable
1409             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1410             # computation from any live thread". To any sensible reader this would mean actively
1411             # executing a member function on an object would make it not eligible for finalization.
1412             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1413             # very explicitly in fact, but those are just, like, words, man.
1414             #
1415             # In the seemingly non-normative text further down, a few examples of things the
1416             # optimizer can do are given, including "if the values in an object's fields are
1417             # stored in registers[, t]he may then access the registers instead of the object, and
1418             # never access the object again[, implying] that the object is garbage". This appears
1419             # to fully contradict both the above statement, the API documentation in java.lang.ref
1420             # regarding when a reference is "strongly reachable", and basic common sense. There is
1421             # no concrete set of limitations stated, however, seemingly implying the JIT could
1422             # decide your code would run faster by simply garbage collecting everything
1423             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1424             # entirely flying blind here. We add some fences and hope that its sufficient, but
1425             # with no specification to rely on, we cannot be certain of anything.
1426             #
1427             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1428             # object will be considered available for garbage collection once the JIT kicks in, so
1429             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1430             for idx, info in enumerate(argument_types):
1431                 if idx == 0 and takes_self:
1432                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1433                 elif info.arg_name in default_constructor_args:
1434                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1435                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1436                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1437                 elif info.c_ty != "void":
1438                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1439
1440             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1441                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1442
1443             if return_type_info.to_hu_conv is not None:
1444                 if not takes_self:
1445                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1446                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1447                 else:
1448                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1449
1450             for idx, info in enumerate(argument_types):
1451                 if idx == 0 and takes_self:
1452                     pass
1453                 elif info.arg_name in default_constructor_args:
1454                     for explode_arg in default_constructor_args[info.arg_name]:
1455                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1456                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1457                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1458                                                                                                expl_arg_name).replace(
1459                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1460                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1461                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1462                         out_java_struct += (
1463                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1464                     else:
1465                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1466
1467             if takes_self and not takes_self_as_ref:
1468                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1469             if return_type_info.to_hu_conv_name is not None:
1470                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1471             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1472                 out_java_struct += ("\t\treturn ret;\n")
1473             out_java_struct += ("\t}\n\n")
1474
1475         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1476
1477     def cleanup(self):
1478         pass