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

   1 from bindingstypes import *
   2 from enum import Enum
   3 import sys
   4
   5 class Target(Enum):
   6     JAVA = 1,
   7     ANDROID = 2
   8
   9 class Consts:
  10     def __init__(self, DEBUG: bool, target: Target, **kwargs):
  11         self.target = target
  12         self.c_array_class_caches = set()
  13         self.c_type_map = dict(
  14             uint8_t = ['byte'],
  15             uint16_t = ['short'],
  16             uint32_t = ['int'],
  17             uint64_t = ['long'],
  18         )
  19         self.java_type_map = dict(
  20             String = "String"
  21         )
  22         self.java_hu_type_map = dict(
  23             String = "String"
  24         )
  25
  26         self.to_hu_conv_templates = dict(
  27             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}); }',
  28             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}); }'
  29         )
  30
  31         self.bindings_header = """package org.ldk.impl;
  32 import org.ldk.enums.*;
  33 import org.ldk.impl.version;
  34 import java.io.File;
  35 import java.io.InputStream;
  36 import java.io.IOException;
  37 import java.nio.file.Files;
  38 import java.nio.file.Path;
  39 import java.nio.file.StandardCopyOption;
  40
  41 public class bindings {
  42         static {
  43                 try {
  44                         // Try to load natively first, this works on Android and in testing.
  45                         System.loadLibrary(\"lightningjni\");
  46                 } catch (UnsatisfiedLinkError system_load_err) {
  47                         // Otherwise try to load from the library jar.
  48                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
  49                         tmpdir.mkdir(); // If it fails to create, assume it was there already
  50                         tmpdir.deleteOnExit();
  51                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
  52                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
  53                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
  54                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
  55                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
  56                                 Runtime.getRuntime().load(libpath.toString());
  57                         } catch (Exception e) {
  58                                 System.err.println("Failed to load LDK native library.");
  59                                 System.err.println("System LDK native library load failed with: " + system_load_err);
  60                                 System.err.println("Resource-based LDK native library load failed with: " + e);
  61                                 throw new IllegalArgumentException(e);
  62                         }
  63                 }
  64                 init(java.lang.Enum.class);
  65                 init_class_cache();
  66                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
  67                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
  68                 // Fetching the LDK versions from C also checks that the header and binaries match
  69                 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());
  70         }
  71         static native void init(java.lang.Class c);
  72         static native void init_class_cache();
  73         static native String get_lib_version_string();
  74
  75         public static native String get_ldk_c_bindings_version();
  76         public static native String get_ldk_version();
  77
  78 """
  79         self.bindings_version_file = """package org.ldk.impl;
  80
  81 public class version {
  82         public static String get_ldk_java_bindings_version() {
  83                 return "<git_version_ldk_garbagecollected>";
  84         }
  85 }"""
  86
  87         self.bindings_footer = "}\n"
  88
  89         self.util_fn_pfx = """package org.ldk.structs;
  90 import org.ldk.impl.bindings;
  91 import org.ldk.enums.*;
  92 import org.ldk.util.*;
  93 import java.util.Arrays;
  94 import java.lang.ref.Reference;
  95 import javax.annotation.Nullable;
  96
  97 public class UtilMethods {
  98 """
  99         self.util_fn_sfx = "}"
 100         self.common_base = """package org.ldk.structs;
 101 import java.util.LinkedList;
 102 class CommonBase {
 103         long ptr;
 104         LinkedList<Object> ptrs_to = new LinkedList();
 105         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
 106 }
 107 """
 108
 109         self.txout_defn = """public class TxOut extends CommonBase {
 110         /** The script_pubkey in this output */
 111         public final byte[] script_pubkey;
 112         /** The value, in satoshis, of this output */
 113         public final long value;
 114
 115         TxOut(java.lang.Object _dummy, long ptr) {
 116                 super(ptr);
 117                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 118                 this.value = bindings.TxOut_get_value(ptr);
 119         }
 120         public TxOut(long value, byte[] script_pubkey) {
 121                 super(bindings.TxOut_new(script_pubkey, value));
 122                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 123                 this.value = bindings.TxOut_get_value(ptr);
 124         }
 125
 126         @Override @SuppressWarnings(\"deprecation\")
 127         protected void finalize() throws Throwable {
 128                 super.finalize();
 129                 if (ptr != 0) { bindings.TxOut_free(ptr); }
 130         }
 131 }"""
 132
 133         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
 134         /** The bytes of the scalar value, in big endian */
 135         public final byte[] scalar_bytes;
 136
 137         BigEndianScalar(java.lang.Object _dummy, long ptr) {
 138                 super(ptr);
 139                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 140         }
 141         public BigEndianScalar(byte[] scalar_bytes) {
 142                 super(bindings.BigEndianScalar_new(scalar_bytes));
 143                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 144         }
 145
 146         @Override @SuppressWarnings(\"deprecation\")
 147         protected void finalize() throws Throwable {
 148                 super.finalize();
 149                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
 150         }
 151 }"""
 152
 153
 154         self.c_file_pfx = """#include <jni.h>
 155 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
 156 #define int64_t jlong
 157 #include \"org_ldk_impl_bindings.h\"
 158 #include <lightning.h>
 159 #include <string.h>
 160 #include <stdatomic.h>
 161 #include <stdlib.h>
 162
 163 #define LIKELY(v) __builtin_expect(!!(v), 1)
 164 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
 165
 166 """
 167
 168         if self.target == Target.ANDROID:
 169             self.c_file_pfx = self.c_file_pfx + """
 170 #include <android/log.h>
 171 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
 172
 173 #include <unistd.h>
 174 #include <pthread.h>
 175 static void* redirect_stderr(void* ignored) {
 176         int pipes[2];
 177         pipe(pipes);
 178         dup2(pipes[1], STDERR_FILENO);
 179         char buf[8192];
 180         memset(buf, 0, 8192);
 181         ssize_t len;
 182         while ((len = read(pipes[0], buf, 8191)) > 0) {
 183                 DEBUG_PRINT("%s\\n", buf);
 184                 memset(buf, 0, 8192);
 185         }
 186         DEBUG_PRINT("End of stderr???\\n");
 187         return 0;
 188 }
 189 void __attribute__((constructor)) spawn_stderr_redirection() {
 190         pthread_t thread;
 191         pthread_create(&thread, NULL, &redirect_stderr, NULL);
 192 }
 193 """
 194         else:
 195             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 196
 197         if not DEBUG or sys.platform == "darwin":
 198             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
 199 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
 200 #define CHECK_ACCESS(p)
 201 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
 202 """
 203         if not DEBUG:
 204             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
 205 #define CHECK(a)
 206 """
 207         if DEBUG:
 208             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
 209 // Always run a, then assert it is true:
 210 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 211 // Assert a is true or do nothing
 212 #define CHECK(a) DO_ASSERT(a)
 213
 214 void __attribute__((constructor)) debug_log_version() {
 215         if (check_get_ldk_version() == NULL)
 216                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
 217         if (check_get_ldk_bindings_version() == NULL)
 218                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
 219 }
 220 """
 221
 222             if sys.platform != "darwin":
 223                 self.c_file_pfx += """
 224 // Running a leak check across all the allocations and frees of the JDK is a mess,
 225 // so instead we implement our own naive leak checker here, relying on the -wrap
 226 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
 227 // and free'd in Rust or C across the generated bindings shared library.
 228 #include <threads.h>
 229 """
 230
 231                 if self.target == Target.ANDROID:
 232                     self.c_file_pfx = self.c_file_pfx + """
 233 #include <unwind.h>
 234 #include <dlfcn.h>
 235
 236 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
 237 // symbols, so we only use it on Android, where execinfo.h is unavailable.
 238
 239 struct BacktraceState {
 240         void** current;
 241         void** end;
 242 };
 243 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
 244         struct BacktraceState* state = (struct BacktraceState*)arg;
 245         uintptr_t pc = _Unwind_GetIP(context);
 246         if (pc) {
 247                 if (state->current == state->end) {
 248                         return _URC_END_OF_STACK;
 249                 } else {
 250                         *state->current++ = (void*)(pc);
 251                 }
 252         }
 253         return _URC_NO_REASON;
 254 }
 255
 256 int backtrace(void** buffer, int max) {
 257         struct BacktraceState state = { buffer, buffer + max };
 258         _Unwind_Backtrace(unwind_callback, &state);
 259         return state.current - buffer;
 260 }
 261
 262 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
 263         for (int idx = 0; idx < count; ++idx) {
 264                 Dl_info info;
 265                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
 266                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
 267                 } else {
 268                         DEBUG_PRINT("%p: ???", buffer[idx]);
 269                 }
 270         }
 271 }
 272 """
 273                 else:
 274                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
 275                 self.c_file_pfx = self.c_file_pfx + """
 276 #include <unistd.h>
 277 #include <pthread.h>
 278 static pthread_mutex_t allocation_mtx;
 279
 280 void __attribute__((constructor)) init_mtx() {
 281         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
 282 }
 283
 284 #define BT_MAX 128
 285 typedef struct allocation {
 286         struct allocation* next;
 287         void* ptr;
 288         const char* struct_name;
 289         void* bt[BT_MAX];
 290         int bt_len;
 291         unsigned long alloc_len;
 292 } allocation;
 293 static allocation* allocation_ll = NULL;
 294
 295 void* __real_malloc(size_t len);
 296 void* __real_calloc(size_t nmemb, size_t len);
 297 static void new_allocation(void* res, const char* struct_name, size_t len) {
 298         allocation* new_alloc = __real_malloc(sizeof(allocation));
 299         new_alloc->ptr = res;
 300         new_alloc->struct_name = struct_name;
 301         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
 302         new_alloc->alloc_len = len;
 303         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 304         new_alloc->next = allocation_ll;
 305         allocation_ll = new_alloc;
 306         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 307 }
 308 static void* MALLOC(size_t len, const char* struct_name) {
 309         void* res = __real_malloc(len);
 310         new_allocation(res, struct_name, len);
 311         return res;
 312 }
 313 void __real_free(void* ptr);
 314 static void alloc_freed(void* ptr) {
 315         allocation* p = NULL;
 316         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 317         allocation* it = allocation_ll;
 318         while (it->ptr != ptr) {
 319                 p = it; it = it->next;
 320                 if (it == NULL) {
 321                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
 322                         void* bt[BT_MAX];
 323                         int bt_len = backtrace(bt, BT_MAX);
 324                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 325                         DEBUG_PRINT("\\n\\n");
 326                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 327                         return; // addrsan should catch malloc-unknown and print more info than we have
 328                 }
 329         }
 330         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
 331         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 332         DO_ASSERT(it->ptr == ptr);
 333         __real_free(it);
 334 }
 335 static void FREE(void* ptr) {
 336         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
 337         alloc_freed(ptr);
 338         __real_free(ptr);
 339 }
 340
 341 void* __wrap_malloc(size_t len) {
 342         void* res = __real_malloc(len);
 343         new_allocation(res, "malloc call", len);
 344         return res;
 345 }
 346 void* __wrap_calloc(size_t nmemb, size_t len) {
 347         void* res = __real_calloc(nmemb, len);
 348         new_allocation(res, "calloc call", len);
 349         return res;
 350 }
 351 void __wrap_free(void* ptr) {
 352         if (ptr == NULL) return;
 353         alloc_freed(ptr);
 354         __real_free(ptr);
 355 }
 356
 357 static void CHECK_ACCESS(const void* ptr) {
 358         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 359         allocation* it = allocation_ll;
 360         while (it->ptr != ptr) {
 361                 it = it->next;
 362                 if (it == NULL) {
 363                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
 364                         void* bt[BT_MAX];
 365                         int bt_len = backtrace(bt, BT_MAX);
 366                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 367                         DEBUG_PRINT("\\n\\n");
 368                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 369                         return; // addrsan should catch and print more info than we have
 370                 }
 371         }
 372         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 373 }
 374 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
 375         if (v.is_owned && v.inner != NULL) { \\
 376                 const void *p = __unmangle_inner_ptr(v.inner); \\
 377                 if (p != NULL) { \\
 378                         CHECK_ACCESS(p); \\
 379                 } \\
 380         }
 381
 382 void* __real_realloc(void* ptr, size_t newlen);
 383 void* __wrap_realloc(void* ptr, size_t len) {
 384         if (ptr != NULL) alloc_freed(ptr);
 385         void* res = __real_realloc(ptr, len);
 386         new_allocation(res, "realloc call", len);
 387         return res;
 388 }
 389 void __wrap_reallocarray(void* ptr, size_t new_sz) {
 390         // Rust doesn't seem to use reallocarray currently
 391         DO_ASSERT(false);
 392 }
 393
 394 void __attribute__((destructor)) check_leaks() {
 395         unsigned long alloc_count = 0;
 396         unsigned long alloc_size = 0;
 397         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
 398         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 399         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 400         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
 401                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
 402                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
 403                 DEBUG_PRINT("\\n\\n");
 404                 alloc_count++;
 405                 alloc_size += a->alloc_len;
 406         }
 407         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
 408         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 409         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 410 }
 411 """
 412         self.c_file_pfx = self.c_file_pfx + """
 413 static jmethodID ordinal_meth = NULL;
 414 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
 415         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 416         CHECK(ordinal_meth != NULL);
 417 }
 418
 419 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 420 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 421 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
 422 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
 423
 424 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
 425 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
 426 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 427
 428 typedef jlongArray int64_tArray;
 429 typedef jbyteArray int8_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.c_fn_ty_pfx = "JNIEXPORT "
 478         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
 479         self.file_ext = ".java"
 480         self.ptr_c_ty = "int64_t"
 481         self.ptr_native_ty = "long"
 482         self.u128_native_ty = "UInt128"
 483         self.usize_c_ty = "int64_t"
 484         self.usize_native_ty = "long"
 485         self.native_zero_ptr = "0"
 486         self.result_c_ty = "jclass"
 487         self.ptr_arr = "jobjectArray"
 488         self.is_arr_some_check = ("", " != NULL")
 489         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
 490
 491     def construct_jenv(self):
 492         res =  "JNIEnv *env;\n"
 493         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
 494         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
 495         if self.target == Target.ANDROID:
 496             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
 497         else:
 498             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
 499         res += "} else {\n"
 500         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
 501         res += "}\n"
 502         return res
 503     def deconstruct_jenv(self):
 504         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
 505         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
 506         res += "}\n"
 507         return res
 508
 509     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
 510         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 511             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
 512         return None
 513     def create_native_arr_call(self, arr_len, ty_info):
 514         if ty_info.c_ty == "int8_tArray":
 515             return "(*env)->NewByteArray(env, " + arr_len + ")"
 516         elif ty_info.subty.c_ty.endswith("Array"):
 517             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
 518             self.c_array_class_caches.add(clz_var)
 519             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
 520         else:
 521             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
 522     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
 523         if ty_info.c_ty == "int8_tArray":
 524             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 525         else:
 526             assert False
 527     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
 528         if ty_info.c_ty == "int8_tArray":
 529             if copy:
 530                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
 531             else:
 532                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
 533         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
 534             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
 535         else:
 536             return None
 537     def get_native_arr_elem(self, arr_name, idxc, ty_info):
 538         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
 539             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
 540         else:
 541             assert False # Only called if above is None
 542     def get_native_arr_ptr_call(self, ty_info):
 543         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
 544             return None
 545         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 546     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
 547         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 548             return None
 549         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
 550     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
 551         if ty_info.c_ty == "int8_tArray":
 552             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
 553         else:
 554             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 555
 556     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
 557         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
 558             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 559         elif elem_ty.java_ty == "long":
 560             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 561         elif elem_ty.java_hu_ty == "UInt5":
 562             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
 563         elif elem_ty.java_hu_ty == "WitnessVersion":
 564             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
 565         else:
 566             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
 567
 568     def str_ref_to_native_call(self, var_name, str_len):
 569         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
 570     def str_ref_to_c_call(self, var_name):
 571         return "java_to_owned_str(env, " + var_name + ")"
 572     def str_to_hu_conv(self, var_name):
 573         return None
 574     def str_from_hu_conv(self, var_name):
 575         return None
 576
 577     def c_fn_name_define_pfx(self, fn_name, has_args):
 578         if has_args:
 579             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
 580         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
 581
 582     def init_str(self):
 583         res = ""
 584         for ty in sorted(self.c_array_class_caches):
 585             res = res + "static jclass " + ty + "_clz = NULL;\n"
 586         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
 587         for ty in sorted(self.c_array_class_caches):
 588             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
 589             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
 590             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
 591         res = res + "}\n"
 592         return res
 593
 594     def var_decl_statement(self, ty_string, var_name, statement):
 595         return ty_string + " " + var_name + " = " + statement
 596
 597     def get_java_arr_len(self, arr_name):
 598         return arr_name + ".length"
 599     def get_java_arr_elem(self, elem_ty, arr_name, idx):
 600         return arr_name + "[" + idx + "]"
 601     def constr_hu_array(self, ty_info, arr_len):
 602         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
 603         conv = "new " + base_ty + "[" + arr_len + "]"
 604         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
 605             # Do a bit of a dance to move any excess [] to the end
 606             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
 607         return conv
 608     def cleanup_converted_native_array(self, ty_info, arr_name):
 609         return None
 610
 611     def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
 612         mapped_ty = arr_ty.subty
 613         if arr_ty.rust_obj == "LDKU128":
 614             return ("" + arr_name + ".getLEBytes()", "")
 615         if fixed_len is not None:
 616             return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
 617         return None
 618     def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
 619         if arr_ty.rust_obj == "LDKU128":
 620             return "org.ldk.util.UInt128 " + conv_name + " = new org.ldk.util.UInt128(" + arr_name + ");"
 621         return None
 622
 623     def java_arr_ty_str(self, elem_ty_str):
 624         return elem_ty_str + "[]"
 625
 626     def for_n_in_range(self, n, minimum, maximum):
 627         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
 628     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
 629         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
 630
 631     def get_ptr(self, var):
 632         return var + ".ptr"
 633     def set_null_skip_free(self, var):
 634         return var + ".ptr" + " = 0;"
 635
 636     def add_ref(self, holder, referent):
 637         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
 638
 639     def fully_qualified_hu_ty_path(self, ty):
 640         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
 641             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
 642         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt128" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
 643             return "org.ldk.util." + ty.java_hu_ty
 644         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
 645             return "org.ldk.structs." + ty.java_hu_ty
 646         return ty.java_hu_ty
 647
 648     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
 649         out_java_enum = "package org.ldk.enums;\n\n"
 650         out_java = ""
 651         out_c = ""
 652         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
 653         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
 654         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 655         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 656         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
 657         out_c += "\t}\n"
 658         out_c += "\tswitch (ord) {\n"
 659
 660         if enum_doc_comment is not None:
 661             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 662         out_java_enum += "public enum " + struct_name + " {\n"
 663         ord_v = 0
 664         for var, var_docs in variants:
 665             if var_docs is not None:
 666                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
 667             out_java_enum += "\t" + var + ",\n"
 668             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
 669             ord_v = ord_v + 1
 670         out_java_enum = out_java_enum + "\t; static native void init();\n"
 671         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
 672         out_java_enum = out_java_enum + "}"
 673         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
 674         out_c += "\t}\n"
 675         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
 676         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
 677         out_c += "}\n"
 678
 679         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
 680         for var, _ in variants:
 681             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
 682         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"
 683         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
 684         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
 685         for var, _ in variants:
 686             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
 687             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
 688         out_c = out_c + "}\n"
 689         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
 690         out_c = out_c + "\tswitch (val) {\n"
 691         ord_v = 0
 692         for var, _ in variants:
 693             out_c = out_c + "\t\tcase " + var + ":\n"
 694             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
 695             ord_v = ord_v + 1
 696         out_c = out_c + "\t\tdefault: abort();\n"
 697         out_c = out_c + "\t}\n"
 698         out_c = out_c + "}\n\n"
 699
 700         return (out_c, out_java_enum, out_java)
 701
 702     def c_unitary_enum_to_native_call(self, ty_info):
 703         return (ty_info.rust_obj + "_to_java(env, ", ")")
 704     def native_unitary_enum_to_c_call(self, ty_info):
 705         return (ty_info.rust_obj + "_from_java(env, ", ")")
 706
 707     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
 708         out_c = ""
 709         for var in variants:
 710             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
 711             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
 712         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"
 713         for var_name in variants:
 714             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
 715             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
 716             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
 717             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"
 718             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
 719         out_c = out_c + "}\n"
 720         return out_c
 721
 722     def c_complex_enum_pass_ty(self, struct_name):
 723         return "jobject"
 724
 725     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
 726         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
 727         for param in c_params:
 728             ret = ret + ", " + param
 729         return ret + ")"
 730
 731     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
 732         out_java_trait = ""
 733         out_java = ""
 734
 735         # First generate most of the Java code, note that we need information about java method argument strings for C
 736         out_java_trait = out_java_trait + self.hu_struct_file_prefix
 737         if trait_doc_comment is not None:
 738             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
 739         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 740         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
 741         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
 742         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
 743         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
 744         for var in flattened_field_vars:
 745             if isinstance(var, ConvInfo):
 746                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
 747             else:
 748                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
 749         out_java_trait = out_java_trait + ") {\n"
 750         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
 751         for var in flattened_field_vars:
 752             if isinstance(var, ConvInfo):
 753                 if var.from_hu_conv is not None:
 754                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
 755                 else:
 756                     out_java_trait = out_java_trait + ", " + var.arg_name
 757             else:
 758                 out_java_trait = out_java_trait + ", " + var[1]
 759         out_java_trait = out_java_trait + "));\n"
 760         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
 761         for var in flattened_field_vars:
 762             if isinstance(var, ConvInfo):
 763                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
 764                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
 765             else:
 766                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
 767         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
 768         out_java_trait = out_java_trait + "\t}\n"
 769         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
 770         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
 771         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
 772         out_java_trait = out_java_trait + "\t}\n\n"
 773
 774         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
 775         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
 776         for var in flattened_field_vars:
 777             if isinstance(var, ConvInfo):
 778                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
 779             else:
 780                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
 781                 # Java-implemented version, so we require users pass a Java implementation here :/
 782                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
 783         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
 784         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
 785         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
 786         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
 787         java_meths = []
 788         for fn_line in field_fns:
 789             java_meth_descr = "("
 790             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 791                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 792                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 793                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
 794                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 795
 796                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
 797                     if idx >= 1:
 798                         out_java = out_java + ", "
 799                         java_trait_constr = java_trait_constr + ", "
 800                         out_java_trait = out_java_trait + ", "
 801                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 802                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
 803                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 804                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
 805                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
 806                 java_meths.append((fn_line.fn_name, java_meth_descr))
 807
 808                 out_java = out_java + ");\n"
 809                 out_java_trait = out_java_trait + ");\n"
 810                 java_trait_constr = java_trait_constr + ") {\n"
 811
 812                 for arg_info in fn_line.args_ty:
 813                     if arg_info.to_hu_conv is not None:
 814                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
 815
 816                 if fn_line.ret_ty_info.java_ty != "void":
 817                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
 818                 else:
 819                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
 820
 821                 for idx, arg_info in enumerate(fn_line.args_ty):
 822                     if idx != 0:
 823                         java_trait_constr = java_trait_constr + ", "
 824                     if arg_info.to_hu_conv_name is not None:
 825                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
 826                     else:
 827                         java_trait_constr = java_trait_constr + arg_info.arg_name
 828
 829                 java_trait_constr += ");\n"
 830                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
 831                 if fn_line.ret_ty_info.java_ty != "void":
 832                     if fn_line.ret_ty_info.from_hu_conv is not None:
 833                         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"
 834                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
 835                             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"
 836                         #if fn_line.ret_ty_info.rust_obj in result_types:
 837                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
 838                     else:
 839                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
 840                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
 841         java_trait_constr = java_trait_constr + "\t\t}"
 842         for var in field_vars:
 843             if isinstance(var, ConvInfo):
 844                 java_trait_constr = java_trait_constr + ", " + var.arg_name
 845             else:
 846                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
 847                 for suparg in var[2]:
 848                     if isinstance(suparg, ConvInfo):
 849                         java_trait_constr += ", " + suparg.arg_name
 850                     else:
 851                         java_trait_constr += ", " + suparg[1]
 852                 java_trait_constr += ").bindings_instance"
 853                 for suparg in var[2]:
 854                     if isinstance(suparg, ConvInfo):
 855                         java_trait_constr += ", " + suparg.arg_name
 856                     else:
 857                         java_trait_constr += ", " + suparg[1]
 858         out_java_trait = out_java_trait + "\t}\n"
 859         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 860
 861         out_java = out_java + "\t}\n"
 862
 863         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
 864         for var in flattened_field_vars:
 865             if isinstance(var, ConvInfo):
 866                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
 867             else:
 868                 out_java = out_java + ", " + var[0] + " " + var[1]
 869         out_java = out_java + ");\n"
 870
 871         # Now that we've written out our java code (and created java_meths), generate C
 872         out_c = "typedef struct " + struct_name + "_JCalls {\n"
 873         out_c = out_c + "\tatomic_size_t refcnt;\n"
 874         out_c = out_c + "\tJavaVM *vm;\n"
 875         out_c = out_c + "\tjweak o;\n"
 876         for var in flattened_field_vars:
 877             if isinstance(var, ConvInfo):
 878                 # We're a regular ol' field
 879                 pass
 880             else:
 881                 # We're a supertrait
 882                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
 883         for fn in field_fns:
 884             if fn.fn_name != "free" and fn.fn_name != "cloned":
 885                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
 886         out_c = out_c + "} " + struct_name + "_JCalls;\n"
 887
 888         for fn_line in field_fns:
 889             if fn_line.fn_name == "free":
 890                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
 891                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 892                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
 893                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 894                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
 895                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 896                 out_c = out_c + "\t\tFREE(j_calls);\n"
 897                 out_c = out_c + "\t}\n}\n"
 898
 899         for idx, fn_line in enumerate(field_fns):
 900             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 901                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
 902                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
 903                 if fn_line.self_is_const:
 904                     out_c = out_c + "const void* this_arg"
 905                 else:
 906                     out_c = out_c + "void* this_arg"
 907
 908                 for idx, arg in enumerate(fn_line.args_ty):
 909                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
 910
 911                 out_c = out_c + ") {\n"
 912                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 913                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 914
 915                 for arg_info in fn_line.args_ty:
 916                     if arg_info.ret_conv is not None:
 917                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
 918                         out_c = out_c + arg_info.arg_name
 919                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
 920
 921                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
 922                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
 923                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 924                 elif fn_line.ret_ty_info.c_ty == "void":
 925                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 926                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
 927                     # Manually write out String methods as they're just an Object
 928                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 929                 elif not fn_line.ret_ty_info.passed_as_ptr:
 930                     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"
 931                 else:
 932                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 933
 934                 for idx, arg_info in enumerate(fn_line.args_ty):
 935                     if arg_info.ret_conv is not None:
 936                         out_c = out_c + ", " + arg_info.ret_conv_name
 937                     else:
 938                         out_c = out_c + ", " + arg_info.arg_name
 939                 out_c = out_c + ");\n"
 940
 941                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 942                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 943                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
 944                 out_c += "\t}\n"
 945
 946                 if fn_line.ret_ty_info.arg_conv is not None:
 947                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
 948                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 949                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
 950                 else:
 951                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 952                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
 953                         out_c += "\treturn ret;\n"
 954
 955                 out_c = out_c + "}\n"
 956
 957         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
 958         can_clone_with_ptr = True
 959         for var in field_vars:
 960             if isinstance(var, ConvInfo):
 961                 can_clone_with_ptr = False
 962         if can_clone_with_ptr:
 963             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
 964             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
 965             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
 966             for var in field_vars:
 967                 if not isinstance(var, ConvInfo):
 968                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
 969             out_c = out_c + "}\n"
 970
 971         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
 972         for var in flattened_field_vars:
 973             if isinstance(var, ConvInfo):
 974                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
 975             else:
 976                 out_c = out_c + ", jobject " + var[1]
 977         out_c = out_c + ") {\n"
 978
 979         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
 980         out_c = out_c + "\tCHECK(c != NULL);\n"
 981         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
 982         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
 983         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
 984         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
 985
 986         for (fn_name, java_meth_descr) in java_meths:
 987             if fn_name != "free" and fn_name != "cloned":
 988                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
 989                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
 990
 991         for var in flattened_field_vars:
 992             if isinstance(var, ConvInfo) and var.arg_conv is not None:
 993                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
 994         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
 995         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
 996         for fn_line in field_fns:
 997             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 998                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
 999             elif fn_line.fn_name == "free":
1000                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1001             else:
1002                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1003         for var in field_vars:
1004             if isinstance(var, ConvInfo):
1005                 if var.arg_conv_name is not None:
1006                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1007                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1008                 else:
1009                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1010                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1011             else:
1012                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1013                 for suparg in var[2]:
1014                     if isinstance(suparg, ConvInfo):
1015                         out_c = out_c + ", " + suparg.arg_name
1016                     else:
1017                         out_c = out_c + ", " + suparg[1]
1018                 out_c += "),\n"
1019         out_c = out_c + "\t};\n"
1020         for var in flattened_field_vars:
1021             if not isinstance(var, ConvInfo):
1022                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
1023         out_c = out_c + "\treturn ret;\n"
1024         out_c = out_c + "}\n"
1025
1026         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1027         for var in flattened_field_vars:
1028             if isinstance(var, ConvInfo):
1029                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1030             else:
1031                 out_c = out_c + ", jobject " + var[1]
1032         out_c = out_c + ") {\n"
1033         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1034         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1035         for var in flattened_field_vars:
1036             if isinstance(var, ConvInfo):
1037                 out_c = out_c + ", " + var.arg_name
1038             else:
1039                 out_c = out_c + ", " + var[1]
1040         out_c = out_c + ");\n"
1041         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1042         out_c = out_c + "}\n"
1043
1044         for var in flattened_field_vars:
1045             if not isinstance(var, ConvInfo):
1046                 out_java_trait += "\n\t/**\n"
1047                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1048                 out_java_trait += "\t */\n"
1049                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1050                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1051                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1052                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
1053                 out_java_trait += "\t\treturn res;\n"
1054                 out_java_trait += "\t}\n"
1055                 out_java_trait += "\n"
1056
1057                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1058
1059                 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"
1060                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1061                 out_c += "\treturn tag_ptr(&inp->" + var[1] + ", false);\n"
1062                 out_c += "}\n"
1063
1064         return (out_java, out_java_trait, out_c)
1065
1066     def trait_struct_inc_refcnt(self, ty_info):
1067         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1068         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1069         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1070         return base_conv
1071
1072     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1073         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1074         out_java_enum = ""
1075         out_java = ""
1076         out_c = ""
1077
1078         out_java_enum += (self.hu_struct_file_prefix)
1079         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1080         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1081         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1082         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1083         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1084         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1085         out_java_enum += ("\t\tsuper.finalize();\n")
1086         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1087         out_java_enum += ("\t}\n")
1088         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1089         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1090         java_hu_subclasses = ""
1091
1092         init_meth_jty_strs = {}
1093
1094         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1095         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1096         for var in variant_list:
1097             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1098             if var.var_docs is not None:
1099                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1100             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1101             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1102             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1103             init_meth_jty_str = ""
1104             init_meth_params = ""
1105             init_meth_body = ""
1106             hu_conv_body = ""
1107             for idx, (field_ty, field_docs) in enumerate(var.fields):
1108                 if idx > 0:
1109                     init_meth_params = init_meth_params + ", "
1110
1111                 java_ty = field_ty.java_ty
1112                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1113                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1114                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1115                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1116                 if field_docs is not None:
1117                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1118                 java_hu_subclasses += "\t\t"
1119                 if field_ty.nullable:
1120                     java_hu_subclasses += "@Nullable "
1121                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1122                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1123
1124                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1125                 if field_ty.to_hu_conv is not None:
1126                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1127                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1128                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1129                 else:
1130                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1131                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1132             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1133             out_java +=  (init_meth_body)
1134             out_java +=  ("}\n")
1135             out_java += ("\t\t}\n")
1136             out_java_enum += ("\t\t}\n")
1137             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"
1138             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1139             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1140             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1141         out_java += ("\t\tstatic native void init();\n")
1142         out_java += ("\t}\n")
1143         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1144         out_java_enum += (java_hu_subclasses)
1145         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1146         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1147
1148         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1149
1150         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")
1151         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1152         out_c += ("\tswitch(obj->tag) {\n")
1153         for var in variant_list:
1154             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1155             c_params = []
1156             for idx, (field_map, field_docs) in enumerate(var.fields):
1157                 if field_map.ret_conv is not None:
1158                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1159                     if var.tuple_variant:
1160                         out_c += "obj->" + camel_to_snake(var.var_name)
1161                     else:
1162                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1163                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1164                     c_params.append(field_map.ret_conv_name)
1165                 else:
1166                     if var.tuple_variant:
1167                         c_params.append("obj->" + camel_to_snake(var.var_name))
1168                     else:
1169                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1170             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1171             out_c += ("\t\t}\n")
1172         out_c += ("\t\tdefault: abort();\n")
1173         out_c += ("\t}\n}\n")
1174         return (out_java, out_java_enum, out_c)
1175
1176     def map_opaque_struct(self, struct_name, struct_doc_comment):
1177         out_opaque_struct_human = ""
1178         out_opaque_struct_human += self.hu_struct_file_prefix
1179         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1180         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1181         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1182         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1183         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1184             out_opaque_struct_human += (" implements AutoCloseable")
1185         out_opaque_struct_human += (" {\n")
1186         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1187         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1188             out_opaque_struct_human += ("\t@Override public void close() {\n")
1189         else:
1190             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1191             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1192             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1193         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1194         out_opaque_struct_human += ("\t}\n\n")
1195         return out_opaque_struct_human
1196
1197     def map_tuple(self, struct_name):
1198         return self.map_opaque_struct(struct_name, "A Tuple")
1199
1200     def map_result(self, struct_name, res_map, err_map):
1201         human_ty = struct_name.replace("LDKCResult", "Result")
1202         java_hu_struct = ""
1203         java_hu_struct += self.hu_struct_file_prefix
1204         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1205         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1206         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1207         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1208         java_hu_struct += "\t}\n\n"
1209         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1210         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1211         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1212         java_hu_struct += "\t\t} else {\n"
1213         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1214         java_hu_struct += "\t\t}\n"
1215         java_hu_struct += "\t}\n"
1216
1217         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1218
1219         if res_map.java_hu_ty != "void":
1220             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1221         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1222         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1223         if res_map.java_hu_ty == "void":
1224             pass
1225         elif res_map.to_hu_conv is not None:
1226             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1227             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1228             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1229         else:
1230             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1231         java_hu_struct += "\t\t}\n"
1232         java_hu_struct += "\t}\n\n"
1233
1234         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1235         if err_map.java_hu_ty != "void":
1236             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1237         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1238         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1239         if err_map.java_hu_ty == "void":
1240             pass
1241         elif err_map.to_hu_conv is not None:
1242             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1243             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1244             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1245         else:
1246             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1247         java_hu_struct += "\t\t}\n"
1248
1249         java_hu_struct += "\t}\n\n"
1250         return java_hu_struct
1251
1252     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):
1253         out_java = ""
1254         out_c = ""
1255         out_java_struct = None
1256
1257         out_java += ("\tpublic static native ")
1258         out_c += (self.c_fn_ty_pfx)
1259         out_c += (return_type_info.c_ty)
1260         out_java += (return_type_info.java_ty)
1261         if return_type_info.ret_conv is not None:
1262             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1263         out_java += (" " + method_name + "(")
1264         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1265         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1266
1267         for idx, arg_conv_info in enumerate(argument_types):
1268             if idx != 0:
1269                 out_java += (", ")
1270                 out_c += (", ")
1271             if arg_conv_info.c_ty != "void":
1272                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1273                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1274
1275         out_java_struct = ""
1276         extra_java_struct_out = ""
1277         if not args_known:
1278             out_java_struct += ("\t// Skipped " + method_name + "\n")
1279         else:
1280             if doc_comment is not None:
1281                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1282             if return_type_info.nullable:
1283                 out_java_struct += "\t@Nullable\n"
1284             if not takes_self:
1285                 if meth_n == "new":
1286                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1287                 elif meth_n == "default":
1288                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1289                 else:
1290                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1291             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1292                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1293             else:
1294                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1295                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1296                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1297                     extra_java_struct_out += "\t}\n"
1298                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1299                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1300                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1301                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1302                     extra_java_struct_out += "\t}\n"
1303                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1304             for idx, arg in enumerate(argument_types):
1305                 if idx != 0:
1306                     if not takes_self or idx > 1:
1307                         out_java_struct += ", "
1308                 elif takes_self:
1309                     continue
1310                 if arg.java_ty != "void":
1311                     if arg.arg_name in default_constructor_args:
1312                         assert not arg.nullable
1313                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1314                             if explode_idx != 0:
1315                                 out_java_struct += (", ")
1316                             out_java_struct += (
1317                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1318                     else:
1319                         if arg.nullable:
1320                             out_java_struct += "@Nullable "
1321                         ty_string = arg.java_hu_ty
1322                         if arg.java_fn_ty_arg[0] == "L" and arg.java_fn_ty_arg[len(arg.java_fn_ty_arg) - 1] == ";":
1323                             ty_string = arg.java_fn_ty_arg.strip("L;").replace("/", ".")
1324                         out_java_struct += ty_string + " " + arg.arg_name
1325         out_java += (");\n")
1326         out_c += (") {\n")
1327         if out_java_struct is not None:
1328             out_java_struct += (") {\n")
1329         for info in argument_types:
1330             if info.arg_conv is not None:
1331                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1332         if return_type_info.ret_conv is not None:
1333             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1334         elif return_type_info.c_ty != "void":
1335             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1336         else:
1337             out_c += ("\t")
1338         if c_call_string is None:
1339             out_c += (method_name + "(")
1340         else:
1341             out_c += (c_call_string)
1342         for idx, info in enumerate(argument_types):
1343             if info.arg_conv_name is not None:
1344                 if idx != 0:
1345                     out_c += (", ")
1346                 elif c_call_string is not None:
1347                     continue
1348                 out_c += (info.arg_conv_name)
1349         out_c += (")")
1350         if return_type_info.ret_conv is not None:
1351             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1352         else:
1353             out_c += (";")
1354         for info in argument_types:
1355             if info.arg_conv_cleanup is not None:
1356                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1357         if return_type_info.ret_conv is not None:
1358             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1359         elif return_type_info.c_ty != "void":
1360             out_c += ("\n\treturn ret_val;")
1361         out_c += ("\n}\n\n")
1362
1363         if args_known:
1364             out_java_struct += ("\t\t")
1365             if return_type_info.java_ty != "void":
1366                 out_java_struct += (return_type_info.java_ty + " ret = ")
1367             out_java_struct += ("bindings." + method_name + "(")
1368             for idx, info in enumerate(argument_types):
1369                 if idx != 0:
1370                     out_java_struct += (", ")
1371                 if idx == 0 and takes_self:
1372                     out_java_struct += ("this.ptr")
1373                 elif info.arg_name in default_constructor_args:
1374                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1375                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1376                         if explode_idx != 0:
1377                             out_java_struct += (", ")
1378                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1379                         if explode_arg.from_hu_conv is not None:
1380                             out_java_struct += (
1381                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1382                         else:
1383                             out_java_struct += (expl_arg_name)
1384                     out_java_struct += (")")
1385                 elif info.from_hu_conv is not None:
1386                     out_java_struct += (info.from_hu_conv[0])
1387                 else:
1388                     out_java_struct += (info.arg_name)
1389             out_java_struct += (");\n")
1390
1391             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1392             # the stack, calling its finalizer immediately even if member methods are *actively
1393             # executing* on the same object, as long as said object is on the stack. There is no
1394             # concrete specification for when the optimizer is allowed to do this, and when it is
1395             # not, so there is absolutely no way to be certain that this fix suffices.
1396             #
1397             # Instead, the "Java Language Specification" says only that an object is reachable
1398             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1399             # computation from any live thread". To any sensible reader this would mean actively
1400             # executing a member function on an object would make it not eligible for finalization.
1401             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1402             # very explicitly in fact, but those are just, like, words, man.
1403             #
1404             # In the seemingly non-normative text further down, a few examples of things the
1405             # optimizer can do are given, including "if the values in an object's fields are
1406             # stored in registers[, t]he may then access the registers instead of the object, and
1407             # never access the object again[, implying] that the object is garbage". This appears
1408             # to fully contradict both the above statement, the API documentation in java.lang.ref
1409             # regarding when a reference is "strongly reachable", and basic common sense. There is
1410             # no concrete set of limitations stated, however, seemingly implying the JIT could
1411             # decide your code would run faster by simply garbage collecting everything
1412             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1413             # entirely flying blind here. We add some fences and hope that its sufficient, but
1414             # with no specification to rely on, we cannot be certain of anything.
1415             #
1416             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1417             # object will be considered available for garbage collection once the JIT kicks in, so
1418             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1419             for idx, info in enumerate(argument_types):
1420                 if idx == 0 and takes_self:
1421                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1422                 elif info.arg_name in default_constructor_args:
1423                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1424                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1425                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1426                 elif info.c_ty != "void":
1427                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1428
1429             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1430                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1431
1432             if return_type_info.to_hu_conv is not None:
1433                 if not takes_self:
1434                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1435                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1436                 else:
1437                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1438
1439             for idx, info in enumerate(argument_types):
1440                 if idx == 0 and takes_self:
1441                     pass
1442                 elif info.arg_name in default_constructor_args:
1443                     for explode_arg in default_constructor_args[info.arg_name]:
1444                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1445                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1446                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1447                                                                                                expl_arg_name).replace(
1448                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1449                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1450                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1451                         out_java_struct += (
1452                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1453                     else:
1454                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1455
1456             if takes_self and not takes_self_as_ref:
1457                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1458             if return_type_info.to_hu_conv_name is not None:
1459                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1460             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1461                 out_java_struct += ("\t\treturn ret;\n")
1462             out_java_struct += ("\t}\n\n")
1463
1464         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1465
1466     def cleanup(self):
1467         pass