_ 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     MACOS = 3
   9
  10 class Consts:
  11     def __init__(self, DEBUG: bool, target: Target, **kwargs):
  12         self.target = target
  13         self.c_array_class_caches = set()
  14         self.c_type_map = dict(
  15             bool = ['boolean'],
  16             uint8_t = ['byte'],
  17             uint16_t = ['short'],
  18             uint32_t = ['int'],
  19             uint64_t = ['long'],
  20         )
  21         self.java_type_map = dict(
  22             String = "String"
  23         )
  24         self.java_hu_type_map = dict(
  25             String = "String"
  26         )
  27
  28         self.to_hu_conv_templates = dict(
  29             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}); }',
  30             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}); }'
  31         )
  32
  33         self.bindings_header = """package org.ldk.impl;
  34 import org.ldk.enums.*;
  35 import org.ldk.impl.version;
  36 import java.io.File;
  37 import java.io.InputStream;
  38 import java.io.IOException;
  39 import java.nio.file.Files;
  40 import java.nio.file.Path;
  41 import java.nio.file.StandardCopyOption;
  42
  43 public class bindings {
  44         static {
  45                 try {
  46                         // Try to load natively first, this works on Android and in testing.
  47                         System.loadLibrary(\"lightningjni\");
  48                 } catch (UnsatisfiedLinkError system_load_err) {
  49                         // Otherwise try to load from the library jar.
  50                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
  51                         tmpdir.mkdir(); // If it fails to create, assume it was there already
  52                         tmpdir.deleteOnExit();
  53                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
  54                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
  55                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
  56                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
  57                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
  58                                 Runtime.getRuntime().load(libpath.toString());
  59                         } catch (Exception e) {
  60                                 System.err.println("Failed to load LDK native library.");
  61                                 System.err.println("System LDK native library load failed with: " + system_load_err);
  62                                 System.err.println("Resource-based LDK native library load failed with: " + e);
  63                                 throw new IllegalArgumentException(e);
  64                         }
  65                 }
  66                 init(java.lang.Enum.class);
  67                 init_class_cache();
  68                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
  69                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
  70                 // Fetching the LDK versions from C also checks that the header and binaries match
  71                 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());
  72         }
  73         static native void init(java.lang.Class c);
  74         static native void init_class_cache();
  75         static native String get_lib_version_string();
  76
  77         public static native String get_ldk_c_bindings_version();
  78         public static native String get_ldk_version();
  79
  80 """
  81         self.bindings_version_file = """package org.ldk.impl;
  82
  83 public class version {
  84         public static String get_ldk_java_bindings_version() {
  85                 return "<git_version_ldk_garbagecollected>";
  86         }
  87 }"""
  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.txin_defn = """public class TxIn extends CommonBase {
 134         /** The witness in this input, in serialized form */
 135         public final byte[] witness;
 136         /** The script_sig in this input */
 137         public final byte[] script_sig;
 138         /** The transaction output's sequence number */
 139         public final int sequence;
 140         /** The txid this input is spending */
 141         public final byte[] previous_txid;
 142         /** The output index within the spent transaction of the output this input is spending */
 143         public final int previous_vout;
 144
 145         TxIn(java.lang.Object _dummy, long ptr) {
 146                 super(ptr);
 147                 this.witness = bindings.TxIn_get_witness(ptr);
 148                 this.script_sig = bindings.TxIn_get_script_sig(ptr);
 149                 this.sequence = bindings.TxIn_get_sequence(ptr);
 150                 this.previous_txid = bindings.TxIn_get_previous_txid(ptr);
 151                 this.previous_vout = bindings.TxIn_get_previous_vout(ptr);
 152         }
 153         /** Constructs a new TxIn, note that previous_txid must be exactly 32 bytes */
 154         public TxIn(byte[] witness, byte[] script_sig, int sequence, byte[] previous_txid, int previous_vout) {
 155                 this(null, bindings.TxIn_new(witness, script_sig, sequence, previous_txid, previous_vout));
 156         }
 157
 158         @Override @SuppressWarnings(\"deprecation\")
 159         protected void finalize() throws Throwable {
 160                 super.finalize();
 161                 if (ptr != 0) { bindings.TxIn_free(ptr); }
 162         }
 163 }"""
 164
 165         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
 166         /** The bytes of the scalar value, in big endian */
 167         public final byte[] scalar_bytes;
 168
 169         BigEndianScalar(java.lang.Object _dummy, long ptr) {
 170                 super(ptr);
 171                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 172         }
 173         public BigEndianScalar(byte[] scalar_bytes) {
 174                 super(bindings.BigEndianScalar_new(scalar_bytes));
 175                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 176         }
 177
 178         @Override @SuppressWarnings(\"deprecation\")
 179         protected void finalize() throws Throwable {
 180                 super.finalize();
 181                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
 182         }
 183 }"""
 184
 185
 186         self.c_file_pfx = """#include <jni.h>
 187 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
 188 #define int64_t jlong
 189 #include \"org_ldk_impl_bindings.h\"
 190 #include <lightning.h>
 191 #include <string.h>
 192 #include <stdatomic.h>
 193 #include <stdlib.h>
 194
 195 #define LIKELY(v) __builtin_expect(!!(v), 1)
 196 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
 197
 198 """
 199
 200         if self.target == Target.ANDROID:
 201             self.c_file_pfx = self.c_file_pfx + """
 202 #include <android/log.h>
 203 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
 204
 205 #include <unistd.h>
 206 #include <pthread.h>
 207 static void* redirect_stderr(void* ignored) {
 208         int pipes[2];
 209         pipe(pipes);
 210         dup2(pipes[1], STDERR_FILENO);
 211         char buf[8192];
 212         memset(buf, 0, 8192);
 213         ssize_t len;
 214         while ((len = read(pipes[0], buf, 8191)) > 0) {
 215                 DEBUG_PRINT("%s\\n", buf);
 216                 memset(buf, 0, 8192);
 217         }
 218         DEBUG_PRINT("End of stderr???\\n");
 219         return 0;
 220 }
 221 void __attribute__((constructor)) spawn_stderr_redirection() {
 222         pthread_t thread;
 223         pthread_create(&thread, NULL, &redirect_stderr, NULL);
 224 }
 225 """
 226         else:
 227             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 228
 229         if not DEBUG or self.target == Target.MACOS:
 230             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
 231 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
 232 #define CHECK_ACCESS(p)
 233 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
 234 """
 235         if not DEBUG:
 236             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
 237 #define CHECK(a)
 238 """
 239         if DEBUG:
 240             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
 241 // Always run a, then assert it is true:
 242 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 243 // Assert a is true or do nothing
 244 #define CHECK(a) DO_ASSERT(a)
 245
 246 void __attribute__((constructor)) debug_log_version() {
 247         if (check_get_ldk_version() == NULL)
 248                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
 249         if (check_get_ldk_bindings_version() == NULL)
 250                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
 251 }
 252 """
 253
 254             if self.target != Target.MACOS:
 255                 self.c_file_pfx += """
 256 // Running a leak check across all the allocations and frees of the JDK is a mess,
 257 // so instead we implement our own naive leak checker here, relying on the -wrap
 258 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
 259 // and free'd in Rust or C across the generated bindings shared library.
 260 #include <threads.h>
 261 """
 262
 263                 if self.target == Target.ANDROID:
 264                     self.c_file_pfx = self.c_file_pfx + """
 265 #include <unwind.h>
 266 #include <dlfcn.h>
 267
 268 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
 269 // symbols, so we only use it on Android, where execinfo.h is unavailable.
 270
 271 struct BacktraceState {
 272         void** current;
 273         void** end;
 274 };
 275 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
 276         struct BacktraceState* state = (struct BacktraceState*)arg;
 277         uintptr_t pc = _Unwind_GetIP(context);
 278         if (pc) {
 279                 if (state->current == state->end) {
 280                         return _URC_END_OF_STACK;
 281                 } else {
 282                         *state->current++ = (void*)(pc);
 283                 }
 284         }
 285         return _URC_NO_REASON;
 286 }
 287
 288 int backtrace(void** buffer, int max) {
 289         struct BacktraceState state = { buffer, buffer + max };
 290         _Unwind_Backtrace(unwind_callback, &state);
 291         return state.current - buffer;
 292 }
 293
 294 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
 295         for (int idx = 0; idx < count; ++idx) {
 296                 Dl_info info;
 297                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
 298                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
 299                 } else {
 300                         DEBUG_PRINT("%p: ???", buffer[idx]);
 301                 }
 302         }
 303 }
 304 """
 305                 else:
 306                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
 307                 self.c_file_pfx = self.c_file_pfx + """
 308 #include <unistd.h>
 309 #include <pthread.h>
 310 static pthread_mutex_t allocation_mtx;
 311
 312 void __attribute__((constructor)) init_mtx() {
 313         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
 314 }
 315
 316 #define BT_MAX 128
 317 typedef struct allocation {
 318         struct allocation* next;
 319         void* ptr;
 320         const char* struct_name;
 321         void* bt[BT_MAX];
 322         int bt_len;
 323         unsigned long alloc_len;
 324 } allocation;
 325 static allocation* allocation_ll = NULL;
 326
 327 void* __real_malloc(size_t len);
 328 void* __real_calloc(size_t nmemb, size_t len);
 329 static void new_allocation(void* res, const char* struct_name, size_t len) {
 330         allocation* new_alloc = __real_malloc(sizeof(allocation));
 331         new_alloc->ptr = res;
 332         new_alloc->struct_name = struct_name;
 333         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
 334         new_alloc->alloc_len = len;
 335         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 336         new_alloc->next = allocation_ll;
 337         allocation_ll = new_alloc;
 338         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 339 }
 340 static void* MALLOC(size_t len, const char* struct_name) {
 341         void* res = __real_malloc(len);
 342         new_allocation(res, struct_name, len);
 343         return res;
 344 }
 345 void __real_free(void* ptr);
 346 static void alloc_freed(void* ptr) {
 347         allocation* p = NULL;
 348         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 349         allocation* it = allocation_ll;
 350         while (it->ptr != ptr) {
 351                 p = it; it = it->next;
 352                 if (it == NULL) {
 353                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
 354                         void* bt[BT_MAX];
 355                         int bt_len = backtrace(bt, BT_MAX);
 356                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 357                         DEBUG_PRINT("\\n\\n");
 358                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 359                         return; // addrsan should catch malloc-unknown and print more info than we have
 360                 }
 361         }
 362         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
 363         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 364         DO_ASSERT(it->ptr == ptr);
 365         __real_free(it);
 366 }
 367 static void FREE(void* ptr) {
 368         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
 369         alloc_freed(ptr);
 370         __real_free(ptr);
 371 }
 372
 373 void* __wrap_malloc(size_t len) {
 374         void* res = __real_malloc(len);
 375         new_allocation(res, "malloc call", len);
 376         return res;
 377 }
 378 void* __wrap_calloc(size_t nmemb, size_t len) {
 379         void* res = __real_calloc(nmemb, len);
 380         new_allocation(res, "calloc call", len);
 381         return res;
 382 }
 383 void __wrap_free(void* ptr) {
 384         if (ptr == NULL) return;
 385         alloc_freed(ptr);
 386         __real_free(ptr);
 387 }
 388
 389 static void CHECK_ACCESS(const void* ptr) {
 390         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 391         allocation* it = allocation_ll;
 392         while (it->ptr != ptr) {
 393                 it = it->next;
 394                 if (it == NULL) {
 395                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
 396                         void* bt[BT_MAX];
 397                         int bt_len = backtrace(bt, BT_MAX);
 398                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 399                         DEBUG_PRINT("\\n\\n");
 400                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 401                         return; // addrsan should catch and print more info than we have
 402                 }
 403         }
 404         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 405 }
 406 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
 407         if (v.is_owned && v.inner != NULL) { \\
 408                 const void *p = __unmangle_inner_ptr(v.inner); \\
 409                 if (p != NULL) { \\
 410                         CHECK_ACCESS(p); \\
 411                 } \\
 412         }
 413
 414 void* __real_realloc(void* ptr, size_t newlen);
 415 void* __wrap_realloc(void* ptr, size_t len) {
 416         if (ptr != NULL) alloc_freed(ptr);
 417         void* res = __real_realloc(ptr, len);
 418         new_allocation(res, "realloc call", len);
 419         return res;
 420 }
 421 void __wrap_reallocarray(void* ptr, size_t new_sz) {
 422         // Rust doesn't seem to use reallocarray currently
 423         DO_ASSERT(false);
 424 }
 425
 426 void __attribute__((destructor)) check_leaks() {
 427         unsigned long alloc_count = 0;
 428         unsigned long alloc_size = 0;
 429         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
 430         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 431         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 432         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
 433                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
 434                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
 435                 DEBUG_PRINT("\\n\\n");
 436                 alloc_count++;
 437                 alloc_size += a->alloc_len;
 438         }
 439         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
 440         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 441         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 442 }
 443 """
 444         self.c_file_pfx = self.c_file_pfx + """
 445 static jmethodID ordinal_meth = NULL;
 446 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
 447         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 448         CHECK(ordinal_meth != NULL);
 449 }
 450
 451 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 452 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 453 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
 454 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
 455
 456 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
 457 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
 458 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 459
 460 typedef jlongArray int64_tArray;
 461 typedef jbyteArray int8_tArray;
 462 typedef jshortArray int16_tArray;
 463
 464 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
 465         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
 466         char* conv_buf = MALLOC(len + 1, "str conv buf");
 467         memcpy(conv_buf, chars, len);
 468         conv_buf[len] = 0;
 469         jstring ret = (*env)->NewStringUTF(env, conv_buf);
 470         FREE(conv_buf);
 471         return ret;
 472 }
 473 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
 474         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
 475         char* newchars = MALLOC(str_len + 1, "String chars");
 476         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
 477         memcpy(newchars, jchars, str_len);
 478         newchars[str_len] = 0;
 479         (*env)->ReleaseStringUTFChars(env, str, jchars);
 480         LDKStr res = {
 481                 .chars = newchars,
 482                 .len = str_len,
 483                 .chars_is_owned = true
 484         };
 485         return res;
 486 }
 487
 488 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
 489         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
 490 }
 491 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
 492         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
 493 }
 494 #include "version.c"
 495 """
 496         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
 497         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
 498 }"""
 499
 500         self.hu_struct_file_prefix = """package org.ldk.structs;
 501
 502 import org.ldk.impl.bindings;
 503 import org.ldk.enums.*;
 504 import org.ldk.util.*;
 505 import java.util.Arrays;
 506 import java.lang.ref.Reference;
 507 import javax.annotation.Nullable;
 508
 509 """
 510         self.hu_struct_file_suffix = ""
 511         self.c_fn_ty_pfx = "JNIEXPORT "
 512         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
 513         self.file_ext = ".java"
 514         self.ptr_c_ty = "int64_t"
 515         self.ptr_native_ty = "long"
 516         self.u128_native_ty = "UInt128"
 517         self.usize_c_ty = "int64_t"
 518         self.usize_native_ty = "long"
 519         self.native_zero_ptr = "0"
 520         self.result_c_ty = "jclass"
 521         self.ptr_arr = "jobjectArray"
 522         self.is_arr_some_check = ("", " != NULL")
 523         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
 524
 525     def bindings_footer(self):
 526         return "}\n"
 527
 528     def construct_jenv(self):
 529         res =  "JNIEnv *env;\n"
 530         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
 531         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
 532         if self.target == Target.ANDROID:
 533             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
 534         else:
 535             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
 536         res += "} else {\n"
 537         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
 538         res += "}\n"
 539         return res
 540     def deconstruct_jenv(self):
 541         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
 542         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
 543         res += "}\n"
 544         return res
 545
 546     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
 547         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 548             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
 549         return None
 550     def create_native_arr_call(self, arr_len, ty_info):
 551         if ty_info.c_ty == "int8_tArray":
 552             return "(*env)->NewByteArray(env, " + arr_len + ")"
 553         elif ty_info.subty.c_ty.endswith("Array"):
 554             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
 555             self.c_array_class_caches.add(clz_var)
 556             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
 557         elif ty_info.subty.c_ty == "jstring":
 558             return "(*env)->NewObjectArray(env, " + arr_len + ", String_clz, NULL);\n"
 559         else:
 560             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
 561     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
 562         if ty_info.c_ty == "int8_tArray":
 563             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 564         elif ty_info.c_ty == "int16_tArray":
 565             return ("(*env)->SetShortArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 566         else:
 567             assert False
 568     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
 569         if "String" in ty_info.java_ty:
 570             return None
 571         if ty_info.c_ty == "int8_tArray" or ty_info.c_ty == "int16_tArray":
 572             fn_ty = "Byte" if ty_info.c_ty == "int8_tArray" else "Short"
 573             if copy:
 574                 return "(*env)->Get" + fn_ty + "ArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
 575             else:
 576                 return "(*env)->Get" + fn_ty + "ArrayElements (env, " + arr_name + ", NULL)"
 577         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
 578             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
 579         else:
 580             return None
 581     def get_native_arr_elem(self, arr_name, idxc, ty_info):
 582         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
 583             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
 584         else:
 585             assert False # Only called if above is None
 586     def get_native_arr_ptr_call(self, ty_info):
 587         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
 588             return None
 589         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 590     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
 591         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 592             return None
 593         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
 594     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
 595         if ty_info.c_ty == "int8_tArray":
 596             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
 597         else:
 598             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 599
 600     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
 601         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
 602             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 603         elif elem_ty.java_ty == "long":
 604             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 605         elif elem_ty.java_hu_ty == "UInt5":
 606             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
 607         elif elem_ty.java_hu_ty == "WitnessVersion":
 608             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
 609         else:
 610             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
 611
 612     def str_ref_to_native_call(self, var_name, str_len):
 613         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
 614     def str_ref_to_c_call(self, var_name):
 615         return "java_to_owned_str(env, " + var_name + ")"
 616     def str_to_hu_conv(self, var_name):
 617         return None
 618     def str_from_hu_conv(self, var_name):
 619         return None
 620
 621     def c_fn_name_define_pfx(self, fn_name, has_args):
 622         if has_args:
 623             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
 624         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
 625
 626     def init_str(self):
 627         res = ""
 628         for ty in sorted(self.c_array_class_caches):
 629             res = res + "static jclass " + ty + "_clz = NULL;\n"
 630         res = res + "static jclass String_clz = NULL;\n"
 631         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
 632         for ty in sorted(self.c_array_class_caches):
 633             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
 634             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
 635             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
 636         res = res + "\tString_clz = (*env)->FindClass(env, \"java/lang/String\");\n"
 637         res = res + "\tCHECK(String_clz != NULL);\n"
 638         res = res + "\tString_clz = (*env)->NewGlobalRef(env, String_clz);\n"
 639
 640         res = res + "}\n"
 641         return res
 642
 643     def var_decl_statement(self, ty_string, var_name, statement):
 644         return ty_string + " " + var_name + " = " + statement
 645
 646     def get_java_arr_len(self, arr_name):
 647         return arr_name + ".length"
 648     def get_java_arr_elem(self, elem_ty, arr_name, idx):
 649         return arr_name + "[" + idx + "]"
 650     def constr_hu_array(self, ty_info, arr_len):
 651         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
 652         conv = "new " + base_ty + "[" + arr_len + "]"
 653         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
 654             # Do a bit of a dance to move any excess [] to the end
 655             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
 656         return conv
 657     def cleanup_converted_native_array(self, ty_info, arr_name):
 658         return None
 659
 660     def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
 661         mapped_ty = arr_ty.subty
 662         if arr_ty.rust_obj == "LDKU128":
 663             return ("" + arr_name + ".getLEBytes()", "")
 664         if fixed_len is not None:
 665             if mapped_ty.c_ty == "int8_t" or mapped_ty.c_ty == "uint8_t":
 666                 return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
 667             elif mapped_ty.c_ty == "int16_t" or mapped_ty.c_ty == "uint16_t":
 668                 return ("InternalUtils.check_arr_16_len(" + arr_name + ", " + fixed_len + ")", "")
 669             else:
 670                 print(arr_ty.c_ty)
 671                 assert False
 672         return None
 673     def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
 674         if arr_ty.rust_obj == "LDKU128":
 675             return "org.ldk.util.UInt128 " + conv_name + " = new org.ldk.util.UInt128(" + arr_name + ");"
 676         return None
 677
 678     def java_arr_ty_str(self, elem_ty_str):
 679         return elem_ty_str + "[]"
 680
 681     def for_n_in_range(self, n, minimum, maximum):
 682         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
 683     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
 684         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
 685
 686     def get_ptr(self, var):
 687         return var + ".ptr"
 688     def set_null_skip_free(self, var):
 689         return var + ".ptr" + " = 0;"
 690
 691     def add_ref(self, holder, referent):
 692         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
 693
 694     def fully_qualified_hu_ty_path(self, ty):
 695         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
 696             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
 697         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt128" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
 698             return "org.ldk.util." + ty.java_hu_ty
 699         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
 700             return "org.ldk.structs." + ty.java_hu_ty
 701         return ty.java_hu_ty
 702
 703     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
 704         out_java_enum = "package org.ldk.enums;\n\n"
 705         out_java = ""
 706         out_c = ""
 707         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
 708         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
 709         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 710         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 711         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
 712         out_c += "\t}\n"
 713         out_c += "\tswitch (ord) {\n"
 714
 715         if enum_doc_comment is not None:
 716             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 717         out_java_enum += "public enum " + struct_name + " {\n"
 718         ord_v = 0
 719         for var, var_docs in variants:
 720             if var_docs is not None:
 721                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
 722             out_java_enum += "\t" + var + ",\n"
 723             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
 724             ord_v = ord_v + 1
 725         out_java_enum = out_java_enum + "\t; static native void init();\n"
 726         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
 727         out_java_enum = out_java_enum + "}"
 728         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
 729         out_c += "\t}\n"
 730         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
 731         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
 732         out_c += "}\n"
 733
 734         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
 735         for var, _ in variants:
 736             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
 737         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"
 738         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
 739         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
 740         for var, _ in variants:
 741             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
 742             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
 743         out_c = out_c + "}\n"
 744         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
 745         out_c = out_c + "\tswitch (val) {\n"
 746         ord_v = 0
 747         for var, _ in variants:
 748             out_c = out_c + "\t\tcase " + var + ":\n"
 749             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
 750             ord_v = ord_v + 1
 751         out_c = out_c + "\t\tdefault: abort();\n"
 752         out_c = out_c + "\t}\n"
 753         out_c = out_c + "}\n\n"
 754
 755         return (out_c, out_java_enum, out_java)
 756
 757     def c_unitary_enum_to_native_call(self, ty_info):
 758         return (ty_info.rust_obj + "_to_java(env, ", ")")
 759     def native_unitary_enum_to_c_call(self, ty_info):
 760         return (ty_info.rust_obj + "_from_java(env, ", ")")
 761
 762     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
 763         out_c = ""
 764         for var in variants:
 765             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
 766             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
 767         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"
 768         for var_name in variants:
 769             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
 770             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
 771             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
 772             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"
 773             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
 774         out_c = out_c + "}\n"
 775         return out_c
 776
 777     def c_complex_enum_pass_ty(self, struct_name):
 778         return "jobject"
 779
 780     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
 781         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
 782         for param in c_params:
 783             ret = ret + ", " + param
 784         return ret + ")"
 785
 786     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
 787         out_java_trait = ""
 788         out_java = ""
 789
 790         # First generate most of the Java code, note that we need information about java method argument strings for C
 791         out_java_trait = out_java_trait + self.hu_struct_file_prefix
 792         if trait_doc_comment is not None:
 793             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
 794         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 795         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
 796         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
 797         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
 798         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
 799         for var in flattened_field_vars:
 800             if isinstance(var, ConvInfo):
 801                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
 802             else:
 803                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
 804         out_java_trait = out_java_trait + ") {\n"
 805         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
 806         for var in flattened_field_vars:
 807             if isinstance(var, ConvInfo):
 808                 if var.from_hu_conv is not None:
 809                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
 810                 else:
 811                     out_java_trait = out_java_trait + ", " + var.arg_name
 812             else:
 813                 out_java_trait = out_java_trait + ", " + var[1]
 814         out_java_trait = out_java_trait + "));\n"
 815         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
 816         for var in flattened_field_vars:
 817             if isinstance(var, ConvInfo):
 818                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
 819                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
 820             else:
 821                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
 822         out_java_trait += f"""          this.bindings_instance = arg;
 823         }}
 824         @Override @SuppressWarnings("deprecation")
 825         protected void finalize() throws Throwable {{
 826                 if (ptr != 0) {{ bindings.{struct_name.replace("LDK","")}_free(ptr); }} super.finalize();
 827         }}
 828         /**
 829          * Destroys the object, freeing associated resources. After this call, any access
 830          * to this object may result in a SEGFAULT or worse.
 831          *
 832          * You should generally NEVER call this method. You should let the garbage collector
 833          * do this for you when it finalizes objects. However, it may be useful for types
 834          * which represent locks and should be closed immediately to avoid holding locks
 835          * until the GC runs.
 836          */
 837         public void destroy() {{
 838                 if (ptr != 0) {{ bindings.{struct_name.replace("LDK","")}_free(ptr); }}
 839                 ptr = 0;
 840         }}
 841 """
 842
 843         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
 844         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
 845         for var in flattened_field_vars:
 846             if isinstance(var, ConvInfo):
 847                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
 848             else:
 849                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
 850                 # Java-implemented version, so we require users pass a Java implementation here :/
 851                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
 852         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
 853         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
 854         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
 855         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
 856         java_meths = []
 857         for fn_line in field_fns:
 858             java_meth_descr = "("
 859             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 860                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 861                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 862                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
 863                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 864
 865                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
 866                     if idx >= 1:
 867                         out_java = out_java + ", "
 868                         java_trait_constr = java_trait_constr + ", "
 869                         out_java_trait = out_java_trait + ", "
 870                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 871                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
 872                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 873                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
 874                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
 875                 java_meths.append((fn_line.fn_name, java_meth_descr))
 876
 877                 out_java = out_java + ");\n"
 878                 out_java_trait = out_java_trait + ");\n"
 879                 java_trait_constr = java_trait_constr + ") {\n"
 880
 881                 for arg_info in fn_line.args_ty:
 882                     if arg_info.to_hu_conv is not None:
 883                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
 884
 885                 if fn_line.ret_ty_info.java_ty != "void":
 886                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
 887                 else:
 888                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
 889
 890                 for idx, arg_info in enumerate(fn_line.args_ty):
 891                     if idx != 0:
 892                         java_trait_constr = java_trait_constr + ", "
 893                     if arg_info.to_hu_conv_name is not None:
 894                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
 895                     else:
 896                         java_trait_constr = java_trait_constr + arg_info.arg_name
 897
 898                 java_trait_constr += ");\n"
 899                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
 900                 if fn_line.ret_ty_info.java_ty != "void":
 901                     if fn_line.ret_ty_info.from_hu_conv is not None:
 902                         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"
 903                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
 904                             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"
 905                         #if fn_line.ret_ty_info.rust_obj in result_types:
 906                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
 907                     else:
 908                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
 909                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
 910         java_trait_constr = java_trait_constr + "\t\t}"
 911         for var in field_vars:
 912             if isinstance(var, ConvInfo):
 913                 java_trait_constr = java_trait_constr + ", " + var.arg_name
 914             else:
 915                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
 916                 suptrait_constr = ""
 917                 for suparg in var[2]:
 918                     if isinstance(suparg, ConvInfo):
 919                         suptrait_constr += ", " + suparg.arg_name
 920                     else:
 921                         suptrait_constr += ", " + suparg[1] + "_impl"
 922                 java_trait_constr += suptrait_constr + ").bindings_instance"
 923                 for suparg in var[2]:
 924                     if isinstance(suparg, ConvInfo):
 925                         java_trait_constr += ", " + suparg.arg_name
 926                     else:
 927                         java_trait_constr += ", " + suparg[1] + ".new_impl("
 928                         # Blindly assume that we can just strip the first arg to build the args for the supertrait
 929                         java_trait_constr += suptrait_constr.split(", ", 1)[1]
 930                         java_trait_constr += ").bindings_instance"
 931         out_java_trait = out_java_trait + "\t}\n"
 932         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 933
 934         out_java = out_java + "\t}\n"
 935
 936         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
 937         for var in flattened_field_vars:
 938             if isinstance(var, ConvInfo):
 939                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
 940             else:
 941                 out_java = out_java + ", " + var[0] + " " + var[1]
 942         out_java = out_java + ");\n"
 943
 944         # Now that we've written out our java code (and created java_meths), generate C
 945         out_c = "typedef struct " + struct_name + "_JCalls {\n"
 946         out_c = out_c + "\tatomic_size_t refcnt;\n"
 947         out_c = out_c + "\tJavaVM *vm;\n"
 948         out_c = out_c + "\tjweak o;\n"
 949         for var in flattened_field_vars:
 950             if isinstance(var, ConvInfo):
 951                 # We're a regular ol' field
 952                 pass
 953             else:
 954                 # We're a supertrait
 955                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
 956         for fn in field_fns:
 957             if fn.fn_name != "free" and fn.fn_name != "cloned":
 958                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
 959         out_c = out_c + "} " + struct_name + "_JCalls;\n"
 960
 961         for fn_line in field_fns:
 962             if fn_line.fn_name == "free":
 963                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
 964                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 965                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
 966                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 967                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
 968                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 969                 out_c = out_c + "\t\tFREE(j_calls);\n"
 970                 out_c = out_c + "\t}\n}\n"
 971
 972         for idx, fn_line in enumerate(field_fns):
 973             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 974                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
 975                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
 976                 if fn_line.self_is_const:
 977                     out_c = out_c + "const void* this_arg"
 978                 else:
 979                     out_c = out_c + "void* this_arg"
 980
 981                 for idx, arg in enumerate(fn_line.args_ty):
 982                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
 983
 984                 out_c = out_c + ") {\n"
 985                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 986                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 987
 988                 for arg_info in fn_line.args_ty:
 989                     if arg_info.ret_conv is not None:
 990                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
 991                         out_c = out_c + arg_info.arg_name
 992                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
 993
 994                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
 995                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
 996                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 997                 elif fn_line.ret_ty_info.c_ty == "void":
 998                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 999                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
1000                     # Manually write out String methods as they're just an Object
1001                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1002                 elif not fn_line.ret_ty_info.passed_as_ptr:
1003                     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"
1004                 else:
1005                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1006
1007                 for idx, arg_info in enumerate(fn_line.args_ty):
1008                     if arg_info.ret_conv is not None:
1009                         out_c = out_c + ", " + arg_info.ret_conv_name
1010                     else:
1011                         out_c = out_c + ", " + arg_info.arg_name
1012                 out_c = out_c + ");\n"
1013
1014                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
1015                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
1016                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
1017                 out_c += "\t}\n"
1018
1019                 if fn_line.ret_ty_info.arg_conv is not None:
1020                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
1021                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1022                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
1023                 else:
1024                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1025                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
1026                         out_c += "\treturn ret;\n"
1027
1028                 out_c = out_c + "}\n"
1029
1030         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
1031         can_clone_with_ptr = True
1032         for var in field_vars:
1033             if isinstance(var, ConvInfo):
1034                 can_clone_with_ptr = False
1035         if can_clone_with_ptr:
1036             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
1037             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
1038             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
1039             for var in flattened_field_vars:
1040                 if not isinstance(var, ConvInfo):
1041                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[2].replace(".", "->") + "->refcnt, 1, memory_order_release);\n"
1042             out_c = out_c + "}\n"
1043
1044         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
1045         for var in flattened_field_vars:
1046             if isinstance(var, ConvInfo):
1047                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1048             else:
1049                 out_c = out_c + ", jobject " + var[1]
1050         out_c = out_c + ") {\n"
1051
1052         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
1053         out_c = out_c + "\tCHECK(c != NULL);\n"
1054         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
1055         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
1056         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
1057         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
1058
1059         for (fn_name, java_meth_descr) in java_meths:
1060             if fn_name != "free" and fn_name != "cloned":
1061                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
1062                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
1063
1064         for var in flattened_field_vars:
1065             if isinstance(var, ConvInfo) and var.arg_conv is not None:
1066                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
1067         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
1068         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
1069         for fn_line in field_fns:
1070             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1071                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1072             elif fn_line.fn_name == "free":
1073                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1074             else:
1075                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1076         for var in field_vars:
1077             if isinstance(var, ConvInfo):
1078                 if var.arg_conv_name is not None:
1079                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1080                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1081                 else:
1082                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1083                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1084             else:
1085                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1086                 for suparg in var[2]:
1087                     if isinstance(suparg, ConvInfo):
1088                         out_c = out_c + ", " + suparg.arg_name
1089                     else:
1090                         out_c = out_c + ", " + suparg[1]
1091                 out_c += "),\n"
1092         out_c = out_c + "\t};\n"
1093         for var in flattened_field_vars:
1094             if not isinstance(var, ConvInfo):
1095                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[2] + ".this_arg;\n"
1096         out_c = out_c + "\treturn ret;\n"
1097         out_c = out_c + "}\n"
1098
1099         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1100         for var in flattened_field_vars:
1101             if isinstance(var, ConvInfo):
1102                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1103             else:
1104                 out_c = out_c + ", jobject " + var[1]
1105         out_c = out_c + ") {\n"
1106         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1107         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1108         for var in flattened_field_vars:
1109             if isinstance(var, ConvInfo):
1110                 out_c = out_c + ", " + var.arg_name
1111             else:
1112                 out_c = out_c + ", " + var[1]
1113         out_c = out_c + ");\n"
1114         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1115         out_c = out_c + "}\n"
1116
1117         for var in flattened_field_vars:
1118             if not isinstance(var, ConvInfo):
1119                 out_java_trait += "\n\t/**\n"
1120                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1121                 out_java_trait += "\t */\n"
1122                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1123                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1124                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1125                 out_java_trait += "\t\tres.ptrs_to.add(this);\n"
1126                 out_java_trait += "\t\treturn res;\n"
1127                 out_java_trait += "\t}\n"
1128                 out_java_trait += "\n"
1129
1130                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1131
1132                 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"
1133                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1134                 out_c += "\treturn tag_ptr(&inp->" + var[2] + ", false);\n"
1135                 out_c += "}\n"
1136
1137         return (out_java, out_java_trait, out_c)
1138
1139     def trait_struct_inc_refcnt(self, ty_info):
1140         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1141         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1142         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1143         return base_conv
1144
1145     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1146         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1147         out_java_enum = ""
1148         out_java = ""
1149         out_c = ""
1150
1151         out_java_enum += (self.hu_struct_file_prefix)
1152         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1153         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1154         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1155         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1156         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1157         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1158         out_java_enum += ("\t\tsuper.finalize();\n")
1159         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1160         out_java_enum += ("\t}\n")
1161         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1162         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1163         java_hu_subclasses = ""
1164
1165         init_meth_jty_strs = {}
1166
1167         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1168         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1169         for var in variant_list:
1170             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1171             if var.var_docs is not None:
1172                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1173             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1174             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1175             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1176             init_meth_jty_str = ""
1177             init_meth_params = ""
1178             init_meth_body = ""
1179             hu_conv_body = ""
1180             for idx, (field_ty, field_docs) in enumerate(var.fields):
1181                 if idx > 0:
1182                     init_meth_params = init_meth_params + ", "
1183
1184                 java_ty = field_ty.java_ty
1185                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1186                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1187                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1188                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1189                 if field_docs is not None:
1190                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1191                 java_hu_subclasses += "\t\t"
1192                 if field_ty.nullable:
1193                     java_hu_subclasses += "@Nullable "
1194                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1195                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1196
1197                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1198                 if field_ty.to_hu_conv is not None:
1199                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1200                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1201                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1202                 else:
1203                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1204                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1205             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1206             out_java +=  (init_meth_body)
1207             out_java +=  ("}\n")
1208             out_java += ("\t\t}\n")
1209             out_java_enum += ("\t\t}\n")
1210             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"
1211             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1212             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1213             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1214         out_java += ("\t\tstatic native void init();\n")
1215         out_java += ("\t}\n")
1216         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1217         out_java_enum += (java_hu_subclasses)
1218         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1219         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1220
1221         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1222
1223         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")
1224         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1225         out_c += ("\tswitch(obj->tag) {\n")
1226         for var in variant_list:
1227             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1228             c_params = []
1229             for idx, (field_map, field_docs) in enumerate(var.fields):
1230                 if field_map.ret_conv is not None:
1231                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1232                     if var.tuple_variant:
1233                         out_c += "obj->" + camel_to_snake(var.var_name)
1234                     else:
1235                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1236                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1237                     c_params.append(field_map.ret_conv_name)
1238                 else:
1239                     if var.tuple_variant:
1240                         c_params.append("obj->" + camel_to_snake(var.var_name))
1241                     else:
1242                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1243             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1244             out_c += ("\t\t}\n")
1245         out_c += ("\t\tdefault: abort();\n")
1246         out_c += ("\t}\n}\n")
1247         return (out_java, out_java_enum, out_c)
1248
1249     def map_opaque_struct(self, struct_name, struct_doc_comment):
1250         out_opaque_struct_human = ""
1251         out_opaque_struct_human += self.hu_struct_file_prefix
1252         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1253         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1254         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1255         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1256         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1257             out_opaque_struct_human += (" implements AutoCloseable")
1258         out_opaque_struct_human += (" {\n")
1259         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1260         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1261             out_opaque_struct_human += ("\t@Override public void close() {\n")
1262         else:
1263             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1264             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1265             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1266         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1267         out_opaque_struct_human += ("\t}\n\n")
1268         return out_opaque_struct_human
1269
1270     def map_tuple(self, struct_name):
1271         return self.map_opaque_struct(struct_name, "A Tuple")
1272
1273     def map_result(self, struct_name, res_map, err_map):
1274         human_ty = struct_name.replace("LDKCResult", "Result")
1275         java_hu_struct = ""
1276         java_hu_struct += self.hu_struct_file_prefix
1277         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1278         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1279         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1280         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1281         java_hu_struct += "\t}\n\n"
1282         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1283         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1284         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1285         java_hu_struct += "\t\t} else {\n"
1286         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1287         java_hu_struct += "\t\t}\n"
1288         java_hu_struct += "\t}\n"
1289
1290         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1291
1292         if res_map.java_hu_ty != "void":
1293             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1294         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1295         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1296         if res_map.java_hu_ty == "void":
1297             pass
1298         elif res_map.to_hu_conv is not None:
1299             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1300             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1301             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1302         else:
1303             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1304         java_hu_struct += "\t\t}\n"
1305         java_hu_struct += "\t}\n\n"
1306
1307         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1308         if err_map.java_hu_ty != "void":
1309             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1310         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1311         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1312         if err_map.java_hu_ty == "void":
1313             pass
1314         elif err_map.to_hu_conv is not None:
1315             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1316             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1317             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1318         else:
1319             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1320         java_hu_struct += "\t\t}\n"
1321
1322         java_hu_struct += "\t}\n\n"
1323         return java_hu_struct
1324
1325     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):
1326         out_java = ""
1327         out_c = ""
1328         out_java_struct = None
1329
1330         out_java += ("\tpublic static native ")
1331         out_c += (self.c_fn_ty_pfx)
1332         out_c += (return_type_info.c_ty)
1333         out_java += (return_type_info.java_ty)
1334         if return_type_info.ret_conv is not None:
1335             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1336         out_java += (" " + method_name + "(")
1337         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1338         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1339
1340         for idx, arg_conv_info in enumerate(argument_types):
1341             if idx != 0:
1342                 out_java += (", ")
1343                 out_c += (", ")
1344             if arg_conv_info.c_ty != "void":
1345                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1346                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1347
1348         out_java_struct = ""
1349         extra_java_struct_out = ""
1350         if not args_known:
1351             out_java_struct += ("\t// Skipped " + method_name + "\n")
1352         else:
1353             if doc_comment is not None:
1354                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1355             if return_type_info.nullable:
1356                 out_java_struct += "\t@Nullable\n"
1357             if not takes_self:
1358                 if meth_n == "new":
1359                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1360                 elif meth_n == "default":
1361                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1362                 else:
1363                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1364             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1365                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1366             else:
1367                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1368                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1369                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1370                     extra_java_struct_out += "\t}\n"
1371                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1372                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1373                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1374                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1375                     extra_java_struct_out += "\t}\n"
1376                 if meth_n == "wait":
1377                     meth_n = "wait_indefinite"
1378                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1379             for idx, arg in enumerate(argument_types):
1380                 if idx != 0:
1381                     if not takes_self or idx > 1:
1382                         out_java_struct += ", "
1383                 elif takes_self:
1384                     continue
1385                 if arg.java_ty != "void":
1386                     if arg.arg_name in default_constructor_args:
1387                         assert not arg.nullable
1388                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1389                             if explode_idx != 0:
1390                                 out_java_struct += (", ")
1391                             out_java_struct += (
1392                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1393                     else:
1394                         if arg.nullable:
1395                             out_java_struct += "@Nullable "
1396                         ty_string = self.fully_qualified_hu_ty_path(arg)
1397                         out_java_struct += ty_string + " " + arg.arg_name
1398         out_java += (");\n")
1399         out_c += (") {\n")
1400         if out_java_struct is not None:
1401             out_java_struct += (") {\n")
1402         for info in argument_types:
1403             if info.arg_conv is not None:
1404                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1405         if return_type_info.ret_conv is not None:
1406             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1407         elif return_type_info.c_ty != "void":
1408             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1409         else:
1410             out_c += ("\t")
1411         if c_call_string is None:
1412             out_c += (method_name + "(")
1413         else:
1414             out_c += (c_call_string)
1415         for idx, info in enumerate(argument_types):
1416             if info.arg_conv_name is not None:
1417                 if idx != 0:
1418                     out_c += (", ")
1419                 elif c_call_string is not None:
1420                     continue
1421                 out_c += (info.arg_conv_name)
1422         out_c += (")")
1423         if return_type_info.ret_conv is not None:
1424             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1425         else:
1426             out_c += (";")
1427         for info in argument_types:
1428             if info.arg_conv_cleanup is not None:
1429                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1430         if return_type_info.ret_conv is not None:
1431             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1432         elif return_type_info.c_ty != "void":
1433             out_c += ("\n\treturn ret_val;")
1434         out_c += ("\n}\n\n")
1435
1436         if args_known:
1437             out_java_struct += ("\t\t")
1438             if return_type_info.java_ty != "void":
1439                 out_java_struct += (return_type_info.java_ty + " ret = ")
1440             out_java_struct += ("bindings." + method_name + "(")
1441             for idx, info in enumerate(argument_types):
1442                 if idx != 0:
1443                     out_java_struct += (", ")
1444                 if idx == 0 and takes_self:
1445                     out_java_struct += ("this.ptr")
1446                 elif info.arg_name in default_constructor_args:
1447                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1448                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1449                         if explode_idx != 0:
1450                             out_java_struct += (", ")
1451                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1452                         if explode_arg.from_hu_conv is not None:
1453                             out_java_struct += (
1454                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1455                         else:
1456                             out_java_struct += (expl_arg_name)
1457                     out_java_struct += (")")
1458                 elif info.from_hu_conv is not None:
1459                     out_java_struct += (info.from_hu_conv[0])
1460                 else:
1461                     out_java_struct += (info.arg_name)
1462             out_java_struct += (");\n")
1463
1464             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1465             # the stack, calling its finalizer immediately even if member methods are *actively
1466             # executing* on the same object, as long as said object is on the stack. There is no
1467             # concrete specification for when the optimizer is allowed to do this, and when it is
1468             # not, so there is absolutely no way to be certain that this fix suffices.
1469             #
1470             # Instead, the "Java Language Specification" says only that an object is reachable
1471             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1472             # computation from any live thread". To any sensible reader this would mean actively
1473             # executing a member function on an object would make it not eligible for finalization.
1474             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1475             # very explicitly in fact, but those are just, like, words, man.
1476             #
1477             # In the seemingly non-normative text further down, a few examples of things the
1478             # optimizer can do are given, including "if the values in an object's fields are
1479             # stored in registers[, t]he may then access the registers instead of the object, and
1480             # never access the object again[, implying] that the object is garbage". This appears
1481             # to fully contradict both the above statement, the API documentation in java.lang.ref
1482             # regarding when a reference is "strongly reachable", and basic common sense. There is
1483             # no concrete set of limitations stated, however, seemingly implying the JIT could
1484             # decide your code would run faster by simply garbage collecting everything
1485             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1486             # entirely flying blind here. We add some fences and hope that its sufficient, but
1487             # with no specification to rely on, we cannot be certain of anything.
1488             #
1489             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1490             # object will be considered available for garbage collection once the JIT kicks in, so
1491             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1492             for idx, info in enumerate(argument_types):
1493                 if idx == 0 and takes_self:
1494                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1495                 elif info.arg_name in default_constructor_args:
1496                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1497                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1498                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1499                 elif info.c_ty != "void":
1500                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1501
1502             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1503                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1504
1505             if return_type_info.to_hu_conv is not None:
1506                 if not takes_self:
1507                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1508                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1509                 else:
1510                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1511
1512             for idx, info in enumerate(argument_types):
1513                 if idx == 0 and takes_self:
1514                     pass
1515                 elif info.arg_name in default_constructor_args:
1516                     for explode_arg in default_constructor_args[info.arg_name]:
1517                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1518                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1519                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1520                                                                                                expl_arg_name).replace(
1521                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1522                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1523                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1524                         out_java_struct += (
1525                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1526                     else:
1527                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1528
1529             if takes_self and not takes_self_as_ref:
1530                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1531             if return_type_info.to_hu_conv_name is not None:
1532                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1533             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1534                 out_java_struct += ("\t\treturn ret;\n")
1535             out_java_struct += ("\t}\n\n")
1536
1537         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1538
1539     def cleanup(self):
1540         pass