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

   1 from bindingstypes import *
   2 from enum import Enum
   3 import sys
   4
   5 class Target(Enum):
   6     JAVA = 1,
   7     ANDROID = 2
   8
   9 class Consts:
  10     def __init__(self, DEBUG: bool, target: Target, **kwargs):
  11         self.target = target
  12         self.c_array_class_caches = set()
  13         self.c_type_map = dict(
  14             bool = ['boolean'],
  15             uint8_t = ['byte'],
  16             uint16_t = ['short'],
  17             uint32_t = ['int'],
  18             uint64_t = ['long'],
  19         )
  20         self.java_type_map = dict(
  21             String = "String"
  22         )
  23         self.java_hu_type_map = dict(
  24             String = "String"
  25         )
  26
  27         self.to_hu_conv_templates = dict(
  28             ptr = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }',
  29             default = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }'
  30         )
  31
  32         self.bindings_header = """package org.ldk.impl;
  33 import org.ldk.enums.*;
  34 import org.ldk.impl.version;
  35 import java.io.File;
  36 import java.io.InputStream;
  37 import java.io.IOException;
  38 import java.nio.file.Files;
  39 import java.nio.file.Path;
  40 import java.nio.file.StandardCopyOption;
  41
  42 public class bindings {
  43         static {
  44                 try {
  45                         // Try to load natively first, this works on Android and in testing.
  46                         System.loadLibrary(\"lightningjni\");
  47                 } catch (UnsatisfiedLinkError system_load_err) {
  48                         // Otherwise try to load from the library jar.
  49                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
  50                         tmpdir.mkdir(); // If it fails to create, assume it was there already
  51                         tmpdir.deleteOnExit();
  52                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
  53                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
  54                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
  55                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
  56                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
  57                                 Runtime.getRuntime().load(libpath.toString());
  58                         } catch (Exception e) {
  59                                 System.err.println("Failed to load LDK native library.");
  60                                 System.err.println("System LDK native library load failed with: " + system_load_err);
  61                                 System.err.println("Resource-based LDK native library load failed with: " + e);
  62                                 throw new IllegalArgumentException(e);
  63                         }
  64                 }
  65                 init(java.lang.Enum.class);
  66                 init_class_cache();
  67                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
  68                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
  69                 // Fetching the LDK versions from C also checks that the header and binaries match
  70                 System.err.println("Loaded LDK-Java Bindings " + version.get_ldk_java_bindings_version() + " with LDK " + get_ldk_version() + " and LDK-C-Bindings " + get_ldk_c_bindings_version());
  71         }
  72         static native void init(java.lang.Class c);
  73         static native void init_class_cache();
  74         static native String get_lib_version_string();
  75
  76         public static native String get_ldk_c_bindings_version();
  77         public static native String get_ldk_version();
  78
  79 """
  80         self.bindings_version_file = """package org.ldk.impl;
  81
  82 public class version {
  83         public static String get_ldk_java_bindings_version() {
  84                 return "<git_version_ldk_garbagecollected>";
  85         }
  86 }"""
  87
  88         self.util_fn_pfx = """package org.ldk.structs;
  89 import org.ldk.impl.bindings;
  90 import org.ldk.enums.*;
  91 import org.ldk.util.*;
  92 import java.util.Arrays;
  93 import java.lang.ref.Reference;
  94 import javax.annotation.Nullable;
  95
  96 public class UtilMethods {
  97 """
  98         self.util_fn_sfx = "}"
  99         self.common_base = """package org.ldk.structs;
 100 import java.util.LinkedList;
 101 class CommonBase {
 102         long ptr;
 103         LinkedList<Object> ptrs_to = new LinkedList();
 104         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
 105 }
 106 """
 107
 108         self.txout_defn = """public class TxOut extends CommonBase {
 109         /** The script_pubkey in this output */
 110         public final byte[] script_pubkey;
 111         /** The value, in satoshis, of this output */
 112         public final long value;
 113
 114         TxOut(java.lang.Object _dummy, long ptr) {
 115                 super(ptr);
 116                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 117                 this.value = bindings.TxOut_get_value(ptr);
 118         }
 119         public TxOut(long value, byte[] script_pubkey) {
 120                 super(bindings.TxOut_new(script_pubkey, value));
 121                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
 122                 this.value = bindings.TxOut_get_value(ptr);
 123         }
 124
 125         @Override @SuppressWarnings(\"deprecation\")
 126         protected void finalize() throws Throwable {
 127                 super.finalize();
 128                 if (ptr != 0) { bindings.TxOut_free(ptr); }
 129         }
 130 }"""
 131
 132         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
 133         /** The bytes of the scalar value, in big endian */
 134         public final byte[] scalar_bytes;
 135
 136         BigEndianScalar(java.lang.Object _dummy, long ptr) {
 137                 super(ptr);
 138                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 139         }
 140         public BigEndianScalar(byte[] scalar_bytes) {
 141                 super(bindings.BigEndianScalar_new(scalar_bytes));
 142                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
 143         }
 144
 145         @Override @SuppressWarnings(\"deprecation\")
 146         protected void finalize() throws Throwable {
 147                 super.finalize();
 148                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
 149         }
 150 }"""
 151
 152
 153         self.c_file_pfx = """#include <jni.h>
 154 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
 155 #define int64_t jlong
 156 #include \"org_ldk_impl_bindings.h\"
 157 #include <lightning.h>
 158 #include <string.h>
 159 #include <stdatomic.h>
 160 #include <stdlib.h>
 161
 162 #define LIKELY(v) __builtin_expect(!!(v), 1)
 163 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
 164
 165 """
 166
 167         if self.target == Target.ANDROID:
 168             self.c_file_pfx = self.c_file_pfx + """
 169 #include <android/log.h>
 170 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
 171
 172 #include <unistd.h>
 173 #include <pthread.h>
 174 static void* redirect_stderr(void* ignored) {
 175         int pipes[2];
 176         pipe(pipes);
 177         dup2(pipes[1], STDERR_FILENO);
 178         char buf[8192];
 179         memset(buf, 0, 8192);
 180         ssize_t len;
 181         while ((len = read(pipes[0], buf, 8191)) > 0) {
 182                 DEBUG_PRINT("%s\\n", buf);
 183                 memset(buf, 0, 8192);
 184         }
 185         DEBUG_PRINT("End of stderr???\\n");
 186         return 0;
 187 }
 188 void __attribute__((constructor)) spawn_stderr_redirection() {
 189         pthread_t thread;
 190         pthread_create(&thread, NULL, &redirect_stderr, NULL);
 191 }
 192 """
 193         else:
 194             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
 195
 196         if not DEBUG or sys.platform == "darwin":
 197             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
 198 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
 199 #define CHECK_ACCESS(p)
 200 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
 201 """
 202         if not DEBUG:
 203             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
 204 #define CHECK(a)
 205 """
 206         if DEBUG:
 207             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
 208 // Always run a, then assert it is true:
 209 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 210 // Assert a is true or do nothing
 211 #define CHECK(a) DO_ASSERT(a)
 212
 213 void __attribute__((constructor)) debug_log_version() {
 214         if (check_get_ldk_version() == NULL)
 215                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
 216         if (check_get_ldk_bindings_version() == NULL)
 217                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
 218 }
 219 """
 220
 221             if sys.platform != "darwin":
 222                 self.c_file_pfx += """
 223 // Running a leak check across all the allocations and frees of the JDK is a mess,
 224 // so instead we implement our own naive leak checker here, relying on the -wrap
 225 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
 226 // and free'd in Rust or C across the generated bindings shared library.
 227 #include <threads.h>
 228 """
 229
 230                 if self.target == Target.ANDROID:
 231                     self.c_file_pfx = self.c_file_pfx + """
 232 #include <unwind.h>
 233 #include <dlfcn.h>
 234
 235 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
 236 // symbols, so we only use it on Android, where execinfo.h is unavailable.
 237
 238 struct BacktraceState {
 239         void** current;
 240         void** end;
 241 };
 242 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
 243         struct BacktraceState* state = (struct BacktraceState*)arg;
 244         uintptr_t pc = _Unwind_GetIP(context);
 245         if (pc) {
 246                 if (state->current == state->end) {
 247                         return _URC_END_OF_STACK;
 248                 } else {
 249                         *state->current++ = (void*)(pc);
 250                 }
 251         }
 252         return _URC_NO_REASON;
 253 }
 254
 255 int backtrace(void** buffer, int max) {
 256         struct BacktraceState state = { buffer, buffer + max };
 257         _Unwind_Backtrace(unwind_callback, &state);
 258         return state.current - buffer;
 259 }
 260
 261 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
 262         for (int idx = 0; idx < count; ++idx) {
 263                 Dl_info info;
 264                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
 265                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
 266                 } else {
 267                         DEBUG_PRINT("%p: ???", buffer[idx]);
 268                 }
 269         }
 270 }
 271 """
 272                 else:
 273                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
 274                 self.c_file_pfx = self.c_file_pfx + """
 275 #include <unistd.h>
 276 #include <pthread.h>
 277 static pthread_mutex_t allocation_mtx;
 278
 279 void __attribute__((constructor)) init_mtx() {
 280         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
 281 }
 282
 283 #define BT_MAX 128
 284 typedef struct allocation {
 285         struct allocation* next;
 286         void* ptr;
 287         const char* struct_name;
 288         void* bt[BT_MAX];
 289         int bt_len;
 290         unsigned long alloc_len;
 291 } allocation;
 292 static allocation* allocation_ll = NULL;
 293
 294 void* __real_malloc(size_t len);
 295 void* __real_calloc(size_t nmemb, size_t len);
 296 static void new_allocation(void* res, const char* struct_name, size_t len) {
 297         allocation* new_alloc = __real_malloc(sizeof(allocation));
 298         new_alloc->ptr = res;
 299         new_alloc->struct_name = struct_name;
 300         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
 301         new_alloc->alloc_len = len;
 302         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 303         new_alloc->next = allocation_ll;
 304         allocation_ll = new_alloc;
 305         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 306 }
 307 static void* MALLOC(size_t len, const char* struct_name) {
 308         void* res = __real_malloc(len);
 309         new_allocation(res, struct_name, len);
 310         return res;
 311 }
 312 void __real_free(void* ptr);
 313 static void alloc_freed(void* ptr) {
 314         allocation* p = NULL;
 315         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 316         allocation* it = allocation_ll;
 317         while (it->ptr != ptr) {
 318                 p = it; it = it->next;
 319                 if (it == NULL) {
 320                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
 321                         void* bt[BT_MAX];
 322                         int bt_len = backtrace(bt, BT_MAX);
 323                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 324                         DEBUG_PRINT("\\n\\n");
 325                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 326                         return; // addrsan should catch malloc-unknown and print more info than we have
 327                 }
 328         }
 329         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
 330         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 331         DO_ASSERT(it->ptr == ptr);
 332         __real_free(it);
 333 }
 334 static void FREE(void* ptr) {
 335         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
 336         alloc_freed(ptr);
 337         __real_free(ptr);
 338 }
 339
 340 void* __wrap_malloc(size_t len) {
 341         void* res = __real_malloc(len);
 342         new_allocation(res, "malloc call", len);
 343         return res;
 344 }
 345 void* __wrap_calloc(size_t nmemb, size_t len) {
 346         void* res = __real_calloc(nmemb, len);
 347         new_allocation(res, "calloc call", len);
 348         return res;
 349 }
 350 void __wrap_free(void* ptr) {
 351         if (ptr == NULL) return;
 352         alloc_freed(ptr);
 353         __real_free(ptr);
 354 }
 355
 356 static void CHECK_ACCESS(const void* ptr) {
 357         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
 358         allocation* it = allocation_ll;
 359         while (it->ptr != ptr) {
 360                 it = it->next;
 361                 if (it == NULL) {
 362                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
 363                         void* bt[BT_MAX];
 364                         int bt_len = backtrace(bt, BT_MAX);
 365                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
 366                         DEBUG_PRINT("\\n\\n");
 367                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 368                         return; // addrsan should catch and print more info than we have
 369                 }
 370         }
 371         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
 372 }
 373 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
 374         if (v.is_owned && v.inner != NULL) { \\
 375                 const void *p = __unmangle_inner_ptr(v.inner); \\
 376                 if (p != NULL) { \\
 377                         CHECK_ACCESS(p); \\
 378                 } \\
 379         }
 380
 381 void* __real_realloc(void* ptr, size_t newlen);
 382 void* __wrap_realloc(void* ptr, size_t len) {
 383         if (ptr != NULL) alloc_freed(ptr);
 384         void* res = __real_realloc(ptr, len);
 385         new_allocation(res, "realloc call", len);
 386         return res;
 387 }
 388 void __wrap_reallocarray(void* ptr, size_t new_sz) {
 389         // Rust doesn't seem to use reallocarray currently
 390         DO_ASSERT(false);
 391 }
 392
 393 void __attribute__((destructor)) check_leaks() {
 394         unsigned long alloc_count = 0;
 395         unsigned long alloc_size = 0;
 396         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
 397         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 398         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 399         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
 400                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
 401                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
 402                 DEBUG_PRINT("\\n\\n");
 403                 alloc_count++;
 404                 alloc_size += a->alloc_len;
 405         }
 406         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
 407         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
 408         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
 409 }
 410 """
 411         self.c_file_pfx = self.c_file_pfx + """
 412 static jmethodID ordinal_meth = NULL;
 413 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
 414         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
 415         CHECK(ordinal_meth != NULL);
 416 }
 417
 418 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 419 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 420 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
 421 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
 422
 423 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
 424 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
 425 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
 426
 427 typedef jlongArray int64_tArray;
 428 typedef jbyteArray int8_tArray;
 429
 430 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
 431         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
 432         char* conv_buf = MALLOC(len + 1, "str conv buf");
 433         memcpy(conv_buf, chars, len);
 434         conv_buf[len] = 0;
 435         jstring ret = (*env)->NewStringUTF(env, conv_buf);
 436         FREE(conv_buf);
 437         return ret;
 438 }
 439 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
 440         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
 441         char* newchars = MALLOC(str_len + 1, "String chars");
 442         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
 443         memcpy(newchars, jchars, str_len);
 444         newchars[str_len] = 0;
 445         (*env)->ReleaseStringUTFChars(env, str, jchars);
 446         LDKStr res = {
 447                 .chars = newchars,
 448                 .len = str_len,
 449                 .chars_is_owned = true
 450         };
 451         return res;
 452 }
 453
 454 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
 455         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
 456 }
 457 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
 458         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
 459 }
 460 #include "version.c"
 461 """
 462         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
 463         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
 464 }"""
 465
 466         self.hu_struct_file_prefix = """package org.ldk.structs;
 467
 468 import org.ldk.impl.bindings;
 469 import org.ldk.enums.*;
 470 import org.ldk.util.*;
 471 import java.util.Arrays;
 472 import java.lang.ref.Reference;
 473 import javax.annotation.Nullable;
 474
 475 """
 476         self.hu_struct_file_suffix = ""
 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 bindings_footer(self):
 492         return "}\n"
 493
 494     def construct_jenv(self):
 495         res =  "JNIEnv *env;\n"
 496         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
 497         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
 498         if self.target == Target.ANDROID:
 499             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
 500         else:
 501             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
 502         res += "} else {\n"
 503         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
 504         res += "}\n"
 505         return res
 506     def deconstruct_jenv(self):
 507         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
 508         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
 509         res += "}\n"
 510         return res
 511
 512     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
 513         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 514             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
 515         return None
 516     def create_native_arr_call(self, arr_len, ty_info):
 517         if ty_info.c_ty == "int8_tArray":
 518             return "(*env)->NewByteArray(env, " + arr_len + ")"
 519         elif ty_info.subty.c_ty.endswith("Array"):
 520             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
 521             self.c_array_class_caches.add(clz_var)
 522             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
 523         else:
 524             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
 525     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
 526         if ty_info.c_ty == "int8_tArray":
 527             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
 528         else:
 529             assert False
 530     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
 531         if ty_info.c_ty == "int8_tArray":
 532             if copy:
 533                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
 534             else:
 535                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
 536         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
 537             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
 538         else:
 539             return None
 540     def get_native_arr_elem(self, arr_name, idxc, ty_info):
 541         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
 542             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
 543         else:
 544             assert False # Only called if above is None
 545     def get_native_arr_ptr_call(self, ty_info):
 546         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
 547             return None
 548         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
 549     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
 550         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
 551             return None
 552         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
 553     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
 554         if ty_info.c_ty == "int8_tArray":
 555             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
 556         else:
 557             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 558
 559     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
 560         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
 561             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 562         elif elem_ty.java_ty == "long":
 563             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
 564         elif elem_ty.java_hu_ty == "UInt5":
 565             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
 566         elif elem_ty.java_hu_ty == "WitnessVersion":
 567             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
 568         else:
 569             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
 570
 571     def str_ref_to_native_call(self, var_name, str_len):
 572         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
 573     def str_ref_to_c_call(self, var_name):
 574         return "java_to_owned_str(env, " + var_name + ")"
 575     def str_to_hu_conv(self, var_name):
 576         return None
 577     def str_from_hu_conv(self, var_name):
 578         return None
 579
 580     def c_fn_name_define_pfx(self, fn_name, has_args):
 581         if has_args:
 582             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
 583         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
 584
 585     def init_str(self):
 586         res = ""
 587         for ty in sorted(self.c_array_class_caches):
 588             res = res + "static jclass " + ty + "_clz = NULL;\n"
 589         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
 590         for ty in sorted(self.c_array_class_caches):
 591             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
 592             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
 593             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
 594         res = res + "}\n"
 595         return res
 596
 597     def var_decl_statement(self, ty_string, var_name, statement):
 598         return ty_string + " " + var_name + " = " + statement
 599
 600     def get_java_arr_len(self, arr_name):
 601         return arr_name + ".length"
 602     def get_java_arr_elem(self, elem_ty, arr_name, idx):
 603         return arr_name + "[" + idx + "]"
 604     def constr_hu_array(self, ty_info, arr_len):
 605         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
 606         conv = "new " + base_ty + "[" + arr_len + "]"
 607         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
 608             # Do a bit of a dance to move any excess [] to the end
 609             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
 610         return conv
 611     def cleanup_converted_native_array(self, ty_info, arr_name):
 612         return None
 613
 614     def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
 615         mapped_ty = arr_ty.subty
 616         if arr_ty.rust_obj == "LDKU128":
 617             return ("" + arr_name + ".getLEBytes()", "")
 618         if fixed_len is not None:
 619             return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
 620         return None
 621     def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
 622         if arr_ty.rust_obj == "LDKU128":
 623             return "org.ldk.util.UInt128 " + conv_name + " = new org.ldk.util.UInt128(" + arr_name + ");"
 624         return None
 625
 626     def java_arr_ty_str(self, elem_ty_str):
 627         return elem_ty_str + "[]"
 628
 629     def for_n_in_range(self, n, minimum, maximum):
 630         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
 631     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
 632         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
 633
 634     def get_ptr(self, var):
 635         return var + ".ptr"
 636     def set_null_skip_free(self, var):
 637         return var + ".ptr" + " = 0;"
 638
 639     def add_ref(self, holder, referent):
 640         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
 641
 642     def fully_qualified_hu_ty_path(self, ty):
 643         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
 644             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
 645         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt128" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
 646             return "org.ldk.util." + ty.java_hu_ty
 647         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
 648             return "org.ldk.structs." + ty.java_hu_ty
 649         return ty.java_hu_ty
 650
 651     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
 652         out_java_enum = "package org.ldk.enums;\n\n"
 653         out_java = ""
 654         out_c = ""
 655         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
 656         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
 657         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 658         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 659         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
 660         out_c += "\t}\n"
 661         out_c += "\tswitch (ord) {\n"
 662
 663         if enum_doc_comment is not None:
 664             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
 665         out_java_enum += "public enum " + struct_name + " {\n"
 666         ord_v = 0
 667         for var, var_docs in variants:
 668             if var_docs is not None:
 669                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
 670             out_java_enum += "\t" + var + ",\n"
 671             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
 672             ord_v = ord_v + 1
 673         out_java_enum = out_java_enum + "\t; static native void init();\n"
 674         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
 675         out_java_enum = out_java_enum + "}"
 676         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
 677         out_c += "\t}\n"
 678         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
 679         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
 680         out_c += "}\n"
 681
 682         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
 683         for var, _ in variants:
 684             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
 685         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"
 686         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
 687         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
 688         for var, _ in variants:
 689             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
 690             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
 691         out_c = out_c + "}\n"
 692         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
 693         out_c = out_c + "\tswitch (val) {\n"
 694         ord_v = 0
 695         for var, _ in variants:
 696             out_c = out_c + "\t\tcase " + var + ":\n"
 697             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
 698             ord_v = ord_v + 1
 699         out_c = out_c + "\t\tdefault: abort();\n"
 700         out_c = out_c + "\t}\n"
 701         out_c = out_c + "}\n\n"
 702
 703         return (out_c, out_java_enum, out_java)
 704
 705     def c_unitary_enum_to_native_call(self, ty_info):
 706         return (ty_info.rust_obj + "_to_java(env, ", ")")
 707     def native_unitary_enum_to_c_call(self, ty_info):
 708         return (ty_info.rust_obj + "_from_java(env, ", ")")
 709
 710     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
 711         out_c = ""
 712         for var in variants:
 713             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
 714             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
 715         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"
 716         for var_name in variants:
 717             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
 718             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
 719             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
 720             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"
 721             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
 722         out_c = out_c + "}\n"
 723         return out_c
 724
 725     def c_complex_enum_pass_ty(self, struct_name):
 726         return "jobject"
 727
 728     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
 729         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
 730         for param in c_params:
 731             ret = ret + ", " + param
 732         return ret + ")"
 733
 734     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
 735         out_java_trait = ""
 736         out_java = ""
 737
 738         # First generate most of the Java code, note that we need information about java method argument strings for C
 739         out_java_trait = out_java_trait + self.hu_struct_file_prefix
 740         if trait_doc_comment is not None:
 741             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
 742         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
 743         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
 744         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
 745         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
 746         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
 747         for var in flattened_field_vars:
 748             if isinstance(var, ConvInfo):
 749                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
 750             else:
 751                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
 752         out_java_trait = out_java_trait + ") {\n"
 753         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
 754         for var in flattened_field_vars:
 755             if isinstance(var, ConvInfo):
 756                 if var.from_hu_conv is not None:
 757                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
 758                 else:
 759                     out_java_trait = out_java_trait + ", " + var.arg_name
 760             else:
 761                 out_java_trait = out_java_trait + ", " + var[1]
 762         out_java_trait = out_java_trait + "));\n"
 763         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
 764         for var in flattened_field_vars:
 765             if isinstance(var, ConvInfo):
 766                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
 767                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
 768             else:
 769                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
 770         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
 771         out_java_trait = out_java_trait + "\t}\n"
 772         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
 773         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
 774         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
 775         out_java_trait = out_java_trait + "\t}\n\n"
 776
 777         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
 778         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
 779         for var in flattened_field_vars:
 780             if isinstance(var, ConvInfo):
 781                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
 782             else:
 783                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
 784                 # Java-implemented version, so we require users pass a Java implementation here :/
 785                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
 786         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
 787         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
 788         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
 789         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
 790         java_meths = []
 791         for fn_line in field_fns:
 792             java_meth_descr = "("
 793             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 794                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 795                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
 796                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
 797                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
 798
 799                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
 800                     if idx >= 1:
 801                         out_java = out_java + ", "
 802                         java_trait_constr = java_trait_constr + ", "
 803                         out_java_trait = out_java_trait + ", "
 804                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 805                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
 806                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
 807                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
 808                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
 809                 java_meths.append((fn_line.fn_name, java_meth_descr))
 810
 811                 out_java = out_java + ");\n"
 812                 out_java_trait = out_java_trait + ");\n"
 813                 java_trait_constr = java_trait_constr + ") {\n"
 814
 815                 for arg_info in fn_line.args_ty:
 816                     if arg_info.to_hu_conv is not None:
 817                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
 818
 819                 if fn_line.ret_ty_info.java_ty != "void":
 820                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
 821                 else:
 822                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
 823
 824                 for idx, arg_info in enumerate(fn_line.args_ty):
 825                     if idx != 0:
 826                         java_trait_constr = java_trait_constr + ", "
 827                     if arg_info.to_hu_conv_name is not None:
 828                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
 829                     else:
 830                         java_trait_constr = java_trait_constr + arg_info.arg_name
 831
 832                 java_trait_constr += ");\n"
 833                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
 834                 if fn_line.ret_ty_info.java_ty != "void":
 835                     if fn_line.ret_ty_info.from_hu_conv is not None:
 836                         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"
 837                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
 838                             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"
 839                         #if fn_line.ret_ty_info.rust_obj in result_types:
 840                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
 841                     else:
 842                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
 843                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
 844         java_trait_constr = java_trait_constr + "\t\t}"
 845         for var in field_vars:
 846             if isinstance(var, ConvInfo):
 847                 java_trait_constr = java_trait_constr + ", " + var.arg_name
 848             else:
 849                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
 850                 for suparg in var[2]:
 851                     if isinstance(suparg, ConvInfo):
 852                         java_trait_constr += ", " + suparg.arg_name
 853                     else:
 854                         java_trait_constr += ", " + suparg[1]
 855                 java_trait_constr += ").bindings_instance"
 856                 for suparg in var[2]:
 857                     if isinstance(suparg, ConvInfo):
 858                         java_trait_constr += ", " + suparg.arg_name
 859                     else:
 860                         java_trait_constr += ", " + suparg[1]
 861         out_java_trait = out_java_trait + "\t}\n"
 862         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
 863
 864         out_java = out_java + "\t}\n"
 865
 866         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
 867         for var in flattened_field_vars:
 868             if isinstance(var, ConvInfo):
 869                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
 870             else:
 871                 out_java = out_java + ", " + var[0] + " " + var[1]
 872         out_java = out_java + ");\n"
 873
 874         # Now that we've written out our java code (and created java_meths), generate C
 875         out_c = "typedef struct " + struct_name + "_JCalls {\n"
 876         out_c = out_c + "\tatomic_size_t refcnt;\n"
 877         out_c = out_c + "\tJavaVM *vm;\n"
 878         out_c = out_c + "\tjweak o;\n"
 879         for var in flattened_field_vars:
 880             if isinstance(var, ConvInfo):
 881                 # We're a regular ol' field
 882                 pass
 883             else:
 884                 # We're a supertrait
 885                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
 886         for fn in field_fns:
 887             if fn.fn_name != "free" and fn.fn_name != "cloned":
 888                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
 889         out_c = out_c + "} " + struct_name + "_JCalls;\n"
 890
 891         for fn_line in field_fns:
 892             if fn_line.fn_name == "free":
 893                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
 894                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 895                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
 896                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 897                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
 898                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
 899                 out_c = out_c + "\t\tFREE(j_calls);\n"
 900                 out_c = out_c + "\t}\n}\n"
 901
 902         for idx, fn_line in enumerate(field_fns):
 903             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
 904                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
 905                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
 906                 if fn_line.self_is_const:
 907                     out_c = out_c + "const void* this_arg"
 908                 else:
 909                     out_c = out_c + "void* this_arg"
 910
 911                 for idx, arg in enumerate(fn_line.args_ty):
 912                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
 913
 914                 out_c = out_c + ") {\n"
 915                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
 916                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
 917
 918                 for arg_info in fn_line.args_ty:
 919                     if arg_info.ret_conv is not None:
 920                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
 921                         out_c = out_c + arg_info.arg_name
 922                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
 923
 924                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
 925                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
 926                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 927                 elif fn_line.ret_ty_info.c_ty == "void":
 928                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 929                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
 930                     # Manually write out String methods as they're just an Object
 931                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 932                 elif not fn_line.ret_ty_info.passed_as_ptr:
 933                     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"
 934                 else:
 935                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
 936
 937                 for idx, arg_info in enumerate(fn_line.args_ty):
 938                     if arg_info.ret_conv is not None:
 939                         out_c = out_c + ", " + arg_info.ret_conv_name
 940                     else:
 941                         out_c = out_c + ", " + arg_info.arg_name
 942                 out_c = out_c + ");\n"
 943
 944                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
 945                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
 946                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
 947                 out_c += "\t}\n"
 948
 949                 if fn_line.ret_ty_info.arg_conv is not None:
 950                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
 951                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 952                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
 953                 else:
 954                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
 955                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
 956                         out_c += "\treturn ret;\n"
 957
 958                 out_c = out_c + "}\n"
 959
 960         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
 961         can_clone_with_ptr = True
 962         for var in field_vars:
 963             if isinstance(var, ConvInfo):
 964                 can_clone_with_ptr = False
 965         if can_clone_with_ptr:
 966             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
 967             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
 968             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
 969             for var in field_vars:
 970                 if not isinstance(var, ConvInfo):
 971                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
 972             out_c = out_c + "}\n"
 973
 974         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
 975         for var in flattened_field_vars:
 976             if isinstance(var, ConvInfo):
 977                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
 978             else:
 979                 out_c = out_c + ", jobject " + var[1]
 980         out_c = out_c + ") {\n"
 981
 982         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
 983         out_c = out_c + "\tCHECK(c != NULL);\n"
 984         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
 985         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
 986         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
 987         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
 988
 989         for (fn_name, java_meth_descr) in java_meths:
 990             if fn_name != "free" and fn_name != "cloned":
 991                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
 992                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
 993
 994         for var in flattened_field_vars:
 995             if isinstance(var, ConvInfo) and var.arg_conv is not None:
 996                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
 997         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
 998         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
 999         for fn_line in field_fns:
1000             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1001                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1002             elif fn_line.fn_name == "free":
1003                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1004             else:
1005                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1006         for var in field_vars:
1007             if isinstance(var, ConvInfo):
1008                 if var.arg_conv_name is not None:
1009                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1010                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1011                 else:
1012                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1013                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1014             else:
1015                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1016                 for suparg in var[2]:
1017                     if isinstance(suparg, ConvInfo):
1018                         out_c = out_c + ", " + suparg.arg_name
1019                     else:
1020                         out_c = out_c + ", " + suparg[1]
1021                 out_c += "),\n"
1022         out_c = out_c + "\t};\n"
1023         for var in flattened_field_vars:
1024             if not isinstance(var, ConvInfo):
1025                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
1026         out_c = out_c + "\treturn ret;\n"
1027         out_c = out_c + "}\n"
1028
1029         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1030         for var in flattened_field_vars:
1031             if isinstance(var, ConvInfo):
1032                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1033             else:
1034                 out_c = out_c + ", jobject " + var[1]
1035         out_c = out_c + ") {\n"
1036         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1037         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1038         for var in flattened_field_vars:
1039             if isinstance(var, ConvInfo):
1040                 out_c = out_c + ", " + var.arg_name
1041             else:
1042                 out_c = out_c + ", " + var[1]
1043         out_c = out_c + ");\n"
1044         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1045         out_c = out_c + "}\n"
1046
1047         for var in flattened_field_vars:
1048             if not isinstance(var, ConvInfo):
1049                 out_java_trait += "\n\t/**\n"
1050                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1051                 out_java_trait += "\t */\n"
1052                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1053                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1054                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1055                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
1056                 out_java_trait += "\t\treturn res;\n"
1057                 out_java_trait += "\t}\n"
1058                 out_java_trait += "\n"
1059
1060                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1061
1062                 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"
1063                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1064                 out_c += "\treturn tag_ptr(&inp->" + var[1] + ", false);\n"
1065                 out_c += "}\n"
1066
1067         return (out_java, out_java_trait, out_c)
1068
1069     def trait_struct_inc_refcnt(self, ty_info):
1070         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1071         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1072         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1073         return base_conv
1074
1075     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1076         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1077         out_java_enum = ""
1078         out_java = ""
1079         out_c = ""
1080
1081         out_java_enum += (self.hu_struct_file_prefix)
1082         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1083         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1084         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1085         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1086         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1087         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1088         out_java_enum += ("\t\tsuper.finalize();\n")
1089         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1090         out_java_enum += ("\t}\n")
1091         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1092         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1093         java_hu_subclasses = ""
1094
1095         init_meth_jty_strs = {}
1096
1097         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1098         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1099         for var in variant_list:
1100             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1101             if var.var_docs is not None:
1102                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1103             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1104             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1105             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1106             init_meth_jty_str = ""
1107             init_meth_params = ""
1108             init_meth_body = ""
1109             hu_conv_body = ""
1110             for idx, (field_ty, field_docs) in enumerate(var.fields):
1111                 if idx > 0:
1112                     init_meth_params = init_meth_params + ", "
1113
1114                 java_ty = field_ty.java_ty
1115                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1116                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1117                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1118                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1119                 if field_docs is not None:
1120                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1121                 java_hu_subclasses += "\t\t"
1122                 if field_ty.nullable:
1123                     java_hu_subclasses += "@Nullable "
1124                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1125                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1126
1127                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1128                 if field_ty.to_hu_conv is not None:
1129                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1130                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1131                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1132                 else:
1133                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1134                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1135             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1136             out_java +=  (init_meth_body)
1137             out_java +=  ("}\n")
1138             out_java += ("\t\t}\n")
1139             out_java_enum += ("\t\t}\n")
1140             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"
1141             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1142             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1143             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1144         out_java += ("\t\tstatic native void init();\n")
1145         out_java += ("\t}\n")
1146         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1147         out_java_enum += (java_hu_subclasses)
1148         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1149         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1150
1151         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1152
1153         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")
1154         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1155         out_c += ("\tswitch(obj->tag) {\n")
1156         for var in variant_list:
1157             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1158             c_params = []
1159             for idx, (field_map, field_docs) in enumerate(var.fields):
1160                 if field_map.ret_conv is not None:
1161                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1162                     if var.tuple_variant:
1163                         out_c += "obj->" + camel_to_snake(var.var_name)
1164                     else:
1165                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1166                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1167                     c_params.append(field_map.ret_conv_name)
1168                 else:
1169                     if var.tuple_variant:
1170                         c_params.append("obj->" + camel_to_snake(var.var_name))
1171                     else:
1172                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1173             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1174             out_c += ("\t\t}\n")
1175         out_c += ("\t\tdefault: abort();\n")
1176         out_c += ("\t}\n}\n")
1177         return (out_java, out_java_enum, out_c)
1178
1179     def map_opaque_struct(self, struct_name, struct_doc_comment):
1180         out_opaque_struct_human = ""
1181         out_opaque_struct_human += self.hu_struct_file_prefix
1182         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1183         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1184         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1185         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1186         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1187             out_opaque_struct_human += (" implements AutoCloseable")
1188         out_opaque_struct_human += (" {\n")
1189         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1190         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1191             out_opaque_struct_human += ("\t@Override public void close() {\n")
1192         else:
1193             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1194             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1195             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1196         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1197         out_opaque_struct_human += ("\t}\n\n")
1198         return out_opaque_struct_human
1199
1200     def map_tuple(self, struct_name):
1201         return self.map_opaque_struct(struct_name, "A Tuple")
1202
1203     def map_result(self, struct_name, res_map, err_map):
1204         human_ty = struct_name.replace("LDKCResult", "Result")
1205         java_hu_struct = ""
1206         java_hu_struct += self.hu_struct_file_prefix
1207         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1208         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1209         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1210         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1211         java_hu_struct += "\t}\n\n"
1212         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1213         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1214         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1215         java_hu_struct += "\t\t} else {\n"
1216         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1217         java_hu_struct += "\t\t}\n"
1218         java_hu_struct += "\t}\n"
1219
1220         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1221
1222         if res_map.java_hu_ty != "void":
1223             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1224         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1225         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1226         if res_map.java_hu_ty == "void":
1227             pass
1228         elif res_map.to_hu_conv is not None:
1229             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1230             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1231             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1232         else:
1233             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1234         java_hu_struct += "\t\t}\n"
1235         java_hu_struct += "\t}\n\n"
1236
1237         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1238         if err_map.java_hu_ty != "void":
1239             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1240         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1241         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1242         if err_map.java_hu_ty == "void":
1243             pass
1244         elif err_map.to_hu_conv is not None:
1245             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1246             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1247             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1248         else:
1249             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1250         java_hu_struct += "\t\t}\n"
1251
1252         java_hu_struct += "\t}\n\n"
1253         return java_hu_struct
1254
1255     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):
1256         out_java = ""
1257         out_c = ""
1258         out_java_struct = None
1259
1260         out_java += ("\tpublic static native ")
1261         out_c += (self.c_fn_ty_pfx)
1262         out_c += (return_type_info.c_ty)
1263         out_java += (return_type_info.java_ty)
1264         if return_type_info.ret_conv is not None:
1265             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1266         out_java += (" " + method_name + "(")
1267         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1268         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1269
1270         for idx, arg_conv_info in enumerate(argument_types):
1271             if idx != 0:
1272                 out_java += (", ")
1273                 out_c += (", ")
1274             if arg_conv_info.c_ty != "void":
1275                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1276                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1277
1278         out_java_struct = ""
1279         extra_java_struct_out = ""
1280         if not args_known:
1281             out_java_struct += ("\t// Skipped " + method_name + "\n")
1282         else:
1283             if doc_comment is not None:
1284                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1285             if return_type_info.nullable:
1286                 out_java_struct += "\t@Nullable\n"
1287             if not takes_self:
1288                 if meth_n == "new":
1289                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1290                 elif meth_n == "default":
1291                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1292                 else:
1293                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1294             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1295                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1296             else:
1297                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1298                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1299                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1300                     extra_java_struct_out += "\t}\n"
1301                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1302                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1303                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1304                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1305                     extra_java_struct_out += "\t}\n"
1306                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1307             for idx, arg in enumerate(argument_types):
1308                 if idx != 0:
1309                     if not takes_self or idx > 1:
1310                         out_java_struct += ", "
1311                 elif takes_self:
1312                     continue
1313                 if arg.java_ty != "void":
1314                     if arg.arg_name in default_constructor_args:
1315                         assert not arg.nullable
1316                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1317                             if explode_idx != 0:
1318                                 out_java_struct += (", ")
1319                             out_java_struct += (
1320                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1321                     else:
1322                         if arg.nullable:
1323                             out_java_struct += "@Nullable "
1324                         ty_string = self.fully_qualified_hu_ty_path(arg)
1325                         out_java_struct += ty_string + " " + arg.arg_name
1326         out_java += (");\n")
1327         out_c += (") {\n")
1328         if out_java_struct is not None:
1329             out_java_struct += (") {\n")
1330         for info in argument_types:
1331             if info.arg_conv is not None:
1332                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1333         if return_type_info.ret_conv is not None:
1334             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1335         elif return_type_info.c_ty != "void":
1336             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1337         else:
1338             out_c += ("\t")
1339         if c_call_string is None:
1340             out_c += (method_name + "(")
1341         else:
1342             out_c += (c_call_string)
1343         for idx, info in enumerate(argument_types):
1344             if info.arg_conv_name is not None:
1345                 if idx != 0:
1346                     out_c += (", ")
1347                 elif c_call_string is not None:
1348                     continue
1349                 out_c += (info.arg_conv_name)
1350         out_c += (")")
1351         if return_type_info.ret_conv is not None:
1352             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1353         else:
1354             out_c += (";")
1355         for info in argument_types:
1356             if info.arg_conv_cleanup is not None:
1357                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1358         if return_type_info.ret_conv is not None:
1359             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1360         elif return_type_info.c_ty != "void":
1361             out_c += ("\n\treturn ret_val;")
1362         out_c += ("\n}\n\n")
1363
1364         if args_known:
1365             out_java_struct += ("\t\t")
1366             if return_type_info.java_ty != "void":
1367                 out_java_struct += (return_type_info.java_ty + " ret = ")
1368             out_java_struct += ("bindings." + method_name + "(")
1369             for idx, info in enumerate(argument_types):
1370                 if idx != 0:
1371                     out_java_struct += (", ")
1372                 if idx == 0 and takes_self:
1373                     out_java_struct += ("this.ptr")
1374                 elif info.arg_name in default_constructor_args:
1375                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1376                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1377                         if explode_idx != 0:
1378                             out_java_struct += (", ")
1379                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1380                         if explode_arg.from_hu_conv is not None:
1381                             out_java_struct += (
1382                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1383                         else:
1384                             out_java_struct += (expl_arg_name)
1385                     out_java_struct += (")")
1386                 elif info.from_hu_conv is not None:
1387                     out_java_struct += (info.from_hu_conv[0])
1388                 else:
1389                     out_java_struct += (info.arg_name)
1390             out_java_struct += (");\n")
1391
1392             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1393             # the stack, calling its finalizer immediately even if member methods are *actively
1394             # executing* on the same object, as long as said object is on the stack. There is no
1395             # concrete specification for when the optimizer is allowed to do this, and when it is
1396             # not, so there is absolutely no way to be certain that this fix suffices.
1397             #
1398             # Instead, the "Java Language Specification" says only that an object is reachable
1399             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1400             # computation from any live thread". To any sensible reader this would mean actively
1401             # executing a member function on an object would make it not eligible for finalization.
1402             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1403             # very explicitly in fact, but those are just, like, words, man.
1404             #
1405             # In the seemingly non-normative text further down, a few examples of things the
1406             # optimizer can do are given, including "if the values in an object's fields are
1407             # stored in registers[, t]he may then access the registers instead of the object, and
1408             # never access the object again[, implying] that the object is garbage". This appears
1409             # to fully contradict both the above statement, the API documentation in java.lang.ref
1410             # regarding when a reference is "strongly reachable", and basic common sense. There is
1411             # no concrete set of limitations stated, however, seemingly implying the JIT could
1412             # decide your code would run faster by simply garbage collecting everything
1413             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1414             # entirely flying blind here. We add some fences and hope that its sufficient, but
1415             # with no specification to rely on, we cannot be certain of anything.
1416             #
1417             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1418             # object will be considered available for garbage collection once the JIT kicks in, so
1419             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1420             for idx, info in enumerate(argument_types):
1421                 if idx == 0 and takes_self:
1422                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1423                 elif info.arg_name in default_constructor_args:
1424                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1425                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1426                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1427                 elif info.c_ty != "void":
1428                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1429
1430             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1431                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1432
1433             if return_type_info.to_hu_conv is not None:
1434                 if not takes_self:
1435                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1436                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1437                 else:
1438                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1439
1440             for idx, info in enumerate(argument_types):
1441                 if idx == 0 and takes_self:
1442                     pass
1443                 elif info.arg_name in default_constructor_args:
1444                     for explode_arg in default_constructor_args[info.arg_name]:
1445                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1446                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1447                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1448                                                                                                expl_arg_name).replace(
1449                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1450                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1451                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1452                         out_java_struct += (
1453                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1454                     else:
1455                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1456
1457             if takes_self and not takes_self_as_ref:
1458                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1459             if return_type_info.to_hu_conv_name is not None:
1460                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1461             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1462                 out_java_struct += ("\t\treturn ret;\n")
1463             out_java_struct += ("\t}\n\n")
1464
1465         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1466
1467     def cleanup(self):
1468         pass