Add handling for signed int64 type
[ldk-java] / 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             int64_t = ['long'],
21         )
22         self.java_type_map = dict(
23             String = "String"
24         )
25         self.java_hu_type_map = dict(
26             String = "String"
27         )
28
29         self.to_hu_conv_templates = dict(
30             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}); }',
31             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}); }'
32         )
33
34         self.bindings_header = """package org.ldk.impl;
35 import org.ldk.enums.*;
36 import org.ldk.impl.version;
37 import java.io.File;
38 import java.io.InputStream;
39 import java.io.IOException;
40 import java.nio.file.Files;
41 import java.nio.file.Path;
42 import java.nio.file.StandardCopyOption;
43
44 public class bindings {
45         static {
46                 try {
47                         // Try to load natively first, this works on Android and in testing.
48                         System.loadLibrary(\"lightningjni\");
49                 } catch (UnsatisfiedLinkError system_load_err) {
50                         // Otherwise try to load from the library jar.
51                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
52                         tmpdir.mkdir(); // If it fails to create, assume it was there already
53                         tmpdir.deleteOnExit();
54                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
55                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
56                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
57                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
58                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
59                                 Runtime.getRuntime().load(libpath.toString());
60                         } catch (Exception e) {
61                                 System.err.println("Failed to load LDK native library.");
62                                 System.err.println("System LDK native library load failed with: " + system_load_err);
63                                 System.err.println("Resource-based LDK native library load failed with: " + e);
64                                 throw new IllegalArgumentException(e);
65                         }
66                 }
67                 init(java.lang.Enum.class);
68                 init_class_cache();
69                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
70                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
71                 // Fetching the LDK versions from C also checks that the header and binaries match
72                 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());
73         }
74         static native void init(java.lang.Class c);
75         static native void init_class_cache();
76         static native String get_lib_version_string();
77
78         public static native String get_ldk_c_bindings_version();
79         public static native String get_ldk_version();
80
81 """
82         self.bindings_version_file = """package org.ldk.impl;
83
84 public class version {
85         public static String get_ldk_java_bindings_version() {
86                 return "<git_version_ldk_garbagecollected>";
87         }
88 }"""
89
90         self.util_fn_pfx = """package org.ldk.structs;
91 import org.ldk.impl.bindings;
92 import org.ldk.enums.*;
93 import org.ldk.util.*;
94 import java.util.Arrays;
95 import java.lang.ref.Reference;
96 import javax.annotation.Nullable;
97
98 public class UtilMethods {
99 """
100         self.util_fn_sfx = "}"
101         self.common_base = """package org.ldk.structs;
102 import java.util.LinkedList;
103 class CommonBase {
104         long ptr;
105         LinkedList<Object> ptrs_to = new LinkedList();
106         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
107 }
108 """
109
110         self.txout_defn = """public class TxOut extends CommonBase {
111         /** The script_pubkey in this output */
112         public final byte[] script_pubkey;
113         /** The value, in satoshis, of this output */
114         public final long value;
115
116         TxOut(java.lang.Object _dummy, long ptr) {
117                 super(ptr);
118                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
119                 this.value = bindings.TxOut_get_value(ptr);
120         }
121         public TxOut(long value, byte[] script_pubkey) {
122                 super(bindings.TxOut_new(script_pubkey, value));
123                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
124                 this.value = bindings.TxOut_get_value(ptr);
125         }
126
127         @Override @SuppressWarnings(\"deprecation\")
128         protected void finalize() throws Throwable {
129                 super.finalize();
130                 if (ptr != 0) { bindings.TxOut_free(ptr); }
131         }
132 }"""
133
134         self.txin_defn = """public class TxIn extends CommonBase {
135         /** The witness in this input, in serialized form */
136         public final byte[] witness;
137         /** The script_sig in this input */
138         public final byte[] script_sig;
139         /** The transaction output's sequence number */
140         public final int sequence;
141         /** The txid this input is spending */
142         public final byte[] previous_txid;
143         /** The output index within the spent transaction of the output this input is spending */
144         public final int previous_vout;
145
146         TxIn(java.lang.Object _dummy, long ptr) {
147                 super(ptr);
148                 this.witness = bindings.TxIn_get_witness(ptr);
149                 this.script_sig = bindings.TxIn_get_script_sig(ptr);
150                 this.sequence = bindings.TxIn_get_sequence(ptr);
151                 this.previous_txid = bindings.TxIn_get_previous_txid(ptr);
152                 this.previous_vout = bindings.TxIn_get_previous_vout(ptr);
153         }
154         /** Constructs a new TxIn, note that previous_txid must be exactly 32 bytes */
155         public TxIn(byte[] witness, byte[] script_sig, int sequence, byte[] previous_txid, int previous_vout) {
156                 this(null, bindings.TxIn_new(witness, script_sig, sequence, previous_txid, previous_vout));
157         }
158
159         @Override @SuppressWarnings(\"deprecation\")
160         protected void finalize() throws Throwable {
161                 super.finalize();
162                 if (ptr != 0) { bindings.TxIn_free(ptr); }
163         }
164 }"""
165
166         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
167         /** The bytes of the scalar value, in big endian */
168         public final byte[] scalar_bytes;
169
170         BigEndianScalar(java.lang.Object _dummy, long ptr) {
171                 super(ptr);
172                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
173         }
174         public BigEndianScalar(byte[] scalar_bytes) {
175                 super(bindings.BigEndianScalar_new(scalar_bytes));
176                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
177         }
178
179         @Override @SuppressWarnings(\"deprecation\")
180         protected void finalize() throws Throwable {
181                 super.finalize();
182                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
183         }
184 }"""
185
186
187         self.c_file_pfx = """#include <jni.h>
188 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
189 #define int64_t jlong
190 #include \"org_ldk_impl_bindings.h\"
191 #include <lightning.h>
192 #include <string.h>
193 #include <stdatomic.h>
194 #include <stdlib.h>
195
196 #define LIKELY(v) __builtin_expect(!!(v), 1)
197 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
198
199 """
200
201         if self.target == Target.ANDROID:
202             self.c_file_pfx = self.c_file_pfx + """
203 #include <android/log.h>
204 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
205
206 #include <unistd.h>
207 #include <pthread.h>
208 static void* redirect_stderr(void* ignored) {
209         int pipes[2];
210         pipe(pipes);
211         dup2(pipes[1], STDERR_FILENO);
212         char buf[8192];
213         memset(buf, 0, 8192);
214         ssize_t len;
215         while ((len = read(pipes[0], buf, 8191)) > 0) {
216                 DEBUG_PRINT("%s\\n", buf);
217                 memset(buf, 0, 8192);
218         }
219         DEBUG_PRINT("End of stderr???\\n");
220         return 0;
221 }
222 void __attribute__((constructor)) spawn_stderr_redirection() {
223         pthread_t thread;
224         pthread_create(&thread, NULL, &redirect_stderr, NULL);
225 }
226 """
227         else:
228             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
229
230         if not DEBUG or self.target == Target.MACOS:
231             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
232 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
233 #define CHECK_ACCESS(p)
234 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
235 """
236         if not DEBUG:
237             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
238 #define CHECK(a)
239 """
240         if DEBUG:
241             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
242 // Always run a, then assert it is true:
243 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
244 // Assert a is true or do nothing
245 #define CHECK(a) DO_ASSERT(a)
246
247 void __attribute__((constructor)) debug_log_version() {
248         if (check_get_ldk_version() == NULL)
249                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
250         if (check_get_ldk_bindings_version() == NULL)
251                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
252 }
253 """
254
255             if self.target != Target.MACOS:
256                 self.c_file_pfx += """
257 // Running a leak check across all the allocations and frees of the JDK is a mess,
258 // so instead we implement our own naive leak checker here, relying on the -wrap
259 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
260 // and free'd in Rust or C across the generated bindings shared library.
261 #include <threads.h>
262 """
263
264                 if self.target == Target.ANDROID:
265                     self.c_file_pfx = self.c_file_pfx + """
266 #include <unwind.h>
267 #include <dlfcn.h>
268
269 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
270 // symbols, so we only use it on Android, where execinfo.h is unavailable.
271
272 struct BacktraceState {
273         void** current;
274         void** end;
275 };
276 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
277         struct BacktraceState* state = (struct BacktraceState*)arg;
278         uintptr_t pc = _Unwind_GetIP(context);
279         if (pc) {
280                 if (state->current == state->end) {
281                         return _URC_END_OF_STACK;
282                 } else {
283                         *state->current++ = (void*)(pc);
284                 }
285         }
286         return _URC_NO_REASON;
287 }
288
289 int backtrace(void** buffer, int max) {
290         struct BacktraceState state = { buffer, buffer + max };
291         _Unwind_Backtrace(unwind_callback, &state);
292         return state.current - buffer;
293 }
294
295 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
296         for (int idx = 0; idx < count; ++idx) {
297                 Dl_info info;
298                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
299                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
300                 } else {
301                         DEBUG_PRINT("%p: ???", buffer[idx]);
302                 }
303         }
304 }
305 """
306                 else:
307                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
308                 self.c_file_pfx = self.c_file_pfx + """
309 #include <unistd.h>
310 #include <pthread.h>
311 static pthread_mutex_t allocation_mtx;
312
313 void __attribute__((constructor)) init_mtx() {
314         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
315 }
316
317 #define BT_MAX 128
318 typedef struct allocation {
319         struct allocation* next;
320         void* ptr;
321         const char* struct_name;
322         void* bt[BT_MAX];
323         int bt_len;
324         unsigned long alloc_len;
325 } allocation;
326 static allocation* allocation_ll = NULL;
327
328 void* __real_malloc(size_t len);
329 void* __real_calloc(size_t nmemb, size_t len);
330 static void new_allocation(void* res, const char* struct_name, size_t len) {
331         allocation* new_alloc = __real_malloc(sizeof(allocation));
332         new_alloc->ptr = res;
333         new_alloc->struct_name = struct_name;
334         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
335         new_alloc->alloc_len = len;
336         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
337         new_alloc->next = allocation_ll;
338         allocation_ll = new_alloc;
339         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
340 }
341 static void* MALLOC(size_t len, const char* struct_name) {
342         void* res = __real_malloc(len);
343         new_allocation(res, struct_name, len);
344         return res;
345 }
346 void __real_free(void* ptr);
347 static void alloc_freed(void* ptr) {
348         allocation* p = NULL;
349         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
350         allocation* it = allocation_ll;
351         while (it->ptr != ptr) {
352                 p = it; it = it->next;
353                 if (it == NULL) {
354                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
355                         void* bt[BT_MAX];
356                         int bt_len = backtrace(bt, BT_MAX);
357                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
358                         DEBUG_PRINT("\\n\\n");
359                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
360                         return; // addrsan should catch malloc-unknown and print more info than we have
361                 }
362         }
363         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
364         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
365         DO_ASSERT(it->ptr == ptr);
366         __real_free(it);
367 }
368 static void FREE(void* ptr) {
369         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
370         alloc_freed(ptr);
371         __real_free(ptr);
372 }
373
374 void* __wrap_malloc(size_t len) {
375         void* res = __real_malloc(len);
376         new_allocation(res, "malloc call", len);
377         return res;
378 }
379 void* __wrap_calloc(size_t nmemb, size_t len) {
380         void* res = __real_calloc(nmemb, len);
381         new_allocation(res, "calloc call", len);
382         return res;
383 }
384 void __wrap_free(void* ptr) {
385         if (ptr == NULL) return;
386         alloc_freed(ptr);
387         __real_free(ptr);
388 }
389
390 static void CHECK_ACCESS(const void* ptr) {
391         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
392         allocation* it = allocation_ll;
393         while (it->ptr != ptr) {
394                 it = it->next;
395                 if (it == NULL) {
396                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
397                         void* bt[BT_MAX];
398                         int bt_len = backtrace(bt, BT_MAX);
399                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
400                         DEBUG_PRINT("\\n\\n");
401                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
402                         return; // addrsan should catch and print more info than we have
403                 }
404         }
405         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
406 }
407 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
408         if (v.is_owned && v.inner != NULL) { \\
409                 const void *p = __unmangle_inner_ptr(v.inner); \\
410                 if (p != NULL) { \\
411                         CHECK_ACCESS(p); \\
412                 } \\
413         }
414
415 void* __real_realloc(void* ptr, size_t newlen);
416 void* __wrap_realloc(void* ptr, size_t len) {
417         if (ptr != NULL) alloc_freed(ptr);
418         void* res = __real_realloc(ptr, len);
419         new_allocation(res, "realloc call", len);
420         return res;
421 }
422 void __wrap_reallocarray(void* ptr, size_t new_sz) {
423         // Rust doesn't seem to use reallocarray currently
424         DO_ASSERT(false);
425 }
426
427 void __attribute__((destructor)) check_leaks() {
428         unsigned long alloc_count = 0;
429         unsigned long alloc_size = 0;
430         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
431         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
432         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
433         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
434                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
435                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
436                 DEBUG_PRINT("\\n\\n");
437                 alloc_count++;
438                 alloc_size += a->alloc_len;
439         }
440         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
441         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
442         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
443 }
444 """
445         self.c_file_pfx = self.c_file_pfx + """
446 static jmethodID ordinal_meth = NULL;
447 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
448         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
449         CHECK(ordinal_meth != NULL);
450 }
451
452 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
453 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
454 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
455 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
456
457 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
458 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
459 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
460
461 typedef jlongArray int64_tArray;
462 typedef jbyteArray int8_tArray;
463 typedef jshortArray int16_tArray;
464
465 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
466         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
467         char* conv_buf = MALLOC(len + 1, "str conv buf");
468         memcpy(conv_buf, chars, len);
469         conv_buf[len] = 0;
470         jstring ret = (*env)->NewStringUTF(env, conv_buf);
471         FREE(conv_buf);
472         return ret;
473 }
474 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
475         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
476         char* newchars = MALLOC(str_len + 1, "String chars");
477         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
478         memcpy(newchars, jchars, str_len);
479         newchars[str_len] = 0;
480         (*env)->ReleaseStringUTFChars(env, str, jchars);
481         LDKStr res = {
482                 .chars = newchars,
483                 .len = str_len,
484                 .chars_is_owned = true
485         };
486         return res;
487 }
488
489 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
490         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
491 }
492 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
493         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
494 }
495 #include "version.c"
496 """
497         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
498         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
499 }"""
500
501         self.hu_struct_file_prefix = """package org.ldk.structs;
502
503 import org.ldk.impl.bindings;
504 import org.ldk.enums.*;
505 import org.ldk.util.*;
506 import java.util.Arrays;
507 import java.lang.ref.Reference;
508 import javax.annotation.Nullable;
509
510 """
511         self.hu_struct_file_suffix = ""
512         self.c_fn_ty_pfx = "JNIEXPORT "
513         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
514         self.file_ext = ".java"
515         self.ptr_c_ty = "int64_t"
516         self.ptr_native_ty = "long"
517         self.u128_native_ty = "UInt128"
518         self.usize_c_ty = "int64_t"
519         self.usize_native_ty = "long"
520         self.native_zero_ptr = "0"
521         self.result_c_ty = "jclass"
522         self.ptr_arr = "jobjectArray"
523         self.is_arr_some_check = ("", " != NULL")
524         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
525
526     def bindings_footer(self):
527         return "}\n"
528
529     def construct_jenv(self):
530         res =  "JNIEnv *env;\n"
531         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
532         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
533         if self.target == Target.ANDROID:
534             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
535         else:
536             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
537         res += "} else {\n"
538         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
539         res += "}\n"
540         return res
541     def deconstruct_jenv(self):
542         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
543         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
544         res += "}\n"
545         return res
546
547     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
548         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
549             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
550         return None
551     def create_native_arr_call(self, arr_len, ty_info):
552         if ty_info.c_ty == "int8_tArray":
553             return "(*env)->NewByteArray(env, " + arr_len + ")"
554         elif ty_info.subty.c_ty.endswith("Array"):
555             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
556             self.c_array_class_caches.add(clz_var)
557             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
558         elif ty_info.subty.c_ty == "jstring":
559             return "(*env)->NewObjectArray(env, " + arr_len + ", String_clz, NULL);\n"
560         else:
561             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
562     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
563         if ty_info.c_ty == "int8_tArray":
564             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
565         elif ty_info.c_ty == "int16_tArray":
566             return ("(*env)->SetShortArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
567         else:
568             assert False
569     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
570         if "String" in ty_info.java_ty:
571             return None
572         if ty_info.c_ty == "int8_tArray" or ty_info.c_ty == "int16_tArray":
573             fn_ty = "Byte" if ty_info.c_ty == "int8_tArray" else "Short"
574             if copy:
575                 return "(*env)->Get" + fn_ty + "ArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
576             else:
577                 return "(*env)->Get" + fn_ty + "ArrayElements (env, " + arr_name + ", NULL)"
578         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
579             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
580         else:
581             return None
582     def get_native_arr_elem(self, arr_name, idxc, ty_info):
583         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
584             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
585         else:
586             assert False # Only called if above is None
587     def get_native_arr_ptr_call(self, ty_info):
588         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
589             return None
590         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
591     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
592         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
593             return None
594         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
595     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
596         if ty_info.c_ty == "int8_tArray":
597             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
598         else:
599             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
600
601     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
602         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
603             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
604         elif elem_ty.java_ty == "long":
605             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
606         elif elem_ty.java_hu_ty == "UInt5":
607             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
608         elif elem_ty.java_hu_ty == "WitnessVersion":
609             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
610         else:
611             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
612
613     def str_ref_to_native_call(self, var_name, str_len):
614         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
615     def str_ref_to_c_call(self, var_name):
616         return "java_to_owned_str(env, " + var_name + ")"
617     def str_to_hu_conv(self, var_name):
618         return None
619     def str_from_hu_conv(self, var_name):
620         return None
621
622     def c_fn_name_define_pfx(self, fn_name, has_args):
623         if has_args:
624             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
625         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
626
627     def init_str(self):
628         res = ""
629         for ty in sorted(self.c_array_class_caches):
630             res = res + "static jclass " + ty + "_clz = NULL;\n"
631         res = res + "static jclass String_clz = NULL;\n"
632         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
633         for ty in sorted(self.c_array_class_caches):
634             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
635             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
636             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
637         res = res + "\tString_clz = (*env)->FindClass(env, \"java/lang/String\");\n"
638         res = res + "\tCHECK(String_clz != NULL);\n"
639         res = res + "\tString_clz = (*env)->NewGlobalRef(env, String_clz);\n"
640
641         res = res + "}\n"
642         return res
643
644     def var_decl_statement(self, ty_string, var_name, statement):
645         return ty_string + " " + var_name + " = " + statement
646
647     def get_java_arr_len(self, arr_name):
648         return arr_name + ".length"
649     def get_java_arr_elem(self, elem_ty, arr_name, idx):
650         return arr_name + "[" + idx + "]"
651     def constr_hu_array(self, ty_info, arr_len):
652         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
653         conv = "new " + base_ty + "[" + arr_len + "]"
654         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
655             # Do a bit of a dance to move any excess [] to the end
656             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
657         return conv
658     def cleanup_converted_native_array(self, ty_info, arr_name):
659         return None
660
661     def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
662         mapped_ty = arr_ty.subty
663         if arr_ty.rust_obj == "LDKU128":
664             return ("" + arr_name + ".getLEBytes()", "")
665         if fixed_len is not None:
666             if mapped_ty.c_ty == "int8_t" or mapped_ty.c_ty == "uint8_t":
667                 return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
668             elif mapped_ty.c_ty == "int16_t" or mapped_ty.c_ty == "uint16_t":
669                 return ("InternalUtils.check_arr_16_len(" + arr_name + ", " + fixed_len + ")", "")
670             else:
671                 print(arr_ty.c_ty)
672                 assert False
673         return None
674     def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
675         if arr_ty.rust_obj == "LDKU128":
676             return "org.ldk.util.UInt128 " + conv_name + " = new org.ldk.util.UInt128(" + arr_name + ");"
677         return None
678
679     def java_arr_ty_str(self, elem_ty_str):
680         return elem_ty_str + "[]"
681
682     def for_n_in_range(self, n, minimum, maximum):
683         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
684     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
685         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
686
687     def get_ptr(self, var):
688         return var + ".ptr"
689     def set_null_skip_free(self, var):
690         return var + ".ptr" + " = 0;"
691
692     def add_ref(self, holder, referent):
693         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
694
695     def fully_qualified_hu_ty_path(self, ty):
696         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
697             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
698         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt128" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
699             return "org.ldk.util." + ty.java_hu_ty
700         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
701             return "org.ldk.structs." + ty.java_hu_ty
702         return ty.java_hu_ty
703
704     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
705         out_java_enum = "package org.ldk.enums;\n\n"
706         out_java = ""
707         out_c = ""
708         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
709         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
710         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
711         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
712         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
713         out_c += "\t}\n"
714         out_c += "\tswitch (ord) {\n"
715
716         if enum_doc_comment is not None:
717             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
718         out_java_enum += "public enum " + struct_name + " {\n"
719         ord_v = 0
720         for var, var_docs in variants:
721             if var_docs is not None:
722                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
723             out_java_enum += "\t" + var + ",\n"
724             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
725             ord_v = ord_v + 1
726         out_java_enum = out_java_enum + "\t; static native void init();\n"
727         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
728         out_java_enum = out_java_enum + "}"
729         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
730         out_c += "\t}\n"
731         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
732         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
733         out_c += "}\n"
734
735         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
736         for var, _ in variants:
737             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
738         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"
739         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
740         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
741         for var, _ in variants:
742             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
743             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
744         out_c = out_c + "}\n"
745         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
746         out_c = out_c + "\tswitch (val) {\n"
747         ord_v = 0
748         for var, _ in variants:
749             out_c = out_c + "\t\tcase " + var + ":\n"
750             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
751             ord_v = ord_v + 1
752         out_c = out_c + "\t\tdefault: abort();\n"
753         out_c = out_c + "\t}\n"
754         out_c = out_c + "}\n\n"
755
756         return (out_c, out_java_enum, out_java)
757
758     def c_unitary_enum_to_native_call(self, ty_info):
759         return (ty_info.rust_obj + "_to_java(env, ", ")")
760     def native_unitary_enum_to_c_call(self, ty_info):
761         return (ty_info.rust_obj + "_from_java(env, ", ")")
762
763     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
764         out_c = ""
765         for var in variants:
766             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
767             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
768         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"
769         for var_name in variants:
770             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
771             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
772             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
773             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"
774             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
775         out_c = out_c + "}\n"
776         return out_c
777
778     def c_complex_enum_pass_ty(self, struct_name):
779         return "jobject"
780
781     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
782         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
783         for param in c_params:
784             ret = ret + ", " + param
785         return ret + ")"
786
787     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
788         out_java_trait = ""
789         out_java = ""
790
791         # First generate most of the Java code, note that we need information about java method argument strings for C
792         out_java_trait = out_java_trait + self.hu_struct_file_prefix
793         if trait_doc_comment is not None:
794             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
795         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
796         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
797         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
798         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
799         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
800         for var in flattened_field_vars:
801             if isinstance(var, ConvInfo):
802                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
803             else:
804                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
805         out_java_trait = out_java_trait + ") {\n"
806         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
807         for var in flattened_field_vars:
808             if isinstance(var, ConvInfo):
809                 if var.from_hu_conv is not None:
810                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
811                 else:
812                     out_java_trait = out_java_trait + ", " + var.arg_name
813             else:
814                 out_java_trait = out_java_trait + ", " + var[1]
815         out_java_trait = out_java_trait + "));\n"
816         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
817         for var in flattened_field_vars:
818             if isinstance(var, ConvInfo):
819                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
820                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
821             else:
822                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
823         out_java_trait += f"""          this.bindings_instance = arg;
824         }}
825         @Override @SuppressWarnings("deprecation")
826         protected void finalize() throws Throwable {{
827                 if (ptr != 0) {{ bindings.{struct_name.replace("LDK","")}_free(ptr); }} super.finalize();
828         }}
829         /**
830          * Destroys the object, freeing associated resources. After this call, any access
831          * to this object may result in a SEGFAULT or worse.
832          *
833          * You should generally NEVER call this method. You should let the garbage collector
834          * do this for you when it finalizes objects. However, it may be useful for types
835          * which represent locks and should be closed immediately to avoid holding locks
836          * until the GC runs.
837          */
838         public void destroy() {{
839                 if (ptr != 0) {{ bindings.{struct_name.replace("LDK","")}_free(ptr); }}
840                 ptr = 0;
841         }}
842 """
843
844         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
845         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
846         for var in flattened_field_vars:
847             if isinstance(var, ConvInfo):
848                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
849             else:
850                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
851                 # Java-implemented version, so we require users pass a Java implementation here :/
852                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
853         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
854         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
855         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
856         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
857         java_meths = []
858         for fn_line in field_fns:
859             java_meth_descr = "("
860             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
861                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
862                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
863                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
864                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
865
866                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
867                     if idx >= 1:
868                         out_java = out_java + ", "
869                         java_trait_constr = java_trait_constr + ", "
870                         out_java_trait = out_java_trait + ", "
871                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
872                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
873                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
874                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
875                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
876                 java_meths.append((fn_line.fn_name, java_meth_descr))
877
878                 out_java = out_java + ");\n"
879                 out_java_trait = out_java_trait + ");\n"
880                 java_trait_constr = java_trait_constr + ") {\n"
881
882                 for arg_info in fn_line.args_ty:
883                     if arg_info.to_hu_conv is not None:
884                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
885
886                 if fn_line.ret_ty_info.java_ty != "void":
887                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
888                 else:
889                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
890
891                 for idx, arg_info in enumerate(fn_line.args_ty):
892                     if idx != 0:
893                         java_trait_constr = java_trait_constr + ", "
894                     if arg_info.to_hu_conv_name is not None:
895                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
896                     else:
897                         java_trait_constr = java_trait_constr + arg_info.arg_name
898
899                 java_trait_constr += ");\n"
900                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
901                 if fn_line.ret_ty_info.java_ty != "void":
902                     if fn_line.ret_ty_info.from_hu_conv is not None:
903                         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"
904                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
905                             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"
906                         #if fn_line.ret_ty_info.rust_obj in result_types:
907                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
908                     else:
909                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
910                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
911         java_trait_constr = java_trait_constr + "\t\t}"
912         for var in field_vars:
913             if isinstance(var, ConvInfo):
914                 java_trait_constr = java_trait_constr + ", " + var.arg_name
915             else:
916                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
917                 suptrait_constr = ""
918                 for suparg in var[2]:
919                     if isinstance(suparg, ConvInfo):
920                         suptrait_constr += ", " + suparg.arg_name
921                     else:
922                         suptrait_constr += ", " + suparg[1] + "_impl"
923                 java_trait_constr += suptrait_constr + ").bindings_instance"
924                 for suparg in var[2]:
925                     if isinstance(suparg, ConvInfo):
926                         java_trait_constr += ", " + suparg.arg_name
927                     else:
928                         java_trait_constr += ", " + suparg[1] + ".new_impl("
929                         # Blindly assume that we can just strip the first arg to build the args for the supertrait
930                         java_trait_constr += suptrait_constr.split(", ", 1)[1]
931                         java_trait_constr += ").bindings_instance"
932         out_java_trait = out_java_trait + "\t}\n"
933         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
934
935         out_java = out_java + "\t}\n"
936
937         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
938         for var in flattened_field_vars:
939             if isinstance(var, ConvInfo):
940                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
941             else:
942                 out_java = out_java + ", " + var[0] + " " + var[1]
943         out_java = out_java + ");\n"
944
945         # Now that we've written out our java code (and created java_meths), generate C
946         out_c = "typedef struct " + struct_name + "_JCalls {\n"
947         out_c = out_c + "\tatomic_size_t refcnt;\n"
948         out_c = out_c + "\tJavaVM *vm;\n"
949         out_c = out_c + "\tjweak o;\n"
950         for var in flattened_field_vars:
951             if isinstance(var, ConvInfo):
952                 # We're a regular ol' field
953                 pass
954             else:
955                 # We're a supertrait
956                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
957         for fn in field_fns:
958             if fn.fn_name != "free" and fn.fn_name != "cloned":
959                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
960         out_c = out_c + "} " + struct_name + "_JCalls;\n"
961
962         for fn_line in field_fns:
963             if fn_line.fn_name == "free":
964                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
965                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
966                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
967                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
968                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
969                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
970                 out_c = out_c + "\t\tFREE(j_calls);\n"
971                 out_c = out_c + "\t}\n}\n"
972
973         for idx, fn_line in enumerate(field_fns):
974             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
975                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
976                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
977                 if fn_line.self_is_const:
978                     out_c = out_c + "const void* this_arg"
979                 else:
980                     out_c = out_c + "void* this_arg"
981
982                 for idx, arg in enumerate(fn_line.args_ty):
983                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
984
985                 out_c = out_c + ") {\n"
986                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
987                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
988
989                 for arg_info in fn_line.args_ty:
990                     if arg_info.ret_conv is not None:
991                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
992                         out_c = out_c + arg_info.arg_name
993                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
994
995                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
996                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
997                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
998                 elif fn_line.ret_ty_info.c_ty == "void":
999                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1000                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
1001                     # Manually write out String methods as they're just an Object
1002                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1003                 elif not fn_line.ret_ty_info.passed_as_ptr:
1004                     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"
1005                 else:
1006                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1007
1008                 for idx, arg_info in enumerate(fn_line.args_ty):
1009                     if arg_info.ret_conv is not None:
1010                         out_c = out_c + ", " + arg_info.ret_conv_name
1011                     else:
1012                         out_c = out_c + ", " + arg_info.arg_name
1013                 out_c = out_c + ");\n"
1014
1015                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
1016                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
1017                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
1018                 out_c += "\t}\n"
1019
1020                 if fn_line.ret_ty_info.arg_conv is not None:
1021                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
1022                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1023                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
1024                 else:
1025                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1026                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
1027                         out_c += "\treturn ret;\n"
1028
1029                 out_c = out_c + "}\n"
1030
1031         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
1032         can_clone_with_ptr = True
1033         for var in field_vars:
1034             if isinstance(var, ConvInfo):
1035                 can_clone_with_ptr = False
1036         if can_clone_with_ptr:
1037             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
1038             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
1039             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
1040             for var in flattened_field_vars:
1041                 if not isinstance(var, ConvInfo):
1042                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[2].replace(".", "->") + "->refcnt, 1, memory_order_release);\n"
1043             out_c = out_c + "}\n"
1044
1045         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
1046         for var in flattened_field_vars:
1047             if isinstance(var, ConvInfo):
1048                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1049             else:
1050                 out_c = out_c + ", jobject " + var[1]
1051         out_c = out_c + ") {\n"
1052
1053         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
1054         out_c = out_c + "\tCHECK(c != NULL);\n"
1055         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
1056         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
1057         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
1058         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
1059
1060         for (fn_name, java_meth_descr) in java_meths:
1061             if fn_name != "free" and fn_name != "cloned":
1062                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
1063                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
1064
1065         for var in flattened_field_vars:
1066             if isinstance(var, ConvInfo) and var.arg_conv is not None:
1067                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
1068         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
1069         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
1070         for fn_line in field_fns:
1071             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1072                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1073             elif fn_line.fn_name == "free":
1074                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1075             else:
1076                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1077         for var in field_vars:
1078             if isinstance(var, ConvInfo):
1079                 if var.arg_conv_name is not None:
1080                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1081                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1082                 else:
1083                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1084                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1085             else:
1086                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1087                 for suparg in var[2]:
1088                     if isinstance(suparg, ConvInfo):
1089                         out_c = out_c + ", " + suparg.arg_name
1090                     else:
1091                         out_c = out_c + ", " + suparg[1]
1092                 out_c += "),\n"
1093         out_c = out_c + "\t};\n"
1094         for var in flattened_field_vars:
1095             if not isinstance(var, ConvInfo):
1096                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[2] + ".this_arg;\n"
1097         out_c = out_c + "\treturn ret;\n"
1098         out_c = out_c + "}\n"
1099
1100         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1101         for var in flattened_field_vars:
1102             if isinstance(var, ConvInfo):
1103                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1104             else:
1105                 out_c = out_c + ", jobject " + var[1]
1106         out_c = out_c + ") {\n"
1107         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1108         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1109         for var in flattened_field_vars:
1110             if isinstance(var, ConvInfo):
1111                 out_c = out_c + ", " + var.arg_name
1112             else:
1113                 out_c = out_c + ", " + var[1]
1114         out_c = out_c + ");\n"
1115         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1116         out_c = out_c + "}\n"
1117
1118         for var in flattened_field_vars:
1119             if not isinstance(var, ConvInfo):
1120                 out_java_trait += "\n\t/**\n"
1121                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1122                 out_java_trait += "\t */\n"
1123                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1124                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1125                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1126                 out_java_trait += "\t\tres.ptrs_to.add(this);\n"
1127                 out_java_trait += "\t\treturn res;\n"
1128                 out_java_trait += "\t}\n"
1129                 out_java_trait += "\n"
1130
1131                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1132
1133                 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"
1134                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1135                 out_c += "\treturn tag_ptr(&inp->" + var[2] + ", false);\n"
1136                 out_c += "}\n"
1137
1138         return (out_java, out_java_trait, out_c)
1139
1140     def trait_struct_inc_refcnt(self, ty_info):
1141         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1142         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1143         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1144         return base_conv
1145
1146     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1147         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1148         out_java_enum = ""
1149         out_java = ""
1150         out_c = ""
1151
1152         out_java_enum += (self.hu_struct_file_prefix)
1153         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1154         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1155         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1156         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1157         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1158         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1159         out_java_enum += ("\t\tsuper.finalize();\n")
1160         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1161         out_java_enum += ("\t}\n")
1162         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1163         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1164         java_hu_subclasses = ""
1165
1166         init_meth_jty_strs = {}
1167
1168         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1169         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1170         for var in variant_list:
1171             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1172             if var.var_docs is not None:
1173                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1174             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1175             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1176             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1177             init_meth_jty_str = ""
1178             init_meth_params = ""
1179             init_meth_body = ""
1180             hu_conv_body = ""
1181             for idx, (field_ty, field_docs) in enumerate(var.fields):
1182                 if idx > 0:
1183                     init_meth_params = init_meth_params + ", "
1184
1185                 java_ty = field_ty.java_ty
1186                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1187                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1188                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1189                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1190                 if field_docs is not None:
1191                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1192                 java_hu_subclasses += "\t\t"
1193                 if field_ty.nullable:
1194                     java_hu_subclasses += "@Nullable "
1195                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1196                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1197
1198                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1199                 if field_ty.to_hu_conv is not None:
1200                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1201                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1202                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1203                 else:
1204                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1205                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1206             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1207             out_java +=  (init_meth_body)
1208             out_java +=  ("}\n")
1209             out_java += ("\t\t}\n")
1210             out_java_enum += ("\t\t}\n")
1211             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"
1212             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1213             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1214             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1215         out_java += ("\t\tstatic native void init();\n")
1216         out_java += ("\t}\n")
1217         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1218         out_java_enum += (java_hu_subclasses)
1219         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1220         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1221
1222         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1223
1224         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")
1225         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1226         out_c += ("\tswitch(obj->tag) {\n")
1227         for var in variant_list:
1228             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1229             c_params = []
1230             for idx, (field_map, field_docs) in enumerate(var.fields):
1231                 if field_map.ret_conv is not None:
1232                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1233                     if var.tuple_variant:
1234                         out_c += "obj->" + camel_to_snake(var.var_name)
1235                     else:
1236                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1237                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1238                     c_params.append(field_map.ret_conv_name)
1239                 else:
1240                     if var.tuple_variant:
1241                         c_params.append("obj->" + camel_to_snake(var.var_name))
1242                     else:
1243                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1244             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1245             out_c += ("\t\t}\n")
1246         out_c += ("\t\tdefault: abort();\n")
1247         out_c += ("\t}\n}\n")
1248         return (out_java, out_java_enum, out_c)
1249
1250     def map_opaque_struct(self, struct_name, struct_doc_comment):
1251         out_opaque_struct_human = ""
1252         out_opaque_struct_human += self.hu_struct_file_prefix
1253         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1254         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1255         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1256         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1257         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1258             out_opaque_struct_human += (" implements AutoCloseable")
1259         out_opaque_struct_human += (" {\n")
1260         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1261         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1262             out_opaque_struct_human += ("\t@Override public void close() {\n")
1263         else:
1264             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1265             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1266             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1267         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1268         out_opaque_struct_human += ("\t}\n\n")
1269         return out_opaque_struct_human
1270
1271     def map_tuple(self, struct_name):
1272         return self.map_opaque_struct(struct_name, "A Tuple")
1273
1274     def map_result(self, struct_name, res_map, err_map):
1275         human_ty = struct_name.replace("LDKCResult", "Result")
1276         java_hu_struct = ""
1277         java_hu_struct += self.hu_struct_file_prefix
1278         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1279         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1280         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1281         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1282         java_hu_struct += "\t}\n\n"
1283         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1284         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1285         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1286         java_hu_struct += "\t\t} else {\n"
1287         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1288         java_hu_struct += "\t\t}\n"
1289         java_hu_struct += "\t}\n"
1290
1291         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1292
1293         if res_map.java_hu_ty != "void":
1294             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1295         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1296         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1297         if res_map.java_hu_ty == "void":
1298             pass
1299         elif res_map.to_hu_conv is not None:
1300             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1301             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1302             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1303         else:
1304             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1305         java_hu_struct += "\t\t}\n"
1306         java_hu_struct += "\t}\n\n"
1307
1308         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1309         if err_map.java_hu_ty != "void":
1310             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1311         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1312         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1313         if err_map.java_hu_ty == "void":
1314             pass
1315         elif err_map.to_hu_conv is not None:
1316             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1317             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1318             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1319         else:
1320             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1321         java_hu_struct += "\t\t}\n"
1322
1323         java_hu_struct += "\t}\n\n"
1324         return java_hu_struct
1325
1326     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):
1327         out_java = ""
1328         out_c = ""
1329         out_java_struct = None
1330
1331         out_java += ("\tpublic static native ")
1332         out_c += (self.c_fn_ty_pfx)
1333         out_c += (return_type_info.c_ty)
1334         out_java += (return_type_info.java_ty)
1335         if return_type_info.ret_conv is not None:
1336             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1337         out_java += (" " + method_name + "(")
1338         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1339         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1340
1341         for idx, arg_conv_info in enumerate(argument_types):
1342             if idx != 0:
1343                 out_java += (", ")
1344                 out_c += (", ")
1345             if arg_conv_info.c_ty != "void":
1346                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1347                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1348
1349         out_java_struct = ""
1350         extra_java_struct_out = ""
1351         if not args_known:
1352             out_java_struct += ("\t// Skipped " + method_name + "\n")
1353         else:
1354             if doc_comment is not None:
1355                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1356             if return_type_info.nullable:
1357                 out_java_struct += "\t@Nullable\n"
1358             if not takes_self:
1359                 if meth_n == "new":
1360                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1361                 elif meth_n == "default":
1362                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1363                 else:
1364                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1365             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1366                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1367             else:
1368                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1369                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1370                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1371                     extra_java_struct_out += "\t}\n"
1372                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1373                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1374                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1375                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1376                     extra_java_struct_out += "\t}\n"
1377                 if meth_n == "wait":
1378                     meth_n = "wait_indefinite"
1379                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1380             for idx, arg in enumerate(argument_types):
1381                 if idx != 0:
1382                     if not takes_self or idx > 1:
1383                         out_java_struct += ", "
1384                 elif takes_self:
1385                     continue
1386                 if arg.java_ty != "void":
1387                     if arg.arg_name in default_constructor_args:
1388                         assert not arg.nullable
1389                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1390                             if explode_idx != 0:
1391                                 out_java_struct += (", ")
1392                             out_java_struct += (
1393                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1394                     else:
1395                         if arg.nullable:
1396                             out_java_struct += "@Nullable "
1397                         ty_string = self.fully_qualified_hu_ty_path(arg)
1398                         out_java_struct += ty_string + " " + arg.arg_name
1399         out_java += (");\n")
1400         out_c += (") {\n")
1401         if out_java_struct is not None:
1402             out_java_struct += (") {\n")
1403         for info in argument_types:
1404             if info.arg_conv is not None:
1405                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1406         if return_type_info.ret_conv is not None:
1407             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1408         elif return_type_info.c_ty != "void":
1409             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1410         else:
1411             out_c += ("\t")
1412         if c_call_string is None:
1413             out_c += (method_name + "(")
1414         else:
1415             out_c += (c_call_string)
1416         for idx, info in enumerate(argument_types):
1417             if info.arg_conv_name is not None:
1418                 if idx != 0:
1419                     out_c += (", ")
1420                 elif c_call_string is not None:
1421                     continue
1422                 out_c += (info.arg_conv_name)
1423         out_c += (")")
1424         if return_type_info.ret_conv is not None:
1425             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1426         else:
1427             out_c += (";")
1428         for info in argument_types:
1429             if info.arg_conv_cleanup is not None:
1430                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1431         if return_type_info.ret_conv is not None:
1432             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1433         elif return_type_info.c_ty != "void":
1434             out_c += ("\n\treturn ret_val;")
1435         out_c += ("\n}\n\n")
1436
1437         if args_known:
1438             out_java_struct += ("\t\t")
1439             if return_type_info.java_ty != "void":
1440                 out_java_struct += (return_type_info.java_ty + " ret = ")
1441             out_java_struct += ("bindings." + method_name + "(")
1442             for idx, info in enumerate(argument_types):
1443                 if idx != 0:
1444                     out_java_struct += (", ")
1445                 if idx == 0 and takes_self:
1446                     out_java_struct += ("this.ptr")
1447                 elif info.arg_name in default_constructor_args:
1448                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1449                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1450                         if explode_idx != 0:
1451                             out_java_struct += (", ")
1452                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1453                         if explode_arg.from_hu_conv is not None:
1454                             out_java_struct += (
1455                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1456                         else:
1457                             out_java_struct += (expl_arg_name)
1458                     out_java_struct += (")")
1459                 elif info.from_hu_conv is not None:
1460                     out_java_struct += (info.from_hu_conv[0])
1461                 else:
1462                     out_java_struct += (info.arg_name)
1463             out_java_struct += (");\n")
1464
1465             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1466             # the stack, calling its finalizer immediately even if member methods are *actively
1467             # executing* on the same object, as long as said object is on the stack. There is no
1468             # concrete specification for when the optimizer is allowed to do this, and when it is
1469             # not, so there is absolutely no way to be certain that this fix suffices.
1470             #
1471             # Instead, the "Java Language Specification" says only that an object is reachable
1472             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1473             # computation from any live thread". To any sensible reader this would mean actively
1474             # executing a member function on an object would make it not eligible for finalization.
1475             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1476             # very explicitly in fact, but those are just, like, words, man.
1477             #
1478             # In the seemingly non-normative text further down, a few examples of things the
1479             # optimizer can do are given, including "if the values in an object's fields are
1480             # stored in registers[, t]he may then access the registers instead of the object, and
1481             # never access the object again[, implying] that the object is garbage". This appears
1482             # to fully contradict both the above statement, the API documentation in java.lang.ref
1483             # regarding when a reference is "strongly reachable", and basic common sense. There is
1484             # no concrete set of limitations stated, however, seemingly implying the JIT could
1485             # decide your code would run faster by simply garbage collecting everything
1486             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1487             # entirely flying blind here. We add some fences and hope that its sufficient, but
1488             # with no specification to rely on, we cannot be certain of anything.
1489             #
1490             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1491             # object will be considered available for garbage collection once the JIT kicks in, so
1492             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1493             for idx, info in enumerate(argument_types):
1494                 if idx == 0 and takes_self:
1495                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1496                 elif info.arg_name in default_constructor_args:
1497                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1498                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1499                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1500                 elif info.c_ty != "void":
1501                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1502
1503             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1504                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1505
1506             if return_type_info.to_hu_conv is not None:
1507                 if not takes_self:
1508                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1509                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1510                 else:
1511                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1512
1513             for idx, info in enumerate(argument_types):
1514                 if idx == 0 and takes_self:
1515                     pass
1516                 elif info.arg_name in default_constructor_args:
1517                     for explode_arg in default_constructor_args[info.arg_name]:
1518                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1519                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1520                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1521                                                                                                expl_arg_name).replace(
1522                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1523                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1524                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1525                         out_java_struct += (
1526                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1527                     else:
1528                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1529
1530             if takes_self and not takes_self_as_ref:
1531                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1532             if return_type_info.to_hu_conv_name is not None:
1533                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1534             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1535                 out_java_struct += ("\t\treturn ret;\n")
1536             out_java_struct += ("\t}\n\n")
1537
1538         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1539
1540     def cleanup(self):
1541         pass