Make TxOut language-specific, fix typescript UtilMethods compilation
[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
9 class Consts:
10     def __init__(self, DEBUG: bool, target: Target, **kwargs):
11         self.target = target
12         self.c_array_class_caches = set()
13         self.c_type_map = dict(
14             uint8_t = ['byte'],
15             uint16_t = ['short'],
16             uint32_t = ['int'],
17             uint64_t = ['long'],
18         )
19
20         self.to_hu_conv_templates = dict(
21             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}); }',
22             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}); }'
23         )
24
25         self.bindings_header = """package org.ldk.impl;
26 import org.ldk.enums.*;
27 import org.ldk.impl.version;
28 import java.io.File;
29 import java.io.InputStream;
30 import java.io.IOException;
31 import java.nio.file.Files;
32 import java.nio.file.Path;
33 import java.nio.file.StandardCopyOption;
34
35 public class bindings {
36         public static class VecOrSliceDef {
37                 public long dataptr;
38                 public long datalen;
39                 public long stride;
40                 public VecOrSliceDef(long dataptr, long datalen, long stride) {
41                         this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
42                 }
43         }
44         static {
45                 try {
46                         // Try to load natively first, this works on Android and in testing.
47                         System.loadLibrary(\"lightningjni\");
48                 } catch (UnsatisfiedLinkError system_load_err) {
49                         // Otherwise try to load from the library jar.
50                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
51                         tmpdir.mkdir(); // If it fails to create, assume it was there already
52                         tmpdir.deleteOnExit();
53                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
54                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
55                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
56                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
57                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
58                                 Runtime.getRuntime().load(libpath.toString());
59                         } catch (Exception e) {
60                                 System.err.println("Failed to load LDK native library.");
61                                 System.err.println("System LDK native library load failed with: " + system_load_err);
62                                 System.err.println("Resource-based LDK native library load failed with: " + e);
63                                 throw new IllegalArgumentException(e);
64                         }
65                 }
66                 init(java.lang.Enum.class, VecOrSliceDef.class);
67                 init_class_cache();
68                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
69                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
70                 // Fetching the LDK versions from C also checks that the header and binaries match
71                 get_ldk_c_bindings_version();
72                 get_ldk_version();
73         }
74         static native void init(java.lang.Class c, java.lang.Class slicedef);
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         public static native boolean deref_bool(long ptr);
82         public static native long deref_long(long ptr);
83         public static native void free_heap_ptr(long ptr);
84         public static native byte[] read_bytes(long ptr, long len);
85         public static native byte[] get_u8_slice_bytes(long slice_ptr);
86         public static native long bytes_to_u8_vec(byte[] bytes);
87         public static native long new_txpointer_copy_data(byte[] txdata);
88         public static native void txpointer_free(long ptr);
89         public static native byte[] txpointer_get_buffer(long ptr);
90         public static native long vec_slice_len(long vec);
91         public static native long new_empty_slice_vec();
92
93 """
94         self.bindings_version_file = """package org.ldk.impl;
95
96 public class version {
97         public static String get_ldk_java_bindings_version() {
98                 return "<git_version_ldk_garbagecollected>";
99         }
100 }"""
101
102         self.bindings_footer = "}\n"
103
104         self.util_fn_pfx = """package org.ldk.structs;
105 import org.ldk.impl.bindings;
106 import org.ldk.enums.*;
107 import org.ldk.util.*;
108 import java.util.Arrays;
109 import java.lang.ref.Reference;
110 import javax.annotation.Nullable;
111
112 public class UtilMethods {
113 """
114         self.util_fn_sfx = "}"
115         self.common_base = """package org.ldk.structs;
116 import java.util.LinkedList;
117 class CommonBase {
118         long ptr;
119         LinkedList<Object> ptrs_to = new LinkedList();
120         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
121 }
122 """
123
124         self.txout_defn = """public class TxOut extends CommonBase {
125         /** The script_pubkey in this output */
126         public final byte[] script_pubkey;
127         /** The value, in satoshis, of this output */
128         public final long value;
129
130         TxOut(java.lang.Object _dummy, long ptr) {
131                 super(ptr);
132                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
133                 this.value = bindings.TxOut_get_value(ptr);
134         }
135         public TxOut(long value, byte[] script_pubkey) {
136                 super(bindings.TxOut_new(script_pubkey, value));
137                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
138                 this.value = bindings.TxOut_get_value(ptr);
139         }
140
141         @Override @SuppressWarnings(\"deprecation\")
142         protected void finalize() throws Throwable {
143                 super.finalize();
144                 if (ptr != 0) { bindings.TxOut_free(ptr); }
145         }
146 }"""
147
148         self.c_file_pfx = """#include <jni.h>
149 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
150 #define int64_t jlong
151 #include \"org_ldk_impl_bindings.h\"
152 #include <lightning.h>
153 #include <string.h>
154 #include <stdatomic.h>
155 #include <stdlib.h>
156
157 #define LIKELY(v) __builtin_expect(!!(v), 1)
158 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
159
160 """
161
162         if self.target == Target.ANDROID:
163             self.c_file_pfx = self.c_file_pfx + """
164 #include <android/log.h>
165 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
166
167 #include <unistd.h>
168 #include <pthread.h>
169 static void* redirect_stderr(void* ignored) {
170         int pipes[2];
171         pipe(pipes);
172         dup2(pipes[1], STDERR_FILENO);
173         char buf[8192];
174         memset(buf, 0, 8192);
175         ssize_t len;
176         while ((len = read(pipes[0], buf, 8191)) > 0) {
177                 DEBUG_PRINT("%s\\n", buf);
178                 memset(buf, 0, 8192);
179         }
180         DEBUG_PRINT("End of stderr???\\n");
181         return 0;
182 }
183 void __attribute__((constructor)) spawn_stderr_redirection() {
184         pthread_t thread;
185         pthread_create(&thread, NULL, &redirect_stderr, NULL);
186 }
187 """
188         else:
189             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
190
191         if not DEBUG or sys.platform == "darwin":
192             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
193 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
194 #define CHECK_ACCESS(p)
195 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
196 """
197         if not DEBUG:
198             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
199 #define CHECK(a)
200 """
201         if DEBUG:
202             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
203 // Always run a, then assert it is true:
204 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
205 // Assert a is true or do nothing
206 #define CHECK(a) DO_ASSERT(a)
207
208 void __attribute__((constructor)) debug_log_version() {
209         if (check_get_ldk_version() == NULL)
210                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
211         if (check_get_ldk_bindings_version() == NULL)
212                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
213         DEBUG_PRINT("Loaded LDK-Java Bindings with LDK %s and LDK-C-Bindings %s\\n", check_get_ldk_version(), check_get_ldk_bindings_version());
214 }
215 """
216
217             if sys.platform != "darwin":
218                 self.c_file_pfx += """
219 // Running a leak check across all the allocations and frees of the JDK is a mess,
220 // so instead we implement our own naive leak checker here, relying on the -wrap
221 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
222 // and free'd in Rust or C across the generated bindings shared library.
223 #include <threads.h>
224 """
225
226                 if self.target == Target.ANDROID:
227                     self.c_file_pfx = self.c_file_pfx + """
228 #include <unwind.h>
229 #include <dlfcn.h>
230
231 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
232 // symbols, so we only use it on Android, where execinfo.h is unavailable.
233
234 struct BacktraceState {
235         void** current;
236         void** end;
237 };
238 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
239         struct BacktraceState* state = (struct BacktraceState*)arg;
240         uintptr_t pc = _Unwind_GetIP(context);
241         if (pc) {
242                 if (state->current == state->end) {
243                         return _URC_END_OF_STACK;
244                 } else {
245                         *state->current++ = (void*)(pc);
246                 }
247         }
248         return _URC_NO_REASON;
249 }
250
251 int backtrace(void** buffer, int max) {
252         struct BacktraceState state = { buffer, buffer + max };
253         _Unwind_Backtrace(unwind_callback, &state);
254         return state.current - buffer;
255 }
256
257 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
258         for (int idx = 0; idx < count; ++idx) {
259                 Dl_info info;
260                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
261                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
262                 } else {
263                         DEBUG_PRINT("%p: ???", buffer[idx]);
264                 }
265         }
266 }
267 """
268                 else:
269                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
270                 self.c_file_pfx = self.c_file_pfx + """
271 #include <unistd.h>
272 #include <pthread.h>
273 static pthread_mutex_t allocation_mtx;
274
275 void __attribute__((constructor)) init_mtx() {
276         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
277 }
278
279 #define BT_MAX 128
280 typedef struct allocation {
281         struct allocation* next;
282         void* ptr;
283         const char* struct_name;
284         void* bt[BT_MAX];
285         int bt_len;
286         unsigned long alloc_len;
287 } allocation;
288 static allocation* allocation_ll = NULL;
289
290 void* __real_malloc(size_t len);
291 void* __real_calloc(size_t nmemb, size_t len);
292 static void new_allocation(void* res, const char* struct_name, size_t len) {
293         allocation* new_alloc = __real_malloc(sizeof(allocation));
294         new_alloc->ptr = res;
295         new_alloc->struct_name = struct_name;
296         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
297         new_alloc->alloc_len = len;
298         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
299         new_alloc->next = allocation_ll;
300         allocation_ll = new_alloc;
301         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
302 }
303 static void* MALLOC(size_t len, const char* struct_name) {
304         void* res = __real_malloc(len);
305         new_allocation(res, struct_name, len);
306         return res;
307 }
308 void __real_free(void* ptr);
309 static void alloc_freed(void* ptr) {
310         allocation* p = NULL;
311         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
312         allocation* it = allocation_ll;
313         while (it->ptr != ptr) {
314                 p = it; it = it->next;
315                 if (it == NULL) {
316                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
317                         void* bt[BT_MAX];
318                         int bt_len = backtrace(bt, BT_MAX);
319                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
320                         DEBUG_PRINT("\\n\\n");
321                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
322                         return; // addrsan should catch malloc-unknown and print more info than we have
323                 }
324         }
325         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
326         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
327         DO_ASSERT(it->ptr == ptr);
328         __real_free(it);
329 }
330 static void FREE(void* ptr) {
331         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
332         alloc_freed(ptr);
333         __real_free(ptr);
334 }
335
336 void* __wrap_malloc(size_t len) {
337         void* res = __real_malloc(len);
338         new_allocation(res, "malloc call", len);
339         return res;
340 }
341 void* __wrap_calloc(size_t nmemb, size_t len) {
342         void* res = __real_calloc(nmemb, len);
343         new_allocation(res, "calloc call", len);
344         return res;
345 }
346 void __wrap_free(void* ptr) {
347         if (ptr == NULL) return;
348         alloc_freed(ptr);
349         __real_free(ptr);
350 }
351
352 static void CHECK_ACCESS(const void* ptr) {
353         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
354         allocation* it = allocation_ll;
355         while (it->ptr != ptr) {
356                 it = it->next;
357                 if (it == NULL) {
358                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
359                         void* bt[BT_MAX];
360                         int bt_len = backtrace(bt, BT_MAX);
361                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
362                         DEBUG_PRINT("\\n\\n");
363                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
364                         return; // addrsan should catch and print more info than we have
365                 }
366         }
367         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
368 }
369 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
370         if (v.is_owned && v.inner != NULL) { \\
371                 const void *p = __unmangle_inner_ptr(v.inner); \\
372                 if (p != NULL) { \\
373                         CHECK_ACCESS(p); \\
374                 } \\
375         }
376
377 void* __real_realloc(void* ptr, size_t newlen);
378 void* __wrap_realloc(void* ptr, size_t len) {
379         if (ptr != NULL) alloc_freed(ptr);
380         void* res = __real_realloc(ptr, len);
381         new_allocation(res, "realloc call", len);
382         return res;
383 }
384 void __wrap_reallocarray(void* ptr, size_t new_sz) {
385         // Rust doesn't seem to use reallocarray currently
386         DO_ASSERT(false);
387 }
388
389 void __attribute__((destructor)) check_leaks() {
390         unsigned long alloc_count = 0;
391         unsigned long alloc_size = 0;
392         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
393         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
394         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
395         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
396                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
397                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
398                 DEBUG_PRINT("\\n\\n");
399                 alloc_count++;
400                 alloc_size += a->alloc_len;
401         }
402         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
403         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
404         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
405 }
406 """
407         self.c_file_pfx = self.c_file_pfx + """
408 static jmethodID ordinal_meth = NULL;
409 static jmethodID slicedef_meth = NULL;
410 static jclass slicedef_cls = NULL;
411 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
412         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
413         CHECK(ordinal_meth != NULL);
414         slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
415         CHECK(slicedef_meth != NULL);
416         slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
417         CHECK(slicedef_cls != NULL);
418 }
419
420 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
421         return *((bool*)ptr);
422 }
423 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
424         return *((long*)ptr);
425 }
426 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
427         FREE((void*)ptr);
428 }
429 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * env, jclass _b, jlong ptr, jlong len) {
430         jbyteArray ret_arr = (*env)->NewByteArray(env, len);
431         (*env)->SetByteArrayRegion(env, ret_arr, 0, len, (unsigned char*)ptr);
432         return ret_arr;
433 }
434 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * env, jclass _b, jlong slice_ptr) {
435         LDKu8slice *slice = (LDKu8slice*)slice_ptr;
436         jbyteArray ret_arr = (*env)->NewByteArray(env, slice->datalen);
437         (*env)->SetByteArrayRegion(env, ret_arr, 0, slice->datalen, slice->data);
438         return ret_arr;
439 }
440 JNIEXPORT int64_t impl_bindings_bytes_1to_1u8_1vec (JNIEnv * env, jclass _b, jbyteArray bytes) {
441         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
442         vec->datalen = (*env)->GetArrayLength(env, bytes);
443         vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
444         (*env)->GetByteArrayRegion (env, bytes, 0, vec->datalen, vec->data);
445         return (uint64_t)vec;
446 }
447 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_txpointer_1get_1buffer (JNIEnv * env, jclass _b, jlong ptr) {
448         LDKTransaction *txdata = (LDKTransaction*)ptr;
449         LDKu8slice slice;
450         slice.data = txdata->data;
451         slice.datalen = txdata->datalen;
452         return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (uint64_t)&slice);
453 }
454 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
455         LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
456         txdata->datalen = (*env)->GetArrayLength(env, bytes);
457         txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
458         txdata->data_is_owned = false;
459         (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
460         return (uint64_t)txdata;
461 }
462 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
463         LDKTransaction *tx = (LDKTransaction*)ptr;
464         tx->data_is_owned = true;
465         Transaction_free(*tx);
466         FREE((void*)ptr);
467 }
468 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
469         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
470         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
471         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
472         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");
473         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_C2Tuple_usizeTransactionZZ, datalen), "Vec<*> needs to be mapped identically");
474         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
475         return (uint64_t)vec->datalen;
476 }
477 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * env, jclass _b) {
478         // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
479         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
480         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
481         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
482         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
483         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
484         vec->data = NULL;
485         vec->datalen = 0;
486         return (uint64_t)vec;
487 }
488
489 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
490 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
491 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
492 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
493
494 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
495 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
496 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
497
498 typedef jlongArray int64_tArray;
499 typedef jbyteArray int8_tArray;
500
501 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
502         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
503         char* conv_buf = MALLOC(len + 1, "str conv buf");
504         memcpy(conv_buf, chars, len);
505         conv_buf[len] = 0;
506         jstring ret = (*env)->NewStringUTF(env, conv_buf);
507         FREE(conv_buf);
508         return ret;
509 }
510 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
511         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
512         char* newchars = MALLOC(str_len + 1, "String chars");
513         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
514         memcpy(newchars, jchars, str_len);
515         newchars[str_len] = 0;
516         (*env)->ReleaseStringUTFChars(env, str, jchars);
517         LDKStr res = {
518                 .chars = newchars,
519                 .len = str_len,
520                 .chars_is_owned = true
521         };
522         return res;
523 }
524
525 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
526         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
527 }
528 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
529         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
530 }
531 #include "version.c"
532 """
533         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
534         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
535 }"""
536
537         self.hu_struct_file_prefix = """package org.ldk.structs;
538
539 import org.ldk.impl.bindings;
540 import org.ldk.enums.*;
541 import org.ldk.util.*;
542 import java.util.Arrays;
543 import java.lang.ref.Reference;
544 import javax.annotation.Nullable;
545
546 """
547         self.c_fn_ty_pfx = "JNIEXPORT "
548         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
549         self.file_ext = ".java"
550         self.ptr_c_ty = "int64_t"
551         self.ptr_native_ty = "long"
552         self.result_c_ty = "jclass"
553         self.ptr_arr = "jobjectArray"
554         self.is_arr_some_check = ("", " != NULL")
555         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
556
557     def construct_jenv(self):
558         res =  "JNIEnv *env;\n"
559         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
560         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
561         if self.target == Target.ANDROID:
562             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
563         else:
564             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
565         res += "} else {\n"
566         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
567         res += "}\n"
568         return res
569     def deconstruct_jenv(self):
570         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
571         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
572         res += "}\n"
573         return res
574
575     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
576         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
577             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
578         return None
579     def create_native_arr_call(self, arr_len, ty_info):
580         if ty_info.c_ty == "int8_tArray":
581             return "(*env)->NewByteArray(env, " + arr_len + ")"
582         elif ty_info.subty.c_ty.endswith("Array"):
583             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
584             self.c_array_class_caches.add(clz_var)
585             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
586         else:
587             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
588     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
589         if ty_info.c_ty == "int8_tArray":
590             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
591         else:
592             assert False
593     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
594         if ty_info.c_ty == "int8_tArray":
595             if copy:
596                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
597             else:
598                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
599         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
600             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
601         else:
602             return None
603     def get_native_arr_elem(self, arr_name, idxc, ty_info):
604         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
605             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
606         else:
607             assert False # Only called if above is None
608     def get_native_arr_ptr_call(self, ty_info):
609         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
610             return None
611         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
612     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
613         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
614             return None
615         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
616     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
617         if ty_info.c_ty == "int8_tArray":
618             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
619         else:
620             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
621
622     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
623         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
624             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
625         elif elem_ty.java_ty == "long":
626             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
627         else:
628             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
629
630     def str_ref_to_native_call(self, var_name, str_len):
631         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
632     def str_ref_to_c_call(self, var_name):
633         return "java_to_owned_str(env, " + var_name + ")"
634
635     def c_fn_name_define_pfx(self, fn_name, has_args):
636         if has_args:
637             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
638         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
639
640     def init_str(self):
641         res = ""
642         for ty in sorted(self.c_array_class_caches):
643             res = res + "static jclass " + ty + "_clz = NULL;\n"
644         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
645         for ty in sorted(self.c_array_class_caches):
646             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
647             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
648             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
649         res = res + "}\n"
650         return res
651
652     def var_decl_statement(self, ty_string, var_name, statement):
653         return ty_string + " " + var_name + " = " + statement
654
655     def for_n_in_range(self, n, minimum, maximum):
656         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
657     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
658         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
659
660     def get_ptr(self, var):
661         return var + ".ptr"
662     def set_null_skip_free(self, var):
663         return var + ".ptr" + " = 0;"
664
665     def add_ref(self, holder, referent):
666         return holder + ".ptrs_to.add(" + referent + ")"
667
668     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
669         out_java_enum = "package org.ldk.enums;\n\n"
670         out_java = ""
671         out_c = ""
672         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
673         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
674         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
675         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
676         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
677         out_c += "\t}\n"
678         out_c += "\tswitch (ord) {\n"
679
680         if enum_doc_comment is not None:
681             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
682         out_java_enum += "public enum " + struct_name + " {\n"
683         ord_v = 0
684         for var, var_docs in variants:
685             if var_docs is not None:
686                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
687             out_java_enum += "\t" + var + ",\n"
688             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
689             ord_v = ord_v + 1
690         out_java_enum = out_java_enum + "\t; static native void init();\n"
691         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
692         out_java_enum = out_java_enum + "}"
693         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
694         out_c += "\t}\n"
695         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
696         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
697         out_c += "}\n"
698
699         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
700         for var, _ in variants:
701             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
702         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"
703         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
704         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
705         for var, _ in variants:
706             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
707             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
708         out_c = out_c + "}\n"
709         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
710         out_c = out_c + "\tswitch (val) {\n"
711         ord_v = 0
712         for var, _ in variants:
713             out_c = out_c + "\t\tcase " + var + ":\n"
714             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
715             ord_v = ord_v + 1
716         out_c = out_c + "\t\tdefault: abort();\n"
717         out_c = out_c + "\t}\n"
718         out_c = out_c + "}\n\n"
719
720         return (out_c, out_java_enum, out_java)
721
722     def c_unitary_enum_to_native_call(self, ty_info):
723         return (ty_info.rust_obj + "_to_java(env, ", ")")
724     def native_unitary_enum_to_c_call(self, ty_info):
725         return (ty_info.rust_obj + "_from_java(env, ", ")")
726
727     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
728         out_c = ""
729         for var in variants:
730             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
731             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
732         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"
733         for var_name in variants:
734             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
735             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
736             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
737             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"
738             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
739         out_c = out_c + "}\n"
740         return out_c
741
742     def c_complex_enum_pass_ty(self, struct_name):
743         return "jobject"
744
745     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
746         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
747         for param in c_params:
748             ret = ret + ", " + param
749         return ret + ")"
750
751     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
752         out_java_trait = ""
753         out_java = ""
754
755         # First generate most of the Java code, note that we need information about java method argument strings for C
756         out_java_trait = out_java_trait + self.hu_struct_file_prefix
757         if trait_doc_comment is not None:
758             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
759         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
760         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
761         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
762         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
763         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
764         for var in flattened_field_vars:
765             if isinstance(var, ConvInfo):
766                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
767             else:
768                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
769         out_java_trait = out_java_trait + ") {\n"
770         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
771         for var in flattened_field_vars:
772             if isinstance(var, ConvInfo):
773                 if var.from_hu_conv is not None:
774                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
775                 else:
776                     out_java_trait = out_java_trait + ", " + var.arg_name
777             else:
778                 out_java_trait = out_java_trait + ", " + var[1]
779         out_java_trait = out_java_trait + "));\n"
780         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
781         for var in flattened_field_vars:
782             if isinstance(var, ConvInfo):
783                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
784                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
785             else:
786                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
787         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
788         out_java_trait = out_java_trait + "\t}\n"
789         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
790         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
791         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
792         out_java_trait = out_java_trait + "\t}\n\n"
793
794         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
795         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
796         for var in flattened_field_vars:
797             if isinstance(var, ConvInfo):
798                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
799             else:
800                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
801                 # Java-implemented version, so we require users pass a Java implementation here :/
802                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
803         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
804         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
805         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
806         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
807         java_meths = []
808         for fn_line in field_fns:
809             java_meth_descr = "("
810             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
811                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
812                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
813                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
814                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
815
816                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
817                     if idx >= 1:
818                         out_java = out_java + ", "
819                         java_trait_constr = java_trait_constr + ", "
820                         out_java_trait = out_java_trait + ", "
821                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
822                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
823                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
824                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
825                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
826                 java_meths.append((fn_line.fn_name, java_meth_descr))
827
828                 out_java = out_java + ");\n"
829                 out_java_trait = out_java_trait + ");\n"
830                 java_trait_constr = java_trait_constr + ") {\n"
831
832                 for arg_info in fn_line.args_ty:
833                     if arg_info.to_hu_conv is not None:
834                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
835
836                 if fn_line.ret_ty_info.java_ty != "void":
837                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
838                 else:
839                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
840
841                 for idx, arg_info in enumerate(fn_line.args_ty):
842                     if idx != 0:
843                         java_trait_constr = java_trait_constr + ", "
844                     if arg_info.to_hu_conv_name is not None:
845                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
846                     else:
847                         java_trait_constr = java_trait_constr + arg_info.arg_name
848
849                 java_trait_constr = java_trait_constr + ");\n"
850                 if fn_line.ret_ty_info.java_ty != "void":
851                     if fn_line.ret_ty_info.from_hu_conv is not None:
852                         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"
853                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
854                             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"
855                         #if fn_line.ret_ty_info.rust_obj in result_types:
856                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
857                     else:
858                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
859                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
860         java_trait_constr = java_trait_constr + "\t\t}"
861         for var in field_vars:
862             if isinstance(var, ConvInfo):
863                 java_trait_constr = java_trait_constr + ", " + var.arg_name
864             else:
865                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
866                 for suparg in var[2]:
867                     if isinstance(suparg, ConvInfo):
868                         java_trait_constr += ", " + suparg.arg_name
869                     else:
870                         java_trait_constr += ", " + suparg[1]
871                 java_trait_constr += ").bindings_instance"
872                 for suparg in var[2]:
873                     if isinstance(suparg, ConvInfo):
874                         java_trait_constr += ", " + suparg.arg_name
875                     else:
876                         java_trait_constr += ", " + suparg[1]
877         out_java_trait = out_java_trait + "\t}\n"
878         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
879
880         out_java = out_java + "\t}\n"
881
882         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
883         for var in flattened_field_vars:
884             if isinstance(var, ConvInfo):
885                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
886             else:
887                 out_java = out_java + ", " + var[0] + " " + var[1]
888         out_java = out_java + ");\n"
889
890         # Now that we've written out our java code (and created java_meths), generate C
891         out_c = "typedef struct " + struct_name + "_JCalls {\n"
892         out_c = out_c + "\tatomic_size_t refcnt;\n"
893         out_c = out_c + "\tJavaVM *vm;\n"
894         out_c = out_c + "\tjweak o;\n"
895         for var in flattened_field_vars:
896             if isinstance(var, ConvInfo):
897                 # We're a regular ol' field
898                 pass
899             else:
900                 # We're a supertrait
901                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
902         for fn in field_fns:
903             if fn.fn_name != "free" and fn.fn_name != "cloned":
904                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
905         out_c = out_c + "} " + struct_name + "_JCalls;\n"
906
907         for fn_line in field_fns:
908             if fn_line.fn_name == "free":
909                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
910                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
911                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
912                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
913                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
914                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
915                 out_c = out_c + "\t\tFREE(j_calls);\n"
916                 out_c = out_c + "\t}\n}\n"
917
918         for idx, fn_line in enumerate(field_fns):
919             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
920                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
921                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
922                 if fn_line.self_is_const:
923                     out_c = out_c + "const void* this_arg"
924                 else:
925                     out_c = out_c + "void* this_arg"
926
927                 for idx, arg in enumerate(fn_line.args_ty):
928                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
929
930                 out_c = out_c + ") {\n"
931                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
932                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
933
934                 for arg_info in fn_line.args_ty:
935                     if arg_info.ret_conv is not None:
936                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
937                         out_c = out_c + arg_info.arg_name
938                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
939
940                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
941                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
942                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
943                 elif fn_line.ret_ty_info.c_ty == "void":
944                     out_c += "\t(*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
945                 elif fn_line.ret_ty_info.java_ty == "String":
946                     # Manually write out String methods as they're just an Object
947                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
948                 elif not fn_line.ret_ty_info.passed_as_ptr:
949                     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"
950                 else:
951                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
952
953                 for idx, arg_info in enumerate(fn_line.args_ty):
954                     if arg_info.ret_conv is not None:
955                         out_c = out_c + ", " + arg_info.ret_conv_name
956                     else:
957                         out_c = out_c + ", " + arg_info.arg_name
958                 out_c = out_c + ");\n"
959
960                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
961                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
962                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
963                 out_c += "\t}\n"
964
965                 if fn_line.ret_ty_info.arg_conv is not None:
966                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
967                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
968                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
969                 else:
970                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
971                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
972                         out_c += "\treturn ret;\n"
973
974                 out_c = out_c + "}\n"
975
976         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
977         can_clone_with_ptr = True
978         for var in field_vars:
979             if isinstance(var, ConvInfo):
980                 can_clone_with_ptr = False
981         if can_clone_with_ptr:
982             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
983             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
984             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
985             for var in field_vars:
986                 if not isinstance(var, ConvInfo):
987                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
988             out_c = out_c + "}\n"
989
990         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
991         for var in flattened_field_vars:
992             if isinstance(var, ConvInfo):
993                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
994             else:
995                 out_c = out_c + ", jobject " + var[1]
996         out_c = out_c + ") {\n"
997
998         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
999         out_c = out_c + "\tCHECK(c != NULL);\n"
1000         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
1001         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
1002         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
1003         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
1004
1005         for (fn_name, java_meth_descr) in java_meths:
1006             if fn_name != "free" and fn_name != "cloned":
1007                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
1008                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
1009
1010         for var in flattened_field_vars:
1011             if isinstance(var, ConvInfo) and var.arg_conv is not None:
1012                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
1013         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
1014         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
1015         for fn_line in field_fns:
1016             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1017                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1018             elif fn_line.fn_name == "free":
1019                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1020             else:
1021                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1022         for var in field_vars:
1023             if isinstance(var, ConvInfo):
1024                 if var.arg_conv_name is not None:
1025                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1026                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1027                 else:
1028                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1029                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1030             else:
1031                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1032                 for suparg in var[2]:
1033                     if isinstance(suparg, ConvInfo):
1034                         out_c = out_c + ", " + suparg.arg_name
1035                     else:
1036                         out_c = out_c + ", " + suparg[1]
1037                 out_c += "),\n"
1038         out_c = out_c + "\t};\n"
1039         for var in flattened_field_vars:
1040             if not isinstance(var, ConvInfo):
1041                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
1042         out_c = out_c + "\treturn ret;\n"
1043         out_c = out_c + "}\n"
1044
1045         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "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         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1053         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1054         for var in flattened_field_vars:
1055             if isinstance(var, ConvInfo):
1056                 out_c = out_c + ", " + var.arg_name
1057             else:
1058                 out_c = out_c + ", " + var[1]
1059         out_c = out_c + ");\n"
1060         out_c = out_c + "\treturn (uint64_t)res_ptr;\n"
1061         out_c = out_c + "}\n"
1062
1063         for var in flattened_field_vars:
1064             if not isinstance(var, ConvInfo):
1065                 out_java_trait += "\n\t/**\n"
1066                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1067                 out_java_trait += "\t */\n"
1068                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1069                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1070                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1071                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
1072                 out_java_trait += "\t\treturn res;\n"
1073                 out_java_trait += "\t}\n"
1074                 out_java_trait += "\n"
1075
1076                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1077
1078                 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"
1079                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)(arg & ~1);\n"
1080                 out_c += "\tuint64_t res_ptr = (uint64_t)&inp->" + var[1] + ";\n"
1081                 out_c += "\tDO_ASSERT((res_ptr & 1) == 0);\n"
1082                 out_c += "\treturn (int64_t)(res_ptr | 1);\n"
1083                 out_c += "}\n"
1084
1085         return (out_java, out_java_trait, out_c)
1086
1087     def trait_struct_inc_refcnt(self, ty_info):
1088         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1089         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1090         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1091         return base_conv
1092
1093     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1094         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1095         out_java_enum = ""
1096         out_java = ""
1097         out_c = ""
1098
1099         out_java_enum += (self.hu_struct_file_prefix)
1100         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1101         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1102         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1103         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1104         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1105         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1106         out_java_enum += ("\t\tsuper.finalize();\n")
1107         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1108         out_java_enum += ("\t}\n")
1109         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1110         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1111         java_hu_subclasses = ""
1112
1113         init_meth_jty_strs = {}
1114
1115         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1116         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1117         for var in variant_list:
1118             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1119             if var.var_docs is not None:
1120                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1121             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1122             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1123             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1124             init_meth_jty_str = ""
1125             init_meth_params = ""
1126             init_meth_body = ""
1127             hu_conv_body = ""
1128             for idx, (field_ty, field_docs) in enumerate(var.fields):
1129                 if idx > 0:
1130                     init_meth_params = init_meth_params + ", "
1131
1132                 if field_ty.java_hu_ty == var.var_name:
1133                     field_path = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1134                     out_java += "\t\t\tpublic " + field_path + " " + field_ty.arg_name + ";\n"
1135                     java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_path + " " + field_ty.arg_name + ";\n"
1136                     init_meth_params = init_meth_params + field_path + " " + field_ty.arg_name
1137                 else:
1138                     out_java += "\t\t\tpublic " + field_ty.java_ty + " " + field_ty.arg_name + ";\n"
1139                     if field_docs is not None:
1140                         java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1141                     java_hu_subclasses += "\t\t"
1142                     if field_ty.nullable:
1143                         java_hu_subclasses += "@Nullable "
1144                     java_hu_subclasses += "public final " + field_ty.java_hu_ty + " " + field_ty.arg_name + ";\n"
1145                     init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.arg_name
1146                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1147                 if field_ty.to_hu_conv is not None:
1148                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1149                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1150                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1151                 else:
1152                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1153                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1154             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1155             out_java +=  (init_meth_body)
1156             out_java +=  ("}\n")
1157             out_java += ("\t\t}\n")
1158             out_java_enum += ("\t\t}\n")
1159             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"
1160             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1161             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1162             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1163         out_java += ("\t\tstatic native void init();\n")
1164         out_java += ("\t}\n")
1165         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1166         out_java_enum += (java_hu_subclasses)
1167         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1168         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1169
1170         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1171
1172         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")
1173         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)(ptr & ~1);\n")
1174         out_c += ("\tswitch(obj->tag) {\n")
1175         for var in variant_list:
1176             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1177             c_params = []
1178             for idx, (field_map, field_docs) in enumerate(var.fields):
1179                 if field_map.ret_conv is not None:
1180                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1181                     if var.tuple_variant:
1182                         out_c += "obj->" + camel_to_snake(var.var_name)
1183                     else:
1184                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1185                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1186                     c_params.append(field_map.ret_conv_name)
1187                 else:
1188                     if var.tuple_variant:
1189                         c_params.append("obj->" + camel_to_snake(var.var_name))
1190                     else:
1191                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1192             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1193             out_c += ("\t\t}\n")
1194         out_c += ("\t\tdefault: abort();\n")
1195         out_c += ("\t}\n}\n")
1196         return (out_java, out_java_enum, out_c)
1197
1198     def map_opaque_struct(self, struct_name, struct_doc_comment):
1199         out_opaque_struct_human = ""
1200         out_opaque_struct_human += self.hu_struct_file_prefix
1201         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1202         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1203         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1204         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1205         if struct_name.startswith("LDKLocked"):
1206             out_opaque_struct_human += (" implements AutoCloseable")
1207         out_opaque_struct_human += (" {\n")
1208         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1209         if struct_name.startswith("LDKLocked"):
1210             out_opaque_struct_human += ("\t@Override public void close() {\n")
1211         else:
1212             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1213             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1214             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1215         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1216         out_opaque_struct_human += ("\t}\n\n")
1217         return out_opaque_struct_human
1218
1219     def map_tuple(self, struct_name):
1220         return self.map_opaque_struct(struct_name, "A Tuple")
1221
1222     def map_result(self, struct_name, res_map, err_map):
1223         human_ty = struct_name.replace("LDKCResult", "Result")
1224         java_hu_struct = ""
1225         java_hu_struct += self.hu_struct_file_prefix
1226         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1227         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1228         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1229         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1230         java_hu_struct += "\t}\n\n"
1231         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1232         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1233         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1234         java_hu_struct += "\t\t} else {\n"
1235         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1236         java_hu_struct += "\t\t}\n"
1237         java_hu_struct += "\t}\n"
1238
1239         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1240
1241         if res_map.java_hu_ty != "void":
1242             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1243         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1244         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1245         if res_map.java_hu_ty == "void":
1246             pass
1247         elif res_map.to_hu_conv is not None:
1248             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1249             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1250             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1251         else:
1252             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1253         java_hu_struct += "\t\t}\n"
1254         java_hu_struct += "\t}\n\n"
1255
1256         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1257         if err_map.java_hu_ty != "void":
1258             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1259         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1260         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1261         if err_map.java_hu_ty == "void":
1262             pass
1263         elif err_map.to_hu_conv is not None:
1264             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1265             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1266             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1267         else:
1268             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1269         java_hu_struct += "\t\t}\n"
1270
1271         java_hu_struct += "\t}\n\n"
1272         return java_hu_struct
1273
1274     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):
1275         out_java = ""
1276         out_c = ""
1277         out_java_struct = None
1278
1279         out_java += ("\tpublic static native ")
1280         out_c += (self.c_fn_ty_pfx)
1281         out_c += (return_type_info.c_ty)
1282         out_java += (return_type_info.java_ty)
1283         if return_type_info.ret_conv is not None:
1284             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1285         out_java += (" " + method_name + "(")
1286         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1287         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1288
1289         for idx, arg_conv_info in enumerate(argument_types):
1290             if idx != 0:
1291                 out_java += (", ")
1292                 out_c += (", ")
1293             if arg_conv_info.c_ty != "void":
1294                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1295                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1296
1297         out_java_struct = ""
1298         extra_java_struct_out = ""
1299         if not args_known:
1300             out_java_struct += ("\t// Skipped " + method_name + "\n")
1301         else:
1302             if doc_comment is not None:
1303                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1304             if return_type_info.nullable:
1305                 out_java_struct += "\t@Nullable\n"
1306             if not takes_self:
1307                 if meth_n == "new":
1308                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1309                 elif meth_n == "default":
1310                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1311                 else:
1312                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1313             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1314                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1315             else:
1316                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1317                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1318                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1319                     extra_java_struct_out += "\t}\n"
1320                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1321                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1322                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1323                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1324                     extra_java_struct_out += "\t}\n"
1325                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1326             for idx, arg in enumerate(argument_types):
1327                 if idx != 0:
1328                     if not takes_self or idx > 1:
1329                         out_java_struct += ", "
1330                 elif takes_self:
1331                     continue
1332                 if arg.java_ty != "void":
1333                     if arg.arg_name in default_constructor_args:
1334                         assert not arg.nullable
1335                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1336                             if explode_idx != 0:
1337                                 out_java_struct += (", ")
1338                             out_java_struct += (
1339                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1340                     else:
1341                         if arg.nullable:
1342                             out_java_struct += "@Nullable "
1343                         ty_string = arg.java_hu_ty
1344                         if arg.java_fn_ty_arg[0] == "L" and arg.java_fn_ty_arg[len(arg.java_fn_ty_arg) - 1] == ";":
1345                             ty_string = arg.java_fn_ty_arg.strip("L;").replace("/", ".")
1346                         out_java_struct += ty_string + " " + arg.arg_name
1347         out_java += (");\n")
1348         out_c += (") {\n")
1349         if out_java_struct is not None:
1350             out_java_struct += (") {\n")
1351         for info in argument_types:
1352             if info.arg_conv is not None:
1353                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1354         if return_type_info.ret_conv is not None:
1355             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1356         elif return_type_info.c_ty != "void":
1357             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1358         else:
1359             out_c += ("\t")
1360         if c_call_string is None:
1361             out_c += (method_name + "(")
1362         else:
1363             out_c += (c_call_string)
1364         for idx, info in enumerate(argument_types):
1365             if info.arg_conv_name is not None:
1366                 if idx != 0:
1367                     out_c += (", ")
1368                 elif c_call_string is not None:
1369                     continue
1370                 out_c += (info.arg_conv_name)
1371         out_c += (")")
1372         if return_type_info.ret_conv is not None:
1373             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1374         else:
1375             out_c += (";")
1376         for info in argument_types:
1377             if info.arg_conv_cleanup is not None:
1378                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1379         if return_type_info.ret_conv is not None:
1380             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1381         elif return_type_info.c_ty != "void":
1382             out_c += ("\n\treturn ret_val;")
1383         out_c += ("\n}\n\n")
1384
1385         if args_known:
1386             out_java_struct += ("\t\t")
1387             if return_type_info.java_ty != "void":
1388                 out_java_struct += (return_type_info.java_ty + " ret = ")
1389             out_java_struct += ("bindings." + method_name + "(")
1390             for idx, info in enumerate(argument_types):
1391                 if idx != 0:
1392                     out_java_struct += (", ")
1393                 if idx == 0 and takes_self:
1394                     out_java_struct += ("this.ptr")
1395                 elif info.arg_name in default_constructor_args:
1396                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1397                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1398                         if explode_idx != 0:
1399                             out_java_struct += (", ")
1400                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1401                         if explode_arg.from_hu_conv is not None:
1402                             out_java_struct += (
1403                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1404                         else:
1405                             out_java_struct += (expl_arg_name)
1406                     out_java_struct += (")")
1407                 elif info.from_hu_conv is not None:
1408                     out_java_struct += (info.from_hu_conv[0])
1409                 else:
1410                     out_java_struct += (info.arg_name)
1411             out_java_struct += (");\n")
1412
1413             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1414             # the stack, calling its finalizer immediately even if member methods are *actively
1415             # executing* on the same object, as long as said object is on the stack. There is no
1416             # concrete specification for when the optimizer is allowed to do this, and when it is
1417             # not, so there is absolutely no way to be certain that this fix suffices.
1418             #
1419             # Instead, the "Java Language Specification" says only that an object is reachable
1420             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1421             # computation from any live thread". To any sensible reader this would mean actively
1422             # executing a member function on an object would make it not eligible for finalization.
1423             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1424             # very explicitly in fact, but those are just, like, words, man.
1425             #
1426             # In the seemingly non-normative text further down, a few examples of things the
1427             # optimizer can do are given, including "if the values in an object's fields are
1428             # stored in registers[, t]he may then access the registers instead of the object, and
1429             # never access the object again[, implying] that the object is garbage". This appears
1430             # to fully contradict both the above statement, the API documentation in java.lang.ref
1431             # regarding when a reference is "strongly reachable", and basic common sense. There is
1432             # no concrete set of limitations stated, however, seemingly implying the JIT could
1433             # decide your code would run faster by simply garbage collecting everything
1434             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1435             # entirely flying blind here. We add some fences and hope that its sufficient, but
1436             # with no specification to rely on, we cannot be certain of anything.
1437             #
1438             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1439             # object will be considered available for garbage collection once the JIT kicks in, so
1440             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1441             for idx, info in enumerate(argument_types):
1442                 if idx == 0 and takes_self:
1443                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1444                 elif info.arg_name in default_constructor_args:
1445                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1446                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1447                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1448                 elif info.c_ty != "void":
1449                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1450
1451             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1452                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1453
1454             if return_type_info.to_hu_conv is not None:
1455                 if not takes_self:
1456                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1457                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1458                 else:
1459                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1460
1461             for idx, info in enumerate(argument_types):
1462                 if idx == 0 and takes_self:
1463                     pass
1464                 elif info.arg_name in default_constructor_args:
1465                     for explode_arg in default_constructor_args[info.arg_name]:
1466                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1467                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1468                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1469                                                                                                expl_arg_name).replace(
1470                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1471                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1472                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1473                         out_java_struct += (
1474                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1475                     else:
1476                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1477
1478             if takes_self and not takes_self_as_ref:
1479                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1480             if return_type_info.to_hu_conv_name is not None:
1481                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1482             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1483                 out_java_struct += ("\t\treturn ret;\n")
1484             out_java_struct += ("\t}\n\n")
1485
1486         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1487
1488     def cleanup(self):
1489         pass