[Java] Always log the LDK versions on startup
[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         self.java_type_map = dict(
20             String = "String"
21         )
22         self.java_hu_type_map = dict(
23             String = "String"
24         )
25
26         self.to_hu_conv_templates = dict(
27             ptr = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }',
28             default = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }'
29         )
30
31         self.bindings_header = """package org.ldk.impl;
32 import org.ldk.enums.*;
33 import org.ldk.impl.version;
34 import java.io.File;
35 import java.io.InputStream;
36 import java.io.IOException;
37 import java.nio.file.Files;
38 import java.nio.file.Path;
39 import java.nio.file.StandardCopyOption;
40
41 public class bindings {
42         public static class VecOrSliceDef {
43                 public long dataptr;
44                 public long datalen;
45                 public long stride;
46                 public VecOrSliceDef(long dataptr, long datalen, long stride) {
47                         this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
48                 }
49         }
50         static {
51                 try {
52                         // Try to load natively first, this works on Android and in testing.
53                         System.loadLibrary(\"lightningjni\");
54                 } catch (UnsatisfiedLinkError system_load_err) {
55                         // Otherwise try to load from the library jar.
56                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
57                         tmpdir.mkdir(); // If it fails to create, assume it was there already
58                         tmpdir.deleteOnExit();
59                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
60                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
61                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
62                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
63                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
64                                 Runtime.getRuntime().load(libpath.toString());
65                         } catch (Exception e) {
66                                 System.err.println("Failed to load LDK native library.");
67                                 System.err.println("System LDK native library load failed with: " + system_load_err);
68                                 System.err.println("Resource-based LDK native library load failed with: " + e);
69                                 throw new IllegalArgumentException(e);
70                         }
71                 }
72                 init(java.lang.Enum.class, VecOrSliceDef.class);
73                 init_class_cache();
74                 if (!get_lib_version_string().equals(version.get_ldk_java_bindings_version()))
75                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
76                 // Fetching the LDK versions from C also checks that the header and binaries match
77                 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());
78         }
79         static native void init(java.lang.Class c, java.lang.Class slicedef);
80         static native void init_class_cache();
81         static native String get_lib_version_string();
82
83         public static native String get_ldk_c_bindings_version();
84         public static native String get_ldk_version();
85
86         public static native boolean deref_bool(long ptr);
87         public static native long deref_long(long ptr);
88         public static native void free_heap_ptr(long ptr);
89         public static native byte[] read_bytes(long ptr, long len);
90         public static native byte[] get_u8_slice_bytes(long slice_ptr);
91         public static native long bytes_to_u8_vec(byte[] bytes);
92         public static native long new_txpointer_copy_data(byte[] txdata);
93         public static native void txpointer_free(long ptr);
94         public static native byte[] txpointer_get_buffer(long ptr);
95         public static native long vec_slice_len(long vec);
96         public static native long new_empty_slice_vec();
97
98 """
99         self.bindings_version_file = """package org.ldk.impl;
100
101 public class version {
102         public static String get_ldk_java_bindings_version() {
103                 return "<git_version_ldk_garbagecollected>";
104         }
105 }"""
106
107         self.bindings_footer = "}\n"
108
109         self.util_fn_pfx = """package org.ldk.structs;
110 import org.ldk.impl.bindings;
111 import org.ldk.enums.*;
112 import org.ldk.util.*;
113 import java.util.Arrays;
114 import java.lang.ref.Reference;
115 import javax.annotation.Nullable;
116
117 public class UtilMethods {
118 """
119         self.util_fn_sfx = "}"
120         self.common_base = """package org.ldk.structs;
121 import java.util.LinkedList;
122 class CommonBase {
123         long ptr;
124         LinkedList<Object> ptrs_to = new LinkedList();
125         protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
126 }
127 """
128
129         self.txout_defn = """public class TxOut extends CommonBase {
130         /** The script_pubkey in this output */
131         public final byte[] script_pubkey;
132         /** The value, in satoshis, of this output */
133         public final long value;
134
135         TxOut(java.lang.Object _dummy, long ptr) {
136                 super(ptr);
137                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
138                 this.value = bindings.TxOut_get_value(ptr);
139         }
140         public TxOut(long value, byte[] script_pubkey) {
141                 super(bindings.TxOut_new(script_pubkey, value));
142                 this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
143                 this.value = bindings.TxOut_get_value(ptr);
144         }
145
146         @Override @SuppressWarnings(\"deprecation\")
147         protected void finalize() throws Throwable {
148                 super.finalize();
149                 if (ptr != 0) { bindings.TxOut_free(ptr); }
150         }
151 }"""
152
153         self.scalar_defn = """public class BigEndianScalar extends CommonBase {
154         /** The bytes of the scalar value, in big endian */
155         public final byte[] scalar_bytes;
156
157         BigEndianScalar(java.lang.Object _dummy, long ptr) {
158                 super(ptr);
159                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
160         }
161         public BigEndianScalar(byte[] scalar_bytes) {
162                 super(bindings.BigEndianScalar_new(scalar_bytes));
163                 this.scalar_bytes = bindings.BigEndianScalar_get_bytes(ptr);
164         }
165
166         @Override @SuppressWarnings(\"deprecation\")
167         protected void finalize() throws Throwable {
168                 super.finalize();
169                 if (ptr != 0) { bindings.BigEndianScalar_free(ptr); }
170         }
171 }"""
172
173
174         self.c_file_pfx = """#include <jni.h>
175 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
176 #define int64_t jlong
177 #include \"org_ldk_impl_bindings.h\"
178 #include <lightning.h>
179 #include <string.h>
180 #include <stdatomic.h>
181 #include <stdlib.h>
182
183 #define LIKELY(v) __builtin_expect(!!(v), 1)
184 #define UNLIKELY(v) __builtin_expect(!!(v), 0)
185
186 """
187
188         if self.target == Target.ANDROID:
189             self.c_file_pfx = self.c_file_pfx + """
190 #include <android/log.h>
191 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
192
193 #include <unistd.h>
194 #include <pthread.h>
195 static void* redirect_stderr(void* ignored) {
196         int pipes[2];
197         pipe(pipes);
198         dup2(pipes[1], STDERR_FILENO);
199         char buf[8192];
200         memset(buf, 0, 8192);
201         ssize_t len;
202         while ((len = read(pipes[0], buf, 8191)) > 0) {
203                 DEBUG_PRINT("%s\\n", buf);
204                 memset(buf, 0, 8192);
205         }
206         DEBUG_PRINT("End of stderr???\\n");
207         return 0;
208 }
209 void __attribute__((constructor)) spawn_stderr_redirection() {
210         pthread_t thread;
211         pthread_create(&thread, NULL, &redirect_stderr, NULL);
212 }
213 """
214         else:
215             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
216
217         if not DEBUG or sys.platform == "darwin":
218             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
219 #define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
220 #define CHECK_ACCESS(p)
221 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
222 """
223         if not DEBUG:
224             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
225 #define CHECK(a)
226 """
227         if DEBUG:
228             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
229 // Always run a, then assert it is true:
230 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
231 // Assert a is true or do nothing
232 #define CHECK(a) DO_ASSERT(a)
233
234 void __attribute__((constructor)) debug_log_version() {
235         if (check_get_ldk_version() == NULL)
236                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
237         if (check_get_ldk_bindings_version() == NULL)
238                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
239 }
240 """
241
242             if sys.platform != "darwin":
243                 self.c_file_pfx += """
244 // Running a leak check across all the allocations and frees of the JDK is a mess,
245 // so instead we implement our own naive leak checker here, relying on the -wrap
246 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
247 // and free'd in Rust or C across the generated bindings shared library.
248 #include <threads.h>
249 """
250
251                 if self.target == Target.ANDROID:
252                     self.c_file_pfx = self.c_file_pfx + """
253 #include <unwind.h>
254 #include <dlfcn.h>
255
256 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
257 // symbols, so we only use it on Android, where execinfo.h is unavailable.
258
259 struct BacktraceState {
260         void** current;
261         void** end;
262 };
263 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
264         struct BacktraceState* state = (struct BacktraceState*)arg;
265         uintptr_t pc = _Unwind_GetIP(context);
266         if (pc) {
267                 if (state->current == state->end) {
268                         return _URC_END_OF_STACK;
269                 } else {
270                         *state->current++ = (void*)(pc);
271                 }
272         }
273         return _URC_NO_REASON;
274 }
275
276 int backtrace(void** buffer, int max) {
277         struct BacktraceState state = { buffer, buffer + max };
278         _Unwind_Backtrace(unwind_callback, &state);
279         return state.current - buffer;
280 }
281
282 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
283         for (int idx = 0; idx < count; ++idx) {
284                 Dl_info info;
285                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
286                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
287                 } else {
288                         DEBUG_PRINT("%p: ???", buffer[idx]);
289                 }
290         }
291 }
292 """
293                 else:
294                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
295                 self.c_file_pfx = self.c_file_pfx + """
296 #include <unistd.h>
297 #include <pthread.h>
298 static pthread_mutex_t allocation_mtx;
299
300 void __attribute__((constructor)) init_mtx() {
301         DO_ASSERT(!pthread_mutex_init(&allocation_mtx, NULL));
302 }
303
304 #define BT_MAX 128
305 typedef struct allocation {
306         struct allocation* next;
307         void* ptr;
308         const char* struct_name;
309         void* bt[BT_MAX];
310         int bt_len;
311         unsigned long alloc_len;
312 } allocation;
313 static allocation* allocation_ll = NULL;
314
315 void* __real_malloc(size_t len);
316 void* __real_calloc(size_t nmemb, size_t len);
317 static void new_allocation(void* res, const char* struct_name, size_t len) {
318         allocation* new_alloc = __real_malloc(sizeof(allocation));
319         new_alloc->ptr = res;
320         new_alloc->struct_name = struct_name;
321         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
322         new_alloc->alloc_len = len;
323         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
324         new_alloc->next = allocation_ll;
325         allocation_ll = new_alloc;
326         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
327 }
328 static void* MALLOC(size_t len, const char* struct_name) {
329         void* res = __real_malloc(len);
330         new_allocation(res, struct_name, len);
331         return res;
332 }
333 void __real_free(void* ptr);
334 static void alloc_freed(void* ptr) {
335         allocation* p = NULL;
336         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
337         allocation* it = allocation_ll;
338         while (it->ptr != ptr) {
339                 p = it; it = it->next;
340                 if (it == NULL) {
341                         DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
342                         void* bt[BT_MAX];
343                         int bt_len = backtrace(bt, BT_MAX);
344                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
345                         DEBUG_PRINT("\\n\\n");
346                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
347                         return; // addrsan should catch malloc-unknown and print more info than we have
348                 }
349         }
350         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
351         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
352         DO_ASSERT(it->ptr == ptr);
353         __real_free(it);
354 }
355 static void FREE(void* ptr) {
356         if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
357         alloc_freed(ptr);
358         __real_free(ptr);
359 }
360
361 void* __wrap_malloc(size_t len) {
362         void* res = __real_malloc(len);
363         new_allocation(res, "malloc call", len);
364         return res;
365 }
366 void* __wrap_calloc(size_t nmemb, size_t len) {
367         void* res = __real_calloc(nmemb, len);
368         new_allocation(res, "calloc call", len);
369         return res;
370 }
371 void __wrap_free(void* ptr) {
372         if (ptr == NULL) return;
373         alloc_freed(ptr);
374         __real_free(ptr);
375 }
376
377 static void CHECK_ACCESS(const void* ptr) {
378         DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
379         allocation* it = allocation_ll;
380         while (it->ptr != ptr) {
381                 it = it->next;
382                 if (it == NULL) {
383                         DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
384                         void* bt[BT_MAX];
385                         int bt_len = backtrace(bt, BT_MAX);
386                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
387                         DEBUG_PRINT("\\n\\n");
388                         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
389                         return; // addrsan should catch and print more info than we have
390                 }
391         }
392         DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
393 }
394 #define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
395         if (v.is_owned && v.inner != NULL) { \\
396                 const void *p = __unmangle_inner_ptr(v.inner); \\
397                 if (p != NULL) { \\
398                         CHECK_ACCESS(p); \\
399                 } \\
400         }
401
402 void* __real_realloc(void* ptr, size_t newlen);
403 void* __wrap_realloc(void* ptr, size_t len) {
404         if (ptr != NULL) alloc_freed(ptr);
405         void* res = __real_realloc(ptr, len);
406         new_allocation(res, "realloc call", len);
407         return res;
408 }
409 void __wrap_reallocarray(void* ptr, size_t new_sz) {
410         // Rust doesn't seem to use reallocarray currently
411         DO_ASSERT(false);
412 }
413
414 void __attribute__((destructor)) check_leaks() {
415         unsigned long alloc_count = 0;
416         unsigned long alloc_size = 0;
417         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
418         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
419         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
420         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
421                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
422                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
423                 DEBUG_PRINT("\\n\\n");
424                 alloc_count++;
425                 alloc_size += a->alloc_len;
426         }
427         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
428         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
429         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
430 }
431 """
432         self.c_file_pfx = self.c_file_pfx + """
433 static jmethodID ordinal_meth = NULL;
434 static jmethodID slicedef_meth = NULL;
435 static jclass slicedef_cls = NULL;
436 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
437         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
438         CHECK(ordinal_meth != NULL);
439         slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
440         CHECK(slicedef_meth != NULL);
441         slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
442         CHECK(slicedef_cls != NULL);
443 }
444
445 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
446         return *((bool*)ptr);
447 }
448 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
449         return *((long*)ptr);
450 }
451 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
452         FREE((void*)ptr);
453 }
454 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * env, jclass _b, jlong ptr, jlong len) {
455         jbyteArray ret_arr = (*env)->NewByteArray(env, len);
456         (*env)->SetByteArrayRegion(env, ret_arr, 0, len, (unsigned char*)ptr);
457         return ret_arr;
458 }
459 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * env, jclass _b, jlong slice_ptr) {
460         LDKu8slice *slice = (LDKu8slice*)slice_ptr;
461         jbyteArray ret_arr = (*env)->NewByteArray(env, slice->datalen);
462         (*env)->SetByteArrayRegion(env, ret_arr, 0, slice->datalen, slice->data);
463         return ret_arr;
464 }
465 JNIEXPORT int64_t impl_bindings_bytes_1to_1u8_1vec (JNIEnv * env, jclass _b, jbyteArray bytes) {
466         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
467         vec->datalen = (*env)->GetArrayLength(env, bytes);
468         vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
469         (*env)->GetByteArrayRegion (env, bytes, 0, vec->datalen, vec->data);
470         return (uint64_t)vec;
471 }
472 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_txpointer_1get_1buffer (JNIEnv * env, jclass _b, jlong ptr) {
473         LDKTransaction *txdata = (LDKTransaction*)ptr;
474         LDKu8slice slice;
475         slice.data = txdata->data;
476         slice.datalen = txdata->datalen;
477         return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (uint64_t)&slice);
478 }
479 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
480         LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
481         txdata->datalen = (*env)->GetArrayLength(env, bytes);
482         txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
483         txdata->data_is_owned = false;
484         (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
485         return (uint64_t)txdata;
486 }
487 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
488         LDKTransaction *tx = (LDKTransaction*)ptr;
489         tx->data_is_owned = true;
490         Transaction_free(*tx);
491         FREE((void*)ptr);
492 }
493 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
494         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
495         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
496         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
497         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");
498         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_C2Tuple_usizeTransactionZZ, datalen), "Vec<*> needs to be mapped identically");
499         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
500         return (uint64_t)vec->datalen;
501 }
502 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * env, jclass _b) {
503         // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
504         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
505         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
506         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
507         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
508         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
509         vec->data = NULL;
510         vec->datalen = 0;
511         return (uint64_t)vec;
512 }
513
514 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
515 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
516 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
517 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
518
519 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
520 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
521 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
522
523 typedef jlongArray int64_tArray;
524 typedef jbyteArray int8_tArray;
525
526 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
527         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
528         char* conv_buf = MALLOC(len + 1, "str conv buf");
529         memcpy(conv_buf, chars, len);
530         conv_buf[len] = 0;
531         jstring ret = (*env)->NewStringUTF(env, conv_buf);
532         FREE(conv_buf);
533         return ret;
534 }
535 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
536         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
537         char* newchars = MALLOC(str_len + 1, "String chars");
538         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
539         memcpy(newchars, jchars, str_len);
540         newchars[str_len] = 0;
541         (*env)->ReleaseStringUTFChars(env, str, jchars);
542         LDKStr res = {
543                 .chars = newchars,
544                 .len = str_len,
545                 .chars_is_owned = true
546         };
547         return res;
548 }
549
550 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
551         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
552 }
553 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
554         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
555 }
556 #include "version.c"
557 """
558         self.c_version_file = """JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
559         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
560 }"""
561
562         self.hu_struct_file_prefix = """package org.ldk.structs;
563
564 import org.ldk.impl.bindings;
565 import org.ldk.enums.*;
566 import org.ldk.util.*;
567 import java.util.Arrays;
568 import java.lang.ref.Reference;
569 import javax.annotation.Nullable;
570
571 """
572         self.c_fn_ty_pfx = "JNIEXPORT "
573         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
574         self.file_ext = ".java"
575         self.ptr_c_ty = "int64_t"
576         self.ptr_native_ty = "long"
577         self.usize_c_ty = "int64_t"
578         self.usize_native_ty = "long"
579         self.native_zero_ptr = "0"
580         self.result_c_ty = "jclass"
581         self.ptr_arr = "jobjectArray"
582         self.is_arr_some_check = ("", " != NULL")
583         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
584
585     def construct_jenv(self):
586         res =  "JNIEnv *env;\n"
587         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
588         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
589         if self.target == Target.ANDROID:
590             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
591         else:
592             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
593         res += "} else {\n"
594         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
595         res += "}\n"
596         return res
597     def deconstruct_jenv(self):
598         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
599         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
600         res += "}\n"
601         return res
602
603     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
604         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
605             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
606         return None
607     def create_native_arr_call(self, arr_len, ty_info):
608         if ty_info.c_ty == "int8_tArray":
609             return "(*env)->NewByteArray(env, " + arr_len + ")"
610         elif ty_info.subty.c_ty.endswith("Array"):
611             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
612             self.c_array_class_caches.add(clz_var)
613             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
614         else:
615             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
616     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
617         if ty_info.c_ty == "int8_tArray":
618             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
619         else:
620             assert False
621     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
622         if ty_info.c_ty == "int8_tArray":
623             if copy:
624                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
625             else:
626                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
627         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
628             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
629         else:
630             return None
631     def get_native_arr_elem(self, arr_name, idxc, ty_info):
632         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
633             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
634         else:
635             assert False # Only called if above is None
636     def get_native_arr_ptr_call(self, ty_info):
637         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
638             return None
639         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
640     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
641         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
642             return None
643         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
644     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
645         if ty_info.c_ty == "int8_tArray":
646             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
647         else:
648             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
649
650     def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
651         if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
652             return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
653         elif elem_ty.java_ty == "long":
654             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
655         elif elem_ty.java_hu_ty == "UInt5":
656             return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
657         elif elem_ty.java_hu_ty == "WitnessVersion":
658             return arr_name + " != null ? InternalUtils.convWitnessVersionArray(" + arr_name + ") : null"
659         else:
660             return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
661
662     def str_ref_to_native_call(self, var_name, str_len):
663         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
664     def str_ref_to_c_call(self, var_name):
665         return "java_to_owned_str(env, " + var_name + ")"
666     def str_to_hu_conv(self, var_name):
667         return None
668     def str_from_hu_conv(self, var_name):
669         return None
670
671     def c_fn_name_define_pfx(self, fn_name, has_args):
672         if has_args:
673             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
674         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
675
676     def init_str(self):
677         res = ""
678         for ty in sorted(self.c_array_class_caches):
679             res = res + "static jclass " + ty + "_clz = NULL;\n"
680         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
681         for ty in sorted(self.c_array_class_caches):
682             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
683             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
684             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
685         res = res + "}\n"
686         return res
687
688     def var_decl_statement(self, ty_string, var_name, statement):
689         return ty_string + " " + var_name + " = " + statement
690
691     def get_java_arr_len(self, arr_name):
692         return arr_name + ".length"
693     def get_java_arr_elem(self, elem_ty, arr_name, idx):
694         return arr_name + "[" + idx + "]"
695     def constr_hu_array(self, ty_info, arr_len):
696         base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
697         conv = "new " + base_ty + "[" + arr_len + "]"
698         if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
699             # Do a bit of a dance to move any excess [] to the end
700             conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
701         return conv
702     def cleanup_converted_native_array(self, ty_info, arr_name):
703         return None
704
705     def primitive_arr_from_hu(self, mapped_ty, fixed_len, arr_name):
706         if fixed_len is not None:
707             return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
708         return None
709     def primitive_arr_to_hu(self, primitive_ty, fixed_len, arr_name, conv_name):
710         return None
711
712     def java_arr_ty_str(self, elem_ty_str):
713         return elem_ty_str + "[]"
714
715     def for_n_in_range(self, n, minimum, maximum):
716         return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
717     def for_n_in_arr(self, n, arr_name, arr_elem_ty):
718         return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
719
720     def get_ptr(self, var):
721         return var + ".ptr"
722     def set_null_skip_free(self, var):
723         return var + ".ptr" + " = 0;"
724
725     def add_ref(self, holder, referent):
726         return "if (" + holder + " != null) { " + holder + ".ptrs_to.add(" + referent + "); }"
727
728     def fully_qualified_hu_ty_path(self, ty):
729         if ty.java_fn_ty_arg.startswith("L") and ty.java_fn_ty_arg.endswith(";"):
730             return ty.java_fn_ty_arg.strip("L;").replace("/", ".")
731         if ty.java_hu_ty == "UnqualifiedError" or ty.java_hu_ty == "UInt5" or ty.java_hu_ty == "WitnessVersion":
732             return "org.ldk.util." + ty.java_hu_ty
733         if not ty.is_native_primitive and ty.rust_obj is not None and not "[]" in ty.java_hu_ty:
734             return "org.ldk.structs." + ty.java_hu_ty
735         return ty.java_hu_ty
736
737     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
738         out_java_enum = "package org.ldk.enums;\n\n"
739         out_java = ""
740         out_c = ""
741         out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
742         out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
743         out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
744         out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
745         out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
746         out_c += "\t}\n"
747         out_c += "\tswitch (ord) {\n"
748
749         if enum_doc_comment is not None:
750             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
751         out_java_enum += "public enum " + struct_name + " {\n"
752         ord_v = 0
753         for var, var_docs in variants:
754             if var_docs is not None:
755                 out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
756             out_java_enum += "\t" + var + ",\n"
757             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
758             ord_v = ord_v + 1
759         out_java_enum = out_java_enum + "\t; static native void init();\n"
760         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
761         out_java_enum = out_java_enum + "}"
762         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
763         out_c += "\t}\n"
764         out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
765         out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
766         out_c += "}\n"
767
768         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
769         for var, _ in variants:
770             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
771         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"
772         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
773         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
774         for var, _ in variants:
775             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
776             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
777         out_c = out_c + "}\n"
778         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
779         out_c = out_c + "\tswitch (val) {\n"
780         ord_v = 0
781         for var, _ in variants:
782             out_c = out_c + "\t\tcase " + var + ":\n"
783             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
784             ord_v = ord_v + 1
785         out_c = out_c + "\t\tdefault: abort();\n"
786         out_c = out_c + "\t}\n"
787         out_c = out_c + "}\n\n"
788
789         return (out_c, out_java_enum, out_java)
790
791     def c_unitary_enum_to_native_call(self, ty_info):
792         return (ty_info.rust_obj + "_to_java(env, ", ")")
793     def native_unitary_enum_to_c_call(self, ty_info):
794         return (ty_info.rust_obj + "_from_java(env, ", ")")
795
796     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
797         out_c = ""
798         for var in variants:
799             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
800             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
801         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"
802         for var_name in variants:
803             out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
804             out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
805             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
806             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"
807             out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
808         out_c = out_c + "}\n"
809         return out_c
810
811     def c_complex_enum_pass_ty(self, struct_name):
812         return "jobject"
813
814     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
815         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
816         for param in c_params:
817             ret = ret + ", " + param
818         return ret + ")"
819
820     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
821         out_java_trait = ""
822         out_java = ""
823
824         # First generate most of the Java code, note that we need information about java method argument strings for C
825         out_java_trait = out_java_trait + self.hu_struct_file_prefix
826         if trait_doc_comment is not None:
827             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
828         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
829         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
830         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
831         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
832         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
833         for var in flattened_field_vars:
834             if isinstance(var, ConvInfo):
835                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
836             else:
837                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
838         out_java_trait = out_java_trait + ") {\n"
839         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
840         for var in flattened_field_vars:
841             if isinstance(var, ConvInfo):
842                 if var.from_hu_conv is not None:
843                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
844                 else:
845                     out_java_trait = out_java_trait + ", " + var.arg_name
846             else:
847                 out_java_trait = out_java_trait + ", " + var[1]
848         out_java_trait = out_java_trait + "));\n"
849         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
850         for var in flattened_field_vars:
851             if isinstance(var, ConvInfo):
852                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
853                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
854             else:
855                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
856         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
857         out_java_trait = out_java_trait + "\t}\n"
858         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
859         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
860         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
861         out_java_trait = out_java_trait + "\t}\n\n"
862
863         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
864         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
865         for var in flattened_field_vars:
866             if isinstance(var, ConvInfo):
867                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
868             else:
869                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
870                 # Java-implemented version, so we require users pass a Java implementation here :/
871                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
872         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
873         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
874         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
875         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
876         java_meths = []
877         for fn_line in field_fns:
878             java_meth_descr = "("
879             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
880                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
881                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
882                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
883                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
884
885                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
886                     if idx >= 1:
887                         out_java = out_java + ", "
888                         java_trait_constr = java_trait_constr + ", "
889                         out_java_trait = out_java_trait + ", "
890                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
891                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
892                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
893                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
894                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
895                 java_meths.append((fn_line.fn_name, java_meth_descr))
896
897                 out_java = out_java + ");\n"
898                 out_java_trait = out_java_trait + ");\n"
899                 java_trait_constr = java_trait_constr + ") {\n"
900
901                 for arg_info in fn_line.args_ty:
902                     if arg_info.to_hu_conv is not None:
903                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
904
905                 if fn_line.ret_ty_info.java_ty != "void":
906                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
907                 else:
908                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
909
910                 for idx, arg_info in enumerate(fn_line.args_ty):
911                     if idx != 0:
912                         java_trait_constr = java_trait_constr + ", "
913                     if arg_info.to_hu_conv_name is not None:
914                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
915                     else:
916                         java_trait_constr = java_trait_constr + arg_info.arg_name
917
918                 java_trait_constr += ");\n"
919                 java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
920                 if fn_line.ret_ty_info.java_ty != "void":
921                     if fn_line.ret_ty_info.from_hu_conv is not None:
922                         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"
923                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
924                             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"
925                         #if fn_line.ret_ty_info.rust_obj in result_types:
926                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
927                     else:
928                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
929                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
930         java_trait_constr = java_trait_constr + "\t\t}"
931         for var in field_vars:
932             if isinstance(var, ConvInfo):
933                 java_trait_constr = java_trait_constr + ", " + var.arg_name
934             else:
935                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
936                 for suparg in var[2]:
937                     if isinstance(suparg, ConvInfo):
938                         java_trait_constr += ", " + suparg.arg_name
939                     else:
940                         java_trait_constr += ", " + suparg[1]
941                 java_trait_constr += ").bindings_instance"
942                 for suparg in var[2]:
943                     if isinstance(suparg, ConvInfo):
944                         java_trait_constr += ", " + suparg.arg_name
945                     else:
946                         java_trait_constr += ", " + suparg[1]
947         out_java_trait = out_java_trait + "\t}\n"
948         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
949
950         out_java = out_java + "\t}\n"
951
952         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
953         for var in flattened_field_vars:
954             if isinstance(var, ConvInfo):
955                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
956             else:
957                 out_java = out_java + ", " + var[0] + " " + var[1]
958         out_java = out_java + ");\n"
959
960         # Now that we've written out our java code (and created java_meths), generate C
961         out_c = "typedef struct " + struct_name + "_JCalls {\n"
962         out_c = out_c + "\tatomic_size_t refcnt;\n"
963         out_c = out_c + "\tJavaVM *vm;\n"
964         out_c = out_c + "\tjweak o;\n"
965         for var in flattened_field_vars:
966             if isinstance(var, ConvInfo):
967                 # We're a regular ol' field
968                 pass
969             else:
970                 # We're a supertrait
971                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
972         for fn in field_fns:
973             if fn.fn_name != "free" and fn.fn_name != "cloned":
974                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
975         out_c = out_c + "} " + struct_name + "_JCalls;\n"
976
977         for fn_line in field_fns:
978             if fn_line.fn_name == "free":
979                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
980                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
981                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
982                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
983                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
984                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
985                 out_c = out_c + "\t\tFREE(j_calls);\n"
986                 out_c = out_c + "\t}\n}\n"
987
988         for idx, fn_line in enumerate(field_fns):
989             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
990                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
991                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
992                 if fn_line.self_is_const:
993                     out_c = out_c + "const void* this_arg"
994                 else:
995                     out_c = out_c + "void* this_arg"
996
997                 for idx, arg in enumerate(fn_line.args_ty):
998                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
999
1000                 out_c = out_c + ") {\n"
1001                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
1002                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
1003
1004                 for arg_info in fn_line.args_ty:
1005                     if arg_info.ret_conv is not None:
1006                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
1007                         out_c = out_c + arg_info.arg_name
1008                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
1009
1010                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
1011                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
1012                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1013                 elif fn_line.ret_ty_info.c_ty == "void":
1014                     out_c += "\t(*env)->CallVoidMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1015                 elif fn_line.ret_ty_info.java_hu_ty == "String" or "org/ldk/enums" in fn_line.ret_ty_info.java_fn_ty_arg:
1016                     # Manually write out String methods as they're just an Object
1017                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1018                 elif not fn_line.ret_ty_info.passed_as_ptr:
1019                     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"
1020                 else:
1021                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
1022
1023                 for idx, arg_info in enumerate(fn_line.args_ty):
1024                     if arg_info.ret_conv is not None:
1025                         out_c = out_c + ", " + arg_info.ret_conv_name
1026                     else:
1027                         out_c = out_c + ", " + arg_info.arg_name
1028                 out_c = out_c + ");\n"
1029
1030                 out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
1031                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
1032                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
1033                 out_c += "\t}\n"
1034
1035                 if fn_line.ret_ty_info.arg_conv is not None:
1036                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
1037                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1038                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
1039                 else:
1040                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
1041                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
1042                         out_c += "\treturn ret;\n"
1043
1044                 out_c = out_c + "}\n"
1045
1046         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
1047         can_clone_with_ptr = True
1048         for var in field_vars:
1049             if isinstance(var, ConvInfo):
1050                 can_clone_with_ptr = False
1051         if can_clone_with_ptr:
1052             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
1053             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
1054             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
1055             for var in field_vars:
1056                 if not isinstance(var, ConvInfo):
1057                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
1058             out_c = out_c + "}\n"
1059
1060         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
1061         for var in flattened_field_vars:
1062             if isinstance(var, ConvInfo):
1063                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1064             else:
1065                 out_c = out_c + ", jobject " + var[1]
1066         out_c = out_c + ") {\n"
1067
1068         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
1069         out_c = out_c + "\tCHECK(c != NULL);\n"
1070         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
1071         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
1072         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
1073         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
1074
1075         for (fn_name, java_meth_descr) in java_meths:
1076             if fn_name != "free" and fn_name != "cloned":
1077                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
1078                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
1079
1080         for var in flattened_field_vars:
1081             if isinstance(var, ConvInfo) and var.arg_conv is not None:
1082                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
1083         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
1084         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
1085         for fn_line in field_fns:
1086             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
1087                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
1088             elif fn_line.fn_name == "free":
1089                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
1090             else:
1091                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
1092         for var in field_vars:
1093             if isinstance(var, ConvInfo):
1094                 if var.arg_conv_name is not None:
1095                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
1096                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
1097                 else:
1098                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
1099                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
1100             else:
1101                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
1102                 for suparg in var[2]:
1103                     if isinstance(suparg, ConvInfo):
1104                         out_c = out_c + ", " + suparg.arg_name
1105                     else:
1106                         out_c = out_c + ", " + suparg[1]
1107                 out_c += "),\n"
1108         out_c = out_c + "\t};\n"
1109         for var in flattened_field_vars:
1110             if not isinstance(var, ConvInfo):
1111                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
1112         out_c = out_c + "\treturn ret;\n"
1113         out_c = out_c + "}\n"
1114
1115         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
1116         for var in flattened_field_vars:
1117             if isinstance(var, ConvInfo):
1118                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
1119             else:
1120                 out_c = out_c + ", jobject " + var[1]
1121         out_c = out_c + ") {\n"
1122         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
1123         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
1124         for var in flattened_field_vars:
1125             if isinstance(var, ConvInfo):
1126                 out_c = out_c + ", " + var.arg_name
1127             else:
1128                 out_c = out_c + ", " + var[1]
1129         out_c = out_c + ");\n"
1130         out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
1131         out_c = out_c + "}\n"
1132
1133         for var in flattened_field_vars:
1134             if not isinstance(var, ConvInfo):
1135                 out_java_trait += "\n\t/**\n"
1136                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
1137                 out_java_trait += "\t */\n"
1138                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
1139                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
1140                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
1141                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
1142                 out_java_trait += "\t\treturn res;\n"
1143                 out_java_trait += "\t}\n"
1144                 out_java_trait += "\n"
1145
1146                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
1147
1148                 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"
1149                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)untag_ptr(arg);\n"
1150                 out_c += "\treturn tag_ptr(&inp->" + var[1] + ", false);\n"
1151                 out_c += "}\n"
1152
1153         return (out_java, out_java_trait, out_c)
1154
1155     def trait_struct_inc_refcnt(self, ty_info):
1156         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
1157         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
1158         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
1159         return base_conv
1160
1161     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1162         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1163         out_java_enum = ""
1164         out_java = ""
1165         out_c = ""
1166
1167         out_java_enum += (self.hu_struct_file_prefix)
1168         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1169         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1170         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1171         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1172         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1173         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1174         out_java_enum += ("\t\tsuper.finalize();\n")
1175         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1176         out_java_enum += ("\t}\n")
1177         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1178         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1179         java_hu_subclasses = ""
1180
1181         init_meth_jty_strs = {}
1182
1183         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1184         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1185         for var in variant_list:
1186             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1187             if var.var_docs is not None:
1188                 java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
1189             java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1190             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1191             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1192             init_meth_jty_str = ""
1193             init_meth_params = ""
1194             init_meth_body = ""
1195             hu_conv_body = ""
1196             for idx, (field_ty, field_docs) in enumerate(var.fields):
1197                 if idx > 0:
1198                     init_meth_params = init_meth_params + ", "
1199
1200                 java_ty = field_ty.java_ty
1201                 if field_ty.java_fn_ty_arg.startswith("L") and field_ty.java_fn_ty_arg.endswith(";"):
1202                     # If this is a simple enum, we have to reference it in the low-level bindings differently:
1203                     java_ty = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1204                 out_java += "\t\t\tpublic " + java_ty + " " + field_ty.arg_name + ";\n"
1205                 if field_docs is not None:
1206                     java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1207                 java_hu_subclasses += "\t\t"
1208                 if field_ty.nullable:
1209                     java_hu_subclasses += "@Nullable "
1210                 java_hu_subclasses += "public final " + self.fully_qualified_hu_ty_path(field_ty) + " " + field_ty.arg_name + ";\n"
1211                 init_meth_params = init_meth_params + java_ty + " " + field_ty.arg_name
1212
1213                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1214                 if field_ty.to_hu_conv is not None:
1215                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1216                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1217                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1218                 else:
1219                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1220                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1221             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1222             out_java +=  (init_meth_body)
1223             out_java +=  ("}\n")
1224             out_java += ("\t\t}\n")
1225             out_java_enum += ("\t\t}\n")
1226             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"
1227             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1228             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1229             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1230         out_java += ("\t\tstatic native void init();\n")
1231         out_java += ("\t}\n")
1232         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1233         out_java_enum += (java_hu_subclasses)
1234         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1235         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1236
1237         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1238
1239         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")
1240         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n")
1241         out_c += ("\tswitch(obj->tag) {\n")
1242         for var in variant_list:
1243             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1244             c_params = []
1245             for idx, (field_map, field_docs) in enumerate(var.fields):
1246                 if field_map.ret_conv is not None:
1247                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1248                     if var.tuple_variant:
1249                         out_c += "obj->" + camel_to_snake(var.var_name)
1250                     else:
1251                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1252                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1253                     c_params.append(field_map.ret_conv_name)
1254                 else:
1255                     if var.tuple_variant:
1256                         c_params.append("obj->" + camel_to_snake(var.var_name))
1257                     else:
1258                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1259             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1260             out_c += ("\t\t}\n")
1261         out_c += ("\t\tdefault: abort();\n")
1262         out_c += ("\t}\n}\n")
1263         return (out_java, out_java_enum, out_c)
1264
1265     def map_opaque_struct(self, struct_name, struct_doc_comment):
1266         out_opaque_struct_human = ""
1267         out_opaque_struct_human += self.hu_struct_file_prefix
1268         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1269         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1270         hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
1271         out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
1272         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1273             out_opaque_struct_human += (" implements AutoCloseable")
1274         out_opaque_struct_human += (" {\n")
1275         out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
1276         if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
1277             out_opaque_struct_human += ("\t@Override public void close() {\n")
1278         else:
1279             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1280             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1281             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1282         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1283         out_opaque_struct_human += ("\t}\n\n")
1284         return out_opaque_struct_human
1285
1286     def map_tuple(self, struct_name):
1287         return self.map_opaque_struct(struct_name, "A Tuple")
1288
1289     def map_result(self, struct_name, res_map, err_map):
1290         human_ty = struct_name.replace("LDKCResult", "Result")
1291         java_hu_struct = ""
1292         java_hu_struct += self.hu_struct_file_prefix
1293         java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
1294         java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
1295         java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
1296         java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
1297         java_hu_struct += "\t}\n\n"
1298         java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
1299         java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
1300         java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
1301         java_hu_struct += "\t\t} else {\n"
1302         java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
1303         java_hu_struct += "\t\t}\n"
1304         java_hu_struct += "\t}\n"
1305
1306         java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
1307
1308         if res_map.java_hu_ty != "void":
1309             java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
1310         java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
1311         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1312         if res_map.java_hu_ty == "void":
1313             pass
1314         elif res_map.to_hu_conv is not None:
1315             java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1316             java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
1317             java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
1318         else:
1319             java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
1320         java_hu_struct += "\t\t}\n"
1321         java_hu_struct += "\t}\n\n"
1322
1323         java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
1324         if err_map.java_hu_ty != "void":
1325             java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
1326         java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
1327         java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
1328         if err_map.java_hu_ty == "void":
1329             pass
1330         elif err_map.to_hu_conv is not None:
1331             java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1332             java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
1333             java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
1334         else:
1335             java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
1336         java_hu_struct += "\t\t}\n"
1337
1338         java_hu_struct += "\t}\n\n"
1339         return java_hu_struct
1340
1341     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):
1342         out_java = ""
1343         out_c = ""
1344         out_java_struct = None
1345
1346         out_java += ("\tpublic static native ")
1347         out_c += (self.c_fn_ty_pfx)
1348         out_c += (return_type_info.c_ty)
1349         out_java += (return_type_info.java_ty)
1350         if return_type_info.ret_conv is not None:
1351             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1352         out_java += (" " + method_name + "(")
1353         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1354         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1355
1356         for idx, arg_conv_info in enumerate(argument_types):
1357             if idx != 0:
1358                 out_java += (", ")
1359                 out_c += (", ")
1360             if arg_conv_info.c_ty != "void":
1361                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1362                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1363
1364         out_java_struct = ""
1365         extra_java_struct_out = ""
1366         if not args_known:
1367             out_java_struct += ("\t// Skipped " + method_name + "\n")
1368         else:
1369             if doc_comment is not None:
1370                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1371             if return_type_info.nullable:
1372                 out_java_struct += "\t@Nullable\n"
1373             if not takes_self:
1374                 if meth_n == "new":
1375                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1376                 elif meth_n == "default":
1377                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1378                 else:
1379                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1380             elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
1381                 out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
1382             else:
1383                 if meth_n == "hash" and return_type_info.java_hu_ty == "long":
1384                     extra_java_struct_out = "\t@Override public int hashCode() {\n"
1385                     extra_java_struct_out += "\t\treturn (int)this.hash();\n"
1386                     extra_java_struct_out += "\t}\n"
1387                 elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
1388                     extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
1389                     extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
1390                     extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
1391                     extra_java_struct_out += "\t}\n"
1392                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1393             for idx, arg in enumerate(argument_types):
1394                 if idx != 0:
1395                     if not takes_self or idx > 1:
1396                         out_java_struct += ", "
1397                 elif takes_self:
1398                     continue
1399                 if arg.java_ty != "void":
1400                     if arg.arg_name in default_constructor_args:
1401                         assert not arg.nullable
1402                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1403                             if explode_idx != 0:
1404                                 out_java_struct += (", ")
1405                             out_java_struct += (
1406                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1407                     else:
1408                         if arg.nullable:
1409                             out_java_struct += "@Nullable "
1410                         ty_string = arg.java_hu_ty
1411                         if arg.java_fn_ty_arg[0] == "L" and arg.java_fn_ty_arg[len(arg.java_fn_ty_arg) - 1] == ";":
1412                             ty_string = arg.java_fn_ty_arg.strip("L;").replace("/", ".")
1413                         out_java_struct += ty_string + " " + arg.arg_name
1414         out_java += (");\n")
1415         out_c += (") {\n")
1416         if out_java_struct is not None:
1417             out_java_struct += (") {\n")
1418         for info in argument_types:
1419             if info.arg_conv is not None:
1420                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1421         if return_type_info.ret_conv is not None:
1422             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1423         elif return_type_info.c_ty != "void":
1424             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1425         else:
1426             out_c += ("\t")
1427         if c_call_string is None:
1428             out_c += (method_name + "(")
1429         else:
1430             out_c += (c_call_string)
1431         for idx, info in enumerate(argument_types):
1432             if info.arg_conv_name is not None:
1433                 if idx != 0:
1434                     out_c += (", ")
1435                 elif c_call_string is not None:
1436                     continue
1437                 out_c += (info.arg_conv_name)
1438         out_c += (")")
1439         if return_type_info.ret_conv is not None:
1440             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1441         else:
1442             out_c += (";")
1443         for info in argument_types:
1444             if info.arg_conv_cleanup is not None:
1445                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1446         if return_type_info.ret_conv is not None:
1447             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1448         elif return_type_info.c_ty != "void":
1449             out_c += ("\n\treturn ret_val;")
1450         out_c += ("\n}\n\n")
1451
1452         if args_known:
1453             out_java_struct += ("\t\t")
1454             if return_type_info.java_ty != "void":
1455                 out_java_struct += (return_type_info.java_ty + " ret = ")
1456             out_java_struct += ("bindings." + method_name + "(")
1457             for idx, info in enumerate(argument_types):
1458                 if idx != 0:
1459                     out_java_struct += (", ")
1460                 if idx == 0 and takes_self:
1461                     out_java_struct += ("this.ptr")
1462                 elif info.arg_name in default_constructor_args:
1463                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1464                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1465                         if explode_idx != 0:
1466                             out_java_struct += (", ")
1467                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1468                         if explode_arg.from_hu_conv is not None:
1469                             out_java_struct += (
1470                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1471                         else:
1472                             out_java_struct += (expl_arg_name)
1473                     out_java_struct += (")")
1474                 elif info.from_hu_conv is not None:
1475                     out_java_struct += (info.from_hu_conv[0])
1476                 else:
1477                     out_java_struct += (info.arg_name)
1478             out_java_struct += (");\n")
1479
1480             # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
1481             # the stack, calling its finalizer immediately even if member methods are *actively
1482             # executing* on the same object, as long as said object is on the stack. There is no
1483             # concrete specification for when the optimizer is allowed to do this, and when it is
1484             # not, so there is absolutely no way to be certain that this fix suffices.
1485             #
1486             # Instead, the "Java Language Specification" says only that an object is reachable
1487             # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
1488             # computation from any live thread". To any sensible reader this would mean actively
1489             # executing a member function on an object would make it not eligible for finalization.
1490             # But, no, dear reader, this statement does not say that. Well, okay, it says that,
1491             # very explicitly in fact, but those are just, like, words, man.
1492             #
1493             # In the seemingly non-normative text further down, a few examples of things the
1494             # optimizer can do are given, including "if the values in an object's fields are
1495             # stored in registers[, t]he may then access the registers instead of the object, and
1496             # never access the object again[, implying] that the object is garbage". This appears
1497             # to fully contradict both the above statement, the API documentation in java.lang.ref
1498             # regarding when a reference is "strongly reachable", and basic common sense. There is
1499             # no concrete set of limitations stated, however, seemingly implying the JIT could
1500             # decide your code would run faster by simply garbage collecting everything
1501             # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
1502             # entirely flying blind here. We add some fences and hope that its sufficient, but
1503             # with no specification to rely on, we cannot be certain of anything.
1504             #
1505             # TL;DR: The Java Language "Specification" provides no real guarantees on when an
1506             # object will be considered available for garbage collection once the JIT kicks in, so
1507             # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
1508             for idx, info in enumerate(argument_types):
1509                 if idx == 0 and takes_self:
1510                     out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
1511                 elif info.arg_name in default_constructor_args:
1512                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1513                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1514                         out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
1515                 elif info.c_ty != "void":
1516                     out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
1517
1518             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1519                 out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
1520
1521             if return_type_info.to_hu_conv is not None:
1522                 if not takes_self:
1523                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1524                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1525                 else:
1526                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1527
1528             for idx, info in enumerate(argument_types):
1529                 if idx == 0 and takes_self:
1530                     pass
1531                 elif info.arg_name in default_constructor_args:
1532                     for explode_arg in default_constructor_args[info.arg_name]:
1533                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1534                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1535                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1536                                                                                                expl_arg_name).replace(
1537                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1538                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1539                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1540                         out_java_struct += (
1541                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1542                     else:
1543                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1544
1545             if takes_self and not takes_self_as_ref:
1546                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1547             if return_type_info.to_hu_conv_name is not None:
1548                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1549             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1550                 out_java_struct += ("\t\treturn ret;\n")
1551             out_java_struct += ("\t}\n\n")
1552
1553         return (out_java, out_c, out_java_struct + extra_java_struct_out)
1554
1555     def cleanup(self):
1556         pass