Fix calling Java/TS methods that return strings
[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 = new {human_type}(null, {var_name});',
22             default = '{human_type} {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 java.io.File;
28 import java.io.InputStream;
29 import java.io.IOException;
30 import java.nio.file.Files;
31 import java.nio.file.Path;
32 import java.nio.file.StandardCopyOption;
33
34 public class bindings {
35         public static class VecOrSliceDef {
36                 public long dataptr;
37                 public long datalen;
38                 public long stride;
39                 public VecOrSliceDef(long dataptr, long datalen, long stride) {
40                         this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
41                 }
42         }
43         static {
44                 try {
45                         // Try to load natively first, this works on Android and in testing.
46                         System.loadLibrary(\"lightningjni\");
47                 } catch (UnsatisfiedLinkError system_load_err) {
48                         // Otherwise try to load from the library jar.
49                         File tmpdir = new File(System.getProperty("java.io.tmpdir"), "ldk-java-nativelib");
50                         tmpdir.mkdir(); // If it fails to create, assume it was there already
51                         tmpdir.deleteOnExit();
52                         String libname = "liblightningjni_" + System.getProperty("os.name").replaceAll(" ", "") +
53                                 "-" + System.getProperty("os.arch").replaceAll(" ", "") + ".nativelib";
54                         try (InputStream is = bindings.class.getResourceAsStream("/" + libname)) {
55                                 Path libpath = new File(tmpdir.toPath().toString(), "liblightningjni.so").toPath();
56                                 Files.copy(is, libpath, StandardCopyOption.REPLACE_EXISTING);
57                                 Runtime.getRuntime().load(libpath.toString());
58                         } catch (IOException e) {
59                                 System.err.println("Failed to load LDK native library.");
60                                 System.err.println("System LDK native library load failed with: " + system_load_err);
61                                 System.err.println("Resource-based LDK native library load failed with: " + e);
62                                 throw new IllegalArgumentException(e);
63                         }
64                 }
65                 init(java.lang.Enum.class, VecOrSliceDef.class);
66                 init_class_cache();
67                 if (!get_lib_version_string().equals(get_ldk_java_bindings_version()))
68                         throw new IllegalArgumentException("Compiled LDK library and LDK class failes do not match");
69                 // Fetching the LDK versions from C also checks that the header and binaries match
70                 get_ldk_c_bindings_version();
71                 get_ldk_version();
72         }
73         static native void init(java.lang.Class c, java.lang.Class slicedef);
74         static native void init_class_cache();
75         static native String get_lib_version_string();
76
77         public static String get_ldk_java_bindings_version() {
78                 return "<git_version_ldk_garbagecollected>";
79         }
80         public static native String get_ldk_c_bindings_version();
81         public static native String get_ldk_version();
82
83         public static native boolean deref_bool(long ptr);
84         public static native long deref_long(long ptr);
85         public static native void free_heap_ptr(long ptr);
86         public static native byte[] read_bytes(long ptr, long len);
87         public static native byte[] get_u8_slice_bytes(long slice_ptr);
88         public static native long bytes_to_u8_vec(byte[] bytes);
89         public static native long new_txpointer_copy_data(byte[] txdata);
90         public static native void txpointer_free(long ptr);
91         public static native byte[] txpointer_get_buffer(long ptr);
92         public static native long vec_slice_len(long vec);
93         public static native long new_empty_slice_vec();
94
95 """
96
97         self.bindings_footer = "}\n"
98
99         self.util_fn_pfx = """package org.ldk.structs;
100 import org.ldk.impl.bindings;
101 import java.util.Arrays;
102 import javax.annotation.Nullable;
103 import org.ldk.enums.*;
104
105 public class UtilMethods {
106 """
107         self.util_fn_sfx = "}"
108         self.common_base = """package org.ldk.structs;
109 import java.util.LinkedList;
110 class CommonBase {
111         long ptr;
112         LinkedList<Object> ptrs_to = new LinkedList();
113         protected CommonBase(long ptr) { assert ptr > 1024; this.ptr = ptr; }
114 }
115 """
116
117         self.c_file_pfx = """#include <jni.h>
118 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
119 #define int64_t jlong
120 #include \"org_ldk_impl_bindings.h\"
121 #include <lightning.h>
122 #include <string.h>
123 #include <stdatomic.h>
124 #include <stdlib.h>
125
126 """
127
128         if self.target == Target.ANDROID:
129             self.c_file_pfx = self.c_file_pfx + """
130 #include <android/log.h>
131 #define DEBUG_PRINT(...) __android_log_print(ANDROID_LOG_ERROR, "LDK", __VA_ARGS__)
132
133 #include <unistd.h>
134 #include <pthread.h>
135 static void* redirect_stderr(void* ignored) {
136         int pipes[2];
137         pipe(pipes);
138         dup2(pipes[1], STDERR_FILENO);
139         char buf[8192];
140         memset(buf, 0, 8192);
141         ssize_t len;
142         while ((len = read(pipes[0], buf, 8191)) > 0) {
143                 DEBUG_PRINT("%s\\n", buf);
144                 memset(buf, 0, 8192);
145         }
146         DEBUG_PRINT("End of stderr???\\n");
147         return 0;
148 }
149 void __attribute__((constructor)) spawn_stderr_redirection() {
150         pthread_t thread;
151         pthread_create(&thread, NULL, &redirect_stderr, NULL);
152 }
153 """
154         else:
155             self.c_file_pfx = self.c_file_pfx + "#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)\n"
156
157         if not DEBUG or sys.platform == "darwin":
158             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
159 #define FREE(p) if ((uint64_t)(p) > 1024) { free(p); }
160 """
161         if not DEBUG:
162             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
163 #define CHECK(a)
164 """
165         if DEBUG:
166             self.c_file_pfx = self.c_file_pfx + """#include <assert.h>
167 // Always run a, then assert it is true:
168 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
169 // Assert a is true or do nothing
170 #define CHECK(a) DO_ASSERT(a)
171
172 void __attribute__((constructor)) debug_log_version() {
173         if (check_get_ldk_version() == NULL)
174                 DEBUG_PRINT("LDK version did not match the header we built against\\n");
175         if (check_get_ldk_bindings_version() == NULL)
176                 DEBUG_PRINT("LDK C Bindings version did not match the header we built against\\n");
177         DEBUG_PRINT("Loaded LDK-Java Bindings with LDK %s and LDK-C-Bindings %s\\n", check_get_ldk_version(), check_get_ldk_bindings_version());
178 }
179 """
180
181             if sys.platform != "darwin":
182                 self.c_file_pfx += """
183 // Running a leak check across all the allocations and frees of the JDK is a mess,
184 // so instead we implement our own naive leak checker here, relying on the -wrap
185 // linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
186 // and free'd in Rust or C across the generated bindings shared library.
187 #include <threads.h>
188 """
189
190                 if self.target == Target.ANDROID:
191                     self.c_file_pfx = self.c_file_pfx + """
192 #include <unwind.h>
193 #include <dlfcn.h>
194
195 // Implement the execinfo functions using _Unwind_backtrace. This seems to miss many Rust
196 // symbols, so we only use it on Android, where execinfo.h is unavailable.
197
198 struct BacktraceState {
199         void** current;
200         void** end;
201 };
202 static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context* context, void* arg) {
203         struct BacktraceState* state = (struct BacktraceState*)arg;
204         uintptr_t pc = _Unwind_GetIP(context);
205         if (pc) {
206                 if (state->current == state->end) {
207                         return _URC_END_OF_STACK;
208                 } else {
209                         *state->current++ = (void*)(pc);
210                 }
211         }
212         return _URC_NO_REASON;
213 }
214
215 int backtrace(void** buffer, int max) {
216         struct BacktraceState state = { buffer, buffer + max };
217         _Unwind_Backtrace(unwind_callback, &state);
218         return state.current - buffer;
219 }
220
221 void backtrace_symbols_fd(void ** buffer, int count, int _fd) {
222         for (int idx = 0; idx < count; ++idx) {
223                 Dl_info info;
224                 if (dladdr(buffer[idx], &info) && info.dli_sname) {
225                         DEBUG_PRINT("%p: %s", buffer[idx], info.dli_sname);
226                 } else {
227                         DEBUG_PRINT("%p: ???", buffer[idx]);
228                 }
229         }
230 }
231 """
232                 else:
233                     self.c_file_pfx = self.c_file_pfx + "#include <execinfo.h>\n"
234                 self.c_file_pfx = self.c_file_pfx + """
235 #include <unistd.h>
236 static mtx_t allocation_mtx;
237
238 void __attribute__((constructor)) init_mtx() {
239         DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
240 }
241
242 #define BT_MAX 128
243 typedef struct allocation {
244         struct allocation* next;
245         void* ptr;
246         const char* struct_name;
247         void* bt[BT_MAX];
248         int bt_len;
249         unsigned long alloc_len;
250 } allocation;
251 static allocation* allocation_ll = NULL;
252
253 void* __real_malloc(size_t len);
254 void* __real_calloc(size_t nmemb, size_t len);
255 static void new_allocation(void* res, const char* struct_name, size_t len) {
256         allocation* new_alloc = __real_malloc(sizeof(allocation));
257         new_alloc->ptr = res;
258         new_alloc->struct_name = struct_name;
259         new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
260         new_alloc->alloc_len = len;
261         DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
262         new_alloc->next = allocation_ll;
263         allocation_ll = new_alloc;
264         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
265 }
266 static void* MALLOC(size_t len, const char* struct_name) {
267         void* res = __real_malloc(len);
268         new_allocation(res, struct_name, len);
269         return res;
270 }
271 void __real_free(void* ptr);
272 static void alloc_freed(void* ptr) {
273         allocation* p = NULL;
274         DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
275         allocation* it = allocation_ll;
276         while (it->ptr != ptr) {
277                 p = it; it = it->next;
278                 if (it == NULL) {
279                         DEBUG_PRINT("Tried to free unknown pointer %p at:\\n", ptr);
280                         void* bt[BT_MAX];
281                         int bt_len = backtrace(bt, BT_MAX);
282                         backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
283                         DEBUG_PRINT("\\n\\n");
284                         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
285                         return; // addrsan should catch malloc-unknown and print more info than we have
286                 }
287         }
288         if (p) { p->next = it->next; } else { allocation_ll = it->next; }
289         DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
290         DO_ASSERT(it->ptr == ptr);
291         __real_free(it);
292 }
293 static void FREE(void* ptr) {
294         if ((uint64_t)ptr < 1024) return; // Rust loves to create pointers to the NULL page for dummys
295         alloc_freed(ptr);
296         __real_free(ptr);
297 }
298
299 void* __wrap_malloc(size_t len) {
300         void* res = __real_malloc(len);
301         new_allocation(res, "malloc call", len);
302         return res;
303 }
304 void* __wrap_calloc(size_t nmemb, size_t len) {
305         void* res = __real_calloc(nmemb, len);
306         new_allocation(res, "calloc call", len);
307         return res;
308 }
309 void __wrap_free(void* ptr) {
310         if (ptr == NULL) return;
311         alloc_freed(ptr);
312         __real_free(ptr);
313 }
314
315 void* __real_realloc(void* ptr, size_t newlen);
316 void* __wrap_realloc(void* ptr, size_t len) {
317         if (ptr != NULL) alloc_freed(ptr);
318         void* res = __real_realloc(ptr, len);
319         new_allocation(res, "realloc call", len);
320         return res;
321 }
322 void __wrap_reallocarray(void* ptr, size_t new_sz) {
323         // Rust doesn't seem to use reallocarray currently
324         DO_ASSERT(false);
325 }
326
327 void __attribute__((destructor)) check_leaks() {
328         unsigned long alloc_count = 0;
329         unsigned long alloc_size = 0;
330         DEBUG_PRINT("The following LDK-allocated blocks still remain.\\n");
331         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
332         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
333         for (allocation* a = allocation_ll; a != NULL; a = a->next) {
334                 DEBUG_PRINT("%s %p (%lu bytes) remains:\\n", a->struct_name, a->ptr, a->alloc_len);
335                 backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
336                 DEBUG_PRINT("\\n\\n");
337                 alloc_count++;
338                 alloc_size += a->alloc_len;
339         }
340         DEBUG_PRINT("%lu allocations remained for %lu bytes.\\n", alloc_count, alloc_size);
341         DEBUG_PRINT("Note that this is only accurate if System.gc(); System.runFinalization()\\n");
342         DEBUG_PRINT("was called prior to exit after all LDK objects were out of scope.\\n");
343 }
344 """
345         self.c_file_pfx = self.c_file_pfx + """
346 static jmethodID ordinal_meth = NULL;
347 static jmethodID slicedef_meth = NULL;
348 static jclass slicedef_cls = NULL;
349 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
350         ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
351         CHECK(ordinal_meth != NULL);
352         slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
353         CHECK(slicedef_meth != NULL);
354         slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
355         CHECK(slicedef_cls != NULL);
356 }
357
358 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
359         return *((bool*)ptr);
360 }
361 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
362         return *((long*)ptr);
363 }
364 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
365         FREE((void*)ptr);
366 }
367 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * env, jclass _b, jlong ptr, jlong len) {
368         jbyteArray ret_arr = (*env)->NewByteArray(env, len);
369         (*env)->SetByteArrayRegion(env, ret_arr, 0, len, (unsigned char*)ptr);
370         return ret_arr;
371 }
372 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * env, jclass _b, jlong slice_ptr) {
373         LDKu8slice *slice = (LDKu8slice*)slice_ptr;
374         jbyteArray ret_arr = (*env)->NewByteArray(env, slice->datalen);
375         (*env)->SetByteArrayRegion(env, ret_arr, 0, slice->datalen, slice->data);
376         return ret_arr;
377 }
378 JNIEXPORT int64_t impl_bindings_bytes_1to_1u8_1vec (JNIEnv * env, jclass _b, jbyteArray bytes) {
379         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
380         vec->datalen = (*env)->GetArrayLength(env, bytes);
381         vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
382         (*env)->GetByteArrayRegion (env, bytes, 0, vec->datalen, vec->data);
383         return (uint64_t)vec;
384 }
385 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_txpointer_1get_1buffer (JNIEnv * env, jclass _b, jlong ptr) {
386         LDKTransaction *txdata = (LDKTransaction*)ptr;
387         LDKu8slice slice;
388         slice.data = txdata->data;
389         slice.datalen = txdata->datalen;
390         return Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes(env, _b, (uint64_t)&slice);
391 }
392 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
393         LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
394         txdata->datalen = (*env)->GetArrayLength(env, bytes);
395         txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
396         txdata->data_is_owned = false;
397         (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
398         return (uint64_t)txdata;
399 }
400 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_txpointer_1free (JNIEnv * env, jclass _b, jlong ptr) {
401         LDKTransaction *tx = (LDKTransaction*)ptr;
402         tx->data_is_owned = true;
403         Transaction_free(*tx);
404         FREE((void*)ptr);
405 }
406 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
407         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
408         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
409         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_MessageSendEventZ, datalen), "Vec<*> needs to be mapped identically");
410         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_EventZ, datalen), "Vec<*> needs to be mapped identically");
411         _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_C2Tuple_usizeTransactionZZ, datalen), "Vec<*> needs to be mapped identically");
412         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
413         return (uint64_t)vec->datalen;
414 }
415 JNIEXPORT int64_t JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * env, jclass _b) {
416         // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
417         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
418         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
419         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
420         _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
421         LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
422         vec->data = NULL;
423         vec->datalen = 0;
424         return (uint64_t)vec;
425 }
426
427 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
428 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
429 _Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
430 _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
431
432 _Static_assert(sizeof(jlong) == sizeof(int64_t), "We assume that j-types are the same as C types");
433 _Static_assert(sizeof(jbyte) == sizeof(char), "We assume that j-types are the same as C types");
434 _Static_assert(sizeof(void*) <= 8, "Pointers must fit into 64 bits");
435
436 typedef jlongArray int64_tArray;
437 typedef jbyteArray int8_tArray;
438
439 static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
440         // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
441         char* conv_buf = MALLOC(len + 1, "str conv buf");
442         memcpy(conv_buf, chars, len);
443         conv_buf[len] = 0;
444         jstring ret = (*env)->NewStringUTF(env, conv_buf);
445         FREE(conv_buf);
446         return ret;
447 }
448 static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
449         uint64_t str_len = (*env)->GetStringUTFLength(env, str);
450         char* newchars = MALLOC(str_len + 1, "String chars");
451         const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
452         memcpy(newchars, jchars, str_len);
453         newchars[str_len] = 0;
454         (*env)->ReleaseStringUTFChars(env, str, jchars);
455         LDKStr res = {
456                 .chars = newchars,
457                 .len = str_len,
458                 .chars_is_owned = true
459         };
460         return res;
461 }
462
463 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1lib_1version_1string(JNIEnv *env, jclass _c) {
464         return str_ref_to_java(env, "<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
465 }
466 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1c_1bindings_1version(JNIEnv *env, jclass _c) {
467         return str_ref_to_java(env, check_get_ldk_bindings_version(), strlen(check_get_ldk_bindings_version()));
468 }
469 JNIEXPORT jstring JNICALL Java_org_ldk_impl_bindings_get_1ldk_1version(JNIEnv *env, jclass _c) {
470         return str_ref_to_java(env, check_get_ldk_version(), strlen(check_get_ldk_version()));
471 }
472 """
473
474         self.hu_struct_file_prefix = """package org.ldk.structs;
475
476 import org.ldk.impl.bindings;
477 import org.ldk.enums.*;
478 import org.ldk.util.*;
479 import java.util.Arrays;
480 import javax.annotation.Nullable;
481
482 """
483         self.c_fn_ty_pfx = "JNIEXPORT "
484         self.c_fn_args_pfx = "JNIEnv *env, jclass clz"
485         self.file_ext = ".java"
486         self.ptr_c_ty = "int64_t"
487         self.ptr_native_ty = "long"
488         self.result_c_ty = "jclass"
489         self.ptr_arr = "jobjectArray"
490         self.is_arr_some_check = ("", " != NULL")
491         self.get_native_arr_len_call = ("(*env)->GetArrayLength(env, ", ")")
492
493     def construct_jenv(self):
494         res =  "JNIEnv *env;\n"
495         res += "jint get_jenv_res = (*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_6);\n"
496         res += "if (get_jenv_res == JNI_EDETACHED) {\n"
497         if self.target == Target.ANDROID:
498             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, &env, NULL) == JNI_OK);\n"
499         else:
500             res += "\tDO_ASSERT((*j_calls->vm)->AttachCurrentThread(j_calls->vm, (void**)&env, NULL) == JNI_OK);\n"
501         res += "} else {\n"
502         res += "\tDO_ASSERT(get_jenv_res == JNI_OK);\n"
503         res += "}\n"
504         return res
505     def deconstruct_jenv(self):
506         res = "if (get_jenv_res == JNI_EDETACHED) {\n"
507         res += "\tDO_ASSERT((*j_calls->vm)->DetachCurrentThread(j_calls->vm) == JNI_OK);\n"
508         res += "}\n"
509         return res
510
511     def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
512         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
513             return "(*env)->ReleasePrimitiveArrayCritical(env, " + arr_var + ", " + arr_ptr_var + ", 0)"
514         return None
515     def create_native_arr_call(self, arr_len, ty_info):
516         if ty_info.c_ty == "int8_tArray":
517             return "(*env)->NewByteArray(env, " + arr_len + ")"
518         elif ty_info.subty.c_ty.endswith("Array"):
519             clz_var = ty_info.java_fn_ty_arg[1:].replace("[", "arr_of_")
520             self.c_array_class_caches.add(clz_var)
521             return "(*env)->NewObjectArray(env, " + arr_len + ", " + clz_var + "_clz, NULL);\n"
522         else:
523             return "(*env)->New" + ty_info.java_ty.strip("[]").title() + "Array(env, " + arr_len + ")"
524     def set_native_arr_contents(self, arr_name, arr_len, ty_info):
525         if ty_info.c_ty == "int8_tArray":
526             return ("(*env)->SetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", ", ")")
527         else:
528             assert False
529     def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
530         if ty_info.c_ty == "int8_tArray":
531             if copy:
532                 return "(*env)->GetByteArrayRegion(env, " + arr_name + ", 0, " + arr_len + ", " + dest_name + ")"
533             else:
534                 return "(*env)->GetByteArrayElements (env, " + arr_name + ", NULL)"
535         elif not ty_info.java_ty[:len(ty_info.java_ty) - 2].endswith("[]"):
536             return "(*env)->Get" + ty_info.subty.java_ty.title() + "ArrayElements (env, " + arr_name + ", NULL)"
537         else:
538             return None
539     def get_native_arr_elem(self, arr_name, idxc, ty_info):
540         if self.get_native_arr_contents(arr_name, "", "", ty_info, False) is None:
541             return "(*env)->GetObjectArrayElement(env, " + arr_name + ", " + idxc + ")"
542         else:
543             assert False # Only called if above is None
544     def get_native_arr_ptr_call(self, ty_info):
545         if ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"):
546             return None
547         return ("(*env)->GetPrimitiveArrayCritical(env, ", ", NULL)")
548     def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
549         if ty_info.subty is None or not ty_info.subty.c_ty.endswith("Array"):
550             return None
551         return "(*env)->SetObjectArrayElement(env, " + arr_name + ", " + idxc + ", " + entry_access + ")"
552     def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
553         if ty_info.c_ty == "int8_tArray":
554             return "(*env)->ReleaseByteArrayElements(env, " + arr_name + ", (int8_t*)" + dest_name + ", 0);"
555         else:
556             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
557
558     def str_ref_to_native_call(self, var_name, str_len):
559         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
560     def str_ref_to_c_call(self, var_name):
561         return "java_to_owned_str(env, " + var_name + ")"
562
563     def c_fn_name_define_pfx(self, fn_name, has_args):
564         if has_args:
565             return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz, "
566         return "JNICALL Java_org_ldk_impl_bindings_" + fn_name.replace("_", "_1") + "(JNIEnv *env, jclass clz"
567
568     def init_str(self):
569         res = ""
570         for ty in sorted(self.c_array_class_caches):
571             res = res + "static jclass " + ty + "_clz = NULL;\n"
572         res = res + "JNIEXPORT void Java_org_ldk_impl_bindings_init_1class_1cache(JNIEnv * env, jclass clz) {\n"
573         for ty in sorted(self.c_array_class_caches):
574             res = res + "\t" + ty + "_clz = (*env)->FindClass(env, \"" + ty.replace("arr_of_", "[") + "\");\n"
575             res = res + "\tCHECK(" + ty + "_clz != NULL);\n"
576             res = res + "\t" + ty + "_clz = (*env)->NewGlobalRef(env, " + ty + "_clz);\n"
577         res = res + "}\n"
578         return res
579
580     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
581         out_java_enum = "package org.ldk.enums;\n\n"
582         out_java = ""
583         out_c = ""
584         out_c = out_c + "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
585         out_c = out_c + "\tswitch ((*env)->CallIntMethod(env, clz, ordinal_meth)) {\n"
586
587         if enum_doc_comment is not None:
588             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
589         out_java_enum += "public enum " + struct_name + " {\n"
590         ord_v = 0
591         for var in variants:
592             out_java_enum = out_java_enum + "\t" + var + ",\n"
593             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
594             ord_v = ord_v + 1
595         out_java_enum = out_java_enum + "\t; static native void init();\n"
596         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
597         out_java_enum = out_java_enum + "}"
598         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
599         out_c = out_c + "\t}\n"
600         out_c = out_c + "\tabort();\n"
601         out_c = out_c + "}\n"
602
603         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
604         for var in variants:
605             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
606         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"
607         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
608         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
609         for var in variants:
610             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
611             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
612         out_c = out_c + "}\n"
613         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
614         out_c = out_c + "\tswitch (val) {\n"
615         ord_v = 0
616         for var in variants:
617             out_c = out_c + "\t\tcase " + var + ":\n"
618             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
619             ord_v = ord_v + 1
620         out_c = out_c + "\t\tdefault: abort();\n"
621         out_c = out_c + "\t}\n"
622         out_c = out_c + "}\n\n"
623
624         return (out_c, out_java_enum, out_java)
625
626     def c_unitary_enum_to_native_call(self, ty_info):
627         return (ty_info.rust_obj + "_to_java(env, ", ")")
628     def native_unitary_enum_to_c_call(self, ty_info):
629         return (ty_info.rust_obj + "_from_java(env, ", ")")
630
631     def c_complex_enum_pfx(self, struct_name, variants, init_meth_jty_strs):
632         out_c = ""
633         for var in variants:
634             out_c = out_c + "static jclass " + struct_name + "_" + var + "_class = NULL;\n"
635             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
636         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"
637         for var_name in variants:
638             out_c = out_c + "\t" + struct_name + "_" + var_name + "_class =\n"
639             if self.target == Target.ANDROID:
640                 out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
641             else:
642                 out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n"
643             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
644             out_c = 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"
645             out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
646         out_c = out_c + "}\n"
647         return out_c
648
649     def c_complex_enum_pass_ty(self, struct_name):
650         return "jobject"
651
652     def c_constr_native_complex_enum(self, struct_name, variant, c_params):
653         ret = "(*env)->NewObject(env, " + struct_name + "_" + variant + "_class, " + struct_name + "_" + variant + "_meth"
654         for param in c_params:
655             ret = ret + ", " + param
656         return ret + ")"
657
658     def native_c_map_trait(self, struct_name, field_vars, flattened_field_vars, field_fns, trait_doc_comment):
659         out_java_trait = ""
660         out_java = ""
661
662         # First generate most of the Java code, note that we need information about java method argument strings for C
663         out_java_trait = out_java_trait + self.hu_struct_file_prefix
664         if trait_doc_comment is not None:
665             out_java_trait += "/**\n * " + trait_doc_comment.replace("\n", "\n * ") + "\n */\n"
666         out_java_trait += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
667         out_java_trait = out_java_trait + "public class " + struct_name.replace("LDK","") + " extends CommonBase {\n"
668         out_java_trait = out_java_trait + "\tfinal bindings." + struct_name + " bindings_instance;\n"
669         out_java_trait = out_java_trait + "\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }\n"
670         out_java_trait = out_java_trait + "\tprivate " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg"
671         for var in flattened_field_vars:
672             if isinstance(var, ConvInfo):
673                 out_java_trait = out_java_trait + ", " + var.java_hu_ty + " " + var.arg_name
674             else:
675                 out_java_trait = out_java_trait + ", bindings." + var[0] + " " + var[1]
676         out_java_trait = out_java_trait + ") {\n"
677         out_java_trait = out_java_trait + "\t\tsuper(bindings." + struct_name + "_new(arg"
678         for var in flattened_field_vars:
679             if isinstance(var, ConvInfo):
680                 if var.from_hu_conv is not None:
681                     out_java_trait = out_java_trait + ", " + var.from_hu_conv[0]
682                 else:
683                     out_java_trait = out_java_trait + ", " + var.arg_name
684             else:
685                 out_java_trait = out_java_trait + ", " + var[1]
686         out_java_trait = out_java_trait + "));\n"
687         out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(arg);\n"
688         for var in flattened_field_vars:
689             if isinstance(var, ConvInfo):
690                 if var.from_hu_conv is not None and var.from_hu_conv[1] != "":
691                     out_java_trait = out_java_trait + "\t\t" + var.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n"
692             else:
693                 out_java_trait = out_java_trait + "\t\tthis.ptrs_to.add(" + var[1] + ");\n"
694         out_java_trait = out_java_trait + "\t\tthis.bindings_instance = arg;\n"
695         out_java_trait = out_java_trait + "\t}\n"
696         out_java_trait = out_java_trait + "\t@Override @SuppressWarnings(\"deprecation\")\n"
697         out_java_trait = out_java_trait + "\tprotected void finalize() throws Throwable {\n"
698         out_java_trait = out_java_trait + "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
699         out_java_trait = out_java_trait + "\t}\n\n"
700
701         java_trait_constr = "\tprivate static class " + struct_name + "Holder { " + struct_name.replace("LDK", "") + " held; }\n"
702         java_trait_constr = java_trait_constr + "\tpublic static " + struct_name.replace("LDK", "") + " new_impl(" + struct_name.replace("LDK", "") + "Interface arg"
703         for var in flattened_field_vars:
704             if isinstance(var, ConvInfo):
705                 java_trait_constr = java_trait_constr + ", " + var.java_hu_ty + " " + var.arg_name
706             else:
707                 # Ideally we'd be able to take any instance of the interface, but our C code can only represent
708                 # Java-implemented version, so we require users pass a Java implementation here :/
709                 java_trait_constr = java_trait_constr + ", " + var[0].replace("LDK", "") + "." + var[0].replace("LDK", "") + "Interface " + var[1] + "_impl"
710         java_trait_constr = java_trait_constr + ") {\n\t\tfinal " + struct_name + "Holder impl_holder = new " + struct_name + "Holder();\n"
711         java_trait_constr = java_trait_constr + "\t\timpl_holder.held = new " + struct_name.replace("LDK", "") + "(new bindings." + struct_name + "() {\n"
712         out_java_trait = out_java_trait + "\tpublic static interface " + struct_name.replace("LDK", "") + "Interface {\n"
713         out_java = out_java + "\tpublic interface " + struct_name + " {\n"
714         java_meths = []
715         for fn_line in field_fns:
716             java_meth_descr = "("
717             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
718                 out_java = out_java + "\t\t " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
719                 java_trait_constr = java_trait_constr + "\t\t\t@Override public " + fn_line.ret_ty_info.java_ty + " " + fn_line.fn_name + "("
720                 out_java_trait += "\t\t/**\n\t\t * " + fn_line.docs.replace("\n", "\n\t\t * ") + "\n\t\t */\n"
721                 out_java_trait = out_java_trait + "\t\t" + fn_line.ret_ty_info.java_hu_ty + " " + fn_line.fn_name + "("
722
723                 for idx, arg_conv_info in enumerate(fn_line.args_ty):
724                     if idx >= 1:
725                         out_java = out_java + ", "
726                         java_trait_constr = java_trait_constr + ", "
727                         out_java_trait = out_java_trait + ", "
728                     out_java = out_java + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
729                     out_java_trait = out_java_trait + arg_conv_info.java_hu_ty + " " + arg_conv_info.arg_name
730                     java_trait_constr = java_trait_constr + arg_conv_info.java_ty + " " + arg_conv_info.arg_name
731                     java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
732                 java_meth_descr = java_meth_descr + ")" + fn_line.ret_ty_info.java_fn_ty_arg
733                 java_meths.append((fn_line.fn_name, java_meth_descr))
734
735                 out_java = out_java + ");\n"
736                 out_java_trait = out_java_trait + ");\n"
737                 java_trait_constr = java_trait_constr + ") {\n"
738
739                 for arg_info in fn_line.args_ty:
740                     if arg_info.to_hu_conv is not None:
741                         java_trait_constr = java_trait_constr + "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"
742
743                 if fn_line.ret_ty_info.java_ty != "void":
744                     java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_hu_ty + " ret = arg." + fn_line.fn_name + "("
745                 else:
746                     java_trait_constr = java_trait_constr + "\t\t\t\targ." + fn_line.fn_name + "("
747
748                 for idx, arg_info in enumerate(fn_line.args_ty):
749                     if idx != 0:
750                         java_trait_constr = java_trait_constr + ", "
751                     if arg_info.to_hu_conv_name is not None:
752                         java_trait_constr = java_trait_constr + arg_info.to_hu_conv_name
753                     else:
754                         java_trait_constr = java_trait_constr + arg_info.arg_name
755
756                 java_trait_constr = java_trait_constr + ");\n"
757                 if fn_line.ret_ty_info.java_ty != "void":
758                     if fn_line.ret_ty_info.from_hu_conv is not None:
759                         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"
760                         if fn_line.ret_ty_info.from_hu_conv[1] != "":
761                             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"
762                         #if fn_line.ret_ty_info.rust_obj in result_types:
763                         java_trait_constr = java_trait_constr + "\t\t\t\treturn result;\n"
764                     else:
765                         java_trait_constr = java_trait_constr + "\t\t\t\treturn ret;\n"
766                 java_trait_constr = java_trait_constr + "\t\t\t}\n"
767         java_trait_constr = java_trait_constr + "\t\t}"
768         for var in field_vars:
769             if isinstance(var, ConvInfo):
770                 java_trait_constr = java_trait_constr + ", " + var.arg_name
771             else:
772                 java_trait_constr += ", " + var[1] + ".new_impl(" + var[1] + "_impl"
773                 for suparg in var[2]:
774                     if isinstance(suparg, ConvInfo):
775                         java_trait_constr += ", " + suparg.arg_name
776                     else:
777                         java_trait_constr += ", " + suparg[1]
778                 java_trait_constr += ").bindings_instance"
779                 for suparg in var[2]:
780                     if isinstance(suparg, ConvInfo):
781                         java_trait_constr += ", " + suparg.arg_name
782                     else:
783                         java_trait_constr += ", " + suparg[1]
784         out_java_trait = out_java_trait + "\t}\n"
785         out_java_trait = out_java_trait + java_trait_constr + ");\n\t\treturn impl_holder.held;\n\t}\n"
786
787         out_java = out_java + "\t}\n"
788
789         out_java = out_java + "\tpublic static native long " + struct_name + "_new(" + struct_name + " impl"
790         for var in flattened_field_vars:
791             if isinstance(var, ConvInfo):
792                 out_java = out_java + ", " + var.java_ty + " " + var.arg_name
793             else:
794                 out_java = out_java + ", " + var[0] + " " + var[1]
795         out_java = out_java + ");\n"
796
797         # Now that we've written out our java code (and created java_meths), generate C
798         out_c = "typedef struct " + struct_name + "_JCalls {\n"
799         out_c = out_c + "\tatomic_size_t refcnt;\n"
800         out_c = out_c + "\tJavaVM *vm;\n"
801         out_c = out_c + "\tjweak o;\n"
802         for var in flattened_field_vars:
803             if isinstance(var, ConvInfo):
804                 # We're a regular ol' field
805                 pass
806             else:
807                 # We're a supertrait
808                 out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
809         for fn in field_fns:
810             if fn.fn_name != "free" and fn.fn_name != "cloned":
811                 out_c = out_c + "\tjmethodID " + fn.fn_name + "_meth;\n"
812         out_c = out_c + "} " + struct_name + "_JCalls;\n"
813
814         for fn_line in field_fns:
815             if fn_line.fn_name == "free":
816                 out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
817                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
818                 out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
819                 out_c += "\t\t" + self.construct_jenv().replace("\n", "\n\t\t").strip() + "\n"
820                 out_c = out_c + "\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n"
821                 out_c += "\t\t" + self.deconstruct_jenv().replace("\n", "\n\t\t").strip() + "\n"
822                 out_c = out_c + "\t\tFREE(j_calls);\n"
823                 out_c = out_c + "\t}\n}\n"
824
825         for idx, fn_line in enumerate(field_fns):
826             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
827                 assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
828                 out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
829                 if fn_line.self_is_const:
830                     out_c = out_c + "const void* this_arg"
831                 else:
832                     out_c = out_c + "void* this_arg"
833
834                 for idx, arg in enumerate(fn_line.args_ty):
835                     out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]
836
837                 out_c = out_c + ") {\n"
838                 out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
839                 out_c += "\t" + self.construct_jenv().replace("\n", "\n\t").strip() + "\n"
840
841                 for arg_info in fn_line.args_ty:
842                     if arg_info.ret_conv is not None:
843                         out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
844                         out_c = out_c + arg_info.arg_name
845                         out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"
846
847                 out_c = out_c + "\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n"
848                 if fn_line.ret_ty_info.c_ty.endswith("Array"):
849                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
850                 elif fn_line.ret_ty_info.c_ty == "void":
851                     out_c += "\t(*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
852                 elif fn_line.ret_ty_info.java_ty == "String":
853                     # Manually write out String methods as they're just an Object
854                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
855                 elif not fn_line.ret_ty_info.passed_as_ptr:
856                     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"
857                 else:
858                     out_c = out_c + "\tuint64_t ret = (*env)->CallLongMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
859
860                 for idx, arg_info in enumerate(fn_line.args_ty):
861                     if arg_info.ret_conv is not None:
862                         out_c = out_c + ", " + arg_info.ret_conv_name
863                     else:
864                         out_c = out_c + ", " + arg_info.arg_name
865                 out_c = out_c + ");\n"
866
867                 out_c += "\tif ((*env)->ExceptionCheck(env)) {\n"
868                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
869                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
870                 out_c += "\t}\n"
871
872                 if fn_line.ret_ty_info.arg_conv is not None:
873                     out_c += "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n"
874                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
875                     out_c += "\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"
876                 else:
877                     out_c += "\t" + self.deconstruct_jenv().replace("\n", "\n\t").strip() + "\n"
878                     if not fn_line.ret_ty_info.passed_as_ptr and fn_line.ret_ty_info.c_ty != "void":
879                         out_c += "\treturn ret;\n"
880
881                 out_c = out_c + "}\n"
882
883         # If we can, write out a clone function whether we need one or not, as we use them in moving to rust
884         can_clone_with_ptr = True
885         for var in field_vars:
886             if isinstance(var, ConvInfo):
887                 can_clone_with_ptr = False
888         if can_clone_with_ptr:
889             out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
890             out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
891             out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
892             for var in field_vars:
893                 if not isinstance(var, ConvInfo):
894                     out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
895             out_c = out_c + "}\n"
896
897         out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (" + self.c_fn_args_pfx + ", jobject o"
898         for var in flattened_field_vars:
899             if isinstance(var, ConvInfo):
900                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
901             else:
902                 out_c = out_c + ", jobject " + var[1]
903         out_c = out_c + ") {\n"
904
905         out_c = out_c + "\tjclass c = (*env)->GetObjectClass(env, o);\n"
906         out_c = out_c + "\tCHECK(c != NULL);\n"
907         out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
908         out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
909         out_c = out_c + "\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n"
910         out_c = out_c + "\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n"
911
912         for (fn_name, java_meth_descr) in java_meths:
913             if fn_name != "free" and fn_name != "cloned":
914                 out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
915                 out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"
916
917         for var in flattened_field_vars:
918             if isinstance(var, ConvInfo) and var.arg_conv is not None:
919                 out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
920         out_c = out_c + "\n\t" + struct_name + " ret = {\n"
921         out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
922         for fn_line in field_fns:
923             if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
924                 out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
925             elif fn_line.fn_name == "free":
926                 out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
927             else:
928                 out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
929         for var in field_vars:
930             if isinstance(var, ConvInfo):
931                 if var.arg_conv_name is not None:
932                     out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
933                     out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
934                 else:
935                     out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
936                     out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
937             else:
938                 out_c += "\t\t." + var[1] + " = " + var[0] + "_init(env, clz, " + var[1]
939                 for suparg in var[2]:
940                     if isinstance(suparg, ConvInfo):
941                         out_c = out_c + ", " + suparg.arg_name
942                     else:
943                         out_c = out_c + ", " + suparg[1]
944                 out_c += "),\n"
945         out_c = out_c + "\t};\n"
946         for var in flattened_field_vars:
947             if not isinstance(var, ConvInfo):
948                 out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
949         out_c = out_c + "\treturn ret;\n"
950         out_c = out_c + "}\n"
951
952         out_c = out_c + self.c_fn_ty_pfx + "int64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "jobject o"
953         for var in flattened_field_vars:
954             if isinstance(var, ConvInfo):
955                 out_c = out_c + ", " + var.c_ty + " " + var.arg_name
956             else:
957                 out_c = out_c + ", jobject " + var[1]
958         out_c = out_c + ") {\n"
959         out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
960         out_c = out_c + "\t*res_ptr = " + struct_name + "_init(env, clz, o"
961         for var in flattened_field_vars:
962             if isinstance(var, ConvInfo):
963                 out_c = out_c + ", " + var.arg_name
964             else:
965                 out_c = out_c + ", " + var[1]
966         out_c = out_c + ");\n"
967         out_c = out_c + "\treturn (uint64_t)res_ptr;\n"
968         out_c = out_c + "}\n"
969
970         for var in flattened_field_vars:
971             if not isinstance(var, ConvInfo):
972                 out_java_trait += "\n\t/**\n"
973                 out_java_trait += "\t * Gets the underlying " + var[1] + ".\n"
974                 out_java_trait += "\t */\n"
975                 underscore_name = ''.join('_' + c.lower() if c.isupper() else c for c in var[1]).strip('_')
976                 out_java_trait += "\tpublic " + var[1] + " get_" + underscore_name + "() {\n"
977                 out_java_trait += "\t\t" + var[1] + " res = new " + var[1] + "(null, bindings." + struct_name + "_get_" + var[1] + "(this.ptr));\n"
978                 out_java_trait += "\t\tthis.ptrs_to.add(res);\n"
979                 out_java_trait += "\t\treturn res;\n"
980                 out_java_trait += "\t}\n"
981                 out_java_trait += "\n"
982
983                 out_java += "\tpublic static native long " + struct_name + "_get_" + var[1] + "(long arg);\n"
984
985                 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"
986                 out_c += "\t" + struct_name + " *inp = (" + struct_name + " *)(arg & ~1);\n"
987                 out_c += "\tuint64_t res_ptr = (uint64_t)&inp->" + var[1] + ";\n"
988                 out_c += "\tDO_ASSERT((res_ptr & 1) == 0);\n"
989                 out_c += "\treturn (int64_t)(res_ptr | 1);\n"
990                 out_c += "}\n"
991
992         return (out_java, out_java_trait, out_c)
993
994     def trait_struct_inc_refcnt(self, ty_info):
995         base_conv = "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
996         base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
997         base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_cloned(&" + ty_info.var_name + "_conv);\n}"
998         return base_conv
999
1000     def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
1001         java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")
1002         out_java_enum = ""
1003         out_java = ""
1004         out_c = ""
1005
1006         out_java_enum += (self.hu_struct_file_prefix)
1007         out_java_enum += "\n/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
1008         out_java_enum += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1009         out_java_enum += ("public class " + java_hu_type + " extends CommonBase {\n")
1010         out_java_enum += ("\tprivate " + java_hu_type + "(Object _dummy, long ptr) { super(ptr); }\n")
1011         out_java_enum += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1012         out_java_enum += ("\tprotected void finalize() throws Throwable {\n")
1013         out_java_enum += ("\t\tsuper.finalize();\n")
1014         out_java_enum += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK", "") + "_free(ptr); }\n")
1015         out_java_enum += ("\t}\n")
1016         out_java_enum += ("\tstatic " + java_hu_type + " constr_from_ptr(long ptr) {\n")
1017         out_java_enum += ("\t\tbindings." + struct_name + " raw_val = bindings." + struct_name + "_ref_from_ptr(ptr);\n")
1018         java_hu_subclasses = ""
1019
1020         init_meth_jty_strs = {}
1021
1022         out_java +=  ("\tpublic static class " + struct_name + " {\n")
1023         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
1024         for var in variant_list:
1025             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
1026             java_hu_subclasses = java_hu_subclasses + "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
1027             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
1028             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
1029             init_meth_jty_str = ""
1030             init_meth_params = ""
1031             init_meth_body = ""
1032             hu_conv_body = ""
1033             for idx, (field_ty, field_docs) in enumerate(var.fields):
1034                 if idx > 0:
1035                     init_meth_params = init_meth_params + ", "
1036
1037                 if field_ty.java_hu_ty == var.var_name:
1038                     field_path = field_ty.java_fn_ty_arg.strip("L;").replace("/", ".")
1039                     out_java += "\t\t\tpublic " + field_path + " " + field_ty.arg_name + ";\n"
1040                     java_hu_subclasses = java_hu_subclasses + "\t\tpublic final " + field_path + " " + field_ty.arg_name + ";\n"
1041                     init_meth_params = init_meth_params + field_path + " " + field_ty.arg_name
1042                 else:
1043                     out_java += "\t\t\tpublic " + field_ty.java_ty + " " + field_ty.arg_name + ";\n"
1044                     if field_docs is not None:
1045                         java_hu_subclasses += "\t\t/**\n\t\t * " + field_docs.replace("\n", "\n\t\t * ") + "\n\t\t*/\n"
1046                     java_hu_subclasses += "\t\t"
1047                     if field_ty.nullable:
1048                         java_hu_subclasses += "@Nullable "
1049                     java_hu_subclasses += "public final " + field_ty.java_hu_ty + " " + field_ty.arg_name + ";\n"
1050                     init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.arg_name
1051                 init_meth_body = init_meth_body + "this." + field_ty.arg_name + " = " + field_ty.arg_name + "; "
1052                 if field_ty.to_hu_conv is not None:
1053                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.java_ty + " " + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1054                     hu_conv_body = hu_conv_body + "\t\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
1055                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
1056                 else:
1057                     hu_conv_body = hu_conv_body + "\t\t\tthis." + field_ty.arg_name + " = obj." + field_ty.arg_name + ";\n"
1058                 init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
1059             out_java +=  ("\t\t\t" + var.var_name + "(" + init_meth_params + ") { ")
1060             out_java +=  (init_meth_body)
1061             out_java +=  ("}\n")
1062             out_java += ("\t\t}\n")
1063             out_java_enum += ("\t\t}\n")
1064             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"
1065             java_hu_subclasses = java_hu_subclasses + hu_conv_body
1066             java_hu_subclasses = java_hu_subclasses + "\t\t}\n\t}\n"
1067             init_meth_jty_strs[var.var_name] = init_meth_jty_str
1068         out_java += ("\t\tstatic native void init();\n")
1069         out_java += ("\t}\n")
1070         out_java_enum += ("\t\tassert false; return null; // Unreachable without extending the (internal) bindings interface\n\t}\n\n")
1071         out_java_enum += (java_hu_subclasses)
1072         out_java += ("\tstatic { " + struct_name + ".init(); }\n")
1073         out_java += ("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
1074
1075         out_c += (self.c_complex_enum_pfx(struct_name, [x.var_name for x in variant_list], init_meth_jty_strs))
1076
1077         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")
1078         out_c += ("\t" + struct_name + " *obj = (" + struct_name + "*)(ptr & ~1);\n")
1079         out_c += ("\tswitch(obj->tag) {\n")
1080         for var in variant_list:
1081             out_c += ("\t\tcase " + struct_name + "_" + var.var_name + ": {\n")
1082             c_params = []
1083             for idx, (field_map, field_docs) in enumerate(var.fields):
1084                 if field_map.ret_conv is not None:
1085                     out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
1086                     if var.tuple_variant:
1087                         out_c += "obj->" + camel_to_snake(var.var_name)
1088                     else:
1089                         out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
1090                     out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
1091                     c_params.append(field_map.ret_conv_name)
1092                 else:
1093                     if var.tuple_variant:
1094                         c_params.append("obj->" + camel_to_snake(var.var_name))
1095                     else:
1096                         c_params.append("obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name)
1097             out_c += ("\t\t\treturn " + self.c_constr_native_complex_enum(struct_name, var.var_name, c_params) + ";\n")
1098             out_c += ("\t\t}\n")
1099         out_c += ("\t\tdefault: abort();\n")
1100         out_c += ("\t}\n}\n")
1101         return (out_java, out_java_enum, out_c)
1102
1103     def map_opaque_struct(self, struct_name, struct_doc_comment):
1104         out_opaque_struct_human = ""
1105         out_opaque_struct_human += self.hu_struct_file_prefix
1106         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
1107         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
1108         out_opaque_struct_human += ("public class " + struct_name.replace("LDK","") + " extends CommonBase")
1109         if struct_name.startswith("LDKLocked"):
1110             out_opaque_struct_human += (" implements AutoCloseable")
1111         out_opaque_struct_human += (" {\n")
1112         out_opaque_struct_human += ("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
1113         if struct_name.startswith("LDKLocked"):
1114             out_opaque_struct_human += ("\t@Override public void close() {\n")
1115         else:
1116             out_opaque_struct_human += ("\t@Override @SuppressWarnings(\"deprecation\")\n")
1117             out_opaque_struct_human += ("\tprotected void finalize() throws Throwable {\n")
1118             out_opaque_struct_human += ("\t\tsuper.finalize();\n")
1119         out_opaque_struct_human += ("\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); }\n")
1120         out_opaque_struct_human += ("\t}\n\n")
1121         return out_opaque_struct_human
1122
1123
1124     def map_function(self, argument_types, c_call_string, method_name, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
1125         out_java = ""
1126         out_c = ""
1127         out_java_struct = None
1128
1129         out_java += ("\tpublic static native ")
1130         out_c += (self.c_fn_ty_pfx)
1131         out_c += (return_type_info.c_ty)
1132         out_java += (return_type_info.java_ty)
1133         if return_type_info.ret_conv is not None:
1134             ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
1135         out_java += (" " + method_name + "(")
1136         have_args = len(argument_types) > 1 or (len(argument_types) > 0 and argument_types[0].c_ty != "void")
1137         out_c += (" " + self.c_fn_name_define_pfx(method_name, have_args))
1138
1139         for idx, arg_conv_info in enumerate(argument_types):
1140             if idx != 0:
1141                 out_java += (", ")
1142                 out_c += (", ")
1143             if arg_conv_info.c_ty != "void":
1144                 out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
1145                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
1146
1147         out_java_struct = ""
1148         if not args_known:
1149             out_java_struct += ("\t// Skipped " + method_name + "\n")
1150         else:
1151             meth_n = method_name[len(struct_meth) + 1 if len(struct_meth) != 0 else 0:].strip("_")
1152             if doc_comment is not None:
1153                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
1154             if return_type_info.nullable:
1155                 out_java_struct += "\t@Nullable\n"
1156             if not takes_self:
1157                 if meth_n == "new":
1158                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " of("
1159                 elif meth_n == "default":
1160                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
1161                 else:
1162                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
1163             else:
1164                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
1165             for idx, arg in enumerate(argument_types):
1166                 if idx != 0:
1167                     if not takes_self or idx > 1:
1168                         out_java_struct += ", "
1169                 elif takes_self:
1170                     continue
1171                 if arg.java_ty != "void":
1172                     if arg.arg_name in default_constructor_args:
1173                         assert not arg.nullable
1174                         for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
1175                             if explode_idx != 0:
1176                                 out_java_struct += (", ")
1177                             out_java_struct += (
1178                                 explode_arg.java_hu_ty + " " + arg.arg_name + "_" + explode_arg.arg_name)
1179                     else:
1180                         if arg.nullable:
1181                             out_java_struct += "@Nullable "
1182                         ty_string = arg.java_hu_ty
1183                         if arg.java_fn_ty_arg[0] == "L" and arg.java_fn_ty_arg[len(arg.java_fn_ty_arg) - 1] == ";":
1184                             ty_string = arg.java_fn_ty_arg.strip("L;").replace("/", ".")
1185                         out_java_struct += ty_string + " " + arg.arg_name
1186         out_java += (");\n")
1187         out_c += (") {\n")
1188         if out_java_struct is not None:
1189             out_java_struct += (") {\n")
1190         for info in argument_types:
1191             if info.arg_conv is not None:
1192                 out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
1193         if return_type_info.ret_conv is not None:
1194             out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
1195         elif return_type_info.c_ty != "void":
1196             out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
1197         else:
1198             out_c += ("\t")
1199         if c_call_string is None:
1200             out_c += (method_name + "(")
1201         else:
1202             out_c += (c_call_string)
1203         for idx, info in enumerate(argument_types):
1204             if info.arg_conv_name is not None:
1205                 if idx != 0:
1206                     out_c += (", ")
1207                 elif c_call_string is not None:
1208                     continue
1209                 out_c += (info.arg_conv_name)
1210         out_c += (")")
1211         if return_type_info.ret_conv is not None:
1212             out_c += (ret_conv_sfx.replace('\n', '\n\t'))
1213         else:
1214             out_c += (";")
1215         for info in argument_types:
1216             if info.arg_conv_cleanup is not None:
1217                 out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
1218         if return_type_info.ret_conv is not None:
1219             out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
1220         elif return_type_info.c_ty != "void":
1221             out_c += ("\n\treturn ret_val;")
1222         out_c += ("\n}\n\n")
1223
1224         if args_known:
1225             out_java_struct += ("\t\t")
1226             if return_type_info.java_ty != "void":
1227                 out_java_struct += (return_type_info.java_ty + " ret = ")
1228             out_java_struct += ("bindings." + method_name + "(")
1229             for idx, info in enumerate(argument_types):
1230                 if idx != 0:
1231                     out_java_struct += (", ")
1232                 if idx == 0 and takes_self:
1233                     out_java_struct += ("this.ptr")
1234                 elif info.arg_name in default_constructor_args:
1235                     out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
1236                     for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
1237                         if explode_idx != 0:
1238                             out_java_struct += (", ")
1239                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1240                         if explode_arg.from_hu_conv is not None:
1241                             out_java_struct += (
1242                                 explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
1243                         else:
1244                             out_java_struct += (expl_arg_name)
1245                     out_java_struct += (")")
1246                 elif info.from_hu_conv is not None:
1247                     out_java_struct += (info.from_hu_conv[0])
1248                 else:
1249                     out_java_struct += (info.arg_name)
1250             out_java_struct += (");\n")
1251             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
1252                 out_java_struct += "\t\tif (ret < 1024) { return null; }\n"
1253
1254             if return_type_info.to_hu_conv is not None:
1255                 if not takes_self:
1256                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
1257                                                                                                                return_type_info.to_hu_conv_name) + "\n")
1258                 else:
1259                     out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")
1260
1261             for idx, info in enumerate(argument_types):
1262                 if idx == 0 and takes_self:
1263                     pass
1264                 elif info.arg_name in default_constructor_args:
1265                     for explode_arg in default_constructor_args[info.arg_name]:
1266                         expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
1267                         if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
1268                             out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
1269                                                                                                expl_arg_name).replace(
1270                                 "this", return_type_info.to_hu_conv_name) + ";\n")
1271                 elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
1272                     if not takes_self and return_type_info.to_hu_conv_name is not None:
1273                         out_java_struct += (
1274                             "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
1275                     else:
1276                         out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")
1277
1278             if takes_self and not takes_self_as_ref:
1279                 out_java_struct += "\t\t" + argument_types[0].from_hu_conv[1].replace("\n", "\n\t\t").replace("this_arg", "this") + ";\n"
1280             if return_type_info.to_hu_conv_name is not None:
1281                 out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
1282             elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
1283                 out_java_struct += ("\t\treturn ret;\n")
1284             out_java_struct += ("\t}\n\n")
1285
1286         return (out_java, out_c, out_java_struct)