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[ldk-java] / genbindings.py

diff --git a/genbindings.py b/genbindings.py
index a230ca09c456688f3d186b50e264932dd4c1e307..5f4edfc71a94489908a46b89e1d40ecfa48d5697 100755 (executable)
--- a/genbindings.py
+++ b/genbindings.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 import sys, re
 
 #!/usr/bin/env python3
 import sys, re
 

-if len(sys.argv) != 5:
-    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/output.c debug")
+if len(sys.argv) != 6:
+    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/enums/ /path/to/bindings/output.c debug")

     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 
     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 


@@ -43,12 +43,38 @@ class ConvInfo:
             out_java.write(" arg")
             out_c.write(" arg")
 
             out_java.write(" arg")
             out_c.write(" arg")
 

-with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[3], "w") as out_c:
+with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[4], "w") as out_c:

     opaque_structs = set()
     trait_structs = set()
     unitary_enums = set()
 
     opaque_structs = set()
     trait_structs = set()
     unitary_enums = set()
 

-    var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
+    def camel_to_snake(s):
+        # Convert camel case to snake case, in a way that appears to match cbindgen
+        con = "_"
+        ret = ""
+        lastchar = ""
+        lastund = False
+        for char in s:
+            if lastchar.isupper():
+                if not char.isupper() and not lastund:
+                    ret = ret + "_"
+                    lastund = True
+                else:
+                    lastund = False
+                ret = ret + lastchar.lower()
+            else:
+                ret = ret + lastchar
+                if char.isupper() and not lastund:
+                    ret = ret + "_"
+                    lastund = True
+                else:
+                    lastund = False
+            lastchar = char
+            if char.isnumeric():
+                lastund = True
+        return (ret + lastchar.lower()).strip("_")
+
+    var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([0-9]*)\]")

     var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
     def java_c_types(fn_arg, ret_arr_len):
         fn_arg = fn_arg.strip()
     var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
     def java_c_types(fn_arg, ret_arr_len):
         fn_arg = fn_arg.strip()


@@ -62,6 +88,11 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         is_ptr = False
         take_by_ptr = False
         rust_obj = None
         is_ptr = False
         take_by_ptr = False
         rust_obj = None

+        if fn_arg.startswith("LDKThirtyTwoBytes"):
+            fn_arg = "uint8_t (*" + fn_arg[18:] + ")[32]"
+            assert var_is_arr_regex.match(fn_arg[8:])
+            rust_obj = "LDKThirtyTwoBytes"
+

         if fn_arg.startswith("void"):
             java_ty = "void"
             c_ty = "void"
         if fn_arg.startswith("void"):
             java_ty = "void"
             c_ty = "void"


@@ -105,7 +136,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             if ma.group(1).strip() in unitary_enums:
                 java_ty = ma.group(1).strip()
                 c_ty = "jclass"
             if ma.group(1).strip() in unitary_enums:
                 java_ty = ma.group(1).strip()
                 c_ty = "jclass"

-                fn_ty_arg = "Lorg/ldk/impl/bindings$" + ma.group(1).strip() + ";"
+                fn_ty_arg = "Lorg/ldk/enums/" + ma.group(1).strip() + ";"

                 fn_arg = ma.group(2).strip()
                 rust_obj = ma.group(1).strip()
                 take_by_ptr = True
                 fn_arg = ma.group(2).strip()
                 rust_obj = ma.group(1).strip()
                 take_by_ptr = True


@@ -131,7 +162,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             java_ty = java_ty + "[]"
             c_ty = c_ty + "Array"
             if var_is_arr is not None:
             java_ty = java_ty + "[]"
             c_ty = c_ty + "Array"
             if var_is_arr is not None:

-                return TypeInfo(rust_obj=None, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,

                     passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2))
         return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
             is_ptr=is_ptr, var_name=fn_arg, arr_len=None)
                     passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2))
         return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
             is_ptr=is_ptr, var_name=fn_arg, arr_len=None)


@@ -152,19 +183,26 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 arr_name = "ret"
                 arr_len = ret_arr_len
             assert(ty_info.c_ty == "jbyteArray")
                 arr_name = "ret"
                 arr_len = ret_arr_len
             assert(ty_info.c_ty == "jbyteArray")

+            if ty_info.rust_obj is not None:
+                arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n" + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_ref.data);"
+                arr_access = ("", ".data")
+            else:
+                arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n" + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
+                arr_access = ("*", "")

             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n" +
-                    "(*_env)->GetByteArrayRegion (_env, """ + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" +
-                    "unsigned char (*""" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;",
+                arg_conv = arg_conv,

                 arg_conv_name = arr_name + "_ref",
                 ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" +
                 arg_conv_name = arr_name + "_ref",
                 ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" +

-                    "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", *",
-                    ");"),
+                    "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", " + arr_access[0],
+                    arr_access[1] + ");"),

                 ret_conv_name = arr_name + "_arr")
         elif ty_info.var_name != "":
             # If we have a parameter name, print it (noting that it may indicate its a pointer)
             if ty_info.rust_obj is not None:
                 assert(ty_info.passed_as_ptr)
                 ret_conv_name = arr_name + "_arr")
         elif ty_info.var_name != "":
             # If we have a parameter name, print it (noting that it may indicate its a pointer)
             if ty_info.rust_obj is not None:
                 assert(ty_info.passed_as_ptr)

+                opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"

                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,


@@ -172,6 +210,19 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                             arg_conv_name = ty_info.var_name + "_conv",
                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
                             ret_conv_name = ty_info.var_name + "_conv")
                             arg_conv_name = ty_info.var_name + "_conv",
                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
                             ret_conv_name = ty_info.var_name + "_conv")

+                    if ty_info.rust_obj in opaque_structs:
+                        ret_conv_suf = ";\nDO_ASSERT((((long)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
+                        ret_conv_suf = ret_conv_suf + "DO_ASSERT((((long)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
+                        ret_conv_suf = ret_conv_suf + "long " + ty_info.var_name + "_ref;\n"
+                        ret_conv_suf = ret_conv_suf + "if (" + ty_info.var_name + "_var.is_owned) {\n"
+                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner | 1;\n"
+                        ret_conv_suf = ret_conv_suf + "} else {\n"
+                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)&" + ty_info.var_name + "_var;\n"
+                        ret_conv_suf = ret_conv_suf + "}"
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv",
+                            ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", ret_conv_suf),
+                            ret_conv_name = ty_info.var_name + "_ref")

                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
                     if ty_info.rust_obj in trait_structs:
                         if not is_free:
                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
                     if ty_info.rust_obj in trait_structs:
                         if not is_free:


@@ -185,19 +236,18 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                             arg_conv_name = ty_info.var_name + "_conv",
                             ret_conv = ("CANT PASS TRAIT TO Java?", ""), ret_conv_name = "NO CONV POSSIBLE")
                     if ty_info.rust_obj != "LDKu8slice":
                             arg_conv_name = ty_info.var_name + "_conv",
                             ret_conv = ("CANT PASS TRAIT TO Java?", ""), ret_conv_name = "NO CONV POSSIBLE")
                     if ty_info.rust_obj != "LDKu8slice":

-                        # Don't bother free'ing slices passed in - we often pass them Rust -> Rust
+                        # Don't bother free'ing slices passed in - Rust doesn't auto-free the
+                        # underlying unlike Vecs, and it gives Java more freedom.

                         base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";
                         base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";

-                    if ty_info.rust_obj in opaque_structs:
-                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                            arg_conv = base_conv + "\n" + ty_info.var_name + "_conv.is_owned = true;",
-                            arg_conv_name = ty_info.var_name + "_conv",
-                            ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
-

                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv",
                         ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
                 else:
                     assert(not is_free)
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv",
                         ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
                 else:
                     assert(not is_free)

+                    if ty_info.rust_obj in opaque_structs:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv",
+                            ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed

                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
                         arg_conv_name = ty_info.var_name + "_conv",
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
                         arg_conv_name = ty_info.var_name + "_conv",


@@ -239,8 +289,8 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         # any _free function.
                         # To avoid any issues, we first assert that the incoming object is non-ref.
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         # any _free function.
                         # To avoid any issues, we first assert that the incoming object is non-ref.
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,

-                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";\nDO_ASSERT(ret->is_owned);\nret->is_owned = false;"),
-                            ret_conv_name = "(long)ret",
+                            ret_conv = (ty_info.rust_obj + " ret = ", ";\nDO_ASSERT(ret.is_owned);"),
+                            ret_conv_name = "((long)ret.inner) | 1",

                             arg_conv = None, arg_conv_name = None)
                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = None, arg_conv_name = None)
                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,


@@ -311,6 +361,136 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             out_c.write(";")
         out_c.write("\n}\n\n")
 
             out_c.write(";")
         out_c.write("\n}\n\n")
 

+    def map_unitary_enum(struct_name, field_lines):
+        with open(sys.argv[3] + "/" + struct_name + ".java", "w") as out_java_enum:
+            out_java_enum.write("package org.ldk.enums;\n\n")
+            unitary_enums.add(struct_name)
+            out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
+            out_c.write("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
+            ord_v = 0
+            for idx, struct_line in enumerate(field_lines):
+                if idx == 0:
+                    out_java_enum.write("public enum " + struct_name + " {\n")
+                elif idx == len(field_lines) - 3:
+                    assert(struct_line.endswith("_Sentinel,"))
+                elif idx == len(field_lines) - 2:
+                    out_java_enum.write("\t; static native void init();\n")
+                    out_java_enum.write("\tstatic { init(); }\n")
+                    out_java_enum.write("}")
+                    out_java.write("\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n")
+                elif idx == len(field_lines) - 1:
+                    assert(struct_line == "")
+                else:
+                    out_java_enum.write(struct_line + "\n")
+                    out_c.write("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
+                    ord_v = ord_v + 1
+            out_c.write("\t}\n")
+            out_c.write("\tabort();\n")
+            out_c.write("}\n")
+
+            ord_v = 0
+            out_c.write("static jclass " + struct_name + "_class = NULL;\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
+            out_c.write("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
+            out_c.write("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")
+            out_c.write("\tDO_ASSERT(" + struct_name + "_class != NULL);\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")
+                    out_c.write("\tDO_ASSERT(" + struct_name + "_" + variant + " != NULL);\n")
+            out_c.write("}\n")
+            out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
+            out_c.write("\tswitch (val) {\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("\t\tcase " + variant + ":\n")
+                    out_c.write("\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + variant + ");\n")
+                    ord_v = ord_v + 1
+            out_c.write("\t\tdefault: abort();\n")
+            out_c.write("\t}\n")
+            out_c.write("}\n\n")
+
+    def map_complex_enum(struct_name, union_enum_items):
+        tag_field_lines = union_enum_items["field_lines"]
+        init_meth_jty_strs = {}
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx == 0:
+                out_java.write("\tpublic static class " + struct_name + " {\n")
+                out_java.write("\t\tprivate " + struct_name + "() {}\n")
+            elif idx == len(tag_field_lines) - 3:
+                assert(struct_line.endswith("_Sentinel,"))
+            elif idx == len(tag_field_lines) - 2:
+                out_java.write("\t\tstatic native void init();\n")
+                out_java.write("\t}\n")
+            elif idx == len(tag_field_lines) - 1:
+                assert(struct_line == "")
+            else:
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_java.write("\t\tpublic final static class " + var_name + " extends " + struct_name + " {\n")
+                out_c.write("static jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
+                out_c.write("static jmethodID " + struct_name + "_" + var_name + "_meth = NULL;\n")
+                init_meth_jty_str = ""
+                init_meth_params = ""
+                init_meth_body = ""
+                if "LDK" + var_name in union_enum_items:
+                    enum_var_lines = union_enum_items["LDK" + var_name]
+                    for idx, field in enumerate(enum_var_lines):
+                        if idx != 0 and idx < len(enum_var_lines) - 2:
+                            field_ty = java_c_types(field.strip(' ;'), None)
+                            out_java.write("\t\t\tpublic " + field_ty.java_ty + " " + field_ty.var_name + ";\n")
+                            init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
+                            if idx > 1:
+                                init_meth_params = init_meth_params + ", "
+                            init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.var_name
+                            init_meth_body = init_meth_body + "this." + field_ty.var_name + " = " + field_ty.var_name + "; "
+                    out_java.write("\t\t\t" + var_name + "(" + init_meth_params + ") { ")
+                    out_java.write(init_meth_body)
+                    out_java.write("}\n")
+                out_java.write("\t\t}\n")
+                init_meth_jty_strs[var_name] = init_meth_jty_str
+        out_java.write("\tstatic { " + struct_name + ".init(); }\n")
+        out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
+
+        out_c.write("JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass _a) {\n")
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx != 0 and idx < len(tag_field_lines) - 3:
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_c.write("\t" + struct_name + "_" + var_name + "_class =\n")
+                out_c.write("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
+                out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_class != NULL);\n")
+                out_c.write("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
+                out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_meth != NULL);\n")
+        out_c.write("}\n")
+        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * env, jclass _c, jlong ptr) {\n")
+        out_c.write("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
+        out_c.write("\tswitch(obj->tag) {\n")
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx != 0 and idx < len(tag_field_lines) - 3:
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_c.write("\t\tcase " + struct_name + "_" + var_name + ": {\n")
+                c_params_text = ""
+                if "LDK" + var_name in union_enum_items:
+                    enum_var_lines = union_enum_items["LDK" + var_name]
+                    for idx, field in enumerate(enum_var_lines):
+                        if idx != 0 and idx < len(enum_var_lines) - 2:
+                            field_map = map_type(field.strip(' ;'), False, None, False)
+                            if field_map.ret_conv is not None:
+                                out_c.write("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t").replace("_env", "env"))
+                                out_c.write("obj->" + camel_to_snake(var_name) + "." + field_map.arg_name)
+                                out_c.write(field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
+                                c_params_text = c_params_text + ", " + field_map.ret_conv_name
+                            else:
+                                c_params_text = c_params_text + ", obj->" + camel_to_snake(var_name) + "." + field_map.arg_name
+                out_c.write("\t\t\treturn (*env)->NewObject(env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth" + c_params_text + ");\n")
+                out_c.write("\t\t}\n")
+        out_c.write("\t\tdefault: abort();\n")
+        out_c.write("\t}\n}\n")
+

     def map_trait(struct_name, field_var_lines, trait_fn_lines):
         out_c.write("typedef struct " + struct_name + "_JCalls {\n")
         out_c.write("\tatomic_size_t refcnt;\n")
     def map_trait(struct_name, field_var_lines, trait_fn_lines):
         out_c.write("typedef struct " + struct_name + "_JCalls {\n")
         out_c.write("\tatomic_size_t refcnt;\n")


@@ -366,7 +546,10 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         out_c.write(arg_info.arg_name)
                         out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
 
                         out_c.write(arg_info.arg_name)
                         out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
 

-                if not ret_ty_info.passed_as_ptr:
+                if ret_ty_info.c_ty.endswith("Array"):
+                    assert(ret_ty_info.c_ty == "jbyteArray")
+                    out_c.write("\tjbyteArray jret = (*env)->CallObjectMethod(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth")
+                elif not ret_ty_info.passed_as_ptr:

                     out_c.write("\treturn (*env)->Call" + ret_ty_info.java_ty.title() + "Method(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth")
                 else:
                     out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*env)->CallLongMethod(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth");
                     out_c.write("\treturn (*env)->Call" + ret_ty_info.java_ty.title() + "Method(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth")
                 else:
                     out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*env)->CallLongMethod(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth");


@@ -377,6 +560,10 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     else:
                         out_c.write(", " + arg_info.arg_name)
                 out_c.write(");\n");
                     else:
                         out_c.write(", " + arg_info.arg_name)
                 out_c.write(");\n");

+                if ret_ty_info.c_ty.endswith("Array"):
+                    out_c.write("\t" + ret_ty_info.rust_obj + " ret;\n")
+                    out_c.write("\t(*env)->GetByteArrayRegion(env, jret, 0, " + ret_ty_info.arr_len + ", ret.data);\n")
+                    out_c.write("\treturn ret;\n")

 
                 if ret_ty_info.passed_as_ptr:
                     out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
 
                 if ret_ty_info.passed_as_ptr:
                     out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")


@@ -469,14 +656,6 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 dummy_line = fn_line.group(1) + struct_name + "_call_" + fn_line.group(2) + " " + struct_name + "* arg" + fn_line.group(4) + "\n"
                 map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(arg_conv->" + fn_line.group(2) + ")(arg_conv->this_arg")
 
                 dummy_line = fn_line.group(1) + struct_name + "_call_" + fn_line.group(2) + " " + struct_name + "* arg" + fn_line.group(4) + "\n"
                 map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(arg_conv->" + fn_line.group(2) + ")(arg_conv->this_arg")
 

-    out_java.write("""package org.ldk.impl;
-
-public class bindings {
-       static {
-               System.loadLibrary(\"lightningjni\");
-               init(java.lang.Enum.class);
-       }
-""")

     out_c.write("""#include \"org_ldk_impl_bindings.h\"
 #include <rust_types.h>
 #include <lightning.h>
     out_c.write("""#include \"org_ldk_impl_bindings.h\"
 #include <rust_types.h>
 #include <lightning.h>


@@ -492,33 +671,48 @@ public class bindings {
         out_c.write("""#include <assert.h>
 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 
         out_c.write("""#include <assert.h>
 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
 

+// Running a leak check across all the allocations and frees of the JDK is a mess,
+// so instead we implement our own naive leak checker here, relying on the -wrap
+// linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
+// and free'd in Rust or C across the generated bindings shared library.

 #include <threads.h>
 #include <threads.h>

+#include <execinfo.h>
+#include <unistd.h>

 static mtx_t allocation_mtx;
 
 void __attribute__((constructor)) init_mtx() {
        DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
 }
 
 static mtx_t allocation_mtx;
 
 void __attribute__((constructor)) init_mtx() {
        DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
 }
 

+#define BT_MAX 128

 typedef struct allocation {
        struct allocation* next;
        void* ptr;
        const char* struct_name;
 typedef struct allocation {
        struct allocation* next;
        void* ptr;
        const char* struct_name;

+       void* bt[BT_MAX];
+       int bt_len;

 } allocation;
 static allocation* allocation_ll = NULL;
 
 } allocation;
 static allocation* allocation_ll = NULL;
 

-void* MALLOC(size_t len, const char* struct_name) {
-       void* res = malloc(len);
-       allocation* new_alloc = malloc(sizeof(allocation));
+void* __real_malloc(size_t len);
+void* __real_calloc(size_t nmemb, size_t len);
+static void new_allocation(void* res, const char* struct_name) {
+       allocation* new_alloc = __real_malloc(sizeof(allocation));

        new_alloc->ptr = res;
        new_alloc->struct_name = struct_name;
        new_alloc->ptr = res;
        new_alloc->struct_name = struct_name;

+       new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);

        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        new_alloc->next = allocation_ll;
        allocation_ll = new_alloc;
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        new_alloc->next = allocation_ll;
        allocation_ll = new_alloc;
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);

+}
+static void* MALLOC(size_t len, const char* struct_name) {
+       void* res = __real_malloc(len);
+       new_allocation(res, struct_name);

        return res;
 }
        return res;
 }

-
-void FREE(void* ptr) {
+void __real_free(void* ptr);
+static void alloc_freed(void* ptr) {

        allocation* p = NULL;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        allocation* it = allocation_ll;
        allocation* p = NULL;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        allocation* it = allocation_ll;


@@ -526,32 +720,89 @@ void FREE(void* ptr) {
        if (p) { p->next = it->next; } else { allocation_ll = it->next; }
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(it->ptr == ptr);
        if (p) { p->next = it->next; } else { allocation_ll = it->next; }
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(it->ptr == ptr);

-       free(it);
-       free(ptr);
+       __real_free(it);
+}
+static void FREE(void* ptr) {
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __wrap_malloc(size_t len) {
+       void* res = __real_malloc(len);
+       new_allocation(res, "malloc call");
+       return res;
+}
+void* __wrap_calloc(size_t nmemb, size_t len) {
+       void* res = __real_calloc(nmemb, len);
+       new_allocation(res, "calloc call");
+       return res;
+}
+void __wrap_free(void* ptr) {
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __real_realloc(void* ptr, size_t newlen);
+void* __wrap_realloc(void* ptr, size_t len) {
+       alloc_freed(ptr);
+       void* res = __real_realloc(ptr, len);
+       new_allocation(res, "realloc call");
+       return res;
+}
+void __wrap_reallocarray(void* ptr, size_t new_sz) {
+       // Rust doesn't seem to use reallocarray currently
+       assert(false);

 }
 
 void __attribute__((destructor)) check_leaks() {
 }
 
 void __attribute__((destructor)) check_leaks() {

-       for (allocation* a = allocation_ll; a != NULL; a = a->next) { fprintf(stderr, "%s %p remains\\n", a->struct_name, a->ptr); }
+       for (allocation* a = allocation_ll; a != NULL; a = a->next) {
+               fprintf(stderr, "%s %p remains:\\n", a->struct_name, a->ptr);
+               backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
+               fprintf(stderr, "\\n\\n");
+       }

        DO_ASSERT(allocation_ll == NULL);
 }
 """)
        DO_ASSERT(allocation_ll == NULL);
 }
 """)

+    out_java.write("""package org.ldk.impl;
+import org.ldk.enums.*;

 
 

-    out_java.write("""
-       static native void init(java.lang.Class c);
+public class bindings {
+       public static class VecOrSliceDef {
+               public long dataptr;
+               public long datalen;
+               public long stride;
+               public VecOrSliceDef(long dataptr, long datalen, long stride) {
+                       this.dataptr = dataptr; this.datalen = datalen; this.stride = stride;
+               }
+       }
+       static {
+               System.loadLibrary(\"lightningjni\");
+               init(java.lang.Enum.class, VecOrSliceDef.class);
+       }
+       static native void init(java.lang.Class c, java.lang.Class slicedef);

 
        public static native boolean deref_bool(long ptr);
        public static native long deref_long(long ptr);
        public static native void free_heap_ptr(long ptr);
 
        public static native boolean deref_bool(long ptr);
        public static native long deref_long(long ptr);
        public static native void free_heap_ptr(long ptr);

+       public static native byte[] read_bytes(long ptr, long len);

        public static native byte[] get_u8_slice_bytes(long slice_ptr);
        public static native long bytes_to_u8_vec(byte[] bytes);
        public static native byte[] get_u8_slice_bytes(long slice_ptr);
        public static native long bytes_to_u8_vec(byte[] bytes);

+       public static native long new_txpointer_copy_data(byte[] txdata);

        public static native long vec_slice_len(long vec);
        public static native long vec_slice_len(long vec);

+       public static native long new_empty_slice_vec();

 
 """)
     out_c.write("""
 
 """)
     out_c.write("""

-jmethodID ordinal_meth = NULL;
-JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
+static jmethodID ordinal_meth = NULL;
+static jmethodID slicedef_meth = NULL;
+static jclass slicedef_cls = NULL;
+JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {

        ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
        DO_ASSERT(ordinal_meth != NULL);
        ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
        DO_ASSERT(ordinal_meth != NULL);

+       slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
+       DO_ASSERT(slicedef_meth != NULL);
+       slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
+       DO_ASSERT(slicedef_cls != NULL);

 }
 
 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
 }
 
 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {


@@ -563,6 +814,11 @@ JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jc
 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
        FREE((void*)ptr);
 }
 JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_free_1heap_1ptr (JNIEnv * env, jclass _a, jlong ptr) {
        FREE((void*)ptr);
 }

+JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_read_1bytes (JNIEnv * _env, jclass _b, jlong ptr, jlong len) {
+       jbyteArray ret_arr = (*_env)->NewByteArray(_env, len);
+       (*_env)->SetByteArrayRegion(_env, ret_arr, 0, len, (unsigned char*)ptr);
+       return ret_arr;
+}

 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * _env, jclass _b, jlong slice_ptr) {
        LDKu8slice *slice = (LDKu8slice*)slice_ptr;
        jbyteArray ret_arr = (*_env)->NewByteArray(_env, slice->datalen);
 JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (JNIEnv * _env, jclass _b, jlong slice_ptr) {
        LDKu8slice *slice = (LDKu8slice*)slice_ptr;
        jbyteArray ret_arr = (*_env)->NewByteArray(_env, slice->datalen);


@@ -572,10 +828,18 @@ JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (J
 JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_bytes_1to_1u8_1vec (JNIEnv * _env, jclass _b, jbyteArray bytes) {
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
        vec->datalen = (*_env)->GetArrayLength(_env, bytes);
 JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_bytes_1to_1u8_1vec (JNIEnv * _env, jclass _b, jbyteArray bytes) {
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
        vec->datalen = (*_env)->GetArrayLength(_env, bytes);

-       vec->data = (uint8_t*)malloc(vec->datalen); // May be freed by rust, so don't track allocation
+       vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");

        (*_env)->GetByteArrayRegion (_env, bytes, 0, vec->datalen, vec->data);
        return (long)vec;
 }
        (*_env)->GetByteArrayRegion (_env, bytes, 0, vec->datalen, vec->data);
        return (long)vec;
 }

+JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
+       LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
+       txdata->datalen = (*env)->GetArrayLength(env, bytes);
+       txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
+       txdata->data_is_owned = true;
+       (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
+       return (long)txdata;
+}

 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");


@@ -585,6 +849,17 @@ JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
        return (long)vec->datalen;
 }
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
        return (long)vec->datalen;
 }

+JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1empty_1slice_1vec (JNIEnv * _env, jclass _b) {
+        // Check sizes of a few Vec types are all consistent as we're meant to be generic across types
+       _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_SignatureZ), "Vec<*> needs to be mapped identically");
+       _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_MessageSendEventZ), "Vec<*> needs to be mapped identically");
+       _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_EventZ), "Vec<*> needs to be mapped identically");
+       _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKCVec_C2Tuple_usizeTransactionZZ), "Vec<*> needs to be mapped identically");
+       LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "Empty LDKCVec");
+       vec->data = NULL;
+       vec->datalen = 0;
+       return (long)vec;
+}

 
 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");
 
 // We assume that CVec_u8Z and u8slice are the same size and layout (and thus pointers to the two can be mixed)
 _Static_assert(sizeof(LDKCVec_u8Z) == sizeof(LDKu8slice), "Vec<u8> and [u8] need to have been mapped identically");


@@ -609,6 +884,7 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
     line_indicates_result_regex = re.compile("^   bool result_ok;$")
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
     line_indicates_result_regex = re.compile("^   bool result_ok;$")

+    line_indicates_vec_regex = re.compile("^   ([A-Za-z_0-9]*) \*data;$")

     line_indicates_opaque_regex = re.compile("^   bool is_owned;$")
     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
     assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))
     line_indicates_opaque_regex = re.compile("^   bool is_owned;$")
     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
     assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))


@@ -623,9 +899,9 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
     assert(struct_alias_regex.match("typedef LDKCResultTempl_bool__PeerHandleError LDKCResult_boolPeerHandleErrorZ;"))
 
     result_templ_structs = set()
     assert(struct_alias_regex.match("typedef LDKCResultTempl_bool__PeerHandleError LDKCResult_boolPeerHandleErrorZ;"))
 
     result_templ_structs = set()

+    union_enum_items = {}

     for line in in_h:
         if in_block_comment:
     for line in in_h:
         if in_block_comment:

-            #out_java.write("\t" + line)

             if line.endswith("*/\n"):
                 in_block_comment = False
         elif cur_block_obj is not None:
             if line.endswith("*/\n"):
                 in_block_comment = False
         elif cur_block_obj is not None:


@@ -633,12 +909,14 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
             if line.startswith("} "):
                 field_lines = []
                 struct_name = None
             if line.startswith("} "):
                 field_lines = []
                 struct_name = None

+                vec_ty = None

                 obj_lines = cur_block_obj.split("\n")
                 is_opaque = False
                 is_result = False
                 is_unitary_enum = False
                 is_union_enum = False
                 is_union = False
                 obj_lines = cur_block_obj.split("\n")
                 is_opaque = False
                 is_result = False
                 is_unitary_enum = False
                 is_union_enum = False
                 is_union = False

+                is_tuple = False

                 trait_fn_lines = []
                 field_var_lines = []
 
                 trait_fn_lines = []
                 field_var_lines = []
 


@@ -663,6 +941,11 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                             is_opaque = True
                         elif line_indicates_result_regex.match(struct_line):
                             is_result = True
                             is_opaque = True
                         elif line_indicates_result_regex.match(struct_line):
                             is_result = True

+                        vec_ty_match = line_indicates_vec_regex.match(struct_line)
+                        if vec_ty_match is not None and struct_name.startswith("LDKCVecTempl_"):
+                            vec_ty = vec_ty_match.group(1)
+                        elif struct_name.startswith("LDKC2TupleTempl_") or struct_name.startswith("LDKC3TupleTempl_"):
+                            is_tuple = True

                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)
                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)


@@ -672,61 +955,98 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)

-                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union))
-                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union))
-                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union))
-                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union))
-                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque))
+                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union or is_result or vec_ty is not None))
+                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union or is_result or vec_ty is not None))
+                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union or is_result or vec_ty is not None))
+                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union or is_result or vec_ty is not None))
+                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_result or vec_ty is not None))
+                assert(not is_result or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or vec_ty is not None))
+                assert(vec_ty is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or is_result))
+

                 if is_opaque:
                     opaque_structs.add(struct_name)
                 if is_opaque:
                     opaque_structs.add(struct_name)

-                    out_java.write("\tpublic static native long " + struct_name + "_optional_none();\n")
-                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1optional_1none (JNIEnv * env, jclass _a) {\n")
-                    out_c.write("\t" + struct_name + " *ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
-                    out_c.write("\tret->inner = NULL;\n")
-                    out_c.write("\treturn (long)ret;\n")
-                    out_c.write("}\n")

                 elif is_result:
                     result_templ_structs.add(struct_name)
                 elif is_result:
                     result_templ_structs.add(struct_name)

-                elif is_unitary_enum:
-                    unitary_enums.add(struct_name)
-                    out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
-                    out_c.write("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
-                    ord_v = 0
-                    for idx, struct_line in enumerate(field_lines):
-                        if idx == 0:
-                            out_java.write("\tpublic enum " + struct_name + " {\n")
-                        elif idx == len(field_lines) - 3:
-                            assert(struct_line.endswith("_Sentinel,"))
-                        elif idx == len(field_lines) - 2:
-                            out_java.write("\t}\n")
-                        elif idx == len(field_lines) - 1:
-                            assert(struct_line == "")
-                        else:
-                            out_java.write("\t" + struct_line + "\n")
-                            out_c.write("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
-                            ord_v = ord_v + 1
-                    out_c.write("\t}\n")
-                    out_c.write("\tabort();\n")
+                elif is_tuple:
+                    out_java.write("\tpublic static native long " + struct_name + "_new(")
+                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *_env, jclass _b")
+                    for idx, line in enumerate(field_lines):
+                        if idx != 0 and idx < len(field_lines) - 2:
+                            ty_info = java_c_types(line.strip(';'), None)
+                            if idx != 1:
+                                out_java.write(", ")
+                            e = chr(ord('a') + idx - 1)
+                            out_java.write(ty_info.java_ty + " " + e)
+                            out_c.write(", " + ty_info.c_ty + " " + e)
+                    out_java.write(");\n")
+                    out_c.write(") {\n")
+                    out_c.write("\t" + struct_name + "* ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+                    for idx, line in enumerate(field_lines):
+                        if idx != 0 and idx < len(field_lines) - 2:
+                            ty_info = map_type(line.strip(';'), False, None, False)
+                            e = chr(ord('a') + idx - 1)
+                            if ty_info.arg_conv is not None:
+                                out_c.write("\t" + ty_info.arg_conv.replace("\n", "\n\t"))
+                                out_c.write("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
+                            else:
+                                out_c.write("\tret->" + e + " = " + e + ";\n")
+                    out_c.write("\treturn (long)ret;\n")
+                    out_c.write("}\n")
+                elif vec_ty is not None:
+                    if vec_ty in opaque_structs:
+                        out_java.write("\tpublic static native long[] " + struct_name + "_arr_info(long vec_ptr);\n")
+                        out_c.write("JNIEXPORT jlongArray JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    else:
+                        out_java.write("\tpublic static native VecOrSliceDef " + struct_name + "_arr_info(long vec_ptr);\n")
+                        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    out_c.write("\t" + struct_name + " *vec = (" + struct_name + "*)ptr;\n")
+                    if vec_ty in opaque_structs:
+                        out_c.write("\tjlongArray ret = (*env)->NewLongArray(env, vec->datalen);\n")
+                        out_c.write("\tjlong *ret_elems = (*env)->GetPrimitiveArrayCritical(env, ret, NULL);\n")
+                        out_c.write("\tfor (size_t i = 0; i < vec->datalen; i++) {\n")
+                        out_c.write("\t\tDO_ASSERT((((long)vec->data[i].inner) & 1) == 0);\n")
+                        out_c.write("\t\tret_elems[i] = (long)vec->data[i].inner | (vec->data[i].is_owned ? 1 : 0);\n")
+                        out_c.write("\t}\n")
+                        out_c.write("\t(*env)->ReleasePrimitiveArrayCritical(env, ret, ret_elems, 0);\n")
+                        out_c.write("\treturn ret;\n")
+                    else:
+                        out_c.write("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")

                     out_c.write("}\n")
 
                     out_c.write("}\n")
 

-                    ord_v = 0
-                    out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
-                    out_c.write("\t// TODO: This is pretty inefficient, we really need to cache the field IDs and class\n")
-                    out_c.write("\tjclass enum_class = (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + ";\");\n")
-                    out_c.write("\tDO_ASSERT(enum_class != NULL);\n")
-                    out_c.write("\tswitch (val) {\n")
-                    for idx, struct_line in enumerate(field_lines):
-                        if idx > 0 and idx < len(field_lines) - 3:
-                            variant = struct_line.strip().strip(",")
-                            out_c.write("\t\tcase " + variant + ": {\n")
-                            out_c.write("\t\t\tjfieldID field = (*env)->GetStaticFieldID(env, enum_class, \"" + variant + "\", \"Lorg/ldk/impl/bindings$" + struct_name + ";\");\n")
-                            out_c.write("\t\t\tDO_ASSERT(field != NULL);\n")
-                            out_c.write("\t\t\treturn (*env)->GetStaticObjectField(env, enum_class, field);\n")
-                            out_c.write("\t\t}\n")
-                            ord_v = ord_v + 1
-                    out_c.write("\t\tdefault: abort();\n")
+                    ty_info = map_type(vec_ty + " arr_elem", False, None, False)
+                    out_java.write("\tpublic static native long " + struct_name + "_new(" + ty_info.java_ty + "[] elems);\n")
+                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *env, jclass _b, j" + ty_info.java_ty + "Array elems){\n")
+                    out_c.write("\t" + struct_name + " *ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+                    out_c.write("\tret->datalen = (*env)->GetArrayLength(env, elems);\n")
+                    out_c.write("\tif (ret->datalen == 0) {\n")
+                    out_c.write("\t\tret->data = NULL;\n")
+                    out_c.write("\t} else {\n")
+                    out_c.write("\t\tret->data = MALLOC(sizeof(" + vec_ty + ") * ret->datalen, \"" + struct_name + " Data\");\n")
+                    assert len(ty_info.java_fn_ty_arg) == 1 # ie we're a primitive of some form
+                    out_c.write("\t\t" + ty_info.c_ty + " *java_elems = (*env)->GetPrimitiveArrayCritical(env, elems, NULL);\n")
+                    out_c.write("\t\tfor (size_t i = 0; i < ret->datalen; i++) {\n")
+                    if ty_info.arg_conv is not None:
+                        out_c.write("\t\t\t" + ty_info.c_ty + " arr_elem = java_elems[i];\n")
+                        out_c.write("\t\t\t" + ty_info.arg_conv.replace("\n", "\n\t\t\t") + "\n")
+                        out_c.write("\t\t\tret->data[i] = " + ty_info.arg_conv_name + ";\n")
+                    else:
+                        out_c.write("\t\t\tret->data[i] = java_elems[i];\n")
+                    out_c.write("\t\t}\n")
+                    out_c.write("\t\t(*env)->ReleasePrimitiveArrayCritical(env, elems, java_elems, 0);\n")

                     out_c.write("\t}\n")
                     out_c.write("\t}\n")

-                    out_c.write("}\n\n")
+                    out_c.write("\treturn (long)ret;\n")
+                    out_c.write("}\n")
+                elif is_union_enum:
+                    assert(struct_name.endswith("_Tag"))
+                    struct_name = struct_name[:-4]
+                    union_enum_items[struct_name] = {"field_lines": field_lines}
+                elif struct_name.endswith("_Body") and struct_name.split("_")[0] in union_enum_items:
+                    enum_var_name = struct_name.split("_")
+                    union_enum_items[enum_var_name[0]][enum_var_name[1]] = field_lines
+                elif struct_name in union_enum_items:
+                    map_complex_enum(struct_name, union_enum_items[struct_name])
+                elif is_unitary_enum:
+                    map_unitary_enum(struct_name, field_lines)

                 elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)
                 elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)