Macro-ize assert to handle side-effects, fix JavaVM access, util fns
[ldk-java] / genbindings.py
index ab68ec81b00f6867410b8854c72d6957b8a8093d..a5e9ec41e38c62742b561606341f301aa0bd3b0c 100755 (executable)
@@ -46,6 +46,7 @@ class ConvInfo:
 with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[3], "w") as out_c:
     opaque_structs = set()
     trait_structs = set()
+    unitary_enums = set()
 
     var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
     var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
@@ -86,11 +87,14 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             c_ty = "jint"
             fn_ty_arg = "I"
             fn_arg = fn_arg[8:].strip()
-        elif fn_arg.startswith("uint64_t"):
+        elif fn_arg.startswith("uint64_t") or fn_arg.startswith("uintptr_t"):
             java_ty = "long"
             c_ty = "jlong"
             fn_ty_arg = "J"
-            fn_arg = fn_arg[8:].strip()
+            if fn_arg.startswith("uint64_t"):
+                fn_arg = fn_arg[8:].strip()
+            else:
+                fn_arg = fn_arg[9:].strip()
         elif is_const and fn_arg.startswith("char *"):
             java_ty = "String"
             c_ty = "const char*"
@@ -98,18 +102,27 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             fn_arg = fn_arg[6:].strip()
         else:
             ma = var_ty_regex.match(fn_arg)
-            java_ty = "long"
-            c_ty = "jlong"
-            fn_ty_arg = "J"
-            fn_arg = ma.group(2).strip()
-            rust_obj = ma.group(1).strip()
-            take_by_ptr = True
+            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_arg = ma.group(2).strip()
+                rust_obj = ma.group(1).strip()
+                take_by_ptr = True
+            else:
+                java_ty = "long"
+                c_ty = "jlong"
+                fn_ty_arg = "J"
+                fn_arg = ma.group(2).strip()
+                rust_obj = ma.group(1).strip()
+                take_by_ptr = True
 
         if fn_arg.startswith(" *") or fn_arg.startswith("*"):
             fn_arg = fn_arg.replace("*", "").strip()
             is_ptr = True
             c_ty = "jlong"
             java_ty = "long"
+            fn_ty_arg = "J"
 
         var_is_arr = var_is_arr_regex.match(fn_arg)
         if var_is_arr is not None or ret_arr_len is not None:
@@ -153,32 +166,42 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             if ty_info.rust_obj is not None:
                 assert(ty_info.passed_as_ptr)
                 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,
+                            arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
+                            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")
                     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 = base_conv + "\n" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_arg);"
+                            base_conv = base_conv + "\nif (" + ty_info.var_name + "_conv.free == " + ty_info.rust_obj + "_JCalls_free) {\n"
+                            base_conv = base_conv + "\t// If this_arg is a JCalls struct, then we need to increment the refcnt in it.\n"
+                            base_conv = base_conv + "\t" + ty_info.rust_obj + "_JCalls_clone(" + ty_info.var_name + "_conv.this_arg);\n}"
                         else:
                             base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
                         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 = None, ret_conv_name = None)
-                    base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";
+                            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
+                        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._underlying_ref = false;",
+                            arg_conv = base_conv + "\n" + ty_info.var_name + "_conv.is_owned = true;",
                             arg_conv_name = ty_info.var_name + "_conv",
-                            ret_conv = None, ret_conv_name = None)
+                            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 = None, ret_conv_name = None)
+                        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 = 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",
-                        ret_conv = None, ret_conv_name = None)
+                        ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
             elif ty_info.is_ptr:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = None, arg_conv_name = ty_info.var_name, ret_conv = None, ret_conv_name = None)
@@ -205,13 +228,18 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             # We don't have a parameter name, and don't want one (cause we're returning)
             if ty_info.rust_obj is not None:
                 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,
+                            arg_conv = ty_info.rust_obj + " ret = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
+                            arg_conv_name = "ret",
+                            ret_conv = ("jclass ret = " + ty_info.rust_obj + "_to_java(_env, ", ");"), ret_conv_name = "ret")
                     if ty_info.rust_obj in opaque_structs:
                         # If we're returning a newly-allocated struct, we don't want Rust to ever
                         # free, instead relying on the Java GC to lose the ref. We undo this in
                         # 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 = ", ";\nassert(!ret->_underlying_ref);\nret->_underlying_ref = true;"),
+                            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",
                             arg_conv = None, arg_conv_name = None)
                     else:
@@ -227,8 +255,8 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
 
-    def map_fn(re_match, ret_arr_len):
-        out_java.write("\t/// " + line)
+    def map_fn(line, re_match, ret_arr_len, c_call_string):
+        out_java.write("\t// " + line)
         out_java.write("\tpublic static native ")
         out_c.write("JNIEXPORT ")
 
@@ -264,11 +292,16 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         else:
             out_c.write("\treturn ");
 
-        out_c.write(re_match.group(2) + "(")
+        if c_call_string is None:
+            out_c.write(re_match.group(2) + "(")
+        else:
+            out_c.write(c_call_string)
         for idx, info in enumerate(arg_names):
             if info.arg_conv_name is not None:
                 if idx != 0:
                     out_c.write(", ")
+                elif c_call_string is not None:
+                    continue
                 out_c.write(info.arg_conv_name)
         out_c.write(")")
         if ret_info.ret_conv is not None:
@@ -281,7 +314,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
     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")
-        out_c.write("\tJNIEnv *env;\n")
+        out_c.write("\tJavaVM *vm;\n")
         out_c.write("\tjobject o;\n")
         for var_line in field_var_lines:
             if var_line.group(1) in trait_structs:
@@ -324,17 +357,19 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 out_java.write(");\n")
                 out_c.write(") {\n")
                 out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+                out_c.write("\tJNIEnv *env;\n")
+                out_c.write("\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
 
                 for arg_info in arg_names:
                     if arg_info.ret_conv is not None:
-                        out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t').replace("_env", "j_calls->env"));
+                        out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t').replace("_env", "env"));
                         out_c.write(arg_info.arg_name)
-                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "j_calls->env") + "\n")
+                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
 
                 if not ret_ty_info.passed_as_ptr:
-                    out_c.write("\treturn (*j_calls->env)->Call" + ret_ty_info.java_ty.title() + "Method(j_calls->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() + "*)(*j_calls->env)->CallLongMethod(j_calls->env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth");
+                    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");
 
                 for arg_info in arg_names:
                     if arg_info.ret_conv is not None:
@@ -352,7 +387,9 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 out_c.write("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
                 out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
                 out_c.write("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
-                out_c.write("\t\t(*j_calls->env)->DeleteGlobalRef(j_calls->env, j_calls->o);\n")
+                out_c.write("\t\tJNIEnv *env;\n")
+                out_c.write("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
+                out_c.write("\t\t(*env)->DeleteGlobalRef(env, j_calls->o);\n")
                 out_c.write("\t\tFREE(j_calls);\n")
                 out_c.write("\t}\n}\n")
 
@@ -378,15 +415,15 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write(") {\n")
 
         out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
-        out_c.write("\tassert(c != NULL);\n")
+        out_c.write("\tDO_ASSERT(c != NULL);\n")
         out_c.write("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
         out_c.write("\tatomic_init(&calls->refcnt, 1);\n")
-        out_c.write("\tcalls->env = env;\n")
+        out_c.write("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")
         out_c.write("\tcalls->o = (*env)->NewGlobalRef(env, o);\n")
         for (fn_line, java_meth_descr) in zip(trait_fn_lines, java_meths):
             if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
                 out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")
-                out_c.write("\tassert(calls->" + fn_line.group(2) + "_meth != NULL);\n")
+                out_c.write("\tDO_ASSERT(calls->" + fn_line.group(2) + "_meth != NULL);\n")
         out_c.write("\n\t" + struct_name + " ret = {\n")
         out_c.write("\t\t.this_arg = (void*) calls,\n")
         for fn_line in trait_fn_lines:
@@ -420,63 +457,136 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write("\treturn (long)res_ptr;\n")
         out_c.write("}\n")
 
+        out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
+        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
+        out_c.write("\treturn ((" + struct_name + "_JCalls*)val)->o;\n")
+        out_c.write("}\n")
 
+        for fn_line in trait_fn_lines:
+            # For now, just disable enabling the _call_log - we don't know how to inverse-map String
+            is_log = fn_line.group(2) == "log" and struct_name == "LDKLogger"
+            if fn_line.group(2) != "free" and fn_line.group(2) != "clone" and fn_line.group(2) != "eq" and not is_log:
+                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\"\n")
-    out_c.write("#include <rust_types.h>\n")
-    out_c.write("#include <lightning.h>\n")
-    out_c.write("#include <assert.h>\n")
-    out_c.write("#include <string.h>\n")
-    out_c.write("#include <stdatomic.h>\n\n")
+    out_c.write("""#include \"org_ldk_impl_bindings.h\"
+#include <rust_types.h>
+#include <lightning.h>
+#include <string.h>
+#include <stdatomic.h>
+""")
+
     if sys.argv[4] == "false":
         out_c.write("#define MALLOC(a, _) malloc(a)\n")
-        out_c.write("#define FREE free\n\n")
+        out_c.write("#define FREE free\n")
+        out_c.write("#define DO_ASSERT(a) (void)(a)\n")
     else:
-        out_c.write("#include <threads.h>\n")
-        out_c.write("static mtx_t allocation_mtx;\n\n")
-        out_c.write("void __attribute__((constructor)) init_mtx() {\n")
-        out_c.write("\tassert(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);\n")
-        out_c.write("}\n\n")
-        out_c.write("typedef struct allocation {\n")
-        out_c.write("\tstruct allocation* next;\n")
-        out_c.write("\tvoid* ptr;\n")
-        out_c.write("\tconst char* struct_name;\n")
-        out_c.write("} allocation;\n")
-        out_c.write("static allocation* allocation_ll = NULL;\n\n")
-        out_c.write("void* MALLOC(size_t len, const char* struct_name) {\n")
-        out_c.write("\tvoid* res = malloc(len);\n")
-        out_c.write("\tallocation* new_alloc = malloc(sizeof(allocation));\n")
-        out_c.write("\tnew_alloc->ptr = res;\n")
-        out_c.write("\tnew_alloc->struct_name = struct_name;\n")
-        out_c.write("\tassert(mtx_lock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tnew_alloc->next = allocation_ll;\n")
-        out_c.write("\tallocation_ll = new_alloc;\n")
-        out_c.write("\tassert(mtx_unlock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\treturn res;\n")
-        out_c.write("}\n\n")
-        out_c.write("void FREE(void* ptr) {\n")
-        out_c.write("\tallocation* p = NULL;\n")
-        out_c.write("\tassert(mtx_lock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tallocation* it = allocation_ll;\n")
-        out_c.write("\twhile (it->ptr != ptr) { p = it; it = it->next; }\n")
-        out_c.write("\tif (p) { p->next = it->next; } else { allocation_ll = it->next; }\n")
-        out_c.write("\tassert(mtx_unlock(&allocation_mtx) == thrd_success);\n")
-        out_c.write("\tassert(it->ptr == ptr);\n")
-        out_c.write("\tfree(it);\n")
-        out_c.write("\tfree(ptr);\n")
-        out_c.write("}\n\n")
-        out_c.write("void __attribute__((destructor)) check_leaks() {\n")
-        out_c.write("\tfor (allocation* a = allocation_ll; a != NULL; a = a->next) { fprintf(stderr, \"%s %p remains\\n\", a->struct_name, a->ptr); }\n")
-        out_c.write("\tassert(allocation_ll == NULL);\n")
-        out_c.write("}\n\n")
+        out_c.write("""#include <assert.h>
+#define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
+
+#include <threads.h>
+static mtx_t allocation_mtx;
+
+void __attribute__((constructor)) init_mtx() {
+       DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
+}
+
+typedef struct allocation {
+       struct allocation* next;
+       void* ptr;
+       const char* struct_name;
+} 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));
+       new_alloc->ptr = res;
+       new_alloc->struct_name = struct_name;
+       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);
+       return res;
+}
+
+void FREE(void* ptr) {
+       allocation* p = NULL;
+       DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
+       allocation* it = allocation_ll;
+       while (it->ptr != ptr) { p = it; it = it->next; }
+       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);
+}
+
+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); }
+       DO_ASSERT(allocation_ll == NULL);
+}
+""")
+
+    out_java.write("""
+       static native void init(java.lang.Class c);
+
+       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[] get_u8_slice_bytes(long slice_ptr);
+       public static native long bytes_to_u8_vec(byte[] bytes);
+       public static native long u8_vec_len(long vec);
+
+""")
+    out_c.write("""
+jmethodID ordinal_meth = NULL;
+JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class) {
+       ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
+       DO_ASSERT(ordinal_meth != NULL);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
+       return *((bool*)ptr);
+}
+JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_deref_1long (JNIEnv * env, jclass _a, jlong ptr) {
+       return *((long*)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_get_1u8_1slice_1bytes (JNIEnv * _env, jclass _b, jlong slice_ptr) {
+       LDKu8slice *slice = (LDKu8slice*)slice_ptr;
+       jbyteArray ret_arr = (*_env)->NewByteArray(_env, slice->datalen);
+       (*_env)->SetByteArrayRegion(_env, ret_arr, 0, slice->datalen, slice->data);
+       return ret_arr;
+}
+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
+       (*_env)->GetByteArrayRegion (_env, bytes, 0, vec->datalen, vec->data);
+       return (long)vec;
+}
+JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_u8_1vec_1len (JNIEnv * env, jclass _a, jlong ptr) {
+       LDKCVec_u8Z *vec = (LDKCVec_u8Z*)ptr;
+       return (long)vec->datalen;
+}
+
+// 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");
+_Static_assert(offsetof(LDKCVec_u8Z, data) == offsetof(LDKu8slice, data), "Vec<u8> and [u8] need to have been mapped identically");
+_Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen), "Vec<u8> and [u8] need to have been mapped identically");
+
+""")
 
     # XXX: Temporarily write out a manual SecretKey_new() for testing, we should auto-gen this kind of thing
     out_java.write("\tpublic static native long LDKSecretKey_new();\n\n") # TODO: rm me
@@ -486,42 +596,48 @@ public class bindings {
     out_c.write("}\n") # TODO: rm me
 
     in_block_comment = False
-    in_block_enum = False
-    cur_block_struct = None
-    in_block_union = False
+    cur_block_obj = None
 
     fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
     fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
     reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
-    line_indicates_opaque_regex = re.compile("^   bool _underlying_ref;$")
+    line_indicates_result_regex = re.compile("^   bool result_ok;$")
+    line_indicates_opaque_regex = re.compile("^   bool is_owned;$")
     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
     assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))
     assert(line_indicates_trait_regex.match("   LDKCVec_MessageSendEventZ (*get_and_clear_pending_msg_events)(const void *this_arg);"))
     assert(line_indicates_trait_regex.match("   void *(*clone)(const void *this_arg);"))
     line_field_var_regex = re.compile("^   ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
     assert(line_field_var_regex.match("   LDKMessageSendEventsProvider MessageSendEventsProvider;"))
-    struct_name_regex = re.compile("^typedef (struct|enum) (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
+    struct_name_regex = re.compile("^typedef (struct|enum|union) (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
     assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
     assert(struct_name_regex.match("typedef enum LDKNetwork {"))
+    struct_alias_regex = re.compile("^typedef (LDK[A-Za-z_0-9]*) (LDK[A-Za-z_0-9]*);$")
+    assert(struct_alias_regex.match("typedef LDKCResultTempl_bool__PeerHandleError LDKCResult_boolPeerHandleErrorZ;"))
 
+    result_templ_structs = set()
     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_struct is not None:
-            cur_block_struct  = cur_block_struct + line
+        elif cur_block_obj is not None:
+            cur_block_obj  = cur_block_obj + line
             if line.startswith("} "):
                 field_lines = []
                 struct_name = None
-                struct_lines = cur_block_struct.split("\n")
+                obj_lines = cur_block_obj.split("\n")
                 is_opaque = False
+                is_result = False
+                is_unitary_enum = False
+                is_union_enum = False
+                is_union = False
                 trait_fn_lines = []
                 field_var_lines = []
 
-                for idx, struct_line in enumerate(struct_lines):
+                for idx, struct_line in enumerate(obj_lines):
                     if struct_line.strip().startswith("/*"):
                         in_block_comment = True
                     if in_block_comment:
@@ -530,9 +646,18 @@ public class bindings {
                     else:
                         struct_name_match = struct_name_regex.match(struct_line)
                         if struct_name_match is not None:
-                            struct_name = struct_name_match.group(2)
+                            struct_name = struct_name_match.group(3)
+                            if struct_name_match.group(1) == "enum":
+                                if not struct_name.endswith("_Tag"):
+                                    is_unitary_enum = True
+                                else:
+                                    is_union_enum = True
+                            elif struct_name_match.group(1) == "union":
+                                is_union = True
                         if line_indicates_opaque_regex.match(struct_line):
                             is_opaque = True
+                        elif line_indicates_result_regex.match(struct_line):
+                            is_result = 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)
@@ -542,20 +667,59 @@ public class bindings {
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)
-                assert(len(trait_fn_lines) == 0 or not is_opaque)
+                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))
                 if is_opaque:
                     opaque_structs.add(struct_name)
-                if len(trait_fn_lines) > 0:
+                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")
+                    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")
+                    out_c.write("\t}\n")
+                    out_c.write("}\n\n")
+                elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)
-                    #out_java.write("/* " + "\n".join(field_lines) + "*/\n")
-                cur_block_struct = None
-        elif in_block_union:
-            if line.startswith("} "):
-                in_block_union = False
-        elif in_block_enum:
-            if line.startswith("} "):
-                in_block_enum = False
+                cur_block_obj = None
         else:
             fn_ptr = fn_ptr_regex.match(line)
             fn_ret_arr = fn_ret_arr_regex.match(line)
@@ -569,19 +733,32 @@ public class bindings {
                 if not line.endswith("*/\n"):
                     in_block_comment = True
             elif line.startswith("typedef enum "):
-                in_block_enum = True
+                cur_block_obj = line
             elif line.startswith("typedef struct "):
-                cur_block_struct = line
+                cur_block_obj = line
             elif line.startswith("typedef union "):
-                in_block_union = True
+                cur_block_obj = line
             elif line.startswith("typedef "):
+                alias_match =  struct_alias_regex.match(line)
+                if alias_match.group(1) in result_templ_structs:
+                    out_java.write("\tpublic static native boolean " + alias_match.group(2) + "_result_ok(long arg);\n")
+                    out_java.write("\tpublic static native long " + alias_match.group(2) + "_get_inner(long arg);\n")
+                    out_c.write("JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1result_1ok (JNIEnv * env, jclass _a, jlong arg) {\n")
+                    out_c.write("\treturn ((" + alias_match.group(2) + "*)arg)->result_ok;\n")
+                    out_c.write("}\n")
+                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1inner (JNIEnv * env, jclass _a, jlong arg) {\n")
+                    out_c.write("\tif (((" + alias_match.group(2) + "*)arg)->result_ok) {\n")
+                    out_c.write("\t\treturn (long)((" + alias_match.group(2) + "*)arg)->contents.result;\n")
+                    out_c.write("\t} else {\n")
+                    out_c.write("\t\treturn (long)((" + alias_match.group(2) + "*)arg)->contents.err;\n")
+                    out_c.write("\t}\n}\n")
                 pass
             elif fn_ptr is not None:
-                map_fn(fn_ptr, None)
+                map_fn(line, fn_ptr, None, None)
             elif fn_ret_arr is not None:
-                map_fn(fn_ret_arr, fn_ret_arr.group(4))
+                map_fn(line, fn_ret_arr, fn_ret_arr.group(4), None)
             elif reg_fn is not None:
-                map_fn(reg_fn, None)
+                map_fn(line, reg_fn, None, None)
             elif const_val_regex is not None:
                 # TODO Map const variables
                 pass