Move trait mapping to an fn
[ldk-java] / genbindings.py
index 66bc62537d3fd41e06cbf63e083d57340b500cd5..ab68ec81b00f6867410b8854c72d6957b8a8093d 100755 (executable)
@@ -1,8 +1,9 @@
 #!/usr/bin/env python3
 import sys, re
 
-if len(sys.argv) != 4:
-    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/output.c")
+if len(sys.argv) != 5:
+    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /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)
 
 class TypeInfo:
@@ -44,6 +45,7 @@ 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()
 
     var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
     var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
@@ -112,12 +114,12 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         var_is_arr = var_is_arr_regex.match(fn_arg)
         if var_is_arr is not None or ret_arr_len is not None:
             assert(not take_by_ptr)
-            #assert(not passed_as_ptr)
+            assert(not is_ptr)
             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, passed_as_ptr=is_ptr,
-                    is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2))
+                return TypeInfo(rust_obj=None, 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)
 
@@ -151,12 +153,23 @@ 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:
-                    base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";\nfree((void*)" + ty_info.var_name + ");";
+                    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);"
+                        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 + ");";
                     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_name = ty_info.var_name + "_conv",
                             ret_conv = None, ret_conv_name = None)
+
                     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)
@@ -169,6 +182,10 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
             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)
+            elif ty_info.java_ty == "String":
+                return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                    arg_conv = None, arg_conv_name = None,
+                    ret_conv = ("jstring " + ty_info.var_name + "_conv = (*_env)->NewStringUTF(_env, ", ");"), ret_conv_name = ty_info.var_name + "_conv")
             else:
                 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)
@@ -177,7 +194,7 @@ 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(not is_free or ty_info.rust_obj not in opaque_structs);
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nfree((void*)arg);",
+                    arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
                     arg_conv_name = "arg_conv",
                     ret_conv = None, ret_conv_name = None)
             else:
@@ -194,12 +211,12 @@ 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,
-                            ret_conv = (ty_info.rust_obj + "* ret = malloc(sizeof(" + 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 = ", ";\nassert(!ret->_underlying_ref);\nret->_underlying_ref = true;"),
                             ret_conv_name = "(long)ret",
                             arg_conv = None, arg_conv_name = None)
                     else:
                         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 + "));\n*ret = ", ";"),
+                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
                             ret_conv_name = "(long)ret",
                             arg_conv = None, arg_conv_name = None)
                 else:
@@ -261,6 +278,150 @@ 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")
 
+    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("\tjobject o;\n")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
+        for fn_line in trait_fn_lines:
+            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
+        out_c.write("} " + struct_name + "_JCalls;\n")
+
+        out_java.write("\tpublic interface " + struct_name + " {\n")
+        java_meths = []
+        for fn_line in trait_fn_lines:
+            java_meth_descr = "("
+            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                ret_ty_info = java_c_types(fn_line.group(1), None)
+
+                out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")
+                is_const = fn_line.group(3) is not None
+                out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
+                if is_const:
+                    out_c.write("const void* this_arg")
+                else:
+                    out_c.write("void* this_arg")
+
+                arg_names = []
+                for idx, arg in enumerate(fn_line.group(4).split(',')):
+                    if arg == "":
+                        continue
+                    if idx >= 2:
+                        out_java.write(", ")
+                    out_c.write(", ")
+                    arg_conv_info = map_type(arg, True, None, False)
+                    out_c.write(arg.strip())
+                    out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
+                    arg_names.append(arg_conv_info)
+                    java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
+                java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
+                java_meths.append(java_meth_descr)
+
+                out_java.write(");\n")
+                out_c.write(") {\n")
+                out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\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(arg_info.arg_name)
+                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "j_calls->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")
+                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");
+
+                for arg_info in arg_names:
+                    if arg_info.ret_conv is not None:
+                        out_c.write(", " + arg_info.ret_conv_name)
+                    else:
+                        out_c.write(", " + arg_info.arg_name)
+                out_c.write(");\n");
+
+                if ret_ty_info.passed_as_ptr:
+                    out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
+                    out_c.write("\tFREE(ret);\n")
+                    out_c.write("\treturn res;\n")
+                out_c.write("}\n")
+            elif fn_line.group(2) == "free":
+                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\tFREE(j_calls);\n")
+                out_c.write("\t}\n}\n")
+
+        # Write out a clone function whether we need one or not, as we use them in moving to rust
+        out_c.write("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
+        out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+        out_c.write("\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
+        out_c.write("\treturn (void*) this_arg;\n")
+        out_c.write("}\n")
+
+        out_java.write("\t}\n")
+
+        out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
+        out_c.write("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
+                out_c.write(", jobject " + var_line.group(2))
+        out_java.write(");\n")
+        out_c.write(") {\n")
+
+        out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
+        out_c.write("\tassert(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("\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("\n\t" + struct_name + " ret = {\n")
+        out_c.write("\t\t.this_arg = (void*) calls,\n")
+        for fn_line in trait_fn_lines:
+            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                out_c.write("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
+            elif fn_line.group(2) == "free":
+                out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
+            else:
+                out_c.write("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write("\t\t." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
+        out_c.write("\t};\n")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
+        out_c.write("\treturn ret;\n")
+        out_c.write("}\n")
+
+        out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write(", jobject " + var_line.group(2))
+        out_c.write(") {\n")
+        out_c.write("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+        out_c.write("\t*res_ptr = " + struct_name + "_init(env, _a, o")
+        for var_line in field_var_lines:
+            if var_line.group(1) in trait_structs:
+                out_c.write(", " + var_line.group(2))
+        out_c.write(");\n")
+        out_c.write("\treturn (long)res_ptr;\n")
+        out_c.write("}\n")
+
+
+
     out_java.write("""package org.ldk.impl;
 
 public class bindings {
@@ -272,8 +433,57 @@ public class bindings {
     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\n")
-    out_c.write("#include <string.h>\n\n")
+    out_c.write("#include <assert.h>\n")
+    out_c.write("#include <string.h>\n")
+    out_c.write("#include <stdatomic.h>\n\n")
+    if sys.argv[4] == "false":
+        out_c.write("#define MALLOC(a, _) malloc(a)\n")
+        out_c.write("#define FREE free\n\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")
+
+    # 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
+    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_LDKSecretKey_1new(JNIEnv * _env, jclass _b) {\n") # TODO: rm me
+    out_c.write("\tLDKSecretKey* key = (LDKSecretKey*)MALLOC(sizeof(LDKSecretKey), \"LDKSecretKey\");\n") # TODO: rm me
+    out_c.write("\treturn (long)key;\n") # TODO: rm me
+    out_c.write("}\n") # TODO: rm me
 
     in_block_comment = False
     in_block_enum = False
@@ -290,8 +500,11 @@ public class bindings {
     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);"))
-    struct_name_regex = re.compile("^typedef struct (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
+    line_field_var_regex = re.compile("^   ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
+    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]*) {$")
     assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
+    assert(struct_name_regex.match("typedef enum LDKNetwork {"))
 
     for line in in_h:
         if in_block_comment:
@@ -306,6 +519,7 @@ public class bindings {
                 struct_lines = cur_block_struct.split("\n")
                 is_opaque = False
                 trait_fn_lines = []
+                field_var_lines = []
 
                 for idx, struct_line in enumerate(struct_lines):
                     if struct_line.strip().startswith("/*"):
@@ -322,6 +536,9 @@ public class bindings {
                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)
+                        field_var_match = line_field_var_regex.match(struct_line)
+                        if field_var_match is not None:
+                            field_var_lines.append(field_var_match)
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)
@@ -329,108 +546,8 @@ public class bindings {
                 if is_opaque:
                     opaque_structs.add(struct_name)
                 if len(trait_fn_lines) > 0:
-                    out_c.write("typedef struct " + struct_name + "_JCalls {\n")
-                    out_c.write("\tJNIEnv *env;\n")
-                    out_c.write("\tjobject o;\n")
-                    for fn_line in trait_fn_lines:
-                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                            out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
-                    out_c.write("} " + struct_name + "_JCalls;\n")
-
-                    out_java.write("\tpublic interface " + struct_name + " {\n")
-                    java_meths = []
-                    for fn_line in trait_fn_lines:
-                        java_meth_descr = "("
-                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                            ret_ty_info = java_c_types(fn_line.group(1), None)
-
-                            out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")
-                            is_const = fn_line.group(3) is not None
-                            out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
-                            if is_const:
-                                out_c.write("const void* this_arg")
-                            else:
-                                out_c.write("void* this_arg")
-
-                            arg_names = []
-                            for idx, arg in enumerate(fn_line.group(4).split(',')):
-                                if arg == "":
-                                    continue
-                                if idx >= 2:
-                                    out_java.write(", ")
-                                out_c.write(", ")
-                                arg_conv_info = map_type(arg, True, None, False)
-                                out_c.write(arg.strip())
-                                out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
-                                arg_names.append(arg_conv_info)
-                                java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
-                            java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
-                            java_meths.append(java_meth_descr)
-
-                            out_java.write(");\n")
-                            out_c.write(") {\n")
-                            out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\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(arg_info.arg_name)
-                                    out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "j_calls->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")
-                            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");
-
-                            for arg_info in arg_names:
-                                if arg_info.ret_conv is not None:
-                                    out_c.write(", " + arg_info.ret_conv_name)
-                                else:
-                                    out_c.write(", " + arg_info.arg_name)
-                            out_c.write(");\n");
-
-                            if ret_ty_info.passed_as_ptr:
-                                out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
-                                out_c.write("\tfree(ret);\n")
-                                out_c.write("\treturn res;\n")
-                            out_c.write("}\n")
-                        elif fn_line.group(2) == "free":
-                            out_c.write("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("\t(*j_calls->env)->DeleteGlobalRef(j_calls->env, j_calls->o);\n")
-                            out_c.write("\tfree(j_calls);\n")
-                            out_c.write("}\n")
-                        elif fn_line.group(2) == "clone":
-                            out_c.write("void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
-                            out_c.write("\t" + struct_name + "_JCalls *ret = malloc(sizeof(" + struct_name + "_JCalls));\n")
-                            out_c.write("\tmemcpy(ret, this_arg, sizeof(" + struct_name + "_JCalls));\n")
-                            out_c.write("\treturn ret;\n")
-                            out_c.write("}\n")
-                    out_java.write("\t}\n")
-                    out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl);\n")
-
-                    out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o) {\n")
-                    out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
-                    out_c.write("\tassert(c != NULL);\n")
-                    out_c.write("\t" + struct_name + "_JCalls *calls = malloc(sizeof(" + struct_name + "_JCalls));\n")
-                    out_c.write("\tcalls->env = env;\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("\n\t" + struct_name + " *ret = malloc(sizeof(" + struct_name + "));\n")
-                    out_c.write("\tret->this_arg = (void*) calls;\n")
-                    for fn_line in trait_fn_lines:
-                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                            out_c.write("\tret->" + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall;\n")
-                        elif fn_line.group(2) == "free":
-                            out_c.write("\tret->free = " + struct_name + "_JCalls_free;\n")
-                        else:
-                            out_c.write("\tret->clone = " + struct_name + "_JCalls_clone;\n")
-                    out_c.write("\treturn (long)ret;\n")
-                    out_c.write("}\n\n")
-
+                    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: