python_strings.py

from bindingstypes import ConvInfo
from enum import Enum

def first_to_lower(string: str) -> str:
    first = string[0]
    return first.lower() + string[1:]


class Target(Enum):
    PYTHON = 1,

class Consts:
    def __init__(self, DEBUG: bool, target: Target, outdir: str, **kwargs):
        self.outdir = outdir
        self.struct_file_suffixes = {}
        self.function_ptr_counter = 0
        self.function_ptrs = {}
        self.c_type_map = dict(
            bool = ['bool', 'bool', 'XXX'],
            uint8_t = ['int', 'int', 'Uint8Array'],
            uint16_t = ['int', 'int', 'Uint16Array'],
            uint32_t = ['int', 'int', 'Uint32Array'],
            uint64_t = ['int', 'int', 'BigUint64Array'],
        )
        self.java_type_map = dict(
            String = "number"
        )
        self.java_hu_type_map = dict(
            String = "string"
        )

        self.to_hu_conv_templates = dict(
            ptr = 'const {var_name}_hu_conv: {human_type} = new {human_type}(null, {var_name});',
            default = 'const {var_name}_hu_conv: {human_type} = new {human_type}(null, {var_name});',
        )

        self.bindings_header = """
import * as version from './version.mjs';
import { UInt5, WitnessVersion } from './structs/CommonBase.mjs';

const imports: any = {};
imports.env = {};

var js_objs: Array<WeakRef<object>> = [];
var js_invoke: Function;
var getRandomValues: Function;

imports.wasi_snapshot_preview1 = {
	"fd_write": (fd: number, iovec_array_ptr: number, iovec_array_len: number, bytes_written_ptr: number) => {
		// This should generally only be used to print panic messages
		const ptr_len_view = new Uint32Array(wasm.memory.buffer, iovec_array_ptr, iovec_array_len * 2);
		var bytes_written = 0;
		for (var i = 0; i < iovec_array_len; i++) {
			const bytes_view = new Uint8Array(wasm.memory.buffer, ptr_len_view[i*2], ptr_len_view[i*2+1]);
			console.log("[fd " + fd + "]: " + String.fromCharCode(...bytes_view));
			bytes_written += ptr_len_view[i*2+1]!;
		}
		const written_view = new Uint32Array(wasm.memory.buffer, bytes_written_ptr, 1);
		written_view[0] = bytes_written;
		return 0;
	},
	"fd_close": (_fd: number) => {
		// This is not generally called, but may be referenced in debug builds
		console.log("wasi_snapshot_preview1:fd_close");
		return 58; // Not Supported
	},
	"fd_seek": (_fd: number, _offset: bigint, _whence: number, _new_offset: number) => {
		// This is not generally called, but may be referenced in debug builds
		console.log("wasi_snapshot_preview1:fd_seek");
		return 58; // Not Supported
	},
	"random_get": (buf_ptr: number, buf_len: number) => {
		const buf = new Uint8Array(wasm.memory.buffer, buf_ptr, buf_len);
		getRandomValues(buf);
		return 0;
	},
	"environ_sizes_get": (environ_var_count_ptr: number, environ_len_ptr: number) => {
		// This is called before fd_write to format + print panic messages
		const out_count_view = new Uint32Array(wasm.memory.buffer, environ_var_count_ptr, 1);
		out_count_view[0] = 0;
		const out_len_view = new Uint32Array(wasm.memory.buffer, environ_len_ptr, 1);
		out_len_view[0] = 0;
		return 0;
	},
	"environ_get": (_environ_ptr: number, _environ_buf_ptr: number) => {
		// This is called before fd_write to format + print panic messages,
		// but only if we have variables in environ_sizes_get, so shouldn't ever actually happen!
		console.log("wasi_snapshot_preview1:environ_get");
		return 58; // Note supported - we said there were 0 environment entries!
	},
	"proc_exit" : () => {
		console.log("wasi_snapshot_preview1:proc_exit");
	},
};

var wasm: any = null;
let isWasmInitialized: boolean = false;

async function finishInitializeWasm(wasmInstance: WebAssembly.Instance) {
	if (typeof crypto === "undefined") {
		var crypto_import = (await import('crypto')).webcrypto;
		getRandomValues = crypto_import.getRandomValues.bind(crypto_import);
	} else {
		getRandomValues = crypto.getRandomValues.bind(crypto);
	}

	wasm = wasmInstance.exports;
	if (!wasm.test_bigint_pass_deadbeef0badf00d(BigInt("0xdeadbeef0badf00d"))) {
		throw new Error(\"Currently need BigInt-as-u64 support, try ----experimental-wasm-bigint");
	}

	if (decodeString(wasm.TS_get_lib_version_string()) !== version.get_ldk_java_bindings_version())
		throw new Error(\"Compiled LDK library and LDK class files do not match\");
	// Fetching the LDK versions from C also checks that the header and binaries match
	const c_bindings_ver: number = wasm.TS_get_ldk_c_bindings_version();
	const ldk_ver: number = wasm.TS_get_ldk_version();
	if (c_bindings_ver == 0)
		throw new Error(\"LDK version did not match the header we built against\");
	if (ldk_ver == 0)
		throw new Error(\"LDK C bindings version did not match the header we built against\");
	const c_bindings_version: string = decodeString(c_bindings_ver)
	const ldk_version: string = decodeString(ldk_ver);
	console.log(\"Loaded LDK-Java Bindings with LDK \" + ldk_version + \" and LDK-C-Bindings \" + c_bindings_version);

	isWasmInitialized = true;
}

const fn_list = ["uuuuuu", "buuuuu", "bbuuuu", "bbbuuu", "bbbbuu",
	"bbbbbb", "ubuubu", "ubuuuu", "ubbuuu", "uubuuu", "uububu", "ububuu"];

/* @internal */
export async function initializeWasmFromUint8Array(wasmBinary: Uint8Array) {
	for (const fn of fn_list) { imports.env["js_invoke_function_" + fn] = js_invoke; }
	const { instance: wasmInstance } = await WebAssembly.instantiate(wasmBinary, imports);
	await finishInitializeWasm(wasmInstance);
}

/* @internal */
export async function initializeWasmFetch(uri: string) {
	for (const fn of fn_list) { imports.env["js_invoke_function_" + fn] = js_invoke; }
	const stream = fetch(uri);
	const { instance: wasmInstance } = await WebAssembly.instantiateStreaming(stream, imports);
	await finishInitializeWasm(wasmInstance);
}"""

        self.bindings_header += """
// WASM CODEC

/* @internal */
export function uint5ArrToBytes(inputArray: Array<UInt5>): Uint8Array {
	const arr = new Uint8Array(inputArray.length);
	for (var i = 0; i < inputArray.length; i++) {
		arr[i] = inputArray[i]!.getVal();
	}
	return arr;
}

/* @internal */
export function WitnessVersionArrToBytes(inputArray: Array<WitnessVersion>): Uint8Array {
	const arr = new Uint8Array(inputArray.length);
	for (var i = 0; i < inputArray.length; i++) {
		arr[i] = inputArray[i]!.getVal();
	}
	return arr;
}



/* @internal */
export function encodeUint128 (inputVal: bigint): number {
	if (inputVal >= 0x10000000000000000000000000000000n) throw "U128s cannot exceed 128 bits";
	const cArrayPointer = wasm.TS_malloc(16 + 8);
	const arrayLengthView = new BigUint64Array(wasm.memory.buffer, cArrayPointer, 1);
	arrayLengthView[0] = BigInt(16);
	const arrayMemoryView = new Uint8Array(wasm.memory.buffer, cArrayPointer + 8, 16);
	for (var i = 0; i < 16; i++) arrayMemoryView[i] = Number((inputVal >> BigInt(i)*8n) & 0xffn);
	return cArrayPointer;
}
/* @internal */
export function encodeUint8Array (inputArray: Uint8Array|null): number {
	if (inputArray == null) return 0;
	const cArrayPointer = wasm.TS_malloc(inputArray.length + 8);
	const arrayLengthView = new BigUint64Array(wasm.memory.buffer, cArrayPointer, 1);
	arrayLengthView[0] = BigInt(inputArray.length);
	const arrayMemoryView = new Uint8Array(wasm.memory.buffer, cArrayPointer + 8, inputArray.length);
	arrayMemoryView.set(inputArray);
	return cArrayPointer;
}
/* @internal */
export function encodeUint32Array (inputArray: Uint32Array|Array<number>|null): number {
	if (inputArray == null) return 0;
	const cArrayPointer = wasm.TS_malloc((inputArray.length + 2) * 4);
	const arrayLengthView = new BigUint64Array(wasm.memory.buffer, cArrayPointer, 1);
	arrayLengthView[0] = BigInt(inputArray.length);
	const arrayMemoryView = new Uint32Array(wasm.memory.buffer, cArrayPointer + 8, inputArray.length);
	arrayMemoryView.set(inputArray);
	return cArrayPointer;
}
/* @internal */
export function encodeUint64Array (inputArray: BigUint64Array|Array<bigint>|null): number {
	if (inputArray == null) return 0;
	const cArrayPointer = wasm.TS_malloc((inputArray.length + 1) * 8);
	const arrayMemoryView = new BigUint64Array(wasm.memory.buffer, cArrayPointer, inputArray.length + 1);
	arrayMemoryView[0] = BigInt(inputArray.length);
	arrayMemoryView.set(inputArray, 1);
	return cArrayPointer;
}

/* @internal */
export function check_arr_len(arr: Uint8Array|null, len: number): Uint8Array|null {
	if (arr !== null && arr.length != len) { throw new Error("Expected array of length " + len + " got " + arr.length); }
	return arr;
}

/* @internal */
export function getArrayLength(arrayPointer: number): number {
	const arraySizeViewer = new BigUint64Array(wasm.memory.buffer, arrayPointer, 1);
	const len = arraySizeViewer[0]!;
	if (len >= (2n ** 32n)) throw new Error("Bogus Array Size");
	return Number(len % (2n ** 32n));
}
/* @internal */
export function decodeUint128 (arrayPointer: number, free = true): bigint {
	const arraySize = getArrayLength(arrayPointer);
	if (arraySize != 16) throw "Need 16 bytes for a uint128";
	const actualArrayViewer = new Uint8Array(wasm.memory.buffer, arrayPointer + 8, arraySize);
	var val = 0n;
	for (var i = 0; i < 16; i++) {
		val <<= 8n;
		val |= BigInt(actualArrayViewer[i]!);
	}
	if (free) {
		wasm.TS_free(arrayPointer);
	}
	return val;
}
/* @internal */
export function decodeUint8Array (arrayPointer: number, free = true): Uint8Array {
	const arraySize = getArrayLength(arrayPointer);
	const actualArrayViewer = new Uint8Array(wasm.memory.buffer, arrayPointer + 8, arraySize);
	// Clone the contents, TODO: In the future we should wrap the Viewer in a class that
	// will free the underlying memory when it becomes unreachable instead of copying here.
	// Note that doing so may have edge-case interactions with memory resizing (invalidating the buffer).
	const actualArray = actualArrayViewer.slice(0, arraySize);
	if (free) {
		wasm.TS_free(arrayPointer);
	}
	return actualArray;
}
const decodeUint32Array = (arrayPointer: number, free = true) => {
	const arraySize = getArrayLength(arrayPointer);
	const actualArrayViewer = new Uint32Array(
		wasm.memory.buffer, // value
		arrayPointer + 8, // offset (ignoring length bytes)
		arraySize // uint32 count
	);
	// Clone the contents, TODO: In the future we should wrap the Viewer in a class that
	// will free the underlying memory when it becomes unreachable instead of copying here.
	const actualArray = actualArrayViewer.slice(0, arraySize);
	if (free) {
		wasm.TS_free(arrayPointer);
	}
	return actualArray;
}
/* @internal */
export function decodeUint64Array (arrayPointer: number, free = true): bigint[] {
	const arraySize = getArrayLength(arrayPointer);
	const actualArrayViewer = new BigUint64Array(
		wasm.memory.buffer, // value
		arrayPointer + 8, // offset (ignoring length bytes)
		arraySize // uint32 count
	);
	// Clone the contents, TODO: In the future we should wrap the Viewer in a class that
	// will free the underlying memory when it becomes unreachable instead of copying here.
	const actualArray = new Array(arraySize);
	for (var i = 0; i < arraySize; i++) actualArray[i] = actualArrayViewer[i];
	if (free) {
		wasm.TS_free(arrayPointer);
	}
	return actualArray;
}

export function freeWasmMemory(pointer: number) { wasm.TS_free(pointer); }

/* @internal */
export function getU64ArrayElem(arrayPointer: number, idx: number): bigint {
	const actualArrayViewer = new BigUint64Array(wasm.memory.buffer, arrayPointer + 8, idx + 1);
	return actualArrayViewer[idx]!;
}

/* @internal */
export function getU32ArrayElem(arrayPointer: number, idx: number): number {
	const actualArrayViewer = new Uint32Array(wasm.memory.buffer, arrayPointer + 8, idx + 1);
	return actualArrayViewer[idx]!;
}

/* @internal */
export function getU8ArrayElem(arrayPointer: number, idx: number): number {
	const actualArrayViewer = new Uint8Array(wasm.memory.buffer, arrayPointer + 8, idx + 1);
	return actualArrayViewer[idx]!;
}


/* @internal */
export function encodeString(str: string): number {
	const charArray = new TextEncoder().encode(str);
	return encodeUint8Array(charArray);
}

/* @internal */
export function decodeString(stringPointer: number, free = true): string {
	const arraySize = getArrayLength(stringPointer);
	const memoryView = new Uint8Array(wasm.memory.buffer, stringPointer + 8, arraySize);
	const result = new TextDecoder("utf-8").decode(memoryView);

	if (free) {
		wasm.TS_free(stringPointer);
	}

	return result;
}
"""
        if DEBUG:
            self.bindings_header += """
/* @internal */
export function getRemainingAllocationCount(): number {
	return wasm.TS_allocs_remaining();
}
/* @internal */
export function debugPrintRemainingAllocs() {
	wasm.TS_print_leaks();
}
"""
        else:
            self.bindings_header += "\n/* @internal */ export function getRemainingAllocationCount(): number { return 0; }\n"
            self.bindings_header += "/* @internal */ export function debugPrintRemainingAllocs() { }\n"

        with open(outdir + "/index.py", 'a') as index:
            index.write("""import { initializeWasmFetch, initializeWasmFromUint8Array } from './bindings.mjs';
/** Initializes the WASM backend by calling `fetch()` on the given URI - Browser only */
export async function initializeWasmWebFetch(uri: string) {
	await initializeWasmFetch(uri);
}
/** Initializes the WASM backend given a Uint8Array of the .wasm binary file - Browser or Node.JS */
export async function initializeWasmFromBinary(bin: Uint8Array) {
	await initializeWasmFromUint8Array(bin);
}

""")

        self.bindings_version_file = """export function get_ldk_java_bindings_version(): String {
	return "<git_version_ldk_garbagecollected>";
}"""

        self.common_base = """
function freer(f: () => void) { f() }
const finalizer = new FinalizationRegistry(freer);
function get_freeer(ptr: bigint, free_fn: (ptr: bigint) => void) {
	return () => {
		free_fn(ptr);
	}
}

export class UInt5 {
	public constructor(private val: number) {
		if (val > 32 || val < 0) throw new Error("UInt5 value is out of range");
	}
	public getVal(): number {
		return this.val;
	}
}

export class WitnessVersion {
	public constructor(private val: number) {
		if (val > 16 || val < 0) throw new Error("WitnessVersion value is out of range");
	}
	public getVal(): number {
		return this.val;
	}
}

export class UnqualifiedError {
	public constructor(_val: number) {}
}
"""

        self.txout_defn = """export class TxOut extends CommonBase {
	/** The script_pubkey in this output */
	public script_pubkey: Uint8Array;
	/** The value, in satoshis, of this output */
	public value: bigint;

	/* @internal */
	public constructor(_dummy: null, ptr: bigint) {
		super(ptr, bindings.TxOut_free);
		this.script_pubkey = bindings.decodeUint8Array(bindings.TxOut_get_script_pubkey(ptr));
		this.value = bindings.TxOut_get_value(ptr);
	}
	public static constructor_new(value: bigint, script_pubkey: Uint8Array): TxOut {
		return new TxOut(null, bindings.TxOut_new(bindings.encodeUint8Array(script_pubkey), value));
	}
}"""
        self.obj_defined(["TxOut"], "structs")

        self.address_defn = """export class Address extends CommonBase {
	/** The address in string form */
	public address: String;

	/* @internal */
	public constructor(_dummy: null, ptr: bigint) {
		super(ptr, bindings.Address_free);
		this.script_pubkey = bindings.decodeString(bindings.Address_to_string(ptr));
	}
}"""
        self.obj_defined(["Address"], "structs")

        self.scalar_defn = """export class BigEndianScalar extends CommonBase {
	/** The bytes of the scalar value, in big endian */
	public scalar_bytes: Uint8Array;

	/* @internal */
	public constructor(_dummy: null, ptr: bigint) {
		super(ptr, bindings.BigEndianScalar_free);
		this.scalar_bytes = bindings.decodeUint8Array(bindings.BigEndianScalar_get_bytes(ptr));
	}
	public static constructor_new(scalar_bytes: Uint8Array): BigEndianScalar {
		return new BigEndianScalar(null, bindings.BigEndianScalar_new(bindings.encodeUint8Array(scalar_bytes)));
	}
}"""
        self.obj_defined(["BigEndianScalar"], "structs")

        self.c_file_pfx = """#include "js-wasm.h"
#include <stdatomic.h>
#include <lightning.h>

// These should be provided...somehow...
void *memset(void *s, int c, size_t n);
void *memcpy(void *dest, const void *src, size_t n);
int memcmp(const void *s1, const void *s2, size_t n);

extern void __attribute__((noreturn)) abort(void);
static inline void assert(bool expression) {
	if (!expression) { abort(); }
}

uint32_t __attribute__((export_name("test_bigint_pass_deadbeef0badf00d"))) test_bigint_pass_deadbeef0badf00d(uint64_t val) {
	return val == 0xdeadbeef0badf00dULL;
}

"""

        if not DEBUG:
            self.c_file_pfx += """
void *malloc(size_t size);
void free(void *ptr);

#define MALLOC(a, _) malloc(a)
#define do_MALLOC(a, _b, _c) malloc(a)
#define FREE(p) if ((unsigned long)(p) > 4096) { free(p); }
#define DO_ASSERT(a) (void)(a)
#define CHECK(a)
#define CHECK_ACCESS(p)
#define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
"""
        else:
            self.c_file_pfx += """
extern int snprintf(char *str, size_t size, const char *format, ...);
typedef int32_t ssize_t;
ssize_t write(int fd, const void *buf, size_t count);
#define DEBUG_PRINT(...) do { \\
	char debug_str[1024]; \\
	int s_len = snprintf(debug_str, 1023, __VA_ARGS__); \\
	write(2, debug_str, s_len); \\
} while (0);

// Always run a, then assert it is true:
#define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
// Assert a is true or do nothing
#define CHECK(a) DO_ASSERT(a)

// 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.

#define BT_MAX 128
typedef struct allocation {
	struct allocation* next;
	void* ptr;
	const char* struct_name;
	int lineno;
} allocation;
static allocation* allocation_ll = NULL;
static allocation* freed_ll = NULL;

extern void* __real_malloc(size_t len);
extern void* __real_calloc(size_t nmemb, size_t len);
extern void* __real_aligned_alloc(size_t alignment, size_t size);
static void new_allocation(void* res, const char* struct_name, int lineno) {
	allocation* new_alloc = __real_malloc(sizeof(allocation));
	new_alloc->ptr = res;
	new_alloc->struct_name = struct_name;
	new_alloc->next = allocation_ll;
	new_alloc->lineno = lineno;
	allocation_ll = new_alloc;
}
static void* do_MALLOC(size_t len, const char* struct_name, int lineno) {
	void* res = __real_malloc(len);
	new_allocation(res, struct_name, lineno);
	return res;
}
#define MALLOC(len, struct_name) do_MALLOC(len, struct_name, __LINE__)

void __real_free(void* ptr);
static void alloc_freed(void* ptr, int lineno) {
	allocation* p = NULL;
	allocation* it = allocation_ll;
	while (it->ptr != ptr) {
		p = it; it = it->next;
		if (it == NULL) {
			p = NULL;
			it = freed_ll;
			while (it && it->ptr != ptr) { p = it; it = it->next; }
			if (it == NULL) {
				DEBUG_PRINT("Tried to free unknown pointer %p at line %d.\\n", ptr, lineno);
			} else {
				DEBUG_PRINT("Tried to free unknown pointer %p at line %d.\\n Possibly double-free from %s, allocated on line %d.", ptr, lineno, it->struct_name, it->lineno);
			}
			abort();
		}
	}
	if (p) { p->next = it->next; } else { allocation_ll = it->next; }
	DO_ASSERT(it->ptr == ptr);
	it->next = freed_ll;
	freed_ll = it;
}
static void do_FREE(void* ptr, int lineno) {
	if ((unsigned long)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
	alloc_freed(ptr, lineno);
	__real_free(ptr);
}
#define FREE(ptr) do_FREE(ptr, __LINE__)

static void CHECK_ACCESS(const void* ptr) {
	allocation* it = allocation_ll;
	while (it->ptr != ptr) {
		it = it->next;
		if (it == NULL) {
			return; // addrsan should catch malloc-unknown and print more info than we have
		}
	}
}
#define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
	if (v.is_owned && v.inner != NULL) { \\
		const void *p = __unmangle_inner_ptr(v.inner); \\
		if (p != NULL) { \\
			CHECK_ACCESS(p); \\
		} \\
	}

void* __wrap_malloc(size_t len) {
	void* res = __real_malloc(len);
	new_allocation(res, "malloc call", 0);
	return res;
}
void* __wrap_calloc(size_t nmemb, size_t len) {
	void* res = __real_calloc(nmemb, len);
	new_allocation(res, "calloc call", 0);
	return res;
}
void* __wrap_aligned_alloc(size_t alignment, size_t size) {
	void* res = __real_aligned_alloc(alignment, size);
	new_allocation(res, "aligned_alloc call", 0);
	return res;
}
void __wrap_free(void* ptr) {
	if (ptr == NULL) return;
	alloc_freed(ptr, 0);
	__real_free(ptr);
}

void* __real_realloc(void* ptr, size_t newlen);
void* __wrap_realloc(void* ptr, size_t len) {
	if (ptr != NULL) alloc_freed(ptr, 0);
	void* res = __real_realloc(ptr, len);
	new_allocation(res, "realloc call", 0);
	return res;
}
void __wrap_reallocarray(void* ptr, size_t new_sz) {
	// Rust doesn't seem to use reallocarray currently
	DO_ASSERT(false);
}

uint32_t __attribute__((export_name("TS_allocs_remaining"))) allocs_remaining() {
	uint32_t count = 0;
	for (allocation* a = allocation_ll; a != NULL; a = a->next) {
		count++;
	}
	return count;
}
void __attribute__((export_name("TS_print_leaks"))) print_leaks() {
	for (allocation* a = allocation_ll; a != NULL; a = a->next) {
		DEBUG_PRINT("%s %p remains. Allocated on line %d\\n", a->struct_name, a->ptr, a->lineno);
	}
}
"""
        self.c_file_pfx = self.c_file_pfx + """
// 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");

_Static_assert(sizeof(void*) == 4, "Pointers mut be 32 bits");

#define DECL_ARR_TYPE(ty, name) \\
	struct name##array { \\
		uint64_t arr_len; /* uint32_t would suffice but we want to align uint64_ts as well */ \\
		ty elems[]; \\
	}; \\
	typedef struct name##array * name##Array; \\
	static inline name##Array init_##name##Array(size_t arr_len, int lineno) { \\
		name##Array arr = (name##Array)do_MALLOC(arr_len * sizeof(ty) + sizeof(uint64_t), #name" array init", lineno); \\
		arr->arr_len = arr_len; \\
		return arr; \\
	}

DECL_ARR_TYPE(int64_t, int64_t);
DECL_ARR_TYPE(uint64_t, uint64_t);
DECL_ARR_TYPE(int8_t, int8_t);
DECL_ARR_TYPE(uint32_t, uint32_t);
DECL_ARR_TYPE(void*, ptr);
DECL_ARR_TYPE(char, char);
typedef charArray jstring;

static inline jstring str_ref_to_ts(const char* chars, size_t len) {
	charArray arr = init_charArray(len, __LINE__);
	memcpy(arr->elems, chars, len);
	return arr;
}
static inline LDKStr str_ref_to_owned_c(const jstring str) {
	char* newchars = MALLOC(str->arr_len + 1, "String chars");
	memcpy(newchars, str->elems, str->arr_len);
	newchars[str->arr_len] = 0;
	LDKStr res = {
		.chars = newchars,
		.len = str->arr_len,
		.chars_is_owned = true
	};
	return res;
}

typedef bool jboolean;

uint32_t __attribute__((export_name("TS_malloc"))) TS_malloc(uint32_t size) {
	return (uint32_t)MALLOC(size, "JS-Called malloc");
}
void __attribute__((export_name("TS_free"))) TS_free(uint32_t ptr) {
	FREE((void*)ptr);
}

jstring __attribute__((export_name("TS_get_ldk_c_bindings_version"))) TS_get_ldk_c_bindings_version() {
	const char *res = check_get_ldk_bindings_version();
	if (res == NULL) return NULL;
	return str_ref_to_ts(res, strlen(res));
}
jstring __attribute__((export_name("TS_get_ldk_version"))) get_ldk_version() {
	const char *res = check_get_ldk_version();
	if (res == NULL) return NULL;
	return str_ref_to_ts(res, strlen(res));
}
#include "version.c"
"""

        self.c_version_file = """jstring __attribute__((export_name("TS_get_lib_version_string"))) TS_get_lib_version_string() {
	return str_ref_to_ts("<git_version_ldk_garbagecollected>", strlen("<git_version_ldk_garbagecollected>"));
}"""

        self.hu_struct_file_prefix = """
import { CommonBase, UInt5, WitnessVersion, UnqualifiedError } from './CommonBase.mjs';
import * as bindings from '../bindings.mjs'

"""
        self.hu_struct_file_suffix = ""
        self.util_fn_pfx = self.hu_struct_file_prefix + "\nexport class UtilMethods extends CommonBase {\n"
        self.util_fn_sfx = "}"
        self.c_fn_ty_pfx = ""
        self.file_ext = ".py"
        self.ptr_c_ty = "uint64_t"
        self.ptr_native_ty = "bigint"
        self.u128_native_ty = "bigint"
        self.usize_c_ty = "uint32_t"
        self.usize_native_ty = "number"
        self.native_zero_ptr = "0n"
        self.unitary_enum_c_ty = "uint32_t"
        self.ptr_arr = "ptrArray"
        self.is_arr_some_check = ("", " != 0")
        self.get_native_arr_len_call = ("", "->arr_len")

    def bindings_footer(self):
        return ""

    def release_native_arr_ptr_call(self, ty_info, arr_var, arr_ptr_var):
        return None
    def create_native_arr_call(self, arr_len, ty_info):
        if ty_info.c_ty == "ptrArray":
            assert ty_info.rust_obj == "LDKCVec_U5Z" or (ty_info.subty is not None and ty_info.subty.c_ty.endswith("Array"))
        return "init_" + ty_info.c_ty + "(" + arr_len + ", __LINE__)"
    def set_native_arr_contents(self, arr_name, arr_len, ty_info):
        if ty_info.c_ty == "int8_tArray":
            return ("memcpy(" + arr_name + "->elems, ", ", " + arr_len + ")")
        else:
            assert False
    def get_native_arr_contents(self, arr_name, dest_name, arr_len, ty_info, copy):
        if ty_info.c_ty == "int8_tArray":
            if copy:
                return "memcpy(" + dest_name + ", " + arr_name + "->elems, " + arr_len + "); FREE(" + arr_name + ")"
        assert not copy
        if ty_info.c_ty == "ptrArray":
            return "(void*) " + arr_name + "->elems"
        else:
            return arr_name + "->elems"
    def get_native_arr_elem(self, arr_name, idxc, ty_info):
        assert False # Only called if above is None
    def get_native_arr_ptr_call(self, ty_info):
        if ty_info.subty is not None:
            return "(" + ty_info.subty.c_ty + "*)(((uint8_t*)", ") + 8)"
        return "(" + ty_info.c_ty + "*)(((uint8_t*)", ") + 8)"
    def get_native_arr_entry_call(self, ty_info, arr_name, idxc, entry_access):
        return None
    def cleanup_native_arr_ref_contents(self, arr_name, dest_name, arr_len, ty_info):
        if ty_info.c_ty == "int8_tArray":
            return "FREE(" + arr_name + ");"
        else:
            return "FREE(" + arr_name + ")"

    def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
        if elem_ty.rust_obj == "LDKU5":
            return arr_name + " != null ? bindings.uint5ArrToBytes(" + arr_name + ") : null"
        assert elem_ty.c_ty == "uint64_t" or elem_ty.c_ty.endswith("Array")
        return arr_name + " != null ? " + arr_name + ".map(" + conv_name + " => " + elem_ty.from_hu_conv[0] + ") : null"

    def str_ref_to_native_call(self, var_name, str_len):
        return "str_ref_to_ts(" + var_name + ", " + str_len + ")"
    def str_ref_to_c_call(self, var_name):
        return "str_ref_to_owned_c(" + var_name + ")"
    def str_to_hu_conv(self, var_name):
        return "const " + var_name + "_conv: string = bindings.decodeString(" + var_name + ");"
    def str_from_hu_conv(self, var_name):
        return ("bindings.encodeString(" + var_name + ")", "")

    def c_fn_name_define_pfx(self, fn_name, have_args):
        return " __attribute__((export_name(\"TS_" + fn_name + "\"))) TS_" + fn_name + "("

    def init_str(self):
        return ""

    def get_java_arr_len(self, arr_name):
        return "bindings.getArrayLength(" + arr_name + ")"
    def get_java_arr_elem(self, elem_ty, arr_name, idx):
        if elem_ty.c_ty.endswith("Array") or elem_ty.c_ty == "uintptr_t":
            return "bindings.getU32ArrayElem(" + arr_name + ", " + idx + ")"
        elif elem_ty.c_ty == "uint64_t":
            return "bindings.getU64ArrayElem(" + arr_name + ", " + idx + ")"
        elif elem_ty.rust_obj == "LDKU5":
            return "bindings.getU8ArrayElem(" + arr_name + ", " + idx + ")"
        else:
            assert False
    def constr_hu_array(self, ty_info, arr_len):
        return "new Array(" + arr_len + ").fill(null)"
    def cleanup_converted_native_array(self, ty_info, arr_name):
        return "bindings.freeWasmMemory(" + arr_name + ")"

    def primitive_arr_from_hu(self, arr_ty, fixed_len, arr_name):
        mapped_ty = arr_ty.subty
        inner = arr_name
        if arr_ty.rust_obj == "LDKU128":
            return ("bindings.encodeUint128(" + inner + ")", "")
        if fixed_len is not None:
            assert mapped_ty.c_ty == "int8_t"
            inner = "bindings.check_arr_len(" + arr_name + ", " + fixed_len + ")"
        if mapped_ty.c_ty.endswith("Array"):
            return ("bindings.encodeUint32Array(" + inner + ")", "")
        elif mapped_ty.c_ty == "uint8_t" or mapped_ty.c_ty == "int8_t":
            return ("bindings.encodeUint8Array(" + inner + ")", "")
        elif mapped_ty.c_ty == "uint32_t":
            return ("bindings.encodeUint32Array(" + inner + ")", "")
        elif mapped_ty.c_ty == "int64_t" or mapped_ty.c_ty == "uint64_t":
            return ("bindings.encodeUint64Array(" + inner + ")", "")
        else:
            print(mapped_ty.c_ty)
            assert False

    def primitive_arr_to_hu(self, arr_ty, fixed_len, arr_name, conv_name):
        mapped_ty = arr_ty.subty
        if arr_ty.rust_obj == "LDKU128":
            return "const " + conv_name + ": bigint = bindings.decodeUint128(" + arr_name + ");"
        elif mapped_ty.c_ty == "uint8_t" or mapped_ty.c_ty == "int8_t":
            return "const " + conv_name + ": Uint8Array = bindings.decodeUint8Array(" + arr_name + ");"
        elif mapped_ty.c_ty == "uint64_t" or mapped_ty.c_ty == "int64_t":
            return "const " + conv_name + ": bigint[] = bindings.decodeUint64Array(" + arr_name + ");"
        else:
            assert False

    def var_decl_statement(self, ty_string, var_name, statement):
        return "const " + var_name + ": " + ty_string + " = " + statement

    def java_arr_ty_str(self, elem_ty_str):
        return "number"

    def for_n_in_range(self, n, minimum, maximum):
        return "for (var " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
    def for_n_in_arr(self, n, arr_name, arr_elem_ty):
        return (arr_name + ".forEach((" + n + ": " + arr_elem_ty.java_hu_ty + ") => { ", " })")

    def get_ptr(self, var):
        return "CommonBase.get_ptr_of(" + var + ")"
    def set_null_skip_free(self, var):
        return "CommonBase.set_null_skip_free(" + var + ");"

    def add_ref(self, holder, referent):
        return "CommonBase.add_ref_from(" + holder + ", " + referent + ")"

    def obj_defined(self, struct_names, folder):
        with open(self.outdir + "/index.py", 'a') as index:
            index.write(f"export * from './{folder}/{struct_names[0]}.mjs';\n")
        with open(self.outdir + "/imports.py.part", 'a') as imports:
            imports.write(f"import {{ {', '.join(struct_names)} }} from '../{folder}/{struct_names[0]}.mjs';\n")

    def fully_qualified_hu_ty_path(self, ty):
        return ty.java_hu_ty

    def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
        out_c = "static inline LDK" + struct_name + " LDK" + struct_name + "_from_js(int32_t ord) {\n"
        out_c = out_c + "\tswitch (ord) {\n"
        ord_v = 0

        out_typescript_enum_fields = ""

        for var, var_docs in variants:
            out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
            ord_v = ord_v + 1
            if var_docs is not None:
                var_docs_repld = var_docs.replace("\n", "\n\t")
                out_typescript_enum_fields += f"/**\n\t * {var_docs_repld}\n\t */\n"
            out_typescript_enum_fields += f"\t{var},\n\t"
        out_c = out_c + "\t}\n"
        out_c = out_c + "\tabort();\n"
        out_c = out_c + "}\n"

        out_c = out_c + "static inline int32_t LDK" + struct_name + "_to_js(LDK" + struct_name + " val) {\n"
        out_c = out_c + "\tswitch (val) {\n"
        ord_v = 0
        for var, _ in variants:
            out_c = out_c + "\t\tcase " + var + ": return %d;\n" % ord_v
            ord_v = ord_v + 1
        out_c = out_c + "\t\tdefault: abort();\n"
        out_c = out_c + "\t}\n"
        out_c = out_c + "}\n"

        # Note that this is *not* marked /* @internal */ as we re-expose it directly in enums/
        enum_comment_formatted = enum_doc_comment.replace("\n", "\n * ")
        out_typescript = f"""
/**
 * {enum_comment_formatted}
 */
export enum {struct_name} {{
	{out_typescript_enum_fields}
}}
"""
        out_typescript_enum = f"export {{ {struct_name} }} from \"../bindings.mjs\";"
        self.obj_defined([struct_name], "enums")
        return (out_c, out_typescript_enum, out_typescript)

    def c_unitary_enum_to_native_call(self, ty_info):
        return (ty_info.rust_obj + "_to_js(", ")")
    def native_unitary_enum_to_c_call(self, ty_info):
        return (ty_info.rust_obj + "_from_js(", ")")

    def native_c_map_trait(self, struct_name, field_var_conversions, flattened_field_var_conversions, field_function_lines, trait_doc_comment):
        out_typescript_bindings = ""
        super_instantiator = ""
        bindings_instantiator = ""
        pointer_to_adder = ""
        impl_constructor_arguments = ""
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                impl_constructor_arguments += f", {var.arg_name}: {var.java_hu_ty}"
                super_instantiator += first_to_lower(var.arg_name) + ", "
                if var.from_hu_conv is not None:
                    bindings_instantiator += ", " + var.from_hu_conv[0]
                    if var.from_hu_conv[1] != "":
                        pointer_to_adder += "\t\t\t" + var.from_hu_conv[1] + ";\n"
                else:
                    bindings_instantiator += ", " + first_to_lower(var.arg_name)
            else:
                bindings_instantiator += ", " + first_to_lower(var[1]) + ".instance_idx!"
                super_instantiator += first_to_lower(var[1]) + "_impl, "
                pointer_to_adder += "\t\timpl_holder.held.ptrs_to.push(" + first_to_lower(var[1]) + ");\n"
                impl_constructor_arguments += f", {first_to_lower(var[1])}_impl: {var[0].replace('LDK', '')}Interface"

        super_constructor_statements = ""
        trait_constructor_arguments = ""
        for var in field_var_conversions:
            if isinstance(var, ConvInfo):
                trait_constructor_arguments += ", " + var.arg_name
            else:
                super_constructor_statements += "\t\tconst " + first_to_lower(var[1]) + " = " + var[1] + ".new_impl(" + super_instantiator + ");\n"
                trait_constructor_arguments += ", " + first_to_lower(var[1]) + ".instance_idx!"
                for suparg in var[2]:
                    if isinstance(suparg, ConvInfo):
                        trait_constructor_arguments += ", " + suparg.arg_name
                    else:
                        trait_constructor_arguments += ", " + suparg[1]

        # BUILD INTERFACE METHODS
        out_java_interface = ""
        out_interface_implementation_overrides = ""
        java_methods = []
        for fn_line in field_function_lines:
            java_method_descriptor = ""
            if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
                out_java_interface += "\t/**" + fn_line.docs.replace("\n", "\n\t * ") + "\n\t */\n"
                out_java_interface += "\t" + fn_line.fn_name + "("
                out_interface_implementation_overrides += f"\t\t\t{fn_line.fn_name} ("

                for idx, arg_conv_info in enumerate(fn_line.args_ty):
                    if idx >= 1:
                        out_java_interface += ", "
                        out_interface_implementation_overrides += ", "
                    out_java_interface += f"{arg_conv_info.arg_name}: {arg_conv_info.java_hu_ty}"
                    out_interface_implementation_overrides += f"{arg_conv_info.arg_name}: {arg_conv_info.java_ty}"
                    java_method_descriptor += arg_conv_info.java_fn_ty_arg
                out_java_interface += f"): {fn_line.ret_ty_info.java_hu_ty};\n"
                java_method_descriptor += ")" + fn_line.ret_ty_info.java_fn_ty_arg
                java_methods.append((fn_line.fn_name, java_method_descriptor))

                out_interface_implementation_overrides += f"): {fn_line.ret_ty_info.java_ty} {{\n"

                for arg_info in fn_line.args_ty:
                    if arg_info.to_hu_conv is not None:
                        out_interface_implementation_overrides += "\t\t\t\t" + arg_info.to_hu_conv.replace("\n", "\n\t\t\t\t") + "\n"

                if fn_line.ret_ty_info.java_ty != "void":
                    out_interface_implementation_overrides += "\t\t\t\tconst ret: " + fn_line.ret_ty_info.java_hu_ty + " = arg." + fn_line.fn_name + "("
                else:
                    out_interface_implementation_overrides += f"\t\t\t\targ." + fn_line.fn_name + "("

                for idx, arg_info in enumerate(fn_line.args_ty):
                    if idx != 0:
                        out_interface_implementation_overrides += ", "
                    if arg_info.to_hu_conv_name is not None:
                        out_interface_implementation_overrides += arg_info.to_hu_conv_name
                    else:
                        out_interface_implementation_overrides += arg_info.arg_name

                out_interface_implementation_overrides += ");\n"
                if fn_line.ret_ty_info.java_ty != "void":
                    if fn_line.ret_ty_info.from_hu_conv is not None:
                        out_interface_implementation_overrides += "\t\t\t\t" + f"const result: {fn_line.ret_ty_info.java_ty} = " + fn_line.ret_ty_info.from_hu_conv[0].replace("\n", "\n\t\t\t\t") + ";\n"
                        if fn_line.ret_ty_info.from_hu_conv[1] != "":
                            out_interface_implementation_overrides += "\t\t\t\t" + fn_line.ret_ty_info.from_hu_conv[1].replace("this", "impl_holder.held").replace("\n", "\n\t\t\t\t") + ";\n"
                        #if fn_line.ret_ty_info.rust_obj in result_types:
                        # XXX: We need to handle this in conversion logic so that its cross-language!
                        # Avoid double-free by breaking the result - we should learn to clone these and then we can be safe instead
                        #    out_interface_implementation_overrides = out_interface_implementation_overrides + "\t\t\t\tret.ptr = 0;\n"
                        out_interface_implementation_overrides += "\t\t\t\treturn result;\n"
                    else:
                        out_interface_implementation_overrides += "\t\t\t\treturn ret;\n"
                out_interface_implementation_overrides += f"\t\t\t}},\n"

        formatted_trait_docs = trait_doc_comment.replace("\n", "\n * ")
        out_typescript_human = f"""
{self.hu_struct_file_prefix}

/** An implementation of {struct_name.replace("LDK","")} */
export interface {struct_name.replace("LDK", "")}Interface {{
{out_java_interface}}}

class {struct_name}Holder {{
	held: {struct_name.replace("LDK", "")}|null = null;
}}

/**
 * {formatted_trait_docs}
 */
export class {struct_name.replace("LDK","")} extends CommonBase {{
	/* @internal */
	public bindings_instance: bindings.{struct_name}|null;

	/* @internal */
	public instance_idx?: number;

	/* @internal */
	constructor(_dummy: null, ptr: bigint) {{
		super(ptr, bindings.{struct_name.replace("LDK","")}_free);
		this.bindings_instance = null;
	}}

	/** Creates a new instance of {struct_name.replace("LDK","")} from a given implementation */
	public static new_impl(arg: {struct_name.replace("LDK", "")}Interface{impl_constructor_arguments}): {struct_name.replace("LDK", "")} {{
		const impl_holder: {struct_name}Holder = new {struct_name}Holder();
		let structImplementation = {{
{out_interface_implementation_overrides}		}} as bindings.{struct_name};
{super_constructor_statements}		const ptr_idx: [bigint, number] = bindings.{struct_name}_new(structImplementation{bindings_instantiator});

		impl_holder.held = new {struct_name.replace("LDK", "")}(null, ptr_idx[0]);
		impl_holder.held.instance_idx = ptr_idx[1];
		impl_holder.held.bindings_instance = structImplementation;
{pointer_to_adder}		return impl_holder.held!;
	}}

"""
        self.obj_defined([struct_name.replace("LDK", ""), struct_name.replace("LDK", "") + "Interface"], "structs")

        out_typescript_bindings += "/* @internal */\nexport interface " + struct_name + " {\n"
        java_meths = []
        for fn_line in field_function_lines:
            if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
                out_typescript_bindings += f"\t{fn_line.fn_name} ("

                for idx, arg_conv_info in enumerate(fn_line.args_ty):
                    if idx >= 1:
                        out_typescript_bindings = out_typescript_bindings + ", "
                    out_typescript_bindings += f"{arg_conv_info.arg_name}: {arg_conv_info.java_ty}"

                out_typescript_bindings += f"): {fn_line.ret_ty_info.java_ty};\n"

        out_typescript_bindings += "}\n\n"

        c_call_extra_args = ""
        out_typescript_bindings += f"/* @internal */\nexport function {struct_name}_new(impl: {struct_name}"
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                out_typescript_bindings += f", {var.arg_name}: {var.java_ty}"
                c_call_extra_args += f", {var.arg_name}"
            else:
                out_typescript_bindings += f", {var[1]}: number"
                c_call_extra_args += f", {var[1]}"


        out_typescript_bindings += f"""): [bigint, number] {{
	if(!isWasmInitialized) {{
		throw new Error("initializeWasm() must be awaited first!");
	}}
	var new_obj_idx = js_objs.length;
	for (var i = 0; i < js_objs.length; i++) {{
		if (js_objs[i] == null || js_objs[i] == undefined) {{ new_obj_idx = i; break; }}
	}}
	js_objs[i] = new WeakRef(impl);
	return [wasm.TS_{struct_name}_new(i{c_call_extra_args}), i];
}}
"""

        # Now that we've written out our java code (and created java_meths), generate C
        out_c = "typedef struct " + struct_name + "_JCalls {\n"
        out_c += "\tatomic_size_t refcnt;\n"
        out_c += "\tuint32_t instance_ptr;\n"
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                # We're a regular ol' field
                pass
            else:
                # We're a supertrait
                out_c = out_c + "\t" + var[0] + "_JCalls* " + var[1] + ";\n"
        out_c = out_c + "} " + struct_name + "_JCalls;\n"

        for fn_line in field_function_lines:
            if fn_line.fn_name == "free":
                out_c = out_c + "static void " + struct_name + "_JCalls_free(void* this_arg) {\n"
                out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"
                out_c = out_c + "\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n"
                out_c = out_c + "\t\tFREE(j_calls);\n"
                out_c = out_c + "\t}\n}\n"

        for idx, fn_line in enumerate(field_function_lines):
            if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
                assert fn_line.ret_ty_info.ty_info.get_full_rust_ty()[1] == ""
                out_c = out_c + fn_line.ret_ty_info.ty_info.get_full_rust_ty()[0] + " " + fn_line.fn_name + "_" + struct_name + "_jcall("
                if fn_line.self_is_const:
                    out_c = out_c + "const void* this_arg"
                else:
                    out_c = out_c + "void* this_arg"

                for idx, arg in enumerate(fn_line.args_ty):
                    out_c = out_c + ", " + arg.ty_info.get_full_rust_ty()[0] + " " + arg.arg_name + arg.ty_info.get_full_rust_ty()[1]

                out_c = out_c + ") {\n"
                out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n"

                for arg_info in fn_line.args_ty:
                    if arg_info.ret_conv is not None:
                        out_c = out_c + "\t" + arg_info.ret_conv[0].replace('\n', '\n\t')
                        out_c = out_c + arg_info.arg_name
                        out_c = out_c + arg_info.ret_conv[1].replace('\n', '\n\t') + "\n"

                fn_suffix = ""
                assert len(fn_line.args_ty) < 7
                for arg_info in fn_line.args_ty:
                    if arg_info.c_ty == "uint64_t" or arg_info.c_ty == "int64_t":
                        fn_suffix += "b"
                    else:
                        fn_suffix += "u"
                for i in range(0, 6 - len(fn_line.args_ty)):
                    fn_suffix += "u"
                if fn_line.ret_ty_info.c_ty.endswith("Array"):
                    out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (" + fn_line.ret_ty_info.c_ty + ")"
                    out_c += "js_invoke_function_" + fn_suffix + "(j_calls->instance_ptr, " + str(self.function_ptr_counter)
                elif fn_line.ret_ty_info.java_ty == "void":
                    out_c = out_c + "\tjs_invoke_function_" + fn_suffix + "(j_calls->instance_ptr, " + str(self.function_ptr_counter)
                elif fn_line.ret_ty_info.java_hu_ty == "string":
                    out_c += "\tjstring ret = (jstring)js_invoke_function_" + fn_suffix + "(j_calls->instance_ptr, " + str(self.function_ptr_counter)
                elif fn_line.ret_ty_info.arg_conv is None:
                    out_c += "\treturn js_invoke_function_" + fn_suffix + "(j_calls->instance_ptr, " + str(self.function_ptr_counter)
                else:
                    out_c += "\tuint64_t ret = js_invoke_function_" + fn_suffix + "(j_calls->instance_ptr, " + str(self.function_ptr_counter)

                self.function_ptrs[self.function_ptr_counter] = (struct_name, fn_line.fn_name)
                self.function_ptr_counter += 1

                for idx, arg_info in enumerate(fn_line.args_ty):
                    if arg_info.ret_conv is not None:
                        if arg_info.c_ty.endswith("Array"):
                            out_c += ", (uint32_t)" + arg_info.ret_conv_name
                        else:
                            out_c += ", " + arg_info.ret_conv_name
                    else:
                        assert False # TODO: Would we need some conversion here?
                        out_c += ", (uint32_t)" + arg_info.arg_name
                for i in range(0, 6 - len(fn_line.args_ty)):
                    out_c += ", 0"
                out_c = out_c + ");\n"
                if fn_line.ret_ty_info.arg_conv is not None:
                    out_c = out_c + "\t" + fn_line.ret_ty_info.arg_conv.replace("\n", "\n\t") + "\n\treturn " + fn_line.ret_ty_info.arg_conv_name + ";\n"

                out_c = out_c + "}\n"

        # Write out a clone function whether we need one or not, as we use them in moving to rust
        out_c = out_c + "static void " + struct_name + "_JCalls_cloned(" + struct_name + "* new_obj) {\n"
        out_c = out_c + "\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) new_obj->this_arg;\n"
        out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n"
        for var in field_var_conversions:
            if not isinstance(var, ConvInfo):
                out_c = out_c + "\tatomic_fetch_add_explicit(&j_calls->" + var[1] + "->refcnt, 1, memory_order_release);\n"
        out_c = out_c + "}\n"

        out_c = out_c + "static inline " + struct_name + " " + struct_name + "_init (JSValue o"
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                out_c = out_c + ", " + var.c_ty + " " + var.arg_name
            else:
                out_c = out_c + ", JSValue " + var[1]
        out_c = out_c + ") {\n"

        out_c = out_c + "\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n"
        out_c = out_c + "\tatomic_init(&calls->refcnt, 1);\n"
        out_c = out_c + "\tcalls->instance_ptr = o;\n"

        for (fn_name, java_meth_descr) in java_meths:
            if fn_name != "free" and fn_name != "cloned":
                out_c = out_c + "\tcalls->" + fn_name + "_meth = (*env)->GetMethodID(env, c, \"" + fn_name + "\", \"" + java_meth_descr + "\");\n"
                out_c = out_c + "\tCHECK(calls->" + fn_name + "_meth != NULL);\n"

        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo) and var.arg_conv is not None:
                out_c = out_c + "\n\t" + var.arg_conv.replace("\n", "\n\t") +"\n"
        out_c = out_c + "\n\t" + struct_name + " ret = {\n"
        out_c = out_c + "\t\t.this_arg = (void*) calls,\n"
        for fn_line in field_function_lines:
            if fn_line.fn_name != "free" and fn_line.fn_name != "cloned":
                out_c = out_c + "\t\t." + fn_line.fn_name + " = " + fn_line.fn_name + "_" + struct_name + "_jcall,\n"
            elif fn_line.fn_name == "free":
                out_c = out_c + "\t\t.free = " + struct_name + "_JCalls_free,\n"
            else:
                out_c = out_c + "\t\t.cloned = " + struct_name + "_JCalls_cloned,\n"
        for var in field_var_conversions:
            if isinstance(var, ConvInfo):
                if var.arg_conv_name is not None:
                    out_c = out_c + "\t\t." + var.arg_name + " = " + var.arg_conv_name + ",\n"
                    out_c = out_c + "\t\t.set_" + var.arg_name + " = NULL,\n"
                else:
                    out_c = out_c + "\t\t." + var.var_name + " = " + var.var_name + ",\n"
                    out_c = out_c + "\t\t.set_" + var.var_name + " = NULL,\n"
            else:
                out_c += "\t\t." + var[1] + " = " + var[0] + "_init(" + var[1]
                for suparg in var[2]:
                    if isinstance(suparg, ConvInfo):
                        out_c += ", " + suparg.arg_name
                    else:
                        out_c += ", " + suparg[1]
                out_c += "),\n"
        out_c = out_c + "\t};\n"
        for var in flattened_field_var_conversions:
            if not isinstance(var, ConvInfo):
                out_c = out_c + "\tcalls->" + var[1] + " = ret." + var[1] + ".this_arg;\n"
        out_c = out_c + "\treturn ret;\n"
        out_c = out_c + "}\n"

        out_c = out_c + self.c_fn_ty_pfx + "uint64_t " + self.c_fn_name_define_pfx(struct_name + "_new", True) + "JSValue o"
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                out_c = out_c + ", " + var.c_ty + " " + var.arg_name
            else:
                out_c = out_c + ", JSValue " + var[1]
        out_c = out_c + ") {\n"
        out_c = out_c + "\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n"
        out_c = out_c + "\t*res_ptr = " + struct_name + "_init(o"
        for var in flattened_field_var_conversions:
            if isinstance(var, ConvInfo):
                out_c = out_c + ", " + var.arg_name
            else:
                out_c = out_c + ", " + var[1]
        out_c = out_c + ");\n"
        out_c = out_c + "\treturn tag_ptr(res_ptr, true);\n"
        out_c = out_c + "}\n"

        return (out_typescript_bindings, out_typescript_human, out_c)

    def trait_struct_inc_refcnt(self, ty_info):
        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_cloned(&" + ty_info.var_name + "_conv);\n}"
        return base_conv

    def map_complex_enum(self, struct_name, variant_list, camel_to_snake, enum_doc_comment):
        bindings_type = struct_name.replace("LDK", "")
        java_hu_type = struct_name.replace("LDK", "").replace("COption", "Option")

        out_java_enum = ""
        out_java = ""
        out_c = ""

        out_java_enum += (self.hu_struct_file_prefix)

        java_hu_class = "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
        java_hu_class += "export class " + java_hu_type + " extends CommonBase {\n"
        java_hu_class += "\tprotected constructor(_dummy: null, ptr: bigint) { super(ptr, bindings." + bindings_type + "_free); }\n"
        java_hu_class += "\t/* @internal */\n"
        java_hu_class += f"\tpublic static constr_from_ptr(ptr: bigint): {java_hu_type} {{\n"
        java_hu_class += f"\t\tconst raw_ty: number = bindings." + struct_name + "_ty_from_ptr(ptr);\n"
        out_c += self.c_fn_ty_pfx + "uint32_t" + self.c_fn_name_define_pfx(struct_name + "_ty_from_ptr", True) + self.ptr_c_ty + " ptr) {\n"
        out_c += "\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n"
        out_c += "\tswitch(obj->tag) {\n"
        java_hu_class += "\t\tswitch (raw_ty) {\n"
        java_hu_subclasses = ""

        out_java += "/* @internal */\nexport class " + struct_name + " {\n"
        out_java += "\tprotected constructor() {}\n"
        var_idx = 0
        for var in variant_list:
            java_hu_subclasses += "/** A " + java_hu_type + " of type " + var.var_name + " */\n"
            java_hu_subclasses += "export class " + java_hu_type + "_" + var.var_name + " extends " + java_hu_type + " {\n"
            java_hu_class += f"\t\t\tcase {var_idx}: "
            java_hu_class += "return new " + java_hu_type + "_" + var.var_name + "(ptr);\n"
            out_c += f"\t\tcase {struct_name}_{var.var_name}: return {var_idx};\n"
            hu_conv_body = ""
            for idx, (field_ty, field_docs) in enumerate(var.fields):
                if field_docs is not None:
                    java_hu_subclasses += "\t/**\n\t * " + field_docs.replace("\n", "\n\t * ") + "\n\t */\n"
                java_hu_subclasses += "\tpublic " + field_ty.arg_name + f": {field_ty.java_hu_ty};\n"
                if field_ty.to_hu_conv is not None:
                    hu_conv_body += f"\t\tconst {field_ty.arg_name}: {field_ty.java_ty} = bindings.{struct_name}_{var.var_name}_get_{field_ty.arg_name}(ptr);\n"
                    hu_conv_body += f"\t\t" + field_ty.to_hu_conv.replace("\n", "\n\t\t\t") + "\n"
                    hu_conv_body += f"\t\tthis." + field_ty.arg_name + " = " + field_ty.to_hu_conv_name + ";\n"
                else:
                    hu_conv_body += f"\t\tthis.{field_ty.arg_name} = bindings.{struct_name}_{var.var_name}_get_{field_ty.arg_name}(ptr);\n"
            java_hu_subclasses += "\t/* @internal */\n"
            java_hu_subclasses += "\tpublic constructor(ptr: bigint) {\n\t\tsuper(null, ptr);\n"
            java_hu_subclasses = java_hu_subclasses + hu_conv_body
            java_hu_subclasses = java_hu_subclasses + "\t}\n}\n"
            var_idx += 1
        out_java += "}\n"
        java_hu_class += "\t\t\tdefault:\n\t\t\t\tthrow new Error('oops, this should be unreachable'); // Unreachable without extending the (internal) bindings interface\n\t\t}\n\t}\n\n"
        out_java += self.fn_call_body(struct_name + "_ty_from_ptr", "uint32_t", "number", "ptr: bigint", "ptr")
        out_c += ("\t\tdefault: abort();\n")
        out_c += ("\t}\n}\n")

        for var in variant_list:
            for idx, (field_map, _) in enumerate(var.fields):
                fn_name = f"{struct_name}_{var.var_name}_get_{field_map.arg_name}"
                out_c += self.c_fn_ty_pfx + field_map.c_ty + self.c_fn_name_define_pfx(fn_name, True) + self.ptr_c_ty + " ptr) {\n"
                out_c += "\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n"
                out_c += f"\tassert(obj->tag == {struct_name}_{var.var_name});\n"
                if field_map.ret_conv is not None:
                    out_c += ("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t"))
                    if var.tuple_variant:
                        out_c += "obj->" + camel_to_snake(var.var_name)
                    else:
                        out_c += "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name
                    out_c += (field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
                    out_c += "\treturn " + field_map.ret_conv_name + ";\n"
                else:
                    if var.tuple_variant:
                        out_c += "\treturn " + "obj->" + camel_to_snake(var.var_name) + ";\n"
                    else:
                        out_c += "\treturn " + "obj->" + camel_to_snake(var.var_name) + "." + field_map.arg_name + ";\n"
                out_c += "}\n"
                out_java += self.fn_call_body(fn_name, field_map.c_ty, field_map.java_ty, "ptr: bigint", "ptr")
        out_java_enum += java_hu_class
        self.struct_file_suffixes[java_hu_type] = java_hu_subclasses
        self.obj_defined([java_hu_type], "structs")
        return (out_java, out_java_enum, out_c)

    def map_opaque_struct(self, struct_name, struct_doc_comment):
        method_header = ""

        hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDKC4Tuple", "FourTuple").replace("LDK", "")
        out_opaque_struct_human = f"{self.hu_struct_file_prefix}"
        extra_docs = ""
        extra_body = ""
        if struct_name.startswith("LDKLocked") or struct_name.startswith("LDKReadOnly"):
            extra_docs = "\n\tThis type represents a lock and MUST BE MANUALLY FREE'd!" # XXX: There's a thing for this
            constructor_body = 'super(ptr, () => { throw new Error("Locks must be manually freed with free()"); });'
            extra_body = f"""
	/** Releases this lock */
	public free() {{
		bindings.{struct_name.replace("LDK","")}_free(this.ptr);
		CommonBase.set_null_skip_free(this);
	}}"""
        formatted_doc_comment = struct_doc_comment.replace("\n", "\n\t")
        out_opaque_struct_human += f"""
class {hu_name} {{
	\"\"\"{extra_docs}
	{formatted_doc_comment}
	\"\"\"
	def __init__(_dummy: null, ptr: int):
		self.ptr = ptr

	def __del__(self):
		bindings.{struct_name.replace("LDK","")}_free(self.ptr)
{extra_body}

"""
        self.obj_defined([hu_name], "structs")
        return out_opaque_struct_human

    def map_tuple(self, struct_name):
        return self.map_opaque_struct(struct_name, "A Tuple")

    def map_result(self, struct_name, res_map, err_map):
        human_ty = struct_name.replace("LDKCResult", "Result")

        suffixes = f"export class {human_ty}_OK extends {human_ty} {{\n"
        if res_map.java_hu_ty != "void":
            suffixes += "\tpublic res: " + res_map.java_hu_ty + ";\n"
        suffixes += f"""
	/* @internal */
	public constructor(_dummy: null, ptr: bigint) {{
		super(_dummy, ptr);
"""
        if res_map.java_hu_ty == "void":
            pass
        elif res_map.to_hu_conv is not None:
            suffixes += "\t\tconst res: " + res_map.java_ty + " = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
            suffixes += "\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t")
            suffixes += "\n\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
        else:
            suffixes += "\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
        suffixes += "\t}\n}\n"

        suffixes += f"export class {human_ty}_Err extends {human_ty} {{\n"
        if err_map.java_hu_ty != "void":
            suffixes += "\tpublic err: " + err_map.java_hu_ty + ";\n"
        suffixes += f"""
	/* @internal */
	public constructor(_dummy: null, ptr: bigint) {{
		super(_dummy, ptr);
"""
        if err_map.java_hu_ty == "void":
            pass
        elif err_map.to_hu_conv is not None:
            suffixes += "\t\tconst err: " + err_map.java_ty + " = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
            suffixes += "\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t")
            suffixes += "\n\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
        else:
            suffixes += "\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
        suffixes += "\t}\n}"

        self.struct_file_suffixes[human_ty] = suffixes
        self.obj_defined([human_ty], "structs")

        return f"""{self.hu_struct_file_prefix}

export class {human_ty} extends CommonBase {{
	protected constructor(_dummy: null, ptr: bigint) {{
		super(ptr, bindings.{struct_name.replace("LDK","")}_free);
	}}
	/* @internal */
	public static constr_from_ptr(ptr: bigint): {human_ty} {{
		if (bindings.{struct_name.replace("LDK", "")}_is_ok(ptr)) {{
			return new {human_ty}_OK(null, ptr);
		}} else {{
			return new {human_ty}_Err(null, ptr);
		}}
	}}
"""

    def fn_call_body(self, method_name, return_c_ty, return_java_ty, method_argument_string, native_call_argument_string):
        has_return_value = return_c_ty != 'void'
        return_statement = 'return nativeResponseValue;'
        if not has_return_value:
            return_statement = '// debug statements here'

        return f"""/* @internal */
export function {method_name}({method_argument_string}): {return_java_ty} {{
	if(!isWasmInitialized) {{
		throw new Error("initializeWasm() must be awaited first!");
	}}
	const nativeResponseValue = wasm.TS_{method_name}({native_call_argument_string});
	{return_statement}
}}
"""
    def map_function(self, argument_types, c_call_string, method_name, meth_n, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
        out_java = ""
        out_c = ""
        out_java_struct = None

        out_java += ("\t")
        out_c += (self.c_fn_ty_pfx)
        out_c += (return_type_info.c_ty)
        out_java += (return_type_info.java_ty)
        if return_type_info.ret_conv is not None:
            ret_conv_pfx, ret_conv_sfx = return_type_info.ret_conv
        out_java += (" " + method_name + "(")
        out_c += (" "  + self.c_fn_name_define_pfx(method_name, True))

        method_argument_string = ""
        native_call_argument_string = ""
        for idx, arg_conv_info in enumerate(argument_types):
            if idx != 0:
                method_argument_string += (", ")
                native_call_argument_string += ', '
                out_c += (", ")
            if arg_conv_info.c_ty != "void":
                out_c += (arg_conv_info.c_ty + " " + arg_conv_info.arg_name)
                method_argument_string += f"{arg_conv_info.arg_name}: {arg_conv_info.java_ty}"
                native_call_argument_string += arg_conv_info.arg_name
        out_java = self.fn_call_body(method_name, return_type_info.c_ty, return_type_info.java_ty, method_argument_string, native_call_argument_string)

        out_java_struct = ""
        if doc_comment is not None:
            out_java_struct = "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"

        if not args_known:
            out_java_struct += ("\t// Skipped " + method_name + "\n")
        else:
            if not takes_self:
                out_java_struct += (
                        "\tpublic static constructor_" + meth_n + "(")
            else:
                out_java_struct += ("\tpublic " + meth_n + "(")
            for idx, arg in enumerate(argument_types):
                if idx != 0:
                    if not takes_self or idx > 1:
                        out_java_struct += (", ")
                elif takes_self:
                    continue
                if arg.java_ty != "void":
                    if arg.arg_name in default_constructor_args:
                        for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
                            if explode_idx != 0:
                                out_java_struct += (", ")
                            out_java_struct += arg.arg_name + "_" + explode_arg.arg_name + ": " + explode_arg.java_hu_ty
                    else:
                        out_java_struct += arg.arg_name + ": " + arg.java_hu_ty
                        if arg.nullable:
                            out_java_struct += "|null"

        out_c += (") {\n")
        if out_java_struct is not None:
            out_java_struct += "): " + return_type_info.java_hu_ty + " {\n"
        for info in argument_types:
            if info.arg_conv is not None:
                out_c += ("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
        if return_type_info.ret_conv is not None:
            out_c += ("\t" + ret_conv_pfx.replace('\n', '\n\t'))
        elif return_type_info.c_ty != "void":
            out_c += ("\t" + return_type_info.c_ty + " ret_val = ")
        else:
            out_c += ("\t")
        if c_call_string is None:
            out_c += (method_name + "(")
        else:
            out_c += (c_call_string)
        for idx, info in enumerate(argument_types):
            if info.arg_conv_name is not None:
                if idx != 0:
                    out_c += (", ")
                elif c_call_string is not None:
                    continue
                out_c += (info.arg_conv_name)
        out_c += (")")
        if return_type_info.ret_conv is not None:
            out_c += (ret_conv_sfx.replace('\n', '\n\t'))
        else:
            out_c += (";")
        for info in argument_types:
            if info.arg_conv_cleanup is not None:
                out_c += ("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
        if return_type_info.ret_conv is not None:
            out_c += ("\n\treturn " + return_type_info.ret_conv_name + ";")
        elif return_type_info.c_ty != "void":
            out_c += ("\n\treturn ret_val;")
        out_c += ("\n}\n\n")

        if args_known:
            out_java_struct += ("\t\t")
            if return_type_info.java_ty != "void":
                out_java_struct += "const ret: " + return_type_info.java_ty + " = "
            out_java_struct += ("bindings." + method_name + "(")
            for idx, info in enumerate(argument_types):
                if idx != 0:
                    out_java_struct += (", ")
                if idx == 0 and takes_self:
                    out_java_struct += ("this.ptr")
                elif info.arg_name in default_constructor_args:
                    out_java_struct += ("bindings." + info.java_hu_ty + "_new(")
                    for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
                        if explode_idx != 0:
                            out_java_struct += (", ")
                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
                        if explode_arg.from_hu_conv is not None:
                            out_java_struct += (
                                explode_arg.from_hu_conv[0].replace(explode_arg.arg_name, expl_arg_name))
                        else:
                            out_java_struct += (expl_arg_name)
                    out_java_struct += (")")
                elif info.from_hu_conv is not None:
                    out_java_struct += (info.from_hu_conv[0])
                else:
                    out_java_struct += (info.arg_name)
            out_java_struct += (");\n")
            if return_type_info.to_hu_conv is not None:
                if not takes_self:
                    out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t").replace("this",
                                                                                                             return_type_info.to_hu_conv_name) + "\n")
                else:
                    out_java_struct += ("\t\t" + return_type_info.to_hu_conv.replace("\n", "\n\t\t") + "\n")

            for idx, info in enumerate(argument_types):
                if idx == 0 and takes_self:
                    pass
                elif info.arg_name in default_constructor_args:
                    for explode_arg in default_constructor_args[info.arg_name]:
                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
                        if explode_arg.from_hu_conv is not None and return_type_info.to_hu_conv_name:
                            out_java_struct += ("\t\t" + explode_arg.from_hu_conv[1].replace(explode_arg.arg_name,
                                                                                             expl_arg_name).replace(
                                "this", return_type_info.to_hu_conv_name) + ";\n")
                elif info.from_hu_conv is not None and info.from_hu_conv[1] != "":
                    if not takes_self and return_type_info.to_hu_conv_name is not None:
                        out_java_struct += (
                                "\t\t" + info.from_hu_conv[1].replace("this", return_type_info.to_hu_conv_name).replace("\n", "\n\t\t") + ";\n")
                    else:
                        out_java_struct += ("\t\t" + info.from_hu_conv[1].replace("\n", "\n\t\t") + ";\n")

            if return_type_info.to_hu_conv_name is not None:
                out_java_struct += ("\t\treturn " + return_type_info.to_hu_conv_name + ";\n")
            elif return_type_info.java_ty != "void" and return_type_info.rust_obj != "LDK" + struct_meth:
                out_java_struct += ("\t\treturn ret;\n")
            out_java_struct += ("\t}\n\n")

        return (out_java, out_c, out_java_struct)

    def cleanup(self):
        for struct in self.struct_file_suffixes:
            with open(self.outdir + "/structs/" + struct + self.file_ext, "a") as src:
                src.write(self.struct_file_suffixes[struct])

        with open(self.outdir + "/bindings.py", "a") as bindings:
            bindings.write("""

js_invoke = function(obj_ptr: number, fn_id: number, arg1: bigint|number, arg2: bigint|number, arg3: bigint|number, arg4: bigint|number, arg5: bigint|number, arg6: bigint|number, arg7: bigint|number, arg8: bigint|number, arg9: bigint|number, arg10: bigint|number) {
	const weak: WeakRef<object>|undefined = js_objs[obj_ptr];
	if (weak == null || weak == undefined) {
		console.error("Got function call on unknown/free'd JS object!");
		throw new Error("Got function call on unknown/free'd JS object!");
	}
	const obj = weak.deref();
	if (obj == null || obj == undefined) {
		console.error("Got function call on GC'd JS object!");
		throw new Error("Got function call on GC'd JS object!");
	}
	var fn;
""")
            bindings.write("\tswitch (fn_id) {\n")
            for f in self.function_ptrs:
                bindings.write(f"\t\tcase {str(f)}: fn = Object.getOwnPropertyDescriptor(obj, \"{self.function_ptrs[f][1]}\"); break;\n")

            bindings.write("""\t\tdefault:
			console.error("Got unknown function call from C!");
			throw new Error("Got unknown function call from C!");
	}
	if (fn == null || fn == undefined) {
		console.error("Got function call on incorrect JS object!");
		throw new Error("Got function call on incorrect JS object!");
	}
	const ret = fn.value.bind(obj)(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10);
	if (ret === undefined || ret === null) return BigInt(0);
	return BigInt(ret);
}""")