[bun:ffi] Support `i64` and `u64`

8 files changed, 132 insertions, 43 deletions

diff --git a/src/javascript/jsc/api/FFI.h b/src/javascript/jsc/api/FFI.h
index 42bc03fc8..69af59dc6 100644
--- a/src/javascript/jsc/api/FFI.h
+++ b/src/javascript/jsc/api/FFI.h
@@ -37,28 +37,6 @@ typedef _Bool bool;
 #define true 1
 #define false 0
 
-#ifdef USES_FLOAT
-// https://git.musl-libc.org/cgit/musl/tree/src/math/trunc.c
-double trunc(double x);
-double trunc(double x)
-{
-	union {double f; uint64_t i;} u = {x};
-	int e = (int)(u.i >> 52 & 0x7ff) - 0x3ff + 12;
-	uint64_t m;
-
-	if (e >= 52 + 12)
-		return x;
-	if (e < 12)
-		e = 1;
-	m = -1ULL >> e;
-	if ((u.i & m) == 0)
-		return x;
-	x + 0x1p120f;
-	u.i &= ~m;
-	return u.f;
-}
-#endif
-
 
 // This value is 2^49, used to encode doubles such that the encoded value will
 // begin with a 15-bit pattern within the range 0x0002..0xFFFC.
@@ -81,7 +59,6 @@ typedef  void* JSCell;
 typedef union EncodedJSValue {
   int64_t asInt64;
 #if USE_JSVALUE32_64
-  double asDouble;
 #elif USE_JSVALUE64
   JSCell *ptr;
 #endif
@@ -116,6 +93,11 @@ JSContext cachedJSContext;
 void* cachedCallbackFunction;
 #endif
 
+uint64_t JSVALUE_TO_UINT64(void* globalObject, EncodedJSValue value);
+int64_t JSVALUE_TO_INT64(EncodedJSValue value);
+
+EncodedJSValue UINT64_TO_JSVALUE(void* globalObject, uint64_t val);
+EncodedJSValue INT64_TO_JSVALUE(void* globalObject, int64_t val);
 
 static EncodedJSValue INT32_TO_JSVALUE(int32_t val) __attribute__((__always_inline__));
 static EncodedJSValue DOUBLE_TO_JSVALUE(double val) __attribute__((__always_inline__));
@@ -183,11 +165,9 @@ static bool JSVALUE_TO_BOOL(EncodedJSValue val) {
 }
 
 #define arg(i) ((EncodedJSValue*)args)[i]
+#ifndef IS_CALLBACK
 void* JSFunctionCall(void* globalObject, void* callFrame);
-// int64_t JSFunctionCall(void* globalObject, void* callFrame) {
-//   EncodedJSValue* args = (EncodedJSValue*)((unsigned char*)callFrame + Bun_FFI_PointerOffsetToArgumentsList);
-// }
-
+#endif
 
 
 // --- Generated Code ---
diff --git a/src/javascript/jsc/api/ffi.zig b/src/javascript/jsc/api/ffi.zig
index b3be0062f..702d0d6d6 100644
--- a/src/javascript/jsc/api/ffi.zig
+++ b/src/javascript/jsc/api/ffi.zig
@@ -591,6 +591,21 @@ pub const FFI = struct {
 
         extern fn pthread_jit_write_protect_np(enable: bool) callconv(.C) void;
 
+        const MyFunctionSStructWorkAround = struct {
+            JSVALUE_TO_INT64: fn (JSValue0: JSC.JSValue) callconv(.C) i64,
+            JSVALUE_TO_UINT64: fn (JSValue0: JSC.JSValue) callconv(.C) u64,
+            INT64_TO_JSVALUE: fn (arg0: [*c]JSC.JSGlobalObject, arg1: i64) callconv(.C) JSC.JSValue,
+            UINT64_TO_JSVALUE: fn (arg0: [*c]JSC.JSGlobalObject, arg1: u64) callconv(.C) JSC.JSValue,
+        };
+        const headers = @import("../bindings/headers.zig");
+
+        var workaround: MyFunctionSStructWorkAround = .{
+            .JSVALUE_TO_INT64 = headers.JSC__JSValue__toInt64,
+            .JSVALUE_TO_UINT64 = headers.JSC__JSValue__toUInt64NoTruncate,
+            .INT64_TO_JSVALUE = headers.JSC__JSValue__fromInt64NoTruncate,
+            .UINT64_TO_JSVALUE = headers.JSC__JSValue__fromUInt64NoTruncate,
+        };
+
         const tcc_options = "-std=c11 -nostdlib -Wl,--export-all-symbols";
 
         pub fn compile(
@@ -625,6 +640,7 @@ pub const FFI = struct {
                 "Bun_FFI_PointerOffsetToArgumentsList",
                 std.fmt.bufPrintZ(&symbol_buf, "{d}", .{Sizes.Bun_FFI_PointerOffsetToArgumentsList}) catch unreachable,
             );
+
             // TCC.tcc_define_symbol(
             //     state,
             //     "Bun_FFI_PointerOffsetToArgumentsCount",
@@ -647,7 +663,31 @@ pub const FFI = struct {
             }
             CompilerRT.inject(state);
             _ = TCC.tcc_add_symbol(state, this.base_name, this.symbol_from_dynamic_library.?);
+            _ = TCC.tcc_add_symbol(
+                state,
+                "JSVALUE_TO_INT64",
+                workaround.JSVALUE_TO_INT64,
+            );
+            _ = TCC.tcc_add_symbol(
+                state,
+                "JSVALUE_TO_UINT64",
+                workaround.JSVALUE_TO_UINT64,
+            );
+            std.mem.doNotOptimizeAway(headers.JSC__JSValue__toUInt64NoTruncate);
+            std.mem.doNotOptimizeAway(headers.JSC__JSValue__toInt64);
+            std.mem.doNotOptimizeAway(headers.JSC__JSValue__fromInt64NoTruncate);
+            std.mem.doNotOptimizeAway(headers.JSC__JSValue__fromUInt64NoTruncate);
 
+            _ = TCC.tcc_add_symbol(
+                state,
+                "INT64_TO_JSVALUE",
+                workaround.INT64_TO_JSVALUE,
+            );
+            _ = TCC.tcc_add_symbol(
+                state,
+                "UINT64_TO_JSVALUE",
+                workaround.UINT64_TO_JSVALUE,
+            );
             if (this.step == .failed) {
                 return;
             }
@@ -1131,8 +1171,12 @@ pub const FFI = struct {
                     .char, .int8_t, .uint8_t, .int16_t, .uint16_t, .int32_t, .uint32_t => {
                         try writer.print("JSVALUE_TO_INT32({s})", .{self.symbol});
                     },
-                    .int64_t => {},
-                    .uint64_t => {},
+                    .int64_t => {
+                        try writer.print("JSVALUE_TO_INT64({s})", .{self.symbol});
+                    },
+                    .uint64_t => {
+                        try writer.print("JSVALUE_TO_UINT64(globalObject, {s})", .{self.symbol});
+                    },
                     .cstring, .ptr => {
                         try writer.print("JSVALUE_TO_PTR({s})", .{self.symbol});
                     },
@@ -1159,8 +1203,12 @@ pub const FFI = struct {
                     .char, .int8_t, .uint8_t, .int16_t, .uint16_t, .int32_t, .uint32_t => {
                         try writer.print("INT32_TO_JSVALUE({s})", .{self.symbol});
                     },
-                    .int64_t => {},
-                    .uint64_t => {},
+                    .int64_t => {
+                        try writer.print("INT64_TO_JSVALUE(globalObject, {s})", .{self.symbol});
+                    },
+                    .uint64_t => {
+                        try writer.print("UINT64_TO_JSVALUE(globalObject, {s})", .{self.symbol});
+                    },
                     .cstring, .ptr => {
                         try writer.print("PTR_TO_JSVALUE({s})", .{self.symbol});
                     },
diff --git a/src/javascript/jsc/bindings/bindings.cpp b/src/javascript/jsc/bindings/bindings.cpp
index 16900c191..a5a51adbc 100644
--- a/src/javascript/jsc/bindings/bindings.cpp
+++ b/src/javascript/jsc/bindings/bindings.cpp
@@ -1898,6 +1898,37 @@ int64_t JSC__JSValue__toInt64(JSC__JSValue val)
     return _val.asAnyInt();
 }
 
+JSC__JSValue JSC__JSValue__fromInt64NoTruncate(JSC__JSGlobalObject* globalObject, int64_t val)
+{
+    return JSC::JSValue::encode(JSC::JSValue(JSC::JSBigInt::createFrom(globalObject, val)));
+}
+
+JSC__JSValue JSC__JSValue__fromUInt64NoTruncate(JSC__JSGlobalObject* globalObject, uint64_t val)
+{
+    return JSC::JSValue::encode(JSC::JSValue(JSC::JSBigInt::createFrom(globalObject, val)));
+}
+
+uint64_t JSC__JSValue__toUInt64NoTruncate(JSC__JSValue val)
+{
+    JSC::JSValue _val = JSC::JSValue::decode(val);
+
+    int64_t result = JSC::tryConvertToInt52(_val.asDouble());
+    if (result != JSC::JSValue::notInt52) {
+        if (result < 0)
+            return 0;
+
+        return static_cast<uint64_t>(result);
+    }
+
+    if (_val.isHeapBigInt()) {
+
+        if (auto* heapBigInt = _val.asHeapBigInt()) {
+            return heapBigInt->toBigUInt64(heapBigInt);
+        }
+    }
+    return static_cast<uint64_t>(_val.asAnyInt());
+}
+
 JSC__JSValue JSC__JSValue__createObject2(JSC__JSGlobalObject* globalObject, const ZigString* arg1,
     const ZigString* arg2, JSC__JSValue JSValue3,
     JSC__JSValue JSValue4)
diff --git a/src/javascript/jsc/bindings/bindings.zig b/src/javascript/jsc/bindings/bindings.zig
index dbcfabf7b..5c1d2c0cc 100644
--- a/src/javascript/jsc/bindings/bindings.zig
+++ b/src/javascript/jsc/bindings/bindings.zig
@@ -2567,6 +2567,18 @@ pub const JSValue = enum(u64) {
         return null;
     }
 
+    pub fn fromInt64NoTruncate(globalObject: *JSGlobalObject, i: i64) JSValue {
+        return cppFn("fromInt64NoTruncate", .{ globalObject, i });
+    }
+    pub fn fromUInt64NoTruncate(globalObject: *JSGlobalObject, i: u64) JSValue {
+        return cppFn("fromUInt64NoTruncate", .{ globalObject, i });
+    }
+    pub fn toUInt64NoTruncate(this: JSValue) u64 {
+        return cppFn("toUInt64NoTruncate", .{
+            this,
+        });
+    }
+
     pub inline fn getZigString(this: JSValue, global: *JSGlobalObject) ZigString {
         var str = ZigString.init("");
         this.toZigString(&str, global);
@@ -2828,7 +2840,7 @@ pub const JSValue = enum(u64) {
         return @intToPtr(*anyopaque, @enumToInt(this));
     }
 
-    pub const Extern = [_][]const u8{ "asPromise", "toInt64", "_then", "put", "makeWithNameAndPrototype", "parseJSON", "symbolKeyFor", "symbolFor", "getSymbolDescription", "createInternalPromise", "asInternalPromise", "asArrayBuffer_", "getReadableStreamState", "getWritableStreamState", "fromEntries", "createTypeError", "createRangeError", "createObject2", "getIfPropertyExistsImpl", "jsType", "jsonStringify", "kind_", "isTerminationException", "isSameValue", "getLengthOfArray", "toZigString", "createStringArray", "createEmptyObject", "putRecord", "asPromise", "isClass", "getNameProperty", "getClassName", "getErrorsProperty", "toInt32", "toBoolean", "isInt32", "isIterable", "forEach", "isAggregateError", "toZigException", "isException", "toWTFString", "hasProperty", "getPropertyNames", "getDirect", "putDirect", "getIfExists", "asString", "asObject", "asNumber", "isError", "jsNull", "jsUndefined", "jsTDZValue", "jsBoolean", "jsDoubleNumber", "jsNumberFromDouble", "jsNumberFromChar", "jsNumberFromU16", "jsNumberFromInt32", "jsNumberFromInt64", "jsNumberFromUint64", "isBoolean", "isAnyInt", "isUInt32AsAnyInt", "isInt32AsAnyInt", "isNumber", "isString", "isBigInt", "isHeapBigInt", "isBigInt32", "isSymbol", "isPrimitive", "isGetterSetter", "isCustomGetterSetter", "isObject", "isCell", "asCell", "toString", "toStringOrNull", "toPropertyKey", "toPropertyKeyValue", "toObject", "toString", "getPrototype", "getPropertyByPropertyName", "eqlValue", "eqlCell", "isCallable" };
+    pub const Extern = [_][]const u8{ "fromInt64NoTruncate", "fromUInt64NoTruncate", "toUInt64NoTruncate", "asPromise", "toInt64", "_then", "put", "makeWithNameAndPrototype", "parseJSON", "symbolKeyFor", "symbolFor", "getSymbolDescription", "createInternalPromise", "asInternalPromise", "asArrayBuffer_", "getReadableStreamState", "getWritableStreamState", "fromEntries", "createTypeError", "createRangeError", "createObject2", "getIfPropertyExistsImpl", "jsType", "jsonStringify", "kind_", "isTerminationException", "isSameValue", "getLengthOfArray", "toZigString", "createStringArray", "createEmptyObject", "putRecord", "asPromise", "isClass", "getNameProperty", "getClassName", "getErrorsProperty", "toInt32", "toBoolean", "isInt32", "isIterable", "forEach", "isAggregateError", "toZigException", "isException", "toWTFString", "hasProperty", "getPropertyNames", "getDirect", "putDirect", "getIfExists", "asString", "asObject", "asNumber", "isError", "jsNull", "jsUndefined", "jsTDZValue", "jsBoolean", "jsDoubleNumber", "jsNumberFromDouble", "jsNumberFromChar", "jsNumberFromU16", "jsNumberFromInt32", "jsNumberFromInt64", "jsNumberFromUint64", "isBoolean", "isAnyInt", "isUInt32AsAnyInt", "isInt32AsAnyInt", "isNumber", "isString", "isBigInt", "isHeapBigInt", "isBigInt32", "isSymbol", "isPrimitive", "isGetterSetter", "isCustomGetterSetter", "isObject", "isCell", "asCell", "toString", "toStringOrNull", "toPropertyKey", "toPropertyKeyValue", "toObject", "toString", "getPrototype", "getPropertyByPropertyName", "eqlValue", "eqlCell", "isCallable" };
 };
 
 extern "c" fn Microtask__run(*Microtask, *JSGlobalObject) void;
diff --git a/src/javascript/jsc/bindings/headers-cpp.h b/src/javascript/jsc/bindings/headers-cpp.h
index fdac529b7..e33e5893c 100644
--- a/src/javascript/jsc/bindings/headers-cpp.h
+++ b/src/javascript/jsc/bindings/headers-cpp.h
@@ -1,4 +1,4 @@
-//-- AUTOGENERATED FILE -- 1651480881
+//-- AUTOGENERATED FILE -- 1651495723
 // clang-format off
 #pragma once
 
@@ -218,7 +218,7 @@ extern "C" const size_t WTF__StringView_object_align_ = alignof(WTF::StringView)
 
 #ifndef INCLUDED__ZigGlobalObject_h_
 #define INCLUDED__ZigGlobalObject_h_
-#include "ZigGlobalObject.h"
+#include ""ZigGlobalObject.h""
 #endif
 
 extern "C" const size_t Zig__GlobalObject_object_size_ = sizeof(Zig::GlobalObject);
@@ -242,9 +242,7 @@ extern "C" const size_t Bun__Writable_object_align_ = alignof(Bun__Writable);
 
 #ifndef INCLUDED_Path_h
 #define INCLUDED_Path_h
-// #include "Path.h"
-#define Bun__Path void*
-#define Bun__Timer void*
+#include "Path.h"
 #endif
 
 extern "C" const size_t Bun__Path_object_size_ = sizeof(Bun__Path);
@@ -252,7 +250,7 @@ extern "C" const size_t Bun__Path_object_align_ = alignof(Bun__Path);
 
 #ifndef INCLUDED__ZigConsoleClient_h_
 #define INCLUDED__ZigConsoleClient_h_
-#include "ZigConsoleClient.h"
+#include ""ZigConsoleClient.h""
 #endif
 
 extern "C" const size_t Zig__ConsoleClient_object_size_ = sizeof(Zig::ConsoleClient);
@@ -260,7 +258,7 @@ extern "C" const size_t Zig__ConsoleClient_object_align_ = alignof(Zig::ConsoleC
 
 #ifndef INCLUDED_
 #define INCLUDED_
-// #include ""
+#include ""
 #endif
 
 extern "C" const size_t Bun__Timer_object_size_ = sizeof(Bun__Timer);
diff --git a/src/javascript/jsc/bindings/headers.h b/src/javascript/jsc/bindings/headers.h
index 057e38eb8..5e58781e2 100644
--- a/src/javascript/jsc/bindings/headers.h
+++ b/src/javascript/jsc/bindings/headers.h
@@ -1,5 +1,5 @@
 // clang-format: off
-//-- AUTOGENERATED FILE -- 1651480881
+//-- AUTOGENERATED FILE -- 1651495723
 #pragma once
 
 #include <stddef.h>
@@ -55,7 +55,7 @@ typedef struct bJSC__PropertyName {
 } bJSC__PropertyName;
 typedef char* bJSC__PropertyName_buf;
 typedef struct bJSC__JSGlobalObject {
-    unsigned char bytes[2400];
+    unsigned char bytes[2312];
 } bJSC__JSGlobalObject;
 typedef char* bJSC__JSGlobalObject_buf;
 typedef struct bJSC__JSCell {
@@ -87,7 +87,7 @@ typedef struct bJSC__Exception {
 } bJSC__Exception;
 typedef char* bJSC__Exception_buf;
 typedef struct bJSC__VM {
-    unsigned char bytes[48824];
+    unsigned char bytes[52168];
 } bJSC__VM;
 typedef char* bJSC__VM_buf;
 typedef struct bJSC__JSString {
@@ -99,7 +99,7 @@ typedef struct bJSC__SourceOrigin {
 } bJSC__SourceOrigin;
 typedef char* bJSC__SourceOrigin_buf;
 typedef struct bWTF__ExternalStringImpl {
-    unsigned char bytes[32];
+    unsigned char bytes[40];
 } bWTF__ExternalStringImpl;
 typedef char* bWTF__ExternalStringImpl_buf;
 typedef struct bJSC__JSInternalPromise {
@@ -528,6 +528,8 @@ CPP_DECL bool JSC__JSValue__eqlCell(JSC__JSValue JSValue0, JSC__JSCell* arg1);
 CPP_DECL bool JSC__JSValue__eqlValue(JSC__JSValue JSValue0, JSC__JSValue JSValue1);
 CPP_DECL void JSC__JSValue__forEach(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1, void* arg2, void (*ArgFn3)(JSC__VM* arg0, JSC__JSGlobalObject* arg1, void* arg2, JSC__JSValue JSValue3));
 CPP_DECL JSC__JSValue JSC__JSValue__fromEntries(JSC__JSGlobalObject* arg0, ZigString* arg1, ZigString* arg2, size_t arg3, bool arg4);
+CPP_DECL JSC__JSValue JSC__JSValue__fromInt64NoTruncate(JSC__JSGlobalObject* arg0, int64_t arg1);
+CPP_DECL JSC__JSValue JSC__JSValue__fromUInt64NoTruncate(JSC__JSGlobalObject* arg0, uint64_t arg1);
 CPP_DECL void JSC__JSValue__getClassName(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1, ZigString* arg2);
 CPP_DECL JSC__JSValue JSC__JSValue__getErrorsProperty(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1);
 CPP_DECL JSC__JSValue JSC__JSValue__getIfPropertyExistsImpl(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1, const unsigned char* arg2, uint32_t arg3);
@@ -589,6 +591,7 @@ CPP_DECL JSC__JSValue JSC__JSValue__toPropertyKeyValue(JSC__JSValue JSValue0, JS
 CPP_DECL JSC__JSString* JSC__JSValue__toString(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1);
 CPP_DECL JSC__JSString* JSC__JSValue__toString(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1);
 CPP_DECL JSC__JSString* JSC__JSValue__toStringOrNull(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1);
+CPP_DECL uint64_t JSC__JSValue__toUInt64NoTruncate(JSC__JSValue JSValue0);
 CPP_DECL bWTF__String JSC__JSValue__toWTFString(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1);
 CPP_DECL void JSC__JSValue__toZigException(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1, ZigException* arg2);
 CPP_DECL void JSC__JSValue__toZigString(JSC__JSValue JSValue0, ZigString* arg1, JSC__JSGlobalObject* arg2);
diff --git a/src/javascript/jsc/bindings/headers.zig b/src/javascript/jsc/bindings/headers.zig
index 6fd6b644b..3b74bd4cd 100644
--- a/src/javascript/jsc/bindings/headers.zig
+++ b/src/javascript/jsc/bindings/headers.zig
@@ -324,6 +324,8 @@ pub extern fn JSC__JSValue__eqlCell(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSCel
 pub extern fn JSC__JSValue__eqlValue(JSValue0: JSC__JSValue, JSValue1: JSC__JSValue) bool;
 pub extern fn JSC__JSValue__forEach(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject, arg2: ?*anyopaque, ArgFn3: ?fn ([*c]JSC__VM, [*c]JSC__JSGlobalObject, ?*anyopaque, JSC__JSValue) callconv(.C) void) void;
 pub extern fn JSC__JSValue__fromEntries(arg0: [*c]JSC__JSGlobalObject, arg1: [*c]ZigString, arg2: [*c]ZigString, arg3: usize, arg4: bool) JSC__JSValue;
+pub extern fn JSC__JSValue__fromInt64NoTruncate(arg0: [*c]JSC__JSGlobalObject, arg1: i64) JSC__JSValue;
+pub extern fn JSC__JSValue__fromUInt64NoTruncate(arg0: [*c]JSC__JSGlobalObject, arg1: u64) JSC__JSValue;
 pub extern fn JSC__JSValue__getClassName(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject, arg2: [*c]ZigString) void;
 pub extern fn JSC__JSValue__getErrorsProperty(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject) JSC__JSValue;
 pub extern fn JSC__JSValue__getIfPropertyExistsImpl(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject, arg2: [*c]const u8, arg3: u32) JSC__JSValue;
@@ -384,6 +386,7 @@ pub extern fn JSC__JSValue__toPropertyKey(JSValue0: JSC__JSValue, arg1: [*c]JSC_
 pub extern fn JSC__JSValue__toPropertyKeyValue(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject) JSC__JSValue;
 pub extern fn JSC__JSValue__toString(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject) [*c]JSC__JSString;
 pub extern fn JSC__JSValue__toStringOrNull(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject) [*c]JSC__JSString;
+pub extern fn JSC__JSValue__toUInt64NoTruncate(JSValue0: JSC__JSValue) u64;
 pub extern fn JSC__JSValue__toWTFString(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject) bWTF__String;
 pub extern fn JSC__JSValue__toZigException(JSValue0: JSC__JSValue, arg1: [*c]JSC__JSGlobalObject, arg2: [*c]ZigException) void;
 pub extern fn JSC__JSValue__toZigString(JSValue0: JSC__JSValue, arg1: [*c]ZigString, arg2: [*c]JSC__JSGlobalObject) void;
diff --git a/src/javascript/jsc/ffi.exports.js b/src/javascript/jsc/ffi.exports.js
index 2f23f8104..8f6c47e41 100644
--- a/src/javascript/jsc/ffi.exports.js
+++ b/src/javascript/jsc/ffi.exports.js
@@ -84,6 +84,20 @@ ffiWrappers[FFIType.int64_t] = function int64(val) {
   return val;
 };
 
+ffiWrappers[FFIType.uint64_t] = function int64(val) {
+  if (typeof val === "bigint") {
+    if (val < Number.MAX_VALUE && val > 0) {
+      return Number(val).valueOf();
+    }
+  }
+
+  if (!val) {
+    return 0;
+  }
+
+  return val;
+};
+
 ffiWrappers[FFIType.uint16_t] = function uint64(val) {
   if (typeof val === "bigint") {
     if (val < Number.MAX_VALUE) {