represent napi_callback_info with non-zero number (#78)

* add cbinfo test

* implement real napi_callback_info pointer

packages/emnapi/src/function.ts

@@ -20,11 +20,11 @@ function napi_create_function (env: napi_env, utf8name: Pointer<const_char>, len
   })
 }
 
-function napi_get_cb_info (env: napi_env, _cbinfo: napi_callback_info, argc: Pointer<size_t>, argv: Pointer<napi_value>, this_arg: Pointer<napi_value>, data: void_pp): napi_status {
+function napi_get_cb_info (env: napi_env, cbinfo: napi_callback_info, argc: Pointer<size_t>, argv: Pointer<napi_value>, this_arg: Pointer<napi_value>, data: void_pp): napi_status {
   $CHECK_ENV!(env)
   const envObject = emnapiCtx.envStore.get(env)!
 
-  const cbinfoValue = emnapiCtx.cbinfoStack.current!
+  const cbinfoValue = emnapiCtx.cbinfoStack.get(cbinfo)!
 
   $from64('argc')
   $from64('argv')
@@ -160,7 +160,7 @@ function napi_new_instance (
 
 function napi_get_new_target (
   env: napi_env,
-  _cbinfo: napi_callback_info,
+  cbinfo: napi_callback_info,
   result: Pointer<napi_value>
 ): napi_status {
   $CHECK_ENV!(env)
@@ -170,7 +170,7 @@ function napi_get_new_target (
 
   $from64('result')
 
-  const cbinfoValue = emnapiCtx.cbinfoStack.current!
+  const cbinfoValue = emnapiCtx.cbinfoStack.get(cbinfo)!
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const value = cbinfoValue.getNewTarget(envObject)
   $makeSetValue('result', 0, 'value', '*')

packages/emnapi/src/internal.ts

@@ -11,11 +11,11 @@ function emnapiCreateFunction<F extends (...args: any[]) => any> (envObject: Env
 
   const makeFunction = () => function (this: any): any {
     'use strict'
-    emnapiCtx.cbinfoStack.push(this, data, arguments, f)
+    const cbinfo = emnapiCtx.cbinfoStack.push(this, data, arguments, f)
     const scope = emnapiCtx.openScope(envObject)
     try {
       return envObject.callIntoModule((envObject) => {
-        const napiValue = $makeDynCall('ppp', 'cb')(envObject.id, 0)
+        const napiValue = $makeDynCall('ppp', 'cb')(envObject.id, cbinfo)
         return (!napiValue) ? undefined : emnapiCtx.handleStore.get(napiValue)!.value
       })
     } finally {

packages/runtime/src/CallbackInfo.ts

@@ -1,8 +1,12 @@
 import type { Env } from './env'
 
+const EMPTY_ARGS = [] as const
+
 export class CallbackInfo {
   public constructor (
-    public parent: CallbackInfo | null,
+    public id: number,
+    public parent: CallbackInfo,
+    public child: CallbackInfo | null,
     public thiz: any,
     public data: void_p,
     public args: ArrayLike<any>,
@@ -14,29 +18,58 @@ export class CallbackInfo {
     if (thiz == null || thiz.constructor == null) return 0
     return thiz instanceof this.fn ? envObject.ensureHandleId(thiz.constructor) : 0
   }
+
+  public dispose (): void {
+    if (this.thiz !== undefined) this.thiz = undefined
+    this.args = EMPTY_ARGS
+    this.fn = null!
+  }
 }
 
+const ROOT_CBINFO = new CallbackInfo(0, null!, null, null, 0, null!, null!)
+
 export class CallbackInfoStack {
-  public current: CallbackInfo | null = null
+  public current: CallbackInfo = ROOT_CBINFO
+
+  public get (id: number): CallbackInfo | null {
+    if (id === 1) return ROOT_CBINFO.child!
+
+    let info = ROOT_CBINFO
+    for (let i = 0; i < id; ++i) {
+      info = info.child!
+      if (info === null) return null
+    }
+    return info === ROOT_CBINFO ? null : info
+  }
 
   public pop (): void {
     const current = this.current
-    if (current === null) return
+    if (current === ROOT_CBINFO) return
     this.current = current.parent
+    current.dispose()
   }
 
   public push (
     thiz: any,
     data: void_p,
     args: ArrayLike<any>,
     fn: Function
-  ): CallbackInfo {
-    const info = new CallbackInfo(this.current, thiz, data, args, fn)
+  ): number {
+    let info = this.current.child
+    if (info) {
+      info.thiz = thiz
+      info.data = data
+      info.args = args
+      info.fn = fn
+    } else {
+      info = new CallbackInfo(this.current.id + 1, this.current, null, thiz, data, args, fn)
+      this.current.child = info
+    }
     this.current = info
-    return info
+    return info.id
   }
 
   public dispose (): void {
-    this.current = null
+    this.current = null!
   }
 }

packages/test/CMakeLists.txt

@@ -264,6 +264,7 @@ if((NOT IS_WASM) OR IS_EMSCRIPTEN OR IS_WASI_THREADS)
 endif()
 
 add_test("arg" "./arg/binding.c" ON OFF "")
+add_test("cbinfo" "./cbinfo/binding.c" ON OFF "")
 add_test("callback" "./callback/binding.c" ON OFF "")
 add_test("objfac" "./objfac/binding.c" ON OFF "")
 add_test("fnfac" "./fnfac/binding.c" ON OFF "")

packages/test/cbinfo/binding.c

@@ -0,0 +1,69 @@
+#include <js_native_api.h>
+#include "../common.h"
+
+static napi_value Test1(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  NAPI_ASSERT(env, argc == 1,
+      "Test1: Wrong number of arguments. Expects a single argument.");
+
+  napi_valuetype valuetype0;
+  NAPI_CALL(env, napi_typeof(env, args[0], &valuetype0));
+  NAPI_ASSERT(env, valuetype0 == napi_function,
+      "Test1: Wrong type of arguments. Expects a function as first argument.");
+
+  napi_value argv[1];
+  NAPI_CALL(env, napi_create_bigint_int64(env, (int64_t) info, argv));
+
+  napi_value global;
+  NAPI_CALL(env, napi_get_global(env, &global));
+
+  napi_value cb = args[0];
+  NAPI_CALL(env, napi_call_function(env, global, cb, 1, argv, NULL));
+
+  return NULL;
+}
+
+static napi_value Test2(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  NAPI_ASSERT(env, argc == 1,
+      "Test2: Wrong number of arguments. Expects a single argument.");
+
+  napi_valuetype valuetype0;
+  NAPI_CALL(env, napi_typeof(env, args[0], &valuetype0));
+  NAPI_ASSERT(env, valuetype0 == napi_bigint,
+      "Test2: Wrong type of arguments. Expects a bigint as first argument.");
+
+  int64_t prev_info;
+  bool lossless;
+  NAPI_CALL(env, napi_get_value_bigint_int64(env, args[0], &prev_info, &lossless));
+
+  size_t prev_argc = 1;
+  napi_value prev_args[1];
+  NAPI_CALL(env, napi_get_cb_info(env, (napi_callback_info) prev_info, &prev_argc, prev_args, NULL, NULL));
+
+  NAPI_ASSERT(env, prev_argc == 1,
+      "Test2: Wrong number of arguments. Expects a single argument.");
+
+  napi_valuetype t;
+  NAPI_CALL(env, napi_typeof(env, prev_args[0], &t));
+  NAPI_ASSERT(env, t == napi_function,
+      "Test2: Wrong type of arguments. Expects a function as first argument.");
+  return NULL;
+}
+
+EXTERN_C_START
+napi_value Init(napi_env env, napi_value exports) {
+  napi_property_descriptor desc[2] = {
+    DECLARE_NAPI_PROPERTY("test1", Test1),
+    DECLARE_NAPI_PROPERTY("test2", Test2),
+  };
+  NAPI_CALL(env, napi_define_properties(env, exports, 2, desc));
+  return exports;
+}
+EXTERN_C_END

packages/test/cbinfo/cbinfo.test.js

@@ -0,0 +1,6 @@
+'use strict'
+const { load } = require('../util')
+
+module.exports = load('cbinfo').then(addon => {
+  addon.test1(addon.test2)
+})