napi: add bigint support

doc/api/n-api.md

@@ -113,10 +113,9 @@ typedef enum {
   napi_escape_called_twice,
   napi_handle_scope_mismatch,
   napi_callback_scope_mismatch,
-#ifdef NAPI_EXPERIMENTAL
   napi_queue_full,
   napi_closing,
-#endif  // NAPI_EXPERIMENTAL
+  napi_bigint_expected,
 } napi_status;
 ```
 If additional information is required upon an API returning a failed status,
@@ -1225,6 +1224,7 @@ typedef enum {
   napi_object,
   napi_function,
   napi_external,
+  napi_bigint,
 } napi_valuetype;
 ```
 
@@ -1250,6 +1250,8 @@ typedef enum {
   napi_uint32_array,
   napi_float32_array,
   napi_float64_array,
+  napi_bigint64_array,
+  napi_biguint64_array,
 } napi_typedarray_type;
 ```
 
@@ -1691,6 +1693,78 @@ This API is used to convert from the C `double` type to the JavaScript
 The JavaScript `Number` type is described in
 [Section 6.1.6][] of the ECMAScript Language Specification.
 
+#### napi_create_bigint_int64
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_create_bigint_int64(napi_env env,
+                                     int64_t value,
+                                     napi_value* result);
+```
+
+- `[in] env`: The environment that the API is invoked under.
+- `[in] value`: Integer value to be represented in JavaScript.
+- `[out] result`: A `napi_value` representing a JavaScript `BigInt`.
+
+Returns `napi_ok` if the API succeeded.
+
+This API converts the C `int64_t` type to the JavaScript `BigInt` type.
+
+#### napi_create_bigint_uint64
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_create_bigint_uint64(napi_env env,
+                                      uint64_t vaue,
+                                      napi_value* result);
+```
+
+- `[in] env`: The environment that the API is invoked under.
+- `[in] value`: Unsigned integer value to be represented in JavaScript.
+- `[out] result`: A `napi_value` representing a JavaScript `BigInt`.
+
+Returns `napi_ok` if the API succeeded.
+
+This API converts the C `uint64_t` type to the JavaScript `BigInt` type.
+
+#### napi_create_bigint_words
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_create_bigint_words(napi_env env,
+                                     int sign_bit,
+                                     size_t word_count,
+                                     const uint64_t* words,
+                                     napi_value* result);
+```
+
+- `[in] env`: The environment that the API is invoked under.
+- `[in] sign_bit`: Determines if the resulting `BigInt` will be positive or
+  negative.
+- `[in] word_count`: The length of the `words` array.
+- `[in] words`: An array of `uint64_t` little-endian 64-bit words.
+- `[out] result`: A `napi_value` representing a JavaScript `BigInt`.
+
+Returns `napi_ok` if the API succeeded.
+
+This API converts an array of unsigned 64-bit words into a single `BigInt`
+value.
+
+The resulting `BigInt` is calculated as: (–1)<sup>`sign_bit`</sup> (`words[0]`
+× (2<sup>64</sup>)<sup>0</sup> + `words[1]` × (2<sup>64</sup>)<sup>1</sup> + …)
+
 #### napi_create_string_latin1
 <!-- YAML
 added: v8.0.0
@@ -1975,6 +2049,92 @@ in it returns `napi_number_expected`.
 This API returns the C double primitive equivalent of the given JavaScript
 `Number`.
 
+#### napi_get_value_bigint_int64
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_get_value_bigint_int64(napi_env env,
+                                        napi_value value,
+                                        int64_t* result,
+                                        bool* lossless);
+```
+
+- `[in] env`: The environment that the API is invoked under
+- `[in] value`: `napi_value` representing JavaScript `BigInt`.
+- `[out] result`: C `int64_t` primitive equivalent of the given JavaScript
+  `BigInt`.
+- `[out] lossless`: Indicates whether the `BigInt` value was converted
+  losslessly.
+
+Returns `napi_ok` if the API succeeded. If a non-`BigInt` is passed in it
+returns `napi_bigint_expected`.
+
+This API returns the C `int64_t` primitive equivalent of the given JavaScript
+`BigInt`. If needed it will truncate the value, setting `lossless` to `false`.
+
+
+#### napi_get_value_bigint_uint64
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_get_value_bigint_uint64(napi_env env,
+                                        napi_value value,
+                                        uint64_t* result,
+                                        bool* lossless);
+```
+
+- `[in] env`: The environment that the API is invoked under.
+- `[in] value`: `napi_value` representing JavaScript `BigInt`.
+- `[out] result`: C `uint64_t` primitive equivalent of the given JavaScript
+  `BigInt`.
+- `[out] lossless`: Indicates whether the `BigInt` value was converted
+  losslessly.
+
+Returns `napi_ok` if the API succeeded. If a non-`BigInt` is passed in it
+returns `napi_bigint_expected`.
+
+This API returns the C `uint64_t` primitive equivalent of the given JavaScript
+`BigInt`. If needed it will truncate the value, setting `lossless` to `true`.
+
+
+#### napi_get_value_bigint_words
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+```C
+napi_status napi_get_value_bigint_words(napi_env env,
+                                        napi_value value,
+                                        size_t* word_count,
+                                        int* sign_bit,
+                                        uint64_t* words);
+```
+
+- `[in] env`: The environment that the API is invoked under.
+- `[in] value`: `napi_value` representing JavaScript `BigInt`.
+- `[out] sign_bit`: Integer representing if the JavaScript `BigInt` is positive
+   or negative.
+- `[in/out] word_count`: Must be initialized to the length of the `words`
+   array. Upon return, it will be set to the actual number of words that
+   would be needed to store this `BigInt`.
+- `[out] words`: Pointer to 64-bit word array.
+
+Returns `napi_ok` if the API succeeded.
+
+This API converts a single `BigInt` value into a sign bit, 64-bit little-endian
+array, and the number of elements in the array. `sign_bit` and `words` may be
+both set to `NULL`, in order to get only `word_count`.
+
 #### napi_get_value_external
 <!-- YAML
 added: v8.0.0

src/node_api.cc

@@ -926,7 +926,8 @@ const char* error_messages[] = {nullptr,
                                 "Invalid handle scope usage",
                                 "Invalid callback scope usage",
                                 "Thread-safe function queue is full",
-                                "Thread-safe function handle is closing"
+                                "Thread-safe function handle is closing",
+                                "A bigint was expected",
 };
 
 static inline napi_status napi_clear_last_error(napi_env env) {
@@ -958,7 +959,7 @@ napi_status napi_get_last_error_info(napi_env env,
   // We don't have a napi_status_last as this would result in an ABI
   // change each time a message was added.
   static_assert(
-      node::arraysize(error_messages) == napi_closing + 1,
+      node::arraysize(error_messages) == napi_bigint_expected + 1,
       "Count of error messages must match count of error values");
   CHECK_LE(env->last_error.error_code, napi_callback_scope_mismatch);
 
@@ -1713,6 +1714,58 @@ napi_status napi_create_int64(napi_env env,
   return napi_clear_last_error(env);
 }
 
+napi_status napi_create_bigint_int64(napi_env env,
+                                     int64_t value,
+                                     napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::BigInt::New(env->isolate, value));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_bigint_uint64(napi_env env,
+                                      uint64_t value,
+                                      napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::BigInt::NewFromUnsigned(env->isolate, value));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_bigint_words(napi_env env,
+                                     int sign_bit,
+                                     size_t word_count,
+                                     const uint64_t* words,
+                                     napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, words);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Context> context = env->isolate->GetCurrentContext();
+
+  if (word_count > INT_MAX) {
+    napi_throw_range_error(env, nullptr, "Maximum BigInt size exceeded");
+    return napi_set_last_error(env, napi_pending_exception);
+  }
+
+  v8::MaybeLocal<v8::BigInt> b = v8::BigInt::NewFromWords(
+      context, sign_bit, word_count, words);
+
+  if (try_catch.HasCaught()) {
+    return napi_set_last_error(env, napi_pending_exception);
+  } else {
+    CHECK_MAYBE_EMPTY(env, b, napi_generic_failure);
+    *result = v8impl::JsValueFromV8LocalValue(b.ToLocalChecked());
+    return napi_clear_last_error(env);
+  }
+}
+
 napi_status napi_get_boolean(napi_env env, bool value, napi_value* result) {
   CHECK_ENV(env);
   CHECK_ARG(env, result);
@@ -1878,6 +1931,8 @@ napi_status napi_typeof(napi_env env,
 
   if (v->IsNumber()) {
     *result = napi_number;
+  } else if (v->IsBigInt()) {
+    *result = napi_bigint;
   } else if (v->IsString()) {
     *result = napi_string;
   } else if (v->IsFunction()) {
@@ -2201,6 +2256,72 @@ napi_status napi_get_value_int64(napi_env env,
   return napi_clear_last_error(env);
 }
 
+napi_status napi_get_value_bigint_int64(napi_env env,
+                                        napi_value value,
+                                        int64_t* result,
+                                        bool* lossless) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+  CHECK_ARG(env, lossless);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  RETURN_STATUS_IF_FALSE(env, val->IsBigInt(), napi_bigint_expected);
+
+  *result = val.As<v8::BigInt>()->Int64Value(lossless);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_bigint_uint64(napi_env env,
+                                         napi_value value,
+                                         uint64_t* result,
+                                         bool* lossless) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+  CHECK_ARG(env, lossless);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  RETURN_STATUS_IF_FALSE(env, val->IsBigInt(), napi_bigint_expected);
+
+  *result = val.As<v8::BigInt>()->Uint64Value(lossless);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_bigint_words(napi_env env,
+                                        napi_value value,
+                                        int* sign_bit,
+                                        size_t* word_count,
+                                        uint64_t* words) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, word_count);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  RETURN_STATUS_IF_FALSE(env, val->IsBigInt(), napi_bigint_expected);
+
+  v8::Local<v8::BigInt> big = val.As<v8::BigInt>();
+
+  int word_count_int = *word_count;
+
+  if (sign_bit == nullptr && words == nullptr) {
+    word_count_int = big->WordCount();
+  } else {
+    CHECK_ARG(env, sign_bit);
+    CHECK_ARG(env, words);
+    big->ToWordsArray(sign_bit, &word_count_int, words);
+  }
+
+  *word_count = word_count_int;
+
+  return napi_clear_last_error(env);
+}
+
 napi_status napi_get_value_bool(napi_env env, napi_value value, bool* result) {
   // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
   // JS exceptions.
@@ -3139,6 +3260,14 @@ napi_status napi_create_typedarray(napi_env env,
       CREATE_TYPED_ARRAY(
           env, Float64Array, 8, buffer, byte_offset, length, typedArray);
       break;
+    case napi_bigint64_array:
+      CREATE_TYPED_ARRAY(
+          env, BigInt64Array, 8, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_biguint64_array:
+      CREATE_TYPED_ARRAY(
+          env, BigUint64Array, 8, buffer, byte_offset, length, typedArray);
+      break;
     default:
       return napi_set_last_error(env, napi_invalid_arg);
   }
@@ -3181,6 +3310,10 @@ napi_status napi_get_typedarray_info(napi_env env,
       *type = napi_float32_array;
     } else if (value->IsFloat64Array()) {
       *type = napi_float64_array;
+    } else if (value->IsBigInt64Array()) {
+      *type = napi_bigint64_array;
+    } else if (value->IsBigUint64Array()) {
+      *type = napi_biguint64_array;
     }
   }