xref: /third_party/node/deps/v8/include/v8-value.h (revision 1cb0ef41) 
1// Copyright 2021 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef INCLUDE_V8_VALUE_H_
6#define INCLUDE_V8_VALUE_H_
7
8#include "v8-data.h"          // NOLINT(build/include_directory)
9#include "v8-internal.h"      // NOLINT(build/include_directory)
10#include "v8-local-handle.h"  // NOLINT(build/include_directory)
11#include "v8-maybe.h"         // NOLINT(build/include_directory)
12#include "v8config.h"         // NOLINT(build/include_directory)
13
14/**
15 * The v8 JavaScript engine.
16 */
17namespace v8 {
18
19class BigInt;
20class Int32;
21class Integer;
22class Number;
23class Object;
24class String;
25class Uint32;
26
27/**
28 * The superclass of all JavaScript values and objects.
29 */
30class V8_EXPORT Value : public Data {
31 public:
32  /**
33   * Returns true if this value is the undefined value.  See ECMA-262
34   * 4.3.10.
35   *
36   * This is equivalent to `value === undefined` in JS.
37   */
38  V8_INLINE bool IsUndefined() const;
39
40  /**
41   * Returns true if this value is the null value.  See ECMA-262
42   * 4.3.11.
43   *
44   * This is equivalent to `value === null` in JS.
45   */
46  V8_INLINE bool IsNull() const;
47
48  /**
49   * Returns true if this value is either the null or the undefined value.
50   * See ECMA-262
51   * 4.3.11. and 4.3.12
52   *
53   * This is equivalent to `value == null` in JS.
54   */
55  V8_INLINE bool IsNullOrUndefined() const;
56
57  /**
58   * Returns true if this value is true.
59   *
60   * This is not the same as `BooleanValue()`. The latter performs a
61   * conversion to boolean, i.e. the result of `Boolean(value)` in JS, whereas
62   * this checks `value === true`.
63   */
64  bool IsTrue() const;
65
66  /**
67   * Returns true if this value is false.
68   *
69   * This is not the same as `!BooleanValue()`. The latter performs a
70   * conversion to boolean, i.e. the result of `!Boolean(value)` in JS, whereas
71   * this checks `value === false`.
72   */
73  bool IsFalse() const;
74
75  /**
76   * Returns true if this value is a symbol or a string.
77   *
78   * This is equivalent to
79   * `typeof value === 'string' || typeof value === 'symbol'` in JS.
80   */
81  bool IsName() const;
82
83  /**
84   * Returns true if this value is an instance of the String type.
85   * See ECMA-262 8.4.
86   *
87   * This is equivalent to `typeof value === 'string'` in JS.
88   */
89  V8_INLINE bool IsString() const;
90
91  /**
92   * Returns true if this value is a symbol.
93   *
94   * This is equivalent to `typeof value === 'symbol'` in JS.
95   */
96  bool IsSymbol() const;
97
98  /**
99   * Returns true if this value is a function.
100   *
101   * This is equivalent to `typeof value === 'function'` in JS.
102   */
103  bool IsFunction() const;
104
105  /**
106   * Returns true if this value is an array. Note that it will return false for
107   * an Proxy for an array.
108   */
109  bool IsArray() const;
110
111  /**
112   * Returns true if this value is an object.
113   */
114  bool IsObject() const;
115
116  /**
117   * Returns true if this value is a bigint.
118   *
119   * This is equivalent to `typeof value === 'bigint'` in JS.
120   */
121  bool IsBigInt() const;
122
123  /**
124   * Returns true if this value is boolean.
125   *
126   * This is equivalent to `typeof value === 'boolean'` in JS.
127   */
128  bool IsBoolean() const;
129
130  /**
131   * Returns true if this value is a number.
132   *
133   * This is equivalent to `typeof value === 'number'` in JS.
134   */
135  bool IsNumber() const;
136
137  /**
138   * Returns true if this value is an `External` object.
139   */
140  bool IsExternal() const;
141
142  /**
143   * Returns true if this value is a 32-bit signed integer.
144   */
145  bool IsInt32() const;
146
147  /**
148   * Returns true if this value is a 32-bit unsigned integer.
149   */
150  bool IsUint32() const;
151
152  /**
153   * Returns true if this value is a Date.
154   */
155  bool IsDate() const;
156
157  /**
158   * Returns true if this value is an Arguments object.
159   */
160  bool IsArgumentsObject() const;
161
162  /**
163   * Returns true if this value is a BigInt object.
164   */
165  bool IsBigIntObject() const;
166
167  /**
168   * Returns true if this value is a Boolean object.
169   */
170  bool IsBooleanObject() const;
171
172  /**
173   * Returns true if this value is a Number object.
174   */
175  bool IsNumberObject() const;
176
177  /**
178   * Returns true if this value is a String object.
179   */
180  bool IsStringObject() const;
181
182  /**
183   * Returns true if this value is a Symbol object.
184   */
185  bool IsSymbolObject() const;
186
187  /**
188   * Returns true if this value is a NativeError.
189   */
190  bool IsNativeError() const;
191
192  /**
193   * Returns true if this value is a RegExp.
194   */
195  bool IsRegExp() const;
196
197  /**
198   * Returns true if this value is an async function.
199   */
200  bool IsAsyncFunction() const;
201
202  /**
203   * Returns true if this value is a Generator function.
204   */
205  bool IsGeneratorFunction() const;
206
207  /**
208   * Returns true if this value is a Generator object (iterator).
209   */
210  bool IsGeneratorObject() const;
211
212  /**
213   * Returns true if this value is a Promise.
214   */
215  bool IsPromise() const;
216
217  /**
218   * Returns true if this value is a Map.
219   */
220  bool IsMap() const;
221
222  /**
223   * Returns true if this value is a Set.
224   */
225  bool IsSet() const;
226
227  /**
228   * Returns true if this value is a Map Iterator.
229   */
230  bool IsMapIterator() const;
231
232  /**
233   * Returns true if this value is a Set Iterator.
234   */
235  bool IsSetIterator() const;
236
237  /**
238   * Returns true if this value is a WeakMap.
239   */
240  bool IsWeakMap() const;
241
242  /**
243   * Returns true if this value is a WeakSet.
244   */
245  bool IsWeakSet() const;
246
247  /**
248   * Returns true if this value is an ArrayBuffer.
249   */
250  bool IsArrayBuffer() const;
251
252  /**
253   * Returns true if this value is an ArrayBufferView.
254   */
255  bool IsArrayBufferView() const;
256
257  /**
258   * Returns true if this value is one of TypedArrays.
259   */
260  bool IsTypedArray() const;
261
262  /**
263   * Returns true if this value is an Uint8Array.
264   */
265  bool IsUint8Array() const;
266
267  /**
268   * Returns true if this value is an Uint8ClampedArray.
269   */
270  bool IsUint8ClampedArray() const;
271
272  /**
273   * Returns true if this value is an Int8Array.
274   */
275  bool IsInt8Array() const;
276
277  /**
278   * Returns true if this value is an Uint16Array.
279   */
280  bool IsUint16Array() const;
281
282  /**
283   * Returns true if this value is an Int16Array.
284   */
285  bool IsInt16Array() const;
286
287  /**
288   * Returns true if this value is an Uint32Array.
289   */
290  bool IsUint32Array() const;
291
292  /**
293   * Returns true if this value is an Int32Array.
294   */
295  bool IsInt32Array() const;
296
297  /**
298   * Returns true if this value is a Float32Array.
299   */
300  bool IsFloat32Array() const;
301
302  /**
303   * Returns true if this value is a Float64Array.
304   */
305  bool IsFloat64Array() const;
306
307  /**
308   * Returns true if this value is a BigInt64Array.
309   */
310  bool IsBigInt64Array() const;
311
312  /**
313   * Returns true if this value is a BigUint64Array.
314   */
315  bool IsBigUint64Array() const;
316
317  /**
318   * Returns true if this value is a DataView.
319   */
320  bool IsDataView() const;
321
322  /**
323   * Returns true if this value is a SharedArrayBuffer.
324   */
325  bool IsSharedArrayBuffer() const;
326
327  /**
328   * Returns true if this value is a JavaScript Proxy.
329   */
330  bool IsProxy() const;
331
332  /**
333   * Returns true if this value is a WasmMemoryObject.
334   */
335  bool IsWasmMemoryObject() const;
336
337  /**
338   * Returns true if this value is a WasmModuleObject.
339   */
340  bool IsWasmModuleObject() const;
341
342  /**
343   * Returns true if the value is a Module Namespace Object.
344   */
345  bool IsModuleNamespaceObject() const;
346
347  /**
348   * Perform the equivalent of `BigInt(value)` in JS.
349   */
350  V8_WARN_UNUSED_RESULT MaybeLocal<BigInt> ToBigInt(
351      Local<Context> context) const;
352  /**
353   * Perform the equivalent of `Number(value)` in JS.
354   */
355  V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
356      Local<Context> context) const;
357  /**
358   * Perform the equivalent of `String(value)` in JS.
359   */
360  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
361      Local<Context> context) const;
362  /**
363   * Provide a string representation of this value usable for debugging.
364   * This operation has no observable side effects and will succeed
365   * unless e.g. execution is being terminated.
366   */
367  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
368      Local<Context> context) const;
369  /**
370   * Perform the equivalent of `Object(value)` in JS.
371   */
372  V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
373      Local<Context> context) const;
374  /**
375   * Perform the equivalent of `Number(value)` in JS and convert the result
376   * to an integer. Negative values are rounded up, positive values are rounded
377   * down. NaN is converted to 0. Infinite values yield undefined results.
378   */
379  V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
380      Local<Context> context) const;
381  /**
382   * Perform the equivalent of `Number(value)` in JS and convert the result
383   * to an unsigned 32-bit integer by performing the steps in
384   * https://tc39.es/ecma262/#sec-touint32.
385   */
386  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
387      Local<Context> context) const;
388  /**
389   * Perform the equivalent of `Number(value)` in JS and convert the result
390   * to a signed 32-bit integer by performing the steps in
391   * https://tc39.es/ecma262/#sec-toint32.
392   */
393  V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
394
395  /**
396   * Perform the equivalent of `Boolean(value)` in JS. This can never fail.
397   */
398  Local<Boolean> ToBoolean(Isolate* isolate) const;
399
400  /**
401   * Attempts to convert a string to an array index.
402   * Returns an empty handle if the conversion fails.
403   */
404  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
405      Local<Context> context) const;
406
407  /** Returns the equivalent of `ToBoolean()->Value()`. */
408  bool BooleanValue(Isolate* isolate) const;
409
410  /** Returns the equivalent of `ToNumber()->Value()`. */
411  V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
412  /** Returns the equivalent of `ToInteger()->Value()`. */
413  V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
414      Local<Context> context) const;
415  /** Returns the equivalent of `ToUint32()->Value()`. */
416  V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
417      Local<Context> context) const;
418  /** Returns the equivalent of `ToInt32()->Value()`. */
419  V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
420
421  /** JS == */
422  V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
423                                           Local<Value> that) const;
424  bool StrictEquals(Local<Value> that) const;
425  bool SameValue(Local<Value> that) const;
426
427  template <class T>
428  V8_INLINE static Value* Cast(T* value) {
429    return static_cast<Value*>(value);
430  }
431
432  Local<String> TypeOf(Isolate*);
433
434  Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
435
436 private:
437  V8_INLINE bool QuickIsUndefined() const;
438  V8_INLINE bool QuickIsNull() const;
439  V8_INLINE bool QuickIsNullOrUndefined() const;
440  V8_INLINE bool QuickIsString() const;
441  bool FullIsUndefined() const;
442  bool FullIsNull() const;
443  bool FullIsString() const;
444
445  static void CheckCast(Data* that);
446};
447
448template <>
449V8_INLINE Value* Value::Cast(Data* value) {
450#ifdef V8_ENABLE_CHECKS
451  CheckCast(value);
452#endif
453  return static_cast<Value*>(value);
454}
455
456bool Value::IsUndefined() const {
457#ifdef V8_ENABLE_CHECKS
458  return FullIsUndefined();
459#else
460  return QuickIsUndefined();
461#endif
462}
463
464bool Value::QuickIsUndefined() const {
465  using A = internal::Address;
466  using I = internal::Internals;
467  A obj = *reinterpret_cast<const A*>(this);
468  if (!I::HasHeapObjectTag(obj)) return false;
469  if (I::GetInstanceType(obj) != I::kOddballType) return false;
470  return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
471}
472
473bool Value::IsNull() const {
474#ifdef V8_ENABLE_CHECKS
475  return FullIsNull();
476#else
477  return QuickIsNull();
478#endif
479}
480
481bool Value::QuickIsNull() const {
482  using A = internal::Address;
483  using I = internal::Internals;
484  A obj = *reinterpret_cast<const A*>(this);
485  if (!I::HasHeapObjectTag(obj)) return false;
486  if (I::GetInstanceType(obj) != I::kOddballType) return false;
487  return (I::GetOddballKind(obj) == I::kNullOddballKind);
488}
489
490bool Value::IsNullOrUndefined() const {
491#ifdef V8_ENABLE_CHECKS
492  return FullIsNull() || FullIsUndefined();
493#else
494  return QuickIsNullOrUndefined();
495#endif
496}
497
498bool Value::QuickIsNullOrUndefined() const {
499  using A = internal::Address;
500  using I = internal::Internals;
501  A obj = *reinterpret_cast<const A*>(this);
502  if (!I::HasHeapObjectTag(obj)) return false;
503  if (I::GetInstanceType(obj) != I::kOddballType) return false;
504  int kind = I::GetOddballKind(obj);
505  return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
506}
507
508bool Value::IsString() const {
509#ifdef V8_ENABLE_CHECKS
510  return FullIsString();
511#else
512  return QuickIsString();
513#endif
514}
515
516bool Value::QuickIsString() const {
517  using A = internal::Address;
518  using I = internal::Internals;
519  A obj = *reinterpret_cast<const A*>(this);
520  if (!I::HasHeapObjectTag(obj)) return false;
521  return (I::GetInstanceType(obj) < I::kFirstNonstringType);
522}
523
524}  // namespace v8
525
526#endif  // INCLUDE_V8_VALUE_H_
527