V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
builtins-utils.h
1 // Copyright 2016 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 V8_BUILTINS_BUILTINS_UTILS_H_
6 #define V8_BUILTINS_BUILTINS_UTILS_H_
7 
8 #include "src/arguments.h"
9 #include "src/base/logging.h"
10 #include "src/builtins/builtins.h"
11 #include "src/heap/factory.h"
12 #include "src/isolate.h"
13 
14 namespace v8 {
15 namespace internal {
16 
17 // Arguments object passed to C++ builtins.
18 class BuiltinArguments : public Arguments {
19  public:
20  BuiltinArguments(int length, Address* arguments)
21  : Arguments(length, arguments) {
22  // Check we have at least the receiver.
23  DCHECK_LE(1, this->length());
24  }
25 
26  ObjectPtr operator[](int index) {
27  DCHECK_LT(index, length());
28  return Arguments::operator[](index);
29  }
30 
31  template <class S = Object>
32  Handle<S> at(int index) {
33  DCHECK_LT(index, length());
34  return Arguments::at<S>(index);
35  }
36 
37  static constexpr int kNewTargetOffset = 0;
38  static constexpr int kTargetOffset = 1;
39  static constexpr int kArgcOffset = 2;
40  static constexpr int kPaddingOffset = 3;
41 
42  static constexpr int kNumExtraArgs = 4;
43  static constexpr int kNumExtraArgsWithReceiver = 5;
44 
45  inline Handle<Object> atOrUndefined(Isolate* isolate, int index);
46  inline Handle<Object> receiver();
47  inline Handle<JSFunction> target();
48  inline Handle<HeapObject> new_target();
49 
50  // Gets the total number of arguments including the receiver (but
51  // excluding extra arguments).
52  int length() const { return Arguments::length() - kNumExtraArgs; }
53 };
54 
55 // ----------------------------------------------------------------------------
56 // Support macro for defining builtins in C++.
57 // ----------------------------------------------------------------------------
58 //
59 // A builtin function is defined by writing:
60 //
61 // BUILTIN(name) {
62 // ...
63 // }
64 //
65 // In the body of the builtin function the arguments can be accessed
66 // through the BuiltinArguments object args.
67 // TODO(cbruni): add global flag to check whether any tracing events have been
68 // enabled.
69 #define BUILTIN(name) \
70  V8_WARN_UNUSED_RESULT static Object* Builtin_Impl_##name( \
71  BuiltinArguments args, Isolate* isolate); \
72  \
73  V8_NOINLINE static Object* Builtin_Impl_Stats_##name( \
74  int args_length, Address* args_object, Isolate* isolate) { \
75  BuiltinArguments args(args_length, args_object); \
76  RuntimeCallTimerScope timer(isolate, \
77  RuntimeCallCounterId::kBuiltin_##name); \
78  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"), \
79  "V8.Builtin_" #name); \
80  return Builtin_Impl_##name(args, isolate); \
81  } \
82  \
83  V8_WARN_UNUSED_RESULT Object* Builtin_##name( \
84  int args_length, Address* args_object, Isolate* isolate) { \
85  DCHECK(isolate->context().is_null() || isolate->context()->IsContext()); \
86  if (V8_UNLIKELY(FLAG_runtime_stats)) { \
87  return Builtin_Impl_Stats_##name(args_length, args_object, isolate); \
88  } \
89  BuiltinArguments args(args_length, args_object); \
90  return Builtin_Impl_##name(args, isolate); \
91  } \
92  \
93  V8_WARN_UNUSED_RESULT static Object* Builtin_Impl_##name( \
94  BuiltinArguments args, Isolate* isolate)
95 
96 // ----------------------------------------------------------------------------
97 
98 #define CHECK_RECEIVER(Type, name, method) \
99  if (!args.receiver()->Is##Type()) { \
100  THROW_NEW_ERROR_RETURN_FAILURE( \
101  isolate, \
102  NewTypeError(MessageTemplate::kIncompatibleMethodReceiver, \
103  isolate->factory()->NewStringFromAsciiChecked(method), \
104  args.receiver())); \
105  } \
106  Handle<Type> name = Handle<Type>::cast(args.receiver())
107 
108 // Throws a TypeError for {method} if the receiver is not coercible to Object,
109 // or converts the receiver to a String otherwise and assigns it to a new var
110 // with the given {name}.
111 #define TO_THIS_STRING(name, method) \
112  if (args.receiver()->IsNullOrUndefined(isolate)) { \
113  THROW_NEW_ERROR_RETURN_FAILURE( \
114  isolate, \
115  NewTypeError(MessageTemplate::kCalledOnNullOrUndefined, \
116  isolate->factory()->NewStringFromAsciiChecked(method))); \
117  } \
118  Handle<String> name; \
119  ASSIGN_RETURN_FAILURE_ON_EXCEPTION( \
120  isolate, name, Object::ToString(isolate, args.receiver()))
121 
122 } // namespace internal
123 } // namespace v8
124 
125 #endif // V8_BUILTINS_BUILTINS_UTILS_H_
Definition: libplatform.h:13