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      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/factory.h"
     12 #include "src/isolate.h"
     13 
     14 namespace v8 {
     15 namespace internal {
     16 
     17 namespace compiler {
     18 class CodeAssemblerState;
     19 }
     20 
     21 // Arguments object passed to C++ builtins.
     22 class BuiltinArguments : public Arguments {
     23  public:
     24   BuiltinArguments(int length, Object** arguments)
     25       : Arguments(length, arguments) {
     26     // Check we have at least the receiver.
     27     DCHECK_LE(1, this->length());
     28   }
     29 
     30   Object*& operator[](int index) {
     31     DCHECK_LT(index, length());
     32     return Arguments::operator[](index);
     33   }
     34 
     35   template <class S = Object>
     36   Handle<S> at(int index) {
     37     DCHECK_LT(index, length());
     38     return Arguments::at<S>(index);
     39   }
     40 
     41   Handle<Object> atOrUndefined(Isolate* isolate, int index) {
     42     if (index >= length()) {
     43       return isolate->factory()->undefined_value();
     44     }
     45     return at<Object>(index);
     46   }
     47 
     48   Handle<Object> receiver() { return Arguments::at<Object>(0); }
     49 
     50   static const int kNewTargetOffset = 0;
     51   static const int kTargetOffset = 1;
     52   static const int kArgcOffset = 2;
     53   static const int kNumExtraArgs = 3;
     54   static const int kNumExtraArgsWithReceiver = 4;
     55 
     56   Handle<JSFunction> target() {
     57     return Arguments::at<JSFunction>(Arguments::length() - 1 - kTargetOffset);
     58   }
     59   Handle<HeapObject> new_target() {
     60     return Arguments::at<HeapObject>(Arguments::length() - 1 -
     61                                      kNewTargetOffset);
     62   }
     63 
     64   // Gets the total number of arguments including the receiver (but
     65   // excluding extra arguments).
     66   int length() const { return Arguments::length() - kNumExtraArgs; }
     67 };
     68 
     69 // ----------------------------------------------------------------------------
     70 // Support macro for defining builtins in C++.
     71 // ----------------------------------------------------------------------------
     72 //
     73 // A builtin function is defined by writing:
     74 //
     75 //   BUILTIN(name) {
     76 //     ...
     77 //   }
     78 //
     79 // In the body of the builtin function the arguments can be accessed
     80 // through the BuiltinArguments object args.
     81 // TODO(cbruni): add global flag to check whether any tracing events have been
     82 // enabled.
     83 #define BUILTIN(name)                                                         \
     84   MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,   \
     85                                                      Isolate* isolate);       \
     86                                                                               \
     87   V8_NOINLINE static Object* Builtin_Impl_Stats_##name(                       \
     88       int args_length, Object** args_object, Isolate* isolate) {              \
     89     BuiltinArguments args(args_length, args_object);                          \
     90     RuntimeCallTimerScope timer(isolate, &RuntimeCallStats::Builtin_##name);  \
     91     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                     \
     92                  "V8.Builtin_" #name);                                        \
     93     return Builtin_Impl_##name(args, isolate);                                \
     94   }                                                                           \
     95                                                                               \
     96   MUST_USE_RESULT Object* Builtin_##name(                                     \
     97       int args_length, Object** args_object, Isolate* isolate) {              \
     98     DCHECK(isolate->context() == nullptr || isolate->context()->IsContext()); \
     99     if (V8_UNLIKELY(FLAG_runtime_stats)) {                                    \
    100       return Builtin_Impl_Stats_##name(args_length, args_object, isolate);    \
    101     }                                                                         \
    102     BuiltinArguments args(args_length, args_object);                          \
    103     return Builtin_Impl_##name(args, isolate);                                \
    104   }                                                                           \
    105                                                                               \
    106   MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,   \
    107                                                      Isolate* isolate)
    108 
    109 // ----------------------------------------------------------------------------
    110 // Support macro for defining builtins with Turbofan.
    111 // ----------------------------------------------------------------------------
    112 //
    113 // A builtin function is defined by writing:
    114 //
    115 //   TF_BUILTIN(name, code_assember_base_class) {
    116 //     ...
    117 //   }
    118 //
    119 // In the body of the builtin function the arguments can be accessed
    120 // as "Parameter(n)".
    121 #define TF_BUILTIN(Name, AssemblerBase)                                 \
    122   class Name##Assembler : public AssemblerBase {                        \
    123    public:                                                              \
    124     explicit Name##Assembler(compiler::CodeAssemblerState* state)       \
    125         : AssemblerBase(state) {}                                       \
    126     void Generate##Name##Impl();                                        \
    127   };                                                                    \
    128   void Builtins::Generate_##Name(compiler::CodeAssemblerState* state) { \
    129     Name##Assembler assembler(state);                                   \
    130     assembler.Generate##Name##Impl();                                   \
    131   }                                                                     \
    132   void Name##Assembler::Generate##Name##Impl()
    133 
    134 // ----------------------------------------------------------------------------
    135 
    136 #define CHECK_RECEIVER(Type, name, method)                                  \
    137   if (!args.receiver()->Is##Type()) {                                       \
    138     THROW_NEW_ERROR_RETURN_FAILURE(                                         \
    139         isolate,                                                            \
    140         NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,          \
    141                      isolate->factory()->NewStringFromAsciiChecked(method), \
    142                      args.receiver()));                                     \
    143   }                                                                         \
    144   Handle<Type> name = Handle<Type>::cast(args.receiver())
    145 
    146 // Throws a TypeError for {method} if the receiver is not coercible to Object,
    147 // or converts the receiver to a String otherwise and assigns it to a new var
    148 // with the given {name}.
    149 #define TO_THIS_STRING(name, method)                                          \
    150   if (args.receiver()->IsNullOrUndefined(isolate)) {                          \
    151     THROW_NEW_ERROR_RETURN_FAILURE(                                           \
    152         isolate,                                                              \
    153         NewTypeError(MessageTemplate::kCalledOnNullOrUndefined,               \
    154                      isolate->factory()->NewStringFromAsciiChecked(method))); \
    155   }                                                                           \
    156   Handle<String> name;                                                        \
    157   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(                                         \
    158       isolate, name, Object::ToString(isolate, args.receiver()))
    159 
    160 }  // namespace internal
    161 }  // namespace v8
    162 
    163 #endif  // V8_BUILTINS_BUILTINS_UTILS_H_
    164