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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 #include "src/builtins/builtins-utils.h"
      6 #include "src/builtins/builtins.h"
      7 #include "src/code-stub-assembler.h"
      8 #include "src/counters.h"
      9 #include "src/objects-inl.h"
     10 
     11 namespace v8 {
     12 namespace internal {
     13 
     14 // -----------------------------------------------------------------------------
     15 // ES6 section 19.4 Symbol Objects
     16 
     17 // ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Call]] case.
     18 BUILTIN(SymbolConstructor) {
     19   HandleScope scope(isolate);
     20   Handle<Symbol> result = isolate->factory()->NewSymbol();
     21   Handle<Object> description = args.atOrUndefined(isolate, 1);
     22   if (!description->IsUndefined(isolate)) {
     23     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, description,
     24                                        Object::ToString(isolate, description));
     25     result->set_name(*description);
     26   }
     27   return *result;
     28 }
     29 
     30 // ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Construct]] case.
     31 BUILTIN(SymbolConstructor_ConstructStub) {
     32   HandleScope scope(isolate);
     33   THROW_NEW_ERROR_RETURN_FAILURE(
     34       isolate, NewTypeError(MessageTemplate::kNotConstructor,
     35                             isolate->factory()->Symbol_string()));
     36 }
     37 
     38 // ES6 section 19.4.2.1 Symbol.for.
     39 BUILTIN(SymbolFor) {
     40   HandleScope scope(isolate);
     41   Handle<Object> key_obj = args.atOrUndefined(isolate, 1);
     42   Handle<String> key;
     43   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, key,
     44                                      Object::ToString(isolate, key_obj));
     45   return *isolate->SymbolFor(Heap::kPublicSymbolTableRootIndex, key, false);
     46 }
     47 
     48 // ES6 section 19.4.2.5 Symbol.keyFor.
     49 BUILTIN(SymbolKeyFor) {
     50   HandleScope scope(isolate);
     51   Handle<Object> obj = args.atOrUndefined(isolate, 1);
     52   if (!obj->IsSymbol()) {
     53     THROW_NEW_ERROR_RETURN_FAILURE(
     54         isolate, NewTypeError(MessageTemplate::kSymbolKeyFor, obj));
     55   }
     56   Handle<Symbol> symbol = Handle<Symbol>::cast(obj);
     57   DisallowHeapAllocation no_gc;
     58   Object* result;
     59   if (symbol->is_public()) {
     60     result = symbol->name();
     61     DCHECK(result->IsString());
     62   } else {
     63     result = isolate->heap()->undefined_value();
     64   }
     65   DCHECK_EQ(isolate->heap()->public_symbol_table()->SlowReverseLookup(*symbol),
     66             result);
     67   return result;
     68 }
     69 
     70 // ES6 section 19.4.3.4 Symbol.prototype [ @@toPrimitive ] ( hint )
     71 void Builtins::Generate_SymbolPrototypeToPrimitive(
     72     compiler::CodeAssemblerState* state) {
     73   typedef compiler::Node Node;
     74   CodeStubAssembler assembler(state);
     75 
     76   Node* receiver = assembler.Parameter(0);
     77   Node* context = assembler.Parameter(4);
     78 
     79   Node* result =
     80       assembler.ToThisValue(context, receiver, PrimitiveType::kSymbol,
     81                             "Symbol.prototype [ @@toPrimitive ]");
     82   assembler.Return(result);
     83 }
     84 
     85 // ES6 section 19.4.3.2 Symbol.prototype.toString ( )
     86 void Builtins::Generate_SymbolPrototypeToString(
     87     compiler::CodeAssemblerState* state) {
     88   typedef compiler::Node Node;
     89   CodeStubAssembler assembler(state);
     90 
     91   Node* receiver = assembler.Parameter(0);
     92   Node* context = assembler.Parameter(3);
     93 
     94   Node* value = assembler.ToThisValue(context, receiver, PrimitiveType::kSymbol,
     95                                       "Symbol.prototype.toString");
     96   Node* result =
     97       assembler.CallRuntime(Runtime::kSymbolDescriptiveString, context, value);
     98   assembler.Return(result);
     99 }
    100 
    101 // ES6 section 19.4.3.3 Symbol.prototype.valueOf ( )
    102 void Builtins::Generate_SymbolPrototypeValueOf(
    103     compiler::CodeAssemblerState* state) {
    104   typedef compiler::Node Node;
    105   CodeStubAssembler assembler(state);
    106 
    107   Node* receiver = assembler.Parameter(0);
    108   Node* context = assembler.Parameter(3);
    109 
    110   Node* result = assembler.ToThisValue(
    111       context, receiver, PrimitiveType::kSymbol, "Symbol.prototype.valueOf");
    112   assembler.Return(result);
    113 }
    114 
    115 }  // namespace internal
    116 }  // namespace v8
    117