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1 // Copyright 2014 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/runtime/runtime-utils.h"
6 
7 #include "src/arguments.h"
8 #include "src/factory.h"
9 #include "src/messages.h"
10 #include "src/objects-inl.h"
11 #include "src/runtime/runtime.h"
12 
13 namespace v8 {
14 namespace internal {
15 
RUNTIME_FUNCTION(Runtime_ArrayBufferGetByteLength)16 RUNTIME_FUNCTION(Runtime_ArrayBufferGetByteLength) {
17   SealHandleScope shs(isolate);
18   DCHECK(args.length() == 1);
19   CONVERT_ARG_CHECKED(JSArrayBuffer, holder, 0);
20   return holder->byte_length();
21 }
22 
23 
RUNTIME_FUNCTION(Runtime_ArrayBufferSliceImpl)24 RUNTIME_FUNCTION(Runtime_ArrayBufferSliceImpl) {
25   HandleScope scope(isolate);
26   DCHECK(args.length() == 4);
27   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, source, 0);
28   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, target, 1);
29   CONVERT_NUMBER_ARG_HANDLE_CHECKED(first, 2);
30   CONVERT_NUMBER_ARG_HANDLE_CHECKED(new_length, 3);
31 
32   if (source->was_neutered() || target->was_neutered()) {
33     THROW_NEW_ERROR_RETURN_FAILURE(
34         isolate, NewTypeError(MessageTemplate::kDetachedOperation,
35                               isolate->factory()->NewStringFromAsciiChecked(
36                                   "ArrayBuffer.prototype.slice")));
37   }
38 
39   CHECK(!source.is_identical_to(target));
40   size_t start = 0, target_length = 0;
41   CHECK(TryNumberToSize(isolate, *first, &start));
42   CHECK(TryNumberToSize(isolate, *new_length, &target_length));
43   CHECK(NumberToSize(isolate, target->byte_length()) >= target_length);
44 
45   if (target_length == 0) return isolate->heap()->undefined_value();
46 
47   size_t source_byte_length = NumberToSize(isolate, source->byte_length());
48   CHECK(start <= source_byte_length);
49   CHECK(source_byte_length - start >= target_length);
50   uint8_t* source_data = reinterpret_cast<uint8_t*>(source->backing_store());
51   uint8_t* target_data = reinterpret_cast<uint8_t*>(target->backing_store());
52   CopyBytes(target_data, source_data + start, target_length);
53   return isolate->heap()->undefined_value();
54 }
55 
56 
RUNTIME_FUNCTION(Runtime_ArrayBufferNeuter)57 RUNTIME_FUNCTION(Runtime_ArrayBufferNeuter) {
58   HandleScope scope(isolate);
59   DCHECK(args.length() == 1);
60   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, array_buffer, 0);
61   if (array_buffer->backing_store() == NULL) {
62     CHECK(Smi::FromInt(0) == array_buffer->byte_length());
63     return isolate->heap()->undefined_value();
64   }
65   // Shared array buffers should never be neutered.
66   CHECK(!array_buffer->is_shared());
67   DCHECK(!array_buffer->is_external());
68   void* backing_store = array_buffer->backing_store();
69   size_t byte_length = NumberToSize(isolate, array_buffer->byte_length());
70   array_buffer->set_is_external(true);
71   isolate->heap()->UnregisterArrayBuffer(*array_buffer);
72   array_buffer->Neuter();
73   isolate->array_buffer_allocator()->Free(backing_store, byte_length);
74   return isolate->heap()->undefined_value();
75 }
76 
77 
ArrayIdToTypeAndSize(int arrayId,ExternalArrayType * array_type,ElementsKind * fixed_elements_kind,size_t * element_size)78 void Runtime::ArrayIdToTypeAndSize(int arrayId, ExternalArrayType* array_type,
79                                    ElementsKind* fixed_elements_kind,
80                                    size_t* element_size) {
81   switch (arrayId) {
82 #define ARRAY_ID_CASE(Type, type, TYPE, ctype, size)      \
83   case ARRAY_ID_##TYPE:                                   \
84     *array_type = kExternal##Type##Array;                 \
85     *fixed_elements_kind = TYPE##_ELEMENTS;               \
86     *element_size = size;                                 \
87     break;
88 
89     TYPED_ARRAYS(ARRAY_ID_CASE)
90 #undef ARRAY_ID_CASE
91 
92     default:
93       UNREACHABLE();
94   }
95 }
96 
97 
RUNTIME_FUNCTION(Runtime_TypedArrayInitialize)98 RUNTIME_FUNCTION(Runtime_TypedArrayInitialize) {
99   HandleScope scope(isolate);
100   DCHECK(args.length() == 6);
101   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
102   CONVERT_SMI_ARG_CHECKED(arrayId, 1);
103   CONVERT_ARG_HANDLE_CHECKED(Object, maybe_buffer, 2);
104   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_offset_object, 3);
105   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_length_object, 4);
106   CONVERT_BOOLEAN_ARG_CHECKED(initialize, 5);
107 
108   CHECK(arrayId >= Runtime::ARRAY_ID_FIRST &&
109         arrayId <= Runtime::ARRAY_ID_LAST);
110 
111   ExternalArrayType array_type = kExternalInt8Array;  // Bogus initialization.
112   size_t element_size = 1;                            // Bogus initialization.
113   ElementsKind fixed_elements_kind = INT8_ELEMENTS;  // Bogus initialization.
114   Runtime::ArrayIdToTypeAndSize(arrayId, &array_type, &fixed_elements_kind,
115                                 &element_size);
116   CHECK(holder->map()->elements_kind() == fixed_elements_kind);
117 
118   size_t byte_offset = 0;
119   size_t byte_length = 0;
120   CHECK(TryNumberToSize(isolate, *byte_offset_object, &byte_offset));
121   CHECK(TryNumberToSize(isolate, *byte_length_object, &byte_length));
122 
123   if (maybe_buffer->IsJSArrayBuffer()) {
124     Handle<JSArrayBuffer> buffer = Handle<JSArrayBuffer>::cast(maybe_buffer);
125     size_t array_buffer_byte_length =
126         NumberToSize(isolate, buffer->byte_length());
127     CHECK(byte_offset <= array_buffer_byte_length);
128     CHECK(array_buffer_byte_length - byte_offset >= byte_length);
129   } else {
130     CHECK(maybe_buffer->IsNull(isolate));
131   }
132 
133   CHECK(byte_length % element_size == 0);
134   size_t length = byte_length / element_size;
135 
136   if (length > static_cast<unsigned>(Smi::kMaxValue)) {
137     THROW_NEW_ERROR_RETURN_FAILURE(
138         isolate, NewRangeError(MessageTemplate::kInvalidTypedArrayLength));
139   }
140 
141   // All checks are done, now we can modify objects.
142 
143   DCHECK_EQ(v8::ArrayBufferView::kInternalFieldCount,
144             holder->GetInternalFieldCount());
145   for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
146     holder->SetInternalField(i, Smi::FromInt(0));
147   }
148   Handle<Object> length_obj = isolate->factory()->NewNumberFromSize(length);
149   holder->set_length(*length_obj);
150   holder->set_byte_offset(*byte_offset_object);
151   holder->set_byte_length(*byte_length_object);
152 
153   if (!maybe_buffer->IsNull(isolate)) {
154     Handle<JSArrayBuffer> buffer = Handle<JSArrayBuffer>::cast(maybe_buffer);
155     holder->set_buffer(*buffer);
156 
157     Handle<FixedTypedArrayBase> elements =
158         isolate->factory()->NewFixedTypedArrayWithExternalPointer(
159             static_cast<int>(length), array_type,
160             static_cast<uint8_t*>(buffer->backing_store()) + byte_offset);
161     holder->set_elements(*elements);
162   } else {
163     Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
164     JSArrayBuffer::Setup(buffer, isolate, true, NULL, byte_length,
165                          SharedFlag::kNotShared);
166     holder->set_buffer(*buffer);
167     Handle<FixedTypedArrayBase> elements =
168         isolate->factory()->NewFixedTypedArray(static_cast<int>(length),
169                                                array_type, initialize);
170     holder->set_elements(*elements);
171   }
172   return isolate->heap()->undefined_value();
173 }
174 
175 
176 // Initializes a typed array from an array-like object.
177 // If an array-like object happens to be a typed array of the same type,
178 // initializes backing store using memove.
179 //
180 // Returns true if backing store was initialized or false otherwise.
RUNTIME_FUNCTION(Runtime_TypedArrayInitializeFromArrayLike)181 RUNTIME_FUNCTION(Runtime_TypedArrayInitializeFromArrayLike) {
182   HandleScope scope(isolate);
183   DCHECK(args.length() == 4);
184   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
185   CONVERT_SMI_ARG_CHECKED(arrayId, 1);
186   CONVERT_ARG_HANDLE_CHECKED(Object, source, 2);
187   CONVERT_NUMBER_ARG_HANDLE_CHECKED(length_obj, 3);
188 
189   CHECK(arrayId >= Runtime::ARRAY_ID_FIRST &&
190         arrayId <= Runtime::ARRAY_ID_LAST);
191 
192   ExternalArrayType array_type = kExternalInt8Array;  // Bogus initialization.
193   size_t element_size = 1;                            // Bogus initialization.
194   ElementsKind fixed_elements_kind = INT8_ELEMENTS;  // Bogus initialization.
195   Runtime::ArrayIdToTypeAndSize(arrayId, &array_type, &fixed_elements_kind,
196                                 &element_size);
197 
198   CHECK(holder->map()->elements_kind() == fixed_elements_kind);
199 
200   Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
201   size_t length = 0;
202   if (source->IsJSTypedArray() &&
203       JSTypedArray::cast(*source)->type() == array_type) {
204     length_obj = handle(JSTypedArray::cast(*source)->length(), isolate);
205     length = JSTypedArray::cast(*source)->length_value();
206   } else {
207     CHECK(TryNumberToSize(isolate, *length_obj, &length));
208   }
209 
210   if ((length > static_cast<unsigned>(Smi::kMaxValue)) ||
211       (length > (kMaxInt / element_size))) {
212     THROW_NEW_ERROR_RETURN_FAILURE(
213         isolate, NewRangeError(MessageTemplate::kInvalidTypedArrayLength));
214   }
215   size_t byte_length = length * element_size;
216 
217   DCHECK_EQ(v8::ArrayBufferView::kInternalFieldCount,
218             holder->GetInternalFieldCount());
219   for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
220     holder->SetInternalField(i, Smi::FromInt(0));
221   }
222 
223   // NOTE: not initializing backing store.
224   // We assume that the caller of this function will initialize holder
225   // with the loop
226   //      for(i = 0; i < length; i++) { holder[i] = source[i]; }
227   // We assume that the caller of this function is always a typed array
228   // constructor.
229   // If source is a typed array, this loop will always run to completion,
230   // so we are sure that the backing store will be initialized.
231   // Otherwise, the indexing operation might throw, so the loop will not
232   // run to completion and the typed array might remain partly initialized.
233   // However we further assume that the caller of this function is a typed array
234   // constructor, and the exception will propagate out of the constructor,
235   // therefore uninitialized memory will not be accessible by a user program.
236   //
237   // TODO(dslomov): revise this once we support subclassing.
238 
239   if (!JSArrayBuffer::SetupAllocatingData(buffer, isolate, byte_length,
240                                           false)) {
241     THROW_NEW_ERROR_RETURN_FAILURE(
242         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
243   }
244 
245   holder->set_buffer(*buffer);
246   holder->set_byte_offset(Smi::FromInt(0));
247   Handle<Object> byte_length_obj(
248       isolate->factory()->NewNumberFromSize(byte_length));
249   holder->set_byte_length(*byte_length_obj);
250   holder->set_length(*length_obj);
251 
252   Handle<FixedTypedArrayBase> elements =
253       isolate->factory()->NewFixedTypedArrayWithExternalPointer(
254           static_cast<int>(length), array_type,
255           static_cast<uint8_t*>(buffer->backing_store()));
256   holder->set_elements(*elements);
257 
258   if (source->IsJSTypedArray()) {
259     Handle<JSTypedArray> typed_array(JSTypedArray::cast(*source));
260 
261     if (typed_array->type() == holder->type()) {
262       uint8_t* backing_store =
263           static_cast<uint8_t*>(typed_array->GetBuffer()->backing_store());
264       size_t source_byte_offset =
265           NumberToSize(isolate, typed_array->byte_offset());
266       memcpy(buffer->backing_store(), backing_store + source_byte_offset,
267              byte_length);
268       return isolate->heap()->true_value();
269     }
270   }
271 
272   return isolate->heap()->false_value();
273 }
274 
275 
276 #define BUFFER_VIEW_GETTER(Type, getter, accessor)   \
277   RUNTIME_FUNCTION(Runtime_##Type##Get##getter) {    \
278     HandleScope scope(isolate);                      \
279     DCHECK_EQ(1, args.length());                     \
280     CONVERT_ARG_HANDLE_CHECKED(JS##Type, holder, 0); \
281     return holder->accessor();                       \
282   }
283 
BUFFER_VIEW_GETTER(ArrayBufferView,ByteLength,byte_length)284 BUFFER_VIEW_GETTER(ArrayBufferView, ByteLength, byte_length)
285 BUFFER_VIEW_GETTER(ArrayBufferView, ByteOffset, byte_offset)
286 BUFFER_VIEW_GETTER(TypedArray, Length, length)
287 
288 #undef BUFFER_VIEW_GETTER
289 
290 RUNTIME_FUNCTION(Runtime_TypedArrayGetBuffer) {
291   HandleScope scope(isolate);
292   DCHECK_EQ(1, args.length());
293   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
294   return *holder->GetBuffer();
295 }
296 
297 
298 // Return codes for Runtime_TypedArraySetFastCases.
299 // Should be synchronized with typedarray.js natives.
300 enum TypedArraySetResultCodes {
301   // Set from typed array of the same type.
302   // This is processed by TypedArraySetFastCases
303   TYPED_ARRAY_SET_TYPED_ARRAY_SAME_TYPE = 0,
304   // Set from typed array of the different type, overlapping in memory.
305   TYPED_ARRAY_SET_TYPED_ARRAY_OVERLAPPING = 1,
306   // Set from typed array of the different type, non-overlapping.
307   TYPED_ARRAY_SET_TYPED_ARRAY_NONOVERLAPPING = 2,
308   // Set from non-typed array.
309   TYPED_ARRAY_SET_NON_TYPED_ARRAY = 3
310 };
311 
312 
RUNTIME_FUNCTION(Runtime_TypedArraySetFastCases)313 RUNTIME_FUNCTION(Runtime_TypedArraySetFastCases) {
314   HandleScope scope(isolate);
315   DCHECK(args.length() == 3);
316   if (!args[0]->IsJSTypedArray()) {
317     THROW_NEW_ERROR_RETURN_FAILURE(
318         isolate, NewTypeError(MessageTemplate::kNotTypedArray));
319   }
320 
321   if (!args[1]->IsJSTypedArray())
322     return Smi::FromInt(TYPED_ARRAY_SET_NON_TYPED_ARRAY);
323 
324   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, target_obj, 0);
325   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, source_obj, 1);
326   CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset_obj, 2);
327 
328   Handle<JSTypedArray> target(JSTypedArray::cast(*target_obj));
329   Handle<JSTypedArray> source(JSTypedArray::cast(*source_obj));
330   size_t offset = 0;
331   CHECK(TryNumberToSize(isolate, *offset_obj, &offset));
332   size_t target_length = target->length_value();
333   size_t source_length = source->length_value();
334   size_t target_byte_length = NumberToSize(isolate, target->byte_length());
335   size_t source_byte_length = NumberToSize(isolate, source->byte_length());
336   if (offset > target_length || offset + source_length > target_length ||
337       offset + source_length < offset) {  // overflow
338     THROW_NEW_ERROR_RETURN_FAILURE(
339         isolate, NewRangeError(MessageTemplate::kTypedArraySetSourceTooLarge));
340   }
341 
342   size_t target_offset = NumberToSize(isolate, target->byte_offset());
343   size_t source_offset = NumberToSize(isolate, source->byte_offset());
344   uint8_t* target_base =
345       static_cast<uint8_t*>(target->GetBuffer()->backing_store()) +
346       target_offset;
347   uint8_t* source_base =
348       static_cast<uint8_t*>(source->GetBuffer()->backing_store()) +
349       source_offset;
350 
351   // Typed arrays of the same type: use memmove.
352   if (target->type() == source->type()) {
353     memmove(target_base + offset * target->element_size(), source_base,
354             source_byte_length);
355     return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_SAME_TYPE);
356   }
357 
358   // Typed arrays of different types over the same backing store
359   if ((source_base <= target_base &&
360        source_base + source_byte_length > target_base) ||
361       (target_base <= source_base &&
362        target_base + target_byte_length > source_base)) {
363     // We do not support overlapping ArrayBuffers
364     DCHECK(target->GetBuffer()->backing_store() ==
365            source->GetBuffer()->backing_store());
366     return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_OVERLAPPING);
367   } else {  // Non-overlapping typed arrays
368     return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_NONOVERLAPPING);
369   }
370 }
371 
372 
RUNTIME_FUNCTION(Runtime_TypedArrayMaxSizeInHeap)373 RUNTIME_FUNCTION(Runtime_TypedArrayMaxSizeInHeap) {
374   DCHECK(args.length() == 0);
375   DCHECK_OBJECT_SIZE(FLAG_typed_array_max_size_in_heap +
376                      FixedTypedArrayBase::kDataOffset);
377   return Smi::FromInt(FLAG_typed_array_max_size_in_heap);
378 }
379 
380 
RUNTIME_FUNCTION(Runtime_IsTypedArray)381 RUNTIME_FUNCTION(Runtime_IsTypedArray) {
382   HandleScope scope(isolate);
383   DCHECK(args.length() == 1);
384   return isolate->heap()->ToBoolean(args[0]->IsJSTypedArray());
385 }
386 
387 
RUNTIME_FUNCTION(Runtime_IsSharedTypedArray)388 RUNTIME_FUNCTION(Runtime_IsSharedTypedArray) {
389   HandleScope scope(isolate);
390   DCHECK(args.length() == 1);
391   return isolate->heap()->ToBoolean(
392       args[0]->IsJSTypedArray() &&
393       JSTypedArray::cast(args[0])->GetBuffer()->is_shared());
394 }
395 
396 
RUNTIME_FUNCTION(Runtime_IsSharedIntegerTypedArray)397 RUNTIME_FUNCTION(Runtime_IsSharedIntegerTypedArray) {
398   HandleScope scope(isolate);
399   DCHECK(args.length() == 1);
400   if (!args[0]->IsJSTypedArray()) {
401     return isolate->heap()->false_value();
402   }
403 
404   Handle<JSTypedArray> obj(JSTypedArray::cast(args[0]));
405   return isolate->heap()->ToBoolean(obj->GetBuffer()->is_shared() &&
406                                     obj->type() != kExternalFloat32Array &&
407                                     obj->type() != kExternalFloat64Array &&
408                                     obj->type() != kExternalUint8ClampedArray);
409 }
410 
411 
RUNTIME_FUNCTION(Runtime_IsSharedInteger32TypedArray)412 RUNTIME_FUNCTION(Runtime_IsSharedInteger32TypedArray) {
413   HandleScope scope(isolate);
414   DCHECK(args.length() == 1);
415   if (!args[0]->IsJSTypedArray()) {
416     return isolate->heap()->false_value();
417   }
418 
419   Handle<JSTypedArray> obj(JSTypedArray::cast(args[0]));
420   return isolate->heap()->ToBoolean(obj->GetBuffer()->is_shared() &&
421                                     obj->type() == kExternalInt32Array);
422 }
423 
424 
NeedToFlipBytes(bool is_little_endian)425 inline static bool NeedToFlipBytes(bool is_little_endian) {
426 #ifdef V8_TARGET_LITTLE_ENDIAN
427   return !is_little_endian;
428 #else
429   return is_little_endian;
430 #endif
431 }
432 
433 
434 template <int n>
CopyBytes(uint8_t * target,uint8_t * source)435 inline void CopyBytes(uint8_t* target, uint8_t* source) {
436   for (int i = 0; i < n; i++) {
437     *(target++) = *(source++);
438   }
439 }
440 
441 
442 template <int n>
FlipBytes(uint8_t * target,uint8_t * source)443 inline void FlipBytes(uint8_t* target, uint8_t* source) {
444   source = source + (n - 1);
445   for (int i = 0; i < n; i++) {
446     *(target++) = *(source--);
447   }
448 }
449 
450 
451 template <typename T>
DataViewGetValue(Isolate * isolate,Handle<JSDataView> data_view,Handle<Object> byte_offset_obj,bool is_little_endian,T * result)452 inline static bool DataViewGetValue(Isolate* isolate,
453                                     Handle<JSDataView> data_view,
454                                     Handle<Object> byte_offset_obj,
455                                     bool is_little_endian, T* result) {
456   size_t byte_offset = 0;
457   if (!TryNumberToSize(isolate, *byte_offset_obj, &byte_offset)) {
458     return false;
459   }
460   Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(data_view->buffer()));
461 
462   size_t data_view_byte_offset =
463       NumberToSize(isolate, data_view->byte_offset());
464   size_t data_view_byte_length =
465       NumberToSize(isolate, data_view->byte_length());
466   if (byte_offset + sizeof(T) > data_view_byte_length ||
467       byte_offset + sizeof(T) < byte_offset) {  // overflow
468     return false;
469   }
470 
471   union Value {
472     T data;
473     uint8_t bytes[sizeof(T)];
474   };
475 
476   Value value;
477   size_t buffer_offset = data_view_byte_offset + byte_offset;
478   DCHECK(NumberToSize(isolate, buffer->byte_length()) >=
479          buffer_offset + sizeof(T));
480   uint8_t* source =
481       static_cast<uint8_t*>(buffer->backing_store()) + buffer_offset;
482   if (NeedToFlipBytes(is_little_endian)) {
483     FlipBytes<sizeof(T)>(value.bytes, source);
484   } else {
485     CopyBytes<sizeof(T)>(value.bytes, source);
486   }
487   *result = value.data;
488   return true;
489 }
490 
491 
492 template <typename T>
DataViewSetValue(Isolate * isolate,Handle<JSDataView> data_view,Handle<Object> byte_offset_obj,bool is_little_endian,T data)493 static bool DataViewSetValue(Isolate* isolate, Handle<JSDataView> data_view,
494                              Handle<Object> byte_offset_obj,
495                              bool is_little_endian, T data) {
496   size_t byte_offset = 0;
497   if (!TryNumberToSize(isolate, *byte_offset_obj, &byte_offset)) {
498     return false;
499   }
500   Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(data_view->buffer()));
501 
502   size_t data_view_byte_offset =
503       NumberToSize(isolate, data_view->byte_offset());
504   size_t data_view_byte_length =
505       NumberToSize(isolate, data_view->byte_length());
506   if (byte_offset + sizeof(T) > data_view_byte_length ||
507       byte_offset + sizeof(T) < byte_offset) {  // overflow
508     return false;
509   }
510 
511   union Value {
512     T data;
513     uint8_t bytes[sizeof(T)];
514   };
515 
516   Value value;
517   value.data = data;
518   size_t buffer_offset = data_view_byte_offset + byte_offset;
519   DCHECK(NumberToSize(isolate, buffer->byte_length()) >=
520          buffer_offset + sizeof(T));
521   uint8_t* target =
522       static_cast<uint8_t*>(buffer->backing_store()) + buffer_offset;
523   if (NeedToFlipBytes(is_little_endian)) {
524     FlipBytes<sizeof(T)>(target, value.bytes);
525   } else {
526     CopyBytes<sizeof(T)>(target, value.bytes);
527   }
528   return true;
529 }
530 
531 
532 #define DATA_VIEW_GETTER(TypeName, Type, Converter)                        \
533   RUNTIME_FUNCTION(Runtime_DataViewGet##TypeName) {                        \
534     HandleScope scope(isolate);                                            \
535     DCHECK(args.length() == 3);                                            \
536     CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);                     \
537     CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset, 1);                          \
538     CONVERT_BOOLEAN_ARG_CHECKED(is_little_endian, 2);                      \
539     Type result;                                                           \
540     if (DataViewGetValue(isolate, holder, offset, is_little_endian,        \
541                          &result)) {                                       \
542       return *isolate->factory()->Converter(result);                       \
543     } else {                                                               \
544       THROW_NEW_ERROR_RETURN_FAILURE(                                      \
545           isolate,                                                         \
546           NewRangeError(MessageTemplate::kInvalidDataViewAccessorOffset)); \
547     }                                                                      \
548   }
549 
550 DATA_VIEW_GETTER(Uint8, uint8_t, NewNumberFromUint)
551 DATA_VIEW_GETTER(Int8, int8_t, NewNumberFromInt)
552 DATA_VIEW_GETTER(Uint16, uint16_t, NewNumberFromUint)
553 DATA_VIEW_GETTER(Int16, int16_t, NewNumberFromInt)
554 DATA_VIEW_GETTER(Uint32, uint32_t, NewNumberFromUint)
555 DATA_VIEW_GETTER(Int32, int32_t, NewNumberFromInt)
556 DATA_VIEW_GETTER(Float32, float, NewNumber)
557 DATA_VIEW_GETTER(Float64, double, NewNumber)
558 
559 #undef DATA_VIEW_GETTER
560 
561 
562 template <typename T>
563 static T DataViewConvertValue(double value);
564 
565 
566 template <>
DataViewConvertValue(double value)567 int8_t DataViewConvertValue<int8_t>(double value) {
568   return static_cast<int8_t>(DoubleToInt32(value));
569 }
570 
571 
572 template <>
DataViewConvertValue(double value)573 int16_t DataViewConvertValue<int16_t>(double value) {
574   return static_cast<int16_t>(DoubleToInt32(value));
575 }
576 
577 
578 template <>
DataViewConvertValue(double value)579 int32_t DataViewConvertValue<int32_t>(double value) {
580   return DoubleToInt32(value);
581 }
582 
583 
584 template <>
DataViewConvertValue(double value)585 uint8_t DataViewConvertValue<uint8_t>(double value) {
586   return static_cast<uint8_t>(DoubleToUint32(value));
587 }
588 
589 
590 template <>
DataViewConvertValue(double value)591 uint16_t DataViewConvertValue<uint16_t>(double value) {
592   return static_cast<uint16_t>(DoubleToUint32(value));
593 }
594 
595 
596 template <>
DataViewConvertValue(double value)597 uint32_t DataViewConvertValue<uint32_t>(double value) {
598   return DoubleToUint32(value);
599 }
600 
601 
602 template <>
DataViewConvertValue(double value)603 float DataViewConvertValue<float>(double value) {
604   return static_cast<float>(value);
605 }
606 
607 
608 template <>
DataViewConvertValue(double value)609 double DataViewConvertValue<double>(double value) {
610   return value;
611 }
612 
613 
614 #define DATA_VIEW_SETTER(TypeName, Type)                                   \
615   RUNTIME_FUNCTION(Runtime_DataViewSet##TypeName) {                        \
616     HandleScope scope(isolate);                                            \
617     DCHECK(args.length() == 4);                                            \
618     CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);                     \
619     CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset, 1);                          \
620     CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);                           \
621     CONVERT_BOOLEAN_ARG_CHECKED(is_little_endian, 3);                      \
622     Type v = DataViewConvertValue<Type>(value->Number());                  \
623     if (DataViewSetValue(isolate, holder, offset, is_little_endian, v)) {  \
624       return isolate->heap()->undefined_value();                           \
625     } else {                                                               \
626       THROW_NEW_ERROR_RETURN_FAILURE(                                      \
627           isolate,                                                         \
628           NewRangeError(MessageTemplate::kInvalidDataViewAccessorOffset)); \
629     }                                                                      \
630   }
631 
632 DATA_VIEW_SETTER(Uint8, uint8_t)
633 DATA_VIEW_SETTER(Int8, int8_t)
634 DATA_VIEW_SETTER(Uint16, uint16_t)
635 DATA_VIEW_SETTER(Int16, int16_t)
636 DATA_VIEW_SETTER(Uint32, uint32_t)
637 DATA_VIEW_SETTER(Int32, int32_t)
638 DATA_VIEW_SETTER(Float32, float)
639 DATA_VIEW_SETTER(Float64, double)
640 
641 #undef DATA_VIEW_SETTER
642 }  // namespace internal
643 }  // namespace v8
644