// Copyright 2024 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --sandbox-testing

const kTypedArrayType = Sandbox.getInstanceTypeIdFor("JS_TYPED_ARRAY_TYPE");
const kTypedArrayByteOffsetOffset =
  Sandbox.getFieldOffset(kTypedArrayType, "byte_offset");
const kTypedArrayByteLengthOffset =
  Sandbox.getFieldOffset(kTypedArrayType, "byte_length");
const kTypedArrayLengthOffset =
  Sandbox.getFieldOffset(kTypedArrayType, "length");
const GB = 1024 * 1024 * 1024;
const kMaxInSandboxBufferSize = 32*GB - 1;
// Something reasonable, must be smaller than the maximum module size.
const kBufferSize = 1 * GB;
// When stored on-heap, these offsets and sizes are left shifted to guarantee
// that they are always smaller than the maximum buffer size.
const kBoundedSizeShift = 29;
const kShiftedBufferSize = BigInt(kBufferSize) << BigInt(kBoundedSizeShift);

let memory = new DataView(new Sandbox.MemoryView(0, 0x100000000));

let array = new Uint8Array(new ArrayBuffer(0));
let array_address = Sandbox.getAddressOf(array);

let byte_offset_address = array_address + kTypedArrayByteOffsetOffset;
memory.setBigUint64(byte_offset_address, 0xffffffffffffffffn, true);
let byte_length_offset_address = array_address + kTypedArrayByteLengthOffset;
memory.setBigUint64(byte_length_offset_address, kShiftedBufferSize, true);
let length_offset_address = array_address + kTypedArrayLengthOffset;
memory.setBigUint64(length_offset_address, kShiftedBufferSize, true);

assertEquals(array.byteOffset, kMaxInSandboxBufferSize);
assertEquals(array.byteLength, kBufferSize);

// WebAssembly.Validate (and similar APIs) will access the TypedArray's data by
// fetching the Data() of the associated ArrayBuffer's BackingStore, then
// adding the ByteOffset(). The Data() of the BackingStore must never be
// nullptr, otherwise we'd end up accessing out-of-sandbox memory.
WebAssembly.validate(array);