1 // Copyright 2021 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/baseline/bytecode-offset-iterator.h"
6
7 #include "src/objects/code-inl.h"
8
9 namespace v8 {
10 namespace internal {
11 namespace baseline {
12
BytecodeOffsetIterator(Handle<ByteArray> mapping_table, Handle<BytecodeArray> bytecodes)13 BytecodeOffsetIterator::BytecodeOffsetIterator(Handle<ByteArray> mapping_table,
14 Handle<BytecodeArray> bytecodes)
15 : mapping_table_(mapping_table),
16 data_start_address_(mapping_table_->GetDataStartAddress()),
17 data_length_(mapping_table_->length()),
18 current_index_(0),
19 bytecode_iterator_(bytecodes),
20 local_heap_(LocalHeap::Current()
21 ? LocalHeap::Current()
22 : Isolate::Current()->main_thread_local_heap()) {
23 local_heap_->AddGCEpilogueCallback(UpdatePointersCallback, this);
24 Initialize();
25 }
26
BytecodeOffsetIterator(ByteArray mapping_table, BytecodeArray bytecodes)27 BytecodeOffsetIterator::BytecodeOffsetIterator(ByteArray mapping_table,
28 BytecodeArray bytecodes)
29 : data_start_address_(mapping_table.GetDataStartAddress()),
30 data_length_(mapping_table.length()),
31 current_index_(0),
32 bytecode_handle_storage_(bytecodes),
33 // In the non-handlified version, no GC is allowed. We use a "dummy"
34 // handle to pass the BytecodeArray to the BytecodeArrayIterator, which
35 // is fine since no objects will be moved.
36 bytecode_iterator_(Handle<BytecodeArray>(
37 reinterpret_cast<Address*>(&bytecode_handle_storage_))),
38 local_heap_(nullptr) {
39 no_gc_.emplace();
40 Initialize();
41 }
42
~BytecodeOffsetIterator()43 BytecodeOffsetIterator::~BytecodeOffsetIterator() {
44 if (local_heap_ != nullptr) {
45 local_heap_->RemoveGCEpilogueCallback(UpdatePointersCallback, this);
46 }
47 }
48
Initialize()49 void BytecodeOffsetIterator::Initialize() {
50 // Initialize values for the prologue.
51 // The first recorded position is at the start of the first bytecode.
52 current_pc_start_offset_ = 0;
53 current_pc_end_offset_ = ReadPosition();
54 current_bytecode_offset_ = kFunctionEntryBytecodeOffset;
55 }
56
UpdatePointers()57 void BytecodeOffsetIterator::UpdatePointers() {
58 DisallowGarbageCollection no_gc;
59 DCHECK(!mapping_table_.is_null());
60 data_start_address_ = mapping_table_->GetDataStartAddress();
61 }
62
63 } // namespace baseline
64 } // namespace internal
65 } // namespace v8
66