1// Copyright 2018 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 <cstring>
6#include <iomanip>
7
8#include "src/codegen/assembler-inl.h"
9#include "src/codegen/code-comments.h"
10
11namespace v8 {
12namespace internal {
13
14namespace {
15static constexpr uint8_t kOffsetToFirstCommentEntry = kUInt32Size;
16static constexpr uint8_t kOffsetToPCOffset = 0;
17static constexpr uint8_t kOffsetToCommentSize = kOffsetToPCOffset + kUInt32Size;
18static constexpr uint8_t kOffsetToCommentString =
19    kOffsetToCommentSize + kUInt32Size;
20}  // namespace
21
22uint32_t CodeCommentEntry::comment_length() const {
23  return static_cast<uint32_t>(comment.size() + 1);
24}
25
26uint32_t CodeCommentEntry::size() const {
27  return kOffsetToCommentString + comment_length();
28}
29
30CodeCommentsIterator::CodeCommentsIterator(Address code_comments_start,
31                                           uint32_t code_comments_size)
32    : code_comments_start_(code_comments_start),
33      code_comments_size_(code_comments_size),
34      current_entry_(code_comments_start + kOffsetToFirstCommentEntry) {
35  DCHECK_NE(kNullAddress, code_comments_start);
36  DCHECK_IMPLIES(code_comments_size,
37                 code_comments_size ==
38                     base::ReadUnalignedValue<uint32_t>(code_comments_start_));
39}
40
41uint32_t CodeCommentsIterator::size() const { return code_comments_size_; }
42
43const char* CodeCommentsIterator::GetComment() const {
44  const char* comment_string =
45      reinterpret_cast<const char*>(current_entry_ + kOffsetToCommentString);
46  CHECK_EQ(GetCommentSize(), strlen(comment_string) + 1);
47  return comment_string;
48}
49
50uint32_t CodeCommentsIterator::GetCommentSize() const {
51  return ReadUnalignedValue<uint32_t>(current_entry_ + kOffsetToCommentSize);
52}
53
54uint32_t CodeCommentsIterator::GetPCOffset() const {
55  return ReadUnalignedValue<uint32_t>(current_entry_ + kOffsetToPCOffset);
56}
57
58void CodeCommentsIterator::Next() {
59  current_entry_ += kOffsetToCommentString + GetCommentSize();
60}
61
62bool CodeCommentsIterator::HasCurrent() const {
63  return current_entry_ < code_comments_start_ + size();
64}
65
66void CodeCommentsWriter::Emit(Assembler* assm) {
67  assm->dd(section_size());
68  for (auto i = comments_.begin(); i != comments_.end(); ++i) {
69    assm->dd(i->pc_offset);
70    assm->dd(i->comment_length());
71    for (char c : i->comment) {
72      EnsureSpace ensure_space(assm);
73      assm->db(c);
74    }
75    assm->db('\0');
76  }
77}
78
79void CodeCommentsWriter::Add(uint32_t pc_offset, std::string comment) {
80  CodeCommentEntry entry = {pc_offset, std::move(comment)};
81  byte_count_ += entry.size();
82  comments_.push_back(std::move(entry));
83}
84
85size_t CodeCommentsWriter::entry_count() const { return comments_.size(); }
86uint32_t CodeCommentsWriter::section_size() const {
87  return kOffsetToFirstCommentEntry + static_cast<uint32_t>(byte_count_);
88}
89
90}  // namespace internal
91}  // namespace v8
92