1//===- DebugChecksumsSubsection.cpp ---------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/DebugInfo/CodeView/DebugChecksumsSubsection.h"
10#include "llvm/ADT/ArrayRef.h"
11#include "llvm/DebugInfo/CodeView/CodeView.h"
12#include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
13#include "llvm/Support/BinaryStreamReader.h"
14#include "llvm/Support/BinaryStreamWriter.h"
15#include "llvm/Support/Endian.h"
16#include "llvm/Support/Error.h"
17#include "llvm/Support/MathExtras.h"
18#include <cassert>
19#include <cstdint>
20#include <cstring>
21
22using namespace llvm;
23using namespace llvm::codeview;
24
25struct FileChecksumEntryHeader {
26 using ulittle32_t = support::ulittle32_t;
27
28 ulittle32_t FileNameOffset; // Byte offset of filename in global string table.
29 uint8_t ChecksumSize; // Number of bytes of checksum.
30 uint8_t ChecksumKind; // FileChecksumKind
31 // Checksum bytes follow.
32};
33
34Error VarStreamArrayExtractor<FileChecksumEntry>::
35operator()(BinaryStreamRef Stream, uint32_t &Len, FileChecksumEntry &Item) {
36 BinaryStreamReader Reader(Stream);
37
38 const FileChecksumEntryHeader *Header;
39 if (auto EC = Reader.readObject(Dest&: Header))
40 return EC;
41
42 Item.FileNameOffset = Header->FileNameOffset;
43 Item.Kind = static_cast<FileChecksumKind>(Header->ChecksumKind);
44 if (auto EC = Reader.readBytes(Buffer&: Item.Checksum, Size: Header->ChecksumSize))
45 return EC;
46
47 Len = alignTo(Value: Header->ChecksumSize + sizeof(FileChecksumEntryHeader), Align: 4);
48 return Error::success();
49}
50
51Error DebugChecksumsSubsectionRef::initialize(BinaryStreamReader Reader) {
52 if (auto EC = Reader.readArray(Array&: Checksums, Size: Reader.bytesRemaining()))
53 return EC;
54
55 return Error::success();
56}
57
58Error DebugChecksumsSubsectionRef::initialize(BinaryStreamRef Section) {
59 BinaryStreamReader Reader(Section);
60 return initialize(Reader);
61}
62
63DebugChecksumsSubsection::DebugChecksumsSubsection(
64 DebugStringTableSubsection &Strings)
65 : DebugSubsection(DebugSubsectionKind::FileChecksums), Strings(Strings) {}
66
67void DebugChecksumsSubsection::addChecksum(StringRef FileName,
68 FileChecksumKind Kind,
69 ArrayRef<uint8_t> Bytes) {
70 FileChecksumEntry Entry;
71 if (!Bytes.empty()) {
72 uint8_t *Copy = Storage.Allocate<uint8_t>(Num: Bytes.size());
73 ::memcpy(dest: Copy, src: Bytes.data(), n: Bytes.size());
74 Entry.Checksum = ArrayRef(Copy, Bytes.size());
75 }
76
77 Entry.FileNameOffset = Strings.insert(S: FileName);
78 Entry.Kind = Kind;
79 Checksums.push_back(x: Entry);
80
81 // This maps the offset of this string in the string table to the offset
82 // of this checksum entry in the checksum buffer.
83 OffsetMap[Entry.FileNameOffset] = SerializedSize;
84 assert(SerializedSize % 4 == 0);
85
86 uint32_t Len = alignTo(Value: sizeof(FileChecksumEntryHeader) + Bytes.size(), Align: 4);
87 SerializedSize += Len;
88}
89
90uint32_t DebugChecksumsSubsection::calculateSerializedSize() const {
91 return SerializedSize;
92}
93
94Error DebugChecksumsSubsection::commit(BinaryStreamWriter &Writer) const {
95 for (const auto &FC : Checksums) {
96 FileChecksumEntryHeader Header;
97 Header.ChecksumKind = uint8_t(FC.Kind);
98 Header.ChecksumSize = FC.Checksum.size();
99 Header.FileNameOffset = FC.FileNameOffset;
100 if (auto EC = Writer.writeObject(Obj: Header))
101 return EC;
102 if (auto EC = Writer.writeArray(Array: ArrayRef(FC.Checksum)))
103 return EC;
104 if (auto EC = Writer.padToAlignment(Align: 4))
105 return EC;
106 }
107 return Error::success();
108}
109
110uint32_t DebugChecksumsSubsection::mapChecksumOffset(StringRef FileName) const {
111 uint32_t Offset = Strings.getIdForString(S: FileName);
112 auto Iter = OffsetMap.find(Val: Offset);
113 assert(Iter != OffsetMap.end());
114 return Iter->second;
115}
116