xref: /llvm-project/llvm/lib/DebugInfo/CodeView/DebugChecksumsSubsection.cpp (revision 591312c5c1a133949285dde012d8cf373ab31b12)
1 //===- DebugChecksumsSubsection.cpp ----------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/DebugInfo/CodeView/DebugChecksumsSubsection.h"
11 
12 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
13 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
14 #include "llvm/Support/BinaryStreamReader.h"
15 
16 using namespace llvm;
17 using namespace llvm::codeview;
18 
19 struct FileChecksumEntryHeader {
20   using ulittle32_t = support::ulittle32_t;
21 
22   ulittle32_t FileNameOffset; // Byte offset of filename in global string table.
23   uint8_t ChecksumSize;       // Number of bytes of checksum.
24   uint8_t ChecksumKind;       // FileChecksumKind
25                               // Checksum bytes follow.
26 };
27 
28 Error llvm::VarStreamArrayExtractor<FileChecksumEntry>::extract(
29     BinaryStreamRef Stream, uint32_t &Len, FileChecksumEntry &Item) {
30   BinaryStreamReader Reader(Stream);
31 
32   const FileChecksumEntryHeader *Header;
33   if (auto EC = Reader.readObject(Header))
34     return EC;
35 
36   Item.FileNameOffset = Header->FileNameOffset;
37   Item.Kind = static_cast<FileChecksumKind>(Header->ChecksumKind);
38   if (auto EC = Reader.readBytes(Item.Checksum, Header->ChecksumSize))
39     return EC;
40 
41   Len = alignTo(Header->ChecksumSize + sizeof(FileChecksumEntryHeader), 4);
42   return Error::success();
43 }
44 
45 Error DebugChecksumsSubsectionRef::initialize(BinaryStreamReader Reader) {
46   if (auto EC = Reader.readArray(Checksums, Reader.bytesRemaining()))
47     return EC;
48 
49   return Error::success();
50 }
51 Error DebugChecksumsSubsectionRef::initialize(BinaryStreamRef Section) {
52   BinaryStreamReader Reader(Section);
53   return initialize(Reader);
54 }
55 
56 DebugChecksumsSubsection::DebugChecksumsSubsection(
57     DebugStringTableSubsection &Strings)
58     : DebugSubsection(DebugSubsectionKind::FileChecksums), Strings(Strings) {}
59 
60 void DebugChecksumsSubsection::addChecksum(StringRef FileName,
61                                            FileChecksumKind Kind,
62                                            ArrayRef<uint8_t> Bytes) {
63   FileChecksumEntry Entry;
64   if (!Bytes.empty()) {
65     uint8_t *Copy = Storage.Allocate<uint8_t>(Bytes.size());
66     ::memcpy(Copy, Bytes.data(), Bytes.size());
67     Entry.Checksum = makeArrayRef(Copy, Bytes.size());
68   }
69 
70   Entry.FileNameOffset = Strings.insert(FileName);
71   Entry.Kind = Kind;
72   Checksums.push_back(Entry);
73 
74   // This maps the offset of this string in the string table to the offset
75   // of this checksum entry in the checksum buffer.
76   OffsetMap[Entry.FileNameOffset] = SerializedSize;
77   assert(SerializedSize % 4 == 0);
78 
79   uint32_t Len = alignTo(sizeof(FileChecksumEntryHeader) + Bytes.size(), 4);
80   SerializedSize += Len;
81 }
82 
83 uint32_t DebugChecksumsSubsection::calculateSerializedSize() const {
84   return SerializedSize;
85 }
86 
87 Error DebugChecksumsSubsection::commit(BinaryStreamWriter &Writer) const {
88   for (const auto &FC : Checksums) {
89     FileChecksumEntryHeader Header;
90     Header.ChecksumKind = uint8_t(FC.Kind);
91     Header.ChecksumSize = FC.Checksum.size();
92     Header.FileNameOffset = FC.FileNameOffset;
93     if (auto EC = Writer.writeObject(Header))
94       return EC;
95     if (auto EC = Writer.writeArray(makeArrayRef(FC.Checksum)))
96       return EC;
97     if (auto EC = Writer.padToAlignment(4))
98       return EC;
99   }
100   return Error::success();
101 }
102 
103 uint32_t DebugChecksumsSubsection::mapChecksumOffset(StringRef FileName) const {
104   uint32_t Offset = Strings.getStringId(FileName);
105   auto Iter = OffsetMap.find(Offset);
106   assert(Iter != OffsetMap.end());
107   return Iter->second;
108 }
109