xref: /llvm-project/llvm/lib/DebugInfo/CodeView/DebugChecksumsSubsection.cpp (revision 8c099fe06e9c4efdea698ac82df2685792ea0b6e)
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/StringTable.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 
52 DebugChecksumsSubsection::DebugChecksumsSubsection(StringTable &Strings)
53     : DebugSubsection(DebugSubsectionKind::FileChecksums), Strings(Strings) {}
54 
55 void DebugChecksumsSubsection::addChecksum(StringRef FileName,
56                                            FileChecksumKind Kind,
57                                            ArrayRef<uint8_t> Bytes) {
58   FileChecksumEntry Entry;
59   if (!Bytes.empty()) {
60     uint8_t *Copy = Storage.Allocate<uint8_t>(Bytes.size());
61     ::memcpy(Copy, Bytes.data(), Bytes.size());
62     Entry.Checksum = makeArrayRef(Copy, Bytes.size());
63   }
64 
65   Entry.FileNameOffset = Strings.insert(FileName);
66   Entry.Kind = Kind;
67   Checksums.push_back(Entry);
68 
69   // This maps the offset of this string in the string table to the offset
70   // of this checksum entry in the checksum buffer.
71   OffsetMap[Entry.FileNameOffset] = SerializedSize;
72   assert(SerializedSize % 4 == 0);
73 
74   uint32_t Len = alignTo(sizeof(FileChecksumEntryHeader) + Bytes.size(), 4);
75   SerializedSize += Len;
76 }
77 
78 uint32_t DebugChecksumsSubsection::calculateSerializedLength() {
79   return SerializedSize;
80 }
81 
82 Error DebugChecksumsSubsection::commit(BinaryStreamWriter &Writer) {
83   for (const auto &FC : Checksums) {
84     FileChecksumEntryHeader Header;
85     Header.ChecksumKind = uint8_t(FC.Kind);
86     Header.ChecksumSize = FC.Checksum.size();
87     Header.FileNameOffset = FC.FileNameOffset;
88     if (auto EC = Writer.writeObject(Header))
89       return EC;
90     if (auto EC = Writer.writeArray(makeArrayRef(FC.Checksum)))
91       return EC;
92     if (auto EC = Writer.padToAlignment(4))
93       return EC;
94   }
95   return Error::success();
96 }
97 
98 uint32_t DebugChecksumsSubsection::mapChecksumOffset(StringRef FileName) const {
99   uint32_t Offset = Strings.getStringId(FileName);
100   auto Iter = OffsetMap.find(Offset);
101   assert(Iter != OffsetMap.end());
102   return Iter->second;
103 }
104