lib/DebugInfo/CodeView/DebugChecksumsSubsection.cpp

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