contrib/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp

   1 //===- DebugSubsectionRecord.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/DebugSubsectionRecord.h"
  11 #include "llvm/DebugInfo/CodeView/DebugSubsection.h"
  12
  13 #include "llvm/Support/BinaryStreamReader.h"
  14
  15 using namespace llvm;
  16 using namespace llvm::codeview;
  17
  18 DebugSubsectionRecord::DebugSubsectionRecord()
  19     : Container(CodeViewContainer::ObjectFile),
  20       Kind(DebugSubsectionKind::None) {}
  21
  22 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
  23                                              BinaryStreamRef Data,
  24                                              CodeViewContainer Container)
  25     : Container(Container), Kind(Kind), Data(Data) {}
  26
  27 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
  28                                         DebugSubsectionRecord &Info,
  29                                         CodeViewContainer Container) {
  30   const DebugSubsectionHeader *Header;
  31   BinaryStreamReader Reader(Stream);
  32   if (auto EC = Reader.readObject(Header))
  33     return EC;
  34
  35   DebugSubsectionKind Kind =
  36       static_cast<DebugSubsectionKind>(uint32_t(Header->Kind));
  37   if (auto EC = Reader.readStreamRef(Info.Data, Header->Length))
  38     return EC;
  39   Info.Container = Container;
  40   Info.Kind = Kind;
  41   return Error::success();
  42 }
  43
  44 uint32_t DebugSubsectionRecord::getRecordLength() const {
  45   return sizeof(DebugSubsectionHeader) + Data.getLength();
  46 }
  47
  48 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
  49
  50 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
  51
  52 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
  53     std::shared_ptr<DebugSubsection> Subsection, CodeViewContainer Container)
  54     : Subsection(std::move(Subsection)), Container(Container) {}
  55
  56 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
  57   // The length of the entire subsection is always padded to 4 bytes, regardless
  58   // of the container kind.
  59   uint32_t Size = sizeof(DebugSubsectionHeader) +
  60                   alignTo(Subsection->calculateSerializedSize(), 4);
  61   return Size;
  62 }
  63
  64 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) const {
  65   assert(Writer.getOffset() % alignOf(Container) == 0 &&
  66          "Debug Subsection not properly aligned");
  67
  68   DebugSubsectionHeader Header;
  69   Header.Kind = uint32_t(Subsection->kind());
  70   // The value written into the Header's Length field is only padded to the
  71   // container's alignment
  72   Header.Length =
  73       alignTo(Subsection->calculateSerializedSize(), alignOf(Container));
  74
  75   if (auto EC = Writer.writeObject(Header))
  76     return EC;
  77   if (auto EC = Subsection->commit(Writer))
  78     return EC;
  79   if (auto EC = Writer.padToAlignment(4))
  80     return EC;
  81
  82   return Error::success();
  83 }