lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp

   1 //===- DebugSubsectionRecord.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/DebugSubsectionRecord.h"
  11 #include "llvm/DebugInfo/CodeView/CodeView.h"
  12 #include "llvm/DebugInfo/CodeView/DebugSubsection.h"
  13 #include "llvm/Support/BinaryStreamReader.h"
  14 #include "llvm/Support/BinaryStreamWriter.h"
  15 #include "llvm/Support/Error.h"
  16 #include "llvm/Support/MathExtras.h"
  17 #include <algorithm>
  18 #include <cassert>
  19 #include <cstdint>
  20
  21 using namespace llvm;
  22 using namespace llvm::codeview;
  23
  24 DebugSubsectionRecord::DebugSubsectionRecord() = default;
  25
  26 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
  27                                              BinaryStreamRef Data,
  28                                              CodeViewContainer Container)
  29     : Container(Container), Kind(Kind), Data(Data) {}
  30
  31 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
  32                                         DebugSubsectionRecord &Info,
  33                                         CodeViewContainer Container) {
  34   const DebugSubsectionHeader *Header;
  35   BinaryStreamReader Reader(Stream);
  36   if (auto EC = Reader.readObject(Header))
  37     return EC;
  38
  39   DebugSubsectionKind Kind =
  40       static_cast<DebugSubsectionKind>(uint32_t(Header->Kind));
  41   if (auto EC = Reader.readStreamRef(Info.Data, Header->Length))
  42     return EC;
  43   Info.Container = Container;
  44   Info.Kind = Kind;
  45   return Error::success();
  46 }
  47
  48 uint32_t DebugSubsectionRecord::getRecordLength() const {
  49   return sizeof(DebugSubsectionHeader) + Data.getLength();
  50 }
  51
  52 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
  53
  54 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
  55
  56 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
  57     std::shared_ptr<DebugSubsection> Subsection, CodeViewContainer Container)
  58     : Subsection(std::move(Subsection)), Container(Container) {}
  59
  60 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
  61     const DebugSubsectionRecord &Contents, CodeViewContainer Container)
  62     : Contents(Contents), Container(Container) {}
  63
  64 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
  65   uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
  66                                  : Contents.getRecordData().getLength();
  67   // The length of the entire subsection is always padded to 4 bytes,
  68   // regardless of the container kind.
  69   return sizeof(DebugSubsectionHeader) + alignTo(DataSize, 4);
  70 }
  71
  72 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) const {
  73   assert(Writer.getOffset() % alignOf(Container) == 0 &&
  74          "Debug Subsection not properly aligned");
  75
  76   DebugSubsectionHeader Header;
  77   Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind());
  78   // The value written into the Header's Length field is only padded to the
  79   // container's alignment
  80   uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
  81                                  : Contents.getRecordData().getLength();
  82   Header.Length = alignTo(DataSize, alignOf(Container));
  83
  84   if (auto EC = Writer.writeObject(Header))
  85     return EC;
  86   if (Subsection) {
  87     if (auto EC = Subsection->commit(Writer))
  88       return EC;
  89   } else {
  90     if (auto EC = Writer.writeStreamRef(Contents.getRecordData()))
  91       return EC;
  92   }
  93   if (auto EC = Writer.padToAlignment(4))
  94     return EC;
  95
  96   return Error::success();
  97 }