llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp

   1 //===- DebugSubsectionRecord.cpp ------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
  10 #include "llvm/DebugInfo/CodeView/CodeView.h"
  11 #include "llvm/DebugInfo/CodeView/DebugSubsection.h"
  12 #include "llvm/Support/BinaryStreamReader.h"
  13 #include "llvm/Support/BinaryStreamWriter.h"
  14 #include "llvm/Support/Error.h"
  15 #include "llvm/Support/MathExtras.h"
  16 #include <cassert>
  17 #include <cstdint>
  18
  19 using namespace llvm;
  20 using namespace llvm::codeview;
  21
  22 DebugSubsectionRecord::DebugSubsectionRecord() = default;
  23
  24 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
  25                                              BinaryStreamRef Data)
  26     : Kind(Kind), Data(Data) {}
  27
  28 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
  29                                         DebugSubsectionRecord &Info) {
  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.Kind = Kind;
  40   return Error::success();
  41 }
  42
  43 uint32_t DebugSubsectionRecord::getRecordLength() const {
  44   return sizeof(DebugSubsectionHeader) + Data.getLength();
  45 }
  46
  47 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
  48
  49 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
  50
  51 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
  52     std::shared_ptr<DebugSubsection> Subsection)
  53     : Subsection(std::move(Subsection)) {}
  54
  55 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
  56     const DebugSubsectionRecord &Contents)
  57     : Contents(Contents) {}
  58
  59 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() const {
  60   uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
  61                                  : Contents.getRecordData().getLength();
  62   // The length of the entire subsection is always padded to 4 bytes,
  63   // regardless of the container kind.
  64   return sizeof(DebugSubsectionHeader) + alignTo(DataSize, 4);
  65 }
  66
  67 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer,
  68                                            CodeViewContainer Container) const {
  69   assert(Writer.getOffset() % alignOf(Container) == 0 &&
  70          "Debug Subsection not properly aligned");
  71
  72   DebugSubsectionHeader Header;
  73   Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind());
  74   // The value written into the Header's Length field is only padded to the
  75   // container's alignment
  76   uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
  77                                  : Contents.getRecordData().getLength();
  78   Header.Length = alignTo(DataSize, alignOf(Container));
  79
  80   if (auto EC = Writer.writeObject(Header))
  81     return EC;
  82   if (Subsection) {
  83     if (auto EC = Subsection->commit(Writer))
  84       return EC;
  85   } else {
  86     if (auto EC = Writer.writeStreamRef(Contents.getRecordData()))
  87       return EC;
  88   }
  89   if (auto EC = Writer.padToAlignment(4))
  90     return EC;
  91
  92   return Error::success();
  93 }