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