contrib/llvm/include/llvm/DebugInfo/CodeView/TypeSerializer.h

   1 //===- TypeSerializer.h -----------------------------------------*- 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 #ifndef LLVM_DEBUGINFO_CODEVIEW_TYPESERIALIZER_H
  11 #define LLVM_DEBUGINFO_CODEVIEW_TYPESERIALIZER_H
  12
  13 #include "llvm/DebugInfo/CodeView/TypeRecordMapping.h"
  14 #include "llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h"
  15 #include "llvm/DebugInfo/MSF/ByteStream.h"
  16 #include "llvm/DebugInfo/MSF/StreamWriter.h"
  17
  18 #include "llvm/ADT/Optional.h"
  19 #include "llvm/ADT/SmallVector.h"
  20 #include "llvm/ADT/StringMap.h"
  21 #include "llvm/ADT/StringRef.h"
  22 #include "llvm/Support/Allocator.h"
  23 #include "llvm/Support/Error.h"
  24
  25 namespace llvm {
  26
  27 namespace codeview {
  28
  29 class TypeSerializer : public TypeVisitorCallbacks {
  30   struct SubRecord {
  31     SubRecord(TypeLeafKind K, uint32_t S) : Kind(K), Size(S) {}
  32
  33     TypeLeafKind Kind;
  34     uint32_t Size = 0;
  35   };
  36   struct RecordSegment {
  37     SmallVector<SubRecord, 16> SubRecords;
  38
  39     uint32_t length() const {
  40       uint32_t L = sizeof(RecordPrefix);
  41       for (const auto &R : SubRecords) {
  42         L += R.Size;
  43       }
  44       return L;
  45     }
  46   };
  47
  48   typedef SmallVector<MutableArrayRef<uint8_t>, 2> RecordList;
  49
  50   static constexpr uint8_t ContinuationLength = 8;
  51   BumpPtrAllocator &RecordStorage;
  52   RecordSegment CurrentSegment;
  53   RecordList FieldListSegments;
  54
  55   TypeIndex LastTypeIndex;
  56   Optional<TypeLeafKind> TypeKind;
  57   Optional<TypeLeafKind> MemberKind;
  58   std::vector<uint8_t> RecordBuffer;
  59   msf::MutableByteStream Stream;
  60   msf::StreamWriter Writer;
  61   TypeRecordMapping Mapping;
  62
  63   RecordList SeenRecords;
  64   StringMap<TypeIndex> HashedRecords;
  65
  66   bool isInFieldList() const;
  67   TypeIndex calcNextTypeIndex() const;
  68   TypeIndex incrementTypeIndex();
  69   MutableArrayRef<uint8_t> getCurrentSubRecordData();
  70   MutableArrayRef<uint8_t> getCurrentRecordData();
  71   Error writeRecordPrefix(TypeLeafKind Kind);
  72   TypeIndex insertRecordBytesPrivate(MutableArrayRef<uint8_t> Record);
  73
  74   Expected<MutableArrayRef<uint8_t>>
  75   addPadding(MutableArrayRef<uint8_t> Record);
  76
  77 public:
  78   explicit TypeSerializer(BumpPtrAllocator &Storage);
  79
  80   ArrayRef<MutableArrayRef<uint8_t>> records() const;
  81   TypeIndex getLastTypeIndex() const;
  82   TypeIndex insertRecordBytes(MutableArrayRef<uint8_t> Record);
  83   Expected<TypeIndex> visitTypeEndGetIndex(CVType &Record);
  84
  85   Error visitTypeBegin(CVType &Record) override;
  86   Error visitTypeEnd(CVType &Record) override;
  87   Error visitMemberBegin(CVMemberRecord &Record) override;
  88   Error visitMemberEnd(CVMemberRecord &Record) override;
  89
  90 #define TYPE_RECORD(EnumName, EnumVal, Name)                                   \
  91   virtual Error visitKnownRecord(CVType &CVR, Name##Record &Record) override { \
  92     return visitKnownRecordImpl(CVR, Record);                                  \
  93   }
  94 #define TYPE_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
  95 #define MEMBER_RECORD(EnumName, EnumVal, Name)                                 \
  96   Error visitKnownMember(CVMemberRecord &CVR, Name##Record &Record) override { \
  97     return visitKnownMemberImpl<Name##Record>(CVR, Record);                    \
  98   }
  99 #define MEMBER_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
 100 #include "llvm/DebugInfo/CodeView/TypeRecords.def"
 101
 102 private:
 103   template <typename RecordKind>
 104   Error visitKnownRecordImpl(CVType &CVR, RecordKind &Record) {
 105     return Mapping.visitKnownRecord(CVR, Record);
 106   }
 107
 108   template <typename RecordType>
 109   Error visitKnownMemberImpl(CVMemberRecord &CVR, RecordType &Record) {
 110     assert(CVR.Kind == static_cast<TypeLeafKind>(Record.getKind()));
 111
 112     if (auto EC = Writer.writeEnum(CVR.Kind))
 113       return EC;
 114
 115     if (auto EC = Mapping.visitKnownMember(CVR, Record))
 116       return EC;
 117
 118     // Get all the data that was just written and is yet to be committed to
 119     // the current segment.  Then pad it to 4 bytes.
 120     MutableArrayRef<uint8_t> ThisRecord = getCurrentSubRecordData();
 121     auto ExpectedRecord = addPadding(ThisRecord);
 122     if (!ExpectedRecord)
 123       return ExpectedRecord.takeError();
 124     ThisRecord = *ExpectedRecord;
 125
 126     CurrentSegment.SubRecords.emplace_back(CVR.Kind, ThisRecord.size());
 127     CVR.Data = ThisRecord;
 128
 129     // Both the last subrecord and the total length of this segment should be
 130     // multiples of 4.
 131     assert(ThisRecord.size() % 4 == 0);
 132     assert(CurrentSegment.length() % 4 == 0);
 133
 134     return Error::success();
 135   }
 136 };
 137 }
 138 }
 139
 140 #endif