include/llvm/DebugInfo/CodeView/CVRecord.h

   1 //===- CVRecord.h -----------------------------------------------*- C++ -*-===//
   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 #ifndef LLVM_DEBUGINFO_CODEVIEW_RECORDITERATOR_H
  10 #define LLVM_DEBUGINFO_CODEVIEW_RECORDITERATOR_H
  11
  12 #include "llvm/ADT/ArrayRef.h"
  13 #include "llvm/ADT/Optional.h"
  14 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
  15 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
  16 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
  17 #include "llvm/Support/BinaryStreamReader.h"
  18 #include "llvm/Support/BinaryStreamRef.h"
  19 #include "llvm/Support/Endian.h"
  20 #include "llvm/Support/Error.h"
  21 #include <cstdint>
  22
  23 namespace llvm {
  24
  25 namespace codeview {
  26
  27 /// CVRecord is a fat pointer (base + size pair) to a symbol or type record.
  28 /// Carrying the size separately instead of trusting the size stored in the
  29 /// record prefix provides some extra safety and flexibility.
  30 template <typename Kind> class CVRecord {
  31 public:
  32   CVRecord() = default;
  33
  34   CVRecord(ArrayRef<uint8_t> Data) : RecordData(Data) {}
  35
  36   CVRecord(const RecordPrefix *P, size_t Size)
  37       : RecordData(reinterpret_cast<const uint8_t *>(P), Size) {}
  38
  39   bool valid() const { return kind() != Kind(0); }
  40
  41   uint32_t length() const { return RecordData.size(); }
  42
  43   Kind kind() const {
  44     if (RecordData.size() < sizeof(RecordPrefix))
  45       return Kind(0);
  46     return static_cast<Kind>(static_cast<uint16_t>(
  47         reinterpret_cast<const RecordPrefix *>(RecordData.data())->RecordKind));
  48   }
  49
  50   ArrayRef<uint8_t> data() const { return RecordData; }
  51
  52   StringRef str_data() const {
  53     return StringRef(reinterpret_cast<const char *>(RecordData.data()),
  54                      RecordData.size());
  55   }
  56
  57   ArrayRef<uint8_t> content() const {
  58     return RecordData.drop_front(sizeof(RecordPrefix));
  59   }
  60
  61   ArrayRef<uint8_t> RecordData;
  62 };
  63
  64 template <typename Kind> struct RemappedRecord {
  65   explicit RemappedRecord(const CVRecord<Kind> &R) : OriginalRecord(R) {}
  66
  67   CVRecord<Kind> OriginalRecord;
  68   SmallVector<std::pair<uint32_t, TypeIndex>, 8> Mappings;
  69 };
  70
  71 template <typename Record, typename Func>
  72 Error forEachCodeViewRecord(ArrayRef<uint8_t> StreamBuffer, Func F) {
  73   while (!StreamBuffer.empty()) {
  74     if (StreamBuffer.size() < sizeof(RecordPrefix))
  75       return make_error<CodeViewError>(cv_error_code::corrupt_record);
  76
  77     const RecordPrefix *Prefix =
  78         reinterpret_cast<const RecordPrefix *>(StreamBuffer.data());
  79
  80     size_t RealLen = Prefix->RecordLen + 2;
  81     if (StreamBuffer.size() < RealLen)
  82       return make_error<CodeViewError>(cv_error_code::corrupt_record);
  83
  84     ArrayRef<uint8_t> Data = StreamBuffer.take_front(RealLen);
  85     StreamBuffer = StreamBuffer.drop_front(RealLen);
  86
  87     Record R(Data);
  88     if (auto EC = F(R))
  89       return EC;
  90   }
  91   return Error::success();
  92 }
  93
  94 /// Read a complete record from a stream at a random offset.
  95 template <typename Kind>
  96 inline Expected<CVRecord<Kind>> readCVRecordFromStream(BinaryStreamRef Stream,
  97                                                        uint32_t Offset) {
  98   const RecordPrefix *Prefix = nullptr;
  99   BinaryStreamReader Reader(Stream);
 100   Reader.setOffset(Offset);
 101
 102   if (auto EC = Reader.readObject(Prefix))
 103     return std::move(EC);
 104   if (Prefix->RecordLen < 2)
 105     return make_error<CodeViewError>(cv_error_code::corrupt_record);
 106
 107   Reader.setOffset(Offset);
 108   ArrayRef<uint8_t> RawData;
 109   if (auto EC = Reader.readBytes(RawData, Prefix->RecordLen + sizeof(uint16_t)))
 110     return std::move(EC);
 111   return codeview::CVRecord<Kind>(RawData);
 112 }
 113
 114 } // end namespace codeview
 115
 116 template <typename Kind>
 117 struct VarStreamArrayExtractor<codeview::CVRecord<Kind>> {
 118   Error operator()(BinaryStreamRef Stream, uint32_t &Len,
 119                    codeview::CVRecord<Kind> &Item) {
 120     auto ExpectedRec = codeview::readCVRecordFromStream<Kind>(Stream, 0);
 121     if (!ExpectedRec)
 122       return ExpectedRec.takeError();
 123     Item = *ExpectedRec;
 124     Len = ExpectedRec->length();
 125     return Error::success();
 126   }
 127 };
 128
 129 } // end namespace llvm
 130
 131 #endif // LLVM_DEBUGINFO_CODEVIEW_RECORDITERATOR_H