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 template <typename Kind> class CVRecord {
  28 public:
  29   CVRecord() : Type(static_cast<Kind>(0)) {}
  30
  31   CVRecord(Kind K, ArrayRef<uint8_t> Data) : Type(K), RecordData(Data) {}
  32
  33   bool valid() const { return Type != static_cast<Kind>(0); }
  34
  35   uint32_t length() const { return RecordData.size(); }
  36   Kind kind() const { return Type; }
  37   ArrayRef<uint8_t> data() const { return RecordData; }
  38   StringRef str_data() const {
  39     return StringRef(reinterpret_cast<const char *>(RecordData.data()),
  40                      RecordData.size());
  41   }
  42
  43   ArrayRef<uint8_t> content() const {
  44     return RecordData.drop_front(sizeof(RecordPrefix));
  45   }
  46
  47   Kind Type;
  48   ArrayRef<uint8_t> RecordData;
  49 };
  50
  51 template <typename Kind> struct RemappedRecord {
  52   explicit RemappedRecord(const CVRecord<Kind> &R) : OriginalRecord(R) {}
  53
  54   CVRecord<Kind> OriginalRecord;
  55   SmallVector<std::pair<uint32_t, TypeIndex>, 8> Mappings;
  56 };
  57
  58 template <typename Record, typename Func>
  59 Error forEachCodeViewRecord(ArrayRef<uint8_t> StreamBuffer, Func F) {
  60   while (!StreamBuffer.empty()) {
  61     if (StreamBuffer.size() < sizeof(RecordPrefix))
  62       return make_error<CodeViewError>(cv_error_code::corrupt_record);
  63
  64     const RecordPrefix *Prefix =
  65         reinterpret_cast<const RecordPrefix *>(StreamBuffer.data());
  66
  67     size_t RealLen = Prefix->RecordLen + 2;
  68     if (StreamBuffer.size() < RealLen)
  69       return make_error<CodeViewError>(cv_error_code::corrupt_record);
  70
  71     ArrayRef<uint8_t> Data = StreamBuffer.take_front(RealLen);
  72     StreamBuffer = StreamBuffer.drop_front(RealLen);
  73
  74     Record R(static_cast<decltype(Record::Type)>((uint16_t)Prefix->RecordKind),
  75              Data);
  76     if (auto EC = F(R))
  77       return EC;
  78   }
  79   return Error::success();
  80 }
  81
  82 /// Read a complete record from a stream at a random offset.
  83 template <typename Kind>
  84 inline Expected<CVRecord<Kind>> readCVRecordFromStream(BinaryStreamRef Stream,
  85                                                        uint32_t Offset) {
  86   const RecordPrefix *Prefix = nullptr;
  87   BinaryStreamReader Reader(Stream);
  88   Reader.setOffset(Offset);
  89
  90   if (auto EC = Reader.readObject(Prefix))
  91     return std::move(EC);
  92   if (Prefix->RecordLen < 2)
  93     return make_error<CodeViewError>(cv_error_code::corrupt_record);
  94   Kind K = static_cast<Kind>(uint16_t(Prefix->RecordKind));
  95
  96   Reader.setOffset(Offset);
  97   ArrayRef<uint8_t> RawData;
  98   if (auto EC = Reader.readBytes(RawData, Prefix->RecordLen + sizeof(uint16_t)))
  99     return std::move(EC);
 100   return codeview::CVRecord<Kind>(K, RawData);
 101 }
 102
 103 } // end namespace codeview
 104
 105 template <typename Kind>
 106 struct VarStreamArrayExtractor<codeview::CVRecord<Kind>> {
 107   Error operator()(BinaryStreamRef Stream, uint32_t &Len,
 108                    codeview::CVRecord<Kind> &Item) {
 109     auto ExpectedRec = codeview::readCVRecordFromStream<Kind>(Stream, 0);
 110     if (!ExpectedRec)
 111       return ExpectedRec.takeError();
 112     Item = *ExpectedRec;
 113     Len = ExpectedRec->length();
 114     return Error::success();
 115   }
 116 };
 117
 118 } // end namespace llvm
 119
 120 #endif // LLVM_DEBUGINFO_CODEVIEW_RECORDITERATOR_H