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
CVRecord(ArrayRef<uint8_t> Data)34 CVRecord(ArrayRef<uint8_t> Data) : RecordData(Data) {}
35
CVRecord(const RecordPrefix * P,size_t Size)36 CVRecord(const RecordPrefix *P, size_t Size)
37 : RecordData(reinterpret_cast<const uint8_t *>(P), Size) {}
38
valid()39 bool valid() const { return kind() != Kind(0); }
40
length()41 uint32_t length() const { return RecordData.size(); }
42
kind()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
data()50 ArrayRef<uint8_t> data() const { return RecordData; }
51
str_data()52 StringRef str_data() const {
53 return StringRef(reinterpret_cast<const char *>(RecordData.data()),
54 RecordData.size());
55 }
56
content()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 {
RemappedRecordRemappedRecord65 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>
forEachCodeViewRecord(ArrayRef<uint8_t> StreamBuffer,Func F)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>
readCVRecordFromStream(BinaryStreamRef Stream,uint32_t Offset)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
132