1 //===- CodeViewRecordIO.cpp -------------------------------------*- 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 #include "llvm/DebugInfo/CodeView/CodeViewRecordIO.h"
11 #include "llvm/DebugInfo/CodeView/CodeView.h"
12 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
13 #include "llvm/Support/BinaryStreamReader.h"
14 #include "llvm/Support/BinaryStreamWriter.h"
15
16 using namespace llvm;
17 using namespace llvm::codeview;
18
beginRecord(Optional<uint32_t> MaxLength)19 Error CodeViewRecordIO::beginRecord(Optional<uint32_t> MaxLength) {
20 RecordLimit Limit;
21 Limit.MaxLength = MaxLength;
22 Limit.BeginOffset = getCurrentOffset();
23 Limits.push_back(Limit);
24 return Error::success();
25 }
26
endRecord()27 Error CodeViewRecordIO::endRecord() {
28 assert(!Limits.empty() && "Not in a record!");
29 Limits.pop_back();
30 // We would like to assert that we actually read / wrote all the bytes that we
31 // expected to for this record, but unfortunately we can't do this. Some
32 // producers such as MASM over-allocate for certain types of records and
33 // commit the extraneous data, so when reading we can't be sure every byte
34 // will have been read. And when writing we over-allocate temporarily since
35 // we don't know how big the record is until we're finished writing it, so
36 // even though we don't commit the extraneous data, we still can't guarantee
37 // we're at the end of the allocated data.
38 return Error::success();
39 }
40
maxFieldLength() const41 uint32_t CodeViewRecordIO::maxFieldLength() const {
42 assert(!Limits.empty() && "Not in a record!");
43
44 // The max length of the next field is the minimum of all lengths that would
45 // be allowed by any of the sub-records we're in. In practice, we can only
46 // ever be at most 1 sub-record deep (in a FieldList), but this works for
47 // the general case.
48 uint32_t Offset = getCurrentOffset();
49 Optional<uint32_t> Min = Limits.front().bytesRemaining(Offset);
50 for (auto X : makeArrayRef(Limits).drop_front()) {
51 Optional<uint32_t> ThisMin = X.bytesRemaining(Offset);
52 if (ThisMin.hasValue())
53 Min = (Min.hasValue()) ? std::min(*Min, *ThisMin) : *ThisMin;
54 }
55 assert(Min.hasValue() && "Every field must have a maximum length!");
56
57 return *Min;
58 }
59
padToAlignment(uint32_t Align)60 Error CodeViewRecordIO::padToAlignment(uint32_t Align) {
61 if (isReading())
62 return Reader->padToAlignment(Align);
63 return Writer->padToAlignment(Align);
64 }
65
skipPadding()66 Error CodeViewRecordIO::skipPadding() {
67 assert(!isWriting() && "Cannot skip padding while writing!");
68
69 if (Reader->bytesRemaining() == 0)
70 return Error::success();
71
72 uint8_t Leaf = Reader->peek();
73 if (Leaf < LF_PAD0)
74 return Error::success();
75 // Leaf is greater than 0xf0. We should advance by the number of bytes in
76 // the low 4 bits.
77 unsigned BytesToAdvance = Leaf & 0x0F;
78 return Reader->skip(BytesToAdvance);
79 }
80
mapByteVectorTail(ArrayRef<uint8_t> & Bytes)81 Error CodeViewRecordIO::mapByteVectorTail(ArrayRef<uint8_t> &Bytes) {
82 if (isWriting()) {
83 if (auto EC = Writer->writeBytes(Bytes))
84 return EC;
85 } else {
86 if (auto EC = Reader->readBytes(Bytes, Reader->bytesRemaining()))
87 return EC;
88 }
89 return Error::success();
90 }
91
mapByteVectorTail(std::vector<uint8_t> & Bytes)92 Error CodeViewRecordIO::mapByteVectorTail(std::vector<uint8_t> &Bytes) {
93 ArrayRef<uint8_t> BytesRef(Bytes);
94 if (auto EC = mapByteVectorTail(BytesRef))
95 return EC;
96 if (!isWriting())
97 Bytes.assign(BytesRef.begin(), BytesRef.end());
98
99 return Error::success();
100 }
101
mapInteger(TypeIndex & TypeInd)102 Error CodeViewRecordIO::mapInteger(TypeIndex &TypeInd) {
103 if (isWriting()) {
104 if (auto EC = Writer->writeInteger(TypeInd.getIndex()))
105 return EC;
106 return Error::success();
107 }
108
109 uint32_t I;
110 if (auto EC = Reader->readInteger(I))
111 return EC;
112 TypeInd.setIndex(I);
113 return Error::success();
114 }
115
mapEncodedInteger(int64_t & Value)116 Error CodeViewRecordIO::mapEncodedInteger(int64_t &Value) {
117 if (isWriting()) {
118 if (Value >= 0) {
119 if (auto EC = writeEncodedUnsignedInteger(static_cast<uint64_t>(Value)))
120 return EC;
121 } else {
122 if (auto EC = writeEncodedSignedInteger(Value))
123 return EC;
124 }
125 } else {
126 APSInt N;
127 if (auto EC = consume(*Reader, N))
128 return EC;
129 Value = N.getExtValue();
130 }
131
132 return Error::success();
133 }
134
mapEncodedInteger(uint64_t & Value)135 Error CodeViewRecordIO::mapEncodedInteger(uint64_t &Value) {
136 if (isWriting()) {
137 if (auto EC = writeEncodedUnsignedInteger(Value))
138 return EC;
139 } else {
140 APSInt N;
141 if (auto EC = consume(*Reader, N))
142 return EC;
143 Value = N.getZExtValue();
144 }
145 return Error::success();
146 }
147
mapEncodedInteger(APSInt & Value)148 Error CodeViewRecordIO::mapEncodedInteger(APSInt &Value) {
149 if (isWriting()) {
150 if (Value.isSigned())
151 return writeEncodedSignedInteger(Value.getSExtValue());
152 return writeEncodedUnsignedInteger(Value.getZExtValue());
153 }
154
155 return consume(*Reader, Value);
156 }
157
mapStringZ(StringRef & Value)158 Error CodeViewRecordIO::mapStringZ(StringRef &Value) {
159 if (isWriting()) {
160 // Truncate if we attempt to write too much.
161 StringRef S = Value.take_front(maxFieldLength() - 1);
162 if (auto EC = Writer->writeCString(S))
163 return EC;
164 } else {
165 if (auto EC = Reader->readCString(Value))
166 return EC;
167 }
168 return Error::success();
169 }
170
mapGuid(GUID & Guid)171 Error CodeViewRecordIO::mapGuid(GUID &Guid) {
172 constexpr uint32_t GuidSize = 16;
173 if (maxFieldLength() < GuidSize)
174 return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
175
176 if (isWriting()) {
177 if (auto EC = Writer->writeBytes(Guid.Guid))
178 return EC;
179 } else {
180 ArrayRef<uint8_t> GuidBytes;
181 if (auto EC = Reader->readBytes(GuidBytes, GuidSize))
182 return EC;
183 memcpy(Guid.Guid, GuidBytes.data(), GuidSize);
184 }
185 return Error::success();
186 }
187
mapStringZVectorZ(std::vector<StringRef> & Value)188 Error CodeViewRecordIO::mapStringZVectorZ(std::vector<StringRef> &Value) {
189 if (isWriting()) {
190 for (auto V : Value) {
191 if (auto EC = mapStringZ(V))
192 return EC;
193 }
194 if (auto EC = Writer->writeInteger<uint8_t>(0))
195 return EC;
196 } else {
197 StringRef S;
198 if (auto EC = mapStringZ(S))
199 return EC;
200 while (!S.empty()) {
201 Value.push_back(S);
202 if (auto EC = mapStringZ(S))
203 return EC;
204 };
205 }
206 return Error::success();
207 }
208
writeEncodedSignedInteger(const int64_t & Value)209 Error CodeViewRecordIO::writeEncodedSignedInteger(const int64_t &Value) {
210 assert(Value < 0 && "Encoded integer is not signed!");
211 if (Value >= std::numeric_limits<int8_t>::min()) {
212 if (auto EC = Writer->writeInteger<uint16_t>(LF_CHAR))
213 return EC;
214 if (auto EC = Writer->writeInteger<int8_t>(Value))
215 return EC;
216 } else if (Value >= std::numeric_limits<int16_t>::min()) {
217 if (auto EC = Writer->writeInteger<uint16_t>(LF_SHORT))
218 return EC;
219 if (auto EC = Writer->writeInteger<int16_t>(Value))
220 return EC;
221 } else if (Value >= std::numeric_limits<int32_t>::min()) {
222 if (auto EC = Writer->writeInteger<uint16_t>(LF_LONG))
223 return EC;
224 if (auto EC = Writer->writeInteger<int32_t>(Value))
225 return EC;
226 } else {
227 if (auto EC = Writer->writeInteger<uint16_t>(LF_QUADWORD))
228 return EC;
229 if (auto EC = Writer->writeInteger(Value))
230 return EC;
231 }
232 return Error::success();
233 }
234
writeEncodedUnsignedInteger(const uint64_t & Value)235 Error CodeViewRecordIO::writeEncodedUnsignedInteger(const uint64_t &Value) {
236 if (Value < LF_NUMERIC) {
237 if (auto EC = Writer->writeInteger<uint16_t>(Value))
238 return EC;
239 } else if (Value <= std::numeric_limits<uint16_t>::max()) {
240 if (auto EC = Writer->writeInteger<uint16_t>(LF_USHORT))
241 return EC;
242 if (auto EC = Writer->writeInteger<uint16_t>(Value))
243 return EC;
244 } else if (Value <= std::numeric_limits<uint32_t>::max()) {
245 if (auto EC = Writer->writeInteger<uint16_t>(LF_ULONG))
246 return EC;
247 if (auto EC = Writer->writeInteger<uint32_t>(Value))
248 return EC;
249 } else {
250 if (auto EC = Writer->writeInteger<uint16_t>(LF_UQUADWORD))
251 return EC;
252 if (auto EC = Writer->writeInteger(Value))
253 return EC;
254 }
255
256 return Error::success();
257 }
258