Bug Summary

File:lib/DebugInfo/PDB/Native/HashTable.cpp
Warning:line 234, column 16
The left operand of '&' is a garbage value

Annotated Source Code

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/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp

→
1//===- HashTable.cpp - PDB Hash Table -------------------------------------===//
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/PDB/Native/HashTable.h"
11#include "llvm/ADT/Optional.h"
12#include "llvm/DebugInfo/PDB/Native/RawError.h"
13#include "llvm/Support/BinaryStreamReader.h"
14#include "llvm/Support/BinaryStreamWriter.h"
15#include "llvm/Support/Error.h"
16#include "llvm/Support/MathExtras.h"
17#include <algorithm>
18#include <cassert>
19#include <cstdint>
20#include <utility>
21
22using namespace llvm;
23using namespace llvm::pdb;
24
25HashTable::HashTable() : HashTable(8) {}
26
27HashTable::HashTable(uint32_t Capacity) { Buckets.resize(Capacity); }
28
29Error HashTable::load(BinaryStreamReader &Stream) {
30 const Header *H;
31 if (auto EC = Stream.readObject(H))
1
Taking false branch
→
32 return EC;
33 if (H->Capacity == 0)
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
34 return make_error<RawError>(raw_error_code::corrupt_file,
35 "Invalid Hash Table Capacity");
36 if (H->Size > maxLoad(H->Capacity))
4
←
Taking false branch
→
37 return make_error<RawError>(raw_error_code::corrupt_file,
38 "Invalid Hash Table Size");
39
40 Buckets.resize(H->Capacity);
41
42 if (auto EC = readSparseBitVector(Stream, Present))
5
←
Taking false branch
→
43 return EC;
44 if (Present.count() != H->Size)
6
←
Taking false branch
→
45 return make_error<RawError>(raw_error_code::corrupt_file,
46 "Present bit vector does not match size!");
47
48 if (auto EC = readSparseBitVector(Stream, Deleted))
7
←
Calling 'HashTable::readSparseBitVector'
→
49 return EC;
50 if (Present.intersects(Deleted))
51 return make_error<RawError>(raw_error_code::corrupt_file,
52 "Present bit vector interesects deleted!");
53
54 for (uint32_t P : Present) {
55 if (auto EC = Stream.readInteger(Buckets[P].first))
56 return EC;
57 if (auto EC = Stream.readInteger(Buckets[P].second))
58 return EC;
59 }
60
61 return Error::success();
62}
63
64uint32_t HashTable::calculateSerializedLength() const {
65 uint32_t Size = sizeof(Header);
66
67 int NumBitsP = Present.find_last() + 1;
68 int NumBitsD = Deleted.find_last() + 1;
69
70 // Present bit set number of words, followed by that many actual words.
71 Size += sizeof(uint32_t);
72 Size += alignTo(NumBitsP, sizeof(uint32_t));
73
74 // Deleted bit set number of words, followed by that many actual words.
75 Size += sizeof(uint32_t);
76 Size += alignTo(NumBitsD, sizeof(uint32_t));
77
78 // One (Key, Value) pair for each entry Present.
79 Size += 2 * sizeof(uint32_t) * size();
80
81 return Size;
82}
83
84Error HashTable::commit(BinaryStreamWriter &Writer) const {
85 Header H;
86 H.Size = size();
87 H.Capacity = capacity();
88 if (auto EC = Writer.writeObject(H))
89 return EC;
90
91 if (auto EC = writeSparseBitVector(Writer, Present))
92 return EC;
93
94 if (auto EC = writeSparseBitVector(Writer, Deleted))
95 return EC;
96
97 for (const auto &Entry : *this) {
98 if (auto EC = Writer.writeInteger(Entry.first))
99 return EC;
100 if (auto EC = Writer.writeInteger(Entry.second))
101 return EC;
102 }
103 return Error::success();
104}
105
106void HashTable::clear() {
107 Buckets.resize(8);
108 Present.clear();
109 Deleted.clear();
110}
111
112uint32_t HashTable::capacity() const { return Buckets.size(); }
113
114uint32_t HashTable::size() const { return Present.count(); }
115
116HashTableIterator HashTable::begin() const { return HashTableIterator(*this); }
117
118HashTableIterator HashTable::end() const {
119 return HashTableIterator(*this, 0, true);
120}
121
122HashTableIterator HashTable::find(uint32_t K) {
123 uint32_t H = K % capacity();
124 uint32_t I = H;
125 Optional<uint32_t> FirstUnused;
126 do {
127 if (isPresent(I)) {
128 if (Buckets[I].first == K)
129 return HashTableIterator(*this, I, false);
130 } else {
131 if (!FirstUnused)
132 FirstUnused = I;
133 // Insertion occurs via linear probing from the slot hint, and will be
134 // inserted at the first empty / deleted location. Therefore, if we are
135 // probing and find a location that is neither present nor deleted, then
136 // nothing must have EVER been inserted at this location, and thus it is
137 // not possible for a matching value to occur later.
138 if (!isDeleted(I))
139 break;
140 }
141 I = (I + 1) % capacity();
142 } while (I != H);
143
144 // The only way FirstUnused would not be set is if every single entry in the
145 // table were Present. But this would violate the load factor constraints
146 // that we impose, so it should never happen.
147 assert(FirstUnused)(static_cast <bool> (FirstUnused) ? void (0) : __assert_fail
("FirstUnused", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 147, __extension__ __PRETTY_FUNCTION__));
148 return HashTableIterator(*this, *FirstUnused, true);
149}
150
151void HashTable::set(uint32_t K, uint32_t V) {
152 auto Entry = find(K);
153 if (Entry != end()) {
154 assert(isPresent(Entry.index()))(static_cast <bool> (isPresent(Entry.index())) ? void (
0) : __assert_fail ("isPresent(Entry.index())", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 154, __extension__ __PRETTY_FUNCTION__));
155 assert(Buckets[Entry.index()].first == K)(static_cast <bool> (Buckets[Entry.index()].first == K)
? void (0) : __assert_fail ("Buckets[Entry.index()].first == K"
, "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 155, __extension__ __PRETTY_FUNCTION__));
156 // We're updating, no need to do anything special.
157 Buckets[Entry.index()].second = V;
158 return;
159 }
160
161 auto &B = Buckets[Entry.index()];
162 assert(!isPresent(Entry.index()))(static_cast <bool> (!isPresent(Entry.index())) ? void (
0) : __assert_fail ("!isPresent(Entry.index())", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 162, __extension__ __PRETTY_FUNCTION__));
163 assert(Entry.isEnd())(static_cast <bool> (Entry.isEnd()) ? void (0) : __assert_fail
("Entry.isEnd()", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 163, __extension__ __PRETTY_FUNCTION__));
164 B.first = K;
165 B.second = V;
166 Present.set(Entry.index());
167 Deleted.reset(Entry.index());
168
169 grow();
170
171 assert(find(K) != end())(static_cast <bool> (find(K) != end()) ? void (0) : __assert_fail
("find(K) != end()", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 171, __extension__ __PRETTY_FUNCTION__));
172}
173
174void HashTable::remove(uint32_t K) {
175 auto Iter = find(K);
176 // It wasn't here to begin with, just exit.
177 if (Iter == end())
178 return;
179
180 assert(Present.test(Iter.index()))(static_cast <bool> (Present.test(Iter.index())) ? void
(0) : __assert_fail ("Present.test(Iter.index())", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 180, __extension__ __PRETTY_FUNCTION__));
181 assert(!Deleted.test(Iter.index()))(static_cast <bool> (!Deleted.test(Iter.index())) ? void
(0) : __assert_fail ("!Deleted.test(Iter.index())", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 181, __extension__ __PRETTY_FUNCTION__));
182 Deleted.set(Iter.index());
183 Present.reset(Iter.index());
184}
185
186uint32_t HashTable::get(uint32_t K) {
187 auto I = find(K);
188 assert(I != end())(static_cast <bool> (I != end()) ? void (0) : __assert_fail
("I != end()", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 188, __extension__ __PRETTY_FUNCTION__));
189 return (*I).second;
190}
191
192uint32_t HashTable::maxLoad(uint32_t capacity) { return capacity * 2 / 3 + 1; }
193
194void HashTable::grow() {
195 uint32_t S = size();
196 if (S < maxLoad(capacity()))
197 return;
198 assert(capacity() != UINT32_MAX && "Can't grow Hash table!")(static_cast <bool> (capacity() != (4294967295U) &&
"Can't grow Hash table!") ? void (0) : __assert_fail ("capacity() != UINT32_MAX && \"Can't grow Hash table!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 198, __extension__ __PRETTY_FUNCTION__));
199
200 uint32_t NewCapacity =
201 (capacity() <= INT32_MAX(2147483647)) ? capacity() * 2 : UINT32_MAX(4294967295U);
202
203 // Growing requires rebuilding the table and re-hashing every item. Make a
204 // copy with a larger capacity, insert everything into the copy, then swap
205 // it in.
206 HashTable NewMap(NewCapacity);
207 for (auto I : Present) {
208 NewMap.set(Buckets[I].first, Buckets[I].second);
209 }
210
211 Buckets.swap(NewMap.Buckets);
212 std::swap(Present, NewMap.Present);
213 std::swap(Deleted, NewMap.Deleted);
214 assert(capacity() == NewCapacity)(static_cast <bool> (capacity() == NewCapacity) ? void (
0) : __assert_fail ("capacity() == NewCapacity", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 214, __extension__ __PRETTY_FUNCTION__));
215 assert(size() == S)(static_cast <bool> (size() == S) ? void (0) : __assert_fail
("size() == S", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 215, __extension__ __PRETTY_FUNCTION__));
216}
217
218Error HashTable::readSparseBitVector(BinaryStreamReader &Stream,
219 SparseBitVector<> &V) {
220 uint32_t NumWords;
221 if (auto EC = Stream.readInteger(NumWords))
8
←
Taking false branch
→
222 return joinErrors(
223 std::move(EC),
224 make_error<RawError>(raw_error_code::corrupt_file,
225 "Expected hash table number of words"));
226
227 for (uint32_t I = 0; I != NumWords; ++I) {
9
←
Assuming 'I' is not equal to 'NumWords'
→
10
←
Loop condition is true. Entering loop body
→
228 uint32_t Word;
11
←
'Word' declared without an initial value
→
229 if (auto EC = Stream.readInteger(Word))
12
←
Calling 'BinaryStreamReader::readInteger'
→
57
←
Returning from 'BinaryStreamReader::readInteger'
→
58
←
Taking false branch
→
230 return joinErrors(std::move(EC),
231 make_error<RawError>(raw_error_code::corrupt_file,
232 "Expected hash table word"));
233 for (unsigned Idx = 0; Idx < 32; ++Idx)
59
←
Loop condition is true. Entering loop body
→
234 if (Word & (1U << Idx))
60
←
The left operand of '&' is a garbage value
235 V.set((I * 32) + Idx);
236 }
237 return Error::success();
238}
239
240Error HashTable::writeSparseBitVector(BinaryStreamWriter &Writer,
241 SparseBitVector<> &Vec) {
242 int ReqBits = Vec.find_last() + 1;
243 uint32_t NumWords = alignTo(ReqBits, sizeof(uint32_t)) / sizeof(uint32_t);
244 if (auto EC = Writer.writeInteger(NumWords))
245 return joinErrors(
246 std::move(EC),
247 make_error<RawError>(raw_error_code::corrupt_file,
248 "Could not write linear map number of words"));
249
250 uint32_t Idx = 0;
251 for (uint32_t I = 0; I != NumWords; ++I) {
252 uint32_t Word = 0;
253 for (uint32_t WordIdx = 0; WordIdx < 32; ++WordIdx, ++Idx) {
254 if (Vec.test(Idx))
255 Word |= (1 << WordIdx);
256 }
257 if (auto EC = Writer.writeInteger(Word))
258 return joinErrors(std::move(EC), make_error<RawError>(
259 raw_error_code::corrupt_file,
260 "Could not write linear map word"));
261 }
262 return Error::success();
263}
264
265HashTableIterator::HashTableIterator(const HashTable &Map, uint32_t Index,
266 bool IsEnd)
267 : Map(&Map), Index(Index), IsEnd(IsEnd) {}
268
269HashTableIterator::HashTableIterator(const HashTable &Map) : Map(&Map) {
270 int I = Map.Present.find_first();
271 if (I == -1) {
272 Index = 0;
273 IsEnd = true;
274 } else {
275 Index = static_cast<uint32_t>(I);
276 IsEnd = false;
277 }
278}
279
280HashTableIterator &HashTableIterator::operator=(const HashTableIterator &R) {
281 Map = R.Map;
282 return *this;
283}
284
285bool HashTableIterator::operator==(const HashTableIterator &R) const {
286 if (IsEnd && R.IsEnd)
287 return true;
288 if (IsEnd != R.IsEnd)
289 return false;
290
291 return (Map == R.Map) && (Index == R.Index);
292}
293
294const std::pair<uint32_t, uint32_t> &HashTableIterator::operator*() const {
295 assert(Map->Present.test(Index))(static_cast <bool> (Map->Present.test(Index)) ? void
(0) : __assert_fail ("Map->Present.test(Index)", "/build/llvm-toolchain-snapshot-6.0~svn321639/lib/DebugInfo/PDB/Native/HashTable.cpp"
, 295, __extension__ __PRETTY_FUNCTION__));
296 return Map->Buckets[Index];
297}
298
299HashTableIterator &HashTableIterator::operator++() {
300 while (Index < Map->Buckets.size()) {
301 ++Index;
302 if (Map->Present.test(Index))
303 return *this;
304 }
305
306 IsEnd = true;
307 return *this;
308}
←

/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/BinaryStreamReader.h

→
1//===- BinaryStreamReader.h - Reads objects from a binary stream *- 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_SUPPORT_BINARYSTREAMREADER_H
11#define LLVM_SUPPORT_BINARYSTREAMREADER_H
12
13#include "llvm/ADT/ArrayRef.h"
14#include "llvm/ADT/STLExtras.h"
15#include "llvm/Support/BinaryStreamArray.h"
16#include "llvm/Support/BinaryStreamRef.h"
17#include "llvm/Support/ConvertUTF.h"
18#include "llvm/Support/Endian.h"
19#include "llvm/Support/Error.h"
20#include "llvm/Support/type_traits.h"
21
22#include <string>
23#include <type_traits>
24
25namespace llvm {
26
27/// \brief Provides read only access to a subclass of `BinaryStream`. Provides
28/// bounds checking and helpers for writing certain common data types such as
29/// null-terminated strings, integers in various flavors of endianness, etc.
30/// Can be subclassed to provide reading of custom datatypes, although no
31/// are overridable.
32class BinaryStreamReader {
33public:
34 BinaryStreamReader() = default;
35 explicit BinaryStreamReader(BinaryStreamRef Ref);
36 explicit BinaryStreamReader(BinaryStream &Stream);
37 explicit BinaryStreamReader(ArrayRef<uint8_t> Data,
38 llvm::support::endianness Endian);
39 explicit BinaryStreamReader(StringRef Data, llvm::support::endianness Endian);
40
41 BinaryStreamReader(const BinaryStreamReader &Other)
42 : Stream(Other.Stream), Offset(Other.Offset) {}
43
44 BinaryStreamReader &operator=(const BinaryStreamReader &Other) {
45 Stream = Other.Stream;
46 Offset = Other.Offset;
47 return *this;
48 }
49
50 virtual ~BinaryStreamReader() {}
51
52 /// Read as much as possible from the underlying string at the current offset
53 /// without invoking a copy, and set \p Buffer to the resulting data slice.
54 /// Updates the stream's offset to point after the newly read data.
55 ///
56 /// \returns a success error code if the data was successfully read, otherwise
57 /// returns an appropriate error code.
58 Error readLongestContiguousChunk(ArrayRef<uint8_t> &Buffer);
59
60 /// Read \p Size bytes from the underlying stream at the current offset and
61 /// and set \p Buffer to the resulting data slice. Whether a copy occurs
62 /// depends on the implementation of the underlying stream. Updates the
63 /// stream's offset to point after the newly read data.
64 ///
65 /// \returns a success error code if the data was successfully read, otherwise
66 /// returns an appropriate error code.
67 Error readBytes(ArrayRef<uint8_t> &Buffer, uint32_t Size);
68
69 /// Read an integer of the specified endianness into \p Dest and update the
70 /// stream's offset. The data is always copied from the stream's underlying
71 /// buffer into \p Dest. Updates the stream's offset to point after the newly
72 /// read data.
73 ///
74 /// \returns a success error code if the data was successfully read, otherwise
75 /// returns an appropriate error code.
76 template <typename T> Error readInteger(T &Dest) {
77 static_assert(std::is_integral<T>::value,
78 "Cannot call readInteger with non-integral value!");
79
80 ArrayRef<uint8_t> Bytes;
81 if (auto EC = readBytes(Bytes, sizeof(T)))
13
←
Calling move constructor for 'Error'
→
37
←
Returning from move constructor for 'Error'
→
38
←
Calling 'Error::operator bool'
→
47
←
Returning from 'Error::operator bool'
→
48
←
Taking true branch
→
82 return EC;
49
←
Calling '~Error'
→
56
←
Returning from '~Error'
→
83
84 Dest = llvm::support::endian::read<T, llvm::support::unaligned>(
85 Bytes.data(), Stream.getEndian());
86 return Error::success();
87 }
88
89 /// Similar to readInteger.
90 template <typename T> Error readEnum(T &Dest) {
91 static_assert(std::is_enum<T>::value,
92 "Cannot call readEnum with non-enum value!");
93 typename std::underlying_type<T>::type N;
94 if (auto EC = readInteger(N))
95 return EC;
96 Dest = static_cast<T>(N);
97 return Error::success();
98 }
99
100 /// Read a null terminated string from \p Dest. Whether a copy occurs depends
101 /// on the implementation of the underlying stream. Updates the stream's
102 /// offset to point after the newly read data.
103 ///
104 /// \returns a success error code if the data was successfully read, otherwise
105 /// returns an appropriate error code.
106 Error readCString(StringRef &Dest);
107
108 /// Similar to readCString, however read a null-terminated UTF16 string
109 /// instead.
110 ///
111 /// \returns a success error code if the data was successfully read, otherwise
112 /// returns an appropriate error code.
113 Error readWideString(ArrayRef<UTF16> &Dest);
114
115 /// Read a \p Length byte string into \p Dest. Whether a copy occurs depends
116 /// on the implementation of the underlying stream. Updates the stream's
117 /// offset to point after the newly read data.
118 ///
119 /// \returns a success error code if the data was successfully read, otherwise
120 /// returns an appropriate error code.
121 Error readFixedString(StringRef &Dest, uint32_t Length);
122
123 /// Read the entire remainder of the underlying stream into \p Ref. This is
124 /// equivalent to calling getUnderlyingStream().slice(Offset). Updates the
125 /// stream's offset to point to the end of the stream. Never causes a copy.
126 ///
127 /// \returns a success error code if the data was successfully read, otherwise
128 /// returns an appropriate error code.
129 Error readStreamRef(BinaryStreamRef &Ref);
130
131 /// Read \p Length bytes from the underlying stream into \p Ref. This is
132 /// equivalent to calling getUnderlyingStream().slice(Offset, Length).
133 /// Updates the stream's offset to point after the newly read object. Never
134 /// causes a copy.
135 ///
136 /// \returns a success error code if the data was successfully read, otherwise
137 /// returns an appropriate error code.
138 Error readStreamRef(BinaryStreamRef &Ref, uint32_t Length);
139
140 /// Read \p Length bytes from the underlying stream into \p Stream. This is
141 /// equivalent to calling getUnderlyingStream().slice(Offset, Length).
142 /// Updates the stream's offset to point after the newly read object. Never
143 /// causes a copy.
144 ///
145 /// \returns a success error code if the data was successfully read, otherwise
146 /// returns an appropriate error code.
147 Error readSubstream(BinarySubstreamRef &Stream, uint32_t Size);
148
149 /// Get a pointer to an object of type T from the underlying stream, as if by
150 /// memcpy, and store the result into \p Dest. It is up to the caller to
151 /// ensure that objects of type T can be safely treated in this manner.
152 /// Updates the stream's offset to point after the newly read object. Whether
153 /// a copy occurs depends upon the implementation of the underlying
154 /// stream.
155 ///
156 /// \returns a success error code if the data was successfully read, otherwise
157 /// returns an appropriate error code.
158 template <typename T> Error readObject(const T *&Dest) {
159 ArrayRef<uint8_t> Buffer;
160 if (auto EC = readBytes(Buffer, sizeof(T)))
161 return EC;
162 Dest = reinterpret_cast<const T *>(Buffer.data());
163 return Error::success();
164 }
165
166 /// Get a reference to a \p NumElements element array of objects of type T
167 /// from the underlying stream as if by memcpy, and store the resulting array
168 /// slice into \p array. It is up to the caller to ensure that objects of
169 /// type T can be safely treated in this manner. Updates the stream's offset
170 /// to point after the newly read object. Whether a copy occurs depends upon
171 /// the implementation of the underlying stream.
172 ///
173 /// \returns a success error code if the data was successfully read, otherwise
174 /// returns an appropriate error code.
175 template <typename T>
176 Error readArray(ArrayRef<T> &Array, uint32_t NumElements) {
177 ArrayRef<uint8_t> Bytes;
178 if (NumElements == 0) {
179 Array = ArrayRef<T>();
180 return Error::success();
181 }
182
183 if (NumElements > UINT32_MAX(4294967295U) / sizeof(T))
184 return make_error<BinaryStreamError>(
185 stream_error_code::invalid_array_size);
186
187 if (auto EC = readBytes(Bytes, NumElements * sizeof(T)))
188 return EC;
189
190 assert(alignmentAdjustment(Bytes.data(), alignof(T)) == 0 &&(static_cast <bool> (alignmentAdjustment(Bytes.data(), alignof
(T)) == 0 && "Reading at invalid alignment!") ? void (
0) : __assert_fail ("alignmentAdjustment(Bytes.data(), alignof(T)) == 0 && \"Reading at invalid alignment!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/BinaryStreamReader.h"
, 191, __extension__ __PRETTY_FUNCTION__))
191 "Reading at invalid alignment!")(static_cast <bool> (alignmentAdjustment(Bytes.data(), alignof
(T)) == 0 && "Reading at invalid alignment!") ? void (
0) : __assert_fail ("alignmentAdjustment(Bytes.data(), alignof(T)) == 0 && \"Reading at invalid alignment!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/BinaryStreamReader.h"
, 191, __extension__ __PRETTY_FUNCTION__));
192
193 Array = ArrayRef<T>(reinterpret_cast<const T *>(Bytes.data()), NumElements);
194 return Error::success();
195 }
196
197 /// Read a VarStreamArray of size \p Size bytes and store the result into
198 /// \p Array. Updates the stream's offset to point after the newly read
199 /// array. Never causes a copy (although iterating the elements of the
200 /// VarStreamArray may, depending upon the implementation of the underlying
201 /// stream).
202 ///
203 /// \returns a success error code if the data was successfully read, otherwise
204 /// returns an appropriate error code.
205 template <typename T, typename U>
206 Error readArray(VarStreamArray<T, U> &Array, uint32_t Size) {
207 BinaryStreamRef S;
208 if (auto EC = readStreamRef(S, Size))
209 return EC;
210 Array.setUnderlyingStream(S);
211 return Error::success();
212 }
213
214 /// Read a FixedStreamArray of \p NumItems elements and store the result into
215 /// \p Array. Updates the stream's offset to point after the newly read
216 /// array. Never causes a copy (although iterating the elements of the
217 /// FixedStreamArray may, depending upon the implementation of the underlying
218 /// stream).
219 ///
220 /// \returns a success error code if the data was successfully read, otherwise
221 /// returns an appropriate error code.
222 template <typename T>
223 Error readArray(FixedStreamArray<T> &Array, uint32_t NumItems) {
224 if (NumItems == 0) {
225 Array = FixedStreamArray<T>();
226 return Error::success();
227 }
228
229 if (NumItems > UINT32_MAX(4294967295U) / sizeof(T))
230 return make_error<BinaryStreamError>(
231 stream_error_code::invalid_array_size);
232
233 BinaryStreamRef View;
234 if (auto EC = readStreamRef(View, NumItems * sizeof(T)))
235 return EC;
236
237 Array = FixedStreamArray<T>(View);
238 return Error::success();
239 }
240
241 bool empty() const { return bytesRemaining() == 0; }
242 void setOffset(uint32_t Off) { Offset = Off; }
243 uint32_t getOffset() const { return Offset; }
244 uint32_t getLength() const { return Stream.getLength(); }
245 uint32_t bytesRemaining() const { return getLength() - getOffset(); }
246
247 /// Advance the stream's offset by \p Amount bytes.
248 ///
249 /// \returns a success error code if at least \p Amount bytes remain in the
250 /// stream, otherwise returns an appropriate error code.
251 Error skip(uint32_t Amount);
252
253 /// Examine the next byte of the underlying stream without advancing the
254 /// stream's offset. If the stream is empty the behavior is undefined.
255 ///
256 /// \returns the next byte in the stream.
257 uint8_t peek() const;
258
259 Error padToAlignment(uint32_t Align);
260
261 std::pair<BinaryStreamReader, BinaryStreamReader>
262 split(uint32_t Offset) const;
263
264private:
265 BinaryStreamRef Stream;
266 uint32_t Offset = 0;
267};
268} // namespace llvm
269
270#endif // LLVM_SUPPORT_BINARYSTREAMREADER_H
←

/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- 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// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/raw_ostream.h"
28#include <algorithm>
29#include <cassert>
30#include <cstdint>
31#include <cstdlib>
32#include <functional>
33#include <memory>
34#include <new>
35#include <string>
36#include <system_error>
37#include <type_traits>
38#include <utility>
39#include <vector>
40
41namespace llvm {
42
43class ErrorSuccess;
44
45/// Base class for error info classes. Do not extend this directly: Extend
46/// the ErrorInfo template subclass instead.
47class ErrorInfoBase {
48public:
49 virtual ~ErrorInfoBase() = default;
50
51 /// Print an error message to an output stream.
52 virtual void log(raw_ostream &OS) const = 0;
53
54 /// Return the error message as a string.
55 virtual std::string message() const {
56 std::string Msg;
57 raw_string_ostream OS(Msg);
58 log(OS);
59 return OS.str();
60 }
61
62 /// Convert this error to a std::error_code.
63 ///
64 /// This is a temporary crutch to enable interaction with code still
65 /// using std::error_code. It will be removed in the future.
66 virtual std::error_code convertToErrorCode() const = 0;
67
68 // Returns the class ID for this type.
69 static const void *classID() { return &ID; }
70
71 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
72 virtual const void *dynamicClassID() const = 0;
73
74 // Check whether this instance is a subclass of the class identified by
75 // ClassID.
76 virtual bool isA(const void *const ClassID) const {
77 return ClassID == classID();
78 }
79
80 // Check whether this instance is a subclass of ErrorInfoT.
81 template <typename ErrorInfoT> bool isA() const {
82 return isA(ErrorInfoT::classID());
83 }
84
85private:
86 virtual void anchor();
87
88 static char ID;
89};
90
91/// Lightweight error class with error context and mandatory checking.
92///
93/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
94/// are represented by setting the pointer to a ErrorInfoBase subclass
95/// instance containing information describing the failure. Success is
96/// represented by a null pointer value.
97///
98/// Instances of Error also contains a 'Checked' flag, which must be set
99/// before the destructor is called, otherwise the destructor will trigger a
100/// runtime error. This enforces at runtime the requirement that all Error
101/// instances be checked or returned to the caller.
102///
103/// There are two ways to set the checked flag, depending on what state the
104/// Error instance is in. For Error instances indicating success, it
105/// is sufficient to invoke the boolean conversion operator. E.g.:
106///
107/// @code{.cpp}
108/// Error foo(<...>);
109///
110/// if (auto E = foo(<...>))
111/// return E; // <- Return E if it is in the error state.
112/// // We have verified that E was in the success state. It can now be safely
113/// // destroyed.
114/// @endcode
115///
116/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
117/// without testing the return value will raise a runtime error, even if foo
118/// returns success.
119///
120/// For Error instances representing failure, you must use either the
121/// handleErrors or handleAllErrors function with a typed handler. E.g.:
122///
123/// @code{.cpp}
124/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
125/// // Custom error info.
126/// };
127///
128/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
129///
130/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
131/// auto NewE =
132/// handleErrors(E,
133/// [](const MyErrorInfo &M) {
134/// // Deal with the error.
135/// },
136/// [](std::unique_ptr<OtherError> M) -> Error {
137/// if (canHandle(*M)) {
138/// // handle error.
139/// return Error::success();
140/// }
141/// // Couldn't handle this error instance. Pass it up the stack.
142/// return Error(std::move(M));
143/// );
144/// // Note - we must check or return NewE in case any of the handlers
145/// // returned a new error.
146/// @endcode
147///
148/// The handleAllErrors function is identical to handleErrors, except
149/// that it has a void return type, and requires all errors to be handled and
150/// no new errors be returned. It prevents errors (assuming they can all be
151/// handled) from having to be bubbled all the way to the top-level.
152///
153/// *All* Error instances must be checked before destruction, even if
154/// they're moved-assigned or constructed from Success values that have already
155/// been checked. This enforces checking through all levels of the call stack.
156class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
157 // ErrorList needs to be able to yank ErrorInfoBase pointers out of this
158 // class to add to the error list.
159 friend class ErrorList;
160
161 // handleErrors needs to be able to set the Checked flag.
162 template <typename... HandlerTs>
163 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
164
165 // Expected<T> needs to be able to steal the payload when constructed from an
166 // error.
167 template <typename T> friend class Expected;
168
169protected:
170 /// Create a success value. Prefer using 'Error::success()' for readability
171 Error() {
172 setPtr(nullptr);
173 setChecked(false);
174 }
175
176public:
177 /// Create a success value.
178 static ErrorSuccess success();
179
180 // Errors are not copy-constructable.
181 Error(const Error &Other) = delete;
182
183 /// Move-construct an error value. The newly constructed error is considered
184 /// unchecked, even if the source error had been checked. The original error
185 /// becomes a checked Success value, regardless of its original state.
186 Error(Error &&Other) {
187 setChecked(true);
14
←
Calling 'Error::setChecked'
→
16
←
Returning from 'Error::setChecked'
→
188 *this = std::move(Other);
17
←
Calling 'move'
→
18
←
Returning from 'move'
→
19
←
Calling move assignment operator for 'Error'
→
36
←
Returning from move assignment operator for 'Error'
→
189 }
190
191 /// Create an error value. Prefer using the 'make_error' function, but
192 /// this constructor can be useful when "re-throwing" errors from handlers.
193 Error(std::unique_ptr<ErrorInfoBase> Payload) {
194 setPtr(Payload.release());
195 setChecked(false);
196 }
197
198 // Errors are not copy-assignable.
199 Error &operator=(const Error &Other) = delete;
200
201 /// Move-assign an error value. The current error must represent success, you
202 /// you cannot overwrite an unhandled error. The current error is then
203 /// considered unchecked. The source error becomes a checked success value,
204 /// regardless of its original state.
205 Error &operator=(Error &&Other) {
206 // Don't allow overwriting of unchecked values.
207 assertIsChecked();
20
←
Calling 'Error::assertIsChecked'
→
23
←
Returning from 'Error::assertIsChecked'
→
208 setPtr(Other.getPtr());
24
←
Calling 'Error::getPtr'
→
25
←
Returning from 'Error::getPtr'
→
26
←
Calling 'Error::setPtr'
→
27
←
Returning from 'Error::setPtr'
→
209
210 // This Error is unchecked, even if the source error was checked.
211 setChecked(false);
28
←
Calling 'Error::setChecked'
→
30
←
Returning from 'Error::setChecked'
→
212
213 // Null out Other's payload and set its checked bit.
214 Other.setPtr(nullptr);
31
←
Calling 'Error::setPtr'
→
32
←
Returning from 'Error::setPtr'
→
215 Other.setChecked(true);
33
←
Calling 'Error::setChecked'
→
35
←
Returning from 'Error::setChecked'
→
216
217 return *this;
218 }
219
220 /// Destroy a Error. Fails with a call to abort() if the error is
221 /// unchecked.
222 ~Error() {
223 assertIsChecked();
50
←
Calling 'Error::assertIsChecked'
→
53
←
Returning from 'Error::assertIsChecked'
→
224 delete getPtr();
54
←
Calling 'Error::getPtr'
→
55
←
Returning from 'Error::getPtr'
→
225 }
226
227 /// Bool conversion. Returns true if this Error is in a failure state,
228 /// and false if it is in an accept state. If the error is in a Success state
229 /// it will be considered checked.
230 explicit operator bool() {
231 setChecked(getPtr() == nullptr);
39
←
Calling 'Error::getPtr'
→
40
←
Returning from 'Error::getPtr'
→
41
←
Calling 'Error::setChecked'
→
44
←
Returning from 'Error::setChecked'
→
232 return getPtr() != nullptr;
45
←
Calling 'Error::getPtr'
→
46
←
Returning from 'Error::getPtr'
→
233 }
234
235 /// Check whether one error is a subclass of another.
236 template <typename ErrT> bool isA() const {
237 return getPtr() && getPtr()->isA(ErrT::classID());
238 }
239
240 /// Returns the dynamic class id of this error, or null if this is a success
241 /// value.
242 const void* dynamicClassID() const {
243 if (!getPtr())
244 return nullptr;
245 return getPtr()->dynamicClassID();
246 }
247
248private:
249#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
250 // assertIsChecked() happens very frequently, but under normal circumstances
251 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
252 // of debug prints can cause the function to be too large for inlining. So
253 // it's important that we define this function out of line so that it can't be
254 // inlined.
255 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
256 void fatalUncheckedError() const;
257#endif
258
259 void assertIsChecked() {
260#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
261 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
21
←
Within the expansion of the macro 'LLVM_UNLIKELY':
→
a
Calling 'Error::getChecked'
b
Returning from 'Error::getChecked'
c
Calling 'Error::getPtr'
d
Returning from 'Error::getPtr'
22
←
Taking false branch
→
51
←
Within the expansion of the macro 'LLVM_UNLIKELY':
→
a
Calling 'Error::getChecked'
b
Returning from 'Error::getChecked'
52
←
Taking false branch
→
262 fatalUncheckedError();
263#endif
264 }
265
266 ErrorInfoBase *getPtr() const {
267 return reinterpret_cast<ErrorInfoBase*>(
268 reinterpret_cast<uintptr_t>(Payload) &
269 ~static_cast<uintptr_t>(0x1));
270 }
271
272 void setPtr(ErrorInfoBase *EI) {
273#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
274 Payload = reinterpret_cast<ErrorInfoBase*>(
275 (reinterpret_cast<uintptr_t>(EI) &
276 ~static_cast<uintptr_t>(0x1)) |
277 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
278#else
279 Payload = EI;
280#endif
281 }
282
283 bool getChecked() const {
284#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
285 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
286#else
287 return true;
288#endif
289 }
290
291 void setChecked(bool V) {
292 Payload = reinterpret_cast<ErrorInfoBase*>(
293 (reinterpret_cast<uintptr_t>(Payload) &
294 ~static_cast<uintptr_t>(0x1)) |
295 (V ? 0 : 1));
15
←
'?' condition is true
→
29
←
'?' condition is false
→
34
←
'?' condition is true
→
42
←
Assuming 'V' is 0
→
43
←
'?' condition is false
→
296 }
297
298 std::unique_ptr<ErrorInfoBase> takePayload() {
299 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
300 setPtr(nullptr);
301 setChecked(true);
302 return Tmp;
303 }
304
305 ErrorInfoBase *Payload = nullptr;
306};
307
308/// Subclass of Error for the sole purpose of identifying the success path in
309/// the type system. This allows to catch invalid conversion to Expected<T> at
310/// compile time.
311class ErrorSuccess : public Error {};
312
313inline ErrorSuccess Error::success() { return ErrorSuccess(); }
314
315/// Make a Error instance representing failure using the given error info
316/// type.
317template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
318 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
319}
320
321/// Base class for user error types. Users should declare their error types
322/// like:
323///
324/// class MyError : public ErrorInfo<MyError> {
325/// ....
326/// };
327///
328/// This class provides an implementation of the ErrorInfoBase::kind
329/// method, which is used by the Error RTTI system.
330template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
331class ErrorInfo : public ParentErrT {
332public:
333 static const void *classID() { return &ThisErrT::ID; }
334
335 const void *dynamicClassID() const override { return &ThisErrT::ID; }
336
337 bool isA(const void *const ClassID) const override {
338 return ClassID == classID() || ParentErrT::isA(ClassID);
339 }
340};
341
342/// Special ErrorInfo subclass representing a list of ErrorInfos.
343/// Instances of this class are constructed by joinError.
344class ErrorList final : public ErrorInfo<ErrorList> {
345 // handleErrors needs to be able to iterate the payload list of an
346 // ErrorList.
347 template <typename... HandlerTs>
348 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
349
350 // joinErrors is implemented in terms of join.
351 friend Error joinErrors(Error, Error);
352
353public:
354 void log(raw_ostream &OS) const override {
355 OS << "Multiple errors:\n";
356 for (auto &ErrPayload : Payloads) {
357 ErrPayload->log(OS);
358 OS << "\n";
359 }
360 }
361
362 std::error_code convertToErrorCode() const override;
363
364 // Used by ErrorInfo::classID.
365 static char ID;
366
367private:
368 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
369 std::unique_ptr<ErrorInfoBase> Payload2) {
370 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 371, __extension__ __PRETTY_FUNCTION__))
371 "ErrorList constructor payloads should be singleton errors")(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 371, __extension__ __PRETTY_FUNCTION__));
372 Payloads.push_back(std::move(Payload1));
373 Payloads.push_back(std::move(Payload2));
374 }
375
376 static Error join(Error E1, Error E2) {
377 if (!E1)
378 return E2;
379 if (!E2)
380 return E1;
381 if (E1.isA<ErrorList>()) {
382 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
383 if (E2.isA<ErrorList>()) {
384 auto E2Payload = E2.takePayload();
385 auto &E2List = static_cast<ErrorList &>(*E2Payload);
386 for (auto &Payload : E2List.Payloads)
387 E1List.Payloads.push_back(std::move(Payload));
388 } else
389 E1List.Payloads.push_back(E2.takePayload());
390
391 return E1;
392 }
393 if (E2.isA<ErrorList>()) {
394 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
395 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
396 return E2;
397 }
398 return Error(std::unique_ptr<ErrorList>(
399 new ErrorList(E1.takePayload(), E2.takePayload())));
400 }
401
402 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
403};
404
405/// Concatenate errors. The resulting Error is unchecked, and contains the
406/// ErrorInfo(s), if any, contained in E1, followed by the
407/// ErrorInfo(s), if any, contained in E2.
408inline Error joinErrors(Error E1, Error E2) {
409 return ErrorList::join(std::move(E1), std::move(E2));
410}
411
412/// Tagged union holding either a T or a Error.
413///
414/// This class parallels ErrorOr, but replaces error_code with Error. Since
415/// Error cannot be copied, this class replaces getError() with
416/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
417/// error class type.
418template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
419 template <class T1> friend class ExpectedAsOutParameter;
420 template <class OtherT> friend class Expected;
421
422 static const bool isRef = std::is_reference<T>::value;
423
424 using wrap = ReferenceStorage<typename std::remove_reference<T>::type>;
425
426 using error_type = std::unique_ptr<ErrorInfoBase>;
427
428public:
429 using storage_type = typename std::conditional<isRef, wrap, T>::type;
430 using value_type = T;
431
432private:
433 using reference = typename std::remove_reference<T>::type &;
434 using const_reference = const typename std::remove_reference<T>::type &;
435 using pointer = typename std::remove_reference<T>::type *;
436 using const_pointer = const typename std::remove_reference<T>::type *;
437
438public:
439 /// Create an Expected<T> error value from the given Error.
440 Expected(Error Err)
441 : HasError(true)
442#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
443 // Expected is unchecked upon construction in Debug builds.
444 , Unchecked(true)
445#endif
446 {
447 assert(Err && "Cannot create Expected<T> from Error success value.")(static_cast <bool> (Err && "Cannot create Expected<T> from Error success value."
) ? void (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 447, __extension__ __PRETTY_FUNCTION__));
448 new (getErrorStorage()) error_type(Err.takePayload());
449 }
450
451 /// Forbid to convert from Error::success() implicitly, this avoids having
452 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
453 /// but triggers the assertion above.
454 Expected(ErrorSuccess) = delete;
455
456 /// Create an Expected<T> success value from the given OtherT value, which
457 /// must be convertible to T.
458 template <typename OtherT>
459 Expected(OtherT &&Val,
460 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
461 * = nullptr)
462 : HasError(false)
463#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
464 // Expected is unchecked upon construction in Debug builds.
465 , Unchecked(true)
466#endif
467 {
468 new (getStorage()) storage_type(std::forward<OtherT>(Val));
469 }
470
471 /// Move construct an Expected<T> value.
472 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
473
474 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
475 /// must be convertible to T.
476 template <class OtherT>
477 Expected(Expected<OtherT> &&Other,
478 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
479 * = nullptr) {
480 moveConstruct(std::move(Other));
481 }
482
483 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
484 /// isn't convertible to T.
485 template <class OtherT>
486 explicit Expected(
487 Expected<OtherT> &&Other,
488 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
489 nullptr) {
490 moveConstruct(std::move(Other));
491 }
492
493 /// Move-assign from another Expected<T>.
494 Expected &operator=(Expected &&Other) {
495 moveAssign(std::move(Other));
496 return *this;
497 }
498
499 /// Destroy an Expected<T>.
500 ~Expected() {
501 assertIsChecked();
502 if (!HasError)
503 getStorage()->~storage_type();
504 else
505 getErrorStorage()->~error_type();
506 }
507
508 /// \brief Return false if there is an error.
509 explicit operator bool() {
510#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
511 Unchecked = HasError;
512#endif
513 return !HasError;
514 }
515
516 /// \brief Returns a reference to the stored T value.
517 reference get() {
518 assertIsChecked();
519 return *getStorage();
520 }
521
522 /// \brief Returns a const reference to the stored T value.
523 const_reference get() const {
524 assertIsChecked();
525 return const_cast<Expected<T> *>(this)->get();
526 }
527
528 /// \brief Check that this Expected<T> is an error of type ErrT.
529 template <typename ErrT> bool errorIsA() const {
530 return HasError && (*getErrorStorage())->template isA<ErrT>();
531 }
532
533 /// \brief Take ownership of the stored error.
534 /// After calling this the Expected<T> is in an indeterminate state that can
535 /// only be safely destructed. No further calls (beside the destructor) should
536 /// be made on the Expected<T> vaule.
537 Error takeError() {
538#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
539 Unchecked = false;
540#endif
541 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
542 }
543
544 /// \brief Returns a pointer to the stored T value.
545 pointer operator->() {
546 assertIsChecked();
547 return toPointer(getStorage());
548 }
549
550 /// \brief Returns a const pointer to the stored T value.
551 const_pointer operator->() const {
552 assertIsChecked();
553 return toPointer(getStorage());
554 }
555
556 /// \brief Returns a reference to the stored T value.
557 reference operator*() {
558 assertIsChecked();
559 return *getStorage();
560 }
561
562 /// \brief Returns a const reference to the stored T value.
563 const_reference operator*() const {
564 assertIsChecked();
565 return *getStorage();
566 }
567
568private:
569 template <class T1>
570 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
571 return &a == &b;
572 }
573
574 template <class T1, class T2>
575 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
576 return false;
577 }
578
579 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
580 HasError = Other.HasError;
581#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
582 Unchecked = true;
583 Other.Unchecked = false;
584#endif
585
586 if (!HasError)
587 new (getStorage()) storage_type(std::move(*Other.getStorage()));
588 else
589 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
590 }
591
592 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
593 assertIsChecked();
594
595 if (compareThisIfSameType(*this, Other))
596 return;
597
598 this->~Expected();
599 new (this) Expected(std::move(Other));
600 }
601
602 pointer toPointer(pointer Val) { return Val; }
603
604 const_pointer toPointer(const_pointer Val) const { return Val; }
605
606 pointer toPointer(wrap *Val) { return &Val->get(); }
607
608 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
609
610 storage_type *getStorage() {
611 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 611, __extension__ __PRETTY_FUNCTION__));
612 return reinterpret_cast<storage_type *>(TStorage.buffer);
613 }
614
615 const storage_type *getStorage() const {
616 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 616, __extension__ __PRETTY_FUNCTION__));
617 return reinterpret_cast<const storage_type *>(TStorage.buffer);
618 }
619
620 error_type *getErrorStorage() {
621 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 621, __extension__ __PRETTY_FUNCTION__));
622 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
623 }
624
625 const error_type *getErrorStorage() const {
626 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 626, __extension__ __PRETTY_FUNCTION__));
627 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
628 }
629
630 // Used by ExpectedAsOutParameter to reset the checked flag.
631 void setUnchecked() {
632#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
633 Unchecked = true;
634#endif
635 }
636
637#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
638 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
639 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
640 void fatalUncheckedExpected() const {
641 dbgs() << "Expected<T> must be checked before access or destruction.\n";
642 if (HasError) {
643 dbgs() << "Unchecked Expected<T> contained error:\n";
644 (*getErrorStorage())->log(dbgs());
645 } else
646 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
647 "values in success mode must still be checked prior to being "
648 "destroyed).\n";
649 abort();
650 }
651#endif
652
653 void assertIsChecked() {
654#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
655 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
656 fatalUncheckedExpected();
657#endif
658 }
659
660 union {
661 AlignedCharArrayUnion<storage_type> TStorage;
662 AlignedCharArrayUnion<error_type> ErrorStorage;
663 };
664 bool HasError : 1;
665#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
666 bool Unchecked : 1;
667#endif
668};
669
670/// Report a serious error, calling any installed error handler. See
671/// ErrorHandling.h.
672LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
673 bool gen_crash_diag = true);
674
675/// Report a fatal error if Err is a failure value.
676///
677/// This function can be used to wrap calls to fallible functions ONLY when it
678/// is known that the Error will always be a success value. E.g.
679///
680/// @code{.cpp}
681/// // foo only attempts the fallible operation if DoFallibleOperation is
682/// // true. If DoFallibleOperation is false then foo always returns
683/// // Error::success().
684/// Error foo(bool DoFallibleOperation);
685///
686/// cantFail(foo(false));
687/// @endcode
688inline void cantFail(Error Err, const char *Msg = nullptr) {
689 if (Err) {
690 if (!Msg)
691 Msg = "Failure value returned from cantFail wrapped call";
692 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 692);
693 }
694}
695
696/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
697/// returns the contained value.
698///
699/// This function can be used to wrap calls to fallible functions ONLY when it
700/// is known that the Error will always be a success value. E.g.
701///
702/// @code{.cpp}
703/// // foo only attempts the fallible operation if DoFallibleOperation is
704/// // true. If DoFallibleOperation is false then foo always returns an int.
705/// Expected<int> foo(bool DoFallibleOperation);
706///
707/// int X = cantFail(foo(false));
708/// @endcode
709template <typename T>
710T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
711 if (ValOrErr)
712 return std::move(*ValOrErr);
713 else {
714 if (!Msg)
715 Msg = "Failure value returned from cantFail wrapped call";
716 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 716);
717 }
718}
719
720/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
721/// returns the contained reference.
722///
723/// This function can be used to wrap calls to fallible functions ONLY when it
724/// is known that the Error will always be a success value. E.g.
725///
726/// @code{.cpp}
727/// // foo only attempts the fallible operation if DoFallibleOperation is
728/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
729/// Expected<Bar&> foo(bool DoFallibleOperation);
730///
731/// Bar &X = cantFail(foo(false));
732/// @endcode
733template <typename T>
734T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
735 if (ValOrErr)
736 return *ValOrErr;
737 else {
738 if (!Msg)
739 Msg = "Failure value returned from cantFail wrapped call";
740 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 740);
741 }
742}
743
744/// Helper for testing applicability of, and applying, handlers for
745/// ErrorInfo types.
746template <typename HandlerT>
747class ErrorHandlerTraits
748 : public ErrorHandlerTraits<decltype(
749 &std::remove_reference<HandlerT>::type::operator())> {};
750
751// Specialization functions of the form 'Error (const ErrT&)'.
752template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
753public:
754 static bool appliesTo(const ErrorInfoBase &E) {
755 return E.template isA<ErrT>();
756 }
757
758 template <typename HandlerT>
759 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
760 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 760, __extension__ __PRETTY_FUNCTION__));
761 return H(static_cast<ErrT &>(*E));
762 }
763};
764
765// Specialization functions of the form 'void (const ErrT&)'.
766template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
767public:
768 static bool appliesTo(const ErrorInfoBase &E) {
769 return E.template isA<ErrT>();
770 }
771
772 template <typename HandlerT>
773 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
774 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 774, __extension__ __PRETTY_FUNCTION__));
775 H(static_cast<ErrT &>(*E));
776 return Error::success();
777 }
778};
779
780/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
781template <typename ErrT>
782class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 790, __extension__ __PRETTY_FUNCTION__));
791 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
792 return H(std::move(SubE));
793 }
794};
795
796/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-6.0~svn321639/include/llvm/Support/Error.h"
, 806, __extension__ __PRETTY_FUNCTION__));
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 H(std::move(SubE));
809 return Error::success();
810 }
811};
812
813// Specialization for member functions of the form 'RetT (const ErrT&)'.
814template <typename C, typename RetT, typename ErrT>
815class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
816 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
817
818// Specialization for member functions of the form 'RetT (const ErrT&) const'.
819template <typename C, typename RetT, typename ErrT>
820class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
821 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
822
823// Specialization for member functions of the form 'RetT (const ErrT&)'.
824template <typename C, typename RetT, typename ErrT>
825class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
826 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
827
828// Specialization for member functions of the form 'RetT (const ErrT&) const'.
829template <typename C, typename RetT, typename ErrT>
830class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
831 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
832
833/// Specialization for member functions of the form
834/// 'RetT (std::unique_ptr<ErrT>)'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
837 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
838
839/// Specialization for member functions of the form
840/// 'RetT (std::unique_ptr<ErrT>) const'.
841template <typename C, typename RetT, typename ErrT>
842class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
843 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
844
845inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
846 return Error(std::move(Payload));
847}
848
849template <typename HandlerT, typename... HandlerTs>
850Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
851 HandlerT &&Handler, HandlerTs &&... Handlers) {
852 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
853 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
854 std::move(Payload));
855 return handleErrorImpl(std::move(Payload),
856 std::forward<HandlerTs>(Handlers)...);
857}
858
859/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
860/// unhandled errors (or Errors returned by handlers) are re-concatenated and
861/// returned.
862/// Because this function returns an error, its result must also be checked
863/// or returned. If you intend to handle all errors use handleAllErrors
864/// (which returns void, and will abort() on unhandled errors) instead.
865template <typename... HandlerTs>
866Error handleErrors(Error E, HandlerTs &&... Hs) {
867 if (!E)
868 return Error::success();
869
870 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
871
872 if (Payload->isA<ErrorList>()) {
873 ErrorList &List = static_cast<ErrorList &>(*Payload);
874 Error R;
875 for (auto &P : List.Payloads)
876 R = ErrorList::join(
877 std::move(R),
878 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
879 return R;
880 }
881
882 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
883}
884
885/// Behaves the same as handleErrors, except that it requires that all
886/// errors be handled by the given handlers. If any unhandled error remains
887/// after the handlers have run, report_fatal_error() will be called.
888template <typename... HandlerTs>
889void handleAllErrors(Error E, HandlerTs &&... Handlers) {
890 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
891}
892
893/// Check that E is a non-error, then drop it.
894/// If E is an error report_fatal_error will be called.
895inline void handleAllErrors(Error E) {
896 cantFail(std::move(E));
897}
898
899/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
900///
901/// If the incoming value is a success value it is returned unmodified. If it
902/// is a failure value then it the contained error is passed to handleErrors.
903/// If handleErrors is able to handle the error then the RecoveryPath functor
904/// is called to supply the final result. If handleErrors is not able to
905/// handle all errors then the unhandled errors are returned.
906///
907/// This utility enables the follow pattern:
908///
909/// @code{.cpp}
910/// enum FooStrategy { Aggressive, Conservative };
911/// Expected<Foo> foo(FooStrategy S);
912///
913/// auto ResultOrErr =
914/// handleExpected(
915/// foo(Aggressive),
916/// []() { return foo(Conservative); },
917/// [](AggressiveStrategyError&) {
918/// // Implicitly conusme this - we'll recover by using a conservative
919/// // strategy.
920/// });
921///
922/// @endcode
923template <typename T, typename RecoveryFtor, typename... HandlerTs>
924Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
925 HandlerTs &&... Handlers) {
926 if (ValOrErr)
927 return ValOrErr;
928
929 if (auto Err = handleErrors(ValOrErr.takeError(),
930 std::forward<HandlerTs>(Handlers)...))
931 return std::move(Err);
932
933 return RecoveryPath();
934}
935
936/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
937/// will be printed before the first one is logged. A newline will be printed
938/// after each error.
939///
940/// This is useful in the base level of your program to allow clean termination
941/// (allowing clean deallocation of resources, etc.), while reporting error
942/// information to the user.
943void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
944
945/// Write all error messages (if any) in E to a string. The newline character
946/// is used to separate error messages.
947inline std::string toString(Error E) {
948 SmallVector<std::string, 2> Errors;
949 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
950 Errors.push_back(EI.message());
951 });
952 return join(Errors.begin(), Errors.end(), "\n");
953}
954
955/// Consume a Error without doing anything. This method should be used
956/// only where an error can be considered a reasonable and expected return
957/// value.
958///
959/// Uses of this method are potentially indicative of design problems: If it's
960/// legitimate to do nothing while processing an "error", the error-producer
961/// might be more clearly refactored to return an Optional<T>.
962inline void consumeError(Error Err) {
963 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
964}
965
966/// Helper for Errors used as out-parameters.
967///
968/// This helper is for use with the Error-as-out-parameter idiom, where an error
969/// is passed to a function or method by reference, rather than being returned.
970/// In such cases it is helpful to set the checked bit on entry to the function
971/// so that the error can be written to (unchecked Errors abort on assignment)
972/// and clear the checked bit on exit so that clients cannot accidentally forget
973/// to check the result. This helper performs these actions automatically using
974/// RAII:
975///
976/// @code{.cpp}
977/// Result foo(Error &Err) {
978/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
979/// // <body of foo>
980/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
981/// }
982/// @endcode
983///
984/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
985/// used with optional Errors (Error pointers that are allowed to be null). If
986/// ErrorAsOutParameter took an Error reference, an instance would have to be
987/// created inside every condition that verified that Error was non-null. By
988/// taking an Error pointer we can just create one instance at the top of the
989/// function.
990class ErrorAsOutParameter {
991public:
992 ErrorAsOutParameter(Error *Err) : Err(Err) {
993 // Raise the checked bit if Err is success.
994 if (Err)
995 (void)!!*Err;
996 }
997
998 ~ErrorAsOutParameter() {
999 // Clear the checked bit.
1000 if (Err && !*Err)
1001 *Err = Error::success();
1002 }
1003
1004private:
1005 Error *Err;
1006};
1007
1008/// Helper for Expected<T>s used as out-parameters.
1009///
1010/// See ErrorAsOutParameter.
1011template <typename T>
1012class ExpectedAsOutParameter {
1013public:
1014 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1015 : ValOrErr(ValOrErr) {
1016 if (ValOrErr)
1017 (void)!!*ValOrErr;
1018 }
1019
1020 ~ExpectedAsOutParameter() {
1021 if (ValOrErr)
1022 ValOrErr->setUnchecked();
1023 }
1024
1025private:
1026 Expected<T> *ValOrErr;
1027};
1028
1029/// This class wraps a std::error_code in a Error.
1030///
1031/// This is useful if you're writing an interface that returns a Error
1032/// (or Expected) and you want to call code that still returns
1033/// std::error_codes.
1034class ECError : public ErrorInfo<ECError> {
1035 friend Error errorCodeToError(std::error_code);
1036
1037public:
1038 void setErrorCode(std::error_code EC) { this->EC = EC; }
1039 std::error_code convertToErrorCode() const override { return EC; }
1040 void log(raw_ostream &OS) const override { OS << EC.message(); }
1041
1042 // Used by ErrorInfo::classID.
1043 static char ID;
1044
1045protected:
1046 ECError() = default;
1047 ECError(std::error_code EC) : EC(EC) {}
1048
1049 std::error_code EC;
1050};
1051
1052/// The value returned by this function can be returned from convertToErrorCode
1053/// for Error values where no sensible translation to std::error_code exists.
1054/// It should only be used in this situation, and should never be used where a
1055/// sensible conversion to std::error_code is available, as attempts to convert
1056/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1057///error to try to convert such a value).
1058std::error_code inconvertibleErrorCode();
1059
1060/// Helper for converting an std::error_code to a Error.
1061Error errorCodeToError(std::error_code EC);
1062
1063/// Helper for converting an ECError to a std::error_code.
1064///
1065/// This method requires that Err be Error() or an ECError, otherwise it
1066/// will trigger a call to abort().
1067std::error_code errorToErrorCode(Error Err);
1068
1069/// Convert an ErrorOr<T> to an Expected<T>.
1070template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1071 if (auto EC = EO.getError())
1072 return errorCodeToError(EC);
1073 return std::move(*EO);
1074}
1075
1076/// Convert an Expected<T> to an ErrorOr<T>.
1077template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1078 if (auto Err = E.takeError())
1079 return errorToErrorCode(std::move(Err));
1080 return std::move(*E);
1081}
1082
1083/// This class wraps a string in an Error.
1084///
1085/// StringError is useful in cases where the client is not expected to be able
1086/// to consume the specific error message programmatically (for example, if the
1087/// error message is to be presented to the user).
1088class StringError : public ErrorInfo<StringError> {
1089public:
1090 static char ID;
1091
1092 StringError(const Twine &S, std::error_code EC);
1093
1094 void log(raw_ostream &OS) const override;
1095 std::error_code convertToErrorCode() const override;
1096
1097 const std::string &getMessage() const { return Msg; }
1098
1099private:
1100 std::string Msg;
1101 std::error_code EC;
1102};
1103
1104/// Helper for check-and-exit error handling.
1105///
1106/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1107///
1108class ExitOnError {
1109public:
1110 /// Create an error on exit helper.
1111 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1112 : Banner(std::move(Banner)),
1113 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1114
1115 /// Set the banner string for any errors caught by operator().
1116 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1117
1118 /// Set the exit-code mapper function.
1119 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1120 this->GetExitCode = std::move(GetExitCode);
1121 }
1122
1123 /// Check Err. If it's in a failure state log the error(s) and exit.
1124 void operator()(Error Err) const { checkError(std::move(Err)); }
1125
1126 /// Check E. If it's in a success state then return the contained value. If
1127 /// it's in a failure state log the error(s) and exit.
1128 template <typename T> T operator()(Expected<T> &&E) const {
1129 checkError(E.takeError());
1130 return std::move(*E);
1131 }
1132
1133 /// Check E. If it's in a success state then return the contained reference. If
1134 /// it's in a failure state log the error(s) and exit.
1135 template <typename T> T& operator()(Expected<T&> &&E) const {
1136 checkError(E.takeError());
1137 return *E;
1138 }
1139
1140private:
1141 void checkError(Error Err) const {
1142 if (Err) {
1143 int ExitCode = GetExitCode(Err);
1144 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1145 exit(ExitCode);
1146 }
1147 }
1148
1149 std::string Banner;
1150 std::function<int(const Error &)> GetExitCode;
1151};
1152
1153} // end namespace llvm
1154
1155#endif // LLVM_SUPPORT_ERROR_H