Bug Summary

File:include/llvm/Bitstream/BitstreamReader.h
Warning:line 220, column 39
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SerializedDiagnosticReader.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/tools/clang/lib/Frontend -I /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Frontend -I /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn374877/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/tools/clang/lib/Frontend -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn374877=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-10-15-233810-7101-1 -x c++ /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Frontend/SerializedDiagnosticReader.cpp

/build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Frontend/SerializedDiagnosticReader.cpp

1//===- SerializedDiagnosticReader.cpp - Reads diagnostics -----------------===//
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#include "clang/Frontend/SerializedDiagnosticReader.h"
10#include "clang/Basic/FileManager.h"
11#include "clang/Basic/FileSystemOptions.h"
12#include "clang/Frontend/SerializedDiagnostics.h"
13#include "llvm/ADT/Optional.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/ADT/StringRef.h"
16#include "llvm/Bitstream/BitCodes.h"
17#include "llvm/Bitstream/BitstreamReader.h"
18#include "llvm/Support/Compiler.h"
19#include "llvm/Support/ErrorHandling.h"
20#include "llvm/Support/ErrorOr.h"
21#include "llvm/Support/ManagedStatic.h"
22#include <cstdint>
23#include <system_error>
24
25using namespace clang;
26using namespace serialized_diags;
27
28std::error_code SerializedDiagnosticReader::readDiagnostics(StringRef File) {
29 // Open the diagnostics file.
30 FileSystemOptions FO;
31 FileManager FileMgr(FO);
32
33 auto Buffer = FileMgr.getBufferForFile(File);
34 if (!Buffer)
1
Taking false branch
35 return SDError::CouldNotLoad;
36
37 llvm::BitstreamCursor Stream(**Buffer);
38 Optional<llvm::BitstreamBlockInfo> BlockInfo;
39
40 if (Stream.AtEndOfStream())
2
Taking false branch
41 return SDError::InvalidSignature;
42
43 // Sniff for the signature.
44 for (unsigned char C : {'D', 'I', 'A', 'G'}) {
3
Assuming '__begin1' is not equal to '__end1'
45 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Stream.Read(8)) {
4
Calling 'SimpleBitstreamCursor::Read'
46 if (Res.get() == C)
47 continue;
48 } else {
49 // FIXME this drops the error on the floor.
50 consumeError(Res.takeError());
51 }
52 return SDError::InvalidSignature;
53 }
54
55 // Read the top level blocks.
56 while (!Stream.AtEndOfStream()) {
57 if (Expected<unsigned> Res = Stream.ReadCode()) {
58 if (Res.get() != llvm::bitc::ENTER_SUBBLOCK)
59 return SDError::InvalidDiagnostics;
60 } else {
61 // FIXME this drops the error on the floor.
62 consumeError(Res.takeError());
63 return SDError::InvalidDiagnostics;
64 }
65
66 std::error_code EC;
67 Expected<unsigned> MaybeSubBlockID = Stream.ReadSubBlockID();
68 if (!MaybeSubBlockID) {
69 // FIXME this drops the error on the floor.
70 consumeError(MaybeSubBlockID.takeError());
71 return SDError::InvalidDiagnostics;
72 }
73
74 switch (MaybeSubBlockID.get()) {
75 case llvm::bitc::BLOCKINFO_BLOCK_ID: {
76 Expected<Optional<llvm::BitstreamBlockInfo>> MaybeBlockInfo =
77 Stream.ReadBlockInfoBlock();
78 if (!MaybeBlockInfo) {
79 // FIXME this drops the error on the floor.
80 consumeError(MaybeBlockInfo.takeError());
81 return SDError::InvalidDiagnostics;
82 }
83 BlockInfo = std::move(MaybeBlockInfo.get());
84 }
85 if (!BlockInfo)
86 return SDError::MalformedBlockInfoBlock;
87 Stream.setBlockInfo(&*BlockInfo);
88 continue;
89 case BLOCK_META:
90 if ((EC = readMetaBlock(Stream)))
91 return EC;
92 continue;
93 case BLOCK_DIAG:
94 if ((EC = readDiagnosticBlock(Stream)))
95 return EC;
96 continue;
97 default:
98 if (llvm::Error Err = Stream.SkipBlock()) {
99 // FIXME this drops the error on the floor.
100 consumeError(std::move(Err));
101 return SDError::MalformedTopLevelBlock;
102 }
103 continue;
104 }
105 }
106 return {};
107}
108
109enum class SerializedDiagnosticReader::Cursor {
110 Record = 1,
111 BlockEnd,
112 BlockBegin
113};
114
115llvm::ErrorOr<SerializedDiagnosticReader::Cursor>
116SerializedDiagnosticReader::skipUntilRecordOrBlock(
117 llvm::BitstreamCursor &Stream, unsigned &BlockOrRecordID) {
118 BlockOrRecordID = 0;
119
120 while (!Stream.AtEndOfStream()) {
121 unsigned Code;
122 if (Expected<unsigned> Res = Stream.ReadCode())
123 Code = Res.get();
124 else
125 return llvm::errorToErrorCode(Res.takeError());
126
127 if (Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
128 // We found a record.
129 BlockOrRecordID = Code;
130 return Cursor::Record;
131 }
132 switch (static_cast<llvm::bitc::FixedAbbrevIDs>(Code)) {
133 case llvm::bitc::ENTER_SUBBLOCK:
134 if (Expected<unsigned> Res = Stream.ReadSubBlockID())
135 BlockOrRecordID = Res.get();
136 else
137 return llvm::errorToErrorCode(Res.takeError());
138 return Cursor::BlockBegin;
139
140 case llvm::bitc::END_BLOCK:
141 if (Stream.ReadBlockEnd())
142 return SDError::InvalidDiagnostics;
143 return Cursor::BlockEnd;
144
145 case llvm::bitc::DEFINE_ABBREV:
146 if (llvm::Error Err = Stream.ReadAbbrevRecord())
147 return llvm::errorToErrorCode(std::move(Err));
148 continue;
149
150 case llvm::bitc::UNABBREV_RECORD:
151 return SDError::UnsupportedConstruct;
152
153 case llvm::bitc::FIRST_APPLICATION_ABBREV:
154 llvm_unreachable("Unexpected abbrev id.")::llvm::llvm_unreachable_internal("Unexpected abbrev id.", "/build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Frontend/SerializedDiagnosticReader.cpp"
, 154)
;
155 }
156 }
157
158 return SDError::InvalidDiagnostics;
159}
160
161std::error_code
162SerializedDiagnosticReader::readMetaBlock(llvm::BitstreamCursor &Stream) {
163 if (llvm::Error Err =
164 Stream.EnterSubBlock(clang::serialized_diags::BLOCK_META)) {
165 // FIXME this drops the error on the floor.
166 consumeError(std::move(Err));
167 return SDError::MalformedMetadataBlock;
168 }
169
170 bool VersionChecked = false;
171
172 while (true) {
173 unsigned BlockOrCode = 0;
174 llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
175 if (!Res)
176 Res.getError();
177
178 switch (Res.get()) {
179 case Cursor::Record:
180 break;
181 case Cursor::BlockBegin:
182 if (llvm::Error Err = Stream.SkipBlock()) {
183 // FIXME this drops the error on the floor.
184 consumeError(std::move(Err));
185 return SDError::MalformedMetadataBlock;
186 }
187 LLVM_FALLTHROUGH[[gnu::fallthrough]];
188 case Cursor::BlockEnd:
189 if (!VersionChecked)
190 return SDError::MissingVersion;
191 return {};
192 }
193
194 SmallVector<uint64_t, 1> Record;
195 Expected<unsigned> MaybeRecordID = Stream.readRecord(BlockOrCode, Record);
196 if (!MaybeRecordID)
197 return errorToErrorCode(MaybeRecordID.takeError());
198 unsigned RecordID = MaybeRecordID.get();
199
200 if (RecordID == RECORD_VERSION) {
201 if (Record.size() < 1)
202 return SDError::MissingVersion;
203 if (Record[0] > VersionNumber)
204 return SDError::VersionMismatch;
205 VersionChecked = true;
206 }
207 }
208}
209
210std::error_code
211SerializedDiagnosticReader::readDiagnosticBlock(llvm::BitstreamCursor &Stream) {
212 if (llvm::Error Err =
213 Stream.EnterSubBlock(clang::serialized_diags::BLOCK_DIAG)) {
214 // FIXME this drops the error on the floor.
215 consumeError(std::move(Err));
216 return SDError::MalformedDiagnosticBlock;
217 }
218
219 std::error_code EC;
220 if ((EC = visitStartOfDiagnostic()))
221 return EC;
222
223 SmallVector<uint64_t, 16> Record;
224 while (true) {
225 unsigned BlockOrCode = 0;
226 llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
227 if (!Res)
228 Res.getError();
229
230 switch (Res.get()) {
231 case Cursor::BlockBegin:
232 // The only blocks we care about are subdiagnostics.
233 if (BlockOrCode == serialized_diags::BLOCK_DIAG) {
234 if ((EC = readDiagnosticBlock(Stream)))
235 return EC;
236 } else if (llvm::Error Err = Stream.SkipBlock()) {
237 // FIXME this drops the error on the floor.
238 consumeError(std::move(Err));
239 return SDError::MalformedSubBlock;
240 }
241 continue;
242 case Cursor::BlockEnd:
243 if ((EC = visitEndOfDiagnostic()))
244 return EC;
245 return {};
246 case Cursor::Record:
247 break;
248 }
249
250 // Read the record.
251 Record.clear();
252 StringRef Blob;
253 Expected<unsigned> MaybeRecID =
254 Stream.readRecord(BlockOrCode, Record, &Blob);
255 if (!MaybeRecID)
256 return errorToErrorCode(MaybeRecID.takeError());
257 unsigned RecID = MaybeRecID.get();
258
259 if (RecID < serialized_diags::RECORD_FIRST ||
260 RecID > serialized_diags::RECORD_LAST)
261 continue;
262
263 switch ((RecordIDs)RecID) {
264 case RECORD_CATEGORY:
265 // A category has ID and name size.
266 if (Record.size() != 2)
267 return SDError::MalformedDiagnosticRecord;
268 if ((EC = visitCategoryRecord(Record[0], Blob)))
269 return EC;
270 continue;
271 case RECORD_DIAG:
272 // A diagnostic has severity, location (4), category, flag, and message
273 // size.
274 if (Record.size() != 8)
275 return SDError::MalformedDiagnosticRecord;
276 if ((EC = visitDiagnosticRecord(
277 Record[0], Location(Record[1], Record[2], Record[3], Record[4]),
278 Record[5], Record[6], Blob)))
279 return EC;
280 continue;
281 case RECORD_DIAG_FLAG:
282 // A diagnostic flag has ID and name size.
283 if (Record.size() != 2)
284 return SDError::MalformedDiagnosticRecord;
285 if ((EC = visitDiagFlagRecord(Record[0], Blob)))
286 return EC;
287 continue;
288 case RECORD_FILENAME:
289 // A filename has ID, size, timestamp, and name size. The size and
290 // timestamp are legacy fields that are always zero these days.
291 if (Record.size() != 4)
292 return SDError::MalformedDiagnosticRecord;
293 if ((EC = visitFilenameRecord(Record[0], Record[1], Record[2], Blob)))
294 return EC;
295 continue;
296 case RECORD_FIXIT:
297 // A fixit has two locations (4 each) and message size.
298 if (Record.size() != 9)
299 return SDError::MalformedDiagnosticRecord;
300 if ((EC = visitFixitRecord(
301 Location(Record[0], Record[1], Record[2], Record[3]),
302 Location(Record[4], Record[5], Record[6], Record[7]), Blob)))
303 return EC;
304 continue;
305 case RECORD_SOURCE_RANGE:
306 // A source range is two locations (4 each).
307 if (Record.size() != 8)
308 return SDError::MalformedDiagnosticRecord;
309 if ((EC = visitSourceRangeRecord(
310 Location(Record[0], Record[1], Record[2], Record[3]),
311 Location(Record[4], Record[5], Record[6], Record[7]))))
312 return EC;
313 continue;
314 case RECORD_VERSION:
315 // A version is just a number.
316 if (Record.size() != 1)
317 return SDError::MalformedDiagnosticRecord;
318 if ((EC = visitVersionRecord(Record[0])))
319 return EC;
320 continue;
321 }
322 }
323}
324
325namespace {
326
327class SDErrorCategoryType final : public std::error_category {
328 const char *name() const noexcept override {
329 return "clang.serialized_diags";
330 }
331
332 std::string message(int IE) const override {
333 auto E = static_cast<SDError>(IE);
334 switch (E) {
335 case SDError::CouldNotLoad:
336 return "Failed to open diagnostics file";
337 case SDError::InvalidSignature:
338 return "Invalid diagnostics signature";
339 case SDError::InvalidDiagnostics:
340 return "Parse error reading diagnostics";
341 case SDError::MalformedTopLevelBlock:
342 return "Malformed block at top-level of diagnostics";
343 case SDError::MalformedSubBlock:
344 return "Malformed sub-block in a diagnostic";
345 case SDError::MalformedBlockInfoBlock:
346 return "Malformed BlockInfo block";
347 case SDError::MalformedMetadataBlock:
348 return "Malformed Metadata block";
349 case SDError::MalformedDiagnosticBlock:
350 return "Malformed Diagnostic block";
351 case SDError::MalformedDiagnosticRecord:
352 return "Malformed Diagnostic record";
353 case SDError::MissingVersion:
354 return "No version provided in diagnostics";
355 case SDError::VersionMismatch:
356 return "Unsupported diagnostics version";
357 case SDError::UnsupportedConstruct:
358 return "Bitcode constructs that are not supported in diagnostics appear";
359 case SDError::HandlerFailed:
360 return "Generic error occurred while handling a record";
361 }
362 llvm_unreachable("Unknown error type!")::llvm::llvm_unreachable_internal("Unknown error type!", "/build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Frontend/SerializedDiagnosticReader.cpp"
, 362)
;
363 }
364};
365
366} // namespace
367
368static llvm::ManagedStatic<SDErrorCategoryType> ErrorCategory;
369const std::error_category &clang::serialized_diags::SDErrorCategory() {
370 return *ErrorCategory;
371}

/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h

1//===- BitstreamReader.h - Low-level bitstream reader interface -*- 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// This header defines the BitstreamReader class. This class can be used to
10// read an arbitrary bitstream, regardless of its contents.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H
15#define LLVM_BITSTREAM_BITSTREAMREADER_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Bitstream/BitCodes.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/MathExtras.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include <algorithm>
25#include <cassert>
26#include <climits>
27#include <cstddef>
28#include <cstdint>
29#include <memory>
30#include <string>
31#include <utility>
32#include <vector>
33
34namespace llvm {
35
36/// This class maintains the abbreviations read from a block info block.
37class BitstreamBlockInfo {
38public:
39 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
40 /// describe abbreviations that all blocks of the specified ID inherit.
41 struct BlockInfo {
42 unsigned BlockID;
43 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
44 std::string Name;
45 std::vector<std::pair<unsigned, std::string>> RecordNames;
46 };
47
48private:
49 std::vector<BlockInfo> BlockInfoRecords;
50
51public:
52 /// If there is block info for the specified ID, return it, otherwise return
53 /// null.
54 const BlockInfo *getBlockInfo(unsigned BlockID) const {
55 // Common case, the most recent entry matches BlockID.
56 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
57 return &BlockInfoRecords.back();
58
59 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
60 i != e; ++i)
61 if (BlockInfoRecords[i].BlockID == BlockID)
62 return &BlockInfoRecords[i];
63 return nullptr;
64 }
65
66 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
67 if (const BlockInfo *BI = getBlockInfo(BlockID))
68 return *const_cast<BlockInfo*>(BI);
69
70 // Otherwise, add a new record.
71 BlockInfoRecords.emplace_back();
72 BlockInfoRecords.back().BlockID = BlockID;
73 return BlockInfoRecords.back();
74 }
75};
76
77/// This represents a position within a bitstream. There may be multiple
78/// independent cursors reading within one bitstream, each maintaining their
79/// own local state.
80class SimpleBitstreamCursor {
81 ArrayRef<uint8_t> BitcodeBytes;
82 size_t NextChar = 0;
83
84public:
85 /// This is the current data we have pulled from the stream but have not
86 /// returned to the client. This is specifically and intentionally defined to
87 /// follow the word size of the host machine for efficiency. We use word_t in
88 /// places that are aware of this to make it perfectly explicit what is going
89 /// on.
90 using word_t = size_t;
91
92private:
93 word_t CurWord = 0;
94
95 /// This is the number of bits in CurWord that are valid. This is always from
96 /// [0...bits_of(size_t)-1] inclusive.
97 unsigned BitsInCurWord = 0;
98
99public:
100 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
101
102 SimpleBitstreamCursor() = default;
103 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
104 : BitcodeBytes(BitcodeBytes) {}
105 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
106 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
107 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
108 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
109
110 bool canSkipToPos(size_t pos) const {
111 // pos can be skipped to if it is a valid address or one byte past the end.
112 return pos <= BitcodeBytes.size();
113 }
114
115 bool AtEndOfStream() {
116 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
117 }
118
119 /// Return the bit # of the bit we are reading.
120 uint64_t GetCurrentBitNo() const {
121 return NextChar*CHAR_BIT8 - BitsInCurWord;
122 }
123
124 // Return the byte # of the current bit.
125 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
126
127 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
128
129 /// Reset the stream to the specified bit number.
130 Error JumpToBit(uint64_t BitNo) {
131 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
132 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
133 assert(canSkipToPos(ByteNo) && "Invalid location")((canSkipToPos(ByteNo) && "Invalid location") ? static_cast
<void> (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 133, __PRETTY_FUNCTION__))
;
134
135 // Move the cursor to the right word.
136 NextChar = ByteNo;
137 BitsInCurWord = 0;
138
139 // Skip over any bits that are already consumed.
140 if (WordBitNo) {
141 if (Expected<word_t> Res = Read(WordBitNo))
142 return Error::success();
143 else
144 return Res.takeError();
145 }
146
147 return Error::success();
148 }
149
150 /// Get a pointer into the bitstream at the specified byte offset.
151 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
152 return BitcodeBytes.data() + ByteNo;
153 }
154
155 /// Get a pointer into the bitstream at the specified bit offset.
156 ///
157 /// The bit offset must be on a byte boundary.
158 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
159 assert(!(BitNo % 8) && "Expected bit on byte boundary")((!(BitNo % 8) && "Expected bit on byte boundary") ? static_cast
<void> (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 159, __PRETTY_FUNCTION__))
;
160 return getPointerToByte(BitNo / 8, NumBytes);
161 }
162
163 Error fillCurWord() {
164 if (NextChar >= BitcodeBytes.size())
165 return createStringError(std::errc::io_error,
166 "Unexpected end of file reading %u of %u bytes",
167 NextChar, BitcodeBytes.size());
168
169 // Read the next word from the stream.
170 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
171 unsigned BytesRead;
172 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
173 BytesRead = sizeof(word_t);
174 CurWord =
175 support::endian::read<word_t, support::little, support::unaligned>(
176 NextCharPtr);
177 } else {
178 // Short read.
179 BytesRead = BitcodeBytes.size() - NextChar;
180 CurWord = 0;
181 for (unsigned B = 0; B != BytesRead; ++B)
182 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
183 }
184 NextChar += BytesRead;
185 BitsInCurWord = BytesRead * 8;
186 return Error::success();
187 }
188
189 Expected<word_t> Read(unsigned NumBits) {
190 static const unsigned BitsInWord = MaxChunkSize;
191
192 assert
4.1
'NumBits' is 8
4.2
'NumBits' is <= 'BitsInWord'
4.1
'NumBits' is 8
4.2
'NumBits' is <= 'BitsInWord'
4.1
'NumBits' is 8
4.2
'NumBits' is <= 'BitsInWord'(NumBits && NumBits <= BitsInWord &&((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
5
'?' condition is true
193 "Cannot return zero or more than BitsInWord bits!")((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
; 194 195 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
6
'?' condition is true
196 197 // If the field is fully contained by CurWord, return it quickly. 198 if (BitsInCurWord >= NumBits) {
7
Assuming 'NumBits' is > field 'BitsInCurWord'
8
Taking false branch
199 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits)); 200 201 // Use a mask to avoid undefined behavior. 202 CurWord >>= (NumBits & Mask); 203 204 BitsInCurWord -= NumBits; 205 return R; 206 } 207 208 word_t R = BitsInCurWord
8.1
Field 'BitsInCurWord' is not equal to 0
8.1
Field 'BitsInCurWord' is not equal to 0
8.1
Field 'BitsInCurWord' is not equal to 0
? CurWord : 0;
9
'?' condition is true
209 unsigned BitsLeft = NumBits - BitsInCurWord; 210 211 if (Error fillResult = fillCurWord())
10
Calling 'Error::operator bool'
12
Returning from 'Error::operator bool'
13
Taking false branch
212 return std::move(fillResult); 213 214 // If we run out of data, abort. 215 if (BitsLeft > BitsInCurWord)
14
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
15
Taking false branch
216 return createStringError(std::errc::io_error, 217 "Unexpected end of file reading %u of %u bits", 218 BitsInCurWord, BitsLeft); 219 220 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
16
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
221 222 // Use a mask to avoid undefined behavior. 223 CurWord >>= (BitsLeft & Mask); 224 225 BitsInCurWord -= BitsLeft; 226 227 R |= R2 << (NumBits - BitsLeft); 228 229 return R; 230 } 231 232 Expected<uint32_t> ReadVBR(unsigned NumBits) { 233 Expected<unsigned> MaybeRead = Read(NumBits); 234 if (!MaybeRead) 235 return MaybeRead; 236 uint32_t Piece = MaybeRead.get(); 237 238 if ((Piece & (1U << (NumBits-1))) == 0) 239 return Piece; 240 241 uint32_t Result = 0; 242 unsigned NextBit = 0; 243 while (true) { 244 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit; 245 246 if ((Piece & (1U << (NumBits-1))) == 0) 247 return Result; 248 249 NextBit += NumBits-1; 250 MaybeRead = Read(NumBits); 251 if (!MaybeRead) 252 return MaybeRead; 253 Piece = MaybeRead.get(); 254 } 255 } 256 257 // Read a VBR that may have a value up to 64-bits in size. The chunk size of 258 // the VBR must still be <= 32 bits though. 259 Expected<uint64_t> ReadVBR64(unsigned NumBits) { 260 Expected<uint64_t> MaybeRead = Read(NumBits); 261 if (!MaybeRead) 262 return MaybeRead; 263 uint32_t Piece = MaybeRead.get(); 264 265 if ((Piece & (1U << (NumBits-1))) == 0) 266 return uint64_t(Piece); 267 268 uint64_t Result = 0; 269 unsigned NextBit = 0; 270 while (true) { 271 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit; 272 273 if ((Piece & (1U << (NumBits-1))) == 0) 274 return Result; 275 276 NextBit += NumBits-1; 277 MaybeRead = Read(NumBits); 278 if (!MaybeRead) 279 return MaybeRead; 280 Piece = MaybeRead.get(); 281 } 282 } 283 284 void SkipToFourByteBoundary() { 285 // If word_t is 64-bits and if we've read less than 32 bits, just dump 286 // the bits we have up to the next 32-bit boundary. 287 if (sizeof(word_t) > 4 && 288 BitsInCurWord >= 32) { 289 CurWord >>= BitsInCurWord-32; 290 BitsInCurWord = 32; 291 return; 292 } 293 294 BitsInCurWord = 0; 295 } 296 297 /// Return the size of the stream in bytes. 298 size_t SizeInBytes() const { return BitcodeBytes.size(); } 299 300 /// Skip to the end of the file. 301 void skipToEnd() { NextChar = BitcodeBytes.size(); } 302}; 303 304/// When advancing through a bitstream cursor, each advance can discover a few 305/// different kinds of entries: 306struct BitstreamEntry { 307 enum { 308 Error, // Malformed bitcode was found. 309 EndBlock, // We've reached the end of the current block, (or the end of the 310 // file, which is treated like a series of EndBlock records. 311 SubBlock, // This is the start of a new subblock of a specific ID. 312 Record // This is a record with a specific AbbrevID. 313 } Kind; 314 315 unsigned ID; 316 317 static BitstreamEntry getError() { 318 BitstreamEntry E; E.Kind = Error; return E; 319 } 320 321 static BitstreamEntry getEndBlock() { 322 BitstreamEntry E; E.Kind = EndBlock; return E; 323 } 324 325 static BitstreamEntry getSubBlock(unsigned ID) { 326 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E; 327 } 328 329 static BitstreamEntry getRecord(unsigned AbbrevID) { 330 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E; 331 } 332}; 333 334/// This represents a position within a bitcode file, implemented on top of a 335/// SimpleBitstreamCursor. 336/// 337/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not 338/// be passed by value. 339class BitstreamCursor : SimpleBitstreamCursor { 340 // This is the declared size of code values used for the current block, in 341 // bits. 342 unsigned CurCodeSize = 2; 343 344 /// Abbrevs installed at in this block. 345 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs; 346 347 struct Block { 348 unsigned PrevCodeSize; 349 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs; 350 351 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {} 352 }; 353 354 /// This tracks the codesize of parent blocks. 355 SmallVector<Block, 8> BlockScope; 356 357 BitstreamBlockInfo *BlockInfo = nullptr; 358 359public: 360 static const size_t MaxChunkSize = sizeof(word_t) * 8; 361 362 BitstreamCursor() = default; 363 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes) 364 : SimpleBitstreamCursor(BitcodeBytes) {} 365 explicit BitstreamCursor(StringRef BitcodeBytes) 366 : SimpleBitstreamCursor(BitcodeBytes) {} 367 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes) 368 : SimpleBitstreamCursor(BitcodeBytes) {} 369 370 using SimpleBitstreamCursor::AtEndOfStream; 371 using SimpleBitstreamCursor::canSkipToPos; 372 using SimpleBitstreamCursor::fillCurWord; 373 using SimpleBitstreamCursor::getBitcodeBytes; 374 using SimpleBitstreamCursor::GetCurrentBitNo; 375 using SimpleBitstreamCursor::getCurrentByteNo; 376 using SimpleBitstreamCursor::getPointerToByte; 377 using SimpleBitstreamCursor::JumpToBit; 378 using SimpleBitstreamCursor::Read; 379 using SimpleBitstreamCursor::ReadVBR; 380 using SimpleBitstreamCursor::ReadVBR64; 381 using SimpleBitstreamCursor::SizeInBytes; 382 using SimpleBitstreamCursor::skipToEnd; 383 384 /// Return the number of bits used to encode an abbrev #. 385 unsigned getAbbrevIDWidth() const { return CurCodeSize; } 386 387 /// Flags that modify the behavior of advance(). 388 enum { 389 /// If this flag is used, the advance() method does not automatically pop 390 /// the block scope when the end of a block is reached. 391 AF_DontPopBlockAtEnd = 1, 392 393 /// If this flag is used, abbrev entries are returned just like normal 394 /// records. 395 AF_DontAutoprocessAbbrevs = 2 396 }; 397 398 /// Advance the current bitstream, returning the next entry in the stream. 399 Expected<BitstreamEntry> advance(unsigned Flags = 0) { 400 while (true) { 401 if (AtEndOfStream()) 402 return BitstreamEntry::getError(); 403 404 Expected<unsigned> MaybeCode = ReadCode(); 405 if (!MaybeCode) 406 return MaybeCode.takeError(); 407 unsigned Code = MaybeCode.get(); 408 409 if (Code == bitc::END_BLOCK) { 410 // Pop the end of the block unless Flags tells us not to. 411 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd()) 412 return BitstreamEntry::getError(); 413 return BitstreamEntry::getEndBlock(); 414 } 415 416 if (Code == bitc::ENTER_SUBBLOCK) { 417 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID()) 418 return BitstreamEntry::getSubBlock(MaybeSubBlock.get()); 419 else 420 return MaybeSubBlock.takeError(); 421 } 422 423 if (Code == bitc::DEFINE_ABBREV && 424 !(Flags & AF_DontAutoprocessAbbrevs)) { 425 // We read and accumulate abbrev's, the client can't do anything with 426 // them anyway. 427 if (Error Err = ReadAbbrevRecord()) 428 return std::move(Err); 429 continue; 430 } 431 432 return BitstreamEntry::getRecord(Code); 433 } 434 } 435 436 /// This is a convenience function for clients that don't expect any 437 /// subblocks. This just skips over them automatically. 438 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) { 439 while (true) { 440 // If we found a normal entry, return it. 441 Expected<BitstreamEntry> MaybeEntry = advance(Flags); 442 if (!MaybeEntry) 443 return MaybeEntry; 444 BitstreamEntry Entry = MaybeEntry.get(); 445 446 if (Entry.Kind != BitstreamEntry::SubBlock) 447 return Entry; 448 449 // If we found a sub-block, just skip over it and check the next entry. 450 if (Error Err = SkipBlock()) 451 return std::move(Err); 452 } 453 } 454 455 Expected<unsigned> ReadCode() { return Read(CurCodeSize); } 456 457 // Block header: 458 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen] 459 460 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block. 461 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); } 462 463 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body 464 /// of this block. 465 Error SkipBlock() { 466 // Read and ignore the codelen value. 467 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth)) 468 ; // Since we are skipping this block, we don't care what code widths are 469 // used inside of it. 470 else 471 return Res.takeError(); 472 473 SkipToFourByteBoundary(); 474 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth); 475 if (!MaybeNum) 476 return MaybeNum.takeError(); 477 size_t NumFourBytes = MaybeNum.get(); 478 479 // Check that the block wasn't partially defined, and that the offset isn't 480 // bogus. 481 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8; 482 if (AtEndOfStream()) 483 return createStringError(std::errc::illegal_byte_sequence, 484 "can't skip block: already at end of stream"); 485 if (!canSkipToPos(SkipTo / 8)) 486 return createStringError(std::errc::illegal_byte_sequence, 487 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo, 488 GetCurrentBitNo()); 489 490 if (Error Res = JumpToBit(SkipTo)) 491 return Res; 492 493 return Error::success(); 494 } 495 496 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block. 497 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr); 498 499 bool ReadBlockEnd() { 500 if (BlockScope.empty()) return true; 501 502 // Block tail: 503 // [END_BLOCK, <align4bytes>] 504 SkipToFourByteBoundary(); 505 506 popBlockScope(); 507 return false; 508 } 509 510private: 511 void popBlockScope() { 512 CurCodeSize = BlockScope.back().PrevCodeSize; 513 514 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs); 515 BlockScope.pop_back(); 516 } 517 518 //===--------------------------------------------------------------------===// 519 // Record Processing 520 //===--------------------------------------------------------------------===// 521 522public: 523 /// Return the abbreviation for the specified AbbrevId. 524 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) { 525 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV; 526 if (AbbrevNo >= CurAbbrevs.size()) 527 report_fatal_error("Invalid abbrev number"); 528 return CurAbbrevs[AbbrevNo].get(); 529 } 530 531 /// Read the current record and discard it, returning the code for the record. 532 Expected<unsigned> skipRecord(unsigned AbbrevID); 533 534 Expected<unsigned> readRecord(unsigned AbbrevID, 535 SmallVectorImpl<uint64_t> &Vals, 536 StringRef *Blob = nullptr); 537 538 //===--------------------------------------------------------------------===// 539 // Abbrev Processing 540 //===--------------------------------------------------------------------===// 541 Error ReadAbbrevRecord(); 542 543 /// Read and return a block info block from the bitstream. If an error was 544 /// encountered, return None. 545 /// 546 /// \param ReadBlockInfoNames Whether to read block/record name information in 547 /// the BlockInfo block. Only llvm-bcanalyzer uses this. 548 Expected<Optional<BitstreamBlockInfo>> 549 ReadBlockInfoBlock(bool ReadBlockInfoNames = false); 550 551 /// Set the block info to be used by this BitstreamCursor to interpret 552 /// abbreviated records. 553 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; } 554}; 555 556} // end llvm namespace 557 558#endif // LLVM_BITSTREAM_BITSTREAMREADER_H

/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- 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// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.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/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
159 // pointers out of this class to add to the error list.
160 friend class ErrorList;
161 friend class FileError;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
11
Returning zero, which participates in a condition later
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
266 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275 }
276
277 void setPtr(ErrorInfoBase *EI) {
278#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
279 Payload = reinterpret_cast<ErrorInfoBase*>(
280 (reinterpret_cast<uintptr_t>(EI) &
281 ~static_cast<uintptr_t>(0x1)) |
282 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
283#else
284 Payload = EI;
285#endif
286 }
287
288 bool getChecked() const {
289#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
290 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
291#else
292 return true;
293#endif
294 }
295
296 void setChecked(bool V) {
297 Payload = reinterpret_cast<ErrorInfoBase*>(
298 (reinterpret_cast<uintptr_t>(Payload) &
299 ~static_cast<uintptr_t>(0x1)) |
300 (V ? 0 : 1));
301 }
302
303 std::unique_ptr<ErrorInfoBase> takePayload() {
304 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
305 setPtr(nullptr);
306 setChecked(true);
307 return Tmp;
308 }
309
310 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
311 if (auto P = E.getPtr())
312 P->log(OS);
313 else
314 OS << "success";
315 return OS;
316 }
317
318 ErrorInfoBase *Payload = nullptr;
319};
320
321/// Subclass of Error for the sole purpose of identifying the success path in
322/// the type system. This allows to catch invalid conversion to Expected<T> at
323/// compile time.
324class ErrorSuccess final : public Error {};
325
326inline ErrorSuccess Error::success() { return ErrorSuccess(); }
327
328/// Make a Error instance representing failure using the given error info
329/// type.
330template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
331 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
332}
333
334/// Base class for user error types. Users should declare their error types
335/// like:
336///
337/// class MyError : public ErrorInfo<MyError> {
338/// ....
339/// };
340///
341/// This class provides an implementation of the ErrorInfoBase::kind
342/// method, which is used by the Error RTTI system.
343template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
344class ErrorInfo : public ParentErrT {
345public:
346 using ParentErrT::ParentErrT; // inherit constructors
347
348 static const void *classID() { return &ThisErrT::ID; }
349
350 const void *dynamicClassID() const override { return &ThisErrT::ID; }
351
352 bool isA(const void *const ClassID) const override {
353 return ClassID == classID() || ParentErrT::isA(ClassID);
354 }
355};
356
357/// Special ErrorInfo subclass representing a list of ErrorInfos.
358/// Instances of this class are constructed by joinError.
359class ErrorList final : public ErrorInfo<ErrorList> {
360 // handleErrors needs to be able to iterate the payload list of an
361 // ErrorList.
362 template <typename... HandlerTs>
363 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
364
365 // joinErrors is implemented in terms of join.
366 friend Error joinErrors(Error, Error);
367
368public:
369 void log(raw_ostream &OS) const override {
370 OS << "Multiple errors:\n";
371 for (auto &ErrPayload : Payloads) {
372 ErrPayload->log(OS);
373 OS << "\n";
374 }
375 }
376
377 std::error_code convertToErrorCode() const override;
378
379 // Used by ErrorInfo::classID.
380 static char ID;
381
382private:
383 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
384 std::unique_ptr<ErrorInfoBase> Payload2) {
385 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
386 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
;
387 Payloads.push_back(std::move(Payload1));
388 Payloads.push_back(std::move(Payload2));
389 }
390
391 static Error join(Error E1, Error E2) {
392 if (!E1)
393 return E2;
394 if (!E2)
395 return E1;
396 if (E1.isA<ErrorList>()) {
397 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
398 if (E2.isA<ErrorList>()) {
399 auto E2Payload = E2.takePayload();
400 auto &E2List = static_cast<ErrorList &>(*E2Payload);
401 for (auto &Payload : E2List.Payloads)
402 E1List.Payloads.push_back(std::move(Payload));
403 } else
404 E1List.Payloads.push_back(E2.takePayload());
405
406 return E1;
407 }
408 if (E2.isA<ErrorList>()) {
409 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
410 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
411 return E2;
412 }
413 return Error(std::unique_ptr<ErrorList>(
414 new ErrorList(E1.takePayload(), E2.takePayload())));
415 }
416
417 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
418};
419
420/// Concatenate errors. The resulting Error is unchecked, and contains the
421/// ErrorInfo(s), if any, contained in E1, followed by the
422/// ErrorInfo(s), if any, contained in E2.
423inline Error joinErrors(Error E1, Error E2) {
424 return ErrorList::join(std::move(E1), std::move(E2));
425}
426
427/// Tagged union holding either a T or a Error.
428///
429/// This class parallels ErrorOr, but replaces error_code with Error. Since
430/// Error cannot be copied, this class replaces getError() with
431/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
432/// error class type.
433template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
434 template <class T1> friend class ExpectedAsOutParameter;
435 template <class OtherT> friend class Expected;
436
437 static const bool isRef = std::is_reference<T>::value;
438
439 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
440
441 using error_type = std::unique_ptr<ErrorInfoBase>;
442
443public:
444 using storage_type = typename std::conditional<isRef, wrap, T>::type;
445 using value_type = T;
446
447private:
448 using reference = typename std::remove_reference<T>::type &;
449 using const_reference = const typename std::remove_reference<T>::type &;
450 using pointer = typename std::remove_reference<T>::type *;
451 using const_pointer = const typename std::remove_reference<T>::type *;
452
453public:
454 /// Create an Expected<T> error value from the given Error.
455 Expected(Error Err)
456 : HasError(true)
457#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
458 // Expected is unchecked upon construction in Debug builds.
459 , Unchecked(true)
460#endif
461 {
462 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 462, __PRETTY_FUNCTION__))
;
463 new (getErrorStorage()) error_type(Err.takePayload());
464 }
465
466 /// Forbid to convert from Error::success() implicitly, this avoids having
467 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
468 /// but triggers the assertion above.
469 Expected(ErrorSuccess) = delete;
470
471 /// Create an Expected<T> success value from the given OtherT value, which
472 /// must be convertible to T.
473 template <typename OtherT>
474 Expected(OtherT &&Val,
475 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
476 * = nullptr)
477 : HasError(false)
478#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
479 // Expected is unchecked upon construction in Debug builds.
480 , Unchecked(true)
481#endif
482 {
483 new (getStorage()) storage_type(std::forward<OtherT>(Val));
484 }
485
486 /// Move construct an Expected<T> value.
487 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
488
489 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
490 /// must be convertible to T.
491 template <class OtherT>
492 Expected(Expected<OtherT> &&Other,
493 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
494 * = nullptr) {
495 moveConstruct(std::move(Other));
496 }
497
498 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
499 /// isn't convertible to T.
500 template <class OtherT>
501 explicit Expected(
502 Expected<OtherT> &&Other,
503 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
504 nullptr) {
505 moveConstruct(std::move(Other));
506 }
507
508 /// Move-assign from another Expected<T>.
509 Expected &operator=(Expected &&Other) {
510 moveAssign(std::move(Other));
511 return *this;
512 }
513
514 /// Destroy an Expected<T>.
515 ~Expected() {
516 assertIsChecked();
517 if (!HasError)
518 getStorage()->~storage_type();
519 else
520 getErrorStorage()->~error_type();
521 }
522
523 /// Return false if there is an error.
524 explicit operator bool() {
525#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
526 Unchecked = HasError;
527#endif
528 return !HasError;
529 }
530
531 /// Returns a reference to the stored T value.
532 reference get() {
533 assertIsChecked();
534 return *getStorage();
535 }
536
537 /// Returns a const reference to the stored T value.
538 const_reference get() const {
539 assertIsChecked();
540 return const_cast<Expected<T> *>(this)->get();
541 }
542
543 /// Check that this Expected<T> is an error of type ErrT.
544 template <typename ErrT> bool errorIsA() const {
545 return HasError && (*getErrorStorage())->template isA<ErrT>();
546 }
547
548 /// Take ownership of the stored error.
549 /// After calling this the Expected<T> is in an indeterminate state that can
550 /// only be safely destructed. No further calls (beside the destructor) should
551 /// be made on the Expected<T> value.
552 Error takeError() {
553#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
554 Unchecked = false;
555#endif
556 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
557 }
558
559 /// Returns a pointer to the stored T value.
560 pointer operator->() {
561 assertIsChecked();
562 return toPointer(getStorage());
563 }
564
565 /// Returns a const pointer to the stored T value.
566 const_pointer operator->() const {
567 assertIsChecked();
568 return toPointer(getStorage());
569 }
570
571 /// Returns a reference to the stored T value.
572 reference operator*() {
573 assertIsChecked();
574 return *getStorage();
575 }
576
577 /// Returns a const reference to the stored T value.
578 const_reference operator*() const {
579 assertIsChecked();
580 return *getStorage();
581 }
582
583private:
584 template <class T1>
585 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
586 return &a == &b;
587 }
588
589 template <class T1, class T2>
590 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
591 return false;
592 }
593
594 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
595 HasError = Other.HasError;
596#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
597 Unchecked = true;
598 Other.Unchecked = false;
599#endif
600
601 if (!HasError)
602 new (getStorage()) storage_type(std::move(*Other.getStorage()));
603 else
604 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
605 }
606
607 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
608 assertIsChecked();
609
610 if (compareThisIfSameType(*this, Other))
611 return;
612
613 this->~Expected();
614 new (this) Expected(std::move(Other));
615 }
616
617 pointer toPointer(pointer Val) { return Val; }
618
619 const_pointer toPointer(const_pointer Val) const { return Val; }
620
621 pointer toPointer(wrap *Val) { return &Val->get(); }
622
623 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
624
625 storage_type *getStorage() {
626 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 626, __PRETTY_FUNCTION__))
;
627 return reinterpret_cast<storage_type *>(TStorage.buffer);
628 }
629
630 const storage_type *getStorage() const {
631 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 631, __PRETTY_FUNCTION__))
;
632 return reinterpret_cast<const storage_type *>(TStorage.buffer);
633 }
634
635 error_type *getErrorStorage() {
636 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 636, __PRETTY_FUNCTION__))
;
637 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
638 }
639
640 const error_type *getErrorStorage() const {
641 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 641, __PRETTY_FUNCTION__))
;
642 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
643 }
644
645 // Used by ExpectedAsOutParameter to reset the checked flag.
646 void setUnchecked() {
647#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
648 Unchecked = true;
649#endif
650 }
651
652#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
653 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
654 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
655 void fatalUncheckedExpected() const {
656 dbgs() << "Expected<T> must be checked before access or destruction.\n";
657 if (HasError) {
658 dbgs() << "Unchecked Expected<T> contained error:\n";
659 (*getErrorStorage())->log(dbgs());
660 } else
661 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
662 "values in success mode must still be checked prior to being "
663 "destroyed).\n";
664 abort();
665 }
666#endif
667
668 void assertIsChecked() {
669#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
670 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
671 fatalUncheckedExpected();
672#endif
673 }
674
675 union {
676 AlignedCharArrayUnion<storage_type> TStorage;
677 AlignedCharArrayUnion<error_type> ErrorStorage;
678 };
679 bool HasError : 1;
680#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
681 bool Unchecked : 1;
682#endif
683};
684
685/// Report a serious error, calling any installed error handler. See
686/// ErrorHandling.h.
687LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
688 bool gen_crash_diag = true);
689
690/// Report a fatal error if Err is a failure value.
691///
692/// This function can be used to wrap calls to fallible functions ONLY when it
693/// is known that the Error will always be a success value. E.g.
694///
695/// @code{.cpp}
696/// // foo only attempts the fallible operation if DoFallibleOperation is
697/// // true. If DoFallibleOperation is false then foo always returns
698/// // Error::success().
699/// Error foo(bool DoFallibleOperation);
700///
701/// cantFail(foo(false));
702/// @endcode
703inline void cantFail(Error Err, const char *Msg = nullptr) {
704 if (Err) {
705 if (!Msg)
706 Msg = "Failure value returned from cantFail wrapped call";
707 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 707)
;
708 }
709}
710
711/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
712/// returns the contained value.
713///
714/// This function can be used to wrap calls to fallible functions ONLY when it
715/// is known that the Error will always be a success value. E.g.
716///
717/// @code{.cpp}
718/// // foo only attempts the fallible operation if DoFallibleOperation is
719/// // true. If DoFallibleOperation is false then foo always returns an int.
720/// Expected<int> foo(bool DoFallibleOperation);
721///
722/// int X = cantFail(foo(false));
723/// @endcode
724template <typename T>
725T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
726 if (ValOrErr)
727 return std::move(*ValOrErr);
728 else {
729 if (!Msg)
730 Msg = "Failure value returned from cantFail wrapped call";
731 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 731)
;
732 }
733}
734
735/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
736/// returns the contained reference.
737///
738/// This function can be used to wrap calls to fallible functions ONLY when it
739/// is known that the Error will always be a success value. E.g.
740///
741/// @code{.cpp}
742/// // foo only attempts the fallible operation if DoFallibleOperation is
743/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
744/// Expected<Bar&> foo(bool DoFallibleOperation);
745///
746/// Bar &X = cantFail(foo(false));
747/// @endcode
748template <typename T>
749T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
750 if (ValOrErr)
751 return *ValOrErr;
752 else {
753 if (!Msg)
754 Msg = "Failure value returned from cantFail wrapped call";
755 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 755)
;
756 }
757}
758
759/// Helper for testing applicability of, and applying, handlers for
760/// ErrorInfo types.
761template <typename HandlerT>
762class ErrorHandlerTraits
763 : public ErrorHandlerTraits<decltype(
764 &std::remove_reference<HandlerT>::type::operator())> {};
765
766// Specialization functions of the form 'Error (const ErrT&)'.
767template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
768public:
769 static bool appliesTo(const ErrorInfoBase &E) {
770 return E.template isA<ErrT>();
771 }
772
773 template <typename HandlerT>
774 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
775 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 775, __PRETTY_FUNCTION__))
;
776 return H(static_cast<ErrT &>(*E));
777 }
778};
779
780// Specialization functions of the form 'void (const ErrT&)'.
781template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
782public:
783 static bool appliesTo(const ErrorInfoBase &E) {
784 return E.template isA<ErrT>();
785 }
786
787 template <typename HandlerT>
788 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
789 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 789, __PRETTY_FUNCTION__))
;
790 H(static_cast<ErrT &>(*E));
791 return Error::success();
792 }
793};
794
795/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
796template <typename ErrT>
797class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
798public:
799 static bool appliesTo(const ErrorInfoBase &E) {
800 return E.template isA<ErrT>();
801 }
802
803 template <typename HandlerT>
804 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
805 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 805, __PRETTY_FUNCTION__))
;
806 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
807 return H(std::move(SubE));
808 }
809};
810
811/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
812template <typename ErrT>
813class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
814public:
815 static bool appliesTo(const ErrorInfoBase &E) {
816 return E.template isA<ErrT>();
817 }
818
819 template <typename HandlerT>
820 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
821 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 821, __PRETTY_FUNCTION__))
;
822 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
823 H(std::move(SubE));
824 return Error::success();
825 }
826};
827
828// Specialization for member functions of the form 'RetT (const ErrT&)'.
829template <typename C, typename RetT, typename ErrT>
830class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
831 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
832
833// Specialization for member functions of the form 'RetT (const ErrT&) const'.
834template <typename C, typename RetT, typename ErrT>
835class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
836 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
837
838// Specialization for member functions of the form 'RetT (const ErrT&)'.
839template <typename C, typename RetT, typename ErrT>
840class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
841 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
842
843// Specialization for member functions of the form 'RetT (const ErrT&) const'.
844template <typename C, typename RetT, typename ErrT>
845class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
846 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
847
848/// Specialization for member functions of the form
849/// 'RetT (std::unique_ptr<ErrT>)'.
850template <typename C, typename RetT, typename ErrT>
851class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
852 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
853
854/// Specialization for member functions of the form
855/// 'RetT (std::unique_ptr<ErrT>) const'.
856template <typename C, typename RetT, typename ErrT>
857class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
858 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
859
860inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
861 return Error(std::move(Payload));
862}
863
864template <typename HandlerT, typename... HandlerTs>
865Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
866 HandlerT &&Handler, HandlerTs &&... Handlers) {
867 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
868 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
869 std::move(Payload));
870 return handleErrorImpl(std::move(Payload),
871 std::forward<HandlerTs>(Handlers)...);
872}
873
874/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
875/// unhandled errors (or Errors returned by handlers) are re-concatenated and
876/// returned.
877/// Because this function returns an error, its result must also be checked
878/// or returned. If you intend to handle all errors use handleAllErrors
879/// (which returns void, and will abort() on unhandled errors) instead.
880template <typename... HandlerTs>
881Error handleErrors(Error E, HandlerTs &&... Hs) {
882 if (!E)
883 return Error::success();
884
885 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
886
887 if (Payload->isA<ErrorList>()) {
888 ErrorList &List = static_cast<ErrorList &>(*Payload);
889 Error R;
890 for (auto &P : List.Payloads)
891 R = ErrorList::join(
892 std::move(R),
893 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
894 return R;
895 }
896
897 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
898}
899
900/// Behaves the same as handleErrors, except that by contract all errors
901/// *must* be handled by the given handlers (i.e. there must be no remaining
902/// errors after running the handlers, or llvm_unreachable is called).
903template <typename... HandlerTs>
904void handleAllErrors(Error E, HandlerTs &&... Handlers) {
905 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
906}
907
908/// Check that E is a non-error, then drop it.
909/// If E is an error, llvm_unreachable will be called.
910inline void handleAllErrors(Error E) {
911 cantFail(std::move(E));
912}
913
914/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
915///
916/// If the incoming value is a success value it is returned unmodified. If it
917/// is a failure value then it the contained error is passed to handleErrors.
918/// If handleErrors is able to handle the error then the RecoveryPath functor
919/// is called to supply the final result. If handleErrors is not able to
920/// handle all errors then the unhandled errors are returned.
921///
922/// This utility enables the follow pattern:
923///
924/// @code{.cpp}
925/// enum FooStrategy { Aggressive, Conservative };
926/// Expected<Foo> foo(FooStrategy S);
927///
928/// auto ResultOrErr =
929/// handleExpected(
930/// foo(Aggressive),
931/// []() { return foo(Conservative); },
932/// [](AggressiveStrategyError&) {
933/// // Implicitly conusme this - we'll recover by using a conservative
934/// // strategy.
935/// });
936///
937/// @endcode
938template <typename T, typename RecoveryFtor, typename... HandlerTs>
939Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
940 HandlerTs &&... Handlers) {
941 if (ValOrErr)
942 return ValOrErr;
943
944 if (auto Err = handleErrors(ValOrErr.takeError(),
945 std::forward<HandlerTs>(Handlers)...))
946 return std::move(Err);
947
948 return RecoveryPath();
949}
950
951/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
952/// will be printed before the first one is logged. A newline will be printed
953/// after each error.
954///
955/// This function is compatible with the helpers from Support/WithColor.h. You
956/// can pass any of them as the OS. Please consider using them instead of
957/// including 'error: ' in the ErrorBanner.
958///
959/// This is useful in the base level of your program to allow clean termination
960/// (allowing clean deallocation of resources, etc.), while reporting error
961/// information to the user.
962void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
963
964/// Write all error messages (if any) in E to a string. The newline character
965/// is used to separate error messages.
966inline std::string toString(Error E) {
967 SmallVector<std::string, 2> Errors;
968 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
969 Errors.push_back(EI.message());
970 });
971 return join(Errors.begin(), Errors.end(), "\n");
972}
973
974/// Consume a Error without doing anything. This method should be used
975/// only where an error can be considered a reasonable and expected return
976/// value.
977///
978/// Uses of this method are potentially indicative of design problems: If it's
979/// legitimate to do nothing while processing an "error", the error-producer
980/// might be more clearly refactored to return an Optional<T>.
981inline void consumeError(Error Err) {
982 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
983}
984
985/// Convert an Expected to an Optional without doing anything. This method
986/// should be used only where an error can be considered a reasonable and
987/// expected return value.
988///
989/// Uses of this method are potentially indicative of problems: perhaps the
990/// error should be propagated further, or the error-producer should just
991/// return an Optional in the first place.
992template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
993 if (E)
994 return std::move(*E);
995 consumeError(E.takeError());
996 return None;
997}
998
999/// Helper for converting an Error to a bool.
1000///
1001/// This method returns true if Err is in an error state, or false if it is
1002/// in a success state. Puts Err in a checked state in both cases (unlike
1003/// Error::operator bool(), which only does this for success states).
1004inline bool errorToBool(Error Err) {
1005 bool IsError = static_cast<bool>(Err);
1006 if (IsError)
1007 consumeError(std::move(Err));
1008 return IsError;
1009}
1010
1011/// Helper for Errors used as out-parameters.
1012///
1013/// This helper is for use with the Error-as-out-parameter idiom, where an error
1014/// is passed to a function or method by reference, rather than being returned.
1015/// In such cases it is helpful to set the checked bit on entry to the function
1016/// so that the error can be written to (unchecked Errors abort on assignment)
1017/// and clear the checked bit on exit so that clients cannot accidentally forget
1018/// to check the result. This helper performs these actions automatically using
1019/// RAII:
1020///
1021/// @code{.cpp}
1022/// Result foo(Error &Err) {
1023/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1024/// // <body of foo>
1025/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1026/// }
1027/// @endcode
1028///
1029/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1030/// used with optional Errors (Error pointers that are allowed to be null). If
1031/// ErrorAsOutParameter took an Error reference, an instance would have to be
1032/// created inside every condition that verified that Error was non-null. By
1033/// taking an Error pointer we can just create one instance at the top of the
1034/// function.
1035class ErrorAsOutParameter {
1036public:
1037 ErrorAsOutParameter(Error *Err) : Err(Err) {
1038 // Raise the checked bit if Err is success.
1039 if (Err)
1040 (void)!!*Err;
1041 }
1042
1043 ~ErrorAsOutParameter() {
1044 // Clear the checked bit.
1045 if (Err && !*Err)
1046 *Err = Error::success();
1047 }
1048
1049private:
1050 Error *Err;
1051};
1052
1053/// Helper for Expected<T>s used as out-parameters.
1054///
1055/// See ErrorAsOutParameter.
1056template <typename T>
1057class ExpectedAsOutParameter {
1058public:
1059 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1060 : ValOrErr(ValOrErr) {
1061 if (ValOrErr)
1062 (void)!!*ValOrErr;
1063 }
1064
1065 ~ExpectedAsOutParameter() {
1066 if (ValOrErr)
1067 ValOrErr->setUnchecked();
1068 }
1069
1070private:
1071 Expected<T> *ValOrErr;
1072};
1073
1074/// This class wraps a std::error_code in a Error.
1075///
1076/// This is useful if you're writing an interface that returns a Error
1077/// (or Expected) and you want to call code that still returns
1078/// std::error_codes.
1079class ECError : public ErrorInfo<ECError> {
1080 friend Error errorCodeToError(std::error_code);
1081
1082 virtual void anchor() override;
1083
1084public:
1085 void setErrorCode(std::error_code EC) { this->EC = EC; }
1086 std::error_code convertToErrorCode() const override { return EC; }
1087 void log(raw_ostream &OS) const override { OS << EC.message(); }
1088
1089 // Used by ErrorInfo::classID.
1090 static char ID;
1091
1092protected:
1093 ECError() = default;
1094 ECError(std::error_code EC) : EC(EC) {}
1095
1096 std::error_code EC;
1097};
1098
1099/// The value returned by this function can be returned from convertToErrorCode
1100/// for Error values where no sensible translation to std::error_code exists.
1101/// It should only be used in this situation, and should never be used where a
1102/// sensible conversion to std::error_code is available, as attempts to convert
1103/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1104///error to try to convert such a value).
1105std::error_code inconvertibleErrorCode();
1106
1107/// Helper for converting an std::error_code to a Error.
1108Error errorCodeToError(std::error_code EC);
1109
1110/// Helper for converting an ECError to a std::error_code.
1111///
1112/// This method requires that Err be Error() or an ECError, otherwise it
1113/// will trigger a call to abort().
1114std::error_code errorToErrorCode(Error Err);
1115
1116/// Convert an ErrorOr<T> to an Expected<T>.
1117template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1118 if (auto EC = EO.getError())
1119 return errorCodeToError(EC);
1120 return std::move(*EO);
1121}
1122
1123/// Convert an Expected<T> to an ErrorOr<T>.
1124template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1125 if (auto Err = E.takeError())
1126 return errorToErrorCode(std::move(Err));
1127 return std::move(*E);
1128}
1129
1130/// This class wraps a string in an Error.
1131///
1132/// StringError is useful in cases where the client is not expected to be able
1133/// to consume the specific error message programmatically (for example, if the
1134/// error message is to be presented to the user).
1135///
1136/// StringError can also be used when additional information is to be printed
1137/// along with a error_code message. Depending on the constructor called, this
1138/// class can either display:
1139/// 1. the error_code message (ECError behavior)
1140/// 2. a string
1141/// 3. the error_code message and a string
1142///
1143/// These behaviors are useful when subtyping is required; for example, when a
1144/// specific library needs an explicit error type. In the example below,
1145/// PDBError is derived from StringError:
1146///
1147/// @code{.cpp}
1148/// Expected<int> foo() {
1149/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1150/// "Additional information");
1151/// }
1152/// @endcode
1153///
1154class StringError : public ErrorInfo<StringError> {
1155public:
1156 static char ID;
1157
1158 // Prints EC + S and converts to EC
1159 StringError(std::error_code EC, const Twine &S = Twine());
1160
1161 // Prints S and converts to EC
1162 StringError(const Twine &S, std::error_code EC);
1163
1164 void log(raw_ostream &OS) const override;
1165 std::error_code convertToErrorCode() const override;
1166
1167 const std::string &getMessage() const { return Msg; }
1168
1169private:
1170 std::string Msg;
1171 std::error_code EC;
1172 const bool PrintMsgOnly = false;
1173};
1174
1175/// Create formatted StringError object.
1176template <typename... Ts>
1177inline Error createStringError(std::error_code EC, char const *Fmt,
1178 const Ts &... Vals) {
1179 std::string Buffer;
1180 raw_string_ostream Stream(Buffer);
1181 Stream << format(Fmt, Vals...);
1182 return make_error<StringError>(Stream.str(), EC);
1183}
1184
1185Error createStringError(std::error_code EC, char const *Msg);
1186
1187inline Error createStringError(std::error_code EC, const Twine &S) {
1188 return createStringError(EC, S.str().c_str());
1189}
1190
1191template <typename... Ts>
1192inline Error createStringError(std::errc EC, char const *Fmt,
1193 const Ts &... Vals) {
1194 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1195}
1196
1197/// This class wraps a filename and another Error.
1198///
1199/// In some cases, an error needs to live along a 'source' name, in order to
1200/// show more detailed information to the user.
1201class FileError final : public ErrorInfo<FileError> {
1202
1203 friend Error createFileError(const Twine &, Error);
1204 friend Error createFileError(const Twine &, size_t, Error);
1205
1206public:
1207 void log(raw_ostream &OS) const override {
1208 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1208, __PRETTY_FUNCTION__))
;
1209 OS << "'" << FileName << "': ";
1210 if (Line.hasValue())
1211 OS << "line " << Line.getValue() << ": ";
1212 Err->log(OS);
1213 }
1214
1215 Error takeError() { return Error(std::move(Err)); }
1216
1217 std::error_code convertToErrorCode() const override;
1218
1219 // Used by ErrorInfo::classID.
1220 static char ID;
1221
1222private:
1223 FileError(const Twine &F, Optional<size_t> LineNum,
1224 std::unique_ptr<ErrorInfoBase> E) {
1225 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1225, __PRETTY_FUNCTION__))
;
1226 assert(!F.isTriviallyEmpty() &&((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1227, __PRETTY_FUNCTION__))
1227 "The file name provided to FileError must not be empty.")((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1227, __PRETTY_FUNCTION__))
;
1228 FileName = F.str();
1229 Err = std::move(E);
1230 Line = std::move(LineNum);
1231 }
1232
1233 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1234 return Error(
1235 std::unique_ptr<FileError>(new FileError(F, Line, E.takePayload())));
1236 }
1237
1238 std::string FileName;
1239 Optional<size_t> Line;
1240 std::unique_ptr<ErrorInfoBase> Err;
1241};
1242
1243/// Concatenate a source file path and/or name with an Error. The resulting
1244/// Error is unchecked.
1245inline Error createFileError(const Twine &F, Error E) {
1246 return FileError::build(F, Optional<size_t>(), std::move(E));
1247}
1248
1249/// Concatenate a source file path and/or name with line number and an Error.
1250/// The resulting Error is unchecked.
1251inline Error createFileError(const Twine &F, size_t Line, Error E) {
1252 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1253}
1254
1255/// Concatenate a source file path and/or name with a std::error_code
1256/// to form an Error object.
1257inline Error createFileError(const Twine &F, std::error_code EC) {
1258 return createFileError(F, errorCodeToError(EC));
1259}
1260
1261/// Concatenate a source file path and/or name with line number and
1262/// std::error_code to form an Error object.
1263inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1264 return createFileError(F, Line, errorCodeToError(EC));
1265}
1266
1267Error createFileError(const Twine &F, ErrorSuccess) = delete;
1268
1269/// Helper for check-and-exit error handling.
1270///
1271/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1272///
1273class ExitOnError {
1274public:
1275 /// Create an error on exit helper.
1276 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1277 : Banner(std::move(Banner)),
1278 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1279
1280 /// Set the banner string for any errors caught by operator().
1281 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1282
1283 /// Set the exit-code mapper function.
1284 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1285 this->GetExitCode = std::move(GetExitCode);
1286 }
1287
1288 /// Check Err. If it's in a failure state log the error(s) and exit.
1289 void operator()(Error Err) const { checkError(std::move(Err)); }
1290
1291 /// Check E. If it's in a success state then return the contained value. If
1292 /// it's in a failure state log the error(s) and exit.
1293 template <typename T> T operator()(Expected<T> &&E) const {
1294 checkError(E.takeError());
1295 return std::move(*E);
1296 }
1297
1298 /// Check E. If it's in a success state then return the contained reference. If
1299 /// it's in a failure state log the error(s) and exit.
1300 template <typename T> T& operator()(Expected<T&> &&E) const {
1301 checkError(E.takeError());
1302 return *E;
1303 }
1304
1305private:
1306 void checkError(Error Err) const {
1307 if (Err) {
1308 int ExitCode = GetExitCode(Err);
1309 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1310 exit(ExitCode);
1311 }
1312 }
1313
1314 std::string Banner;
1315 std::function<int(const Error &)> GetExitCode;
1316};
1317
1318/// Conversion from Error to LLVMErrorRef for C error bindings.
1319inline LLVMErrorRef wrap(Error Err) {
1320 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1321}
1322
1323/// Conversion from LLVMErrorRef to Error for C error bindings.
1324inline Error unwrap(LLVMErrorRef ErrRef) {
1325 return Error(std::unique_ptr<ErrorInfoBase>(
1326 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1327}
1328
1329} // end namespace llvm
1330
1331#endif // LLVM_SUPPORT_ERROR_H