Bug Summary

File:llvm/include/llvm/Bitstream/BitstreamReader.h
Warning:line 221, 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 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name BitstreamRemarkParser.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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/lib/Remarks -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/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-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/lib/Remarks -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-08-28-193554-24367-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Remarks/BitstreamRemarkParser.cpp

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Remarks/BitstreamRemarkParser.cpp

→
1//===- BitstreamRemarkParser.cpp ------------------------------------------===//
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 provides utility methods used by clients that want to use the
10// parser for remark diagnostics in LLVM.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Remarks/BitstreamRemarkParser.h"
15#include "BitstreamRemarkParser.h"
16#include "llvm/Support/MemoryBuffer.h"
17#include "llvm/Support/Path.h"
18
19using namespace llvm;
20using namespace llvm::remarks;
21
22static Error unknownRecord(const char *BlockName, unsigned RecordID) {
23 return createStringError(
24 std::make_error_code(std::errc::illegal_byte_sequence),
25 "Error while parsing %s: unknown record entry (%lu).", BlockName,
26 RecordID);
27}
28
29static Error malformedRecord(const char *BlockName, const char *RecordName) {
30 return createStringError(
31 std::make_error_code(std::errc::illegal_byte_sequence),
32 "Error while parsing %s: malformed record entry (%s).", BlockName,
33 RecordName);
34}
35
36BitstreamMetaParserHelper::BitstreamMetaParserHelper(
37 BitstreamCursor &Stream, BitstreamBlockInfo &BlockInfo)
38 : Stream(Stream), BlockInfo(BlockInfo) {}
39
40/// Parse a record and fill in the fields in the parser.
41static Error parseRecord(BitstreamMetaParserHelper &Parser, unsigned Code) {
42 BitstreamCursor &Stream = Parser.Stream;
43 // Note: 2 is used here because it's the max number of fields we have per
44 // record.
45 SmallVector<uint64_t, 2> Record;
46 StringRef Blob;
47 Expected<unsigned> RecordID = Stream.readRecord(Code, Record, &Blob);
48 if (!RecordID)
49 return RecordID.takeError();
50
51 switch (*RecordID) {
52 case RECORD_META_CONTAINER_INFO: {
53 if (Record.size() != 2)
54 return malformedRecord("BLOCK_META", "RECORD_META_CONTAINER_INFO");
55 Parser.ContainerVersion = Record[0];
56 Parser.ContainerType = Record[1];
57 break;
58 }
59 case RECORD_META_REMARK_VERSION: {
60 if (Record.size() != 1)
61 return malformedRecord("BLOCK_META", "RECORD_META_REMARK_VERSION");
62 Parser.RemarkVersion = Record[0];
63 break;
64 }
65 case RECORD_META_STRTAB: {
66 if (Record.size() != 0)
67 return malformedRecord("BLOCK_META", "RECORD_META_STRTAB");
68 Parser.StrTabBuf = Blob;
69 break;
70 }
71 case RECORD_META_EXTERNAL_FILE: {
72 if (Record.size() != 0)
73 return malformedRecord("BLOCK_META", "RECORD_META_EXTERNAL_FILE");
74 Parser.ExternalFilePath = Blob;
75 break;
76 }
77 default:
78 return unknownRecord("BLOCK_META", *RecordID);
79 }
80 return Error::success();
81}
82
83BitstreamRemarkParserHelper::BitstreamRemarkParserHelper(
84 BitstreamCursor &Stream)
85 : Stream(Stream) {}
86
87/// Parse a record and fill in the fields in the parser.
88static Error parseRecord(BitstreamRemarkParserHelper &Parser, unsigned Code) {
89 BitstreamCursor &Stream = Parser.Stream;
90 // Note: 5 is used here because it's the max number of fields we have per
91 // record.
92 SmallVector<uint64_t, 5> Record;
93 StringRef Blob;
94 Expected<unsigned> RecordID = Stream.readRecord(Code, Record, &Blob);
95 if (!RecordID)
96 return RecordID.takeError();
97
98 switch (*RecordID) {
99 case RECORD_REMARK_HEADER: {
100 if (Record.size() != 4)
101 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_HEADER");
102 Parser.Type = Record[0];
103 Parser.RemarkNameIdx = Record[1];
104 Parser.PassNameIdx = Record[2];
105 Parser.FunctionNameIdx = Record[3];
106 break;
107 }
108 case RECORD_REMARK_DEBUG_LOC: {
109 if (Record.size() != 3)
110 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_DEBUG_LOC");
111 Parser.SourceFileNameIdx = Record[0];
112 Parser.SourceLine = Record[1];
113 Parser.SourceColumn = Record[2];
114 break;
115 }
116 case RECORD_REMARK_HOTNESS: {
117 if (Record.size() != 1)
118 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_HOTNESS");
119 Parser.Hotness = Record[0];
120 break;
121 }
122 case RECORD_REMARK_ARG_WITH_DEBUGLOC: {
123 if (Record.size() != 5)
124 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_ARG_WITH_DEBUGLOC");
125 // Create a temporary argument. Use that as a valid memory location for this
126 // argument entry.
127 Parser.TmpArgs.emplace_back();
128 Parser.TmpArgs.back().KeyIdx = Record[0];
129 Parser.TmpArgs.back().ValueIdx = Record[1];
130 Parser.TmpArgs.back().SourceFileNameIdx = Record[2];
131 Parser.TmpArgs.back().SourceLine = Record[3];
132 Parser.TmpArgs.back().SourceColumn = Record[4];
133 Parser.Args =
134 ArrayRef<BitstreamRemarkParserHelper::Argument>(Parser.TmpArgs);
135 break;
136 }
137 case RECORD_REMARK_ARG_WITHOUT_DEBUGLOC: {
138 if (Record.size() != 2)
139 return malformedRecord("BLOCK_REMARK",
140 "RECORD_REMARK_ARG_WITHOUT_DEBUGLOC");
141 // Create a temporary argument. Use that as a valid memory location for this
142 // argument entry.
143 Parser.TmpArgs.emplace_back();
144 Parser.TmpArgs.back().KeyIdx = Record[0];
145 Parser.TmpArgs.back().ValueIdx = Record[1];
146 Parser.Args =
147 ArrayRef<BitstreamRemarkParserHelper::Argument>(Parser.TmpArgs);
148 break;
149 }
150 default:
151 return unknownRecord("BLOCK_REMARK", *RecordID);
152 }
153 return Error::success();
154}
155
156template <typename T>
157static Error parseBlock(T &ParserHelper, unsigned BlockID,
158 const char *BlockName) {
159 BitstreamCursor &Stream = ParserHelper.Stream;
160 Expected<BitstreamEntry> Next = Stream.advance();
161 if (!Next)
162 return Next.takeError();
163 if (Next->Kind != BitstreamEntry::SubBlock || Next->ID != BlockID)
164 return createStringError(
165 std::make_error_code(std::errc::illegal_byte_sequence),
166 "Error while parsing %s: expecting [ENTER_SUBBLOCK, %s, ...].",
167 BlockName, BlockName);
168 if (Stream.EnterSubBlock(BlockID))
169 return createStringError(
170 std::make_error_code(std::errc::illegal_byte_sequence),
171 "Error while entering %s.", BlockName);
172
173 // Stop when there is nothing to read anymore or when we encounter an
174 // END_BLOCK.
175 while (!Stream.AtEndOfStream()) {
176 Next = Stream.advance();
177 if (!Next)
178 return Next.takeError();
179 switch (Next->Kind) {
180 case BitstreamEntry::EndBlock:
181 return Error::success();
182 case BitstreamEntry::Error:
183 case BitstreamEntry::SubBlock:
184 return createStringError(
185 std::make_error_code(std::errc::illegal_byte_sequence),
186 "Error while parsing %s: expecting records.", BlockName);
187 case BitstreamEntry::Record:
188 if (Error E = parseRecord(ParserHelper, Next->ID))
189 return E;
190 continue;
191 }
192 }
193 // If we're here, it means we didn't get an END_BLOCK yet, but we're at the
194 // end of the stream. In this case, error.
195 return createStringError(
196 std::make_error_code(std::errc::illegal_byte_sequence),
197 "Error while parsing %s: unterminated block.", BlockName);
198}
199
200Error BitstreamMetaParserHelper::parse() {
201 return parseBlock(*this, META_BLOCK_ID, "META_BLOCK");
202}
203
204Error BitstreamRemarkParserHelper::parse() {
205 return parseBlock(*this, REMARK_BLOCK_ID, "REMARK_BLOCK");
206}
207
208BitstreamParserHelper::BitstreamParserHelper(StringRef Buffer)
209 : Stream(Buffer) {}
210
211Expected<std::array<char, 4>> BitstreamParserHelper::parseMagic() {
212 std::array<char, 4> Result;
213 for (unsigned i = 0; i < 4; ++i)
2
←
Loop condition is true. Entering loop body
→
214 if (Expected<unsigned> R = Stream.Read(8))
3
←
Calling 'SimpleBitstreamCursor::Read'
→
215 Result[i] = *R;
216 else
217 return R.takeError();
218 return Result;
219}
220
221Error BitstreamParserHelper::parseBlockInfoBlock() {
222 Expected<BitstreamEntry> Next = Stream.advance();
223 if (!Next)
224 return Next.takeError();
225 if (Next->Kind != BitstreamEntry::SubBlock ||
226 Next->ID != llvm::bitc::BLOCKINFO_BLOCK_ID)
227 return createStringError(
228 std::make_error_code(std::errc::illegal_byte_sequence),
229 "Error while parsing BLOCKINFO_BLOCK: expecting [ENTER_SUBBLOCK, "
230 "BLOCKINFO_BLOCK, ...].");
231
232 Expected<Optional<BitstreamBlockInfo>> MaybeBlockInfo =
233 Stream.ReadBlockInfoBlock();
234 if (!MaybeBlockInfo)
235 return MaybeBlockInfo.takeError();
236
237 if (!*MaybeBlockInfo)
238 return createStringError(
239 std::make_error_code(std::errc::illegal_byte_sequence),
240 "Error while parsing BLOCKINFO_BLOCK.");
241
242 BlockInfo = **MaybeBlockInfo;
243
244 Stream.setBlockInfo(&BlockInfo);
245 return Error::success();
246}
247
248static Expected<bool> isBlock(BitstreamCursor &Stream, unsigned BlockID) {
249 bool Result = false;
250 uint64_t PreviousBitNo = Stream.GetCurrentBitNo();
251 Expected<BitstreamEntry> Next = Stream.advance();
252 if (!Next)
253 return Next.takeError();
254 switch (Next->Kind) {
255 case BitstreamEntry::SubBlock:
256 // Check for the block id.
257 Result = Next->ID == BlockID;
258 break;
259 case BitstreamEntry::Error:
260 return createStringError(
261 std::make_error_code(std::errc::illegal_byte_sequence),
262 "Unexpected error while parsing bitstream.");
263 default:
264 Result = false;
265 break;
266 }
267 if (Error E = Stream.JumpToBit(PreviousBitNo))
268 return std::move(E);
269 return Result;
270}
271
272Expected<bool> BitstreamParserHelper::isMetaBlock() {
273 return isBlock(Stream, META_BLOCK_ID);
274}
275
276Expected<bool> BitstreamParserHelper::isRemarkBlock() {
277 return isBlock(Stream, META_BLOCK_ID);
278}
279
280static Error validateMagicNumber(StringRef MagicNumber) {
281 if (MagicNumber != remarks::ContainerMagic)
282 return createStringError(std::make_error_code(std::errc::invalid_argument),
283 "Unknown magic number: expecting %s, got %.4s.",
284 remarks::ContainerMagic.data(), MagicNumber.data());
285 return Error::success();
286}
287
288static Error advanceToMetaBlock(BitstreamParserHelper &Helper) {
289 Expected<std::array<char, 4>> MagicNumber = Helper.parseMagic();
290 if (!MagicNumber)
291 return MagicNumber.takeError();
292 if (Error E = validateMagicNumber(
293 StringRef(MagicNumber->data(), MagicNumber->size())))
294 return E;
295 if (Error E = Helper.parseBlockInfoBlock())
296 return E;
297 Expected<bool> isMetaBlock = Helper.isMetaBlock();
298 if (!isMetaBlock)
299 return isMetaBlock.takeError();
300 if (!*isMetaBlock)
301 return createStringError(
302 std::make_error_code(std::errc::illegal_byte_sequence),
303 "Expecting META_BLOCK after the BLOCKINFO_BLOCK.");
304 return Error::success();
305}
306
307Expected<std::unique_ptr<BitstreamRemarkParser>>
308remarks::createBitstreamParserFromMeta(
309 StringRef Buf, Optional<ParsedStringTable> StrTab,
310 Optional<StringRef> ExternalFilePrependPath) {
311 BitstreamParserHelper Helper(Buf);
312 Expected<std::array<char, 4>> MagicNumber = Helper.parseMagic();
1
Calling 'BitstreamParserHelper::parseMagic'
→
313 if (!MagicNumber)
314 return MagicNumber.takeError();
315
316 if (Error E = validateMagicNumber(
317 StringRef(MagicNumber->data(), MagicNumber->size())))
318 return std::move(E);
319
320 auto Parser =
321 StrTab ? std::make_unique<BitstreamRemarkParser>(Buf, std::move(*StrTab))
322 : std::make_unique<BitstreamRemarkParser>(Buf);
323
324 if (ExternalFilePrependPath)
325 Parser->ExternalFilePrependPath = std::string(*ExternalFilePrependPath);
326
327 return std::move(Parser);
328}
329
330Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::next() {
331 if (ParserHelper.atEndOfStream())
332 return make_error<EndOfFileError>();
333
334 if (!ReadyToParseRemarks) {
335 if (Error E = parseMeta())
336 return std::move(E);
337 ReadyToParseRemarks = true;
338 }
339
340 return parseRemark();
341}
342
343Error BitstreamRemarkParser::parseMeta() {
344 // Advance and to the meta block.
345 if (Error E = advanceToMetaBlock(ParserHelper))
346 return E;
347
348 BitstreamMetaParserHelper MetaHelper(ParserHelper.Stream,
349 ParserHelper.BlockInfo);
350 if (Error E = MetaHelper.parse())
351 return E;
352
353 if (Error E = processCommonMeta(MetaHelper))
354 return E;
355
356 switch (ContainerType) {
357 case BitstreamRemarkContainerType::Standalone:
358 return processStandaloneMeta(MetaHelper);
359 case BitstreamRemarkContainerType::SeparateRemarksFile:
360 return processSeparateRemarksFileMeta(MetaHelper);
361 case BitstreamRemarkContainerType::SeparateRemarksMeta:
362 return processSeparateRemarksMetaMeta(MetaHelper);
363 }
364 llvm_unreachable("Unknown BitstreamRemarkContainerType enum")::llvm::llvm_unreachable_internal("Unknown BitstreamRemarkContainerType enum"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Remarks/BitstreamRemarkParser.cpp"
, 364);
365}
366
367Error BitstreamRemarkParser::processCommonMeta(
368 BitstreamMetaParserHelper &Helper) {
369 if (Optional<uint64_t> Version = Helper.ContainerVersion)
370 ContainerVersion = *Version;
371 else
372 return createStringError(
373 std::make_error_code(std::errc::illegal_byte_sequence),
374 "Error while parsing BLOCK_META: missing container version.");
375
376 if (Optional<uint8_t> Type = Helper.ContainerType) {
377 // Always >= BitstreamRemarkContainerType::First since it's unsigned.
378 if (*Type > static_cast<uint8_t>(BitstreamRemarkContainerType::Last))
379 return createStringError(
380 std::make_error_code(std::errc::illegal_byte_sequence),
381 "Error while parsing BLOCK_META: invalid container type.");
382
383 ContainerType = static_cast<BitstreamRemarkContainerType>(*Type);
384 } else
385 return createStringError(
386 std::make_error_code(std::errc::illegal_byte_sequence),
387 "Error while parsing BLOCK_META: missing container type.");
388
389 return Error::success();
390}
391
392static Error processStrTab(BitstreamRemarkParser &P,
393 Optional<StringRef> StrTabBuf) {
394 if (!StrTabBuf)
395 return createStringError(
396 std::make_error_code(std::errc::illegal_byte_sequence),
397 "Error while parsing BLOCK_META: missing string table.");
398 // Parse and assign the string table.
399 P.StrTab.emplace(*StrTabBuf);
400 return Error::success();
401}
402
403static Error processRemarkVersion(BitstreamRemarkParser &P,
404 Optional<uint64_t> RemarkVersion) {
405 if (!RemarkVersion)
406 return createStringError(
407 std::make_error_code(std::errc::illegal_byte_sequence),
408 "Error while parsing BLOCK_META: missing remark version.");
409 P.RemarkVersion = *RemarkVersion;
410 return Error::success();
411}
412
413Error BitstreamRemarkParser::processExternalFilePath(
414 Optional<StringRef> ExternalFilePath) {
415 if (!ExternalFilePath)
416 return createStringError(
417 std::make_error_code(std::errc::illegal_byte_sequence),
418 "Error while parsing BLOCK_META: missing external file path.");
419
420 SmallString<80> FullPath(ExternalFilePrependPath);
421 sys::path::append(FullPath, *ExternalFilePath);
422
423 // External file: open the external file, parse it, check if its metadata
424 // matches the one from the separate metadata, then replace the current parser
425 // with the one parsing the remarks.
426 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
427 MemoryBuffer::getFile(FullPath);
428 if (std::error_code EC = BufferOrErr.getError())
429 return createFileError(FullPath, EC);
430
431 TmpRemarkBuffer = std::move(*BufferOrErr);
432
433 // Don't try to parse the file if it's empty.
434 if (TmpRemarkBuffer->getBufferSize() == 0)
435 return make_error<EndOfFileError>();
436
437 // Create a separate parser used for parsing the separate file.
438 ParserHelper = BitstreamParserHelper(TmpRemarkBuffer->getBuffer());
439 // Advance and check until we can parse the meta block.
440 if (Error E = advanceToMetaBlock(ParserHelper))
441 return E;
442 // Parse the meta from the separate file.
443 // Note: here we overwrite the BlockInfo with the one from the file. This will
444 // be used to parse the rest of the file.
445 BitstreamMetaParserHelper SeparateMetaHelper(ParserHelper.Stream,
446 ParserHelper.BlockInfo);
447 if (Error E = SeparateMetaHelper.parse())
448 return E;
449
450 uint64_t PreviousContainerVersion = ContainerVersion;
451 if (Error E = processCommonMeta(SeparateMetaHelper))
452 return E;
453
454 if (ContainerType != BitstreamRemarkContainerType::SeparateRemarksFile)
455 return createStringError(
456 std::make_error_code(std::errc::illegal_byte_sequence),
457 "Error while parsing external file's BLOCK_META: wrong container "
458 "type.");
459
460 if (PreviousContainerVersion != ContainerVersion)
461 return createStringError(
462 std::make_error_code(std::errc::illegal_byte_sequence),
463 "Error while parsing external file's BLOCK_META: mismatching versions: "
464 "original meta: %lu, external file meta: %lu.",
465 PreviousContainerVersion, ContainerVersion);
466
467 // Process the meta from the separate file.
468 return processSeparateRemarksFileMeta(SeparateMetaHelper);
469}
470
471Error BitstreamRemarkParser::processStandaloneMeta(
472 BitstreamMetaParserHelper &Helper) {
473 if (Error E = processStrTab(*this, Helper.StrTabBuf))
474 return E;
475 return processRemarkVersion(*this, Helper.RemarkVersion);
476}
477
478Error BitstreamRemarkParser::processSeparateRemarksFileMeta(
479 BitstreamMetaParserHelper &Helper) {
480 return processRemarkVersion(*this, Helper.RemarkVersion);
481}
482
483Error BitstreamRemarkParser::processSeparateRemarksMetaMeta(
484 BitstreamMetaParserHelper &Helper) {
485 if (Error E = processStrTab(*this, Helper.StrTabBuf))
486 return E;
487 return processExternalFilePath(Helper.ExternalFilePath);
488}
489
490Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::parseRemark() {
491 BitstreamRemarkParserHelper RemarkHelper(ParserHelper.Stream);
492 if (Error E = RemarkHelper.parse())
493 return std::move(E);
494
495 return processRemark(RemarkHelper);
496}
497
498Expected<std::unique_ptr<Remark>>
499BitstreamRemarkParser::processRemark(BitstreamRemarkParserHelper &Helper) {
500 std::unique_ptr<Remark> Result = std::make_unique<Remark>();
501 Remark &R = *Result;
502
503 if (StrTab == None)
504 return createStringError(
505 std::make_error_code(std::errc::invalid_argument),
506 "Error while parsing BLOCK_REMARK: missing string table.");
507
508 if (!Helper.Type)
509 return createStringError(
510 std::make_error_code(std::errc::illegal_byte_sequence),
511 "Error while parsing BLOCK_REMARK: missing remark type.");
512
513 // Always >= Type::First since it's unsigned.
514 if (*Helper.Type > static_cast<uint8_t>(Type::Last))
515 return createStringError(
516 std::make_error_code(std::errc::illegal_byte_sequence),
517 "Error while parsing BLOCK_REMARK: unknown remark type.");
518
519 R.RemarkType = static_cast<Type>(*Helper.Type);
520
521 if (!Helper.RemarkNameIdx)
522 return createStringError(
523 std::make_error_code(std::errc::illegal_byte_sequence),
524 "Error while parsing BLOCK_REMARK: missing remark name.");
525
526 if (Expected<StringRef> RemarkName = (*StrTab)[*Helper.RemarkNameIdx])
527 R.RemarkName = *RemarkName;
528 else
529 return RemarkName.takeError();
530
531 if (!Helper.PassNameIdx)
532 return createStringError(
533 std::make_error_code(std::errc::illegal_byte_sequence),
534 "Error while parsing BLOCK_REMARK: missing remark pass.");
535
536 if (Expected<StringRef> PassName = (*StrTab)[*Helper.PassNameIdx])
537 R.PassName = *PassName;
538 else
539 return PassName.takeError();
540
541 if (!Helper.FunctionNameIdx)
542 return createStringError(
543 std::make_error_code(std::errc::illegal_byte_sequence),
544 "Error while parsing BLOCK_REMARK: missing remark function name.");
545 if (Expected<StringRef> FunctionName = (*StrTab)[*Helper.FunctionNameIdx])
546 R.FunctionName = *FunctionName;
547 else
548 return FunctionName.takeError();
549
550 if (Helper.SourceFileNameIdx && Helper.SourceLine && Helper.SourceColumn) {
551 Expected<StringRef> SourceFileName = (*StrTab)[*Helper.SourceFileNameIdx];
552 if (!SourceFileName)
553 return SourceFileName.takeError();
554 R.Loc.emplace();
555 R.Loc->SourceFilePath = *SourceFileName;
556 R.Loc->SourceLine = *Helper.SourceLine;
557 R.Loc->SourceColumn = *Helper.SourceColumn;
558 }
559
560 if (Helper.Hotness)
561 R.Hotness = *Helper.Hotness;
562
563 if (!Helper.Args)
564 return std::move(Result);
565
566 for (const BitstreamRemarkParserHelper::Argument &Arg : *Helper.Args) {
567 if (!Arg.KeyIdx)
568 return createStringError(
569 std::make_error_code(std::errc::illegal_byte_sequence),
570 "Error while parsing BLOCK_REMARK: missing key in remark argument.");
571 if (!Arg.ValueIdx)
572 return createStringError(
573 std::make_error_code(std::errc::illegal_byte_sequence),
574 "Error while parsing BLOCK_REMARK: missing value in remark "
575 "argument.");
576
577 // We have at least a key and a value, create an entry.
578 R.Args.emplace_back();
579
580 if (Expected<StringRef> Key = (*StrTab)[*Arg.KeyIdx])
581 R.Args.back().Key = *Key;
582 else
583 return Key.takeError();
584
585 if (Expected<StringRef> Value = (*StrTab)[*Arg.ValueIdx])
586 R.Args.back().Val = *Value;
587 else
588 return Value.takeError();
589
590 if (Arg.SourceFileNameIdx && Arg.SourceLine && Arg.SourceColumn) {
591 if (Expected<StringRef> SourceFileName =
592 (*StrTab)[*Arg.SourceFileNameIdx]) {
593 R.Args.back().Loc.emplace();
594 R.Args.back().Loc->SourceFilePath = *SourceFileName;
595 R.Args.back().Loc->SourceLine = *Arg.SourceLine;
596 R.Args.back().Loc->SourceColumn = *Arg.SourceColumn;
597 } else
598 return SourceFileName.takeError();
599 }
600 }
601
602 return std::move(Result);
603}
←

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/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/Error.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <climits>
28#include <cstddef>
29#include <cstdint>
30#include <memory>
31#include <string>
32#include <utility>
33#include <vector>
34
35namespace llvm {
36
37/// This class maintains the abbreviations read from a block info block.
38class BitstreamBlockInfo {
39public:
40 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
41 /// describe abbreviations that all blocks of the specified ID inherit.
42 struct BlockInfo {
43 unsigned BlockID = 0;
44 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
45 std::string Name;
46 std::vector<std::pair<unsigned, std::string>> RecordNames;
47 };
48
49private:
50 std::vector<BlockInfo> BlockInfoRecords;
51
52public:
53 /// If there is block info for the specified ID, return it, otherwise return
54 /// null.
55 const BlockInfo *getBlockInfo(unsigned BlockID) const {
56 // Common case, the most recent entry matches BlockID.
57 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
58 return &BlockInfoRecords.back();
59
60 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
61 i != e; ++i)
62 if (BlockInfoRecords[i].BlockID == BlockID)
63 return &BlockInfoRecords[i];
64 return nullptr;
65 }
66
67 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
68 if (const BlockInfo *BI = getBlockInfo(BlockID))
69 return *const_cast<BlockInfo*>(BI);
70
71 // Otherwise, add a new record.
72 BlockInfoRecords.emplace_back();
73 BlockInfoRecords.back().BlockID = BlockID;
74 return BlockInfoRecords.back();
75 }
76};
77
78/// This represents a position within a bitstream. There may be multiple
79/// independent cursors reading within one bitstream, each maintaining their
80/// own local state.
81class SimpleBitstreamCursor {
82 ArrayRef<uint8_t> BitcodeBytes;
83 size_t NextChar = 0;
84
85public:
86 /// This is the current data we have pulled from the stream but have not
87 /// returned to the client. This is specifically and intentionally defined to
88 /// follow the word size of the host machine for efficiency. We use word_t in
89 /// places that are aware of this to make it perfectly explicit what is going
90 /// on.
91 using word_t = size_t;
92
93private:
94 word_t CurWord = 0;
95
96 /// This is the number of bits in CurWord that are valid. This is always from
97 /// [0...bits_of(size_t)-1] inclusive.
98 unsigned BitsInCurWord = 0;
99
100public:
101 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
102
103 SimpleBitstreamCursor() = default;
104 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
105 : BitcodeBytes(BitcodeBytes) {}
106 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
107 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
108 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
109 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
110
111 bool canSkipToPos(size_t pos) const {
112 // pos can be skipped to if it is a valid address or one byte past the end.
113 return pos <= BitcodeBytes.size();
114 }
115
116 bool AtEndOfStream() {
117 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
118 }
119
120 /// Return the bit # of the bit we are reading.
121 uint64_t GetCurrentBitNo() const {
122 return NextChar*CHAR_BIT8 - BitsInCurWord;
123 }
124
125 // Return the byte # of the current bit.
126 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
127
128 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
129
130 /// Reset the stream to the specified bit number.
131 Error JumpToBit(uint64_t BitNo) {
132 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
133 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
134 assert(canSkipToPos(ByteNo) && "Invalid location")(static_cast <bool> (canSkipToPos(ByteNo) && "Invalid location"
) ? void (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 134, __extension__ __PRETTY_FUNCTION__));
135
136 // Move the cursor to the right word.
137 NextChar = ByteNo;
138 BitsInCurWord = 0;
139
140 // Skip over any bits that are already consumed.
141 if (WordBitNo) {
142 if (Expected<word_t> Res = Read(WordBitNo))
143 return Error::success();
144 else
145 return Res.takeError();
146 }
147
148 return Error::success();
149 }
150
151 /// Get a pointer into the bitstream at the specified byte offset.
152 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
153 return BitcodeBytes.data() + ByteNo;
154 }
155
156 /// Get a pointer into the bitstream at the specified bit offset.
157 ///
158 /// The bit offset must be on a byte boundary.
159 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
160 assert(!(BitNo % 8) && "Expected bit on byte boundary")(static_cast <bool> (!(BitNo % 8) && "Expected bit on byte boundary"
) ? void (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 160, __extension__ __PRETTY_FUNCTION__));
161 return getPointerToByte(BitNo / 8, NumBytes);
162 }
163
164 Error fillCurWord() {
165 if (NextChar >= BitcodeBytes.size())
166 return createStringError(std::errc::io_error,
167 "Unexpected end of file reading %u of %u bytes",
168 NextChar, BitcodeBytes.size());
169
170 // Read the next word from the stream.
171 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
172 unsigned BytesRead;
173 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
174 BytesRead = sizeof(word_t);
175 CurWord =
176 support::endian::read<word_t, support::little, support::unaligned>(
177 NextCharPtr);
178 } else {
179 // Short read.
180 BytesRead = BitcodeBytes.size() - NextChar;
181 CurWord = 0;
182 for (unsigned B = 0; B != BytesRead; ++B)
183 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
184 }
185 NextChar += BytesRead;
186 BitsInCurWord = BytesRead * 8;
187 return Error::success();
188 }
189
190 Expected<word_t> Read(unsigned NumBits) {
191 static const unsigned BitsInWord = MaxChunkSize;
192
193 assert(NumBits && NumBits <= BitsInWord &&(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __extension__ __PRETTY_FUNCTION__))
4
←
'?' condition is true
→
194 "Cannot return zero or more than BitsInWord bits!")(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __extension__ __PRETTY_FUNCTION__));
195
196 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
5
←
'?' condition is true
→
197
198 // If the field is fully contained by CurWord, return it quickly.
199 if (BitsInCurWord >= NumBits) {
6
←
Assuming 'NumBits' is > field 'BitsInCurWord'
→
200 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
201
202 // Use a mask to avoid undefined behavior.
203 CurWord >>= (NumBits & Mask);
204
205 BitsInCurWord -= NumBits;
206 return R;
207 }
208
209 word_t R = BitsInCurWord ? CurWord : 0;
7
←
Taking false branch
→
8
←
Assuming field 'BitsInCurWord' is not equal to 0
→
9
←
'?' condition is true
→
210 unsigned BitsLeft = NumBits - BitsInCurWord;
211
212 if (Error fillResult = fillCurWord())
10
←
Calling 'Error::operator bool'
→
12
←
Returning from 'Error::operator bool'
→
13
←
Taking false branch
→
213 return std::move(fillResult);
214
215 // If we run out of data, abort.
216 if (BitsLeft > BitsInCurWord)
14
←
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
→
15
←
Taking false branch
→
217 return createStringError(std::errc::io_error,
218 "Unexpected end of file reading %u of %u bits",
219 BitsInCurWord, BitsLeft);
220
221 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'
222
223 // Use a mask to avoid undefined behavior.
224 CurWord >>= (BitsLeft & Mask);
225
226 BitsInCurWord -= BitsLeft;
227
228 R |= R2 << (NumBits - BitsLeft);
229
230 return R;
231 }
232
233 Expected<uint32_t> ReadVBR(unsigned NumBits) {
234 Expected<unsigned> MaybeRead = Read(NumBits);
235 if (!MaybeRead)
236 return MaybeRead;
237 uint32_t Piece = MaybeRead.get();
238
239 if ((Piece & (1U << (NumBits-1))) == 0)
240 return Piece;
241
242 uint32_t Result = 0;
243 unsigned NextBit = 0;
244 while (true) {
245 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
246
247 if ((Piece & (1U << (NumBits-1))) == 0)
248 return Result;
249
250 NextBit += NumBits-1;
251 MaybeRead = Read(NumBits);
252 if (!MaybeRead)
253 return MaybeRead;
254 Piece = MaybeRead.get();
255 }
256 }
257
258 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
259 // the VBR must still be <= 32 bits though.
260 Expected<uint64_t> ReadVBR64(unsigned NumBits) {
261 Expected<uint64_t> MaybeRead = Read(NumBits);
262 if (!MaybeRead)
263 return MaybeRead;
264 uint32_t Piece = MaybeRead.get();
265
266 if ((Piece & (1U << (NumBits-1))) == 0)
267 return uint64_t(Piece);
268
269 uint64_t Result = 0;
270 unsigned NextBit = 0;
271 while (true) {
272 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
273
274 if ((Piece & (1U << (NumBits-1))) == 0)
275 return Result;
276
277 NextBit += NumBits-1;
278 MaybeRead = Read(NumBits);
279 if (!MaybeRead)
280 return MaybeRead;
281 Piece = MaybeRead.get();
282 }
283 }
284
285 void SkipToFourByteBoundary() {
286 // If word_t is 64-bits and if we've read less than 32 bits, just dump
287 // the bits we have up to the next 32-bit boundary.
288 if (sizeof(word_t) > 4 &&
289 BitsInCurWord >= 32) {
290 CurWord >>= BitsInCurWord-32;
291 BitsInCurWord = 32;
292 return;
293 }
294
295 BitsInCurWord = 0;
296 }
297
298 /// Return the size of the stream in bytes.
299 size_t SizeInBytes() const { return BitcodeBytes.size(); }
300
301 /// Skip to the end of the file.
302 void skipToEnd() { NextChar = BitcodeBytes.size(); }
303};
304
305/// When advancing through a bitstream cursor, each advance can discover a few
306/// different kinds of entries:
307struct BitstreamEntry {
308 enum {
309 Error, // Malformed bitcode was found.
310 EndBlock, // We've reached the end of the current block, (or the end of the
311 // file, which is treated like a series of EndBlock records.
312 SubBlock, // This is the start of a new subblock of a specific ID.
313 Record // This is a record with a specific AbbrevID.
314 } Kind;
315
316 unsigned ID;
317
318 static BitstreamEntry getError() {
319 BitstreamEntry E; E.Kind = Error; return E;
320 }
321
322 static BitstreamEntry getEndBlock() {
323 BitstreamEntry E; E.Kind = EndBlock; return E;
324 }
325
326 static BitstreamEntry getSubBlock(unsigned ID) {
327 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
328 }
329
330 static BitstreamEntry getRecord(unsigned AbbrevID) {
331 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
332 }
333};
334
335/// This represents a position within a bitcode file, implemented on top of a
336/// SimpleBitstreamCursor.
337///
338/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
339/// be passed by value.
340class BitstreamCursor : SimpleBitstreamCursor {
341 // This is the declared size of code values used for the current block, in
342 // bits.
343 unsigned CurCodeSize = 2;
344
345 /// Abbrevs installed at in this block.
346 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
347
348 struct Block {
349 unsigned PrevCodeSize;
350 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
351
352 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
353 };
354
355 /// This tracks the codesize of parent blocks.
356 SmallVector<Block, 8> BlockScope;
357
358 BitstreamBlockInfo *BlockInfo = nullptr;
359
360public:
361 static const size_t MaxChunkSize = sizeof(word_t) * 8;
362
363 BitstreamCursor() = default;
364 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
365 : SimpleBitstreamCursor(BitcodeBytes) {}
366 explicit BitstreamCursor(StringRef BitcodeBytes)
367 : SimpleBitstreamCursor(BitcodeBytes) {}
368 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
369 : SimpleBitstreamCursor(BitcodeBytes) {}
370
371 using SimpleBitstreamCursor::AtEndOfStream;
372 using SimpleBitstreamCursor::canSkipToPos;
373 using SimpleBitstreamCursor::fillCurWord;
374 using SimpleBitstreamCursor::getBitcodeBytes;
375 using SimpleBitstreamCursor::GetCurrentBitNo;
376 using SimpleBitstreamCursor::getCurrentByteNo;
377 using SimpleBitstreamCursor::getPointerToByte;
378 using SimpleBitstreamCursor::JumpToBit;
379 using SimpleBitstreamCursor::Read;
380 using SimpleBitstreamCursor::ReadVBR;
381 using SimpleBitstreamCursor::ReadVBR64;
382 using SimpleBitstreamCursor::SizeInBytes;
383 using SimpleBitstreamCursor::skipToEnd;
384
385 /// Return the number of bits used to encode an abbrev #.
386 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
387
388 /// Flags that modify the behavior of advance().
389 enum {
390 /// If this flag is used, the advance() method does not automatically pop
391 /// the block scope when the end of a block is reached.
392 AF_DontPopBlockAtEnd = 1,
393
394 /// If this flag is used, abbrev entries are returned just like normal
395 /// records.
396 AF_DontAutoprocessAbbrevs = 2
397 };
398
399 /// Advance the current bitstream, returning the next entry in the stream.
400 Expected<BitstreamEntry> advance(unsigned Flags = 0) {
401 while (true) {
402 if (AtEndOfStream())
403 return BitstreamEntry::getError();
404
405 Expected<unsigned> MaybeCode = ReadCode();
406 if (!MaybeCode)
407 return MaybeCode.takeError();
408 unsigned Code = MaybeCode.get();
409
410 if (Code == bitc::END_BLOCK) {
411 // Pop the end of the block unless Flags tells us not to.
412 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
413 return BitstreamEntry::getError();
414 return BitstreamEntry::getEndBlock();
415 }
416
417 if (Code == bitc::ENTER_SUBBLOCK) {
418 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID())
419 return BitstreamEntry::getSubBlock(MaybeSubBlock.get());
420 else
421 return MaybeSubBlock.takeError();
422 }
423
424 if (Code == bitc::DEFINE_ABBREV &&
425 !(Flags & AF_DontAutoprocessAbbrevs)) {
426 // We read and accumulate abbrev's, the client can't do anything with
427 // them anyway.
428 if (Error Err = ReadAbbrevRecord())
429 return std::move(Err);
430 continue;
431 }
432
433 return BitstreamEntry::getRecord(Code);
434 }
435 }
436
437 /// This is a convenience function for clients that don't expect any
438 /// subblocks. This just skips over them automatically.
439 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) {
440 while (true) {
441 // If we found a normal entry, return it.
442 Expected<BitstreamEntry> MaybeEntry = advance(Flags);
443 if (!MaybeEntry)
444 return MaybeEntry;
445 BitstreamEntry Entry = MaybeEntry.get();
446
447 if (Entry.Kind != BitstreamEntry::SubBlock)
448 return Entry;
449
450 // If we found a sub-block, just skip over it and check the next entry.
451 if (Error Err = SkipBlock())
452 return std::move(Err);
453 }
454 }
455
456 Expected<unsigned> ReadCode() { return Read(CurCodeSize); }
457
458 // Block header:
459 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
460
461 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
462 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); }
463
464 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
465 /// of this block.
466 Error SkipBlock() {
467 // Read and ignore the codelen value.
468 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth))
469 ; // Since we are skipping this block, we don't care what code widths are
470 // used inside of it.
471 else
472 return Res.takeError();
473
474 SkipToFourByteBoundary();
475 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth);
476 if (!MaybeNum)
477 return MaybeNum.takeError();
478 size_t NumFourBytes = MaybeNum.get();
479
480 // Check that the block wasn't partially defined, and that the offset isn't
481 // bogus.
482 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8;
483 if (AtEndOfStream())
484 return createStringError(std::errc::illegal_byte_sequence,
485 "can't skip block: already at end of stream");
486 if (!canSkipToPos(SkipTo / 8))
487 return createStringError(std::errc::illegal_byte_sequence,
488 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo,
489 GetCurrentBitNo());
490
491 if (Error Res = JumpToBit(SkipTo))
492 return Res;
493
494 return Error::success();
495 }
496
497 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
498 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
499
500 bool ReadBlockEnd() {
501 if (BlockScope.empty()) return true;
502
503 // Block tail:
504 // [END_BLOCK, <align4bytes>]
505 SkipToFourByteBoundary();
506
507 popBlockScope();
508 return false;
509 }
510
511private:
512 void popBlockScope() {
513 CurCodeSize = BlockScope.back().PrevCodeSize;
514
515 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
516 BlockScope.pop_back();
517 }
518
519 //===--------------------------------------------------------------------===//
520 // Record Processing
521 //===--------------------------------------------------------------------===//
522
523public:
524 /// Return the abbreviation for the specified AbbrevId.
525 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
526 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
527 if (AbbrevNo >= CurAbbrevs.size())
528 report_fatal_error("Invalid abbrev number");
529 return CurAbbrevs[AbbrevNo].get();
530 }
531
532 /// Read the current record and discard it, returning the code for the record.
533 Expected<unsigned> skipRecord(unsigned AbbrevID);
534
535 Expected<unsigned> readRecord(unsigned AbbrevID,
536 SmallVectorImpl<uint64_t> &Vals,
537 StringRef *Blob = nullptr);
538
539 //===--------------------------------------------------------------------===//
540 // Abbrev Processing
541 //===--------------------------------------------------------------------===//
542 Error ReadAbbrevRecord();
543
544 /// Read and return a block info block from the bitstream. If an error was
545 /// encountered, return None.
546 ///
547 /// \param ReadBlockInfoNames Whether to read block/record name information in
548 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
549 Expected<Optional<BitstreamBlockInfo>>
550 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
551
552 /// Set the block info to be used by this BitstreamCursor to interpret
553 /// abbreviated records.
554 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
555};
556
557} // end llvm namespace
558
559#endif // LLVM_BITSTREAM_BITSTREAMREADER_H
←

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/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 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
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 [[noreturn]] void fatalUncheckedError() const;
261#endif
262
263 void assertIsChecked() {
264#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
265 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
266 fatalUncheckedError();
267#endif
268 }
269
270 ErrorInfoBase *getPtr() const {
271#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275#else
276 return Payload;
277#endif
278 }
279
280 void setPtr(ErrorInfoBase *EI) {
281#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
282 Payload = reinterpret_cast<ErrorInfoBase*>(
283 (reinterpret_cast<uintptr_t>(EI) &
284 ~static_cast<uintptr_t>(0x1)) |
285 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
286#else
287 Payload = EI;
288#endif
289 }
290
291 bool getChecked() const {
292#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
293 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
294#else
295 return true;
296#endif
297 }
298
299 void setChecked(bool V) {
300#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
301 Payload = reinterpret_cast<ErrorInfoBase*>(
302 (reinterpret_cast<uintptr_t>(Payload) &
303 ~static_cast<uintptr_t>(0x1)) |
304 (V ? 0 : 1));
305#endif
306 }
307
308 std::unique_ptr<ErrorInfoBase> takePayload() {
309 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
310 setPtr(nullptr);
311 setChecked(true);
312 return Tmp;
313 }
314
315 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
316 if (auto P = E.getPtr())
317 P->log(OS);
318 else
319 OS << "success";
320 return OS;
321 }
322
323 ErrorInfoBase *Payload = nullptr;
324};
325
326/// Subclass of Error for the sole purpose of identifying the success path in
327/// the type system. This allows to catch invalid conversion to Expected<T> at
328/// compile time.
329class ErrorSuccess final : public Error {};
330
331inline ErrorSuccess Error::success() { return ErrorSuccess(); }
332
333/// Make a Error instance representing failure using the given error info
334/// type.
335template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
336 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
337}
338
339/// Base class for user error types. Users should declare their error types
340/// like:
341///
342/// class MyError : public ErrorInfo<MyError> {
343/// ....
344/// };
345///
346/// This class provides an implementation of the ErrorInfoBase::kind
347/// method, which is used by the Error RTTI system.
348template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
349class ErrorInfo : public ParentErrT {
350public:
351 using ParentErrT::ParentErrT; // inherit constructors
352
353 static const void *classID() { return &ThisErrT::ID; }
354
355 const void *dynamicClassID() const override { return &ThisErrT::ID; }
356
357 bool isA(const void *const ClassID) const override {
358 return ClassID == classID() || ParentErrT::isA(ClassID);
359 }
360};
361
362/// Special ErrorInfo subclass representing a list of ErrorInfos.
363/// Instances of this class are constructed by joinError.
364class ErrorList final : public ErrorInfo<ErrorList> {
365 // handleErrors needs to be able to iterate the payload list of an
366 // ErrorList.
367 template <typename... HandlerTs>
368 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
369
370 // joinErrors is implemented in terms of join.
371 friend Error joinErrors(Error, Error);
372
373public:
374 void log(raw_ostream &OS) const override {
375 OS << "Multiple errors:\n";
376 for (auto &ErrPayload : Payloads) {
377 ErrPayload->log(OS);
378 OS << "\n";
379 }
380 }
381
382 std::error_code convertToErrorCode() const override;
383
384 // Used by ErrorInfo::classID.
385 static char ID;
386
387private:
388 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
389 std::unique_ptr<ErrorInfoBase> Payload2) {
390 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 391, __extension__ __PRETTY_FUNCTION__))
391 "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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 391, __extension__ __PRETTY_FUNCTION__));
392 Payloads.push_back(std::move(Payload1));
393 Payloads.push_back(std::move(Payload2));
394 }
395
396 static Error join(Error E1, Error E2) {
397 if (!E1)
398 return E2;
399 if (!E2)
400 return E1;
401 if (E1.isA<ErrorList>()) {
402 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
403 if (E2.isA<ErrorList>()) {
404 auto E2Payload = E2.takePayload();
405 auto &E2List = static_cast<ErrorList &>(*E2Payload);
406 for (auto &Payload : E2List.Payloads)
407 E1List.Payloads.push_back(std::move(Payload));
408 } else
409 E1List.Payloads.push_back(E2.takePayload());
410
411 return E1;
412 }
413 if (E2.isA<ErrorList>()) {
414 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
415 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
416 return E2;
417 }
418 return Error(std::unique_ptr<ErrorList>(
419 new ErrorList(E1.takePayload(), E2.takePayload())));
420 }
421
422 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
423};
424
425/// Concatenate errors. The resulting Error is unchecked, and contains the
426/// ErrorInfo(s), if any, contained in E1, followed by the
427/// ErrorInfo(s), if any, contained in E2.
428inline Error joinErrors(Error E1, Error E2) {
429 return ErrorList::join(std::move(E1), std::move(E2));
430}
431
432/// Tagged union holding either a T or a Error.
433///
434/// This class parallels ErrorOr, but replaces error_code with Error. Since
435/// Error cannot be copied, this class replaces getError() with
436/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
437/// error class type.
438///
439/// Example usage of 'Expected<T>' as a function return type:
440///
441/// @code{.cpp}
442/// Expected<int> myDivide(int A, int B) {
443/// if (B == 0) {
444/// // return an Error
445/// return createStringError(inconvertibleErrorCode(),
446/// "B must not be zero!");
447/// }
448/// // return an integer
449/// return A / B;
450/// }
451/// @endcode
452///
453/// Checking the results of to a function returning 'Expected<T>':
454/// @code{.cpp}
455/// if (auto E = Result.takeError()) {
456/// // We must consume the error. Typically one of:
457/// // - return the error to our caller
458/// // - toString(), when logging
459/// // - consumeError(), to silently swallow the error
460/// // - handleErrors(), to distinguish error types
461/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
462/// return;
463/// }
464/// // use the result
465/// outs() << "The answer is " << *Result << "\n";
466/// @endcode
467///
468/// For unit-testing a function returning an 'Expceted<T>', see the
469/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
470
471template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
472 template <class T1> friend class ExpectedAsOutParameter;
473 template <class OtherT> friend class Expected;
474
475 static constexpr bool isRef = std::is_reference<T>::value;
476
477 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
478
479 using error_type = std::unique_ptr<ErrorInfoBase>;
480
481public:
482 using storage_type = std::conditional_t<isRef, wrap, T>;
483 using value_type = T;
484
485private:
486 using reference = std::remove_reference_t<T> &;
487 using const_reference = const std::remove_reference_t<T> &;
488 using pointer = std::remove_reference_t<T> *;
489 using const_pointer = const std::remove_reference_t<T> *;
490
491public:
492 /// Create an Expected<T> error value from the given Error.
493 Expected(Error Err)
494 : HasError(true)
495#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
496 // Expected is unchecked upon construction in Debug builds.
497 , Unchecked(true)
498#endif
499 {
500 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 500, __extension__ __PRETTY_FUNCTION__));
501 new (getErrorStorage()) error_type(Err.takePayload());
502 }
503
504 /// Forbid to convert from Error::success() implicitly, this avoids having
505 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
506 /// but triggers the assertion above.
507 Expected(ErrorSuccess) = delete;
508
509 /// Create an Expected<T> success value from the given OtherT value, which
510 /// must be convertible to T.
511 template <typename OtherT>
512 Expected(OtherT &&Val,
513 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
514 : HasError(false)
515#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
516 // Expected is unchecked upon construction in Debug builds.
517 ,
518 Unchecked(true)
519#endif
520 {
521 new (getStorage()) storage_type(std::forward<OtherT>(Val));
522 }
523
524 /// Move construct an Expected<T> value.
525 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
526
527 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
528 /// must be convertible to T.
529 template <class OtherT>
530 Expected(
531 Expected<OtherT> &&Other,
532 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
533 moveConstruct(std::move(Other));
534 }
535
536 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
537 /// isn't convertible to T.
538 template <class OtherT>
539 explicit Expected(
540 Expected<OtherT> &&Other,
541 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
542 moveConstruct(std::move(Other));
543 }
544
545 /// Move-assign from another Expected<T>.
546 Expected &operator=(Expected &&Other) {
547 moveAssign(std::move(Other));
548 return *this;
549 }
550
551 /// Destroy an Expected<T>.
552 ~Expected() {
553 assertIsChecked();
554 if (!HasError)
555 getStorage()->~storage_type();
556 else
557 getErrorStorage()->~error_type();
558 }
559
560 /// Return false if there is an error.
561 explicit operator bool() {
562#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
563 Unchecked = HasError;
564#endif
565 return !HasError;
566 }
567
568 /// Returns a reference to the stored T value.
569 reference get() {
570 assertIsChecked();
571 return *getStorage();
572 }
573
574 /// Returns a const reference to the stored T value.
575 const_reference get() const {
576 assertIsChecked();
577 return const_cast<Expected<T> *>(this)->get();
578 }
579
580 /// Check that this Expected<T> is an error of type ErrT.
581 template <typename ErrT> bool errorIsA() const {
582 return HasError && (*getErrorStorage())->template isA<ErrT>();
583 }
584
585 /// Take ownership of the stored error.
586 /// After calling this the Expected<T> is in an indeterminate state that can
587 /// only be safely destructed. No further calls (beside the destructor) should
588 /// be made on the Expected<T> value.
589 Error takeError() {
590#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
591 Unchecked = false;
592#endif
593 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
594 }
595
596 /// Returns a pointer to the stored T value.
597 pointer operator->() {
598 assertIsChecked();
599 return toPointer(getStorage());
600 }
601
602 /// Returns a const pointer to the stored T value.
603 const_pointer operator->() const {
604 assertIsChecked();
605 return toPointer(getStorage());
606 }
607
608 /// Returns a reference to the stored T value.
609 reference operator*() {
610 assertIsChecked();
611 return *getStorage();
612 }
613
614 /// Returns a const reference to the stored T value.
615 const_reference operator*() const {
616 assertIsChecked();
617 return *getStorage();
618 }
619
620private:
621 template <class T1>
622 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
623 return &a == &b;
624 }
625
626 template <class T1, class T2>
627 static bool compareThisIfSameType(const T1 &, const T2 &) {
628 return false;
629 }
630
631 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
632 HasError = Other.HasError;
633#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
634 Unchecked = true;
635 Other.Unchecked = false;
636#endif
637
638 if (!HasError)
639 new (getStorage()) storage_type(std::move(*Other.getStorage()));
640 else
641 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
642 }
643
644 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
645 assertIsChecked();
646
647 if (compareThisIfSameType(*this, Other))
648 return;
649
650 this->~Expected();
651 new (this) Expected(std::move(Other));
652 }
653
654 pointer toPointer(pointer Val) { return Val; }
655
656 const_pointer toPointer(const_pointer Val) const { return Val; }
657
658 pointer toPointer(wrap *Val) { return &Val->get(); }
659
660 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
661
662 storage_type *getStorage() {
663 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 663, __extension__ __PRETTY_FUNCTION__));
664 return reinterpret_cast<storage_type *>(&TStorage);
665 }
666
667 const storage_type *getStorage() const {
668 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 668, __extension__ __PRETTY_FUNCTION__));
669 return reinterpret_cast<const storage_type *>(&TStorage);
670 }
671
672 error_type *getErrorStorage() {
673 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 673, __extension__ __PRETTY_FUNCTION__));
674 return reinterpret_cast<error_type *>(&ErrorStorage);
675 }
676
677 const error_type *getErrorStorage() const {
678 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 678, __extension__ __PRETTY_FUNCTION__));
679 return reinterpret_cast<const error_type *>(&ErrorStorage);
680 }
681
682 // Used by ExpectedAsOutParameter to reset the checked flag.
683 void setUnchecked() {
684#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
685 Unchecked = true;
686#endif
687 }
688
689#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
690 [[noreturn]] LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline)) void fatalUncheckedExpected() const {
691 dbgs() << "Expected<T> must be checked before access or destruction.\n";
692 if (HasError) {
693 dbgs() << "Unchecked Expected<T> contained error:\n";
694 (*getErrorStorage())->log(dbgs());
695 } else
696 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
697 "values in success mode must still be checked prior to being "
698 "destroyed).\n";
699 abort();
700 }
701#endif
702
703 void assertIsChecked() const {
704#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
705 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
706 fatalUncheckedExpected();
707#endif
708 }
709
710 union {
711 AlignedCharArrayUnion<storage_type> TStorage;
712 AlignedCharArrayUnion<error_type> ErrorStorage;
713 };
714 bool HasError : 1;
715#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
716 bool Unchecked : 1;
717#endif
718};
719
720/// Report a serious error, calling any installed error handler. See
721/// ErrorHandling.h.
722[[noreturn]] void report_fatal_error(Error Err, bool gen_crash_diag = true);
723
724/// Report a fatal error if Err is a failure value.
725///
726/// This function can be used to wrap calls to fallible functions ONLY when it
727/// is known that the Error will always be a success value. E.g.
728///
729/// @code{.cpp}
730/// // foo only attempts the fallible operation if DoFallibleOperation is
731/// // true. If DoFallibleOperation is false then foo always returns
732/// // Error::success().
733/// Error foo(bool DoFallibleOperation);
734///
735/// cantFail(foo(false));
736/// @endcode
737inline void cantFail(Error Err, const char *Msg = nullptr) {
738 if (Err) {
739 if (!Msg)
740 Msg = "Failure value returned from cantFail wrapped call";
741#ifndef NDEBUG
742 std::string Str;
743 raw_string_ostream OS(Str);
744 OS << Msg << "\n" << Err;
745 Msg = OS.str().c_str();
746#endif
747 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 747);
748 }
749}
750
751/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
752/// returns the contained value.
753///
754/// This function can be used to wrap calls to fallible functions ONLY when it
755/// is known that the Error will always be a success value. E.g.
756///
757/// @code{.cpp}
758/// // foo only attempts the fallible operation if DoFallibleOperation is
759/// // true. If DoFallibleOperation is false then foo always returns an int.
760/// Expected<int> foo(bool DoFallibleOperation);
761///
762/// int X = cantFail(foo(false));
763/// @endcode
764template <typename T>
765T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
766 if (ValOrErr)
767 return std::move(*ValOrErr);
768 else {
769 if (!Msg)
770 Msg = "Failure value returned from cantFail wrapped call";
771#ifndef NDEBUG
772 std::string Str;
773 raw_string_ostream OS(Str);
774 auto E = ValOrErr.takeError();
775 OS << Msg << "\n" << E;
776 Msg = OS.str().c_str();
777#endif
778 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 778);
779 }
780}
781
782/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
783/// returns the contained reference.
784///
785/// This function can be used to wrap calls to fallible functions ONLY when it
786/// is known that the Error will always be a success value. E.g.
787///
788/// @code{.cpp}
789/// // foo only attempts the fallible operation if DoFallibleOperation is
790/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
791/// Expected<Bar&> foo(bool DoFallibleOperation);
792///
793/// Bar &X = cantFail(foo(false));
794/// @endcode
795template <typename T>
796T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
797 if (ValOrErr)
798 return *ValOrErr;
799 else {
800 if (!Msg)
801 Msg = "Failure value returned from cantFail wrapped call";
802#ifndef NDEBUG
803 std::string Str;
804 raw_string_ostream OS(Str);
805 auto E = ValOrErr.takeError();
806 OS << Msg << "\n" << E;
807 Msg = OS.str().c_str();
808#endif
809 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 809);
810 }
811}
812
813/// Helper for testing applicability of, and applying, handlers for
814/// ErrorInfo types.
815template <typename HandlerT>
816class ErrorHandlerTraits
817 : public ErrorHandlerTraits<decltype(
818 &std::remove_reference<HandlerT>::type::operator())> {};
819
820// Specialization functions of the form 'Error (const ErrT&)'.
821template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
822public:
823 static bool appliesTo(const ErrorInfoBase &E) {
824 return E.template isA<ErrT>();
825 }
826
827 template <typename HandlerT>
828 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
829 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 829, __extension__ __PRETTY_FUNCTION__));
830 return H(static_cast<ErrT &>(*E));
831 }
832};
833
834// Specialization functions of the form 'void (const ErrT&)'.
835template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
836public:
837 static bool appliesTo(const ErrorInfoBase &E) {
838 return E.template isA<ErrT>();
839 }
840
841 template <typename HandlerT>
842 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
843 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 843, __extension__ __PRETTY_FUNCTION__));
844 H(static_cast<ErrT &>(*E));
845 return Error::success();
846 }
847};
848
849/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
850template <typename ErrT>
851class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
852public:
853 static bool appliesTo(const ErrorInfoBase &E) {
854 return E.template isA<ErrT>();
855 }
856
857 template <typename HandlerT>
858 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
859 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 859, __extension__ __PRETTY_FUNCTION__));
860 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
861 return H(std::move(SubE));
862 }
863};
864
865/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
866template <typename ErrT>
867class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
868public:
869 static bool appliesTo(const ErrorInfoBase &E) {
870 return E.template isA<ErrT>();
871 }
872
873 template <typename HandlerT>
874 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
875 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-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 875, __extension__ __PRETTY_FUNCTION__));
876 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
877 H(std::move(SubE));
878 return Error::success();
879 }
880};
881
882// Specialization for member functions of the form 'RetT (const ErrT&)'.
883template <typename C, typename RetT, typename ErrT>
884class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
885 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
886
887// Specialization for member functions of the form 'RetT (const ErrT&) const'.
888template <typename C, typename RetT, typename ErrT>
889class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
890 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
891
892// Specialization for member functions of the form 'RetT (const ErrT&)'.
893template <typename C, typename RetT, typename ErrT>
894class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
895 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
896
897// Specialization for member functions of the form 'RetT (const ErrT&) const'.
898template <typename C, typename RetT, typename ErrT>
899class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
900 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
901
902/// Specialization for member functions of the form
903/// 'RetT (std::unique_ptr<ErrT>)'.
904template <typename C, typename RetT, typename ErrT>
905class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
906 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
907
908/// Specialization for member functions of the form
909/// 'RetT (std::unique_ptr<ErrT>) const'.
910template <typename C, typename RetT, typename ErrT>
911class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
912 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
913
914inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
915 return Error(std::move(Payload));
916}
917
918template <typename HandlerT, typename... HandlerTs>
919Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
920 HandlerT &&Handler, HandlerTs &&... Handlers) {
921 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
922 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
923 std::move(Payload));
924 return handleErrorImpl(std::move(Payload),
925 std::forward<HandlerTs>(Handlers)...);
926}
927
928/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
929/// unhandled errors (or Errors returned by handlers) are re-concatenated and
930/// returned.
931/// Because this function returns an error, its result must also be checked
932/// or returned. If you intend to handle all errors use handleAllErrors
933/// (which returns void, and will abort() on unhandled errors) instead.
934template <typename... HandlerTs>
935Error handleErrors(Error E, HandlerTs &&... Hs) {
936 if (!E)
937 return Error::success();
938
939 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
940
941 if (Payload->isA<ErrorList>()) {
942 ErrorList &List = static_cast<ErrorList &>(*Payload);
943 Error R;
944 for (auto &P : List.Payloads)
945 R = ErrorList::join(
946 std::move(R),
947 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
948 return R;
949 }
950
951 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
952}
953
954/// Behaves the same as handleErrors, except that by contract all errors
955/// *must* be handled by the given handlers (i.e. there must be no remaining
956/// errors after running the handlers, or llvm_unreachable is called).
957template <typename... HandlerTs>
958void handleAllErrors(Error E, HandlerTs &&... Handlers) {
959 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
960}
961
962/// Check that E is a non-error, then drop it.
963/// If E is an error, llvm_unreachable will be called.
964inline void handleAllErrors(Error E) {
965 cantFail(std::move(E));
966}
967
968/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
969///
970/// If the incoming value is a success value it is returned unmodified. If it
971/// is a failure value then it the contained error is passed to handleErrors.
972/// If handleErrors is able to handle the error then the RecoveryPath functor
973/// is called to supply the final result. If handleErrors is not able to
974/// handle all errors then the unhandled errors are returned.
975///
976/// This utility enables the follow pattern:
977///
978/// @code{.cpp}
979/// enum FooStrategy { Aggressive, Conservative };
980/// Expected<Foo> foo(FooStrategy S);
981///
982/// auto ResultOrErr =
983/// handleExpected(
984/// foo(Aggressive),
985/// []() { return foo(Conservative); },
986/// [](AggressiveStrategyError&) {
987/// // Implicitly conusme this - we'll recover by using a conservative
988/// // strategy.
989/// });
990///
991/// @endcode
992template <typename T, typename RecoveryFtor, typename... HandlerTs>
993Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
994 HandlerTs &&... Handlers) {
995 if (ValOrErr)
996 return ValOrErr;
997
998 if (auto Err = handleErrors(ValOrErr.takeError(),
999 std::forward<HandlerTs>(Handlers)...))
1000 return std::move(Err);
1001
1002 return RecoveryPath();
1003}
1004
1005/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1006/// will be printed before the first one is logged. A newline will be printed
1007/// after each error.
1008///
1009/// This function is compatible with the helpers from Support/WithColor.h. You
1010/// can pass any of them as the OS. Please consider using them instead of
1011/// including 'error: ' in the ErrorBanner.
1012///
1013/// This is useful in the base level of your program to allow clean termination
1014/// (allowing clean deallocation of resources, etc.), while reporting error
1015/// information to the user.
1016void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1017
1018/// Write all error messages (if any) in E to a string. The newline character
1019/// is used to separate error messages.
1020inline std::string toString(Error E) {
1021 SmallVector<std::string, 2> Errors;
1022 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1023 Errors.push_back(EI.message());
1024 });
1025 return join(Errors.begin(), Errors.end(), "\n");
1026}
1027
1028/// Consume a Error without doing anything. This method should be used
1029/// only where an error can be considered a reasonable and expected return
1030/// value.
1031///
1032/// Uses of this method are potentially indicative of design problems: If it's
1033/// legitimate to do nothing while processing an "error", the error-producer
1034/// might be more clearly refactored to return an Optional<T>.
1035inline void consumeError(Error Err) {
1036 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1037}
1038
1039/// Convert an Expected to an Optional without doing anything. This method
1040/// should be used only where an error can be considered a reasonable and
1041/// expected return value.
1042///
1043/// Uses of this method are potentially indicative of problems: perhaps the
1044/// error should be propagated further, or the error-producer should just
1045/// return an Optional in the first place.
1046template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1047 if (E)
1048 return std::move(*E);
1049 consumeError(E.takeError());
1050 return None;
1051}
1052
1053/// Helper for converting an Error to a bool.
1054///
1055/// This method returns true if Err is in an error state, or false if it is
1056/// in a success state. Puts Err in a checked state in both cases (unlike
1057/// Error::operator bool(), which only does this for success states).
1058inline bool errorToBool(Error Err) {
1059 bool IsError = static_cast<bool>(Err);
1060 if (IsError)
1061 consumeError(std::move(Err));
1062 return IsError;
1063}
1064
1065/// Helper for Errors used as out-parameters.
1066///
1067/// This helper is for use with the Error-as-out-parameter idiom, where an error
1068/// is passed to a function or method by reference, rather than being returned.
1069/// In such cases it is helpful to set the checked bit on entry to the function
1070/// so that the error can be written to (unchecked Errors abort on assignment)
1071/// and clear the checked bit on exit so that clients cannot accidentally forget
1072/// to check the result. This helper performs these actions automatically using
1073/// RAII:
1074///
1075/// @code{.cpp}
1076/// Result foo(Error &Err) {
1077/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1078/// // <body of foo>
1079/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1080/// }
1081/// @endcode
1082///
1083/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1084/// used with optional Errors (Error pointers that are allowed to be null). If
1085/// ErrorAsOutParameter took an Error reference, an instance would have to be
1086/// created inside every condition that verified that Error was non-null. By
1087/// taking an Error pointer we can just create one instance at the top of the
1088/// function.
1089class ErrorAsOutParameter {
1090public:
1091 ErrorAsOutParameter(Error *Err) : Err(Err) {
1092 // Raise the checked bit if Err is success.
1093 if (Err)
1094 (void)!!*Err;
1095 }
1096
1097 ~ErrorAsOutParameter() {
1098 // Clear the checked bit.
1099 if (Err && !*Err)
1100 *Err = Error::success();
1101 }
1102
1103private:
1104 Error *Err;
1105};
1106
1107/// Helper for Expected<T>s used as out-parameters.
1108///
1109/// See ErrorAsOutParameter.
1110template <typename T>
1111class ExpectedAsOutParameter {
1112public:
1113 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1114 : ValOrErr(ValOrErr) {
1115 if (ValOrErr)
1116 (void)!!*ValOrErr;
1117 }
1118
1119 ~ExpectedAsOutParameter() {
1120 if (ValOrErr)
1121 ValOrErr->setUnchecked();
1122 }
1123
1124private:
1125 Expected<T> *ValOrErr;
1126};
1127
1128/// This class wraps a std::error_code in a Error.
1129///
1130/// This is useful if you're writing an interface that returns a Error
1131/// (or Expected) and you want to call code that still returns
1132/// std::error_codes.
1133class ECError : public ErrorInfo<ECError> {
1134 friend Error errorCodeToError(std::error_code);
1135
1136 virtual void anchor() override;
1137
1138public:
1139 void setErrorCode(std::error_code EC) { this->EC = EC; }
1140 std::error_code convertToErrorCode() const override { return EC; }
1141 void log(raw_ostream &OS) const override { OS << EC.message(); }
1142
1143 // Used by ErrorInfo::classID.
1144 static char ID;
1145
1146protected:
1147 ECError() = default;
1148 ECError(std::error_code EC) : EC(EC) {}
1149
1150 std::error_code EC;
1151};
1152
1153/// The value returned by this function can be returned from convertToErrorCode
1154/// for Error values where no sensible translation to std::error_code exists.
1155/// It should only be used in this situation, and should never be used where a
1156/// sensible conversion to std::error_code is available, as attempts to convert
1157/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1158///error to try to convert such a value).
1159std::error_code inconvertibleErrorCode();
1160
1161/// Helper for converting an std::error_code to a Error.
1162Error errorCodeToError(std::error_code EC);
1163
1164/// Helper for converting an ECError to a std::error_code.
1165///
1166/// This method requires that Err be Error() or an ECError, otherwise it
1167/// will trigger a call to abort().
1168std::error_code errorToErrorCode(Error Err);
1169
1170/// Convert an ErrorOr<T> to an Expected<T>.
1171template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1172 if (auto EC = EO.getError())
1173 return errorCodeToError(EC);
1174 return std::move(*EO);
1175}
1176
1177/// Convert an Expected<T> to an ErrorOr<T>.
1178template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1179 if (auto Err = E.takeError())
1180 return errorToErrorCode(std::move(Err));
1181 return std::move(*E);
1182}
1183
1184/// This class wraps a string in an Error.
1185///
1186/// StringError is useful in cases where the client is not expected to be able
1187/// to consume the specific error message programmatically (for example, if the
1188/// error message is to be presented to the user).
1189///
1190/// StringError can also be used when additional information is to be printed
1191/// along with a error_code message. Depending on the constructor called, this
1192/// class can either display:
1193/// 1. the error_code message (ECError behavior)
1194/// 2. a string
1195/// 3. the error_code message and a string
1196///
1197/// These behaviors are useful when subtyping is required; for example, when a
1198/// specific library needs an explicit error type. In the example below,
1199/// PDBError is derived from StringError:
1200///
1201/// @code{.cpp}
1202/// Expected<int> foo() {
1203/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1204/// "Additional information");
1205/// }
1206/// @endcode
1207///
1208class StringError : public ErrorInfo<StringError> {
1209public:
1210 static char ID;
1211
1212 // Prints EC + S and converts to EC
1213 StringError(std::error_code EC, const Twine &S = Twine());
1214
1215 // Prints S and converts to EC
1216 StringError(const Twine &S, std::error_code EC);
1217
1218 void log(raw_ostream &OS) const override;
1219 std::error_code convertToErrorCode() const override;
1220
1221 const std::string &getMessage() const { return Msg; }
1222
1223private:
1224 std::string Msg;
1225 std::error_code EC;
1226 const bool PrintMsgOnly = false;
1227};
1228
1229/// Create formatted StringError object.
1230template <typename... Ts>
1231inline Error createStringError(std::error_code EC, char const *Fmt,
1232 const Ts &... Vals) {
1233 std::string Buffer;
1234 raw_string_ostream Stream(Buffer);
1235 Stream << format(Fmt, Vals...);
1236 return make_error<StringError>(Stream.str(), EC);
1237}
1238
1239Error createStringError(std::error_code EC, char const *Msg);
1240
1241inline Error createStringError(std::error_code EC, const Twine &S) {
1242 return createStringError(EC, S.str().c_str());
1243}
1244
1245template <typename... Ts>
1246inline Error createStringError(std::errc EC, char const *Fmt,
1247 const Ts &... Vals) {
1248 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1249}
1250
1251/// This class wraps a filename and another Error.
1252///
1253/// In some cases, an error needs to live along a 'source' name, in order to
1254/// show more detailed information to the user.
1255class FileError final : public ErrorInfo<FileError> {
1256
1257 friend Error createFileError(const Twine &, Error);
1258 friend Error createFileError(const Twine &, size_t, Error);
1259
1260public:
1261 void log(raw_ostream &OS) const override {
1262 assert(Err && !FileName.empty() && "Trying to log after takeError().")(static_cast <bool> (Err && !FileName.empty() &&
"Trying to log after takeError().") ? void (0) : __assert_fail
("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1262, __extension__ __PRETTY_FUNCTION__));
1263 OS << "'" << FileName << "': ";
1264 if (Line.hasValue())
1265 OS << "line " << Line.getValue() << ": ";
1266 Err->log(OS);
1267 }
1268
1269 StringRef getFileName() { return FileName; }
1270
1271 Error takeError() { return Error(std::move(Err)); }
1272
1273 std::error_code convertToErrorCode() const override;
1274
1275 // Used by ErrorInfo::classID.
1276 static char ID;
1277
1278private:
1279 FileError(const Twine &F, Optional<size_t> LineNum,
1280 std::unique_ptr<ErrorInfoBase> E) {
1281 assert(E && "Cannot create FileError from Error success value.")(static_cast <bool> (E && "Cannot create FileError from Error success value."
) ? void (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1281, __extension__ __PRETTY_FUNCTION__));
1282 assert(!F.isTriviallyEmpty() &&(static_cast <bool> (!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? void (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1283, __extension__ __PRETTY_FUNCTION__))
1283 "The file name provided to FileError must not be empty.")(static_cast <bool> (!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? void (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1283, __extension__ __PRETTY_FUNCTION__));
1284 FileName = F.str();
1285 Err = std::move(E);
1286 Line = std::move(LineNum);
1287 }
1288
1289 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1290 std::unique_ptr<ErrorInfoBase> Payload;
1291 handleAllErrors(std::move(E),
1292 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1293 Payload = std::move(EIB);
1294 return Error::success();
1295 });
1296 return Error(
1297 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1298 }
1299
1300 std::string FileName;
1301 Optional<size_t> Line;
1302 std::unique_ptr<ErrorInfoBase> Err;
1303};
1304
1305/// Concatenate a source file path and/or name with an Error. The resulting
1306/// Error is unchecked.
1307inline Error createFileError(const Twine &F, Error E) {
1308 return FileError::build(F, Optional<size_t>(), std::move(E));
1309}
1310
1311/// Concatenate a source file path and/or name with line number and an Error.
1312/// The resulting Error is unchecked.
1313inline Error createFileError(const Twine &F, size_t Line, Error E) {
1314 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1315}
1316
1317/// Concatenate a source file path and/or name with a std::error_code
1318/// to form an Error object.
1319inline Error createFileError(const Twine &F, std::error_code EC) {
1320 return createFileError(F, errorCodeToError(EC));
1321}
1322
1323/// Concatenate a source file path and/or name with line number and
1324/// std::error_code to form an Error object.
1325inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1326 return createFileError(F, Line, errorCodeToError(EC));
1327}
1328
1329Error createFileError(const Twine &F, ErrorSuccess) = delete;
1330
1331/// Helper for check-and-exit error handling.
1332///
1333/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1334///
1335class ExitOnError {
1336public:
1337 /// Create an error on exit helper.
1338 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1339 : Banner(std::move(Banner)),
1340 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1341
1342 /// Set the banner string for any errors caught by operator().
1343 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1344
1345 /// Set the exit-code mapper function.
1346 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1347 this->GetExitCode = std::move(GetExitCode);
1348 }
1349
1350 /// Check Err. If it's in a failure state log the error(s) and exit.
1351 void operator()(Error Err) const { checkError(std::move(Err)); }
1352
1353 /// Check E. If it's in a success state then return the contained value. If
1354 /// it's in a failure state log the error(s) and exit.
1355 template <typename T> T operator()(Expected<T> &&E) const {
1356 checkError(E.takeError());
1357 return std::move(*E);
1358 }
1359
1360 /// Check E. If it's in a success state then return the contained reference. If
1361 /// it's in a failure state log the error(s) and exit.
1362 template <typename T> T& operator()(Expected<T&> &&E) const {
1363 checkError(E.takeError());
1364 return *E;
1365 }
1366
1367private:
1368 void checkError(Error Err) const {
1369 if (Err) {
1370 int ExitCode = GetExitCode(Err);
1371 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1372 exit(ExitCode);
1373 }
1374 }
1375
1376 std::string Banner;
1377 std::function<int(const Error &)> GetExitCode;
1378};
1379
1380/// Conversion from Error to LLVMErrorRef for C error bindings.
1381inline LLVMErrorRef wrap(Error Err) {
1382 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1383}
1384
1385/// Conversion from LLVMErrorRef to Error for C error bindings.
1386inline Error unwrap(LLVMErrorRef ErrRef) {
1387 return Error(std::unique_ptr<ErrorInfoBase>(
1388 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1389}
1390
1391} // end namespace llvm
1392
1393#endif // LLVM_SUPPORT_ERROR_H