Bug Summary

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

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name 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 -mthread-model posix -mframe-pointer=none -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/lib/Remarks -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-05-225554-32688-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/lib/Remarks/BitstreamRemarkParser.cpp

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/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/Remarks/BitstreamRemarkContainer.h"
17#include "llvm/Support/MemoryBuffer.h"
18#include "llvm/Support/Path.h"
19
20using namespace llvm;
21using namespace llvm::remarks;
22
23static Error unknownRecord(const char *BlockName, unsigned RecordID) {
24 return createStringError(
25 std::make_error_code(std::errc::illegal_byte_sequence),
26 "Error while parsing %s: unknown record entry (%lu).", BlockName,
27 RecordID);
28}
29
30static Error malformedRecord(const char *BlockName, const char *RecordName) {
31 return createStringError(
32 std::make_error_code(std::errc::illegal_byte_sequence),
33 "Error while parsing %s: malformed record entry (%s).", BlockName,
34 RecordName);
35}
36
37BitstreamMetaParserHelper::BitstreamMetaParserHelper(
38 BitstreamCursor &Stream, BitstreamBlockInfo &BlockInfo)
39 : Stream(Stream), BlockInfo(BlockInfo) {}
40
41/// Parse a record and fill in the fields in the parser.
42static Error parseRecord(BitstreamMetaParserHelper &Parser, unsigned Code) {
43 BitstreamCursor &Stream = Parser.Stream;
44 // Note: 2 is used here because it's the max number of fields we have per
45 // record.
46 SmallVector<uint64_t, 2> Record;
47 StringRef Blob;
48 Expected<unsigned> RecordID = Stream.readRecord(Code, Record, &Blob);
49 if (!RecordID)
50 return RecordID.takeError();
51
52 switch (*RecordID) {
53 case RECORD_META_CONTAINER_INFO: {
54 if (Record.size() != 2)
55 return malformedRecord("BLOCK_META", "RECORD_META_CONTAINER_INFO");
56 Parser.ContainerVersion = Record[0];
57 Parser.ContainerType = Record[1];
58 break;
59 }
60 case RECORD_META_REMARK_VERSION: {
61 if (Record.size() != 1)
62 return malformedRecord("BLOCK_META", "RECORD_META_REMARK_VERSION");
63 Parser.RemarkVersion = Record[0];
64 break;
65 }
66 case RECORD_META_STRTAB: {
67 if (Record.size() != 0)
68 return malformedRecord("BLOCK_META", "RECORD_META_STRTAB");
69 Parser.StrTabBuf = Blob;
70 break;
71 }
72 case RECORD_META_EXTERNAL_FILE: {
73 if (Record.size() != 0)
74 return malformedRecord("BLOCK_META", "RECORD_META_EXTERNAL_FILE");
75 Parser.ExternalFilePath = Blob;
76 break;
77 }
78 default:
79 return unknownRecord("BLOCK_META", *RecordID);
80 }
81 return Error::success();
82}
83
84BitstreamRemarkParserHelper::BitstreamRemarkParserHelper(
85 BitstreamCursor &Stream)
86 : Stream(Stream) {}
87
88/// Parse a record and fill in the fields in the parser.
89static Error parseRecord(BitstreamRemarkParserHelper &Parser, unsigned Code) {
90 BitstreamCursor &Stream = Parser.Stream;
91 // Note: 5 is used here because it's the max number of fields we have per
92 // record.
93 SmallVector<uint64_t, 5> Record;
94 StringRef Blob;
95 Expected<unsigned> RecordID = Stream.readRecord(Code, Record, &Blob);
96 if (!RecordID)
97 return RecordID.takeError();
98
99 switch (*RecordID) {
100 case RECORD_REMARK_HEADER: {
101 if (Record.size() != 4)
102 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_HEADER");
103 Parser.Type = Record[0];
104 Parser.RemarkNameIdx = Record[1];
105 Parser.PassNameIdx = Record[2];
106 Parser.FunctionNameIdx = Record[3];
107 break;
108 }
109 case RECORD_REMARK_DEBUG_LOC: {
110 if (Record.size() != 3)
111 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_DEBUG_LOC");
112 Parser.SourceFileNameIdx = Record[0];
113 Parser.SourceLine = Record[1];
114 Parser.SourceColumn = Record[2];
115 break;
116 }
117 case RECORD_REMARK_HOTNESS: {
118 if (Record.size() != 1)
119 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_HOTNESS");
120 Parser.Hotness = Record[0];
121 break;
122 }
123 case RECORD_REMARK_ARG_WITH_DEBUGLOC: {
124 if (Record.size() != 5)
125 return malformedRecord("BLOCK_REMARK", "RECORD_REMARK_ARG_WITH_DEBUGLOC");
126 // Create a temporary argument. Use that as a valid memory location for this
127 // argument entry.
128 Parser.TmpArgs.emplace_back();
129 Parser.TmpArgs.back().KeyIdx = Record[0];
130 Parser.TmpArgs.back().ValueIdx = Record[1];
131 Parser.TmpArgs.back().SourceFileNameIdx = Record[2];
132 Parser.TmpArgs.back().SourceLine = Record[3];
133 Parser.TmpArgs.back().SourceColumn = Record[4];
134 Parser.Args =
135 ArrayRef<BitstreamRemarkParserHelper::Argument>(Parser.TmpArgs);
136 break;
137 }
138 case RECORD_REMARK_ARG_WITHOUT_DEBUGLOC: {
139 if (Record.size() != 2)
140 return malformedRecord("BLOCK_REMARK",
141 "RECORD_REMARK_ARG_WITHOUT_DEBUGLOC");
142 // Create a temporary argument. Use that as a valid memory location for this
143 // argument entry.
144 Parser.TmpArgs.emplace_back();
145 Parser.TmpArgs.back().KeyIdx = Record[0];
146 Parser.TmpArgs.back().ValueIdx = Record[1];
147 Parser.Args =
148 ArrayRef<BitstreamRemarkParserHelper::Argument>(Parser.TmpArgs);
149 break;
150 }
151 default:
152 return unknownRecord("BLOCK_REMARK", *RecordID);
153 }
154 return Error::success();
155}
156
157template <typename T>
158static Error parseBlock(T &ParserHelper, unsigned BlockID,
159 const char *BlockName) {
160 BitstreamCursor &Stream = ParserHelper.Stream;
161 Expected<BitstreamEntry> Next = Stream.advance();
162 if (!Next)
163 return Next.takeError();
164 if (Next->Kind != BitstreamEntry::SubBlock || Next->ID != BlockID)
165 return createStringError(
166 std::make_error_code(std::errc::illegal_byte_sequence),
167 "Error while parsing %s: expecting [ENTER_SUBBLOCK, %s, ...].",
168 BlockName, BlockName);
169 if (Stream.EnterSubBlock(BlockID))
170 return createStringError(
171 std::make_error_code(std::errc::illegal_byte_sequence),
172 "Error while entering %s.", BlockName);
173
174 // Stop when there is nothing to read anymore or when we encounter an
175 // END_BLOCK.
176 while (!Stream.AtEndOfStream()) {
177 Next = Stream.advance();
178 if (!Next)
179 return Next.takeError();
180 switch (Next->Kind) {
181 case BitstreamEntry::EndBlock:
182 return Error::success();
183 case BitstreamEntry::Error:
184 case BitstreamEntry::SubBlock:
185 return createStringError(
186 std::make_error_code(std::errc::illegal_byte_sequence),
187 "Error while parsing %s: expecting records.", BlockName);
188 case BitstreamEntry::Record:
189 if (Error E = parseRecord(ParserHelper, Next->ID))
190 return E;
191 continue;
192 }
193 }
194 // If we're here, it means we didn't get an END_BLOCK yet, but we're at the
195 // end of the stream. In this case, error.
196 return createStringError(
197 std::make_error_code(std::errc::illegal_byte_sequence),
198 "Error while parsing %s: unterminated block.", BlockName);
199}
200
201Error BitstreamMetaParserHelper::parse() {
202 return parseBlock(*this, META_BLOCK_ID, "META_BLOCK");
203}
204
205Error BitstreamRemarkParserHelper::parse() {
206 return parseBlock(*this, REMARK_BLOCK_ID, "REMARK_BLOCK");
207}
208
209BitstreamParserHelper::BitstreamParserHelper(StringRef Buffer)
210 : Stream(Buffer) {}
211
212Expected<std::array<char, 4>> BitstreamParserHelper::parseMagic() {
213 std::array<char, 4> Result;
214 for (unsigned i = 0; i < 4; ++i)
2
Loop condition is true. Entering loop body
215 if (Expected<unsigned> R = Stream.Read(8))
3
Calling 'SimpleBitstreamCursor::Read'
216 Result[i] = *R;
217 else
218 return R.takeError();
219 return Result;
220}
221
222Error BitstreamParserHelper::parseBlockInfoBlock() {
223 Expected<BitstreamEntry> Next = Stream.advance();
224 if (!Next)
225 return Next.takeError();
226 if (Next->Kind != BitstreamEntry::SubBlock ||
227 Next->ID != llvm::bitc::BLOCKINFO_BLOCK_ID)
228 return createStringError(
229 std::make_error_code(std::errc::illegal_byte_sequence),
230 "Error while parsing BLOCKINFO_BLOCK: expecting [ENTER_SUBBLOCK, "
231 "BLOCKINFO_BLOCK, ...].");
232
233 Expected<Optional<BitstreamBlockInfo>> MaybeBlockInfo =
234 Stream.ReadBlockInfoBlock();
235 if (!MaybeBlockInfo)
236 return MaybeBlockInfo.takeError();
237
238 if (!*MaybeBlockInfo)
239 return createStringError(
240 std::make_error_code(std::errc::illegal_byte_sequence),
241 "Error while parsing BLOCKINFO_BLOCK.");
242
243 BlockInfo = **MaybeBlockInfo;
244
245 Stream.setBlockInfo(&BlockInfo);
246 return Error::success();
247}
248
249static Expected<bool> isBlock(BitstreamCursor &Stream, unsigned BlockID) {
250 bool Result = false;
251 uint64_t PreviousBitNo = Stream.GetCurrentBitNo();
252 Expected<BitstreamEntry> Next = Stream.advance();
253 if (!Next)
254 return Next.takeError();
255 switch (Next->Kind) {
256 case BitstreamEntry::SubBlock:
257 // Check for the block id.
258 Result = Next->ID == BlockID;
259 break;
260 case BitstreamEntry::Error:
261 return createStringError(
262 std::make_error_code(std::errc::illegal_byte_sequence),
263 "Unexpected error while parsing bitstream.");
264 default:
265 Result = false;
266 break;
267 }
268 if (Error E = Stream.JumpToBit(PreviousBitNo))
269 return std::move(E);
270 return Result;
271}
272
273Expected<bool> BitstreamParserHelper::isMetaBlock() {
274 return isBlock(Stream, META_BLOCK_ID);
275}
276
277Expected<bool> BitstreamParserHelper::isRemarkBlock() {
278 return isBlock(Stream, META_BLOCK_ID);
279}
280
281static Error validateMagicNumber(StringRef MagicNumber) {
282 if (MagicNumber != remarks::ContainerMagic)
283 return createStringError(std::make_error_code(std::errc::invalid_argument),
284 "Unknown magic number: expecting %s, got %.4s.",
285 remarks::ContainerMagic.data(), MagicNumber.data());
286 return Error::success();
287}
288
289static Error advanceToMetaBlock(BitstreamParserHelper &Helper) {
290 Expected<std::array<char, 4>> MagicNumber = Helper.parseMagic();
291 if (!MagicNumber)
292 return MagicNumber.takeError();
293 if (Error E = validateMagicNumber(
294 StringRef(MagicNumber->data(), MagicNumber->size())))
295 return E;
296 if (Error E = Helper.parseBlockInfoBlock())
297 return E;
298 Expected<bool> isMetaBlock = Helper.isMetaBlock();
299 if (!isMetaBlock)
300 return isMetaBlock.takeError();
301 if (!*isMetaBlock)
302 return createStringError(
303 std::make_error_code(std::errc::illegal_byte_sequence),
304 "Expecting META_BLOCK after the BLOCKINFO_BLOCK.");
305 return Error::success();
306}
307
308Expected<std::unique_ptr<BitstreamRemarkParser>>
309remarks::createBitstreamParserFromMeta(
310 StringRef Buf, Optional<ParsedStringTable> StrTab,
311 Optional<StringRef> ExternalFilePrependPath) {
312 BitstreamParserHelper Helper(Buf);
313 Expected<std::array<char, 4>> MagicNumber = Helper.parseMagic();
1
Calling 'BitstreamParserHelper::parseMagic'
314 if (!MagicNumber)
315 return MagicNumber.takeError();
316
317 if (Error E = validateMagicNumber(
318 StringRef(MagicNumber->data(), MagicNumber->size())))
319 return std::move(E);
320
321 auto Parser =
322 StrTab ? std::make_unique<BitstreamRemarkParser>(Buf, std::move(*StrTab))
323 : std::make_unique<BitstreamRemarkParser>(Buf);
324
325 if (ExternalFilePrependPath)
326 Parser->ExternalFilePrependPath = *ExternalFilePrependPath;
327
328 return std::move(Parser);
329}
330
331Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::next() {
332 if (ParserHelper.atEndOfStream())
333 return make_error<EndOfFileError>();
334
335 if (!ReadyToParseRemarks) {
336 if (Error E = parseMeta())
337 return std::move(E);
338 ReadyToParseRemarks = true;
339 }
340
341 return parseRemark();
342}
343
344Error BitstreamRemarkParser::parseMeta() {
345 // Advance and to the meta block.
346 if (Error E = advanceToMetaBlock(ParserHelper))
347 return E;
348
349 BitstreamMetaParserHelper MetaHelper(ParserHelper.Stream,
350 ParserHelper.BlockInfo);
351 if (Error E = MetaHelper.parse())
352 return E;
353
354 if (Error E = processCommonMeta(MetaHelper))
355 return E;
356
357 switch (ContainerType) {
358 case BitstreamRemarkContainerType::Standalone:
359 return processStandaloneMeta(MetaHelper);
360 case BitstreamRemarkContainerType::SeparateRemarksFile:
361 return processSeparateRemarksFileMeta(MetaHelper);
362 case BitstreamRemarkContainerType::SeparateRemarksMeta:
363 return processSeparateRemarksMetaMeta(MetaHelper);
364 }
365 llvm_unreachable("Unknown BitstreamRemarkContainerType enum")::llvm::llvm_unreachable_internal("Unknown BitstreamRemarkContainerType enum"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/lib/Remarks/BitstreamRemarkParser.cpp"
, 365)
;
366}
367
368Error BitstreamRemarkParser::processCommonMeta(
369 BitstreamMetaParserHelper &Helper) {
370 if (Optional<uint64_t> Version = Helper.ContainerVersion)
371 ContainerVersion = *Version;
372 else
373 return createStringError(
374 std::make_error_code(std::errc::illegal_byte_sequence),
375 "Error while parsing BLOCK_META: missing container version.");
376
377 if (Optional<uint8_t> Type = Helper.ContainerType) {
378 // Always >= BitstreamRemarkContainerType::First since it's unsigned.
379 if (*Type > static_cast<uint8_t>(BitstreamRemarkContainerType::Last))
380 return createStringError(
381 std::make_error_code(std::errc::illegal_byte_sequence),
382 "Error while parsing BLOCK_META: invalid container type.");
383
384 ContainerType = static_cast<BitstreamRemarkContainerType>(*Type);
385 } else
386 return createStringError(
387 std::make_error_code(std::errc::illegal_byte_sequence),
388 "Error while parsing BLOCK_META: missing container type.");
389
390 return Error::success();
391}
392
393static Error processStrTab(BitstreamRemarkParser &P,
394 Optional<StringRef> StrTabBuf) {
395 if (!StrTabBuf)
396 return createStringError(
397 std::make_error_code(std::errc::illegal_byte_sequence),
398 "Error while parsing BLOCK_META: missing string table.");
399 // Parse and assign the string table.
400 P.StrTab.emplace(*StrTabBuf);
401 return Error::success();
402}
403
404static Error processRemarkVersion(BitstreamRemarkParser &P,
405 Optional<uint64_t> RemarkVersion) {
406 if (!RemarkVersion)
407 return createStringError(
408 std::make_error_code(std::errc::illegal_byte_sequence),
409 "Error while parsing BLOCK_META: missing remark version.");
410 P.RemarkVersion = *RemarkVersion;
411 return Error::success();
412}
413
414Error BitstreamRemarkParser::processExternalFilePath(
415 Optional<StringRef> ExternalFilePath) {
416 if (!ExternalFilePath)
417 return createStringError(
418 std::make_error_code(std::errc::illegal_byte_sequence),
419 "Error while parsing BLOCK_META: missing external file path.");
420
421 SmallString<80> FullPath(ExternalFilePrependPath);
422 sys::path::append(FullPath, *ExternalFilePath);
423
424 // External file: open the external file, parse it, check if its metadata
425 // matches the one from the separate metadata, then replace the current parser
426 // with the one parsing the remarks.
427 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
428 MemoryBuffer::getFile(FullPath);
429 if (std::error_code EC = BufferOrErr.getError())
430 return createFileError(FullPath, EC);
431 TmpRemarkBuffer = std::move(*BufferOrErr);
432
433 // Create a separate parser used for parsing the separate file.
434 ParserHelper = BitstreamParserHelper(TmpRemarkBuffer->getBuffer());
435 // Advance and check until we can parse the meta block.
436 if (Error E = advanceToMetaBlock(ParserHelper))
437 return E;
438 // Parse the meta from the separate file.
439 // Note: here we overwrite the BlockInfo with the one from the file. This will
440 // be used to parse the rest of the file.
441 BitstreamMetaParserHelper SeparateMetaHelper(ParserHelper.Stream,
442 ParserHelper.BlockInfo);
443 if (Error E = SeparateMetaHelper.parse())
444 return E;
445
446 uint64_t PreviousContainerVersion = ContainerVersion;
447 if (Error E = processCommonMeta(SeparateMetaHelper))
448 return E;
449
450 if (ContainerType != BitstreamRemarkContainerType::SeparateRemarksFile)
451 return createStringError(
452 std::make_error_code(std::errc::illegal_byte_sequence),
453 "Error while parsing external file's BLOCK_META: wrong container "
454 "type.");
455
456 if (PreviousContainerVersion != ContainerVersion)
457 return createStringError(
458 std::make_error_code(std::errc::illegal_byte_sequence),
459 "Error while parsing external file's BLOCK_META: mismatching versions: "
460 "original meta: %lu, external file meta: %lu.",
461 PreviousContainerVersion, ContainerVersion);
462
463 // Process the meta from the separate file.
464 return processSeparateRemarksFileMeta(SeparateMetaHelper);
465}
466
467Error BitstreamRemarkParser::processStandaloneMeta(
468 BitstreamMetaParserHelper &Helper) {
469 if (Error E = processStrTab(*this, Helper.StrTabBuf))
470 return E;
471 return processRemarkVersion(*this, Helper.RemarkVersion);
472}
473
474Error BitstreamRemarkParser::processSeparateRemarksFileMeta(
475 BitstreamMetaParserHelper &Helper) {
476 return processRemarkVersion(*this, Helper.RemarkVersion);
477}
478
479Error BitstreamRemarkParser::processSeparateRemarksMetaMeta(
480 BitstreamMetaParserHelper &Helper) {
481 if (Error E = processStrTab(*this, Helper.StrTabBuf))
482 return E;
483 return processExternalFilePath(Helper.ExternalFilePath);
484}
485
486Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::parseRemark() {
487 BitstreamRemarkParserHelper RemarkHelper(ParserHelper.Stream);
488 if (Error E = RemarkHelper.parse())
489 return std::move(E);
490
491 return processRemark(RemarkHelper);
492}
493
494Expected<std::unique_ptr<Remark>>
495BitstreamRemarkParser::processRemark(BitstreamRemarkParserHelper &Helper) {
496 std::unique_ptr<Remark> Result = std::make_unique<Remark>();
497 Remark &R = *Result;
498
499 if (StrTab == None)
500 return createStringError(
501 std::make_error_code(std::errc::invalid_argument),
502 "Error while parsing BLOCK_REMARK: missing string table.");
503
504 if (!Helper.Type)
505 return createStringError(
506 std::make_error_code(std::errc::illegal_byte_sequence),
507 "Error while parsing BLOCK_REMARK: missing remark type.");
508
509 // Always >= Type::First since it's unsigned.
510 if (*Helper.Type > static_cast<uint8_t>(Type::Last))
511 return createStringError(
512 std::make_error_code(std::errc::illegal_byte_sequence),
513 "Error while parsing BLOCK_REMARK: unknown remark type.");
514
515 R.RemarkType = static_cast<Type>(*Helper.Type);
516
517 if (!Helper.RemarkNameIdx)
518 return createStringError(
519 std::make_error_code(std::errc::illegal_byte_sequence),
520 "Error while parsing BLOCK_REMARK: missing remark name.");
521
522 if (Expected<StringRef> RemarkName = (*StrTab)[*Helper.RemarkNameIdx])
523 R.RemarkName = *RemarkName;
524 else
525 return RemarkName.takeError();
526
527 if (!Helper.PassNameIdx)
528 return createStringError(
529 std::make_error_code(std::errc::illegal_byte_sequence),
530 "Error while parsing BLOCK_REMARK: missing remark pass.");
531
532 if (Expected<StringRef> PassName = (*StrTab)[*Helper.PassNameIdx])
533 R.PassName = *PassName;
534 else
535 return PassName.takeError();
536
537 if (!Helper.FunctionNameIdx)
538 return createStringError(
539 std::make_error_code(std::errc::illegal_byte_sequence),
540 "Error while parsing BLOCK_REMARK: missing remark function name.");
541 if (Expected<StringRef> FunctionName = (*StrTab)[*Helper.FunctionNameIdx])
542 R.FunctionName = *FunctionName;
543 else
544 return FunctionName.takeError();
545
546 if (Helper.SourceFileNameIdx && Helper.SourceLine && Helper.SourceColumn) {
547 Expected<StringRef> SourceFileName = (*StrTab)[*Helper.SourceFileNameIdx];
548 if (!SourceFileName)
549 return SourceFileName.takeError();
550 R.Loc.emplace();
551 R.Loc->SourceFilePath = *SourceFileName;
552 R.Loc->SourceLine = *Helper.SourceLine;
553 R.Loc->SourceColumn = *Helper.SourceColumn;
554 }
555
556 if (Helper.Hotness)
557 R.Hotness = *Helper.Hotness;
558
559 if (!Helper.Args)
560 return std::move(Result);
561
562 for (const BitstreamRemarkParserHelper::Argument &Arg : *Helper.Args) {
563 if (!Arg.KeyIdx)
564 return createStringError(
565 std::make_error_code(std::errc::illegal_byte_sequence),
566 "Error while parsing BLOCK_REMARK: missing key in remark argument.");
567 if (!Arg.ValueIdx)
568 return createStringError(
569 std::make_error_code(std::errc::illegal_byte_sequence),
570 "Error while parsing BLOCK_REMARK: missing value in remark "
571 "argument.");
572
573 // We have at least a key and a value, create an entry.
574 R.Args.emplace_back();
575
576 if (Expected<StringRef> Key = (*StrTab)[*Arg.KeyIdx])
577 R.Args.back().Key = *Key;
578 else
579 return Key.takeError();
580
581 if (Expected<StringRef> Value = (*StrTab)[*Arg.ValueIdx])
582 R.Args.back().Val = *Value;
583 else
584 return Value.takeError();
585
586 if (Arg.SourceFileNameIdx && Arg.SourceLine && Arg.SourceColumn) {
587 if (Expected<StringRef> SourceFileName =
588 (*StrTab)[*Arg.SourceFileNameIdx]) {
589 R.Args.back().Loc.emplace();
590 R.Args.back().Loc->SourceFilePath = *SourceFileName;
591 R.Args.back().Loc->SourceLine = *Arg.SourceLine;
592 R.Args.back().Loc->SourceColumn = *Arg.SourceColumn;
593 } else
594 return SourceFileName.takeError();
595 }
596 }
597
598 return std::move(Result);
599}

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/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/ErrorHandling.h"
22#include "llvm/Support/MathExtras.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include <algorithm>
25#include <cassert>
26#include <climits>
27#include <cstddef>
28#include <cstdint>
29#include <memory>
30#include <string>
31#include <utility>
32#include <vector>
33
34namespace llvm {
35
36/// This class maintains the abbreviations read from a block info block.
37class BitstreamBlockInfo {
38public:
39 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
40 /// describe abbreviations that all blocks of the specified ID inherit.
41 struct BlockInfo {
42 unsigned BlockID = 0;
43 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
44 std::string Name;
45 std::vector<std::pair<unsigned, std::string>> RecordNames;
46 };
47
48private:
49 std::vector<BlockInfo> BlockInfoRecords;
50
51public:
52 /// If there is block info for the specified ID, return it, otherwise return
53 /// null.
54 const BlockInfo *getBlockInfo(unsigned BlockID) const {
55 // Common case, the most recent entry matches BlockID.
56 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
57 return &BlockInfoRecords.back();
58
59 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
60 i != e; ++i)
61 if (BlockInfoRecords[i].BlockID == BlockID)
62 return &BlockInfoRecords[i];
63 return nullptr;
64 }
65
66 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
67 if (const BlockInfo *BI = getBlockInfo(BlockID))
68 return *const_cast<BlockInfo*>(BI);
69
70 // Otherwise, add a new record.
71 BlockInfoRecords.emplace_back();
72 BlockInfoRecords.back().BlockID = BlockID;
73 return BlockInfoRecords.back();
74 }
75};
76
77/// This represents a position within a bitstream. There may be multiple
78/// independent cursors reading within one bitstream, each maintaining their
79/// own local state.
80class SimpleBitstreamCursor {
81 ArrayRef<uint8_t> BitcodeBytes;
82 size_t NextChar = 0;
83
84public:
85 /// This is the current data we have pulled from the stream but have not
86 /// returned to the client. This is specifically and intentionally defined to
87 /// follow the word size of the host machine for efficiency. We use word_t in
88 /// places that are aware of this to make it perfectly explicit what is going
89 /// on.
90 using word_t = size_t;
91
92private:
93 word_t CurWord = 0;
94
95 /// This is the number of bits in CurWord that are valid. This is always from
96 /// [0...bits_of(size_t)-1] inclusive.
97 unsigned BitsInCurWord = 0;
98
99public:
100 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
101
102 SimpleBitstreamCursor() = default;
103 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
104 : BitcodeBytes(BitcodeBytes) {}
105 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
106 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
107 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
108 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
109
110 bool canSkipToPos(size_t pos) const {
111 // pos can be skipped to if it is a valid address or one byte past the end.
112 return pos <= BitcodeBytes.size();
113 }
114
115 bool AtEndOfStream() {
116 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
117 }
118
119 /// Return the bit # of the bit we are reading.
120 uint64_t GetCurrentBitNo() const {
121 return NextChar*CHAR_BIT8 - BitsInCurWord;
122 }
123
124 // Return the byte # of the current bit.
125 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
126
127 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
128
129 /// Reset the stream to the specified bit number.
130 Error JumpToBit(uint64_t BitNo) {
131 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
132 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
133 assert(canSkipToPos(ByteNo) && "Invalid location")((canSkipToPos(ByteNo) && "Invalid location") ? static_cast
<void> (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 133, __PRETTY_FUNCTION__))
;
134
135 // Move the cursor to the right word.
136 NextChar = ByteNo;
137 BitsInCurWord = 0;
138
139 // Skip over any bits that are already consumed.
140 if (WordBitNo) {
141 if (Expected<word_t> Res = Read(WordBitNo))
142 return Error::success();
143 else
144 return Res.takeError();
145 }
146
147 return Error::success();
148 }
149
150 /// Get a pointer into the bitstream at the specified byte offset.
151 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
152 return BitcodeBytes.data() + ByteNo;
153 }
154
155 /// Get a pointer into the bitstream at the specified bit offset.
156 ///
157 /// The bit offset must be on a byte boundary.
158 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
159 assert(!(BitNo % 8) && "Expected bit on byte boundary")((!(BitNo % 8) && "Expected bit on byte boundary") ? static_cast
<void> (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 159, __PRETTY_FUNCTION__))
;
160 return getPointerToByte(BitNo / 8, NumBytes);
161 }
162
163 Error fillCurWord() {
164 if (NextChar >= BitcodeBytes.size())
165 return createStringError(std::errc::io_error,
166 "Unexpected end of file reading %u of %u bytes",
167 NextChar, BitcodeBytes.size());
168
169 // Read the next word from the stream.
170 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
171 unsigned BytesRead;
172 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
173 BytesRead = sizeof(word_t);
174 CurWord =
175 support::endian::read<word_t, support::little, support::unaligned>(
176 NextCharPtr);
177 } else {
178 // Short read.
179 BytesRead = BitcodeBytes.size() - NextChar;
180 CurWord = 0;
181 for (unsigned B = 0; B != BytesRead; ++B)
182 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
183 }
184 NextChar += BytesRead;
185 BitsInCurWord = BytesRead * 8;
186 return Error::success();
187 }
188
189 Expected<word_t> Read(unsigned NumBits) {
190 static const unsigned BitsInWord = MaxChunkSize;
191
192 assert
3.1
'NumBits' is 8
3.2
'NumBits' is <= 'BitsInWord'
3.1
'NumBits' is 8
3.2
'NumBits' is <= 'BitsInWord'
3.1
'NumBits' is 8
3.2
'NumBits' is <= 'BitsInWord'(NumBits && NumBits <= BitsInWord &&((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
4
'?' condition is true
193 "Cannot return zero or more than BitsInWord bits!")((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
; 194 195 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
5
'?' condition is true
196 197 // If the field is fully contained by CurWord, return it quickly. 198 if (BitsInCurWord >= NumBits) {
6
Assuming 'NumBits' is > field 'BitsInCurWord'
7
Taking false branch
199 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits)); 200 201 // Use a mask to avoid undefined behavior. 202 CurWord >>= (NumBits & Mask); 203 204 BitsInCurWord -= NumBits; 205 return R; 206 } 207 208 word_t R = BitsInCurWord ? CurWord : 0;
8
Assuming field 'BitsInCurWord' is not equal to 0
9
'?' condition is true
209 unsigned BitsLeft = NumBits - BitsInCurWord; 210 211 if (Error fillResult = fillCurWord())
10
Calling 'Error::operator bool'
12
Returning from 'Error::operator bool'
13
Taking false branch
212 return std::move(fillResult); 213 214 // If we run out of data, abort. 215 if (BitsLeft > BitsInCurWord)
14
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
15
Taking false branch
216 return createStringError(std::errc::io_error, 217 "Unexpected end of file reading %u of %u bits", 218 BitsInCurWord, BitsLeft); 219 220 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
16
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
221 222 // Use a mask to avoid undefined behavior. 223 CurWord >>= (BitsLeft & Mask); 224 225 BitsInCurWord -= BitsLeft; 226 227 R |= R2 << (NumBits - BitsLeft); 228 229 return R; 230 } 231 232 Expected<uint32_t> ReadVBR(unsigned NumBits) { 233 Expected<unsigned> MaybeRead = Read(NumBits); 234 if (!MaybeRead) 235 return MaybeRead; 236 uint32_t Piece = MaybeRead.get(); 237 238 if ((Piece & (1U << (NumBits-1))) == 0) 239 return Piece; 240 241 uint32_t Result = 0; 242 unsigned NextBit = 0; 243 while (true) { 244 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit; 245 246 if ((Piece & (1U << (NumBits-1))) == 0) 247 return Result; 248 249 NextBit += NumBits-1; 250 MaybeRead = Read(NumBits); 251 if (!MaybeRead) 252 return MaybeRead; 253 Piece = MaybeRead.get(); 254 } 255 } 256 257 // Read a VBR that may have a value up to 64-bits in size. The chunk size of 258 // the VBR must still be <= 32 bits though. 259 Expected<uint64_t> ReadVBR64(unsigned NumBits) { 260 Expected<uint64_t> MaybeRead = Read(NumBits); 261 if (!MaybeRead) 262 return MaybeRead; 263 uint32_t Piece = MaybeRead.get(); 264 265 if ((Piece & (1U << (NumBits-1))) == 0) 266 return uint64_t(Piece); 267 268 uint64_t Result = 0; 269 unsigned NextBit = 0; 270 while (true) { 271 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit; 272 273 if ((Piece & (1U << (NumBits-1))) == 0) 274 return Result; 275 276 NextBit += NumBits-1; 277 MaybeRead = Read(NumBits); 278 if (!MaybeRead) 279 return MaybeRead; 280 Piece = MaybeRead.get(); 281 } 282 } 283 284 void SkipToFourByteBoundary() { 285 // If word_t is 64-bits and if we've read less than 32 bits, just dump 286 // the bits we have up to the next 32-bit boundary. 287 if (sizeof(word_t) > 4 && 288 BitsInCurWord >= 32) { 289 CurWord >>= BitsInCurWord-32; 290 BitsInCurWord = 32; 291 return; 292 } 293 294 BitsInCurWord = 0; 295 } 296 297 /// Return the size of the stream in bytes. 298 size_t SizeInBytes() const { return BitcodeBytes.size(); } 299 300 /// Skip to the end of the file. 301 void skipToEnd() { NextChar = BitcodeBytes.size(); } 302}; 303 304/// When advancing through a bitstream cursor, each advance can discover a few 305/// different kinds of entries: 306struct BitstreamEntry { 307 enum { 308 Error, // Malformed bitcode was found. 309 EndBlock, // We've reached the end of the current block, (or the end of the 310 // file, which is treated like a series of EndBlock records. 311 SubBlock, // This is the start of a new subblock of a specific ID. 312 Record // This is a record with a specific AbbrevID. 313 } Kind; 314 315 unsigned ID; 316 317 static BitstreamEntry getError() { 318 BitstreamEntry E; E.Kind = Error; return E; 319 } 320 321 static BitstreamEntry getEndBlock() { 322 BitstreamEntry E; E.Kind = EndBlock; return E; 323 } 324 325 static BitstreamEntry getSubBlock(unsigned ID) { 326 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E; 327 } 328 329 static BitstreamEntry getRecord(unsigned AbbrevID) { 330 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E; 331 } 332}; 333 334/// This represents a position within a bitcode file, implemented on top of a 335/// SimpleBitstreamCursor. 336/// 337/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not 338/// be passed by value. 339class BitstreamCursor : SimpleBitstreamCursor { 340 // This is the declared size of code values used for the current block, in 341 // bits. 342 unsigned CurCodeSize = 2; 343 344 /// Abbrevs installed at in this block. 345 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs; 346 347 struct Block { 348 unsigned PrevCodeSize; 349 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs; 350 351 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {} 352 }; 353 354 /// This tracks the codesize of parent blocks. 355 SmallVector<Block, 8> BlockScope; 356 357 BitstreamBlockInfo *BlockInfo = nullptr; 358 359public: 360 static const size_t MaxChunkSize = sizeof(word_t) * 8; 361 362 BitstreamCursor() = default; 363 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes) 364 : SimpleBitstreamCursor(BitcodeBytes) {} 365 explicit BitstreamCursor(StringRef BitcodeBytes) 366 : SimpleBitstreamCursor(BitcodeBytes) {} 367 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes) 368 : SimpleBitstreamCursor(BitcodeBytes) {} 369 370 using SimpleBitstreamCursor::AtEndOfStream; 371 using SimpleBitstreamCursor::canSkipToPos; 372 using SimpleBitstreamCursor::fillCurWord; 373 using SimpleBitstreamCursor::getBitcodeBytes; 374 using SimpleBitstreamCursor::GetCurrentBitNo; 375 using SimpleBitstreamCursor::getCurrentByteNo; 376 using SimpleBitstreamCursor::getPointerToByte; 377 using SimpleBitstreamCursor::JumpToBit; 378 using SimpleBitstreamCursor::Read; 379 using SimpleBitstreamCursor::ReadVBR; 380 using SimpleBitstreamCursor::ReadVBR64; 381 using SimpleBitstreamCursor::SizeInBytes; 382 using SimpleBitstreamCursor::skipToEnd; 383 384 /// Return the number of bits used to encode an abbrev #. 385 unsigned getAbbrevIDWidth() const { return CurCodeSize; } 386 387 /// Flags that modify the behavior of advance(). 388 enum { 389 /// If this flag is used, the advance() method does not automatically pop 390 /// the block scope when the end of a block is reached. 391 AF_DontPopBlockAtEnd = 1, 392 393 /// If this flag is used, abbrev entries are returned just like normal 394 /// records. 395 AF_DontAutoprocessAbbrevs = 2 396 }; 397 398 /// Advance the current bitstream, returning the next entry in the stream. 399 Expected<BitstreamEntry> advance(unsigned Flags = 0) { 400 while (true) { 401 if (AtEndOfStream()) 402 return BitstreamEntry::getError(); 403 404 Expected<unsigned> MaybeCode = ReadCode(); 405 if (!MaybeCode) 406 return MaybeCode.takeError(); 407 unsigned Code = MaybeCode.get(); 408 409 if (Code == bitc::END_BLOCK) { 410 // Pop the end of the block unless Flags tells us not to. 411 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd()) 412 return BitstreamEntry::getError(); 413 return BitstreamEntry::getEndBlock(); 414 } 415 416 if (Code == bitc::ENTER_SUBBLOCK) { 417 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID()) 418 return BitstreamEntry::getSubBlock(MaybeSubBlock.get()); 419 else 420 return MaybeSubBlock.takeError(); 421 } 422 423 if (Code == bitc::DEFINE_ABBREV && 424 !(Flags & AF_DontAutoprocessAbbrevs)) { 425 // We read and accumulate abbrev's, the client can't do anything with 426 // them anyway. 427 if (Error Err = ReadAbbrevRecord()) 428 return std::move(Err); 429 continue; 430 } 431 432 return BitstreamEntry::getRecord(Code); 433 } 434 } 435 436 /// This is a convenience function for clients that don't expect any 437 /// subblocks. This just skips over them automatically. 438 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) { 439 while (true) { 440 // If we found a normal entry, return it. 441 Expected<BitstreamEntry> MaybeEntry = advance(Flags); 442 if (!MaybeEntry) 443 return MaybeEntry; 444 BitstreamEntry Entry = MaybeEntry.get(); 445 446 if (Entry.Kind != BitstreamEntry::SubBlock) 447 return Entry; 448 449 // If we found a sub-block, just skip over it and check the next entry. 450 if (Error Err = SkipBlock()) 451 return std::move(Err); 452 } 453 } 454 455 Expected<unsigned> ReadCode() { return Read(CurCodeSize); } 456 457 // Block header: 458 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen] 459 460 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block. 461 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); } 462 463 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body 464 /// of this block. 465 Error SkipBlock() { 466 // Read and ignore the codelen value. 467 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth)) 468 ; // Since we are skipping this block, we don't care what code widths are 469 // used inside of it. 470 else 471 return Res.takeError(); 472 473 SkipToFourByteBoundary(); 474 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth); 475 if (!MaybeNum) 476 return MaybeNum.takeError(); 477 size_t NumFourBytes = MaybeNum.get(); 478 479 // Check that the block wasn't partially defined, and that the offset isn't 480 // bogus. 481 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8; 482 if (AtEndOfStream()) 483 return createStringError(std::errc::illegal_byte_sequence, 484 "can't skip block: already at end of stream"); 485 if (!canSkipToPos(SkipTo / 8)) 486 return createStringError(std::errc::illegal_byte_sequence, 487 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo, 488 GetCurrentBitNo()); 489 490 if (Error Res = JumpToBit(SkipTo)) 491 return Res; 492 493 return Error::success(); 494 } 495 496 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block. 497 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr); 498 499 bool ReadBlockEnd() { 500 if (BlockScope.empty()) return true; 501 502 // Block tail: 503 // [END_BLOCK, <align4bytes>] 504 SkipToFourByteBoundary(); 505 506 popBlockScope(); 507 return false; 508 } 509 510private: 511 void popBlockScope() { 512 CurCodeSize = BlockScope.back().PrevCodeSize; 513 514 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs); 515 BlockScope.pop_back(); 516 } 517 518 //===--------------------------------------------------------------------===// 519 // Record Processing 520 //===--------------------------------------------------------------------===// 521 522public: 523 /// Return the abbreviation for the specified AbbrevId. 524 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) { 525 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV; 526 if (AbbrevNo >= CurAbbrevs.size()) 527 report_fatal_error("Invalid abbrev number"); 528 return CurAbbrevs[AbbrevNo].get(); 529 } 530 531 /// Read the current record and discard it, returning the code for the record. 532 Expected<unsigned> skipRecord(unsigned AbbrevID); 533 534 Expected<unsigned> readRecord(unsigned AbbrevID, 535 SmallVectorImpl<uint64_t> &Vals, 536 StringRef *Blob = nullptr); 537 538 //===--------------------------------------------------------------------===// 539 // Abbrev Processing 540 //===--------------------------------------------------------------------===// 541 Error ReadAbbrevRecord(); 542 543 /// Read and return a block info block from the bitstream. If an error was 544 /// encountered, return None. 545 /// 546 /// \param ReadBlockInfoNames Whether to read block/record name information in 547 /// the BlockInfo block. Only llvm-bcanalyzer uses this. 548 Expected<Optional<BitstreamBlockInfo>> 549 ReadBlockInfoBlock(bool ReadBlockInfoNames = false); 550 551 /// Set the block info to be used by this BitstreamCursor to interpret 552 /// abbreviated records. 553 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; } 554}; 555 556} // end llvm namespace 557 558#endif // LLVM_BITSTREAM_BITSTREAMREADER_H

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/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 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
159 // pointers out of this class to add to the error list.
160 friend class ErrorList;
161 friend class FileError;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
11
Returning zero, which participates in a condition later
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
266 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275 }
276
277 void setPtr(ErrorInfoBase *EI) {
278#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
279 Payload = reinterpret_cast<ErrorInfoBase*>(
280 (reinterpret_cast<uintptr_t>(EI) &
281 ~static_cast<uintptr_t>(0x1)) |
282 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
283#else
284 Payload = EI;
285#endif
286 }
287
288 bool getChecked() const {
289#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
290 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
291#else
292 return true;
293#endif
294 }
295
296 void setChecked(bool V) {
297 Payload = reinterpret_cast<ErrorInfoBase*>(
298 (reinterpret_cast<uintptr_t>(Payload) &
299 ~static_cast<uintptr_t>(0x1)) |
300 (V ? 0 : 1));
301 }
302
303 std::unique_ptr<ErrorInfoBase> takePayload() {
304 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
305 setPtr(nullptr);
306 setChecked(true);
307 return Tmp;
308 }
309
310 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
311 if (auto P = E.getPtr())
312 P->log(OS);
313 else
314 OS << "success";
315 return OS;
316 }
317
318 ErrorInfoBase *Payload = nullptr;
319};
320
321/// Subclass of Error for the sole purpose of identifying the success path in
322/// the type system. This allows to catch invalid conversion to Expected<T> at
323/// compile time.
324class ErrorSuccess final : public Error {};
325
326inline ErrorSuccess Error::success() { return ErrorSuccess(); }
327
328/// Make a Error instance representing failure using the given error info
329/// type.
330template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
331 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
332}
333
334/// Base class for user error types. Users should declare their error types
335/// like:
336///
337/// class MyError : public ErrorInfo<MyError> {
338/// ....
339/// };
340///
341/// This class provides an implementation of the ErrorInfoBase::kind
342/// method, which is used by the Error RTTI system.
343template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
344class ErrorInfo : public ParentErrT {
345public:
346 using ParentErrT::ParentErrT; // inherit constructors
347
348 static const void *classID() { return &ThisErrT::ID; }
349
350 const void *dynamicClassID() const override { return &ThisErrT::ID; }
351
352 bool isA(const void *const ClassID) const override {
353 return ClassID == classID() || ParentErrT::isA(ClassID);
354 }
355};
356
357/// Special ErrorInfo subclass representing a list of ErrorInfos.
358/// Instances of this class are constructed by joinError.
359class ErrorList final : public ErrorInfo<ErrorList> {
360 // handleErrors needs to be able to iterate the payload list of an
361 // ErrorList.
362 template <typename... HandlerTs>
363 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
364
365 // joinErrors is implemented in terms of join.
366 friend Error joinErrors(Error, Error);
367
368public:
369 void log(raw_ostream &OS) const override {
370 OS << "Multiple errors:\n";
371 for (auto &ErrPayload : Payloads) {
372 ErrPayload->log(OS);
373 OS << "\n";
374 }
375 }
376
377 std::error_code convertToErrorCode() const override;
378
379 // Used by ErrorInfo::classID.
380 static char ID;
381
382private:
383 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
384 std::unique_ptr<ErrorInfoBase> Payload2) {
385 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
386 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
;
387 Payloads.push_back(std::move(Payload1));
388 Payloads.push_back(std::move(Payload2));
389 }
390
391 static Error join(Error E1, Error E2) {
392 if (!E1)
393 return E2;
394 if (!E2)
395 return E1;
396 if (E1.isA<ErrorList>()) {
397 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
398 if (E2.isA<ErrorList>()) {
399 auto E2Payload = E2.takePayload();
400 auto &E2List = static_cast<ErrorList &>(*E2Payload);
401 for (auto &Payload : E2List.Payloads)
402 E1List.Payloads.push_back(std::move(Payload));
403 } else
404 E1List.Payloads.push_back(E2.takePayload());
405
406 return E1;
407 }
408 if (E2.isA<ErrorList>()) {
409 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
410 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
411 return E2;
412 }
413 return Error(std::unique_ptr<ErrorList>(
414 new ErrorList(E1.takePayload(), E2.takePayload())));
415 }
416
417 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
418};
419
420/// Concatenate errors. The resulting Error is unchecked, and contains the
421/// ErrorInfo(s), if any, contained in E1, followed by the
422/// ErrorInfo(s), if any, contained in E2.
423inline Error joinErrors(Error E1, Error E2) {
424 return ErrorList::join(std::move(E1), std::move(E2));
425}
426
427/// Tagged union holding either a T or a Error.
428///
429/// This class parallels ErrorOr, but replaces error_code with Error. Since
430/// Error cannot be copied, this class replaces getError() with
431/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
432/// error class type.
433template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
434 template <class T1> friend class ExpectedAsOutParameter;
435 template <class OtherT> friend class Expected;
436
437 static const bool isRef = std::is_reference<T>::value;
438
439 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
440
441 using error_type = std::unique_ptr<ErrorInfoBase>;
442
443public:
444 using storage_type = typename std::conditional<isRef, wrap, T>::type;
445 using value_type = T;
446
447private:
448 using reference = typename std::remove_reference<T>::type &;
449 using const_reference = const typename std::remove_reference<T>::type &;
450 using pointer = typename std::remove_reference<T>::type *;
451 using const_pointer = const typename std::remove_reference<T>::type *;
452
453public:
454 /// Create an Expected<T> error value from the given Error.
455 Expected(Error Err)
456 : HasError(true)
457#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
458 // Expected is unchecked upon construction in Debug builds.
459 , Unchecked(true)
460#endif
461 {
462 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 462, __PRETTY_FUNCTION__))
;
463 new (getErrorStorage()) error_type(Err.takePayload());
464 }
465
466 /// Forbid to convert from Error::success() implicitly, this avoids having
467 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
468 /// but triggers the assertion above.
469 Expected(ErrorSuccess) = delete;
470
471 /// Create an Expected<T> success value from the given OtherT value, which
472 /// must be convertible to T.
473 template <typename OtherT>
474 Expected(OtherT &&Val,
475 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
476 * = nullptr)
477 : HasError(false)
478#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
479 // Expected is unchecked upon construction in Debug builds.
480 , Unchecked(true)
481#endif
482 {
483 new (getStorage()) storage_type(std::forward<OtherT>(Val));
484 }
485
486 /// Move construct an Expected<T> value.
487 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
488
489 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
490 /// must be convertible to T.
491 template <class OtherT>
492 Expected(Expected<OtherT> &&Other,
493 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
494 * = nullptr) {
495 moveConstruct(std::move(Other));
496 }
497
498 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
499 /// isn't convertible to T.
500 template <class OtherT>
501 explicit Expected(
502 Expected<OtherT> &&Other,
503 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
504 nullptr) {
505 moveConstruct(std::move(Other));
506 }
507
508 /// Move-assign from another Expected<T>.
509 Expected &operator=(Expected &&Other) {
510 moveAssign(std::move(Other));
511 return *this;
512 }
513
514 /// Destroy an Expected<T>.
515 ~Expected() {
516 assertIsChecked();
517 if (!HasError)
518 getStorage()->~storage_type();
519 else
520 getErrorStorage()->~error_type();
521 }
522
523 /// Return false if there is an error.
524 explicit operator bool() {
525#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
526 Unchecked = HasError;
527#endif
528 return !HasError;
529 }
530
531 /// Returns a reference to the stored T value.
532 reference get() {
533 assertIsChecked();
534 return *getStorage();
535 }
536
537 /// Returns a const reference to the stored T value.
538 const_reference get() const {
539 assertIsChecked();
540 return const_cast<Expected<T> *>(this)->get();
541 }
542
543 /// Check that this Expected<T> is an error of type ErrT.
544 template <typename ErrT> bool errorIsA() const {
545 return HasError && (*getErrorStorage())->template isA<ErrT>();
546 }
547
548 /// Take ownership of the stored error.
549 /// After calling this the Expected<T> is in an indeterminate state that can
550 /// only be safely destructed. No further calls (beside the destructor) should
551 /// be made on the Expected<T> value.
552 Error takeError() {
553#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
554 Unchecked = false;
555#endif
556 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
557 }
558
559 /// Returns a pointer to the stored T value.
560 pointer operator->() {
561 assertIsChecked();
562 return toPointer(getStorage());
563 }
564
565 /// Returns a const pointer to the stored T value.
566 const_pointer operator->() const {
567 assertIsChecked();
568 return toPointer(getStorage());
569 }
570
571 /// Returns a reference to the stored T value.
572 reference operator*() {
573 assertIsChecked();
574 return *getStorage();
575 }
576
577 /// Returns a const reference to the stored T value.
578 const_reference operator*() const {
579 assertIsChecked();
580 return *getStorage();
581 }
582
583private:
584 template <class T1>
585 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
586 return &a == &b;
587 }
588
589 template <class T1, class T2>
590 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
591 return false;
592 }
593
594 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
595 HasError = Other.HasError;
596#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
597 Unchecked = true;
598 Other.Unchecked = false;
599#endif
600
601 if (!HasError)
602 new (getStorage()) storage_type(std::move(*Other.getStorage()));
603 else
604 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
605 }
606
607 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
608 assertIsChecked();
609
610 if (compareThisIfSameType(*this, Other))
611 return;
612
613 this->~Expected();
614 new (this) Expected(std::move(Other));
615 }
616
617 pointer toPointer(pointer Val) { return Val; }
618
619 const_pointer toPointer(const_pointer Val) const { return Val; }
620
621 pointer toPointer(wrap *Val) { return &Val->get(); }
622
623 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
624
625 storage_type *getStorage() {
626 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 626, __PRETTY_FUNCTION__))
;
627 return reinterpret_cast<storage_type *>(TStorage.buffer);
628 }
629
630 const storage_type *getStorage() const {
631 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 631, __PRETTY_FUNCTION__))
;
632 return reinterpret_cast<const storage_type *>(TStorage.buffer);
633 }
634
635 error_type *getErrorStorage() {
636 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 636, __PRETTY_FUNCTION__))
;
637 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
638 }
639
640 const error_type *getErrorStorage() const {
641 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 641, __PRETTY_FUNCTION__))
;
642 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
643 }
644
645 // Used by ExpectedAsOutParameter to reset the checked flag.
646 void setUnchecked() {
647#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
648 Unchecked = true;
649#endif
650 }
651
652#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
653 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
654 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
655 void fatalUncheckedExpected() const {
656 dbgs() << "Expected<T> must be checked before access or destruction.\n";
657 if (HasError) {
658 dbgs() << "Unchecked Expected<T> contained error:\n";
659 (*getErrorStorage())->log(dbgs());
660 } else
661 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
662 "values in success mode must still be checked prior to being "
663 "destroyed).\n";
664 abort();
665 }
666#endif
667
668 void assertIsChecked() {
669#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
670 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
671 fatalUncheckedExpected();
672#endif
673 }
674
675 union {
676 AlignedCharArrayUnion<storage_type> TStorage;
677 AlignedCharArrayUnion<error_type> ErrorStorage;
678 };
679 bool HasError : 1;
680#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
681 bool Unchecked : 1;
682#endif
683};
684
685/// Report a serious error, calling any installed error handler. See
686/// ErrorHandling.h.
687LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
688 bool gen_crash_diag = true);
689
690/// Report a fatal error if Err is a failure value.
691///
692/// This function can be used to wrap calls to fallible functions ONLY when it
693/// is known that the Error will always be a success value. E.g.
694///
695/// @code{.cpp}
696/// // foo only attempts the fallible operation if DoFallibleOperation is
697/// // true. If DoFallibleOperation is false then foo always returns
698/// // Error::success().
699/// Error foo(bool DoFallibleOperation);
700///
701/// cantFail(foo(false));
702/// @endcode
703inline void cantFail(Error Err, const char *Msg = nullptr) {
704 if (Err) {
705 if (!Msg)
706 Msg = "Failure value returned from cantFail wrapped call";
707#ifndef NDEBUG
708 std::string Str;
709 raw_string_ostream OS(Str);
710 OS << Msg << "\n" << Err;
711 Msg = OS.str().c_str();
712#endif
713 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 713)
;
714 }
715}
716
717/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
718/// returns the contained value.
719///
720/// This function can be used to wrap calls to fallible functions ONLY when it
721/// is known that the Error will always be a success value. E.g.
722///
723/// @code{.cpp}
724/// // foo only attempts the fallible operation if DoFallibleOperation is
725/// // true. If DoFallibleOperation is false then foo always returns an int.
726/// Expected<int> foo(bool DoFallibleOperation);
727///
728/// int X = cantFail(foo(false));
729/// @endcode
730template <typename T>
731T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
732 if (ValOrErr)
733 return std::move(*ValOrErr);
734 else {
735 if (!Msg)
736 Msg = "Failure value returned from cantFail wrapped call";
737#ifndef NDEBUG
738 std::string Str;
739 raw_string_ostream OS(Str);
740 auto E = ValOrErr.takeError();
741 OS << Msg << "\n" << E;
742 Msg = OS.str().c_str();
743#endif
744 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 744)
;
745 }
746}
747
748/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
749/// returns the contained reference.
750///
751/// This function can be used to wrap calls to fallible functions ONLY when it
752/// is known that the Error will always be a success value. E.g.
753///
754/// @code{.cpp}
755/// // foo only attempts the fallible operation if DoFallibleOperation is
756/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
757/// Expected<Bar&> foo(bool DoFallibleOperation);
758///
759/// Bar &X = cantFail(foo(false));
760/// @endcode
761template <typename T>
762T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
763 if (ValOrErr)
764 return *ValOrErr;
765 else {
766 if (!Msg)
767 Msg = "Failure value returned from cantFail wrapped call";
768#ifndef NDEBUG
769 std::string Str;
770 raw_string_ostream OS(Str);
771 auto E = ValOrErr.takeError();
772 OS << Msg << "\n" << E;
773 Msg = OS.str().c_str();
774#endif
775 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 775)
;
776 }
777}
778
779/// Helper for testing applicability of, and applying, handlers for
780/// ErrorInfo types.
781template <typename HandlerT>
782class ErrorHandlerTraits
783 : public ErrorHandlerTraits<decltype(
784 &std::remove_reference<HandlerT>::type::operator())> {};
785
786// Specialization functions of the form 'Error (const ErrT&)'.
787template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
788public:
789 static bool appliesTo(const ErrorInfoBase &E) {
790 return E.template isA<ErrT>();
791 }
792
793 template <typename HandlerT>
794 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
795 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 795, __PRETTY_FUNCTION__))
;
796 return H(static_cast<ErrT &>(*E));
797 }
798};
799
800// Specialization functions of the form 'void (const ErrT&)'.
801template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
802public:
803 static bool appliesTo(const ErrorInfoBase &E) {
804 return E.template isA<ErrT>();
805 }
806
807 template <typename HandlerT>
808 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
809 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 809, __PRETTY_FUNCTION__))
;
810 H(static_cast<ErrT &>(*E));
811 return Error::success();
812 }
813};
814
815/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
816template <typename ErrT>
817class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
818public:
819 static bool appliesTo(const ErrorInfoBase &E) {
820 return E.template isA<ErrT>();
821 }
822
823 template <typename HandlerT>
824 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
825 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 825, __PRETTY_FUNCTION__))
;
826 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
827 return H(std::move(SubE));
828 }
829};
830
831/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
832template <typename ErrT>
833class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
834public:
835 static bool appliesTo(const ErrorInfoBase &E) {
836 return E.template isA<ErrT>();
837 }
838
839 template <typename HandlerT>
840 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
841 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 841, __PRETTY_FUNCTION__))
;
842 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
843 H(std::move(SubE));
844 return Error::success();
845 }
846};
847
848// Specialization for member functions of the form 'RetT (const ErrT&)'.
849template <typename C, typename RetT, typename ErrT>
850class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
851 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
852
853// Specialization for member functions of the form 'RetT (const ErrT&) const'.
854template <typename C, typename RetT, typename ErrT>
855class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
856 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
857
858// Specialization for member functions of the form 'RetT (const ErrT&)'.
859template <typename C, typename RetT, typename ErrT>
860class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
861 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
862
863// Specialization for member functions of the form 'RetT (const ErrT&) const'.
864template <typename C, typename RetT, typename ErrT>
865class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
866 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
867
868/// Specialization for member functions of the form
869/// 'RetT (std::unique_ptr<ErrT>)'.
870template <typename C, typename RetT, typename ErrT>
871class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
872 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
873
874/// Specialization for member functions of the form
875/// 'RetT (std::unique_ptr<ErrT>) const'.
876template <typename C, typename RetT, typename ErrT>
877class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
878 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
879
880inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
881 return Error(std::move(Payload));
882}
883
884template <typename HandlerT, typename... HandlerTs>
885Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
886 HandlerT &&Handler, HandlerTs &&... Handlers) {
887 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
888 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
889 std::move(Payload));
890 return handleErrorImpl(std::move(Payload),
891 std::forward<HandlerTs>(Handlers)...);
892}
893
894/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
895/// unhandled errors (or Errors returned by handlers) are re-concatenated and
896/// returned.
897/// Because this function returns an error, its result must also be checked
898/// or returned. If you intend to handle all errors use handleAllErrors
899/// (which returns void, and will abort() on unhandled errors) instead.
900template <typename... HandlerTs>
901Error handleErrors(Error E, HandlerTs &&... Hs) {
902 if (!E)
903 return Error::success();
904
905 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
906
907 if (Payload->isA<ErrorList>()) {
908 ErrorList &List = static_cast<ErrorList &>(*Payload);
909 Error R;
910 for (auto &P : List.Payloads)
911 R = ErrorList::join(
912 std::move(R),
913 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
914 return R;
915 }
916
917 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
918}
919
920/// Behaves the same as handleErrors, except that by contract all errors
921/// *must* be handled by the given handlers (i.e. there must be no remaining
922/// errors after running the handlers, or llvm_unreachable is called).
923template <typename... HandlerTs>
924void handleAllErrors(Error E, HandlerTs &&... Handlers) {
925 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
926}
927
928/// Check that E is a non-error, then drop it.
929/// If E is an error, llvm_unreachable will be called.
930inline void handleAllErrors(Error E) {
931 cantFail(std::move(E));
932}
933
934/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
935///
936/// If the incoming value is a success value it is returned unmodified. If it
937/// is a failure value then it the contained error is passed to handleErrors.
938/// If handleErrors is able to handle the error then the RecoveryPath functor
939/// is called to supply the final result. If handleErrors is not able to
940/// handle all errors then the unhandled errors are returned.
941///
942/// This utility enables the follow pattern:
943///
944/// @code{.cpp}
945/// enum FooStrategy { Aggressive, Conservative };
946/// Expected<Foo> foo(FooStrategy S);
947///
948/// auto ResultOrErr =
949/// handleExpected(
950/// foo(Aggressive),
951/// []() { return foo(Conservative); },
952/// [](AggressiveStrategyError&) {
953/// // Implicitly conusme this - we'll recover by using a conservative
954/// // strategy.
955/// });
956///
957/// @endcode
958template <typename T, typename RecoveryFtor, typename... HandlerTs>
959Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
960 HandlerTs &&... Handlers) {
961 if (ValOrErr)
962 return ValOrErr;
963
964 if (auto Err = handleErrors(ValOrErr.takeError(),
965 std::forward<HandlerTs>(Handlers)...))
966 return std::move(Err);
967
968 return RecoveryPath();
969}
970
971/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
972/// will be printed before the first one is logged. A newline will be printed
973/// after each error.
974///
975/// This function is compatible with the helpers from Support/WithColor.h. You
976/// can pass any of them as the OS. Please consider using them instead of
977/// including 'error: ' in the ErrorBanner.
978///
979/// This is useful in the base level of your program to allow clean termination
980/// (allowing clean deallocation of resources, etc.), while reporting error
981/// information to the user.
982void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
983
984/// Write all error messages (if any) in E to a string. The newline character
985/// is used to separate error messages.
986inline std::string toString(Error E) {
987 SmallVector<std::string, 2> Errors;
988 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
989 Errors.push_back(EI.message());
990 });
991 return join(Errors.begin(), Errors.end(), "\n");
992}
993
994/// Consume a Error without doing anything. This method should be used
995/// only where an error can be considered a reasonable and expected return
996/// value.
997///
998/// Uses of this method are potentially indicative of design problems: If it's
999/// legitimate to do nothing while processing an "error", the error-producer
1000/// might be more clearly refactored to return an Optional<T>.
1001inline void consumeError(Error Err) {
1002 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1003}
1004
1005/// Convert an Expected to an Optional without doing anything. This method
1006/// should be used only where an error can be considered a reasonable and
1007/// expected return value.
1008///
1009/// Uses of this method are potentially indicative of problems: perhaps the
1010/// error should be propagated further, or the error-producer should just
1011/// return an Optional in the first place.
1012template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1013 if (E)
1014 return std::move(*E);
1015 consumeError(E.takeError());
1016 return None;
1017}
1018
1019/// Helper for converting an Error to a bool.
1020///
1021/// This method returns true if Err is in an error state, or false if it is
1022/// in a success state. Puts Err in a checked state in both cases (unlike
1023/// Error::operator bool(), which only does this for success states).
1024inline bool errorToBool(Error Err) {
1025 bool IsError = static_cast<bool>(Err);
1026 if (IsError)
1027 consumeError(std::move(Err));
1028 return IsError;
1029}
1030
1031/// Helper for Errors used as out-parameters.
1032///
1033/// This helper is for use with the Error-as-out-parameter idiom, where an error
1034/// is passed to a function or method by reference, rather than being returned.
1035/// In such cases it is helpful to set the checked bit on entry to the function
1036/// so that the error can be written to (unchecked Errors abort on assignment)
1037/// and clear the checked bit on exit so that clients cannot accidentally forget
1038/// to check the result. This helper performs these actions automatically using
1039/// RAII:
1040///
1041/// @code{.cpp}
1042/// Result foo(Error &Err) {
1043/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1044/// // <body of foo>
1045/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1046/// }
1047/// @endcode
1048///
1049/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1050/// used with optional Errors (Error pointers that are allowed to be null). If
1051/// ErrorAsOutParameter took an Error reference, an instance would have to be
1052/// created inside every condition that verified that Error was non-null. By
1053/// taking an Error pointer we can just create one instance at the top of the
1054/// function.
1055class ErrorAsOutParameter {
1056public:
1057 ErrorAsOutParameter(Error *Err) : Err(Err) {
1058 // Raise the checked bit if Err is success.
1059 if (Err)
1060 (void)!!*Err;
1061 }
1062
1063 ~ErrorAsOutParameter() {
1064 // Clear the checked bit.
1065 if (Err && !*Err)
1066 *Err = Error::success();
1067 }
1068
1069private:
1070 Error *Err;
1071};
1072
1073/// Helper for Expected<T>s used as out-parameters.
1074///
1075/// See ErrorAsOutParameter.
1076template <typename T>
1077class ExpectedAsOutParameter {
1078public:
1079 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1080 : ValOrErr(ValOrErr) {
1081 if (ValOrErr)
1082 (void)!!*ValOrErr;
1083 }
1084
1085 ~ExpectedAsOutParameter() {
1086 if (ValOrErr)
1087 ValOrErr->setUnchecked();
1088 }
1089
1090private:
1091 Expected<T> *ValOrErr;
1092};
1093
1094/// This class wraps a std::error_code in a Error.
1095///
1096/// This is useful if you're writing an interface that returns a Error
1097/// (or Expected) and you want to call code that still returns
1098/// std::error_codes.
1099class ECError : public ErrorInfo<ECError> {
1100 friend Error errorCodeToError(std::error_code);
1101
1102 virtual void anchor() override;
1103
1104public:
1105 void setErrorCode(std::error_code EC) { this->EC = EC; }
1106 std::error_code convertToErrorCode() const override { return EC; }
1107 void log(raw_ostream &OS) const override { OS << EC.message(); }
1108
1109 // Used by ErrorInfo::classID.
1110 static char ID;
1111
1112protected:
1113 ECError() = default;
1114 ECError(std::error_code EC) : EC(EC) {}
1115
1116 std::error_code EC;
1117};
1118
1119/// The value returned by this function can be returned from convertToErrorCode
1120/// for Error values where no sensible translation to std::error_code exists.
1121/// It should only be used in this situation, and should never be used where a
1122/// sensible conversion to std::error_code is available, as attempts to convert
1123/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1124///error to try to convert such a value).
1125std::error_code inconvertibleErrorCode();
1126
1127/// Helper for converting an std::error_code to a Error.
1128Error errorCodeToError(std::error_code EC);
1129
1130/// Helper for converting an ECError to a std::error_code.
1131///
1132/// This method requires that Err be Error() or an ECError, otherwise it
1133/// will trigger a call to abort().
1134std::error_code errorToErrorCode(Error Err);
1135
1136/// Convert an ErrorOr<T> to an Expected<T>.
1137template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1138 if (auto EC = EO.getError())
1139 return errorCodeToError(EC);
1140 return std::move(*EO);
1141}
1142
1143/// Convert an Expected<T> to an ErrorOr<T>.
1144template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1145 if (auto Err = E.takeError())
1146 return errorToErrorCode(std::move(Err));
1147 return std::move(*E);
1148}
1149
1150/// This class wraps a string in an Error.
1151///
1152/// StringError is useful in cases where the client is not expected to be able
1153/// to consume the specific error message programmatically (for example, if the
1154/// error message is to be presented to the user).
1155///
1156/// StringError can also be used when additional information is to be printed
1157/// along with a error_code message. Depending on the constructor called, this
1158/// class can either display:
1159/// 1. the error_code message (ECError behavior)
1160/// 2. a string
1161/// 3. the error_code message and a string
1162///
1163/// These behaviors are useful when subtyping is required; for example, when a
1164/// specific library needs an explicit error type. In the example below,
1165/// PDBError is derived from StringError:
1166///
1167/// @code{.cpp}
1168/// Expected<int> foo() {
1169/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1170/// "Additional information");
1171/// }
1172/// @endcode
1173///
1174class StringError : public ErrorInfo<StringError> {
1175public:
1176 static char ID;
1177
1178 // Prints EC + S and converts to EC
1179 StringError(std::error_code EC, const Twine &S = Twine());
1180
1181 // Prints S and converts to EC
1182 StringError(const Twine &S, std::error_code EC);
1183
1184 void log(raw_ostream &OS) const override;
1185 std::error_code convertToErrorCode() const override;
1186
1187 const std::string &getMessage() const { return Msg; }
1188
1189private:
1190 std::string Msg;
1191 std::error_code EC;
1192 const bool PrintMsgOnly = false;
1193};
1194
1195/// Create formatted StringError object.
1196template <typename... Ts>
1197inline Error createStringError(std::error_code EC, char const *Fmt,
1198 const Ts &... Vals) {
1199 std::string Buffer;
1200 raw_string_ostream Stream(Buffer);
1201 Stream << format(Fmt, Vals...);
1202 return make_error<StringError>(Stream.str(), EC);
1203}
1204
1205Error createStringError(std::error_code EC, char const *Msg);
1206
1207inline Error createStringError(std::error_code EC, const Twine &S) {
1208 return createStringError(EC, S.str().c_str());
1209}
1210
1211template <typename... Ts>
1212inline Error createStringError(std::errc EC, char const *Fmt,
1213 const Ts &... Vals) {
1214 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1215}
1216
1217/// This class wraps a filename and another Error.
1218///
1219/// In some cases, an error needs to live along a 'source' name, in order to
1220/// show more detailed information to the user.
1221class FileError final : public ErrorInfo<FileError> {
1222
1223 friend Error createFileError(const Twine &, Error);
1224 friend Error createFileError(const Twine &, size_t, Error);
1225
1226public:
1227 void log(raw_ostream &OS) const override {
1228 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 1228, __PRETTY_FUNCTION__))
;
1229 OS << "'" << FileName << "': ";
1230 if (Line.hasValue())
1231 OS << "line " << Line.getValue() << ": ";
1232 Err->log(OS);
1233 }
1234
1235 Error takeError() { return Error(std::move(Err)); }
1236
1237 std::error_code convertToErrorCode() const override;
1238
1239 // Used by ErrorInfo::classID.
1240 static char ID;
1241
1242private:
1243 FileError(const Twine &F, Optional<size_t> LineNum,
1244 std::unique_ptr<ErrorInfoBase> E) {
1245 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 1245, __PRETTY_FUNCTION__))
;
1246 assert(!F.isTriviallyEmpty() &&((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 1247, __PRETTY_FUNCTION__))
1247 "The file name provided to FileError must not be empty.")((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include/llvm/Support/Error.h"
, 1247, __PRETTY_FUNCTION__))
;
1248 FileName = F.str();
1249 Err = std::move(E);
1250 Line = std::move(LineNum);
1251 }
1252
1253 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1254 return Error(
1255 std::unique_ptr<FileError>(new FileError(F, Line, E.takePayload())));
1256 }
1257
1258 std::string FileName;
1259 Optional<size_t> Line;
1260 std::unique_ptr<ErrorInfoBase> Err;
1261};
1262
1263/// Concatenate a source file path and/or name with an Error. The resulting
1264/// Error is unchecked.
1265inline Error createFileError(const Twine &F, Error E) {
1266 return FileError::build(F, Optional<size_t>(), std::move(E));
1267}
1268
1269/// Concatenate a source file path and/or name with line number and an Error.
1270/// The resulting Error is unchecked.
1271inline Error createFileError(const Twine &F, size_t Line, Error E) {
1272 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1273}
1274
1275/// Concatenate a source file path and/or name with a std::error_code
1276/// to form an Error object.
1277inline Error createFileError(const Twine &F, std::error_code EC) {
1278 return createFileError(F, errorCodeToError(EC));
1279}
1280
1281/// Concatenate a source file path and/or name with line number and
1282/// std::error_code to form an Error object.
1283inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1284 return createFileError(F, Line, errorCodeToError(EC));
1285}
1286
1287Error createFileError(const Twine &F, ErrorSuccess) = delete;
1288
1289/// Helper for check-and-exit error handling.
1290///
1291/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1292///
1293class ExitOnError {
1294public:
1295 /// Create an error on exit helper.
1296 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1297 : Banner(std::move(Banner)),
1298 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1299
1300 /// Set the banner string for any errors caught by operator().
1301 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1302
1303 /// Set the exit-code mapper function.
1304 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1305 this->GetExitCode = std::move(GetExitCode);
1306 }
1307
1308 /// Check Err. If it's in a failure state log the error(s) and exit.
1309 void operator()(Error Err) const { checkError(std::move(Err)); }
1310
1311 /// Check E. If it's in a success state then return the contained value. If
1312 /// it's in a failure state log the error(s) and exit.
1313 template <typename T> T operator()(Expected<T> &&E) const {
1314 checkError(E.takeError());
1315 return std::move(*E);
1316 }
1317
1318 /// Check E. If it's in a success state then return the contained reference. If
1319 /// it's in a failure state log the error(s) and exit.
1320 template <typename T> T& operator()(Expected<T&> &&E) const {
1321 checkError(E.takeError());
1322 return *E;
1323 }
1324
1325private:
1326 void checkError(Error Err) const {
1327 if (Err) {
1328 int ExitCode = GetExitCode(Err);
1329 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1330 exit(ExitCode);
1331 }
1332 }
1333
1334 std::string Banner;
1335 std::function<int(const Error &)> GetExitCode;
1336};
1337
1338/// Conversion from Error to LLVMErrorRef for C error bindings.
1339inline LLVMErrorRef wrap(Error Err) {
1340 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1341}
1342
1343/// Conversion from LLVMErrorRef to Error for C error bindings.
1344inline Error unwrap(LLVMErrorRef ErrRef) {
1345 return Error(std::unique_ptr<ErrorInfoBase>(
1346 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1347}
1348
1349} // end namespace llvm
1350
1351#endif // LLVM_SUPPORT_ERROR_H