Bug Summary

File:llvm/include/llvm/Bitstream/BitstreamReader.h
Warning:line 221, column 39
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'

Annotated Source Code

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clang -cc1 -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 -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Remarks -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/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-11/lib/clang/11.0.0/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-11~++20200309111110+2c36c23f347/build-llvm/lib/Remarks -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -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-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Remarks/BitstreamRemarkParser.cpp

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/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 = std::string(*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-11~++20200309111110+2c36c23f347/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
432 TmpRemarkBuffer = std::move(*BufferOrErr);
433
434 // Don't try to parse the file if it's empty.
435 if (TmpRemarkBuffer->getBufferSize() == 0)
436 return make_error<EndOfFileError>();
437
438 // Create a separate parser used for parsing the separate file.
439 ParserHelper = BitstreamParserHelper(TmpRemarkBuffer->getBuffer());
440 // Advance and check until we can parse the meta block.
441 if (Error E = advanceToMetaBlock(ParserHelper))
442 return E;
443 // Parse the meta from the separate file.
444 // Note: here we overwrite the BlockInfo with the one from the file. This will
445 // be used to parse the rest of the file.
446 BitstreamMetaParserHelper SeparateMetaHelper(ParserHelper.Stream,
447 ParserHelper.BlockInfo);
448 if (Error E = SeparateMetaHelper.parse())
449 return E;
450
451 uint64_t PreviousContainerVersion = ContainerVersion;
452 if (Error E = processCommonMeta(SeparateMetaHelper))
453 return E;
454
455 if (ContainerType != BitstreamRemarkContainerType::SeparateRemarksFile)
456 return createStringError(
457 std::make_error_code(std::errc::illegal_byte_sequence),
458 "Error while parsing external file's BLOCK_META: wrong container "
459 "type.");
460
461 if (PreviousContainerVersion != ContainerVersion)
462 return createStringError(
463 std::make_error_code(std::errc::illegal_byte_sequence),
464 "Error while parsing external file's BLOCK_META: mismatching versions: "
465 "original meta: %lu, external file meta: %lu.",
466 PreviousContainerVersion, ContainerVersion);
467
468 // Process the meta from the separate file.
469 return processSeparateRemarksFileMeta(SeparateMetaHelper);
470}
471
472Error BitstreamRemarkParser::processStandaloneMeta(
473 BitstreamMetaParserHelper &Helper) {
474 if (Error E = processStrTab(*this, Helper.StrTabBuf))
475 return E;
476 return processRemarkVersion(*this, Helper.RemarkVersion);
477}
478
479Error BitstreamRemarkParser::processSeparateRemarksFileMeta(
480 BitstreamMetaParserHelper &Helper) {
481 return processRemarkVersion(*this, Helper.RemarkVersion);
482}
483
484Error BitstreamRemarkParser::processSeparateRemarksMetaMeta(
485 BitstreamMetaParserHelper &Helper) {
486 if (Error E = processStrTab(*this, Helper.StrTabBuf))
487 return E;
488 return processExternalFilePath(Helper.ExternalFilePath);
489}
490
491Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::parseRemark() {
492 BitstreamRemarkParserHelper RemarkHelper(ParserHelper.Stream);
493 if (Error E = RemarkHelper.parse())
494 return std::move(E);
495
496 return processRemark(RemarkHelper);
497}
498
499Expected<std::unique_ptr<Remark>>
500BitstreamRemarkParser::processRemark(BitstreamRemarkParserHelper &Helper) {
501 std::unique_ptr<Remark> Result = std::make_unique<Remark>();
502 Remark &R = *Result;
503
504 if (StrTab == None)
505 return createStringError(
506 std::make_error_code(std::errc::invalid_argument),
507 "Error while parsing BLOCK_REMARK: missing string table.");
508
509 if (!Helper.Type)
510 return createStringError(
511 std::make_error_code(std::errc::illegal_byte_sequence),
512 "Error while parsing BLOCK_REMARK: missing remark type.");
513
514 // Always >= Type::First since it's unsigned.
515 if (*Helper.Type > static_cast<uint8_t>(Type::Last))
516 return createStringError(
517 std::make_error_code(std::errc::illegal_byte_sequence),
518 "Error while parsing BLOCK_REMARK: unknown remark type.");
519
520 R.RemarkType = static_cast<Type>(*Helper.Type);
521
522 if (!Helper.RemarkNameIdx)
523 return createStringError(
524 std::make_error_code(std::errc::illegal_byte_sequence),
525 "Error while parsing BLOCK_REMARK: missing remark name.");
526
527 if (Expected<StringRef> RemarkName = (*StrTab)[*Helper.RemarkNameIdx])
528 R.RemarkName = *RemarkName;
529 else
530 return RemarkName.takeError();
531
532 if (!Helper.PassNameIdx)
533 return createStringError(
534 std::make_error_code(std::errc::illegal_byte_sequence),
535 "Error while parsing BLOCK_REMARK: missing remark pass.");
536
537 if (Expected<StringRef> PassName = (*StrTab)[*Helper.PassNameIdx])
538 R.PassName = *PassName;
539 else
540 return PassName.takeError();
541
542 if (!Helper.FunctionNameIdx)
543 return createStringError(
544 std::make_error_code(std::errc::illegal_byte_sequence),
545 "Error while parsing BLOCK_REMARK: missing remark function name.");
546 if (Expected<StringRef> FunctionName = (*StrTab)[*Helper.FunctionNameIdx])
547 R.FunctionName = *FunctionName;
548 else
549 return FunctionName.takeError();
550
551 if (Helper.SourceFileNameIdx && Helper.SourceLine && Helper.SourceColumn) {
552 Expected<StringRef> SourceFileName = (*StrTab)[*Helper.SourceFileNameIdx];
553 if (!SourceFileName)
554 return SourceFileName.takeError();
555 R.Loc.emplace();
556 R.Loc->SourceFilePath = *SourceFileName;
557 R.Loc->SourceLine = *Helper.SourceLine;
558 R.Loc->SourceColumn = *Helper.SourceColumn;
559 }
560
561 if (Helper.Hotness)
562 R.Hotness = *Helper.Hotness;
563
564 if (!Helper.Args)
565 return std::move(Result);
566
567 for (const BitstreamRemarkParserHelper::Argument &Arg : *Helper.Args) {
568 if (!Arg.KeyIdx)
569 return createStringError(
570 std::make_error_code(std::errc::illegal_byte_sequence),
571 "Error while parsing BLOCK_REMARK: missing key in remark argument.");
572 if (!Arg.ValueIdx)
573 return createStringError(
574 std::make_error_code(std::errc::illegal_byte_sequence),
575 "Error while parsing BLOCK_REMARK: missing value in remark "
576 "argument.");
577
578 // We have at least a key and a value, create an entry.
579 R.Args.emplace_back();
580
581 if (Expected<StringRef> Key = (*StrTab)[*Arg.KeyIdx])
582 R.Args.back().Key = *Key;
583 else
584 return Key.takeError();
585
586 if (Expected<StringRef> Value = (*StrTab)[*Arg.ValueIdx])
587 R.Args.back().Val = *Value;
588 else
589 return Value.takeError();
590
591 if (Arg.SourceFileNameIdx && Arg.SourceLine && Arg.SourceColumn) {
592 if (Expected<StringRef> SourceFileName =
593 (*StrTab)[*Arg.SourceFileNameIdx]) {
594 R.Args.back().Loc.emplace();
595 R.Args.back().Loc->SourceFilePath = *SourceFileName;
596 R.Args.back().Loc->SourceLine = *Arg.SourceLine;
597 R.Args.back().Loc->SourceColumn = *Arg.SourceColumn;
598 } else
599 return SourceFileName.takeError();
600 }
601 }
602
603 return std::move(Result);
604}

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Bitstream/BitstreamReader.h

1//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This header defines the BitstreamReader class. This class can be used to
10// read an arbitrary bitstream, regardless of its contents.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H
15#define LLVM_BITSTREAM_BITSTREAMREADER_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Bitstream/BitCodes.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/Error.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <climits>
28#include <cstddef>
29#include <cstdint>
30#include <memory>
31#include <string>
32#include <utility>
33#include <vector>
34
35namespace llvm {
36
37/// This class maintains the abbreviations read from a block info block.
38class BitstreamBlockInfo {
39public:
40 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
41 /// describe abbreviations that all blocks of the specified ID inherit.
42 struct BlockInfo {
43 unsigned BlockID = 0;
44 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
45 std::string Name;
46 std::vector<std::pair<unsigned, std::string>> RecordNames;
47 };
48
49private:
50 std::vector<BlockInfo> BlockInfoRecords;
51
52public:
53 /// If there is block info for the specified ID, return it, otherwise return
54 /// null.
55 const BlockInfo *getBlockInfo(unsigned BlockID) const {
56 // Common case, the most recent entry matches BlockID.
57 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
58 return &BlockInfoRecords.back();
59
60 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
61 i != e; ++i)
62 if (BlockInfoRecords[i].BlockID == BlockID)
63 return &BlockInfoRecords[i];
64 return nullptr;
65 }
66
67 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
68 if (const BlockInfo *BI = getBlockInfo(BlockID))
69 return *const_cast<BlockInfo*>(BI);
70
71 // Otherwise, add a new record.
72 BlockInfoRecords.emplace_back();
73 BlockInfoRecords.back().BlockID = BlockID;
74 return BlockInfoRecords.back();
75 }
76};
77
78/// This represents a position within a bitstream. There may be multiple
79/// independent cursors reading within one bitstream, each maintaining their
80/// own local state.
81class SimpleBitstreamCursor {
82 ArrayRef<uint8_t> BitcodeBytes;
83 size_t NextChar = 0;
84
85public:
86 /// This is the current data we have pulled from the stream but have not
87 /// returned to the client. This is specifically and intentionally defined to
88 /// follow the word size of the host machine for efficiency. We use word_t in
89 /// places that are aware of this to make it perfectly explicit what is going
90 /// on.
91 using word_t = size_t;
92
93private:
94 word_t CurWord = 0;
95
96 /// This is the number of bits in CurWord that are valid. This is always from
97 /// [0...bits_of(size_t)-1] inclusive.
98 unsigned BitsInCurWord = 0;
99
100public:
101 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
102
103 SimpleBitstreamCursor() = default;
104 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
105 : BitcodeBytes(BitcodeBytes) {}
106 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
107 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
108 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
109 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
110
111 bool canSkipToPos(size_t pos) const {
112 // pos can be skipped to if it is a valid address or one byte past the end.
113 return pos <= BitcodeBytes.size();
114 }
115
116 bool AtEndOfStream() {
117 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
118 }
119
120 /// Return the bit # of the bit we are reading.
121 uint64_t GetCurrentBitNo() const {
122 return NextChar*CHAR_BIT8 - BitsInCurWord;
123 }
124
125 // Return the byte # of the current bit.
126 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
127
128 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
129
130 /// Reset the stream to the specified bit number.
131 Error JumpToBit(uint64_t BitNo) {
132 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
133 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
134 assert(canSkipToPos(ByteNo) && "Invalid location")((canSkipToPos(ByteNo) && "Invalid location") ? static_cast
<void> (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 134, __PRETTY_FUNCTION__))
;
135
136 // Move the cursor to the right word.
137 NextChar = ByteNo;
138 BitsInCurWord = 0;
139
140 // Skip over any bits that are already consumed.
141 if (WordBitNo) {
142 if (Expected<word_t> Res = Read(WordBitNo))
143 return Error::success();
144 else
145 return Res.takeError();
146 }
147
148 return Error::success();
149 }
150
151 /// Get a pointer into the bitstream at the specified byte offset.
152 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
153 return BitcodeBytes.data() + ByteNo;
154 }
155
156 /// Get a pointer into the bitstream at the specified bit offset.
157 ///
158 /// The bit offset must be on a byte boundary.
159 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
160 assert(!(BitNo % 8) && "Expected bit on byte boundary")((!(BitNo % 8) && "Expected bit on byte boundary") ? static_cast
<void> (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 160, __PRETTY_FUNCTION__))
;
161 return getPointerToByte(BitNo / 8, NumBytes);
162 }
163
164 Error fillCurWord() {
165 if (NextChar >= BitcodeBytes.size())
166 return createStringError(std::errc::io_error,
167 "Unexpected end of file reading %u of %u bytes",
168 NextChar, BitcodeBytes.size());
169
170 // Read the next word from the stream.
171 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
172 unsigned BytesRead;
173 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
174 BytesRead = sizeof(word_t);
175 CurWord =
176 support::endian::read<word_t, support::little, support::unaligned>(
177 NextCharPtr);
178 } else {
179 // Short read.
180 BytesRead = BitcodeBytes.size() - NextChar;
181 CurWord = 0;
182 for (unsigned B = 0; B != BytesRead; ++B)
183 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
184 }
185 NextChar += BytesRead;
186 BitsInCurWord = BytesRead * 8;
187 return Error::success();
188 }
189
190 Expected<word_t> Read(unsigned NumBits) {
191 static const unsigned BitsInWord = MaxChunkSize;
192
193 assert(NumBits && NumBits <= BitsInWord &&((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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __PRETTY_FUNCTION__))
4
'?' condition is true
194 "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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __PRETTY_FUNCTION__))
;
195
196 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
5
'?' condition is true
197
198 // If the field is fully contained by CurWord, return it quickly.
199 if (BitsInCurWord >= NumBits) {
6
Assuming 'NumBits' is > field 'BitsInCurWord'
7
Taking false branch
200 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
201
202 // Use a mask to avoid undefined behavior.
203 CurWord >>= (NumBits & Mask);
204
205 BitsInCurWord -= NumBits;
206 return R;
207 }
208
209 word_t R = BitsInCurWord ? CurWord : 0;
8
Assuming field 'BitsInCurWord' is not equal to 0
9
'?' condition is true
210 unsigned BitsLeft = NumBits - BitsInCurWord;
211
212 if (Error fillResult = fillCurWord())
10
Calling 'Error::operator bool'
12
Returning from 'Error::operator bool'
13
Taking false branch
213 return std::move(fillResult);
214
215 // If we run out of data, abort.
216 if (BitsLeft > BitsInCurWord)
14
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
15
Taking false branch
217 return createStringError(std::errc::io_error,
218 "Unexpected end of file reading %u of %u bits",
219 BitsInCurWord, BitsLeft);
220
221 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
16
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
222
223 // Use a mask to avoid undefined behavior.
224 CurWord >>= (BitsLeft & Mask);
225
226 BitsInCurWord -= BitsLeft;
227
228 R |= R2 << (NumBits - BitsLeft);
229
230 return R;
231 }
232
233 Expected<uint32_t> ReadVBR(unsigned NumBits) {
234 Expected<unsigned> MaybeRead = Read(NumBits);
235 if (!MaybeRead)
236 return MaybeRead;
237 uint32_t Piece = MaybeRead.get();
238
239 if ((Piece & (1U << (NumBits-1))) == 0)
240 return Piece;
241
242 uint32_t Result = 0;
243 unsigned NextBit = 0;
244 while (true) {
245 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
246
247 if ((Piece & (1U << (NumBits-1))) == 0)
248 return Result;
249
250 NextBit += NumBits-1;
251 MaybeRead = Read(NumBits);
252 if (!MaybeRead)
253 return MaybeRead;
254 Piece = MaybeRead.get();
255 }
256 }
257
258 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
259 // the VBR must still be <= 32 bits though.
260 Expected<uint64_t> ReadVBR64(unsigned NumBits) {
261 Expected<uint64_t> MaybeRead = Read(NumBits);
262 if (!MaybeRead)
263 return MaybeRead;
264 uint32_t Piece = MaybeRead.get();
265
266 if ((Piece & (1U << (NumBits-1))) == 0)
267 return uint64_t(Piece);
268
269 uint64_t Result = 0;
270 unsigned NextBit = 0;
271 while (true) {
272 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
273
274 if ((Piece & (1U << (NumBits-1))) == 0)
275 return Result;
276
277 NextBit += NumBits-1;
278 MaybeRead = Read(NumBits);
279 if (!MaybeRead)
280 return MaybeRead;
281 Piece = MaybeRead.get();
282 }
283 }
284
285 void SkipToFourByteBoundary() {
286 // If word_t is 64-bits and if we've read less than 32 bits, just dump
287 // the bits we have up to the next 32-bit boundary.
288 if (sizeof(word_t) > 4 &&
289 BitsInCurWord >= 32) {
290 CurWord >>= BitsInCurWord-32;
291 BitsInCurWord = 32;
292 return;
293 }
294
295 BitsInCurWord = 0;
296 }
297
298 /// Return the size of the stream in bytes.
299 size_t SizeInBytes() const { return BitcodeBytes.size(); }
300
301 /// Skip to the end of the file.
302 void skipToEnd() { NextChar = BitcodeBytes.size(); }
303};
304
305/// When advancing through a bitstream cursor, each advance can discover a few
306/// different kinds of entries:
307struct BitstreamEntry {
308 enum {
309 Error, // Malformed bitcode was found.
310 EndBlock, // We've reached the end of the current block, (or the end of the
311 // file, which is treated like a series of EndBlock records.
312 SubBlock, // This is the start of a new subblock of a specific ID.
313 Record // This is a record with a specific AbbrevID.
314 } Kind;
315
316 unsigned ID;
317
318 static BitstreamEntry getError() {
319 BitstreamEntry E; E.Kind = Error; return E;
320 }
321
322 static BitstreamEntry getEndBlock() {
323 BitstreamEntry E; E.Kind = EndBlock; return E;
324 }
325
326 static BitstreamEntry getSubBlock(unsigned ID) {
327 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
328 }
329
330 static BitstreamEntry getRecord(unsigned AbbrevID) {
331 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
332 }
333};
334
335/// This represents a position within a bitcode file, implemented on top of a
336/// SimpleBitstreamCursor.
337///
338/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
339/// be passed by value.
340class BitstreamCursor : SimpleBitstreamCursor {
341 // This is the declared size of code values used for the current block, in
342 // bits.
343 unsigned CurCodeSize = 2;
344
345 /// Abbrevs installed at in this block.
346 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
347
348 struct Block {
349 unsigned PrevCodeSize;
350 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
351
352 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
353 };
354
355 /// This tracks the codesize of parent blocks.
356 SmallVector<Block, 8> BlockScope;
357
358 BitstreamBlockInfo *BlockInfo = nullptr;
359
360public:
361 static const size_t MaxChunkSize = sizeof(word_t) * 8;
362
363 BitstreamCursor() = default;
364 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
365 : SimpleBitstreamCursor(BitcodeBytes) {}
366 explicit BitstreamCursor(StringRef BitcodeBytes)
367 : SimpleBitstreamCursor(BitcodeBytes) {}
368 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
369 : SimpleBitstreamCursor(BitcodeBytes) {}
370
371 using SimpleBitstreamCursor::AtEndOfStream;
372 using SimpleBitstreamCursor::canSkipToPos;
373 using SimpleBitstreamCursor::fillCurWord;
374 using SimpleBitstreamCursor::getBitcodeBytes;
375 using SimpleBitstreamCursor::GetCurrentBitNo;
376 using SimpleBitstreamCursor::getCurrentByteNo;
377 using SimpleBitstreamCursor::getPointerToByte;
378 using SimpleBitstreamCursor::JumpToBit;
379 using SimpleBitstreamCursor::Read;
380 using SimpleBitstreamCursor::ReadVBR;
381 using SimpleBitstreamCursor::ReadVBR64;
382 using SimpleBitstreamCursor::SizeInBytes;
383 using SimpleBitstreamCursor::skipToEnd;
384
385 /// Return the number of bits used to encode an abbrev #.
386 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
387
388 /// Flags that modify the behavior of advance().
389 enum {
390 /// If this flag is used, the advance() method does not automatically pop
391 /// the block scope when the end of a block is reached.
392 AF_DontPopBlockAtEnd = 1,
393
394 /// If this flag is used, abbrev entries are returned just like normal
395 /// records.
396 AF_DontAutoprocessAbbrevs = 2
397 };
398
399 /// Advance the current bitstream, returning the next entry in the stream.
400 Expected<BitstreamEntry> advance(unsigned Flags = 0) {
401 while (true) {
402 if (AtEndOfStream())
403 return BitstreamEntry::getError();
404
405 Expected<unsigned> MaybeCode = ReadCode();
406 if (!MaybeCode)
407 return MaybeCode.takeError();
408 unsigned Code = MaybeCode.get();
409
410 if (Code == bitc::END_BLOCK) {
411 // Pop the end of the block unless Flags tells us not to.
412 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
413 return BitstreamEntry::getError();
414 return BitstreamEntry::getEndBlock();
415 }
416
417 if (Code == bitc::ENTER_SUBBLOCK) {
418 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID())
419 return BitstreamEntry::getSubBlock(MaybeSubBlock.get());
420 else
421 return MaybeSubBlock.takeError();
422 }
423
424 if (Code == bitc::DEFINE_ABBREV &&
425 !(Flags & AF_DontAutoprocessAbbrevs)) {
426 // We read and accumulate abbrev's, the client can't do anything with
427 // them anyway.
428 if (Error Err = ReadAbbrevRecord())
429 return std::move(Err);
430 continue;
431 }
432
433 return BitstreamEntry::getRecord(Code);
434 }
435 }
436
437 /// This is a convenience function for clients that don't expect any
438 /// subblocks. This just skips over them automatically.
439 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) {
440 while (true) {
441 // If we found a normal entry, return it.
442 Expected<BitstreamEntry> MaybeEntry = advance(Flags);
443 if (!MaybeEntry)
444 return MaybeEntry;
445 BitstreamEntry Entry = MaybeEntry.get();
446
447 if (Entry.Kind != BitstreamEntry::SubBlock)
448 return Entry;
449
450 // If we found a sub-block, just skip over it and check the next entry.
451 if (Error Err = SkipBlock())
452 return std::move(Err);
453 }
454 }
455
456 Expected<unsigned> ReadCode() { return Read(CurCodeSize); }
457
458 // Block header:
459 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
460
461 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
462 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); }
463
464 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
465 /// of this block.
466 Error SkipBlock() {
467 // Read and ignore the codelen value.
468 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth))
469 ; // Since we are skipping this block, we don't care what code widths are
470 // used inside of it.
471 else
472 return Res.takeError();
473
474 SkipToFourByteBoundary();
475 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth);
476 if (!MaybeNum)
477 return MaybeNum.takeError();
478 size_t NumFourBytes = MaybeNum.get();
479
480 // Check that the block wasn't partially defined, and that the offset isn't
481 // bogus.
482 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8;
483 if (AtEndOfStream())
484 return createStringError(std::errc::illegal_byte_sequence,
485 "can't skip block: already at end of stream");
486 if (!canSkipToPos(SkipTo / 8))
487 return createStringError(std::errc::illegal_byte_sequence,
488 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo,
489 GetCurrentBitNo());
490
491 if (Error Res = JumpToBit(SkipTo))
492 return Res;
493
494 return Error::success();
495 }
496
497 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
498 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
499
500 bool ReadBlockEnd() {
501 if (BlockScope.empty()) return true;
502
503 // Block tail:
504 // [END_BLOCK, <align4bytes>]
505 SkipToFourByteBoundary();
506
507 popBlockScope();
508 return false;
509 }
510
511private:
512 void popBlockScope() {
513 CurCodeSize = BlockScope.back().PrevCodeSize;
514
515 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
516 BlockScope.pop_back();
517 }
518
519 //===--------------------------------------------------------------------===//
520 // Record Processing
521 //===--------------------------------------------------------------------===//
522
523public:
524 /// Return the abbreviation for the specified AbbrevId.
525 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
526 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
527 if (AbbrevNo >= CurAbbrevs.size())
528 report_fatal_error("Invalid abbrev number");
529 return CurAbbrevs[AbbrevNo].get();
530 }
531
532 /// Read the current record and discard it, returning the code for the record.
533 Expected<unsigned> skipRecord(unsigned AbbrevID);
534
535 Expected<unsigned> readRecord(unsigned AbbrevID,
536 SmallVectorImpl<uint64_t> &Vals,
537 StringRef *Blob = nullptr);
538
539 //===--------------------------------------------------------------------===//
540 // Abbrev Processing
541 //===--------------------------------------------------------------------===//
542 Error ReadAbbrevRecord();
543
544 /// Read and return a block info block from the bitstream. If an error was
545 /// encountered, return None.
546 ///
547 /// \param ReadBlockInfoNames Whether to read block/record name information in
548 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
549 Expected<Optional<BitstreamBlockInfo>>
550 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
551
552 /// Set the block info to be used by this BitstreamCursor to interpret
553 /// abbreviated records.
554 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
555};
556
557} // end llvm namespace
558
559#endif // LLVM_BITSTREAM_BITSTREAMREADER_H

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
11
Returning zero, which participates in a condition later
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 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-11~++20200309111110+2c36c23f347/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-11~++20200309111110+2c36c23f347/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<std::remove_reference_t<T>>;
440
441 using error_type = std::unique_ptr<ErrorInfoBase>;
442
443public:
444 using storage_type = std::conditional_t<isRef, wrap, T>;
445 using value_type = T;
446
447private:
448 using reference = std::remove_reference_t<T> &;
449 using const_reference = const std::remove_reference_t<T> &;
450 using pointer = std::remove_reference_t<T> *;
451 using const_pointer = const std::remove_reference_t<T> *;
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-11~++20200309111110+2c36c23f347/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 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
476 : HasError(false)
477#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
478 // Expected is unchecked upon construction in Debug builds.
479 ,
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(
493 Expected<OtherT> &&Other,
494 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = 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 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
504 moveConstruct(std::move(Other));
505 }
506
507 /// Move-assign from another Expected<T>.
508 Expected &operator=(Expected &&Other) {
509 moveAssign(std::move(Other));
510 return *this;
511 }
512
513 /// Destroy an Expected<T>.
514 ~Expected() {
515 assertIsChecked();
516 if (!HasError)
517 getStorage()->~storage_type();
518 else
519 getErrorStorage()->~error_type();
520 }
521
522 /// Return false if there is an error.
523 explicit operator bool() {
524#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
525 Unchecked = HasError;
526#endif
527 return !HasError;
528 }
529
530 /// Returns a reference to the stored T value.
531 reference get() {
532 assertIsChecked();
533 return *getStorage();
534 }
535
536 /// Returns a const reference to the stored T value.
537 const_reference get() const {
538 assertIsChecked();
539 return const_cast<Expected<T> *>(this)->get();
540 }
541
542 /// Check that this Expected<T> is an error of type ErrT.
543 template <typename ErrT> bool errorIsA() const {
544 return HasError && (*getErrorStorage())->template isA<ErrT>();
545 }
546
547 /// Take ownership of the stored error.
548 /// After calling this the Expected<T> is in an indeterminate state that can
549 /// only be safely destructed. No further calls (beside the destructor) should
550 /// be made on the Expected<T> value.
551 Error takeError() {
552#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
553 Unchecked = false;
554#endif
555 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
556 }
557
558 /// Returns a pointer to the stored T value.
559 pointer operator->() {
560 assertIsChecked();
561 return toPointer(getStorage());
562 }
563
564 /// Returns a const pointer to the stored T value.
565 const_pointer operator->() const {
566 assertIsChecked();
567 return toPointer(getStorage());
568 }
569
570 /// Returns a reference to the stored T value.
571 reference operator*() {
572 assertIsChecked();
573 return *getStorage();
574 }
575
576 /// Returns a const reference to the stored T value.
577 const_reference operator*() const {
578 assertIsChecked();
579 return *getStorage();
580 }
581
582private:
583 template <class T1>
584 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
585 return &a == &b;
586 }
587
588 template <class T1, class T2>
589 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
590 return false;
591 }
592
593 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
594 HasError = Other.HasError;
595#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
596 Unchecked = true;
597 Other.Unchecked = false;
598#endif
599
600 if (!HasError)
601 new (getStorage()) storage_type(std::move(*Other.getStorage()));
602 else
603 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
604 }
605
606 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
607 assertIsChecked();
608
609 if (compareThisIfSameType(*this, Other))
610 return;
611
612 this->~Expected();
613 new (this) Expected(std::move(Other));
614 }
615
616 pointer toPointer(pointer Val) { return Val; }
617
618 const_pointer toPointer(const_pointer Val) const { return Val; }
619
620 pointer toPointer(wrap *Val) { return &Val->get(); }
621
622 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
623
624 storage_type *getStorage() {
625 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 625, __PRETTY_FUNCTION__))
;
626 return reinterpret_cast<storage_type *>(TStorage.buffer);
627 }
628
629 const storage_type *getStorage() const {
630 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 630, __PRETTY_FUNCTION__))
;
631 return reinterpret_cast<const storage_type *>(TStorage.buffer);
632 }
633
634 error_type *getErrorStorage() {
635 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 635, __PRETTY_FUNCTION__))
;
636 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
637 }
638
639 const error_type *getErrorStorage() const {
640 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 640, __PRETTY_FUNCTION__))
;
641 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
642 }
643
644 // Used by ExpectedAsOutParameter to reset the checked flag.
645 void setUnchecked() {
646#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
647 Unchecked = true;
648#endif
649 }
650
651#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
652 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
653 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
654 void fatalUncheckedExpected() const {
655 dbgs() << "Expected<T> must be checked before access or destruction.\n";
656 if (HasError) {
657 dbgs() << "Unchecked Expected<T> contained error:\n";
658 (*getErrorStorage())->log(dbgs());
659 } else
660 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
661 "values in success mode must still be checked prior to being "
662 "destroyed).\n";
663 abort();
664 }
665#endif
666
667 void assertIsChecked() {
668#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
669 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
670 fatalUncheckedExpected();
671#endif
672 }
673
674 union {
675 AlignedCharArrayUnion<storage_type> TStorage;
676 AlignedCharArrayUnion<error_type> ErrorStorage;
677 };
678 bool HasError : 1;
679#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
680 bool Unchecked : 1;
681#endif
682};
683
684/// Report a serious error, calling any installed error handler. See
685/// ErrorHandling.h.
686LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
687 bool gen_crash_diag = true);
688
689/// Report a fatal error if Err is a failure value.
690///
691/// This function can be used to wrap calls to fallible functions ONLY when it
692/// is known that the Error will always be a success value. E.g.
693///
694/// @code{.cpp}
695/// // foo only attempts the fallible operation if DoFallibleOperation is
696/// // true. If DoFallibleOperation is false then foo always returns
697/// // Error::success().
698/// Error foo(bool DoFallibleOperation);
699///
700/// cantFail(foo(false));
701/// @endcode
702inline void cantFail(Error Err, const char *Msg = nullptr) {
703 if (Err) {
704 if (!Msg)
705 Msg = "Failure value returned from cantFail wrapped call";
706#ifndef NDEBUG
707 std::string Str;
708 raw_string_ostream OS(Str);
709 OS << Msg << "\n" << Err;
710 Msg = OS.str().c_str();
711#endif
712 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 712)
;
713 }
714}
715
716/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
717/// returns the contained value.
718///
719/// This function can be used to wrap calls to fallible functions ONLY when it
720/// is known that the Error will always be a success value. E.g.
721///
722/// @code{.cpp}
723/// // foo only attempts the fallible operation if DoFallibleOperation is
724/// // true. If DoFallibleOperation is false then foo always returns an int.
725/// Expected<int> foo(bool DoFallibleOperation);
726///
727/// int X = cantFail(foo(false));
728/// @endcode
729template <typename T>
730T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
731 if (ValOrErr)
732 return std::move(*ValOrErr);
733 else {
734 if (!Msg)
735 Msg = "Failure value returned from cantFail wrapped call";
736#ifndef NDEBUG
737 std::string Str;
738 raw_string_ostream OS(Str);
739 auto E = ValOrErr.takeError();
740 OS << Msg << "\n" << E;
741 Msg = OS.str().c_str();
742#endif
743 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 743)
;
744 }
745}
746
747/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
748/// returns the contained reference.
749///
750/// This function can be used to wrap calls to fallible functions ONLY when it
751/// is known that the Error will always be a success value. E.g.
752///
753/// @code{.cpp}
754/// // foo only attempts the fallible operation if DoFallibleOperation is
755/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
756/// Expected<Bar&> foo(bool DoFallibleOperation);
757///
758/// Bar &X = cantFail(foo(false));
759/// @endcode
760template <typename T>
761T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
762 if (ValOrErr)
763 return *ValOrErr;
764 else {
765 if (!Msg)
766 Msg = "Failure value returned from cantFail wrapped call";
767#ifndef NDEBUG
768 std::string Str;
769 raw_string_ostream OS(Str);
770 auto E = ValOrErr.takeError();
771 OS << Msg << "\n" << E;
772 Msg = OS.str().c_str();
773#endif
774 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 774)
;
775 }
776}
777
778/// Helper for testing applicability of, and applying, handlers for
779/// ErrorInfo types.
780template <typename HandlerT>
781class ErrorHandlerTraits
782 : public ErrorHandlerTraits<decltype(
783 &std::remove_reference<HandlerT>::type::operator())> {};
784
785// Specialization functions of the form 'Error (const ErrT&)'.
786template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
787public:
788 static bool appliesTo(const ErrorInfoBase &E) {
789 return E.template isA<ErrT>();
790 }
791
792 template <typename HandlerT>
793 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
794 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 794, __PRETTY_FUNCTION__))
;
795 return H(static_cast<ErrT &>(*E));
796 }
797};
798
799// Specialization functions of the form 'void (const ErrT&)'.
800template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
801public:
802 static bool appliesTo(const ErrorInfoBase &E) {
803 return E.template isA<ErrT>();
804 }
805
806 template <typename HandlerT>
807 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
808 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 808, __PRETTY_FUNCTION__))
;
809 H(static_cast<ErrT &>(*E));
810 return Error::success();
811 }
812};
813
814/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
815template <typename ErrT>
816class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
817public:
818 static bool appliesTo(const ErrorInfoBase &E) {
819 return E.template isA<ErrT>();
820 }
821
822 template <typename HandlerT>
823 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
824 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 824, __PRETTY_FUNCTION__))
;
825 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
826 return H(std::move(SubE));
827 }
828};
829
830/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
831template <typename ErrT>
832class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
833public:
834 static bool appliesTo(const ErrorInfoBase &E) {
835 return E.template isA<ErrT>();
836 }
837
838 template <typename HandlerT>
839 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
840 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 840, __PRETTY_FUNCTION__))
;
841 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
842 H(std::move(SubE));
843 return Error::success();
844 }
845};
846
847// Specialization for member functions of the form 'RetT (const ErrT&)'.
848template <typename C, typename RetT, typename ErrT>
849class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
850 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
851
852// Specialization for member functions of the form 'RetT (const ErrT&) const'.
853template <typename C, typename RetT, typename ErrT>
854class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
855 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
856
857// Specialization for member functions of the form 'RetT (const ErrT&)'.
858template <typename C, typename RetT, typename ErrT>
859class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
860 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
861
862// Specialization for member functions of the form 'RetT (const ErrT&) const'.
863template <typename C, typename RetT, typename ErrT>
864class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
865 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
866
867/// Specialization for member functions of the form
868/// 'RetT (std::unique_ptr<ErrT>)'.
869template <typename C, typename RetT, typename ErrT>
870class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
871 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
872
873/// Specialization for member functions of the form
874/// 'RetT (std::unique_ptr<ErrT>) const'.
875template <typename C, typename RetT, typename ErrT>
876class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
877 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
878
879inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
880 return Error(std::move(Payload));
881}
882
883template <typename HandlerT, typename... HandlerTs>
884Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
885 HandlerT &&Handler, HandlerTs &&... Handlers) {
886 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
887 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
888 std::move(Payload));
889 return handleErrorImpl(std::move(Payload),
890 std::forward<HandlerTs>(Handlers)...);
891}
892
893/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
894/// unhandled errors (or Errors returned by handlers) are re-concatenated and
895/// returned.
896/// Because this function returns an error, its result must also be checked
897/// or returned. If you intend to handle all errors use handleAllErrors
898/// (which returns void, and will abort() on unhandled errors) instead.
899template <typename... HandlerTs>
900Error handleErrors(Error E, HandlerTs &&... Hs) {
901 if (!E)
902 return Error::success();
903
904 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
905
906 if (Payload->isA<ErrorList>()) {
907 ErrorList &List = static_cast<ErrorList &>(*Payload);
908 Error R;
909 for (auto &P : List.Payloads)
910 R = ErrorList::join(
911 std::move(R),
912 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
913 return R;
914 }
915
916 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
917}
918
919/// Behaves the same as handleErrors, except that by contract all errors
920/// *must* be handled by the given handlers (i.e. there must be no remaining
921/// errors after running the handlers, or llvm_unreachable is called).
922template <typename... HandlerTs>
923void handleAllErrors(Error E, HandlerTs &&... Handlers) {
924 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
925}
926
927/// Check that E is a non-error, then drop it.
928/// If E is an error, llvm_unreachable will be called.
929inline void handleAllErrors(Error E) {
930 cantFail(std::move(E));
931}
932
933/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
934///
935/// If the incoming value is a success value it is returned unmodified. If it
936/// is a failure value then it the contained error is passed to handleErrors.
937/// If handleErrors is able to handle the error then the RecoveryPath functor
938/// is called to supply the final result. If handleErrors is not able to
939/// handle all errors then the unhandled errors are returned.
940///
941/// This utility enables the follow pattern:
942///
943/// @code{.cpp}
944/// enum FooStrategy { Aggressive, Conservative };
945/// Expected<Foo> foo(FooStrategy S);
946///
947/// auto ResultOrErr =
948/// handleExpected(
949/// foo(Aggressive),
950/// []() { return foo(Conservative); },
951/// [](AggressiveStrategyError&) {
952/// // Implicitly conusme this - we'll recover by using a conservative
953/// // strategy.
954/// });
955///
956/// @endcode
957template <typename T, typename RecoveryFtor, typename... HandlerTs>
958Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
959 HandlerTs &&... Handlers) {
960 if (ValOrErr)
961 return ValOrErr;
962
963 if (auto Err = handleErrors(ValOrErr.takeError(),
964 std::forward<HandlerTs>(Handlers)...))
965 return std::move(Err);
966
967 return RecoveryPath();
968}
969
970/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
971/// will be printed before the first one is logged. A newline will be printed
972/// after each error.
973///
974/// This function is compatible with the helpers from Support/WithColor.h. You
975/// can pass any of them as the OS. Please consider using them instead of
976/// including 'error: ' in the ErrorBanner.
977///
978/// This is useful in the base level of your program to allow clean termination
979/// (allowing clean deallocation of resources, etc.), while reporting error
980/// information to the user.
981void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
982
983/// Write all error messages (if any) in E to a string. The newline character
984/// is used to separate error messages.
985inline std::string toString(Error E) {
986 SmallVector<std::string, 2> Errors;
987 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
988 Errors.push_back(EI.message());
989 });
990 return join(Errors.begin(), Errors.end(), "\n");
991}
992
993/// Consume a Error without doing anything. This method should be used
994/// only where an error can be considered a reasonable and expected return
995/// value.
996///
997/// Uses of this method are potentially indicative of design problems: If it's
998/// legitimate to do nothing while processing an "error", the error-producer
999/// might be more clearly refactored to return an Optional<T>.
1000inline void consumeError(Error Err) {
1001 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1002}
1003
1004/// Convert an Expected to an Optional without doing anything. This method
1005/// should be used only where an error can be considered a reasonable and
1006/// expected return value.
1007///
1008/// Uses of this method are potentially indicative of problems: perhaps the
1009/// error should be propagated further, or the error-producer should just
1010/// return an Optional in the first place.
1011template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1012 if (E)
1013 return std::move(*E);
1014 consumeError(E.takeError());
1015 return None;
1016}
1017
1018/// Helper for converting an Error to a bool.
1019///
1020/// This method returns true if Err is in an error state, or false if it is
1021/// in a success state. Puts Err in a checked state in both cases (unlike
1022/// Error::operator bool(), which only does this for success states).
1023inline bool errorToBool(Error Err) {
1024 bool IsError = static_cast<bool>(Err);
1025 if (IsError)
1026 consumeError(std::move(Err));
1027 return IsError;
1028}
1029
1030/// Helper for Errors used as out-parameters.
1031///
1032/// This helper is for use with the Error-as-out-parameter idiom, where an error
1033/// is passed to a function or method by reference, rather than being returned.
1034/// In such cases it is helpful to set the checked bit on entry to the function
1035/// so that the error can be written to (unchecked Errors abort on assignment)
1036/// and clear the checked bit on exit so that clients cannot accidentally forget
1037/// to check the result. This helper performs these actions automatically using
1038/// RAII:
1039///
1040/// @code{.cpp}
1041/// Result foo(Error &Err) {
1042/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1043/// // <body of foo>
1044/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1045/// }
1046/// @endcode
1047///
1048/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1049/// used with optional Errors (Error pointers that are allowed to be null). If
1050/// ErrorAsOutParameter took an Error reference, an instance would have to be
1051/// created inside every condition that verified that Error was non-null. By
1052/// taking an Error pointer we can just create one instance at the top of the
1053/// function.
1054class ErrorAsOutParameter {
1055public:
1056 ErrorAsOutParameter(Error *Err) : Err(Err) {
1057 // Raise the checked bit if Err is success.
1058 if (Err)
1059 (void)!!*Err;
1060 }
1061
1062 ~ErrorAsOutParameter() {
1063 // Clear the checked bit.
1064 if (Err && !*Err)
1065 *Err = Error::success();
1066 }
1067
1068private:
1069 Error *Err;
1070};
1071
1072/// Helper for Expected<T>s used as out-parameters.
1073///
1074/// See ErrorAsOutParameter.
1075template <typename T>
1076class ExpectedAsOutParameter {
1077public:
1078 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1079 : ValOrErr(ValOrErr) {
1080 if (ValOrErr)
1081 (void)!!*ValOrErr;
1082 }
1083
1084 ~ExpectedAsOutParameter() {
1085 if (ValOrErr)
1086 ValOrErr->setUnchecked();
1087 }
1088
1089private:
1090 Expected<T> *ValOrErr;
1091};
1092
1093/// This class wraps a std::error_code in a Error.
1094///
1095/// This is useful if you're writing an interface that returns a Error
1096/// (or Expected) and you want to call code that still returns
1097/// std::error_codes.
1098class ECError : public ErrorInfo<ECError> {
1099 friend Error errorCodeToError(std::error_code);
1100
1101 virtual void anchor() override;
1102
1103public:
1104 void setErrorCode(std::error_code EC) { this->EC = EC; }
1105 std::error_code convertToErrorCode() const override { return EC; }
1106 void log(raw_ostream &OS) const override { OS << EC.message(); }
1107
1108 // Used by ErrorInfo::classID.
1109 static char ID;
1110
1111protected:
1112 ECError() = default;
1113 ECError(std::error_code EC) : EC(EC) {}
1114
1115 std::error_code EC;
1116};
1117
1118/// The value returned by this function can be returned from convertToErrorCode
1119/// for Error values where no sensible translation to std::error_code exists.
1120/// It should only be used in this situation, and should never be used where a
1121/// sensible conversion to std::error_code is available, as attempts to convert
1122/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1123///error to try to convert such a value).
1124std::error_code inconvertibleErrorCode();
1125
1126/// Helper for converting an std::error_code to a Error.
1127Error errorCodeToError(std::error_code EC);
1128
1129/// Helper for converting an ECError to a std::error_code.
1130///
1131/// This method requires that Err be Error() or an ECError, otherwise it
1132/// will trigger a call to abort().
1133std::error_code errorToErrorCode(Error Err);
1134
1135/// Convert an ErrorOr<T> to an Expected<T>.
1136template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1137 if (auto EC = EO.getError())
1138 return errorCodeToError(EC);
1139 return std::move(*EO);
1140}
1141
1142/// Convert an Expected<T> to an ErrorOr<T>.
1143template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1144 if (auto Err = E.takeError())
1145 return errorToErrorCode(std::move(Err));
1146 return std::move(*E);
1147}
1148
1149/// This class wraps a string in an Error.
1150///
1151/// StringError is useful in cases where the client is not expected to be able
1152/// to consume the specific error message programmatically (for example, if the
1153/// error message is to be presented to the user).
1154///
1155/// StringError can also be used when additional information is to be printed
1156/// along with a error_code message. Depending on the constructor called, this
1157/// class can either display:
1158/// 1. the error_code message (ECError behavior)
1159/// 2. a string
1160/// 3. the error_code message and a string
1161///
1162/// These behaviors are useful when subtyping is required; for example, when a
1163/// specific library needs an explicit error type. In the example below,
1164/// PDBError is derived from StringError:
1165///
1166/// @code{.cpp}
1167/// Expected<int> foo() {
1168/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1169/// "Additional information");
1170/// }
1171/// @endcode
1172///
1173class StringError : public ErrorInfo<StringError> {
1174public:
1175 static char ID;
1176
1177 // Prints EC + S and converts to EC
1178 StringError(std::error_code EC, const Twine &S = Twine());
1179
1180 // Prints S and converts to EC
1181 StringError(const Twine &S, std::error_code EC);
1182
1183 void log(raw_ostream &OS) const override;
1184 std::error_code convertToErrorCode() const override;
1185
1186 const std::string &getMessage() const { return Msg; }
1187
1188private:
1189 std::string Msg;
1190 std::error_code EC;
1191 const bool PrintMsgOnly = false;
1192};
1193
1194/// Create formatted StringError object.
1195template <typename... Ts>
1196inline Error createStringError(std::error_code EC, char const *Fmt,
1197 const Ts &... Vals) {
1198 std::string Buffer;
1199 raw_string_ostream Stream(Buffer);
1200 Stream << format(Fmt, Vals...);
1201 return make_error<StringError>(Stream.str(), EC);
1202}
1203
1204Error createStringError(std::error_code EC, char const *Msg);
1205
1206inline Error createStringError(std::error_code EC, const Twine &S) {
1207 return createStringError(EC, S.str().c_str());
1208}
1209
1210template <typename... Ts>
1211inline Error createStringError(std::errc EC, char const *Fmt,
1212 const Ts &... Vals) {
1213 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1214}
1215
1216/// This class wraps a filename and another Error.
1217///
1218/// In some cases, an error needs to live along a 'source' name, in order to
1219/// show more detailed information to the user.
1220class FileError final : public ErrorInfo<FileError> {
1221
1222 friend Error createFileError(const Twine &, Error);
1223 friend Error createFileError(const Twine &, size_t, Error);
1224
1225public:
1226 void log(raw_ostream &OS) const override {
1227 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 1227, __PRETTY_FUNCTION__))
;
1228 OS << "'" << FileName << "': ";
1229 if (Line.hasValue())
1230 OS << "line " << Line.getValue() << ": ";
1231 Err->log(OS);
1232 }
1233
1234 StringRef getFileName() { return FileName; }
1235
1236 Error takeError() { return Error(std::move(Err)); }
1237
1238 std::error_code convertToErrorCode() const override;
1239
1240 // Used by ErrorInfo::classID.
1241 static char ID;
1242
1243private:
1244 FileError(const Twine &F, Optional<size_t> LineNum,
1245 std::unique_ptr<ErrorInfoBase> E) {
1246 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 1246, __PRETTY_FUNCTION__))
;
1247 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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 1248, __PRETTY_FUNCTION__))
1248 "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-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Error.h"
, 1248, __PRETTY_FUNCTION__))
;
1249 FileName = F.str();
1250 Err = std::move(E);
1251 Line = std::move(LineNum);
1252 }
1253
1254 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1255 std::unique_ptr<ErrorInfoBase> Payload;
1256 handleAllErrors(std::move(E),
1257 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1258 Payload = std::move(EIB);
1259 return Error::success();
1260 });
1261 return Error(
1262 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1263 }
1264
1265 std::string FileName;
1266 Optional<size_t> Line;
1267 std::unique_ptr<ErrorInfoBase> Err;
1268};
1269
1270/// Concatenate a source file path and/or name with an Error. The resulting
1271/// Error is unchecked.
1272inline Error createFileError(const Twine &F, Error E) {
1273 return FileError::build(F, Optional<size_t>(), std::move(E));
1274}
1275
1276/// Concatenate a source file path and/or name with line number and an Error.
1277/// The resulting Error is unchecked.
1278inline Error createFileError(const Twine &F, size_t Line, Error E) {
1279 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1280}
1281
1282/// Concatenate a source file path and/or name with a std::error_code
1283/// to form an Error object.
1284inline Error createFileError(const Twine &F, std::error_code EC) {
1285 return createFileError(F, errorCodeToError(EC));
1286}
1287
1288/// Concatenate a source file path and/or name with line number and
1289/// std::error_code to form an Error object.
1290inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1291 return createFileError(F, Line, errorCodeToError(EC));
1292}
1293
1294Error createFileError(const Twine &F, ErrorSuccess) = delete;
1295
1296/// Helper for check-and-exit error handling.
1297///
1298/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1299///
1300class ExitOnError {
1301public:
1302 /// Create an error on exit helper.
1303 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1304 : Banner(std::move(Banner)),
1305 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1306
1307 /// Set the banner string for any errors caught by operator().
1308 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1309
1310 /// Set the exit-code mapper function.
1311 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1312 this->GetExitCode = std::move(GetExitCode);
1313 }
1314
1315 /// Check Err. If it's in a failure state log the error(s) and exit.
1316 void operator()(Error Err) const { checkError(std::move(Err)); }
1317
1318 /// Check E. If it's in a success state then return the contained value. 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 std::move(*E);
1323 }
1324
1325 /// Check E. If it's in a success state then return the contained reference. If
1326 /// it's in a failure state log the error(s) and exit.
1327 template <typename T> T& operator()(Expected<T&> &&E) const {
1328 checkError(E.takeError());
1329 return *E;
1330 }
1331
1332private:
1333 void checkError(Error Err) const {
1334 if (Err) {
1335 int ExitCode = GetExitCode(Err);
1336 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1337 exit(ExitCode);
1338 }
1339 }
1340
1341 std::string Banner;
1342 std::function<int(const Error &)> GetExitCode;
1343};
1344
1345/// Conversion from Error to LLVMErrorRef for C error bindings.
1346inline LLVMErrorRef wrap(Error Err) {
1347 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1348}
1349
1350/// Conversion from LLVMErrorRef to Error for C error bindings.
1351inline Error unwrap(LLVMErrorRef ErrRef) {
1352 return Error(std::unique_ptr<ErrorInfoBase>(
1353 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1354}
1355
1356} // end namespace llvm
1357
1358#endif // LLVM_SUPPORT_ERROR_H