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 GlobalModuleIndex.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 -relaxed-aliasing -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 CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/lib/Serialization -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/Serialization -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/include -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/tools/clang/lib/Serialization -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 -fno-common -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/clang/lib/Serialization/GlobalModuleIndex.cpp

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/Serialization/GlobalModuleIndex.cpp

1//===--- GlobalModuleIndex.cpp - Global Module Index ------------*- 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 implements the GlobalModuleIndex class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Serialization/GlobalModuleIndex.h"
14#include "ASTReaderInternals.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Lex/HeaderSearch.h"
17#include "clang/Serialization/ASTBitCodes.h"
18#include "clang/Serialization/ModuleFile.h"
19#include "clang/Serialization/PCHContainerOperations.h"
20#include "llvm/ADT/DenseMap.h"
21#include "llvm/ADT/MapVector.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/StringRef.h"
24#include "llvm/Bitstream/BitstreamReader.h"
25#include "llvm/Bitstream/BitstreamWriter.h"
26#include "llvm/Support/DJB.h"
27#include "llvm/Support/FileSystem.h"
28#include "llvm/Support/FileUtilities.h"
29#include "llvm/Support/LockFileManager.h"
30#include "llvm/Support/MemoryBuffer.h"
31#include "llvm/Support/OnDiskHashTable.h"
32#include "llvm/Support/Path.h"
33#include "llvm/Support/TimeProfiler.h"
34#include <cstdio>
35using namespace clang;
36using namespace serialization;
37
38//----------------------------------------------------------------------------//
39// Shared constants
40//----------------------------------------------------------------------------//
41namespace {
42 enum {
43 /// The block containing the index.
44 GLOBAL_INDEX_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID
45 };
46
47 /// Describes the record types in the index.
48 enum IndexRecordTypes {
49 /// Contains version information and potentially other metadata,
50 /// used to determine if we can read this global index file.
51 INDEX_METADATA,
52 /// Describes a module, including its file name and dependencies.
53 MODULE,
54 /// The index for identifiers.
55 IDENTIFIER_INDEX
56 };
57}
58
59/// The name of the global index file.
60static const char * const IndexFileName = "modules.idx";
61
62/// The global index file version.
63static const unsigned CurrentVersion = 1;
64
65//----------------------------------------------------------------------------//
66// Global module index reader.
67//----------------------------------------------------------------------------//
68
69namespace {
70
71/// Trait used to read the identifier index from the on-disk hash
72/// table.
73class IdentifierIndexReaderTrait {
74public:
75 typedef StringRef external_key_type;
76 typedef StringRef internal_key_type;
77 typedef SmallVector<unsigned, 2> data_type;
78 typedef unsigned hash_value_type;
79 typedef unsigned offset_type;
80
81 static bool EqualKey(const internal_key_type& a, const internal_key_type& b) {
82 return a == b;
83 }
84
85 static hash_value_type ComputeHash(const internal_key_type& a) {
86 return llvm::djbHash(a);
87 }
88
89 static std::pair<unsigned, unsigned>
90 ReadKeyDataLength(const unsigned char*& d) {
91 using namespace llvm::support;
92 unsigned KeyLen = endian::readNext<uint16_t, little, unaligned>(d);
93 unsigned DataLen = endian::readNext<uint16_t, little, unaligned>(d);
94 return std::make_pair(KeyLen, DataLen);
95 }
96
97 static const internal_key_type&
98 GetInternalKey(const external_key_type& x) { return x; }
99
100 static const external_key_type&
101 GetExternalKey(const internal_key_type& x) { return x; }
102
103 static internal_key_type ReadKey(const unsigned char* d, unsigned n) {
104 return StringRef((const char *)d, n);
105 }
106
107 static data_type ReadData(const internal_key_type& k,
108 const unsigned char* d,
109 unsigned DataLen) {
110 using namespace llvm::support;
111
112 data_type Result;
113 while (DataLen > 0) {
114 unsigned ID = endian::readNext<uint32_t, little, unaligned>(d);
115 Result.push_back(ID);
116 DataLen -= 4;
117 }
118
119 return Result;
120 }
121};
122
123typedef llvm::OnDiskIterableChainedHashTable<IdentifierIndexReaderTrait>
124 IdentifierIndexTable;
125
126}
127
128GlobalModuleIndex::GlobalModuleIndex(
129 std::unique_ptr<llvm::MemoryBuffer> IndexBuffer,
130 llvm::BitstreamCursor Cursor)
131 : Buffer(std::move(IndexBuffer)), IdentifierIndex(), NumIdentifierLookups(),
132 NumIdentifierLookupHits() {
133 auto Fail = [&](llvm::Error &&Err) {
134 report_fatal_error("Module index '" + Buffer->getBufferIdentifier() +
135 "' failed: " + toString(std::move(Err)));
136 };
137
138 llvm::TimeTraceScope TimeScope("Module LoadIndex");
139 // Read the global index.
140 bool InGlobalIndexBlock = false;
141 bool Done = false;
142 while (!Done) {
143 llvm::BitstreamEntry Entry;
144 if (Expected<llvm::BitstreamEntry> Res = Cursor.advance())
145 Entry = Res.get();
146 else
147 Fail(Res.takeError());
148
149 switch (Entry.Kind) {
150 case llvm::BitstreamEntry::Error:
151 return;
152
153 case llvm::BitstreamEntry::EndBlock:
154 if (InGlobalIndexBlock) {
155 InGlobalIndexBlock = false;
156 Done = true;
157 continue;
158 }
159 return;
160
161
162 case llvm::BitstreamEntry::Record:
163 // Entries in the global index block are handled below.
164 if (InGlobalIndexBlock)
165 break;
166
167 return;
168
169 case llvm::BitstreamEntry::SubBlock:
170 if (!InGlobalIndexBlock && Entry.ID == GLOBAL_INDEX_BLOCK_ID) {
171 if (llvm::Error Err = Cursor.EnterSubBlock(GLOBAL_INDEX_BLOCK_ID))
172 Fail(std::move(Err));
173 InGlobalIndexBlock = true;
174 } else if (llvm::Error Err = Cursor.SkipBlock())
175 Fail(std::move(Err));
176 continue;
177 }
178
179 SmallVector<uint64_t, 64> Record;
180 StringRef Blob;
181 Expected<unsigned> MaybeIndexRecord =
182 Cursor.readRecord(Entry.ID, Record, &Blob);
183 if (!MaybeIndexRecord)
184 Fail(MaybeIndexRecord.takeError());
185 IndexRecordTypes IndexRecord =
186 static_cast<IndexRecordTypes>(MaybeIndexRecord.get());
187 switch (IndexRecord) {
188 case INDEX_METADATA:
189 // Make sure that the version matches.
190 if (Record.size() < 1 || Record[0] != CurrentVersion)
191 return;
192 break;
193
194 case MODULE: {
195 unsigned Idx = 0;
196 unsigned ID = Record[Idx++];
197
198 // Make room for this module's information.
199 if (ID == Modules.size())
200 Modules.push_back(ModuleInfo());
201 else
202 Modules.resize(ID + 1);
203
204 // Size/modification time for this module file at the time the
205 // global index was built.
206 Modules[ID].Size = Record[Idx++];
207 Modules[ID].ModTime = Record[Idx++];
208
209 // File name.
210 unsigned NameLen = Record[Idx++];
211 Modules[ID].FileName.assign(Record.begin() + Idx,
212 Record.begin() + Idx + NameLen);
213 Idx += NameLen;
214
215 // Dependencies
216 unsigned NumDeps = Record[Idx++];
217 Modules[ID].Dependencies.insert(Modules[ID].Dependencies.end(),
218 Record.begin() + Idx,
219 Record.begin() + Idx + NumDeps);
220 Idx += NumDeps;
221
222 // Make sure we're at the end of the record.
223 assert(Idx == Record.size() && "More module info?")((Idx == Record.size() && "More module info?") ? static_cast
<void> (0) : __assert_fail ("Idx == Record.size() && \"More module info?\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/Serialization/GlobalModuleIndex.cpp"
, 223, __PRETTY_FUNCTION__))
;
224
225 // Record this module as an unresolved module.
226 // FIXME: this doesn't work correctly for module names containing path
227 // separators.
228 StringRef ModuleName = llvm::sys::path::stem(Modules[ID].FileName);
229 // Remove the -<hash of ModuleMapPath>
230 ModuleName = ModuleName.rsplit('-').first;
231 UnresolvedModules[ModuleName] = ID;
232 break;
233 }
234
235 case IDENTIFIER_INDEX:
236 // Wire up the identifier index.
237 if (Record[0]) {
238 IdentifierIndex = IdentifierIndexTable::Create(
239 (const unsigned char *)Blob.data() + Record[0],
240 (const unsigned char *)Blob.data() + sizeof(uint32_t),
241 (const unsigned char *)Blob.data(), IdentifierIndexReaderTrait());
242 }
243 break;
244 }
245 }
246}
247
248GlobalModuleIndex::~GlobalModuleIndex() {
249 delete static_cast<IdentifierIndexTable *>(IdentifierIndex);
250}
251
252std::pair<GlobalModuleIndex *, llvm::Error>
253GlobalModuleIndex::readIndex(StringRef Path) {
254 // Load the index file, if it's there.
255 llvm::SmallString<128> IndexPath;
256 IndexPath += Path;
257 llvm::sys::path::append(IndexPath, IndexFileName);
258
259 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> BufferOrErr =
260 llvm::MemoryBuffer::getFile(IndexPath.c_str());
261 if (!BufferOrErr)
262 return std::make_pair(nullptr,
263 llvm::errorCodeToError(BufferOrErr.getError()));
264 std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrErr.get());
265
266 /// The main bitstream cursor for the main block.
267 llvm::BitstreamCursor Cursor(*Buffer);
268
269 // Sniff for the signature.
270 for (unsigned char C : {'B', 'C', 'G', 'I'}) {
271 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Cursor.Read(8)) {
272 if (Res.get() != C)
273 return std::make_pair(
274 nullptr, llvm::createStringError(std::errc::illegal_byte_sequence,
275 "expected signature BCGI"));
276 } else
277 return std::make_pair(nullptr, Res.takeError());
278 }
279
280 return std::make_pair(new GlobalModuleIndex(std::move(Buffer), Cursor),
281 llvm::Error::success());
282}
283
284void
285GlobalModuleIndex::getKnownModules(SmallVectorImpl<ModuleFile *> &ModuleFiles) {
286 ModuleFiles.clear();
287 for (unsigned I = 0, N = Modules.size(); I != N; ++I) {
288 if (ModuleFile *MF = Modules[I].File)
289 ModuleFiles.push_back(MF);
290 }
291}
292
293void GlobalModuleIndex::getModuleDependencies(
294 ModuleFile *File,
295 SmallVectorImpl<ModuleFile *> &Dependencies) {
296 // Look for information about this module file.
297 llvm::DenseMap<ModuleFile *, unsigned>::iterator Known
298 = ModulesByFile.find(File);
299 if (Known == ModulesByFile.end())
300 return;
301
302 // Record dependencies.
303 Dependencies.clear();
304 ArrayRef<unsigned> StoredDependencies = Modules[Known->second].Dependencies;
305 for (unsigned I = 0, N = StoredDependencies.size(); I != N; ++I) {
306 if (ModuleFile *MF = Modules[I].File)
307 Dependencies.push_back(MF);
308 }
309}
310
311bool GlobalModuleIndex::lookupIdentifier(StringRef Name, HitSet &Hits) {
312 Hits.clear();
313
314 // If there's no identifier index, there is nothing we can do.
315 if (!IdentifierIndex)
316 return false;
317
318 // Look into the identifier index.
319 ++NumIdentifierLookups;
320 IdentifierIndexTable &Table
321 = *static_cast<IdentifierIndexTable *>(IdentifierIndex);
322 IdentifierIndexTable::iterator Known = Table.find(Name);
323 if (Known == Table.end()) {
324 return true;
325 }
326
327 SmallVector<unsigned, 2> ModuleIDs = *Known;
328 for (unsigned I = 0, N = ModuleIDs.size(); I != N; ++I) {
329 if (ModuleFile *MF = Modules[ModuleIDs[I]].File)
330 Hits.insert(MF);
331 }
332
333 ++NumIdentifierLookupHits;
334 return true;
335}
336
337bool GlobalModuleIndex::loadedModuleFile(ModuleFile *File) {
338 // Look for the module in the global module index based on the module name.
339 StringRef Name = File->ModuleName;
340 llvm::StringMap<unsigned>::iterator Known = UnresolvedModules.find(Name);
341 if (Known == UnresolvedModules.end()) {
342 return true;
343 }
344
345 // Rectify this module with the global module index.
346 ModuleInfo &Info = Modules[Known->second];
347
348 // If the size and modification time match what we expected, record this
349 // module file.
350 bool Failed = true;
351 if (File->File->getSize() == Info.Size &&
352 File->File->getModificationTime() == Info.ModTime) {
353 Info.File = File;
354 ModulesByFile[File] = Known->second;
355
356 Failed = false;
357 }
358
359 // One way or another, we have resolved this module file.
360 UnresolvedModules.erase(Known);
361 return Failed;
362}
363
364void GlobalModuleIndex::printStats() {
365 std::fprintf(stderrstderr, "*** Global Module Index Statistics:\n");
366 if (NumIdentifierLookups) {
367 fprintf(stderrstderr, " %u / %u identifier lookups succeeded (%f%%)\n",
368 NumIdentifierLookupHits, NumIdentifierLookups,
369 (double)NumIdentifierLookupHits*100.0/NumIdentifierLookups);
370 }
371 std::fprintf(stderrstderr, "\n");
372}
373
374LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void GlobalModuleIndex::dump() {
375 llvm::errs() << "*** Global Module Index Dump:\n";
376 llvm::errs() << "Module files:\n";
377 for (auto &MI : Modules) {
378 llvm::errs() << "** " << MI.FileName << "\n";
379 if (MI.File)
380 MI.File->dump();
381 else
382 llvm::errs() << "\n";
383 }
384 llvm::errs() << "\n";
385}
386
387//----------------------------------------------------------------------------//
388// Global module index writer.
389//----------------------------------------------------------------------------//
390
391namespace {
392 /// Provides information about a specific module file.
393 struct ModuleFileInfo {
394 /// The numberic ID for this module file.
395 unsigned ID;
396
397 /// The set of modules on which this module depends. Each entry is
398 /// a module ID.
399 SmallVector<unsigned, 4> Dependencies;
400 ASTFileSignature Signature;
401 };
402
403 struct ImportedModuleFileInfo {
404 off_t StoredSize;
405 time_t StoredModTime;
406 ASTFileSignature StoredSignature;
407 ImportedModuleFileInfo(off_t Size, time_t ModTime, ASTFileSignature Sig)
408 : StoredSize(Size), StoredModTime(ModTime), StoredSignature(Sig) {}
409 };
410
411 /// Builder that generates the global module index file.
412 class GlobalModuleIndexBuilder {
413 FileManager &FileMgr;
414 const PCHContainerReader &PCHContainerRdr;
415
416 /// Mapping from files to module file information.
417 typedef llvm::MapVector<const FileEntry *, ModuleFileInfo> ModuleFilesMap;
418
419 /// Information about each of the known module files.
420 ModuleFilesMap ModuleFiles;
421
422 /// Mapping from the imported module file to the imported
423 /// information.
424 typedef std::multimap<const FileEntry *, ImportedModuleFileInfo>
425 ImportedModuleFilesMap;
426
427 /// Information about each importing of a module file.
428 ImportedModuleFilesMap ImportedModuleFiles;
429
430 /// Mapping from identifiers to the list of module file IDs that
431 /// consider this identifier to be interesting.
432 typedef llvm::StringMap<SmallVector<unsigned, 2> > InterestingIdentifierMap;
433
434 /// A mapping from all interesting identifiers to the set of module
435 /// files in which those identifiers are considered interesting.
436 InterestingIdentifierMap InterestingIdentifiers;
437
438 /// Write the block-info block for the global module index file.
439 void emitBlockInfoBlock(llvm::BitstreamWriter &Stream);
440
441 /// Retrieve the module file information for the given file.
442 ModuleFileInfo &getModuleFileInfo(const FileEntry *File) {
443 llvm::MapVector<const FileEntry *, ModuleFileInfo>::iterator Known
444 = ModuleFiles.find(File);
445 if (Known != ModuleFiles.end())
446 return Known->second;
447
448 unsigned NewID = ModuleFiles.size();
449 ModuleFileInfo &Info = ModuleFiles[File];
450 Info.ID = NewID;
451 return Info;
452 }
453
454 public:
455 explicit GlobalModuleIndexBuilder(
456 FileManager &FileMgr, const PCHContainerReader &PCHContainerRdr)
457 : FileMgr(FileMgr), PCHContainerRdr(PCHContainerRdr) {}
458
459 /// Load the contents of the given module file into the builder.
460 llvm::Error loadModuleFile(const FileEntry *File);
461
462 /// Write the index to the given bitstream.
463 /// \returns true if an error occurred, false otherwise.
464 bool writeIndex(llvm::BitstreamWriter &Stream);
465 };
466}
467
468static void emitBlockID(unsigned ID, const char *Name,
469 llvm::BitstreamWriter &Stream,
470 SmallVectorImpl<uint64_t> &Record) {
471 Record.clear();
472 Record.push_back(ID);
473 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
474
475 // Emit the block name if present.
476 if (!Name || Name[0] == 0) return;
477 Record.clear();
478 while (*Name)
479 Record.push_back(*Name++);
480 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
481}
482
483static void emitRecordID(unsigned ID, const char *Name,
484 llvm::BitstreamWriter &Stream,
485 SmallVectorImpl<uint64_t> &Record) {
486 Record.clear();
487 Record.push_back(ID);
488 while (*Name)
489 Record.push_back(*Name++);
490 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
491}
492
493void
494GlobalModuleIndexBuilder::emitBlockInfoBlock(llvm::BitstreamWriter &Stream) {
495 SmallVector<uint64_t, 64> Record;
496 Stream.EnterBlockInfoBlock();
497
498#define BLOCK(X) emitBlockID(X ## _ID, #X, Stream, Record)
499#define RECORD(X) emitRecordID(X, #X, Stream, Record)
500 BLOCK(GLOBAL_INDEX_BLOCK);
501 RECORD(INDEX_METADATA);
502 RECORD(MODULE);
503 RECORD(IDENTIFIER_INDEX);
504#undef RECORD
505#undef BLOCK
506
507 Stream.ExitBlock();
508}
509
510namespace {
511 class InterestingASTIdentifierLookupTrait
512 : public serialization::reader::ASTIdentifierLookupTraitBase {
513
514 public:
515 /// The identifier and whether it is "interesting".
516 typedef std::pair<StringRef, bool> data_type;
517
518 data_type ReadData(const internal_key_type& k,
519 const unsigned char* d,
520 unsigned DataLen) {
521 // The first bit indicates whether this identifier is interesting.
522 // That's all we care about.
523 using namespace llvm::support;
524 unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
525 bool IsInteresting = RawID & 0x01;
526 return std::make_pair(k, IsInteresting);
527 }
528 };
529}
530
531llvm::Error GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
532 // Open the module file.
533
534 auto Buffer = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
535 if (!Buffer)
1
Taking false branch
536 return llvm::createStringError(Buffer.getError(),
537 "failed getting buffer for module file");
538
539 // Initialize the input stream
540 llvm::BitstreamCursor InStream(PCHContainerRdr.ExtractPCH(**Buffer));
541
542 // Sniff for the signature.
543 for (unsigned char C : {'C', 'P', 'C', 'H'})
2
Assuming '__begin1' is equal to '__end1'
544 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = InStream.Read(8)) {
545 if (Res.get() != C)
546 return llvm::createStringError(std::errc::illegal_byte_sequence,
547 "expected signature CPCH");
548 } else
549 return Res.takeError();
550
551 // Record this module file and assign it a unique ID (if it doesn't have
552 // one already).
553 unsigned ID = getModuleFileInfo(File).ID;
554
555 // Search for the blocks and records we care about.
556 enum { Other, ControlBlock, ASTBlock, DiagnosticOptionsBlock } State = Other;
557 bool Done = false;
558 while (!Done) {
3
Loop condition is true. Entering loop body
559 Expected<llvm::BitstreamEntry> MaybeEntry = InStream.advance();
4
Calling 'BitstreamCursor::advance'
560 if (!MaybeEntry)
561 return MaybeEntry.takeError();
562 llvm::BitstreamEntry Entry = MaybeEntry.get();
563
564 switch (Entry.Kind) {
565 case llvm::BitstreamEntry::Error:
566 Done = true;
567 continue;
568
569 case llvm::BitstreamEntry::Record:
570 // In the 'other' state, just skip the record. We don't care.
571 if (State == Other) {
572 if (llvm::Expected<unsigned> Skipped = InStream.skipRecord(Entry.ID))
573 continue;
574 else
575 return Skipped.takeError();
576 }
577
578 // Handle potentially-interesting records below.
579 break;
580
581 case llvm::BitstreamEntry::SubBlock:
582 if (Entry.ID == CONTROL_BLOCK_ID) {
583 if (llvm::Error Err = InStream.EnterSubBlock(CONTROL_BLOCK_ID))
584 return Err;
585
586 // Found the control block.
587 State = ControlBlock;
588 continue;
589 }
590
591 if (Entry.ID == AST_BLOCK_ID) {
592 if (llvm::Error Err = InStream.EnterSubBlock(AST_BLOCK_ID))
593 return Err;
594
595 // Found the AST block.
596 State = ASTBlock;
597 continue;
598 }
599
600 if (Entry.ID == UNHASHED_CONTROL_BLOCK_ID) {
601 if (llvm::Error Err = InStream.EnterSubBlock(UNHASHED_CONTROL_BLOCK_ID))
602 return Err;
603
604 // Found the Diagnostic Options block.
605 State = DiagnosticOptionsBlock;
606 continue;
607 }
608
609 if (llvm::Error Err = InStream.SkipBlock())
610 return Err;
611
612 continue;
613
614 case llvm::BitstreamEntry::EndBlock:
615 State = Other;
616 continue;
617 }
618
619 // Read the given record.
620 SmallVector<uint64_t, 64> Record;
621 StringRef Blob;
622 Expected<unsigned> MaybeCode = InStream.readRecord(Entry.ID, Record, &Blob);
623 if (!MaybeCode)
624 return MaybeCode.takeError();
625 unsigned Code = MaybeCode.get();
626
627 // Handle module dependencies.
628 if (State == ControlBlock && Code == IMPORTS) {
629 // Load each of the imported PCH files.
630 unsigned Idx = 0, N = Record.size();
631 while (Idx < N) {
632 // Read information about the AST file.
633
634 // Skip the imported kind
635 ++Idx;
636
637 // Skip the import location
638 ++Idx;
639
640 // Load stored size/modification time.
641 off_t StoredSize = (off_t)Record[Idx++];
642 time_t StoredModTime = (time_t)Record[Idx++];
643
644 // Skip the stored signature.
645 // FIXME: we could read the signature out of the import and validate it.
646 ASTFileSignature StoredSignature = {
647 {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
648 (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
649 (uint32_t)Record[Idx++]}}};
650
651 // Skip the module name (currently this is only used for prebuilt
652 // modules while here we are only dealing with cached).
653 Idx += Record[Idx] + 1;
654
655 // Retrieve the imported file name.
656 unsigned Length = Record[Idx++];
657 SmallString<128> ImportedFile(Record.begin() + Idx,
658 Record.begin() + Idx + Length);
659 Idx += Length;
660
661 // Find the imported module file.
662 auto DependsOnFile
663 = FileMgr.getFile(ImportedFile, /*OpenFile=*/false,
664 /*CacheFailure=*/false);
665
666 if (!DependsOnFile)
667 return llvm::createStringError(std::errc::bad_file_descriptor,
668 "imported file \"%s\" not found",
669 ImportedFile.c_str());
670
671 // Save the information in ImportedModuleFileInfo so we can verify after
672 // loading all pcms.
673 ImportedModuleFiles.insert(std::make_pair(
674 *DependsOnFile, ImportedModuleFileInfo(StoredSize, StoredModTime,
675 StoredSignature)));
676
677 // Record the dependency.
678 unsigned DependsOnID = getModuleFileInfo(*DependsOnFile).ID;
679 getModuleFileInfo(File).Dependencies.push_back(DependsOnID);
680 }
681
682 continue;
683 }
684
685 // Handle the identifier table
686 if (State == ASTBlock && Code == IDENTIFIER_TABLE && Record[0] > 0) {
687 typedef llvm::OnDiskIterableChainedHashTable<
688 InterestingASTIdentifierLookupTrait> InterestingIdentifierTable;
689 std::unique_ptr<InterestingIdentifierTable> Table(
690 InterestingIdentifierTable::Create(
691 (const unsigned char *)Blob.data() + Record[0],
692 (const unsigned char *)Blob.data() + sizeof(uint32_t),
693 (const unsigned char *)Blob.data()));
694 for (InterestingIdentifierTable::data_iterator D = Table->data_begin(),
695 DEnd = Table->data_end();
696 D != DEnd; ++D) {
697 std::pair<StringRef, bool> Ident = *D;
698 if (Ident.second)
699 InterestingIdentifiers[Ident.first].push_back(ID);
700 else
701 (void)InterestingIdentifiers[Ident.first];
702 }
703 }
704
705 // Get Signature.
706 if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
707 getModuleFileInfo(File).Signature = {
708 {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
709 (uint32_t)Record[3], (uint32_t)Record[4]}}};
710
711 // We don't care about this record.
712 }
713
714 return llvm::Error::success();
715}
716
717namespace {
718
719/// Trait used to generate the identifier index as an on-disk hash
720/// table.
721class IdentifierIndexWriterTrait {
722public:
723 typedef StringRef key_type;
724 typedef StringRef key_type_ref;
725 typedef SmallVector<unsigned, 2> data_type;
726 typedef const SmallVector<unsigned, 2> &data_type_ref;
727 typedef unsigned hash_value_type;
728 typedef unsigned offset_type;
729
730 static hash_value_type ComputeHash(key_type_ref Key) {
731 return llvm::djbHash(Key);
732 }
733
734 std::pair<unsigned,unsigned>
735 EmitKeyDataLength(raw_ostream& Out, key_type_ref Key, data_type_ref Data) {
736 using namespace llvm::support;
737 endian::Writer LE(Out, little);
738 unsigned KeyLen = Key.size();
739 unsigned DataLen = Data.size() * 4;
740 LE.write<uint16_t>(KeyLen);
741 LE.write<uint16_t>(DataLen);
742 return std::make_pair(KeyLen, DataLen);
743 }
744
745 void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
746 Out.write(Key.data(), KeyLen);
747 }
748
749 void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
750 unsigned DataLen) {
751 using namespace llvm::support;
752 for (unsigned I = 0, N = Data.size(); I != N; ++I)
753 endian::write<uint32_t>(Out, Data[I], little);
754 }
755};
756
757}
758
759bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
760 for (auto MapEntry : ImportedModuleFiles) {
761 auto *File = MapEntry.first;
762 ImportedModuleFileInfo &Info = MapEntry.second;
763 if (getModuleFileInfo(File).Signature) {
764 if (getModuleFileInfo(File).Signature != Info.StoredSignature)
765 // Verify Signature.
766 return true;
767 } else if (Info.StoredSize != File->getSize() ||
768 Info.StoredModTime != File->getModificationTime())
769 // Verify Size and ModTime.
770 return true;
771 }
772
773 using namespace llvm;
774 llvm::TimeTraceScope TimeScope("Module WriteIndex");
775
776 // Emit the file header.
777 Stream.Emit((unsigned)'B', 8);
778 Stream.Emit((unsigned)'C', 8);
779 Stream.Emit((unsigned)'G', 8);
780 Stream.Emit((unsigned)'I', 8);
781
782 // Write the block-info block, which describes the records in this bitcode
783 // file.
784 emitBlockInfoBlock(Stream);
785
786 Stream.EnterSubblock(GLOBAL_INDEX_BLOCK_ID, 3);
787
788 // Write the metadata.
789 SmallVector<uint64_t, 2> Record;
790 Record.push_back(CurrentVersion);
791 Stream.EmitRecord(INDEX_METADATA, Record);
792
793 // Write the set of known module files.
794 for (ModuleFilesMap::iterator M = ModuleFiles.begin(),
795 MEnd = ModuleFiles.end();
796 M != MEnd; ++M) {
797 Record.clear();
798 Record.push_back(M->second.ID);
799 Record.push_back(M->first->getSize());
800 Record.push_back(M->first->getModificationTime());
801
802 // File name
803 StringRef Name(M->first->getName());
804 Record.push_back(Name.size());
805 Record.append(Name.begin(), Name.end());
806
807 // Dependencies
808 Record.push_back(M->second.Dependencies.size());
809 Record.append(M->second.Dependencies.begin(), M->second.Dependencies.end());
810 Stream.EmitRecord(MODULE, Record);
811 }
812
813 // Write the identifier -> module file mapping.
814 {
815 llvm::OnDiskChainedHashTableGenerator<IdentifierIndexWriterTrait> Generator;
816 IdentifierIndexWriterTrait Trait;
817
818 // Populate the hash table.
819 for (InterestingIdentifierMap::iterator I = InterestingIdentifiers.begin(),
820 IEnd = InterestingIdentifiers.end();
821 I != IEnd; ++I) {
822 Generator.insert(I->first(), I->second, Trait);
823 }
824
825 // Create the on-disk hash table in a buffer.
826 SmallString<4096> IdentifierTable;
827 uint32_t BucketOffset;
828 {
829 using namespace llvm::support;
830 llvm::raw_svector_ostream Out(IdentifierTable);
831 // Make sure that no bucket is at offset 0
832 endian::write<uint32_t>(Out, 0, little);
833 BucketOffset = Generator.Emit(Out, Trait);
834 }
835
836 // Create a blob abbreviation
837 auto Abbrev = std::make_shared<BitCodeAbbrev>();
838 Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_INDEX));
839 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
840 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
841 unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
842
843 // Write the identifier table
844 uint64_t Record[] = {IDENTIFIER_INDEX, BucketOffset};
845 Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
846 }
847
848 Stream.ExitBlock();
849 return false;
850}
851
852llvm::Error
853GlobalModuleIndex::writeIndex(FileManager &FileMgr,
854 const PCHContainerReader &PCHContainerRdr,
855 StringRef Path) {
856 llvm::SmallString<128> IndexPath;
857 IndexPath += Path;
858 llvm::sys::path::append(IndexPath, IndexFileName);
859
860 // Coordinate building the global index file with other processes that might
861 // try to do the same.
862 llvm::LockFileManager Locked(IndexPath);
863 switch (Locked) {
864 case llvm::LockFileManager::LFS_Error:
865 return llvm::createStringError(std::errc::io_error, "LFS error");
866
867 case llvm::LockFileManager::LFS_Owned:
868 // We're responsible for building the index ourselves. Do so below.
869 break;
870
871 case llvm::LockFileManager::LFS_Shared:
872 // Someone else is responsible for building the index. We don't care
873 // when they finish, so we're done.
874 return llvm::createStringError(std::errc::device_or_resource_busy,
875 "someone else is building the index");
876 }
877
878 // The module index builder.
879 GlobalModuleIndexBuilder Builder(FileMgr, PCHContainerRdr);
880
881 // Load each of the module files.
882 std::error_code EC;
883 for (llvm::sys::fs::directory_iterator D(Path, EC), DEnd;
884 D != DEnd && !EC;
885 D.increment(EC)) {
886 // If this isn't a module file, we don't care.
887 if (llvm::sys::path::extension(D->path()) != ".pcm") {
888 // ... unless it's a .pcm.lock file, which indicates that someone is
889 // in the process of rebuilding a module. They'll rebuild the index
890 // at the end of that translation unit, so we don't have to.
891 if (llvm::sys::path::extension(D->path()) == ".pcm.lock")
892 return llvm::createStringError(std::errc::device_or_resource_busy,
893 "someone else is building the index");
894
895 continue;
896 }
897
898 // If we can't find the module file, skip it.
899 auto ModuleFile = FileMgr.getFile(D->path());
900 if (!ModuleFile)
901 continue;
902
903 // Load this module file.
904 if (llvm::Error Err = Builder.loadModuleFile(*ModuleFile))
905 return Err;
906 }
907
908 // The output buffer, into which the global index will be written.
909 SmallVector<char, 16> OutputBuffer;
910 {
911 llvm::BitstreamWriter OutputStream(OutputBuffer);
912 if (Builder.writeIndex(OutputStream))
913 return llvm::createStringError(std::errc::io_error,
914 "failed writing index");
915 }
916
917 return llvm::writeFileAtomically(
918 (IndexPath + "-%%%%%%%%").str(), IndexPath,
919 llvm::StringRef(OutputBuffer.data(), OutputBuffer.size()));
920}
921
922namespace {
923 class GlobalIndexIdentifierIterator : public IdentifierIterator {
924 /// The current position within the identifier lookup table.
925 IdentifierIndexTable::key_iterator Current;
926
927 /// The end position within the identifier lookup table.
928 IdentifierIndexTable::key_iterator End;
929
930 public:
931 explicit GlobalIndexIdentifierIterator(IdentifierIndexTable &Idx) {
932 Current = Idx.key_begin();
933 End = Idx.key_end();
934 }
935
936 StringRef Next() override {
937 if (Current == End)
938 return StringRef();
939
940 StringRef Result = *Current;
941 ++Current;
942 return Result;
943 }
944 };
945}
946
947IdentifierIterator *GlobalModuleIndex::createIdentifierIterator() const {
948 IdentifierIndexTable &Table =
949 *static_cast<IdentifierIndexTable *>(IdentifierIndex);
950 return new GlobalIndexIdentifierIterator(Table);
951}

/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__))
9
Assuming 'NumBits' is not equal to 0
10
Assuming 'NumBits' is <= 'BitsInWord'
11
'?' 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;
12
'?' condition is true
197
198 // If the field is fully contained by CurWord, return it quickly.
199 if (BitsInCurWord >= NumBits) {
13
Assuming 'NumBits' is > field 'BitsInCurWord'
14
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
14.1
Field 'BitsInCurWord' is not equal to 0
14.1
Field 'BitsInCurWord' is not equal to 0
14.1
Field 'BitsInCurWord' is not equal to 0
? CurWord : 0;
15
'?' condition is true
210 unsigned BitsLeft = NumBits - BitsInCurWord;
211
212 if (Error fillResult = fillCurWord())
16
Calling 'Error::operator bool'
18
Returning from 'Error::operator bool'
19
Taking false branch
213 return std::move(fillResult);
214
215 // If we run out of data, abort.
216 if (BitsLeft > BitsInCurWord)
20
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
21
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));
22
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) {
5
Loop condition is true. Entering loop body
402 if (AtEndOfStream())
6
Taking false branch
403 return BitstreamEntry::getError();
404
405 Expected<unsigned> MaybeCode = ReadCode();
7
Calling 'BitstreamCursor::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); }
8
Calling 'SimpleBitstreamCursor::Read'
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;
17
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