Bug Summary

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

Annotated Source Code

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

/build/llvm-toolchain-snapshot-10~svn374877/tools/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 "ASTReaderInternals.h"
14#include "clang/Basic/FileManager.h"
15#include "clang/Lex/HeaderSearch.h"
16#include "clang/Serialization/ASTBitCodes.h"
17#include "clang/Serialization/GlobalModuleIndex.h"
18#include "clang/Serialization/Module.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(std::unique_ptr<llvm::MemoryBuffer> Buffer,
129 llvm::BitstreamCursor Cursor)
130 : Buffer(std::move(Buffer)), IdentifierIndex(), NumIdentifierLookups(),
131 NumIdentifierLookupHits() {
132 auto Fail = [&Buffer](llvm::Error &&Err) {
133 report_fatal_error("Module index '" + Buffer->getBufferIdentifier() +
134 "' failed: " + toString(std::move(Err)));
135 };
136
137 llvm::TimeTraceScope TimeScope("Module LoadIndex", StringRef(""));
138 // Read the global index.
139 bool InGlobalIndexBlock = false;
140 bool Done = false;
141 while (!Done) {
142 llvm::BitstreamEntry Entry;
143 if (Expected<llvm::BitstreamEntry> Res = Cursor.advance())
144 Entry = Res.get();
145 else
146 Fail(Res.takeError());
147
148 switch (Entry.Kind) {
149 case llvm::BitstreamEntry::Error:
150 return;
151
152 case llvm::BitstreamEntry::EndBlock:
153 if (InGlobalIndexBlock) {
154 InGlobalIndexBlock = false;
155 Done = true;
156 continue;
157 }
158 return;
159
160
161 case llvm::BitstreamEntry::Record:
162 // Entries in the global index block are handled below.
163 if (InGlobalIndexBlock)
164 break;
165
166 return;
167
168 case llvm::BitstreamEntry::SubBlock:
169 if (!InGlobalIndexBlock && Entry.ID == GLOBAL_INDEX_BLOCK_ID) {
170 if (llvm::Error Err = Cursor.EnterSubBlock(GLOBAL_INDEX_BLOCK_ID))
171 Fail(std::move(Err));
172 InGlobalIndexBlock = true;
173 } else if (llvm::Error Err = Cursor.SkipBlock())
174 Fail(std::move(Err));
175 continue;
176 }
177
178 SmallVector<uint64_t, 64> Record;
179 StringRef Blob;
180 Expected<unsigned> MaybeIndexRecord =
181 Cursor.readRecord(Entry.ID, Record, &Blob);
182 if (!MaybeIndexRecord)
183 Fail(MaybeIndexRecord.takeError());
184 IndexRecordTypes IndexRecord =
185 static_cast<IndexRecordTypes>(MaybeIndexRecord.get());
186 switch (IndexRecord) {
187 case INDEX_METADATA:
188 // Make sure that the version matches.
189 if (Record.size() < 1 || Record[0] != CurrentVersion)
190 return;
191 break;
192
193 case MODULE: {
194 unsigned Idx = 0;
195 unsigned ID = Record[Idx++];
196
197 // Make room for this module's information.
198 if (ID == Modules.size())
199 Modules.push_back(ModuleInfo());
200 else
201 Modules.resize(ID + 1);
202
203 // Size/modification time for this module file at the time the
204 // global index was built.
205 Modules[ID].Size = Record[Idx++];
206 Modules[ID].ModTime = Record[Idx++];
207
208 // File name.
209 unsigned NameLen = Record[Idx++];
210 Modules[ID].FileName.assign(Record.begin() + Idx,
211 Record.begin() + Idx + NameLen);
212 Idx += NameLen;
213
214 // Dependencies
215 unsigned NumDeps = Record[Idx++];
216 Modules[ID].Dependencies.insert(Modules[ID].Dependencies.end(),
217 Record.begin() + Idx,
218 Record.begin() + Idx + NumDeps);
219 Idx += NumDeps;
220
221 // Make sure we're at the end of the record.
222 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-10~svn374877/tools/clang/lib/Serialization/GlobalModuleIndex.cpp"
, 222, __PRETTY_FUNCTION__))
;
223
224 // Record this module as an unresolved module.
225 // FIXME: this doesn't work correctly for module names containing path
226 // separators.
227 StringRef ModuleName = llvm::sys::path::stem(Modules[ID].FileName);
228 // Remove the -<hash of ModuleMapPath>
229 ModuleName = ModuleName.rsplit('-').first;
230 UnresolvedModules[ModuleName] = ID;
231 break;
232 }
233
234 case IDENTIFIER_INDEX:
235 // Wire up the identifier index.
236 if (Record[0]) {
237 IdentifierIndex = IdentifierIndexTable::Create(
238 (const unsigned char *)Blob.data() + Record[0],
239 (const unsigned char *)Blob.data() + sizeof(uint32_t),
240 (const unsigned char *)Blob.data(), IdentifierIndexReaderTrait());
241 }
242 break;
243 }
244 }
245}
246
247GlobalModuleIndex::~GlobalModuleIndex() {
248 delete static_cast<IdentifierIndexTable *>(IdentifierIndex);
249}
250
251std::pair<GlobalModuleIndex *, llvm::Error>
252GlobalModuleIndex::readIndex(StringRef Path) {
253 // Load the index file, if it's there.
254 llvm::SmallString<128> IndexPath;
255 IndexPath += Path;
256 llvm::sys::path::append(IndexPath, IndexFileName);
257
258 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> BufferOrErr =
259 llvm::MemoryBuffer::getFile(IndexPath.c_str());
260 if (!BufferOrErr)
261 return std::make_pair(nullptr,
262 llvm::errorCodeToError(BufferOrErr.getError()));
263 std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrErr.get());
264
265 /// The main bitstream cursor for the main block.
266 llvm::BitstreamCursor Cursor(*Buffer);
267
268 // Sniff for the signature.
269 for (unsigned char C : {'B', 'C', 'G', 'I'}) {
270 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Cursor.Read(8)) {
271 if (Res.get() != C)
272 return std::make_pair(
273 nullptr, llvm::createStringError(std::errc::illegal_byte_sequence,
274 "expected signature BCGI"));
275 } else
276 return std::make_pair(nullptr, Res.takeError());
277 }
278
279 return std::make_pair(new GlobalModuleIndex(std::move(Buffer), Cursor),
280 llvm::Error::success());
281}
282
283void
284GlobalModuleIndex::getKnownModules(SmallVectorImpl<ModuleFile *> &ModuleFiles) {
285 ModuleFiles.clear();
286 for (unsigned I = 0, N = Modules.size(); I != N; ++I) {
287 if (ModuleFile *MF = Modules[I].File)
288 ModuleFiles.push_back(MF);
289 }
290}
291
292void GlobalModuleIndex::getModuleDependencies(
293 ModuleFile *File,
294 SmallVectorImpl<ModuleFile *> &Dependencies) {
295 // Look for information about this module file.
296 llvm::DenseMap<ModuleFile *, unsigned>::iterator Known
297 = ModulesByFile.find(File);
298 if (Known == ModulesByFile.end())
299 return;
300
301 // Record dependencies.
302 Dependencies.clear();
303 ArrayRef<unsigned> StoredDependencies = Modules[Known->second].Dependencies;
304 for (unsigned I = 0, N = StoredDependencies.size(); I != N; ++I) {
305 if (ModuleFile *MF = Modules[I].File)
306 Dependencies.push_back(MF);
307 }
308}
309
310bool GlobalModuleIndex::lookupIdentifier(StringRef Name, HitSet &Hits) {
311 Hits.clear();
312
313 // If there's no identifier index, there is nothing we can do.
314 if (!IdentifierIndex)
315 return false;
316
317 // Look into the identifier index.
318 ++NumIdentifierLookups;
319 IdentifierIndexTable &Table
320 = *static_cast<IdentifierIndexTable *>(IdentifierIndex);
321 IdentifierIndexTable::iterator Known = Table.find(Name);
322 if (Known == Table.end()) {
323 return true;
324 }
325
326 SmallVector<unsigned, 2> ModuleIDs = *Known;
327 for (unsigned I = 0, N = ModuleIDs.size(); I != N; ++I) {
328 if (ModuleFile *MF = Modules[ModuleIDs[I]].File)
329 Hits.insert(MF);
330 }
331
332 ++NumIdentifierLookupHits;
333 return true;
334}
335
336bool GlobalModuleIndex::loadedModuleFile(ModuleFile *File) {
337 // Look for the module in the global module index based on the module name.
338 StringRef Name = File->ModuleName;
339 llvm::StringMap<unsigned>::iterator Known = UnresolvedModules.find(Name);
340 if (Known == UnresolvedModules.end()) {
341 return true;
342 }
343
344 // Rectify this module with the global module index.
345 ModuleInfo &Info = Modules[Known->second];
346
347 // If the size and modification time match what we expected, record this
348 // module file.
349 bool Failed = true;
350 if (File->File->getSize() == Info.Size &&
351 File->File->getModificationTime() == Info.ModTime) {
352 Info.File = File;
353 ModulesByFile[File] = Known->second;
354
355 Failed = false;
356 }
357
358 // One way or another, we have resolved this module file.
359 UnresolvedModules.erase(Known);
360 return Failed;
361}
362
363void GlobalModuleIndex::printStats() {
364 std::fprintf(stderrstderr, "*** Global Module Index Statistics:\n");
365 if (NumIdentifierLookups) {
366 fprintf(stderrstderr, " %u / %u identifier lookups succeeded (%f%%)\n",
367 NumIdentifierLookupHits, NumIdentifierLookups,
368 (double)NumIdentifierLookupHits*100.0/NumIdentifierLookups);
369 }
370 std::fprintf(stderrstderr, "\n");
371}
372
373LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void GlobalModuleIndex::dump() {
374 llvm::errs() << "*** Global Module Index Dump:\n";
375 llvm::errs() << "Module files:\n";
376 for (auto &MI : Modules) {
377 llvm::errs() << "** " << MI.FileName << "\n";
378 if (MI.File)
379 MI.File->dump();
380 else
381 llvm::errs() << "\n";
382 }
383 llvm::errs() << "\n";
384}
385
386//----------------------------------------------------------------------------//
387// Global module index writer.
388//----------------------------------------------------------------------------//
389
390namespace {
391 /// Provides information about a specific module file.
392 struct ModuleFileInfo {
393 /// The numberic ID for this module file.
394 unsigned ID;
395
396 /// The set of modules on which this module depends. Each entry is
397 /// a module ID.
398 SmallVector<unsigned, 4> Dependencies;
399 ASTFileSignature Signature;
400 };
401
402 struct ImportedModuleFileInfo {
403 off_t StoredSize;
404 time_t StoredModTime;
405 ASTFileSignature StoredSignature;
406 ImportedModuleFileInfo(off_t Size, time_t ModTime, ASTFileSignature Sig)
407 : StoredSize(Size), StoredModTime(ModTime), StoredSignature(Sig) {}
408 };
409
410 /// Builder that generates the global module index file.
411 class GlobalModuleIndexBuilder {
412 FileManager &FileMgr;
413 const PCHContainerReader &PCHContainerRdr;
414
415 /// Mapping from files to module file information.
416 typedef llvm::MapVector<const FileEntry *, ModuleFileInfo> ModuleFilesMap;
417
418 /// Information about each of the known module files.
419 ModuleFilesMap ModuleFiles;
420
421 /// Mapping from the imported module file to the imported
422 /// information.
423 typedef std::multimap<const FileEntry *, ImportedModuleFileInfo>
424 ImportedModuleFilesMap;
425
426 /// Information about each importing of a module file.
427 ImportedModuleFilesMap ImportedModuleFiles;
428
429 /// Mapping from identifiers to the list of module file IDs that
430 /// consider this identifier to be interesting.
431 typedef llvm::StringMap<SmallVector<unsigned, 2> > InterestingIdentifierMap;
432
433 /// A mapping from all interesting identifiers to the set of module
434 /// files in which those identifiers are considered interesting.
435 InterestingIdentifierMap InterestingIdentifiers;
436
437 /// Write the block-info block for the global module index file.
438 void emitBlockInfoBlock(llvm::BitstreamWriter &Stream);
439
440 /// Retrieve the module file information for the given file.
441 ModuleFileInfo &getModuleFileInfo(const FileEntry *File) {
442 llvm::MapVector<const FileEntry *, ModuleFileInfo>::iterator Known
443 = ModuleFiles.find(File);
444 if (Known != ModuleFiles.end())
445 return Known->second;
446
447 unsigned NewID = ModuleFiles.size();
448 ModuleFileInfo &Info = ModuleFiles[File];
449 Info.ID = NewID;
450 return Info;
451 }
452
453 public:
454 explicit GlobalModuleIndexBuilder(
455 FileManager &FileMgr, const PCHContainerReader &PCHContainerRdr)
456 : FileMgr(FileMgr), PCHContainerRdr(PCHContainerRdr) {}
457
458 /// Load the contents of the given module file into the builder.
459 llvm::Error loadModuleFile(const FileEntry *File);
460
461 /// Write the index to the given bitstream.
462 /// \returns true if an error occurred, false otherwise.
463 bool writeIndex(llvm::BitstreamWriter &Stream);
464 };
465}
466
467static void emitBlockID(unsigned ID, const char *Name,
468 llvm::BitstreamWriter &Stream,
469 SmallVectorImpl<uint64_t> &Record) {
470 Record.clear();
471 Record.push_back(ID);
472 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
473
474 // Emit the block name if present.
475 if (!Name || Name[0] == 0) return;
476 Record.clear();
477 while (*Name)
478 Record.push_back(*Name++);
479 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
480}
481
482static void emitRecordID(unsigned ID, const char *Name,
483 llvm::BitstreamWriter &Stream,
484 SmallVectorImpl<uint64_t> &Record) {
485 Record.clear();
486 Record.push_back(ID);
487 while (*Name)
488 Record.push_back(*Name++);
489 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
490}
491
492void
493GlobalModuleIndexBuilder::emitBlockInfoBlock(llvm::BitstreamWriter &Stream) {
494 SmallVector<uint64_t, 64> Record;
495 Stream.EnterBlockInfoBlock();
496
497#define BLOCK(X) emitBlockID(X ## _ID, #X, Stream, Record)
498#define RECORD(X) emitRecordID(X, #X, Stream, Record)
499 BLOCK(GLOBAL_INDEX_BLOCK);
500 RECORD(INDEX_METADATA);
501 RECORD(MODULE);
502 RECORD(IDENTIFIER_INDEX);
503#undef RECORD
504#undef BLOCK
505
506 Stream.ExitBlock();
507}
508
509namespace {
510 class InterestingASTIdentifierLookupTrait
511 : public serialization::reader::ASTIdentifierLookupTraitBase {
512
513 public:
514 /// The identifier and whether it is "interesting".
515 typedef std::pair<StringRef, bool> data_type;
516
517 data_type ReadData(const internal_key_type& k,
518 const unsigned char* d,
519 unsigned DataLen) {
520 // The first bit indicates whether this identifier is interesting.
521 // That's all we care about.
522 using namespace llvm::support;
523 unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
524 bool IsInteresting = RawID & 0x01;
525 return std::make_pair(k, IsInteresting);
526 }
527 };
528}
529
530llvm::Error GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
531 // Open the module file.
532
533 auto Buffer = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
534 if (!Buffer)
1
Taking false branch
535 return llvm::createStringError(Buffer.getError(),
536 "failed getting buffer for module file");
537
538 // Initialize the input stream
539 llvm::BitstreamCursor InStream(PCHContainerRdr.ExtractPCH(**Buffer));
540
541 // Sniff for the signature.
542 for (unsigned char C : {'C', 'P', 'C', 'H'})
2
Assuming '__begin1' is equal to '__end1'
543 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = InStream.Read(8)) {
544 if (Res.get() != C)
545 return llvm::createStringError(std::errc::illegal_byte_sequence,
546 "expected signature CPCH");
547 } else
548 return Res.takeError();
549
550 // Record this module file and assign it a unique ID (if it doesn't have
551 // one already).
552 unsigned ID = getModuleFileInfo(File).ID;
553
554 // Search for the blocks and records we care about.
555 enum { Other, ControlBlock, ASTBlock, DiagnosticOptionsBlock } State = Other;
556 bool Done = false;
557 while (!Done) {
3
Loop condition is true. Entering loop body
558 Expected<llvm::BitstreamEntry> MaybeEntry = InStream.advance();
4
Calling 'BitstreamCursor::advance'
559 if (!MaybeEntry)
560 return MaybeEntry.takeError();
561 llvm::BitstreamEntry Entry = MaybeEntry.get();
562
563 switch (Entry.Kind) {
564 case llvm::BitstreamEntry::Error:
565 Done = true;
566 continue;
567
568 case llvm::BitstreamEntry::Record:
569 // In the 'other' state, just skip the record. We don't care.
570 if (State == Other) {
571 if (llvm::Expected<unsigned> Skipped = InStream.skipRecord(Entry.ID))
572 continue;
573 else
574 return Skipped.takeError();
575 }
576
577 // Handle potentially-interesting records below.
578 break;
579
580 case llvm::BitstreamEntry::SubBlock:
581 if (Entry.ID == CONTROL_BLOCK_ID) {
582 if (llvm::Error Err = InStream.EnterSubBlock(CONTROL_BLOCK_ID))
583 return Err;
584
585 // Found the control block.
586 State = ControlBlock;
587 continue;
588 }
589
590 if (Entry.ID == AST_BLOCK_ID) {
591 if (llvm::Error Err = InStream.EnterSubBlock(AST_BLOCK_ID))
592 return Err;
593
594 // Found the AST block.
595 State = ASTBlock;
596 continue;
597 }
598
599 if (Entry.ID == UNHASHED_CONTROL_BLOCK_ID) {
600 if (llvm::Error Err = InStream.EnterSubBlock(UNHASHED_CONTROL_BLOCK_ID))
601 return Err;
602
603 // Found the Diagnostic Options block.
604 State = DiagnosticOptionsBlock;
605 continue;
606 }
607
608 if (llvm::Error Err = InStream.SkipBlock())
609 return Err;
610
611 continue;
612
613 case llvm::BitstreamEntry::EndBlock:
614 State = Other;
615 continue;
616 }
617
618 // Read the given record.
619 SmallVector<uint64_t, 64> Record;
620 StringRef Blob;
621 Expected<unsigned> MaybeCode = InStream.readRecord(Entry.ID, Record, &Blob);
622 if (!MaybeCode)
623 return MaybeCode.takeError();
624 unsigned Code = MaybeCode.get();
625
626 // Handle module dependencies.
627 if (State == ControlBlock && Code == IMPORTS) {
628 // Load each of the imported PCH files.
629 unsigned Idx = 0, N = Record.size();
630 while (Idx < N) {
631 // Read information about the AST file.
632
633 // Skip the imported kind
634 ++Idx;
635
636 // Skip the import location
637 ++Idx;
638
639 // Load stored size/modification time.
640 off_t StoredSize = (off_t)Record[Idx++];
641 time_t StoredModTime = (time_t)Record[Idx++];
642
643 // Skip the stored signature.
644 // FIXME: we could read the signature out of the import and validate it.
645 ASTFileSignature StoredSignature = {
646 {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
647 (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
648 (uint32_t)Record[Idx++]}}};
649
650 // Skip the module name (currently this is only used for prebuilt
651 // modules while here we are only dealing with cached).
652 Idx += Record[Idx] + 1;
653
654 // Retrieve the imported file name.
655 unsigned Length = Record[Idx++];
656 SmallString<128> ImportedFile(Record.begin() + Idx,
657 Record.begin() + Idx + Length);
658 Idx += Length;
659
660 // Find the imported module file.
661 auto DependsOnFile
662 = FileMgr.getFile(ImportedFile, /*OpenFile=*/false,
663 /*CacheFailure=*/false);
664
665 if (!DependsOnFile)
666 return llvm::createStringError(std::errc::bad_file_descriptor,
667 "imported file \"%s\" not found",
668 ImportedFile.c_str());
669
670 // Save the information in ImportedModuleFileInfo so we can verify after
671 // loading all pcms.
672 ImportedModuleFiles.insert(std::make_pair(
673 *DependsOnFile, ImportedModuleFileInfo(StoredSize, StoredModTime,
674 StoredSignature)));
675
676 // Record the dependency.
677 unsigned DependsOnID = getModuleFileInfo(*DependsOnFile).ID;
678 getModuleFileInfo(File).Dependencies.push_back(DependsOnID);
679 }
680
681 continue;
682 }
683
684 // Handle the identifier table
685 if (State == ASTBlock && Code == IDENTIFIER_TABLE && Record[0] > 0) {
686 typedef llvm::OnDiskIterableChainedHashTable<
687 InterestingASTIdentifierLookupTrait> InterestingIdentifierTable;
688 std::unique_ptr<InterestingIdentifierTable> Table(
689 InterestingIdentifierTable::Create(
690 (const unsigned char *)Blob.data() + Record[0],
691 (const unsigned char *)Blob.data() + sizeof(uint32_t),
692 (const unsigned char *)Blob.data()));
693 for (InterestingIdentifierTable::data_iterator D = Table->data_begin(),
694 DEnd = Table->data_end();
695 D != DEnd; ++D) {
696 std::pair<StringRef, bool> Ident = *D;
697 if (Ident.second)
698 InterestingIdentifiers[Ident.first].push_back(ID);
699 else
700 (void)InterestingIdentifiers[Ident.first];
701 }
702 }
703
704 // Get Signature.
705 if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
706 getModuleFileInfo(File).Signature = {
707 {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
708 (uint32_t)Record[3], (uint32_t)Record[4]}}};
709
710 // We don't care about this record.
711 }
712
713 return llvm::Error::success();
714}
715
716namespace {
717
718/// Trait used to generate the identifier index as an on-disk hash
719/// table.
720class IdentifierIndexWriterTrait {
721public:
722 typedef StringRef key_type;
723 typedef StringRef key_type_ref;
724 typedef SmallVector<unsigned, 2> data_type;
725 typedef const SmallVector<unsigned, 2> &data_type_ref;
726 typedef unsigned hash_value_type;
727 typedef unsigned offset_type;
728
729 static hash_value_type ComputeHash(key_type_ref Key) {
730 return llvm::djbHash(Key);
731 }
732
733 std::pair<unsigned,unsigned>
734 EmitKeyDataLength(raw_ostream& Out, key_type_ref Key, data_type_ref Data) {
735 using namespace llvm::support;
736 endian::Writer LE(Out, little);
737 unsigned KeyLen = Key.size();
738 unsigned DataLen = Data.size() * 4;
739 LE.write<uint16_t>(KeyLen);
740 LE.write<uint16_t>(DataLen);
741 return std::make_pair(KeyLen, DataLen);
742 }
743
744 void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
745 Out.write(Key.data(), KeyLen);
746 }
747
748 void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
749 unsigned DataLen) {
750 using namespace llvm::support;
751 for (unsigned I = 0, N = Data.size(); I != N; ++I)
752 endian::write<uint32_t>(Out, Data[I], little);
753 }
754};
755
756}
757
758bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
759 for (auto MapEntry : ImportedModuleFiles) {
760 auto *File = MapEntry.first;
761 ImportedModuleFileInfo &Info = MapEntry.second;
762 if (getModuleFileInfo(File).Signature) {
763 if (getModuleFileInfo(File).Signature != Info.StoredSignature)
764 // Verify Signature.
765 return true;
766 } else if (Info.StoredSize != File->getSize() ||
767 Info.StoredModTime != File->getModificationTime())
768 // Verify Size and ModTime.
769 return true;
770 }
771
772 using namespace llvm;
773 llvm::TimeTraceScope TimeScope("Module WriteIndex", StringRef(""));
774
775 // Emit the file header.
776 Stream.Emit((unsigned)'B', 8);
777 Stream.Emit((unsigned)'C', 8);
778 Stream.Emit((unsigned)'G', 8);
779 Stream.Emit((unsigned)'I', 8);
780
781 // Write the block-info block, which describes the records in this bitcode
782 // file.
783 emitBlockInfoBlock(Stream);
784
785 Stream.EnterSubblock(GLOBAL_INDEX_BLOCK_ID, 3);
786
787 // Write the metadata.
788 SmallVector<uint64_t, 2> Record;
789 Record.push_back(CurrentVersion);
790 Stream.EmitRecord(INDEX_METADATA, Record);
791
792 // Write the set of known module files.
793 for (ModuleFilesMap::iterator M = ModuleFiles.begin(),
794 MEnd = ModuleFiles.end();
795 M != MEnd; ++M) {
796 Record.clear();
797 Record.push_back(M->second.ID);
798 Record.push_back(M->first->getSize());
799 Record.push_back(M->first->getModificationTime());
800
801 // File name
802 StringRef Name(M->first->getName());
803 Record.push_back(Name.size());
804 Record.append(Name.begin(), Name.end());
805
806 // Dependencies
807 Record.push_back(M->second.Dependencies.size());
808 Record.append(M->second.Dependencies.begin(), M->second.Dependencies.end());
809 Stream.EmitRecord(MODULE, Record);
810 }
811
812 // Write the identifier -> module file mapping.
813 {
814 llvm::OnDiskChainedHashTableGenerator<IdentifierIndexWriterTrait> Generator;
815 IdentifierIndexWriterTrait Trait;
816
817 // Populate the hash table.
818 for (InterestingIdentifierMap::iterator I = InterestingIdentifiers.begin(),
819 IEnd = InterestingIdentifiers.end();
820 I != IEnd; ++I) {
821 Generator.insert(I->first(), I->second, Trait);
822 }
823
824 // Create the on-disk hash table in a buffer.
825 SmallString<4096> IdentifierTable;
826 uint32_t BucketOffset;
827 {
828 using namespace llvm::support;
829 llvm::raw_svector_ostream Out(IdentifierTable);
830 // Make sure that no bucket is at offset 0
831 endian::write<uint32_t>(Out, 0, little);
832 BucketOffset = Generator.Emit(Out, Trait);
833 }
834
835 // Create a blob abbreviation
836 auto Abbrev = std::make_shared<BitCodeAbbrev>();
837 Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_INDEX));
838 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
839 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
840 unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
841
842 // Write the identifier table
843 uint64_t Record[] = {IDENTIFIER_INDEX, BucketOffset};
844 Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
845 }
846
847 Stream.ExitBlock();
848 return false;
849}
850
851llvm::Error
852GlobalModuleIndex::writeIndex(FileManager &FileMgr,
853 const PCHContainerReader &PCHContainerRdr,
854 StringRef Path) {
855 llvm::SmallString<128> IndexPath;
856 IndexPath += Path;
857 llvm::sys::path::append(IndexPath, IndexFileName);
858
859 // Coordinate building the global index file with other processes that might
860 // try to do the same.
861 llvm::LockFileManager Locked(IndexPath);
862 switch (Locked) {
863 case llvm::LockFileManager::LFS_Error:
864 return llvm::createStringError(std::errc::io_error, "LFS error");
865
866 case llvm::LockFileManager::LFS_Owned:
867 // We're responsible for building the index ourselves. Do so below.
868 break;
869
870 case llvm::LockFileManager::LFS_Shared:
871 // Someone else is responsible for building the index. We don't care
872 // when they finish, so we're done.
873 return llvm::createStringError(std::errc::device_or_resource_busy,
874 "someone else is building the index");
875 }
876
877 // The module index builder.
878 GlobalModuleIndexBuilder Builder(FileMgr, PCHContainerRdr);
879
880 // Load each of the module files.
881 std::error_code EC;
882 for (llvm::sys::fs::directory_iterator D(Path, EC), DEnd;
883 D != DEnd && !EC;
884 D.increment(EC)) {
885 // If this isn't a module file, we don't care.
886 if (llvm::sys::path::extension(D->path()) != ".pcm") {
887 // ... unless it's a .pcm.lock file, which indicates that someone is
888 // in the process of rebuilding a module. They'll rebuild the index
889 // at the end of that translation unit, so we don't have to.
890 if (llvm::sys::path::extension(D->path()) == ".pcm.lock")
891 return llvm::createStringError(std::errc::device_or_resource_busy,
892 "someone else is building the index");
893
894 continue;
895 }
896
897 // If we can't find the module file, skip it.
898 auto ModuleFile = FileMgr.getFile(D->path());
899 if (!ModuleFile)
900 continue;
901
902 // Load this module file.
903 if (llvm::Error Err = Builder.loadModuleFile(*ModuleFile))
904 return Err;
905 }
906
907 // The output buffer, into which the global index will be written.
908 SmallVector<char, 16> OutputBuffer;
909 {
910 llvm::BitstreamWriter OutputStream(OutputBuffer);
911 if (Builder.writeIndex(OutputStream))
912 return llvm::createStringError(std::errc::io_error,
913 "failed writing index");
914 }
915
916 return llvm::writeFileAtomically(
917 (IndexPath + "-%%%%%%%%").str(), IndexPath,
918 llvm::StringRef(OutputBuffer.data(), OutputBuffer.size()));
919}
920
921namespace {
922 class GlobalIndexIdentifierIterator : public IdentifierIterator {
923 /// The current position within the identifier lookup table.
924 IdentifierIndexTable::key_iterator Current;
925
926 /// The end position within the identifier lookup table.
927 IdentifierIndexTable::key_iterator End;
928
929 public:
930 explicit GlobalIndexIdentifierIterator(IdentifierIndexTable &Idx) {
931 Current = Idx.key_begin();
932 End = Idx.key_end();
933 }
934
935 StringRef Next() override {
936 if (Current == End)
937 return StringRef();
938
939 StringRef Result = *Current;
940 ++Current;
941 return Result;
942 }
943 };
944}
945
946IdentifierIterator *GlobalModuleIndex::createIdentifierIterator() const {
947 IdentifierIndexTable &Table =
948 *static_cast<IdentifierIndexTable *>(IdentifierIndex);
949 return new GlobalIndexIdentifierIterator(Table);
950}

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

1//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This header defines the BitstreamReader class. This class can be used to
10// read an arbitrary bitstream, regardless of its contents.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H
15#define LLVM_BITSTREAM_BITSTREAMREADER_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Bitstream/BitCodes.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/MathExtras.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include <algorithm>
25#include <cassert>
26#include <climits>
27#include <cstddef>
28#include <cstdint>
29#include <memory>
30#include <string>
31#include <utility>
32#include <vector>
33
34namespace llvm {
35
36/// This class maintains the abbreviations read from a block info block.
37class BitstreamBlockInfo {
38public:
39 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
40 /// describe abbreviations that all blocks of the specified ID inherit.
41 struct BlockInfo {
42 unsigned BlockID;
43 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
44 std::string Name;
45 std::vector<std::pair<unsigned, std::string>> RecordNames;
46 };
47
48private:
49 std::vector<BlockInfo> BlockInfoRecords;
50
51public:
52 /// If there is block info for the specified ID, return it, otherwise return
53 /// null.
54 const BlockInfo *getBlockInfo(unsigned BlockID) const {
55 // Common case, the most recent entry matches BlockID.
56 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
57 return &BlockInfoRecords.back();
58
59 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
60 i != e; ++i)
61 if (BlockInfoRecords[i].BlockID == BlockID)
62 return &BlockInfoRecords[i];
63 return nullptr;
64 }
65
66 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
67 if (const BlockInfo *BI = getBlockInfo(BlockID))
68 return *const_cast<BlockInfo*>(BI);
69
70 // Otherwise, add a new record.
71 BlockInfoRecords.emplace_back();
72 BlockInfoRecords.back().BlockID = BlockID;
73 return BlockInfoRecords.back();
74 }
75};
76
77/// This represents a position within a bitstream. There may be multiple
78/// independent cursors reading within one bitstream, each maintaining their
79/// own local state.
80class SimpleBitstreamCursor {
81 ArrayRef<uint8_t> BitcodeBytes;
82 size_t NextChar = 0;
83
84public:
85 /// This is the current data we have pulled from the stream but have not
86 /// returned to the client. This is specifically and intentionally defined to
87 /// follow the word size of the host machine for efficiency. We use word_t in
88 /// places that are aware of this to make it perfectly explicit what is going
89 /// on.
90 using word_t = size_t;
91
92private:
93 word_t CurWord = 0;
94
95 /// This is the number of bits in CurWord that are valid. This is always from
96 /// [0...bits_of(size_t)-1] inclusive.
97 unsigned BitsInCurWord = 0;
98
99public:
100 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
101
102 SimpleBitstreamCursor() = default;
103 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
104 : BitcodeBytes(BitcodeBytes) {}
105 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
106 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
107 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
108 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
109
110 bool canSkipToPos(size_t pos) const {
111 // pos can be skipped to if it is a valid address or one byte past the end.
112 return pos <= BitcodeBytes.size();
113 }
114
115 bool AtEndOfStream() {
116 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
117 }
118
119 /// Return the bit # of the bit we are reading.
120 uint64_t GetCurrentBitNo() const {
121 return NextChar*CHAR_BIT8 - BitsInCurWord;
122 }
123
124 // Return the byte # of the current bit.
125 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
126
127 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
128
129 /// Reset the stream to the specified bit number.
130 Error JumpToBit(uint64_t BitNo) {
131 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
132 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
133 assert(canSkipToPos(ByteNo) && "Invalid location")((canSkipToPos(ByteNo) && "Invalid location") ? static_cast
<void> (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 133, __PRETTY_FUNCTION__))
;
134
135 // Move the cursor to the right word.
136 NextChar = ByteNo;
137 BitsInCurWord = 0;
138
139 // Skip over any bits that are already consumed.
140 if (WordBitNo) {
141 if (Expected<word_t> Res = Read(WordBitNo))
142 return Error::success();
143 else
144 return Res.takeError();
145 }
146
147 return Error::success();
148 }
149
150 /// Get a pointer into the bitstream at the specified byte offset.
151 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
152 return BitcodeBytes.data() + ByteNo;
153 }
154
155 /// Get a pointer into the bitstream at the specified bit offset.
156 ///
157 /// The bit offset must be on a byte boundary.
158 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
159 assert(!(BitNo % 8) && "Expected bit on byte boundary")((!(BitNo % 8) && "Expected bit on byte boundary") ? static_cast
<void> (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 159, __PRETTY_FUNCTION__))
;
160 return getPointerToByte(BitNo / 8, NumBytes);
161 }
162
163 Error fillCurWord() {
164 if (NextChar >= BitcodeBytes.size())
165 return createStringError(std::errc::io_error,
166 "Unexpected end of file reading %u of %u bytes",
167 NextChar, BitcodeBytes.size());
168
169 // Read the next word from the stream.
170 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
171 unsigned BytesRead;
172 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
173 BytesRead = sizeof(word_t);
174 CurWord =
175 support::endian::read<word_t, support::little, support::unaligned>(
176 NextCharPtr);
177 } else {
178 // Short read.
179 BytesRead = BitcodeBytes.size() - NextChar;
180 CurWord = 0;
181 for (unsigned B = 0; B != BytesRead; ++B)
182 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
183 }
184 NextChar += BytesRead;
185 BitsInCurWord = BytesRead * 8;
186 return Error::success();
187 }
188
189 Expected<word_t> Read(unsigned NumBits) {
190 static const unsigned BitsInWord = MaxChunkSize;
191
192 assert(NumBits && NumBits <= BitsInWord &&((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
9
Assuming 'NumBits' is not equal to 0
10
Assuming 'NumBits' is <= 'BitsInWord'
11
'?' condition is true
193 "Cannot return zero or more than BitsInWord bits!")((NumBits && NumBits <= BitsInWord && "Cannot return zero or more than BitsInWord bits!"
) ? static_cast<void> (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Bitstream/BitstreamReader.h"
, 193, __PRETTY_FUNCTION__))
;
194
195 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
12
'?' condition is true
196
197 // If the field is fully contained by CurWord, return it quickly.
198 if (BitsInCurWord >= NumBits) {
13
Assuming 'NumBits' is > field 'BitsInCurWord'
14
Taking false branch
199 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
200
201 // Use a mask to avoid undefined behavior.
202 CurWord >>= (NumBits & Mask);
203
204 BitsInCurWord -= NumBits;
205 return R;
206 }
207
208 word_t R = BitsInCurWord
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
209 unsigned BitsLeft = NumBits - BitsInCurWord;
210
211 if (Error fillResult = fillCurWord())
16
Calling 'Error::operator bool'
18
Returning from 'Error::operator bool'
19
Taking false branch
212 return std::move(fillResult);
213
214 // If we run out of data, abort.
215 if (BitsLeft > BitsInCurWord)
20
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
21
Taking false branch
216 return createStringError(std::errc::io_error,
217 "Unexpected end of file reading %u of %u bits",
218 BitsInCurWord, BitsLeft);
219
220 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
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'
221
222 // Use a mask to avoid undefined behavior.
223 CurWord >>= (BitsLeft & Mask);
224
225 BitsInCurWord -= BitsLeft;
226
227 R |= R2 << (NumBits - BitsLeft);
228
229 return R;
230 }
231
232 Expected<uint32_t> ReadVBR(unsigned NumBits) {
233 Expected<unsigned> MaybeRead = Read(NumBits);
234 if (!MaybeRead)
235 return MaybeRead;
236 uint32_t Piece = MaybeRead.get();
237
238 if ((Piece & (1U << (NumBits-1))) == 0)
239 return Piece;
240
241 uint32_t Result = 0;
242 unsigned NextBit = 0;
243 while (true) {
244 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
245
246 if ((Piece & (1U << (NumBits-1))) == 0)
247 return Result;
248
249 NextBit += NumBits-1;
250 MaybeRead = Read(NumBits);
251 if (!MaybeRead)
252 return MaybeRead;
253 Piece = MaybeRead.get();
254 }
255 }
256
257 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
258 // the VBR must still be <= 32 bits though.
259 Expected<uint64_t> ReadVBR64(unsigned NumBits) {
260 Expected<uint64_t> MaybeRead = Read(NumBits);
261 if (!MaybeRead)
262 return MaybeRead;
263 uint32_t Piece = MaybeRead.get();
264
265 if ((Piece & (1U << (NumBits-1))) == 0)
266 return uint64_t(Piece);
267
268 uint64_t Result = 0;
269 unsigned NextBit = 0;
270 while (true) {
271 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
272
273 if ((Piece & (1U << (NumBits-1))) == 0)
274 return Result;
275
276 NextBit += NumBits-1;
277 MaybeRead = Read(NumBits);
278 if (!MaybeRead)
279 return MaybeRead;
280 Piece = MaybeRead.get();
281 }
282 }
283
284 void SkipToFourByteBoundary() {
285 // If word_t is 64-bits and if we've read less than 32 bits, just dump
286 // the bits we have up to the next 32-bit boundary.
287 if (sizeof(word_t) > 4 &&
288 BitsInCurWord >= 32) {
289 CurWord >>= BitsInCurWord-32;
290 BitsInCurWord = 32;
291 return;
292 }
293
294 BitsInCurWord = 0;
295 }
296
297 /// Return the size of the stream in bytes.
298 size_t SizeInBytes() const { return BitcodeBytes.size(); }
299
300 /// Skip to the end of the file.
301 void skipToEnd() { NextChar = BitcodeBytes.size(); }
302};
303
304/// When advancing through a bitstream cursor, each advance can discover a few
305/// different kinds of entries:
306struct BitstreamEntry {
307 enum {
308 Error, // Malformed bitcode was found.
309 EndBlock, // We've reached the end of the current block, (or the end of the
310 // file, which is treated like a series of EndBlock records.
311 SubBlock, // This is the start of a new subblock of a specific ID.
312 Record // This is a record with a specific AbbrevID.
313 } Kind;
314
315 unsigned ID;
316
317 static BitstreamEntry getError() {
318 BitstreamEntry E; E.Kind = Error; return E;
319 }
320
321 static BitstreamEntry getEndBlock() {
322 BitstreamEntry E; E.Kind = EndBlock; return E;
323 }
324
325 static BitstreamEntry getSubBlock(unsigned ID) {
326 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
327 }
328
329 static BitstreamEntry getRecord(unsigned AbbrevID) {
330 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
331 }
332};
333
334/// This represents a position within a bitcode file, implemented on top of a
335/// SimpleBitstreamCursor.
336///
337/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
338/// be passed by value.
339class BitstreamCursor : SimpleBitstreamCursor {
340 // This is the declared size of code values used for the current block, in
341 // bits.
342 unsigned CurCodeSize = 2;
343
344 /// Abbrevs installed at in this block.
345 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
346
347 struct Block {
348 unsigned PrevCodeSize;
349 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
350
351 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
352 };
353
354 /// This tracks the codesize of parent blocks.
355 SmallVector<Block, 8> BlockScope;
356
357 BitstreamBlockInfo *BlockInfo = nullptr;
358
359public:
360 static const size_t MaxChunkSize = sizeof(word_t) * 8;
361
362 BitstreamCursor() = default;
363 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
364 : SimpleBitstreamCursor(BitcodeBytes) {}
365 explicit BitstreamCursor(StringRef BitcodeBytes)
366 : SimpleBitstreamCursor(BitcodeBytes) {}
367 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
368 : SimpleBitstreamCursor(BitcodeBytes) {}
369
370 using SimpleBitstreamCursor::AtEndOfStream;
371 using SimpleBitstreamCursor::canSkipToPos;
372 using SimpleBitstreamCursor::fillCurWord;
373 using SimpleBitstreamCursor::getBitcodeBytes;
374 using SimpleBitstreamCursor::GetCurrentBitNo;
375 using SimpleBitstreamCursor::getCurrentByteNo;
376 using SimpleBitstreamCursor::getPointerToByte;
377 using SimpleBitstreamCursor::JumpToBit;
378 using SimpleBitstreamCursor::Read;
379 using SimpleBitstreamCursor::ReadVBR;
380 using SimpleBitstreamCursor::ReadVBR64;
381 using SimpleBitstreamCursor::SizeInBytes;
382 using SimpleBitstreamCursor::skipToEnd;
383
384 /// Return the number of bits used to encode an abbrev #.
385 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
386
387 /// Flags that modify the behavior of advance().
388 enum {
389 /// If this flag is used, the advance() method does not automatically pop
390 /// the block scope when the end of a block is reached.
391 AF_DontPopBlockAtEnd = 1,
392
393 /// If this flag is used, abbrev entries are returned just like normal
394 /// records.
395 AF_DontAutoprocessAbbrevs = 2
396 };
397
398 /// Advance the current bitstream, returning the next entry in the stream.
399 Expected<BitstreamEntry> advance(unsigned Flags = 0) {
400 while (true) {
5
Loop condition is true. Entering loop body
401 if (AtEndOfStream())
6
Taking false branch
402 return BitstreamEntry::getError();
403
404 Expected<unsigned> MaybeCode = ReadCode();
7
Calling 'BitstreamCursor::ReadCode'
405 if (!MaybeCode)
406 return MaybeCode.takeError();
407 unsigned Code = MaybeCode.get();
408
409 if (Code == bitc::END_BLOCK) {
410 // Pop the end of the block unless Flags tells us not to.
411 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
412 return BitstreamEntry::getError();
413 return BitstreamEntry::getEndBlock();
414 }
415
416 if (Code == bitc::ENTER_SUBBLOCK) {
417 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID())
418 return BitstreamEntry::getSubBlock(MaybeSubBlock.get());
419 else
420 return MaybeSubBlock.takeError();
421 }
422
423 if (Code == bitc::DEFINE_ABBREV &&
424 !(Flags & AF_DontAutoprocessAbbrevs)) {
425 // We read and accumulate abbrev's, the client can't do anything with
426 // them anyway.
427 if (Error Err = ReadAbbrevRecord())
428 return std::move(Err);
429 continue;
430 }
431
432 return BitstreamEntry::getRecord(Code);
433 }
434 }
435
436 /// This is a convenience function for clients that don't expect any
437 /// subblocks. This just skips over them automatically.
438 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) {
439 while (true) {
440 // If we found a normal entry, return it.
441 Expected<BitstreamEntry> MaybeEntry = advance(Flags);
442 if (!MaybeEntry)
443 return MaybeEntry;
444 BitstreamEntry Entry = MaybeEntry.get();
445
446 if (Entry.Kind != BitstreamEntry::SubBlock)
447 return Entry;
448
449 // If we found a sub-block, just skip over it and check the next entry.
450 if (Error Err = SkipBlock())
451 return std::move(Err);
452 }
453 }
454
455 Expected<unsigned> ReadCode() { return Read(CurCodeSize); }
8
Calling 'SimpleBitstreamCursor::Read'
456
457 // Block header:
458 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
459
460 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
461 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); }
462
463 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
464 /// of this block.
465 Error SkipBlock() {
466 // Read and ignore the codelen value.
467 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth))
468 ; // Since we are skipping this block, we don't care what code widths are
469 // used inside of it.
470 else
471 return Res.takeError();
472
473 SkipToFourByteBoundary();
474 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth);
475 if (!MaybeNum)
476 return MaybeNum.takeError();
477 size_t NumFourBytes = MaybeNum.get();
478
479 // Check that the block wasn't partially defined, and that the offset isn't
480 // bogus.
481 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8;
482 if (AtEndOfStream())
483 return createStringError(std::errc::illegal_byte_sequence,
484 "can't skip block: already at end of stream");
485 if (!canSkipToPos(SkipTo / 8))
486 return createStringError(std::errc::illegal_byte_sequence,
487 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo,
488 GetCurrentBitNo());
489
490 if (Error Res = JumpToBit(SkipTo))
491 return Res;
492
493 return Error::success();
494 }
495
496 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
497 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
498
499 bool ReadBlockEnd() {
500 if (BlockScope.empty()) return true;
501
502 // Block tail:
503 // [END_BLOCK, <align4bytes>]
504 SkipToFourByteBoundary();
505
506 popBlockScope();
507 return false;
508 }
509
510private:
511 void popBlockScope() {
512 CurCodeSize = BlockScope.back().PrevCodeSize;
513
514 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
515 BlockScope.pop_back();
516 }
517
518 //===--------------------------------------------------------------------===//
519 // Record Processing
520 //===--------------------------------------------------------------------===//
521
522public:
523 /// Return the abbreviation for the specified AbbrevId.
524 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
525 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
526 if (AbbrevNo >= CurAbbrevs.size())
527 report_fatal_error("Invalid abbrev number");
528 return CurAbbrevs[AbbrevNo].get();
529 }
530
531 /// Read the current record and discard it, returning the code for the record.
532 Expected<unsigned> skipRecord(unsigned AbbrevID);
533
534 Expected<unsigned> readRecord(unsigned AbbrevID,
535 SmallVectorImpl<uint64_t> &Vals,
536 StringRef *Blob = nullptr);
537
538 //===--------------------------------------------------------------------===//
539 // Abbrev Processing
540 //===--------------------------------------------------------------------===//
541 Error ReadAbbrevRecord();
542
543 /// Read and return a block info block from the bitstream. If an error was
544 /// encountered, return None.
545 ///
546 /// \param ReadBlockInfoNames Whether to read block/record name information in
547 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
548 Expected<Optional<BitstreamBlockInfo>>
549 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
550
551 /// Set the block info to be used by this BitstreamCursor to interpret
552 /// abbreviated records.
553 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
554};
555
556} // end llvm namespace
557
558#endif // LLVM_BITSTREAM_BITSTREAMREADER_H

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

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
159 // pointers out of this class to add to the error list.
160 friend class ErrorList;
161 friend class FileError;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
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-10~svn374877/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
386 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
;
387 Payloads.push_back(std::move(Payload1));
388 Payloads.push_back(std::move(Payload2));
389 }
390
391 static Error join(Error E1, Error E2) {
392 if (!E1)
393 return E2;
394 if (!E2)
395 return E1;
396 if (E1.isA<ErrorList>()) {
397 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
398 if (E2.isA<ErrorList>()) {
399 auto E2Payload = E2.takePayload();
400 auto &E2List = static_cast<ErrorList &>(*E2Payload);
401 for (auto &Payload : E2List.Payloads)
402 E1List.Payloads.push_back(std::move(Payload));
403 } else
404 E1List.Payloads.push_back(E2.takePayload());
405
406 return E1;
407 }
408 if (E2.isA<ErrorList>()) {
409 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
410 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
411 return E2;
412 }
413 return Error(std::unique_ptr<ErrorList>(
414 new ErrorList(E1.takePayload(), E2.takePayload())));
415 }
416
417 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
418};
419
420/// Concatenate errors. The resulting Error is unchecked, and contains the
421/// ErrorInfo(s), if any, contained in E1, followed by the
422/// ErrorInfo(s), if any, contained in E2.
423inline Error joinErrors(Error E1, Error E2) {
424 return ErrorList::join(std::move(E1), std::move(E2));
425}
426
427/// Tagged union holding either a T or a Error.
428///
429/// This class parallels ErrorOr, but replaces error_code with Error. Since
430/// Error cannot be copied, this class replaces getError() with
431/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
432/// error class type.
433template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
434 template <class T1> friend class ExpectedAsOutParameter;
435 template <class OtherT> friend class Expected;
436
437 static const bool isRef = std::is_reference<T>::value;
438
439 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
440
441 using error_type = std::unique_ptr<ErrorInfoBase>;
442
443public:
444 using storage_type = typename std::conditional<isRef, wrap, T>::type;
445 using value_type = T;
446
447private:
448 using reference = typename std::remove_reference<T>::type &;
449 using const_reference = const typename std::remove_reference<T>::type &;
450 using pointer = typename std::remove_reference<T>::type *;
451 using const_pointer = const typename std::remove_reference<T>::type *;
452
453public:
454 /// Create an Expected<T> error value from the given Error.
455 Expected(Error Err)
456 : HasError(true)
457#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
458 // Expected is unchecked upon construction in Debug builds.
459 , Unchecked(true)
460#endif
461 {
462 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 462, __PRETTY_FUNCTION__))
;
463 new (getErrorStorage()) error_type(Err.takePayload());
464 }
465
466 /// Forbid to convert from Error::success() implicitly, this avoids having
467 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
468 /// but triggers the assertion above.
469 Expected(ErrorSuccess) = delete;
470
471 /// Create an Expected<T> success value from the given OtherT value, which
472 /// must be convertible to T.
473 template <typename OtherT>
474 Expected(OtherT &&Val,
475 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
476 * = nullptr)
477 : HasError(false)
478#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
479 // Expected is unchecked upon construction in Debug builds.
480 , Unchecked(true)
481#endif
482 {
483 new (getStorage()) storage_type(std::forward<OtherT>(Val));
484 }
485
486 /// Move construct an Expected<T> value.
487 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
488
489 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
490 /// must be convertible to T.
491 template <class OtherT>
492 Expected(Expected<OtherT> &&Other,
493 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
494 * = nullptr) {
495 moveConstruct(std::move(Other));
496 }
497
498 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
499 /// isn't convertible to T.
500 template <class OtherT>
501 explicit Expected(
502 Expected<OtherT> &&Other,
503 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
504 nullptr) {
505 moveConstruct(std::move(Other));
506 }
507
508 /// Move-assign from another Expected<T>.
509 Expected &operator=(Expected &&Other) {
510 moveAssign(std::move(Other));
511 return *this;
512 }
513
514 /// Destroy an Expected<T>.
515 ~Expected() {
516 assertIsChecked();
517 if (!HasError)
518 getStorage()->~storage_type();
519 else
520 getErrorStorage()->~error_type();
521 }
522
523 /// Return false if there is an error.
524 explicit operator bool() {
525#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
526 Unchecked = HasError;
527#endif
528 return !HasError;
529 }
530
531 /// Returns a reference to the stored T value.
532 reference get() {
533 assertIsChecked();
534 return *getStorage();
535 }
536
537 /// Returns a const reference to the stored T value.
538 const_reference get() const {
539 assertIsChecked();
540 return const_cast<Expected<T> *>(this)->get();
541 }
542
543 /// Check that this Expected<T> is an error of type ErrT.
544 template <typename ErrT> bool errorIsA() const {
545 return HasError && (*getErrorStorage())->template isA<ErrT>();
546 }
547
548 /// Take ownership of the stored error.
549 /// After calling this the Expected<T> is in an indeterminate state that can
550 /// only be safely destructed. No further calls (beside the destructor) should
551 /// be made on the Expected<T> value.
552 Error takeError() {
553#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
554 Unchecked = false;
555#endif
556 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
557 }
558
559 /// Returns a pointer to the stored T value.
560 pointer operator->() {
561 assertIsChecked();
562 return toPointer(getStorage());
563 }
564
565 /// Returns a const pointer to the stored T value.
566 const_pointer operator->() const {
567 assertIsChecked();
568 return toPointer(getStorage());
569 }
570
571 /// Returns a reference to the stored T value.
572 reference operator*() {
573 assertIsChecked();
574 return *getStorage();
575 }
576
577 /// Returns a const reference to the stored T value.
578 const_reference operator*() const {
579 assertIsChecked();
580 return *getStorage();
581 }
582
583private:
584 template <class T1>
585 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
586 return &a == &b;
587 }
588
589 template <class T1, class T2>
590 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
591 return false;
592 }
593
594 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
595 HasError = Other.HasError;
596#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
597 Unchecked = true;
598 Other.Unchecked = false;
599#endif
600
601 if (!HasError)
602 new (getStorage()) storage_type(std::move(*Other.getStorage()));
603 else
604 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
605 }
606
607 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
608 assertIsChecked();
609
610 if (compareThisIfSameType(*this, Other))
611 return;
612
613 this->~Expected();
614 new (this) Expected(std::move(Other));
615 }
616
617 pointer toPointer(pointer Val) { return Val; }
618
619 const_pointer toPointer(const_pointer Val) const { return Val; }
620
621 pointer toPointer(wrap *Val) { return &Val->get(); }
622
623 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
624
625 storage_type *getStorage() {
626 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 626, __PRETTY_FUNCTION__))
;
627 return reinterpret_cast<storage_type *>(TStorage.buffer);
628 }
629
630 const storage_type *getStorage() const {
631 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 631, __PRETTY_FUNCTION__))
;
632 return reinterpret_cast<const storage_type *>(TStorage.buffer);
633 }
634
635 error_type *getErrorStorage() {
636 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 636, __PRETTY_FUNCTION__))
;
637 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
638 }
639
640 const error_type *getErrorStorage() const {
641 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 641, __PRETTY_FUNCTION__))
;
642 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
643 }
644
645 // Used by ExpectedAsOutParameter to reset the checked flag.
646 void setUnchecked() {
647#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
648 Unchecked = true;
649#endif
650 }
651
652#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
653 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
654 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
655 void fatalUncheckedExpected() const {
656 dbgs() << "Expected<T> must be checked before access or destruction.\n";
657 if (HasError) {
658 dbgs() << "Unchecked Expected<T> contained error:\n";
659 (*getErrorStorage())->log(dbgs());
660 } else
661 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
662 "values in success mode must still be checked prior to being "
663 "destroyed).\n";
664 abort();
665 }
666#endif
667
668 void assertIsChecked() {
669#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
670 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
671 fatalUncheckedExpected();
672#endif
673 }
674
675 union {
676 AlignedCharArrayUnion<storage_type> TStorage;
677 AlignedCharArrayUnion<error_type> ErrorStorage;
678 };
679 bool HasError : 1;
680#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
681 bool Unchecked : 1;
682#endif
683};
684
685/// Report a serious error, calling any installed error handler. See
686/// ErrorHandling.h.
687LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
688 bool gen_crash_diag = true);
689
690/// Report a fatal error if Err is a failure value.
691///
692/// This function can be used to wrap calls to fallible functions ONLY when it
693/// is known that the Error will always be a success value. E.g.
694///
695/// @code{.cpp}
696/// // foo only attempts the fallible operation if DoFallibleOperation is
697/// // true. If DoFallibleOperation is false then foo always returns
698/// // Error::success().
699/// Error foo(bool DoFallibleOperation);
700///
701/// cantFail(foo(false));
702/// @endcode
703inline void cantFail(Error Err, const char *Msg = nullptr) {
704 if (Err) {
705 if (!Msg)
706 Msg = "Failure value returned from cantFail wrapped call";
707 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 707)
;
708 }
709}
710
711/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
712/// returns the contained value.
713///
714/// This function can be used to wrap calls to fallible functions ONLY when it
715/// is known that the Error will always be a success value. E.g.
716///
717/// @code{.cpp}
718/// // foo only attempts the fallible operation if DoFallibleOperation is
719/// // true. If DoFallibleOperation is false then foo always returns an int.
720/// Expected<int> foo(bool DoFallibleOperation);
721///
722/// int X = cantFail(foo(false));
723/// @endcode
724template <typename T>
725T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
726 if (ValOrErr)
727 return std::move(*ValOrErr);
728 else {
729 if (!Msg)
730 Msg = "Failure value returned from cantFail wrapped call";
731 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 731)
;
732 }
733}
734
735/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
736/// returns the contained reference.
737///
738/// This function can be used to wrap calls to fallible functions ONLY when it
739/// is known that the Error will always be a success value. E.g.
740///
741/// @code{.cpp}
742/// // foo only attempts the fallible operation if DoFallibleOperation is
743/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
744/// Expected<Bar&> foo(bool DoFallibleOperation);
745///
746/// Bar &X = cantFail(foo(false));
747/// @endcode
748template <typename T>
749T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
750 if (ValOrErr)
751 return *ValOrErr;
752 else {
753 if (!Msg)
754 Msg = "Failure value returned from cantFail wrapped call";
755 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 755)
;
756 }
757}
758
759/// Helper for testing applicability of, and applying, handlers for
760/// ErrorInfo types.
761template <typename HandlerT>
762class ErrorHandlerTraits
763 : public ErrorHandlerTraits<decltype(
764 &std::remove_reference<HandlerT>::type::operator())> {};
765
766// Specialization functions of the form 'Error (const ErrT&)'.
767template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
768public:
769 static bool appliesTo(const ErrorInfoBase &E) {
770 return E.template isA<ErrT>();
771 }
772
773 template <typename HandlerT>
774 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
775 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 775, __PRETTY_FUNCTION__))
;
776 return H(static_cast<ErrT &>(*E));
777 }
778};
779
780// Specialization functions of the form 'void (const ErrT&)'.
781template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
782public:
783 static bool appliesTo(const ErrorInfoBase &E) {
784 return E.template isA<ErrT>();
785 }
786
787 template <typename HandlerT>
788 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
789 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 789, __PRETTY_FUNCTION__))
;
790 H(static_cast<ErrT &>(*E));
791 return Error::success();
792 }
793};
794
795/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
796template <typename ErrT>
797class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
798public:
799 static bool appliesTo(const ErrorInfoBase &E) {
800 return E.template isA<ErrT>();
801 }
802
803 template <typename HandlerT>
804 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
805 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 805, __PRETTY_FUNCTION__))
;
806 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
807 return H(std::move(SubE));
808 }
809};
810
811/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
812template <typename ErrT>
813class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
814public:
815 static bool appliesTo(const ErrorInfoBase &E) {
816 return E.template isA<ErrT>();
817 }
818
819 template <typename HandlerT>
820 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
821 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 821, __PRETTY_FUNCTION__))
;
822 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
823 H(std::move(SubE));
824 return Error::success();
825 }
826};
827
828// Specialization for member functions of the form 'RetT (const ErrT&)'.
829template <typename C, typename RetT, typename ErrT>
830class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
831 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
832
833// Specialization for member functions of the form 'RetT (const ErrT&) const'.
834template <typename C, typename RetT, typename ErrT>
835class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
836 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
837
838// Specialization for member functions of the form 'RetT (const ErrT&)'.
839template <typename C, typename RetT, typename ErrT>
840class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
841 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
842
843// Specialization for member functions of the form 'RetT (const ErrT&) const'.
844template <typename C, typename RetT, typename ErrT>
845class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
846 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
847
848/// Specialization for member functions of the form
849/// 'RetT (std::unique_ptr<ErrT>)'.
850template <typename C, typename RetT, typename ErrT>
851class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
852 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
853
854/// Specialization for member functions of the form
855/// 'RetT (std::unique_ptr<ErrT>) const'.
856template <typename C, typename RetT, typename ErrT>
857class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
858 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
859
860inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
861 return Error(std::move(Payload));
862}
863
864template <typename HandlerT, typename... HandlerTs>
865Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
866 HandlerT &&Handler, HandlerTs &&... Handlers) {
867 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
868 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
869 std::move(Payload));
870 return handleErrorImpl(std::move(Payload),
871 std::forward<HandlerTs>(Handlers)...);
872}
873
874/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
875/// unhandled errors (or Errors returned by handlers) are re-concatenated and
876/// returned.
877/// Because this function returns an error, its result must also be checked
878/// or returned. If you intend to handle all errors use handleAllErrors
879/// (which returns void, and will abort() on unhandled errors) instead.
880template <typename... HandlerTs>
881Error handleErrors(Error E, HandlerTs &&... Hs) {
882 if (!E)
883 return Error::success();
884
885 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
886
887 if (Payload->isA<ErrorList>()) {
888 ErrorList &List = static_cast<ErrorList &>(*Payload);
889 Error R;
890 for (auto &P : List.Payloads)
891 R = ErrorList::join(
892 std::move(R),
893 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
894 return R;
895 }
896
897 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
898}
899
900/// Behaves the same as handleErrors, except that by contract all errors
901/// *must* be handled by the given handlers (i.e. there must be no remaining
902/// errors after running the handlers, or llvm_unreachable is called).
903template <typename... HandlerTs>
904void handleAllErrors(Error E, HandlerTs &&... Handlers) {
905 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
906}
907
908/// Check that E is a non-error, then drop it.
909/// If E is an error, llvm_unreachable will be called.
910inline void handleAllErrors(Error E) {
911 cantFail(std::move(E));
912}
913
914/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
915///
916/// If the incoming value is a success value it is returned unmodified. If it
917/// is a failure value then it the contained error is passed to handleErrors.
918/// If handleErrors is able to handle the error then the RecoveryPath functor
919/// is called to supply the final result. If handleErrors is not able to
920/// handle all errors then the unhandled errors are returned.
921///
922/// This utility enables the follow pattern:
923///
924/// @code{.cpp}
925/// enum FooStrategy { Aggressive, Conservative };
926/// Expected<Foo> foo(FooStrategy S);
927///
928/// auto ResultOrErr =
929/// handleExpected(
930/// foo(Aggressive),
931/// []() { return foo(Conservative); },
932/// [](AggressiveStrategyError&) {
933/// // Implicitly conusme this - we'll recover by using a conservative
934/// // strategy.
935/// });
936///
937/// @endcode
938template <typename T, typename RecoveryFtor, typename... HandlerTs>
939Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
940 HandlerTs &&... Handlers) {
941 if (ValOrErr)
942 return ValOrErr;
943
944 if (auto Err = handleErrors(ValOrErr.takeError(),
945 std::forward<HandlerTs>(Handlers)...))
946 return std::move(Err);
947
948 return RecoveryPath();
949}
950
951/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
952/// will be printed before the first one is logged. A newline will be printed
953/// after each error.
954///
955/// This function is compatible with the helpers from Support/WithColor.h. You
956/// can pass any of them as the OS. Please consider using them instead of
957/// including 'error: ' in the ErrorBanner.
958///
959/// This is useful in the base level of your program to allow clean termination
960/// (allowing clean deallocation of resources, etc.), while reporting error
961/// information to the user.
962void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
963
964/// Write all error messages (if any) in E to a string. The newline character
965/// is used to separate error messages.
966inline std::string toString(Error E) {
967 SmallVector<std::string, 2> Errors;
968 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
969 Errors.push_back(EI.message());
970 });
971 return join(Errors.begin(), Errors.end(), "\n");
972}
973
974/// Consume a Error without doing anything. This method should be used
975/// only where an error can be considered a reasonable and expected return
976/// value.
977///
978/// Uses of this method are potentially indicative of design problems: If it's
979/// legitimate to do nothing while processing an "error", the error-producer
980/// might be more clearly refactored to return an Optional<T>.
981inline void consumeError(Error Err) {
982 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
983}
984
985/// Convert an Expected to an Optional without doing anything. This method
986/// should be used only where an error can be considered a reasonable and
987/// expected return value.
988///
989/// Uses of this method are potentially indicative of problems: perhaps the
990/// error should be propagated further, or the error-producer should just
991/// return an Optional in the first place.
992template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
993 if (E)
994 return std::move(*E);
995 consumeError(E.takeError());
996 return None;
997}
998
999/// Helper for converting an Error to a bool.
1000///
1001/// This method returns true if Err is in an error state, or false if it is
1002/// in a success state. Puts Err in a checked state in both cases (unlike
1003/// Error::operator bool(), which only does this for success states).
1004inline bool errorToBool(Error Err) {
1005 bool IsError = static_cast<bool>(Err);
1006 if (IsError)
1007 consumeError(std::move(Err));
1008 return IsError;
1009}
1010
1011/// Helper for Errors used as out-parameters.
1012///
1013/// This helper is for use with the Error-as-out-parameter idiom, where an error
1014/// is passed to a function or method by reference, rather than being returned.
1015/// In such cases it is helpful to set the checked bit on entry to the function
1016/// so that the error can be written to (unchecked Errors abort on assignment)
1017/// and clear the checked bit on exit so that clients cannot accidentally forget
1018/// to check the result. This helper performs these actions automatically using
1019/// RAII:
1020///
1021/// @code{.cpp}
1022/// Result foo(Error &Err) {
1023/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1024/// // <body of foo>
1025/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1026/// }
1027/// @endcode
1028///
1029/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1030/// used with optional Errors (Error pointers that are allowed to be null). If
1031/// ErrorAsOutParameter took an Error reference, an instance would have to be
1032/// created inside every condition that verified that Error was non-null. By
1033/// taking an Error pointer we can just create one instance at the top of the
1034/// function.
1035class ErrorAsOutParameter {
1036public:
1037 ErrorAsOutParameter(Error *Err) : Err(Err) {
1038 // Raise the checked bit if Err is success.
1039 if (Err)
1040 (void)!!*Err;
1041 }
1042
1043 ~ErrorAsOutParameter() {
1044 // Clear the checked bit.
1045 if (Err && !*Err)
1046 *Err = Error::success();
1047 }
1048
1049private:
1050 Error *Err;
1051};
1052
1053/// Helper for Expected<T>s used as out-parameters.
1054///
1055/// See ErrorAsOutParameter.
1056template <typename T>
1057class ExpectedAsOutParameter {
1058public:
1059 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1060 : ValOrErr(ValOrErr) {
1061 if (ValOrErr)
1062 (void)!!*ValOrErr;
1063 }
1064
1065 ~ExpectedAsOutParameter() {
1066 if (ValOrErr)
1067 ValOrErr->setUnchecked();
1068 }
1069
1070private:
1071 Expected<T> *ValOrErr;
1072};
1073
1074/// This class wraps a std::error_code in a Error.
1075///
1076/// This is useful if you're writing an interface that returns a Error
1077/// (or Expected) and you want to call code that still returns
1078/// std::error_codes.
1079class ECError : public ErrorInfo<ECError> {
1080 friend Error errorCodeToError(std::error_code);
1081
1082 virtual void anchor() override;
1083
1084public:
1085 void setErrorCode(std::error_code EC) { this->EC = EC; }
1086 std::error_code convertToErrorCode() const override { return EC; }
1087 void log(raw_ostream &OS) const override { OS << EC.message(); }
1088
1089 // Used by ErrorInfo::classID.
1090 static char ID;
1091
1092protected:
1093 ECError() = default;
1094 ECError(std::error_code EC) : EC(EC) {}
1095
1096 std::error_code EC;
1097};
1098
1099/// The value returned by this function can be returned from convertToErrorCode
1100/// for Error values where no sensible translation to std::error_code exists.
1101/// It should only be used in this situation, and should never be used where a
1102/// sensible conversion to std::error_code is available, as attempts to convert
1103/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1104///error to try to convert such a value).
1105std::error_code inconvertibleErrorCode();
1106
1107/// Helper for converting an std::error_code to a Error.
1108Error errorCodeToError(std::error_code EC);
1109
1110/// Helper for converting an ECError to a std::error_code.
1111///
1112/// This method requires that Err be Error() or an ECError, otherwise it
1113/// will trigger a call to abort().
1114std::error_code errorToErrorCode(Error Err);
1115
1116/// Convert an ErrorOr<T> to an Expected<T>.
1117template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1118 if (auto EC = EO.getError())
1119 return errorCodeToError(EC);
1120 return std::move(*EO);
1121}
1122
1123/// Convert an Expected<T> to an ErrorOr<T>.
1124template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1125 if (auto Err = E.takeError())
1126 return errorToErrorCode(std::move(Err));
1127 return std::move(*E);
1128}
1129
1130/// This class wraps a string in an Error.
1131///
1132/// StringError is useful in cases where the client is not expected to be able
1133/// to consume the specific error message programmatically (for example, if the
1134/// error message is to be presented to the user).
1135///
1136/// StringError can also be used when additional information is to be printed
1137/// along with a error_code message. Depending on the constructor called, this
1138/// class can either display:
1139/// 1. the error_code message (ECError behavior)
1140/// 2. a string
1141/// 3. the error_code message and a string
1142///
1143/// These behaviors are useful when subtyping is required; for example, when a
1144/// specific library needs an explicit error type. In the example below,
1145/// PDBError is derived from StringError:
1146///
1147/// @code{.cpp}
1148/// Expected<int> foo() {
1149/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1150/// "Additional information");
1151/// }
1152/// @endcode
1153///
1154class StringError : public ErrorInfo<StringError> {
1155public:
1156 static char ID;
1157
1158 // Prints EC + S and converts to EC
1159 StringError(std::error_code EC, const Twine &S = Twine());
1160
1161 // Prints S and converts to EC
1162 StringError(const Twine &S, std::error_code EC);
1163
1164 void log(raw_ostream &OS) const override;
1165 std::error_code convertToErrorCode() const override;
1166
1167 const std::string &getMessage() const { return Msg; }
1168
1169private:
1170 std::string Msg;
1171 std::error_code EC;
1172 const bool PrintMsgOnly = false;
1173};
1174
1175/// Create formatted StringError object.
1176template <typename... Ts>
1177inline Error createStringError(std::error_code EC, char const *Fmt,
1178 const Ts &... Vals) {
1179 std::string Buffer;
1180 raw_string_ostream Stream(Buffer);
1181 Stream << format(Fmt, Vals...);
1182 return make_error<StringError>(Stream.str(), EC);
1183}
1184
1185Error createStringError(std::error_code EC, char const *Msg);
1186
1187inline Error createStringError(std::error_code EC, const Twine &S) {
1188 return createStringError(EC, S.str().c_str());
1189}
1190
1191template <typename... Ts>
1192inline Error createStringError(std::errc EC, char const *Fmt,
1193 const Ts &... Vals) {
1194 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1195}
1196
1197/// This class wraps a filename and another Error.
1198///
1199/// In some cases, an error needs to live along a 'source' name, in order to
1200/// show more detailed information to the user.
1201class FileError final : public ErrorInfo<FileError> {
1202
1203 friend Error createFileError(const Twine &, Error);
1204 friend Error createFileError(const Twine &, size_t, Error);
1205
1206public:
1207 void log(raw_ostream &OS) const override {
1208 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1208, __PRETTY_FUNCTION__))
;
1209 OS << "'" << FileName << "': ";
1210 if (Line.hasValue())
1211 OS << "line " << Line.getValue() << ": ";
1212 Err->log(OS);
1213 }
1214
1215 Error takeError() { return Error(std::move(Err)); }
1216
1217 std::error_code convertToErrorCode() const override;
1218
1219 // Used by ErrorInfo::classID.
1220 static char ID;
1221
1222private:
1223 FileError(const Twine &F, Optional<size_t> LineNum,
1224 std::unique_ptr<ErrorInfoBase> E) {
1225 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1225, __PRETTY_FUNCTION__))
;
1226 assert(!F.isTriviallyEmpty() &&((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1227, __PRETTY_FUNCTION__))
1227 "The file name provided to FileError must not be empty.")((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-10~svn374877/include/llvm/Support/Error.h"
, 1227, __PRETTY_FUNCTION__))
;
1228 FileName = F.str();
1229 Err = std::move(E);
1230 Line = std::move(LineNum);
1231 }
1232
1233 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1234 return Error(
1235 std::unique_ptr<FileError>(new FileError(F, Line, E.takePayload())));
1236 }
1237
1238 std::string FileName;
1239 Optional<size_t> Line;
1240 std::unique_ptr<ErrorInfoBase> Err;
1241};
1242
1243/// Concatenate a source file path and/or name with an Error. The resulting
1244/// Error is unchecked.
1245inline Error createFileError(const Twine &F, Error E) {
1246 return FileError::build(F, Optional<size_t>(), std::move(E));
1247}
1248
1249/// Concatenate a source file path and/or name with line number and an Error.
1250/// The resulting Error is unchecked.
1251inline Error createFileError(const Twine &F, size_t Line, Error E) {
1252 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1253}
1254
1255/// Concatenate a source file path and/or name with a std::error_code
1256/// to form an Error object.
1257inline Error createFileError(const Twine &F, std::error_code EC) {
1258 return createFileError(F, errorCodeToError(EC));
1259}
1260
1261/// Concatenate a source file path and/or name with line number and
1262/// std::error_code to form an Error object.
1263inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1264 return createFileError(F, Line, errorCodeToError(EC));
1265}
1266
1267Error createFileError(const Twine &F, ErrorSuccess) = delete;
1268
1269/// Helper for check-and-exit error handling.
1270///
1271/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1272///
1273class ExitOnError {
1274public:
1275 /// Create an error on exit helper.
1276 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1277 : Banner(std::move(Banner)),
1278 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1279
1280 /// Set the banner string for any errors caught by operator().
1281 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1282
1283 /// Set the exit-code mapper function.
1284 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1285 this->GetExitCode = std::move(GetExitCode);
1286 }
1287
1288 /// Check Err. If it's in a failure state log the error(s) and exit.
1289 void operator()(Error Err) const { checkError(std::move(Err)); }
1290
1291 /// Check E. If it's in a success state then return the contained value. If
1292 /// it's in a failure state log the error(s) and exit.
1293 template <typename T> T operator()(Expected<T> &&E) const {
1294 checkError(E.takeError());
1295 return std::move(*E);
1296 }
1297
1298 /// Check E. If it's in a success state then return the contained reference. If
1299 /// it's in a failure state log the error(s) and exit.
1300 template <typename T> T& operator()(Expected<T&> &&E) const {
1301 checkError(E.takeError());
1302 return *E;
1303 }
1304
1305private:
1306 void checkError(Error Err) const {
1307 if (Err) {
1308 int ExitCode = GetExitCode(Err);
1309 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1310 exit(ExitCode);
1311 }
1312 }
1313
1314 std::string Banner;
1315 std::function<int(const Error &)> GetExitCode;
1316};
1317
1318/// Conversion from Error to LLVMErrorRef for C error bindings.
1319inline LLVMErrorRef wrap(Error Err) {
1320 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1321}
1322
1323/// Conversion from LLVMErrorRef to Error for C error bindings.
1324inline Error unwrap(LLVMErrorRef ErrRef) {
1325 return Error(std::unique_ptr<ErrorInfoBase>(
1326 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1327}
1328
1329} // end namespace llvm
1330
1331#endif // LLVM_SUPPORT_ERROR_H