Bug Summary

File:build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
Warning:line 191, column 29
Moved-from object 'Err' is moved

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name DwarfLinkerForBinary.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/dsymutil -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/tools/dsymutil -I include -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-04-20-140412-16051-1 -x c++ /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

→
1//===- tools/dsymutil/DwarfLinkerForBinary.cpp ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "DwarfLinkerForBinary.h"
10#include "BinaryHolder.h"
11#include "DebugMap.h"
12#include "MachOUtils.h"
13#include "dsymutil.h"
14#include "llvm/ADT/ArrayRef.h"
15#include "llvm/ADT/BitVector.h"
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/DenseMapInfo.h"
18#include "llvm/ADT/DenseSet.h"
19#include "llvm/ADT/FoldingSet.h"
20#include "llvm/ADT/Hashing.h"
21#include "llvm/ADT/IntervalMap.h"
22#include "llvm/ADT/None.h"
23#include "llvm/ADT/Optional.h"
24#include "llvm/ADT/PointerIntPair.h"
25#include "llvm/ADT/STLExtras.h"
26#include "llvm/ADT/SmallString.h"
27#include "llvm/ADT/StringMap.h"
28#include "llvm/ADT/StringRef.h"
29#include "llvm/ADT/Triple.h"
30#include "llvm/ADT/Twine.h"
31#include "llvm/BinaryFormat/Dwarf.h"
32#include "llvm/BinaryFormat/MachO.h"
33#include "llvm/BinaryFormat/Swift.h"
34#include "llvm/CodeGen/AccelTable.h"
35#include "llvm/CodeGen/AsmPrinter.h"
36#include "llvm/CodeGen/DIE.h"
37#include "llvm/CodeGen/NonRelocatableStringpool.h"
38#include "llvm/Config/config.h"
39#include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
40#include "llvm/DebugInfo/DIContext.h"
41#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
42#include "llvm/DebugInfo/DWARF/DWARFContext.h"
43#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
44#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
45#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
46#include "llvm/DebugInfo/DWARF/DWARFDie.h"
47#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
48#include "llvm/DebugInfo/DWARF/DWARFSection.h"
49#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
50#include "llvm/MC/MCAsmBackend.h"
51#include "llvm/MC/MCAsmInfo.h"
52#include "llvm/MC/MCCodeEmitter.h"
53#include "llvm/MC/MCContext.h"
54#include "llvm/MC/MCDwarf.h"
55#include "llvm/MC/MCInstrInfo.h"
56#include "llvm/MC/MCObjectFileInfo.h"
57#include "llvm/MC/MCObjectWriter.h"
58#include "llvm/MC/MCRegisterInfo.h"
59#include "llvm/MC/MCSection.h"
60#include "llvm/MC/MCStreamer.h"
61#include "llvm/MC/MCSubtargetInfo.h"
62#include "llvm/MC/MCTargetOptions.h"
63#include "llvm/MC/MCTargetOptionsCommandFlags.h"
64#include "llvm/MC/TargetRegistry.h"
65#include "llvm/Object/MachO.h"
66#include "llvm/Object/ObjectFile.h"
67#include "llvm/Object/SymbolicFile.h"
68#include "llvm/Support/Allocator.h"
69#include "llvm/Support/Casting.h"
70#include "llvm/Support/Compiler.h"
71#include "llvm/Support/DJB.h"
72#include "llvm/Support/DataExtractor.h"
73#include "llvm/Support/Error.h"
74#include "llvm/Support/ErrorHandling.h"
75#include "llvm/Support/ErrorOr.h"
76#include "llvm/Support/FileSystem.h"
77#include "llvm/Support/Format.h"
78#include "llvm/Support/LEB128.h"
79#include "llvm/Support/MathExtras.h"
80#include "llvm/Support/MemoryBuffer.h"
81#include "llvm/Support/Path.h"
82#include "llvm/Support/ThreadPool.h"
83#include "llvm/Support/ToolOutputFile.h"
84#include "llvm/Support/WithColor.h"
85#include "llvm/Support/raw_ostream.h"
86#include "llvm/Target/TargetMachine.h"
87#include "llvm/Target/TargetOptions.h"
88#include <algorithm>
89#include <cassert>
90#include <cinttypes>
91#include <climits>
92#include <cstdint>
93#include <cstdlib>
94#include <cstring>
95#include <limits>
96#include <map>
97#include <memory>
98#include <string>
99#include <system_error>
100#include <tuple>
101#include <utility>
102#include <vector>
103
104namespace llvm {
105
106static mc::RegisterMCTargetOptionsFlags MOF;
107
108namespace dsymutil {
109
110static Error copySwiftInterfaces(
111 const std::map<std::string, std::string> &ParseableSwiftInterfaces,
112 StringRef Architecture, const LinkOptions &Options) {
113 std::error_code EC;
114 SmallString<128> InputPath;
115 SmallString<128> Path;
116 sys::path::append(Path, *Options.ResourceDir, "Swift", Architecture);
117 if ((EC = sys::fs::create_directories(Path.str(), true,
118 sys::fs::perms::all_all)))
119 return make_error<StringError>(
120 "cannot create directory: " + toString(errorCodeToError(EC)), EC);
121 unsigned BaseLength = Path.size();
122
123 for (auto &I : ParseableSwiftInterfaces) {
124 StringRef ModuleName = I.first;
125 StringRef InterfaceFile = I.second;
126 if (!Options.PrependPath.empty()) {
127 InputPath.clear();
128 sys::path::append(InputPath, Options.PrependPath, InterfaceFile);
129 InterfaceFile = InputPath;
130 }
131 sys::path::append(Path, ModuleName);
132 Path.append(".swiftinterface");
133 if (Options.Verbose)
134 outs() << "copy parseable Swift interface " << InterfaceFile << " -> "
135 << Path.str() << '\n';
136
137 // copy_file attempts an APFS clone first, so this should be cheap.
138 if ((EC = sys::fs::copy_file(InterfaceFile, Path.str())))
139 warn(Twine("cannot copy parseable Swift interface ") + InterfaceFile +
140 ": " + toString(errorCodeToError(EC)));
141 Path.resize(BaseLength);
142 }
143 return Error::success();
144}
145
146/// Report a warning to the user, optionally including information about a
147/// specific \p DIE related to the warning.
148void DwarfLinkerForBinary::reportWarning(const Twine &Warning,
149 StringRef Context,
150 const DWARFDie *DIE) const {
151
152 warn(Warning, Context);
153
154 if (!Options.Verbose || !DIE)
155 return;
156
157 DIDumpOptions DumpOpts;
158 DumpOpts.ChildRecurseDepth = 0;
159 DumpOpts.Verbose = Options.Verbose;
160
161 WithColor::note() << " in DIE:\n";
162 DIE->dump(errs(), 6 /* Indent */, DumpOpts);
163}
164
165bool DwarfLinkerForBinary::createStreamer(const Triple &TheTriple,
166 raw_fd_ostream &OutFile) {
167 if (Options.NoOutput)
168 return true;
169
170 Streamer = std::make_unique<DwarfStreamer>(
171 Options.FileType, OutFile, Options.Translator,
172 [&](const Twine &Error, StringRef Context, const DWARFDie *) {
173 error(Error, Context);
174 },
175 [&](const Twine &Warning, StringRef Context, const DWARFDie *) {
176 warn(Warning, Context);
177 });
178 return Streamer->init(TheTriple, "__DWARF");
179}
180
181ErrorOr<const object::ObjectFile &>
182DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
183 const Triple &Triple) {
184 auto ObjectEntry =
185 BinHolder.getObjectEntry(Obj.getObjectFilename(), Obj.getTimestamp());
186 if (!ObjectEntry) {
3
←
Taking true branch
→
187 auto Err = ObjectEntry.takeError();
188 reportWarning(Twine(Obj.getObjectFilename()) + ": " +
189 toString(std::move(Err)),
4
←
Calling move constructor for 'Error'
→
6
←
Returning from move constructor for 'Error'
→
190 Obj.getObjectFilename());
191 return errorToErrorCode(std::move(Err));
7
←
Moved-from object 'Err' is moved
192 }
193
194 auto Object = ObjectEntry->getObject(Triple);
195 if (!Object) {
196 auto Err = Object.takeError();
197 reportWarning(Twine(Obj.getObjectFilename()) + ": " +
198 toString(std::move(Err)),
199 Obj.getObjectFilename());
200 return errorToErrorCode(std::move(Err));
201 }
202
203 return *Object;
204}
205
206static Error remarksErrorHandler(const DebugMapObject &DMO,
207 DwarfLinkerForBinary &Linker,
208 std::unique_ptr<FileError> FE) {
209 bool IsArchive = DMO.getObjectFilename().endswith(")");
210 // Don't report errors for missing remark files from static
211 // archives.
212 if (!IsArchive)
213 return Error(std::move(FE));
214
215 std::string Message = FE->message();
216 Error E = FE->takeError();
217 Error NewE = handleErrors(std::move(E), [&](std::unique_ptr<ECError> EC) {
218 if (EC->convertToErrorCode() != std::errc::no_such_file_or_directory)
219 return Error(std::move(EC));
220
221 Linker.reportWarning(Message, DMO.getObjectFilename());
222 return Error(Error::success());
223 });
224
225 if (!NewE)
226 return Error::success();
227
228 return createFileError(FE->getFileName(), std::move(NewE));
229}
230
231static Error emitRemarks(const LinkOptions &Options, StringRef BinaryPath,
232 StringRef ArchName, const remarks::RemarkLinker &RL) {
233 // Make sure we don't create the directories and the file if there is nothing
234 // to serialize.
235 if (RL.empty())
236 return Error::success();
237
238 SmallString<128> InputPath;
239 SmallString<128> Path;
240 // Create the "Remarks" directory in the "Resources" directory.
241 sys::path::append(Path, *Options.ResourceDir, "Remarks");
242 if (std::error_code EC = sys::fs::create_directories(Path.str(), true,
243 sys::fs::perms::all_all))
244 return errorCodeToError(EC);
245
246 // Append the file name.
247 // For fat binaries, also append a dash and the architecture name.
248 sys::path::append(Path, sys::path::filename(BinaryPath));
249 if (Options.NumDebugMaps > 1) {
250 // More than one debug map means we have a fat binary.
251 Path += '-';
252 Path += ArchName;
253 }
254
255 std::error_code EC;
256 raw_fd_ostream OS(Options.NoOutput ? "-" : Path.str(), EC,
257 Options.RemarksFormat == remarks::Format::Bitstream
258 ? sys::fs::OF_None
259 : sys::fs::OF_Text);
260 if (EC)
261 return errorCodeToError(EC);
262
263 if (Error E = RL.serialize(OS, Options.RemarksFormat))
264 return E;
265
266 return Error::success();
267}
268
269ErrorOr<DWARFFile &>
270DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
271 const DebugMap &DebugMap,
272 remarks::RemarkLinker &RL) {
273 auto ErrorOrObj = loadObject(Obj, DebugMap.getTriple());
2
←
Calling 'DwarfLinkerForBinary::loadObject'
→
274
275 if (ErrorOrObj) {
276 ContextForLinking.push_back(
277 std::unique_ptr<DWARFContext>(DWARFContext::create(*ErrorOrObj)));
278 AddressMapForLinking.push_back(
279 std::make_unique<AddressManager>(*this, *ErrorOrObj, Obj));
280
281 ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
282 Obj.getObjectFilename(), ContextForLinking.back().get(),
283 AddressMapForLinking.back().get(),
284 Obj.empty() ? Obj.getWarnings() : EmptyWarnings));
285
286 Error E = RL.link(*ErrorOrObj);
287 if (Error NewE = handleErrors(
288 std::move(E), [&](std::unique_ptr<FileError> EC) -> Error {
289 return remarksErrorHandler(Obj, *this, std::move(EC));
290 }))
291 return errorToErrorCode(std::move(NewE));
292
293 return *ObjectsForLinking.back();
294 }
295
296 return ErrorOrObj.getError();
297}
298
299static bool binaryHasStrippableSwiftReflectionSections(
300 const DebugMap &Map, const LinkOptions &Options, BinaryHolder &BinHolder) {
301 // If the input binary has strippable swift5 reflection sections, there is no
302 // need to copy them to the .dSYM. Only copy them for binaries where the
303 // linker omitted the reflection metadata.
304 if (!Map.getBinaryPath().empty() &&
305 Options.FileType == OutputFileType::Object) {
306
307 auto ObjectEntry = BinHolder.getObjectEntry(Map.getBinaryPath());
308 // If ObjectEntry or Object has an error, no binary exists, therefore no
309 // reflection sections exist.
310 if (!ObjectEntry) {
311 // Any errors will be diagnosed later in the main loop, ignore them here.
312 llvm::consumeError(ObjectEntry.takeError());
313 return false;
314 }
315
316 auto Object =
317 ObjectEntry->getObjectAs<object::MachOObjectFile>(Map.getTriple());
318 if (!Object) {
319 // Any errors will be diagnosed later in the main loop, ignore them here.
320 llvm::consumeError(Object.takeError());
321 return false;
322 }
323
324 for (auto &Section : Object->sections()) {
325 llvm::Expected<llvm::StringRef> NameOrErr =
326 Object->getSectionName(Section.getRawDataRefImpl());
327 if (!NameOrErr) {
328 llvm::consumeError(NameOrErr.takeError());
329 continue;
330 }
331 NameOrErr->consume_back("__TEXT");
332 auto ReflectionSectionKind =
333 Object->mapReflectionSectionNameToEnumValue(*NameOrErr);
334 if (Object->isReflectionSectionStrippable(ReflectionSectionKind)) {
335 return true;
336 }
337 }
338 }
339 return false;
340}
341
342/// Calculate the start of the strippable swift reflection sections in Dwarf.
343/// Note that there's an assumption that the reflection sections will appear
344/// in alphabetic order.
345static std::vector<uint64_t>
346calculateStartOfStrippableReflectionSections(const DebugMap &Map) {
347 using llvm::binaryformat::Swift5ReflectionSectionKind;
348 uint64_t AssocTySize = 0;
349 uint64_t FieldMdSize = 0;
350 for (const auto &Obj : Map.objects()) {
351 auto OF =
352 llvm::object::ObjectFile::createObjectFile(Obj->getObjectFilename());
353 if (!OF) {
354 llvm::consumeError(OF.takeError());
355 continue;
356 }
357 if (auto *MO = dyn_cast<llvm::object::MachOObjectFile>(OF->getBinary())) {
358 for (auto &Section : MO->sections()) {
359 llvm::Expected<llvm::StringRef> NameOrErr =
360 MO->getSectionName(Section.getRawDataRefImpl());
361 if (!NameOrErr) {
362 llvm::consumeError(NameOrErr.takeError());
363 continue;
364 }
365 NameOrErr->consume_back("__TEXT");
366 auto ReflSectionKind =
367 MO->mapReflectionSectionNameToEnumValue(*NameOrErr);
368 switch (ReflSectionKind) {
369 case Swift5ReflectionSectionKind::assocty:
370 AssocTySize += Section.getSize();
371 break;
372 case Swift5ReflectionSectionKind::fieldmd:
373 FieldMdSize += Section.getSize();
374 break;
375 default:
376 break;
377 }
378 }
379 }
380 }
381 // Initialize the vector with enough space to fit every reflection section
382 // kind.
383 std::vector<uint64_t> SectionToOffset(Swift5ReflectionSectionKind::last, 0);
384 SectionToOffset[Swift5ReflectionSectionKind::assocty] = 0;
385 SectionToOffset[Swift5ReflectionSectionKind::fieldmd] =
386 llvm::alignTo(AssocTySize, 4);
387 SectionToOffset[Swift5ReflectionSectionKind::reflstr] = llvm::alignTo(
388 SectionToOffset[Swift5ReflectionSectionKind::fieldmd] + FieldMdSize, 4);
389
390 return SectionToOffset;
391}
392
393void DwarfLinkerForBinary::collectRelocationsToApplyToSwiftReflectionSections(
394 const object::SectionRef &Section, StringRef &Contents,
395 const llvm::object::MachOObjectFile *MO,
396 const std::vector<uint64_t> &SectionToOffsetInDwarf,
397 const llvm::dsymutil::DebugMapObject *Obj,
398 std::vector<MachOUtils::DwarfRelocationApplicationInfo> &RelocationsToApply)
399 const {
400 for (auto It = Section.relocation_begin(); It != Section.relocation_end();
401 ++It) {
402 object::DataRefImpl RelocDataRef = It->getRawDataRefImpl();
403 MachO::any_relocation_info MachOReloc = MO->getRelocation(RelocDataRef);
404
405 if (!object::MachOObjectFile::isMachOPairedReloc(
406 MO->getAnyRelocationType(MachOReloc), MO->getArch())) {
407 reportWarning(
408 "Unimplemented relocation type in strippable reflection section ",
409 Obj->getObjectFilename());
410 continue;
411 }
412
413 auto CalculateAddressOfSymbolInDwarfSegment =
414 [&]() -> llvm::Optional<int64_t> {
415 auto Symbol = It->getSymbol();
416 auto SymbolAbsoluteAddress = Symbol->getAddress();
417 if (!SymbolAbsoluteAddress)
418 return {};
419 auto Section = Symbol->getSection();
420 if (!Section) {
421 llvm::consumeError(Section.takeError());
422 return {};
423 }
424
425 if ((*Section)->getObject()->section_end() == *Section)
426 return {};
427
428 auto SectionStart = (*Section)->getAddress();
429 auto SymbolAddressInSection = *SymbolAbsoluteAddress - SectionStart;
430 auto SectionName = (*Section)->getName();
431 if (!SectionName)
432 return {};
433 auto ReflSectionKind =
434 MO->mapReflectionSectionNameToEnumValue(*SectionName);
435
436 int64_t SectionStartInLinkedBinary =
437 SectionToOffsetInDwarf[ReflSectionKind];
438
439 auto Addr = SectionStartInLinkedBinary + SymbolAddressInSection;
440 return Addr;
441 };
442
443 // The first symbol should always be in the section we're currently
444 // iterating over.
445 auto FirstSymbolAddress = CalculateAddressOfSymbolInDwarfSegment();
446 ++It;
447
448 bool ShouldSubtractDwarfVM = false;
449 // For the second symbol there are two possibilities.
450 llvm::Optional<int64_t> SecondSymbolAddress;
451 auto Sym = It->getSymbol();
452 if (Sym != MO->symbol_end()) {
453 Expected<StringRef> SymbolName = Sym->getName();
454 if (SymbolName) {
455 if (const auto *Mapping = Obj->lookupSymbol(*SymbolName)) {
456 // First possibility: the symbol exists in the binary, and exists in a
457 // non-strippable section (for example, typeref, or __TEXT,__const),
458 // in which case we look up its address in the binary, which dsymutil
459 // will copy verbatim.
460 SecondSymbolAddress = Mapping->getValue().BinaryAddress;
461 // Since the symbols live in different segments, we have to substract
462 // the start of the Dwarf's vmaddr so the value calculated points to
463 // the correct place.
464 ShouldSubtractDwarfVM = true;
465 }
466 }
467 }
468
469 if (!SecondSymbolAddress) {
470 // Second possibility, this symbol is not present in the main binary, and
471 // must be in one of the strippable sections (for example, reflstr).
472 // Calculate its address in the same way as we did the first one.
473 SecondSymbolAddress = CalculateAddressOfSymbolInDwarfSegment();
474 }
475
476 if (!FirstSymbolAddress || !SecondSymbolAddress)
477 continue;
478
479 auto SectionName = Section.getName();
480 if (!SectionName)
481 continue;
482
483 int32_t Addend;
484 memcpy(&Addend, Contents.data() + It->getOffset(), sizeof(int32_t));
485 int32_t Value = (*SecondSymbolAddress + Addend) - *FirstSymbolAddress;
486 auto ReflSectionKind =
487 MO->mapReflectionSectionNameToEnumValue(*SectionName);
488 uint64_t AddressFromDwarfVM =
489 SectionToOffsetInDwarf[ReflSectionKind] + It->getOffset();
490 RelocationsToApply.emplace_back(AddressFromDwarfVM, Value,
491 ShouldSubtractDwarfVM);
492 }
493}
494
495void DwarfLinkerForBinary::copySwiftReflectionMetadata(
496 const llvm::dsymutil::DebugMapObject *Obj, DwarfStreamer *Streamer,
497 std::vector<uint64_t> &SectionToOffsetInDwarf,
498 std::vector<MachOUtils::DwarfRelocationApplicationInfo>
499 &RelocationsToApply) {
500 using binaryformat::Swift5ReflectionSectionKind;
501 auto OF =
502 llvm::object::ObjectFile::createObjectFile(Obj->getObjectFilename());
503 if (!OF) {
504 llvm::consumeError(OF.takeError());
505 return;
506 }
507 if (auto *MO = dyn_cast<llvm::object::MachOObjectFile>(OF->getBinary())) {
508 // Collect the swift reflection sections before emitting them. This is
509 // done so we control the order they're emitted.
510 std::array<Optional<object::SectionRef>,
511 Swift5ReflectionSectionKind::last + 1>
512 SwiftSections;
513 for (auto &Section : MO->sections()) {
514 llvm::Expected<llvm::StringRef> NameOrErr =
515 MO->getSectionName(Section.getRawDataRefImpl());
516 if (!NameOrErr) {
517 llvm::consumeError(NameOrErr.takeError());
518 continue;
519 }
520 NameOrErr->consume_back("__TEXT");
521 auto ReflSectionKind =
522 MO->mapReflectionSectionNameToEnumValue(*NameOrErr);
523 if (MO->isReflectionSectionStrippable(ReflSectionKind))
524 SwiftSections[ReflSectionKind] = Section;
525 }
526 // Make sure we copy the sections in alphabetic order.
527 auto SectionKindsToEmit = {Swift5ReflectionSectionKind::assocty,
528 Swift5ReflectionSectionKind::fieldmd,
529 Swift5ReflectionSectionKind::reflstr};
530 for (auto SectionKind : SectionKindsToEmit) {
531 if (!SwiftSections[SectionKind])
532 continue;
533 auto &Section = *SwiftSections[SectionKind];
534 llvm::Expected<llvm::StringRef> SectionContents = Section.getContents();
535 if (!SectionContents)
536 continue;
537 const auto *MO =
538 llvm::cast<llvm::object::MachOObjectFile>(Section.getObject());
539 collectRelocationsToApplyToSwiftReflectionSections(
540 Section, *SectionContents, MO, SectionToOffsetInDwarf, Obj,
541 RelocationsToApply);
542 // Update the section start with the current section's contribution, so
543 // the next section we copy from a different .o file points to the correct
544 // place.
545 SectionToOffsetInDwarf[SectionKind] += Section.getSize();
546 Streamer->emitSwiftReflectionSection(SectionKind, *SectionContents,
547 Section.getAlignment(),
548 Section.getSize());
549 }
550 }
551}
552
553bool DwarfLinkerForBinary::link(const DebugMap &Map) {
554 if (!createStreamer(Map.getTriple(), OutFile))
555 return false;
556
557 ObjectsForLinking.clear();
558 ContextForLinking.clear();
559 AddressMapForLinking.clear();
560
561 DebugMap DebugMap(Map.getTriple(), Map.getBinaryPath());
562
563 DWARFLinker GeneralLinker(Streamer.get(), DwarfLinkerClient::Dsymutil);
564
565 remarks::RemarkLinker RL;
566 if (!Options.RemarksPrependPath.empty())
567 RL.setExternalFilePrependPath(Options.RemarksPrependPath);
568 GeneralLinker.setObjectPrefixMap(&Options.ObjectPrefixMap);
569
570 std::function<StringRef(StringRef)> TranslationLambda = [&](StringRef Input) {
571 assert(Options.Translator)(static_cast <bool> (Options.Translator) ? void (0) : __assert_fail
("Options.Translator", "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp"
, 571, __extension__ __PRETTY_FUNCTION__));
572 return Options.Translator(Input);
573 };
574
575 GeneralLinker.setVerbosity(Options.Verbose);
576 GeneralLinker.setStatistics(Options.Statistics);
577 GeneralLinker.setVerifyInputDWARF(Options.VerifyInputDWARF);
578 GeneralLinker.setNoOutput(Options.NoOutput);
579 GeneralLinker.setNoODR(Options.NoODR);
580 GeneralLinker.setUpdate(Options.Update);
581 GeneralLinker.setNumThreads(Options.Threads);
582 GeneralLinker.setAccelTableKind(Options.TheAccelTableKind);
583 GeneralLinker.setPrependPath(Options.PrependPath);
584 GeneralLinker.setKeepFunctionForStatic(Options.KeepFunctionForStatic);
585 if (Options.Translator)
586 GeneralLinker.setStringsTranslator(TranslationLambda);
587 GeneralLinker.setWarningHandler(
588 [&](const Twine &Warning, StringRef Context, const DWARFDie *DIE) {
589 reportWarning(Warning, Context, DIE);
590 });
591 GeneralLinker.setErrorHandler(
592 [&](const Twine &Error, StringRef Context, const DWARFDie *) {
593 error(Error, Context);
594 });
595 GeneralLinker.setObjFileLoader(
596 [&DebugMap, &RL, this](StringRef ContainerName,
597 StringRef Path) -> ErrorOr<DWARFFile &> {
598 auto &Obj = DebugMap.addDebugMapObject(
599 Path, sys::TimePoint<std::chrono::seconds>(), MachO::N_OSO);
600
601 if (auto ErrorOrObj = loadObject(Obj, DebugMap, RL)) {
1
Calling 'DwarfLinkerForBinary::loadObject'
→
602 return *ErrorOrObj;
603 } else {
604 // Try and emit more helpful warnings by applying some heuristics.
605 StringRef ObjFile = ContainerName;
606 bool IsClangModule = sys::path::extension(Path).equals(".pcm");
607 bool IsArchive = ObjFile.endswith(")");
608
609 if (IsClangModule) {
610 StringRef ModuleCacheDir = sys::path::parent_path(Path);
611 if (sys::fs::exists(ModuleCacheDir)) {
612 // If the module's parent directory exists, we assume that the
613 // module cache has expired and was pruned by clang. A more
614 // adventurous dsymutil would invoke clang to rebuild the module
615 // now.
616 if (!ModuleCacheHintDisplayed) {
617 WithColor::note()
618 << "The clang module cache may have expired since "
619 "this object file was built. Rebuilding the "
620 "object file will rebuild the module cache.\n";
621 ModuleCacheHintDisplayed = true;
622 }
623 } else if (IsArchive) {
624 // If the module cache directory doesn't exist at all and the
625 // object file is inside a static library, we assume that the
626 // static library was built on a different machine. We don't want
627 // to discourage module debugging for convenience libraries within
628 // a project though.
629 if (!ArchiveHintDisplayed) {
630 WithColor::note()
631 << "Linking a static library that was built with "
632 "-gmodules, but the module cache was not found. "
633 "Redistributable static libraries should never be "
634 "built with module debugging enabled. The debug "
635 "experience will be degraded due to incomplete "
636 "debug information.\n";
637 ArchiveHintDisplayed = true;
638 }
639 }
640 }
641
642 return ErrorOrObj.getError();
643 }
644
645 llvm_unreachable("Unhandled DebugMap object")::llvm::llvm_unreachable_internal("Unhandled DebugMap object"
, "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp", 645);
646 });
647 GeneralLinker.setSwiftInterfacesMap(&ParseableSwiftInterfaces);
648 bool ReflectionSectionsPresentInBinary = false;
649 // If there is no output specified, no point in checking the binary for swift5
650 // reflection sections.
651 if (!Options.NoOutput) {
652 ReflectionSectionsPresentInBinary =
653 binaryHasStrippableSwiftReflectionSections(Map, Options, BinHolder);
654 }
655
656 std::vector<MachOUtils::DwarfRelocationApplicationInfo> RelocationsToApply;
657 if (!Options.NoOutput && !ReflectionSectionsPresentInBinary) {
658 auto SectionToOffsetInDwarf =
659 calculateStartOfStrippableReflectionSections(Map);
660 for (const auto &Obj : Map.objects())
661 copySwiftReflectionMetadata(Obj.get(), Streamer.get(),
662 SectionToOffsetInDwarf, RelocationsToApply);
663 }
664
665 for (const auto &Obj : Map.objects()) {
666 // N_AST objects (swiftmodule files) should get dumped directly into the
667 // appropriate DWARF section.
668 if (Obj->getType() == MachO::N_AST) {
669 if (Options.Verbose)
670 outs() << "DEBUG MAP OBJECT: " << Obj->getObjectFilename() << "\n";
671
672 StringRef File = Obj->getObjectFilename();
673 auto ErrorOrMem = MemoryBuffer::getFile(File);
674 if (!ErrorOrMem) {
675 warn("Could not open '" + File + "'\n");
676 continue;
677 }
678 sys::fs::file_status Stat;
679 if (auto Err = sys::fs::status(File, Stat)) {
680 warn(Err.message());
681 continue;
682 }
683 if (!Options.NoTimestamp) {
684 // The modification can have sub-second precision so we need to cast
685 // away the extra precision that's not present in the debug map.
686 auto ModificationTime =
687 std::chrono::time_point_cast<std::chrono::seconds>(
688 Stat.getLastModificationTime());
689 if (Obj->getTimestamp() != sys::TimePoint<>() &&
690 ModificationTime != Obj->getTimestamp()) {
691 // Not using the helper here as we can easily stream TimePoint<>.
692 WithColor::warning()
693 << File << ": timestamp mismatch between swift interface file ("
694 << sys::TimePoint<>(ModificationTime) << ") and debug map ("
695 << sys::TimePoint<>(Obj->getTimestamp()) << ")\n";
696 continue;
697 }
698 }
699
700 // Copy the module into the .swift_ast section.
701 if (!Options.NoOutput)
702 Streamer->emitSwiftAST((*ErrorOrMem)->getBuffer());
703
704 continue;
705 }
706 if (auto ErrorOrObj = loadObject(*Obj, Map, RL))
707 GeneralLinker.addObjectFile(*ErrorOrObj);
708 else {
709 ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
710 Obj->getObjectFilename(), nullptr, nullptr,
711 Obj->empty() ? Obj->getWarnings() : EmptyWarnings));
712 GeneralLinker.addObjectFile(*ObjectsForLinking.back());
713 }
714 }
715
716 // link debug info for loaded object files.
717 GeneralLinker.link();
718
719 StringRef ArchName = Map.getTriple().getArchName();
720 if (Error E = emitRemarks(Options, Map.getBinaryPath(), ArchName, RL))
721 return error(toString(std::move(E)));
722
723 if (Options.NoOutput)
724 return true;
725
726 if (Options.ResourceDir && !ParseableSwiftInterfaces.empty()) {
727 StringRef ArchName = Triple::getArchTypeName(Map.getTriple().getArch());
728 if (auto E =
729 copySwiftInterfaces(ParseableSwiftInterfaces, ArchName, Options))
730 return error(toString(std::move(E)));
731 }
732
733 if (Map.getTriple().isOSDarwin() && !Map.getBinaryPath().empty() &&
734 Options.FileType == OutputFileType::Object)
735 return MachOUtils::generateDsymCompanion(
736 Options.VFS, Map, Options.Translator,
737 *Streamer->getAsmPrinter().OutStreamer, OutFile, RelocationsToApply);
738
739 Streamer->finish();
740 return true;
741}
742
743/// Iterate over the relocations of the given \p Section and
744/// store the ones that correspond to debug map entries into the
745/// ValidRelocs array.
746void DwarfLinkerForBinary::AddressManager::findValidRelocsMachO(
747 const object::SectionRef &Section, const object::MachOObjectFile &Obj,
748 const DebugMapObject &DMO, std::vector<ValidReloc> &ValidRelocs) {
749 Expected<StringRef> ContentsOrErr = Section.getContents();
750 if (!ContentsOrErr) {
751 consumeError(ContentsOrErr.takeError());
752 Linker.reportWarning("error reading section", DMO.getObjectFilename());
753 return;
754 }
755 DataExtractor Data(*ContentsOrErr, Obj.isLittleEndian(), 0);
756 bool SkipNext = false;
757
758 for (const object::RelocationRef &Reloc : Section.relocations()) {
759 if (SkipNext) {
760 SkipNext = false;
761 continue;
762 }
763
764 object::DataRefImpl RelocDataRef = Reloc.getRawDataRefImpl();
765 MachO::any_relocation_info MachOReloc = Obj.getRelocation(RelocDataRef);
766
767 if (object::MachOObjectFile::isMachOPairedReloc(Obj.getAnyRelocationType(MachOReloc),
768 Obj.getArch())) {
769 SkipNext = true;
770 Linker.reportWarning("unsupported relocation in " + *Section.getName() +
771 " section.",
772 DMO.getObjectFilename());
773 continue;
774 }
775
776 unsigned RelocSize = 1 << Obj.getAnyRelocationLength(MachOReloc);
777 uint64_t Offset64 = Reloc.getOffset();
778 if ((RelocSize != 4 && RelocSize != 8)) {
779 Linker.reportWarning("unsupported relocation in " + *Section.getName() +
780 " section.",
781 DMO.getObjectFilename());
782 continue;
783 }
784 uint64_t OffsetCopy = Offset64;
785 // Mach-o uses REL relocations, the addend is at the relocation offset.
786 uint64_t Addend = Data.getUnsigned(&OffsetCopy, RelocSize);
787 uint64_t SymAddress;
788 int64_t SymOffset;
789
790 if (Obj.isRelocationScattered(MachOReloc)) {
791 // The address of the base symbol for scattered relocations is
792 // stored in the reloc itself. The actual addend will store the
793 // base address plus the offset.
794 SymAddress = Obj.getScatteredRelocationValue(MachOReloc);
795 SymOffset = int64_t(Addend) - SymAddress;
796 } else {
797 SymAddress = Addend;
798 SymOffset = 0;
799 }
800
801 auto Sym = Reloc.getSymbol();
802 if (Sym != Obj.symbol_end()) {
803 Expected<StringRef> SymbolName = Sym->getName();
804 if (!SymbolName) {
805 consumeError(SymbolName.takeError());
806 Linker.reportWarning("error getting relocation symbol name.",
807 DMO.getObjectFilename());
808 continue;
809 }
810 if (const auto *Mapping = DMO.lookupSymbol(*SymbolName))
811 ValidRelocs.emplace_back(Offset64, RelocSize, Addend, Mapping);
812 } else if (const auto *Mapping = DMO.lookupObjectAddress(SymAddress)) {
813 // Do not store the addend. The addend was the address of the symbol in
814 // the object file, the address in the binary that is stored in the debug
815 // map doesn't need to be offset.
816 ValidRelocs.emplace_back(Offset64, RelocSize, SymOffset, Mapping);
817 }
818 }
819}
820
821/// Dispatch the valid relocation finding logic to the
822/// appropriate handler depending on the object file format.
823bool DwarfLinkerForBinary::AddressManager::findValidRelocs(
824 const object::SectionRef &Section, const object::ObjectFile &Obj,
825 const DebugMapObject &DMO, std::vector<ValidReloc> &Relocs) {
826 // Dispatch to the right handler depending on the file type.
827 if (auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Obj))
828 findValidRelocsMachO(Section, *MachOObj, DMO, Relocs);
829 else
830 Linker.reportWarning(Twine("unsupported object file type: ") +
831 Obj.getFileName(),
832 DMO.getObjectFilename());
833 if (Relocs.empty())
834 return false;
835
836 // Sort the relocations by offset. We will walk the DIEs linearly in
837 // the file, this allows us to just keep an index in the relocation
838 // array that we advance during our walk, rather than resorting to
839 // some associative container. See DwarfLinkerForBinary::NextValidReloc.
840 llvm::sort(Relocs);
841 return true;
842}
843
844/// Look for relocations in the debug_info and debug_addr section that match
845/// entries in the debug map. These relocations will drive the Dwarf link by
846/// indicating which DIEs refer to symbols present in the linked binary.
847/// \returns whether there are any valid relocations in the debug info.
848bool DwarfLinkerForBinary::AddressManager::findValidRelocsInDebugSections(
849 const object::ObjectFile &Obj, const DebugMapObject &DMO) {
850 // Find the debug_info section.
851 bool FoundValidRelocs = false;
852 for (const object::SectionRef &Section : Obj.sections()) {
853 StringRef SectionName;
854 if (Expected<StringRef> NameOrErr = Section.getName())
855 SectionName = *NameOrErr;
856 else
857 consumeError(NameOrErr.takeError());
858
859 SectionName = SectionName.substr(SectionName.find_first_not_of("._"));
860 if (SectionName == "debug_info")
861 FoundValidRelocs |=
862 findValidRelocs(Section, Obj, DMO, ValidDebugInfoRelocs);
863 if (SectionName == "debug_addr")
864 FoundValidRelocs |=
865 findValidRelocs(Section, Obj, DMO, ValidDebugAddrRelocs);
866 }
867 return FoundValidRelocs;
868}
869
870std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc>
871DwarfLinkerForBinary::AddressManager::getRelocations(
872 const std::vector<ValidReloc> &Relocs, uint64_t StartPos, uint64_t EndPos) {
873 std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc> Res;
874
875 auto CurReloc = partition_point(Relocs, [StartPos](const ValidReloc &Reloc) {
876 return Reloc.Offset < StartPos;
877 });
878
879 while (CurReloc != Relocs.end() && CurReloc->Offset >= StartPos &&
880 CurReloc->Offset < EndPos) {
881 Res.push_back(*CurReloc);
882 CurReloc++;
883 }
884
885 return Res;
886}
887
888void DwarfLinkerForBinary::AddressManager::printReloc(const ValidReloc &Reloc) {
889 const auto &Mapping = Reloc.Mapping->getValue();
890 const uint64_t ObjectAddress = Mapping.ObjectAddress
891 ? uint64_t(*Mapping.ObjectAddress)
892 : std::numeric_limits<uint64_t>::max();
893
894 outs() << "Found valid debug map entry: " << Reloc.Mapping->getKey() << "\t"
895 << format("0x%016" PRIx64"l" "x" " => 0x%016" PRIx64"l" "x" "\n", ObjectAddress,
896 uint64_t(Mapping.BinaryAddress));
897}
898
899void DwarfLinkerForBinary::AddressManager::fillDieInfo(
900 const ValidReloc &Reloc, CompileUnit::DIEInfo &Info) {
901 Info.AddrAdjust = relocate(Reloc);
902 if (Reloc.Mapping->getValue().ObjectAddress)
903 Info.AddrAdjust -= uint64_t(*Reloc.Mapping->getValue().ObjectAddress);
904 Info.InDebugMap = true;
905}
906
907bool DwarfLinkerForBinary::AddressManager::hasValidRelocationAt(
908 const std::vector<ValidReloc> &AllRelocs, uint64_t StartOffset,
909 uint64_t EndOffset, CompileUnit::DIEInfo &Info) {
910 std::vector<ValidReloc> Relocs =
911 getRelocations(AllRelocs, StartOffset, EndOffset);
912
913 if (Relocs.size() == 0)
914 return false;
915
916 if (Linker.Options.Verbose)
917 printReloc(Relocs[0]);
918 fillDieInfo(Relocs[0], Info);
919
920 return true;
921}
922
923/// Get the starting and ending (exclusive) offset for the
924/// attribute with index \p Idx descibed by \p Abbrev. \p Offset is
925/// supposed to point to the position of the first attribute described
926/// by \p Abbrev.
927/// \return [StartOffset, EndOffset) as a pair.
928static std::pair<uint64_t, uint64_t>
929getAttributeOffsets(const DWARFAbbreviationDeclaration *Abbrev, unsigned Idx,
930 uint64_t Offset, const DWARFUnit &Unit) {
931 DataExtractor Data = Unit.getDebugInfoExtractor();
932
933 for (unsigned I = 0; I < Idx; ++I)
934 DWARFFormValue::skipValue(Abbrev->getFormByIndex(I), Data, &Offset,
935 Unit.getFormParams());
936
937 uint64_t End = Offset;
938 DWARFFormValue::skipValue(Abbrev->getFormByIndex(Idx), Data, &End,
939 Unit.getFormParams());
940
941 return std::make_pair(Offset, End);
942}
943
944bool DwarfLinkerForBinary::AddressManager::hasLiveMemoryLocation(
945 const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
946 const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
947
948 Optional<uint32_t> LocationIdx =
949 Abbrev->findAttributeIndex(dwarf::DW_AT_location);
950 if (!LocationIdx)
951 return false;
952
953 uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
954 uint64_t LocationOffset, LocationEndOffset;
955 std::tie(LocationOffset, LocationEndOffset) =
956 getAttributeOffsets(Abbrev, *LocationIdx, Offset, *DIE.getDwarfUnit());
957
958 // FIXME: Support relocations debug_addr.
959 return hasValidRelocationAt(ValidDebugInfoRelocs, LocationOffset,
960 LocationEndOffset, MyInfo);
961}
962
963bool DwarfLinkerForBinary::AddressManager::hasLiveAddressRange(
964 const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
965 const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
966
967 Optional<uint32_t> LowPcIdx = Abbrev->findAttributeIndex(dwarf::DW_AT_low_pc);
968 if (!LowPcIdx)
969 return false;
970
971 dwarf::Form Form = Abbrev->getFormByIndex(*LowPcIdx);
972
973 if (Form == dwarf::DW_FORM_addr) {
974 uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
975 uint64_t LowPcOffset, LowPcEndOffset;
976 std::tie(LowPcOffset, LowPcEndOffset) =
977 getAttributeOffsets(Abbrev, *LowPcIdx, Offset, *DIE.getDwarfUnit());
978 return hasValidRelocationAt(ValidDebugInfoRelocs, LowPcOffset,
979 LowPcEndOffset, MyInfo);
980 }
981
982 if (Form == dwarf::DW_FORM_addrx) {
983 Optional<DWARFFormValue> AddrValue = DIE.find(dwarf::DW_AT_low_pc);
984 if (Optional<uint64_t> AddrOffsetSectionBase =
985 DIE.getDwarfUnit()->getAddrOffsetSectionBase()) {
986 uint64_t StartOffset = *AddrOffsetSectionBase + AddrValue->getRawUValue();
987 uint64_t EndOffset =
988 StartOffset + DIE.getDwarfUnit()->getAddressByteSize();
989 return hasValidRelocationAt(ValidDebugAddrRelocs, StartOffset, EndOffset,
990 MyInfo);
991 } else
992 Linker.reportWarning("no base offset for address table", SrcFileName);
993 }
994
995 return false;
996}
997
998uint64_t
999DwarfLinkerForBinary::AddressManager::relocate(const ValidReloc &Reloc) const {
1000 return Reloc.Mapping->getValue().BinaryAddress + Reloc.Addend;
1001}
1002
1003/// Apply the valid relocations found by findValidRelocs() to
1004/// the buffer \p Data, taking into account that Data is at \p BaseOffset
1005/// in the debug_info section.
1006///
1007/// Like for findValidRelocs(), this function must be called with
1008/// monotonic \p BaseOffset values.
1009///
1010/// \returns whether any reloc has been applied.
1011bool DwarfLinkerForBinary::AddressManager::applyValidRelocs(
1012 MutableArrayRef<char> Data, uint64_t BaseOffset, bool IsLittleEndian) {
1013 assert(areRelocationsResolved())(static_cast <bool> (areRelocationsResolved()) ? void (
0) : __assert_fail ("areRelocationsResolved()", "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp"
, 1013, __extension__ __PRETTY_FUNCTION__));
1014 std::vector<ValidReloc> Relocs = getRelocations(
1015 ValidDebugInfoRelocs, BaseOffset, BaseOffset + Data.size());
1016
1017 for (const ValidReloc &CurReloc : Relocs) {
1018 assert(CurReloc.Offset - BaseOffset < Data.size())(static_cast <bool> (CurReloc.Offset - BaseOffset < Data
.size()) ? void (0) : __assert_fail ("CurReloc.Offset - BaseOffset < Data.size()"
, "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp", 1018, __extension__
__PRETTY_FUNCTION__));
1019 assert(CurReloc.Offset - BaseOffset + CurReloc.Size <= Data.size())(static_cast <bool> (CurReloc.Offset - BaseOffset + CurReloc
.Size <= Data.size()) ? void (0) : __assert_fail ("CurReloc.Offset - BaseOffset + CurReloc.Size <= Data.size()"
, "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp", 1019, __extension__
__PRETTY_FUNCTION__));
1020 char Buf[8];
1021 uint64_t Value = relocate(CurReloc);
1022 for (unsigned I = 0; I != CurReloc.Size; ++I) {
1023 unsigned Index = IsLittleEndian ? I : (CurReloc.Size - I - 1);
1024 Buf[I] = uint8_t(Value >> (Index * 8));
1025 }
1026 assert(CurReloc.Size <= sizeof(Buf))(static_cast <bool> (CurReloc.Size <= sizeof(Buf)) ?
void (0) : __assert_fail ("CurReloc.Size <= sizeof(Buf)",
"llvm/tools/dsymutil/DwarfLinkerForBinary.cpp", 1026, __extension__
__PRETTY_FUNCTION__));
1027 memcpy(&Data[CurReloc.Offset - BaseOffset], Buf, CurReloc.Size);
1028 }
1029
1030 return Relocs.size() > 0;
1031}
1032
1033llvm::Expected<uint64_t>
1034DwarfLinkerForBinary::AddressManager::relocateIndexedAddr(uint64_t StartOffset,
1035 uint64_t EndOffset) {
1036 std::vector<ValidReloc> Relocs =
1037 getRelocations(ValidDebugAddrRelocs, StartOffset, EndOffset);
1038 if (Relocs.size() == 0)
1039 return createStringError(
1040 std::make_error_code(std::errc::invalid_argument),
1041 "no relocation for offset %llu in debug_addr section", StartOffset);
1042
1043 return relocate(Relocs[0]);
1044}
1045
1046bool linkDwarf(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
1047 const DebugMap &DM, LinkOptions Options) {
1048 DwarfLinkerForBinary Linker(OutFile, BinHolder, std::move(Options));
1049 return Linker.link(DM);
1050}
1051
1052} // namespace dsymutil
1053} // namespace llvm
←

/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/StringExtras.h"
19#include "llvm/ADT/Twine.h"
20#include "llvm/Config/abi-breaking.h"
21#include "llvm/Support/AlignOf.h"
22#include "llvm/Support/Compiler.h"
23#include "llvm/Support/Debug.h"
24#include "llvm/Support/ErrorHandling.h"
25#include "llvm/Support/ErrorOr.h"
26#include "llvm/Support/Format.h"
27#include "llvm/Support/raw_ostream.h"
28#include <cassert>
29#include <cstdint>
30#include <cstdlib>
31#include <functional>
32#include <memory>
33#include <new>
34#include <string>
35#include <system_error>
36#include <type_traits>
37#include <utility>
38#include <vector>
39
40namespace llvm {
41
42class ErrorSuccess;
43
44/// Base class for error info classes. Do not extend this directly: Extend
45/// the ErrorInfo template subclass instead.
46class ErrorInfoBase {
47public:
48 virtual ~ErrorInfoBase() = default;
49
50 /// Print an error message to an output stream.
51 virtual void log(raw_ostream &OS) const = 0;
52
53 /// Return the error message as a string.
54 virtual std::string message() const {
55 std::string Msg;
56 raw_string_ostream OS(Msg);
57 log(OS);
58 return OS.str();
59 }
60
61 /// Convert this error to a std::error_code.
62 ///
63 /// This is a temporary crutch to enable interaction with code still
64 /// using std::error_code. It will be removed in the future.
65 virtual std::error_code convertToErrorCode() const = 0;
66
67 // Returns the class ID for this type.
68 static const void *classID() { return &ID; }
69
70 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
71 virtual const void *dynamicClassID() const = 0;
72
73 // Check whether this instance is a subclass of the class identified by
74 // ClassID.
75 virtual bool isA(const void *const ClassID) const {
76 return ClassID == classID();
77 }
78
79 // Check whether this instance is a subclass of ErrorInfoT.
80 template <typename ErrorInfoT> bool isA() const {
81 return isA(ErrorInfoT::classID());
82 }
83
84private:
85 virtual void anchor();
86
87 static char ID;
88};
89
90/// Lightweight error class with error context and mandatory checking.
91///
92/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
93/// are represented by setting the pointer to a ErrorInfoBase subclass
94/// instance containing information describing the failure. Success is
95/// represented by a null pointer value.
96///
97/// Instances of Error also contains a 'Checked' flag, which must be set
98/// before the destructor is called, otherwise the destructor will trigger a
99/// runtime error. This enforces at runtime the requirement that all Error
100/// instances be checked or returned to the caller.
101///
102/// There are two ways to set the checked flag, depending on what state the
103/// Error instance is in. For Error instances indicating success, it
104/// is sufficient to invoke the boolean conversion operator. E.g.:
105///
106/// @code{.cpp}
107/// Error foo(<...>);
108///
109/// if (auto E = foo(<...>))
110/// return E; // <- Return E if it is in the error state.
111/// // We have verified that E was in the success state. It can now be safely
112/// // destroyed.
113/// @endcode
114///
115/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
116/// without testing the return value will raise a runtime error, even if foo
117/// returns success.
118///
119/// For Error instances representing failure, you must use either the
120/// handleErrors or handleAllErrors function with a typed handler. E.g.:
121///
122/// @code{.cpp}
123/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
124/// // Custom error info.
125/// };
126///
127/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
128///
129/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
130/// auto NewE =
131/// handleErrors(E,
132/// [](const MyErrorInfo &M) {
133/// // Deal with the error.
134/// },
135/// [](std::unique_ptr<OtherError> M) -> Error {
136/// if (canHandle(*M)) {
137/// // handle error.
138/// return Error::success();
139/// }
140/// // Couldn't handle this error instance. Pass it up the stack.
141/// return Error(std::move(M));
142/// );
143/// // Note - we must check or return NewE in case any of the handlers
144/// // returned a new error.
145/// @endcode
146///
147/// The handleAllErrors function is identical to handleErrors, except
148/// that it has a void return type, and requires all errors to be handled and
149/// no new errors be returned. It prevents errors (assuming they can all be
150/// handled) from having to be bubbled all the way to the top-level.
151///
152/// *All* Error instances must be checked before destruction, even if
153/// they're moved-assigned or constructed from Success values that have already
154/// been checked. This enforces checking through all levels of the call stack.
155class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
156 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
157 // to add to the error list. It can't rely on handleErrors for this, since
158 // handleErrors does not support ErrorList handlers.
159 friend class ErrorList;
160
161 // handleErrors needs to be able to set the Checked flag.
162 template <typename... HandlerTs>
163 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
164
165 // Expected<T> needs to be able to steal the payload when constructed from an
166 // error.
167 template <typename T> friend class Expected;
168
169 // wrap needs to be able to steal the payload.
170 friend LLVMErrorRef wrap(Error);
171
172protected:
173 /// Create a success value. Prefer using 'Error::success()' for readability
174 Error() {
175 setPtr(nullptr);
176 setChecked(false);
177 }
178
179public:
180 /// Create a success value.
181 static ErrorSuccess success();
182
183 // Errors are not copy-constructable.
184 Error(const Error &Other) = delete;
185
186 /// Move-construct an error value. The newly constructed error is considered
187 /// unchecked, even if the source error had been checked. The original error
188 /// becomes a checked Success value, regardless of its original state.
189 Error(Error &&Other) {
190 setChecked(true);
191 *this = std::move(Other);
5
←
Object 'Err' is moved
→
192 }
193
194 /// Create an error value. Prefer using the 'make_error' function, but
195 /// this constructor can be useful when "re-throwing" errors from handlers.
196 Error(std::unique_ptr<ErrorInfoBase> Payload) {
197 setPtr(Payload.release());
198 setChecked(false);
199 }
200
201 // Errors are not copy-assignable.
202 Error &operator=(const Error &Other) = delete;
203
204 /// Move-assign an error value. The current error must represent success, you
205 /// you cannot overwrite an unhandled error. The current error is then
206 /// considered unchecked. The source error becomes a checked success value,
207 /// regardless of its original state.
208 Error &operator=(Error &&Other) {
209 // Don't allow overwriting of unchecked values.
210 assertIsChecked();
211 setPtr(Other.getPtr());
212
213 // This Error is unchecked, even if the source error was checked.
214 setChecked(false);
215
216 // Null out Other's payload and set its checked bit.
217 Other.setPtr(nullptr);
218 Other.setChecked(true);
219
220 return *this;
221 }
222
223 /// Destroy a Error. Fails with a call to abort() if the error is
224 /// unchecked.
225 ~Error() {
226 assertIsChecked();
227 delete getPtr();
228 }
229
230 /// Bool conversion. Returns true if this Error is in a failure state,
231 /// and false if it is in an accept state. If the error is in a Success state
232 /// it will be considered checked.
233 explicit operator bool() {
234 setChecked(getPtr() == nullptr);
235 return getPtr() != nullptr;
236 }
237
238 /// Check whether one error is a subclass of another.
239 template <typename ErrT> bool isA() const {
240 return getPtr() && getPtr()->isA(ErrT::classID());
241 }
242
243 /// Returns the dynamic class id of this error, or null if this is a success
244 /// value.
245 const void* dynamicClassID() const {
246 if (!getPtr())
247 return nullptr;
248 return getPtr()->dynamicClassID();
249 }
250
251private:
252#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
253 // assertIsChecked() happens very frequently, but under normal circumstances
254 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
255 // of debug prints can cause the function to be too large for inlining. So
256 // it's important that we define this function out of line so that it can't be
257 // inlined.
258 [[noreturn]] void fatalUncheckedError() const;
259#endif
260
261 void assertIsChecked() {
262#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
263 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
264 fatalUncheckedError();
265#endif
266 }
267
268 ErrorInfoBase *getPtr() const {
269#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
270 return reinterpret_cast<ErrorInfoBase*>(
271 reinterpret_cast<uintptr_t>(Payload) &
272 ~static_cast<uintptr_t>(0x1));
273#else
274 return Payload;
275#endif
276 }
277
278 void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280 Payload = reinterpret_cast<ErrorInfoBase*>(
281 (reinterpret_cast<uintptr_t>(EI) &
282 ~static_cast<uintptr_t>(0x1)) |
283 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285 Payload = EI;
286#endif
287 }
288
289 bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293 return true;
294#endif
295 }
296
297 void setChecked(bool V) {
298#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
299 Payload = reinterpret_cast<ErrorInfoBase*>(
300 (reinterpret_cast<uintptr_t>(Payload) &
301 ~static_cast<uintptr_t>(0x1)) |
302 (V ? 0 : 1));
303#endif
304 }
305
306 std::unique_ptr<ErrorInfoBase> takePayload() {
307 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
308 setPtr(nullptr);
309 setChecked(true);
310 return Tmp;
311 }
312
313 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
314 if (auto *P = E.getPtr())
315 P->log(OS);
316 else
317 OS << "success";
318 return OS;
319 }
320
321 ErrorInfoBase *Payload = nullptr;
322};
323
324/// Subclass of Error for the sole purpose of identifying the success path in
325/// the type system. This allows to catch invalid conversion to Expected<T> at
326/// compile time.
327class ErrorSuccess final : public Error {};
328
329inline ErrorSuccess Error::success() { return ErrorSuccess(); }
330
331/// Make a Error instance representing failure using the given error info
332/// type.
333template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
334 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
335}
336
337/// Base class for user error types. Users should declare their error types
338/// like:
339///
340/// class MyError : public ErrorInfo<MyError> {
341/// ....
342/// };
343///
344/// This class provides an implementation of the ErrorInfoBase::kind
345/// method, which is used by the Error RTTI system.
346template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
347class ErrorInfo : public ParentErrT {
348public:
349 using ParentErrT::ParentErrT; // inherit constructors
350
351 static const void *classID() { return &ThisErrT::ID; }
352
353 const void *dynamicClassID() const override { return &ThisErrT::ID; }
354
355 bool isA(const void *const ClassID) const override {
356 return ClassID == classID() || ParentErrT::isA(ClassID);
357 }
358};
359
360/// Special ErrorInfo subclass representing a list of ErrorInfos.
361/// Instances of this class are constructed by joinError.
362class ErrorList final : public ErrorInfo<ErrorList> {
363 // handleErrors needs to be able to iterate the payload list of an
364 // ErrorList.
365 template <typename... HandlerTs>
366 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
367
368 // joinErrors is implemented in terms of join.
369 friend Error joinErrors(Error, Error);
370
371public:
372 void log(raw_ostream &OS) const override {
373 OS << "Multiple errors:\n";
374 for (const auto &ErrPayload : Payloads) {
375 ErrPayload->log(OS);
376 OS << "\n";
377 }
378 }
379
380 std::error_code convertToErrorCode() const override;
381
382 // Used by ErrorInfo::classID.
383 static char ID;
384
385private:
386 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
387 std::unique_ptr<ErrorInfoBase> Payload2) {
388 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "llvm/include/llvm/Support/Error.h", 389, __extension__ __PRETTY_FUNCTION__
))
389 "ErrorList constructor payloads should be singleton errors")(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "llvm/include/llvm/Support/Error.h", 389, __extension__ __PRETTY_FUNCTION__
));
390 Payloads.push_back(std::move(Payload1));
391 Payloads.push_back(std::move(Payload2));
392 }
393
394 static Error join(Error E1, Error E2) {
395 if (!E1)
396 return E2;
397 if (!E2)
398 return E1;
399 if (E1.isA<ErrorList>()) {
400 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
401 if (E2.isA<ErrorList>()) {
402 auto E2Payload = E2.takePayload();
403 auto &E2List = static_cast<ErrorList &>(*E2Payload);
404 for (auto &Payload : E2List.Payloads)
405 E1List.Payloads.push_back(std::move(Payload));
406 } else
407 E1List.Payloads.push_back(E2.takePayload());
408
409 return E1;
410 }
411 if (E2.isA<ErrorList>()) {
412 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
413 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
414 return E2;
415 }
416 return Error(std::unique_ptr<ErrorList>(
417 new ErrorList(E1.takePayload(), E2.takePayload())));
418 }
419
420 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
421};
422
423/// Concatenate errors. The resulting Error is unchecked, and contains the
424/// ErrorInfo(s), if any, contained in E1, followed by the
425/// ErrorInfo(s), if any, contained in E2.
426inline Error joinErrors(Error E1, Error E2) {
427 return ErrorList::join(std::move(E1), std::move(E2));
428}
429
430/// Tagged union holding either a T or a Error.
431///
432/// This class parallels ErrorOr, but replaces error_code with Error. Since
433/// Error cannot be copied, this class replaces getError() with
434/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
435/// error class type.
436///
437/// Example usage of 'Expected<T>' as a function return type:
438///
439/// @code{.cpp}
440/// Expected<int> myDivide(int A, int B) {
441/// if (B == 0) {
442/// // return an Error
443/// return createStringError(inconvertibleErrorCode(),
444/// "B must not be zero!");
445/// }
446/// // return an integer
447/// return A / B;
448/// }
449/// @endcode
450///
451/// Checking the results of to a function returning 'Expected<T>':
452/// @code{.cpp}
453/// if (auto E = Result.takeError()) {
454/// // We must consume the error. Typically one of:
455/// // - return the error to our caller
456/// // - toString(), when logging
457/// // - consumeError(), to silently swallow the error
458/// // - handleErrors(), to distinguish error types
459/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
460/// return;
461/// }
462/// // use the result
463/// outs() << "The answer is " << *Result << "\n";
464/// @endcode
465///
466/// For unit-testing a function returning an 'Expceted<T>', see the
467/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
468
469template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
470 template <class T1> friend class ExpectedAsOutParameter;
471 template <class OtherT> friend class Expected;
472
473 static constexpr bool isRef = std::is_reference<T>::value;
474
475 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
476
477 using error_type = std::unique_ptr<ErrorInfoBase>;
478
479public:
480 using storage_type = std::conditional_t<isRef, wrap, T>;
481 using value_type = T;
482
483private:
484 using reference = std::remove_reference_t<T> &;
485 using const_reference = const std::remove_reference_t<T> &;
486 using pointer = std::remove_reference_t<T> *;
487 using const_pointer = const std::remove_reference_t<T> *;
488
489public:
490 /// Create an Expected<T> error value from the given Error.
491 Expected(Error Err)
492 : HasError(true)
493#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
494 // Expected is unchecked upon construction in Debug builds.
495 , Unchecked(true)
496#endif
497 {
498 assert(Err && "Cannot create Expected<T> from Error success value.")(static_cast <bool> (Err && "Cannot create Expected<T> from Error success value."
) ? void (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "llvm/include/llvm/Support/Error.h", 498, __extension__ __PRETTY_FUNCTION__
));
499 new (getErrorStorage()) error_type(Err.takePayload());
500 }
501
502 /// Forbid to convert from Error::success() implicitly, this avoids having
503 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
504 /// but triggers the assertion above.
505 Expected(ErrorSuccess) = delete;
506
507 /// Create an Expected<T> success value from the given OtherT value, which
508 /// must be convertible to T.
509 template <typename OtherT>
510 Expected(OtherT &&Val,
511 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
512 : HasError(false)
513#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
514 // Expected is unchecked upon construction in Debug builds.
515 ,
516 Unchecked(true)
517#endif
518 {
519 new (getStorage()) storage_type(std::forward<OtherT>(Val));
520 }
521
522 /// Move construct an Expected<T> value.
523 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
524
525 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
526 /// must be convertible to T.
527 template <class OtherT>
528 Expected(
529 Expected<OtherT> &&Other,
530 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
531 moveConstruct(std::move(Other));
532 }
533
534 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
535 /// isn't convertible to T.
536 template <class OtherT>
537 explicit Expected(
538 Expected<OtherT> &&Other,
539 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
540 moveConstruct(std::move(Other));
541 }
542
543 /// Move-assign from another Expected<T>.
544 Expected &operator=(Expected &&Other) {
545 moveAssign(std::move(Other));
546 return *this;
547 }
548
549 /// Destroy an Expected<T>.
550 ~Expected() {
551 assertIsChecked();
552 if (!HasError)
553 getStorage()->~storage_type();
554 else
555 getErrorStorage()->~error_type();
556 }
557
558 /// Return false if there is an error.
559 explicit operator bool() {
560#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
561 Unchecked = HasError;
562#endif
563 return !HasError;
564 }
565
566 /// Returns a reference to the stored T value.
567 reference get() {
568 assertIsChecked();
569 return *getStorage();
570 }
571
572 /// Returns a const reference to the stored T value.
573 const_reference get() const {
574 assertIsChecked();
575 return const_cast<Expected<T> *>(this)->get();
576 }
577
578 /// Returns \a takeError() after moving the held T (if any) into \p V.
579 template <class OtherT>
580 Error moveInto(OtherT &Value,
581 std::enable_if_t<std::is_assignable<OtherT &, T &&>::value> * =
582 nullptr) && {
583 if (*this)
584 Value = std::move(get());
585 return takeError();
586 }
587
588 /// Check that this Expected<T> is an error of type ErrT.
589 template <typename ErrT> bool errorIsA() const {
590 return HasError && (*getErrorStorage())->template isA<ErrT>();
591 }
592
593 /// Take ownership of the stored error.
594 /// After calling this the Expected<T> is in an indeterminate state that can
595 /// only be safely destructed. No further calls (beside the destructor) should
596 /// be made on the Expected<T> value.
597 Error takeError() {
598#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
599 Unchecked = false;
600#endif
601 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
602 }
603
604 /// Returns a pointer to the stored T value.
605 pointer operator->() {
606 assertIsChecked();
607 return toPointer(getStorage());
608 }
609
610 /// Returns a const pointer to the stored T value.
611 const_pointer operator->() const {
612 assertIsChecked();
613 return toPointer(getStorage());
614 }
615
616 /// Returns a reference to the stored T value.
617 reference operator*() {
618 assertIsChecked();
619 return *getStorage();
620 }
621
622 /// Returns a const reference to the stored T value.
623 const_reference operator*() const {
624 assertIsChecked();
625 return *getStorage();
626 }
627
628private:
629 template <class T1>
630 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
631 return &a == &b;
632 }
633
634 template <class T1, class T2>
635 static bool compareThisIfSameType(const T1 &, const T2 &) {
636 return false;
637 }
638
639 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
640 HasError = Other.HasError;
641#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
642 Unchecked = true;
643 Other.Unchecked = false;
644#endif
645
646 if (!HasError)
647 new (getStorage()) storage_type(std::move(*Other.getStorage()));
648 else
649 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
650 }
651
652 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
653 assertIsChecked();
654
655 if (compareThisIfSameType(*this, Other))
656 return;
657
658 this->~Expected();
659 new (this) Expected(std::move(Other));
660 }
661
662 pointer toPointer(pointer Val) { return Val; }
663
664 const_pointer toPointer(const_pointer Val) const { return Val; }
665
666 pointer toPointer(wrap *Val) { return &Val->get(); }
667
668 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
669
670 storage_type *getStorage() {
671 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "llvm/include/llvm/Support/Error.h", 671, __extension__ __PRETTY_FUNCTION__
));
672 return reinterpret_cast<storage_type *>(&TStorage);
673 }
674
675 const storage_type *getStorage() const {
676 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "llvm/include/llvm/Support/Error.h", 676, __extension__ __PRETTY_FUNCTION__
));
677 return reinterpret_cast<const storage_type *>(&TStorage);
678 }
679
680 error_type *getErrorStorage() {
681 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "llvm/include/llvm/Support/Error.h", 681, __extension__ __PRETTY_FUNCTION__
));
682 return reinterpret_cast<error_type *>(&ErrorStorage);
683 }
684
685 const error_type *getErrorStorage() const {
686 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "llvm/include/llvm/Support/Error.h", 686, __extension__ __PRETTY_FUNCTION__
));
687 return reinterpret_cast<const error_type *>(&ErrorStorage);
688 }
689
690 // Used by ExpectedAsOutParameter to reset the checked flag.
691 void setUnchecked() {
692#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
693 Unchecked = true;
694#endif
695 }
696
697#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
698 [[noreturn]] LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline)) void fatalUncheckedExpected() const {
699 dbgs() << "Expected<T> must be checked before access or destruction.\n";
700 if (HasError) {
701 dbgs() << "Unchecked Expected<T> contained error:\n";
702 (*getErrorStorage())->log(dbgs());
703 } else
704 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
705 "values in success mode must still be checked prior to being "
706 "destroyed).\n";
707 abort();
708 }
709#endif
710
711 void assertIsChecked() const {
712#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
713 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
714 fatalUncheckedExpected();
715#endif
716 }
717
718 union {
719 AlignedCharArrayUnion<storage_type> TStorage;
720 AlignedCharArrayUnion<error_type> ErrorStorage;
721 };
722 bool HasError : 1;
723#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
724 bool Unchecked : 1;
725#endif
726};
727
728/// Report a serious error, calling any installed error handler. See
729/// ErrorHandling.h.
730[[noreturn]] void report_fatal_error(Error Err, bool gen_crash_diag = true);
731
732/// Report a fatal error if Err is a failure value.
733///
734/// This function can be used to wrap calls to fallible functions ONLY when it
735/// is known that the Error will always be a success value. E.g.
736///
737/// @code{.cpp}
738/// // foo only attempts the fallible operation if DoFallibleOperation is
739/// // true. If DoFallibleOperation is false then foo always returns
740/// // Error::success().
741/// Error foo(bool DoFallibleOperation);
742///
743/// cantFail(foo(false));
744/// @endcode
745inline void cantFail(Error Err, const char *Msg = nullptr) {
746 if (Err) {
747 if (!Msg)
748 Msg = "Failure value returned from cantFail wrapped call";
749#ifndef NDEBUG
750 std::string Str;
751 raw_string_ostream OS(Str);
752 OS << Msg << "\n" << Err;
753 Msg = OS.str().c_str();
754#endif
755 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 755);
756 }
757}
758
759/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
760/// returns the contained value.
761///
762/// This function can be used to wrap calls to fallible functions ONLY when it
763/// is known that the Error will always be a success value. E.g.
764///
765/// @code{.cpp}
766/// // foo only attempts the fallible operation if DoFallibleOperation is
767/// // true. If DoFallibleOperation is false then foo always returns an int.
768/// Expected<int> foo(bool DoFallibleOperation);
769///
770/// int X = cantFail(foo(false));
771/// @endcode
772template <typename T>
773T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
774 if (ValOrErr)
775 return std::move(*ValOrErr);
776 else {
777 if (!Msg)
778 Msg = "Failure value returned from cantFail wrapped call";
779#ifndef NDEBUG
780 std::string Str;
781 raw_string_ostream OS(Str);
782 auto E = ValOrErr.takeError();
783 OS << Msg << "\n" << E;
784 Msg = OS.str().c_str();
785#endif
786 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 786);
787 }
788}
789
790/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
791/// returns the contained reference.
792///
793/// This function can be used to wrap calls to fallible functions ONLY when it
794/// is known that the Error will always be a success value. E.g.
795///
796/// @code{.cpp}
797/// // foo only attempts the fallible operation if DoFallibleOperation is
798/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
799/// Expected<Bar&> foo(bool DoFallibleOperation);
800///
801/// Bar &X = cantFail(foo(false));
802/// @endcode
803template <typename T>
804T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
805 if (ValOrErr)
806 return *ValOrErr;
807 else {
808 if (!Msg)
809 Msg = "Failure value returned from cantFail wrapped call";
810#ifndef NDEBUG
811 std::string Str;
812 raw_string_ostream OS(Str);
813 auto E = ValOrErr.takeError();
814 OS << Msg << "\n" << E;
815 Msg = OS.str().c_str();
816#endif
817 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 817);
818 }
819}
820
821/// Helper for testing applicability of, and applying, handlers for
822/// ErrorInfo types.
823template <typename HandlerT>
824class ErrorHandlerTraits
825 : public ErrorHandlerTraits<decltype(
826 &std::remove_reference<HandlerT>::type::operator())> {};
827
828// Specialization functions of the form 'Error (const ErrT&)'.
829template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
830public:
831 static bool appliesTo(const ErrorInfoBase &E) {
832 return E.template isA<ErrT>();
833 }
834
835 template <typename HandlerT>
836 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
837 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "llvm/include/llvm/Support/Error.h", 837, __extension__ __PRETTY_FUNCTION__
));
838 return H(static_cast<ErrT &>(*E));
839 }
840};
841
842// Specialization functions of the form 'void (const ErrT&)'.
843template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
844public:
845 static bool appliesTo(const ErrorInfoBase &E) {
846 return E.template isA<ErrT>();
847 }
848
849 template <typename HandlerT>
850 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
851 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "llvm/include/llvm/Support/Error.h", 851, __extension__ __PRETTY_FUNCTION__
));
852 H(static_cast<ErrT &>(*E));
853 return Error::success();
854 }
855};
856
857/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
858template <typename ErrT>
859class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
860public:
861 static bool appliesTo(const ErrorInfoBase &E) {
862 return E.template isA<ErrT>();
863 }
864
865 template <typename HandlerT>
866 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
867 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "llvm/include/llvm/Support/Error.h", 867, __extension__ __PRETTY_FUNCTION__
));
868 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
869 return H(std::move(SubE));
870 }
871};
872
873/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
874template <typename ErrT>
875class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
876public:
877 static bool appliesTo(const ErrorInfoBase &E) {
878 return E.template isA<ErrT>();
879 }
880
881 template <typename HandlerT>
882 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
883 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "llvm/include/llvm/Support/Error.h", 883, __extension__ __PRETTY_FUNCTION__
));
884 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
885 H(std::move(SubE));
886 return Error::success();
887 }
888};
889
890// Specialization for member functions of the form 'RetT (const ErrT&)'.
891template <typename C, typename RetT, typename ErrT>
892class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
893 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
894
895// Specialization for member functions of the form 'RetT (const ErrT&) const'.
896template <typename C, typename RetT, typename ErrT>
897class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
898 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
899
900// Specialization for member functions of the form 'RetT (const ErrT&)'.
901template <typename C, typename RetT, typename ErrT>
902class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
903 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
904
905// Specialization for member functions of the form 'RetT (const ErrT&) const'.
906template <typename C, typename RetT, typename ErrT>
907class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
908 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
909
910/// Specialization for member functions of the form
911/// 'RetT (std::unique_ptr<ErrT>)'.
912template <typename C, typename RetT, typename ErrT>
913class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
914 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
915
916/// Specialization for member functions of the form
917/// 'RetT (std::unique_ptr<ErrT>) const'.
918template <typename C, typename RetT, typename ErrT>
919class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
920 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
921
922inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
923 return Error(std::move(Payload));
924}
925
926template <typename HandlerT, typename... HandlerTs>
927Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
928 HandlerT &&Handler, HandlerTs &&... Handlers) {
929 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
930 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
931 std::move(Payload));
932 return handleErrorImpl(std::move(Payload),
933 std::forward<HandlerTs>(Handlers)...);
934}
935
936/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
937/// unhandled errors (or Errors returned by handlers) are re-concatenated and
938/// returned.
939/// Because this function returns an error, its result must also be checked
940/// or returned. If you intend to handle all errors use handleAllErrors
941/// (which returns void, and will abort() on unhandled errors) instead.
942template <typename... HandlerTs>
943Error handleErrors(Error E, HandlerTs &&... Hs) {
944 if (!E)
945 return Error::success();
946
947 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
948
949 if (Payload->isA<ErrorList>()) {
950 ErrorList &List = static_cast<ErrorList &>(*Payload);
951 Error R;
952 for (auto &P : List.Payloads)
953 R = ErrorList::join(
954 std::move(R),
955 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
956 return R;
957 }
958
959 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
960}
961
962/// Behaves the same as handleErrors, except that by contract all errors
963/// *must* be handled by the given handlers (i.e. there must be no remaining
964/// errors after running the handlers, or llvm_unreachable is called).
965template <typename... HandlerTs>
966void handleAllErrors(Error E, HandlerTs &&... Handlers) {
967 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
968}
969
970/// Check that E is a non-error, then drop it.
971/// If E is an error, llvm_unreachable will be called.
972inline void handleAllErrors(Error E) {
973 cantFail(std::move(E));
974}
975
976/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
977///
978/// If the incoming value is a success value it is returned unmodified. If it
979/// is a failure value then it the contained error is passed to handleErrors.
980/// If handleErrors is able to handle the error then the RecoveryPath functor
981/// is called to supply the final result. If handleErrors is not able to
982/// handle all errors then the unhandled errors are returned.
983///
984/// This utility enables the follow pattern:
985///
986/// @code{.cpp}
987/// enum FooStrategy { Aggressive, Conservative };
988/// Expected<Foo> foo(FooStrategy S);
989///
990/// auto ResultOrErr =
991/// handleExpected(
992/// foo(Aggressive),
993/// []() { return foo(Conservative); },
994/// [](AggressiveStrategyError&) {
995/// // Implicitly conusme this - we'll recover by using a conservative
996/// // strategy.
997/// });
998///
999/// @endcode
1000template <typename T, typename RecoveryFtor, typename... HandlerTs>
1001Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
1002 HandlerTs &&... Handlers) {
1003 if (ValOrErr)
1004 return ValOrErr;
1005
1006 if (auto Err = handleErrors(ValOrErr.takeError(),
1007 std::forward<HandlerTs>(Handlers)...))
1008 return std::move(Err);
1009
1010 return RecoveryPath();
1011}
1012
1013/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1014/// will be printed before the first one is logged. A newline will be printed
1015/// after each error.
1016///
1017/// This function is compatible with the helpers from Support/WithColor.h. You
1018/// can pass any of them as the OS. Please consider using them instead of
1019/// including 'error: ' in the ErrorBanner.
1020///
1021/// This is useful in the base level of your program to allow clean termination
1022/// (allowing clean deallocation of resources, etc.), while reporting error
1023/// information to the user.
1024void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1025
1026/// Write all error messages (if any) in E to a string. The newline character
1027/// is used to separate error messages.
1028inline std::string toString(Error E) {
1029 SmallVector<std::string, 2> Errors;
1030 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1031 Errors.push_back(EI.message());
1032 });
1033 return join(Errors.begin(), Errors.end(), "\n");
1034}
1035
1036/// Consume a Error without doing anything. This method should be used
1037/// only where an error can be considered a reasonable and expected return
1038/// value.
1039///
1040/// Uses of this method are potentially indicative of design problems: If it's
1041/// legitimate to do nothing while processing an "error", the error-producer
1042/// might be more clearly refactored to return an Optional<T>.
1043inline void consumeError(Error Err) {
1044 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1045}
1046
1047/// Convert an Expected to an Optional without doing anything. This method
1048/// should be used only where an error can be considered a reasonable and
1049/// expected return value.
1050///
1051/// Uses of this method are potentially indicative of problems: perhaps the
1052/// error should be propagated further, or the error-producer should just
1053/// return an Optional in the first place.
1054template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1055 if (E)
1056 return std::move(*E);
1057 consumeError(E.takeError());
1058 return None;
1059}
1060
1061/// Helper for converting an Error to a bool.
1062///
1063/// This method returns true if Err is in an error state, or false if it is
1064/// in a success state. Puts Err in a checked state in both cases (unlike
1065/// Error::operator bool(), which only does this for success states).
1066inline bool errorToBool(Error Err) {
1067 bool IsError = static_cast<bool>(Err);
1068 if (IsError)
1069 consumeError(std::move(Err));
1070 return IsError;
1071}
1072
1073/// Helper for Errors used as out-parameters.
1074///
1075/// This helper is for use with the Error-as-out-parameter idiom, where an error
1076/// is passed to a function or method by reference, rather than being returned.
1077/// In such cases it is helpful to set the checked bit on entry to the function
1078/// so that the error can be written to (unchecked Errors abort on assignment)
1079/// and clear the checked bit on exit so that clients cannot accidentally forget
1080/// to check the result. This helper performs these actions automatically using
1081/// RAII:
1082///
1083/// @code{.cpp}
1084/// Result foo(Error &Err) {
1085/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1086/// // <body of foo>
1087/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1088/// }
1089/// @endcode
1090///
1091/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1092/// used with optional Errors (Error pointers that are allowed to be null). If
1093/// ErrorAsOutParameter took an Error reference, an instance would have to be
1094/// created inside every condition that verified that Error was non-null. By
1095/// taking an Error pointer we can just create one instance at the top of the
1096/// function.
1097class ErrorAsOutParameter {
1098public:
1099 ErrorAsOutParameter(Error *Err) : Err(Err) {
1100 // Raise the checked bit if Err is success.
1101 if (Err)
1102 (void)!!*Err;
1103 }
1104
1105 ~ErrorAsOutParameter() {
1106 // Clear the checked bit.
1107 if (Err && !*Err)
1108 *Err = Error::success();
1109 }
1110
1111private:
1112 Error *Err;
1113};
1114
1115/// Helper for Expected<T>s used as out-parameters.
1116///
1117/// See ErrorAsOutParameter.
1118template <typename T>
1119class ExpectedAsOutParameter {
1120public:
1121 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1122 : ValOrErr(ValOrErr) {
1123 if (ValOrErr)
1124 (void)!!*ValOrErr;
1125 }
1126
1127 ~ExpectedAsOutParameter() {
1128 if (ValOrErr)
1129 ValOrErr->setUnchecked();
1130 }
1131
1132private:
1133 Expected<T> *ValOrErr;
1134};
1135
1136/// This class wraps a std::error_code in a Error.
1137///
1138/// This is useful if you're writing an interface that returns a Error
1139/// (or Expected) and you want to call code that still returns
1140/// std::error_codes.
1141class ECError : public ErrorInfo<ECError> {
1142 friend Error errorCodeToError(std::error_code);
1143
1144 virtual void anchor() override;
1145
1146public:
1147 void setErrorCode(std::error_code EC) { this->EC = EC; }
1148 std::error_code convertToErrorCode() const override { return EC; }
1149 void log(raw_ostream &OS) const override { OS << EC.message(); }
1150
1151 // Used by ErrorInfo::classID.
1152 static char ID;
1153
1154protected:
1155 ECError() = default;
1156 ECError(std::error_code EC) : EC(EC) {}
1157
1158 std::error_code EC;
1159};
1160
1161/// The value returned by this function can be returned from convertToErrorCode
1162/// for Error values where no sensible translation to std::error_code exists.
1163/// It should only be used in this situation, and should never be used where a
1164/// sensible conversion to std::error_code is available, as attempts to convert
1165/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1166/// error to try to convert such a value).
1167std::error_code inconvertibleErrorCode();
1168
1169/// Helper for converting an std::error_code to a Error.
1170Error errorCodeToError(std::error_code EC);
1171
1172/// Helper for converting an ECError to a std::error_code.
1173///
1174/// This method requires that Err be Error() or an ECError, otherwise it
1175/// will trigger a call to abort().
1176std::error_code errorToErrorCode(Error Err);
1177
1178/// Convert an ErrorOr<T> to an Expected<T>.
1179template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1180 if (auto EC = EO.getError())
1181 return errorCodeToError(EC);
1182 return std::move(*EO);
1183}
1184
1185/// Convert an Expected<T> to an ErrorOr<T>.
1186template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1187 if (auto Err = E.takeError())
1188 return errorToErrorCode(std::move(Err));
1189 return std::move(*E);
1190}
1191
1192/// This class wraps a string in an Error.
1193///
1194/// StringError is useful in cases where the client is not expected to be able
1195/// to consume the specific error message programmatically (for example, if the
1196/// error message is to be presented to the user).
1197///
1198/// StringError can also be used when additional information is to be printed
1199/// along with a error_code message. Depending on the constructor called, this
1200/// class can either display:
1201/// 1. the error_code message (ECError behavior)
1202/// 2. a string
1203/// 3. the error_code message and a string
1204///
1205/// These behaviors are useful when subtyping is required; for example, when a
1206/// specific library needs an explicit error type. In the example below,
1207/// PDBError is derived from StringError:
1208///
1209/// @code{.cpp}
1210/// Expected<int> foo() {
1211/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1212/// "Additional information");
1213/// }
1214/// @endcode
1215///
1216class StringError : public ErrorInfo<StringError> {
1217public:
1218 static char ID;
1219
1220 // Prints EC + S and converts to EC
1221 StringError(std::error_code EC, const Twine &S = Twine());
1222
1223 // Prints S and converts to EC
1224 StringError(const Twine &S, std::error_code EC);
1225
1226 void log(raw_ostream &OS) const override;
1227 std::error_code convertToErrorCode() const override;
1228
1229 const std::string &getMessage() const { return Msg; }
1230
1231private:
1232 std::string Msg;
1233 std::error_code EC;
1234 const bool PrintMsgOnly = false;
1235};
1236
1237/// Create formatted StringError object.
1238template <typename... Ts>
1239inline Error createStringError(std::error_code EC, char const *Fmt,
1240 const Ts &... Vals) {
1241 std::string Buffer;
1242 raw_string_ostream Stream(Buffer);
1243 Stream << format(Fmt, Vals...);
1244 return make_error<StringError>(Stream.str(), EC);
1245}
1246
1247Error createStringError(std::error_code EC, char const *Msg);
1248
1249inline Error createStringError(std::error_code EC, const Twine &S) {
1250 return createStringError(EC, S.str().c_str());
1251}
1252
1253template <typename... Ts>
1254inline Error createStringError(std::errc EC, char const *Fmt,
1255 const Ts &... Vals) {
1256 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1257}
1258
1259/// This class wraps a filename and another Error.
1260///
1261/// In some cases, an error needs to live along a 'source' name, in order to
1262/// show more detailed information to the user.
1263class FileError final : public ErrorInfo<FileError> {
1264
1265 friend Error createFileError(const Twine &, Error);
1266 friend Error createFileError(const Twine &, size_t, Error);
1267
1268public:
1269 void log(raw_ostream &OS) const override {
1270 assert(Err && "Trying to log after takeError().")(static_cast <bool> (Err && "Trying to log after takeError()."
) ? void (0) : __assert_fail ("Err && \"Trying to log after takeError().\""
, "llvm/include/llvm/Support/Error.h", 1270, __extension__ __PRETTY_FUNCTION__
));
1271 OS << "'" << FileName << "': ";
1272 if (Line.hasValue())
1273 OS << "line " << Line.getValue() << ": ";
1274 Err->log(OS);
1275 }
1276
1277 std::string messageWithoutFileInfo() const {
1278 std::string Msg;
1279 raw_string_ostream OS(Msg);
1280 Err->log(OS);
1281 return OS.str();
1282 }
1283
1284 StringRef getFileName() const { return FileName; }
1285
1286 Error takeError() { return Error(std::move(Err)); }
1287
1288 std::error_code convertToErrorCode() const override;
1289
1290 // Used by ErrorInfo::classID.
1291 static char ID;
1292
1293private:
1294 FileError(const Twine &F, Optional<size_t> LineNum,
1295 std::unique_ptr<ErrorInfoBase> E) {
1296 assert(E && "Cannot create FileError from Error success value.")(static_cast <bool> (E && "Cannot create FileError from Error success value."
) ? void (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "llvm/include/llvm/Support/Error.h", 1296, __extension__ __PRETTY_FUNCTION__
));
1297 FileName = F.str();
1298 Err = std::move(E);
1299 Line = std::move(LineNum);
1300 }
1301
1302 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1303 std::unique_ptr<ErrorInfoBase> Payload;
1304 handleAllErrors(std::move(E),
1305 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1306 Payload = std::move(EIB);
1307 return Error::success();
1308 });
1309 return Error(
1310 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1311 }
1312
1313 std::string FileName;
1314 Optional<size_t> Line;
1315 std::unique_ptr<ErrorInfoBase> Err;
1316};
1317
1318/// Concatenate a source file path and/or name with an Error. The resulting
1319/// Error is unchecked.
1320inline Error createFileError(const Twine &F, Error E) {
1321 return FileError::build(F, Optional<size_t>(), std::move(E));
1322}
1323
1324/// Concatenate a source file path and/or name with line number and an Error.
1325/// The resulting Error is unchecked.
1326inline Error createFileError(const Twine &F, size_t Line, Error E) {
1327 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1328}
1329
1330/// Concatenate a source file path and/or name with a std::error_code
1331/// to form an Error object.
1332inline Error createFileError(const Twine &F, std::error_code EC) {
1333 return createFileError(F, errorCodeToError(EC));
1334}
1335
1336/// Concatenate a source file path and/or name with line number and
1337/// std::error_code to form an Error object.
1338inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1339 return createFileError(F, Line, errorCodeToError(EC));
1340}
1341
1342Error createFileError(const Twine &F, ErrorSuccess) = delete;
1343
1344/// Helper for check-and-exit error handling.
1345///
1346/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1347///
1348class ExitOnError {
1349public:
1350 /// Create an error on exit helper.
1351 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1352 : Banner(std::move(Banner)),
1353 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1354
1355 /// Set the banner string for any errors caught by operator().
1356 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1357
1358 /// Set the exit-code mapper function.
1359 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1360 this->GetExitCode = std::move(GetExitCode);
1361 }
1362
1363 /// Check Err. If it's in a failure state log the error(s) and exit.
1364 void operator()(Error Err) const { checkError(std::move(Err)); }
1365
1366 /// Check E. If it's in a success state then return the contained value. If
1367 /// it's in a failure state log the error(s) and exit.
1368 template <typename T> T operator()(Expected<T> &&E) const {
1369 checkError(E.takeError());
1370 return std::move(*E);
1371 }
1372
1373 /// Check E. If it's in a success state then return the contained reference. If
1374 /// it's in a failure state log the error(s) and exit.
1375 template <typename T> T& operator()(Expected<T&> &&E) const {
1376 checkError(E.takeError());
1377 return *E;
1378 }
1379
1380private:
1381 void checkError(Error Err) const {
1382 if (Err) {
1383 int ExitCode = GetExitCode(Err);
1384 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1385 exit(ExitCode);
1386 }
1387 }
1388
1389 std::string Banner;
1390 std::function<int(const Error &)> GetExitCode;
1391};
1392
1393/// Conversion from Error to LLVMErrorRef for C error bindings.
1394inline LLVMErrorRef wrap(Error Err) {
1395 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1396}
1397
1398/// Conversion from LLVMErrorRef to Error for C error bindings.
1399inline Error unwrap(LLVMErrorRef ErrRef) {
1400 return Error(std::unique_ptr<ErrorInfoBase>(
1401 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1402}
1403
1404} // end namespace llvm
1405
1406#endif // LLVM_SUPPORT_ERROR_H