Bug Summary

File:llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
Warning:line 190, column 29
Moved-from object 'Err' is moved

Annotated Source Code

Press '?' to see keyboard shortcuts

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-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -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-14~++20220119111520+da61cb019eb2/llvm/tools/dsymutil -I include -I /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/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-14/lib/clang/14.0.0/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-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -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-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -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-2022-01-19-134126-35450-1 -x c++ /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/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/CodeGen/AccelTable.h"
34#include "llvm/CodeGen/AsmPrinter.h"
35#include "llvm/CodeGen/DIE.h"
36#include "llvm/CodeGen/NonRelocatableStringpool.h"
37#include "llvm/Config/config.h"
38#include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
39#include "llvm/DebugInfo/DIContext.h"
40#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
41#include "llvm/DebugInfo/DWARF/DWARFContext.h"
42#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
43#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
44#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
45#include "llvm/DebugInfo/DWARF/DWARFDie.h"
46#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
47#include "llvm/DebugInfo/DWARF/DWARFSection.h"
48#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
49#include "llvm/MC/MCAsmBackend.h"
50#include "llvm/MC/MCAsmInfo.h"
51#include "llvm/MC/MCCodeEmitter.h"
52#include "llvm/MC/MCContext.h"
53#include "llvm/MC/MCDwarf.h"
54#include "llvm/MC/MCInstrInfo.h"
55#include "llvm/MC/MCObjectFileInfo.h"
56#include "llvm/MC/MCObjectWriter.h"
57#include "llvm/MC/MCRegisterInfo.h"
58#include "llvm/MC/MCSection.h"
59#include "llvm/MC/MCStreamer.h"
60#include "llvm/MC/MCSubtargetInfo.h"
61#include "llvm/MC/MCTargetOptions.h"
62#include "llvm/MC/MCTargetOptionsCommandFlags.h"
63#include "llvm/MC/TargetRegistry.h"
64#include "llvm/Object/MachO.h"
65#include "llvm/Object/ObjectFile.h"
66#include "llvm/Object/SymbolicFile.h"
67#include "llvm/Support/Allocator.h"
68#include "llvm/Support/Casting.h"
69#include "llvm/Support/Compiler.h"
70#include "llvm/Support/DJB.h"
71#include "llvm/Support/DataExtractor.h"
72#include "llvm/Support/Error.h"
73#include "llvm/Support/ErrorHandling.h"
74#include "llvm/Support/ErrorOr.h"
75#include "llvm/Support/FileSystem.h"
76#include "llvm/Support/Format.h"
77#include "llvm/Support/LEB128.h"
78#include "llvm/Support/MathExtras.h"
79#include "llvm/Support/MemoryBuffer.h"
80#include "llvm/Support/Path.h"
81#include "llvm/Support/ThreadPool.h"
82#include "llvm/Support/ToolOutputFile.h"
83#include "llvm/Support/WithColor.h"
84#include "llvm/Support/raw_ostream.h"
85#include "llvm/Target/TargetMachine.h"
86#include "llvm/Target/TargetOptions.h"
87#include <algorithm>
88#include <cassert>
89#include <cinttypes>
90#include <climits>
91#include <cstdint>
92#include <cstdlib>
93#include <cstring>
94#include <limits>
95#include <map>
96#include <memory>
97#include <string>
98#include <system_error>
99#include <tuple>
100#include <utility>
101#include <vector>
102
103namespace llvm {
104
105static mc::RegisterMCTargetOptionsFlags MOF;
106
107namespace dsymutil {
108
109static Error copySwiftInterfaces(
110 const std::map<std::string, std::string> &ParseableSwiftInterfaces,
111 StringRef Architecture, const LinkOptions &Options) {
112 std::error_code EC;
113 SmallString<128> InputPath;
114 SmallString<128> Path;
115 sys::path::append(Path, *Options.ResourceDir, "Swift", Architecture);
116 if ((EC = sys::fs::create_directories(Path.str(), true,
117 sys::fs::perms::all_all)))
118 return make_error<StringError>(
119 "cannot create directory: " + toString(errorCodeToError(EC)), EC);
120 unsigned BaseLength = Path.size();
121
122 for (auto &I : ParseableSwiftInterfaces) {
123 StringRef ModuleName = I.first;
124 StringRef InterfaceFile = I.second;
125 if (!Options.PrependPath.empty()) {
126 InputPath.clear();
127 sys::path::append(InputPath, Options.PrependPath, InterfaceFile);
128 InterfaceFile = InputPath;
129 }
130 sys::path::append(Path, ModuleName);
131 Path.append(".swiftinterface");
132 if (Options.Verbose)
133 outs() << "copy parseable Swift interface " << InterfaceFile << " -> "
134 << Path.str() << '\n';
135
136 // copy_file attempts an APFS clone first, so this should be cheap.
137 if ((EC = sys::fs::copy_file(InterfaceFile, Path.str())))
138 warn(Twine("cannot copy parseable Swift interface ") + InterfaceFile +
139 ": " + toString(errorCodeToError(EC)));
140 Path.resize(BaseLength);
141 }
142 return Error::success();
143}
144
145/// Report a warning to the user, optionally including information about a
146/// specific \p DIE related to the warning.
147void DwarfLinkerForBinary::reportWarning(const Twine &Warning,
148 StringRef Context,
149 const DWARFDie *DIE) const {
150
151 warn(Warning, Context);
152
153 if (!Options.Verbose || !DIE)
154 return;
155
156 DIDumpOptions DumpOpts;
157 DumpOpts.ChildRecurseDepth = 0;
158 DumpOpts.Verbose = Options.Verbose;
159
160 WithColor::note() << " in DIE:\n";
161 DIE->dump(errs(), 6 /* Indent */, DumpOpts);
162}
163
164bool DwarfLinkerForBinary::createStreamer(const Triple &TheTriple,
165 raw_fd_ostream &OutFile) {
166 if (Options.NoOutput)
167 return true;
168
169 Streamer = std::make_unique<DwarfStreamer>(
170 Options.FileType, OutFile, Options.Translator,
171 [&](const Twine &Error, StringRef Context, const DWARFDie *) {
172 error(Error, Context);
173 },
174 [&](const Twine &Warning, StringRef Context, const DWARFDie *) {
175 warn(Warning, Context);
176 });
177 return Streamer->init(TheTriple);
178}
179
180ErrorOr<const object::ObjectFile &>
181DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
182 const Triple &Triple) {
183 auto ObjectEntry =
184 BinHolder.getObjectEntry(Obj.getObjectFilename(), Obj.getTimestamp());
185 if (!ObjectEntry) {
3
Taking true branch
186 auto Err = ObjectEntry.takeError();
187 reportWarning(Twine(Obj.getObjectFilename()) + ": " +
188 toString(std::move(Err)),
4
Calling move constructor for 'Error'
6
Returning from move constructor for 'Error'
189 Obj.getObjectFilename());
190 return errorToErrorCode(std::move(Err));
7
Moved-from object 'Err' is moved
191 }
192
193 auto Object = ObjectEntry->getObject(Triple);
194 if (!Object) {
195 auto Err = Object.takeError();
196 reportWarning(Twine(Obj.getObjectFilename()) + ": " +
197 toString(std::move(Err)),
198 Obj.getObjectFilename());
199 return errorToErrorCode(std::move(Err));
200 }
201
202 return *Object;
203}
204
205static Error remarksErrorHandler(const DebugMapObject &DMO,
206 DwarfLinkerForBinary &Linker,
207 std::unique_ptr<FileError> FE) {
208 bool IsArchive = DMO.getObjectFilename().endswith(")");
209 // Don't report errors for missing remark files from static
210 // archives.
211 if (!IsArchive)
212 return Error(std::move(FE));
213
214 std::string Message = FE->message();
215 Error E = FE->takeError();
216 Error NewE = handleErrors(std::move(E), [&](std::unique_ptr<ECError> EC) {
217 if (EC->convertToErrorCode() != std::errc::no_such_file_or_directory)
218 return Error(std::move(EC));
219
220 Linker.reportWarning(Message, DMO.getObjectFilename());
221 return Error(Error::success());
222 });
223
224 if (!NewE)
225 return Error::success();
226
227 return createFileError(FE->getFileName(), std::move(NewE));
228}
229
230static Error emitRemarks(const LinkOptions &Options, StringRef BinaryPath,
231 StringRef ArchName, const remarks::RemarkLinker &RL) {
232 // Make sure we don't create the directories and the file if there is nothing
233 // to serialize.
234 if (RL.empty())
235 return Error::success();
236
237 SmallString<128> InputPath;
238 SmallString<128> Path;
239 // Create the "Remarks" directory in the "Resources" directory.
240 sys::path::append(Path, *Options.ResourceDir, "Remarks");
241 if (std::error_code EC = sys::fs::create_directories(Path.str(), true,
242 sys::fs::perms::all_all))
243 return errorCodeToError(EC);
244
245 // Append the file name.
246 // For fat binaries, also append a dash and the architecture name.
247 sys::path::append(Path, sys::path::filename(BinaryPath));
248 if (Options.NumDebugMaps > 1) {
249 // More than one debug map means we have a fat binary.
250 Path += '-';
251 Path += ArchName;
252 }
253
254 std::error_code EC;
255 raw_fd_ostream OS(Options.NoOutput ? "-" : Path.str(), EC,
256 Options.RemarksFormat == remarks::Format::Bitstream
257 ? sys::fs::OF_None
258 : sys::fs::OF_Text);
259 if (EC)
260 return errorCodeToError(EC);
261
262 if (Error E = RL.serialize(OS, Options.RemarksFormat))
263 return E;
264
265 return Error::success();
266}
267
268ErrorOr<DWARFFile &>
269DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
270 const DebugMap &DebugMap,
271 remarks::RemarkLinker &RL) {
272 auto ErrorOrObj = loadObject(Obj, DebugMap.getTriple());
2
Calling 'DwarfLinkerForBinary::loadObject'
273
274 if (ErrorOrObj) {
275 ContextForLinking.push_back(
276 std::unique_ptr<DWARFContext>(DWARFContext::create(*ErrorOrObj)));
277 AddressMapForLinking.push_back(
278 std::make_unique<AddressManager>(*this, *ErrorOrObj, Obj));
279
280 ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
281 Obj.getObjectFilename(), ContextForLinking.back().get(),
282 AddressMapForLinking.back().get(),
283 Obj.empty() ? Obj.getWarnings() : EmptyWarnings));
284
285 Error E = RL.link(*ErrorOrObj);
286 if (Error NewE = handleErrors(
287 std::move(E), [&](std::unique_ptr<FileError> EC) -> Error {
288 return remarksErrorHandler(Obj, *this, std::move(EC));
289 }))
290 return errorToErrorCode(std::move(NewE));
291
292 return *ObjectsForLinking.back();
293 }
294
295 return ErrorOrObj.getError();
296}
297
298bool DwarfLinkerForBinary::link(const DebugMap &Map) {
299 if (!createStreamer(Map.getTriple(), OutFile))
300 return false;
301
302 ObjectsForLinking.clear();
303 ContextForLinking.clear();
304 AddressMapForLinking.clear();
305
306 DebugMap DebugMap(Map.getTriple(), Map.getBinaryPath());
307
308 DWARFLinker GeneralLinker(Streamer.get(), DwarfLinkerClient::Dsymutil);
309
310 remarks::RemarkLinker RL;
311 if (!Options.RemarksPrependPath.empty())
312 RL.setExternalFilePrependPath(Options.RemarksPrependPath);
313 GeneralLinker.setObjectPrefixMap(&Options.ObjectPrefixMap);
314
315 std::function<StringRef(StringRef)> TranslationLambda = [&](StringRef Input) {
316 assert(Options.Translator)(static_cast <bool> (Options.Translator) ? void (0) : __assert_fail
("Options.Translator", "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp"
, 316, __extension__ __PRETTY_FUNCTION__))
;
317 return Options.Translator(Input);
318 };
319
320 GeneralLinker.setVerbosity(Options.Verbose);
321 GeneralLinker.setStatistics(Options.Statistics);
322 GeneralLinker.setNoOutput(Options.NoOutput);
323 GeneralLinker.setNoODR(Options.NoODR);
324 GeneralLinker.setUpdate(Options.Update);
325 GeneralLinker.setNumThreads(Options.Threads);
326 GeneralLinker.setAccelTableKind(Options.TheAccelTableKind);
327 GeneralLinker.setPrependPath(Options.PrependPath);
328 GeneralLinker.setKeepFunctionForStatic(Options.KeepFunctionForStatic);
329 if (Options.Translator)
330 GeneralLinker.setStringsTranslator(TranslationLambda);
331 GeneralLinker.setWarningHandler(
332 [&](const Twine &Warning, StringRef Context, const DWARFDie *DIE) {
333 reportWarning(Warning, Context, DIE);
334 });
335 GeneralLinker.setErrorHandler(
336 [&](const Twine &Error, StringRef Context, const DWARFDie *) {
337 error(Error, Context);
338 });
339 GeneralLinker.setObjFileLoader(
340 [&DebugMap, &RL, this](StringRef ContainerName,
341 StringRef Path) -> ErrorOr<DWARFFile &> {
342 auto &Obj = DebugMap.addDebugMapObject(
343 Path, sys::TimePoint<std::chrono::seconds>(), MachO::N_OSO);
344
345 if (auto ErrorOrObj = loadObject(Obj, DebugMap, RL)) {
1
Calling 'DwarfLinkerForBinary::loadObject'
346 return *ErrorOrObj;
347 } else {
348 // Try and emit more helpful warnings by applying some heuristics.
349 StringRef ObjFile = ContainerName;
350 bool IsClangModule = sys::path::extension(Path).equals(".pcm");
351 bool IsArchive = ObjFile.endswith(")");
352
353 if (IsClangModule) {
354 StringRef ModuleCacheDir = sys::path::parent_path(Path);
355 if (sys::fs::exists(ModuleCacheDir)) {
356 // If the module's parent directory exists, we assume that the
357 // module cache has expired and was pruned by clang. A more
358 // adventurous dsymutil would invoke clang to rebuild the module
359 // now.
360 if (!ModuleCacheHintDisplayed) {
361 WithColor::note()
362 << "The clang module cache may have expired since "
363 "this object file was built. Rebuilding the "
364 "object file will rebuild the module cache.\n";
365 ModuleCacheHintDisplayed = true;
366 }
367 } else if (IsArchive) {
368 // If the module cache directory doesn't exist at all and the
369 // object file is inside a static library, we assume that the
370 // static library was built on a different machine. We don't want
371 // to discourage module debugging for convenience libraries within
372 // a project though.
373 if (!ArchiveHintDisplayed) {
374 WithColor::note()
375 << "Linking a static library that was built with "
376 "-gmodules, but the module cache was not found. "
377 "Redistributable static libraries should never be "
378 "built with module debugging enabled. The debug "
379 "experience will be degraded due to incomplete "
380 "debug information.\n";
381 ArchiveHintDisplayed = true;
382 }
383 }
384 }
385
386 return ErrorOrObj.getError();
387 }
388
389 llvm_unreachable("Unhandled DebugMap object")::llvm::llvm_unreachable_internal("Unhandled DebugMap object"
, "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp", 389)
;
390 });
391 GeneralLinker.setSwiftInterfacesMap(&ParseableSwiftInterfaces);
392
393 for (const auto &Obj : Map.objects()) {
394 // N_AST objects (swiftmodule files) should get dumped directly into the
395 // appropriate DWARF section.
396 if (Obj->getType() == MachO::N_AST) {
397 if (Options.Verbose)
398 outs() << "DEBUG MAP OBJECT: " << Obj->getObjectFilename() << "\n";
399
400 StringRef File = Obj->getObjectFilename();
401 auto ErrorOrMem = MemoryBuffer::getFile(File);
402 if (!ErrorOrMem) {
403 warn("Could not open '" + File + "'\n");
404 continue;
405 }
406 sys::fs::file_status Stat;
407 if (auto Err = sys::fs::status(File, Stat)) {
408 warn(Err.message());
409 continue;
410 }
411 if (!Options.NoTimestamp) {
412 // The modification can have sub-second precision so we need to cast
413 // away the extra precision that's not present in the debug map.
414 auto ModificationTime =
415 std::chrono::time_point_cast<std::chrono::seconds>(
416 Stat.getLastModificationTime());
417 if (ModificationTime != Obj->getTimestamp()) {
418 // Not using the helper here as we can easily stream TimePoint<>.
419 WithColor::warning()
420 << File << ": timestamp mismatch between swift interface file ("
421 << sys::TimePoint<>(Obj->getTimestamp()) << ") and debug map ("
422 << sys::TimePoint<>(Obj->getTimestamp()) << ")\n";
423 continue;
424 }
425 }
426
427 // Copy the module into the .swift_ast section.
428 if (!Options.NoOutput)
429 Streamer->emitSwiftAST((*ErrorOrMem)->getBuffer());
430
431 continue;
432 }
433
434 if (auto ErrorOrObj = loadObject(*Obj, Map, RL))
435 GeneralLinker.addObjectFile(*ErrorOrObj);
436 else {
437 ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
438 Obj->getObjectFilename(), nullptr, nullptr,
439 Obj->empty() ? Obj->getWarnings() : EmptyWarnings));
440 GeneralLinker.addObjectFile(*ObjectsForLinking.back());
441 }
442 }
443
444 // link debug info for loaded object files.
445 GeneralLinker.link();
446
447 StringRef ArchName = Map.getTriple().getArchName();
448 if (Error E = emitRemarks(Options, Map.getBinaryPath(), ArchName, RL))
449 return error(toString(std::move(E)));
450
451 if (Options.NoOutput)
452 return true;
453
454 if (Options.ResourceDir && !ParseableSwiftInterfaces.empty()) {
455 StringRef ArchName = Triple::getArchTypeName(Map.getTriple().getArch());
456 if (auto E =
457 copySwiftInterfaces(ParseableSwiftInterfaces, ArchName, Options))
458 return error(toString(std::move(E)));
459 }
460
461 if (Map.getTriple().isOSDarwin() && !Map.getBinaryPath().empty() &&
462 Options.FileType == OutputFileType::Object)
463 return MachOUtils::generateDsymCompanion(
464 Options.VFS, Map, Options.Translator,
465 *Streamer->getAsmPrinter().OutStreamer, OutFile);
466
467 Streamer->finish();
468 return true;
469}
470
471static bool isMachOPairedReloc(uint64_t RelocType, uint64_t Arch) {
472 switch (Arch) {
473 case Triple::x86:
474 return RelocType == MachO::GENERIC_RELOC_SECTDIFF ||
475 RelocType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF;
476 case Triple::x86_64:
477 return RelocType == MachO::X86_64_RELOC_SUBTRACTOR;
478 case Triple::arm:
479 case Triple::thumb:
480 return RelocType == MachO::ARM_RELOC_SECTDIFF ||
481 RelocType == MachO::ARM_RELOC_LOCAL_SECTDIFF ||
482 RelocType == MachO::ARM_RELOC_HALF ||
483 RelocType == MachO::ARM_RELOC_HALF_SECTDIFF;
484 case Triple::aarch64:
485 return RelocType == MachO::ARM64_RELOC_SUBTRACTOR;
486 default:
487 return false;
488 }
489}
490
491/// Iterate over the relocations of the given \p Section and
492/// store the ones that correspond to debug map entries into the
493/// ValidRelocs array.
494void DwarfLinkerForBinary::AddressManager::findValidRelocsMachO(
495 const object::SectionRef &Section, const object::MachOObjectFile &Obj,
496 const DebugMapObject &DMO, std::vector<ValidReloc> &ValidRelocs) {
497 Expected<StringRef> ContentsOrErr = Section.getContents();
498 if (!ContentsOrErr) {
499 consumeError(ContentsOrErr.takeError());
500 Linker.reportWarning("error reading section", DMO.getObjectFilename());
501 return;
502 }
503 DataExtractor Data(*ContentsOrErr, Obj.isLittleEndian(), 0);
504 bool SkipNext = false;
505
506 for (const object::RelocationRef &Reloc : Section.relocations()) {
507 if (SkipNext) {
508 SkipNext = false;
509 continue;
510 }
511
512 object::DataRefImpl RelocDataRef = Reloc.getRawDataRefImpl();
513 MachO::any_relocation_info MachOReloc = Obj.getRelocation(RelocDataRef);
514
515 if (isMachOPairedReloc(Obj.getAnyRelocationType(MachOReloc),
516 Obj.getArch())) {
517 SkipNext = true;
518 Linker.reportWarning("unsupported relocation in " + *Section.getName() +
519 " section.",
520 DMO.getObjectFilename());
521 continue;
522 }
523
524 unsigned RelocSize = 1 << Obj.getAnyRelocationLength(MachOReloc);
525 uint64_t Offset64 = Reloc.getOffset();
526 if ((RelocSize != 4 && RelocSize != 8)) {
527 Linker.reportWarning("unsupported relocation in " + *Section.getName() +
528 " section.",
529 DMO.getObjectFilename());
530 continue;
531 }
532 uint64_t OffsetCopy = Offset64;
533 // Mach-o uses REL relocations, the addend is at the relocation offset.
534 uint64_t Addend = Data.getUnsigned(&OffsetCopy, RelocSize);
535 uint64_t SymAddress;
536 int64_t SymOffset;
537
538 if (Obj.isRelocationScattered(MachOReloc)) {
539 // The address of the base symbol for scattered relocations is
540 // stored in the reloc itself. The actual addend will store the
541 // base address plus the offset.
542 SymAddress = Obj.getScatteredRelocationValue(MachOReloc);
543 SymOffset = int64_t(Addend) - SymAddress;
544 } else {
545 SymAddress = Addend;
546 SymOffset = 0;
547 }
548
549 auto Sym = Reloc.getSymbol();
550 if (Sym != Obj.symbol_end()) {
551 Expected<StringRef> SymbolName = Sym->getName();
552 if (!SymbolName) {
553 consumeError(SymbolName.takeError());
554 Linker.reportWarning("error getting relocation symbol name.",
555 DMO.getObjectFilename());
556 continue;
557 }
558 if (const auto *Mapping = DMO.lookupSymbol(*SymbolName))
559 ValidRelocs.emplace_back(Offset64, RelocSize, Addend, Mapping);
560 } else if (const auto *Mapping = DMO.lookupObjectAddress(SymAddress)) {
561 // Do not store the addend. The addend was the address of the symbol in
562 // the object file, the address in the binary that is stored in the debug
563 // map doesn't need to be offset.
564 ValidRelocs.emplace_back(Offset64, RelocSize, SymOffset, Mapping);
565 }
566 }
567}
568
569/// Dispatch the valid relocation finding logic to the
570/// appropriate handler depending on the object file format.
571bool DwarfLinkerForBinary::AddressManager::findValidRelocs(
572 const object::SectionRef &Section, const object::ObjectFile &Obj,
573 const DebugMapObject &DMO, std::vector<ValidReloc> &Relocs) {
574 // Dispatch to the right handler depending on the file type.
575 if (auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Obj))
576 findValidRelocsMachO(Section, *MachOObj, DMO, Relocs);
577 else
578 Linker.reportWarning(Twine("unsupported object file type: ") +
579 Obj.getFileName(),
580 DMO.getObjectFilename());
581 if (Relocs.empty())
582 return false;
583
584 // Sort the relocations by offset. We will walk the DIEs linearly in
585 // the file, this allows us to just keep an index in the relocation
586 // array that we advance during our walk, rather than resorting to
587 // some associative container. See DwarfLinkerForBinary::NextValidReloc.
588 llvm::sort(Relocs);
589 return true;
590}
591
592/// Look for relocations in the debug_info and debug_addr section that match
593/// entries in the debug map. These relocations will drive the Dwarf link by
594/// indicating which DIEs refer to symbols present in the linked binary.
595/// \returns whether there are any valid relocations in the debug info.
596bool DwarfLinkerForBinary::AddressManager::findValidRelocsInDebugSections(
597 const object::ObjectFile &Obj, const DebugMapObject &DMO) {
598 // Find the debug_info section.
599 bool FoundValidRelocs = false;
600 for (const object::SectionRef &Section : Obj.sections()) {
601 StringRef SectionName;
602 if (Expected<StringRef> NameOrErr = Section.getName())
603 SectionName = *NameOrErr;
604 else
605 consumeError(NameOrErr.takeError());
606
607 SectionName = SectionName.substr(SectionName.find_first_not_of("._"));
608 if (SectionName == "debug_info")
609 FoundValidRelocs |=
610 findValidRelocs(Section, Obj, DMO, ValidDebugInfoRelocs);
611 if (SectionName == "debug_addr")
612 FoundValidRelocs |=
613 findValidRelocs(Section, Obj, DMO, ValidDebugAddrRelocs);
614 }
615 return FoundValidRelocs;
616}
617
618std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc>
619DwarfLinkerForBinary::AddressManager::getRelocations(
620 const std::vector<ValidReloc> &Relocs, uint64_t StartPos, uint64_t EndPos) {
621 std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc> Res;
622
623 auto CurReloc = partition_point(Relocs, [StartPos](const ValidReloc &Reloc) {
624 return Reloc.Offset < StartPos;
625 });
626
627 while (CurReloc != Relocs.end() && CurReloc->Offset >= StartPos &&
628 CurReloc->Offset < EndPos) {
629 Res.push_back(*CurReloc);
630 CurReloc++;
631 }
632
633 return Res;
634}
635
636void DwarfLinkerForBinary::AddressManager::printReloc(const ValidReloc &Reloc) {
637 const auto &Mapping = Reloc.Mapping->getValue();
638 const uint64_t ObjectAddress = Mapping.ObjectAddress
639 ? uint64_t(*Mapping.ObjectAddress)
640 : std::numeric_limits<uint64_t>::max();
641
642 outs() << "Found valid debug map entry: " << Reloc.Mapping->getKey() << "\t"
643 << format("0x%016" PRIx64"l" "x" " => 0x%016" PRIx64"l" "x" "\n", ObjectAddress,
644 uint64_t(Mapping.BinaryAddress));
645}
646
647void DwarfLinkerForBinary::AddressManager::fillDieInfo(
648 const ValidReloc &Reloc, CompileUnit::DIEInfo &Info) {
649 Info.AddrAdjust = relocate(Reloc);
650 if (Reloc.Mapping->getValue().ObjectAddress)
651 Info.AddrAdjust -= uint64_t(*Reloc.Mapping->getValue().ObjectAddress);
652 Info.InDebugMap = true;
653}
654
655bool DwarfLinkerForBinary::AddressManager::hasValidRelocationAt(
656 const std::vector<ValidReloc> &AllRelocs, uint64_t StartOffset,
657 uint64_t EndOffset, CompileUnit::DIEInfo &Info) {
658 std::vector<ValidReloc> Relocs =
659 getRelocations(AllRelocs, StartOffset, EndOffset);
660
661 if (Relocs.size() == 0)
662 return false;
663
664 if (Linker.Options.Verbose)
665 printReloc(Relocs[0]);
666 fillDieInfo(Relocs[0], Info);
667
668 return true;
669}
670
671/// Get the starting and ending (exclusive) offset for the
672/// attribute with index \p Idx descibed by \p Abbrev. \p Offset is
673/// supposed to point to the position of the first attribute described
674/// by \p Abbrev.
675/// \return [StartOffset, EndOffset) as a pair.
676static std::pair<uint64_t, uint64_t>
677getAttributeOffsets(const DWARFAbbreviationDeclaration *Abbrev, unsigned Idx,
678 uint64_t Offset, const DWARFUnit &Unit) {
679 DataExtractor Data = Unit.getDebugInfoExtractor();
680
681 for (unsigned I = 0; I < Idx; ++I)
682 DWARFFormValue::skipValue(Abbrev->getFormByIndex(I), Data, &Offset,
683 Unit.getFormParams());
684
685 uint64_t End = Offset;
686 DWARFFormValue::skipValue(Abbrev->getFormByIndex(Idx), Data, &End,
687 Unit.getFormParams());
688
689 return std::make_pair(Offset, End);
690}
691
692bool DwarfLinkerForBinary::AddressManager::hasLiveMemoryLocation(
693 const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
694 const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
695
696 Optional<uint32_t> LocationIdx =
697 Abbrev->findAttributeIndex(dwarf::DW_AT_location);
698 if (!LocationIdx)
699 return false;
700
701 uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
702 uint64_t LocationOffset, LocationEndOffset;
703 std::tie(LocationOffset, LocationEndOffset) =
704 getAttributeOffsets(Abbrev, *LocationIdx, Offset, *DIE.getDwarfUnit());
705
706 // FIXME: Support relocations debug_addr.
707 return hasValidRelocationAt(ValidDebugInfoRelocs, LocationOffset,
708 LocationEndOffset, MyInfo);
709}
710
711bool DwarfLinkerForBinary::AddressManager::hasLiveAddressRange(
712 const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
713 const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
714
715 Optional<uint32_t> LowPcIdx = Abbrev->findAttributeIndex(dwarf::DW_AT_low_pc);
716 if (!LowPcIdx)
717 return false;
718
719 dwarf::Form Form = Abbrev->getFormByIndex(*LowPcIdx);
720
721 if (Form == dwarf::DW_FORM_addr) {
722 uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
723 uint64_t LowPcOffset, LowPcEndOffset;
724 std::tie(LowPcOffset, LowPcEndOffset) =
725 getAttributeOffsets(Abbrev, *LowPcIdx, Offset, *DIE.getDwarfUnit());
726 return hasValidRelocationAt(ValidDebugInfoRelocs, LowPcOffset,
727 LowPcEndOffset, MyInfo);
728 }
729
730 if (Form == dwarf::DW_FORM_addrx) {
731 Optional<DWARFFormValue> AddrValue = DIE.find(dwarf::DW_AT_low_pc);
732 if (Optional<uint64_t> AddrOffsetSectionBase =
733 DIE.getDwarfUnit()->getAddrOffsetSectionBase()) {
734 uint64_t StartOffset = *AddrOffsetSectionBase + AddrValue->getRawUValue();
735 uint64_t EndOffset =
736 StartOffset + DIE.getDwarfUnit()->getAddressByteSize();
737 return hasValidRelocationAt(ValidDebugAddrRelocs, StartOffset, EndOffset,
738 MyInfo);
739 } else
740 Linker.reportWarning("no base offset for address table", SrcFileName);
741 }
742
743 return false;
744}
745
746uint64_t
747DwarfLinkerForBinary::AddressManager::relocate(const ValidReloc &Reloc) const {
748 return Reloc.Mapping->getValue().BinaryAddress + Reloc.Addend;
749}
750
751/// Apply the valid relocations found by findValidRelocs() to
752/// the buffer \p Data, taking into account that Data is at \p BaseOffset
753/// in the debug_info section.
754///
755/// Like for findValidRelocs(), this function must be called with
756/// monotonic \p BaseOffset values.
757///
758/// \returns whether any reloc has been applied.
759bool DwarfLinkerForBinary::AddressManager::applyValidRelocs(
760 MutableArrayRef<char> Data, uint64_t BaseOffset, bool IsLittleEndian) {
761 assert(areRelocationsResolved())(static_cast <bool> (areRelocationsResolved()) ? void (
0) : __assert_fail ("areRelocationsResolved()", "llvm/tools/dsymutil/DwarfLinkerForBinary.cpp"
, 761, __extension__ __PRETTY_FUNCTION__))
;
762 std::vector<ValidReloc> Relocs = getRelocations(
763 ValidDebugInfoRelocs, BaseOffset, BaseOffset + Data.size());
764
765 for (const ValidReloc &CurReloc : Relocs) {
766 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", 766, __extension__
__PRETTY_FUNCTION__))
;
767 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", 767, __extension__
__PRETTY_FUNCTION__))
;
768 char Buf[8];
769 uint64_t Value = relocate(CurReloc);
770 for (unsigned I = 0; I != CurReloc.Size; ++I) {
771 unsigned Index = IsLittleEndian ? I : (CurReloc.Size - I - 1);
772 Buf[I] = uint8_t(Value >> (Index * 8));
773 }
774 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", 774, __extension__
__PRETTY_FUNCTION__))
;
775 memcpy(&Data[CurReloc.Offset - BaseOffset], Buf, CurReloc.Size);
776 }
777
778 return Relocs.size() > 0;
779}
780
781llvm::Expected<uint64_t>
782DwarfLinkerForBinary::AddressManager::relocateIndexedAddr(uint64_t StartOffset,
783 uint64_t EndOffset) {
784 std::vector<ValidReloc> Relocs =
785 getRelocations(ValidDebugAddrRelocs, StartOffset, EndOffset);
786 if (Relocs.size() == 0)
787 return createStringError(
788 std::make_error_code(std::errc::invalid_argument),
789 "no relocation for offset %llu in debug_addr section", StartOffset);
790
791 return relocate(Relocs[0]);
792}
793
794bool linkDwarf(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
795 const DebugMap &DM, LinkOptions Options) {
796 DwarfLinkerForBinary Linker(OutFile, BinHolder, std::move(Options));
797 return Linker.link(DM);
798}
799
800} // namespace dsymutil
801} // namespace llvm

/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/llvm/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
5
Object 'Err' is moved
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 [[noreturn]] void fatalUncheckedError() const;
261#endif
262
263 void assertIsChecked() {
264#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
265 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
266 fatalUncheckedError();
267#endif
268 }
269
270 ErrorInfoBase *getPtr() const {
271#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275#else
276 return Payload;
277#endif
278 }
279
280 void setPtr(ErrorInfoBase *EI) {
281#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
282 Payload = reinterpret_cast<ErrorInfoBase*>(
283 (reinterpret_cast<uintptr_t>(EI) &
284 ~static_cast<uintptr_t>(0x1)) |
285 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
286#else
287 Payload = EI;
288#endif
289 }
290
291 bool getChecked() const {
292#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
293 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
294#else
295 return true;
296#endif
297 }
298
299 void setChecked(bool V) {
300#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
301 Payload = reinterpret_cast<ErrorInfoBase*>(
302 (reinterpret_cast<uintptr_t>(Payload) &
303 ~static_cast<uintptr_t>(0x1)) |
304 (V ? 0 : 1));
305#endif
306 }
307
308 std::unique_ptr<ErrorInfoBase> takePayload() {
309 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
310 setPtr(nullptr);
311 setChecked(true);
312 return Tmp;
313 }
314
315 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
316 if (auto *P = E.getPtr())
317 P->log(OS);
318 else
319 OS << "success";
320 return OS;
321 }
322
323 ErrorInfoBase *Payload = nullptr;
324};
325
326/// Subclass of Error for the sole purpose of identifying the success path in
327/// the type system. This allows to catch invalid conversion to Expected<T> at
328/// compile time.
329class ErrorSuccess final : public Error {};
330
331inline ErrorSuccess Error::success() { return ErrorSuccess(); }
332
333/// Make a Error instance representing failure using the given error info
334/// type.
335template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
336 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
337}
338
339/// Base class for user error types. Users should declare their error types
340/// like:
341///
342/// class MyError : public ErrorInfo<MyError> {
343/// ....
344/// };
345///
346/// This class provides an implementation of the ErrorInfoBase::kind
347/// method, which is used by the Error RTTI system.
348template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
349class ErrorInfo : public ParentErrT {
350public:
351 using ParentErrT::ParentErrT; // inherit constructors
352
353 static const void *classID() { return &ThisErrT::ID; }
354
355 const void *dynamicClassID() const override { return &ThisErrT::ID; }
356
357 bool isA(const void *const ClassID) const override {
358 return ClassID == classID() || ParentErrT::isA(ClassID);
359 }
360};
361
362/// Special ErrorInfo subclass representing a list of ErrorInfos.
363/// Instances of this class are constructed by joinError.
364class ErrorList final : public ErrorInfo<ErrorList> {
365 // handleErrors needs to be able to iterate the payload list of an
366 // ErrorList.
367 template <typename... HandlerTs>
368 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
369
370 // joinErrors is implemented in terms of join.
371 friend Error joinErrors(Error, Error);
372
373public:
374 void log(raw_ostream &OS) const override {
375 OS << "Multiple errors:\n";
376 for (const auto &ErrPayload : Payloads) {
377 ErrPayload->log(OS);
378 OS << "\n";
379 }
380 }
381
382 std::error_code convertToErrorCode() const override;
383
384 // Used by ErrorInfo::classID.
385 static char ID;
386
387private:
388 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
389 std::unique_ptr<ErrorInfoBase> Payload2) {
390 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", 391, __extension__ __PRETTY_FUNCTION__
))
391 "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", 391, __extension__ __PRETTY_FUNCTION__
))
;
392 Payloads.push_back(std::move(Payload1));
393 Payloads.push_back(std::move(Payload2));
394 }
395
396 static Error join(Error E1, Error E2) {
397 if (!E1)
398 return E2;
399 if (!E2)
400 return E1;
401 if (E1.isA<ErrorList>()) {
402 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
403 if (E2.isA<ErrorList>()) {
404 auto E2Payload = E2.takePayload();
405 auto &E2List = static_cast<ErrorList &>(*E2Payload);
406 for (auto &Payload : E2List.Payloads)
407 E1List.Payloads.push_back(std::move(Payload));
408 } else
409 E1List.Payloads.push_back(E2.takePayload());
410
411 return E1;
412 }
413 if (E2.isA<ErrorList>()) {
414 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
415 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
416 return E2;
417 }
418 return Error(std::unique_ptr<ErrorList>(
419 new ErrorList(E1.takePayload(), E2.takePayload())));
420 }
421
422 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
423};
424
425/// Concatenate errors. The resulting Error is unchecked, and contains the
426/// ErrorInfo(s), if any, contained in E1, followed by the
427/// ErrorInfo(s), if any, contained in E2.
428inline Error joinErrors(Error E1, Error E2) {
429 return ErrorList::join(std::move(E1), std::move(E2));
430}
431
432/// Tagged union holding either a T or a Error.
433///
434/// This class parallels ErrorOr, but replaces error_code with Error. Since
435/// Error cannot be copied, this class replaces getError() with
436/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
437/// error class type.
438///
439/// Example usage of 'Expected<T>' as a function return type:
440///
441/// @code{.cpp}
442/// Expected<int> myDivide(int A, int B) {
443/// if (B == 0) {
444/// // return an Error
445/// return createStringError(inconvertibleErrorCode(),
446/// "B must not be zero!");
447/// }
448/// // return an integer
449/// return A / B;
450/// }
451/// @endcode
452///
453/// Checking the results of to a function returning 'Expected<T>':
454/// @code{.cpp}
455/// if (auto E = Result.takeError()) {
456/// // We must consume the error. Typically one of:
457/// // - return the error to our caller
458/// // - toString(), when logging
459/// // - consumeError(), to silently swallow the error
460/// // - handleErrors(), to distinguish error types
461/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
462/// return;
463/// }
464/// // use the result
465/// outs() << "The answer is " << *Result << "\n";
466/// @endcode
467///
468/// For unit-testing a function returning an 'Expceted<T>', see the
469/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
470
471template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
472 template <class T1> friend class ExpectedAsOutParameter;
473 template <class OtherT> friend class Expected;
474
475 static constexpr bool isRef = std::is_reference<T>::value;
476
477 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
478
479 using error_type = std::unique_ptr<ErrorInfoBase>;
480
481public:
482 using storage_type = std::conditional_t<isRef, wrap, T>;
483 using value_type = T;
484
485private:
486 using reference = std::remove_reference_t<T> &;
487 using const_reference = const std::remove_reference_t<T> &;
488 using pointer = std::remove_reference_t<T> *;
489 using const_pointer = const std::remove_reference_t<T> *;
490
491public:
492 /// Create an Expected<T> error value from the given Error.
493 Expected(Error Err)
494 : HasError(true)
495#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
496 // Expected is unchecked upon construction in Debug builds.
497 , Unchecked(true)
498#endif
499 {
500 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", 500, __extension__ __PRETTY_FUNCTION__
))
;
501 new (getErrorStorage()) error_type(Err.takePayload());
502 }
503
504 /// Forbid to convert from Error::success() implicitly, this avoids having
505 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
506 /// but triggers the assertion above.
507 Expected(ErrorSuccess) = delete;
508
509 /// Create an Expected<T> success value from the given OtherT value, which
510 /// must be convertible to T.
511 template <typename OtherT>
512 Expected(OtherT &&Val,
513 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
514 : HasError(false)
515#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
516 // Expected is unchecked upon construction in Debug builds.
517 ,
518 Unchecked(true)
519#endif
520 {
521 new (getStorage()) storage_type(std::forward<OtherT>(Val));
522 }
523
524 /// Move construct an Expected<T> value.
525 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
526
527 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
528 /// must be convertible to T.
529 template <class OtherT>
530 Expected(
531 Expected<OtherT> &&Other,
532 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
533 moveConstruct(std::move(Other));
534 }
535
536 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
537 /// isn't convertible to T.
538 template <class OtherT>
539 explicit Expected(
540 Expected<OtherT> &&Other,
541 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
542 moveConstruct(std::move(Other));
543 }
544
545 /// Move-assign from another Expected<T>.
546 Expected &operator=(Expected &&Other) {
547 moveAssign(std::move(Other));
548 return *this;
549 }
550
551 /// Destroy an Expected<T>.
552 ~Expected() {
553 assertIsChecked();
554 if (!HasError)
555 getStorage()->~storage_type();
556 else
557 getErrorStorage()->~error_type();
558 }
559
560 /// Return false if there is an error.
561 explicit operator bool() {
562#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
563 Unchecked = HasError;
564#endif
565 return !HasError;
566 }
567
568 /// Returns a reference to the stored T value.
569 reference get() {
570 assertIsChecked();
571 return *getStorage();
572 }
573
574 /// Returns a const reference to the stored T value.
575 const_reference get() const {
576 assertIsChecked();
577 return const_cast<Expected<T> *>(this)->get();
578 }
579
580 /// Returns \a takeError() after moving the held T (if any) into \p V.
581 template <class OtherT>
582 Error moveInto(OtherT &Value,
583 std::enable_if_t<std::is_assignable<OtherT &, T &&>::value> * =
584 nullptr) && {
585 if (*this)
586 Value = std::move(get());
587 return takeError();
588 }
589
590 /// Check that this Expected<T> is an error of type ErrT.
591 template <typename ErrT> bool errorIsA() const {
592 return HasError && (*getErrorStorage())->template isA<ErrT>();
593 }
594
595 /// Take ownership of the stored error.
596 /// After calling this the Expected<T> is in an indeterminate state that can
597 /// only be safely destructed. No further calls (beside the destructor) should
598 /// be made on the Expected<T> value.
599 Error takeError() {
600#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
601 Unchecked = false;
602#endif
603 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
604 }
605
606 /// Returns a pointer to the stored T value.
607 pointer operator->() {
608 assertIsChecked();
609 return toPointer(getStorage());
610 }
611
612 /// Returns a const pointer to the stored T value.
613 const_pointer operator->() const {
614 assertIsChecked();
615 return toPointer(getStorage());
616 }
617
618 /// Returns a reference to the stored T value.
619 reference operator*() {
620 assertIsChecked();
621 return *getStorage();
622 }
623
624 /// Returns a const reference to the stored T value.
625 const_reference operator*() const {
626 assertIsChecked();
627 return *getStorage();
628 }
629
630private:
631 template <class T1>
632 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
633 return &a == &b;
634 }
635
636 template <class T1, class T2>
637 static bool compareThisIfSameType(const T1 &, const T2 &) {
638 return false;
639 }
640
641 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
642 HasError = Other.HasError;
643#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
644 Unchecked = true;
645 Other.Unchecked = false;
646#endif
647
648 if (!HasError)
649 new (getStorage()) storage_type(std::move(*Other.getStorage()));
650 else
651 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
652 }
653
654 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
655 assertIsChecked();
656
657 if (compareThisIfSameType(*this, Other))
658 return;
659
660 this->~Expected();
661 new (this) Expected(std::move(Other));
662 }
663
664 pointer toPointer(pointer Val) { return Val; }
665
666 const_pointer toPointer(const_pointer Val) const { return Val; }
667
668 pointer toPointer(wrap *Val) { return &Val->get(); }
669
670 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
671
672 storage_type *getStorage() {
673 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", 673, __extension__ __PRETTY_FUNCTION__
))
;
674 return reinterpret_cast<storage_type *>(&TStorage);
675 }
676
677 const storage_type *getStorage() const {
678 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", 678, __extension__ __PRETTY_FUNCTION__
))
;
679 return reinterpret_cast<const storage_type *>(&TStorage);
680 }
681
682 error_type *getErrorStorage() {
683 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", 683, __extension__ __PRETTY_FUNCTION__
))
;
684 return reinterpret_cast<error_type *>(&ErrorStorage);
685 }
686
687 const error_type *getErrorStorage() const {
688 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", 688, __extension__ __PRETTY_FUNCTION__
))
;
689 return reinterpret_cast<const error_type *>(&ErrorStorage);
690 }
691
692 // Used by ExpectedAsOutParameter to reset the checked flag.
693 void setUnchecked() {
694#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
695 Unchecked = true;
696#endif
697 }
698
699#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
700 [[noreturn]] LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline)) void fatalUncheckedExpected() const {
701 dbgs() << "Expected<T> must be checked before access or destruction.\n";
702 if (HasError) {
703 dbgs() << "Unchecked Expected<T> contained error:\n";
704 (*getErrorStorage())->log(dbgs());
705 } else
706 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
707 "values in success mode must still be checked prior to being "
708 "destroyed).\n";
709 abort();
710 }
711#endif
712
713 void assertIsChecked() const {
714#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
715 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
716 fatalUncheckedExpected();
717#endif
718 }
719
720 union {
721 AlignedCharArrayUnion<storage_type> TStorage;
722 AlignedCharArrayUnion<error_type> ErrorStorage;
723 };
724 bool HasError : 1;
725#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
726 bool Unchecked : 1;
727#endif
728};
729
730/// Report a serious error, calling any installed error handler. See
731/// ErrorHandling.h.
732[[noreturn]] void report_fatal_error(Error Err, bool gen_crash_diag = true);
733
734/// Report a fatal error if Err is a failure value.
735///
736/// This function can be used to wrap calls to fallible functions ONLY when it
737/// is known that the Error will always be a success value. E.g.
738///
739/// @code{.cpp}
740/// // foo only attempts the fallible operation if DoFallibleOperation is
741/// // true. If DoFallibleOperation is false then foo always returns
742/// // Error::success().
743/// Error foo(bool DoFallibleOperation);
744///
745/// cantFail(foo(false));
746/// @endcode
747inline void cantFail(Error Err, const char *Msg = nullptr) {
748 if (Err) {
749 if (!Msg)
750 Msg = "Failure value returned from cantFail wrapped call";
751#ifndef NDEBUG
752 std::string Str;
753 raw_string_ostream OS(Str);
754 OS << Msg << "\n" << Err;
755 Msg = OS.str().c_str();
756#endif
757 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 757)
;
758 }
759}
760
761/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
762/// returns the contained value.
763///
764/// This function can be used to wrap calls to fallible functions ONLY when it
765/// is known that the Error will always be a success value. E.g.
766///
767/// @code{.cpp}
768/// // foo only attempts the fallible operation if DoFallibleOperation is
769/// // true. If DoFallibleOperation is false then foo always returns an int.
770/// Expected<int> foo(bool DoFallibleOperation);
771///
772/// int X = cantFail(foo(false));
773/// @endcode
774template <typename T>
775T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
776 if (ValOrErr)
777 return std::move(*ValOrErr);
778 else {
779 if (!Msg)
780 Msg = "Failure value returned from cantFail wrapped call";
781#ifndef NDEBUG
782 std::string Str;
783 raw_string_ostream OS(Str);
784 auto E = ValOrErr.takeError();
785 OS << Msg << "\n" << E;
786 Msg = OS.str().c_str();
787#endif
788 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 788)
;
789 }
790}
791
792/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
793/// returns the contained reference.
794///
795/// This function can be used to wrap calls to fallible functions ONLY when it
796/// is known that the Error will always be a success value. E.g.
797///
798/// @code{.cpp}
799/// // foo only attempts the fallible operation if DoFallibleOperation is
800/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
801/// Expected<Bar&> foo(bool DoFallibleOperation);
802///
803/// Bar &X = cantFail(foo(false));
804/// @endcode
805template <typename T>
806T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
807 if (ValOrErr)
808 return *ValOrErr;
809 else {
810 if (!Msg)
811 Msg = "Failure value returned from cantFail wrapped call";
812#ifndef NDEBUG
813 std::string Str;
814 raw_string_ostream OS(Str);
815 auto E = ValOrErr.takeError();
816 OS << Msg << "\n" << E;
817 Msg = OS.str().c_str();
818#endif
819 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h"
, 819)
;
820 }
821}
822
823/// Helper for testing applicability of, and applying, handlers for
824/// ErrorInfo types.
825template <typename HandlerT>
826class ErrorHandlerTraits
827 : public ErrorHandlerTraits<decltype(
828 &std::remove_reference<HandlerT>::type::operator())> {};
829
830// Specialization functions of the form 'Error (const ErrT&)'.
831template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
832public:
833 static bool appliesTo(const ErrorInfoBase &E) {
834 return E.template isA<ErrT>();
835 }
836
837 template <typename HandlerT>
838 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
839 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", 839, __extension__ __PRETTY_FUNCTION__
))
;
840 return H(static_cast<ErrT &>(*E));
841 }
842};
843
844// Specialization functions of the form 'void (const ErrT&)'.
845template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
846public:
847 static bool appliesTo(const ErrorInfoBase &E) {
848 return E.template isA<ErrT>();
849 }
850
851 template <typename HandlerT>
852 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
853 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", 853, __extension__ __PRETTY_FUNCTION__
))
;
854 H(static_cast<ErrT &>(*E));
855 return Error::success();
856 }
857};
858
859/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
860template <typename ErrT>
861class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
862public:
863 static bool appliesTo(const ErrorInfoBase &E) {
864 return E.template isA<ErrT>();
865 }
866
867 template <typename HandlerT>
868 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
869 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", 869, __extension__ __PRETTY_FUNCTION__
))
;
870 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
871 return H(std::move(SubE));
872 }
873};
874
875/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
876template <typename ErrT>
877class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
878public:
879 static bool appliesTo(const ErrorInfoBase &E) {
880 return E.template isA<ErrT>();
881 }
882
883 template <typename HandlerT>
884 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
885 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", 885, __extension__ __PRETTY_FUNCTION__
))
;
886 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
887 H(std::move(SubE));
888 return Error::success();
889 }
890};
891
892// Specialization for member functions of the form 'RetT (const ErrT&)'.
893template <typename C, typename RetT, typename ErrT>
894class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
895 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
896
897// Specialization for member functions of the form 'RetT (const ErrT&) const'.
898template <typename C, typename RetT, typename ErrT>
899class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
900 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
901
902// Specialization for member functions of the form 'RetT (const ErrT&)'.
903template <typename C, typename RetT, typename ErrT>
904class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
905 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
906
907// Specialization for member functions of the form 'RetT (const ErrT&) const'.
908template <typename C, typename RetT, typename ErrT>
909class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
910 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
911
912/// Specialization for member functions of the form
913/// 'RetT (std::unique_ptr<ErrT>)'.
914template <typename C, typename RetT, typename ErrT>
915class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
916 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
917
918/// Specialization for member functions of the form
919/// 'RetT (std::unique_ptr<ErrT>) const'.
920template <typename C, typename RetT, typename ErrT>
921class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
922 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
923
924inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
925 return Error(std::move(Payload));
926}
927
928template <typename HandlerT, typename... HandlerTs>
929Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
930 HandlerT &&Handler, HandlerTs &&... Handlers) {
931 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
932 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
933 std::move(Payload));
934 return handleErrorImpl(std::move(Payload),
935 std::forward<HandlerTs>(Handlers)...);
936}
937
938/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
939/// unhandled errors (or Errors returned by handlers) are re-concatenated and
940/// returned.
941/// Because this function returns an error, its result must also be checked
942/// or returned. If you intend to handle all errors use handleAllErrors
943/// (which returns void, and will abort() on unhandled errors) instead.
944template <typename... HandlerTs>
945Error handleErrors(Error E, HandlerTs &&... Hs) {
946 if (!E)
947 return Error::success();
948
949 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
950
951 if (Payload->isA<ErrorList>()) {
952 ErrorList &List = static_cast<ErrorList &>(*Payload);
953 Error R;
954 for (auto &P : List.Payloads)
955 R = ErrorList::join(
956 std::move(R),
957 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
958 return R;
959 }
960
961 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
962}
963
964/// Behaves the same as handleErrors, except that by contract all errors
965/// *must* be handled by the given handlers (i.e. there must be no remaining
966/// errors after running the handlers, or llvm_unreachable is called).
967template <typename... HandlerTs>
968void handleAllErrors(Error E, HandlerTs &&... Handlers) {
969 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
970}
971
972/// Check that E is a non-error, then drop it.
973/// If E is an error, llvm_unreachable will be called.
974inline void handleAllErrors(Error E) {
975 cantFail(std::move(E));
976}
977
978/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
979///
980/// If the incoming value is a success value it is returned unmodified. If it
981/// is a failure value then it the contained error is passed to handleErrors.
982/// If handleErrors is able to handle the error then the RecoveryPath functor
983/// is called to supply the final result. If handleErrors is not able to
984/// handle all errors then the unhandled errors are returned.
985///
986/// This utility enables the follow pattern:
987///
988/// @code{.cpp}
989/// enum FooStrategy { Aggressive, Conservative };
990/// Expected<Foo> foo(FooStrategy S);
991///
992/// auto ResultOrErr =
993/// handleExpected(
994/// foo(Aggressive),
995/// []() { return foo(Conservative); },
996/// [](AggressiveStrategyError&) {
997/// // Implicitly conusme this - we'll recover by using a conservative
998/// // strategy.
999/// });
1000///
1001/// @endcode
1002template <typename T, typename RecoveryFtor, typename... HandlerTs>
1003Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
1004 HandlerTs &&... Handlers) {
1005 if (ValOrErr)
1006 return ValOrErr;
1007
1008 if (auto Err = handleErrors(ValOrErr.takeError(),
1009 std::forward<HandlerTs>(Handlers)...))
1010 return std::move(Err);
1011
1012 return RecoveryPath();
1013}
1014
1015/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1016/// will be printed before the first one is logged. A newline will be printed
1017/// after each error.
1018///
1019/// This function is compatible with the helpers from Support/WithColor.h. You
1020/// can pass any of them as the OS. Please consider using them instead of
1021/// including 'error: ' in the ErrorBanner.
1022///
1023/// This is useful in the base level of your program to allow clean termination
1024/// (allowing clean deallocation of resources, etc.), while reporting error
1025/// information to the user.
1026void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1027
1028/// Write all error messages (if any) in E to a string. The newline character
1029/// is used to separate error messages.
1030inline std::string toString(Error E) {
1031 SmallVector<std::string, 2> Errors;
1032 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1033 Errors.push_back(EI.message());
1034 });
1035 return join(Errors.begin(), Errors.end(), "\n");
1036}
1037
1038/// Consume a Error without doing anything. This method should be used
1039/// only where an error can be considered a reasonable and expected return
1040/// value.
1041///
1042/// Uses of this method are potentially indicative of design problems: If it's
1043/// legitimate to do nothing while processing an "error", the error-producer
1044/// might be more clearly refactored to return an Optional<T>.
1045inline void consumeError(Error Err) {
1046 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1047}
1048
1049/// Convert an Expected to an Optional without doing anything. This method
1050/// should be used only where an error can be considered a reasonable and
1051/// expected return value.
1052///
1053/// Uses of this method are potentially indicative of problems: perhaps the
1054/// error should be propagated further, or the error-producer should just
1055/// return an Optional in the first place.
1056template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1057 if (E)
1058 return std::move(*E);
1059 consumeError(E.takeError());
1060 return None;
1061}
1062
1063/// Helper for converting an Error to a bool.
1064///
1065/// This method returns true if Err is in an error state, or false if it is
1066/// in a success state. Puts Err in a checked state in both cases (unlike
1067/// Error::operator bool(), which only does this for success states).
1068inline bool errorToBool(Error Err) {
1069 bool IsError = static_cast<bool>(Err);
1070 if (IsError)
1071 consumeError(std::move(Err));
1072 return IsError;
1073}
1074
1075/// Helper for Errors used as out-parameters.
1076///
1077/// This helper is for use with the Error-as-out-parameter idiom, where an error
1078/// is passed to a function or method by reference, rather than being returned.
1079/// In such cases it is helpful to set the checked bit on entry to the function
1080/// so that the error can be written to (unchecked Errors abort on assignment)
1081/// and clear the checked bit on exit so that clients cannot accidentally forget
1082/// to check the result. This helper performs these actions automatically using
1083/// RAII:
1084///
1085/// @code{.cpp}
1086/// Result foo(Error &Err) {
1087/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1088/// // <body of foo>
1089/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1090/// }
1091/// @endcode
1092///
1093/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1094/// used with optional Errors (Error pointers that are allowed to be null). If
1095/// ErrorAsOutParameter took an Error reference, an instance would have to be
1096/// created inside every condition that verified that Error was non-null. By
1097/// taking an Error pointer we can just create one instance at the top of the
1098/// function.
1099class ErrorAsOutParameter {
1100public:
1101 ErrorAsOutParameter(Error *Err) : Err(Err) {
1102 // Raise the checked bit if Err is success.
1103 if (Err)
1104 (void)!!*Err;
1105 }
1106
1107 ~ErrorAsOutParameter() {
1108 // Clear the checked bit.
1109 if (Err && !*Err)
1110 *Err = Error::success();
1111 }
1112
1113private:
1114 Error *Err;
1115};
1116
1117/// Helper for Expected<T>s used as out-parameters.
1118///
1119/// See ErrorAsOutParameter.
1120template <typename T>
1121class ExpectedAsOutParameter {
1122public:
1123 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1124 : ValOrErr(ValOrErr) {
1125 if (ValOrErr)
1126 (void)!!*ValOrErr;
1127 }
1128
1129 ~ExpectedAsOutParameter() {
1130 if (ValOrErr)
1131 ValOrErr->setUnchecked();
1132 }
1133
1134private:
1135 Expected<T> *ValOrErr;
1136};
1137
1138/// This class wraps a std::error_code in a Error.
1139///
1140/// This is useful if you're writing an interface that returns a Error
1141/// (or Expected) and you want to call code that still returns
1142/// std::error_codes.
1143class ECError : public ErrorInfo<ECError> {
1144 friend Error errorCodeToError(std::error_code);
1145
1146 virtual void anchor() override;
1147
1148public:
1149 void setErrorCode(std::error_code EC) { this->EC = EC; }
1150 std::error_code convertToErrorCode() const override { return EC; }
1151 void log(raw_ostream &OS) const override { OS << EC.message(); }
1152
1153 // Used by ErrorInfo::classID.
1154 static char ID;
1155
1156protected:
1157 ECError() = default;
1158 ECError(std::error_code EC) : EC(EC) {}
1159
1160 std::error_code EC;
1161};
1162
1163/// The value returned by this function can be returned from convertToErrorCode
1164/// for Error values where no sensible translation to std::error_code exists.
1165/// It should only be used in this situation, and should never be used where a
1166/// sensible conversion to std::error_code is available, as attempts to convert
1167/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1168/// error to try to convert such a value).
1169std::error_code inconvertibleErrorCode();
1170
1171/// Helper for converting an std::error_code to a Error.
1172Error errorCodeToError(std::error_code EC);
1173
1174/// Helper for converting an ECError to a std::error_code.
1175///
1176/// This method requires that Err be Error() or an ECError, otherwise it
1177/// will trigger a call to abort().
1178std::error_code errorToErrorCode(Error Err);
1179
1180/// Convert an ErrorOr<T> to an Expected<T>.
1181template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1182 if (auto EC = EO.getError())
1183 return errorCodeToError(EC);
1184 return std::move(*EO);
1185}
1186
1187/// Convert an Expected<T> to an ErrorOr<T>.
1188template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1189 if (auto Err = E.takeError())
1190 return errorToErrorCode(std::move(Err));
1191 return std::move(*E);
1192}
1193
1194/// This class wraps a string in an Error.
1195///
1196/// StringError is useful in cases where the client is not expected to be able
1197/// to consume the specific error message programmatically (for example, if the
1198/// error message is to be presented to the user).
1199///
1200/// StringError can also be used when additional information is to be printed
1201/// along with a error_code message. Depending on the constructor called, this
1202/// class can either display:
1203/// 1. the error_code message (ECError behavior)
1204/// 2. a string
1205/// 3. the error_code message and a string
1206///
1207/// These behaviors are useful when subtyping is required; for example, when a
1208/// specific library needs an explicit error type. In the example below,
1209/// PDBError is derived from StringError:
1210///
1211/// @code{.cpp}
1212/// Expected<int> foo() {
1213/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1214/// "Additional information");
1215/// }
1216/// @endcode
1217///
1218class StringError : public ErrorInfo<StringError> {
1219public:
1220 static char ID;
1221
1222 // Prints EC + S and converts to EC
1223 StringError(std::error_code EC, const Twine &S = Twine());
1224
1225 // Prints S and converts to EC
1226 StringError(const Twine &S, std::error_code EC);
1227
1228 void log(raw_ostream &OS) const override;
1229 std::error_code convertToErrorCode() const override;
1230
1231 const std::string &getMessage() const { return Msg; }
1232
1233private:
1234 std::string Msg;
1235 std::error_code EC;
1236 const bool PrintMsgOnly = false;
1237};
1238
1239/// Create formatted StringError object.
1240template <typename... Ts>
1241inline Error createStringError(std::error_code EC, char const *Fmt,
1242 const Ts &... Vals) {
1243 std::string Buffer;
1244 raw_string_ostream Stream(Buffer);
1245 Stream << format(Fmt, Vals...);
1246 return make_error<StringError>(Stream.str(), EC);
1247}
1248
1249Error createStringError(std::error_code EC, char const *Msg);
1250
1251inline Error createStringError(std::error_code EC, const Twine &S) {
1252 return createStringError(EC, S.str().c_str());
1253}
1254
1255template <typename... Ts>
1256inline Error createStringError(std::errc EC, char const *Fmt,
1257 const Ts &... Vals) {
1258 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1259}
1260
1261/// This class wraps a filename and another Error.
1262///
1263/// In some cases, an error needs to live along a 'source' name, in order to
1264/// show more detailed information to the user.
1265class FileError final : public ErrorInfo<FileError> {
1266
1267 friend Error createFileError(const Twine &, Error);
1268 friend Error createFileError(const Twine &, size_t, Error);
1269
1270public:
1271 void log(raw_ostream &OS) const override {
1272 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", 1272, __extension__ __PRETTY_FUNCTION__
))
;
1273 OS << "'" << FileName << "': ";
1274 if (Line.hasValue())
1275 OS << "line " << Line.getValue() << ": ";
1276 Err->log(OS);
1277 }
1278
1279 std::string messageWithoutFileInfo() const {
1280 std::string Msg;
1281 raw_string_ostream OS(Msg);
1282 Err->log(OS);
1283 return OS.str();
1284 }
1285
1286 StringRef getFileName() { return FileName; }
1287
1288 Error takeError() { return Error(std::move(Err)); }
1289
1290 std::error_code convertToErrorCode() const override;
1291
1292 // Used by ErrorInfo::classID.
1293 static char ID;
1294
1295private:
1296 FileError(const Twine &F, Optional<size_t> LineNum,
1297 std::unique_ptr<ErrorInfoBase> E) {
1298 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", 1298, __extension__ __PRETTY_FUNCTION__
))
;
1299 FileName = F.str();
1300 Err = std::move(E);
1301 Line = std::move(LineNum);
1302 }
1303
1304 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1305 std::unique_ptr<ErrorInfoBase> Payload;
1306 handleAllErrors(std::move(E),
1307 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1308 Payload = std::move(EIB);
1309 return Error::success();
1310 });
1311 return Error(
1312 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1313 }
1314
1315 std::string FileName;
1316 Optional<size_t> Line;
1317 std::unique_ptr<ErrorInfoBase> Err;
1318};
1319
1320/// Concatenate a source file path and/or name with an Error. The resulting
1321/// Error is unchecked.
1322inline Error createFileError(const Twine &F, Error E) {
1323 return FileError::build(F, Optional<size_t>(), std::move(E));
1324}
1325
1326/// Concatenate a source file path and/or name with line number and an Error.
1327/// The resulting Error is unchecked.
1328inline Error createFileError(const Twine &F, size_t Line, Error E) {
1329 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1330}
1331
1332/// Concatenate a source file path and/or name with a std::error_code
1333/// to form an Error object.
1334inline Error createFileError(const Twine &F, std::error_code EC) {
1335 return createFileError(F, errorCodeToError(EC));
1336}
1337
1338/// Concatenate a source file path and/or name with line number and
1339/// std::error_code to form an Error object.
1340inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1341 return createFileError(F, Line, errorCodeToError(EC));
1342}
1343
1344Error createFileError(const Twine &F, ErrorSuccess) = delete;
1345
1346/// Helper for check-and-exit error handling.
1347///
1348/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1349///
1350class ExitOnError {
1351public:
1352 /// Create an error on exit helper.
1353 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1354 : Banner(std::move(Banner)),
1355 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1356
1357 /// Set the banner string for any errors caught by operator().
1358 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1359
1360 /// Set the exit-code mapper function.
1361 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1362 this->GetExitCode = std::move(GetExitCode);
1363 }
1364
1365 /// Check Err. If it's in a failure state log the error(s) and exit.
1366 void operator()(Error Err) const { checkError(std::move(Err)); }
1367
1368 /// Check E. If it's in a success state then return the contained value. If
1369 /// it's in a failure state log the error(s) and exit.
1370 template <typename T> T operator()(Expected<T> &&E) const {
1371 checkError(E.takeError());
1372 return std::move(*E);
1373 }
1374
1375 /// Check E. If it's in a success state then return the contained reference. If
1376 /// it's in a failure state log the error(s) and exit.
1377 template <typename T> T& operator()(Expected<T&> &&E) const {
1378 checkError(E.takeError());
1379 return *E;
1380 }
1381
1382private:
1383 void checkError(Error Err) const {
1384 if (Err) {
1385 int ExitCode = GetExitCode(Err);
1386 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1387 exit(ExitCode);
1388 }
1389 }
1390
1391 std::string Banner;
1392 std::function<int(const Error &)> GetExitCode;
1393};
1394
1395/// Conversion from Error to LLVMErrorRef for C error bindings.
1396inline LLVMErrorRef wrap(Error Err) {
1397 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1398}
1399
1400/// Conversion from LLVMErrorRef to Error for C error bindings.
1401inline Error unwrap(LLVMErrorRef ErrRef) {
1402 return Error(std::unique_ptr<ErrorInfoBase>(
1403 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1404}
1405
1406} // end namespace llvm
1407
1408#endif // LLVM_SUPPORT_ERROR_H