Bug Summary

File:include/llvm/Support/Error.h
Warning:line 201, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ArchiveWriter.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 -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/Object -I /build/llvm-toolchain-snapshot-8~svn345461/lib/Object -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/Object -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp

1//===- ArchiveWriter.cpp - ar File Format implementation --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the writeArchive function.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Object/ArchiveWriter.h"
15#include "llvm/ADT/ArrayRef.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/BinaryFormat/Magic.h"
18#include "llvm/IR/LLVMContext.h"
19#include "llvm/Object/Archive.h"
20#include "llvm/Object/ObjectFile.h"
21#include "llvm/Object/SymbolicFile.h"
22#include "llvm/Support/EndianStream.h"
23#include "llvm/Support/Errc.h"
24#include "llvm/Support/ErrorHandling.h"
25#include "llvm/Support/Format.h"
26#include "llvm/Support/Path.h"
27#include "llvm/Support/ToolOutputFile.h"
28#include "llvm/Support/raw_ostream.h"
29
30#include <map>
31
32#if !defined(_MSC_VER) && !defined(__MINGW32__)
33#include <unistd.h>
34#else
35#include <io.h>
36#endif
37
38using namespace llvm;
39
40NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
41 : Buf(MemoryBuffer::getMemBuffer(BufRef, false)),
42 MemberName(BufRef.getBufferIdentifier()) {}
43
44Expected<NewArchiveMember>
45NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
46 bool Deterministic) {
47 Expected<llvm::MemoryBufferRef> BufOrErr = OldMember.getMemoryBufferRef();
48 if (!BufOrErr)
49 return BufOrErr.takeError();
50
51 NewArchiveMember M;
52 assert(M.IsNew == false)((M.IsNew == false) ? static_cast<void> (0) : __assert_fail
("M.IsNew == false", "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 52, __PRETTY_FUNCTION__))
;
53 M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
54 M.MemberName = M.Buf->getBufferIdentifier();
55 if (!Deterministic) {
56 auto ModTimeOrErr = OldMember.getLastModified();
57 if (!ModTimeOrErr)
58 return ModTimeOrErr.takeError();
59 M.ModTime = ModTimeOrErr.get();
60 Expected<unsigned> UIDOrErr = OldMember.getUID();
61 if (!UIDOrErr)
62 return UIDOrErr.takeError();
63 M.UID = UIDOrErr.get();
64 Expected<unsigned> GIDOrErr = OldMember.getGID();
65 if (!GIDOrErr)
66 return GIDOrErr.takeError();
67 M.GID = GIDOrErr.get();
68 Expected<sys::fs::perms> AccessModeOrErr = OldMember.getAccessMode();
69 if (!AccessModeOrErr)
70 return AccessModeOrErr.takeError();
71 M.Perms = AccessModeOrErr.get();
72 }
73 return std::move(M);
74}
75
76Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
77 bool Deterministic) {
78 sys::fs::file_status Status;
79 int FD;
80 if (auto EC = sys::fs::openFileForRead(FileName, FD))
81 return errorCodeToError(EC);
82 assert(FD != -1)((FD != -1) ? static_cast<void> (0) : __assert_fail ("FD != -1"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 82, __PRETTY_FUNCTION__))
;
83
84 if (auto EC = sys::fs::status(FD, Status))
85 return errorCodeToError(EC);
86
87 // Opening a directory doesn't make sense. Let it fail.
88 // Linux cannot open directories with open(2), although
89 // cygwin and *bsd can.
90 if (Status.type() == sys::fs::file_type::directory_file)
91 return errorCodeToError(make_error_code(errc::is_a_directory));
92
93 ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
94 MemoryBuffer::getOpenFile(FD, FileName, Status.getSize(), false);
95 if (!MemberBufferOrErr)
96 return errorCodeToError(MemberBufferOrErr.getError());
97
98 if (close(FD) != 0)
99 return errorCodeToError(std::error_code(errno(*__errno_location ()), std::generic_category()));
100
101 NewArchiveMember M;
102 M.IsNew = true;
103 M.Buf = std::move(*MemberBufferOrErr);
104 M.MemberName = M.Buf->getBufferIdentifier();
105 if (!Deterministic) {
106 M.ModTime = std::chrono::time_point_cast<std::chrono::seconds>(
107 Status.getLastModificationTime());
108 M.UID = Status.getUser();
109 M.GID = Status.getGroup();
110 M.Perms = Status.permissions();
111 }
112 return std::move(M);
113}
114
115template <typename T>
116static void printWithSpacePadding(raw_ostream &OS, T Data, unsigned Size) {
117 uint64_t OldPos = OS.tell();
118 OS << Data;
119 unsigned SizeSoFar = OS.tell() - OldPos;
120 assert(SizeSoFar <= Size && "Data doesn't fit in Size")((SizeSoFar <= Size && "Data doesn't fit in Size")
? static_cast<void> (0) : __assert_fail ("SizeSoFar <= Size && \"Data doesn't fit in Size\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 120, __PRETTY_FUNCTION__))
;
121 OS.indent(Size - SizeSoFar);
122}
123
124static bool isDarwin(object::Archive::Kind Kind) {
125 return Kind == object::Archive::K_DARWIN ||
126 Kind == object::Archive::K_DARWIN64;
127}
128
129static bool isBSDLike(object::Archive::Kind Kind) {
130 switch (Kind) {
131 case object::Archive::K_GNU:
132 case object::Archive::K_GNU64:
133 return false;
134 case object::Archive::K_BSD:
135 case object::Archive::K_DARWIN:
136 case object::Archive::K_DARWIN64:
137 return true;
138 case object::Archive::K_COFF:
139 break;
140 }
141 llvm_unreachable("not supported for writting")::llvm::llvm_unreachable_internal("not supported for writting"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 141)
;
142}
143
144template <class T>
145static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val) {
146 support::endian::write(Out, Val,
147 isBSDLike(Kind) ? support::little : support::big);
148}
149
150static void printRestOfMemberHeader(
151 raw_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
152 unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
153 printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
154
155 // The format has only 6 chars for uid and gid. Truncate if the provided
156 // values don't fit.
157 printWithSpacePadding(Out, UID % 1000000, 6);
158 printWithSpacePadding(Out, GID % 1000000, 6);
159
160 printWithSpacePadding(Out, format("%o", Perms), 8);
161 printWithSpacePadding(Out, Size, 10);
162 Out << "`\n";
163}
164
165static void
166printGNUSmallMemberHeader(raw_ostream &Out, StringRef Name,
167 const sys::TimePoint<std::chrono::seconds> &ModTime,
168 unsigned UID, unsigned GID, unsigned Perms,
169 unsigned Size) {
170 printWithSpacePadding(Out, Twine(Name) + "/", 16);
171 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
172}
173
174static void
175printBSDMemberHeader(raw_ostream &Out, uint64_t Pos, StringRef Name,
176 const sys::TimePoint<std::chrono::seconds> &ModTime,
177 unsigned UID, unsigned GID, unsigned Perms,
178 unsigned Size) {
179 uint64_t PosAfterHeader = Pos + 60 + Name.size();
180 // Pad so that even 64 bit object files are aligned.
181 unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
182 unsigned NameWithPadding = Name.size() + Pad;
183 printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
184 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
185 NameWithPadding + Size);
186 Out << Name;
187 while (Pad--)
188 Out.write(uint8_t(0));
189}
190
191static bool useStringTable(bool Thin, StringRef Name) {
192 return Thin || Name.size() >= 16 || Name.contains('/');
193}
194
195// Compute the relative path from From to To.
196static std::string computeRelativePath(StringRef From, StringRef To) {
197 if (sys::path::is_absolute(From) || sys::path::is_absolute(To))
198 return To;
199
200 StringRef DirFrom = sys::path::parent_path(From);
201 auto FromI = sys::path::begin(DirFrom);
202 auto ToI = sys::path::begin(To);
203 while (*FromI == *ToI) {
204 ++FromI;
205 ++ToI;
206 }
207
208 SmallString<128> Relative;
209 for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
210 sys::path::append(Relative, "..");
211
212 for (auto ToE = sys::path::end(To); ToI != ToE; ++ToI)
213 sys::path::append(Relative, *ToI);
214
215#ifdef _WIN32
216 // Replace backslashes with slashes so that the path is portable between *nix
217 // and Windows.
218 std::replace(Relative.begin(), Relative.end(), '\\', '/');
219#endif
220
221 return Relative.str();
222}
223
224static bool is64BitKind(object::Archive::Kind Kind) {
225 switch (Kind) {
226 case object::Archive::K_GNU:
227 case object::Archive::K_BSD:
228 case object::Archive::K_DARWIN:
229 case object::Archive::K_COFF:
230 return false;
231 case object::Archive::K_DARWIN64:
232 case object::Archive::K_GNU64:
233 return true;
234 }
235 llvm_unreachable("not supported for writting")::llvm::llvm_unreachable_internal("not supported for writting"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 235)
;
236}
237
238static void addToStringTable(raw_ostream &Out, StringRef ArcName,
239 const NewArchiveMember &M, bool Thin) {
240 StringRef ID = M.Buf->getBufferIdentifier();
241 if (Thin) {
242 if (M.IsNew)
243 Out << computeRelativePath(ArcName, ID);
244 else
245 Out << ID;
246 } else
247 Out << M.MemberName;
248 Out << "/\n";
249}
250
251static void printMemberHeader(raw_ostream &Out, uint64_t Pos,
252 raw_ostream &StringTable,
253 object::Archive::Kind Kind, bool Thin,
254 StringRef ArcName, const NewArchiveMember &M,
255 sys::TimePoint<std::chrono::seconds> ModTime,
256 unsigned Size) {
257
258 if (isBSDLike(Kind))
259 return printBSDMemberHeader(Out, Pos, M.MemberName, ModTime, M.UID, M.GID,
260 M.Perms, Size);
261 if (!useStringTable(Thin, M.MemberName))
262 return printGNUSmallMemberHeader(Out, M.MemberName, ModTime, M.UID, M.GID,
263 M.Perms, Size);
264 Out << '/';
265 uint64_t NamePos = StringTable.tell();
266 addToStringTable(StringTable, ArcName, M, Thin);
267 printWithSpacePadding(Out, NamePos, 15);
268 printRestOfMemberHeader(Out, ModTime, M.UID, M.GID, M.Perms, Size);
269}
270
271namespace {
272struct MemberData {
273 std::vector<unsigned> Symbols;
274 std::string Header;
275 StringRef Data;
276 StringRef Padding;
277};
278} // namespace
279
280static MemberData computeStringTable(StringRef Names) {
281 unsigned Size = Names.size();
282 unsigned Pad = OffsetToAlignment(Size, 2);
283 std::string Header;
284 raw_string_ostream Out(Header);
285 printWithSpacePadding(Out, "//", 48);
286 printWithSpacePadding(Out, Size + Pad, 10);
287 Out << "`\n";
288 Out.flush();
289 return {{}, std::move(Header), Names, Pad ? "\n" : ""};
290}
291
292static sys::TimePoint<std::chrono::seconds> now(bool Deterministic) {
293 using namespace std::chrono;
294
295 if (!Deterministic)
296 return time_point_cast<seconds>(system_clock::now());
297 return sys::TimePoint<seconds>();
298}
299
300static bool isArchiveSymbol(const object::BasicSymbolRef &S) {
301 uint32_t Symflags = S.getFlags();
302 if (Symflags & object::SymbolRef::SF_FormatSpecific)
303 return false;
304 if (!(Symflags & object::SymbolRef::SF_Global))
305 return false;
306 if (Symflags & object::SymbolRef::SF_Undefined)
307 return false;
308 return true;
309}
310
311static void printNBits(raw_ostream &Out, object::Archive::Kind Kind,
312 uint64_t Val) {
313 if (is64BitKind(Kind))
314 print<uint64_t>(Out, Kind, Val);
315 else
316 print<uint32_t>(Out, Kind, Val);
317}
318
319static void writeSymbolTable(raw_ostream &Out, object::Archive::Kind Kind,
320 bool Deterministic, ArrayRef<MemberData> Members,
321 StringRef StringTable) {
322 // We don't write a symbol table on an archive with no members -- except on
323 // Darwin, where the linker will abort unless the archive has a symbol table.
324 if (StringTable.empty() && !isDarwin(Kind))
325 return;
326
327 unsigned NumSyms = 0;
328 for (const MemberData &M : Members)
329 NumSyms += M.Symbols.size();
330
331 unsigned Size = 0;
332 unsigned OffsetSize = is64BitKind(Kind) ? sizeof(uint64_t) : sizeof(uint32_t);
333
334 Size += OffsetSize; // Number of entries
335 if (isBSDLike(Kind))
336 Size += NumSyms * OffsetSize * 2; // Table
337 else
338 Size += NumSyms * OffsetSize; // Table
339 if (isBSDLike(Kind))
340 Size += OffsetSize; // byte count
341 Size += StringTable.size();
342 // ld64 expects the members to be 8-byte aligned for 64-bit content and at
343 // least 4-byte aligned for 32-bit content. Opt for the larger encoding
344 // uniformly.
345 // We do this for all bsd formats because it simplifies aligning members.
346 unsigned Alignment = isBSDLike(Kind) ? 8 : 2;
347 unsigned Pad = OffsetToAlignment(Size, Alignment);
348 Size += Pad;
349
350 if (isBSDLike(Kind)) {
351 const char *Name = is64BitKind(Kind) ? "__.SYMDEF_64" : "__.SYMDEF";
352 printBSDMemberHeader(Out, Out.tell(), Name, now(Deterministic), 0, 0, 0,
353 Size);
354 } else {
355 const char *Name = is64BitKind(Kind) ? "/SYM64" : "";
356 printGNUSmallMemberHeader(Out, Name, now(Deterministic), 0, 0, 0, Size);
357 }
358
359 uint64_t Pos = Out.tell() + Size;
360
361 if (isBSDLike(Kind))
362 printNBits(Out, Kind, NumSyms * 2 * OffsetSize);
363 else
364 printNBits(Out, Kind, NumSyms);
365
366 for (const MemberData &M : Members) {
367 for (unsigned StringOffset : M.Symbols) {
368 if (isBSDLike(Kind))
369 printNBits(Out, Kind, StringOffset);
370 printNBits(Out, Kind, Pos); // member offset
371 }
372 Pos += M.Header.size() + M.Data.size() + M.Padding.size();
373 }
374
375 if (isBSDLike(Kind))
376 // byte count of the string table
377 printNBits(Out, Kind, StringTable.size());
378 Out << StringTable;
379
380 while (Pad--)
381 Out.write(uint8_t(0));
382}
383
384static Expected<std::vector<unsigned>>
385getSymbols(MemoryBufferRef Buf, raw_ostream &SymNames, bool &HasObject) {
386 std::vector<unsigned> Ret;
387
388 // In the scenario when LLVMContext is populated SymbolicFile will contain a
389 // reference to it, thus SymbolicFile should be destroyed first.
390 LLVMContext Context;
391 std::unique_ptr<object::SymbolicFile> Obj;
392 if (identify_magic(Buf.getBuffer()) == file_magic::bitcode) {
9
Assuming the condition is true
10
Taking true branch
393 auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
394 Buf, file_magic::bitcode, &Context);
395 if (!ObjOrErr) {
11
Taking true branch
396 // FIXME: check only for "not an object file" errors.
397 consumeError(ObjOrErr.takeError());
12
Calling 'consumeError'
398 return Ret;
399 }
400 Obj = std::move(*ObjOrErr);
401 } else {
402 auto ObjOrErr = object::SymbolicFile::createSymbolicFile(Buf);
403 if (!ObjOrErr) {
404 // FIXME: check only for "not an object file" errors.
405 consumeError(ObjOrErr.takeError());
406 return Ret;
407 }
408 Obj = std::move(*ObjOrErr);
409 }
410
411 HasObject = true;
412 for (const object::BasicSymbolRef &S : Obj->symbols()) {
413 if (!isArchiveSymbol(S))
414 continue;
415 Ret.push_back(SymNames.tell());
416 if (auto EC = S.printName(SymNames))
417 return errorCodeToError(EC);
418 SymNames << '\0';
419 }
420 return Ret;
421}
422
423static Expected<std::vector<MemberData>>
424computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
425 object::Archive::Kind Kind, bool Thin, StringRef ArcName,
426 bool Deterministic, ArrayRef<NewArchiveMember> NewMembers) {
427 static char PaddingData[8] = {'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n'};
428
429 // This ignores the symbol table, but we only need the value mod 8 and the
430 // symbol table is aligned to be a multiple of 8 bytes
431 uint64_t Pos = 0;
432
433 std::vector<MemberData> Ret;
434 bool HasObject = false;
435
436 // UniqueTimestamps is a special case to improve debugging on Darwin:
437 //
438 // The Darwin linker does not link debug info into the final
439 // binary. Instead, it emits entries of type N_OSO in in the output
440 // binary's symbol table, containing references to the linked-in
441 // object files. Using that reference, the debugger can read the
442 // debug data directly from the object files. Alternatively, an
443 // invocation of 'dsymutil' will link the debug data from the object
444 // files into a dSYM bundle, which can be loaded by the debugger,
445 // instead of the object files.
446 //
447 // For an object file, the N_OSO entries contain the absolute path
448 // path to the file, and the file's timestamp. For an object
449 // included in an archive, the path is formatted like
450 // "/absolute/path/to/archive.a(member.o)", and the timestamp is the
451 // archive member's timestamp, rather than the archive's timestamp.
452 //
453 // However, this doesn't always uniquely identify an object within
454 // an archive -- an archive file can have multiple entries with the
455 // same filename. (This will happen commonly if the original object
456 // files started in different directories.) The only way they get
457 // distinguished, then, is via the timestamp. But this process is
458 // unable to find the correct object file in the archive when there
459 // are two files of the same name and timestamp.
460 //
461 // Additionally, timestamp==0 is treated specially, and causes the
462 // timestamp to be ignored as a match criteria.
463 //
464 // That will "usually" work out okay when creating an archive not in
465 // deterministic timestamp mode, because the objects will probably
466 // have been created at different timestamps.
467 //
468 // To ameliorate this problem, in deterministic archive mode (which
469 // is the default), on Darwin we will emit a unique non-zero
470 // timestamp for each entry with a duplicated name. This is still
471 // deterministic: the only thing affecting that timestamp is the
472 // order of the files in the resultant archive.
473 //
474 // See also the functions that handle the lookup:
475 // in lldb: ObjectContainerBSDArchive::Archive::FindObject()
476 // in llvm/tools/dsymutil: BinaryHolder::GetArchiveMemberBuffers().
477 bool UniqueTimestamps = Deterministic && isDarwin(Kind);
2
Assuming 'Deterministic' is 0
478 std::map<StringRef, unsigned> FilenameCount;
479 if (UniqueTimestamps) {
3
Taking false branch
480 for (const NewArchiveMember &M : NewMembers)
481 FilenameCount[M.MemberName]++;
482 for (auto &Entry : FilenameCount)
483 Entry.second = Entry.second > 1 ? 1 : 0;
484 }
485
486 for (const NewArchiveMember &M : NewMembers) {
4
Assuming '__begin1' is not equal to '__end1'
487 std::string Header;
488 raw_string_ostream Out(Header);
489
490 MemoryBufferRef Buf = M.Buf->getMemBufferRef();
491 StringRef Data = Thin ? "" : Buf.getBuffer();
5
'?' condition is true
492
493 // ld64 expects the members to be 8-byte aligned for 64-bit content and at
494 // least 4-byte aligned for 32-bit content. Opt for the larger encoding
495 // uniformly. This matches the behaviour with cctools and ensures that ld64
496 // is happy with archives that we generate.
497 unsigned MemberPadding =
498 isDarwin(Kind) ? OffsetToAlignment(Data.size(), 8) : 0;
6
'?' condition is false
499 unsigned TailPadding = OffsetToAlignment(Data.size() + MemberPadding, 2);
500 StringRef Padding = StringRef(PaddingData, MemberPadding + TailPadding);
501
502 sys::TimePoint<std::chrono::seconds> ModTime;
503 if (UniqueTimestamps)
7
Taking false branch
504 // Increment timestamp for each file of a given name.
505 ModTime = sys::toTimePoint(FilenameCount[M.MemberName]++);
506 else
507 ModTime = M.ModTime;
508 printMemberHeader(Out, Pos, StringTable, Kind, Thin, ArcName, M, ModTime,
509 Buf.getBufferSize() + MemberPadding);
510 Out.flush();
511
512 Expected<std::vector<unsigned>> Symbols =
513 getSymbols(Buf, SymNames, HasObject);
8
Calling 'getSymbols'
514 if (auto E = Symbols.takeError())
515 return std::move(E);
516
517 Pos += Header.size() + Data.size() + Padding.size();
518 Ret.push_back({std::move(*Symbols), std::move(Header), Data, Padding});
519 }
520 // If there are no symbols, emit an empty symbol table, to satisfy Solaris
521 // tools, older versions of which expect a symbol table in a non-empty
522 // archive, regardless of whether there are any symbols in it.
523 if (HasObject && SymNames.tell() == 0)
524 SymNames << '\0' << '\0' << '\0';
525 return Ret;
526}
527
528Error llvm::writeArchive(StringRef ArcName,
529 ArrayRef<NewArchiveMember> NewMembers,
530 bool WriteSymtab, object::Archive::Kind Kind,
531 bool Deterministic, bool Thin,
532 std::unique_ptr<MemoryBuffer> OldArchiveBuf) {
533 assert((!Thin || !isBSDLike(Kind)) && "Only the gnu format has a thin mode")(((!Thin || !isBSDLike(Kind)) && "Only the gnu format has a thin mode"
) ? static_cast<void> (0) : __assert_fail ("(!Thin || !isBSDLike(Kind)) && \"Only the gnu format has a thin mode\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Object/ArchiveWriter.cpp"
, 533, __PRETTY_FUNCTION__))
;
534
535 SmallString<0> SymNamesBuf;
536 raw_svector_ostream SymNames(SymNamesBuf);
537 SmallString<0> StringTableBuf;
538 raw_svector_ostream StringTable(StringTableBuf);
539
540 Expected<std::vector<MemberData>> DataOrErr = computeMemberData(
1
Calling 'computeMemberData'
541 StringTable, SymNames, Kind, Thin, ArcName, Deterministic, NewMembers);
542 if (Error E = DataOrErr.takeError())
543 return E;
544 std::vector<MemberData> &Data = *DataOrErr;
545
546 if (!StringTableBuf.empty())
547 Data.insert(Data.begin(), computeStringTable(StringTableBuf));
548
549 // We would like to detect if we need to switch to a 64-bit symbol table.
550 if (WriteSymtab) {
551 uint64_t MaxOffset = 0;
552 uint64_t LastOffset = MaxOffset;
553 for (const auto &M : Data) {
554 // Record the start of the member's offset
555 LastOffset = MaxOffset;
556 // Account for the size of each part associated with the member.
557 MaxOffset += M.Header.size() + M.Data.size() + M.Padding.size();
558 // We assume 32-bit symbols to see if 32-bit symbols are possible or not.
559 MaxOffset += M.Symbols.size() * 4;
560 }
561
562 // The SYM64 format is used when an archive's member offsets are larger than
563 // 32-bits can hold. The need for this shift in format is detected by
564 // writeArchive. To test this we need to generate a file with a member that
565 // has an offset larger than 32-bits but this demands a very slow test. To
566 // speed the test up we use this environment variable to pretend like the
567 // cutoff happens before 32-bits and instead happens at some much smaller
568 // value.
569 const char *Sym64Env = std::getenv("SYM64_THRESHOLD");
570 int Sym64Threshold = 32;
571 if (Sym64Env)
572 StringRef(Sym64Env).getAsInteger(10, Sym64Threshold);
573
574 // If LastOffset isn't going to fit in a 32-bit varible we need to switch
575 // to 64-bit. Note that the file can be larger than 4GB as long as the last
576 // member starts before the 4GB offset.
577 if (LastOffset >= (1ULL << Sym64Threshold)) {
578 if (Kind == object::Archive::K_DARWIN)
579 Kind = object::Archive::K_DARWIN64;
580 else
581 Kind = object::Archive::K_GNU64;
582 }
583 }
584
585 Expected<sys::fs::TempFile> Temp =
586 sys::fs::TempFile::create(ArcName + ".temp-archive-%%%%%%%.a");
587 if (!Temp)
588 return Temp.takeError();
589
590 raw_fd_ostream Out(Temp->FD, false);
591 if (Thin)
592 Out << "!<thin>\n";
593 else
594 Out << "!<arch>\n";
595
596 if (WriteSymtab)
597 writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf);
598
599 for (const MemberData &M : Data)
600 Out << M.Header << M.Data << M.Padding;
601
602 Out.flush();
603
604 // At this point, we no longer need whatever backing memory
605 // was used to generate the NewMembers. On Windows, this buffer
606 // could be a mapped view of the file we want to replace (if
607 // we're updating an existing archive, say). In that case, the
608 // rename would still succeed, but it would leave behind a
609 // temporary file (actually the original file renamed) because
610 // a file cannot be deleted while there's a handle open on it,
611 // only renamed. So by freeing this buffer, this ensures that
612 // the last open handle on the destination file, if any, is
613 // closed before we attempt to rename.
614 OldArchiveBuf.reset();
615
616 return Temp->keep(ArcName);
617}

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class ErrorSuccess;
46
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51 virtual ~ErrorInfoBase() = default;
52
53 /// Print an error message to an output stream.
54 virtual void log(raw_ostream &OS) const = 0;
55
56 /// Return the error message as a string.
57 virtual std::string message() const {
58 std::string Msg;
59 raw_string_ostream OS(Msg);
60 log(OS);
61 return OS.str();
62 }
63
64 /// Convert this error to a std::error_code.
65 ///
66 /// This is a temporary crutch to enable interaction with code still
67 /// using std::error_code. It will be removed in the future.
68 virtual std::error_code convertToErrorCode() const = 0;
69
70 // Returns the class ID for this type.
71 static const void *classID() { return &ID; }
72
73 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74 virtual const void *dynamicClassID() const = 0;
75
76 // Check whether this instance is a subclass of the class identified by
77 // ClassID.
78 virtual bool isA(const void *const ClassID) const {
79 return ClassID == classID();
80 }
81
82 // Check whether this instance is a subclass of ErrorInfoT.
83 template <typename ErrorInfoT> bool isA() const {
84 return isA(ErrorInfoT::classID());
85 }
86
87private:
88 virtual void anchor();
89
90 static char ID;
91};
92
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109/// @code{.cpp}
110/// Error foo(<...>);
111///
112/// if (auto E = foo(<...>))
113/// return E; // <- Return E if it is in the error state.
114/// // We have verified that E was in the success state. It can now be safely
115/// // destroyed.
116/// @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125/// @code{.cpp}
126/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127/// // Custom error info.
128/// };
129///
130/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133/// auto NewE =
134/// handleErrors(E,
135/// [](const MyErrorInfo &M) {
136/// // Deal with the error.
137/// },
138/// [](std::unique_ptr<OtherError> M) -> Error {
139/// if (canHandle(*M)) {
140/// // handle error.
141/// return Error::success();
142/// }
143/// // Couldn't handle this error instance. Pass it up the stack.
144/// return Error(std::move(M));
145/// );
146/// // Note - we must check or return NewE in case any of the handlers
147/// // returned a new error.
148/// @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160 // pointers out of this class to add to the error list.
161 friend class ErrorList;
162 friend class FileError;
163
164 // handleErrors needs to be able to set the Checked flag.
165 template <typename... HandlerTs>
166 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167
168 // Expected<T> needs to be able to steal the payload when constructed from an
169 // error.
170 template <typename T> friend class Expected;
171
172 // wrap needs to be able to steal the payload.
173 friend LLVMErrorRef wrap(Error);
174
175protected:
176 /// Create a success value. Prefer using 'Error::success()' for readability
177 Error() {
178 setPtr(nullptr);
179 setChecked(false);
180 }
181
182public:
183 /// Create a success value.
184 static ErrorSuccess success();
185
186 // Errors are not copy-constructable.
187 Error(const Error &Other) = delete;
188
189 /// Move-construct an error value. The newly constructed error is considered
190 /// unchecked, even if the source error had been checked. The original error
191 /// becomes a checked Success value, regardless of its original state.
192 Error(Error &&Other) {
193 setChecked(true);
194 *this = std::move(Other);
195 }
196
197 /// Create an error value. Prefer using the 'make_error' function, but
198 /// this constructor can be useful when "re-throwing" errors from handlers.
199 Error(std::unique_ptr<ErrorInfoBase> Payload) {
200 setPtr(Payload.release());
201 setChecked(false);
27
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202 }
203
204 // Errors are not copy-assignable.
205 Error &operator=(const Error &Other) = delete;
206
207 /// Move-assign an error value. The current error must represent success, you
208 /// you cannot overwrite an unhandled error. The current error is then
209 /// considered unchecked. The source error becomes a checked success value,
210 /// regardless of its original state.
211 Error &operator=(Error &&Other) {
212 // Don't allow overwriting of unchecked values.
213 assertIsChecked();
214 setPtr(Other.getPtr());
215
216 // This Error is unchecked, even if the source error was checked.
217 setChecked(false);
218
219 // Null out Other's payload and set its checked bit.
220 Other.setPtr(nullptr);
221 Other.setChecked(true);
222
223 return *this;
224 }
225
226 /// Destroy a Error. Fails with a call to abort() if the error is
227 /// unchecked.
228 ~Error() {
229 assertIsChecked();
230 delete getPtr();
231 }
232
233 /// Bool conversion. Returns true if this Error is in a failure state,
234 /// and false if it is in an accept state. If the error is in a Success state
235 /// it will be considered checked.
236 explicit operator bool() {
237 setChecked(getPtr() == nullptr);
238 return getPtr() != nullptr;
239 }
240
241 /// Check whether one error is a subclass of another.
242 template <typename ErrT> bool isA() const {
243 return getPtr() && getPtr()->isA(ErrT::classID());
244 }
245
246 /// Returns the dynamic class id of this error, or null if this is a success
247 /// value.
248 const void* dynamicClassID() const {
249 if (!getPtr())
250 return nullptr;
251 return getPtr()->dynamicClassID();
252 }
253
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256 // assertIsChecked() happens very frequently, but under normal circumstances
257 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
258 // of debug prints can cause the function to be too large for inlining. So
259 // it's important that we define this function out of line so that it can't be
260 // inlined.
261 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262 void fatalUncheckedError() const;
263#endif
264
265 void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268 fatalUncheckedError();
269#endif
270 }
271
272 ErrorInfoBase *getPtr() const {
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
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 Payload = reinterpret_cast<ErrorInfoBase*>(
299 (reinterpret_cast<uintptr_t>(Payload) &
300 ~static_cast<uintptr_t>(0x1)) |
301 (V ? 0 : 1));
302 }
303
304 std::unique_ptr<ErrorInfoBase> takePayload() {
305 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306 setPtr(nullptr);
307 setChecked(true);
308 return Tmp;
309 }
310
311 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312 if (auto P = E.getPtr())
313 P->log(OS);
314 else
315 OS << "success";
316 return OS;
317 }
318
319 ErrorInfoBase *Payload = nullptr;
320};
321
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
333}
334
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339/// ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347 using ParentErrT::ParentErrT; // inherit constructors
348
349 static const void *classID() { return &ThisErrT::ID; }
350
351 const void *dynamicClassID() const override { return &ThisErrT::ID; }
352
353 bool isA(const void *const ClassID) const override {
354 return ClassID == classID() || ParentErrT::isA(ClassID);
355 }
356};
357
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361 // handleErrors needs to be able to iterate the payload list of an
362 // ErrorList.
363 template <typename... HandlerTs>
364 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365
366 // joinErrors is implemented in terms of join.
367 friend Error joinErrors(Error, Error);
368
369public:
370 void log(raw_ostream &OS) const override {
371 OS << "Multiple errors:\n";
372 for (auto &ErrPayload : Payloads) {
373 ErrPayload->log(OS);
374 OS << "\n";
375 }
376 }
377
378 std::error_code convertToErrorCode() const override;
379
380 // Used by ErrorInfo::classID.
381 static char ID;
382
383private:
384 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385 std::unique_ptr<ErrorInfoBase> Payload2) {
386 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
;
388 Payloads.push_back(std::move(Payload1));
389 Payloads.push_back(std::move(Payload2));
390 }
391
392 static Error join(Error E1, Error E2) {
393 if (!E1)
19
Taking false branch
394 return E2;
395 if (!E2)
20
Taking false branch
396 return E1;
397 if (E1.isA<ErrorList>()) {
21
Assuming the condition is false
22
Taking false branch
398 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399 if (E2.isA<ErrorList>()) {
400 auto E2Payload = E2.takePayload();
401 auto &E2List = static_cast<ErrorList &>(*E2Payload);
402 for (auto &Payload : E2List.Payloads)
403 E1List.Payloads.push_back(std::move(Payload));
404 } else
405 E1List.Payloads.push_back(E2.takePayload());
406
407 return E1;
408 }
409 if (E2.isA<ErrorList>()) {
23
Assuming the condition is false
24
Taking false branch
410 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412 return E2;
413 }
414 return Error(std::unique_ptr<ErrorList>(
26
Calling constructor for 'Error'
415 new ErrorList(E1.takePayload(), E2.takePayload())));
25
Memory is allocated
416 }
417
418 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425 return ErrorList::join(std::move(E1), std::move(E2));
426}
427
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435 template <class T1> friend class ExpectedAsOutParameter;
436 template <class OtherT> friend class Expected;
437
438 static const bool isRef = std::is_reference<T>::value;
439
440 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441
442 using error_type = std::unique_ptr<ErrorInfoBase>;
443
444public:
445 using storage_type = typename std::conditional<isRef, wrap, T>::type;
446 using value_type = T;
447
448private:
449 using reference = typename std::remove_reference<T>::type &;
450 using const_reference = const typename std::remove_reference<T>::type &;
451 using pointer = typename std::remove_reference<T>::type *;
452 using const_pointer = const typename std::remove_reference<T>::type *;
453
454public:
455 /// Create an Expected<T> error value from the given Error.
456 Expected(Error Err)
457 : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459 // Expected is unchecked upon construction in Debug builds.
460 , Unchecked(true)
461#endif
462 {
463 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__))
;
464 new (getErrorStorage()) error_type(Err.takePayload());
465 }
466
467 /// Forbid to convert from Error::success() implicitly, this avoids having
468 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469 /// but triggers the assertion above.
470 Expected(ErrorSuccess) = delete;
471
472 /// Create an Expected<T> success value from the given OtherT value, which
473 /// must be convertible to T.
474 template <typename OtherT>
475 Expected(OtherT &&Val,
476 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477 * = nullptr)
478 : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480 // Expected is unchecked upon construction in Debug builds.
481 , Unchecked(true)
482#endif
483 {
484 new (getStorage()) storage_type(std::forward<OtherT>(Val));
485 }
486
487 /// Move construct an Expected<T> value.
488 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489
490 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491 /// must be convertible to T.
492 template <class OtherT>
493 Expected(Expected<OtherT> &&Other,
494 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495 * = nullptr) {
496 moveConstruct(std::move(Other));
497 }
498
499 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500 /// isn't convertible to T.
501 template <class OtherT>
502 explicit Expected(
503 Expected<OtherT> &&Other,
504 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505 nullptr) {
506 moveConstruct(std::move(Other));
507 }
508
509 /// Move-assign from another Expected<T>.
510 Expected &operator=(Expected &&Other) {
511 moveAssign(std::move(Other));
512 return *this;
513 }
514
515 /// Destroy an Expected<T>.
516 ~Expected() {
517 assertIsChecked();
518 if (!HasError)
519 getStorage()->~storage_type();
520 else
521 getErrorStorage()->~error_type();
522 }
523
524 /// Return false if there is an error.
525 explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527 Unchecked = HasError;
528#endif
529 return !HasError;
530 }
531
532 /// Returns a reference to the stored T value.
533 reference get() {
534 assertIsChecked();
535 return *getStorage();
536 }
537
538 /// Returns a const reference to the stored T value.
539 const_reference get() const {
540 assertIsChecked();
541 return const_cast<Expected<T> *>(this)->get();
542 }
543
544 /// Check that this Expected<T> is an error of type ErrT.
545 template <typename ErrT> bool errorIsA() const {
546 return HasError && (*getErrorStorage())->template isA<ErrT>();
547 }
548
549 /// Take ownership of the stored error.
550 /// After calling this the Expected<T> is in an indeterminate state that can
551 /// only be safely destructed. No further calls (beside the destructor) should
552 /// be made on the Expected<T> vaule.
553 Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555 Unchecked = false;
556#endif
557 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558 }
559
560 /// Returns a pointer to the stored T value.
561 pointer operator->() {
562 assertIsChecked();
563 return toPointer(getStorage());
564 }
565
566 /// Returns a const pointer to the stored T value.
567 const_pointer operator->() const {
568 assertIsChecked();
569 return toPointer(getStorage());
570 }
571
572 /// Returns a reference to the stored T value.
573 reference operator*() {
574 assertIsChecked();
575 return *getStorage();
576 }
577
578 /// Returns a const reference to the stored T value.
579 const_reference operator*() const {
580 assertIsChecked();
581 return *getStorage();
582 }
583
584private:
585 template <class T1>
586 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587 return &a == &b;
588 }
589
590 template <class T1, class T2>
591 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592 return false;
593 }
594
595 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596 HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598 Unchecked = true;
599 Other.Unchecked = false;
600#endif
601
602 if (!HasError)
603 new (getStorage()) storage_type(std::move(*Other.getStorage()));
604 else
605 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606 }
607
608 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609 assertIsChecked();
610
611 if (compareThisIfSameType(*this, Other))
612 return;
613
614 this->~Expected();
615 new (this) Expected(std::move(Other));
616 }
617
618 pointer toPointer(pointer Val) { return Val; }
619
620 const_pointer toPointer(const_pointer Val) const { return Val; }
621
622 pointer toPointer(wrap *Val) { return &Val->get(); }
623
624 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625
626 storage_type *getStorage() {
627 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__))
;
628 return reinterpret_cast<storage_type *>(TStorage.buffer);
629 }
630
631 const storage_type *getStorage() const {
632 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__))
;
633 return reinterpret_cast<const storage_type *>(TStorage.buffer);
634 }
635
636 error_type *getErrorStorage() {
637 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__))
;
638 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639 }
640
641 const error_type *getErrorStorage() const {
642 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__))
;
643 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644 }
645
646 // Used by ExpectedAsOutParameter to reset the checked flag.
647 void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649 Unchecked = true;
650#endif
651 }
652
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656 void fatalUncheckedExpected() const {
657 dbgs() << "Expected<T> must be checked before access or destruction.\n";
658 if (HasError) {
659 dbgs() << "Unchecked Expected<T> contained error:\n";
660 (*getErrorStorage())->log(dbgs());
661 } else
662 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663 "values in success mode must still be checked prior to being "
664 "destroyed).\n";
665 abort();
666 }
667#endif
668
669 void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672 fatalUncheckedExpected();
673#endif
674 }
675
676 union {
677 AlignedCharArrayUnion<storage_type> TStorage;
678 AlignedCharArrayUnion<error_type> ErrorStorage;
679 };
680 bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682 bool Unchecked : 1;
683#endif
684};
685
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689 bool gen_crash_diag = true);
690
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696/// @code{.cpp}
697/// // foo only attempts the fallible operation if DoFallibleOperation is
698/// // true. If DoFallibleOperation is false then foo always returns
699/// // Error::success().
700/// Error foo(bool DoFallibleOperation);
701///
702/// cantFail(foo(false));
703/// @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705 if (Err) {
706 if (!Msg)
707 Msg = "Failure value returned from cantFail wrapped call";
708 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708)
;
709 }
710}
711
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718/// @code{.cpp}
719/// // foo only attempts the fallible operation if DoFallibleOperation is
720/// // true. If DoFallibleOperation is false then foo always returns an int.
721/// Expected<int> foo(bool DoFallibleOperation);
722///
723/// int X = cantFail(foo(false));
724/// @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727 if (ValOrErr)
728 return std::move(*ValOrErr);
729 else {
730 if (!Msg)
731 Msg = "Failure value returned from cantFail wrapped call";
732 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732)
;
733 }
734}
735
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742/// @code{.cpp}
743/// // foo only attempts the fallible operation if DoFallibleOperation is
744/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
745/// Expected<Bar&> foo(bool DoFallibleOperation);
746///
747/// Bar &X = cantFail(foo(false));
748/// @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751 if (ValOrErr)
752 return *ValOrErr;
753 else {
754 if (!Msg)
755 Msg = "Failure value returned from cantFail wrapped call";
756 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756)
;
757 }
758}
759
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764 : public ErrorHandlerTraits<decltype(
765 &std::remove_reference<HandlerT>::type::operator())> {};
766
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770 static bool appliesTo(const ErrorInfoBase &E) {
771 return E.template isA<ErrT>();
772 }
773
774 template <typename HandlerT>
775 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__))
;
777 return H(static_cast<ErrT &>(*E));
778 }
779};
780
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__))
;
791 H(static_cast<ErrT &>(*E));
792 return Error::success();
793 }
794};
795
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__))
;
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 return H(std::move(SubE));
809 }
810};
811
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816 static bool appliesTo(const ErrorInfoBase &E) {
817 return E.template isA<ErrT>();
818 }
819
820 template <typename HandlerT>
821 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__))
;
823 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824 H(std::move(SubE));
825 return Error::success();
826 }
827};
828
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862 return Error(std::move(Payload));
863}
864
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867 HandlerT &&Handler, HandlerTs &&... Handlers) {
868 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870 std::move(Payload));
871 return handleErrorImpl(std::move(Payload),
872 std::forward<HandlerTs>(Handlers)...);
873}
874
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883 if (!E)
15
Taking false branch
884 return Error::success();
885
886 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887
888 if (Payload->isA<ErrorList>()) {
16
Assuming the condition is true
17
Taking true branch
889 ErrorList &List = static_cast<ErrorList &>(*Payload);
890 Error R;
891 for (auto &P : List.Payloads)
892 R = ErrorList::join(
18
Calling 'ErrorList::join'
893 std::move(R),
894 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895 return R;
896 }
897
898 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
14
Calling 'handleErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:979:35)>'
907}
908
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912 cantFail(std::move(E));
913}
914
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925/// @code{.cpp}
926/// enum FooStrategy { Aggressive, Conservative };
927/// Expected<Foo> foo(FooStrategy S);
928///
929/// auto ResultOrErr =
930/// handleExpected(
931/// foo(Aggressive),
932/// []() { return foo(Conservative); },
933/// [](AggressiveStrategyError&) {
934/// // Implicitly conusme this - we'll recover by using a conservative
935/// // strategy.
936/// });
937///
938/// @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941 HandlerTs &&... Handlers) {
942 if (ValOrErr)
943 return ValOrErr;
944
945 if (auto Err = handleErrors(ValOrErr.takeError(),
946 std::forward<HandlerTs>(Handlers)...))
947 return std::move(Err);
948
949 return RecoveryPath();
950}
951
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964 SmallVector<std::string, 2> Errors;
965 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
966 Errors.push_back(EI.message());
967 });
968 return join(Errors.begin(), Errors.end(), "\n");
969}
970
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
13
Calling 'handleAllErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:979:35)>'
980}
981
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state. Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988 bool IsError = static_cast<bool>(Err);
989 if (IsError)
990 consumeError(std::move(Err));
991 return IsError;
992}
993
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004/// @code{.cpp}
1005/// Result foo(Error &Err) {
1006/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007/// // <body of foo>
1008/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009/// }
1010/// @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020 ErrorAsOutParameter(Error *Err) : Err(Err) {
1021 // Raise the checked bit if Err is success.
1022 if (Err)
1023 (void)!!*Err;
1024 }
1025
1026 ~ErrorAsOutParameter() {
1027 // Clear the checked bit.
1028 if (Err && !*Err)
1029 *Err = Error::success();
1030 }
1031
1032private:
1033 Error *Err;
1034};
1035
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043 : ValOrErr(ValOrErr) {
1044 if (ValOrErr)
1045 (void)!!*ValOrErr;
1046 }
1047
1048 ~ExpectedAsOutParameter() {
1049 if (ValOrErr)
1050 ValOrErr->setUnchecked();
1051 }
1052
1053private:
1054 Expected<T> *ValOrErr;
1055};
1056
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063 friend Error errorCodeToError(std::error_code);
1064
1065public:
1066 void setErrorCode(std::error_code EC) { this->EC = EC; }
1067 std::error_code convertToErrorCode() const override { return EC; }
1068 void log(raw_ostream &OS) const override { OS << EC.message(); }
1069
1070 // Used by ErrorInfo::classID.
1071 static char ID;
1072
1073protected:
1074 ECError() = default;
1075 ECError(std::error_code EC) : EC(EC) {}
1076
1077 std::error_code EC;
1078};
1079
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099 if (auto EC = EO.getError())
1100 return errorCodeToError(EC);
1101 return std::move(*EO);
1102}
1103
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106 if (auto Err = E.takeError())
1107 return errorToErrorCode(std::move(Err));
1108 return std::move(*E);
1109}
1110
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120/// 1. the error_code message (ECError behavior)
1121/// 2. a string
1122/// 3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128/// @code{.cpp}
1129/// Expected<int> foo() {
1130/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131/// "Additional information");
1132/// }
1133/// @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137 static char ID;
1138
1139 // Prints EC + S and converts to EC
1140 StringError(std::error_code EC, const Twine &S = Twine());
1141
1142 // Prints S and converts to EC
1143 StringError(const Twine &S, std::error_code EC);
1144
1145 void log(raw_ostream &OS) const override;
1146 std::error_code convertToErrorCode() const override;
1147
1148 const std::string &getMessage() const { return Msg; }
1149
1150private:
1151 std::string Msg;
1152 std::error_code EC;
1153 const bool PrintMsgOnly = false;
1154};
1155
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159 const Ts &... Vals) {
1160 std::string Buffer;
1161 raw_string_ostream Stream(Buffer);
1162 Stream << format(Fmt, Vals...);
1163 return make_error<StringError>(Stream.str(), EC);
1164}
1165
1166Error createStringError(std::error_code EC, char const *Msg);
1167
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173
1174 friend Error createFileError(std::string, Error);
1175
1176public:
1177 void log(raw_ostream &OS) const override {
1178 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__))
;
1179 OS << "'" << FileName << "': ";
1180 Err->log(OS);
1181 }
1182
1183 Error takeError() { return Error(std::move(Err)); }
1184
1185 std::error_code convertToErrorCode() const override;
1186
1187 // Used by ErrorInfo::classID.
1188 static char ID;
1189
1190private:
1191 FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__))
;
1193 assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194 "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
;
1195 FileName = F;
1196 Err = std::move(E);
1197 }
1198
1199 static Error build(std::string F, Error E) {
1200 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201 }
1202
1203 std::string FileName;
1204 std::unique_ptr<ErrorInfoBase> Err;
1205};
1206
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210 return FileError::build(F, std::move(E));
1211}
1212
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221 /// Create an error on exit helper.
1222 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223 : Banner(std::move(Banner)),
1224 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225
1226 /// Set the banner string for any errors caught by operator().
1227 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228
1229 /// Set the exit-code mapper function.
1230 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231 this->GetExitCode = std::move(GetExitCode);
1232 }
1233
1234 /// Check Err. If it's in a failure state log the error(s) and exit.
1235 void operator()(Error Err) const { checkError(std::move(Err)); }
1236
1237 /// Check E. If it's in a success state then return the contained value. If
1238 /// it's in a failure state log the error(s) and exit.
1239 template <typename T> T operator()(Expected<T> &&E) const {
1240 checkError(E.takeError());
1241 return std::move(*E);
1242 }
1243
1244 /// Check E. If it's in a success state then return the contained reference. If
1245 /// it's in a failure state log the error(s) and exit.
1246 template <typename T> T& operator()(Expected<T&> &&E) const {
1247 checkError(E.takeError());
1248 return *E;
1249 }
1250
1251private:
1252 void checkError(Error Err) const {
1253 if (Err) {
1254 int ExitCode = GetExitCode(Err);
1255 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256 exit(ExitCode);
1257 }
1258 }
1259
1260 std::string Banner;
1261 std::function<int(const Error &)> GetExitCode;
1262};
1263
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271 return Error(std::unique_ptr<ErrorInfoBase>(
1272 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274
1275} // end namespace llvm
1276
1277#endif // LLVM_SUPPORT_ERROR_H