1 //===- ArchiveWriter.cpp - ar File Format implementation --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the writeArchive function.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Object/ArchiveWriter.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/IR/LLVMContext.h"
18 #include "llvm/Object/Archive.h"
19 #include "llvm/Object/ObjectFile.h"
20 #include "llvm/Object/SymbolicFile.h"
21 #include "llvm/Support/EndianStream.h"
22 #include "llvm/Support/Errc.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/Format.h"
25 #include "llvm/Support/Path.h"
26 #include "llvm/Support/ToolOutputFile.h"
27 #include "llvm/Support/raw_ostream.h"
29 #if !defined(_MSC_VER) && !defined(__MINGW32__)
37 NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
38 : Buf(MemoryBuffer::getMemBuffer(BufRef, false)) {}
40 Expected<NewArchiveMember>
41 NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
43 Expected<llvm::MemoryBufferRef> BufOrErr = OldMember.getMemoryBufferRef();
45 return BufOrErr.takeError();
48 assert(M.IsNew == false);
49 M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
51 auto ModTimeOrErr = OldMember.getLastModified();
53 return ModTimeOrErr.takeError();
54 M.ModTime = ModTimeOrErr.get();
55 Expected<unsigned> UIDOrErr = OldMember.getUID();
57 return UIDOrErr.takeError();
58 M.UID = UIDOrErr.get();
59 Expected<unsigned> GIDOrErr = OldMember.getGID();
61 return GIDOrErr.takeError();
62 M.GID = GIDOrErr.get();
63 Expected<sys::fs::perms> AccessModeOrErr = OldMember.getAccessMode();
65 return AccessModeOrErr.takeError();
66 M.Perms = AccessModeOrErr.get();
71 Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
73 sys::fs::file_status Status;
75 if (auto EC = sys::fs::openFileForRead(FileName, FD))
76 return errorCodeToError(EC);
79 if (auto EC = sys::fs::status(FD, Status))
80 return errorCodeToError(EC);
82 // Opening a directory doesn't make sense. Let it fail.
83 // Linux cannot open directories with open(2), although
84 // cygwin and *bsd can.
85 if (Status.type() == sys::fs::file_type::directory_file)
86 return errorCodeToError(make_error_code(errc::is_a_directory));
88 ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
89 MemoryBuffer::getOpenFile(FD, FileName, Status.getSize(), false);
90 if (!MemberBufferOrErr)
91 return errorCodeToError(MemberBufferOrErr.getError());
94 return errorCodeToError(std::error_code(errno, std::generic_category()));
98 M.Buf = std::move(*MemberBufferOrErr);
100 M.ModTime = std::chrono::time_point_cast<std::chrono::seconds>(
101 Status.getLastModificationTime());
102 M.UID = Status.getUser();
103 M.GID = Status.getGroup();
104 M.Perms = Status.permissions();
109 template <typename T>
110 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
111 bool MayTruncate = false) {
112 uint64_t OldPos = OS.tell();
114 unsigned SizeSoFar = OS.tell() - OldPos;
115 if (Size > SizeSoFar) {
116 OS.indent(Size - SizeSoFar);
117 } else if (Size < SizeSoFar) {
118 assert(MayTruncate && "Data doesn't fit in Size");
119 // Some of the data this is used for (like UID) can be larger than the
120 // space available in the archive format. Truncate in that case.
121 OS.seek(OldPos + Size);
125 static void print32(raw_ostream &Out, object::Archive::Kind Kind,
127 if (Kind == object::Archive::K_GNU)
128 support::endian::Writer<support::big>(Out).write(Val);
130 support::endian::Writer<support::little>(Out).write(Val);
133 static void printRestOfMemberHeader(
134 raw_fd_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
135 unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
136 printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
137 printWithSpacePadding(Out, UID, 6, true);
138 printWithSpacePadding(Out, GID, 6, true);
139 printWithSpacePadding(Out, format("%o", Perms), 8);
140 printWithSpacePadding(Out, Size, 10);
145 printGNUSmallMemberHeader(raw_fd_ostream &Out, StringRef Name,
146 const sys::TimePoint<std::chrono::seconds> &ModTime,
147 unsigned UID, unsigned GID, unsigned Perms,
149 printWithSpacePadding(Out, Twine(Name) + "/", 16);
150 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
154 printBSDMemberHeader(raw_fd_ostream &Out, StringRef Name,
155 const sys::TimePoint<std::chrono::seconds> &ModTime,
156 unsigned UID, unsigned GID, unsigned Perms,
158 uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
159 // Pad so that even 64 bit object files are aligned.
160 unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
161 unsigned NameWithPadding = Name.size() + Pad;
162 printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
163 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
164 NameWithPadding + Size);
166 assert(PosAfterHeader == Out.tell());
168 Out.write(uint8_t(0));
171 static bool useStringTable(bool Thin, StringRef Name) {
172 return Thin || Name.size() >= 16;
176 printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind, bool Thin,
178 std::vector<unsigned>::iterator &StringMapIndexIter,
179 const sys::TimePoint<std::chrono::seconds> &ModTime,
180 unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
181 if (Kind == object::Archive::K_BSD)
182 return printBSDMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
183 if (!useStringTable(Thin, Name))
184 return printGNUSmallMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
186 printWithSpacePadding(Out, *StringMapIndexIter++, 15);
187 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
190 // Compute the relative path from From to To.
191 static std::string computeRelativePath(StringRef From, StringRef To) {
192 if (sys::path::is_absolute(From) || sys::path::is_absolute(To))
195 StringRef DirFrom = sys::path::parent_path(From);
196 auto FromI = sys::path::begin(DirFrom);
197 auto ToI = sys::path::begin(To);
198 while (*FromI == *ToI) {
203 SmallString<128> Relative;
204 for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
205 sys::path::append(Relative, "..");
207 for (auto ToE = sys::path::end(To); ToI != ToE; ++ToI)
208 sys::path::append(Relative, *ToI);
211 // Replace backslashes with slashes so that the path is portable between *nix
213 std::replace(Relative.begin(), Relative.end(), '\\', '/');
216 return Relative.str();
219 static void writeStringTable(raw_fd_ostream &Out, StringRef ArcName,
220 ArrayRef<NewArchiveMember> Members,
221 std::vector<unsigned> &StringMapIndexes,
223 unsigned StartOffset = 0;
224 for (const NewArchiveMember &M : Members) {
225 StringRef Path = M.Buf->getBufferIdentifier();
226 StringRef Name = sys::path::filename(Path);
227 if (!useStringTable(Thin, Name))
229 if (StartOffset == 0) {
230 printWithSpacePadding(Out, "//", 58);
232 StartOffset = Out.tell();
234 StringMapIndexes.push_back(Out.tell() - StartOffset);
238 Out << computeRelativePath(ArcName, Path);
240 Out << M.Buf->getBufferIdentifier();
246 if (StartOffset == 0)
250 int Pos = Out.tell();
251 Out.seek(StartOffset - 12);
252 printWithSpacePadding(Out, Pos - StartOffset, 10);
256 static sys::TimePoint<std::chrono::seconds> now(bool Deterministic) {
257 using namespace std::chrono;
260 return time_point_cast<seconds>(system_clock::now());
261 return sys::TimePoint<seconds>();
264 // Returns the offset of the first reference to a member offset.
265 static ErrorOr<unsigned>
266 writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
267 ArrayRef<NewArchiveMember> Members,
268 std::vector<unsigned> &MemberOffsetRefs, bool Deterministic) {
269 unsigned HeaderStartOffset = 0;
270 unsigned BodyStartOffset = 0;
271 SmallString<128> NameBuf;
272 raw_svector_ostream NameOS(NameBuf);
274 for (unsigned MemberNum = 0, N = Members.size(); MemberNum < N; ++MemberNum) {
275 MemoryBufferRef MemberBuffer = Members[MemberNum].Buf->getMemBufferRef();
276 Expected<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
277 object::SymbolicFile::createSymbolicFile(
278 MemberBuffer, sys::fs::file_magic::unknown, &Context);
280 // FIXME: check only for "not an object file" errors.
281 consumeError(ObjOrErr.takeError());
284 object::SymbolicFile &Obj = *ObjOrErr.get();
286 if (!HeaderStartOffset) {
287 HeaderStartOffset = Out.tell();
288 if (Kind == object::Archive::K_GNU)
289 printGNUSmallMemberHeader(Out, "", now(Deterministic), 0, 0, 0, 0);
291 printBSDMemberHeader(Out, "__.SYMDEF", now(Deterministic), 0, 0, 0, 0);
292 BodyStartOffset = Out.tell();
293 print32(Out, Kind, 0); // number of entries or bytes
296 for (const object::BasicSymbolRef &S : Obj.symbols()) {
297 uint32_t Symflags = S.getFlags();
298 if (Symflags & object::SymbolRef::SF_FormatSpecific)
300 if (!(Symflags & object::SymbolRef::SF_Global))
302 if (Symflags & object::SymbolRef::SF_Undefined)
305 unsigned NameOffset = NameOS.tell();
306 if (auto EC = S.printName(NameOS))
309 MemberOffsetRefs.push_back(MemberNum);
310 if (Kind == object::Archive::K_BSD)
311 print32(Out, Kind, NameOffset);
312 print32(Out, Kind, 0); // member offset
316 if (HeaderStartOffset == 0)
319 StringRef StringTable = NameOS.str();
320 if (Kind == object::Archive::K_BSD)
321 print32(Out, Kind, StringTable.size()); // byte count of the string table
324 // ld64 requires the next member header to start at an offset that is
326 unsigned Pad = OffsetToAlignment(Out.tell(), 4);
328 Out.write(uint8_t(0));
330 // Patch up the size of the symbol table now that we know how big it is.
331 unsigned Pos = Out.tell();
332 const unsigned MemberHeaderSize = 60;
333 Out.seek(HeaderStartOffset + 48); // offset of the size field.
334 printWithSpacePadding(Out, Pos - MemberHeaderSize - HeaderStartOffset, 10);
336 // Patch up the number of symbols.
337 Out.seek(BodyStartOffset);
338 unsigned NumSyms = MemberOffsetRefs.size();
339 if (Kind == object::Archive::K_GNU)
340 print32(Out, Kind, NumSyms);
342 print32(Out, Kind, NumSyms * 8);
345 return BodyStartOffset + 4;
348 std::pair<StringRef, std::error_code>
349 llvm::writeArchive(StringRef ArcName,
350 std::vector<NewArchiveMember> &NewMembers,
351 bool WriteSymtab, object::Archive::Kind Kind,
352 bool Deterministic, bool Thin,
353 std::unique_ptr<MemoryBuffer> OldArchiveBuf) {
354 assert((!Thin || Kind == object::Archive::K_GNU) &&
355 "Only the gnu format has a thin mode");
356 SmallString<128> TmpArchive;
358 if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
359 TmpArchiveFD, TmpArchive))
360 return std::make_pair(ArcName, EC);
362 tool_output_file Output(TmpArchive, TmpArchiveFD);
363 raw_fd_ostream &Out = Output.os();
369 std::vector<unsigned> MemberOffsetRefs;
371 std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
372 std::vector<MemoryBufferRef> Members;
373 std::vector<sys::fs::file_status> NewMemberStatus;
375 unsigned MemberReferenceOffset = 0;
377 ErrorOr<unsigned> MemberReferenceOffsetOrErr = writeSymbolTable(
378 Out, Kind, NewMembers, MemberOffsetRefs, Deterministic);
379 if (auto EC = MemberReferenceOffsetOrErr.getError())
380 return std::make_pair(ArcName, EC);
381 MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
384 std::vector<unsigned> StringMapIndexes;
385 if (Kind != object::Archive::K_BSD)
386 writeStringTable(Out, ArcName, NewMembers, StringMapIndexes, Thin);
388 std::vector<unsigned>::iterator StringMapIndexIter = StringMapIndexes.begin();
389 std::vector<unsigned> MemberOffset;
390 for (const NewArchiveMember &M : NewMembers) {
391 MemoryBufferRef File = M.Buf->getMemBufferRef();
393 unsigned Pos = Out.tell();
394 MemberOffset.push_back(Pos);
396 printMemberHeader(Out, Kind, Thin,
397 sys::path::filename(M.Buf->getBufferIdentifier()),
398 StringMapIndexIter, M.ModTime, M.UID, M.GID, M.Perms,
399 M.Buf->getBufferSize());
402 Out << File.getBuffer();
408 if (MemberReferenceOffset) {
409 Out.seek(MemberReferenceOffset);
410 for (unsigned MemberNum : MemberOffsetRefs) {
411 if (Kind == object::Archive::K_BSD)
412 Out.seek(Out.tell() + 4); // skip over the string offset
413 print32(Out, Kind, MemberOffset[MemberNum]);
420 // At this point, we no longer need whatever backing memory
421 // was used to generate the NewMembers. On Windows, this buffer
422 // could be a mapped view of the file we want to replace (if
423 // we're updating an existing archive, say). In that case, the
424 // rename would still succeed, but it would leave behind a
425 // temporary file (actually the original file renamed) because
426 // a file cannot be deleted while there's a handle open on it,
427 // only renamed. So by freeing this buffer, this ensures that
428 // the last open handle on the destination file, if any, is
429 // closed before we attempt to rename.
430 OldArchiveBuf.reset();
432 sys::fs::rename(TmpArchive, ArcName);
433 return std::make_pair("", std::error_code());