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/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"
28
29 #if !defined(_MSC_VER) && !defined(__MINGW32__)
30 #include <unistd.h>
31 #else
32 #include <io.h>
33 #endif
34
35 using namespace llvm;
36
NewArchiveIterator(object::Archive::child_iterator I,StringRef Name)37 NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
38 StringRef Name)
39 : IsNewMember(false), Name(Name), OldI(I) {}
40
NewArchiveIterator(StringRef NewFilename,StringRef Name)41 NewArchiveIterator::NewArchiveIterator(StringRef NewFilename, StringRef Name)
42 : IsNewMember(true), Name(Name), NewFilename(NewFilename) {}
43
getName() const44 StringRef NewArchiveIterator::getName() const { return Name; }
45
isNewMember() const46 bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
47
getOld() const48 object::Archive::child_iterator NewArchiveIterator::getOld() const {
49 assert(!IsNewMember);
50 return OldI;
51 }
52
getNew() const53 StringRef NewArchiveIterator::getNew() const {
54 assert(IsNewMember);
55 return NewFilename;
56 }
57
58 llvm::ErrorOr<int>
getFD(sys::fs::file_status & NewStatus) const59 NewArchiveIterator::getFD(sys::fs::file_status &NewStatus) const {
60 assert(IsNewMember);
61 int NewFD;
62 if (auto EC = sys::fs::openFileForRead(NewFilename, NewFD))
63 return EC;
64 assert(NewFD != -1);
65
66 if (auto EC = sys::fs::status(NewFD, NewStatus))
67 return EC;
68
69 // Opening a directory doesn't make sense. Let it fail.
70 // Linux cannot open directories with open(2), although
71 // cygwin and *bsd can.
72 if (NewStatus.type() == sys::fs::file_type::directory_file)
73 return make_error_code(errc::is_a_directory);
74
75 return NewFD;
76 }
77
78 template <typename T>
printWithSpacePadding(raw_fd_ostream & OS,T Data,unsigned Size,bool MayTruncate=false)79 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
80 bool MayTruncate = false) {
81 uint64_t OldPos = OS.tell();
82 OS << Data;
83 unsigned SizeSoFar = OS.tell() - OldPos;
84 if (Size > SizeSoFar) {
85 OS.indent(Size - SizeSoFar);
86 } else if (Size < SizeSoFar) {
87 assert(MayTruncate && "Data doesn't fit in Size");
88 // Some of the data this is used for (like UID) can be larger than the
89 // space available in the archive format. Truncate in that case.
90 OS.seek(OldPos + Size);
91 }
92 }
93
print32(raw_ostream & Out,object::Archive::Kind Kind,uint32_t Val)94 static void print32(raw_ostream &Out, object::Archive::Kind Kind,
95 uint32_t Val) {
96 if (Kind == object::Archive::K_GNU)
97 support::endian::Writer<support::big>(Out).write(Val);
98 else
99 support::endian::Writer<support::little>(Out).write(Val);
100 }
101
printRestOfMemberHeader(raw_fd_ostream & Out,const sys::TimeValue & ModTime,unsigned UID,unsigned GID,unsigned Perms,unsigned Size)102 static void printRestOfMemberHeader(raw_fd_ostream &Out,
103 const sys::TimeValue &ModTime, unsigned UID,
104 unsigned GID, unsigned Perms,
105 unsigned Size) {
106 printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
107 printWithSpacePadding(Out, UID, 6, true);
108 printWithSpacePadding(Out, GID, 6, true);
109 printWithSpacePadding(Out, format("%o", Perms), 8);
110 printWithSpacePadding(Out, Size, 10);
111 Out << "`\n";
112 }
113
printGNUSmallMemberHeader(raw_fd_ostream & Out,StringRef Name,const sys::TimeValue & ModTime,unsigned UID,unsigned GID,unsigned Perms,unsigned Size)114 static void printGNUSmallMemberHeader(raw_fd_ostream &Out, StringRef Name,
115 const sys::TimeValue &ModTime,
116 unsigned UID, unsigned GID,
117 unsigned Perms, unsigned Size) {
118 printWithSpacePadding(Out, Twine(Name) + "/", 16);
119 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
120 }
121
printBSDMemberHeader(raw_fd_ostream & Out,StringRef Name,const sys::TimeValue & ModTime,unsigned UID,unsigned GID,unsigned Perms,unsigned Size)122 static void printBSDMemberHeader(raw_fd_ostream &Out, StringRef Name,
123 const sys::TimeValue &ModTime, unsigned UID,
124 unsigned GID, unsigned Perms, unsigned Size) {
125 uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
126 // Pad so that even 64 bit object files are aligned.
127 unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
128 unsigned NameWithPadding = Name.size() + Pad;
129 printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
130 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
131 NameWithPadding + Size);
132 Out << Name;
133 assert(PosAfterHeader == Out.tell());
134 while (Pad--)
135 Out.write(uint8_t(0));
136 }
137
138 static void
printMemberHeader(raw_fd_ostream & Out,object::Archive::Kind Kind,StringRef Name,std::vector<unsigned>::iterator & StringMapIndexIter,const sys::TimeValue & ModTime,unsigned UID,unsigned GID,unsigned Perms,unsigned Size)139 printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind,
140 StringRef Name,
141 std::vector<unsigned>::iterator &StringMapIndexIter,
142 const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
143 unsigned Perms, unsigned Size) {
144 if (Kind == object::Archive::K_BSD)
145 return printBSDMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
146 if (Name.size() < 16)
147 return printGNUSmallMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
148 Out << '/';
149 printWithSpacePadding(Out, *StringMapIndexIter++, 15);
150 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
151 }
152
writeStringTable(raw_fd_ostream & Out,ArrayRef<NewArchiveIterator> Members,std::vector<unsigned> & StringMapIndexes)153 static void writeStringTable(raw_fd_ostream &Out,
154 ArrayRef<NewArchiveIterator> Members,
155 std::vector<unsigned> &StringMapIndexes) {
156 unsigned StartOffset = 0;
157 for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
158 E = Members.end();
159 I != E; ++I) {
160 StringRef Name = I->getName();
161 if (Name.size() < 16)
162 continue;
163 if (StartOffset == 0) {
164 printWithSpacePadding(Out, "//", 58);
165 Out << "`\n";
166 StartOffset = Out.tell();
167 }
168 StringMapIndexes.push_back(Out.tell() - StartOffset);
169 Out << Name << "/\n";
170 }
171 if (StartOffset == 0)
172 return;
173 if (Out.tell() % 2)
174 Out << '\n';
175 int Pos = Out.tell();
176 Out.seek(StartOffset - 12);
177 printWithSpacePadding(Out, Pos - StartOffset, 10);
178 Out.seek(Pos);
179 }
180
now(bool Deterministic)181 static sys::TimeValue now(bool Deterministic) {
182 if (!Deterministic)
183 return sys::TimeValue::now();
184 sys::TimeValue TV;
185 TV.fromEpochTime(0);
186 return TV;
187 }
188
189 // Returns the offset of the first reference to a member offset.
190 static ErrorOr<unsigned>
writeSymbolTable(raw_fd_ostream & Out,object::Archive::Kind Kind,ArrayRef<NewArchiveIterator> Members,ArrayRef<MemoryBufferRef> Buffers,std::vector<unsigned> & MemberOffsetRefs,bool Deterministic)191 writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
192 ArrayRef<NewArchiveIterator> Members,
193 ArrayRef<MemoryBufferRef> Buffers,
194 std::vector<unsigned> &MemberOffsetRefs, bool Deterministic) {
195 unsigned HeaderStartOffset = 0;
196 unsigned BodyStartOffset = 0;
197 SmallString<128> NameBuf;
198 raw_svector_ostream NameOS(NameBuf);
199 LLVMContext Context;
200 for (unsigned MemberNum = 0, N = Members.size(); MemberNum < N; ++MemberNum) {
201 MemoryBufferRef MemberBuffer = Buffers[MemberNum];
202 ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
203 object::SymbolicFile::createSymbolicFile(
204 MemberBuffer, sys::fs::file_magic::unknown, &Context);
205 if (!ObjOrErr)
206 continue; // FIXME: check only for "not an object file" errors.
207 object::SymbolicFile &Obj = *ObjOrErr.get();
208
209 if (!HeaderStartOffset) {
210 HeaderStartOffset = Out.tell();
211 if (Kind == object::Archive::K_GNU)
212 printGNUSmallMemberHeader(Out, "", now(Deterministic), 0, 0, 0, 0);
213 else
214 printBSDMemberHeader(Out, "__.SYMDEF", now(Deterministic), 0, 0, 0, 0);
215 BodyStartOffset = Out.tell();
216 print32(Out, Kind, 0); // number of entries or bytes
217 }
218
219 for (const object::BasicSymbolRef &S : Obj.symbols()) {
220 uint32_t Symflags = S.getFlags();
221 if (Symflags & object::SymbolRef::SF_FormatSpecific)
222 continue;
223 if (!(Symflags & object::SymbolRef::SF_Global))
224 continue;
225 if (Symflags & object::SymbolRef::SF_Undefined)
226 continue;
227
228 unsigned NameOffset = NameOS.tell();
229 if (auto EC = S.printName(NameOS))
230 return EC;
231 NameOS << '\0';
232 MemberOffsetRefs.push_back(MemberNum);
233 if (Kind == object::Archive::K_BSD)
234 print32(Out, Kind, NameOffset);
235 print32(Out, Kind, 0); // member offset
236 }
237 }
238
239 if (HeaderStartOffset == 0)
240 return 0;
241
242 StringRef StringTable = NameOS.str();
243 if (Kind == object::Archive::K_BSD)
244 print32(Out, Kind, StringTable.size()); // byte count of the string table
245 Out << StringTable;
246
247 // ld64 requires the next member header to start at an offset that is
248 // 4 bytes aligned.
249 unsigned Pad = OffsetToAlignment(Out.tell(), 4);
250 while (Pad--)
251 Out.write(uint8_t(0));
252
253 // Patch up the size of the symbol table now that we know how big it is.
254 unsigned Pos = Out.tell();
255 const unsigned MemberHeaderSize = 60;
256 Out.seek(HeaderStartOffset + 48); // offset of the size field.
257 printWithSpacePadding(Out, Pos - MemberHeaderSize - HeaderStartOffset, 10);
258
259 // Patch up the number of symbols.
260 Out.seek(BodyStartOffset);
261 unsigned NumSyms = MemberOffsetRefs.size();
262 if (Kind == object::Archive::K_GNU)
263 print32(Out, Kind, NumSyms);
264 else
265 print32(Out, Kind, NumSyms * 8);
266
267 Out.seek(Pos);
268 return BodyStartOffset + 4;
269 }
270
writeArchive(StringRef ArcName,std::vector<NewArchiveIterator> & NewMembers,bool WriteSymtab,object::Archive::Kind Kind,bool Deterministic)271 std::pair<StringRef, std::error_code> llvm::writeArchive(
272 StringRef ArcName, std::vector<NewArchiveIterator> &NewMembers,
273 bool WriteSymtab, object::Archive::Kind Kind, bool Deterministic) {
274 SmallString<128> TmpArchive;
275 int TmpArchiveFD;
276 if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
277 TmpArchiveFD, TmpArchive))
278 return std::make_pair(ArcName, EC);
279
280 tool_output_file Output(TmpArchive, TmpArchiveFD);
281 raw_fd_ostream &Out = Output.os();
282 Out << "!<arch>\n";
283
284 std::vector<unsigned> MemberOffsetRefs;
285
286 std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
287 std::vector<MemoryBufferRef> Members;
288 std::vector<sys::fs::file_status> NewMemberStatus;
289
290 for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
291 NewArchiveIterator &Member = NewMembers[I];
292 MemoryBufferRef MemberRef;
293
294 if (Member.isNewMember()) {
295 StringRef Filename = Member.getNew();
296 NewMemberStatus.resize(NewMemberStatus.size() + 1);
297 sys::fs::file_status &Status = NewMemberStatus.back();
298 ErrorOr<int> FD = Member.getFD(Status);
299 if (auto EC = FD.getError())
300 return std::make_pair(Filename, EC);
301 ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
302 MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
303 false);
304 if (auto EC = MemberBufferOrErr.getError())
305 return std::make_pair(Filename, EC);
306 if (close(FD.get()) != 0)
307 return std::make_pair(Filename,
308 std::error_code(errno, std::generic_category()));
309 Buffers.push_back(std::move(MemberBufferOrErr.get()));
310 MemberRef = Buffers.back()->getMemBufferRef();
311 } else {
312 object::Archive::child_iterator OldMember = Member.getOld();
313 ErrorOr<MemoryBufferRef> MemberBufferOrErr =
314 OldMember->getMemoryBufferRef();
315 if (auto EC = MemberBufferOrErr.getError())
316 return std::make_pair("", EC);
317 MemberRef = MemberBufferOrErr.get();
318 }
319 Members.push_back(MemberRef);
320 }
321
322 unsigned MemberReferenceOffset = 0;
323 if (WriteSymtab) {
324 ErrorOr<unsigned> MemberReferenceOffsetOrErr = writeSymbolTable(
325 Out, Kind, NewMembers, Members, MemberOffsetRefs, Deterministic);
326 if (auto EC = MemberReferenceOffsetOrErr.getError())
327 return std::make_pair(ArcName, EC);
328 MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
329 }
330
331 std::vector<unsigned> StringMapIndexes;
332 if (Kind != object::Archive::K_BSD)
333 writeStringTable(Out, NewMembers, StringMapIndexes);
334
335 unsigned MemberNum = 0;
336 unsigned NewMemberNum = 0;
337 std::vector<unsigned>::iterator StringMapIndexIter = StringMapIndexes.begin();
338 std::vector<unsigned> MemberOffset;
339 for (const NewArchiveIterator &I : NewMembers) {
340 MemoryBufferRef File = Members[MemberNum++];
341
342 unsigned Pos = Out.tell();
343 MemberOffset.push_back(Pos);
344
345 sys::TimeValue ModTime;
346 unsigned UID;
347 unsigned GID;
348 unsigned Perms;
349 if (Deterministic) {
350 ModTime.fromEpochTime(0);
351 UID = 0;
352 GID = 0;
353 Perms = 0644;
354 } else if (I.isNewMember()) {
355 const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum];
356 ModTime = Status.getLastModificationTime();
357 UID = Status.getUser();
358 GID = Status.getGroup();
359 Perms = Status.permissions();
360 } else {
361 object::Archive::child_iterator OldMember = I.getOld();
362 ModTime = OldMember->getLastModified();
363 UID = OldMember->getUID();
364 GID = OldMember->getGID();
365 Perms = OldMember->getAccessMode();
366 }
367
368 if (I.isNewMember()) {
369 StringRef FileName = I.getNew();
370 const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum++];
371 printMemberHeader(Out, Kind, sys::path::filename(FileName),
372 StringMapIndexIter, ModTime, UID, GID, Perms,
373 Status.getSize());
374 } else {
375 object::Archive::child_iterator OldMember = I.getOld();
376 printMemberHeader(Out, Kind, I.getName(), StringMapIndexIter, ModTime,
377 UID, GID, Perms, OldMember->getSize());
378 }
379
380 Out << File.getBuffer();
381
382 if (Out.tell() % 2)
383 Out << '\n';
384 }
385
386 if (MemberReferenceOffset) {
387 Out.seek(MemberReferenceOffset);
388 for (unsigned MemberNum : MemberOffsetRefs) {
389 if (Kind == object::Archive::K_BSD)
390 Out.seek(Out.tell() + 4); // skip over the string offset
391 print32(Out, Kind, MemberOffset[MemberNum]);
392 }
393 }
394
395 Output.keep();
396 Out.close();
397 sys::fs::rename(TmpArchive, ArcName);
398 return std::make_pair("", std::error_code());
399 }
400