//===- Archive.cpp - ar File Format implementation --------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines the ArchiveObjectFile class. // //===----------------------------------------------------------------------===// #include "llvm/Object/Archive.h" #include "llvm/ADT/APInt.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/Twine.h" #include "llvm/Support/Endian.h" #include "llvm/Support/MemoryBuffer.h" using namespace llvm; using namespace object; using namespace llvm::support::endian; static const char *const Magic = "!<arch>\n"; static const char *const ThinMagic = "!<thin>\n"; void Archive::anchor() { } StringRef ArchiveMemberHeader::getName() const { char EndCond; if (Name[0] == '/' || Name[0] == '#') EndCond = ' '; else EndCond = '/'; llvm::StringRef::size_type end = llvm::StringRef(Name, sizeof(Name)).find(EndCond); if (end == llvm::StringRef::npos) end = sizeof(Name); assert(end <= sizeof(Name) && end > 0); // Don't include the EndCond if there is one. return llvm::StringRef(Name, end); } uint32_t ArchiveMemberHeader::getSize() const { uint32_t Ret; if (llvm::StringRef(Size, sizeof(Size)).rtrim(" ").getAsInteger(10, Ret)) llvm_unreachable("Size is not a decimal number."); return Ret; } sys::fs::perms ArchiveMemberHeader::getAccessMode() const { unsigned Ret; if (StringRef(AccessMode, sizeof(AccessMode)).rtrim(" ").getAsInteger(8, Ret)) llvm_unreachable("Access mode is not an octal number."); return static_cast<sys::fs::perms>(Ret); } sys::TimeValue ArchiveMemberHeader::getLastModified() const { unsigned Seconds; if (StringRef(LastModified, sizeof(LastModified)).rtrim(" ") .getAsInteger(10, Seconds)) llvm_unreachable("Last modified time not a decimal number."); sys::TimeValue Ret; Ret.fromEpochTime(Seconds); return Ret; } unsigned ArchiveMemberHeader::getUID() const { unsigned Ret; if (StringRef(UID, sizeof(UID)).rtrim(" ").getAsInteger(10, Ret)) llvm_unreachable("UID time not a decimal number."); return Ret; } unsigned ArchiveMemberHeader::getGID() const { unsigned Ret; if (StringRef(GID, sizeof(GID)).rtrim(" ").getAsInteger(10, Ret)) llvm_unreachable("GID time not a decimal number."); return Ret; } Archive::Child::Child(const Archive *Parent, const char *Start) : Parent(Parent) { if (!Start) return; const ArchiveMemberHeader *Header = reinterpret_cast<const ArchiveMemberHeader *>(Start); uint64_t Size = sizeof(ArchiveMemberHeader); if (!Parent->IsThin || Header->getName() == "/" || Header->getName() == "//") Size += Header->getSize(); Data = StringRef(Start, Size); // Setup StartOfFile and PaddingBytes. StartOfFile = sizeof(ArchiveMemberHeader); // Don't include attached name. StringRef Name = Header->getName(); if (Name.startswith("#1/")) { uint64_t NameSize; if (Name.substr(3).rtrim(" ").getAsInteger(10, NameSize)) llvm_unreachable("Long name length is not an integer"); StartOfFile += NameSize; } } uint64_t Archive::Child::getSize() const { if (Parent->IsThin) return getHeader()->getSize(); return Data.size() - StartOfFile; } uint64_t Archive::Child::getRawSize() const { return getHeader()->getSize(); } Archive::Child Archive::Child::getNext() const { size_t SpaceToSkip = Data.size(); // If it's odd, add 1 to make it even. if (SpaceToSkip & 1) ++SpaceToSkip; const char *NextLoc = Data.data() + SpaceToSkip; // Check to see if this is past the end of the archive. if (NextLoc >= Parent->Data.getBufferEnd()) return Child(Parent, nullptr); return Child(Parent, NextLoc); } uint64_t Archive::Child::getChildOffset() const { const char *a = Parent->Data.getBuffer().data(); const char *c = Data.data(); uint64_t offset = c - a; return offset; } ErrorOr<StringRef> Archive::Child::getName() const { StringRef name = getRawName(); // Check if it's a special name. if (name[0] == '/') { if (name.size() == 1) // Linker member. return name; if (name.size() == 2 && name[1] == '/') // String table. return name; // It's a long name. // Get the offset. std::size_t offset; if (name.substr(1).rtrim(" ").getAsInteger(10, offset)) llvm_unreachable("Long name offset is not an integer"); const char *addr = Parent->StringTable->Data.begin() + sizeof(ArchiveMemberHeader) + offset; // Verify it. if (Parent->StringTable == Parent->child_end() || addr < (Parent->StringTable->Data.begin() + sizeof(ArchiveMemberHeader)) || addr > (Parent->StringTable->Data.begin() + sizeof(ArchiveMemberHeader) + Parent->StringTable->getSize())) return object_error::parse_failed; // GNU long file names end with a /. if (Parent->kind() == K_GNU || Parent->kind() == K_MIPS64) { StringRef::size_type End = StringRef(addr).find('/'); return StringRef(addr, End); } return StringRef(addr); } else if (name.startswith("#1/")) { uint64_t name_size; if (name.substr(3).rtrim(" ").getAsInteger(10, name_size)) llvm_unreachable("Long name length is not an ingeter"); return Data.substr(sizeof(ArchiveMemberHeader), name_size) .rtrim(StringRef("\0", 1)); } // It's a simple name. if (name[name.size() - 1] == '/') return name.substr(0, name.size() - 1); return name; } ErrorOr<MemoryBufferRef> Archive::Child::getMemoryBufferRef() const { ErrorOr<StringRef> NameOrErr = getName(); if (std::error_code EC = NameOrErr.getError()) return EC; StringRef Name = NameOrErr.get(); return MemoryBufferRef(getBuffer(), Name); } ErrorOr<std::unique_ptr<Binary>> Archive::Child::getAsBinary(LLVMContext *Context) const { ErrorOr<MemoryBufferRef> BuffOrErr = getMemoryBufferRef(); if (std::error_code EC = BuffOrErr.getError()) return EC; return createBinary(BuffOrErr.get(), Context); } ErrorOr<std::unique_ptr<Archive>> Archive::create(MemoryBufferRef Source) { std::error_code EC; std::unique_ptr<Archive> Ret(new Archive(Source, EC)); if (EC) return EC; return std::move(Ret); } Archive::Archive(MemoryBufferRef Source, std::error_code &ec) : Binary(Binary::ID_Archive, Source), SymbolTable(child_end()) { StringRef Buffer = Data.getBuffer(); // Check for sufficient magic. if (Buffer.startswith(ThinMagic)) { IsThin = true; } else if (Buffer.startswith(Magic)) { IsThin = false; } else { ec = object_error::invalid_file_type; return; } // Get the special members. child_iterator i = child_begin(false); child_iterator e = child_end(); if (i == e) { ec = object_error::success; return; } StringRef Name = i->getRawName(); // Below is the pattern that is used to figure out the archive format // GNU archive format // First member : / (may exist, if it exists, points to the symbol table ) // Second member : // (may exist, if it exists, points to the string table) // Note : The string table is used if the filename exceeds 15 characters // BSD archive format // First member : __.SYMDEF or "__.SYMDEF SORTED" (the symbol table) // There is no string table, if the filename exceeds 15 characters or has a // embedded space, the filename has #1/<size>, The size represents the size // of the filename that needs to be read after the archive header // COFF archive format // First member : / // Second member : / (provides a directory of symbols) // Third member : // (may exist, if it exists, contains the string table) // Note: Microsoft PE/COFF Spec 8.3 says that the third member is present // even if the string table is empty. However, lib.exe does not in fact // seem to create the third member if there's no member whose filename // exceeds 15 characters. So the third member is optional. if (Name == "__.SYMDEF") { Format = K_BSD; SymbolTable = i; ++i; FirstRegular = i; ec = object_error::success; return; } if (Name.startswith("#1/")) { Format = K_BSD; // We know this is BSD, so getName will work since there is no string table. ErrorOr<StringRef> NameOrErr = i->getName(); ec = NameOrErr.getError(); if (ec) return; Name = NameOrErr.get(); if (Name == "__.SYMDEF SORTED" || Name == "__.SYMDEF") { SymbolTable = i; ++i; } FirstRegular = i; return; } // MIPS 64-bit ELF archives use a special format of a symbol table. // This format is marked by `ar_name` field equals to "/SYM64/". // For detailed description see page 96 in the following document: // http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf bool has64SymTable = false; if (Name == "/" || Name == "/SYM64/") { SymbolTable = i; if (Name == "/SYM64/") has64SymTable = true; ++i; if (i == e) { ec = object_error::parse_failed; return; } Name = i->getRawName(); } if (Name == "//") { Format = has64SymTable ? K_MIPS64 : K_GNU; StringTable = i; ++i; FirstRegular = i; ec = object_error::success; return; } if (Name[0] != '/') { Format = has64SymTable ? K_MIPS64 : K_GNU; FirstRegular = i; ec = object_error::success; return; } if (Name != "/") { ec = object_error::parse_failed; return; } Format = K_COFF; SymbolTable = i; ++i; if (i == e) { FirstRegular = i; ec = object_error::success; return; } Name = i->getRawName(); if (Name == "//") { StringTable = i; ++i; } FirstRegular = i; ec = object_error::success; } Archive::child_iterator Archive::child_begin(bool SkipInternal) const { if (Data.getBufferSize() == 8) // empty archive. return child_end(); if (SkipInternal) return FirstRegular; const char *Loc = Data.getBufferStart() + strlen(Magic); Child c(this, Loc); return c; } Archive::child_iterator Archive::child_end() const { return Child(this, nullptr); } StringRef Archive::Symbol::getName() const { return Parent->SymbolTable->getBuffer().begin() + StringIndex; } ErrorOr<Archive::child_iterator> Archive::Symbol::getMember() const { const char *Buf = Parent->SymbolTable->getBuffer().begin(); const char *Offsets = Buf; if (Parent->kind() == K_MIPS64) Offsets += sizeof(uint64_t); else Offsets += sizeof(uint32_t); uint32_t Offset = 0; if (Parent->kind() == K_GNU) { Offset = read32be(Offsets + SymbolIndex * 4); } else if (Parent->kind() == K_MIPS64) { Offset = read64be(Offsets + SymbolIndex * 8); } else if (Parent->kind() == K_BSD) { // The SymbolIndex is an index into the ranlib structs that start at // Offsets (the first uint32_t is the number of bytes of the ranlib // structs). The ranlib structs are a pair of uint32_t's the first // being a string table offset and the second being the offset into // the archive of the member that defines the symbol. Which is what // is needed here. Offset = read32le(Offsets + SymbolIndex * 8 + 4); } else { // Skip offsets. uint32_t MemberCount = read32le(Buf); Buf += MemberCount * 4 + 4; uint32_t SymbolCount = read32le(Buf); if (SymbolIndex >= SymbolCount) return object_error::parse_failed; // Skip SymbolCount to get to the indices table. const char *Indices = Buf + 4; // Get the index of the offset in the file member offset table for this // symbol. uint16_t OffsetIndex = read16le(Indices + SymbolIndex * 2); // Subtract 1 since OffsetIndex is 1 based. --OffsetIndex; if (OffsetIndex >= MemberCount) return object_error::parse_failed; Offset = read32le(Offsets + OffsetIndex * 4); } const char *Loc = Parent->getData().begin() + Offset; child_iterator Iter(Child(Parent, Loc)); return Iter; } Archive::Symbol Archive::Symbol::getNext() const { Symbol t(*this); if (Parent->kind() == K_BSD) { // t.StringIndex is an offset from the start of the __.SYMDEF or // "__.SYMDEF SORTED" member into the string table for the ranlib // struct indexed by t.SymbolIndex . To change t.StringIndex to the // offset in the string table for t.SymbolIndex+1 we subtract the // its offset from the start of the string table for t.SymbolIndex // and add the offset of the string table for t.SymbolIndex+1. // The __.SYMDEF or "__.SYMDEF SORTED" member starts with a uint32_t // which is the number of bytes of ranlib structs that follow. The ranlib // structs are a pair of uint32_t's the first being a string table offset // and the second being the offset into the archive of the member that // define the symbol. After that the next uint32_t is the byte count of // the string table followed by the string table. const char *Buf = Parent->SymbolTable->getBuffer().begin(); uint32_t RanlibCount = 0; RanlibCount = read32le(Buf) / 8; // If t.SymbolIndex + 1 will be past the count of symbols (the RanlibCount) // don't change the t.StringIndex as we don't want to reference a ranlib // past RanlibCount. if (t.SymbolIndex + 1 < RanlibCount) { const char *Ranlibs = Buf + 4; uint32_t CurRanStrx = 0; uint32_t NextRanStrx = 0; CurRanStrx = read32le(Ranlibs + t.SymbolIndex * 8); NextRanStrx = read32le(Ranlibs + (t.SymbolIndex + 1) * 8); t.StringIndex -= CurRanStrx; t.StringIndex += NextRanStrx; } } else { // Go to one past next null. t.StringIndex = Parent->SymbolTable->getBuffer().find('\0', t.StringIndex) + 1; } ++t.SymbolIndex; return t; } Archive::symbol_iterator Archive::symbol_begin() const { if (!hasSymbolTable()) return symbol_iterator(Symbol(this, 0, 0)); const char *buf = SymbolTable->getBuffer().begin(); if (kind() == K_GNU) { uint32_t symbol_count = 0; symbol_count = read32be(buf); buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t))); } else if (kind() == K_MIPS64) { uint64_t symbol_count = read64be(buf); buf += sizeof(uint64_t) + (symbol_count * (sizeof(uint64_t))); } else if (kind() == K_BSD) { // The __.SYMDEF or "__.SYMDEF SORTED" member starts with a uint32_t // which is the number of bytes of ranlib structs that follow. The ranlib // structs are a pair of uint32_t's the first being a string table offset // and the second being the offset into the archive of the member that // define the symbol. After that the next uint32_t is the byte count of // the string table followed by the string table. uint32_t ranlib_count = 0; ranlib_count = read32le(buf) / 8; const char *ranlibs = buf + 4; uint32_t ran_strx = 0; ran_strx = read32le(ranlibs); buf += sizeof(uint32_t) + (ranlib_count * (2 * (sizeof(uint32_t)))); // Skip the byte count of the string table. buf += sizeof(uint32_t); buf += ran_strx; } else { uint32_t member_count = 0; uint32_t symbol_count = 0; member_count = read32le(buf); buf += 4 + (member_count * 4); // Skip offsets. symbol_count = read32le(buf); buf += 4 + (symbol_count * 2); // Skip indices. } uint32_t string_start_offset = buf - SymbolTable->getBuffer().begin(); return symbol_iterator(Symbol(this, 0, string_start_offset)); } Archive::symbol_iterator Archive::symbol_end() const { if (!hasSymbolTable()) return symbol_iterator(Symbol(this, 0, 0)); const char *buf = SymbolTable->getBuffer().begin(); uint32_t symbol_count = 0; if (kind() == K_GNU) { symbol_count = read32be(buf); } else if (kind() == K_MIPS64) { symbol_count = read64be(buf); } else if (kind() == K_BSD) { symbol_count = read32le(buf) / 8; } else { uint32_t member_count = 0; member_count = read32le(buf); buf += 4 + (member_count * 4); // Skip offsets. symbol_count = read32le(buf); } return symbol_iterator(Symbol(this, symbol_count, 0)); } Archive::child_iterator Archive::findSym(StringRef name) const { Archive::symbol_iterator bs = symbol_begin(); Archive::symbol_iterator es = symbol_end(); for (; bs != es; ++bs) { StringRef SymName = bs->getName(); if (SymName == name) { ErrorOr<Archive::child_iterator> ResultOrErr = bs->getMember(); // FIXME: Should we really eat the error? if (ResultOrErr.getError()) return child_end(); return ResultOrErr.get(); } } return child_end(); } bool Archive::hasSymbolTable() const { return SymbolTable != child_end(); }