//===- 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/Support/Endian.h" #include "llvm/Support/MemoryBuffer.h" using namespace llvm; using namespace object; static const char *Magic = "!\n"; static bool isInternalMember(const ArchiveMemberHeader &amh) { static const char *const internals[] = { "/", "//", "#_LLVM_SYM_TAB_#" }; StringRef name = amh.getName(); for (std::size_t i = 0; i < sizeof(internals) / sizeof(*internals); ++i) { if (name == internals[i]) return true; } return false; } void Archive::anchor() { } error_code Archive::Child::getName(StringRef &Result) const { StringRef name = ToHeader(Data.data())->getName(); // Check if it's a special name. if (name[0] == '/') { if (name.size() == 1) { // Linker member. Result = name; return object_error::success; } if (name.size() == 2 && name[1] == '/') { // String table. Result = name; return object_error::success; } // 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->end_children() || 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) { StringRef::size_type End = StringRef(addr).find('/'); Result = StringRef(addr, End); } else { Result = addr; } return object_error::success; } 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"); Result = Data.substr(sizeof(ArchiveMemberHeader), name_size); return object_error::success; } // It's a simple name. if (name[name.size() - 1] == '/') Result = name.substr(0, name.size() - 1); else Result = name; return object_error::success; } error_code Archive::Child::getAsBinary(OwningPtr &Result) const { OwningPtr ret; OwningPtr Buff; if (error_code ec = getMemoryBuffer(Buff)) return ec; if (error_code ec = createBinary(Buff.take(), ret)) return ec; Result.swap(ret); return object_error::success; } Archive::Archive(MemoryBuffer *source, error_code &ec) : Binary(Binary::ID_Archive, source) { // Check for sufficient magic. if (!source || source->getBufferSize() < (8 + sizeof(ArchiveMemberHeader) + 2) // Smallest archive. || StringRef(source->getBufferStart(), 8) != Magic) { ec = object_error::invalid_file_type; return; } // Get the special members. child_iterator i = begin_children(false); child_iterator e = end_children(); StringRef name; if ((ec = i->getName(name))) return; // Below is the pattern that is used to figure out the archive format // GNU archive format // First member : / (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 (points to the symbol table) // There is no string table, if the filename exceeds 15 characters or has a // embedded space, the filename has #1/, 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 == "/") { SymbolTable = i; StringTable = e; if (i != e) ++i; if (i == e) { ec = object_error::parse_failed; return; } if ((ec = i->getName(name))) return; if (name[0] != '/') { Format = K_GNU; } else if ((name.size() > 1) && (name == "//")) { Format = K_GNU; StringTable = i; ++i; } else { Format = K_COFF; if (i != e) { SymbolTable = i; ++i; } if (i != e) { if ((ec = i->getName(name))) return; if (name == "//") StringTable = i; } } } else if (name == "__.SYMDEF") { Format = K_BSD; SymbolTable = i; StringTable = e; } ec = object_error::success; } Archive::child_iterator Archive::begin_children(bool skip_internal) const { const char *Loc = Data->getBufferStart() + strlen(Magic); size_t Size = sizeof(ArchiveMemberHeader) + ToHeader(Loc)->getSize(); Child c(this, StringRef(Loc, Size)); // Skip internals at the beginning of an archive. if (skip_internal && isInternalMember(*ToHeader(Loc))) return c.getNext(); return c; } Archive::child_iterator Archive::end_children() const { return Child(this, StringRef(0, 0)); } error_code Archive::Symbol::getName(StringRef &Result) const { Result = StringRef(Parent->SymbolTable->getBuffer().begin() + StringIndex); return object_error::success; } error_code Archive::Symbol::getMember(child_iterator &Result) const { const char *Buf = Parent->SymbolTable->getBuffer().begin(); const char *Offsets = Buf + 4; uint32_t Offset = 0; if (Parent->kind() == K_GNU) { Offset = *(reinterpret_cast(Offsets) + SymbolIndex); } else if (Parent->kind() == K_BSD) { llvm_unreachable("BSD format is not supported"); } else { uint32_t MemberCount = *reinterpret_cast(Buf); // Skip offsets. Buf += sizeof(support::ulittle32_t) + (MemberCount * sizeof(support::ulittle32_t)); uint32_t SymbolCount = *reinterpret_cast(Buf); if (SymbolIndex >= SymbolCount) return object_error::parse_failed; // Skip SymbolCount to get to the indices table. const char *Indices = Buf + sizeof(support::ulittle32_t); // Get the index of the offset in the file member offset table for this // symbol. uint16_t OffsetIndex = *(reinterpret_cast(Indices) + SymbolIndex); // Subtract 1 since OffsetIndex is 1 based. --OffsetIndex; if (OffsetIndex >= MemberCount) return object_error::parse_failed; Offset = *(reinterpret_cast(Offsets) + OffsetIndex); } const char *Loc = Parent->getData().begin() + Offset; size_t Size = sizeof(ArchiveMemberHeader) + ToHeader(Loc)->getSize(); Result = Child(Parent, StringRef(Loc, Size)); return object_error::success; } Archive::Symbol Archive::Symbol::getNext() const { Symbol t(*this); // Go to one past next null. t.StringIndex = Parent->SymbolTable->getBuffer().find('\0', t.StringIndex) + 1; ++t.SymbolIndex; return t; } Archive::symbol_iterator Archive::begin_symbols() const { const char *buf = SymbolTable->getBuffer().begin(); if (kind() == K_GNU) { uint32_t symbol_count = 0; symbol_count = *reinterpret_cast(buf); buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t))); } else if (kind() == K_BSD) { llvm_unreachable("BSD archive format is not supported"); } else { uint32_t member_count = 0; uint32_t symbol_count = 0; member_count = *reinterpret_cast(buf); buf += 4 + (member_count * 4); // Skip offsets. symbol_count = *reinterpret_cast(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::end_symbols() const { const char *buf = SymbolTable->getBuffer().begin(); uint32_t symbol_count = 0; if (kind() == K_GNU) { symbol_count = *reinterpret_cast(buf); buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t))); } else if (kind() == K_BSD) { llvm_unreachable("BSD archive format is not supported"); } else { uint32_t member_count = 0; member_count = *reinterpret_cast(buf); buf += 4 + (member_count * 4); // Skip offsets. symbol_count = *reinterpret_cast(buf); } return symbol_iterator( Symbol(this, symbol_count, 0)); } Archive::child_iterator Archive::findSym(StringRef name) const { Archive::symbol_iterator bs = begin_symbols(); Archive::symbol_iterator es = end_symbols(); Archive::child_iterator result; StringRef symname; for (; bs != es; ++bs) { if (bs->getName(symname)) return end_children(); if (symname == name) { if (bs->getMember(result)) return end_children(); return result; } } return end_children(); }