| //===- GNUArchiveReader.cpp -----------------------------------------------===// |
| // |
| // The MCLinker Project |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| #include <mcld/LD/GNUArchiveReader.h> |
| |
| #include <mcld/Module.h> |
| #include <mcld/InputTree.h> |
| #include <mcld/MC/Attribute.h> |
| #include <mcld/MC/MCLDInput.h> |
| #include <mcld/LD/ResolveInfo.h> |
| #include <mcld/LD/ELFObjectReader.h> |
| #include <mcld/Support/FileSystem.h> |
| #include <mcld/Support/FileHandle.h> |
| #include <mcld/Support/MemoryArea.h> |
| #include <mcld/Support/MemoryRegion.h> |
| #include <mcld/Support/MsgHandling.h> |
| #include <mcld/Support/Path.h> |
| #include <mcld/ADT/SizeTraits.h> |
| |
| #include <llvm/ADT/StringRef.h> |
| #include <llvm/Support/Host.h> |
| |
| #include <cstring> |
| #include <cstdlib> |
| |
| using namespace mcld; |
| |
| GNUArchiveReader::GNUArchiveReader(Module& pModule, |
| ELFObjectReader& pELFObjectReader) |
| : m_Module(pModule), |
| m_ELFObjectReader(pELFObjectReader) |
| { |
| } |
| |
| GNUArchiveReader::~GNUArchiveReader() |
| { |
| } |
| |
| /// isMyFormat |
| bool GNUArchiveReader::isMyFormat(Input& pInput) const |
| { |
| assert(pInput.hasMemArea()); |
| MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(), |
| Archive::MAGIC_LEN); |
| const char* str = reinterpret_cast<const char*>(region->getBuffer()); |
| |
| bool result = false; |
| assert(NULL != str); |
| if (isArchive(str) || isThinArchive(str)) |
| result = true; |
| |
| pInput.memArea()->release(region); |
| return result; |
| } |
| |
| /// isArchive |
| bool GNUArchiveReader::isArchive(const char* pStr) const |
| { |
| return (0 == memcmp(pStr, Archive::MAGIC, Archive::MAGIC_LEN)); |
| } |
| |
| /// isThinArchive |
| bool GNUArchiveReader::isThinArchive(const char* pStr) const |
| { |
| return (0 == memcmp(pStr, Archive::THIN_MAGIC, Archive::MAGIC_LEN)); |
| } |
| |
| /// isThinArchive |
| bool GNUArchiveReader::isThinArchive(Input& pInput) const |
| { |
| assert(pInput.hasMemArea()); |
| MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(), |
| Archive::MAGIC_LEN); |
| const char* str = reinterpret_cast<const char*>(region->getBuffer()); |
| |
| bool result = false; |
| assert(NULL != str); |
| if (isThinArchive(str)) |
| result = true; |
| |
| pInput.memArea()->release(region); |
| return result; |
| } |
| |
| bool GNUArchiveReader::readArchive(Archive& pArchive) |
| { |
| // bypass the empty archive |
| if (Archive::MAGIC_LEN == pArchive.getARFile().memArea()->handler()->size()) |
| return true; |
| |
| if (pArchive.getARFile().attribute()->isWholeArchive()) |
| return includeAllMembers(pArchive); |
| |
| // if this is the first time read this archive, setup symtab and strtab |
| if (pArchive.getSymbolTable().empty()) { |
| // read the symtab of the archive |
| readSymbolTable(pArchive); |
| |
| // read the strtab of the archive |
| readStringTable(pArchive); |
| |
| // add root archive to ArchiveMemberMap |
| pArchive.addArchiveMember(pArchive.getARFile().name(), |
| pArchive.inputs().root(), |
| &InputTree::Downward); |
| } |
| |
| // include the needed members in the archive and build up the input tree |
| bool willSymResolved; |
| do { |
| willSymResolved = false; |
| for (size_t idx = 0; idx < pArchive.numOfSymbols(); ++idx) { |
| // bypass if we already decided to include this symbol or not |
| if (Archive::Symbol::Unknown != pArchive.getSymbolStatus(idx)) |
| continue; |
| |
| // bypass if another symbol with the same object file offset is included |
| if (pArchive.hasObjectMember(pArchive.getObjFileOffset(idx))) { |
| pArchive.setSymbolStatus(idx, Archive::Symbol::Include); |
| continue; |
| } |
| |
| // check if we should include this defined symbol |
| Archive::Symbol::Status status = |
| shouldIncludeSymbol(pArchive.getSymbolName(idx)); |
| if (Archive::Symbol::Unknown != status) |
| pArchive.setSymbolStatus(idx, status); |
| |
| if (Archive::Symbol::Include == status) { |
| // include the object member from the given offset |
| includeMember(pArchive, pArchive.getObjFileOffset(idx)); |
| willSymResolved = true; |
| } // end of if |
| } // end of for |
| } while (willSymResolved); |
| |
| return true; |
| } |
| |
| /// readMemberHeader - read the header of a member in a archive file and then |
| /// return the corresponding archive member (it may be an input object or |
| /// another archive) |
| /// @param pArchiveRoot - the archive root that holds the strtab (extended |
| /// name table) |
| /// @param pArchiveFile - the archive that contains the needed object |
| /// @param pFileOffset - file offset of the member header in the archive |
| /// @param pNestedOffset - used when we find a nested archive |
| /// @param pMemberSize - the file size of this member |
| Input* GNUArchiveReader::readMemberHeader(Archive& pArchiveRoot, |
| Input& pArchiveFile, |
| uint32_t pFileOffset, |
| uint32_t& pNestedOffset, |
| size_t& pMemberSize) |
| { |
| assert(pArchiveFile.hasMemArea()); |
| |
| MemoryRegion* header_region = |
| pArchiveFile.memArea()->request((pArchiveFile.fileOffset() + pFileOffset), |
| sizeof(Archive::MemberHeader)); |
| const Archive::MemberHeader* header = |
| reinterpret_cast<const Archive::MemberHeader*>(header_region->getBuffer()); |
| |
| assert(0 == memcmp(header->fmag, Archive::MEMBER_MAGIC, sizeof(header->fmag))); |
| |
| pMemberSize = atoi(header->size); |
| |
| // parse the member name and nested offset if any |
| std::string member_name; |
| llvm::StringRef name_field(header->name, sizeof(header->name)); |
| if ('/' != header->name[0]) { |
| // this is an object file in an archive |
| size_t pos = name_field.find_first_of('/'); |
| member_name.assign(name_field.substr(0, pos).str()); |
| } |
| else { |
| // this is an object/archive file in a thin archive |
| size_t begin = 1; |
| size_t end = name_field.find_first_of(" :"); |
| uint32_t name_offset = 0; |
| // parse the name offset |
| name_field.substr(begin, end - begin).getAsInteger(10, name_offset); |
| |
| if (':' == name_field[end]) { |
| // there is a nested offset |
| begin = end + 1; |
| end = name_field.find_first_of(' ', begin); |
| name_field.substr(begin, end - begin).getAsInteger(10, pNestedOffset); |
| } |
| |
| // get the member name from the extended name table |
| assert(pArchiveRoot.hasStrTable()); |
| begin = name_offset; |
| end = pArchiveRoot.getStrTable().find_first_of('\n', begin); |
| member_name.assign(pArchiveRoot.getStrTable().substr(begin, end - begin -1)); |
| } |
| |
| Input* member = NULL; |
| bool isThinAR = isThinArchive(pArchiveFile); |
| if (!isThinAR) { |
| // this is an object file in an archive |
| member = pArchiveRoot.getMemberFile(pArchiveFile, |
| isThinAR, |
| member_name, |
| pArchiveFile.path(), |
| (pFileOffset + |
| sizeof(Archive::MemberHeader))); |
| } |
| else { |
| // this is a member in a thin archive |
| // try to find if this is a archive already in the map first |
| Archive::ArchiveMember* ar_member = |
| pArchiveRoot.getArchiveMember(member_name); |
| if (NULL != ar_member) { |
| return ar_member->file; |
| } |
| |
| // get nested file path, the nested file's member name is the relative |
| // path to the archive containing it. |
| sys::fs::Path input_path(pArchiveFile.path().parent_path()); |
| if (!input_path.empty()) |
| input_path.append(member_name); |
| else |
| input_path.assign(member_name); |
| |
| member = pArchiveRoot.getMemberFile(pArchiveFile, |
| isThinAR, |
| member_name, |
| input_path); |
| } |
| |
| pArchiveFile.memArea()->release(header_region); |
| return member; |
| } |
| |
| /// readSymbolTable - read the archive symbol map (armap) |
| bool GNUArchiveReader::readSymbolTable(Archive& pArchive) |
| { |
| assert(pArchive.getARFile().hasMemArea()); |
| |
| MemoryRegion* header_region = |
| pArchive.getARFile().memArea()->request((pArchive.getARFile().fileOffset() + |
| Archive::MAGIC_LEN), |
| sizeof(Archive::MemberHeader)); |
| const Archive::MemberHeader* header = |
| reinterpret_cast<const Archive::MemberHeader*>(header_region->getBuffer()); |
| assert(0 == memcmp(header->fmag, Archive::MEMBER_MAGIC, sizeof(header->fmag))); |
| |
| int symtab_size = atoi(header->size); |
| pArchive.setSymTabSize(symtab_size); |
| |
| if (!pArchive.getARFile().attribute()->isWholeArchive()) { |
| MemoryRegion* symtab_region = |
| pArchive.getARFile().memArea()->request( |
| (pArchive.getARFile().fileOffset() + |
| Archive::MAGIC_LEN + |
| sizeof(Archive::MemberHeader)), |
| symtab_size); |
| const uint32_t* data = |
| reinterpret_cast<const uint32_t*>(symtab_region->getBuffer()); |
| |
| // read the number of symbols |
| uint32_t number = 0; |
| if (llvm::sys::isLittleEndianHost()) |
| number = mcld::bswap32(*data); |
| else |
| number = *data; |
| |
| // set up the pointers for file offset and name offset |
| ++data; |
| const char* name = reinterpret_cast<const char*>(data + number); |
| |
| // add the archive symbols |
| for (uint32_t i = 0; i < number; ++i) { |
| if (llvm::sys::isLittleEndianHost()) |
| pArchive.addSymbol(name, mcld::bswap32(*data)); |
| else |
| pArchive.addSymbol(name, *data); |
| name += strlen(name) + 1; |
| ++data; |
| } |
| pArchive.getARFile().memArea()->release(symtab_region); |
| } |
| pArchive.getARFile().memArea()->release(header_region); |
| return true; |
| } |
| |
| /// readStringTable - read the strtab for long file name of the archive |
| bool GNUArchiveReader::readStringTable(Archive& pArchive) |
| { |
| size_t offset = Archive::MAGIC_LEN + |
| sizeof(Archive::MemberHeader) + |
| pArchive.getSymTabSize(); |
| |
| if (0x0 != (offset & 1)) |
| ++offset; |
| |
| assert(pArchive.getARFile().hasMemArea()); |
| |
| MemoryRegion* header_region = |
| pArchive.getARFile().memArea()->request((pArchive.getARFile().fileOffset() + |
| offset), |
| sizeof(Archive::MemberHeader)); |
| const Archive::MemberHeader* header = |
| reinterpret_cast<const Archive::MemberHeader*>(header_region->getBuffer()); |
| |
| assert(0 == memcmp(header->fmag, Archive::MEMBER_MAGIC, sizeof(header->fmag))); |
| |
| if (0 == memcmp(header->name, Archive::STRTAB_NAME, sizeof(header->name))) { |
| // read the extended name table |
| int strtab_size = atoi(header->size); |
| MemoryRegion* strtab_region = |
| pArchive.getARFile().memArea()->request( |
| (pArchive.getARFile().fileOffset() + |
| offset + sizeof(Archive::MemberHeader)), |
| strtab_size); |
| const char* strtab = |
| reinterpret_cast<const char*>(strtab_region->getBuffer()); |
| pArchive.getStrTable().assign(strtab, strtab_size); |
| pArchive.getARFile().memArea()->release(strtab_region); |
| } |
| pArchive.getARFile().memArea()->release(header_region); |
| return true; |
| } |
| |
| /// shouldIncludeStatus - given a sym name from armap and check if including |
| /// the corresponding archive member, and then return the decision |
| enum Archive::Symbol::Status |
| GNUArchiveReader::shouldIncludeSymbol(const llvm::StringRef& pSymName) const |
| { |
| // TODO: handle symbol version issue and user defined symbols |
| const ResolveInfo* info = m_Module.getNamePool().findInfo(pSymName); |
| if (NULL != info) { |
| if (!info->isUndef()) |
| return Archive::Symbol::Exclude; |
| if (info->isWeak()) |
| return Archive::Symbol::Unknown; |
| return Archive::Symbol::Include; |
| } |
| return Archive::Symbol::Unknown; |
| } |
| |
| /// includeMember - include the object member in the given file offset, and |
| /// return the size of the object |
| /// @param pArchiveRoot - the archive root |
| /// @param pFileOffset - file offset of the member header in the archive |
| size_t GNUArchiveReader::includeMember(Archive& pArchive, uint32_t pFileOffset) |
| { |
| Input* cur_archive = &(pArchive.getARFile()); |
| Input* member = NULL; |
| uint32_t file_offset = pFileOffset; |
| size_t size = 0; |
| do { |
| uint32_t nested_offset = 0; |
| // use the file offset in current archive to find out the member we |
| // want to include |
| member = readMemberHeader(pArchive, |
| *cur_archive, |
| file_offset, |
| nested_offset, |
| size); |
| assert(member != NULL); |
| // bypass if we get an archive that is already in the map |
| if (Input::Archive == member->type()) { |
| cur_archive = member; |
| file_offset = nested_offset; |
| continue; |
| } |
| |
| // insert a node into the subtree of current archive. |
| Archive::ArchiveMember* parent = |
| pArchive.getArchiveMember(cur_archive->name()); |
| |
| assert(NULL != parent); |
| pArchive.inputs().insert(parent->lastPos, *(parent->move), *member); |
| |
| // move the iterator to new created node, and also adjust the |
| // direction to Afterward for next insertion in this subtree |
| parent->move->move(parent->lastPos); |
| parent->move = &InputTree::Afterward; |
| |
| if (m_ELFObjectReader.isMyFormat(*member)) { |
| member->setType(Input::Object); |
| pArchive.addObjectMember(pFileOffset, parent->lastPos); |
| m_ELFObjectReader.readHeader(*member); |
| m_ELFObjectReader.readSections(*member); |
| m_ELFObjectReader.readSymbols(*member); |
| m_Module.getObjectList().push_back(member); |
| } |
| else if (isMyFormat(*member)) { |
| member->setType(Input::Archive); |
| // when adding a new archive node, set the iterator to archive |
| // itself, and set the direction to Downward |
| pArchive.addArchiveMember(member->name(), |
| parent->lastPos, |
| &InputTree::Downward); |
| cur_archive = member; |
| file_offset = nested_offset; |
| } |
| } while (Input::Object != member->type()); |
| return size; |
| } |
| |
| /// includeAllMembers - include all object members. This is called if |
| /// --whole-archive is the attribute for this archive file. |
| bool GNUArchiveReader::includeAllMembers(Archive& pArchive) |
| { |
| // read the symtab of the archive |
| readSymbolTable(pArchive); |
| |
| // read the strtab of the archive |
| readStringTable(pArchive); |
| |
| // add root archive to ArchiveMemberMap |
| pArchive.addArchiveMember(pArchive.getARFile().name(), |
| pArchive.inputs().root(), |
| &InputTree::Downward); |
| |
| bool isThinAR = isThinArchive(pArchive.getARFile()); |
| uint32_t begin_offset = pArchive.getARFile().fileOffset() + |
| Archive::MAGIC_LEN + |
| sizeof(Archive::MemberHeader) + |
| pArchive.getSymTabSize(); |
| if (pArchive.hasStrTable()) { |
| if (0x0 != (begin_offset & 1)) |
| ++begin_offset; |
| begin_offset += sizeof(Archive::MemberHeader) + |
| pArchive.getStrTable().size(); |
| } |
| uint32_t end_offset = pArchive.getARFile().memArea()->handler()->size(); |
| for (uint32_t offset = begin_offset; |
| offset < end_offset; |
| offset += sizeof(Archive::MemberHeader)) { |
| |
| size_t size = includeMember(pArchive, offset); |
| |
| if (!isThinAR) { |
| offset += size; |
| } |
| |
| if (0x0 != (offset & 1)) |
| ++offset; |
| } |
| return true; |
| } |
| |
