//===- GNUArchiveReader.cpp -----------------------------------------------===//
//
// The MCLinker Project
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <mcld/MC/MCLDInfo.h>
#include <mcld/MC/MCLDInput.h>
#include <mcld/MC/InputTree.h>
#include <mcld/LD/GNUArchiveReader.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/MemoryAreaFactory.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(MCLDInfo& pLDInfo,
MemoryAreaFactory& pMemAreaFactory,
ELFObjectReader& pELFObjectReader)
: m_LDInfo(pLDInfo),
m_MemAreaFactory(pMemAreaFactory),
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)
{
// 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) {
Input* cur_archive = &(pArchive.getARFile());
Input* member = cur_archive;
uint32_t file_offset = pArchive.getObjFileOffset(idx);
while ((member != NULL) && (Input::Object != member->type())) {
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);
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(pArchive.getObjFileOffset(idx),
parent->lastPos);
m_ELFObjectReader.readObject(*member);
m_ELFObjectReader.readSections(*member);
m_ELFObjectReader.readSymbols(*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;
}
} // end of while
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
Input* GNUArchiveReader::readMemberHeader(Archive& pArchiveRoot,
Input& pArchiveFile,
uint32_t pFileOffset,
uint32_t& pNestedOffset)
{
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, 2));
// int size = atoi(header->size);
// parse the member name and nested offset if any
std::string member_name;
llvm::StringRef name_field(header->name, 16);
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
begin = name_offset;
end = pArchiveRoot.getStrTable().find_first_of('\n', begin);
member_name.assign(pArchiveRoot.getStrTable().substr(begin, end - begin -1));
}
Input* member = NULL;
if (!isThinArchive(pArchiveFile)) {
// this is an object file in an archive
member =
m_LDInfo.inputFactory().produce(member_name,
pArchiveFile.path(),
Input::Unknown,
(pFileOffset +
sizeof(Archive::MemberHeader)));
assert(member != NULL);
member->setMemArea(pArchiveFile.memArea());
LDContext *input_context = m_LDInfo.contextFactory().produce();
member->setContext(input_context);
}
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 =
m_LDInfo.inputFactory().produce(member_name, input_path, Input::Unknown);
assert(member != NULL);
MemoryArea* input_memory =
m_MemAreaFactory.produce(member->path(), FileHandle::ReadOnly);
if (input_memory->handler()->isGood()) {
member->setMemArea(input_memory);
}
else {
error(diag::err_cannot_open_input) << member->name() << member->path();
return NULL;
}
LDContext *input_context = m_LDInfo.contextFactory().produce(input_path);
member->setContext(input_context);
}
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, 2));
int symtab_size = atoi(header->size);
pArchive.setSymTabSize(symtab_size);
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 = 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, bswap32(*data));
else
pArchive.addSymbol(name, *data);
name += strlen(name) + 1;
++data;
}
pArchive.getARFile().memArea()->release(header_region);
pArchive.getARFile().memArea()->release(symtab_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, 2));
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(header_region);
pArchive.getARFile().memArea()->release(strtab_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
ResolveInfo* info = m_LDInfo.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;
}