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| //===- lib/ReaderWriter/FileArchive.cpp -----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lld/Common/LLVM.h"
#include "lld/Core/ArchiveLibraryFile.h"
#include "lld/Core/File.h"
#include "lld/Core/Reader.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/Error.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <memory>
#include <set>
#include <string>
#include <system_error>
#include <unordered_map>
#include <utility>
#include <vector>
using llvm::object::Archive;
using llvm::file_magic;
using llvm::identify_magic;
namespace lld {
namespace {
/// The FileArchive class represents an Archive Library file
class FileArchive : public lld::ArchiveLibraryFile {
public:
FileArchive(std::unique_ptr<MemoryBuffer> mb, const Registry ®,
StringRef path, bool logLoading)
: ArchiveLibraryFile(path), _mb(std::shared_ptr<MemoryBuffer>(mb.release())),
_registry(reg), _logLoading(logLoading) {}
/// Check if any member of the archive contains an Atom with the
/// specified name and return the File object for that member, or nullptr.
File *find(StringRef name) override {
auto member = _symbolMemberMap.find(name);
if (member == _symbolMemberMap.end())
return nullptr;
Archive::Child c = member->second;
// Don't return a member already returned
Expected<StringRef> buf = c.getBuffer();
if (!buf) {
// TODO: Actually report errors helpfully.
consumeError(buf.takeError());
return nullptr;
}
const char *memberStart = buf->data();
if (_membersInstantiated.count(memberStart))
return nullptr;
_membersInstantiated.insert(memberStart);
std::unique_ptr<File> result;
if (instantiateMember(c, result))
return nullptr;
File *file = result.get();
_filesReturned.push_back(std::move(result));
// Give up the file pointer. It was stored and will be destroyed with destruction of FileArchive
return file;
}
/// parse each member
std::error_code
parseAllMembers(std::vector<std::unique_ptr<File>> &result) override {
if (std::error_code ec = parse())
return ec;
llvm::Error err = llvm::Error::success();
for (auto mf = _archive->child_begin(err), me = _archive->child_end();
mf != me; ++mf) {
std::unique_ptr<File> file;
if (std::error_code ec = instantiateMember(*mf, file)) {
// err is Success (or we wouldn't be in the loop body) but we can't
// return without testing or consuming it.
consumeError(std::move(err));
return ec;
}
result.push_back(std::move(file));
}
if (err)
return errorToErrorCode(std::move(err));
return std::error_code();
}
const AtomRange<DefinedAtom> defined() const override {
return _noDefinedAtoms;
}
const AtomRange<UndefinedAtom> undefined() const override {
return _noUndefinedAtoms;
}
const AtomRange<SharedLibraryAtom> sharedLibrary() const override {
return _noSharedLibraryAtoms;
}
const AtomRange<AbsoluteAtom> absolute() const override {
return _noAbsoluteAtoms;
}
void clearAtoms() override {
_noDefinedAtoms.clear();
_noUndefinedAtoms.clear();
_noSharedLibraryAtoms.clear();
_noAbsoluteAtoms.clear();
}
protected:
std::error_code doParse() override {
// Make Archive object which will be owned by FileArchive object.
llvm::Error Err = llvm::Error::success();
_archive.reset(new Archive(_mb->getMemBufferRef(), Err));
if (Err)
return errorToErrorCode(std::move(Err));
std::error_code ec;
if ((ec = buildTableOfContents()))
return ec;
return std::error_code();
}
private:
std::error_code instantiateMember(Archive::Child member,
std::unique_ptr<File> &result) const {
Expected<llvm::MemoryBufferRef> mbOrErr = member.getMemoryBufferRef();
if (!mbOrErr)
return errorToErrorCode(mbOrErr.takeError());
llvm::MemoryBufferRef mb = mbOrErr.get();
std::string memberPath = (_archive->getFileName() + "("
+ mb.getBufferIdentifier() + ")").str();
if (_logLoading)
llvm::errs() << memberPath << "\n";
std::unique_ptr<MemoryBuffer> memberMB(MemoryBuffer::getMemBuffer(
mb.getBuffer(), mb.getBufferIdentifier(), false));
ErrorOr<std::unique_ptr<File>> fileOrErr =
_registry.loadFile(std::move(memberMB));
if (std::error_code ec = fileOrErr.getError())
return ec;
result = std::move(fileOrErr.get());
if (std::error_code ec = result->parse())
return ec;
result->setArchivePath(_archive->getFileName());
// The memory buffer is co-owned by the archive file and the children,
// so that the bufffer is deallocated when all the members are destructed.
result->setSharedMemoryBuffer(_mb);
return std::error_code();
}
std::error_code buildTableOfContents() {
DEBUG_WITH_TYPE("FileArchive", llvm::dbgs()
<< "Table of contents for archive '"
<< _archive->getFileName() << "':\n");
for (const Archive::Symbol &sym : _archive->symbols()) {
StringRef name = sym.getName();
Expected<Archive::Child> memberOrErr = sym.getMember();
if (!memberOrErr)
return errorToErrorCode(memberOrErr.takeError());
Archive::Child member = memberOrErr.get();
DEBUG_WITH_TYPE("FileArchive",
llvm::dbgs()
<< llvm::format("0x%08llX ",
member.getBuffer()->data())
<< "'" << name << "'\n");
_symbolMemberMap.insert(std::make_pair(name, member));
}
return std::error_code();
}
typedef std::unordered_map<StringRef, Archive::Child> MemberMap;
typedef std::set<const char *> InstantiatedSet;
std::shared_ptr<MemoryBuffer> _mb;
const Registry &_registry;
std::unique_ptr<Archive> _archive;
MemberMap _symbolMemberMap;
InstantiatedSet _membersInstantiated;
bool _logLoading;
std::vector<std::unique_ptr<MemoryBuffer>> _memberBuffers;
std::vector<std::unique_ptr<File>> _filesReturned;
};
class ArchiveReader : public Reader {
public:
ArchiveReader(bool logLoading) : _logLoading(logLoading) {}
bool canParse(file_magic magic, MemoryBufferRef) const override {
return magic == file_magic::archive;
}
ErrorOr<std::unique_ptr<File>> loadFile(std::unique_ptr<MemoryBuffer> mb,
const Registry ®) const override {
StringRef path = mb->getBufferIdentifier();
std::unique_ptr<File> ret =
std::make_unique<FileArchive>(std::move(mb), reg, path, _logLoading);
return std::move(ret);
}
private:
bool _logLoading;
};
} // anonymous namespace
void Registry::addSupportArchives(bool logLoading) {
add(std::unique_ptr<Reader>(new ArchiveReader(logLoading)));
}
} // namespace lld
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