f7a8da3384
This adds the LinkingContext parameter to the ELFReader. Previously the flags in that were needed in the Context was passed to the ELFReader, this made it very hard to access data structures in the LinkingContext when reading an ELF file. This change makes the ELFReader more flexible so that required parameters can be grabbed directly from the LinkingContext. Future patches make use of the changes. There is no change in functionality though. llvm-svn: 228905
119 lines
3.7 KiB
C++
119 lines
3.7 KiB
C++
//===- lib/ReaderWriter/ELF/DynamicFile.h ---------------------------------===//
|
|
//
|
|
// The LLVM Linker
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLD_READER_WRITER_ELF_DYNAMIC_FILE_H
|
|
#define LLD_READER_WRITER_ELF_DYNAMIC_FILE_H
|
|
|
|
#include "Atoms.h"
|
|
#include "lld/Core/SharedLibraryFile.h"
|
|
#include "lld/ReaderWriter/ELFLinkingContext.h"
|
|
#include "llvm/Object/ELF.h"
|
|
#include "llvm/Support/Path.h"
|
|
#include <unordered_map>
|
|
|
|
namespace lld {
|
|
namespace elf {
|
|
template <class ELFT> class DynamicFile : public SharedLibraryFile {
|
|
public:
|
|
static ErrorOr<std::unique_ptr<DynamicFile>>
|
|
create(std::unique_ptr<llvm::MemoryBuffer> mb, ELFLinkingContext &ctx);
|
|
|
|
const SharedLibraryAtom *exports(StringRef name,
|
|
bool dataSymbolOnly) const override {
|
|
assert(!dataSymbolOnly && "Invalid option for ELF exports!");
|
|
// See if we have the symbol.
|
|
auto sym = _nameToSym.find(name);
|
|
if (sym == _nameToSym.end())
|
|
return nullptr;
|
|
// Have we already created a SharedLibraryAtom for it?
|
|
if (sym->second._atom)
|
|
return sym->second._atom;
|
|
// Create a SharedLibraryAtom for this symbol.
|
|
return sym->second._atom = new (_alloc) ELFDynamicAtom<ELFT>(
|
|
*this, name, _soname, sym->second._symbol);
|
|
}
|
|
|
|
StringRef getDSOName() const override { return _soname; }
|
|
|
|
protected:
|
|
std::error_code doParse() override {
|
|
std::error_code ec;
|
|
_objFile.reset(
|
|
new llvm::object::ELFFile<ELFT>(_mb->getBuffer(), ec));
|
|
if (ec)
|
|
return ec;
|
|
|
|
llvm::object::ELFFile<ELFT> &obj = *_objFile;
|
|
|
|
_soname = obj.getLoadName();
|
|
if (_soname.empty())
|
|
_soname = llvm::sys::path::filename(path());
|
|
|
|
// Create a map from names to dynamic symbol table entries.
|
|
// TODO: This should use the object file's build in hash table instead if
|
|
// it exists.
|
|
for (auto i = obj.begin_dynamic_symbols(), e = obj.end_dynamic_symbols();
|
|
i != e; ++i) {
|
|
auto name = obj.getSymbolName(i);
|
|
if ((ec = name.getError()))
|
|
return ec;
|
|
|
|
// TODO: Add absolute symbols
|
|
if (i->st_shndx == llvm::ELF::SHN_ABS)
|
|
continue;
|
|
|
|
if (i->st_shndx == llvm::ELF::SHN_UNDEF) {
|
|
if (!_useShlibUndefines)
|
|
continue;
|
|
// Create an undefined atom.
|
|
if (!name->empty()) {
|
|
auto *newAtom = new (_alloc) ELFUndefinedAtom<ELFT>(*this, *name, &*i);
|
|
_undefinedAtoms._atoms.push_back(newAtom);
|
|
}
|
|
continue;
|
|
}
|
|
_nameToSym[*name]._symbol = &*i;
|
|
}
|
|
return std::error_code();
|
|
}
|
|
|
|
private:
|
|
DynamicFile(std::unique_ptr<MemoryBuffer> mb, ELFLinkingContext &ctx)
|
|
: SharedLibraryFile(mb->getBufferIdentifier()), _mb(std::move(mb)),
|
|
_ctx(ctx), _useShlibUndefines(ctx.useShlibUndefines()) {}
|
|
|
|
mutable llvm::BumpPtrAllocator _alloc;
|
|
std::unique_ptr<llvm::object::ELFFile<ELFT>> _objFile;
|
|
/// \brief DT_SONAME
|
|
StringRef _soname;
|
|
|
|
struct SymAtomPair {
|
|
SymAtomPair() : _symbol(nullptr), _atom(nullptr) {}
|
|
const typename llvm::object::ELFFile<ELFT>::Elf_Sym *_symbol;
|
|
const SharedLibraryAtom *_atom;
|
|
};
|
|
|
|
std::unique_ptr<MemoryBuffer> _mb;
|
|
ELFLinkingContext &_ctx;
|
|
bool _useShlibUndefines;
|
|
mutable std::unordered_map<StringRef, SymAtomPair> _nameToSym;
|
|
};
|
|
|
|
template <class ELFT>
|
|
ErrorOr<std::unique_ptr<DynamicFile<ELFT>>>
|
|
DynamicFile<ELFT>::create(std::unique_ptr<llvm::MemoryBuffer> mb,
|
|
ELFLinkingContext &ctx) {
|
|
return std::unique_ptr<DynamicFile>(new DynamicFile(std::move(mb), ctx));
|
|
}
|
|
|
|
} // end namespace elf
|
|
} // end namespace lld
|
|
|
|
#endif
|