llvm-project/lld/lib/ReaderWriter/ELF/DynamicLibraryWriter.h

98 lines
3.5 KiB
C++

//===- lib/ReaderWriter/ELF/DynamicLibraryWriter.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_LIBRARY_WRITER_H
#define LLD_READER_WRITER_ELF_DYNAMIC_LIBRARY_WRITER_H
#include "OutputELFWriter.h"
namespace lld {
namespace elf {
using namespace llvm;
using namespace llvm::object;
template<class ELFT>
class DynamicLibraryWriter;
//===----------------------------------------------------------------------===//
// DynamicLibraryWriter Class
//===----------------------------------------------------------------------===//
template<class ELFT>
class DynamicLibraryWriter : public OutputELFWriter<ELFT> {
public:
DynamicLibraryWriter(const ELFLinkingContext &context,
TargetLayout<ELFT> &layout)
: OutputELFWriter<ELFT>(context, layout),
_runtimeFile(new CRuntimeFile<ELFT>(context)) {}
protected:
virtual void buildDynamicSymbolTable(const File &file);
virtual void addDefaultAtoms();
virtual bool createImplicitFiles(std::vector<std::unique_ptr<File> > &);
virtual void finalizeDefaultAtomValues();
protected:
std::unique_ptr<CRuntimeFile<ELFT> > _runtimeFile;
};
//===----------------------------------------------------------------------===//
// DynamicLibraryWriter
//===----------------------------------------------------------------------===//
template <class ELFT>
void DynamicLibraryWriter<ELFT>::buildDynamicSymbolTable(const File &file) {
// Add all the defined symbols to the dynamic symbol table
// we need hooks into the Atom to find out which atoms need
// to be exported
for (auto sec : this->_layout.sections())
if (auto section = dyn_cast<AtomSection<ELFT>>(sec))
for (const auto &atom : section->atoms()) {
const DefinedAtom *da = dyn_cast<const DefinedAtom>(atom->_atom);
if (da && (da->scope() != DefinedAtom::scopeTranslationUnit))
this->_dynamicSymbolTable->addSymbol(atom->_atom, section->ordinal(),
atom->_virtualAddr, atom);
}
for (const UndefinedAtom *a : file.undefined())
this->_dynamicSymbolTable->addSymbol(a, ELF::SHN_UNDEF);
OutputELFWriter<ELFT>::buildDynamicSymbolTable(file);
}
template <class ELFT> void DynamicLibraryWriter<ELFT>::addDefaultAtoms() {
_runtimeFile->addAbsoluteAtom("_end");
}
/// \brief Hook in lld to add CRuntime file
template <class ELFT>
bool DynamicLibraryWriter<ELFT>::createImplicitFiles(
std::vector<std::unique_ptr<File> > &result) {
// Add the default atoms as defined by executables
DynamicLibraryWriter<ELFT>::addDefaultAtoms();
OutputELFWriter<ELFT>::createImplicitFiles(result);
result.push_back(std::move(_runtimeFile));
return true;
}
template <class ELFT>
void DynamicLibraryWriter<ELFT>::finalizeDefaultAtomValues() {
auto underScoreEndAtomIter = this->_layout.findAbsoluteAtom("_end");
if (auto bssSection = this->_layout.findOutputSection(".bss")) {
(*underScoreEndAtomIter)->_virtualAddr =
bssSection->virtualAddr() + bssSection->memSize();
} else if (auto dataSection = this->_layout.findOutputSection(".data")) {
(*underScoreEndAtomIter)->_virtualAddr =
dataSection->virtualAddr() + dataSection->memSize();
}
}
} // namespace elf
} // namespace lld
#endif // LLD_READER_WRITER_ELF_DYNAMIC_LIBRARY_WRITER_H