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//===- lib/ReaderWriter/ELF/Mips/MipsTargetHandler.cpp --------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "File.h"
#include "MipsLinkingContext.h"
#include "MipsTargetHandler.h"
using namespace lld;
using namespace elf;
namespace {
class MipsDynamicSymbolTable : public DynamicSymbolTable<Mips32ElELFType> {
public:
MipsDynamicSymbolTable(const MipsLinkingContext &context)
: DynamicSymbolTable<Mips32ElELFType>(
context, ".dynsym",
DefaultLayout<Mips32ElELFType>::ORDER_DYNAMIC_SYMBOLS),
_layout(context.getTargetLayout()) {}
virtual void sortSymbols() {
std::stable_sort(_symbolTable.begin(), _symbolTable.end(),
[this](const SymbolEntry &A, const SymbolEntry &B) {
if (A._symbol.getBinding() != STB_GLOBAL &&
B._symbol.getBinding() != STB_GLOBAL)
return A._symbol.getBinding() < B._symbol.getBinding();
return _layout.getGOTSection().compare(A._atom, B._atom);
});
}
private:
const MipsTargetLayout<Mips32ElELFType> &_layout;
};
class MipsDynamicTable : public DynamicTable<Mips32ElELFType> {
public:
MipsDynamicTable(MipsLinkingContext &context)
: DynamicTable<Mips32ElELFType>(
context, ".dynamic", DefaultLayout<Mips32ElELFType>::ORDER_DYNAMIC),
_layout(context.getTargetLayout()) {}
virtual void createDefaultEntries() {
DynamicTable<Mips32ElELFType>::createDefaultEntries();
Elf_Dyn dyn;
// Version id for the Runtime Linker Interface.
dyn.d_un.d_val = 1;
dyn.d_tag = DT_MIPS_RLD_VERSION;
addEntry(dyn);
// MIPS flags.
dyn.d_un.d_val = RHF_NOTPOT;
dyn.d_tag = DT_MIPS_FLAGS;
addEntry(dyn);
// The base address of the segment.
dyn.d_un.d_ptr = 0;
dyn.d_tag = DT_MIPS_BASE_ADDRESS;
addEntry(dyn);
// Number of local global offset table entries.
dyn.d_un.d_val = 0;
dyn.d_tag = DT_MIPS_LOCAL_GOTNO;
_dt_localgot = addEntry(dyn);
// Number of entries in the .dynsym section.
dyn.d_un.d_val = 0;
dyn.d_tag = DT_MIPS_SYMTABNO;
_dt_symtabno = addEntry(dyn);
// The index of the first dynamic symbol table entry that corresponds
// to an entry in the global offset table.
dyn.d_un.d_val = 0;
dyn.d_tag = DT_MIPS_GOTSYM;
_dt_gotsym = addEntry(dyn);
// Address of the .got section.
dyn.d_un.d_val = 0;
dyn.d_tag = DT_PLTGOT;
_dt_pltgot = addEntry(dyn);
}
virtual void updateDynamicTable() {
DynamicTable<Mips32ElELFType>::updateDynamicTable();
auto &got = _layout.getGOTSection();
_entries[_dt_symtabno].d_un.d_val = getSymbolTable()->size();
_entries[_dt_gotsym].d_un.d_val =
getSymbolTable()->size() - got.getGlobalCount();
_entries[_dt_localgot].d_un.d_val = got.getLocalCount();
_entries[_dt_pltgot].d_un.d_ptr =
_layout.findOutputSection(".got")->virtualAddr();
}
private:
MipsTargetLayout<Mips32ElELFType> &_layout;
std::size_t _dt_symtabno;
std::size_t _dt_localgot;
std::size_t _dt_gotsym;
std::size_t _dt_pltgot;
};
}
MipsTargetHandler::MipsTargetHandler(MipsLinkingContext &context)
: DefaultTargetHandler(context), _targetLayout(context),
_relocationHandler(context, *this) {}
uint64_t MipsTargetHandler::getGPDispSymAddr() const {
return _gpDispSymAtom ? _gpDispSymAtom->_virtualAddr : 0;
}
MipsTargetLayout<Mips32ElELFType> &MipsTargetHandler::targetLayout() {
return _targetLayout;
}
const MipsTargetRelocationHandler &
MipsTargetHandler::getRelocationHandler() const {
return _relocationHandler;
}
LLD_UNIQUE_BUMP_PTR(DynamicTable<Mips32ElELFType>)
MipsTargetHandler::createDynamicTable() {
return LLD_UNIQUE_BUMP_PTR(DynamicTable<Mips32ElELFType>)(
new (_alloc) MipsDynamicTable(
static_cast<MipsLinkingContext &>(_context)));
}
LLD_UNIQUE_BUMP_PTR(DynamicSymbolTable<Mips32ElELFType>)
MipsTargetHandler::createDynamicSymbolTable() {
return LLD_UNIQUE_BUMP_PTR(DynamicSymbolTable<Mips32ElELFType>)(
new (_alloc) MipsDynamicSymbolTable(
static_cast<MipsLinkingContext &>(_context)));
}
bool MipsTargetHandler::createImplicitFiles(
std::vector<std::unique_ptr<File>> &result) {
typedef CRuntimeFile<Mips32ElELFType> RFile;
auto file = std::unique_ptr<RFile>(new RFile(_context, "MIPS runtime file"));
if (_context.isDynamic()) {
file->addAbsoluteAtom("_GLOBAL_OFFSET_TABLE_");
file->addAbsoluteAtom("_gp_disp");
}
result.push_back(std::move(file));
return true;
}
void MipsTargetHandler::finalizeSymbolValues() {
DefaultTargetHandler<Mips32ElELFType>::finalizeSymbolValues();
if (_context.isDynamic()) {
auto gotSection = _targetLayout.findOutputSection(".got");
auto gotAtomIter = _targetLayout.findAbsoluteAtom("_GLOBAL_OFFSET_TABLE_");
assert(gotAtomIter != _targetLayout.absoluteAtoms().end());
_gotSymAtom = (*gotAtomIter);
_gotSymAtom->_virtualAddr = gotSection ? gotSection->virtualAddr() : 0;
auto gpDispAtomIter = _targetLayout.findAbsoluteAtom("_gp_disp");
assert(gpDispAtomIter != _targetLayout.absoluteAtoms().end());
_gpDispSymAtom = (*gpDispAtomIter);
_gpDispSymAtom->_virtualAddr =
gotSection ? gotSection->virtualAddr() + 0x7FF0 : 0;
}
}
void MipsTargetHandler::registerRelocationNames(Registry ®istry) {
registry.addKindTable(Reference::KindNamespace::ELF,
Reference::KindArch::Mips, kindStrings);
}
const Registry::KindStrings MipsTargetHandler::kindStrings[] = {
LLD_KIND_STRING_ENTRY(R_MIPS_NONE), LLD_KIND_STRING_ENTRY(R_MIPS_32),
LLD_KIND_STRING_ENTRY(R_MIPS_HI16), LLD_KIND_STRING_ENTRY(R_MIPS_LO16),
LLD_KIND_STRING_ENTRY(R_MIPS_GOT16), LLD_KIND_STRING_ENTRY(R_MIPS_CALL16),
LLD_KIND_STRING_ENTRY(R_MIPS_JALR), LLD_KIND_STRING_END
};
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