void ELFObjectWriter::emitSectionHeader(const Module& pModule,
const LinkerConfig& pConfig,
MemoryArea& pOutput) const
{
typedef typename ELFSizeTraits<SIZE>::Shdr ElfXX_Shdr;
// emit section header
unsigned int sectNum = pModule.size();
unsigned int header_size = sizeof(ElfXX_Shdr) * sectNum;
MemoryRegion* region = pOutput.request(getLastStartOffset<SIZE>(pModule),
header_size);
ElfXX_Shdr* shdr = (ElfXX_Shdr*)region->start();
// Iterate the SectionTable in LDContext
unsigned int sectIdx = 0;
unsigned int shstridx = 0; // NULL section has empty name
for (; sectIdx < sectNum; ++sectIdx) {
const LDSection *ld_sect = pModule.getSectionTable().at(sectIdx);
shdr[sectIdx].sh_name = shstridx;
shdr[sectIdx].sh_type = ld_sect->type();
shdr[sectIdx].sh_flags = ld_sect->flag();
shdr[sectIdx].sh_addr = ld_sect->addr();
shdr[sectIdx].sh_offset = ld_sect->offset();
shdr[sectIdx].sh_size = ld_sect->size();
shdr[sectIdx].sh_addralign = ld_sect->align();
shdr[sectIdx].sh_entsize = getSectEntrySize<SIZE>(*ld_sect);
shdr[sectIdx].sh_link = getSectLink(*ld_sect, pConfig);
shdr[sectIdx].sh_info = getSectInfo(*ld_sect);
// adjust strshidx
shstridx += ld_sect->name().size() + 1;
}
}
void ELFObjectWriter::emitProgramHeader(MemoryArea& pOutput) const
{
typedef typename ELFSizeTraits<SIZE>::Ehdr ElfXX_Ehdr;
typedef typename ELFSizeTraits<SIZE>::Phdr ElfXX_Phdr;
uint64_t start_offset, phdr_size;
start_offset = sizeof(ElfXX_Ehdr);
phdr_size = sizeof(ElfXX_Phdr);
// Program header must start directly after ELF header
MemoryRegion *region =
pOutput.request(start_offset,
target().elfSegmentTable().size() * phdr_size);
ElfXX_Phdr* phdr = (ElfXX_Phdr*)region->start();
// Iterate the elf segment table in GNULDBackend
size_t index = 0;
ELFSegmentFactory::const_iterator seg = target().elfSegmentTable().begin(),
segEnd = target().elfSegmentTable().end();
for (; seg != segEnd; ++seg, ++index) {
phdr[index].p_type = (*seg)->type();
phdr[index].p_flags = (*seg)->flag();
phdr[index].p_offset = (*seg)->offset();
phdr[index].p_vaddr = (*seg)->vaddr();
phdr[index].p_paddr = (*seg)->paddr();
phdr[index].p_filesz = (*seg)->filesz();
phdr[index].p_memsz = (*seg)->memsz();
phdr[index].p_align = (*seg)->align();
}
}
/// isMyFormat
bool ELFDynObjReader::isMyFormat(Input &pInput, bool &pContinue) const
{
assert(pInput.hasMemArea());
// Don't warning about the frequently requests.
// MemoryArea has a list of cache to handle this.
size_t hdr_size = m_pELFReader->getELFHeaderSize();
if (pInput.memArea()->size() < hdr_size)
return false;
MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
hdr_size);
uint8_t* ELF_hdr = region->start();
bool result = true;
if (!m_pELFReader->isELF(ELF_hdr)) {
pContinue = true;
result = false;
} else if (Input::DynObj != m_pELFReader->fileType(ELF_hdr)) {
pContinue = true;
result = false;
} else if (!m_pELFReader->isMyEndian(ELF_hdr)) {
pContinue = false;
result = false;
} else if (!m_pELFReader->isMyMachine(ELF_hdr)) {
pContinue = false;
result = false;
}
pInput.memArea()->release(region);
return result;
}
/// computePCBegin - return the address of FDE's pc
/// @ref binutils gold: ehframe.cc:222
uint32_t EhFrameHdr::computePCBegin(const EhFrame::FDE& pFDE,
const MemoryRegion& pEhFrameRegion)
{
uint8_t fde_encoding = pFDE.getCIE().getFDEEncode();
unsigned int eh_value = fde_encoding & 0x7;
// check the size to read in
if (eh_value == llvm::dwarf::DW_EH_PE_absptr) {
eh_value = DW_EH_PE_udata4;
}
size_t pc_size = 0x0;
switch (eh_value) {
case DW_EH_PE_udata2:
pc_size = 2;
break;
case DW_EH_PE_udata4:
pc_size = 4;
break;
case DW_EH_PE_udata8:
pc_size = 8;
break;
default:
// TODO
break;
}
SizeTraits<32>::Address pc = 0x0;
const uint8_t* offset = (const uint8_t*) pEhFrameRegion.start() +
pFDE.getOffset() +
pFDE.getDataStart();
std::memcpy(&pc, offset, pc_size);
// adjust the signed value
bool is_signed = (fde_encoding & llvm::dwarf::DW_EH_PE_signed) != 0x0;
if (DW_EH_PE_udata2 == eh_value && is_signed)
pc = (pc ^ 0x8000) - 0x8000;
// handle eh application
switch (fde_encoding & 0x70)
{
case DW_EH_PE_absptr:
break;
case DW_EH_PE_pcrel:
pc += m_EhFrame.addr() + pFDE.getOffset() + pFDE.getDataStart();
break;
case DW_EH_PE_datarel:
// TODO
break;
default:
// TODO
break;
}
return pc;
}
void ELFObjectWriter::writeELFHeader(const LinkerConfig& pConfig,
const Module& pModule,
MemoryArea& pOutput) const
{
typedef typename ELFSizeTraits<SIZE>::Ehdr ElfXX_Ehdr;
typedef typename ELFSizeTraits<SIZE>::Shdr ElfXX_Shdr;
typedef typename ELFSizeTraits<SIZE>::Phdr ElfXX_Phdr;
// ELF header must start from 0x0
MemoryRegion *region = pOutput.request(0, sizeof(ElfXX_Ehdr));
ElfXX_Ehdr* header = (ElfXX_Ehdr*)region->start();
memcpy(header->e_ident, ElfMagic, EI_MAG3+1);
header->e_ident[EI_CLASS] = (SIZE == 32) ? ELFCLASS32 : ELFCLASS64;
header->e_ident[EI_DATA] = pConfig.targets().isLittleEndian()?
ELFDATA2LSB : ELFDATA2MSB;
header->e_ident[EI_VERSION] = target().getInfo().ELFVersion();
header->e_ident[EI_OSABI] = target().getInfo().OSABI();
header->e_ident[EI_ABIVERSION] = target().getInfo().ABIVersion();
// FIXME: add processor-specific and core file types.
switch(pConfig.codeGenType()) {
case LinkerConfig::Object:
header->e_type = ET_REL;
break;
case LinkerConfig::DynObj:
header->e_type = ET_DYN;
break;
case LinkerConfig::Exec:
header->e_type = ET_EXEC;
break;
default:
llvm::errs() << "unspported output file type: " << pConfig.codeGenType() << ".\n";
header->e_type = ET_NONE;
}
header->e_machine = target().getInfo().machine();
header->e_version = header->e_ident[EI_VERSION];
header->e_entry = getEntryPoint(pConfig, pModule);
if (LinkerConfig::Object != pConfig.codeGenType())
header->e_phoff = sizeof(ElfXX_Ehdr);
else
header->e_phoff = 0x0;
header->e_shoff = getLastStartOffset<SIZE>(pModule);
header->e_flags = target().getInfo().flags();
header->e_ehsize = sizeof(ElfXX_Ehdr);
header->e_phentsize = sizeof(ElfXX_Phdr);
header->e_phnum = target().elfSegmentTable().size();
header->e_shentsize = sizeof(ElfXX_Shdr);
header->e_shnum = pModule.size();
header->e_shstrndx = pModule.getSection(".shstrtab")->index();
}
/// emitShStrTab - emit section string table
void
ELFObjectWriter::emitShStrTab(const LDSection& pShStrTab,
const Module& pModule,
MemoryArea& pOutput)
{
// write out data
MemoryRegion* region = pOutput.request(pShStrTab.offset(), pShStrTab.size());
unsigned char* data = region->start();
size_t shstrsize = 0;
Module::const_iterator section, sectEnd = pModule.end();
for (section = pModule.begin(); section != sectEnd; ++section) {
strcpy((char*)(data + shstrsize), (*section)->name().data());
shstrsize += (*section)->name().size() + 1;
}
}
// SetUp() will be called immediately before each test.
void ELFReaderTest::SetUp()
{
Path path(TOPDIR);
path.append("unittests/test_x86_64.o");
m_pInput = m_pIRBuilder->ReadInput("test_x86_64", path);
ASSERT_TRUE(NULL!=m_pInput);
ASSERT_TRUE(m_pInput->hasMemArea());
size_t hdr_size = m_pELFReader->getELFHeaderSize();
MemoryRegion* region = m_pInput->memArea()->request(m_pInput->fileOffset(),
hdr_size);
uint8_t* ELF_hdr = region->start();
bool shdr_result = m_pELFReader->readSectionHeaders(*m_pInput, ELF_hdr);
m_pInput->memArea()->release(region);
ASSERT_TRUE(shdr_result);
}
/// readDSO
bool ELFDynObjReader::readDSO(Input& pInput)
{
assert(pInput.hasMemArea());
size_t hdr_size = m_pELFReader->getELFHeaderSize();
MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
hdr_size);
uint8_t* ELF_hdr = region->start();
bool shdr_result = m_pELFReader->readSectionHeaders(pInput, m_Linker, ELF_hdr);
pInput.memArea()->release(region);
// read .dynamic to get the correct SONAME
bool dyn_result = m_pELFReader->readDynamic(pInput);
return (shdr_result && dyn_result);
}
void ELFObjectWriter::emitRela(const LinkerConfig& pConfig,
const RelocData& pRelocData,
MemoryRegion& pRegion) const
{
typedef typename ELFSizeTraits<SIZE>::Rela ElfXX_Rela;
typedef typename ELFSizeTraits<SIZE>::Addr ElfXX_Addr;
typedef typename ELFSizeTraits<SIZE>::Word ElfXX_Word;
ElfXX_Rela* rel = reinterpret_cast<ElfXX_Rela*>(pRegion.start());
const Relocation* relocation = 0;
const FragmentRef* frag_ref = 0;
for (RelocData::const_iterator it = pRelocData.begin(),
ie = pRelocData.end(); it != ie; ++it, ++rel) {
ElfXX_Addr r_offset = 0;
ElfXX_Word r_sym = 0;
relocation = &(llvm::cast<Relocation>(*it));
frag_ref = &(relocation->targetRef());
if(LinkerConfig::DynObj == pConfig.codeGenType() ||
LinkerConfig::Exec == pConfig.codeGenType()) {
r_offset = static_cast<ElfXX_Addr>(
frag_ref->frag()->getParent()->getSection().addr() +
frag_ref->getOutputOffset());
}
else {
r_offset = static_cast<ElfXX_Addr>(frag_ref->getOutputOffset());
}
if( relocation->symInfo() == NULL )
r_sym = 0;
else
r_sym = static_cast<ElfXX_Word>(
target().getSymbolIdx(relocation->symInfo()->outSymbol()));
target().emitRelocation(*rel, relocation->type(),
r_sym, r_offset, relocation->addend());
}
}
uint64_t ARMGNULDBackend::emitSectionData(const Output& pOutput,
const LDSection& pSection,
const MCLDInfo& pInfo,
MemoryRegion& pRegion) const
{
assert(pRegion.size() && "Size of MemoryRegion is zero!");
ELFFileFormat* file_format = getOutputFormat(pOutput);
if (&pSection == m_pAttributes) {
// FIXME: Currently Emitting .ARM.attributes directly from the input file.
const llvm::MCSectionData* sect_data = pSection.getSectionData();
assert(sect_data &&
"Emit .ARM.attribute failed, MCSectionData doesn't exist!");
uint8_t* start =
llvm::cast<MCRegionFragment>(
sect_data->getFragmentList().front()).getRegion().start();
memcpy(pRegion.start(), start, pRegion.size());
return pRegion.size();
}
if (&pSection == &(file_format->getPLT())) {
assert(NULL != m_pPLT && "emitSectionData failed, m_pPLT is NULL!");
uint64_t result = m_pPLT->emit(pRegion);
return result;
}
if (&pSection == &(file_format->getGOT())) {
assert(NULL != m_pGOT && "emitSectionData failed, m_pGOT is NULL!");
uint64_t result = m_pGOT->emit(pRegion);
return result;
}
llvm::report_fatal_error(llvm::Twine("Unable to emit section `") +
pSection.name() +
llvm::Twine("'.\n"));
return 0x0;
}
void raw_mem_ostream::write_impl(const char *pPtr, size_t pSize)
{
MemoryRegion* region = m_MemoryArea.request(m_Position, pSize);
memcpy(region->start(), pPtr, pSize);
m_Position += pSize;
}