bool ARMGNULDBackend::mergeSection(Module& pModule,
const Input& pInput,
LDSection& pSection)
{
switch (pSection.type()) {
case llvm::ELF::SHT_ARM_ATTRIBUTES: {
return attribute().merge(pInput, pSection);
}
case llvm::ELF::SHT_ARM_EXIDX: {
assert(NULL != pSection.getLink());
if ((pSection.getLink()->kind() == LDFileFormat::Ignore) ||
(pSection.getLink()->kind() == LDFileFormat::Folded)) {
// if the target section of the .ARM.exidx is Ignore, then it should be
// ignored as well
pSection.setKind(LDFileFormat::Ignore);
return true;
}
}
/** fall through **/
default: {
ObjectBuilder builder(pModule);
builder.MergeSection(pInput, pSection);
return true;
}
} // end of switch
return true;
}
void HexagonRelocator::scanRelocation(Relocation& pReloc,
IRBuilder& pLinker,
Module& pModule,
LDSection& pSection,
Input& pInput) {
if (LinkerConfig::Object == config().codeGenType())
return;
// rsym - The relocation target symbol
ResolveInfo* rsym = pReloc.symInfo();
assert(rsym != NULL &&
"ResolveInfo of relocation not set while scanRelocation");
if (config().isCodeStatic())
return;
assert(pSection.getLink() != NULL);
if ((pSection.getLink()->flag() & llvm::ELF::SHF_ALLOC) == 0)
return;
if (rsym->isLocal()) // rsym is local
scanLocalReloc(pReloc, pLinker, pModule, pSection);
else // rsym is external
scanGlobalReloc(pReloc, pLinker, pModule, pSection);
// check if we should issue undefined reference for the relocation target
// symbol
if (rsym->isUndef() && !rsym->isDyn() && !rsym->isWeak() && !rsym->isNull())
issueUndefRef(pReloc, pSection, pInput);
}
void NyuziRelocator::scanRelocation(Relocation& pReloc,
IRBuilder& pBuilder,
Module& pModule,
LDSection& pSection,
Input& pInput)
{
ResolveInfo* rsym = pReloc.symInfo();
assert(NULL != rsym &&
"ResolveInfo of relocation not set while scanRelocation");
assert(NULL != pSection.getLink());
if (0 == (pSection.getLink()->flag() & llvm::ELF::SHF_ALLOC))
return;
// check if we shoule issue undefined reference for the relocation target
// symbol
if (rsym->isUndef() && !rsym->isDyn() && !rsym->isWeak() && !rsym->isNull())
issueUndefRef(pReloc, pSection, pInput);
}
void HexagonRelocator::scanLocalReloc(Relocation& pReloc,
IRBuilder& pBuilder,
Module& pModule,
LDSection& pSection) {
// rsym - The relocation target symbol
ResolveInfo* rsym = pReloc.symInfo();
switch (pReloc.type()) {
case llvm::ELF::R_HEX_LO16:
case llvm::ELF::R_HEX_HI16:
case llvm::ELF::R_HEX_16:
case llvm::ELF::R_HEX_8:
case llvm::ELF::R_HEX_32_6_X:
case llvm::ELF::R_HEX_16_X:
case llvm::ELF::R_HEX_12_X:
case llvm::ELF::R_HEX_11_X:
case llvm::ELF::R_HEX_10_X:
case llvm::ELF::R_HEX_9_X:
case llvm::ELF::R_HEX_8_X:
case llvm::ELF::R_HEX_7_X:
case llvm::ELF::R_HEX_6_X:
assert(!(rsym->reserved() & ReserveRel) &&
"Cannot apply this relocation for read only section");
return;
case llvm::ELF::R_HEX_32:
// If buiding PIC object (shared library or PIC executable),
// a dynamic relocations with RELATIVE type to this location is needed.
// Reserve an entry in .rel.dyn
if (config().isCodeIndep()) {
Relocation& reloc = helper_DynRel_init(rsym,
*pReloc.targetRef().frag(),
pReloc.targetRef().offset(),
llvm::ELF::R_HEX_RELATIVE,
*this);
// we need to set up the relocation addend at apply relocation, record
// the
// relocation
getRelRelMap().record(pReloc, reloc);
// set Rel bit
rsym->setReserved(rsym->reserved() | ReserveRel);
getTarget().checkAndSetHasTextRel(*pSection.getLink());
}
return;
default:
return;
}
}
/// getSectInfo - compute ElfXX_Shdr::sh_info
uint64_t ELFObjectWriter::getSectInfo(const LDSection& pSection) const
{
if (llvm::ELF::SHT_SYMTAB == pSection.type() ||
llvm::ELF::SHT_DYNSYM == pSection.type())
return pSection.getInfo();
if (llvm::ELF::SHT_REL == pSection.type() ||
llvm::ELF::SHT_RELA == pSection.type()) {
const LDSection* info_link = pSection.getLink();
if (NULL != info_link)
return info_link->index();
}
return 0x0;
}
void ARMGNULDBackend::scanInputExceptionSections(Module& pModule,
Input& pInput) {
std::unique_ptr<ARMInputExMap> exMap(new ARMInputExMap());
// Scan the input and collect all related sections.
LDContext* ctx = pInput.context();
for (LDContext::sect_iterator it = ctx->sectBegin(),
end = ctx->sectEnd(); it != end; ++it) {
LDSection* sect = *it;
llvm::StringRef name(sect->name());
if (name.startswith(".ARM.exidx")) {
ARMExSectionTuple* exTuple = exMap->getOrCreateByExSection(name);
exTuple->setExIdxSection(sect);
exTuple->setTextSection(sect->getLink());
} else if (name.startswith(".ARM.extab")) {
ARMExSectionTuple* exTuple = exMap->getOrCreateByExSection(name);
exTuple->setExTabSection(sect);
} else if (name.startswith(".rel.ARM.exidx")) {
ARMExSectionTuple* exTuple = exMap->getOrCreateByRelExSection(name);
exTuple->setRelExIdxSection(sect);
} else if (name.startswith(".rel.ARM.extab")) {
ARMExSectionTuple* exTuple = exMap->getOrCreateByRelExSection(name);
exTuple->setRelExIdxSection(sect);
}
}
// Remove the invalid exception tuples and convert LDSection to RegionFragment
// or RelocData.
ARMInputExMap::iterator it = exMap->begin();
ARMInputExMap::iterator end = exMap->end();
while (it != end) {
ARMExSectionTuple* exTuple = it->second.get();
LDSection* const text = exTuple->getTextSection();
LDSection* const exIdx = exTuple->getExIdxSection();
LDSection* const exTab = exTuple->getExTabSection();
LDSection* const relExIdx = exTuple->getRelExIdxSection();
LDSection* const relExTab = exTuple->getRelExTabSection();
// Check the .ARM.exidx section.
if (!exIdx) {
if (exTab) {
fatal(diag::eh_missing_exidx_section) << exTab->name() << pInput.name();
} else if (relExIdx) {
fatal(diag::eh_missing_exidx_section) << relExIdx->name()
<< pInput.name();
} else if (relExTab) {
fatal(diag::eh_missing_exidx_section) << relExTab->name()
<< pInput.name();
} else {
llvm_unreachable("unexpected bad exception tuple");
}
}
// Check the text section.
if (!text) {
fatal(diag::eh_missing_text_section) << exIdx->name() << pInput.name();
}
// Ignore the exception section if the text section is ignored.
if ((text->kind() == LDFileFormat::Ignore) ||
(text->kind() == LDFileFormat::Folded)) {
// Set the related exception sections as LDFileFormat::Ignore.
exIdx->setKind(LDFileFormat::Ignore);
if (exTab) {
exTab->setKind(LDFileFormat::Ignore);
}
// Remove this tuple from the input exception map.
exMap->erase(it++);
continue;
}
// Get RegionFragment from ".text", ".ARM.exidx", and ".ARM.extab" sections.
RegionFragment* textFrag = findRegionFragment(*text);
RegionFragment* exIdxFrag = findRegionFragment(*exIdx);
RegionFragment* exTabFrag = exTab ? findRegionFragment(*exTab) : NULL;
exTuple->setTextFragment(textFrag);
exTuple->setExIdxFragment(exIdxFrag);
exTuple->setExTabFragment(exTabFrag);
// Get the RelocData from ".rel.ARM.exidx" and ".rel.ARM.extab" sections.
RelocData* exIdxRD = relExIdx ? relExIdx->getRelocData() : NULL;
RelocData* exTabRD = relExTab ? relExTab->getRelocData() : NULL;
exTuple->setExIdxRelocData(exIdxRD);
exTuple->setExTabRelocData(exTabRD);
// If there is no region fragment in the .ARM.extab section, then we can
// skip this tuple.
if (!exIdxFrag) {
exMap->erase(it++);
continue;
}
// TODO: Sort the RelocData w.r.t. the fixup offset.
// Check next tuple
++it;
}
// Add input map
m_ExData.addInputMap(&pInput, std::move(exMap));
}
void HexagonRelocator::scanGlobalReloc(Relocation& pReloc,
IRBuilder& pBuilder,
Module& pModule,
LDSection& pSection) {
// rsym - The relocation target symbol
ResolveInfo* rsym = pReloc.symInfo();
HexagonLDBackend& ld_backend = getTarget();
switch (pReloc.type()) {
case llvm::ELF::R_HEX_LO16:
case llvm::ELF::R_HEX_HI16:
case llvm::ELF::R_HEX_16:
case llvm::ELF::R_HEX_8:
case llvm::ELF::R_HEX_32_6_X:
case llvm::ELF::R_HEX_16_X:
case llvm::ELF::R_HEX_12_X:
case llvm::ELF::R_HEX_11_X:
case llvm::ELF::R_HEX_10_X:
case llvm::ELF::R_HEX_9_X:
case llvm::ELF::R_HEX_8_X:
case llvm::ELF::R_HEX_7_X:
case llvm::ELF::R_HEX_6_X:
assert(!(rsym->reserved() & ReserveRel) &&
"Cannot apply this relocation for read only section");
return;
case llvm::ELF::R_HEX_32:
if (ld_backend.symbolNeedsPLT(*rsym)) {
// create PLT for this symbol if it does not have.
if (!(rsym->reserved() & ReservePLT)) {
helper_PLT_init(pReloc, *this);
rsym->setReserved(rsym->reserved() | ReservePLT);
}
}
if (ld_backend.symbolNeedsDynRel(
*rsym, (rsym->reserved() & ReservePLT), true)) {
if (ld_backend.symbolNeedsCopyReloc(pReloc, *rsym)) {
LDSymbol& cpy_sym =
defineSymbolforCopyReloc(pBuilder, *rsym, ld_backend);
addCopyReloc(*cpy_sym.resolveInfo(), ld_backend);
} else {
Relocation& reloc = helper_DynRel_init(rsym,
*pReloc.targetRef().frag(),
pReloc.targetRef().offset(),
llvm::ELF::R_HEX_RELATIVE,
*this);
// we need to set up the relocation addend at apply relocation, record
// the
// relocation
getRelRelMap().record(pReloc, reloc);
rsym->setReserved(rsym->reserved() | ReserveRel);
ld_backend.checkAndSetHasTextRel(*pSection.getLink());
}
}
return;
case llvm::ELF::R_HEX_GOTREL_LO16:
case llvm::ELF::R_HEX_GOTREL_HI16:
case llvm::ELF::R_HEX_GOTREL_32:
case llvm::ELF::R_HEX_GOTREL_32_6_X:
case llvm::ELF::R_HEX_GOTREL_16_X:
case llvm::ELF::R_HEX_GOTREL_11_X:
// This assumes that GOT exists
return;
case llvm::ELF::R_HEX_GOT_LO16:
case llvm::ELF::R_HEX_GOT_HI16:
case llvm::ELF::R_HEX_GOT_32:
case llvm::ELF::R_HEX_GOT_16:
case llvm::ELF::R_HEX_GOT_32_6_X:
case llvm::ELF::R_HEX_GOT_16_X:
case llvm::ELF::R_HEX_GOT_11_X:
// Symbol needs GOT entry, reserve entry in .got
// return if we already create GOT for this symbol
if (rsym->reserved() & ReserveGOT)
return;
// If the GOT is used in statically linked binaries,
// the GOT entry is enough and no relocation is needed.
if (config().isCodeStatic())
helper_GOT_init(pReloc, false, *this);
else
helper_GOT_init(pReloc, true, *this);
// set GOT bit
rsym->setReserved(rsym->reserved() | ReserveGOT);
return;
case llvm::ELF::R_HEX_B22_PCREL:
case llvm::ELF::R_HEX_B15_PCREL:
case llvm::ELF::R_HEX_B7_PCREL:
case llvm::ELF::R_HEX_B13_PCREL:
case llvm::ELF::R_HEX_B9_PCREL:
case llvm::ELF::R_HEX_B32_PCREL_X:
case llvm::ELF::R_HEX_B22_PCREL_X:
case llvm::ELF::R_HEX_B15_PCREL_X:
case llvm::ELF::R_HEX_B13_PCREL_X:
case llvm::ELF::R_HEX_B9_PCREL_X:
case llvm::ELF::R_HEX_B7_PCREL_X:
case llvm::ELF::R_HEX_32_PCREL:
case llvm::ELF::R_HEX_6_PCREL_X:
case llvm::ELF::R_HEX_PLT_B22_PCREL:
if (rsym->reserved() & ReservePLT)
return;
if (ld_backend.symbolNeedsPLT(*rsym) ||
pReloc.type() == llvm::ELF::R_HEX_PLT_B22_PCREL) {
helper_PLT_init(pReloc, *this);
rsym->setReserved(rsym->reserved() | ReservePLT);
}
return;
default:
break;
} // end of switch
}
