bool HexagonLDBackend::SetSDataSection() {
SectionData *pTo = (m_psdata->getSectionData());
if (pTo) {
MoveCommonData(*m_pscommon_1->getSectionData(), *pTo);
MoveCommonData(*m_pscommon_2->getSectionData(), *pTo);
MoveCommonData(*m_pscommon_4->getSectionData(), *pTo);
MoveCommonData(*m_pscommon_8->getSectionData(), *pTo);
SectionData::FragmentListType& to_list = pTo->getFragmentList();
SectionData::FragmentListType::iterator fragTo, fragToEnd = to_list.end();
uint32_t offset = 0;
for (fragTo = to_list.begin(); fragTo != fragToEnd; ++fragTo) {
fragTo->setOffset(offset);
offset += fragTo->size();
}
// set up pTo's header
pTo->getSection().setSize(offset);
SectionData::FragmentListType& newlist = pTo->getFragmentList();
for (fragTo = newlist.begin(), fragToEnd = newlist.end();
fragTo != fragToEnd; ++fragTo) {
fragTo->setParent(pTo);
}
}
return true;
}
/// addStub - add a stub into the island
bool BranchIsland::addStub(const Stub* pPrototype,
const Relocation& pReloc,
Stub& pStub)
{
bool exist = false;
Key key(pPrototype, pReloc.symInfo()->outSymbol(), pReloc.addend());
StubEntryType* entry = m_StubMap.insert(key, exist);
if (!exist) {
entry->setValue(&pStub);
m_pRear = &pStub;
SectionData* sd = m_Entry.getParent();
// insert alignment fragment
// TODO: check if we can reduce this alignment fragment for some cases
AlignFragment* align_frag = new AlignFragment(pStub.alignment(),
0x0,
1u,
pStub.alignment() - 1);
align_frag->setParent(sd);
sd->getFragmentList().insert(end(), align_frag);
align_frag->setOffset(align_frag->getPrevNode()->getOffset() +
align_frag->getPrevNode()->size());
// insert stub fragment
pStub.setParent(sd);
sd->getFragmentList().insert(end(), &pStub);
pStub.setOffset(pStub.getPrevNode()->getOffset() +
pStub.getPrevNode()->size());
}
return !exist;
}
/// MoveSectionData - move the fragments of pTO section data to pTo
bool HexagonLDBackend::MoveSectionDataAndSort(SectionData& pFrom, SectionData& pTo)
{
assert(&pFrom != &pTo && "Cannot move section data to itself!");
SectionData::FragmentListType& to_list = pTo.getFragmentList();
SectionData::FragmentListType::iterator frag, fragEnd = to_list.end();
uint32_t pFromFlag = pFrom.getSection().align();
bool found = false;
SectionData::FragmentListType::iterator fragInsert;
for (frag = to_list.begin(); frag != fragEnd; ++frag) {
if (frag->getKind() == mcld::Fragment::Alignment) {
fragInsert = frag;
continue;
}
if ((frag->getKind() != mcld::Fragment::Region) &&
(frag->getKind() != mcld::Fragment::Fillment)) {
continue;
}
uint32_t flag = frag->getParent()->getSection().align();
if (pFromFlag < flag) {
found = true;
break;
}
}
AlignFragment* align = NULL;
if (pFrom.getSection().align() > 1) {
// if the align constraint is larger than 1, append an alignment
align = new AlignFragment(pFrom.getSection().align(), // alignment
0x0, // the filled value
1u, // the size of filled value
pFrom.getSection().align() - 1 // max bytes to emit
);
pFrom.getFragmentList().push_front(align);
}
if (found)
to_list.splice(fragInsert, pFrom.getFragmentList());
else
to_list.splice(frag, pFrom.getFragmentList());
uint32_t offset = 0;
for (frag = to_list.begin(); frag != fragEnd; ++frag) {
frag->setOffset(offset);
offset += frag->size();
}
// set up pTo's header
pTo.getSection().setSize(offset);
if (pFrom.getSection().align() > pTo.getSection().align())
pTo.getSection().setAlign(pFrom.getSection().align());
if (pFrom.getSection().flag() > pTo.getSection().flag())
pTo.getSection().setFlag(pFrom.getSection().flag());
return true;
}
bool HexagonLDBackend::MoveCommonData(SectionData &pFrom, SectionData &pTo)
{
SectionData::FragmentListType& to_list = pTo.getFragmentList();
SectionData::FragmentListType::iterator frag, fragEnd = to_list.end();
uint32_t pFromFlag = pFrom.getSection().align();
bool found = false;
SectionData::FragmentListType::iterator fragInsert;
for (frag = to_list.begin(); frag != fragEnd; ++frag) {
if (frag->getKind() == mcld::Fragment::Alignment) {
fragInsert = frag;
continue;
}
if ((frag->getKind() != mcld::Fragment::Region) &&
(frag->getKind() != mcld::Fragment::Fillment)) {
continue;
}
uint32_t flag = frag->getParent()->getSection().align();
if (pFromFlag < flag) {
found = true;
break;
}
}
AlignFragment* align = NULL;
if (pFrom.getSection().align() > 1) {
// if the align constraint is larger than 1, append an alignment
align = new AlignFragment(pFrom.getSection().align(), // alignment
0x0, // the filled value
1u, // the size of filled value
pFrom.getSection().align() - 1 // max bytes to emit
);
pFrom.getFragmentList().push_front(align);
}
if (found)
to_list.splice(fragInsert, pFrom.getFragmentList());
else
to_list.splice(frag, pFrom.getFragmentList());
return true;
}
void ARMGNULDBackend::rewriteARMExIdxSection(Module& pModule) {
if (!m_pEXIDX->hasSectionData()) {
// Return if this is empty section.
return;
}
SectionData* sectData = m_pEXIDX->getSectionData();
SectionData::FragmentListType& list = sectData->getFragmentList();
// Move the first fragment (align fragment) and last fragment (null fragment)
// to temporary list because we would only like to sort the region fragment.
SectionData::FragmentListType tmp;
{
SectionData::iterator first = sectData->begin();
SectionData::iterator last = sectData->end();
--last;
assert(first->getKind() == Fragment::Alignment);
assert(last->getKind() == Fragment::Null);
tmp.splice(tmp.end(), list, first);
tmp.splice(tmp.end(), list, last);
}
// Sort the region fragments in the .ARM.exidx output section.
sort(list, ExIdxFragmentComparator(m_ExData));
// Fix the coverage of the .ARM.exidx table.
llvm::StringRef cantUnwindRegion(g_CantUnwindEntry,
sizeof(g_CantUnwindEntry));
SectionData::FragmentListType::iterator it = list.begin();
if (it != list.end()) {
Fragment* prevTextFrag = m_ExData.getTupleByExIdx(it)->getTextFragment();
uint64_t prevTextEnd = prevTextFrag->getParent()->getSection().addr() +
prevTextFrag->getOffset() +
prevTextFrag->size();
++it;
while (it != list.end()) {
Fragment* currTextFrag = m_ExData.getTupleByExIdx(it)->getTextFragment();
uint64_t currTextBegin = currTextFrag->getParent()->getSection().addr() +
currTextFrag->getOffset();
if (currTextBegin > prevTextEnd) {
// Found a gap. Insert a can't unwind entry.
RegionFragment* frag = new RegionFragment(cantUnwindRegion, nullptr);
frag->setParent(sectData);
list.insert(it, frag);
// Add PREL31 reference to the beginning of the uncovered region.
Relocation* reloc =
Relocation::Create(static_cast<uint32_t>(llvm::ELF::R_ARM_PREL31),
*FragmentRef::Create(*frag, /* pOffset */0),
/* pAddend */0);
reloc->setSymInfo(
CreateLocalSymbolToFragmentEnd(pModule, *prevTextFrag));
addExtraRelocation(reloc);
}
prevTextEnd = currTextBegin + currTextFrag->size();
prevTextFrag = currTextFrag;
++it;
}
// Add a can't unwind entry to terminate .ARM.exidx section.
RegionFragment* frag = new RegionFragment(cantUnwindRegion, nullptr);
frag->setParent(sectData);
list.push_back(frag);
// Add PREL31 reference to the end of the .text section.
Relocation* reloc =
Relocation::Create(static_cast<uint32_t>(llvm::ELF::R_ARM_PREL31),
*FragmentRef::Create(*frag, /* pOffset */0),
/* pAddend */0);
reloc->setSymInfo(CreateLocalSymbolToFragmentEnd(pModule, *prevTextFrag));
addExtraRelocation(reloc);
}
// Add the first and the last fragment back.
list.splice(list.begin(), tmp, tmp.begin());
list.splice(list.end(), tmp, tmp.begin());
// Update the fragment offsets.
uint64_t offset = 0;
for (SectionData::iterator it = sectData->begin(), end = sectData->end();
it != end; ++it) {
it->setOffset(offset);
offset += it->size();
}
// Update the section size.
m_pEXIDX->setSize(offset);
// Rebuild the section header.
setOutputSectionAddress(pModule);
}