void IdenticalCodeFolding::findCandidates(FoldingCandidates& pCandidateList) {
Module::obj_iterator obj, objEnd = m_Module.obj_end();
for (obj = m_Module.obj_begin(); obj != objEnd; ++obj) {
std::set<const LDSection*> funcptr_access_set;
typedef std::map<LDSection*, LDSection*> CandidateMap;
CandidateMap candidate_map;
LDContext::sect_iterator sect, sectEnd = (*obj)->context()->sectEnd();
for (sect = (*obj)->context()->sectBegin(); sect != sectEnd; ++sect) {
switch ((*sect)->kind()) {
case LDFileFormat::TEXT: {
candidate_map.insert(
std::make_pair(*sect, reinterpret_cast<LDSection*>(NULL)));
break;
}
case LDFileFormat::Relocation: {
LDSection* target = (*sect)->getLink();
if (target->kind() == LDFileFormat::TEXT) {
candidate_map[target] = *sect;
}
// Safe icf
if (m_Config.options().getICFMode() == GeneralOptions::ICF::Safe) {
RelocData::iterator rel, relEnd = (*sect)->getRelocData()->end();
for (rel = (*sect)->getRelocData()->begin(); rel != relEnd; ++rel) {
LDSymbol* sym = rel->symInfo()->outSymbol();
if (sym->hasFragRef() && (sym->type() == ResolveInfo::Function)) {
const LDSection* def =
&sym->fragRef()->frag()->getParent()->getSection();
if (!isSymCtorOrDtor(*rel->symInfo()) &&
m_Backend.mayHaveUnsafeFunctionPointerAccess(*target) &&
m_Backend.getRelocator()
->mayHaveFunctionPointerAccess(*rel)) {
funcptr_access_set.insert(def);
}
}
} // for each reloc
}
break;
}
default: {
// skip
break;
}
} // end of switch
} // for each section
CandidateMap::iterator candidate, candidateEnd = candidate_map.end();
for (candidate = candidate_map.begin(); candidate != candidateEnd;
++candidate) {
if ((m_Config.options().getICFMode() == GeneralOptions::ICF::All) ||
(funcptr_access_set.count(candidate->first) == 0)) {
size_t index = m_KeptSections.size();
m_KeptSections[candidate->first] = ObjectAndId(*obj, index);
pCandidateList.push_back(
FoldingCandidate(candidate->first, candidate->second, *obj));
}
} // for each possible candidate
} // for each obj
}
void IdenticalCodeFolding::FoldingCandidate::initConstantContent(
const TargetLDBackend& pBackend,
const IdenticalCodeFolding::KeptSections& pKeptSections) {
// Get the static content from text.
assert(sect != NULL && sect->hasSectionData());
SectionData::const_iterator frag, fragEnd = sect->getSectionData()->end();
for (frag = sect->getSectionData()->begin(); frag != fragEnd; ++frag) {
switch (frag->getKind()) {
case Fragment::Region: {
const RegionFragment& region = llvm::cast<RegionFragment>(*frag);
content.append(region.getRegion().begin(), region.size());
break;
}
default: {
// FIXME: Currently we only take care of RegionFragment.
break;
}
}
}
// Get the static content from relocs.
if (reloc_sect != NULL && reloc_sect->hasRelocData()) {
for (Relocation& rel : *reloc_sect->getRelocData()) {
llvm::format_object<Relocation::Type,
Relocation::Address,
Relocation::Address,
Relocation::Address> rel_info("%x%llx%llx%llx",
rel.type(),
rel.symValue(),
rel.addend(),
rel.place());
char rel_str[48];
rel_info.print(rel_str, sizeof(rel_str));
content.append(rel_str);
// Handle the recursive call.
LDSymbol* sym = rel.symInfo()->outSymbol();
if ((sym->type() == ResolveInfo::Function) && sym->hasFragRef()) {
LDSection* def = &sym->fragRef()->frag()->getParent()->getSection();
if (def == sect) {
continue;
}
}
if (!pBackend.isSymbolPreemptible(*rel.symInfo()) && sym->hasFragRef() &&
(pKeptSections.find(
&sym->fragRef()->frag()->getParent()->getSection()) !=
pKeptSections.end())) {
// Mark this reloc as a variable.
variable_relocs.push_back(&rel);
} else {
// TODO: Support inlining merge sections if possible (target-dependent).
if ((sym->binding() == ResolveInfo::Local) ||
(sym->binding() == ResolveInfo::Absolute)) {
// ABS or Local symbols.
content.append(sym->name()).append(obj->name()).append(
obj->path().native());
} else {
content.append(sym->name());
}
}
}
}
}
bool MipsGNULDBackend::hasEntryInStrTab(const LDSymbol& pSym) const {
return ResolveInfo::Section != pSym.type() || m_pGpDispSymbol == &pSym;
}
