static bool canUseLocalRelocation(const MCSectionMachO &Section,
const MCSymbol &Symbol, unsigned Log2Size) {
// Debug info sections can use local relocations.
if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
return true;
// Otherwise, only pointer sized relocations are supported.
if (Log2Size != 3)
return false;
// But only if they don't point to a few forbidden sections.
if (!Symbol.isInSection())
return true;
const MCSectionMachO &RefSec = cast<MCSectionMachO>(Symbol.getSection());
if (RefSec.getType() == MachO::S_CSTRING_LITERALS)
return false;
if (RefSec.getSegmentName() == "__DATA" &&
RefSec.getSectionName() == "__cfstring")
return false;
if (RefSec.getSegmentName() == "__DATA" &&
RefSec.getSectionName() == "__objc_classrefs")
return false;
return true;
}
static bool canUseLocalRelocation(const MCSectionMachO &Section,
const MCSymbol &Symbol, unsigned Log2Size) {
// Debug info sections can use local relocations.
if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
return true;
// Otherwise, only pointer sized relocations are supported.
if (Log2Size != 3)
return false;
// But only if they don't point to a few forbidden sections.
if (!Symbol.isInSection())
return true;
const MCSectionMachO &RefSec = cast<MCSectionMachO>(Symbol.getSection());
if (RefSec.getType() == MachO::S_CSTRING_LITERALS)
return false;
if (RefSec.getSegmentName() == "__DATA" &&
RefSec.getSectionName() == "__objc_classrefs")
return false;
// FIXME: ld64 currently handles internal pointer-sized relocations
// incorrectly (applying the addend twice). We should be able to return true
// unconditionally by this point when that's fixed.
return false;
}
MCSymbol *MCStreamer::endSection(MCSection *Section) {
// TODO: keep track of the last subsection so that this symbol appears in the
// correct place.
MCSymbol *Sym = Section->getEndSymbol(Context);
if (Sym->isInSection())
return Sym;
SwitchSection(Section);
EmitLabel(Sym);
return Sym;
}
bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
// Non-temporary labels should always be visible to the linker.
if (!Symbol.isTemporary())
return true;
// Absolute temporary labels are never visible.
if (!Symbol.isInSection())
return false;
// Otherwise, check if the section requires symbols even for temporary labels.
return getBackend().doesSectionRequireSymbols(Symbol.getSection());
}
void MCStreamer::SwitchSection(MCSection *Section, const MCExpr *Subsection) {
assert(Section && "Cannot switch to a null section!");
MCSectionSubPair curSection = SectionStack.back().first;
SectionStack.back().second = curSection;
if (MCSectionSubPair(Section, Subsection) != curSection) {
ChangeSection(Section, Subsection);
SectionStack.back().first = MCSectionSubPair(Section, Subsection);
assert(!Section->hasEnded() && "Section already ended");
MCSymbol *Sym = Section->getBeginSymbol();
if (Sym && !Sym->isInSection())
EmitLabel(Sym);
}
}
bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
// Non-temporary labels should always be visible to the linker.
if (!Symbol.isTemporary())
return true;
// Absolute temporary labels are never visible.
if (!Symbol.isInSection())
return false;
if (Symbol.isUsedInReloc())
return true;
return false;
}
void BTFDebug::beginFunctionImpl(const MachineFunction *MF) {
auto *SP = MF->getFunction().getSubprogram();
auto *Unit = SP->getUnit();
if (Unit->getEmissionKind() == DICompileUnit::NoDebug) {
SkipInstruction = true;
return;
}
SkipInstruction = false;
// Collect all types locally referenced in this function.
// Use RetainedNodes so we can collect all argument names
// even if the argument is not used.
std::unordered_map<uint32_t, StringRef> FuncArgNames;
for (const DINode *DN : SP->getRetainedNodes()) {
if (const auto *DV = dyn_cast<DILocalVariable>(DN)) {
visitTypeEntry(DV->getType().resolve());
// Collect function arguments for subprogram func type.
uint32_t Arg = DV->getArg();
if (Arg)
FuncArgNames[Arg] = DV->getName();
}
}
// Construct subprogram func proto type.
uint32_t ProtoTypeId;
visitSubroutineType(SP->getType(), true, FuncArgNames, ProtoTypeId);
// Construct subprogram func type
auto FuncTypeEntry =
llvm::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId);
uint32_t FuncTypeId = addType(std::move(FuncTypeEntry));
// Construct funcinfo and the first lineinfo for the function.
MCSymbol *FuncLabel = Asm->getFunctionBegin();
BTFFuncInfo FuncInfo;
FuncInfo.Label = FuncLabel;
FuncInfo.TypeId = FuncTypeId;
if (FuncLabel->isInSection()) {
MCSection &Section = FuncLabel->getSection();
const MCSectionELF *SectionELF = dyn_cast<MCSectionELF>(&Section);
assert(SectionELF && "Null section for Function Label");
SecNameOff = addString(SectionELF->getSectionName());
} else {
SecNameOff = addString(".text");
}
FuncInfoTable[SecNameOff].push_back(FuncInfo);
}