inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
unsigned Type,
unsigned Flags,
SectionKind Kind,
const MCSymbol &Fn) {
const MCSectionELF &FnSection =
static_cast<const MCSectionELF &>(Fn.getSection());
// Create the name for new section
StringRef FnSecName(FnSection.getSectionName());
SmallString<128> EHSecName(Prefix);
if (FnSecName != ".text") {
EHSecName += FnSecName;
}
// Get .ARM.extab or .ARM.exidx section
const MCSectionELF *EHSection = NULL;
if (const MCSymbol *Group = FnSection.getGroup()) {
EHSection = getContext().getELFSection(
EHSecName, Type, Flags | ELF::SHF_GROUP, Kind,
FnSection.getEntrySize(), Group->getName());
} else {
EHSection = getContext().getELFSection(EHSecName, Type, Flags, Kind);
}
assert(EHSection);
// Switch to .ARM.extab or .ARM.exidx section
SwitchSection(EHSection);
EmitCodeAlignment(4, 0);
}
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;
}
bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
bool InSet, bool IsPCRel) const {
const MCSection &SecA = SymA.getSection();
const MCSection &SecB = *FB.getParent();
// On ELF and COFF A - B is absolute if A and B are in the same section.
return &SecA == &SecB;
}
/// EmitValue - Emit label value.
///
void DIELocList::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
DwarfDebug *DD = AP->getDwarfDebug();
MCSymbol *Label = DD->getDebugLocEntries()[Index].Label;
if (AP->MAI->doesDwarfUseRelocationsAcrossSections() && !DD->useSplitDwarf())
AP->emitSectionOffset(Label);
else
AP->EmitLabelDifference(Label, Label->getSection().getBeginSymbol(), 4);
}
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 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);
}