void CodeGenModule::EmitVTableBitSetEntries(llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
if (!LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
!LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
!LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
!LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast))
return;
CharUnits PointerWidth =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
typedef std::pair<const CXXRecordDecl *, unsigned> BSEntry;
std::vector<BSEntry> BitsetEntries;
// Create a bit set entry for each address point.
for (auto &&AP : VTLayout.getAddressPoints()) {
if (IsCFIBlacklistedRecord(AP.first.getBase()))
continue;
BitsetEntries.push_back(std::make_pair(AP.first.getBase(), AP.second));
}
// Sort the bit set entries for determinism.
std::sort(BitsetEntries.begin(), BitsetEntries.end(),
[this](const BSEntry &E1, const BSEntry &E2) {
if (&E1 == &E2)
return false;
std::string S1;
llvm::raw_string_ostream O1(S1);
getCXXABI().getMangleContext().mangleTypeName(
QualType(E1.first->getTypeForDecl(), 0), O1);
O1.flush();
std::string S2;
llvm::raw_string_ostream O2(S2);
getCXXABI().getMangleContext().mangleTypeName(
QualType(E2.first->getTypeForDecl(), 0), O2);
O2.flush();
if (S1 < S2)
return true;
if (S1 != S2)
return false;
return E1.second < E2.second;
});
llvm::NamedMDNode *BitsetsMD =
getModule().getOrInsertNamedMetadata("llvm.bitsets");
for (auto BitsetEntry : BitsetEntries)
CreateVTableBitSetEntry(BitsetsMD, VTable,
PointerWidth * BitsetEntry.second,
BitsetEntry.first);
}
void CodeGenModule::EmitVTableTypeMetadata(llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
if (!getCodeGenOpts().LTOUnit)
return;
CharUnits PointerWidth =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
typedef std::pair<const CXXRecordDecl *, unsigned> BSEntry;
std::vector<BSEntry> BitsetEntries;
// Create a bit set entry for each address point.
for (auto &&AP : VTLayout.getAddressPoints())
BitsetEntries.push_back(
std::make_pair(AP.first.getBase(),
VTLayout.getVTableOffset(AP.second.VTableIndex) +
AP.second.AddressPointIndex));
// Sort the bit set entries for determinism.
std::sort(BitsetEntries.begin(), BitsetEntries.end(),
[this](const BSEntry &E1, const BSEntry &E2) {
if (&E1 == &E2)
return false;
std::string S1;
llvm::raw_string_ostream O1(S1);
getCXXABI().getMangleContext().mangleTypeName(
QualType(E1.first->getTypeForDecl(), 0), O1);
O1.flush();
std::string S2;
llvm::raw_string_ostream O2(S2);
getCXXABI().getMangleContext().mangleTypeName(
QualType(E2.first->getTypeForDecl(), 0), O2);
O2.flush();
if (S1 < S2)
return true;
if (S1 != S2)
return false;
return E1.second < E2.second;
});
for (auto BitsetEntry : BitsetEntries)
AddVTableTypeMetadata(VTable, PointerWidth * BitsetEntry.second,
BitsetEntry.first);
}
void CodeGenModule::EmitVTableTypeMetadata(llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
if (!getCodeGenOpts().LTOUnit)
return;
CharUnits PointerWidth =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
typedef std::pair<const CXXRecordDecl *, unsigned> AddressPoint;
std::vector<AddressPoint> AddressPoints;
for (auto &&AP : VTLayout.getAddressPoints())
AddressPoints.push_back(std::make_pair(
AP.first.getBase(), VTLayout.getVTableOffset(AP.second.VTableIndex) +
AP.second.AddressPointIndex));
// Sort the address points for determinism.
llvm::sort(AddressPoints, [this](const AddressPoint &AP1,
const AddressPoint &AP2) {
if (&AP1 == &AP2)
return false;
std::string S1;
llvm::raw_string_ostream O1(S1);
getCXXABI().getMangleContext().mangleTypeName(
QualType(AP1.first->getTypeForDecl(), 0), O1);
O1.flush();
std::string S2;
llvm::raw_string_ostream O2(S2);
getCXXABI().getMangleContext().mangleTypeName(
QualType(AP2.first->getTypeForDecl(), 0), O2);
O2.flush();
if (S1 < S2)
return true;
if (S1 != S2)
return false;
return AP1.second < AP2.second;
});
ArrayRef<VTableComponent> Comps = VTLayout.vtable_components();
for (auto AP : AddressPoints) {
// Create type metadata for the address point.
AddVTableTypeMetadata(VTable, PointerWidth * AP.second, AP.first);
// The class associated with each address point could also potentially be
// used for indirect calls via a member function pointer, so we need to
// annotate the address of each function pointer with the appropriate member
// function pointer type.
for (unsigned I = 0; I != Comps.size(); ++I) {
if (Comps[I].getKind() != VTableComponent::CK_FunctionPointer)
continue;
llvm::Metadata *MD = CreateMetadataIdentifierForVirtualMemPtrType(
Context.getMemberPointerType(
Comps[I].getFunctionDecl()->getType(),
Context.getRecordType(AP.first).getTypePtr()));
VTable->addTypeMetadata((PointerWidth * I).getQuantity(), MD);
}
}
}
void CodeGenModule::EmitVTableBitSetEntries(llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
if (!LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
!LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
!LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
!LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast))
return;
llvm::Metadata *VTableMD = llvm::ConstantAsMetadata::get(VTable);
std::vector<llvm::MDTuple *> BitsetEntries;
// Create a bit set entry for each address point.
for (auto &&AP : VTLayout.getAddressPoints()) {
// FIXME: Add blacklisting scheme.
if (AP.first.getBase()->isInStdNamespace())
continue;
std::string OutName;
llvm::raw_string_ostream Out(OutName);
getCXXABI().getMangleContext().mangleCXXVTableBitSet(AP.first.getBase(),
Out);
CharUnits PointerWidth =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
uint64_t AddrPointOffset = AP.second * PointerWidth.getQuantity();
llvm::Metadata *BitsetOps[] = {
llvm::MDString::get(getLLVMContext(), Out.str()),
VTableMD,
llvm::ConstantAsMetadata::get(
llvm::ConstantInt::get(Int64Ty, AddrPointOffset))};
llvm::MDTuple *BitsetEntry =
llvm::MDTuple::get(getLLVMContext(), BitsetOps);
BitsetEntries.push_back(BitsetEntry);
}
// Sort the bit set entries for determinism.
std::sort(BitsetEntries.begin(), BitsetEntries.end(), [](llvm::MDTuple *T1,
llvm::MDTuple *T2) {
if (T1 == T2)
return false;
StringRef S1 = cast<llvm::MDString>(T1->getOperand(0))->getString();
StringRef S2 = cast<llvm::MDString>(T2->getOperand(0))->getString();
if (S1 < S2)
return true;
if (S1 != S2)
return false;
uint64_t Offset1 = cast<llvm::ConstantInt>(
cast<llvm::ConstantAsMetadata>(T1->getOperand(2))
->getValue())->getZExtValue();
uint64_t Offset2 = cast<llvm::ConstantInt>(
cast<llvm::ConstantAsMetadata>(T2->getOperand(2))
->getValue())->getZExtValue();
assert(Offset1 != Offset2);
return Offset1 < Offset2;
});
llvm::NamedMDNode *BitsetsMD =
getModule().getOrInsertNamedMetadata("llvm.bitsets");
for (auto BitsetEntry : BitsetEntries)
BitsetsMD->addOperand(BitsetEntry);
}