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Add deactivation symbol operand to ConstantPtrAuth. #133537

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[𝘀𝗽𝗿] initial version
pcc Mar 28, 2025
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pcc May 13, 2025
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pcc May 24, 2025
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Add verifier check
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pcc Sep 10, 2025
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6 changes: 3 additions & 3 deletions clang/lib/CodeGen/CGPointerAuth.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -440,9 +440,9 @@ CodeGenModule::getConstantSignedPointer(llvm::Constant *Pointer, unsigned Key,
IntegerDiscriminator = llvm::ConstantInt::get(Int64Ty, 0);
}

return llvm::ConstantPtrAuth::get(Pointer,
llvm::ConstantInt::get(Int32Ty, Key),
IntegerDiscriminator, AddressDiscriminator);
return llvm::ConstantPtrAuth::get(
Pointer, llvm::ConstantInt::get(Int32Ty, Key), IntegerDiscriminator,
AddressDiscriminator, llvm::Constant::getNullValue(UnqualPtrTy));
}

/// Does a given PointerAuthScheme require us to sign a value
Expand Down
2 changes: 2 additions & 0 deletions llvm/include/llvm/Bitcode/LLVMBitCodes.h
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Expand Up @@ -437,6 +437,8 @@ enum ConstantsCodes {
CST_CODE_CE_GEP_WITH_INRANGE = 31, // [opty, flags, range, n x operands]
CST_CODE_CE_GEP = 32, // [opty, flags, n x operands]
CST_CODE_PTRAUTH = 33, // [ptr, key, disc, addrdisc]
CST_CODE_PTRAUTH2 = 34, // [ptr, key, disc, addrdisc,
// deactivation_symbol]
};

/// CastOpcodes - These are values used in the bitcode files to encode which
Expand Down
13 changes: 9 additions & 4 deletions llvm/include/llvm/IR/Constants.h
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Expand Up @@ -1033,10 +1033,10 @@ class ConstantPtrAuth final : public Constant {
friend struct ConstantPtrAuthKeyType;
friend class Constant;

constexpr static IntrusiveOperandsAllocMarker AllocMarker{4};
constexpr static IntrusiveOperandsAllocMarker AllocMarker{5};

ConstantPtrAuth(Constant *Ptr, ConstantInt *Key, ConstantInt *Disc,
Constant *AddrDisc);
Constant *AddrDisc, Constant *DeactivationSymbol);

void *operator new(size_t s) { return User::operator new(s, AllocMarker); }

Expand All @@ -1046,7 +1046,8 @@ class ConstantPtrAuth final : public Constant {
public:
/// Return a pointer signed with the specified parameters.
LLVM_ABI static ConstantPtrAuth *get(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc);
ConstantInt *Disc, Constant *AddrDisc,
Constant *DeactivationSymbol);
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@ahmedbougacha ahmedbougacha Sep 12, 2025

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You don't have to do this here, but we probably should make the optional operands (in textual IR) optional here as well, and implicitly make them null? Now that I think about it, I'm not sure how idiomatic that would be

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@pcc pcc Sep 12, 2025

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I considered it, but since there are only a few places that need this, it seemed slightly better to be explicit about all the operands since that's consistent with what we have elsewhere.

What might be nice is if we initialized this using fields of a passed-in struct so that call sites are more readable, but that's a separate change.


/// Produce a new ptrauth expression signing the given value using
/// the same schema as is stored in one.
Expand Down Expand Up @@ -1078,6 +1079,10 @@ class ConstantPtrAuth final : public Constant {
return !getAddrDiscriminator()->isNullValue();
}

Constant *getDeactivationSymbol() const {
return cast<Constant>(Op<4>().get());
}

/// A constant value for the address discriminator which has special
/// significance to ctors/dtors lowering. Regular address discrimination can't
/// be applied for them since uses of llvm.global_{c|d}tors are disallowed
Expand Down Expand Up @@ -1106,7 +1111,7 @@ class ConstantPtrAuth final : public Constant {

template <>
struct OperandTraits<ConstantPtrAuth>
: public FixedNumOperandTraits<ConstantPtrAuth, 4> {};
: public FixedNumOperandTraits<ConstantPtrAuth, 5> {};

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPtrAuth, Constant)

Expand Down
5 changes: 4 additions & 1 deletion llvm/include/llvm/SandboxIR/Constant.h
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Expand Up @@ -1363,7 +1363,8 @@ class ConstantPtrAuth final : public Constant {
public:
/// Return a pointer signed with the specified parameters.
LLVM_ABI static ConstantPtrAuth *get(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc);
ConstantInt *Disc, Constant *AddrDisc,
Constant *DeactivationSymbol);
/// The pointer that is signed in this ptrauth signed pointer.
LLVM_ABI Constant *getPointer() const;

Expand All @@ -1378,6 +1379,8 @@ class ConstantPtrAuth final : public Constant {
/// the only global-initializer user of the ptrauth signed pointer.
LLVM_ABI Constant *getAddrDiscriminator() const;

Constant *getDeactivationSymbol() const;

/// Whether there is any non-null address discriminator.
bool hasAddressDiscriminator() const {
return cast<llvm::ConstantPtrAuth>(Val)->hasAddressDiscriminator();
Expand Down
29 changes: 21 additions & 8 deletions llvm/lib/AsmParser/LLParser.cpp
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Expand Up @@ -4216,11 +4216,12 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
}
case lltok::kw_ptrauth: {
// ValID ::= 'ptrauth' '(' ptr @foo ',' i32 <key>
// (',' i64 <disc> (',' ptr addrdisc)? )? ')'
// (',' i64 <disc> (',' ptr addrdisc (',' ptr ds)? )? )? ')'
Lex.Lex();

Constant *Ptr, *Key;
Constant *Disc = nullptr, *AddrDisc = nullptr;
Constant *Disc = nullptr, *AddrDisc = nullptr,
*DeactivationSymbol = nullptr;

if (parseToken(lltok::lparen,
"expected '(' in constant ptrauth expression") ||
Expand All @@ -4229,11 +4230,14 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
"expected comma in constant ptrauth expression") ||
parseGlobalTypeAndValue(Key))
return true;
// If present, parse the optional disc/addrdisc.
if (EatIfPresent(lltok::comma))
if (parseGlobalTypeAndValue(Disc) ||
(EatIfPresent(lltok::comma) && parseGlobalTypeAndValue(AddrDisc)))
return true;
// If present, parse the optional disc/addrdisc/ds.
if (EatIfPresent(lltok::comma) && parseGlobalTypeAndValue(Disc))
return true;
if (EatIfPresent(lltok::comma) && parseGlobalTypeAndValue(AddrDisc))
return true;
if (EatIfPresent(lltok::comma) &&
parseGlobalTypeAndValue(DeactivationSymbol))
return true;
if (parseToken(lltok::rparen,
"expected ')' in constant ptrauth expression"))
return true;
Expand Down Expand Up @@ -4264,7 +4268,16 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
AddrDisc = ConstantPointerNull::get(PointerType::get(Context, 0));
}

ID.ConstantVal = ConstantPtrAuth::get(Ptr, KeyC, DiscC, AddrDisc);
if (DeactivationSymbol) {
if (!DeactivationSymbol->getType()->isPointerTy())
return error(
ID.Loc, "constant ptrauth deactivation symbol must be a pointer");
} else {
DeactivationSymbol = ConstantPointerNull::get(PointerType::get(Context, 0));
}

ID.ConstantVal =
ConstantPtrAuth::get(Ptr, KeyC, DiscC, AddrDisc, DeactivationSymbol);
ID.Kind = ValID::t_Constant;
return false;
}
Expand Down
18 changes: 17 additions & 1 deletion llvm/lib/Bitcode/Reader/BitcodeReader.cpp
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Expand Up @@ -1608,7 +1608,13 @@ Expected<Value *> BitcodeReader::materializeValue(unsigned StartValID,
if (!Disc)
return error("ptrauth disc operand must be ConstantInt");

C = ConstantPtrAuth::get(ConstOps[0], Key, Disc, ConstOps[3]);
auto *DeactivationSymbol =
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@ojhunt ojhunt Sep 11, 2025

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[nit] while there is a type named on the rhs, I think based on the ternary rather than single option, this should be Constant * instead of auto *

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@pcc pcc Sep 11, 2025

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Done

ConstOps.size() > 4 ? ConstOps[4]
: ConstantPointerNull::get(cast<PointerType>(
ConstOps[3]->getType()));

C = ConstantPtrAuth::get(ConstOps[0], Key, Disc, ConstOps[3],
DeactivationSymbol);
break;
}
case BitcodeConstant::NoCFIOpcode: {
Expand Down Expand Up @@ -3808,6 +3814,16 @@ Error BitcodeReader::parseConstants() {
(unsigned)Record[2], (unsigned)Record[3]});
break;
}
case bitc::CST_CODE_PTRAUTH2: {
if (Record.size() < 4)
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@ahmedbougacha ahmedbougacha Sep 12, 2025

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Should this be 5?

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@pcc pcc Sep 12, 2025

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Indeed, fixed

return error("Invalid ptrauth record");
// Ptr, Key, Disc, AddrDisc, DeactivationSymbol
V = BitcodeConstant::create(
Alloc, CurTy, BitcodeConstant::ConstantPtrAuthOpcode,
{(unsigned)Record[0], (unsigned)Record[1], (unsigned)Record[2],
(unsigned)Record[3], (unsigned)Record[4]});
break;
}
}

assert(V->getType() == getTypeByID(CurTyID) && "Incorrect result type ID");
Expand Down
3 changes: 2 additions & 1 deletion llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
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Expand Up @@ -3010,11 +3010,12 @@ void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
Record.push_back(VE.getValueID(NC->getGlobalValue()));
} else if (const auto *CPA = dyn_cast<ConstantPtrAuth>(C)) {
Code = bitc::CST_CODE_PTRAUTH;
Code = bitc::CST_CODE_PTRAUTH2;
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@ojhunt ojhunt Sep 11, 2025 •
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I think this should be

Constant *DeactivationSymbol = CPA->getDeactivationSymbol();
Code =  DeactivationSymbol->isNullValue() ? CST_CODE_PTRAUTH : CST_CODE_PTRAUTH2;
...
if (!DeactivationSymbol->isNullValue())
   Record.push_back(VE.getValueID(DeactivationSymbol));

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@ojhunt ojhunt Sep 11, 2025

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updated to correct the of the Code

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@pcc pcc Sep 11, 2025

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Bitcode doesn't have forwards compatibility, only backwards compatibility. So I think it's fine to use PTRAUTH2 unconditionally here.

Record.push_back(VE.getValueID(CPA->getPointer()));
Record.push_back(VE.getValueID(CPA->getKey()));
Record.push_back(VE.getValueID(CPA->getDiscriminator()));
Record.push_back(VE.getValueID(CPA->getAddrDiscriminator()));
Record.push_back(VE.getValueID(CPA->getDeactivationSymbol()));
} else {
#ifndef NDEBUG
C->dump();
Expand Down
4 changes: 3 additions & 1 deletion llvm/lib/IR/AsmWriter.cpp
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Expand Up @@ -1667,12 +1667,14 @@ static void WriteConstantInternal(raw_ostream &Out, const Constant *CV,
if (const ConstantPtrAuth *CPA = dyn_cast<ConstantPtrAuth>(CV)) {
Out << "ptrauth (";

// ptrauth (ptr CST, i32 KEY[, i64 DISC[, ptr ADDRDISC]?]?)
// ptrauth (ptr CST, i32 KEY[, i64 DISC[, ptr ADDRDISC[, ptr DS]?]?]?)
unsigned NumOpsToWrite = 2;
if (!CPA->getOperand(2)->isNullValue())
NumOpsToWrite = 3;
if (!CPA->getOperand(3)->isNullValue())
NumOpsToWrite = 4;
if (!CPA->getOperand(4)->isNullValue())
NumOpsToWrite = 5;

ListSeparator LS;
for (unsigned i = 0, e = NumOpsToWrite; i != e; ++i) {
Expand Down
12 changes: 8 additions & 4 deletions llvm/lib/IR/Constants.cpp
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Expand Up @@ -2060,19 +2060,22 @@ Value *NoCFIValue::handleOperandChangeImpl(Value *From, Value *To) {
//

ConstantPtrAuth *ConstantPtrAuth::get(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc) {
Constant *ArgVec[] = {Ptr, Key, Disc, AddrDisc};
ConstantInt *Disc, Constant *AddrDisc,
Constant *DeactivationSymbol) {
Constant *ArgVec[] = {Ptr, Key, Disc, AddrDisc, DeactivationSymbol};
ConstantPtrAuthKeyType MapKey(ArgVec);
LLVMContextImpl *pImpl = Ptr->getContext().pImpl;
return pImpl->ConstantPtrAuths.getOrCreate(Ptr->getType(), MapKey);
}

ConstantPtrAuth *ConstantPtrAuth::getWithSameSchema(Constant *Pointer) const {
return get(Pointer, getKey(), getDiscriminator(), getAddrDiscriminator());
return get(Pointer, getKey(), getDiscriminator(), getAddrDiscriminator(),
getDeactivationSymbol());
}

ConstantPtrAuth::ConstantPtrAuth(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc)
ConstantInt *Disc, Constant *AddrDisc,
Constant *DeactivationSymbol)
: Constant(Ptr->getType(), Value::ConstantPtrAuthVal, AllocMarker) {
assert(Ptr->getType()->isPointerTy());
assert(Key->getBitWidth() == 32);
Expand All @@ -2082,6 +2085,7 @@ ConstantPtrAuth::ConstantPtrAuth(Constant *Ptr, ConstantInt *Key,
setOperand(1, Key);
setOperand(2, Disc);
setOperand(3, AddrDisc);
setOperand(4, DeactivationSymbol);
}

/// Remove the constant from the constant table.
Expand Down
3 changes: 2 additions & 1 deletion llvm/lib/IR/ConstantsContext.h
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Expand Up @@ -539,7 +539,8 @@ struct ConstantPtrAuthKeyType {

ConstantPtrAuth *create(TypeClass *Ty) const {
return new ConstantPtrAuth(Operands[0], cast<ConstantInt>(Operands[1]),
cast<ConstantInt>(Operands[2]), Operands[3]);
cast<ConstantInt>(Operands[2]), Operands[3],
Operands[4]);
}
};

Expand Down
4 changes: 3 additions & 1 deletion llvm/lib/IR/Core.cpp
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Expand Up @@ -1699,7 +1699,9 @@ LLVMValueRef LLVMConstantPtrAuth(LLVMValueRef Ptr, LLVMValueRef Key,
LLVMValueRef Disc, LLVMValueRef AddrDisc) {
return wrap(ConstantPtrAuth::get(
unwrap<Constant>(Ptr), unwrap<ConstantInt>(Key),
unwrap<ConstantInt>(Disc), unwrap<Constant>(AddrDisc)));
unwrap<ConstantInt>(Disc), unwrap<Constant>(AddrDisc),
ConstantPointerNull::get(
cast<PointerType>(unwrap<Constant>(AddrDisc)->getType()))));
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@efriedma-quic efriedma-quic May 28, 2025

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Do we want to extend the C API to give access to this?

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@pcc pcc May 28, 2025

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I reckon that could be done in a followup if anyone needs it.

}

/*-- Opcode mapping */
Expand Down
5 changes: 5 additions & 0 deletions llvm/lib/IR/Verifier.cpp
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Expand Up @@ -2627,6 +2627,11 @@ void Verifier::visitConstantPtrAuth(const ConstantPtrAuth *CPA) {

Check(CPA->getDiscriminator()->getBitWidth() == 64,
"signed ptrauth constant discriminator must be i64 constant integer");

Check(isa<GlobalValue>(CPA->getDeactivationSymbol()) ||
CPA->getDeactivationSymbol()->isNullValue(),
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@efriedma-quic efriedma-quic Aug 4, 2025

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Maybe also check CPA->getDeactivationSymbol()->getType()->isPointerTy()?

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@pcc pcc Sep 9, 2025 •
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I think it's probably best to check that in the ConstantPtrAuth constructor; I've added a check for that there.

I had already added a check for this operand being a pointer in the .ll parser; I noticed that there was no test coverage for that so I added it.

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@efriedma-quic efriedma-quic Sep 9, 2025

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For things we can easily check in the verifier, I prefer to check them even if there's also an assertion, to catch issues in assert-disabled builds.

Also, missing check in the bitcode parser.

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@pcc pcc Sep 10, 2025

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For things we can easily check in the verifier, I prefer to check them even if there's also an assertion, to catch issues in assert-disabled builds.

Isn't the verifier disabled by default in no-asserts builds? So I guess it wouldn't make much of a difference.

llvm-project/clang/lib/Driver/ToolChains/Clang.cpp

Line 5459 in e320d9b

CmdArgs.push_back("-disable-llvm-verifier");

(Looks like the comments were meant to read "no-asserts", I sent #157769 for that.)

That being said I don't feel strongly so I added it.

Also, missing check in the bitcode parser.

Added.

"signed ptrauth constant deactivation symbol must be a global value "
"or null");
}

bool Verifier::verifyAttributeCount(AttributeList Attrs, unsigned Params) {
Expand Down
11 changes: 9 additions & 2 deletions llvm/lib/SandboxIR/Constant.cpp
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Expand Up @@ -412,10 +412,12 @@ PointerType *NoCFIValue::getType() const {
}

ConstantPtrAuth *ConstantPtrAuth::get(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc) {
ConstantInt *Disc, Constant *AddrDisc,
Constant *DeactivationSymbol) {
auto *LLVMC = llvm::ConstantPtrAuth::get(
cast<llvm::Constant>(Ptr->Val), cast<llvm::ConstantInt>(Key->Val),
cast<llvm::ConstantInt>(Disc->Val), cast<llvm::Constant>(AddrDisc->Val));
cast<llvm::ConstantInt>(Disc->Val), cast<llvm::Constant>(AddrDisc->Val),
cast<llvm::Constant>(DeactivationSymbol->Val));
return cast<ConstantPtrAuth>(Ptr->getContext().getOrCreateConstant(LLVMC));
}

Expand All @@ -439,6 +441,11 @@ Constant *ConstantPtrAuth::getAddrDiscriminator() const {
cast<llvm::ConstantPtrAuth>(Val)->getAddrDiscriminator());
}

Constant *ConstantPtrAuth::getDeactivationSymbol() const {
return Ctx.getOrCreateConstant(
cast<llvm::ConstantPtrAuth>(Val)->getDeactivationSymbol());
}

ConstantPtrAuth *ConstantPtrAuth::getWithSameSchema(Constant *Pointer) const {
auto *LLVMC = cast<llvm::ConstantPtrAuth>(Val)->getWithSameSchema(
cast<llvm::Constant>(Pointer->Val));
Expand Down
43 changes: 36 additions & 7 deletions llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
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Expand Up @@ -222,7 +222,7 @@ class AArch64AsmPrinter : public AsmPrinter {

const MCExpr *emitPAuthRelocationAsIRelative(
const MCExpr *Target, uint16_t Disc, AArch64PACKey::ID KeyID,
bool HasAddressDiversity, bool IsDSOLocal);
bool HasAddressDiversity, bool IsDSOLocal, const MCExpr *DSExpr);

/// tblgen'erated driver function for lowering simple MI->MC
/// pseudo instructions.
Expand Down Expand Up @@ -2343,15 +2343,17 @@ static void emitAddress(MCStreamer &Streamer, MCRegister Reg,
}

static bool targetSupportsPAuthRelocation(const Triple &TT,
const MCExpr *Target) {
const MCExpr *Target,
const MCExpr *DSExpr) {
// No released version of glibc supports PAuth relocations.
if (TT.isOSGlibc())
return false;

// We emit PAuth constants as IRELATIVE relocations in cases where the
// constant cannot be represented as a PAuth relocation:
// 1) The signed value is not a symbol.
return !isa<MCConstantExpr>(Target);
// 1) There is a deactivation symbol.
// 2) The signed value is not a symbol.
return !DSExpr && !isa<MCConstantExpr>(Target);
}

static bool targetSupportsIRelativeRelocation(const Triple &TT) {
Expand All @@ -2368,12 +2370,12 @@ static bool targetSupportsIRelativeRelocation(const Triple &TT) {

const MCExpr *AArch64AsmPrinter::emitPAuthRelocationAsIRelative(
const MCExpr *Target, uint16_t Disc, AArch64PACKey::ID KeyID,
bool HasAddressDiversity, bool IsDSOLocal) {
bool HasAddressDiversity, bool IsDSOLocal, const MCExpr *DSExpr) {
const Triple &TT = TM.getTargetTriple();

// We only emit an IRELATIVE relocation if the target supports IRELATIVE and
// does not support the kind of PAuth relocation that we are trying to emit.
if (targetSupportsPAuthRelocation(TT, Target) ||
if (targetSupportsPAuthRelocation(TT, Target, DSExpr) ||
!targetSupportsIRelativeRelocation(TT))
return nullptr;

Expand Down Expand Up @@ -2417,6 +2419,16 @@ const MCExpr *AArch64AsmPrinter::emitPAuthRelocationAsIRelative(
emitMOVZ(AArch64::X1, Disc, 0);
}

if (DSExpr) {
MCSymbol *PrePACInst = OutStreamer->getContext().createTempSymbol();
OutStreamer->emitLabel(PrePACInst);

auto *PrePACInstExpr =
MCSymbolRefExpr::create(PrePACInst, OutStreamer->getContext());
OutStreamer->emitRelocDirective(*PrePACInstExpr, "R_AARCH64_PATCHINST",
DSExpr, SMLoc());
}

// We don't know the subtarget because this is being emitted for a global
// initializer. Because the performance of IFUNC resolvers is unimportant, we
// always call the EmuPAC runtime, which will end up using the PAC instruction
Expand All @@ -2427,6 +2439,12 @@ const MCExpr *AArch64AsmPrinter::emitPAuthRelocationAsIRelative(
MCSymbolRefExpr::create(EmuPAC, OutStreamer->getContext());
OutStreamer->emitInstruction(MCInstBuilder(AArch64::B).addExpr(EmuPACRef),
*STI);

// We need a RET despite the above tail call because the deactivation symbol
// may replace it with a NOP.
if (DSExpr)
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::RET).addReg(AArch64::LR), *STI);
OutStreamer->popSection();

return MCSymbolRefExpr::create(IRelativeSym, AArch64::S_FUNCINIT,
Expand Down Expand Up @@ -2458,6 +2476,13 @@ AArch64AsmPrinter::lowerConstantPtrAuth(const ConstantPtrAuth &CPA) {
Sym = MCConstantExpr::create(Offset.getSExtValue(), Ctx);
}

const MCExpr *DSExpr = nullptr;
if (auto *DS = dyn_cast<GlobalValue>(CPA.getDeactivationSymbol())) {
if (isa<GlobalAlias>(DS))
return Sym;
DSExpr = MCSymbolRefExpr::create(getSymbol(DS), Ctx);
}

uint64_t KeyID = CPA.getKey()->getZExtValue();
// We later rely on valid KeyID value in AArch64PACKeyIDToString call from
// AArch64AuthMCExpr::printImpl, so fail fast.
Expand All @@ -2478,9 +2503,13 @@ AArch64AsmPrinter::lowerConstantPtrAuth(const ConstantPtrAuth &CPA) {
// Check if we need to represent this with an IRELATIVE and emit it if so.
if (auto *IFuncSym = emitPAuthRelocationAsIRelative(
Sym, Disc, AArch64PACKey::ID(KeyID), CPA.hasAddressDiscriminator(),
BaseGVB && BaseGVB->isDSOLocal()))
BaseGVB && BaseGVB->isDSOLocal(), DSExpr))
return IFuncSym;

if (DSExpr)
report_fatal_error("deactivation symbols unsupported in constant "
"expressions on this target");

// Finally build the complete @AUTH expr.
return AArch64AuthMCExpr::create(Sym, Disc, AArch64PACKey::ID(KeyID),
CPA.hasAddressDiscriminator(), Ctx);
Expand Down
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