[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#86721)

To authenticate pointers, CodeGen needs access to the key and
discriminators that were used to sign the pointer. That information is
sometimes known from the context, but not always, which is why `Address`
needs to hold that information.

This patch adds methods and data members to `Address`, which will be
needed in subsequent patches to authenticate signed pointers, and uses
the newly added methods throughout CodeGen. Although this patch isn't
strictly NFC as it causes CodeGen to use different code paths in some
cases (e.g., `mergeAddressesInConditionalExpr`), it doesn't cause any
changes in functionality as it doesn't add any information needed for
authentication.

In addition to the changes mentioned above, this patch introduces class
`RawAddress`, which contains a pointer that we know is unsigned, and
adds several new functions for creating `Address` and `LValue` objects.

This reapplies 8bd1f9116aab879183f34707e6d21c7051d083b6. The commit
broke msan bots because LValue::IsKnownNonNull was uninitialized.

1 files changed, 16 insertions, 13 deletions

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 5190b22..143855a 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -294,10 +294,10 @@ void AggExprEmitter::withReturnValueSlot(
   // Otherwise, EmitCall will emit its own, notice that it's "unused", and end
   // its lifetime before we have the chance to emit a proper destructor call.
   bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() ||
-                 (RequiresDestruction && !Dest.getAddress().isValid());
+                 (RequiresDestruction && Dest.isIgnored());
 
   Address RetAddr = Address::invalid();
-  Address RetAllocaAddr = Address::invalid();
+  RawAddress RetAllocaAddr = RawAddress::invalid();
 
   EHScopeStack::stable_iterator LifetimeEndBlock;
   llvm::Value *LifetimeSizePtr = nullptr;
@@ -329,7 +329,8 @@ void AggExprEmitter::withReturnValueSlot(
   if (!UseTemp)
     return;
 
-  assert(Dest.isIgnored() || Dest.getPointer() != Src.getAggregatePointer());
+  assert(Dest.isIgnored() || Dest.emitRawPointer(CGF) !=
+                                 Src.getAggregatePointer(E->getType(), CGF));
   EmitFinalDestCopy(E->getType(), Src);
 
   if (!RequiresDestruction && LifetimeStartInst) {
@@ -448,7 +449,8 @@ AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
   llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
   llvm::Value *IdxStart[] = { Zero, Zero };
   llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(
-      ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxStart, "arraystart");
+      ArrayPtr.getElementType(), ArrayPtr.emitRawPointer(CGF), IdxStart,
+      "arraystart");
   CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
   ++Field;
 
@@ -465,7 +467,8 @@ AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
     // End pointer.
     llvm::Value *IdxEnd[] = { Zero, Size };
     llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(
-        ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxEnd, "arrayend");
+        ArrayPtr.getElementType(), ArrayPtr.emitRawPointer(CGF), IdxEnd,
+        "arrayend");
     CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
   } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
     // Length.
@@ -516,9 +519,9 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
   // down a level.
   llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
   llvm::Value *indices[] = { zero, zero };
-  llvm::Value *begin = Builder.CreateInBoundsGEP(
-      DestPtr.getElementType(), DestPtr.getPointer(), indices,
-      "arrayinit.begin");
+  llvm::Value *begin = Builder.CreateInBoundsGEP(DestPtr.getElementType(),
+                                                 DestPtr.emitRawPointer(CGF),
+                                                 indices, "arrayinit.begin");
 
   CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
   CharUnits elementAlign =
@@ -1059,7 +1062,7 @@ void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) {
     if (RV.isScalar())
       return {RV.getScalarVal(), nullptr};
     if (RV.isAggregate())
-      return {RV.getAggregatePointer(), nullptr};
+      return {RV.getAggregatePointer(E->getType(), CGF), nullptr};
     assert(RV.isComplex());
     return RV.getComplexVal();
   };
@@ -1818,7 +1821,7 @@ void AggExprEmitter::VisitCXXParenListOrInitListExpr(
     // else, clean it up for -O0 builds and general tidiness.
     if (!pushedCleanup && LV.isSimple())
       if (llvm::GetElementPtrInst *GEP =
-              dyn_cast<llvm::GetElementPtrInst>(LV.getPointer(CGF)))
+              dyn_cast<llvm::GetElementPtrInst>(LV.emitRawPointer(CGF)))
         if (GEP->use_empty())
           GEP->eraseFromParent();
   }
@@ -1849,9 +1852,9 @@ void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
   // destPtr is an array*. Construct an elementType* by drilling down a level.
   llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
   llvm::Value *indices[] = {zero, zero};
-  llvm::Value *begin = Builder.CreateInBoundsGEP(
-      destPtr.getElementType(), destPtr.getPointer(), indices,
-      "arrayinit.begin");
+  llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getElementType(),
+                                                 destPtr.emitRawPointer(CGF),
+                                                 indices, "arrayinit.begin");
 
   // Prepare to special-case multidimensional array initialization: we avoid
   // emitting multiple destructor loops in that case.