[opaque pointer type] API migration for GEP constant factories

Require the pointee type to be passed explicitly and assert that it is
correct. For now it's possible to pass nullptr here (and I've done so in
a few places in this patch) but eventually that will be disallowed once
all clients have been updated or removed. It'll be a long road to get
all the way there... but if you have the cahnce to update your callers
to pass the type explicitly without depending on a pointer's element
type, that would be a good thing to do soon and a necessary thing to do
eventually.

llvm-svn: 233938

1 files changed, 15 insertions, 13 deletions

diff --git a/llvm/lib/IR/Constants.cpp b/llvm/lib/IR/Constants.cpp
index 8c6eda2a772..3f8d1f1ca6a 100644
--- a/llvm/lib/IR/Constants.cpp
+++ b/llvm/lib/IR/Constants.cpp
@@ -1252,7 +1252,7 @@ Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2],
                                           OnlyIfReducedTy);
   case Instruction::GetElementPtr:
-    return ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1),
+    return ConstantExpr::getGetElementPtr(nullptr, Ops[0], Ops.slice(1),
                                           cast<GEPOperator>(this)->isInBounds(),
                                           OnlyIfReducedTy);
   case Instruction::ICmp:
@@ -1925,7 +1925,7 @@ Constant *ConstantExpr::getSizeOf(Type* Ty) {
   // Note that a non-inbounds gep is used, as null isn't within any object.
   Constant *GEPIdx = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
   Constant *GEP = getGetElementPtr(
-                 Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
+      Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
   return getPtrToInt(GEP, 
                      Type::getInt64Ty(Ty->getContext()));
 }
@@ -1939,7 +1939,7 @@ Constant *ConstantExpr::getAlignOf(Type* Ty) {
   Constant *Zero = ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0);
   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
   Constant *Indices[2] = { Zero, One };
-  Constant *GEP = getGetElementPtr(NullPtr, Indices);
+  Constant *GEP = getGetElementPtr(AligningTy, NullPtr, Indices);
   return getPtrToInt(GEP,
                      Type::getInt64Ty(Ty->getContext()));
 }
@@ -1957,7 +1957,7 @@ Constant *ConstantExpr::getOffsetOf(Type* Ty, Constant *FieldNo) {
     FieldNo
   };
   Constant *GEP = getGetElementPtr(
-                Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
+      Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
   return getPtrToInt(GEP,
                      Type::getInt64Ty(Ty->getContext()));
 }
@@ -2001,20 +2001,22 @@ Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2,
   return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
 }
 
-Constant *ConstantExpr::getGetElementPtr(Constant *C, ArrayRef<Value *> Idxs,
-                                         bool InBounds, Type *OnlyIfReducedTy) {
-  assert(C->getType()->isPtrOrPtrVectorTy() &&
-         "Non-pointer type for constant GetElementPtr expression");
-
+Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
+                                         ArrayRef<Value *> Idxs, bool InBounds,
+                                         Type *OnlyIfReducedTy) {
   if (Constant *FC = ConstantFoldGetElementPtr(C, InBounds, Idxs))
     return FC;          // Fold a few common cases.
 
+  if (!Ty)
+    Ty = cast<PointerType>(C->getType()->getScalarType())->getElementType();
+  else
+    assert(Ty ==
+           cast<PointerType>(C->getType()->getScalarType())->getElementType());
   // Get the result type of the getelementptr!
-  Type *Ty = GetElementPtrInst::getIndexedType(
-      cast<PointerType>(C->getType()->getScalarType())->getElementType(), Idxs);
-  assert(Ty && "GEP indices invalid!");
+  Type *DestTy = GetElementPtrInst::getIndexedType(Ty, Idxs);
+  assert(DestTy && "GEP indices invalid!");
   unsigned AS = C->getType()->getPointerAddressSpace();
-  Type *ReqTy = Ty->getPointerTo(AS);
+  Type *ReqTy = DestTy->getPointerTo(AS);
   if (VectorType *VecTy = dyn_cast<VectorType>(C->getType()))
     ReqTy = VectorType::get(ReqTy, VecTy->getNumElements());