Revert "CodeGen: Properly null-check typeid expressions"

This reverts commit r213401, r213402, r213403, and r213404.

I accidently committed these changes instead of updating the
differential.

llvm-svn: 213405

1 files changed, 6 insertions, 35 deletions

diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 5c4e1f1266d..47dc9fbbc73 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -1615,35 +1615,6 @@ void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
   EmitBlock(DeleteEnd);
 }
 
-static bool isGLValueFromPointerDeref(const Expr *E) {
-  E = E->IgnoreParens();
-
-  if (const auto *CE = dyn_cast<CastExpr>(E)) {
-    if (!CE->getSubExpr()->isGLValue())
-      return false;
-    return isGLValueFromPointerDeref(CE->getSubExpr());
-  }
-
-  if (const auto *BO = dyn_cast<BinaryOperator>(E))
-    if (BO->getOpcode() == BO_Comma)
-      return isGLValueFromPointerDeref(BO->getRHS());
-
-  if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E))
-    return isGLValueFromPointerDeref(ACO->getTrueExpr()) ||
-           isGLValueFromPointerDeref(ACO->getFalseExpr());
-
-  // C++11 [expr.sub]p1:
-  //   The expression E1[E2] is identical (by definition) to *((E1)+(E2))
-  if (isa<ArraySubscriptExpr>(E))
-    return true;
-
-  if (const auto *UO = dyn_cast<UnaryOperator>(E))
-    if (UO->getOpcode() == UO_Deref)
-      return true;
-
-  return false;
-}
-
 static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
                                          llvm::Type *StdTypeInfoPtrTy) {
   // Get the vtable pointer.
@@ -1653,13 +1624,13 @@ static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
   //   If the glvalue expression is obtained by applying the unary * operator to
   //   a pointer and the pointer is a null pointer value, the typeid expression
   //   throws the std::bad_typeid exception.
-  //
-  // However, this paragraph's intent is not clear.  We choose a very generous
-  // interpretation which implores us to consider comma operators, conditional
-  // operators, parentheses and other such constructs.
+  bool IsDeref = false;
+  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens()))
+    if (UO->getOpcode() == UO_Deref)
+      IsDeref = true;
+
   QualType SrcRecordTy = E->getType();
-  if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(
-          isGLValueFromPointerDeref(E), SrcRecordTy)) {
+  if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(IsDeref, SrcRecordTy)) {
     llvm::BasicBlock *BadTypeidBlock =
         CGF.createBasicBlock("typeid.bad_typeid");
     llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");