diff --git a/clang-tools-extra/clang-tidy/utils/Aliasing.cpp b/clang-tools-extra/clang-tidy/utils/Aliasing.cpp
new file mode 100644
index 0000000..3a88126
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/utils/Aliasing.cpp
@@ -0,0 +1,65 @@
+//===------------- Aliasing.cpp - clang-tidy ------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Aliasing.h"
+
+#include "clang/AST/Expr.h"
+
+namespace clang {
+namespace tidy {
+namespace utils {
+
+/// Return whether \p S is a reference to the declaration of \p Var.
+static bool isAccessForVar(const Stmt *S, const VarDecl *Var) {
+  if (const auto *DRE = dyn_cast<DeclRefExpr>(S))
+    return DRE->getDecl() == Var;
+
+  return false;
+}
+
+/// Return whether \p Var has a pointer or reference in \p S.
+static bool isPtrOrReferenceForVar(const Stmt *S, const VarDecl *Var) {
+  if (const auto *DS = dyn_cast<DeclStmt>(S)) {
+    for (const Decl *D : DS->getDeclGroup()) {
+      if (const auto *LeftVar = dyn_cast<VarDecl>(D)) {
+        if (LeftVar->hasInit() && LeftVar->getType()->isReferenceType()) {
+          return isAccessForVar(LeftVar->getInit(), Var);
+        }
+      }
+    }
+  } else if (const auto *UnOp = dyn_cast<UnaryOperator>(S)) {
+    if (UnOp->getOpcode() == UO_AddrOf)
+      return isAccessForVar(UnOp->getSubExpr(), Var);
+  }
+
+  return false;
+}
+
+/// Return whether \p Var has a pointer or reference in \p S.
+static bool hasPtrOrReferenceInStmt(const Stmt *S, const VarDecl *Var) {
+  if (isPtrOrReferenceForVar(S, Var))
+    return true;
+
+  for (const Stmt *Child : S->children()) {
+    if (!Child)
+      continue;
+
+    if (hasPtrOrReferenceInStmt(Child, Var))
+      return true;
+  }
+
+  return false;
+}
+
+bool hasPtrOrReferenceInFunc(const FunctionDecl *Func, const VarDecl *Var) {
+  return hasPtrOrReferenceInStmt(Func->getBody(), Var);
+}
+
+} // namespace utils
+} // namespace tidy
+} // namespace clang