[clang-tools-extra] [clang-tidy] Add `bugprone-virtual-arithmetic` check (PR #91951)

[Piotr Zegar via cfe-commits]

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@@ -0,0 +1,49 @@
+//===--- VirtualArithmeticCheck.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 "VirtualArithmeticCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+void VirtualArithmeticCheck::registerMatchers(MatchFinder *Finder) {
+  const auto PointerExprWithVirtualMethod =
+      expr(hasType(pointerType(pointee(hasDeclaration(
+               cxxRecordDecl(hasMethod(isVirtualAsWritten())))))))
+          .bind("pointer");
----------------
PiotrZSL wrote:

may not work for classes that derive from virtual one. You should create new AST matcher an use here: "[isPolymorphic](https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html#a6989371936079ccd01556c99637e9de0) ()"

https://github.com/llvm/llvm-project/pull/91951