[clang-tools-extra] Add clang-tidy check readability-math-missing-parentheses (PR #84481)

[Julian Schmidt via cfe-commits]

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@@ -0,0 +1,68 @@
+//===--- MathMissingParenthesesCheck.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 "MathMissingParenthesesCheck.h"
+#include "../utils/ASTUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include <iostream>
+using namespace std;
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+void MathMissingParenthesesCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(binaryOperator(unless(hasParent(binaryOperator())),
+                                    hasDescendant(binaryOperator()))
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5chmidti wrote:

(No need to implement this now)

This check should also detect `cxxOperatorCallExpr` and `cxxRewrittenBinaryOperator` (e.g., pair-/tuple-like types with overloaded operators). However, the issues I see with this are using `ostream`, `istream` and `ranges::views`. I think for those two AST nodes, the operators should be restricted to `+-*/%`. Any thoughts on this? 

https://github.com/llvm/llvm-project/pull/84481