[clang-tools-extra] [clang-tidy] introduce a must use check (PR #76101)

[Tyler Rockwood via cfe-commits]

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@@ -0,0 +1,40 @@
+//===--- MustUseCheck.h - clang-tidy ----------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_MUSTUSECHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_MUSTUSECHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::misc {
+
+/// Warns when not using a variable of a specific type within a function. This
+/// enforces a stronger check than clang's unused-variable warnings, as in C++
+/// this warning is not fired if the class has a custom destructor, or in
+/// templates. This check allows re-enabling unused variable warnings in all
+/// situations for specific classes.
+///
+/// The check supports this option:
+///   - 'Types': a semicolon-separated list of types to ensure must be used.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/misc/must-use.html
+class MustUseCheck : public ClangTidyCheck {
+public:
+  MustUseCheck(StringRef Name, ClangTidyContext *Context);
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
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rockwotj wrote:

Done.

https://github.com/llvm/llvm-project/pull/76101