[clang-tidy]Add new check readability-avoid-nested-conditional-operator (#78022)

Finds nested conditional operator.
Nested conditional operators lead code hard to understand, so they
should be splited as several statement and stored in temporary varibale.

1 files changed, 33 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/AvoidNestedConditionalOperatorCheck.h b/clang-tools-extra/clang-tidy/readability/AvoidNestedConditionalOperatorCheck.h
new file mode 100644
index 0000000..9010156
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/AvoidNestedConditionalOperatorCheck.h
@@ -0,0 +1,33 @@
+//===--- AvoidNestedConditionalOperatorCheck.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_READABILITY_AVOID_NESTED_CONDITIONAL_OPERATOR_CHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOID_NESTED_CONDITIONAL_OPERATOR_CHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::readability {
+
+/// Identifies instances of nested conditional operators in the code.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-nested-conditional-operator.html
+class AvoidNestedConditionalOperatorCheck : public ClangTidyCheck {
+public:
+  AvoidNestedConditionalOperatorCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
+};
+
+} // namespace clang::tidy::readability
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOID_NESTED_CONDITIONAL_OPERATOR_CHECK_H