[clang-tools-extra] [clang-tidy] Add readability-constant-operand-order check (PR #167158)

[via cfe-commits]

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@@ -0,0 +1,197 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 "ConstantOperandOrderCheck.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/OperationKinds.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+/// Out-of-line ctor so vtable is emitted.
+ConstantOperandOrderCheck::ConstantOperandOrderCheck(StringRef Name,
+                                                     ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+  // Read options (StringRef -> std::string).
+  PreferredSide = Options.get(PreferredSideOption, "Right").str();
+
+  // Parse BinaryOperators option (comma-separated).
+  std::string OpsCSV =
+      Options.get(BinaryOperatorsOption, "==,!=,<,<=,>,>=").str();
+
+  llvm::SmallVector<llvm::StringRef, 8> Tokens;
+  llvm::StringRef(OpsCSV).split(Tokens, ',');
+  Operators.clear();
+  for (auto Tok : Tokens) {
+    llvm::StringRef Trim = Tok.trim();
+    if (!Trim.empty())
+      Operators.emplace_back(Trim.str());
+  }
+}
+
+ConstantOperandOrderCheck::~ConstantOperandOrderCheck() = default;
+
+void ConstantOperandOrderCheck::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, PreferredSideOption, PreferredSide);
+  Options.store(Opts, BinaryOperatorsOption,
+                llvm::join(Operators.begin(), Operators.end(), ","));
+}
+
+// ------------------------ helpers ------------------------
+
+namespace {
----------------
EugeneZelenko wrote:

No need for anonymous namespace. `static` is enough.

https://github.com/llvm/llvm-project/pull/167158