[clang-tools-extra] Add refactoring tool to convert between ternary (?:) expressions and equivalent if/else statements (PR #166822)

[via cfe-commits]

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@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This check detects ternary conditional (?:) expressions and replaces them
+// with equivalent if/else statements to improve code readability.
+//
+// Example:
+//
+//   int x = cond ? 1 : 2;
+//
+// Becomes:
+//
+//   int x;
+//   if (cond)
+//     x = 1;
+//   else
+//     x = 2;
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConditionalToIfCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h" // <-- ADD THIS INCLUDE
+#include "clang/Rewrite/Core/Rewriter.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+void ConditionalToIfCheck::registerMatchers(MatchFinder *Finder) {
+  // Match ternary conditional operators (?:)
+  Finder->addMatcher(
+      conditionalOperator(hasTrueExpression(expr().bind("trueExpr")),
+                          hasFalseExpression(expr().bind("falseExpr")),
+                          hasCondition(expr().bind("condExpr")))
+          .bind("ternary"),
+      this);
+}
+
+void ConditionalToIfCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Ternary = Result.Nodes.getNodeAs<ConditionalOperator>("ternary");
+  if (!Ternary)
+    return;
+
+  const Expr *Cond = Result.Nodes.getNodeAs<Expr>("condExpr");
+  const Expr *TrueExpr = Result.Nodes.getNodeAs<Expr>("trueExpr");
+  const Expr *FalseExpr = Result.Nodes.getNodeAs<Expr>("falseExpr");
+
+  if (!Cond || !TrueExpr || !FalseExpr)
+    return;
+
+  const SourceManager &SM = *Result.SourceManager;
+
+  auto Diag =
+      diag(Ternary->getBeginLoc(),
+           "replace ternary operator with if/else statement for readability");
+
+  // Extract source text for condition, true and false expressions
+  const std::string CondStr = Lexer::getSourceText(CharSourceRange::getTokenRange(
+                                                 Cond->getSourceRange()),
+                                             SM, Result.Context->getLangOpts())
+                            .str();
+
+  std::string TrueStr = Lexer::getSourceText(CharSourceRange::getTokenRange(
+                                                 TrueExpr->getSourceRange()),
+                                             SM, Result.Context->getLangOpts())
+                            .str();
+
+  std::string FalseStr = Lexer::getSourceText(CharSourceRange::getTokenRange(
----------------
EugeneZelenko wrote:

```suggestion
  const std::string FalseStr = Lexer::getSourceText(CharSourceRange::getTokenRange(
```

https://github.com/llvm/llvm-project/pull/166822