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diff --git a/include/clang/Tooling/Refactoring/ASTSelection.h b/include/clang/Tooling/Refactoring/ASTSelection.h
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+//===--- ASTSelection.h - Clang refactoring library -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLING_REFACTOR_AST_SELECTION_H
+#define LLVM_CLANG_TOOLING_REFACTOR_AST_SELECTION_H
+
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/Basic/LLVM.h"
+#include "clang/Basic/SourceLocation.h"
+#include <vector>
+
+namespace clang {
+
+class ASTContext;
+
+namespace tooling {
+
+enum class SourceSelectionKind {
+  /// A node that's not selected.
+  None,
+
+  /// A node that's considered to be selected because the whole selection range
+  /// is inside of its source range.
+  ContainsSelection,
+  /// A node that's considered to be selected because the start of the selection
+  /// range is inside its source range.
+  ContainsSelectionStart,
+  /// A node that's considered to be selected because the end of the selection
+  /// range is inside its source range.
+  ContainsSelectionEnd,
+
+  /// A node that's considered to be selected because the node is entirely in
+  /// the selection range.
+  InsideSelection,
+};
+
+/// Represents a selected AST node.
+///
+/// AST selection is represented using a tree of \c SelectedASTNode. The tree
+/// follows the top-down shape of the actual AST. Each selected node has
+/// a selection kind. The kind might be none as the node itself might not
+/// actually be selected, e.g. a statement in macro whose child is in a macro
+/// argument.
+struct SelectedASTNode {
+  ast_type_traits::DynTypedNode Node;
+  SourceSelectionKind SelectionKind;
+  std::vector<SelectedASTNode> Children;
+
+  SelectedASTNode(const ast_type_traits::DynTypedNode &Node,
+                  SourceSelectionKind SelectionKind)
+      : Node(Node), SelectionKind(SelectionKind) {}
+  SelectedASTNode(SelectedASTNode &&) = default;
+  SelectedASTNode &operator=(SelectedASTNode &&) = default;
+
+  void dump(llvm::raw_ostream &OS = llvm::errs()) const;
+
+  using ReferenceType = std::reference_wrapper<const SelectedASTNode>;
+};
+
+/// Traverses the given ASTContext and creates a tree of selected AST nodes.
+///
+/// \returns None if no nodes are selected in the AST, or a selected AST node
+/// that corresponds to the TranslationUnitDecl otherwise.
+Optional<SelectedASTNode> findSelectedASTNodes(const ASTContext &Context,
+                                               SourceRange SelectionRange);
+
+/// An AST selection value that corresponds to a selection of a set of
+/// statements that belong to one body of code (like one function).
+///
+/// For example, the following selection in the source.
+///
+/// \code
+/// void function() {
+///  // selection begin:
+///  int x = 0;
+///  {
+///     // selection end
+///     x = 1;
+///  }
+///  x = 2;
+/// }
+/// \endcode
+///
+/// Would correspond to a code range selection of statements "int x = 0"
+/// and the entire compound statement that follows it.
+///
+/// A \c CodeRangeASTSelection value stores references to the full
+/// \c SelectedASTNode tree and should not outlive it.
+class CodeRangeASTSelection {
+public:
+  CodeRangeASTSelection(CodeRangeASTSelection &&) = default;
+  CodeRangeASTSelection &operator=(CodeRangeASTSelection &&) = default;
+
+  /// Returns the parent hierarchy (top to bottom) for the selected nodes.
+  ArrayRef<SelectedASTNode::ReferenceType> getParents() { return Parents; }
+
+  /// Returns the number of selected statements.
+  size_t size() const {
+    if (!AreChildrenSelected)
+      return 1;
+    return SelectedNode.get().Children.size();
+  }
+
+  const Stmt *operator[](size_t I) const {
+    if (!AreChildrenSelected) {
+      assert(I == 0 && "Invalid index");
+      return SelectedNode.get().Node.get<Stmt>();
+    }
+    return SelectedNode.get().Children[I].Node.get<Stmt>();
+  }
+
+  /// Returns true when a selected code range is in a function-like body
+  /// of code, like a function, method or a block.
+  ///
+  /// This function can be used to test against selected expressions that are
+  /// located outside of a function, e.g. global variable initializers, default
+  /// argument values, or even template arguments.
+  ///
+  /// Use the \c getFunctionLikeNearestParent to get the function-like parent
+  /// declaration.
+  bool isInFunctionLikeBodyOfCode() const;
+
+  /// Returns the nearest function-like parent declaration or null if such
+  /// declaration doesn't exist.
+  const Decl *getFunctionLikeNearestParent() const;
+
+  static Optional<CodeRangeASTSelection>
+  create(SourceRange SelectionRange, const SelectedASTNode &ASTSelection);
+
+private:
+  CodeRangeASTSelection(SelectedASTNode::ReferenceType SelectedNode,
+                        ArrayRef<SelectedASTNode::ReferenceType> Parents,
+                        bool AreChildrenSelected)
+      : SelectedNode(SelectedNode), Parents(Parents.begin(), Parents.end()),
+        AreChildrenSelected(AreChildrenSelected) {}
+
+  /// The reference to the selected node (or reference to the selected
+  /// child nodes).
+  SelectedASTNode::ReferenceType SelectedNode;
+  /// The parent hierarchy (top to bottom) for the selected noe.
+  llvm::SmallVector<SelectedASTNode::ReferenceType, 8> Parents;
+  /// True only when the children of the selected node are actually selected.
+  bool AreChildrenSelected;
+};
+
+} // end namespace tooling
+} // end namespace clang
+
+#endif // LLVM_CLANG_TOOLING_REFACTOR_AST_SELECTION_H