vendor/clang/clang-trunk-r366426

16 files changed, 805 insertions, 50 deletions

diff --git a/lib/Tooling/Refactoring/ASTSelection.cpp b/lib/Tooling/Refactoring/ASTSelection.cpp
index b8f996d8218c..64e57af59011 100644
--- a/lib/Tooling/Refactoring/ASTSelection.cpp
+++ b/lib/Tooling/Refactoring/ASTSelection.cpp
@@ -1,9 +1,8 @@
 //===--- ASTSelection.cpp - Clang refactoring library ---------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp b/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
index c0232c5da442..14fc66a979ae 100644
--- a/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
+++ b/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
@@ -1,9 +1,8 @@
 //===--- ASTSelectionRequirements.cpp - Clang refactoring library ---------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/AtomicChange.cpp b/lib/Tooling/Refactoring/AtomicChange.cpp
index e8b0fdbeb662..4cf63306d262 100644
--- a/lib/Tooling/Refactoring/AtomicChange.cpp
+++ b/lib/Tooling/Refactoring/AtomicChange.cpp
@@ -1,9 +1,8 @@
 //===--- AtomicChange.cpp - AtomicChange implementation -----------------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/Extract/Extract.cpp b/lib/Tooling/Refactoring/Extract/Extract.cpp
index 7a741bdb2e91..f5b94a462103 100644
--- a/lib/Tooling/Refactoring/Extract/Extract.cpp
+++ b/lib/Tooling/Refactoring/Extract/Extract.cpp
@@ -1,9 +1,8 @@
 //===--- Extract.cpp - Clang refactoring library --------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 ///
diff --git a/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp b/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
index 7fd8cc2d3c7f..533c373e35c4 100644
--- a/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
+++ b/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
@@ -1,9 +1,8 @@
 //===--- SourceExtraction.cpp - Clang refactoring library -----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/Extract/SourceExtraction.h b/lib/Tooling/Refactoring/Extract/SourceExtraction.h
index 4b4bd8b477ff..545eb6c1a11c 100644
--- a/lib/Tooling/Refactoring/Extract/SourceExtraction.h
+++ b/lib/Tooling/Refactoring/Extract/SourceExtraction.h
@@ -1,9 +1,8 @@
 //===--- SourceExtraction.cpp - Clang refactoring library -----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/RangeSelector.cpp b/lib/Tooling/Refactoring/RangeSelector.cpp
new file mode 100644
index 000000000000..768c02e2277b
--- /dev/null
+++ b/lib/Tooling/Refactoring/RangeSelector.cpp
@@ -0,0 +1,296 @@
+//===--- RangeSelector.cpp - RangeSelector implementations ------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/Refactoring/RangeSelector.h"
+#include "clang/AST/Expr.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/Refactoring/SourceCode.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+#include <string>
+#include <utility>
+#include <vector>
+
+using namespace clang;
+using namespace tooling;
+
+using ast_matchers::MatchFinder;
+using ast_type_traits::ASTNodeKind;
+using ast_type_traits::DynTypedNode;
+using llvm::Error;
+using llvm::StringError;
+
+using MatchResult = MatchFinder::MatchResult;
+
+static Error invalidArgumentError(Twine Message) {
+  return llvm::make_error<StringError>(llvm::errc::invalid_argument, Message);
+}
+
+static Error typeError(StringRef ID, const ASTNodeKind &Kind) {
+  return invalidArgumentError("mismatched type (node id=" + ID +
+                              " kind=" + Kind.asStringRef() + ")");
+}
+
+static Error typeError(StringRef ID, const ASTNodeKind &Kind,
+                       Twine ExpectedType) {
+  return invalidArgumentError("mismatched type: expected one of " +
+                              ExpectedType + " (node id=" + ID +
+                              " kind=" + Kind.asStringRef() + ")");
+}
+
+static Error missingPropertyError(StringRef ID, Twine Description,
+                                  StringRef Property) {
+  return invalidArgumentError(Description + " requires property '" + Property +
+                              "' (node id=" + ID + ")");
+}
+
+static Expected<DynTypedNode> getNode(const ast_matchers::BoundNodes &Nodes,
+                                      StringRef ID) {
+  auto &NodesMap = Nodes.getMap();
+  auto It = NodesMap.find(ID);
+  if (It == NodesMap.end())
+    return invalidArgumentError("ID not bound: " + ID);
+  return It->second;
+}
+
+// FIXME: handling of macros should be configurable.
+static SourceLocation findPreviousTokenStart(SourceLocation Start,
+                                             const SourceManager &SM,
+                                             const LangOptions &LangOpts) {
+  if (Start.isInvalid() || Start.isMacroID())
+    return SourceLocation();
+
+  SourceLocation BeforeStart = Start.getLocWithOffset(-1);
+  if (BeforeStart.isInvalid() || BeforeStart.isMacroID())
+    return SourceLocation();
+
+  return Lexer::GetBeginningOfToken(BeforeStart, SM, LangOpts);
+}
+
+// Finds the start location of the previous token of kind \p TK.
+// FIXME: handling of macros should be configurable.
+static SourceLocation findPreviousTokenKind(SourceLocation Start,
+                                            const SourceManager &SM,
+                                            const LangOptions &LangOpts,
+                                            tok::TokenKind TK) {
+  while (true) {
+    SourceLocation L = findPreviousTokenStart(Start, SM, LangOpts);
+    if (L.isInvalid() || L.isMacroID())
+      return SourceLocation();
+
+    Token T;
+    if (Lexer::getRawToken(L, T, SM, LangOpts, /*IgnoreWhiteSpace=*/true))
+      return SourceLocation();
+
+    if (T.is(TK))
+      return T.getLocation();
+
+    Start = L;
+  }
+}
+
+static SourceLocation findOpenParen(const CallExpr &E, const SourceManager &SM,
+                                    const LangOptions &LangOpts) {
+  SourceLocation EndLoc =
+      E.getNumArgs() == 0 ? E.getRParenLoc() : E.getArg(0)->getBeginLoc();
+  return findPreviousTokenKind(EndLoc, SM, LangOpts, tok::TokenKind::l_paren);
+}
+
+RangeSelector tooling::before(RangeSelector Selector) {
+  return [Selector](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<CharSourceRange> SelectedRange = Selector(Result);
+    if (!SelectedRange)
+      return SelectedRange.takeError();
+    return CharSourceRange::getCharRange(SelectedRange->getBegin());
+  };
+}
+
+RangeSelector tooling::after(RangeSelector Selector) {
+  return [Selector](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<CharSourceRange> SelectedRange = Selector(Result);
+    if (!SelectedRange)
+      return SelectedRange.takeError();
+    if (SelectedRange->isCharRange())
+      return CharSourceRange::getCharRange(SelectedRange->getEnd());
+    return CharSourceRange::getCharRange(Lexer::getLocForEndOfToken(
+        SelectedRange->getEnd(), 0, Result.Context->getSourceManager(),
+        Result.Context->getLangOpts()));
+  };
+}
+
+RangeSelector tooling::node(std::string ID) {
+  return [ID](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<DynTypedNode> Node = getNode(Result.Nodes, ID);
+    if (!Node)
+      return Node.takeError();
+    return Node->get<Stmt>() != nullptr && Node->get<Expr>() == nullptr
+               ? getExtendedRange(*Node, tok::TokenKind::semi, *Result.Context)
+               : CharSourceRange::getTokenRange(Node->getSourceRange());
+  };
+}
+
+RangeSelector tooling::statement(std::string ID) {
+  return [ID](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<DynTypedNode> Node = getNode(Result.Nodes, ID);
+    if (!Node)
+      return Node.takeError();
+    return getExtendedRange(*Node, tok::TokenKind::semi, *Result.Context);
+  };
+}
+
+RangeSelector tooling::range(RangeSelector Begin, RangeSelector End) {
+  return [Begin, End](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<CharSourceRange> BeginRange = Begin(Result);
+    if (!BeginRange)
+      return BeginRange.takeError();
+    Expected<CharSourceRange> EndRange = End(Result);
+    if (!EndRange)
+      return EndRange.takeError();
+    SourceLocation B = BeginRange->getBegin();
+    SourceLocation E = EndRange->getEnd();
+    // Note: we are precluding the possibility of sub-token ranges in the case
+    // that EndRange is a token range.
+    if (Result.SourceManager->isBeforeInTranslationUnit(E, B)) {
+      return invalidArgumentError("Bad range: out of order");
+    }
+    return CharSourceRange(SourceRange(B, E), EndRange->isTokenRange());
+  };
+}
+
+RangeSelector tooling::range(std::string BeginID, std::string EndID) {
+  return tooling::range(node(std::move(BeginID)), node(std::move(EndID)));
+}
+
+RangeSelector tooling::member(std::string ID) {
+  return [ID](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<DynTypedNode> Node = getNode(Result.Nodes, ID);
+    if (!Node)
+      return Node.takeError();
+    if (auto *M = Node->get<clang::MemberExpr>())
+      return CharSourceRange::getTokenRange(
+          M->getMemberNameInfo().getSourceRange());
+    return typeError(ID, Node->getNodeKind(), "MemberExpr");
+  };
+}
+
+RangeSelector tooling::name(std::string ID) {
+  return [ID](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<DynTypedNode> N = getNode(Result.Nodes, ID);
+    if (!N)
+      return N.takeError();
+    auto &Node = *N;
+    if (const auto *D = Node.get<NamedDecl>()) {
+      if (!D->getDeclName().isIdentifier())
+        return missingPropertyError(ID, "name", "identifier");
+      SourceLocation L = D->getLocation();
+      auto R = CharSourceRange::getTokenRange(L, L);
+      // Verify that the range covers exactly the name.
+      // FIXME: extend this code to support cases like `operator +` or
+      // `foo<int>` for which this range will be too short.  Doing so will
+      // require subcasing `NamedDecl`, because it doesn't provide virtual
+      // access to the \c DeclarationNameInfo.
+      if (getText(R, *Result.Context) != D->getName())
+        return CharSourceRange();
+      return R;
+    }
+    if (const auto *E = Node.get<DeclRefExpr>()) {
+      if (!E->getNameInfo().getName().isIdentifier())
+        return missingPropertyError(ID, "name", "identifier");
+      SourceLocation L = E->getLocation();
+      return CharSourceRange::getTokenRange(L, L);
+    }
+    if (const auto *I = Node.get<CXXCtorInitializer>()) {
+      if (!I->isMemberInitializer() && I->isWritten())
+        return missingPropertyError(ID, "name", "explicit member initializer");
+      SourceLocation L = I->getMemberLocation();
+      return CharSourceRange::getTokenRange(L, L);
+    }
+    return typeError(ID, Node.getNodeKind(),
+                     "DeclRefExpr, NamedDecl, CXXCtorInitializer");
+  };
+}
+
+namespace {
+// Creates a selector from a range-selection function \p Func, which selects a
+// range that is relative to a bound node id.  \c T is the node type expected by
+// \p Func.
+template <typename T, CharSourceRange (*Func)(const MatchResult &, const T &)>
+class RelativeSelector {
+  std::string ID;
+
+public:
+  RelativeSelector(std::string ID) : ID(std::move(ID)) {}
+
+  Expected<CharSourceRange> operator()(const MatchResult &Result) {
+    Expected<DynTypedNode> N = getNode(Result.Nodes, ID);
+    if (!N)
+      return N.takeError();
+    if (const auto *Arg = N->get<T>())
+      return Func(Result, *Arg);
+    return typeError(ID, N->getNodeKind());
+  }
+};
+} // namespace
+
+// FIXME: Change the following functions from being in an anonymous namespace
+// to static functions, after the minimum Visual C++ has _MSC_VER >= 1915
+// (equivalent to Visual Studio 2017 v15.8 or higher). Using the anonymous
+// namespace works around a bug in earlier versions.
+namespace {
+// Returns the range of the statements (all source between the braces).
+CharSourceRange getStatementsRange(const MatchResult &,
+                                   const CompoundStmt &CS) {
+  return CharSourceRange::getCharRange(CS.getLBracLoc().getLocWithOffset(1),
+                                       CS.getRBracLoc());
+}
+} // namespace
+
+RangeSelector tooling::statements(std::string ID) {
+  return RelativeSelector<CompoundStmt, getStatementsRange>(std::move(ID));
+}
+
+namespace {
+// Returns the range of the source between the call's parentheses.
+CharSourceRange getCallArgumentsRange(const MatchResult &Result,
+                                      const CallExpr &CE) {
+  return CharSourceRange::getCharRange(
+      findOpenParen(CE, *Result.SourceManager, Result.Context->getLangOpts())
+          .getLocWithOffset(1),
+      CE.getRParenLoc());
+}
+} // namespace
+
+RangeSelector tooling::callArgs(std::string ID) {
+  return RelativeSelector<CallExpr, getCallArgumentsRange>(std::move(ID));
+}
+
+namespace {
+// Returns the range of the elements of the initializer list. Includes all
+// source between the braces.
+CharSourceRange getElementsRange(const MatchResult &,
+                                 const InitListExpr &E) {
+  return CharSourceRange::getCharRange(E.getLBraceLoc().getLocWithOffset(1),
+                                       E.getRBraceLoc());
+}
+} // namespace
+
+RangeSelector tooling::initListElements(std::string ID) {
+  return RelativeSelector<InitListExpr, getElementsRange>(std::move(ID));
+}
+
+RangeSelector tooling::expansion(RangeSelector S) {
+  return [S](const MatchResult &Result) -> Expected<CharSourceRange> {
+    Expected<CharSourceRange> SRange = S(Result);
+    if (!SRange)
+      return SRange.takeError();
+    return Result.SourceManager->getExpansionRange(*SRange);
+  };
+}
diff --git a/lib/Tooling/Refactoring/RefactoringActions.cpp b/lib/Tooling/Refactoring/RefactoringActions.cpp
index 37a1639cb446..1a3833243ab4 100644
--- a/lib/Tooling/Refactoring/RefactoringActions.cpp
+++ b/lib/Tooling/Refactoring/RefactoringActions.cpp
@@ -1,9 +1,8 @@
 //===--- RefactoringActions.cpp - Constructs refactoring actions ----------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/Rename/RenamingAction.cpp b/lib/Tooling/Refactoring/Rename/RenamingAction.cpp
index 44ffae90efa7..1649513a077a 100644
--- a/lib/Tooling/Refactoring/Rename/RenamingAction.cpp
+++ b/lib/Tooling/Refactoring/Rename/RenamingAction.cpp
@@ -1,9 +1,8 @@
 //===--- RenamingAction.cpp - Clang refactoring library -------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 ///
@@ -75,6 +74,8 @@ RenameOccurrences::initiate(RefactoringRuleContext &Context,
                            std::move(NewName));
 }
 
+const NamedDecl *RenameOccurrences::getRenameDecl() const { return ND; }
+
 Expected<AtomicChanges>
 RenameOccurrences::createSourceReplacements(RefactoringRuleContext &Context) {
   Expected<SymbolOccurrences> Occurrences = findSymbolOccurrences(ND, Context);
diff --git a/lib/Tooling/Refactoring/Rename/SymbolOccurrences.cpp b/lib/Tooling/Refactoring/Rename/SymbolOccurrences.cpp
index ea64b2c1aa8c..8cc1ffaf4482 100644
--- a/lib/Tooling/Refactoring/Rename/SymbolOccurrences.cpp
+++ b/lib/Tooling/Refactoring/Rename/SymbolOccurrences.cpp
@@ -1,9 +1,8 @@
 //===--- SymbolOccurrences.cpp - Clang refactoring library ----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Tooling/Refactoring/Rename/USRFinder.cpp b/lib/Tooling/Refactoring/Rename/USRFinder.cpp
index 4ed805fd504c..55111202ac88 100644
--- a/lib/Tooling/Refactoring/Rename/USRFinder.cpp
+++ b/lib/Tooling/Refactoring/Rename/USRFinder.cpp
@@ -1,9 +1,8 @@
 //===--- USRFinder.cpp - Clang refactoring library ------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 ///
diff --git a/lib/Tooling/Refactoring/Rename/USRFindingAction.cpp b/lib/Tooling/Refactoring/Rename/USRFindingAction.cpp
index 2e7c9b0cc31b..54c6f3e734b1 100644
--- a/lib/Tooling/Refactoring/Rename/USRFindingAction.cpp
+++ b/lib/Tooling/Refactoring/Rename/USRFindingAction.cpp
@@ -1,9 +1,8 @@
 //===--- USRFindingAction.cpp - Clang refactoring library -----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 ///
diff --git a/lib/Tooling/Refactoring/Rename/USRLocFinder.cpp b/lib/Tooling/Refactoring/Rename/USRLocFinder.cpp
index 7f60cf54c8ec..408e184f5bf5 100644
--- a/lib/Tooling/Refactoring/Rename/USRLocFinder.cpp
+++ b/lib/Tooling/Refactoring/Rename/USRLocFinder.cpp
@@ -1,9 +1,8 @@
 //===--- USRLocFinder.cpp - Clang refactoring library ---------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 ///
@@ -543,8 +542,8 @@ createRenameAtomicChanges(llvm::ArrayRef<std::string> USRs,
         if (!llvm::isa<clang::TranslationUnitDecl>(
                 RenameInfo.Context->getDeclContext())) {
           ReplacedName = tooling::replaceNestedName(
-              RenameInfo.Specifier, RenameInfo.Context->getDeclContext(),
-              RenameInfo.FromDecl,
+              RenameInfo.Specifier, RenameInfo.Begin,
+              RenameInfo.Context->getDeclContext(), RenameInfo.FromDecl,
               NewName.startswith("::") ? NewName.str()
                                        : ("::" + NewName).str());
         } else {
diff --git a/lib/Tooling/Refactoring/SourceCode.cpp b/lib/Tooling/Refactoring/SourceCode.cpp
new file mode 100644
index 000000000000..3a97e178bbd4
--- /dev/null
+++ b/lib/Tooling/Refactoring/SourceCode.cpp
@@ -0,0 +1,31 @@
+//===--- SourceCode.cpp - Source code manipulation routines -----*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file provides functions that simplify extraction of source code.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Tooling/Refactoring/SourceCode.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang;
+
+StringRef clang::tooling::getText(CharSourceRange Range,
+                                  const ASTContext &Context) {
+  return Lexer::getSourceText(Range, Context.getSourceManager(),
+                              Context.getLangOpts());
+}
+
+CharSourceRange clang::tooling::maybeExtendRange(CharSourceRange Range,
+                                                 tok::TokenKind Next,
+                                                 ASTContext &Context) {
+  Optional<Token> Tok = Lexer::findNextToken(
+      Range.getEnd(), Context.getSourceManager(), Context.getLangOpts());
+  if (!Tok || !Tok->is(Next))
+    return Range;
+  return CharSourceRange::getTokenRange(Range.getBegin(), Tok->getLocation());
+}
diff --git a/lib/Tooling/Refactoring/Stencil.cpp b/lib/Tooling/Refactoring/Stencil.cpp
new file mode 100644
index 000000000000..09eca21c3cef
--- /dev/null
+++ b/lib/Tooling/Refactoring/Stencil.cpp
@@ -0,0 +1,175 @@
+//===--- Stencil.cpp - Stencil implementation -------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/Refactoring/Stencil.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/AST/Expr.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/Refactoring/SourceCode.h"
+#include "llvm/Support/Errc.h"
+#include <atomic>
+#include <memory>
+#include <string>
+
+using namespace clang;
+using namespace tooling;
+
+using ast_matchers::MatchFinder;
+using llvm::Error;
+
+// A down_cast function to safely down cast a StencilPartInterface to a subclass
+// D. Returns nullptr if P is not an instance of D.
+template <typename D> const D *down_cast(const StencilPartInterface *P) {
+  if (P == nullptr || D::typeId() != P->typeId())
+    return nullptr;
+  return static_cast<const D *>(P);
+}
+
+static llvm::Expected<ast_type_traits::DynTypedNode>
+getNode(const ast_matchers::BoundNodes &Nodes, StringRef Id) {
+  auto &NodesMap = Nodes.getMap();
+  auto It = NodesMap.find(Id);
+  if (It == NodesMap.end())
+    return llvm::make_error<llvm::StringError>(llvm::errc::invalid_argument,
+                                               "Id not bound: " + Id);
+  return It->second;
+}
+
+namespace {
+// An arbitrary fragment of code within a stencil.
+struct RawTextData {
+  explicit RawTextData(std::string T) : Text(std::move(T)) {}
+  std::string Text;
+};
+
+// A debugging operation to dump the AST for a particular (bound) AST node.
+struct DebugPrintNodeOpData {
+  explicit DebugPrintNodeOpData(std::string S) : Id(std::move(S)) {}
+  std::string Id;
+};
+
+// The fragment of code corresponding to the selected range.
+struct SelectorOpData {
+  explicit SelectorOpData(RangeSelector S) : Selector(std::move(S)) {}
+  RangeSelector Selector;
+};
+} // namespace
+
+bool isEqualData(const RawTextData &A, const RawTextData &B) {
+  return A.Text == B.Text;
+}
+
+bool isEqualData(const DebugPrintNodeOpData &A, const DebugPrintNodeOpData &B) {
+  return A.Id == B.Id;
+}
+
+// Equality is not (yet) defined for \c RangeSelector.
+bool isEqualData(const SelectorOpData &, const SelectorOpData &) { return false; }
+
+// The `evalData()` overloads evaluate the given stencil data to a string, given
+// the match result, and append it to `Result`. We define an overload for each
+// type of stencil data.
+
+Error evalData(const RawTextData &Data, const MatchFinder::MatchResult &,
+               std::string *Result) {
+  Result->append(Data.Text);
+  return Error::success();
+}
+
+Error evalData(const DebugPrintNodeOpData &Data,
+               const MatchFinder::MatchResult &Match, std::string *Result) {
+  std::string Output;
+  llvm::raw_string_ostream Os(Output);
+  auto NodeOrErr = getNode(Match.Nodes, Data.Id);
+  if (auto Err = NodeOrErr.takeError())
+    return Err;
+  NodeOrErr->print(Os, PrintingPolicy(Match.Context->getLangOpts()));
+  *Result += Os.str();
+  return Error::success();
+}
+
+Error evalData(const SelectorOpData &Data, const MatchFinder::MatchResult &Match,
+               std::string *Result) {
+  auto Range = Data.Selector(Match);
+  if (!Range)
+    return Range.takeError();
+  *Result += getText(*Range, *Match.Context);
+  return Error::success();
+}
+
+template <typename T>
+class StencilPartImpl : public StencilPartInterface {
+  T Data;
+
+public:
+  template <typename... Ps>
+  explicit StencilPartImpl(Ps &&... Args)
+      : StencilPartInterface(StencilPartImpl::typeId()),
+        Data(std::forward<Ps>(Args)...) {}
+
+  // Generates a unique identifier for this class (specifically, one per
+  // instantiation of the template).
+  static const void* typeId() {
+    static bool b;
+    return &b;
+  }
+
+  Error eval(const MatchFinder::MatchResult &Match,
+             std::string *Result) const override {
+    return evalData(Data, Match, Result);
+  }
+
+  bool isEqual(const StencilPartInterface &Other) const override {
+    if (const auto *OtherPtr = down_cast<StencilPartImpl>(&Other))
+      return isEqualData(Data, OtherPtr->Data);
+    return false;
+  }
+};
+
+namespace {
+using RawText = StencilPartImpl<RawTextData>;
+using DebugPrintNodeOp = StencilPartImpl<DebugPrintNodeOpData>;
+using SelectorOp = StencilPartImpl<SelectorOpData>;
+} // namespace
+
+StencilPart Stencil::wrap(StringRef Text) {
+  return stencil::text(Text);
+}
+
+StencilPart Stencil::wrap(RangeSelector Selector) {
+  return stencil::selection(std::move(Selector));
+}
+
+void Stencil::append(Stencil OtherStencil) {
+  for (auto &Part : OtherStencil.Parts)
+    Parts.push_back(std::move(Part));
+}
+
+llvm::Expected<std::string>
+Stencil::eval(const MatchFinder::MatchResult &Match) const {
+  std::string Result;
+  for (const auto &Part : Parts)
+    if (auto Err = Part.eval(Match, &Result))
+      return std::move(Err);
+  return Result;
+}
+
+StencilPart stencil::text(StringRef Text) {
+  return StencilPart(std::make_shared<RawText>(Text));
+}
+
+StencilPart stencil::selection(RangeSelector Selector) {
+  return StencilPart(std::make_shared<SelectorOp>(std::move(Selector)));
+}
+
+StencilPart stencil::dPrint(StringRef Id) {
+  return StencilPart(std::make_shared<DebugPrintNodeOp>(Id));
+}
diff --git a/lib/Tooling/Refactoring/Transformer.cpp b/lib/Tooling/Refactoring/Transformer.cpp
new file mode 100644
index 000000000000..8e6fe6c7a940
--- /dev/null
+++ b/lib/Tooling/Refactoring/Transformer.cpp
@@ -0,0 +1,263 @@
+//===--- Transformer.cpp - Transformer library implementation ---*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/Refactoring/Transformer.h"
+#include "clang/AST/Expr.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "clang/Tooling/Refactoring/AtomicChange.h"
+#include "clang/Tooling/Refactoring/SourceCode.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+#include <deque>
+#include <string>
+#include <utility>
+#include <vector>
+
+using namespace clang;
+using namespace tooling;
+
+using ast_matchers::MatchFinder;
+using ast_matchers::internal::DynTypedMatcher;
+using ast_type_traits::ASTNodeKind;
+using ast_type_traits::DynTypedNode;
+using llvm::Error;
+using llvm::StringError;
+
+using MatchResult = MatchFinder::MatchResult;
+
+// Did the text at this location originate in a macro definition (aka. body)?
+// For example,
+//
+//   #define NESTED(x) x
+//   #define MACRO(y) { int y  = NESTED(3); }
+//   if (true) MACRO(foo)
+//
+// The if statement expands to
+//
+//   if (true) { int foo = 3; }
+//                   ^     ^
+//                   Loc1  Loc2
+//
+// For SourceManager SM, SM.isMacroArgExpansion(Loc1) and
+// SM.isMacroArgExpansion(Loc2) are both true, but isOriginMacroBody(sm, Loc1)
+// is false, because "foo" originated in the source file (as an argument to a
+// macro), whereas isOriginMacroBody(SM, Loc2) is true, because "3" originated
+// in the definition of MACRO.
+static bool isOriginMacroBody(const clang::SourceManager &SM,
+                              clang::SourceLocation Loc) {
+  while (Loc.isMacroID()) {
+    if (SM.isMacroBodyExpansion(Loc))
+      return true;
+    // Otherwise, it must be in an argument, so we continue searching up the
+    // invocation stack. getImmediateMacroCallerLoc() gives the location of the
+    // argument text, inside the call text.
+    Loc = SM.getImmediateMacroCallerLoc(Loc);
+  }
+  return false;
+}
+
+Expected<SmallVector<tooling::detail::Transformation, 1>>
+tooling::detail::translateEdits(const MatchResult &Result,
+                                llvm::ArrayRef<ASTEdit> Edits) {
+  SmallVector<tooling::detail::Transformation, 1> Transformations;
+  for (const auto &Edit : Edits) {
+    Expected<CharSourceRange> Range = Edit.TargetRange(Result);
+    if (!Range)
+      return Range.takeError();
+    if (Range->isInvalid() ||
+        isOriginMacroBody(*Result.SourceManager, Range->getBegin()))
+      return SmallVector<Transformation, 0>();
+    auto Replacement = Edit.Replacement(Result);
+    if (!Replacement)
+      return Replacement.takeError();
+    tooling::detail::Transformation T;
+    T.Range = *Range;
+    T.Replacement = std::move(*Replacement);
+    Transformations.push_back(std::move(T));
+  }
+  return Transformations;
+}
+
+ASTEdit tooling::change(RangeSelector S, TextGenerator Replacement) {
+  ASTEdit E;
+  E.TargetRange = std::move(S);
+  E.Replacement = std::move(Replacement);
+  return E;
+}
+
+RewriteRule tooling::makeRule(DynTypedMatcher M, SmallVector<ASTEdit, 1> Edits,
+                              TextGenerator Explanation) {
+  return RewriteRule{{RewriteRule::Case{
+      std::move(M), std::move(Edits), std::move(Explanation), {}}}};
+}
+
+void tooling::addInclude(RewriteRule &Rule, StringRef Header,
+                         IncludeFormat Format) {
+  for (auto &Case : Rule.Cases)
+    Case.AddedIncludes.emplace_back(Header.str(), Format);
+}
+
+// Determines whether A is a base type of B in the class hierarchy, including
+// the implicit relationship of Type and QualType.
+static bool isBaseOf(ASTNodeKind A, ASTNodeKind B) {
+  static auto TypeKind = ASTNodeKind::getFromNodeKind<Type>();
+  static auto QualKind = ASTNodeKind::getFromNodeKind<QualType>();
+  /// Mimic the implicit conversions of Matcher<>.
+  /// - From Matcher<Type> to Matcher<QualType>
+  /// - From Matcher<Base> to Matcher<Derived>
+  return (A.isSame(TypeKind) && B.isSame(QualKind)) || A.isBaseOf(B);
+}
+
+// Try to find a common kind to which all of the rule's matchers can be
+// converted.
+static ASTNodeKind
+findCommonKind(const SmallVectorImpl<RewriteRule::Case> &Cases) {
+  assert(!Cases.empty() && "Rule must have at least one case.");
+  ASTNodeKind JoinKind = Cases[0].Matcher.getSupportedKind();
+  // Find a (least) Kind K, for which M.canConvertTo(K) holds, for all matchers
+  // M in Rules.
+  for (const auto &Case : Cases) {
+    auto K = Case.Matcher.getSupportedKind();
+    if (isBaseOf(JoinKind, K)) {
+      JoinKind = K;
+      continue;
+    }
+    if (K.isSame(JoinKind) || isBaseOf(K, JoinKind))
+      // JoinKind is already the lowest.
+      continue;
+    // K and JoinKind are unrelated -- there is no least common kind.
+    return ASTNodeKind();
+  }
+  return JoinKind;
+}
+
+// Binds each rule's matcher to a unique (and deterministic) tag based on
+// `TagBase`.
+static std::vector<DynTypedMatcher>
+taggedMatchers(StringRef TagBase,
+               const SmallVectorImpl<RewriteRule::Case> &Cases) {
+  std::vector<DynTypedMatcher> Matchers;
+  Matchers.reserve(Cases.size());
+  size_t count = 0;
+  for (const auto &Case : Cases) {
+    std::string Tag = (TagBase + Twine(count)).str();
+    ++count;
+    auto M = Case.Matcher.tryBind(Tag);
+    assert(M && "RewriteRule matchers should be bindable.");
+    Matchers.push_back(*std::move(M));
+  }
+  return Matchers;
+}
+
+// Simply gathers the contents of the various rules into a single rule. The
+// actual work to combine these into an ordered choice is deferred to matcher
+// registration.
+RewriteRule tooling::applyFirst(ArrayRef<RewriteRule> Rules) {
+  RewriteRule R;
+  for (auto &Rule : Rules)
+    R.Cases.append(Rule.Cases.begin(), Rule.Cases.end());
+  return R;
+}
+
+static DynTypedMatcher joinCaseMatchers(const RewriteRule &Rule) {
+  assert(!Rule.Cases.empty() && "Rule must have at least one case.");
+  if (Rule.Cases.size() == 1)
+    return Rule.Cases[0].Matcher;
+
+  auto CommonKind = findCommonKind(Rule.Cases);
+  assert(!CommonKind.isNone() && "Cases must have compatible matchers.");
+  return DynTypedMatcher::constructVariadic(
+      DynTypedMatcher::VO_AnyOf, CommonKind, taggedMatchers("Tag", Rule.Cases));
+}
+
+DynTypedMatcher tooling::detail::buildMatcher(const RewriteRule &Rule) {
+  DynTypedMatcher M = joinCaseMatchers(Rule);
+  M.setAllowBind(true);
+  // `tryBind` is guaranteed to succeed, because `AllowBind` was set to true.
+  return *M.tryBind(RewriteRule::RootID);
+}
+
+// Finds the case that was "selected" -- that is, whose matcher triggered the
+// `MatchResult`.
+const RewriteRule::Case &
+tooling::detail::findSelectedCase(const MatchResult &Result,
+                                  const RewriteRule &Rule) {
+  if (Rule.Cases.size() == 1)
+    return Rule.Cases[0];
+
+  auto &NodesMap = Result.Nodes.getMap();
+  for (size_t i = 0, N = Rule.Cases.size(); i < N; ++i) {
+    std::string Tag = ("Tag" + Twine(i)).str();
+    if (NodesMap.find(Tag) != NodesMap.end())
+      return Rule.Cases[i];
+  }
+  llvm_unreachable("No tag found for this rule.");
+}
+
+constexpr llvm::StringLiteral RewriteRule::RootID;
+
+void Transformer::registerMatchers(MatchFinder *MatchFinder) {
+  MatchFinder->addDynamicMatcher(tooling::detail::buildMatcher(Rule), this);
+}
+
+void Transformer::run(const MatchResult &Result) {
+  if (Result.Context->getDiagnostics().hasErrorOccurred())
+    return;
+
+  // Verify the existence and validity of the AST node that roots this rule.
+  auto &NodesMap = Result.Nodes.getMap();
+  auto Root = NodesMap.find(RewriteRule::RootID);
+  assert(Root != NodesMap.end() && "Transformation failed: missing root node.");
+  SourceLocation RootLoc = Result.SourceManager->getExpansionLoc(
+      Root->second.getSourceRange().getBegin());
+  assert(RootLoc.isValid() && "Invalid location for Root node of match.");
+
+  RewriteRule::Case Case = tooling::detail::findSelectedCase(Result, Rule);
+  auto Transformations = tooling::detail::translateEdits(Result, Case.Edits);
+  if (!Transformations) {
+    Consumer(Transformations.takeError());
+    return;
+  }
+
+  if (Transformations->empty()) {
+    // No rewrite applied (but no error encountered either).
+    RootLoc.print(llvm::errs() << "note: skipping match at loc ",
+                  *Result.SourceManager);
+    llvm::errs() << "\n";
+    return;
+  }
+
+  // Record the results in the AtomicChange.
+  AtomicChange AC(*Result.SourceManager, RootLoc);
+  for (const auto &T : *Transformations) {
+    if (auto Err = AC.replace(*Result.SourceManager, T.Range, T.Replacement)) {
+      Consumer(std::move(Err));
+      return;
+    }
+  }
+
+  for (const auto &I : Case.AddedIncludes) {
+    auto &Header = I.first;
+    switch (I.second) {
+      case IncludeFormat::Quoted:
+        AC.addHeader(Header);
+        break;
+      case IncludeFormat::Angled:
+        AC.addHeader((llvm::Twine("<") + Header + ">").str());
+        break;
+    }
+  }
+
+  Consumer(std::move(AC));
+}