Adds the Refactoring library, which is a layer on top of the Tooling library
authorManuel Klimek <klimek@google.com>
Wed, 23 May 2012 16:29:20 +0000 (16:29 +0000)
committerManuel Klimek <klimek@google.com>
Wed, 23 May 2012 16:29:20 +0000 (16:29 +0000)
that allows easy refactoring across translation units.

llvm-svn: 157331

clang/include/clang/Tooling/Refactoring.h [new file with mode: 0644]
clang/lib/Tooling/CMakeLists.txt
clang/lib/Tooling/Refactoring.cpp [new file with mode: 0644]
clang/unittests/CMakeLists.txt
clang/unittests/Tooling/RefactoringTest.cpp [new file with mode: 0644]

diff --git a/clang/include/clang/Tooling/Refactoring.h b/clang/include/clang/Tooling/Refactoring.h
new file mode 100644 (file)
index 0000000..36b8446
--- /dev/null
@@ -0,0 +1,142 @@
+//===--- Refactoring.h - Framework for clang refactoring tools --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Interfaces supporting refactorings that span multiple translation units.
+//  While single translation unit refactorings are supported via the Rewriter,
+//  when refactoring multiple translation units changes must be stored in a
+//  SourceManager independent form, duplicate changes need to be removed, and
+//  all changes must be applied at once at the end of the refactoring so that
+//  the code is always parseable.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringRef.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Tooling/Tooling.h"
+#include <set>
+#include <string>
+
+namespace clang {
+
+class Rewriter;
+class SourceLocation;
+
+namespace tooling {
+
+/// \brief A text replacement.
+///
+/// Represents a SourceManager independent replacement of a range of text in a
+/// specific file.
+class Replacement {
+public:
+  /// \brief Creates an invalid (not applicable) replacement.
+  Replacement();
+
+  /// \brief Creates a replacement of the range [Offset, Offset+Length) in
+  /// FilePath with ReplacementText.
+  ///
+  /// \param FilePath A source file accessible via a SourceManager.
+  /// \param Offset The byte offset of the start of the range in the file.
+  /// \param Length The length of the range in bytes.
+  Replacement(llvm::StringRef FilePath, unsigned Offset,
+              unsigned Length, llvm::StringRef ReplacementText);
+
+  /// \brief Creates a Replacement of the range [Start, Start+Length) with
+  /// ReplacementText.
+  Replacement(SourceManager &Sources, SourceLocation Start, unsigned Length,
+              llvm::StringRef ReplacementText);
+
+  /// \brief Creates a Replacement of the given range with ReplacementText.
+  Replacement(SourceManager &Sources, const CharSourceRange &Range,
+              llvm::StringRef ReplacementText);
+
+  /// \brief Creates a Replacement of the node with ReplacementText.
+  template <typename Node>
+  Replacement(SourceManager &Sources, const Node &NodeToReplace,
+              llvm::StringRef ReplacementText);
+
+  /// \brief Returns whether this replacement can be applied to a file.
+  ///
+  /// Only replacements that are in a valid file can be applied.
+  bool isApplicable() const;
+
+  /// \brief Accessors.
+  /// @{
+  std::string getFilePath() const { return FilePath; }
+  unsigned getOffset() const { return Offset; }
+  unsigned getLength() const { return Length; }
+  /// @}
+
+  /// \brief Applies the replacement on the Rewriter.
+  bool apply(Rewriter &Rewrite) const;
+
+  /// \brief Comparator to be able to use Replacement in std::set for uniquing.
+  class Less {
+  public:
+    bool operator()(const Replacement &R1, const Replacement &R2) const;
+  };
+
+ private:
+  void setFromSourceLocation(SourceManager &Sources, SourceLocation Start,
+                             unsigned Length, llvm::StringRef ReplacementText);
+  void setFromSourceRange(SourceManager &Sources, const CharSourceRange &Range,
+                          llvm::StringRef ReplacementText);
+
+  std::string FilePath;
+  unsigned Offset;
+  unsigned Length;
+  std::string ReplacementText;
+};
+
+/// \brief A set of Replacements.
+/// FIXME: Change to a vector and deduplicate in the RefactoringTool.
+typedef std::set<Replacement, Replacement::Less> Replacements;
+
+/// \brief Apply all replacements on the Rewriter.
+///
+/// If at least one Apply returns false, ApplyAll returns false. Every
+/// Apply will be executed independently of the result of other
+/// Apply operations.
+bool applyAllReplacements(Replacements &Replaces, Rewriter &Rewrite);
+
+/// \brief A tool to run refactorings.
+///
+/// This is a refactoring specific version of \see ClangTool.
+/// All text replacements added to getReplacements() during the run of the
+/// tool will be applied and saved after all translation units have been
+/// processed.
+class RefactoringTool {
+public:
+  /// \see ClangTool::ClangTool.
+  RefactoringTool(const CompilationDatabase &Compilations,
+                  ArrayRef<std::string> SourcePaths);
+
+  /// \brief Returns a set of replacements. All replacements added during the
+  /// run of the tool will be applied after all translation units have been
+  /// processed.
+  Replacements &getReplacements();
+
+  /// \see ClangTool::run.
+  int run(FrontendActionFactory *ActionFactory);
+
+private:
+  ClangTool Tool;
+  Replacements Replace;
+};
+
+template <typename Node>
+Replacement::Replacement(SourceManager &Sources, const Node &NodeToReplace,
+                         llvm::StringRef ReplacementText) {
+  const CharSourceRange Range =
+      CharSourceRange::getTokenRange(NodeToReplace->getSourceRange());
+  setFromSourceRange(Sources, Range, ReplacementText);
+}
+
+} // end namespace tooling
+} // end namespace clang
index 6604551..aada617 100644 (file)
@@ -1,8 +1,9 @@
 set(LLVM_LINK_COMPONENTS support)
-SET(LLVM_USED_LIBS clangBasic clangFrontend clangAST)
+SET(LLVM_USED_LIBS clangBasic clangFrontend clangAST clangRewrite)
 
 add_clang_library(clangTooling
   CompilationDatabase.cpp
+  Refactoring.cpp
   Tooling.cpp
   ArgumentsAdjusters.cpp
   )
diff --git a/clang/lib/Tooling/Refactoring.cpp b/clang/lib/Tooling/Refactoring.cpp
new file mode 100644 (file)
index 0000000..6e90ba0
--- /dev/null
@@ -0,0 +1,178 @@
+//===--- Refactoring.cpp - Framework for clang refactoring tools ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Implements tools to support refactorings.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Rewrite/Rewriter.h"
+#include "clang/Tooling/Refactoring.h"
+#include "llvm/Support/raw_os_ostream.h"
+
+namespace clang {
+namespace tooling {
+
+static const char * const InvalidLocation = "";
+
+Replacement::Replacement()
+  : FilePath(InvalidLocation), Offset(0), Length(0) {}
+
+Replacement::Replacement(llvm::StringRef FilePath, unsigned Offset,
+                         unsigned Length, llvm::StringRef ReplacementText)
+  : FilePath(FilePath), Offset(Offset),
+    Length(Length), ReplacementText(ReplacementText) {}
+
+Replacement::Replacement(SourceManager &Sources, SourceLocation Start,
+                         unsigned Length, llvm::StringRef ReplacementText) {
+  setFromSourceLocation(Sources, Start, Length, ReplacementText);
+}
+
+Replacement::Replacement(SourceManager &Sources, const CharSourceRange &Range,
+                         llvm::StringRef ReplacementText) {
+  setFromSourceRange(Sources, Range, ReplacementText);
+}
+
+bool Replacement::isApplicable() const {
+  return FilePath != InvalidLocation;
+}
+
+bool Replacement::apply(Rewriter &Rewrite) const {
+  SourceManager &SM = Rewrite.getSourceMgr();
+  const FileEntry *Entry = SM.getFileManager().getFile(FilePath);
+  if (Entry == NULL)
+    return false;
+  FileID ID;
+  // FIXME: Use SM.translateFile directly.
+  SourceLocation Location = SM.translateFileLineCol(Entry, 1, 1);
+  ID = Location.isValid() ?
+    SM.getFileID(Location) :
+    SM.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
+  // FIXME: We cannot check whether Offset + Length is in the file, as
+  // the remapping API is not public in the RewriteBuffer.
+  const SourceLocation Start =
+    SM.getLocForStartOfFile(ID).
+    getLocWithOffset(Offset);
+  // ReplaceText returns false on success.
+  // ReplaceText only fails if the source location is not a file location, in
+  // which case we already returned false earlier.
+  bool RewriteSucceeded = !Rewrite.ReplaceText(Start, Length, ReplacementText);
+  assert(RewriteSucceeded);
+  return RewriteSucceeded;
+}
+
+bool Replacement::Less::operator()(const Replacement &R1,
+                                   const Replacement &R2) const {
+  if (R1.FilePath != R2.FilePath) return R1.FilePath < R2.FilePath;
+  if (R1.Offset != R2.Offset) return R1.Offset < R2.Offset;
+  if (R1.Length != R2.Length) return R1.Length < R2.Length;
+  return R1.ReplacementText < R2.ReplacementText;
+}
+
+void Replacement::setFromSourceLocation(SourceManager &Sources,
+                                        SourceLocation Start, unsigned Length,
+                                        llvm::StringRef ReplacementText) {
+  const std::pair<FileID, unsigned> DecomposedLocation =
+      Sources.getDecomposedLoc(Start);
+  const FileEntry *Entry = Sources.getFileEntryForID(DecomposedLocation.first);
+  this->FilePath = Entry != NULL ? Entry->getName() : InvalidLocation;
+  this->Offset = DecomposedLocation.second;
+  this->Length = Length;
+  this->ReplacementText = ReplacementText;
+}
+
+// FIXME: This should go into the Lexer, but we need to figure out how
+// to handle ranges for refactoring in general first - there is no obvious
+// good way how to integrate this into the Lexer yet.
+static int getRangeSize(SourceManager &Sources, const CharSourceRange &Range) {
+  SourceLocation SpellingBegin = Sources.getSpellingLoc(Range.getBegin());
+  SourceLocation SpellingEnd = Sources.getSpellingLoc(Range.getEnd());
+  std::pair<FileID, unsigned> Start = Sources.getDecomposedLoc(SpellingBegin);
+  std::pair<FileID, unsigned> End = Sources.getDecomposedLoc(SpellingEnd);
+  if (Start.first != End.first) return -1;
+  if (Range.isTokenRange())
+    End.second += Lexer::MeasureTokenLength(SpellingEnd, Sources,
+                                            LangOptions());
+  return End.second - Start.second;
+}
+
+void Replacement::setFromSourceRange(SourceManager &Sources,
+                                     const CharSourceRange &Range,
+                                     llvm::StringRef ReplacementText) {
+  setFromSourceLocation(Sources, Sources.getSpellingLoc(Range.getBegin()),
+                        getRangeSize(Sources, Range), ReplacementText);
+}
+
+bool applyAllReplacements(Replacements &Replaces, Rewriter &Rewrite) {
+  bool Result = true;
+  for (Replacements::const_iterator I = Replaces.begin(),
+                                    E = Replaces.end();
+       I != E; ++I) {
+    if (I->isApplicable()) {
+      Result = I->apply(Rewrite) && Result;
+    } else {
+      Result = false;
+    }
+  }
+  return Result;
+}
+
+bool saveRewrittenFiles(Rewriter &Rewrite) {
+  for (Rewriter::buffer_iterator I = Rewrite.buffer_begin(),
+                                 E = Rewrite.buffer_end();
+       I != E; ++I) {
+    // FIXME: This code is copied from the FixItRewriter.cpp - I think it should
+    // go into directly into Rewriter (there we also have the Diagnostics to
+    // handle the error cases better).
+    const FileEntry *Entry =
+        Rewrite.getSourceMgr().getFileEntryForID(I->first);
+    std::string ErrorInfo;
+    llvm::raw_fd_ostream FileStream(
+        Entry->getName(), ErrorInfo, llvm::raw_fd_ostream::F_Binary);
+    if (!ErrorInfo.empty())
+      return false;
+    I->second.write(FileStream);
+    FileStream.flush();
+  }
+  return true;
+}
+
+RefactoringTool::RefactoringTool(const CompilationDatabase &Compilations,
+                                 ArrayRef<std::string> SourcePaths)
+  : Tool(Compilations, SourcePaths) {}
+
+Replacements &RefactoringTool::getReplacements() { return Replace; }
+
+int RefactoringTool::run(FrontendActionFactory *ActionFactory) {
+  int Result = Tool.run(ActionFactory);
+  LangOptions DefaultLangOptions;
+  DiagnosticOptions DefaultDiagnosticOptions;
+  TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(),
+                                          DefaultDiagnosticOptions);
+  DiagnosticsEngine Diagnostics(
+      llvm::IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()),
+      &DiagnosticPrinter, false);
+  SourceManager Sources(Diagnostics, Tool.getFiles());
+  Rewriter Rewrite(Sources, DefaultLangOptions);
+  if (!applyAllReplacements(Replace, Rewrite)) {
+    llvm::errs() << "Skipped some replacements.\n";
+  }
+  if (!saveRewrittenFiles(Rewrite)) {
+    llvm::errs() << "Could not save rewritten files.\n";
+    return 1;
+  }
+  return Result;
+}
+
+} // end namespace tooling
+} // end namespace clang
index 541387d..6e45aba 100644 (file)
@@ -70,6 +70,7 @@ add_clang_unittest(Tooling
   Tooling/CompilationDatabaseTest.cpp
   Tooling/ToolingTest.cpp
   Tooling/RecursiveASTVisitorTest.cpp
+  Tooling/RefactoringTest.cpp
   Tooling/RewriterTest.cpp
   USED_LIBS gtest gtest_main clangAST clangTooling clangRewrite
  )
diff --git a/clang/unittests/Tooling/RefactoringTest.cpp b/clang/unittests/Tooling/RefactoringTest.cpp
new file mode 100644 (file)
index 0000000..931c761
--- /dev/null
@@ -0,0 +1,304 @@
+//===- unittest/Tooling/RefactoringTest.cpp - Refactoring unit tests ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RewriterTestContext.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclGroup.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Tooling/Refactoring.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Rewrite/Rewriter.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tooling {
+
+class ReplacementTest : public ::testing::Test {
+ protected:
+  Replacement createReplacement(SourceLocation Start, unsigned Length,
+                                llvm::StringRef ReplacementText) {
+    return Replacement(Context.Sources, Start, Length, ReplacementText);
+  }
+
+  RewriterTestContext Context;
+};
+
+TEST_F(ReplacementTest, CanDeleteAllText) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "text");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 4, ""));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanDeleteAllTextInTextWithNewlines) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "line1\nline2\nline3");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 17, ""));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanAddText) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 0, "result"));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("result", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanReplaceTextAtPosition) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  SourceLocation Location = Context.getLocation(ID, 2, 3);
+  Replacement Replace(createReplacement(Location, 12, "x"));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlixne4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanReplaceTextAtPositionMultipleTimes) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  SourceLocation Location1 = Context.getLocation(ID, 2, 3);
+  Replacement Replace1(createReplacement(Location1, 12, "x\ny\n"));
+  EXPECT_TRUE(Replace1.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlix\ny\nne4", Context.getRewrittenText(ID));
+
+  // Since the original source has not been modified, the (4, 4) points to the
+  // 'e' in the original content.
+  SourceLocation Location2 = Context.getLocation(ID, 4, 4);
+  Replacement Replace2(createReplacement(Location2, 1, "f"));
+  EXPECT_TRUE(Replace2.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlix\ny\nnf4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, ApplyFailsForNonExistentLocation) {
+  Replacement Replace("nonexistent-file.cpp", 0, 1, "");
+  EXPECT_FALSE(Replace.apply(Context.Rewrite));
+}
+
+TEST_F(ReplacementTest, CanRetrivePath) {
+  Replacement Replace("/path/to/file.cpp", 0, 1, "");
+  EXPECT_EQ("/path/to/file.cpp", Replace.getFilePath());
+}
+
+TEST_F(ReplacementTest, ReturnsInvalidPath) {
+  Replacement Replace1(Context.Sources, SourceLocation(), 0, "");
+  EXPECT_TRUE(Replace1.getFilePath().empty());
+
+  Replacement Replace2;
+  EXPECT_TRUE(Replace2.getFilePath().empty());
+}
+
+TEST_F(ReplacementTest, CanApplyReplacements) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 3, 1),
+                              5, "other"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("line1\nreplaced\nother\nline4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, SkipsDuplicateReplacements) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("line1\nreplaced\nline3\nline4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, ApplyAllFailsIfOneApplyFails) {
+  // This test depends on the value of the file name of an invalid source
+  // location being in the range ]a, z[.
+  FileID IDa = Context.createInMemoryFile("a.cpp", "text");
+  FileID IDz = Context.createInMemoryFile("z.cpp", "text");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(IDa, 1, 1),
+                              4, "a"));
+  Replaces.insert(Replacement(Context.Sources, SourceLocation(),
+                              5, "2"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(IDz, 1, 1),
+                              4, "z"));
+  EXPECT_FALSE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("a", Context.getRewrittenText(IDa));
+  EXPECT_EQ("z", Context.getRewrittenText(IDz));
+}
+
+class FlushRewrittenFilesTest : public ::testing::Test {
+ public:
+  FlushRewrittenFilesTest() {
+    std::string ErrorInfo;
+    TemporaryDirectory = llvm::sys::Path::GetTemporaryDirectory(&ErrorInfo);
+    assert(ErrorInfo.empty());
+  }
+
+  ~FlushRewrittenFilesTest() {
+    std::string ErrorInfo;
+    TemporaryDirectory.eraseFromDisk(true, &ErrorInfo);
+    assert(ErrorInfo.empty());
+  }
+
+  FileID createFile(llvm::StringRef Name, llvm::StringRef Content) {
+    llvm::SmallString<1024> Path(TemporaryDirectory.str());
+    llvm::sys::path::append(Path, Name);
+    std::string ErrorInfo;
+    llvm::raw_fd_ostream OutStream(Path.c_str(),
+                                   ErrorInfo, llvm::raw_fd_ostream::F_Binary);
+    assert(ErrorInfo.empty());
+    OutStream << Content;
+    OutStream.close();
+    const FileEntry *File = Context.Files.getFile(Path);
+    assert(File != NULL);
+    return Context.Sources.createFileID(File, SourceLocation(), SrcMgr::C_User);
+  }
+
+  std::string getFileContentFromDisk(llvm::StringRef Name) {
+    llvm::SmallString<1024> Path(TemporaryDirectory.str());
+    llvm::sys::path::append(Path, Name);
+    // We need to read directly from the FileManager without relaying through
+    // a FileEntry, as otherwise we'd read through an already opened file
+    // descriptor, which might not see the changes made.
+    // FIXME: Figure out whether there is a way to get the SourceManger to
+    // reopen the file.
+    return Context.Files.getBufferForFile(Path, NULL)->getBuffer();
+  }
+
+  llvm::sys::Path TemporaryDirectory;
+  RewriterTestContext Context;
+};
+
+TEST_F(FlushRewrittenFilesTest, StoresChangesOnDisk) {
+  FileID ID = createFile("input.cpp", "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_FALSE(Context.Rewrite.overwriteChangedFiles());
+  EXPECT_EQ("line1\nreplaced\nline3\nline4",
+            getFileContentFromDisk("input.cpp"));
+}
+
+namespace {
+template <typename T>
+class TestVisitor : public clang::RecursiveASTVisitor<T> {
+public:
+  bool runOver(StringRef Code) {
+    return runToolOnCode(new TestAction(this), Code);
+  }
+
+protected:
+  clang::SourceManager *SM;
+
+private:
+  class FindConsumer : public clang::ASTConsumer {
+  public:
+    FindConsumer(TestVisitor *Visitor) : Visitor(Visitor) {}
+
+    virtual void HandleTranslationUnit(clang::ASTContext &Context) {
+      Visitor->TraverseDecl(Context.getTranslationUnitDecl());
+    }
+
+  private:
+    TestVisitor *Visitor;
+  };
+
+  class TestAction : public clang::ASTFrontendAction {
+  public:
+    TestAction(TestVisitor *Visitor) : Visitor(Visitor) {}
+
+    virtual clang::ASTConsumer* CreateASTConsumer(
+        clang::CompilerInstance& compiler, llvm::StringRef dummy) {
+      Visitor->SM = &compiler.getSourceManager();
+      /// TestConsumer will be deleted by the framework calling us.
+      return new FindConsumer(Visitor);
+    }
+
+  private:
+    TestVisitor *Visitor;
+  };
+};
+} // end namespace
+
+void expectReplacementAt(const Replacement &Replace,
+                         StringRef File, unsigned Offset, unsigned Length) {
+  ASSERT_TRUE(Replace.isApplicable());
+  EXPECT_EQ(File, Replace.getFilePath());
+  EXPECT_EQ(Offset, Replace.getOffset());
+  EXPECT_EQ(Length, Replace.getLength());
+}
+
+class ClassDeclXVisitor : public TestVisitor<ClassDeclXVisitor> {
+public:
+  bool VisitCXXRecordDecl(CXXRecordDecl *Record) {
+    if (Record->getName() == "X") {
+      Replace = Replacement(*SM, Record, "");
+    }
+    return true;
+  }
+  Replacement Replace;
+};
+
+TEST(Replacement, CanBeConstructedFromNode) {
+  ClassDeclXVisitor ClassDeclX;
+  EXPECT_TRUE(ClassDeclX.runOver("     class X;"));
+  expectReplacementAt(ClassDeclX.Replace, "input.cc", 5, 7);
+}
+
+TEST(Replacement, ReplacesAtSpellingLocation) {
+  ClassDeclXVisitor ClassDeclX;
+  EXPECT_TRUE(ClassDeclX.runOver("#define A(Y) Y\nA(class X);"));
+  expectReplacementAt(ClassDeclX.Replace, "input.cc", 17, 7);
+}
+
+class CallToFVisitor : public TestVisitor<CallToFVisitor> {
+public:
+  bool VisitCallExpr(CallExpr *Call) {
+    if (Call->getDirectCallee()->getName() == "F") {
+      Replace = Replacement(*SM, Call, "");
+    }
+    return true;
+  }
+  Replacement Replace;
+};
+
+TEST(Replacement, FunctionCall) {
+  CallToFVisitor CallToF;
+  EXPECT_TRUE(CallToF.runOver("void F(); void G() { F(); }"));
+  expectReplacementAt(CallToF.Replace, "input.cc", 21, 3);
+}
+
+TEST(Replacement, TemplatedFunctionCall) {
+  CallToFVisitor CallToF;
+  EXPECT_TRUE(CallToF.runOver(
+        "template <typename T> void F(); void G() { F<int>(); }"));
+  expectReplacementAt(CallToF.Replace, "input.cc", 43, 8);
+}
+
+} // end namespace tooling
+} // end namespace clang