[clang-move] Enable dump all declarations in old header.

[hokein]

Summary

• Add -dump_dels option to dump all declarations from old header. It will allow clang-move used as a frontend to get declarations from header. Further more, this will make debugging stuff easier.Currently only support dumpng class/function types.
• Refactoring code a little bit by creating a ClangMoveContext which holds all options for ClangMoveTool, which can simplify the code in some degree.

[hokein]

Code style.

[ioeric]

clang-move/ClangMove.h

90

Is this the right place for this comment? Seems a bit unexpected.

unittests/clang-move/ClangMoveTests.cpp

522

What if Reporter.getDeclarationList().size() > ExpectedDeclaration.size().

I'd use iterator-based loop on both vectors and assert both iterators reached end after loop.

[hokein]

Add comments && Update test.

[ioeric]

LG with a nit.

clang-move/tool/ClangMoveMain.cpp

155

This check is run in each iteration... maybe just loop from begin() to end()-1 and special casing the last element, in which case you don't need to check in each run.

clang-move/ClangMove.h

 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 namespace clang {
 namespace move {
 
-// FIXME: Make it support more types, e.g. function definitions.
-// Currently only support moving class definition.
-//
-// When moving all class declarations in old header, all code in old.h/cc will
-// be moved.
-class ClangMoveTool : public ast_matchers::MatchFinder::MatchCallback {
+// A reporter which collects and reports declarations in old header.
+class DeclarationReporter {
 public:
-  // Information about the declaration being moved.
-  struct MovedDecl {
-    // FIXME: Replace Decl with SourceRange to get rid of calculating range for
-    // the Decl duplicately.
-    const clang::NamedDecl *Decl = nullptr;
-    clang::SourceManager *SM = nullptr;
-    MovedDecl() = default;
-    MovedDecl(const clang::NamedDecl *Decl, clang::SourceManager *SM)
-        : Decl(Decl), SM(SM) {}
+  DeclarationReporter() = default;
+  ~DeclarationReporter() = default;
+
+  void reportDeclaration(llvm::StringRef DeclarationName,
+                         llvm::StringRef Type) {
+    DeclarationList.emplace_back(DeclarationName, Type);
   };
 
-  struct MoveDefinitionSpec {
-    // The list of fully qualified names, e.g. Foo, a::Foo, b::Foo.
-    SmallVector<std::string, 4> Names;
-    // The file path of old header, can be relative path and absolute path.
-    std::string OldHeader;
-    // The file path of old cc, can be relative path and absolute path.
-    std::string OldCC;
-    // The file path of new header, can be relative path and absolute path.
-    std::string NewHeader;
-    // The file path of new cc, can be relative path and absolute path.
-    std::string NewCC;
-    // Whether old.h depends on new.h. If true, #include "new.h" will be added
-    // in old.h.
-    bool OldDependOnNew = false;
-    // Whether new.h depends on old.h. If true, #include "old.h" will be added
-    // in new.h.
-    bool NewDependOnOld = false;
-  };
+  // A <DeclarationName, DeclarationKind> pair.
+  // The DeclarationName is a fully qualified name for the declaration, like
+  // A::B::Foo. The DeclarationKind is a string represents the kind of the
+  // declaration, currently only "Function" and "Class" are supported.
+  typedef std::pair<std::string, std::string> DeclarationPair;
+
+  const std::vector<DeclarationPair> getDeclarationList() const {
+    return DeclarationList;
+  }
+
+private:
+  std::vector<DeclarationPair> DeclarationList;
+};
+
+// Specify declarations being moved. It contains all information of the moved
+// declarations.
 
-  ClangMoveTool(
-      const MoveDefinitionSpec &MoveSpec,
-      std::map<std::string, tooling::Replacements> &FileToReplacements,
-      llvm::StringRef OriginalRunningDirectory, llvm::StringRef Style);
+// A Context which contains extra options which are used in ClangMoveTool.
+struct ClangMoveContext {
+  MoveDefinitionSpec Spec;
+  // The Key is file path, value is the replacements being applied to the file.
+  std::map<std::string, tooling::Replacements> &FileToReplacements;
+  // The original working directory where the local clang-move binary runs.
+  //
+  // clang-move will change its current working directory to the build
+  // directory when analyzing the source file. We save the original working
+  // directory in order to get the absolute file path for the fields in Spec.
+  std::string OriginalRunningDirectory;
+  // The name of a predefined code style.
+  std::string FallbackStyle;
+  // Whether dump all declarations in old header.
+  bool DumpDeclarations;
+};
+
+// When moving all declarations in old header, all code in old.h/cc will be
+// moved.
+class ClangMoveTool : public ast_matchers::MatchFinder::MatchCallback {
+public:
+  // Information about the declaration being moved.
+  struct MovedDecl {
+    // FIXME: Replace Decl with SourceRange to get rid of calculating range for
+    // the Decl duplicately.
+    const clang::NamedDecl *Decl = nullptr;
+    clang::SourceManager *SM = nullptr;
+    MovedDecl() = default;
+    MovedDecl(const clang::NamedDecl *Decl, clang::SourceManager *SM)
+        : Decl(Decl), SM(SM) {}
+  };
+
+  ClangMoveTool(ClangMoveContext *const Context,
+                DeclarationReporter *const Reporter);
 
   void registerMatchers(ast_matchers::MatchFinder *Finder);
 
   void run(const ast_matchers::MatchFinder::MatchResult &Result) override;
 
   void onEndOfTranslationUnit() override;
 
   /// Add #includes from old.h/cc files.
   ///
   /// \param IncludeHeader The name of the file being included, as written in
   /// the source code.
   /// \param IsAngled Whether the file name was enclosed in angle brackets.
   /// \param SearchPath The search path which was used to find the IncludeHeader
   /// in the file system. It can be a relative path or an absolute path.
   /// \param FileName The name of file where the IncludeHeader comes from.
-  /// \param IncludeFilenameRange The source range for the written file name in #include
-  ///  (i.e. "old.h" for #include "old.h") in old.cc.
+  /// \param IncludeFilenameRange The source range for the written file name in
+  /// #include (i.e. "old.h" for #include "old.h") in old.cc.
   /// \param SM The SourceManager.
   void addIncludes(llvm::StringRef IncludeHeader, bool IsAngled,
                    llvm::StringRef SearchPath, llvm::StringRef FileName,
                    clang::CharSourceRange IncludeFilenameRange,
                    const SourceManager &SM);
 
   std::vector<MovedDecl> &getMovedDecls() { return MovedDecls; }
 
private:
   // Make the Path absolute using the OrignalRunningDirectory if the Path is not
   // an absolute path. An empty Path will result in an empty string.
   std::string makeAbsolutePath(StringRef Path);
 
   void removeClassDefinitionInOldFiles();
   void moveClassDefinitionToNewFiles();
   void moveAll(SourceManager& SM, StringRef OldFile, StringRef NewFile);
 
-  MoveDefinitionSpec Spec;
   // Stores all MatchCallbacks created by this tool.
   std::vector<std::unique_ptr<ast_matchers::MatchFinder::MatchCallback>>
       MatchCallbacks;
-  // The Key is file path, value is the replacements being applied to the file.
-  std::map<std::string, tooling::Replacements> &FileToReplacements;
   // All declarations (the class decl being moved, forward decls) that need to
   // be moved/copy to the new files, saving in an AST-visited order.
   std::vector<MovedDecl> MovedDecls;
   // The declarations that needs to be removed in old.cc/h.
   std::vector<MovedDecl> RemovedDecls;
   // The #includes in old_header.h.
   std::vector<std::string> HeaderIncludes;
   // The #includes in old_cc.cc.
   std::vector<std::string> CCIncludes;
-  // The original working directory where the local clang-move binary runs.
-  //
-  // clang-move will change its current working directory to the build
-  // directory when analyzing the source file. We save the original working
-  // directory in order to get the absolute file path for the fields in Spec.
-  std::string OriginalRunningDirectory;
-  // The name of a predefined code style.
-  std::string FallbackStyle;
   // The unmoved named declarations in old header.
   llvm::SmallPtrSet<const NamedDecl*, 8> UnremovedDeclsInOldHeader;
   /// The source range for the written file name in #include (i.e. "old.h" for
   /// #include "old.h") in old.cc,  including the enclosing quotes or angle
   /// brackets.
   clang::CharSourceRange OldHeaderIncludeRange;
   /// Mapping from FilePath to FileID, which can be used in post processes like
   /// cleanup around replacements.
   llvm::StringMap<FileID> FilePathToFileID;
+  /// A context contains all running options. It is not owned.
+  ClangMoveContext *const Context;
+  /// A reporter to report all declarations from old header. It is not owned.
+  DeclarationReporter *const Reporter;
 };
 
 class ClangMoveAction : public clang::ASTFrontendAction {
 public:
-  ClangMoveAction(
-      const ClangMoveTool::MoveDefinitionSpec &spec,
-      std::map<std::string, tooling::Replacements> &FileToReplacements,
-      llvm::StringRef OriginalRunningDirectory, llvm::StringRef FallbackStyle)
-      : MoveTool(spec, FileToReplacements, OriginalRunningDirectory,
-                 FallbackStyle) {
+  ClangMoveAction(ClangMoveContext *const Context,
+                  DeclarationReporter *const Reporter)
+      : MoveTool(Context, Reporter) {
     MoveTool.registerMatchers(&MatchFinder);
   }
 
   ~ClangMoveAction() override = default;
 
   std::unique_ptr<clang::ASTConsumer>
   CreateASTConsumer(clang::CompilerInstance &Compiler,
                     llvm::StringRef InFile) override;
 
 private:
   ast_matchers::MatchFinder MatchFinder;
   ClangMoveTool MoveTool;
 };
 
 class ClangMoveActionFactory : public tooling::FrontendActionFactory {
 public:
-  ClangMoveActionFactory(
-      const ClangMoveTool::MoveDefinitionSpec &Spec,
-      std::map<std::string, tooling::Replacements> &FileToReplacements,
-      llvm::StringRef OriginalRunningDirectory, llvm::StringRef FallbackStyle)
-      : Spec(Spec), FileToReplacements(FileToReplacements),
-        OriginalRunningDirectory(OriginalRunningDirectory),
-        FallbackStyle(FallbackStyle) {}
+  ClangMoveActionFactory(ClangMoveContext *const Context,
+                         DeclarationReporter *const Reporter = nullptr)
+      : Context(Context), Reporter(Reporter) {}
 
   clang::FrontendAction *create() override {
-    return new ClangMoveAction(Spec, FileToReplacements,
-                               OriginalRunningDirectory, FallbackStyle);
+    return new ClangMoveAction(Context, Reporter);
   }
 
 private:
-  const ClangMoveTool::MoveDefinitionSpec &Spec;
-  std::map<std::string, tooling::Replacements> &FileToReplacements;
-  std::string OriginalRunningDirectory;
-  std::string FallbackStyle;
+  // Not owned.
+  ClangMoveContext* const Context;
+  DeclarationReporter *const Reporter;
 };
 
 } // namespace move
 } // namespace clang
 
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_MOVE_CLANGMOVE_H

clang-move/ClangMove.cpp

 ClangMoveAction::CreateASTConsumer(clang::CompilerInstance &Compiler,
                                    StringRef /*InFile*/) {
   Compiler.getPreprocessor().addPPCallbacks(llvm::make_unique<FindAllIncludes>(
       &Compiler.getSourceManager(), &MoveTool));
   return MatchFinder.newASTConsumer();
 }
 
 ClangMoveTool::ClangMoveTool(
-    const MoveDefinitionSpec &MoveSpec,
-    std::map<std::string, tooling::Replacements> &FileToReplacements,
-    llvm::StringRef OriginalRunningDirectory, llvm::StringRef FallbackStyle)
-    : Spec(MoveSpec), FileToReplacements(FileToReplacements),
-      OriginalRunningDirectory(OriginalRunningDirectory),
-      FallbackStyle(FallbackStyle) {
-  if (!Spec.NewHeader.empty())
-    CCIncludes.push_back("#include \"" + Spec.NewHeader + "\"\n");
+    ClangMoveContext *const Context,
+    DeclarationReporter *const Reporter)
+    : Context(Context),
+      Reporter(Reporter) {
+  if (!Context->Spec.NewHeader.empty())
+    CCIncludes.push_back("#include \"" + Context->Spec.NewHeader + "\"\n");
 }
 
 void ClangMoveTool::addRemovedDecl(const MovedDecl &Decl) {
   const auto &SM = *Decl.SM;
   auto Loc = Decl.Decl->getLocation();
   StringRef FilePath = SM.getFilename(Loc);
   FilePathToFileID[FilePath] = SM.getFileID(Loc);
   RemovedDecls.push_back(Decl);
 }
 
 void ClangMoveTool::registerMatchers(ast_matchers::MatchFinder *Finder) {
-  Optional<ast_matchers::internal::Matcher<NamedDecl>> HasAnySymbolNames;
-  for (StringRef SymbolName: Spec.Names) {
-    llvm::StringRef GlobalSymbolName = SymbolName.trim().ltrim(':');
-    const auto HasName = hasName(("::" + GlobalSymbolName).str());
-    HasAnySymbolNames =
-        HasAnySymbolNames ? anyOf(*HasAnySymbolNames, HasName) : HasName;
-  }
-  if (!HasAnySymbolNames) {
-    llvm::errs() << "No symbols being moved.\n";
-    return;
-  }
-
-  auto InOldHeader = isExpansionInFile(makeAbsolutePath(Spec.OldHeader));
-  auto InOldCC = isExpansionInFile(makeAbsolutePath(Spec.OldCC));
+  auto InOldHeader =
+      isExpansionInFile(makeAbsolutePath(Context->Spec.OldHeader));
+  auto InOldCC = isExpansionInFile(makeAbsolutePath(Context->Spec.OldCC));
   auto InOldFiles = anyOf(InOldHeader, InOldCC);
-  auto InMovedClass =
-      hasOutermostEnclosingClass(cxxRecordDecl(*HasAnySymbolNames));
-
   auto ForwardDecls =
       cxxRecordDecl(unless(anyOf(isImplicit(), isDefinition())));
 
   //============================================================================
   // Matchers for old header
   //============================================================================
   // Match all top-level named declarations (e.g. function, variable, enum) in
   // old header, exclude forward class declarations and namespace declarations.
   //
-  // The old header which contains only one declaration being moved and forward
-  // declarations is considered to be moved totally.
+  // We consider declarations inside a class belongs to the class. So these
+  // declarations will be ignored.
   auto AllDeclsInHeader = namedDecl(
       unless(ForwardDecls), unless(namespaceDecl()),
       unless(usingDirectiveDecl()), // using namespace decl.
       unless(classTemplateDecl(has(ForwardDecls))), // template forward decl.
       InOldHeader,
-      hasParent(decl(anyOf(namespaceDecl(), translationUnitDecl()))));
+      hasParent(decl(anyOf(namespaceDecl(), translationUnitDecl()))),
+      hasDeclContext(decl(anyOf(namespaceDecl(), translationUnitDecl()))));
   Finder->addMatcher(AllDeclsInHeader.bind("decls_in_header"), this);
+
+  // Don't register other matchers when dumping all declarations in header.
+  if (Context->DumpDeclarations) return;
+
   // Match forward declarations in old header.
   Finder->addMatcher(namedDecl(ForwardDecls, InOldHeader).bind("fwd_decl"),
                      this);
 
   //============================================================================
   // Matchers for old cc
   //============================================================================
   auto InOldCCNamedOrGlobalNamespace =
Finder->addMatcher(
       this);
 
   // Match anonymous namespace decl in old cc.
   Finder->addMatcher(namespaceDecl(isAnonymous(), InOldCC).bind("anonymous_ns"),
                      this);
 
   // Match static functions/variable definitions which are defined in named
   // namespaces.
+  Optional<ast_matchers::internal::Matcher<NamedDecl>> HasAnySymbolNames;
+  for (StringRef SymbolName: Context->Spec.Names) {
+    llvm::StringRef GlobalSymbolName = SymbolName.trim().ltrim(':');
+    const auto HasName = hasName(("::" + GlobalSymbolName).str());
+    HasAnySymbolNames =
+        HasAnySymbolNames ? anyOf(*HasAnySymbolNames, HasName) : HasName;
+  }
+
+  if (!HasAnySymbolNames) {
+    llvm::errs() << "No symbols being moved.\n";
+    return;
+  }
+  auto InMovedClass =
+      hasOutermostEnclosingClass(cxxRecordDecl(*HasAnySymbolNames));
   auto IsOldCCStaticDefinition =
       allOf(isDefinition(), unless(InMovedClass), InOldCCNamedOrGlobalNamespace,
             isStaticStorageClass());
   Finder->addMatcher(namedDecl(anyOf(functionDecl(IsOldCCStaticDefinition),
                                      varDecl(IsOldCCStaticDefinition)))
                          .bind("static_decls"),
                      this);
 
if (const auto *D =
     MovedDecls.emplace_back(ND, &Result.Context->getSourceManager());
   } else if (const auto *UD =
                  Result.Nodes.getNodeAs<clang::NamedDecl>("using_decl")) {
     MovedDecls.emplace_back(UD, &Result.Context->getSourceManager());
   }
 }
 
 std::string ClangMoveTool::makeAbsolutePath(StringRef Path) {
-  return MakeAbsolutePath(OriginalRunningDirectory, Path);
+  return MakeAbsolutePath(Context->OriginalRunningDirectory, Path);
 }
 
 void ClangMoveTool::addIncludes(llvm::StringRef IncludeHeader, bool IsAngled,
                                 llvm::StringRef SearchPath,
                                 llvm::StringRef FileName,
                                 clang::CharSourceRange IncludeFilenameRange,
                                 const SourceManager &SM) {
   SmallVector<char, 128> HeaderWithSearchPath;
   llvm::sys::path::append(HeaderWithSearchPath, SearchPath, IncludeHeader);
-  std::string AbsoluteOldHeader = makeAbsolutePath(Spec.OldHeader);
+  std::string AbsoluteOldHeader = makeAbsolutePath(Context->Spec.OldHeader);
   // FIXME: Add old.h to the new.cc/h when the new target has dependencies on
   // old.h/c. For instance, when moved class uses another class defined in
   // old.h, the old.h should be added in new.h.
   if (AbsoluteOldHeader ==
       MakeAbsolutePath(SM, llvm::StringRef(HeaderWithSearchPath.data(),
                                            HeaderWithSearchPath.size()))) {
     OldHeaderIncludeRange = IncludeFilenameRange;
     return;
   }
 
   std::string IncludeLine =
       IsAngled ? ("#include <" + IncludeHeader + ">\n").str()
                : ("#include \"" + IncludeHeader + "\"\n").str();
 
   std::string AbsoluteCurrentFile = MakeAbsolutePath(SM, FileName);
   if (AbsoluteOldHeader == AbsoluteCurrentFile) {
     HeaderIncludes.push_back(IncludeLine);
-  } else if (makeAbsolutePath(Spec.OldCC) == AbsoluteCurrentFile) {
+  } else if (makeAbsolutePath(Context->Spec.OldCC) == AbsoluteCurrentFile) {
     CCIncludes.push_back(IncludeLine);
   }
 }
 
 void ClangMoveTool::removeClassDefinitionInOldFiles() {
   if (RemovedDecls.empty()) return;
   for (const auto &MovedDecl : RemovedDecls) {
     const auto &SM = *MovedDecl.SM;
     auto Range = GetFullRange(&SM, MovedDecl.Decl);
     clang::tooling::Replacement RemoveReplacement(
         SM,
         clang::CharSourceRange::getCharRange(Range.getBegin(), Range.getEnd()),
         "");
     std::string FilePath = RemoveReplacement.getFilePath().str();
-    auto Err = FileToReplacements[FilePath].add(RemoveReplacement);
+    auto Err = Context->FileToReplacements[FilePath].add(RemoveReplacement);
     if (Err)
       llvm::errs() << llvm::toString(std::move(Err)) << "\n";
   }
   const SourceManager* SM = RemovedDecls[0].SM;
 
   // Post process of cleanup around all the replacements.
-  for (auto& FileAndReplacements: FileToReplacements) {
+  for (auto& FileAndReplacements: Context->FileToReplacements) {
     StringRef FilePath = FileAndReplacements.first;
     // Add #include of new header to old header.
-    if (Spec.OldDependOnNew &&
-        MakeAbsolutePath(*SM, FilePath) == makeAbsolutePath(Spec.OldHeader)) {
+    if (Context->Spec.OldDependOnNew &&
+        MakeAbsolutePath(*SM, FilePath) ==
+            makeAbsolutePath(Context->Spec.OldHeader)) {
       // FIXME: Minimize the include path like include-fixer.
-      std::string IncludeNewH = "#include \""  + Spec.NewHeader + "\"\n";
+      std::string IncludeNewH =
+          "#include \"" + Context->Spec.NewHeader + "\"\n";
       // This replacment for inserting header will be cleaned up at the end.
       auto Err = FileAndReplacements.second.add(
           tooling::Replacement(FilePath, UINT_MAX, 0, IncludeNewH));
       if (Err)
         llvm::errs() << llvm::toString(std::move(Err)) << "\n";
     }
 
     auto SI = FilePathToFileID.find(FilePath);
     // Ignore replacements for new.h/cc.
     if (SI == FilePathToFileID.end()) continue;
     llvm::StringRef Code = SM->getBufferData(SI->second);
     format::FormatStyle Style =
-        format::getStyle("file", FilePath, FallbackStyle);
+        format::getStyle("file", FilePath, Context->FallbackStyle);
     auto CleanReplacements = format::cleanupAroundReplacements(
-        Code, FileToReplacements[FilePath], Style);
+        Code, Context->FileToReplacements[FilePath], Style);
 
     if (!CleanReplacements) {
       llvm::errs() << llvm::toString(CleanReplacements.takeError()) << "\n";
       continue;
     }
-    FileToReplacements[FilePath] = *CleanReplacements;
+    Context->FileToReplacements[FilePath] = *CleanReplacements;
   }
 }
 
 void ClangMoveTool::moveClassDefinitionToNewFiles() {
   std::vector<MovedDecl> NewHeaderDecls;
   std::vector<MovedDecl> NewCCDecls;
   for (const auto &MovedDecl : MovedDecls) {
-    if (isInHeaderFile(*MovedDecl.SM, MovedDecl.Decl, OriginalRunningDirectory,
-                       Spec.OldHeader))
+    if (isInHeaderFile(*MovedDecl.SM, MovedDecl.Decl,
+                       Context->OriginalRunningDirectory,
+                       Context->Spec.OldHeader))
       NewHeaderDecls.push_back(MovedDecl);
     else
       NewCCDecls.push_back(MovedDecl);
   }
 
-  if (!Spec.NewHeader.empty()) {
+  if (!Context->Spec.NewHeader.empty()) {
     std::string OldHeaderInclude =
-        Spec.NewDependOnOld ? "#include \"" + Spec.OldHeader + "\"\n" : "";
-    FileToReplacements[Spec.NewHeader] = createInsertedReplacements(
-        HeaderIncludes, NewHeaderDecls, Spec.NewHeader, /*IsHeader=*/true,
+        Context->Spec.NewDependOnOld
+            ? "#include \"" + Context->Spec.OldHeader + "\"\n"
+            : "";
+    Context->FileToReplacements[Context->Spec.NewHeader] =
+        createInsertedReplacements(HeaderIncludes, NewHeaderDecls,
+                                   Context->Spec.NewHeader, /*IsHeader=*/true,
                                    OldHeaderInclude);
   }
-  if (!Spec.NewCC.empty())
-    FileToReplacements[Spec.NewCC] =
-        createInsertedReplacements(CCIncludes, NewCCDecls, Spec.NewCC);
+  if (!Context->Spec.NewCC.empty())
+    Context->FileToReplacements[Context->Spec.NewCC] =
+        createInsertedReplacements(CCIncludes, NewCCDecls, Context->Spec.NewCC);
 }
 
 // Move all contents from OldFile to NewFile.
 void ClangMoveTool::moveAll(SourceManager &SM, StringRef OldFile,
                             StringRef NewFile) {
   const FileEntry *FE = SM.getFileManager().getFile(makeAbsolutePath(OldFile));
   if (!FE) {
     llvm::errs() << "Failed to get file: " << OldFile << "\n";
     return;
   }
   FileID ID = SM.getOrCreateFileID(FE, SrcMgr::C_User);
   auto Begin = SM.getLocForStartOfFile(ID);
   auto End = SM.getLocForEndOfFile(ID);
   clang::tooling::Replacement RemoveAll (
       SM, clang::CharSourceRange::getCharRange(Begin, End), "");
   std::string FilePath = RemoveAll.getFilePath().str();
-  FileToReplacements[FilePath] = clang::tooling::Replacements(RemoveAll);
+  Context->FileToReplacements[FilePath] =
+      clang::tooling::Replacements(RemoveAll);
 
   StringRef Code = SM.getBufferData(ID);
   if (!NewFile.empty()) {
     auto AllCode = clang::tooling::Replacements(
         clang::tooling::Replacement(NewFile, 0, 0, Code));
     // If we are moving from old.cc, an extra step is required: excluding
     // the #include of "old.h", instead, we replace it with #include of "new.h".
-    if (Spec.NewCC == NewFile && OldHeaderIncludeRange.isValid()) {
+    if (Context->Spec.NewCC == NewFile && OldHeaderIncludeRange.isValid()) {
       AllCode = AllCode.merge(
           clang::tooling::Replacements(clang::tooling::Replacement(
-              SM, OldHeaderIncludeRange, '"' + Spec.NewHeader + '"')));
+              SM, OldHeaderIncludeRange, '"' + Context->Spec.NewHeader + '"')));
     }
-    FileToReplacements[NewFile] = std::move(AllCode);
+    Context->FileToReplacements[NewFile] = std::move(AllCode);
   }
 }
 
 void ClangMoveTool::onEndOfTranslationUnit() {
+  if (Context->DumpDeclarations) {
+    assert(Reporter);
+    for (const auto * Decl : UnremovedDeclsInOldHeader) {
+      auto Kind = Decl->getKind();
+      const std::string QualifiedName = Decl->getQualifiedNameAsString();
+      if (Kind == Decl::Kind::Function || Kind == Decl::Kind::FunctionTemplate)
+        Reporter->reportDeclaration(QualifiedName, "Function");
+      else if (Kind == Decl::Kind::ClassTemplate ||
+               Kind == Decl::Kind::CXXRecord)
+        Reporter->reportDeclaration(QualifiedName, "Class");
+    }
+    return;
+  }
+
   if (RemovedDecls.empty())
     return;
-  if (UnremovedDeclsInOldHeader.empty() && !Spec.OldHeader.empty()) {
+  if (UnremovedDeclsInOldHeader.empty() && !Context->Spec.OldHeader.empty()) {
     auto &SM = *RemovedDecls[0].SM;
-    moveAll(SM, Spec.OldHeader, Spec.NewHeader);
-    moveAll(SM, Spec.OldCC, Spec.NewCC);
+    moveAll(SM, Context->Spec.OldHeader, Context->Spec.NewHeader);
+    moveAll(SM, Context->Spec.OldCC, Context->Spec.NewCC);
     return;
   }
   removeClassDefinitionInOldFiles();
   moveClassDefinitionToNewFiles();
 }
 
 } // namespace move
 } // namespace clang

clang-move/tool/ClangMoveMain.cpp

if (std::error_code ec =
           llvm::sys::fs::openFileForWrite(path, fd, llvm::sys::fs::F_Text))
     return ec;
 
   return llvm::sys::Process::SafelyCloseFileDescriptor(fd);
 }
 
 cl::OptionCategory ClangMoveCategory("clang-move options");
 
-cl::list<std::string> Names("names", cl::CommaSeparated, cl::OneOrMore,
+cl::list<std::string> Names("names", cl::CommaSeparated,
                             cl::desc("The list of the names of classes being "
                                      "moved, e.g. \"Foo,a::Foo,b::Foo\"."),
                             cl::cat(ClangMoveCategory));
 
 cl::opt<std::string>
     OldHeader("old_header",
               cl::desc("The relative/absolute file path of old header."),
               cl::cat(ClangMoveCategory));
cl::opt<std::string>
     Style("style",
           cl::desc("The style name used for reformatting. Default is \"llvm\""),
           cl::init("llvm"), cl::cat(ClangMoveCategory));
 
 cl::opt<bool> Dump("dump_result",
                    cl::desc("Dump results in JSON format to stdout."),
                    cl::cat(ClangMoveCategory));
 
+cl::opt<bool> DumpDecls(
+    "dump_decls",
+    cl::desc("Dump all declarations in old header (JSON format) to stdout. If "
+             "the option is specified, other command options will be ignored. "
+             "An empty JSON will be returned if old header isn't specified."),
+    cl::cat(ClangMoveCategory));
+
 } // namespace
 
 int main(int argc, const char **argv) {
   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
   // Add "-fparse-all-comments" compile option to make clang parse all comments,
   // otherwise, ordinary comments like "//" and "/*" won't get parsed (This is
   // a bit of hacky).
   std::vector<std::string> ExtraArgs(argv, argv + argc);
if (OldDependOnNew && NewDependOnOld) {
     llvm::errs() << "Provide either --old_depend_on_new or "
                     "--new_depend_on_old. clang-move doesn't support these two "
                     "options at same time (It will introduce include cycle).\n";
     return 1;
   }
 
   tooling::RefactoringTool Tool(OptionsParser.getCompilations(),
                                 OptionsParser.getSourcePathList());
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names = {Names.begin(), Names.end()};
   Spec.OldHeader = OldHeader;
   Spec.NewHeader = NewHeader;
   Spec.OldCC = OldCC;
   Spec.NewCC = NewCC;
   Spec.OldDependOnNew = OldDependOnNew;
   Spec.NewDependOnOld = NewDependOnOld;
 
   llvm::SmallString<128> InitialDirectory;
   if (std::error_code EC = llvm::sys::fs::current_path(InitialDirectory))
     llvm::report_fatal_error("Cannot detect current path: " +
                              Twine(EC.message()));
 
+  move::ClangMoveContext Context{Spec, Tool.getReplacements(),
+                                 InitialDirectory.str(), Style, DumpDecls};
+  move::DeclarationReporter Reporter;
   auto Factory = llvm::make_unique<clang::move::ClangMoveActionFactory>(
-      Spec, Tool.getReplacements(), InitialDirectory.str(), Style);
+      &Context, &Reporter);
 
   int CodeStatus = Tool.run(Factory.get());
   if (CodeStatus)
     return CodeStatus;
 
+  if (DumpDecls) {
+    llvm::outs() << "[\n";
+    const auto& Declarations = Reporter.getDeclarationList();
+    for (auto DeclPair: Declarations) {
+      llvm::outs() << "  {\n";
+      llvm::outs() << "    \"DeclarationName\": \"" << DeclPair.first
+                   << "\",\n";
+      llvm::outs() << "    \"DeclarationType\": \"" << DeclPair.second
+                   << "\"\n";
+      llvm::outs() << "  }";
+      // Don't print trailing "," at the end of last element.
+      if (DeclPair!= *(--Declarations.end()))
+        llvm::outs() << ",\n";
+    }
+    llvm::outs() << "\n]\n";
+    return 0;
+  }
+
   if (!NewCC.empty()) {
     std::error_code EC = CreateNewFile(NewCC);
     if (EC) {
       llvm::errs() << "Failed to create " << NewCC << ": " << EC.message()
                    << "\n";
       return EC.value();
     }
   }

unittests/clang-move/ClangMoveTests.cpp

const char ExpectedNewCC[] = "namespace a {\n"
                              "/////////////\n"
                              "// comment //\n"
                              "/////////////\n"
                              "int Foo::b = 2;\n"
                              "} // namespace b\n"
                              "} // namespace a\n";
 
 std::map<std::string, std::string>
-runClangMoveOnCode(const move::ClangMoveTool::MoveDefinitionSpec &Spec,
+runClangMoveOnCode(const move::MoveDefinitionSpec &Spec,
                    const char *const Header = TestHeader,
-                   const char *const CC = TestCC) {
+                   const char *const CC = TestCC,
+                   DeclarationReporter* const Reporter = nullptr) {
   clang::RewriterTestContext Context;
 
   std::map<llvm::StringRef, clang::FileID> FileToFileID;
   std::vector<std::pair<std::string, std::string>> FileToSourceText = {
       {TestHeaderName, Header}, {TestCCName, CC}};
 
   auto CreateFiles = [&FileToSourceText, &Context, &FileToFileID](
       llvm::StringRef Name, llvm::StringRef Code) {
     if (!Name.empty()) {
       FileToFileID[Name] = Context.createInMemoryFile(Name, Code);
     }
   };
   CreateFiles(Spec.NewCC, "");
   CreateFiles(Spec.NewHeader, "");
   CreateFiles(Spec.OldHeader, Header);
   CreateFiles(Spec.OldCC, CC);
 
   std::map<std::string, tooling::Replacements> FileToReplacements;
   llvm::SmallString<128> InitialDirectory;
   std::error_code EC = llvm::sys::fs::current_path(InitialDirectory);
   assert(!EC);
   (void)EC;
+  ClangMoveContext MoveContext = {Spec, FileToReplacements,
+                                  InitialDirectory.str(), "LLVM",
+                                  Reporter != nullptr};
+
   auto Factory = llvm::make_unique<clang::move::ClangMoveActionFactory>(
-      Spec, FileToReplacements, InitialDirectory.str(), "LLVM");
+      &MoveContext, Reporter);
 
   tooling::runToolOnCodeWithArgs(
       Factory->create(), CC, {"-std=c++11", "-fparse-all-comments"},
       TestCCName, "clang-move", std::make_shared<PCHContainerOperations>(),
       FileToSourceText);
   formatAndApplyAllReplacements(FileToReplacements, Context.Rewrite, "llvm");
   // The Key is file name, value is the new code after moving the class.
   std::map<std::string, std::string> Results;
   for (const auto &It : FileToReplacements) {
     StringRef FilePath = It.first;
     Results[FilePath] = Context.getRewrittenText(FileToFileID[FilePath]);
   }
   return Results;
 }
 
 TEST(ClangMove, MoveHeaderAndCC) {
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names = {std::string("a::b::Foo")};
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   std::string ExpectedHeader = "#include \"" + Spec.NewHeader + "\"\n\n";
   auto Results = runClangMoveOnCode(Spec);
   EXPECT_EQ(ExpectedTestHeader, Results[Spec.OldHeader]);
   EXPECT_EQ(ExpectedTestCC, Results[Spec.OldCC]);
   EXPECT_EQ(ExpectedNewHeader, Results[Spec.NewHeader]);
   EXPECT_EQ(ExpectedHeader + ExpectedNewCC, Results[Spec.NewCC]);
 }
 
 TEST(ClangMove, MoveHeaderOnly) {
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names = {std::string("a::b::Foo")};
   Spec.OldHeader = "foo.h";
   Spec.NewHeader = "new_foo.h";
   auto Results = runClangMoveOnCode(Spec);
   EXPECT_EQ(2u, Results.size());
   EXPECT_EQ(ExpectedTestHeader, Results[Spec.OldHeader]);
   EXPECT_EQ(ExpectedNewHeader, Results[Spec.NewHeader]);
 }
 
 TEST(ClangMove, MoveCCOnly) {
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names = {std::string("a::b::Foo")};
   Spec.OldCC = "foo.cc";
   Spec.NewCC = "new_foo.cc";
   std::string ExpectedHeader = "#include \"foo.h\"\n\n";
   auto Results = runClangMoveOnCode(Spec);
   EXPECT_EQ(2u, Results.size());
   EXPECT_EQ(ExpectedTestCC, Results[Spec.OldCC]);
   EXPECT_EQ(ExpectedHeader + ExpectedNewCC, Results[Spec.NewCC]);
 }
 
 TEST(ClangMove, MoveNonExistClass) {
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names = {std::string("NonExistFoo")};
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   auto Results = runClangMoveOnCode(Spec);
   EXPECT_EQ(0u, Results.size());
 }
 
 TEST(ClangMove, MoveAll) {
   std::vector<std::string> TestHeaders = {
     "class A {\npublic:\n  int f();\n};",
     // forward declaration.
     "class B;\nclass A {\npublic:\n  int f();\n};",
     // template forward declaration.
     "template <typename T> class B;\nclass A {\npublic:\n  int f();\n};",
     "namespace a {}\nclass A {\npublic:\n  int f();\n};",
     "namespace a {}\nusing namespace a;\nclass A {\npublic:\n  int f();\n};",
   };
   const char Code[] = "#include \"foo.h\"\nint A::f() { return 0; }";
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("A");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   for (const auto& Header : TestHeaders) {
     auto Results = runClangMoveOnCode(Spec, Header.c_str(), Code);
     EXPECT_EQ(Header, Results[Spec.NewHeader]);
     EXPECT_EQ("", Results[Spec.OldHeader]);
     EXPECT_EQ("", Results[Spec.OldCC]);
   }
 }
 
 TEST(ClangMove, MoveAllMultipleClasses) {
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   std::vector<std::string> TestHeaders = {
     "class C;\nclass A {\npublic:\n  int f();\n};\nclass B {};",
     "class C;\nclass B;\nclass A {\npublic:\n  int f();\n};\nclass B {};",
   };
   const char Code[] = "#include \"foo.h\"\nint A::f() { return 0; }";
   Spec.Names = {std::string("A"), std::string("B")};
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
TEST(ClangMove, DontMoveAll) {
   const char Code[] = "#include \"foo.h\"\nint A::f() { return 0; }";
   std::vector<std::string> TestHeaders = {
     "typedef int Int;\nclass A {\npublic:\n  int f();\n};\n",
     "using Int=int;\nclass A {\npublic:\n  int f();\n};\n",
     "class B {};\nclass A {\npublic:\n  int f();\n};\n",
     "void f() {};\nclass A {\npublic:\n  int f();\n};\n",
     "enum Color { RED };\nclass A {\npublic:\n  int f();\n};\n",
   };
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("A");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   for (const auto& Header : TestHeaders) {
     auto Results = runClangMoveOnCode(Spec, Header.c_str(), Code);
     EXPECT_EQ(ExpectedHeader, Results[Spec.NewHeader]);
     // The expected old header should not contain class A definition.
     std::string ExpectedOldHeader = Header.substr(0, Header.size() - 32);
     EXPECT_EQ(ExpectedOldHeader, Results[Spec.OldHeader]);
   }
 }
 
 TEST(ClangMove, MacroInFunction) {
   const char TestHeader[] = "#define INT int\n"
                             "class A {\npublic:\n  int f();\n};\n"
                             "class B {};\n";
   const char TestCode[] = "#include \"foo.h\"\n"
                           "INT A::f() { return 0; }\n";
   const char ExpectedNewCode[] = "#include \"new_foo.h\"\n\n"
                                  "INT A::f() { return 0; }\n";
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("A");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   auto Results = runClangMoveOnCode(Spec, TestHeader, TestCode);
   EXPECT_EQ(ExpectedNewCode, Results[Spec.NewCC]);
 }
TEST(ClangMove, WellFormattedCode) {
   const std::string TestCode = "#include \"foo.h\"\n" + CommonCode;
   const std::string ExpectedNewHeader = "#ifndef NEW_FOO_H\n"
                                         "#define NEW_FOO_H\n"
                                         "\n" +
                                         CommonHeader +
                                         "\n"
                                         "#endif // NEW_FOO_H\n";
   const std::string ExpectedNewCC = "#include \"new_foo.h\"\n" + CommonCode;
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("a::b::c::A");
   Spec.Names.push_back("a::d::e::B");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   auto Results = runClangMoveOnCode(Spec, TestHeader.c_str(), TestCode.c_str());
   EXPECT_EQ(ExpectedNewCC, Results[Spec.NewCC]);
   EXPECT_EQ(ExpectedNewHeader, Results[Spec.NewHeader]);
 }
 
 TEST(ClangMove, AddDependentNewHeader) {
   const char TestHeader[] = "class A {};\n"
                             "class B {};\n";
   const char TestCode[] = "#include \"foo.h\"\n";
   const char ExpectedOldHeader[] = "#include \"new_foo.h\"\nclass B {};\n";
   const char ExpectedNewHeader[] = "#ifndef NEW_FOO_H\n"
                                    "#define NEW_FOO_H\n"
                                    "\n"
                                    "class A {};\n"
                                    "\n"
                                    "#endif // NEW_FOO_H\n";
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("A");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   Spec.OldDependOnNew = true;
   auto Results = runClangMoveOnCode(Spec, TestHeader, TestCode);
   EXPECT_EQ(ExpectedOldHeader, Results[Spec.OldHeader]);
   EXPECT_EQ(ExpectedNewHeader, Results[Spec.NewHeader]);
 }
 
 TEST(ClangMove, AddDependentOldHeader) {
   const char TestHeader[] = "class A {};\n"
                             "class B {};\n";
   const char TestCode[] = "#include \"foo.h\"\n";
   const char ExpectedNewHeader[] = "#ifndef NEW_FOO_H\n"
                                    "#define NEW_FOO_H\n"
                                    "\n"
                                    "#include \"foo.h\"\n"
                                    "\n"
                                    "class B {};\n"
                                    "\n"
                                    "#endif // NEW_FOO_H\n";
   const char ExpectedOldHeader[] = "class A {};\n";
-  move::ClangMoveTool::MoveDefinitionSpec Spec;
+  move::MoveDefinitionSpec Spec;
   Spec.Names.push_back("B");
   Spec.OldHeader = "foo.h";
   Spec.OldCC = "foo.cc";
   Spec.NewHeader = "new_foo.h";
   Spec.NewCC = "new_foo.cc";
   Spec.NewDependOnOld = true;
   auto Results = runClangMoveOnCode(Spec, TestHeader, TestCode);
   EXPECT_EQ(ExpectedNewHeader, Results[Spec.NewHeader]);
   EXPECT_EQ(ExpectedOldHeader, Results[Spec.OldHeader]);
 }
 
+TEST(ClangMove, DumpDecls) {
+  const char TestHeader[] = "template <typename T>\n"
+                            "class A {\n"
+                            " public:\n"
+                            "  void f();\n"
+                            "  template <typename U> void h();\n"
+                            "  static int b;\n"
+                            "};\n"
+                            "\n"
+                            "template <typename T> void A<T>::f() {}\n"
+                            "\n"
+                            "template <typename T>\n"
+                            "template <typename U>\n"
+                            "void A<T>::h() {}\n"
+                            "\n"
+                            "template <typename T> int A<T>::b = 2;\n"
+                            "\n"
+                            "template <> class A<int> {};\n"
+                            "\n"
+                            "class B {};\n"
+                            "\n"
+                            "namespace a {\n"
+                            "class Move1 {};\n"
+                            "void f1() {}\n"
+                            "void f2();\n"
+                            "} // namespace a\n"
+                            "\n"
+                            "namespace a {\n"
+                            "namespace b {\n"
+                            "class Move1 { public : void f(); };\n"
+                            "void f() {}\n"
+                            "} // namespace b\n"
+                            "} // namespace a\n";
+  const char TestCode[] = "#include \"foo.h\"\n";
+  move::MoveDefinitionSpec Spec;
+  Spec.Names.push_back("B");
+  Spec.OldHeader = "foo.h";
+  Spec.OldCC = "foo.cc";
+  Spec.NewHeader = "new_foo.h";
+  Spec.NewCC = "new_foo.cc";
+  DeclarationReporter Reporter;
+  std::vector<DeclarationReporter::DeclarationPair> ExpectedDeclarations = {
+      {"A", "Class"},
+      {"B", "Class"},
+      {"a::Move1", "Class"},
+      {"a::f1", "Function"},
+      {"a::f2", "Function"},
+      {"a::b::Move1", "Class"},
+      {"a::b::f",  "Function"}
+  };
+  runClangMoveOnCode(Spec, TestHeader, TestCode, &Reporter);
+  auto ExpectedDeclaration = ExpectedDeclarations.begin();
+  for (auto DeclPair: Reporter.getDeclarationList()) {
+    ASSERT_TRUE(ExpectedDeclaration != ExpectedDeclarations.end());
+    EXPECT_EQ(DeclPair, *ExpectedDeclaration);
+    ++ExpectedDeclaration;
+  }
+}
+
 } // namespace
 } // namespce move
 } // namespace clang