Add support for renaming objc methods, even those with multiple selector pieces (llvm#76466)

This adds support for  renaming Objective-C methods, which are unique since their method names can be split across multiple tokens.

Author: DavidGoldman

clang-tools-extra/clangd/ClangdLSPServer.cpp

@@ -844,14 +844,17 @@ void ClangdLSPServer::onWorkspaceSymbol(
 }
 
 void ClangdLSPServer::onPrepareRename(const TextDocumentPositionParams &Params,
-                                      Callback<std::optional<Range>> Reply) {
+                                      Callback<PrepareRenameResult> Reply) {
   Server->prepareRename(
       Params.textDocument.uri.file(), Params.position, /*NewName*/ std::nullopt,
       Opts.Rename,
       [Reply = std::move(Reply)](llvm::Expected<RenameResult> Result) mutable {
         if (!Result)
           return Reply(Result.takeError());
-        return Reply(std::move(Result->Target));
+        PrepareRenameResult PrepareResult;
+        PrepareResult.range = Result->Target;
+        PrepareResult.placeholder = Result->Placeholder;
+        return Reply(std::move(PrepareResult));
       });
 }
 

clang-tools-extra/clangd/ClangdLSPServer.h

@@ -134,7 +134,7 @@ class ClangdLSPServer : private ClangdServer::Callbacks,
   void onWorkspaceSymbol(const WorkspaceSymbolParams &,
                          Callback<std::vector<SymbolInformation>>);
   void onPrepareRename(const TextDocumentPositionParams &,
-                       Callback<std::optional<Range>>);
+                       Callback<PrepareRenameResult>);
   void onRename(const RenameParams &, Callback<WorkspaceEdit>);
   void onHover(const TextDocumentPositionParams &,
                Callback<std::optional<Hover>>);

clang-tools-extra/clangd/Protocol.cpp

@@ -1187,6 +1187,15 @@ bool fromJSON(const llvm::json::Value &Params, RenameParams &R,
          O.map("position", R.position) && O.map("newName", R.newName);
 }
 
+llvm::json::Value toJSON(const PrepareRenameResult &PRR) {
+  if (PRR.placeholder.empty())
+    return toJSON(PRR.range);
+  return llvm::json::Object{
+      {"range", toJSON(PRR.range)},
+      {"placeholder", PRR.placeholder},
+  };
+}
+
 llvm::json::Value toJSON(const DocumentHighlight &DH) {
   return llvm::json::Object{
       {"range", toJSON(DH.range)},

clang-tools-extra/clangd/Protocol.h

@@ -1436,6 +1436,14 @@ struct RenameParams {
 };
 bool fromJSON(const llvm::json::Value &, RenameParams &, llvm::json::Path);
 
+struct PrepareRenameResult {
+  /// Range of the string to rename.
+  Range range;
+  /// Placeholder text to use in the editor if non-empty.
+  std::string placeholder;
+};
+llvm::json::Value toJSON(const PrepareRenameResult &PRR);
+
 enum class DocumentHighlightKind { Text = 1, Read = 2, Write = 3 };
 
 /// A document highlight is a range inside a text document which deserves
@@ -1969,6 +1977,28 @@ llvm::raw_ostream &operator<<(llvm::raw_ostream &, const ASTNode &);
 } // namespace clang
 
 namespace llvm {
+
+template <> struct DenseMapInfo<clang::clangd::Range> {
+  using Range = clang::clangd::Range;
+  static inline Range getEmptyKey() {
+    static clang::clangd::Position Tomb{-1, -1};
+    static Range R{Tomb, Tomb};
+    return R;
+  }
+  static inline Range getTombstoneKey() {
+    static clang::clangd::Position Tomb{-2, -2};
+    static Range R{Tomb, Tomb};
+    return R;
+  }
+  static unsigned getHashValue(const Range &Val) {
+    return llvm::hash_combine(Val.start.line, Val.start.character, Val.end.line,
+                              Val.end.character);
+  }
+  static bool isEqual(const Range &LHS, const Range &RHS) {
+    return std::tie(LHS.start, LHS.end) == std::tie(RHS.start, RHS.end);
+  }
+};
+
 template <> struct format_provider<clang::clangd::Position> {
   static void format(const clang::clangd::Position &Pos, raw_ostream &OS,
                      StringRef Style) {

clang-tools-extra/clangd/index/SymbolCollector.cpp

@@ -174,16 +174,21 @@ bool isSpelled(SourceLocation Loc, const NamedDecl &ND) {
   auto Name = ND.getDeclName();
   const auto NameKind = Name.getNameKind();
   if (NameKind != DeclarationName::Identifier &&
-      NameKind != DeclarationName::CXXConstructorName)
+      NameKind != DeclarationName::CXXConstructorName &&
+      NameKind != DeclarationName::ObjCZeroArgSelector &&
+      NameKind != DeclarationName::ObjCOneArgSelector &&
+      NameKind != DeclarationName::ObjCMultiArgSelector)
     return false;
   const auto &AST = ND.getASTContext();
   const auto &SM = AST.getSourceManager();
   const auto &LO = AST.getLangOpts();
   clang::Token Tok;
   if (clang::Lexer::getRawToken(Loc, Tok, SM, LO))
     return false;
-  auto StrName = Name.getAsString();
-  return clang::Lexer::getSpelling(Tok, SM, LO) == StrName;
+  auto TokSpelling = clang::Lexer::getSpelling(Tok, SM, LO);
+  if (const auto *MD = dyn_cast<ObjCMethodDecl>(&ND))
+    return TokSpelling == MD->getSelector().getNameForSlot(0);
+  return TokSpelling == Name.getAsString();
 }
 } // namespace