ObjC method rename support

We now support renaming ObjC methods even with multiple selector pieces.

This requires clangd to lex each file to discover the selector pieces
since the index only stores the location of the initial selector token.

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

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

@@ -176,18 +176,19 @@ bool isSpelled(SourceLocation Loc, const NamedDecl &ND) {
   if (NameKind != DeclarationName::Identifier &&
       NameKind != DeclarationName::CXXConstructorName &&
       NameKind != DeclarationName::ObjCZeroArgSelector &&
-      NameKind != DeclarationName::ObjCOneArgSelector)
+      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();
+  auto TokSpelling = clang::Lexer::getSpelling(Tok, SM, LO);
   if (const auto *MD = dyn_cast<ObjCMethodDecl>(&ND))
-    StrName = MD->getSelector().getNameForSlot(0).str();
-  return clang::Lexer::getSpelling(Tok, SM, LO) == StrName;
+    return TokSpelling == MD->getSelector().getNameForSlot(0);
+  return TokSpelling == Name.getAsString();
 }
 } // namespace