Implement code actions using clang FixIts

- Also make server check client version and show an error message if they do not match.

README.md

@@ -26,6 +26,7 @@ be productive with cquery. Here's a list of implemented features:
   * global symbol search
   * hover
   * diagnostics
+  * code actions (clang FixIts)
 
 # Setup - build cquery, install extension, setup project
 

src/clang_utils.cc

@@ -2,6 +2,24 @@
 
 #include "libclangmm/Utility.h"
 
+namespace {
+
+lsRange GetLsRangeForFixIt(const CXSourceRange& range) {
+  CXSourceLocation start = clang_getRangeStart(range);
+  CXSourceLocation end = clang_getRangeEnd(range);
+
+  unsigned int start_line, start_column;
+  clang_getSpellingLocation(start, nullptr, &start_line, &start_column, nullptr);
+  unsigned int end_line, end_column;
+  clang_getSpellingLocation(end, nullptr, &end_line, &end_column, nullptr);
+
+  return lsRange(
+    lsPosition(start_line - 1, start_column - 1) /*start*/,
+    lsPosition(end_line - 1, end_column) /*end*/);
+}
+
+}  // namespace
+
 optional<lsDiagnostic> BuildDiagnostic(CXDiagnostic diagnostic) {
   // Skip diagnostics in system headers.
   CXSourceLocation diag_loc = clang_getDiagnosticLocation(diagnostic);
@@ -45,7 +63,19 @@ optional<lsDiagnostic> BuildDiagnostic(CXDiagnostic diagnostic) {
     break;
   }
 
-  // TODO: integrate FixIts (ie, textDocument/codeAction)
+  // Report fixits
+  unsigned num_fixits = clang_getDiagnosticNumFixIts(diagnostic);
+  if (num_fixits > 0)
+    std::cerr << "!!!! Got " << num_fixits << " fixits" << std::endl;
+  for (unsigned i = 0; i < num_fixits; ++i) {
+    CXSourceRange replacement_range;
+    CXString text = clang_getDiagnosticFixIt(diagnostic, i, &replacement_range);
+
+    lsTextEdit edit;
+    edit.newText = clang::ToString(text);
+    edit.range = GetLsRangeForFixIt(replacement_range);
+    ls_diagnostic.fixits_.push_back(edit);
+  }
 
   clang_disposeDiagnostic(diagnostic);
 

src/command_line.cc

@@ -31,11 +31,15 @@
 // ie, a fully linear view of a function with inline function calls expanded.
 // We can probably use vscode decorators to achieve it.
 
+// TODO: implement ThreadPool type which monitors CPU usage / number of work items
+// per second completed and scales up/down number of running threads.
+
 namespace {
 
 std::vector<std::string> kEmptyArgs;
 
-
+// Expected client version. We show an error if this doesn't match.
+const int kExpectedClientVersion = 1;
 
 
 
@@ -898,6 +902,7 @@ void RegisterMessageTypes() {
   MessageRegistry::instance()->Register<Ipc_TextDocumentHover>();
   MessageRegistry::instance()->Register<Ipc_TextDocumentReferences>();
   MessageRegistry::instance()->Register<Ipc_TextDocumentDocumentSymbol>();
+  MessageRegistry::instance()->Register<Ipc_TextDocumentCodeAction>();
   MessageRegistry::instance()->Register<Ipc_TextDocumentCodeLens>();
   MessageRegistry::instance()->Register<Ipc_CodeLensResolve>();
   MessageRegistry::instance()->Register<Ipc_WorkspaceSymbol>();
@@ -1103,6 +1108,11 @@ void ParseFile(IndexerConfig* config,
       diag.params.uri = lsDocumentUri::FromPath(new_index->path);
       diag.params.diagnostics = new_index->diagnostics;
       IpcManager::instance()->SendOutMessageToClient(IpcId::TextDocumentPublishDiagnostics, diag);
+
+      // Cache diagnostics so we can show fixits.
+      WorkingFile* working_file = working_files->GetFileByFilename(new_index->path);
+      if (working_file)
+        working_file->diagnostics = new_index->diagnostics;
     }
 
 
@@ -1418,6 +1428,19 @@ bool QueryDbMainLoop(
 
           *config = *request->params.initializationOptions;
 
+          // Check client version.
+          if (config->clientVersion != kExpectedClientVersion) {
+            Out_ShowLogMessage out;
+            out.display_type = Out_ShowLogMessage::DisplayType::Show;
+            out.params.type = lsMessageType::Error;
+            out.params.message = "cquery client (v" + std::to_string(config->clientVersion) + ") and server (v" + std::to_string(kExpectedClientVersion) + ") version mismatch. Please update ";
+            if (config->clientVersion > kExpectedClientVersion)
+              out.params.message += "the cquery binary.";
+            else
+              out.params.message += "your extension client (VSIX file).";
+            out.Write(std::cout);
+          }
+
           // Make sure cache directory is valid.
           if (config->cacheDirectory.empty()) {
             std::cerr << "No cache directory" << std::endl;
@@ -1486,6 +1509,8 @@ bool QueryDbMainLoop(
         response.result.capabilities.hoverProvider = true;
         response.result.capabilities.referencesProvider = true;
 
+        response.result.capabilities.codeActionProvider = true;
+
         response.result.capabilities.documentSymbolProvider = true;
         response.result.capabilities.workspaceSymbolProvider = true;
 
@@ -1716,7 +1741,7 @@ bool QueryDbMainLoop(
         if (file)
           params.position = file->FindStableCompletionSource(params.position);
 
-        CompletionManager::OnComplete callback = std::bind([code_complete_cache](BaseIpcMessage* message, NonElidedVector<lsCompletionItem> results, NonElidedVector<lsDiagnostic> diagnostics) {
+        CompletionManager::OnComplete callback = std::bind([working_files, code_complete_cache](BaseIpcMessage* message, NonElidedVector<lsCompletionItem> results, NonElidedVector<lsDiagnostic> diagnostics) {
           auto msg = static_cast<Ipc_TextDocumentComplete*>(message);
           auto ipc = IpcManager::instance();
 
@@ -1725,13 +1750,21 @@ bool QueryDbMainLoop(
           complete_response.result.isIncomplete = false;
           complete_response.result.items = results;
 
+          // Emit completion results.
           ipc->SendOutMessageToClient(IpcId::TextDocumentCompletion, complete_response);
 
+          // Emit diagnostics.
           Out_TextDocumentPublishDiagnostics diagnostic_response;
           diagnostic_response.params.uri = msg->params.textDocument.uri;
           diagnostic_response.params.diagnostics = diagnostics;
           ipc->SendOutMessageToClient(IpcId::TextDocumentPublishDiagnostics, diagnostic_response);
 
+          // Cache diagnostics so we can show fixits.
+          WorkingFile* working_file = working_files->GetFileByFilename(msg->params.textDocument.uri.GetPath());
+          if (working_file)
+            working_file->diagnostics = diagnostics;
+
+          // Cache completion results so if the user types backspace we can respond faster.
           code_complete_cache->cached_path = msg->params.textDocument.uri.GetPath();
           code_complete_cache->cached_completion_position = msg->params.position;
           code_complete_cache->cached_results = results;
@@ -2021,6 +2054,50 @@ bool QueryDbMainLoop(
         break;
       }
 
+      case IpcId::TextDocumentCodeAction: {
+        // NOTE: This code snippet will generate some FixIts for testing:
+        //
+        //    struct origin { int x, int y };
+        //    void foo() {
+        //      point origin = {
+        //        x: 0.0,
+        //        y: 0.0
+        //      };
+        //    }
+        //
+        auto msg = static_cast<Ipc_TextDocumentCodeAction*>(message.get());
+
+        WorkingFile* working_file = working_files->GetFileByFilename(msg->params.textDocument.uri.GetPath());
+        if (!working_file) {
+          // TODO: send error response.
+          std::cerr << "[error] textDocument/codeAction could not find working file" << std::endl;
+          break;
+        }
+
+        int target_line = msg->params.range.start.line;
+
+        Out_TextDocumentCodeAction response;
+        response.id = msg->id;
+
+        for (lsDiagnostic& diag : working_file->diagnostics) {
+          // clang does not provide accurate ennough column reporting for
+          // diagnostics to do good column filtering, so report all
+          // diagnostics on the line.
+          if (!diag.fixits_.empty() && diag.range.start.line == target_line) {
+            Out_TextDocumentCodeAction::Command command;
+            command.title = "FixIt: " + diag.message;
+            command.command = "cquery._applyFixIt";
+            command.arguments.textDocumentUri = msg->params.textDocument.uri;
+            command.arguments.edits = diag.fixits_;
+            response.result.push_back(command);
+          }
+        }
+
+        response.Write(std::cerr);
+        ipc->SendOutMessageToClient(IpcId::TextDocumentCodeAction, response);
+        break;
+      }
+
       case IpcId::TextDocumentCodeLens: {
         auto msg = static_cast<Ipc_TextDocumentCodeLens*>(message.get());
 
@@ -2374,6 +2451,7 @@ void LanguageServerStdinLoop(IndexerConfig* config, std::unordered_map<IpcId, Ti
     case IpcId::TextDocumentHover:
     case IpcId::TextDocumentReferences:
     case IpcId::TextDocumentDocumentSymbol:
+    case IpcId::TextDocumentCodeAction:
     case IpcId::TextDocumentCodeLens:
     case IpcId::WorkspaceSymbol:
     case IpcId::CqueryFreshenIndex:

src/ipc.cc

@@ -38,6 +38,8 @@ const char* IpcIdToString(IpcId id) {
     return "textDocument/references";
   case IpcId::TextDocumentDocumentSymbol:
     return "textDocument/documentSymbol";
+  case IpcId::TextDocumentCodeAction:
+    return "textDocument/codeAction";
   case IpcId::TextDocumentCodeLens:
     return "textDocument/codeLens";
   case IpcId::CodeLensResolve:

src/ipc.h

@@ -24,6 +24,7 @@ enum class IpcId : int {
   TextDocumentHover,
   TextDocumentReferences,
   TextDocumentDocumentSymbol,
+  TextDocumentCodeAction,
   TextDocumentCodeLens,
   CodeLensResolve,
   WorkspaceSymbol,

src/language_server_api.h

@@ -73,6 +73,9 @@ struct IndexerConfig {
   bool enableCacheWrite = true;
   // If false, the index will not be loaded from a previous run.
   bool enableCacheRead = true;
+
+  // Version of the client.
+  int clientVersion = 0;
 };
 MAKE_REFLECT_STRUCT(IndexerConfig,
   cacheDirectory,
@@ -81,8 +84,9 @@ MAKE_REFLECT_STRUCT(IndexerConfig,
 
   maxWorkspaceSearchResults,
   indexerCount,
-  enableIndexing, enableCacheWrite, enableCacheRead);
+  enableIndexing, enableCacheWrite, enableCacheRead,
 
+  clientVersion);
 
 
 
@@ -330,6 +334,8 @@ struct lsCommand {
   // Actual command identifier.
   std::string command;
   // Arguments to run the command with.
+  // **NOTE** This must be serialized as an array. Use
+  // MAKE_REFLECT_STRUCT_WRITER_AS_ARRAY.
   T arguments;
 };
 template<typename TVisitor, typename T>
@@ -591,6 +597,9 @@ struct lsDiagnostic {
 
   // The diagnostic's message.
   std::string message;
+
+  // Non-serialized set of fixits.
+  NonElidedVector<lsTextEdit> fixits_;
 };
 MAKE_REFLECT_STRUCT(lsDiagnostic, range, severity, source, message);
 
@@ -1325,17 +1334,17 @@ struct lsSignatureHelp {
 
   // The active signature. If omitted or the value lies outside the
   // range of `signatures` the value defaults to zero or is ignored if
-  // `signatures.length === 0`. Whenever possible implementors should 
+  // `signatures.length === 0`. Whenever possible implementors should
-  // make an active decision about the active signature and shouldn't 
+  // make an active decision about the active signature and shouldn't
   // rely on a default value.
   // In future version of the protocol this property might become
   // mandantory to better express this.
   optional<int> activeSignature;
 
   // The active parameter of the active signature. If omitted or the value
-  // lies outside the range of `signatures[activeSignature].parameters` 
+  // lies outside the range of `signatures[activeSignature].parameters`
-  // defaults to 0 if the active signature has parameters. If 
+  // defaults to 0 if the active signature has parameters. If
-  // the active signature has no parameters it is ignored. 
+  // the active signature has no parameters it is ignored.
   // In future version of the protocol this property might become
   // mandantory to better express the active parameter if the
   // active signature does have any.
@@ -1422,6 +1431,44 @@ struct Out_TextDocumentReferences : public lsOutMessage<Out_TextDocumentReferenc
 };
 MAKE_REFLECT_STRUCT(Out_TextDocumentReferences, jsonrpc, id, result);
 
+// Code action
+struct Ipc_TextDocumentCodeAction : public IpcMessage<Ipc_TextDocumentCodeAction> {
+  const static IpcId kIpcId = IpcId::TextDocumentCodeAction;
+  // Contains additional diagnostic information about the context in which
+  // a code action is run.
+  struct lsCodeActionContext {
+	  // An array of diagnostics.
+	  NonElidedVector<lsDiagnostic> diagnostics;
+  };
+  // Params for the CodeActionRequest
+  struct lsCodeActionParams {
+	  // The document in which the command was invoked.
+	  lsTextDocumentIdentifier textDocument;
+	  // The range for which the command was invoked.
+    lsRange range;
+	  // Context carrying additional information.
+    lsCodeActionContext context;
+  };
+
+  lsRequestId id;
+  lsCodeActionParams params;
+};
+MAKE_REFLECT_STRUCT(Ipc_TextDocumentCodeAction::lsCodeActionContext, diagnostics);
+MAKE_REFLECT_STRUCT(Ipc_TextDocumentCodeAction::lsCodeActionParams, textDocument, range, context);
+MAKE_REFLECT_STRUCT(Ipc_TextDocumentCodeAction, id, params);
+struct Out_TextDocumentCodeAction : public lsOutMessage<Out_TextDocumentCodeAction> {
+  struct CommandArgs {
+    lsDocumentUri textDocumentUri;
+    NonElidedVector<lsTextEdit> edits;
+  };
+  using Command = lsCommand<CommandArgs>;
+
+  lsRequestId id;
+  NonElidedVector<Command> result;
+};
+MAKE_REFLECT_STRUCT_WRITER_AS_ARRAY(Out_TextDocumentCodeAction::CommandArgs, textDocumentUri, edits);
+MAKE_REFLECT_STRUCT(Out_TextDocumentCodeAction, jsonrpc, id, result);
+
 // List symbols in a document.
 struct lsDocumentSymbolParams {
   lsTextDocumentIdentifier textDocument;

src/serializer.h

@@ -56,7 +56,17 @@ struct IndexFile;
     REFLECT_MEMBER_END(); \
   }
 
+#define _MAPPABLE_REFLECT_ARRAY(name) \
+  Reflect(visitor, value.name);
 
+// Reflects the struct so it is serialized as an array instead of an object.
+// This currently only supports writers.
+#define MAKE_REFLECT_STRUCT_WRITER_AS_ARRAY(type, ...) \
+  inline void Reflect(Writer& visitor, type& value) { \
+    visitor.StartArray(); \
+    MACRO_MAP(_MAPPABLE_REFLECT_ARRAY, __VA_ARGS__) \
+    visitor.EndArray(); \
+  }
 
 
 

src/working_files.h

@@ -27,6 +27,8 @@ struct WorkingFile {
   // This map goes from buffer-line -> indices+1 in all_buffer_lines.
   // Note: The items in the value entry are 1-based liness.
   std::unordered_map<std::string, std::vector<int>> all_buffer_lines_lookup;
+  // A set of diagnostics that have been reported for this file.
+  std::vector<lsDiagnostic> diagnostics;
 
   WorkingFile(const std::string& filename, const std::string& buffer_content);