[mlir-lsp] Add client information to the InitializationParams

[rriddle]

Summary

This is specified in the spec, but we just never really needed it. This
allows for users of the LSP libraries to inspect information about the
client that is connected to the server.

[jpienaar]

Could we have an error case perhaps?

mlir/lib/Tools/lsp-server-support/Protocol.cpp

306

How is this materialized below? E.g., name is just a std::string, so that seems that it would report an error if not set.

[rriddle]

In D155566#4511138, @jpienaar wrote:

Could we have an error case perhaps?

Yep, I'll add one. Thanks!

mlir/lib/Tools/lsp-server-support/Protocol.cpp

306

Oh, nice callout. Let me just make these fail.

mlir/include/mlir/Tools/lsp-server-support/Protocol.h

struct ClientCapabilities {
   bool codeActionStructure = false;
 };
 
 /// Add support for JSON serialization.
 bool fromJSON(const llvm::json::Value &value, ClientCapabilities &result,
               llvm::json::Path path);
 
 //===----------------------------------------------------------------------===//
+// ClientInfo
+//===----------------------------------------------------------------------===//
+
+struct ClientInfo {
+  /// The name of the client as defined by the client.
+  std::string name;
+
+  /// The client's version as defined by the client.
+  std::optional<std::string> version;
+};
+
+/// Add support for JSON serialization.
+bool fromJSON(const llvm::json::Value &value, ClientInfo &result,
+              llvm::json::Path path);
+
+//===----------------------------------------------------------------------===//
 // InitializeParams
 //===----------------------------------------------------------------------===//
 
 enum class TraceLevel {
   Off = 0,
   Messages = 1,
   Verbose = 2,
 };
 
 /// Add support for JSON serialization.
 bool fromJSON(const llvm::json::Value &value, TraceLevel &result,
               llvm::json::Path path);
 
 struct InitializeParams {
   /// The capabilities provided by the client (editor or tool).
   ClientCapabilities capabilities;
 
+  /// Information about the client.
+  std::optional<ClientInfo> clientInfo;
+
   /// The initial trace setting. If omitted trace is disabled ('off').
   std::optional<TraceLevel> trace;
 };
 
 /// Add support for JSON serialization.
 bool fromJSON(const llvm::json::Value &value, InitializeParams &result,
               llvm::json::Path path);
 

mlir/lib/Tools/lsp-server-support/Protocol.cpp

if (auto *codeAction = textDocument->getObject("codeAction")) {
       if (codeAction->getObject("codeActionLiteralSupport"))
         result.codeActionStructure = true;
     }
   }
   return true;
 }
 
 //===----------------------------------------------------------------------===//
+// ClientInfo
+//===----------------------------------------------------------------------===//
+
+bool mlir::lsp::fromJSON(const llvm::json::Value &value, ClientInfo &result,
+                         llvm::json::Path path) {
+  llvm::json::ObjectMapper o(value, path);
+  if (!o || !o.map("name", result.name))
+    return false;
+
+  // Don't fail if we can't parse version.
+  o.map("version", result.version);
+  return true;
+}
+
+//===----------------------------------------------------------------------===//
 // InitializeParams
 //===----------------------------------------------------------------------===//
 
 bool mlir::lsp::fromJSON(const llvm::json::Value &value, TraceLevel &result,
                          llvm::json::Path path) {
   if (std::optional<StringRef> str = value.getAsString()) {
     if (*str == "off") {
       result = TraceLevel::Off;

 bool mlir::lsp::fromJSON(const llvm::json::Value &value,
                          InitializeParams &result, llvm::json::Path path) {
   llvm::json::ObjectMapper o(value, path);
   if (!o)
     return false;
   // We deliberately don't fail if we can't parse individual fields.
   o.map("capabilities", result.capabilities);
   o.map("trace", result.trace);
+  mapOptOrNull(value, "clientInfo", result.clientInfo, path);
+
   return true;
 }
 
 //===----------------------------------------------------------------------===//
 // TextDocumentItem
 //===----------------------------------------------------------------------===//
 
 bool mlir::lsp::fromJSON(const llvm::json::Value &value,

mlir/test/mlir-lsp-server/initialize-params-invalid.test

 // RUN: mlir-lsp-server -lit-test < %s | FileCheck -strict-whitespace %s
 // Test with invalid initialize request parameters
-{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":"","rootUri":"test:///workspace","capabilities":{},"trace":"verbose"}}
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":"","rootUri":"test:///workspace","capabilities":{},"clientInfo":{"name": 10},"trace":"verbose"}}
 //      CHECK:  "id": 0,
 // CHECK-NEXT:  "jsonrpc": "2.0",
 // CHECK-NEXT:  "result": {
 // CHECK-NEXT:    "capabilities": {
 // ...
 // -----
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
 // -----
 {"jsonrpc":"2.0","method":"exit"}

mlir/test/mlir-lsp-server/initialize-params.test

 // RUN: mlir-lsp-server -lit-test < %s | FileCheck -strict-whitespace %s
 // Test initialize request parameters with rootUri
-{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootUri":"test:///workspace","capabilities":{},"trace":"off"}}
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootUri":"test:///workspace","capabilities":{},"clientInfo":{"name": "test", "version": "1.2.3"},"trace":"off"}}
 //      CHECK:  "id": 0,
 // CHECK-NEXT:  "jsonrpc": "2.0",
 // CHECK-NEXT:  "result": {
 // CHECK-NEXT:    "capabilities": {
 // CHECK-NEXT:      "codeActionProvider": true,
 // CHECK-NEXT:      "completionProvider": {
 // CHECK-NEXT:        "allCommitCharacters": [
 // CHECK:             ],