clang-tools-extra/clangd/Protocol.cpp

   1 //===--- Protocol.cpp - Language Server Protocol Implementation -----------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains the serialization code for the LSP structs.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "Protocol.h"
  14 #include "URI.h"
  15 #include "support/Logger.h"
  16 #include "clang/Basic/LLVM.h"
  17 #include "clang/Index/IndexSymbol.h"
  18 #include "llvm/ADT/StringExtras.h"
  19 #include "llvm/ADT/StringRef.h"
  20 #include "llvm/ADT/StringSwitch.h"
  21 #include "llvm/Support/ErrorHandling.h"
  22 #include "llvm/Support/JSON.h"
  23 #include "llvm/Support/Path.h"
  24 #include "llvm/Support/raw_ostream.h"
  25
  26 namespace clang {
  27 namespace clangd {
  28 namespace {
  29
  30 // Helper that doesn't treat `null` and absent fields as failures.
  31 template <typename T>
  32 bool mapOptOrNull(const llvm::json::Value &Params, llvm::StringLiteral Prop,
  33                   T &Out, llvm::json::Path P) {
  34   auto *O = Params.getAsObject();
  35   assert(O);
  36   auto *V = O->get(Prop);
  37   // Field is missing or null.
  38   if (!V || V->getAsNull())
  39     return true;
  40   return fromJSON(*V, Out, P.field(Prop));
  41 }
  42 } // namespace
  43
  44 char LSPError::ID;
  45
  46 URIForFile URIForFile::canonicalize(llvm::StringRef AbsPath,
  47                                     llvm::StringRef TUPath) {
  48   assert(llvm::sys::path::is_absolute(AbsPath) && "the path is relative");
  49   auto Resolved = URI::resolvePath(AbsPath, TUPath);
  50   if (!Resolved) {
  51     elog("URIForFile: failed to resolve path {0} with TU path {1}: "
  52          "{2}.\nUsing unresolved path.",
  53          AbsPath, TUPath, Resolved.takeError());
  54     return URIForFile(std::string(AbsPath));
  55   }
  56   return URIForFile(std::move(*Resolved));
  57 }
  58
  59 llvm::Expected<URIForFile> URIForFile::fromURI(const URI &U,
  60                                                llvm::StringRef HintPath) {
  61   auto Resolved = URI::resolve(U, HintPath);
  62   if (!Resolved)
  63     return Resolved.takeError();
  64   return URIForFile(std::move(*Resolved));
  65 }
  66
  67 bool fromJSON(const llvm::json::Value &E, URIForFile &R, llvm::json::Path P) {
  68   if (auto S = E.getAsString()) {
  69     auto Parsed = URI::parse(*S);
  70     if (!Parsed) {
  71       consumeError(Parsed.takeError());
  72       P.report("failed to parse URI");
  73       return false;
  74     }
  75     if (Parsed->scheme() != "file" && Parsed->scheme() != "test") {
  76       P.report("clangd only supports 'file' URI scheme for workspace files");
  77       return false;
  78     }
  79     // "file" and "test" schemes do not require hint path.
  80     auto U = URIForFile::fromURI(*Parsed, /*HintPath=*/"");
  81     if (!U) {
  82       P.report("unresolvable URI");
  83       consumeError(U.takeError());
  84       return false;
  85     }
  86     R = std::move(*U);
  87     return true;
  88   }
  89   return false;
  90 }
  91
  92 llvm::json::Value toJSON(const URIForFile &U) { return U.uri(); }
  93
  94 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const URIForFile &U) {
  95   return OS << U.uri();
  96 }
  97
  98 llvm::json::Value toJSON(const TextDocumentIdentifier &R) {
  99   return llvm::json::Object{{"uri", R.uri}};
 100 }
 101
 102 bool fromJSON(const llvm::json::Value &Params, TextDocumentIdentifier &R,
 103               llvm::json::Path P) {
 104   llvm::json::ObjectMapper O(Params, P);
 105   return O && O.map("uri", R.uri);
 106 }
 107
 108 llvm::json::Value toJSON(const VersionedTextDocumentIdentifier &R) {
 109   auto Result = toJSON(static_cast<const TextDocumentIdentifier &>(R));
 110   Result.getAsObject()->try_emplace("version", R.version);
 111   return Result;
 112 }
 113
 114 bool fromJSON(const llvm::json::Value &Params,
 115               VersionedTextDocumentIdentifier &R, llvm::json::Path P) {
 116   llvm::json::ObjectMapper O(Params, P);
 117   return fromJSON(Params, static_cast<TextDocumentIdentifier &>(R), P) && O &&
 118          O.map("version", R.version);
 119 }
 120
 121 bool fromJSON(const llvm::json::Value &Params, Position &R,
 122               llvm::json::Path P) {
 123   llvm::json::ObjectMapper O(Params, P);
 124   return O && O.map("line", R.line) && O.map("character", R.character);
 125 }
 126
 127 llvm::json::Value toJSON(const Position &P) {
 128   return llvm::json::Object{
 129       {"line", P.line},
 130       {"character", P.character},
 131   };
 132 }
 133
 134 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Position &P) {
 135   return OS << P.line << ':' << P.character;
 136 }
 137
 138 bool fromJSON(const llvm::json::Value &Params, Range &R, llvm::json::Path P) {
 139   llvm::json::ObjectMapper O(Params, P);
 140   return O && O.map("start", R.start) && O.map("end", R.end);
 141 }
 142
 143 llvm::json::Value toJSON(const Range &P) {
 144   return llvm::json::Object{
 145       {"start", P.start},
 146       {"end", P.end},
 147   };
 148 }
 149
 150 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Range &R) {
 151   return OS << R.start << '-' << R.end;
 152 }
 153
 154 llvm::json::Value toJSON(const Location &P) {
 155   return llvm::json::Object{
 156       {"uri", P.uri},
 157       {"range", P.range},
 158   };
 159 }
 160
 161 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Location &L) {
 162   return OS << L.range << '@' << L.uri;
 163 }
 164
 165 llvm::json::Value toJSON(const ReferenceLocation &P) {
 166   llvm::json::Object Result{
 167       {"uri", P.uri},
 168       {"range", P.range},
 169   };
 170   if (P.containerName)
 171     Result.insert({"containerName", P.containerName});
 172   return Result;
 173 }
 174
 175 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
 176                               const ReferenceLocation &L) {
 177   return OS << L.range << '@' << L.uri << " (container: " << L.containerName
 178             << ")";
 179 }
 180
 181 bool fromJSON(const llvm::json::Value &Params, TextDocumentItem &R,
 182               llvm::json::Path P) {
 183   llvm::json::ObjectMapper O(Params, P);
 184   return O && O.map("uri", R.uri) && O.map("languageId", R.languageId) &&
 185          O.map("version", R.version) && O.map("text", R.text);
 186 }
 187
 188 bool fromJSON(const llvm::json::Value &Params, TextEdit &R,
 189               llvm::json::Path P) {
 190   llvm::json::ObjectMapper O(Params, P);
 191   return O && O.map("range", R.range) && O.map("newText", R.newText) &&
 192          O.mapOptional("annotationId", R.annotationId);
 193 }
 194
 195 llvm::json::Value toJSON(const TextEdit &P) {
 196   llvm::json::Object Result{
 197       {"range", P.range},
 198       {"newText", P.newText},
 199   };
 200   if (!P.annotationId.empty())
 201     Result["annotationId"] = P.annotationId;
 202   return Result;
 203 }
 204
 205 bool fromJSON(const llvm::json::Value &Params, ChangeAnnotation &R,
 206               llvm::json::Path P) {
 207   llvm::json::ObjectMapper O(Params, P);
 208   return O && O.map("label", R.label) &&
 209          O.map("needsConfirmation", R.needsConfirmation) &&
 210          O.mapOptional("description", R.description);
 211 }
 212 llvm::json::Value toJSON(const ChangeAnnotation & CA) {
 213   llvm::json::Object Result{{"label", CA.label}};
 214   if (CA.needsConfirmation)
 215     Result["needsConfirmation"] = *CA.needsConfirmation;
 216   if (!CA.description.empty())
 217     Result["description"] = CA.description;
 218   return Result;
 219 }
 220
 221 bool fromJSON(const llvm::json::Value &Params, TextDocumentEdit &R,
 222               llvm::json::Path P) {
 223   llvm::json::ObjectMapper O(Params, P);
 224   return O && O.map("textDocument", R.textDocument) && O.map("edits", R.edits);
 225 }
 226 llvm::json::Value toJSON(const TextDocumentEdit &P) {
 227   llvm::json::Object Result{{"textDocument", P.textDocument},
 228                             {"edits", P.edits}};
 229   return Result;
 230 }
 231
 232 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const TextEdit &TE) {
 233   OS << TE.range << " => \"";
 234   llvm::printEscapedString(TE.newText, OS);
 235   return OS << '"';
 236 }
 237
 238 bool fromJSON(const llvm::json::Value &E, TraceLevel &Out, llvm::json::Path P) {
 239   if (auto S = E.getAsString()) {
 240     if (*S == "off") {
 241       Out = TraceLevel::Off;
 242       return true;
 243     }
 244     if (*S == "messages") {
 245       Out = TraceLevel::Messages;
 246       return true;
 247     }
 248     if (*S == "verbose") {
 249       Out = TraceLevel::Verbose;
 250       return true;
 251     }
 252   }
 253   return false;
 254 }
 255
 256 bool fromJSON(const llvm::json::Value &E, SymbolKind &Out, llvm::json::Path P) {
 257   if (auto T = E.getAsInteger()) {
 258     if (*T < static_cast<int>(SymbolKind::File) ||
 259         *T > static_cast<int>(SymbolKind::TypeParameter))
 260       return false;
 261     Out = static_cast<SymbolKind>(*T);
 262     return true;
 263   }
 264   return false;
 265 }
 266
 267 bool fromJSON(const llvm::json::Value &E, SymbolKindBitset &Out,
 268               llvm::json::Path P) {
 269   if (auto *A = E.getAsArray()) {
 270     for (size_t I = 0; I < A->size(); ++I) {
 271       SymbolKind KindOut;
 272       if (fromJSON((*A)[I], KindOut, P.index(I)))
 273         Out.set(size_t(KindOut));
 274     }
 275     return true;
 276   }
 277   return false;
 278 }
 279
 280 SymbolKind adjustKindToCapability(SymbolKind Kind,
 281                                   SymbolKindBitset &SupportedSymbolKinds) {
 282   auto KindVal = static_cast<size_t>(Kind);
 283   if (KindVal >= SymbolKindMin && KindVal <= SupportedSymbolKinds.size() &&
 284       SupportedSymbolKinds[KindVal])
 285     return Kind;
 286
 287   switch (Kind) {
 288   // Provide some fall backs for common kinds that are close enough.
 289   case SymbolKind::Struct:
 290     return SymbolKind::Class;
 291   case SymbolKind::EnumMember:
 292     return SymbolKind::Enum;
 293   default:
 294     return SymbolKind::String;
 295   }
 296 }
 297
 298 SymbolKind indexSymbolKindToSymbolKind(index::SymbolKind Kind) {
 299   switch (Kind) {
 300   case index::SymbolKind::Unknown:
 301     return SymbolKind::Variable;
 302   case index::SymbolKind::Module:
 303     return SymbolKind::Module;
 304   case index::SymbolKind::Namespace:
 305     return SymbolKind::Namespace;
 306   case index::SymbolKind::NamespaceAlias:
 307     return SymbolKind::Namespace;
 308   case index::SymbolKind::Macro:
 309     return SymbolKind::String;
 310   case index::SymbolKind::Enum:
 311     return SymbolKind::Enum;
 312   case index::SymbolKind::Struct:
 313     return SymbolKind::Struct;
 314   case index::SymbolKind::Class:
 315     return SymbolKind::Class;
 316   case index::SymbolKind::Protocol:
 317     return SymbolKind::Interface;
 318   case index::SymbolKind::Extension:
 319     return SymbolKind::Interface;
 320   case index::SymbolKind::Union:
 321     return SymbolKind::Class;
 322   case index::SymbolKind::TypeAlias:
 323     return SymbolKind::Class;
 324   case index::SymbolKind::Function:
 325     return SymbolKind::Function;
 326   case index::SymbolKind::Variable:
 327     return SymbolKind::Variable;
 328   case index::SymbolKind::Field:
 329     return SymbolKind::Field;
 330   case index::SymbolKind::EnumConstant:
 331     return SymbolKind::EnumMember;
 332   case index::SymbolKind::InstanceMethod:
 333   case index::SymbolKind::ClassMethod:
 334   case index::SymbolKind::StaticMethod:
 335     return SymbolKind::Method;
 336   case index::SymbolKind::InstanceProperty:
 337   case index::SymbolKind::ClassProperty:
 338   case index::SymbolKind::StaticProperty:
 339     return SymbolKind::Property;
 340   case index::SymbolKind::Constructor:
 341   case index::SymbolKind::Destructor:
 342     return SymbolKind::Constructor;
 343   case index::SymbolKind::ConversionFunction:
 344     return SymbolKind::Function;
 345   case index::SymbolKind::Parameter:
 346   case index::SymbolKind::NonTypeTemplateParm:
 347     return SymbolKind::Variable;
 348   case index::SymbolKind::Using:
 349     return SymbolKind::Namespace;
 350   case index::SymbolKind::TemplateTemplateParm:
 351   case index::SymbolKind::TemplateTypeParm:
 352     return SymbolKind::TypeParameter;
 353   case index::SymbolKind::Concept:
 354     return SymbolKind::Interface;
 355   }
 356   llvm_unreachable("invalid symbol kind");
 357 }
 358
 359 bool fromJSON(const llvm::json::Value &Params, ClientCapabilities &R,
 360               llvm::json::Path P) {
 361   const llvm::json::Object *O = Params.getAsObject();
 362   if (!O) {
 363     P.report("expected object");
 364     return false;
 365   }
 366   if (auto *TextDocument = O->getObject("textDocument")) {
 367     if (auto *SemanticHighlighting =
 368             TextDocument->getObject("semanticHighlightingCapabilities")) {
 369       if (auto SemanticHighlightingSupport =
 370               SemanticHighlighting->getBoolean("semanticHighlighting"))
 371         R.TheiaSemanticHighlighting = *SemanticHighlightingSupport;
 372     }
 373     if (auto *InactiveRegions =
 374             TextDocument->getObject("inactiveRegionsCapabilities")) {
 375       if (auto InactiveRegionsSupport =
 376               InactiveRegions->getBoolean("inactiveRegions")) {
 377         R.InactiveRegions = *InactiveRegionsSupport;
 378       }
 379     }
 380     if (TextDocument->getObject("semanticTokens"))
 381       R.SemanticTokens = true;
 382     if (auto *Diagnostics = TextDocument->getObject("publishDiagnostics")) {
 383       if (auto CategorySupport = Diagnostics->getBoolean("categorySupport"))
 384         R.DiagnosticCategory = *CategorySupport;
 385       if (auto CodeActions = Diagnostics->getBoolean("codeActionsInline"))
 386         R.DiagnosticFixes = *CodeActions;
 387       if (auto RelatedInfo = Diagnostics->getBoolean("relatedInformation"))
 388         R.DiagnosticRelatedInformation = *RelatedInfo;
 389     }
 390     if (auto *References = TextDocument->getObject("references"))
 391       if (auto ContainerSupport = References->getBoolean("container"))
 392         R.ReferenceContainer = *ContainerSupport;
 393     if (auto *Completion = TextDocument->getObject("completion")) {
 394       if (auto *Item = Completion->getObject("completionItem")) {
 395         if (auto SnippetSupport = Item->getBoolean("snippetSupport"))
 396           R.CompletionSnippets = *SnippetSupport;
 397         if (auto LabelDetailsSupport = Item->getBoolean("labelDetailsSupport"))
 398           R.CompletionLabelDetail = *LabelDetailsSupport;
 399         if (const auto *DocumentationFormat =
 400                 Item->getArray("documentationFormat")) {
 401           for (const auto &Format : *DocumentationFormat) {
 402             if (fromJSON(Format, R.CompletionDocumentationFormat, P))
 403               break;
 404           }
 405         }
 406       }
 407       if (auto *ItemKind = Completion->getObject("completionItemKind")) {
 408         if (auto *ValueSet = ItemKind->get("valueSet")) {
 409           R.CompletionItemKinds.emplace();
 410           if (!fromJSON(*ValueSet, *R.CompletionItemKinds,
 411                         P.field("textDocument")
 412                             .field("completion")
 413                             .field("completionItemKind")
 414                             .field("valueSet")))
 415             return false;
 416         }
 417       }
 418       if (auto EditsNearCursor = Completion->getBoolean("editsNearCursor"))
 419         R.CompletionFixes = *EditsNearCursor;
 420     }
 421     if (auto *CodeAction = TextDocument->getObject("codeAction")) {
 422       if (CodeAction->getObject("codeActionLiteralSupport"))
 423         R.CodeActionStructure = true;
 424     }
 425     if (auto *DocumentSymbol = TextDocument->getObject("documentSymbol")) {
 426       if (auto HierarchicalSupport =
 427               DocumentSymbol->getBoolean("hierarchicalDocumentSymbolSupport"))
 428         R.HierarchicalDocumentSymbol = *HierarchicalSupport;
 429     }
 430     if (auto *Hover = TextDocument->getObject("hover")) {
 431       if (auto *ContentFormat = Hover->getArray("contentFormat")) {
 432         for (const auto &Format : *ContentFormat) {
 433           if (fromJSON(Format, R.HoverContentFormat, P))
 434             break;
 435         }
 436       }
 437     }
 438     if (auto *Help = TextDocument->getObject("signatureHelp")) {
 439       R.HasSignatureHelp = true;
 440       if (auto *Info = Help->getObject("signatureInformation")) {
 441         if (auto *Parameter = Info->getObject("parameterInformation")) {
 442           if (auto OffsetSupport = Parameter->getBoolean("labelOffsetSupport"))
 443             R.OffsetsInSignatureHelp = *OffsetSupport;
 444         }
 445         if (const auto *DocumentationFormat =
 446                 Info->getArray("documentationFormat")) {
 447           for (const auto &Format : *DocumentationFormat) {
 448             if (fromJSON(Format, R.SignatureHelpDocumentationFormat, P))
 449               break;
 450           }
 451         }
 452       }
 453     }
 454     if (auto *Folding = TextDocument->getObject("foldingRange")) {
 455       if (auto LineFolding = Folding->getBoolean("lineFoldingOnly"))
 456         R.LineFoldingOnly = *LineFolding;
 457     }
 458     if (auto *Rename = TextDocument->getObject("rename")) {
 459       if (auto RenameSupport = Rename->getBoolean("prepareSupport"))
 460         R.RenamePrepareSupport = *RenameSupport;
 461     }
 462   }
 463   if (auto *Workspace = O->getObject("workspace")) {
 464     if (auto *Symbol = Workspace->getObject("symbol")) {
 465       if (auto *SymbolKind = Symbol->getObject("symbolKind")) {
 466         if (auto *ValueSet = SymbolKind->get("valueSet")) {
 467           R.WorkspaceSymbolKinds.emplace();
 468           if (!fromJSON(*ValueSet, *R.WorkspaceSymbolKinds,
 469                         P.field("workspace")
 470                             .field("symbol")
 471                             .field("symbolKind")
 472                             .field("valueSet")))
 473             return false;
 474         }
 475       }
 476     }
 477     if (auto *SemanticTokens = Workspace->getObject("semanticTokens")) {
 478       if (auto RefreshSupport = SemanticTokens->getBoolean("refreshSupport"))
 479         R.SemanticTokenRefreshSupport = *RefreshSupport;
 480     }
 481     if (auto *WorkspaceEdit = Workspace->getObject("workspaceEdit")) {
 482       if (auto DocumentChanges = WorkspaceEdit->getBoolean("documentChanges"))
 483         R.DocumentChanges = *DocumentChanges;
 484       if (WorkspaceEdit->getObject("changeAnnotationSupport")) {
 485         R.ChangeAnnotation = true;
 486       }
 487     }
 488   }
 489   if (auto *Window = O->getObject("window")) {
 490     if (auto WorkDoneProgress = Window->getBoolean("workDoneProgress"))
 491       R.WorkDoneProgress = *WorkDoneProgress;
 492     if (auto Implicit = Window->getBoolean("implicitWorkDoneProgressCreate"))
 493       R.ImplicitProgressCreation = *Implicit;
 494   }
 495   if (auto *General = O->getObject("general")) {
 496     if (auto *StaleRequestSupport = General->getObject("staleRequestSupport")) {
 497       if (auto Cancel = StaleRequestSupport->getBoolean("cancel"))
 498         R.CancelsStaleRequests = *Cancel;
 499     }
 500   }
 501   if (auto *OffsetEncoding = O->get("offsetEncoding")) {
 502     R.offsetEncoding.emplace();
 503     if (!fromJSON(*OffsetEncoding, *R.offsetEncoding,
 504                   P.field("offsetEncoding")))
 505       return false;
 506   }
 507   return true;
 508 }
 509
 510 bool fromJSON(const llvm::json::Value &Params, InitializeParams &R,
 511               llvm::json::Path P) {
 512   llvm::json::ObjectMapper O(Params, P);
 513   if (!O)
 514     return false;
 515   // We deliberately don't fail if we can't parse individual fields.
 516   // Failing to handle a slightly malformed initialize would be a disaster.
 517   O.map("processId", R.processId);
 518   O.map("rootUri", R.rootUri);
 519   O.map("rootPath", R.rootPath);
 520   O.map("capabilities", R.capabilities);
 521   if (auto *RawCaps = Params.getAsObject()->getObject("capabilities"))
 522     R.rawCapabilities = *RawCaps;
 523   O.map("trace", R.trace);
 524   O.map("initializationOptions", R.initializationOptions);
 525   return true;
 526 }
 527
 528 llvm::json::Value toJSON(const WorkDoneProgressCreateParams &P) {
 529   return llvm::json::Object{{"token", P.token}};
 530 }
 531
 532 llvm::json::Value toJSON(const WorkDoneProgressBegin &P) {
 533   llvm::json::Object Result{
 534       {"kind", "begin"},
 535       {"title", P.title},
 536   };
 537   if (P.cancellable)
 538     Result["cancellable"] = true;
 539   if (P.percentage)
 540     Result["percentage"] = 0;
 541
 542   // FIXME: workaround for older gcc/clang
 543   return std::move(Result);
 544 }
 545
 546 llvm::json::Value toJSON(const WorkDoneProgressReport &P) {
 547   llvm::json::Object Result{{"kind", "report"}};
 548   if (P.cancellable)
 549     Result["cancellable"] = *P.cancellable;
 550   if (P.message)
 551     Result["message"] = *P.message;
 552   if (P.percentage)
 553     Result["percentage"] = *P.percentage;
 554   // FIXME: workaround for older gcc/clang
 555   return std::move(Result);
 556 }
 557
 558 llvm::json::Value toJSON(const WorkDoneProgressEnd &P) {
 559   llvm::json::Object Result{{"kind", "end"}};
 560   if (P.message)
 561     Result["message"] = *P.message;
 562   // FIXME: workaround for older gcc/clang
 563   return std::move(Result);
 564 }
 565
 566 llvm::json::Value toJSON(const MessageType &R) {
 567   return static_cast<int64_t>(R);
 568 }
 569
 570 llvm::json::Value toJSON(const ShowMessageParams &R) {
 571   return llvm::json::Object{{"type", R.type}, {"message", R.message}};
 572 }
 573
 574 bool fromJSON(const llvm::json::Value &Params, DidOpenTextDocumentParams &R,
 575               llvm::json::Path P) {
 576   llvm::json::ObjectMapper O(Params, P);
 577   return O && O.map("textDocument", R.textDocument);
 578 }
 579
 580 bool fromJSON(const llvm::json::Value &Params, DidCloseTextDocumentParams &R,
 581               llvm::json::Path P) {
 582   llvm::json::ObjectMapper O(Params, P);
 583   return O && O.map("textDocument", R.textDocument);
 584 }
 585
 586 bool fromJSON(const llvm::json::Value &Params, DidSaveTextDocumentParams &R,
 587               llvm::json::Path P) {
 588   llvm::json::ObjectMapper O(Params, P);
 589   return O && O.map("textDocument", R.textDocument);
 590 }
 591
 592 bool fromJSON(const llvm::json::Value &Params, DidChangeTextDocumentParams &R,
 593               llvm::json::Path P) {
 594   llvm::json::ObjectMapper O(Params, P);
 595   return O && O.map("textDocument", R.textDocument) &&
 596          O.map("contentChanges", R.contentChanges) &&
 597          O.map("wantDiagnostics", R.wantDiagnostics) &&
 598          mapOptOrNull(Params, "forceRebuild", R.forceRebuild, P);
 599 }
 600
 601 bool fromJSON(const llvm::json::Value &E, FileChangeType &Out,
 602               llvm::json::Path P) {
 603   if (auto T = E.getAsInteger()) {
 604     if (*T < static_cast<int>(FileChangeType::Created) ||
 605         *T > static_cast<int>(FileChangeType::Deleted))
 606       return false;
 607     Out = static_cast<FileChangeType>(*T);
 608     return true;
 609   }
 610   return false;
 611 }
 612
 613 bool fromJSON(const llvm::json::Value &Params, FileEvent &R,
 614               llvm::json::Path P) {
 615   llvm::json::ObjectMapper O(Params, P);
 616   return O && O.map("uri", R.uri) && O.map("type", R.type);
 617 }
 618
 619 bool fromJSON(const llvm::json::Value &Params, DidChangeWatchedFilesParams &R,
 620               llvm::json::Path P) {
 621   llvm::json::ObjectMapper O(Params, P);
 622   return O && O.map("changes", R.changes);
 623 }
 624
 625 bool fromJSON(const llvm::json::Value &Params,
 626               TextDocumentContentChangeEvent &R, llvm::json::Path P) {
 627   llvm::json::ObjectMapper O(Params, P);
 628   return O && O.map("range", R.range) && O.map("rangeLength", R.rangeLength) &&
 629          O.map("text", R.text);
 630 }
 631
 632 bool fromJSON(const llvm::json::Value &Params, DocumentRangeFormattingParams &R,
 633               llvm::json::Path P) {
 634   llvm::json::ObjectMapper O(Params, P);
 635   return O && O.map("textDocument", R.textDocument) && O.map("range", R.range);
 636 }
 637
 638 bool fromJSON(const llvm::json::Value &Params,
 639               DocumentOnTypeFormattingParams &R, llvm::json::Path P) {
 640   llvm::json::ObjectMapper O(Params, P);
 641   return O && O.map("textDocument", R.textDocument) &&
 642          O.map("position", R.position) && O.map("ch", R.ch);
 643 }
 644
 645 bool fromJSON(const llvm::json::Value &Params, DocumentFormattingParams &R,
 646               llvm::json::Path P) {
 647   llvm::json::ObjectMapper O(Params, P);
 648   return O && O.map("textDocument", R.textDocument);
 649 }
 650
 651 bool fromJSON(const llvm::json::Value &Params, DocumentSymbolParams &R,
 652               llvm::json::Path P) {
 653   llvm::json::ObjectMapper O(Params, P);
 654   return O && O.map("textDocument", R.textDocument);
 655 }
 656
 657 llvm::json::Value toJSON(const DiagnosticRelatedInformation &DRI) {
 658   return llvm::json::Object{
 659       {"location", DRI.location},
 660       {"message", DRI.message},
 661   };
 662 }
 663
 664 llvm::json::Value toJSON(DiagnosticTag Tag) { return static_cast<int>(Tag); }
 665
 666 llvm::json::Value toJSON(const CodeDescription &D) {
 667   return llvm::json::Object{{"href", D.href}};
 668 }
 669
 670 llvm::json::Value toJSON(const Diagnostic &D) {
 671   llvm::json::Object Diag{
 672       {"range", D.range},
 673       {"severity", D.severity},
 674       {"message", D.message},
 675   };
 676   if (D.category)
 677     Diag["category"] = *D.category;
 678   if (D.codeActions)
 679     Diag["codeActions"] = D.codeActions;
 680   if (!D.code.empty())
 681     Diag["code"] = D.code;
 682   if (D.codeDescription)
 683     Diag["codeDescription"] = *D.codeDescription;
 684   if (!D.source.empty())
 685     Diag["source"] = D.source;
 686   if (D.relatedInformation)
 687     Diag["relatedInformation"] = *D.relatedInformation;
 688   if (!D.data.empty())
 689     Diag["data"] = llvm::json::Object(D.data);
 690   if (!D.tags.empty())
 691     Diag["tags"] = llvm::json::Array{D.tags};
 692   // FIXME: workaround for older gcc/clang
 693   return std::move(Diag);
 694 }
 695
 696 bool fromJSON(const llvm::json::Value &Params, Diagnostic &R,
 697               llvm::json::Path P) {
 698   llvm::json::ObjectMapper O(Params, P);
 699   if (!O)
 700     return false;
 701   if (auto *Data = Params.getAsObject()->getObject("data"))
 702     R.data = *Data;
 703   return O.map("range", R.range) && O.map("message", R.message) &&
 704          mapOptOrNull(Params, "severity", R.severity, P) &&
 705          mapOptOrNull(Params, "category", R.category, P) &&
 706          mapOptOrNull(Params, "code", R.code, P) &&
 707          mapOptOrNull(Params, "source", R.source, P);
 708 }
 709
 710 llvm::json::Value toJSON(const PublishDiagnosticsParams &PDP) {
 711   llvm::json::Object Result{
 712       {"uri", PDP.uri},
 713       {"diagnostics", PDP.diagnostics},
 714   };
 715   if (PDP.version)
 716     Result["version"] = PDP.version;
 717   return std::move(Result);
 718 }
 719
 720 bool fromJSON(const llvm::json::Value &Params, CodeActionContext &R,
 721               llvm::json::Path P) {
 722   llvm::json::ObjectMapper O(Params, P);
 723   if (!O || !O.map("diagnostics", R.diagnostics))
 724     return false;
 725   O.map("only", R.only);
 726   return true;
 727 }
 728
 729 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Diagnostic &D) {
 730   OS << D.range << " [";
 731   switch (D.severity) {
 732   case 1:
 733     OS << "error";
 734     break;
 735   case 2:
 736     OS << "warning";
 737     break;
 738   case 3:
 739     OS << "note";
 740     break;
 741   case 4:
 742     OS << "remark";
 743     break;
 744   default:
 745     OS << "diagnostic";
 746     break;
 747   }
 748   return OS << '(' << D.severity << "): " << D.message << "]";
 749 }
 750
 751 bool fromJSON(const llvm::json::Value &Params, CodeActionParams &R,
 752               llvm::json::Path P) {
 753   llvm::json::ObjectMapper O(Params, P);
 754   return O && O.map("textDocument", R.textDocument) &&
 755          O.map("range", R.range) && O.map("context", R.context);
 756 }
 757
 758 bool fromJSON(const llvm::json::Value &Params, WorkspaceEdit &R,
 759               llvm::json::Path P) {
 760   llvm::json::ObjectMapper O(Params, P);
 761   return O && O.map("changes", R.changes) &&
 762          O.map("documentChanges", R.documentChanges) &&
 763          O.mapOptional("changeAnnotations", R.changeAnnotations);
 764 }
 765
 766 bool fromJSON(const llvm::json::Value &Params, ExecuteCommandParams &R,
 767               llvm::json::Path P) {
 768   llvm::json::ObjectMapper O(Params, P);
 769   if (!O || !O.map("command", R.command))
 770     return false;
 771
 772   const auto *Args = Params.getAsObject()->get("arguments");
 773   if (!Args)
 774     return true; // Missing args is ok, argument is null.
 775   const auto *ArgsArray = Args->getAsArray();
 776   if (!ArgsArray) {
 777     P.field("arguments").report("expected array");
 778     return false;
 779   }
 780   if (ArgsArray->size() > 1) {
 781     P.field("arguments").report("Command should have 0 or 1 argument");
 782     return false;
 783   }
 784   if (ArgsArray->size() == 1) {
 785     R.argument = ArgsArray->front();
 786   }
 787   return true;
 788 }
 789
 790 llvm::json::Value toJSON(const SymbolInformation &P) {
 791   llvm::json::Object O{
 792       {"name", P.name},
 793       {"kind", static_cast<int>(P.kind)},
 794       {"location", P.location},
 795       {"containerName", P.containerName},
 796   };
 797   if (P.score)
 798     O["score"] = *P.score;
 799   return std::move(O);
 800 }
 801
 802 llvm::raw_ostream &operator<<(llvm::raw_ostream &O,
 803                               const SymbolInformation &SI) {
 804   O << SI.containerName << "::" << SI.name << " - " << toJSON(SI);
 805   return O;
 806 }
 807
 808 bool operator==(const SymbolDetails &LHS, const SymbolDetails &RHS) {
 809   return LHS.name == RHS.name && LHS.containerName == RHS.containerName &&
 810          LHS.USR == RHS.USR && LHS.ID == RHS.ID &&
 811          LHS.declarationRange == RHS.declarationRange &&
 812          LHS.definitionRange == RHS.definitionRange;
 813 }
 814
 815 llvm::json::Value toJSON(const SymbolDetails &P) {
 816   llvm::json::Object Result{{"name", llvm::json::Value(nullptr)},
 817                             {"containerName", llvm::json::Value(nullptr)},
 818                             {"usr", llvm::json::Value(nullptr)},
 819                             {"id", llvm::json::Value(nullptr)}};
 820
 821   if (!P.name.empty())
 822     Result["name"] = P.name;
 823
 824   if (!P.containerName.empty())
 825     Result["containerName"] = P.containerName;
 826
 827   if (!P.USR.empty())
 828     Result["usr"] = P.USR;
 829
 830   if (P.ID)
 831     Result["id"] = P.ID.str();
 832
 833   if (P.declarationRange)
 834     Result["declarationRange"] = *P.declarationRange;
 835
 836   if (P.definitionRange)
 837     Result["definitionRange"] = *P.definitionRange;
 838
 839   // FIXME: workaround for older gcc/clang
 840   return std::move(Result);
 841 }
 842
 843 llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const SymbolDetails &S) {
 844   if (!S.containerName.empty()) {
 845     O << S.containerName;
 846     llvm::StringRef ContNameRef;
 847     if (!ContNameRef.ends_with("::")) {
 848       O << " ";
 849     }
 850   }
 851   O << S.name << " - " << toJSON(S);
 852   return O;
 853 }
 854
 855 bool fromJSON(const llvm::json::Value &Params, WorkspaceSymbolParams &R,
 856               llvm::json::Path P) {
 857   llvm::json::ObjectMapper O(Params, P);
 858   return O && O.map("query", R.query) &&
 859          mapOptOrNull(Params, "limit", R.limit, P);
 860 }
 861
 862 llvm::json::Value toJSON(const Command &C) {
 863   auto Cmd = llvm::json::Object{{"title", C.title}, {"command", C.command}};
 864   if (!C.argument.getAsNull())
 865     Cmd["arguments"] = llvm::json::Array{C.argument};
 866   return std::move(Cmd);
 867 }
 868
 869 const llvm::StringLiteral CodeAction::QUICKFIX_KIND = "quickfix";
 870 const llvm::StringLiteral CodeAction::REFACTOR_KIND = "refactor";
 871 const llvm::StringLiteral CodeAction::INFO_KIND = "info";
 872
 873 llvm::json::Value toJSON(const CodeAction &CA) {
 874   auto CodeAction = llvm::json::Object{{"title", CA.title}};
 875   if (CA.kind)
 876     CodeAction["kind"] = *CA.kind;
 877   if (CA.diagnostics)
 878     CodeAction["diagnostics"] = llvm::json::Array(*CA.diagnostics);
 879   if (CA.isPreferred)
 880     CodeAction["isPreferred"] = true;
 881   if (CA.edit)
 882     CodeAction["edit"] = *CA.edit;
 883   if (CA.command)
 884     CodeAction["command"] = *CA.command;
 885   return std::move(CodeAction);
 886 }
 887
 888 llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const DocumentSymbol &S) {
 889   return O << S.name << " - " << toJSON(S);
 890 }
 891
 892 llvm::json::Value toJSON(const DocumentSymbol &S) {
 893   llvm::json::Object Result{{"name", S.name},
 894                             {"kind", static_cast<int>(S.kind)},
 895                             {"range", S.range},
 896                             {"selectionRange", S.selectionRange}};
 897
 898   if (!S.detail.empty())
 899     Result["detail"] = S.detail;
 900   if (!S.children.empty())
 901     Result["children"] = S.children;
 902   if (S.deprecated)
 903     Result["deprecated"] = true;
 904   // FIXME: workaround for older gcc/clang
 905   return std::move(Result);
 906 }
 907
 908 llvm::json::Value toJSON(const WorkspaceEdit &WE) {
 909   llvm::json::Object Result;
 910   if (WE.changes) {
 911     llvm::json::Object FileChanges;
 912     for (auto &Change : *WE.changes)
 913       FileChanges[Change.first] = llvm::json::Array(Change.second);
 914     Result["changes"] = std::move(FileChanges);
 915   }
 916   if (WE.documentChanges)
 917     Result["documentChanges"] = *WE.documentChanges;
 918   if (!WE.changeAnnotations.empty()) {
 919     llvm::json::Object ChangeAnnotations;
 920     for (auto &Annotation : WE.changeAnnotations)
 921       ChangeAnnotations[Annotation.first] = Annotation.second;
 922     Result["changeAnnotations"] = std::move(ChangeAnnotations);
 923   }
 924   return Result;
 925 }
 926
 927 bool fromJSON(const llvm::json::Value &Params, TweakArgs &A,
 928               llvm::json::Path P) {
 929   llvm::json::ObjectMapper O(Params, P);
 930   return O && O.map("file", A.file) && O.map("selection", A.selection) &&
 931          O.map("tweakID", A.tweakID);
 932 }
 933
 934 llvm::json::Value toJSON(const TweakArgs &A) {
 935   return llvm::json::Object{
 936       {"tweakID", A.tweakID}, {"selection", A.selection}, {"file", A.file}};
 937 }
 938
 939 llvm::json::Value toJSON(const ApplyWorkspaceEditParams &Params) {
 940   return llvm::json::Object{{"edit", Params.edit}};
 941 }
 942
 943 bool fromJSON(const llvm::json::Value &Response, ApplyWorkspaceEditResponse &R,
 944               llvm::json::Path P) {
 945   llvm::json::ObjectMapper O(Response, P);
 946   return O && O.map("applied", R.applied) &&
 947          O.map("failureReason", R.failureReason);
 948 }
 949
 950 bool fromJSON(const llvm::json::Value &Params, TextDocumentPositionParams &R,
 951               llvm::json::Path P) {
 952   llvm::json::ObjectMapper O(Params, P);
 953   return O && O.map("textDocument", R.textDocument) &&
 954          O.map("position", R.position);
 955 }
 956
 957 bool fromJSON(const llvm::json::Value &Params, CompletionContext &R,
 958               llvm::json::Path P) {
 959   llvm::json::ObjectMapper O(Params, P);
 960   int TriggerKind;
 961   if (!O || !O.map("triggerKind", TriggerKind) ||
 962       !mapOptOrNull(Params, "triggerCharacter", R.triggerCharacter, P))
 963     return false;
 964   R.triggerKind = static_cast<CompletionTriggerKind>(TriggerKind);
 965   return true;
 966 }
 967
 968 bool fromJSON(const llvm::json::Value &Params, CompletionParams &R,
 969               llvm::json::Path P) {
 970   if (!fromJSON(Params, static_cast<TextDocumentPositionParams &>(R), P) ||
 971       !mapOptOrNull(Params, "limit", R.limit, P))
 972     return false;
 973   if (auto *Context = Params.getAsObject()->get("context"))
 974     return fromJSON(*Context, R.context, P.field("context"));
 975   return true;
 976 }
 977
 978 static llvm::StringRef toTextKind(MarkupKind Kind) {
 979   switch (Kind) {
 980   case MarkupKind::PlainText:
 981     return "plaintext";
 982   case MarkupKind::Markdown:
 983     return "markdown";
 984   }
 985   llvm_unreachable("Invalid MarkupKind");
 986 }
 987
 988 bool fromJSON(const llvm::json::Value &V, MarkupKind &K, llvm::json::Path P) {
 989   auto Str = V.getAsString();
 990   if (!Str) {
 991     P.report("expected string");
 992     return false;
 993   }
 994   if (*Str == "plaintext")
 995     K = MarkupKind::PlainText;
 996   else if (*Str == "markdown")
 997     K = MarkupKind::Markdown;
 998   else {
 999     P.report("unknown markup kind");
1000     return false;
1001   }
1002   return true;
1003 }
1004
1005 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, MarkupKind K) {
1006   return OS << toTextKind(K);
1007 }
1008
1009 llvm::json::Value toJSON(const MarkupContent &MC) {
1010   if (MC.value.empty())
1011     return nullptr;
1012
1013   return llvm::json::Object{
1014       {"kind", toTextKind(MC.kind)},
1015       {"value", MC.value},
1016   };
1017 }
1018
1019 llvm::json::Value toJSON(const Hover &H) {
1020   llvm::json::Object Result{{"contents", toJSON(H.contents)}};
1021
1022   if (H.range)
1023     Result["range"] = toJSON(*H.range);
1024
1025   return std::move(Result);
1026 }
1027
1028 bool fromJSON(const llvm::json::Value &E, CompletionItemKind &Out,
1029               llvm::json::Path P) {
1030   if (auto T = E.getAsInteger()) {
1031     if (*T < static_cast<int>(CompletionItemKind::Text) ||
1032         *T > static_cast<int>(CompletionItemKind::TypeParameter))
1033       return false;
1034     Out = static_cast<CompletionItemKind>(*T);
1035     return true;
1036   }
1037   return false;
1038 }
1039
1040 CompletionItemKind
1041 adjustKindToCapability(CompletionItemKind Kind,
1042                        CompletionItemKindBitset &SupportedCompletionItemKinds) {
1043   auto KindVal = static_cast<size_t>(Kind);
1044   if (KindVal >= CompletionItemKindMin &&
1045       KindVal <= SupportedCompletionItemKinds.size() &&
1046       SupportedCompletionItemKinds[KindVal])
1047     return Kind;
1048
1049   switch (Kind) {
1050   // Provide some fall backs for common kinds that are close enough.
1051   case CompletionItemKind::Folder:
1052     return CompletionItemKind::File;
1053   case CompletionItemKind::EnumMember:
1054     return CompletionItemKind::Enum;
1055   case CompletionItemKind::Struct:
1056     return CompletionItemKind::Class;
1057   default:
1058     return CompletionItemKind::Text;
1059   }
1060 }
1061
1062 bool fromJSON(const llvm::json::Value &E, CompletionItemKindBitset &Out,
1063               llvm::json::Path P) {
1064   if (auto *A = E.getAsArray()) {
1065     for (size_t I = 0; I < A->size(); ++I) {
1066       CompletionItemKind KindOut;
1067       if (fromJSON((*A)[I], KindOut, P.index(I)))
1068         Out.set(size_t(KindOut));
1069     }
1070     return true;
1071   }
1072   return false;
1073 }
1074
1075 llvm::json::Value toJSON(const CompletionItemLabelDetails &CD) {
1076   llvm::json::Object Result;
1077   if (!CD.detail.empty())
1078     Result["detail"] = CD.detail;
1079   if (!CD.description.empty())
1080     Result["description"] = CD.description;
1081   return Result;
1082 }
1083
1084 void removeCompletionLabelDetails(CompletionItem &C) {
1085   if (!C.labelDetails)
1086     return;
1087   if (!C.labelDetails->detail.empty())
1088     C.label += C.labelDetails->detail;
1089   if (!C.labelDetails->description.empty())
1090     C.label = C.labelDetails->description + C.label;
1091   C.labelDetails.reset();
1092 }
1093
1094 llvm::json::Value toJSON(const CompletionItem &CI) {
1095   assert(!CI.label.empty() && "completion item label is required");
1096   llvm::json::Object Result{{"label", CI.label}};
1097   if (CI.kind != CompletionItemKind::Missing)
1098     Result["kind"] = static_cast<int>(CI.kind);
1099   if (!CI.detail.empty())
1100     Result["detail"] = CI.detail;
1101   if (CI.labelDetails)
1102     Result["labelDetails"] = *CI.labelDetails;
1103   if (CI.documentation)
1104     Result["documentation"] = CI.documentation;
1105   if (!CI.sortText.empty())
1106     Result["sortText"] = CI.sortText;
1107   if (!CI.filterText.empty())
1108     Result["filterText"] = CI.filterText;
1109   if (!CI.insertText.empty())
1110     Result["insertText"] = CI.insertText;
1111   if (CI.insertTextFormat != InsertTextFormat::Missing)
1112     Result["insertTextFormat"] = static_cast<int>(CI.insertTextFormat);
1113   if (CI.textEdit)
1114     Result["textEdit"] = *CI.textEdit;
1115   if (!CI.additionalTextEdits.empty())
1116     Result["additionalTextEdits"] = llvm::json::Array(CI.additionalTextEdits);
1117   if (CI.deprecated)
1118     Result["deprecated"] = CI.deprecated;
1119   Result["score"] = CI.score;
1120   return std::move(Result);
1121 }
1122
1123 llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const CompletionItem &I) {
1124   O << I.label << " - " << toJSON(I);
1125   return O;
1126 }
1127
1128 bool operator<(const CompletionItem &L, const CompletionItem &R) {
1129   return (L.sortText.empty() ? L.label : L.sortText) <
1130          (R.sortText.empty() ? R.label : R.sortText);
1131 }
1132
1133 llvm::json::Value toJSON(const CompletionList &L) {
1134   return llvm::json::Object{
1135       {"isIncomplete", L.isIncomplete},
1136       {"items", llvm::json::Array(L.items)},
1137   };
1138 }
1139
1140 llvm::json::Value toJSON(const ParameterInformation &PI) {
1141   assert((PI.labelOffsets || !PI.labelString.empty()) &&
1142          "parameter information label is required");
1143   llvm::json::Object Result;
1144   if (PI.labelOffsets)
1145     Result["label"] =
1146         llvm::json::Array({PI.labelOffsets->first, PI.labelOffsets->second});
1147   else
1148     Result["label"] = PI.labelString;
1149   if (!PI.documentation.empty())
1150     Result["documentation"] = PI.documentation;
1151   return std::move(Result);
1152 }
1153
1154 llvm::json::Value toJSON(const SignatureInformation &SI) {
1155   assert(!SI.label.empty() && "signature information label is required");
1156   llvm::json::Object Result{
1157       {"label", SI.label},
1158       {"parameters", llvm::json::Array(SI.parameters)},
1159   };
1160   if (!SI.documentation.value.empty())
1161     Result["documentation"] = SI.documentation;
1162   return std::move(Result);
1163 }
1164
1165 llvm::raw_ostream &operator<<(llvm::raw_ostream &O,
1166                               const SignatureInformation &I) {
1167   O << I.label << " - " << toJSON(I);
1168   return O;
1169 }
1170
1171 llvm::json::Value toJSON(const SignatureHelp &SH) {
1172   assert(SH.activeSignature >= 0 &&
1173          "Unexpected negative value for number of active signatures.");
1174   assert(SH.activeParameter >= 0 &&
1175          "Unexpected negative value for active parameter index");
1176   return llvm::json::Object{
1177       {"activeSignature", SH.activeSignature},
1178       {"activeParameter", SH.activeParameter},
1179       {"signatures", llvm::json::Array(SH.signatures)},
1180   };
1181 }
1182
1183 bool fromJSON(const llvm::json::Value &Params, RenameParams &R,
1184               llvm::json::Path P) {
1185   llvm::json::ObjectMapper O(Params, P);
1186   return O && O.map("textDocument", R.textDocument) &&
1187          O.map("position", R.position) && O.map("newName", R.newName);
1188 }
1189
1190 llvm::json::Value toJSON(const RenameParams &R) {
1191   return llvm::json::Object{
1192       {"textDocument", R.textDocument},
1193       {"position", R.position},
1194       {"newName", R.newName},
1195   };
1196 }
1197
1198 llvm::json::Value toJSON(const PrepareRenameResult &PRR) {
1199   if (PRR.placeholder.empty())
1200     return toJSON(PRR.range);
1201   return llvm::json::Object{
1202       {"range", toJSON(PRR.range)},
1203       {"placeholder", PRR.placeholder},
1204   };
1205 }
1206
1207 llvm::json::Value toJSON(const DocumentHighlight &DH) {
1208   return llvm::json::Object{
1209       {"range", toJSON(DH.range)},
1210       {"kind", static_cast<int>(DH.kind)},
1211   };
1212 }
1213
1214 llvm::json::Value toJSON(const FileStatus &FStatus) {
1215   return llvm::json::Object{
1216       {"uri", FStatus.uri},
1217       {"state", FStatus.state},
1218   };
1219 }
1220
1221 constexpr unsigned SemanticTokenEncodingSize = 5;
1222 static llvm::json::Value encodeTokens(llvm::ArrayRef<SemanticToken> Toks) {
1223   llvm::json::Array Result;
1224   Result.reserve(SemanticTokenEncodingSize * Toks.size());
1225   for (const auto &Tok : Toks) {
1226     Result.push_back(Tok.deltaLine);
1227     Result.push_back(Tok.deltaStart);
1228     Result.push_back(Tok.length);
1229     Result.push_back(Tok.tokenType);
1230     Result.push_back(Tok.tokenModifiers);
1231   }
1232   assert(Result.size() == SemanticTokenEncodingSize * Toks.size());
1233   return std::move(Result);
1234 }
1235
1236 bool operator==(const SemanticToken &L, const SemanticToken &R) {
1237   return std::tie(L.deltaLine, L.deltaStart, L.length, L.tokenType,
1238                   L.tokenModifiers) == std::tie(R.deltaLine, R.deltaStart,
1239                                                 R.length, R.tokenType,
1240                                                 R.tokenModifiers);
1241 }
1242
1243 llvm::json::Value toJSON(const SemanticTokens &Tokens) {
1244   return llvm::json::Object{{"resultId", Tokens.resultId},
1245                             {"data", encodeTokens(Tokens.tokens)}};
1246 }
1247
1248 llvm::json::Value toJSON(const SemanticTokensEdit &Edit) {
1249   return llvm::json::Object{
1250       {"start", SemanticTokenEncodingSize * Edit.startToken},
1251       {"deleteCount", SemanticTokenEncodingSize * Edit.deleteTokens},
1252       {"data", encodeTokens(Edit.tokens)}};
1253 }
1254
1255 llvm::json::Value toJSON(const SemanticTokensOrDelta &TE) {
1256   llvm::json::Object Result{{"resultId", TE.resultId}};
1257   if (TE.edits)
1258     Result["edits"] = *TE.edits;
1259   if (TE.tokens)
1260     Result["data"] = encodeTokens(*TE.tokens);
1261   return std::move(Result);
1262 }
1263
1264 bool fromJSON(const llvm::json::Value &Params, SemanticTokensParams &R,
1265               llvm::json::Path P) {
1266   llvm::json::ObjectMapper O(Params, P);
1267   return O && O.map("textDocument", R.textDocument);
1268 }
1269
1270 bool fromJSON(const llvm::json::Value &Params, SemanticTokensDeltaParams &R,
1271               llvm::json::Path P) {
1272   llvm::json::ObjectMapper O(Params, P);
1273   return O && O.map("textDocument", R.textDocument) &&
1274          O.map("previousResultId", R.previousResultId);
1275 }
1276
1277 llvm::json::Value toJSON(const InactiveRegionsParams &InactiveRegions) {
1278   return llvm::json::Object{
1279       {"textDocument", InactiveRegions.TextDocument},
1280       {"regions", std::move(InactiveRegions.InactiveRegions)}};
1281 }
1282
1283 llvm::raw_ostream &operator<<(llvm::raw_ostream &O,
1284                               const DocumentHighlight &V) {
1285   O << V.range;
1286   if (V.kind == DocumentHighlightKind::Read)
1287     O << "(r)";
1288   if (V.kind == DocumentHighlightKind::Write)
1289     O << "(w)";
1290   return O;
1291 }
1292
1293 bool fromJSON(const llvm::json::Value &Params,
1294               DidChangeConfigurationParams &CCP, llvm::json::Path P) {
1295   llvm::json::ObjectMapper O(Params, P);
1296   return O && O.map("settings", CCP.settings);
1297 }
1298
1299 bool fromJSON(const llvm::json::Value &Params, ClangdCompileCommand &CDbUpdate,
1300               llvm::json::Path P) {
1301   llvm::json::ObjectMapper O(Params, P);
1302   return O && O.map("workingDirectory", CDbUpdate.workingDirectory) &&
1303          O.map("compilationCommand", CDbUpdate.compilationCommand);
1304 }
1305
1306 bool fromJSON(const llvm::json::Value &Params, ConfigurationSettings &S,
1307               llvm::json::Path P) {
1308   llvm::json::ObjectMapper O(Params, P);
1309   if (!O)
1310     return true; // 'any' type in LSP.
1311   return mapOptOrNull(Params, "compilationDatabaseChanges",
1312                       S.compilationDatabaseChanges, P);
1313 }
1314
1315 bool fromJSON(const llvm::json::Value &Params, InitializationOptions &Opts,
1316               llvm::json::Path P) {
1317   llvm::json::ObjectMapper O(Params, P);
1318   if (!O)
1319     return true; // 'any' type in LSP.
1320
1321   return fromJSON(Params, Opts.ConfigSettings, P) &&
1322          O.map("compilationDatabasePath", Opts.compilationDatabasePath) &&
1323          mapOptOrNull(Params, "fallbackFlags", Opts.fallbackFlags, P) &&
1324          mapOptOrNull(Params, "clangdFileStatus", Opts.FileStatus, P);
1325 }
1326
1327 bool fromJSON(const llvm::json::Value &E, TypeHierarchyDirection &Out,
1328               llvm::json::Path P) {
1329   auto T = E.getAsInteger();
1330   if (!T)
1331     return false;
1332   if (*T < static_cast<int>(TypeHierarchyDirection::Children) ||
1333       *T > static_cast<int>(TypeHierarchyDirection::Both))
1334     return false;
1335   Out = static_cast<TypeHierarchyDirection>(*T);
1336   return true;
1337 }
1338
1339 bool fromJSON(const llvm::json::Value &Params, TypeHierarchyPrepareParams &R,
1340               llvm::json::Path P) {
1341   llvm::json::ObjectMapper O(Params, P);
1342   return O && O.map("textDocument", R.textDocument) &&
1343          O.map("position", R.position) &&
1344          mapOptOrNull(Params, "resolve", R.resolve, P) &&
1345          mapOptOrNull(Params, "direction", R.direction, P);
1346 }
1347
1348 llvm::raw_ostream &operator<<(llvm::raw_ostream &O,
1349                               const TypeHierarchyItem &I) {
1350   return O << I.name << " - " << toJSON(I);
1351 }
1352
1353 llvm::json::Value toJSON(const TypeHierarchyItem::ResolveParams &RP) {
1354   llvm::json::Object Result{{"symbolID", RP.symbolID}};
1355   if (RP.parents)
1356     Result["parents"] = RP.parents;
1357   return std::move(Result);
1358 }
1359 bool fromJSON(const llvm::json::Value &Params,
1360               TypeHierarchyItem::ResolveParams &RP, llvm::json::Path P) {
1361   llvm::json::ObjectMapper O(Params, P);
1362   return O && O.map("symbolID", RP.symbolID) &&
1363          mapOptOrNull(Params, "parents", RP.parents, P);
1364 }
1365
1366 llvm::json::Value toJSON(const TypeHierarchyItem &I) {
1367   llvm::json::Object Result{
1368       {"name", I.name},   {"kind", static_cast<int>(I.kind)},
1369       {"range", I.range}, {"selectionRange", I.selectionRange},
1370       {"uri", I.uri},     {"data", I.data},
1371   };
1372
1373   if (I.detail)
1374     Result["detail"] = I.detail;
1375   return std::move(Result);
1376 }
1377
1378 bool fromJSON(const llvm::json::Value &Params, TypeHierarchyItem &I,
1379               llvm::json::Path P) {
1380   llvm::json::ObjectMapper O(Params, P);
1381
1382   // Required fields.
1383   return O && O.map("name", I.name) && O.map("kind", I.kind) &&
1384          O.map("uri", I.uri) && O.map("range", I.range) &&
1385          O.map("selectionRange", I.selectionRange) &&
1386          mapOptOrNull(Params, "detail", I.detail, P) &&
1387          mapOptOrNull(Params, "deprecated", I.deprecated, P) &&
1388          mapOptOrNull(Params, "parents", I.parents, P) &&
1389          mapOptOrNull(Params, "children", I.children, P) &&
1390          mapOptOrNull(Params, "data", I.data, P);
1391 }
1392
1393 bool fromJSON(const llvm::json::Value &Params,
1394               ResolveTypeHierarchyItemParams &R, llvm::json::Path P) {
1395   llvm::json::ObjectMapper O(Params, P);
1396   return O && O.map("item", R.item) &&
1397          mapOptOrNull(Params, "resolve", R.resolve, P) &&
1398          mapOptOrNull(Params, "direction", R.direction, P);
1399 }
1400
1401 bool fromJSON(const llvm::json::Value &Params, ReferenceContext &R,
1402               llvm::json::Path P) {
1403   llvm::json::ObjectMapper O(Params, P);
1404   return O && O.mapOptional("includeDeclaration", R.includeDeclaration);
1405 }
1406
1407 bool fromJSON(const llvm::json::Value &Params, ReferenceParams &R,
1408               llvm::json::Path P) {
1409   TextDocumentPositionParams &Base = R;
1410   llvm::json::ObjectMapper O(Params, P);
1411   return fromJSON(Params, Base, P) && O && O.mapOptional("context", R.context);
1412 }
1413
1414 llvm::json::Value toJSON(SymbolTag Tag) {
1415   return llvm::json::Value(static_cast<int>(Tag));
1416 }
1417
1418 llvm::json::Value toJSON(const CallHierarchyItem &I) {
1419   llvm::json::Object Result{{"name", I.name},
1420                             {"kind", static_cast<int>(I.kind)},
1421                             {"range", I.range},
1422                             {"selectionRange", I.selectionRange},
1423                             {"uri", I.uri}};
1424   if (!I.tags.empty())
1425     Result["tags"] = I.tags;
1426   if (!I.detail.empty())
1427     Result["detail"] = I.detail;
1428   if (!I.data.empty())
1429     Result["data"] = I.data;
1430   return std::move(Result);
1431 }
1432
1433 bool fromJSON(const llvm::json::Value &Params, CallHierarchyItem &I,
1434               llvm::json::Path P) {
1435   llvm::json::ObjectMapper O(Params, P);
1436
1437   // Populate the required fields only. We don't care about the
1438   // optional fields `Tags` and `Detail` for the purpose of
1439   // client --> server communication.
1440   return O && O.map("name", I.name) && O.map("kind", I.kind) &&
1441          O.map("uri", I.uri) && O.map("range", I.range) &&
1442          O.map("selectionRange", I.selectionRange) &&
1443          mapOptOrNull(Params, "data", I.data, P);
1444 }
1445
1446 bool fromJSON(const llvm::json::Value &Params,
1447               CallHierarchyIncomingCallsParams &C, llvm::json::Path P) {
1448   llvm::json::ObjectMapper O(Params, P);
1449   return O.map("item", C.item);
1450 }
1451
1452 llvm::json::Value toJSON(const CallHierarchyIncomingCall &C) {
1453   return llvm::json::Object{{"from", C.from}, {"fromRanges", C.fromRanges}};
1454 }
1455
1456 bool fromJSON(const llvm::json::Value &Params,
1457               CallHierarchyOutgoingCallsParams &C, llvm::json::Path P) {
1458   llvm::json::ObjectMapper O(Params, P);
1459   return O.map("item", C.item);
1460 }
1461
1462 llvm::json::Value toJSON(const CallHierarchyOutgoingCall &C) {
1463   return llvm::json::Object{{"to", C.to}, {"fromRanges", C.fromRanges}};
1464 }
1465
1466 bool fromJSON(const llvm::json::Value &Params, InlayHintsParams &R,
1467               llvm::json::Path P) {
1468   llvm::json::ObjectMapper O(Params, P);
1469   return O && O.map("textDocument", R.textDocument) && O.map("range", R.range);
1470 }
1471
1472 llvm::json::Value toJSON(const InlayHintKind &Kind) {
1473   switch (Kind) {
1474   case InlayHintKind::Type:
1475     return 1;
1476   case InlayHintKind::Parameter:
1477     return 2;
1478   case InlayHintKind::Designator:
1479   case InlayHintKind::BlockEnd:
1480     // This is an extension, don't serialize.
1481     return nullptr;
1482   }
1483   llvm_unreachable("Unknown clang.clangd.InlayHintKind");
1484 }
1485
1486 llvm::json::Value toJSON(const InlayHint &H) {
1487   llvm::json::Object Result{{"position", H.position},
1488                             {"label", H.label},
1489                             {"paddingLeft", H.paddingLeft},
1490                             {"paddingRight", H.paddingRight}};
1491   auto K = toJSON(H.kind);
1492   if (!K.getAsNull())
1493     Result["kind"] = std::move(K);
1494   return std::move(Result);
1495 }
1496 bool operator==(const InlayHint &A, const InlayHint &B) {
1497   return std::tie(A.position, A.range, A.kind, A.label) ==
1498          std::tie(B.position, B.range, B.kind, B.label);
1499 }
1500 bool operator<(const InlayHint &A, const InlayHint &B) {
1501   return std::tie(A.position, A.range, A.kind, A.label) <
1502          std::tie(B.position, B.range, B.kind, B.label);
1503 }
1504 std::string InlayHint::joinLabels() const {
1505   return llvm::join(llvm::map_range(label, [](auto &L) { return L.value; }),
1506                     "");
1507 }
1508
1509 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, InlayHintKind Kind) {
1510   auto ToString = [](InlayHintKind K) {
1511     switch (K) {
1512     case InlayHintKind::Parameter:
1513       return "parameter";
1514     case InlayHintKind::Type:
1515       return "type";
1516     case InlayHintKind::Designator:
1517       return "designator";
1518     case InlayHintKind::BlockEnd:
1519       return "block-end";
1520     }
1521     llvm_unreachable("Unknown clang.clangd.InlayHintKind");
1522   };
1523   return OS << ToString(Kind);
1524 }
1525
1526 llvm::json::Value toJSON(const InlayHintLabelPart &L) {
1527   llvm::json::Object Result{{"value", L.value}};
1528   if (L.tooltip)
1529     Result["tooltip"] = *L.tooltip;
1530   if (L.location)
1531     Result["location"] = *L.location;
1532   if (L.command)
1533     Result["command"] = *L.command;
1534   return Result;
1535 }
1536
1537 bool operator==(const InlayHintLabelPart &LHS, const InlayHintLabelPart &RHS) {
1538   return std::tie(LHS.value, LHS.location) == std::tie(RHS.value, RHS.location);
1539 }
1540
1541 bool operator<(const InlayHintLabelPart &LHS, const InlayHintLabelPart &RHS) {
1542   return std::tie(LHS.value, LHS.location) < std::tie(RHS.value, RHS.location);
1543 }
1544
1545 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
1546                               const InlayHintLabelPart &L) {
1547   OS << L.value;
1548   if (L.location)
1549     OS << " (" << L.location << ")";
1550   return OS;
1551 }
1552
1553 static const char *toString(OffsetEncoding OE) {
1554   switch (OE) {
1555   case OffsetEncoding::UTF8:
1556     return "utf-8";
1557   case OffsetEncoding::UTF16:
1558     return "utf-16";
1559   case OffsetEncoding::UTF32:
1560     return "utf-32";
1561   case OffsetEncoding::UnsupportedEncoding:
1562     return "unknown";
1563   }
1564   llvm_unreachable("Unknown clang.clangd.OffsetEncoding");
1565 }
1566 llvm::json::Value toJSON(const OffsetEncoding &OE) { return toString(OE); }
1567 bool fromJSON(const llvm::json::Value &V, OffsetEncoding &OE,
1568               llvm::json::Path P) {
1569   auto Str = V.getAsString();
1570   if (!Str)
1571     return false;
1572   OE = llvm::StringSwitch<OffsetEncoding>(*Str)
1573            .Case("utf-8", OffsetEncoding::UTF8)
1574            .Case("utf-16", OffsetEncoding::UTF16)
1575            .Case("utf-32", OffsetEncoding::UTF32)
1576            .Default(OffsetEncoding::UnsupportedEncoding);
1577   return true;
1578 }
1579 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, OffsetEncoding Enc) {
1580   return OS << toString(Enc);
1581 }
1582
1583 bool fromJSON(const llvm::json::Value &Params, SelectionRangeParams &S,
1584               llvm::json::Path P) {
1585   llvm::json::ObjectMapper O(Params, P);
1586   return O && O.map("textDocument", S.textDocument) &&
1587          O.map("positions", S.positions);
1588 }
1589
1590 llvm::json::Value toJSON(const SelectionRange &Out) {
1591   if (Out.parent) {
1592     return llvm::json::Object{{"range", Out.range},
1593                               {"parent", toJSON(*Out.parent)}};
1594   }
1595   return llvm::json::Object{{"range", Out.range}};
1596 }
1597
1598 bool fromJSON(const llvm::json::Value &Params, DocumentLinkParams &R,
1599               llvm::json::Path P) {
1600   llvm::json::ObjectMapper O(Params, P);
1601   return O && O.map("textDocument", R.textDocument);
1602 }
1603
1604 llvm::json::Value toJSON(const DocumentLink &DocumentLink) {
1605   return llvm::json::Object{
1606       {"range", DocumentLink.range},
1607       {"target", DocumentLink.target},
1608   };
1609 }
1610
1611 bool fromJSON(const llvm::json::Value &Params, FoldingRangeParams &R,
1612               llvm::json::Path P) {
1613   llvm::json::ObjectMapper O(Params, P);
1614   return O && O.map("textDocument", R.textDocument);
1615 }
1616
1617 const llvm::StringLiteral FoldingRange::REGION_KIND = "region";
1618 const llvm::StringLiteral FoldingRange::COMMENT_KIND = "comment";
1619 const llvm::StringLiteral FoldingRange::IMPORT_KIND = "import";
1620
1621 llvm::json::Value toJSON(const FoldingRange &Range) {
1622   llvm::json::Object Result{
1623       {"startLine", Range.startLine},
1624       {"endLine", Range.endLine},
1625   };
1626   if (Range.startCharacter)
1627     Result["startCharacter"] = Range.startCharacter;
1628   if (Range.endCharacter)
1629     Result["endCharacter"] = Range.endCharacter;
1630   if (!Range.kind.empty())
1631     Result["kind"] = Range.kind;
1632   return Result;
1633 }
1634
1635 llvm::json::Value toJSON(const MemoryTree &MT) {
1636   llvm::json::Object Out;
1637   int64_t Total = MT.self();
1638   Out["_self"] = Total;
1639   for (const auto &Entry : MT.children()) {
1640     auto Child = toJSON(Entry.getSecond());
1641     Total += *Child.getAsObject()->getInteger("_total");
1642     Out[Entry.first] = std::move(Child);
1643   }
1644   Out["_total"] = Total;
1645   return Out;
1646 }
1647
1648 bool fromJSON(const llvm::json::Value &Params, ASTParams &R,
1649               llvm::json::Path P) {
1650   llvm::json::ObjectMapper O(Params, P);
1651   return O && O.map("textDocument", R.textDocument) && O.map("range", R.range);
1652 }
1653
1654 llvm::json::Value toJSON(const ASTNode &N) {
1655   llvm::json::Object Result{
1656       {"role", N.role},
1657       {"kind", N.kind},
1658   };
1659   if (!N.children.empty())
1660     Result["children"] = N.children;
1661   if (!N.detail.empty())
1662     Result["detail"] = N.detail;
1663   if (!N.arcana.empty())
1664     Result["arcana"] = N.arcana;
1665   if (N.range)
1666     Result["range"] = *N.range;
1667   return Result;
1668 }
1669
1670 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const ASTNode &Root) {
1671   std::function<void(const ASTNode &, unsigned)> Print = [&](const ASTNode &N,
1672                                                              unsigned Level) {
1673     OS.indent(2 * Level) << N.role << ": " << N.kind;
1674     if (!N.detail.empty())
1675       OS << " - " << N.detail;
1676     OS << "\n";
1677     for (const ASTNode &C : N.children)
1678       Print(C, Level + 1);
1679   };
1680   Print(Root, 0);
1681   return OS;
1682 }
1683
1684 bool fromJSON(const llvm::json::Value &E, SymbolID &S, llvm::json::Path P) {
1685   auto Str = E.getAsString();
1686   if (!Str) {
1687     P.report("expected a string");
1688     return false;
1689   }
1690   auto ID = SymbolID::fromStr(*Str);
1691   if (!ID) {
1692     elog("Malformed symbolid: {0}", ID.takeError());
1693     P.report("malformed symbolid");
1694     return false;
1695   }
1696   S = *ID;
1697   return true;
1698 }
1699 llvm::json::Value toJSON(const SymbolID &S) { return S.str(); }
1700
1701 } // namespace clangd
1702 } // namespace clang