clang-tools-extra/clangd/ClangdServer.cpp

   1 //===--- ClangdServer.cpp - Main clangd server code --------------*- C++-*-===//
   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 #include "ClangdServer.h"
  10 #include "CodeComplete.h"
  11 #include "Config.h"
  12 #include "Diagnostics.h"
  13 #include "DumpAST.h"
  14 #include "FindSymbols.h"
  15 #include "Format.h"
  16 #include "HeaderSourceSwitch.h"
  17 #include "InlayHints.h"
  18 #include "ParsedAST.h"
  19 #include "Preamble.h"
  20 #include "Protocol.h"
  21 #include "SemanticHighlighting.h"
  22 #include "SemanticSelection.h"
  23 #include "SourceCode.h"
  24 #include "TUScheduler.h"
  25 #include "XRefs.h"
  26 #include "clang-include-cleaner/Record.h"
  27 #include "index/FileIndex.h"
  28 #include "index/Merge.h"
  29 #include "index/StdLib.h"
  30 #include "refactor/Rename.h"
  31 #include "refactor/Tweak.h"
  32 #include "support/Cancellation.h"
  33 #include "support/Logger.h"
  34 #include "support/MemoryTree.h"
  35 #include "support/ThreadsafeFS.h"
  36 #include "support/Trace.h"
  37 #include "clang/Basic/Stack.h"
  38 #include "clang/Format/Format.h"
  39 #include "clang/Lex/Preprocessor.h"
  40 #include "clang/Tooling/CompilationDatabase.h"
  41 #include "clang/Tooling/Core/Replacement.h"
  42 #include "llvm/ADT/ArrayRef.h"
  43 #include "llvm/ADT/STLExtras.h"
  44 #include "llvm/ADT/StringRef.h"
  45 #include "llvm/Support/Error.h"
  46 #include "llvm/Support/Path.h"
  47 #include "llvm/Support/raw_ostream.h"
  48 #include <algorithm>
  49 #include <chrono>
  50 #include <future>
  51 #include <memory>
  52 #include <mutex>
  53 #include <optional>
  54 #include <string>
  55 #include <type_traits>
  56 #include <utility>
  57 #include <vector>
  58
  59 namespace clang {
  60 namespace clangd {
  61 namespace {
  62
  63 // Tracks number of times a tweak has been offered.
  64 static constexpr trace::Metric TweakAvailable(
  65     "tweak_available", trace::Metric::Counter, "tweak_id");
  66
  67 // Update the FileIndex with new ASTs and plumb the diagnostics responses.
  68 struct UpdateIndexCallbacks : public ParsingCallbacks {
  69   UpdateIndexCallbacks(FileIndex *FIndex,
  70                        ClangdServer::Callbacks *ServerCallbacks,
  71                        const ThreadsafeFS &TFS, AsyncTaskRunner *Tasks,
  72                        bool CollectInactiveRegions)
  73       : FIndex(FIndex), ServerCallbacks(ServerCallbacks), TFS(TFS),
  74         Stdlib{std::make_shared<StdLibSet>()}, Tasks(Tasks),
  75         CollectInactiveRegions(CollectInactiveRegions) {}
  76
  77   void onPreambleAST(
  78       PathRef Path, llvm::StringRef Version, CapturedASTCtx ASTCtx,
  79       std::shared_ptr<const include_cleaner::PragmaIncludes> PI) override {
  80
  81     if (!FIndex)
  82       return;
  83
  84     auto &PP = ASTCtx.getPreprocessor();
  85     auto &CI = ASTCtx.getCompilerInvocation();
  86     if (auto Loc = Stdlib->add(CI.getLangOpts(), PP.getHeaderSearchInfo()))
  87       indexStdlib(CI, std::move(*Loc));
  88
  89     // FIndex outlives the UpdateIndexCallbacks.
  90     auto Task = [FIndex(FIndex), Path(Path.str()), Version(Version.str()),
  91                  ASTCtx(std::move(ASTCtx)), PI(std::move(PI))]() mutable {
  92       trace::Span Tracer("PreambleIndexing");
  93       FIndex->updatePreamble(Path, Version, ASTCtx.getASTContext(),
  94                              ASTCtx.getPreprocessor(), *PI);
  95     };
  96
  97     if (Tasks) {
  98       Tasks->runAsync("Preamble indexing for:" + Path + Version,
  99                       std::move(Task));
 100     } else
 101       Task();
 102   }
 103
 104   void indexStdlib(const CompilerInvocation &CI, StdLibLocation Loc) {
 105     // This task is owned by Tasks, which outlives the TUScheduler and
 106     // therefore the UpdateIndexCallbacks.
 107     // We must be careful that the references we capture outlive TUScheduler.
 108     auto Task = [LO(CI.getLangOpts()), Loc(std::move(Loc)),
 109                  CI(std::make_unique<CompilerInvocation>(CI)),
 110                  // External values that outlive ClangdServer
 111                  TFS(&TFS),
 112                  // Index outlives TUScheduler (declared first)
 113                  FIndex(FIndex),
 114                  // shared_ptr extends lifetime
 115                  Stdlib(Stdlib)]() mutable {
 116       clang::noteBottomOfStack();
 117       IndexFileIn IF;
 118       IF.Symbols = indexStandardLibrary(std::move(CI), Loc, *TFS);
 119       if (Stdlib->isBest(LO))
 120         FIndex->updatePreamble(std::move(IF));
 121     };
 122     if (Tasks)
 123       // This doesn't have a semaphore to enforce -j, but it's rare.
 124       Tasks->runAsync("IndexStdlib", std::move(Task));
 125     else
 126       Task();
 127   }
 128
 129   void onMainAST(PathRef Path, ParsedAST &AST, PublishFn Publish) override {
 130     if (FIndex)
 131       FIndex->updateMain(Path, AST);
 132
 133     if (ServerCallbacks)
 134       Publish([&]() {
 135         ServerCallbacks->onDiagnosticsReady(Path, AST.version(),
 136                                             AST.getDiagnostics());
 137         if (CollectInactiveRegions) {
 138           ServerCallbacks->onInactiveRegionsReady(Path,
 139                                                   getInactiveRegions(AST));
 140         }
 141       });
 142   }
 143
 144   void onFailedAST(PathRef Path, llvm::StringRef Version,
 145                    std::vector<Diag> Diags, PublishFn Publish) override {
 146     if (ServerCallbacks)
 147       Publish(
 148           [&]() { ServerCallbacks->onDiagnosticsReady(Path, Version, Diags); });
 149   }
 150
 151   void onFileUpdated(PathRef File, const TUStatus &Status) override {
 152     if (ServerCallbacks)
 153       ServerCallbacks->onFileUpdated(File, Status);
 154   }
 155
 156   void onPreamblePublished(PathRef File) override {
 157     if (ServerCallbacks)
 158       ServerCallbacks->onSemanticsMaybeChanged(File);
 159   }
 160
 161 private:
 162   FileIndex *FIndex;
 163   ClangdServer::Callbacks *ServerCallbacks;
 164   const ThreadsafeFS &TFS;
 165   std::shared_ptr<StdLibSet> Stdlib;
 166   AsyncTaskRunner *Tasks;
 167   bool CollectInactiveRegions;
 168 };
 169
 170 class DraftStoreFS : public ThreadsafeFS {
 171 public:
 172   DraftStoreFS(const ThreadsafeFS &Base, const DraftStore &Drafts)
 173       : Base(Base), DirtyFiles(Drafts) {}
 174
 175 private:
 176   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> viewImpl() const override {
 177     auto OFS = llvm::makeIntrusiveRefCnt<llvm::vfs::OverlayFileSystem>(
 178         Base.view(std::nullopt));
 179     OFS->pushOverlay(DirtyFiles.asVFS());
 180     return OFS;
 181   }
 182
 183   const ThreadsafeFS &Base;
 184   const DraftStore &DirtyFiles;
 185 };
 186
 187 } // namespace
 188
 189 ClangdServer::Options ClangdServer::optsForTest() {
 190   ClangdServer::Options Opts;
 191   Opts.UpdateDebounce = DebouncePolicy::fixed(/*zero*/ {});
 192   Opts.StorePreamblesInMemory = true;
 193   Opts.AsyncThreadsCount = 4; // Consistent!
 194   return Opts;
 195 }
 196
 197 ClangdServer::Options::operator TUScheduler::Options() const {
 198   TUScheduler::Options Opts;
 199   Opts.AsyncThreadsCount = AsyncThreadsCount;
 200   Opts.RetentionPolicy = RetentionPolicy;
 201   Opts.StorePreamblesInMemory = StorePreamblesInMemory;
 202   Opts.UpdateDebounce = UpdateDebounce;
 203   Opts.ContextProvider = ContextProvider;
 204   Opts.PreambleThrottler = PreambleThrottler;
 205   return Opts;
 206 }
 207
 208 ClangdServer::ClangdServer(const GlobalCompilationDatabase &CDB,
 209                            const ThreadsafeFS &TFS, const Options &Opts,
 210                            Callbacks *Callbacks)
 211     : FeatureModules(Opts.FeatureModules), CDB(CDB), TFS(TFS),
 212       DynamicIdx(Opts.BuildDynamicSymbolIndex ? new FileIndex() : nullptr),
 213       ClangTidyProvider(Opts.ClangTidyProvider),
 214       UseDirtyHeaders(Opts.UseDirtyHeaders),
 215       LineFoldingOnly(Opts.LineFoldingOnly),
 216       PreambleParseForwardingFunctions(Opts.PreambleParseForwardingFunctions),
 217       ImportInsertions(Opts.ImportInsertions),
 218       PublishInactiveRegions(Opts.PublishInactiveRegions),
 219       WorkspaceRoot(Opts.WorkspaceRoot),
 220       Transient(Opts.ImplicitCancellation ? TUScheduler::InvalidateOnUpdate
 221                                           : TUScheduler::NoInvalidation),
 222       DirtyFS(std::make_unique<DraftStoreFS>(TFS, DraftMgr)) {
 223   if (Opts.AsyncThreadsCount != 0)
 224     IndexTasks.emplace();
 225   // Pass a callback into `WorkScheduler` to extract symbols from a newly
 226   // parsed file and rebuild the file index synchronously each time an AST
 227   // is parsed.
 228   WorkScheduler.emplace(CDB, TUScheduler::Options(Opts),
 229                         std::make_unique<UpdateIndexCallbacks>(
 230                             DynamicIdx.get(), Callbacks, TFS,
 231                             IndexTasks ? &*IndexTasks : nullptr,
 232                             PublishInactiveRegions));
 233   // Adds an index to the stack, at higher priority than existing indexes.
 234   auto AddIndex = [&](SymbolIndex *Idx) {
 235     if (this->Index != nullptr) {
 236       MergedIdx.push_back(std::make_unique<MergedIndex>(Idx, this->Index));
 237       this->Index = MergedIdx.back().get();
 238     } else {
 239       this->Index = Idx;
 240     }
 241   };
 242   if (Opts.StaticIndex)
 243     AddIndex(Opts.StaticIndex);
 244   if (Opts.BackgroundIndex) {
 245     BackgroundIndex::Options BGOpts;
 246     BGOpts.ThreadPoolSize = std::max(Opts.AsyncThreadsCount, 1u);
 247     BGOpts.OnProgress = [Callbacks](BackgroundQueue::Stats S) {
 248       if (Callbacks)
 249         Callbacks->onBackgroundIndexProgress(S);
 250     };
 251     BGOpts.ContextProvider = Opts.ContextProvider;
 252     BackgroundIdx = std::make_unique<BackgroundIndex>(
 253         TFS, CDB,
 254         BackgroundIndexStorage::createDiskBackedStorageFactory(
 255             [&CDB](llvm::StringRef File) { return CDB.getProjectInfo(File); }),
 256         std::move(BGOpts));
 257     AddIndex(BackgroundIdx.get());
 258   }
 259   if (DynamicIdx)
 260     AddIndex(DynamicIdx.get());
 261
 262   if (Opts.FeatureModules) {
 263     FeatureModule::Facilities F{
 264         *this->WorkScheduler,
 265         this->Index,
 266         this->TFS,
 267     };
 268     for (auto &Mod : *Opts.FeatureModules)
 269       Mod.initialize(F);
 270   }
 271 }
 272
 273 ClangdServer::~ClangdServer() {
 274   // Destroying TUScheduler first shuts down request threads that might
 275   // otherwise access members concurrently.
 276   // (Nobody can be using TUScheduler because we're on the main thread).
 277   WorkScheduler.reset();
 278   // Now requests have stopped, we can shut down feature modules.
 279   if (FeatureModules) {
 280     for (auto &Mod : *FeatureModules)
 281       Mod.stop();
 282     for (auto &Mod : *FeatureModules)
 283       Mod.blockUntilIdle(Deadline::infinity());
 284   }
 285 }
 286
 287 void ClangdServer::addDocument(PathRef File, llvm::StringRef Contents,
 288                                llvm::StringRef Version,
 289                                WantDiagnostics WantDiags, bool ForceRebuild) {
 290   std::string ActualVersion = DraftMgr.addDraft(File, Version, Contents);
 291   ParseOptions Opts;
 292   Opts.PreambleParseForwardingFunctions = PreambleParseForwardingFunctions;
 293   Opts.ImportInsertions = ImportInsertions;
 294
 295   // Compile command is set asynchronously during update, as it can be slow.
 296   ParseInputs Inputs;
 297   Inputs.TFS = &getHeaderFS();
 298   Inputs.Contents = std::string(Contents);
 299   Inputs.Version = std::move(ActualVersion);
 300   Inputs.ForceRebuild = ForceRebuild;
 301   Inputs.Opts = std::move(Opts);
 302   Inputs.Index = Index;
 303   Inputs.ClangTidyProvider = ClangTidyProvider;
 304   Inputs.FeatureModules = FeatureModules;
 305   bool NewFile = WorkScheduler->update(File, Inputs, WantDiags);
 306   // If we loaded Foo.h, we want to make sure Foo.cpp is indexed.
 307   if (NewFile && BackgroundIdx)
 308     BackgroundIdx->boostRelated(File);
 309 }
 310
 311 void ClangdServer::reparseOpenFilesIfNeeded(
 312     llvm::function_ref<bool(llvm::StringRef File)> Filter) {
 313   // Reparse only opened files that were modified.
 314   for (const Path &FilePath : DraftMgr.getActiveFiles())
 315     if (Filter(FilePath))
 316       if (auto Draft = DraftMgr.getDraft(FilePath)) // else disappeared in race?
 317         addDocument(FilePath, *Draft->Contents, Draft->Version,
 318                     WantDiagnostics::Auto);
 319 }
 320
 321 std::shared_ptr<const std::string> ClangdServer::getDraft(PathRef File) const {
 322   auto Draft = DraftMgr.getDraft(File);
 323   if (!Draft)
 324     return nullptr;
 325   return std::move(Draft->Contents);
 326 }
 327
 328 std::function<Context(PathRef)>
 329 ClangdServer::createConfiguredContextProvider(const config::Provider *Provider,
 330                                               Callbacks *Publish) {
 331   if (!Provider)
 332     return [](llvm::StringRef) { return Context::current().clone(); };
 333
 334   struct Impl {
 335     const config::Provider *Provider;
 336     ClangdServer::Callbacks *Publish;
 337     std::mutex PublishMu;
 338
 339     Impl(const config::Provider *Provider, ClangdServer::Callbacks *Publish)
 340         : Provider(Provider), Publish(Publish) {}
 341
 342     Context operator()(llvm::StringRef File) {
 343       config::Params Params;
 344       // Don't reread config files excessively often.
 345       // FIXME: when we see a config file change event, use the event timestamp?
 346       Params.FreshTime =
 347           std::chrono::steady_clock::now() - std::chrono::seconds(5);
 348       llvm::SmallString<256> PosixPath;
 349       if (!File.empty()) {
 350         assert(llvm::sys::path::is_absolute(File));
 351         llvm::sys::path::native(File, PosixPath, llvm::sys::path::Style::posix);
 352         Params.Path = PosixPath.str();
 353       }
 354
 355       llvm::StringMap<std::vector<Diag>> ReportableDiagnostics;
 356       Config C = Provider->getConfig(Params, [&](const llvm::SMDiagnostic &D) {
 357         // Create the map entry even for note diagnostics we don't report.
 358         // This means that when the file is parsed with no warnings, we
 359         // publish an empty set of diagnostics, clearing any the client has.
 360         handleDiagnostic(D, !Publish || D.getFilename().empty()
 361                                 ? nullptr
 362                                 : &ReportableDiagnostics[D.getFilename()]);
 363       });
 364       // Blindly publish diagnostics for the (unopened) parsed config files.
 365       // We must avoid reporting diagnostics for *the same file* concurrently.
 366       // Source diags are published elsewhere, but those are different files.
 367       if (!ReportableDiagnostics.empty()) {
 368         std::lock_guard<std::mutex> Lock(PublishMu);
 369         for (auto &Entry : ReportableDiagnostics)
 370           Publish->onDiagnosticsReady(Entry.first(), /*Version=*/"",
 371                                       Entry.second);
 372       }
 373       return Context::current().derive(Config::Key, std::move(C));
 374     }
 375
 376     void handleDiagnostic(const llvm::SMDiagnostic &D,
 377                           std::vector<Diag> *ClientDiagnostics) {
 378       switch (D.getKind()) {
 379       case llvm::SourceMgr::DK_Error:
 380         elog("config error at {0}:{1}:{2}: {3}", D.getFilename(), D.getLineNo(),
 381              D.getColumnNo(), D.getMessage());
 382         break;
 383       case llvm::SourceMgr::DK_Warning:
 384         log("config warning at {0}:{1}:{2}: {3}", D.getFilename(),
 385             D.getLineNo(), D.getColumnNo(), D.getMessage());
 386         break;
 387       case llvm::SourceMgr::DK_Note:
 388       case llvm::SourceMgr::DK_Remark:
 389         vlog("config note at {0}:{1}:{2}: {3}", D.getFilename(), D.getLineNo(),
 390              D.getColumnNo(), D.getMessage());
 391         ClientDiagnostics = nullptr; // Don't emit notes as LSP diagnostics.
 392         break;
 393       }
 394       if (ClientDiagnostics)
 395         ClientDiagnostics->push_back(toDiag(D, Diag::ClangdConfig));
 396     }
 397   };
 398
 399   // Copyable wrapper.
 400   return [I(std::make_shared<Impl>(Provider, Publish))](llvm::StringRef Path) {
 401     return (*I)(Path);
 402   };
 403 }
 404
 405 void ClangdServer::removeDocument(PathRef File) {
 406   DraftMgr.removeDraft(File);
 407   WorkScheduler->remove(File);
 408 }
 409
 410 void ClangdServer::codeComplete(PathRef File, Position Pos,
 411                                 const clangd::CodeCompleteOptions &Opts,
 412                                 Callback<CodeCompleteResult> CB) {
 413   // Copy completion options for passing them to async task handler.
 414   auto CodeCompleteOpts = Opts;
 415   if (!CodeCompleteOpts.Index) // Respect overridden index.
 416     CodeCompleteOpts.Index = Index;
 417
 418   auto Task = [Pos, CodeCompleteOpts, File = File.str(), CB = std::move(CB),
 419                this](llvm::Expected<InputsAndPreamble> IP) mutable {
 420     if (!IP)
 421       return CB(IP.takeError());
 422     if (auto Reason = isCancelled())
 423       return CB(llvm::make_error<CancelledError>(Reason));
 424
 425     std::optional<SpeculativeFuzzyFind> SpecFuzzyFind;
 426     if (!IP->Preamble) {
 427       // No speculation in Fallback mode, as it's supposed to be much faster
 428       // without compiling.
 429       vlog("Build for file {0} is not ready. Enter fallback mode.", File);
 430     } else if (CodeCompleteOpts.Index) {
 431       SpecFuzzyFind.emplace();
 432       {
 433         std::lock_guard<std::mutex> Lock(CachedCompletionFuzzyFindRequestMutex);
 434         SpecFuzzyFind->CachedReq = CachedCompletionFuzzyFindRequestByFile[File];
 435       }
 436     }
 437     ParseInputs ParseInput{IP->Command, &getHeaderFS(), IP->Contents.str()};
 438     // FIXME: Add traling new line if there is none at eof, workaround a crash,
 439     // see https://github.com/clangd/clangd/issues/332
 440     if (!IP->Contents.endswith("\n"))
 441       ParseInput.Contents.append("\n");
 442     ParseInput.Index = Index;
 443
 444     CodeCompleteOpts.MainFileSignals = IP->Signals;
 445     CodeCompleteOpts.AllScopes = Config::current().Completion.AllScopes;
 446     // FIXME(ibiryukov): even if Preamble is non-null, we may want to check
 447     // both the old and the new version in case only one of them matches.
 448     CodeCompleteResult Result = clangd::codeComplete(
 449         File, Pos, IP->Preamble, ParseInput, CodeCompleteOpts,
 450         SpecFuzzyFind ? &*SpecFuzzyFind : nullptr);
 451     {
 452       clang::clangd::trace::Span Tracer("Completion results callback");
 453       CB(std::move(Result));
 454     }
 455     if (SpecFuzzyFind && SpecFuzzyFind->NewReq) {
 456       std::lock_guard<std::mutex> Lock(CachedCompletionFuzzyFindRequestMutex);
 457       CachedCompletionFuzzyFindRequestByFile[File] = *SpecFuzzyFind->NewReq;
 458     }
 459     // SpecFuzzyFind is only destroyed after speculative fuzzy find finishes.
 460     // We don't want `codeComplete` to wait for the async call if it doesn't use
 461     // the result (e.g. non-index completion, speculation fails), so that `CB`
 462     // is called as soon as results are available.
 463   };
 464
 465   // We use a potentially-stale preamble because latency is critical here.
 466   WorkScheduler->runWithPreamble(
 467       "CodeComplete", File,
 468       (Opts.RunParser == CodeCompleteOptions::AlwaysParse)
 469           ? TUScheduler::Stale
 470           : TUScheduler::StaleOrAbsent,
 471       std::move(Task));
 472 }
 473
 474 void ClangdServer::signatureHelp(PathRef File, Position Pos,
 475                                  MarkupKind DocumentationFormat,
 476                                  Callback<SignatureHelp> CB) {
 477
 478   auto Action = [Pos, File = File.str(), CB = std::move(CB),
 479                  DocumentationFormat,
 480                  this](llvm::Expected<InputsAndPreamble> IP) mutable {
 481     if (!IP)
 482       return CB(IP.takeError());
 483
 484     const auto *PreambleData = IP->Preamble;
 485     if (!PreambleData)
 486       return CB(error("Failed to parse includes"));
 487
 488     ParseInputs ParseInput{IP->Command, &getHeaderFS(), IP->Contents.str()};
 489     // FIXME: Add traling new line if there is none at eof, workaround a crash,
 490     // see https://github.com/clangd/clangd/issues/332
 491     if (!IP->Contents.endswith("\n"))
 492       ParseInput.Contents.append("\n");
 493     ParseInput.Index = Index;
 494     CB(clangd::signatureHelp(File, Pos, *PreambleData, ParseInput,
 495                              DocumentationFormat));
 496   };
 497
 498   // Unlike code completion, we wait for a preamble here.
 499   WorkScheduler->runWithPreamble("SignatureHelp", File, TUScheduler::Stale,
 500                                  std::move(Action));
 501 }
 502
 503 void ClangdServer::formatFile(PathRef File, std::optional<Range> Rng,
 504                               Callback<tooling::Replacements> CB) {
 505   auto Code = getDraft(File);
 506   if (!Code)
 507     return CB(llvm::make_error<LSPError>("trying to format non-added document",
 508                                          ErrorCode::InvalidParams));
 509   tooling::Range RequestedRange;
 510   if (Rng) {
 511     llvm::Expected<size_t> Begin = positionToOffset(*Code, Rng->start);
 512     if (!Begin)
 513       return CB(Begin.takeError());
 514     llvm::Expected<size_t> End = positionToOffset(*Code, Rng->end);
 515     if (!End)
 516       return CB(End.takeError());
 517     RequestedRange = tooling::Range(*Begin, *End - *Begin);
 518   } else {
 519     RequestedRange = tooling::Range(0, Code->size());
 520   }
 521
 522   // Call clang-format.
 523   auto Action = [File = File.str(), Code = std::move(*Code),
 524                  Ranges = std::vector<tooling::Range>{RequestedRange},
 525                  CB = std::move(CB), this]() mutable {
 526     format::FormatStyle Style = getFormatStyleForFile(File, Code, TFS);
 527     tooling::Replacements IncludeReplaces =
 528         format::sortIncludes(Style, Code, Ranges, File);
 529     auto Changed = tooling::applyAllReplacements(Code, IncludeReplaces);
 530     if (!Changed)
 531       return CB(Changed.takeError());
 532
 533     CB(IncludeReplaces.merge(format::reformat(
 534         Style, *Changed,
 535         tooling::calculateRangesAfterReplacements(IncludeReplaces, Ranges),
 536         File)));
 537   };
 538   WorkScheduler->runQuick("Format", File, std::move(Action));
 539 }
 540
 541 void ClangdServer::formatOnType(PathRef File, Position Pos,
 542                                 StringRef TriggerText,
 543                                 Callback<std::vector<TextEdit>> CB) {
 544   auto Code = getDraft(File);
 545   if (!Code)
 546     return CB(llvm::make_error<LSPError>("trying to format non-added document",
 547                                          ErrorCode::InvalidParams));
 548   llvm::Expected<size_t> CursorPos = positionToOffset(*Code, Pos);
 549   if (!CursorPos)
 550     return CB(CursorPos.takeError());
 551   auto Action = [File = File.str(), Code = std::move(*Code),
 552                  TriggerText = TriggerText.str(), CursorPos = *CursorPos,
 553                  CB = std::move(CB), this]() mutable {
 554     auto Style = format::getStyle(format::DefaultFormatStyle, File,
 555                                   format::DefaultFallbackStyle, Code,
 556                                   TFS.view(/*CWD=*/std::nullopt).get());
 557     if (!Style)
 558       return CB(Style.takeError());
 559
 560     std::vector<TextEdit> Result;
 561     for (const tooling::Replacement &R :
 562          formatIncremental(Code, CursorPos, TriggerText, *Style))
 563       Result.push_back(replacementToEdit(Code, R));
 564     return CB(Result);
 565   };
 566   WorkScheduler->runQuick("FormatOnType", File, std::move(Action));
 567 }
 568
 569 void ClangdServer::prepareRename(PathRef File, Position Pos,
 570                                  std::optional<std::string> NewName,
 571                                  const RenameOptions &RenameOpts,
 572                                  Callback<RenameResult> CB) {
 573   auto Action = [Pos, File = File.str(), CB = std::move(CB),
 574                  NewName = std::move(NewName),
 575                  RenameOpts](llvm::Expected<InputsAndAST> InpAST) mutable {
 576     if (!InpAST)
 577       return CB(InpAST.takeError());
 578     // prepareRename is latency-sensitive: we don't query the index, as we
 579     // only need main-file references
 580     auto Results =
 581         clangd::rename({Pos, NewName.value_or("__clangd_rename_placeholder"),
 582                         InpAST->AST, File, /*FS=*/nullptr,
 583                         /*Index=*/nullptr, RenameOpts});
 584     if (!Results) {
 585       // LSP says to return null on failure, but that will result in a generic
 586       // failure message. If we send an LSP error response, clients can surface
 587       // the message to users (VSCode does).
 588       return CB(Results.takeError());
 589     }
 590     return CB(*Results);
 591   };
 592   WorkScheduler->runWithAST("PrepareRename", File, std::move(Action));
 593 }
 594
 595 void ClangdServer::rename(PathRef File, Position Pos, llvm::StringRef NewName,
 596                           const RenameOptions &Opts,
 597                           Callback<RenameResult> CB) {
 598   auto Action = [File = File.str(), NewName = NewName.str(), Pos, Opts,
 599                  CB = std::move(CB),
 600                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 601     // Tracks number of files edited per invocation.
 602     static constexpr trace::Metric RenameFiles("rename_files",
 603                                                trace::Metric::Distribution);
 604     if (!InpAST)
 605       return CB(InpAST.takeError());
 606     auto R = clangd::rename({Pos, NewName, InpAST->AST, File,
 607                              DirtyFS->view(std::nullopt), Index, Opts});
 608     if (!R)
 609       return CB(R.takeError());
 610
 611     if (Opts.WantFormat) {
 612       auto Style = getFormatStyleForFile(File, InpAST->Inputs.Contents,
 613                                          *InpAST->Inputs.TFS);
 614       llvm::Error Err = llvm::Error::success();
 615       for (auto &E : R->GlobalChanges)
 616         Err =
 617             llvm::joinErrors(reformatEdit(E.getValue(), Style), std::move(Err));
 618
 619       if (Err)
 620         return CB(std::move(Err));
 621     }
 622     RenameFiles.record(R->GlobalChanges.size());
 623     return CB(*R);
 624   };
 625   WorkScheduler->runWithAST("Rename", File, std::move(Action));
 626 }
 627
 628 // May generate several candidate selections, due to SelectionTree ambiguity.
 629 // vector of pointers because GCC doesn't like non-copyable Selection.
 630 static llvm::Expected<std::vector<std::unique_ptr<Tweak::Selection>>>
 631 tweakSelection(const Range &Sel, const InputsAndAST &AST,
 632                llvm::vfs::FileSystem *FS) {
 633   auto Begin = positionToOffset(AST.Inputs.Contents, Sel.start);
 634   if (!Begin)
 635     return Begin.takeError();
 636   auto End = positionToOffset(AST.Inputs.Contents, Sel.end);
 637   if (!End)
 638     return End.takeError();
 639   std::vector<std::unique_ptr<Tweak::Selection>> Result;
 640   SelectionTree::createEach(
 641       AST.AST.getASTContext(), AST.AST.getTokens(), *Begin, *End,
 642       [&](SelectionTree T) {
 643         Result.push_back(std::make_unique<Tweak::Selection>(
 644             AST.Inputs.Index, AST.AST, *Begin, *End, std::move(T), FS));
 645         return false;
 646       });
 647   assert(!Result.empty() && "Expected at least one SelectionTree");
 648   return std::move(Result);
 649 }
 650
 651 void ClangdServer::codeAction(const CodeActionInputs &Params,
 652                               Callback<CodeActionResult> CB) {
 653   auto Action = [Params, CB = std::move(CB),
 654                  FeatureModules(this->FeatureModules)](
 655                     Expected<InputsAndAST> InpAST) mutable {
 656     if (!InpAST)
 657       return CB(InpAST.takeError());
 658     auto KindAllowed =
 659         [Only(Params.RequestedActionKinds)](llvm::StringRef Kind) {
 660           if (Only.empty())
 661             return true;
 662           return llvm::any_of(Only, [&](llvm::StringRef Base) {
 663             return Kind.consume_front(Base) &&
 664                    (Kind.empty() || Kind.startswith("."));
 665           });
 666         };
 667
 668     CodeActionResult Result;
 669     Result.Version = InpAST->AST.version().str();
 670     if (KindAllowed(CodeAction::QUICKFIX_KIND)) {
 671       auto FindMatchedFixes =
 672           [&InpAST](const DiagRef &DR) -> llvm::ArrayRef<Fix> {
 673         for (const auto &Diag : InpAST->AST.getDiagnostics())
 674           if (Diag.Range == DR.Range && Diag.Message == DR.Message)
 675             return Diag.Fixes;
 676         return {};
 677       };
 678       for (const auto &Diag : Params.Diagnostics)
 679         for (const auto &Fix : FindMatchedFixes(Diag))
 680           Result.QuickFixes.push_back({Diag, Fix});
 681     }
 682
 683     // Collect Tweaks
 684     auto Selections = tweakSelection(Params.Selection, *InpAST, /*FS=*/nullptr);
 685     if (!Selections)
 686       return CB(Selections.takeError());
 687     // Don't allow a tweak to fire more than once across ambiguous selections.
 688     llvm::DenseSet<llvm::StringRef> PreparedTweaks;
 689     auto DeduplicatingFilter = [&](const Tweak &T) {
 690       return KindAllowed(T.kind()) && Params.TweakFilter(T) &&
 691              !PreparedTweaks.count(T.id());
 692     };
 693     for (const auto &Sel : *Selections) {
 694       for (auto &T : prepareTweaks(*Sel, DeduplicatingFilter, FeatureModules)) {
 695         Result.TweakRefs.push_back(TweakRef{T->id(), T->title(), T->kind()});
 696         PreparedTweaks.insert(T->id());
 697         TweakAvailable.record(1, T->id());
 698       }
 699     }
 700     CB(std::move(Result));
 701   };
 702
 703   WorkScheduler->runWithAST("codeAction", Params.File, std::move(Action),
 704                             Transient);
 705 }
 706
 707 void ClangdServer::applyTweak(PathRef File, Range Sel, StringRef TweakID,
 708                               Callback<Tweak::Effect> CB) {
 709   // Tracks number of times a tweak has been attempted.
 710   static constexpr trace::Metric TweakAttempt(
 711       "tweak_attempt", trace::Metric::Counter, "tweak_id");
 712   // Tracks number of times a tweak has failed to produce edits.
 713   static constexpr trace::Metric TweakFailed(
 714       "tweak_failed", trace::Metric::Counter, "tweak_id");
 715   TweakAttempt.record(1, TweakID);
 716   auto Action = [File = File.str(), Sel, TweakID = TweakID.str(),
 717                  CB = std::move(CB),
 718                  this](Expected<InputsAndAST> InpAST) mutable {
 719     if (!InpAST)
 720       return CB(InpAST.takeError());
 721     auto FS = DirtyFS->view(std::nullopt);
 722     auto Selections = tweakSelection(Sel, *InpAST, FS.get());
 723     if (!Selections)
 724       return CB(Selections.takeError());
 725     std::optional<llvm::Expected<Tweak::Effect>> Effect;
 726     // Try each selection, take the first one that prepare()s.
 727     // If they all fail, Effect will hold get the last error.
 728     for (const auto &Selection : *Selections) {
 729       auto T = prepareTweak(TweakID, *Selection, FeatureModules);
 730       if (T) {
 731         Effect = (*T)->apply(*Selection);
 732         break;
 733       }
 734       Effect = T.takeError();
 735     }
 736     assert(Effect && "Expected at least one selection");
 737     if (*Effect && (*Effect)->FormatEdits) {
 738       // Format tweaks that require it centrally here.
 739       for (auto &It : (*Effect)->ApplyEdits) {
 740         Edit &E = It.second;
 741         format::FormatStyle Style =
 742             getFormatStyleForFile(File, E.InitialCode, TFS);
 743         if (llvm::Error Err = reformatEdit(E, Style))
 744           elog("Failed to format {0}: {1}", It.first(), std::move(Err));
 745       }
 746     } else {
 747       TweakFailed.record(1, TweakID);
 748     }
 749     return CB(std::move(*Effect));
 750   };
 751   WorkScheduler->runWithAST("ApplyTweak", File, std::move(Action));
 752 }
 753
 754 void ClangdServer::locateSymbolAt(PathRef File, Position Pos,
 755                                   Callback<std::vector<LocatedSymbol>> CB) {
 756   auto Action = [Pos, CB = std::move(CB),
 757                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 758     if (!InpAST)
 759       return CB(InpAST.takeError());
 760     CB(clangd::locateSymbolAt(InpAST->AST, Pos, Index));
 761   };
 762
 763   WorkScheduler->runWithAST("Definitions", File, std::move(Action));
 764 }
 765
 766 void ClangdServer::switchSourceHeader(
 767     PathRef Path, Callback<std::optional<clangd::Path>> CB) {
 768   // We want to return the result as fast as possible, strategy is:
 769   //  1) use the file-only heuristic, it requires some IO but it is much
 770   //     faster than building AST, but it only works when .h/.cc files are in
 771   //     the same directory.
 772   //  2) if 1) fails, we use the AST&Index approach, it is slower but supports
 773   //     different code layout.
 774   if (auto CorrespondingFile =
 775           getCorrespondingHeaderOrSource(Path, TFS.view(std::nullopt)))
 776     return CB(std::move(CorrespondingFile));
 777   auto Action = [Path = Path.str(), CB = std::move(CB),
 778                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 779     if (!InpAST)
 780       return CB(InpAST.takeError());
 781     CB(getCorrespondingHeaderOrSource(Path, InpAST->AST, Index));
 782   };
 783   WorkScheduler->runWithAST("SwitchHeaderSource", Path, std::move(Action));
 784 }
 785
 786 void ClangdServer::findDocumentHighlights(
 787     PathRef File, Position Pos, Callback<std::vector<DocumentHighlight>> CB) {
 788   auto Action =
 789       [Pos, CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
 790         if (!InpAST)
 791           return CB(InpAST.takeError());
 792         CB(clangd::findDocumentHighlights(InpAST->AST, Pos));
 793       };
 794
 795   WorkScheduler->runWithAST("Highlights", File, std::move(Action), Transient);
 796 }
 797
 798 void ClangdServer::findHover(PathRef File, Position Pos,
 799                              Callback<std::optional<HoverInfo>> CB) {
 800   auto Action = [File = File.str(), Pos, CB = std::move(CB),
 801                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 802     if (!InpAST)
 803       return CB(InpAST.takeError());
 804     format::FormatStyle Style = getFormatStyleForFile(
 805         File, InpAST->Inputs.Contents, *InpAST->Inputs.TFS);
 806     CB(clangd::getHover(InpAST->AST, Pos, std::move(Style), Index));
 807   };
 808
 809   WorkScheduler->runWithAST("Hover", File, std::move(Action), Transient);
 810 }
 811
 812 void ClangdServer::typeHierarchy(PathRef File, Position Pos, int Resolve,
 813                                  TypeHierarchyDirection Direction,
 814                                  Callback<std::vector<TypeHierarchyItem>> CB) {
 815   auto Action = [File = File.str(), Pos, Resolve, Direction, CB = std::move(CB),
 816                  this](Expected<InputsAndAST> InpAST) mutable {
 817     if (!InpAST)
 818       return CB(InpAST.takeError());
 819     CB(clangd::getTypeHierarchy(InpAST->AST, Pos, Resolve, Direction, Index,
 820                                 File));
 821   };
 822
 823   WorkScheduler->runWithAST("TypeHierarchy", File, std::move(Action));
 824 }
 825
 826 void ClangdServer::superTypes(
 827     const TypeHierarchyItem &Item,
 828     Callback<std::optional<std::vector<TypeHierarchyItem>>> CB) {
 829   WorkScheduler->run("typeHierarchy/superTypes", /*Path=*/"",
 830                      [=, CB = std::move(CB)]() mutable {
 831                        CB(clangd::superTypes(Item, Index));
 832                      });
 833 }
 834
 835 void ClangdServer::subTypes(const TypeHierarchyItem &Item,
 836                             Callback<std::vector<TypeHierarchyItem>> CB) {
 837   WorkScheduler->run(
 838       "typeHierarchy/subTypes", /*Path=*/"",
 839       [=, CB = std::move(CB)]() mutable { CB(clangd::subTypes(Item, Index)); });
 840 }
 841
 842 void ClangdServer::resolveTypeHierarchy(
 843     TypeHierarchyItem Item, int Resolve, TypeHierarchyDirection Direction,
 844     Callback<std::optional<TypeHierarchyItem>> CB) {
 845   WorkScheduler->run(
 846       "Resolve Type Hierarchy", "", [=, CB = std::move(CB)]() mutable {
 847         clangd::resolveTypeHierarchy(Item, Resolve, Direction, Index);
 848         CB(Item);
 849       });
 850 }
 851
 852 void ClangdServer::prepareCallHierarchy(
 853     PathRef File, Position Pos, Callback<std::vector<CallHierarchyItem>> CB) {
 854   auto Action = [File = File.str(), Pos,
 855                  CB = std::move(CB)](Expected<InputsAndAST> InpAST) mutable {
 856     if (!InpAST)
 857       return CB(InpAST.takeError());
 858     CB(clangd::prepareCallHierarchy(InpAST->AST, Pos, File));
 859   };
 860   WorkScheduler->runWithAST("CallHierarchy", File, std::move(Action));
 861 }
 862
 863 void ClangdServer::incomingCalls(
 864     const CallHierarchyItem &Item,
 865     Callback<std::vector<CallHierarchyIncomingCall>> CB) {
 866   WorkScheduler->run("Incoming Calls", "",
 867                      [CB = std::move(CB), Item, this]() mutable {
 868                        CB(clangd::incomingCalls(Item, Index));
 869                      });
 870 }
 871
 872 void ClangdServer::inlayHints(PathRef File, std::optional<Range> RestrictRange,
 873                               Callback<std::vector<InlayHint>> CB) {
 874   auto Action = [RestrictRange(std::move(RestrictRange)),
 875                  CB = std::move(CB)](Expected<InputsAndAST> InpAST) mutable {
 876     if (!InpAST)
 877       return CB(InpAST.takeError());
 878     CB(clangd::inlayHints(InpAST->AST, std::move(RestrictRange)));
 879   };
 880   WorkScheduler->runWithAST("InlayHints", File, std::move(Action), Transient);
 881 }
 882
 883 void ClangdServer::onFileEvent(const DidChangeWatchedFilesParams &Params) {
 884   // FIXME: Do nothing for now. This will be used for indexing and potentially
 885   // invalidating other caches.
 886 }
 887
 888 void ClangdServer::workspaceSymbols(
 889     llvm::StringRef Query, int Limit,
 890     Callback<std::vector<SymbolInformation>> CB) {
 891   WorkScheduler->run(
 892       "getWorkspaceSymbols", /*Path=*/"",
 893       [Query = Query.str(), Limit, CB = std::move(CB), this]() mutable {
 894         CB(clangd::getWorkspaceSymbols(Query, Limit, Index,
 895                                        WorkspaceRoot.value_or("")));
 896       });
 897 }
 898
 899 void ClangdServer::documentSymbols(llvm::StringRef File,
 900                                    Callback<std::vector<DocumentSymbol>> CB) {
 901   auto Action =
 902       [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
 903         if (!InpAST)
 904           return CB(InpAST.takeError());
 905         CB(clangd::getDocumentSymbols(InpAST->AST));
 906       };
 907   WorkScheduler->runWithAST("DocumentSymbols", File, std::move(Action),
 908                             Transient);
 909 }
 910
 911 void ClangdServer::foldingRanges(llvm::StringRef File,
 912                                  Callback<std::vector<FoldingRange>> CB) {
 913   auto Code = getDraft(File);
 914   if (!Code)
 915     return CB(llvm::make_error<LSPError>(
 916         "trying to compute folding ranges for non-added document",
 917         ErrorCode::InvalidParams));
 918   auto Action = [LineFoldingOnly = LineFoldingOnly, CB = std::move(CB),
 919                  Code = std::move(*Code)]() mutable {
 920     CB(clangd::getFoldingRanges(Code, LineFoldingOnly));
 921   };
 922   // We want to make sure folding ranges are always available for all the open
 923   // files, hence prefer runQuick to not wait for operations on other files.
 924   WorkScheduler->runQuick("FoldingRanges", File, std::move(Action));
 925 }
 926
 927 void ClangdServer::findType(llvm::StringRef File, Position Pos,
 928                             Callback<std::vector<LocatedSymbol>> CB) {
 929   auto Action = [Pos, CB = std::move(CB),
 930                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 931     if (!InpAST)
 932       return CB(InpAST.takeError());
 933     CB(clangd::findType(InpAST->AST, Pos, Index));
 934   };
 935   WorkScheduler->runWithAST("FindType", File, std::move(Action));
 936 }
 937
 938 void ClangdServer::findImplementations(
 939     PathRef File, Position Pos, Callback<std::vector<LocatedSymbol>> CB) {
 940   auto Action = [Pos, CB = std::move(CB),
 941                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 942     if (!InpAST)
 943       return CB(InpAST.takeError());
 944     CB(clangd::findImplementations(InpAST->AST, Pos, Index));
 945   };
 946
 947   WorkScheduler->runWithAST("Implementations", File, std::move(Action));
 948 }
 949
 950 void ClangdServer::findReferences(PathRef File, Position Pos, uint32_t Limit,
 951                                   bool AddContainer,
 952                                   Callback<ReferencesResult> CB) {
 953   auto Action = [Pos, Limit, AddContainer, CB = std::move(CB),
 954                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
 955     if (!InpAST)
 956       return CB(InpAST.takeError());
 957     CB(clangd::findReferences(InpAST->AST, Pos, Limit, Index, AddContainer));
 958   };
 959
 960   WorkScheduler->runWithAST("References", File, std::move(Action));
 961 }
 962
 963 void ClangdServer::symbolInfo(PathRef File, Position Pos,
 964                               Callback<std::vector<SymbolDetails>> CB) {
 965   auto Action =
 966       [Pos, CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
 967         if (!InpAST)
 968           return CB(InpAST.takeError());
 969         CB(clangd::getSymbolInfo(InpAST->AST, Pos));
 970       };
 971
 972   WorkScheduler->runWithAST("SymbolInfo", File, std::move(Action));
 973 }
 974
 975 void ClangdServer::semanticRanges(PathRef File,
 976                                   const std::vector<Position> &Positions,
 977                                   Callback<std::vector<SelectionRange>> CB) {
 978   auto Action = [Positions, CB = std::move(CB)](
 979                     llvm::Expected<InputsAndAST> InpAST) mutable {
 980     if (!InpAST)
 981       return CB(InpAST.takeError());
 982     std::vector<SelectionRange> Result;
 983     for (const auto &Pos : Positions) {
 984       if (auto Range = clangd::getSemanticRanges(InpAST->AST, Pos))
 985         Result.push_back(std::move(*Range));
 986       else
 987         return CB(Range.takeError());
 988     }
 989     CB(std::move(Result));
 990   };
 991   WorkScheduler->runWithAST("SemanticRanges", File, std::move(Action));
 992 }
 993
 994 void ClangdServer::documentLinks(PathRef File,
 995                                  Callback<std::vector<DocumentLink>> CB) {
 996   auto Action =
 997       [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
 998         if (!InpAST)
 999           return CB(InpAST.takeError());
1000         CB(clangd::getDocumentLinks(InpAST->AST));
1001       };
1002   WorkScheduler->runWithAST("DocumentLinks", File, std::move(Action),
1003                             Transient);
1004 }
1005
1006 void ClangdServer::semanticHighlights(
1007     PathRef File, Callback<std::vector<HighlightingToken>> CB) {
1008
1009   auto Action = [CB = std::move(CB),
1010                  PublishInactiveRegions = PublishInactiveRegions](
1011                     llvm::Expected<InputsAndAST> InpAST) mutable {
1012     if (!InpAST)
1013       return CB(InpAST.takeError());
1014     // Include inactive regions in semantic highlighting tokens only if the
1015     // client doesn't support a dedicated protocol for being informed about
1016     // them.
1017     CB(clangd::getSemanticHighlightings(InpAST->AST, !PublishInactiveRegions));
1018   };
1019   WorkScheduler->runWithAST("SemanticHighlights", File, std::move(Action),
1020                             Transient);
1021 }
1022
1023 void ClangdServer::getAST(PathRef File, std::optional<Range> R,
1024                           Callback<std::optional<ASTNode>> CB) {
1025   auto Action =
1026       [R, CB(std::move(CB))](llvm::Expected<InputsAndAST> Inputs) mutable {
1027         if (!Inputs)
1028           return CB(Inputs.takeError());
1029         if (!R) {
1030           // It's safe to pass in the TU, as dumpAST() does not
1031           // deserialize the preamble.
1032           auto Node = DynTypedNode::create(
1033               *Inputs->AST.getASTContext().getTranslationUnitDecl());
1034           return CB(dumpAST(Node, Inputs->AST.getTokens(),
1035                             Inputs->AST.getASTContext()));
1036         }
1037         unsigned Start, End;
1038         if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R->start))
1039           Start = *Offset;
1040         else
1041           return CB(Offset.takeError());
1042         if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R->end))
1043           End = *Offset;
1044         else
1045           return CB(Offset.takeError());
1046         bool Success = SelectionTree::createEach(
1047             Inputs->AST.getASTContext(), Inputs->AST.getTokens(), Start, End,
1048             [&](SelectionTree T) {
1049               if (const SelectionTree::Node *N = T.commonAncestor()) {
1050                 CB(dumpAST(N->ASTNode, Inputs->AST.getTokens(),
1051                            Inputs->AST.getASTContext()));
1052                 return true;
1053               }
1054               return false;
1055             });
1056         if (!Success)
1057           CB(std::nullopt);
1058       };
1059   WorkScheduler->runWithAST("GetAST", File, std::move(Action));
1060 }
1061
1062 void ClangdServer::customAction(PathRef File, llvm::StringRef Name,
1063                                 Callback<InputsAndAST> Action) {
1064   WorkScheduler->runWithAST(Name, File, std::move(Action));
1065 }
1066
1067 void ClangdServer::diagnostics(PathRef File, Callback<std::vector<Diag>> CB) {
1068   auto Action =
1069       [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
1070         if (!InpAST)
1071           return CB(InpAST.takeError());
1072         return CB(InpAST->AST.getDiagnostics());
1073       };
1074
1075   WorkScheduler->runWithAST("Diagnostics", File, std::move(Action));
1076 }
1077
1078 llvm::StringMap<TUScheduler::FileStats> ClangdServer::fileStats() const {
1079   return WorkScheduler->fileStats();
1080 }
1081
1082 [[nodiscard]] bool
1083 ClangdServer::blockUntilIdleForTest(std::optional<double> TimeoutSeconds) {
1084   // Order is important here: we don't want to block on A and then B,
1085   // if B might schedule work on A.
1086
1087 #if defined(__has_feature) &&                                                  \
1088     (__has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer) || \
1089      __has_feature(memory_sanitizer) || __has_feature(thread_sanitizer))
1090   if (TimeoutSeconds.has_value())
1091     (*TimeoutSeconds) *= 10;
1092 #endif
1093
1094   // Nothing else can schedule work on TUScheduler, because it's not threadsafe
1095   // and we're blocking the main thread.
1096   if (!WorkScheduler->blockUntilIdle(timeoutSeconds(TimeoutSeconds)))
1097     return false;
1098   // TUScheduler is the only thing that starts background indexing work.
1099   if (IndexTasks && !IndexTasks->wait(timeoutSeconds(TimeoutSeconds)))
1100     return false;
1101
1102   // Unfortunately we don't have strict topological order between the rest of
1103   // the components. E.g. CDB broadcast triggers backrgound indexing.
1104   // This queries the CDB which may discover new work if disk has changed.
1105   //
1106   // So try each one a few times in a loop.
1107   // If there are no tricky interactions then all after the first are no-ops.
1108   // Then on the last iteration, verify they're idle without waiting.
1109   //
1110   // There's a small chance they're juggling work and we didn't catch them :-(
1111   for (std::optional<double> Timeout :
1112        {TimeoutSeconds, TimeoutSeconds, std::optional<double>(0)}) {
1113     if (!CDB.blockUntilIdle(timeoutSeconds(Timeout)))
1114       return false;
1115     if (BackgroundIdx && !BackgroundIdx->blockUntilIdleForTest(Timeout))
1116       return false;
1117     if (FeatureModules && llvm::any_of(*FeatureModules, [&](FeatureModule &M) {
1118           return !M.blockUntilIdle(timeoutSeconds(Timeout));
1119         }))
1120       return false;
1121   }
1122
1123   assert(WorkScheduler->blockUntilIdle(Deadline::zero()) &&
1124          "Something scheduled work while we're blocking the main thread!");
1125   return true;
1126 }
1127
1128 void ClangdServer::profile(MemoryTree &MT) const {
1129   if (DynamicIdx)
1130     DynamicIdx->profile(MT.child("dynamic_index"));
1131   if (BackgroundIdx)
1132     BackgroundIdx->profile(MT.child("background_index"));
1133   WorkScheduler->profile(MT.child("tuscheduler"));
1134 }
1135 } // namespace clangd
1136 } // namespace clang