llvm-project

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//===--- ClangdServer.cpp - Main clangd server code --------------*- C++-*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===-------------------------------------------------------------------===//
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#include "ClangdServer.h"
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#include "CodeComplete.h"
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#include "Config.h"
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#include "Diagnostics.h"
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#include "DumpAST.h"
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#include "FindSymbols.h"
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#include "Format.h"
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#include "HeaderSourceSwitch.h"
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#include "InlayHints.h"
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#include "ParsedAST.h"
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#include "Preamble.h"
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#include "Protocol.h"
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#include "SemanticHighlighting.h"
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#include "SemanticSelection.h"
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#include "SourceCode.h"
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#include "TUScheduler.h"
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#include "XRefs.h"
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#include "clang-include-cleaner/Record.h"
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#include "index/FileIndex.h"
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#include "index/Merge.h"
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#include "index/StdLib.h"
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#include "refactor/Rename.h"
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#include "refactor/Tweak.h"
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#include "support/Cancellation.h"
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#include "support/Context.h"
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#include "support/Logger.h"
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#include "support/MemoryTree.h"
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#include "support/ThreadsafeFS.h"
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#include "support/Trace.h"
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#include "clang/Basic/Stack.h"
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#include "clang/Format/Format.h"
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#include "clang/Lex/Preprocessor.h"
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#include "clang/Tooling/CompilationDatabase.h"
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#include "clang/Tooling/Core/Replacement.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/Error.h"
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#include "llvm/Support/Path.h"
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#include "llvm/Support/raw_ostream.h"
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#include <algorithm>
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#include <chrono>
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#include <future>
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#include <memory>
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#include <mutex>
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#include <optional>
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#include <string>
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#include <type_traits>
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#include <utility>
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#include <vector>
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namespace clang {
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namespace clangd {
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namespace {
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// Tracks number of times a tweak has been offered.
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static constexpr trace::Metric TweakAvailable(
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    "tweak_available", trace::Metric::Counter, "tweak_id");
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// Update the FileIndex with new ASTs and plumb the diagnostics responses.
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struct UpdateIndexCallbacks : public ParsingCallbacks {
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  UpdateIndexCallbacks(FileIndex *FIndex,
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                       ClangdServer::Callbacks *ServerCallbacks,
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                       const ThreadsafeFS &TFS, AsyncTaskRunner *Tasks,
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                       bool CollectInactiveRegions)
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      : FIndex(FIndex), ServerCallbacks(ServerCallbacks), TFS(TFS),
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        Stdlib{std::make_shared<StdLibSet>()}, Tasks(Tasks),
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        CollectInactiveRegions(CollectInactiveRegions) {}
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  void onPreambleAST(
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      PathRef Path, llvm::StringRef Version, CapturedASTCtx ASTCtx,
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      std::shared_ptr<const include_cleaner::PragmaIncludes> PI) override {
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    if (!FIndex)
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      return;
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    auto &PP = ASTCtx.getPreprocessor();
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    auto &CI = ASTCtx.getCompilerInvocation();
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    if (auto Loc = Stdlib->add(CI.getLangOpts(), PP.getHeaderSearchInfo()))
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      indexStdlib(CI, std::move(*Loc));
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    // FIndex outlives the UpdateIndexCallbacks.
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    auto Task = [FIndex(FIndex), Path(Path.str()), Version(Version.str()),
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                 ASTCtx(std::move(ASTCtx)), PI(std::move(PI))]() mutable {
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      trace::Span Tracer("PreambleIndexing");
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      FIndex->updatePreamble(Path, Version, ASTCtx.getASTContext(),
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                             ASTCtx.getPreprocessor(), *PI);
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    };
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    if (Tasks) {
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      Tasks->runAsync("Preamble indexing for:" + Path + Version,
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                      std::move(Task));
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    } else
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      Task();
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  }
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  void indexStdlib(const CompilerInvocation &CI, StdLibLocation Loc) {
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    // This task is owned by Tasks, which outlives the TUScheduler and
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    // therefore the UpdateIndexCallbacks.
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    // We must be careful that the references we capture outlive TUScheduler.
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    auto Task = [LO(CI.getLangOpts()), Loc(std::move(Loc)),
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                 CI(std::make_unique<CompilerInvocation>(CI)),
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                 // External values that outlive ClangdServer
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                 TFS(&TFS),
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                 // Index outlives TUScheduler (declared first)
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                 FIndex(FIndex),
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                 // shared_ptr extends lifetime
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                 Stdlib(Stdlib),
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                 // We have some FS implementations that rely on information in
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                 // the context.
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                 Ctx(Context::current().clone())]() mutable {
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      // Make sure we install the context into current thread.
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      WithContext C(std::move(Ctx));
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      clang::noteBottomOfStack();
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      IndexFileIn IF;
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      IF.Symbols = indexStandardLibrary(std::move(CI), Loc, *TFS);
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      if (Stdlib->isBest(LO))
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        FIndex->updatePreamble(std::move(IF));
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    };
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    if (Tasks)
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      // This doesn't have a semaphore to enforce -j, but it's rare.
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      Tasks->runAsync("IndexStdlib", std::move(Task));
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    else
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      Task();
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  }
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  void onMainAST(PathRef Path, ParsedAST &AST, PublishFn Publish) override {
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    if (FIndex)
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      FIndex->updateMain(Path, AST);
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    if (ServerCallbacks)
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      Publish([&]() {
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        ServerCallbacks->onDiagnosticsReady(Path, AST.version(),
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                                            AST.getDiagnostics());
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        if (CollectInactiveRegions) {
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          ServerCallbacks->onInactiveRegionsReady(Path,
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                                                  getInactiveRegions(AST));
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        }
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      });
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  }
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  void onFailedAST(PathRef Path, llvm::StringRef Version,
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                   std::vector<Diag> Diags, PublishFn Publish) override {
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    if (ServerCallbacks)
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      Publish(
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          [&]() { ServerCallbacks->onDiagnosticsReady(Path, Version, Diags); });
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  }
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  void onFileUpdated(PathRef File, const TUStatus &Status) override {
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    if (ServerCallbacks)
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      ServerCallbacks->onFileUpdated(File, Status);
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  }
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  void onPreamblePublished(PathRef File) override {
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    if (ServerCallbacks)
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      ServerCallbacks->onSemanticsMaybeChanged(File);
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  }
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private:
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  FileIndex *FIndex;
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  ClangdServer::Callbacks *ServerCallbacks;
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  const ThreadsafeFS &TFS;
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  std::shared_ptr<StdLibSet> Stdlib;
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  AsyncTaskRunner *Tasks;
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  bool CollectInactiveRegions;
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};
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class DraftStoreFS : public ThreadsafeFS {
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public:
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  DraftStoreFS(const ThreadsafeFS &Base, const DraftStore &Drafts)
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      : Base(Base), DirtyFiles(Drafts) {}
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private:
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  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> viewImpl() const override {
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    auto OFS = llvm::makeIntrusiveRefCnt<llvm::vfs::OverlayFileSystem>(
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        Base.view(std::nullopt));
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    OFS->pushOverlay(DirtyFiles.asVFS());
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    return OFS;
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  }
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  const ThreadsafeFS &Base;
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  const DraftStore &DirtyFiles;
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};
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} // namespace
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ClangdServer::Options ClangdServer::optsForTest() {
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  ClangdServer::Options Opts;
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  Opts.UpdateDebounce = DebouncePolicy::fixed(/*zero*/ {});
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  Opts.StorePreamblesInMemory = true;
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  Opts.AsyncThreadsCount = 4; // Consistent!
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  return Opts;
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}
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ClangdServer::Options::operator TUScheduler::Options() const {
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  TUScheduler::Options Opts;
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  Opts.AsyncThreadsCount = AsyncThreadsCount;
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  Opts.RetentionPolicy = RetentionPolicy;
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  Opts.StorePreamblesInMemory = StorePreamblesInMemory;
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  Opts.UpdateDebounce = UpdateDebounce;
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  Opts.ContextProvider = ContextProvider;
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  Opts.PreambleThrottler = PreambleThrottler;
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  return Opts;
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}
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ClangdServer::ClangdServer(const GlobalCompilationDatabase &CDB,
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                           const ThreadsafeFS &TFS, const Options &Opts,
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                           Callbacks *Callbacks)
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    : FeatureModules(Opts.FeatureModules), CDB(CDB), TFS(TFS),
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      DynamicIdx(Opts.BuildDynamicSymbolIndex ? new FileIndex() : nullptr),
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      ClangTidyProvider(Opts.ClangTidyProvider),
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      UseDirtyHeaders(Opts.UseDirtyHeaders),
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      LineFoldingOnly(Opts.LineFoldingOnly),
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      PreambleParseForwardingFunctions(Opts.PreambleParseForwardingFunctions),
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      ImportInsertions(Opts.ImportInsertions),
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      PublishInactiveRegions(Opts.PublishInactiveRegions),
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      WorkspaceRoot(Opts.WorkspaceRoot),
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      Transient(Opts.ImplicitCancellation ? TUScheduler::InvalidateOnUpdate
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                                          : TUScheduler::NoInvalidation),
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      DirtyFS(std::make_unique<DraftStoreFS>(TFS, DraftMgr)) {
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  if (Opts.AsyncThreadsCount != 0)
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    IndexTasks.emplace();
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  // Pass a callback into `WorkScheduler` to extract symbols from a newly
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  // parsed file and rebuild the file index synchronously each time an AST
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  // is parsed.
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  WorkScheduler.emplace(CDB, TUScheduler::Options(Opts),
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                        std::make_unique<UpdateIndexCallbacks>(
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                            DynamicIdx.get(), Callbacks, TFS,
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                            IndexTasks ? &*IndexTasks : nullptr,
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                            PublishInactiveRegions));
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  // Adds an index to the stack, at higher priority than existing indexes.
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  auto AddIndex = [&](SymbolIndex *Idx) {
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    if (this->Index != nullptr) {
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      MergedIdx.push_back(std::make_unique<MergedIndex>(Idx, this->Index));
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      this->Index = MergedIdx.back().get();
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    } else {
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      this->Index = Idx;
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    }
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  };
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  if (Opts.StaticIndex)
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    AddIndex(Opts.StaticIndex);
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  if (Opts.BackgroundIndex) {
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    BackgroundIndex::Options BGOpts;
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    BGOpts.ThreadPoolSize = std::max(Opts.AsyncThreadsCount, 1u);
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    BGOpts.OnProgress = [Callbacks](BackgroundQueue::Stats S) {
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      if (Callbacks)
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        Callbacks->onBackgroundIndexProgress(S);
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    };
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    BGOpts.ContextProvider = Opts.ContextProvider;
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    BackgroundIdx = std::make_unique<BackgroundIndex>(
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        TFS, CDB,
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        BackgroundIndexStorage::createDiskBackedStorageFactory(
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            [&CDB](llvm::StringRef File) { return CDB.getProjectInfo(File); }),
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        std::move(BGOpts));
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    AddIndex(BackgroundIdx.get());
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  }
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  if (DynamicIdx)
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    AddIndex(DynamicIdx.get());
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  if (Opts.FeatureModules) {
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    FeatureModule::Facilities F{
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        *this->WorkScheduler,
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        this->Index,
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        this->TFS,
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    };
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    for (auto &Mod : *Opts.FeatureModules)
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      Mod.initialize(F);
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  }
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}
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ClangdServer::~ClangdServer() {
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  // Destroying TUScheduler first shuts down request threads that might
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  // otherwise access members concurrently.
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  // (Nobody can be using TUScheduler because we're on the main thread).
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  WorkScheduler.reset();
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  // Now requests have stopped, we can shut down feature modules.
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  if (FeatureModules) {
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    for (auto &Mod : *FeatureModules)
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      Mod.stop();
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    for (auto &Mod : *FeatureModules)
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      Mod.blockUntilIdle(Deadline::infinity());
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  }
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}
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void ClangdServer::addDocument(PathRef File, llvm::StringRef Contents,
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                               llvm::StringRef Version,
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                               WantDiagnostics WantDiags, bool ForceRebuild) {
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  std::string ActualVersion = DraftMgr.addDraft(File, Version, Contents);
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  ParseOptions Opts;
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  Opts.PreambleParseForwardingFunctions = PreambleParseForwardingFunctions;
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  Opts.ImportInsertions = ImportInsertions;
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  // Compile command is set asynchronously during update, as it can be slow.
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  ParseInputs Inputs;
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  Inputs.TFS = &getHeaderFS();
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  Inputs.Contents = std::string(Contents);
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  Inputs.Version = std::move(ActualVersion);
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  Inputs.ForceRebuild = ForceRebuild;
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  Inputs.Opts = std::move(Opts);
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  Inputs.Index = Index;
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  Inputs.ClangTidyProvider = ClangTidyProvider;
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  Inputs.FeatureModules = FeatureModules;
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  bool NewFile = WorkScheduler->update(File, Inputs, WantDiags);
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  // If we loaded Foo.h, we want to make sure Foo.cpp is indexed.
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  if (NewFile && BackgroundIdx)
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    BackgroundIdx->boostRelated(File);
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}
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void ClangdServer::reparseOpenFilesIfNeeded(
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    llvm::function_ref<bool(llvm::StringRef File)> Filter) {
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  // Reparse only opened files that were modified.
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  for (const Path &FilePath : DraftMgr.getActiveFiles())
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    if (Filter(FilePath))
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      if (auto Draft = DraftMgr.getDraft(FilePath)) // else disappeared in race?
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        addDocument(FilePath, *Draft->Contents, Draft->Version,
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                    WantDiagnostics::Auto);
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}
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std::shared_ptr<const std::string> ClangdServer::getDraft(PathRef File) const {
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  auto Draft = DraftMgr.getDraft(File);
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  if (!Draft)
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    return nullptr;
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  return std::move(Draft->Contents);
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}
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std::function<Context(PathRef)>
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ClangdServer::createConfiguredContextProvider(const config::Provider *Provider,
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                                              Callbacks *Publish) {
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  if (!Provider)
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    return [](llvm::StringRef) { return Context::current().clone(); };
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  struct Impl {
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    const config::Provider *Provider;
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    ClangdServer::Callbacks *Publish;
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    std::mutex PublishMu;
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    Impl(const config::Provider *Provider, ClangdServer::Callbacks *Publish)
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        : Provider(Provider), Publish(Publish) {}
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    Context operator()(llvm::StringRef File) {
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      config::Params Params;
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      // Don't reread config files excessively often.
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      // FIXME: when we see a config file change event, use the event timestamp?
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      Params.FreshTime =
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          std::chrono::steady_clock::now() - std::chrono::seconds(5);
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      llvm::SmallString<256> PosixPath;
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      if (!File.empty()) {
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        assert(llvm::sys::path::is_absolute(File));
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        llvm::sys::path::native(File, PosixPath, llvm::sys::path::Style::posix);
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        Params.Path = PosixPath.str();
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      }
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      llvm::StringMap<std::vector<Diag>> ReportableDiagnostics;
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      Config C = Provider->getConfig(Params, [&](const llvm::SMDiagnostic &D) {
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        // Create the map entry even for note diagnostics we don't report.
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        // This means that when the file is parsed with no warnings, we
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        // publish an empty set of diagnostics, clearing any the client has.
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        handleDiagnostic(D, !Publish || D.getFilename().empty()
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                                ? nullptr
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                                : &ReportableDiagnostics[D.getFilename()]);
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      });
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      // Blindly publish diagnostics for the (unopened) parsed config files.
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      // We must avoid reporting diagnostics for *the same file* concurrently.
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      // Source diags are published elsewhere, but those are different files.
373
      if (!ReportableDiagnostics.empty()) {
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        std::lock_guard<std::mutex> Lock(PublishMu);
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        for (auto &Entry : ReportableDiagnostics)
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          Publish->onDiagnosticsReady(Entry.first(), /*Version=*/"",
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                                      Entry.second);
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      }
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      return Context::current().derive(Config::Key, std::move(C));
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    }
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    void handleDiagnostic(const llvm::SMDiagnostic &D,
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                          std::vector<Diag> *ClientDiagnostics) {
384
      switch (D.getKind()) {
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      case llvm::SourceMgr::DK_Error:
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        elog("config error at {0}:{1}:{2}: {3}", D.getFilename(), D.getLineNo(),
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             D.getColumnNo(), D.getMessage());
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        break;
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      case llvm::SourceMgr::DK_Warning:
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        log("config warning at {0}:{1}:{2}: {3}", D.getFilename(),
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            D.getLineNo(), D.getColumnNo(), D.getMessage());
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        break;
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      case llvm::SourceMgr::DK_Note:
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      case llvm::SourceMgr::DK_Remark:
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        vlog("config note at {0}:{1}:{2}: {3}", D.getFilename(), D.getLineNo(),
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             D.getColumnNo(), D.getMessage());
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        ClientDiagnostics = nullptr; // Don't emit notes as LSP diagnostics.
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        break;
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      }
400
      if (ClientDiagnostics)
401
        ClientDiagnostics->push_back(toDiag(D, Diag::ClangdConfig));
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    }
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  };
404

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  // Copyable wrapper.
406
  return [I(std::make_shared<Impl>(Provider, Publish))](llvm::StringRef Path) {
407
    return (*I)(Path);
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  };
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}
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void ClangdServer::removeDocument(PathRef File) {
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  DraftMgr.removeDraft(File);
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  WorkScheduler->remove(File);
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}
415

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void ClangdServer::codeComplete(PathRef File, Position Pos,
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                                const clangd::CodeCompleteOptions &Opts,
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                                Callback<CodeCompleteResult> CB) {
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  // Copy completion options for passing them to async task handler.
420
  auto CodeCompleteOpts = Opts;
421
  if (!CodeCompleteOpts.Index) // Respect overridden index.
422
    CodeCompleteOpts.Index = Index;
423

424
  auto Task = [Pos, CodeCompleteOpts, File = File.str(), CB = std::move(CB),
425
               this](llvm::Expected<InputsAndPreamble> IP) mutable {
426
    if (!IP)
427
      return CB(IP.takeError());
428
    if (auto Reason = isCancelled())
429
      return CB(llvm::make_error<CancelledError>(Reason));
430

431
    std::optional<SpeculativeFuzzyFind> SpecFuzzyFind;
432
    if (!IP->Preamble) {
433
      // No speculation in Fallback mode, as it's supposed to be much faster
434
      // without compiling.
435
      vlog("Build for file {0} is not ready. Enter fallback mode.", File);
436
    } else if (CodeCompleteOpts.Index) {
437
      SpecFuzzyFind.emplace();
438
      {
439
        std::lock_guard<std::mutex> Lock(CachedCompletionFuzzyFindRequestMutex);
440
        SpecFuzzyFind->CachedReq = CachedCompletionFuzzyFindRequestByFile[File];
441
      }
442
    }
443
    ParseInputs ParseInput{IP->Command, &getHeaderFS(), IP->Contents.str()};
444
    // FIXME: Add traling new line if there is none at eof, workaround a crash,
445
    // see https://github.com/clangd/clangd/issues/332
446
    if (!IP->Contents.ends_with("\n"))
447
      ParseInput.Contents.append("\n");
448
    ParseInput.Index = Index;
449

450
    CodeCompleteOpts.MainFileSignals = IP->Signals;
451
    CodeCompleteOpts.AllScopes = Config::current().Completion.AllScopes;
452
    // FIXME(ibiryukov): even if Preamble is non-null, we may want to check
453
    // both the old and the new version in case only one of them matches.
454
    CodeCompleteResult Result = clangd::codeComplete(
455
        File, Pos, IP->Preamble, ParseInput, CodeCompleteOpts,
456
        SpecFuzzyFind ? &*SpecFuzzyFind : nullptr);
457
    {
458
      clang::clangd::trace::Span Tracer("Completion results callback");
459
      CB(std::move(Result));
460
    }
461
    if (SpecFuzzyFind && SpecFuzzyFind->NewReq) {
462
      std::lock_guard<std::mutex> Lock(CachedCompletionFuzzyFindRequestMutex);
463
      CachedCompletionFuzzyFindRequestByFile[File] = *SpecFuzzyFind->NewReq;
464
    }
465
    // SpecFuzzyFind is only destroyed after speculative fuzzy find finishes.
466
    // We don't want `codeComplete` to wait for the async call if it doesn't use
467
    // the result (e.g. non-index completion, speculation fails), so that `CB`
468
    // is called as soon as results are available.
469
  };
470

471
  // We use a potentially-stale preamble because latency is critical here.
472
  WorkScheduler->runWithPreamble(
473
      "CodeComplete", File,
474
      (Opts.RunParser == CodeCompleteOptions::AlwaysParse)
475
          ? TUScheduler::Stale
476
          : TUScheduler::StaleOrAbsent,
477
      std::move(Task));
478
}
479

480
void ClangdServer::signatureHelp(PathRef File, Position Pos,
481
                                 MarkupKind DocumentationFormat,
482
                                 Callback<SignatureHelp> CB) {
483

484
  auto Action = [Pos, File = File.str(), CB = std::move(CB),
485
                 DocumentationFormat,
486
                 this](llvm::Expected<InputsAndPreamble> IP) mutable {
487
    if (!IP)
488
      return CB(IP.takeError());
489

490
    const auto *PreambleData = IP->Preamble;
491
    if (!PreambleData)
492
      return CB(error("Failed to parse includes"));
493

494
    ParseInputs ParseInput{IP->Command, &getHeaderFS(), IP->Contents.str()};
495
    // FIXME: Add traling new line if there is none at eof, workaround a crash,
496
    // see https://github.com/clangd/clangd/issues/332
497
    if (!IP->Contents.ends_with("\n"))
498
      ParseInput.Contents.append("\n");
499
    ParseInput.Index = Index;
500
    CB(clangd::signatureHelp(File, Pos, *PreambleData, ParseInput,
501
                             DocumentationFormat));
502
  };
503

504
  // Unlike code completion, we wait for a preamble here.
505
  WorkScheduler->runWithPreamble("SignatureHelp", File, TUScheduler::Stale,
506
                                 std::move(Action));
507
}
508

509
void ClangdServer::formatFile(PathRef File, std::optional<Range> Rng,
510
                              Callback<tooling::Replacements> CB) {
511
  auto Code = getDraft(File);
512
  if (!Code)
513
    return CB(llvm::make_error<LSPError>("trying to format non-added document",
514
                                         ErrorCode::InvalidParams));
515
  tooling::Range RequestedRange;
516
  if (Rng) {
517
    llvm::Expected<size_t> Begin = positionToOffset(*Code, Rng->start);
518
    if (!Begin)
519
      return CB(Begin.takeError());
520
    llvm::Expected<size_t> End = positionToOffset(*Code, Rng->end);
521
    if (!End)
522
      return CB(End.takeError());
523
    RequestedRange = tooling::Range(*Begin, *End - *Begin);
524
  } else {
525
    RequestedRange = tooling::Range(0, Code->size());
526
  }
527

528
  // Call clang-format.
529
  auto Action = [File = File.str(), Code = std::move(*Code),
530
                 Ranges = std::vector<tooling::Range>{RequestedRange},
531
                 CB = std::move(CB), this]() mutable {
532
    format::FormatStyle Style = getFormatStyleForFile(File, Code, TFS, true);
533
    tooling::Replacements IncludeReplaces =
534
        format::sortIncludes(Style, Code, Ranges, File);
535
    auto Changed = tooling::applyAllReplacements(Code, IncludeReplaces);
536
    if (!Changed)
537
      return CB(Changed.takeError());
538

539
    CB(IncludeReplaces.merge(format::reformat(
540
        Style, *Changed,
541
        tooling::calculateRangesAfterReplacements(IncludeReplaces, Ranges),
542
        File)));
543
  };
544
  WorkScheduler->runQuick("Format", File, std::move(Action));
545
}
546

547
void ClangdServer::formatOnType(PathRef File, Position Pos,
548
                                StringRef TriggerText,
549
                                Callback<std::vector<TextEdit>> CB) {
550
  auto Code = getDraft(File);
551
  if (!Code)
552
    return CB(llvm::make_error<LSPError>("trying to format non-added document",
553
                                         ErrorCode::InvalidParams));
554
  llvm::Expected<size_t> CursorPos = positionToOffset(*Code, Pos);
555
  if (!CursorPos)
556
    return CB(CursorPos.takeError());
557
  auto Action = [File = File.str(), Code = std::move(*Code),
558
                 TriggerText = TriggerText.str(), CursorPos = *CursorPos,
559
                 CB = std::move(CB), this]() mutable {
560
    auto Style = getFormatStyleForFile(File, Code, TFS, false);
561
    std::vector<TextEdit> Result;
562
    for (const tooling::Replacement &R :
563
         formatIncremental(Code, CursorPos, TriggerText, Style))
564
      Result.push_back(replacementToEdit(Code, R));
565
    return CB(Result);
566
  };
567
  WorkScheduler->runQuick("FormatOnType", File, std::move(Action));
568
}
569

570
void ClangdServer::prepareRename(PathRef File, Position Pos,
571
                                 std::optional<std::string> NewName,
572
                                 const RenameOptions &RenameOpts,
573
                                 Callback<RenameResult> CB) {
574
  auto Action = [Pos, File = File.str(), CB = std::move(CB),
575
                 NewName = std::move(NewName),
576
                 RenameOpts](llvm::Expected<InputsAndAST> InpAST) mutable {
577
    if (!InpAST)
578
      return CB(InpAST.takeError());
579
    // prepareRename is latency-sensitive: we don't query the index, as we
580
    // only need main-file references
581
    auto Results =
582
        clangd::rename({Pos, NewName.value_or("__clangd_rename_placeholder"),
583
                        InpAST->AST, File, /*FS=*/nullptr,
584
                        /*Index=*/nullptr, RenameOpts});
585
    if (!Results) {
586
      // LSP says to return null on failure, but that will result in a generic
587
      // failure message. If we send an LSP error response, clients can surface
588
      // the message to users (VSCode does).
589
      return CB(Results.takeError());
590
    }
591
    return CB(*Results);
592
  };
593
  WorkScheduler->runWithAST("PrepareRename", File, std::move(Action));
594
}
595

596
void ClangdServer::rename(PathRef File, Position Pos, llvm::StringRef NewName,
597
                          const RenameOptions &Opts,
598
                          Callback<RenameResult> CB) {
599
  auto Action = [File = File.str(), NewName = NewName.str(), Pos, Opts,
600
                 CB = std::move(CB),
601
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
602
    // Tracks number of files edited per invocation.
603
    static constexpr trace::Metric RenameFiles("rename_files",
604
                                               trace::Metric::Distribution);
605
    if (!InpAST)
606
      return CB(InpAST.takeError());
607
    auto R = clangd::rename({Pos, NewName, InpAST->AST, File,
608
                             DirtyFS->view(std::nullopt), Index, Opts});
609
    if (!R)
610
      return CB(R.takeError());
611

612
    if (Opts.WantFormat) {
613
      auto Style = getFormatStyleForFile(File, InpAST->Inputs.Contents,
614
                                         *InpAST->Inputs.TFS, false);
615
      llvm::Error Err = llvm::Error::success();
616
      for (auto &E : R->GlobalChanges)
617
        Err =
618
            llvm::joinErrors(reformatEdit(E.getValue(), Style), std::move(Err));
619

620
      if (Err)
621
        return CB(std::move(Err));
622
    }
623
    RenameFiles.record(R->GlobalChanges.size());
624
    return CB(*R);
625
  };
626
  WorkScheduler->runWithAST("Rename", File, std::move(Action));
627
}
628

629
namespace {
630
// May generate several candidate selections, due to SelectionTree ambiguity.
631
// vector of pointers because GCC doesn't like non-copyable Selection.
632
llvm::Expected<std::vector<std::unique_ptr<Tweak::Selection>>>
633
tweakSelection(const Range &Sel, const InputsAndAST &AST,
634
               llvm::vfs::FileSystem *FS) {
635
  auto Begin = positionToOffset(AST.Inputs.Contents, Sel.start);
636
  if (!Begin)
637
    return Begin.takeError();
638
  auto End = positionToOffset(AST.Inputs.Contents, Sel.end);
639
  if (!End)
640
    return End.takeError();
641
  std::vector<std::unique_ptr<Tweak::Selection>> Result;
642
  SelectionTree::createEach(
643
      AST.AST.getASTContext(), AST.AST.getTokens(), *Begin, *End,
644
      [&](SelectionTree T) {
645
        Result.push_back(std::make_unique<Tweak::Selection>(
646
            AST.Inputs.Index, AST.AST, *Begin, *End, std::move(T), FS));
647
        return false;
648
      });
649
  assert(!Result.empty() && "Expected at least one SelectionTree");
650
  return std::move(Result);
651
}
652

653
// Some fixes may perform local renaming, we want to convert those to clangd
654
// rename commands, such that we can leverage the index for more accurate
655
// results.
656
std::optional<ClangdServer::CodeActionResult::Rename>
657
tryConvertToRename(const Diag *Diag, const Fix &Fix) {
658
  bool IsClangTidyRename = Diag->Source == Diag::ClangTidy &&
659
                           Diag->Name == "readability-identifier-naming" &&
660
                           !Fix.Edits.empty();
661
  if (IsClangTidyRename && Diag->InsideMainFile) {
662
    ClangdServer::CodeActionResult::Rename R;
663
    R.NewName = Fix.Edits.front().newText;
664
    R.FixMessage = Fix.Message;
665
    R.Diag = {Diag->Range, Diag->Message};
666
    return R;
667
  }
668

669
  return std::nullopt;
670
}
671

672
} // namespace
673

674
void ClangdServer::codeAction(const CodeActionInputs &Params,
675
                              Callback<CodeActionResult> CB) {
676
  auto Action = [Params, CB = std::move(CB),
677
                 FeatureModules(this->FeatureModules)](
678
                    Expected<InputsAndAST> InpAST) mutable {
679
    if (!InpAST)
680
      return CB(InpAST.takeError());
681
    auto KindAllowed =
682
        [Only(Params.RequestedActionKinds)](llvm::StringRef Kind) {
683
          if (Only.empty())
684
            return true;
685
          return llvm::any_of(Only, [&](llvm::StringRef Base) {
686
            return Kind.consume_front(Base) &&
687
                   (Kind.empty() || Kind.starts_with("."));
688
          });
689
        };
690

691
    CodeActionResult Result;
692
    Result.Version = InpAST->AST.version().str();
693
    if (KindAllowed(CodeAction::QUICKFIX_KIND)) {
694
      auto FindMatchedDiag = [&InpAST](const DiagRef &DR) -> const Diag * {
695
        for (const auto &Diag : InpAST->AST.getDiagnostics())
696
          if (Diag.Range == DR.Range && Diag.Message == DR.Message)
697
            return &Diag;
698
        return nullptr;
699
      };
700
      for (const auto &DiagRef : Params.Diagnostics) {
701
        if (const auto *Diag = FindMatchedDiag(DiagRef))
702
          for (const auto &Fix : Diag->Fixes) {
703
            if (auto Rename = tryConvertToRename(Diag, Fix)) {
704
              Result.Renames.emplace_back(std::move(*Rename));
705
            } else {
706
              Result.QuickFixes.push_back({DiagRef, Fix});
707
            }
708
          }
709
      }
710
    }
711

712
    // Collect Tweaks
713
    auto Selections = tweakSelection(Params.Selection, *InpAST, /*FS=*/nullptr);
714
    if (!Selections)
715
      return CB(Selections.takeError());
716
    // Don't allow a tweak to fire more than once across ambiguous selections.
717
    llvm::DenseSet<llvm::StringRef> PreparedTweaks;
718
    auto DeduplicatingFilter = [&](const Tweak &T) {
719
      return KindAllowed(T.kind()) && Params.TweakFilter(T) &&
720
             !PreparedTweaks.count(T.id());
721
    };
722
    for (const auto &Sel : *Selections) {
723
      for (auto &T : prepareTweaks(*Sel, DeduplicatingFilter, FeatureModules)) {
724
        Result.TweakRefs.push_back(TweakRef{T->id(), T->title(), T->kind()});
725
        PreparedTweaks.insert(T->id());
726
        TweakAvailable.record(1, T->id());
727
      }
728
    }
729
    CB(std::move(Result));
730
  };
731

732
  WorkScheduler->runWithAST("codeAction", Params.File, std::move(Action),
733
                            Transient);
734
}
735

736
void ClangdServer::applyTweak(PathRef File, Range Sel, StringRef TweakID,
737
                              Callback<Tweak::Effect> CB) {
738
  // Tracks number of times a tweak has been attempted.
739
  static constexpr trace::Metric TweakAttempt(
740
      "tweak_attempt", trace::Metric::Counter, "tweak_id");
741
  // Tracks number of times a tweak has failed to produce edits.
742
  static constexpr trace::Metric TweakFailed(
743
      "tweak_failed", trace::Metric::Counter, "tweak_id");
744
  TweakAttempt.record(1, TweakID);
745
  auto Action = [File = File.str(), Sel, TweakID = TweakID.str(),
746
                 CB = std::move(CB),
747
                 this](Expected<InputsAndAST> InpAST) mutable {
748
    if (!InpAST)
749
      return CB(InpAST.takeError());
750
    auto FS = DirtyFS->view(std::nullopt);
751
    auto Selections = tweakSelection(Sel, *InpAST, FS.get());
752
    if (!Selections)
753
      return CB(Selections.takeError());
754
    std::optional<llvm::Expected<Tweak::Effect>> Effect;
755
    // Try each selection, take the first one that prepare()s.
756
    // If they all fail, Effect will hold get the last error.
757
    for (const auto &Selection : *Selections) {
758
      auto T = prepareTweak(TweakID, *Selection, FeatureModules);
759
      if (T) {
760
        Effect = (*T)->apply(*Selection);
761
        break;
762
      }
763
      Effect = T.takeError();
764
    }
765
    assert(Effect && "Expected at least one selection");
766
    if (*Effect && (*Effect)->FormatEdits) {
767
      // Format tweaks that require it centrally here.
768
      for (auto &It : (*Effect)->ApplyEdits) {
769
        Edit &E = It.second;
770
        format::FormatStyle Style =
771
            getFormatStyleForFile(File, E.InitialCode, TFS, false);
772
        if (llvm::Error Err = reformatEdit(E, Style))
773
          elog("Failed to format {0}: {1}", It.first(), std::move(Err));
774
      }
775
    } else {
776
      TweakFailed.record(1, TweakID);
777
    }
778
    return CB(std::move(*Effect));
779
  };
780
  WorkScheduler->runWithAST("ApplyTweak", File, std::move(Action));
781
}
782

783
void ClangdServer::locateSymbolAt(PathRef File, Position Pos,
784
                                  Callback<std::vector<LocatedSymbol>> CB) {
785
  auto Action = [Pos, CB = std::move(CB),
786
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
787
    if (!InpAST)
788
      return CB(InpAST.takeError());
789
    CB(clangd::locateSymbolAt(InpAST->AST, Pos, Index));
790
  };
791

792
  WorkScheduler->runWithAST("Definitions", File, std::move(Action));
793
}
794

795
void ClangdServer::switchSourceHeader(
796
    PathRef Path, Callback<std::optional<clangd::Path>> CB) {
797
  // We want to return the result as fast as possible, strategy is:
798
  //  1) use the file-only heuristic, it requires some IO but it is much
799
  //     faster than building AST, but it only works when .h/.cc files are in
800
  //     the same directory.
801
  //  2) if 1) fails, we use the AST&Index approach, it is slower but supports
802
  //     different code layout.
803
  if (auto CorrespondingFile =
804
          getCorrespondingHeaderOrSource(Path, TFS.view(std::nullopt)))
805
    return CB(std::move(CorrespondingFile));
806
  auto Action = [Path = Path.str(), CB = std::move(CB),
807
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
808
    if (!InpAST)
809
      return CB(InpAST.takeError());
810
    CB(getCorrespondingHeaderOrSource(Path, InpAST->AST, Index));
811
  };
812
  WorkScheduler->runWithAST("SwitchHeaderSource", Path, std::move(Action));
813
}
814

815
void ClangdServer::findDocumentHighlights(
816
    PathRef File, Position Pos, Callback<std::vector<DocumentHighlight>> CB) {
817
  auto Action =
818
      [Pos, CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
819
        if (!InpAST)
820
          return CB(InpAST.takeError());
821
        CB(clangd::findDocumentHighlights(InpAST->AST, Pos));
822
      };
823

824
  WorkScheduler->runWithAST("Highlights", File, std::move(Action), Transient);
825
}
826

827
void ClangdServer::findHover(PathRef File, Position Pos,
828
                             Callback<std::optional<HoverInfo>> CB) {
829
  auto Action = [File = File.str(), Pos, CB = std::move(CB),
830
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
831
    if (!InpAST)
832
      return CB(InpAST.takeError());
833
    format::FormatStyle Style = getFormatStyleForFile(
834
        File, InpAST->Inputs.Contents, *InpAST->Inputs.TFS, false);
835
    CB(clangd::getHover(InpAST->AST, Pos, std::move(Style), Index));
836
  };
837

838
  WorkScheduler->runWithAST("Hover", File, std::move(Action), Transient);
839
}
840

841
void ClangdServer::typeHierarchy(PathRef File, Position Pos, int Resolve,
842
                                 TypeHierarchyDirection Direction,
843
                                 Callback<std::vector<TypeHierarchyItem>> CB) {
844
  auto Action = [File = File.str(), Pos, Resolve, Direction, CB = std::move(CB),
845
                 this](Expected<InputsAndAST> InpAST) mutable {
846
    if (!InpAST)
847
      return CB(InpAST.takeError());
848
    CB(clangd::getTypeHierarchy(InpAST->AST, Pos, Resolve, Direction, Index,
849
                                File));
850
  };
851

852
  WorkScheduler->runWithAST("TypeHierarchy", File, std::move(Action));
853
}
854

855
void ClangdServer::superTypes(
856
    const TypeHierarchyItem &Item,
857
    Callback<std::optional<std::vector<TypeHierarchyItem>>> CB) {
858
  WorkScheduler->run("typeHierarchy/superTypes", /*Path=*/"",
859
                     [=, CB = std::move(CB)]() mutable {
860
                       CB(clangd::superTypes(Item, Index));
861
                     });
862
}
863

864
void ClangdServer::subTypes(const TypeHierarchyItem &Item,
865
                            Callback<std::vector<TypeHierarchyItem>> CB) {
866
  WorkScheduler->run(
867
      "typeHierarchy/subTypes", /*Path=*/"",
868
      [=, CB = std::move(CB)]() mutable { CB(clangd::subTypes(Item, Index)); });
869
}
870

871
void ClangdServer::resolveTypeHierarchy(
872
    TypeHierarchyItem Item, int Resolve, TypeHierarchyDirection Direction,
873
    Callback<std::optional<TypeHierarchyItem>> CB) {
874
  WorkScheduler->run(
875
      "Resolve Type Hierarchy", "", [=, CB = std::move(CB)]() mutable {
876
        clangd::resolveTypeHierarchy(Item, Resolve, Direction, Index);
877
        CB(Item);
878
      });
879
}
880

881
void ClangdServer::prepareCallHierarchy(
882
    PathRef File, Position Pos, Callback<std::vector<CallHierarchyItem>> CB) {
883
  auto Action = [File = File.str(), Pos,
884
                 CB = std::move(CB)](Expected<InputsAndAST> InpAST) mutable {
885
    if (!InpAST)
886
      return CB(InpAST.takeError());
887
    CB(clangd::prepareCallHierarchy(InpAST->AST, Pos, File));
888
  };
889
  WorkScheduler->runWithAST("CallHierarchy", File, std::move(Action));
890
}
891

892
void ClangdServer::incomingCalls(
893
    const CallHierarchyItem &Item,
894
    Callback<std::vector<CallHierarchyIncomingCall>> CB) {
895
  WorkScheduler->run("Incoming Calls", "",
896
                     [CB = std::move(CB), Item, this]() mutable {
897
                       CB(clangd::incomingCalls(Item, Index));
898
                     });
899
}
900

901
void ClangdServer::inlayHints(PathRef File, std::optional<Range> RestrictRange,
902
                              Callback<std::vector<InlayHint>> CB) {
903
  auto Action = [RestrictRange(std::move(RestrictRange)),
904
                 CB = std::move(CB)](Expected<InputsAndAST> InpAST) mutable {
905
    if (!InpAST)
906
      return CB(InpAST.takeError());
907
    CB(clangd::inlayHints(InpAST->AST, std::move(RestrictRange)));
908
  };
909
  WorkScheduler->runWithAST("InlayHints", File, std::move(Action), Transient);
910
}
911

912
void ClangdServer::onFileEvent(const DidChangeWatchedFilesParams &Params) {
913
  // FIXME: Do nothing for now. This will be used for indexing and potentially
914
  // invalidating other caches.
915
}
916

917
void ClangdServer::workspaceSymbols(
918
    llvm::StringRef Query, int Limit,
919
    Callback<std::vector<SymbolInformation>> CB) {
920
  WorkScheduler->run(
921
      "getWorkspaceSymbols", /*Path=*/"",
922
      [Query = Query.str(), Limit, CB = std::move(CB), this]() mutable {
923
        CB(clangd::getWorkspaceSymbols(Query, Limit, Index,
924
                                       WorkspaceRoot.value_or("")));
925
      });
926
}
927

928
void ClangdServer::documentSymbols(llvm::StringRef File,
929
                                   Callback<std::vector<DocumentSymbol>> CB) {
930
  auto Action =
931
      [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
932
        if (!InpAST)
933
          return CB(InpAST.takeError());
934
        CB(clangd::getDocumentSymbols(InpAST->AST));
935
      };
936
  WorkScheduler->runWithAST("DocumentSymbols", File, std::move(Action),
937
                            Transient);
938
}
939

940
void ClangdServer::foldingRanges(llvm::StringRef File,
941
                                 Callback<std::vector<FoldingRange>> CB) {
942
  auto Code = getDraft(File);
943
  if (!Code)
944
    return CB(llvm::make_error<LSPError>(
945
        "trying to compute folding ranges for non-added document",
946
        ErrorCode::InvalidParams));
947
  auto Action = [LineFoldingOnly = LineFoldingOnly, CB = std::move(CB),
948
                 Code = std::move(*Code)]() mutable {
949
    CB(clangd::getFoldingRanges(Code, LineFoldingOnly));
950
  };
951
  // We want to make sure folding ranges are always available for all the open
952
  // files, hence prefer runQuick to not wait for operations on other files.
953
  WorkScheduler->runQuick("FoldingRanges", File, std::move(Action));
954
}
955

956
void ClangdServer::findType(llvm::StringRef File, Position Pos,
957
                            Callback<std::vector<LocatedSymbol>> CB) {
958
  auto Action = [Pos, CB = std::move(CB),
959
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
960
    if (!InpAST)
961
      return CB(InpAST.takeError());
962
    CB(clangd::findType(InpAST->AST, Pos, Index));
963
  };
964
  WorkScheduler->runWithAST("FindType", File, std::move(Action));
965
}
966

967
void ClangdServer::findImplementations(
968
    PathRef File, Position Pos, Callback<std::vector<LocatedSymbol>> CB) {
969
  auto Action = [Pos, CB = std::move(CB),
970
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
971
    if (!InpAST)
972
      return CB(InpAST.takeError());
973
    CB(clangd::findImplementations(InpAST->AST, Pos, Index));
974
  };
975

976
  WorkScheduler->runWithAST("Implementations", File, std::move(Action));
977
}
978

979
void ClangdServer::findReferences(PathRef File, Position Pos, uint32_t Limit,
980
                                  bool AddContainer,
981
                                  Callback<ReferencesResult> CB) {
982
  auto Action = [Pos, Limit, AddContainer, CB = std::move(CB),
983
                 this](llvm::Expected<InputsAndAST> InpAST) mutable {
984
    if (!InpAST)
985
      return CB(InpAST.takeError());
986
    CB(clangd::findReferences(InpAST->AST, Pos, Limit, Index, AddContainer));
987
  };
988

989
  WorkScheduler->runWithAST("References", File, std::move(Action));
990
}
991

992
void ClangdServer::symbolInfo(PathRef File, Position Pos,
993
                              Callback<std::vector<SymbolDetails>> CB) {
994
  auto Action =
995
      [Pos, CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
996
        if (!InpAST)
997
          return CB(InpAST.takeError());
998
        CB(clangd::getSymbolInfo(InpAST->AST, Pos));
999
      };
1000

1001
  WorkScheduler->runWithAST("SymbolInfo", File, std::move(Action));
1002
}
1003

1004
void ClangdServer::semanticRanges(PathRef File,
1005
                                  const std::vector<Position> &Positions,
1006
                                  Callback<std::vector<SelectionRange>> CB) {
1007
  auto Action = [Positions, CB = std::move(CB)](
1008
                    llvm::Expected<InputsAndAST> InpAST) mutable {
1009
    if (!InpAST)
1010
      return CB(InpAST.takeError());
1011
    std::vector<SelectionRange> Result;
1012
    for (const auto &Pos : Positions) {
1013
      if (auto Range = clangd::getSemanticRanges(InpAST->AST, Pos))
1014
        Result.push_back(std::move(*Range));
1015
      else
1016
        return CB(Range.takeError());
1017
    }
1018
    CB(std::move(Result));
1019
  };
1020
  WorkScheduler->runWithAST("SemanticRanges", File, std::move(Action));
1021
}
1022

1023
void ClangdServer::documentLinks(PathRef File,
1024
                                 Callback<std::vector<DocumentLink>> CB) {
1025
  auto Action =
1026
      [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
1027
        if (!InpAST)
1028
          return CB(InpAST.takeError());
1029
        CB(clangd::getDocumentLinks(InpAST->AST));
1030
      };
1031
  WorkScheduler->runWithAST("DocumentLinks", File, std::move(Action),
1032
                            Transient);
1033
}
1034

1035
void ClangdServer::semanticHighlights(
1036
    PathRef File, Callback<std::vector<HighlightingToken>> CB) {
1037

1038
  auto Action = [CB = std::move(CB),
1039
                 PublishInactiveRegions = PublishInactiveRegions](
1040
                    llvm::Expected<InputsAndAST> InpAST) mutable {
1041
    if (!InpAST)
1042
      return CB(InpAST.takeError());
1043
    // Include inactive regions in semantic highlighting tokens only if the
1044
    // client doesn't support a dedicated protocol for being informed about
1045
    // them.
1046
    CB(clangd::getSemanticHighlightings(InpAST->AST, !PublishInactiveRegions));
1047
  };
1048
  WorkScheduler->runWithAST("SemanticHighlights", File, std::move(Action),
1049
                            Transient);
1050
}
1051

1052
void ClangdServer::getAST(PathRef File, std::optional<Range> R,
1053
                          Callback<std::optional<ASTNode>> CB) {
1054
  auto Action =
1055
      [R, CB(std::move(CB))](llvm::Expected<InputsAndAST> Inputs) mutable {
1056
        if (!Inputs)
1057
          return CB(Inputs.takeError());
1058
        if (!R) {
1059
          // It's safe to pass in the TU, as dumpAST() does not
1060
          // deserialize the preamble.
1061
          auto Node = DynTypedNode::create(
1062
              *Inputs->AST.getASTContext().getTranslationUnitDecl());
1063
          return CB(dumpAST(Node, Inputs->AST.getTokens(),
1064
                            Inputs->AST.getASTContext()));
1065
        }
1066
        unsigned Start, End;
1067
        if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R->start))
1068
          Start = *Offset;
1069
        else
1070
          return CB(Offset.takeError());
1071
        if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R->end))
1072
          End = *Offset;
1073
        else
1074
          return CB(Offset.takeError());
1075
        bool Success = SelectionTree::createEach(
1076
            Inputs->AST.getASTContext(), Inputs->AST.getTokens(), Start, End,
1077
            [&](SelectionTree T) {
1078
              if (const SelectionTree::Node *N = T.commonAncestor()) {
1079
                CB(dumpAST(N->ASTNode, Inputs->AST.getTokens(),
1080
                           Inputs->AST.getASTContext()));
1081
                return true;
1082
              }
1083
              return false;
1084
            });
1085
        if (!Success)
1086
          CB(std::nullopt);
1087
      };
1088
  WorkScheduler->runWithAST("GetAST", File, std::move(Action));
1089
}
1090

1091
void ClangdServer::customAction(PathRef File, llvm::StringRef Name,
1092
                                Callback<InputsAndAST> Action) {
1093
  WorkScheduler->runWithAST(Name, File, std::move(Action));
1094
}
1095

1096
void ClangdServer::diagnostics(PathRef File, Callback<std::vector<Diag>> CB) {
1097
  auto Action =
1098
      [CB = std::move(CB)](llvm::Expected<InputsAndAST> InpAST) mutable {
1099
        if (!InpAST)
1100
          return CB(InpAST.takeError());
1101
        return CB(InpAST->AST.getDiagnostics());
1102
      };
1103

1104
  WorkScheduler->runWithAST("Diagnostics", File, std::move(Action));
1105
}
1106

1107
llvm::StringMap<TUScheduler::FileStats> ClangdServer::fileStats() const {
1108
  return WorkScheduler->fileStats();
1109
}
1110

1111
[[nodiscard]] bool
1112
ClangdServer::blockUntilIdleForTest(std::optional<double> TimeoutSeconds) {
1113
  // Order is important here: we don't want to block on A and then B,
1114
  // if B might schedule work on A.
1115

1116
#if defined(__has_feature) &&                                                  \
1117
    (__has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer) || \
1118
     __has_feature(memory_sanitizer) || __has_feature(thread_sanitizer))
1119
  if (TimeoutSeconds.has_value())
1120
    (*TimeoutSeconds) *= 10;
1121
#endif
1122

1123
  // Nothing else can schedule work on TUScheduler, because it's not threadsafe
1124
  // and we're blocking the main thread.
1125
  if (!WorkScheduler->blockUntilIdle(timeoutSeconds(TimeoutSeconds)))
1126
    return false;
1127
  // TUScheduler is the only thing that starts background indexing work.
1128
  if (IndexTasks && !IndexTasks->wait(timeoutSeconds(TimeoutSeconds)))
1129
    return false;
1130

1131
  // Unfortunately we don't have strict topological order between the rest of
1132
  // the components. E.g. CDB broadcast triggers backrgound indexing.
1133
  // This queries the CDB which may discover new work if disk has changed.
1134
  //
1135
  // So try each one a few times in a loop.
1136
  // If there are no tricky interactions then all after the first are no-ops.
1137
  // Then on the last iteration, verify they're idle without waiting.
1138
  //
1139
  // There's a small chance they're juggling work and we didn't catch them :-(
1140
  for (std::optional<double> Timeout :
1141
       {TimeoutSeconds, TimeoutSeconds, std::optional<double>(0)}) {
1142
    if (!CDB.blockUntilIdle(timeoutSeconds(Timeout)))
1143
      return false;
1144
    if (BackgroundIdx && !BackgroundIdx->blockUntilIdleForTest(Timeout))
1145
      return false;
1146
    if (FeatureModules && llvm::any_of(*FeatureModules, [&](FeatureModule &M) {
1147
          return !M.blockUntilIdle(timeoutSeconds(Timeout));
1148
        }))
1149
      return false;
1150
  }
1151

1152
  assert(WorkScheduler->blockUntilIdle(Deadline::zero()) &&
1153
         "Something scheduled work while we're blocking the main thread!");
1154
  return true;
1155
}
1156

1157
void ClangdServer::profile(MemoryTree &MT) const {
1158
  if (DynamicIdx)
1159
    DynamicIdx->profile(MT.child("dynamic_index"));
1160
  if (BackgroundIdx)
1161
    BackgroundIdx->profile(MT.child("background_index"));
1162
  WorkScheduler->profile(MT.child("tuscheduler"));
1163
}
1164
} // namespace clangd
1165
} // namespace clang
1166