Page MenuHomePhabricator

No OneTemporary

File Metadata

Fri, Jan 24, 4:02 PM


//===--- ClangdServer.h - Main clangd server code ----------------*- C++-*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "../clang-tidy/ClangTidyOptions.h"
#include "Cancellation.h"
#include "CodeComplete.h"
#include "FSProvider.h"
#include "FormattedString.h"
#include "Function.h"
#include "GlobalCompilationDatabase.h"
#include "Protocol.h"
#include "SemanticHighlighting.h"
#include "TUScheduler.h"
#include "XRefs.h"
#include "index/Background.h"
#include "index/FileIndex.h"
#include "index/Index.h"
#include "refactor/Tweak.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "clang/Tooling/Core/Replacement.h"
#include "llvm/ADT/FunctionExtras.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/StringRef.h"
#include <functional>
#include <future>
#include <string>
#include <type_traits>
#include <utility>
namespace clang {
namespace clangd {
// FIXME: find a better name.
class DiagnosticsConsumer {
virtual ~DiagnosticsConsumer() = default;
/// Called by ClangdServer when \p Diagnostics for \p File are ready.
virtual void onDiagnosticsReady(PathRef File,
std::vector<Diag> Diagnostics) = 0;
/// Called whenever the file status is updated.
virtual void onFileUpdated(PathRef File, const TUStatus &Status){};
/// Called by ClangdServer when some \p Highlightings for \p File are ready.
virtual void
onHighlightingsReady(PathRef File,
std::vector<HighlightingToken> Highlightings) {}
/// When set, used by ClangdServer to get clang-tidy options for each particular
/// file. Must be thread-safe. We use this instead of ClangTidyOptionsProvider
/// to allow reading tidy configs from the VFS used for parsing.
using ClangTidyOptionsBuilder = std::function<tidy::ClangTidyOptions(
llvm::vfs::FileSystem &, llvm::StringRef /*File*/)>;
/// Manages a collection of source files and derived data (ASTs, indexes),
/// and provides language-aware features such as code completion.
/// The primary client is ClangdLSPServer which exposes these features via
/// the Language Server protocol. ClangdServer may also be embedded directly,
/// though its API is not stable over time.
/// ClangdServer should be used from a single thread. Many potentially-slow
/// operations have asynchronous APIs and deliver their results on another
/// thread.
/// Such operations support cancellation: if the caller sets up a cancelable
/// context, many operations will notice cancellation and fail early.
/// (ClangdLSPServer uses this to implement $/cancelRequest).
class ClangdServer {
struct Options {
/// To process requests asynchronously, ClangdServer spawns worker threads.
/// If this is zero, no threads are spawned. All work is done on the calling
/// thread, and callbacks are invoked before "async" functions return.
unsigned AsyncThreadsCount = getDefaultAsyncThreadsCount();
/// AST caching policy. The default is to keep up to 3 ASTs in memory.
ASTRetentionPolicy RetentionPolicy;
/// Cached preambles are potentially large. If false, store them on disk.
bool StorePreamblesInMemory = true;
/// If true, ClangdServer builds a dynamic in-memory index for symbols in
/// opened files and uses the index to augment code completion results.
bool BuildDynamicSymbolIndex = false;
/// Use a heavier and faster in-memory index implementation.
bool HeavyweightDynamicSymbolIndex = true;
/// If true, ClangdServer automatically indexes files in the current project
/// on background threads. The index is stored in the project root.
bool BackgroundIndex = false;
/// If set, use this index to augment code completion results.
SymbolIndex *StaticIndex = nullptr;
/// If set, enable clang-tidy in clangd and use to it get clang-tidy
/// configurations for a particular file.
/// Clangd supports only a small subset of ClangTidyOptions, these options
/// (Checks, CheckOptions) are about which clang-tidy checks will be
/// enabled.
ClangTidyOptionsBuilder GetClangTidyOptions;
/// Clangd's workspace root. Relevant for "workspace" operations not bound
/// to a particular file.
/// FIXME: If not set, should use the current working directory.
llvm::Optional<std::string> WorkspaceRoot;
/// The resource directory is used to find internal headers, overriding
/// defaults and -resource-dir compiler flag).
/// If None, ClangdServer calls CompilerInvocation::GetResourcePath() to
/// obtain the standard resource directory.
llvm::Optional<std::string> ResourceDir = llvm::None;
/// Time to wait after a new file version before computing diagnostics.
std::chrono::steady_clock::duration UpdateDebounce =
bool SuggestMissingIncludes = false;
/// Clangd will execute compiler drivers matching one of these globs to
/// fetch system include path.
std::vector<std::string> QueryDriverGlobs;
/// Enable semantic highlighting features.
bool SemanticHighlighting = false;
/// Returns true if the tweak should be enabled.
std::function<bool(const Tweak &)> TweakFilter = [](const Tweak &T) {
return !T.hidden(); // only enable non-hidden tweaks.
// Sensible default options for use in tests.
// Features like indexing must be enabled if desired.
static Options optsForTest();
/// Creates a new ClangdServer instance.
/// ClangdServer uses \p CDB to obtain compilation arguments for parsing. Note
/// that ClangdServer only obtains compilation arguments once for each newly
/// added file (i.e., when processing a first call to addDocument) and reuses
/// those arguments for subsequent reparses. However, ClangdServer will check
/// if compilation arguments changed on calls to forceReparse().
/// After each parsing request finishes, ClangdServer reports diagnostics to
/// \p DiagConsumer. Note that a callback to \p DiagConsumer happens on a
/// worker thread. Therefore, instances of \p DiagConsumer must properly
/// synchronize access to shared state.
ClangdServer(const GlobalCompilationDatabase &CDB,
const FileSystemProvider &FSProvider,
DiagnosticsConsumer &DiagConsumer, const Options &Opts);
/// Add a \p File to the list of tracked C++ files or update the contents if
/// \p File is already tracked. Also schedules parsing of the AST for it on a
/// separate thread. When the parsing is complete, DiagConsumer passed in
/// constructor will receive onDiagnosticsReady callback.
void addDocument(PathRef File, StringRef Contents,
WantDiagnostics WD = WantDiagnostics::Auto);
/// Get the contents of \p File, which should have been added.
llvm::StringRef getDocument(PathRef File) const;
/// Remove \p File from list of tracked files, schedule a request to free
/// resources associated with it. Pending diagnostics for closed files may not
/// be delivered, even if requested with WantDiags::Auto or WantDiags::Yes.
void removeDocument(PathRef File);
/// Run code completion for \p File at \p Pos.
/// Request is processed asynchronously.
/// This method should only be called for currently tracked files. However, it
/// is safe to call removeDocument for \p File after this method returns, even
/// while returned future is not yet ready.
/// A version of `codeComplete` that runs \p Callback on the processing thread
/// when codeComplete results become available.
void codeComplete(PathRef File, Position Pos,
const clangd::CodeCompleteOptions &Opts,
Callback<CodeCompleteResult> CB);
/// Provide signature help for \p File at \p Pos. This method should only be
/// called for tracked files.
void signatureHelp(PathRef File, Position Pos, Callback<SignatureHelp> CB);
/// Find declaration/definition locations of symbol at a specified position.
void locateSymbolAt(PathRef File, Position Pos,
Callback<std::vector<LocatedSymbol>> CB);
/// Switch to a corresponding source file when given a header file, and vice
/// versa.
void switchSourceHeader(PathRef Path,
Callback<llvm::Optional<clangd::Path>> CB);
/// Get document highlights for a given position.
void findDocumentHighlights(PathRef File, Position Pos,
Callback<std::vector<DocumentHighlight>> CB);
/// Get code hover for a given position.
void findHover(PathRef File, Position Pos,
Callback<llvm::Optional<HoverInfo>> CB);
/// Get information about type hierarchy for a given position.
void typeHierarchy(PathRef File, Position Pos, int Resolve,
TypeHierarchyDirection Direction,
Callback<llvm::Optional<TypeHierarchyItem>> CB);
/// Resolve type hierarchy item in the given direction.
void resolveTypeHierarchy(TypeHierarchyItem Item, int Resolve,
TypeHierarchyDirection Direction,
Callback<llvm::Optional<TypeHierarchyItem>> CB);
/// Retrieve the top symbols from the workspace matching a query.
void workspaceSymbols(StringRef Query, int Limit,
Callback<std::vector<SymbolInformation>> CB);
/// Retrieve the symbols within the specified file.
void documentSymbols(StringRef File,
Callback<std::vector<DocumentSymbol>> CB);
/// Retrieve locations for symbol references.
void findReferences(PathRef File, Position Pos, uint32_t Limit,
Callback<std::vector<Location>> CB);
/// Run formatting for \p Rng inside \p File with content \p Code.
llvm::Expected<tooling::Replacements> formatRange(StringRef Code,
PathRef File, Range Rng);
/// Run formatting for the whole \p File with content \p Code.
llvm::Expected<tooling::Replacements> formatFile(StringRef Code,
PathRef File);
/// Run formatting after \p TriggerText was typed at \p Pos in \p File with
/// content \p Code.
llvm::Expected<std::vector<TextEdit>> formatOnType(StringRef Code,
PathRef File, Position Pos,
StringRef TriggerText);
/// Test the validity of a rename operation.
void prepareRename(PathRef File, Position Pos,
Callback<llvm::Optional<Range>> CB);
/// Rename all occurrences of the symbol at the \p Pos in \p File to
/// \p NewName.
/// If WantFormat is false, the final TextEdit will be not formatted,
/// embedders could use this method to get all occurrences of the symbol (e.g.
/// highlighting them in prepare stage).
void rename(PathRef File, Position Pos, llvm::StringRef NewName,
bool WantFormat, Callback<std::vector<TextEdit>> CB);
struct TweakRef {
std::string ID; /// ID to pass for applyTweak.
std::string Title; /// A single-line message to show in the UI.
Tweak::Intent Intent;
/// Enumerate the code tweaks available to the user at a specified point.
void enumerateTweaks(PathRef File, Range Sel,
Callback<std::vector<TweakRef>> CB);
/// Apply the code tweak with a specified \p ID.
void applyTweak(PathRef File, Range Sel, StringRef ID,
Callback<Tweak::Effect> CB);
/// Only for testing purposes.
/// Waits until all requests to worker thread are finished and dumps AST for
/// \p File. \p File must be in the list of added documents.
void dumpAST(PathRef File, llvm::unique_function<void(std::string)> Callback);
/// Called when an event occurs for a watched file in the workspace.
void onFileEvent(const DidChangeWatchedFilesParams &Params);
/// Get symbol info for given position.
/// Clangd extension - not part of official LSP.
void symbolInfo(PathRef File, Position Pos,
Callback<std::vector<SymbolDetails>> CB);
/// Get semantic ranges around a specified position in a file.
void semanticRanges(PathRef File, Position Pos,
Callback<std::vector<Range>> CB);
/// Returns estimated memory usage for each of the currently open files.
/// The order of results is unspecified.
/// Overall memory usage of clangd may be significantly more than reported
/// here, as this metric does not account (at least) for:
/// - memory occupied by static and dynamic index,
/// - memory required for in-flight requests,
/// FIXME: those metrics might be useful too, we should add them.
std::vector<std::pair<Path, std::size_t>> getUsedBytesPerFile() const;
// Blocks the main thread until the server is idle. Only for use in tests.
// Returns false if the timeout expires.
blockUntilIdleForTest(llvm::Optional<double> TimeoutSeconds = 10);
/// FIXME: This stats several files to find a .clang-format file. I/O can be
/// slow. Think of a way to cache this.
formatCode(llvm::StringRef Code, PathRef File,
ArrayRef<tooling::Range> Ranges);
const FileSystemProvider &FSProvider;
Path ResourceDir;
// The index used to look up symbols. This could be:
// - null (all index functionality is optional)
// - the dynamic index owned by ClangdServer (DynamicIdx)
// - the static index passed to the constructor
// - a merged view of a static and dynamic index (MergedIndex)
const SymbolIndex *Index = nullptr;
// If present, an index of symbols in open files. Read via *Index.
std::unique_ptr<FileIndex> DynamicIdx;
// If present, the new "auto-index" maintained in background threads.
std::unique_ptr<BackgroundIndex> BackgroundIdx;
// Storage for merged views of the various indexes.
std::vector<std::unique_ptr<SymbolIndex>> MergedIdx;
// When set, provides clang-tidy options for a specific file.
ClangTidyOptionsBuilder GetClangTidyOptions;
// If this is true, suggest include insertion fixes for diagnostic errors that
// can be caused by missing includes (e.g. member access in incomplete type).
bool SuggestMissingIncludes = false;
std::function<bool(const Tweak &)> TweakFilter;
// GUARDED_BY(CachedCompletionFuzzyFindRequestMutex)
mutable std::mutex CachedCompletionFuzzyFindRequestMutex;
llvm::Optional<std::string> WorkspaceRoot;
// WorkScheduler has to be the last member, because its destructor has to be
// called before all other members to stop the worker thread that references
// ClangdServer.
TUScheduler WorkScheduler;
} // namespace clangd
} // namespace clang

Event Timeline