clang-tools  10.0.0git
ClangdServer.h
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1 //===--- ClangdServer.h - 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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDSERVER_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDSERVER_H
11 
12 #include "../clang-tidy/ClangTidyOptions.h"
13 #include "Cancellation.h"
14 #include "CodeComplete.h"
15 #include "FSProvider.h"
16 #include "FormattedString.h"
17 #include "Function.h"
19 #include "Hover.h"
20 #include "Protocol.h"
21 #include "SemanticHighlighting.h"
22 #include "TUScheduler.h"
23 #include "XRefs.h"
24 #include "index/Background.h"
25 #include "index/FileIndex.h"
26 #include "index/Index.h"
27 #include "refactor/Rename.h"
28 #include "refactor/Tweak.h"
29 #include "clang/Tooling/CompilationDatabase.h"
30 #include "clang/Tooling/Core/Replacement.h"
31 #include "llvm/ADT/FunctionExtras.h"
32 #include "llvm/ADT/IntrusiveRefCntPtr.h"
33 #include "llvm/ADT/Optional.h"
34 #include "llvm/ADT/StringRef.h"
35 #include <functional>
36 #include <future>
37 #include <string>
38 #include <type_traits>
39 #include <utility>
40 
41 namespace clang {
42 namespace clangd {
43 
44 // FIXME: find a better name.
46 public:
47  virtual ~DiagnosticsConsumer() = default;
48 
49  /// Called by ClangdServer when \p Diagnostics for \p File are ready.
50  virtual void onDiagnosticsReady(PathRef File,
51  std::vector<Diag> Diagnostics) = 0;
52  /// Called whenever the file status is updated.
53  virtual void onFileUpdated(PathRef File, const TUStatus &Status){};
54 
55  /// Called by ClangdServer when some \p Highlightings for \p File are ready.
56  virtual void
58  std::vector<HighlightingToken> Highlightings) {}
59 };
60 
61 /// When set, used by ClangdServer to get clang-tidy options for each particular
62 /// file. Must be thread-safe. We use this instead of ClangTidyOptionsProvider
63 /// to allow reading tidy configs from the VFS used for parsing.
65  llvm::vfs::FileSystem &, llvm::StringRef /*File*/)>;
66 
67 /// Manages a collection of source files and derived data (ASTs, indexes),
68 /// and provides language-aware features such as code completion.
69 ///
70 /// The primary client is ClangdLSPServer which exposes these features via
71 /// the Language Server protocol. ClangdServer may also be embedded directly,
72 /// though its API is not stable over time.
73 ///
74 /// ClangdServer should be used from a single thread. Many potentially-slow
75 /// operations have asynchronous APIs and deliver their results on another
76 /// thread.
77 /// Such operations support cancellation: if the caller sets up a cancelable
78 /// context, many operations will notice cancellation and fail early.
79 /// (ClangdLSPServer uses this to implement $/cancelRequest).
80 class ClangdServer {
81 public:
82  struct Options {
83  /// To process requests asynchronously, ClangdServer spawns worker threads.
84  /// If this is zero, no threads are spawned. All work is done on the calling
85  /// thread, and callbacks are invoked before "async" functions return.
86  unsigned AsyncThreadsCount = getDefaultAsyncThreadsCount();
87 
88  /// AST caching policy. The default is to keep up to 3 ASTs in memory.
90 
91  /// Cached preambles are potentially large. If false, store them on disk.
92  bool StorePreamblesInMemory = true;
93 
94  /// If true, ClangdServer builds a dynamic in-memory index for symbols in
95  /// opened files and uses the index to augment code completion results.
96  bool BuildDynamicSymbolIndex = false;
97  /// Use a heavier and faster in-memory index implementation.
98  bool HeavyweightDynamicSymbolIndex = true;
99  /// If true, ClangdServer automatically indexes files in the current project
100  /// on background threads. The index is stored in the project root.
101  bool BackgroundIndex = false;
102 
103  /// If set, use this index to augment code completion results.
104  SymbolIndex *StaticIndex = nullptr;
105 
106  /// If set, enable clang-tidy in clangd and use to it get clang-tidy
107  /// configurations for a particular file.
108  /// Clangd supports only a small subset of ClangTidyOptions, these options
109  /// (Checks, CheckOptions) are about which clang-tidy checks will be
110  /// enabled.
112 
113  /// Clangd's workspace root. Relevant for "workspace" operations not bound
114  /// to a particular file.
115  /// FIXME: If not set, should use the current working directory.
116  llvm::Optional<std::string> WorkspaceRoot;
117 
118  /// The resource directory is used to find internal headers, overriding
119  /// defaults and -resource-dir compiler flag).
120  /// If None, ClangdServer calls CompilerInvocation::GetResourcePath() to
121  /// obtain the standard resource directory.
122  llvm::Optional<std::string> ResourceDir = llvm::None;
123 
124  /// Time to wait after a new file version before computing diagnostics.
125  std::chrono::steady_clock::duration UpdateDebounce =
126  std::chrono::milliseconds(500);
127 
128  bool SuggestMissingIncludes = false;
129 
130  /// Clangd will execute compiler drivers matching one of these globs to
131  /// fetch system include path.
132  std::vector<std::string> QueryDriverGlobs;
133 
134  /// Enable semantic highlighting features.
135  bool SemanticHighlighting = false;
136 
137  /// Enable cross-file rename feature.
138  bool CrossFileRename = false;
139 
140  /// Returns true if the tweak should be enabled.
141  std::function<bool(const Tweak &)> TweakFilter = [](const Tweak &T) {
142  return !T.hidden(); // only enable non-hidden tweaks.
143  };
144  };
145  // Sensible default options for use in tests.
146  // Features like indexing must be enabled if desired.
147  static Options optsForTest();
148 
149  /// Creates a new ClangdServer instance.
150  ///
151  /// ClangdServer uses \p CDB to obtain compilation arguments for parsing. Note
152  /// that ClangdServer only obtains compilation arguments once for each newly
153  /// added file (i.e., when processing a first call to addDocument) and reuses
154  /// those arguments for subsequent reparses. However, ClangdServer will check
155  /// if compilation arguments changed on calls to forceReparse().
156  ///
157  /// After each parsing request finishes, ClangdServer reports diagnostics to
158  /// \p DiagConsumer. Note that a callback to \p DiagConsumer happens on a
159  /// worker thread. Therefore, instances of \p DiagConsumer must properly
160  /// synchronize access to shared state.
164 
165  /// Add a \p File to the list of tracked C++ files or update the contents if
166  /// \p File is already tracked. Also schedules parsing of the AST for it on a
167  /// separate thread. When the parsing is complete, DiagConsumer passed in
168  /// constructor will receive onDiagnosticsReady callback.
169  void addDocument(PathRef File, StringRef Contents,
171 
172  /// Get the contents of \p File, which should have been added.
173  llvm::StringRef getDocument(PathRef File) const;
174 
175  /// Remove \p File from list of tracked files, schedule a request to free
176  /// resources associated with it. Pending diagnostics for closed files may not
177  /// be delivered, even if requested with WantDiags::Auto or WantDiags::Yes.
178  void removeDocument(PathRef File);
179 
180  /// Run code completion for \p File at \p Pos.
181  /// Request is processed asynchronously.
182  ///
183  /// This method should only be called for currently tracked files. However, it
184  /// is safe to call removeDocument for \p File after this method returns, even
185  /// while returned future is not yet ready.
186  /// A version of `codeComplete` that runs \p Callback on the processing thread
187  /// when codeComplete results become available.
188  void codeComplete(PathRef File, Position Pos,
189  const clangd::CodeCompleteOptions &Opts,
191 
192  /// Provide signature help for \p File at \p Pos. This method should only be
193  /// called for tracked files.
195 
196  /// Find declaration/definition locations of symbol at a specified position.
197  void locateSymbolAt(PathRef File, Position Pos,
198  Callback<std::vector<LocatedSymbol>> CB);
199 
200  /// Switch to a corresponding source file when given a header file, and vice
201  /// versa.
202  void switchSourceHeader(PathRef Path,
203  Callback<llvm::Optional<clangd::Path>> CB);
204 
205  /// Get document highlights for a given position.
206  void findDocumentHighlights(PathRef File, Position Pos,
207  Callback<std::vector<DocumentHighlight>> CB);
208 
209  /// Get code hover for a given position.
210  void findHover(PathRef File, Position Pos,
211  Callback<llvm::Optional<HoverInfo>> CB);
212 
213  /// Get information about type hierarchy for a given position.
214  void typeHierarchy(PathRef File, Position Pos, int Resolve,
215  TypeHierarchyDirection Direction,
216  Callback<llvm::Optional<TypeHierarchyItem>> CB);
217 
218  /// Resolve type hierarchy item in the given direction.
219  void resolveTypeHierarchy(TypeHierarchyItem Item, int Resolve,
220  TypeHierarchyDirection Direction,
221  Callback<llvm::Optional<TypeHierarchyItem>> CB);
222 
223  /// Retrieve the top symbols from the workspace matching a query.
224  void workspaceSymbols(StringRef Query, int Limit,
225  Callback<std::vector<SymbolInformation>> CB);
226 
227  /// Retrieve the symbols within the specified file.
228  void documentSymbols(StringRef File,
229  Callback<std::vector<DocumentSymbol>> CB);
230 
231  /// Retrieve locations for symbol references.
232  void findReferences(PathRef File, Position Pos, uint32_t Limit,
234 
235  /// Run formatting for \p Rng inside \p File with content \p Code.
236  llvm::Expected<tooling::Replacements> formatRange(StringRef Code,
237  PathRef File, Range Rng);
238 
239  /// Run formatting for the whole \p File with content \p Code.
240  llvm::Expected<tooling::Replacements> formatFile(StringRef Code,
241  PathRef File);
242 
243  /// Run formatting after \p TriggerText was typed at \p Pos in \p File with
244  /// content \p Code.
245  llvm::Expected<std::vector<TextEdit>> formatOnType(StringRef Code,
246  PathRef File, Position Pos,
247  StringRef TriggerText);
248 
249  /// Test the validity of a rename operation.
250  void prepareRename(PathRef File, Position Pos,
251  Callback<llvm::Optional<Range>> CB);
252 
253  /// Rename all occurrences of the symbol at the \p Pos in \p File to
254  /// \p NewName.
255  /// If WantFormat is false, the final TextEdit will be not formatted,
256  /// embedders could use this method to get all occurrences of the symbol (e.g.
257  /// highlighting them in prepare stage).
258  void rename(PathRef File, Position Pos, llvm::StringRef NewName,
259  bool WantFormat, Callback<FileEdits> CB);
260 
261  struct TweakRef {
262  std::string ID; /// ID to pass for applyTweak.
263  std::string Title; /// A single-line message to show in the UI.
265  };
266  /// Enumerate the code tweaks available to the user at a specified point.
267  void enumerateTweaks(PathRef File, Range Sel,
268  Callback<std::vector<TweakRef>> CB);
269 
270  /// Apply the code tweak with a specified \p ID.
271  void applyTweak(PathRef File, Range Sel, StringRef ID,
273 
274  /// Only for testing purposes.
275  /// Waits until all requests to worker thread are finished and dumps AST for
276  /// \p File. \p File must be in the list of added documents.
277  void dumpAST(PathRef File, llvm::unique_function<void(std::string)> Callback);
278  /// Called when an event occurs for a watched file in the workspace.
279  void onFileEvent(const DidChangeWatchedFilesParams &Params);
280 
281  /// Get symbol info for given position.
282  /// Clangd extension - not part of official LSP.
283  void symbolInfo(PathRef File, Position Pos,
284  Callback<std::vector<SymbolDetails>> CB);
285 
286  /// Get semantic ranges around a specified position in a file.
287  void semanticRanges(PathRef File, Position Pos,
288  Callback<std::vector<Range>> CB);
289 
290  /// Get all document links in a file.
291  void documentLinks(PathRef File, Callback<std::vector<DocumentLink>> CB);
292 
293  /// Returns estimated memory usage for each of the currently open files.
294  /// The order of results is unspecified.
295  /// Overall memory usage of clangd may be significantly more than reported
296  /// here, as this metric does not account (at least) for:
297  /// - memory occupied by static and dynamic index,
298  /// - memory required for in-flight requests,
299  /// FIXME: those metrics might be useful too, we should add them.
300  std::vector<std::pair<Path, std::size_t>> getUsedBytesPerFile() const;
301 
302  // Blocks the main thread until the server is idle. Only for use in tests.
303  // Returns false if the timeout expires.
304  LLVM_NODISCARD bool
305  blockUntilIdleForTest(llvm::Optional<double> TimeoutSeconds = 10);
306 
307 private:
308  /// FIXME: This stats several files to find a .clang-format file. I/O can be
309  /// slow. Think of a way to cache this.
310  llvm::Expected<tooling::Replacements>
311  formatCode(llvm::StringRef Code, PathRef File,
312  ArrayRef<tooling::Range> Ranges);
313 
315 
316  Path ResourceDir;
317  // The index used to look up symbols. This could be:
318  // - null (all index functionality is optional)
319  // - the dynamic index owned by ClangdServer (DynamicIdx)
320  // - the static index passed to the constructor
321  // - a merged view of a static and dynamic index (MergedIndex)
322  const SymbolIndex *Index = nullptr;
323  // If present, an index of symbols in open files. Read via *Index.
324  std::unique_ptr<FileIndex> DynamicIdx;
325  // If present, the new "auto-index" maintained in background threads.
326  std::unique_ptr<BackgroundIndex> BackgroundIdx;
327  // Storage for merged views of the various indexes.
328  std::vector<std::unique_ptr<SymbolIndex>> MergedIdx;
329 
330  // When set, provides clang-tidy options for a specific file.
331  ClangTidyOptionsBuilder GetClangTidyOptions;
332 
333  // If this is true, suggest include insertion fixes for diagnostic errors that
334  // can be caused by missing includes (e.g. member access in incomplete type).
335  bool SuggestMissingIncludes = false;
336 
337  bool CrossFileRename = false;
338 
339  std::function<bool(const Tweak &)> TweakFilter;
340 
341  // GUARDED_BY(CachedCompletionFuzzyFindRequestMutex)
342  llvm::StringMap<llvm::Optional<FuzzyFindRequest>>
343  CachedCompletionFuzzyFindRequestByFile;
344  mutable std::mutex CachedCompletionFuzzyFindRequestMutex;
345 
346  llvm::Optional<std::string> WorkspaceRoot;
347  // WorkScheduler has to be the last member, because its destructor has to be
348  // called before all other members to stop the worker thread that references
349  // ClangdServer.
350  TUScheduler WorkScheduler;
351 };
352 
353 } // namespace clangd
354 } // namespace clang
355 
356 #endif
int Limit
std::string Code
WantDiagnostics
Determines whether diagnostics should be generated for a file snapshot.
Definition: TUScheduler.h:47
llvm::StringRef Contents
void dumpAST(ParsedAST &AST, llvm::raw_ostream &OS)
For testing/debugging purposes.
Definition: ParsedAST.cpp:213
void resolveTypeHierarchy(TypeHierarchyItem &Item, int ResolveLevels, TypeHierarchyDirection Direction, const SymbolIndex *Index)
Definition: XRefs.cpp:807
Intent
Output of a tweak.
Definition: Tweak.h:71
Interface for symbol indexes that can be used for searching or matching symbols among a set of symbol...
Definition: Index.h:85
llvm::StringRef PathRef
A typedef to represent a ref to file path.
Definition: Path.h:23
llvm::unique_function< void(llvm::Expected< T >)> Callback
A Callback<T> is a void function that accepts Expected<T>.
Definition: Function.h:28
Contains options for clang-tidy.
ReferencesResult findReferences(ParsedAST &AST, Position Pos, uint32_t Limit, const SymbolIndex *Index)
Returns references of the symbol at a specified Pos.
Definition: XRefs.cpp:423
Tweak::Intent Intent
A single-line message to show in the UI.
Definition: ClangdServer.h:264
Documents should not be synced at all.
ASTRetentionPolicy RetentionPolicy
AST caching policy. The default is to keep up to 3 ASTs in memory.
Definition: ClangdServer.h:89
MockFSProvider FSProvider
Configuration of the AST retention policy.
Definition: TUScheduler.h:57
std::string Title
ID to pass for applyTweak.
Definition: ClangdServer.h:263
SignatureHelp signatureHelp(PathRef FileName, const tooling::CompileCommand &Command, const PreambleData *Preamble, llvm::StringRef Contents, Position Pos, llvm::IntrusiveRefCntPtr< llvm::vfs::FileSystem > VFS, const SymbolIndex *Index)
Provides compilation arguments used for parsing C and C++ files.
std::string Path
A typedef to represent a file path.
Definition: Path.h:20
virtual void onDiagnosticsReady(PathRef File, std::vector< Diag > Diagnostics)=0
Called by ClangdServer when Diagnostics for File are ready.
virtual ~DiagnosticsConsumer()=default
std::function< tidy::ClangTidyOptions(llvm::vfs::FileSystem &, llvm::StringRef)> ClangTidyOptionsBuilder
When set, used by ClangdServer to get clang-tidy options for each particular file.
Definition: ClangdServer.h:65
Position Pos
Definition: SourceCode.cpp:772
std::vector< DocumentHighlight > findDocumentHighlights(ParsedAST &AST, Position Pos)
Returns highlights for all usages of a symbol at Pos.
Definition: XRefs.cpp:390
llvm::Optional< std::string > WorkspaceRoot
Clangd&#39;s workspace root.
Definition: ClangdServer.h:116
CodeCompleteResult codeComplete(PathRef FileName, const tooling::CompileCommand &Command, const PreambleData *Preamble, llvm::StringRef Contents, Position Pos, llvm::IntrusiveRefCntPtr< llvm::vfs::FileSystem > VFS, CodeCompleteOptions Opts, SpeculativeFuzzyFind *SpecFuzzyFind)
unsigned getDefaultAsyncThreadsCount()
Returns a number of a default async threads to use for TUScheduler.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
std::vector< std::string > QueryDriverGlobs
Clangd will execute compiler drivers matching one of these globs to fetch system include path...
Definition: ClangdServer.h:132
An interface base for small context-sensitive refactoring actions.
Definition: Tweak.h:46
IgnoreDiagnostics DiagConsumer
Manages a collection of source files and derived data (ASTs, indexes), and provides language-aware fe...
Definition: ClangdServer.h:80
std::vector< LocatedSymbol > locateSymbolAt(ParsedAST &AST, Position Pos, const SymbolIndex *Index)
Get definition of symbol at a specified Pos.
Definition: XRefs.cpp:190
ClangTidyOptionsBuilder GetClangTidyOptions
If set, enable clang-tidy in clangd and use to it get clang-tidy configurations for a particular file...
Definition: ClangdServer.h:111
Handles running tasks for ClangdServer and managing the resources (e.g., preambles and ASTs) for open...
Definition: TUScheduler.h:147
llvm::Expected< FileEdits > rename(const RenameInputs &RInputs)
Renames all occurrences of the symbol.
Definition: Rename.cpp:427
Diagnostics must not be generated for this snapshot.
virtual void onHighlightingsReady(PathRef File, std::vector< HighlightingToken > Highlightings)
Called by ClangdServer when some Highlightings for File are ready.
Definition: ClangdServer.h:57
virtual void onFileUpdated(PathRef File, const TUStatus &Status)
Called whenever the file status is updated.
Definition: ClangdServer.h:53
const SymbolIndex * Index
Definition: Dexp.cpp:84