clang-tools  12.0.0git
GlobalCompilationDatabase.h
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1 //===--- GlobalCompilationDatabase.h -----------------------------*- 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_GLOBALCOMPILATIONDATABASE_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_GLOBALCOMPILATIONDATABASE_H
11 
12 #include "CompileCommands.h"
13 #include "support/Function.h"
14 #include "support/Path.h"
15 #include "clang/Tooling/ArgumentsAdjusters.h"
16 #include "clang/Tooling/CompilationDatabase.h"
17 #include "llvm/ADT/Optional.h"
18 #include "llvm/ADT/StringMap.h"
19 #include <memory>
20 #include <mutex>
21 #include <vector>
22 
23 namespace clang {
24 namespace clangd {
25 
26 class Logger;
27 
28 struct ProjectInfo {
29  // The directory in which the compilation database was discovered.
30  // Empty if directory-based compilation database discovery was not used.
31  std::string SourceRoot;
32 };
33 
34 /// Provides compilation arguments used for parsing C and C++ files.
36 public:
37  virtual ~GlobalCompilationDatabase() = default;
38 
39  /// If there are any known-good commands for building this file, returns one.
40  virtual llvm::Optional<tooling::CompileCommand>
41  getCompileCommand(PathRef File) const = 0;
42 
43  /// Finds the closest project to \p File.
44  virtual llvm::Optional<ProjectInfo> getProjectInfo(PathRef File) const {
45  return llvm::None;
46  }
47 
48  /// Makes a guess at how to build a file.
49  /// The default implementation just runs clang on the file.
50  /// Clangd should treat the results as unreliable.
51  virtual tooling::CompileCommand getFallbackCommand(PathRef File) const;
52 
54  /// The callback is notified when files may have new compile commands.
55  /// The argument is a list of full file paths.
56  CommandChanged::Subscription watch(CommandChanged::Listener L) const {
57  return OnCommandChanged.observe(std::move(L));
58  }
59 
60 protected:
62 };
63 
64 /// Gets compile args from tooling::CompilationDatabases built for parent
65 /// directories.
67  : public GlobalCompilationDatabase {
68 public:
70  llvm::Optional<Path> CompileCommandsDir);
72 
73  /// Scans File's parents looking for compilation databases.
74  /// Any extra flags will be added.
75  /// Might trigger OnCommandChanged, if CDB wasn't broadcasted yet.
76  llvm::Optional<tooling::CompileCommand>
77  getCompileCommand(PathRef File) const override;
78 
79  /// Returns the path to first directory containing a compilation database in
80  /// \p File's parents.
81  llvm::Optional<ProjectInfo> getProjectInfo(PathRef File) const override;
82 
83 private:
84  /// Caches compilation databases loaded from directories.
85  struct CachedCDB {
86  std::string Path; // Not case-folded.
87  std::unique_ptr<clang::tooling::CompilationDatabase> CDB = nullptr;
88  bool SentBroadcast = false;
89  };
90  CachedCDB &getCDBInDirLocked(PathRef File) const;
91 
92  struct CDBLookupRequest {
94  // Whether this lookup should trigger discovery of the CDB found.
95  bool ShouldBroadcast = false;
96  };
97  struct CDBLookupResult {
98  tooling::CompilationDatabase *CDB = nullptr;
99  ProjectInfo PI;
100  };
101  llvm::Optional<CDBLookupResult> lookupCDB(CDBLookupRequest Request) const;
102 
103  // Performs broadcast on governed files.
104  void broadcastCDB(CDBLookupResult Res) const;
105 
106  mutable std::mutex Mutex;
107  // Keyed by possibly-case-folded directory path.
108  mutable llvm::StringMap<CachedCDB> CompilationDatabases;
109 
110  /// Used for command argument pointing to folder where compile_commands.json
111  /// is located.
112  llvm::Optional<Path> CompileCommandsDir;
113 };
114 
115 /// Extracts system include search path from drivers matching QueryDriverGlobs
116 /// and adds them to the compile flags. Base may not be nullptr.
117 /// Returns Base when \p QueryDriverGlobs is empty.
118 std::unique_ptr<GlobalCompilationDatabase>
119 getQueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
120  std::unique_ptr<GlobalCompilationDatabase> Base);
121 
122 
123 /// Wraps another compilation database, and supports overriding the commands
124 /// using an in-memory mapping.
126 public:
127  // Base may be null, in which case no entries are inherited.
128  // FallbackFlags are added to the fallback compile command.
129  // Adjuster is applied to all commands, fallback or not.
131  std::vector<std::string> FallbackFlags = {},
132  tooling::ArgumentsAdjuster Adjuster = nullptr);
133 
134  llvm::Optional<tooling::CompileCommand>
135  getCompileCommand(PathRef File) const override;
136  tooling::CompileCommand getFallbackCommand(PathRef File) const override;
137  llvm::Optional<ProjectInfo> getProjectInfo(PathRef File) const override;
138 
139  /// Sets or clears the compilation command for a particular file.
140  void
141  setCompileCommand(PathRef File,
142  llvm::Optional<tooling::CompileCommand> CompilationCommand);
143 
144 private:
145  mutable std::mutex Mutex;
146  llvm::StringMap<tooling::CompileCommand> Commands; /* GUARDED_BY(Mut) */
148  tooling::ArgumentsAdjuster ArgsAdjuster;
149  std::vector<std::string> FallbackFlags;
150  CommandChanged::Subscription BaseChanged;
151 };
152 
153 } // namespace clangd
154 } // namespace clang
155 
156 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_GLOBALCOMPILATIONDATABASE_H
std::unique_ptr< GlobalCompilationDatabase > getQueryDriverDatabase(llvm::ArrayRef< std::string > QueryDriverGlobs, std::unique_ptr< GlobalCompilationDatabase > Base)
Extracts system include search path from drivers matching QueryDriverGlobs and adds them to the compi...
std::function< void(const std::vector< std::string > &)> Listener
Definition: Function.h:34
static cl::list< std::string > Commands("c", cl::desc("Specify command to run"), cl::value_desc("command"), cl::cat(ClangQueryCategory))
llvm::StringRef PathRef
A typedef to represent a ref to file path.
Definition: Path.h:23
Documents should not be synced at all.
Provides compilation arguments used for parsing C and C++ files.
std::string Path
A typedef to represent a file path.
Definition: Path.h:20
PathRef FileName
CommandChanged::Subscription watch(CommandChanged::Listener L) const
The callback is notified when files may have new compile commands.
Gets compile args from tooling::CompilationDatabases built for parent directories.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
std::unique_ptr< GlobalCompilationDatabase > Base
Wraps another compilation database, and supports overriding the commands using an in-memory mapping...
virtual llvm::Optional< ProjectInfo > getProjectInfo(PathRef File) const
Finds the closest project to File.