JSONCompilationDatabase.h revision 355940 
1//===- JSONCompilationDatabase.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//  The JSONCompilationDatabase finds compilation databases supplied as a file
10//  'compile_commands.json'.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H
15#define LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H
16
17#include "clang/Basic/LLVM.h"
18#include "clang/Tooling/CompilationDatabase.h"
19#include "clang/Tooling/FileMatchTrie.h"
20#include "llvm/ADT/ArrayRef.h"
21#include "llvm/ADT/StringMap.h"
22#include "llvm/ADT/StringRef.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include "llvm/Support/SourceMgr.h"
25#include "llvm/Support/YAMLParser.h"
26#include <memory>
27#include <string>
28#include <tuple>
29#include <utility>
30#include <vector>
31
32namespace clang {
33namespace tooling {
34
35/// A JSON based compilation database.
36///
37/// JSON compilation database files must contain a list of JSON objects which
38/// provide the command lines in the attributes 'directory', 'command',
39/// 'arguments' and 'file':
40/// [
41///   { "directory": "<working directory of the compile>",
42///     "command": "<compile command line>",
43///     "file": "<path to source file>"
44///   },
45///   { "directory": "<working directory of the compile>",
46///     "arguments": ["<raw>", "<command>" "<line>" "<parameters>"],
47///     "file": "<path to source file>"
48///   },
49///   ...
50/// ]
51/// Each object entry defines one compile action. The specified file is
52/// considered to be the main source file for the translation unit.
53///
54/// 'command' is a full command line that will be unescaped.
55///
56/// 'arguments' is a list of command line arguments that will not be unescaped.
57///
58/// JSON compilation databases can for example be generated in CMake projects
59/// by setting the flag -DCMAKE_EXPORT_COMPILE_COMMANDS.
60enum class JSONCommandLineSyntax { Windows, Gnu, AutoDetect };
61class JSONCompilationDatabase : public CompilationDatabase {
62public:
63  /// Loads a JSON compilation database from the specified file.
64  ///
65  /// Returns NULL and sets ErrorMessage if the database could not be
66  /// loaded from the given file.
67  static std::unique_ptr<JSONCompilationDatabase>
68  loadFromFile(StringRef FilePath, std::string &ErrorMessage,
69               JSONCommandLineSyntax Syntax);
70
71  /// Loads a JSON compilation database from a data buffer.
72  ///
73  /// Returns NULL and sets ErrorMessage if the database could not be loaded.
74  static std::unique_ptr<JSONCompilationDatabase>
75  loadFromBuffer(StringRef DatabaseString, std::string &ErrorMessage,
76                 JSONCommandLineSyntax Syntax);
77
78  /// Returns all compile commands in which the specified file was
79  /// compiled.
80  ///
81  /// FIXME: Currently FilePath must be an absolute path inside the
82  /// source directory which does not have symlinks resolved.
83  std::vector<CompileCommand>
84  getCompileCommands(StringRef FilePath) const override;
85
86  /// Returns the list of all files available in the compilation database.
87  ///
88  /// These are the 'file' entries of the JSON objects.
89  std::vector<std::string> getAllFiles() const override;
90
91  /// Returns all compile commands for all the files in the compilation
92  /// database.
93  std::vector<CompileCommand> getAllCompileCommands() const override;
94
95private:
96  /// Constructs a JSON compilation database on a memory buffer.
97  JSONCompilationDatabase(std::unique_ptr<llvm::MemoryBuffer> Database,
98                          JSONCommandLineSyntax Syntax)
99      : Database(std::move(Database)), Syntax(Syntax),
100        YAMLStream(this->Database->getBuffer(), SM) {}
101
102  /// Parses the database file and creates the index.
103  ///
104  /// Returns whether parsing succeeded. Sets ErrorMessage if parsing
105  /// failed.
106  bool parse(std::string &ErrorMessage);
107
108  // Tuple (directory, filename, commandline, output) where 'commandline'
109  // points to the corresponding scalar nodes in the YAML stream.
110  // If the command line contains a single argument, it is a shell-escaped
111  // command line.
112  // Otherwise, each entry in the command line vector is a literal
113  // argument to the compiler.
114  // The output field may be a nullptr.
115  using CompileCommandRef =
116      std::tuple<llvm::yaml::ScalarNode *, llvm::yaml::ScalarNode *,
117                 std::vector<llvm::yaml::ScalarNode *>,
118                 llvm::yaml::ScalarNode *>;
119
120  /// Converts the given array of CompileCommandRefs to CompileCommands.
121  void getCommands(ArrayRef<CompileCommandRef> CommandsRef,
122                   std::vector<CompileCommand> &Commands) const;
123
124  // Maps file paths to the compile command lines for that file.
125  llvm::StringMap<std::vector<CompileCommandRef>> IndexByFile;
126
127  /// All the compile commands in the order that they were provided in the
128  /// JSON stream.
129  std::vector<CompileCommandRef> AllCommands;
130
131  FileMatchTrie MatchTrie;
132
133  std::unique_ptr<llvm::MemoryBuffer> Database;
134  JSONCommandLineSyntax Syntax;
135  llvm::SourceMgr SM;
136  llvm::yaml::Stream YAMLStream;
137};
138
139} // namespace tooling
140} // namespace clang
141
142#endif // LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H
143