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JSONCompilationDatabase.h
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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"
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 
32 namespace clang {
33 namespace 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.
62 public:
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 
95 private:
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
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
A trie to efficiently match against the entries of the compilation database in order of matching suff...
Definition: FileMatchTrie.h:56
const SourceManager & SM
Definition: Format.cpp:1568
Interface for compilation databases.
Dataflow Directional Tag Classes.
JSONCommandLineSyntax
A JSON based compilation database.