1//===--- CompilationDatabase.h - --------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file provides an interface and multiple implementations for
11//  CompilationDatabases.
12//
13//  While C++ refactoring and analysis tools are not compilers, and thus
14//  don't run as part of the build system, they need the exact information
15//  of a build in order to be able to correctly understand the C++ code of
16//  the project. This information is provided via the CompilationDatabase
17//  interface.
18//
19//  To create a CompilationDatabase from a build directory one can call
20//  CompilationDatabase::loadFromDirectory(), which deduces the correct
21//  compilation database from the root of the build tree.
22//
23//  See the concrete subclasses of CompilationDatabase for currently supported
24//  formats.
25//
26//===----------------------------------------------------------------------===//
27
28#ifndef LLVM_CLANG_TOOLING_COMPILATION_DATABASE_H
29#define LLVM_CLANG_TOOLING_COMPILATION_DATABASE_H
30
31#include "clang/Basic/LLVM.h"
32#include "llvm/ADT/ArrayRef.h"
33#include "llvm/ADT/StringRef.h"
34#include "llvm/ADT/Twine.h"
35#include <memory>
36#include <string>
37#include <vector>
38
39namespace clang {
40namespace tooling {
41
42/// \brief Specifies the working directory and command of a compilation.
43struct CompileCommand {
44  CompileCommand() {}
45  CompileCommand(Twine Directory, std::vector<std::string> CommandLine)
46      : Directory(Directory.str()), CommandLine(std::move(CommandLine)) {}
47
48  /// \brief The working directory the command was executed from.
49  std::string Directory;
50
51  /// \brief The command line that was executed.
52  std::vector<std::string> CommandLine;
53
54  /// \brief An optional mapping from each file's path to its content for all
55  /// files needed for the compilation that are not available via the file
56  /// system.
57  ///
58  /// Note that a tool implementation is required to fall back to the file
59  /// system if a source file is not provided in the mapped sources, as
60  /// compilation databases will usually not provide all files in mapped sources
61  /// for performance reasons.
62  std::vector<std::pair<std::string, std::string> > MappedSources;
63};
64
65/// \brief Interface for compilation databases.
66///
67/// A compilation database allows the user to retrieve all compile command lines
68/// that a specified file is compiled with in a project.
69/// The retrieved compile command lines can be used to run clang tools over
70/// a subset of the files in a project.
71class CompilationDatabase {
72public:
73  virtual ~CompilationDatabase();
74
75  /// \brief Loads a compilation database from a build directory.
76  ///
77  /// Looks at the specified 'BuildDirectory' and creates a compilation database
78  /// that allows to query compile commands for source files in the
79  /// corresponding source tree.
80  ///
81  /// Returns NULL and sets ErrorMessage if we were not able to build up a
82  /// compilation database for the build directory.
83  ///
84  /// FIXME: Currently only supports JSON compilation databases, which
85  /// are named 'compile_commands.json' in the given directory. Extend this
86  /// for other build types (like ninja build files).
87  static CompilationDatabase *loadFromDirectory(StringRef BuildDirectory,
88                                                std::string &ErrorMessage);
89
90  /// \brief Tries to detect a compilation database location and load it.
91  ///
92  /// Looks for a compilation database in all parent paths of file 'SourceFile'
93  /// by calling loadFromDirectory.
94  static CompilationDatabase *autoDetectFromSource(StringRef SourceFile,
95                                                   std::string &ErrorMessage);
96
97  /// \brief Tries to detect a compilation database location and load it.
98  ///
99  /// Looks for a compilation database in directory 'SourceDir' and all
100  /// its parent paths by calling loadFromDirectory.
101  static CompilationDatabase *autoDetectFromDirectory(StringRef SourceDir,
102                                                      std::string &ErrorMessage);
103
104  /// \brief Returns all compile commands in which the specified file was
105  /// compiled.
106  ///
107  /// This includes compile comamnds that span multiple source files.
108  /// For example, consider a project with the following compilations:
109  /// $ clang++ -o test a.cc b.cc t.cc
110  /// $ clang++ -o production a.cc b.cc -DPRODUCTION
111  /// A compilation database representing the project would return both command
112  /// lines for a.cc and b.cc and only the first command line for t.cc.
113  virtual std::vector<CompileCommand> getCompileCommands(
114    StringRef FilePath) const = 0;
115
116  /// \brief Returns the list of all files available in the compilation database.
117  virtual std::vector<std::string> getAllFiles() const = 0;
118
119  /// \brief Returns all compile commands for all the files in the compilation
120  /// database.
121  ///
122  /// FIXME: Add a layer in Tooling that provides an interface to run a tool
123  /// over all files in a compilation database. Not all build systems have the
124  /// ability to provide a feasible implementation for \c getAllCompileCommands.
125  virtual std::vector<CompileCommand> getAllCompileCommands() const = 0;
126};
127
128/// \brief Interface for compilation database plugins.
129///
130/// A compilation database plugin allows the user to register custom compilation
131/// databases that are picked up as compilation database if the corresponding
132/// library is linked in. To register a plugin, declare a static variable like:
133///
134/// \code
135/// static CompilationDatabasePluginRegistry::Add<MyDatabasePlugin>
136/// X("my-compilation-database", "Reads my own compilation database");
137/// \endcode
138class CompilationDatabasePlugin {
139public:
140  virtual ~CompilationDatabasePlugin();
141
142  /// \brief Loads a compilation database from a build directory.
143  ///
144  /// \see CompilationDatabase::loadFromDirectory().
145  virtual CompilationDatabase *loadFromDirectory(StringRef Directory,
146                                                 std::string &ErrorMessage) = 0;
147};
148
149/// \brief A compilation database that returns a single compile command line.
150///
151/// Useful when we want a tool to behave more like a compiler invocation.
152class FixedCompilationDatabase : public CompilationDatabase {
153public:
154  /// \brief Creates a FixedCompilationDatabase from the arguments after "--".
155  ///
156  /// Parses the given command line for "--". If "--" is found, the rest of
157  /// the arguments will make up the command line in the returned
158  /// FixedCompilationDatabase.
159  /// The arguments after "--" must not include positional parameters or the
160  /// argv[0] of the tool. Those will be added by the FixedCompilationDatabase
161  /// when a CompileCommand is requested. The argv[0] of the returned command
162  /// line will be "clang-tool".
163  ///
164  /// Returns NULL in case "--" is not found.
165  ///
166  /// The argument list is meant to be compatible with normal llvm command line
167  /// parsing in main methods.
168  /// int main(int argc, char **argv) {
169  ///   std::unique_ptr<FixedCompilationDatabase> Compilations(
170  ///     FixedCompilationDatabase::loadFromCommandLine(argc, argv));
171  ///   cl::ParseCommandLineOptions(argc, argv);
172  ///   ...
173  /// }
174  ///
175  /// \param Argc The number of command line arguments - will be changed to
176  /// the number of arguments before "--", if "--" was found in the argument
177  /// list.
178  /// \param Argv Points to the command line arguments.
179  /// \param Directory The base directory used in the FixedCompilationDatabase.
180  static FixedCompilationDatabase *loadFromCommandLine(int &Argc,
181                                                       const char **Argv,
182                                                       Twine Directory = ".");
183
184  /// \brief Constructs a compilation data base from a specified directory
185  /// and command line.
186  FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine);
187
188  /// \brief Returns the given compile command.
189  ///
190  /// Will always return a vector with one entry that contains the directory
191  /// and command line specified at construction with "clang-tool" as argv[0]
192  /// and 'FilePath' as positional argument.
193  std::vector<CompileCommand>
194  getCompileCommands(StringRef FilePath) const override;
195
196  /// \brief Returns the list of all files available in the compilation database.
197  ///
198  /// Note: This is always an empty list for the fixed compilation database.
199  std::vector<std::string> getAllFiles() const override;
200
201  /// \brief Returns all compile commands for all the files in the compilation
202  /// database.
203  ///
204  /// Note: This is always an empty list for the fixed compilation database.
205  std::vector<CompileCommand> getAllCompileCommands() const override;
206
207private:
208  /// This is built up to contain a single entry vector to be returned from
209  /// getCompileCommands after adding the positional argument.
210  std::vector<CompileCommand> CompileCommands;
211};
212
213} // end namespace tooling
214} // end namespace clang
215
216#endif // LLVM_CLANG_TOOLING_COMPILATION_DATABASE_H
217