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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 
39 namespace clang {
40 namespace tooling {
41 
42 /// \brief Specifies the working directory and command of a compilation.
43 struct CompileCommand {
CompileCommandCompileCommand44   CompileCommand() {}
CompileCommandCompileCommand45   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.
71 class CompilationDatabase {
72 public:
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
138 class CompilationDatabasePlugin {
139 public:
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.
152 class FixedCompilationDatabase : public CompilationDatabase {
153 public:
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 
207 private:
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