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CompilationDatabase.h
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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_COMPILATIONDATABASE_H
29 #define LLVM_CLANG_TOOLING_COMPILATIONDATABASE_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 <utility>
38 #include <vector>
39 
40 namespace clang {
41 namespace tooling {
42 
43 /// Specifies the working directory and command of a compilation.
45  CompileCommand() = default;
47  std::vector<std::string> CommandLine, Twine Output)
48  : Directory(Directory.str()), Filename(Filename.str()),
49  CommandLine(std::move(CommandLine)), Output(Output.str()){}
50 
51  /// The working directory the command was executed from.
52  std::string Directory;
53 
54  /// The source file associated with the command.
55  std::string Filename;
56 
57  /// The command line that was executed.
58  std::vector<std::string> CommandLine;
59 
60  /// The output file associated with the command.
61  std::string Output;
62 
63  friend bool operator==(const CompileCommand &LHS, const CompileCommand &RHS) {
64  return LHS.Directory == RHS.Directory && LHS.Filename == RHS.Filename &&
65  LHS.CommandLine == RHS.CommandLine && LHS.Output == RHS.Output;
66  }
67 
68  friend bool operator!=(const CompileCommand &LHS, const CompileCommand &RHS) {
69  return !(LHS == RHS);
70  }
71 };
72 
73 /// Interface for compilation databases.
74 ///
75 /// A compilation database allows the user to retrieve compile command lines
76 /// for the files in a project.
77 ///
78 /// Many implementations are enumerable, allowing all command lines to be
79 /// retrieved. These can be used to run clang tools over a subset of the files
80 /// in a project.
82 public:
83  virtual ~CompilationDatabase();
84 
85  /// Loads a compilation database from a build directory.
86  ///
87  /// Looks at the specified 'BuildDirectory' and creates a compilation database
88  /// that allows to query compile commands for source files in the
89  /// corresponding source tree.
90  ///
91  /// Returns NULL and sets ErrorMessage if we were not able to build up a
92  /// compilation database for the build directory.
93  ///
94  /// FIXME: Currently only supports JSON compilation databases, which
95  /// are named 'compile_commands.json' in the given directory. Extend this
96  /// for other build types (like ninja build files).
97  static std::unique_ptr<CompilationDatabase>
98  loadFromDirectory(StringRef BuildDirectory, std::string &ErrorMessage);
99 
100  /// Tries to detect a compilation database location and load it.
101  ///
102  /// Looks for a compilation database in all parent paths of file 'SourceFile'
103  /// by calling loadFromDirectory.
104  static std::unique_ptr<CompilationDatabase>
105  autoDetectFromSource(StringRef SourceFile, std::string &ErrorMessage);
106 
107  /// Tries to detect a compilation database location and load it.
108  ///
109  /// Looks for a compilation database in directory 'SourceDir' and all
110  /// its parent paths by calling loadFromDirectory.
111  static std::unique_ptr<CompilationDatabase>
112  autoDetectFromDirectory(StringRef SourceDir, std::string &ErrorMessage);
113 
114  /// Returns all compile commands in which the specified file was
115  /// compiled.
116  ///
117  /// This includes compile commands that span multiple source files.
118  /// For example, consider a project with the following compilations:
119  /// $ clang++ -o test a.cc b.cc t.cc
120  /// $ clang++ -o production a.cc b.cc -DPRODUCTION
121  /// A compilation database representing the project would return both command
122  /// lines for a.cc and b.cc and only the first command line for t.cc.
123  virtual std::vector<CompileCommand> getCompileCommands(
124  StringRef FilePath) const = 0;
125 
126  /// Returns the list of all files available in the compilation database.
127  ///
128  /// By default, returns nothing. Implementations should override this if they
129  /// can enumerate their source files.
130  virtual std::vector<std::string> getAllFiles() const { return {}; }
131 
132  /// Returns all compile commands for all the files in the compilation
133  /// database.
134  ///
135  /// FIXME: Add a layer in Tooling that provides an interface to run a tool
136  /// over all files in a compilation database. Not all build systems have the
137  /// ability to provide a feasible implementation for \c getAllCompileCommands.
138  ///
139  /// By default, this is implemented in terms of getAllFiles() and
140  /// getCompileCommands(). Subclasses may override this for efficiency.
141  virtual std::vector<CompileCommand> getAllCompileCommands() const;
142 };
143 
144 /// A compilation database that returns a single compile command line.
145 ///
146 /// Useful when we want a tool to behave more like a compiler invocation.
147 /// This compilation database is not enumerable: getAllFiles() returns {}.
149 public:
150  /// Creates a FixedCompilationDatabase from the arguments after "--".
151  ///
152  /// Parses the given command line for "--". If "--" is found, the rest of
153  /// the arguments will make up the command line in the returned
154  /// FixedCompilationDatabase.
155  /// The arguments after "--" must not include positional parameters or the
156  /// argv[0] of the tool. Those will be added by the FixedCompilationDatabase
157  /// when a CompileCommand is requested. The argv[0] of the returned command
158  /// line will be "clang-tool".
159  ///
160  /// Returns NULL in case "--" is not found.
161  ///
162  /// The argument list is meant to be compatible with normal llvm command line
163  /// parsing in main methods.
164  /// int main(int argc, char **argv) {
165  /// std::unique_ptr<FixedCompilationDatabase> Compilations(
166  /// FixedCompilationDatabase::loadFromCommandLine(argc, argv));
167  /// cl::ParseCommandLineOptions(argc, argv);
168  /// ...
169  /// }
170  ///
171  /// \param Argc The number of command line arguments - will be changed to
172  /// the number of arguments before "--", if "--" was found in the argument
173  /// list.
174  /// \param Argv Points to the command line arguments.
175  /// \param ErrorMsg Contains error text if the function returns null pointer.
176  /// \param Directory The base directory used in the FixedCompilationDatabase.
177  static std::unique_ptr<FixedCompilationDatabase> loadFromCommandLine(
178  int &Argc, const char *const *Argv, std::string &ErrorMsg,
179  Twine Directory = ".");
180 
181  /// Reads flags from the given file, one-per line.
182  /// Returns nullptr and sets ErrorMessage if we can't read the file.
183  static std::unique_ptr<FixedCompilationDatabase>
184  loadFromFile(StringRef Path, std::string &ErrorMsg);
185 
186  /// Constructs a compilation data base from a specified directory
187  /// and command line.
189 
190  /// Returns the given compile command.
191  ///
192  /// Will always return a vector with one entry that contains the directory
193  /// and command line specified at construction with "clang-tool" as argv[0]
194  /// and 'FilePath' as positional argument.
195  std::vector<CompileCommand>
196  getCompileCommands(StringRef FilePath) const override;
197 
198 private:
199  /// This is built up to contain a single entry vector to be returned from
200  /// getCompileCommands after adding the positional argument.
201  std::vector<CompileCommand> CompileCommands;
202 };
203 
204 /// Returns a wrapped CompilationDatabase that defers to the provided one,
205 /// but getCompileCommands() will infer commands for unknown files.
206 /// The return value of getAllFiles() or getAllCompileCommands() is unchanged.
207 /// See InterpolatingCompilationDatabase.cpp for details on heuristics.
208 std::unique_ptr<CompilationDatabase>
209  inferMissingCompileCommands(std::unique_ptr<CompilationDatabase>);
210 
211 } // namespace tooling
212 } // namespace clang
213 
214 #endif // LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
std::string Output
The output file associated with the command.
virtual std::vector< std::string > getAllFiles() const
Returns the list of all files available in the compilation database.
Definition: Format.h:2072
std::string Directory
The working directory the command was executed from.
friend bool operator==(const CompileCommand &LHS, const CompileCommand &RHS)
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
return Out str()
std::string Filename
The source file associated with the command.
Interface for compilation databases.
Specifies the working directory and command of a compilation.
std::unique_ptr< CompilationDatabase > inferMissingCompileCommands(std::unique_ptr< CompilationDatabase >)
Returns a wrapped CompilationDatabase that defers to the provided one, but getCompileCommands() will ...
Dataflow Directional Tag Classes.
friend bool operator!=(const CompileCommand &LHS, const CompileCommand &RHS)
std::vector< std::string > CommandLine
The command line that was executed.
CompileCommand(Twine Directory, Twine Filename, std::vector< std::string > CommandLine, Twine Output)
A compilation database that returns a single compile command line.