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CompilationDatabase.h
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1 //===- CompilationDatabase.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 // This file provides an interface and multiple implementations for
10 // CompilationDatabases.
11 //
12 // While C++ refactoring and analysis tools are not compilers, and thus
13 // don't run as part of the build system, they need the exact information
14 // of a build in order to be able to correctly understand the C++ code of
15 // the project. This information is provided via the CompilationDatabase
16 // interface.
17 //
18 // To create a CompilationDatabase from a build directory one can call
19 // CompilationDatabase::loadFromDirectory(), which deduces the correct
20 // compilation database from the root of the build tree.
21 //
22 // See the concrete subclasses of CompilationDatabase for currently supported
23 // formats.
24 //
25 //===----------------------------------------------------------------------===//
26 
27 #ifndef LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
28 #define LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
29 
30 #include "clang/Basic/LLVM.h"
31 #include "llvm/ADT/ArrayRef.h"
32 #include "llvm/ADT/StringRef.h"
33 #include "llvm/ADT/Twine.h"
34 #include "llvm/Support/VirtualFileSystem.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  /// If this compile command was guessed rather than read from an authoritative
64  /// source, a short human-readable explanation.
65  /// e.g. "inferred from foo/bar.h".
66  std::string Heuristic;
67 
68  friend bool operator==(const CompileCommand &LHS, const CompileCommand &RHS) {
69  return LHS.Directory == RHS.Directory && LHS.Filename == RHS.Filename &&
70  LHS.CommandLine == RHS.CommandLine && LHS.Output == RHS.Output &&
71  LHS.Heuristic == RHS.Heuristic;
72  }
73 
74  friend bool operator!=(const CompileCommand &LHS, const CompileCommand &RHS) {
75  return !(LHS == RHS);
76  }
77 };
78 
79 /// Interface for compilation databases.
80 ///
81 /// A compilation database allows the user to retrieve compile command lines
82 /// for the files in a project.
83 ///
84 /// Many implementations are enumerable, allowing all command lines to be
85 /// retrieved. These can be used to run clang tools over a subset of the files
86 /// in a project.
88 public:
89  virtual ~CompilationDatabase();
90 
91  /// Loads a compilation database from a build directory.
92  ///
93  /// Looks at the specified 'BuildDirectory' and creates a compilation database
94  /// that allows to query compile commands for source files in the
95  /// corresponding source tree.
96  ///
97  /// Returns NULL and sets ErrorMessage if we were not able to build up a
98  /// compilation database for the build directory.
99  ///
100  /// FIXME: Currently only supports JSON compilation databases, which
101  /// are named 'compile_commands.json' in the given directory. Extend this
102  /// for other build types (like ninja build files).
103  static std::unique_ptr<CompilationDatabase>
104  loadFromDirectory(StringRef BuildDirectory, std::string &ErrorMessage);
105 
106  /// Tries to detect a compilation database location and load it.
107  ///
108  /// Looks for a compilation database in all parent paths of file 'SourceFile'
109  /// by calling loadFromDirectory.
110  static std::unique_ptr<CompilationDatabase>
111  autoDetectFromSource(StringRef SourceFile, std::string &ErrorMessage);
112 
113  /// Tries to detect a compilation database location and load it.
114  ///
115  /// Looks for a compilation database in directory 'SourceDir' and all
116  /// its parent paths by calling loadFromDirectory.
117  static std::unique_ptr<CompilationDatabase>
118  autoDetectFromDirectory(StringRef SourceDir, std::string &ErrorMessage);
119 
120  /// Returns all compile commands in which the specified file was
121  /// compiled.
122  ///
123  /// This includes compile commands that span multiple source files.
124  /// For example, consider a project with the following compilations:
125  /// $ clang++ -o test a.cc b.cc t.cc
126  /// $ clang++ -o production a.cc b.cc -DPRODUCTION
127  /// A compilation database representing the project would return both command
128  /// lines for a.cc and b.cc and only the first command line for t.cc.
129  virtual std::vector<CompileCommand> getCompileCommands(
130  StringRef FilePath) const = 0;
131 
132  /// Returns the list of all files available in the compilation database.
133  ///
134  /// By default, returns nothing. Implementations should override this if they
135  /// can enumerate their source files.
136  virtual std::vector<std::string> getAllFiles() const { return {}; }
137 
138  /// Returns all compile commands for all the files in the compilation
139  /// database.
140  ///
141  /// FIXME: Add a layer in Tooling that provides an interface to run a tool
142  /// over all files in a compilation database. Not all build systems have the
143  /// ability to provide a feasible implementation for \c getAllCompileCommands.
144  ///
145  /// By default, this is implemented in terms of getAllFiles() and
146  /// getCompileCommands(). Subclasses may override this for efficiency.
147  virtual std::vector<CompileCommand> getAllCompileCommands() const;
148 };
149 
150 /// A compilation database that returns a single compile command line.
151 ///
152 /// Useful when we want a tool to behave more like a compiler invocation.
153 /// This compilation database is not enumerable: getAllFiles() returns {}.
155 public:
156  /// Creates a FixedCompilationDatabase from the arguments after "--".
157  ///
158  /// Parses the given command line for "--". If "--" is found, the rest of
159  /// the arguments will make up the command line in the returned
160  /// FixedCompilationDatabase.
161  /// The arguments after "--" must not include positional parameters or the
162  /// argv[0] of the tool. Those will be added by the FixedCompilationDatabase
163  /// when a CompileCommand is requested. The argv[0] of the returned command
164  /// line will be "clang-tool".
165  ///
166  /// Returns NULL in case "--" is not found.
167  ///
168  /// The argument list is meant to be compatible with normal llvm command line
169  /// parsing in main methods.
170  /// int main(int argc, char **argv) {
171  /// std::unique_ptr<FixedCompilationDatabase> Compilations(
172  /// FixedCompilationDatabase::loadFromCommandLine(argc, argv));
173  /// cl::ParseCommandLineOptions(argc, argv);
174  /// ...
175  /// }
176  ///
177  /// \param Argc The number of command line arguments - will be changed to
178  /// the number of arguments before "--", if "--" was found in the argument
179  /// list.
180  /// \param Argv Points to the command line arguments.
181  /// \param ErrorMsg Contains error text if the function returns null pointer.
182  /// \param Directory The base directory used in the FixedCompilationDatabase.
183  static std::unique_ptr<FixedCompilationDatabase> loadFromCommandLine(
184  int &Argc, const char *const *Argv, std::string &ErrorMsg,
185  Twine Directory = ".");
186 
187  /// Reads flags from the given file, one-per line.
188  /// Returns nullptr and sets ErrorMessage if we can't read the file.
189  static std::unique_ptr<FixedCompilationDatabase>
190  loadFromFile(StringRef Path, std::string &ErrorMsg);
191 
192  /// Constructs a compilation data base from a specified directory
193  /// and command line.
195 
196  /// Returns the given compile command.
197  ///
198  /// Will always return a vector with one entry that contains the directory
199  /// and command line specified at construction with "clang-tool" as argv[0]
200  /// and 'FilePath' as positional argument.
201  std::vector<CompileCommand>
202  getCompileCommands(StringRef FilePath) const override;
203 
204 private:
205  /// This is built up to contain a single entry vector to be returned from
206  /// getCompileCommands after adding the positional argument.
207  std::vector<CompileCommand> CompileCommands;
208 };
209 
210 /// Returns a wrapped CompilationDatabase that defers to the provided one,
211 /// but getCompileCommands() will infer commands for unknown files.
212 /// The return value of getAllFiles() or getAllCompileCommands() is unchanged.
213 /// See InterpolatingCompilationDatabase.cpp for details on heuristics.
214 std::unique_ptr<CompilationDatabase>
215  inferMissingCompileCommands(std::unique_ptr<CompilationDatabase>);
216 
217 /// Returns a wrapped CompilationDatabase that will add -target and -mode flags
218 /// to commandline when they can be deduced from argv[0] of commandline returned
219 /// by underlying database.
220 std::unique_ptr<CompilationDatabase>
221 inferTargetAndDriverMode(std::unique_ptr<CompilationDatabase> Base);
222 
223 /// Returns a wrapped CompilationDatabase that will expand all rsp(response)
224 /// files on commandline returned by underlying database.
225 std::unique_ptr<CompilationDatabase>
226 expandResponseFiles(std::unique_ptr<CompilationDatabase> Base,
228 
229 } // namespace tooling
230 } // namespace clang
231 
232 #endif // LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
std::string Heuristic
If this compile command was guessed rather than read from an authoritative source, a short human-readable explanation.
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.
std::unique_ptr< CompilationDatabase > inferTargetAndDriverMode(std::unique_ptr< CompilationDatabase > Base)
Returns a wrapped CompilationDatabase that will add -target and -mode flags to commandline when they ...
Definition: Format.h:2679
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...
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 ...
std::unique_ptr< CompilationDatabase > expandResponseFiles(std::unique_ptr< CompilationDatabase > Base, llvm::IntrusiveRefCntPtr< llvm::vfs::FileSystem > FS)
Returns a wrapped CompilationDatabase that will expand all rsp(response) files on commandline returne...
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.