clang/Tooling/JSONCompilationDatabase.h

0001 //===- JSONCompilationDatabase.h --------------------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009 //  The JSONCompilationDatabase finds compilation databases supplied as a file
0010 //  'compile_commands.json'.
0011 //
0012 //===----------------------------------------------------------------------===//
0013
0014 #ifndef LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H
0015 #define LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H
0016
0017 #include "clang/Basic/LLVM.h"
0018 #include "clang/Tooling/CompilationDatabase.h"
0019 #include "clang/Tooling/FileMatchTrie.h"
0020 #include "llvm/ADT/ArrayRef.h"
0021 #include "llvm/ADT/StringMap.h"
0022 #include "llvm/ADT/StringRef.h"
0023 #include "llvm/Support/MemoryBuffer.h"
0024 #include "llvm/Support/SourceMgr.h"
0025 #include "llvm/Support/YAMLParser.h"
0026 #include <memory>
0027 #include <string>
0028 #include <tuple>
0029 #include <utility>
0030 #include <vector>
0031
0032 namespace clang {
0033 namespace tooling {
0034
0035 /// A JSON based compilation database.
0036 ///
0037 /// JSON compilation database files must contain a list of JSON objects which
0038 /// provide the command lines in the attributes 'directory', 'command',
0039 /// 'arguments' and 'file':
0040 /// [
0041 ///   { "directory": "<working directory of the compile>",
0042 ///     "command": "<compile command line>",
0043 ///     "file": "<path to source file>"
0044 ///   },
0045 ///   { "directory": "<working directory of the compile>",
0046 ///     "arguments": ["<raw>", "<command>" "<line>" "<parameters>"],
0047 ///     "file": "<path to source file>"
0048 ///   },
0049 ///   ...
0050 /// ]
0051 /// Each object entry defines one compile action. The specified file is
0052 /// considered to be the main source file for the translation unit.
0053 ///
0054 /// 'command' is a full command line that will be unescaped.
0055 ///
0056 /// 'arguments' is a list of command line arguments that will not be unescaped.
0057 ///
0058 /// JSON compilation databases can for example be generated in CMake projects
0059 /// by setting the flag -DCMAKE_EXPORT_COMPILE_COMMANDS.
0060 enum class JSONCommandLineSyntax { Windows, Gnu, AutoDetect };
0061 class JSONCompilationDatabase : public CompilationDatabase {
0062 public:
0063   /// Loads a JSON compilation database from the specified file.
0064   ///
0065   /// Returns NULL and sets ErrorMessage if the database could not be
0066   /// loaded from the given file.
0067   static std::unique_ptr<JSONCompilationDatabase>
0068   loadFromFile(StringRef FilePath, std::string &ErrorMessage,
0069                JSONCommandLineSyntax Syntax);
0070
0071   /// Loads a JSON compilation database from a data buffer.
0072   ///
0073   /// Returns NULL and sets ErrorMessage if the database could not be loaded.
0074   static std::unique_ptr<JSONCompilationDatabase>
0075   loadFromBuffer(StringRef DatabaseString, std::string &ErrorMessage,
0076                  JSONCommandLineSyntax Syntax);
0077
0078   /// Returns all compile commands in which the specified file was
0079   /// compiled.
0080   ///
0081   /// FIXME: Currently FilePath must be an absolute path inside the
0082   /// source directory which does not have symlinks resolved.
0083   std::vector<CompileCommand>
0084   getCompileCommands(StringRef FilePath) const override;
0085
0086   /// Returns the list of all files available in the compilation database.
0087   ///
0088   /// These are the 'file' entries of the JSON objects.
0089   std::vector<std::string> getAllFiles() const override;
0090
0091   /// Returns all compile commands for all the files in the compilation
0092   /// database.
0093   std::vector<CompileCommand> getAllCompileCommands() const override;
0094
0095 private:
0096   /// Constructs a JSON compilation database on a memory buffer.
0097   JSONCompilationDatabase(std::unique_ptr<llvm::MemoryBuffer> Database,
0098                           JSONCommandLineSyntax Syntax)
0099       : Database(std::move(Database)), Syntax(Syntax),
0100         YAMLStream(this->Database->getBuffer(), SM) {}
0101
0102   /// Parses the database file and creates the index.
0103   ///
0104   /// Returns whether parsing succeeded. Sets ErrorMessage if parsing
0105   /// failed.
0106   bool parse(std::string &ErrorMessage);
0107
0108   // Tuple (directory, filename, commandline, output) where 'commandline'
0109   // points to the corresponding scalar nodes in the YAML stream.
0110   // If the command line contains a single argument, it is a shell-escaped
0111   // command line.
0112   // Otherwise, each entry in the command line vector is a literal
0113   // argument to the compiler.
0114   // The output field may be a nullptr.
0115   using CompileCommandRef =
0116       std::tuple<llvm::yaml::ScalarNode *, llvm::yaml::ScalarNode *,
0117                  std::vector<llvm::yaml::ScalarNode *>,
0118                  llvm::yaml::ScalarNode *>;
0119
0120   /// Converts the given array of CompileCommandRefs to CompileCommands.
0121   void getCommands(ArrayRef<CompileCommandRef> CommandsRef,
0122                    std::vector<CompileCommand> &Commands) const;
0123
0124   // Maps file paths to the compile command lines for that file.
0125   llvm::StringMap<std::vector<CompileCommandRef>> IndexByFile;
0126
0127   /// All the compile commands in the order that they were provided in the
0128   /// JSON stream.
0129   std::vector<CompileCommandRef> AllCommands;
0130
0131   FileMatchTrie MatchTrie;
0132
0133   std::unique_ptr<llvm::MemoryBuffer> Database;
0134   JSONCommandLineSyntax Syntax;
0135   llvm::SourceMgr SM;
0136   llvm::yaml::Stream YAMLStream;
0137 };
0138
0139 } // namespace tooling
0140 } // namespace clang
0141
0142 #endif // LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H