1//===--- JSONCompilationDatabase.cpp - ------------------------------------===//
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 contains the implementation of the JSONCompilationDatabase.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Tooling/JSONCompilationDatabase.h"
15#include "clang/Tooling/CompilationDatabase.h"
16#include "clang/Tooling/CompilationDatabasePluginRegistry.h"
17#include "clang/Tooling/Tooling.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/Support/Path.h"
20#include <system_error>
21
22namespace clang {
23namespace tooling {
24
25namespace {
26
27/// \brief A parser for escaped strings of command line arguments.
28///
29/// Assumes \-escaping for quoted arguments (see the documentation of
30/// unescapeCommandLine(...)).
31class CommandLineArgumentParser {
32 public:
33  CommandLineArgumentParser(StringRef CommandLine)
34      : Input(CommandLine), Position(Input.begin()-1) {}
35
36  std::vector<std::string> parse() {
37    bool HasMoreInput = true;
38    while (HasMoreInput && nextNonWhitespace()) {
39      std::string Argument;
40      HasMoreInput = parseStringInto(Argument);
41      CommandLine.push_back(Argument);
42    }
43    return CommandLine;
44  }
45
46 private:
47  // All private methods return true if there is more input available.
48
49  bool parseStringInto(std::string &String) {
50    do {
51      if (*Position == '"') {
52        if (!parseDoubleQuotedStringInto(String)) return false;
53      } else if (*Position == '\'') {
54        if (!parseSingleQuotedStringInto(String)) return false;
55      } else {
56        if (!parseFreeStringInto(String)) return false;
57      }
58    } while (*Position != ' ');
59    return true;
60  }
61
62  bool parseDoubleQuotedStringInto(std::string &String) {
63    if (!next()) return false;
64    while (*Position != '"') {
65      if (!skipEscapeCharacter()) return false;
66      String.push_back(*Position);
67      if (!next()) return false;
68    }
69    return next();
70  }
71
72  bool parseSingleQuotedStringInto(std::string &String) {
73    if (!next()) return false;
74    while (*Position != '\'') {
75      String.push_back(*Position);
76      if (!next()) return false;
77    }
78    return next();
79  }
80
81  bool parseFreeStringInto(std::string &String) {
82    do {
83      if (!skipEscapeCharacter()) return false;
84      String.push_back(*Position);
85      if (!next()) return false;
86    } while (*Position != ' ' && *Position != '"' && *Position != '\'');
87    return true;
88  }
89
90  bool skipEscapeCharacter() {
91    if (*Position == '\\') {
92      return next();
93    }
94    return true;
95  }
96
97  bool nextNonWhitespace() {
98    do {
99      if (!next()) return false;
100    } while (*Position == ' ');
101    return true;
102  }
103
104  bool next() {
105    ++Position;
106    return Position != Input.end();
107  }
108
109  const StringRef Input;
110  StringRef::iterator Position;
111  std::vector<std::string> CommandLine;
112};
113
114std::vector<std::string> unescapeCommandLine(
115    StringRef EscapedCommandLine) {
116  CommandLineArgumentParser parser(EscapedCommandLine);
117  return parser.parse();
118}
119
120class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {
121  CompilationDatabase *loadFromDirectory(StringRef Directory,
122                                         std::string &ErrorMessage) override {
123    SmallString<1024> JSONDatabasePath(Directory);
124    llvm::sys::path::append(JSONDatabasePath, "compile_commands.json");
125    std::unique_ptr<CompilationDatabase> Database(
126        JSONCompilationDatabase::loadFromFile(JSONDatabasePath, ErrorMessage));
127    if (!Database)
128      return nullptr;
129    return Database.release();
130  }
131};
132
133} // end namespace
134
135// Register the JSONCompilationDatabasePlugin with the
136// CompilationDatabasePluginRegistry using this statically initialized variable.
137static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin>
138X("json-compilation-database", "Reads JSON formatted compilation databases");
139
140// This anchor is used to force the linker to link in the generated object file
141// and thus register the JSONCompilationDatabasePlugin.
142volatile int JSONAnchorSource = 0;
143
144JSONCompilationDatabase *
145JSONCompilationDatabase::loadFromFile(StringRef FilePath,
146                                      std::string &ErrorMessage) {
147  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> DatabaseBuffer =
148      llvm::MemoryBuffer::getFile(FilePath);
149  if (std::error_code Result = DatabaseBuffer.getError()) {
150    ErrorMessage = "Error while opening JSON database: " + Result.message();
151    return nullptr;
152  }
153  std::unique_ptr<JSONCompilationDatabase> Database(
154      new JSONCompilationDatabase(DatabaseBuffer->release()));
155  if (!Database->parse(ErrorMessage))
156    return nullptr;
157  return Database.release();
158}
159
160JSONCompilationDatabase *
161JSONCompilationDatabase::loadFromBuffer(StringRef DatabaseString,
162                                        std::string &ErrorMessage) {
163  std::unique_ptr<llvm::MemoryBuffer> DatabaseBuffer(
164      llvm::MemoryBuffer::getMemBuffer(DatabaseString));
165  std::unique_ptr<JSONCompilationDatabase> Database(
166      new JSONCompilationDatabase(DatabaseBuffer.release()));
167  if (!Database->parse(ErrorMessage))
168    return nullptr;
169  return Database.release();
170}
171
172std::vector<CompileCommand>
173JSONCompilationDatabase::getCompileCommands(StringRef FilePath) const {
174  SmallString<128> NativeFilePath;
175  llvm::sys::path::native(FilePath, NativeFilePath);
176
177  std::string Error;
178  llvm::raw_string_ostream ES(Error);
179  StringRef Match = MatchTrie.findEquivalent(NativeFilePath.str(), ES);
180  if (Match.empty())
181    return std::vector<CompileCommand>();
182  llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
183    CommandsRefI = IndexByFile.find(Match);
184  if (CommandsRefI == IndexByFile.end())
185    return std::vector<CompileCommand>();
186  std::vector<CompileCommand> Commands;
187  getCommands(CommandsRefI->getValue(), Commands);
188  return Commands;
189}
190
191std::vector<std::string>
192JSONCompilationDatabase::getAllFiles() const {
193  std::vector<std::string> Result;
194
195  llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
196    CommandsRefI = IndexByFile.begin();
197  const llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
198    CommandsRefEnd = IndexByFile.end();
199  for (; CommandsRefI != CommandsRefEnd; ++CommandsRefI) {
200    Result.push_back(CommandsRefI->first().str());
201  }
202
203  return Result;
204}
205
206std::vector<CompileCommand>
207JSONCompilationDatabase::getAllCompileCommands() const {
208  std::vector<CompileCommand> Commands;
209  for (llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
210        CommandsRefI = IndexByFile.begin(), CommandsRefEnd = IndexByFile.end();
211      CommandsRefI != CommandsRefEnd; ++CommandsRefI) {
212    getCommands(CommandsRefI->getValue(), Commands);
213  }
214  return Commands;
215}
216
217void JSONCompilationDatabase::getCommands(
218                                  ArrayRef<CompileCommandRef> CommandsRef,
219                                  std::vector<CompileCommand> &Commands) const {
220  for (int I = 0, E = CommandsRef.size(); I != E; ++I) {
221    SmallString<8> DirectoryStorage;
222    SmallString<1024> CommandStorage;
223    Commands.push_back(CompileCommand(
224      // FIXME: Escape correctly:
225      CommandsRef[I].first->getValue(DirectoryStorage),
226      unescapeCommandLine(CommandsRef[I].second->getValue(CommandStorage))));
227  }
228}
229
230bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
231  llvm::yaml::document_iterator I = YAMLStream.begin();
232  if (I == YAMLStream.end()) {
233    ErrorMessage = "Error while parsing YAML.";
234    return false;
235  }
236  llvm::yaml::Node *Root = I->getRoot();
237  if (!Root) {
238    ErrorMessage = "Error while parsing YAML.";
239    return false;
240  }
241  llvm::yaml::SequenceNode *Array = dyn_cast<llvm::yaml::SequenceNode>(Root);
242  if (!Array) {
243    ErrorMessage = "Expected array.";
244    return false;
245  }
246  for (llvm::yaml::SequenceNode::iterator AI = Array->begin(),
247                                          AE = Array->end();
248       AI != AE; ++AI) {
249    llvm::yaml::MappingNode *Object = dyn_cast<llvm::yaml::MappingNode>(&*AI);
250    if (!Object) {
251      ErrorMessage = "Expected object.";
252      return false;
253    }
254    llvm::yaml::ScalarNode *Directory = nullptr;
255    llvm::yaml::ScalarNode *Command = nullptr;
256    llvm::yaml::ScalarNode *File = nullptr;
257    for (llvm::yaml::MappingNode::iterator KVI = Object->begin(),
258                                           KVE = Object->end();
259         KVI != KVE; ++KVI) {
260      llvm::yaml::Node *Value = (*KVI).getValue();
261      if (!Value) {
262        ErrorMessage = "Expected value.";
263        return false;
264      }
265      llvm::yaml::ScalarNode *ValueString =
266          dyn_cast<llvm::yaml::ScalarNode>(Value);
267      if (!ValueString) {
268        ErrorMessage = "Expected string as value.";
269        return false;
270      }
271      llvm::yaml::ScalarNode *KeyString =
272          dyn_cast<llvm::yaml::ScalarNode>((*KVI).getKey());
273      if (!KeyString) {
274        ErrorMessage = "Expected strings as key.";
275        return false;
276      }
277      SmallString<8> KeyStorage;
278      if (KeyString->getValue(KeyStorage) == "directory") {
279        Directory = ValueString;
280      } else if (KeyString->getValue(KeyStorage) == "command") {
281        Command = ValueString;
282      } else if (KeyString->getValue(KeyStorage) == "file") {
283        File = ValueString;
284      } else {
285        ErrorMessage = ("Unknown key: \"" +
286                        KeyString->getRawValue() + "\"").str();
287        return false;
288      }
289    }
290    if (!File) {
291      ErrorMessage = "Missing key: \"file\".";
292      return false;
293    }
294    if (!Command) {
295      ErrorMessage = "Missing key: \"command\".";
296      return false;
297    }
298    if (!Directory) {
299      ErrorMessage = "Missing key: \"directory\".";
300      return false;
301    }
302    SmallString<8> FileStorage;
303    StringRef FileName = File->getValue(FileStorage);
304    SmallString<128> NativeFilePath;
305    if (llvm::sys::path::is_relative(FileName)) {
306      SmallString<8> DirectoryStorage;
307      SmallString<128> AbsolutePath(
308          Directory->getValue(DirectoryStorage));
309      llvm::sys::path::append(AbsolutePath, FileName);
310      llvm::sys::path::native(AbsolutePath.str(), NativeFilePath);
311    } else {
312      llvm::sys::path::native(FileName, NativeFilePath);
313    }
314    IndexByFile[NativeFilePath].push_back(
315        CompileCommandRef(Directory, Command));
316    MatchTrie.insert(NativeFilePath.str());
317  }
318  return true;
319}
320
321} // end namespace tooling
322} // end namespace clang
323