xref: /llvm-project/clang/lib/Tooling/JSONCompilationDatabase.cpp (revision 251ad5e06b2002ae8e0a0c1b2c03f89356fb55f5)
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 
16 #include "clang/Tooling/CompilationDatabase.h"
17 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
18 #include "clang/Tooling/Tooling.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/Support/Path.h"
21 #include "llvm/Support/system_error.h"
22 
23 namespace clang {
24 namespace tooling {
25 
26 namespace {
27 
28 /// \brief A parser for escaped strings of command line arguments.
29 ///
30 /// Assumes \-escaping for quoted arguments (see the documentation of
31 /// unescapeCommandLine(...)).
32 class CommandLineArgumentParser {
33  public:
34   CommandLineArgumentParser(StringRef CommandLine)
35       : Input(CommandLine), Position(Input.begin()-1) {}
36 
37   std::vector<std::string> parse() {
38     bool HasMoreInput = true;
39     while (HasMoreInput && nextNonWhitespace()) {
40       std::string Argument;
41       HasMoreInput = parseStringInto(Argument);
42       CommandLine.push_back(Argument);
43     }
44     return CommandLine;
45   }
46 
47  private:
48   // All private methods return true if there is more input available.
49 
50   bool parseStringInto(std::string &String) {
51     do {
52       if (*Position == '"') {
53         if (!parseQuotedStringInto(String)) return false;
54       } else {
55         if (!parseFreeStringInto(String)) return false;
56       }
57     } while (*Position != ' ');
58     return true;
59   }
60 
61   bool parseQuotedStringInto(std::string &String) {
62     if (!next()) return false;
63     while (*Position != '"') {
64       if (!skipEscapeCharacter()) return false;
65       String.push_back(*Position);
66       if (!next()) return false;
67     }
68     return next();
69   }
70 
71   bool parseFreeStringInto(std::string &String) {
72     do {
73       if (!skipEscapeCharacter()) return false;
74       String.push_back(*Position);
75       if (!next()) return false;
76     } while (*Position != ' ' && *Position != '"');
77     return true;
78   }
79 
80   bool skipEscapeCharacter() {
81     if (*Position == '\\') {
82       return next();
83     }
84     return true;
85   }
86 
87   bool nextNonWhitespace() {
88     do {
89       if (!next()) return false;
90     } while (*Position == ' ');
91     return true;
92   }
93 
94   bool next() {
95     ++Position;
96     return Position != Input.end();
97   }
98 
99   const StringRef Input;
100   StringRef::iterator Position;
101   std::vector<std::string> CommandLine;
102 };
103 
104 std::vector<std::string> unescapeCommandLine(
105     StringRef EscapedCommandLine) {
106   CommandLineArgumentParser parser(EscapedCommandLine);
107   return parser.parse();
108 }
109 
110 } // end namespace
111 
112 class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {
113   virtual CompilationDatabase *loadFromDirectory(
114       StringRef Directory, std::string &ErrorMessage) {
115     llvm::SmallString<1024> JSONDatabasePath(Directory);
116     llvm::sys::path::append(JSONDatabasePath, "compile_commands.json");
117     llvm::OwningPtr<CompilationDatabase> Database(
118         JSONCompilationDatabase::loadFromFile(JSONDatabasePath, ErrorMessage));
119     if (!Database)
120       return NULL;
121     return Database.take();
122   }
123 };
124 
125 // Register the JSONCompilationDatabasePlugin with the
126 // CompilationDatabasePluginRegistry using this statically initialized variable.
127 static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin>
128 X("json-compilation-database", "Reads JSON formatted compilation databases");
129 
130 // This anchor is used to force the linker to link in the generated object file
131 // and thus register the JSONCompilationDatabasePlugin.
132 volatile int JSONAnchorSource = 0;
133 
134 JSONCompilationDatabase *
135 JSONCompilationDatabase::loadFromFile(StringRef FilePath,
136                                       std::string &ErrorMessage) {
137   llvm::OwningPtr<llvm::MemoryBuffer> DatabaseBuffer;
138   llvm::error_code Result =
139     llvm::MemoryBuffer::getFile(FilePath, DatabaseBuffer);
140   if (Result != 0) {
141     ErrorMessage = "Error while opening JSON database: " + Result.message();
142     return NULL;
143   }
144   llvm::OwningPtr<JSONCompilationDatabase> Database(
145     new JSONCompilationDatabase(DatabaseBuffer.take()));
146   if (!Database->parse(ErrorMessage))
147     return NULL;
148   return Database.take();
149 }
150 
151 JSONCompilationDatabase *
152 JSONCompilationDatabase::loadFromBuffer(StringRef DatabaseString,
153                                         std::string &ErrorMessage) {
154   llvm::OwningPtr<llvm::MemoryBuffer> DatabaseBuffer(
155       llvm::MemoryBuffer::getMemBuffer(DatabaseString));
156   llvm::OwningPtr<JSONCompilationDatabase> Database(
157     new JSONCompilationDatabase(DatabaseBuffer.take()));
158   if (!Database->parse(ErrorMessage))
159     return NULL;
160   return Database.take();
161 }
162 
163 std::vector<CompileCommand>
164 JSONCompilationDatabase::getCompileCommands(StringRef FilePath) const {
165   llvm::SmallString<128> NativeFilePath;
166   llvm::sys::path::native(FilePath, NativeFilePath);
167   std::vector<StringRef> PossibleMatches;
168   std::string Error;
169   llvm::raw_string_ostream ES(Error);
170   StringRef Match = MatchTrie.findEquivalent(NativeFilePath.str(), ES);
171   if (Match.empty()) {
172     if (Error.empty())
173       Error = "No match found.";
174     llvm::outs() << Error << "\n";
175     return std::vector<CompileCommand>();
176   }
177   llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
178     CommandsRefI = IndexByFile.find(Match);
179   if (CommandsRefI == IndexByFile.end())
180     return std::vector<CompileCommand>();
181   std::vector<CompileCommand> Commands;
182   getCommands(CommandsRefI->getValue(), Commands);
183   return Commands;
184 }
185 
186 std::vector<std::string>
187 JSONCompilationDatabase::getAllFiles() const {
188   std::vector<std::string> Result;
189 
190   llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
191     CommandsRefI = IndexByFile.begin();
192   const llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
193     CommandsRefEnd = IndexByFile.end();
194   for (; CommandsRefI != CommandsRefEnd; ++CommandsRefI) {
195     Result.push_back(CommandsRefI->first().str());
196   }
197 
198   return Result;
199 }
200 
201 std::vector<CompileCommand>
202 JSONCompilationDatabase::getAllCompileCommands() const {
203   std::vector<CompileCommand> Commands;
204   for (llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
205         CommandsRefI = IndexByFile.begin(), CommandsRefEnd = IndexByFile.end();
206       CommandsRefI != CommandsRefEnd; ++CommandsRefI) {
207     getCommands(CommandsRefI->getValue(), Commands);
208   }
209   return Commands;
210 }
211 
212 void JSONCompilationDatabase::getCommands(
213                                   ArrayRef<CompileCommandRef> CommandsRef,
214                                   std::vector<CompileCommand> &Commands) const {
215   for (int I = 0, E = CommandsRef.size(); I != E; ++I) {
216     llvm::SmallString<8> DirectoryStorage;
217     llvm::SmallString<1024> CommandStorage;
218     Commands.push_back(CompileCommand(
219       // FIXME: Escape correctly:
220       CommandsRef[I].first->getValue(DirectoryStorage),
221       unescapeCommandLine(CommandsRef[I].second->getValue(CommandStorage))));
222   }
223 }
224 
225 bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
226   llvm::yaml::document_iterator I = YAMLStream.begin();
227   if (I == YAMLStream.end()) {
228     ErrorMessage = "Error while parsing YAML.";
229     return false;
230   }
231   llvm::yaml::Node *Root = I->getRoot();
232   if (Root == NULL) {
233     ErrorMessage = "Error while parsing YAML.";
234     return false;
235   }
236   llvm::yaml::SequenceNode *Array =
237     llvm::dyn_cast<llvm::yaml::SequenceNode>(Root);
238   if (Array == NULL) {
239     ErrorMessage = "Expected array.";
240     return false;
241   }
242   for (llvm::yaml::SequenceNode::iterator AI = Array->begin(),
243                                           AE = Array->end();
244        AI != AE; ++AI) {
245     llvm::yaml::MappingNode *Object =
246       llvm::dyn_cast<llvm::yaml::MappingNode>(&*AI);
247     if (Object == NULL) {
248       ErrorMessage = "Expected object.";
249       return false;
250     }
251     llvm::yaml::ScalarNode *Directory = NULL;
252     llvm::yaml::ScalarNode *Command = NULL;
253     llvm::yaml::ScalarNode *File = NULL;
254     for (llvm::yaml::MappingNode::iterator KVI = Object->begin(),
255                                            KVE = Object->end();
256          KVI != KVE; ++KVI) {
257       llvm::yaml::Node *Value = (*KVI).getValue();
258       if (Value == NULL) {
259         ErrorMessage = "Expected value.";
260         return false;
261       }
262       llvm::yaml::ScalarNode *ValueString =
263         llvm::dyn_cast<llvm::yaml::ScalarNode>(Value);
264       if (ValueString == NULL) {
265         ErrorMessage = "Expected string as value.";
266         return false;
267       }
268       llvm::yaml::ScalarNode *KeyString =
269         llvm::dyn_cast<llvm::yaml::ScalarNode>((*KVI).getKey());
270       if (KeyString == NULL) {
271         ErrorMessage = "Expected strings as key.";
272         return false;
273       }
274       llvm::SmallString<8> KeyStorage;
275       if (KeyString->getValue(KeyStorage) == "directory") {
276         Directory = ValueString;
277       } else if (KeyString->getValue(KeyStorage) == "command") {
278         Command = ValueString;
279       } else if (KeyString->getValue(KeyStorage) == "file") {
280         File = ValueString;
281       } else {
282         ErrorMessage = ("Unknown key: \"" +
283                         KeyString->getRawValue() + "\"").str();
284         return false;
285       }
286     }
287     if (!File) {
288       ErrorMessage = "Missing key: \"file\".";
289       return false;
290     }
291     if (!Command) {
292       ErrorMessage = "Missing key: \"command\".";
293       return false;
294     }
295     if (!Directory) {
296       ErrorMessage = "Missing key: \"directory\".";
297       return false;
298     }
299     llvm::SmallString<8> FileStorage;
300     StringRef FileName = File->getValue(FileStorage);
301     llvm::SmallString<128> NativeFilePath;
302     if (llvm::sys::path::is_relative(FileName)) {
303       llvm::SmallString<8> DirectoryStorage;
304       llvm::SmallString<128> AbsolutePath(
305           Directory->getValue(DirectoryStorage));
306       llvm::sys::path::append(AbsolutePath, FileName);
307       llvm::sys::path::native(AbsolutePath.str(), NativeFilePath);
308     } else {
309       llvm::sys::path::native(FileName, NativeFilePath);
310     }
311     IndexByFile[NativeFilePath].push_back(
312         CompileCommandRef(Directory, Command));
313     MatchTrie.insert(NativeFilePath.str());
314   }
315   return true;
316 }
317 
318 } // end namespace tooling
319 } // end namespace clang
320