1 | //===- JSONCompilationDatabase.cpp ----------------------------------------===// |
---|---|
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 contains the implementation of the JSONCompilationDatabase. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "clang/Tooling/JSONCompilationDatabase.h" |
14 | #include "clang/Basic/LLVM.h" |
15 | #include "clang/Tooling/CompilationDatabase.h" |
16 | #include "clang/Tooling/CompilationDatabasePluginRegistry.h" |
17 | #include "clang/Tooling/Tooling.h" |
18 | #include "llvm/ADT/SmallVector.h" |
19 | #include "llvm/ADT/StringRef.h" |
20 | #include "llvm/Support/Allocator.h" |
21 | #include "llvm/Support/CommandLine.h" |
22 | #include "llvm/Support/ErrorOr.h" |
23 | #include "llvm/Support/MemoryBuffer.h" |
24 | #include "llvm/Support/Path.h" |
25 | #include "llvm/Support/StringSaver.h" |
26 | #include "llvm/Support/VirtualFileSystem.h" |
27 | #include "llvm/Support/YAMLParser.h" |
28 | #include "llvm/Support/raw_ostream.h" |
29 | #include "llvm/TargetParser/Host.h" |
30 | #include <cassert> |
31 | #include <memory> |
32 | #include <optional> |
33 | #include <string> |
34 | #include <system_error> |
35 | #include <utility> |
36 | #include <vector> |
37 | |
38 | using namespace clang; |
39 | using namespace tooling; |
40 | |
41 | namespace { |
42 | |
43 | /// A parser for escaped strings of command line arguments. |
44 | /// |
45 | /// Assumes \-escaping for quoted arguments (see the documentation of |
46 | /// unescapeCommandLine(...)). |
47 | class CommandLineArgumentParser { |
48 | public: |
49 | CommandLineArgumentParser(StringRef CommandLine) |
50 | : Input(CommandLine), Position(Input.begin()-1) {} |
51 | |
52 | std::vector<std::string> parse() { |
53 | bool HasMoreInput = true; |
54 | while (HasMoreInput && nextNonWhitespace()) { |
55 | std::string Argument; |
56 | HasMoreInput = parseStringInto(String&: Argument); |
57 | CommandLine.push_back(x: Argument); |
58 | } |
59 | return CommandLine; |
60 | } |
61 | |
62 | private: |
63 | // All private methods return true if there is more input available. |
64 | |
65 | bool parseStringInto(std::string &String) { |
66 | do { |
67 | if (*Position == '"') { |
68 | if (!parseDoubleQuotedStringInto(String)) return false; |
69 | } else if (*Position == '\'') { |
70 | if (!parseSingleQuotedStringInto(String)) return false; |
71 | } else { |
72 | if (!parseFreeStringInto(String)) return false; |
73 | } |
74 | } while (*Position != ' '); |
75 | return true; |
76 | } |
77 | |
78 | bool parseDoubleQuotedStringInto(std::string &String) { |
79 | if (!next()) return false; |
80 | while (*Position != '"') { |
81 | if (!skipEscapeCharacter()) return false; |
82 | String.push_back(c: *Position); |
83 | if (!next()) return false; |
84 | } |
85 | return next(); |
86 | } |
87 | |
88 | bool parseSingleQuotedStringInto(std::string &String) { |
89 | if (!next()) return false; |
90 | while (*Position != '\'') { |
91 | String.push_back(c: *Position); |
92 | if (!next()) return false; |
93 | } |
94 | return next(); |
95 | } |
96 | |
97 | bool parseFreeStringInto(std::string &String) { |
98 | do { |
99 | if (!skipEscapeCharacter()) return false; |
100 | String.push_back(c: *Position); |
101 | if (!next()) return false; |
102 | } while (*Position != ' ' && *Position != '"' && *Position != '\''); |
103 | return true; |
104 | } |
105 | |
106 | bool skipEscapeCharacter() { |
107 | if (*Position == '\\') { |
108 | return next(); |
109 | } |
110 | return true; |
111 | } |
112 | |
113 | bool nextNonWhitespace() { |
114 | do { |
115 | if (!next()) return false; |
116 | } while (*Position == ' '); |
117 | return true; |
118 | } |
119 | |
120 | bool next() { |
121 | ++Position; |
122 | return Position != Input.end(); |
123 | } |
124 | |
125 | const StringRef Input; |
126 | StringRef::iterator Position; |
127 | std::vector<std::string> CommandLine; |
128 | }; |
129 | |
130 | std::vector<std::string> unescapeCommandLine(JSONCommandLineSyntax Syntax, |
131 | StringRef EscapedCommandLine) { |
132 | if (Syntax == JSONCommandLineSyntax::AutoDetect) { |
133 | #ifdef _WIN32 |
134 | // Assume Windows command line parsing on Win32 |
135 | Syntax = JSONCommandLineSyntax::Windows; |
136 | #else |
137 | Syntax = JSONCommandLineSyntax::Gnu; |
138 | #endif |
139 | } |
140 | |
141 | if (Syntax == JSONCommandLineSyntax::Windows) { |
142 | llvm::BumpPtrAllocator Alloc; |
143 | llvm::StringSaver Saver(Alloc); |
144 | llvm::SmallVector<const char *, 64> T; |
145 | llvm::cl::TokenizeWindowsCommandLine(Source: EscapedCommandLine, Saver, NewArgv&: T); |
146 | std::vector<std::string> Result(T.begin(), T.end()); |
147 | return Result; |
148 | } |
149 | assert(Syntax == JSONCommandLineSyntax::Gnu); |
150 | CommandLineArgumentParser parser(EscapedCommandLine); |
151 | return parser.parse(); |
152 | } |
153 | |
154 | // This plugin locates a nearby compile_command.json file, and also infers |
155 | // compile commands for files not present in the database. |
156 | class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin { |
157 | std::unique_ptr<CompilationDatabase> |
158 | loadFromDirectory(StringRef Directory, std::string &ErrorMessage) override { |
159 | SmallString<1024> JSONDatabasePath(Directory); |
160 | llvm::sys::path::append(path&: JSONDatabasePath, a: "compile_commands.json"); |
161 | auto Base = JSONCompilationDatabase::loadFromFile( |
162 | FilePath: JSONDatabasePath, ErrorMessage, Syntax: JSONCommandLineSyntax::AutoDetect); |
163 | return Base ? inferTargetAndDriverMode( |
164 | Base: inferMissingCompileCommands(expandResponseFiles( |
165 | Base: std::move(Base), FS: llvm::vfs::getRealFileSystem()))) |
166 | : nullptr; |
167 | } |
168 | }; |
169 | |
170 | } // namespace |
171 | |
172 | // Register the JSONCompilationDatabasePlugin with the |
173 | // CompilationDatabasePluginRegistry using this statically initialized variable. |
174 | static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin> |
175 | X("json-compilation-database", "Reads JSON formatted compilation databases"); |
176 | |
177 | namespace clang { |
178 | namespace tooling { |
179 | |
180 | // This anchor is used to force the linker to link in the generated object file |
181 | // and thus register the JSONCompilationDatabasePlugin. |
182 | volatile int JSONAnchorSource = 0; |
183 | |
184 | } // namespace tooling |
185 | } // namespace clang |
186 | |
187 | std::unique_ptr<JSONCompilationDatabase> |
188 | JSONCompilationDatabase::loadFromFile(StringRef FilePath, |
189 | std::string &ErrorMessage, |
190 | JSONCommandLineSyntax Syntax) { |
191 | // Don't mmap: if we're a long-lived process, the build system may overwrite. |
192 | llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> DatabaseBuffer = |
193 | llvm::MemoryBuffer::getFile(Filename: FilePath, /*IsText=*/false, |
194 | /*RequiresNullTerminator=*/true, |
195 | /*IsVolatile=*/true); |
196 | if (std::error_code Result = DatabaseBuffer.getError()) { |
197 | ErrorMessage = "Error while opening JSON database: "+ Result.message(); |
198 | return nullptr; |
199 | } |
200 | std::unique_ptr<JSONCompilationDatabase> Database( |
201 | new JSONCompilationDatabase(std::move(*DatabaseBuffer), Syntax)); |
202 | if (!Database->parse(ErrorMessage)) |
203 | return nullptr; |
204 | return Database; |
205 | } |
206 | |
207 | std::unique_ptr<JSONCompilationDatabase> |
208 | JSONCompilationDatabase::loadFromBuffer(StringRef DatabaseString, |
209 | std::string &ErrorMessage, |
210 | JSONCommandLineSyntax Syntax) { |
211 | std::unique_ptr<llvm::MemoryBuffer> DatabaseBuffer( |
212 | llvm::MemoryBuffer::getMemBufferCopy(InputData: DatabaseString)); |
213 | std::unique_ptr<JSONCompilationDatabase> Database( |
214 | new JSONCompilationDatabase(std::move(DatabaseBuffer), Syntax)); |
215 | if (!Database->parse(ErrorMessage)) |
216 | return nullptr; |
217 | return Database; |
218 | } |
219 | |
220 | std::vector<CompileCommand> |
221 | JSONCompilationDatabase::getCompileCommands(StringRef FilePath) const { |
222 | SmallString<128> NativeFilePath; |
223 | llvm::sys::path::native(path: FilePath, result&: NativeFilePath); |
224 | |
225 | std::string Error; |
226 | llvm::raw_string_ostream ES(Error); |
227 | StringRef Match = MatchTrie.findEquivalent(FileName: NativeFilePath, Error&: ES); |
228 | if (Match.empty()) |
229 | return {}; |
230 | const auto CommandsRefI = IndexByFile.find(Key: Match); |
231 | if (CommandsRefI == IndexByFile.end()) |
232 | return {}; |
233 | std::vector<CompileCommand> Commands; |
234 | getCommands(CommandsRef: CommandsRefI->getValue(), Commands); |
235 | return Commands; |
236 | } |
237 | |
238 | std::vector<std::string> |
239 | JSONCompilationDatabase::getAllFiles() const { |
240 | std::vector<std::string> Result; |
241 | for (const auto &CommandRef : IndexByFile) |
242 | Result.push_back(x: CommandRef.first().str()); |
243 | return Result; |
244 | } |
245 | |
246 | std::vector<CompileCommand> |
247 | JSONCompilationDatabase::getAllCompileCommands() const { |
248 | std::vector<CompileCommand> Commands; |
249 | getCommands(CommandsRef: AllCommands, Commands); |
250 | return Commands; |
251 | } |
252 | |
253 | static llvm::StringRef stripExecutableExtension(llvm::StringRef Name) { |
254 | Name.consume_back(Suffix: ".exe"); |
255 | return Name; |
256 | } |
257 | |
258 | // There are compiler-wrappers (ccache, distcc) that take the "real" |
259 | // compiler as an argument, e.g. distcc gcc -O3 foo.c. |
260 | // These end up in compile_commands.json when people set CC="distcc gcc". |
261 | // Clang's driver doesn't understand this, so we need to unwrap. |
262 | static bool unwrapCommand(std::vector<std::string> &Args) { |
263 | if (Args.size() < 2) |
264 | return false; |
265 | StringRef Wrapper = |
266 | stripExecutableExtension(Name: llvm::sys::path::filename(path: Args.front())); |
267 | if (Wrapper == "distcc"|| Wrapper == "ccache"|| Wrapper == "sccache") { |
268 | // Most of these wrappers support being invoked 3 ways: |
269 | // `distcc g++ file.c` This is the mode we're trying to match. |
270 | // We need to drop `distcc`. |
271 | // `distcc file.c` This acts like compiler is cc or similar. |
272 | // Clang's driver can handle this, no change needed. |
273 | // `g++ file.c` g++ is a symlink to distcc. |
274 | // We don't even notice this case, and all is well. |
275 | // |
276 | // We need to distinguish between the first and second case. |
277 | // The wrappers themselves don't take flags, so Args[1] is a compiler flag, |
278 | // an input file, or a compiler. Inputs have extensions, compilers don't. |
279 | bool HasCompiler = |
280 | (Args[1][0] != '-') && |
281 | !llvm::sys::path::has_extension(path: stripExecutableExtension(Name: Args[1])); |
282 | if (HasCompiler) { |
283 | Args.erase(position: Args.begin()); |
284 | return true; |
285 | } |
286 | // If !HasCompiler, wrappers act like GCC. Fine: so do we. |
287 | } |
288 | return false; |
289 | } |
290 | |
291 | static std::vector<std::string> |
292 | nodeToCommandLine(JSONCommandLineSyntax Syntax, |
293 | const std::vector<llvm::yaml::ScalarNode *> &Nodes) { |
294 | SmallString<1024> Storage; |
295 | std::vector<std::string> Arguments; |
296 | if (Nodes.size() == 1) |
297 | Arguments = unescapeCommandLine(Syntax, EscapedCommandLine: Nodes[0]->getValue(Storage)); |
298 | else |
299 | for (const auto *Node : Nodes) |
300 | Arguments.push_back(x: std::string(Node->getValue(Storage))); |
301 | // There may be multiple wrappers: using distcc and ccache together is common. |
302 | while (unwrapCommand(Args&: Arguments)) |
303 | ; |
304 | return Arguments; |
305 | } |
306 | |
307 | void JSONCompilationDatabase::getCommands( |
308 | ArrayRef<CompileCommandRef> CommandsRef, |
309 | std::vector<CompileCommand> &Commands) const { |
310 | for (const auto &CommandRef : CommandsRef) { |
311 | SmallString<8> DirectoryStorage; |
312 | SmallString<32> FilenameStorage; |
313 | SmallString<32> OutputStorage; |
314 | auto Output = std::get<3>(t: CommandRef); |
315 | Commands.emplace_back( |
316 | args: std::get<0>(t: CommandRef)->getValue(Storage&: DirectoryStorage), |
317 | args: std::get<1>(t: CommandRef)->getValue(Storage&: FilenameStorage), |
318 | args: nodeToCommandLine(Syntax, Nodes: std::get<2>(t: CommandRef)), |
319 | args: Output ? Output->getValue(Storage&: OutputStorage) : ""); |
320 | } |
321 | } |
322 | |
323 | bool JSONCompilationDatabase::parse(std::string &ErrorMessage) { |
324 | llvm::yaml::document_iterator I = YAMLStream.begin(); |
325 | if (I == YAMLStream.end()) { |
326 | ErrorMessage = "Error while parsing YAML."; |
327 | return false; |
328 | } |
329 | llvm::yaml::Node *Root = I->getRoot(); |
330 | if (!Root) { |
331 | ErrorMessage = "Error while parsing YAML."; |
332 | return false; |
333 | } |
334 | auto *Array = dyn_cast<llvm::yaml::SequenceNode>(Val: Root); |
335 | if (!Array) { |
336 | ErrorMessage = "Expected array."; |
337 | return false; |
338 | } |
339 | for (auto &NextObject : *Array) { |
340 | auto *Object = dyn_cast<llvm::yaml::MappingNode>(Val: &NextObject); |
341 | if (!Object) { |
342 | ErrorMessage = "Expected object."; |
343 | return false; |
344 | } |
345 | llvm::yaml::ScalarNode *Directory = nullptr; |
346 | std::optional<std::vector<llvm::yaml::ScalarNode *>> Command; |
347 | llvm::yaml::ScalarNode *File = nullptr; |
348 | llvm::yaml::ScalarNode *Output = nullptr; |
349 | for (auto& NextKeyValue : *Object) { |
350 | auto *KeyString = dyn_cast<llvm::yaml::ScalarNode>(Val: NextKeyValue.getKey()); |
351 | if (!KeyString) { |
352 | ErrorMessage = "Expected strings as key."; |
353 | return false; |
354 | } |
355 | SmallString<10> KeyStorage; |
356 | StringRef KeyValue = KeyString->getValue(Storage&: KeyStorage); |
357 | llvm::yaml::Node *Value = NextKeyValue.getValue(); |
358 | if (!Value) { |
359 | ErrorMessage = "Expected value."; |
360 | return false; |
361 | } |
362 | auto *ValueString = dyn_cast<llvm::yaml::ScalarNode>(Val: Value); |
363 | auto *SequenceString = dyn_cast<llvm::yaml::SequenceNode>(Val: Value); |
364 | if (KeyValue == "arguments") { |
365 | if (!SequenceString) { |
366 | ErrorMessage = "Expected sequence as value."; |
367 | return false; |
368 | } |
369 | Command = std::vector<llvm::yaml::ScalarNode *>(); |
370 | for (auto &Argument : *SequenceString) { |
371 | auto *Scalar = dyn_cast<llvm::yaml::ScalarNode>(Val: &Argument); |
372 | if (!Scalar) { |
373 | ErrorMessage = "Only strings are allowed in 'arguments'."; |
374 | return false; |
375 | } |
376 | Command->push_back(x: Scalar); |
377 | } |
378 | } else { |
379 | if (!ValueString) { |
380 | ErrorMessage = "Expected string as value."; |
381 | return false; |
382 | } |
383 | if (KeyValue == "directory") { |
384 | Directory = ValueString; |
385 | } else if (KeyValue == "command") { |
386 | if (!Command) |
387 | Command = std::vector<llvm::yaml::ScalarNode *>(1, ValueString); |
388 | } else if (KeyValue == "file") { |
389 | File = ValueString; |
390 | } else if (KeyValue == "output") { |
391 | Output = ValueString; |
392 | } else { |
393 | ErrorMessage = |
394 | ("Unknown key: \""+ KeyString->getRawValue() + "\"").str(); |
395 | return false; |
396 | } |
397 | } |
398 | } |
399 | if (!File) { |
400 | ErrorMessage = "Missing key: \"file\"."; |
401 | return false; |
402 | } |
403 | if (!Command) { |
404 | ErrorMessage = "Missing key: \"command\" or \"arguments\"."; |
405 | return false; |
406 | } |
407 | if (!Directory) { |
408 | ErrorMessage = "Missing key: \"directory\"."; |
409 | return false; |
410 | } |
411 | SmallString<8> FileStorage; |
412 | StringRef FileName = File->getValue(Storage&: FileStorage); |
413 | SmallString<128> NativeFilePath; |
414 | if (llvm::sys::path::is_relative(path: FileName)) { |
415 | SmallString<8> DirectoryStorage; |
416 | SmallString<128> AbsolutePath(Directory->getValue(Storage&: DirectoryStorage)); |
417 | llvm::sys::path::append(path&: AbsolutePath, a: FileName); |
418 | llvm::sys::path::native(path: AbsolutePath, result&: NativeFilePath); |
419 | } else { |
420 | llvm::sys::path::native(path: FileName, result&: NativeFilePath); |
421 | } |
422 | llvm::sys::path::remove_dots(path&: NativeFilePath, /*remove_dot_dot=*/true); |
423 | auto Cmd = CompileCommandRef(Directory, File, *Command, Output); |
424 | IndexByFile[NativeFilePath].push_back(x: Cmd); |
425 | AllCommands.push_back(x: Cmd); |
426 | MatchTrie.insert(NewPath: NativeFilePath); |
427 | } |
428 | return true; |
429 | } |
430 |
Definitions
- CommandLineArgumentParser
- CommandLineArgumentParser
- parse
- parseStringInto
- parseDoubleQuotedStringInto
- parseSingleQuotedStringInto
- parseFreeStringInto
- skipEscapeCharacter
- nextNonWhitespace
- next
- unescapeCommandLine
- JSONCompilationDatabasePlugin
- loadFromDirectory
- X
- JSONAnchorSource
- loadFromFile
- loadFromBuffer
- getCompileCommands
- getAllFiles
- getAllCompileCommands
- stripExecutableExtension
- unwrapCommand
- nodeToCommandLine
- getCommands
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