clang  14.0.0git
JSONCompilationDatabase.cpp
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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 
14 #include "clang/Basic/LLVM.h"
17 #include "clang/Tooling/Tooling.h"
18 #include "llvm/ADT/Optional.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/SmallString.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/StringRef.h"
23 #include "llvm/ADT/Triple.h"
24 #include "llvm/Support/Allocator.h"
25 #include "llvm/Support/Casting.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Support/ErrorOr.h"
28 #include "llvm/Support/Host.h"
29 #include "llvm/Support/MemoryBuffer.h"
30 #include "llvm/Support/Path.h"
31 #include "llvm/Support/StringSaver.h"
32 #include "llvm/Support/VirtualFileSystem.h"
33 #include "llvm/Support/YAMLParser.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include <cassert>
36 #include <memory>
37 #include <string>
38 #include <system_error>
39 #include <tuple>
40 #include <utility>
41 #include <vector>
42 
43 using namespace clang;
44 using namespace tooling;
45 
46 namespace {
47 
48 /// A parser for escaped strings of command line arguments.
49 ///
50 /// Assumes \-escaping for quoted arguments (see the documentation of
51 /// unescapeCommandLine(...)).
52 class CommandLineArgumentParser {
53  public:
54  CommandLineArgumentParser(StringRef CommandLine)
55  : Input(CommandLine), Position(Input.begin()-1) {}
56 
57  std::vector<std::string> parse() {
58  bool HasMoreInput = true;
59  while (HasMoreInput && nextNonWhitespace()) {
60  std::string Argument;
61  HasMoreInput = parseStringInto(Argument);
62  CommandLine.push_back(Argument);
63  }
64  return CommandLine;
65  }
66 
67  private:
68  // All private methods return true if there is more input available.
69 
70  bool parseStringInto(std::string &String) {
71  do {
72  if (*Position == '"') {
73  if (!parseDoubleQuotedStringInto(String)) return false;
74  } else if (*Position == '\'') {
75  if (!parseSingleQuotedStringInto(String)) return false;
76  } else {
77  if (!parseFreeStringInto(String)) return false;
78  }
79  } while (*Position != ' ');
80  return true;
81  }
82 
83  bool parseDoubleQuotedStringInto(std::string &String) {
84  if (!next()) return false;
85  while (*Position != '"') {
86  if (!skipEscapeCharacter()) return false;
87  String.push_back(*Position);
88  if (!next()) return false;
89  }
90  return next();
91  }
92 
93  bool parseSingleQuotedStringInto(std::string &String) {
94  if (!next()) return false;
95  while (*Position != '\'') {
96  String.push_back(*Position);
97  if (!next()) return false;
98  }
99  return next();
100  }
101 
102  bool parseFreeStringInto(std::string &String) {
103  do {
104  if (!skipEscapeCharacter()) return false;
105  String.push_back(*Position);
106  if (!next()) return false;
107  } while (*Position != ' ' && *Position != '"' && *Position != '\'');
108  return true;
109  }
110 
111  bool skipEscapeCharacter() {
112  if (*Position == '\\') {
113  return next();
114  }
115  return true;
116  }
117 
118  bool nextNonWhitespace() {
119  do {
120  if (!next()) return false;
121  } while (*Position == ' ');
122  return true;
123  }
124 
125  bool next() {
126  ++Position;
127  return Position != Input.end();
128  }
129 
130  const StringRef Input;
131  StringRef::iterator Position;
132  std::vector<std::string> CommandLine;
133 };
134 
135 std::vector<std::string> unescapeCommandLine(JSONCommandLineSyntax Syntax,
136  StringRef EscapedCommandLine) {
137  if (Syntax == JSONCommandLineSyntax::AutoDetect) {
138 #ifdef _WIN32
139  // Assume Windows command line parsing on Win32
141 #else
143 #endif
144  }
145 
146  if (Syntax == JSONCommandLineSyntax::Windows) {
147  llvm::BumpPtrAllocator Alloc;
148  llvm::StringSaver Saver(Alloc);
150  llvm::cl::TokenizeWindowsCommandLine(EscapedCommandLine, Saver, T);
151  std::vector<std::string> Result(T.begin(), T.end());
152  return Result;
153  }
154  assert(Syntax == JSONCommandLineSyntax::Gnu);
155  CommandLineArgumentParser parser(EscapedCommandLine);
156  return parser.parse();
157 }
158 
159 // This plugin locates a nearby compile_command.json file, and also infers
160 // compile commands for files not present in the database.
161 class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {
162  std::unique_ptr<CompilationDatabase>
163  loadFromDirectory(StringRef Directory, std::string &ErrorMessage) override {
164  SmallString<1024> JSONDatabasePath(Directory);
165  llvm::sys::path::append(JSONDatabasePath, "compile_commands.json");
167  JSONDatabasePath, ErrorMessage, JSONCommandLineSyntax::AutoDetect);
170  std::move(Base), llvm::vfs::getRealFileSystem())))
171  : nullptr;
172  }
173 };
174 
175 } // namespace
176 
177 // Register the JSONCompilationDatabasePlugin with the
178 // CompilationDatabasePluginRegistry using this statically initialized variable.
179 static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin>
180 X("json-compilation-database", "Reads JSON formatted compilation databases");
181 
182 namespace clang {
183 namespace tooling {
184 
185 // This anchor is used to force the linker to link in the generated object file
186 // and thus register the JSONCompilationDatabasePlugin.
187 volatile int JSONAnchorSource = 0;
188 
189 } // namespace tooling
190 } // namespace clang
191 
192 std::unique_ptr<JSONCompilationDatabase>
194  std::string &ErrorMessage,
195  JSONCommandLineSyntax Syntax) {
196  // Don't mmap: if we're a long-lived process, the build system may overwrite.
197  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> DatabaseBuffer =
198  llvm::MemoryBuffer::getFile(FilePath, /*IsText=*/false,
199  /*RequiresNullTerminator=*/true,
200  /*IsVolatile=*/true);
201  if (std::error_code Result = DatabaseBuffer.getError()) {
202  ErrorMessage = "Error while opening JSON database: " + Result.message();
203  return nullptr;
204  }
205  std::unique_ptr<JSONCompilationDatabase> Database(
206  new JSONCompilationDatabase(std::move(*DatabaseBuffer), Syntax));
207  if (!Database->parse(ErrorMessage))
208  return nullptr;
209  return Database;
210 }
211 
212 std::unique_ptr<JSONCompilationDatabase>
214  std::string &ErrorMessage,
215  JSONCommandLineSyntax Syntax) {
216  std::unique_ptr<llvm::MemoryBuffer> DatabaseBuffer(
217  llvm::MemoryBuffer::getMemBufferCopy(DatabaseString));
218  std::unique_ptr<JSONCompilationDatabase> Database(
219  new JSONCompilationDatabase(std::move(DatabaseBuffer), Syntax));
220  if (!Database->parse(ErrorMessage))
221  return nullptr;
222  return Database;
223 }
224 
225 std::vector<CompileCommand>
227  SmallString<128> NativeFilePath;
228  llvm::sys::path::native(FilePath, NativeFilePath);
229 
231  llvm::raw_string_ostream ES(Error);
232  StringRef Match = MatchTrie.findEquivalent(NativeFilePath, ES);
233  if (Match.empty())
234  return {};
235  const auto CommandsRefI = IndexByFile.find(Match);
236  if (CommandsRefI == IndexByFile.end())
237  return {};
238  std::vector<CompileCommand> Commands;
239  getCommands(CommandsRefI->getValue(), Commands);
240  return Commands;
241 }
242 
243 std::vector<std::string>
245  std::vector<std::string> Result;
246  for (const auto &CommandRef : IndexByFile)
247  Result.push_back(CommandRef.first().str());
248  return Result;
249 }
250 
251 std::vector<CompileCommand>
253  std::vector<CompileCommand> Commands;
254  getCommands(AllCommands, Commands);
255  return Commands;
256 }
257 
258 static llvm::StringRef stripExecutableExtension(llvm::StringRef Name) {
259  Name.consume_back(".exe");
260  return Name;
261 }
262 
263 // There are compiler-wrappers (ccache, distcc, gomacc) that take the "real"
264 // compiler as an argument, e.g. distcc gcc -O3 foo.c.
265 // These end up in compile_commands.json when people set CC="distcc gcc".
266 // Clang's driver doesn't understand this, so we need to unwrap.
267 static bool unwrapCommand(std::vector<std::string> &Args) {
268  if (Args.size() < 2)
269  return false;
270  StringRef Wrapper =
271  stripExecutableExtension(llvm::sys::path::filename(Args.front()));
272  if (Wrapper == "distcc" || Wrapper == "gomacc" || Wrapper == "ccache" ||
273  Wrapper == "sccache") {
274  // Most of these wrappers support being invoked 3 ways:
275  // `distcc g++ file.c` This is the mode we're trying to match.
276  // We need to drop `distcc`.
277  // `distcc file.c` This acts like compiler is cc or similar.
278  // Clang's driver can handle this, no change needed.
279  // `g++ file.c` g++ is a symlink to distcc.
280  // We don't even notice this case, and all is well.
281  //
282  // We need to distinguish between the first and second case.
283  // The wrappers themselves don't take flags, so Args[1] is a compiler flag,
284  // an input file, or a compiler. Inputs have extensions, compilers don't.
285  bool HasCompiler =
286  (Args[1][0] != '-') &&
287  !llvm::sys::path::has_extension(stripExecutableExtension(Args[1]));
288  if (HasCompiler) {
289  Args.erase(Args.begin());
290  return true;
291  }
292  // If !HasCompiler, wrappers act like GCC. Fine: so do we.
293  }
294  return false;
295 }
296 
297 static std::vector<std::string>
299  const std::vector<llvm::yaml::ScalarNode *> &Nodes) {
300  SmallString<1024> Storage;
301  std::vector<std::string> Arguments;
302  if (Nodes.size() == 1)
303  Arguments = unescapeCommandLine(Syntax, Nodes[0]->getValue(Storage));
304  else
305  for (const auto *Node : Nodes)
306  Arguments.push_back(std::string(Node->getValue(Storage)));
307  // There may be multiple wrappers: using distcc and ccache together is common.
308  while (unwrapCommand(Arguments))
309  ;
310  return Arguments;
311 }
312 
313 void JSONCompilationDatabase::getCommands(
314  ArrayRef<CompileCommandRef> CommandsRef,
315  std::vector<CompileCommand> &Commands) const {
316  for (const auto &CommandRef : CommandsRef) {
317  SmallString<8> DirectoryStorage;
318  SmallString<32> FilenameStorage;
319  SmallString<32> OutputStorage;
320  auto Output = std::get<3>(CommandRef);
321  Commands.emplace_back(
322  std::get<0>(CommandRef)->getValue(DirectoryStorage),
323  std::get<1>(CommandRef)->getValue(FilenameStorage),
324  nodeToCommandLine(Syntax, std::get<2>(CommandRef)),
325  Output ? Output->getValue(OutputStorage) : "");
326  }
327 }
328 
329 bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
330  llvm::yaml::document_iterator I = YAMLStream.begin();
331  if (I == YAMLStream.end()) {
332  ErrorMessage = "Error while parsing YAML.";
333  return false;
334  }
335  llvm::yaml::Node *Root = I->getRoot();
336  if (!Root) {
337  ErrorMessage = "Error while parsing YAML.";
338  return false;
339  }
340  auto *Array = dyn_cast<llvm::yaml::SequenceNode>(Root);
341  if (!Array) {
342  ErrorMessage = "Expected array.";
343  return false;
344  }
345  for (auto &NextObject : *Array) {
346  auto *Object = dyn_cast<llvm::yaml::MappingNode>(&NextObject);
347  if (!Object) {
348  ErrorMessage = "Expected object.";
349  return false;
350  }
351  llvm::yaml::ScalarNode *Directory = nullptr;
353  llvm::yaml::ScalarNode *File = nullptr;
354  llvm::yaml::ScalarNode *Output = nullptr;
355  for (auto& NextKeyValue : *Object) {
356  auto *KeyString = dyn_cast<llvm::yaml::ScalarNode>(NextKeyValue.getKey());
357  if (!KeyString) {
358  ErrorMessage = "Expected strings as key.";
359  return false;
360  }
361  SmallString<10> KeyStorage;
362  StringRef KeyValue = KeyString->getValue(KeyStorage);
363  llvm::yaml::Node *Value = NextKeyValue.getValue();
364  if (!Value) {
365  ErrorMessage = "Expected value.";
366  return false;
367  }
368  auto *ValueString = dyn_cast<llvm::yaml::ScalarNode>(Value);
369  auto *SequenceString = dyn_cast<llvm::yaml::SequenceNode>(Value);
370  if (KeyValue == "arguments") {
371  if (!SequenceString) {
372  ErrorMessage = "Expected sequence as value.";
373  return false;
374  }
375  Command = std::vector<llvm::yaml::ScalarNode *>();
376  for (auto &Argument : *SequenceString) {
377  auto *Scalar = dyn_cast<llvm::yaml::ScalarNode>(&Argument);
378  if (!Scalar) {
379  ErrorMessage = "Only strings are allowed in 'arguments'.";
380  return false;
381  }
382  Command->push_back(Scalar);
383  }
384  } else {
385  if (!ValueString) {
386  ErrorMessage = "Expected string as value.";
387  return false;
388  }
389  if (KeyValue == "directory") {
390  Directory = ValueString;
391  } else if (KeyValue == "command") {
392  if (!Command)
393  Command = std::vector<llvm::yaml::ScalarNode *>(1, ValueString);
394  } else if (KeyValue == "file") {
395  File = ValueString;
396  } else if (KeyValue == "output") {
397  Output = ValueString;
398  } else {
399  ErrorMessage =
400  ("Unknown key: \"" + KeyString->getRawValue() + "\"").str();
401  return false;
402  }
403  }
404  }
405  if (!File) {
406  ErrorMessage = "Missing key: \"file\".";
407  return false;
408  }
409  if (!Command) {
410  ErrorMessage = "Missing key: \"command\" or \"arguments\".";
411  return false;
412  }
413  if (!Directory) {
414  ErrorMessage = "Missing key: \"directory\".";
415  return false;
416  }
417  SmallString<8> FileStorage;
418  StringRef FileName = File->getValue(FileStorage);
419  SmallString<128> NativeFilePath;
420  if (llvm::sys::path::is_relative(FileName)) {
421  SmallString<8> DirectoryStorage;
422  SmallString<128> AbsolutePath(
423  Directory->getValue(DirectoryStorage));
424  llvm::sys::path::append(AbsolutePath, FileName);
425  llvm::sys::path::remove_dots(AbsolutePath, /*remove_dot_dot=*/ true);
426  llvm::sys::path::native(AbsolutePath, NativeFilePath);
427  } else {
428  llvm::sys::path::native(FileName, NativeFilePath);
429  }
430  auto Cmd = CompileCommandRef(Directory, File, *Command, Output);
431  IndexByFile[NativeFilePath].push_back(Cmd);
432  AllCommands.push_back(Cmd);
433  MatchTrie.insert(NativeFilePath);
434  }
435  return true;
436 }
clang::DeclaratorContext::File
@ File
Nodes
BoundNodesTreeBuilder Nodes
Definition: ASTMatchFinder.cpp:82
Error
llvm::Error Error
Definition: ByteCodeEmitter.cpp:20
clang::tooling::JSONCommandLineSyntax::Gnu
@ Gnu
string
string(SUBSTRING ${CMAKE_CURRENT_BINARY_DIR} 0 ${PATH_LIB_START} PATH_HEAD) string(SUBSTRING $
Definition: CMakeLists.txt:22
clang::tooling::expandResponseFiles
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...
Definition: ExpandResponseFilesCompilationDatabase.cpp:82
clang::tooling::JSONAnchorSource
volatile int JSONAnchorSource
Definition: JSONCompilationDatabase.cpp:187
llvm::SmallVector
Definition: LLVM.h:38
clang::tooling::JSONCompilationDatabase::getCompileCommands
std::vector< CompileCommand > getCompileCommands(StringRef FilePath) const override
Returns all compile commands in which the specified file was compiled.
Definition: JSONCompilationDatabase.cpp:226
llvm::Optional
Definition: LLVM.h:40
clang::tooling::X
static ToolExecutorPluginRegistry::Add< AllTUsToolExecutorPlugin > X("all-TUs", "Runs FrontendActions on all TUs in the compilation database. " "Tool results are stored in memory.")
clang::tooling::JSONCommandLineSyntax::Windows
@ Windows
getValue
static SVal getValue(SVal val, SValBuilder &svalBuilder)
Definition: ArrayBoundCheckerV2.cpp:277
clang::syntax::NodeRole::Object
@ Object
clang::tooling::JSONCompilationDatabase
Definition: JSONCompilationDatabase.h:61
Node
DynTypedNode Node
Definition: ASTMatchFinder.cpp:67
clang::tooling::JSONCompilationDatabase::loadFromBuffer
static std::unique_ptr< JSONCompilationDatabase > loadFromBuffer(StringRef DatabaseString, std::string &ErrorMessage, JSONCommandLineSyntax Syntax)
Loads a JSON compilation database from a data buffer.
Definition: JSONCompilationDatabase.cpp:213
clang::tooling::JSONCommandLineSyntax
JSONCommandLineSyntax
A JSON based compilation database.
Definition: JSONCompilationDatabase.h:60
clang::tooling::JSONCommandLineSyntax::AutoDetect
@ AutoDetect
JSONCompilationDatabase.h
llvm::SmallString
Definition: LLVM.h:37
CompilationDatabasePluginRegistry.h
clang::tooling::inferMissingCompileCommands
std::unique_ptr< CompilationDatabase > inferMissingCompileCommands(std::unique_ptr< CompilationDatabase >)
Returns a wrapped CompilationDatabase that defers to the provided one, but getCompileCommands() will ...
Definition: InterpolatingCompilationDatabase.cpp:541
Base
Cmd
CompileCommand Cmd
Definition: InterpolatingCompilationDatabase.cpp:130
Tooling.h
clang::tooling::JSONCompilationDatabase::loadFromFile
static std::unique_ptr< JSONCompilationDatabase > loadFromFile(StringRef FilePath, std::string &ErrorMessage, JSONCommandLineSyntax Syntax)
Loads a JSON compilation database from the specified file.
Definition: JSONCompilationDatabase.cpp:193
clang::tooling::FileMatchTrie::insert
void insert(StringRef NewPath)
Insert a new absolute path. Relative paths are ignored.
Definition: FileMatchTrie.cpp:192
llvm::ArrayRef
Definition: LLVM.h:34
Value
Value
Definition: UninitializedValues.cpp:102
LLVM.h
stripExecutableExtension
static llvm::StringRef stripExecutableExtension(llvm::StringRef Name)
Definition: JSONCompilationDatabase.cpp:258
clang::tooling::inferTargetAndDriverMode
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: GuessTargetAndModeCompilationDatabase.cpp:52
clang
Definition: CalledOnceCheck.h:17
unwrapCommand
static bool unwrapCommand(std::vector< std::string > &Args)
Definition: JSONCompilationDatabase.cpp:267
clang::tooling::JSONCompilationDatabase::getAllFiles
std::vector< std::string > getAllFiles() const override
Returns the list of all files available in the compilation database.
Definition: JSONCompilationDatabase.cpp:244
CompilationDatabase.h
nodeToCommandLine
static std::vector< std::string > nodeToCommandLine(JSONCommandLineSyntax Syntax, const std::vector< llvm::yaml::ScalarNode * > &Nodes)
Definition: JSONCompilationDatabase.cpp:298
clang::tooling::JSONCompilationDatabase::getAllCompileCommands
std::vector< CompileCommand > getAllCompileCommands() const override
Returns all compile commands for all the files in the compilation database.
Definition: JSONCompilationDatabase.cpp:252
clang::tooling::FileMatchTrie::findEquivalent
StringRef findEquivalent(StringRef FileName, raw_ostream &Error) const
Finds the corresponding file in this trie.
Definition: FileMatchTrie.cpp:196