clang  13.0.0git
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) {
139  llvm::Triple Triple(llvm::sys::getProcessTriple());
140  if (Triple.getOS() == llvm::Triple::OSType::Win32) {
141  // Assume Windows command line parsing on Win32 unless the triple
142  // explicitly tells us otherwise.
143  if (!Triple.hasEnvironment() ||
144  Triple.getEnvironment() == llvm::Triple::EnvironmentType::MSVC)
146  }
147  }
148 
149  if (Syntax == JSONCommandLineSyntax::Windows) {
150  llvm::BumpPtrAllocator Alloc;
151  llvm::StringSaver Saver(Alloc);
153  llvm::cl::TokenizeWindowsCommandLine(EscapedCommandLine, Saver, T);
154  std::vector<std::string> Result(T.begin(), T.end());
155  return Result;
156  }
157  assert(Syntax == JSONCommandLineSyntax::Gnu);
158  CommandLineArgumentParser parser(EscapedCommandLine);
159  return parser.parse();
160 }
161 
162 // This plugin locates a nearby compile_command.json file, and also infers
163 // compile commands for files not present in the database.
164 class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {
165  std::unique_ptr<CompilationDatabase>
166  loadFromDirectory(StringRef Directory, std::string &ErrorMessage) override {
167  SmallString<1024> JSONDatabasePath(Directory);
168  llvm::sys::path::append(JSONDatabasePath, "compile_commands.json");
170  JSONDatabasePath, ErrorMessage, JSONCommandLineSyntax::AutoDetect);
173  std::move(Base), llvm::vfs::getRealFileSystem())))
174  : nullptr;
175  }
176 };
177 
178 } // namespace
179 
180 // Register the JSONCompilationDatabasePlugin with the
181 // CompilationDatabasePluginRegistry using this statically initialized variable.
182 static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin>
183 X("json-compilation-database", "Reads JSON formatted compilation databases");
184 
185 namespace clang {
186 namespace tooling {
187 
188 // This anchor is used to force the linker to link in the generated object file
189 // and thus register the JSONCompilationDatabasePlugin.
190 volatile int JSONAnchorSource = 0;
191 
192 } // namespace tooling
193 } // namespace clang
194 
195 std::unique_ptr<JSONCompilationDatabase>
197  std::string &ErrorMessage,
198  JSONCommandLineSyntax Syntax) {
199  // Don't mmap: if we're a long-lived process, the build system may overwrite.
200  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> DatabaseBuffer =
201  llvm::MemoryBuffer::getFile(FilePath, /*FileSize=*/-1,
202  /*RequiresNullTerminator=*/true,
203  /*IsVolatile=*/true);
204  if (std::error_code Result = DatabaseBuffer.getError()) {
205  ErrorMessage = "Error while opening JSON database: " + Result.message();
206  return nullptr;
207  }
208  std::unique_ptr<JSONCompilationDatabase> Database(
209  new JSONCompilationDatabase(std::move(*DatabaseBuffer), Syntax));
210  if (!Database->parse(ErrorMessage))
211  return nullptr;
212  return Database;
213 }
214 
215 std::unique_ptr<JSONCompilationDatabase>
217  std::string &ErrorMessage,
218  JSONCommandLineSyntax Syntax) {
219  std::unique_ptr<llvm::MemoryBuffer> DatabaseBuffer(
220  llvm::MemoryBuffer::getMemBufferCopy(DatabaseString));
221  std::unique_ptr<JSONCompilationDatabase> Database(
222  new JSONCompilationDatabase(std::move(DatabaseBuffer), Syntax));
223  if (!Database->parse(ErrorMessage))
224  return nullptr;
225  return Database;
226 }
227 
228 std::vector<CompileCommand>
230  SmallString<128> NativeFilePath;
231  llvm::sys::path::native(FilePath, NativeFilePath);
232 
233  std::string Error;
234  llvm::raw_string_ostream ES(Error);
235  StringRef Match = MatchTrie.findEquivalent(NativeFilePath, ES);
236  if (Match.empty())
237  return {};
238  const auto CommandsRefI = IndexByFile.find(Match);
239  if (CommandsRefI == IndexByFile.end())
240  return {};
241  std::vector<CompileCommand> Commands;
242  getCommands(CommandsRefI->getValue(), Commands);
243  return Commands;
244 }
245 
246 std::vector<std::string>
248  std::vector<std::string> Result;
249  for (const auto &CommandRef : IndexByFile)
250  Result.push_back(CommandRef.first().str());
251  return Result;
252 }
253 
254 std::vector<CompileCommand>
256  std::vector<CompileCommand> Commands;
257  getCommands(AllCommands, Commands);
258  return Commands;
259 }
260 
261 static llvm::StringRef stripExecutableExtension(llvm::StringRef Name) {
262  Name.consume_back(".exe");
263  return Name;
264 }
265 
266 // There are compiler-wrappers (ccache, distcc, gomacc) that take the "real"
267 // compiler as an argument, e.g. distcc gcc -O3 foo.c.
268 // These end up in compile_commands.json when people set CC="distcc gcc".
269 // Clang's driver doesn't understand this, so we need to unwrap.
270 static bool unwrapCommand(std::vector<std::string> &Args) {
271  if (Args.size() < 2)
272  return false;
273  StringRef Wrapper =
274  stripExecutableExtension(llvm::sys::path::filename(Args.front()));
275  if (Wrapper == "distcc" || Wrapper == "gomacc" || Wrapper == "ccache" ||
276  Wrapper == "sccache") {
277  // Most of these wrappers support being invoked 3 ways:
278  // `distcc g++ file.c` This is the mode we're trying to match.
279  // We need to drop `distcc`.
280  // `distcc file.c` This acts like compiler is cc or similar.
281  // Clang's driver can handle this, no change needed.
282  // `g++ file.c` g++ is a symlink to distcc.
283  // We don't even notice this case, and all is well.
284  //
285  // We need to distinguish between the first and second case.
286  // The wrappers themselves don't take flags, so Args[1] is a compiler flag,
287  // an input file, or a compiler. Inputs have extensions, compilers don't.
288  bool HasCompiler =
289  (Args[1][0] != '-') &&
290  !llvm::sys::path::has_extension(stripExecutableExtension(Args[1]));
291  if (HasCompiler) {
292  Args.erase(Args.begin());
293  return true;
294  }
295  // If !HasCompiler, wrappers act like GCC. Fine: so do we.
296  }
297  return false;
298 }
299 
300 static std::vector<std::string>
302  const std::vector<llvm::yaml::ScalarNode *> &Nodes) {
303  SmallString<1024> Storage;
304  std::vector<std::string> Arguments;
305  if (Nodes.size() == 1)
306  Arguments = unescapeCommandLine(Syntax, Nodes[0]->getValue(Storage));
307  else
308  for (const auto *Node : Nodes)
309  Arguments.push_back(std::string(Node->getValue(Storage)));
310  // There may be multiple wrappers: using distcc and ccache together is common.
311  while (unwrapCommand(Arguments))
312  ;
313  return Arguments;
314 }
315 
316 void JSONCompilationDatabase::getCommands(
317  ArrayRef<CompileCommandRef> CommandsRef,
318  std::vector<CompileCommand> &Commands) const {
319  for (const auto &CommandRef : CommandsRef) {
320  SmallString<8> DirectoryStorage;
321  SmallString<32> FilenameStorage;
322  SmallString<32> OutputStorage;
323  auto Output = std::get<3>(CommandRef);
324  Commands.emplace_back(
325  std::get<0>(CommandRef)->getValue(DirectoryStorage),
326  std::get<1>(CommandRef)->getValue(FilenameStorage),
327  nodeToCommandLine(Syntax, std::get<2>(CommandRef)),
328  Output ? Output->getValue(OutputStorage) : "");
329  }
330 }
331 
332 bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
333  llvm::yaml::document_iterator I = YAMLStream.begin();
334  if (I == YAMLStream.end()) {
335  ErrorMessage = "Error while parsing YAML.";
336  return false;
337  }
338  llvm::yaml::Node *Root = I->getRoot();
339  if (!Root) {
340  ErrorMessage = "Error while parsing YAML.";
341  return false;
342  }
343  auto *Array = dyn_cast<llvm::yaml::SequenceNode>(Root);
344  if (!Array) {
345  ErrorMessage = "Expected array.";
346  return false;
347  }
348  for (auto &NextObject : *Array) {
349  auto *Object = dyn_cast<llvm::yaml::MappingNode>(&NextObject);
350  if (!Object) {
351  ErrorMessage = "Expected object.";
352  return false;
353  }
354  llvm::yaml::ScalarNode *Directory = nullptr;
356  llvm::yaml::ScalarNode *File = nullptr;
357  llvm::yaml::ScalarNode *Output = nullptr;
358  for (auto& NextKeyValue : *Object) {
359  auto *KeyString = dyn_cast<llvm::yaml::ScalarNode>(NextKeyValue.getKey());
360  if (!KeyString) {
361  ErrorMessage = "Expected strings as key.";
362  return false;
363  }
364  SmallString<10> KeyStorage;
365  StringRef KeyValue = KeyString->getValue(KeyStorage);
366  llvm::yaml::Node *Value = NextKeyValue.getValue();
367  if (!Value) {
368  ErrorMessage = "Expected value.";
369  return false;
370  }
371  auto *ValueString = dyn_cast<llvm::yaml::ScalarNode>(Value);
372  auto *SequenceString = dyn_cast<llvm::yaml::SequenceNode>(Value);
373  if (KeyValue == "arguments") {
374  if (!SequenceString) {
375  ErrorMessage = "Expected sequence as value.";
376  return false;
377  }
378  Command = std::vector<llvm::yaml::ScalarNode *>();
379  for (auto &Argument : *SequenceString) {
380  auto *Scalar = dyn_cast<llvm::yaml::ScalarNode>(&Argument);
381  if (!Scalar) {
382  ErrorMessage = "Only strings are allowed in 'arguments'.";
383  return false;
384  }
385  Command->push_back(Scalar);
386  }
387  } else {
388  if (!ValueString) {
389  ErrorMessage = "Expected string as value.";
390  return false;
391  }
392  if (KeyValue == "directory") {
393  Directory = ValueString;
394  } else if (KeyValue == "command") {
395  if (!Command)
396  Command = std::vector<llvm::yaml::ScalarNode *>(1, ValueString);
397  } else if (KeyValue == "file") {
398  File = ValueString;
399  } else if (KeyValue == "output") {
400  Output = ValueString;
401  } else {
402  ErrorMessage =
403  ("Unknown key: \"" + KeyString->getRawValue() + "\"").str();
404  return false;
405  }
406  }
407  }
408  if (!File) {
409  ErrorMessage = "Missing key: \"file\".";
410  return false;
411  }
412  if (!Command) {
413  ErrorMessage = "Missing key: \"command\" or \"arguments\".";
414  return false;
415  }
416  if (!Directory) {
417  ErrorMessage = "Missing key: \"directory\".";
418  return false;
419  }
420  SmallString<8> FileStorage;
421  StringRef FileName = File->getValue(FileStorage);
422  SmallString<128> NativeFilePath;
423  if (llvm::sys::path::is_relative(FileName)) {
424  SmallString<8> DirectoryStorage;
425  SmallString<128> AbsolutePath(
426  Directory->getValue(DirectoryStorage));
427  llvm::sys::path::append(AbsolutePath, FileName);
428  llvm::sys::path::remove_dots(AbsolutePath, /*remove_dot_dot=*/ true);
429  llvm::sys::path::native(AbsolutePath, NativeFilePath);
430  } else {
431  llvm::sys::path::native(FileName, NativeFilePath);
432  }
433  auto Cmd = CompileCommandRef(Directory, File, *Command, Output);
434  IndexByFile[NativeFilePath].push_back(Cmd);
435  AllCommands.push_back(Cmd);
436  MatchTrie.insert(NativeFilePath);
437  }
438  return true;
439 }
clang::DeclaratorContext::File
@ File
Nodes
BoundNodesTreeBuilder Nodes
Definition: ASTMatchFinder.cpp:82
Error
llvm::Error Error
Definition: ByteCodeEmitter.cpp:19
clang::tooling::JSONCommandLineSyntax::Gnu
@ Gnu
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:81
clang::tooling::JSONAnchorSource
volatile int JSONAnchorSource
Definition: JSONCompilationDatabase.cpp:190
llvm::SmallVector
Definition: LLVM.h:35
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:229
llvm::Optional
Definition: LLVM.h:37
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:216
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:34
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:543
Base
Cmd
CompileCommand Cmd
Definition: InterpolatingCompilationDatabase.cpp:128
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:196
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:31
Value
Value
Definition: UninitializedValues.cpp:102
LLVM.h
stripExecutableExtension
static llvm::StringRef stripExecutableExtension(llvm::StringRef Name)
Definition: JSONCompilationDatabase.cpp:261
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
Dataflow Directional Tag Classes.
Definition: CalledOnceCheck.h:17
unwrapCommand
static bool unwrapCommand(std::vector< std::string > &Args)
Definition: JSONCompilationDatabase.cpp:270
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:247
CompilationDatabase.h
nodeToCommandLine
static std::vector< std::string > nodeToCommandLine(JSONCommandLineSyntax Syntax, const std::vector< llvm::yaml::ScalarNode * > &Nodes)
Definition: JSONCompilationDatabase.cpp:301
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:255
clang::tooling::FileMatchTrie::findEquivalent
StringRef findEquivalent(StringRef FileName, raw_ostream &Error) const
Finds the corresponding file in this trie.
Definition: FileMatchTrie.cpp:196