1 //===- Tooling.cpp - Running clang standalone tools -----------------------===//
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 implements functions to run clang tools standalone instead
11 //  of running them as a plugin.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Tooling/Tooling.h"
16 #include "clang/Basic/Diagnostic.h"
17 #include "clang/Basic/DiagnosticIDs.h"
18 #include "clang/Basic/DiagnosticOptions.h"
19 #include "clang/Basic/FileManager.h"
20 #include "clang/Basic/FileSystemOptions.h"
21 #include "clang/Basic/LLVM.h"
22 #include "clang/Basic/VirtualFileSystem.h"
23 #include "clang/Driver/Compilation.h"
24 #include "clang/Driver/Driver.h"
25 #include "clang/Driver/Job.h"
26 #include "clang/Driver/Options.h"
27 #include "clang/Driver/Tool.h"
28 #include "clang/Driver/ToolChain.h"
29 #include "clang/Frontend/ASTUnit.h"
30 #include "clang/Frontend/CompilerInstance.h"
31 #include "clang/Frontend/CompilerInvocation.h"
32 #include "clang/Frontend/FrontendDiagnostic.h"
33 #include "clang/Frontend/FrontendOptions.h"
34 #include "clang/Frontend/TextDiagnosticPrinter.h"
35 #include "clang/Lex/HeaderSearchOptions.h"
36 #include "clang/Lex/PreprocessorOptions.h"
37 #include "clang/Tooling/ArgumentsAdjusters.h"
38 #include "clang/Tooling/CompilationDatabase.h"
39 #include "llvm/ADT/ArrayRef.h"
40 #include "llvm/ADT/IntrusiveRefCntPtr.h"
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/StringRef.h"
43 #include "llvm/ADT/Twine.h"
44 #include "llvm/Option/ArgList.h"
45 #include "llvm/Option/OptTable.h"
46 #include "llvm/Option/Option.h"
47 #include "llvm/Support/Casting.h"
48 #include "llvm/Support/Debug.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/FileSystem.h"
51 #include "llvm/Support/Host.h"
52 #include "llvm/Support/MemoryBuffer.h"
53 #include "llvm/Support/Path.h"
54 #include "llvm/Support/raw_ostream.h"
55 #include <cassert>
56 #include <cstring>
57 #include <memory>
58 #include <string>
59 #include <system_error>
60 #include <utility>
61 #include <vector>
62 
63 #define DEBUG_TYPE "clang-tooling"
64 
65 using namespace clang;
66 using namespace tooling;
67 
68 ToolAction::~ToolAction() = default;
69 
70 FrontendActionFactory::~FrontendActionFactory() = default;
71 
72 // FIXME: This file contains structural duplication with other parts of the
73 // code that sets up a compiler to run tools on it, and we should refactor
74 // it to be based on the same framework.
75 
76 /// Builds a clang driver initialized for running clang tools.
77 static driver::Driver *newDriver(
78     DiagnosticsEngine *Diagnostics, const char *BinaryName,
79     IntrusiveRefCntPtr<vfs::FileSystem> VFS) {
80   driver::Driver *CompilerDriver =
81       new driver::Driver(BinaryName, llvm::sys::getDefaultTargetTriple(),
82                          *Diagnostics, std::move(VFS));
83   CompilerDriver->setTitle("clang_based_tool");
84   return CompilerDriver;
85 }
86 
87 /// Retrieves the clang CC1 specific flags out of the compilation's jobs.
88 ///
89 /// Returns nullptr on error.
90 static const llvm::opt::ArgStringList *getCC1Arguments(
91     DiagnosticsEngine *Diagnostics, driver::Compilation *Compilation) {
92   // We expect to get back exactly one Command job, if we didn't something
93   // failed. Extract that job from the Compilation.
94   const driver::JobList &Jobs = Compilation->getJobs();
95   if (Jobs.size() != 1 || !isa<driver::Command>(*Jobs.begin())) {
96     SmallString<256> error_msg;
97     llvm::raw_svector_ostream error_stream(error_msg);
98     Jobs.Print(error_stream, "; ", true);
99     Diagnostics->Report(diag::err_fe_expected_compiler_job)
100         << error_stream.str();
101     return nullptr;
102   }
103 
104   // The one job we find should be to invoke clang again.
105   const auto &Cmd = cast<driver::Command>(*Jobs.begin());
106   if (StringRef(Cmd.getCreator().getName()) != "clang") {
107     Diagnostics->Report(diag::err_fe_expected_clang_command);
108     return nullptr;
109   }
110 
111   return &Cmd.getArguments();
112 }
113 
114 namespace clang {
115 namespace tooling {
116 
117 /// Returns a clang build invocation initialized from the CC1 flags.
118 CompilerInvocation *newInvocation(
119     DiagnosticsEngine *Diagnostics, const llvm::opt::ArgStringList &CC1Args) {
120   assert(!CC1Args.empty() && "Must at least contain the program name!");
121   CompilerInvocation *Invocation = new CompilerInvocation;
122   CompilerInvocation::CreateFromArgs(
123       *Invocation, CC1Args.data() + 1, CC1Args.data() + CC1Args.size(),
124       *Diagnostics);
125   Invocation->getFrontendOpts().DisableFree = false;
126   Invocation->getCodeGenOpts().DisableFree = false;
127   return Invocation;
128 }
129 
130 bool runToolOnCode(FrontendAction *ToolAction, const Twine &Code,
131                    const Twine &FileName,
132                    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
133   return runToolOnCodeWithArgs(ToolAction, Code, std::vector<std::string>(),
134                                FileName, "clang-tool",
135                                std::move(PCHContainerOps));
136 }
137 
138 } // namespace tooling
139 } // namespace clang
140 
141 static std::vector<std::string>
142 getSyntaxOnlyToolArgs(const Twine &ToolName,
143                       const std::vector<std::string> &ExtraArgs,
144                       StringRef FileName) {
145   std::vector<std::string> Args;
146   Args.push_back(ToolName.str());
147   Args.push_back("-fsyntax-only");
148   Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());
149   Args.push_back(FileName.str());
150   return Args;
151 }
152 
153 namespace clang {
154 namespace tooling {
155 
156 bool runToolOnCodeWithArgs(
157     FrontendAction *ToolAction, const Twine &Code,
158     llvm::IntrusiveRefCntPtr<vfs::FileSystem> VFS,
159     const std::vector<std::string> &Args, const Twine &FileName,
160     const Twine &ToolName,
161     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
162   SmallString<16> FileNameStorage;
163   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
164 
165   llvm::IntrusiveRefCntPtr<FileManager> Files(
166       new FileManager(FileSystemOptions(), VFS));
167   ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();
168   ToolInvocation Invocation(
169       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
170       ToolAction, Files.get(),
171       std::move(PCHContainerOps));
172   return Invocation.run();
173 }
174 
175 bool runToolOnCodeWithArgs(
176     FrontendAction *ToolAction, const Twine &Code,
177     const std::vector<std::string> &Args, const Twine &FileName,
178     const Twine &ToolName,
179     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
180     const FileContentMappings &VirtualMappedFiles) {
181   llvm::IntrusiveRefCntPtr<vfs::OverlayFileSystem> OverlayFileSystem(
182       new vfs::OverlayFileSystem(vfs::getRealFileSystem()));
183   llvm::IntrusiveRefCntPtr<vfs::InMemoryFileSystem> InMemoryFileSystem(
184       new vfs::InMemoryFileSystem);
185   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
186 
187   SmallString<1024> CodeStorage;
188   InMemoryFileSystem->addFile(FileName, 0,
189                               llvm::MemoryBuffer::getMemBuffer(
190                                   Code.toNullTerminatedStringRef(CodeStorage)));
191 
192   for (auto &FilenameWithContent : VirtualMappedFiles) {
193     InMemoryFileSystem->addFile(
194         FilenameWithContent.first, 0,
195         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
196   }
197 
198   return runToolOnCodeWithArgs(ToolAction, Code, OverlayFileSystem, Args,
199                                FileName, ToolName);
200 }
201 
202 llvm::Expected<std::string> getAbsolutePath(vfs::FileSystem &FS,
203                                             StringRef File) {
204   StringRef RelativePath(File);
205   // FIXME: Should '.\\' be accepted on Win32?
206   if (RelativePath.startswith("./")) {
207     RelativePath = RelativePath.substr(strlen("./"));
208   }
209 
210   SmallString<1024> AbsolutePath = RelativePath;
211   if (auto EC = FS.makeAbsolute(AbsolutePath))
212     return llvm::errorCodeToError(EC);
213   llvm::sys::path::native(AbsolutePath);
214   return AbsolutePath.str();
215 }
216 
217 std::string getAbsolutePath(StringRef File) {
218   return llvm::cantFail(getAbsolutePath(*vfs::getRealFileSystem(), File));
219 }
220 
221 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
222                                     StringRef InvokedAs) {
223   if (!CommandLine.empty() && !InvokedAs.empty()) {
224     bool AlreadyHasTarget = false;
225     bool AlreadyHasMode = false;
226     // Skip CommandLine[0].
227     for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
228          ++Token) {
229       StringRef TokenRef(*Token);
230       AlreadyHasTarget |=
231           (TokenRef == "-target" || TokenRef.startswith("-target="));
232       AlreadyHasMode |= (TokenRef == "--driver-mode" ||
233                          TokenRef.startswith("--driver-mode="));
234     }
235     auto TargetMode =
236         driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
237     if (!AlreadyHasMode && TargetMode.DriverMode) {
238       CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
239     }
240     if (!AlreadyHasTarget && TargetMode.TargetIsValid) {
241       CommandLine.insert(++CommandLine.begin(), {"-target",
242                                                  TargetMode.TargetPrefix});
243     }
244   }
245 }
246 
247 } // namespace tooling
248 } // namespace clang
249 
250 namespace {
251 
252 class SingleFrontendActionFactory : public FrontendActionFactory {
253   FrontendAction *Action;
254 
255 public:
256   SingleFrontendActionFactory(FrontendAction *Action) : Action(Action) {}
257 
258   FrontendAction *create() override { return Action; }
259 };
260 
261 } // namespace
262 
263 ToolInvocation::ToolInvocation(
264     std::vector<std::string> CommandLine, ToolAction *Action,
265     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
266     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
267       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
268 
269 ToolInvocation::ToolInvocation(
270     std::vector<std::string> CommandLine, FrontendAction *FAction,
271     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
272     : CommandLine(std::move(CommandLine)),
273       Action(new SingleFrontendActionFactory(FAction)), OwnsAction(true),
274       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
275 
276 ToolInvocation::~ToolInvocation() {
277   if (OwnsAction)
278     delete Action;
279 }
280 
281 void ToolInvocation::mapVirtualFile(StringRef FilePath, StringRef Content) {
282   SmallString<1024> PathStorage;
283   llvm::sys::path::native(FilePath, PathStorage);
284   MappedFileContents[PathStorage] = Content;
285 }
286 
287 bool ToolInvocation::run() {
288   std::vector<const char*> Argv;
289   for (const std::string &Str : CommandLine)
290     Argv.push_back(Str.c_str());
291   const char *const BinaryName = Argv[0];
292   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
293   unsigned MissingArgIndex, MissingArgCount;
294   std::unique_ptr<llvm::opt::OptTable> Opts = driver::createDriverOptTable();
295   llvm::opt::InputArgList ParsedArgs = Opts->ParseArgs(
296       ArrayRef<const char *>(Argv).slice(1), MissingArgIndex, MissingArgCount);
297   ParseDiagnosticArgs(*DiagOpts, ParsedArgs);
298   TextDiagnosticPrinter DiagnosticPrinter(
299       llvm::errs(), &*DiagOpts);
300   DiagnosticsEngine Diagnostics(
301       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
302       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
303 
304   const std::unique_ptr<driver::Driver> Driver(
305       newDriver(&Diagnostics, BinaryName, Files->getVirtualFileSystem()));
306   // Since the input might only be virtual, don't check whether it exists.
307   Driver->setCheckInputsExist(false);
308   const std::unique_ptr<driver::Compilation> Compilation(
309       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
310   if (!Compilation)
311     return false;
312   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
313       &Diagnostics, Compilation.get());
314   if (!CC1Args)
315     return false;
316   std::unique_ptr<CompilerInvocation> Invocation(
317       newInvocation(&Diagnostics, *CC1Args));
318   // FIXME: remove this when all users have migrated!
319   for (const auto &It : MappedFileContents) {
320     // Inject the code as the given file name into the preprocessor options.
321     std::unique_ptr<llvm::MemoryBuffer> Input =
322         llvm::MemoryBuffer::getMemBuffer(It.getValue());
323     Invocation->getPreprocessorOpts().addRemappedFile(It.getKey(),
324                                                       Input.release());
325   }
326   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
327                        std::move(PCHContainerOps));
328 }
329 
330 bool ToolInvocation::runInvocation(
331     const char *BinaryName, driver::Compilation *Compilation,
332     std::shared_ptr<CompilerInvocation> Invocation,
333     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
334   // Show the invocation, with -v.
335   if (Invocation->getHeaderSearchOpts().Verbose) {
336     llvm::errs() << "clang Invocation:\n";
337     Compilation->getJobs().Print(llvm::errs(), "\n", true);
338     llvm::errs() << "\n";
339   }
340 
341   return Action->runInvocation(std::move(Invocation), Files,
342                                std::move(PCHContainerOps), DiagConsumer);
343 }
344 
345 bool FrontendActionFactory::runInvocation(
346     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
347     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
348     DiagnosticConsumer *DiagConsumer) {
349   // Create a compiler instance to handle the actual work.
350   CompilerInstance Compiler(std::move(PCHContainerOps));
351   Compiler.setInvocation(std::move(Invocation));
352   Compiler.setFileManager(Files);
353 
354   // The FrontendAction can have lifetime requirements for Compiler or its
355   // members, and we need to ensure it's deleted earlier than Compiler. So we
356   // pass it to an std::unique_ptr declared after the Compiler variable.
357   std::unique_ptr<FrontendAction> ScopedToolAction(create());
358 
359   // Create the compiler's actual diagnostics engine.
360   Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
361   if (!Compiler.hasDiagnostics())
362     return false;
363 
364   Compiler.createSourceManager(*Files);
365 
366   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
367 
368   Files->clearStatCaches();
369   return Success;
370 }
371 
372 ClangTool::ClangTool(const CompilationDatabase &Compilations,
373                      ArrayRef<std::string> SourcePaths,
374                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
375                      IntrusiveRefCntPtr<vfs::FileSystem> BaseFS)
376     : Compilations(Compilations), SourcePaths(SourcePaths),
377       PCHContainerOps(std::move(PCHContainerOps)),
378       OverlayFileSystem(new vfs::OverlayFileSystem(std::move(BaseFS))),
379       InMemoryFileSystem(new vfs::InMemoryFileSystem),
380       Files(new FileManager(FileSystemOptions(), OverlayFileSystem)) {
381   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
382   appendArgumentsAdjuster(getClangStripOutputAdjuster());
383   appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());
384   appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
385 }
386 
387 ClangTool::~ClangTool() = default;
388 
389 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
390   MappedFileContents.push_back(std::make_pair(FilePath, Content));
391 }
392 
393 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
394   ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));
395 }
396 
397 void ClangTool::clearArgumentsAdjusters() {
398   ArgsAdjuster = nullptr;
399 }
400 
401 static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
402                               void *MainAddr) {
403   // Allow users to override the resource dir.
404   for (StringRef Arg : Args)
405     if (Arg.startswith("-resource-dir"))
406       return;
407 
408   // If there's no override in place add our resource dir.
409   Args.push_back("-resource-dir=" +
410                  CompilerInvocation::GetResourcesPath(Argv0, MainAddr));
411 }
412 
413 int ClangTool::run(ToolAction *Action) {
414   // Exists solely for the purpose of lookup of the resource path.
415   // This just needs to be some symbol in the binary.
416   static int StaticSymbol;
417 
418   // First insert all absolute paths into the in-memory VFS. These are global
419   // for all compile commands.
420   if (SeenWorkingDirectories.insert("/").second)
421     for (const auto &MappedFile : MappedFileContents)
422       if (llvm::sys::path::is_absolute(MappedFile.first))
423         InMemoryFileSystem->addFile(
424             MappedFile.first, 0,
425             llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
426 
427   bool ProcessingFailed = false;
428   bool FileSkipped = false;
429   // Compute all absolute paths before we run any actions, as those will change
430   // the working directory.
431   std::vector<std::string> AbsolutePaths;
432   AbsolutePaths.reserve(SourcePaths.size());
433   for (const auto &SourcePath : SourcePaths) {
434     auto AbsPath = getAbsolutePath(*OverlayFileSystem, SourcePath);
435     if (!AbsPath) {
436       llvm::errs() << "Skipping " << SourcePath
437                    << ". Error while getting an absolute path: "
438                    << llvm::toString(AbsPath.takeError()) << "\n";
439       continue;
440     }
441     AbsolutePaths.push_back(std::move(*AbsPath));
442   }
443 
444   // Remember the working directory in case we need to restore it.
445   std::string InitialWorkingDir;
446   if (RestoreCWD) {
447     if (auto CWD = OverlayFileSystem->getCurrentWorkingDirectory()) {
448       InitialWorkingDir = std::move(*CWD);
449     } else {
450       llvm::errs() << "Could not get working directory: "
451                    << CWD.getError().message() << "\n";
452     }
453   }
454 
455   for (llvm::StringRef File : AbsolutePaths) {
456     // Currently implementations of CompilationDatabase::getCompileCommands can
457     // change the state of the file system (e.g.  prepare generated headers), so
458     // this method needs to run right before we invoke the tool, as the next
459     // file may require a different (incompatible) state of the file system.
460     //
461     // FIXME: Make the compilation database interface more explicit about the
462     // requirements to the order of invocation of its members.
463     std::vector<CompileCommand> CompileCommandsForFile =
464         Compilations.getCompileCommands(File);
465     if (CompileCommandsForFile.empty()) {
466       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
467       FileSkipped = true;
468       continue;
469     }
470     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
471       // FIXME: chdir is thread hostile; on the other hand, creating the same
472       // behavior as chdir is complex: chdir resolves the path once, thus
473       // guaranteeing that all subsequent relative path operations work
474       // on the same path the original chdir resulted in. This makes a
475       // difference for example on network filesystems, where symlinks might be
476       // switched during runtime of the tool. Fixing this depends on having a
477       // file system abstraction that allows openat() style interactions.
478       if (OverlayFileSystem->setCurrentWorkingDirectory(
479               CompileCommand.Directory))
480         llvm::report_fatal_error("Cannot chdir into \"" +
481                                  Twine(CompileCommand.Directory) + "\n!");
482 
483       // Now fill the in-memory VFS with the relative file mappings so it will
484       // have the correct relative paths. We never remove mappings but that
485       // should be fine.
486       if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)
487         for (const auto &MappedFile : MappedFileContents)
488           if (!llvm::sys::path::is_absolute(MappedFile.first))
489             InMemoryFileSystem->addFile(
490                 MappedFile.first, 0,
491                 llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
492 
493       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
494       if (ArgsAdjuster)
495         CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);
496       assert(!CommandLine.empty());
497 
498       // Add the resource dir based on the binary of this tool. argv[0] in the
499       // compilation database may refer to a different compiler and we want to
500       // pick up the very same standard library that compiler is using. The
501       // builtin headers in the resource dir need to match the exact clang
502       // version the tool is using.
503       // FIXME: On linux, GetMainExecutable is independent of the value of the
504       // first argument, thus allowing ClangTool and runToolOnCode to just
505       // pass in made-up names here. Make sure this works on other platforms.
506       injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);
507 
508       // FIXME: We need a callback mechanism for the tool writer to output a
509       // customized message for each file.
510       LLVM_DEBUG({ llvm::dbgs() << "Processing: " << File << ".\n"; });
511       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),
512                                 PCHContainerOps);
513       Invocation.setDiagnosticConsumer(DiagConsumer);
514 
515       if (!Invocation.run()) {
516         // FIXME: Diagnostics should be used instead.
517         llvm::errs() << "Error while processing " << File << ".\n";
518         ProcessingFailed = true;
519       }
520     }
521   }
522 
523   if (!InitialWorkingDir.empty()) {
524     if (auto EC =
525             OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))
526       llvm::errs() << "Error when trying to restore working dir: "
527                    << EC.message() << "\n";
528   }
529   return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);
530 }
531 
532 namespace {
533 
534 class ASTBuilderAction : public ToolAction {
535   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
536 
537 public:
538   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
539 
540   bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
541                      FileManager *Files,
542                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
543                      DiagnosticConsumer *DiagConsumer) override {
544     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
545         Invocation, std::move(PCHContainerOps),
546         CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts(),
547                                             DiagConsumer,
548                                             /*ShouldOwnClient=*/false),
549         Files);
550     if (!AST)
551       return false;
552 
553     ASTs.push_back(std::move(AST));
554     return true;
555   }
556 };
557 
558 } // namespace
559 
560 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
561   ASTBuilderAction Action(ASTs);
562   return run(&Action);
563 }
564 
565 void ClangTool::setRestoreWorkingDir(bool RestoreCWD) {
566   this->RestoreCWD = RestoreCWD;
567 }
568 
569 namespace clang {
570 namespace tooling {
571 
572 std::unique_ptr<ASTUnit>
573 buildASTFromCode(const Twine &Code, const Twine &FileName,
574                  std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
575   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,
576                                   "clang-tool", std::move(PCHContainerOps));
577 }
578 
579 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
580     const Twine &Code, const std::vector<std::string> &Args,
581     const Twine &FileName, const Twine &ToolName,
582     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
583     ArgumentsAdjuster Adjuster) {
584   SmallString<16> FileNameStorage;
585   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
586 
587   std::vector<std::unique_ptr<ASTUnit>> ASTs;
588   ASTBuilderAction Action(ASTs);
589   llvm::IntrusiveRefCntPtr<vfs::OverlayFileSystem> OverlayFileSystem(
590       new vfs::OverlayFileSystem(vfs::getRealFileSystem()));
591   llvm::IntrusiveRefCntPtr<vfs::InMemoryFileSystem> InMemoryFileSystem(
592       new vfs::InMemoryFileSystem);
593   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
594   llvm::IntrusiveRefCntPtr<FileManager> Files(
595       new FileManager(FileSystemOptions(), OverlayFileSystem));
596 
597   ToolInvocation Invocation(
598       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
599       &Action, Files.get(), std::move(PCHContainerOps));
600 
601   SmallString<1024> CodeStorage;
602   InMemoryFileSystem->addFile(FileNameRef, 0,
603                               llvm::MemoryBuffer::getMemBuffer(
604                                   Code.toNullTerminatedStringRef(CodeStorage)));
605   if (!Invocation.run())
606     return nullptr;
607 
608   assert(ASTs.size() == 1);
609   return std::move(ASTs[0]);
610 }
611 
612 } // namespace tooling
613 } // namespace clang
614