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