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