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   const driver::ActionList &Actions = Compilation->getActions();
95   bool OffloadCompilation = false;
96   if (Jobs.size() > 1) {
97     for (auto A : Actions){
98       // On MacOSX real actions may end up being wrapped in BindArchAction
99       if (isa<driver::BindArchAction>(A))
100         A = *A->input_begin();
101       if (isa<driver::OffloadAction>(A)) {
102         // Offload compilation has 2 top-level actions, one (at the front) is
103         // the original host compilation and the other is offload action
104         // composed of at least one device compilation. For such case, general
105         // tooling will consider host-compilation only. For tooling on device
106         // compilation, device compilation only option, such as
107         // `--cuda-device-only`, needs specifying.
108         assert(Actions.size() > 1);
109         assert(
110             isa<driver::CompileJobAction>(Actions.front()) ||
111             // On MacOSX real actions may end up being wrapped in
112             // BindArchAction.
113             (isa<driver::BindArchAction>(Actions.front()) &&
114              isa<driver::CompileJobAction>(*Actions.front()->input_begin())));
115         OffloadCompilation = true;
116         break;
117       }
118     }
119   }
120   if (Jobs.size() == 0 || !isa<driver::Command>(*Jobs.begin()) ||
121       (Jobs.size() > 1 && !OffloadCompilation)) {
122     SmallString<256> error_msg;
123     llvm::raw_svector_ostream error_stream(error_msg);
124     Jobs.Print(error_stream, "; ", true);
125     Diagnostics->Report(diag::err_fe_expected_compiler_job)
126         << error_stream.str();
127     return nullptr;
128   }
129 
130   // The one job we find should be to invoke clang again.
131   const auto &Cmd = cast<driver::Command>(*Jobs.begin());
132   if (StringRef(Cmd.getCreator().getName()) != "clang") {
133     Diagnostics->Report(diag::err_fe_expected_clang_command);
134     return nullptr;
135   }
136 
137   return &Cmd.getArguments();
138 }
139 
140 namespace clang {
141 namespace tooling {
142 
143 /// Returns a clang build invocation initialized from the CC1 flags.
144 CompilerInvocation *newInvocation(
145     DiagnosticsEngine *Diagnostics, const llvm::opt::ArgStringList &CC1Args) {
146   assert(!CC1Args.empty() && "Must at least contain the program name!");
147   CompilerInvocation *Invocation = new CompilerInvocation;
148   CompilerInvocation::CreateFromArgs(*Invocation, CC1Args, *Diagnostics);
149   Invocation->getFrontendOpts().DisableFree = false;
150   Invocation->getCodeGenOpts().DisableFree = false;
151   return Invocation;
152 }
153 
154 bool runToolOnCode(std::unique_ptr<FrontendAction> ToolAction,
155                    const Twine &Code, const Twine &FileName,
156                    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
157   return runToolOnCodeWithArgs(std::move(ToolAction), Code,
158                                std::vector<std::string>(), FileName,
159                                "clang-tool", std::move(PCHContainerOps));
160 }
161 
162 } // namespace tooling
163 } // namespace clang
164 
165 static std::vector<std::string>
166 getSyntaxOnlyToolArgs(const Twine &ToolName,
167                       const std::vector<std::string> &ExtraArgs,
168                       StringRef FileName) {
169   std::vector<std::string> Args;
170   Args.push_back(ToolName.str());
171   Args.push_back("-fsyntax-only");
172   Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());
173   Args.push_back(FileName.str());
174   return Args;
175 }
176 
177 namespace clang {
178 namespace tooling {
179 
180 bool runToolOnCodeWithArgs(
181     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
182     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
183     const std::vector<std::string> &Args, const Twine &FileName,
184     const Twine &ToolName,
185     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
186   SmallString<16> FileNameStorage;
187   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
188 
189   llvm::IntrusiveRefCntPtr<FileManager> Files(
190       new FileManager(FileSystemOptions(), VFS));
191   ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();
192   ToolInvocation Invocation(
193       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
194       std::move(ToolAction), Files.get(), std::move(PCHContainerOps));
195   return Invocation.run();
196 }
197 
198 bool runToolOnCodeWithArgs(
199     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
200     const std::vector<std::string> &Args, const Twine &FileName,
201     const Twine &ToolName,
202     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
203     const FileContentMappings &VirtualMappedFiles) {
204   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
205       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
206   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
207       new llvm::vfs::InMemoryFileSystem);
208   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
209 
210   SmallString<1024> CodeStorage;
211   InMemoryFileSystem->addFile(FileName, 0,
212                               llvm::MemoryBuffer::getMemBuffer(
213                                   Code.toNullTerminatedStringRef(CodeStorage)));
214 
215   for (auto &FilenameWithContent : VirtualMappedFiles) {
216     InMemoryFileSystem->addFile(
217         FilenameWithContent.first, 0,
218         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
219   }
220 
221   return runToolOnCodeWithArgs(std::move(ToolAction), Code, OverlayFileSystem,
222                                Args, FileName, ToolName);
223 }
224 
225 llvm::Expected<std::string> getAbsolutePath(llvm::vfs::FileSystem &FS,
226                                             StringRef File) {
227   StringRef RelativePath(File);
228   // FIXME: Should '.\\' be accepted on Win32?
229   if (RelativePath.startswith("./")) {
230     RelativePath = RelativePath.substr(strlen("./"));
231   }
232 
233   SmallString<1024> AbsolutePath = RelativePath;
234   if (auto EC = FS.makeAbsolute(AbsolutePath))
235     return llvm::errorCodeToError(EC);
236   llvm::sys::path::native(AbsolutePath);
237   return AbsolutePath.str();
238 }
239 
240 std::string getAbsolutePath(StringRef File) {
241   return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));
242 }
243 
244 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
245                                     StringRef InvokedAs) {
246   if (!CommandLine.empty() && !InvokedAs.empty()) {
247     bool AlreadyHasTarget = false;
248     bool AlreadyHasMode = false;
249     // Skip CommandLine[0].
250     for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
251          ++Token) {
252       StringRef TokenRef(*Token);
253       AlreadyHasTarget |=
254           (TokenRef == "-target" || TokenRef.startswith("-target="));
255       AlreadyHasMode |= (TokenRef == "--driver-mode" ||
256                          TokenRef.startswith("--driver-mode="));
257     }
258     auto TargetMode =
259         driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
260     if (!AlreadyHasMode && TargetMode.DriverMode) {
261       CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
262     }
263     if (!AlreadyHasTarget && TargetMode.TargetIsValid) {
264       CommandLine.insert(++CommandLine.begin(), {"-target",
265                                                  TargetMode.TargetPrefix});
266     }
267   }
268 }
269 
270 } // namespace tooling
271 } // namespace clang
272 
273 namespace {
274 
275 class SingleFrontendActionFactory : public FrontendActionFactory {
276   std::unique_ptr<FrontendAction> Action;
277 
278 public:
279   SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)
280       : Action(std::move(Action)) {}
281 
282   std::unique_ptr<FrontendAction> create() override {
283     return std::move(Action);
284   }
285 };
286 
287 } // namespace
288 
289 ToolInvocation::ToolInvocation(
290     std::vector<std::string> CommandLine, ToolAction *Action,
291     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
292     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
293       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
294 
295 ToolInvocation::ToolInvocation(
296     std::vector<std::string> CommandLine,
297     std::unique_ptr<FrontendAction> FAction, FileManager *Files,
298     std::shared_ptr<PCHContainerOperations> PCHContainerOps)
299     : CommandLine(std::move(CommandLine)),
300       Action(new SingleFrontendActionFactory(std::move(FAction))),
301       OwnsAction(true), Files(Files),
302       PCHContainerOps(std::move(PCHContainerOps)) {}
303 
304 ToolInvocation::~ToolInvocation() {
305   if (OwnsAction)
306     delete Action;
307 }
308 
309 void ToolInvocation::mapVirtualFile(StringRef FilePath, StringRef Content) {
310   SmallString<1024> PathStorage;
311   llvm::sys::path::native(FilePath, PathStorage);
312   MappedFileContents[PathStorage] = Content;
313 }
314 
315 bool ToolInvocation::run() {
316   std::vector<const char*> Argv;
317   for (const std::string &Str : CommandLine)
318     Argv.push_back(Str.c_str());
319   const char *const BinaryName = Argv[0];
320   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
321   unsigned MissingArgIndex, MissingArgCount;
322   llvm::opt::InputArgList ParsedArgs = driver::getDriverOptTable().ParseArgs(
323       ArrayRef<const char *>(Argv).slice(1), MissingArgIndex, MissingArgCount);
324   ParseDiagnosticArgs(*DiagOpts, ParsedArgs);
325   TextDiagnosticPrinter DiagnosticPrinter(
326       llvm::errs(), &*DiagOpts);
327   DiagnosticsEngine Diagnostics(
328       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
329       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
330 
331   const std::unique_ptr<driver::Driver> Driver(
332       newDriver(&Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
333   // The "input file not found" diagnostics from the driver are useful.
334   // The driver is only aware of the VFS working directory, but some clients
335   // change this at the FileManager level instead.
336   // In this case the checks have false positives, so skip them.
337   if (!Files->getFileSystemOpts().WorkingDir.empty())
338     Driver->setCheckInputsExist(false);
339   const std::unique_ptr<driver::Compilation> Compilation(
340       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
341   if (!Compilation)
342     return false;
343   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
344       &Diagnostics, Compilation.get());
345   if (!CC1Args)
346     return false;
347   std::unique_ptr<CompilerInvocation> Invocation(
348       newInvocation(&Diagnostics, *CC1Args));
349   // FIXME: remove this when all users have migrated!
350   for (const auto &It : MappedFileContents) {
351     // Inject the code as the given file name into the preprocessor options.
352     std::unique_ptr<llvm::MemoryBuffer> Input =
353         llvm::MemoryBuffer::getMemBuffer(It.getValue());
354     Invocation->getPreprocessorOpts().addRemappedFile(It.getKey(),
355                                                       Input.release());
356   }
357   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
358                        std::move(PCHContainerOps));
359 }
360 
361 bool ToolInvocation::runInvocation(
362     const char *BinaryName, driver::Compilation *Compilation,
363     std::shared_ptr<CompilerInvocation> Invocation,
364     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
365   // Show the invocation, with -v.
366   if (Invocation->getHeaderSearchOpts().Verbose) {
367     llvm::errs() << "clang Invocation:\n";
368     Compilation->getJobs().Print(llvm::errs(), "\n", true);
369     llvm::errs() << "\n";
370   }
371 
372   return Action->runInvocation(std::move(Invocation), Files,
373                                std::move(PCHContainerOps), DiagConsumer);
374 }
375 
376 bool FrontendActionFactory::runInvocation(
377     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
378     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
379     DiagnosticConsumer *DiagConsumer) {
380   // Create a compiler instance to handle the actual work.
381   CompilerInstance Compiler(std::move(PCHContainerOps));
382   Compiler.setInvocation(std::move(Invocation));
383   Compiler.setFileManager(Files);
384 
385   // The FrontendAction can have lifetime requirements for Compiler or its
386   // members, and we need to ensure it's deleted earlier than Compiler. So we
387   // pass it to an std::unique_ptr declared after the Compiler variable.
388   std::unique_ptr<FrontendAction> ScopedToolAction(create());
389 
390   // Create the compiler's actual diagnostics engine.
391   Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
392   if (!Compiler.hasDiagnostics())
393     return false;
394 
395   Compiler.createSourceManager(*Files);
396 
397   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
398 
399   Files->clearStatCache();
400   return Success;
401 }
402 
403 ClangTool::ClangTool(const CompilationDatabase &Compilations,
404                      ArrayRef<std::string> SourcePaths,
405                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
406                      IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS,
407                      IntrusiveRefCntPtr<FileManager> Files)
408     : Compilations(Compilations), SourcePaths(SourcePaths),
409       PCHContainerOps(std::move(PCHContainerOps)),
410       OverlayFileSystem(new llvm::vfs::OverlayFileSystem(std::move(BaseFS))),
411       InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),
412       Files(Files ? Files
413                   : new FileManager(FileSystemOptions(), OverlayFileSystem)) {
414   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
415   appendArgumentsAdjuster(getClangStripOutputAdjuster());
416   appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());
417   appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
418   if (Files)
419     Files->setVirtualFileSystem(OverlayFileSystem);
420 }
421 
422 ClangTool::~ClangTool() = default;
423 
424 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
425   MappedFileContents.push_back(std::make_pair(FilePath, Content));
426 }
427 
428 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
429   ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));
430 }
431 
432 void ClangTool::clearArgumentsAdjusters() {
433   ArgsAdjuster = nullptr;
434 }
435 
436 static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
437                               void *MainAddr) {
438   // Allow users to override the resource dir.
439   for (StringRef Arg : Args)
440     if (Arg.startswith("-resource-dir"))
441       return;
442 
443   // If there's no override in place add our resource dir.
444   Args.push_back("-resource-dir=" +
445                  CompilerInvocation::GetResourcesPath(Argv0, MainAddr));
446 }
447 
448 int ClangTool::run(ToolAction *Action) {
449   // Exists solely for the purpose of lookup of the resource path.
450   // This just needs to be some symbol in the binary.
451   static int StaticSymbol;
452 
453   // First insert all absolute paths into the in-memory VFS. These are global
454   // for all compile commands.
455   if (SeenWorkingDirectories.insert("/").second)
456     for (const auto &MappedFile : MappedFileContents)
457       if (llvm::sys::path::is_absolute(MappedFile.first))
458         InMemoryFileSystem->addFile(
459             MappedFile.first, 0,
460             llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
461 
462   bool ProcessingFailed = false;
463   bool FileSkipped = false;
464   // Compute all absolute paths before we run any actions, as those will change
465   // the working directory.
466   std::vector<std::string> AbsolutePaths;
467   AbsolutePaths.reserve(SourcePaths.size());
468   for (const auto &SourcePath : SourcePaths) {
469     auto AbsPath = getAbsolutePath(*OverlayFileSystem, SourcePath);
470     if (!AbsPath) {
471       llvm::errs() << "Skipping " << SourcePath
472                    << ". Error while getting an absolute path: "
473                    << llvm::toString(AbsPath.takeError()) << "\n";
474       continue;
475     }
476     AbsolutePaths.push_back(std::move(*AbsPath));
477   }
478 
479   // Remember the working directory in case we need to restore it.
480   std::string InitialWorkingDir;
481   if (RestoreCWD) {
482     if (auto CWD = OverlayFileSystem->getCurrentWorkingDirectory()) {
483       InitialWorkingDir = std::move(*CWD);
484     } else {
485       llvm::errs() << "Could not get working directory: "
486                    << CWD.getError().message() << "\n";
487     }
488   }
489 
490   for (llvm::StringRef File : AbsolutePaths) {
491     // Currently implementations of CompilationDatabase::getCompileCommands can
492     // change the state of the file system (e.g.  prepare generated headers), so
493     // this method needs to run right before we invoke the tool, as the next
494     // file may require a different (incompatible) state of the file system.
495     //
496     // FIXME: Make the compilation database interface more explicit about the
497     // requirements to the order of invocation of its members.
498     std::vector<CompileCommand> CompileCommandsForFile =
499         Compilations.getCompileCommands(File);
500     if (CompileCommandsForFile.empty()) {
501       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
502       FileSkipped = true;
503       continue;
504     }
505     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
506       // FIXME: chdir is thread hostile; on the other hand, creating the same
507       // behavior as chdir is complex: chdir resolves the path once, thus
508       // guaranteeing that all subsequent relative path operations work
509       // on the same path the original chdir resulted in. This makes a
510       // difference for example on network filesystems, where symlinks might be
511       // switched during runtime of the tool. Fixing this depends on having a
512       // file system abstraction that allows openat() style interactions.
513       if (OverlayFileSystem->setCurrentWorkingDirectory(
514               CompileCommand.Directory))
515         llvm::report_fatal_error("Cannot chdir into \"" +
516                                  Twine(CompileCommand.Directory) + "\"!");
517 
518       // Now fill the in-memory VFS with the relative file mappings so it will
519       // have the correct relative paths. We never remove mappings but that
520       // should be fine.
521       if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)
522         for (const auto &MappedFile : MappedFileContents)
523           if (!llvm::sys::path::is_absolute(MappedFile.first))
524             InMemoryFileSystem->addFile(
525                 MappedFile.first, 0,
526                 llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
527 
528       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
529       if (ArgsAdjuster)
530         CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);
531       assert(!CommandLine.empty());
532 
533       // Add the resource dir based on the binary of this tool. argv[0] in the
534       // compilation database may refer to a different compiler and we want to
535       // pick up the very same standard library that compiler is using. The
536       // builtin headers in the resource dir need to match the exact clang
537       // version the tool is using.
538       // FIXME: On linux, GetMainExecutable is independent of the value of the
539       // first argument, thus allowing ClangTool and runToolOnCode to just
540       // pass in made-up names here. Make sure this works on other platforms.
541       injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);
542 
543       // FIXME: We need a callback mechanism for the tool writer to output a
544       // customized message for each file.
545       LLVM_DEBUG({ llvm::dbgs() << "Processing: " << File << ".\n"; });
546       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),
547                                 PCHContainerOps);
548       Invocation.setDiagnosticConsumer(DiagConsumer);
549 
550       if (!Invocation.run()) {
551         // FIXME: Diagnostics should be used instead.
552         if (PrintErrorMessage)
553           llvm::errs() << "Error while processing " << File << ".\n";
554         ProcessingFailed = true;
555       }
556     }
557   }
558 
559   if (!InitialWorkingDir.empty()) {
560     if (auto EC =
561             OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))
562       llvm::errs() << "Error when trying to restore working dir: "
563                    << EC.message() << "\n";
564   }
565   return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);
566 }
567 
568 namespace {
569 
570 class ASTBuilderAction : public ToolAction {
571   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
572 
573 public:
574   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
575 
576   bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
577                      FileManager *Files,
578                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
579                      DiagnosticConsumer *DiagConsumer) override {
580     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
581         Invocation, std::move(PCHContainerOps),
582         CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts(),
583                                             DiagConsumer,
584                                             /*ShouldOwnClient=*/false),
585         Files);
586     if (!AST)
587       return false;
588 
589     ASTs.push_back(std::move(AST));
590     return true;
591   }
592 };
593 
594 } // namespace
595 
596 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
597   ASTBuilderAction Action(ASTs);
598   return run(&Action);
599 }
600 
601 void ClangTool::setRestoreWorkingDir(bool RestoreCWD) {
602   this->RestoreCWD = RestoreCWD;
603 }
604 
605 void ClangTool::setPrintErrorMessage(bool PrintErrorMessage) {
606   this->PrintErrorMessage = PrintErrorMessage;
607 }
608 
609 namespace clang {
610 namespace tooling {
611 
612 std::unique_ptr<ASTUnit>
613 buildASTFromCode(StringRef Code, StringRef FileName,
614                  std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
615   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,
616                                   "clang-tool", std::move(PCHContainerOps));
617 }
618 
619 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
620     StringRef Code, const std::vector<std::string> &Args, StringRef FileName,
621     StringRef ToolName, std::shared_ptr<PCHContainerOperations> PCHContainerOps,
622     ArgumentsAdjuster Adjuster, const FileContentMappings &VirtualMappedFiles) {
623   std::vector<std::unique_ptr<ASTUnit>> ASTs;
624   ASTBuilderAction Action(ASTs);
625   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
626       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
627   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
628       new llvm::vfs::InMemoryFileSystem);
629   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
630   llvm::IntrusiveRefCntPtr<FileManager> Files(
631       new FileManager(FileSystemOptions(), OverlayFileSystem));
632 
633   ToolInvocation Invocation(
634       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),
635       &Action, Files.get(), std::move(PCHContainerOps));
636 
637   InMemoryFileSystem->addFile(FileName, 0,
638                               llvm::MemoryBuffer::getMemBufferCopy(Code));
639   for (auto &FilenameWithContent : VirtualMappedFiles) {
640     InMemoryFileSystem->addFile(
641         FilenameWithContent.first, 0,
642         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
643   }
644 
645   if (!Invocation.run())
646     return nullptr;
647 
648   assert(ASTs.size() == 1);
649   return std::move(ASTs[0]);
650 }
651 
652 } // namespace tooling
653 } // namespace clang
654