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, "clang LLVM compiler", 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(DiagnosticsEngine *Diagnostics,
145                                   const llvm::opt::ArgStringList &CC1Args,
146                                   const char *const BinaryName) {
147   assert(!CC1Args.empty() && "Must at least contain the program name!");
148   CompilerInvocation *Invocation = new CompilerInvocation;
149   CompilerInvocation::CreateFromArgs(*Invocation, CC1Args, *Diagnostics,
150                                      BinaryName);
151   Invocation->getFrontendOpts().DisableFree = false;
152   Invocation->getCodeGenOpts().DisableFree = false;
153   return Invocation;
154 }
155 
156 bool runToolOnCode(std::unique_ptr<FrontendAction> ToolAction,
157                    const Twine &Code, const Twine &FileName,
158                    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
159   return runToolOnCodeWithArgs(std::move(ToolAction), Code,
160                                std::vector<std::string>(), FileName,
161                                "clang-tool", std::move(PCHContainerOps));
162 }
163 
164 } // namespace tooling
165 } // namespace clang
166 
167 static std::vector<std::string>
168 getSyntaxOnlyToolArgs(const Twine &ToolName,
169                       const std::vector<std::string> &ExtraArgs,
170                       StringRef FileName) {
171   std::vector<std::string> Args;
172   Args.push_back(ToolName.str());
173   Args.push_back("-fsyntax-only");
174   Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());
175   Args.push_back(FileName.str());
176   return Args;
177 }
178 
179 namespace clang {
180 namespace tooling {
181 
182 bool runToolOnCodeWithArgs(
183     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
184     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
185     const std::vector<std::string> &Args, const Twine &FileName,
186     const Twine &ToolName,
187     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
188   SmallString<16> FileNameStorage;
189   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
190 
191   llvm::IntrusiveRefCntPtr<FileManager> Files(
192       new FileManager(FileSystemOptions(), VFS));
193   ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();
194   ToolInvocation Invocation(
195       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
196       std::move(ToolAction), Files.get(), std::move(PCHContainerOps));
197   return Invocation.run();
198 }
199 
200 bool runToolOnCodeWithArgs(
201     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
202     const std::vector<std::string> &Args, const Twine &FileName,
203     const Twine &ToolName,
204     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
205     const FileContentMappings &VirtualMappedFiles) {
206   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
207       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
208   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
209       new llvm::vfs::InMemoryFileSystem);
210   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
211 
212   SmallString<1024> CodeStorage;
213   InMemoryFileSystem->addFile(FileName, 0,
214                               llvm::MemoryBuffer::getMemBuffer(
215                                   Code.toNullTerminatedStringRef(CodeStorage)));
216 
217   for (auto &FilenameWithContent : VirtualMappedFiles) {
218     InMemoryFileSystem->addFile(
219         FilenameWithContent.first, 0,
220         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
221   }
222 
223   return runToolOnCodeWithArgs(std::move(ToolAction), Code, OverlayFileSystem,
224                                Args, FileName, ToolName);
225 }
226 
227 llvm::Expected<std::string> getAbsolutePath(llvm::vfs::FileSystem &FS,
228                                             StringRef File) {
229   StringRef RelativePath(File);
230   // FIXME: Should '.\\' be accepted on Win32?
231   if (RelativePath.startswith("./")) {
232     RelativePath = RelativePath.substr(strlen("./"));
233   }
234 
235   SmallString<1024> AbsolutePath = RelativePath;
236   if (auto EC = FS.makeAbsolute(AbsolutePath))
237     return llvm::errorCodeToError(EC);
238   llvm::sys::path::native(AbsolutePath);
239   return std::string(AbsolutePath.str());
240 }
241 
242 std::string getAbsolutePath(StringRef File) {
243   return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));
244 }
245 
246 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
247                                     StringRef InvokedAs) {
248   if (CommandLine.empty() || InvokedAs.empty())
249     return;
250   const auto &Table = driver::getDriverOptTable();
251   // --target=X
252   const std::string TargetOPT =
253       Table.getOption(driver::options::OPT_target).getPrefixedName();
254   // -target X
255   const std::string TargetOPTLegacy =
256       Table.getOption(driver::options::OPT_target_legacy_spelling)
257           .getPrefixedName();
258   // --driver-mode=X
259   const std::string DriverModeOPT =
260       Table.getOption(driver::options::OPT_driver_mode).getPrefixedName();
261   auto TargetMode =
262       driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
263   // No need to search for target args if we don't have a target/mode to insert.
264   bool ShouldAddTarget = TargetMode.TargetIsValid;
265   bool ShouldAddMode = TargetMode.DriverMode != nullptr;
266   // Skip CommandLine[0].
267   for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
268        ++Token) {
269     StringRef TokenRef(*Token);
270     ShouldAddTarget = ShouldAddTarget && !TokenRef.startswith(TargetOPT) &&
271                       !TokenRef.equals(TargetOPTLegacy);
272     ShouldAddMode = ShouldAddMode && !TokenRef.startswith(DriverModeOPT);
273   }
274   if (ShouldAddMode) {
275     CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
276   }
277   if (ShouldAddTarget) {
278     CommandLine.insert(++CommandLine.begin(),
279                        TargetOPT + TargetMode.TargetPrefix);
280   }
281 }
282 
283 } // namespace tooling
284 } // namespace clang
285 
286 namespace {
287 
288 class SingleFrontendActionFactory : public FrontendActionFactory {
289   std::unique_ptr<FrontendAction> Action;
290 
291 public:
292   SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)
293       : Action(std::move(Action)) {}
294 
295   std::unique_ptr<FrontendAction> create() override {
296     return std::move(Action);
297   }
298 };
299 
300 } // namespace
301 
302 ToolInvocation::ToolInvocation(
303     std::vector<std::string> CommandLine, ToolAction *Action,
304     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
305     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
306       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
307 
308 ToolInvocation::ToolInvocation(
309     std::vector<std::string> CommandLine,
310     std::unique_ptr<FrontendAction> FAction, FileManager *Files,
311     std::shared_ptr<PCHContainerOperations> PCHContainerOps)
312     : CommandLine(std::move(CommandLine)),
313       Action(new SingleFrontendActionFactory(std::move(FAction))),
314       OwnsAction(true), Files(Files),
315       PCHContainerOps(std::move(PCHContainerOps)) {}
316 
317 ToolInvocation::~ToolInvocation() {
318   if (OwnsAction)
319     delete Action;
320 }
321 
322 bool ToolInvocation::run() {
323   std::vector<const char*> Argv;
324   for (const std::string &Str : CommandLine)
325     Argv.push_back(Str.c_str());
326   const char *const BinaryName = Argv[0];
327   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
328   unsigned MissingArgIndex, MissingArgCount;
329   llvm::opt::InputArgList ParsedArgs = driver::getDriverOptTable().ParseArgs(
330       ArrayRef<const char *>(Argv).slice(1), MissingArgIndex, MissingArgCount);
331   ParseDiagnosticArgs(*DiagOpts, ParsedArgs);
332   TextDiagnosticPrinter DiagnosticPrinter(
333       llvm::errs(), &*DiagOpts);
334   DiagnosticsEngine Diagnostics(
335       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
336       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
337 
338   const std::unique_ptr<driver::Driver> Driver(
339       newDriver(&Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
340   // The "input file not found" diagnostics from the driver are useful.
341   // The driver is only aware of the VFS working directory, but some clients
342   // change this at the FileManager level instead.
343   // In this case the checks have false positives, so skip them.
344   if (!Files->getFileSystemOpts().WorkingDir.empty())
345     Driver->setCheckInputsExist(false);
346   const std::unique_ptr<driver::Compilation> Compilation(
347       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
348   if (!Compilation)
349     return false;
350   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
351       &Diagnostics, Compilation.get());
352   if (!CC1Args)
353     return false;
354   std::unique_ptr<CompilerInvocation> Invocation(
355       newInvocation(&Diagnostics, *CC1Args, BinaryName));
356   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
357                        std::move(PCHContainerOps));
358 }
359 
360 bool ToolInvocation::runInvocation(
361     const char *BinaryName, driver::Compilation *Compilation,
362     std::shared_ptr<CompilerInvocation> Invocation,
363     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
364   // Show the invocation, with -v.
365   if (Invocation->getHeaderSearchOpts().Verbose) {
366     llvm::errs() << "clang Invocation:\n";
367     Compilation->getJobs().Print(llvm::errs(), "\n", true);
368     llvm::errs() << "\n";
369   }
370 
371   return Action->runInvocation(std::move(Invocation), Files,
372                                std::move(PCHContainerOps), DiagConsumer);
373 }
374 
375 bool FrontendActionFactory::runInvocation(
376     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
377     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
378     DiagnosticConsumer *DiagConsumer) {
379   // Create a compiler instance to handle the actual work.
380   CompilerInstance Compiler(std::move(PCHContainerOps));
381   Compiler.setInvocation(std::move(Invocation));
382   Compiler.setFileManager(Files);
383 
384   // The FrontendAction can have lifetime requirements for Compiler or its
385   // members, and we need to ensure it's deleted earlier than Compiler. So we
386   // pass it to an std::unique_ptr declared after the Compiler variable.
387   std::unique_ptr<FrontendAction> ScopedToolAction(create());
388 
389   // Create the compiler's actual diagnostics engine.
390   Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
391   if (!Compiler.hasDiagnostics())
392     return false;
393 
394   Compiler.createSourceManager(*Files);
395 
396   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
397 
398   Files->clearStatCache();
399   return Success;
400 }
401 
402 ClangTool::ClangTool(const CompilationDatabase &Compilations,
403                      ArrayRef<std::string> SourcePaths,
404                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
405                      IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS,
406                      IntrusiveRefCntPtr<FileManager> Files)
407     : Compilations(Compilations), SourcePaths(SourcePaths),
408       PCHContainerOps(std::move(PCHContainerOps)),
409       OverlayFileSystem(new llvm::vfs::OverlayFileSystem(std::move(BaseFS))),
410       InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),
411       Files(Files ? Files
412                   : new FileManager(FileSystemOptions(), OverlayFileSystem)) {
413   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
414   appendArgumentsAdjuster(getClangStripOutputAdjuster());
415   appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());
416   appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
417   if (Files)
418     Files->setVirtualFileSystem(OverlayFileSystem);
419 }
420 
421 ClangTool::~ClangTool() = default;
422 
423 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
424   MappedFileContents.push_back(std::make_pair(FilePath, Content));
425 }
426 
427 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
428   ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));
429 }
430 
431 void ClangTool::clearArgumentsAdjusters() {
432   ArgsAdjuster = nullptr;
433 }
434 
435 static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
436                               void *MainAddr) {
437   // Allow users to override the resource dir.
438   for (StringRef Arg : Args)
439     if (Arg.startswith("-resource-dir"))
440       return;
441 
442   // If there's no override in place add our resource dir.
443   Args = getInsertArgumentAdjuster(
444       ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))
445           .c_str())(Args, "");
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     DiagnosticConsumer *DiagConsumer) {
624   std::vector<std::unique_ptr<ASTUnit>> ASTs;
625   ASTBuilderAction Action(ASTs);
626   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
627       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
628   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
629       new llvm::vfs::InMemoryFileSystem);
630   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
631   llvm::IntrusiveRefCntPtr<FileManager> Files(
632       new FileManager(FileSystemOptions(), OverlayFileSystem));
633 
634   ToolInvocation Invocation(
635       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),
636       &Action, Files.get(), std::move(PCHContainerOps));
637   Invocation.setDiagnosticConsumer(DiagConsumer);
638 
639   InMemoryFileSystem->addFile(FileName, 0,
640                               llvm::MemoryBuffer::getMemBufferCopy(Code));
641   for (auto &FilenameWithContent : VirtualMappedFiles) {
642     InMemoryFileSystem->addFile(
643         FilenameWithContent.first, 0,
644         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
645   }
646 
647   if (!Invocation.run())
648     return nullptr;
649 
650   assert(ASTs.size() == 1);
651   return std::move(ASTs[0]);
652 }
653 
654 } // namespace tooling
655 } // namespace clang
656