xref: /freebsd/contrib/llvm-project/clang/lib/Tooling/Tooling.cpp (revision e64bea71c21eb42e97aa615188ba91f6cce0d36d)
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/StringRef.h"
40 #include "llvm/ADT/Twine.h"
41 #include "llvm/Option/ArgList.h"
42 #include "llvm/Option/OptTable.h"
43 #include "llvm/Option/Option.h"
44 #include "llvm/Support/CommandLine.h"
45 #include "llvm/Support/Debug.h"
46 #include "llvm/Support/ErrorHandling.h"
47 #include "llvm/Support/MemoryBuffer.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/VirtualFileSystem.h"
50 #include "llvm/Support/raw_ostream.h"
51 #include "llvm/TargetParser/Host.h"
52 #include <cassert>
53 #include <cstring>
54 #include <memory>
55 #include <string>
56 #include <system_error>
57 #include <utility>
58 #include <vector>
59 
60 #define DEBUG_TYPE "clang-tooling"
61 
62 using namespace clang;
63 using namespace tooling;
64 
65 ToolAction::~ToolAction() = default;
66 
67 FrontendActionFactory::~FrontendActionFactory() = default;
68 
69 // FIXME: This file contains structural duplication with other parts of the
70 // code that sets up a compiler to run tools on it, and we should refactor
71 // it to be based on the same framework.
72 
73 /// Builds a clang driver initialized for running clang tools.
74 static driver::Driver *
75 newDriver(DiagnosticsEngine *Diagnostics, const char *BinaryName,
76           IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
77   driver::Driver *CompilerDriver =
78       new driver::Driver(BinaryName, llvm::sys::getDefaultTargetTriple(),
79                          *Diagnostics, "clang LLVM compiler", std::move(VFS));
80   CompilerDriver->setTitle("clang_based_tool");
81   return CompilerDriver;
82 }
83 
84 /// Decide whether extra compiler frontend commands can be ignored.
85 static bool ignoreExtraCC1Commands(const driver::Compilation *Compilation) {
86   const driver::JobList &Jobs = Compilation->getJobs();
87   const driver::ActionList &Actions = Compilation->getActions();
88 
89   bool OffloadCompilation = false;
90 
91   // Jobs and Actions look very different depending on whether the Clang tool
92   // injected -fsyntax-only or not. Try to handle both cases here.
93 
94   for (const auto &Job : Jobs)
95     if (StringRef(Job.getExecutable()) == "clang-offload-bundler")
96       OffloadCompilation = true;
97 
98   if (Jobs.size() > 1) {
99     for (auto *A : Actions){
100       // On MacOSX real actions may end up being wrapped in BindArchAction
101       if (isa<driver::BindArchAction>(A))
102         A = *A->input_begin();
103       if (isa<driver::OffloadAction>(A)) {
104         // Offload compilation has 2 top-level actions, one (at the front) is
105         // the original host compilation and the other is offload action
106         // composed of at least one device compilation. For such case, general
107         // tooling will consider host-compilation only. For tooling on device
108         // compilation, device compilation only option, such as
109         // `--cuda-device-only`, needs specifying.
110         assert(Actions.size() > 1);
111         assert(
112             isa<driver::CompileJobAction>(Actions.front()) ||
113             // On MacOSX real actions may end up being wrapped in
114             // BindArchAction.
115             (isa<driver::BindArchAction>(Actions.front()) &&
116              isa<driver::CompileJobAction>(*Actions.front()->input_begin())));
117         OffloadCompilation = true;
118         break;
119       }
120     }
121   }
122 
123   return OffloadCompilation;
124 }
125 
126 namespace clang {
127 namespace tooling {
128 
129 const llvm::opt::ArgStringList *
130 getCC1Arguments(DiagnosticsEngine *Diagnostics,
131                 driver::Compilation *Compilation) {
132   const driver::JobList &Jobs = Compilation->getJobs();
133 
134   auto IsCC1Command = [](const driver::Command &Cmd) {
135     return StringRef(Cmd.getCreator().getName()) == "clang";
136   };
137 
138   auto IsSrcFile = [](const driver::InputInfo &II) {
139     return isSrcFile(II.getType());
140   };
141 
142   llvm::SmallVector<const driver::Command *, 1> CC1Jobs;
143   for (const driver::Command &Job : Jobs)
144     if (IsCC1Command(Job) && llvm::all_of(Job.getInputInfos(), IsSrcFile))
145       CC1Jobs.push_back(&Job);
146 
147   // If there are no jobs for source files, try checking again for a single job
148   // with any file type. This accepts a preprocessed file as input.
149   if (CC1Jobs.empty())
150     for (const driver::Command &Job : Jobs)
151       if (IsCC1Command(Job))
152         CC1Jobs.push_back(&Job);
153 
154   if (CC1Jobs.empty() ||
155       (CC1Jobs.size() > 1 && !ignoreExtraCC1Commands(Compilation))) {
156     SmallString<256> error_msg;
157     llvm::raw_svector_ostream error_stream(error_msg);
158     Jobs.Print(error_stream, "; ", true);
159     Diagnostics->Report(diag::err_fe_expected_compiler_job)
160         << error_stream.str();
161     return nullptr;
162   }
163 
164   return &CC1Jobs[0]->getArguments();
165 }
166 
167 /// Returns a clang build invocation initialized from the CC1 flags.
168 CompilerInvocation *newInvocation(DiagnosticsEngine *Diagnostics,
169                                   ArrayRef<const char *> CC1Args,
170                                   const char *const BinaryName) {
171   assert(!CC1Args.empty() && "Must at least contain the program name!");
172   CompilerInvocation *Invocation = new CompilerInvocation;
173   CompilerInvocation::CreateFromArgs(*Invocation, CC1Args, *Diagnostics,
174                                      BinaryName);
175   Invocation->getFrontendOpts().DisableFree = false;
176   Invocation->getCodeGenOpts().DisableFree = false;
177   return Invocation;
178 }
179 
180 bool runToolOnCode(std::unique_ptr<FrontendAction> ToolAction,
181                    const Twine &Code, const Twine &FileName,
182                    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
183   return runToolOnCodeWithArgs(std::move(ToolAction), Code,
184                                std::vector<std::string>(), FileName,
185                                "clang-tool", std::move(PCHContainerOps));
186 }
187 
188 } // namespace tooling
189 } // namespace clang
190 
191 static std::vector<std::string>
192 getSyntaxOnlyToolArgs(const Twine &ToolName,
193                       const std::vector<std::string> &ExtraArgs,
194                       StringRef FileName) {
195   std::vector<std::string> Args;
196   Args.push_back(ToolName.str());
197   Args.push_back("-fsyntax-only");
198   llvm::append_range(Args, ExtraArgs);
199   Args.push_back(FileName.str());
200   return Args;
201 }
202 
203 namespace clang {
204 namespace tooling {
205 
206 bool runToolOnCodeWithArgs(
207     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
208     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
209     const std::vector<std::string> &Args, const Twine &FileName,
210     const Twine &ToolName,
211     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
212   SmallString<16> FileNameStorage;
213   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
214 
215   llvm::IntrusiveRefCntPtr<FileManager> Files(
216       new FileManager(FileSystemOptions(), VFS));
217   ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();
218   ToolInvocation Invocation(
219       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
220       std::move(ToolAction), Files.get(), std::move(PCHContainerOps));
221   return Invocation.run();
222 }
223 
224 bool runToolOnCodeWithArgs(
225     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
226     const std::vector<std::string> &Args, const Twine &FileName,
227     const Twine &ToolName,
228     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
229     const FileContentMappings &VirtualMappedFiles) {
230   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
231       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
232   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
233       new llvm::vfs::InMemoryFileSystem);
234   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
235 
236   SmallString<1024> CodeStorage;
237   InMemoryFileSystem->addFile(FileName, 0,
238                               llvm::MemoryBuffer::getMemBuffer(
239                                   Code.toNullTerminatedStringRef(CodeStorage)));
240 
241   for (auto &FilenameWithContent : VirtualMappedFiles) {
242     InMemoryFileSystem->addFile(
243         FilenameWithContent.first, 0,
244         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
245   }
246 
247   return runToolOnCodeWithArgs(std::move(ToolAction), Code, OverlayFileSystem,
248                                Args, FileName, ToolName);
249 }
250 
251 llvm::Expected<std::string> getAbsolutePath(llvm::vfs::FileSystem &FS,
252                                             StringRef File) {
253   StringRef RelativePath(File);
254   // FIXME: Should '.\\' be accepted on Win32?
255   RelativePath.consume_front("./");
256 
257   SmallString<1024> AbsolutePath = RelativePath;
258   if (auto EC = FS.makeAbsolute(AbsolutePath))
259     return llvm::errorCodeToError(EC);
260   llvm::sys::path::native(AbsolutePath);
261   return std::string(AbsolutePath);
262 }
263 
264 std::string getAbsolutePath(StringRef File) {
265   return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));
266 }
267 
268 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
269                                     StringRef InvokedAs) {
270   if (CommandLine.empty() || InvokedAs.empty())
271     return;
272   const auto &Table = driver::getDriverOptTable();
273   // --target=X
274   StringRef TargetOPT =
275       Table.getOption(driver::options::OPT_target).getPrefixedName();
276   // -target X
277   StringRef TargetOPTLegacy =
278       Table.getOption(driver::options::OPT_target_legacy_spelling)
279           .getPrefixedName();
280   // --driver-mode=X
281   StringRef DriverModeOPT =
282       Table.getOption(driver::options::OPT_driver_mode).getPrefixedName();
283   auto TargetMode =
284       driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
285   // No need to search for target args if we don't have a target/mode to insert.
286   bool ShouldAddTarget = TargetMode.TargetIsValid;
287   bool ShouldAddMode = TargetMode.DriverMode != nullptr;
288   // Skip CommandLine[0].
289   for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
290        ++Token) {
291     StringRef TokenRef(*Token);
292     ShouldAddTarget = ShouldAddTarget && !TokenRef.starts_with(TargetOPT) &&
293                       TokenRef != TargetOPTLegacy;
294     ShouldAddMode = ShouldAddMode && !TokenRef.starts_with(DriverModeOPT);
295   }
296   if (ShouldAddMode) {
297     CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
298   }
299   if (ShouldAddTarget) {
300     CommandLine.insert(++CommandLine.begin(),
301                        (TargetOPT + TargetMode.TargetPrefix).str());
302   }
303 }
304 
305 void addExpandedResponseFiles(std::vector<std::string> &CommandLine,
306                               llvm::StringRef WorkingDir,
307                               llvm::cl::TokenizerCallback Tokenizer,
308                               llvm::vfs::FileSystem &FS) {
309   bool SeenRSPFile = false;
310   llvm::SmallVector<const char *, 20> Argv;
311   Argv.reserve(CommandLine.size());
312   for (auto &Arg : CommandLine) {
313     Argv.push_back(Arg.c_str());
314     if (!Arg.empty())
315       SeenRSPFile |= Arg.front() == '@';
316   }
317   if (!SeenRSPFile)
318     return;
319   llvm::BumpPtrAllocator Alloc;
320   llvm::cl::ExpansionContext ECtx(Alloc, Tokenizer);
321   llvm::Error Err =
322       ECtx.setVFS(&FS).setCurrentDir(WorkingDir).expandResponseFiles(Argv);
323   if (Err)
324     llvm::errs() << Err;
325   // Don't assign directly, Argv aliases CommandLine.
326   std::vector<std::string> ExpandedArgv(Argv.begin(), Argv.end());
327   CommandLine = std::move(ExpandedArgv);
328 }
329 
330 } // namespace tooling
331 } // namespace clang
332 
333 namespace {
334 
335 class SingleFrontendActionFactory : public FrontendActionFactory {
336   std::unique_ptr<FrontendAction> Action;
337 
338 public:
339   SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)
340       : Action(std::move(Action)) {}
341 
342   std::unique_ptr<FrontendAction> create() override {
343     return std::move(Action);
344   }
345 };
346 
347 } // namespace
348 
349 ToolInvocation::ToolInvocation(
350     std::vector<std::string> CommandLine, ToolAction *Action,
351     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
352     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
353       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
354 
355 ToolInvocation::ToolInvocation(
356     std::vector<std::string> CommandLine,
357     std::unique_ptr<FrontendAction> FAction, FileManager *Files,
358     std::shared_ptr<PCHContainerOperations> PCHContainerOps)
359     : CommandLine(std::move(CommandLine)),
360       Action(new SingleFrontendActionFactory(std::move(FAction))),
361       OwnsAction(true), Files(Files),
362       PCHContainerOps(std::move(PCHContainerOps)) {}
363 
364 ToolInvocation::~ToolInvocation() {
365   if (OwnsAction)
366     delete Action;
367 }
368 
369 bool ToolInvocation::run() {
370   llvm::opt::ArgStringList Argv;
371   for (const std::string &Str : CommandLine)
372     Argv.push_back(Str.c_str());
373   const char *const BinaryName = Argv[0];
374 
375   // Parse diagnostic options from the driver command-line only if none were
376   // explicitly set.
377   std::unique_ptr<DiagnosticOptions> ParsedDiagOpts;
378   DiagnosticOptions *DiagOpts = this->DiagOpts;
379   if (!DiagOpts) {
380     ParsedDiagOpts = CreateAndPopulateDiagOpts(Argv);
381     DiagOpts = &*ParsedDiagOpts;
382   }
383 
384   TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), *DiagOpts);
385   IntrusiveRefCntPtr<DiagnosticsEngine> Diagnostics =
386       CompilerInstance::createDiagnostics(
387           Files->getVirtualFileSystem(), *DiagOpts,
388           DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
389   // Although `Diagnostics` are used only for command-line parsing, the custom
390   // `DiagConsumer` might expect a `SourceManager` to be present.
391   SourceManager SrcMgr(*Diagnostics, *Files);
392   Diagnostics->setSourceManager(&SrcMgr);
393 
394   // We already have a cc1, just create an invocation.
395   if (CommandLine.size() >= 2 && CommandLine[1] == "-cc1") {
396     ArrayRef<const char *> CC1Args = ArrayRef(Argv).drop_front();
397     std::unique_ptr<CompilerInvocation> Invocation(
398         newInvocation(&*Diagnostics, CC1Args, BinaryName));
399     if (Diagnostics->hasErrorOccurred())
400       return false;
401     return Action->runInvocation(std::move(Invocation), Files,
402                                  std::move(PCHContainerOps), DiagConsumer);
403   }
404 
405   const std::unique_ptr<driver::Driver> Driver(
406       newDriver(&*Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
407   // The "input file not found" diagnostics from the driver are useful.
408   // The driver is only aware of the VFS working directory, but some clients
409   // change this at the FileManager level instead.
410   // In this case the checks have false positives, so skip them.
411   if (!Files->getFileSystemOpts().WorkingDir.empty())
412     Driver->setCheckInputsExist(false);
413   const std::unique_ptr<driver::Compilation> Compilation(
414       Driver->BuildCompilation(llvm::ArrayRef(Argv)));
415   if (!Compilation)
416     return false;
417   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
418       &*Diagnostics, Compilation.get());
419   if (!CC1Args)
420     return false;
421   std::unique_ptr<CompilerInvocation> Invocation(
422       newInvocation(&*Diagnostics, *CC1Args, BinaryName));
423   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
424                        std::move(PCHContainerOps));
425 }
426 
427 bool ToolInvocation::runInvocation(
428     const char *BinaryName, driver::Compilation *Compilation,
429     std::shared_ptr<CompilerInvocation> Invocation,
430     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
431   // Show the invocation, with -v.
432   if (Invocation->getHeaderSearchOpts().Verbose) {
433     llvm::errs() << "clang Invocation:\n";
434     Compilation->getJobs().Print(llvm::errs(), "\n", true);
435     llvm::errs() << "\n";
436   }
437 
438   return Action->runInvocation(std::move(Invocation), Files,
439                                std::move(PCHContainerOps), DiagConsumer);
440 }
441 
442 bool FrontendActionFactory::runInvocation(
443     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
444     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
445     DiagnosticConsumer *DiagConsumer) {
446   // Create a compiler instance to handle the actual work.
447   CompilerInstance Compiler(std::move(Invocation), std::move(PCHContainerOps));
448   Compiler.setFileManager(Files);
449 
450   // The FrontendAction can have lifetime requirements for Compiler or its
451   // members, and we need to ensure it's deleted earlier than Compiler. So we
452   // pass it to an std::unique_ptr declared after the Compiler variable.
453   std::unique_ptr<FrontendAction> ScopedToolAction(create());
454 
455   // Create the compiler's actual diagnostics engine.
456   Compiler.createDiagnostics(Files->getVirtualFileSystem(), DiagConsumer,
457                              /*ShouldOwnClient=*/false);
458   if (!Compiler.hasDiagnostics())
459     return false;
460 
461   Compiler.createSourceManager(*Files);
462 
463   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
464 
465   Files->clearStatCache();
466   return Success;
467 }
468 
469 ClangTool::ClangTool(const CompilationDatabase &Compilations,
470                      ArrayRef<std::string> SourcePaths,
471                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
472                      IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS,
473                      IntrusiveRefCntPtr<FileManager> Files)
474     : Compilations(Compilations), SourcePaths(SourcePaths),
475       PCHContainerOps(std::move(PCHContainerOps)),
476       OverlayFileSystem(new llvm::vfs::OverlayFileSystem(std::move(BaseFS))),
477       InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),
478       Files(Files ? Files
479                   : new FileManager(FileSystemOptions(), OverlayFileSystem)) {
480   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
481   appendArgumentsAdjuster(getClangStripOutputAdjuster());
482   appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());
483   appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
484   if (Files)
485     Files->setVirtualFileSystem(OverlayFileSystem);
486 }
487 
488 ClangTool::~ClangTool() = default;
489 
490 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
491   MappedFileContents.push_back(std::make_pair(FilePath, Content));
492 }
493 
494 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
495   ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));
496 }
497 
498 void ClangTool::clearArgumentsAdjusters() {
499   ArgsAdjuster = nullptr;
500 }
501 
502 static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
503                               void *MainAddr) {
504   // Allow users to override the resource dir.
505   for (StringRef Arg : Args)
506     if (Arg.starts_with("-resource-dir"))
507       return;
508 
509   // If there's no override in place add our resource dir.
510   Args = getInsertArgumentAdjuster(
511       ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))
512           .c_str())(Args, "");
513 }
514 
515 int ClangTool::run(ToolAction *Action) {
516   // Exists solely for the purpose of lookup of the resource path.
517   // This just needs to be some symbol in the binary.
518   static int StaticSymbol;
519 
520   // First insert all absolute paths into the in-memory VFS. These are global
521   // for all compile commands.
522   if (SeenWorkingDirectories.insert("/").second)
523     for (const auto &MappedFile : MappedFileContents)
524       if (llvm::sys::path::is_absolute(MappedFile.first))
525         InMemoryFileSystem->addFile(
526             MappedFile.first, 0,
527             llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
528 
529   bool ProcessingFailed = false;
530   bool FileSkipped = false;
531   // Compute all absolute paths before we run any actions, as those will change
532   // the working directory.
533   std::vector<std::string> AbsolutePaths;
534   AbsolutePaths.reserve(SourcePaths.size());
535   for (const auto &SourcePath : SourcePaths) {
536     auto AbsPath = getAbsolutePath(*OverlayFileSystem, SourcePath);
537     if (!AbsPath) {
538       llvm::errs() << "Skipping " << SourcePath
539                    << ". Error while getting an absolute path: "
540                    << llvm::toString(AbsPath.takeError()) << "\n";
541       continue;
542     }
543     AbsolutePaths.push_back(std::move(*AbsPath));
544   }
545 
546   // Remember the working directory in case we need to restore it.
547   std::string InitialWorkingDir;
548   if (auto CWD = OverlayFileSystem->getCurrentWorkingDirectory()) {
549     InitialWorkingDir = std::move(*CWD);
550   } else {
551     llvm::errs() << "Could not get working directory: "
552                  << CWD.getError().message() << "\n";
553   }
554 
555   size_t NumOfTotalFiles = AbsolutePaths.size();
556   unsigned ProcessedFileCounter = 0;
557   for (llvm::StringRef File : AbsolutePaths) {
558     // Currently implementations of CompilationDatabase::getCompileCommands can
559     // change the state of the file system (e.g.  prepare generated headers), so
560     // this method needs to run right before we invoke the tool, as the next
561     // file may require a different (incompatible) state of the file system.
562     //
563     // FIXME: Make the compilation database interface more explicit about the
564     // requirements to the order of invocation of its members.
565     std::vector<CompileCommand> CompileCommandsForFile =
566         Compilations.getCompileCommands(File);
567     if (CompileCommandsForFile.empty()) {
568       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
569       FileSkipped = true;
570       continue;
571     }
572     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
573       // FIXME: chdir is thread hostile; on the other hand, creating the same
574       // behavior as chdir is complex: chdir resolves the path once, thus
575       // guaranteeing that all subsequent relative path operations work
576       // on the same path the original chdir resulted in. This makes a
577       // difference for example on network filesystems, where symlinks might be
578       // switched during runtime of the tool. Fixing this depends on having a
579       // file system abstraction that allows openat() style interactions.
580       if (OverlayFileSystem->setCurrentWorkingDirectory(
581               CompileCommand.Directory))
582         llvm::report_fatal_error("Cannot chdir into \"" +
583                                  Twine(CompileCommand.Directory) + "\"!");
584 
585       // Now fill the in-memory VFS with the relative file mappings so it will
586       // have the correct relative paths. We never remove mappings but that
587       // should be fine.
588       if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)
589         for (const auto &MappedFile : MappedFileContents)
590           if (!llvm::sys::path::is_absolute(MappedFile.first))
591             InMemoryFileSystem->addFile(
592                 MappedFile.first, 0,
593                 llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
594 
595       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
596       if (ArgsAdjuster)
597         CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);
598       assert(!CommandLine.empty());
599 
600       // Add the resource dir based on the binary of this tool. argv[0] in the
601       // compilation database may refer to a different compiler and we want to
602       // pick up the very same standard library that compiler is using. The
603       // builtin headers in the resource dir need to match the exact clang
604       // version the tool is using.
605       // FIXME: On linux, GetMainExecutable is independent of the value of the
606       // first argument, thus allowing ClangTool and runToolOnCode to just
607       // pass in made-up names here. Make sure this works on other platforms.
608       injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);
609 
610       // FIXME: We need a callback mechanism for the tool writer to output a
611       // customized message for each file.
612       if (NumOfTotalFiles > 1)
613         llvm::errs() << "[" + std::to_string(++ProcessedFileCounter) + "/" +
614                             std::to_string(NumOfTotalFiles) +
615                             "] Processing file " + File
616                      << ".\n";
617       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),
618                                 PCHContainerOps);
619       Invocation.setDiagnosticConsumer(DiagConsumer);
620 
621       if (!Invocation.run()) {
622         // FIXME: Diagnostics should be used instead.
623         if (PrintErrorMessage)
624           llvm::errs() << "Error while processing " << File << ".\n";
625         ProcessingFailed = true;
626       }
627     }
628   }
629 
630   if (!InitialWorkingDir.empty()) {
631     if (auto EC =
632             OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))
633       llvm::errs() << "Error when trying to restore working dir: "
634                    << EC.message() << "\n";
635   }
636   return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);
637 }
638 
639 namespace {
640 
641 class ASTBuilderAction : public ToolAction {
642   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
643 
644 public:
645   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
646 
647   bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
648                      FileManager *Files,
649                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
650                      DiagnosticConsumer *DiagConsumer) override {
651     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
652         Invocation, std::move(PCHContainerOps), nullptr,
653         CompilerInstance::createDiagnostics(Files->getVirtualFileSystem(),
654                                             Invocation->getDiagnosticOpts(),
655                                             DiagConsumer,
656                                             /*ShouldOwnClient=*/false),
657         Files);
658     if (!AST)
659       return false;
660 
661     ASTs.push_back(std::move(AST));
662     return true;
663   }
664 };
665 
666 } // namespace
667 
668 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
669   ASTBuilderAction Action(ASTs);
670   return run(&Action);
671 }
672 
673 void ClangTool::setPrintErrorMessage(bool PrintErrorMessage) {
674   this->PrintErrorMessage = PrintErrorMessage;
675 }
676 
677 namespace clang {
678 namespace tooling {
679 
680 std::unique_ptr<ASTUnit>
681 buildASTFromCode(StringRef Code, StringRef FileName,
682                  std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
683   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,
684                                   "clang-tool", std::move(PCHContainerOps));
685 }
686 
687 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
688     StringRef Code, const std::vector<std::string> &Args, StringRef FileName,
689     StringRef ToolName, std::shared_ptr<PCHContainerOperations> PCHContainerOps,
690     ArgumentsAdjuster Adjuster, const FileContentMappings &VirtualMappedFiles,
691     DiagnosticConsumer *DiagConsumer,
692     IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS) {
693   std::vector<std::unique_ptr<ASTUnit>> ASTs;
694   ASTBuilderAction Action(ASTs);
695   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
696       new llvm::vfs::OverlayFileSystem(std::move(BaseFS)));
697   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
698       new llvm::vfs::InMemoryFileSystem);
699   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
700   llvm::IntrusiveRefCntPtr<FileManager> Files(
701       new FileManager(FileSystemOptions(), OverlayFileSystem));
702 
703   ToolInvocation Invocation(
704       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),
705       &Action, Files.get(), std::move(PCHContainerOps));
706   Invocation.setDiagnosticConsumer(DiagConsumer);
707 
708   InMemoryFileSystem->addFile(FileName, 0,
709                               llvm::MemoryBuffer::getMemBufferCopy(Code));
710   for (auto &FilenameWithContent : VirtualMappedFiles) {
711     InMemoryFileSystem->addFile(
712         FilenameWithContent.first, 0,
713         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
714   }
715 
716   if (!Invocation.run())
717     return nullptr;
718 
719   assert(ASTs.size() == 1);
720   return std::move(ASTs[0]);
721 }
722 
723 } // namespace tooling
724 } // namespace clang
725