xref: /llvm-project/clang/lib/Tooling/Tooling.cpp (revision 6ca560a9092e29c9f9817db6d6da09edd5f0ded7)
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/CommandLine.h"
47 #include "llvm/Support/Debug.h"
48 #include "llvm/Support/ErrorHandling.h"
49 #include "llvm/Support/FileSystem.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 "llvm/TargetParser/Host.h"
55 #include <cassert>
56 #include <cstring>
57 #include <memory>
58 #include <string>
59 #include <system_error>
60 #include <utility>
61 #include <vector>
62 
63 #define DEBUG_TYPE "clang-tooling"
64 
65 using namespace clang;
66 using namespace tooling;
67 
68 ToolAction::~ToolAction() = default;
69 
70 FrontendActionFactory::~FrontendActionFactory() = default;
71 
72 // FIXME: This file contains structural duplication with other parts of the
73 // code that sets up a compiler to run tools on it, and we should refactor
74 // it to be based on the same framework.
75 
76 /// Builds a clang driver initialized for running clang tools.
77 static driver::Driver *
78 newDriver(DiagnosticsEngine *Diagnostics, const char *BinaryName,
79           IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
80   driver::Driver *CompilerDriver =
81       new driver::Driver(BinaryName, llvm::sys::getDefaultTargetTriple(),
82                          *Diagnostics, "clang LLVM compiler", std::move(VFS));
83   CompilerDriver->setTitle("clang_based_tool");
84   return CompilerDriver;
85 }
86 
87 /// Decide whether extra compiler frontend commands can be ignored.
88 static bool ignoreExtraCC1Commands(const driver::Compilation *Compilation) {
89   const driver::JobList &Jobs = Compilation->getJobs();
90   const driver::ActionList &Actions = Compilation->getActions();
91 
92   bool OffloadCompilation = false;
93 
94   // Jobs and Actions look very different depending on whether the Clang tool
95   // injected -fsyntax-only or not. Try to handle both cases here.
96 
97   for (const auto &Job : Jobs)
98     if (StringRef(Job.getExecutable()) == "clang-offload-bundler")
99       OffloadCompilation = true;
100 
101   if (Jobs.size() > 1) {
102     for (auto *A : Actions){
103       // On MacOSX real actions may end up being wrapped in BindArchAction
104       if (isa<driver::BindArchAction>(A))
105         A = *A->input_begin();
106       if (isa<driver::OffloadAction>(A)) {
107         // Offload compilation has 2 top-level actions, one (at the front) is
108         // the original host compilation and the other is offload action
109         // composed of at least one device compilation. For such case, general
110         // tooling will consider host-compilation only. For tooling on device
111         // compilation, device compilation only option, such as
112         // `--cuda-device-only`, needs specifying.
113         assert(Actions.size() > 1);
114         assert(
115             isa<driver::CompileJobAction>(Actions.front()) ||
116             // On MacOSX real actions may end up being wrapped in
117             // BindArchAction.
118             (isa<driver::BindArchAction>(Actions.front()) &&
119              isa<driver::CompileJobAction>(*Actions.front()->input_begin())));
120         OffloadCompilation = true;
121         break;
122       }
123     }
124   }
125 
126   return OffloadCompilation;
127 }
128 
129 namespace clang {
130 namespace tooling {
131 
132 const llvm::opt::ArgStringList *
133 getCC1Arguments(DiagnosticsEngine *Diagnostics,
134                 driver::Compilation *Compilation) {
135   const driver::JobList &Jobs = Compilation->getJobs();
136 
137   auto IsCC1Command = [](const driver::Command &Cmd) {
138     return StringRef(Cmd.getCreator().getName()) == "clang";
139   };
140 
141   auto IsSrcFile = [](const driver::InputInfo &II) {
142     return isSrcFile(II.getType());
143   };
144 
145   llvm::SmallVector<const driver::Command *, 1> CC1Jobs;
146   for (const driver::Command &Job : Jobs)
147     if (IsCC1Command(Job) && llvm::all_of(Job.getInputInfos(), IsSrcFile))
148       CC1Jobs.push_back(&Job);
149 
150   // If there are no jobs for source files, try checking again for a single job
151   // with any file type. This accepts a preprocessed file as input.
152   if (CC1Jobs.empty())
153     for (const driver::Command &Job : Jobs)
154       if (IsCC1Command(Job))
155         CC1Jobs.push_back(&Job);
156 
157   if (CC1Jobs.empty() ||
158       (CC1Jobs.size() > 1 && !ignoreExtraCC1Commands(Compilation))) {
159     SmallString<256> error_msg;
160     llvm::raw_svector_ostream error_stream(error_msg);
161     Jobs.Print(error_stream, "; ", true);
162     Diagnostics->Report(diag::err_fe_expected_compiler_job)
163         << error_stream.str();
164     return nullptr;
165   }
166 
167   return &CC1Jobs[0]->getArguments();
168 }
169 
170 /// Returns a clang build invocation initialized from the CC1 flags.
171 CompilerInvocation *newInvocation(DiagnosticsEngine *Diagnostics,
172                                   ArrayRef<const char *> CC1Args,
173                                   const char *const BinaryName) {
174   assert(!CC1Args.empty() && "Must at least contain the program name!");
175   CompilerInvocation *Invocation = new CompilerInvocation;
176   CompilerInvocation::CreateFromArgs(*Invocation, CC1Args, *Diagnostics,
177                                      BinaryName);
178   Invocation->getFrontendOpts().DisableFree = false;
179   Invocation->getCodeGenOpts().DisableFree = false;
180   return Invocation;
181 }
182 
183 bool runToolOnCode(std::unique_ptr<FrontendAction> ToolAction,
184                    const Twine &Code, const Twine &FileName,
185                    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
186   return runToolOnCodeWithArgs(std::move(ToolAction), Code,
187                                std::vector<std::string>(), FileName,
188                                "clang-tool", std::move(PCHContainerOps));
189 }
190 
191 } // namespace tooling
192 } // namespace clang
193 
194 static std::vector<std::string>
195 getSyntaxOnlyToolArgs(const Twine &ToolName,
196                       const std::vector<std::string> &ExtraArgs,
197                       StringRef FileName) {
198   std::vector<std::string> Args;
199   Args.push_back(ToolName.str());
200   Args.push_back("-fsyntax-only");
201   Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());
202   Args.push_back(FileName.str());
203   return Args;
204 }
205 
206 namespace clang {
207 namespace tooling {
208 
209 bool runToolOnCodeWithArgs(
210     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
211     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
212     const std::vector<std::string> &Args, const Twine &FileName,
213     const Twine &ToolName,
214     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
215   SmallString<16> FileNameStorage;
216   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
217 
218   llvm::IntrusiveRefCntPtr<FileManager> Files(
219       new FileManager(FileSystemOptions(), VFS));
220   ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();
221   ToolInvocation Invocation(
222       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
223       std::move(ToolAction), Files.get(), std::move(PCHContainerOps));
224   return Invocation.run();
225 }
226 
227 bool runToolOnCodeWithArgs(
228     std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,
229     const std::vector<std::string> &Args, const Twine &FileName,
230     const Twine &ToolName,
231     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
232     const FileContentMappings &VirtualMappedFiles) {
233   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
234       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
235   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
236       new llvm::vfs::InMemoryFileSystem);
237   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
238 
239   SmallString<1024> CodeStorage;
240   InMemoryFileSystem->addFile(FileName, 0,
241                               llvm::MemoryBuffer::getMemBuffer(
242                                   Code.toNullTerminatedStringRef(CodeStorage)));
243 
244   for (auto &FilenameWithContent : VirtualMappedFiles) {
245     InMemoryFileSystem->addFile(
246         FilenameWithContent.first, 0,
247         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
248   }
249 
250   return runToolOnCodeWithArgs(std::move(ToolAction), Code, OverlayFileSystem,
251                                Args, FileName, ToolName);
252 }
253 
254 llvm::Expected<std::string> getAbsolutePath(llvm::vfs::FileSystem &FS,
255                                             StringRef File) {
256   StringRef RelativePath(File);
257   // FIXME: Should '.\\' be accepted on Win32?
258   RelativePath.consume_front("./");
259 
260   SmallString<1024> AbsolutePath = RelativePath;
261   if (auto EC = FS.makeAbsolute(AbsolutePath))
262     return llvm::errorCodeToError(EC);
263   llvm::sys::path::native(AbsolutePath);
264   return std::string(AbsolutePath);
265 }
266 
267 std::string getAbsolutePath(StringRef File) {
268   return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));
269 }
270 
271 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
272                                     StringRef InvokedAs) {
273   if (CommandLine.empty() || InvokedAs.empty())
274     return;
275   const auto &Table = driver::getDriverOptTable();
276   // --target=X
277   StringRef TargetOPT =
278       Table.getOption(driver::options::OPT_target).getPrefixedName();
279   // -target X
280   StringRef TargetOPTLegacy =
281       Table.getOption(driver::options::OPT_target_legacy_spelling)
282           .getPrefixedName();
283   // --driver-mode=X
284   StringRef DriverModeOPT =
285       Table.getOption(driver::options::OPT_driver_mode).getPrefixedName();
286   auto TargetMode =
287       driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
288   // No need to search for target args if we don't have a target/mode to insert.
289   bool ShouldAddTarget = TargetMode.TargetIsValid;
290   bool ShouldAddMode = TargetMode.DriverMode != nullptr;
291   // Skip CommandLine[0].
292   for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
293        ++Token) {
294     StringRef TokenRef(*Token);
295     ShouldAddTarget = ShouldAddTarget && !TokenRef.starts_with(TargetOPT) &&
296                       TokenRef != TargetOPTLegacy;
297     ShouldAddMode = ShouldAddMode && !TokenRef.starts_with(DriverModeOPT);
298   }
299   if (ShouldAddMode) {
300     CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
301   }
302   if (ShouldAddTarget) {
303     CommandLine.insert(++CommandLine.begin(),
304                        (TargetOPT + TargetMode.TargetPrefix).str());
305   }
306 }
307 
308 void addExpandedResponseFiles(std::vector<std::string> &CommandLine,
309                               llvm::StringRef WorkingDir,
310                               llvm::cl::TokenizerCallback Tokenizer,
311                               llvm::vfs::FileSystem &FS) {
312   bool SeenRSPFile = false;
313   llvm::SmallVector<const char *, 20> Argv;
314   Argv.reserve(CommandLine.size());
315   for (auto &Arg : CommandLine) {
316     Argv.push_back(Arg.c_str());
317     if (!Arg.empty())
318       SeenRSPFile |= Arg.front() == '@';
319   }
320   if (!SeenRSPFile)
321     return;
322   llvm::BumpPtrAllocator Alloc;
323   llvm::cl::ExpansionContext ECtx(Alloc, Tokenizer);
324   llvm::Error Err =
325       ECtx.setVFS(&FS).setCurrentDir(WorkingDir).expandResponseFiles(Argv);
326   if (Err)
327     llvm::errs() << Err;
328   // Don't assign directly, Argv aliases CommandLine.
329   std::vector<std::string> ExpandedArgv(Argv.begin(), Argv.end());
330   CommandLine = std::move(ExpandedArgv);
331 }
332 
333 } // namespace tooling
334 } // namespace clang
335 
336 namespace {
337 
338 class SingleFrontendActionFactory : public FrontendActionFactory {
339   std::unique_ptr<FrontendAction> Action;
340 
341 public:
342   SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)
343       : Action(std::move(Action)) {}
344 
345   std::unique_ptr<FrontendAction> create() override {
346     return std::move(Action);
347   }
348 };
349 
350 } // namespace
351 
352 ToolInvocation::ToolInvocation(
353     std::vector<std::string> CommandLine, ToolAction *Action,
354     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
355     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
356       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
357 
358 ToolInvocation::ToolInvocation(
359     std::vector<std::string> CommandLine,
360     std::unique_ptr<FrontendAction> FAction, FileManager *Files,
361     std::shared_ptr<PCHContainerOperations> PCHContainerOps)
362     : CommandLine(std::move(CommandLine)),
363       Action(new SingleFrontendActionFactory(std::move(FAction))),
364       OwnsAction(true), Files(Files),
365       PCHContainerOps(std::move(PCHContainerOps)) {}
366 
367 ToolInvocation::~ToolInvocation() {
368   if (OwnsAction)
369     delete Action;
370 }
371 
372 bool ToolInvocation::run() {
373   llvm::opt::ArgStringList Argv;
374   for (const std::string &Str : CommandLine)
375     Argv.push_back(Str.c_str());
376   const char *const BinaryName = Argv[0];
377 
378   // Parse diagnostic options from the driver command-line only if none were
379   // explicitly set.
380   IntrusiveRefCntPtr<DiagnosticOptions> ParsedDiagOpts;
381   DiagnosticOptions *DiagOpts = this->DiagOpts;
382   if (!DiagOpts) {
383     ParsedDiagOpts = CreateAndPopulateDiagOpts(Argv);
384     DiagOpts = &*ParsedDiagOpts;
385   }
386 
387   TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), DiagOpts);
388   IntrusiveRefCntPtr<DiagnosticsEngine> Diagnostics =
389       CompilerInstance::createDiagnostics(
390           Files->getVirtualFileSystem(), &*DiagOpts,
391           DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
392   // Although `Diagnostics` are used only for command-line parsing, the custom
393   // `DiagConsumer` might expect a `SourceManager` to be present.
394   SourceManager SrcMgr(*Diagnostics, *Files);
395   Diagnostics->setSourceManager(&SrcMgr);
396 
397   // We already have a cc1, just create an invocation.
398   if (CommandLine.size() >= 2 && CommandLine[1] == "-cc1") {
399     ArrayRef<const char *> CC1Args = ArrayRef(Argv).drop_front();
400     std::unique_ptr<CompilerInvocation> Invocation(
401         newInvocation(&*Diagnostics, CC1Args, BinaryName));
402     if (Diagnostics->hasErrorOccurred())
403       return false;
404     return Action->runInvocation(std::move(Invocation), Files,
405                                  std::move(PCHContainerOps), DiagConsumer);
406   }
407 
408   const std::unique_ptr<driver::Driver> Driver(
409       newDriver(&*Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
410   // The "input file not found" diagnostics from the driver are useful.
411   // The driver is only aware of the VFS working directory, but some clients
412   // change this at the FileManager level instead.
413   // In this case the checks have false positives, so skip them.
414   if (!Files->getFileSystemOpts().WorkingDir.empty())
415     Driver->setCheckInputsExist(false);
416   const std::unique_ptr<driver::Compilation> Compilation(
417       Driver->BuildCompilation(llvm::ArrayRef(Argv)));
418   if (!Compilation)
419     return false;
420   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
421       &*Diagnostics, Compilation.get());
422   if (!CC1Args)
423     return false;
424   std::unique_ptr<CompilerInvocation> Invocation(
425       newInvocation(&*Diagnostics, *CC1Args, BinaryName));
426   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
427                        std::move(PCHContainerOps));
428 }
429 
430 bool ToolInvocation::runInvocation(
431     const char *BinaryName, driver::Compilation *Compilation,
432     std::shared_ptr<CompilerInvocation> Invocation,
433     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
434   // Show the invocation, with -v.
435   if (Invocation->getHeaderSearchOpts().Verbose) {
436     llvm::errs() << "clang Invocation:\n";
437     Compilation->getJobs().Print(llvm::errs(), "\n", true);
438     llvm::errs() << "\n";
439   }
440 
441   return Action->runInvocation(std::move(Invocation), Files,
442                                std::move(PCHContainerOps), DiagConsumer);
443 }
444 
445 bool FrontendActionFactory::runInvocation(
446     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
447     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
448     DiagnosticConsumer *DiagConsumer) {
449   // Create a compiler instance to handle the actual work.
450   CompilerInstance Compiler(std::move(PCHContainerOps));
451   Compiler.setInvocation(std::move(Invocation));
452   Compiler.setFileManager(Files);
453 
454   // The FrontendAction can have lifetime requirements for Compiler or its
455   // members, and we need to ensure it's deleted earlier than Compiler. So we
456   // pass it to an std::unique_ptr declared after the Compiler variable.
457   std::unique_ptr<FrontendAction> ScopedToolAction(create());
458 
459   // Create the compiler's actual diagnostics engine.
460   Compiler.createDiagnostics(Files->getVirtualFileSystem(), DiagConsumer,
461                              /*ShouldOwnClient=*/false);
462   if (!Compiler.hasDiagnostics())
463     return false;
464 
465   Compiler.createSourceManager(*Files);
466 
467   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
468 
469   Files->clearStatCache();
470   return Success;
471 }
472 
473 ClangTool::ClangTool(const CompilationDatabase &Compilations,
474                      ArrayRef<std::string> SourcePaths,
475                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
476                      IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS,
477                      IntrusiveRefCntPtr<FileManager> Files)
478     : Compilations(Compilations), SourcePaths(SourcePaths),
479       PCHContainerOps(std::move(PCHContainerOps)),
480       OverlayFileSystem(new llvm::vfs::OverlayFileSystem(std::move(BaseFS))),
481       InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),
482       Files(Files ? Files
483                   : new FileManager(FileSystemOptions(), OverlayFileSystem)) {
484   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
485   appendArgumentsAdjuster(getClangStripOutputAdjuster());
486   appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());
487   appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
488   if (Files)
489     Files->setVirtualFileSystem(OverlayFileSystem);
490 }
491 
492 ClangTool::~ClangTool() = default;
493 
494 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
495   MappedFileContents.push_back(std::make_pair(FilePath, Content));
496 }
497 
498 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
499   ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));
500 }
501 
502 void ClangTool::clearArgumentsAdjusters() {
503   ArgsAdjuster = nullptr;
504 }
505 
506 static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
507                               void *MainAddr) {
508   // Allow users to override the resource dir.
509   for (StringRef Arg : Args)
510     if (Arg.starts_with("-resource-dir"))
511       return;
512 
513   // If there's no override in place add our resource dir.
514   Args = getInsertArgumentAdjuster(
515       ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))
516           .c_str())(Args, "");
517 }
518 
519 int ClangTool::run(ToolAction *Action) {
520   // Exists solely for the purpose of lookup of the resource path.
521   // This just needs to be some symbol in the binary.
522   static int StaticSymbol;
523 
524   // First insert all absolute paths into the in-memory VFS. These are global
525   // for all compile commands.
526   if (SeenWorkingDirectories.insert("/").second)
527     for (const auto &MappedFile : MappedFileContents)
528       if (llvm::sys::path::is_absolute(MappedFile.first))
529         InMemoryFileSystem->addFile(
530             MappedFile.first, 0,
531             llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
532 
533   bool ProcessingFailed = false;
534   bool FileSkipped = false;
535   // Compute all absolute paths before we run any actions, as those will change
536   // the working directory.
537   std::vector<std::string> AbsolutePaths;
538   AbsolutePaths.reserve(SourcePaths.size());
539   for (const auto &SourcePath : SourcePaths) {
540     auto AbsPath = getAbsolutePath(*OverlayFileSystem, SourcePath);
541     if (!AbsPath) {
542       llvm::errs() << "Skipping " << SourcePath
543                    << ". Error while getting an absolute path: "
544                    << llvm::toString(AbsPath.takeError()) << "\n";
545       continue;
546     }
547     AbsolutePaths.push_back(std::move(*AbsPath));
548   }
549 
550   // Remember the working directory in case we need to restore it.
551   std::string InitialWorkingDir;
552   if (auto CWD = OverlayFileSystem->getCurrentWorkingDirectory()) {
553     InitialWorkingDir = std::move(*CWD);
554   } else {
555     llvm::errs() << "Could not get working directory: "
556                  << CWD.getError().message() << "\n";
557   }
558 
559   size_t NumOfTotalFiles = AbsolutePaths.size();
560   unsigned ProcessedFileCounter = 0;
561   for (llvm::StringRef File : AbsolutePaths) {
562     // Currently implementations of CompilationDatabase::getCompileCommands can
563     // change the state of the file system (e.g.  prepare generated headers), so
564     // this method needs to run right before we invoke the tool, as the next
565     // file may require a different (incompatible) state of the file system.
566     //
567     // FIXME: Make the compilation database interface more explicit about the
568     // requirements to the order of invocation of its members.
569     std::vector<CompileCommand> CompileCommandsForFile =
570         Compilations.getCompileCommands(File);
571     if (CompileCommandsForFile.empty()) {
572       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
573       FileSkipped = true;
574       continue;
575     }
576     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
577       // FIXME: chdir is thread hostile; on the other hand, creating the same
578       // behavior as chdir is complex: chdir resolves the path once, thus
579       // guaranteeing that all subsequent relative path operations work
580       // on the same path the original chdir resulted in. This makes a
581       // difference for example on network filesystems, where symlinks might be
582       // switched during runtime of the tool. Fixing this depends on having a
583       // file system abstraction that allows openat() style interactions.
584       if (OverlayFileSystem->setCurrentWorkingDirectory(
585               CompileCommand.Directory))
586         llvm::report_fatal_error("Cannot chdir into \"" +
587                                  Twine(CompileCommand.Directory) + "\"!");
588 
589       // Now fill the in-memory VFS with the relative file mappings so it will
590       // have the correct relative paths. We never remove mappings but that
591       // should be fine.
592       if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)
593         for (const auto &MappedFile : MappedFileContents)
594           if (!llvm::sys::path::is_absolute(MappedFile.first))
595             InMemoryFileSystem->addFile(
596                 MappedFile.first, 0,
597                 llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
598 
599       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
600       if (ArgsAdjuster)
601         CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);
602       assert(!CommandLine.empty());
603 
604       // Add the resource dir based on the binary of this tool. argv[0] in the
605       // compilation database may refer to a different compiler and we want to
606       // pick up the very same standard library that compiler is using. The
607       // builtin headers in the resource dir need to match the exact clang
608       // version the tool is using.
609       // FIXME: On linux, GetMainExecutable is independent of the value of the
610       // first argument, thus allowing ClangTool and runToolOnCode to just
611       // pass in made-up names here. Make sure this works on other platforms.
612       injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);
613 
614       // FIXME: We need a callback mechanism for the tool writer to output a
615       // customized message for each file.
616       if (NumOfTotalFiles > 1)
617         llvm::errs() << "[" + std::to_string(++ProcessedFileCounter) + "/" +
618                             std::to_string(NumOfTotalFiles) +
619                             "] Processing file " + File
620                      << ".\n";
621       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),
622                                 PCHContainerOps);
623       Invocation.setDiagnosticConsumer(DiagConsumer);
624 
625       if (!Invocation.run()) {
626         // FIXME: Diagnostics should be used instead.
627         if (PrintErrorMessage)
628           llvm::errs() << "Error while processing " << File << ".\n";
629         ProcessingFailed = true;
630       }
631     }
632   }
633 
634   if (!InitialWorkingDir.empty()) {
635     if (auto EC =
636             OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))
637       llvm::errs() << "Error when trying to restore working dir: "
638                    << EC.message() << "\n";
639   }
640   return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);
641 }
642 
643 namespace {
644 
645 class ASTBuilderAction : public ToolAction {
646   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
647 
648 public:
649   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
650 
651   bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
652                      FileManager *Files,
653                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
654                      DiagnosticConsumer *DiagConsumer) override {
655     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
656         Invocation, std::move(PCHContainerOps),
657         CompilerInstance::createDiagnostics(Files->getVirtualFileSystem(),
658                                             &Invocation->getDiagnosticOpts(),
659                                             DiagConsumer,
660                                             /*ShouldOwnClient=*/false),
661         Files);
662     if (!AST)
663       return false;
664 
665     ASTs.push_back(std::move(AST));
666     return true;
667   }
668 };
669 
670 } // namespace
671 
672 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
673   ASTBuilderAction Action(ASTs);
674   return run(&Action);
675 }
676 
677 void ClangTool::setPrintErrorMessage(bool PrintErrorMessage) {
678   this->PrintErrorMessage = PrintErrorMessage;
679 }
680 
681 namespace clang {
682 namespace tooling {
683 
684 std::unique_ptr<ASTUnit>
685 buildASTFromCode(StringRef Code, StringRef FileName,
686                  std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
687   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,
688                                   "clang-tool", std::move(PCHContainerOps));
689 }
690 
691 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
692     StringRef Code, const std::vector<std::string> &Args, StringRef FileName,
693     StringRef ToolName, std::shared_ptr<PCHContainerOperations> PCHContainerOps,
694     ArgumentsAdjuster Adjuster, const FileContentMappings &VirtualMappedFiles,
695     DiagnosticConsumer *DiagConsumer,
696     IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS) {
697   std::vector<std::unique_ptr<ASTUnit>> ASTs;
698   ASTBuilderAction Action(ASTs);
699   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
700       new llvm::vfs::OverlayFileSystem(std::move(BaseFS)));
701   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
702       new llvm::vfs::InMemoryFileSystem);
703   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
704   llvm::IntrusiveRefCntPtr<FileManager> Files(
705       new FileManager(FileSystemOptions(), OverlayFileSystem));
706 
707   ToolInvocation Invocation(
708       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),
709       &Action, Files.get(), std::move(PCHContainerOps));
710   Invocation.setDiagnosticConsumer(DiagConsumer);
711 
712   InMemoryFileSystem->addFile(FileName, 0,
713                               llvm::MemoryBuffer::getMemBufferCopy(Code));
714   for (auto &FilenameWithContent : VirtualMappedFiles) {
715     InMemoryFileSystem->addFile(
716         FilenameWithContent.first, 0,
717         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
718   }
719 
720   if (!Invocation.run())
721     return nullptr;
722 
723   assert(ASTs.size() == 1);
724   return std::move(ASTs[0]);
725 }
726 
727 } // namespace tooling
728 } // namespace clang
729