clang/lib/Tooling/Tooling.cpp

   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   if (RelativePath.startswith("./")) {
 259     RelativePath = RelativePath.substr(strlen("./"));
 260   }
 261
 262   SmallString<1024> AbsolutePath = RelativePath;
 263   if (auto EC = FS.makeAbsolute(AbsolutePath))
 264     return llvm::errorCodeToError(EC);
 265   llvm::sys::path::native(AbsolutePath);
 266   return std::string(AbsolutePath.str());
 267 }
 268
 269 std::string getAbsolutePath(StringRef File) {
 270   return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));
 271 }
 272
 273 void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,
 274                                     StringRef InvokedAs) {
 275   if (CommandLine.empty() || InvokedAs.empty())
 276     return;
 277   const auto &Table = driver::getDriverOptTable();
 278   // --target=X
 279   StringRef TargetOPT =
 280       Table.getOption(driver::options::OPT_target).getPrefixedName();
 281   // -target X
 282   StringRef TargetOPTLegacy =
 283       Table.getOption(driver::options::OPT_target_legacy_spelling)
 284           .getPrefixedName();
 285   // --driver-mode=X
 286   StringRef DriverModeOPT =
 287       Table.getOption(driver::options::OPT_driver_mode).getPrefixedName();
 288   auto TargetMode =
 289       driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);
 290   // No need to search for target args if we don't have a target/mode to insert.
 291   bool ShouldAddTarget = TargetMode.TargetIsValid;
 292   bool ShouldAddMode = TargetMode.DriverMode != nullptr;
 293   // Skip CommandLine[0].
 294   for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();
 295        ++Token) {
 296     StringRef TokenRef(*Token);
 297     ShouldAddTarget = ShouldAddTarget && !TokenRef.startswith(TargetOPT) &&
 298                       !TokenRef.equals(TargetOPTLegacy);
 299     ShouldAddMode = ShouldAddMode && !TokenRef.startswith(DriverModeOPT);
 300   }
 301   if (ShouldAddMode) {
 302     CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);
 303   }
 304   if (ShouldAddTarget) {
 305     CommandLine.insert(++CommandLine.begin(),
 306                        (TargetOPT + TargetMode.TargetPrefix).str());
 307   }
 308 }
 309
 310 void addExpandedResponseFiles(std::vector<std::string> &CommandLine,
 311                               llvm::StringRef WorkingDir,
 312                               llvm::cl::TokenizerCallback Tokenizer,
 313                               llvm::vfs::FileSystem &FS) {
 314   bool SeenRSPFile = false;
 315   llvm::SmallVector<const char *, 20> Argv;
 316   Argv.reserve(CommandLine.size());
 317   for (auto &Arg : CommandLine) {
 318     Argv.push_back(Arg.c_str());
 319     if (!Arg.empty())
 320       SeenRSPFile |= Arg.front() == '@';
 321   }
 322   if (!SeenRSPFile)
 323     return;
 324   llvm::BumpPtrAllocator Alloc;
 325   llvm::cl::ExpansionContext ECtx(Alloc, Tokenizer);
 326   llvm::Error Err =
 327       ECtx.setVFS(&FS).setCurrentDir(WorkingDir).expandResponseFiles(Argv);
 328   if (Err)
 329     llvm::errs() << Err;
 330   // Don't assign directly, Argv aliases CommandLine.
 331   std::vector<std::string> ExpandedArgv(Argv.begin(), Argv.end());
 332   CommandLine = std::move(ExpandedArgv);
 333 }
 334
 335 } // namespace tooling
 336 } // namespace clang
 337
 338 namespace {
 339
 340 class SingleFrontendActionFactory : public FrontendActionFactory {
 341   std::unique_ptr<FrontendAction> Action;
 342
 343 public:
 344   SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)
 345       : Action(std::move(Action)) {}
 346
 347   std::unique_ptr<FrontendAction> create() override {
 348     return std::move(Action);
 349   }
 350 };
 351
 352 } // namespace
 353
 354 ToolInvocation::ToolInvocation(
 355     std::vector<std::string> CommandLine, ToolAction *Action,
 356     FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)
 357     : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),
 358       Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}
 359
 360 ToolInvocation::ToolInvocation(
 361     std::vector<std::string> CommandLine,
 362     std::unique_ptr<FrontendAction> FAction, FileManager *Files,
 363     std::shared_ptr<PCHContainerOperations> PCHContainerOps)
 364     : CommandLine(std::move(CommandLine)),
 365       Action(new SingleFrontendActionFactory(std::move(FAction))),
 366       OwnsAction(true), Files(Files),
 367       PCHContainerOps(std::move(PCHContainerOps)) {}
 368
 369 ToolInvocation::~ToolInvocation() {
 370   if (OwnsAction)
 371     delete Action;
 372 }
 373
 374 bool ToolInvocation::run() {
 375   llvm::opt::ArgStringList Argv;
 376   for (const std::string &Str : CommandLine)
 377     Argv.push_back(Str.c_str());
 378   const char *const BinaryName = Argv[0];
 379
 380   // Parse diagnostic options from the driver command-line only if none were
 381   // explicitly set.
 382   IntrusiveRefCntPtr<DiagnosticOptions> ParsedDiagOpts;
 383   DiagnosticOptions *DiagOpts = this->DiagOpts;
 384   if (!DiagOpts) {
 385     ParsedDiagOpts = CreateAndPopulateDiagOpts(Argv);
 386     DiagOpts = &*ParsedDiagOpts;
 387   }
 388
 389   TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), DiagOpts);
 390   IntrusiveRefCntPtr<DiagnosticsEngine> Diagnostics =
 391       CompilerInstance::createDiagnostics(
 392           &*DiagOpts, DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
 393   // Although `Diagnostics` are used only for command-line parsing, the custom
 394   // `DiagConsumer` might expect a `SourceManager` to be present.
 395   SourceManager SrcMgr(*Diagnostics, *Files);
 396   Diagnostics->setSourceManager(&SrcMgr);
 397
 398   // We already have a cc1, just create an invocation.
 399   if (CommandLine.size() >= 2 && CommandLine[1] == "-cc1") {
 400     ArrayRef<const char *> CC1Args = ArrayRef(Argv).drop_front();
 401     std::unique_ptr<CompilerInvocation> Invocation(
 402         newInvocation(&*Diagnostics, CC1Args, BinaryName));
 403     if (Diagnostics->hasErrorOccurred())
 404       return false;
 405     return Action->runInvocation(std::move(Invocation), Files,
 406                                  std::move(PCHContainerOps), DiagConsumer);
 407   }
 408
 409   const std::unique_ptr<driver::Driver> Driver(
 410       newDriver(&*Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
 411   // The "input file not found" diagnostics from the driver are useful.
 412   // The driver is only aware of the VFS working directory, but some clients
 413   // change this at the FileManager level instead.
 414   // In this case the checks have false positives, so skip them.
 415   if (!Files->getFileSystemOpts().WorkingDir.empty())
 416     Driver->setCheckInputsExist(false);
 417   const std::unique_ptr<driver::Compilation> Compilation(
 418       Driver->BuildCompilation(llvm::ArrayRef(Argv)));
 419   if (!Compilation)
 420     return false;
 421   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
 422       &*Diagnostics, Compilation.get());
 423   if (!CC1Args)
 424     return false;
 425   std::unique_ptr<CompilerInvocation> Invocation(
 426       newInvocation(&*Diagnostics, *CC1Args, BinaryName));
 427   return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),
 428                        std::move(PCHContainerOps));
 429 }
 430
 431 bool ToolInvocation::runInvocation(
 432     const char *BinaryName, driver::Compilation *Compilation,
 433     std::shared_ptr<CompilerInvocation> Invocation,
 434     std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
 435   // Show the invocation, with -v.
 436   if (Invocation->getHeaderSearchOpts().Verbose) {
 437     llvm::errs() << "clang Invocation:\n";
 438     Compilation->getJobs().Print(llvm::errs(), "\n", true);
 439     llvm::errs() << "\n";
 440   }
 441
 442   return Action->runInvocation(std::move(Invocation), Files,
 443                                std::move(PCHContainerOps), DiagConsumer);
 444 }
 445
 446 bool FrontendActionFactory::runInvocation(
 447     std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,
 448     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
 449     DiagnosticConsumer *DiagConsumer) {
 450   // Create a compiler instance to handle the actual work.
 451   CompilerInstance Compiler(std::move(PCHContainerOps));
 452   Compiler.setInvocation(std::move(Invocation));
 453   Compiler.setFileManager(Files);
 454
 455   // The FrontendAction can have lifetime requirements for Compiler or its
 456   // members, and we need to ensure it's deleted earlier than Compiler. So we
 457   // pass it to an std::unique_ptr declared after the Compiler variable.
 458   std::unique_ptr<FrontendAction> ScopedToolAction(create());
 459
 460   // Create the compiler's actual diagnostics engine.
 461   Compiler.createDiagnostics(DiagConsumer, /*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.startswith("-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   for (llvm::StringRef File : AbsolutePaths) {
 560     // Currently implementations of CompilationDatabase::getCompileCommands can
 561     // change the state of the file system (e.g.  prepare generated headers), so
 562     // this method needs to run right before we invoke the tool, as the next
 563     // file may require a different (incompatible) state of the file system.
 564     //
 565     // FIXME: Make the compilation database interface more explicit about the
 566     // requirements to the order of invocation of its members.
 567     std::vector<CompileCommand> CompileCommandsForFile =
 568         Compilations.getCompileCommands(File);
 569     if (CompileCommandsForFile.empty()) {
 570       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
 571       FileSkipped = true;
 572       continue;
 573     }
 574     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
 575       // FIXME: chdir is thread hostile; on the other hand, creating the same
 576       // behavior as chdir is complex: chdir resolves the path once, thus
 577       // guaranteeing that all subsequent relative path operations work
 578       // on the same path the original chdir resulted in. This makes a
 579       // difference for example on network filesystems, where symlinks might be
 580       // switched during runtime of the tool. Fixing this depends on having a
 581       // file system abstraction that allows openat() style interactions.
 582       if (OverlayFileSystem->setCurrentWorkingDirectory(
 583               CompileCommand.Directory))
 584         llvm::report_fatal_error("Cannot chdir into \"" +
 585                                  Twine(CompileCommand.Directory) + "\"!");
 586
 587       // Now fill the in-memory VFS with the relative file mappings so it will
 588       // have the correct relative paths. We never remove mappings but that
 589       // should be fine.
 590       if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)
 591         for (const auto &MappedFile : MappedFileContents)
 592           if (!llvm::sys::path::is_absolute(MappedFile.first))
 593             InMemoryFileSystem->addFile(
 594                 MappedFile.first, 0,
 595                 llvm::MemoryBuffer::getMemBuffer(MappedFile.second));
 596
 597       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
 598       if (ArgsAdjuster)
 599         CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);
 600       assert(!CommandLine.empty());
 601
 602       // Add the resource dir based on the binary of this tool. argv[0] in the
 603       // compilation database may refer to a different compiler and we want to
 604       // pick up the very same standard library that compiler is using. The
 605       // builtin headers in the resource dir need to match the exact clang
 606       // version the tool is using.
 607       // FIXME: On linux, GetMainExecutable is independent of the value of the
 608       // first argument, thus allowing ClangTool and runToolOnCode to just
 609       // pass in made-up names here. Make sure this works on other platforms.
 610       injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);
 611
 612       // FIXME: We need a callback mechanism for the tool writer to output a
 613       // customized message for each file.
 614       LLVM_DEBUG({ llvm::dbgs() << "Processing: " << File << ".\n"; });
 615       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),
 616                                 PCHContainerOps);
 617       Invocation.setDiagnosticConsumer(DiagConsumer);
 618
 619       if (!Invocation.run()) {
 620         // FIXME: Diagnostics should be used instead.
 621         if (PrintErrorMessage)
 622           llvm::errs() << "Error while processing " << File << ".\n";
 623         ProcessingFailed = true;
 624       }
 625     }
 626   }
 627
 628   if (!InitialWorkingDir.empty()) {
 629     if (auto EC =
 630             OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))
 631       llvm::errs() << "Error when trying to restore working dir: "
 632                    << EC.message() << "\n";
 633   }
 634   return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);
 635 }
 636
 637 namespace {
 638
 639 class ASTBuilderAction : public ToolAction {
 640   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
 641
 642 public:
 643   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
 644
 645   bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
 646                      FileManager *Files,
 647                      std::shared_ptr<PCHContainerOperations> PCHContainerOps,
 648                      DiagnosticConsumer *DiagConsumer) override {
 649     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
 650         Invocation, std::move(PCHContainerOps),
 651         CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts(),
 652                                             DiagConsumer,
 653                                             /*ShouldOwnClient=*/false),
 654         Files);
 655     if (!AST)
 656       return false;
 657
 658     ASTs.push_back(std::move(AST));
 659     return true;
 660   }
 661 };
 662
 663 } // namespace
 664
 665 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
 666   ASTBuilderAction Action(ASTs);
 667   return run(&Action);
 668 }
 669
 670 void ClangTool::setPrintErrorMessage(bool PrintErrorMessage) {
 671   this->PrintErrorMessage = PrintErrorMessage;
 672 }
 673
 674 namespace clang {
 675 namespace tooling {
 676
 677 std::unique_ptr<ASTUnit>
 678 buildASTFromCode(StringRef Code, StringRef FileName,
 679                  std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
 680   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,
 681                                   "clang-tool", std::move(PCHContainerOps));
 682 }
 683
 684 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
 685     StringRef Code, const std::vector<std::string> &Args, StringRef FileName,
 686     StringRef ToolName, std::shared_ptr<PCHContainerOperations> PCHContainerOps,
 687     ArgumentsAdjuster Adjuster, const FileContentMappings &VirtualMappedFiles,
 688     DiagnosticConsumer *DiagConsumer) {
 689   std::vector<std::unique_ptr<ASTUnit>> ASTs;
 690   ASTBuilderAction Action(ASTs);
 691   llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
 692       new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
 693   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
 694       new llvm::vfs::InMemoryFileSystem);
 695   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
 696   llvm::IntrusiveRefCntPtr<FileManager> Files(
 697       new FileManager(FileSystemOptions(), OverlayFileSystem));
 698
 699   ToolInvocation Invocation(
 700       getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),
 701       &Action, Files.get(), std::move(PCHContainerOps));
 702   Invocation.setDiagnosticConsumer(DiagConsumer);
 703
 704   InMemoryFileSystem->addFile(FileName, 0,
 705                               llvm::MemoryBuffer::getMemBufferCopy(Code));
 706   for (auto &FilenameWithContent : VirtualMappedFiles) {
 707     InMemoryFileSystem->addFile(
 708         FilenameWithContent.first, 0,
 709         llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));
 710   }
 711
 712   if (!Invocation.run())
 713     return nullptr;
 714
 715   assert(ASTs.size() == 1);
 716   return std::move(ASTs[0]);
 717 }
 718
 719 } // namespace tooling
 720 } // namespace clang