//===- Tooling.cpp - Running clang standalone tools -----------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

//  This file implements functions to run clang tools standalone instead

//  of running them as a plugin.

//

//===----------------------------------------------------------------------===//

#include "clang/Tooling/Tooling.h"

#include "clang/Basic/Diagnostic.h"

#include "clang/Basic/DiagnosticIDs.h"

#include "clang/Basic/DiagnosticOptions.h"

#include "clang/Basic/FileManager.h"

#include "clang/Basic/FileSystemOptions.h"

#include "clang/Basic/LLVM.h"

#include "clang/Driver/Compilation.h"

#include "clang/Driver/Driver.h"

#include "clang/Driver/Job.h"

#include "clang/Driver/Options.h"

#include "clang/Driver/Tool.h"

#include "clang/Driver/ToolChain.h"

#include "clang/Frontend/ASTUnit.h"

#include "clang/Frontend/CompilerInstance.h"

#include "clang/Frontend/CompilerInvocation.h"

#include "clang/Frontend/FrontendDiagnostic.h"

#include "clang/Frontend/FrontendOptions.h"

#include "clang/Frontend/TextDiagnosticPrinter.h"

#include "clang/Lex/HeaderSearchOptions.h"

#include "clang/Lex/PreprocessorOptions.h"

#include "clang/Tooling/ArgumentsAdjusters.h"

#include "clang/Tooling/CompilationDatabase.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/IntrusiveRefCntPtr.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/ADT/Twine.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Option/OptTable.h"

#include "llvm/Option/Option.h"

#include "llvm/Support/Casting.h"

#include "llvm/Support/CommandLine.h"

#include "llvm/Support/Debug.h"

#include "llvm/Support/ErrorHandling.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/MemoryBuffer.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/VirtualFileSystem.h"

#include "llvm/Support/raw_ostream.h"

#include "llvm/TargetParser/Host.h"

#include <cassert>

#include <cstring>

#include <memory>

#include <string>

#include <system_error>

#include <utility>

#include <vector>

#define DEBUG_TYPE "clang-tooling"

using namespace clang;

using namespace tooling;

ToolAction::~ToolAction() = default;

FrontendActionFactory::~FrontendActionFactory() = default;

// FIXME: This file contains structural duplication with other parts of the

// code that sets up a compiler to run tools on it, and we should refactor

// it to be based on the same framework.

/// Builds a clang driver initialized for running clang tools.

static driver::Driver *

newDriver(DiagnosticsEngine *Diagnostics, const char *BinaryName,

          IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {

  driver::Driver *CompilerDriver =

      new driver::Driver(BinaryName, llvm::sys::getDefaultTargetTriple(),

                         *Diagnostics, "clang LLVM compiler", std::move(VFS));

  CompilerDriver->setTitle("clang_based_tool");

  return CompilerDriver;

}

/// Decide whether extra compiler frontend commands can be ignored.

static bool ignoreExtraCC1Commands(const driver::Compilation *Compilation) {

  const driver::JobList &Jobs = Compilation->getJobs();

  const driver::ActionList &Actions = Compilation->getActions();

  bool OffloadCompilation = false;

  // Jobs and Actions look very different depending on whether the Clang tool

  // injected -fsyntax-only or not. Try to handle both cases here.

  for (const auto &Job : Jobs)

    if (StringRef(Job.getExecutable()) == "clang-offload-bundler")

      OffloadCompilation = true;

  if (Jobs.size() > 1) {

    for (auto *A : Actions){

      // On MacOSX real actions may end up being wrapped in BindArchAction

      if (isa<driver::BindArchAction>(A))

        A = *A->input_begin();

      if (isa<driver::OffloadAction>(A)) {

        // Offload compilation has 2 top-level actions, one (at the front) is

        // the original host compilation and the other is offload action

        // composed of at least one device compilation. For such case, general

        // tooling will consider host-compilation only. For tooling on device

        // compilation, device compilation only option, such as

        // `--cuda-device-only`, needs specifying.

        assert(Actions.size() > 1);

        assert(

            isa<driver::CompileJobAction>(Actions.front()) ||

            // On MacOSX real actions may end up being wrapped in

            // BindArchAction.

            (isa<driver::BindArchAction>(Actions.front()) &&

             isa<driver::CompileJobAction>(*Actions.front()->input_begin())));

        OffloadCompilation = true;

        break;

      }

    }

  }

  return OffloadCompilation;

}

namespace clang {

namespace tooling {

const llvm::opt::ArgStringList *

getCC1Arguments(DiagnosticsEngine *Diagnostics,

                driver::Compilation *Compilation) {

  const driver::JobList &Jobs = Compilation->getJobs();

  auto IsCC1Command = [](const driver::Command &Cmd) {

    return StringRef(Cmd.getCreator().getName()) == "clang";

  };

  auto IsSrcFile = [](const driver::InputInfo &II) {

    return isSrcFile(II.getType());

  };

  llvm::SmallVector<const driver::Command *, 1> CC1Jobs;

  for (const driver::Command &Job : Jobs)

    if (IsCC1Command(Job) && llvm::all_of(Job.getInputInfos(), IsSrcFile))

      CC1Jobs.push_back(&Job);

  // If there are no jobs for source files, try checking again for a single job

  // with any file type. This accepts a preprocessed file as input.

  if (CC1Jobs.empty())

    for (const driver::Command &Job : Jobs)

      if (IsCC1Command(Job))

        CC1Jobs.push_back(&Job);

  if (CC1Jobs.empty() ||

      (CC1Jobs.size() > 1 && !ignoreExtraCC1Commands(Compilation))) {

    SmallString<256> error_msg;

    llvm::raw_svector_ostream error_stream(error_msg);

    Jobs.Print(error_stream, "; ", true);

    Diagnostics->Report(diag::err_fe_expected_compiler_job)

        << error_stream.str();

    return nullptr;

  }

  return &CC1Jobs[0]->getArguments();

}

/// Returns a clang build invocation initialized from the CC1 flags.

CompilerInvocation *newInvocation(DiagnosticsEngine *Diagnostics,

                                  ArrayRef<const char *> CC1Args,

                                  const char *const BinaryName) {

  assert(!CC1Args.empty() && "Must at least contain the program name!");

  CompilerInvocation *Invocation = new CompilerInvocation;

  CompilerInvocation::CreateFromArgs(*Invocation, CC1Args, *Diagnostics,

                                     BinaryName);

  Invocation->getFrontendOpts().DisableFree = false;

  Invocation->getCodeGenOpts().DisableFree = false;

  return Invocation;

}

bool runToolOnCode(std::unique_ptr<FrontendAction> ToolAction,

                   const Twine &Code, const Twine &FileName,

                   std::shared_ptr<PCHContainerOperations> PCHContainerOps) {

  return runToolOnCodeWithArgs(std::move(ToolAction), Code,

                               std::vector<std::string>(), FileName,

                               "clang-tool", std::move(PCHContainerOps));

}

} // namespace tooling

} // namespace clang

static std::vector<std::string>

getSyntaxOnlyToolArgs(const Twine &ToolName,

                      const std::vector<std::string> &ExtraArgs,

                      StringRef FileName) {

  std::vector<std::string> Args;

  Args.push_back(ToolName.str());

  Args.push_back("-fsyntax-only");

  Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());

  Args.push_back(FileName.str());

  return Args;

}

namespace clang {

namespace tooling {

bool runToolOnCodeWithArgs(

    std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,

    llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,

    const std::vector<std::string> &Args, const Twine &FileName,

    const Twine &ToolName,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {

  SmallString<16> FileNameStorage;

  StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);

  llvm::IntrusiveRefCntPtr<FileManager> Files(

      new FileManager(FileSystemOptions(), VFS));

  ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster();

  ToolInvocation Invocation(

      getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),

      std::move(ToolAction), Files.get(), std::move(PCHContainerOps));

  return Invocation.run();

}

bool runToolOnCodeWithArgs(

    std::unique_ptr<FrontendAction> ToolAction, const Twine &Code,

    const std::vector<std::string> &Args, const Twine &FileName,

    const Twine &ToolName,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    const FileContentMappings &VirtualMappedFiles) {

  llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(

      new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));

  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(

      new llvm::vfs::InMemoryFileSystem);

  OverlayFileSystem->pushOverlay(InMemoryFileSystem);

  SmallString<1024> CodeStorage;

  InMemoryFileSystem->addFile(FileName, 0,

                              llvm::MemoryBuffer::getMemBuffer(

                                  Code.toNullTerminatedStringRef(CodeStorage)));

  for (auto &FilenameWithContent : VirtualMappedFiles) {

    InMemoryFileSystem->addFile(

        FilenameWithContent.first, 0,

        llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));

  }

  return runToolOnCodeWithArgs(std::move(ToolAction), Code, OverlayFileSystem,

                               Args, FileName, ToolName);

}

llvm::Expected<std::string> getAbsolutePath(llvm::vfs::FileSystem &FS,

                                            StringRef File) {

  StringRef RelativePath(File);

  // FIXME: Should '.\\' be accepted on Win32?

  RelativePath.consume_front("./");

  SmallString<1024> AbsolutePath = RelativePath;

  if (auto EC = FS.makeAbsolute(AbsolutePath))

    return llvm::errorCodeToError(EC);

  llvm::sys::path::native(AbsolutePath);

  return std::string(AbsolutePath.str());

}

std::string getAbsolutePath(StringRef File) {

  return llvm::cantFail(getAbsolutePath(*llvm::vfs::getRealFileSystem(), File));

}

void addTargetAndModeForProgramName(std::vector<std::string> &CommandLine,

                                    StringRef InvokedAs) {

  if (CommandLine.empty() || InvokedAs.empty())

    return;

  const auto &Table = driver::getDriverOptTable();

  // --target=X

  StringRef TargetOPT =

      Table.getOption(driver::options::OPT_target).getPrefixedName();

  // -target X

  StringRef TargetOPTLegacy =

      Table.getOption(driver::options::OPT_target_legacy_spelling)

          .getPrefixedName();

  // --driver-mode=X

  StringRef DriverModeOPT =

      Table.getOption(driver::options::OPT_driver_mode).getPrefixedName();

  auto TargetMode =

      driver::ToolChain::getTargetAndModeFromProgramName(InvokedAs);

  // No need to search for target args if we don't have a target/mode to insert.

  bool ShouldAddTarget = TargetMode.TargetIsValid;

  bool ShouldAddMode = TargetMode.DriverMode != nullptr;

  // Skip CommandLine[0].

  for (auto Token = ++CommandLine.begin(); Token != CommandLine.end();

       ++Token) {

    StringRef TokenRef(*Token);

    ShouldAddTarget = ShouldAddTarget && !TokenRef.starts_with(TargetOPT) &&

                      !TokenRef.equals(TargetOPTLegacy);

    ShouldAddMode = ShouldAddMode && !TokenRef.starts_with(DriverModeOPT);

  }

  if (ShouldAddMode) {

    CommandLine.insert(++CommandLine.begin(), TargetMode.DriverMode);

  }

  if (ShouldAddTarget) {

    CommandLine.insert(++CommandLine.begin(),

                       (TargetOPT + TargetMode.TargetPrefix).str());

  }

}

void addExpandedResponseFiles(std::vector<std::string> &CommandLine,

                              llvm::StringRef WorkingDir,

                              llvm::cl::TokenizerCallback Tokenizer,

                              llvm::vfs::FileSystem &FS) {

  bool SeenRSPFile = false;

  llvm::SmallVector<const char *, 20> Argv;

  Argv.reserve(CommandLine.size());

  for (auto &Arg : CommandLine) {

    Argv.push_back(Arg.c_str());

    if (!Arg.empty())

      SeenRSPFile |= Arg.front() == '@';

  }

  if (!SeenRSPFile)

    return;

  llvm::BumpPtrAllocator Alloc;

  llvm::cl::ExpansionContext ECtx(Alloc, Tokenizer);

  llvm::Error Err =

      ECtx.setVFS(&FS).setCurrentDir(WorkingDir).expandResponseFiles(Argv);

  if (Err)

    llvm::errs() << Err;

  // Don't assign directly, Argv aliases CommandLine.

  std::vector<std::string> ExpandedArgv(Argv.begin(), Argv.end());

  CommandLine = std::move(ExpandedArgv);

}

} // namespace tooling

} // namespace clang

namespace {

class SingleFrontendActionFactory : public FrontendActionFactory {

  std::unique_ptr<FrontendAction> Action;

public:

  SingleFrontendActionFactory(std::unique_ptr<FrontendAction> Action)

      : Action(std::move(Action)) {}

  std::unique_ptr<FrontendAction> create() override {

    return std::move(Action);

  }

};

} // namespace

ToolInvocation::ToolInvocation(

    std::vector<std::string> CommandLine, ToolAction *Action,

    FileManager *Files, std::shared_ptr<PCHContainerOperations> PCHContainerOps)

    : CommandLine(std::move(CommandLine)), Action(Action), OwnsAction(false),

      Files(Files), PCHContainerOps(std::move(PCHContainerOps)) {}

ToolInvocation::ToolInvocation(

    std::vector<std::string> CommandLine,

    std::unique_ptr<FrontendAction> FAction, FileManager *Files,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps)

    : CommandLine(std::move(CommandLine)),

      Action(new SingleFrontendActionFactory(std::move(FAction))),

      OwnsAction(true), Files(Files),

      PCHContainerOps(std::move(PCHContainerOps)) {}

ToolInvocation::~ToolInvocation() {

  if (OwnsAction)

    delete Action;

}

bool ToolInvocation::run() {

  llvm::opt::ArgStringList Argv;

  for (const std::string &Str : CommandLine)

    Argv.push_back(Str.c_str());

  const char *const BinaryName = Argv[0];

  // Parse diagnostic options from the driver command-line only if none were

  // explicitly set.

  IntrusiveRefCntPtr<DiagnosticOptions> ParsedDiagOpts;

  DiagnosticOptions *DiagOpts = this->DiagOpts;

  if (!DiagOpts) {

    ParsedDiagOpts = CreateAndPopulateDiagOpts(Argv);

    DiagOpts = &*ParsedDiagOpts;

  }

  TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), DiagOpts);

  IntrusiveRefCntPtr<DiagnosticsEngine> Diagnostics =

      CompilerInstance::createDiagnostics(

          &*DiagOpts, DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);

  // Although `Diagnostics` are used only for command-line parsing, the custom

  // `DiagConsumer` might expect a `SourceManager` to be present.

  SourceManager SrcMgr(*Diagnostics, *Files);

  Diagnostics->setSourceManager(&SrcMgr);

  // We already have a cc1, just create an invocation.

  if (CommandLine.size() >= 2 && CommandLine[1] == "-cc1") {

    ArrayRef<const char *> CC1Args = ArrayRef(Argv).drop_front();

    std::unique_ptr<CompilerInvocation> Invocation(

        newInvocation(&*Diagnostics, CC1Args, BinaryName));

    if (Diagnostics->hasErrorOccurred())

      return false;

    return Action->runInvocation(std::move(Invocation), Files,

                                 std::move(PCHContainerOps), DiagConsumer);

  }

  const std::unique_ptr<driver::Driver> Driver(

      newDriver(&*Diagnostics, BinaryName, &Files->getVirtualFileSystem()));

  // The "input file not found" diagnostics from the driver are useful.

  // The driver is only aware of the VFS working directory, but some clients

  // change this at the FileManager level instead.

  // In this case the checks have false positives, so skip them.

  if (!Files->getFileSystemOpts().WorkingDir.empty())

    Driver->setCheckInputsExist(false);

  const std::unique_ptr<driver::Compilation> Compilation(

      Driver->BuildCompilation(llvm::ArrayRef(Argv)));

  if (!Compilation)

    return false;

  const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(

      &*Diagnostics, Compilation.get());

  if (!CC1Args)

    return false;

  std::unique_ptr<CompilerInvocation> Invocation(

      newInvocation(&*Diagnostics, *CC1Args, BinaryName));

  return runInvocation(BinaryName, Compilation.get(), std::move(Invocation),

                       std::move(PCHContainerOps));

}

bool ToolInvocation::runInvocation(

    const char *BinaryName, driver::Compilation *Compilation,

    std::shared_ptr<CompilerInvocation> Invocation,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {

  // Show the invocation, with -v.

  if (Invocation->getHeaderSearchOpts().Verbose) {

    llvm::errs() << "clang Invocation:\n";

    Compilation->getJobs().Print(llvm::errs(), "\n", true);

    llvm::errs() << "\n";

  }

  return Action->runInvocation(std::move(Invocation), Files,

                               std::move(PCHContainerOps), DiagConsumer);

}

bool FrontendActionFactory::runInvocation(

    std::shared_ptr<CompilerInvocation> Invocation, FileManager *Files,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    DiagnosticConsumer *DiagConsumer) {

  // Create a compiler instance to handle the actual work.

  CompilerInstance Compiler(std::move(PCHContainerOps));

  Compiler.setInvocation(std::move(Invocation));

  Compiler.setFileManager(Files);

  // The FrontendAction can have lifetime requirements for Compiler or its

  // members, and we need to ensure it's deleted earlier than Compiler. So we

  // pass it to an std::unique_ptr declared after the Compiler variable.

  std::unique_ptr<FrontendAction> ScopedToolAction(create());

  // Create the compiler's actual diagnostics engine.

  Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);

  if (!Compiler.hasDiagnostics())

    return false;

  Compiler.createSourceManager(*Files);

  const bool Success = Compiler.ExecuteAction(*ScopedToolAction);

  Files->clearStatCache();

  return Success;

}

ClangTool::ClangTool(const CompilationDatabase &Compilations,

                     ArrayRef<std::string> SourcePaths,

                     std::shared_ptr<PCHContainerOperations> PCHContainerOps,

                     IntrusiveRefCntPtr<llvm::vfs::FileSystem> BaseFS,

                     IntrusiveRefCntPtr<FileManager> Files)

    : Compilations(Compilations), SourcePaths(SourcePaths),

      PCHContainerOps(std::move(PCHContainerOps)),

      OverlayFileSystem(new llvm::vfs::OverlayFileSystem(std::move(BaseFS))),

      InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),

      Files(Files ? Files

                  : new FileManager(FileSystemOptions(), OverlayFileSystem)) {

  OverlayFileSystem->pushOverlay(InMemoryFileSystem);

  appendArgumentsAdjuster(getClangStripOutputAdjuster());

  appendArgumentsAdjuster(getClangSyntaxOnlyAdjuster());

  appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());

  if (Files)

    Files->setVirtualFileSystem(OverlayFileSystem);

}

ClangTool::~ClangTool() = default;

void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {

  MappedFileContents.push_back(std::make_pair(FilePath, Content));

}

void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {

  ArgsAdjuster = combineAdjusters(std::move(ArgsAdjuster), std::move(Adjuster));

}

void ClangTool::clearArgumentsAdjusters() {

  ArgsAdjuster = nullptr;

}

static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,

                              void *MainAddr) {

  // Allow users to override the resource dir.

  for (StringRef Arg : Args)

    if (Arg.starts_with("-resource-dir"))

      return;

  // If there's no override in place add our resource dir.

  Args = getInsertArgumentAdjuster(

      ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))

          .c_str())(Args, "");

}

int ClangTool::run(ToolAction *Action) {

  // Exists solely for the purpose of lookup of the resource path.

  // This just needs to be some symbol in the binary.

  static int StaticSymbol;

  // First insert all absolute paths into the in-memory VFS. These are global

  // for all compile commands.

  if (SeenWorkingDirectories.insert("/").second)

    for (const auto &MappedFile : MappedFileContents)

      if (llvm::sys::path::is_absolute(MappedFile.first))

        InMemoryFileSystem->addFile(

            MappedFile.first, 0,

            llvm::MemoryBuffer::getMemBuffer(MappedFile.second));

  bool ProcessingFailed = false;

  bool FileSkipped = false;

  // Compute all absolute paths before we run any actions, as those will change

  // the working directory.

  std::vector<std::string> AbsolutePaths;

  AbsolutePaths.reserve(SourcePaths.size());

  for (const auto &SourcePath : SourcePaths) {

    auto AbsPath = getAbsolutePath(*OverlayFileSystem, SourcePath);

    if (!AbsPath) {

      llvm::errs() << "Skipping " << SourcePath

                   << ". Error while getting an absolute path: "

                   << llvm::toString(AbsPath.takeError()) << "\n";

      continue;

    }

    AbsolutePaths.push_back(std::move(*AbsPath));

  }

  // Remember the working directory in case we need to restore it.

  std::string InitialWorkingDir;

  if (auto CWD = OverlayFileSystem->getCurrentWorkingDirectory()) {

    InitialWorkingDir = std::move(*CWD);

  } else {

    llvm::errs() << "Could not get working directory: "

                 << CWD.getError().message() << "\n";

  }

  size_t NumOfTotalFiles = AbsolutePaths.size();

  unsigned ProcessedFileCounter = 0;

  for (llvm::StringRef File : AbsolutePaths) {

    // Currently implementations of CompilationDatabase::getCompileCommands can

    // change the state of the file system (e.g.  prepare generated headers), so

    // this method needs to run right before we invoke the tool, as the next

    // file may require a different (incompatible) state of the file system.

    //

    // FIXME: Make the compilation database interface more explicit about the

    // requirements to the order of invocation of its members.

    std::vector<CompileCommand> CompileCommandsForFile =

        Compilations.getCompileCommands(File);

    if (CompileCommandsForFile.empty()) {

      llvm::errs() << "Skipping " << File << ". Compile command not found.\n";

      FileSkipped = true;

      continue;

    }

    for (CompileCommand &CompileCommand : CompileCommandsForFile) {

      // FIXME: chdir is thread hostile; on the other hand, creating the same

      // behavior as chdir is complex: chdir resolves the path once, thus

      // guaranteeing that all subsequent relative path operations work

      // on the same path the original chdir resulted in. This makes a

      // difference for example on network filesystems, where symlinks might be

      // switched during runtime of the tool. Fixing this depends on having a

      // file system abstraction that allows openat() style interactions.

      if (OverlayFileSystem->setCurrentWorkingDirectory(

              CompileCommand.Directory))

        llvm::report_fatal_error("Cannot chdir into \"" +

                                 Twine(CompileCommand.Directory) + "\"!");

      // Now fill the in-memory VFS with the relative file mappings so it will

      // have the correct relative paths. We never remove mappings but that

      // should be fine.

      if (SeenWorkingDirectories.insert(CompileCommand.Directory).second)

        for (const auto &MappedFile : MappedFileContents)

          if (!llvm::sys::path::is_absolute(MappedFile.first))

            InMemoryFileSystem->addFile(

                MappedFile.first, 0,

                llvm::MemoryBuffer::getMemBuffer(MappedFile.second));

      std::vector<std::string> CommandLine = CompileCommand.CommandLine;

      if (ArgsAdjuster)

        CommandLine = ArgsAdjuster(CommandLine, CompileCommand.Filename);

      assert(!CommandLine.empty());

      // Add the resource dir based on the binary of this tool. argv[0] in the

      // compilation database may refer to a different compiler and we want to

      // pick up the very same standard library that compiler is using. The

      // builtin headers in the resource dir need to match the exact clang

      // version the tool is using.

      // FIXME: On linux, GetMainExecutable is independent of the value of the

      // first argument, thus allowing ClangTool and runToolOnCode to just

      // pass in made-up names here. Make sure this works on other platforms.

      injectResourceDir(CommandLine, "clang_tool", &StaticSymbol);

      // FIXME: We need a callback mechanism for the tool writer to output a

      // customized message for each file.

      if (NumOfTotalFiles > 1)

        llvm::errs() << "[" + std::to_string(++ProcessedFileCounter) + "/" +

                            std::to_string(NumOfTotalFiles) +

                            "] Processing file " + File

                     << ".\n";

      ToolInvocation Invocation(std::move(CommandLine), Action, Files.get(),

                                PCHContainerOps);

      Invocation.setDiagnosticConsumer(DiagConsumer);

      if (!Invocation.run()) {

        // FIXME: Diagnostics should be used instead.

        if (PrintErrorMessage)

          llvm::errs() << "Error while processing " << File << ".\n";

        ProcessingFailed = true;

      }

    }

  }

  if (!InitialWorkingDir.empty()) {

    if (auto EC =

            OverlayFileSystem->setCurrentWorkingDirectory(InitialWorkingDir))

      llvm::errs() << "Error when trying to restore working dir: "

                   << EC.message() << "\n";

  }

  return ProcessingFailed ? 1 : (FileSkipped ? 2 : 0);

}

namespace {

class ASTBuilderAction : public ToolAction {

  std::vector<std::unique_ptr<ASTUnit>> &ASTs;

public:

  ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}

  bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,

                     FileManager *Files,

                     std::shared_ptr<PCHContainerOperations> PCHContainerOps,

                     DiagnosticConsumer *DiagConsumer) override {

    std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(

        Invocation, std::move(PCHContainerOps),

        CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts(),

                                            DiagConsumer,

                                            /*ShouldOwnClient=*/false),

        Files);

    if (!AST)

      return false;

    ASTs.push_back(std::move(AST));

    return true;

  }

};

} // namespace

int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {

  ASTBuilderAction Action(ASTs);

  return run(&Action);

}

void ClangTool::setPrintErrorMessage(bool PrintErrorMessage) {

  this->PrintErrorMessage = PrintErrorMessage;

}

namespace clang {

namespace tooling {

std::unique_ptr<ASTUnit>

buildASTFromCode(StringRef Code, StringRef FileName,

                 std::shared_ptr<PCHContainerOperations> PCHContainerOps) {

  return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName,

                                  "clang-tool", std::move(PCHContainerOps));

}

std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(

    StringRef Code, const std::vector<std::string> &Args, StringRef FileName,

    StringRef ToolName, std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    ArgumentsAdjuster Adjuster, const FileContentMappings &VirtualMappedFiles,

    DiagnosticConsumer *DiagConsumer) {

  std::vector<std::unique_ptr<ASTUnit>> ASTs;

  ASTBuilderAction Action(ASTs);

  llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(

      new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));

  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(

      new llvm::vfs::InMemoryFileSystem);

  OverlayFileSystem->pushOverlay(InMemoryFileSystem);

  llvm::IntrusiveRefCntPtr<FileManager> Files(

      new FileManager(FileSystemOptions(), OverlayFileSystem));

  ToolInvocation Invocation(

      getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileName), FileName),

      &Action, Files.get(), std::move(PCHContainerOps));

  Invocation.setDiagnosticConsumer(DiagConsumer);

  InMemoryFileSystem->addFile(FileName, 0,

                              llvm::MemoryBuffer::getMemBufferCopy(Code));

  for (auto &FilenameWithContent : VirtualMappedFiles) {

    InMemoryFileSystem->addFile(

        FilenameWithContent.first, 0,

        llvm::MemoryBuffer::getMemBuffer(FilenameWithContent.second));

  }

  if (!Invocation.run())

    return nullptr;

  assert(ASTs.size() == 1);

  return std::move(ASTs[0]);

}

} // namespace tooling

} // namespace clang