//===- DependencyScanningWorker.h - clang-scan-deps worker ===---*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLING_DEPENDENCYSCANNING_DEPENDENCYSCANNINGWORKER_H
#define LLVM_CLANG_TOOLING_DEPENDENCYSCANNING_DEPENDENCYSCANNINGWORKER_H

#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/LLVM.h"
#include "clang/Frontend/PCHContainerOperations.h"
#include "clang/Tooling/DependencyScanning/DependencyScanningService.h"
#include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
#include <string>

namespace clang {

class DependencyOutputOptions;

namespace tooling {
namespace dependencies {

class DependencyScanningWorkerFilesystem;

/// A command-line tool invocation that is part of building a TU.
///
/// \see FullDependencies::Commands.
struct Command {
  std::string Executable;
  std::vector<std::string> Arguments;
};

class DependencyConsumer {
public:
  virtual ~DependencyConsumer() {}

  virtual void handleBuildCommand(Command Cmd) = 0;

  virtual void
  handleDependencyOutputOpts(const DependencyOutputOptions &Opts) = 0;

  virtual void handleFileDependency(StringRef Filename) = 0;

  virtual void handlePrebuiltModuleDependency(PrebuiltModuleDep PMD) = 0;

  virtual void handleModuleDependency(ModuleDeps MD) = 0;

  virtual void handleContextHash(std::string Hash) = 0;

  virtual std::string lookupModuleOutput(const ModuleID &ID,
                                         ModuleOutputKind Kind) = 0;
};

/// An individual dependency scanning worker that is able to run on its own
/// thread.
///
/// The worker computes the dependencies for the input files by preprocessing
/// sources either using a fast mode where the source files are minimized, or
/// using the regular processing run.
class DependencyScanningWorker {
public:
  DependencyScanningWorker(DependencyScanningService &Service,
                           llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS);

  /// Run the dependency scanning tool for a given clang driver command-line,
  /// and report the discovered dependencies to the provided consumer. If \p
  /// ModuleName isn't empty, this function reports the dependencies of module
  /// \p ModuleName.
  ///
  /// \returns false if clang errors occurred (with diagnostics reported to
  /// \c DiagConsumer), true otherwise.
  bool computeDependencies(StringRef WorkingDirectory,
                           const std::vector<std::string> &CommandLine,
                           DependencyConsumer &DepConsumer,
                           DiagnosticConsumer &DiagConsumer,
                           llvm::Optional<StringRef> ModuleName = None);
  /// \returns A \c StringError with the diagnostic output if clang errors
  /// occurred, success otherwise.
  llvm::Error computeDependencies(StringRef WorkingDirectory,
                                  const std::vector<std::string> &CommandLine,
                                  DependencyConsumer &Consumer,
                                  llvm::Optional<StringRef> ModuleName = None);

  bool shouldEagerLoadModules() const { return EagerLoadModules; }

private:
  std::shared_ptr<PCHContainerOperations> PCHContainerOps;

  /// The physical filesystem overlaid by `InMemoryFS`.
  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> RealFS;
  /// The in-memory filesystem laid on top the physical filesystem in `RealFS`.
  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFS;
  /// The file system that is used by each worker when scanning for
  /// dependencies. This filesystem persists across multiple compiler
  /// invocations.
  llvm::IntrusiveRefCntPtr<DependencyScanningWorkerFilesystem> DepFS;
  ScanningOutputFormat Format;
  /// Whether to optimize the modules' command-line arguments.
  bool OptimizeArgs;
  /// Whether to set up command-lines to load PCM files eagerly.
  bool EagerLoadModules;
};

} // end namespace dependencies
} // end namespace tooling
} // end namespace clang

#endif // LLVM_CLANG_TOOLING_DEPENDENCYSCANNING_DEPENDENCYSCANNINGWORKER_H