//===--- CompileInstance.h ------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2021 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#ifndef SWIFT_IDE_COMPILEINSTANCE_H
#define SWIFT_IDE_COMPILEINSTANCE_H

#include "swift/Frontend/Frontend.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Chrono.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/VirtualFileSystem.h"

namespace swift {

class CompilerInstance;
class CompilerInvocation;
class DiagnosticConsumer;

namespace ide {

/// Manages \c CompilerInstance for completion like operations.
class CompileInstance {
  const std::string &RuntimeResourcePath;
  const std::string &DiagnosticDocumentationPath;

  struct Options {
    unsigned MaxASTReuseCount = 100;
  } Opts;

  std::mutex mtx;

  std::unique_ptr<CompilerInstance> CI;
  llvm::hash_code CachedArgHash;
  std::atomic<bool> CachedCIInvalidated;
  unsigned CachedReuseCount;

  /// Perform cached sema. Returns \c true if the CI is not reusable.
  bool performCachedSemaIfPossible(DiagnosticConsumer *DiagC);

  /// Setup the CI with \p Args . Returns \c true if failed.
  bool setupCI(llvm::ArrayRef<const char *> Args,
                 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FileSystem,
                 DiagnosticConsumer *DiagC);

  /// Perform Parse and Sema, potentially CI from previous compilation is
  /// reused.
  void performSema(llvm::ArrayRef<const char *> Args,
                   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FileSystem,
                   DiagnosticConsumer *DiagC,
                   std::shared_ptr<std::atomic<bool>> CancellationFlag);

public:
  CompileInstance(const std::string &RuntimeResourcePath,
                  const std::string &DiagnosticDocumentationPath)
      : RuntimeResourcePath(RuntimeResourcePath),
        DiagnosticDocumentationPath(DiagnosticDocumentationPath),
        CachedCIInvalidated(false), CachedReuseCount(0) {}

  /// NOTE: \p Args is only used for checking the equaity of the invocation.
  /// Since this function assumes that it is already normalized, exact the same
  /// arguments including their order is considered as the same invocation.
  bool
  performCompile(llvm::ArrayRef<const char *> Args,
                 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FileSystem,
                 DiagnosticConsumer *DiagC,
                 std::shared_ptr<std::atomic<bool>> CancellationFlag);
};

} // namespace ide
} // namespace swift

#endif // SWIFT_IDE_COMPILEINSTANCE_H