tool_support.h

// Copyright 2014 The Crashpad Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef CRASHPAD_TOOLS_TOOL_SUPPORT_H_
#define CRASHPAD_TOOLS_TOOL_SUPPORT_H_

#include <string>

#include "base/files/file_path.h"
#include "base/strings/string_piece.h"
#include "build/build_config.h"

namespace crashpad {

//! \brief Common functions used by command line tools.
class ToolSupport {
 public:
  ToolSupport() = delete;
  ToolSupport(const ToolSupport&) = delete;
  ToolSupport& operator=(const ToolSupport&) = delete;

  //! \brief Handles `--version`.
  //!
  //! \param[in] me The tool’s name, the basename of `argv[0]`.
  static void Version(const base::FilePath& me);

  //! \brief Prints the footer for `--help`.
  //!
  //! \param[in] me The tool’s name, the basename of `argv[0]`.
  static void UsageTail(const base::FilePath& me);

  //! \brief Suggests using `--help` when a command line tool can’t make sense
  //!     of its arguments.
  //!
  //! \param[in] me The tool’s name, the basename of `argv[0]`.
  //! \param[in] hint A hint to display before the suggestion to try `--help`.
  //!     Optional, may be `nullptr`, in which case no hint will be presented.
  static void UsageHint(const base::FilePath& me, const char* hint);

#if BUILDFLAG(IS_POSIX) || DOXYGEN
  //! \copydoc Version
  static void Version(const std::string& me);

  //! \copydoc UsageTail
  static void UsageTail(const std::string& me);

  //! \copydoc UsageHint
  static void UsageHint(const std::string& me, const char* hint);
#endif  // BUILDFLAG(IS_POSIX)

#if BUILDFLAG(IS_WIN) || DOXYGEN
  //! \brief Converts \a argv `wchar_t` UTF-16 to UTF-8, and passes onwards to a
  //!     UTF-8 entry point.
  //!
  //! \return The return value of \a entry.
  static int Wmain(int argc, wchar_t* argv[], int (*entry)(int, char*[]));
#endif  // BUILDFLAG(IS_WIN)

  //! \brief Converts a command line argument to the string type suitable for
  //!     base::FilePath.
  //!
  //! On POSIX, this is a no-op. On Windows, assumes that Wmain() was used, and
  //! the input argument was converted from UTF-16 in a `wchar_t*` to UTF-8 in a
  //! `char*`. This undoes that transformation.
  //!
  //! \sa Wmain()
  //! \sa FilePathToCommandLineArgument()
  static base::FilePath::StringType CommandLineArgumentToFilePathStringType(
      const base::StringPiece& arg);

  //! \brief Converts a base::FilePath to a command line argument.
  //!
  //! On POSIX, this is a no-op. On Windows, this undoes the transformation done
  //! by CommandLineArgumentToFilePathStringType() in the same manner as
  //! Wmain().
  static std::string FilePathToCommandLineArgument(
      const base::FilePath& file_path);
};

}  // namespace crashpad

#endif  // CRASHPAD_TOOLS_TOOL_SUPPORT_H_