gflags_compat.h

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/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * 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.
 */
 
#pragma once
 
#include <optional>
#include <ostream>
#include <string>
#include <vector>
 
#include "cuttlefish/flag_parser/flag.h"
 
namespace cuttlefish {
 
/* Write gflags `--helpxml` style output for a string-type flag. */
void WriteGflagsCompatXml(const Flag&, std::ostream&);
void WriteGflagsCompatXml(const std::vector<Flag>&, std::ostream&);
 
// Create a flag resembling a gflags argument of the given type. This includes
// "-[-]flag=*",support for all types, "-[-]noflag" support for booleans, and
// "-flag *", "--flag *", support for other types. The value passed in the flag
// is saved to the defined reference.
Flag GflagsCompatFlag(const std::string& name, std::string& value);
Flag GflagsCompatFlag(const std::string& name, int32_t& value);
Flag GflagsCompatFlag(const std::string& name, size_t& value);
Flag GflagsCompatFlag(const std::string& name, bool& value);
Flag GflagsCompatFlag(const std::string& name, std::vector<std::string>& value);
Flag GflagsCompatFlag(const std::string& name, std::vector<unsigned>& value);
Flag GflagsCompatFlag(const std::string& name, std::vector<bool>& value,
                      bool default_value);
// Indicates when to assign std::nullopt to the std::optional backing the flag.
enum class CoerceToNullopt {
  None,          // When the flag is not present in the arguments
  UnsetKeyword,  // When the flag has the "unset" special value.
  EmptyString,   // When the flag has an empty value (`--flag "" or `--flag=`)
};
Flag GflagsCompatFlag(const std::string& name,
                      std::optional<std::string>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name, std::optional<int>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name, std::optional<size_t>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name, std::optional<unsigned>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name, std::optional<int64_t>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name, std::optional<bool>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
 
Flag GflagsCompatFlag(const std::string& name,
                      std::optional<std::vector<std::string>>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
Flag GflagsCompatFlag(const std::string& name,
                      std::optional<std::vector<unsigned>>& value,
                      CoerceToNullopt opt = CoerceToNullopt::None);
 
/* If a "-help" or "--help" flag is present, prints all the flags and fails. */
Flag HelpFlag(const std::vector<Flag>& flags, std::string text = "");
 
/* If a "-helpxml" is present, prints all the flags in XML and fails. */
Flag HelpXmlFlag(const std::vector<Flag>& flags, std::ostream&, bool& print_xml,
                 std::string text = "");
 
}  // namespace cuttlefish