1/*
2 * Copyright 2015-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#pragma once
18
19#include <boost/program_options.hpp>
20
21#include <folly/Optional.h>
22#include <folly/portability/GFlags.h>
23
24namespace folly {
25
26enum class ProgramOptionsStyle {
27 GFLAGS,
28 GNU,
29};
30
31// Add all GFlags to the given options_description.
32// Use this *instead of* gflags::ParseCommandLineFlags().
33//
34// in GFLAGS style, the flags are named as per gflags conventions:
35// names_with_underscores
36// boolean flags have a "no" prefix
37//
38// in GNU style, the flags are named as per GNU conventions:
39// names-with-dashes
40// boolean flags have a "no-" prefix
41//
42// Consider (for example) a boolean flag:
43// DEFINE_bool(flying_pigs, false, "...");
44//
45// In GFLAGS style, the corresponding flags are named
46// flying_pigs
47// noflying_pigs
48//
49// In GNU style, the corresponding flags are named
50// flying-pigs
51// no-flying-pigs
52//
53// You may not pass arguments to boolean flags, so you must use the
54// "no" / "no-" prefix to set them to false; "--flying_pigs false"
55// and "--flying_pigs=false" are not allowed, to prevent ambiguity.
56boost::program_options::options_description getGFlags(
57 ProgramOptionsStyle style = ProgramOptionsStyle::GNU);
58
59// Helper when parsing nested command lines:
60//
61// program [--common_options...] command [--command_options...] args
62//
63// The result has "command" set to the first positional argument, if any,
64// and "rest" set to the remaining options and arguments. Note that any
65// unrecognized flags must appear after the command name.
66//
67// You may pass "rest" to parseNestedCommandLine again, etc.
68struct NestedCommandLineParseResult {
69 NestedCommandLineParseResult() {}
70
71 boost::program_options::parsed_options options{nullptr};
72
73 Optional<std::string> command;
74 std::vector<std::string> rest;
75};
76
77NestedCommandLineParseResult parseNestedCommandLine(
78 int argc,
79 const char* const argv[],
80 const boost::program_options::options_description& desc);
81
82NestedCommandLineParseResult parseNestedCommandLine(
83 const std::vector<std::string>& cmdline,
84 const boost::program_options::options_description& desc);
85
86} // namespace folly
87