flags/internal/parse.h

0001 //
0002 // Copyright 2019 The Abseil Authors.
0003 //
0004 // Licensed under the Apache License, Version 2.0 (the "License");
0005 // you may not use this file except in compliance with the License.
0006 // You may obtain a copy of the License at
0007 //
0008 //      https://www.apache.org/licenses/LICENSE-2.0
0009 //
0010 // Unless required by applicable law or agreed to in writing, software
0011 // distributed under the License is distributed on an "AS IS" BASIS,
0012 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0013 // See the License for the specific language governing permissions and
0014 // limitations under the License.
0015
0016 #ifndef ABSL_FLAGS_INTERNAL_PARSE_H_
0017 #define ABSL_FLAGS_INTERNAL_PARSE_H_
0018
0019 #include <iostream>
0020 #include <ostream>
0021 #include <string>
0022 #include <vector>
0023
0024 #include "absl/base/config.h"
0025 #include "absl/flags/declare.h"
0026 #include "absl/flags/internal/usage.h"
0027 #include "absl/strings/string_view.h"
0028
0029 ABSL_DECLARE_FLAG(std::vector<std::string>, flagfile);
0030 ABSL_DECLARE_FLAG(std::vector<std::string>, fromenv);
0031 ABSL_DECLARE_FLAG(std::vector<std::string>, tryfromenv);
0032 ABSL_DECLARE_FLAG(std::vector<std::string>, undefok);
0033
0034 namespace absl {
0035 ABSL_NAMESPACE_BEGIN
0036 namespace flags_internal {
0037
0038 enum class UsageFlagsAction { kHandleUsage, kIgnoreUsage };
0039 enum class OnUndefinedFlag {
0040   kIgnoreUndefined,
0041   kReportUndefined,
0042   kAbortIfUndefined
0043 };
0044
0045 // This is not a public interface. This interface exists to expose the ability
0046 // to change help output stream in case of parsing errors. This is used by
0047 // internal unit tests to validate expected outputs.
0048 // When this was written, `EXPECT_EXIT` only supported matchers on stderr,
0049 // but not on stdout.
0050 std::vector<char*> ParseCommandLineImpl(
0051     int argc, char* argv[], UsageFlagsAction usage_flag_action,
0052     OnUndefinedFlag undef_flag_action,
0053     std::ostream& error_help_output = std::cout);
0054
0055 // --------------------------------------------------------------------
0056 // Inspect original command line
0057
0058 // Returns true if flag with specified name was either present on the original
0059 // command line or specified in flag file present on the original command line.
0060 bool WasPresentOnCommandLine(absl::string_view flag_name);
0061
0062 // Return existing flags similar to the parameter, in order to help in case of
0063 // misspellings.
0064 std::vector<std::string> GetMisspellingHints(absl::string_view flag);
0065
0066 }  // namespace flags_internal
0067 ABSL_NAMESPACE_END
0068 }  // namespace absl
0069
0070 #endif  // ABSL_FLAGS_INTERNAL_PARSE_H_