1 /* 2 * Copyright (C) 2015 The Android Open Source Project 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 #ifndef ART_CMDLINE_CMDLINE_RESULT_H_ 18 #define ART_CMDLINE_CMDLINE_RESULT_H_ 19 20 #include <assert.h> 21 #include "base/utils.h" 22 23 namespace art { 24 // Result of an attempt to process the command line arguments. If fails, specifies 25 // the specific error code and an error message. 26 // Use the value-carrying CmdlineParseResult<T> to get an additional value out in a success case. 27 struct CmdlineResult { 28 enum Status { 29 kSuccess, 30 // Error codes: 31 kUsage, 32 kFailure, 33 kOutOfRange, 34 kUnknown, 35 }; 36 37 // Short-hand for checking if the result was successful. 38 operator bool() const { 39 return IsSuccess(); 40 } 41 42 // Check if the operation has succeeded. IsSuccessCmdlineResult43 bool IsSuccess() const { return status_ == kSuccess; } 44 // Check if the operation was not a success. IsErrorCmdlineResult45 bool IsError() const { return status_ != kSuccess; } 46 // Get the specific status, regardless of whether it's failure or success. GetStatusCmdlineResult47 Status GetStatus() const { return status_; } 48 49 // Get the error message, *must* only be called for error status results. GetMessageCmdlineResult50 const std::string& GetMessage() const { assert(IsError()); return message_; } 51 52 // Constructor any status. No message. CmdlineResultCmdlineResult53 explicit CmdlineResult(Status status) : status_(status) {} 54 55 // Constructor with an error status, copying the message. CmdlineResultCmdlineResult56 CmdlineResult(Status status, const std::string& message) 57 : status_(status), message_(message) { 58 assert(status != kSuccess); 59 } 60 61 // Constructor with an error status, taking over the message. CmdlineResultCmdlineResult62 CmdlineResult(Status status, std::string&& message) 63 : status_(status), message_(message) { 64 assert(status != kSuccess); 65 } 66 67 // Make sure copying exists 68 CmdlineResult(const CmdlineResult&) = default; 69 // Make sure moving is cheap 70 CmdlineResult(CmdlineResult&&) = default; 71 72 private: 73 const Status status_; 74 const std::string message_; 75 }; 76 77 // TODO: code-generate this 78 static inline std::ostream& operator<<(std::ostream& stream, CmdlineResult::Status status) { 79 switch (status) { 80 case CmdlineResult::kSuccess: 81 stream << "kSuccess"; 82 break; 83 case CmdlineResult::kUsage: 84 stream << "kUsage"; 85 break; 86 case CmdlineResult::kFailure: 87 stream << "kFailure"; 88 break; 89 case CmdlineResult::kOutOfRange: 90 stream << "kOutOfRange"; 91 break; 92 case CmdlineResult::kUnknown: 93 stream << "kUnknown"; 94 break; 95 default: 96 UNREACHABLE(); 97 } 98 return stream; 99 } 100 } // namespace art 101 102 #endif // ART_CMDLINE_CMDLINE_RESULT_H_ 103