1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // From: util/task/contrib/status_macros/status_macros.h 32 33 #ifndef GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_ 34 #define GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_ 35 36 #include <google/protobuf/stubs/common.h> 37 #include <google/protobuf/stubs/status.h> 38 #include <google/protobuf/stubs/statusor.h> 39 40 namespace google { 41 namespace protobuf { 42 namespace util { 43 44 // Run a command that returns a util::Status. If the called code returns an 45 // error status, return that status up out of this method too. 46 // 47 // Example: 48 // RETURN_IF_ERROR(DoThings(4)); 49 #define RETURN_IF_ERROR(expr) \ 50 do { \ 51 /* Using _status below to avoid capture problems if expr is "status". */ \ 52 const ::google::protobuf::util::Status _status = (expr); \ 53 if (GOOGLE_PREDICT_FALSE(!_status.ok())) return _status; \ 54 } while (0) 55 56 // Internal helper for concatenating macro values. 57 #define STATUS_MACROS_CONCAT_NAME_INNER(x, y) x##y 58 #define STATUS_MACROS_CONCAT_NAME(x, y) STATUS_MACROS_CONCAT_NAME_INNER(x, y) 59 60 template<typename T> 61 Status DoAssignOrReturn(T& lhs, StatusOr<T> result) { 62 if (result.ok()) { 63 lhs = result.ValueOrDie(); 64 } 65 return result.status(); 66 } 67 68 #define ASSIGN_OR_RETURN_IMPL(status, lhs, rexpr) \ 69 Status status = DoAssignOrReturn(lhs, (rexpr)); \ 70 if (GOOGLE_PREDICT_FALSE(!status.ok())) return status; 71 72 // Executes an expression that returns a util::StatusOr, extracting its value 73 // into the variable defined by lhs (or returning on error). 74 // 75 // Example: Assigning to an existing value 76 // ValueType value; 77 // ASSIGN_OR_RETURN(value, MaybeGetValue(arg)); 78 // 79 // WARNING: ASSIGN_OR_RETURN expands into multiple statements; it cannot be used 80 // in a single statement (e.g. as the body of an if statement without {})! 81 #define ASSIGN_OR_RETURN(lhs, rexpr) \ 82 ASSIGN_OR_RETURN_IMPL( \ 83 STATUS_MACROS_CONCAT_NAME(_status_or_value, __COUNTER__), lhs, rexpr); 84 85 } // namespace util 86 } // namespace protobuf 87 } // namespace google 88 89 #endif // GOOGLE_PROTOBUF_STUBS_STATUS_H_ 90
