1 // Copyright 2019 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package protoimpl 6 7 import ( 8 "google.golang.org/protobuf/internal/version" 9 ) 10 11 const ( 12 // MaxVersion is the maximum supported version for generated .pb.go files. 13 // It is always the current version of the module. 14 MaxVersion = version.Minor 15 16 // GenVersion is the runtime version required by generated .pb.go files. 17 // This is incremented when generated code relies on new functionality 18 // in the runtime. 19 GenVersion = 20 20 21 // MinVersion is the minimum supported version for generated .pb.go files. 22 // This is incremented when the runtime drops support for old code. 23 MinVersion = 0 24 ) 25 26 // EnforceVersion is used by code generated by protoc-gen-go 27 // to statically enforce minimum and maximum versions of this package. 28 // A compilation failure implies either that: 29 // - the runtime package is too old and needs to be updated OR 30 // - the generated code is too old and needs to be regenerated. 31 // 32 // The runtime package can be upgraded by running: 33 // 34 // go get google.golang.org/protobuf 35 // 36 // The generated code can be regenerated by running: 37 // 38 // protoc --go_out=${PROTOC_GEN_GO_ARGS} ${PROTO_FILES} 39 // 40 // Example usage by generated code: 41 // 42 // const ( 43 // // Verify that this generated code is sufficiently up-to-date. 44 // _ = protoimpl.EnforceVersion(genVersion - protoimpl.MinVersion) 45 // // Verify that runtime/protoimpl is sufficiently up-to-date. 46 // _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - genVersion) 47 // ) 48 // 49 // The genVersion is the current minor version used to generated the code. 50 // This compile-time check relies on negative integer overflow of a uint 51 // being a compilation failure (guaranteed by the Go specification). 52 type EnforceVersion uint 53 54 // This enforces the following invariant: 55 // 56 // MinVersion ≤ GenVersion ≤ MaxVersion 57 const ( 58 _ = EnforceVersion(GenVersion - MinVersion) 59 _ = EnforceVersion(MaxVersion - GenVersion) 60 ) 61