1*1c12ee1eSDan Willemsen// Copyright 2019 The Go Authors. All rights reserved. 2*1c12ee1eSDan Willemsen// Use of this source code is governed by a BSD-style 3*1c12ee1eSDan Willemsen// license that can be found in the LICENSE file. 4*1c12ee1eSDan Willemsen 5*1c12ee1eSDan Willemsenpackage protoimpl 6*1c12ee1eSDan Willemsen 7*1c12ee1eSDan Willemsenimport ( 8*1c12ee1eSDan Willemsen "google.golang.org/protobuf/internal/version" 9*1c12ee1eSDan Willemsen) 10*1c12ee1eSDan Willemsen 11*1c12ee1eSDan Willemsenconst ( 12*1c12ee1eSDan Willemsen // MaxVersion is the maximum supported version for generated .pb.go files. 13*1c12ee1eSDan Willemsen // It is always the current version of the module. 14*1c12ee1eSDan Willemsen MaxVersion = version.Minor 15*1c12ee1eSDan Willemsen 16*1c12ee1eSDan Willemsen // GenVersion is the runtime version required by generated .pb.go files. 17*1c12ee1eSDan Willemsen // This is incremented when generated code relies on new functionality 18*1c12ee1eSDan Willemsen // in the runtime. 19*1c12ee1eSDan Willemsen GenVersion = 20 20*1c12ee1eSDan Willemsen 21*1c12ee1eSDan Willemsen // MinVersion is the minimum supported version for generated .pb.go files. 22*1c12ee1eSDan Willemsen // This is incremented when the runtime drops support for old code. 23*1c12ee1eSDan Willemsen MinVersion = 0 24*1c12ee1eSDan Willemsen) 25*1c12ee1eSDan Willemsen 26*1c12ee1eSDan Willemsen// EnforceVersion is used by code generated by protoc-gen-go 27*1c12ee1eSDan Willemsen// to statically enforce minimum and maximum versions of this package. 28*1c12ee1eSDan Willemsen// A compilation failure implies either that: 29*1c12ee1eSDan Willemsen// - the runtime package is too old and needs to be updated OR 30*1c12ee1eSDan Willemsen// - the generated code is too old and needs to be regenerated. 31*1c12ee1eSDan Willemsen// 32*1c12ee1eSDan Willemsen// The runtime package can be upgraded by running: 33*1c12ee1eSDan Willemsen// 34*1c12ee1eSDan Willemsen// go get google.golang.org/protobuf 35*1c12ee1eSDan Willemsen// 36*1c12ee1eSDan Willemsen// The generated code can be regenerated by running: 37*1c12ee1eSDan Willemsen// 38*1c12ee1eSDan Willemsen// protoc --go_out=${PROTOC_GEN_GO_ARGS} ${PROTO_FILES} 39*1c12ee1eSDan Willemsen// 40*1c12ee1eSDan Willemsen// Example usage by generated code: 41*1c12ee1eSDan Willemsen// 42*1c12ee1eSDan Willemsen// const ( 43*1c12ee1eSDan Willemsen// // Verify that this generated code is sufficiently up-to-date. 44*1c12ee1eSDan Willemsen// _ = protoimpl.EnforceVersion(genVersion - protoimpl.MinVersion) 45*1c12ee1eSDan Willemsen// // Verify that runtime/protoimpl is sufficiently up-to-date. 46*1c12ee1eSDan Willemsen// _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - genVersion) 47*1c12ee1eSDan Willemsen// ) 48*1c12ee1eSDan Willemsen// 49*1c12ee1eSDan Willemsen// The genVersion is the current minor version used to generated the code. 50*1c12ee1eSDan Willemsen// This compile-time check relies on negative integer overflow of a uint 51*1c12ee1eSDan Willemsen// being a compilation failure (guaranteed by the Go specification). 52*1c12ee1eSDan Willemsentype EnforceVersion uint 53*1c12ee1eSDan Willemsen 54*1c12ee1eSDan Willemsen// This enforces the following invariant: 55*1c12ee1eSDan Willemsen// 56*1c12ee1eSDan Willemsen// MinVersion ≤ GenVersion ≤ MaxVersion 57*1c12ee1eSDan Willemsenconst ( 58*1c12ee1eSDan Willemsen _ = EnforceVersion(GenVersion - MinVersion) 59*1c12ee1eSDan Willemsen _ = EnforceVersion(MaxVersion - GenVersion) 60*1c12ee1eSDan Willemsen) 61