blob: ff094e1ba44b297d717b2c53a9584b317bcd12ac [file] [log] [blame]
mpagenkoaf801632020-07-03 10:00:42 +00001// 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
5package protoimpl
6
7import (
8 "google.golang.org/protobuf/internal/version"
9)
10
11const (
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// go get google.golang.org/protobuf
34//
35// The generated code can be regenerated by running:
36// protoc --go_out=${PROTOC_GEN_GO_ARGS} ${PROTO_FILES}
37//
38// Example usage by generated code:
39// const (
40// // Verify that this generated code is sufficiently up-to-date.
41// _ = protoimpl.EnforceVersion(genVersion - protoimpl.MinVersion)
42// // Verify that runtime/protoimpl is sufficiently up-to-date.
43// _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - genVersion)
44// )
45//
46// The genVersion is the current minor version used to generated the code.
47// This compile-time check relies on negative integer overflow of a uint
48// being a compilation failure (guaranteed by the Go specification).
49type EnforceVersion uint
50
51// This enforces the following invariant:
52// MinVersion ≤ GenVersion ≤ MaxVersion
53const (
54 _ = EnforceVersion(GenVersion - MinVersion)
55 _ = EnforceVersion(MaxVersion - GenVersion)
56)