libgo/go/cmd/go/internal/modcmd/tidy.go

   1 // Copyright 2018 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 // go mod tidy
   6
   7 package modcmd
   8
   9 import (
  10         "cmd/go/internal/base"
  11         "cmd/go/internal/cfg"
  12         "cmd/go/internal/imports"
  13         "cmd/go/internal/modload"
  14         "context"
  15         "fmt"
  16
  17         "golang.org/x/mod/modfile"
  18         "golang.org/x/mod/semver"
  19 )
  20
  21 var cmdTidy = &base.Command{
  22         UsageLine: "go mod tidy [-e] [-v] [-go=version] [-compat=version]",
  23         Short:     "add missing and remove unused modules",
  24         Long: `
  25 Tidy makes sure go.mod matches the source code in the module.
  26 It adds any missing modules necessary to build the current module's
  27 packages and dependencies, and it removes unused modules that
  28 don't provide any relevant packages. It also adds any missing entries
  29 to go.sum and removes any unnecessary ones.
  30
  31 The -v flag causes tidy to print information about removed modules
  32 to standard error.
  33
  34 The -e flag causes tidy to attempt to proceed despite errors
  35 encountered while loading packages.
  36
  37 The -go flag causes tidy to update the 'go' directive in the go.mod
  38 file to the given version, which may change which module dependencies
  39 are retained as explicit requirements in the go.mod file.
  40 (Go versions 1.17 and higher retain more requirements in order to
  41 support lazy module loading.)
  42
  43 The -compat flag preserves any additional checksums needed for the
  44 'go' command from the indicated major Go release to successfully load
  45 the module graph, and causes tidy to error out if that version of the
  46 'go' command would load any imported package from a different module
  47 version. By default, tidy acts as if the -compat flag were set to the
  48 version prior to the one indicated by the 'go' directive in the go.mod
  49 file.
  50
  51 See https://golang.org/ref/mod#go-mod-tidy for more about 'go mod tidy'.
  52         `,
  53         Run: runTidy,
  54 }
  55
  56 var (
  57         tidyE      bool          // if true, report errors but proceed anyway.
  58         tidyGo     goVersionFlag // go version to write to the tidied go.mod file (toggles lazy loading)
  59         tidyCompat goVersionFlag // go version for which the tidied go.mod and go.sum files should be “compatible”
  60 )
  61
  62 func init() {
  63         cmdTidy.Flag.BoolVar(&cfg.BuildV, "v", false, "")
  64         cmdTidy.Flag.BoolVar(&tidyE, "e", false, "")
  65         cmdTidy.Flag.Var(&tidyGo, "go", "")
  66         cmdTidy.Flag.Var(&tidyCompat, "compat", "")
  67         base.AddModCommonFlags(&cmdTidy.Flag)
  68 }
  69
  70 // A goVersionFlag is a flag.Value representing a supported Go version.
  71 //
  72 // (Note that the -go argument to 'go mod edit' is *not* a goVersionFlag.
  73 // It intentionally allows newer-than-supported versions as arguments.)
  74 type goVersionFlag struct {
  75         v string
  76 }
  77
  78 func (f *goVersionFlag) String() string { return f.v }
  79 func (f *goVersionFlag) Get() any       { return f.v }
  80
  81 func (f *goVersionFlag) Set(s string) error {
  82         if s != "" {
  83                 latest := modload.LatestGoVersion()
  84                 if !modfile.GoVersionRE.MatchString(s) {
  85                         return fmt.Errorf("expecting a Go version like %q", latest)
  86                 }
  87                 if semver.Compare("v"+s, "v"+latest) > 0 {
  88                         return fmt.Errorf("maximum supported Go version is %s", latest)
  89                 }
  90         }
  91
  92         f.v = s
  93         return nil
  94 }
  95
  96 func runTidy(ctx context.Context, cmd *base.Command, args []string) {
  97         if len(args) > 0 {
  98                 base.Fatalf("go: 'go mod tidy' accepts no arguments")
  99         }
 100
 101         // Tidy aims to make 'go test' reproducible for any package in 'all', so we
 102         // need to include test dependencies. For modules that specify go 1.15 or
 103         // earlier this is a no-op (because 'all' saturates transitive test
 104         // dependencies).
 105         //
 106         // However, with lazy loading (go 1.16+) 'all' includes only the packages that
 107         // are transitively imported by the main module, not the test dependencies of
 108         // those packages. In order to make 'go test' reproducible for the packages
 109         // that are in 'all' but outside of the main module, we must explicitly
 110         // request that their test dependencies be included.
 111         modload.ForceUseModules = true
 112         modload.RootMode = modload.NeedRoot
 113
 114         modload.LoadPackages(ctx, modload.PackageOpts{
 115                 GoVersion:                tidyGo.String(),
 116                 Tags:                     imports.AnyTags(),
 117                 Tidy:                     true,
 118                 TidyCompatibleVersion:    tidyCompat.String(),
 119                 VendorModulesInGOROOTSrc: true,
 120                 ResolveMissingImports:    true,
 121                 LoadTests:                true,
 122                 AllowErrors:              tidyE,
 123                 SilenceMissingStdImports: true,
 124         }, "all")
 125 }