cmd/go: fetch git submodules in `go get`

Change createCmd, downloadCmd, tagSyncCmd, tagSyncDefault to allow
multiple commands.

When using the vendoring experiment, fetch git submodules in `go get`,
and update them in `go get -u`.

This is a reincarnation of https://codereview.appspot.com/142180043.

For #7764.

Change-Id: I8248efb851130620ef762a765ab8716af430572a
Reviewed-on: https://go-review.googlesource.com/9815
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/cmd/go/vcs.go b/src/cmd/go/vcs.go
index d8f8873bbdcd51b0b3799637f894b4da993473b5..5e7619d1da23c3c8eae5e507d9026dd97faef6c4 100644 (file)
--- a/src/cmd/go/vcs.go
+++ b/src/cmd/go/vcs.go
@@ -26,13 +26,13 @@ type vcsCmd struct {
        name string
        cmd  string // name of binary to invoke command
 
-       createCmd   string // command to download a fresh copy of a repository
-       downloadCmd string // command to download updates into an existing repository
+       createCmd   []string // commands to download a fresh copy of a repository
+       downloadCmd []string // commands to download updates into an existing repository
 
        tagCmd         []tagCmd // commands to list tags
        tagLookupCmd   []tagCmd // commands to lookup tags before running tagSyncCmd
-       tagSyncCmd     string   // command to sync to specific tag
-       tagSyncDefault string   // command to sync to default tag
+       tagSyncCmd     []string // commands to sync to specific tag
+       tagSyncDefault []string // commands to sync to default tag
 
        scheme  []string
        pingCmd string
@@ -88,8 +88,8 @@ var vcsHg = &vcsCmd{
        name: "Mercurial",
        cmd:  "hg",
 
-       createCmd:   "clone -U {repo} {dir}",
-       downloadCmd: "pull",
+       createCmd:   []string{"clone -U {repo} {dir}"},
+       downloadCmd: []string{"pull"},
 
        // We allow both tag and branch names as 'tags'
        // for selecting a version.  This lets people have
@@ -100,8 +100,8 @@ var vcsHg = &vcsCmd{
                {"tags", `^(\S+)`},
                {"branches", `^(\S+)`},
        },
-       tagSyncCmd:     "update -r {tag}",
-       tagSyncDefault: "update default",
+       tagSyncCmd:     []string{"update -r {tag}"},
+       tagSyncDefault: []string{"update default"},
 
        scheme:     []string{"https", "http", "ssh"},
        pingCmd:    "identify {scheme}://{repo}",
@@ -121,8 +121,8 @@ var vcsGit = &vcsCmd{
        name: "Git",
        cmd:  "git",
 
-       createCmd:   "clone {repo} {dir}",
-       downloadCmd: "pull --ff-only",
+       createCmd:   []string{"clone {repo} {dir}", "--git-dir={dir}/.git submodule update --init --recursive"},
+       downloadCmd: []string{"pull --ff-only", "submodule update --init --recursive"},
 
        tagCmd: []tagCmd{
                // tags/xxx matches a git tag named xxx
@@ -132,12 +132,12 @@ var vcsGit = &vcsCmd{
        tagLookupCmd: []tagCmd{
                {"show-ref tags/{tag} origin/{tag}", `((?:tags|origin)/\S+)$`},
        },
-       tagSyncCmd: "checkout {tag}",
+       tagSyncCmd: []string{"checkout {tag}", "submodule update --init --recursive"},
        // both createCmd and downloadCmd update the working dir.
        // No need to do more here. We used to 'checkout master'
        // but that doesn't work if the default branch is not named master.
        // See golang.org/issue/9032.
-       tagSyncDefault: "",
+       tagSyncDefault: []string{"checkout master", "submodule update --init --recursive"},
 
        scheme:     []string{"git", "https", "http", "git+ssh"},
        pingCmd:    "ls-remote {scheme}://{repo}",
@@ -178,15 +178,15 @@ var vcsBzr = &vcsCmd{
        name: "Bazaar",
        cmd:  "bzr",
 
-       createCmd: "branch {repo} {dir}",
+       createCmd: []string{"branch {repo} {dir}"},
 
        // Without --overwrite bzr will not pull tags that changed.
        // Replace by --overwrite-tags after http://pad.lv/681792 goes in.
-       downloadCmd: "pull --overwrite",
+       downloadCmd: []string{"pull --overwrite"},
 
        tagCmd:         []tagCmd{{"tags", `^(\S+)`}},
-       tagSyncCmd:     "update -r {tag}",
-       tagSyncDefault: "update -r revno:-1",
+       tagSyncCmd:     []string{"update -r {tag}"},
+       tagSyncDefault: []string{"update -r revno:-1"},
 
        scheme:      []string{"https", "http", "bzr", "bzr+ssh"},
        pingCmd:     "info {scheme}://{repo}",
@@ -240,8 +240,8 @@ var vcsSvn = &vcsCmd{
        name: "Subversion",
        cmd:  "svn",
 
-       createCmd:   "checkout {repo} {dir}",
-       downloadCmd: "update",
+       createCmd:   []string{"checkout {repo} {dir}"},
+       downloadCmd: []string{"update"},
 
        // There is no tag command in subversion.
        // The branch information is all in the path names.
@@ -352,7 +352,15 @@ func (v *vcsCmd) ping(scheme, repo string) error {
 // create creates a new copy of repo in dir.
 // The parent of dir must exist; dir must not.
 func (v *vcsCmd) create(dir, repo string) error {
-       return v.run(".", v.createCmd, "dir", dir, "repo", repo)
+       for _, cmd := range v.createCmd {
+               if !go15VendorExperiment && strings.Contains(cmd, "submodule") {
+                       continue
+               }
+               if err := v.run(".", cmd, "dir", dir, "repo", repo); err != nil {
+                       return err
+               }
+       }
+       return nil
 }
 
 // download downloads any new changes for the repo in dir.
@@ -360,7 +368,15 @@ func (v *vcsCmd) download(dir string) error {
        if err := v.fixDetachedHead(dir); err != nil {
                return err
        }
-       return v.run(dir, v.downloadCmd)
+       for _, cmd := range v.downloadCmd {
+               if !go15VendorExperiment && strings.Contains(cmd, "submodule") {
+                       continue
+               }
+               if err := v.run(dir, cmd); err != nil {
+                       return err
+               }
+       }
+       return nil
 }
 
 // fixDetachedHead switches a Git repository in dir from a detached head to the master branch.
@@ -406,7 +422,7 @@ func (v *vcsCmd) tags(dir string) ([]string, error) {
 // tagSync syncs the repo in dir to the named tag,
 // which either is a tag returned by tags or is v.tagDefault.
 func (v *vcsCmd) tagSync(dir, tag string) error {
-       if v.tagSyncCmd == "" {
+       if v.tagSyncCmd == nil {
                return nil
        }
        if tag != "" {
@@ -423,10 +439,28 @@ func (v *vcsCmd) tagSync(dir, tag string) error {
                        }
                }
        }
-       if tag == "" && v.tagSyncDefault != "" {
-               return v.run(dir, v.tagSyncDefault)
+
+       if tag == "" && v.tagSyncDefault != nil {
+               for _, cmd := range v.tagSyncDefault {
+                       if !go15VendorExperiment && strings.Contains(cmd, "submodule") {
+                               continue
+                       }
+                       if err := v.run(dir, cmd); err != nil {
+                               return err
+                       }
+               }
+               return nil
+       }
+
+       for _, cmd := range v.tagSyncCmd {
+               if !go15VendorExperiment && strings.Contains(cmd, "submodule") {
+                       continue
+               }
+               if err := v.run(dir, cmd, "tag", tag); err != nil {
+                       return err
+               }
        }
-       return v.run(dir, v.tagSyncCmd, "tag", tag)
+       return nil
 }
 
 // A vcsPath describes how to convert an import path into a