cmd/go/internal/vcs: include Subversion VCS build information

src/cmd/go/internal/vcs/vcs.go

@@ -498,6 +498,7 @@ var vcsSvn = &Cmd{
 	Scheme:     []string{"https", "http", "svn", "svn+ssh"},
 	PingCmd:    "info -- {scheme}://{repo}",
 	RemoteRepo: svnRemoteRepo,
+	Status:     svnStatus,
 }
 
 func svnRemoteRepo(vcsSvn *Cmd, rootDir string) (remoteRepo string, err error) {
@@ -530,6 +531,35 @@ func svnRemoteRepo(vcsSvn *Cmd, rootDir string) (remoteRepo string, err error) {
 	return strings.TrimSpace(out), nil
 }
 
+func svnStatus(vcsSvn *Cmd, rootDir string) (Status, error) {
+	out, err := vcsSvn.runOutputVerboseOnly(rootDir, "info --show-item last-changed-revision")
+	if err != nil {
+		return Status{}, err
+	}
+	rev := strings.TrimSpace(string(out))
+
+	out, err = vcsSvn.runOutputVerboseOnly(rootDir, "info --show-item last-changed-date")
+	if err != nil {
+		return Status{}, err
+	}
+	commitTime, err := time.Parse(time.RFC3339, strings.TrimSpace(string(out)))
+	if err != nil {
+		return Status{}, fmt.Errorf("unable to parse output of svn info: %v", err)
+	}
+
+	out, err = vcsSvn.runOutputVerboseOnly(rootDir, "status")
+	if err != nil {
+		return Status{}, err
+	}
+	uncommitted := len(out) > 0
+
+	return Status{
+		Revision:    rev,
+		CommitTime:  commitTime,
+		Uncommitted: uncommitted,
+	}, nil
+}
+
 // fossilRepoName is the name go get associates with a fossil repository. In the
 // real world the file can be named anything.
 const fossilRepoName = ".fossil"

src/cmd/go/testdata/script/version_buildvcs_svn.txt

@@ -0,0 +1,96 @@
+# This test checks that VCS information is stamped into Go binaries by default,
+# controlled with -buildvcs. This test focuses on Subversion specifics.
+# The Git test covers common functionality.
+
+[!exec:svn] skip
+[!exec:svnadmin] skip
+[short] skip
+env GOBIN=$WORK/gopath/bin
+env oldpath=$PATH
+cd repo/a
+
+# If there's no local repository, there's no VCS info.
+go install
+go version -m $GOBIN/a$GOEXE
+! stdout vcs.revision
+stdout '\s+mod\s+example.com/a\s+\(devel\)'
+rm $GOBIN/a$GOEXE
+
+# If there is a repository, but it can't be used for some reason,
+# there should be an error. It should hint about -buildvcs=false.
+cd ..
+mkdir .svn
+env PATH=$WORK${/}fakebin${:}$oldpath
+chmod 0755 $WORK/fakebin/svn
+! exec svn help
+cd a
+! go install
+stderr '^error obtaining VCS status: exit status 1\n\tUse -buildvcs=false to disable VCS stamping.$'
+rm $GOBIN/a$GOEXE
+cd ..
+env PATH=$oldpath
+rm .svn
+
+# Untagged repo.
+exec svnadmin create repo
+exec svn checkout file://$PWD/repo workingDir
+cd workingDir
+cp ../a/a.go .
+cp ../a/go.mod .
+cp ../README .
+exec svn status
+exec svn add a.go go.mod README
+exec svn commit -m 'initial commit'
+exec svn update
+go install
+go version -m $GOBIN/a$GOEXE
+stdout '^\tbuild\tvcs=svn$'
+stdout '^\tbuild\tvcs.revision=1$'
+stdout '^\tbuild\tvcs.time='
+stdout '^\tbuild\tvcs.modified=false$'
+stdout '^\tmod\texample.com/a\tv0.0.0-\d+-\d+\t+'
+rm $GOBIN/a$GOEXE
+
+# Building with -buildvcs=false suppresses the info.
+go install -buildvcs=false
+go version -m $GOBIN/a$GOEXE
+! stdout vcs.revision
+stdout '\s+mod\s+example.com/a\s+\(devel\)'
+rm $GOBIN/a$GOEXE
+
+# An untracked file is shown as uncommitted, even if it isn't part of the build.
+cp ../../outside/empty.txt extra.txt
+go install
+go version -m $GOBIN/a$GOEXE
+stdout '^\tbuild\tvcs.modified=true$'
+stdout '\s+mod\s+example.com/a\s+v0.0.0-\d+-\d+\+dirty\s+'
+rm extra.txt
+rm $GOBIN/a$GOEXE
+
+# An edited file is shown as uncommitted, even if it isn't part of the build.
+cp ../../outside/empty.txt README
+go install
+go version -m $GOBIN/a$GOEXE
+stdout '^\tbuild\tvcs.modified=true$'
+stdout '\s+mod\s+example.com/a\s+v0.0.0-\d+-\d+\+dirty\s+'
+exec svn revert README
+rm $GOBIN/a$GOEXE
+
+-- $WORK/fakebin/svn --
+#!/bin/sh
+exit 1
+-- $WORK/fakebin/svn.bat --
+exit 1
+-- repo/README --
+Far out in the uncharted backwaters of the unfashionable end of the western
+spiral arm of the Galaxy lies a small, unregarded yellow sun.
+-- repo/a/go.mod --
+module example.com/a
+
+go 1.18
+-- repo/a/a.go --
+package main
+
+func main() {}
+
+-- outside/empty.txt --