cmd/dist: add a test in misc/reboot to verify that the toolchain can self-bootstrap

Fixes #30758

Change-Id: I8e49958602de9caa47bb5710828158e51744f375
Reviewed-on: https://go-review.googlesource.com/c/go/+/167478
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/misc/reboot/overlaydir_test.go b/misc/reboot/overlaydir_test.go
new file mode 100644 (file)
index 0000000..b38a8ef
--- /dev/null
+++ b/misc/reboot/overlaydir_test.go
@@ -0,0 +1,80 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package reboot_test
+
+import (
+       "io"
+       "os"
+       "path/filepath"
+       "strings"
+)
+
+// overlayDir makes a minimal-overhead copy of srcRoot in which new files may be added.
+//
+// TODO: Once we no longer need to support the misc module in GOPATH mode,
+// factor this function out into a package to reduce duplication.
+func overlayDir(dstRoot, srcRoot string) error {
+       dstRoot = filepath.Clean(dstRoot)
+       if err := os.MkdirAll(dstRoot, 0777); err != nil {
+               return err
+       }
+
+       // If we don't use the absolute path here, exec'ing make.bash fails with
+       // “too many levels of symbolic links”.
+       symBase, err := filepath.Abs(srcRoot)
+       if err != nil {
+               return err
+       }
+
+       return filepath.Walk(srcRoot, func(srcPath string, info os.FileInfo, err error) error {
+               if err != nil || srcPath == srcRoot {
+                       return err
+               }
+
+               suffix := strings.TrimPrefix(srcPath, srcRoot)
+               for len(suffix) > 0 && suffix[0] == filepath.Separator {
+                       suffix = suffix[1:]
+               }
+               dstPath := filepath.Join(dstRoot, suffix)
+
+               perm := info.Mode() & os.ModePerm
+               if info.Mode()&os.ModeSymlink != 0 {
+                       info, err = os.Stat(srcPath)
+                       if err != nil {
+                               return err
+                       }
+                       perm = info.Mode() & os.ModePerm
+               }
+
+               // Always copy directories (don't symlink them).
+               // If we add a file in the overlay, we don't want to add it in the original.
+               if info.IsDir() {
+                       return os.Mkdir(dstPath, perm)
+               }
+
+               // If the OS supports symlinks, use them instead of copying bytes.
+               if err := os.Symlink(filepath.Join(symBase, suffix), dstPath); err == nil {
+                       return nil
+               }
+
+               // Otherwise, copy the bytes.
+               src, err := os.Open(srcPath)
+               if err != nil {
+                       return err
+               }
+               defer src.Close()
+
+               dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
+               if err != nil {
+                       return err
+               }
+
+               _, err = io.Copy(dst, src)
+               if closeErr := dst.Close(); err == nil {
+                       err = closeErr
+               }
+               return err
+       })
+}

diff --git a/misc/reboot/reboot_test.go b/misc/reboot/reboot_test.go
new file mode 100644 (file)
index 0000000..717c0fb
--- /dev/null
+++ b/misc/reboot/reboot_test.go
@@ -0,0 +1,52 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package reboot_test verifies that the current GOROOT can be used to bootstrap
+// itself.
+package reboot_test
+
+import (
+       "io/ioutil"
+       "os"
+       "os/exec"
+       "path/filepath"
+       "runtime"
+       "testing"
+)
+
+func TestRepeatBootstrap(t *testing.T) {
+       goroot, err := ioutil.TempDir("", "reboot-goroot")
+       if err != nil {
+               t.Fatal(err)
+       }
+       defer os.RemoveAll(goroot)
+
+       gorootSrc := filepath.Join(goroot, "src")
+       if err := overlayDir(gorootSrc, filepath.Join(runtime.GOROOT(), "src")); err != nil {
+               t.Fatal(err)
+       }
+
+       if err := ioutil.WriteFile(filepath.Join(goroot, "VERSION"), []byte(runtime.Version()), 0666); err != nil {
+               t.Fatal(err)
+       }
+
+       var makeScript string
+       switch runtime.GOOS {
+       case "windows":
+               makeScript = "make.bat"
+       case "plan9":
+               makeScript = "make.rc"
+       default:
+               makeScript = "make.bash"
+       }
+
+       cmd := exec.Command(filepath.Join(runtime.GOROOT(), "src", makeScript))
+       cmd.Dir = gorootSrc
+       cmd.Env = append(os.Environ(), "GOROOT=", "GOROOT_BOOTSTRAP="+runtime.GOROOT())
+       cmd.Stderr = os.Stderr
+       cmd.Stdout = os.Stdout
+       if err := cmd.Run(); err != nil {
+               t.Fatal(err)
+       }
+}

diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index 1a54752f35c82d3db465d774a004a49130ddef6f..9e7205f56e85e73bf42a24a67ed4d783553b6545 100644 (file)
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -739,6 +739,12 @@ func (t *tester) registerTests() {
                        },
                })
        }
+
+       // Ensure that the toolchain can bootstrap itself.
+       // This test adds another ~45s to all.bash if run sequentially, so run it only on the builders.
+       if os.Getenv("GO_BUILDER_NAME") != "" && goos != "android" && !t.iOS() {
+               t.registerHostTest("reboot", "../misc/reboot", "misc/reboot", ".")
+       }
 }
 
 // isRegisteredTestName reports whether a test named testName has already