cmd/go: add Shell.RemoveAll

There are quite a few places that perform their own command logging
and then use os.RemoveAll. Unify (nearly) all of these into
(*Shell).RemoveAll, like many of the other internal implementations of
basic shell operations.

Change-Id: I94a2cbd9dc150a4c94a4051c42ce8e86dcc736fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/536099
Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Austin Clements <austin@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/go/internal/clean/clean.go

@@ -162,30 +162,16 @@ func runClean(ctx context.Context, cmd *base.Command, args []string) {
 			subdirs, _ := filepath.Glob(filepath.Join(str.QuoteGlob(dir), "[0-9a-f][0-9a-f]"))
 			printedErrors := false
 			if len(subdirs) > 0 {
-				if cfg.BuildN || cfg.BuildX {
-					sh.ShowCmd("", "rm -r %s", strings.Join(subdirs, " "))
-				}
-				if !cfg.BuildN {
-					for _, d := range subdirs {
-						// Only print the first error - there may be many.
-						// This also mimics what os.RemoveAll(dir) would do.
-						if err := os.RemoveAll(d); err != nil && !printedErrors {
-							printedErrors = true
-							base.Error(err)
-						}
-					}
+				if err := sh.RemoveAll(subdirs...); err != nil && !printedErrors {
+					printedErrors = true
+					base.Error(err)
 				}
 			}
 
 			logFile := filepath.Join(dir, "log.txt")
-			if cfg.BuildN || cfg.BuildX {
-				sh.ShowCmd("", "rm -f %s", logFile)
-			}
-			if !cfg.BuildN {
-				if err := os.RemoveAll(logFile); err != nil && !printedErrors {
-					printedErrors = true
-					base.Error(err)
-				}
+			if err := sh.RemoveAll(logFile); err != nil && !printedErrors {
+				printedErrors = true
+				base.Error(err)
 			}
 		}
 	}
@@ -236,13 +222,8 @@ func runClean(ctx context.Context, cmd *base.Command, args []string) {
 
 	if cleanFuzzcache {
 		fuzzDir := cache.Default().FuzzDir()
-		if cfg.BuildN || cfg.BuildX {
-			sh.ShowCmd("", "rm -rf %s", fuzzDir)
-		}
-		if !cfg.BuildN {
-			if err := os.RemoveAll(fuzzDir); err != nil {
-				base.Error(err)
-			}
+		if err := sh.RemoveAll(fuzzDir); err != nil {
+			base.Error(err)
 		}
 	}
 }
@@ -363,13 +344,7 @@ func clean(p *load.Package) {
 		if dir.IsDir() {
 			// TODO: Remove once Makefiles are forgotten.
 			if cleanDir[name] {
-				if cfg.BuildN || cfg.BuildX {
-					sh.ShowCmd(p.Dir, "rm -r %s", name)
-					if cfg.BuildN {
-						continue
-					}
-				}
-				if err := os.RemoveAll(filepath.Join(p.Dir, name)); err != nil {
+				if err := sh.RemoveAll(filepath.Join(p.Dir, name)); err != nil {
 					base.Error(err)
 				}
 			}

src/cmd/go/internal/test/test.go

@@ -2041,10 +2041,7 @@ func builderCleanTest(b *work.Builder, ctx context.Context, a *work.Action) erro
 	if cfg.BuildWork {
 		return nil
 	}
-	if cfg.BuildX {
-		b.Shell(a).ShowCmd("", "rm -r %s", a.Objdir)
-	}
-	os.RemoveAll(a.Objdir)
+	b.Shell(a).RemoveAll(a.Objdir)
 	return nil
 }
 

src/cmd/go/internal/work/exec.go

@@ -1858,17 +1858,43 @@ var AllowInstall = func(*Action) error { return nil }
 // this keeps the intermediate objects from hitting the disk.
 func (b *Builder) cleanup(a *Action) {
 	if !cfg.BuildWork {
-		if cfg.BuildX {
-			// Don't say we are removing the directory if
-			// we never created it.
-			if _, err := os.Stat(a.Objdir); err == nil || cfg.BuildN {
-				b.Shell(a).ShowCmd("", "rm -r %s", a.Objdir)
-			}
-		}
-		os.RemoveAll(a.Objdir)
+		b.Shell(a).RemoveAll(a.Objdir)
 	}
 }
 
+// RemoveAll is like 'rm -rf'. It attempts to remove all paths even if there's
+// an error, and returns the first error.
+func (sh *Shell) RemoveAll(paths ...string) error {
+	if cfg.BuildN || cfg.BuildX {
+		// Don't say we are removing the directory if we never created it.
+		show := func() bool {
+			for _, path := range paths {
+				if _, ok := sh.mkdirCache.Get(path); ok {
+					return true
+				}
+				if _, err := os.Stat(path); !os.IsNotExist(err) {
+					return true
+				}
+			}
+			return false
+		}
+		if show() {
+			sh.ShowCmd("", "rm -rf %s", strings.Join(paths, " "))
+		}
+	}
+	if cfg.BuildN {
+		return nil
+	}
+
+	var err error
+	for _, path := range paths {
+		if err2 := os.RemoveAll(path); err2 != nil && err == nil {
+			err = err2
+		}
+	}
+	return err
+}
+
 // moveOrCopyFile is like 'mv src dst' or 'cp src dst'.
 func (sh *Shell) moveOrCopyFile(dst, src string, perm fs.FileMode, force bool) error {
 	if cfg.BuildN {

src/cmd/go/internal/work/shell.go

@@ -15,8 +15,6 @@ import (
 //
 // Shell tracks context related to running commands, and form a tree much like
 // context.Context.
-//
-// TODO: Add a RemoveAll method. "rm -rf" is pretty common.
 type Shell struct {
 	action       *Action // nil for the root shell
 	*shellShared         // per-Builder state shared across Shells