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:build !unix
6
7package os
8
9import (
10	"io"
11	"runtime"
12	"syscall"
13)
14
15func removeAll(path string) error {
16	if path == "" {
17		// fail silently to retain compatibility with previous behavior
18		// of RemoveAll. See issue 28830.
19		return nil
20	}
21
22	// The rmdir system call permits removing "." on Plan 9,
23	// so we don't permit it to remain consistent with the
24	// "at" implementation of RemoveAll.
25	if endsWithDot(path) {
26		return &PathError{Op: "RemoveAll", Path: path, Err: syscall.EINVAL}
27	}
28
29	// Simple case: if Remove works, we're done.
30	err := Remove(path)
31	if err == nil || IsNotExist(err) {
32		return nil
33	}
34
35	// Otherwise, is this a directory we need to recurse into?
36	dir, serr := Lstat(path)
37	if serr != nil {
38		if serr, ok := serr.(*PathError); ok && (IsNotExist(serr.Err) || serr.Err == syscall.ENOTDIR) {
39			return nil
40		}
41		return serr
42	}
43	if !dir.IsDir() {
44		// Not a directory; return the error from Remove.
45		return err
46	}
47
48	// Remove contents & return first error.
49	err = nil
50	for {
51		fd, err := Open(path)
52		if err != nil {
53			if IsNotExist(err) {
54				// Already deleted by someone else.
55				return nil
56			}
57			return err
58		}
59
60		const reqSize = 1024
61		var names []string
62		var readErr error
63
64		for {
65			numErr := 0
66			names, readErr = fd.Readdirnames(reqSize)
67
68			for _, name := range names {
69				err1 := RemoveAll(path + string(PathSeparator) + name)
70				if err == nil {
71					err = err1
72				}
73				if err1 != nil {
74					numErr++
75				}
76			}
77
78			// If we can delete any entry, break to start new iteration.
79			// Otherwise, we discard current names, get next entries and try deleting them.
80			if numErr != reqSize {
81				break
82			}
83		}
84
85		// Removing files from the directory may have caused
86		// the OS to reshuffle it. Simply calling Readdirnames
87		// again may skip some entries. The only reliable way
88		// to avoid this is to close and re-open the
89		// directory. See issue 20841.
90		fd.Close()
91
92		if readErr == io.EOF {
93			break
94		}
95		// If Readdirnames returned an error, use it.
96		if err == nil {
97			err = readErr
98		}
99		if len(names) == 0 {
100			break
101		}
102
103		// We don't want to re-open unnecessarily, so if we
104		// got fewer than request names from Readdirnames, try
105		// simply removing the directory now. If that
106		// succeeds, we are done.
107		if len(names) < reqSize {
108			err1 := Remove(path)
109			if err1 == nil || IsNotExist(err1) {
110				return nil
111			}
112
113			if err != nil {
114				// We got some error removing the
115				// directory contents, and since we
116				// read fewer names than we requested
117				// there probably aren't more files to
118				// remove. Don't loop around to read
119				// the directory again. We'll probably
120				// just get the same error.
121				return err
122			}
123		}
124	}
125
126	// Remove directory.
127	err1 := Remove(path)
128	if err1 == nil || IsNotExist(err1) {
129		return nil
130	}
131	if runtime.GOOS == "windows" && IsPermission(err1) {
132		if fs, err := Stat(path); err == nil {
133			if err = Chmod(path, FileMode(0200|int(fs.Mode()))); err == nil {
134				err1 = Remove(path)
135			}
136		}
137	}
138	if err == nil {
139		err = err1
140	}
141	return err
142}
143