runtime: abort stack scan in cases that we cannot unwind the stack
[gcc.git] / libgo / go / os / file_posix.go
1 // Copyright 2009 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 // +build aix darwin dragonfly freebsd hurd js,wasm linux nacl netbsd openbsd solaris windows
6
7 package os
8
9 import (
10 "runtime"
11 "syscall"
12 "time"
13 )
14
15 func sigpipe() // implemented in package runtime
16
17 // Readlink returns the destination of the named symbolic link.
18 // If there is an error, it will be of type *PathError.
19 func Readlink(name string) (string, error) {
20 for len := 128; ; len *= 2 {
21 b := make([]byte, len)
22 n, e := fixCount(syscall.Readlink(fixLongPath(name), b))
23 // buffer too small
24 if runtime.GOOS == "aix" && e == syscall.ERANGE {
25 continue
26 }
27 if e != nil {
28 return "", &PathError{"readlink", name, e}
29 }
30 if n < len {
31 return string(b[0:n]), nil
32 }
33 }
34 }
35
36 // syscallMode returns the syscall-specific mode bits from Go's portable mode bits.
37 func syscallMode(i FileMode) (o uint32) {
38 o |= uint32(i.Perm())
39 if i&ModeSetuid != 0 {
40 o |= syscall.S_ISUID
41 }
42 if i&ModeSetgid != 0 {
43 o |= syscall.S_ISGID
44 }
45 if i&ModeSticky != 0 {
46 o |= syscall.S_ISVTX
47 }
48 // No mapping for Go's ModeTemporary (plan9 only).
49 return
50 }
51
52 // See docs in file.go:Chmod.
53 func chmod(name string, mode FileMode) error {
54 if e := syscall.Chmod(fixLongPath(name), syscallMode(mode)); e != nil {
55 return &PathError{"chmod", name, e}
56 }
57 return nil
58 }
59
60 // See docs in file.go:(*File).Chmod.
61 func (f *File) chmod(mode FileMode) error {
62 if err := f.checkValid("chmod"); err != nil {
63 return err
64 }
65 if e := f.pfd.Fchmod(syscallMode(mode)); e != nil {
66 return f.wrapErr("chmod", e)
67 }
68 return nil
69 }
70
71 // Chown changes the numeric uid and gid of the named file.
72 // If the file is a symbolic link, it changes the uid and gid of the link's target.
73 // A uid or gid of -1 means to not change that value.
74 // If there is an error, it will be of type *PathError.
75 //
76 // On Windows or Plan 9, Chown always returns the syscall.EWINDOWS or
77 // EPLAN9 error, wrapped in *PathError.
78 func Chown(name string, uid, gid int) error {
79 if e := syscall.Chown(name, uid, gid); e != nil {
80 return &PathError{"chown", name, e}
81 }
82 return nil
83 }
84
85 // Lchown changes the numeric uid and gid of the named file.
86 // If the file is a symbolic link, it changes the uid and gid of the link itself.
87 // If there is an error, it will be of type *PathError.
88 //
89 // On Windows, it always returns the syscall.EWINDOWS error, wrapped
90 // in *PathError.
91 func Lchown(name string, uid, gid int) error {
92 if e := syscall.Lchown(name, uid, gid); e != nil {
93 return &PathError{"lchown", name, e}
94 }
95 return nil
96 }
97
98 // Chown changes the numeric uid and gid of the named file.
99 // If there is an error, it will be of type *PathError.
100 //
101 // On Windows, it always returns the syscall.EWINDOWS error, wrapped
102 // in *PathError.
103 func (f *File) Chown(uid, gid int) error {
104 if err := f.checkValid("chown"); err != nil {
105 return err
106 }
107 if e := f.pfd.Fchown(uid, gid); e != nil {
108 return f.wrapErr("chown", e)
109 }
110 return nil
111 }
112
113 // Truncate changes the size of the file.
114 // It does not change the I/O offset.
115 // If there is an error, it will be of type *PathError.
116 func (f *File) Truncate(size int64) error {
117 if err := f.checkValid("truncate"); err != nil {
118 return err
119 }
120 if e := f.pfd.Ftruncate(size); e != nil {
121 return f.wrapErr("truncate", e)
122 }
123 return nil
124 }
125
126 // Sync commits the current contents of the file to stable storage.
127 // Typically, this means flushing the file system's in-memory copy
128 // of recently written data to disk.
129 func (f *File) Sync() error {
130 if err := f.checkValid("sync"); err != nil {
131 return err
132 }
133 if e := f.pfd.Fsync(); e != nil {
134 return f.wrapErr("sync", e)
135 }
136 return nil
137 }
138
139 // Chtimes changes the access and modification times of the named
140 // file, similar to the Unix utime() or utimes() functions.
141 //
142 // The underlying filesystem may truncate or round the values to a
143 // less precise time unit.
144 // If there is an error, it will be of type *PathError.
145 func Chtimes(name string, atime time.Time, mtime time.Time) error {
146 var utimes [2]syscall.Timespec
147 utimes[0] = syscall.NsecToTimespec(atime.UnixNano())
148 utimes[1] = syscall.NsecToTimespec(mtime.UnixNano())
149 if e := syscall.UtimesNano(fixLongPath(name), utimes[0:]); e != nil {
150 return &PathError{"chtimes", name, e}
151 }
152 return nil
153 }
154
155 // Chdir changes the current working directory to the file,
156 // which must be a directory.
157 // If there is an error, it will be of type *PathError.
158 func (f *File) Chdir() error {
159 if err := f.checkValid("chdir"); err != nil {
160 return err
161 }
162 if e := f.pfd.Fchdir(); e != nil {
163 return f.wrapErr("chdir", e)
164 }
165 return nil
166 }
167
168 // setDeadline sets the read and write deadline.
169 func (f *File) setDeadline(t time.Time) error {
170 if err := f.checkValid("SetDeadline"); err != nil {
171 return err
172 }
173 return f.pfd.SetDeadline(t)
174 }
175
176 // setReadDeadline sets the read deadline.
177 func (f *File) setReadDeadline(t time.Time) error {
178 if err := f.checkValid("SetReadDeadline"); err != nil {
179 return err
180 }
181 return f.pfd.SetReadDeadline(t)
182 }
183
184 // setWriteDeadline sets the write deadline.
185 func (f *File) setWriteDeadline(t time.Time) error {
186 if err := f.checkValid("SetWriteDeadline"); err != nil {
187 return err
188 }
189 return f.pfd.SetWriteDeadline(t)
190 }
191
192 // checkValid checks whether f is valid for use.
193 // If not, it returns an appropriate error, perhaps incorporating the operation name op.
194 func (f *File) checkValid(op string) error {
195 if f == nil {
196 return ErrInvalid
197 }
198 return nil
199 }