path/filepath, internal/filepathlite: move parts of filepath to filepathlite
The path/filepath package needs to depend on the os package to
implement Abs, Walk, and other functions. Move the implementation
of purely lexical functions from path/filepath into
internal/filepathlite, so they can be used by os and
other low-level packages.
Change-Id: Id211e547d6f1f58c82419695ff2d75cd6cd14a12
Reviewed-on: https://go-review.googlesource.com/c/go/+/566556
Reviewed-by: Behroz Karimpor <behrozkarimpor201@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/src/internal/filepathlite/path.go b/src/internal/filepathlite/path.go
index b452987..e3daa44 100644
--- a/src/internal/filepathlite/path.go
+++ b/src/internal/filepathlite/path.go
@@ -1,26 +1,274 @@
-// Copyright 2022 The Go Authors. All rights reserved.
+// Copyright 2024 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 filepathlite manipulates operating-system file paths.
+// Package filepathlite implements a subset of path/filepath,
+// only using packages which may be imported by "os".
+//
+// Tests for these functions are in path/filepath.
package filepathlite
import (
"errors"
+ "internal/stringslite"
"io/fs"
+ "slices"
)
var errInvalidPath = errors.New("invalid path")
+// A lazybuf is a lazily constructed path buffer.
+// It supports append, reading previously appended bytes,
+// and retrieving the final string. It does not allocate a buffer
+// to hold the output until that output diverges from s.
+type lazybuf struct {
+ path string
+ buf []byte
+ w int
+ volAndPath string
+ volLen int
+}
+
+func (b *lazybuf) index(i int) byte {
+ if b.buf != nil {
+ return b.buf[i]
+ }
+ return b.path[i]
+}
+
+func (b *lazybuf) append(c byte) {
+ if b.buf == nil {
+ if b.w < len(b.path) && b.path[b.w] == c {
+ b.w++
+ return
+ }
+ b.buf = make([]byte, len(b.path))
+ copy(b.buf, b.path[:b.w])
+ }
+ b.buf[b.w] = c
+ b.w++
+}
+
+func (b *lazybuf) prepend(prefix ...byte) {
+ b.buf = slices.Insert(b.buf, 0, prefix...)
+ b.w += len(prefix)
+}
+
+func (b *lazybuf) string() string {
+ if b.buf == nil {
+ return b.volAndPath[:b.volLen+b.w]
+ }
+ return b.volAndPath[:b.volLen] + string(b.buf[:b.w])
+}
+
+// Clean is filepath.Clean.
+func Clean(path string) string {
+ originalPath := path
+ volLen := volumeNameLen(path)
+ path = path[volLen:]
+ if path == "" {
+ if volLen > 1 && IsPathSeparator(originalPath[0]) && IsPathSeparator(originalPath[1]) {
+ // should be UNC
+ return FromSlash(originalPath)
+ }
+ return originalPath + "."
+ }
+ rooted := IsPathSeparator(path[0])
+
+ // Invariants:
+ // reading from path; r is index of next byte to process.
+ // writing to buf; w is index of next byte to write.
+ // dotdot is index in buf where .. must stop, either because
+ // it is the leading slash or it is a leading ../../.. prefix.
+ n := len(path)
+ out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen}
+ r, dotdot := 0, 0
+ if rooted {
+ out.append(Separator)
+ r, dotdot = 1, 1
+ }
+
+ for r < n {
+ switch {
+ case IsPathSeparator(path[r]):
+ // empty path element
+ r++
+ case path[r] == '.' && (r+1 == n || IsPathSeparator(path[r+1])):
+ // . element
+ r++
+ case path[r] == '.' && path[r+1] == '.' && (r+2 == n || IsPathSeparator(path[r+2])):
+ // .. element: remove to last separator
+ r += 2
+ switch {
+ case out.w > dotdot:
+ // can backtrack
+ out.w--
+ for out.w > dotdot && !IsPathSeparator(out.index(out.w)) {
+ out.w--
+ }
+ case !rooted:
+ // cannot backtrack, but not rooted, so append .. element.
+ if out.w > 0 {
+ out.append(Separator)
+ }
+ out.append('.')
+ out.append('.')
+ dotdot = out.w
+ }
+ default:
+ // real path element.
+ // add slash if needed
+ if rooted && out.w != 1 || !rooted && out.w != 0 {
+ out.append(Separator)
+ }
+ // copy element
+ for ; r < n && !IsPathSeparator(path[r]); r++ {
+ out.append(path[r])
+ }
+ }
+ }
+
+ // Turn empty string into "."
+ if out.w == 0 {
+ out.append('.')
+ }
+
+ postClean(&out) // avoid creating absolute paths on Windows
+ return FromSlash(out.string())
+}
+
+// IsLocal is filepath.IsLocal.
+func IsLocal(path string) bool {
+ return isLocal(path)
+}
+
+func unixIsLocal(path string) bool {
+ if IsAbs(path) || path == "" {
+ return false
+ }
+ hasDots := false
+ for p := path; p != ""; {
+ var part string
+ part, p, _ = stringslite.Cut(p, "/")
+ if part == "." || part == ".." {
+ hasDots = true
+ break
+ }
+ }
+ if hasDots {
+ path = Clean(path)
+ }
+ if path == ".." || stringslite.HasPrefix(path, "../") {
+ return false
+ }
+ return true
+}
+
// Localize is filepath.Localize.
-//
-// It is implemented in this package to avoid a dependency cycle
-// between os and file/filepath.
-//
-// Tests for this function are in path/filepath.
func Localize(path string) (string, error) {
if !fs.ValidPath(path) {
return "", errInvalidPath
}
return localize(path)
}
+
+// ToSlash is filepath.ToSlash.
+func ToSlash(path string) string {
+ if Separator == '/' {
+ return path
+ }
+ return replaceStringByte(path, Separator, '/')
+}
+
+// FromSlash is filepath.ToSlash.
+func FromSlash(path string) string {
+ if Separator == '/' {
+ return path
+ }
+ return replaceStringByte(path, '/', Separator)
+}
+
+func replaceStringByte(s string, old, new byte) string {
+ if stringslite.IndexByte(s, old) == -1 {
+ return s
+ }
+ n := []byte(s)
+ for i := range n {
+ if n[i] == old {
+ n[i] = new
+ }
+ }
+ return string(n)
+}
+
+// Split is filepath.Split.
+func Split(path string) (dir, file string) {
+ vol := VolumeName(path)
+ i := len(path) - 1
+ for i >= len(vol) && !IsPathSeparator(path[i]) {
+ i--
+ }
+ return path[:i+1], path[i+1:]
+}
+
+// Ext is filepath.Ext.
+func Ext(path string) string {
+ for i := len(path) - 1; i >= 0 && !IsPathSeparator(path[i]); i-- {
+ if path[i] == '.' {
+ return path[i:]
+ }
+ }
+ return ""
+}
+
+// Base is filepath.Base.
+func Base(path string) string {
+ if path == "" {
+ return "."
+ }
+ // Strip trailing slashes.
+ for len(path) > 0 && IsPathSeparator(path[len(path)-1]) {
+ path = path[0 : len(path)-1]
+ }
+ // Throw away volume name
+ path = path[len(VolumeName(path)):]
+ // Find the last element
+ i := len(path) - 1
+ for i >= 0 && !IsPathSeparator(path[i]) {
+ i--
+ }
+ if i >= 0 {
+ path = path[i+1:]
+ }
+ // If empty now, it had only slashes.
+ if path == "" {
+ return string(Separator)
+ }
+ return path
+}
+
+// Dir is filepath.Dir.
+func Dir(path string) string {
+ vol := VolumeName(path)
+ i := len(path) - 1
+ for i >= len(vol) && !IsPathSeparator(path[i]) {
+ i--
+ }
+ dir := Clean(path[len(vol) : i+1])
+ if dir == "." && len(vol) > 2 {
+ // must be UNC
+ return vol
+ }
+ return vol + dir
+}
+
+// VolumeName is filepath.VolumeName.
+func VolumeName(path string) string {
+ return FromSlash(path[:volumeNameLen(path)])
+}
+
+// VolumeNameLen returns the length of the leading volume name on Windows.
+// It returns 0 elsewhere.
+func VolumeNameLen(path string) int {
+ return volumeNameLen(path)
+}
diff --git a/src/path/filepath/path_nonwindows.go b/src/internal/filepathlite/path_nonwindows.go
similarity index 90%
rename from src/path/filepath/path_nonwindows.go
rename to src/internal/filepathlite/path_nonwindows.go
index db69f02..c9c4c02 100644
--- a/src/path/filepath/path_nonwindows.go
+++ b/src/internal/filepathlite/path_nonwindows.go
@@ -4,6 +4,6 @@
//go:build !windows
-package filepath
+package filepathlite
func postClean(out *lazybuf) {}
diff --git a/src/internal/filepathlite/path_plan9.go b/src/internal/filepathlite/path_plan9.go
index 91a95dd..5bbb724 100644
--- a/src/internal/filepathlite/path_plan9.go
+++ b/src/internal/filepathlite/path_plan9.go
@@ -1,10 +1,26 @@
-// Copyright 2023 The Go Authors. All rights reserved.
+// Copyright 2010 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 filepathlite
-import "internal/bytealg"
+import (
+ "internal/bytealg"
+ "internal/stringslite"
+)
+
+const (
+ Separator = '/' // OS-specific path separator
+ ListSeparator = '\000' // OS-specific path list separator
+)
+
+func IsPathSeparator(c uint8) bool {
+ return Separator == c
+}
+
+func isLocal(path string) bool {
+ return unixIsLocal(path)
+}
func localize(path string) (string, error) {
if path[0] == '#' || bytealg.IndexByteString(path, 0) >= 0 {
@@ -12,3 +28,14 @@
}
return path, nil
}
+
+// IsAbs reports whether the path is absolute.
+func IsAbs(path string) bool {
+ return stringslite.HasPrefix(path, "/") || stringslite.HasPrefix(path, "#")
+}
+
+// volumeNameLen returns length of the leading volume name on Windows.
+// It returns 0 elsewhere.
+func volumeNameLen(path string) int {
+ return 0
+}
diff --git a/src/internal/filepathlite/path_unix.go b/src/internal/filepathlite/path_unix.go
index edad208..e31f1ae 100644
--- a/src/internal/filepathlite/path_unix.go
+++ b/src/internal/filepathlite/path_unix.go
@@ -1,4 +1,4 @@
-// Copyright 2023 The Go Authors. All rights reserved.
+// Copyright 2010 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.
@@ -6,7 +6,23 @@
package filepathlite
-import "internal/bytealg"
+import (
+ "internal/bytealg"
+ "internal/stringslite"
+)
+
+const (
+ Separator = '/' // OS-specific path separator
+ ListSeparator = ':' // OS-specific path list separator
+)
+
+func IsPathSeparator(c uint8) bool {
+ return Separator == c
+}
+
+func isLocal(path string) bool {
+ return unixIsLocal(path)
+}
func localize(path string) (string, error) {
if bytealg.IndexByteString(path, 0) >= 0 {
@@ -14,3 +30,14 @@
}
return path, nil
}
+
+// IsAbs reports whether the path is absolute.
+func IsAbs(path string) bool {
+ return stringslite.HasPrefix(path, "/")
+}
+
+// volumeNameLen returns length of the leading volume name on Windows.
+// It returns 0 elsewhere.
+func volumeNameLen(path string) int {
+ return 0
+}
diff --git a/src/internal/filepathlite/path_windows.go b/src/internal/filepathlite/path_windows.go
index 3d7290b..8f34838 100644
--- a/src/internal/filepathlite/path_windows.go
+++ b/src/internal/filepathlite/path_windows.go
@@ -1,4 +1,4 @@
-// Copyright 2022 The Go Authors. All rights reserved.
+// Copyright 2010 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.
@@ -6,9 +6,52 @@
import (
"internal/bytealg"
+ "internal/stringslite"
"syscall"
)
+const (
+ Separator = '\\' // OS-specific path separator
+ ListSeparator = ';' // OS-specific path list separator
+)
+
+func IsPathSeparator(c uint8) bool {
+ return c == '\\' || c == '/'
+}
+
+func isLocal(path string) bool {
+ if path == "" {
+ return false
+ }
+ if IsPathSeparator(path[0]) {
+ // Path rooted in the current drive.
+ return false
+ }
+ if stringslite.IndexByte(path, ':') >= 0 {
+ // Colons are only valid when marking a drive letter ("C:foo").
+ // Rejecting any path with a colon is conservative but safe.
+ return false
+ }
+ hasDots := false // contains . or .. path elements
+ for p := path; p != ""; {
+ var part string
+ part, p, _ = cutPath(p)
+ if part == "." || part == ".." {
+ hasDots = true
+ }
+ if isReservedName(part) {
+ return false
+ }
+ }
+ if hasDots {
+ path = Clean(path)
+ }
+ if path == ".." || stringslite.HasPrefix(path, `..\`) {
+ return false
+ }
+ return true
+}
+
func localize(path string) (string, error) {
for i := 0; i < len(path); i++ {
switch path[i] {
@@ -29,7 +72,7 @@
element = p[:i]
p = p[i+1:]
}
- if IsReservedName(element) {
+ if isReservedName(element) {
return "", errInvalidPath
}
}
@@ -46,12 +89,12 @@
return path, nil
}
-// IsReservedName reports if name is a Windows reserved device name.
+// isReservedName reports if name is a Windows reserved device name.
// It does not detect names with an extension, which are also reserved on some Windows versions.
//
// For details, search for PRN in
// https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file.
-func IsReservedName(name string) bool {
+func isReservedName(name string) bool {
// Device names can have arbitrary trailing characters following a dot or colon.
base := name
for i := 0; i < len(base); i++ {
@@ -134,3 +177,153 @@
}
return c
}
+
+// IsAbs reports whether the path is absolute.
+func IsAbs(path string) (b bool) {
+ l := volumeNameLen(path)
+ if l == 0 {
+ return false
+ }
+ // If the volume name starts with a double slash, this is an absolute path.
+ if IsPathSeparator(path[0]) && IsPathSeparator(path[1]) {
+ return true
+ }
+ path = path[l:]
+ if path == "" {
+ return false
+ }
+ return IsPathSeparator(path[0])
+}
+
+// volumeNameLen returns length of the leading volume name on Windows.
+// It returns 0 elsewhere.
+//
+// See:
+// https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats
+// https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html
+func volumeNameLen(path string) int {
+ switch {
+ case len(path) >= 2 && path[1] == ':':
+ // Path starts with a drive letter.
+ //
+ // Not all Windows functions necessarily enforce the requirement that
+ // drive letters be in the set A-Z, and we don't try to here.
+ //
+ // We don't handle the case of a path starting with a non-ASCII character,
+ // in which case the "drive letter" might be multiple bytes long.
+ return 2
+
+ case len(path) == 0 || !IsPathSeparator(path[0]):
+ // Path does not have a volume component.
+ return 0
+
+ case pathHasPrefixFold(path, `\\.\UNC`):
+ // We're going to treat the UNC host and share as part of the volume
+ // prefix for historical reasons, but this isn't really principled;
+ // Windows's own GetFullPathName will happily remove the first
+ // component of the path in this space, converting
+ // \\.\unc\a\b\..\c into \\.\unc\a\c.
+ return uncLen(path, len(`\\.\UNC\`))
+
+ case pathHasPrefixFold(path, `\\.`) ||
+ pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`):
+ // Path starts with \\.\, and is a Local Device path; or
+ // path starts with \\?\ or \??\ and is a Root Local Device path.
+ //
+ // We treat the next component after the \\.\ prefix as
+ // part of the volume name, which means Clean(`\\?\c:\`)
+ // won't remove the trailing \. (See #64028.)
+ if len(path) == 3 {
+ return 3 // exactly \\.
+ }
+ _, rest, ok := cutPath(path[4:])
+ if !ok {
+ return len(path)
+ }
+ return len(path) - len(rest) - 1
+
+ case len(path) >= 2 && IsPathSeparator(path[1]):
+ // Path starts with \\, and is a UNC path.
+ return uncLen(path, 2)
+ }
+ return 0
+}
+
+// pathHasPrefixFold tests whether the path s begins with prefix,
+// ignoring case and treating all path separators as equivalent.
+// If s is longer than prefix, then s[len(prefix)] must be a path separator.
+func pathHasPrefixFold(s, prefix string) bool {
+ if len(s) < len(prefix) {
+ return false
+ }
+ for i := 0; i < len(prefix); i++ {
+ if IsPathSeparator(prefix[i]) {
+ if !IsPathSeparator(s[i]) {
+ return false
+ }
+ } else if toUpper(prefix[i]) != toUpper(s[i]) {
+ return false
+ }
+ }
+ if len(s) > len(prefix) && !IsPathSeparator(s[len(prefix)]) {
+ return false
+ }
+ return true
+}
+
+// uncLen returns the length of the volume prefix of a UNC path.
+// prefixLen is the prefix prior to the start of the UNC host;
+// for example, for "//host/share", the prefixLen is len("//")==2.
+func uncLen(path string, prefixLen int) int {
+ count := 0
+ for i := prefixLen; i < len(path); i++ {
+ if IsPathSeparator(path[i]) {
+ count++
+ if count == 2 {
+ return i
+ }
+ }
+ }
+ return len(path)
+}
+
+// cutPath slices path around the first path separator.
+func cutPath(path string) (before, after string, found bool) {
+ for i := range path {
+ if IsPathSeparator(path[i]) {
+ return path[:i], path[i+1:], true
+ }
+ }
+ return path, "", false
+}
+
+// isUNC reports whether path is a UNC path.
+func isUNC(path string) bool {
+ return len(path) > 1 && IsPathSeparator(path[0]) && IsPathSeparator(path[1])
+}
+
+// postClean adjusts the results of Clean to avoid turning a relative path
+// into an absolute or rooted one.
+func postClean(out *lazybuf) {
+ if out.volLen != 0 || out.buf == nil {
+ return
+ }
+ // If a ':' appears in the path element at the start of a path,
+ // insert a .\ at the beginning to avoid converting relative paths
+ // like a/../c: into c:.
+ for _, c := range out.buf {
+ if IsPathSeparator(c) {
+ break
+ }
+ if c == ':' {
+ out.prepend('.', Separator)
+ return
+ }
+ }
+ // If a path begins with \??\, insert a \. at the beginning
+ // to avoid converting paths like \a\..\??\c:\x into \??\c:\x
+ // (equivalent to c:\x).
+ if len(out.buf) >= 3 && IsPathSeparator(out.buf[0]) && out.buf[1] == '?' && out.buf[2] == '?' {
+ out.prepend(Separator, '.')
+ }
+}
diff --git a/src/path/filepath/match.go b/src/path/filepath/match.go
index 12f0bfa..6712479 100644
--- a/src/path/filepath/match.go
+++ b/src/path/filepath/match.go
@@ -6,6 +6,7 @@
import (
"errors"
+ "internal/filepathlite"
"os"
"runtime"
"sort"
@@ -307,7 +308,7 @@
// cleanGlobPathWindows is windows version of cleanGlobPath.
func cleanGlobPathWindows(path string) (prefixLen int, cleaned string) {
- vollen := volumeNameLen(path)
+ vollen := filepathlite.VolumeNameLen(path)
switch {
case path == "":
return 0, "."
diff --git a/src/path/filepath/path.go b/src/path/filepath/path.go
index cd70c2b..b0f3cbb 100644
--- a/src/path/filepath/path.go
+++ b/src/path/filepath/path.go
@@ -13,58 +13,13 @@
import (
"errors"
+ "internal/bytealg"
"internal/filepathlite"
"io/fs"
"os"
- "slices"
"sort"
- "strings"
)
-// A lazybuf is a lazily constructed path buffer.
-// It supports append, reading previously appended bytes,
-// and retrieving the final string. It does not allocate a buffer
-// to hold the output until that output diverges from s.
-type lazybuf struct {
- path string
- buf []byte
- w int
- volAndPath string
- volLen int
-}
-
-func (b *lazybuf) index(i int) byte {
- if b.buf != nil {
- return b.buf[i]
- }
- return b.path[i]
-}
-
-func (b *lazybuf) append(c byte) {
- if b.buf == nil {
- if b.w < len(b.path) && b.path[b.w] == c {
- b.w++
- return
- }
- b.buf = make([]byte, len(b.path))
- copy(b.buf, b.path[:b.w])
- }
- b.buf[b.w] = c
- b.w++
-}
-
-func (b *lazybuf) prepend(prefix ...byte) {
- b.buf = slices.Insert(b.buf, 0, prefix...)
- b.w += len(prefix)
-}
-
-func (b *lazybuf) string() string {
- if b.buf == nil {
- return b.volAndPath[:b.volLen+b.w]
- }
- return b.volAndPath[:b.volLen] + string(b.buf[:b.w])
-}
-
const (
Separator = os.PathSeparator
ListSeparator = os.PathListSeparator
@@ -98,78 +53,7 @@
// Getting Dot-Dot Right,”
// https://9p.io/sys/doc/lexnames.html
func Clean(path string) string {
- originalPath := path
- volLen := volumeNameLen(path)
- path = path[volLen:]
- if path == "" {
- if volLen > 1 && os.IsPathSeparator(originalPath[0]) && os.IsPathSeparator(originalPath[1]) {
- // should be UNC
- return FromSlash(originalPath)
- }
- return originalPath + "."
- }
- rooted := os.IsPathSeparator(path[0])
-
- // Invariants:
- // reading from path; r is index of next byte to process.
- // writing to buf; w is index of next byte to write.
- // dotdot is index in buf where .. must stop, either because
- // it is the leading slash or it is a leading ../../.. prefix.
- n := len(path)
- out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen}
- r, dotdot := 0, 0
- if rooted {
- out.append(Separator)
- r, dotdot = 1, 1
- }
-
- for r < n {
- switch {
- case os.IsPathSeparator(path[r]):
- // empty path element
- r++
- case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])):
- // . element
- r++
- case path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])):
- // .. element: remove to last separator
- r += 2
- switch {
- case out.w > dotdot:
- // can backtrack
- out.w--
- for out.w > dotdot && !os.IsPathSeparator(out.index(out.w)) {
- out.w--
- }
- case !rooted:
- // cannot backtrack, but not rooted, so append .. element.
- if out.w > 0 {
- out.append(Separator)
- }
- out.append('.')
- out.append('.')
- dotdot = out.w
- }
- default:
- // real path element.
- // add slash if needed
- if rooted && out.w != 1 || !rooted && out.w != 0 {
- out.append(Separator)
- }
- // copy element
- for ; r < n && !os.IsPathSeparator(path[r]); r++ {
- out.append(path[r])
- }
- }
- }
-
- // Turn empty string into "."
- if out.w == 0 {
- out.append('.')
- }
-
- postClean(&out) // avoid creating absolute paths on Windows
- return FromSlash(out.string())
+ return filepathlite.Clean(path)
}
// IsLocal reports whether path, using lexical analysis only, has all of these properties:
@@ -187,29 +71,7 @@
// In particular, it does not account for the effect of any symbolic links
// that may exist in the filesystem.
func IsLocal(path string) bool {
- return isLocal(path)
-}
-
-func unixIsLocal(path string) bool {
- if IsAbs(path) || path == "" {
- return false
- }
- hasDots := false
- for p := path; p != ""; {
- var part string
- part, p, _ = strings.Cut(p, "/")
- if part == "." || part == ".." {
- hasDots = true
- break
- }
- }
- if hasDots {
- path = Clean(path)
- }
- if path == ".." || strings.HasPrefix(path, "../") {
- return false
- }
- return true
+ return filepathlite.IsLocal(path)
}
// Localize converts a slash-separated path into an operating system path.
@@ -228,10 +90,7 @@
// in path with a slash ('/') character. Multiple separators are
// replaced by multiple slashes.
func ToSlash(path string) string {
- if Separator == '/' {
- return path
- }
- return strings.ReplaceAll(path, string(Separator), "/")
+ return filepathlite.ToSlash(path)
}
// FromSlash returns the result of replacing each slash ('/') character
@@ -241,10 +100,7 @@
// See also the Localize function, which converts a slash-separated path
// as used by the io/fs package to an operating system path.
func FromSlash(path string) string {
- if Separator == '/' {
- return path
- }
- return strings.ReplaceAll(path, "/", string(Separator))
+ return filepathlite.FromSlash(path)
}
// SplitList splits a list of paths joined by the OS-specific [ListSeparator],
@@ -261,12 +117,7 @@
// and file set to path.
// The returned values have the property that path = dir+file.
func Split(path string) (dir, file string) {
- vol := VolumeName(path)
- i := len(path) - 1
- for i >= len(vol) && !os.IsPathSeparator(path[i]) {
- i--
- }
- return path[:i+1], path[i+1:]
+ return filepathlite.Split(path)
}
// Join joins any number of path elements into a single path,
@@ -285,12 +136,7 @@
// in the final element of path; it is empty if there is
// no dot.
func Ext(path string) string {
- for i := len(path) - 1; i >= 0 && !os.IsPathSeparator(path[i]); i-- {
- if path[i] == '.' {
- return path[i:]
- }
- }
- return ""
+ return filepathlite.Ext(path)
}
// EvalSymlinks returns the path name after the evaluation of any symbolic
@@ -302,6 +148,11 @@
return evalSymlinks(path)
}
+// IsAbs reports whether the path is absolute.
+func IsAbs(path string) bool {
+ return filepathlite.IsAbs(path)
+}
+
// Abs returns an absolute representation of path.
// If the path is not absolute it will be joined with the current
// working directory to turn it into an absolute path. The absolute
@@ -342,7 +193,7 @@
targ = targ[len(targVol):]
if base == "." {
base = ""
- } else if base == "" && volumeNameLen(baseVol) > 2 /* isUNC */ {
+ } else if base == "" && filepathlite.VolumeNameLen(baseVol) > 2 /* isUNC */ {
// Treat any targetpath matching `\\host\share` basepath as absolute path.
base = string(Separator)
}
@@ -381,7 +232,7 @@
}
if b0 != bl {
// Base elements left. Must go up before going down.
- seps := strings.Count(base[b0:bl], string(Separator))
+ seps := bytealg.CountString(base[b0:bl], Separator)
size := 2 + seps*3
if tl != t0 {
size += 1 + tl - t0
@@ -602,28 +453,7 @@
// If the path is empty, Base returns ".".
// If the path consists entirely of separators, Base returns a single separator.
func Base(path string) string {
- if path == "" {
- return "."
- }
- // Strip trailing slashes.
- for len(path) > 0 && os.IsPathSeparator(path[len(path)-1]) {
- path = path[0 : len(path)-1]
- }
- // Throw away volume name
- path = path[len(VolumeName(path)):]
- // Find the last element
- i := len(path) - 1
- for i >= 0 && !os.IsPathSeparator(path[i]) {
- i--
- }
- if i >= 0 {
- path = path[i+1:]
- }
- // If empty now, it had only slashes.
- if path == "" {
- return string(Separator)
- }
- return path
+ return filepathlite.Base(path)
}
// Dir returns all but the last element of path, typically the path's directory.
@@ -633,17 +463,7 @@
// If the path consists entirely of separators, Dir returns a single separator.
// The returned path does not end in a separator unless it is the root directory.
func Dir(path string) string {
- vol := VolumeName(path)
- i := len(path) - 1
- for i >= len(vol) && !os.IsPathSeparator(path[i]) {
- i--
- }
- dir := Clean(path[len(vol) : i+1])
- if dir == "." && len(vol) > 2 {
- // must be UNC
- return vol
- }
- return vol + dir
+ return filepathlite.Dir(path)
}
// VolumeName returns leading volume name.
@@ -651,5 +471,5 @@
// Given "\\host\share\foo" it returns "\\host\share".
// On other platforms it returns "".
func VolumeName(path string) string {
- return FromSlash(path[:volumeNameLen(path)])
+ return filepathlite.VolumeName(path)
}
diff --git a/src/path/filepath/path_plan9.go b/src/path/filepath/path_plan9.go
index 453206a..0e5147b 100644
--- a/src/path/filepath/path_plan9.go
+++ b/src/path/filepath/path_plan9.go
@@ -4,22 +4,9 @@
package filepath
-import "strings"
-
-func isLocal(path string) bool {
- return unixIsLocal(path)
-}
-
-// IsAbs reports whether the path is absolute.
-func IsAbs(path string) bool {
- return strings.HasPrefix(path, "/") || strings.HasPrefix(path, "#")
-}
-
-// volumeNameLen returns length of the leading volume name on Windows.
-// It returns 0 elsewhere.
-func volumeNameLen(path string) int {
- return 0
-}
+import (
+ "strings"
+)
// HasPrefix exists for historical compatibility and should not be used.
//
diff --git a/src/path/filepath/path_unix.go b/src/path/filepath/path_unix.go
index 57e6217..6bc974d 100644
--- a/src/path/filepath/path_unix.go
+++ b/src/path/filepath/path_unix.go
@@ -6,22 +6,9 @@
package filepath
-import "strings"
-
-func isLocal(path string) bool {
- return unixIsLocal(path)
-}
-
-// IsAbs reports whether the path is absolute.
-func IsAbs(path string) bool {
- return strings.HasPrefix(path, "/")
-}
-
-// volumeNameLen returns length of the leading volume name on Windows.
-// It returns 0 elsewhere.
-func volumeNameLen(path string) int {
- return 0
-}
+import (
+ "strings"
+)
// HasPrefix exists for historical compatibility and should not be used.
//
diff --git a/src/path/filepath/path_windows.go b/src/path/filepath/path_windows.go
index 44037c4..d53f87f 100644
--- a/src/path/filepath/path_windows.go
+++ b/src/path/filepath/path_windows.go
@@ -1,179 +1,11 @@
-// Copyright 2010 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 filepath
import (
- "internal/filepathlite"
"os"
"strings"
"syscall"
)
-func isSlash(c uint8) bool {
- return c == '\\' || c == '/'
-}
-
-func toUpper(c byte) byte {
- if 'a' <= c && c <= 'z' {
- return c - ('a' - 'A')
- }
- return c
-}
-
-func isLocal(path string) bool {
- if path == "" {
- return false
- }
- if isSlash(path[0]) {
- // Path rooted in the current drive.
- return false
- }
- if strings.IndexByte(path, ':') >= 0 {
- // Colons are only valid when marking a drive letter ("C:foo").
- // Rejecting any path with a colon is conservative but safe.
- return false
- }
- hasDots := false // contains . or .. path elements
- for p := path; p != ""; {
- var part string
- part, p, _ = cutPath(p)
- if part == "." || part == ".." {
- hasDots = true
- }
- if filepathlite.IsReservedName(part) {
- return false
- }
- }
- if hasDots {
- path = Clean(path)
- }
- if path == ".." || strings.HasPrefix(path, `..\`) {
- return false
- }
- return true
-}
-
-// IsAbs reports whether the path is absolute.
-func IsAbs(path string) (b bool) {
- l := volumeNameLen(path)
- if l == 0 {
- return false
- }
- // If the volume name starts with a double slash, this is an absolute path.
- if isSlash(path[0]) && isSlash(path[1]) {
- return true
- }
- path = path[l:]
- if path == "" {
- return false
- }
- return isSlash(path[0])
-}
-
-// volumeNameLen returns length of the leading volume name on Windows.
-// It returns 0 elsewhere.
-//
-// See:
-// https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats
-// https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html
-func volumeNameLen(path string) int {
- switch {
- case len(path) >= 2 && path[1] == ':':
- // Path starts with a drive letter.
- //
- // Not all Windows functions necessarily enforce the requirement that
- // drive letters be in the set A-Z, and we don't try to here.
- //
- // We don't handle the case of a path starting with a non-ASCII character,
- // in which case the "drive letter" might be multiple bytes long.
- return 2
-
- case len(path) == 0 || !isSlash(path[0]):
- // Path does not have a volume component.
- return 0
-
- case pathHasPrefixFold(path, `\\.\UNC`):
- // We're going to treat the UNC host and share as part of the volume
- // prefix for historical reasons, but this isn't really principled;
- // Windows's own GetFullPathName will happily remove the first
- // component of the path in this space, converting
- // \\.\unc\a\b\..\c into \\.\unc\a\c.
- return uncLen(path, len(`\\.\UNC\`))
-
- case pathHasPrefixFold(path, `\\.`) ||
- pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`):
- // Path starts with \\.\, and is a Local Device path; or
- // path starts with \\?\ or \??\ and is a Root Local Device path.
- //
- // We treat the next component after the \\.\ prefix as
- // part of the volume name, which means Clean(`\\?\c:\`)
- // won't remove the trailing \. (See #64028.)
- if len(path) == 3 {
- return 3 // exactly \\.
- }
- _, rest, ok := cutPath(path[4:])
- if !ok {
- return len(path)
- }
- return len(path) - len(rest) - 1
-
- case len(path) >= 2 && isSlash(path[1]):
- // Path starts with \\, and is a UNC path.
- return uncLen(path, 2)
- }
- return 0
-}
-
-// pathHasPrefixFold tests whether the path s begins with prefix,
-// ignoring case and treating all path separators as equivalent.
-// If s is longer than prefix, then s[len(prefix)] must be a path separator.
-func pathHasPrefixFold(s, prefix string) bool {
- if len(s) < len(prefix) {
- return false
- }
- for i := 0; i < len(prefix); i++ {
- if isSlash(prefix[i]) {
- if !isSlash(s[i]) {
- return false
- }
- } else if toUpper(prefix[i]) != toUpper(s[i]) {
- return false
- }
- }
- if len(s) > len(prefix) && !isSlash(s[len(prefix)]) {
- return false
- }
- return true
-}
-
-// uncLen returns the length of the volume prefix of a UNC path.
-// prefixLen is the prefix prior to the start of the UNC host;
-// for example, for "//host/share", the prefixLen is len("//")==2.
-func uncLen(path string, prefixLen int) int {
- count := 0
- for i := prefixLen; i < len(path); i++ {
- if isSlash(path[i]) {
- count++
- if count == 2 {
- return i
- }
- }
- }
- return len(path)
-}
-
-// cutPath slices path around the first path separator.
-func cutPath(path string) (before, after string, found bool) {
- for i := range path {
- if isSlash(path[i]) {
- return path[:i], path[i+1:], true
- }
- }
- return path, "", false
-}
-
// HasPrefix exists for historical compatibility and should not be used.
//
// Deprecated: HasPrefix does not respect path boundaries and
@@ -237,7 +69,7 @@
switch {
case b.Len() == 0:
// Add the first non-empty path element unchanged.
- case isSlash(lastChar):
+ case os.IsPathSeparator(lastChar):
// If the path ends in a slash, strip any leading slashes from the next
// path element to avoid creating a UNC path (any path starting with "\\")
// from non-UNC elements.
@@ -245,13 +77,13 @@
// The correct behavior for Join when the first element is an incomplete UNC
// path (for example, "\\") is underspecified. We currently join subsequent
// elements so Join("\\", "host", "share") produces "\\host\share".
- for len(e) > 0 && isSlash(e[0]) {
+ for len(e) > 0 && os.IsPathSeparator(e[0]) {
e = e[1:]
}
// If the path is \ and the next path element is ??,
// add an extra .\ to create \.\?? rather than \??\
// (a Root Local Device path).
- if b.Len() == 1 && pathHasPrefixFold(e, "??") {
+ if b.Len() == 1 && strings.HasPrefix(e, "??") && (len(e) == len("??") || os.IsPathSeparator(e[2])) {
b.WriteString(`.\`)
}
case lastChar == ':':
@@ -280,29 +112,3 @@
func sameWord(a, b string) bool {
return strings.EqualFold(a, b)
}
-
-// postClean adjusts the results of Clean to avoid turning a relative path
-// into an absolute or rooted one.
-func postClean(out *lazybuf) {
- if out.volLen != 0 || out.buf == nil {
- return
- }
- // If a ':' appears in the path element at the start of a path,
- // insert a .\ at the beginning to avoid converting relative paths
- // like a/../c: into c:.
- for _, c := range out.buf {
- if os.IsPathSeparator(c) {
- break
- }
- if c == ':' {
- out.prepend('.', Separator)
- return
- }
- }
- // If a path begins with \??\, insert a \. at the beginning
- // to avoid converting paths like \a\..\??\c:\x into \??\c:\x
- // (equivalent to c:\x).
- if len(out.buf) >= 3 && os.IsPathSeparator(out.buf[0]) && out.buf[1] == '?' && out.buf[2] == '?' {
- out.prepend(Separator, '.')
- }
-}
diff --git a/src/path/filepath/symlink.go b/src/path/filepath/symlink.go
index f9435e0..a6047ae 100644
--- a/src/path/filepath/symlink.go
+++ b/src/path/filepath/symlink.go
@@ -6,6 +6,7 @@
import (
"errors"
+ "internal/filepathlite"
"io/fs"
"os"
"runtime"
@@ -13,7 +14,7 @@
)
func walkSymlinks(path string) (string, error) {
- volLen := volumeNameLen(path)
+ volLen := filepathlite.VolumeNameLen(path)
pathSeparator := string(os.PathSeparator)
if volLen < len(path) && os.IsPathSeparator(path[volLen]) {
@@ -34,7 +35,7 @@
// On Windows, "." can be a symlink.
// We look it up, and use the value if it is absolute.
// If not, we just return ".".
- isWindowsDot := runtime.GOOS == "windows" && path[volumeNameLen(path):] == "."
+ isWindowsDot := runtime.GOOS == "windows" && path[filepathlite.VolumeNameLen(path):] == "."
// The next path component is in path[start:end].
if end == start {
@@ -73,7 +74,7 @@
// Ordinary path component. Add it to result.
- if len(dest) > volumeNameLen(dest) && !os.IsPathSeparator(dest[len(dest)-1]) {
+ if len(dest) > filepathlite.VolumeNameLen(dest) && !os.IsPathSeparator(dest[len(dest)-1]) {
dest += pathSeparator
}
@@ -113,7 +114,7 @@
path = link + path[end:]
- v := volumeNameLen(link)
+ v := filepathlite.VolumeNameLen(link)
if v > 0 {
// Symlink to drive name is an absolute path.
if v < len(link) && os.IsPathSeparator(link[v]) {
