Commit 6aa3570cb0
Changed files (4)
lib
std
lib/std/fs/Dir.zig
@@ -1354,8 +1354,14 @@ pub fn readLink(self: Dir, sub_path: []const u8, buffer: []u8) ReadLinkError![]u
return self.readLinkWasi(sub_path, buffer);
}
if (native_os == .windows) {
- const sub_path_w = try windows.sliceToPrefixedFileW(self.fd, sub_path);
- return self.readLinkW(sub_path_w.span(), buffer);
+ var sub_path_w = try windows.sliceToPrefixedFileW(self.fd, sub_path);
+ const result_w = try self.readLinkW(sub_path_w.span(), &sub_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(buffer, result_w);
+ return buffer[0..end_index];
}
const sub_path_c = try posix.toPosixPath(sub_path);
return self.readLinkZ(&sub_path_c, buffer);
@@ -1369,15 +1375,24 @@ pub fn readLinkWasi(self: Dir, sub_path: []const u8, buffer: []u8) ![]u8 {
/// Same as `readLink`, except the `sub_path_c` parameter is null-terminated.
pub fn readLinkZ(self: Dir, sub_path_c: [*:0]const u8, buffer: []u8) ![]u8 {
if (native_os == .windows) {
- const sub_path_w = try windows.cStrToPrefixedFileW(self.fd, sub_path_c);
- return self.readLinkW(sub_path_w.span(), buffer);
+ var sub_path_w = try windows.cStrToPrefixedFileW(self.fd, sub_path_c);
+ const result_w = try self.readLinkW(sub_path_w.span(), &sub_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(buffer, result_w);
+ return buffer[0..end_index];
}
return posix.readlinkatZ(self.fd, sub_path_c, buffer);
}
-/// Windows-only. Same as `readLink` except the pathname parameter
-/// is WTF16 LE encoded.
-pub fn readLinkW(self: Dir, sub_path_w: []const u16, buffer: []u8) ![]u8 {
+/// Windows-only. Same as `readLink` except the path parameter
+/// is WTF-16 LE encoded, NT-prefixed.
+///
+/// `sub_path_w` will never be accessed after `buffer` has been written to, so it
+/// is safe to reuse a single buffer for both.
+pub fn readLinkW(self: Dir, sub_path_w: []const u16, buffer: []u16) ![]u16 {
return windows.ReadLink(self.fd, sub_path_w, buffer);
}
lib/std/fs/test.zig
@@ -193,10 +193,16 @@ test "Dir.readLink" {
// test 1: symlink to a file
try setupSymlink(ctx.dir, file_target_path, "symlink1", .{});
try testReadLink(ctx.dir, canonical_file_target_path, "symlink1");
+ if (builtin.os.tag == .windows) {
+ try testReadLinkW(testing.allocator, ctx.dir, canonical_file_target_path, "symlink1");
+ }
// test 2: symlink to a directory (can be different on Windows)
try setupSymlink(ctx.dir, dir_target_path, "symlink2", .{ .is_directory = true });
try testReadLink(ctx.dir, canonical_dir_target_path, "symlink2");
+ if (builtin.os.tag == .windows) {
+ try testReadLinkW(testing.allocator, ctx.dir, canonical_dir_target_path, "symlink2");
+ }
// test 3: relative path symlink
const parent_file = ".." ++ fs.path.sep_str ++ "target.txt";
@@ -205,6 +211,9 @@ test "Dir.readLink" {
defer subdir.close();
try setupSymlink(subdir, canonical_parent_file, "relative-link.txt", .{});
try testReadLink(subdir, canonical_parent_file, "relative-link.txt");
+ if (builtin.os.tag == .windows) {
+ try testReadLinkW(testing.allocator, subdir, canonical_parent_file, "relative-link.txt");
+ }
}
}.impl);
}
@@ -215,6 +224,17 @@ fn testReadLink(dir: Dir, target_path: []const u8, symlink_path: []const u8) !vo
try testing.expectEqualStrings(target_path, actual);
}
+fn testReadLinkW(allocator: mem.Allocator, dir: Dir, target_path: []const u8, symlink_path: []const u8) !void {
+ const target_path_w = try std.unicode.wtf8ToWtf16LeAlloc(allocator, target_path);
+ defer allocator.free(target_path_w);
+ // Calling the W functions directly requires the path to be NT-prefixed
+ const symlink_path_w = try std.os.windows.sliceToPrefixedFileW(dir.fd, symlink_path);
+ const wtf16_buffer = try allocator.alloc(u16, target_path_w.len);
+ defer allocator.free(wtf16_buffer);
+ const actual = try dir.readLinkW(symlink_path_w.span(), wtf16_buffer);
+ try testing.expectEqualSlices(u16, target_path_w, actual);
+}
+
fn testReadLinkAbsolute(target_path: []const u8, symlink_path: []const u8) !void {
var buffer: [fs.max_path_bytes]u8 = undefined;
const given = try fs.readLinkAbsolute(symlink_path, buffer[0..]);
lib/std/os/windows.zig
@@ -894,7 +894,9 @@ pub const ReadLinkError = error{
UnsupportedReparsePointType,
};
-pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u8) ReadLinkError![]u8 {
+/// `sub_path_w` will never be accessed after `out_buffer` has been written to, so it
+/// is safe to reuse a single buffer for both.
+pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u16) ReadLinkError![]u16 {
const result_handle = OpenFile(sub_path_w, .{
.access_mask = FILE_READ_ATTRIBUTES | SYNCHRONIZE,
.dir = dir,
@@ -926,14 +928,14 @@ pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u8) ReadLin
const len = buf.SubstituteNameLength >> 1;
const path_buf = @as([*]const u16, &buf.PathBuffer);
const is_relative = buf.Flags & SYMLINK_FLAG_RELATIVE != 0;
- return parseReadlinkPath(path_buf[offset..][0..len], is_relative, out_buffer);
+ return parseReadLinkPath(path_buf[offset..][0..len], is_relative, out_buffer);
},
IO_REPARSE_TAG_MOUNT_POINT => {
const buf: *const MOUNT_POINT_REPARSE_BUFFER = @ptrCast(@alignCast(&reparse_struct.DataBuffer[0]));
const offset = buf.SubstituteNameOffset >> 1;
const len = buf.SubstituteNameLength >> 1;
const path_buf = @as([*]const u16, &buf.PathBuffer);
- return parseReadlinkPath(path_buf[offset..][0..len], false, out_buffer);
+ return parseReadLinkPath(path_buf[offset..][0..len], false, out_buffer);
},
else => {
return error.UnsupportedReparsePointType;
@@ -941,19 +943,18 @@ pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u8) ReadLin
}
}
-/// Asserts that there is enough space is `out_buffer`.
-/// The result is encoded as [WTF-8](https://wtf-8.codeberg.page/).
-fn parseReadlinkPath(path: []const u16, is_relative: bool, out_buffer: []u8) []u8 {
- const win32_namespace_path = path: {
- if (is_relative) break :path path;
- const win32_path = ntToWin32Namespace(path) catch |err| switch (err) {
- error.NameTooLong => unreachable,
- error.NotNtPath => break :path path,
+fn parseReadLinkPath(path: []const u16, is_relative: bool, out_buffer: []u16) error{NameTooLong}![]u16 {
+ path: {
+ if (is_relative) break :path;
+ return ntToWin32Namespace(path, out_buffer) catch |err| switch (err) {
+ error.NameTooLong => |e| return e,
+ error.NotNtPath => break :path,
};
- break :path win32_path.span();
- };
- const out_len = std.unicode.wtf16LeToWtf8(out_buffer, win32_namespace_path);
- return out_buffer[0..out_len];
+ }
+ if (out_buffer.len < path.len) return error.NameTooLong;
+ const dest = out_buffer[0..path.len];
+ @memcpy(dest, path);
+ return dest;
}
pub const DeleteFileError = error{
@@ -2584,10 +2585,11 @@ test getUnprefixedPathType {
/// https://github.com/reactos/reactos/blob/master/modules/rostests/apitests/ntdll/RtlNtPathNameToDosPathName.c
///
/// `path` should be encoded as WTF-16LE.
-pub fn ntToWin32Namespace(path: []const u16) !PathSpace {
+///
+/// Supports in-place modification (`path` and `out` may refer to the same slice).
+pub fn ntToWin32Namespace(path: []const u16, out: []u16) error{ NameTooLong, NotNtPath }![]u16 {
if (path.len > PATH_MAX_WIDE) return error.NameTooLong;
- var path_space: PathSpace = undefined;
const namespace_prefix = getNamespacePrefix(u16, path);
switch (namespace_prefix) {
.nt => {
@@ -2595,23 +2597,19 @@ pub fn ntToWin32Namespace(path: []const u16) !PathSpace {
var after_prefix = path[4..]; // after the `\??\`
// The prefix \??\UNC\ means this is a UNC path, in which case the
// `\??\UNC\` should be replaced by `\\` (two backslashes)
- // TODO: the "UNC" should technically be matched case-insensitively, but
- // it's unlikely to matter since most/all paths passed into this
- // function will have come from the OS meaning it should have
- // the 'canonical' uppercase UNC.
const is_unc = after_prefix.len >= 4 and
- std.mem.eql(u16, after_prefix[0..3], std.unicode.utf8ToUtf16LeStringLiteral("UNC")) and
+ eqlIgnoreCaseWTF16(after_prefix[0..3], std.unicode.utf8ToUtf16LeStringLiteral("UNC")) and
std.fs.path.PathType.windows.isSep(u16, std.mem.littleToNative(u16, after_prefix[3]));
+ const win32_len = path.len - @as(usize, if (is_unc) 6 else 4);
+ if (out.len < win32_len) return error.NameTooLong;
if (is_unc) {
- path_space.data[0] = comptime std.mem.nativeToLittle(u16, '\\');
+ out[0] = comptime std.mem.nativeToLittle(u16, '\\');
dest_index += 1;
// We want to include the last `\` of `\??\UNC\`
after_prefix = path[7..];
}
- @memcpy(path_space.data[dest_index..][0..after_prefix.len], after_prefix);
- path_space.len = dest_index + after_prefix.len;
- path_space.data[path_space.len] = 0;
- return path_space;
+ @memmove(out[dest_index..][0..after_prefix.len], after_prefix);
+ return out[0..win32_len];
},
else => return error.NotNtPath,
}
@@ -2620,25 +2618,14 @@ pub fn ntToWin32Namespace(path: []const u16) !PathSpace {
test ntToWin32Namespace {
const L = std.unicode.utf8ToUtf16LeStringLiteral;
- try testNtToWin32Namespace(L("UNC"), L("\\??\\UNC"));
- try testNtToWin32Namespace(L("\\\\"), L("\\??\\UNC\\"));
- try testNtToWin32Namespace(L("\\\\path1"), L("\\??\\UNC\\path1"));
- try testNtToWin32Namespace(L("\\\\path1\\path2"), L("\\??\\UNC\\path1\\path2"));
+ var mutable_unc_path_buf = L("\\??\\UNC\\path1\\path2").*;
+ try std.testing.expectEqualSlices(u16, L("\\\\path1\\path2"), try ntToWin32Namespace(&mutable_unc_path_buf, &mutable_unc_path_buf));
- try testNtToWin32Namespace(L(""), L("\\??\\"));
- try testNtToWin32Namespace(L("C:"), L("\\??\\C:"));
- try testNtToWin32Namespace(L("C:\\"), L("\\??\\C:\\"));
- try testNtToWin32Namespace(L("C:\\test"), L("\\??\\C:\\test"));
- try testNtToWin32Namespace(L("C:\\test\\"), L("\\??\\C:\\test\\"));
-
- try std.testing.expectError(error.NotNtPath, ntToWin32Namespace(L("foo")));
- try std.testing.expectError(error.NotNtPath, ntToWin32Namespace(L("C:\\test")));
- try std.testing.expectError(error.NotNtPath, ntToWin32Namespace(L("\\\\.\\test")));
-}
+ var mutable_path_buf = L("\\??\\C:\\test\\").*;
+ try std.testing.expectEqualSlices(u16, L("C:\\test\\"), try ntToWin32Namespace(&mutable_path_buf, &mutable_path_buf));
-fn testNtToWin32Namespace(expected: []const u16, path: []const u16) !void {
- const converted = try ntToWin32Namespace(path);
- try std.testing.expectEqualSlices(u16, expected, converted.span());
+ var too_small_buf: [6]u16 = undefined;
+ try std.testing.expectError(error.NameTooLong, ntToWin32Namespace(L("\\??\\C:\\test"), &too_small_buf));
}
fn getFullPathNameW(path: [*:0]const u16, out: []u16) !usize {
lib/std/posix.zig
@@ -3021,26 +3021,42 @@ pub fn readlink(file_path: []const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (native_os == .wasi and !builtin.link_libc) {
return readlinkat(AT.FDCWD, file_path, out_buffer);
} else if (native_os == .windows) {
- const file_path_w = try windows.sliceToPrefixedFileW(null, file_path);
- return readlinkW(file_path_w.span(), out_buffer);
+ var file_path_w = try windows.sliceToPrefixedFileW(null, file_path);
+ const result_w = try readlinkW(file_path_w.span(), &file_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > out_buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(out_buffer, result_w);
+ return out_buffer[0..end_index];
} else {
const file_path_c = try toPosixPath(file_path);
return readlinkZ(&file_path_c, out_buffer);
}
}
-/// Windows-only. Same as `readlink` except `file_path` is WTF16 LE encoded.
-/// The result is encoded as [WTF-8](https://wtf-8.codeberg.page/).
+/// Windows-only. Same as `readlink` except `file_path` is WTF-16 LE encoded, NT-prefixed.
+/// The result is encoded as WTF-16 LE.
+///
+/// `file_path` will never be accessed after `out_buffer` has been written to, so it
+/// is safe to reuse a single buffer for both.
+///
/// See also `readlinkZ`.
-pub fn readlinkW(file_path: []const u16, out_buffer: []u8) ReadLinkError![]u8 {
+pub fn readlinkW(file_path: []const u16, out_buffer: []u16) ReadLinkError![]u16 {
return windows.ReadLink(fs.cwd().fd, file_path, out_buffer);
}
/// Same as `readlink` except `file_path` is null-terminated.
pub fn readlinkZ(file_path: [*:0]const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (native_os == .windows) {
- const file_path_w = try windows.cStrToPrefixedFileW(null, file_path);
- return readlinkW(file_path_w.span(), out_buffer);
+ var file_path_w = try windows.cStrToPrefixedFileW(null, file_path);
+ const result_w = try readlinkW(file_path_w.span(), &file_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > out_buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(out_buffer, result_w);
+ return out_buffer[0..end_index];
} else if (native_os == .wasi and !builtin.link_libc) {
return readlink(mem.sliceTo(file_path, 0), out_buffer);
}
@@ -3075,8 +3091,14 @@ pub fn readlinkat(dirfd: fd_t, file_path: []const u8, out_buffer: []u8) ReadLink
return readlinkatWasi(dirfd, file_path, out_buffer);
}
if (native_os == .windows) {
- const file_path_w = try windows.sliceToPrefixedFileW(dirfd, file_path);
- return readlinkatW(dirfd, file_path_w.span(), out_buffer);
+ var file_path_w = try windows.sliceToPrefixedFileW(dirfd, file_path);
+ const result_w = try readlinkatW(dirfd, file_path_w.span(), &file_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > out_buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(out_buffer, result_w);
+ return out_buffer[0..end_index];
}
const file_path_c = try toPosixPath(file_path);
return readlinkatZ(dirfd, &file_path_c, out_buffer);
@@ -3103,10 +3125,14 @@ pub fn readlinkatWasi(dirfd: fd_t, file_path: []const u8, out_buffer: []u8) Read
}
}
-/// Windows-only. Same as `readlinkat` except `file_path` is null-terminated, WTF16 LE encoded.
-/// The result is encoded as [WTF-8](https://wtf-8.codeberg.page/).
+/// Windows-only. Same as `readlinkat` except `file_path` WTF16 LE encoded, NT-prefixed.
+/// The result is encoded as WTF-16 LE.
+///
+/// `file_path` will never be accessed after `out_buffer` has been written to, so it
+/// is safe to reuse a single buffer for both.
+///
/// See also `readlinkat`.
-pub fn readlinkatW(dirfd: fd_t, file_path: []const u16, out_buffer: []u8) ReadLinkError![]u8 {
+pub fn readlinkatW(dirfd: fd_t, file_path: []const u16, out_buffer: []u16) ReadLinkError![]u16 {
return windows.ReadLink(dirfd, file_path, out_buffer);
}
@@ -3114,8 +3140,14 @@ pub fn readlinkatW(dirfd: fd_t, file_path: []const u16, out_buffer: []u8) ReadLi
/// See also `readlinkat`.
pub fn readlinkatZ(dirfd: fd_t, file_path: [*:0]const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (native_os == .windows) {
- const file_path_w = try windows.cStrToPrefixedFileW(dirfd, file_path);
- return readlinkatW(dirfd, file_path_w.span(), out_buffer);
+ var file_path_w = try windows.cStrToPrefixedFileW(dirfd, file_path);
+ const result_w = try readlinkatW(dirfd, file_path_w.span(), &file_path_w.data);
+
+ const len = std.unicode.calcWtf8Len(result_w);
+ if (len > out_buffer.len) return error.NameTooLong;
+
+ const end_index = std.unicode.wtf16LeToWtf8(out_buffer, result_w);
+ return out_buffer[0..end_index];
} else if (native_os == .wasi and !builtin.link_libc) {
return readlinkat(dirfd, mem.sliceTo(file_path, 0), out_buffer);
}