mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-21 08:45:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #18326 from squeek502/stat-symlink

Browse Source 
`File.stat`: Support detection of `Kind.sym_link` on Windows
This commit is contained in:
Veikka Tuominen 2023-12-22 12:06:10 +02:00 committed by GitHub
commit d787b78d2c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 123 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
lib/std/fs/File.zig
View File

@ -391,7 +391,26 @@ pub fn stat(self: File) StatError!Stat {
.inode = info.InternalInformation.IndexNumber,
.size = @as(u64, @bitCast(info.StandardInformation.EndOfFile)),
.mode = 0,
.kind = if (info.StandardInformation.Directory == 0) .file else .directory,
.kind = if (info.BasicInformation.FileAttributes & windows.FILE_ATTRIBUTE_REPARSE_POINT != 0) reparse_point: {
var tag_info: windows.FILE_ATTRIBUTE_TAG_INFO = undefined;
const tag_rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &tag_info, @sizeOf(windows.FILE_ATTRIBUTE_TAG_INFO), .FileAttributeTagInformation);
switch (tag_rc) {
.SUCCESS => {},
// INFO_LENGTH_MISMATCH and ACCESS_DENIED are the only documented possible errors
// https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/d295752f-ce89-4b98-8553-266d37c84f0e
.INFO_LENGTH_MISMATCH => unreachable,
.ACCESS_DENIED => return error.AccessDenied,
else => return windows.unexpectedStatus(rc),
}
if (tag_info.ReparseTag & windows.reparse_tag_name_surrogate_bit != 0) {
break :reparse_point .sym_link;
}
// Unknown reparse point
break :reparse_point .unknown;
} else if (info.BasicInformation.FileAttributes & windows.FILE_ATTRIBUTE_DIRECTORY != 0)
.directory
else
.file,
.atime = windows.fromSysTime(info.BasicInformation.LastAccessTime),
.mtime = windows.fromSysTime(info.BasicInformation.LastWriteTime),
.ctime = windows.fromSysTime(info.BasicInformation.ChangeTime),
@ -793,7 +812,7 @@ pub const MetadataWindows = struct {
/// Can only return: `.file`, `.directory`, `.sym_link` or `.unknown`
pub fn kind(self: Self) Kind {
if (self.attributes & windows.FILE_ATTRIBUTE_REPARSE_POINT != 0) {
if (self.reparse_tag & 0x20000000 != 0) {
if (self.reparse_tag & windows.reparse_tag_name_surrogate_bit != 0) {
return .sym_link;
}
} else if (self.attributes & windows.FILE_ATTRIBUTE_DIRECTORY != 0) {
@ -844,10 +863,17 @@ pub fn metadata(self: File) MetadataError!Metadata {
const reparse_tag: windows.DWORD = reparse_blk: {
if (info.BasicInformation.FileAttributes & windows.FILE_ATTRIBUTE_REPARSE_POINT != 0) {
var reparse_buf: [windows.MAXIMUM_REPARSE_DATA_BUFFER_SIZE]u8 = undefined;
try windows.DeviceIoControl(self.handle, windows.FSCTL_GET_REPARSE_POINT, null, reparse_buf[0..]);
const reparse_struct: *const windows.REPARSE_DATA_BUFFER = @ptrCast(@alignCast(&reparse_buf[0]));
break :reparse_blk reparse_struct.ReparseTag;
var tag_info: windows.FILE_ATTRIBUTE_TAG_INFO = undefined;
const tag_rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &tag_info, @sizeOf(windows.FILE_ATTRIBUTE_TAG_INFO), .FileAttributeTagInformation);
switch (tag_rc) {
.SUCCESS => {},
// INFO_LENGTH_MISMATCH and ACCESS_DENIED are the only documented possible errors
// https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/d295752f-ce89-4b98-8553-266d37c84f0e
.INFO_LENGTH_MISMATCH => unreachable,
.ACCESS_DENIED => return error.AccessDenied,
else => return windows.unexpectedStatus(rc),
}
break :reparse_blk tag_info.ReparseTag;
}
break :reparse_blk 0;
};

82
lib/std/fs/test.zig
View File

@ -156,6 +156,88 @@ fn testReadLink(dir: Dir, target_path: []const u8, symlink_path: []const u8) !vo
try testing.expectEqualStrings(target_path, given);
}
test "File.stat on a File that is a symlink returns Kind.sym_link" {
// This test requires getting a file descriptor of a symlink which
// is not possible on all targets
switch (builtin.target.os.tag) {
.windows, .linux => {},
else => return error.SkipZigTest,
}
try testWithAllSupportedPathTypes(struct {
fn impl(ctx: *TestContext) !void {
const dir_target_path = try ctx.transformPath("subdir");
try ctx.dir.makeDir(dir_target_path);
ctx.dir.symLink(dir_target_path, "symlink", .{ .is_directory = true }) catch |err| switch (err) {
// Symlink requires admin privileges on windows, so this test can legitimately fail.
error.AccessDenied => return error.SkipZigTest,
else => return err,
};
var symlink = switch (builtin.target.os.tag) {
.windows => windows_symlink: {
const w = std.os.windows;
const sub_path_w = try std.os.windows.cStrToPrefixedFileW(ctx.dir.fd, "symlink");
var result = Dir{
.fd = undefined,
};
const path_len_bytes = @as(u16, @intCast(sub_path_w.span().len * 2));
var nt_name = w.UNICODE_STRING{
.Length = path_len_bytes,
.MaximumLength = path_len_bytes,
.Buffer = @constCast(&sub_path_w.data),
};
var attr = w.OBJECT_ATTRIBUTES{
.Length = @sizeOf(w.OBJECT_ATTRIBUTES),
.RootDirectory = if (fs.path.isAbsoluteWindowsW(sub_path_w.span())) null else ctx.dir.fd,
.Attributes = 0,
.ObjectName = &nt_name,
.SecurityDescriptor = null,
.SecurityQualityOfService = null,
};
var io: w.IO_STATUS_BLOCK = undefined;
const rc = w.ntdll.NtCreateFile(
&result.fd,
w.STANDARD_RIGHTS_READ | w.FILE_READ_ATTRIBUTES | w.FILE_READ_EA | w.SYNCHRONIZE | w.FILE_TRAVERSE,
&attr,
&io,
null,
w.FILE_ATTRIBUTE_NORMAL,
w.FILE_SHARE_READ | w.FILE_SHARE_WRITE,
w.FILE_OPEN,
// FILE_OPEN_REPARSE_POINT is the important thing here
w.FILE_OPEN_REPARSE_POINT | w.FILE_DIRECTORY_FILE | w.FILE_SYNCHRONOUS_IO_NONALERT | w.FILE_OPEN_FOR_BACKUP_INTENT,
null,
0,
);
switch (rc) {
.SUCCESS => break :windows_symlink result,
else => return w.unexpectedStatus(rc),
}
},
.linux => linux_symlink: {
const sub_path_c = try os.toPosixPath("symlink");
// the O_NOFOLLOW | O_PATH combination can obtain a fd to a symlink
// note that if O_DIRECTORY is set, then this will error with ENOTDIR
const flags = os.O.NOFOLLOW | os.O.PATH | os.O.RDONLY | os.O.CLOEXEC;
const fd = try os.openatZ(ctx.dir.fd, &sub_path_c, flags, 0);
break :linux_symlink Dir{ .fd = fd };
},
else => unreachable,
};
defer symlink.close();
const stat = try symlink.stat();
try testing.expectEqual(File.Kind.sym_link, stat.kind);
}
}.impl);
}
test "relative symlink to parent directory" {
var tmp = tmpDir(.{});
defer tmp.cleanup();

9
lib/std/os/windows.zig
View File

@ -2972,6 +2972,15 @@ pub const FILE_INFORMATION_CLASS = enum(c_int) {
FileMaximumInformation,
};
pub const FILE_ATTRIBUTE_TAG_INFO = extern struct {
FileAttributes: DWORD,
ReparseTag: DWORD,
};
/// "If this bit is set, the file or directory represents another named entity in the system."
/// https://learn.microsoft.com/en-us/windows/win32/fileio/reparse-point-tags
pub const reparse_tag_name_surrogate_bit = 0x20000000;
pub const FILE_DISPOSITION_INFORMATION = extern struct {
DeleteFile: BOOLEAN,
};