Revert "os2: Don't try to translate Windows file attributes to Unix mode flags"

This reverts commit 95923c2059.
It'll be updated later.

core/os/os2/file_windows.odin

@@ -12,30 +12,7 @@ import win32 "core:sys/windows"
 
 INVALID_HANDLE :: ~uintptr(0)
 
-// NOTE(Jeroen): We don't translate mode flags for Linux when given to `chmod`.
+S_IWRITE :: 0o200
-//               Let's not do so for Windows for `chmod` or `read_directory_iterator` either.
-//               They're *not* portable between Windows and non-Windows platforms.
-//
-//               It also leads to information loss as flags like Archive, Hidden and System have no equivalent there.
-//               We can of course parse them so we can set the `.Symlink` and `.Directory` type, but we shouldn't pretend
-//               that 0o644 is meaningful when returned as a mode.
-//               `C:\bootmgr` as an example has attributes read only, hidden, system, archive. In no way is it sensible to replace that with 0o444.
-FILE_ATTRIBUTE_READONLY            :: win32.FILE_ATTRIBUTE_READONLY            // 0x00000001
-FILE_ATTRIBUTE_HIDDEN              :: win32.FILE_ATTRIBUTE_HIDDEN              // 0x00000002
-FILE_ATTRIBUTE_SYSTEM              :: win32.FILE_ATTRIBUTE_SYSTEM              // 0x00000004
-FILE_ATTRIBUTE_DIRECTORY           :: win32.FILE_ATTRIBUTE_DIRECTORY           // 0x00000010
-FILE_ATTRIBUTE_ARCHIVE             :: win32.FILE_ATTRIBUTE_ARCHIVE             // 0x00000020
-FILE_ATTRIBUTE_DEVICE              :: win32.FILE_ATTRIBUTE_DEVICE              // 0x00000040
-FILE_ATTRIBUTE_NORMAL              :: win32.FILE_ATTRIBUTE_NORMAL              // 0x00000080
-FILE_ATTRIBUTE_TEMPORARY           :: win32.FILE_ATTRIBUTE_TEMPORARY           // 0x00000100
-FILE_ATTRIBUTE_SPARSE_FILE         :: win32.FILE_ATTRIBUTE_SPARSE_FILE         // 0x00000200
-FILE_ATTRIBUTE_REPARSE_Point       :: win32.FILE_ATTRIBUTE_REPARSE_Point       // 0x00000400
-FILE_ATTRIBUTE_REPARSE_POINT       :: win32.FILE_ATTRIBUTE_REPARSE_POINT       // 0x00000400
-FILE_ATTRIBUTE_COMPRESSED          :: win32.FILE_ATTRIBUTE_COMPRESSED          // 0x00000800
-FILE_ATTRIBUTE_OFFLINE             :: win32.FILE_ATTRIBUTE_OFFLINE             // 0x00001000
-FILE_ATTRIBUTE_NOT_CONTENT_INDEXED :: win32.FILE_ATTRIBUTE_NOT_CONTENT_INDEXED // 0x00002000
-FILE_ATTRIBUTE_ENCRYPTED           :: win32.FILE_ATTRIBUTE_ENCRYPTED           // 0x00004000
-
 _ERROR_BAD_NETPATH :: 53
 MAX_RW :: 1<<30
 
@@ -145,7 +122,7 @@ _open_internal :: proc(name: string, flags: File_Flags, perm: int) -> (handle: u
 	}
 
 	attrs: u32 = win32.FILE_ATTRIBUTE_NORMAL|win32.FILE_FLAG_BACKUP_SEMANTICS
-	if u32(perm) & FILE_ATTRIBUTE_NORMAL == 0 {
+	if perm & S_IWRITE == 0 {
 		attrs = win32.FILE_ATTRIBUTE_READONLY
 		if create_mode == win32.CREATE_ALWAYS {
 			// NOTE(bill): Open has just asked to create a file in read-only mode.
@@ -771,10 +748,20 @@ _fchmod :: proc(f: ^File, mode: int) -> Error {
 	if f == nil || f.impl == nil {
 		return nil
 	}
+	d: win32.BY_HANDLE_FILE_INFORMATION
+	if !win32.GetFileInformationByHandle(_handle(f), &d) {
+		return _get_platform_error()
+	}
+	attrs := d.dwFileAttributes
+	if mode & S_IWRITE != 0 {
+		attrs &~= win32.FILE_ATTRIBUTE_READONLY
+	} else {
+		attrs |= win32.FILE_ATTRIBUTE_READONLY
+	}
 
 	info: win32.FILE_BASIC_INFO
-	info.FileAttributes = win32.DWORD(mode)
+	info.FileAttributes = attrs
-	if !win32.SetFileInformationByHandle(_handle(f), .FileBasicInfo, &info, size_of(info)) {
+	if !win32.SetFileInformationByHandle(_handle(f), .FileBasicInfo, &info, size_of(d)) {
 		return _get_platform_error()
 	}
 	return nil

core/os/os2/stat_windows.odin

@@ -212,15 +212,11 @@ _file_type_from_create_file :: proc(wname: win32.wstring, create_file_attributes
 }
 
 _file_type_mode_from_file_attributes :: proc(file_attributes: win32.DWORD, h: win32.HANDLE, ReparseTag: win32.DWORD) -> (type: File_Type, mode: int) {
-	// NOTE(Jeroen): We don't translate mode flags for Linux when given to `chmod`.
+	if file_attributes & win32.FILE_ATTRIBUTE_READONLY != 0 {
-	//               Let's not do so for Windows for `chmod` or `read_directory_iterator` either.
+		mode |= 0o444
-	//               They're *not* portable between Windows and non-Windows platforms.
+	} else {
-	//
+		mode |= 0o666
-	//               It also leads to information loss as flags like Archive, Hidden and System have no equivalent there.
+	}
-	//               We can of course parse them so we can set the `.Symlink` and `.Directory` type, but we shouldn't pretend
-	//               that 0o644 is meaningful when returned as a mode.
-	//               `C:\bootmgr` as an example has attributes read only, hidden, system, archive. In no way is it sensible to replace that with 0o444.
-	mode = int(file_attributes)
 
 	is_sym := false
 	if file_attributes & win32.FILE_ATTRIBUTE_REPARSE_POINT == 0 {
@@ -233,6 +229,7 @@ _file_type_mode_from_file_attributes :: proc(file_attributes: win32.DWORD, h: wi
 		type = .Symlink
 	} else if file_attributes & win32.FILE_ATTRIBUTE_DIRECTORY != 0 {
 		type = .Directory
+		mode |= 0o111
 	} else if h != nil {
 		type = file_type(h)
 	}