From e8abfef2aa8579121fbd13b8df84e8f68b533fa4 Mon Sep 17 00:00:00 2001 From: Jakub Konka Date: Wed, 5 Aug 2020 19:10:10 +0200 Subject: Add docs --- lib/std/os/windows.zig | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'lib/std') diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig index d3d3c4f210..03dbcdbd02 100644 --- a/lib/std/os/windows.zig +++ b/lib/std/os/windows.zig @@ -898,7 +898,6 @@ pub fn SetFilePointerEx_CURRENT_get(handle: HANDLE) SetFilePointerError!u64 { pub const GetFinalPathNameByHandleError = error{ FileNotFound, - SystemResources, NameTooLong, Unexpected, }; @@ -963,9 +962,19 @@ pub fn GetFinalPathNameByHandle(hFile: HANDLE, out_buffer: []u16) GetFinalPathNa break :blk @as([*]const u16, object_name.Name.Buffer)[0..object_name.Name.Length / 2]; }; - // Since `NtQueryObject` returns a fully-qualified NT path, we need to translate - // the result into a Win32/DOS path (e.g., \Device\HarddiskVolume4\foo would become - // C:\foo). + // By now, we got a a fully-qualified NT path, which we need to translate + // into a Win32/DOS path, for instance: + // \Device\HarddiskVolume4\foo => C:\foo + // + // NOTE: + // I couldn't figure out a better way of doing this unfortunately... + // This snippet below is in part based around `QueryDosDeviceW` implementation + // found in Wine. The trick with `NtQueryDirectoryObject` for some reason + // only lists `\DosDevices\Global` as the only SymblinkObject available, which + // means it's not possible to query the kernel for all available DOS volume name + // symlinks. + // TODO investigate! + // Wine source: https://source.winehq.com/git/wine.git/blob/HEAD:/dlls/kernelbase/volume.c#l1009 const dos_drive_letters = &[_]u16{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' }; var query_path = [_]u16{ '\\', 'D', 'o', 's', 'D', 'e', 'v', 'i', 'c', 'e', 's', '\\', 'C', ':' }; for (dos_drive_letters) |drive_letter| { @@ -1010,14 +1019,17 @@ pub fn GetFinalPathNameByHandle(hFile: HANDLE, out_buffer: []u16) GetFinalPathNa const link_path = @as([*]const u16, link.Buffer)[0..link.Length / 2]; const idx = std.mem.indexOf(u16, object_path, link_path) orelse continue; - // TODO check the provided buffer is actually big enough. + // TODO is this the most appropriate error here? + if (out_buffer.len < drive.len + object_path.len) return error.NameTooLong; + std.mem.copy(u16, out_buffer[0..], drive[0..]); std.mem.copy(u16, out_buffer[2..], object_path[link_path.len..]); return out_buffer[0..object_path.len - link_path.len + 2]; } - // If we're here, that means there was no match so error out! + // If we're here, that means there was no match so we panic! + // TODO should we actually panic here or return an error instead? unreachable; } -- cgit v1.2.3