zig/lib/std/zig/system/windows.zig

46 lines
1.9 KiB
Zig

// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2020 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const std = @import("std");
pub const WindowsVersion = std.Target.Os.WindowsVersion;
/// Returns the highest known WindowsVersion deduced from reported runtime information.
/// Discards information about in-between versions we don't differentiate.
pub fn detectRuntimeVersion() WindowsVersion {
var version_info: std.os.windows.RTL_OSVERSIONINFOW = undefined;
version_info.dwOSVersionInfoSize = @sizeOf(@TypeOf(version_info));
switch (std.os.windows.ntdll.RtlGetVersion(&version_info)) {
.SUCCESS => {},
else => unreachable,
}
// Starting from the system infos build a NTDDI-like version
// constant whose format is:
// B0 B1 B2 B3
// `---` `` ``--> Sub-version (Starting from Windows 10 onwards)
// \ `--> Service pack (Always zero in the constants defined)
// `--> OS version (Major & minor)
const os_ver: u16 = @intCast(u16, version_info.dwMajorVersion & 0xff) << 8 |
@intCast(u16, version_info.dwMinorVersion & 0xff);
const sp_ver: u8 = 0;
const sub_ver: u8 = if (os_ver >= 0x0A00) subver: {
// There's no other way to obtain this info beside
// checking the build number against a known set of
// values
var last_idx: usize = 0;
for (WindowsVersion.known_win10_build_numbers) |build, i| {
if (version_info.dwBuildNumber >= build)
last_idx = i;
}
break :subver @truncate(u8, last_idx);
} else 0;
const version: u32 = @as(u32, os_ver) << 16 | @as(u16, sp_ver) << 8 | sub_ver;
return @intToEnum(WindowsVersion, version);
}