tauri-winrt-notification 0.1.0

// Copyright 2017-2022 allenbenz <allenbenz@users.noreply.github.com>
// Copyright 2022-2022 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

#[cfg(target_env = "msvc")]
mod internal {
    #[link(name = "ntdll")]
    extern "system" {
        pub fn RtlGetNtVersionNumbers(major: *mut u32, minor: *mut u32, build: *mut u32);
    }
}

// The gnu target doesn't have access to this method at build time without installing extra things
// but we know it's in ntdll which will always be present at runtime.
#[cfg(target_env = "gnu")]
mod internal {
    use windows::{
        core::PCSTR,
        s,
        Win32::System::LibraryLoader::{GetModuleHandleA, GetProcAddress},
    };

    #[allow(non_upper_case_globals)]
    static mut CacheRtlGetNtVersionNumbers: Option<unsafe extern "system" fn() -> isize> = None;

    #[allow(non_snake_case)]
    pub unsafe fn RtlGetNtVersionNumbers(major: *mut u32, minor: *mut u32, build: *mut u32) {
        if CacheRtlGetNtVersionNumbers.is_none() {
            CacheRtlGetNtVersionNumbers = GetProcAddress(
                GetModuleHandleA(PCSTR::from_raw(s!("ntdll.dll").as_ptr())).unwrap_or_default(),
                PCSTR::from_raw(s!("RtlGetNtVersionNumbers").as_ptr()),
            );
        }

        if let Some(RtlGetNtVersionNumbers_FUNCTION) = CacheRtlGetNtVersionNumbers {
            std::intrinsics::transmute::<_, extern "system" fn(*mut u32, *mut u32, *mut u32)>(
                RtlGetNtVersionNumbers_FUNCTION,
            )(major, minor, build)
        } else {
            // RtlGetNtVersionNumbers goes as far back as xp.
            // Assume something else has gone wrong and guess we are newer than windows 8.1
            *major = 7;
        }
    }
}

pub fn is_newer_than_windows81() -> bool {
    let mut major = 0u32;
    let mut minor = 0u32;
    let mut build = 0u32;

    unsafe {
        internal::RtlGetNtVersionNumbers(&mut major, &mut minor, &mut build);
    }
    major > 6
}