Add fallback impl for GetSystemTimeAsFileTime

(only used for NT 3.1)

Author: seritools

library/std/src/sys/windows/c.rs

@@ -341,6 +341,15 @@ compat_fn_with_fallback! {
     pub fn GetTempPath2W(bufferlength: u32, buffer: PWSTR) -> u32 {
         GetTempPathW(bufferlength, buffer)
     }
+
+    // >= 95 / NT 3.5
+    // https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimeasfiletime
+    pub fn GetSystemTimeAsFileTime(lpSystemTimeAsFileTime: *mut FILETIME) -> () {
+        // implementation based on old MSDN docs
+        let mut st: SYSTEMTIME = crate::mem::zeroed();
+        GetSystemTime(&mut st);
+        crate::sys::cvt(SystemTimeToFileTime(&st, lpSystemTimeAsFileTime)).unwrap();
+    }
 }
 
 compat_fn_optional! {

library/std/src/sys/windows/c/windows_sys.lst

@@ -2608,3 +2608,7 @@ Windows.Win32.System.Threading.LeaveCriticalSection
 Windows.Win32.System.Threading.DeleteCriticalSection
 Windows.Win32.System.Threading.SRWLOCK
 Windows.Win32.System.Threading.CONDITION_VARIABLE
+
+// system time fallback
+Windows.Win32.System.SystemInformation.GetSystemTime
+Windows.Win32.System.Time.SystemTimeToFileTime

library/std/src/sys/windows/c/windows_sys.rs

@@ -381,6 +381,10 @@ extern "system" {
     pub fn GetSystemInfo(lpsysteminfo: *mut SYSTEM_INFO) -> ();
 }
 #[link(name = "kernel32")]
+extern "system" {
+    pub fn GetSystemTime(lpsystemtime: *mut SYSTEMTIME) -> ();
+}
+#[link(name = "kernel32")]
 extern "system" {
     pub fn GetSystemTimeAsFileTime(lpsystemtimeasfiletime: *mut FILETIME) -> ();
 }
@@ -594,6 +598,11 @@ extern "system" {
     pub fn SwitchToThread() -> BOOL;
 }
 #[link(name = "kernel32")]
+extern "system" {
+    pub fn SystemTimeToFileTime(lpsystemtime: *const SYSTEMTIME, lpfiletime: *mut FILETIME)
+    -> BOOL;
+}
+#[link(name = "kernel32")]
 extern "system" {
     pub fn TerminateProcess(hprocess: HANDLE, uexitcode: u32) -> BOOL;
 }
@@ -4063,6 +4072,23 @@ pub const SYMLINK_FLAG_RELATIVE: u32 = 1u32;
 pub type SYNCHRONIZATION_ACCESS_RIGHTS = u32;
 pub const SYNCHRONIZE: FILE_ACCESS_RIGHTS = 1048576u32;
 #[repr(C)]
+pub struct SYSTEMTIME {
+    pub wYear: u16,
+    pub wMonth: u16,
+    pub wDayOfWeek: u16,
+    pub wDay: u16,
+    pub wHour: u16,
+    pub wMinute: u16,
+    pub wSecond: u16,
+    pub wMilliseconds: u16,
+}
+impl ::core::marker::Copy for SYSTEMTIME {}
+impl ::core::clone::Clone for SYSTEMTIME {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[repr(C)]
 pub struct SYSTEM_INFO {
     pub Anonymous: SYSTEM_INFO_0,
     pub dwPageSize: u32,