Feedback comments

src/Common/src/Interop/Windows/kernel32/Interop.FileTimeToSystemTime.cs

@@ -9,7 +9,7 @@ internal partial class Interop
 {
     internal partial class Kernel32
     {
-        [DllImport(Libraries.Kernel32, SetLastError = true)]
-        internal static unsafe extern bool FileTimeToSystemTime(ref long lpFileTime, ref FullSystemTime lpSystemTime);
+        [DllImport(Libraries.Kernel32)]
+        internal static unsafe extern bool FileTimeToSystemTime(in long lpFileTime, out Interop.Kernel32.SYSTEMTIME lpSystemTime);
     }
 }

src/Common/src/Interop/Windows/kernel32/Interop.FullSystemTime.cs

@@ -9,21 +9,24 @@ internal partial class Interop
 {
     internal partial class Kernel32
     {
-        // FullSystemTime struct matches Windows SYSTEMTIME struct, except we added the extra nanoSeconds field to store
+        // FullSystemTime struct matches Windows SYSTEMTIME struct, except we added the extra hundredNanoSecond field to store
         // more precise time.
         [StructLayout(LayoutKind.Sequential)]
         internal struct FullSystemTime
         {
+            internal Interop.Kernel32.SYSTEMTIME systemTime;
+            internal long   hundredNanoSecond;
+
             internal FullSystemTime(int year, int month, DayOfWeek dayOfWeek, int day, int hour, int minute, int second)
             {
-                wYear = (ushort) year;
-                wMonth = (ushort) month;
-                wDayOfWeek = (ushort) dayOfWeek;
-                wDay = (ushort) day;
-                wHour = (ushort) hour;
-                wMinute = (ushort) minute;
-                wSecond = (ushort) second;
-                wMillisecond = 0;
+                systemTime.Year = (ushort) year;
+                systemTime.Month = (ushort) month;
+                systemTime.DayOfWeek = (ushort) dayOfWeek;
+                systemTime.Day = (ushort) day;
+                systemTime.Hour = (ushort) hour;
+                systemTime.Minute = (ushort) minute;
+                systemTime.Second = (ushort) second;
+                systemTime.Milliseconds = 0;
                 hundredNanoSecond = 0;
             }
 
@@ -34,26 +37,17 @@ internal FullSystemTime(long ticks)
                 int year, month, day;
                 dt.GetDatePart(out year, out month, out day);
 
-                wYear = (ushort) year;
-                wMonth = (ushort) month;
-                wDayOfWeek = (ushort) dt.DayOfWeek;
-                wDay = (ushort) day;
-                wHour = (ushort) dt.Hour;
-                wMinute = (ushort) dt.Minute;
-                wSecond = (ushort) dt.Second;
-                wMillisecond = (ushort) dt.Millisecond;
+                systemTime.Year = (ushort) year;
+                systemTime.Month = (ushort) month;
+                systemTime.DayOfWeek = (ushort) dt.DayOfWeek;
+                systemTime.Day = (ushort) day;
+                systemTime.Hour = (ushort) dt.Hour;
+                systemTime.Minute = (ushort) dt.Minute;
+                systemTime.Second = (ushort) dt.Second;
+                systemTime.Milliseconds = (ushort) dt.Millisecond;
                 hundredNanoSecond = 0;
             }
 
-            internal ushort wYear;
-            internal ushort wMonth;
-            internal ushort wDayOfWeek;
-            internal ushort wDay;
-            internal ushort wHour;
-            internal ushort wMinute;
-            internal ushort wSecond;
-            internal ushort wMillisecond;
-            internal long   hundredNanoSecond;
         };
     }
 }

src/Common/src/Interop/Windows/kernel32/Interop.GetProcessInformation.cs

@@ -11,7 +11,7 @@ internal partial class Kernel32
     {
         internal const int ProcessLeapSecondInfo = 8;
 
-        [DllImport(Libraries.Kernel32, SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = true)]
+        [DllImport(Libraries.Kernel32)]
         internal static extern bool GetProcessInformation(IntPtr hProcess, int ProcessInformationClass, ref long processInformation, int ProcessInformationSize);
     }
 }

src/Common/src/Interop/Windows/kernel32/Interop.SystemTimeToFileTime.cs

@@ -8,8 +8,7 @@ internal partial class Interop
 {
     internal partial class Kernel32
     {
-        // api-ms-win-core-timezone-l1-1-0.dll
-        [DllImport(Libraries.Kernel32, SetLastError = true)]
-        internal static extern bool SystemTimeToFileTime(ref FullSystemTime lpSystemTime, out long lpFileTime);
+        [DllImport(Libraries.Kernel32)]
+        internal static extern bool SystemTimeToFileTime(in Interop.Kernel32.SYSTEMTIME lpSystemTime, out long lpFileTime);
     }
 }

src/Common/src/Interop/Windows/kernel32/Interop.TzSpecificLocalTimeToSystemTime.cs

@@ -9,7 +9,10 @@ internal partial class Interop
 {
     internal partial class Kernel32
     {
-        [DllImport(Libraries.Kernel32, SetLastError = true)]
-        internal static extern bool TzSpecificLocalTimeToSystemTime(IntPtr lpTimeZoneInformation, ref FullSystemTime lpLocalTime, ref FullSystemTime lpUniversalTime);
+        [DllImport(Libraries.Kernel32)]
+        internal static extern bool TzSpecificLocalTimeToSystemTime(
+                                        IntPtr lpTimeZoneInformation,
+                                        in Interop.Kernel32.SYSTEMTIME lpLocalTime,
+                                        out Interop.Kernel32.SYSTEMTIME lpUniversalTime);
     }
 }

src/Common/src/Interop/Windows/NtDll/Interop.NtQuerySystemInformation.cs → src/System.Private.CoreLib/shared/Interop/Windows/NtDll/Interop.NtQuerySystemInformation.cs

@@ -9,8 +9,8 @@ internal partial class Interop
 {
     internal partial class NtDll
     {
-        [DllImport(Libraries.NtDll, SetLastError = true)]
-        internal static unsafe extern int NtQuerySystemInformation(int SystemInformationClass, void* SystemInformation, int SystemInformationLength, IntPtr ReturnLength);
+        [DllImport(Libraries.NtDll)]
+        internal static unsafe extern int NtQuerySystemInformation(int SystemInformationClass, void* SystemInformation, int SystemInformationLength, uint* ReturnLength);
 
         [StructLayout(LayoutKind.Sequential)]
         internal struct SYSTEM_LEAP_SECOND_INFORMATION

src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems

@@ -859,6 +859,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\Kernel32\Interop.WriteFile_SafeHandle_NativeOverlapped.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\Normaliz\Interop.Idna.cs" Condition="'$(EnableDummyGlobalizationImplementation)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\Normaliz\Interop.Normalization.cs" Condition="'$(EnableDummyGlobalizationImplementation)' != 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\NtDll\Interop.NtQuerySystemInformation.cs" Condition="'$(EnableWinRT)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\Ole32\Interop.CoCreateGuid.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\OleAut32\Interop.SysAllocStringLen.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Interop\Windows\OleAut32\Interop.SysFreeString.cs" />

src/System.Private.CoreLib/shared/System/DateTime.cs

@@ -196,7 +196,7 @@ public DateTime(int year, int month, int day, Calendar calendar)
         //
         public DateTime(int year, int month, int day, int hour, int minute, int second)
         {
-            if (second == 60 && s_isLeapSecondsSupportedSystem && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
+            if (second == 60 && s_systemSupportsLeapSeconds && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
             {
                 // if we have leap second (second = 60) then we'll need to check if it is valid time.
                 // if it is valid, then we adjust the second to 59 so DateTime will consider this second is last second
@@ -214,7 +214,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
                 throw new ArgumentException(SR.Argument_InvalidDateTimeKind, nameof(kind));
             }
 
-            if (second == 60 && s_isLeapSecondsSupportedSystem && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, kind))
+            if (second == 60 && s_systemSupportsLeapSeconds && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, kind))
             {
                 // if we have leap second (second = 60) then we'll need to check if it is valid time.
                 // if it is valid, then we adjust the second to 59 so DateTime will consider this second is last second
@@ -236,7 +236,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
                 throw new ArgumentNullException(nameof(calendar));
 
             int originalSecond = second;
-            if (second == 60 && s_isLeapSecondsSupportedSystem)
+            if (second == 60 && s_systemSupportsLeapSeconds)
             {
                 // Reset the second value now and then we'll validate it later when we get the final Gregorian date.
                 second = 59;
@@ -264,7 +264,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
                 throw new ArgumentOutOfRangeException(nameof(millisecond), SR.Format(SR.ArgumentOutOfRange_Range, 0, MillisPerSecond - 1));
             }
 
-            if (second == 60 && s_isLeapSecondsSupportedSystem && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
+            if (second == 60 && s_systemSupportsLeapSeconds && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
             {
                 // if we have leap second (second = 60) then we'll need to check if it is valid time.
                 // if it is valid, then we adjust the second to 59 so DateTime will consider this second is last second
@@ -291,7 +291,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
                 throw new ArgumentException(SR.Argument_InvalidDateTimeKind, nameof(kind));
             }
 
-            if (second == 60 && s_isLeapSecondsSupportedSystem && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, kind))
+            if (second == 60 && s_systemSupportsLeapSeconds && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, kind))
             {
                 // if we have leap second (second = 60) then we'll need to check if it is valid time.
                 // if it is valid, then we adjust the second to 59 so DateTime will consider this second is last second
@@ -320,7 +320,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
             }
 
             int originalSecond = second;
-            if (second == 60 && s_isLeapSecondsSupportedSystem)
+            if (second == 60 && s_systemSupportsLeapSeconds)
             {
                 // Reset the second value now and then we'll validate it later when we get the final Gregorian date.
                 second = 59;
@@ -356,7 +356,7 @@ public DateTime(int year, int month, int day, int hour, int minute, int second,
             }
 
             int originalSecond = second;
-            if (second == 60 && s_isLeapSecondsSupportedSystem)
+            if (second == 60 && s_systemSupportsLeapSeconds)
             {
                 // Reset the second value now and then we'll validate it later when we get the final Gregorian date.
                 second = 59;
@@ -427,8 +427,6 @@ private DateTime(SerializationInfo info, StreamingContext context)
             }
         }
 
-
-
         internal long InternalTicks
         {
             get
@@ -804,6 +802,23 @@ public static DateTime FromFileTime(long fileTime)
             return FromFileTimeUtc(fileTime).ToLocalTime();
         }
 
+        public static DateTime FromFileTimeUtc(long fileTime)
+        {
+            if (fileTime < 0 || fileTime > MaxTicks - FileTimeOffset)
+            {
+                throw new ArgumentOutOfRangeException(nameof(fileTime), SR.ArgumentOutOfRange_FileTimeInvalid);
+            }
+
+            if (s_systemSupportsLeapSeconds)
+            {
+                return FromFileTimeLeapSecondsAware(fileTime);
+            }
+
+            // This is the ticks in Universal time for this fileTime.
+            long universalTicks = fileTime + FileTimeOffset;
+            return new DateTime(universalTicks, DateTimeKind.Utc);
+        }
+
         // Creates a DateTime from an OLE Automation Date.
         //
         public static DateTime FromOADate(double d)
@@ -1296,6 +1311,25 @@ public long ToFileTime()
             return ToUniversalTime().ToFileTimeUtc();
         }
 
+        public long ToFileTimeUtc()
+        {
+            // Treats the input as universal if it is not specified
+            long ticks = ((InternalKind & LocalMask) != 0) ? ToUniversalTime().InternalTicks : this.InternalTicks;
+
+            if (s_systemSupportsLeapSeconds)
+            {
+                return ToFileTimeLeapSecondsAware(ticks);
+            }
+
+            ticks -= FileTimeOffset;
+            if (ticks < 0)
+            {
+                throw new ArgumentOutOfRangeException(null, SR.ArgumentOutOfRange_FileTimeInvalid);
+            }
+
+            return ticks;
+        }
+
         public DateTime ToLocalTime()
         {
             return ToLocalTime(false);
@@ -1650,7 +1684,7 @@ internal static bool TryCreate(int year, int month, int day, int hour, int minut
 
             if (second == 60)
             {
-                if (s_isLeapSecondsSupportedSystem && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
+                if (s_systemSupportsLeapSeconds && IsValidTimeWithLeapSeconds(year, month, day, hour, minute, second, DateTimeKind.Unspecified))
                 {
                     // if we have leap second (second = 60) then we'll need to check if it is valid time.
                     // if it is valid, then we adjust the second to 59 so DateTime will consider this second is last second

src/System.Private.CoreLib/shared/System/DateTimeOffset.cs

@@ -111,7 +111,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             _offsetMinutes = ValidateOffset(offset);
 
             int originalSecond = second;
-            if (second == 60 && DateTime.s_isLeapSecondsSupportedSystem)
+            if (second == 60 && DateTime.s_systemSupportsLeapSeconds)
             {
                 // Reset the leap second to 59 for now and then we'll validate it after getting the final UTC time.
                 second = 59;
@@ -133,7 +133,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             _offsetMinutes = ValidateOffset(offset);
 
             int originalSecond = second;
-            if (second == 60 && DateTime.s_isLeapSecondsSupportedSystem)
+            if (second == 60 && DateTime.s_systemSupportsLeapSeconds)
             {
                 // Reset the leap second to 59 for now and then we'll validate it after getting the final UTC time.
                 second = 59;
@@ -155,7 +155,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             _offsetMinutes = ValidateOffset(offset);
 
             int originalSecond = second;
-            if (second == 60 && DateTime.s_isLeapSecondsSupportedSystem)
+            if (second == 60 && DateTime.s_systemSupportsLeapSeconds)
             {
                 // Reset the leap second to 59 for now and then we'll validate it after getting the final UTC time.
                 second = 59;

src/System.Private.CoreLib/src/System.Private.CoreLib.csproj

@@ -370,9 +370,6 @@
     <Compile Include="..\..\Common\src\Interop\Windows\kernel32\Interop.TzSpecificLocalTimeToSystemTime.cs">
       <Link>Interop\Windows\kernel32\Interop.TzSpecificLocalTimeToSystemTime.cs</Link>
     </Compile>
-    <Compile Include="..\..\Common\src\Interop\Windows\NtDll\Interop.NtQuerySystemInformation.cs" Condition="'$(EnableWinRT)'!='true'">
-      <Link>Interop\Windows\NtDll\Interop.NtQuerySystemInformation.cs</Link>
-    </Compile>
     <Compile Include="..\..\Common\src\Interop\Windows\kernel32\Interop.GetProcessInformation.cs" Condition="'$(EnableWinRT)'=='true'">
       <Link>Interop\Windows\kernel32\Interop.GetProcessInformation.cs</Link>
     </Compile>

src/System.Private.CoreLib/src/System/DateTime.Unix.CoreRT.cs

@@ -6,40 +6,18 @@ namespace System
 {
     public readonly partial struct DateTime
     {
-        internal static readonly bool s_isLeapSecondsSupportedSystem = false;
+        internal const bool s_systemSupportsLeapSeconds = false;
 
         public static DateTime UtcNow
         {
             get
             {
-                // For performance, use a private constructor that does not validate arguments.
                 return new DateTime(((ulong)(Interop.Sys.GetSystemTimeAsTicks() + DateTime.UnixEpochTicks)) | KindUtc);
             }
         }
 
-        public static DateTime FromFileTimeUtc(long fileTime)
-        {
-            if (fileTime < 0 || fileTime > MaxTicks - FileTimeOffset)
-            {
-                throw new ArgumentOutOfRangeException(nameof(fileTime), SR.ArgumentOutOfRange_FileTimeInvalid);
-            }
-
-            // This is the ticks in Universal time for this fileTime.
-            long universalTicks = fileTime + FileTimeOffset;
-            return new DateTime(universalTicks, DateTimeKind.Utc);
-        }
-
-        public long ToFileTimeUtc()
-        {
-            // Treats the input as universal if it is not specified
-            long ticks = ((InternalKind & LocalMask) != 0) ? ToUniversalTime().InternalTicks : this.InternalTicks;
-            ticks -= FileTimeOffset;
-            if (ticks < 0)
-            {
-                throw new ArgumentOutOfRangeException(null, SR.ArgumentOutOfRange_FileTimeInvalid);
-            }
-            return ticks;
-        }
+        internal static DateTime FromFileTimeLeapSecondsAware(long fileTime) => default;
+        internal static long ToFileTimeLeapSecondsAware(long ticks) => default;
 
         // IsValidTimeWithLeapSeconds is not expected to be called at all for now on non-Windows platforms
         internal static bool IsValidTimeWithLeapSeconds(int year, int month, int day, int hour, int minute, int second, DateTimeKind kind) => false;

src/System.Private.CoreLib/src/System/DateTime.Win32.cs

@@ -6,14 +6,14 @@ namespace System
 {
     public readonly partial struct DateTime
     {
-        private static unsafe bool IsLeapSecondsSupportedSystem()
+        private static unsafe bool SystemSupportsLeapSeconds()
         {
             Interop.NtDll.SYSTEM_LEAP_SECOND_INFORMATION slsi = new Interop.NtDll.SYSTEM_LEAP_SECOND_INFORMATION();
             return Interop.NtDll.NtQuerySystemInformation(
                                     Interop.NtDll.SystemLeapSecondInformation,
                                     (void *) &slsi,
                                     sizeof(Interop.NtDll.SYSTEM_LEAP_SECOND_INFORMATION),
-                                    IntPtr.Zero) == 0 && slsi.Enabled;
+                                    null) == 0 && slsi.Enabled;
         }
     }
 }

src/System.Private.CoreLib/src/System/DateTime.WinRT.cs

@@ -6,7 +6,7 @@ namespace System
 {
     public readonly partial struct DateTime
     {
-        private static unsafe bool IsLeapSecondsSupportedSystem()
+        private static unsafe bool SystemSupportsLeapSeconds()
         {
             long l = 0;