Lazy load ntdll functions on UWP

2 files changed, 61 insertions, 2 deletions

diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index 07b0610d463..929aaf5a266 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -19,6 +19,7 @@ pub use windows_sys::*;
 pub type DWORD = c_ulong;
 pub type NonZeroDWORD = NonZero_c_ulong;
 pub type LARGE_INTEGER = c_longlong;
+#[cfg_attr(target_vendor = "uwp", allow(unused))]
 pub type LONG = c_long;
 pub type UINT = c_uint;
 pub type WCHAR = u16;
@@ -50,6 +51,9 @@ pub type CONDITION_VARIABLE = RTL_CONDITION_VARIABLE;
 pub type SRWLOCK = RTL_SRWLOCK;
 pub type INIT_ONCE = RTL_RUN_ONCE;
 
+#[cfg(target_vendor = "uwp")]
+pub const STATUS_NOT_IMPLEMENTED: NTSTATUS = 0xC0000002_u32 as _;
+
 pub const CONDITION_VARIABLE_INIT: CONDITION_VARIABLE = CONDITION_VARIABLE { Ptr: ptr::null_mut() };
 pub const SRWLOCK_INIT: SRWLOCK = SRWLOCK { Ptr: ptr::null_mut() };
 pub const INIT_ONCE_STATIC_INIT: INIT_ONCE = INIT_ONCE { Ptr: ptr::null_mut() };
@@ -267,6 +271,8 @@ pub unsafe fn getaddrinfo(
     windows_sys::getaddrinfo(node.cast::<u8>(), service.cast::<u8>(), hints, res)
 }
 
+cfg_if::cfg_if! {
+if #[cfg(not(target_vendor = "uwp"))] {
 pub unsafe fn NtReadFile(
     filehandle: BorrowedHandle<'_>,
     event: HANDLE,
@@ -313,6 +319,8 @@ pub unsafe fn NtWriteFile(
         key.map(|k| k as *const u32).unwrap_or(ptr::null()),
     )
 }
+}
+}
 
 // Functions that aren't available on every version of Windows that we support,
 // but we still use them and just provide some form of a fallback implementation.
@@ -376,4 +384,54 @@ compat_fn_with_fallback! {
     ) -> NTSTATUS {
         panic!("keyed events not available")
     }
+
+    // These functions are available on UWP when lazily loaded. They will fail WACK if loaded statically.
+    #[cfg(target_vendor = "uwp")]
+    pub fn NtCreateFile(
+        filehandle: *mut HANDLE,
+        desiredaccess: FILE_ACCESS_RIGHTS,
+        objectattributes: *const OBJECT_ATTRIBUTES,
+        iostatusblock: *mut IO_STATUS_BLOCK,
+        allocationsize: *const i64,
+        fileattributes: FILE_FLAGS_AND_ATTRIBUTES,
+        shareaccess: FILE_SHARE_MODE,
+        createdisposition: NTCREATEFILE_CREATE_DISPOSITION,
+        createoptions: NTCREATEFILE_CREATE_OPTIONS,
+        eabuffer: *const ::core::ffi::c_void,
+        ealength: u32
+    ) -> NTSTATUS {
+        STATUS_NOT_IMPLEMENTED
+    }
+    #[cfg(target_vendor = "uwp")]
+    pub fn NtReadFile(
+        filehandle: BorrowedHandle<'_>,
+        event: HANDLE,
+        apcroutine: PIO_APC_ROUTINE,
+        apccontext: *mut c_void,
+        iostatusblock: &mut IO_STATUS_BLOCK,
+        buffer: *mut crate::mem::MaybeUninit<u8>,
+        length: ULONG,
+        byteoffset: Option<&LARGE_INTEGER>,
+        key: Option<&ULONG>
+    ) -> NTSTATUS {
+        STATUS_NOT_IMPLEMENTED
+    }
+    #[cfg(target_vendor = "uwp")]
+    pub fn NtWriteFile(
+        filehandle: BorrowedHandle<'_>,
+        event: HANDLE,
+        apcroutine: PIO_APC_ROUTINE,
+        apccontext: *mut c_void,
+        iostatusblock: &mut IO_STATUS_BLOCK,
+        buffer: *const u8,
+        length: ULONG,
+        byteoffset: Option<&LARGE_INTEGER>,
+        key: Option<&ULONG>
+    ) -> NTSTATUS {
+        STATUS_NOT_IMPLEMENTED
+    }
+    #[cfg(target_vendor = "uwp")]
+    pub fn RtlNtStatusToDosError(Status: NTSTATUS) -> ULONG {
+        Status as ULONG
+    }
 }
diff --git a/library/std/src/sys/windows/rand.rs b/library/std/src/sys/windows/rand.rs
index bca4e38d9f6..5d8fd13785a 100644
--- a/library/std/src/sys/windows/rand.rs
+++ b/library/std/src/sys/windows/rand.rs
@@ -1,5 +1,3 @@
-use crate::ffi::c_void;
-use crate::io;
 use crate::mem;
 use crate::ptr;
 use crate::sys::c;
@@ -25,6 +23,9 @@ pub fn hashmap_random_keys() -> (u64, u64) {
 #[cfg(not(target_vendor = "uwp"))]
 #[inline(never)]
 fn fallback_rng() -> (u64, u64) {
+    use crate::ffi::c_void;
+    use crate::io;
+
     let mut v = (0, 0);
     let ret = unsafe {
         c::RtlGenRandom(&mut v as *mut _ as *mut c_void, mem::size_of_val(&v) as c::ULONG)