Auto merge of #75912 - scottmcm:manuallydrop-vs-forget, r=Mark-Simulacrum

[rust.git] / library / std / src / sys / windows / mod.rs

diff --git a/library/std/src/sys/windows/mod.rs b/library/std/src/sys/windows/mod.rs
index 9a52371280e159ffb2e0115f8af19086eb90570d..a0d5a7471d8af67a4a64c94d2a4477db249d7ac2 100644 (file)
--- a/library/std/src/sys/windows/mod.rs
+++ b/library/std/src/sys/windows/mod.rs
@@ -99,43 +99,28 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
 
 pub fn unrolled_find_u16s(needle: u16, haystack: &[u16]) -> Option<usize> {
     let ptr = haystack.as_ptr();
-    let mut len = haystack.len();
     let mut start = &haystack[..];
 
     // For performance reasons unfold the loop eight times.
-    while len >= 8 {
-        if start[0] == needle {
-            return Some((start.as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[1] == needle {
-            return Some((start[1..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[2] == needle {
-            return Some((start[2..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[3] == needle {
-            return Some((start[3..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[4] == needle {
-            return Some((start[4..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[5] == needle {
-            return Some((start[5..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[6] == needle {
-            return Some((start[6..].as_ptr() as usize - ptr as usize) / 2);
-        }
-        if start[7] == needle {
-            return Some((start[7..].as_ptr() as usize - ptr as usize) / 2);
+    while start.len() >= 8 {
+        macro_rules! if_return {
+            ($($n:literal,)+) => {
+                $(
+                    if start[$n] == needle {
+                        return Some((&start[$n] as *const u16 as usize - ptr as usize) / 2);
+                    }
+                )+
+            }
         }
 
+        if_return!(0, 1, 2, 3, 4, 5, 6, 7,);
+
         start = &start[8..];
-        len -= 8;
     }
 
-    for (i, c) in start.iter().enumerate() {
+    for c in start {
         if *c == needle {
-            return Some((start.as_ptr() as usize - ptr as usize) / 2 + i);
+            return Some((c as *const u16 as usize - ptr as usize) / 2);
         }
     }
     None
@@ -315,14 +300,10 @@ pub fn dur2timeout(dur: Duration) -> c::DWORD {
         .unwrap_or(c::INFINITE)
 }
 
-// On Windows, use the processor-specific __fastfail mechanism.  In Windows 8
-// and later, this will terminate the process immediately without running any
-// in-process exception handlers.  In earlier versions of Windows, this
-// sequence of instructions will be treated as an access violation,
-// terminating the process but without necessarily bypassing all exception
-// handlers.
-//
-// https://docs.microsoft.com/en-us/cpp/intrinsics/fastfail
+/// Use `__fastfail` to abort the process
+///
+/// This is the same implementation as in libpanic_abort's `__rust_start_panic`. See
+/// that function for more information on `__fastfail`
 #[allow(unreachable_code)]
 pub fn abort_internal() -> ! {
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]