A MIR transform that checks pointers are aligned

library/core/src/panicking.rs

@@ -159,6 +159,20 @@ fn panic_bounds_check(index: usize, len: usize) -> ! {
     panic!("index out of bounds: the len is {len} but the index is {index}")
 }
 
+#[cold]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[track_caller]
+#[cfg_attr(not(bootstrap), lang = "panic_misaligned_pointer_dereference")] // needed by codegen for panic on misaligned pointer deref
+fn panic_misaligned_pointer_dereference(required: usize, found: usize) -> ! {
+    if cfg!(feature = "panic_immediate_abort") {
+        super::intrinsics::abort()
+    }
+
+    panic!(
+        "misaligned pointer dereference: address must be a multiple of {required:#x} but is {found:#x}"
+    )
+}
+
 /// Panic because we cannot unwind out of a function.
 ///
 /// This function is called directly by the codegen backend, and must not have