rustdoc: Add some basic Safety sections to unsafe functions (#31639)

1 files changed, 12 insertions, 0 deletions

diff --git a/components/allocator/lib.rs b/components/allocator/lib.rs
index f8faaa080e9..20ac30e8022 100644
--- a/components/allocator/lib.rs
+++ b/components/allocator/lib.rs
@@ -16,6 +16,10 @@ mod platform {
     pub use jemallocator::Jemalloc as Allocator;
 
     /// Get the size of a heap block.
+    ///
+    /// # Safety
+    ///
+    /// Passing a non-heap allocated pointer to this function results in undefined behavior.
     pub unsafe extern "C" fn usable_size(ptr: *const c_void) -> usize {
         jemallocator::usable_size(ptr)
     }
@@ -35,6 +39,10 @@ mod platform {
     use std::os::raw::c_void;
 
     /// Get the size of a heap block.
+    ///
+    /// # Safety
+    ///
+    /// Passing a non-heap allocated pointer to this function results in undefined behavior.
     pub unsafe extern "C" fn usable_size(ptr: *const c_void) -> usize {
         #[cfg(target_vendor = "apple")]
         return libc::malloc_size(ptr);
@@ -56,6 +64,10 @@ mod platform {
     use winapi::um::heapapi::{GetProcessHeap, HeapSize, HeapValidate};
 
     /// Get the size of a heap block.
+    ///
+    /// # Safety
+    ///
+    /// Passing a non-heap allocated pointer to this function results in undefined behavior.
     pub unsafe extern "C" fn usable_size(mut ptr: *const c_void) -> usize {
         let heap = GetProcessHeap();