Add some comments to prevent regression

GnomedDev · GnomedDev · commit 04334394337e · 2024-02-18T17:57:13.000Z
diff --git a/library/std/src/sys/pal/common/small_c_string.rs b/library/std/src/sys/pal/common/small_c_string.rs
@@ -27,13 +27,18 @@ pub fn run_with_cstr<T, F>(bytes: &[u8], mut f: F) -> io::Result<T>
 where
     F: FnMut(&CStr) -> io::Result<T>,
 {
+    // Dispatch and dyn erase the closure type to prevent mono bloat.
+    // See https://github.com/rust-lang/rust/pull/121101.
     if bytes.len() >= MAX_STACK_ALLOCATION {
         run_with_cstr_allocating(bytes, &mut f)
     } else {
         unsafe { run_with_cstr_stack(bytes, &mut f) }
     }
 }
 
+/// # Safety
+///
+/// `bytes` must have a length less than `MAX_STACK_ALLOCATION`.
 unsafe fn run_with_cstr_stack<T>(
     bytes: &[u8],
     f: &mut dyn FnMut(&CStr) -> io::Result<T>,

Original file line number	Diff line number	Diff line change
`@@ -27,13 +27,18 @@ pub fn run_with_cstr<T, F>(bytes: &[u8], mut f: F) -> io::Result<T>`
`27`	`27`	`where`
`28`	`28`	`F: FnMut(&CStr) -> io::Result<T>,`
`29`	`29`	`{`
	`30`	`+ // Dispatch and dyn erase the closure type to prevent mono bloat.`
	`31`	`+ // See https://github.com/rust-lang/rust/pull/121101.`
`30`	`32`	`if bytes.len() >= MAX_STACK_ALLOCATION {`
`31`	`33`	`run_with_cstr_allocating(bytes, &mut f)`
`32`	`34`	`} else {`
`33`	`35`	`unsafe { run_with_cstr_stack(bytes, &mut f) }`
`34`	`36`	`}`
`35`	`37`	`}`
`36`	`38`
	`39`	`+/// # Safety`
	`40`	`+///`
	`41`	+/// `bytes` must have a length less than `MAX_STACK_ALLOCATION`.
`37`	`42`	`unsafe fn run_with_cstr_stack<T>(`
`38`	`43`	`bytes: &[u8],`
`39`	`44`	`f: &mut dyn FnMut(&CStr) -> io::Result<T>,`