cfg(kcfi)

Author: Darksonn

Diff for: core/src/fmt/mod.rs

@@ -7,7 +7,7 @@ use crate::char::{EscapeDebugExtArgs, MAX_LEN_UTF8};
 use crate::marker::PhantomData;
 use crate::num::fmt as numfmt;
 use crate::ops::Deref;
-use crate::{iter, result, str};
+use crate::{iter, mem, result, str};
 
 mod builders;
 #[cfg(not(no_fp_fmt_parse))]

Diff for: core/src/fmt/rt.rs

@@ -72,6 +72,13 @@ macro_rules! argument_new {
             // a `fn(&T, ...)`, so the invariant is maintained.
             ty: ArgumentType::Placeholder {
                 value: NonNull::<$t>::from_ref($x).cast(),
+                #[cfg(not(any(sanitize = "cfi", sanitize = "kcfi")))]
+                formatter: {
+                    let f: fn(&$t, &mut Formatter<'_>) -> Result = $f;
+                    // SAFETY: This is only called with `value`, which has the right type.
+                    unsafe { mem::transmute(f) }
+                },
+                #[cfg(any(sanitize = "cfi", sanitize = "kcfi"))]
                 formatter: |ptr: NonNull<()>, fmt: &mut Formatter<'_>| {
                     let func = $f;
                     // SAFETY: This is the same type as the `value` field.