From 1cfcb243b3a453afe809205bbcba0a0a1e2a2936 Mon Sep 17 00:00:00 2001
From: "Pablo@XPS-13" <pablo.adames@protonmail.com>
Date: Fri, 27 Mar 2026 23:37:06 -0600
Subject: [PATCH] fix. Rustc 1.89.9 (28483883e 2025-08-94) requires new
 asm/naked function syntax

---
 ch05/c-fibers/src/main.rs | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/ch05/c-fibers/src/main.rs b/ch05/c-fibers/src/main.rs
index ea31501..3bde1eb 100644
--- a/ch05/c-fibers/src/main.rs
+++ b/ch05/c-fibers/src/main.rs
@@ -1,5 +1,6 @@
-#![feature(naked_functions)]
+//#![feature(naked_functions)]
 use std::arch::asm;
+use std::arch::naked_asm;
 
 const DEFAULT_STACK_SIZE: usize = 1024 * 1024 * 2;
 const MAX_THREADS: usize = 4;
@@ -139,9 +140,10 @@ fn guard() {
     };
 }
 
-#[naked]
+#[unsafe(naked)]
 unsafe extern "C" fn skip() {
-    asm!("ret", options(noreturn))
+    //naked_asm!("ret", options(noreturn))
+    naked_asm!("ret")
 }
 
 pub fn yield_thread() {
@@ -151,11 +153,11 @@ pub fn yield_thread() {
     };
 }
 
-#[naked]
+#[unsafe(naked)]
 #[no_mangle]
 #[cfg_attr(target_os = "macos", export_name = "\x01switch")] // see: How-to-MacOS-M.md for explanation
 unsafe extern "C" fn switch() {
-    asm!(
+    naked_asm!(
         "mov [rdi + 0x00], rsp",
         "mov [rdi + 0x08], r15",
         "mov [rdi + 0x10], r14",
@@ -171,7 +173,7 @@ unsafe extern "C" fn switch() {
         "mov rbx, [rsi + 0x28]",
         "mov rbp, [rsi + 0x30]",
         "ret",
-        options(noreturn)
+//        options(noreturn)
     );
 }