Testing build fixes related to OSX

ci/docker/i686-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:23.10
+#FROM ubuntu:23.10
+FROM ubuntu:24.04
 RUN apt-get update
 RUN apt-get install -y --no-install-recommends \
   gcc-multilib libc6-dev ca-certificates

ci/docker/x86_64-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:23.10
+FROM ubuntu:24.04
 RUN apt-get update
 RUN apt-get install -y --no-install-recommends \
   gcc libc6-dev ca-certificates linux-headers-generic

libc-test/build.rs

@@ -3227,7 +3227,7 @@ fn test_neutrino(target: &str) {
         false // keep me for smaller diffs when something is added above
     });
 
-    cfg.skip_static(move |name| (name == "__dso_handle"));
+    cfg.skip_static(move |name| name == "__dso_handle");
 
     cfg.generate("../src/lib.rs", "main.rs");
 }

src/macros.rs

@@ -191,7 +191,7 @@ cfg_if! {
             })*) => ($(
                 #[inline]
                 $(#[$attr])*
-                pub $($constness)* unsafe extern fn $i($($arg: $argty),*
+                pub $($constness)* unsafe extern "C" fn $i($($arg: $argty),*
                 ) -> $ret {
                     $($body);*
                 }
@@ -206,7 +206,7 @@ cfg_if! {
             })*) => ($(
                 #[inline]
                 $(#[$attr])*
-                pub $($constness)* extern fn $i($($arg: $argty),*
+                pub $($constness)* extern "C" fn $i($($arg: $argty),*
                 ) -> $ret {
                     $($body);*
                 }
@@ -237,7 +237,7 @@ cfg_if! {
             })*) => ($(
                 #[inline]
                 $(#[$attr])*
-                pub unsafe extern fn $i($($arg: $argty),*
+                pub unsafe extern "C" fn $i($($arg: $argty),*
                 ) -> $ret {
                     $($body);*
                 }
@@ -252,7 +252,7 @@ cfg_if! {
             })*) => ($(
                 #[inline]
                 $(#[$attr])*
-                pub extern fn $i($($arg: $argty),*
+                pub extern "C" fn $i($($arg: $argty),*
                 ) -> $ret {
                     $($body);*
                 }

src/unix/bsd/apple/b64/x86_64/mod.rs

@@ -1,3 +1,5 @@
+#![allow(unpredictable_function_pointer_comparisons)]
+
 pub type boolean_t = ::c_uint;
 pub type mcontext_t = *mut __darwin_mcontext64;
 

src/unix/linux_like/linux/gnu/b32/arm/mod.rs

@@ -6,7 +6,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b32/csky/mod.rs

@@ -6,7 +6,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b32/m68k/mod.rs

@@ -6,7 +6,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b32/mips/mod.rs

@@ -75,7 +75,7 @@ s! {
         pub sa_flags: ::c_int,
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
         _resv: [::c_int; 1],
     }
 

src/unix/linux_like/linux/gnu/b32/mod.rs

@@ -1,4 +1,5 @@
 //! 32-bit specific definitions for linux-like values
+#![allow(unpredictable_function_pointer_comparisons)]
 
 use pthread_mutex_t;
 

src/unix/linux_like/linux/gnu/b32/powerpc.rs

@@ -6,7 +6,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b32/sparc/mod.rs

@@ -8,7 +8,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b32/x86/mod.rs

@@ -7,7 +7,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b64/aarch64/mod.rs

@@ -15,7 +15,7 @@ s! {
         #[cfg(target_arch = "sparc64")]
         __reserved0: ::c_int,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b64/loongarch64/mod.rs

@@ -140,7 +140,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct stack_t {

src/unix/linux_like/linux/gnu/b64/mips64/mod.rs

@@ -142,7 +142,7 @@ s! {
         pub sa_flags: ::c_int,
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct stack_t {

src/unix/linux_like/linux/gnu/b64/powerpc64/mod.rs

@@ -19,7 +19,7 @@ s! {
         #[cfg(target_arch = "sparc64")]
         __reserved0: ::c_int,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b64/s390x.rs

@@ -18,7 +18,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         __glibc_reserved0: ::c_int,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
         pub sa_mask: ::sigset_t,
     }
 

src/unix/linux_like/linux/gnu/b64/sparc64/mod.rs

@@ -19,7 +19,7 @@ s! {
         #[cfg(target_arch = "sparc64")]
         __reserved0: ::c_int,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/b64/x86_64/mod.rs

@@ -1,4 +1,5 @@
 //! x86_64-specific definitions for 64-bit linux-like values
+#![allow(unpredictable_function_pointer_comparisons)]
 
 pub type c_char = i8;
 pub type wchar_t = i32;
@@ -16,7 +17,7 @@ s! {
         #[cfg(target_arch = "sparc64")]
         __reserved0: ::c_int,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statfs {

src/unix/linux_like/linux/gnu/mod.rs

@@ -400,6 +400,7 @@ s! {
         pub chunk_size: ::__u32,
         pub headroom: ::__u32,
         pub flags: ::__u32,
+        pub tx_metadata_len: ::__u32,
     }
 
     pub struct xdp_umem_reg_v1 {

src/unix/linux_like/linux/musl/mod.rs

@@ -145,7 +145,7 @@ s! {
         pub sa_sigaction: ::sighandler_t,
         pub sa_mask: ::sigset_t,
         pub sa_flags: ::c_int,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
     }
 
     pub struct statvfs {

src/unix/linux_like/linux/uclibc/arm/mod.rs

@@ -167,7 +167,7 @@ s! {
     pub struct sigaction {
         pub sa_sigaction: ::sighandler_t,
         pub sa_flags: ::c_ulong,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
         pub sa_mask: sigset_t,
     }
 

src/unix/linux_like/linux/uclibc/x86_64/mod.rs

@@ -146,7 +146,7 @@ s! {
     pub struct sigaction {
         pub sa_handler: ::sighandler_t,
         pub sa_flags: ::c_ulong,
-        pub sa_restorer: ::Option<extern fn()>,
+        pub sa_restorer: ::Option<extern "C" fn()>,
         pub sa_mask: ::sigset_t,
     }
 

src/unix/mod.rs

@@ -346,25 +346,25 @@ cfg_if! {
         #[link(name = "m", cfg(not(target_feature = "crt-static")))]
         #[link(name = "dl", cfg(not(target_feature = "crt-static")))]
         #[link(name = "c", cfg(not(target_feature = "crt-static")))]
-        extern {}
+        extern "C" {}
     } else if #[cfg(any(target_env = "musl", target_env = "ohos"))] {
         #[cfg_attr(feature = "rustc-dep-of-std",
                    link(name = "c", kind = "static", modifiers = "-bundle",
                         cfg(target_feature = "crt-static")))]
         #[cfg_attr(feature = "rustc-dep-of-std",
                    link(name = "c", cfg(not(target_feature = "crt-static"))))]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_os = "emscripten")] {
         #[link(name = "c")]
-        extern {}
+        extern "C" {}
     } else if #[cfg(all(target_os = "android", feature = "rustc-dep-of-std"))] {
         #[link(name = "c", kind = "static", modifiers = "-bundle",
             cfg(target_feature = "crt-static"))]
         #[link(name = "m", kind = "static", modifiers = "-bundle",
             cfg(target_feature = "crt-static"))]
         #[link(name = "m", cfg(not(target_feature = "crt-static")))]
         #[link(name = "c", cfg(not(target_feature = "crt-static")))]
-        extern {}
+        extern "C" {}
     } else if #[cfg(any(target_os = "macos",
                         target_os = "ios",
                         target_os = "tvos",
@@ -376,38 +376,38 @@ cfg_if! {
                     ))] {
         #[link(name = "c")]
         #[link(name = "m")]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_os = "haiku")] {
         #[link(name = "root")]
         #[link(name = "network")]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_env = "newlib")] {
         #[link(name = "c")]
         #[link(name = "m")]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_env = "illumos")] {
         #[link(name = "c")]
         #[link(name = "m")]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_os = "redox")] {
         #[cfg_attr(feature = "rustc-dep-of-std",
                    link(name = "c", kind = "static", modifiers = "-bundle",
                         cfg(target_feature = "crt-static")))]
         #[cfg_attr(feature = "rustc-dep-of-std",
                    link(name = "c", cfg(not(target_feature = "crt-static"))))]
-        extern {}
+        extern "C" {}
     } else if #[cfg(target_os = "aix")] {
         #[link(name = "c")]
         #[link(name = "m")]
         #[link(name = "bsd")]
         #[link(name = "pthread")]
-        extern {}
+        extern "C" {}
     } else {
         #[link(name = "c")]
         #[link(name = "m")]
         #[link(name = "rt")]
         #[link(name = "pthread")]
-        extern {}
+        extern "C" {}
     }
 }
 
@@ -1444,7 +1444,7 @@ cfg_if! {
 
 cfg_if! {
     if #[cfg(not(target_os = "redox"))] {
-        extern {
+        extern "C" {
             pub fn getsid(pid: pid_t) -> pid_t;
             #[cfg_attr(all(target_os = "macos", target_arch = "x86"),
                        link_name = "pause$UNIX2003")]
@@ -1483,7 +1483,7 @@ cfg_if! {
 
 cfg_if! {
     if #[cfg(target_os = "nto")] {
-        extern {
+        extern "C" {
             pub fn readlinkat(dirfd: ::c_int,
                 pathname: *const ::c_char,
                 buf: *mut ::c_char,
@@ -1504,7 +1504,7 @@ cfg_if! {
             ) -> ::c_int;
         }
     } else {
-        extern {
+        extern "C" {
             pub fn readlinkat(dirfd: ::c_int,
                 pathname: *const ::c_char,
                 buf: *mut ::c_char,
@@ -1545,7 +1545,7 @@ cfg_if! {
                     target_os = "illumos",
                     target_os = "nto",
                 )))] {
-        extern {
+        extern "C" {
             pub fn cfmakeraw(termios: *mut ::termios);
             pub fn cfsetspeed(termios: *mut ::termios,
                               speed: ::speed_t) -> ::c_int;