Auto merge of #2132 - JohnTitor:cmsg-space, r=Amanieu

Constify `CMSG_SPACE` for all the targets

`CMSG_SPACE` is a const fn for Linux but it isn't for other targets. This constifies it on all the targets for consistency.

Fixes #2087

Author: bors

src/fuchsia/mod.rs

@@ -3256,12 +3256,12 @@ f! {
         }
     }
 
-    pub fn CMSG_ALIGN(len: ::size_t) -> ::size_t {
+    pub {const} fn CMSG_ALIGN(len: ::size_t) -> ::size_t {
         (len + ::mem::size_of::<::size_t>() - 1)
             & !(::mem::size_of::<::size_t>() - 1)
     }
 
-    pub fn CMSG_SPACE(len: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(len: ::c_uint) -> ::c_uint {
         (CMSG_ALIGN(len as ::size_t) + CMSG_ALIGN(::mem::size_of::<cmsghdr>()))
             as ::c_uint
     }

src/unix/bsd/apple/mod.rs

@@ -3366,7 +3366,12 @@ pub const MNT_WAIT: ::c_int = 1;
 pub const MNT_NOWAIT: ::c_int = 2;
 
 cfg_if! {
-    if #[cfg(libc_const_size_of)] {
+    if #[cfg(libc_const_extern_fn)] {
+        const fn __DARWIN_ALIGN32(p: usize) -> usize {
+            const __DARWIN_ALIGNBYTES32: usize = ::mem::size_of::<u32>() - 1;
+            p + __DARWIN_ALIGNBYTES32 & !__DARWIN_ALIGNBYTES32
+        }
+    } else if #[cfg(libc_const_size_of)] {
         fn __DARWIN_ALIGN32(p: usize) -> usize {
             const __DARWIN_ALIGNBYTES32: usize = ::mem::size_of::<u32>() - 1;
             p + __DARWIN_ALIGNBYTES32 & !__DARWIN_ALIGNBYTES32
@@ -3388,7 +3393,7 @@ f! {
         let cmsg_len = (*cmsg).cmsg_len as usize;
         let next = cmsg as usize + __DARWIN_ALIGN32(cmsg_len as usize);
         let max = (*mhdr).msg_control as usize
-                   + (*mhdr).msg_controllen as usize;
+                    + (*mhdr).msg_controllen as usize;
         if next + __DARWIN_ALIGN32(::mem::size_of::<::cmsghdr>()) > max {
             0 as *mut ::cmsghdr
         } else {
@@ -3401,7 +3406,7 @@ f! {
             .offset(__DARWIN_ALIGN32(::mem::size_of::<::cmsghdr>()) as isize)
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (__DARWIN_ALIGN32(::mem::size_of::<::cmsghdr>())
             + __DARWIN_ALIGN32(length as usize))
             as ::c_uint

src/unix/bsd/freebsdlike/dragonfly/mod.rs

@@ -1020,8 +1020,10 @@ pub const SF_XLINK: ::c_ulong = 0x01000000;
 pub const UTIME_OMIT: c_long = -2;
 pub const UTIME_NOW: c_long = -1;
 
-fn _CMSG_ALIGN(n: usize) -> usize {
-    (n + 3) & !3
+const_fn! {
+    {const} fn _CMSG_ALIGN(n: usize) -> usize {
+        (n + 3) & !3
+    }
 }
 
 f! {
@@ -1050,7 +1052,7 @@ f! {
         }
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (_CMSG_ALIGN(::mem::size_of::<::cmsghdr>()) +
             _CMSG_ALIGN(length as usize)) as ::c_uint
     }

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -1216,8 +1216,10 @@ pub const F_READAHEAD: ::c_int = 15;
 pub const F_RDAHEAD: ::c_int = 16;
 pub const F_DUP2FD_CLOEXEC: ::c_int = 18;
 
-fn _ALIGN(p: usize) -> usize {
-    (p + _ALIGNBYTES) & !_ALIGNBYTES
+const_fn! {
+    {const} fn _ALIGN(p: usize) -> usize {
+        (p + _ALIGNBYTES) & !_ALIGNBYTES
+    }
 }
 
 f! {
@@ -1248,7 +1250,7 @@ f! {
         }
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (_ALIGN(::mem::size_of::<::cmsghdr>()) + _ALIGN(length as usize))
             as ::c_uint
     }

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -1748,8 +1748,10 @@ pub const SF_SNAPSHOT: ::c_ulong = 0x00200000;
 pub const SF_LOG: ::c_ulong = 0x00400000;
 pub const SF_SNAPINVAL: ::c_ulong = 0x00800000;
 
-fn _ALIGN(p: usize) -> usize {
-    (p + _ALIGNBYTES) & !_ALIGNBYTES
+const_fn! {
+    {const} fn _ALIGN(p: usize) -> usize {
+        (p + _ALIGNBYTES) & !_ALIGNBYTES
+    }
 }
 
 f! {
@@ -1780,7 +1782,7 @@ f! {
         }
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (_ALIGN(::mem::size_of::<::cmsghdr>()) + _ALIGN(length as usize))
             as ::c_uint
     }

src/unix/bsd/netbsdlike/openbsd/mod.rs

@@ -1397,8 +1397,10 @@ pub const PTRACE_FORK: ::c_int = 0x0002;
 
 pub const WCONTINUED: ::c_int = 8;
 
-fn _ALIGN(p: usize) -> usize {
-    (p + _ALIGNBYTES) & !_ALIGNBYTES
+const_fn! {
+    {const} fn _ALIGN(p: usize) -> usize {
+        (p + _ALIGNBYTES) & !_ALIGNBYTES
+    }
 }
 
 f! {
@@ -1429,7 +1431,7 @@ f! {
         }
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (_ALIGN(::mem::size_of::<::cmsghdr>()) + _ALIGN(length as usize))
             as ::c_uint
     }

src/unix/solarish/mod.rs

@@ -2103,12 +2103,14 @@ const _CMSG_HDR_ALIGNMENT: usize = 4;
 
 const _CMSG_DATA_ALIGNMENT: usize = ::mem::size_of::<::c_int>();
 
-fn _CMSG_HDR_ALIGN(p: usize) -> usize {
-    (p + _CMSG_HDR_ALIGNMENT - 1) & !(_CMSG_HDR_ALIGNMENT - 1)
-}
+const_fn! {
+    {const} fn _CMSG_HDR_ALIGN(p: usize) -> usize {
+        (p + _CMSG_HDR_ALIGNMENT - 1) & !(_CMSG_HDR_ALIGNMENT - 1)
+    }
 
-fn _CMSG_DATA_ALIGN(p: usize) -> usize {
-    (p + _CMSG_DATA_ALIGNMENT - 1) & !(_CMSG_DATA_ALIGNMENT - 1)
+    {const} fn _CMSG_DATA_ALIGN(p: usize) -> usize {
+        (p + _CMSG_DATA_ALIGNMENT - 1) & !(_CMSG_DATA_ALIGNMENT - 1)
+    }
 }
 
 f! {
@@ -2146,7 +2148,7 @@ f! {
         }
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         _CMSG_HDR_ALIGN(::mem::size_of::<::cmsghdr>() as usize
             + length as usize) as ::c_uint
     }

src/vxworks/mod.rs

@@ -1040,7 +1040,7 @@ impl ::Clone for fpos_t {
 }
 
 f! {
-    pub fn CMSG_ALIGN(len: usize) -> usize {
+    pub {const} fn CMSG_ALIGN(len: usize) -> usize {
         len + ::mem::size_of::<usize>() - 1 & !(::mem::size_of::<usize>() - 1)
     }
 
@@ -1071,7 +1071,7 @@ f! {
             .offset(CMSG_ALIGN(::mem::size_of::<::cmsghdr>()) as isize)
     }
 
-    pub fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
+    pub {const} fn CMSG_SPACE(length: ::c_uint) -> ::c_uint {
         (CMSG_ALIGN(length as usize) + CMSG_ALIGN(::mem::size_of::<cmsghdr>()))
             as ::c_uint
     }