Take sys/vxworks/alloc from sys/unix instead.

library/std/src/sys/vxworks/alloc.rs

-use crate::alloc::{GlobalAlloc, Layout, System};
-use crate::ptr;
-use crate::sys_common::alloc::{realloc_fallback, MIN_ALIGN};
-
-#[stable(feature = "alloc_system_type", since = "1.28.0")]
-unsafe impl GlobalAlloc for System {
-    #[inline]
-    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
-            libc::malloc(layout.size()) as *mut u8
-        } else {
-            aligned_malloc(&layout)
-        }
-    }
-
-    #[inline]
-    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
-        if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
-            libc::calloc(layout.size(), 1) as *mut u8
-        } else {
-            let ptr = self.alloc(layout.clone());
-            if !ptr.is_null() {
-                ptr::write_bytes(ptr, 0, layout.size());
-            }
-            ptr
-        }
-    }
-
-    #[inline]
-    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
-        libc::free(ptr as *mut libc::c_void)
-    }
-
-    #[inline]
-    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
-        if layout.align() <= MIN_ALIGN && layout.align() <= new_size {
-            libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8
-        } else {
-            realloc_fallback(self, ptr, layout, new_size)
-        }
-    }
-}
-
-#[inline]
-unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
-    let mut out = ptr::null_mut();
-    let ret = libc::posix_memalign(&mut out, layout.align(), layout.size());
-    if ret != 0 { ptr::null_mut() } else { out as *mut u8 }
-}

library/std/src/sys/vxworks/mod.rs

@@ -7,6 +7,7 @@
 pub use crate::os::vxworks as platform;
 pub use libc::strlen;
 
+#[path = "../unix/alloc.rs"]
 pub mod alloc;
 pub mod args;
 pub mod cmath;