unify linux and macos into a single module

src/lib.rs

@@ -76,12 +76,8 @@ pub struct Dlmalloc<A = System>(dlmalloc::Dlmalloc<A>);
 #[path = "wasm.rs"]
 mod sys;
 
-#[cfg(target_os = "macos")]
-#[path = "macos.rs"]
-mod sys;
-
-#[cfg(target_os = "linux")]
-#[path = "linux.rs"]
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+#[path = "unix.rs"]
 mod sys;
 
 #[cfg(not(any(target_os = "linux", target_os = "macos", target_arch = "wasm32")))]

src/linux.rs → src/unix.rs

@@ -24,7 +24,7 @@ unsafe impl Allocator for System {
                 0 as *mut _,
                 size,
                 libc::PROT_WRITE | libc::PROT_READ,
-                libc::MAP_ANONYMOUS | libc::MAP_PRIVATE,
+                libc::MAP_ANON | libc::MAP_PRIVATE,
                 -1,
                 0,
             )
@@ -36,6 +36,7 @@ unsafe impl Allocator for System {
         }
     }
 
+    #[cfg(target_os = "linux")]
     fn remap(&self, ptr: *mut u8, oldsize: usize, newsize: usize, can_move: bool) -> *mut u8 {
         let flags = if can_move { libc::MREMAP_MAYMOVE } else { 0 };
         let ptr = unsafe { libc::mremap(ptr as *mut _, oldsize, newsize, flags) };
@@ -46,6 +47,12 @@ unsafe impl Allocator for System {
         }
     }
 
+    #[cfg(target_os = "macos")]
+    fn remap(&self, _ptr: *mut u8, _oldsize: usize, _newsize: usize, _can_move: bool) -> *mut u8 {
+        ptr::null_mut()
+    }
+
+    #[cfg(target_os = "linux")]
     fn free_part(&self, ptr: *mut u8, oldsize: usize, newsize: usize) -> bool {
         unsafe {
             let rc = libc::mremap(ptr as *mut _, oldsize, newsize, 0);
@@ -56,6 +63,11 @@ unsafe impl Allocator for System {
         }
     }
 
+    #[cfg(target_os = "macos")]
+    fn free_part(&self, ptr: *mut u8, oldsize: usize, newsize: usize) -> bool {
+        unsafe { libc::munmap(ptr.offset(newsize as isize) as *mut _, oldsize - newsize) == 0 }
+    }
+
     fn free(&self, ptr: *mut u8, size: usize) -> bool {
         unsafe { libc::munmap(ptr as *mut _, size) == 0 }
     }