simplifying get_stack

Author: Dave Huseby

src/libstd/sys/unix/stack_overflow.rs

@@ -135,27 +135,7 @@ mod imp {
         Handler { _data: MAIN_ALTSTACK };
     }
 
-    #[cfg(any(target_os = "linux",
-              target_os = "macos",
-              target_os = "bitrig",
-              target_os = "netbsd",
-              target_os = "openbsd"))]
-    unsafe fn get_stack() -> libc::stack_t {
-        let stackp = mmap(ptr::null_mut(),
-                          SIGSTKSZ,
-                          PROT_READ | PROT_WRITE,
-                          MAP_PRIVATE | MAP_ANON,
-                          -1,
-                          0);
-        if stackp == MAP_FAILED {
-            panic!("failed to allocate an alternative stack");
-        }
-        libc::stack_t { ss_sp: stackp, ss_flags: 0, ss_size: SIGSTKSZ }
-    }
-
-    #[cfg(any(target_os = "dragonfly",
-              target_os = "freebsd"))]
-    unsafe fn get_stack() -> libc::stack_t {
+    unsafe fn get_stack() -> *mut i8 {
         let stackp = mmap(ptr::null_mut(),
                           SIGSTKSZ,
                           PROT_READ | PROT_WRITE,
@@ -165,12 +145,11 @@ mod imp {
         if stackp == MAP_FAILED {
             panic!("failed to allocate an alternative stack");
         }
-        libc::stack_t { ss_sp: stackp as *mut i8, ss_flags: 0, ss_size: SIGSTKSZ }
+        stackp as *mut i8
     }
 
-
     pub unsafe fn make_handler() -> Handler {
-        let stack = get_stack();
+        let stack = libc::stack_t { ss_sp: get_stack(), ss_flags: 0, ss_size: SIGSTKSZ }
         sigaltstack(&stack, ptr::null_mut());
         Handler { _data: stack.ss_sp as *mut libc::c_void }
     }