Implement black box inside test file

Author: oli-obk

src/arch/i686.S

@@ -6,9 +6,6 @@ GLOBAL(__stacker_stack_pointer):
     mov %esp, %eax
     ret
 
-GLOBAL(__stacker_black_box):
-    ret
-
 GLOBAL(__stacker_switch_stacks):
     // CFI instructions tells the unwinder how to unwind this function
     // This enables unwinding through our extended stacks and also

src/arch/windows.c

@@ -1,7 +1,5 @@
 #include <windows.h>
 
-void __stacker_black_box() {}
-
 PVOID __stacker_get_current_fiber() {
     return GetCurrentFiber();
 }

src/arch/x86_64.S

@@ -2,8 +2,6 @@
 
 .text
 
-GLOBAL(__stacker_black_box):
-    ret
 GLOBAL(__stacker_stack_pointer):
     movq %rsp, %rax
     ret

tests/smoke.rs

@@ -3,19 +3,18 @@ extern crate stacker;
 use std::sync::mpsc;
 use std::thread;
 
-extern {
-    fn __stacker_black_box(t: *const u8);
-}
+#[inline(never)]
+fn __stacker_black_box(_: *const u8) {}
 
 #[test]
 fn deep() {
     fn foo(n: usize, s: &mut [u8]) {
-        unsafe { __stacker_black_box(s.as_ptr()); }
+        __stacker_black_box(s.as_ptr());
         if n > 0 {
             stacker::maybe_grow(64 * 1024, 1024 * 1024, || {
                 let mut s = [0u8; 1024];
                 foo(n - 1, &mut s);
-                unsafe { __stacker_black_box(s.as_ptr()); }
+                __stacker_black_box(s.as_ptr());
             })
         } else {
             println!("bottom");
@@ -28,12 +27,12 @@ fn deep() {
 #[test]
 fn panic() {
     fn foo(n: usize, s: &mut [u8]) {
-        unsafe { __stacker_black_box(s.as_ptr()); }
+        __stacker_black_box(s.as_ptr());
         if n > 0 {
             stacker::maybe_grow(64 * 1024, 1024 * 1024, || {
                 let mut s = [0u8; 1024];
                 foo(n - 1, &mut s);
-                unsafe { __stacker_black_box(s.as_ptr()); }
+                __stacker_black_box(s.as_ptr());
             })
         } else {
             panic!("bottom");
@@ -84,4 +83,4 @@ fn catch_panic_leaf() {
         let panic_result = std::panic::catch_unwind(|| panic!());
         assert!(panic_result.is_err());
     });
-}
+}