SGX target: fix std unit tests

[rust.git] / src / libstd / sys / sgx / abi / usercalls / alloc.rs

diff --git a/src/libstd/sys/sgx/abi/usercalls/alloc.rs b/src/libstd/sys/sgx/abi/usercalls/alloc.rs
index 0ccbbbc65015d0c1fa01e0e12baef64580458bc0..449a5fe5ae3082a837e1f5d7c744e1bb7228c8a3 100644 (file)
--- a/src/libstd/sys/sgx/abi/usercalls/alloc.rs
+++ b/src/libstd/sys/sgx/abi/usercalls/alloc.rs
@@ -1,11 +1,11 @@
 #![allow(unused)]
 
-use ptr::{self, NonNull};
-use mem;
-use cell::UnsafeCell;
-use slice;
-use ops::{Deref, DerefMut, Index, IndexMut, CoerceUnsized};
-use slice::SliceIndex;
+use crate::ptr::{self, NonNull};
+use crate::mem;
+use crate::cell::UnsafeCell;
+use crate::slice;
+use crate::ops::{Deref, DerefMut, Index, IndexMut, CoerceUnsized};
+use crate::slice::SliceIndex;
 
 use fortanix_sgx_abi::*;
 use super::super::mem::is_user_range;
@@ -188,8 +188,13 @@ impl<T: ?Sized> User<T> where T: UserSafe {
     // from outside as obtained by `super::alloc`.
     fn new_uninit_bytes(size: usize) -> Self {
         unsafe {
-            let ptr = super::alloc(size, T::align_of()).expect("User memory allocation failed");
-            User(NonNull::new_userref(T::from_raw_sized(ptr as _, size)))
+            // Mustn't call alloc with size 0.
+            let ptr = if size > 0 {
+                super::alloc(size, T::align_of()).expect("User memory allocation failed") as _
+            } else {
+                T::align_of() as _ // dangling pointer ok for size 0
+            };
+            User(NonNull::new_userref(T::from_raw_sized(ptr, size)))
         }
     }