Merge branch 'llvm5'

src/wasm.rs

@@ -1,24 +1,18 @@
 use core::ptr;
 
 extern {
-    #[link_name = "llvm.wasm.current.memory.i32"]
-    fn current_memory() -> u32;
-
-    // TODO: this intrinsic actually returns the previous limit, but LLVM
-    // doesn't expose that right now. When we upgrade LLVM stop using
-    // `current_memory` above. Also handle `-1` as an allocation failure.
     #[link_name = "llvm.wasm.grow.memory.i32"]
-    fn grow_memory(pages: u32);
+    fn grow_memory(pages: u32) -> i32;
 }
 
 pub unsafe fn alloc(size: usize) -> (*mut u8, usize, u32) {
     let pages = size / page_size();
-    let cur = current_memory() as usize;
-    grow_memory(pages as u32);
-    if current_memory() as usize == cur {
+    let prev = grow_memory(pages as u32);
+    if prev == -1 {
         return (ptr::null_mut(), 0, 0);
     }
-    ((cur * page_size()) as *mut u8, pages * page_size(), 0)
+    let prev = prev as usize;
+    ((prev * page_size()) as *mut u8, pages * page_size(), 0)
 }
 
 pub unsafe fn remap(_ptr: *mut u8, _oldsize: usize, _newsize: usize, _can_move: bool)