---

yaml
---
r: 80583
b: refs/heads/auto
c: 22b6f74
h: refs/heads/master
i:
  80581: 2cec316
  80579: b6b6de7
  80575: fb5dcc2
v: v3

Author: thestinger

[refs]

@@ -13,7 +13,7 @@ refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0
 refs/tags/release-0.3.1: 495bae036dfe5ec6ceafd3312b4dca48741e845b
 refs/tags/release-0.4: e828ea2080499553b97dfe33b3f4d472b4562ad7
 refs/tags/release-0.5: 7e3bcfbf21278251ee936ad53e92e9b719702d73
-refs/heads/auto: b2eb1c01a45cbb7bfc40f24073b60de61e3fad47
+refs/heads/auto: 22b6f7481f592babf2b4e230120597c47750dae1
 refs/heads/servo: af82457af293e2a842ba6b7759b70288da276167
 refs/tags/release-0.6: b4ebcfa1812664df5e142f0134a5faea3918544c
 refs/tags/0.1: b19db808c2793fe2976759b85a355c3ad8c8b336

branches/auto/src/librustc/middle/trans/callee.rs

@@ -706,12 +706,15 @@ pub fn trans_call_inner(in_cx: @mut Block,
                 _ => {}
             }
 
-            // Invoke the actual rust fn and update bcx/llresult.
+            // A function pointer is called without the declaration available, so we have to apply
+            // any attributes with ABI implications directly to the call instruction. Right now, the
+            // only attribute we need to worry about is `sret`.
             let mut attrs = ~[];
             if type_of::return_uses_outptr(in_cx.tcx(), ret_ty) {
                 attrs.push((1, StructRetAttribute));
             }
 
+            // The `noalias` attribute on the return value is useful to a function ptr caller.
             match ty::get(ret_ty).sty {
                 // `~` pointer return values never alias because ownership is transferred
                 ty::ty_uniq(*) |
@@ -721,6 +724,7 @@ pub fn trans_call_inner(in_cx: @mut Block,
                 _ => ()
             }
 
+            // Invoke the actual rust fn and update bcx/llresult.
             let (llret, b) = base::invoke(bcx, llfn, llargs, attrs);
             bcx = b;
             llresult = llret;

branches/auto/src/librustc/middle/trans/foreign.rs

@@ -264,6 +264,9 @@ pub fn trans_native_call(bcx: @mut Block,
         }
     };
 
+    // A function pointer is called without the declaration available, so we have to apply
+    // any attributes with ABI implications directly to the call instruction. Right now, the
+    // only attribute we need to worry about is `sret`.
     let attrs;
     if fn_type.sret {
         attrs = &[(1, StructRetAttribute)];