Add missing attributes to indirect calls for foreign functions

src/librustc/middle/trans/foreign.rs

@@ -11,7 +11,7 @@
 
 use back::{link};
 use lib::llvm::llvm;
-use lib::llvm::{ValueRef, CallConv, StructRetAttribute, Linkage};
+use lib::llvm::{ValueRef, CallConv, Linkage};
 use lib;
 use middle::weak_lang_items;
 use middle::trans::base::push_ctxt;
@@ -373,18 +373,33 @@ pub fn trans_native_call<'a>(
     };
 
     // 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`.
+    // any attributes with ABI implications directly to the call instruction.
     let mut attrs = Vec::new();
-    if fn_type.ret_ty.is_indirect() {
-        attrs.push((1, lib::llvm::StructRetAttribute as u64));
 
+    // Add attributes that are always applicable, independent of the concrete foreign ABI
+    if fn_type.ret_ty.is_indirect() {
         // The outptr can be noalias and nocapture because it's entirely
         // invisible to the program. We can also mark it as nonnull
         attrs.push((1, lib::llvm::NoAliasAttribute as u64));
         attrs.push((1, lib::llvm::NoCaptureAttribute as u64));
         attrs.push((1, lib::llvm::NonNullAttribute as u64));
     };
+
+    // Add attributes that depend on the concrete foreign ABI
+    let ret_offset = if fn_type.ret_ty.is_indirect() { 1 } else { 0 };
+    match fn_type.ret_ty.attr {
+        Some(attr) => attrs.push((ret_offset, attr as u64)),
+        _ => ()
+    }
+
+    let first_arg_offset = ret_offset + 1;
+    for (idx, &arg_ty) in fn_type.arg_tys.iter().enumerate() {
+        match arg_ty.attr {
+            Some(attr) => attrs.push((first_arg_offset + idx, attr as u64)),
+            _ => {}
+        }
+    }
+
     let llforeign_retval = CallWithConv(bcx,
                                         llfn,
                                         llargs_foreign.as_slice(),

src/rt/rust_test_helpers.c

@@ -199,3 +199,21 @@ void
 rust_dbg_static_mut_check_four() {
     assert(rust_dbg_static_mut == 4);
 }
+
+struct S {
+    uint64_t x;
+    uint64_t y;
+    uint64_t z;
+};
+
+uint64_t get_x(struct S s) {
+    return s.x;
+}
+
+uint64_t get_y(struct S s) {
+    return s.y;
+}
+
+uint64_t get_z(struct S s) {
+    return s.z;
+}

src/test/run-pass/foreign-fn-with-byval.rs

@@ -0,0 +1,36 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub struct S {
+    x: u64,
+    y: u64,
+    z: u64,
+}
+
+#[link(name = "rust_test_helpers")]
+extern {
+    pub fn get_x(x: S) -> u64;
+    pub fn get_y(x: S) -> u64;
+    pub fn get_z(x: S) -> u64;
+}
+
+#[inline(never)]
+fn indirect_call(func: unsafe extern fn(s: S) -> u64, s: S) -> u64 {
+    unsafe {
+        func(s)
+    }
+}
+
+fn main() {
+    let s = S { x: 1, y: 2, z: 3 };
+    assert_eq!(s.x, indirect_call(get_x, s));
+    assert_eq!(s.y, indirect_call(get_y, s));
+    assert_eq!(s.z, indirect_call(get_z, s));
+}