From 652ae9f50e67610b482a2c99360737e1b8e8077b Mon Sep 17 00:00:00 2001
From: Graydon Hoare <graydon@mozilla.com>
Date: Wed, 8 Dec 2010 16:34:16 -0800
Subject: [PATCH] Fix structure returns harder.
---
src/comp/middle/trans.rs | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index e48c693643d..ef0e714369b 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -1403,6 +1403,15 @@ impure fn trans_call(@block_ctxt cx, @ast.expr f,
auto args_res = trans_args(f_res._0.bcx, args, fn_ty);
auto retval = args_res._0.build.FastCall(f_res._0.val, args_res._1);
+ // Structured returns come back as first-class values. This is nice for
+ // LLVM but wrong for us; we treat structured values by pointer in
+ // most of our code here. So spill it to an alloca.
+ if (typeck.type_is_structural(ret_ty)) {
+ auto local = args_res._0.build.Alloca(type_of(cx.fcx.ccx, ret_ty));
+ args_res._0.build.Store(retval, local);
+ retval = local;
+ }
+
// Retval doesn't correspond to anything really tangible in the frame, but
// it's a ref all the same, so we put a note here to drop it when we're
// done in this scope.