---

yaml
---
r: 107993
b: refs/heads/dist-snap
c: 2bf575c
h: refs/heads/master
i:
  107991: 7dc3610
v: v3

Author: bors

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: f64fdf524a434f0e5cd0bc91d09c144723f3c90d
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c
-refs/heads/dist-snap: dd21a51d294ad9843d61b7f2016957a279b0d64f
+refs/heads/dist-snap: 2bf575c86fd3c053df83b90862441fec71c7a622
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503
 refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0

branches/dist-snap/src/librustc/middle/trans/glue.rs

@@ -30,7 +30,7 @@ use middle::trans::machine::*;
 use middle::trans::reflect;
 use middle::trans::tvec;
 use middle::trans::type_::Type;
-use middle::trans::type_of::type_of;
+use middle::trans::type_of::{type_of, sizing_type_of};
 use middle::ty;
 use util::ppaux::ty_to_short_str;
 use util::ppaux;
@@ -100,23 +100,29 @@ pub fn lazily_emit_all_tydesc_glue(ccx: @CrateContext,
     lazily_emit_tydesc_glue(ccx, abi::tydesc_field_visit_glue, static_ti);
 }
 
-fn simplified_glue_type(tcx: ty::ctxt, field: uint, t: ty::t) -> ty::t {
+fn get_glue_type(ccx: &CrateContext, field: uint, t: ty::t) -> ty::t {
+    let tcx = ccx.tcx;
     if field == abi::tydesc_field_drop_glue {
         if !ty::type_needs_drop(tcx, t) {
-            return ty::mk_nil();
+            return ty::mk_i8();
         }
         match ty::get(t).sty {
-            ty::ty_box(typ)
-                if !ty::type_needs_drop(tcx, typ) =>
-            return ty::mk_box(tcx, ty::mk_nil()),
-
-            ty::ty_uniq(typ)
-                if !ty::type_needs_drop(tcx, typ) =>
-            return ty::mk_uniq(tcx, ty::mk_nil()),
+            ty::ty_box(typ) if !ty::type_needs_drop(tcx, typ) =>
+                return ty::mk_box(tcx, ty::mk_i8()),
+
+            ty::ty_uniq(typ) if !ty::type_needs_drop(tcx, typ) => {
+                let llty = sizing_type_of(ccx, typ);
+                // Unique boxes do not allocate for zero-size types. The standard library may assume
+                // that `free` is never called on the pointer returned for `~ZeroSizeType`.
+                if llsize_of_alloc(ccx, llty) == 0 {
+                    return ty::mk_i8();
+                } else {
+                    return ty::mk_uniq(tcx, ty::mk_i8());
+                }
+            }
 
-            ty::ty_vec(mt, ty::vstore_uniq)
-                if !ty::type_needs_drop(tcx, mt.ty) =>
-            return ty::mk_uniq(tcx, ty::mk_nil()),
+            ty::ty_vec(mt, ty::vstore_uniq) if !ty::type_needs_drop(tcx, mt.ty) =>
+                return ty::mk_uniq(tcx, ty::mk_i8()),
 
             _ => {}
         }
@@ -128,7 +134,7 @@ fn simplified_glue_type(tcx: ty::ctxt, field: uint, t: ty::t) -> ty::t {
 pub fn lazily_emit_tydesc_glue(ccx: @CrateContext, field: uint, ti: @tydesc_info) {
     let _icx = push_ctxt("lazily_emit_tydesc_glue");
 
-    let simpl = simplified_glue_type(ccx.tcx, field, ti.ty);
+    let simpl = get_glue_type(ccx, field, ti.ty);
     if simpl != ti.ty {
         let _icx = push_ctxt("lazily_emit_simplified_tydesc_glue");
         let simpl_ti = get_tydesc(ccx, simpl);
@@ -204,7 +210,7 @@ pub fn call_tydesc_glue_full(bcx: &Block, v: ValueRef, tydesc: ValueRef,
         PointerCast(bcx, v, Type::i8p())
     } else {
         let ty = static_ti.unwrap().ty;
-        let simpl = simplified_glue_type(ccx.tcx, field, ty);
+        let simpl = get_glue_type(ccx, field, ty);
         if simpl != ty {
             PointerCast(bcx, v, type_of(ccx, simpl).ptr_to())
         } else {