Support binding of methods off boxed iface values

Closes rust-lang#435

Author: marijnh

src/rustc/middle/trans/base.rs

@@ -1745,7 +1745,7 @@ type lval_result = {bcx: block, val: ValueRef, kind: lval_kind};
 enum callee_env {
     null_env,
     is_closure,
-    self_env(ValueRef, ty::t),
+    self_env(ValueRef, ty::t, option<ValueRef>),
 }
 type lval_maybe_callee = {bcx: block,
                           val: ValueRef,
@@ -2341,7 +2341,7 @@ fn trans_lval(cx: block, e: @ast::expr) -> lval_result {
 }
 
 fn lval_maybe_callee_to_lval(c: lval_maybe_callee, ty: ty::t) -> lval_result {
-    let must_bind = alt c.env { self_env(_, _) { true } _ { false } };
+    let must_bind = alt c.env { self_env(_, _, _) { true } _ { false } };
     if must_bind {
         let n_args = ty::ty_fn_args(ty).len();
         let args = vec::from_elem(n_args, none);
@@ -2618,7 +2618,7 @@ fn trans_call_inner(in_cx: block, fn_expr_ty: ty::t,
           null_env {
             llvm::LLVMGetUndef(T_opaque_box_ptr(ccx))
           }
-          self_env(e, _) {
+          self_env(e, _, _) {
             PointerCast(bcx, e, T_opaque_box_ptr(ccx))
           }
           is_closure {

src/rustc/middle/trans/closure.rs

@@ -462,8 +462,13 @@ fn trans_bind_1(cx: block, outgoing_fty: ty::t,
         let src_loc = PointerCast(bcx, f_res.val, llclosurety);
         ([env_copy(src_loc, pair_ty, owned)], target_closure)
       }
-      self_env(slf, slf_t) {
-        ([env_copy(slf, slf_t, owned)], target_self(f_res.val))
+      self_env(slf, slf_t, none) {
+        ([env_copy(slf, slf_t, owned)], target_static_self(f_res.val))
+      }
+      self_env(_, slf_t, some(slf)) {
+        let cast = PointerCast(bcx, f_res.val, T_ptr(T_nil()));
+        ([env_copy(cast, ty::mk_nil_ptr(ccx.tcx), owned_imm),
+          env_copy(slf, slf_t, owned_imm)], target_self)
       }
     };
 
@@ -617,7 +622,8 @@ fn make_opaque_cbox_free_glue(
 enum target_info {
     target_closure,
     target_static(ValueRef),
-    target_self(ValueRef),
+    target_self,
+    target_static_self(ValueRef),
 }
 
 // pth is cx.path
@@ -698,7 +704,14 @@ fn trans_bind_thunk(ccx: @crate_ctxt,
             (bcx, GEPi(bcx, pair, [0, abi::fn_field_code]));
         (lltargetfn, lltargetenv, 1)
       }
-      target_self(fptr) {
+      target_self {
+        let fptr = Load(bcx, GEPi(bcx, llcdata,
+                                  [0, abi::closure_body_bindings, 0]));
+        let slfbox = GEPi(bcx, llcdata, [0, abi::closure_body_bindings, 1]);
+        let selfptr = GEPi(bcx, Load(bcx, slfbox), [0, abi::box_field_body]);
+        (fptr, PointerCast(bcx, selfptr, T_opaque_cbox_ptr(ccx)), 2)
+      }
+      target_static_self(fptr) {
         let slfptr = GEPi(bcx, llcdata, [0, abi::closure_body_bindings, 0]);
         (fptr, PointerCast(bcx, slfptr, T_opaque_cbox_ptr(ccx)), 1)
       }

src/rustc/middle/trans/impl.rs

@@ -49,7 +49,7 @@ fn trans_method_callee(bcx: block, callee_id: ast::node_id,
     alt origin {
       typeck::method_static(did) {
         let {bcx, val} = trans_self_arg(bcx, self);
-        {env: self_env(val, node_id_type(bcx, self.id))
+        {env: self_env(val, node_id_type(bcx, self.id), none)
          with lval_static_fn(bcx, did, callee_id)}
       }
       typeck::method_param(iid, off, p, b) {
@@ -115,7 +115,7 @@ fn trans_monomorphized_callee(bcx: block, callee_id: ast::node_id,
         let ty_substs = impl_substs +
             vec::tailn(node_substs, node_substs.len() - n_m_tps);
         let {bcx, val} = trans_self_arg(bcx, base);
-        {env: self_env(val, node_id_type(bcx, base.id))
+        {env: self_env(val, node_id_type(bcx, base.id), none)
          with lval_static_fn_inner(bcx, mth_id, callee_id, ty_substs,
                                    some(sub_origins))}
       }
@@ -138,8 +138,8 @@ fn trans_iface_callee(bcx: block, base: @ast::expr,
     let box = Load(bcx, GEPi(bcx, val, [0, 1]));
     // FIXME[impl] I doubt this is alignment-safe
     let self = GEPi(bcx, box, [0, abi::box_field_body]);
-    trans_vtable_callee(bcx, self_env(self, expr_ty(bcx, base)), vtable,
-                        callee_id, n_method)
+    let env = self_env(self, ty::mk_opaque_box(bcx.tcx()), some(box));
+    trans_vtable_callee(bcx, env, vtable, callee_id, n_method)
 }
 
 fn find_vtable_in_fn_ctxt(ps: param_substs, n_param: uint, n_bound: uint)

src/rustc/middle/ty.rs

@@ -77,7 +77,7 @@ export ty_nil, mk_nil, type_is_nil;
 export ty_iface, mk_iface;
 export ty_res, mk_res;
 export ty_param, mk_param;
-export ty_ptr, mk_ptr, mk_mut_ptr, type_is_unsafe_ptr;
+export ty_ptr, mk_ptr, mk_mut_ptr, mk_nil_ptr, type_is_unsafe_ptr;
 export ty_rptr, mk_rptr;
 export ty_rec, mk_rec;
 export ty_enum, mk_enum, type_is_enum;
@@ -482,6 +482,10 @@ fn mk_rptr(cx: ctxt, r: region, tm: mt) -> t { mk_t(cx, ty_rptr(r, tm)) }
 fn mk_mut_ptr(cx: ctxt, ty: t) -> t { mk_ptr(cx, {ty: ty,
                                                   mutbl: ast::m_mutbl}) }
 
+fn mk_nil_ptr(cx: ctxt) -> t {
+    mk_ptr(cx, {ty: mk_nil(cx), mutbl: ast::m_imm})
+}
+
 fn mk_vec(cx: ctxt, tm: mt) -> t { mk_t(cx, ty_vec(tm)) }
 
 fn mk_rec(cx: ctxt, fs: [field]) -> t { mk_t(cx, ty_rec(fs)) }