Use the right type for self in methods and remove obsoleted items.

Fixes #7411, #10615.

28 files changed, 472 insertions, 522 deletions

diff --git a/src/librustc/metadata/tydecode.rs b/src/librustc/metadata/tydecode.rs
index 1057340cf58..261cb15a7aa 100644
--- a/src/librustc/metadata/tydecode.rs
+++ b/src/librustc/metadata/tydecode.rs
@@ -410,7 +410,6 @@ fn parse_ty(st: &mut PState, conv: conv_did) -> ty::t {
         let inner = parse_ty(st, |x,y| conv(x,y));
         inner
       }
-      'B' => ty::mk_opaque_box(st.tcx),
       'a' => {
           assert_eq!(next(st), '[');
           let did = parse_def(st, NominalType, |x,y| conv(x,y));
diff --git a/src/librustc/metadata/tyencode.rs b/src/librustc/metadata/tyencode.rs
index dc61c6d4391..8a8fdd72652 100644
--- a/src/librustc/metadata/tyencode.rs
+++ b/src/librustc/metadata/tyencode.rs
@@ -331,7 +331,6 @@ fn enc_sty(w: &mut MemWriter, cx: @ctxt, st: &ty::sty) {
             mywrite!(w, "C&");
             enc_sigil(w, p);
         }
-        ty::ty_opaque_box => mywrite!(w, "B"),
         ty::ty_struct(def, ref substs) => {
             mywrite!(w, "a[{}|", (cx.ds)(def));
             enc_substs(w, cx, substs);
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index 9541afe719b..675d31ebea8 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -578,9 +578,6 @@ fn encode_method_map_entry(ecx: &e::EncodeContext,
         ebml_w.emit_struct_field("origin", 1u, |ebml_w| {
             mme.origin.encode(ebml_w);
         });
-        ebml_w.emit_struct_field("self_mode", 3, |ebml_w| {
-            mme.self_mode.encode(ebml_w);
-        });
     })
 }
 
@@ -602,11 +599,7 @@ impl<'a> read_method_map_entry_helper for reader::Decoder<'a> {
                     let method_origin: method_origin =
                         Decodable::decode(this);
                     method_origin.tr(xcx)
-                }),
-                self_mode: this.read_struct_field("self_mode", 3, |this| {
-                    let self_mode: ty::SelfMode = Decodable::decode(this);
-                    self_mode
-                }),
+                })
             }
         })
     }
diff --git a/src/librustc/middle/trans/_match.rs b/src/librustc/middle/trans/_match.rs
index 07f8bba4464..29c82ef83f8 100644
--- a/src/librustc/middle/trans/_match.rs
+++ b/src/librustc/middle/trans/_match.rs
@@ -1392,37 +1392,41 @@ fn insert_lllocals<'a>(
         let llval = match binding_info.trmode {
             // By value bindings: use the stack slot that we
             // copied/moved the value into
-            TrByValue(lldest) => {
-                if add_cleans {
-                    add_clean(bcx, lldest, binding_info.ty);
-                }
+            TrByValue(lldest) => lldest,
+            // By ref binding: use the ptr into the matched value
+            TrByRef => binding_info.llmatch
+        };
 
-                lldest
-            }
+        let datum = Datum {
+            val: llval,
+            ty: binding_info.ty,
+            mode: ByRef(ZeroMem)
+        };
 
-            // By ref binding: use the ptr into the matched value
-            TrByRef => {
-                binding_info.llmatch
+        if add_cleans {
+            match binding_info.trmode {
+                TrByValue(_) => datum.add_clean(bcx),
+                _ => {}
             }
-        };
+        }
 
         {
             debug!("binding {:?} to {}",
                    binding_info.id,
                    bcx.val_to_str(llval));
             let mut llmap = bcx.fcx.lllocals.borrow_mut();
-            llmap.get().insert(binding_info.id, llval);
+            llmap.get().insert(binding_info.id, datum);
         }
 
         if bcx.sess().opts.extra_debuginfo {
             debuginfo::create_match_binding_metadata(bcx,
                                                      ident,
                                                      binding_info.id,
-                                                     binding_info.ty,
-                                                     binding_info.span);
+                                                     binding_info.span,
+                                                     datum);
         }
     }
-    return bcx;
+    bcx
 }
 
 fn compile_guard<'r,
@@ -2032,8 +2036,7 @@ pub fn store_local<'a>(
                 Some(path) => {
                     return mk_binding_alloca(
                         bcx, pat.id, path, BindLocal,
-                        |bcx, _, llval| expr::trans_into(bcx, init_expr,
-                                                         expr::SaveIn(llval)));
+                        |bcx, datum| expr::trans_into(bcx, init_expr, expr::SaveIn(datum.val)));
                 }
 
                 None => {}
@@ -2067,13 +2070,13 @@ pub fn store_local<'a>(
         pat_bindings(tcx.def_map, pat, |_, p_id, _, path| {
             bcx = mk_binding_alloca(
                 bcx, p_id, path, BindLocal,
-                |bcx, var_ty, llval| { zero_mem(bcx, llval, var_ty); bcx });
+                |bcx, datum| { datum.cancel_clean(bcx); bcx });
         });
         bcx
     }
 }
 
-pub fn store_arg<'a>(mut bcx: &'a Block<'a>, pat: @ast::Pat, llval: ValueRef)
+pub fn store_arg<'a>(mut bcx: &'a Block<'a>, pat: @ast::Pat, arg: Datum)
                  -> &'a Block<'a> {
     /*!
      * Generates code for argument patterns like `fn foo(<pat>: T)`.
@@ -2093,13 +2096,12 @@ pub fn store_arg<'a>(mut bcx: &'a Block<'a>, pat: @ast::Pat, llval: ValueRef)
     // Note that we cannot do it before for fear of a fn like
     //    fn getaddr(~ref x: ~uint) -> *uint {....}
     // (From test `run-pass/func-arg-ref-pattern.rs`)
-    let arg_ty = node_id_type(bcx, pat.id);
-    add_clean(bcx, llval, arg_ty);
+    arg.add_clean(bcx);
 
     // Debug information (the llvm.dbg.declare intrinsic to be precise) always expects to get an
     // alloca, which only is the case on the general path, so lets disable the optimized path when
     // debug info is enabled.
-    let arg_is_alloca = unsafe { llvm::LLVMIsAAllocaInst(llval) != ptr::null() };
+    let arg_is_alloca = unsafe { llvm::LLVMIsAAllocaInst(arg.val) != ptr::null() };
 
     let fast_path = (arg_is_alloca || !bcx.ccx().sess.opts.extra_debuginfo)
                     && simple_identifier(pat).is_some();
@@ -2109,37 +2111,42 @@ pub fn store_arg<'a>(mut bcx: &'a Block<'a>, pat: @ast::Pat, llval: ValueRef)
         // `llval` wholesale as the pointer for `x`, avoiding the
         // general logic which may copy out of `llval`.
         let mut llargs = bcx.fcx.llargs.borrow_mut();
-        llargs.get().insert(pat.id, llval);
+        llargs.get().insert(pat.id, arg);
     } else {
         // General path. Copy out the values that are used in the
         // pattern.
-        bcx = bind_irrefutable_pat(bcx, pat, llval, BindArgument);
+        let llptr = arg.to_ref_llval(bcx);
+        bcx = bind_irrefutable_pat(bcx, pat, llptr, BindArgument);
     }
 
     return bcx;
 }
 
 fn mk_binding_alloca<'a>(
-                     mut bcx: &'a Block<'a>,
+                     bcx: &'a Block<'a>,
                      p_id: ast::NodeId,
                      path: &ast::Path,
                      binding_mode: IrrefutablePatternBindingMode,
-                     populate: |&'a Block<'a>,
-                                ty::t,
-                                ValueRef|
-                                -> &'a Block<'a>)
+                     populate: |&'a Block<'a>, Datum| -> &'a Block<'a>)
                      -> &'a Block<'a> {
     let var_ty = node_id_type(bcx, p_id);
     let ident = ast_util::path_to_ident(path);
     let llval = alloc_ty(bcx, var_ty, bcx.ident(ident));
-    bcx = populate(bcx, var_ty, llval);
-    let mut llmap = match binding_mode {
-        BindLocal => bcx.fcx.lllocals.borrow_mut(),
-        BindArgument => bcx.fcx.llargs.borrow_mut(),
+    let datum = Datum {
+        val: llval,
+        ty: var_ty,
+        mode: ByRef(ZeroMem)
     };
-    llmap.get().insert(p_id, llval);
-    add_clean(bcx, llval, var_ty);
-    return bcx;
+    {
+        let mut llmap = match binding_mode {
+            BindLocal => bcx.fcx.lllocals.borrow_mut(),
+            BindArgument => bcx.fcx.llargs.borrow_mut()
+        };
+        llmap.get().insert(p_id, datum);
+    }
+    let bcx = populate(bcx, datum);
+    datum.add_clean(bcx);
+    bcx
 }
 
 fn bind_irrefutable_pat<'a>(
@@ -2179,7 +2186,7 @@ fn bind_irrefutable_pat<'a>(
 
     let _indenter = indenter();
 
-    let _icx = push_ctxt("alt::bind_irrefutable_pat");
+    let _icx = push_ctxt("match::bind_irrefutable_pat");
     let mut bcx = bcx;
     let tcx = bcx.tcx();
     let ccx = bcx.ccx();
@@ -2191,21 +2198,23 @@ fn bind_irrefutable_pat<'a>(
                 // map.
                 bcx = mk_binding_alloca(
                     bcx, pat.id, path, binding_mode,
-                    |bcx, variable_ty, llvariable_val| {
+                    |bcx, var_datum| {
                         match pat_binding_mode {
                             ast::BindByValue(_) => {
                                 // By value binding: move the value that `val`
                                 // points at into the binding's stack slot.
-                                let datum = Datum {val: val,
-                                                   ty: variable_ty,
-                                                   mode: ByRef(ZeroMem)};
-                                datum.store_to(bcx, INIT, llvariable_val)
+                                let datum = Datum {
+                                    val: val,
+                                    ty: var_datum.ty,
+                                    mode: ByRef(ZeroMem)
+                                };
+                                datum.store_to(bcx, INIT, var_datum.val)
                             }
 
                             ast::BindByRef(_) => {
                                 // By ref binding: the value of the variable
                                 // is the pointer `val` itself.
-                                Store(bcx, val, llvariable_val);
+                                Store(bcx, val, var_datum.val);
                                 bcx
                             }
                         }
diff --git a/src/librustc/middle/trans/asm.rs b/src/librustc/middle/trans/asm.rs
index ffcbd59c9e0..11f217f3cb4 100644
--- a/src/librustc/middle/trans/asm.rs
+++ b/src/librustc/middle/trans/asm.rs
@@ -20,7 +20,6 @@ use middle::trans::callee;
 use middle::trans::common::*;
 use middle::trans::expr::*;
 use middle::trans::type_of::*;
-use middle::ty;
 
 use middle::trans::type_::Type;
 
@@ -56,7 +55,6 @@ pub fn trans_inline_asm<'a>(bcx: &'a Block<'a>, ia: &ast::InlineAsm)
         unpack_result!(bcx, {
             callee::trans_arg_expr(bcx,
                                    expr_ty(bcx, input),
-                                   ty::ByCopy,
                                    input,
                                    &mut cleanups,
                                    callee::DontAutorefArg)
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 2b39cbf7477..6fa3764fb37 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -53,12 +53,12 @@ use middle::trans::expr;
 use middle::trans::foreign;
 use middle::trans::glue;
 use middle::trans::inline;
-use middle::trans::llrepr::LlvmRepr;
 use middle::trans::machine;
 use middle::trans::machine::{llalign_of_min, llsize_of};
 use middle::trans::meth;
 use middle::trans::monomorphize;
 use middle::trans::tvec;
+use middle::trans::type_::Type;
 use middle::trans::type_of;
 use middle::trans::type_of::*;
 use middle::trans::value::Value;
@@ -66,7 +66,6 @@ use middle::ty;
 use util::common::indenter;
 use util::ppaux::{Repr, ty_to_str};
 use util::sha2::Sha256;
-use middle::trans::type_::Type;
 
 use extra::arena::TypedArena;
 use extra::time;
@@ -218,7 +217,7 @@ fn get_extern_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t,
         }
     }
 
-    let f = decl_rust_fn(ccx, inputs, output, name);
+    let f = decl_rust_fn(ccx, None, inputs, output, name);
     csearch::get_item_attrs(ccx.tcx.cstore, did, |meta_items| {
         set_llvm_fn_attrs(meta_items.iter().map(|&x| attr::mk_attr(x)).to_owned_vec(), f)
     });
@@ -228,8 +227,12 @@ fn get_extern_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t,
     f
 }
 
-fn decl_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t, name: &str) -> ValueRef {
-    let llfty = type_of_rust_fn(ccx, inputs, output);
+fn decl_rust_fn(ccx: &CrateContext,
+                self_ty: Option<ty::t>,
+                inputs: &[ty::t],
+                output: ty::t,
+                name: &str) -> ValueRef {
+    let llfty = type_of_rust_fn(ccx, self_ty, inputs, output);
     let llfn = decl_cdecl_fn(ccx.llmod, name, llfty);
 
     match ty::get(output).sty {
@@ -263,7 +266,7 @@ fn decl_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t, name: &str)
                     llvm::LLVMAddAttribute(llarg, lib::llvm::NoAliasAttribute as c_uint);
                 }
             }
-            _ => ()
+            _ => {}
         }
     }
 
@@ -281,9 +284,10 @@ fn decl_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t, name: &str)
     llfn
 }
 
-pub fn decl_internal_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t,
-                             name: &str) -> ValueRef {
-    let llfn = decl_rust_fn(ccx, inputs, output, name);
+pub fn decl_internal_rust_fn(ccx: &CrateContext,
+                             self_ty: Option<ty::t>, inputs: &[ty::t],
+                             output: ty::t, name: &str) -> ValueRef {
+    let llfn = decl_rust_fn(ccx, self_ty, inputs, output, name);
     lib::llvm::SetLinkage(llfn, lib::llvm::InternalLinkage);
     llfn
 }
@@ -913,7 +917,7 @@ pub fn trans_external_path(ccx: &CrateContext, did: ast::DefId, t: ty::t) -> Val
                 Some(..) | None => {
                     let c = foreign::llvm_calling_convention(ccx, fn_ty.abis);
                     let cconv = c.unwrap_or(lib::llvm::CCallConv);
-                    let llty = type_of_fn_from_ty(ccx, t);
+                    let llty = type_of_fn_from_ty(ccx, None, t);
                     let mut externs = ccx.externs.borrow_mut();
                     get_extern_fn(externs.get(), ccx.llmod, name, cconv, llty)
                 }
@@ -1013,7 +1017,7 @@ pub fn need_invoke(bcx: &Block) -> bool {
                 let cleanups = inf.cleanups.borrow();
                 for cleanup in cleanups.get().iter() {
                     match *cleanup {
-                        clean(_, cleanup_type) | clean_temp(_, _, cleanup_type) => {
+                        Clean(_, cleanup_type) | CleanTemp(_, _, cleanup_type) => {
                             if cleanup_type == normal_exit_and_unwind {
                                 return true;
                             }
@@ -1365,7 +1369,7 @@ pub fn trans_block_cleanups_<'a>(
     let mut bcx = bcx;
     for cu in cleanups.rev_iter() {
         match *cu {
-            clean(cfn, cleanup_type) | clean_temp(_, cfn, cleanup_type) => {
+            Clean(cfn, cleanup_type) | CleanTemp(_, cfn, cleanup_type) => {
                 // Some types don't need to be cleaned up during
                 // landing pads because they can be freed en mass later
                 if cleanup_type == normal_exit_and_unwind || !is_lpad {
@@ -1639,7 +1643,7 @@ pub fn zero_mem(cx: &Block, llptr: ValueRef, t: ty::t) {
 // allocation for large data structures, and the generated code will be
 // awful. (A telltale sign of this is large quantities of
 // `mov [byte ptr foo],0` in the generated code.)
-pub fn memzero(b: &Builder, llptr: ValueRef, ty: Type) {
+fn memzero(b: &Builder, llptr: ValueRef, ty: Type) {
     let _icx = push_ctxt("memzero");
     let ccx = b.ccx;
 
@@ -1865,69 +1869,116 @@ pub fn new_fn_ctxt(ccx: @CrateContext,
 // spaces that have been created for them (by code in the llallocas field of
 // the function's fn_ctxt).  create_llargs_for_fn_args populates the llargs
 // field of the fn_ctxt with
-pub fn create_llargs_for_fn_args(cx: &FunctionContext,
-                                 self_arg: self_arg,
-                                 args: &[ast::Arg])
-                                 -> ~[ValueRef] {
+fn create_llargs_for_fn_args(cx: &FunctionContext,
+                             self_arg: Option<ty::t>,
+                             arg_tys: &[ty::t])
+                             -> ~[datum::Datum] {
     let _icx = push_ctxt("create_llargs_for_fn_args");
 
     match self_arg {
-      impl_self(tt, self_mode) => {
-        cx.llself.set(Some(ValSelfData {
-            v: cx.llenv.get(),
-            t: tt,
-            is_copy: self_mode == ty::ByCopy
-        }));
-      }
-      no_self => ()
+        Some(t) => {
+            cx.llself.set(Some(datum::Datum {
+                val: cx.llenv.get(),
+                ty: t,
+                mode: if arg_is_indirect(cx.ccx, t) {
+                    datum::ByRef(datum::ZeroMem)
+                } else {
+                    datum::ByValue
+                }
+            }));
+        }
+        None => {}
     }
 
-    // Return an array containing the ValueRefs that we get from
-    // llvm::LLVMGetParam for each argument.
-    vec::from_fn(args.len(), |i| {
-        unsafe { llvm::LLVMGetParam(cx.llfn, cx.arg_pos(i) as c_uint) }
-    })
+    // Return an array wrapping the ValueRefs that we get from
+    // llvm::LLVMGetParam for each argument into datums.
+    arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
+        let llarg = unsafe { llvm::LLVMGetParam(cx.llfn, cx.arg_pos(i) as c_uint) };
+        datum::Datum {
+            val: llarg,
+            ty: arg_ty,
+            mode: if arg_is_indirect(cx.ccx, arg_ty) {
+                datum::ByRef(datum::ZeroMem)
+            } else {
+                datum::ByValue
+            }
+        }
+    }).collect()
 }
 
-pub fn copy_args_to_allocas<'a>(
-                            fcx: &FunctionContext<'a>,
+fn copy_args_to_allocas<'a>(fcx: &FunctionContext<'a>,
                             bcx: &'a Block<'a>,
                             args: &[ast::Arg],
-                            raw_llargs: &[ValueRef],
-                            arg_tys: &[ty::t])
+                            method: Option<&ast::Method>,
+                            raw_llargs: &[datum::Datum])
                             -> &'a Block<'a> {
-    debug!("copy_args_to_allocas: raw_llargs={} arg_tys={}",
-           raw_llargs.llrepr(fcx.ccx),
-           arg_tys.repr(fcx.ccx.tcx));
+    debug!("copy_args_to_allocas: args=[{}]",
+           raw_llargs.map(|d| d.to_str(fcx.ccx)).connect(", "));
 
     let _icx = push_ctxt("copy_args_to_allocas");
     let mut bcx = bcx;
 
     match fcx.llself.get() {
         Some(slf) => {
-            let self_val = if slf.is_copy
-                    && datum::appropriate_mode(bcx.ccx(), slf.t).is_by_value() {
-                let tmp = BitCast(bcx, slf.v, type_of(bcx.ccx(), slf.t));
-                let alloc = alloc_ty(bcx, slf.t, "__self");
-                Store(bcx, tmp, alloc);
-                alloc
+            let needs_indirection = if slf.mode.is_by_value() {
+                // FIXME(eddyb) #11445 Always needs indirection because of cleanup.
+                if true {
+                    true
+                } else {
+                    match method {
+                        Some(method) => {
+                            match method.explicit_self.node {
+                                ast::SelfValue(ast::MutMutable) => true,
+                                _ => false
+                            }
+                        }
+                        None => true
+                    }
+                }
+            } else {
+                false
+            };
+            let slf = if needs_indirection {
+                // HACK(eddyb) this is just slf.to_ref_datum(bcx) with a named alloca.
+                let alloc = alloc_ty(bcx, slf.ty, "__self");
+                Store(bcx, slf.val, alloc);
+                datum::Datum {
+                    val: alloc,
+                    ty: slf.ty,
+                    mode: datum::ByRef(datum::ZeroMem)
+                }
             } else {
-                PointerCast(bcx, slf.v, type_of(bcx.ccx(), slf.t).ptr_to())
+                slf
             };
 
-            fcx.llself.set(Some(ValSelfData {v: self_val, ..slf}));
-            add_clean(bcx, self_val, slf.t);
+            fcx.llself.set(Some(slf));
+            slf.add_clean(bcx);
 
             if fcx.ccx.sess.opts.extra_debuginfo {
-                debuginfo::create_self_argument_metadata(bcx, slf.t, self_val);
+                debuginfo::create_self_argument_metadata(bcx, slf.ty, slf.val);
             }
         }
         _ => {}
     }
 
-    for (arg_n, &arg_ty) in arg_tys.iter().enumerate() {
-        let raw_llarg = raw_llargs[arg_n];
-
+    for (i, &arg) in raw_llargs.iter().enumerate() {
+        let needs_indirection = if arg.mode.is_by_value() {
+            if fcx.ccx.sess.opts.extra_debuginfo {
+                true
+            } else {
+                // FIXME(eddyb) #11445 Always needs indirection because of cleanup.
+                if true {
+                    true
+                } else {
+                    match args[i].pat.node {
+                        ast::PatIdent(ast::BindByValue(ast::MutMutable), _, _) => true,
+                        _ => false
+                    }
+                }
+            }
+        } else {
+            false
+        };
         // For certain mode/type combinations, the raw llarg values are passed
         // by value.  However, within the fn body itself, we want to always
         // have all locals and arguments be by-ref so that we can cancel the
@@ -1935,18 +1986,28 @@ pub fn copy_args_to_allocas<'a>(
         // the argument would be passed by value, we store it into an alloca.
         // This alloca should be optimized away by LLVM's mem-to-reg pass in
         // the event it's not truly needed.
-        // only by value if immediate:
-        let llarg = if datum::appropriate_mode(bcx.ccx(), arg_ty).is_by_value() {
-            let alloc = alloc_ty(bcx, arg_ty, "__arg");
-            Store(bcx, raw_llarg, alloc);
-            alloc
+        let arg = if needs_indirection {
+            // HACK(eddyb) this is just arg.to_ref_datum(bcx) with a named alloca.
+            let alloc = match args[i].pat.node {
+                ast::PatIdent(_, ref path, _) => {
+                    let name = ast_util::path_to_ident(path).name;
+                    alloc_ty(bcx, arg.ty, token::interner_get(name))
+                }
+                _ => alloc_ty(bcx, arg.ty, "__arg")
+            };
+            Store(bcx, arg.val, alloc);
+            datum::Datum {
+                val: alloc,
+                ty: arg.ty,
+                mode: datum::ByRef(datum::ZeroMem)
+            }
         } else {
-            raw_llarg
+            arg
         };
-        bcx = _match::store_arg(bcx, args[arg_n].pat, llarg);
+        bcx = _match::store_arg(bcx, args[i].pat, arg);
 
         if fcx.ccx.sess.opts.extra_debuginfo {
-            debuginfo::create_argument_metadata(bcx, &args[arg_n]);
+            debuginfo::create_argument_metadata(bcx, &args[i]);
         }
     }
 
@@ -2001,8 +2062,6 @@ pub fn build_return_block(fcx: &FunctionContext, ret_cx: &Block) {
     Ret(ret_cx, retval);
 }
 
-pub enum self_arg { impl_self(ty::t, ty::SelfMode), no_self, }
-
 // trans_closure: Builds an LLVM function out of a source function.
 // If the function closes over its environment a closure will be
 // returned.
@@ -2011,9 +2070,10 @@ pub fn trans_closure(ccx: @CrateContext,
                      decl: &ast::FnDecl,
                      body: &ast::Block,
                      llfndecl: ValueRef,
-                     self_arg: self_arg,
+                     self_arg: Option<ty::t>,
                      param_substs: Option<@param_substs>,
                      id: ast::NodeId,
+                     method: Option<&ast::Method>,
                      _attributes: &[ast::Attribute],
                      output_type: ty::t,
                      maybe_load_env: |&FunctionContext|) {
@@ -2042,9 +2102,9 @@ pub fn trans_closure(ccx: @CrateContext,
 
     // Set up arguments to the function.
     let arg_tys = ty::ty_fn_args(node_id_type(bcx, id));
-    let raw_llargs = create_llargs_for_fn_args(&fcx, self_arg, decl.inputs);
+    let raw_llargs = create_llargs_for_fn_args(&fcx, self_arg, arg_tys);
 
-    bcx = copy_args_to_allocas(&fcx, bcx, decl.inputs, raw_llargs, arg_tys);
+    bcx = copy_args_to_allocas(&fcx, bcx, decl.inputs, method, raw_llargs);
 
     maybe_load_env(&fcx);
 
@@ -2089,9 +2149,10 @@ pub fn trans_fn(ccx: @CrateContext,
                 decl: &ast::FnDecl,
                 body: &ast::Block,
                 llfndecl: ValueRef,
-                self_arg: self_arg,
+                self_arg: Option<ty::t>,
                 param_substs: Option<@param_substs>,
                 id: ast::NodeId,
+                method: Option<&ast::Method>,
                 attrs: &[ast::Attribute]) {
 
     let the_path_str = path_str(ccx.sess, path);
@@ -2109,6 +2170,7 @@ pub fn trans_fn(ccx: @CrateContext,
                   self_arg,
                   param_substs,
                   id,
+                  method,
                   attrs,
                   output_type,
                   |_fcx| { });
@@ -2191,14 +2253,13 @@ impl IdAndTy for ast::StructField {
     fn ty(&self) -> ast::P<ast::Ty> { self.node.ty }
 }
 
-pub fn trans_enum_variant_or_tuple_like_struct<A:IdAndTy>(
+fn trans_enum_variant_or_tuple_like_struct<A:IdAndTy>(
     ccx: @CrateContext,
     ctor_id: ast::NodeId,
     args: &[A],
     disr: ty::Disr,
     param_substs: Option<@param_substs>,
-    llfndecl: ValueRef)
-{
+    llfndecl: ValueRef) {
     // Translate variant arguments to function arguments.
     let fn_args = args.map(|varg| {
         ast::Arg {
@@ -2247,12 +2308,12 @@ pub fn trans_enum_variant_or_tuple_like_struct<A:IdAndTy>(
 
     let arg_tys = ty::ty_fn_args(ctor_ty);
 
-    let raw_llargs = create_llargs_for_fn_args(&fcx, no_self, fn_args);
+    let raw_llargs = create_llargs_for_fn_args(&fcx, None, arg_tys);
 
     let bcx = fcx.entry_bcx.get().unwrap();
 
     insert_synthetic_type_entries(bcx, fn_args, arg_tys);
-    let bcx = copy_args_to_allocas(&fcx, bcx, fn_args, raw_llargs, arg_tys);
+    let bcx = copy_args_to_allocas(&fcx, bcx, fn_args, None, raw_llargs);
 
     let repr = adt::represent_type(ccx, result_ty);
     adt::trans_start_init(bcx, repr, fcx.llretptr.get().unwrap(), disr);
@@ -2266,8 +2327,7 @@ pub fn trans_enum_variant_or_tuple_like_struct<A:IdAndTy>(
             let llargs = fcx.llargs.borrow();
             llargs.get().get_copy(&fn_arg.pat.id)
         };
-        let arg_ty = arg_tys[i];
-        memcpy_ty(bcx, lldestptr, llarg, arg_ty);
+        llarg.move_to(bcx, datum::INIT, lldestptr);
     }
     finish_fn(&fcx, bcx);
 }
@@ -2334,9 +2394,10 @@ pub fn trans_item(ccx: @CrateContext, item: &ast::Item) {
                      decl,
                      body,
                      llfndecl,
-                     no_self,
+                     None,
                      None,
                      item.id,
+                     None,
                      item.attrs);
         } else {
             // Be sure to travel more than just one layer deep to catch nested
@@ -2448,12 +2509,13 @@ fn finish_register_fn(ccx: @CrateContext, sp: Span, sym: ~str, node_id: ast::Nod
     }
 }
 
-pub fn register_fn(ccx: @CrateContext,
-                   sp: Span,
-                   sym: ~str,
-                   node_id: ast::NodeId,
-                   node_type: ty::t)
-                   -> ValueRef {
+fn register_fn(ccx: @CrateContext,
+               sp: Span,
+               sym: ~str,
+               node_id: ast::NodeId,
+               node_type: ty::t,
+               self_ty: Option<ty::t>)
+               -> ValueRef {
     let f = match ty::get(node_type).sty {
         ty::ty_bare_fn(ref f) => {
             assert!(f.abis.is_rust() || f.abis.is_intrinsic());
@@ -2462,7 +2524,7 @@ pub fn register_fn(ccx: @CrateContext,
         _ => fail!("expected bare rust fn or an intrinsic")
     };
 
-    let llfn = decl_rust_fn(ccx, f.sig.inputs, f.sig.output, sym);
+    let llfn = decl_rust_fn(ccx, self_ty, f.sig.inputs, f.sig.output, sym);
     finish_register_fn(ccx, sp, sym, node_id, llfn);
     llfn
 }
@@ -2722,7 +2784,7 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
 
                         ast::ItemFn(_, purity, _, _, _) => {
                             let llfn = if purity != ast::ExternFn {
-                                register_fn(ccx, i.span, sym, i.id, ty)
+                                register_fn(ccx, i.span, sym, i.id, ty, None)
                             } else {
                                 foreign::register_rust_fn_with_foreign_abi(ccx,
                                                                            i.span,
@@ -2826,7 +2888,7 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
 
                             llfn = match enm.node {
                                 ast::ItemEnum(_, _) => {
-                                    register_fn(ccx, (*v).span, sym, id, ty)
+                                    register_fn(ccx, (*v).span, sym, id, ty, None)
                                 }
                                 _ => fail!("NodeVariant, shouldn't happen")
                             };
@@ -2851,7 +2913,7 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
                             let sym = exported_name(ccx, (*struct_path).clone(), ty,
                                                     struct_item.attrs);
                             let llfn = register_fn(ccx, struct_item.span,
-                                                   sym, ctor_id, ty);
+                                                   sym, ctor_id, ty, None);
                             set_inline_hint(llfn);
                             llfn
                         }
@@ -2881,10 +2943,10 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
     }
 }
 
-pub fn register_method(ccx: @CrateContext,
-                       id: ast::NodeId,
-                       path: @ast_map::Path,
-                       m: @ast::Method) -> ValueRef {
+fn register_method(ccx: @CrateContext,
+                   id: ast::NodeId,
+                   path: @ast_map::Path,
+                   m: &ast::Method) -> ValueRef {
     let mty = ty::node_id_to_type(ccx.tcx, id);
 
     let mut path = (*path).clone();
@@ -2892,7 +2954,11 @@ pub fn register_method(ccx: @CrateContext,
 
     let sym = exported_name(ccx, path, mty, m.attrs);
 
-    let llfn = register_fn(ccx, m.span, sym, id, mty);
+    let self_ty = match m.explicit_self.node {
+        ast::SelfStatic => None,
+        _ => Some(ty::node_id_to_type(ccx.tcx, m.self_id))
+    };
+    let llfn = register_fn(ccx, m.span, sym, id, mty, self_ty);
     set_llvm_fn_attrs(m.attrs, llfn);
     llfn
 }
diff --git a/src/librustc/middle/trans/callee.rs b/src/librustc/middle/trans/callee.rs
index 6ef90c57b27..c1451a8fe1e 100644
--- a/src/librustc/middle/trans/callee.rs
+++ b/src/librustc/middle/trans/callee.rs
@@ -60,8 +60,7 @@ pub struct FnData {
 pub struct MethodData {
     llfn: ValueRef,
     llself: ValueRef,
-    temp_cleanup: Option<ValueRef>,
-    self_mode: ty::SelfMode,
+    temp_cleanup: Option<ValueRef>
 }
 
 pub enum CalleeData {
@@ -398,7 +397,7 @@ pub fn trans_fn_ref_with_vtables(
             let ref_ty = common::node_id_type(bcx, ref_id);
 
             val = PointerCast(
-                bcx, val, type_of::type_of_fn_from_ty(ccx, ref_ty).ptr_to());
+                bcx, val, type_of::type_of_fn_from_ty(ccx, None, ref_ty).ptr_to());
         }
         return FnData {llfn: val};
     }
@@ -437,7 +436,7 @@ pub fn trans_fn_ref_with_vtables(
     // This can occur on either a crate-local or crate-external
     // reference. It also occurs when testing libcore and in some
     // other weird situations. Annoying.
-    let llty = type_of::type_of_fn_from_ty(ccx, fn_tpt.ty);
+    let llty = type_of::type_of_fn_from_ty(ccx, None, fn_tpt.ty);
     let llptrty = llty.ptr_to();
     if val_ty(val) != llptrty {
         val = BitCast(bcx, val, llptrty);
@@ -496,10 +495,7 @@ pub fn trans_method_call<'a>(
                            call_ex.repr(in_cx.tcx()),
                            origin.repr(in_cx.tcx()));
 
-                    meth::trans_method_callee(cx,
-                                              callee_id,
-                                              rcvr,
-                                              origin)
+                    meth::trans_method_callee(cx, callee_id, rcvr, origin)
                 }
                 None => {
                     cx.tcx().sess.span_bug(call_ex.span, "method call expr wasn't in method map")
@@ -799,7 +795,6 @@ pub fn trans_args<'a>(
             let arg_val = unpack_result!(bcx, {
                 trans_arg_expr(bcx,
                                arg_ty,
-                               ty::ByCopy,
                                *arg_expr,
                                &mut temp_cleanups,
                                autoref_arg)
@@ -832,7 +827,6 @@ pub enum AutorefArg {
 pub fn trans_arg_expr<'a>(
                       bcx: &'a Block<'a>,
                       formal_arg_ty: ty::t,
-                      self_mode: ty::SelfMode,
                       arg_expr: &ast::Expr,
                       temp_cleanups: &mut ~[ValueRef],
                       autoref_arg: AutorefArg)
@@ -840,9 +834,8 @@ pub fn trans_arg_expr<'a>(
     let _icx = push_ctxt("trans_arg_expr");
     let ccx = bcx.ccx();
 
-    debug!("trans_arg_expr(formal_arg_ty=({}), self_mode={:?}, arg_expr={})",
+    debug!("trans_arg_expr(formal_arg_ty=({}), arg_expr={})",
            formal_arg_ty.repr(bcx.tcx()),
-           self_mode,
            arg_expr.repr(bcx.tcx()));
 
     // translate the arg expr to a datum
@@ -888,16 +881,8 @@ pub fn trans_arg_expr<'a>(
                     arg_datum
                 };
 
-                val = match self_mode {
-                    ty::ByRef => {
-                        debug!("by ref arg with type {}", bcx.ty_to_str(arg_datum.ty));
-                        arg_datum.to_ref_llval(bcx)
-                    }
-                    ty::ByCopy => {
-                        debug!("by copy arg with type {}", bcx.ty_to_str(arg_datum.ty));
-                        arg_datum.to_appropriate_llval(bcx)
-                    }
-                }
+                debug!("by copy arg with type {}", bcx.ty_to_str(arg_datum.ty));
+                val = arg_datum.to_appropriate_llval(bcx);
             }
         }
 
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index 2cb3f8bcfac..25bc968b987 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/src/librustc/middle/trans/closure.rs
@@ -405,7 +405,7 @@ pub fn trans_expr_fn<'a>(
     let s = mangle_internal_name_by_path_and_seq(ccx,
                                                  sub_path.clone(),
                                                  "expr_fn");
-    let llfn = decl_internal_rust_fn(ccx, f.sig.inputs, f.sig.output, s);
+    let llfn = decl_internal_rust_fn(ccx, None, f.sig.inputs, f.sig.output, s);
 
     // set an inline hint for all closures
     set_inline_hint(llfn);
@@ -423,9 +423,10 @@ pub fn trans_expr_fn<'a>(
                           decl,
                           body,
                           llfn,
-                          no_self,
+                          None,
                           bcx.fcx.param_substs,
                           user_id,
+                          None,
                           [],
                           ty::ty_fn_ret(fty),
                           |fcx| load_environment(fcx, cdata_ty, cap_vars, sigil));
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index b31c03eb184..7f6ab2dd9d1 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -158,13 +158,6 @@ pub fn BuilderRef_res(B: BuilderRef) -> BuilderRef_res {
 
 pub type ExternMap = HashMap<~str, ValueRef>;
 
-// Types used for llself.
-pub struct ValSelfData {
-    v: ValueRef,
-    t: ty::t,
-    is_copy: bool,
-}
-
 // Here `self_ty` is the real type of the self parameter to this method. It
 // will only be set in the case of default methods.
 pub struct param_substs {
@@ -227,7 +220,7 @@ pub struct FunctionContext<'a> {
     // NB: This is the type of the self *variable*, not the self *type*. The
     // self type is set only for default methods, while the self variable is
     // set for all methods.
-    llself: Cell<Option<ValSelfData>>,
+    llself: Cell<Option<datum::Datum>>,
     // The a value alloca'd for calls to upcalls.rust_personality. Used when
     // outputting the resume instruction.
     personality: Cell<Option<ValueRef>>,
@@ -238,10 +231,10 @@ pub struct FunctionContext<'a> {
     caller_expects_out_pointer: bool,
 
     // Maps arguments to allocas created for them in llallocas.
-    llargs: RefCell<HashMap<ast::NodeId, ValueRef>>,
+    llargs: RefCell<HashMap<ast::NodeId, datum::Datum>>,
     // Maps the def_ids for local variables to the allocas created for
     // them in llallocas.
-    lllocals: RefCell<HashMap<ast::NodeId, ValueRef>>,
+    lllocals: RefCell<HashMap<ast::NodeId, datum::Datum>>,
     // Same as above, but for closure upvars
     llupvars: RefCell<HashMap<ast::NodeId, ValueRef>>,
 
@@ -342,28 +335,14 @@ pub trait CleanupFunction {
 }
 
 /// A cleanup function that calls the "drop glue" (destructor function) on
-/// a typed value.
-pub struct TypeDroppingCleanupFunction {
-    val: ValueRef,
-    t: ty::t,
-}
-
-impl CleanupFunction for TypeDroppingCleanupFunction {
-    fn clean<'a>(&self, block: &'a Block<'a>) -> &'a Block<'a> {
-        glue::drop_ty(block, self.val, self.t)
-    }
-}
-
-/// A cleanup function that calls the "drop glue" (destructor function) on
-/// an immediate typed value.
-pub struct ImmediateTypeDroppingCleanupFunction {
-    val: ValueRef,
-    t: ty::t,
+/// a datum.
+struct DatumDroppingCleanupFunction {
+    datum: datum::Datum
 }
 
-impl CleanupFunction for ImmediateTypeDroppingCleanupFunction {
+impl CleanupFunction for DatumDroppingCleanupFunction {
     fn clean<'a>(&self, block: &'a Block<'a>) -> &'a Block<'a> {
-        glue::drop_ty_immediate(block, self.val, self.t)
+        self.datum.drop_val(block)
     }
 }
 
@@ -390,16 +369,16 @@ impl CleanupFunction for ExchangeHeapFreeingCleanupFunction {
 }
 
 pub enum cleanup {
-    clean(@CleanupFunction, cleantype),
-    clean_temp(ValueRef, @CleanupFunction, cleantype),
+    Clean(@CleanupFunction, cleantype),
+    CleanTemp(ValueRef, @CleanupFunction, cleantype),
 }
 
 // Can't use deriving(Clone) because of the managed closure.
 impl Clone for cleanup {
     fn clone(&self) -> cleanup {
         match *self {
-            clean(f, ct) => clean(f, ct),
-            clean_temp(v, f, ct) => clean_temp(v, f, ct),
+            Clean(f, ct) => Clean(f, ct),
+            CleanTemp(v, f, ct) => CleanTemp(v, f, ct),
         }
     }
 }
@@ -438,20 +417,21 @@ pub fn cleanup_type(cx: ty::ctxt, ty: ty::t) -> cleantype {
     }
 }
 
-pub fn add_clean(bcx: &Block, val: ValueRef, t: ty::t) {
-    if !ty::type_needs_drop(bcx.tcx(), t) {
-        return
-    }
+pub fn add_clean(bcx: &Block, val: ValueRef, ty: ty::t) {
+    if !ty::type_needs_drop(bcx.tcx(), ty) { return; }
 
-    debug!("add_clean({}, {}, {})", bcx.to_str(), bcx.val_to_str(val), t.repr(bcx.tcx()));
+    debug!("add_clean({}, {}, {})", bcx.to_str(), bcx.val_to_str(val), ty.repr(bcx.tcx()));
 
-    let cleanup_type = cleanup_type(bcx.tcx(), t);
+    let cleanup_type = cleanup_type(bcx.tcx(), ty);
     in_scope_cx(bcx, None, |scope_info| {
         {
             let mut cleanups = scope_info.cleanups.borrow_mut();
-            cleanups.get().push(clean(@TypeDroppingCleanupFunction {
-                val: val,
-                t: t,
+            cleanups.get().push(Clean(@DatumDroppingCleanupFunction {
+                datum: datum::Datum {
+                    val: val,
+                    ty: ty,
+                    mode: datum::ByRef(datum::ZeroMem)
+                }
             } as @CleanupFunction,
             cleanup_type));
         }
@@ -459,21 +439,24 @@ pub fn add_clean(bcx: &Block, val: ValueRef, t: ty::t) {
     })
 }
 
-pub fn add_clean_temp_immediate(cx: &Block, val: ValueRef, ty: ty::t) {
-    if !ty::type_needs_drop(cx.tcx(), ty) { return; }
+pub fn add_clean_temp_immediate(bcx: &Block, val: ValueRef, ty: ty::t) {
+    if !ty::type_needs_drop(bcx.tcx(), ty) { return; }
+
     debug!("add_clean_temp_immediate({}, {}, {})",
-           cx.to_str(), cx.val_to_str(val),
-           ty.repr(cx.tcx()));
-    let cleanup_type = cleanup_type(cx.tcx(), ty);
-    in_scope_cx(cx, None, |scope_info| {
+           bcx.to_str(), bcx.val_to_str(val),
+           ty.repr(bcx.tcx()));
+    let cleanup_type = cleanup_type(bcx.tcx(), ty);
+    in_scope_cx(bcx, None, |scope_info| {
         {
             let mut cleanups = scope_info.cleanups.borrow_mut();
-            cleanups.get().push(clean_temp(val,
-                @ImmediateTypeDroppingCleanupFunction {
+            cleanups.get().push(CleanTemp(val, @DatumDroppingCleanupFunction {
+                datum: datum::Datum {
                     val: val,
-                    t: ty,
-                } as @CleanupFunction,
-                cleanup_type));
+                    ty: ty,
+                    mode: datum::ByValue
+                }
+            } as @CleanupFunction,
+            cleanup_type));
         }
         grow_scope_clean(scope_info);
     })
@@ -500,12 +483,14 @@ pub fn add_clean_temp_mem_in_scope_(bcx: &Block, scope_id: Option<ast::NodeId>,
     in_scope_cx(bcx, scope_id, |scope_info| {
         {
             let mut cleanups = scope_info.cleanups.borrow_mut();
-            cleanups.get().push(clean_temp(val,
-                @TypeDroppingCleanupFunction {
+            cleanups.get().push(CleanTemp(val, @DatumDroppingCleanupFunction {
+                datum: datum::Datum {
                     val: val,
-                    t: t,
-                } as @CleanupFunction,
-                cleanup_type));
+                    ty: t,
+                    mode: datum::ByRef(datum::RevokeClean)
+                }
+            } as @CleanupFunction,
+            cleanup_type));
         }
         grow_scope_clean(scope_info);
     })
@@ -527,7 +512,7 @@ pub fn add_clean_free(cx: &Block, ptr: ValueRef, heap: heap) {
     in_scope_cx(cx, None, |scope_info| {
         {
             let mut cleanups = scope_info.cleanups.borrow_mut();
-            cleanups.get().push(clean_temp(ptr,
+            cleanups.get().push(CleanTemp(ptr,
                                            free_fn,
                                            normal_exit_and_unwind));
         }
@@ -543,22 +528,26 @@ pub fn revoke_clean(cx: &Block, val: ValueRef) {
     in_scope_cx(cx, None, |scope_info| {
         let cleanup_pos = {
             let mut cleanups = scope_info.cleanups.borrow_mut();
+            debug!("revoke_clean({}, {}) revoking {:?} from {:?}",
+                   cx.to_str(), cx.val_to_str(val), val, cleanups.get());
             cleanups.get().iter().position(|cu| {
                 match *cu {
-                    clean_temp(v, _, _) if v == val => true,
+                    CleanTemp(v, _, _) if v == val => true,
                     _ => false
                 }
             })
         };
-        for i in cleanup_pos.iter() {
+        debug!("revoke_clean({}, {}) revoking {:?}",
+               cx.to_str(), cx.val_to_str(val), cleanup_pos);
+        for &i in cleanup_pos.iter() {
             let new_cleanups = {
                 let cleanups = scope_info.cleanups.borrow();
-                vec::append(cleanups.get().slice(0u, *i).to_owned(),
-                            cleanups.get().slice(*i + 1u, cleanups.get()
-                                                                  .len()))
+                vec::append(cleanups.get().slice(0u, i).to_owned(),
+                            cleanups.get().slice(i + 1u, cleanups.get()
+                                                                 .len()))
             };
             scope_info.cleanups.set(new_cleanups);
-            shrink_scope_clean(scope_info, *i);
+            shrink_scope_clean(scope_info, i);
         }
     })
 }
@@ -767,16 +756,16 @@ pub fn in_scope_cx<'a>(
             Some(inf) => match scope_id {
                 Some(wanted) => match inf.node_info {
                     Some(NodeInfo { id: actual, .. }) if wanted == actual => {
-                        debug!("in_scope_cx: selected cur={} (cx={})",
-                               cur.to_str(), cx.to_str());
+                        debug!("in_scope_cx: selected cur={} (cx={}) info={:?}",
+                               cur.to_str(), cx.to_str(), inf.node_info);
                         f(inf);
                         return;
                     },
                     _ => inf.parent,
                 },
                 None => {
-                    debug!("in_scope_cx: selected cur={} (cx={})",
-                           cur.to_str(), cx.to_str());
+                    debug!("in_scope_cx: selected cur={} (cx={}) info={:?}",
+                           cur.to_str(), cx.to_str(), inf.node_info);
                     f(inf);
                     return;
                 }
@@ -1042,8 +1031,7 @@ pub enum MonoDataClass {
 pub fn mono_data_classify(t: ty::t) -> MonoDataClass {
     match ty::get(t).sty {
         ty::ty_float(_) => MonoFloat,
-        ty::ty_rptr(..) | ty::ty_uniq(..) |
-        ty::ty_box(..) | ty::ty_opaque_box(..) |
+        ty::ty_rptr(..) | ty::ty_uniq(..) | ty::ty_box(..) |
         ty::ty_str(ty::vstore_uniq) | ty::ty_vec(_, ty::vstore_uniq) |
         ty::ty_str(ty::vstore_box) | ty::ty_vec(_, ty::vstore_box) |
         ty::ty_bare_fn(..) => MonoNonNull,
diff --git a/src/librustc/middle/trans/datum.rs b/src/librustc/middle/trans/datum.rs
index 4f94668ebe3..e7eab31ac14 100644
--- a/src/librustc/middle/trans/datum.rs
+++ b/src/librustc/middle/trans/datum.rs
@@ -113,6 +113,7 @@ pub enum CopyAction {
     DROP_EXISTING
 }
 
+#[deriving(Clone)]
 pub struct Datum {
     /// The llvm value.  This is either a pointer to the Rust value or
     /// the value itself, depending on `mode` below.
@@ -130,7 +131,7 @@ pub struct DatumBlock<'a> {
     datum: Datum,
 }
 
-#[deriving(Eq, IterBytes)]
+#[deriving(Clone, Eq, IterBytes)]
 pub enum DatumMode {
     /// `val` is a pointer to the actual value (and thus has type *T).
     /// The argument indicates how to cancel cleanup of this datum if
@@ -153,7 +154,7 @@ impl DatumMode {
 }
 
 /// See `Datum cleanup styles` section at the head of this module.
-#[deriving(Eq, IterBytes)]
+#[deriving(Clone, Eq, IterBytes)]
 pub enum DatumCleanup {
     RevokeClean,
     ZeroMem
@@ -396,8 +397,7 @@ impl Datum {
                 add_clean_temp_mem(bcx, self.val, self.ty);
             }
             ByRef(ZeroMem) => {
-                bcx.tcx().sess.bug(
-                    format!("Cannot add clean to a 'zero-mem' datum"));
+                add_clean(bcx, self.val, self.ty)
             }
         }
     }
@@ -413,7 +413,6 @@ impl Datum {
                     // Lvalues which potentially need to be dropped
                     // must be passed by ref, so that we can zero them
                     // out.
-                    assert!(self.mode.is_by_ref());
                     zero_mem(bcx, self.val, self.ty);
                 }
             }
diff --git a/src/librustc/middle/trans/debuginfo.rs b/src/librustc/middle/trans/debuginfo.rs
index 88d41f9b1af..fa620cca35e 100644
--- a/src/librustc/middle/trans/debuginfo.rs
+++ b/src/librustc/middle/trans/debuginfo.rs
@@ -133,6 +133,7 @@ use middle::trans::adt;
 use middle::trans::base;
 use middle::trans::build;
 use middle::trans::common::*;
+use middle::trans::datum;
 use middle::trans::machine;
 use middle::trans::type_of;
 use middle::trans::type_::Type;
@@ -280,12 +281,11 @@ pub fn create_local_var_metadata(bcx: &Block, local: &ast::Local) {
 
     pat_util::pat_bindings(def_map, local.pat, |_, node_id, span, path_ref| {
         let var_ident = ast_util::path_to_ident(path_ref);
-        let var_type = node_id_type(bcx, node_id);
 
-        let llptr = {
+        let datum = {
             let lllocals = bcx.fcx.lllocals.borrow();
             match lllocals.get().find_copy(&node_id) {
-                Some(v) => v,
+                Some(datum) => datum,
                 None => {
                     bcx.tcx().sess.span_bug(span,
                         format!("No entry in lllocals table for {:?}",
@@ -298,9 +298,9 @@ pub fn create_local_var_metadata(bcx: &Block, local: &ast::Local) {
 
         declare_local(bcx,
                       var_ident,
-                      var_type,
+                      datum.ty,
                       scope_metadata,
-                      DirectVariable { alloca: llptr },
+                      DirectVariable { alloca: datum.val },
                       LocalVariable,
                       span);
     })
@@ -382,33 +382,19 @@ pub fn create_captured_var_metadata(bcx: &Block,
 pub fn create_match_binding_metadata(bcx: &Block,
                                      variable_ident: ast::Ident,
                                      node_id: ast::NodeId,
-                                     variable_type: ty::t,
-                                     span: Span) {
+                                     span: Span,
+                                     datum: datum::Datum) {
     if fn_should_be_ignored(bcx.fcx) {
         return;
     }
 
-    let llptr = {
-        let lllocals = bcx.fcx.lllocals.borrow();
-        match lllocals.get().find_copy(&node_id) {
-            Some(v) => v,
-            None => {
-                bcx.tcx()
-                   .sess
-                   .span_bug(span,
-                             format!("No entry in lllocals table for {:?}",
-                                     node_id));
-            }
-        }
-    };
-
     let scope_metadata = scope_metadata(bcx.fcx, node_id, span);
 
     declare_local(bcx,
                   variable_ident,
-                  variable_type,
+                  datum.ty,
                   scope_metadata,
-                  DirectVariable { alloca: llptr },
+                  DirectVariable { alloca: datum.val },
                   LocalVariable,
                   span);
 }
@@ -506,7 +492,7 @@ pub fn create_argument_metadata(bcx: &Block, arg: &ast::Arg) {
     let scope_metadata = bcx.fcx.debug_context.get_ref(cx, arg.pat.span).fn_metadata;
 
     pat_util::pat_bindings(def_map, arg.pat, |_, node_id, span, path_ref| {
-        let llptr = {
+        let llarg = {
             let llargs = bcx.fcx.llargs.borrow();
             match llargs.get().find_copy(&node_id) {
                 Some(v) => v,
@@ -518,12 +504,11 @@ pub fn create_argument_metadata(bcx: &Block, arg: &ast::Arg) {
             }
         };
 
-        if unsafe { llvm::LLVMIsAAllocaInst(llptr) } == ptr::null() {
+        if unsafe { llvm::LLVMIsAAllocaInst(llarg.val) } == ptr::null() {
             cx.sess.span_bug(span, "debuginfo::create_argument_metadata() - \
                                     Referenced variable location is not an alloca!");
         }
 
-        let argument_type = node_id_type(bcx, node_id);
         let argument_ident = ast_util::path_to_ident(path_ref);
 
         let argument_index = {
@@ -535,9 +520,9 @@ pub fn create_argument_metadata(bcx: &Block, arg: &ast::Arg) {
 
         declare_local(bcx,
                       argument_ident,
-                      argument_type,
+                      llarg.ty,
                       scope_metadata,
-                      DirectVariable { alloca: llptr },
+                      DirectVariable { alloca: llarg.val },
                       ArgumentVariable(argument_index),
                       span);
     })
@@ -2185,9 +2170,6 @@ fn type_metadata(cx: &CrateContext,
         },
         ty::ty_tup(ref elements) => {
             prepare_tuple_metadata(cx, t, *elements, usage_site_span).finalize(cx)
-        },
-        ty::ty_opaque_box => {
-            create_pointer_to_box_metadata(cx, t, ty::mk_nil())
         }
         _ => cx.sess.bug(format!("debuginfo: unexpected type in type_metadata: {:?}", sty))
     };
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index 689c1ab1e05..1641e4a8bde 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/src/librustc/middle/trans/expr.rs
@@ -1172,7 +1172,7 @@ pub fn trans_local_var(bcx: &Block, def: ast::Def) -> Datum {
             take_local(bcx, lllocals.get(), nid)
         }
         ast::DefSelf(nid, _) => {
-            let self_info: ValSelfData = match bcx.fcx.llself.get() {
+            let self_info = match bcx.fcx.llself.get() {
                 Some(self_info) => self_info,
                 None => {
                     bcx.sess().bug(format!(
@@ -1181,14 +1181,10 @@ pub fn trans_local_var(bcx: &Block, def: ast::Def) -> Datum {
                 }
             };
 
-            debug!("def_self() reference, self_info.t={}",
-                   self_info.t.repr(bcx.tcx()));
+            debug!("def_self() reference, self_info.ty={}",
+                   self_info.ty.repr(bcx.tcx()));
 
-            Datum {
-                val: self_info.v,
-                ty: self_info.t,
-                mode: ByRef(ZeroMem)
-            }
+            self_info
         }
         _ => {
             bcx.sess().unimpl(format!(
@@ -1197,24 +1193,18 @@ pub fn trans_local_var(bcx: &Block, def: ast::Def) -> Datum {
     };
 
     fn take_local(bcx: &Block,
-                  table: &HashMap<ast::NodeId, ValueRef>,
-                  nid: ast::NodeId)
-                  -> Datum {
-        let v = match table.find(&nid) {
+                  table: &HashMap<ast::NodeId, Datum>,
+                  nid: ast::NodeId) -> Datum {
+        let datum = match table.find(&nid) {
             Some(&v) => v,
             None => {
                 bcx.sess().bug(format!(
-                    "trans_local_var: no llval for local/arg {:?} found", nid));
+                    "trans_local_var: no datum for local/arg {:?} found", nid));
             }
         };
-        let ty = node_id_type(bcx, nid);
         debug!("take_local(nid={:?}, v={}, ty={})",
-               nid, bcx.val_to_str(v), bcx.ty_to_str(ty));
-        Datum {
-            val: v,
-            ty: ty,
-            mode: ByRef(ZeroMem)
-        }
+               nid, bcx.val_to_str(datum.val), bcx.ty_to_str(datum.ty));
+        datum
     }
 }
 
diff --git a/src/librustc/middle/trans/foreign.rs b/src/librustc/middle/trans/foreign.rs
index 487aaa528ed..304edb2c312 100644
--- a/src/librustc/middle/trans/foreign.rs
+++ b/src/librustc/middle/trans/foreign.rs
@@ -489,16 +489,17 @@ pub fn trans_rust_fn_with_foreign_abi(ccx: @CrateContext,
                id,
                t.repr(tcx));
 
-        let llfndecl = base::decl_internal_rust_fn(ccx, f.sig.inputs, f.sig.output, ps);
+        let llfndecl = base::decl_internal_rust_fn(ccx, None, f.sig.inputs, f.sig.output, ps);
         base::set_llvm_fn_attrs(attrs, llfndecl);
         base::trans_fn(ccx,
                        (*path).clone(),
                        decl,
                        body,
                        llfndecl,
-                       base::no_self,
+                       None,
                        None,
                        id,
+                       None,
                        []);
         return llfndecl;
     }
diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index 3063fbcecaf..16a761a44db 100644
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -93,84 +93,67 @@ pub fn lazily_emit_all_tydesc_glue(ccx: @CrateContext,
     lazily_emit_tydesc_glue(ccx, abi::tydesc_field_visit_glue, static_ti);
 }
 
-pub fn simplified_glue_type(tcx: ty::ctxt, field: uint, t: ty::t) -> ty::t {
-    if (field == abi::tydesc_field_take_glue ||
-        field == abi::tydesc_field_drop_glue) &&
-        ! ty::type_needs_drop(tcx, t) {
-          return ty::mk_u32();
+fn simplified_glue_type(tcx: ty::ctxt, field: uint, t: ty::t) -> ty::t {
+    if (field == abi::tydesc_field_take_glue || field == abi::tydesc_field_drop_glue)
+        && !ty::type_needs_drop(tcx, t) {
+        return ty::mk_nil();
     }
 
     if field == abi::tydesc_field_take_glue {
         match ty::get(t).sty {
-          ty::ty_unboxed_vec(..) |
-              ty::ty_uniq(..) |
-              ty::ty_str(ty::vstore_uniq) |
-              ty::ty_vec(_, ty::vstore_uniq) => { return ty::mk_u32(); }
-          _ => ()
+            ty::ty_str(ty::vstore_uniq) |  ty::ty_vec(_, ty::vstore_uniq) |
+            ty::ty_unboxed_vec(..) | ty::ty_uniq(..) => return ty::mk_nil(),
+            _ => {}
         }
     }
 
-    if field == abi::tydesc_field_take_glue &&
-        ty::type_is_boxed(t) {
-          return ty::mk_imm_box(tcx, ty::mk_u32());
+    if field == abi::tydesc_field_take_glue && ty::type_is_boxed(t) {
+        return ty::mk_imm_box(tcx, ty::mk_nil());
     }
 
     if field == abi::tydesc_field_drop_glue {
         match ty::get(t).sty {
-          ty::ty_box(typ)
-          if ! ty::type_needs_drop(tcx, typ) =>
-          return ty::mk_imm_box(tcx, ty::mk_u32()),
+            ty::ty_box(typ)
+                if !ty::type_needs_drop(tcx, typ) =>
+            return ty::mk_imm_box(tcx, ty::mk_nil()),
 
-          ty::ty_vec(mt, ty::vstore_box)
-          if ! ty::type_needs_drop(tcx, mt.ty) =>
-          return ty::mk_imm_box(tcx, ty::mk_u32()),
+            ty::ty_vec(mt, ty::vstore_box)
+                if !ty::type_needs_drop(tcx, mt.ty) =>
+            return ty::mk_imm_box(tcx, ty::mk_nil()),
 
-          ty::ty_uniq(mt) |
-          ty::ty_vec(mt, ty::vstore_uniq)
-          if ! ty::type_needs_drop(tcx, mt.ty) =>
-          return ty::mk_imm_uniq(tcx, ty::mk_u32()),
+            ty::ty_uniq(mt) | ty::ty_vec(mt, ty::vstore_uniq)
+                if !ty::type_needs_drop(tcx, mt.ty) =>
+            return ty::mk_imm_uniq(tcx, ty::mk_nil()),
 
-          _ => ()
+            _ => {}
         }
     }
 
-    return t;
+    t
 }
 
-pub fn lazily_emit_simplified_tydesc_glue(ccx: @CrateContext,
-                                          field: uint,
-                                          ti: &tydesc_info)
-                                          -> bool {
-    let _icx = push_ctxt("lazily_emit_simplified_tydesc_glue");
+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);
     if simpl != ti.ty {
+        let _icx = push_ctxt("lazily_emit_simplified_tydesc_glue");
         let simpl_ti = get_tydesc(ccx, simpl);
         lazily_emit_tydesc_glue(ccx, field, simpl_ti);
-        {
-            if field == abi::tydesc_field_take_glue {
-                ti.take_glue.set(simpl_ti.take_glue.get());
-            } else if field == abi::tydesc_field_drop_glue {
-                ti.drop_glue.set(simpl_ti.drop_glue.get());
-            } else if field == abi::tydesc_field_visit_glue {
-                ti.visit_glue.set(simpl_ti.visit_glue.get());
-            }
-        }
-        return true;
-    }
-    return false;
-}
 
+        if field == abi::tydesc_field_take_glue {
+            ti.take_glue.set(simpl_ti.take_glue.get());
+        } else if field == abi::tydesc_field_drop_glue {
+            ti.drop_glue.set(simpl_ti.drop_glue.get());
+        } else if field == abi::tydesc_field_visit_glue {
+            ti.visit_glue.set(simpl_ti.visit_glue.get());
+        }
 
-pub fn lazily_emit_tydesc_glue(ccx: @CrateContext,
-                               field: uint,
-                               ti: @tydesc_info) {
-    let _icx = push_ctxt("lazily_emit_tydesc_glue");
-    let llfnty = Type::glue_fn(type_of(ccx, ti.ty).ptr_to());
-
-    if lazily_emit_simplified_tydesc_glue(ccx, field, ti) {
         return;
     }
 
+    let llfnty = Type::glue_fn(type_of(ccx, ti.ty).ptr_to());
+
     if field == abi::tydesc_field_take_glue {
         match ti.take_glue.get() {
           Some(_) => (),
@@ -271,16 +254,12 @@ pub fn call_tydesc_glue_full(bcx: &Block,
 }
 
 // See [Note-arg-mode]
-pub fn call_tydesc_glue<'a>(
-                        cx: &'a Block<'a>,
-                        v: ValueRef,
-                        t: ty::t,
-                        field: uint)
-                        -> &'a Block<'a> {
+fn call_tydesc_glue<'a>(cx: &'a Block<'a>, v: ValueRef, t: ty::t, field: uint)
+                    -> &'a Block<'a> {
     let _icx = push_ctxt("call_tydesc_glue");
     let ti = get_tydesc(cx.ccx(), t);
     call_tydesc_glue_full(cx, v, ti.tydesc, field, Some(ti));
-    return cx;
+    cx
 }
 
 fn make_visit_glue<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t)
@@ -308,7 +287,6 @@ pub fn make_free_glue<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t)
     // NB: v0 is an *alias* of type t here, not a direct value.
     let _icx = push_ctxt("make_free_glue");
     match ty::get(t).sty {
-      ty::ty_opaque_box => bcx.tcx().sess.fatal("found ty_opaque_box in make_free_glue"),
       ty::ty_box(body_ty) => {
         let v = Load(bcx, v);
         let body = GEPi(bcx, v, [0u, abi::box_field_body]);
@@ -407,7 +385,6 @@ pub fn make_drop_glue<'a>(bcx: &'a Block<'a>, v0: ValueRef, t: ty::t)
     let _icx = push_ctxt("make_drop_glue");
     let ccx = bcx.ccx();
     match ty::get(t).sty {
-      ty::ty_opaque_box => bcx.tcx().sess.fatal("found ty_opaque_box in make_drop_glue"),
       ty::ty_box(_) |
       ty::ty_str(ty::vstore_box) | ty::ty_vec(_, ty::vstore_box) => {
         decr_refcnt_maybe_free(bcx, v0, Some(t))
@@ -509,7 +486,6 @@ fn make_take_glue<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t) -> &'a Block<'a
     let _icx = push_ctxt("make_take_glue");
     // NB: v is a *pointer* to type t here, not a direct value.
     match ty::get(t).sty {
-      ty::ty_opaque_box => bcx.tcx().sess.fatal("found ty_opaque_box in make_take_glue"),
       ty::ty_box(_) |
       ty::ty_vec(_, ty::vstore_box) | ty::ty_str(ty::vstore_box) => {
         incr_refcnt_of_boxed(bcx, Load(bcx, v)); bcx
@@ -610,11 +586,8 @@ pub fn declare_tydesc(ccx: &CrateContext, t: ty::t) -> @tydesc_info {
     return inf;
 }
 
-pub type glue_helper<'a> =
-    'a |&'a Block<'a>, ValueRef, ty::t| -> &'a Block<'a>;
-
-pub fn declare_generic_glue(ccx: &CrateContext, t: ty::t, llfnty: Type,
-                            name: &str) -> ValueRef {
+fn declare_generic_glue(ccx: &CrateContext, t: ty::t, llfnty: Type,
+                        name: &str) -> ValueRef {
     let _icx = push_ctxt("declare_generic_glue");
     let fn_nm = mangle_internal_name_by_type_and_seq(ccx, t, (~"glue_" + name)).to_managed();
     debug!("{} is for type {}", fn_nm, ppaux::ty_to_str(ccx.tcx, t));
@@ -623,12 +596,14 @@ pub fn declare_generic_glue(ccx: &CrateContext, t: ty::t, llfnty: Type,
     return llfn;
 }
 
-pub fn make_generic_glue_inner(ccx: @CrateContext,
-                               t: ty::t,
-                               llfn: ValueRef,
-                               helper: glue_helper)
-                            -> ValueRef {
-    let _icx = push_ctxt("make_generic_glue_inner");
+pub type glue_helper<'a> =
+    'a |&'a Block<'a>, ValueRef, ty::t| -> &'a Block<'a>;
+
+fn make_generic_glue(ccx: @CrateContext, t: ty::t, llfn: ValueRef,
+                     helper: glue_helper, name: &str) -> ValueRef {
+    let _icx = push_ctxt("make_generic_glue");
+    let glue_name = format!("glue {} {}", name, ty_to_short_str(ccx.tcx, t));
+    let _s = StatRecorder::new(ccx, glue_name);
 
     let fcx = new_fn_ctxt(ccx, ~[], llfn, ty::mk_nil(), None);
     init_function(&fcx, false, ty::mk_nil(), None, None);
@@ -644,25 +619,12 @@ pub fn make_generic_glue_inner(ccx: @CrateContext,
     // type, so we don't need to explicitly cast the function parameter.
 
     let bcx = fcx.entry_bcx.get().unwrap();
-    let rawptr0_arg = fcx.arg_pos(0u);
-    let llrawptr0 = unsafe { llvm::LLVMGetParam(llfn, rawptr0_arg as c_uint) };
+    let llrawptr0 = unsafe { llvm::LLVMGetParam(llfn, fcx.arg_pos(0) as c_uint) };
     let bcx = helper(bcx, llrawptr0, t);
 
     finish_fn(&fcx, bcx);
 
-    return llfn;
-}
-
-pub fn make_generic_glue(ccx: @CrateContext,
-                         t: ty::t,
-                         llfn: ValueRef,
-                         helper: glue_helper,
-                         name: &str)
-                      -> ValueRef {
-    let _icx = push_ctxt("make_generic_glue");
-    let glue_name = format!("glue {} {}", name, ty_to_short_str(ccx.tcx, t));
-    let _s = StatRecorder::new(ccx, glue_name);
-    make_generic_glue_inner(ccx, t, llfn, helper)
+    llfn
 }
 
 pub fn emit_tydescs(ccx: &CrateContext) {
diff --git a/src/librustc/middle/trans/inline.rs b/src/librustc/middle/trans/inline.rs
index f571d35bb28..7d0e5a43544 100644
--- a/src/librustc/middle/trans/inline.rs
+++ b/src/librustc/middle/trans/inline.rs
@@ -11,8 +11,7 @@
 use lib::llvm::{AvailableExternallyLinkage, SetLinkage};
 use metadata::csearch;
 use middle::astencode;
-use middle::trans::base::{push_ctxt, impl_self, no_self};
-use middle::trans::base::{trans_item, get_item_val, trans_fn};
+use middle::trans::base::{push_ctxt, trans_item, get_item_val, trans_fn};
 use middle::trans::common::*;
 use middle::ty;
 use util::ppaux::ty_to_str;
@@ -162,16 +161,13 @@ pub fn maybe_instantiate_inline(ccx: @CrateContext, fn_id: ast::DefId)
               let path = vec::append_one(
                   ty::item_path(ccx.tcx, impl_did), PathName(mth.ident));
               let self_kind = match mth.explicit_self.node {
-                  ast::SelfStatic => no_self,
+                  ast::SelfStatic => None,
                   _ => {
                       let self_ty = ty::node_id_to_type(ccx.tcx,
                                                         mth.self_id);
                       debug!("calling inline trans_fn with self_ty {}",
                              ty_to_str(ccx.tcx, self_ty));
-                      match mth.explicit_self.node {
-                          ast::SelfValue(_) => impl_self(self_ty, ty::ByRef),
-                          _ => impl_self(self_ty, ty::ByCopy),
-                      }
+                      Some(self_ty)
                   }
               };
               trans_fn(ccx,
@@ -182,6 +178,7 @@ pub fn maybe_instantiate_inline(ccx: @CrateContext, fn_id: ast::DefId)
                        self_kind,
                        None,
                        mth.id,
+                       Some(&*mth),
                        []);
           }
           local_def(mth.id)
diff --git a/src/librustc/middle/trans/intrinsic.rs b/src/librustc/middle/trans/intrinsic.rs
index b001802f165..126aa9e7be5 100644
--- a/src/librustc/middle/trans/intrinsic.rs
+++ b/src/librustc/middle/trans/intrinsic.rs
@@ -430,7 +430,7 @@ pub fn trans_intrinsic(ccx: @CrateContext,
             // XXX This is a hack to grab the address of this particular
             // native function. There should be a general in-language
             // way to do this
-            let llfty = type_of_rust_fn(bcx.ccx(), [], ty::mk_nil());
+            let llfty = type_of_rust_fn(bcx.ccx(), None, [], ty::mk_nil());
             let morestack_addr = decl_cdecl_fn(
                 bcx.ccx().llmod, "__morestack", llfty);
             let morestack_addr = PointerCast(bcx, morestack_addr, Type::nil().ptr_to());
diff --git a/src/librustc/middle/trans/meth.rs b/src/librustc/middle/trans/meth.rs
index f526fb528c5..2ab495226a8 100644
--- a/src/librustc/middle/trans/meth.rs
+++ b/src/librustc/middle/trans/meth.rs
@@ -76,7 +76,7 @@ pub fn trans_impl(ccx: @CrateContext,
                          path,
                          *method,
                          None,
-                         llfn);
+                         |_| llfn);
         } else {
             let mut v = TransItemVisitor{ ccx: ccx };
             visit::walk_method_helper(&mut v, *method, ());
@@ -91,7 +91,7 @@ pub fn trans_impl(ccx: @CrateContext,
 /// * `method`: the AST node for the method
 /// * `param_substs`: if this is a generic method, the current values for
 ///   type parameters and so forth, else none
-/// * `llfn`: the LLVM ValueRef for the method
+/// * `llfn`: a closure returning the LLVM ValueRef for the method
 /// * `impl_id`: the node ID of the impl this method is inside
 ///
 /// XXX(pcwalton) Can we take `path` by reference?
@@ -99,12 +99,10 @@ pub fn trans_method(ccx: @CrateContext,
                     path: Path,
                     method: &ast::Method,
                     param_substs: Option<@param_substs>,
-                    llfn: ValueRef) {
+                    llfn_with_self: |Option<ty::t>| -> ValueRef) -> ValueRef {
     // figure out how self is being passed
-    let self_arg = match method.explicit_self.node {
-      ast::SelfStatic => {
-        no_self
-      }
+    let self_ty = match method.explicit_self.node {
+      ast::SelfStatic => None,
       _ => {
         // determine the (monomorphized) type that `self` maps to for
         // this method
@@ -115,43 +113,25 @@ pub fn trans_method(ccx: @CrateContext,
                 ty::subst_tps(ccx.tcx, *tys, *self_sub, self_ty)
             }
         };
-        debug!("calling trans_fn with self_ty {}",
-               self_ty.repr(ccx.tcx));
-        match method.explicit_self.node {
-          ast::SelfValue(_) => impl_self(self_ty, ty::ByRef),
-          _ => impl_self(self_ty, ty::ByCopy),
-        }
+        debug!("calling trans_fn with self_ty {}", self_ty.repr(ccx.tcx));
+        Some(self_ty)
       }
     };
 
+    let llfn = llfn_with_self(self_ty);
+
     // generate the actual code
     trans_fn(ccx,
              path,
              method.decl,
              method.body,
              llfn,
-             self_arg,
+             self_ty,
              param_substs,
              method.id,
+             Some(method),
              []);
-}
-
-pub fn trans_self_arg<'a>(
-                      bcx: &'a Block<'a>,
-                      base: &ast::Expr,
-                      temp_cleanups: &mut ~[ValueRef],
-                      mentry: typeck::method_map_entry)
-                      -> Result<'a> {
-    let _icx = push_ctxt("impl::trans_self_arg");
-
-    // self is passed as an opaque box in the environment slot
-    let self_ty = ty::mk_opaque_box(bcx.tcx());
-    trans_arg_expr(bcx,
-                   self_ty,
-                   mentry.self_mode,
-                   base,
-                   temp_cleanups,
-                   DontAutorefArg)
+    llfn
 }
 
 pub fn trans_method_callee<'a>(
@@ -169,16 +149,23 @@ pub fn trans_method_callee<'a>(
 
     match mentry.origin {
         typeck::method_static(did) => {
-            let callee_fn = callee::trans_fn_ref(bcx, did, callee_id);
+            let self_ty = monomorphize_type(bcx, mentry.self_ty);
             let mut temp_cleanups = ~[];
-            let Result {bcx, val} = trans_self_arg(bcx, this, &mut temp_cleanups, mentry);
+            let Result {bcx, val} = trans_arg_expr(bcx, self_ty, this,
+                                                   &mut temp_cleanups,
+                                                   DontAutorefArg);
+            // HACK should not need the pointer cast, eventually trans_fn_ref
+            // should return a function type with the right type for self.
+            let callee_fn = callee::trans_fn_ref(bcx, did, callee_id);
+            let fn_ty = node_id_type(bcx, callee_id);
+            let llfn_ty = type_of_fn_from_ty(bcx.ccx(), Some(self_ty), fn_ty).ptr_to();
+            let llfn_val = PointerCast(bcx, callee_fn.llfn, llfn_ty);
             Callee {
                 bcx: bcx,
                 data: Method(MethodData {
-                    llfn: callee_fn.llfn,
+                    llfn: llfn_val,
                     llself: val,
-                    temp_cleanup: temp_cleanups.head_opt().map(|v| *v),
-                    self_mode: mentry.self_mode,
+                    temp_cleanup: temp_cleanups.head_opt().map(|v| *v)
                 })
             }
         }
@@ -194,8 +181,7 @@ pub fn trans_method_callee<'a>(
                         bcx.tcx(),
                         trait_id);
 
-                    let vtbl = find_vtable(bcx.tcx(), substs,
-                                           p, b);
+                    let vtbl = find_vtable(bcx.tcx(), substs, p, b);
                     trans_monomorphized_callee(bcx, callee_id, this, mentry,
                                                trait_id, off, vtbl)
                 }
@@ -276,7 +262,7 @@ pub fn trans_static_method_callee(bcx: &Block,
         typeck::vtable_static(impl_did, ref rcvr_substs, rcvr_origins) => {
             assert!(rcvr_substs.iter().all(|t| !ty::type_needs_infer(*t)));
 
-            let mth_id = method_with_name(bcx.ccx(), impl_did, mname.name);
+            let mth_id = method_with_name(ccx, impl_did, mname.name);
             let (callee_substs, callee_origins) =
                 combine_impl_and_methods_tps(
                     bcx, mth_id, callee_id,
@@ -290,7 +276,7 @@ pub fn trans_static_method_callee(bcx: &Block,
                                           Some(callee_origins));
 
             let callee_ty = node_id_type(bcx, callee_id);
-            let llty = type_of_fn_from_ty(ccx, callee_ty).ptr_to();
+            let llty = type_of_fn_from_ty(ccx, None, callee_ty).ptr_to();
             FnData {llfn: PointerCast(bcx, lval, llty)}
         }
         _ => {
@@ -340,9 +326,11 @@ pub fn trans_monomorphized_callee<'a>(
           let mth_id = method_with_name(bcx.ccx(), impl_did, mname.name);
 
           // obtain the `self` value:
+          let self_ty = monomorphize_type(bcx, mentry.self_ty);
           let mut temp_cleanups = ~[];
-          let Result {bcx, val: llself_val} =
-              trans_self_arg(bcx, base, &mut temp_cleanups, mentry);
+          let Result {bcx, val} = trans_arg_expr(bcx, self_ty, base,
+                                                 &mut temp_cleanups,
+                                                 DontAutorefArg);
 
           // create a concatenated set of substitutions which includes
           // those from the impl and those from the method:
@@ -359,8 +347,9 @@ pub fn trans_monomorphized_callee<'a>(
                                                  Some(callee_origins));
 
           // create a llvalue that represents the fn ptr
+          // HACK should not need the pointer cast (add self in trans_fn_ref_with_vtables).
           let fn_ty = node_id_type(bcx, callee_id);
-          let llfn_ty = type_of_fn_from_ty(ccx, fn_ty).ptr_to();
+          let llfn_ty = type_of_fn_from_ty(ccx, Some(self_ty), fn_ty).ptr_to();
           let llfn_val = PointerCast(bcx, callee.llfn, llfn_ty);
 
           // combine the self environment with the rest
@@ -368,9 +357,8 @@ pub fn trans_monomorphized_callee<'a>(
               bcx: bcx,
               data: Method(MethodData {
                   llfn: llfn_val,
-                  llself: llself_val,
-                  temp_cleanup: temp_cleanups.head_opt().map(|v| *v),
-                  self_mode: mentry.self_mode,
+                  llself: val,
+                  temp_cleanup: temp_cleanups.head_opt().map(|v| *v)
               })
           }
       }
@@ -496,7 +484,7 @@ pub fn trans_trait_callee_from_llval<'a>(
 
     // Load the function from the vtable and cast it to the expected type.
     debug!("(translating trait callee) loading method");
-    let llcallee_ty = type_of_fn_from_ty(ccx, callee_ty);
+    let llcallee_ty = type_of_fn_from_ty(ccx, None, callee_ty);
     let llvtable = Load(bcx,
                         PointerCast(bcx,
                                     GEPi(bcx, llpair,
@@ -510,12 +498,7 @@ pub fn trans_trait_callee_from_llval<'a>(
         data: Method(MethodData {
             llfn: mptr,
             llself: llself,
-            temp_cleanup: temp_cleanup,
-
-                // We know that the func declaration is &self, ~self,
-                // or @self, and such functions are always by-copy
-                // (right now, at least).
-            self_mode: ty::ByCopy,
+            temp_cleanup: temp_cleanup
         })
     };
 }
diff --git a/src/librustc/middle/trans/monomorphize.rs b/src/librustc/middle/trans/monomorphize.rs
index 8365b541532..c7bf618a619 100644
--- a/src/librustc/middle/trans/monomorphize.rs
+++ b/src/librustc/middle/trans/monomorphize.rs
@@ -13,9 +13,8 @@ use back::link::mangle_exported_name;
 use driver::session;
 use lib::llvm::ValueRef;
 use middle::trans::base::{set_llvm_fn_attrs, set_inline_hint};
-use middle::trans::base::{trans_enum_variant,push_ctxt};
+use middle::trans::base::{trans_enum_variant, push_ctxt, get_item_val};
 use middle::trans::base::{trans_fn, decl_internal_rust_fn};
-use middle::trans::base::{get_item_val, no_self};
 use middle::trans::base;
 use middle::trans::common::*;
 use middle::trans::meth;
@@ -211,8 +210,8 @@ pub fn monomorphic_fn(ccx: @CrateContext,
     let s = mangle_exported_name(ccx, pt.clone(), mono_ty);
     debug!("monomorphize_fn mangled to {}", s);
 
-    let mk_lldecl = || {
-        let lldecl = decl_internal_rust_fn(ccx, f.sig.inputs, f.sig.output, s);
+    let mk_lldecl = |self_ty| {
+        let lldecl = decl_internal_rust_fn(ccx, self_ty, f.sig.inputs, f.sig.output, s);
         let mut monomorphized = ccx.monomorphized.borrow_mut();
         monomorphized.get().insert(hash_id, lldecl);
         lldecl
@@ -223,16 +222,17 @@ pub fn monomorphic_fn(ccx: @CrateContext,
                 node: ast::ItemFn(decl, _, _, _, body),
                 ..
             }, _) => {
-        let d = mk_lldecl();
+        let d = mk_lldecl(None);
         set_llvm_fn_attrs(i.attrs, d);
         trans_fn(ccx,
                  pt,
                  decl,
                  body,
                  d,
-                 no_self,
+                 None,
                  Some(psubsts),
                  fn_id.node,
+                 None,
                  []);
         d
       }
@@ -240,7 +240,7 @@ pub fn monomorphic_fn(ccx: @CrateContext,
           ccx.tcx.sess.bug("Can't monomorphize this kind of item")
       }
       ast_map::NodeForeignItem(i, _, _, _) => {
-          let d = mk_lldecl();
+          let d = mk_lldecl(None);
           intrinsic::trans_intrinsic(ccx, d, i, pt, psubsts, i.attrs,
                                      ref_id);
           d
@@ -248,7 +248,7 @@ pub fn monomorphic_fn(ccx: @CrateContext,
       ast_map::NodeVariant(v, enum_item, _) => {
         let tvs = ty::enum_variants(ccx.tcx, local_def(enum_item.id));
         let this_tv = *tvs.iter().find(|tv| { tv.id.node == fn_id.node}).unwrap();
-        let d = mk_lldecl();
+        let d = mk_lldecl(None);
         set_inline_hint(d);
         match v.node.kind {
             ast::TupleVariantKind(ref args) => {
@@ -266,20 +266,21 @@ pub fn monomorphic_fn(ccx: @CrateContext,
         d
       }
       ast_map::NodeMethod(mth, _, _) => {
-        // XXX: What should the self type be here?
-        let d = mk_lldecl();
-        set_llvm_fn_attrs(mth.attrs, d);
-        meth::trans_method(ccx, pt, mth, Some(psubsts), d);
-        d
+        meth::trans_method(ccx, pt, mth, Some(psubsts), |self_ty| {
+            let d = mk_lldecl(self_ty);
+            set_llvm_fn_attrs(mth.attrs, d);
+            d
+        })
       }
       ast_map::NodeTraitMethod(@ast::Provided(mth), _, pt) => {
-        let d = mk_lldecl();
-        set_llvm_fn_attrs(mth.attrs, d);
-        meth::trans_method(ccx, (*pt).clone(), mth, Some(psubsts), d);
-        d
+        meth::trans_method(ccx, (*pt).clone(), mth, Some(psubsts), |self_ty| {
+            let d = mk_lldecl(self_ty);
+            set_llvm_fn_attrs(mth.attrs, d);
+            d
+        })
       }
       ast_map::NodeStructCtor(struct_def, _, _) => {
-        let d = mk_lldecl();
+        let d = mk_lldecl(None);
         set_inline_hint(d);
         base::trans_tuple_struct(ccx,
                                  struct_def.fields,
diff --git a/src/librustc/middle/trans/reflect.rs b/src/librustc/middle/trans/reflect.rs
index 849fc18ac01..ef9f48d4785 100644
--- a/src/librustc/middle/trans/reflect.rs
+++ b/src/librustc/middle/trans/reflect.rs
@@ -295,7 +295,7 @@ impl<'a> Reflector<'a> {
                                                                sub_path,
                                                                "get_disr");
 
-                let llfdecl = decl_internal_rust_fn(ccx, [opaqueptrty], ty::mk_u64(), sym);
+                let llfdecl = decl_internal_rust_fn(ccx, None, [opaqueptrty], ty::mk_u64(), sym);
                 let fcx = new_fn_ctxt(ccx,
                                       ~[],
                                       llfdecl,
@@ -362,7 +362,6 @@ impl<'a> Reflector<'a> {
           }
           ty::ty_self(..) => self.leaf("self"),
           ty::ty_type => self.leaf("type"),
-          ty::ty_opaque_box => self.leaf("opaque_box"),
           ty::ty_opaque_closure_ptr(ck) => {
               let ckval = ast_sigil_constant(ck);
               let extra = ~[self.c_uint(ckval)];
diff --git a/src/librustc/middle/trans/type_of.rs b/src/librustc/middle/trans/type_of.rs
index 8ac35c9e04b..f59c2acd027 100644
--- a/src/librustc/middle/trans/type_of.rs
+++ b/src/librustc/middle/trans/type_of.rs
@@ -44,6 +44,7 @@ pub fn type_of_explicit_args(ccx: &CrateContext,
 }
 
 pub fn type_of_rust_fn(cx: &CrateContext,
+                       self_ty: Option<ty::t>,
                        inputs: &[ty::t],
                        output: ty::t) -> Type {
     let mut atys: ~[Type] = ~[];
@@ -57,7 +58,11 @@ pub fn type_of_rust_fn(cx: &CrateContext,
     }
 
     // Arg 1: Environment
-    atys.push(Type::opaque_box(cx).ptr_to());
+    let env = match self_ty {
+        Some(t) => type_of_explicit_arg(cx, t),
+        None => Type::opaque_box(cx).ptr_to()
+    };
+    atys.push(env);
 
     // ... then explicit args.
     atys.push_all(type_of_explicit_args(cx, inputs));
@@ -71,14 +76,14 @@ pub fn type_of_rust_fn(cx: &CrateContext,
 }
 
 // Given a function type and a count of ty params, construct an llvm type
-pub fn type_of_fn_from_ty(cx: &CrateContext, fty: ty::t) -> Type {
+pub fn type_of_fn_from_ty(cx: &CrateContext, self_ty: Option<ty::t>, fty: ty::t) -> Type {
     return match ty::get(fty).sty {
         ty::ty_closure(ref f) => {
-            type_of_rust_fn(cx, f.sig.inputs, f.sig.output)
+            type_of_rust_fn(cx, None, f.sig.inputs, f.sig.output)
         }
         ty::ty_bare_fn(ref f) => {
             if f.abis.is_rust() || f.abis.is_intrinsic() {
-                type_of_rust_fn(cx, f.sig.inputs, f.sig.output)
+                type_of_rust_fn(cx, self_ty, f.sig.inputs, f.sig.output)
             } else {
                 foreign::lltype_for_foreign_fn(cx, fty)
             }
@@ -122,7 +127,6 @@ pub fn sizing_type_of(cx: &CrateContext, t: ty::t) -> Type {
         ty::ty_vec(_, ty::vstore_uniq) |
         ty::ty_vec(_, ty::vstore_box) |
         ty::ty_box(..) |
-        ty::ty_opaque_box |
         ty::ty_uniq(..) |
         ty::ty_ptr(..) |
         ty::ty_rptr(..) |
@@ -240,7 +244,6 @@ pub fn type_of(cx: &CrateContext, t: ty::t) -> Type {
           let ty = type_of(cx, typ);
           Type::smart_ptr(cx, &ty).ptr_to()
       }
-      ty::ty_opaque_box => Type::opaque_box(cx).ptr_to(),
       ty::ty_uniq(ref mt) => {
           let ty = type_of(cx, mt.ty);
           if ty::type_contents(cx.tcx, mt.ty).owns_managed() {
@@ -285,10 +288,10 @@ pub fn type_of(cx: &CrateContext, t: ty::t) -> Type {
       }
 
       ty::ty_bare_fn(_) => {
-          type_of_fn_from_ty(cx, t).ptr_to()
+          type_of_fn_from_ty(cx, None, t).ptr_to()
       }
       ty::ty_closure(_) => {
-          let ty = type_of_fn_from_ty(cx, t);
+          let ty = type_of_fn_from_ty(cx, None, t);
           Type::func_pair(cx, &ty)
       }
       ty::ty_trait(_, _, store, _, _) => Type::opaque_trait(cx, store),
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 70abc13775f..46dc1bb68b3 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -151,14 +151,6 @@ pub enum TraitStore {
     RegionTraitStore(Region),   // &Trait
 }
 
-// XXX: This should probably go away at some point. Maybe after destructors
-// do?
-#[deriving(Clone, Eq, Encodable, Decodable)]
-pub enum SelfMode {
-    ByCopy,
-    ByRef,
-}
-
 pub struct field_ty {
     name: Name,
     id: DefId,
@@ -659,8 +651,7 @@ pub enum sty {
 
     // "Fake" types, used for trans purposes
     ty_type, // type_desc*
-    ty_opaque_box, // used by monomorphizer to represent any @ box
-    ty_opaque_closure_ptr(Sigil), // ptr to env for ||, @fn, ~fn
+    ty_opaque_closure_ptr(Sigil), // ptr to env for || and proc
     ty_unboxed_vec(mt),
 }
 
@@ -1078,8 +1069,7 @@ pub fn mk_t(cx: ctxt, st: sty) -> t {
         flags |= get(mt.ty).flags;
       }
       &ty_nil | &ty_bool | &ty_char | &ty_int(_) | &ty_float(_) | &ty_uint(_) |
-      &ty_str(_) | &ty_type | &ty_opaque_closure_ptr(_) |
-      &ty_opaque_box => (),
+      &ty_str(_) | &ty_type | &ty_opaque_closure_ptr(_) => {}
       // You might think that we could just return ty_err for
       // any type containing ty_err as a component, and get
       // rid of the has_ty_err flag -- likewise for ty_bot (with
@@ -1354,8 +1344,6 @@ pub fn mk_opaque_closure_ptr(cx: ctxt, sigil: ast::Sigil) -> t {
     mk_t(cx, ty_opaque_closure_ptr(sigil))
 }
 
-pub fn mk_opaque_box(cx: ctxt) -> t { mk_t(cx, ty_opaque_box) }
-
 pub fn walk_ty(ty: t, f: |t|) {
     maybe_walk_ty(ty, |t| { f(t); true });
 }
@@ -1366,12 +1354,9 @@ pub fn maybe_walk_ty(ty: t, f: |t| -> bool) {
     }
     match get(ty).sty {
       ty_nil | ty_bot | ty_bool | ty_char | ty_int(_) | ty_uint(_) | ty_float(_) |
-      ty_str(_) | ty_type | ty_opaque_box | ty_self(_) |
-      ty_opaque_closure_ptr(_) | ty_infer(_) | ty_param(_) | ty_err => {
-      }
-      ty_box(ref ty) => {
-        maybe_walk_ty(*ty, f);
-      }
+      ty_str(_) | ty_type | ty_self(_) |
+      ty_opaque_closure_ptr(_) | ty_infer(_) | ty_param(_) | ty_err => {}
+      ty_box(ref ty) => maybe_walk_ty(*ty, f),
       ty_vec(ref tm, _) | ty_unboxed_vec(ref tm) | ty_ptr(ref tm) |
       ty_rptr(_, ref tm) | ty_uniq(ref tm) => {
         maybe_walk_ty(tm.ty, f);
@@ -1592,8 +1577,7 @@ pub fn type_is_box(ty: t) -> bool {
 
 pub fn type_is_boxed(ty: t) -> bool {
     match get(ty).sty {
-      ty_box(_) | ty_opaque_box |
-      ty_vec(_, vstore_box) | ty_str(vstore_box) => true,
+      ty_box(_) | ty_vec(_, vstore_box) | ty_str(vstore_box) => true,
       _ => false
     }
 }
@@ -1699,7 +1683,7 @@ fn type_needs_unwind_cleanup_(cx: ctxt, ty: t,
     maybe_walk_ty(ty, |ty| {
         let old_encountered_box = encountered_box;
         let result = match get(ty).sty {
-          ty_box(_) | ty_opaque_box => {
+          ty_box(_) => {
             encountered_box = true;
             true
           }
@@ -2145,8 +2129,6 @@ pub fn type_contents(cx: ctxt, ty: t) -> TypeContents {
                 // times.
                 TC::All
             }
-
-            ty_opaque_box => TC::Managed,
             ty_unboxed_vec(mt) => TC::InteriorUnsized | tc_mt(cx, mt, cache),
             ty_opaque_closure_ptr(sigil) => {
                 match sigil {
@@ -2332,7 +2314,6 @@ pub fn is_instantiable(cx: ctxt, r_ty: t) -> bool {
             ty_param(_) |
             ty_self(_) |
             ty_type |
-            ty_opaque_box |
             ty_opaque_closure_ptr(_) |
             ty_vec(_, _) |
             ty_unboxed_vec(_) => {
@@ -2515,7 +2496,7 @@ pub fn type_is_pod(cx: ctxt, ty: t) -> bool {
       ty_box(_) | ty_uniq(_) | ty_closure(_) |
       ty_str(vstore_uniq) | ty_str(vstore_box) |
       ty_vec(_, vstore_uniq) | ty_vec(_, vstore_box) |
-      ty_trait(_, _, _, _, _) | ty_rptr(_,_) | ty_opaque_box => result = false,
+      ty_trait(_, _, _, _, _) | ty_rptr(_,_) => result = false,
       // Structural types
       ty_enum(did, ref substs) => {
         let variants = enum_variants(cx, did);
@@ -3345,7 +3326,7 @@ pub fn ty_sort_str(cx: ctxt, t: t) -> ~str {
     match get(t).sty {
       ty_nil | ty_bot | ty_bool | ty_char | ty_int(_) |
       ty_uint(_) | ty_float(_) | ty_str(_) |
-      ty_type | ty_opaque_box | ty_opaque_closure_ptr(_) => {
+      ty_type | ty_opaque_closure_ptr(_) => {
         ::util::ppaux::ty_to_str(cx, t)
       }
 
@@ -4890,13 +4871,12 @@ pub fn hash_crate_independent(tcx: ctxt, t: t, local_hash: @str) -> u64 {
             ty_infer(_) => unreachable!(),
             ty_err => hash.input([23]),
             ty_type => hash.input([24]),
-            ty_opaque_box => hash.input([25]),
             ty_opaque_closure_ptr(s) => {
-                hash.input([26]);
+                hash.input([25]);
                 iter(&mut hash, &s);
             }
             ty_unboxed_vec(m) => {
-                hash.input([27]);
+                hash.input([26]);
                 mt(&mut hash, m);
             }
         }
diff --git a/src/librustc/middle/ty_fold.rs b/src/librustc/middle/ty_fold.rs
index eb854adf4a8..bd1f091b9d6 100644
--- a/src/librustc/middle/ty_fold.rs
+++ b/src/librustc/middle/ty_fold.rs
@@ -190,7 +190,7 @@ pub fn super_fold_sty<T:TypeFolder>(this: &mut T,
         ty::ty_int(_) | ty::ty_uint(_) |
         ty::ty_float(_) | ty::ty_type |
         ty::ty_opaque_closure_ptr(_) |
-        ty::ty_err | ty::ty_opaque_box | ty::ty_infer(_) |
+        ty::ty_err | ty::ty_infer(_) |
         ty::ty_param(..) | ty::ty_self(_) => {
             (*sty).clone()
         }
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index f6ee7538b5b..00f8eb6daeb 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -791,7 +791,7 @@ impl<'a> LookupContext<'a> {
             ty_err => None,
 
             ty_opaque_closure_ptr(_) | ty_unboxed_vec(_) |
-            ty_opaque_box | ty_type | ty_infer(TyVar(_)) => {
+            ty_type | ty_infer(TyVar(_)) => {
                 self.bug(format!("Unexpected type: {}",
                               self.ty_to_str(self_ty)));
             }
@@ -1020,8 +1020,6 @@ impl<'a> LookupContext<'a> {
         });
         debug!("after replacing bound regions, fty={}", self.ty_to_str(fty));
 
-        let self_mode = get_mode_from_explicit_self(candidate.method_ty.explicit_self);
-
         // before we only checked whether self_ty could be a subtype
         // of rcvr_ty; now we actually make it so (this may cause
         // variables to unify etc).  Since we checked beforehand, and
@@ -1041,7 +1039,6 @@ impl<'a> LookupContext<'a> {
         self.fcx.write_substs(self.callee_id, all_substs);
         method_map_entry {
             self_ty: transformed_self_ty,
-            self_mode: self_mode,
             explicit_self: candidate.method_ty.explicit_self,
             origin: candidate.origin,
         }
@@ -1375,13 +1372,6 @@ impl<'a> LookupContext<'a> {
     }
 }
 
-pub fn get_mode_from_explicit_self(explicit_self: ast::ExplicitSelf_) -> SelfMode {
-    match explicit_self {
-        SelfValue(_) => ty::ByRef,
-        _ => ty::ByCopy,
-    }
-}
-
 impl Repr for RcvrMatchCondition {
     fn repr(&self, tcx: ty::ctxt) -> ~str {
         match *self {
diff --git a/src/librustc/middle/typeck/coherence.rs b/src/librustc/middle/typeck/coherence.rs
index 342e5a1ad2a..6e944e82a02 100644
--- a/src/librustc/middle/typeck/coherence.rs
+++ b/src/librustc/middle/typeck/coherence.rs
@@ -21,7 +21,7 @@ use middle::ty::get;
 use middle::ty::{ImplContainer, lookup_item_type, subst};
 use middle::ty::{substs, t, ty_bool, ty_char, ty_bot, ty_box, ty_enum, ty_err};
 use middle::ty::{ty_str, ty_vec, ty_float, ty_infer, ty_int, ty_nil};
-use middle::ty::{ty_opaque_box, ty_param, ty_param_bounds_and_ty, ty_ptr};
+use middle::ty::{ty_param, ty_param_bounds_and_ty, ty_ptr};
 use middle::ty::{ty_rptr, ty_self, ty_struct, ty_trait, ty_tup};
 use middle::ty::{ty_type, ty_uint, ty_uniq, ty_bare_fn, ty_closure};
 use middle::ty::{ty_opaque_closure_ptr, ty_unboxed_vec};
@@ -83,7 +83,7 @@ pub fn get_base_type(inference_context: @InferCtxt,
 
         ty_nil | ty_bot | ty_bool | ty_char | ty_int(..) | ty_uint(..) | ty_float(..) |
         ty_str(..) | ty_vec(..) | ty_bare_fn(..) | ty_closure(..) | ty_tup(..) |
-        ty_infer(..) | ty_param(..) | ty_self(..) | ty_type | ty_opaque_box |
+        ty_infer(..) | ty_param(..) | ty_self(..) | ty_type |
         ty_opaque_closure_ptr(..) | ty_unboxed_vec(..) | ty_err | ty_box(_) |
         ty_uniq(_) | ty_ptr(_) | ty_rptr(_, _) => {
             debug!("(getting base type) no base type; found {:?}",
diff --git a/src/librustc/middle/typeck/mod.rs b/src/librustc/middle/typeck/mod.rs
index d3f075774c5..0a7f7303a37 100644
--- a/src/librustc/middle/typeck/mod.rs
+++ b/src/librustc/middle/typeck/mod.rs
@@ -148,9 +148,6 @@ pub struct method_map_entry {
     // (FIXME #3446)
     self_ty: ty::t,
 
-    // the mode of `self`
-    self_mode: ty::SelfMode,
-
     // the type of explicit self on the method
     explicit_self: ast::ExplicitSelf_,
 
diff --git a/src/librustc/middle/typeck/variance.rs b/src/librustc/middle/typeck/variance.rs
index cfad864323b..509836512c0 100644
--- a/src/librustc/middle/typeck/variance.rs
+++ b/src/librustc/middle/typeck/variance.rs
@@ -693,8 +693,7 @@ impl<'a> ConstraintContext<'a> {
             }
 
             ty::ty_infer(..) | ty::ty_err | ty::ty_type |
-            ty::ty_opaque_box | ty::ty_opaque_closure_ptr(..) |
-            ty::ty_unboxed_vec(..) => {
+            ty::ty_opaque_closure_ptr(..) | ty::ty_unboxed_vec(..) => {
                 self.tcx().sess.bug(
                     format!("Unexpected type encountered in \
                             variance inference: {}",
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index 08b38c5b50f..84dece87750 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -18,7 +18,7 @@ use middle::ty::{ReFree, ReScope, ReInfer, ReStatic, Region,
                  ReEmpty};
 use middle::ty::{ty_bool, ty_char, ty_bot, ty_box, ty_struct, ty_enum};
 use middle::ty::{ty_err, ty_str, ty_vec, ty_float, ty_bare_fn, ty_closure};
-use middle::ty::{ty_nil, ty_opaque_box, ty_opaque_closure_ptr, ty_param};
+use middle::ty::{ty_nil, ty_opaque_closure_ptr, ty_param};
 use middle::ty::{ty_ptr, ty_rptr, ty_self, ty_tup, ty_type, ty_uniq};
 use middle::ty::{ty_trait, ty_int};
 use middle::ty::{ty_uint, ty_unboxed_vec, ty_infer};
@@ -505,7 +505,6 @@ pub fn ty_to_str(cx: ctxt, typ: t) -> ~str {
         vstore_ty_to_str(cx, mt, vs)
       }
       ty_str(vs) => format!("{}{}", vstore_to_str(cx, vs), "str"),
-      ty_opaque_box => ~"@?",
       ty_opaque_closure_ptr(ast::BorrowedSigil) => ~"&closure",
       ty_opaque_closure_ptr(ast::ManagedSigil) => ~"@closure",
       ty_opaque_closure_ptr(ast::OwnedSigil) => ~"~closure",
diff --git a/src/test/run-pass/self-in-mut-slot-immediate-value.rs b/src/test/run-pass/self-in-mut-slot-immediate-value.rs
new file mode 100644
index 00000000000..f2482474073
--- /dev/null
+++ b/src/test/run-pass/self-in-mut-slot-immediate-value.rs
@@ -0,0 +1,30 @@
+// 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.
+
+// Assert that `mut self` on an immediate value doesn't
+// allow mutating the original - issue #10615.
+
+struct Value {
+    n: int
+}
+
+impl Value {
+    fn squared(mut self) -> Value {
+        self.n *= self.n;
+        self
+    }
+}
+
+pub fn main() {
+    let x = Value { n: 3 };
+    let y = x.squared();
+    assert_eq!(x.n, 3);
+    assert_eq!(y.n, 9);
+}