librustc: Fix explicit self for objects in more cases. r=nmatsakis

src/librustc/middle/trans/meth.rs

@@ -550,8 +550,16 @@ fn trans_trait_callee(bcx: block,
 
     let _icx = bcx.insn_ctxt("impl::trans_trait_callee");
     let mut bcx = bcx;
-    let self_datum = unpack_datum!(bcx, expr::trans_to_datum(bcx, self_expr));
+    let self_datum = unpack_datum!(bcx,
+        expr::trans_to_datum(bcx, self_expr));
     let llpair = self_datum.to_ref_llval(bcx);
+
+    let llpair = match explicit_self {
+        ast::sty_region(_) => Load(bcx, llpair),
+        ast::sty_static | ast::sty_by_ref | ast::sty_value |
+        ast::sty_box(_) | ast::sty_uniq(_) => llpair
+    };
+
     let callee_ty = node_id_type(bcx, callee_id);
     trans_trait_callee_from_llval(bcx,
                                   callee_ty,

src/librustc/middle/typeck/check/method.rs

@@ -153,12 +153,12 @@ struct Candidate {
 }
 
 /**
- * Whether the self type should be transformed according to the form of
- * explicit self provided by the method.
+ * How the self type should be transformed according to the form of explicit
+ * self provided by the method.
  */
 enum TransformTypeFlag {
-    DontTransformType,
-    TransformType
+    TransformTypeNormally,
+    TransformTypeForObject,
 }
 
 impl LookupContext {
@@ -327,7 +327,8 @@ impl LookupContext {
         }
     }
 
-    fn push_inherent_candidates_from_param(&self, rcvr_ty: ty::t,
+    fn push_inherent_candidates_from_param(&self,
+                                           rcvr_ty: ty::t,
                                            param_ty: param_ty) {
         debug!("push_inherent_candidates_from_param(param_ty=%?)",
                param_ty);
@@ -426,7 +427,7 @@ impl LookupContext {
                         method.self_ty,
                         rcvr_ty,
                         move init_substs,
-                        TransformType);
+                        TransformTypeNormally);
 
                 let cand = Candidate {
                     rcvr_ty: rcvr_ty,
@@ -488,7 +489,7 @@ impl LookupContext {
             self.create_rcvr_ty_and_substs_for_method(method.self_ty,
                                                       self_ty,
                                                       move rcvr_substs,
-                                                      DontTransformType);
+                                                      TransformTypeForObject);
 
         self.inherent_candidates.push(Candidate {
             rcvr_ty: rcvr_ty,
@@ -519,7 +520,7 @@ impl LookupContext {
                 method.self_ty,
                 self_ty,
                 move rcvr_substs,
-                TransformType);
+                TransformTypeNormally);
 
         self.inherent_candidates.push(Candidate {
             rcvr_ty: rcvr_ty,
@@ -574,7 +575,7 @@ impl LookupContext {
                 method.self_type,
                 impl_ty,
                 move impl_substs,
-                TransformType);
+                TransformTypeNormally);
 
         candidates.push(Candidate {
             rcvr_ty: impl_ty,
@@ -610,7 +611,7 @@ impl LookupContext {
                     provided_method_info.method_info.self_type,
                     self_ty,
                     dummy_substs,
-                    TransformType);
+                    TransformTypeNormally);
 
             candidates.push(Candidate {
                 rcvr_ty: impl_ty,
@@ -658,18 +659,11 @@ impl LookupContext {
             }
         };
 
-        let rcvr_ty;
-        match transform_type {
-            TransformType => {
-                rcvr_ty = transform_self_type_for_method(self.tcx(),
-                                                         rcvr_substs.self_r,
-                                                         self_ty,
-                                                         self_decl);
-            }
-            DontTransformType => {
-                rcvr_ty = self_ty;
-            }
-        }
+        let rcvr_ty = transform_self_type_for_method(self.tcx(),
+                                                     rcvr_substs.self_r,
+                                                     self_ty,
+                                                     self_decl,
+                                                     transform_type);
 
         (rcvr_ty, rcvr_substs)
     }
@@ -686,6 +680,10 @@ impl LookupContext {
         match self.search_for_method(self_ty) {
             None => None,
             Some(move mme) => {
+                debug!("(searching for autoderef'd method) writing \
+                       adjustment (%u) to %d",
+                       autoderefs,
+                       self.self_expr.id);
                 self.fcx.write_autoderef_adjustment(
                     self.self_expr.id, autoderefs);
                 Some(mme)
@@ -814,25 +812,12 @@ impl LookupContext {
             match self.search_for_method(autoref_ty) {
                 None => {}
                 Some(move mme) => {
-                    match mme.origin {
-                        method_trait(*) => {
-                            // Do not write adjustments; they make no sense
-                            // here since the adjustments are to be performed
-                            // on the self element of the object pair/triple,
-                            // not the object itself.
-                            //
-                            // FIXME (#4088): This is wrong in the presence
-                            // of autoderef.
-                        }
-                        _ => {
-                            self.fcx.write_adjustment(
-                                self.self_expr.id,
-                                @{autoderefs: autoderefs,
-                                  autoref: Some({kind: kind,
-                                                 region: region,
-                                                 mutbl: *mutbl})});
-                        }
-                    }
+                    self.fcx.write_adjustment(
+                        self.self_expr.id,
+                        @{autoderefs: autoderefs,
+                          autoref: Some({kind: kind,
+                                         region: region,
+                                         mutbl: *mutbl})});
                     return Some(mme);
                 }
             }
@@ -1162,9 +1147,9 @@ impl LookupContext {
 fn transform_self_type_for_method(tcx: ty::ctxt,
                                   self_region: Option<ty::Region>,
                                   impl_ty: ty::t,
-                                  self_type: ast::self_ty_)
-    -> ty::t
-{
+                                  self_type: ast::self_ty_,
+                                  flag: TransformTypeFlag)
+                               -> ty::t {
     match self_type {
       sty_static => {
         tcx.sess.bug(~"calling transform_self_type_for_method on \
@@ -1179,10 +1164,20 @@ fn transform_self_type_for_method(tcx: ty::ctxt,
                 { ty: impl_ty, mutbl: mutability })
       }
       sty_box(mutability) => {
-        mk_box(tcx, { ty: impl_ty, mutbl: mutability })
+        match flag {
+            TransformTypeNormally => {
+                mk_box(tcx, { ty: impl_ty, mutbl: mutability })
+            }
+            TransformTypeForObject => impl_ty
+        }
       }
       sty_uniq(mutability) => {
-        mk_uniq(tcx, { ty: impl_ty, mutbl: mutability })
+        match flag {
+            TransformTypeNormally => {
+                mk_uniq(tcx, { ty: impl_ty, mutbl: mutability })
+            }
+            TransformTypeForObject => impl_ty
+        }
       }
     }
 }

src/librustc/middle/typeck/check/mod.rs

@@ -79,6 +79,7 @@ type parameter).
 use middle::ty::{TyVid, vid, FnTyBase, FnMeta, FnSig, VariantInfo_};
 use middle::typeck::astconv::{ast_conv, ast_path_to_ty};
 use middle::typeck::astconv::{ast_region_to_region, ast_ty_to_ty};
+use middle::typeck::check::method::TransformTypeNormally;
 use middle::typeck::check::regionmanip::replace_bound_regions_in_fn_ty;
 use middle::typeck::check::vtable::{LocationInfo, VtableContext};
 use middle::typeck::infer::{resolve_type, force_tvar};
@@ -318,8 +319,11 @@ fn check_fn(ccx: @crate_ctxt,
         } else  {
             let self_region = fcx.in_scope_regions.find(ty::br_self);
             let ty = method::transform_self_type_for_method(
-                fcx.tcx(), self_region,
-                self_info.self_ty, self_info.explicit_self.node);
+                fcx.tcx(),
+                self_region,
+                self_info.self_ty,
+                self_info.explicit_self.node,
+                TransformTypeNormally);
             Some({self_ty: ty,.. *self_info})
         }
     };

src/test/run-pass/explicit-self-objects-ext-1.rs

@@ -0,0 +1,39 @@
+pub trait Reader {
+    // FIXME (#2004): Seekable really should be orthogonal.
+
+    /// Read up to len bytes (or EOF) and put them into bytes (which
+    /// must be at least len bytes long). Return number of bytes read.
+    // FIXME (#2982): This should probably return an error.
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint;
+}
+
+pub trait ReaderUtil {
+
+    /// Read len bytes into a new vec.
+    fn read_bytes(&self, len: uint);
+}
+
+impl<T: Reader> T : ReaderUtil {
+
+    fn read_bytes(&self, len: uint) {
+        let count = self.read(&[mut 0], len);
+    }
+
+}
+
+struct S {
+    x: int,
+    y: int
+}
+
+impl S: Reader {
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint {
+        0
+    }
+}
+
+fn main() {
+    let x = S { x: 1, y: 2 };
+    let x = x as @Reader;
+    x.read_bytes(0);
+}

src/test/run-pass/explicit-self-objects-ext-2.rs

@@ -0,0 +1,39 @@
+pub trait Reader {
+    // FIXME (#2004): Seekable really should be orthogonal.
+
+    /// Read up to len bytes (or EOF) and put them into bytes (which
+    /// must be at least len bytes long). Return number of bytes read.
+    // FIXME (#2982): This should probably return an error.
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint;
+}
+
+pub trait ReaderUtil {
+
+    /// Read len bytes into a new vec.
+    fn read_bytes(&self, len: uint);
+}
+
+impl<T: Reader> T : ReaderUtil {
+
+    fn read_bytes(&self, len: uint) {
+        let count = self.read(&[mut 0], len);
+    }
+
+}
+
+struct S {
+    x: int,
+    y: int
+}
+
+impl S: Reader {
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint {
+        0
+    }
+}
+
+fn main() {
+    let x = S { x: 1, y: 2 };
+    let x = x as @Reader;
+    x.read_bytes(0);
+}

src/test/run-pass/explicit-self-objects-ext-3.rs

@@ -0,0 +1,39 @@
+pub trait Reader {
+    // FIXME (#2004): Seekable really should be orthogonal.
+
+    /// Read up to len bytes (or EOF) and put them into bytes (which
+    /// must be at least len bytes long). Return number of bytes read.
+    // FIXME (#2982): This should probably return an error.
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint;
+}
+
+pub trait ReaderUtil {
+
+    /// Read len bytes into a new vec.
+    fn read_bytes(len: uint);
+}
+
+impl<T: Reader> T : ReaderUtil {
+
+    fn read_bytes(len: uint) {
+        let count = self.read(&[mut 0], len);
+    }
+
+}
+
+struct S {
+    x: int,
+    y: int
+}
+
+impl S: Reader {
+    fn read(&self, bytes: &[mut u8], len: uint) -> uint {
+        0
+    }
+}
+
+fn main() {
+    let x = S { x: 1, y: 2 };
+    let x = x as @Reader;
+    x.read_bytes(0);
+}

src/test/run-pass/explicit-self-objects-ext-4.rs

@@ -0,0 +1,39 @@
+pub trait Reader {
+    // FIXME (#2004): Seekable really should be orthogonal.
+
+    /// Read up to len bytes (or EOF) and put them into bytes (which
+    /// must be at least len bytes long). Return number of bytes read.
+    // FIXME (#2982): This should probably return an error.
+    fn read(bytes: &[mut u8], len: uint) -> uint;
+}
+
+pub trait ReaderUtil {
+
+    /// Read len bytes into a new vec.
+    fn read_bytes(len: uint);
+}
+
+impl<T: Reader> T : ReaderUtil {
+
+    fn read_bytes(len: uint) {
+        let count = self.read(&[mut 0], len);
+    }
+
+}
+
+struct S {
+    x: int,
+    y: int
+}
+
+impl S: Reader {
+    fn read(bytes: &[mut u8], len: uint) -> uint {
+        0
+    }
+}
+
+fn main() {
+    let x = S { x: 1, y: 2 };
+    let x = x as @Reader;
+    x.read_bytes(0);
+}