syntax: make deriving have slightly less cryptic error messages.

This unfortunately changes an error like

    error: mismatched types: expected `&&NotClone` but found `&NotClone`

into

    error: type `NotClone` does not implement any method in scope named `clone`

2 files changed, 7 insertions, 9 deletions

diff --git a/src/libsyntax/ext/deriving/cmp/ord.rs b/src/libsyntax/ext/deriving/cmp/ord.rs
index 8a2b11b798c..5a02d8eead8 100644
--- a/src/libsyntax/ext/deriving/cmp/ord.rs
+++ b/src/libsyntax/ext/deriving/cmp/ord.rs
@@ -78,14 +78,10 @@ fn cs_op(less: bool, equal: bool, cx: &ExtCtxt, span: Span, substr: &Substructur
                 _ => cx.span_bug(span, "Not exactly 2 arguments in `deriving(Ord)`")
             };
 
-            let cmp = cx.expr_binary(span, op,
-                                     cx.expr_deref(span, self_f),
-                                     cx.expr_deref(span, other_f));
+            let cmp = cx.expr_binary(span, op, self_f, other_f);
 
             let not_cmp = cx.expr_unary(span, ast::UnNot,
-                                        cx.expr_binary(span, op,
-                                                       cx.expr_deref(span, other_f),
-                                                       cx.expr_deref(span, self_f)));
+                                        cx.expr_binary(span, op, other_f, self_f));
 
             let and = cx.expr_binary(span, ast::BiAnd, not_cmp, subexpr);
             cx.expr_binary(span, ast::BiOr, cmp, and)
diff --git a/src/libsyntax/ext/deriving/generic.rs b/src/libsyntax/ext/deriving/generic.rs
index 1f778779fbd..96428dba190 100644
--- a/src/libsyntax/ext/deriving/generic.rs
+++ b/src/libsyntax/ext/deriving/generic.rs
@@ -1009,7 +1009,8 @@ impl<'a> TraitDef<'a> {
             };
             let path = cx.path_ident(sp, cx.ident_of(format!("{}_{}", prefix, i)));
             paths.push(path.clone());
-            ident_expr.push((sp, opt_id, cx.expr_path(path)));
+            let val = cx.expr(sp, ast::ExprParen(cx.expr_deref(sp, cx.expr_path(path))));
+            ident_expr.push((sp, opt_id, val));
         }
 
         let subpats = self.create_subpatterns(paths, mutbl);
@@ -1053,7 +1054,8 @@ impl<'a> TraitDef<'a> {
                     let path = cx.path_ident(sp, cx.ident_of(format!("{}_{}", prefix, i)));
 
                     paths.push(path.clone());
-                    ident_expr.push((sp, None, cx.expr_path(path)));
+                    let val = cx.expr(sp, ast::ExprParen(cx.expr_deref(sp, cx.expr_path(path))));
+                    ident_expr.push((sp, None, val));
                 }
 
                 let subpats = self.create_subpatterns(paths, mutbl);
@@ -1128,7 +1130,7 @@ pub fn cs_same_method(f: |&ExtCtxt, Span, ~[@Expr]| -> @Expr,
                 cx.expr_method_call(field.span,
                                     field.self_,
                                     substructure.method_ident,
-                                    field.other.clone())
+                                    field.other.map(|e| cx.expr_addr_of(field.span, *e)))
             });
 
             f(cx, trait_span, called)