diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs
index 87e1dd2d22c..27483ae94a5 100644
--- a/src/libsyntax/diagnostic.rs
+++ b/src/libsyntax/diagnostic.rs
@@ -158,7 +158,7 @@ pub fn mk_handler(emitter: Option<Emitter>) -> @handler {
         }
     };
 
-    @mut HandlerT { mut err_count: 0, emit: emit } as @handler
+    @mut HandlerT { err_count: 0, emit: emit } as @handler
 }
 
 #[deriving_eq]
diff --git a/src/libsyntax/ext/pipes/mod.rs b/src/libsyntax/ext/pipes/mod.rs
index 6d117f5ad23..8b8e48bd522 100644
--- a/src/libsyntax/ext/pipes/mod.rs
+++ b/src/libsyntax/ext/pipes/mod.rs
@@ -73,7 +73,7 @@ pub fn expand_proto(cx: ext_ctxt, _sp: span, id: ast::ident,
     let rdr = tt_rdr as reader;
     let rust_parser = Parser(sess, cfg, rdr.dup());
 
-    let proto = rust_parser.parse_proto(cx.str_of(id));
+    let mut proto = rust_parser.parse_proto(cx.str_of(id));
 
     // check for errors
     visit(proto, cx);
diff --git a/src/libsyntax/ext/pipes/pipec.rs b/src/libsyntax/ext/pipes/pipec.rs
index e8e4c939907..25760aa01b6 100644
--- a/src/libsyntax/ext/pipes/pipec.rs
+++ b/src/libsyntax/ext/pipes/pipec.rs
@@ -27,8 +27,8 @@ use core::to_str::ToStr;
 use core::vec;
 
 pub trait gen_send {
-    fn gen_send(&self, cx: ext_ctxt, try: bool) -> @ast::item;
-    fn to_ty(&self, cx: ext_ctxt) -> @ast::Ty;
+    fn gen_send(&mut self, cx: ext_ctxt, try: bool) -> @ast::item;
+    fn to_ty(&mut self, cx: ext_ctxt) -> @ast::Ty;
 }
 
 pub trait to_type_decls {
@@ -47,7 +47,7 @@ pub trait gen_init {
 }
 
 pub impl gen_send for message {
-    fn gen_send(&self, cx: ext_ctxt, try: bool) -> @ast::item {
+    fn gen_send(&mut self, cx: ext_ctxt, try: bool) -> @ast::item {
         debug!("pipec: gen_send");
         match *self {
           message(ref _id, span, ref tys, this, Some(ref next_state)) => {
@@ -193,7 +193,7 @@ pub impl gen_send for message {
           }
         }
 
-    fn to_ty(&self, cx: ext_ctxt) -> @ast::Ty {
+    fn to_ty(&mut self, cx: ext_ctxt) -> @ast::Ty {
         cx.ty_path_ast_builder(path(~[cx.ident_of(self.name())], self.span())
           .add_tys(cx.ty_vars_global(self.get_params())))
     }
@@ -259,10 +259,14 @@ pub impl to_type_decls for state {
           recv => (*self).dir.reverse()
         };
         let mut items = ~[];
-        for self.messages.each |m| {
-            if dir == send {
-                items.push(m.gen_send(cx, true));
-                items.push(m.gen_send(cx, false));
+
+        {
+            let messages = &mut *self.messages;
+            for vec::each_mut(*messages) |m| {
+                if dir == send {
+                    items.push(m.gen_send(cx, true));
+                    items.push(m.gen_send(cx, false));
+                }
             }
         }
 
@@ -395,7 +399,8 @@ pub impl gen_init for protocol {
         }
 
         cx.ty_path_ast_builder(path(~[cx.ident_of(~"super"),
-                                      cx.ident_of(~"__Buffer")], self.span)
+                                      cx.ident_of(~"__Buffer")],
+                                    copy self.span)
                                .add_tys(cx.ty_vars_global(params)))
     }
 
@@ -453,12 +458,12 @@ pub impl gen_init for protocol {
         }
 
         items.push(cx.item_mod(cx.ident_of(~"client"),
-                               self.span,
+                               copy self.span,
                                client_states));
         items.push(cx.item_mod(cx.ident_of(~"server"),
-                               self.span,
+                               copy self.span,
                                server_states));
 
-        cx.item_mod(cx.ident_of(self.name), self.span, items)
+        cx.item_mod(cx.ident_of(self.name), copy self.span, items)
     }
 }
diff --git a/src/libsyntax/ext/pipes/proto.rs b/src/libsyntax/ext/pipes/proto.rs
index da67e48dfa6..7c6dc1f937d 100644
--- a/src/libsyntax/ext/pipes/proto.rs
+++ b/src/libsyntax/ext/pipes/proto.rs
@@ -16,7 +16,6 @@ use ext::base::ext_ctxt;
 use ext::pipes::ast_builder::{append_types, ext_ctxt_ast_builder, path};
 
 use core::cmp;
-use core::dvec::DVec;
 use core::to_str::ToStr;
 
 #[deriving_eq]
@@ -45,26 +44,24 @@ pub struct next_state {
     tys: ~[@ast::Ty],
 }
 
-pub enum message {
-    // name, span, data, current state, next state
-    message(~str, span, ~[@ast::Ty], state, Option<next_state>)
-}
+// name, span, data, current state, next state
+pub struct message(~str, span, ~[@ast::Ty], state, Option<next_state>);
 
 pub impl message {
-    fn name(&self) -> ~str {
+    fn name(&mut self) -> ~str {
         match *self {
           message(ref id, _, _, _, _) => (*id)
         }
     }
 
-    fn span(&self) -> span {
+    fn span(&mut self) -> span {
         match *self {
           message(_, span, _, _, _) => span
         }
     }
 
     /// Return the type parameters actually used by this message
-    fn get_params(&self) -> ~[ast::ty_param] {
+    fn get_params(&mut self) -> ~[ast::ty_param] {
         match *self {
           message(_, _, _, this, _) => this.ty_params
         }
@@ -80,7 +77,7 @@ pub struct state_ {
     span: span,
     dir: direction,
     ty_params: ~[ast::ty_param],
-    messages: DVec<message>,
+    messages: @mut ~[message],
     proto: protocol
 }
 
@@ -121,17 +118,17 @@ pub impl state_ {
     }
 }
 
-pub type protocol = @protocol_;
+pub type protocol = @mut protocol_;
 
 pub fn protocol(name: ~str, +span: span) -> protocol {
-    @protocol_(name, span)
+    @mut protocol_(name, span)
 }
 
 pub fn protocol_(name: ~str, span: span) -> protocol_ {
     protocol_ {
         name: name,
         span: span,
-        states: DVec(),
+        states: @mut ~[],
         bounded: None
     }
 }
@@ -139,30 +136,30 @@ pub fn protocol_(name: ~str, span: span) -> protocol_ {
 pub struct protocol_ {
     name: ~str,
     span: span,
-    states: DVec<state>,
+    states: @mut ~[state],
 
-    mut bounded: Option<bool>,
+    bounded: Option<bool>,
 }
 
 pub impl protocol_ {
     /// Get a state.
-    fn get_state(&self, name: ~str) -> state {
+    fn get_state(&mut self, name: ~str) -> state {
         self.states.find(|i| i.name == name).get()
     }
 
-    fn get_state_by_id(&self, id: uint) -> state { self.states[id] }
+    fn get_state_by_id(&mut self, id: uint) -> state { self.states[id] }
 
-    fn has_state(&self, name: ~str) -> bool {
+    fn has_state(&mut self, name: ~str) -> bool {
         self.states.find(|i| i.name == name).is_some()
     }
 
-    fn filename(&self) -> ~str {
+    fn filename(&mut self) -> ~str {
         ~"proto://" + self.name
     }
 
-    fn num_states(&self) -> uint { self.states.len() }
+    fn num_states(&mut self) -> uint { self.states.len() }
 
-    fn has_ty_params(&self) -> bool {
+    fn has_ty_params(&mut self) -> bool {
         for self.states.each |s| {
             if s.ty_params.len() > 0 {
                 return true;
@@ -170,7 +167,7 @@ pub impl protocol_ {
         }
         false
     }
-    fn is_bounded(&self) -> bool {
+    fn is_bounded(&mut self) -> bool {
         let bounded = self.bounded.get();
         bounded
     }
@@ -179,7 +176,7 @@ pub impl protocol_ {
 pub impl protocol {
     fn add_state_poly(&self, name: ~str, ident: ast::ident, dir: direction,
                       +ty_params: ~[ast::ty_param]) -> state {
-        let messages = DVec();
+        let messages = @mut ~[];
 
         let state = @state_ {
             id: self.states.len(),
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 3817f89b817..a9502ff2902 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -59,7 +59,7 @@ pub fn new_tt_reader(sp_diag: span_handler,
     let r = @mut TtReader {
         sp_diag: sp_diag,
         interner: itr,
-        mut cur: @mut TtFrame {
+        cur: @mut TtFrame {
             readme: @mut src,
             idx: 0u,
             dotdotdoted: false,