wip

23 files changed, 93 insertions, 97 deletions

diff --git a/src/libcore/cmath.rs b/src/libcore/cmath.rs
index 9a9a7cb3112..b0aeb78afaa 100644
--- a/src/libcore/cmath.rs
+++ b/src/libcore/cmath.rs
@@ -40,15 +40,15 @@ pub extern mod c_double {
     #[link_name="fmax"] pure fn fmax(a: c_double, b: c_double) -> c_double;
     #[link_name="fmin"] pure fn fmin(a: c_double, b: c_double) -> c_double;
     pure fn nextafter(x: c_double, y: c_double) -> c_double;
-    pure fn frexp(n: c_double, &value: c_int) -> c_double;
+    pure fn frexp(n: c_double, value: &mut c_int) -> c_double;
     pure fn hypot(x: c_double, y: c_double) -> c_double;
     pure fn ldexp(x: c_double, n: c_int) -> c_double;
     #[cfg(unix)]
     #[link_name="lgamma_r"] pure fn lgamma(n: c_double,
-                                           &sign: c_int) -> c_double;
+                                           sign: &mut c_int) -> c_double;
     #[cfg(windows)]
     #[link_name="__lgamma_r"] pure fn lgamma(n: c_double,
-                                             &sign: c_int) -> c_double;
+                                             sign: &mut c_int) -> c_double;
     // renamed: log is a reserved keyword; ln seems more natural, too
     #[link_name="log"] pure fn ln(n: c_double) -> c_double;
     // renamed: "logb" /often/ is confused for log2 by beginners
@@ -58,7 +58,7 @@ pub extern mod c_double {
     pure fn log10(n: c_double) -> c_double;
     pure fn log2(n: c_double) -> c_double;
     #[link_name="ilogb"] pure fn ilog_radix(n: c_double) -> c_int;
-    pure fn modf(n: c_double, &iptr: c_double) -> c_double;
+    pure fn modf(n: c_double, iptr: &mut c_double) -> c_double;
     pure fn pow(n: c_double, e: c_double) -> c_double;
 // FIXME (#1379): enable when rounding modes become available
 //    pure fn rint(n: c_double) -> c_double;
@@ -110,7 +110,7 @@ pub extern mod c_float {
     #[link_name="fdimf"] pure fn abs_sub(a: c_float, b: c_float) -> c_float;
     #[link_name="floorf"] pure fn floor(n: c_float) -> c_float;
     #[link_name="frexpf"] pure fn frexp(n: c_float,
-                                        &value: c_int) -> c_float;
+                                        value: &mut c_int) -> c_float;
     #[link_name="fmaf"] pure fn mul_add(a: c_float,
                                         b: c_float, c: c_float) -> c_float;
     #[link_name="fmaxf"] pure fn fmax(a: c_float, b: c_float) -> c_float;
@@ -122,11 +122,11 @@ pub extern mod c_float {
 
     #[cfg(unix)]
     #[link_name="lgammaf_r"] pure fn lgamma(n: c_float,
-                                            &sign: c_int) -> c_float;
+                                            sign: &mut c_int) -> c_float;
 
     #[cfg(windows)]
     #[link_name="__lgammaf_r"] pure fn lgamma(n: c_float,
-                                              &sign: c_int) -> c_float;
+                                              sign: &mut c_int) -> c_float;
 
     #[link_name="logf"] pure fn ln(n: c_float) -> c_float;
     #[link_name="logbf"] pure fn log_radix(n: c_float) -> c_float;
@@ -135,7 +135,7 @@ pub extern mod c_float {
     #[link_name="log10f"] pure fn log10(n: c_float) -> c_float;
     #[link_name="ilogbf"] pure fn ilog_radix(n: c_float) -> c_int;
     #[link_name="modff"] pure fn modf(n: c_float,
-                                      &iptr: c_float) -> c_float;
+                                      iptr: &mut c_float) -> c_float;
     #[link_name="powf"] pure fn pow(n: c_float, e: c_float) -> c_float;
 // FIXME (#1379): enable when rounding modes become available
 //    #[link_name="rintf"] pure fn rint(n: c_float) -> c_float;
diff --git a/src/libstd/time.rs b/src/libstd/time.rs
index 627a3b8eeae..8fa1e0cf3f0 100644
--- a/src/libstd/time.rs
+++ b/src/libstd/time.rs
@@ -7,9 +7,18 @@ use result::{Result, Ok, Err};
 
 #[abi = "cdecl"]
 extern mod rustrt {
-    #[legacy_exports];
+    #[legacy_exports]
+    #[cfg(stage0)]
     fn get_time(&sec: i64, &nsec: i32);
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    fn get_time(sec: &mut i64, nsec: &mut i32);
+
+    #[cfg(stage0)]
     fn precise_time_ns(&ns: u64);
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    fn precise_time_ns(ns: &mut u64);
 
     fn rust_tzset();
     // FIXME: The i64 values can be passed by-val when #2064 is fixed.
@@ -33,22 +42,41 @@ impl Timespec : Eq {
  * Returns the current time as a `timespec` containing the seconds and
  * nanoseconds since 1970-01-01T00:00:00Z.
  */
+#[cfg(stage0)]
 pub fn get_time() -> Timespec {
     let mut sec = 0i64;
     let mut nsec = 0i32;
     rustrt::get_time(sec, nsec);
     return {sec: sec, nsec: nsec};
 }
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub fn get_time() -> Timespec {
+    let mut sec = 0i64;
+    let mut nsec = 0i32;
+    rustrt::get_time(&mut sec, &mut nsec);
+    return {sec: sec, nsec: nsec};
+}
+
 
 /**
  * Returns the current value of a high-resolution performance counter
  * in nanoseconds since an unspecified epoch.
  */
+#[cfg(stage0)]
 pub fn precise_time_ns() -> u64 {
     let mut ns = 0u64;
     rustrt::precise_time_ns(ns);
     ns
 }
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub fn precise_time_ns() -> u64 {
+    let mut ns = 0u64;
+    rustrt::precise_time_ns(&mut ns);
+    ns
+}
+
 
 /**
  * Returns the current value of a high-resolution performance counter
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index e17b52fb27d..a50189cf598 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -574,7 +574,7 @@ impl<T:cmp::Eq> inferable<T> : cmp::Eq {
 
 // "resolved" mode: the real modes.
 #[auto_serialize]
-enum rmode { by_ref, by_val, by_mutbl_ref, by_move, by_copy }
+enum rmode { by_ref, by_val, by_move, by_copy }
 
 impl rmode : to_bytes::IterBytes {
     pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index cb8416501b3..4f265e1919c 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -127,14 +127,14 @@ fn consume_non_eol_whitespace(rdr: string_reader) {
     }
 }
 
-fn push_blank_line_comment(rdr: string_reader, &comments: ~[cmnt]) {
+fn push_blank_line_comment(rdr: string_reader, comments: &mut ~[cmnt]) {
     debug!(">>> blank-line comment");
     let v: ~[~str] = ~[];
     comments.push({style: blank_line, lines: v, pos: rdr.chpos});
 }
 
 fn consume_whitespace_counting_blank_lines(rdr: string_reader,
-                                           &comments: ~[cmnt]) {
+                                           comments: &mut ~[cmnt]) {
     while is_whitespace(rdr.curr) && !is_eof(rdr) {
         if rdr.col == 0u && rdr.curr == '\n' {
             push_blank_line_comment(rdr, comments);
@@ -145,7 +145,7 @@ fn consume_whitespace_counting_blank_lines(rdr: string_reader,
 
 
 fn read_shebang_comment(rdr: string_reader, code_to_the_left: bool,
-                                                        &comments: ~[cmnt]) {
+                                            comments: &mut ~[cmnt]) {
     debug!(">>> shebang comment");
     let p = rdr.chpos;
     debug!("<<< shebang comment");
@@ -157,7 +157,7 @@ fn read_shebang_comment(rdr: string_reader, code_to_the_left: bool,
 }
 
 fn read_line_comments(rdr: string_reader, code_to_the_left: bool,
-                                                        &comments: ~[cmnt]) {
+                                          comments: &mut ~[cmnt]) {
     debug!(">>> line comments");
     let p = rdr.chpos;
     let mut lines: ~[~str] = ~[];
@@ -188,8 +188,8 @@ fn all_whitespace(s: ~str, begin: uint, end: uint) -> bool {
     return true;
 }
 
-fn trim_whitespace_prefix_and_push_line(&lines: ~[~str],
-                                        s: ~str, col: uint) unsafe {
+fn trim_whitespace_prefix_and_push_line(lines: &mut ~[~str],
+                                        s: ~str, col: uint) {
     let mut s1;
     let len = str::len(s);
     if all_whitespace(s, 0u, uint::min(len, col)) {
@@ -202,7 +202,7 @@ fn trim_whitespace_prefix_and_push_line(&lines: ~[~str],
 }
 
 fn read_block_comment(rdr: string_reader, code_to_the_left: bool,
-                                                        &comments: ~[cmnt]) {
+                                          comments: &mut ~[cmnt]) {
     debug!(">>> block comment");
     let p = rdr.chpos;
     let mut lines: ~[~str] = ~[];
@@ -228,7 +228,7 @@ fn read_block_comment(rdr: string_reader, code_to_the_left: bool,
         debug!("=== block comment level %d", level);
         if is_eof(rdr) {(rdr as reader).fatal(~"unterminated block comment");}
         if rdr.curr == '\n' {
-            trim_whitespace_prefix_and_push_line(lines, curr_line, col);
+            trim_whitespace_prefix_and_push_line(&mut lines, curr_line, col);
             curr_line = ~"";
             bump(rdr);
         } else {
@@ -248,8 +248,8 @@ fn read_block_comment(rdr: string_reader, code_to_the_left: bool,
             }
         }
     }
-    if str::len(curr_line) != 0u {
-        trim_whitespace_prefix_and_push_line(lines, curr_line, col);
+    if str::len(curr_line) != 0 {
+        trim_whitespace_prefix_and_push_line(&mut lines, curr_line, col);
     }
     let mut style = if code_to_the_left { trailing } else { isolated };
     consume_non_eol_whitespace(rdr);
@@ -267,7 +267,7 @@ fn peeking_at_comment(rdr: string_reader) -> bool {
 }
 
 fn consume_comment(rdr: string_reader, code_to_the_left: bool,
-                   &comments: ~[cmnt]) {
+                   comments: &mut ~[cmnt]) {
     debug!(">>> consume comment");
     if rdr.curr == '/' && nextch(rdr) == '/' {
         read_line_comments(rdr, code_to_the_left, comments);
@@ -299,11 +299,11 @@ fn gather_comments_and_literals(span_diagnostic: diagnostic::span_handler,
             consume_non_eol_whitespace(rdr);
             if rdr.curr == '\n' {
                 code_to_the_left = false;
-                consume_whitespace_counting_blank_lines(rdr, comments);
+                consume_whitespace_counting_blank_lines(rdr, &mut comments);
             }
             while peeking_at_comment(rdr) {
-                consume_comment(rdr, code_to_the_left, comments);
-                consume_whitespace_counting_blank_lines(rdr, comments);
+                consume_comment(rdr, code_to_the_left, &mut comments);
+                consume_whitespace_counting_blank_lines(rdr, &mut comments);
             }
             break;
         }
diff --git a/src/libsyntax/parse/eval.rs b/src/libsyntax/parse/eval.rs
index 14dc490346e..c9106028491 100644
--- a/src/libsyntax/parse/eval.rs
+++ b/src/libsyntax/parse/eval.rs
@@ -10,8 +10,8 @@ type ctx =
 fn eval_crate_directives(cx: ctx,
                          cdirs: ~[@ast::crate_directive],
                          prefix: &Path,
-                         &view_items: ~[@ast::view_item],
-                         &items: ~[@ast::item]) {
+                         view_items: &mut~[@ast::view_item],
+                         items: &mut~[@ast::item]) {
     for cdirs.each |sub_cdir| {
         eval_crate_directive(cx, *sub_cdir, prefix, view_items, items);
     }
@@ -24,7 +24,7 @@ fn eval_crate_directives_to_mod(cx: ctx, cdirs: ~[@ast::crate_directive],
         = parse_companion_mod(cx, prefix, suffix);
     let mut view_items: ~[@ast::view_item] = ~[];
     let mut items: ~[@ast::item] = ~[];
-    eval_crate_directives(cx, cdirs, prefix, view_items, items);
+    eval_crate_directives(cx, cdirs, prefix, &mut view_items, &mut items);
     return ({view_items: vec::append(view_items, cview_items),
           items: vec::append(items, citems)},
          cattrs);
@@ -82,8 +82,8 @@ fn cdir_path_opt(default: ~str, attrs: ~[ast::attribute]) -> ~str {
 }
 
 fn eval_crate_directive(cx: ctx, cdir: @ast::crate_directive, prefix: &Path,
-                        &view_items: ~[@ast::view_item],
-                        &items: ~[@ast::item]) {
+                        view_items: &mut ~[@ast::view_item],
+                        items: &mut ~[@ast::item]) {
     match cdir.node {
       ast::cdir_src_mod(vis, id, attrs) => {
         let file_path = Path(cdir_path_opt(
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 1a87d7fed69..79f7d72d2a5 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -26,7 +26,7 @@ use ast::{_mod, add, alt_check, alt_exhaustive, arg, arm, attribute,
              bind_by_ref, bind_by_implicit_ref, bind_by_value, bind_by_move,
              bitand, bitor, bitxor, blk, blk_check_mode, bound_const,
              bound_copy, bound_send, bound_trait, bound_owned, box, by_copy,
-             by_move, by_mutbl_ref, by_ref, by_val, capture_clause,
+             by_move, by_ref, by_val, capture_clause,
              capture_item, cdir_dir_mod, cdir_src_mod, cdir_view_item,
              class_immutable, class_mutable,
              crate, crate_cfg, crate_directive, decl, decl_item, decl_local,
@@ -571,7 +571,7 @@ impl parser {
     fn parse_arg_mode() -> mode {
         if self.eat(token::BINOP(token::AND)) {
             self.warn(~"Obsolete syntax has no effect");
-            expl(by_mutbl_ref)
+            expl(by_val)
         } else if self.eat(token::BINOP(token::MINUS)) {
             expl(by_move)
         } else if self.eat(token::ANDAND) {
@@ -1276,7 +1276,8 @@ impl parser {
 
         return match self.token {
           token::LPAREN | token::LBRACE | token::LBRACKET => {
-            let ket = token::flip_delimiter(self.token);
+              // tjc: ??????
+            let ket = token::flip_delimiter(copy self.token);
             tt_delim(vec::append(
                 ~[parse_tt_tok(self, true)],
                 vec::append(
@@ -1297,7 +1298,8 @@ impl parser {
         return match self.token {
           token::LBRACE | token::LPAREN | token::LBRACKET => {
             self.parse_matcher_subseq(name_idx, copy self.token,
-                                      token::flip_delimiter(self.token))
+                                      // tjc: not sure why we need a copy
+                                      token::flip_delimiter(copy self.token))
           }
           _ => self.fatal(~"expected open delimiter")
         }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index a328ff1bdf6..99b789cf63f 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -230,7 +230,7 @@ pure fn can_begin_expr(t: token) -> bool {
 }
 
 /// what's the opposite delimiter?
-fn flip_delimiter(&t: token::token) -> token::token {
+fn flip_delimiter(t: token::token) -> token::token {
     match t {
       token::LPAREN => token::RPAREN,
       token::LBRACE => token::RBRACE,
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index d08b20eed84..bff356e5cb7 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1688,7 +1688,6 @@ fn print_fn_block_args(s: ps, decl: ast::fn_decl,
 
 fn mode_to_str(m: ast::mode) -> ~str {
     match m {
-      ast::expl(ast::by_mutbl_ref) => ~"&",
       ast::expl(ast::by_move) => ~"-",
       ast::expl(ast::by_ref) => ~"&&",
       ast::expl(ast::by_val) => ~"++",
diff --git a/src/rustc/metadata/encoder.rs b/src/rustc/metadata/encoder.rs
index 87ef3b4749c..47d91c10818 100644
--- a/src/rustc/metadata/encoder.rs
+++ b/src/rustc/metadata/encoder.rs
@@ -116,7 +116,7 @@ fn encode_mutability(ebml_w: ebml::Writer, mt: class_mutability) {
 type entry<T> = {val: T, pos: uint};
 
 fn add_to_index(ecx: @encode_ctxt, ebml_w: ebml::Writer, path: &[ident],
-                &index: ~[entry<~str>], name: ident) {
+                index: &mut ~[entry<~str>], name: ident) {
     let mut full_path = ~[];
     full_path.push_all(path);
     full_path.push(name);
diff --git a/src/rustc/metadata/tydecode.rs b/src/rustc/metadata/tydecode.rs
index f3fa0e3f350..1375ff2d0be 100644
--- a/src/rustc/metadata/tydecode.rs
+++ b/src/rustc/metadata/tydecode.rs
@@ -394,7 +394,6 @@ fn parse_arg(st: @pstate, conv: conv_did) -> ty::arg {
 
 fn parse_mode(st: @pstate) -> ast::mode {
     let m = ast::expl(match next(st) {
-        '&' => ast::by_mutbl_ref,
         '-' => ast::by_move,
         '+' => ast::by_copy,
         '=' => ast::by_ref,
diff --git a/src/rustc/metadata/tyencode.rs b/src/rustc/metadata/tyencode.rs
index 88d83ca23f4..83f92b44fe8 100644
--- a/src/rustc/metadata/tyencode.rs
+++ b/src/rustc/metadata/tyencode.rs
@@ -332,7 +332,6 @@ fn enc_arg(w: io::Writer, cx: @ctxt, arg: ty::arg) {
 
 fn enc_mode(w: io::Writer, cx: @ctxt, m: mode) {
     match ty::resolved_mode(cx.tcx, m) {
-      by_mutbl_ref => w.write_char('&'),
       by_move => w.write_char('-'),
       by_copy => w.write_char('+'),
       by_ref => w.write_char('='),
diff --git a/src/rustc/middle/borrowck.rs b/src/rustc/middle/borrowck.rs
index 414890cbd7c..e2f7ba20642 100644
--- a/src/rustc/middle/borrowck.rs
+++ b/src/rustc/middle/borrowck.rs
@@ -396,10 +396,10 @@ type req_maps = {
     pure_map: HashMap<ast::node_id, bckerr>
 };
 
-fn save_and_restore<T:Copy,U>(&save_and_restore_t: T, f: fn() -> U) -> U {
-    let old_save_and_restore_t = save_and_restore_t;
+fn save_and_restore<T:Copy,U>(save_and_restore_t: &mut T, f: fn() -> U) -> U {
+    let old_save_and_restore_t = *save_and_restore_t;
     let u <- f();
-    save_and_restore_t = old_save_and_restore_t;
+    *save_and_restore_t = old_save_and_restore_t;
     move u
 }
 
diff --git a/src/rustc/middle/borrowck/check_loans.rs b/src/rustc/middle/borrowck/check_loans.rs
index 0c79c0fcd7f..51beff021fa 100644
--- a/src/rustc/middle/borrowck/check_loans.rs
+++ b/src/rustc/middle/borrowck/check_loans.rs
@@ -529,8 +529,7 @@ impl check_loan_ctxt {
                 ast::by_move => {
                     self.check_move_out(*arg);
                 }
-                ast::by_mutbl_ref | ast::by_ref |
-                ast::by_copy | ast::by_val => {
+                ast::by_ref | ast::by_copy | ast::by_val => {
                 }
             }
         }
@@ -542,9 +541,9 @@ fn check_loans_in_fn(fk: visit::fn_kind, decl: ast::fn_decl, body: ast::blk,
                      visitor: visit::vt<check_loan_ctxt>) {
 
     debug!("purity on entry=%?", copy self.declared_purity);
-    do save_and_restore(self.in_ctor) {
-        do save_and_restore(self.declared_purity) {
-            do save_and_restore(self.fn_args) {
+    do save_and_restore(&mut(self.in_ctor)) {
+        do save_and_restore(&mut(self.declared_purity)) {
+            do save_and_restore(&mut(self.fn_args)) {
                 let is_stack_closure = self.is_stack_closure(id);
                 let fty = ty::node_id_to_type(self.tcx(), id);
                 self.declared_purity = ty::determine_inherited_purity(
@@ -667,7 +666,7 @@ fn check_loans_in_expr(expr: @ast::expr,
 fn check_loans_in_block(blk: ast::blk,
                         &&self: check_loan_ctxt,
                         vt: visit::vt<check_loan_ctxt>) {
-    do save_and_restore(self.declared_purity) {
+    do save_and_restore(&mut(self.declared_purity)) {
         self.check_for_conflicting_loans(blk.node.id);
 
         match blk.node.rules {
diff --git a/src/rustc/middle/borrowck/gather_loans.rs b/src/rustc/middle/borrowck/gather_loans.rs
index 327db51518b..5dfde8c9af6 100644
--- a/src/rustc/middle/borrowck/gather_loans.rs
+++ b/src/rustc/middle/borrowck/gather_loans.rs
@@ -115,10 +115,6 @@ fn req_loans_in_expr(ex: @ast::expr,
         let scope_r = ty::re_scope(ex.id);
         for vec::each2(args, arg_tys) |arg, arg_ty| {
             match ty::resolved_mode(self.tcx(), arg_ty.mode) {
-              ast::by_mutbl_ref => {
-                let arg_cmt = self.bccx.cat_expr(*arg);
-                self.guarantee_valid(arg_cmt, m_mutbl, scope_r);
-              }
               ast::by_ref => {
                 let arg_cmt = self.bccx.cat_expr(*arg);
                 self.guarantee_valid(arg_cmt, m_imm,  scope_r);
diff --git a/src/rustc/middle/kind.rs b/src/rustc/middle/kind.rs
index 9aff382775c..1da145cabc9 100644
--- a/src/rustc/middle/kind.rs
+++ b/src/rustc/middle/kind.rs
@@ -319,13 +319,13 @@ fn check_expr(e: @expr, cx: ctx, v: visit::vt<ctx>) {
         for exprs.each |expr| { maybe_copy(cx, *expr, None); }
       }
       expr_call(f, args, _) => {
-        let mut i = 0u;
+        let mut i = 0;
         for ty::ty_fn_args(ty::expr_ty(cx.tcx, f)).each |arg_t| {
             match ty::arg_mode(cx.tcx, *arg_t) {
               by_copy => maybe_copy(cx, args[i], None),
-              by_ref | by_val | by_mutbl_ref | by_move => ()
+              by_ref | by_val | by_move => ()
             }
-            i += 1u;
+            i += 1;
         }
       }
       expr_field(lhs, _, _) => {
@@ -335,7 +335,7 @@ fn check_expr(e: @expr, cx: ctx, v: visit::vt<ctx>) {
             Some(ref mme) => {
                 match ty::arg_mode(cx.tcx, mme.self_arg) {
                     by_copy => maybe_copy(cx, lhs, None),
-                    by_ref | by_val | by_mutbl_ref | by_move => ()
+                    by_ref | by_val | by_move => ()
                 }
             }
             _ => ()
@@ -465,18 +465,10 @@ fn check_imm_free_var(cx: ctx, def: def, sp: span) {
             cx.tcx.sess.span_err(sp, msg);
         }
       }
-      def_arg(_, mode) => {
-        match ty::resolved_mode(cx.tcx, mode) {
-          by_ref | by_val | by_move | by_copy => { /* ok */ }
-          by_mutbl_ref => {
-            cx.tcx.sess.span_err(sp, msg);
-          }
-        }
-      }
       def_upvar(_, def1, _, _) => {
         check_imm_free_var(cx, *def1, sp);
       }
-      def_binding(*) | def_self(*) => { /*ok*/ }
+      def_arg(*) | def_binding(*) | def_self(*) => { /*ok*/ }
       _ => {
         cx.tcx.sess.span_bug(
             sp,
diff --git a/src/rustc/middle/liveness.rs b/src/rustc/middle/liveness.rs
index 69b325b03a4..bdf808e8568 100644
--- a/src/rustc/middle/liveness.rs
+++ b/src/rustc/middle/liveness.rs
@@ -398,8 +398,8 @@ impl IrMaps {
 
             (*v).push(id);
           }
-          Arg(_, _, by_ref) | Arg(_, _, by_mutbl_ref) |
-          Arg(_, _, by_val) | Self | Field(_) | ImplicitRet |
+          Arg(_, _, by_ref) | Arg(_, _, by_val) | Self | Field(_) |
+          ImplicitRet |
           Local(LocalInfo {kind: FromMatch(bind_by_implicit_ref), _}) => {
             debug!("--but it is not owned");
           }
@@ -831,9 +831,9 @@ impl Liveness {
         let mut changed = false;
         do self.indices2(ln, succ_ln) |idx, succ_idx| {
             changed |= copy_if_invalid(copy self.users[succ_idx].reader,
-                                       self.users[idx].reader);
+                                       &mut self.users[idx].reader);
             changed |= copy_if_invalid(copy self.users[succ_idx].writer,
-                                       self.users[idx].writer);
+                                       &mut self.users[idx].writer);
             if self.users[succ_idx].used && !self.users[idx].used {
                 self.users[idx].used = true;
                 changed = true;
@@ -844,10 +844,10 @@ impl Liveness {
                ln.to_str(), self.ln_str(succ_ln), first_merge, changed);
         return changed;
 
-        fn copy_if_invalid(src: LiveNode, &dst: LiveNode) -> bool {
+        fn copy_if_invalid(src: LiveNode, dst: &mut LiveNode) -> bool {
             if src.is_valid() {
                 if !dst.is_valid() {
-                    dst = src;
+                    *dst = src;
                     return true;
                 }
             }
@@ -919,7 +919,7 @@ impl Liveness {
         // inputs passed by & mode should be considered live on exit:
         for decl.inputs.each |arg| {
             match ty::resolved_mode(self.tcx, arg.mode) {
-              by_mutbl_ref | by_ref | by_val => {
+              by_ref | by_val => {
                 // These are "non-owned" modes, so register a read at
                 // the end.  This will prevent us from moving out of
                 // such variables but also prevent us from registering
@@ -1573,7 +1573,7 @@ fn check_expr(expr: @expr, &&self: @Liveness, vt: vt<@Liveness>) {
         let targs = ty::ty_fn_args(ty::expr_ty(self.tcx, f));
         for vec::each2(args, targs) |arg_expr, arg_ty| {
             match ty::resolved_mode(self.tcx, arg_ty.mode) {
-                by_val | by_copy | by_ref | by_mutbl_ref => {}
+                by_val | by_copy | by_ref => {}
                 by_move => {
                     self.check_move_from_expr(*arg_expr, vt);
                 }
@@ -1866,19 +1866,6 @@ impl @Liveness {
         for decl.inputs.each |arg| {
             let var = self.variable(arg.id, arg.ty.span);
             match ty::resolved_mode(self.tcx, arg.mode) {
-              by_mutbl_ref => {
-                // for mutable reference arguments, something like
-                //    x = 1;
-                // is not worth warning about, as it has visible
-                // side effects outside the fn.
-                match self.assigned_on_entry(entry_ln, var) {
-                  Some(_) => { /*ok*/ }
-                  None => {
-                    // but if it is not written, it ought to be used
-                    self.warn_about_unused(sp, entry_ln, var);
-                  }
-                }
-              }
               by_val | by_ref | by_move | by_copy => {
                 self.warn_about_unused(sp, entry_ln, var);
               }
diff --git a/src/rustc/middle/mem_categorization.rs b/src/rustc/middle/mem_categorization.rs
index fe465db1312..dc5874ea2cf 100644
--- a/src/rustc/middle/mem_categorization.rs
+++ b/src/rustc/middle/mem_categorization.rs
@@ -523,9 +523,6 @@ impl &mem_categorization_ctxt {
             // m: mutability of the argument
             // lp: loan path, must be none for aliasable things
             let {m,lp} = match ty::resolved_mode(self.tcx, mode) {
-              ast::by_mutbl_ref => {
-                {m: m_mutbl, lp: None}
-              }
               ast::by_move | ast::by_copy => {
                 {m: m_imm, lp: Some(@lp_arg(vid))}
               }
diff --git a/src/rustc/middle/trans/base.rs b/src/rustc/middle/trans/base.rs
index ce596586ddc..368a523306e 100644
--- a/src/rustc/middle/trans/base.rs
+++ b/src/rustc/middle/trans/base.rs
@@ -1503,7 +1503,7 @@ fn copy_args_to_allocas(fcx: fn_ctxt,
         // the event it's not truly needed.
         let llarg;
         match ty::resolved_mode(tcx, arg_ty.mode) {
-            ast::by_ref | ast::by_mutbl_ref => {
+            ast::by_ref => {
                 llarg = raw_llarg;
             }
             ast::by_move | ast::by_copy => {
diff --git a/src/rustc/middle/trans/callee.rs b/src/rustc/middle/trans/callee.rs
index e7b4dd171e3..c851c5bc725 100644
--- a/src/rustc/middle/trans/callee.rs
+++ b/src/rustc/middle/trans/callee.rs
@@ -592,7 +592,7 @@ fn trans_arg_expr(bcx: block,
             DoAutorefArg => { val = arg_datum.to_ref_llval(bcx); }
             DontAutorefArg => {
                 match arg_mode {
-                    ast::by_ref | ast::by_mutbl_ref => {
+                    ast::by_ref => {
                         val = arg_datum.to_ref_llval(bcx);
                     }
 
diff --git a/src/rustc/middle/trans/reflect.rs b/src/rustc/middle/trans/reflect.rs
index cdd11ee85c5..ef1cc15f5c0 100644
--- a/src/rustc/middle/trans/reflect.rs
+++ b/src/rustc/middle/trans/reflect.rs
@@ -208,7 +208,6 @@ impl reflector {
                   ast::expl(e) => match e {
                     ast::by_ref => 1u,
                     ast::by_val => 2u,
-                    ast::by_mutbl_ref => 3u,
                     ast::by_move => 4u,
                     ast::by_copy => 5u
                   }
diff --git a/src/rustc/middle/trans/shape.rs b/src/rustc/middle/trans/shape.rs
index cf58b5b51c4..e7dfac42bec 100644
--- a/src/rustc/middle/trans/shape.rs
+++ b/src/rustc/middle/trans/shape.rs
@@ -49,12 +49,12 @@ fn mk_ctxt(llmod: ModuleRef) -> ctxt {
     return {mut next_tag_id: 0u16, pad: 0u16, pad2: 0u32};
 }
 
-fn add_u16(&dest: ~[u8], val: u16) {
-    dest += ~[(val & 0xffu16) as u8, (val >> 8u16) as u8];
+fn add_u16(dest: &mut ~[u8], val: u16) {
+    *dest += ~[(val & 0xffu16) as u8, (val >> 8u16) as u8];
 }
 
-fn add_substr(&dest: ~[u8], src: ~[u8]) {
+fn add_substr(dest: &mut ~[u8], src: ~[u8]) {
     add_u16(dest, vec::len(src) as u16);
-    dest += src;
+    *dest += src;
 }
 
diff --git a/src/rustc/middle/trans/type_use.rs b/src/rustc/middle/trans/type_use.rs
index 6bd3c22f626..9140ea94e9c 100644
--- a/src/rustc/middle/trans/type_use.rs
+++ b/src/rustc/middle/trans/type_use.rs
@@ -53,7 +53,7 @@ fn type_uses_for(ccx: @crate_ctxt, fn_id: def_id, n_tps: uint)
                     by_val | by_move | by_copy => {
                         type_needs(cx, use_repr, arg.ty);
                     }
-                    by_ref | by_mutbl_ref => {}
+                    by_ref => {}
                 }
             }
         }
diff --git a/src/rustc/middle/trans/uniq.rs b/src/rustc/middle/trans/uniq.rs
index 6ab91c4a1d7..50ea363ace2 100644
--- a/src/rustc/middle/trans/uniq.rs
+++ b/src/rustc/middle/trans/uniq.rs
@@ -3,7 +3,6 @@ use lib::llvm::ValueRef;
 use common::*;
 use build::*;
 use base::*;
-use shape::llsize_of;
 use datum::immediate_rvalue;
 
 export make_free_glue, autoderef, duplicate;