libsyntax: De-`@str` literal strings in the AST

45 files changed, 432 insertions, 275 deletions

diff --git a/src/librustc/driver/driver.rs b/src/librustc/driver/driver.rs
index 2b552aff717..4a3e2ac5e2a 100644
--- a/src/librustc/driver/driver.rs
+++ b/src/librustc/driver/driver.rs
@@ -74,20 +74,20 @@ pub fn source_name(input: &Input) -> @str {
 pub fn default_configuration(sess: Session) ->
    ast::CrateConfig {
     let tos = match sess.targ_cfg.os {
-        abi::OsWin32 =>   @"win32",
-        abi::OsMacos =>   @"macos",
-        abi::OsLinux =>   @"linux",
-        abi::OsAndroid => @"android",
-        abi::OsFreebsd => @"freebsd"
+        abi::OsWin32 =>   InternedString::new("win32"),
+        abi::OsMacos =>   InternedString::new("macos"),
+        abi::OsLinux =>   InternedString::new("linux"),
+        abi::OsAndroid => InternedString::new("android"),
+        abi::OsFreebsd => InternedString::new("freebsd"),
     };
 
     // ARM is bi-endian, however using NDK seems to default
     // to little-endian unless a flag is provided.
     let (end,arch,wordsz) = match sess.targ_cfg.arch {
-        abi::X86 =>    (@"little", @"x86",    @"32"),
-        abi::X86_64 => (@"little", @"x86_64", @"64"),
-        abi::Arm =>    (@"little", @"arm",    @"32"),
-        abi::Mips =>   (@"big",    @"mips",   @"32")
+        abi::X86 =>    ("little", "x86",    "32"),
+        abi::X86_64 => ("little", "x86_64", "64"),
+        abi::Arm =>    ("little", "arm",    "32"),
+        abi::Mips =>   ("big",    "mips",   "32")
     };
 
     let fam = match sess.targ_cfg.os {
@@ -99,10 +99,11 @@ pub fn default_configuration(sess: Session) ->
     return ~[ // Target bindings.
          attr::mk_word_item(fam.clone()),
          mk(InternedString::new("target_os"), tos),
-         mk(InternedString::new("target_family"), fam.get().to_managed()),
-         mk(InternedString::new("target_arch"), arch),
-         mk(InternedString::new("target_endian"), end),
-         mk(InternedString::new("target_word_size"), wordsz),
+         mk(InternedString::new("target_family"), fam),
+         mk(InternedString::new("target_arch"), InternedString::new(arch)),
+         mk(InternedString::new("target_endian"), InternedString::new(end)),
+         mk(InternedString::new("target_word_size"),
+            InternedString::new(wordsz)),
     ];
 }
 
diff --git a/src/librustc/driver/session.rs b/src/librustc/driver/session.rs
index 57bc9c32cbd..eceed2422b6 100644
--- a/src/librustc/driver/session.rs
+++ b/src/librustc/driver/session.rs
@@ -417,7 +417,12 @@ pub fn building_library(options: &Options, crate: &ast::Crate) -> bool {
         }
     }
     match syntax::attr::first_attr_value_str_by_name(crate.attrs, "crate_type") {
-        Some(s) => "lib" == s || "rlib" == s || "dylib" == s || "staticlib" == s,
+        Some(s) => {
+            s.equiv(&("lib")) ||
+            s.equiv(&("rlib")) ||
+            s.equiv(&("dylib")) ||
+            s.equiv(&("staticlib"))
+        }
         _ => false
     }
 }
@@ -437,14 +442,20 @@ pub fn collect_outputs(session: &Session,
     let mut iter = attrs.iter().filter_map(|a| {
         if a.name().equiv(&("crate_type")) {
             match a.value_str() {
-                Some(n) if "rlib" == n => Some(OutputRlib),
-                Some(n) if "dylib" == n => Some(OutputDylib),
-                Some(n) if "lib" == n => Some(default_lib_output()),
-                Some(n) if "staticlib" == n => Some(OutputStaticlib),
-                Some(n) if "bin" == n => Some(OutputExecutable),
+                Some(ref n) if n.equiv(&("rlib")) => Some(OutputRlib),
+                Some(ref n) if n.equiv(&("dylib")) => Some(OutputDylib),
+                Some(ref n) if n.equiv(&("lib")) => {
+                    Some(default_lib_output())
+                }
+                Some(ref n) if n.equiv(&("staticlib")) => {
+                    Some(OutputStaticlib)
+                }
+                Some(ref n) if n.equiv(&("bin")) => Some(OutputExecutable),
                 Some(_) => {
-                    session.add_lint(lint::UnknownCrateType, ast::CRATE_NODE_ID,
-                                     a.span, ~"invalid `crate_type` value");
+                    session.add_lint(lint::UnknownCrateType,
+                                     ast::CRATE_NODE_ID,
+                                     a.span,
+                                     ~"invalid `crate_type` value");
                     None
                 }
                 _ => {
diff --git a/src/librustc/front/test.rs b/src/librustc/front/test.rs
index b32568abeb1..6813addc552 100644
--- a/src/librustc/front/test.rs
+++ b/src/librustc/front/test.rs
@@ -28,6 +28,7 @@ use syntax::fold::Folder;
 use syntax::fold;
 use syntax::opt_vec;
 use syntax::parse::token::InternedString;
+use syntax::parse::token;
 use syntax::print::pprust;
 use syntax::{ast, ast_util};
 use syntax::util::small_vector::SmallVector;
@@ -426,7 +427,8 @@ fn mk_test_desc_and_fn_rec(cx: &TestCtxt, test: &Test) -> @ast::Expr {
     debug!("encoding {}", ast_util::path_name_i(path));
 
     let name_lit: ast::Lit =
-        nospan(ast::LitStr(ast_util::path_name_i(path).to_managed(), ast::CookedStr));
+        nospan(ast::LitStr(token::intern_and_get_ident(
+                    ast_util::path_name_i(path)), ast::CookedStr));
 
     let name_expr = @ast::Expr {
           id: ast::DUMMY_NODE_ID,
diff --git a/src/librustc/metadata/creader.rs b/src/librustc/metadata/creader.rs
index 4670757b5c3..c43cf0a6ad7 100644
--- a/src/librustc/metadata/creader.rs
+++ b/src/librustc/metadata/creader.rs
@@ -27,8 +27,8 @@ use syntax::attr::AttrMetaMethods;
 use syntax::codemap::{Span, DUMMY_SP};
 use syntax::diagnostic::SpanHandler;
 use syntax::ext::base::{CrateLoader, MacroCrate};
+use syntax::parse::token::{IdentInterner, InternedString};
 use syntax::parse::token;
-use syntax::parse::token::IdentInterner;
 use syntax::crateid::CrateId;
 use syntax::visit;
 
@@ -126,10 +126,8 @@ fn visit_crate(e: &Env, c: &ast::Crate) {
 
     for a in c.attrs.iter().filter(|m| m.name().equiv(&("link_args"))) {
         match a.value_str() {
-          Some(ref linkarg) => {
-            cstore.add_used_link_args(*linkarg);
-          }
-          None => {/* fallthrough */ }
+          Some(ref linkarg) => cstore.add_used_link_args(linkarg.get()),
+          None => { /* fallthrough */ }
         }
     }
 }
@@ -214,9 +212,7 @@ fn visit_item(e: &Env, i: &ast::Item) {
                 .to_owned_vec();
             for m in link_args.iter() {
                 match m.value_str() {
-                    Some(linkarg) => {
-                        cstore.add_used_link_args(linkarg);
-                    }
+                    Some(linkarg) => cstore.add_used_link_args(linkarg.get()),
                     None => { /* fallthrough */ }
                 }
             }
@@ -238,12 +234,12 @@ fn visit_item(e: &Env, i: &ast::Item) {
                         }).and_then(|a| a.value_str());
                         let kind = match kind {
                             Some(k) => {
-                                if "static" == k {
+                                if k.equiv(&("static")) {
                                     cstore::NativeStatic
                                 } else if e.sess.targ_cfg.os == abi::OsMacos &&
-                                          "framework" == k {
+                                          k.equiv(&("framework")) {
                                     cstore::NativeFramework
-                                } else if "framework" == k {
+                                } else if k.equiv(&("framework")) {
                                     e.sess.span_err(m.span,
                                         "native frameworks are only available \
                                          on OSX targets");
@@ -265,13 +261,13 @@ fn visit_item(e: &Env, i: &ast::Item) {
                                 e.sess.span_err(m.span,
                                     "#[link(...)] specified without \
                                      `name = \"foo\"`");
-                                @"foo"
+                                InternedString::new("foo")
                             }
                         };
-                        if n.is_empty() {
+                        if n.get().is_empty() {
                             e.sess.span_err(m.span, "#[link(name = \"\")] given with empty name");
                         } else {
-                            cstore.add_used_library(n.to_owned(), kind);
+                            cstore.add_used_library(n.get().to_owned(), kind);
                         }
                     }
                     None => {}
diff --git a/src/librustc/metadata/decoder.rs b/src/librustc/metadata/decoder.rs
index ef6bb30cb51..65eb273b9b8 100644
--- a/src/librustc/metadata/decoder.rs
+++ b/src/librustc/metadata/decoder.rs
@@ -1050,7 +1050,7 @@ fn get_meta_items(md: ebml::Doc) -> ~[@ast::MetaItem] {
         let nd = reader::get_doc(meta_item_doc, tag_meta_item_name);
         let vd = reader::get_doc(meta_item_doc, tag_meta_item_value);
         let n = token::intern_and_get_ident(nd.as_str_slice());
-        let v = vd.as_str_slice().to_managed();
+        let v = token::intern_and_get_ident(vd.as_str_slice());
         // FIXME (#623): Should be able to decode MetaNameValue variants,
         // but currently the encoder just drops them
         items.push(attr::mk_name_value_item_str(n, v));
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 94a4639975c..d58187641db 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -1513,15 +1513,15 @@ fn encode_meta_item(ebml_w: &mut writer::Encoder, mi: @MetaItem) {
         ebml_w.end_tag();
         ebml_w.end_tag();
       }
-      MetaNameValue(ref name, value) => {
+      MetaNameValue(ref name, ref value) => {
         match value.node {
-          LitStr(value, _) => {
+          LitStr(ref value, _) => {
             ebml_w.start_tag(tag_meta_item_name_value);
             ebml_w.start_tag(tag_meta_item_name);
             ebml_w.writer.write(name.get().as_bytes());
             ebml_w.end_tag();
             ebml_w.start_tag(tag_meta_item_value);
-            ebml_w.writer.write(value.as_bytes());
+            ebml_w.writer.write(value.get().as_bytes());
             ebml_w.end_tag();
             ebml_w.end_tag();
           }
@@ -1563,7 +1563,7 @@ fn synthesize_crate_attrs(ecx: &EncodeContext,
         attr::mk_attr(
             attr::mk_name_value_item_str(
                 InternedString::new("crate_id"),
-                ecx.link_meta.crateid.to_str().to_managed()))
+                token::intern_and_get_ident(ecx.link_meta.crateid.to_str())))
     }
 
     let mut attrs = ~[];
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs
index 38376de4346..228dbb01755 100644
--- a/src/librustc/middle/check_match.rs
+++ b/src/librustc/middle/check_match.rs
@@ -214,9 +214,14 @@ fn check_exhaustive(cx: &MatchCheckCtxt, sp: Span, pats: ~[@Pat]) {
 
 type matrix = ~[~[@Pat]];
 
-enum useful { useful(ty::t, ctor), useful_, not_useful }
+#[deriving(Clone)]
+enum useful {
+    useful(ty::t, ctor),
+    useful_,
+    not_useful,
+}
 
-#[deriving(Eq)]
+#[deriving(Clone, Eq)]
 enum ctor {
     single,
     variant(DefId),
@@ -261,7 +266,7 @@ fn is_useful(cx: &MatchCheckCtxt, m: &matrix, v: &[@Pat]) -> useful {
                                           val(const_bool(false)),
                                           0u, left_ty)
                   }
-                  ref u => *u,
+                  ref u => (*u).clone(),
                 }
               }
               ty::ty_enum(eid, _) => {
@@ -269,7 +274,7 @@ fn is_useful(cx: &MatchCheckCtxt, m: &matrix, v: &[@Pat]) -> useful {
                     match is_useful_specialized(cx, m, v, variant(va.id),
                                                 va.args.len(), left_ty) {
                       not_useful => (),
-                      ref u => return *u,
+                      ref u => return (*u).clone(),
                     }
                 }
                 not_useful
@@ -289,7 +294,7 @@ fn is_useful(cx: &MatchCheckCtxt, m: &matrix, v: &[@Pat]) -> useful {
                 for n in iter::range(0u, max_len + 1) {
                   match is_useful_specialized(cx, m, v, vec(n), n, left_ty) {
                     not_useful => (),
-                    ref u => return *u,
+                    ref u => return (*u).clone(),
                   }
                 }
                 not_useful
@@ -304,15 +309,15 @@ fn is_useful(cx: &MatchCheckCtxt, m: &matrix, v: &[@Pat]) -> useful {
             match is_useful(cx,
                             &m.iter().filter_map(|r| default(cx, *r)).collect::<matrix>(),
                             v.tail()) {
-              useful_ => useful(left_ty, *ctor),
-              ref u => *u,
+              useful_ => useful(left_ty, (*ctor).clone()),
+              ref u => (*u).clone(),
             }
           }
         }
       }
       Some(ref v0_ctor) => {
         let arity = ctor_arity(cx, v0_ctor, left_ty);
-        is_useful_specialized(cx, m, v, *v0_ctor, arity, left_ty)
+        is_useful_specialized(cx, m, v, (*v0_ctor).clone(), arity, left_ty)
       }
     }
 }
@@ -329,7 +334,7 @@ fn is_useful_specialized(cx: &MatchCheckCtxt,
         cx, &ms, specialize(cx, v, &ctor, arity, lty).unwrap());
     match could_be_useful {
       useful_ => useful(lty, ctor),
-      ref u => *u,
+      ref u => (*u).clone(),
     }
 }
 
@@ -407,7 +412,7 @@ fn missing_ctor(cx: &MatchCheckCtxt,
             let r = pat_ctor_id(cx, r[0]);
             for id in r.iter() {
                 if !found.contains(id) {
-                    found.push(*id);
+                    found.push((*id).clone());
                 }
             }
         }
@@ -770,8 +775,8 @@ fn specialize(cx: &MatchCheckCtxt,
             }
             PatRange(lo, hi) => {
                 let (c_lo, c_hi) = match *ctor_id {
-                    val(ref v) => (*v, *v),
-                    range(ref lo, ref hi) => (*lo, *hi),
+                    val(ref v) => ((*v).clone(), (*v).clone()),
+                    range(ref lo, ref hi) => ((*lo).clone(), (*hi).clone()),
                     single => return Some(r.tail().to_owned()),
                     _ => fail!("type error")
                 };
diff --git a/src/librustc/middle/const_eval.rs b/src/librustc/middle/const_eval.rs
index 59057128555..68ac2f11bda 100644
--- a/src/librustc/middle/const_eval.rs
+++ b/src/librustc/middle/const_eval.rs
@@ -16,10 +16,11 @@ use middle::ty;
 use middle::typeck::astconv;
 use middle;
 
-use syntax::{ast, ast_map, ast_util};
-use syntax::visit;
-use syntax::visit::Visitor;
 use syntax::ast::*;
+use syntax::parse::token::InternedString;
+use syntax::visit::Visitor;
+use syntax::visit;
+use syntax::{ast, ast_map, ast_util};
 
 use std::cell::RefCell;
 use std::hashmap::HashMap;
@@ -319,7 +320,7 @@ pub enum const_val {
     const_float(f64),
     const_int(i64),
     const_uint(u64),
-    const_str(@str),
+    const_str(InternedString),
     const_binary(@[u8]),
     const_bool(bool)
 }
@@ -508,7 +509,7 @@ pub fn eval_const_expr_partial<T: ty::ExprTyProvider>(tcx: &T, e: &Expr)
 
 pub fn lit_to_const(lit: &Lit) -> const_val {
     match lit.node {
-        LitStr(s, _) => const_str(s),
+        LitStr(ref s, _) => const_str((*s).clone()),
         LitBinary(data) => const_binary(data),
         LitChar(n) => const_uint(n as u64),
         LitInt(n, _) => const_int(n),
@@ -530,7 +531,7 @@ pub fn compare_const_vals(a: &const_val, b: &const_val) -> Option<int> {
         (&const_int(a), &const_int(b)) => compare_vals(a, b),
         (&const_uint(a), &const_uint(b)) => compare_vals(a, b),
         (&const_float(a), &const_float(b)) => compare_vals(a, b),
-        (&const_str(a), &const_str(b)) => compare_vals(a, b),
+        (&const_str(ref a), &const_str(ref b)) => compare_vals(a, b),
         (&const_bool(a), &const_bool(b)) => compare_vals(a, b),
         _ => None
     }
diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs
index 34f8bad9666..2b100ffa4c9 100644
--- a/src/librustc/middle/lang_items.rs
+++ b/src/librustc/middle/lang_items.rs
@@ -26,8 +26,9 @@ use middle::ty::{BuiltinBound, BoundFreeze, BoundPod, BoundSend, BoundSized};
 use syntax::ast;
 use syntax::ast_util::local_def;
 use syntax::attr::AttrMetaMethods;
-use syntax::visit;
+use syntax::parse::token::InternedString;
 use syntax::visit::Visitor;
+use syntax::visit;
 
 use std::hashmap::HashMap;
 use std::iter::Enumerate;
@@ -182,11 +183,11 @@ impl LanguageItemCollector {
     }
 }
 
-pub fn extract(attrs: &[ast::Attribute]) -> Option<@str> {
+pub fn extract(attrs: &[ast::Attribute]) -> Option<InternedString> {
     for attribute in attrs.iter() {
         match attribute.name_str_pair() {
-            Some((ref key, value)) if key.equiv(&("lang")) => {
-                return Some(value);
+            Some((ref key, ref value)) if key.equiv(&("lang")) => {
+                return Some((*value).clone());
             }
             Some(..) | None => {}
         }
diff --git a/src/librustc/middle/trans/_match.rs b/src/librustc/middle/trans/_match.rs
index 7bc37d4e695..12183632948 100644
--- a/src/librustc/middle/trans/_match.rs
+++ b/src/librustc/middle/trans/_match.rs
@@ -229,6 +229,7 @@ use syntax::ast::Ident;
 use syntax::ast_util::path_to_ident;
 use syntax::ast_util;
 use syntax::codemap::{Span, DUMMY_SP};
+use syntax::parse::token::InternedString;
 
 // An option identifying a literal: either a unit-like struct or an
 // expression.
@@ -1174,7 +1175,7 @@ fn any_tuple_struct_pat(bcx: &Block, m: &[Match], col: uint) -> bool {
 struct DynamicFailureHandler<'a> {
     bcx: &'a Block<'a>,
     sp: Span,
-    msg: @str,
+    msg: InternedString,
     finished: @Cell<Option<BasicBlockRef>>,
 }
 
@@ -1187,7 +1188,7 @@ impl<'a> DynamicFailureHandler<'a> {
 
         let fcx = self.bcx.fcx;
         let fail_cx = fcx.new_block(false, "case_fallthrough", None);
-        controlflow::trans_fail(fail_cx, Some(self.sp), self.msg);
+        controlflow::trans_fail(fail_cx, Some(self.sp), self.msg.clone());
         self.finished.set(Some(fail_cx.llbb));
         fail_cx.llbb
     }
@@ -1891,7 +1892,8 @@ fn trans_match_inner<'a>(scope_cx: &'a Block<'a>,
             let fail_handler = ~DynamicFailureHandler {
                 bcx: scope_cx,
                 sp: discr_expr.span,
-                msg: @"scrutinizing value that can't exist",
+                msg: InternedString::new("scrutinizing value that can't \
+                                          exist"),
                 finished: fail_cx,
             };
             DynamicFailureHandlerClass(fail_handler)
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 38b34cd13bc..42123f536d6 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -79,13 +79,18 @@ use std::local_data;
 use syntax::ast_map::{PathName, PathPrettyName, path_elem_to_str};
 use syntax::ast_util::{local_def, is_local};
 use syntax::attr;
+use syntax::abi::{X86, X86_64, Arm, Mips, Rust, RustIntrinsic, OsWin32};
+use syntax::attr::AttrMetaMethods;
 use syntax::codemap::Span;
+use syntax::parse::token::{InternedString, special_idents};
 use syntax::parse::token;
 use syntax::{ast, ast_util, ast_map};
 use syntax::attr::AttrMetaMethods;
 use syntax::abi::{X86, X86_64, Arm, Mips, Rust, RustIntrinsic, OsWin32};
 use syntax::visit;
 use syntax::visit::Visitor;
+use syntax::visit;
+use syntax::{ast, ast_util, codemap, ast_map};
 
 pub use middle::trans::context::task_llcx;
 
@@ -604,7 +609,8 @@ pub fn compare_scalar_types<'a>(
             rslt(
                 controlflow::trans_fail(
                     cx, None,
-                    @"attempt to compare values of type type"),
+                    InternedString::new("attempt to compare values of type \
+                                         type")),
                 C_nil())
         }
         _ => {
@@ -856,9 +862,9 @@ pub fn fail_if_zero<'a>(
                     rhs_t: ty::t)
                     -> &'a Block<'a> {
     let text = if divrem == ast::BiDiv {
-        @"attempted to divide by zero"
+        "attempted to divide by zero"
     } else {
-        @"attempted remainder with a divisor of zero"
+        "attempted remainder with a divisor of zero"
     };
     let is_zero = match ty::get(rhs_t).sty {
       ty::ty_int(t) => {
@@ -875,7 +881,7 @@ pub fn fail_if_zero<'a>(
       }
     };
     with_cond(cx, is_zero, |bcx| {
-        controlflow::trans_fail(bcx, Some(span), text)
+        controlflow::trans_fail(bcx, Some(span), InternedString::new(text))
     })
 }
 
@@ -1951,7 +1957,7 @@ fn exported_name(ccx: &CrateContext, path: ast_map::Path,
                  ty: ty::t, attrs: &[ast::Attribute]) -> ~str {
     match attr::first_attr_value_str_by_name(attrs, "export_name") {
         // Use provided name
-        Some(name) => name.to_owned(),
+        Some(name) => name.get().to_owned(),
 
         // Don't mangle
         _ if attr::contains_name(attrs, "no_mangle")
@@ -2099,7 +2105,7 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
 
                     match attr::first_attr_value_str_by_name(i.attrs, "link_section") {
                         Some(sect) => unsafe {
-                            sect.with_c_str(|buf| {
+                            sect.get().with_c_str(|buf| {
                                 llvm::LLVMSetSection(v, buf);
                             })
                         },
@@ -2161,9 +2167,9 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::NodeId) -> ValueRef {
                                     ccx.crate_map
                                 }
                             } else {
-                                let ident = foreign::link_name(ccx, ni);
+                                let ident = foreign::link_name(ni);
                                 unsafe {
-                                    ident.with_c_str(|buf| {
+                                    ident.get().with_c_str(|buf| {
                                         let ty = type_of(ccx, ty);
                                         llvm::LLVMAddGlobal(ccx.llmod,
                                                             ty.to_ref(), buf)
@@ -2476,21 +2482,21 @@ pub fn create_module_map(ccx: &CrateContext) -> (ValueRef, uint) {
         let mut keys = ~[];
         let module_data = ccx.module_data.borrow();
         for (k, _) in module_data.get().iter() {
-            keys.push(k.to_managed());
+            keys.push(k.clone());
         }
         keys
     };
 
     for key in keys.iter() {
-            let llstrval = C_str_slice(ccx, *key);
-            let module_data = ccx.module_data.borrow();
-            let val = *module_data.get().find_equiv(key).unwrap();
-            let v_ptr = p2i(ccx, val);
-            let elt = C_struct([
-                llstrval,
-                v_ptr
-            ], false);
-            elts.push(elt);
+        let llstrval = C_str_slice(ccx, token::intern_and_get_ident(*key));
+        let module_data = ccx.module_data.borrow();
+        let val = *module_data.get().find_equiv(key).unwrap();
+        let v_ptr = p2i(ccx, val);
+        let elt = C_struct([
+            llstrval,
+            v_ptr
+        ], false);
+        elts.push(elt);
     }
     unsafe {
         llvm::LLVMSetInitializer(map, C_array(elttype, elts));
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index d35f9a28a83..a17ad98e426 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -30,7 +30,6 @@ use middle::ty;
 use middle::typeck;
 use util::ppaux::Repr;
 
-
 use arena::TypedArena;
 use std::c_str::ToCStr;
 use std::cast::transmute;
@@ -41,6 +40,7 @@ use std::libc::{c_uint, c_longlong, c_ulonglong, c_char};
 use syntax::ast::{Ident};
 use syntax::ast_map::{Path, PathElem, PathPrettyName};
 use syntax::codemap::Span;
+use syntax::parse::token::InternedString;
 use syntax::parse::token;
 use syntax::{ast, ast_map};
 
@@ -597,18 +597,19 @@ pub fn C_u8(i: uint) -> ValueRef {
 
 // This is a 'c-like' raw string, which differs from
 // our boxed-and-length-annotated strings.
-pub fn C_cstr(cx: &CrateContext, s: @str) -> ValueRef {
+pub fn C_cstr(cx: &CrateContext, s: InternedString) -> ValueRef {
     unsafe {
         {
             let const_cstr_cache = cx.const_cstr_cache.borrow();
-            match const_cstr_cache.get().find_equiv(&s) {
+            match const_cstr_cache.get().find(&s) {
                 Some(&llval) => return llval,
                 None => ()
             }
         }
 
         let sc = llvm::LLVMConstStringInContext(cx.llcx,
-                                                s.as_ptr() as *c_char, s.len() as c_uint,
+                                                s.get().as_ptr() as *c_char,
+                                                s.get().len() as c_uint,
                                                 False);
 
         let gsym = token::gensym("str");
@@ -627,9 +628,9 @@ pub fn C_cstr(cx: &CrateContext, s: @str) -> ValueRef {
 
 // NB: Do not use `do_spill_noroot` to make this into a constant string, or
 // you will be kicked off fast isel. See issue #4352 for an example of this.
-pub fn C_str_slice(cx: &CrateContext, s: @str) -> ValueRef {
+pub fn C_str_slice(cx: &CrateContext, s: InternedString) -> ValueRef {
     unsafe {
-        let len = s.len();
+        let len = s.get().len();
         let cs = llvm::LLVMConstPointerCast(C_cstr(cx, s), Type::i8p().to_ref());
         C_struct([cs, C_uint(cx, len)], false)
     }
@@ -970,7 +971,8 @@ pub fn dummy_substs(tps: ~[ty::t]) -> ty::substs {
 pub fn filename_and_line_num_from_span(bcx: &Block, span: Span)
                                        -> (ValueRef, ValueRef) {
     let loc = bcx.sess().parse_sess.cm.lookup_char_pos(span.lo);
-    let filename_cstr = C_cstr(bcx.ccx(), loc.file.name);
+    let filename_cstr = C_cstr(bcx.ccx(),
+                               token::intern_and_get_ident(loc.file.name));
     let filename = build::PointerCast(bcx, filename_cstr, Type::i8p());
     let line = C_int(bcx.ccx(), loc.line as int);
     (filename, line)
diff --git a/src/librustc/middle/trans/consts.rs b/src/librustc/middle/trans/consts.rs
index 79aa536a0db..ddab6407f9d 100644
--- a/src/librustc/middle/trans/consts.rs
+++ b/src/librustc/middle/trans/consts.rs
@@ -72,7 +72,7 @@ pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: ast::Lit)
         }
         ast::LitBool(b) => C_bool(b),
         ast::LitNil => C_nil(),
-        ast::LitStr(s, _) => C_str_slice(cx, s),
+        ast::LitStr(ref s, _) => C_str_slice(cx, (*s).clone()),
         ast::LitBinary(data) => C_binary_slice(cx, data),
     }
 }
@@ -312,7 +312,9 @@ fn const_expr_unadjusted(cx: @CrateContext, e: &ast::Expr,
     unsafe {
         let _icx = push_ctxt("const_expr");
         return match e.node {
-          ast::ExprLit(lit) => (consts::const_lit(cx, e, *lit), true),
+          ast::ExprLit(lit) => {
+              (consts::const_lit(cx, e, (*lit).clone()), true)
+          }
           ast::ExprBinary(_, b, e1, e2) => {
             let (te1, _) = const_expr(cx, e1, is_local);
             let (te2, _) = const_expr(cx, e2, is_local);
diff --git a/src/librustc/middle/trans/context.rs b/src/librustc/middle/trans/context.rs
index 8503ce9066b..7968f034209 100644
--- a/src/librustc/middle/trans/context.rs
+++ b/src/librustc/middle/trans/context.rs
@@ -19,12 +19,12 @@ use middle::resolve;
 use middle::trans::adt;
 use middle::trans::base;
 use middle::trans::builder::Builder;
-use middle::trans::debuginfo;
 use middle::trans::common::{C_i32, C_null};
-use middle::ty;
-
+use middle::trans::common::{mono_id,ExternMap,tydesc_info,BuilderRef_res,Stats};
+use middle::trans::base::{decl_crate_map};
+use middle::trans::debuginfo;
 use middle::trans::type_::Type;
-
+use middle::ty;
 use util::sha2::Sha256;
 
 use std::cell::{Cell, RefCell};
@@ -33,10 +33,7 @@ use std::hashmap::{HashMap, HashSet};
 use std::local_data;
 use std::libc::c_uint;
 use syntax::ast;
-
-use middle::trans::common::{mono_id,ExternMap,tydesc_info,BuilderRef_res,Stats};
-
-use middle::trans::base::{decl_crate_map};
+use syntax::parse::token::InternedString;
 
 pub struct CrateContext {
      sess: session::Session,
@@ -71,7 +68,7 @@ pub struct CrateContext {
      // Cache generated vtables
      vtables: RefCell<HashMap<(ty::t, mono_id), ValueRef>>,
      // Cache of constant strings,
-     const_cstr_cache: RefCell<HashMap<@str, ValueRef>>,
+     const_cstr_cache: RefCell<HashMap<InternedString, ValueRef>>,
 
      // Reverse-direction for const ptrs cast from globals.
      // Key is an int, cast from a ValueRef holding a *T,
diff --git a/src/librustc/middle/trans/controlflow.rs b/src/librustc/middle/trans/controlflow.rs
index 8c8c6829e49..6de34d98941 100644
--- a/src/librustc/middle/trans/controlflow.rs
+++ b/src/librustc/middle/trans/controlflow.rs
@@ -28,6 +28,8 @@ use syntax::ast;
 use syntax::ast::Name;
 use syntax::ast_util;
 use syntax::codemap::Span;
+use syntax::parse::token::InternedString;
+use syntax::parse::token;
 use syntax::visit::Visitor;
 
 pub fn trans_stmt<'a>(cx: &'a Block<'a>,
@@ -342,14 +344,14 @@ pub fn trans_fail_expr<'a>(
                     ppaux::ty_to_str(tcx, arg_datum.ty));
             }
         }
-        _ => trans_fail(bcx, sp_opt, @"explicit failure")
+        _ => trans_fail(bcx, sp_opt, InternedString::new("explicit failure"))
     }
 }
 
 pub fn trans_fail<'a>(
                   bcx: &'a Block<'a>,
                   sp_opt: Option<Span>,
-                  fail_str: @str)
+                  fail_str: InternedString)
                   -> &'a Block<'a> {
     let _icx = push_ctxt("trans_fail");
     let V_fail_str = C_cstr(bcx.ccx(), fail_str);
@@ -367,11 +369,11 @@ fn trans_fail_value<'a>(
       Some(sp) => {
         let sess = bcx.sess();
         let loc = sess.parse_sess.cm.lookup_char_pos(sp.lo);
-        (C_cstr(bcx.ccx(), loc.file.name),
+        (C_cstr(bcx.ccx(), token::intern_and_get_ident(loc.file.name)),
          loc.line as int)
       }
       None => {
-        (C_cstr(bcx.ccx(), @"<runtime>"), 0)
+        (C_cstr(bcx.ccx(), InternedString::new("<runtime>")), 0)
       }
     };
     let V_str = PointerCast(bcx, V_fail_str, Type::i8p());
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index d0a01f56b53..b5c7284dca5 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/src/librustc/middle/trans/expr.rs
@@ -543,9 +543,7 @@ fn trans_datum_unadjusted<'a>(bcx: &'a Block<'a>,
             let heap = heap_exchange;
             return trans_boxed_expr(bcx, box_ty, contents, contents_ty, heap)
         }
-        ast::ExprLit(lit) => {
-            trans_immediate_lit(bcx, expr, *lit)
-        }
+        ast::ExprLit(lit) => trans_immediate_lit(bcx, expr, (*lit).clone()),
         ast::ExprBinary(_, op, lhs, rhs) => {
             // if overloaded, would be RvalueDpsExpr
             {
@@ -836,8 +834,8 @@ fn trans_rvalue_dps_unadjusted<'a>(bcx: &'a Block<'a>,
         }
         ast::ExprLit(lit) => {
             match lit.node {
-                ast::LitStr(s, _) => {
-                    tvec::trans_lit_str(bcx, expr, s, dest)
+                ast::LitStr(ref s, _) => {
+                    tvec::trans_lit_str(bcx, expr, (*s).clone(), dest)
                 }
                 _ => {
                     bcx.tcx()
diff --git a/src/librustc/middle/trans/foreign.rs b/src/librustc/middle/trans/foreign.rs
index d9a34e1da7d..bc9dd767ec6 100644
--- a/src/librustc/middle/trans/foreign.rs
+++ b/src/librustc/middle/trans/foreign.rs
@@ -31,7 +31,8 @@ use std::vec;
 use syntax::abi::{Cdecl, Aapcs, C, AbiSet, Win64};
 use syntax::abi::{RustIntrinsic, Rust, Stdcall, Fastcall, System};
 use syntax::codemap::Span;
-use syntax::parse::token::special_idents;
+use syntax::parse::token::{InternedString, special_idents};
+use syntax::parse::token;
 use syntax::{ast};
 use syntax::{attr, ast_map};
 use util::ppaux::{Repr, UserString};
@@ -135,7 +136,7 @@ pub fn register_foreign_item_fn(ccx: @CrateContext,
     };
 
     // Register the function as a C extern fn
-    let lname = link_name(ccx, foreign_item);
+    let lname = link_name(foreign_item);
     let tys = foreign_types_for_id(ccx, foreign_item.id);
 
     // Make sure the calling convention is right for variadic functions
@@ -150,8 +151,12 @@ pub fn register_foreign_item_fn(ccx: @CrateContext,
     let llfn;
     {
         let mut externs = ccx.externs.borrow_mut();
-        llfn = base::get_extern_fn(externs.get(), ccx.llmod, lname,
-                                   cc, llfn_ty, tys.fn_sig.output);
+        llfn = base::get_extern_fn(externs.get(),
+                                   ccx.llmod,
+                                   lname.get(),
+                                   cc,
+                                   llfn_ty,
+                                   tys.fn_sig.output);
     };
     add_argument_attributes(&tys, llfn);
 
@@ -372,9 +377,9 @@ pub fn trans_foreign_mod(ccx: @CrateContext,
             _ => ()
         }
 
-        let lname = link_name(ccx, foreign_item);
+        let lname = link_name(foreign_item);
         let mut item_symbols = ccx.item_symbols.borrow_mut();
-        item_symbols.get().insert(foreign_item.id, lname.to_owned());
+        item_symbols.get().insert(foreign_item.id, lname.get().to_owned());
     }
 }
 
@@ -726,10 +731,10 @@ pub fn trans_rust_fn_with_foreign_abi(ccx: @CrateContext,
 // This code is kind of a confused mess and needs to be reworked given
 // the massive simplifications that have occurred.
 
-pub fn link_name(ccx: &CrateContext, i: @ast::ForeignItem) -> @str {
+pub fn link_name(i: @ast::ForeignItem) -> InternedString {
      match attr::first_attr_value_str_by_name(i.attrs, "link_name") {
-        None => ccx.sess.str_of(i.ident),
-        Some(ln) => ln,
+        None => token::get_ident(i.ident.name),
+        Some(ln) => ln.clone(),
     }
 }
 
diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index 705501c8223..e002ecf0471 100644
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -15,32 +15,33 @@
 
 use back::abi;
 use back::link::*;
-use lib;
 use lib::llvm::{llvm, ValueRef, True};
+use lib;
 use middle::lang_items::{FreeFnLangItem, ExchangeFreeFnLangItem};
 use middle::trans::adt;
 use middle::trans::base::*;
+use middle::trans::build::*;
 use middle::trans::callee;
 use middle::trans::cleanup;
 use middle::trans::cleanup::CleanupMethods;
 use middle::trans::common::*;
-use middle::trans::build::*;
+use middle::trans::datum::immediate_rvalue;
 use middle::trans::expr;
 use middle::trans::machine::*;
 use middle::trans::reflect;
 use middle::trans::tvec;
+use middle::trans::type_::Type;
 use middle::trans::type_of::type_of;
 use middle::ty;
-use util::ppaux;
 use util::ppaux::ty_to_short_str;
-
-use middle::trans::type_::Type;
+use util::ppaux;
 
 use arena::TypedArena;
 use std::c_str::ToCStr;
 use std::cell::Cell;
 use std::libc::c_uint;
 use syntax::ast;
+use syntax::parse::token;
 
 pub fn trans_free<'a>(cx: &'a Block<'a>, v: ValueRef) -> &'a Block<'a> {
     let _icx = push_ctxt("trans_free");
@@ -480,7 +481,8 @@ pub fn declare_tydesc(ccx: &CrateContext, t: ty::t) -> @tydesc_info {
         }
     });
 
-    let ty_name = C_str_slice(ccx, ppaux::ty_to_str(ccx.tcx, t).to_managed());
+    let ty_name = token::intern_and_get_ident(ppaux::ty_to_str(ccx.tcx, t));
+    let ty_name = C_estr_slice(ccx, ty_name);
 
     let inf = @tydesc_info {
         ty: t,
diff --git a/src/librustc/middle/trans/reflect.rs b/src/librustc/middle/trans/reflect.rs
index 0e245de6019..7e01f162bb1 100644
--- a/src/librustc/middle/trans/reflect.rs
+++ b/src/librustc/middle/trans/reflect.rs
@@ -20,6 +20,7 @@ use middle::trans::datum::*;
 use middle::trans::glue;
 use middle::trans::machine;
 use middle::trans::meth;
+use middle::trans::type_::Type;
 use middle::trans::type_of::*;
 use middle::ty;
 use util::ppaux::ty_to_str;
@@ -31,9 +32,8 @@ use std::vec;
 use syntax::ast::DefId;
 use syntax::ast;
 use syntax::ast_map::PathName;
-use syntax::parse::token::special_idents;
-
-use middle::trans::type_::Type;
+use syntax::parse::token::{InternedString, special_idents};
+use syntax::parse::token;
 
 pub struct Reflector<'a> {
     visitor_val: ValueRef,
@@ -56,14 +56,14 @@ impl<'a> Reflector<'a> {
         C_bool(b)
     }
 
-    pub fn c_slice(&mut self, s: @str) -> ValueRef {
+    pub fn c_slice(&mut self, s: InternedString) -> ValueRef {
         // We're careful to not use first class aggregates here because that
         // will kick us off fast isel. (Issue #4352.)
         let bcx = self.bcx;
         let str_vstore = ty::vstore_slice(ty::ReStatic);
         let str_ty = ty::mk_str(bcx.tcx(), str_vstore);
         let scratch = rvalue_scratch_datum(bcx, str_ty, "");
-        let len = C_uint(bcx.ccx(), s.len());
+        let len = C_uint(bcx.ccx(), s.get().len());
         let c_str = PointerCast(bcx, C_cstr(bcx.ccx(), s), Type::i8p());
         Store(bcx, c_str, GEPi(bcx, scratch.val, [ 0, 0 ]));
         Store(bcx, len, GEPi(bcx, scratch.val, [ 0, 1 ]));
@@ -260,15 +260,19 @@ impl<'a> Reflector<'a> {
                         fields[0].ident.name != special_idents::unnamed_field.name;
               }
 
-              let extra = ~[self.c_slice(ty_to_str(tcx, t).to_managed()),
-                            self.c_bool(named_fields),
-                            self.c_uint(fields.len())] + self.c_size_and_align(t);
+              let extra = ~[
+                  self.c_slice(token::intern_and_get_ident(ty_to_str(tcx,
+                                                                     t))),
+                  self.c_bool(named_fields),
+                  self.c_uint(fields.len())
+              ] + self.c_size_and_align(t);
               self.bracketed("class", extra, |this| {
                   for (i, field) in fields.iter().enumerate() {
-                      let extra = ~[this.c_uint(i),
-                                    this.c_slice(bcx.ccx().sess.str_of(field.ident)),
-                                    this.c_bool(named_fields)]
-                          + this.c_mt(&field.mt);
+                      let extra = ~[
+                        this.c_uint(i),
+                        this.c_slice(token::get_ident(field.ident.name)),
+                        this.c_bool(named_fields)
+                      ] + this.c_mt(&field.mt);
                       this.visit("class_field", extra);
                   }
               })
@@ -330,7 +334,7 @@ impl<'a> Reflector<'a> {
                 + self.c_size_and_align(t);
             self.bracketed("enum", enum_args, |this| {
                 for (i, v) in variants.iter().enumerate() {
-                    let name = ccx.sess.str_of(v.name);
+                    let name = token::get_ident(v.name.name);
                     let variant_args = ~[this.c_uint(i),
                                          C_u64(v.disr_val),
                                          this.c_uint(v.args.len()),
@@ -352,7 +356,9 @@ impl<'a> Reflector<'a> {
           }
 
           ty::ty_trait(_, _, _, _, _) => {
-              let extra = [self.c_slice(ty_to_str(tcx, t).to_managed())];
+              let extra = [
+                  self.c_slice(token::intern_and_get_ident(ty_to_str(tcx, t)))
+              ];
               self.visit("trait", extra);
           }
 
diff --git a/src/librustc/middle/trans/tvec.rs b/src/librustc/middle/trans/tvec.rs
index 5754a9ba88b..b0b7abbf664 100644
--- a/src/librustc/middle/trans/tvec.rs
+++ b/src/librustc/middle/trans/tvec.rs
@@ -31,6 +31,7 @@ use middle::ty;
 use util::ppaux::ty_to_str;
 
 use syntax::ast;
+use syntax::parse::token::InternedString;
 
 // Boxed vector types are in some sense currently a "shorthand" for a box
 // containing an unboxed vector. This expands a boxed vector type into such an
@@ -232,7 +233,10 @@ pub fn trans_slice_vstore<'a>(
         ast::ExprLit(lit) => {
             match lit.node {
                 ast::LitStr(s, _) => {
-                    return trans_lit_str(bcx, content_expr, s, dest);
+                    return trans_lit_str(bcx,
+                                         content_expr,
+                                         (*s).clone(),
+                                         dest)
                 }
                 _ => {}
             }
@@ -284,7 +288,7 @@ pub fn trans_slice_vstore<'a>(
 pub fn trans_lit_str<'a>(
                      bcx: &'a Block<'a>,
                      lit_expr: &ast::Expr,
-                     str_lit: @str,
+                     str_lit: InternedString,
                      dest: Dest)
                      -> &'a Block<'a> {
     /*!
@@ -301,7 +305,7 @@ pub fn trans_lit_str<'a>(
         Ignore => bcx,
         SaveIn(lldest) => {
             unsafe {
-                let bytes = str_lit.len();
+                let bytes = str_lit.get().len();
                 let llbytes = C_uint(bcx.ccx(), bytes);
                 let llcstr = C_cstr(bcx.ccx(), str_lit);
                 let llcstr = llvm::LLVMConstPointerCast(llcstr, Type::i8p().to_ref());
@@ -337,11 +341,15 @@ pub fn trans_uniq_or_managed_vstore<'a>(bcx: &'a Block<'a>,
                 ast::ExprLit(lit) => {
                     match lit.node {
                         ast::LitStr(s, _) => {
-                            let llptrval = C_cstr(bcx.ccx(), s);
-                            let llptrval = PointerCast(bcx, llptrval, Type::i8p());
+                            let llptrval = C_cstr(bcx.ccx(), (*s).clone());
+                            let llptrval = PointerCast(bcx,
+                                                       llptrval,
+                                                       Type::i8p());
                             let llsizeval = C_uint(bcx.ccx(), s.len());
                             let typ = ty::mk_str(bcx.tcx(), ty::vstore_uniq);
-                            let lldestval = rvalue_scratch_datum(bcx, typ, "");
+                            let lldestval = rvalue_scratch_datum(bcx,
+                                                                 typ,
+                                                                 "");
                             let alloc_fn = langcall(bcx,
                                                     Some(lit.span),
                                                     "",
@@ -405,15 +413,13 @@ pub fn write_content<'a>(
     match content_expr.node {
         ast::ExprLit(lit) => {
             match lit.node {
-                ast::LitStr(s, _) => {
+                ast::LitStr(ref s, _) => {
                     match dest {
-                        Ignore => {
-                            return bcx;
-                        }
+                        Ignore => return bcx,
                         SaveIn(lldest) => {
-                            let bytes = s.len();
+                            let bytes = s.get().len();
                             let llbytes = C_uint(bcx.ccx(), bytes);
-                            let llcstr = C_cstr(bcx.ccx(), s);
+                            let llcstr = C_cstr(bcx.ccx(), (*s).clone());
                             base::call_memcpy(bcx,
                                               lldest,
                                               llcstr,
@@ -516,7 +522,7 @@ pub fn elements_required(bcx: &Block, content_expr: &ast::Expr) -> uint {
     match content_expr.node {
         ast::ExprLit(lit) => {
             match lit.node {
-                ast::LitStr(s, _) => s.len(),
+                ast::LitStr(ref s, _) => s.get().len(),
                 _ => {
                     bcx.tcx().sess.span_bug(content_expr.span,
                                             "Unexpected evec content")
diff --git a/src/librustdoc/clean.rs b/src/librustdoc/clean.rs
index 564fb465c02..4a4e7741982 100644
--- a/src/librustdoc/clean.rs
+++ b/src/librustdoc/clean.rs
@@ -252,14 +252,16 @@ impl<'a> attr::AttrMetaMethods for &'a Attribute {
         }
     }
 
-    fn value_str(&self) -> Option<@str> {
+    fn value_str(&self) -> Option<InternedString> {
         match **self {
-            NameValue(_, ref v) => Some(v.to_managed()),
+            NameValue(_, ref v) => Some(token::intern_and_get_ident(*v)),
             _ => None,
         }
     }
     fn meta_item_list<'a>(&'a self) -> Option<&'a [@ast::MetaItem]> { None }
-    fn name_str_pair(&self) -> Option<(InternedString, @str)> { None }
+    fn name_str_pair(&self) -> Option<(InternedString, InternedString)> {
+        None
+    }
 }
 
 #[deriving(Clone, Encodable, Decodable)]
@@ -1144,7 +1146,7 @@ impl ToSource for syntax::codemap::Span {
 
 fn lit_to_str(lit: &ast::Lit) -> ~str {
     match lit.node {
-        ast::LitStr(st, _) => st.to_owned(),
+        ast::LitStr(ref st, _) => st.get().to_owned(),
         ast::LitBinary(data) => format!("{:?}", data.as_slice()),
         ast::LitChar(c) => ~"'" + std::char::from_u32(c).unwrap().to_str() + "'",
         ast::LitInt(i, _t) => i.to_str(),
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 2885d05a5bd..86b6a5734a5 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -45,6 +45,7 @@ use extra::arc::Arc;
 use extra::json::ToJson;
 use syntax::ast;
 use syntax::attr;
+use syntax::parse::token::InternedString;
 
 use clean;
 use doctree;
@@ -803,12 +804,13 @@ impl<'a> Item<'a> {
 impl<'a> fmt::Default for Item<'a> {
     fn fmt(it: &Item<'a>, fmt: &mut fmt::Formatter) {
         match attr::find_stability(it.item.attrs.iter()) {
-            Some(stability) => {
+            Some(ref stability) => {
                 write!(fmt.buf,
                        "<a class='stability {lvl}' title='{reason}'>{lvl}</a>",
                        lvl = stability.level.to_str(),
                        reason = match stability.text {
-                           Some(s) => s, None => @"",
+                           Some(ref s) => (*s).clone(),
+                           None => InternedString::new(""),
                        });
             }
             None => {}
diff --git a/src/librustpkg/util.rs b/src/librustpkg/util.rs
index 3f1762009bc..d806194ffbc 100644
--- a/src/librustpkg/util.rs
+++ b/src/librustpkg/util.rs
@@ -31,6 +31,7 @@ use syntax::{ast, attr, codemap, diagnostic, fold, visit};
 use syntax::attr::AttrMetaMethods;
 use syntax::fold::Folder;
 use syntax::parse::token::InternedString;
+use syntax::parse::token;
 use syntax::visit::Visitor;
 use syntax::util::small_vector::SmallVector;
 use syntax::crateid::CrateId;
@@ -317,8 +318,9 @@ pub fn compile_input(context: &BuildContext,
     if !attr::contains_name(crate.attrs, "crate_id") {
         // FIXME (#9639): This needs to handle non-utf8 paths
         let crateid_attr =
-            attr::mk_name_value_item_str(InternedString::new("crate_id"),
-                                         crate_id.to_str().to_managed());
+            attr::mk_name_value_item_str(
+                InternedString::new("crate_id"),
+                token::intern_and_get_ident(crate_id.to_str()));
 
         debug!("crateid attr: {:?}", crateid_attr);
         crate.attrs.push(attr::mk_attr(crateid_attr));
@@ -646,7 +648,7 @@ pub fn find_and_install_dependencies(installer: &mut CrateInstaller,
     visit::walk_crate(installer, c, ())
 }
 
-pub fn mk_string_lit(s: @str) -> ast::Lit {
+pub fn mk_string_lit(s: InternedString) -> ast::Lit {
     Spanned {
         node: ast::LitStr(s, ast::CookedStr),
         span: DUMMY_SP
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index f7e474f666c..7416e213792 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -722,7 +722,7 @@ pub type Lit = Spanned<Lit_>;
 
 #[deriving(Clone, Eq, Encodable, Decodable, IterBytes)]
 pub enum Lit_ {
-    LitStr(@str, StrStyle),
+    LitStr(InternedString, StrStyle),
     LitBinary(@[u8]),
     LitChar(u32),
     LitInt(i64, IntTy),
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index 6c6f47bae8a..78e9d3bd46f 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -17,6 +17,7 @@ use codemap::BytePos;
 use diagnostic::SpanHandler;
 use parse::comments::{doc_comment_style, strip_doc_comment_decoration};
 use parse::token::InternedString;
+use parse::token;
 use crateid::CrateId;
 
 use std::hashmap::HashSet;
@@ -34,7 +35,7 @@ pub trait AttrMetaMethods {
      * Gets the string value if self is a MetaNameValue variant
      * containing a string, otherwise None.
      */
-    fn value_str(&self) -> Option<@str>;
+    fn value_str(&self) -> Option<InternedString>;
     /// Gets a list of inner meta items from a list MetaItem type.
     fn meta_item_list<'a>(&'a self) -> Option<&'a [@MetaItem]>;
 
@@ -42,16 +43,18 @@ pub trait AttrMetaMethods {
      * If the meta item is a name-value type with a string value then returns
      * a tuple containing the name and string value, otherwise `None`
      */
-    fn name_str_pair(&self) -> Option<(InternedString, @str)>;
+    fn name_str_pair(&self) -> Option<(InternedString,InternedString)>;
 }
 
 impl AttrMetaMethods for Attribute {
     fn name(&self) -> InternedString { self.meta().name() }
-    fn value_str(&self) -> Option<@str> { self.meta().value_str() }
+    fn value_str(&self) -> Option<InternedString> {
+        self.meta().value_str()
+    }
     fn meta_item_list<'a>(&'a self) -> Option<&'a [@MetaItem]> {
         self.node.value.meta_item_list()
     }
-    fn name_str_pair(&self) -> Option<(InternedString, @str)> {
+    fn name_str_pair(&self) -> Option<(InternedString,InternedString)> {
         self.meta().name_str_pair()
     }
 }
@@ -65,11 +68,11 @@ impl AttrMetaMethods for MetaItem {
         }
     }
 
-    fn value_str(&self) -> Option<@str> {
+    fn value_str(&self) -> Option<InternedString> {
         match self.node {
             MetaNameValue(_, ref v) => {
                 match v.node {
-                    ast::LitStr(s, _) => Some(s),
+                    ast::LitStr(ref s, _) => Some((*s).clone()),
                     _ => None,
                 }
             },
@@ -84,7 +87,7 @@ impl AttrMetaMethods for MetaItem {
         }
     }
 
-    fn name_str_pair(&self) -> Option<(InternedString, @str)> {
+    fn name_str_pair(&self) -> Option<(InternedString,InternedString)> {
         self.value_str().map(|s| (self.name(), s))
     }
 }
@@ -92,11 +95,11 @@ impl AttrMetaMethods for MetaItem {
 // Annoying, but required to get test_cfg to work
 impl AttrMetaMethods for @MetaItem {
     fn name(&self) -> InternedString { (**self).name() }
-    fn value_str(&self) -> Option<@str> { (**self).value_str() }
+    fn value_str(&self) -> Option<InternedString> { (**self).value_str() }
     fn meta_item_list<'a>(&'a self) -> Option<&'a [@MetaItem]> {
         (**self).meta_item_list()
     }
-    fn name_str_pair(&self) -> Option<(InternedString, @str)> {
+    fn name_str_pair(&self) -> Option<(InternedString,InternedString)> {
         (**self).name_str_pair()
     }
 }
@@ -119,8 +122,10 @@ impl AttributeMethods for Attribute {
     fn desugar_doc(&self) -> Attribute {
         if self.node.is_sugared_doc {
             let comment = self.value_str().unwrap();
-            let meta = mk_name_value_item_str(InternedString::new("doc"),
-                                              strip_doc_comment_decoration(comment).to_managed());
+            let meta = mk_name_value_item_str(
+                InternedString::new("doc"),
+                token::intern_and_get_ident(strip_doc_comment_decoration(
+                        comment.get())));
             mk_attr(meta)
         } else {
             *self
@@ -130,7 +135,7 @@ impl AttributeMethods for Attribute {
 
 /* Constructors */
 
-pub fn mk_name_value_item_str(name: InternedString, value: @str)
+pub fn mk_name_value_item_str(name: InternedString, value: InternedString)
                               -> @MetaItem {
     let value_lit = dummy_spanned(ast::LitStr(value, ast::CookedStr));
     mk_name_value_item(name, value_lit)
@@ -157,8 +162,9 @@ pub fn mk_attr(item: @MetaItem) -> Attribute {
     })
 }
 
-pub fn mk_sugared_doc_attr(text: @str, lo: BytePos, hi: BytePos) -> Attribute {
-    let style = doc_comment_style(text);
+pub fn mk_sugared_doc_attr(text: InternedString, lo: BytePos, hi: BytePos)
+                           -> Attribute {
+    let style = doc_comment_style(text.get());
     let lit = spanned(lo, hi, ast::LitStr(text, ast::CookedStr));
     let attr = Attribute_ {
         style: style,
@@ -191,14 +197,14 @@ pub fn contains_name<AM: AttrMetaMethods>(metas: &[AM], name: &str) -> bool {
 }
 
 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str)
-                                 -> Option<@str> {
+                                 -> Option<InternedString> {
     attrs.iter()
         .find(|at| at.name().equiv(&name))
         .and_then(|at| at.value_str())
 }
 
 pub fn last_meta_item_value_str_by_name(items: &[@MetaItem], name: &str)
-                                     -> Option<@str> {
+                                     -> Option<InternedString> {
     items.rev_iter()
          .find(|mi| mi.name().equiv(&name))
          .and_then(|i| i.value_str())
@@ -247,7 +253,7 @@ pub fn find_linkage_metas(attrs: &[Attribute]) -> ~[@MetaItem] {
 pub fn find_crateid(attrs: &[Attribute]) -> Option<CrateId> {
     match first_attr_value_str_by_name(attrs, "crate_id") {
         None => None,
-        Some(id) => from_str::<CrateId>(id),
+        Some(id) => from_str::<CrateId>(id.get()),
     }
 }
 
@@ -331,7 +337,7 @@ pub fn test_cfg<AM: AttrMetaMethods, It: Iterator<AM>>
 /// Represents the #[deprecated="foo"] (etc) attributes.
 pub struct Stability {
     level: StabilityLevel,
-    text: Option<@str>
+    text: Option<InternedString>
 }
 
 /// The available stability levels.
@@ -346,7 +352,8 @@ pub enum StabilityLevel {
 }
 
 /// Find the first stability attribute. `None` if none exists.
-pub fn find_stability<AM: AttrMetaMethods, It: Iterator<AM>>(mut metas: It) -> Option<Stability> {
+pub fn find_stability<AM: AttrMetaMethods, It: Iterator<AM>>(mut metas: It)
+                      -> Option<Stability> {
     for m in metas {
         let level = match m.name().get() {
             "deprecated" => Deprecated,
diff --git a/src/libsyntax/ext/asm.rs b/src/libsyntax/ext/asm.rs
index 021f0d29d9e..babf0f13874 100644
--- a/src/libsyntax/ext/asm.rs
+++ b/src/libsyntax/ext/asm.rs
@@ -17,6 +17,7 @@ use codemap::Span;
 use ext::base;
 use ext::base::*;
 use parse;
+use parse::token::InternedString;
 use parse::token;
 
 enum State {
@@ -43,7 +44,7 @@ pub fn expand_asm(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                                            cx.cfg(),
                                            tts.to_owned());
 
-    let mut asm = @"";
+    let mut asm = InternedString::new("");
     let mut asm_str_style = None;
     let mut outputs = ~[];
     let mut inputs = ~[];
@@ -191,7 +192,7 @@ pub fn expand_asm(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
     MRExpr(@ast::Expr {
         id: ast::DUMMY_NODE_ID,
         node: ast::ExprInlineAsm(ast::InlineAsm {
-            asm: asm,
+            asm: asm.get().to_managed(),
             asm_str_style: asm_str_style.unwrap(),
             clobbers: cons.to_managed(),
             inputs: inputs,
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index adf1eabf9d9..eda0a47148a 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -16,7 +16,7 @@ use ext;
 use ext::expand;
 use parse;
 use parse::token;
-use parse::token::{ident_to_str, intern, str_to_ident};
+use parse::token::{InternedString, ident_to_str, intern, str_to_ident};
 use util::small_vector::SmallVector;
 
 use std::hashmap::HashMap;
@@ -407,11 +407,11 @@ impl<'a> ExtCtxt<'a> {
 /// Extract a string literal from `expr`, emitting `err_msg` if `expr`
 /// is not a string literal. This does not stop compilation on error,
 /// merely emits a non-fatal error and returns None.
-pub fn expr_to_str(cx: &ExtCtxt, expr: @ast::Expr,
-                   err_msg: &str) -> Option<(@str, ast::StrStyle)> {
+pub fn expr_to_str(cx: &ExtCtxt, expr: @ast::Expr, err_msg: &str)
+                   -> Option<(InternedString, ast::StrStyle)> {
     match expr.node {
         ast::ExprLit(l) => match l.node {
-            ast::LitStr(s, style) => return Some((s, style)),
+            ast::LitStr(s, style) => return Some(((*s).clone(), style)),
             _ => cx.span_err(l.span, err_msg)
         },
         _ => cx.span_err(expr.span, err_msg)
@@ -424,7 +424,9 @@ pub fn expr_to_str(cx: &ExtCtxt, expr: @ast::Expr,
 /// compilation should call
 /// `cx.parse_sess.span_diagnostic.abort_if_errors()` (this should be
 /// done as rarely as possible).
-pub fn check_zero_tts(cx: &ExtCtxt, sp: Span, tts: &[ast::TokenTree],
+pub fn check_zero_tts(cx: &ExtCtxt,
+                      sp: Span,
+                      tts: &[ast::TokenTree],
                       name: &str) {
     if tts.len() != 0 {
         cx.span_err(sp, format!("{} takes no arguments", name));
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 884bd831ce8..c5ee1948466 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -19,6 +19,7 @@ use fold::Folder;
 use opt_vec;
 use opt_vec::OptVec;
 use parse::token::special_idents;
+use parse::token;
 
 pub struct Field {
     ident: ast::Ident,
@@ -134,13 +135,13 @@ pub trait AstBuilder {
     fn expr_vec(&self, sp: Span, exprs: ~[@ast::Expr]) -> @ast::Expr;
     fn expr_vec_uniq(&self, sp: Span, exprs: ~[@ast::Expr]) -> @ast::Expr;
     fn expr_vec_slice(&self, sp: Span, exprs: ~[@ast::Expr]) -> @ast::Expr;
-    fn expr_str(&self, sp: Span, s: @str) -> @ast::Expr;
-    fn expr_str_uniq(&self, sp: Span, s: @str) -> @ast::Expr;
+    fn expr_str(&self, sp: Span, s: InternedString) -> @ast::Expr;
+    fn expr_str_uniq(&self, sp: Span, s: InternedString) -> @ast::Expr;
 
     fn expr_some(&self, sp: Span, expr: @ast::Expr) -> @ast::Expr;
     fn expr_none(&self, sp: Span) -> @ast::Expr;
 
-    fn expr_fail(&self, span: Span, msg: @str) -> @ast::Expr;
+    fn expr_fail(&self, span: Span, msg: InternedString) -> @ast::Expr;
     fn expr_unreachable(&self, span: Span) -> @ast::Expr;
 
     fn pat(&self, span: Span, pat: ast::Pat_) -> @ast::Pat;
@@ -589,10 +590,10 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     fn expr_vec_slice(&self, sp: Span, exprs: ~[@ast::Expr]) -> @ast::Expr {
         self.expr_vstore(sp, self.expr_vec(sp, exprs), ast::ExprVstoreSlice)
     }
-    fn expr_str(&self, sp: Span, s: @str) -> @ast::Expr {
+    fn expr_str(&self, sp: Span, s: InternedString) -> @ast::Expr {
         self.expr_lit(sp, ast::LitStr(s, ast::CookedStr))
     }
-    fn expr_str_uniq(&self, sp: Span, s: @str) -> @ast::Expr {
+    fn expr_str_uniq(&self, sp: Span, s: InternedString) -> @ast::Expr {
         self.expr_vstore(sp, self.expr_str(sp, s), ast::ExprVstoreUniq)
     }
 
@@ -620,7 +621,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         self.expr_path(none)
     }
 
-    fn expr_fail(&self, span: Span, msg: @str) -> @ast::Expr {
+    fn expr_fail(&self, span: Span, msg: InternedString) -> @ast::Expr {
         let loc = self.codemap().lookup_char_pos(span.lo);
         self.expr_call_global(
             span,
@@ -631,13 +632,16 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             ],
             ~[
                 self.expr_str(span, msg),
-                self.expr_str(span, loc.file.name),
+                self.expr_str(span,
+                              token::intern_and_get_ident(loc.file.name)),
                 self.expr_uint(span, loc.line),
             ])
     }
 
     fn expr_unreachable(&self, span: Span) -> @ast::Expr {
-        self.expr_fail(span, @"internal error: entered unreachable code")
+        self.expr_fail(span,
+                       InternedString::new(
+                           "internal error: entered unreachable code"))
     }
 
 
diff --git a/src/libsyntax/ext/bytes.rs b/src/libsyntax/ext/bytes.rs
index 0c9a23be558..6852a0cec33 100644
--- a/src/libsyntax/ext/bytes.rs
+++ b/src/libsyntax/ext/bytes.rs
@@ -31,8 +31,8 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree]) ->
             // expression is a literal
             ast::ExprLit(lit) => match lit.node {
                 // string literal, push each byte to vector expression
-                ast::LitStr(s, _) => {
-                    for byte in s.bytes() {
+                ast::LitStr(ref s, _) => {
+                    for byte in s.get().bytes() {
                         bytes.push(cx.expr_u8(expr.span, byte));
                     }
                 }
diff --git a/src/libsyntax/ext/concat.rs b/src/libsyntax/ext/concat.rs
index 2a68674af95..f570ca4c1bf 100644
--- a/src/libsyntax/ext/concat.rs
+++ b/src/libsyntax/ext/concat.rs
@@ -14,6 +14,7 @@ use ast;
 use codemap;
 use ext::base;
 use ext::build::AstBuilder;
+use parse::token;
 
 pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
                          sp: codemap::Span,
@@ -28,8 +29,10 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
         match e.node {
             ast::ExprLit(lit) => {
                 match lit.node {
-                    ast::LitStr(s, _) | ast::LitFloat(s, _)
-                    | ast::LitFloatUnsuffixed(s) => {
+                    ast::LitStr(ref s, _) => {
+                        accumulator.push_str(s.get());
+                    }
+                    ast::LitFloat(s, _) | ast::LitFloatUnsuffixed(s) => {
                         accumulator.push_str(s);
                     }
                     ast::LitChar(c) => {
@@ -55,5 +58,5 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
             }
         }
     }
-    return base::MRExpr(cx.expr_str(sp, accumulator.to_managed()));
+    base::MRExpr(cx.expr_str(sp, token::intern_and_get_ident(accumulator)))
 }
diff --git a/src/libsyntax/ext/deriving/decodable.rs b/src/libsyntax/ext/deriving/decodable.rs
index a9268d85c91..019a4dfe7cc 100644
--- a/src/libsyntax/ext/deriving/decodable.rs
+++ b/src/libsyntax/ext/deriving/decodable.rs
@@ -18,6 +18,8 @@ use codemap::Span;
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
 use ext::deriving::generic::*;
+use parse::token::InternedString;
+use parse::token;
 
 pub fn expand_deriving_decodable(cx: &ExtCtxt,
                                  span: Span,
@@ -82,10 +84,15 @@ fn decodable_substructure(cx: &ExtCtxt, trait_span: Span,
                                       cx.expr_uint(span, field),
                                       lambdadecode])
             });
-            cx.expr_method_call(trait_span, decoder, cx.ident_of("read_struct"),
-                                ~[cx.expr_str(trait_span, cx.str_of(substr.type_ident)),
-                                  cx.expr_uint(trait_span, nfields),
-                                  cx.lambda_expr_1(trait_span, result, blkarg)])
+            cx.expr_method_call(trait_span,
+                                decoder,
+                                cx.ident_of("read_struct"),
+                                ~[
+                cx.expr_str(trait_span,
+                            token::get_ident(substr.type_ident.name)),
+                cx.expr_uint(trait_span, nfields),
+                cx.lambda_expr_1(trait_span, result, blkarg)
+            ])
         }
         StaticEnum(_, ref fields) => {
             let variant = cx.ident_of("i");
@@ -95,7 +102,8 @@ fn decodable_substructure(cx: &ExtCtxt, trait_span: Span,
             let rvariant_arg = cx.ident_of("read_enum_variant_arg");
 
             for (i, &(name, v_span, ref parts)) in fields.iter().enumerate() {
-                variants.push(cx.expr_str(v_span, cx.str_of(name)));
+                variants.push(cx.expr_str(v_span,
+                                          token::get_ident(name.name)));
 
                 let decoded = decode_static_fields(cx,
                                                    v_span,
@@ -120,9 +128,14 @@ fn decodable_substructure(cx: &ExtCtxt, trait_span: Span,
             let result = cx.expr_method_call(trait_span, blkdecoder,
                                              cx.ident_of("read_enum_variant"),
                                              ~[variant_vec, lambda]);
-            cx.expr_method_call(trait_span, decoder, cx.ident_of("read_enum"),
-                                ~[cx.expr_str(trait_span, cx.str_of(substr.type_ident)),
-                                  cx.lambda_expr_1(trait_span, result, blkarg)])
+            cx.expr_method_call(trait_span,
+                                decoder,
+                                cx.ident_of("read_enum"),
+                                ~[
+                cx.expr_str(trait_span,
+                            token::get_ident(substr.type_ident.name)),
+                cx.lambda_expr_1(trait_span, result, blkarg)
+            ])
         }
         _ => cx.bug("expected StaticEnum or StaticStruct in deriving(Decodable)")
     };
@@ -135,7 +148,7 @@ fn decode_static_fields(cx: &ExtCtxt,
                         trait_span: Span,
                         outer_pat_ident: Ident,
                         fields: &StaticFields,
-                        getarg: |Span, @str, uint| -> @Expr)
+                        getarg: |Span, InternedString, uint| -> @Expr)
                         -> @Expr {
     match *fields {
         Unnamed(ref fields) => {
@@ -143,7 +156,10 @@ fn decode_static_fields(cx: &ExtCtxt,
                 cx.expr_ident(trait_span, outer_pat_ident)
             } else {
                 let fields = fields.iter().enumerate().map(|(i, &span)| {
-                    getarg(span, format!("_field{}", i).to_managed(), i)
+                    getarg(span,
+                           token::intern_and_get_ident(format!("_field{}",
+                                                               i)),
+                           i)
                 }).collect();
 
                 cx.expr_call_ident(trait_span, outer_pat_ident, fields)
@@ -152,7 +168,9 @@ fn decode_static_fields(cx: &ExtCtxt,
         Named(ref fields) => {
             // use the field's span to get nicer error messages.
             let fields = fields.iter().enumerate().map(|(i, &(name, span))| {
-                cx.field_imm(span, name, getarg(span, cx.str_of(name), i))
+                cx.field_imm(span,
+                             name,
+                             getarg(span, token::get_ident(name.name), i))
             }).collect();
             cx.expr_struct_ident(trait_span, outer_pat_ident, fields)
         }
diff --git a/src/libsyntax/ext/deriving/encodable.rs b/src/libsyntax/ext/deriving/encodable.rs
index 9a8861f2e70..1dfc5b59e06 100644
--- a/src/libsyntax/ext/deriving/encodable.rs
+++ b/src/libsyntax/ext/deriving/encodable.rs
@@ -80,6 +80,7 @@ use codemap::Span;
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
 use ext::deriving::generic::*;
+use parse::token;
 
 pub fn expand_deriving_encodable(cx: &ExtCtxt,
                                  span: Span,
@@ -125,10 +126,17 @@ fn encodable_substructure(cx: &ExtCtxt, trait_span: Span,
         Struct(ref fields) => {
             let emit_struct_field = cx.ident_of("emit_struct_field");
             let mut stmts = ~[];
-            for (i, &FieldInfo { name, self_, span, .. }) in fields.iter().enumerate() {
+            for (i, &FieldInfo {
+                    name,
+                    self_,
+                    span,
+                    ..
+                }) in fields.iter().enumerate() {
                 let name = match name {
-                    Some(id) => cx.str_of(id),
-                    None => format!("_field{}", i).to_managed()
+                    Some(id) => token::get_ident(id),
+                    None => {
+                        token::intern_and_get_ident(format!("_field{}", i))
+                    }
                 };
                 let enc = cx.expr_method_call(span, self_, encode, ~[blkencoder]);
                 let lambda = cx.lambda_expr_1(span, enc, blkarg);
@@ -141,10 +149,15 @@ fn encodable_substructure(cx: &ExtCtxt, trait_span: Span,
             }
 
             let blk = cx.lambda_stmts_1(trait_span, stmts, blkarg);
-            cx.expr_method_call(trait_span, encoder, cx.ident_of("emit_struct"),
-                                ~[cx.expr_str(trait_span, cx.str_of(substr.type_ident)),
-                                  cx.expr_uint(trait_span, fields.len()),
-                                  blk])
+            cx.expr_method_call(trait_span,
+                                encoder,
+                                cx.ident_of("emit_struct"),
+                                ~[
+                cx.expr_str(trait_span,
+                            token::get_ident(substr.type_ident.name)),
+                cx.expr_uint(trait_span, fields.len()),
+                blk
+            ])
         }
 
         EnumMatching(idx, variant, ref fields) => {
@@ -167,7 +180,8 @@ fn encodable_substructure(cx: &ExtCtxt, trait_span: Span,
             }
 
             let blk = cx.lambda_stmts_1(trait_span, stmts, blkarg);
-            let name = cx.expr_str(trait_span, cx.str_of(variant.node.name));
+            let name = cx.expr_str(trait_span,
+                                   token::get_ident(variant.node.name));
             let call = cx.expr_method_call(trait_span, blkencoder,
                                            cx.ident_of("emit_enum_variant"),
                                            ~[name,
@@ -175,11 +189,14 @@ fn encodable_substructure(cx: &ExtCtxt, trait_span: Span,
                                              cx.expr_uint(trait_span, fields.len()),
                                              blk]);
             let blk = cx.lambda_expr_1(trait_span, call, blkarg);
-            let ret = cx.expr_method_call(trait_span, encoder,
+            let ret = cx.expr_method_call(trait_span,
+                                          encoder,
                                           cx.ident_of("emit_enum"),
-                                          ~[cx.expr_str(trait_span,
-                                            cx.str_of(substr.type_ident)),
-                                            blk]);
+                                          ~[
+                cx.expr_str(trait_span,
+                            token::get_ident(substr.type_ident.name)),
+                blk
+            ]);
             cx.expr_block(cx.block(trait_span, ~[me], Some(ret)))
         }
 
diff --git a/src/libsyntax/ext/deriving/generic.rs b/src/libsyntax/ext/deriving/generic.rs
index 20a515692e1..45e3be7f23d 100644
--- a/src/libsyntax/ext/deriving/generic.rs
+++ b/src/libsyntax/ext/deriving/generic.rs
@@ -185,6 +185,7 @@ use codemap;
 use codemap::Span;
 use opt_vec;
 use parse::token::InternedString;
+use parse::token;
 
 use std::vec;
 
@@ -398,7 +399,9 @@ impl<'a> TraitDef<'a> {
             self.span,
             cx.meta_name_value(self.span,
                                InternedString::new("doc"),
-                               ast::LitStr(@"Automatically derived.", ast::CookedStr)));
+                               ast::LitStr(token::intern_and_get_ident(
+                                       "Automatically derived."),
+                                       ast::CookedStr)));
         cx.item(
             self.span,
             ::parse::token::special_idents::clownshoes_extensions,
diff --git a/src/libsyntax/ext/deriving/primitive.rs b/src/libsyntax/ext/deriving/primitive.rs
index a4e606f53c0..e2f72e87085 100644
--- a/src/libsyntax/ext/deriving/primitive.rs
+++ b/src/libsyntax/ext/deriving/primitive.rs
@@ -14,6 +14,7 @@ use codemap::Span;
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
 use ext::deriving::generic::*;
+use parse::token::InternedString;
 
 pub fn expand_deriving_from_primitive(cx: &ExtCtxt,
                                       span: Span,
@@ -73,13 +74,13 @@ fn cs_from(name: &str, cx: &ExtCtxt, trait_span: Span, substr: &Substructure) ->
     match *substr.fields {
         StaticStruct(..) => {
             cx.span_err(trait_span, "`FromPrimitive` cannot be derived for structs");
-            return cx.expr_fail(trait_span, @"");
+            return cx.expr_fail(trait_span, InternedString::new(""));
         }
         StaticEnum(enum_def, _) => {
             if enum_def.variants.is_empty() {
                 cx.span_err(trait_span,
                             "`FromPrimitive` cannot be derived for enums with no variants");
-                return cx.expr_fail(trait_span, @"");
+                return cx.expr_fail(trait_span, InternedString::new(""));
             }
 
             let mut arms = ~[];
@@ -91,7 +92,8 @@ fn cs_from(name: &str, cx: &ExtCtxt, trait_span: Span, substr: &Substructure) ->
                             cx.span_err(trait_span,
                                         "`FromPrimitive` cannot be derived for \
                                         enum variants with arguments");
-                            return cx.expr_fail(trait_span, @"");
+                            return cx.expr_fail(trait_span,
+                                                InternedString::new(""));
                         }
                         let span = variant.span;
 
@@ -117,7 +119,8 @@ fn cs_from(name: &str, cx: &ExtCtxt, trait_span: Span, substr: &Substructure) ->
                         cx.span_err(trait_span,
                                     "`FromPrimitive` cannot be derived for enums \
                                     with struct variants");
-                        return cx.expr_fail(trait_span, @"");
+                        return cx.expr_fail(trait_span,
+                                            InternedString::new(""));
                     }
                 }
             }
diff --git a/src/libsyntax/ext/deriving/to_str.rs b/src/libsyntax/ext/deriving/to_str.rs
index 81453a5a10b..97412595b29 100644
--- a/src/libsyntax/ext/deriving/to_str.rs
+++ b/src/libsyntax/ext/deriving/to_str.rs
@@ -14,6 +14,8 @@ use codemap::Span;
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
 use ext::deriving::generic::*;
+use parse::token::InternedString;
+use parse::token;
 
 pub fn expand_deriving_to_str(cx: &ExtCtxt,
                               span: Span,
@@ -47,18 +49,20 @@ pub fn expand_deriving_to_str(cx: &ExtCtxt,
 // doesn't invoke the to_str() method on each field. Hence we mirror
 // the logic of the repr_to_str() method, but with tweaks to call to_str()
 // on sub-fields.
-fn to_str_substructure(cx: &ExtCtxt, span: Span,
-                       substr: &Substructure) -> @Expr {
+fn to_str_substructure(cx: &ExtCtxt, span: Span, substr: &Substructure)
+                       -> @Expr {
     let to_str = cx.ident_of("to_str");
 
-    let doit = |start: &str, end: @str, name: ast::Ident,
+    let doit = |start: &str,
+                end: InternedString,
+                name: ast::Ident,
                 fields: &[FieldInfo]| {
         if fields.len() == 0 {
-            cx.expr_str_uniq(span, cx.str_of(name))
+            cx.expr_str_uniq(span, token::get_ident(name.name))
         } else {
             let buf = cx.ident_of("buf");
-            let start = cx.str_of(name) + start;
-            let init = cx.expr_str_uniq(span, start.to_managed());
+            let start = token::intern_and_get_ident(cx.str_of(name) + start);
+            let init = cx.expr_str_uniq(span, start);
             let mut stmts = ~[cx.stmt_let(span, true, buf, init)];
             let push_str = cx.ident_of("push_str");
 
@@ -70,38 +74,52 @@ fn to_str_substructure(cx: &ExtCtxt, span: Span,
 
             for (i, &FieldInfo {name, span, self_, .. }) in fields.iter().enumerate() {
                 if i > 0 {
-                    push(cx.expr_str(span, @", "));
+                    push(cx.expr_str(span, InternedString::new(", ")));
                 }
                 match name {
                     None => {}
                     Some(id) => {
                         let name = cx.str_of(id) + ": ";
-                        push(cx.expr_str(span, name.to_managed()));
+                        push(cx.expr_str(span,
+                                         token::intern_and_get_ident(name)));
                     }
                 }
                 push(cx.expr_method_call(span, self_, to_str, ~[]));
             }
             push(cx.expr_str(span, end));
 
-            cx.expr_block(cx.block(span, stmts, Some(cx.expr_ident(span, buf))))
+            cx.expr_block(cx.block(span, stmts, Some(cx.expr_ident(span,
+                                                                   buf))))
         }
     };
 
     return match *substr.fields {
         Struct(ref fields) => {
             if fields.len() == 0 || fields[0].name.is_none() {
-                doit("(", @")", substr.type_ident, *fields)
+                doit("(",
+                     InternedString::new(")"),
+                     substr.type_ident,
+                     *fields)
             } else {
-                doit("{", @"}", substr.type_ident, *fields)
+                doit("{",
+                     InternedString::new("}"),
+                     substr.type_ident,
+                     *fields)
             }
         }
 
         EnumMatching(_, variant, ref fields) => {
             match variant.node.kind {
                 ast::TupleVariantKind(..) =>
-                    doit("(", @")", variant.node.name, *fields),
+                    doit("(",
+                         InternedString::new(")"),
+                         variant.node.name,
+                         *fields),
                 ast::StructVariantKind(..) =>
-                    doit("{", @"}", variant.node.name, *fields),
+                    doit("{",
+                         InternedString::new("}"),
+                         variant.node.name,
+                         *fields),
             }
         }
 
diff --git a/src/libsyntax/ext/env.rs b/src/libsyntax/ext/env.rs
index a9b40ea7ec6..c23a1ce1e28 100644
--- a/src/libsyntax/ext/env.rs
+++ b/src/libsyntax/ext/env.rs
@@ -19,6 +19,7 @@ use codemap::Span;
 use ext::base::*;
 use ext::base;
 use ext::build::AstBuilder;
+use parse::token;
 
 use std::os;
 
@@ -52,7 +53,11 @@ pub fn expand_env(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
         Some((v, _style)) => v
     };
     let msg = match exprs.len() {
-        1 => format!("environment variable `{}` not defined", var).to_managed(),
+        1 => {
+            token::intern_and_get_ident(format!("environment variable `{}` \
+                                                 not defined",
+                                                var))
+        }
         2 => {
             match expr_to_str(cx, exprs[1], "expected string literal") {
                 None => return MacResult::dummy_expr(),
@@ -65,12 +70,12 @@ pub fn expand_env(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
         }
     };
 
-    let e = match os::getenv(var) {
+    let e = match os::getenv(var.get()) {
         None => {
-            cx.span_err(sp, msg);
+            cx.span_err(sp, msg.get());
             cx.expr_uint(sp, 0)
         }
-        Some(s) => cx.expr_str(sp, s.to_managed())
+        Some(s) => cx.expr_str(sp, token::intern_and_get_ident(s))
     };
     MRExpr(e)
 }
diff --git a/src/libsyntax/ext/format.rs b/src/libsyntax/ext/format.rs
index 5730d435c15..5bedb1a887e 100644
--- a/src/libsyntax/ext/format.rs
+++ b/src/libsyntax/ext/format.rs
@@ -416,7 +416,7 @@ impl<'a> Context<'a> {
                         let result = arm.result.iter().map(|p| {
                             self.trans_piece(p)
                         }).collect();
-                        let s = arm.selector.to_managed();
+                        let s = token::intern_and_get_ident(arm.selector);
                         let selector = self.ecx.expr_str(sp, s);
                         self.ecx.expr_struct(sp, p, ~[
                             self.ecx.field_imm(sp,
@@ -492,8 +492,12 @@ impl<'a> Context<'a> {
 
         match *piece {
             parse::String(s) => {
-                self.ecx.expr_call_global(sp, rtpath("String"),
-                                          ~[self.ecx.expr_str(sp, s.to_managed())])
+                let s = token::intern_and_get_ident(s);
+                self.ecx.expr_call_global(sp,
+                                          rtpath("String"),
+                                          ~[
+                    self.ecx.expr_str(sp, s)
+                ])
             }
             parse::CurrentArgument => {
                 let nil = self.ecx.expr_lit(sp, ast::LitNil);
@@ -763,8 +767,9 @@ pub fn expand_args(ecx: &mut ExtCtxt, sp: Span,
     // Be sure to recursively expand macros just in case the format string uses
     // a macro to build the format expression.
     let expr = cx.ecx.expand_expr(efmt);
-    let fmt = match expr_to_str(cx.ecx, expr,
-                                     "format argument must be a string literal.") {
+    let fmt = match expr_to_str(cx.ecx,
+                                expr,
+                                "format argument must be a string literal.") {
         Some((fmt, _)) => fmt,
         None => return MacResult::dummy_expr()
     };
@@ -776,7 +781,7 @@ pub fn expand_args(ecx: &mut ExtCtxt, sp: Span,
             cx.ecx.span_err(efmt.span, m);
         }
     }).inside(|| {
-        for piece in parse::Parser::new(fmt) {
+        for piece in parse::Parser::new(fmt.get()) {
             if !err {
                 cx.verify_piece(&piece);
                 let piece = cx.trans_piece(&piece);
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 6faed270875..425ac8865b2 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -31,6 +31,7 @@ use parse;
 pub mod rt {
     use ast;
     use ext::base::ExtCtxt;
+    use parse::token;
     use parse;
     use print::pprust;
 
@@ -118,7 +119,8 @@ pub mod rt {
 
     impl<'a> ToSource for &'a str {
         fn to_source(&self) -> @str {
-            let lit = dummy_spanned(ast::LitStr(self.to_managed(), ast::CookedStr));
+            let lit = dummy_spanned(ast::LitStr(
+                    token::intern_and_get_ident(*self), ast::CookedStr));
             pprust::lit_to_str(&lit).to_managed()
         }
     }
@@ -349,7 +351,7 @@ fn id_ext(str: &str) -> ast::Ident {
 
 // Lift an ident to the expr that evaluates to that ident.
 fn mk_ident(cx: &ExtCtxt, sp: Span, ident: ast::Ident) -> @ast::Expr {
-    let e_str = cx.expr_str(sp, cx.str_of(ident));
+    let e_str = cx.expr_str(sp, token::get_ident(ident.name));
     cx.expr_method_call(sp,
                         cx.expr_ident(sp, id_ext("ext_cx")),
                         id_ext("ident_of"),
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index a9f94da7a98..b67f3ed263e 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -16,7 +16,8 @@ use ext::base::*;
 use ext::base;
 use ext::build::AstBuilder;
 use parse;
-use parse::token::{get_ident_interner};
+use parse::token::get_ident_interner;
+use parse::token;
 use print::pprust;
 
 use std::io;
@@ -57,21 +58,21 @@ pub fn expand_file(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
 
     let topmost = topmost_expn_info(cx.backtrace().unwrap());
     let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
-    let filename = loc.file.name;
+    let filename = token::intern_and_get_ident(loc.file.name);
     base::MRExpr(cx.expr_str(topmost.call_site, filename))
 }
 
 pub fn expand_stringify(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
     -> base::MacResult {
     let s = pprust::tts_to_str(tts, get_ident_interner());
-    base::MRExpr(cx.expr_str(sp, s.to_managed()))
+    base::MRExpr(cx.expr_str(sp, token::intern_and_get_ident(s)))
 }
 
 pub fn expand_mod(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
     -> base::MacResult {
     base::check_zero_tts(cx, sp, tts, "module_path!");
-    base::MRExpr(cx.expr_str(sp,
-                             cx.mod_path().map(|x| cx.str_of(*x)).connect("::").to_managed()))
+    let string = cx.mod_path().map(|x| cx.str_of(*x)).connect("::");
+    base::MRExpr(cx.expr_str(sp, token::intern_and_get_ident(string)))
 }
 
 // include! : parse the given file as an expr
@@ -117,7 +118,7 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             let filename = file.display().to_str().to_managed();
             cx.parse_sess.cm.new_filemap(filename, src);
 
-            base::MRExpr(cx.expr_str(sp, src))
+            base::MRExpr(cx.expr_str(sp, token::intern_and_get_ident(src)))
         }
         None => {
             cx.span_err(sp, format!("{} wasn't a utf-8 file", file.display()));
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index c2d54a4f368..9a346e17d28 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -326,7 +326,9 @@ fn fold_meta_item_<T: Folder>(mi: @MetaItem, fld: &mut T) -> @MetaItem {
                     let fold_meta_item = |x| fold_meta_item_(x, fld);
                     MetaList((*id).clone(), mis.map(|e| fold_meta_item(*e)))
                 }
-                MetaNameValue(ref id, s) => MetaNameValue((*id).clone(), s)
+                MetaNameValue(ref id, ref s) => {
+                    MetaNameValue((*id).clone(), (*s).clone())
+                }
             },
         span: fld.new_span(mi.span) }
 }
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index bc9f7e4b195..c9bea78d02d 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -45,7 +45,7 @@ impl ParserAttr for Parser {
               }
               token::DOC_COMMENT(s) => {
                 let attr = ::attr::mk_sugared_doc_attr(
-                    self.id_to_str(s),
+                    self.id_to_interned_str(s),
                     self.span.lo,
                     self.span.hi
                 );
@@ -133,7 +133,7 @@ impl ParserAttr for Parser {
                 }
                 token::DOC_COMMENT(s) => {
                     self.bump();
-                    ::attr::mk_sugared_doc_attr(self.id_to_str(s),
+                    ::attr::mk_sugared_doc_attr(self.id_to_interned_str(s),
                                                 self.span.lo,
                                                 self.span.hi)
                 }
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index aa5e4e01ae0..21a34ab5e1e 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -54,7 +54,6 @@ pub fn doc_comment_style(comment: &str) -> ast::AttrStyle {
 }
 
 pub fn strip_doc_comment_decoration(comment: &str) -> ~str {
-
     /// remove whitespace-only lines from the start/end of lines
     fn vertical_trim(lines: ~[~str]) -> ~[~str] {
         let mut i = 0u;
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 93264f5a6c6..636dc504ff2 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -345,7 +345,7 @@ pub struct Parser {
     /// extra detail when the same error is seen twice
     obsolete_set: HashSet<ObsoleteSyntax>,
     /// Used to determine the path to externally loaded source files
-    mod_path_stack: ~[@str],
+    mod_path_stack: ~[InternedString],
     /// Stack of spans of open delimiters. Used for error message.
     open_braces: ~[Span],
     /* do not copy the parser; its state is tied to outside state */
@@ -1408,8 +1408,12 @@ impl Parser {
             token::LIT_FLOAT(s, ft) => LitFloat(self.id_to_str(s), ft),
             token::LIT_FLOAT_UNSUFFIXED(s) =>
                 LitFloatUnsuffixed(self.id_to_str(s)),
-            token::LIT_STR(s) => LitStr(self.id_to_str(s), ast::CookedStr),
-            token::LIT_STR_RAW(s, n) => LitStr(self.id_to_str(s), ast::RawStr(n)),
+            token::LIT_STR(s) => {
+                LitStr(self.id_to_interned_str(s), ast::CookedStr)
+            }
+            token::LIT_STR_RAW(s, n) => {
+                LitStr(self.id_to_interned_str(s), ast::RawStr(n))
+            }
             token::LPAREN => { self.expect(&token::RPAREN); LitNil },
             _ => { self.unexpected_last(tok); }
         }
@@ -4146,11 +4150,11 @@ impl Parser {
     }
 
     fn push_mod_path(&mut self, id: Ident, attrs: &[Attribute]) {
-        let default_path = token::interner_get(id.name);
+        let default_path = self.id_to_interned_str(id);
         let file_path = match ::attr::first_attr_value_str_by_name(attrs,
                                                                    "path") {
             Some(d) => d,
-            None => default_path
+            None => default_path,
         };
         self.mod_path_stack.push(file_path)
     }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 97b9b4d53a4..9291cba54f6 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -20,6 +20,7 @@ use std::cast;
 use std::char;
 use std::fmt;
 use std::local_data;
+use std::path::BytesContainer;
 
 #[allow(non_camel_case_types)]
 #[deriving(Clone, Encodable, Decodable, Eq, IterBytes)]
@@ -537,7 +538,7 @@ pub fn get_ident_interner() -> @IdentInterner {
 /// be fixed in the future by just leaking all strings until task death
 /// somehow.
 #[no_send]
-#[deriving(Clone, Eq, IterBytes, TotalEq, TotalOrd)]
+#[deriving(Clone, Eq, IterBytes, Ord, TotalEq, TotalOrd)]
 pub struct InternedString {
     priv string: @str,
 }
@@ -571,6 +572,17 @@ impl InternedString {
     }
 }
 
+impl BytesContainer for InternedString {
+    fn container_as_bytes<'a>(&'a self) -> &'a [u8] {
+        // XXX(pcwalton): This is a workaround for the incorrect signature of
+        // `BytesContainer`, which is itself a workaround for the lack of DST.
+        unsafe {
+            let this = self.get();
+            cast::transmute(this.container_as_bytes())
+        }
+    }
+}
+
 impl fmt::Default for InternedString {
     fn fmt(obj: &InternedString, f: &mut fmt::Formatter) {
         write!(f.buf, "{}", obj.string);
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 89d8173f7e7..32b0766249e 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -897,7 +897,7 @@ pub fn print_attribute(s: &mut State, attr: &ast::Attribute) {
     maybe_print_comment(s, attr.span.lo);
     if attr.node.is_sugared_doc {
         let comment = attr.value_str().unwrap();
-        word(&mut s.s, comment);
+        word(&mut s.s, comment.get());
     } else {
         word(&mut s.s, "#[");
         print_meta_item(s, attr.meta());
@@ -1931,10 +1931,10 @@ pub fn print_meta_item(s: &mut State, item: &ast::MetaItem) {
     ibox(s, indent_unit);
     match item.node {
       ast::MetaWord(ref name) => word(&mut s.s, name.get()),
-      ast::MetaNameValue(ref name, value) => {
+      ast::MetaNameValue(ref name, ref value) => {
         word_space(s, name.get());
         word_space(s, "=");
-        print_literal(s, &value);
+        print_literal(s, value);
       }
       ast::MetaList(ref name, ref items) => {
         word(&mut s.s, name.get());
@@ -2172,7 +2172,7 @@ pub fn print_literal(s: &mut State, lit: &ast::Lit) {
       _ => ()
     }
     match lit.node {
-      ast::LitStr(st, style) => print_string(s, st, style),
+      ast::LitStr(ref st, style) => print_string(s, st.get(), style),
       ast::LitChar(ch) => {
           let mut res = ~"'";
           char::from_u32(ch).unwrap().escape_default(|c| res.push_char(c));