De-@ codemap and diagnostic.

33 files changed, 311 insertions, 356 deletions

diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
index 13625993200..edb9d11b11a 100644
--- a/src/librustc/back/link.rs
+++ b/src/librustc/back/link.rs
@@ -1352,9 +1352,8 @@ fn add_upstream_rust_crates(args: &mut Vec<~str>, sess: &Session,
     }
 
     // Converts a library file-stem into a cc -l argument
-    fn unlib(config: @session::Config, stem: &str) -> ~str {
-        if stem.starts_with("lib") &&
-            config.os != abi::OsWin32 {
+    fn unlib(config: &session::Config, stem: &str) -> ~str {
+        if stem.starts_with("lib") && config.os != abi::OsWin32 {
             stem.slice(3, stem.len()).to_owned()
         } else {
             stem.to_owned()
@@ -1434,7 +1433,7 @@ fn add_upstream_rust_crates(args: &mut Vec<~str>, sess: &Session,
             // what its name is
             let dir = cratepath.dirname_str().unwrap();
             if !dir.is_empty() { args.push("-L" + dir); }
-            let libarg = unlib(sess.targ_cfg, cratepath.filestem_str().unwrap());
+            let libarg = unlib(&sess.targ_cfg, cratepath.filestem_str().unwrap());
             args.push("-l" + libarg);
         }
     }
diff --git a/src/librustc/driver/driver.rs b/src/librustc/driver/driver.rs
index 7ffbab4c9b3..a14fda080bb 100644
--- a/src/librustc/driver/driver.rs
+++ b/src/librustc/driver/driver.rs
@@ -27,7 +27,7 @@ use middle::{trans, freevars, kind, ty, typeck, lint, astencode, reachable};
 use middle;
 use util::common::time;
 use util::ppaux;
-use util::nodemap::NodeSet;
+use util::nodemap::{NodeMap, NodeSet};
 
 use serialize::{json, Encodable};
 
@@ -39,7 +39,6 @@ use std::mem::drop;
 use std::os;
 use std::vec_ng::Vec;
 use std::vec_ng;
-use collections::HashMap;
 use getopts::{optopt, optmulti, optflag, optflagopt};
 use getopts;
 use syntax::ast;
@@ -75,9 +74,9 @@ pub fn anon_src() -> ~str {
 
 pub fn source_name(input: &Input) -> ~str {
     match *input {
-      // FIXME (#9639): This needs to handle non-utf8 paths
-      FileInput(ref ifile) => ifile.as_str().unwrap().to_str(),
-      StrInput(_) => anon_src()
+        // FIXME (#9639): This needs to handle non-utf8 paths
+        FileInput(ref ifile) => ifile.as_str().unwrap().to_str(),
+        StrInput(_) => anon_src()
     }
 }
 
@@ -213,7 +212,7 @@ pub fn phase_2_configure_and_expand(sess: &Session,
                                     -> (ast::Crate, syntax::ast_map::Map) {
     let time_passes = sess.time_passes();
 
-    sess.building_library.set(session::building_library(sess.opts, &krate));
+    sess.building_library.set(session::building_library(&sess.opts, &krate));
     sess.crate_types.set(session::collect_crate_types(sess,
                                                       krate.attrs
                                                            .as_slice()));
@@ -315,7 +314,7 @@ pub fn phase_3_run_analysis_passes(sess: Session,
     sess.macro_registrar_fn.with_mut(|r| *r =
         time(time_passes, "looking for macro registrar", (), |_|
             syntax::ext::registrar::find_macro_registrar(
-                sess.span_diagnostic, krate)));
+                sess.diagnostic(), krate)));
 
     let freevars = time(time_passes, "freevar finding", (), |_|
                         freevars::annotate_freevars(def_map, krate));
@@ -541,19 +540,14 @@ fn write_out_deps(sess: &Session,
 
     // Build a list of files used to compile the output and
     // write Makefile-compatible dependency rules
-    let files: Vec<~str> = {
-        let files = sess.codemap.files.borrow();
-        files.get()
-             .iter()
-             .filter_map(|fmap| {
-                 if fmap.is_real_file() {
-                     Some(fmap.name.clone())
-                 } else {
-                     None
-                 }
-             })
-             .collect()
-    };
+    let files: Vec<~str> = sess.codemap().files.borrow().get()
+                               .iter().filter_map(|fmap| {
+                                    if fmap.deref().is_real_file() {
+                                        Some(fmap.deref().name.clone())
+                                    } else {
+                                        None
+                                    }
+                                }).collect();
     let mut file = try!(io::File::create(&deps_filename));
     for path in out_filenames.iter() {
         try!(write!(&mut file as &mut Writer,
@@ -741,8 +735,7 @@ static architecture_abis : &'static [(&'static str, abi::Architecture)] = &'stat
 
     ("mips",   abi::Mips)];
 
-pub fn build_target_config(sopts: @session::Options)
-                           -> @session::Config {
+pub fn build_target_config(sopts: &session::Options) -> session::Config {
     let os = match get_os(sopts.target_triple) {
       Some(os) => os,
       None => early_error("unknown operating system")
@@ -764,14 +757,13 @@ pub fn build_target_config(sopts: @session::Options)
       abi::Arm => arm::get_target_strs(target_triple, os),
       abi::Mips => mips::get_target_strs(target_triple, os)
     };
-    let target_cfg = @session::Config {
+    session::Config {
         os: os,
         arch: arch,
         target_strs: target_strs,
         int_type: int_type,
         uint_type: uint_type,
-    };
-    return target_cfg;
+    }
 }
 
 pub fn host_triple() -> ~str {
@@ -938,7 +930,7 @@ pub fn build_session_options(matches: &getopts::Matches)
                        matches.opt_present("crate-file-name"));
     let cg = build_codegen_options(matches);
 
-    @session::Options {
+    session::Options {
         crate_types: crate_types,
         gc: gc,
         optimize: opt_level,
@@ -991,25 +983,24 @@ pub fn build_codegen_options(matches: &getopts::Matches)
     return cg;
 }
 
-pub fn build_session(sopts: @session::Options,
+pub fn build_session(sopts: session::Options,
                      local_crate_source_file: Option<Path>)
                      -> Session {
-    let codemap = @codemap::CodeMap::new();
+    let codemap = codemap::CodeMap::new();
     let diagnostic_handler =
         diagnostic::default_handler();
     let span_diagnostic_handler =
         diagnostic::mk_span_handler(diagnostic_handler, codemap);
 
-    build_session_(sopts, local_crate_source_file, codemap, span_diagnostic_handler)
+    build_session_(sopts, local_crate_source_file, span_diagnostic_handler)
 }
 
-pub fn build_session_(sopts: @session::Options,
+pub fn build_session_(sopts: session::Options,
                       local_crate_source_file: Option<Path>,
-                      codemap: @codemap::CodeMap,
-                      span_diagnostic_handler: @diagnostic::SpanHandler)
+                      span_diagnostic: diagnostic::SpanHandler)
                       -> Session {
-    let target_cfg = build_target_config(sopts);
-    let p_s = parse::new_parse_sess_special_handler(span_diagnostic_handler, codemap);
+    let target_cfg = build_target_config(&sopts);
+    let p_s = parse::new_parse_sess_special_handler(span_diagnostic);
     let default_sysroot = match sopts.maybe_sysroot {
         Some(_) => None,
         None => Some(filesearch::get_or_default_sysroot())
@@ -1029,19 +1020,17 @@ pub fn build_session_(sopts: @session::Options,
         opts: sopts,
         cstore: CStore::new(token::get_ident_interner()),
         parse_sess: p_s,
-        codemap: codemap,
         // For a library crate, this is always none
         entry_fn: RefCell::new(None),
         entry_type: Cell::new(None),
         macro_registrar_fn: RefCell::new(None),
-        span_diagnostic: span_diagnostic_handler,
         default_sysroot: default_sysroot,
         building_library: Cell::new(false),
         local_crate_source_file: local_crate_source_file,
         working_dir: os::getcwd(),
-        lints: RefCell::new(HashMap::new()),
+        lints: RefCell::new(NodeMap::new()),
         node_id: Cell::new(1),
-        crate_types: @RefCell::new(Vec::new()),
+        crate_types: RefCell::new(Vec::new()),
         features: front::feature_gate::Features::new(),
         recursion_limit: Cell::new(64),
     }
diff --git a/src/librustc/driver/session.rs b/src/librustc/driver/session.rs
index acc92221539..8d3048a80b2 100644
--- a/src/librustc/driver/session.rs
+++ b/src/librustc/driver/session.rs
@@ -16,6 +16,7 @@ use front;
 use metadata::filesearch;
 use metadata;
 use middle::lint;
+use util::nodemap::NodeMap;
 
 use syntax::attr::AttrMetaMethods;
 use syntax::ast::NodeId;
@@ -28,7 +29,7 @@ use syntax;
 
 use std::cell::{Cell, RefCell};
 use std::vec_ng::Vec;
-use collections::{HashMap,HashSet};
+use collections::HashSet;
 
 pub struct Config {
     os: abi::Os,
@@ -174,15 +175,13 @@ pub enum CrateType {
 }
 
 pub struct Session {
-    targ_cfg: @Config,
-    opts: @Options,
+    targ_cfg: Config,
+    opts: Options,
     cstore: metadata::cstore::CStore,
     parse_sess: ParseSess,
-    codemap: @codemap::CodeMap,
     // For a library crate, this is always none
     entry_fn: RefCell<Option<(NodeId, codemap::Span)>>,
     entry_type: Cell<Option<EntryFnType>>,
-    span_diagnostic: @diagnostic::SpanHandler,
     macro_registrar_fn: RefCell<Option<ast::DefId>>,
     default_sysroot: Option<Path>,
     building_library: Cell<bool>,
@@ -190,10 +189,9 @@ pub struct Session {
     // expected to be absolute. `None` means that there is no source file.
     local_crate_source_file: Option<Path>,
     working_dir: Path,
-    lints: RefCell<HashMap<ast::NodeId,
-                           Vec<(lint::Lint, codemap::Span, ~str)> >>,
+    lints: RefCell<NodeMap<Vec<(lint::Lint, codemap::Span, ~str)>>>,
     node_id: Cell<ast::NodeId>,
-    crate_types: @RefCell<Vec<CrateType> >,
+    crate_types: RefCell<Vec<CrateType>>,
     features: front::feature_gate::Features,
 
     /// The maximum recursion limit for potentially infinitely recursive
@@ -203,52 +201,52 @@ pub struct Session {
 
 impl Session {
     pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
-        self.span_diagnostic.span_fatal(sp, msg)
+        self.diagnostic().span_fatal(sp, msg)
     }
     pub fn fatal(&self, msg: &str) -> ! {
-        self.span_diagnostic.handler().fatal(msg)
+        self.diagnostic().handler().fatal(msg)
     }
     pub fn span_err(&self, sp: Span, msg: &str) {
-        self.span_diagnostic.span_err(sp, msg)
+        self.diagnostic().span_err(sp, msg)
     }
     pub fn err(&self, msg: &str) {
-        self.span_diagnostic.handler().err(msg)
+        self.diagnostic().handler().err(msg)
     }
     pub fn err_count(&self) -> uint {
-        self.span_diagnostic.handler().err_count()
+        self.diagnostic().handler().err_count()
     }
     pub fn has_errors(&self) -> bool {
-        self.span_diagnostic.handler().has_errors()
+        self.diagnostic().handler().has_errors()
     }
     pub fn abort_if_errors(&self) {
-        self.span_diagnostic.handler().abort_if_errors()
+        self.diagnostic().handler().abort_if_errors()
     }
     pub fn span_warn(&self, sp: Span, msg: &str) {
-        self.span_diagnostic.span_warn(sp, msg)
+        self.diagnostic().span_warn(sp, msg)
     }
     pub fn warn(&self, msg: &str) {
-        self.span_diagnostic.handler().warn(msg)
+        self.diagnostic().handler().warn(msg)
     }
     pub fn span_note(&self, sp: Span, msg: &str) {
-        self.span_diagnostic.span_note(sp, msg)
+        self.diagnostic().span_note(sp, msg)
     }
     pub fn span_end_note(&self, sp: Span, msg: &str) {
-        self.span_diagnostic.span_end_note(sp, msg)
+        self.diagnostic().span_end_note(sp, msg)
     }
     pub fn note(&self, msg: &str) {
-        self.span_diagnostic.handler().note(msg)
+        self.diagnostic().handler().note(msg)
     }
     pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
-        self.span_diagnostic.span_bug(sp, msg)
+        self.diagnostic().span_bug(sp, msg)
     }
     pub fn bug(&self, msg: &str) -> ! {
-        self.span_diagnostic.handler().bug(msg)
+        self.diagnostic().handler().bug(msg)
     }
     pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
-        self.span_diagnostic.span_unimpl(sp, msg)
+        self.diagnostic().span_unimpl(sp, msg)
     }
     pub fn unimpl(&self, msg: &str) -> ! {
-        self.span_diagnostic.handler().unimpl(msg)
+        self.diagnostic().handler().unimpl(msg)
     }
     pub fn add_lint(&self,
                     lint: lint::Lint,
@@ -275,12 +273,15 @@ impl Session {
 
         v
     }
-    pub fn diagnostic(&self) -> @diagnostic::SpanHandler {
-        self.span_diagnostic
+    pub fn diagnostic<'a>(&'a self) -> &'a diagnostic::SpanHandler {
+        &self.parse_sess.span_diagnostic
     }
     pub fn debugging_opt(&self, opt: u64) -> bool {
         (self.opts.debugging_opts & opt) != 0
     }
+    pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
+        &self.parse_sess.span_diagnostic.cm
+    }
     // This exists to help with refactoring to eliminate impossible
     // cases later on
     pub fn impossible_case(&self, sp: Span, msg: &str) -> ! {
@@ -328,8 +329,8 @@ impl Session {
 }
 
 /// Some reasonable defaults
-pub fn basic_options() -> @Options {
-    @Options {
+pub fn basic_options() -> Options {
+    Options {
         crate_types: Vec::new(),
         gc: false,
         optimize: No,
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 4383f3f5933..9409d8c457f 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -295,26 +295,26 @@ pub fn run_compiler(args: &[~str]) {
         d::parse_pretty(&sess, a)
     });
     match pretty {
-      Some::<d::PpMode>(ppm) => {
-        d::pretty_print_input(sess, cfg, &input, ppm);
-        return;
-      }
-      None::<d::PpMode> => {/* continue */ }
+        Some::<d::PpMode>(ppm) => {
+            d::pretty_print_input(sess, cfg, &input, ppm);
+            return;
+        }
+        None::<d::PpMode> => {/* continue */ }
     }
     let ls = matches.opt_present("ls");
     if ls {
         match input {
-          d::FileInput(ref ifile) => {
-            let mut stdout = io::stdout();
-            d::list_metadata(&sess, &(*ifile), &mut stdout).unwrap();
-          }
-          d::StrInput(_) => {
-            d::early_error("can not list metadata for stdin");
-          }
+            d::FileInput(ref ifile) => {
+                let mut stdout = io::stdout();
+                d::list_metadata(&sess, &(*ifile), &mut stdout).unwrap();
+            }
+            d::StrInput(_) => {
+                d::early_error("can not list metadata for stdin");
+            }
         }
         return;
     }
-    let (crate_id, crate_name, crate_file_name) = sopts.print_metas;
+    let (crate_id, crate_name, crate_file_name) = sess.opts.print_metas;
     // these nasty nested conditions are to avoid doing extra work
     if crate_id || crate_name || crate_file_name {
         let attrs = parse_crate_attrs(&sess, &input);
diff --git a/src/librustc/metadata/creader.rs b/src/librustc/metadata/creader.rs
index 359f28f2ad1..74e180072fa 100644
--- a/src/librustc/metadata/creader.rs
+++ b/src/librustc/metadata/creader.rs
@@ -88,7 +88,7 @@ fn dump_crates(crate_cache: &[cache_entry]) {
 }
 
 fn warn_if_multiple_versions(e: &mut Env,
-                             diag: @SpanHandler,
+                             diag: &SpanHandler,
                              crate_cache: &[cache_entry]) {
     if crate_cache.len() != 0u {
         let name = crate_cache[crate_cache.len() - 1].crate_id.name.clone();
diff --git a/src/librustc/metadata/csearch.rs b/src/librustc/metadata/csearch.rs
index 95c85a04b19..d41d01f3c85 100644
--- a/src/librustc/metadata/csearch.rs
+++ b/src/librustc/metadata/csearch.rs
@@ -214,11 +214,11 @@ pub fn get_field_type(tcx: &ty::ctxt, class_id: ast::DefId,
     let cstore = &tcx.sess.cstore;
     let cdata = cstore.get_crate_data(class_id.krate);
     let all_items = reader::get_doc(reader::Doc(cdata.data()), tag_items);
-    let class_doc = expect(tcx.diag,
+    let class_doc = expect(tcx.sess.diagnostic(),
                            decoder::maybe_find_item(class_id.node, all_items),
                            || format!("get_field_type: class ID {:?} not found",
                                    class_id) );
-    let the_field = expect(tcx.diag,
+    let the_field = expect(tcx.sess.diagnostic(),
         decoder::maybe_find_item(def.node, class_doc),
         || format!("get_field_type: in class {:?}, field ID {:?} not found",
                  class_id, def) );
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index a1ee7d39ed7..b869e0a7d91 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -68,7 +68,7 @@ pub type EncodeInlinedItem<'a> = 'a |ecx: &EncodeContext,
                                      ii: InlinedItemRef|;
 
 pub struct EncodeParams<'a> {
-    diag: @SpanHandler,
+    diag: &'a SpanHandler,
     tcx: &'a ty::ctxt,
     reexports2: middle::resolve::ExportMap2,
     item_symbols: &'a RefCell<NodeMap<~str>>,
@@ -95,7 +95,7 @@ pub struct Stats {
 }
 
 pub struct EncodeContext<'a> {
-    diag: @SpanHandler,
+    diag: &'a SpanHandler,
     tcx: &'a ty::ctxt,
     stats: @Stats,
     reexports2: middle::resolve::ExportMap2,
@@ -904,7 +904,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
     }
 
     debug!("encoding info for item at {}",
-           ecx.tcx.sess.codemap.span_to_str(item.span));
+           ecx.tcx.sess.codemap().span_to_str(item.span));
 
     let def_id = local_def(item.id);
     match item.node {
@@ -1630,7 +1630,7 @@ impl<'a, 'b> Visitor<()> for MacroDefVisitor<'a, 'b> {
     fn visit_item(&mut self, item: &Item, _: ()) {
         match item.node {
             ItemMac(..) => {
-                let def = self.ecx.tcx.sess.codemap.span_to_snippet(item.span)
+                let def = self.ecx.tcx.sess.codemap().span_to_snippet(item.span)
                     .expect("Unable to find source for macro");
                 self.ebml_w.start_tag(tag_macro_def);
                 self.ebml_w.wr_str(def);
@@ -1901,7 +1901,7 @@ fn encode_metadata_inner(wr: &mut MemWriter, parms: EncodeParams, krate: &Crate)
 // Get the encoded string for a type
 pub fn encoded_ty(tcx: &ty::ctxt, t: ty::t) -> ~str {
     let cx = &tyencode::ctxt {
-        diag: tcx.diag,
+        diag: tcx.sess.diagnostic(),
         ds: def_to_str,
         tcx: tcx,
         abbrevs: tyencode::ac_no_abbrevs};
diff --git a/src/librustc/metadata/loader.rs b/src/librustc/metadata/loader.rs
index 5c4945a8140..28556105c7b 100644
--- a/src/librustc/metadata/loader.rs
+++ b/src/librustc/metadata/loader.rs
@@ -352,7 +352,7 @@ impl<'a> Context<'a> {
     }
 }
 
-pub fn note_crateid_attr(diag: @SpanHandler, crateid: &CrateId) {
+pub fn note_crateid_attr(diag: &SpanHandler, crateid: &CrateId) {
     diag.handler().note(format!("crate_id: {}", crateid.to_str()));
 }
 
diff --git a/src/librustc/metadata/tyencode.rs b/src/librustc/metadata/tyencode.rs
index 6366149c0f6..e78fe8e72a8 100644
--- a/src/librustc/metadata/tyencode.rs
+++ b/src/librustc/metadata/tyencode.rs
@@ -29,16 +29,15 @@ use syntax::ast;
 use syntax::ast::*;
 use syntax::diagnostic::SpanHandler;
 use syntax::parse::token;
-use syntax::print::pprust::*;
 
 macro_rules! mywrite( ($wr:expr, $($arg:tt)*) => (
     format_args!(|a| { mywrite($wr, a) }, $($arg)*)
 ) )
 
 pub struct ctxt<'a> {
-    diag: @SpanHandler,
+    diag: &'a SpanHandler,
     // Def -> str Callback:
-    ds: extern "Rust" fn(DefId) -> ~str,
+    ds: fn(DefId) -> ~str,
     // The type context.
     tcx: &'a ty::ctxt,
     abbrevs: abbrev_ctxt
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
index 69932a14795..2d4cbee243e 100644
--- a/src/librustc/middle/liveness.rs
+++ b/src/librustc/middle/liveness.rs
@@ -153,7 +153,7 @@ enum LiveNodeKind {
 }
 
 fn live_node_kind_to_str(lnk: LiveNodeKind, cx: &ty::ctxt) -> ~str {
-    let cm = cx.sess.codemap;
+    let cm = cx.sess.codemap();
     match lnk {
         FreeVarNode(s) => format!("Free var node [{}]", cm.span_to_str(s)),
         ExprNode(s)    => format!("Expr node [{}]", cm.span_to_str(s)),
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index a19b348b78a..a13dce65f51 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -847,7 +847,7 @@ fn resolve_fn(visitor: &mut RegionResolutionVisitor,
                                body.id={}, \
                                cx.parent={})",
            id,
-           visitor.sess.codemap.span_to_str(sp),
+           visitor.sess.codemap().span_to_str(sp),
            body.id,
            cx.parent);
 
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index bea776eb209..2784be5a01b 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -3275,7 +3275,7 @@ impl<'a> Resolver<'a> {
         let import_count = imports.get().len();
         if index != import_count {
             let sn = self.session
-                         .codemap
+                         .codemap()
                          .span_to_snippet(imports.get().get(index).span)
                          .unwrap();
             if sn.contains("::") {
@@ -5449,7 +5449,7 @@ impl<'a> Resolver<'a> {
     // public or private item, we will check the correct thing, dependent on how the import
     // is used.
     fn finalize_import(&mut self, id: NodeId, span: Span) {
-        debug!("finalizing import uses for {}", self.session.codemap.span_to_snippet(span));
+        debug!("finalizing import uses for {}", self.session.codemap().span_to_snippet(span));
 
         if !self.used_imports.contains(&(id, TypeNS)) &&
            !self.used_imports.contains(&(id, ValueNS)) {
diff --git a/src/librustc/middle/trans/builder.rs b/src/librustc/middle/trans/builder.rs
index bc99a0ac559..c403d323bf4 100644
--- a/src/librustc/middle/trans/builder.rs
+++ b/src/librustc/middle/trans/builder.rs
@@ -749,7 +749,7 @@ impl<'a> Builder<'a> {
 
     pub fn add_span_comment(&self, sp: Span, text: &str) {
         if self.ccx.sess().asm_comments() {
-            let s = format!("{} ({})", text, self.ccx.sess().codemap.span_to_str(sp));
+            let s = format!("{} ({})", text, self.ccx.sess().codemap().span_to_str(sp));
             debug!("{}", s);
             self.add_comment(s);
         }
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 43f7397f190..e812f36e85d 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -941,9 +941,9 @@ pub fn dummy_substs(tps: Vec<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 loc = bcx.sess().codemap().lookup_char_pos(span.lo);
     let filename_cstr = C_cstr(bcx.ccx(),
-                               token::intern_and_get_ident(loc.file.name));
+                               token::intern_and_get_ident(loc.file.deref().name));
     let filename = build::PointerCast(bcx, filename_cstr, Type::i8p(bcx.ccx()));
     let line = C_int(bcx.ccx(), loc.line as int);
     (filename, line)
diff --git a/src/librustc/middle/trans/context.rs b/src/librustc/middle/trans/context.rs
index b9c7cb93e12..4ed4f0fb310 100644
--- a/src/librustc/middle/trans/context.rs
+++ b/src/librustc/middle/trans/context.rs
@@ -132,13 +132,11 @@ impl CrateContext {
             let metadata_llmod = format!("{}_metadata", name).with_c_str(|buf| {
                 llvm::LLVMModuleCreateWithNameInContext(buf, llcx)
             });
-            let data_layout: &str = tcx.sess.targ_cfg.target_strs.data_layout;
-            let targ_triple: &str = tcx.sess.targ_cfg.target_strs.target_triple;
-            data_layout.with_c_str(|buf| {
+            tcx.sess.targ_cfg.target_strs.data_layout.with_c_str(|buf| {
                 llvm::LLVMSetDataLayout(llmod, buf);
                 llvm::LLVMSetDataLayout(metadata_llmod, buf);
             });
-            targ_triple.with_c_str(|buf| {
+            tcx.sess.targ_cfg.target_strs.target_triple.with_c_str(|buf| {
                 llvm::LLVMRustSetNormalizedTarget(llmod, buf);
                 llvm::LLVMRustSetNormalizedTarget(metadata_llmod, buf);
             });
diff --git a/src/librustc/middle/trans/controlflow.rs b/src/librustc/middle/trans/controlflow.rs
index 43e1e219e6f..2796eaeb129 100644
--- a/src/librustc/middle/trans/controlflow.rs
+++ b/src/librustc/middle/trans/controlflow.rs
@@ -331,13 +331,11 @@ pub fn trans_fail<'a>(
                   sp: Span,
                   fail_str: InternedString)
                   -> &'a Block<'a> {
-    let v_fail_str = C_cstr(bcx.ccx(), fail_str);
-    let _icx = push_ctxt("trans_fail_value");
     let ccx = bcx.ccx();
-    let sess = bcx.sess();
-    let loc = sess.parse_sess.cm.lookup_char_pos(sp.lo);
-    let v_filename = C_cstr(bcx.ccx(),
-                            token::intern_and_get_ident(loc.file.name));
+    let v_fail_str = C_cstr(ccx, fail_str);
+    let _icx = push_ctxt("trans_fail_value");
+    let loc = bcx.sess().codemap().lookup_char_pos(sp.lo);
+    let v_filename = C_cstr(ccx, token::intern_and_get_ident(loc.file.deref().name));
     let v_line = loc.line as int;
     let v_str = PointerCast(bcx, v_fail_str, Type::i8p(ccx));
     let v_filename = PointerCast(bcx, v_filename, Type::i8p(ccx));
diff --git a/src/librustc/middle/trans/debuginfo.rs b/src/librustc/middle/trans/debuginfo.rs
index 630512c8f69..b044ee15b3b 100644
--- a/src/librustc/middle/trans/debuginfo.rs
+++ b/src/librustc/middle/trans/debuginfo.rs
@@ -485,7 +485,7 @@ pub fn set_source_location(fcx: &FunctionContext,
 
     let cx = fcx.ccx;
 
-    debug!("set_source_location: {}", cx.sess().codemap.span_to_str(span));
+    debug!("set_source_location: {}", cx.sess().codemap().span_to_str(span));
 
     if fcx.debug_context.get_ref(cx, span).source_locations_enabled.get() {
         let loc = span_start(cx, span);
@@ -616,7 +616,7 @@ pub fn create_function_debug_context(cx: &CrateContext,
     }
 
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     let function_type_metadata = unsafe {
         let fn_signature = get_function_signature(cx, fn_ast_id, fn_decl, param_substs, span);
@@ -939,7 +939,7 @@ fn declare_local(bcx: &Block,
                  span: Span) {
     let cx: &CrateContext = bcx.ccx();
 
-    let filename = span_start(cx, span).file.name.clone();
+    let filename = span_start(cx, span).file.deref().name.clone();
     let file_metadata = file_metadata(cx, filename);
 
     let name = token::get_ident(variable_ident);
@@ -1195,7 +1195,7 @@ fn prepare_struct_metadata(cx: &CrateContext,
 
     let (containing_scope, definition_span) = get_namespace_and_span_for_item(cx, def_id);
 
-    let file_name = span_start(cx, definition_span).file.name.clone();
+    let file_name = span_start(cx, definition_span).file.deref().name.clone();
     let file_metadata = file_metadata(cx, file_name);
 
     let struct_metadata_stub = create_struct_stub(cx,
@@ -1292,7 +1292,7 @@ fn prepare_tuple_metadata(cx: &CrateContext,
     let tuple_llvm_type = type_of::type_of(cx, tuple_type);
 
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     UnfinishedMetadata {
         cache_id: cache_id_for_type(tuple_type),
@@ -1452,7 +1452,7 @@ fn prepare_enum_metadata(cx: &CrateContext,
 
     let (containing_scope, definition_span) = get_namespace_and_span_for_item(cx, enum_def_id);
     let loc = span_start(cx, definition_span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     // For empty enums there is an early exit. Just describe it as an empty struct with the
     // appropriate type name
@@ -1791,7 +1791,7 @@ fn boxed_type_metadata(cx: &CrateContext,
     ];
 
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     return composite_type_metadata(
         cx,
@@ -1892,16 +1892,16 @@ fn vec_metadata(cx: &CrateContext,
     assert!(member_descriptions.len() == member_llvm_types.len());
 
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
-    return composite_type_metadata(
+    composite_type_metadata(
         cx,
         vec_llvm_type,
         vec_type_name,
         member_descriptions,
         file_metadata,
         file_metadata,
-        span);
+        span)
 }
 
 fn vec_slice_metadata(cx: &CrateContext,
@@ -1943,7 +1943,7 @@ fn vec_slice_metadata(cx: &CrateContext,
     assert!(member_descriptions.len() == member_llvm_types.len());
 
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     return composite_type_metadata(
         cx,
@@ -1969,7 +1969,7 @@ fn subroutine_type_metadata(cx: &CrateContext,
                             span: Span)
                          -> DICompositeType {
     let loc = span_start(cx, span);
-    let file_metadata = file_metadata(cx, loc.file.name);
+    let file_metadata = file_metadata(cx, loc.file.deref().name);
 
     let mut signature_metadata: Vec<DIType> =
         Vec::with_capacity(signature.inputs.len() + 1);
@@ -2015,7 +2015,7 @@ fn trait_metadata(cx: &CrateContext,
 
     let (containing_scope, definition_span) = get_namespace_and_span_for_item(cx, def_id);
 
-    let file_name = span_start(cx, definition_span).file.name.clone();
+    let file_name = span_start(cx, definition_span).file.deref().name.clone();
     let file_metadata = file_metadata(cx, file_name);
 
     let trait_llvm_type = type_of::type_of(cx, trait_type);
@@ -2218,7 +2218,7 @@ fn generate_unique_type_id(prefix: &'static str) -> ~str {
 
 /// Return codemap::Loc corresponding to the beginning of the span
 fn span_start(cx: &CrateContext, span: Span) -> codemap::Loc {
-    cx.sess().codemap.lookup_char_pos(span.lo)
+    cx.sess().codemap().lookup_char_pos(span.lo)
 }
 
 fn size_and_align_of(cx: &CrateContext, llvm_type: Type) -> (u64, u64) {
@@ -2315,8 +2315,8 @@ fn populate_scope_map(cx: &CrateContext,
                                    &mut Vec<ScopeStackEntry> ,
                                    &mut HashMap<ast::NodeId, DIScope>|) {
         // Create a new lexical scope and push it onto the stack
-        let loc = cx.sess().codemap.lookup_char_pos(scope_span.lo);
-        let file_metadata = file_metadata(cx, loc.file.name);
+        let loc = cx.sess().codemap().lookup_char_pos(scope_span.lo);
+        let file_metadata = file_metadata(cx, loc.file.deref().name);
         let parent_scope = scope_stack.last().unwrap().scope_metadata;
 
         let scope_metadata = unsafe {
@@ -2432,8 +2432,8 @@ fn populate_scope_map(cx: &CrateContext,
 
                     if need_new_scope {
                         // Create a new lexical scope and push it onto the stack
-                        let loc = cx.sess().codemap.lookup_char_pos(pat.span.lo);
-                        let file_metadata = file_metadata(cx, loc.file.name);
+                        let loc = cx.sess().codemap().lookup_char_pos(pat.span.lo);
+                        let file_metadata = file_metadata(cx, loc.file.deref().name);
                         let parent_scope = scope_stack.last().unwrap().scope_metadata;
 
                         let scope_metadata = unsafe {
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index be74602c2f5..ae940ebeef2 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -253,7 +253,6 @@ pub enum AutoRef {
 /// generates so that so that it can be reused and doesn't have to be redone
 /// later on.
 pub struct ctxt {
-    diag: @syntax::diagnostic::SpanHandler,
     // Specifically use a speedy hash algorithm for this hash map, it's used
     // quite often.
     interner: RefCell<FnvHashMap<intern_key, ~t_box_>>,
@@ -1088,7 +1087,6 @@ pub fn mk_ctxt(s: Session,
     ctxt {
         named_region_map: named_region_map,
         item_variance_map: RefCell::new(DefIdMap::new()),
-        diag: s.diagnostic(),
         interner: RefCell::new(FnvHashMap::new()),
         next_id: Cell::new(primitives::LAST_PRIMITIVE_ID),
         sess: s,
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index b80fb2fa491..b3d3e59ea6b 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -139,9 +139,8 @@ pub fn explain_region_and_span(cx: &ctxt, region: ty::Region)
     };
 
     fn explain_span(cx: &ctxt, heading: &str, span: Span)
-        -> (~str, Option<Span>)
-    {
-        let lo = cx.sess.codemap.lookup_char_pos_adj(span.lo);
+        -> (~str, Option<Span>) {
+        let lo = cx.sess.codemap().lookup_char_pos_adj(span.lo);
         (format!("the {} at {}:{}", heading,
               lo.line, lo.col.to_uint()), Some(span))
     }
@@ -172,28 +171,28 @@ pub fn ReScope_id_to_str(cx: &ctxt, node_id: ast::NodeId) -> ~str {
     match cx.map.find(node_id) {
       Some(ast_map::NodeBlock(ref blk)) => {
         format!("<block at {}>",
-             cx.sess.codemap.span_to_str(blk.span))
+             cx.sess.codemap().span_to_str(blk.span))
       }
       Some(ast_map::NodeExpr(expr)) => {
         match expr.node {
           ast::ExprCall(..) => {
             format!("<call at {}>",
-                 cx.sess.codemap.span_to_str(expr.span))
+                 cx.sess.codemap().span_to_str(expr.span))
           }
           ast::ExprMatch(..) => {
             format!("<match at {}>",
-                 cx.sess.codemap.span_to_str(expr.span))
+                 cx.sess.codemap().span_to_str(expr.span))
           }
           ast::ExprAssignOp(..) |
           ast::ExprUnary(..) |
           ast::ExprBinary(..) |
           ast::ExprIndex(..) => {
             format!("<method at {}>",
-                 cx.sess.codemap.span_to_str(expr.span))
+                 cx.sess.codemap().span_to_str(expr.span))
           }
           _ => {
             format!("<expression at {}>",
-                 cx.sess.codemap.span_to_str(expr.span))
+                 cx.sess.codemap().span_to_str(expr.span))
           }
         }
       }
@@ -972,7 +971,7 @@ impl Repr for ty::BuiltinBounds {
 
 impl Repr for Span {
     fn repr(&self, tcx: &ctxt) -> ~str {
-        tcx.sess.codemap.span_to_str(*self)
+        tcx.sess.codemap().span_to_str(*self)
     }
 }
 
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index 7ff9a73f29d..65a0f473db2 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -375,7 +375,7 @@ pub fn find_stability<AM: AttrMetaMethods, It: Iterator<AM>>(mut metas: It)
     None
 }
 
-pub fn require_unique_names(diagnostic: @SpanHandler, metas: &[@MetaItem]) {
+pub fn require_unique_names(diagnostic: &SpanHandler, metas: &[@MetaItem]) {
     let mut set = HashSet::new();
     for meta in metas.iter() {
         let name = meta.name();
@@ -400,7 +400,7 @@ pub fn require_unique_names(diagnostic: @SpanHandler, metas: &[@MetaItem]) {
  * present (before fields, if any) with that type; reprensentation
  * optimizations which would remove it will not be done.
  */
-pub fn find_repr_attr(diagnostic: @SpanHandler, attr: @ast::MetaItem, acc: ReprAttr)
+pub fn find_repr_attr(diagnostic: &SpanHandler, attr: @ast::MetaItem, acc: ReprAttr)
     -> ReprAttr {
     let mut acc = acc;
     match attr.node {
@@ -438,7 +438,7 @@ pub fn find_repr_attr(diagnostic: @SpanHandler, attr: @ast::MetaItem, acc: ReprA
         // Not a "repr" hint: ignore.
         _ => { }
     }
-    return acc;
+    acc
 }
 
 fn int_type_of_word(s: &str) -> Option<IntType> {
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 5be03317b77..4bfd5391a8f 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -23,6 +23,7 @@ source code snippets, etc.
 
 use std::cell::RefCell;
 use std::cmp;
+use std::rc::Rc;
 use std::vec_ng::Vec;
 use serialize::{Encodable, Decodable, Encoder, Decoder};
 
@@ -140,7 +141,7 @@ pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
 /// A source code location used for error reporting
 pub struct Loc {
     /// Information about the original source
-    file: @FileMap,
+    file: Rc<FileMap>,
     /// The (1-based) line number
     line: uint,
     /// The (0-based) column offset
@@ -154,12 +155,12 @@ pub struct LocWithOpt {
     filename: FileName,
     line: uint,
     col: CharPos,
-    file: Option<@FileMap>,
+    file: Option<Rc<FileMap>>,
 }
 
 // used to be structural records. Better names, anyone?
-pub struct FileMapAndLine {fm: @FileMap, line: uint}
-pub struct FileMapAndBytePos {fm: @FileMap, pos: BytePos}
+pub struct FileMapAndLine {fm: Rc<FileMap>, line: uint}
+pub struct FileMapAndBytePos {fm: Rc<FileMap>, pos: BytePos}
 
 #[deriving(Clone, Hash, Show)]
 pub enum MacroFormat {
@@ -186,10 +187,10 @@ pub struct ExpnInfo {
 
 pub type FileName = ~str;
 
-pub struct FileLines
-{
-    file: @FileMap,
-    lines: Vec<uint> }
+pub struct FileLines {
+    file: Rc<FileMap>,
+    lines: Vec<uint>
+}
 
 /// Identifies an offset of a multi-byte character in a FileMap
 pub struct MultiByteChar {
@@ -251,8 +252,7 @@ impl FileMap {
             pos: pos,
             bytes: bytes,
         };
-        let mut multibyte_chars = self.multibyte_chars.borrow_mut();
-        multibyte_chars.get().push(mbc);
+        self.multibyte_chars.borrow_mut().get().push(mbc);
     }
 
     pub fn is_real_file(&self) -> bool {
@@ -261,7 +261,7 @@ impl FileMap {
 }
 
 pub struct CodeMap {
-    files: RefCell<Vec<@FileMap> >
+    files: RefCell<Vec<Rc<FileMap>>>
 }
 
 impl CodeMap {
@@ -271,11 +271,11 @@ impl CodeMap {
         }
     }
 
-    pub fn new_filemap(&self, filename: FileName, mut src: ~str) -> @FileMap {
+    pub fn new_filemap(&self, filename: FileName, mut src: ~str) -> Rc<FileMap> {
         let mut files = self.files.borrow_mut();
         let start_pos = match files.get().last() {
             None => 0,
-            Some(last) => last.start_pos.to_uint() + last.src.len(),
+            Some(last) => last.deref().start_pos.to_uint() + last.deref().src.len(),
         };
 
         // Append '\n' in case it's not already there.
@@ -286,34 +286,33 @@ impl CodeMap {
             src.push_char('\n');
         }
 
-        let filemap = @FileMap {
+        let filemap = Rc::new(FileMap {
             name: filename,
             src: src,
             start_pos: Pos::from_uint(start_pos),
             lines: RefCell::new(Vec::new()),
             multibyte_chars: RefCell::new(Vec::new()),
-        };
+        });
 
-        files.get().push(filemap);
+        files.get().push(filemap.clone());
 
-        return filemap;
+        filemap
     }
 
     pub fn mk_substr_filename(&self, sp: Span) -> ~str {
         let pos = self.lookup_char_pos(sp.lo);
-        return format!("<{}:{}:{}>", pos.file.name,
-                       pos.line, pos.col.to_uint() + 1)
+        format!("<{}:{}:{}>", pos.file.deref().name, pos.line, pos.col.to_uint() + 1)
     }
 
     /// Lookup source information about a BytePos
     pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
-        return self.lookup_pos(pos);
+        self.lookup_pos(pos)
     }
 
     pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
         let loc = self.lookup_char_pos(pos);
         LocWithOpt {
-            filename: loc.file.name.to_str(),
+            filename: loc.file.deref().name.to_str(),
             line: loc.line,
             col: loc.col,
             file: Some(loc.file)
@@ -321,11 +320,8 @@ impl CodeMap {
     }
 
     pub fn span_to_str(&self, sp: Span) -> ~str {
-        {
-            let files = self.files.borrow();
-            if files.get().len() == 0 && sp == DUMMY_SP {
-                return ~"no-location";
-            }
+        if self.files.borrow().get().len() == 0 && sp == DUMMY_SP {
+            return ~"no-location";
         }
 
         let lo = self.lookup_char_pos_adj(sp.lo);
@@ -335,18 +331,17 @@ impl CodeMap {
     }
 
     pub fn span_to_filename(&self, sp: Span) -> FileName {
-        let lo = self.lookup_char_pos(sp.lo);
-        lo.file.name.to_str()
+        self.lookup_char_pos(sp.lo).file.deref().name.to_str()
     }
 
-    pub fn span_to_lines(&self, sp: Span) -> @FileLines {
+    pub fn span_to_lines(&self, sp: Span) -> FileLines {
         let lo = self.lookup_char_pos(sp.lo);
         let hi = self.lookup_char_pos(sp.hi);
         let mut lines = Vec::new();
         for i in range(lo.line - 1u, hi.line as uint) {
             lines.push(i);
         };
-        return @FileLines {file: lo.file, lines: lines};
+        FileLines {file: lo.file, lines: lines}
     }
 
     pub fn span_to_snippet(&self, sp: Span) -> Option<~str> {
@@ -357,27 +352,22 @@ impl CodeMap {
         // it's testing isn't true for all spans in the AST, so to allow the
         // caller to not have to fail (and it can't catch it since the CodeMap
         // isn't sendable), return None
-        if begin.fm.start_pos != end.fm.start_pos {
+        if begin.fm.deref().start_pos != end.fm.deref().start_pos {
             None
         } else {
-            Some(begin.fm.src.slice( begin.pos.to_uint(), end.pos.to_uint()).to_owned())
+            Some(begin.fm.deref().src.slice( begin.pos.to_uint(), end.pos.to_uint()).to_owned())
         }
     }
 
-    pub fn get_filemap(&self, filename: &str) -> @FileMap {
-        let files = self.files.borrow();
-        for fm in files.get().iter() {
-            if filename == fm.name {
-                return *fm
+    pub fn get_filemap(&self, filename: &str) -> Rc<FileMap> {
+        for fm in self.files.borrow().get().iter() {
+            if filename == fm.deref().name {
+                return fm.clone();
             }
         }
-        //XXjdm the following triggers a mismatched type bug
-        //      (or expected function, found _|_)
-        fail!(); // ("asking for " + filename + " which we don't know about");
+        fail!("asking for {} which we don't know about", filename);
     }
-}
 
-impl CodeMap {
     fn lookup_filemap_idx(&self, pos: BytePos) -> uint {
         let files = self.files.borrow();
         let files = files.get();
@@ -386,7 +376,7 @@ impl CodeMap {
         let mut b = len;
         while b - a > 1u {
             let m = (a + b) / 2u;
-            if files.get(m).start_pos > pos {
+            if files.get(m).deref().start_pos > pos {
                 b = m;
             } else {
                 a = m;
@@ -396,7 +386,7 @@ impl CodeMap {
         // filemap, but are not the filemaps we want (because they are length 0, they cannot
         // contain what we are looking for). So, rewind until we find a useful filemap.
         loop {
-            let lines = files.get(a).lines.borrow();
+            let lines = files.get(a).deref().lines.borrow();
             let lines = lines.get();
             if lines.len() > 0 {
                 break;
@@ -413,28 +403,28 @@ impl CodeMap {
         return a;
     }
 
-    fn lookup_line(&self, pos: BytePos) -> FileMapAndLine
-    {
+    fn lookup_line(&self, pos: BytePos) -> FileMapAndLine {
         let idx = self.lookup_filemap_idx(pos);
 
         let files = self.files.borrow();
-        let f = *files.get().get(idx);
+        let f = files.get().get(idx).clone();
         let mut a = 0u;
-        let mut lines = f.lines.borrow_mut();
-        let mut b = lines.get().len();
-        while b - a > 1u {
-            let m = (a + b) / 2u;
-            if *lines.get().get(m) > pos { b = m; } else { a = m; }
+        {
+            let mut lines = f.deref().lines.borrow_mut();
+            let mut b = lines.get().len();
+            while b - a > 1u {
+                let m = (a + b) / 2u;
+                if *lines.get().get(m) > pos { b = m; } else { a = m; }
+            }
         }
-        return FileMapAndLine {fm: f, line: a};
+        FileMapAndLine {fm: f, line: a}
     }
 
     fn lookup_pos(&self, pos: BytePos) -> Loc {
         let FileMapAndLine {fm: f, line: a} = self.lookup_line(pos);
         let line = a + 1u; // Line numbers start at 1
         let chpos = self.bytepos_to_file_charpos(pos);
-        let lines = f.lines.borrow();
-        let linebpos = *lines.get().get(a);
+        let linebpos = *f.deref().lines.borrow().get().get(a);
         let linechpos = self.bytepos_to_file_charpos(linebpos);
         debug!("codemap: byte pos {:?} is on the line at byte pos {:?}",
                pos, linebpos);
@@ -442,20 +432,18 @@ impl CodeMap {
                chpos, linechpos);
         debug!("codemap: byte is on line: {:?}", line);
         assert!(chpos >= linechpos);
-        return Loc {
+        Loc {
             file: f,
             line: line,
             col: chpos - linechpos
-        };
+        }
     }
 
-    fn lookup_byte_offset(&self, bpos: BytePos)
-        -> FileMapAndBytePos {
+    fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
         let idx = self.lookup_filemap_idx(bpos);
-        let files = self.files.borrow();
-        let fm = *files.get().get(idx);
-        let offset = bpos - fm.start_pos;
-        return FileMapAndBytePos {fm: fm, pos: offset};
+        let fm = self.files.borrow().get().get(idx).clone();
+        let offset = bpos - fm.deref().start_pos;
+        FileMapAndBytePos {fm: fm, pos: offset}
     }
 
     // Converts an absolute BytePos to a CharPos relative to the filemap.
@@ -468,8 +456,7 @@ impl CodeMap {
         // The number of extra bytes due to multibyte chars in the FileMap
         let mut total_extra_bytes = 0;
 
-        let multibyte_chars = map.multibyte_chars.borrow();
-        for mbc in multibyte_chars.get().iter() {
+        for mbc in map.deref().multibyte_chars.borrow().get().iter() {
             debug!("codemap: {:?}-byte char at {:?}", mbc.bytes, mbc.pos);
             if mbc.pos < bpos {
                 // every character is at least one byte, so we only
@@ -483,8 +470,8 @@ impl CodeMap {
             }
         }
 
-        assert!(map.start_pos.to_uint() + total_extra_bytes <= bpos.to_uint());
-        CharPos(bpos.to_uint() - map.start_pos.to_uint() - total_extra_bytes)
+        assert!(map.deref().start_pos.to_uint() + total_extra_bytes <= bpos.to_uint());
+        CharPos(bpos.to_uint() - map.deref().start_pos.to_uint() - total_extra_bytes)
     }
 }
 
diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs
index 2da8b786805..c88c5a3c4e6 100644
--- a/src/libsyntax/diagnostic.rs
+++ b/src/libsyntax/diagnostic.rs
@@ -40,37 +40,37 @@ pub struct ExplicitBug;
 // accepts span information for source-location
 // reporting.
 pub struct SpanHandler {
-    handler: @Handler,
-    cm: @codemap::CodeMap,
+    handler: Handler,
+    cm: codemap::CodeMap,
 }
 
 impl SpanHandler {
     pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
-        self.handler.emit(Some((&*self.cm, sp)), msg, Fatal);
+        self.handler.emit(Some((&self.cm, sp)), msg, Fatal);
         fail!(FatalError);
     }
     pub fn span_err(&self, sp: Span, msg: &str) {
-        self.handler.emit(Some((&*self.cm, sp)), msg, Error);
+        self.handler.emit(Some((&self.cm, sp)), msg, Error);
         self.handler.bump_err_count();
     }
     pub fn span_warn(&self, sp: Span, msg: &str) {
-        self.handler.emit(Some((&*self.cm, sp)), msg, Warning);
+        self.handler.emit(Some((&self.cm, sp)), msg, Warning);
     }
     pub fn span_note(&self, sp: Span, msg: &str) {
-        self.handler.emit(Some((&*self.cm, sp)), msg, Note);
+        self.handler.emit(Some((&self.cm, sp)), msg, Note);
     }
     pub fn span_end_note(&self, sp: Span, msg: &str) {
-        self.handler.custom_emit(&*self.cm, sp, msg, Note);
+        self.handler.custom_emit(&self.cm, sp, msg, Note);
     }
     pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
-        self.handler.emit(Some((&*self.cm, sp)), msg, Bug);
+        self.handler.emit(Some((&self.cm, sp)), msg, Bug);
         fail!(ExplicitBug);
     }
     pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
         self.span_bug(sp, ~"unimplemented " + msg);
     }
-    pub fn handler(&self) -> @Handler {
-        self.handler
+    pub fn handler<'a>(&'a self) -> &'a Handler {
+        &self.handler
     }
 }
 
@@ -137,20 +137,19 @@ impl Handler {
     }
 }
 
-pub fn mk_span_handler(handler: @Handler, cm: @codemap::CodeMap)
-                       -> @SpanHandler {
-    @SpanHandler {
+pub fn mk_span_handler(handler: Handler, cm: codemap::CodeMap) -> SpanHandler {
+    SpanHandler {
         handler: handler,
         cm: cm,
     }
 }
 
-pub fn default_handler() -> @Handler {
+pub fn default_handler() -> Handler {
     mk_handler(~EmitterWriter::stderr())
 }
 
-pub fn mk_handler(e: ~Emitter) -> @Handler {
-    @Handler {
+pub fn mk_handler(e: ~Emitter) -> Handler {
+    Handler {
         err_count: Cell::new(0),
         emit: RefCell::new(e),
     }
@@ -301,8 +300,8 @@ fn highlight_lines(err: &mut EmitterWriter,
                    cm: &codemap::CodeMap,
                    sp: Span,
                    lvl: Level,
-                   lines: &codemap::FileLines) -> io::IoResult<()> {
-    let fm = lines.file;
+                   lines: codemap::FileLines) -> io::IoResult<()> {
+    let fm = lines.file.deref();
 
     let mut elided = false;
     let mut display_lines = lines.lines.as_slice();
@@ -374,8 +373,8 @@ fn custom_highlight_lines(w: &mut EmitterWriter,
                           cm: &codemap::CodeMap,
                           sp: Span,
                           lvl: Level,
-                          lines: &codemap::FileLines) -> io::IoResult<()> {
-    let fm = lines.file;
+                          lines: codemap::FileLines) -> io::IoResult<()> {
+    let fm = lines.file.deref();
 
     let lines = lines.lines.as_slice();
     if lines.len() > MAX_LINES {
@@ -420,8 +419,7 @@ fn print_macro_backtrace(w: &mut EmitterWriter,
     Ok(())
 }
 
-pub fn expect<T:Clone>(diag: @SpanHandler, opt: Option<T>, msg: || -> ~str)
-              -> T {
+pub fn expect<T:Clone>(diag: &SpanHandler, opt: Option<T>, msg: || -> ~str) -> T {
     match opt {
        Some(ref t) => (*t).clone(),
        None => diag.handler().bug(msg()),
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index a6f145a129e..df2c265e6eb 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -326,7 +326,7 @@ impl<'a> ExtCtxt<'a> {
         }
     }
 
-    pub fn codemap(&self) -> @CodeMap { self.parse_sess.cm }
+    pub fn codemap(&self) -> &'a CodeMap { &self.parse_sess.span_diagnostic.cm }
     pub fn parse_sess(&self) -> &'a parse::ParseSess { self.parse_sess }
     pub fn cfg(&self) -> ast::CrateConfig { self.cfg.clone() }
     pub fn call_site(&self) -> Span {
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 6aa90e5e842..7c42476bc01 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -633,7 +633,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             vec!(
                 self.expr_str(span, msg),
                 self.expr_str(span,
-                              token::intern_and_get_ident(loc.file.name)),
+                              token::intern_and_get_ident(loc.file.deref().name)),
                 self.expr_uint(span, loc.line)))
     }
 
diff --git a/src/libsyntax/ext/registrar.rs b/src/libsyntax/ext/registrar.rs
index 4c18eb83afc..d8bf726da79 100644
--- a/src/libsyntax/ext/registrar.rs
+++ b/src/libsyntax/ext/registrar.rs
@@ -37,7 +37,7 @@ impl Visitor<()> for MacroRegistrarContext {
     }
 }
 
-pub fn find_macro_registrar(diagnostic: @diagnostic::SpanHandler,
+pub fn find_macro_registrar(diagnostic: &diagnostic::SpanHandler,
                             krate: &ast::Crate) -> Option<ast::DefId> {
     let mut ctx = MacroRegistrarContext { registrars: Vec::new() };
     visit::walk_crate(&mut ctx, krate, ());
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index b31388f58eb..137cd89bf30 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -57,7 +57,7 @@ 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 = token::intern_and_get_ident(loc.file.name);
+    let filename = token::intern_and_get_ident(loc.file.deref().name);
     base::MRExpr(cx.expr_str(topmost.call_site, filename))
 }
 
@@ -117,7 +117,7 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             // dependency information
             let filename = file.display().to_str();
             let interned = token::intern_and_get_ident(src);
-            cx.parse_sess.cm.new_filemap(filename, src);
+            cx.codemap().new_filemap(filename, src);
 
             base::MRExpr(cx.expr_str(sp, interned))
         }
diff --git a/src/libsyntax/ext/trace_macros.rs b/src/libsyntax/ext/trace_macros.rs
index 183cccde18e..fa49f06e516 100644
--- a/src/libsyntax/ext/trace_macros.rs
+++ b/src/libsyntax/ext/trace_macros.rs
@@ -22,7 +22,7 @@ pub fn expand_trace_macros(cx: &mut ExtCtxt,
                         -> base::MacResult {
     let sess = cx.parse_sess();
     let cfg = cx.cfg();
-    let tt_rdr = new_tt_reader(cx.parse_sess().span_diagnostic,
+    let tt_rdr = new_tt_reader(&cx.parse_sess().span_diagnostic,
                                None,
                                tt.iter().map(|x| (*x).clone()).collect());
     let mut rust_parser = Parser(sess, cfg.clone(), tt_rdr.dup());
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 4cacbfd6e5a..3f4ed0b1e8e 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -131,13 +131,11 @@ fn generic_extension(cx: &ExtCtxt,
     let mut best_fail_spot = DUMMY_SP;
     let mut best_fail_msg = ~"internal error: ran no matchers";
 
-    let s_d = cx.parse_sess().span_diagnostic;
-
     for (i, lhs) in lhses.iter().enumerate() { // try each arm's matchers
         match **lhs {
           MatchedNonterminal(NtMatchers(ref mtcs)) => {
             // `None` is because we're not interpolating
-            let arg_rdr = new_tt_reader(s_d,
+            let arg_rdr = new_tt_reader(&cx.parse_sess().span_diagnostic,
                                         None,
                                         arg.iter()
                                            .map(|x| (*x).clone())
@@ -162,7 +160,8 @@ fn generic_extension(cx: &ExtCtxt,
                     _ => cx.span_bug(sp, "bad thing in rhs")
                 };
                 // rhs has holes ( `$id` and `$(...)` that need filled)
-                let trncbr = new_tt_reader(s_d, Some(named_matches),
+                let trncbr = new_tt_reader(&cx.parse_sess().span_diagnostic,
+                                           Some(named_matches),
                                            rhs);
                 let p = Parser(cx.parse_sess(), cx.cfg(), ~trncbr);
                 // Let the context choose how to interpret the result.
@@ -218,7 +217,7 @@ pub fn add_new_extension(cx: &mut ExtCtxt,
 
 
     // Parse the macro_rules! invocation (`none` is for no interpolations):
-    let arg_reader = new_tt_reader(cx.parse_sess().span_diagnostic,
+    let arg_reader = new_tt_reader(&cx.parse_sess().span_diagnostic,
                                    None,
                                    arg.clone());
     let argument_map = parse_or_else(cx.parse_sess(),
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index a3f179e851a..e120f07742e 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -30,8 +30,8 @@ struct TtFrame {
     up: Option<@TtFrame>,
 }
 
-pub struct TtReader {
-    sp_diag: @SpanHandler,
+pub struct TtReader<'a> {
+    sp_diag: &'a SpanHandler,
     // the unzipped tree:
     priv stack: RefCell<@TtFrame>,
     /* for MBE-style macro transcription */
@@ -46,10 +46,10 @@ pub struct TtReader {
 /** This can do Macro-By-Example transcription. On the other hand, if
  *  `src` contains no `TTSeq`s and `TTNonterminal`s, `interp` can (and
  *  should) be none. */
-pub fn new_tt_reader(sp_diag: @SpanHandler,
-                     interp: Option<HashMap<Ident, @NamedMatch>>,
-                     src: Vec<ast::TokenTree> )
-                     -> TtReader {
+pub fn new_tt_reader<'a>(sp_diag: &'a SpanHandler,
+                         interp: Option<HashMap<Ident, @NamedMatch>>,
+                         src: Vec<ast::TokenTree> )
+                         -> TtReader<'a> {
     let r = TtReader {
         sp_diag: sp_diag,
         stack: RefCell::new(@TtFrame {
@@ -70,7 +70,7 @@ pub fn new_tt_reader(sp_diag: @SpanHandler,
         cur_span: RefCell::new(DUMMY_SP),
     };
     tt_next_token(&r); /* get cur_tok and cur_span set up */
-    return r;
+    r
 }
 
 fn dup_tt_frame(f: @TtFrame) -> @TtFrame {
@@ -86,7 +86,7 @@ fn dup_tt_frame(f: @TtFrame) -> @TtFrame {
     }
 }
 
-pub fn dup_tt_reader(r: &TtReader) -> TtReader {
+pub fn dup_tt_reader<'a>(r: &TtReader<'a>) -> TtReader<'a> {
     TtReader {
         sp_diag: r.sp_diag,
         stack: RefCell::new(dup_tt_frame(r.stack.get())),
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index c2a2097de24..ed74fd416d1 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -346,10 +346,10 @@ pub struct Literal {
 // it appears this function is called only from pprust... that's
 // probably not a good thing.
 pub fn gather_comments_and_literals(span_diagnostic:
-                                        @diagnostic::SpanHandler,
+                                        &diagnostic::SpanHandler,
                                     path: ~str,
                                     srdr: &mut io::Reader)
-                                 -> (Vec<Comment> , Vec<Literal> ) {
+                                 -> (Vec<Comment>, Vec<Literal>) {
     let src = srdr.read_to_end().unwrap();
     let src = str::from_utf8_owned(src).unwrap();
     let cm = CodeMap::new();
diff --git a/src/libsyntax/parse/lexer.rs b/src/libsyntax/parse/lexer.rs
index 884fc306f22..43e1f8756fa 100644
--- a/src/libsyntax/parse/lexer.rs
+++ b/src/libsyntax/parse/lexer.rs
@@ -18,6 +18,7 @@ use parse::token::{str_to_ident};
 
 use std::cell::{Cell, RefCell};
 use std::char;
+use std::rc::Rc;
 use std::mem::replace;
 use std::num::from_str_radix;
 
@@ -27,7 +28,7 @@ pub trait Reader {
     fn is_eof(&self) -> bool;
     fn next_token(&self) -> TokenAndSpan;
     fn fatal(&self, ~str) -> !;
-    fn span_diag(&self) -> @SpanHandler;
+    fn span_diag<'a>(&'a self) -> &'a SpanHandler;
     fn peek(&self) -> TokenAndSpan;
     fn dup(&self) -> ~Reader:;
 }
@@ -38,8 +39,8 @@ pub struct TokenAndSpan {
     sp: Span,
 }
 
-pub struct StringReader {
-    span_diagnostic: @SpanHandler,
+pub struct StringReader<'a> {
+    span_diagnostic: &'a SpanHandler,
     // The absolute offset within the codemap of the next character to read
     pos: Cell<BytePos>,
     // The absolute offset within the codemap of the last character read(curr)
@@ -48,36 +49,36 @@ pub struct StringReader {
     col: Cell<CharPos>,
     // The last character to be read
     curr: Cell<Option<char>>,
-    filemap: @codemap::FileMap,
+    filemap: Rc<codemap::FileMap>,
     /* cached: */
     peek_tok: RefCell<token::Token>,
     peek_span: RefCell<Span>,
 }
 
-impl StringReader {
+impl<'a> StringReader<'a> {
     pub fn curr_is(&self, c: char) -> bool {
         self.curr.get() == Some(c)
     }
 }
 
-pub fn new_string_reader(span_diagnostic: @SpanHandler,
-                         filemap: @codemap::FileMap)
-                      -> StringReader {
+pub fn new_string_reader<'a>(span_diagnostic: &'a SpanHandler,
+                             filemap: Rc<codemap::FileMap>)
+                             -> StringReader<'a> {
     let r = new_low_level_string_reader(span_diagnostic, filemap);
     string_advance_token(&r); /* fill in peek_* */
     r
 }
 
 /* For comments.rs, which hackily pokes into 'pos' and 'curr' */
-pub fn new_low_level_string_reader(span_diagnostic: @SpanHandler,
-                                   filemap: @codemap::FileMap)
-                                -> StringReader {
+pub fn new_low_level_string_reader<'a>(span_diagnostic: &'a SpanHandler,
+                                       filemap: Rc<codemap::FileMap>)
+                                       -> StringReader<'a> {
     // Force the initial reader bump to start on a fresh line
     let initial_char = '\n';
     let r = StringReader {
         span_diagnostic: span_diagnostic,
-        pos: Cell::new(filemap.start_pos),
-        last_pos: Cell::new(filemap.start_pos),
+        pos: Cell::new(filemap.deref().start_pos),
+        last_pos: Cell::new(filemap.deref().start_pos),
         col: Cell::new(CharPos(0)),
         curr: Cell::new(Some(initial_char)),
         filemap: filemap,
@@ -92,20 +93,20 @@ pub fn new_low_level_string_reader(span_diagnostic: @SpanHandler,
 // duplicating the string reader is probably a bad idea, in
 // that using them will cause interleaved pushes of line
 // offsets to the underlying filemap...
-fn dup_string_reader(r: &StringReader) -> StringReader {
+fn dup_string_reader<'a>(r: &StringReader<'a>) -> StringReader<'a> {
     StringReader {
         span_diagnostic: r.span_diagnostic,
         pos: Cell::new(r.pos.get()),
         last_pos: Cell::new(r.last_pos.get()),
         col: Cell::new(r.col.get()),
         curr: Cell::new(r.curr.get()),
-        filemap: r.filemap,
+        filemap: r.filemap.clone(),
         peek_tok: r.peek_tok.clone(),
         peek_span: r.peek_span.clone(),
     }
 }
 
-impl Reader for StringReader {
+impl<'a> Reader for StringReader<'a> {
     fn is_eof(&self) -> bool { is_eof(self) }
     // return the next token. EFFECT: advances the string_reader.
     fn next_token(&self) -> TokenAndSpan {
@@ -122,7 +123,7 @@ impl Reader for StringReader {
     fn fatal(&self, m: ~str) -> ! {
         self.span_diagnostic.span_fatal(self.peek_span.get(), m)
     }
-    fn span_diag(&self) -> @SpanHandler { self.span_diagnostic }
+    fn span_diag<'a>(&'a self) -> &'a SpanHandler { self.span_diagnostic }
     fn peek(&self) -> TokenAndSpan {
         // FIXME(pcwalton): Bad copy!
         TokenAndSpan {
@@ -133,7 +134,7 @@ impl Reader for StringReader {
     fn dup(&self) -> ~Reader: { ~dup_string_reader(self) as ~Reader: }
 }
 
-impl Reader for TtReader {
+impl<'a> Reader for TtReader<'a> {
     fn is_eof(&self) -> bool {
         let cur_tok = self.cur_tok.borrow();
         *cur_tok.get() == token::EOF
@@ -146,7 +147,7 @@ impl Reader for TtReader {
     fn fatal(&self, m: ~str) -> ! {
         self.sp_diag.span_fatal(self.cur_span.get(), m);
     }
-    fn span_diag(&self) -> @SpanHandler { self.sp_diag }
+    fn span_diag<'a>(&'a self) -> &'a SpanHandler { self.sp_diag }
     fn peek(&self) -> TokenAndSpan {
         TokenAndSpan {
             tok: self.cur_tok.get(),
@@ -189,7 +190,7 @@ fn fatal_span_verbose(rdr: &StringReader,
                    -> ! {
     let mut m = m;
     m.push_str(": ");
-    let s = rdr.filemap.src.slice(
+    let s = rdr.filemap.deref().src.slice(
                   byte_offset(rdr, from_pos).to_uint(),
                   byte_offset(rdr, to_pos).to_uint());
     m.push_str(s);
@@ -218,7 +219,7 @@ fn string_advance_token(r: &StringReader) {
 }
 
 fn byte_offset(rdr: &StringReader, pos: BytePos) -> BytePos {
-    (pos - rdr.filemap.start_pos)
+    (pos - rdr.filemap.deref().start_pos)
 }
 
 /// Calls `f` with a string slice of the source text spanning from `start`
@@ -240,7 +241,7 @@ fn with_str_from_to<T>(
                     end: BytePos,
                     f: |s: &str| -> T)
                     -> T {
-    f(rdr.filemap.src.slice(
+    f(rdr.filemap.deref().src.slice(
             byte_offset(rdr, start).to_uint(),
             byte_offset(rdr, end).to_uint()))
 }
@@ -250,21 +251,21 @@ fn with_str_from_to<T>(
 pub fn bump(rdr: &StringReader) {
     rdr.last_pos.set(rdr.pos.get());
     let current_byte_offset = byte_offset(rdr, rdr.pos.get()).to_uint();
-    if current_byte_offset < (rdr.filemap.src).len() {
+    if current_byte_offset < rdr.filemap.deref().src.len() {
         assert!(rdr.curr.get().is_some());
         let last_char = rdr.curr.get().unwrap();
-        let next = rdr.filemap.src.char_range_at(current_byte_offset);
+        let next = rdr.filemap.deref().src.char_range_at(current_byte_offset);
         let byte_offset_diff = next.next - current_byte_offset;
         rdr.pos.set(rdr.pos.get() + Pos::from_uint(byte_offset_diff));
         rdr.curr.set(Some(next.ch));
         rdr.col.set(rdr.col.get() + CharPos(1u));
         if last_char == '\n' {
-            rdr.filemap.next_line(rdr.last_pos.get());
+            rdr.filemap.deref().next_line(rdr.last_pos.get());
             rdr.col.set(CharPos(0u));
         }
 
         if byte_offset_diff > 1 {
-            rdr.filemap.record_multibyte_char(rdr.last_pos.get(), byte_offset_diff);
+            rdr.filemap.deref().record_multibyte_char(rdr.last_pos.get(), byte_offset_diff);
         }
     } else {
         rdr.curr.set(None);
@@ -275,8 +276,8 @@ pub fn is_eof(rdr: &StringReader) -> bool {
 }
 pub fn nextch(rdr: &StringReader) -> Option<char> {
     let offset = byte_offset(rdr, rdr.pos.get()).to_uint();
-    if offset < (rdr.filemap.src).len() {
-        Some(rdr.filemap.src.char_at(offset))
+    if offset < rdr.filemap.deref().src.len() {
+        Some(rdr.filemap.deref().src.char_at(offset))
     } else {
         None
     }
@@ -334,56 +335,55 @@ fn consume_any_line_comment(rdr: &StringReader)
                          -> Option<TokenAndSpan> {
     if rdr.curr_is('/') {
         match nextch(rdr) {
-          Some('/') => {
-            bump(rdr);
-            bump(rdr);
-            // line comments starting with "///" or "//!" are doc-comments
-            if rdr.curr_is('/') || rdr.curr_is('!') {
-                let start_bpos = rdr.pos.get() - BytePos(3);
-                while !rdr.curr_is('\n') && !is_eof(rdr) {
-                    bump(rdr);
-                }
-                let ret = with_str_from(rdr, start_bpos, |string| {
-                    // but comments with only more "/"s are not
-                    if !is_line_non_doc_comment(string) {
-                        Some(TokenAndSpan{
-                            tok: token::DOC_COMMENT(str_to_ident(string)),
-                            sp: codemap::mk_sp(start_bpos, rdr.pos.get())
-                        })
-                    } else {
-                        None
+            Some('/') => {
+                bump(rdr);
+                bump(rdr);
+                // line comments starting with "///" or "//!" are doc-comments
+                if rdr.curr_is('/') || rdr.curr_is('!') {
+                    let start_bpos = rdr.pos.get() - BytePos(3);
+                    while !rdr.curr_is('\n') && !is_eof(rdr) {
+                        bump(rdr);
                     }
-                });
+                    let ret = with_str_from(rdr, start_bpos, |string| {
+                        // but comments with only more "/"s are not
+                        if !is_line_non_doc_comment(string) {
+                            Some(TokenAndSpan{
+                                tok: token::DOC_COMMENT(str_to_ident(string)),
+                                sp: codemap::mk_sp(start_bpos, rdr.pos.get())
+                            })
+                        } else {
+                            None
+                        }
+                    });
 
-                if ret.is_some() {
-                    return ret;
+                    if ret.is_some() {
+                        return ret;
+                    }
+                } else {
+                    while !rdr.curr_is('\n') && !is_eof(rdr) { bump(rdr); }
                 }
-            } else {
-                while !rdr.curr_is('\n') && !is_eof(rdr) { bump(rdr); }
+                // Restart whitespace munch.
+                consume_whitespace_and_comments(rdr)
             }
-            // Restart whitespace munch.
-            return consume_whitespace_and_comments(rdr);
-          }
-          Some('*') => { bump(rdr); bump(rdr); return consume_block_comment(rdr); }
-          _ => ()
+            Some('*') => { bump(rdr); bump(rdr); consume_block_comment(rdr) }
+            _ => None
         }
     } else if rdr.curr_is('#') {
         if nextch_is(rdr, '!') {
             // I guess this is the only way to figure out if
             // we're at the beginning of the file...
-            let cmap = @CodeMap::new();
-            {
-                let mut files = cmap.files.borrow_mut();
-                files.get().push(rdr.filemap);
-            }
+            let cmap = CodeMap::new();
+            cmap.files.borrow_mut().get().push(rdr.filemap.clone());
             let loc = cmap.lookup_char_pos_adj(rdr.last_pos.get());
             if loc.line == 1u && loc.col == CharPos(0u) {
                 while !rdr.curr_is('\n') && !is_eof(rdr) { bump(rdr); }
                 return consume_whitespace_and_comments(rdr);
             }
         }
+        None
+    } else {
+        None
     }
-    return None;
 }
 
 pub fn is_block_non_doc_comment(s: &str) -> bool {
@@ -1019,7 +1019,7 @@ mod test {
         let writer = ~util::NullWriter;
         let emitter = diagnostic::EmitterWriter::new(writer);
         let handler = diagnostic::mk_handler(~emitter);
-        let span_handler = diagnostic::mk_span_handler(handler, @cm);
+        let span_handler = diagnostic::mk_span_handler(handler, cm);
         Env {
             string_reader: new_string_reader(span_handler,fm)
         }
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 19291f72101..79fedf82798 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -13,13 +13,13 @@
 
 use ast;
 use codemap::{Span, CodeMap, FileMap};
-use codemap;
 use diagnostic::{SpanHandler, mk_span_handler, default_handler};
 use parse::attr::ParserAttr;
 use parse::parser::Parser;
 
 use std::cell::RefCell;
 use std::io::File;
+use std::rc::Rc;
 use std::str;
 use std::vec_ng::Vec;
 
@@ -40,26 +40,20 @@ pub mod obsolete;
 
 // info about a parsing session.
 pub struct ParseSess {
-    cm: @codemap::CodeMap, // better be the same as the one in the reader!
-    span_diagnostic: @SpanHandler, // better be the same as the one in the reader!
+    span_diagnostic: SpanHandler, // better be the same as the one in the reader!
     /// Used to determine and report recursive mod inclusions
-    included_mod_stack: RefCell<Vec<Path> >,
+    included_mod_stack: RefCell<Vec<Path>>,
 }
 
 pub fn new_parse_sess() -> ParseSess {
-    let cm = @CodeMap::new();
     ParseSess {
-        cm: cm,
-        span_diagnostic: mk_span_handler(default_handler(), cm),
+        span_diagnostic: mk_span_handler(default_handler(), CodeMap::new()),
         included_mod_stack: RefCell::new(Vec::new()),
     }
 }
 
-pub fn new_parse_sess_special_handler(sh: @SpanHandler,
-                                      cm: @codemap::CodeMap)
-                                      -> ParseSess {
+pub fn new_parse_sess_special_handler(sh: SpanHandler) -> ParseSess {
     ParseSess {
-        cm: cm,
         span_diagnostic: sh,
         included_mod_stack: RefCell::new(Vec::new()),
     }
@@ -175,40 +169,36 @@ pub fn parse_tts_from_source_str(name: ~str,
 
 // Create a new parser from a source string
 pub fn new_parser_from_source_str<'a>(sess: &'a ParseSess,
-                                     cfg: ast::CrateConfig,
-                                     name: ~str,
-                                     source: ~str)
-                                     -> Parser<'a> {
-    filemap_to_parser(sess,string_to_filemap(sess,source,name),cfg)
+                                      cfg: ast::CrateConfig,
+                                      name: ~str,
+                                      source: ~str)
+                                      -> Parser<'a> {
+    filemap_to_parser(sess, string_to_filemap(sess, source, name), cfg)
 }
 
 /// Create a new parser, handling errors as appropriate
 /// if the file doesn't exist
-pub fn new_parser_from_file<'a>(
-    sess: &'a ParseSess,
-    cfg: ast::CrateConfig,
-    path: &Path
-) -> Parser<'a> {
-    filemap_to_parser(sess,file_to_filemap(sess,path,None),cfg)
+pub fn new_parser_from_file<'a>(sess: &'a ParseSess,
+                                cfg: ast::CrateConfig,
+                                path: &Path) -> Parser<'a> {
+    filemap_to_parser(sess, file_to_filemap(sess, path, None), cfg)
 }
 
 /// Given a session, a crate config, a path, and a span, add
 /// the file at the given path to the codemap, and return a parser.
 /// On an error, use the given span as the source of the problem.
-pub fn new_sub_parser_from_file<'a>(
-    sess: &'a ParseSess,
-    cfg: ast::CrateConfig,
-    path: &Path,
-    sp: Span
-) -> Parser<'a> {
-    filemap_to_parser(sess,file_to_filemap(sess,path,Some(sp)),cfg)
+pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
+                                    cfg: ast::CrateConfig,
+                                    path: &Path,
+                                    sp: Span) -> Parser<'a> {
+    filemap_to_parser(sess, file_to_filemap(sess, path, Some(sp)), cfg)
 }
 
 /// Given a filemap and config, return a parser
 pub fn filemap_to_parser<'a>(sess: &'a ParseSess,
-                             filemap: @FileMap,
+                             filemap: Rc<FileMap>,
                              cfg: ast::CrateConfig) -> Parser<'a> {
-    tts_to_parser(sess,filemap_to_tts(sess,filemap),cfg)
+    tts_to_parser(sess, filemap_to_tts(sess, filemap), cfg)
 }
 
 // must preserve old name for now, because quote! from the *existing*
@@ -216,7 +206,7 @@ pub fn filemap_to_parser<'a>(sess: &'a ParseSess,
 pub fn new_parser_from_tts<'a>(sess: &'a ParseSess,
                                cfg: ast::CrateConfig,
                                tts: Vec<ast::TokenTree>) -> Parser<'a> {
-    tts_to_parser(sess,tts,cfg)
+    tts_to_parser(sess, tts, cfg)
 }
 
 
@@ -225,7 +215,7 @@ pub fn new_parser_from_tts<'a>(sess: &'a ParseSess,
 /// Given a session and a path and an optional span (for error reporting),
 /// add the path to the session's codemap and return the new filemap.
 pub fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
-    -> @FileMap {
+    -> Rc<FileMap> {
     let err = |msg: &str| {
         match spanopt {
             Some(sp) => sess.span_diagnostic.span_fatal(sp, msg),
@@ -251,17 +241,17 @@ pub fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
 // given a session and a string, add the string to
 // the session's codemap and return the new filemap
 pub fn string_to_filemap(sess: &ParseSess, source: ~str, path: ~str)
-                         -> @FileMap {
-    sess.cm.new_filemap(path, source)
+                         -> Rc<FileMap> {
+    sess.span_diagnostic.cm.new_filemap(path, source)
 }
 
 // given a filemap, produce a sequence of token-trees
-pub fn filemap_to_tts(sess: &ParseSess, filemap: @FileMap)
+pub fn filemap_to_tts(sess: &ParseSess, filemap: Rc<FileMap>)
     -> Vec<ast::TokenTree> {
     // it appears to me that the cfg doesn't matter here... indeed,
     // parsing tt's probably shouldn't require a parser at all.
     let cfg = Vec::new();
-    let srdr = lexer::new_string_reader(sess.span_diagnostic, filemap);
+    let srdr = lexer::new_string_reader(&sess.span_diagnostic, filemap);
     let mut p1 = Parser(sess, cfg, ~srdr);
     p1.parse_all_token_trees()
 }
@@ -270,7 +260,7 @@ pub fn filemap_to_tts(sess: &ParseSess, filemap: @FileMap)
 pub fn tts_to_parser<'a>(sess: &'a ParseSess,
                          tts: Vec<ast::TokenTree>,
                          cfg: ast::CrateConfig) -> Parser<'a> {
-    let trdr = lexer::new_tt_reader(sess.span_diagnostic, None, tts);
+    let trdr = lexer::new_tt_reader(&sess.span_diagnostic, None, tts);
     Parser(sess, cfg, ~trdr)
 }
 
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index d183eb44cc2..27c86956499 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4150,7 +4150,7 @@ impl<'a> Parser<'a> {
                     outer_attrs: &[ast::Attribute],
                     id_sp: Span)
                     -> (ast::Item_, Vec<ast::Attribute> ) {
-        let mut prefix = Path::new(self.sess.cm.span_to_filename(self.span));
+        let mut prefix = Path::new(self.sess.span_diagnostic.cm.span_to_filename(self.span));
         prefix.pop();
         let mod_path = Path::new(".").join_many(self.mod_path_stack.as_slice());
         let dir_path = prefix.join(&mod_path);