Rename middle::metadata to metadata::cwriter. Move creader to metadata

Preparation for a lot more metadata refactoring

5 files changed, 9 insertions, 825 deletions

diff --git a/src/comp/middle/metadata.rs b/src/comp/middle/metadata.rs
deleted file mode 100644
index fcaaba2e499..00000000000
--- a/src/comp/middle/metadata.rs
+++ /dev/null
@@ -1,817 +0,0 @@
-
-import std::str;
-import std::uint;
-import std::vec;
-import std::map::hashmap;
-import std::ebml;
-import std::io;
-import std::option;
-import std::option::some;
-import std::option::none;
-import front::ast::*;
-import middle::trans;
-import middle::ty;
-import middle::ty::path_to_str;
-import back::x86;
-import back::link;
-import util::common;
-import pretty::ppaux::lit_to_str;
-import lib::llvm::llvm;
-import lib::llvm::llvm::ValueRef;
-import lib::llvm::False;
-
-export ac_no_abbrevs;
-export def_to_str;
-export encode;
-export hash_def_id;
-export hash_path;
-export tag_def_id;
-export tag_index;
-export tag_index_table;
-export tag_index_buckets;
-export tag_index_buckets_bucket;
-export tag_index_buckets_bucket_elt;
-export tag_items;
-export tag_items_data_item_kind;
-export tag_items_data_item_symbol;
-export tag_items_data_item_tag_id;
-export tag_items_data_item_type;
-export tag_items_data_item_ty_param_count;
-export tag_items_data_item_variant;
-export tag_meta_export;
-export tag_meta_item;
-export tag_meta_item_key;
-export tag_meta_item_value;
-export tag_paths;
-export ty_abbrev;
-export write_metadata;
-
-const uint tag_paths = 0x01u;
-
-const uint tag_items = 0x02u;
-
-const uint tag_paths_data = 0x03u;
-
-const uint tag_paths_data_name = 0x04u;
-
-const uint tag_paths_data_item = 0x05u;
-
-const uint tag_paths_data_mod = 0x06u;
-
-const uint tag_def_id = 0x07u;
-
-const uint tag_items_data = 0x08u;
-
-const uint tag_items_data_item = 0x09u;
-
-const uint tag_items_data_item_kind = 0x0au;
-
-const uint tag_items_data_item_ty_param_count = 0x0bu;
-
-const uint tag_items_data_item_type = 0x0cu;
-
-const uint tag_items_data_item_symbol = 0x0du;
-
-const uint tag_items_data_item_variant = 0x0eu;
-
-const uint tag_items_data_item_tag_id = 0x0fu;
-
-const uint tag_index = 0x11u;
-
-const uint tag_index_buckets = 0x12u;
-
-const uint tag_index_buckets_bucket = 0x13u;
-
-const uint tag_index_buckets_bucket_elt = 0x14u;
-
-const uint tag_index_table = 0x15u;
-
-const uint tag_meta_export = 0x16u;
-
-const uint tag_meta_local = 0x17u;
-
-const uint tag_meta_item = 0x18u;
-
-const uint tag_meta_item_key = 0x19u;
-
-const uint tag_meta_item_value = 0x20u;
-
-
-// Type encoding
-
-// Compact string representation for ty.t values. API ty_str & parse_from_str.
-// Extra parameters are for converting to/from def_ids in the string rep.
-// Whatever format you choose should not contain pipe characters.
-type ty_abbrev = rec(uint pos, uint len, str s);
-
-tag abbrev_ctxt { ac_no_abbrevs; ac_use_abbrevs(hashmap[ty::t, ty_abbrev]); }
-
-mod encode {
-    type ctxt =
-        rec(fn(&def_id) -> str  ds, // Def -> str Callback:
-
-            ty::ctxt tcx, // The type context.
-
-            abbrev_ctxt abbrevs);
-
-    fn cx_uses_abbrevs(&@ctxt cx) -> bool {
-        alt (cx.abbrevs) {
-            case (ac_no_abbrevs) { ret false; }
-            case (ac_use_abbrevs(_)) { ret true; }
-        }
-    }
-    fn ty_str(&@ctxt cx, &ty::t t) -> str {
-        assert (!cx_uses_abbrevs(cx));
-        auto sw = io::string_writer();
-        enc_ty(sw.get_writer(), cx, t);
-        ret sw.get_str();
-    }
-    fn enc_ty(&io::writer w, &@ctxt cx, &ty::t t) {
-        alt (cx.abbrevs) {
-            case (ac_no_abbrevs) {
-                auto result_str;
-                alt (cx.tcx.short_names_cache.find(t)) {
-                    case (some(?s)) { result_str = s; }
-                    case (none) {
-                        auto sw = io::string_writer();
-                        enc_sty(sw.get_writer(), cx, ty::struct(cx.tcx, t));
-                        result_str = sw.get_str();
-                        cx.tcx.short_names_cache.insert(t, result_str);
-                    }
-                }
-                w.write_str(result_str);
-            }
-            case (ac_use_abbrevs(?abbrevs)) {
-                alt (abbrevs.find(t)) {
-                    case (some(?a)) { w.write_str(a.s); ret; }
-                    case (none) {
-                        auto pos = w.get_buf_writer().tell();
-                        auto ss = enc_sty(w, cx, ty::struct(cx.tcx, t));
-                        auto end = w.get_buf_writer().tell();
-                        auto len = end - pos;
-                        fn estimate_sz(uint u) -> uint {
-                            auto n = u;
-                            auto len = 0u;
-                            while (n != 0u) { len += 1u; n = n >> 4u; }
-                            ret len;
-                        }
-                        auto abbrev_len =
-                            3u + estimate_sz(pos) + estimate_sz(len);
-                        if (abbrev_len < len) {
-                            // I.e. it's actually an abbreviation.
-
-                            auto s =
-                                "#" + uint::to_str(pos, 16u) + ":" +
-                                    uint::to_str(len, 16u) + "#";
-                            auto a = rec(pos=pos, len=len, s=s);
-                            abbrevs.insert(t, a);
-                        }
-                        ret;
-                    }
-                }
-            }
-        }
-    }
-    fn enc_mt(&io::writer w, &@ctxt cx, &ty::mt mt) {
-        alt (mt.mut) {
-            case (imm) { }
-            case (mut) { w.write_char('m'); }
-            case (maybe_mut) { w.write_char('?'); }
-        }
-        enc_ty(w, cx, mt.ty);
-    }
-    fn enc_sty(&io::writer w, &@ctxt cx, &ty::sty st) {
-        alt (st) {
-            case (ty::ty_nil) { w.write_char('n'); }
-            case (ty::ty_bot) { w.write_char('z'); }
-            case (ty::ty_bool) { w.write_char('b'); }
-            case (ty::ty_int) { w.write_char('i'); }
-            case (ty::ty_uint) { w.write_char('u'); }
-            case (ty::ty_float) { w.write_char('l'); }
-            case (ty::ty_machine(?mach)) {
-                alt (mach) {
-                    case (common::ty_u8) { w.write_str("Mb"); }
-                    case (common::ty_u16) { w.write_str("Mw"); }
-                    case (common::ty_u32) { w.write_str("Ml"); }
-                    case (common::ty_u64) { w.write_str("Md"); }
-                    case (common::ty_i8) { w.write_str("MB"); }
-                    case (common::ty_i16) { w.write_str("MW"); }
-                    case (common::ty_i32) { w.write_str("ML"); }
-                    case (common::ty_i64) { w.write_str("MD"); }
-                    case (common::ty_f32) { w.write_str("Mf"); }
-                    case (common::ty_f64) { w.write_str("MF"); }
-                }
-            }
-            case (ty::ty_char) { w.write_char('c'); }
-            case (ty::ty_str) { w.write_char('s'); }
-            case (ty::ty_istr) { w.write_char('S'); }
-            case (ty::ty_tag(?def, ?tys)) {
-                w.write_str("t[");
-                w.write_str(cx.ds(def));
-                w.write_char('|');
-                for (ty::t t in tys) { enc_ty(w, cx, t); }
-                w.write_char(']');
-            }
-            case (ty::ty_box(?mt)) { w.write_char('@'); enc_mt(w, cx, mt); }
-            case (ty::ty_ptr(?mt)) { w.write_char('*'); enc_mt(w, cx, mt); }
-            case (ty::ty_vec(?mt)) { w.write_char('V'); enc_mt(w, cx, mt); }
-            case (ty::ty_ivec(?mt)) { w.write_char('I'); enc_mt(w, cx, mt); }
-            case (ty::ty_port(?t)) { w.write_char('P'); enc_ty(w, cx, t); }
-            case (ty::ty_chan(?t)) { w.write_char('C'); enc_ty(w, cx, t); }
-            case (ty::ty_tup(?mts)) {
-                w.write_str("T[");
-                for (ty::mt mt in mts) { enc_mt(w, cx, mt); }
-                w.write_char(']');
-            }
-            case (ty::ty_rec(?fields)) {
-                w.write_str("R[");
-                for (ty::field field in fields) {
-                    w.write_str(field.ident);
-                    w.write_char('=');
-                    enc_mt(w, cx, field.mt);
-                }
-                w.write_char(']');
-            }
-            case (ty::ty_fn(?proto, ?args, ?out, ?cf, ?constrs)) {
-                enc_proto(w, proto);
-                enc_ty_fn(w, cx, args, out, cf, constrs);
-            }
-            case (ty::ty_native_fn(?abi, ?args, ?out)) {
-                w.write_char('N');
-                alt (abi) {
-                    case (native_abi_rust) { w.write_char('r'); }
-                    case (native_abi_rust_intrinsic) {
-                        w.write_char('i');
-                    }
-                    case (native_abi_cdecl) { w.write_char('c'); }
-                    case (native_abi_llvm) { w.write_char('l'); }
-                }
-                enc_ty_fn(w, cx, args, out, return, []);
-            }
-            case (ty::ty_obj(?methods)) {
-                w.write_str("O[");
-                for (ty::method m in methods) {
-                    enc_proto(w, m.proto);
-                    w.write_str(m.ident);
-                    enc_ty_fn(w, cx, m.inputs, m.output, m.cf, m.constrs);
-                }
-                w.write_char(']');
-            }
-            case (ty::ty_res(?def, ?ty)) {
-                w.write_char('r');
-                w.write_str(cx.ds(def));
-                w.write_char('|');
-                enc_ty(w, cx, ty);
-            }
-            case (ty::ty_var(?id)) {
-                w.write_char('X');
-                w.write_str(common::istr(id));
-            }
-            case (ty::ty_native) { w.write_char('E'); }
-            case (ty::ty_param(?id)) {
-                w.write_char('p');
-                w.write_str(common::uistr(id));
-            }
-            case (ty::ty_type) { w.write_char('Y'); }
-            case (ty::ty_task) { w.write_char('a'); }
-        }
-    }
-    fn enc_proto(&io::writer w, proto proto) {
-        alt (proto) {
-            case (proto_iter) { w.write_char('W'); }
-            case (proto_fn) { w.write_char('F'); }
-        }
-    }
-    fn enc_ty_fn(&io::writer w, &@ctxt cx, &vec[ty::arg] args, &ty::t out,
-                 &controlflow cf, &vec[@ty::constr_def] constrs) {
-        w.write_char('[');
-        for (ty::arg arg in args) {
-            alt (arg.mode) {
-                case (ty::mo_alias(?mut)) {
-                    w.write_char('&');
-                    if (mut) { w.write_char('m'); }
-                }
-                case (ty::mo_val) { }
-            }
-            enc_ty(w, cx, arg.ty);
-        }
-        w.write_char(']');
-        auto colon = true;
-        for (@ty::constr_def c in constrs) {
-            if (colon) {
-                w.write_char(':');
-                colon = false;
-            } else { w.write_char(';'); }
-            enc_constr(w, cx, c);
-        }
-        alt (cf) {
-            case (noreturn) { w.write_char('!'); }
-            case (_) { enc_ty(w, cx, out); }
-        }
-
-    }
-    fn enc_constr(&io::writer w, &@ctxt cx, &@ty::constr_def c) {
-        w.write_str(path_to_str(c.node.path));
-        w.write_char('(');
-        w.write_str(cx.ds(c.node.id));
-        w.write_char('|');
-        auto semi = false;
-        for (@constr_arg a in c.node.args) {
-            if (semi) { w.write_char(';'); } else { semi = true; }
-            alt (a.node) {
-                case (carg_base) { w.write_char('*'); }
-                case (carg_ident(?i)) { 
-                    w.write_uint(i);
-                }
-                case (carg_lit(?l)) { w.write_str(lit_to_str(l)); }
-            }
-        }
-        w.write_char(')');
-    }
-}
-
-
-// Returns a Plain Old LLVM String:
-fn C_postr(&str s) -> ValueRef {
-    ret llvm::LLVMConstString(str::buf(s), str::byte_len(s), False);
-}
-
-
-// Path table encoding
-fn encode_name(&ebml::writer ebml_w, &str name) {
-    ebml::start_tag(ebml_w, tag_paths_data_name);
-    ebml_w.writer.write(str::bytes(name));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_def_id(&ebml::writer ebml_w, &def_id id) {
-    ebml::start_tag(ebml_w, tag_def_id);
-    ebml_w.writer.write(str::bytes(def_to_str(id)));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_tag_variant_paths(&ebml::writer ebml_w, &vec[variant] variants,
-                            &vec[str] path,
-                            &mutable vec[tup(str, uint)] index) {
-    for (variant variant in variants) {
-        add_to_index(ebml_w, path, index, variant.node.name);
-        ebml::start_tag(ebml_w, tag_paths_data_item);
-        encode_name(ebml_w, variant.node.name);
-        encode_def_id(ebml_w, local_def(variant.node.id));
-        ebml::end_tag(ebml_w);
-    }
-}
-
-fn add_to_index(&ebml::writer ebml_w, &vec[str] path,
-                &mutable vec[tup(str, uint)] index, &str name) {
-    auto full_path = path + [name];
-    index += [tup(str::connect(full_path, "::"), ebml_w.writer.tell())];
-}
-
-fn encode_native_module_item_paths(&ebml::writer ebml_w,
-                                   &native_mod nmod, &vec[str] path,
-                                   &mutable vec[tup(str, uint)] index) {
-    for (@native_item nitem in nmod.items) {
-        add_to_index(ebml_w, path, index, nitem.ident);
-        ebml::start_tag(ebml_w, tag_paths_data_item);
-        encode_name(ebml_w, nitem.ident);
-        encode_def_id(ebml_w, local_def(nitem.id));
-        ebml::end_tag(ebml_w);
-    }
-}
-
-fn encode_module_item_paths(&ebml::writer ebml_w, &_mod module,
-                            &vec[str] path,
-                            &mutable vec[tup(str, uint)] index) {
-    for (@item it in module.items) {
-        if (!is_exported(it.ident, module)) { cont; }
-        alt (it.node) {
-            case (item_const(_, _)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-            }
-            case (item_fn(_, ?tps)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-            }
-            case (item_mod(?_mod)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_mod);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                encode_module_item_paths(ebml_w, _mod, path + [it.ident],
-                                         index);
-                ebml::end_tag(ebml_w);
-            }
-            case (item_native_mod(?nmod)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_mod);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                encode_native_module_item_paths(ebml_w, nmod,
-                                                path + [it.ident], index);
-                ebml::end_tag(ebml_w);
-            }
-            case (item_ty(_, ?tps)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-            }
-            case (item_res(_, _, ?tps, ?ctor_id)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(ctor_id));
-                ebml::end_tag(ebml_w);
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-            }
-            case (item_tag(?variants, ?tps)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-                encode_tag_variant_paths(ebml_w, variants, path, index);
-            }
-            case (item_obj(_, ?tps, ?ctor_id)) {
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(ctor_id));
-                ebml::end_tag(ebml_w);
-                add_to_index(ebml_w, path, index, it.ident);
-                ebml::start_tag(ebml_w, tag_paths_data_item);
-                encode_name(ebml_w, it.ident);
-                encode_def_id(ebml_w, local_def(it.id));
-                ebml::end_tag(ebml_w);
-            }
-        }
-    }
-}
-
-fn encode_item_paths(&ebml::writer ebml_w, &@crate crate) ->
-   vec[tup(str, uint)] {
-    let vec[tup(str, uint)] index = [];
-    let vec[str] path = [];
-    ebml::start_tag(ebml_w, tag_paths);
-    encode_module_item_paths(ebml_w, crate.node.module, path, index);
-    ebml::end_tag(ebml_w);
-    ret index;
-}
-
-
-// Item info table encoding
-fn encode_kind(&ebml::writer ebml_w, u8 c) {
-    ebml::start_tag(ebml_w, tag_items_data_item_kind);
-    ebml_w.writer.write([c]);
-    ebml::end_tag(ebml_w);
-}
-
-fn def_to_str(&def_id did) -> str { ret #fmt("%d:%d", did._0, did._1); }
-
-fn encode_type_param_count(&ebml::writer ebml_w, &vec[ty_param] tps) {
-    ebml::start_tag(ebml_w, tag_items_data_item_ty_param_count);
-    ebml::write_vint(ebml_w.writer, vec::len[ty_param](tps));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_variant_id(&ebml::writer ebml_w, &def_id vid) {
-    ebml::start_tag(ebml_w, tag_items_data_item_variant);
-    ebml_w.writer.write(str::bytes(def_to_str(vid)));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_type(&@trans::crate_ctxt cx, &ebml::writer ebml_w, &ty::t typ) {
-    ebml::start_tag(ebml_w, tag_items_data_item_type);
-    auto f = def_to_str;
-    auto ty_str_ctxt =
-        @rec(ds=f, tcx=cx.tcx, abbrevs=ac_use_abbrevs(cx.type_abbrevs));
-    encode::enc_ty(io::new_writer_(ebml_w.writer), ty_str_ctxt, typ);
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_symbol(&@trans::crate_ctxt cx, &ebml::writer ebml_w,
-                 node_id id) {
-    ebml::start_tag(ebml_w, tag_items_data_item_symbol);
-    ebml_w.writer.write(str::bytes(cx.item_symbols.get(id)));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_discriminant(&@trans::crate_ctxt cx, &ebml::writer ebml_w,
-                       node_id id) {
-    ebml::start_tag(ebml_w, tag_items_data_item_symbol);
-    ebml_w.writer.write(str::bytes(cx.discrim_symbols.get(id)));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_tag_id(&ebml::writer ebml_w, &def_id id) {
-    ebml::start_tag(ebml_w, tag_items_data_item_tag_id);
-    ebml_w.writer.write(str::bytes(def_to_str(id)));
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_tag_variant_info(&@trans::crate_ctxt cx, &ebml::writer ebml_w,
-                           node_id id, &vec[variant] variants,
-                           &mutable vec[tup(int, uint)] index,
-                           &vec[ty_param] ty_params) {
-    for (variant variant in variants) {
-        index += [tup(variant.node.id, ebml_w.writer.tell())];
-        ebml::start_tag(ebml_w, tag_items_data_item);
-        encode_def_id(ebml_w, local_def(variant.node.id));
-        encode_kind(ebml_w, 'v' as u8);
-        encode_tag_id(ebml_w, local_def(id));
-        encode_type(cx, ebml_w, trans::node_id_type(cx, variant.node.id));
-        if (vec::len[variant_arg](variant.node.args) > 0u) {
-            encode_symbol(cx, ebml_w, variant.node.id);
-        }
-        encode_discriminant(cx, ebml_w, variant.node.id);
-        encode_type_param_count(ebml_w, ty_params);
-        ebml::end_tag(ebml_w);
-    }
-}
-
-fn encode_info_for_item(@trans::crate_ctxt cx, &ebml::writer ebml_w,
-                        @item item, &mutable vec[tup(int, uint)] index) {
-    alt (item.node) {
-        case (item_const(_, _)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'c' as u8);
-            encode_type(cx, ebml_w, trans::node_id_type(cx, item.id));
-            encode_symbol(cx, ebml_w, item.id);
-            ebml::end_tag(ebml_w);
-        }
-        case (item_fn(?fd, ?tps)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, alt (fd.decl.purity) {
-                                  case (pure_fn) { 'p' }
-                                  case (impure_fn) { 'f' } } as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, trans::node_id_type(cx, item.id));
-            encode_symbol(cx, ebml_w, item.id);
-            ebml::end_tag(ebml_w);
-        }
-        case (item_mod(_)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'm' as u8);
-            ebml::end_tag(ebml_w);
-        }
-        case (item_native_mod(_)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'n' as u8);
-            ebml::end_tag(ebml_w);
-        }
-        case (item_ty(_, ?tps)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'y' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, trans::node_id_type(cx, item.id));
-            ebml::end_tag(ebml_w);
-        }
-        case (item_tag(?variants, ?tps)) {
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 't' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, trans::node_id_type(cx, item.id));
-            for (variant v in variants) {
-                encode_variant_id(ebml_w, local_def(v.node.id));
-            }
-            ebml::end_tag(ebml_w);
-            encode_tag_variant_info(cx, ebml_w, item.id, variants, index,
-                                    tps);
-        }
-        case (item_res(_, _, ?tps, ?ctor_id)) {
-            auto fn_ty = trans::node_id_type(cx, item.id);
-
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'y' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, ty::ty_fn_ret(cx.tcx, fn_ty));
-            ebml::end_tag(ebml_w);
-
-            index += [tup(ctor_id, ebml_w.writer.tell())];
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(ctor_id));
-            encode_kind(ebml_w, 'f' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, fn_ty);
-            encode_symbol(cx, ebml_w, ctor_id);
-            ebml::end_tag(ebml_w);
-        }
-        case (item_obj(_, ?tps, ?ctor_id)) {
-            auto fn_ty = trans::node_id_type(cx, ctor_id);
-
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(item.id));
-            encode_kind(ebml_w, 'y' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, ty::ty_fn_ret(cx.tcx, fn_ty));
-            ebml::end_tag(ebml_w);
-
-            index += [tup(ctor_id, ebml_w.writer.tell())];
-            ebml::start_tag(ebml_w, tag_items_data_item);
-            encode_def_id(ebml_w, local_def(ctor_id));
-            encode_kind(ebml_w, 'f' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, fn_ty);
-            encode_symbol(cx, ebml_w, ctor_id);
-            ebml::end_tag(ebml_w);
-        }
-    }
-}
-
-fn encode_info_for_native_item(&@trans::crate_ctxt cx, &ebml::writer ebml_w,
-                               &@native_item nitem) {
-    ebml::start_tag(ebml_w, tag_items_data_item);
-    alt (nitem.node) {
-        case (native_item_ty) {
-            encode_def_id(ebml_w, local_def(nitem.id));
-            encode_kind(ebml_w, 'T' as u8);
-            encode_type(cx, ebml_w, ty::mk_native(cx.tcx));
-        }
-        case (native_item_fn(_, _, ?tps)) {
-            encode_def_id(ebml_w, local_def(nitem.id));
-            encode_kind(ebml_w, 'F' as u8);
-            encode_type_param_count(ebml_w, tps);
-            encode_type(cx, ebml_w, trans::node_id_type(cx, nitem.id));
-            encode_symbol(cx, ebml_w, nitem.id);
-        }
-    }
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_info_for_items(&@trans::crate_ctxt cx, &ebml::writer ebml_w) ->
-   vec[tup(int, uint)] {
-    let vec[tup(int, uint)] index = [];
-    ebml::start_tag(ebml_w, tag_items_data);
-    for each (@tup(node_id, ast_map::ast_node) kvp in cx.ast_map.items()) {
-        alt (kvp._1) {
-            case (ast_map::node_item(?i)) {
-                index += [tup(kvp._0, ebml_w.writer.tell())];
-                encode_info_for_item(cx, ebml_w, i, index);
-            }
-            case (ast_map::node_native_item(?i)) {
-                index += [tup(kvp._0, ebml_w.writer.tell())];
-                encode_info_for_native_item(cx, ebml_w, i);
-            }
-            case (_) {}
-        }
-    }
-    ebml::end_tag(ebml_w);
-    ret index;
-}
-
-
-// Path and definition ID indexing
-
-// djb's cdb hashes.
-fn hash_def_id(&int def_id) -> uint { ret 177573u ^ (def_id as uint); }
-
-fn hash_path(&str s) -> uint {
-    auto h = 5381u;
-    for (u8 ch in str::bytes(s)) { h = (h << 5u) + h ^ (ch as uint); }
-    ret h;
-}
-
-fn create_index[T](&vec[tup(T, uint)] index, fn(&T) -> uint  hash_fn) ->
-   vec[vec[tup(T, uint)]] {
-    let vec[mutable vec[tup(T, uint)]] buckets = vec::empty_mut();
-    for each (uint i in uint::range(0u, 256u)) { buckets += [mutable []]; }
-    for (tup(T, uint) elt in index) {
-        auto h = hash_fn(elt._0);
-        buckets.(h % 256u) += [elt];
-    }
-    ret vec::freeze(buckets);
-}
-
-fn encode_index[T](&ebml::writer ebml_w, &vec[vec[tup(T, uint)]] buckets,
-                   fn(&io::writer, &T)  write_fn) {
-    auto writer = io::new_writer_(ebml_w.writer);
-    ebml::start_tag(ebml_w, tag_index);
-    let vec[uint] bucket_locs = [];
-    ebml::start_tag(ebml_w, tag_index_buckets);
-    for (vec[tup(T, uint)] bucket in buckets) {
-        bucket_locs += [ebml_w.writer.tell()];
-        ebml::start_tag(ebml_w, tag_index_buckets_bucket);
-        for (tup(T, uint) elt in bucket) {
-            ebml::start_tag(ebml_w, tag_index_buckets_bucket_elt);
-            writer.write_be_uint(elt._1, 4u);
-            write_fn(writer, elt._0);
-            ebml::end_tag(ebml_w);
-        }
-        ebml::end_tag(ebml_w);
-    }
-    ebml::end_tag(ebml_w);
-    ebml::start_tag(ebml_w, tag_index_table);
-    for (uint pos in bucket_locs) { writer.write_be_uint(pos, 4u); }
-    ebml::end_tag(ebml_w);
-    ebml::end_tag(ebml_w);
-}
-
-fn write_str(&io::writer writer, &str s) { writer.write_str(s); }
-
-fn write_int(&io::writer writer, &int n) {
-    writer.write_be_uint(n as uint, 4u);
-}
-
-fn encode_meta_items(&ebml::writer ebml_w, &crate crate) {
-    fn encode_meta_item(&ebml::writer ebml_w, &meta_item mi) {
-        // FIXME (#487): Support all forms of meta item
-        ebml::start_tag(ebml_w, tag_meta_item);
-        alt (mi.node) {
-            case (meta_key_value(?key, ?value)) {
-                ebml::start_tag(ebml_w, tag_meta_item_key);
-                ebml_w.writer.write(str::bytes(key));
-                ebml::end_tag(ebml_w);
-                ebml::start_tag(ebml_w, tag_meta_item_value);
-                ebml_w.writer.write(str::bytes(value));
-                ebml::end_tag(ebml_w);
-            }
-            case (_) {
-                log_err "unimplemented meta_item type";
-            }
-        }
-        ebml::end_tag(ebml_w);
-    }
-    ebml::start_tag(ebml_w, tag_meta_export);
-    for each (@meta_item mi in link::crate_export_metas(crate)) {
-        encode_meta_item(ebml_w, *mi);
-    }
-    ebml::end_tag(ebml_w);
-    ebml::start_tag(ebml_w, tag_meta_local);
-    for each (@meta_item mi in link::crate_local_metas(crate)) {
-        encode_meta_item(ebml_w, *mi);
-    }
-    ebml::end_tag(ebml_w);
-}
-
-fn encode_metadata(&@trans::crate_ctxt cx, &@crate crate) -> ValueRef {
-    auto string_w = io::string_writer();
-    auto buf_w = string_w.get_writer().get_buf_writer();
-    auto ebml_w = ebml::create_writer(buf_w);
-    // Encode the meta items
-
-    encode_meta_items(ebml_w, *crate);
-    // Encode and index the paths.
-
-    ebml::start_tag(ebml_w, tag_paths);
-    auto paths_index = encode_item_paths(ebml_w, crate);
-    auto str_writer = write_str;
-    auto path_hasher = hash_path;
-    auto paths_buckets = create_index[str](paths_index, path_hasher);
-    encode_index[str](ebml_w, paths_buckets, str_writer);
-    ebml::end_tag(ebml_w);
-    // Encode and index the items.
-
-    ebml::start_tag(ebml_w, tag_items);
-    auto items_index = encode_info_for_items(cx, ebml_w);
-    auto int_writer = write_int;
-    auto item_hasher = hash_def_id;
-    auto items_buckets = create_index[int](items_index, item_hasher);
-    encode_index[int](ebml_w, items_buckets, int_writer);
-    ebml::end_tag(ebml_w);
-    // Pad this, since something (LLVM, presumably) is cutting off the
-    // remaining % 4 bytes.
-
-    buf_w.write([0u8, 0u8, 0u8, 0u8]);
-    ret C_postr(string_w.get_str());
-}
-
-fn write_metadata(&@trans::crate_ctxt cx, &@crate crate) {
-    if (!cx.sess.get_opts().shared) { ret; }
-    auto llmeta = encode_metadata(cx, crate);
-    auto llconst = trans::C_struct([llmeta]);
-    auto llglobal =
-        llvm::LLVMAddGlobal(cx.llmod, trans::val_ty(llconst),
-                            str::buf("rust_metadata"));
-    llvm::LLVMSetInitializer(llglobal, llconst);
-    llvm::LLVMSetSection(llglobal, str::buf(x86::get_meta_sect_name()));
-}
-//
-// Local Variables:
-// mode: rust
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
-// End:
-//
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index b9f6c604996..6e2ecfcac55 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -6,7 +6,7 @@ import front::ast::def_id;
 import front::ast::node_id;
 import front::ast::local_def;
 
-import front::creader;
+import metadata::creader;
 import driver::session::session;
 import util::common::new_def_hash;
 import util::common::new_int_hash;
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index b5f255a7b02..b6bf494d8dd 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -25,7 +25,8 @@ import std::option::some;
 import std::option::none;
 import std::fs;
 import front::ast;
-import front::creader;
+import metadata::creader;
+import metadata::cwriter;
 import driver::session;
 import middle::ty;
 import back::link;
@@ -148,7 +149,7 @@ type crate_ctxt =
         namegen names,
         std::sha1::sha1 sha,
         hashmap[ty::t, str] type_sha1s,
-        hashmap[ty::t, metadata::ty_abbrev] type_abbrevs,
+        hashmap[ty::t, cwriter::ty_abbrev] type_abbrevs,
         hashmap[ty::t, str] type_short_names,
         ty::ctxt tcx,
         stats stats,
@@ -8400,7 +8401,7 @@ fn trans_crate(&session::session sess, &@ast::crate crate, &ty::ctxt tcx,
     auto tydescs = map::mk_hashmap[ty::t, @tydesc_info](hasher, eqer);
     auto lltypes = map::mk_hashmap[ty::t, TypeRef](hasher, eqer);
     auto sha1s = map::mk_hashmap[ty::t, str](hasher, eqer);
-    auto abbrevs = map::mk_hashmap[ty::t, metadata::ty_abbrev](hasher, eqer);
+    auto abbrevs = map::mk_hashmap[ty::t, cwriter::ty_abbrev](hasher, eqer);
     auto short_names = map::mk_hashmap[ty::t, str](hasher, eqer);
     auto sha = std::sha1::mk_sha1();
     auto ccx =
@@ -8449,7 +8450,7 @@ fn trans_crate(&session::session sess, &@ast::crate crate, &ty::ctxt tcx,
     emit_tydescs(ccx);
     // Translate the metadata:
 
-    middle::metadata::write_metadata(cx.ccx, crate);
+    cwriter::write_metadata(cx.ccx, crate);
     if (ccx.sess.get_opts().stats) {
         log_err "--- trans stats ---";
         log_err #fmt("n_static_tydescs: %u", ccx.stats.n_static_tydescs);
diff --git a/src/comp/middle/ty.rs b/src/comp/middle/ty.rs
index f9397a05adf..88f1f098567 100644
--- a/src/comp/middle/ty.rs
+++ b/src/comp/middle/ty.rs
@@ -17,8 +17,8 @@ import front::ast::def_id;
 import front::ast::constr_arg_general;
 import front::ast::mutability;
 import front::ast::controlflow;
-import front::creader;
-import middle::metadata;
+import metadata::creader;
+import metadata::cwriter;
 import util::common::*;
 import util::data::interner;
 import pretty::ppaux::ty_to_str;
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index b851f5e9fb9..41a255bcaaa 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -2,7 +2,7 @@
 import front::ast;
 import front::ast::mutability;
 import front::ast::local_def;
-import front::creader;
+import metadata::creader;
 import driver::session;
 import util::common;
 import util::common::span;