diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
index c22a432ad78d..3a9c68fcbe51 100644
--- a/src/librustc/back/link.rs
+++ b/src/librustc/back/link.rs
@@ -18,7 +18,7 @@ use lib::llvm::ModuleRef;
 use lib;
 use metadata::common::LinkMeta;
 use metadata::{encoder, csearch, cstore};
-use middle::trans::common::CrateContext;
+use middle::trans::context::CrateContext;
 use middle::ty;
 use util::ppaux;
 
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index ff2f3841040d..abfce3660070 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -55,6 +55,8 @@ use syntax::parse::token;
 use syntax::{ast, ast_map};
 use syntax::abi::{X86, X86_64, Arm, Mips};
 
+pub use middle::trans::context::CrateContext;
+
 // NOTE: this thunk is totally pointless now that we're not passing
 // interners around...
 pub type namegen = @fn(s: &str) -> ident;
@@ -156,86 +158,6 @@ pub fn BuilderRef_res(B: BuilderRef) -> BuilderRef_res {
 
 pub type ExternMap = @mut HashMap<@str, ValueRef>;
 
-// Crate context.  Every crate we compile has one of these.
-pub struct CrateContext {
-     sess: session::Session,
-     llmod: ModuleRef,
-     llcx: ContextRef,
-     td: TargetData,
-     tn: @TypeNames,
-     externs: ExternMap,
-     intrinsics: HashMap<&'static str, ValueRef>,
-     item_vals: @mut HashMap<ast::node_id, ValueRef>,
-     exp_map2: resolve::ExportMap2,
-     reachable: reachable::map,
-     item_symbols: @mut HashMap<ast::node_id, ~str>,
-     link_meta: LinkMeta,
-     enum_sizes: @mut HashMap<ty::t, uint>,
-     discrims: @mut HashMap<ast::def_id, ValueRef>,
-     discrim_symbols: @mut HashMap<ast::node_id, @str>,
-     tydescs: @mut HashMap<ty::t, @mut tydesc_info>,
-     // Set when running emit_tydescs to enforce that no more tydescs are
-     // created.
-     finished_tydescs: @mut bool,
-     // Track mapping of external ids to local items imported for inlining
-     external: @mut HashMap<ast::def_id, Option<ast::node_id>>,
-     // Cache instances of monomorphized functions
-     monomorphized: @mut HashMap<mono_id, ValueRef>,
-     monomorphizing: @mut HashMap<ast::def_id, uint>,
-     // Cache computed type parameter uses (see type_use.rs)
-     type_use_cache: @mut HashMap<ast::def_id, @~[type_use::type_uses]>,
-     // Cache generated vtables
-     vtables: @mut HashMap<mono_id, ValueRef>,
-     // Cache of constant strings,
-     const_cstr_cache: @mut HashMap<@str, ValueRef>,
-
-     // Reverse-direction for const ptrs cast from globals.
-     // Key is an int, cast from a ValueRef holding a *T,
-     // Val is a ValueRef holding a *[T].
-     //
-     // Needed because LLVM loses pointer->pointee association
-     // when we ptrcast, and we have to ptrcast during translation
-     // of a [T] const because we form a slice, a [*T,int] pair, not
-     // a pointer to an LLVM array type.
-     const_globals: @mut HashMap<int, ValueRef>,
-
-     // Cache of emitted const values
-     const_values: @mut HashMap<ast::node_id, ValueRef>,
-
-     // Cache of external const values
-     extern_const_values: @mut HashMap<ast::def_id, ValueRef>,
-
-     impl_method_cache: @mut HashMap<(ast::def_id, ast::ident), ast::def_id>,
-
-     module_data: @mut HashMap<~str, ValueRef>,
-     lltypes: @mut HashMap<ty::t, TypeRef>,
-     llsizingtypes: @mut HashMap<ty::t, TypeRef>,
-     adt_reprs: @mut HashMap<ty::t, @adt::Repr>,
-     names: namegen,
-     next_addrspace: addrspace_gen,
-     symbol_hasher: @mut hash::State,
-     type_hashcodes: @mut HashMap<ty::t, @str>,
-     type_short_names: @mut HashMap<ty::t, ~str>,
-     all_llvm_symbols: @mut HashSet<@str>,
-     tcx: ty::ctxt,
-     maps: astencode::Maps,
-     stats: @mut Stats,
-     upcalls: @upcall::Upcalls,
-     tydesc_type: TypeRef,
-     int_type: TypeRef,
-     float_type: TypeRef,
-     opaque_vec_type: TypeRef,
-     builder: BuilderRef_res,
-     shape_cx: shape::Ctxt,
-     crate_map: ValueRef,
-     // Set when at least one function uses GC. Needed so that
-     // decl_gc_metadata knows whether to link to the module metadata, which
-     // is not emitted by LLVM's GC pass when no functions use GC.
-     uses_gc: @mut bool,
-     dbg_cx: Option<debuginfo::DebugContext>,
-     do_not_commit_warning_issued: @mut bool
-}
-
 // Types used for llself.
 pub struct ValSelfData {
     v: ValueRef,
diff --git a/src/librustc/middle/trans/context.rs b/src/librustc/middle/trans/context.rs
new file mode 100644
index 000000000000..6d090e444bf3
--- /dev/null
+++ b/src/librustc/middle/trans/context.rs
@@ -0,0 +1,123 @@
+use core::prelude::*;
+
+use back::{abi, upcall};
+use driver::session;
+use driver::session::Session;
+use lib::llvm::{ModuleRef, ValueRef, TypeRef, BasicBlockRef, BuilderRef};
+use lib::llvm::{ContextRef, True, False, Bool};
+use lib::llvm::{llvm, TargetData, TypeNames, associate_type, name_has_type};
+use lib;
+use metadata::common::LinkMeta;
+use middle::astencode;
+use middle::resolve;
+use middle::trans::adt;
+use middle::trans::base;
+use middle::trans::build;
+use middle::trans::datum;
+use middle::trans::debuginfo;
+use middle::trans::glue;
+use middle::trans::reachable;
+use middle::trans::shape;
+use middle::trans::type_of;
+use middle::trans::type_use;
+use middle::trans::write_guard;
+use middle::ty::substs;
+use middle::ty;
+use middle::typeck;
+use middle::borrowck::root_map_key;
+
+use core::cast::transmute;
+use core::cast;
+use core::hash;
+use core::hashmap::{HashMap, HashSet};
+use core::libc::{c_uint, c_longlong, c_ulonglong};
+use core::str;
+use core::to_bytes;
+use core::vec::raw::to_ptr;
+use core::vec;
+use syntax::ast::ident;
+use syntax::ast_map::{path, path_elt};
+use syntax::codemap::span;
+use syntax::parse::token;
+use syntax::{ast, ast_map};
+use syntax::abi::{X86, X86_64, Arm, Mips};
+
+use middle::trans::common::{ExternMap,tydesc_info,BuilderRef_res,Stats,namegen,addrspace_gen};
+use middle::trans::common::{mono_id};
+
+pub struct CrateContext {
+     sess: session::Session,
+     llmod: ModuleRef,
+     llcx: ContextRef,
+     td: TargetData,
+     tn: @TypeNames,
+     externs: ExternMap,
+     intrinsics: HashMap<&'static str, ValueRef>,
+     item_vals: @mut HashMap<ast::node_id, ValueRef>,
+     exp_map2: resolve::ExportMap2,
+     reachable: reachable::map,
+     item_symbols: @mut HashMap<ast::node_id, ~str>,
+     link_meta: LinkMeta,
+     enum_sizes: @mut HashMap<ty::t, uint>,
+     discrims: @mut HashMap<ast::def_id, ValueRef>,
+     discrim_symbols: @mut HashMap<ast::node_id, @str>,
+     tydescs: @mut HashMap<ty::t, @mut tydesc_info>,
+     // Set when running emit_tydescs to enforce that no more tydescs are
+     // created.
+     finished_tydescs: @mut bool,
+     // Track mapping of external ids to local items imported for inlining
+     external: @mut HashMap<ast::def_id, Option<ast::node_id>>,
+     // Cache instances of monomorphized functions
+     monomorphized: @mut HashMap<mono_id, ValueRef>,
+     monomorphizing: @mut HashMap<ast::def_id, uint>,
+     // Cache computed type parameter uses (see type_use.rs)
+     type_use_cache: @mut HashMap<ast::def_id, @~[type_use::type_uses]>,
+     // Cache generated vtables
+     vtables: @mut HashMap<mono_id, ValueRef>,
+     // Cache of constant strings,
+     const_cstr_cache: @mut HashMap<@str, ValueRef>,
+
+     // Reverse-direction for const ptrs cast from globals.
+     // Key is an int, cast from a ValueRef holding a *T,
+     // Val is a ValueRef holding a *[T].
+     //
+     // Needed because LLVM loses pointer->pointee association
+     // when we ptrcast, and we have to ptrcast during translation
+     // of a [T] const because we form a slice, a [*T,int] pair, not
+     // a pointer to an LLVM array type.
+     const_globals: @mut HashMap<int, ValueRef>,
+
+     // Cache of emitted const values
+     const_values: @mut HashMap<ast::node_id, ValueRef>,
+
+     // Cache of external const values
+     extern_const_values: @mut HashMap<ast::def_id, ValueRef>,
+
+     module_data: @mut HashMap<~str, ValueRef>,
+     lltypes: @mut HashMap<ty::t, TypeRef>,
+     llsizingtypes: @mut HashMap<ty::t, TypeRef>,
+     adt_reprs: @mut HashMap<ty::t, @adt::Repr>,
+     names: namegen,
+     next_addrspace: addrspace_gen,
+     symbol_hasher: @mut hash::State,
+     type_hashcodes: @mut HashMap<ty::t, @str>,
+     type_short_names: @mut HashMap<ty::t, ~str>,
+     all_llvm_symbols: @mut HashSet<@str>,
+     tcx: ty::ctxt,
+     maps: astencode::Maps,
+     stats: @mut Stats,
+     upcalls: @upcall::Upcalls,
+     tydesc_type: TypeRef,
+     int_type: TypeRef,
+     float_type: TypeRef,
+     opaque_vec_type: TypeRef,
+     builder: BuilderRef_res,
+     shape_cx: shape::Ctxt,
+     crate_map: ValueRef,
+     // Set when at least one function uses GC. Needed so that
+     // decl_gc_metadata knows whether to link to the module metadata, which
+     // is not emitted by LLVM's GC pass when no functions use GC.
+     uses_gc: @mut bool,
+     dbg_cx: Option<debuginfo::DebugContext>,
+     do_not_commit_warning_issued: @mut bool
+}
diff --git a/src/librustc/middle/trans/mod.rs b/src/librustc/middle/trans/mod.rs
index d96ba8041719..49cadfbcc81a 100644
--- a/src/librustc/middle/trans/mod.rs
+++ b/src/librustc/middle/trans/mod.rs
@@ -18,6 +18,7 @@ pub mod write_guard;
 pub mod callee;
 pub mod expr;
 pub mod common;
+pub mod context;
 pub mod consts;
 pub mod type_of;
 pub mod build;