1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
12 // file at the top-level directory of this distribution and at
13 // http://rust-lang.org/COPYRIGHT.
15 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
16 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
17 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
18 // option. This file may not be copied, modified, or distributed
19 // except according to those terms.
21 // the rustc crate store interface. This also includes types that
22 // are *mostly* used as a part of that interface, but these should
23 // probably get a better home if someone can find one.
26 use front::map as hir_map;
27 use middle::def::{self, Def};
28 use middle::lang_items;
29 use middle::ty::{self, Ty, VariantKind};
30 use middle::def_id::{DefId, DefIndex};
33 use session::search_paths::PathKind;
34 use util::nodemap::{FnvHashMap, NodeMap, NodeSet};
36 use std::cell::RefCell;
38 use std::path::PathBuf;
40 use syntax::ast_util::{IdVisitingOperation};
42 use syntax::codemap::Span;
44 use rustc_back::target::Target;
46 use rustc_front::intravisit::Visitor;
47 use rustc_front::util::IdVisitor;
49 pub use self::DefLike::{DlDef, DlField, DlImpl};
50 pub use self::NativeLibraryKind::{NativeStatic, NativeFramework, NativeUnknown};
52 // lonely orphan structs and enums looking for a better home
54 #[derive(Clone, Debug)]
56 pub crate_name: String,
60 // Where a crate came from on the local filesystem. One of these two options
62 #[derive(PartialEq, Clone, Debug)]
63 pub struct CrateSource {
64 pub dylib: Option<(PathBuf, PathKind)>,
65 pub rlib: Option<(PathBuf, PathKind)>,
66 pub cnum: ast::CrateNum,
69 #[derive(Copy, Debug, PartialEq, Clone)]
70 pub enum LinkagePreference {
76 #[derive(Copy, Clone, PartialEq)]
77 pub enum NativeLibraryKind {
78 NativeStatic, // native static library (.a archive)
79 NativeFramework, // OSX-specific
80 NativeUnknown, // default way to specify a dynamic library
84 // Something that a name can resolve to.
85 #[derive(Copy, Clone, Debug)]
92 /// The data we save and restore about an inlined item or method. This is not
93 /// part of the AST that we parse from a file, but it becomes part of the tree
95 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
96 pub enum InlinedItem {
98 TraitItem(DefId /* impl id */, P<hir::TraitItem>),
99 ImplItem(DefId /* impl id */, P<hir::ImplItem>),
100 Foreign(P<hir::ForeignItem>),
103 /// A borrowed version of `hir::InlinedItem`.
104 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
105 pub enum InlinedItemRef<'a> {
107 TraitItem(DefId, &'a hir::TraitItem),
108 ImplItem(DefId, &'a hir::ImplItem),
109 Foreign(&'a hir::ForeignItem)
112 /// Item definitions in the currently-compiled crate would have the CrateNum
113 /// LOCAL_CRATE in their DefId.
114 pub const LOCAL_CRATE: ast::CrateNum = 0;
116 pub struct ChildItem {
119 pub vis: hir::Visibility
122 pub enum FoundAst<'ast> {
123 Found(&'ast InlinedItem),
124 FoundParent(DefId, &'ast InlinedItem),
128 /// A store of Rust crates, through with their metadata
131 /// The `: Any` bound is a temporary measure that allows access
132 /// to the backing `rustc_metadata::cstore::CStore` object. It
133 /// will be removed in the near future - if you need to access
134 /// internal APIs, please tell us.
135 pub trait CrateStore<'tcx> : Any {
137 fn stability(&self, def: DefId) -> Option<attr::Stability>;
138 fn deprecation(&self, def: DefId) -> Option<attr::Deprecation>;
139 fn closure_kind(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
141 fn closure_ty(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
142 -> ty::ClosureTy<'tcx>;
143 fn item_variances(&self, def: DefId) -> ty::ItemVariances;
144 fn repr_attrs(&self, def: DefId) -> Vec<attr::ReprAttr>;
145 fn item_type(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
146 -> ty::TypeScheme<'tcx>;
147 fn item_path(&self, def: DefId) -> Vec<hir_map::PathElem>;
148 fn extern_item_path(&self, def: DefId) -> Vec<hir_map::PathElem>;
149 fn item_name(&self, def: DefId) -> ast::Name;
150 fn item_predicates(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
151 -> ty::GenericPredicates<'tcx>;
152 fn item_super_predicates(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
153 -> ty::GenericPredicates<'tcx>;
154 fn item_attrs(&self, def_id: DefId) -> Vec<ast::Attribute>;
155 fn item_symbol(&self, def: DefId) -> String;
156 fn trait_def(&self, tcx: &ty::ctxt<'tcx>, def: DefId)-> ty::TraitDef<'tcx>;
157 fn adt_def(&self, tcx: &ty::ctxt<'tcx>, def: DefId) -> ty::AdtDefMaster<'tcx>;
158 fn method_arg_names(&self, did: DefId) -> Vec<String>;
159 fn inherent_implementations_for_type(&self, def_id: DefId) -> Vec<DefId>;
162 fn implementations_of_trait(&self, def_id: DefId) -> Vec<DefId>;
163 fn provided_trait_methods(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
164 -> Vec<Rc<ty::Method<'tcx>>>;
165 fn trait_item_def_ids(&self, def: DefId)
166 -> Vec<ty::ImplOrTraitItemId>;
169 fn impl_items(&self, impl_def_id: DefId) -> Vec<ty::ImplOrTraitItemId>;
170 fn impl_trait_ref(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
171 -> Option<ty::TraitRef<'tcx>>;
172 fn impl_polarity(&self, def: DefId) -> Option<hir::ImplPolarity>;
173 fn custom_coerce_unsized_kind(&self, def: DefId)
174 -> Option<ty::adjustment::CustomCoerceUnsized>;
175 fn associated_consts(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
176 -> Vec<Rc<ty::AssociatedConst<'tcx>>>;
178 // trait/impl-item info
179 fn trait_of_item(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
181 fn impl_or_trait_item(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
182 -> ty::ImplOrTraitItem<'tcx>;
185 fn is_const_fn(&self, did: DefId) -> bool;
186 fn is_defaulted_trait(&self, did: DefId) -> bool;
187 fn is_impl(&self, did: DefId) -> bool;
188 fn is_default_impl(&self, impl_did: DefId) -> bool;
189 fn is_extern_fn(&self, tcx: &ty::ctxt<'tcx>, did: DefId) -> bool;
190 fn is_static(&self, did: DefId) -> bool;
191 fn is_static_method(&self, did: DefId) -> bool;
192 fn is_statically_included_foreign_item(&self, id: ast::NodeId) -> bool;
193 fn is_typedef(&self, did: DefId) -> bool;
196 fn dylib_dependency_formats(&self, cnum: ast::CrateNum)
197 -> Vec<(ast::CrateNum, LinkagePreference)>;
198 fn lang_items(&self, cnum: ast::CrateNum) -> Vec<(DefIndex, usize)>;
199 fn missing_lang_items(&self, cnum: ast::CrateNum) -> Vec<lang_items::LangItem>;
200 fn is_staged_api(&self, cnum: ast::CrateNum) -> bool;
201 fn is_explicitly_linked(&self, cnum: ast::CrateNum) -> bool;
202 fn is_allocator(&self, cnum: ast::CrateNum) -> bool;
203 fn crate_attrs(&self, cnum: ast::CrateNum) -> Vec<ast::Attribute>;
204 fn crate_name(&self, cnum: ast::CrateNum) -> String;
205 fn crate_hash(&self, cnum: ast::CrateNum) -> Svh;
206 fn crate_struct_field_attrs(&self, cnum: ast::CrateNum)
207 -> FnvHashMap<DefId, Vec<ast::Attribute>>;
208 fn plugin_registrar_fn(&self, cnum: ast::CrateNum) -> Option<DefId>;
209 fn native_libraries(&self, cnum: ast::CrateNum) -> Vec<(NativeLibraryKind, String)>;
210 fn reachable_ids(&self, cnum: ast::CrateNum) -> Vec<DefId>;
213 fn def_path(&self, def: DefId) -> hir_map::DefPath;
214 fn variant_kind(&self, def_id: DefId) -> Option<VariantKind>;
215 fn struct_ctor_def_id(&self, struct_def_id: DefId) -> Option<DefId>;
216 fn tuple_struct_definition_if_ctor(&self, did: DefId) -> Option<DefId>;
217 fn struct_field_names(&self, def: DefId) -> Vec<ast::Name>;
218 fn item_children(&self, did: DefId) -> Vec<ChildItem>;
219 fn crate_top_level_items(&self, cnum: ast::CrateNum) -> Vec<ChildItem>;
222 fn maybe_get_item_ast(&'tcx self, tcx: &ty::ctxt<'tcx>, def: DefId)
224 fn maybe_get_item_mir(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
225 -> Option<Mir<'tcx>>;
226 fn is_item_mir_available(&self, def: DefId) -> bool;
228 // This is basically a 1-based range of ints, which is a little
229 // silly - I may fix that.
230 fn crates(&self) -> Vec<ast::CrateNum>;
231 fn used_libraries(&self) -> Vec<(String, NativeLibraryKind)>;
232 fn used_link_args(&self) -> Vec<String>;
235 fn metadata_filename(&self) -> &str;
236 fn metadata_section_name(&self, target: &Target) -> &str;
237 fn encode_type(&self, tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> Vec<u8>;
238 fn used_crates(&self, prefer: LinkagePreference) -> Vec<(ast::CrateNum, Option<PathBuf>)>;
239 fn used_crate_source(&self, cnum: ast::CrateNum) -> CrateSource;
240 fn extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<ast::CrateNum>;
241 fn encode_metadata(&self,
242 tcx: &ty::ctxt<'tcx>,
243 reexports: &def::ExportMap,
244 item_symbols: &RefCell<NodeMap<String>>,
245 link_meta: &LinkMeta,
247 mir_map: &NodeMap<Mir<'tcx>>,
248 krate: &hir::Crate) -> Vec<u8>;
249 fn metadata_encoding_version(&self) -> &[u8];
253 pub fn visit<'ast,V>(&'ast self, visitor: &mut V)
254 where V: Visitor<'ast>
257 InlinedItem::Item(ref i) => visitor.visit_item(&**i),
258 InlinedItem::Foreign(ref i) => visitor.visit_foreign_item(&**i),
259 InlinedItem::TraitItem(_, ref ti) => visitor.visit_trait_item(ti),
260 InlinedItem::ImplItem(_, ref ii) => visitor.visit_impl_item(ii),
264 pub fn visit_ids<O: IdVisitingOperation>(&self, operation: &mut O) {
265 let mut id_visitor = IdVisitor::new(operation);
266 self.visit(&mut id_visitor);
270 // FIXME: find a better place for this?
271 pub fn validate_crate_name(sess: Option<&Session>, s: &str, sp: Option<Span>) {
272 let mut err_count = 0;
274 let mut say = |s: &str| {
276 (_, None) => panic!("{}", s),
277 (Some(sp), Some(sess)) => sess.span_err(sp, s),
278 (None, Some(sess)) => sess.err(s),
283 say("crate name must not be empty");
286 if c.is_alphanumeric() { continue }
287 if c == '_' { continue }
288 say(&format!("invalid character `{}` in crate name: `{}`", c, s));
293 sess.unwrap().abort_if_errors();
297 /// A dummy crate store that does not support any non-local crates,
298 /// for test purposes.
299 pub struct DummyCrateStore;
300 #[allow(unused_variables)]
301 impl<'tcx> CrateStore<'tcx> for DummyCrateStore {
303 fn stability(&self, def: DefId) -> Option<attr::Stability> { unimplemented!() }
304 fn deprecation(&self, def: DefId) -> Option<attr::Deprecation> { unimplemented!() }
305 fn closure_kind(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
306 -> ty::ClosureKind { unimplemented!() }
307 fn closure_ty(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
308 -> ty::ClosureTy<'tcx> { unimplemented!() }
309 fn item_variances(&self, def: DefId) -> ty::ItemVariances { unimplemented!() }
310 fn repr_attrs(&self, def: DefId) -> Vec<attr::ReprAttr> { unimplemented!() }
311 fn item_type(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
312 -> ty::TypeScheme<'tcx> { unimplemented!() }
313 fn item_path(&self, def: DefId) -> Vec<hir_map::PathElem> { unimplemented!() }
314 fn extern_item_path(&self, def: DefId) -> Vec<hir_map::PathElem> { unimplemented!() }
315 fn item_name(&self, def: DefId) -> ast::Name { unimplemented!() }
316 fn item_predicates(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
317 -> ty::GenericPredicates<'tcx> { unimplemented!() }
318 fn item_super_predicates(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
319 -> ty::GenericPredicates<'tcx> { unimplemented!() }
320 fn item_attrs(&self, def_id: DefId) -> Vec<ast::Attribute> { unimplemented!() }
321 fn item_symbol(&self, def: DefId) -> String { unimplemented!() }
322 fn trait_def(&self, tcx: &ty::ctxt<'tcx>, def: DefId)-> ty::TraitDef<'tcx>
324 fn adt_def(&self, tcx: &ty::ctxt<'tcx>, def: DefId) -> ty::AdtDefMaster<'tcx>
326 fn method_arg_names(&self, did: DefId) -> Vec<String> { unimplemented!() }
327 fn inherent_implementations_for_type(&self, def_id: DefId) -> Vec<DefId> { vec![] }
330 fn implementations_of_trait(&self, def_id: DefId) -> Vec<DefId> { vec![] }
331 fn provided_trait_methods(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
332 -> Vec<Rc<ty::Method<'tcx>>> { unimplemented!() }
333 fn trait_item_def_ids(&self, def: DefId)
334 -> Vec<ty::ImplOrTraitItemId> { unimplemented!() }
337 fn impl_items(&self, impl_def_id: DefId) -> Vec<ty::ImplOrTraitItemId>
339 fn impl_trait_ref(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
340 -> Option<ty::TraitRef<'tcx>> { unimplemented!() }
341 fn impl_polarity(&self, def: DefId) -> Option<hir::ImplPolarity> { unimplemented!() }
342 fn custom_coerce_unsized_kind(&self, def: DefId)
343 -> Option<ty::adjustment::CustomCoerceUnsized>
345 fn associated_consts(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
346 -> Vec<Rc<ty::AssociatedConst<'tcx>>> { unimplemented!() }
348 // trait/impl-item info
349 fn trait_of_item(&self, tcx: &ty::ctxt<'tcx>, def_id: DefId)
350 -> Option<DefId> { unimplemented!() }
351 fn impl_or_trait_item(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
352 -> ty::ImplOrTraitItem<'tcx> { unimplemented!() }
355 fn is_const_fn(&self, did: DefId) -> bool { unimplemented!() }
356 fn is_defaulted_trait(&self, did: DefId) -> bool { unimplemented!() }
357 fn is_impl(&self, did: DefId) -> bool { unimplemented!() }
358 fn is_default_impl(&self, impl_did: DefId) -> bool { unimplemented!() }
359 fn is_extern_fn(&self, tcx: &ty::ctxt<'tcx>, did: DefId) -> bool { unimplemented!() }
360 fn is_static(&self, did: DefId) -> bool { unimplemented!() }
361 fn is_static_method(&self, did: DefId) -> bool { unimplemented!() }
362 fn is_statically_included_foreign_item(&self, id: ast::NodeId) -> bool { false }
363 fn is_typedef(&self, did: DefId) -> bool { unimplemented!() }
366 fn dylib_dependency_formats(&self, cnum: ast::CrateNum)
367 -> Vec<(ast::CrateNum, LinkagePreference)>
369 fn lang_items(&self, cnum: ast::CrateNum) -> Vec<(DefIndex, usize)>
371 fn missing_lang_items(&self, cnum: ast::CrateNum) -> Vec<lang_items::LangItem>
373 fn is_staged_api(&self, cnum: ast::CrateNum) -> bool { unimplemented!() }
374 fn is_explicitly_linked(&self, cnum: ast::CrateNum) -> bool { unimplemented!() }
375 fn is_allocator(&self, cnum: ast::CrateNum) -> bool { unimplemented!() }
376 fn crate_attrs(&self, cnum: ast::CrateNum) -> Vec<ast::Attribute>
378 fn crate_name(&self, cnum: ast::CrateNum) -> String { unimplemented!() }
379 fn crate_hash(&self, cnum: ast::CrateNum) -> Svh { unimplemented!() }
380 fn crate_struct_field_attrs(&self, cnum: ast::CrateNum)
381 -> FnvHashMap<DefId, Vec<ast::Attribute>>
383 fn plugin_registrar_fn(&self, cnum: ast::CrateNum) -> Option<DefId>
385 fn native_libraries(&self, cnum: ast::CrateNum) -> Vec<(NativeLibraryKind, String)>
387 fn reachable_ids(&self, cnum: ast::CrateNum) -> Vec<DefId> { unimplemented!() }
390 fn def_path(&self, def: DefId) -> hir_map::DefPath { unimplemented!() }
391 fn variant_kind(&self, def_id: DefId) -> Option<VariantKind> { unimplemented!() }
392 fn struct_ctor_def_id(&self, struct_def_id: DefId) -> Option<DefId>
394 fn tuple_struct_definition_if_ctor(&self, did: DefId) -> Option<DefId>
396 fn struct_field_names(&self, def: DefId) -> Vec<ast::Name> { unimplemented!() }
397 fn item_children(&self, did: DefId) -> Vec<ChildItem> { unimplemented!() }
398 fn crate_top_level_items(&self, cnum: ast::CrateNum) -> Vec<ChildItem>
402 fn maybe_get_item_ast(&'tcx self, tcx: &ty::ctxt<'tcx>, def: DefId)
403 -> FoundAst<'tcx> { unimplemented!() }
404 fn maybe_get_item_mir(&self, tcx: &ty::ctxt<'tcx>, def: DefId)
405 -> Option<Mir<'tcx>> { unimplemented!() }
406 fn is_item_mir_available(&self, def: DefId) -> bool {
410 // This is basically a 1-based range of ints, which is a little
411 // silly - I may fix that.
412 fn crates(&self) -> Vec<ast::CrateNum> { vec![] }
413 fn used_libraries(&self) -> Vec<(String, NativeLibraryKind)> { vec![] }
414 fn used_link_args(&self) -> Vec<String> { vec![] }
417 fn metadata_filename(&self) -> &str { unimplemented!() }
418 fn metadata_section_name(&self, target: &Target) -> &str { unimplemented!() }
419 fn encode_type(&self, tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> Vec<u8>
421 fn used_crates(&self, prefer: LinkagePreference) -> Vec<(ast::CrateNum, Option<PathBuf>)>
423 fn used_crate_source(&self, cnum: ast::CrateNum) -> CrateSource { unimplemented!() }
424 fn extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<ast::CrateNum> { None }
425 fn encode_metadata(&self,
426 tcx: &ty::ctxt<'tcx>,
427 reexports: &def::ExportMap,
428 item_symbols: &RefCell<NodeMap<String>>,
429 link_meta: &LinkMeta,
431 mir_map: &NodeMap<Mir<'tcx>>,
432 krate: &hir::Crate) -> Vec<u8> { vec![] }
433 fn metadata_encoding_version(&self) -> &[u8] { unimplemented!() }
437 /// Metadata encoding and decoding can make use of thread-local encoding and
438 /// decoding contexts. These allow implementers of serialize::Encodable and
439 /// Decodable to access information and datastructures that would otherwise not
440 /// be available to them. For example, we can automatically translate def-id and
441 /// span information during decoding because the decoding context knows which
442 /// crate the data is decoded from. Or it allows to make ty::Ty decodable
443 /// because the context has access to the ty::ctxt that is needed for creating
444 /// ty::Ty instances.
446 /// Note, however, that this only works for RBML-based encoding and decoding at
449 use rbml::opaque::Encoder as OpaqueEncoder;
450 use rbml::opaque::Decoder as OpaqueDecoder;
453 use middle::ty::{self, Ty};
454 use middle::subst::Substs;
455 use middle::def_id::DefId;
457 pub trait EncodingContext<'tcx> {
458 fn tcx<'a>(&'a self) -> &'a ty::ctxt<'tcx>;
459 fn encode_ty(&self, encoder: &mut OpaqueEncoder, t: Ty<'tcx>);
460 fn encode_substs(&self, encoder: &mut OpaqueEncoder, substs: &Substs<'tcx>);
463 /// Marker type used for the scoped TLS slot.
464 /// The type context cannot be used directly because the scoped TLS
465 /// in libstd doesn't allow types generic over lifetimes.
468 scoped_thread_local!(static TLS_ENCODING: TlsPayload);
470 /// Execute f after pushing the given EncodingContext onto the TLS stack.
471 pub fn enter_encoding_context<'tcx, F, R>(ecx: &EncodingContext<'tcx>,
472 encoder: &mut OpaqueEncoder,
474 where F: FnOnce(&EncodingContext<'tcx>, &mut OpaqueEncoder) -> R
476 let tls_payload = (ecx as *const _, encoder as *mut _);
477 let tls_ptr = &tls_payload as *const _ as *const TlsPayload;
478 TLS_ENCODING.set(unsafe { &*tls_ptr }, || f(ecx, encoder))
481 /// Execute f with access to the thread-local encoding context and
482 /// rbml encoder. This function will panic if the encoder passed in and the
483 /// context encoder are not the same.
485 /// Note that this method is 'practically' safe due to its checking that the
486 /// encoder passed in is the same as the one in TLS, but it would still be
487 /// possible to construct cases where the EncodingContext is exchanged
488 /// while the same encoder is used, thus working with a wrong context.
489 pub fn with_encoding_context<'tcx, E, F, R>(encoder: &mut E, f: F) -> R
490 where F: FnOnce(&EncodingContext<'tcx>, &mut OpaqueEncoder) -> R,
491 E: serialize::Encoder
494 unsafe_with_encoding_context(|ecx, tls_encoder| {
495 assert!(encoder as *mut _ as usize == tls_encoder as *mut _ as usize);
497 let ecx: &EncodingContext<'tcx> = mem::transmute(ecx);
504 /// Execute f with access to the thread-local encoding context and
506 pub unsafe fn unsafe_with_encoding_context<F, R>(f: F) -> R
507 where F: FnOnce(&EncodingContext, &mut OpaqueEncoder) -> R
509 TLS_ENCODING.with(|tls| {
510 let tls_payload = (tls as *const TlsPayload)
511 as *mut (&EncodingContext, &mut OpaqueEncoder);
512 f((*tls_payload).0, (*tls_payload).1)
516 pub trait DecodingContext<'tcx> {
517 fn tcx<'a>(&'a self) -> &'a ty::ctxt<'tcx>;
518 fn decode_ty(&self, decoder: &mut OpaqueDecoder) -> ty::Ty<'tcx>;
519 fn decode_substs(&self, decoder: &mut OpaqueDecoder) -> Substs<'tcx>;
520 fn translate_def_id(&self, def_id: DefId) -> DefId;
523 scoped_thread_local!(static TLS_DECODING: TlsPayload);
525 /// Execute f after pushing the given DecodingContext onto the TLS stack.
526 pub fn enter_decoding_context<'tcx, F, R>(dcx: &DecodingContext<'tcx>,
527 decoder: &mut OpaqueDecoder,
529 where F: FnOnce(&DecodingContext<'tcx>, &mut OpaqueDecoder) -> R
531 let tls_payload = (dcx as *const _, decoder as *mut _);
532 let tls_ptr = &tls_payload as *const _ as *const TlsPayload;
533 TLS_DECODING.set(unsafe { &*tls_ptr }, || f(dcx, decoder))
536 /// Execute f with access to the thread-local decoding context and
537 /// rbml decoder. This function will panic if the decoder passed in and the
538 /// context decoder are not the same.
540 /// Note that this method is 'practically' safe due to its checking that the
541 /// decoder passed in is the same as the one in TLS, but it would still be
542 /// possible to construct cases where the DecodingContext is exchanged
543 /// while the same decoder is used, thus working with a wrong context.
544 pub fn with_decoding_context<'decoder, 'tcx, D, F, R>(d: &'decoder mut D, f: F) -> R
545 where D: serialize::Decoder,
546 F: FnOnce(&DecodingContext<'tcx>,
547 &mut OpaqueDecoder) -> R,
551 unsafe_with_decoding_context(|dcx, decoder| {
552 assert!((d as *mut _ as usize) == (decoder as *mut _ as usize));
554 let dcx: &DecodingContext<'tcx> = mem::transmute(dcx);
561 /// Execute f with access to the thread-local decoding context and
563 pub unsafe fn unsafe_with_decoding_context<F, R>(f: F) -> R
564 where F: FnOnce(&DecodingContext, &mut OpaqueDecoder) -> R
566 TLS_DECODING.with(|tls| {
567 let tls_payload = (tls as *const TlsPayload)
568 as *mut (&DecodingContext, &mut OpaqueDecoder);
569 f((*tls_payload).0, (*tls_payload).1)