src/librustc_metadata/cstore_impl.rs - third_party/rust - Git at Google

 use crate::cstore::{self, LoadedMacro};
 use crate::encoder;
 use crate::link_args;
 use crate::native_libs;
 use crate::foreign_modules;
 use crate::schema;

 use rustc::ty::query::QueryConfig;
 use rustc::middle::cstore::{CrateStore, DepKind,
                             EncodedMetadata, NativeLibraryKind};
 use rustc::middle::exported_symbols::ExportedSymbol;
 use rustc::middle::stability::DeprecationEntry;
 use rustc::hir::def;
 use rustc::hir;
 use rustc::session::{CrateDisambiguator, Session};
 use rustc::ty::{self, TyCtxt};
 use rustc::ty::query::Providers;
 use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE, CRATE_DEF_INDEX};
 use rustc::hir::map::{DefKey, DefPath, DefPathHash};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc::util::nodemap::DefIdMap;
 use rustc_data_structures::svh::Svh;

 use smallvec::SmallVec;
 use std::any::Any;
 use rustc_data_structures::sync::Lrc;
 use std::sync::Arc;

 use syntax::ast;
 use syntax::attr;
 use syntax::source_map;
 use syntax::edition::Edition;
 use syntax::parse::source_file_to_stream;
 use syntax::parse::parser::emit_unclosed_delims;
 use syntax::symbol::Symbol;
 use syntax_pos::{Span, FileName};
 use rustc_data_structures::bit_set::BitSet;

 macro_rules! provide {
     (<$lt:tt> $tcx:ident, $def_id:ident, $other:ident, $cdata:ident,
       $($name:ident => $compute:block)*) => {
         pub fn provide_extern<$lt>(providers: &mut Providers<$lt>) {
             // HACK(eddyb) `$lt: $lt` forces `$lt` to be early-bound, which
             // allows the associated type in the return type to be normalized.
             $(fn $name<$lt: $lt, T: IntoArgs>(
                 $tcx: TyCtxt<$lt>,
                 def_id_arg: T,
             ) -> <ty::queries::$name<$lt> as QueryConfig<$lt>>::Value {
                 #[allow(unused_variables)]
                 let ($def_id, $other) = def_id_arg.into_args();
                 assert!(!$def_id.is_local());

                 let def_path_hash = $tcx.def_path_hash(DefId {
                     krate: $def_id.krate,
                     index: CRATE_DEF_INDEX
                 });
                 let dep_node = def_path_hash
                     .to_dep_node(rustc::dep_graph::DepKind::CrateMetadata);
                 // The DepNodeIndex of the DepNode::CrateMetadata should be
                 // cached somewhere, so that we can use read_index().
                 $tcx.dep_graph.read(dep_node);

                 let $cdata = $tcx.crate_data_as_rc_any($def_id.krate);
                 let $cdata = $cdata.downcast_ref::<cstore::CrateMetadata>()
                     .expect("CrateStore created data is not a CrateMetadata");
                 $compute
             })*

             *providers = Providers {
                 $($name,)*
                 ..*providers
             };
         }
     }
 }

 // small trait to work around different signature queries all being defined via
 // the macro above.
 trait IntoArgs {
     fn into_args(self) -> (DefId, DefId);
 }

 impl IntoArgs for DefId {
     fn into_args(self) -> (DefId, DefId) { (self, self) }
 }

 impl IntoArgs for CrateNum {
     fn into_args(self) -> (DefId, DefId) { (self.as_def_id(), self.as_def_id()) }
 }

 impl IntoArgs for (CrateNum, DefId) {
     fn into_args(self) -> (DefId, DefId) { (self.0.as_def_id(), self.1) }
 }

 provide! { <'tcx> tcx, def_id, other, cdata,
     type_of => { cdata.get_type(def_id.index, tcx) }
     generics_of => {
         tcx.arena.alloc(cdata.get_generics(def_id.index, tcx.sess))
     }
     predicates_of => { tcx.arena.alloc(cdata.get_predicates(def_id.index, tcx)) }
     predicates_defined_on => {
         tcx.arena.alloc(cdata.get_predicates_defined_on(def_id.index, tcx))
     }
     super_predicates_of => { tcx.arena.alloc(cdata.get_super_predicates(def_id.index, tcx)) }
     trait_def => {
         tcx.arena.alloc(cdata.get_trait_def(def_id.index, tcx.sess))
     }
     adt_def => { cdata.get_adt_def(def_id.index, tcx) }
     adt_destructor => {
         let _ = cdata;
         tcx.calculate_dtor(def_id, &mut |_,_| Ok(()))
     }
     variances_of => { tcx.arena.alloc_from_iter(cdata.get_item_variances(def_id.index)) }
     associated_item_def_ids => {
         let mut result = SmallVec::<[_; 8]>::new();
         cdata.each_child_of_item(def_id.index,
           |child| result.push(child.res.def_id()), tcx.sess);
         tcx.arena.alloc_slice(&result)
     }
     associated_item => { cdata.get_associated_item(def_id.index) }
     impl_trait_ref => { cdata.get_impl_trait(def_id.index, tcx) }
     impl_polarity => { cdata.get_impl_polarity(def_id.index) }
     coerce_unsized_info => {
         cdata.get_coerce_unsized_info(def_id.index).unwrap_or_else(|| {
             bug!("coerce_unsized_info: `{:?}` is missing its info", def_id);
         })
     }
     optimized_mir => { tcx.arena.alloc(cdata.get_optimized_mir(tcx, def_id.index)) }
     promoted_mir => { tcx.arena.alloc(cdata.get_promoted_mir(tcx, def_id.index)) }
     mir_const_qualif => {
         (cdata.mir_const_qualif(def_id.index), tcx.arena.alloc(BitSet::new_empty(0)))
     }
     fn_sig => { cdata.fn_sig(def_id.index, tcx) }
     inherent_impls => { cdata.get_inherent_implementations_for_type(tcx, def_id.index) }
     is_const_fn_raw => { cdata.is_const_fn_raw(def_id.index) }
     is_foreign_item => { cdata.is_foreign_item(def_id.index) }
     static_mutability => { cdata.static_mutability(def_id.index) }
     def_kind => { cdata.def_kind(def_id.index) }
     def_span => { cdata.get_span(def_id.index, &tcx.sess) }
     lookup_stability => {
         cdata.get_stability(def_id.index).map(|s| tcx.intern_stability(s))
     }
     lookup_deprecation_entry => {
         cdata.get_deprecation(def_id.index).map(DeprecationEntry::external)
     }
     item_attrs => { cdata.get_item_attrs(def_id.index, tcx.sess) }
     // FIXME(#38501) We've skipped a `read` on the `HirBody` of
     // a `fn` when encoding, so the dep-tracking wouldn't work.
     // This is only used by rustdoc anyway, which shouldn't have
     // incremental recompilation ever enabled.
     fn_arg_names => { cdata.get_fn_param_names(def_id.index) }
     rendered_const => { cdata.get_rendered_const(def_id.index) }
     impl_parent => { cdata.get_parent_impl(def_id.index) }
     trait_of_item => { cdata.get_trait_of_item(def_id.index) }
     const_is_rvalue_promotable_to_static => {
         cdata.const_is_rvalue_promotable_to_static(def_id.index)
     }
     is_mir_available => { cdata.is_item_mir_available(def_id.index) }

     dylib_dependency_formats => { cdata.get_dylib_dependency_formats(tcx) }
     is_panic_runtime => { cdata.root.panic_runtime }
     is_compiler_builtins => { cdata.root.compiler_builtins }
     has_global_allocator => { cdata.root.has_global_allocator }
     has_panic_handler => { cdata.root.has_panic_handler }
     is_sanitizer_runtime => { cdata.root.sanitizer_runtime }
     is_profiler_runtime => { cdata.root.profiler_runtime }
     panic_strategy => { cdata.root.panic_strategy }
     extern_crate => {
         let r = *cdata.extern_crate.lock();
         r.map(|c| &*tcx.arena.alloc(c))
     }
     is_no_builtins => { cdata.root.no_builtins }
     symbol_mangling_version => { cdata.root.symbol_mangling_version }
     impl_defaultness => { cdata.get_impl_defaultness(def_id.index) }
     reachable_non_generics => {
         let reachable_non_generics = tcx
             .exported_symbols(cdata.cnum)
             .iter()
             .filter_map(|&(exported_symbol, export_level)| {
                 if let ExportedSymbol::NonGeneric(def_id) = exported_symbol {
                     return Some((def_id, export_level))
                 } else {
                     None
                 }
             })
             .collect();

         tcx.arena.alloc(reachable_non_generics)
     }
     native_libraries => { Lrc::new(cdata.get_native_libraries(tcx.sess)) }
     foreign_modules => { cdata.get_foreign_modules(tcx) }
     plugin_registrar_fn => {
         cdata.root.plugin_registrar_fn.map(|index| {
             DefId { krate: def_id.krate, index }
         })
     }
     proc_macro_decls_static => {
         cdata.root.proc_macro_decls_static.map(|index| {
             DefId { krate: def_id.krate, index }
         })
     }
     crate_disambiguator => { cdata.root.disambiguator }
     crate_hash => { cdata.root.hash }
     original_crate_name => { cdata.root.name }

     extra_filename => { cdata.root.extra_filename.clone() }

     implementations_of_trait => {
         cdata.get_implementations_for_trait(tcx, Some(other))
     }

     all_trait_implementations => {
         cdata.get_implementations_for_trait(tcx, None)
     }

     visibility => { cdata.get_visibility(def_id.index) }
     dep_kind => {
         let r = *cdata.dep_kind.lock();
         r
     }
     crate_name => { cdata.name }
     item_children => {
         let mut result = SmallVec::<[_; 8]>::new();
         cdata.each_child_of_item(def_id.index, |child| result.push(child), tcx.sess);
         tcx.arena.alloc_slice(&result)
     }
     defined_lib_features => { cdata.get_lib_features(tcx) }
     defined_lang_items => { cdata.get_lang_items(tcx) }
     diagnostic_items => { cdata.get_diagnostic_items(tcx) }
     missing_lang_items => { cdata.get_missing_lang_items(tcx) }

     missing_extern_crate_item => {
         let r = match *cdata.extern_crate.borrow() {
             Some(extern_crate) if !extern_crate.direct => true,
             _ => false,
         };
         r
     }

     used_crate_source => { Lrc::new(cdata.source.clone()) }

     exported_symbols => { Arc::new(cdata.exported_symbols(tcx)) }
 }

 pub fn provide(providers: &mut Providers<'_>) {
     // FIXME(#44234) - almost all of these queries have no sub-queries and
     // therefore no actual inputs, they're just reading tables calculated in
     // resolve! Does this work? Unsure! That's what the issue is about
     *providers = Providers {
         is_dllimport_foreign_item: |tcx, id| {
             tcx.native_library_kind(id) == Some(NativeLibraryKind::NativeUnknown)
         },
         is_statically_included_foreign_item: |tcx, id| {
             match tcx.native_library_kind(id) {
                 Some(NativeLibraryKind::NativeStatic) |
                 Some(NativeLibraryKind::NativeStaticNobundle) => true,
                 _ => false,
             }
         },
         native_library_kind: |tcx, id| {
             tcx.native_libraries(id.krate)
                 .iter()
                 .filter(|lib| native_libs::relevant_lib(&tcx.sess, lib))
                 .find(|lib| {
                     let fm_id = match lib.foreign_module {
                         Some(id) => id,
                         None => return false,
                     };
                     tcx.foreign_modules(id.krate)
                         .iter()
                         .find(|m| m.def_id == fm_id)
                         .expect("failed to find foreign module")
                         .foreign_items
                         .contains(&id)
                 })
                 .map(|l| l.kind)
         },
         native_libraries: |tcx, cnum| {
             assert_eq!(cnum, LOCAL_CRATE);
             Lrc::new(native_libs::collect(tcx))
         },
         foreign_modules: |tcx, cnum| {
             assert_eq!(cnum, LOCAL_CRATE);
             &tcx.arena.alloc(foreign_modules::collect(tcx))[..]
         },
         link_args: |tcx, cnum| {
             assert_eq!(cnum, LOCAL_CRATE);
             Lrc::new(link_args::collect(tcx))
         },

         // Returns a map from a sufficiently visible external item (i.e., an
         // external item that is visible from at least one local module) to a
         // sufficiently visible parent (considering modules that re-export the
         // external item to be parents).
         visible_parent_map: |tcx, cnum| {
             use std::collections::vec_deque::VecDeque;
             use std::collections::hash_map::Entry;

             assert_eq!(cnum, LOCAL_CRATE);
             let mut visible_parent_map: DefIdMap<DefId> = Default::default();

             // Issue 46112: We want the map to prefer the shortest
             // paths when reporting the path to an item. Therefore we
             // build up the map via a breadth-first search (BFS),
             // which naturally yields minimal-length paths.
             //
             // Note that it needs to be a BFS over the whole forest of
             // crates, not just each individual crate; otherwise you
             // only get paths that are locally minimal with respect to
             // whatever crate we happened to encounter first in this
             // traversal, but not globally minimal across all crates.
             let bfs_queue = &mut VecDeque::new();

             // Preferring shortest paths alone does not guarantee a
             // deterministic result; so sort by crate num to avoid
             // hashtable iteration non-determinism. This only makes
             // things as deterministic as crate-nums assignment is,
             // which is to say, its not deterministic in general. But
             // we believe that libstd is consistently assigned crate
             // num 1, so it should be enough to resolve #46112.
             let mut crates: Vec<CrateNum> = (*tcx.crates()).to_owned();
             crates.sort();

             for &cnum in crates.iter() {
                 // Ignore crates without a corresponding local `extern crate` item.
                 if tcx.missing_extern_crate_item(cnum) {
                     continue
                 }

                 bfs_queue.push_back(DefId {
                     krate: cnum,
                     index: CRATE_DEF_INDEX
                 });
             }

             // (restrict scope of mutable-borrow of `visible_parent_map`)
             {
                 let visible_parent_map = &mut visible_parent_map;
                 let mut add_child = |bfs_queue: &mut VecDeque<_>,
                                      child: &def::Export<hir::HirId>,
                                      parent: DefId| {
                     if child.vis != ty::Visibility::Public {
                         return;
                     }

                     if let Some(child) = child.res.opt_def_id() {
                         match visible_parent_map.entry(child) {
                             Entry::Occupied(mut entry) => {
                                 // If `child` is defined in crate `cnum`, ensure
                                 // that it is mapped to a parent in `cnum`.
                                 if child.krate == cnum && entry.get().krate != cnum {
                                     entry.insert(parent);
                                 }
                             }
                             Entry::Vacant(entry) => {
                                 entry.insert(parent);
                                 bfs_queue.push_back(child);
                             }
                         }
                     }
                 };

                 while let Some(def) = bfs_queue.pop_front() {
                     for child in tcx.item_children(def).iter() {
                         add_child(bfs_queue, child, def);
                     }
                 }
             }

             tcx.arena.alloc(visible_parent_map)
         },

         ..*providers
     };
 }

 impl cstore::CStore {
     pub fn export_macros_untracked(&self, cnum: CrateNum) {
         let data = self.get_crate_data(cnum);
         let mut dep_kind = data.dep_kind.lock();
         if *dep_kind == DepKind::UnexportedMacrosOnly {
             *dep_kind = DepKind::MacrosOnly;
         }
     }

     pub fn dep_kind_untracked(&self, cnum: CrateNum) -> DepKind {
         let data = self.get_crate_data(cnum);
         let r = *data.dep_kind.lock();
         r
     }

     pub fn crate_edition_untracked(&self, cnum: CrateNum) -> Edition {
         self.get_crate_data(cnum).root.edition
     }

     pub fn struct_field_names_untracked(&self, def: DefId) -> Vec<ast::Name> {
         self.get_crate_data(def.krate).get_struct_field_names(def.index)
     }

     pub fn ctor_kind_untracked(&self, def: DefId) -> def::CtorKind {
         self.get_crate_data(def.krate).get_ctor_kind(def.index)
     }

     pub fn item_attrs_untracked(&self, def: DefId, sess: &Session) -> Lrc<[ast::Attribute]> {
         self.get_crate_data(def.krate).get_item_attrs(def.index, sess)
     }

     pub fn item_children_untracked(
         &self,
         def_id: DefId,
         sess: &Session
     ) -> Vec<def::Export<hir::HirId>> {
         let mut result = vec![];
         self.get_crate_data(def_id.krate)
             .each_child_of_item(def_id.index, |child| result.push(child), sess);
         result
     }

     pub fn load_macro_untracked(&self, id: DefId, sess: &Session) -> LoadedMacro {
         let data = self.get_crate_data(id.krate);
         if data.is_proc_macro_crate() {
             return LoadedMacro::ProcMacro(data.load_proc_macro(id.index, sess));
         }

         let def = data.get_macro(id.index);
         let macro_full_name = data.def_path(id.index)
             .to_string_friendly(|_| data.imported_name);
         let source_name = FileName::Macros(macro_full_name);

         let source_file = sess.parse_sess.source_map().new_source_file(source_name, def.body);
         let local_span = Span::with_root_ctxt(source_file.start_pos, source_file.end_pos);
         let (body, mut errors) = source_file_to_stream(&sess.parse_sess, source_file, None);
         emit_unclosed_delims(&mut errors, &sess.diagnostic());

         // Mark the attrs as used
         let attrs = data.get_item_attrs(id.index, sess);
         for attr in attrs.iter() {
             attr::mark_used(attr);
         }

         let name = data.def_key(id.index).disambiguated_data.data
             .get_opt_name().expect("no name in load_macro");
         sess.imported_macro_spans.borrow_mut()
             .insert(local_span, (name.to_string(), data.get_span(id.index, sess)));

         LoadedMacro::MacroDef(ast::Item {
             ident: ast::Ident::from_str(&name.as_str()),
             id: ast::DUMMY_NODE_ID,
             span: local_span,
             attrs: attrs.iter().cloned().collect(),
             node: ast::ItemKind::MacroDef(ast::MacroDef {
                 tokens: body.into(),
                 legacy: def.legacy,
             }),
             vis: source_map::respan(local_span.shrink_to_lo(), ast::VisibilityKind::Inherited),
             tokens: None,
         })
     }

     pub fn associated_item_cloned_untracked(&self, def: DefId) -> ty::AssocItem {
         self.get_crate_data(def.krate).get_associated_item(def.index)
     }
 }

 impl CrateStore for cstore::CStore {
     fn crate_data_as_rc_any(&self, krate: CrateNum) -> Lrc<dyn Any> {
         self.get_crate_data(krate)
     }

     fn item_generics_cloned_untracked(&self, def: DefId, sess: &Session) -> ty::Generics {
         self.get_crate_data(def.krate).get_generics(def.index, sess)
     }

     fn crate_name_untracked(&self, cnum: CrateNum) -> Symbol
     {
         self.get_crate_data(cnum).name
     }

     fn crate_is_private_dep_untracked(&self, cnum: CrateNum) -> bool {
         self.get_crate_data(cnum).private_dep
     }

     fn crate_disambiguator_untracked(&self, cnum: CrateNum) -> CrateDisambiguator
     {
         self.get_crate_data(cnum).root.disambiguator
     }

     fn crate_hash_untracked(&self, cnum: CrateNum) -> Svh
     {
         self.get_crate_data(cnum).root.hash
     }

     /// Returns the `DefKey` for a given `DefId`. This indicates the
     /// parent `DefId` as well as some idea of what kind of data the
     /// `DefId` refers to.
     fn def_key(&self, def: DefId) -> DefKey {
         // Note: loading the def-key (or def-path) for a def-id is not
         // a *read* of its metadata. This is because the def-id is
         // really just an interned shorthand for a def-path, which is the
         // canonical name for an item.
         //
         // self.dep_graph.read(DepNode::MetaData(def));
         self.get_crate_data(def.krate).def_key(def.index)
     }

     fn def_path(&self, def: DefId) -> DefPath {
         // See `Note` above in `def_key()` for why this read is
         // commented out:
         //
         // self.dep_graph.read(DepNode::MetaData(def));
         self.get_crate_data(def.krate).def_path(def.index)
     }

     fn def_path_hash(&self, def: DefId) -> DefPathHash {
         self.get_crate_data(def.krate).def_path_hash(def.index)
     }

     fn def_path_table(&self, cnum: CrateNum) -> Lrc<DefPathTable> {
         self.get_crate_data(cnum).def_path_table.clone()
     }

     fn crates_untracked(&self) -> Vec<CrateNum>
     {
         let mut result = vec![];
         self.iter_crate_data(|cnum, _| result.push(cnum));
         result
     }

     fn extern_mod_stmt_cnum_untracked(&self, emod_id: ast::NodeId) -> Option<CrateNum>
     {
         self.do_extern_mod_stmt_cnum(emod_id)
     }

     fn postorder_cnums_untracked(&self) -> Vec<CrateNum> {
         self.do_postorder_cnums_untracked()
     }

     fn encode_metadata(&self, tcx: TyCtxt<'_>) -> EncodedMetadata {
         encoder::encode_metadata(tcx)
     }

     fn metadata_encoding_version(&self) -> &[u8]
     {
         schema::METADATA_HEADER
     }
 }
	use crate::cstore::{self, LoadedMacro};
	use crate::encoder;
	use crate::link_args;
	use crate::native_libs;
	use crate::foreign_modules;
	use crate::schema;

	use rustc::ty::query::QueryConfig;
	use rustc::middle::cstore::{CrateStore, DepKind,
	EncodedMetadata, NativeLibraryKind};
	use rustc::middle::exported_symbols::ExportedSymbol;
	use rustc::middle::stability::DeprecationEntry;
	use rustc::hir::def;
	use rustc::hir;
	use rustc::session::{CrateDisambiguator, Session};
	use rustc::ty::{self, TyCtxt};
	use rustc::ty::query::Providers;
	use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE, CRATE_DEF_INDEX};
	use rustc::hir::map::{DefKey, DefPath, DefPathHash};
	use rustc::hir::map::definitions::DefPathTable;
	use rustc::util::nodemap::DefIdMap;
	use rustc_data_structures::svh::Svh;

	use smallvec::SmallVec;
	use std::any::Any;
	use rustc_data_structures::sync::Lrc;
	use std::sync::Arc;

	use syntax::ast;
	use syntax::attr;
	use syntax::source_map;
	use syntax::edition::Edition;
	use syntax::parse::source_file_to_stream;
	use syntax::parse::parser::emit_unclosed_delims;
	use syntax::symbol::Symbol;
	use syntax_pos::{Span, FileName};
	use rustc_data_structures::bit_set::BitSet;

	macro_rules! provide {
	(<$lt:tt> $tcx:ident, $def_id:ident, $other:ident, $cdata:ident,
	$($name:ident => $compute:block)*) => {
	pub fn provide_extern<$lt>(providers: &mut Providers<$lt>) {
	// HACK(eddyb) `$lt: $lt` forces `$lt` to be early-bound, which
	// allows the associated type in the return type to be normalized.
	$(fn $name<$lt: $lt, T: IntoArgs>(
	$tcx: TyCtxt<$lt>,
	def_id_arg: T,
	) -> <ty::queries::$name<$lt> as QueryConfig<$lt>>::Value {
	#[allow(unused_variables)]
	let ($def_id, $other) = def_id_arg.into_args();
	assert!(!$def_id.is_local());

	let def_path_hash = $tcx.def_path_hash(DefId {
	krate: $def_id.krate,
	index: CRATE_DEF_INDEX
	});
	let dep_node = def_path_hash
	.to_dep_node(rustc::dep_graph::DepKind::CrateMetadata);
	// The DepNodeIndex of the DepNode::CrateMetadata should be
	// cached somewhere, so that we can use read_index().
	$tcx.dep_graph.read(dep_node);

	let $cdata = $tcx.crate_data_as_rc_any($def_id.krate);
	let $cdata = $cdata.downcast_ref::<cstore::CrateMetadata>()
	.expect("CrateStore created data is not a CrateMetadata");
	$compute
	})*

	*providers = Providers {
	$($name,)*
	..*providers
	};
	}
	}
	}

	// small trait to work around different signature queries all being defined via
	// the macro above.
	trait IntoArgs {
	fn into_args(self) -> (DefId, DefId);
	}

	impl IntoArgs for DefId {
	fn into_args(self) -> (DefId, DefId) { (self, self) }
	}

	impl IntoArgs for CrateNum {
	fn into_args(self) -> (DefId, DefId) { (self.as_def_id(), self.as_def_id()) }
	}

	impl IntoArgs for (CrateNum, DefId) {
	fn into_args(self) -> (DefId, DefId) { (self.0.as_def_id(), self.1) }
	}

	provide! { <'tcx> tcx, def_id, other, cdata,
	type_of => { cdata.get_type(def_id.index, tcx) }
	generics_of => {
	tcx.arena.alloc(cdata.get_generics(def_id.index, tcx.sess))
	}
	predicates_of => { tcx.arena.alloc(cdata.get_predicates(def_id.index, tcx)) }
	predicates_defined_on => {
	tcx.arena.alloc(cdata.get_predicates_defined_on(def_id.index, tcx))
	}
	super_predicates_of => { tcx.arena.alloc(cdata.get_super_predicates(def_id.index, tcx)) }
	trait_def => {
	tcx.arena.alloc(cdata.get_trait_def(def_id.index, tcx.sess))
	}
	adt_def => { cdata.get_adt_def(def_id.index, tcx) }
	adt_destructor => {
	let _ = cdata;
	tcx.calculate_dtor(def_id, &mut \|_,_\| Ok(()))
	}
	variances_of => { tcx.arena.alloc_from_iter(cdata.get_item_variances(def_id.index)) }
	associated_item_def_ids => {
	let mut result = SmallVec::<[_; 8]>::new();
	cdata.each_child_of_item(def_id.index,
	\|child\| result.push(child.res.def_id()), tcx.sess);
	tcx.arena.alloc_slice(&result)
	}
	associated_item => { cdata.get_associated_item(def_id.index) }
	impl_trait_ref => { cdata.get_impl_trait(def_id.index, tcx) }
	impl_polarity => { cdata.get_impl_polarity(def_id.index) }
	coerce_unsized_info => {
	cdata.get_coerce_unsized_info(def_id.index).unwrap_or_else(\|\| {
	bug!("coerce_unsized_info: `{:?}` is missing its info", def_id);
	})
	}
	optimized_mir => { tcx.arena.alloc(cdata.get_optimized_mir(tcx, def_id.index)) }
	promoted_mir => { tcx.arena.alloc(cdata.get_promoted_mir(tcx, def_id.index)) }
	mir_const_qualif => {
	(cdata.mir_const_qualif(def_id.index), tcx.arena.alloc(BitSet::new_empty(0)))
	}
	fn_sig => { cdata.fn_sig(def_id.index, tcx) }
	inherent_impls => { cdata.get_inherent_implementations_for_type(tcx, def_id.index) }
	is_const_fn_raw => { cdata.is_const_fn_raw(def_id.index) }
	is_foreign_item => { cdata.is_foreign_item(def_id.index) }
	static_mutability => { cdata.static_mutability(def_id.index) }
	def_kind => { cdata.def_kind(def_id.index) }
	def_span => { cdata.get_span(def_id.index, &tcx.sess) }
	lookup_stability => {
	cdata.get_stability(def_id.index).map(\|s\| tcx.intern_stability(s))
	}
	lookup_deprecation_entry => {
	cdata.get_deprecation(def_id.index).map(DeprecationEntry::external)
	}
	item_attrs => { cdata.get_item_attrs(def_id.index, tcx.sess) }
	// FIXME(#38501) We've skipped a `read` on the `HirBody` of
	// a `fn` when encoding, so the dep-tracking wouldn't work.
	// This is only used by rustdoc anyway, which shouldn't have
	// incremental recompilation ever enabled.
	fn_arg_names => { cdata.get_fn_param_names(def_id.index) }
	rendered_const => { cdata.get_rendered_const(def_id.index) }
	impl_parent => { cdata.get_parent_impl(def_id.index) }
	trait_of_item => { cdata.get_trait_of_item(def_id.index) }
	const_is_rvalue_promotable_to_static => {
	cdata.const_is_rvalue_promotable_to_static(def_id.index)
	}
	is_mir_available => { cdata.is_item_mir_available(def_id.index) }

	dylib_dependency_formats => { cdata.get_dylib_dependency_formats(tcx) }
	is_panic_runtime => { cdata.root.panic_runtime }
	is_compiler_builtins => { cdata.root.compiler_builtins }
	has_global_allocator => { cdata.root.has_global_allocator }
	has_panic_handler => { cdata.root.has_panic_handler }
	is_sanitizer_runtime => { cdata.root.sanitizer_runtime }
	is_profiler_runtime => { cdata.root.profiler_runtime }
	panic_strategy => { cdata.root.panic_strategy }
	extern_crate => {
	let r = *cdata.extern_crate.lock();
	r.map(\|c\| &*tcx.arena.alloc(c))
	}
	is_no_builtins => { cdata.root.no_builtins }
	symbol_mangling_version => { cdata.root.symbol_mangling_version }
	impl_defaultness => { cdata.get_impl_defaultness(def_id.index) }
	reachable_non_generics => {
	let reachable_non_generics = tcx
	.exported_symbols(cdata.cnum)
	.iter()
	.filter_map(\|&(exported_symbol, export_level)\| {
	if let ExportedSymbol::NonGeneric(def_id) = exported_symbol {
	return Some((def_id, export_level))
	} else {
	None
	}
	})
	.collect();

	tcx.arena.alloc(reachable_non_generics)
	}
	native_libraries => { Lrc::new(cdata.get_native_libraries(tcx.sess)) }
	foreign_modules => { cdata.get_foreign_modules(tcx) }
	plugin_registrar_fn => {
	cdata.root.plugin_registrar_fn.map(\|index\| {
	DefId { krate: def_id.krate, index }
	})
	}
	proc_macro_decls_static => {
	cdata.root.proc_macro_decls_static.map(\|index\| {
	DefId { krate: def_id.krate, index }
	})
	}
	crate_disambiguator => { cdata.root.disambiguator }
	crate_hash => { cdata.root.hash }
	original_crate_name => { cdata.root.name }

	extra_filename => { cdata.root.extra_filename.clone() }

	implementations_of_trait => {
	cdata.get_implementations_for_trait(tcx, Some(other))
	}

	all_trait_implementations => {
	cdata.get_implementations_for_trait(tcx, None)
	}

	visibility => { cdata.get_visibility(def_id.index) }
	dep_kind => {
	let r = *cdata.dep_kind.lock();
	r
	}
	crate_name => { cdata.name }
	item_children => {
	let mut result = SmallVec::<[_; 8]>::new();
	cdata.each_child_of_item(def_id.index, \|child\| result.push(child), tcx.sess);
	tcx.arena.alloc_slice(&result)
	}
	defined_lib_features => { cdata.get_lib_features(tcx) }
	defined_lang_items => { cdata.get_lang_items(tcx) }
	diagnostic_items => { cdata.get_diagnostic_items(tcx) }
	missing_lang_items => { cdata.get_missing_lang_items(tcx) }

	missing_extern_crate_item => {
	let r = match *cdata.extern_crate.borrow() {
	Some(extern_crate) if !extern_crate.direct => true,
	_ => false,
	};
	r
	}

	used_crate_source => { Lrc::new(cdata.source.clone()) }

	exported_symbols => { Arc::new(cdata.exported_symbols(tcx)) }
	}

	pub fn provide(providers: &mut Providers<'_>) {
	// FIXME(#44234) - almost all of these queries have no sub-queries and
	// therefore no actual inputs, they're just reading tables calculated in
	// resolve! Does this work? Unsure! That's what the issue is about
	*providers = Providers {
	is_dllimport_foreign_item: \|tcx, id\| {
	tcx.native_library_kind(id) == Some(NativeLibraryKind::NativeUnknown)
	},
	is_statically_included_foreign_item: \|tcx, id\| {
	match tcx.native_library_kind(id) {
	Some(NativeLibraryKind::NativeStatic) \|
	Some(NativeLibraryKind::NativeStaticNobundle) => true,
	_ => false,
	}
	},
	native_library_kind: \|tcx, id\| {
	tcx.native_libraries(id.krate)
	.iter()
	.filter(\|lib\| native_libs::relevant_lib(&tcx.sess, lib))
	.find(\|lib\| {
	let fm_id = match lib.foreign_module {
	Some(id) => id,
	None => return false,
	};
	tcx.foreign_modules(id.krate)
	.iter()
	.find(\|m\| m.def_id == fm_id)
	.expect("failed to find foreign module")
	.foreign_items
	.contains(&id)
	})
	.map(\|l\| l.kind)
	},
	native_libraries: \|tcx, cnum\| {
	assert_eq!(cnum, LOCAL_CRATE);
	Lrc::new(native_libs::collect(tcx))
	},
	foreign_modules: \|tcx, cnum\| {
	assert_eq!(cnum, LOCAL_CRATE);
	&tcx.arena.alloc(foreign_modules::collect(tcx))[..]
	},
	link_args: \|tcx, cnum\| {
	assert_eq!(cnum, LOCAL_CRATE);
	Lrc::new(link_args::collect(tcx))
	},

	// Returns a map from a sufficiently visible external item (i.e., an
	// external item that is visible from at least one local module) to a
	// sufficiently visible parent (considering modules that re-export the
	// external item to be parents).
	visible_parent_map: \|tcx, cnum\| {
	use std::collections::vec_deque::VecDeque;
	use std::collections::hash_map::Entry;

	assert_eq!(cnum, LOCAL_CRATE);
	let mut visible_parent_map: DefIdMap<DefId> = Default::default();

	// Issue 46112: We want the map to prefer the shortest
	// paths when reporting the path to an item. Therefore we
	// build up the map via a breadth-first search (BFS),
	// which naturally yields minimal-length paths.
	//
	// Note that it needs to be a BFS over the whole forest of
	// crates, not just each individual crate; otherwise you
	// only get paths that are locally minimal with respect to
	// whatever crate we happened to encounter first in this
	// traversal, but not globally minimal across all crates.
	let bfs_queue = &mut VecDeque::new();

	// Preferring shortest paths alone does not guarantee a
	// deterministic result; so sort by crate num to avoid
	// hashtable iteration non-determinism. This only makes
	// things as deterministic as crate-nums assignment is,
	// which is to say, its not deterministic in general. But
	// we believe that libstd is consistently assigned crate
	// num 1, so it should be enough to resolve #46112.
	let mut crates: Vec<CrateNum> = (*tcx.crates()).to_owned();
	crates.sort();

	for &cnum in crates.iter() {
	// Ignore crates without a corresponding local `extern crate` item.
	if tcx.missing_extern_crate_item(cnum) {
	continue
	}

	bfs_queue.push_back(DefId {
	krate: cnum,
	index: CRATE_DEF_INDEX
	});
	}

	// (restrict scope of mutable-borrow of `visible_parent_map`)
	{
	let visible_parent_map = &mut visible_parent_map;
	let mut add_child = \|bfs_queue: &mut VecDeque<_>,
	child: &def::Export<hir::HirId>,
	parent: DefId\| {
	if child.vis != ty::Visibility::Public {
	return;
	}

	if let Some(child) = child.res.opt_def_id() {
	match visible_parent_map.entry(child) {
	Entry::Occupied(mut entry) => {
	// If `child` is defined in crate `cnum`, ensure
	// that it is mapped to a parent in `cnum`.
	if child.krate == cnum && entry.get().krate != cnum {
	entry.insert(parent);
	}
	}
	Entry::Vacant(entry) => {
	entry.insert(parent);
	bfs_queue.push_back(child);
	}
	}
	}
	};

	while let Some(def) = bfs_queue.pop_front() {
	for child in tcx.item_children(def).iter() {
	add_child(bfs_queue, child, def);
	}
	}
	}

	tcx.arena.alloc(visible_parent_map)
	},

	..*providers
	};
	}

	impl cstore::CStore {
	pub fn export_macros_untracked(&self, cnum: CrateNum) {
	let data = self.get_crate_data(cnum);
	let mut dep_kind = data.dep_kind.lock();
	if *dep_kind == DepKind::UnexportedMacrosOnly {
	*dep_kind = DepKind::MacrosOnly;
	}
	}

	pub fn dep_kind_untracked(&self, cnum: CrateNum) -> DepKind {
	let data = self.get_crate_data(cnum);
	let r = *data.dep_kind.lock();
	r
	}

	pub fn crate_edition_untracked(&self, cnum: CrateNum) -> Edition {
	self.get_crate_data(cnum).root.edition
	}

	pub fn struct_field_names_untracked(&self, def: DefId) -> Vec<ast::Name> {
	self.get_crate_data(def.krate).get_struct_field_names(def.index)
	}

	pub fn ctor_kind_untracked(&self, def: DefId) -> def::CtorKind {
	self.get_crate_data(def.krate).get_ctor_kind(def.index)
	}

	pub fn item_attrs_untracked(&self, def: DefId, sess: &Session) -> Lrc<[ast::Attribute]> {
	self.get_crate_data(def.krate).get_item_attrs(def.index, sess)
	}

	pub fn item_children_untracked(
	&self,
	def_id: DefId,
	sess: &Session
	) -> Vec<def::Export<hir::HirId>> {
	let mut result = vec![];
	self.get_crate_data(def_id.krate)
	.each_child_of_item(def_id.index, \|child\| result.push(child), sess);
	result
	}

	pub fn load_macro_untracked(&self, id: DefId, sess: &Session) -> LoadedMacro {
	let data = self.get_crate_data(id.krate);
	if data.is_proc_macro_crate() {
	return LoadedMacro::ProcMacro(data.load_proc_macro(id.index, sess));
	}

	let def = data.get_macro(id.index);
	let macro_full_name = data.def_path(id.index)
	.to_string_friendly(\|_\| data.imported_name);
	let source_name = FileName::Macros(macro_full_name);

	let source_file = sess.parse_sess.source_map().new_source_file(source_name, def.body);
	let local_span = Span::with_root_ctxt(source_file.start_pos, source_file.end_pos);
	let (body, mut errors) = source_file_to_stream(&sess.parse_sess, source_file, None);
	emit_unclosed_delims(&mut errors, &sess.diagnostic());

	// Mark the attrs as used
	let attrs = data.get_item_attrs(id.index, sess);
	for attr in attrs.iter() {
	attr::mark_used(attr);
	}

	let name = data.def_key(id.index).disambiguated_data.data
	.get_opt_name().expect("no name in load_macro");
	sess.imported_macro_spans.borrow_mut()
	.insert(local_span, (name.to_string(), data.get_span(id.index, sess)));

	LoadedMacro::MacroDef(ast::Item {
	ident: ast::Ident::from_str(&name.as_str()),
	id: ast::DUMMY_NODE_ID,
	span: local_span,
	attrs: attrs.iter().cloned().collect(),
	node: ast::ItemKind::MacroDef(ast::MacroDef {
	tokens: body.into(),
	legacy: def.legacy,
	}),
	vis: source_map::respan(local_span.shrink_to_lo(), ast::VisibilityKind::Inherited),
	tokens: None,
	})
	}

	pub fn associated_item_cloned_untracked(&self, def: DefId) -> ty::AssocItem {
	self.get_crate_data(def.krate).get_associated_item(def.index)
	}
	}

	impl CrateStore for cstore::CStore {
	fn crate_data_as_rc_any(&self, krate: CrateNum) -> Lrc<dyn Any> {
	self.get_crate_data(krate)
	}

	fn item_generics_cloned_untracked(&self, def: DefId, sess: &Session) -> ty::Generics {
	self.get_crate_data(def.krate).get_generics(def.index, sess)
	}

	fn crate_name_untracked(&self, cnum: CrateNum) -> Symbol
	{
	self.get_crate_data(cnum).name
	}

	fn crate_is_private_dep_untracked(&self, cnum: CrateNum) -> bool {
	self.get_crate_data(cnum).private_dep
	}

	fn crate_disambiguator_untracked(&self, cnum: CrateNum) -> CrateDisambiguator
	{
	self.get_crate_data(cnum).root.disambiguator
	}

	fn crate_hash_untracked(&self, cnum: CrateNum) -> Svh
	{
	self.get_crate_data(cnum).root.hash
	}

	/// Returns the `DefKey` for a given `DefId`. This indicates the
	/// parent `DefId` as well as some idea of what kind of data the
	/// `DefId` refers to.
	fn def_key(&self, def: DefId) -> DefKey {
	// Note: loading the def-key (or def-path) for a def-id is not
	// a read of its metadata. This is because the def-id is
	// really just an interned shorthand for a def-path, which is the
	// canonical name for an item.
	//
	// self.dep_graph.read(DepNode::MetaData(def));
	self.get_crate_data(def.krate).def_key(def.index)
	}

	fn def_path(&self, def: DefId) -> DefPath {
	// See `Note` above in `def_key()` for why this read is
	// commented out:
	//
	// self.dep_graph.read(DepNode::MetaData(def));
	self.get_crate_data(def.krate).def_path(def.index)
	}

	fn def_path_hash(&self, def: DefId) -> DefPathHash {
	self.get_crate_data(def.krate).def_path_hash(def.index)
	}

	fn def_path_table(&self, cnum: CrateNum) -> Lrc<DefPathTable> {
	self.get_crate_data(cnum).def_path_table.clone()
	}

	fn crates_untracked(&self) -> Vec<CrateNum>
	{
	let mut result = vec![];
	self.iter_crate_data(\|cnum, _\| result.push(cnum));
	result
	}

	fn extern_mod_stmt_cnum_untracked(&self, emod_id: ast::NodeId) -> Option<CrateNum>
	{
	self.do_extern_mod_stmt_cnum(emod_id)
	}

	fn postorder_cnums_untracked(&self) -> Vec<CrateNum> {
	self.do_postorder_cnums_untracked()
	}

	fn encode_metadata(&self, tcx: TyCtxt<'_>) -> EncodedMetadata {
	encoder::encode_metadata(tcx)
	}

	fn metadata_encoding_version(&self) -> &[u8]
	{
	schema::METADATA_HEADER
	}
	}