Rollup merge of rust-lang#68554 - cjgillot:lang_items, r=Zoxc

Split lang_items to crates `rustc_hir` and `rustc_passes`.

As discussed in comment rust-lang#67688 (comment)

Author: JohnTitor

Cargo.lock

@@ -3630,6 +3630,7 @@ version = "0.0.0"
 name = "rustc_hir"
 version = "0.0.0"
 dependencies = [
+ "lazy_static 1.4.0",
  "rustc_ast_pretty",
  "rustc_data_structures",
  "rustc_errors",

src/librustc/hir/mod.rs

@@ -2,7 +2,6 @@
 //!
 //! [rustc guide]: https://rust-lang.github.io/rustc-guide/hir.html
 
-pub mod check_attr;
 pub mod exports;
 pub mod map;
 

src/librustc/ich/impls_hir.rs

@@ -251,12 +251,6 @@ impl<'a> ToStableHashKey<StableHashingContext<'a>> for hir::def_id::DefIndex {
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>> for crate::middle::lang_items::LangItem {
-    fn hash_stable(&self, _: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        ::std::hash::Hash::hash(self, hasher);
-    }
-}
-
 impl<'a> HashStable<StableHashingContext<'a>> for hir::TraitCandidate {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| {

src/librustc/macros.rs

@@ -1,40 +1,3 @@
-macro_rules! enum_from_u32 {
-    ($(#[$attr:meta])* pub enum $name:ident {
-        $($variant:ident = $e:expr,)*
-    }) => {
-        $(#[$attr])*
-        pub enum $name {
-            $($variant = $e),*
-        }
-
-        impl $name {
-            pub fn from_u32(u: u32) -> Option<$name> {
-                $(if u == $name::$variant as u32 {
-                    return Some($name::$variant)
-                })*
-                None
-            }
-        }
-    };
-    ($(#[$attr:meta])* pub enum $name:ident {
-        $($variant:ident,)*
-    }) => {
-        $(#[$attr])*
-        pub enum $name {
-            $($variant,)*
-        }
-
-        impl $name {
-            pub fn from_u32(u: u32) -> Option<$name> {
-                $(if u == $name::$variant as u32 {
-                    return Some($name::$variant)
-                })*
-                None
-            }
-        }
-    }
-}
-
 #[macro_export]
 macro_rules! bug {
     () => ( bug!("impossible case reached") );

src/librustc/middle/lang_items.rs

@@ -33,4 +33,3 @@ pub mod recursion_limit;
 pub mod region;
 pub mod resolve_lifetime;
 pub mod stability;
-pub mod weak_lang_items;

src/librustc/middle/mod.rs

@@ -1634,7 +1634,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &TraitObligation<'tcx>,
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) -> Result<(), SelectionError<'tcx>> {
-        let kind = match self.tcx().lang_items().fn_trait_kind(obligation.predicate.def_id()) {
+        let kind = match self.tcx().fn_trait_kind_from_lang_item(obligation.predicate.def_id()) {
             Some(k) => k,
             None => {
                 return Ok(());
@@ -1677,7 +1677,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) -> Result<(), SelectionError<'tcx>> {
         // We provide impl of all fn traits for fn pointers.
-        if self.tcx().lang_items().fn_trait_kind(obligation.predicate.def_id()).is_none() {
+        if self.tcx().fn_trait_kind_from_lang_item(obligation.predicate.def_id()).is_none() {
             return Ok(());
         }
 
@@ -2889,8 +2889,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
         let kind = self
             .tcx()
-            .lang_items()
-            .fn_trait_kind(obligation.predicate.def_id())
+            .fn_trait_kind_from_lang_item(obligation.predicate.def_id())
             .unwrap_or_else(|| bug!("closure candidate for non-fn trait {:?}", obligation));
 
         // Okay to skip binder because the substs on closure types never

src/librustc/middle/weak_lang_items.rs

@@ -2716,10 +2716,6 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
         assert_eq!(id, LOCAL_CRATE);
         tcx.crate_name
     };
-    providers.get_lang_items = |tcx, id| {
-        assert_eq!(id, LOCAL_CRATE);
-        tcx.arena.alloc(middle::lang_items::collect(tcx))
-    };
     providers.maybe_unused_trait_import = |tcx, id| tcx.maybe_unused_trait_imports.contains(&id);
     providers.maybe_unused_extern_crates = |tcx, cnum| {
         assert_eq!(cnum, LOCAL_CRATE);

src/librustc/traits/select.rs

@@ -450,7 +450,7 @@ fn resolve_associated_item<'tcx>(
             substs: generator_data.substs,
         }),
         traits::VtableClosure(closure_data) => {
-            let trait_closure_kind = tcx.lang_items().fn_trait_kind(trait_id).unwrap();
+            let trait_closure_kind = tcx.fn_trait_kind_from_lang_item(trait_id).unwrap();
             Some(Instance::resolve_closure(
                 tcx,
                 closure_data.closure_def_id,