Rollup merge of rust-lang#103603 - camsteffen:refactor-lang, r=oli-obk

Lang item cleanups

Various cleanups related to lang items.

Author: Dylan-DPC

compiler/rustc_codegen_ssa/src/base.rs

@@ -22,7 +22,6 @@ use rustc_data_structures::sync::ParallelIterator;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::weak_lang_items::WEAK_ITEMS_SYMBOLS;
 use rustc_index::vec::Idx;
 use rustc_metadata::EncodedMetadata;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
@@ -887,14 +886,14 @@ impl CrateInfo {
         // by the compiler, but that's ok because all this stuff is unstable anyway.
         let target = &tcx.sess.target;
         if !are_upstream_rust_objects_already_included(tcx.sess) {
-            let missing_weak_lang_items: FxHashSet<&Symbol> = info
+            let missing_weak_lang_items: FxHashSet<Symbol> = info
                 .used_crates
                 .iter()
-                .flat_map(|cnum| {
-                    tcx.missing_lang_items(*cnum)
-                        .iter()
-                        .filter(|l| lang_items::required(tcx, **l))
-                        .filter_map(|item| WEAK_ITEMS_SYMBOLS.get(item))
+                .flat_map(|&cnum| tcx.missing_lang_items(cnum))
+                .filter(|l| l.is_weak())
+                .filter_map(|&l| {
+                    let name = l.link_name()?;
+                    lang_items::required(tcx, l).then_some(name)
                 })
                 .collect();
             let prefix = if target.is_like_windows && target.arch == "x86" { "_" } else { "" };

compiler/rustc_const_eval/src/util/call_kind.rs

@@ -3,7 +3,7 @@
 //! context.
 
 use rustc_hir::def_id::DefId;
-use rustc_hir::lang_items::LangItemGroup;
+use rustc_hir::lang_items;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AssocItemContainer, DefIdTree, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::Ident;
@@ -74,22 +74,24 @@ pub fn call_kind<'tcx>(
         }
     });
 
-    let fn_call = parent
-        .and_then(|p| tcx.lang_items().group(LangItemGroup::Fn).iter().find(|did| **did == p));
+    let fn_call = parent.and_then(|p| {
+        lang_items::FN_TRAITS.iter().filter_map(|&l| tcx.lang_items().get(l)).find(|&id| id == p)
+    });
 
-    let operator = (!from_hir_call)
-        .then(|| parent)
-        .flatten()
-        .and_then(|p| tcx.lang_items().group(LangItemGroup::Op).iter().find(|did| **did == p));
+    let operator = if !from_hir_call && let Some(p) = parent {
+        lang_items::OPERATORS.iter().filter_map(|&l| tcx.lang_items().get(l)).find(|&id| id == p)
+    } else {
+        None
+    };
 
     let is_deref = !from_hir_call && tcx.is_diagnostic_item(sym::deref_method, method_did);
 
     // Check for a 'special' use of 'self' -
     // an FnOnce call, an operator (e.g. `<<`), or a
     // deref coercion.
-    let kind = if let Some(&trait_id) = fn_call {
+    let kind = if let Some(trait_id) = fn_call {
         Some(CallKind::FnCall { fn_trait_id: trait_id, self_ty: method_substs.type_at(0) })
-    } else if let Some(&trait_id) = operator {
+    } else if let Some(trait_id) = operator {
         Some(CallKind::Operator { self_arg, trait_id, self_ty: method_substs.type_at(0) })
     } else if is_deref {
         let deref_target = tcx.get_diagnostic_item(sym::deref_target).and_then(|deref_target| {

compiler/rustc_error_messages/locales/en-US/monomorphize.ftl

@@ -21,6 +21,3 @@ monomorphize_large_assignments =
     moving {$size} bytes
     .label = value moved from here
     .note = The current maximum size is {$limit}, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
-
-monomorphize_requires_lang_item =
-    requires `{$lang_item}` lang_item

compiler/rustc_hir/src/lang_items.rs

@@ -5,10 +5,10 @@
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
 #![feature(const_btree_len)]
-#![feature(once_cell)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
+#![feature(variant_count)]
 #![recursion_limit = "256"]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_hir/src/lib.rs

@@ -1,53 +1,31 @@
 //! Validity checking for weak lang items
 
-use crate::def_id::DefId;
-use crate::{lang_items, LangItem, LanguageItems};
+use crate::LangItem;
 
-use rustc_ast as ast;
-use rustc_data_structures::fx::FxIndexMap;
 use rustc_span::symbol::{sym, Symbol};
 
-use std::sync::LazyLock;
-
 macro_rules! weak_lang_items {
-    ($($name:ident, $item:ident, $sym:ident;)*) => (
-
-pub static WEAK_ITEMS_REFS: LazyLock<FxIndexMap<Symbol, LangItem>> = LazyLock::new(|| {
-    let mut map = FxIndexMap::default();
-    $(map.insert(sym::$name, LangItem::$item);)*
-    map
-});
-
-pub static WEAK_ITEMS_SYMBOLS: LazyLock<FxIndexMap<LangItem, Symbol>> = LazyLock::new(|| {
-    let mut map = FxIndexMap::default();
-    $(map.insert(LangItem::$item, sym::$sym);)*
-    map
-});
-
-pub fn link_name(attrs: &[ast::Attribute]) -> Option<Symbol>
-{
-    lang_items::extract(attrs).and_then(|(name, _)| {
-        $(if name == sym::$name {
-            Some(sym::$sym)
-        } else)* {
-            None
+    ($($item:ident, $sym:ident;)*) => {
+        pub static WEAK_LANG_ITEMS: &[LangItem] = &[$(LangItem::$item,)*];
+
+        impl LangItem {
+            pub fn is_weak(self) -> bool {
+                matches!(self, $(LangItem::$item)|*)
+            }
+
+            pub fn link_name(self) -> Option<Symbol> {
+                match self {
+                    $( LangItem::$item => Some(sym::$sym),)*
+                    _ => None,
+                }
+            }
         }
-    })
-}
-
-impl LanguageItems {
-    pub fn is_weak_lang_item(&self, item_def_id: DefId) -> bool {
-        let did = Some(item_def_id);
-
-        $(self.$name() == did)||*
     }
 }
 
-) }
-
 weak_lang_items! {
-    panic_impl,         PanicImpl,          rust_begin_unwind;
-    eh_personality,     EhPersonality,      rust_eh_personality;
-    eh_catch_typeinfo,  EhCatchTypeinfo,    rust_eh_catch_typeinfo;
-    oom,                Oom,                rust_oom;
+    PanicImpl,          rust_begin_unwind;
+    EhPersonality,      rust_eh_personality;
+    EhCatchTypeinfo,    rust_eh_catch_typeinfo;
+    Oom,                rust_oom;
 }

compiler/rustc_hir/src/weak_lang_items.rs

@@ -23,7 +23,6 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{walk_generics, Visitor as _};
-use rustc_hir::lang_items::LangItem;
 use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
@@ -884,9 +883,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             }
         }
 
-        let sized_def_id = tcx.lang_items().require(LangItem::Sized);
+        let sized_def_id = tcx.lang_items().sized_trait();
         match (&sized_def_id, unbound) {
-            (Ok(sized_def_id), Some(tpb))
+            (Some(sized_def_id), Some(tpb))
                 if tpb.path.res == Res::Def(DefKind::Trait, *sized_def_id) =>
             {
                 // There was in fact a `?Sized` bound, return without doing anything
@@ -906,7 +905,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 // There was no `?Sized` bound; add implicitly sized if `Sized` is available.
             }
         }
-        if sized_def_id.is_err() {
+        if sized_def_id.is_none() {
             // No lang item for `Sized`, so we can't add it as a bound.
             return;
         }

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -27,8 +27,8 @@ use rustc_hir as hir;
 use rustc_hir::def::CtorKind;
 use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::weak_lang_items;
-use rustc_hir::{GenericParamKind, Node};
+use rustc_hir::weak_lang_items::WEAK_LANG_ITEMS;
+use rustc_hir::{lang_items, GenericParamKind, LangItem, Node};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::mir::mono::Linkage;
@@ -2104,12 +2104,15 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
     // strippable by the linker.
     //
     // Additionally weak lang items have predetermined symbol names.
-    if tcx.is_weak_lang_item(did.to_def_id()) {
+    if WEAK_LANG_ITEMS.iter().any(|&l| tcx.lang_items().get(l) == Some(did.to_def_id())) {
         codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
     }
-    if let Some(name) = weak_lang_items::link_name(attrs) {
-        codegen_fn_attrs.export_name = Some(name);
-        codegen_fn_attrs.link_name = Some(name);
+    if let Some((name, _)) = lang_items::extract(attrs)
+        && let Some(lang_item) = LangItem::from_name(name)
+        && let Some(link_name) = lang_item.link_name()
+    {
+        codegen_fn_attrs.export_name = Some(link_name);
+        codegen_fn_attrs.link_name = Some(link_name);
     }
     check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, link_ordinal_span);
 

compiler/rustc_hir_analysis/src/collect.rs

@@ -15,7 +15,6 @@ use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
 use rustc_hir::diagnostic_items::DiagnosticItems;
-use rustc_hir::lang_items;
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::metadata::ModChild;
 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
@@ -967,7 +966,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     /// Iterates over the language items in the given crate.
-    fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
+    fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, LangItem)] {
         tcx.arena.alloc_from_iter(
             self.root
                 .lang_items
@@ -1319,7 +1318,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         )
     }
 
-    fn get_missing_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [lang_items::LangItem] {
+    fn get_missing_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [LangItem] {
         tcx.arena.alloc_from_iter(self.root.lang_items_missing.decode(self))
     }
 

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -17,7 +17,7 @@ use rustc_hir::def_id::{
 };
 use rustc_hir::definitions::DefPathData;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::lang_items;
+use rustc_hir::lang_items::LangItem;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::dependency_format::Linkage;
 use rustc_middle::middle::exported_symbols::{
@@ -1905,22 +1905,15 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         self.lazy_array(diagnostic_items.iter().map(|(&name, def_id)| (name, def_id.index)))
     }
 
-    fn encode_lang_items(&mut self) -> LazyArray<(DefIndex, usize)> {
+    fn encode_lang_items(&mut self) -> LazyArray<(DefIndex, LangItem)> {
         empty_proc_macro!(self);
-        let tcx = self.tcx;
-        let lang_items = tcx.lang_items();
-        let lang_items = lang_items.items().iter();
-        self.lazy_array(lang_items.enumerate().filter_map(|(i, &opt_def_id)| {
-            if let Some(def_id) = opt_def_id {
-                if def_id.is_local() {
-                    return Some((def_id.index, i));
-                }
-            }
-            None
+        let lang_items = self.tcx.lang_items().iter();
+        self.lazy_array(lang_items.filter_map(|(lang_item, def_id)| {
+            def_id.as_local().map(|id| (id.local_def_index, lang_item))
         }))
     }
 
-    fn encode_lang_items_missing(&mut self) -> LazyArray<lang_items::LangItem> {
+    fn encode_lang_items_missing(&mut self) -> LazyArray<LangItem> {
         empty_proc_macro!(self);
         let tcx = self.tcx;
         self.lazy_array(&tcx.lang_items().missing)