Use FxIndexMap instead of otherwise unused StableMap for WEAK_ITEMS_REFS.

Author: michaelwoerister

compiler/rustc_hir/src/lang_items.rs

@@ -11,7 +11,7 @@ use crate::def_id::DefId;
 use crate::{MethodKind, Target};
 
 use rustc_ast as ast;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::HashStable_Generic;
 use rustc_span::symbol::{kw, sym, Symbol};
@@ -134,8 +134,8 @@ macro_rules! language_item_table {
         }
 
         /// A mapping from the name of the lang item to its order and the form it must be of.
-        pub static ITEM_REFS: LazyLock<FxHashMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
-            let mut item_refs = FxHashMap::default();
+        pub static ITEM_REFS: LazyLock<FxIndexMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
+            let mut item_refs = FxIndexMap::default();
             $( item_refs.insert($module::$name, (LangItem::$variant as usize, $target)); )*
             item_refs
         });

compiler/rustc_hir/src/weak_lang_items.rs

@@ -4,16 +4,16 @@ use crate::def_id::DefId;
 use crate::{lang_items, LangItem, LanguageItems};
 
 use rustc_ast as ast;
-use rustc_data_structures::stable_map::StableMap;
+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<StableMap<Symbol, LangItem>> = LazyLock::new(|| {
-    let mut map = StableMap::default();
+pub static WEAK_ITEMS_REFS: LazyLock<FxIndexMap<Symbol, LangItem>> = LazyLock::new(|| {
+    let mut map = FxIndexMap::default();
     $(map.insert(sym::$name, LangItem::$item);)*
     map
 });

compiler/rustc_passes/src/weak_lang_items.rs

@@ -68,7 +68,7 @@ fn verify<'tcx>(tcx: TyCtxt<'tcx>, items: &lang_items::LanguageItems) {
         }
     }
 
-    for (name, item) in WEAK_ITEMS_REFS.clone().into_sorted_vector().into_iter() {
+    for (name, &item) in WEAK_ITEMS_REFS.iter() {
         if missing.contains(&item) && required(tcx, item) && items.require(item).is_err() {
             if item == LangItem::PanicImpl {
                 tcx.sess.err("`#[panic_handler]` function required, but not found");

src/test/ui/extern-flag/empty-extern-arg.stderr

@@ -1,11 +1,11 @@
 error: extern location for std does not exist: 
 
+error: `#[panic_handler]` function required, but not found
+
 error: language item required, but not found: `eh_personality`
    |
    = note: this can occur when a binary crate with `#![no_std]` is compiled for a target where `eh_personality` is defined in the standard library
    = help: you may be able to compile for a target that doesn't need `eh_personality`, specify a target with `--target` or in `.cargo/config`
 
-error: `#[panic_handler]` function required, but not found
-
 error: aborting due to 3 previous errors
 

src/test/ui/panic-handler/weak-lang-item.stderr

@@ -10,13 +10,13 @@ help: you can use `as` to change the binding name of the import
 LL | extern crate core as other_core;
    |
 
+error: `#[panic_handler]` function required, but not found
+
 error: language item required, but not found: `eh_personality`
    |
    = note: this can occur when a binary crate with `#![no_std]` is compiled for a target where `eh_personality` is defined in the standard library
    = help: you may be able to compile for a target that doesn't need `eh_personality`, specify a target with `--target` or in `.cargo/config`
 
-error: `#[panic_handler]` function required, but not found
-
 error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0259`.