Auto merge of rust-lang#138837 - petrochenkov:resinstab2, r=<try>

resolve: Avoid remaining unstable iteration

Continuation of rust-lang#138580.
This should be the performance sensitive part.

Author: bors

compiler/rustc_resolve/src/late.rs

@@ -272,7 +272,7 @@ impl RibKind<'_> {
 /// resolving, the name is looked up from inside out.
 #[derive(Debug)]
 pub(crate) struct Rib<'ra, R = Res> {
-    pub bindings: FxHashMap<Ident, R>,
+    pub bindings: FxIndexMap<Ident, R>,
     pub patterns_with_skipped_bindings: UnordMap<DefId, Vec<(Span, Result<(), ErrorGuaranteed>)>>,
     pub kind: RibKind<'ra>,
 }
@@ -1642,8 +1642,8 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 
                         // Allow all following defaults to refer to this type parameter.
                         let i = &Ident::with_dummy_span(param.ident.name);
-                        forward_ty_ban_rib.bindings.remove(i);
-                        forward_ty_ban_rib_const_param_ty.bindings.remove(i);
+                        forward_ty_ban_rib.bindings.swap_remove(i);
+                        forward_ty_ban_rib_const_param_ty.bindings.swap_remove(i);
                     }
                     GenericParamKind::Const { ref ty, kw_span: _, ref default } => {
                         // Const parameters can't have param bounds.
@@ -1678,8 +1678,8 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 
                         // Allow all following defaults to refer to this const parameter.
                         let i = &Ident::with_dummy_span(param.ident.name);
-                        forward_const_ban_rib.bindings.remove(i);
-                        forward_const_ban_rib_const_param_ty.bindings.remove(i);
+                        forward_const_ban_rib.bindings.swap_remove(i);
+                        forward_const_ban_rib_const_param_ty.bindings.swap_remove(i);
                     }
                 }
             }
@@ -2888,7 +2888,6 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                         break;
                     }
 
-                    #[allow(rustc::potential_query_instability)] // FIXME
                     seen_bindings
                         .extend(parent_rib.bindings.keys().map(|ident| (*ident, ident.span)));
                 }
@@ -4003,7 +4002,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         }
     }
 
-    fn innermost_rib_bindings(&mut self, ns: Namespace) -> &mut FxHashMap<Ident, Res> {
+    fn innermost_rib_bindings(&mut self, ns: Namespace) -> &mut FxIndexMap<Ident, Res> {
         &mut self.ribs[ns].last_mut().unwrap().bindings
     }
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -830,7 +830,6 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         if let Some(rib) = &self.last_block_rib
             && let RibKind::Normal = rib.kind
         {
-            #[allow(rustc::potential_query_instability)] // FIXME
             for (ident, &res) in &rib.bindings {
                 if let Res::Local(_) = res
                     && path.len() == 1
@@ -1019,7 +1018,6 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         if let Some(err_code) = err.code {
             if err_code == E0425 {
                 for label_rib in &self.label_ribs {
-                    #[allow(rustc::potential_query_instability)] // FIXME
                     for (label_ident, node_id) in &label_rib.bindings {
                         let ident = path.last().unwrap().ident;
                         if format!("'{ident}") == label_ident.to_string() {
@@ -2265,7 +2263,6 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 };
 
                 // Locals and type parameters
-                #[allow(rustc::potential_query_instability)] // FIXME
                 for (ident, &res) in &rib.bindings {
                     if filter_fn(res) && ident.span.ctxt() == rib_ctxt {
                         names.push(TypoSuggestion::typo_from_ident(*ident, res));
@@ -2793,7 +2790,6 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         let within_scope = self.is_label_valid_from_rib(rib_index);
 
         let rib = &self.label_ribs[rib_index];
-        #[allow(rustc::potential_query_instability)] // FIXME
         let names = rib
             .bindings
             .iter()
@@ -2805,7 +2801,6 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             // Upon finding a similar name, get the ident that it was from - the span
             // contained within helps make a useful diagnostic. In addition, determine
             // whether this candidate is within scope.
-            #[allow(rustc::potential_query_instability)] // FIXME
             let (ident, _) = rib.bindings.iter().find(|(ident, _)| ident.name == symbol).unwrap();
             (*ident, within_scope)
         })