Auto merge of #124953 - compiler-errors:own-params, r=lcnr

Rename `Generics::params` to `Generics::own_params`

I hope this makes it slightly more obvious that `generics.own_params` is insufficient when considering nested items. I didn't actually audit any of the usages, for the record.

r? lcnr

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -317,36 +317,39 @@ impl<'tcx> BorrowExplanation<'tcx> {
             let mut has_dyn = false;
             let mut failed = false;
 
-            let elaborated_args = std::iter::zip(*args, &generics.params).map(|(arg, param)| {
-                if let Some(ty::Dynamic(obj, _, ty::Dyn)) = arg.as_type().map(Ty::kind) {
-                    let default = tcx.object_lifetime_default(param.def_id);
-
-                    let re_static = tcx.lifetimes.re_static;
-
-                    let implied_region = match default {
-                        // This is not entirely precise.
-                        ObjectLifetimeDefault::Empty => re_static,
-                        ObjectLifetimeDefault::Ambiguous => {
-                            failed = true;
-                            re_static
-                        }
-                        ObjectLifetimeDefault::Param(param_def_id) => {
-                            let index = generics.param_def_id_to_index[&param_def_id] as usize;
-                            args.get(index).and_then(|arg| arg.as_region()).unwrap_or_else(|| {
+            let elaborated_args =
+                std::iter::zip(*args, &generics.own_params).map(|(arg, param)| {
+                    if let Some(ty::Dynamic(obj, _, ty::Dyn)) = arg.as_type().map(Ty::kind) {
+                        let default = tcx.object_lifetime_default(param.def_id);
+
+                        let re_static = tcx.lifetimes.re_static;
+
+                        let implied_region = match default {
+                            // This is not entirely precise.
+                            ObjectLifetimeDefault::Empty => re_static,
+                            ObjectLifetimeDefault::Ambiguous => {
                                 failed = true;
                                 re_static
-                            })
-                        }
-                        ObjectLifetimeDefault::Static => re_static,
-                    };
+                            }
+                            ObjectLifetimeDefault::Param(param_def_id) => {
+                                let index = generics.param_def_id_to_index[&param_def_id] as usize;
+                                args.get(index).and_then(|arg| arg.as_region()).unwrap_or_else(
+                                    || {
+                                        failed = true;
+                                        re_static
+                                    },
+                                )
+                            }
+                            ObjectLifetimeDefault::Static => re_static,
+                        };
 
-                    has_dyn = true;
+                        has_dyn = true;
 
-                    Ty::new_dynamic(tcx, obj, implied_region, ty::Dyn).into()
-                } else {
-                    arg
-                }
-            });
+                        Ty::new_dynamic(tcx, obj, implied_region, ty::Dyn).into()
+                    } else {
+                        arg
+                    }
+                });
             let elaborated_ty = Ty::new_adt(tcx, *def, tcx.mk_args_from_iter(elaborated_args));
 
             if has_dyn && !failed {

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1281,7 +1281,7 @@ fn build_generic_type_param_di_nodes<'ll, 'tcx>(
         let mut names = generics
             .parent
             .map_or_else(Vec::new, |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
-        names.extend(generics.params.iter().map(|param| param.name));
+        names.extend(generics.own_params.iter().map(|param| param.name));
         names
     }
 }

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -512,7 +512,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             let mut names = generics.parent.map_or_else(Vec::new, |def_id| {
                 get_parameter_names(cx, cx.tcx.generics_of(def_id))
             });
-            names.extend(generics.params.iter().map(|param| param.name));
+            names.extend(generics.own_params.iter().map(|param| param.name));
             names
         }
 

compiler/rustc_hir_analysis/src/check/check.rs

@@ -561,7 +561,7 @@ fn check_opaque_precise_captures<'tcx>(tcx: TyCtxt<'tcx>, opaque_def_id: LocalDe
         let generics = tcx.generics_of(generics);
         def_id = generics.parent;
 
-        for param in &generics.params {
+        for param in &generics.own_params {
             if expected_captures.contains(&param.def_id) {
                 assert_eq!(
                     variances[param.index as usize],
@@ -778,7 +778,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                         let def_id = item.id.owner_id.def_id;
                         let generics = tcx.generics_of(def_id);
                         let own_counts = generics.own_counts();
-                        if generics.params.len() - own_counts.lifetimes != 0 {
+                        if generics.own_params.len() - own_counts.lifetimes != 0 {
                             let (kinds, kinds_pl, egs) = match (own_counts.types, own_counts.consts)
                             {
                                 (_, 0) => ("type", "types", Some("u32")),
@@ -1544,7 +1544,7 @@ fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalD
             .collect::<FxIndexMap<_, _>>()
     });
 
-    let mut params_used = BitSet::new_empty(generics.params.len());
+    let mut params_used = BitSet::new_empty(generics.own_params.len());
     for leaf in ty.walk() {
         if let GenericArgKind::Type(leaf_ty) = leaf.unpack()
             && let ty::Param(param) = leaf_ty.kind()
@@ -1554,7 +1554,7 @@ fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalD
         }
     }
 
-    for param in &generics.params {
+    for param in &generics.own_params {
         if !params_used.contains(param.index)
             && let ty::GenericParamDefKind::Type { .. } = param.kind
         {

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -716,7 +716,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
                 // since we previously enforce that the trait method and impl method have the
                 // same generics.
                 let num_trait_args = trait_to_impl_args.len();
-                let num_impl_args = tcx.generics_of(impl_m.container_id(tcx)).params.len();
+                let num_impl_args = tcx.generics_of(impl_m.container_id(tcx)).own_params.len();
                 let ty = match ty.try_fold_with(&mut RemapHiddenTyRegions {
                     tcx,
                     map,
@@ -1494,14 +1494,16 @@ fn compare_synthetic_generics<'tcx>(
     let mut error_found = None;
     let impl_m_generics = tcx.generics_of(impl_m.def_id);
     let trait_m_generics = tcx.generics_of(trait_m.def_id);
-    let impl_m_type_params = impl_m_generics.params.iter().filter_map(|param| match param.kind {
-        GenericParamDefKind::Type { synthetic, .. } => Some((param.def_id, synthetic)),
-        GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => None,
-    });
-    let trait_m_type_params = trait_m_generics.params.iter().filter_map(|param| match param.kind {
-        GenericParamDefKind::Type { synthetic, .. } => Some((param.def_id, synthetic)),
-        GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => None,
-    });
+    let impl_m_type_params =
+        impl_m_generics.own_params.iter().filter_map(|param| match param.kind {
+            GenericParamDefKind::Type { synthetic, .. } => Some((param.def_id, synthetic)),
+            GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => None,
+        });
+    let trait_m_type_params =
+        trait_m_generics.own_params.iter().filter_map(|param| match param.kind {
+            GenericParamDefKind::Type { synthetic, .. } => Some((param.def_id, synthetic)),
+            GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => None,
+        });
     for ((impl_def_id, impl_synthetic), (trait_def_id, trait_synthetic)) in
         iter::zip(impl_m_type_params, trait_m_type_params)
     {
@@ -1639,7 +1641,7 @@ fn compare_generic_param_kinds<'tcx>(
     assert_eq!(impl_item.kind, trait_item.kind);
 
     let ty_const_params_of = |def_id| {
-        tcx.generics_of(def_id).params.iter().filter(|param| {
+        tcx.generics_of(def_id).own_params.iter().filter(|param| {
             matches!(
                 param.kind,
                 GenericParamDefKind::Const { .. } | GenericParamDefKind::Type { .. }
@@ -2140,7 +2142,7 @@ fn param_env_with_gat_bounds<'tcx>(
         };
 
         let mut bound_vars: smallvec::SmallVec<[ty::BoundVariableKind; 8]> =
-            smallvec::SmallVec::with_capacity(tcx.generics_of(impl_ty.def_id).params.len());
+            smallvec::SmallVec::with_capacity(tcx.generics_of(impl_ty.def_id).own_params.len());
         // Extend the impl's identity args with late-bound GAT vars
         let normalize_impl_ty_args = ty::GenericArgs::identity_for_item(tcx, container_id)
             .extend_to(tcx, impl_ty.def_id, |param, _| match param.kind {

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -431,7 +431,7 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, trait_def_id: LocalDefId) {
             }
             let gat_generics = tcx.generics_of(gat_def_id);
             // FIXME(jackh726): we can also warn in the more general case
-            if gat_generics.params.is_empty() {
+            if gat_generics.own_params.is_empty() {
                 continue;
             }
 
@@ -1400,7 +1400,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
     //     struct Foo<T = Vec<[u32]>> { .. }
     //
     // Here, the default `Vec<[u32]>` is not WF because `[u32]: Sized` does not hold.
-    for param in &generics.params {
+    for param in &generics.own_params {
         match param.kind {
             GenericParamDefKind::Type { .. } => {
                 if is_our_default(param) {
@@ -1879,7 +1879,7 @@ fn check_variances_for_type_defn<'tcx>(
             continue;
         }
 
-        let ty_param = &ty_generics.params[index];
+        let ty_param = &ty_generics.own_params[index];
         let hir_param = &hir_generics.params[index];
 
         if ty_param.def_id != hir_param.def_id.into() {

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -571,7 +571,7 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for TyVarReplacer<'cx, 'tcx> {
         if let Some(def_id) = origin.param_def_id {
             // The generics of an `impl` don't have a parent, we can index directly.
             let index = self.generics.param_def_id_to_index[&def_id];
-            let name = self.generics.params[index as usize].name;
+            let name = self.generics.own_params[index as usize].name;
 
             Ty::new_param(self.infcx.tcx, index, name)
         } else {

compiler/rustc_hir_analysis/src/coherence/unsafety.rs

@@ -14,7 +14,7 @@ pub(super) fn check_item(
     trait_def: &TraitDef,
 ) -> Result<(), ErrorGuaranteed> {
     let unsafe_attr =
-        tcx.generics_of(def_id).params.iter().find(|p| p.pure_wrt_drop).map(|_| "may_dangle");
+        tcx.generics_of(def_id).own_params.iter().find(|p| p.pure_wrt_drop).map(|_| "may_dangle");
     let trait_ref = trait_header.trait_ref.instantiate_identity();
 
     match (trait_def.unsafety, unsafe_attr, trait_header.unsafety, trait_header.polarity) {

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -22,28 +22,28 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         let trait_def_id = tcx.parent(fn_def_id);
         let opaque_ty_generics = tcx.generics_of(opaque_def_id);
         let opaque_ty_parent_count = opaque_ty_generics.parent_count;
-        let mut params = opaque_ty_generics.params.clone();
+        let mut own_params = opaque_ty_generics.own_params.clone();
 
         let parent_generics = tcx.generics_of(trait_def_id);
-        let parent_count = parent_generics.parent_count + parent_generics.params.len();
+        let parent_count = parent_generics.parent_count + parent_generics.own_params.len();
 
-        let mut trait_fn_params = tcx.generics_of(fn_def_id).params.clone();
+        let mut trait_fn_params = tcx.generics_of(fn_def_id).own_params.clone();
 
-        for param in &mut params {
+        for param in &mut own_params {
             param.index = param.index + parent_count as u32 + trait_fn_params.len() as u32
                 - opaque_ty_parent_count as u32;
         }
 
-        trait_fn_params.extend(params);
-        params = trait_fn_params;
+        trait_fn_params.extend(own_params);
+        own_params = trait_fn_params;
 
         let param_def_id_to_index =
-            params.iter().map(|param| (param.def_id, param.index)).collect();
+            own_params.iter().map(|param| (param.def_id, param.index)).collect();
 
         return ty::Generics {
             parent: Some(trait_def_id),
             parent_count,
-            params,
+            own_params,
             param_def_id_to_index,
             has_self: opaque_ty_generics.has_self,
             has_late_bound_regions: opaque_ty_generics.has_late_bound_regions,
@@ -124,17 +124,17 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                     let generics = tcx.generics_of(parent_def_id.to_def_id());
                     let param_def_idx = generics.param_def_id_to_index[&param_id.to_def_id()];
                     // In the above example this would be .params[..N#0]
-                    let params = generics.params_to(param_def_idx as usize, tcx).to_owned();
+                    let own_params = generics.params_to(param_def_idx as usize, tcx).to_owned();
                     let param_def_id_to_index =
-                        params.iter().map(|param| (param.def_id, param.index)).collect();
+                        own_params.iter().map(|param| (param.def_id, param.index)).collect();
 
                     return ty::Generics {
                         // we set the parent of these generics to be our parent's parent so that we
                         // dont end up with args: [N, M, N] for the const default on a struct like this:
                         // struct Foo<const N: usize, const M: usize = { ... }>;
                         parent: generics.parent,
                         parent_count: generics.parent_count,
-                        params,
+                        own_params,
                         param_def_id_to_index,
                         has_self: generics.has_self,
                         has_late_bound_regions: generics.has_late_bound_regions,
@@ -274,17 +274,17 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         parent_has_self = generics.has_self;
         host_effect_index = generics.host_effect_index;
         own_start = generics.count() as u32;
-        generics.parent_count + generics.params.len()
+        generics.parent_count + generics.own_params.len()
     });
 
-    let mut params: Vec<_> = Vec::with_capacity(hir_generics.params.len() + has_self as usize);
+    let mut own_params: Vec<_> = Vec::with_capacity(hir_generics.params.len() + has_self as usize);
 
     if let Some(opt_self) = opt_self {
-        params.push(opt_self);
+        own_params.push(opt_self);
     }
 
     let early_lifetimes = super::early_bound_lifetimes_from_generics(tcx, hir_generics);
-    params.extend(early_lifetimes.enumerate().map(|(i, param)| ty::GenericParamDef {
+    own_params.extend(early_lifetimes.enumerate().map(|(i, param)| ty::GenericParamDef {
         name: param.name.ident().name,
         index: own_start + i as u32,
         def_id: param.def_id.to_def_id(),
@@ -293,7 +293,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     }));
 
     // Now create the real type and const parameters.
-    let type_start = own_start - has_self as u32 + params.len() as u32;
+    let type_start = own_start - has_self as u32 + own_params.len() as u32;
     let mut i: u32 = 0;
     let mut next_index = || {
         let prev = i;
@@ -304,7 +304,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     const TYPE_DEFAULT_NOT_ALLOWED: &'static str = "defaults for type parameters are only allowed in \
     `struct`, `enum`, `type`, or `trait` definitions";
 
-    params.extend(hir_generics.params.iter().filter_map(|param| match param.kind {
+    own_params.extend(hir_generics.params.iter().filter_map(|param| match param.kind {
         GenericParamKind::Lifetime { .. } => None,
         GenericParamKind::Type { default, synthetic, .. } => {
             if default.is_some() {
@@ -404,7 +404,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
             ][..],
         };
 
-        params.extend(dummy_args.iter().map(|&arg| ty::GenericParamDef {
+        own_params.extend(dummy_args.iter().map(|&arg| ty::GenericParamDef {
             index: next_index(),
             name: Symbol::intern(arg),
             def_id: def_id.to_def_id(),
@@ -415,7 +415,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
 
     // provide junk type parameter defs for const blocks.
     if let Node::ConstBlock(_) = node {
-        params.push(ty::GenericParamDef {
+        own_params.push(ty::GenericParamDef {
             index: next_index(),
             name: Symbol::intern("<const_ty>"),
             def_id: def_id.to_def_id(),
@@ -424,12 +424,13 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         });
     }
 
-    let param_def_id_to_index = params.iter().map(|param| (param.def_id, param.index)).collect();
+    let param_def_id_to_index =
+        own_params.iter().map(|param| (param.def_id, param.index)).collect();
 
     ty::Generics {
         parent: parent_def_id,
         parent_count,
-        params,
+        own_params,
         param_def_id_to_index,
         has_self: has_self || parent_has_self,
         has_late_bound_regions: has_late_bound_regions(tcx, node),

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -73,8 +73,8 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
             // opaque lifetimes, which explains the slicing below.
             compute_bidirectional_outlives_predicates(
                 tcx,
-                &tcx.generics_of(def_id.to_def_id()).params
-                    [tcx.generics_of(fn_def_id).params.len()..],
+                &tcx.generics_of(def_id.to_def_id()).own_params
+                    [tcx.generics_of(fn_def_id).own_params.len()..],
                 &mut predicates,
             );
 
@@ -300,7 +300,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
         };
         debug!(?lifetimes);
 
-        compute_bidirectional_outlives_predicates(tcx, &generics.params, &mut predicates);
+        compute_bidirectional_outlives_predicates(tcx, &generics.own_params, &mut predicates);
         debug!(?predicates);
     }
 

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1562,7 +1562,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                 ObjectLifetimeDefault::Ambiguous => None,
             };
             generics
-                .params
+                .own_params
                 .iter()
                 .filter_map(|param| {
                     match self.tcx.def_kind(param.def_id) {
@@ -1668,7 +1668,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                         binding.ident,
                         ty::AssocKind::Fn,
                     ) {
-                    bound_vars.extend(self.tcx.generics_of(assoc_fn.def_id).params.iter().map(
+                    bound_vars.extend(self.tcx.generics_of(assoc_fn.def_id).own_params.iter().map(
                         |param| match param.kind {
                             ty::GenericParamDefKind::Lifetime => ty::BoundVariableKind::Region(
                                 ty::BoundRegionKind::BrNamed(param.def_id, param.name),
@@ -2003,7 +2003,8 @@ fn is_late_bound_map(
                     // just consider args to be unconstrained.
                     let generics = self.tcx.generics_of(alias_def);
                     let mut walker = ConstrainedCollectorPostHirTyLowering {
-                        arg_is_constrained: vec![false; generics.params.len()].into_boxed_slice(),
+                        arg_is_constrained: vec![false; generics.own_params.len()]
+                            .into_boxed_slice(),
                     };
                     walker.visit_ty(self.tcx.type_of(alias_def).instantiate_identity());