Auto merge of rust-lang#125006 - spastorino:generics-is-empty, r=compiler-errors

Add and use generics.is_empty() and generics.is_own_empty, rather than using generics' attributes

r? `@compiler-errors`

Related to rust-lang#123929

Author: bors

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -432,7 +432,7 @@ 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.own_params.is_empty() {
+            if gat_generics.is_own_empty() {
                 continue;
             }
 

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -1409,7 +1409,7 @@ fn generics_args_err_extend<'a>(
             // it was done based on the end of assoc segment but that sometimes
             // led to impossible spans and caused issues like #116473
             let args_span = args.span_ext.with_lo(args.span_ext.lo() - BytePos(2));
-            if tcx.generics_of(adt_def.did()).count() == 0 {
+            if tcx.generics_of(adt_def.did()).is_empty() {
                 // FIXME(estebank): we could also verify that the arguments being
                 // work for the `enum`, instead of just looking if it takes *any*.
                 err.span_suggestion_verbose(

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -412,7 +412,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // Traits always have `Self` as a generic parameter, which means they will not return early
         // here and so associated type bindings will be handled regardless of whether there are any
         // non-`Self` generic parameters.
-        if generics.own_params.is_empty() {
+        if generics.is_own_empty() {
             return (tcx.mk_args(parent_args), arg_count);
         }
 

compiler/rustc_hir_analysis/src/lib.rs

@@ -181,7 +181,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         let def_kind = tcx.def_kind(item_def_id);
         match def_kind {
             DefKind::Static { .. } => tcx.ensure().eval_static_initializer(item_def_id),
-            DefKind::Const if tcx.generics_of(item_def_id).own_params.is_empty() => {
+            DefKind::Const if tcx.generics_of(item_def_id).is_empty() => {
                 let instance = ty::Instance::new(item_def_id.into(), ty::GenericArgs::empty());
                 let cid = GlobalId { instance, promoted: None };
                 let param_env = ty::ParamEnv::reveal_all();

compiler/rustc_hir_analysis/src/variance/constraints.rs

@@ -99,7 +99,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
         debug!("build_constraints_for_item({})", tcx.def_path_str(def_id));
 
         // Skip items with no generics - there's nothing to infer in them.
-        if tcx.generics_of(def_id).count() == 0 {
+        if tcx.generics_of(def_id).is_empty() {
             return;
         }
 

compiler/rustc_hir_analysis/src/variance/mod.rs

@@ -41,7 +41,7 @@ fn crate_variances(tcx: TyCtxt<'_>, (): ()) -> CrateVariancesMap<'_> {
 
 fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
     // Skip items with no generics - there's nothing to infer in them.
-    if tcx.generics_of(item_def_id).count() == 0 {
+    if tcx.generics_of(item_def_id).is_empty() {
         return &[];
     }
 

compiler/rustc_hir_typeck/src/method/confirm.rs

@@ -451,7 +451,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         // `foo.bar::<u32>(...)` -- the `Self` type here will be the
         // type of `foo` (possibly adjusted), but we don't want to
         // include that. We want just the `[_, u32]` part.
-        if !args.is_empty() && !generics.own_params.is_empty() {
+        if !args.is_empty() && !generics.is_own_empty() {
             let user_type_annotation = self.probe(|_| {
                 let user_args = UserArgs {
                     args: GenericArgs::for_item(self.tcx, pick.item.def_id, |param, _| {

compiler/rustc_hir_typeck/src/method/prelude2021.rs

@@ -279,7 +279,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if !self_ty_name.contains('<') {
                     if let ty::Adt(def, _) = self_ty.kind() {
                         let generics = self.tcx.generics_of(def.did());
-                        if !generics.own_params.is_empty() {
+                        if !generics.is_own_empty() {
                             let counts = generics.own_counts();
                             self_ty_name += &format!(
                                 "<{}>",

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -1754,7 +1754,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let generics = self.tcx.generics_of(method);
         assert_eq!(args.len(), generics.parent_count);
 
-        let xform_fn_sig = if generics.own_params.is_empty() {
+        let xform_fn_sig = if generics.is_own_empty() {
             fn_sig.instantiate(self.tcx, args)
         } else {
             let args = GenericArgs::for_item(self.tcx, method, |param, _| {

compiler/rustc_middle/src/ty/generics.rs

@@ -391,6 +391,14 @@ impl<'tcx> Generics {
         }
         false
     }
+
+    pub fn is_empty(&'tcx self) -> bool {
+        self.count() == 0
+    }
+
+    pub fn is_own_empty(&'tcx self) -> bool {
+        self.own_params.is_empty()
+    }
 }
 
 /// Bounds on generics.