extend Ty and TyCtxt lints to self types

compiler/rustc_lint/src/internal.rs

@@ -5,7 +5,9 @@ use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}
 use rustc_ast::{Item, ItemKind};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::Applicability;
+use rustc_hir::def::Res;
 use rustc_hir::{GenericArg, HirId, MutTy, Mutability, Path, PathSegment, QPath, Ty, TyKind};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -177,11 +179,31 @@ fn lint_ty_kind_usage(cx: &LateContext<'_>, segment: &PathSegment<'_>) -> bool {
 fn is_ty_or_ty_ctxt(cx: &LateContext<'_>, ty: &Ty<'_>) -> Option<String> {
     if let TyKind::Path(qpath) = &ty.kind {
         if let QPath::Resolved(_, path) = qpath {
-            let did = path.res.opt_def_id()?;
-            if cx.tcx.is_diagnostic_item(sym::Ty, did) {
-                return Some(format!("Ty{}", gen_args(path.segments.last().unwrap())));
-            } else if cx.tcx.is_diagnostic_item(sym::TyCtxt, did) {
-                return Some(format!("TyCtxt{}", gen_args(path.segments.last().unwrap())));
+            match path.res {
+                Res::Def(_, did) => {
+                    if cx.tcx.is_diagnostic_item(sym::Ty, did) {
+                        return Some(format!("Ty{}", gen_args(path.segments.last().unwrap())));
+                    } else if cx.tcx.is_diagnostic_item(sym::TyCtxt, did) {
+                        return Some(format!("TyCtxt{}", gen_args(path.segments.last().unwrap())));
+                    }
+                }
+                // Only lint on `&Ty` and `&TyCtxt` if it is used outside of a trait.
+                Res::SelfTy(None, Some((did, _))) => {
+                    if let ty::Adt(adt, substs) = cx.tcx.type_of(did).kind() {
+                        if cx.tcx.is_diagnostic_item(sym::Ty, adt.did) {
+                            // NOTE: This path is currently unreachable as `Ty<'tcx>` is
+                            // defined as a type alias meaning that `impl<'tcx> Ty<'tcx>`
+                            // is not actually allowed.
+                            //
+                            // I(@lcnr) still kept this branch in so we don't miss this
+                            // if we ever change it in the future.
+                            return Some(format!("Ty<{}>", substs[0]));
+                        } else if cx.tcx.is_diagnostic_item(sym::TyCtxt, adt.did) {
+                            return Some(format!("TyCtxt<{}>", substs[0]));
+                        }
+                    }
+                }
+                _ => (),
             }
         }
     }

compiler/rustc_middle/src/middle/lang_items.rs

@@ -17,7 +17,7 @@ use rustc_target::spec::PanicStrategy;
 impl<'tcx> TyCtxt<'tcx> {
     /// Returns the `DefId` for a given `LangItem`.
     /// If not found, fatally aborts compilation.
-    pub fn require_lang_item(&self, lang_item: LangItem, span: Option<Span>) -> DefId {
+    pub fn require_lang_item(self, lang_item: LangItem, span: Option<Span>) -> DefId {
         self.lang_items().require(lang_item).unwrap_or_else(|msg| {
             if let Some(span) = span {
                 self.sess.span_fatal(span, &msg)
@@ -27,7 +27,7 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn fn_trait_kind_from_lang_item(&self, id: DefId) -> Option<ty::ClosureKind> {
+    pub fn fn_trait_kind_from_lang_item(self, id: DefId) -> Option<ty::ClosureKind> {
         let items = self.lang_items();
         match Some(id) {
             x if x == items.fn_trait() => Some(ty::ClosureKind::Fn),
@@ -37,7 +37,7 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    pub fn is_weak_lang_item(&self, item_def_id: DefId) -> bool {
+    pub fn is_weak_lang_item(self, item_def_id: DefId) -> bool {
         self.lang_items().is_weak_lang_item(item_def_id)
     }
 }

compiler/rustc_middle/src/mir/interpret/mod.rs

@@ -447,14 +447,14 @@ impl<'tcx> TyCtxt<'tcx> {
     ///
     /// Make sure to call `set_alloc_id_memory` or `set_alloc_id_same_memory` before returning such
     /// an `AllocId` from a query.
-    pub fn reserve_alloc_id(&self) -> AllocId {
+    pub fn reserve_alloc_id(self) -> AllocId {
         self.alloc_map.lock().reserve()
     }
 
     /// Reserves a new ID *if* this allocation has not been dedup-reserved before.
     /// Should only be used for function pointers and statics, we don't want
     /// to dedup IDs for "real" memory!
-    fn reserve_and_set_dedup(&self, alloc: GlobalAlloc<'tcx>) -> AllocId {
+    fn reserve_and_set_dedup(self, alloc: GlobalAlloc<'tcx>) -> AllocId {
         let mut alloc_map = self.alloc_map.lock();
         match alloc {
             GlobalAlloc::Function(..) | GlobalAlloc::Static(..) => {}
@@ -472,13 +472,13 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Generates an `AllocId` for a static or return a cached one in case this function has been
     /// called on the same static before.
-    pub fn create_static_alloc(&self, static_id: DefId) -> AllocId {
+    pub fn create_static_alloc(self, static_id: DefId) -> AllocId {
         self.reserve_and_set_dedup(GlobalAlloc::Static(static_id))
     }
 
     /// Generates an `AllocId` for a function.  Depending on the function type,
     /// this might get deduplicated or assigned a new ID each time.
-    pub fn create_fn_alloc(&self, instance: Instance<'tcx>) -> AllocId {
+    pub fn create_fn_alloc(self, instance: Instance<'tcx>) -> AllocId {
         // Functions cannot be identified by pointers, as asm-equal functions can get deduplicated
         // by the linker (we set the "unnamed_addr" attribute for LLVM) and functions can be
         // duplicated across crates.
@@ -507,7 +507,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Statics with identical content will still point to the same `Allocation`, i.e.,
     /// their data will be deduplicated through `Allocation` interning -- but they
     /// are different places in memory and as such need different IDs.
-    pub fn create_memory_alloc(&self, mem: &'tcx Allocation) -> AllocId {
+    pub fn create_memory_alloc(self, mem: &'tcx Allocation) -> AllocId {
         let id = self.reserve_alloc_id();
         self.set_alloc_id_memory(id, mem);
         id
@@ -519,7 +519,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// This function exists to allow const eval to detect the difference between evaluation-
     /// local dangling pointers and allocations in constants/statics.
     #[inline]
-    pub fn get_global_alloc(&self, id: AllocId) -> Option<GlobalAlloc<'tcx>> {
+    pub fn get_global_alloc(self, id: AllocId) -> Option<GlobalAlloc<'tcx>> {
         self.alloc_map.lock().alloc_map.get(&id).cloned()
     }
 
@@ -529,7 +529,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// constants (as all constants must pass interning and validation that check for dangling
     /// ids), this function is frequently used throughout rustc, but should not be used within
     /// the miri engine.
-    pub fn global_alloc(&self, id: AllocId) -> GlobalAlloc<'tcx> {
+    pub fn global_alloc(self, id: AllocId) -> GlobalAlloc<'tcx> {
         match self.get_global_alloc(id) {
             Some(alloc) => alloc,
             None => bug!("could not find allocation for {}", id),
@@ -538,15 +538,15 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Freezes an `AllocId` created with `reserve` by pointing it at an `Allocation`. Trying to
     /// call this function twice, even with the same `Allocation` will ICE the compiler.
-    pub fn set_alloc_id_memory(&self, id: AllocId, mem: &'tcx Allocation) {
+    pub fn set_alloc_id_memory(self, id: AllocId, mem: &'tcx Allocation) {
         if let Some(old) = self.alloc_map.lock().alloc_map.insert(id, GlobalAlloc::Memory(mem)) {
             bug!("tried to set allocation ID {}, but it was already existing as {:#?}", id, old);
         }
     }
 
     /// Freezes an `AllocId` created with `reserve` by pointing it at an `Allocation`. May be called
     /// twice for the same `(AllocId, Allocation)` pair.
-    fn set_alloc_id_same_memory(&self, id: AllocId, mem: &'tcx Allocation) {
+    fn set_alloc_id_same_memory(self, id: AllocId, mem: &'tcx Allocation) {
         self.alloc_map.lock().alloc_map.insert_same(id, GlobalAlloc::Memory(mem));
     }
 }

compiler/rustc_middle/src/ty/context.rs

@@ -1179,7 +1179,7 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_const(ty::Const { val: ty::ConstKind::Error(DelaySpanBugEmitted(())), ty })
     }
 
-    pub fn consider_optimizing<T: Fn() -> String>(&self, msg: T) -> bool {
+    pub fn consider_optimizing<T: Fn() -> String>(self, msg: T) -> bool {
         let cname = self.crate_name(LOCAL_CRATE).as_str();
         self.sess.consider_optimizing(&cname, msg)
     }
@@ -1403,7 +1403,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     // Returns the `DefId` and the `BoundRegion` corresponding to the given region.
-    pub fn is_suitable_region(&self, region: Region<'tcx>) -> Option<FreeRegionInfo> {
+    pub fn is_suitable_region(self, region: Region<'tcx>) -> Option<FreeRegionInfo> {
         let (suitable_region_binding_scope, bound_region) = match *region {
             ty::ReFree(ref free_region) => {
                 (free_region.scope.expect_local(), free_region.bound_region)
@@ -1433,7 +1433,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Given a `DefId` for an `fn`, return all the `dyn` and `impl` traits in its return type.
     pub fn return_type_impl_or_dyn_traits(
-        &self,
+        self,
         scope_def_id: LocalDefId,
     ) -> Vec<&'tcx hir::Ty<'tcx>> {
         let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id);
@@ -1479,7 +1479,7 @@ impl<'tcx> TyCtxt<'tcx> {
         v.0
     }
 
-    pub fn return_type_impl_trait(&self, scope_def_id: LocalDefId) -> Option<(Ty<'tcx>, Span)> {
+    pub fn return_type_impl_trait(self, scope_def_id: LocalDefId) -> Option<(Ty<'tcx>, Span)> {
         // HACK: `type_of_def_id()` will fail on these (#55796), so return `None`.
         let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id);
         match self.hir().get(hir_id) {
@@ -1497,7 +1497,7 @@ impl<'tcx> TyCtxt<'tcx> {
         let ret_ty = self.type_of(scope_def_id);
         match ret_ty.kind() {
             ty::FnDef(_, _) => {
-                let sig = ret_ty.fn_sig(*self);
+                let sig = ret_ty.fn_sig(self);
                 let output = self.erase_late_bound_regions(&sig.output());
                 if output.is_impl_trait() {
                     let fn_decl = self.hir().fn_decl_by_hir_id(hir_id).unwrap();
@@ -1511,7 +1511,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     // Checks if the bound region is in Impl Item.
-    pub fn is_bound_region_in_impl_item(&self, suitable_region_binding_scope: LocalDefId) -> bool {
+    pub fn is_bound_region_in_impl_item(self, suitable_region_binding_scope: LocalDefId) -> bool {
         let container_id =
             self.associated_item(suitable_region_binding_scope.to_def_id()).container.id();
         if self.impl_trait_ref(container_id).is_some() {
@@ -1528,21 +1528,21 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Determines whether identifiers in the assembly have strict naming rules.
     /// Currently, only NVPTX* targets need it.
-    pub fn has_strict_asm_symbol_naming(&self) -> bool {
+    pub fn has_strict_asm_symbol_naming(self) -> bool {
         self.sess.target.target.arch.contains("nvptx")
     }
 
     /// Returns `&'static core::panic::Location<'static>`.
-    pub fn caller_location_ty(&self) -> Ty<'tcx> {
+    pub fn caller_location_ty(self) -> Ty<'tcx> {
         self.mk_imm_ref(
             self.lifetimes.re_static,
             self.type_of(self.require_lang_item(LangItem::PanicLocation, None))
-                .subst(*self, self.mk_substs([self.lifetimes.re_static.into()].iter())),
+                .subst(self, self.mk_substs([self.lifetimes.re_static.into()].iter())),
         )
     }
 
     /// Returns a displayable description and article for the given `def_id` (e.g. `("a", "struct")`).
-    pub fn article_and_description(&self, def_id: DefId) -> (&'static str, &'static str) {
+    pub fn article_and_description(self, def_id: DefId) -> (&'static str, &'static str) {
         match self.def_kind(def_id) {
             DefKind::Generator => match self.generator_kind(def_id).unwrap() {
                 rustc_hir::GeneratorKind::Async(..) => ("an", "async closure"),

compiler/rustc_middle/src/ty/error.rs

@@ -546,22 +546,22 @@ impl<T> Trait<T> for X {
     }
 
     fn suggest_constraint(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         msg: &str,
         body_owner_def_id: DefId,
         proj_ty: &ty::ProjectionTy<'tcx>,
         ty: Ty<'tcx>,
     ) -> bool {
         let assoc = self.associated_item(proj_ty.item_def_id);
-        let trait_ref = proj_ty.trait_ref(*self);
+        let trait_ref = proj_ty.trait_ref(self);
         if let Some(item) = self.hir().get_if_local(body_owner_def_id) {
             if let Some(hir_generics) = item.generics() {
                 // Get the `DefId` for the type parameter corresponding to `A` in `<A as T>::Foo`.
                 // This will also work for `impl Trait`.
                 let def_id = if let ty::Param(param_ty) = proj_ty.self_ty().kind() {
                     let generics = self.generics_of(body_owner_def_id);
-                    generics.type_param(&param_ty, *self).def_id
+                    generics.type_param(param_ty, self).def_id
                 } else {
                     return false;
                 };
@@ -629,7 +629,7 @@ impl<T> Trait<T> for X {
     ///    and the `impl`, we provide a generic `help` to constrain the assoc type or call an assoc
     ///    fn that returns the type.
     fn expected_projection(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         proj_ty: &ty::ProjectionTy<'tcx>,
         values: &ExpectedFound<Ty<'tcx>>,
@@ -734,7 +734,7 @@ fn foo(&self) -> Self::T { String::new() }
     }
 
     fn point_at_methods_that_satisfy_associated_type(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         assoc_container_id: DefId,
         current_method_ident: Option<Symbol>,
@@ -789,7 +789,7 @@ fn foo(&self) -> Self::T { String::new() }
     }
 
     fn point_at_associated_type(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         body_owner_def_id: DefId,
         found: Ty<'tcx>,
@@ -851,7 +851,7 @@ fn foo(&self) -> Self::T { String::new() }
     /// Given a slice of `hir::GenericBound`s, if any of them corresponds to the `trait_ref`
     /// requirement, provide a strucuted suggestion to constrain it to a given type `ty`.
     fn constrain_generic_bound_associated_type_structured_suggestion(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         trait_ref: &ty::TraitRef<'tcx>,
         bounds: hir::GenericBounds<'_>,
@@ -875,7 +875,7 @@ fn foo(&self) -> Self::T { String::new() }
     /// Given a span corresponding to a bound, provide a structured suggestion to set an
     /// associated type to a given type `ty`.
     fn constrain_associated_type_structured_suggestion(
-        &self,
+        self,
         db: &mut DiagnosticBuilder<'_>,
         span: Span,
         assoc: &ty::AssocItem,

compiler/rustc_middle/src/ty/fold.rs

@@ -623,7 +623,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Replaces any late-bound regions bound in `value` with
     /// free variants attached to `all_outlive_scope`.
     pub fn liberate_late_bound_regions<T>(
-        &self,
+        self,
         all_outlive_scope: DefId,
         value: &ty::Binder<T>,
     ) -> T
@@ -644,7 +644,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// variables and equate `value` with something else, those
     /// variables will also be equated.
     pub fn collect_constrained_late_bound_regions<T>(
-        &self,
+        self,
         value: &Binder<T>,
     ) -> FxHashSet<ty::BoundRegion>
     where
@@ -655,7 +655,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Returns a set of all late-bound regions that appear in `value` anywhere.
     pub fn collect_referenced_late_bound_regions<T>(
-        &self,
+        self,
         value: &Binder<T>,
     ) -> FxHashSet<ty::BoundRegion>
     where
@@ -665,7 +665,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     fn collect_late_bound_regions<T>(
-        &self,
+        self,
         value: &Binder<T>,
         just_constraint: bool,
     ) -> FxHashSet<ty::BoundRegion>

compiler/rustc_middle/src/ty/util.rs

@@ -170,9 +170,7 @@ impl<'tcx> TyCtxt<'tcx> {
         });
         hasher.finish()
     }
-}
 
-impl<'tcx> TyCtxt<'tcx> {
     pub fn has_error_field(self, ty: Ty<'tcx>) -> bool {
         if let ty::Adt(def, substs) = *ty.kind() {
             for field in def.all_fields() {
@@ -526,22 +524,22 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     /// Returns `true` if the node pointed to by `def_id` is a `static` item.
-    pub fn is_static(&self, def_id: DefId) -> bool {
+    pub fn is_static(self, def_id: DefId) -> bool {
         self.static_mutability(def_id).is_some()
     }
 
     /// Returns `true` if this is a `static` item with the `#[thread_local]` attribute.
-    pub fn is_thread_local_static(&self, def_id: DefId) -> bool {
+    pub fn is_thread_local_static(self, def_id: DefId) -> bool {
         self.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::THREAD_LOCAL)
     }
 
     /// Returns `true` if the node pointed to by `def_id` is a mutable `static` item.
-    pub fn is_mutable_static(&self, def_id: DefId) -> bool {
+    pub fn is_mutable_static(self, def_id: DefId) -> bool {
         self.static_mutability(def_id) == Some(hir::Mutability::Mut)
     }
 
     /// Get the type of the pointer to the static that we use in MIR.
-    pub fn static_ptr_ty(&self, def_id: DefId) -> Ty<'tcx> {
+    pub fn static_ptr_ty(self, def_id: DefId) -> Ty<'tcx> {
         // Make sure that any constants in the static's type are evaluated.
         let static_ty = self.normalize_erasing_regions(ty::ParamEnv::empty(), self.type_of(def_id));