rust-lang · bors · Sep 21, 2023 · Sep 20, 2023
diff --git a/clippy_lints/src/default_union_representation.rs b/clippy_lints/src/default_union_representation.rs
@@ -1,8 +1,8 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use rustc_hir::{self as hir, HirId, Item, ItemKind};
-use rustc_hir_analysis::hir_ty_to_ty;
+use rustc_hir::{HirId, Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::{self, FieldDef, GenericArg, List};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 
@@ -52,7 +52,10 @@ declare_lint_pass!(DefaultUnionRepresentation => [DEFAULT_UNION_REPRESENTATION])
 
 impl<'tcx> LateLintPass<'tcx> for DefaultUnionRepresentation {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
-        if is_union_with_two_non_zst_fields(cx, item) && !has_c_repr_attr(cx, item.hir_id()) {
+        if !item.span.from_expansion()
+            && is_union_with_two_non_zst_fields(cx, item)
+            && !has_c_repr_attr(cx, item.hir_id())
+        {
             span_lint_and_help(
                 cx,
                 DEFAULT_UNION_REPRESENTATION,
@@ -73,18 +76,17 @@ impl<'tcx> LateLintPass<'tcx> for DefaultUnionRepresentation {
 /// if there is only one field left after ignoring ZST fields then the offset
 /// of that field does not matter either.)
 fn is_union_with_two_non_zst_fields(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
-    if let ItemKind::Union(data, _) = &item.kind {
-        data.fields().iter().filter(|f| !is_zst(cx, f.ty)).count() >= 2
+    if let ItemKind::Union(..) = &item.kind
+        && let ty::Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind()
+    {
+        adt_def.all_fields().filter(|f| !is_zst(cx, f, args)).count() >= 2
     } else {
         false
     }
 }
 
-fn is_zst(cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>) -> bool {
-    if hir_ty.span.from_expansion() {
-        return false;
-    }
-    let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+fn is_zst<'tcx>(cx: &LateContext<'tcx>, field: &FieldDef, args: &'tcx List<GenericArg<'tcx>>) -> bool {
+    let ty = field.ty(cx.tcx, args);
     if let Ok(layout) = cx.layout_of(ty) {
         layout.is_zst()
     } else {

diff --git a/clippy_lints/src/error_impl_error.rs b/clippy_lints/src/error_impl_error.rs
@@ -3,7 +3,6 @@ use clippy_utils::path_res;
 use clippy_utils::ty::implements_trait;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::{Item, ItemKind};
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::Visibility;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -42,9 +41,10 @@ impl<'tcx> LateLintPass<'tcx> for ErrorImplError {
         };
 
         match item.kind {
-            ItemKind::TyAlias(ty, _) if implements_trait(cx, hir_ty_to_ty(cx.tcx, ty), error_def_id, &[])
-                && item.ident.name == sym::Error
-                && is_visible_outside_module(cx, item.owner_id.def_id) =>
+            ItemKind::TyAlias(..) if item.ident.name == sym::Error
+                && is_visible_outside_module(cx, item.owner_id.def_id)
+                && let ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
+                && implements_trait(cx, ty, error_def_id, &[]) =>
             {
                 span_lint(
                     cx,

diff --git a/clippy_lints/src/large_const_arrays.rs b/clippy_lints/src/large_const_arrays.rs
@@ -2,7 +2,6 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{Item, ItemKind};
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::{self, ConstKind};
@@ -50,12 +49,12 @@ impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if_chain! {
             if !item.span.from_expansion();
-            if let ItemKind::Const(hir_ty, generics, _) = &item.kind;
+            if let ItemKind::Const(_, generics, _) = &item.kind;
             // Since static items may not have generics, skip generic const items.
             // FIXME(generic_const_items): I don't think checking `generics.hwcp` suffices as it
             // doesn't account for empty where-clauses that only consist of keyword `where` IINM.
             if generics.params.is_empty() && !generics.has_where_clause_predicates;
-            let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+            let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
             if let ty::Array(element_type, cst) = ty.kind();
             if let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind();
             if let Ok(element_count) = element_count.try_to_target_usize(cx.tcx);

diff --git a/clippy_lints/src/loops/utils.rs b/clippy_lints/src/loops/utils.rs
@@ -5,7 +5,6 @@ use rustc_ast::ast::{LitIntType, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, walk_local, walk_pat, walk_stmt, Visitor};
 use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, HirId, HirIdMap, Local, Mutability, Pat, PatKind, Stmt};
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty};
@@ -150,7 +149,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InitializeVisitor<'a, 'tcx> {
             if l.pat.hir_id == self.var_id;
             if let PatKind::Binding(.., ident, _) = l.pat.kind;
             then {
-                let ty = l.ty.map(|ty| hir_ty_to_ty(self.cx.tcx, ty));
+                let ty = l.ty.map(|_| self.cx.typeck_results().pat_ty(l.pat));
 
                 self.state = l.init.map_or(InitializeVisitorState::Declared(ident.name, ty), |init| {
                     InitializeVisitorState::Initialized {

diff --git a/clippy_lints/src/matches/needless_match.rs b/clippy_lints/src/matches/needless_match.rs
@@ -8,8 +8,7 @@ use clippy_utils::{
 };
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::OptionNone;
-use rustc_hir::{Arm, BindingAnnotation, ByRef, Expr, ExprKind, FnRetTy, Guard, Node, Pat, PatKind, Path, QPath};
-use rustc_hir_analysis::hir_ty_to_ty;
+use rustc_hir::{Arm, BindingAnnotation, ByRef, Expr, ExprKind, Guard, ItemKind, Node, Pat, PatKind, Path, QPath};
 use rustc_lint::LateContext;
 use rustc_span::sym;
 
@@ -141,11 +140,15 @@ fn expr_ty_matches_p_ty(cx: &LateContext<'_>, expr: &Expr<'_>, p_expr: &Expr<'_>
                 return same_type_and_consts(results.node_type(local.hir_id), results.expr_ty(expr));
             },
             // compare match_expr ty with RetTy in `fn foo() -> RetTy`
-            Node::Item(..) => {
-                if let Some(fn_decl) = p_node.fn_decl() {
-                    if let FnRetTy::Return(ret_ty) = fn_decl.output {
-                        return same_type_and_consts(hir_ty_to_ty(cx.tcx, ret_ty), cx.typeck_results().expr_ty(expr));
-                    }
+            Node::Item(item) => {
+                if let ItemKind::Fn(..) = item.kind {
+                    let output = cx
+                        .tcx
+                        .fn_sig(item.owner_id)
+                        .instantiate_identity()
+                        .output()
+                        .skip_binder();
+                    return same_type_and_consts(output, cx.typeck_results().expr_ty(expr));
                 }
             },
             // check the parent expr for this whole block `{ match match_expr {..} }`

diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
@@ -126,7 +126,6 @@ pub use path_ends_with_ext::DEFAULT_ALLOWED_DOTFILES;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::{Expr, ExprKind, Node, Stmt, StmtKind, TraitItem, TraitItemKind};
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::{self, TraitRef, Ty};
@@ -3926,18 +3925,20 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         if_chain! {
             if let TraitItemKind::Fn(ref sig, _) = item.kind;
             if sig.decl.implicit_self.has_implicit_self();
-            if let Some(first_arg_ty) = sig.decl.inputs.iter().next();
-
+            if let Some(first_arg_hir_ty) = sig.decl.inputs.first();
+            if let Some(&first_arg_ty) = cx.tcx.fn_sig(item.owner_id)
+                .instantiate_identity()
+                .inputs()
+                .skip_binder()
+                .first();
             then {
-                let first_arg_span = first_arg_ty.span;
-                let first_arg_ty = hir_ty_to_ty(cx.tcx, first_arg_ty);
                 let self_ty = TraitRef::identity(cx.tcx, item.owner_id.to_def_id()).self_ty();
                 wrong_self_convention::check(
                     cx,
                     item.ident.name.as_str(),
                     self_ty,
                     first_arg_ty,
-                    first_arg_span,
+                    first_arg_hir_ty.span,
                     false,
                     true,
                 );

diff --git a/clippy_lints/src/missing_const_for_fn.rs b/clippy_lints/src/missing_const_for_fn.rs
@@ -7,7 +7,6 @@ use rustc_hir as hir;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{Body, Constness, FnDecl, GenericParamKind};
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -124,7 +123,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
             FnKind::Method(_, sig, ..) => {
                 if trait_ref_of_method(cx, def_id).is_some()
                     || already_const(sig.header)
-                    || method_accepts_droppable(cx, sig.decl.inputs)
+                    || method_accepts_droppable(cx, def_id)
                 {
                     return;
                 }
@@ -165,12 +164,11 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
 
 /// Returns true if any of the method parameters is a type that implements `Drop`. The method
 /// can't be made const then, because `drop` can't be const-evaluated.
-fn method_accepts_droppable(cx: &LateContext<'_>, param_tys: &[hir::Ty<'_>]) -> bool {
+fn method_accepts_droppable(cx: &LateContext<'_>, def_id: LocalDefId) -> bool {
+    let sig = cx.tcx.fn_sig(def_id).instantiate_identity().skip_binder();
+
     // If any of the params are droppable, return true
-    param_tys.iter().any(|hir_ty| {
-        let ty_ty = hir_ty_to_ty(cx.tcx, hir_ty);
-        has_drop(cx, ty_ty)
-    })
+    sig.inputs().iter().any(|&ty| has_drop(cx, ty))
 }
 
 // We don't have to lint on something that's already `const`

diff --git a/clippy_lints/src/no_effect.rs b/clippy_lints/src/no_effect.rs
@@ -5,10 +5,8 @@ use clippy_utils::{get_parent_node, is_lint_allowed, peel_blocks};
 use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{
-    is_range_literal, BinOpKind, BlockCheckMode, Expr, ExprKind, FnRetTy, ItemKind, Node, PatKind, Stmt, StmtKind,
-    UnsafeSource,
+    is_range_literal, BinOpKind, BlockCheckMode, Expr, ExprKind, ItemKind, Node, PatKind, Stmt, StmtKind, UnsafeSource,
 };
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::TyCtxtInferExt as _;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
@@ -99,14 +97,13 @@ fn check_no_effect(cx: &LateContext<'_>, stmt: &Stmt<'_>) -> bool {
                 |diag| {
                     for parent in cx.tcx.hir().parent_iter(stmt.hir_id) {
                         if let Node::Item(item) = parent.1
-                            && let ItemKind::Fn(sig, ..) = item.kind
-                            && let FnRetTy::Return(ret_ty) = sig.decl.output
+                            && let ItemKind::Fn(..) = item.kind
                             && let Some(Node::Block(block)) = get_parent_node(cx.tcx, stmt.hir_id)
                             && let [.., final_stmt] = block.stmts
                             && final_stmt.hir_id == stmt.hir_id
                         {
                             let expr_ty = cx.typeck_results().expr_ty(expr);
-                            let mut ret_ty = hir_ty_to_ty(cx.tcx, ret_ty);
+                            let mut ret_ty = cx.tcx.fn_sig(item.owner_id).instantiate_identity().output().skip_binder();
 
                             // Remove `impl Future<Output = T>` to get `T`
                             if cx.tcx.ty_is_opaque_future(ret_ty) &&
@@ -115,7 +112,7 @@ fn check_no_effect(cx: &LateContext<'_>, stmt: &Stmt<'_>) -> bool {
                                 ret_ty = true_ret_ty;
                             }
 
-                            if ret_ty == expr_ty {
+                            if !ret_ty.is_unit() && ret_ty == expr_ty {
                                 diag.span_suggestion(
                                     stmt.span.shrink_to_lo(),
                                     "did you mean to return it?",

diff --git a/clippy_lints/src/non_canonical_impls.rs b/clippy_lints/src/non_canonical_impls.rs
@@ -4,8 +4,7 @@ use clippy_utils::ty::implements_trait;
 use clippy_utils::{get_parent_node, is_res_lang_ctor, last_path_segment, match_def_path, path_res, std_or_core};
 use rustc_errors::Applicability;
 use rustc_hir::def_id::LocalDefId;
-use rustc_hir::{Expr, ExprKind, ImplItem, ImplItemKind, ItemKind, LangItem, Node, UnOp};
-use rustc_hir_analysis::hir_ty_to_ty;
+use rustc_hir::{Expr, ExprKind, ImplItem, ImplItemKind, LangItem, Node, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::EarlyBinder;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -123,9 +122,6 @@ impl LateLintPass<'_> for NonCanonicalImpls {
         if cx.tcx.is_automatically_derived(item.owner_id.to_def_id()) {
             return;
         }
-        let ItemKind::Impl(imp) = item.kind else {
-            return;
-        };
         let ImplItemKind::Fn(_, impl_item_id) = cx.tcx.hir().impl_item(impl_item.impl_item_id()).kind else {
             return;
         };
@@ -181,12 +177,8 @@ impl LateLintPass<'_> for NonCanonicalImpls {
 
         if cx.tcx.is_diagnostic_item(sym::PartialOrd, trait_impl.def_id)
             && impl_item.ident.name == sym::partial_cmp
-            && let Some(ord_def_id) = cx
-                .tcx
-                .diagnostic_items(trait_impl.def_id.krate)
-                .name_to_id
-                .get(&sym::Ord)
-            && implements_trait(cx, hir_ty_to_ty(cx.tcx, imp.self_ty), *ord_def_id, &[])
+            && let Some(ord_def_id) = cx.tcx.get_diagnostic_item(sym::Ord)
+            && implements_trait(cx, trait_impl.self_ty(), ord_def_id, &[])
         {
             // If the `cmp` call likely needs to be fully qualified in the suggestion
             // (like `std::cmp::Ord::cmp`). It's unfortunate we must put this here but we can't

diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs
@@ -13,7 +13,6 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{
     BodyId, Expr, ExprKind, HirId, Impl, ImplItem, ImplItemKind, Item, ItemKind, Node, TraitItem, TraitItemKind, UnOp,
 };
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass, Lint};
 use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult, GlobalId};
 use rustc_middle::ty::adjustment::Adjust;
@@ -297,17 +296,17 @@ declare_lint_pass!(NonCopyConst => [DECLARE_INTERIOR_MUTABLE_CONST, BORROW_INTER
 
 impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
     fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx Item<'_>) {
-        if let ItemKind::Const(hir_ty, _generics, body_id) = it.kind {
-            let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+        if let ItemKind::Const(.., body_id) = it.kind {
+            let ty = cx.tcx.type_of(it.owner_id).instantiate_identity();
             if !ignored_macro(cx, it) && is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, body_id, ty) {
                 lint(cx, Source::Item { item: it.span });
             }
         }
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'tcx>, trait_item: &'tcx TraitItem<'_>) {
-        if let TraitItemKind::Const(hir_ty, body_id_opt) = &trait_item.kind {
-            let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+        if let TraitItemKind::Const(_, body_id_opt) = &trait_item.kind {
+            let ty = cx.tcx.type_of(trait_item.owner_id).instantiate_identity();
 
             // Normalize assoc types because ones originated from generic params
             // bounded other traits could have their bound.
@@ -333,7 +332,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
-        if let ImplItemKind::Const(hir_ty, body_id) = &impl_item.kind {
+        if let ImplItemKind::Const(_, body_id) = &impl_item.kind {
             let item_def_id = cx.tcx.hir().get_parent_item(impl_item.hir_id()).def_id;
             let item = cx.tcx.hir().expect_item(item_def_id);
 
@@ -366,7 +365,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
                             // we should use here as a frozen variant is a potential to be frozen
                             // similar to unknown layouts.
                             // e.g. `layout_of(...).is_err() || has_frozen_variant(...);`
-                        let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+                        let ty = cx.tcx.type_of(impl_item.owner_id).instantiate_identity();
                         let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
                         if is_unfrozen(cx, normalized);
                         if is_value_unfrozen_poly(cx, *body_id, normalized);
@@ -381,7 +380,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
                     }
                 },
                 ItemKind::Impl(Impl { of_trait: None, .. }) => {
-                    let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+                    let ty = cx.tcx.type_of(impl_item.owner_id).instantiate_identity();
                     // Normalize assoc types originated from generic params.
                     let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
 

diff --git a/clippy_lints/src/ptr.rs b/clippy_lints/src/ptr.rs
@@ -16,7 +16,6 @@ use rustc_hir::{
     ImplItemKind, ItemKind, Lifetime, Mutability, Node, Param, PatKind, QPath, TraitFn, TraitItem, TraitItemKind,
     TyKind, Unsafety,
 };
-use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{Obligation, ObligationCause};
 use rustc_lint::{LateContext, LateLintPass};
@@ -172,13 +171,8 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
 
             for arg in check_fn_args(
                 cx,
-                cx.tcx
-                    .fn_sig(item.owner_id)
-                    .instantiate_identity()
-                    .skip_binder()
-                    .inputs(),
+                cx.tcx.fn_sig(item.owner_id).instantiate_identity().skip_binder(),
                 sig.decl.inputs,
-                &sig.decl.output,
                 &[],
             )
             .filter(|arg| arg.mutability() == Mutability::Not)
@@ -237,7 +231,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
 
         let decl = sig.decl;
         let sig = cx.tcx.fn_sig(item_id).instantiate_identity().skip_binder();
-        let lint_args: Vec<_> = check_fn_args(cx, sig.inputs(), decl.inputs, &decl.output, body.params)
+        let lint_args: Vec<_> = check_fn_args(cx, sig, decl.inputs, body.params)
             .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not)
             .collect();
         let results = check_ptr_arg_usage(cx, body, &lint_args);
@@ -443,12 +437,13 @@ impl<'tcx> DerefTy<'tcx> {
 #[expect(clippy::too_many_lines)]
 fn check_fn_args<'cx, 'tcx: 'cx>(
     cx: &'cx LateContext<'tcx>,
-    tys: &'tcx [Ty<'tcx>],
+    fn_sig: ty::FnSig<'tcx>,
     hir_tys: &'tcx [hir::Ty<'tcx>],
-    ret_ty: &'tcx FnRetTy<'tcx>,
     params: &'tcx [Param<'tcx>],
 ) -> impl Iterator<Item = PtrArg<'tcx>> + 'cx {
-    tys.iter()
+    fn_sig
+        .inputs()
+        .iter()
         .zip(hir_tys.iter())
         .enumerate()
         .filter_map(move |(i, (ty, hir_ty))| {
@@ -494,9 +489,7 @@ fn check_fn_args<'cx, 'tcx: 'cx>(
                                 })
                             {
                                 if !lifetime.is_anonymous()
-                                    && let FnRetTy::Return(ret_ty) = ret_ty
-                                    && let ret_ty = hir_ty_to_ty(cx.tcx, ret_ty)
-                                    && ret_ty
+                                    && fn_sig.output()
                                         .walk()
                                         .filter_map(|arg| {
                                             arg.as_region().and_then(|lifetime| {