Remove QPath::LangItem

Author: camsteffen

clippy_lints/src/arbitrary_source_item_ordering.rs

@@ -550,7 +550,6 @@ fn get_item_name(item: &Item<'_>) -> Option<String> {
                         // This case doesn't exist in the clippy tests codebase.
                         None
                     },
-                    QPath::LangItem(_, _) => None,
                 }
             } else {
                 // Impls for anything that isn't a named type can be skipped.

clippy_lints/src/incompatible_msrv.rs

@@ -4,7 +4,7 @@ use clippy_utils::msrvs::Msrv;
 use clippy_utils::{is_in_const_context, is_in_test};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
-use rustc_hir::{self as hir, AmbigArg, Expr, ExprKind, HirId, QPath, RustcVersion, StabilityLevel, StableSince};
+use rustc_hir::{self as hir, AmbigArg, Expr, ExprKind, HirId, RustcVersion, StabilityLevel, StableSince};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::impl_lint_pass;
@@ -193,10 +193,7 @@ impl<'tcx> LateLintPass<'tcx> for IncompatibleMsrv {
                     self.emit_lint_if_under_msrv(cx, method_did, expr.hir_id, span);
                 }
             },
-            // Desugaring into function calls by the compiler will use `QPath::LangItem` variants. Those should
-            // not be linted as they will not be generated in older compilers if the function is not available,
-            // and the compiler is allowed to call unstable functions.
-            ExprKind::Path(qpath @ (QPath::Resolved(..) | QPath::TypeRelative(..))) => {
+            ExprKind::Path(qpath) => {
                 if let Some(path_def_id) = cx.qpath_res(&qpath, expr.hir_id).opt_def_id() {
                     self.emit_lint_if_under_msrv(cx, path_def_id, expr.hir_id, expr.span);
                 }
@@ -206,7 +203,7 @@ impl<'tcx> LateLintPass<'tcx> for IncompatibleMsrv {
     }
 
     fn check_ty(&mut self, cx: &LateContext<'tcx>, hir_ty: &'tcx hir::Ty<'tcx, AmbigArg>) {
-        if let hir::TyKind::Path(qpath @ (QPath::Resolved(..) | QPath::TypeRelative(..))) = hir_ty.kind
+        if let hir::TyKind::Path(qpath) = hir_ty.kind
             && let Some(ty_def_id) = cx.qpath_res(&qpath, hir_ty.hir_id).opt_def_id()
             // `CStr` and `CString` have been moved around but have been available since Rust 1.0.0
             && !matches!(cx.tcx.get_diagnostic_name(ty_def_id), Some(sym::cstr_type | sym::cstring_type))

clippy_lints/src/methods/unnecessary_fallible_conversions.rs

@@ -181,7 +181,6 @@ pub(super) fn check_function(cx: &LateContext<'_>, expr: &Expr<'_>, callee: &Exp
             QPath::TypeRelative(_, seg) => Some(SpansKind::Fn {
                 fn_span: seg.ident.span,
             }),
-            QPath::LangItem(_, _) => unreachable!("`TryFrom` and `TryInto` are not lang items"),
         };
 
         check(

clippy_lints/src/redundant_type_annotations.rs

@@ -97,7 +97,6 @@ fn extract_fn_ty<'tcx>(
         // let a: String = String::new();
         // let a: String = String::get_string();
         hir::QPath::TypeRelative(..) => func_hir_id_to_func_ty(cx, call.hir_id),
-        hir::QPath::LangItem(..) => None,
     }
 }
 

clippy_lints/src/types/mod.rs

@@ -655,7 +655,6 @@ impl Types {
                             }
                         }
                     },
-                    QPath::LangItem(..) => {},
                 }
             },
             TyKind::Path(ref qpath) => {

clippy_lints/src/unconditional_recursion.rs

@@ -106,7 +106,6 @@ fn get_hir_ty_def_id<'tcx>(tcx: TyCtxt<'tcx>, hir_ty: rustc_hir::Ty<'tcx>) -> Op
                 _ => None,
             }
         },
-        QPath::LangItem(..) => None,
     }
 }
 
@@ -291,7 +290,6 @@ fn is_default_method_on_current_ty<'tcx>(tcx: TyCtxt<'tcx>, qpath: QPath<'tcx>,
             }
             get_hir_ty_def_id(tcx, *ty) == Some(implemented_ty_id)
         },
-        QPath::LangItem(..) => false,
     }
 }
 

clippy_lints/src/unnecessary_map_on_constructor.rs

@@ -60,7 +60,6 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryMapOnConstructor {
                     }
                 },
                 hir::QPath::TypeRelative(_, path) => path.ident.name,
-                hir::QPath::LangItem(..) => return,
             };
             match constructor_symbol {
                 sym::Some | sym::Ok if path.ident.name == sym::map => (),

clippy_lints/src/utils/author.rs

@@ -270,9 +270,7 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
     }
 
     fn qpath(&self, qpath: &Binding<&QPath<'_>>, hir_id_binding: &str, hir_id: HirId) {
-        if let QPath::LangItem(lang_item, ..) = *qpath.value {
-            chain!(self, "matches!({qpath}, QPath::LangItem(LangItem::{lang_item:?}, _))");
-        } else if let Some(def_id) = self.cx.qpath_res(qpath.value, hir_id).opt_def_id()
+        if let Some(def_id) = self.cx.qpath_res(qpath.value, hir_id).opt_def_id()
             && !def_id.is_local()
         {
             bind!(self, def_id);

clippy_utils/src/check_proc_macro.rs

@@ -121,7 +121,6 @@ fn qpath_search_pat(path: &QPath<'_>) -> (Pat, Pat) {
             (start, end)
         },
         QPath::TypeRelative(_, name) => (Pat::Str(""), Pat::Sym(name.ident.name)),
-        QPath::LangItem(..) => (Pat::Str(""), Pat::Str("")),
     }
 }
 

clippy_utils/src/eager_or_lazy.rs

@@ -167,7 +167,6 @@ fn expr_eagerness<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> EagernessS
                         QPath::TypeRelative(_, name) => {
                             self.eagerness |= fn_eagerness(self.cx, id, name.ident.name, !args.is_empty());
                         },
-                        QPath::LangItem(..) => self.eagerness = Lazy,
                     },
                     _ => self.eagerness = Lazy,
                 },