Introduce is_lang_ctor

Author: camsteffen

clippy_lints/src/collapsible_match.rs

@@ -1,11 +1,11 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::visitors::LocalUsedVisitor;
-use clippy_utils::{path_to_local, SpanlessEq};
+use clippy_utils::{is_lang_ctor, path_to_local, SpanlessEq};
 use if_chain::if_chain;
-use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
-use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind, QPath, StmtKind, UnOp};
+use rustc_hir::LangItem::OptionNone;
+use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind, StmtKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{DefIdTree, TyCtxt, TypeckResults};
+use rustc_middle::ty::TypeckResults;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{MultiSpan, Span};
 
@@ -52,7 +52,7 @@ declare_lint_pass!(CollapsibleMatch => [COLLAPSIBLE_MATCH]);
 impl<'tcx> LateLintPass<'tcx> for CollapsibleMatch {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) {
         if let ExprKind::Match(_expr, arms, _source) = expr.kind {
-            if let Some(wild_arm) = arms.iter().rfind(|arm| arm_is_wild_like(arm, cx.tcx)) {
+            if let Some(wild_arm) = arms.iter().rfind(|arm| arm_is_wild_like(cx, arm)) {
                 for arm in arms {
                     check_arm(arm, wild_arm, cx);
                 }
@@ -75,7 +75,7 @@ fn check_arm<'tcx>(arm: &Arm<'tcx>, wild_outer_arm: &Arm<'tcx>, cx: &LateContext
         // match <local> { .. }
         if let Some(binding_id) = path_to_local(strip_ref_operators(expr_in, cx.typeck_results()));
         // one of the branches must be "wild-like"
-        if let Some(wild_inner_arm_idx) = arms_inner.iter().rposition(|arm_inner| arm_is_wild_like(arm_inner, cx.tcx));
+        if let Some(wild_inner_arm_idx) = arms_inner.iter().rposition(|arm_inner| arm_is_wild_like(cx, arm_inner));
         let (wild_inner_arm, non_wild_inner_arm) =
             (&arms_inner[wild_inner_arm_idx], &arms_inner[1 - wild_inner_arm_idx]);
         if !pat_contains_or(non_wild_inner_arm.pat);
@@ -126,13 +126,13 @@ fn strip_singleton_blocks<'hir>(mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir>
 /// A "wild-like" pattern is wild ("_") or `None`.
 /// For this lint to apply, both the outer and inner match expressions
 /// must have "wild-like" branches that can be combined.
-fn arm_is_wild_like(arm: &Arm<'_>, tcx: TyCtxt<'_>) -> bool {
+fn arm_is_wild_like(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
     if arm.guard.is_some() {
         return false;
     }
     match arm.pat.kind {
         PatKind::Binding(..) | PatKind::Wild => true,
-        PatKind::Path(QPath::Resolved(None, path)) if is_none_ctor(path.res, tcx) => true,
+        PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
         _ => false,
     }
 }
@@ -164,17 +164,6 @@ fn pat_contains_or(pat: &Pat<'_>) -> bool {
     result
 }
 
-fn is_none_ctor(res: Res, tcx: TyCtxt<'_>) -> bool {
-    if let Some(none_id) = tcx.lang_items().option_none_variant() {
-        if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), id) = res {
-            if let Some(variant_id) = tcx.parent(id) {
-                return variant_id == none_id;
-            }
-        }
-    }
-    false
-}
-
 /// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is
 /// dereferenced. An overloaded deref such as `Vec` to slice would not be removed.
 fn strip_ref_operators<'hir>(mut expr: &'hir Expr<'hir>, typeck_results: &TypeckResults<'_>) -> &'hir Expr<'hir> {

clippy_lints/src/if_then_some_else_none.rs

@@ -1,7 +1,8 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::source::snippet_with_macro_callsite;
-use clippy_utils::{match_qpath, meets_msrv, parent_node_is_if_expr};
+use clippy_utils::{is_lang_ctor, meets_msrv, parent_node_is_if_expr};
 use if_chain::if_chain;
+use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
@@ -77,12 +78,12 @@ impl LateLintPass<'_> for IfThenSomeElseNone {
             if let Some(then_expr) = then_block.expr;
             if let ExprKind::Call(then_call, [then_arg]) = then_expr.kind;
             if let ExprKind::Path(ref then_call_qpath) = then_call.kind;
-            if match_qpath(then_call_qpath, &clippy_utils::paths::OPTION_SOME);
+            if is_lang_ctor(cx, then_call_qpath, OptionSome);
             if let ExprKind::Block(els_block, _) = els.kind;
             if els_block.stmts.is_empty();
             if let Some(els_expr) = els_block.expr;
-            if let ExprKind::Path(ref els_call_qpath) = els_expr.kind;
-            if match_qpath(els_call_qpath, &clippy_utils::paths::OPTION_NONE);
+            if let ExprKind::Path(ref qpath) = els_expr.kind;
+            if is_lang_ctor(cx, qpath, OptionNone);
             then {
                 let cond_snip = snippet_with_macro_callsite(cx, cond.span, "[condition]");
                 let cond_snip = if matches!(cond.kind, ExprKind::Unary(_, _) | ExprKind::Binary(_, _, _)) {

clippy_lints/src/loops/manual_flatten.rs

@@ -1,10 +1,11 @@
 use super::utils::make_iterator_snippet;
 use super::MANUAL_FLATTEN;
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::{is_ok_ctor, is_some_ctor, path_to_local_id};
+use clippy_utils::{is_lang_ctor, path_to_local_id};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, MatchSource, Pat, PatKind, QPath, StmtKind};
+use rustc_hir::LangItem::{OptionSome, ResultOk};
+use rustc_hir::{Expr, ExprKind, MatchSource, Pat, PatKind, StmtKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::source_map::Span;
@@ -42,9 +43,9 @@ pub(super) fn check<'tcx>(
             if let PatKind::Binding(_, pat_hir_id, _, _) = pat.kind;
             if path_to_local_id(match_expr, pat_hir_id);
             // Ensure the `if let` statement is for the `Some` variant of `Option` or the `Ok` variant of `Result`
-            if let PatKind::TupleStruct(QPath::Resolved(None, path), _, _) = match_arms[0].pat.kind;
-            let some_ctor = is_some_ctor(cx, path.res);
-            let ok_ctor = is_ok_ctor(cx, path.res);
+            if let PatKind::TupleStruct(ref qpath, _, _) = match_arms[0].pat.kind;
+            let some_ctor = is_lang_ctor(cx, qpath, OptionSome);
+            let ok_ctor = is_lang_ctor(cx, qpath, ResultOk);
             if some_ctor || ok_ctor;
             then {
                 let if_let_type = if some_ctor { "Some" } else { "Ok" };

clippy_lints/src/manual_map.rs

@@ -2,9 +2,10 @@ use crate::{map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF};
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::ty::{can_partially_move_ty, is_type_diagnostic_item, peel_mid_ty_refs_is_mutable};
-use clippy_utils::{in_constant, is_allowed, is_else_clause, match_def_path, match_var, paths, peel_hir_expr_refs};
+use clippy_utils::{in_constant, is_allowed, is_else_clause, is_lang_ctor, match_var, peel_hir_expr_refs};
 use rustc_ast::util::parser::PREC_POSTFIX;
 use rustc_errors::Applicability;
+use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{
     def::Res,
     intravisit::{walk_expr, ErasedMap, NestedVisitorMap, Visitor},
@@ -269,20 +270,9 @@ fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxCon
         match pat.kind {
             PatKind::Wild => Some(OptionPat::Wild),
             PatKind::Ref(pat, _) => f(cx, pat, ref_count + 1, ctxt),
-            PatKind::Path(QPath::Resolved(None, path))
-                if path
-                    .res
-                    .opt_def_id()
-                    .map_or(false, |id| match_def_path(cx, id, &paths::OPTION_NONE)) =>
-            {
-                Some(OptionPat::None)
-            },
-            PatKind::TupleStruct(QPath::Resolved(None, path), [pattern], _)
-                if path
-                    .res
-                    .opt_def_id()
-                    .map_or(false, |id| match_def_path(cx, id, &paths::OPTION_SOME))
-                    && pat.span.ctxt() == ctxt =>
+            PatKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone) => Some(OptionPat::None),
+            PatKind::TupleStruct(ref qpath, [pattern], _)
+                if is_lang_ctor(cx, qpath, OptionSome) && pat.span.ctxt() == ctxt =>
             {
                 Some(OptionPat::Some { pattern, ref_count })
             },
@@ -298,17 +288,11 @@ fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ctxt: SyntaxConte
     match expr.kind {
         ExprKind::Call(
             Expr {
-                kind: ExprKind::Path(QPath::Resolved(None, path)),
+                kind: ExprKind::Path(ref qpath),
                 ..
             },
             [arg],
-        ) if ctxt == expr.span.ctxt() => {
-            if match_def_path(cx, path.res.opt_def_id()?, &paths::OPTION_SOME) {
-                Some(arg)
-            } else {
-                None
-            }
-        },
+        ) if ctxt == expr.span.ctxt() && is_lang_ctor(cx, qpath, OptionSome) => Some(arg),
         ExprKind::Block(
             Block {
                 stmts: [],
@@ -324,10 +308,7 @@ fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ctxt: SyntaxConte
 // Checks for the `None` value.
 fn is_none_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
     match expr.kind {
-        ExprKind::Path(QPath::Resolved(None, path)) => path
-            .res
-            .opt_def_id()
-            .map_or(false, |id| match_def_path(cx, id, &paths::OPTION_NONE)),
+        ExprKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
         ExprKind::Block(
             Block {
                 stmts: [],

clippy_lints/src/manual_ok_or.rs

@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{indent_of, reindent_multiline, snippet_opt};
 use clippy_utils::ty::is_type_diagnostic_item;
-use clippy_utils::{match_qpath, path_to_local_id, paths};
+use clippy_utils::{is_lang_ctor, path_to_local_id};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
+use rustc_hir::LangItem::{ResultErr, ResultOk};
 use rustc_hir::{Expr, ExprKind, PatKind};
 use rustc_lint::LintContext;
 use rustc_lint::{LateContext, LateLintPass};
@@ -54,7 +55,7 @@ impl LateLintPass<'_> for ManualOkOr {
             let or_expr = &args[1];
             if is_ok_wrapping(cx, &args[2]);
             if let ExprKind::Call(Expr { kind: ExprKind::Path(err_path), .. }, &[ref err_arg]) = or_expr.kind;
-            if match_qpath(err_path, &paths::RESULT_ERR);
+            if is_lang_ctor(cx, err_path, ResultErr);
             if let Some(method_receiver_snippet) = snippet_opt(cx, method_receiver.span);
             if let Some(err_arg_snippet) = snippet_opt(cx, err_arg.span);
             if let Some(indent) = indent_of(cx, scrutinee.span);
@@ -81,7 +82,7 @@ impl LateLintPass<'_> for ManualOkOr {
 
 fn is_ok_wrapping(cx: &LateContext<'_>, map_expr: &Expr<'_>) -> bool {
     if let ExprKind::Path(ref qpath) = map_expr.kind {
-        if match_qpath(qpath, &paths::RESULT_OK) {
+        if is_lang_ctor(cx, qpath, ResultOk) {
             return true;
         }
     }
@@ -90,7 +91,7 @@ fn is_ok_wrapping(cx: &LateContext<'_>, map_expr: &Expr<'_>) -> bool {
         let body = cx.tcx.hir().body(body_id);
         if let PatKind::Binding(_, param_id, ..) = body.params[0].pat.kind;
         if let ExprKind::Call(Expr { kind: ExprKind::Path(ok_path), .. }, &[ref ok_arg]) = body.value.kind;
-        if match_qpath(ok_path, &paths::RESULT_OK);
+        if is_lang_ctor(cx, ok_path, ResultOk);
         then { path_to_local_id(ok_arg, param_id) } else { false }
     }
 }

clippy_lints/src/manual_unwrap_or.rs

@@ -3,10 +3,11 @@ use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{indent_of, reindent_multiline, snippet_opt};
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::usage::contains_return_break_continue_macro;
-use clippy_utils::{in_constant, match_qpath, path_to_local_id, paths, sugg};
+use clippy_utils::{in_constant, is_lang_ctor, path_to_local_id, sugg};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, Expr, ExprKind, Pat, PatKind};
+use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr, ResultOk};
+use rustc_hir::{Arm, Expr, ExprKind, PatKind};
 use rustc_lint::LintContext;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
@@ -68,23 +69,21 @@ impl Case {
 }
 
 fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
-    fn applicable_or_arm<'a>(arms: &'a [Arm<'a>]) -> Option<&'a Arm<'a>> {
+    fn applicable_or_arm<'a>(cx: &LateContext<'_>, arms: &'a [Arm<'a>]) -> Option<&'a Arm<'a>> {
         if_chain! {
             if arms.len() == 2;
             if arms.iter().all(|arm| arm.guard.is_none());
-            if let Some((idx, or_arm)) = arms.iter().enumerate().find(|(_, arm)|
+            if let Some((idx, or_arm)) = arms.iter().enumerate().find(|(_, arm)| {
                 match arm.pat.kind {
-                    PatKind::Path(ref some_qpath) =>
-                        match_qpath(some_qpath, &paths::OPTION_NONE),
-                    PatKind::TupleStruct(ref err_qpath, &[Pat { kind: PatKind::Wild, .. }], _) =>
-                        match_qpath(err_qpath, &paths::RESULT_ERR),
+                    PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
+                    PatKind::TupleStruct(ref qpath, &[pat], _) =>
+                        matches!(pat.kind, PatKind::Wild) && is_lang_ctor(cx, qpath, ResultErr),
                     _ => false,
                 }
-            );
+            });
             let unwrap_arm = &arms[1 - idx];
-            if let PatKind::TupleStruct(ref unwrap_qpath, &[unwrap_pat], _) = unwrap_arm.pat.kind;
-            if match_qpath(unwrap_qpath, &paths::OPTION_SOME)
-                || match_qpath(unwrap_qpath, &paths::RESULT_OK);
+            if let PatKind::TupleStruct(ref qpath, &[unwrap_pat], _) = unwrap_arm.pat.kind;
+            if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk);
             if let PatKind::Binding(_, binding_hir_id, ..) = unwrap_pat.kind;
             if path_to_local_id(unwrap_arm.body, binding_hir_id);
             if !contains_return_break_continue_macro(or_arm.body);
@@ -106,7 +105,7 @@ fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         } else {
             None
         };
-        if let Some(or_arm) = applicable_or_arm(match_arms);
+        if let Some(or_arm) = applicable_or_arm(cx, match_arms);
         if let Some(or_body_snippet) = snippet_opt(cx, or_arm.body.span);
         if let Some(indent) = indent_of(cx, expr.span);
         if constant_simple(cx, cx.typeck_results(), or_arm.body).is_some();

clippy_lints/src/matches.rs

@@ -7,14 +7,15 @@ use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item, match_type, peel_mid_ty_refs};
 use clippy_utils::visitors::LocalUsedVisitor;
 use clippy_utils::{
-    get_parent_expr, in_macro, is_allowed, is_expn_of, is_refutable, is_wild, match_qpath, meets_msrv, path_to_local,
+    get_parent_expr, in_macro, is_allowed, is_expn_of, is_lang_ctor, is_refutable, is_wild, meets_msrv, path_to_local,
     path_to_local_id, peel_hir_pat_refs, peel_n_hir_expr_refs, recurse_or_patterns, remove_blocks, strip_pat_refs,
 };
 use clippy_utils::{paths, search_same, SpanlessEq, SpanlessHash};
 use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::def::{CtorKind, DefKind, Res};
+use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{
     self as hir, Arm, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, Guard, HirId, Local, MatchSource,
     Mutability, Node, Pat, PatKind, PathSegment, QPath, RangeEnd, TyKind,
@@ -1188,10 +1189,10 @@ fn check_match_ref_pats(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], e
 
 fn check_match_as_ref(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
     if arms.len() == 2 && arms[0].guard.is_none() && arms[1].guard.is_none() {
-        let arm_ref: Option<BindingAnnotation> = if is_none_arm(&arms[0]) {
-            is_ref_some_arm(&arms[1])
-        } else if is_none_arm(&arms[1]) {
-            is_ref_some_arm(&arms[0])
+        let arm_ref: Option<BindingAnnotation> = if is_none_arm(cx, &arms[0]) {
+            is_ref_some_arm(cx, &arms[1])
+        } else if is_none_arm(cx, &arms[1]) {
+            is_ref_some_arm(cx, &arms[0])
         } else {
             None
         };
@@ -1574,20 +1575,20 @@ fn is_unit_expr(expr: &Expr<'_>) -> bool {
 }
 
 // Checks if arm has the form `None => None`
-fn is_none_arm(arm: &Arm<'_>) -> bool {
-    matches!(arm.pat.kind, PatKind::Path(ref path) if match_qpath(path, &paths::OPTION_NONE))
+fn is_none_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
+    matches!(arm.pat.kind, PatKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone))
 }
 
 // Checks if arm has the form `Some(ref v) => Some(v)` (checks for `ref` and `ref mut`)
-fn is_ref_some_arm(arm: &Arm<'_>) -> Option<BindingAnnotation> {
+fn is_ref_some_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> Option<BindingAnnotation> {
     if_chain! {
-        if let PatKind::TupleStruct(ref path, pats, _) = arm.pat.kind;
-        if pats.len() == 1 && match_qpath(path, &paths::OPTION_SOME);
+        if let PatKind::TupleStruct(ref qpath, pats, _) = arm.pat.kind;
+        if is_lang_ctor(cx, qpath, OptionSome);
         if let PatKind::Binding(rb, .., ident, _) = pats[0].kind;
         if rb == BindingAnnotation::Ref || rb == BindingAnnotation::RefMut;
         if let ExprKind::Call(e, args) = remove_blocks(arm.body).kind;
         if let ExprKind::Path(ref some_path) = e.kind;
-        if match_qpath(some_path, &paths::OPTION_SOME) && args.len() == 1;
+        if is_lang_ctor(cx, some_path, OptionSome) && args.len() == 1;
         if let ExprKind::Path(QPath::Resolved(_, path2)) = args[0].kind;
         if path2.segments.len() == 1 && ident.name == path2.segments[0].ident.name;
         then {
@@ -1699,10 +1700,11 @@ mod redundant_pattern_match {
     use super::REDUNDANT_PATTERN_MATCHING;
     use clippy_utils::diagnostics::span_lint_and_then;
     use clippy_utils::source::snippet;
-    use clippy_utils::{is_trait_method, match_qpath, paths};
+    use clippy_utils::{is_lang_ctor, is_trait_method, match_qpath, paths};
     use if_chain::if_chain;
     use rustc_ast::ast::LitKind;
     use rustc_errors::Applicability;
+    use rustc_hir::LangItem::{OptionNone, OptionSome, PollPending, PollReady, ResultErr, ResultOk};
     use rustc_hir::{Arm, Expr, ExprKind, MatchSource, PatKind, QPath};
     use rustc_lint::LateContext;
     use rustc_span::sym;
@@ -1734,13 +1736,13 @@ mod redundant_pattern_match {
         let good_method = match kind {
             PatKind::TupleStruct(ref path, patterns, _) if patterns.len() == 1 => {
                 if let PatKind::Wild = patterns[0].kind {
-                    if match_qpath(path, &paths::RESULT_OK) {
+                    if is_lang_ctor(cx, path, ResultOk) {
                         "is_ok()"
-                    } else if match_qpath(path, &paths::RESULT_ERR) {
+                    } else if is_lang_ctor(cx, path, ResultErr) {
                         "is_err()"
-                    } else if match_qpath(path, &paths::OPTION_SOME) {
+                    } else if is_lang_ctor(cx, path, OptionSome) {
                         "is_some()"
-                    } else if match_qpath(path, &paths::POLL_READY) {
+                    } else if is_lang_ctor(cx, path, PollReady) {
                         "is_ready()"
                     } else if match_qpath(path, &paths::IPADDR_V4) {
                         "is_ipv4()"
@@ -1754,9 +1756,9 @@ mod redundant_pattern_match {
                 }
             },
             PatKind::Path(ref path) => {
-                if match_qpath(path, &paths::OPTION_NONE) {
+                if is_lang_ctor(cx, path, OptionNone) {
                     "is_none()"
-                } else if match_qpath(path, &paths::POLL_PENDING) {
+                } else if is_lang_ctor(cx, path, PollPending) {
                     "is_pending()"
                 } else {
                     return;