introduce as_some_expr, is_none_expr

clippy_lints/src/if_then_some_else_none.rs

@@ -2,14 +2,13 @@ use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::eager_or_lazy::switch_to_eager_eval;
 use clippy_utils::msrvs::{self, Msrv};
-use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context, walk_span_to_context};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{
-    contains_return, expr_adjustment_requires_coercion, higher, is_else_clause, is_in_const_context, peel_blocks, sym,
+    as_some_expr, contains_return, expr_adjustment_requires_coercion, higher, is_else_clause, is_in_const_context,
+    is_none_expr, peel_blocks, sym,
 };
 use rustc_errors::Applicability;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::impl_lint_pass;
@@ -70,11 +69,10 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
         }) = higher::If::hir(expr)
             && let ExprKind::Block(then_block, _) = then.kind
             && let Some(then_expr) = then_block.expr
-            && let ExprKind::Call(then_call, [then_arg]) = then_expr.kind
+            && let Some(then_arg) = as_some_expr(cx, then_expr)
             && !expr.span.from_expansion()
             && !then_expr.span.from_expansion()
-            && then_call.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
-            && peel_blocks(els).res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone)
+            && is_none_expr(cx, peel_blocks(els))
             && !is_else_clause(cx.tcx, expr)
             && !is_in_const_context(cx)
             && self.msrv.meets(cx, msrvs::BOOL_THEN)

clippy_lints/src/loops/manual_find.rs

@@ -5,7 +5,7 @@ use clippy_utils::res::{MaybeDef, MaybeQPath, MaybeResPath};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::implements_trait;
 use clippy_utils::usage::contains_return_break_continue_macro;
-use clippy_utils::{higher, peel_blocks_with_stmt};
+use clippy_utils::{as_some_expr, higher, peel_blocks_with_stmt};
 use rustc_errors::Applicability;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{BindingMode, Block, Expr, ExprKind, HirId, Node, Pat, PatKind, Stmt, StmtKind};
@@ -33,8 +33,7 @@ pub(super) fn check<'tcx>(
         && let [stmt] = block.stmts
         && let StmtKind::Semi(semi) = stmt.kind
         && let ExprKind::Ret(Some(ret_value)) = semi.kind
-        && let ExprKind::Call(ctor, [inner_ret]) = ret_value.kind
-        && ctor.res(cx).ctor_parent(cx).is_lang_item(cx, LangItem::OptionSome)
+        && let Some(inner_ret) = as_some_expr(cx, ret_value)
         && inner_ret.res_local_id() == Some(binding_id)
         && !contains_return_break_continue_macro(cond)
         && let Some((last_stmt, last_ret)) = last_stmt_and_ret(cx, expr)

clippy_lints/src/matches/manual_filter.rs

@@ -1,8 +1,9 @@
+use clippy_utils::as_some_expr;
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::res::{MaybeDef, MaybeQPath, MaybeResPath};
 use clippy_utils::visitors::contains_unsafe_block;
 
-use rustc_hir::LangItem::{OptionNone, OptionSome};
+use rustc_hir::LangItem::OptionNone;
 use rustc_hir::{Arm, Expr, ExprKind, HirId, Pat, PatKind};
 use rustc_lint::LateContext;
 use rustc_span::{SyntaxContext, sym};
@@ -62,11 +63,9 @@ fn peels_blocks_incl_unsafe<'a>(expr: &'a Expr<'a>) -> &'a Expr<'a> {
 fn is_some_expr(cx: &LateContext<'_>, target: HirId, ctxt: SyntaxContext, expr: &Expr<'_>) -> bool {
     if let Some(inner_expr) = peels_blocks_incl_unsafe_opt(expr)
         // there can be not statements in the block as they would be removed when switching to `.filter`
-        && let ExprKind::Call(callee, [arg]) = inner_expr.kind
+        && let Some(arg) = as_some_expr(cx, inner_expr)
     {
-        return ctxt == expr.span.ctxt()
-            && callee.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
-            && arg.res_local_id() == Some(target);
+        return ctxt == expr.span.ctxt() && arg.res_local_id() == Some(target);
     }
     false
 }

clippy_lints/src/matches/manual_ok_err.rs

@@ -1,12 +1,12 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::res::{MaybeDef, MaybeQPath};
+use clippy_utils::res::MaybeDef;
 use clippy_utils::source::{indent_of, reindent_multiline};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::{option_arg_ty, peel_and_count_ty_refs};
-use clippy_utils::{get_parent_expr, peel_blocks, span_contains_comment};
+use clippy_utils::{as_some_expr, get_parent_expr, is_none_expr, peel_blocks, span_contains_comment};
 use rustc_ast::{BindingMode, Mutability};
 use rustc_errors::Applicability;
-use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr};
+use rustc_hir::LangItem::ResultErr;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{Arm, Expr, ExprKind, Pat, PatExpr, PatExprKind, PatKind, Path, QPath};
 use rustc_lint::{LateContext, LintContext};
@@ -106,8 +106,7 @@ fn is_ok_or_err<'hir>(cx: &LateContext<'_>, pat: &Pat<'hir>) -> Option<(bool, &'
 
 /// Check if `expr` contains `Some(ident)`, possibly as a block
 fn is_some_ident<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, ident: &Ident, ty: Ty<'tcx>) -> bool {
-    if let ExprKind::Call(body_callee, [body_arg]) = peel_blocks(expr).kind
-        && body_callee.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
+    if let Some(body_arg) = as_some_expr(cx, peel_blocks(expr))
         && cx.typeck_results().expr_ty(body_arg) == ty
         && let ExprKind::Path(QPath::Resolved(
             _,
@@ -124,7 +123,7 @@ fn is_some_ident<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, ident: &Ident, t
 
 /// Check if `expr` is `None`, possibly as a block
 fn is_none(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
-    peel_blocks(expr).res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone)
+    is_none_expr(cx, peel_blocks(expr))
 }
 
 /// Suggest replacing `expr` by `scrutinee.METHOD()`, where `METHOD` is either `ok` or

clippy_lints/src/matches/manual_utils.rs

@@ -1,16 +1,15 @@
 use crate::map_unit_fn::OPTION_MAP_UNIT_FN;
 use crate::matches::MATCH_AS_REF;
-use clippy_utils::res::{MaybeDef, MaybeQPath, MaybeResPath};
+use clippy_utils::res::{MaybeDef, MaybeResPath};
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::{is_copy, is_unsafe_fn, peel_and_count_ty_refs};
 use clippy_utils::{
     CaptureKind, as_some_pattern, can_move_expr_to_closure, expr_requires_coercion, is_else_clause, is_lint_allowed,
-    is_none_pattern, peel_blocks, peel_hir_expr_refs, peel_hir_expr_while,
+    is_none_expr, is_none_pattern, peel_blocks, peel_hir_expr_refs, peel_hir_expr_while,
 };
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_errors::Applicability;
-use rustc_hir::LangItem::OptionNone;
 use rustc_hir::def::Res;
 use rustc_hir::{BindingMode, Expr, ExprKind, HirId, Mutability, Pat, PatKind, Path, QPath};
 use rustc_lint::LateContext;
@@ -44,16 +43,16 @@ where
         try_parse_pattern(cx, then_pat, expr_ctxt),
         else_pat.map_or(Some(OptionPat::Wild), |p| try_parse_pattern(cx, p, expr_ctxt)),
     ) {
-        (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
+        (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count })) if is_none_arm_body(cx, then_body) => {
             (else_body, pattern, ref_count, true)
         },
-        (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
+        (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count })) if is_none_arm_body(cx, then_body) => {
             (else_body, pattern, ref_count, false)
         },
-        (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild)) if is_none_expr(cx, else_body) => {
+        (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild)) if is_none_arm_body(cx, else_body) => {
             (then_body, pattern, ref_count, true)
         },
-        (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None)) if is_none_expr(cx, else_body) => {
+        (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None)) if is_none_arm_body(cx, else_body) => {
             (then_body, pattern, ref_count, false)
         },
         _ => return None,
@@ -268,6 +267,6 @@ pub(super) fn try_parse_pattern<'tcx>(
 }
 
 /// Checks for the `None` value, possibly in a block.
-fn is_none_expr(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
-    peel_blocks(expr).res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone)
+fn is_none_arm_body(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+    is_none_expr(cx, peel_blocks(expr))
 }

clippy_lints/src/matches/match_as_ref.rs

@@ -1,10 +1,9 @@
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::option_arg_ty;
-use clippy_utils::{as_some_pattern, is_none_arm, peel_blocks};
+use clippy_utils::{as_some_expr, as_some_pattern, is_none_arm, peel_blocks};
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, BindingMode, ByRef, Expr, ExprKind, LangItem, Mutability, PatKind, QPath};
+use rustc_hir::{Arm, BindingMode, ByRef, Expr, ExprKind, Mutability, PatKind, QPath};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 
@@ -84,8 +83,7 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr:
 fn as_ref_some_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> Option<Mutability> {
     if let Some([first_pat, ..]) = as_some_pattern(cx, arm.pat)
         && let PatKind::Binding(BindingMode(ByRef::Yes(mutabl), _), .., ident, _) = first_pat.kind
-        && let ExprKind::Call(e, [arg]) = peel_blocks(arm.body).kind
-        && e.res(cx).ctor_parent(cx).is_lang_item(cx, LangItem::OptionSome)
+        && let Some(arg) = as_some_expr(cx, peel_blocks(arm.body))
         && let ExprKind::Path(QPath::Resolved(_, path2)) = arg.kind
         && path2.segments.len() == 1
         && ident.name == path2.segments[0].ident.name

clippy_lints/src/mem_replace.rs

@@ -1,13 +1,14 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::msrvs::{self, Msrv};
-use clippy_utils::res::{MaybeDef, MaybeQPath};
+use clippy_utils::res::MaybeDef;
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::is_non_aggregate_primitive_type;
-use clippy_utils::{is_default_equivalent, is_expr_used_or_unified, peel_ref_operators, std_or_core};
+use clippy_utils::{
+    as_some_expr, is_default_equivalent, is_expr_used_or_unified, is_none_expr, peel_ref_operators, std_or_core,
+};
 use rustc_errors::Applicability;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::impl_lint_pass;
@@ -128,7 +129,7 @@ impl_lint_pass!(MemReplace =>
     [MEM_REPLACE_OPTION_WITH_NONE, MEM_REPLACE_OPTION_WITH_SOME, MEM_REPLACE_WITH_UNINIT, MEM_REPLACE_WITH_DEFAULT]);
 
 fn check_replace_option_with_none(cx: &LateContext<'_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) -> bool {
-    if src.res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone) {
+    if is_none_expr(cx, src) {
         // Since this is a late pass (already type-checked),
         // and we already know that the second argument is an
         // `Option`, we do not need to check the first
@@ -161,8 +162,7 @@ fn check_replace_option_with_some(
     expr_span: Span,
     msrv: Msrv,
 ) -> bool {
-    if let ExprKind::Call(src_func, [src_arg]) = src.kind
-        && src_func.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
+    if let Some(src_arg) = as_some_expr(cx, src)
         && msrv.meets(cx, msrvs::OPTION_REPLACE)
     {
         // We do not have to check for a `const` context here, because `core::mem::replace()` and

clippy_lints/src/methods/iter_on_single_or_empty_collections.rs

@@ -1,13 +1,11 @@
 use std::iter::once;
 
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::source::snippet;
 use clippy_utils::ty::{ExprFnSig, expr_sig, ty_sig};
-use clippy_utils::{get_expr_use_or_unification_node, std_or_core, sym};
+use clippy_utils::{as_some_expr, get_expr_use_or_unification_node, is_none_expr, std_or_core, sym};
 
 use rustc_errors::Applicability;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::hir_id::HirId;
 use rustc_hir::{Expr, ExprKind, Node};
 use rustc_lint::LateContext;
@@ -68,15 +66,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, method
     let item = match recv.kind {
         ExprKind::Array([]) => None,
         ExprKind::Array([e]) => Some(e),
-        ExprKind::Path(ref p)
-            if cx
-                .qpath_res(p, recv.hir_id)
-                .ctor_parent(cx)
-                .is_lang_item(cx, OptionNone) =>
-        {
-            None
-        },
-        ExprKind::Call(f, [arg]) if f.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome) => Some(arg),
+        _ if is_none_expr(cx, recv) => None,
+        _ if let Some(arg) = as_some_expr(cx, recv) => Some(arg),
         _ => return,
     };
     let iter_type = match method_name {

clippy_lints/src/methods/option_map_or_none.rs

@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_none_expr;
 use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::source::snippet;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
+use rustc_hir::LangItem::OptionSome;
 use rustc_lint::LateContext;
 use rustc_span::symbol::sym;
 
@@ -48,7 +49,7 @@ pub(super) fn check<'tcx>(
         return;
     }
 
-    if !def_arg.res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone) {
+    if !is_none_expr(cx, def_arg) {
         // nothing to lint!
         return;
     }

clippy_lints/src/methods/result_map_or_else_none.rs

@@ -1,10 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::peel_blocks;
 use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::source::snippet;
+use clippy_utils::{is_none_expr, peel_blocks};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
+use rustc_hir::LangItem::OptionSome;
 use rustc_lint::LateContext;
 use rustc_span::symbol::sym;
 
@@ -25,7 +25,7 @@ pub(super) fn check<'tcx>(
         && let hir::ExprKind::Closure(&hir::Closure { body, .. }) = def_arg.kind
         && let body = cx.tcx.hir_body(body)
         // And finally we check that we return a `None` in the "else case".
-        && peel_blocks(body.value).res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone)
+        && is_none_expr(cx, peel_blocks(body.value))
     {
         let msg = "called `map_or_else(|_| None, Some)` on a `Result` value";
         let self_snippet = snippet(cx, recv.span, "..");

clippy_lints/src/methods/unnecessary_filter_map.rs

@@ -1,10 +1,10 @@
 use super::utils::clone_or_copy_needed;
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::res::{MaybeDef, MaybeQPath, MaybeResPath, MaybeTypeckRes};
-use clippy_utils::sym;
 use clippy_utils::ty::{is_copy, option_arg_ty};
 use clippy_utils::usage::mutated_variables;
 use clippy_utils::visitors::{Descend, for_each_expr_without_closures};
+use clippy_utils::{as_some_expr, sym};
 use core::ops::ControlFlow;
 use rustc_hir as hir;
 use rustc_hir::LangItem::{OptionNone, OptionSome};
@@ -47,8 +47,7 @@ pub(super) fn check<'tcx>(
         let sugg = if !found_filtering {
             // Check if the closure is .filter_map(|x| Some(x))
             if kind.is_filter_map()
-                && let hir::ExprKind::Call(expr, [arg]) = body.value.kind
-                && expr.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
+                && let Some(arg) = as_some_expr(cx, body.value)
                 && let hir::ExprKind::Path(_) = arg.kind
             {
                 span_lint(

clippy_lints/src/methods/unnecessary_literal_unwrap.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::res::{MaybeDef, MaybeQPath};
-use clippy_utils::{last_path_segment, sym};
+use clippy_utils::{is_none_expr, last_path_segment, sym};
 use rustc_errors::Applicability;
 use rustc_hir::{self as hir, AmbigArg};
 use rustc_lint::LateContext;
@@ -56,7 +56,7 @@ pub(super) fn check(
         } else {
             return;
         }
-    } else if init.res(cx).ctor_parent(cx).is_lang_item(cx, hir::LangItem::OptionNone) {
+    } else if is_none_expr(cx, init) {
         let call_args: &[hir::Expr<'_>] = &[];
         (sym::None, call_args, None)
     } else {

clippy_utils/src/lib.rs

@@ -131,7 +131,7 @@ use crate::ast_utils::unordered_over;
 use crate::consts::{ConstEvalCtxt, Constant};
 use crate::higher::Range;
 use crate::msrvs::Msrv;
-use crate::res::{MaybeDef, MaybeResPath};
+use crate::res::{MaybeDef, MaybeQPath, MaybeResPath};
 use crate::ty::{adt_and_variant_of_res, can_partially_move_ty, expr_sig, is_copy, is_recursively_primitive_type};
 use crate::visitors::for_each_expr_without_closures;
 
@@ -300,6 +300,22 @@ pub fn is_lang_item_or_ctor(cx: &LateContext<'_>, did: DefId, item: LangItem) ->
     cx.tcx.lang_items().get(item) == Some(did)
 }
 
+/// Checks is `expr` is `None`
+pub fn is_none_expr(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+    expr.res(cx).ctor_parent(cx).is_lang_item(cx, OptionNone)
+}
+
+/// If `expr` is `Some(inner)`, returns `inner`
+pub fn as_some_expr<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+    if let ExprKind::Call(e, [arg]) = expr.kind
+        && e.res(cx).ctor_parent(cx).is_lang_item(cx, OptionSome)
+    {
+        Some(arg)
+    } else {
+        None
+    }
+}
+
 /// Checks if `expr` is an empty block or an empty tuple.
 pub fn is_unit_expr(expr: &Expr<'_>) -> bool {
     matches!(