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and check for Result

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J-ZhengLi 2022-04-16 17:40:28 +08:00 • committed by Philipp Krones
parent 5d403c0b85
commit ffe7125163
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GPG key ID: 1CA0DF2AF59D68A5
3 changed files with 39 additions and 29 deletions
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28
clippy_lints/src/option_if_let_else.rs
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@ -1,19 +1,17 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::sugg::Sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{
can_move_expr_to_closure, eager_or_lazy, higher, in_constant, is_else_clause, is_lang_ctor, peel_blocks,
peel_hir_expr_while, CaptureKind,
};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::LangItem::{OptionNone, OptionSome};
use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr, ResultOk};
use rustc_hir::{
def::Res, Arm, BindingAnnotation, Expr, ExprKind, MatchSource, Mutability, Pat, PatKind, Path, QPath, UnOp,
};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
@ -74,16 +72,6 @@ declare_clippy_lint! {
declare_lint_pass!(OptionIfLetElse => [OPTION_IF_LET_ELSE]);
/// Returns true iff the given expression is the result of calling `Result::ok`
fn is_result_ok(cx: &LateContext<'_>, expr: &'_ Expr<'_>) -> bool {
if let ExprKind::MethodCall(path, &[ref receiver], _) = &expr.kind {
path.ident.name.as_str() == "ok"
&& is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(receiver), sym::Result)
} else {
false
}
}
/// A struct containing information about occurrences of construct that this lint detects
///
/// Such as:
@ -130,9 +118,8 @@ fn try_get_option_occurence<'tcx>(
ExprKind::Unary(UnOp::Deref, inner_expr) | ExprKind::AddrOf(_, _, inner_expr) => inner_expr,
_ => expr,
};
let inner_pat = try_get_inner_pat(cx, pat)?;
if_chain! {
if !is_result_ok(cx, cond_expr); // Don't lint on Result::ok because a different lint does it already
let inner_pat = try_get_inner_pat(cx, pat)?;
if let PatKind::Binding(bind_annotation, _, id, None) = inner_pat.kind;
if let Some(some_captures) = can_move_expr_to_closure(cx, if_then);
if let Some(none_captures) = can_move_expr_to_closure(cx, if_else);
@ -185,7 +172,7 @@ fn try_get_option_occurence<'tcx>(
fn try_get_inner_pat<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>) -> Option<&'tcx Pat<'tcx>> {
if let PatKind::TupleStruct(ref qpath, [inner_pat], ..) = pat.kind {
if is_lang_ctor(cx, qpath, OptionSome) {
if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk) {
return Some(inner_pat);
}
}
@ -224,9 +211,9 @@ fn try_convert_match<'tcx>(
arms: &[Arm<'tcx>],
) -> Option<(&'tcx Pat<'tcx>, &'tcx Expr<'tcx>, &'tcx Expr<'tcx>)> {
if arms.len() == 2 {
return if is_none_arm(cx, &arms[1]) {
return if is_none_or_err_arm(cx, &arms[1]) {
Some((arms[0].pat, arms[0].body, arms[1].body))
} else if is_none_arm(cx, &arms[0]) {
} else if is_none_or_err_arm(cx, &arms[0]) {
Some((arms[1].pat, arms[1].body, arms[0].body))
} else {
None
@ -235,9 +222,12 @@ fn try_convert_match<'tcx>(
None
}
fn is_none_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
fn is_none_or_err_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
match arm.pat.kind {
PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
PatKind::TupleStruct(ref qpath, [first_pat], _) => {
is_lang_ctor(cx, qpath, ResultErr) && matches!(first_pat.kind, PatKind::Wild)
},
PatKind::Wild => true,
_ => false,
}