diff --git a/clippy_lints/src/matches/single_match.rs b/clippy_lints/src/matches/single_match.rs index 4bd46bced38..e7cef5bdbd7 100644 --- a/clippy_lints/src/matches/single_match.rs +++ b/clippy_lints/src/matches/single_match.rs @@ -1,5 +1,5 @@ use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::source::{expr_block, snippet, SpanRangeExt}; +use clippy_utils::source::{expr_block, snippet, snippet_block_with_context, SpanRangeExt}; use clippy_utils::ty::implements_trait; use clippy_utils::{ is_lint_allowed, is_unit_expr, peel_blocks, peel_hir_pat_refs, peel_middle_ty_refs, peel_n_hir_expr_refs, @@ -9,7 +9,7 @@ use rustc_errors::Applicability; use rustc_hir::def::{DefKind, Res}; use rustc_hir::intravisit::{walk_pat, Visitor}; -use rustc_hir::{Arm, Expr, ExprKind, HirId, Pat, PatKind, QPath}; +use rustc_hir::{Arm, Expr, ExprKind, HirId, Node, Pat, PatKind, QPath, StmtKind}; use rustc_lint::LateContext; use rustc_middle::ty::{self, AdtDef, ParamEnv, TyCtxt, TypeckResults, VariantDef}; use rustc_span::{sym, Span}; @@ -93,8 +93,24 @@ fn report_single_pattern(cx: &LateContext<'_>, ex: &Expr<'_>, arm: &Arm<'_>, exp if snippet(cx, ex.span, "..") == snippet(cx, arm.pat.span, "..") { let msg = "this pattern is irrefutable, `match` is useless"; - let sugg = expr_block(cx, arm.body, ctxt, "..", Some(expr.span), &mut app); - span_lint_and_sugg(cx, lint, expr.span, msg, "try", sugg, app); + let (sugg, help) = if is_unit_expr(arm.body) { + (String::new(), "`match` expression can be removed") + } else { + let mut sugg = snippet_block_with_context(cx, arm.body.span, ctxt, "..", Some(expr.span), &mut app) + .0 + .to_string(); + if let Node::Stmt(stmt) = cx.tcx.parent_hir_node(expr.hir_id) + && let StmtKind::Expr(_) = stmt.kind + && match arm.body.kind { + ExprKind::Block(block, _) => block.span.from_expansion(), + _ => true, + } + { + sugg.push(';'); + } + (sugg, "try") + }; + span_lint_and_sugg(cx, lint, expr.span, msg, help, sugg.to_string(), app); return; } diff --git a/tests/ui/single_match.fixed b/tests/ui/single_match.fixed index 04129ec0f13..dcf5a1d33c2 100644 --- a/tests/ui/single_match.fixed +++ b/tests/ui/single_match.fixed @@ -304,13 +304,19 @@ const DATA: Data = Data([1, 2, 3, 4]); const CONST_I32: i32 = 1; fn irrefutable_match() { - { println!() } + println!(); - { println!() } + println!(); let i = 0; { let a = 1; let b = 2; } + + + + + + println!() } diff --git a/tests/ui/single_match.rs b/tests/ui/single_match.rs index 2d51cee3fd9..3ba5eebd01b 100644 --- a/tests/ui/single_match.rs +++ b/tests/ui/single_match.rs @@ -386,4 +386,19 @@ fn irrefutable_match() { }, _ => {}, } + + match i { + i => {}, + _ => {}, + } + + match i { + i => (), + _ => (), + } + + match CONST_I32 { + CONST_I32 => println!(), + _ => {}, + } } diff --git a/tests/ui/single_match.stderr b/tests/ui/single_match.stderr index 9578421d2ce..9240b09c50a 100644 --- a/tests/ui/single_match.stderr +++ b/tests/ui/single_match.stderr @@ -223,7 +223,7 @@ LL | / match DATA { LL | | DATA => println!(), LL | | _ => {}, LL | | } - | |_____^ help: try: `{ println!() }` + | |_____^ help: try: `println!();` error: this pattern is irrefutable, `match` is useless --> tests/ui/single_match.rs:376:5 @@ -232,7 +232,7 @@ LL | / match CONST_I32 { LL | | CONST_I32 => println!(), LL | | _ => {}, LL | | } - | |_____^ help: try: `{ println!() }` + | |_____^ help: try: `println!();` error: this pattern is irrefutable, `match` is useless --> tests/ui/single_match.rs:382:5 @@ -254,5 +254,32 @@ LL + let b = 2; LL + } | -error: aborting due to 23 previous errors +error: this pattern is irrefutable, `match` is useless + --> tests/ui/single_match.rs:390:5 + | +LL | / match i { +LL | | i => {}, +LL | | _ => {}, +LL | | } + | |_____^ help: `match` expression can be removed + +error: this pattern is irrefutable, `match` is useless + --> tests/ui/single_match.rs:395:5 + | +LL | / match i { +LL | | i => (), +LL | | _ => (), +LL | | } + | |_____^ help: `match` expression can be removed + +error: this pattern is irrefutable, `match` is useless + --> tests/ui/single_match.rs:400:5 + | +LL | / match CONST_I32 { +LL | | CONST_I32 => println!(), +LL | | _ => {}, +LL | | } + | |_____^ help: try: `println!()` + +error: aborting due to 26 previous errors diff --git a/tests/ui/single_match_else.fixed b/tests/ui/single_match_else.fixed index fb57411aaa4..c2ca746976b 100644 --- a/tests/ui/single_match_else.fixed +++ b/tests/ui/single_match_else.fixed @@ -173,5 +173,5 @@ fn issue_10808(bar: Option) { } fn irrefutable_match() -> Option<&'static ExprNode> { - { Some(&NODE) } + Some(&NODE) } diff --git a/tests/ui/single_match_else.stderr b/tests/ui/single_match_else.stderr index 61209053fd0..a2801751a43 100644 --- a/tests/ui/single_match_else.stderr +++ b/tests/ui/single_match_else.stderr @@ -207,7 +207,7 @@ LL | | let x = 5; LL | | None LL | | }, LL | | } - | |_____^ help: try: `{ Some(&NODE) }` + | |_____^ help: try: `Some(&NODE)` error: aborting due to 10 previous errors