1 use crate::{EarlyContext, EarlyLintPass, LintContext};
2 use rustc_ast::{Block, StmtKind};
3 use rustc_errors::Applicability;
7 /// The `redundant_semicolons` lint detects unnecessary trailing
20 /// Extra semicolons are not needed, and may be removed to avoid confusion
21 /// and visual clutter.
22 pub REDUNDANT_SEMICOLONS,
24 "detects unnecessary trailing semicolons"
27 declare_lint_pass!(RedundantSemicolons => [REDUNDANT_SEMICOLONS]);
29 impl EarlyLintPass for RedundantSemicolons {
30 fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) {
32 for stmt in block.stmts.iter() {
33 match (&stmt.kind, &mut seq) {
34 (StmtKind::Empty, None) => seq = Some((stmt.span, false)),
35 (StmtKind::Empty, Some(seq)) => *seq = (seq.0.to(stmt.span), true),
36 (_, seq) => maybe_lint_redundant_semis(cx, seq),
39 maybe_lint_redundant_semis(cx, &mut seq);
43 fn maybe_lint_redundant_semis(cx: &EarlyContext<'_>, seq: &mut Option<(Span, bool)>) {
44 if let Some((span, multiple)) = seq.take() {
45 // FIXME: Find a better way of ignoring the trailing
46 // semicolon from macro expansion
47 if span == rustc_span::DUMMY_SP {
50 cx.struct_span_lint(REDUNDANT_SEMICOLONS, span, |lint| {
51 let (msg, rem) = if multiple {
52 ("unnecessary trailing semicolons", "remove these semicolons")
54 ("unnecessary trailing semicolon", "remove this semicolon")
57 .span_suggestion(span, rem, String::new(), Applicability::MaybeIncorrect)