diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index 46706e49844..1299444cd77 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -565,10 +565,26 @@ trait UnusedDelimLint { lint.set_arg("delim", Self::DELIM_STR); lint.set_arg("item", msg); if let Some((lo, hi)) = spans { - let replacement = vec![ - (lo, if keep_space.0 { " ".into() } else { "".into() }), - (hi, if keep_space.1 { " ".into() } else { "".into() }), - ]; + let sm = cx.sess().source_map(); + let lo_replace = + if keep_space.0 && + let Ok(snip) = sm.span_to_snippet(lo.with_lo(lo.lo() - BytePos(1))) && + !snip.starts_with(" ") { + " ".to_string() + } else { + "".to_string() + }; + + let hi_replace = + if keep_space.1 && + let Ok(snip) = sm.span_to_snippet(sm.next_point(hi)) && + !snip.starts_with(" ") { + " ".to_string() + } else { + "".to_string() + }; + + let replacement = vec![(lo, lo_replace), (hi, hi_replace)]; lint.multipart_suggestion( fluent::suggestion, replacement, @@ -765,6 +781,7 @@ impl UnusedParens { value: &ast::Pat, avoid_or: bool, avoid_mut: bool, + keep_space: (bool, bool), ) { use ast::{BindingAnnotation, PatKind}; @@ -789,7 +806,7 @@ impl UnusedParens { } else { None }; - self.emit_unused_delims(cx, value.span, spans, "pattern", (false, false)); + self.emit_unused_delims(cx, value.span, spans, "pattern", keep_space); } } } @@ -798,7 +815,7 @@ impl EarlyLintPass for UnusedParens { fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { match e.kind { ExprKind::Let(ref pat, _, _) | ExprKind::ForLoop(ref pat, ..) => { - self.check_unused_parens_pat(cx, pat, false, false); + self.check_unused_parens_pat(cx, pat, false, false, (true, true)); } // We ignore parens in cases like `if (((let Some(0) = Some(1))))` because we already // handle a hard error for them during AST lowering in `lower_expr_mut`, but we still @@ -842,6 +859,7 @@ impl EarlyLintPass for UnusedParens { fn check_pat(&mut self, cx: &EarlyContext<'_>, p: &ast::Pat) { use ast::{Mutability, PatKind::*}; + let keep_space = (false, false); match &p.kind { // Do not lint on `(..)` as that will result in the other arms being useless. Paren(_) @@ -849,33 +867,33 @@ impl EarlyLintPass for UnusedParens { | Wild | Rest | Lit(..) | MacCall(..) | Range(..) | Ident(.., None) | Path(..) => {}, // These are list-like patterns; parens can always be removed. TupleStruct(_, _, ps) | Tuple(ps) | Slice(ps) | Or(ps) => for p in ps { - self.check_unused_parens_pat(cx, p, false, false); + self.check_unused_parens_pat(cx, p, false, false, keep_space); }, Struct(_, _, fps, _) => for f in fps { - self.check_unused_parens_pat(cx, &f.pat, false, false); + self.check_unused_parens_pat(cx, &f.pat, false, false, keep_space); }, // Avoid linting on `i @ (p0 | .. | pn)` and `box (p0 | .. | pn)`, #64106. - Ident(.., Some(p)) | Box(p) => self.check_unused_parens_pat(cx, p, true, false), + Ident(.., Some(p)) | Box(p) => self.check_unused_parens_pat(cx, p, true, false, keep_space), // Avoid linting on `&(mut x)` as `&mut x` has a different meaning, #55342. // Also avoid linting on `& mut? (p0 | .. | pn)`, #64106. - Ref(p, m) => self.check_unused_parens_pat(cx, p, true, *m == Mutability::Not), + Ref(p, m) => self.check_unused_parens_pat(cx, p, true, *m == Mutability::Not, keep_space), } } fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &ast::Stmt) { if let StmtKind::Local(ref local) = s.kind { - self.check_unused_parens_pat(cx, &local.pat, true, false); + self.check_unused_parens_pat(cx, &local.pat, true, false, (false, false)); } ::check_stmt(self, cx, s) } fn check_param(&mut self, cx: &EarlyContext<'_>, param: &ast::Param) { - self.check_unused_parens_pat(cx, ¶m.pat, true, false); + self.check_unused_parens_pat(cx, ¶m.pat, true, false, (false, false)); } fn check_arm(&mut self, cx: &EarlyContext<'_>, arm: &ast::Arm) { - self.check_unused_parens_pat(cx, &arm.pat, false, false); + self.check_unused_parens_pat(cx, &arm.pat, false, false, (false, false)); } fn check_ty(&mut self, cx: &EarlyContext<'_>, ty: &ast::Ty) { diff --git a/src/test/ui/lint/issue-103435-extra-parentheses.fixed b/src/test/ui/lint/issue-103435-extra-parentheses.fixed new file mode 100644 index 00000000000..dbbcaa441dd --- /dev/null +++ b/src/test/ui/lint/issue-103435-extra-parentheses.fixed @@ -0,0 +1,16 @@ +// run-rustfix +#![deny(unused_parens)] + +fn main() { + if let Some(_) = Some(1) {} + //~^ ERROR unnecessary parentheses around pattern + + for _x in 1..10 {} + //~^ ERROR unnecessary parentheses around pattern + + if 2 == 1 {} + //~^ ERROR unnecessary parentheses around `if` condition + + // FIXME, auto recover from this one? + // for(_x in 1..10) {} +} diff --git a/src/test/ui/lint/issue-103435-extra-parentheses.rs b/src/test/ui/lint/issue-103435-extra-parentheses.rs new file mode 100644 index 00000000000..f5c2a6664ed --- /dev/null +++ b/src/test/ui/lint/issue-103435-extra-parentheses.rs @@ -0,0 +1,16 @@ +// run-rustfix +#![deny(unused_parens)] + +fn main() { + if let(Some(_))= Some(1) {} + //~^ ERROR unnecessary parentheses around pattern + + for(_x)in 1..10 {} + //~^ ERROR unnecessary parentheses around pattern + + if(2 == 1){} + //~^ ERROR unnecessary parentheses around `if` condition + + // FIXME, auto recover from this one? + // for(_x in 1..10) {} +} diff --git a/src/test/ui/lint/issue-103435-extra-parentheses.stderr b/src/test/ui/lint/issue-103435-extra-parentheses.stderr new file mode 100644 index 00000000000..a3f2fbc51ab --- /dev/null +++ b/src/test/ui/lint/issue-103435-extra-parentheses.stderr @@ -0,0 +1,43 @@ +error: unnecessary parentheses around pattern + --> $DIR/issue-103435-extra-parentheses.rs:5:11 + | +LL | if let(Some(_))= Some(1) {} + | ^ ^ + | +note: the lint level is defined here + --> $DIR/issue-103435-extra-parentheses.rs:2:9 + | +LL | #![deny(unused_parens)] + | ^^^^^^^^^^^^^ +help: remove these parentheses + | +LL - if let(Some(_))= Some(1) {} +LL + if let Some(_) = Some(1) {} + | + +error: unnecessary parentheses around pattern + --> $DIR/issue-103435-extra-parentheses.rs:8:8 + | +LL | for(_x)in 1..10 {} + | ^ ^ + | +help: remove these parentheses + | +LL - for(_x)in 1..10 {} +LL + for _x in 1..10 {} + | + +error: unnecessary parentheses around `if` condition + --> $DIR/issue-103435-extra-parentheses.rs:11:7 + | +LL | if(2 == 1){} + | ^ ^ + | +help: remove these parentheses + | +LL - if(2 == 1){} +LL + if 2 == 1 {} + | + +error: aborting due to 3 previous errors +