diff options
4 files changed, 139 insertions, 0 deletions
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index 806bca78f78..50a27d7e84f 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -942,6 +942,22 @@ trait UnusedDelimLint { match s.kind { StmtKind::Let(ref local) if Self::LINT_EXPR_IN_PATTERN_MATCHING_CTX => { if let Some((init, els)) = local.kind.init_else_opt() { + if els.is_some() + && let ExprKind::Paren(paren) = &init.kind + && !init.span.eq_ctxt(paren.span) + { + // This branch prevents cases where parentheses wrap an expression + // resulting from macro expansion, such as: + // ``` + // macro_rules! x { + // () => { None::<i32> }; + // } + // let Some(_) = (x!{}) else { return }; + // // -> let Some(_) = (None::<i32>) else { return }; + // // ~ ~ No Lint + // ``` + return; + } let ctx = match els { None => UnusedDelimsCtx::AssignedValue, Some(_) => UnusedDelimsCtx::AssignedValueLetElse, diff --git a/tests/ui/lint/unused-parens-for-macro-call-with-brace.fixed b/tests/ui/lint/unused-parens-for-macro-call-with-brace.fixed new file mode 100644 index 00000000000..4c9995fcb61 --- /dev/null +++ b/tests/ui/lint/unused-parens-for-macro-call-with-brace.fixed @@ -0,0 +1,28 @@ +//@ run-rustfix + +#![deny(unused_parens)] + +fn main() { + macro_rules! x { + () => { None::<i32> }; + } + + let Some(_) = (x!{}) else { return }; // no error + let Some(_) = (x!{}) else { return }; + //~^ ERROR: unnecessary parentheses around assigned value + + let Some(_) = (x!{}) else { return }; + //~^ ERROR: unnecessary parentheses around pattern + + let _ = x!{}; + let _ = x!{}; + //~^ ERROR: unnecessary parentheses around assigned value + + if let Some(_) = x!{} {}; + if let Some(_) = x!{} {}; + //~^ ERROR: unnecessary parentheses around `let` scrutinee expression + + while let Some(_) = x!{} {}; + while let Some(_) = x!{} {}; + //~^ ERROR: unnecessary parentheses around `let` scrutinee expression +} diff --git a/tests/ui/lint/unused-parens-for-macro-call-with-brace.rs b/tests/ui/lint/unused-parens-for-macro-call-with-brace.rs new file mode 100644 index 00000000000..59e215a48cc --- /dev/null +++ b/tests/ui/lint/unused-parens-for-macro-call-with-brace.rs @@ -0,0 +1,28 @@ +//@ run-rustfix + +#![deny(unused_parens)] + +fn main() { + macro_rules! x { + () => { None::<i32> }; + } + + let Some(_) = (x!{}) else { return }; // no error + let Some(_) = ((x!{})) else { return }; + //~^ ERROR: unnecessary parentheses around assigned value + + let Some((_)) = (x!{}) else { return }; + //~^ ERROR: unnecessary parentheses around pattern + + let _ = x!{}; + let _ = (x!{}); + //~^ ERROR: unnecessary parentheses around assigned value + + if let Some(_) = x!{} {}; + if let Some(_) = (x!{}) {}; + //~^ ERROR: unnecessary parentheses around `let` scrutinee expression + + while let Some(_) = x!{} {}; + while let Some(_) = (x!{}) {}; + //~^ ERROR: unnecessary parentheses around `let` scrutinee expression +} diff --git a/tests/ui/lint/unused-parens-for-macro-call-with-brace.stderr b/tests/ui/lint/unused-parens-for-macro-call-with-brace.stderr new file mode 100644 index 00000000000..8d3b4fe493e --- /dev/null +++ b/tests/ui/lint/unused-parens-for-macro-call-with-brace.stderr @@ -0,0 +1,67 @@ +error: unnecessary parentheses around assigned value + --> $DIR/unused-parens-for-macro-call-with-brace.rs:11:19 + | +LL | let Some(_) = ((x!{})) else { return }; + | ^ ^ + | +note: the lint level is defined here + --> $DIR/unused-parens-for-macro-call-with-brace.rs:3:9 + | +LL | #![deny(unused_parens)] + | ^^^^^^^^^^^^^ +help: remove these parentheses + | +LL - let Some(_) = ((x!{})) else { return }; +LL + let Some(_) = (x!{}) else { return }; + | + +error: unnecessary parentheses around pattern + --> $DIR/unused-parens-for-macro-call-with-brace.rs:14:14 + | +LL | let Some((_)) = (x!{}) else { return }; + | ^ ^ + | +help: remove these parentheses + | +LL - let Some((_)) = (x!{}) else { return }; +LL + let Some(_) = (x!{}) else { return }; + | + +error: unnecessary parentheses around assigned value + --> $DIR/unused-parens-for-macro-call-with-brace.rs:18:13 + | +LL | let _ = (x!{}); + | ^ ^ + | +help: remove these parentheses + | +LL - let _ = (x!{}); +LL + let _ = x!{}; + | + +error: unnecessary parentheses around `let` scrutinee expression + --> $DIR/unused-parens-for-macro-call-with-brace.rs:22:22 + | +LL | if let Some(_) = (x!{}) {}; + | ^ ^ + | +help: remove these parentheses + | +LL - if let Some(_) = (x!{}) {}; +LL + if let Some(_) = x!{} {}; + | + +error: unnecessary parentheses around `let` scrutinee expression + --> $DIR/unused-parens-for-macro-call-with-brace.rs:26:25 + | +LL | while let Some(_) = (x!{}) {}; + | ^ ^ + | +help: remove these parentheses + | +LL - while let Some(_) = (x!{}) {}; +LL + while let Some(_) = x!{} {}; + | + +error: aborting due to 5 previous errors + |