From aeb5a0e60cc7b61253fa486b4e3af4d537af7322 Mon Sep 17 00:00:00 2001
From: Devon Hollowood <devonhollowood@gmail.com>
Date: Sat, 12 Dec 2015 17:51:58 -0800
Subject: [PATCH] Reduce false positives
Add macro checking, and only lint for single leading underscores
---
src/misc.rs | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/src/misc.rs b/src/misc.rs
index 5c3aeeb7899..f46a26c10e1 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -334,19 +334,24 @@ impl LateLintPass for UsedUnderscoreBinding {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
let needs_lint = match expr.node {
ExprPath(_, ref path) => {
- path.segments.last().unwrap().identifier.name.as_str().chars().next() == Some('_') &&
- (cx.tcx.def_map.borrow()).values().any(|res| match res.base_def {
+ let ident = path.segments.last()
+ .expect("path should always have at least one segment")
+ .identifier;
+ ident.name.as_str().chars().next() == Some('_') //starts with '_'
+ && ident.name.as_str().chars().skip(1).next() != Some('_') //doesn't start with "__"
+ && ident.name != ident.unhygienic_name //not in macro
+ && cx.tcx.def_map.borrow().values().any(|res| match res.base_def {
Def::DefLocal(_, _) => true,
_ => false
- })
+ }) //local variable
},
ExprField(_, spanned) => spanned.node.as_str().chars().next() == Some('_'),
_ => false
};
if needs_lint {
- cx.span_lint(USED_UNDERSCORE_BINDING, expr.span, &format!(
- "used binding which is prefixed with an underscore. A leading underscore signals\
- that a binding will not be used."));
+ cx.span_lint(USED_UNDERSCORE_BINDING, expr.span,
+ "used binding which is prefixed with an underscore. A leading underscore\
+ signals that a binding will not be used.");
}
}
}