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Macro check len_zero

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This commit is contained in:
mcarton 2016-02-24 20:53:15 +01:00
parent c1b2fe31b7
commit 7b1a0a9434
1 changed files with 9 additions and 1 deletions
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10
src/len_zero.rs
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@ -8,7 +8,7 @@ use rustc::middle::ty::{self, MethodTraitItemId, ImplOrTraitItemId};
use syntax::ast::{Lit, LitKind};
use utils::{get_item_name, snippet, span_lint, span_lint_and_then, walk_ptrs_ty};
use utils::{get_item_name, in_macro, snippet, span_lint, span_lint_and_then, walk_ptrs_ty};
/// **What it does:** This lint checks for getting the length of something via `.len()` just to compare to zero, and suggests using `.is_empty()` where applicable.
///
@ -51,6 +51,10 @@ impl LintPass for LenZero {
impl LateLintPass for LenZero {
fn check_item(&mut self, cx: &LateContext, item: &Item) {
if in_macro(cx, item.span) {
return;
}
match item.node {
ItemTrait(_, _, _, ref trait_items) => check_trait_items(cx, item, trait_items),
ItemImpl(_, _, _, None, _, ref impl_items) => check_impl_items(cx, item, impl_items),
@ -59,6 +63,10 @@ impl LateLintPass for LenZero {
}
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
if in_macro(cx, expr.span) {
return;
}
if let ExprBinary(Spanned{node: cmp, ..}, ref left, ref right) = expr.node {
match cmp {
BiEq => check_cmp(cx, expr.span, left, right, ""),