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Fix FP for same_item_push

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Don't emit a lint when `pushed_item` was declared as mutable variable.
This commit is contained in:
Takayuki Nakata 2020-08-14 22:54:12 +09:00
parent dc1e09bdc1
commit f98ffa271d
2 changed files with 38 additions and 5 deletions
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35
clippy_lints/src/loops.rs
View file

@ -1141,11 +1141,36 @@ fn detect_same_item_push<'tcx>(
if same_item_push_visitor.should_lint {
if let Some((vec, pushed_item)) = same_item_push_visitor.vec_push {
// Make sure that the push does not involve possibly mutating values
if mutated_variables(pushed_item, cx).map_or(false, |mutvars| mutvars.is_empty()) {
if let PatKind::Wild = pat.kind {
let vec_str = snippet_with_macro_callsite(cx, vec.span, "");
let item_str = snippet_with_macro_callsite(cx, pushed_item.span, "");
if let PatKind::Wild = pat.kind {
let vec_str = snippet_with_macro_callsite(cx, vec.span, "");
let item_str = snippet_with_macro_callsite(cx, pushed_item.span, "");
if let ExprKind::Path(ref qpath) = pushed_item.kind {
if let Res::Local(hir_id) = qpath_res(cx, qpath, pushed_item.hir_id) {
let node = cx.tcx.hir().get(hir_id);
if_chain! {
if let Node::Binding(pat) = node;
if let PatKind::Binding(bind_ann, ..) = pat.kind;
then {
match bind_ann {
BindingAnnotation::RefMut | BindingAnnotation::Mutable => {},
_ => {
span_lint_and_help(
cx,
SAME_ITEM_PUSH,
vec.span,
"it looks like the same item is being pushed into this Vec",
None,
&format!(
"try using vec![{};SIZE] or {}.resize(NEW_SIZE, {})",
item_str, vec_str, item_str
),
)
}
}
}
}
}
} else if mutated_variables(pushed_item, cx).map_or(false, |mutvars| mutvars.is_empty()) {
span_lint_and_help(
cx,
SAME_ITEM_PUSH,

8
tests/ui/same_item_push.rs
View file

@ -86,4 +86,12 @@ fn main() {
for a in vec_a {
vec12.push(2u8.pow(a.kind));
}
// Fix #5902
let mut vec13: Vec<u8> = Vec::new();
let mut item = 0;
for _ in 0..10 {
vec13.push(item);
item += 10;
}
}