mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-11-23 13:13:34 +00:00
Fix boxed_local
suggestion
Don't warn about an argument that is moved into a closure. ExprUseVisitor doesn't walk into nested bodies so use a new visitor that collects the variables that are moved into closures. Fixes #3739
This commit is contained in:
parent
027dde92e2
commit
9d6ecc7485
3 changed files with 66 additions and 4 deletions
|
@ -1,11 +1,12 @@
|
|||
use crate::utils::span_lint;
|
||||
use rustc::hir::intravisit as visit;
|
||||
use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
|
||||
use rustc::hir::*;
|
||||
use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
|
||||
use rustc::middle::expr_use_visitor::*;
|
||||
use rustc::middle::mem_categorization::{cmt_, Categorization};
|
||||
use rustc::ty::layout::LayoutOf;
|
||||
use rustc::ty::{self, Ty};
|
||||
use rustc::ty::{self, Ty, UpvarCapture};
|
||||
use rustc::util::nodemap::NodeSet;
|
||||
use rustc::{declare_tool_lint, lint_array};
|
||||
use syntax::ast::NodeId;
|
||||
|
@ -88,11 +89,17 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
|
|||
let region_scope_tree = &cx.tcx.region_scope_tree(fn_def_id);
|
||||
ExprUseVisitor::new(&mut v, cx.tcx, cx.param_env, region_scope_tree, cx.tables, None).consume_body(body);
|
||||
|
||||
for node in v.set {
|
||||
let mut capture_visitor = CaptureVisitor {
|
||||
cx,
|
||||
moved: NodeSet::default(),
|
||||
};
|
||||
capture_visitor.visit_body(body);
|
||||
|
||||
for node in v.set.difference(&capture_visitor.moved) {
|
||||
span_lint(
|
||||
cx,
|
||||
BOXED_LOCAL,
|
||||
cx.tcx.hir().span(node),
|
||||
cx.tcx.hir().span(*node),
|
||||
"local variable doesn't need to be boxed here",
|
||||
);
|
||||
}
|
||||
|
@ -192,3 +199,32 @@ impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {
|
|||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct CaptureVisitor<'a, 'tcx: 'a> {
|
||||
cx: &'a LateContext<'a, 'tcx>,
|
||||
moved: NodeSet,
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> Visitor<'tcx> for CaptureVisitor<'a, 'tcx> {
|
||||
fn visit_expr(&mut self, expr: &'tcx Expr) {
|
||||
if let ExprKind::Closure(..) = expr.node {
|
||||
if let ty::Closure(def_id, _) = &self.cx.tables.expr_ty(expr).sty {
|
||||
if let Some(upvar_list) = &self.cx.tables.upvar_list.get(&def_id) {
|
||||
for upvar_id in upvar_list.iter() {
|
||||
if let UpvarCapture::ByValue = self.cx.tables.upvar_capture(*upvar_id) {
|
||||
let hir_id = upvar_id.var_path.hir_id;
|
||||
let id = &self.cx.tcx.hir().hir_to_node_id(hir_id);
|
||||
self.moved.insert(*id);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
} else {
|
||||
walk_expr(self, expr);
|
||||
}
|
||||
}
|
||||
|
||||
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
|
||||
NestedVisitorMap::None
|
||||
}
|
||||
}
|
||||
|
|
|
@ -148,3 +148,23 @@ trait MyTrait {
|
|||
impl<T> MyTrait for Box<T> {
|
||||
fn do_sth(self) {}
|
||||
}
|
||||
|
||||
// Issue #3739 - capture in closures
|
||||
mod issue_3739 {
|
||||
use super::A;
|
||||
|
||||
fn consume<T>(_: T) {}
|
||||
fn borrow<T>(_: &T) {}
|
||||
|
||||
fn closure_consume(x: Box<A>) {
|
||||
let _ = move || {
|
||||
consume(x);
|
||||
};
|
||||
}
|
||||
|
||||
fn closure_borrow(x: Box<A>) {
|
||||
let _ = || {
|
||||
borrow(&x);
|
||||
};
|
||||
}
|
||||
}
|
||||
|
|
|
@ -12,5 +12,11 @@ error: local variable doesn't need to be boxed here
|
|||
LL | pub fn new(_needs_name: Box<PeekableSeekable<&()>>) -> () {}
|
||||
| ^^^^^^^^^^^
|
||||
|
||||
error: aborting due to 2 previous errors
|
||||
error: local variable doesn't need to be boxed here
|
||||
--> $DIR/escape_analysis.rs:165:23
|
||||
|
|
||||
LL | fn closure_borrow(x: Box<A>) {
|
||||
| ^
|
||||
|
||||
error: aborting due to 3 previous errors
|
||||
|
||||
|
|
Loading…
Reference in a new issue