add lint for mutable borrow; may have false positives. pushed for feedback

This commit is contained in:
Laura Peskin 2017-09-25 02:00:21 -04:00
parent 2fe968774a
commit d7867ef8c1
2 changed files with 27 additions and 5 deletions

View file

@ -1327,7 +1327,20 @@ impl<'tcx> Delegate<'tcx> for MutateDelegate {
fn consume_pat(&mut self, _: &Pat, _: cmt<'tcx>, _: ConsumeMode) { fn consume_pat(&mut self, _: &Pat, _: cmt<'tcx>, _: ConsumeMode) {
} }
fn borrow(&mut self, _: NodeId, _: Span, _: cmt<'tcx>, _: ty::Region, _: ty::BorrowKind, _: LoanCause) { fn borrow(&mut self, _: NodeId, sp: Span, cmt: cmt<'tcx>, _: ty::Region, bk: ty::BorrowKind, _: LoanCause) {
match bk {
ty::BorrowKind::MutBorrow => {
if let Categorization::Local(id) = cmt.cat {
if Some(id) == self.node_id_low {
self.span_low = Some(sp)
}
if Some(id) == self.node_id_high {
self.span_high = Some(sp)
}
}
},
_ => (),
}
} }
fn mutate(&mut self, _: NodeId, sp: Span, cmt: cmt<'tcx>, _: MutateMode) { fn mutate(&mut self, _: NodeId, sp: Span, cmt: cmt<'tcx>, _: MutateMode) {
@ -1390,8 +1403,8 @@ fn check_for_mutability(cx: &LateContext, bound: &Expr) -> Option<NodeId> {
fn check_for_mutation(cx: &LateContext, body: &Expr, bound_ids: Vec<Option<NodeId>>) -> (Option<Span>, Option<Span>) { fn check_for_mutation(cx: &LateContext, body: &Expr, bound_ids: Vec<Option<NodeId>>) -> (Option<Span>, Option<Span>) {
let mut delegate = MutateDelegate { node_id_low: bound_ids[0], node_id_high: bound_ids[1], span_low: None, span_high: None }; let mut delegate = MutateDelegate { node_id_low: bound_ids[0], node_id_high: bound_ids[1], span_low: None, span_high: None };
let d = def_id::DefId::local(body.hir_id.owner); let def_id = def_id::DefId::local(body.hir_id.owner);
let region_scope_tree = &cx.tcx.region_scope_tree(d); let region_scope_tree = &cx.tcx.region_scope_tree(def_id);
ExprUseVisitor::new(&mut delegate, cx.tcx, cx.param_env, region_scope_tree, cx.tables).walk_expr(body); ExprUseVisitor::new(&mut delegate, cx.tcx, cx.param_env, region_scope_tree, cx.tables).walk_expr(body);
return delegate.mutation_span(); return delegate.mutation_span();
} }

View file

@ -9,6 +9,8 @@ fn main() {
mut_range_bound_both(); mut_range_bound_both();
mut_range_bound_no_mutation(); mut_range_bound_no_mutation();
immut_range_bound(); immut_range_bound();
mut_borrow_range_bound();
immut_borrow_range_bound();
} }
fn mut_range_bound_upper() { fn mut_range_bound_upper() {
@ -35,8 +37,15 @@ fn mut_range_bound_no_mutation() {
fn mut_borrow_range_bound() { fn mut_borrow_range_bound() {
let mut m = 4; let mut m = 4;
for i in 0..m { for i in 0..m {
let n = &mut m; let n = &mut m; // warning here?
*n += 1; *n += 1; // or here?
}
}
fn immut_borrow_range_bound() {
let mut m = 4;
for i in 0..m {
let n = &m; // should be no warning?
} }
} }