use crate as utils;
use rustc_hir as hir;
-use rustc_hir::def::Res;
use rustc_hir::intravisit;
use rustc_hir::intravisit::{NestedVisitorMap, Visitor};
use rustc_hir::HirIdSet;
-use rustc_hir::{Expr, ExprKind, HirId, Path};
+use rustc_hir::{Expr, ExprKind, HirId};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::hir::map::Map;
use rustc_middle::mir::FakeReadCause;
use rustc_middle::ty;
-use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
+use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
/// Returns a set of mutated local variable IDs, or `None` if mutations could not be determined.
pub fn mutated_variables<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) -> Option<HirIdSet> {
Some(delegate.used_mutably)
}
-pub fn is_potentially_mutated<'tcx>(variable: &'tcx Path<'_>, expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) -> bool {
- if let Res::Local(id) = variable.res {
- mutated_variables(expr, cx).map_or(true, |mutated| mutated.contains(&id))
- } else {
- true
- }
+pub fn is_potentially_mutated<'tcx>(variable: HirId, expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) -> bool {
+ mutated_variables(expr, cx).map_or(true, |mutated| mutated.contains(&variable))
}
struct MutVarsDelegate {
}
impl<'tcx> Delegate<'tcx> for MutVarsDelegate {
- fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId, _: ConsumeMode) {}
+ fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {}
fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId, bk: ty::BorrowKind) {
if let ty::BorrowKind::MutBorrow = bk {
recursive_visitor.visit_expr(expression);
recursive_visitor.seen_return_break_continue
}
+
+pub struct UsedAfterExprVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+ definition: HirId,
+ past_expr: bool,
+ used_after_expr: bool,
+}
+impl<'a, 'tcx> UsedAfterExprVisitor<'a, 'tcx> {
+ pub fn is_found(cx: &'a LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
+ utils::path_to_local(expr).map_or(false, |definition| {
+ let mut visitor = UsedAfterExprVisitor {
+ cx,
+ expr,
+ definition,
+ past_expr: false,
+ used_after_expr: false,
+ };
+ utils::get_enclosing_block(cx, definition).map_or(false, |block| {
+ visitor.visit_block(block);
+ visitor.used_after_expr
+ })
+ })
+ }
+}
+
+impl<'a, 'tcx> intravisit::Visitor<'tcx> for UsedAfterExprVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+ NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if self.used_after_expr {
+ return;
+ }
+
+ if expr.hir_id == self.expr.hir_id {
+ self.past_expr = true;
+ } else if self.past_expr && utils::path_to_local_id(expr, self.definition) {
+ self.used_after_expr = true;
+ } else {
+ intravisit::walk_expr(self, expr);
+ }
+ }
+}