-use rustc::lint::*;
-use rustc::hir::{Expr, ExprCall, ExprPath};
-use utils::{match_def_path, opt_def_id, paths, span_lint};
+use crate::utils::{match_def_path, paths, qpath_res, span_lint};
+use rustc::hir::{Expr, ExprKind};
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_lint_pass, declare_tool_lint};
-/// **What it does:** Checks for usage of `std::mem::forget(t)` where `t` is
-/// `Drop`.
-///
-/// **Why is this bad?** `std::mem::forget(t)` prevents `t` from running its
-/// destructor, possibly causing leaks.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// mem::forget(Rc::new(55)))
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `std::mem::forget(t)` where `t` is
+ /// `Drop`.
+ ///
+ /// **Why is this bad?** `std::mem::forget(t)` prevents `t` from running its
+ /// destructor, possibly causing leaks.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::mem;
+ /// # use std::rc::Rc;
+ /// mem::forget(Rc::new(55))
+ /// ```
pub MEM_FORGET,
- Allow,
+ restriction,
"`mem::forget` usage on `Drop` types, likely to cause memory leaks"
}
-pub struct MemForget;
-
-impl LintPass for MemForget {
- fn get_lints(&self) -> LintArray {
- lint_array![MEM_FORGET]
- }
-}
+declare_lint_pass!(MemForget => [MEM_FORGET]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MemForget {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
- if let ExprCall(ref path_expr, ref args) = e.node {
- if let ExprPath(ref qpath) = path_expr.node {
- if let Some(def_id) = opt_def_id(cx.tables.qpath_def(qpath, path_expr.hir_id)) {
- if match_def_path(cx.tcx, def_id, &paths::MEM_FORGET) {
+ if let ExprKind::Call(ref path_expr, ref args) = e.node {
+ if let ExprKind::Path(ref qpath) = path_expr.node {
+ if let Some(def_id) = qpath_res(cx, qpath, path_expr.hir_id).opt_def_id() {
+ if match_def_path(cx, def_id, &paths::MEM_FORGET) {
let forgot_ty = cx.tables.expr_ty(&args[0]);
- if match forgot_ty.ty_adt_def() {
- Some(def) => def.has_dtor(cx.tcx),
- _ => false,
- } {
+ if forgot_ty.ty_adt_def().map_or(false, |def| def.has_dtor(cx.tcx)) {
span_lint(cx, MEM_FORGET, e.span, "usage of mem::forget on Drop type");
}
}