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