rust-clippy/clippy_lints/src/mem_forget.rs

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use clippy_utils::diagnostics::span_lint;
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use clippy_utils::{match_def_path, paths};
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use rustc_hir::{Expr, ExprKind};
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use rustc_lint::{LateContext, LateLintPass};
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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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.
///
/// ### Example
/// ```rust
/// # use std::mem;
/// # use std::rc::Rc;
/// mem::forget(Rc::new(55))
/// ```
Added `clippy::version` attribute to all normal lints So, some context for this, well, more a story. I'm not used to scripting, I've never really scripted anything, even if it's a valuable skill. I just never really needed it. Now, `@flip1995` correctly suggested using a script for this in `rust-clippy#7813`... And I decided to write a script using nushell because why not? This was a mistake... I spend way more time on this than I would like to admit. It has definitely been more than 4 hours. It shouldn't take that long, but me being new to scripting and nushell just wasn't a good mixture... Anyway, here is the script that creates another script which adds the versions. Fun... Just execute this on the `gh-pages` branch and the resulting `replacer.sh` in `clippy_lints` and it should all work. ```nu mv v0.0.212 rust-1.00.0; mv beta rust-1.57.0; mv master rust-1.58.0; let paths = (open ./rust-1.58.0/lints.json | select id id_span | flatten | select id path); let versions = ( ls | where name =~ "rust-" | select name | format {name}/lints.json | each { open $it | select id | insert version $it | str substring "5,11" version} | group-by id | rotate counter-clockwise id version | update version {get version | first 1} | flatten | select id version); $paths | each { |row| let version = ($versions | where id == ($row.id) | format {version}) let idu = ($row.id | str upcase) $"sed -i '0,/($idu),/{s/pub ($idu),/#[clippy::version = "($version)"]\n pub ($idu),/}' ($row.path)" } | str collect ";" | str find-replace --all '1.00.0' 'pre 1.29.0' | save "replacer.sh"; ``` And this still has some problems, but at this point I just want to be done -.-
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#[clippy::version = "pre 1.29.0"]
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pub MEM_FORGET,
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restriction,
"`mem::forget` usage on `Drop` types, likely to cause memory leaks"
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}
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declare_lint_pass!(MemForget => [MEM_FORGET]);
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impl<'tcx> LateLintPass<'tcx> for MemForget {
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
if let ExprKind::Call(path_expr, [ref first_arg, ..]) = e.kind {
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if let ExprKind::Path(ref qpath) = path_expr.kind {
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if let Some(def_id) = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
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if match_def_path(cx, def_id, &paths::MEM_FORGET) {
let forgot_ty = cx.typeck_results().expr_ty(first_arg);
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if forgot_ty.ty_adt_def().map_or(false, |def| def.has_dtor(cx.tcx)) {
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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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}
}
}
}
}