rust/clippy_lints/src/exit.rs
2024-07-05 03:12:19 -04:00

60 lines
2.2 KiB
Rust

use clippy_utils::diagnostics::span_lint;
use clippy_utils::is_entrypoint_fn;
use rustc_hir::{Expr, ExprKind, Item, ItemKind, OwnerNode};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::declare_lint_pass;
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
/// Detects calls to the `exit()` function which terminates the program.
///
/// ### Why restrict this?
/// `exit()` immediately terminates the program with no information other than an exit code.
/// This provides no means to troubleshoot a problem, and may be an unexpected side effect.
///
/// Codebases may use this lint to require that all exits are performed either by panicking
/// (which produces a message, a code location, and optionally a backtrace)
/// or by returning from `main()` (which is a single place to look).
///
/// ### Example
/// ```no_run
/// std::process::exit(0)
/// ```
///
/// Use instead:
///
/// ```ignore
/// // To provide a stacktrace and additional information
/// panic!("message");
///
/// // or a main method with a return
/// fn main() -> Result<(), i32> {
/// Ok(())
/// }
/// ```
#[clippy::version = "1.41.0"]
pub EXIT,
restriction,
"detects `std::process::exit` calls"
}
declare_lint_pass!(Exit => [EXIT]);
impl<'tcx> LateLintPass<'tcx> for Exit {
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
if let ExprKind::Call(path_expr, _args) = e.kind
&& let ExprKind::Path(ref path) = path_expr.kind
&& let Some(def_id) = cx.qpath_res(path, path_expr.hir_id).opt_def_id()
&& cx.tcx.is_diagnostic_item(sym::process_exit, def_id)
&& let parent = cx.tcx.hir().get_parent_item(e.hir_id)
&& let OwnerNode::Item(Item{kind: ItemKind::Fn(..), ..}) = cx.tcx.hir_owner_node(parent)
// If the next item up is a function we check if it is an entry point
// and only then emit a linter warning
&& !is_entrypoint_fn(cx, parent.to_def_id())
{
span_lint(cx, EXIT, e.span, "usage of `process::exit`");
}
}
}