rust-clippy/clippy_lints/src/exit.rs
2020-04-24 15:29:31 +02:00

47 lines
1.8 KiB
Rust

use crate::utils::{is_entrypoint_fn, match_def_path, paths, qpath_res, span_lint};
use if_chain::if_chain;
use rustc_hir::{Expr, ExprKind, Item, ItemKind, Node};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// **What it does:** `exit()` terminates the program and doesn't provide a
/// stack trace.
///
/// **Why is this bad?** Ideally a program is terminated by finishing
/// the main function.
///
/// **Known problems:** None.
///
/// **Example:**
/// ```ignore
/// std::process::exit(0)
/// ```
pub EXIT,
restriction,
"`std::process::exit` is called, terminating the program"
}
declare_lint_pass!(Exit => [EXIT]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Exit {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
if_chain! {
if let ExprKind::Call(ref path_expr, ref _args) = e.kind;
if let ExprKind::Path(ref path) = path_expr.kind;
if let Some(def_id) = qpath_res(cx, path, path_expr.hir_id).opt_def_id();
if match_def_path(cx, def_id, &paths::EXIT);
then {
let parent = cx.tcx.hir().get_parent_item(e.hir_id);
if let Some(Node::Item(Item{kind: ItemKind::Fn(..), ..})) = cx.tcx.hir().find(parent) {
// If the next item up is a function we check if it is an entry point
// and only then emit a linter warning
let def_id = cx.tcx.hir().local_def_id(parent);
if !is_entrypoint_fn(cx, def_id.to_def_id()) {
span_lint(cx, EXIT, e.span, "usage of `process::exit`");
}
}
}
}
}
}