1 use rustc_hir
::{Crate, Expr, ExprKind, QPath}
;
2 use rustc_lint
::{LateContext, LateLintPass}
;
3 use rustc_session
::{declare_tool_lint, impl_lint_pass}
;
5 use crate::utils
::{is_entrypoint_fn, is_no_std_crate, snippet, span_lint_and_help}
;
6 use if_chain
::if_chain
;
9 /// **What it does:** Checks for recursion using the entrypoint.
11 /// **Why is this bad?** Apart from special setups (which we could detect following attributes like #![no_std]),
12 /// recursing into main() seems like an unintuitive antipattern we should be able to detect.
14 /// **Known problems:** None.
24 "recursion using the entrypoint"
28 pub struct MainRecursion
{
29 has_no_std_attr
: bool
,
32 impl_lint_pass
!(MainRecursion
=> [MAIN_RECURSION
]);
34 impl LateLintPass
<'_
> for MainRecursion
{
35 fn check_crate(&mut self, _
: &LateContext
<'_
>, krate
: &Crate
<'_
>) {
36 self.has_no_std_attr
= is_no_std_crate(krate
);
39 fn check_expr_post(&mut self, cx
: &LateContext
<'_
>, expr
: &Expr
<'_
>) {
40 if self.has_no_std_attr
{
45 if let ExprKind
::Call(func
, _
) = &expr
.kind
;
46 if let ExprKind
::Path(QPath
::Resolved(_
, path
)) = &func
.kind
;
47 if let Some(def_id
) = path
.res
.opt_def_id();
48 if is_entrypoint_fn(cx
, def_id
);
54 &format
!("recursing into entrypoint `{}`", snippet(cx
, func
.span
, "main")),
56 "consider using another function for this recursion"