61 lines
1.8 KiB
Rust
61 lines
1.8 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_help;
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use clippy_utils::source::snippet;
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use clippy_utils::{is_entrypoint_fn, is_no_std_crate};
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use rustc_hir::{Expr, ExprKind, QPath};
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use rustc_lint::{LateContext, LateLintPass};
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use rustc_session::impl_lint_pass;
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declare_clippy_lint! {
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/// ### What it does
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/// Checks for recursion using the entrypoint.
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///
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/// ### Why is this bad?
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/// Apart from special setups (which we could detect following attributes like #![no_std]),
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/// recursing into main() seems like an unintuitive anti-pattern we should be able to detect.
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///
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/// ### Example
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/// ```no_run
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/// fn main() {
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/// main();
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/// }
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/// ```
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#[clippy::version = "1.38.0"]
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pub MAIN_RECURSION,
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style,
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"recursion using the entrypoint"
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}
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#[derive(Default)]
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pub struct MainRecursion {
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has_no_std_attr: bool,
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}
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impl_lint_pass!(MainRecursion => [MAIN_RECURSION]);
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impl LateLintPass<'_> for MainRecursion {
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fn check_crate(&mut self, cx: &LateContext<'_>) {
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self.has_no_std_attr = is_no_std_crate(cx);
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}
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fn check_expr_post(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
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if self.has_no_std_attr {
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return;
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}
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if let ExprKind::Call(func, _) = &expr.kind
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&& let ExprKind::Path(QPath::Resolved(_, path)) = &func.kind
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&& let Some(def_id) = path.res.opt_def_id()
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&& is_entrypoint_fn(cx, def_id)
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{
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span_lint_and_help(
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cx,
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MAIN_RECURSION,
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func.span,
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&format!("recursing into entrypoint `{}`", snippet(cx, func.span, "main")),
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None,
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"consider using another function for this recursion",
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);
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}
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}
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}
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